| /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ |
| /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of version 2 of the GNU General Public |
| * License as published by the Free Software Foundation. |
| */ |
| #ifndef _UAPI__LINUX_BPF_H__ |
| #define _UAPI__LINUX_BPF_H__ |
| |
| #include <linux/types.h> |
| #include <linux/bpf_common.h> |
| |
| /* Extended instruction set based on top of classic BPF */ |
| |
| /* instruction classes */ |
| #define BPF_JMP32 0x06 /* jmp mode in word width */ |
| #define BPF_ALU64 0x07 /* alu mode in double word width */ |
| |
| /* ld/ldx fields */ |
| #define BPF_DW 0x18 /* double word (64-bit) */ |
| #define BPF_ATOMIC 0xc0 /* atomic memory ops - op type in immediate */ |
| #define BPF_XADD 0xc0 /* exclusive add - legacy name */ |
| |
| /* alu/jmp fields */ |
| #define BPF_MOV 0xb0 /* mov reg to reg */ |
| #define BPF_ARSH 0xc0 /* sign extending arithmetic shift right */ |
| |
| /* change endianness of a register */ |
| #define BPF_END 0xd0 /* flags for endianness conversion: */ |
| #define BPF_TO_LE 0x00 /* convert to little-endian */ |
| #define BPF_TO_BE 0x08 /* convert to big-endian */ |
| #define BPF_FROM_LE BPF_TO_LE |
| #define BPF_FROM_BE BPF_TO_BE |
| |
| /* jmp encodings */ |
| #define BPF_JNE 0x50 /* jump != */ |
| #define BPF_JLT 0xa0 /* LT is unsigned, '<' */ |
| #define BPF_JLE 0xb0 /* LE is unsigned, '<=' */ |
| #define BPF_JSGT 0x60 /* SGT is signed '>', GT in x86 */ |
| #define BPF_JSGE 0x70 /* SGE is signed '>=', GE in x86 */ |
| #define BPF_JSLT 0xc0 /* SLT is signed, '<' */ |
| #define BPF_JSLE 0xd0 /* SLE is signed, '<=' */ |
| #define BPF_CALL 0x80 /* function call */ |
| #define BPF_EXIT 0x90 /* function return */ |
| |
| /* atomic op type fields (stored in immediate) */ |
| #define BPF_FETCH 0x01 /* not an opcode on its own, used to build others */ |
| #define BPF_XCHG (0xe0 | BPF_FETCH) /* atomic exchange */ |
| #define BPF_CMPXCHG (0xf0 | BPF_FETCH) /* atomic compare-and-write */ |
| |
| /* Register numbers */ |
| enum { |
| BPF_REG_0 = 0, |
| BPF_REG_1, |
| BPF_REG_2, |
| BPF_REG_3, |
| BPF_REG_4, |
| BPF_REG_5, |
| BPF_REG_6, |
| BPF_REG_7, |
| BPF_REG_8, |
| BPF_REG_9, |
| BPF_REG_10, |
| __MAX_BPF_REG, |
| }; |
| |
| /* BPF has 10 general purpose 64-bit registers and stack frame. */ |
| #define MAX_BPF_REG __MAX_BPF_REG |
| |
| struct bpf_insn { |
| __u8 code; /* opcode */ |
| __u8 dst_reg:4; /* dest register */ |
| __u8 src_reg:4; /* source register */ |
| __s16 off; /* signed offset */ |
| __s32 imm; /* signed immediate constant */ |
| }; |
| |
| /* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */ |
| struct bpf_lpm_trie_key { |
| __u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */ |
| __u8 data[0]; /* Arbitrary size */ |
| }; |
| |
| struct bpf_cgroup_storage_key { |
| __u64 cgroup_inode_id; /* cgroup inode id */ |
| __u32 attach_type; /* program attach type */ |
| }; |
| |
| union bpf_iter_link_info { |
| struct { |
| __u32 map_fd; |
| } map; |
| }; |
| |
| /* BPF syscall commands, see bpf(2) man-page for more details. */ |
| /** |
| * DOC: eBPF Syscall Preamble |
| * |
| * The operation to be performed by the **bpf**\ () system call is determined |
| * by the *cmd* argument. Each operation takes an accompanying argument, |
| * provided via *attr*, which is a pointer to a union of type *bpf_attr* (see |
| * below). The size argument is the size of the union pointed to by *attr*. |
| */ |
| /** |
| * DOC: eBPF Syscall Commands |
| * |
| * BPF_MAP_CREATE |
| * Description |
| * Create a map and return a file descriptor that refers to the |
| * map. The close-on-exec file descriptor flag (see **fcntl**\ (2)) |
| * is automatically enabled for the new file descriptor. |
| * |
| * Applying **close**\ (2) to the file descriptor returned by |
| * **BPF_MAP_CREATE** will delete the map (but see NOTES). |
| * |
| * Return |
| * A new file descriptor (a nonnegative integer), or -1 if an |
| * error occurred (in which case, *errno* is set appropriately). |
| * |
| * BPF_MAP_LOOKUP_ELEM |
| * Description |
| * Look up an element with a given *key* in the map referred to |
| * by the file descriptor *map_fd*. |
| * |
| * The *flags* argument may be specified as one of the |
| * following: |
| * |
| * **BPF_F_LOCK** |
| * Look up the value of a spin-locked map without |
| * returning the lock. This must be specified if the |
| * elements contain a spinlock. |
| * |
| * Return |
| * Returns zero on success. On error, -1 is returned and *errno* |
| * is set appropriately. |
| * |
| * BPF_MAP_UPDATE_ELEM |
| * Description |
| * Create or update an element (key/value pair) in a specified map. |
| * |
| * The *flags* argument should be specified as one of the |
| * following: |
| * |
| * **BPF_ANY** |
| * Create a new element or update an existing element. |
| * **BPF_NOEXIST** |
| * Create a new element only if it did not exist. |
| * **BPF_EXIST** |
| * Update an existing element. |
| * **BPF_F_LOCK** |
| * Update a spin_lock-ed map element. |
| * |
| * Return |
| * Returns zero on success. On error, -1 is returned and *errno* |
| * is set appropriately. |
| * |
| * May set *errno* to **EINVAL**, **EPERM**, **ENOMEM**, |
| * **E2BIG**, **EEXIST**, or **ENOENT**. |
| * |
| * **E2BIG** |
| * The number of elements in the map reached the |
| * *max_entries* limit specified at map creation time. |
| * **EEXIST** |
| * If *flags* specifies **BPF_NOEXIST** and the element |
| * with *key* already exists in the map. |
| * **ENOENT** |
| * If *flags* specifies **BPF_EXIST** and the element with |
| * *key* does not exist in the map. |
| * |
| * BPF_MAP_DELETE_ELEM |
| * Description |
| * Look up and delete an element by key in a specified map. |
| * |
| * Return |
| * Returns zero on success. On error, -1 is returned and *errno* |
| * is set appropriately. |
| * |
| * BPF_MAP_GET_NEXT_KEY |
| * Description |
| * Look up an element by key in a specified map and return the key |
| * of the next element. Can be used to iterate over all elements |
| * in the map. |
| * |
| * Return |
| * Returns zero on success. On error, -1 is returned and *errno* |
| * is set appropriately. |
| * |
| * The following cases can be used to iterate over all elements of |
| * the map: |
| * |
| * * If *key* is not found, the operation returns zero and sets |
| * the *next_key* pointer to the key of the first element. |
| * * If *key* is found, the operation returns zero and sets the |
| * *next_key* pointer to the key of the next element. |
| * * If *key* is the last element, returns -1 and *errno* is set |
| * to **ENOENT**. |
| * |
| * May set *errno* to **ENOMEM**, **EFAULT**, **EPERM**, or |
| * **EINVAL** on error. |
| * |
| * BPF_PROG_LOAD |
| * Description |
| * Verify and load an eBPF program, returning a new file |
| * descriptor associated with the program. |
| * |
| * Applying **close**\ (2) to the file descriptor returned by |
| * **BPF_PROG_LOAD** will unload the eBPF program (but see NOTES). |
| * |
| * The close-on-exec file descriptor flag (see **fcntl**\ (2)) is |
| * automatically enabled for the new file descriptor. |
| * |
| * Return |
| * A new file descriptor (a nonnegative integer), or -1 if an |
| * error occurred (in which case, *errno* is set appropriately). |
| * |
| * BPF_OBJ_PIN |
| * Description |
| * Pin an eBPF program or map referred by the specified *bpf_fd* |
| * to the provided *pathname* on the filesystem. |
| * |
| * The *pathname* argument must not contain a dot ("."). |
| * |
| * On success, *pathname* retains a reference to the eBPF object, |
| * preventing deallocation of the object when the original |
| * *bpf_fd* is closed. This allow the eBPF object to live beyond |
| * **close**\ (\ *bpf_fd*\ ), and hence the lifetime of the parent |
| * process. |
| * |
| * Applying **unlink**\ (2) or similar calls to the *pathname* |
| * unpins the object from the filesystem, removing the reference. |
| * If no other file descriptors or filesystem nodes refer to the |
| * same object, it will be deallocated (see NOTES). |
| * |
| * The filesystem type for the parent directory of *pathname* must |
| * be **BPF_FS_MAGIC**. |
| * |
| * Return |
| * Returns zero on success. On error, -1 is returned and *errno* |
| * is set appropriately. |
| * |
| * BPF_OBJ_GET |
| * Description |
| * Open a file descriptor for the eBPF object pinned to the |
| * specified *pathname*. |
| * |
| * Return |
| * A new file descriptor (a nonnegative integer), or -1 if an |
| * error occurred (in which case, *errno* is set appropriately). |
| * |
| * BPF_PROG_ATTACH |
| * Description |
| * Attach an eBPF program to a *target_fd* at the specified |
| * *attach_type* hook. |
| * |
| * The *attach_type* specifies the eBPF attachment point to |
| * attach the program to, and must be one of *bpf_attach_type* |
| * (see below). |
| * |
| * The *attach_bpf_fd* must be a valid file descriptor for a |
| * loaded eBPF program of a cgroup, flow dissector, LIRC, sockmap |
| * or sock_ops type corresponding to the specified *attach_type*. |
| * |
| * The *target_fd* must be a valid file descriptor for a kernel |
| * object which depends on the attach type of *attach_bpf_fd*: |
| * |
| * **BPF_PROG_TYPE_CGROUP_DEVICE**, |
| * **BPF_PROG_TYPE_CGROUP_SKB**, |
| * **BPF_PROG_TYPE_CGROUP_SOCK**, |
| * **BPF_PROG_TYPE_CGROUP_SOCK_ADDR**, |
| * **BPF_PROG_TYPE_CGROUP_SOCKOPT**, |
| * **BPF_PROG_TYPE_CGROUP_SYSCTL**, |
| * **BPF_PROG_TYPE_SOCK_OPS** |
| * |
| * Control Group v2 hierarchy with the eBPF controller |
| * enabled. Requires the kernel to be compiled with |
| * **CONFIG_CGROUP_BPF**. |
| * |
| * **BPF_PROG_TYPE_FLOW_DISSECTOR** |
| * |
| * Network namespace (eg /proc/self/ns/net). |
| * |
| * **BPF_PROG_TYPE_LIRC_MODE2** |
| * |
| * LIRC device path (eg /dev/lircN). Requires the kernel |
| * to be compiled with **CONFIG_BPF_LIRC_MODE2**. |
| * |
| * **BPF_PROG_TYPE_SK_SKB**, |
| * **BPF_PROG_TYPE_SK_MSG** |
| * |
| * eBPF map of socket type (eg **BPF_MAP_TYPE_SOCKHASH**). |
| * |
| * Return |
| * Returns zero on success. On error, -1 is returned and *errno* |
| * is set appropriately. |
| * |
| * BPF_PROG_DETACH |
| * Description |
| * Detach the eBPF program associated with the *target_fd* at the |
| * hook specified by *attach_type*. The program must have been |
| * previously attached using **BPF_PROG_ATTACH**. |
| * |
| * Return |
| * Returns zero on success. On error, -1 is returned and *errno* |
| * is set appropriately. |
| * |
| * BPF_PROG_TEST_RUN |
| * Description |
| * Run the eBPF program associated with the *prog_fd* a *repeat* |
| * number of times against a provided program context *ctx_in* and |
| * data *data_in*, and return the modified program context |
| * *ctx_out*, *data_out* (for example, packet data), result of the |
| * execution *retval*, and *duration* of the test run. |
| * |
| * The sizes of the buffers provided as input and output |
| * parameters *ctx_in*, *ctx_out*, *data_in*, and *data_out* must |
| * be provided in the corresponding variables *ctx_size_in*, |
| * *ctx_size_out*, *data_size_in*, and/or *data_size_out*. If any |
| * of these parameters are not provided (ie set to NULL), the |
| * corresponding size field must be zero. |
| * |
| * Some program types have particular requirements: |
| * |
| * **BPF_PROG_TYPE_SK_LOOKUP** |
| * *data_in* and *data_out* must be NULL. |
| * |
| * **BPF_PROG_TYPE_XDP** |
| * *ctx_in* and *ctx_out* must be NULL. |
| * |
| * **BPF_PROG_TYPE_RAW_TRACEPOINT**, |
| * **BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE** |
| * |
| * *ctx_out*, *data_in* and *data_out* must be NULL. |
| * *repeat* must be zero. |
| * |
| * Return |
| * Returns zero on success. On error, -1 is returned and *errno* |
| * is set appropriately. |
| * |
| * **ENOSPC** |
| * Either *data_size_out* or *ctx_size_out* is too small. |
| * **ENOTSUPP** |
| * This command is not supported by the program type of |
| * the program referred to by *prog_fd*. |
| * |
| * BPF_PROG_GET_NEXT_ID |
| * Description |
| * Fetch the next eBPF program currently loaded into the kernel. |
| * |
| * Looks for the eBPF program with an id greater than *start_id* |
| * and updates *next_id* on success. If no other eBPF programs |
| * remain with ids higher than *start_id*, returns -1 and sets |
| * *errno* to **ENOENT**. |
| * |
| * Return |
| * Returns zero on success. On error, or when no id remains, -1 |
| * is returned and *errno* is set appropriately. |
| * |
| * BPF_MAP_GET_NEXT_ID |
| * Description |
| * Fetch the next eBPF map currently loaded into the kernel. |
| * |
| * Looks for the eBPF map with an id greater than *start_id* |
| * and updates *next_id* on success. If no other eBPF maps |
| * remain with ids higher than *start_id*, returns -1 and sets |
| * *errno* to **ENOENT**. |
| * |
| * Return |
| * Returns zero on success. On error, or when no id remains, -1 |
| * is returned and *errno* is set appropriately. |
| * |
| * BPF_PROG_GET_FD_BY_ID |
| * Description |
| * Open a file descriptor for the eBPF program corresponding to |
| * *prog_id*. |
| * |
| * Return |
| * A new file descriptor (a nonnegative integer), or -1 if an |
| * error occurred (in which case, *errno* is set appropriately). |
| * |
| * BPF_MAP_GET_FD_BY_ID |
| * Description |
| * Open a file descriptor for the eBPF map corresponding to |
| * *map_id*. |
| * |
| * Return |
| * A new file descriptor (a nonnegative integer), or -1 if an |
| * error occurred (in which case, *errno* is set appropriately). |
| * |
| * BPF_OBJ_GET_INFO_BY_FD |
| * Description |
| * Obtain information about the eBPF object corresponding to |
| * *bpf_fd*. |
| * |
| * Populates up to *info_len* bytes of *info*, which will be in |
| * one of the following formats depending on the eBPF object type |
| * of *bpf_fd*: |
| * |
| * * **struct bpf_prog_info** |
| * * **struct bpf_map_info** |
| * * **struct bpf_btf_info** |
| * * **struct bpf_link_info** |
| * |
| * Return |
| * Returns zero on success. On error, -1 is returned and *errno* |
| * is set appropriately. |
| * |
| * BPF_PROG_QUERY |
| * Description |
| * Obtain information about eBPF programs associated with the |
| * specified *attach_type* hook. |
| * |
| * The *target_fd* must be a valid file descriptor for a kernel |
| * object which depends on the attach type of *attach_bpf_fd*: |
| * |
| * **BPF_PROG_TYPE_CGROUP_DEVICE**, |
| * **BPF_PROG_TYPE_CGROUP_SKB**, |
| * **BPF_PROG_TYPE_CGROUP_SOCK**, |
| * **BPF_PROG_TYPE_CGROUP_SOCK_ADDR**, |
| * **BPF_PROG_TYPE_CGROUP_SOCKOPT**, |
| * **BPF_PROG_TYPE_CGROUP_SYSCTL**, |
| * **BPF_PROG_TYPE_SOCK_OPS** |
| * |
| * Control Group v2 hierarchy with the eBPF controller |
| * enabled. Requires the kernel to be compiled with |
| * **CONFIG_CGROUP_BPF**. |
| * |
| * **BPF_PROG_TYPE_FLOW_DISSECTOR** |
| * |
| * Network namespace (eg /proc/self/ns/net). |
| * |
| * **BPF_PROG_TYPE_LIRC_MODE2** |
| * |
| * LIRC device path (eg /dev/lircN). Requires the kernel |
| * to be compiled with **CONFIG_BPF_LIRC_MODE2**. |
| * |
| * **BPF_PROG_QUERY** always fetches the number of programs |
| * attached and the *attach_flags* which were used to attach those |
| * programs. Additionally, if *prog_ids* is nonzero and the number |
| * of attached programs is less than *prog_cnt*, populates |
| * *prog_ids* with the eBPF program ids of the programs attached |
| * at *target_fd*. |
| * |
| * The following flags may alter the result: |
| * |
| * **BPF_F_QUERY_EFFECTIVE** |
| * Only return information regarding programs which are |
| * currently effective at the specified *target_fd*. |
| * |
| * Return |
| * Returns zero on success. On error, -1 is returned and *errno* |
| * is set appropriately. |
| * |
| * BPF_RAW_TRACEPOINT_OPEN |
| * Description |
| * Attach an eBPF program to a tracepoint *name* to access kernel |
| * internal arguments of the tracepoint in their raw form. |
| * |
| * The *prog_fd* must be a valid file descriptor associated with |
| * a loaded eBPF program of type **BPF_PROG_TYPE_RAW_TRACEPOINT**. |
| * |
| * No ABI guarantees are made about the content of tracepoint |
| * arguments exposed to the corresponding eBPF program. |
| * |
| * Applying **close**\ (2) to the file descriptor returned by |
| * **BPF_RAW_TRACEPOINT_OPEN** will delete the map (but see NOTES). |
| * |
| * Return |
| * A new file descriptor (a nonnegative integer), or -1 if an |
| * error occurred (in which case, *errno* is set appropriately). |
| * |
| * BPF_BTF_LOAD |
| * Description |
| * Verify and load BPF Type Format (BTF) metadata into the kernel, |
| * returning a new file descriptor associated with the metadata. |
| * BTF is described in more detail at |
| * https://www.kernel.org/doc/html/latest/bpf/btf.html. |
| * |
| * The *btf* parameter must point to valid memory providing |
| * *btf_size* bytes of BTF binary metadata. |
| * |
| * The returned file descriptor can be passed to other **bpf**\ () |
| * subcommands such as **BPF_PROG_LOAD** or **BPF_MAP_CREATE** to |
| * associate the BTF with those objects. |
| * |
| * Similar to **BPF_PROG_LOAD**, **BPF_BTF_LOAD** has optional |
| * parameters to specify a *btf_log_buf*, *btf_log_size* and |
| * *btf_log_level* which allow the kernel to return freeform log |
| * output regarding the BTF verification process. |
| * |
| * Return |
| * A new file descriptor (a nonnegative integer), or -1 if an |
| * error occurred (in which case, *errno* is set appropriately). |
| * |
| * BPF_BTF_GET_FD_BY_ID |
| * Description |
| * Open a file descriptor for the BPF Type Format (BTF) |
| * corresponding to *btf_id*. |
| * |
| * Return |
| * A new file descriptor (a nonnegative integer), or -1 if an |
| * error occurred (in which case, *errno* is set appropriately). |
| * |
| * BPF_TASK_FD_QUERY |
| * Description |
| * Obtain information about eBPF programs associated with the |
| * target process identified by *pid* and *fd*. |
| * |
| * If the *pid* and *fd* are associated with a tracepoint, kprobe |
| * or uprobe perf event, then the *prog_id* and *fd_type* will |
| * be populated with the eBPF program id and file descriptor type |
| * of type **bpf_task_fd_type**. If associated with a kprobe or |
| * uprobe, the *probe_offset* and *probe_addr* will also be |
| * populated. Optionally, if *buf* is provided, then up to |
| * *buf_len* bytes of *buf* will be populated with the name of |
| * the tracepoint, kprobe or uprobe. |
| * |
| * The resulting *prog_id* may be introspected in deeper detail |
| * using **BPF_PROG_GET_FD_BY_ID** and **BPF_OBJ_GET_INFO_BY_FD**. |
| * |
| * Return |
| * Returns zero on success. On error, -1 is returned and *errno* |
| * is set appropriately. |
| * |
| * BPF_MAP_LOOKUP_AND_DELETE_ELEM |
| * Description |
| * Look up an element with the given *key* in the map referred to |
| * by the file descriptor *fd*, and if found, delete the element. |
| * |
| * For **BPF_MAP_TYPE_QUEUE** and **BPF_MAP_TYPE_STACK** map |
| * types, the *flags* argument needs to be set to 0, but for other |
| * map types, it may be specified as: |
| * |
| * **BPF_F_LOCK** |
| * Look up and delete the value of a spin-locked map |
| * without returning the lock. This must be specified if |
| * the elements contain a spinlock. |
| * |
| * The **BPF_MAP_TYPE_QUEUE** and **BPF_MAP_TYPE_STACK** map types |
| * implement this command as a "pop" operation, deleting the top |
| * element rather than one corresponding to *key*. |
| * The *key* and *key_len* parameters should be zeroed when |
| * issuing this operation for these map types. |
| * |
| * This command is only valid for the following map types: |
| * * **BPF_MAP_TYPE_QUEUE** |
| * * **BPF_MAP_TYPE_STACK** |
| * * **BPF_MAP_TYPE_HASH** |
| * * **BPF_MAP_TYPE_PERCPU_HASH** |
| * * **BPF_MAP_TYPE_LRU_HASH** |
| * * **BPF_MAP_TYPE_LRU_PERCPU_HASH** |
| * |
| * Return |
| * Returns zero on success. On error, -1 is returned and *errno* |
| * is set appropriately. |
| * |
| * BPF_MAP_FREEZE |
| * Description |
| * Freeze the permissions of the specified map. |
| * |
| * Write permissions may be frozen by passing zero *flags*. |
| * Upon success, no future syscall invocations may alter the |
| * map state of *map_fd*. Write operations from eBPF programs |
| * are still possible for a frozen map. |
| * |
| * Not supported for maps of type **BPF_MAP_TYPE_STRUCT_OPS**. |
| * |
| * Return |
| * Returns zero on success. On error, -1 is returned and *errno* |
| * is set appropriately. |
| * |
| * BPF_BTF_GET_NEXT_ID |
| * Description |
| * Fetch the next BPF Type Format (BTF) object currently loaded |
| * into the kernel. |
| * |
| * Looks for the BTF object with an id greater than *start_id* |
| * and updates *next_id* on success. If no other BTF objects |
| * remain with ids higher than *start_id*, returns -1 and sets |
| * *errno* to **ENOENT**. |
| * |
| * Return |
| * Returns zero on success. On error, or when no id remains, -1 |
| * is returned and *errno* is set appropriately. |
| * |
| * BPF_MAP_LOOKUP_BATCH |
| * Description |
| * Iterate and fetch multiple elements in a map. |
| * |
| * Two opaque values are used to manage batch operations, |
| * *in_batch* and *out_batch*. Initially, *in_batch* must be set |
| * to NULL to begin the batched operation. After each subsequent |
| * **BPF_MAP_LOOKUP_BATCH**, the caller should pass the resultant |
| * *out_batch* as the *in_batch* for the next operation to |
| * continue iteration from the current point. |
| * |
| * The *keys* and *values* are output parameters which must point |
| * to memory large enough to hold *count* items based on the key |
| * and value size of the map *map_fd*. The *keys* buffer must be |
| * of *key_size* * *count*. The *values* buffer must be of |
| * *value_size* * *count*. |
| * |
| * The *elem_flags* argument may be specified as one of the |
| * following: |
| * |
| * **BPF_F_LOCK** |
| * Look up the value of a spin-locked map without |
| * returning the lock. This must be specified if the |
| * elements contain a spinlock. |
| * |
| * On success, *count* elements from the map are copied into the |
| * user buffer, with the keys copied into *keys* and the values |
| * copied into the corresponding indices in *values*. |
| * |
| * If an error is returned and *errno* is not **EFAULT**, *count* |
| * is set to the number of successfully processed elements. |
| * |
| * Return |
| * Returns zero on success. On error, -1 is returned and *errno* |
| * is set appropriately. |
| * |
| * May set *errno* to **ENOSPC** to indicate that *keys* or |
| * *values* is too small to dump an entire bucket during |
| * iteration of a hash-based map type. |
| * |
| * BPF_MAP_LOOKUP_AND_DELETE_BATCH |
| * Description |
| * Iterate and delete all elements in a map. |
| * |
| * This operation has the same behavior as |
| * **BPF_MAP_LOOKUP_BATCH** with two exceptions: |
| * |
| * * Every element that is successfully returned is also deleted |
| * from the map. This is at least *count* elements. Note that |
| * *count* is both an input and an output parameter. |
| * * Upon returning with *errno* set to **EFAULT**, up to |
| * *count* elements may be deleted without returning the keys |
| * and values of the deleted elements. |
| * |
| * Return |
| * Returns zero on success. On error, -1 is returned and *errno* |
| * is set appropriately. |
| * |
| * BPF_MAP_UPDATE_BATCH |
| * Description |
| * Update multiple elements in a map by *key*. |
| * |
| * The *keys* and *values* are input parameters which must point |
| * to memory large enough to hold *count* items based on the key |
| * and value size of the map *map_fd*. The *keys* buffer must be |
| * of *key_size* * *count*. The *values* buffer must be of |
| * *value_size* * *count*. |
| * |
| * Each element specified in *keys* is sequentially updated to the |
| * value in the corresponding index in *values*. The *in_batch* |
| * and *out_batch* parameters are ignored and should be zeroed. |
| * |
| * The *elem_flags* argument should be specified as one of the |
| * following: |
| * |
| * **BPF_ANY** |
| * Create new elements or update a existing elements. |
| * **BPF_NOEXIST** |
| * Create new elements only if they do not exist. |
| * **BPF_EXIST** |
| * Update existing elements. |
| * **BPF_F_LOCK** |
| * Update spin_lock-ed map elements. This must be |
| * specified if the map value contains a spinlock. |
| * |
| * On success, *count* elements from the map are updated. |
| * |
| * If an error is returned and *errno* is not **EFAULT**, *count* |
| * is set to the number of successfully processed elements. |
| * |
| * Return |
| * Returns zero on success. On error, -1 is returned and *errno* |
| * is set appropriately. |
| * |
| * May set *errno* to **EINVAL**, **EPERM**, **ENOMEM**, or |
| * **E2BIG**. **E2BIG** indicates that the number of elements in |
| * the map reached the *max_entries* limit specified at map |
| * creation time. |
| * |
| * May set *errno* to one of the following error codes under |
| * specific circumstances: |
| * |
| * **EEXIST** |
| * If *flags* specifies **BPF_NOEXIST** and the element |
| * with *key* already exists in the map. |
| * **ENOENT** |
| * If *flags* specifies **BPF_EXIST** and the element with |
| * *key* does not exist in the map. |
| * |
| * BPF_MAP_DELETE_BATCH |
| * Description |
| * Delete multiple elements in a map by *key*. |
| * |
| * The *keys* parameter is an input parameter which must point |
| * to memory large enough to hold *count* items based on the key |
| * size of the map *map_fd*, that is, *key_size* * *count*. |
| * |
| * Each element specified in *keys* is sequentially deleted. The |
| * *in_batch*, *out_batch*, and *values* parameters are ignored |
| * and should be zeroed. |
| * |
| * The *elem_flags* argument may be specified as one of the |
| * following: |
| * |
| * **BPF_F_LOCK** |
| * Look up the value of a spin-locked map without |
| * returning the lock. This must be specified if the |
| * elements contain a spinlock. |
| * |
| * On success, *count* elements from the map are updated. |
| * |
| * If an error is returned and *errno* is not **EFAULT**, *count* |
| * is set to the number of successfully processed elements. If |
| * *errno* is **EFAULT**, up to *count* elements may be been |
| * deleted. |
| * |
| * Return |
| * Returns zero on success. On error, -1 is returned and *errno* |
| * is set appropriately. |
| * |
| * BPF_LINK_CREATE |
| * Description |
| * Attach an eBPF program to a *target_fd* at the specified |
| * *attach_type* hook and return a file descriptor handle for |
| * managing the link. |
| * |
| * Return |
| * A new file descriptor (a nonnegative integer), or -1 if an |
| * error occurred (in which case, *errno* is set appropriately). |
| * |
| * BPF_LINK_UPDATE |
| * Description |
| * Update the eBPF program in the specified *link_fd* to |
| * *new_prog_fd*. |
| * |
| * Return |
| * Returns zero on success. On error, -1 is returned and *errno* |
| * is set appropriately. |
| * |
| * BPF_LINK_GET_FD_BY_ID |
| * Description |
| * Open a file descriptor for the eBPF Link corresponding to |
| * *link_id*. |
| * |
| * Return |
| * A new file descriptor (a nonnegative integer), or -1 if an |
| * error occurred (in which case, *errno* is set appropriately). |
| * |
| * BPF_LINK_GET_NEXT_ID |
| * Description |
| * Fetch the next eBPF link currently loaded into the kernel. |
| * |
| * Looks for the eBPF link with an id greater than *start_id* |
| * and updates *next_id* on success. If no other eBPF links |
| * remain with ids higher than *start_id*, returns -1 and sets |
| * *errno* to **ENOENT**. |
| * |
| * Return |
| * Returns zero on success. On error, or when no id remains, -1 |
| * is returned and *errno* is set appropriately. |
| * |
| * BPF_ENABLE_STATS |
| * Description |
| * Enable eBPF runtime statistics gathering. |
| * |
| * Runtime statistics gathering for the eBPF runtime is disabled |
| * by default to minimize the corresponding performance overhead. |
| * This command enables statistics globally. |
| * |
| * Multiple programs may independently enable statistics. |
| * After gathering the desired statistics, eBPF runtime statistics |
| * may be disabled again by calling **close**\ (2) for the file |
| * descriptor returned by this function. Statistics will only be |
| * disabled system-wide when all outstanding file descriptors |
| * returned by prior calls for this subcommand are closed. |
| * |
| * Return |
| * A new file descriptor (a nonnegative integer), or -1 if an |
| * error occurred (in which case, *errno* is set appropriately). |
| * |
| * BPF_ITER_CREATE |
| * Description |
| * Create an iterator on top of the specified *link_fd* (as |
| * previously created using **BPF_LINK_CREATE**) and return a |
| * file descriptor that can be used to trigger the iteration. |
| * |
| * If the resulting file descriptor is pinned to the filesystem |
| * using **BPF_OBJ_PIN**, then subsequent **read**\ (2) syscalls |
| * for that path will trigger the iterator to read kernel state |
| * using the eBPF program attached to *link_fd*. |
| * |
| * Return |
| * A new file descriptor (a nonnegative integer), or -1 if an |
| * error occurred (in which case, *errno* is set appropriately). |
| * |
| * BPF_LINK_DETACH |
| * Description |
| * Forcefully detach the specified *link_fd* from its |
| * corresponding attachment point. |
| * |
| * Return |
| * Returns zero on success. On error, -1 is returned and *errno* |
| * is set appropriately. |
| * |
| * BPF_PROG_BIND_MAP |
| * Description |
| * Bind a map to the lifetime of an eBPF program. |
| * |
| * The map identified by *map_fd* is bound to the program |
| * identified by *prog_fd* and only released when *prog_fd* is |
| * released. This may be used in cases where metadata should be |
| * associated with a program which otherwise does not contain any |
| * references to the map (for example, embedded in the eBPF |
| * program instructions). |
| * |
| * Return |
| * Returns zero on success. On error, -1 is returned and *errno* |
| * is set appropriately. |
| * |
| * NOTES |
| * eBPF objects (maps and programs) can be shared between processes. |
| * |
| * * After **fork**\ (2), the child inherits file descriptors |
| * referring to the same eBPF objects. |
| * * File descriptors referring to eBPF objects can be transferred over |
| * **unix**\ (7) domain sockets. |
| * * File descriptors referring to eBPF objects can be duplicated in the |
| * usual way, using **dup**\ (2) and similar calls. |
| * * File descriptors referring to eBPF objects can be pinned to the |
| * filesystem using the **BPF_OBJ_PIN** command of **bpf**\ (2). |
| * |
| * An eBPF object is deallocated only after all file descriptors referring |
| * to the object have been closed and no references remain pinned to the |
| * filesystem or attached (for example, bound to a program or device). |
| */ |
| enum bpf_cmd { |
| BPF_MAP_CREATE, |
| BPF_MAP_LOOKUP_ELEM, |
| BPF_MAP_UPDATE_ELEM, |
| BPF_MAP_DELETE_ELEM, |
| BPF_MAP_GET_NEXT_KEY, |
| BPF_PROG_LOAD, |
| BPF_OBJ_PIN, |
| BPF_OBJ_GET, |
| BPF_PROG_ATTACH, |
| BPF_PROG_DETACH, |
| BPF_PROG_TEST_RUN, |
| BPF_PROG_RUN = BPF_PROG_TEST_RUN, |
| BPF_PROG_GET_NEXT_ID, |
| BPF_MAP_GET_NEXT_ID, |
| BPF_PROG_GET_FD_BY_ID, |
| BPF_MAP_GET_FD_BY_ID, |
| BPF_OBJ_GET_INFO_BY_FD, |
| BPF_PROG_QUERY, |
| BPF_RAW_TRACEPOINT_OPEN, |
| BPF_BTF_LOAD, |
| BPF_BTF_GET_FD_BY_ID, |
| BPF_TASK_FD_QUERY, |
| BPF_MAP_LOOKUP_AND_DELETE_ELEM, |
| BPF_MAP_FREEZE, |
| BPF_BTF_GET_NEXT_ID, |
| BPF_MAP_LOOKUP_BATCH, |
| BPF_MAP_LOOKUP_AND_DELETE_BATCH, |
| BPF_MAP_UPDATE_BATCH, |
| BPF_MAP_DELETE_BATCH, |
| BPF_LINK_CREATE, |
| BPF_LINK_UPDATE, |
| BPF_LINK_GET_FD_BY_ID, |
| BPF_LINK_GET_NEXT_ID, |
| BPF_ENABLE_STATS, |
| BPF_ITER_CREATE, |
| BPF_LINK_DETACH, |
| BPF_PROG_BIND_MAP, |
| }; |
| |
| enum bpf_map_type { |
| BPF_MAP_TYPE_UNSPEC, |
| BPF_MAP_TYPE_HASH, |
| BPF_MAP_TYPE_ARRAY, |
| BPF_MAP_TYPE_PROG_ARRAY, |
| BPF_MAP_TYPE_PERF_EVENT_ARRAY, |
| BPF_MAP_TYPE_PERCPU_HASH, |
| BPF_MAP_TYPE_PERCPU_ARRAY, |
| BPF_MAP_TYPE_STACK_TRACE, |
| BPF_MAP_TYPE_CGROUP_ARRAY, |
| BPF_MAP_TYPE_LRU_HASH, |
| BPF_MAP_TYPE_LRU_PERCPU_HASH, |
| BPF_MAP_TYPE_LPM_TRIE, |
| BPF_MAP_TYPE_ARRAY_OF_MAPS, |
| BPF_MAP_TYPE_HASH_OF_MAPS, |
| BPF_MAP_TYPE_DEVMAP, |
| BPF_MAP_TYPE_SOCKMAP, |
| BPF_MAP_TYPE_CPUMAP, |
| BPF_MAP_TYPE_XSKMAP, |
| BPF_MAP_TYPE_SOCKHASH, |
| BPF_MAP_TYPE_CGROUP_STORAGE, |
| BPF_MAP_TYPE_REUSEPORT_SOCKARRAY, |
| BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE, |
| BPF_MAP_TYPE_QUEUE, |
| BPF_MAP_TYPE_STACK, |
| BPF_MAP_TYPE_SK_STORAGE, |
| BPF_MAP_TYPE_DEVMAP_HASH, |
| BPF_MAP_TYPE_STRUCT_OPS, |
| BPF_MAP_TYPE_RINGBUF, |
| BPF_MAP_TYPE_INODE_STORAGE, |
| BPF_MAP_TYPE_TASK_STORAGE, |
| }; |
| |
| /* Note that tracing related programs such as |
| * BPF_PROG_TYPE_{KPROBE,TRACEPOINT,PERF_EVENT,RAW_TRACEPOINT} |
| * are not subject to a stable API since kernel internal data |
| * structures can change from release to release and may |
| * therefore break existing tracing BPF programs. Tracing BPF |
| * programs correspond to /a/ specific kernel which is to be |
| * analyzed, and not /a/ specific kernel /and/ all future ones. |
| */ |
| enum bpf_prog_type { |
| BPF_PROG_TYPE_UNSPEC, |
| BPF_PROG_TYPE_SOCKET_FILTER, |
| BPF_PROG_TYPE_KPROBE, |
| BPF_PROG_TYPE_SCHED_CLS, |
| BPF_PROG_TYPE_SCHED_ACT, |
| BPF_PROG_TYPE_TRACEPOINT, |
| BPF_PROG_TYPE_XDP, |
| BPF_PROG_TYPE_PERF_EVENT, |
| BPF_PROG_TYPE_CGROUP_SKB, |
| BPF_PROG_TYPE_CGROUP_SOCK, |
| BPF_PROG_TYPE_LWT_IN, |
| BPF_PROG_TYPE_LWT_OUT, |
| BPF_PROG_TYPE_LWT_XMIT, |
| BPF_PROG_TYPE_SOCK_OPS, |
| BPF_PROG_TYPE_SK_SKB, |
| BPF_PROG_TYPE_CGROUP_DEVICE, |
| BPF_PROG_TYPE_SK_MSG, |
| BPF_PROG_TYPE_RAW_TRACEPOINT, |
| BPF_PROG_TYPE_CGROUP_SOCK_ADDR, |
| BPF_PROG_TYPE_LWT_SEG6LOCAL, |
| BPF_PROG_TYPE_LIRC_MODE2, |
| BPF_PROG_TYPE_SK_REUSEPORT, |
| BPF_PROG_TYPE_FLOW_DISSECTOR, |
| BPF_PROG_TYPE_CGROUP_SYSCTL, |
| BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE, |
| BPF_PROG_TYPE_CGROUP_SOCKOPT, |
| BPF_PROG_TYPE_TRACING, |
| BPF_PROG_TYPE_STRUCT_OPS, |
| BPF_PROG_TYPE_EXT, |
| BPF_PROG_TYPE_LSM, |
| BPF_PROG_TYPE_SK_LOOKUP, |
| BPF_PROG_TYPE_SYSCALL, /* a program that can execute syscalls */ |
| }; |
| |
| enum bpf_attach_type { |
| BPF_CGROUP_INET_INGRESS, |
| BPF_CGROUP_INET_EGRESS, |
| BPF_CGROUP_INET_SOCK_CREATE, |
| BPF_CGROUP_SOCK_OPS, |
| BPF_SK_SKB_STREAM_PARSER, |
| BPF_SK_SKB_STREAM_VERDICT, |
| BPF_CGROUP_DEVICE, |
| BPF_SK_MSG_VERDICT, |
| BPF_CGROUP_INET4_BIND, |
| BPF_CGROUP_INET6_BIND, |
| BPF_CGROUP_INET4_CONNECT, |
| BPF_CGROUP_INET6_CONNECT, |
| BPF_CGROUP_INET4_POST_BIND, |
| BPF_CGROUP_INET6_POST_BIND, |
| BPF_CGROUP_UDP4_SENDMSG, |
| BPF_CGROUP_UDP6_SENDMSG, |
| BPF_LIRC_MODE2, |
| BPF_FLOW_DISSECTOR, |
| BPF_CGROUP_SYSCTL, |
| BPF_CGROUP_UDP4_RECVMSG, |
| BPF_CGROUP_UDP6_RECVMSG, |
| BPF_CGROUP_GETSOCKOPT, |
| BPF_CGROUP_SETSOCKOPT, |
| BPF_TRACE_RAW_TP, |
| BPF_TRACE_FENTRY, |
| BPF_TRACE_FEXIT, |
| BPF_MODIFY_RETURN, |
| BPF_LSM_MAC, |
| BPF_TRACE_ITER, |
| BPF_CGROUP_INET4_GETPEERNAME, |
| BPF_CGROUP_INET6_GETPEERNAME, |
| BPF_CGROUP_INET4_GETSOCKNAME, |
| BPF_CGROUP_INET6_GETSOCKNAME, |
| BPF_XDP_DEVMAP, |
| BPF_CGROUP_INET_SOCK_RELEASE, |
| BPF_XDP_CPUMAP, |
| BPF_SK_LOOKUP, |
| BPF_XDP, |
| BPF_SK_SKB_VERDICT, |
| BPF_SK_REUSEPORT_SELECT, |
| BPF_SK_REUSEPORT_SELECT_OR_MIGRATE, |
| __MAX_BPF_ATTACH_TYPE |
| }; |
| |
| #define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE |
| |
| enum bpf_link_type { |
| BPF_LINK_TYPE_UNSPEC = 0, |
| BPF_LINK_TYPE_RAW_TRACEPOINT = 1, |
| BPF_LINK_TYPE_TRACING = 2, |
| BPF_LINK_TYPE_CGROUP = 3, |
| BPF_LINK_TYPE_ITER = 4, |
| BPF_LINK_TYPE_NETNS = 5, |
| BPF_LINK_TYPE_XDP = 6, |
| |
| MAX_BPF_LINK_TYPE, |
| }; |
| |
| /* cgroup-bpf attach flags used in BPF_PROG_ATTACH command |
| * |
| * NONE(default): No further bpf programs allowed in the subtree. |
| * |
| * BPF_F_ALLOW_OVERRIDE: If a sub-cgroup installs some bpf program, |
| * the program in this cgroup yields to sub-cgroup program. |
| * |
| * BPF_F_ALLOW_MULTI: If a sub-cgroup installs some bpf program, |
| * that cgroup program gets run in addition to the program in this cgroup. |
| * |
| * Only one program is allowed to be attached to a cgroup with |
| * NONE or BPF_F_ALLOW_OVERRIDE flag. |
| * Attaching another program on top of NONE or BPF_F_ALLOW_OVERRIDE will |
| * release old program and attach the new one. Attach flags has to match. |
| * |
| * Multiple programs are allowed to be attached to a cgroup with |
| * BPF_F_ALLOW_MULTI flag. They are executed in FIFO order |
| * (those that were attached first, run first) |
| * The programs of sub-cgroup are executed first, then programs of |
| * this cgroup and then programs of parent cgroup. |
| * When children program makes decision (like picking TCP CA or sock bind) |
| * parent program has a chance to override it. |
| * |
| * With BPF_F_ALLOW_MULTI a new program is added to the end of the list of |
| * programs for a cgroup. Though it's possible to replace an old program at |
| * any position by also specifying BPF_F_REPLACE flag and position itself in |
| * replace_bpf_fd attribute. Old program at this position will be released. |
| * |
| * A cgroup with MULTI or OVERRIDE flag allows any attach flags in sub-cgroups. |
| * A cgroup with NONE doesn't allow any programs in sub-cgroups. |
| * Ex1: |
| * cgrp1 (MULTI progs A, B) -> |
| * cgrp2 (OVERRIDE prog C) -> |
| * cgrp3 (MULTI prog D) -> |
| * cgrp4 (OVERRIDE prog E) -> |
| * cgrp5 (NONE prog F) |
| * the event in cgrp5 triggers execution of F,D,A,B in that order. |
| * if prog F is detached, the execution is E,D,A,B |
| * if prog F and D are detached, the execution is E,A,B |
| * if prog F, E and D are detached, the execution is C,A,B |
| * |
| * All eligible programs are executed regardless of return code from |
| * earlier programs. |
| */ |
| #define BPF_F_ALLOW_OVERRIDE (1U << 0) |
| #define BPF_F_ALLOW_MULTI (1U << 1) |
| #define BPF_F_REPLACE (1U << 2) |
| |
| /* If BPF_F_STRICT_ALIGNMENT is used in BPF_PROG_LOAD command, the |
| * verifier will perform strict alignment checking as if the kernel |
| * has been built with CONFIG_EFFICIENT_UNALIGNED_ACCESS not set, |
| * and NET_IP_ALIGN defined to 2. |
| */ |
| #define BPF_F_STRICT_ALIGNMENT (1U << 0) |
| |
| /* If BPF_F_ANY_ALIGNMENT is used in BPF_PROF_LOAD command, the |
| * verifier will allow any alignment whatsoever. On platforms |
| * with strict alignment requirements for loads ands stores (such |
| * as sparc and mips) the verifier validates that all loads and |
| * stores provably follow this requirement. This flag turns that |
| * checking and enforcement off. |
| * |
| * It is mostly used for testing when we want to validate the |
| * context and memory access aspects of the verifier, but because |
| * of an unaligned access the alignment check would trigger before |
| * the one we are interested in. |
| */ |
| #define BPF_F_ANY_ALIGNMENT (1U << 1) |
| |
| /* BPF_F_TEST_RND_HI32 is used in BPF_PROG_LOAD command for testing purpose. |
| * Verifier does sub-register def/use analysis and identifies instructions whose |
| * def only matters for low 32-bit, high 32-bit is never referenced later |
| * through implicit zero extension. Therefore verifier notifies JIT back-ends |
| * that it is safe to ignore clearing high 32-bit for these instructions. This |
| * saves some back-ends a lot of code-gen. However such optimization is not |
| * necessary on some arches, for example x86_64, arm64 etc, whose JIT back-ends |
| * hence hasn't used verifier's analysis result. But, we really want to have a |
| * way to be able to verify the correctness of the described optimization on |
| * x86_64 on which testsuites are frequently exercised. |
| * |
| * So, this flag is introduced. Once it is set, verifier will randomize high |
| * 32-bit for those instructions who has been identified as safe to ignore them. |
| * Then, if verifier is not doing correct analysis, such randomization will |
| * regress tests to expose bugs. |
| */ |
| #define BPF_F_TEST_RND_HI32 (1U << 2) |
| |
| /* The verifier internal test flag. Behavior is undefined */ |
| #define BPF_F_TEST_STATE_FREQ (1U << 3) |
| |
| /* If BPF_F_SLEEPABLE is used in BPF_PROG_LOAD command, the verifier will |
| * restrict map and helper usage for such programs. Sleepable BPF programs can |
| * only be attached to hooks where kernel execution context allows sleeping. |
| * Such programs are allowed to use helpers that may sleep like |
| * bpf_copy_from_user(). |
| */ |
| #define BPF_F_SLEEPABLE (1U << 4) |
| |
| /* When BPF ldimm64's insn[0].src_reg != 0 then this can have |
| * the following extensions: |
| * |
| * insn[0].src_reg: BPF_PSEUDO_MAP_[FD|IDX] |
| * insn[0].imm: map fd or fd_idx |
| * insn[1].imm: 0 |
| * insn[0].off: 0 |
| * insn[1].off: 0 |
| * ldimm64 rewrite: address of map |
| * verifier type: CONST_PTR_TO_MAP |
| */ |
| #define BPF_PSEUDO_MAP_FD 1 |
| #define BPF_PSEUDO_MAP_IDX 5 |
| |
| /* insn[0].src_reg: BPF_PSEUDO_MAP_[IDX_]VALUE |
| * insn[0].imm: map fd or fd_idx |
| * insn[1].imm: offset into value |
| * insn[0].off: 0 |
| * insn[1].off: 0 |
| * ldimm64 rewrite: address of map[0]+offset |
| * verifier type: PTR_TO_MAP_VALUE |
| */ |
| #define BPF_PSEUDO_MAP_VALUE 2 |
| #define BPF_PSEUDO_MAP_IDX_VALUE 6 |
| |
| /* insn[0].src_reg: BPF_PSEUDO_BTF_ID |
| * insn[0].imm: kernel btd id of VAR |
| * insn[1].imm: 0 |
| * insn[0].off: 0 |
| * insn[1].off: 0 |
| * ldimm64 rewrite: address of the kernel variable |
| * verifier type: PTR_TO_BTF_ID or PTR_TO_MEM, depending on whether the var |
| * is struct/union. |
| */ |
| #define BPF_PSEUDO_BTF_ID 3 |
| /* insn[0].src_reg: BPF_PSEUDO_FUNC |
| * insn[0].imm: insn offset to the func |
| * insn[1].imm: 0 |
| * insn[0].off: 0 |
| * insn[1].off: 0 |
| * ldimm64 rewrite: address of the function |
| * verifier type: PTR_TO_FUNC. |
| */ |
| #define BPF_PSEUDO_FUNC 4 |
| |
| /* when bpf_call->src_reg == BPF_PSEUDO_CALL, bpf_call->imm == pc-relative |
| * offset to another bpf function |
| */ |
| #define BPF_PSEUDO_CALL 1 |
| /* when bpf_call->src_reg == BPF_PSEUDO_KFUNC_CALL, |
| * bpf_call->imm == btf_id of a BTF_KIND_FUNC in the running kernel |
| */ |
| #define BPF_PSEUDO_KFUNC_CALL 2 |
| |
| /* flags for BPF_MAP_UPDATE_ELEM command */ |
| enum { |
| BPF_ANY = 0, /* create new element or update existing */ |
| BPF_NOEXIST = 1, /* create new element if it didn't exist */ |
| BPF_EXIST = 2, /* update existing element */ |
| BPF_F_LOCK = 4, /* spin_lock-ed map_lookup/map_update */ |
| }; |
| |
| /* flags for BPF_MAP_CREATE command */ |
| enum { |
| BPF_F_NO_PREALLOC = (1U << 0), |
| /* Instead of having one common LRU list in the |
| * BPF_MAP_TYPE_LRU_[PERCPU_]HASH map, use a percpu LRU list |
| * which can scale and perform better. |
| * Note, the LRU nodes (including free nodes) cannot be moved |
| * across different LRU lists. |
| */ |
| BPF_F_NO_COMMON_LRU = (1U << 1), |
| /* Specify numa node during map creation */ |
| BPF_F_NUMA_NODE = (1U << 2), |
| |
| /* Flags for accessing BPF object from syscall side. */ |
| BPF_F_RDONLY = (1U << 3), |
| BPF_F_WRONLY = (1U << 4), |
| |
| /* Flag for stack_map, store build_id+offset instead of pointer */ |
| BPF_F_STACK_BUILD_ID = (1U << 5), |
| |
| /* Zero-initialize hash function seed. This should only be used for testing. */ |
| BPF_F_ZERO_SEED = (1U << 6), |
| |
| /* Flags for accessing BPF object from program side. */ |
| BPF_F_RDONLY_PROG = (1U << 7), |
| BPF_F_WRONLY_PROG = (1U << 8), |
| |
| /* Clone map from listener for newly accepted socket */ |
| BPF_F_CLONE = (1U << 9), |
| |
| /* Enable memory-mapping BPF map */ |
| BPF_F_MMAPABLE = (1U << 10), |
| |
| /* Share perf_event among processes */ |
| BPF_F_PRESERVE_ELEMS = (1U << 11), |
| |
| /* Create a map that is suitable to be an inner map with dynamic max entries */ |
| BPF_F_INNER_MAP = (1U << 12), |
| }; |
| |
| /* Flags for BPF_PROG_QUERY. */ |
| |
| /* Query effective (directly attached + inherited from ancestor cgroups) |
| * programs that will be executed for events within a cgroup. |
| * attach_flags with this flag are returned only for directly attached programs. |
| */ |
| #define BPF_F_QUERY_EFFECTIVE (1U << 0) |
| |
| /* Flags for BPF_PROG_TEST_RUN */ |
| |
| /* If set, run the test on the cpu specified by bpf_attr.test.cpu */ |
| #define BPF_F_TEST_RUN_ON_CPU (1U << 0) |
| |
| /* type for BPF_ENABLE_STATS */ |
| enum bpf_stats_type { |
| /* enabled run_time_ns and run_cnt */ |
| BPF_STATS_RUN_TIME = 0, |
| }; |
| |
| enum bpf_stack_build_id_status { |
| /* user space need an empty entry to identify end of a trace */ |
| BPF_STACK_BUILD_ID_EMPTY = 0, |
| /* with valid build_id and offset */ |
| BPF_STACK_BUILD_ID_VALID = 1, |
| /* couldn't get build_id, fallback to ip */ |
| BPF_STACK_BUILD_ID_IP = 2, |
| }; |
| |
| #define BPF_BUILD_ID_SIZE 20 |
| struct bpf_stack_build_id { |
| __s32 status; |
| unsigned char build_id[BPF_BUILD_ID_SIZE]; |
| union { |
| __u64 offset; |
| __u64 ip; |
| }; |
| }; |
| |
| #define BPF_OBJ_NAME_LEN 16U |
| |
| union bpf_attr { |
| struct { /* anonymous struct used by BPF_MAP_CREATE command */ |
| __u32 map_type; /* one of enum bpf_map_type */ |
| __u32 key_size; /* size of key in bytes */ |
| __u32 value_size; /* size of value in bytes */ |
| __u32 max_entries; /* max number of entries in a map */ |
| __u32 map_flags; /* BPF_MAP_CREATE related |
| * flags defined above. |
| */ |
| __u32 inner_map_fd; /* fd pointing to the inner map */ |
| __u32 numa_node; /* numa node (effective only if |
| * BPF_F_NUMA_NODE is set). |
| */ |
| char map_name[BPF_OBJ_NAME_LEN]; |
| __u32 map_ifindex; /* ifindex of netdev to create on */ |
| __u32 btf_fd; /* fd pointing to a BTF type data */ |
| __u32 btf_key_type_id; /* BTF type_id of the key */ |
| __u32 btf_value_type_id; /* BTF type_id of the value */ |
| __u32 btf_vmlinux_value_type_id;/* BTF type_id of a kernel- |
| * struct stored as the |
| * map value |
| */ |
| }; |
| |
| struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */ |
| __u32 map_fd; |
| __aligned_u64 key; |
| union { |
| __aligned_u64 value; |
| __aligned_u64 next_key; |
| }; |
| __u64 flags; |
| }; |
| |
| struct { /* struct used by BPF_MAP_*_BATCH commands */ |
| __aligned_u64 in_batch; /* start batch, |
| * NULL to start from beginning |
| */ |
| __aligned_u64 out_batch; /* output: next start batch */ |
| __aligned_u64 keys; |
| __aligned_u64 values; |
| __u32 count; /* input/output: |
| * input: # of key/value |
| * elements |
| * output: # of filled elements |
| */ |
| __u32 map_fd; |
| __u64 elem_flags; |
| __u64 flags; |
| } batch; |
| |
| struct { /* anonymous struct used by BPF_PROG_LOAD command */ |
| __u32 prog_type; /* one of enum bpf_prog_type */ |
| __u32 insn_cnt; |
| __aligned_u64 insns; |
| __aligned_u64 license; |
| __u32 log_level; /* verbosity level of verifier */ |
| __u32 log_size; /* size of user buffer */ |
| __aligned_u64 log_buf; /* user supplied buffer */ |
| __u32 kern_version; /* not used */ |
| __u32 prog_flags; |
| char prog_name[BPF_OBJ_NAME_LEN]; |
| __u32 prog_ifindex; /* ifindex of netdev to prep for */ |
| /* For some prog types expected attach type must be known at |
| * load time to verify attach type specific parts of prog |
| * (context accesses, allowed helpers, etc). |
| */ |
| __u32 expected_attach_type; |
| __u32 prog_btf_fd; /* fd pointing to BTF type data */ |
| __u32 func_info_rec_size; /* userspace bpf_func_info size */ |
| __aligned_u64 func_info; /* func info */ |
| __u32 func_info_cnt; /* number of bpf_func_info records */ |
| __u32 line_info_rec_size; /* userspace bpf_line_info size */ |
| __aligned_u64 line_info; /* line info */ |
| __u32 line_info_cnt; /* number of bpf_line_info records */ |
| __u32 attach_btf_id; /* in-kernel BTF type id to attach to */ |
| union { |
| /* valid prog_fd to attach to bpf prog */ |
| __u32 attach_prog_fd; |
| /* or valid module BTF object fd or 0 to attach to vmlinux */ |
| __u32 attach_btf_obj_fd; |
| }; |
| __u32 :32; /* pad */ |
| __aligned_u64 fd_array; /* array of FDs */ |
| }; |
| |
| struct { /* anonymous struct used by BPF_OBJ_* commands */ |
| __aligned_u64 pathname; |
| __u32 bpf_fd; |
| __u32 file_flags; |
| }; |
| |
| struct { /* anonymous struct used by BPF_PROG_ATTACH/DETACH commands */ |
| __u32 target_fd; /* container object to attach to */ |
| __u32 attach_bpf_fd; /* eBPF program to attach */ |
| __u32 attach_type; |
| __u32 attach_flags; |
| __u32 replace_bpf_fd; /* previously attached eBPF |
| * program to replace if |
| * BPF_F_REPLACE is used |
| */ |
| }; |
| |
| struct { /* anonymous struct used by BPF_PROG_TEST_RUN command */ |
| __u32 prog_fd; |
| __u32 retval; |
| __u32 data_size_in; /* input: len of data_in */ |
| __u32 data_size_out; /* input/output: len of data_out |
| * returns ENOSPC if data_out |
| * is too small. |
| */ |
| __aligned_u64 data_in; |
| __aligned_u64 data_out; |
| __u32 repeat; |
| __u32 duration; |
| __u32 ctx_size_in; /* input: len of ctx_in */ |
| __u32 ctx_size_out; /* input/output: len of ctx_out |
| * returns ENOSPC if ctx_out |
| * is too small. |
| */ |
| __aligned_u64 ctx_in; |
| __aligned_u64 ctx_out; |
| __u32 flags; |
| __u32 cpu; |
| } test; |
| |
| struct { /* anonymous struct used by BPF_*_GET_*_ID */ |
| union { |
| __u32 start_id; |
| __u32 prog_id; |
| __u32 map_id; |
| __u32 btf_id; |
| __u32 link_id; |
| }; |
| __u32 next_id; |
| __u32 open_flags; |
| }; |
| |
| struct { /* anonymous struct used by BPF_OBJ_GET_INFO_BY_FD */ |
| __u32 bpf_fd; |
| __u32 info_len; |
| __aligned_u64 info; |
| } info; |
| |
| struct { /* anonymous struct used by BPF_PROG_QUERY command */ |
| __u32 target_fd; /* container object to query */ |
| __u32 attach_type; |
| __u32 query_flags; |
| __u32 attach_flags; |
| __aligned_u64 prog_ids; |
| __u32 prog_cnt; |
| } query; |
| |
| struct { /* anonymous struct used by BPF_RAW_TRACEPOINT_OPEN command */ |
| __u64 name; |
| __u32 prog_fd; |
| } raw_tracepoint; |
| |
| struct { /* anonymous struct for BPF_BTF_LOAD */ |
| __aligned_u64 btf; |
| __aligned_u64 btf_log_buf; |
| __u32 btf_size; |
| __u32 btf_log_size; |
| __u32 btf_log_level; |
| }; |
| |
| struct { |
| __u32 pid; /* input: pid */ |
| __u32 fd; /* input: fd */ |
| __u32 flags; /* input: flags */ |
| __u32 buf_len; /* input/output: buf len */ |
| __aligned_u64 buf; /* input/output: |
| * tp_name for tracepoint |
| * symbol for kprobe |
| * filename for uprobe |
| */ |
| __u32 prog_id; /* output: prod_id */ |
| __u32 fd_type; /* output: BPF_FD_TYPE_* */ |
| __u64 probe_offset; /* output: probe_offset */ |
| __u64 probe_addr; /* output: probe_addr */ |
| } task_fd_query; |
| |
| struct { /* struct used by BPF_LINK_CREATE command */ |
| __u32 prog_fd; /* eBPF program to attach */ |
| union { |
| __u32 target_fd; /* object to attach to */ |
| __u32 target_ifindex; /* target ifindex */ |
| }; |
| __u32 attach_type; /* attach type */ |
| __u32 flags; /* extra flags */ |
| union { |
| __u32 target_btf_id; /* btf_id of target to attach to */ |
| struct { |
| __aligned_u64 iter_info; /* extra bpf_iter_link_info */ |
| __u32 iter_info_len; /* iter_info length */ |
| }; |
| }; |
| } link_create; |
| |
| struct { /* struct used by BPF_LINK_UPDATE command */ |
| __u32 link_fd; /* link fd */ |
| /* new program fd to update link with */ |
| __u32 new_prog_fd; |
| __u32 flags; /* extra flags */ |
| /* expected link's program fd; is specified only if |
| * BPF_F_REPLACE flag is set in flags */ |
| __u32 old_prog_fd; |
| } link_update; |
| |
| struct { |
| __u32 link_fd; |
| } link_detach; |
| |
| struct { /* struct used by BPF_ENABLE_STATS command */ |
| __u32 type; |
| } enable_stats; |
| |
| struct { /* struct used by BPF_ITER_CREATE command */ |
| __u32 link_fd; |
| __u32 flags; |
| } iter_create; |
| |
| struct { /* struct used by BPF_PROG_BIND_MAP command */ |
| __u32 prog_fd; |
| __u32 map_fd; |
| __u32 flags; /* extra flags */ |
| } prog_bind_map; |
| |
| } __attribute__((aligned(8))); |
| |
| /* The description below is an attempt at providing documentation to eBPF |
| * developers about the multiple available eBPF helper functions. It can be |
| * parsed and used to produce a manual page. The workflow is the following, |
| * and requires the rst2man utility: |
| * |
| * $ ./scripts/bpf_doc.py \ |
| * --filename include/uapi/linux/bpf.h > /tmp/bpf-helpers.rst |
| * $ rst2man /tmp/bpf-helpers.rst > /tmp/bpf-helpers.7 |
| * $ man /tmp/bpf-helpers.7 |
| * |
| * Note that in order to produce this external documentation, some RST |
| * formatting is used in the descriptions to get "bold" and "italics" in |
| * manual pages. Also note that the few trailing white spaces are |
| * intentional, removing them would break paragraphs for rst2man. |
| * |
| * Start of BPF helper function descriptions: |
| * |
| * void *bpf_map_lookup_elem(struct bpf_map *map, const void *key) |
| * Description |
| * Perform a lookup in *map* for an entry associated to *key*. |
| * Return |
| * Map value associated to *key*, or **NULL** if no entry was |
| * found. |
| * |
| * long bpf_map_update_elem(struct bpf_map *map, const void *key, const void *value, u64 flags) |
| * Description |
| * Add or update the value of the entry associated to *key* in |
| * *map* with *value*. *flags* is one of: |
| * |
| * **BPF_NOEXIST** |
| * The entry for *key* must not exist in the map. |
| * **BPF_EXIST** |
| * The entry for *key* must already exist in the map. |
| * **BPF_ANY** |
| * No condition on the existence of the entry for *key*. |
| * |
| * Flag value **BPF_NOEXIST** cannot be used for maps of types |
| * **BPF_MAP_TYPE_ARRAY** or **BPF_MAP_TYPE_PERCPU_ARRAY** (all |
| * elements always exist), the helper would return an error. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_map_delete_elem(struct bpf_map *map, const void *key) |
| * Description |
| * Delete entry with *key* from *map*. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_probe_read(void *dst, u32 size, const void *unsafe_ptr) |
| * Description |
| * For tracing programs, safely attempt to read *size* bytes from |
| * kernel space address *unsafe_ptr* and store the data in *dst*. |
| * |
| * Generally, use **bpf_probe_read_user**\ () or |
| * **bpf_probe_read_kernel**\ () instead. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * u64 bpf_ktime_get_ns(void) |
| * Description |
| * Return the time elapsed since system boot, in nanoseconds. |
| * Does not include time the system was suspended. |
| * See: **clock_gettime**\ (**CLOCK_MONOTONIC**) |
| * Return |
| * Current *ktime*. |
| * |
| * long bpf_trace_printk(const char *fmt, u32 fmt_size, ...) |
| * Description |
| * This helper is a "printk()-like" facility for debugging. It |
| * prints a message defined by format *fmt* (of size *fmt_size*) |
| * to file *\/sys/kernel/debug/tracing/trace* from DebugFS, if |
| * available. It can take up to three additional **u64** |
| * arguments (as an eBPF helpers, the total number of arguments is |
| * limited to five). |
| * |
| * Each time the helper is called, it appends a line to the trace. |
| * Lines are discarded while *\/sys/kernel/debug/tracing/trace* is |
| * open, use *\/sys/kernel/debug/tracing/trace_pipe* to avoid this. |
| * The format of the trace is customizable, and the exact output |
| * one will get depends on the options set in |
| * *\/sys/kernel/debug/tracing/trace_options* (see also the |
| * *README* file under the same directory). However, it usually |
| * defaults to something like: |
| * |
| * :: |
| * |
| * telnet-470 [001] .N.. 419421.045894: 0x00000001: <formatted msg> |
| * |
| * In the above: |
| * |
| * * ``telnet`` is the name of the current task. |
| * * ``470`` is the PID of the current task. |
| * * ``001`` is the CPU number on which the task is |
| * running. |
| * * In ``.N..``, each character refers to a set of |
| * options (whether irqs are enabled, scheduling |
| * options, whether hard/softirqs are running, level of |
| * preempt_disabled respectively). **N** means that |
| * **TIF_NEED_RESCHED** and **PREEMPT_NEED_RESCHED** |
| * are set. |
| * * ``419421.045894`` is a timestamp. |
| * * ``0x00000001`` is a fake value used by BPF for the |
| * instruction pointer register. |
| * * ``<formatted msg>`` is the message formatted with |
| * *fmt*. |
| * |
| * The conversion specifiers supported by *fmt* are similar, but |
| * more limited than for printk(). They are **%d**, **%i**, |
| * **%u**, **%x**, **%ld**, **%li**, **%lu**, **%lx**, **%lld**, |
| * **%lli**, **%llu**, **%llx**, **%p**, **%s**. No modifier (size |
| * of field, padding with zeroes, etc.) is available, and the |
| * helper will return **-EINVAL** (but print nothing) if it |
| * encounters an unknown specifier. |
| * |
| * Also, note that **bpf_trace_printk**\ () is slow, and should |
| * only be used for debugging purposes. For this reason, a notice |
| * block (spanning several lines) is printed to kernel logs and |
| * states that the helper should not be used "for production use" |
| * the first time this helper is used (or more precisely, when |
| * **trace_printk**\ () buffers are allocated). For passing values |
| * to user space, perf events should be preferred. |
| * Return |
| * The number of bytes written to the buffer, or a negative error |
| * in case of failure. |
| * |
| * u32 bpf_get_prandom_u32(void) |
| * Description |
| * Get a pseudo-random number. |
| * |
| * From a security point of view, this helper uses its own |
| * pseudo-random internal state, and cannot be used to infer the |
| * seed of other random functions in the kernel. However, it is |
| * essential to note that the generator used by the helper is not |
| * cryptographically secure. |
| * Return |
| * A random 32-bit unsigned value. |
| * |
| * u32 bpf_get_smp_processor_id(void) |
| * Description |
| * Get the SMP (symmetric multiprocessing) processor id. Note that |
| * all programs run with preemption disabled, which means that the |
| * SMP processor id is stable during all the execution of the |
| * program. |
| * Return |
| * The SMP id of the processor running the program. |
| * |
| * long bpf_skb_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len, u64 flags) |
| * Description |
| * Store *len* bytes from address *from* into the packet |
| * associated to *skb*, at *offset*. *flags* are a combination of |
| * **BPF_F_RECOMPUTE_CSUM** (automatically recompute the |
| * checksum for the packet after storing the bytes) and |
| * **BPF_F_INVALIDATE_HASH** (set *skb*\ **->hash**, *skb*\ |
| * **->swhash** and *skb*\ **->l4hash** to 0). |
| * |
| * A call to this helper is susceptible to change the underlying |
| * packet buffer. Therefore, at load time, all checks on pointers |
| * previously done by the verifier are invalidated and must be |
| * performed again, if the helper is used in combination with |
| * direct packet access. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_l3_csum_replace(struct sk_buff *skb, u32 offset, u64 from, u64 to, u64 size) |
| * Description |
| * Recompute the layer 3 (e.g. IP) checksum for the packet |
| * associated to *skb*. Computation is incremental, so the helper |
| * must know the former value of the header field that was |
| * modified (*from*), the new value of this field (*to*), and the |
| * number of bytes (2 or 4) for this field, stored in *size*. |
| * Alternatively, it is possible to store the difference between |
| * the previous and the new values of the header field in *to*, by |
| * setting *from* and *size* to 0. For both methods, *offset* |
| * indicates the location of the IP checksum within the packet. |
| * |
| * This helper works in combination with **bpf_csum_diff**\ (), |
| * which does not update the checksum in-place, but offers more |
| * flexibility and can handle sizes larger than 2 or 4 for the |
| * checksum to update. |
| * |
| * A call to this helper is susceptible to change the underlying |
| * packet buffer. Therefore, at load time, all checks on pointers |
| * previously done by the verifier are invalidated and must be |
| * performed again, if the helper is used in combination with |
| * direct packet access. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_l4_csum_replace(struct sk_buff *skb, u32 offset, u64 from, u64 to, u64 flags) |
| * Description |
| * Recompute the layer 4 (e.g. TCP, UDP or ICMP) checksum for the |
| * packet associated to *skb*. Computation is incremental, so the |
| * helper must know the former value of the header field that was |
| * modified (*from*), the new value of this field (*to*), and the |
| * number of bytes (2 or 4) for this field, stored on the lowest |
| * four bits of *flags*. Alternatively, it is possible to store |
| * the difference between the previous and the new values of the |
| * header field in *to*, by setting *from* and the four lowest |
| * bits of *flags* to 0. For both methods, *offset* indicates the |
| * location of the IP checksum within the packet. In addition to |
| * the size of the field, *flags* can be added (bitwise OR) actual |
| * flags. With **BPF_F_MARK_MANGLED_0**, a null checksum is left |
| * untouched (unless **BPF_F_MARK_ENFORCE** is added as well), and |
| * for updates resulting in a null checksum the value is set to |
| * **CSUM_MANGLED_0** instead. Flag **BPF_F_PSEUDO_HDR** indicates |
| * the checksum is to be computed against a pseudo-header. |
| * |
| * This helper works in combination with **bpf_csum_diff**\ (), |
| * which does not update the checksum in-place, but offers more |
| * flexibility and can handle sizes larger than 2 or 4 for the |
| * checksum to update. |
| * |
| * A call to this helper is susceptible to change the underlying |
| * packet buffer. Therefore, at load time, all checks on pointers |
| * previously done by the verifier are invalidated and must be |
| * performed again, if the helper is used in combination with |
| * direct packet access. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_tail_call(void *ctx, struct bpf_map *prog_array_map, u32 index) |
| * Description |
| * This special helper is used to trigger a "tail call", or in |
| * other words, to jump into another eBPF program. The same stack |
| * frame is used (but values on stack and in registers for the |
| * caller are not accessible to the callee). This mechanism allows |
| * for program chaining, either for raising the maximum number of |
| * available eBPF instructions, or to execute given programs in |
| * conditional blocks. For security reasons, there is an upper |
| * limit to the number of successive tail calls that can be |
| * performed. |
| * |
| * Upon call of this helper, the program attempts to jump into a |
| * program referenced at index *index* in *prog_array_map*, a |
| * special map of type **BPF_MAP_TYPE_PROG_ARRAY**, and passes |
| * *ctx*, a pointer to the context. |
| * |
| * If the call succeeds, the kernel immediately runs the first |
| * instruction of the new program. This is not a function call, |
| * and it never returns to the previous program. If the call |
| * fails, then the helper has no effect, and the caller continues |
| * to run its subsequent instructions. A call can fail if the |
| * destination program for the jump does not exist (i.e. *index* |
| * is superior to the number of entries in *prog_array_map*), or |
| * if the maximum number of tail calls has been reached for this |
| * chain of programs. This limit is defined in the kernel by the |
| * macro **MAX_TAIL_CALL_CNT** (not accessible to user space), |
| * which is currently set to 32. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_clone_redirect(struct sk_buff *skb, u32 ifindex, u64 flags) |
| * Description |
| * Clone and redirect the packet associated to *skb* to another |
| * net device of index *ifindex*. Both ingress and egress |
| * interfaces can be used for redirection. The **BPF_F_INGRESS** |
| * value in *flags* is used to make the distinction (ingress path |
| * is selected if the flag is present, egress path otherwise). |
| * This is the only flag supported for now. |
| * |
| * In comparison with **bpf_redirect**\ () helper, |
| * **bpf_clone_redirect**\ () has the associated cost of |
| * duplicating the packet buffer, but this can be executed out of |
| * the eBPF program. Conversely, **bpf_redirect**\ () is more |
| * efficient, but it is handled through an action code where the |
| * redirection happens only after the eBPF program has returned. |
| * |
| * A call to this helper is susceptible to change the underlying |
| * packet buffer. Therefore, at load time, all checks on pointers |
| * previously done by the verifier are invalidated and must be |
| * performed again, if the helper is used in combination with |
| * direct packet access. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * u64 bpf_get_current_pid_tgid(void) |
| * Return |
| * A 64-bit integer containing the current tgid and pid, and |
| * created as such: |
| * *current_task*\ **->tgid << 32 \|** |
| * *current_task*\ **->pid**. |
| * |
| * u64 bpf_get_current_uid_gid(void) |
| * Return |
| * A 64-bit integer containing the current GID and UID, and |
| * created as such: *current_gid* **<< 32 \|** *current_uid*. |
| * |
| * long bpf_get_current_comm(void *buf, u32 size_of_buf) |
| * Description |
| * Copy the **comm** attribute of the current task into *buf* of |
| * *size_of_buf*. The **comm** attribute contains the name of |
| * the executable (excluding the path) for the current task. The |
| * *size_of_buf* must be strictly positive. On success, the |
| * helper makes sure that the *buf* is NUL-terminated. On failure, |
| * it is filled with zeroes. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * u32 bpf_get_cgroup_classid(struct sk_buff *skb) |
| * Description |
| * Retrieve the classid for the current task, i.e. for the net_cls |
| * cgroup to which *skb* belongs. |
| * |
| * This helper can be used on TC egress path, but not on ingress. |
| * |
| * The net_cls cgroup provides an interface to tag network packets |
| * based on a user-provided identifier for all traffic coming from |
| * the tasks belonging to the related cgroup. See also the related |
| * kernel documentation, available from the Linux sources in file |
| * *Documentation/admin-guide/cgroup-v1/net_cls.rst*. |
| * |
| * The Linux kernel has two versions for cgroups: there are |
| * cgroups v1 and cgroups v2. Both are available to users, who can |
| * use a mixture of them, but note that the net_cls cgroup is for |
| * cgroup v1 only. This makes it incompatible with BPF programs |
| * run on cgroups, which is a cgroup-v2-only feature (a socket can |
| * only hold data for one version of cgroups at a time). |
| * |
| * This helper is only available is the kernel was compiled with |
| * the **CONFIG_CGROUP_NET_CLASSID** configuration option set to |
| * "**y**" or to "**m**". |
| * Return |
| * The classid, or 0 for the default unconfigured classid. |
| * |
| * long bpf_skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci) |
| * Description |
| * Push a *vlan_tci* (VLAN tag control information) of protocol |
| * *vlan_proto* to the packet associated to *skb*, then update |
| * the checksum. Note that if *vlan_proto* is different from |
| * **ETH_P_8021Q** and **ETH_P_8021AD**, it is considered to |
| * be **ETH_P_8021Q**. |
| * |
| * A call to this helper is susceptible to change the underlying |
| * packet buffer. Therefore, at load time, all checks on pointers |
| * previously done by the verifier are invalidated and must be |
| * performed again, if the helper is used in combination with |
| * direct packet access. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_skb_vlan_pop(struct sk_buff *skb) |
| * Description |
| * Pop a VLAN header from the packet associated to *skb*. |
| * |
| * A call to this helper is susceptible to change the underlying |
| * packet buffer. Therefore, at load time, all checks on pointers |
| * previously done by the verifier are invalidated and must be |
| * performed again, if the helper is used in combination with |
| * direct packet access. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_skb_get_tunnel_key(struct sk_buff *skb, struct bpf_tunnel_key *key, u32 size, u64 flags) |
| * Description |
| * Get tunnel metadata. This helper takes a pointer *key* to an |
| * empty **struct bpf_tunnel_key** of **size**, that will be |
| * filled with tunnel metadata for the packet associated to *skb*. |
| * The *flags* can be set to **BPF_F_TUNINFO_IPV6**, which |
| * indicates that the tunnel is based on IPv6 protocol instead of |
| * IPv4. |
| * |
| * The **struct bpf_tunnel_key** is an object that generalizes the |
| * principal parameters used by various tunneling protocols into a |
| * single struct. This way, it can be used to easily make a |
| * decision based on the contents of the encapsulation header, |
| * "summarized" in this struct. In particular, it holds the IP |
| * address of the remote end (IPv4 or IPv6, depending on the case) |
| * in *key*\ **->remote_ipv4** or *key*\ **->remote_ipv6**. Also, |
| * this struct exposes the *key*\ **->tunnel_id**, which is |
| * generally mapped to a VNI (Virtual Network Identifier), making |
| * it programmable together with the **bpf_skb_set_tunnel_key**\ |
| * () helper. |
| * |
| * Let's imagine that the following code is part of a program |
| * attached to the TC ingress interface, on one end of a GRE |
| * tunnel, and is supposed to filter out all messages coming from |
| * remote ends with IPv4 address other than 10.0.0.1: |
| * |
| * :: |
| * |
| * int ret; |
| * struct bpf_tunnel_key key = {}; |
| * |
| * ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0); |
| * if (ret < 0) |
| * return TC_ACT_SHOT; // drop packet |
| * |
| * if (key.remote_ipv4 != 0x0a000001) |
| * return TC_ACT_SHOT; // drop packet |
| * |
| * return TC_ACT_OK; // accept packet |
| * |
| * This interface can also be used with all encapsulation devices |
| * that can operate in "collect metadata" mode: instead of having |
| * one network device per specific configuration, the "collect |
| * metadata" mode only requires a single device where the |
| * configuration can be extracted from this helper. |
| * |
| * This can be used together with various tunnels such as VXLan, |
| * Geneve, GRE or IP in IP (IPIP). |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_skb_set_tunnel_key(struct sk_buff *skb, struct bpf_tunnel_key *key, u32 size, u64 flags) |
| * Description |
| * Populate tunnel metadata for packet associated to *skb.* The |
| * tunnel metadata is set to the contents of *key*, of *size*. The |
| * *flags* can be set to a combination of the following values: |
| * |
| * **BPF_F_TUNINFO_IPV6** |
| * Indicate that the tunnel is based on IPv6 protocol |
| * instead of IPv4. |
| * **BPF_F_ZERO_CSUM_TX** |
| * For IPv4 packets, add a flag to tunnel metadata |
| * indicating that checksum computation should be skipped |
| * and checksum set to zeroes. |
| * **BPF_F_DONT_FRAGMENT** |
| * Add a flag to tunnel metadata indicating that the |
| * packet should not be fragmented. |
| * **BPF_F_SEQ_NUMBER** |
| * Add a flag to tunnel metadata indicating that a |
| * sequence number should be added to tunnel header before |
| * sending the packet. This flag was added for GRE |
| * encapsulation, but might be used with other protocols |
| * as well in the future. |
| * |
| * Here is a typical usage on the transmit path: |
| * |
| * :: |
| * |
| * struct bpf_tunnel_key key; |
| * populate key ... |
| * bpf_skb_set_tunnel_key(skb, &key, sizeof(key), 0); |
| * bpf_clone_redirect(skb, vxlan_dev_ifindex, 0); |
| * |
| * See also the description of the **bpf_skb_get_tunnel_key**\ () |
| * helper for additional information. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * u64 bpf_perf_event_read(struct bpf_map *map, u64 flags) |
| * Description |
| * Read the value of a perf event counter. This helper relies on a |
| * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of |
| * the perf event counter is selected when *map* is updated with |
| * perf event file descriptors. The *map* is an array whose size |
| * is the number of available CPUs, and each cell contains a value |
| * relative to one CPU. The value to retrieve is indicated by |
| * *flags*, that contains the index of the CPU to look up, masked |
| * with **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to |
| * **BPF_F_CURRENT_CPU** to indicate that the value for the |
| * current CPU should be retrieved. |
| * |
| * Note that before Linux 4.13, only hardware perf event can be |
| * retrieved. |
| * |
| * Also, be aware that the newer helper |
| * **bpf_perf_event_read_value**\ () is recommended over |
| * **bpf_perf_event_read**\ () in general. The latter has some ABI |
| * quirks where error and counter value are used as a return code |
| * (which is wrong to do since ranges may overlap). This issue is |
| * fixed with **bpf_perf_event_read_value**\ (), which at the same |
| * time provides more features over the **bpf_perf_event_read**\ |
| * () interface. Please refer to the description of |
| * **bpf_perf_event_read_value**\ () for details. |
| * Return |
| * The value of the perf event counter read from the map, or a |
| * negative error code in case of failure. |
| * |
| * long bpf_redirect(u32 ifindex, u64 flags) |
| * Description |
| * Redirect the packet to another net device of index *ifindex*. |
| * This helper is somewhat similar to **bpf_clone_redirect**\ |
| * (), except that the packet is not cloned, which provides |
| * increased performance. |
| * |
| * Except for XDP, both ingress and egress interfaces can be used |
| * for redirection. The **BPF_F_INGRESS** value in *flags* is used |
| * to make the distinction (ingress path is selected if the flag |
| * is present, egress path otherwise). Currently, XDP only |
| * supports redirection to the egress interface, and accepts no |
| * flag at all. |
| * |
| * The same effect can also be attained with the more generic |
| * **bpf_redirect_map**\ (), which uses a BPF map to store the |
| * redirect target instead of providing it directly to the helper. |
| * Return |
| * For XDP, the helper returns **XDP_REDIRECT** on success or |
| * **XDP_ABORTED** on error. For other program types, the values |
| * are **TC_ACT_REDIRECT** on success or **TC_ACT_SHOT** on |
| * error. |
| * |
| * u32 bpf_get_route_realm(struct sk_buff *skb) |
| * Description |
| * Retrieve the realm or the route, that is to say the |
| * **tclassid** field of the destination for the *skb*. The |
| * identifier retrieved is a user-provided tag, similar to the |
| * one used with the net_cls cgroup (see description for |
| * **bpf_get_cgroup_classid**\ () helper), but here this tag is |
| * held by a route (a destination entry), not by a task. |
| * |
| * Retrieving this identifier works with the clsact TC egress hook |
| * (see also **tc-bpf(8)**), or alternatively on conventional |
| * classful egress qdiscs, but not on TC ingress path. In case of |
| * clsact TC egress hook, this has the advantage that, internally, |
| * the destination entry has not been dropped yet in the transmit |
| * path. Therefore, the destination entry does not need to be |
| * artificially held via **netif_keep_dst**\ () for a classful |
| * qdisc until the *skb* is freed. |
| * |
| * This helper is available only if the kernel was compiled with |
| * **CONFIG_IP_ROUTE_CLASSID** configuration option. |
| * Return |
| * The realm of the route for the packet associated to *skb*, or 0 |
| * if none was found. |
| * |
| * long bpf_perf_event_output(void *ctx, struct bpf_map *map, u64 flags, void *data, u64 size) |
| * Description |
| * Write raw *data* blob into a special BPF perf event held by |
| * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf |
| * event must have the following attributes: **PERF_SAMPLE_RAW** |
| * as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and |
| * **PERF_COUNT_SW_BPF_OUTPUT** as **config**. |
| * |
| * The *flags* are used to indicate the index in *map* for which |
| * the value must be put, masked with **BPF_F_INDEX_MASK**. |
| * Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU** |
| * to indicate that the index of the current CPU core should be |
| * used. |
| * |
| * The value to write, of *size*, is passed through eBPF stack and |
| * pointed by *data*. |
| * |
| * The context of the program *ctx* needs also be passed to the |
| * helper. |
| * |
| * On user space, a program willing to read the values needs to |
| * call **perf_event_open**\ () on the perf event (either for |
| * one or for all CPUs) and to store the file descriptor into the |
| * *map*. This must be done before the eBPF program can send data |
| * into it. An example is available in file |
| * *samples/bpf/trace_output_user.c* in the Linux kernel source |
| * tree (the eBPF program counterpart is in |
| * *samples/bpf/trace_output_kern.c*). |
| * |
| * **bpf_perf_event_output**\ () achieves better performance |
| * than **bpf_trace_printk**\ () for sharing data with user |
| * space, and is much better suitable for streaming data from eBPF |
| * programs. |
| * |
| * Note that this helper is not restricted to tracing use cases |
| * and can be used with programs attached to TC or XDP as well, |
| * where it allows for passing data to user space listeners. Data |
| * can be: |
| * |
| * * Only custom structs, |
| * * Only the packet payload, or |
| * * A combination of both. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_skb_load_bytes(const void *skb, u32 offset, void *to, u32 len) |
| * Description |
| * This helper was provided as an easy way to load data from a |
| * packet. It can be used to load *len* bytes from *offset* from |
| * the packet associated to *skb*, into the buffer pointed by |
| * *to*. |
| * |
| * Since Linux 4.7, usage of this helper has mostly been replaced |
| * by "direct packet access", enabling packet data to be |
| * manipulated with *skb*\ **->data** and *skb*\ **->data_end** |
| * pointing respectively to the first byte of packet data and to |
| * the byte after the last byte of packet data. However, it |
| * remains useful if one wishes to read large quantities of data |
| * at once from a packet into the eBPF stack. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_get_stackid(void *ctx, struct bpf_map *map, u64 flags) |
| * Description |
| * Walk a user or a kernel stack and return its id. To achieve |
| * this, the helper needs *ctx*, which is a pointer to the context |
| * on which the tracing program is executed, and a pointer to a |
| * *map* of type **BPF_MAP_TYPE_STACK_TRACE**. |
| * |
| * The last argument, *flags*, holds the number of stack frames to |
| * skip (from 0 to 255), masked with |
| * **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set |
| * a combination of the following flags: |
| * |
| * **BPF_F_USER_STACK** |
| * Collect a user space stack instead of a kernel stack. |
| * **BPF_F_FAST_STACK_CMP** |
| * Compare stacks by hash only. |
| * **BPF_F_REUSE_STACKID** |
| * If two different stacks hash into the same *stackid*, |
| * discard the old one. |
| * |
| * The stack id retrieved is a 32 bit long integer handle which |
| * can be further combined with other data (including other stack |
| * ids) and used as a key into maps. This can be useful for |
| * generating a variety of graphs (such as flame graphs or off-cpu |
| * graphs). |
| * |
| * For walking a stack, this helper is an improvement over |
| * **bpf_probe_read**\ (), which can be used with unrolled loops |
| * but is not efficient and consumes a lot of eBPF instructions. |
| * Instead, **bpf_get_stackid**\ () can collect up to |
| * **PERF_MAX_STACK_DEPTH** both kernel and user frames. Note that |
| * this limit can be controlled with the **sysctl** program, and |
| * that it should be manually increased in order to profile long |
| * user stacks (such as stacks for Java programs). To do so, use: |
| * |
| * :: |
| * |
| * # sysctl kernel.perf_event_max_stack=<new value> |
| * Return |
| * The positive or null stack id on success, or a negative error |
| * in case of failure. |
| * |
| * s64 bpf_csum_diff(__be32 *from, u32 from_size, __be32 *to, u32 to_size, __wsum seed) |
| * Description |
| * Compute a checksum difference, from the raw buffer pointed by |
| * *from*, of length *from_size* (that must be a multiple of 4), |
| * towards the raw buffer pointed by *to*, of size *to_size* |
| * (same remark). An optional *seed* can be added to the value |
| * (this can be cascaded, the seed may come from a previous call |
| * to the helper). |
| * |
| * This is flexible enough to be used in several ways: |
| * |
| * * With *from_size* == 0, *to_size* > 0 and *seed* set to |
| * checksum, it can be used when pushing new data. |
| * * With *from_size* > 0, *to_size* == 0 and *seed* set to |
| * checksum, it can be used when removing data from a packet. |
| * * With *from_size* > 0, *to_size* > 0 and *seed* set to 0, it |
| * can be used to compute a diff. Note that *from_size* and |
| * *to_size* do not need to be equal. |
| * |
| * This helper can be used in combination with |
| * **bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\ (), to |
| * which one can feed in the difference computed with |
| * **bpf_csum_diff**\ (). |
| * Return |
| * The checksum result, or a negative error code in case of |
| * failure. |
| * |
| * long bpf_skb_get_tunnel_opt(struct sk_buff *skb, void *opt, u32 size) |
| * Description |
| * Retrieve tunnel options metadata for the packet associated to |
| * *skb*, and store the raw tunnel option data to the buffer *opt* |
| * of *size*. |
| * |
| * This helper can be used with encapsulation devices that can |
| * operate in "collect metadata" mode (please refer to the related |
| * note in the description of **bpf_skb_get_tunnel_key**\ () for |
| * more details). A particular example where this can be used is |
| * in combination with the Geneve encapsulation protocol, where it |
| * allows for pushing (with **bpf_skb_get_tunnel_opt**\ () helper) |
| * and retrieving arbitrary TLVs (Type-Length-Value headers) from |
| * the eBPF program. This allows for full customization of these |
| * headers. |
| * Return |
| * The size of the option data retrieved. |
| * |
| * long bpf_skb_set_tunnel_opt(struct sk_buff *skb, void *opt, u32 size) |
| * Description |
| * Set tunnel options metadata for the packet associated to *skb* |
| * to the option data contained in the raw buffer *opt* of *size*. |
| * |
| * See also the description of the **bpf_skb_get_tunnel_opt**\ () |
| * helper for additional information. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_skb_change_proto(struct sk_buff *skb, __be16 proto, u64 flags) |
| * Description |
| * Change the protocol of the *skb* to *proto*. Currently |
| * supported are transition from IPv4 to IPv6, and from IPv6 to |
| * IPv4. The helper takes care of the groundwork for the |
| * transition, including resizing the socket buffer. The eBPF |
| * program is expected to fill the new headers, if any, via |
| * **skb_store_bytes**\ () and to recompute the checksums with |
| * **bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\ |
| * (). The main case for this helper is to perform NAT64 |
| * operations out of an eBPF program. |
| * |
| * Internally, the GSO type is marked as dodgy so that headers are |
| * checked and segments are recalculated by the GSO/GRO engine. |
| * The size for GSO target is adapted as well. |
| * |
| * All values for *flags* are reserved for future usage, and must |
| * be left at zero. |
| * |
| * A call to this helper is susceptible to change the underlying |
| * packet buffer. Therefore, at load time, all checks on pointers |
| * previously done by the verifier are invalidated and must be |
| * performed again, if the helper is used in combination with |
| * direct packet access. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_skb_change_type(struct sk_buff *skb, u32 type) |
| * Description |
| * Change the packet type for the packet associated to *skb*. This |
| * comes down to setting *skb*\ **->pkt_type** to *type*, except |
| * the eBPF program does not have a write access to *skb*\ |
| * **->pkt_type** beside this helper. Using a helper here allows |
| * for graceful handling of errors. |
| * |
| * The major use case is to change incoming *skb*s to |
| * **PACKET_HOST** in a programmatic way instead of having to |
| * recirculate via **redirect**\ (..., **BPF_F_INGRESS**), for |
| * example. |
| * |
| * Note that *type* only allows certain values. At this time, they |
| * are: |
| * |
| * **PACKET_HOST** |
| * Packet is for us. |
| * **PACKET_BROADCAST** |
| * Send packet to all. |
| * **PACKET_MULTICAST** |
| * Send packet to group. |
| * **PACKET_OTHERHOST** |
| * Send packet to someone else. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_skb_under_cgroup(struct sk_buff *skb, struct bpf_map *map, u32 index) |
| * Description |
| * Check whether *skb* is a descendant of the cgroup2 held by |
| * *map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*. |
| * Return |
| * The return value depends on the result of the test, and can be: |
| * |
| * * 0, if the *skb* failed the cgroup2 descendant test. |
| * * 1, if the *skb* succeeded the cgroup2 descendant test. |
| * * A negative error code, if an error occurred. |
| * |
| * u32 bpf_get_hash_recalc(struct sk_buff *skb) |
| * Description |
| * Retrieve the hash of the packet, *skb*\ **->hash**. If it is |
| * not set, in particular if the hash was cleared due to mangling, |
| * recompute this hash. Later accesses to the hash can be done |
| * directly with *skb*\ **->hash**. |
| * |
| * Calling **bpf_set_hash_invalid**\ (), changing a packet |
| * prototype with **bpf_skb_change_proto**\ (), or calling |
| * **bpf_skb_store_bytes**\ () with the |
| * **BPF_F_INVALIDATE_HASH** are actions susceptible to clear |
| * the hash and to trigger a new computation for the next call to |
| * **bpf_get_hash_recalc**\ (). |
| * Return |
| * The 32-bit hash. |
| * |
| * u64 bpf_get_current_task(void) |
| * Return |
| * A pointer to the current task struct. |
| * |
| * long bpf_probe_write_user(void *dst, const void *src, u32 len) |
| * Description |
| * Attempt in a safe way to write *len* bytes from the buffer |
| * *src* to *dst* in memory. It only works for threads that are in |
| * user context, and *dst* must be a valid user space address. |
| * |
| * This helper should not be used to implement any kind of |
| * security mechanism because of TOC-TOU attacks, but rather to |
| * debug, divert, and manipulate execution of semi-cooperative |
| * processes. |
| * |
| * Keep in mind that this feature is meant for experiments, and it |
| * has a risk of crashing the system and running programs. |
| * Therefore, when an eBPF program using this helper is attached, |
| * a warning including PID and process name is printed to kernel |
| * logs. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_current_task_under_cgroup(struct bpf_map *map, u32 index) |
| * Description |
| * Check whether the probe is being run is the context of a given |
| * subset of the cgroup2 hierarchy. The cgroup2 to test is held by |
| * *map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*. |
| * Return |
| * The return value depends on the result of the test, and can be: |
| * |
| * * 0, if current task belongs to the cgroup2. |
| * * 1, if current task does not belong to the cgroup2. |
| * * A negative error code, if an error occurred. |
| * |
| * long bpf_skb_change_tail(struct sk_buff *skb, u32 len, u64 flags) |
| * Description |
| * Resize (trim or grow) the packet associated to *skb* to the |
| * new *len*. The *flags* are reserved for future usage, and must |
| * be left at zero. |
| * |
| * The basic idea is that the helper performs the needed work to |
| * change the size of the packet, then the eBPF program rewrites |
| * the rest via helpers like **bpf_skb_store_bytes**\ (), |
| * **bpf_l3_csum_replace**\ (), **bpf_l3_csum_replace**\ () |
| * and others. This helper is a slow path utility intended for |
| * replies with control messages. And because it is targeted for |
| * slow path, the helper itself can afford to be slow: it |
| * implicitly linearizes, unclones and drops offloads from the |
| * *skb*. |
| * |
| * A call to this helper is susceptible to change the underlying |
| * packet buffer. Therefore, at load time, all checks on pointers |
| * previously done by the verifier are invalidated and must be |
| * performed again, if the helper is used in combination with |
| * direct packet access. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_skb_pull_data(struct sk_buff *skb, u32 len) |
| * Description |
| * Pull in non-linear data in case the *skb* is non-linear and not |
| * all of *len* are part of the linear section. Make *len* bytes |
| * from *skb* readable and writable. If a zero value is passed for |
| * *len*, then the whole length of the *skb* is pulled. |
| * |
| * This helper is only needed for reading and writing with direct |
| * packet access. |
| * |
| * For direct packet access, testing that offsets to access |
| * are within packet boundaries (test on *skb*\ **->data_end**) is |
| * susceptible to fail if offsets are invalid, or if the requested |
| * data is in non-linear parts of the *skb*. On failure the |
| * program can just bail out, or in the case of a non-linear |
| * buffer, use a helper to make the data available. The |
| * **bpf_skb_load_bytes**\ () helper is a first solution to access |
| * the data. Another one consists in using **bpf_skb_pull_data** |
| * to pull in once the non-linear parts, then retesting and |
| * eventually access the data. |
| * |
| * At the same time, this also makes sure the *skb* is uncloned, |
| * which is a necessary condition for direct write. As this needs |
| * to be an invariant for the write part only, the verifier |
| * detects writes and adds a prologue that is calling |
| * **bpf_skb_pull_data()** to effectively unclone the *skb* from |
| * the very beginning in case it is indeed cloned. |
| * |
| * A call to this helper is susceptible to change the underlying |
| * packet buffer. Therefore, at load time, all checks on pointers |
| * previously done by the verifier are invalidated and must be |
| * performed again, if the helper is used in combination with |
| * direct packet access. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * s64 bpf_csum_update(struct sk_buff *skb, __wsum csum) |
| * Description |
| * Add the checksum *csum* into *skb*\ **->csum** in case the |
| * driver has supplied a checksum for the entire packet into that |
| * field. Return an error otherwise. This helper is intended to be |
| * used in combination with **bpf_csum_diff**\ (), in particular |
| * when the checksum needs to be updated after data has been |
| * written into the packet through direct packet access. |
| * Return |
| * The checksum on success, or a negative error code in case of |
| * failure. |
| * |
| * void bpf_set_hash_invalid(struct sk_buff *skb) |
| * Description |
| * Invalidate the current *skb*\ **->hash**. It can be used after |
| * mangling on headers through direct packet access, in order to |
| * indicate that the hash is outdated and to trigger a |
| * recalculation the next time the kernel tries to access this |
| * hash or when the **bpf_get_hash_recalc**\ () helper is called. |
| * |
| * long bpf_get_numa_node_id(void) |
| * Description |
| * Return the id of the current NUMA node. The primary use case |
| * for this helper is the selection of sockets for the local NUMA |
| * node, when the program is attached to sockets using the |
| * **SO_ATTACH_REUSEPORT_EBPF** option (see also **socket(7)**), |
| * but the helper is also available to other eBPF program types, |
| * similarly to **bpf_get_smp_processor_id**\ (). |
| * Return |
| * The id of current NUMA node. |
| * |
| * long bpf_skb_change_head(struct sk_buff *skb, u32 len, u64 flags) |
| * Description |
| * Grows headroom of packet associated to *skb* and adjusts the |
| * offset of the MAC header accordingly, adding *len* bytes of |
| * space. It automatically extends and reallocates memory as |
| * required. |
| * |
| * This helper can be used on a layer 3 *skb* to push a MAC header |
| * for redirection into a layer 2 device. |
| * |
| * All values for *flags* are reserved for future usage, and must |
| * be left at zero. |
| * |
| * A call to this helper is susceptible to change the underlying |
| * packet buffer. Therefore, at load time, all checks on pointers |
| * previously done by the verifier are invalidated and must be |
| * performed again, if the helper is used in combination with |
| * direct packet access. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_xdp_adjust_head(struct xdp_buff *xdp_md, int delta) |
| * Description |
| * Adjust (move) *xdp_md*\ **->data** by *delta* bytes. Note that |
| * it is possible to use a negative value for *delta*. This helper |
| * can be used to prepare the packet for pushing or popping |
| * headers. |
| * |
| * A call to this helper is susceptible to change the underlying |
| * packet buffer. Therefore, at load time, all checks on pointers |
| * previously done by the verifier are invalidated and must be |
| * performed again, if the helper is used in combination with |
| * direct packet access. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_probe_read_str(void *dst, u32 size, const void *unsafe_ptr) |
| * Description |
| * Copy a NUL terminated string from an unsafe kernel address |
| * *unsafe_ptr* to *dst*. See **bpf_probe_read_kernel_str**\ () for |
| * more details. |
| * |
| * Generally, use **bpf_probe_read_user_str**\ () or |
| * **bpf_probe_read_kernel_str**\ () instead. |
| * Return |
| * On success, the strictly positive length of the string, |
| * including the trailing NUL character. On error, a negative |
| * value. |
| * |
| * u64 bpf_get_socket_cookie(struct sk_buff *skb) |
| * Description |
| * If the **struct sk_buff** pointed by *skb* has a known socket, |
| * retrieve the cookie (generated by the kernel) of this socket. |
| * If no cookie has been set yet, generate a new cookie. Once |
| * generated, the socket cookie remains stable for the life of the |
| * socket. This helper can be useful for monitoring per socket |
| * networking traffic statistics as it provides a global socket |
| * identifier that can be assumed unique. |
| * Return |
| * A 8-byte long unique number on success, or 0 if the socket |
| * field is missing inside *skb*. |
| * |
| * u64 bpf_get_socket_cookie(struct bpf_sock_addr *ctx) |
| * Description |
| * Equivalent to bpf_get_socket_cookie() helper that accepts |
| * *skb*, but gets socket from **struct bpf_sock_addr** context. |
| * Return |
| * A 8-byte long unique number. |
| * |
| * u64 bpf_get_socket_cookie(struct bpf_sock_ops *ctx) |
| * Description |
| * Equivalent to **bpf_get_socket_cookie**\ () helper that accepts |
| * *skb*, but gets socket from **struct bpf_sock_ops** context. |
| * Return |
| * A 8-byte long unique number. |
| * |
| * u64 bpf_get_socket_cookie(struct sock *sk) |
| * Description |
| * Equivalent to **bpf_get_socket_cookie**\ () helper that accepts |
| * *sk*, but gets socket from a BTF **struct sock**. This helper |
| * also works for sleepable programs. |
| * Return |
| * A 8-byte long unique number or 0 if *sk* is NULL. |
| * |
| * u32 bpf_get_socket_uid(struct sk_buff *skb) |
| * Return |
| * The owner UID of the socket associated to *skb*. If the socket |
| * is **NULL**, or if it is not a full socket (i.e. if it is a |
| * time-wait or a request socket instead), **overflowuid** value |
| * is returned (note that **overflowuid** might also be the actual |
| * UID value for the socket). |
| * |
| * long bpf_set_hash(struct sk_buff *skb, u32 hash) |
| * Description |
| * Set the full hash for *skb* (set the field *skb*\ **->hash**) |
| * to value *hash*. |
| * Return |
| * 0 |
| * |
| * long bpf_setsockopt(void *bpf_socket, int level, int optname, void *optval, int optlen) |
| * Description |
| * Emulate a call to **setsockopt()** on the socket associated to |
| * *bpf_socket*, which must be a full socket. The *level* at |
| * which the option resides and the name *optname* of the option |
| * must be specified, see **setsockopt(2)** for more information. |
| * The option value of length *optlen* is pointed by *optval*. |
| * |
| * *bpf_socket* should be one of the following: |
| * |
| * * **struct bpf_sock_ops** for **BPF_PROG_TYPE_SOCK_OPS**. |
| * * **struct bpf_sock_addr** for **BPF_CGROUP_INET4_CONNECT** |
| * and **BPF_CGROUP_INET6_CONNECT**. |
| * |
| * This helper actually implements a subset of **setsockopt()**. |
| * It supports the following *level*\ s: |
| * |
| * * **SOL_SOCKET**, which supports the following *optname*\ s: |
| * **SO_RCVBUF**, **SO_SNDBUF**, **SO_MAX_PACING_RATE**, |
| * **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**, |
| * **SO_BINDTODEVICE**, **SO_KEEPALIVE**. |
| * * **IPPROTO_TCP**, which supports the following *optname*\ s: |
| * **TCP_CONGESTION**, **TCP_BPF_IW**, |
| * **TCP_BPF_SNDCWND_CLAMP**, **TCP_SAVE_SYN**, |
| * **TCP_KEEPIDLE**, **TCP_KEEPINTVL**, **TCP_KEEPCNT**, |
| * **TCP_SYNCNT**, **TCP_USER_TIMEOUT**, **TCP_NOTSENT_LOWAT**. |
| * * **IPPROTO_IP**, which supports *optname* **IP_TOS**. |
| * * **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_skb_adjust_room(struct sk_buff *skb, s32 len_diff, u32 mode, u64 flags) |
| * Description |
| * Grow or shrink the room for data in the packet associated to |
| * *skb* by *len_diff*, and according to the selected *mode*. |
| * |
| * By default, the helper will reset any offloaded checksum |
| * indicator of the skb to CHECKSUM_NONE. This can be avoided |
| * by the following flag: |
| * |
| * * **BPF_F_ADJ_ROOM_NO_CSUM_RESET**: Do not reset offloaded |
| * checksum data of the skb to CHECKSUM_NONE. |
| * |
| * There are two supported modes at this time: |
| * |
| * * **BPF_ADJ_ROOM_MAC**: Adjust room at the mac layer |
| * (room space is added or removed below the layer 2 header). |
| * |
| * * **BPF_ADJ_ROOM_NET**: Adjust room at the network layer |
| * (room space is added or removed below the layer 3 header). |
| * |
| * The following flags are supported at this time: |
| * |
| * * **BPF_F_ADJ_ROOM_FIXED_GSO**: Do not adjust gso_size. |
| * Adjusting mss in this way is not allowed for datagrams. |
| * |
| * * **BPF_F_ADJ_ROOM_ENCAP_L3_IPV4**, |
| * **BPF_F_ADJ_ROOM_ENCAP_L3_IPV6**: |
| * Any new space is reserved to hold a tunnel header. |
| * Configure skb offsets and other fields accordingly. |
| * |
| * * **BPF_F_ADJ_ROOM_ENCAP_L4_GRE**, |
| * **BPF_F_ADJ_ROOM_ENCAP_L4_UDP**: |
| * Use with ENCAP_L3 flags to further specify the tunnel type. |
| * |
| * * **BPF_F_ADJ_ROOM_ENCAP_L2**\ (*len*): |
| * Use with ENCAP_L3/L4 flags to further specify the tunnel |
| * type; *len* is the length of the inner MAC header. |
| * |
| * * **BPF_F_ADJ_ROOM_ENCAP_L2_ETH**: |
| * Use with BPF_F_ADJ_ROOM_ENCAP_L2 flag to further specify the |
| * L2 type as Ethernet. |
| * |
| * A call to this helper is susceptible to change the underlying |
| * packet buffer. Therefore, at load time, all checks on pointers |
| * previously done by the verifier are invalidated and must be |
| * performed again, if the helper is used in combination with |
| * direct packet access. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_redirect_map(struct bpf_map *map, u32 key, u64 flags) |
| * Description |
| * Redirect the packet to the endpoint referenced by *map* at |
| * index *key*. Depending on its type, this *map* can contain |
| * references to net devices (for forwarding packets through other |
| * ports), or to CPUs (for redirecting XDP frames to another CPU; |
| * but this is only implemented for native XDP (with driver |
| * support) as of this writing). |
| * |
| * The lower two bits of *flags* are used as the return code if |
| * the map lookup fails. This is so that the return value can be |
| * one of the XDP program return codes up to **XDP_TX**, as chosen |
| * by the caller. The higher bits of *flags* can be set to |
| * BPF_F_BROADCAST or BPF_F_EXCLUDE_INGRESS as defined below. |
| * |
| * With BPF_F_BROADCAST the packet will be broadcasted to all the |
| * interfaces in the map, with BPF_F_EXCLUDE_INGRESS the ingress |
| * interface will be excluded when do broadcasting. |
| * |
| * See also **bpf_redirect**\ (), which only supports redirecting |
| * to an ifindex, but doesn't require a map to do so. |
| * Return |
| * **XDP_REDIRECT** on success, or the value of the two lower bits |
| * of the *flags* argument on error. |
| * |
| * long bpf_sk_redirect_map(struct sk_buff *skb, struct bpf_map *map, u32 key, u64 flags) |
| * Description |
| * Redirect the packet to the socket referenced by *map* (of type |
| * **BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and |
| * egress interfaces can be used for redirection. The |
| * **BPF_F_INGRESS** value in *flags* is used to make the |
| * distinction (ingress path is selected if the flag is present, |
| * egress path otherwise). This is the only flag supported for now. |
| * Return |
| * **SK_PASS** on success, or **SK_DROP** on error. |
| * |
| * long bpf_sock_map_update(struct bpf_sock_ops *skops, struct bpf_map *map, void *key, u64 flags) |
| * Description |
| * Add an entry to, or update a *map* referencing sockets. The |
| * *skops* is used as a new value for the entry associated to |
| * *key*. *flags* is one of: |
| * |
| * **BPF_NOEXIST** |
| * The entry for *key* must not exist in the map. |
| * **BPF_EXIST** |
| * The entry for *key* must already exist in the map. |
| * **BPF_ANY** |
| * No condition on the existence of the entry for *key*. |
| * |
| * If the *map* has eBPF programs (parser and verdict), those will |
| * be inherited by the socket being added. If the socket is |
| * already attached to eBPF programs, this results in an error. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_xdp_adjust_meta(struct xdp_buff *xdp_md, int delta) |
| * Description |
| * Adjust the address pointed by *xdp_md*\ **->data_meta** by |
| * *delta* (which can be positive or negative). Note that this |
| * operation modifies the address stored in *xdp_md*\ **->data**, |
| * so the latter must be loaded only after the helper has been |
| * called. |
| * |
| * The use of *xdp_md*\ **->data_meta** is optional and programs |
| * are not required to use it. The rationale is that when the |
| * packet is processed with XDP (e.g. as DoS filter), it is |
| * possible to push further meta data along with it before passing |
| * to the stack, and to give the guarantee that an ingress eBPF |
| * program attached as a TC classifier on the same device can pick |
| * this up for further post-processing. Since TC works with socket |
| * buffers, it remains possible to set from XDP the **mark** or |
| * **priority** pointers, or other pointers for the socket buffer. |
| * Having this scratch space generic and programmable allows for |
| * more flexibility as the user is free to store whatever meta |
| * data they need. |
| * |
| * A call to this helper is susceptible to change the underlying |
| * packet buffer. Therefore, at load time, all checks on pointers |
| * previously done by the verifier are invalidated and must be |
| * performed again, if the helper is used in combination with |
| * direct packet access. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_perf_event_read_value(struct bpf_map *map, u64 flags, struct bpf_perf_event_value *buf, u32 buf_size) |
| * Description |
| * Read the value of a perf event counter, and store it into *buf* |
| * of size *buf_size*. This helper relies on a *map* of type |
| * **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of the perf event |
| * counter is selected when *map* is updated with perf event file |
| * descriptors. The *map* is an array whose size is the number of |
| * available CPUs, and each cell contains a value relative to one |
| * CPU. The value to retrieve is indicated by *flags*, that |
| * contains the index of the CPU to look up, masked with |
| * **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to |
| * **BPF_F_CURRENT_CPU** to indicate that the value for the |
| * current CPU should be retrieved. |
| * |
| * This helper behaves in a way close to |
| * **bpf_perf_event_read**\ () helper, save that instead of |
| * just returning the value observed, it fills the *buf* |
| * structure. This allows for additional data to be retrieved: in |
| * particular, the enabled and running times (in *buf*\ |
| * **->enabled** and *buf*\ **->running**, respectively) are |
| * copied. In general, **bpf_perf_event_read_value**\ () is |
| * recommended over **bpf_perf_event_read**\ (), which has some |
| * ABI issues and provides fewer functionalities. |
| * |
| * These values are interesting, because hardware PMU (Performance |
| * Monitoring Unit) counters are limited resources. When there are |
| * more PMU based perf events opened than available counters, |
| * kernel will multiplex these events so each event gets certain |
| * percentage (but not all) of the PMU time. In case that |
| * multiplexing happens, the number of samples or counter value |
| * will not reflect the case compared to when no multiplexing |
| * occurs. This makes comparison between different runs difficult. |
| * Typically, the counter value should be normalized before |
| * comparing to other experiments. The usual normalization is done |
| * as follows. |
| * |
| * :: |
| * |
| * normalized_counter = counter * t_enabled / t_running |
| * |
| * Where t_enabled is the time enabled for event and t_running is |
| * the time running for event since last normalization. The |
| * enabled and running times are accumulated since the perf event |
| * open. To achieve scaling factor between two invocations of an |
| * eBPF program, users can use CPU id as the key (which is |
| * typical for perf array usage model) to remember the previous |
| * value and do the calculation inside the eBPF program. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_perf_prog_read_value(struct bpf_perf_event_data *ctx, struct bpf_perf_event_value *buf, u32 buf_size) |
| * Description |
| * For en eBPF program attached to a perf event, retrieve the |
| * value of the event counter associated to *ctx* and store it in |
| * the structure pointed by *buf* and of size *buf_size*. Enabled |
| * and running times are also stored in the structure (see |
| * description of helper **bpf_perf_event_read_value**\ () for |
| * more details). |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_getsockopt(void *bpf_socket, int level, int optname, void *optval, int optlen) |
| * Description |
| * Emulate a call to **getsockopt()** on the socket associated to |
| * *bpf_socket*, which must be a full socket. The *level* at |
| * which the option resides and the name *optname* of the option |
| * must be specified, see **getsockopt(2)** for more information. |
| * The retrieved value is stored in the structure pointed by |
| * *opval* and of length *optlen*. |
| * |
| * *bpf_socket* should be one of the following: |
| * |
| * * **struct bpf_sock_ops** for **BPF_PROG_TYPE_SOCK_OPS**. |
| * * **struct bpf_sock_addr** for **BPF_CGROUP_INET4_CONNECT** |
| * and **BPF_CGROUP_INET6_CONNECT**. |
| * |
| * This helper actually implements a subset of **getsockopt()**. |
| * It supports the following *level*\ s: |
| * |
| * * **IPPROTO_TCP**, which supports *optname* |
| * **TCP_CONGESTION**. |
| * * **IPPROTO_IP**, which supports *optname* **IP_TOS**. |
| * * **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_override_return(struct pt_regs *regs, u64 rc) |
| * Description |
| * Used for error injection, this helper uses kprobes to override |
| * the return value of the probed function, and to set it to *rc*. |
| * The first argument is the context *regs* on which the kprobe |
| * works. |
| * |
| * This helper works by setting the PC (program counter) |
| * to an override function which is run in place of the original |
| * probed function. This means the probed function is not run at |
| * all. The replacement function just returns with the required |
| * value. |
| * |
| * This helper has security implications, and thus is subject to |
| * restrictions. It is only available if the kernel was compiled |
| * with the **CONFIG_BPF_KPROBE_OVERRIDE** configuration |
| * option, and in this case it only works on functions tagged with |
| * **ALLOW_ERROR_INJECTION** in the kernel code. |
| * |
| * Also, the helper is only available for the architectures having |
| * the CONFIG_FUNCTION_ERROR_INJECTION option. As of this writing, |
| * x86 architecture is the only one to support this feature. |
| * Return |
| * 0 |
| * |
| * long bpf_sock_ops_cb_flags_set(struct bpf_sock_ops *bpf_sock, int argval) |
| * Description |
| * Attempt to set the value of the **bpf_sock_ops_cb_flags** field |
| * for the full TCP socket associated to *bpf_sock_ops* to |
| * *argval*. |
| * |
| * The primary use of this field is to determine if there should |
| * be calls to eBPF programs of type |
| * **BPF_PROG_TYPE_SOCK_OPS** at various points in the TCP |
| * code. A program of the same type can change its value, per |
| * connection and as necessary, when the connection is |
| * established. This field is directly accessible for reading, but |
| * this helper must be used for updates in order to return an |
| * error if an eBPF program tries to set a callback that is not |
| * supported in the current kernel. |
| * |
| * *argval* is a flag array which can combine these flags: |
| * |
| * * **BPF_SOCK_OPS_RTO_CB_FLAG** (retransmission time out) |
| * * **BPF_SOCK_OPS_RETRANS_CB_FLAG** (retransmission) |
| * * **BPF_SOCK_OPS_STATE_CB_FLAG** (TCP state change) |
| * * **BPF_SOCK_OPS_RTT_CB_FLAG** (every RTT) |
| * |
| * Therefore, this function can be used to clear a callback flag by |
| * setting the appropriate bit to zero. e.g. to disable the RTO |
| * callback: |
| * |
| * **bpf_sock_ops_cb_flags_set(bpf_sock,** |
| * **bpf_sock->bpf_sock_ops_cb_flags & ~BPF_SOCK_OPS_RTO_CB_FLAG)** |
| * |
| * Here are some examples of where one could call such eBPF |
| * program: |
| * |
| * * When RTO fires. |
| * * When a packet is retransmitted. |
| * * When the connection terminates. |
| * * When a packet is sent. |
| * * When a packet is received. |
| * Return |
| * Code **-EINVAL** if the socket is not a full TCP socket; |
| * otherwise, a positive number containing the bits that could not |
| * be set is returned (which comes down to 0 if all bits were set |
| * as required). |
| * |
| * long bpf_msg_redirect_map(struct sk_msg_buff *msg, struct bpf_map *map, u32 key, u64 flags) |
| * Description |
| * This helper is used in programs implementing policies at the |
| * socket level. If the message *msg* is allowed to pass (i.e. if |
| * the verdict eBPF program returns **SK_PASS**), redirect it to |
| * the socket referenced by *map* (of type |
| * **BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and |
| * egress interfaces can be used for redirection. The |
| * **BPF_F_INGRESS** value in *flags* is used to make the |
| * distinction (ingress path is selected if the flag is present, |
| * egress path otherwise). This is the only flag supported for now. |
| * Return |
| * **SK_PASS** on success, or **SK_DROP** on error. |
| * |
| * long bpf_msg_apply_bytes(struct sk_msg_buff *msg, u32 bytes) |
| * Description |
| * For socket policies, apply the verdict of the eBPF program to |
| * the next *bytes* (number of bytes) of message *msg*. |
| * |
| * For example, this helper can be used in the following cases: |
| * |
| * * A single **sendmsg**\ () or **sendfile**\ () system call |
| * contains multiple logical messages that the eBPF program is |
| * supposed to read and for which it should apply a verdict. |
| * * An eBPF program only cares to read the first *bytes* of a |
| * *msg*. If the message has a large payload, then setting up |
| * and calling the eBPF program repeatedly for all bytes, even |
| * though the verdict is already known, would create unnecessary |
| * overhead. |
| * |
| * When called from within an eBPF program, the helper sets a |
| * counter internal to the BPF infrastructure, that is used to |
| * apply the last verdict to the next *bytes*. If *bytes* is |
| * smaller than the current data being processed from a |
| * **sendmsg**\ () or **sendfile**\ () system call, the first |
| * *bytes* will be sent and the eBPF program will be re-run with |
| * the pointer for start of data pointing to byte number *bytes* |
| * **+ 1**. If *bytes* is larger than the current data being |
| * processed, then the eBPF verdict will be applied to multiple |
| * **sendmsg**\ () or **sendfile**\ () calls until *bytes* are |
| * consumed. |
| * |
| * Note that if a socket closes with the internal counter holding |
| * a non-zero value, this is not a problem because data is not |
| * being buffered for *bytes* and is sent as it is received. |
| * Return |
| * 0 |
| * |
| * long bpf_msg_cork_bytes(struct sk_msg_buff *msg, u32 bytes) |
| * Description |
| * For socket policies, prevent the execution of the verdict eBPF |
| * program for message *msg* until *bytes* (byte number) have been |
| * accumulated. |
| * |
| * This can be used when one needs a specific number of bytes |
| * before a verdict can be assigned, even if the data spans |
| * multiple **sendmsg**\ () or **sendfile**\ () calls. The extreme |
| * case would be a user calling **sendmsg**\ () repeatedly with |
| * 1-byte long message segments. Obviously, this is bad for |
| * performance, but it is still valid. If the eBPF program needs |
| * *bytes* bytes to validate a header, this helper can be used to |
| * prevent the eBPF program to be called again until *bytes* have |
| * been accumulated. |
| * Return |
| * 0 |
| * |
| * long bpf_msg_pull_data(struct sk_msg_buff *msg, u32 start, u32 end, u64 flags) |
| * Description |
| * For socket policies, pull in non-linear data from user space |
| * for *msg* and set pointers *msg*\ **->data** and *msg*\ |
| * **->data_end** to *start* and *end* bytes offsets into *msg*, |
| * respectively. |
| * |
| * If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a |
| * *msg* it can only parse data that the (**data**, **data_end**) |
| * pointers have already consumed. For **sendmsg**\ () hooks this |
| * is likely the first scatterlist element. But for calls relying |
| * on the **sendpage** handler (e.g. **sendfile**\ ()) this will |
| * be the range (**0**, **0**) because the data is shared with |
| * user space and by default the objective is to avoid allowing |
| * user space to modify data while (or after) eBPF verdict is |
| * being decided. This helper can be used to pull in data and to |
| * set the start and end pointer to given values. Data will be |
| * copied if necessary (i.e. if data was not linear and if start |
| * and end pointers do not point to the same chunk). |
| * |
| * A call to this helper is susceptible to change the underlying |
| * packet buffer. Therefore, at load time, all checks on pointers |
| * previously done by the verifier are invalidated and must be |
| * performed again, if the helper is used in combination with |
| * direct packet access. |
| * |
| * All values for *flags* are reserved for future usage, and must |
| * be left at zero. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_bind(struct bpf_sock_addr *ctx, struct sockaddr *addr, int addr_len) |
| * Description |
| * Bind the socket associated to *ctx* to the address pointed by |
| * *addr*, of length *addr_len*. This allows for making outgoing |
| * connection from the desired IP address, which can be useful for |
| * example when all processes inside a cgroup should use one |
| * single IP address on a host that has multiple IP configured. |
| * |
| * This helper works for IPv4 and IPv6, TCP and UDP sockets. The |
| * domain (*addr*\ **->sa_family**) must be **AF_INET** (or |
| * **AF_INET6**). It's advised to pass zero port (**sin_port** |
| * or **sin6_port**) which triggers IP_BIND_ADDRESS_NO_PORT-like |
| * behavior and lets the kernel efficiently pick up an unused |
| * port as long as 4-tuple is unique. Passing non-zero port might |
| * lead to degraded performance. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_xdp_adjust_tail(struct xdp_buff *xdp_md, int delta) |
| * Description |
| * Adjust (move) *xdp_md*\ **->data_end** by *delta* bytes. It is |
| * possible to both shrink and grow the packet tail. |
| * Shrink done via *delta* being a negative integer. |
| * |
| * A call to this helper is susceptible to change the underlying |
| * packet buffer. Therefore, at load time, all checks on pointers |
| * previously done by the verifier are invalidated and must be |
| * performed again, if the helper is used in combination with |
| * direct packet access. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_skb_get_xfrm_state(struct sk_buff *skb, u32 index, struct bpf_xfrm_state *xfrm_state, u32 size, u64 flags) |
| * Description |
| * Retrieve the XFRM state (IP transform framework, see also |
| * **ip-xfrm(8)**) at *index* in XFRM "security path" for *skb*. |
| * |
| * The retrieved value is stored in the **struct bpf_xfrm_state** |
| * pointed by *xfrm_state* and of length *size*. |
| * |
| * All values for *flags* are reserved for future usage, and must |
| * be left at zero. |
| * |
| * This helper is available only if the kernel was compiled with |
| * **CONFIG_XFRM** configuration option. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_get_stack(void *ctx, void *buf, u32 size, u64 flags) |
| * Description |
| * Return a user or a kernel stack in bpf program provided buffer. |
| * To achieve this, the helper needs *ctx*, which is a pointer |
| * to the context on which the tracing program is executed. |
| * To store the stacktrace, the bpf program provides *buf* with |
| * a nonnegative *size*. |
| * |
| * The last argument, *flags*, holds the number of stack frames to |
| * skip (from 0 to 255), masked with |
| * **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set |
| * the following flags: |
| * |
| * **BPF_F_USER_STACK** |
| * Collect a user space stack instead of a kernel stack. |
| * **BPF_F_USER_BUILD_ID** |
| * Collect buildid+offset instead of ips for user stack, |
| * only valid if **BPF_F_USER_STACK** is also specified. |
| * |
| * **bpf_get_stack**\ () can collect up to |
| * **PERF_MAX_STACK_DEPTH** both kernel and user frames, subject |
| * to sufficient large buffer size. Note that |
| * this limit can be controlled with the **sysctl** program, and |
| * that it should be manually increased in order to profile long |
| * user stacks (such as stacks for Java programs). To do so, use: |
| * |
| * :: |
| * |
| * # sysctl kernel.perf_event_max_stack=<new value> |
| * Return |
| * A non-negative value equal to or less than *size* on success, |
| * or a negative error in case of failure. |
| * |
| * long bpf_skb_load_bytes_relative(const void *skb, u32 offset, void *to, u32 len, u32 start_header) |
| * Description |
| * This helper is similar to **bpf_skb_load_bytes**\ () in that |
| * it provides an easy way to load *len* bytes from *offset* |
| * from the packet associated to *skb*, into the buffer pointed |
| * by *to*. The difference to **bpf_skb_load_bytes**\ () is that |
| * a fifth argument *start_header* exists in order to select a |
| * base offset to start from. *start_header* can be one of: |
| * |
| * **BPF_HDR_START_MAC** |
| * Base offset to load data from is *skb*'s mac header. |
| * **BPF_HDR_START_NET** |
| * Base offset to load data from is *skb*'s network header. |
| * |
| * In general, "direct packet access" is the preferred method to |
| * access packet data, however, this helper is in particular useful |
| * in socket filters where *skb*\ **->data** does not always point |
| * to the start of the mac header and where "direct packet access" |
| * is not available. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_fib_lookup(void *ctx, struct bpf_fib_lookup *params, int plen, u32 flags) |
| * Description |
| * Do FIB lookup in kernel tables using parameters in *params*. |
| * If lookup is successful and result shows packet is to be |
| * forwarded, the neighbor tables are searched for the nexthop. |
| * If successful (ie., FIB lookup shows forwarding and nexthop |
| * is resolved), the nexthop address is returned in ipv4_dst |
| * or ipv6_dst based on family, smac is set to mac address of |
| * egress device, dmac is set to nexthop mac address, rt_metric |
| * is set to metric from route (IPv4/IPv6 only), and ifindex |
| * is set to the device index of the nexthop from the FIB lookup. |
| * |
| * *plen* argument is the size of the passed in struct. |
| * *flags* argument can be a combination of one or more of the |
| * following values: |
| * |
| * **BPF_FIB_LOOKUP_DIRECT** |
| * Do a direct table lookup vs full lookup using FIB |
| * rules. |
| * **BPF_FIB_LOOKUP_OUTPUT** |
| * Perform lookup from an egress perspective (default is |
| * ingress). |
| * |
| * *ctx* is either **struct xdp_md** for XDP programs or |
| * **struct sk_buff** tc cls_act programs. |
| * Return |
| * * < 0 if any input argument is invalid |
| * * 0 on success (packet is forwarded, nexthop neighbor exists) |
| * * > 0 one of **BPF_FIB_LKUP_RET_** codes explaining why the |
| * packet is not forwarded or needs assist from full stack |
| * |
| * If lookup fails with BPF_FIB_LKUP_RET_FRAG_NEEDED, then the MTU |
| * was exceeded and output params->mtu_result contains the MTU. |
| * |
| * long bpf_sock_hash_update(struct bpf_sock_ops *skops, struct bpf_map *map, void *key, u64 flags) |
| * Description |
| * Add an entry to, or update a sockhash *map* referencing sockets. |
| * The *skops* is used as a new value for the entry associated to |
| * *key*. *flags* is one of: |
| * |
| * **BPF_NOEXIST** |
| * The entry for *key* must not exist in the map. |
| * **BPF_EXIST** |
| * The entry for *key* must already exist in the map. |
| * **BPF_ANY** |
| * No condition on the existence of the entry for *key*. |
| * |
| * If the *map* has eBPF programs (parser and verdict), those will |
| * be inherited by the socket being added. If the socket is |
| * already attached to eBPF programs, this results in an error. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_msg_redirect_hash(struct sk_msg_buff *msg, struct bpf_map *map, void *key, u64 flags) |
| * Description |
| * This helper is used in programs implementing policies at the |
| * socket level. If the message *msg* is allowed to pass (i.e. if |
| * the verdict eBPF program returns **SK_PASS**), redirect it to |
| * the socket referenced by *map* (of type |
| * **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and |
| * egress interfaces can be used for redirection. The |
| * **BPF_F_INGRESS** value in *flags* is used to make the |
| * distinction (ingress path is selected if the flag is present, |
| * egress path otherwise). This is the only flag supported for now. |
| * Return |
| * **SK_PASS** on success, or **SK_DROP** on error. |
| * |
| * long bpf_sk_redirect_hash(struct sk_buff *skb, struct bpf_map *map, void *key, u64 flags) |
| * Description |
| * This helper is used in programs implementing policies at the |
| * skb socket level. If the sk_buff *skb* is allowed to pass (i.e. |
| * if the verdict eBPF program returns **SK_PASS**), redirect it |
| * to the socket referenced by *map* (of type |
| * **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and |
| * egress interfaces can be used for redirection. The |
| * **BPF_F_INGRESS** value in *flags* is used to make the |
| * distinction (ingress path is selected if the flag is present, |
| * egress otherwise). This is the only flag supported for now. |
| * Return |
| * **SK_PASS** on success, or **SK_DROP** on error. |
| * |
| * long bpf_lwt_push_encap(struct sk_buff *skb, u32 type, void *hdr, u32 len) |
| * Description |
| * Encapsulate the packet associated to *skb* within a Layer 3 |
| * protocol header. This header is provided in the buffer at |
| * address *hdr*, with *len* its size in bytes. *type* indicates |
| * the protocol of the header and can be one of: |
| * |
| * **BPF_LWT_ENCAP_SEG6** |
| * IPv6 encapsulation with Segment Routing Header |
| * (**struct ipv6_sr_hdr**). *hdr* only contains the SRH, |
| * the IPv6 header is computed by the kernel. |
| * **BPF_LWT_ENCAP_SEG6_INLINE** |
| * Only works if *skb* contains an IPv6 packet. Insert a |
| * Segment Routing Header (**struct ipv6_sr_hdr**) inside |
| * the IPv6 header. |
| * **BPF_LWT_ENCAP_IP** |
| * IP encapsulation (GRE/GUE/IPIP/etc). The outer header |
| * must be IPv4 or IPv6, followed by zero or more |
| * additional headers, up to **LWT_BPF_MAX_HEADROOM** |
| * total bytes in all prepended headers. Please note that |
| * if **skb_is_gso**\ (*skb*) is true, no more than two |
| * headers can be prepended, and the inner header, if |
| * present, should be either GRE or UDP/GUE. |
| * |
| * **BPF_LWT_ENCAP_SEG6**\ \* types can be called by BPF programs |
| * of type **BPF_PROG_TYPE_LWT_IN**; **BPF_LWT_ENCAP_IP** type can |
| * be called by bpf programs of types **BPF_PROG_TYPE_LWT_IN** and |
| * **BPF_PROG_TYPE_LWT_XMIT**. |
| * |
| * A call to this helper is susceptible to change the underlying |
| * packet buffer. Therefore, at load time, all checks on pointers |
| * previously done by the verifier are invalidated and must be |
| * performed again, if the helper is used in combination with |
| * direct packet access. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_lwt_seg6_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len) |
| * Description |
| * Store *len* bytes from address *from* into the packet |
| * associated to *skb*, at *offset*. Only the flags, tag and TLVs |
| * inside the outermost IPv6 Segment Routing Header can be |
| * modified through this helper. |
| * |
| * A call to this helper is susceptible to change the underlying |
| * packet buffer. Therefore, at load time, all checks on pointers |
| * previously done by the verifier are invalidated and must be |
| * performed again, if the helper is used in combination with |
| * direct packet access. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_lwt_seg6_adjust_srh(struct sk_buff *skb, u32 offset, s32 delta) |
| * Description |
| * Adjust the size allocated to TLVs in the outermost IPv6 |
| * Segment Routing Header contained in the packet associated to |
| * *skb*, at position *offset* by *delta* bytes. Only offsets |
| * after the segments are accepted. *delta* can be as well |
| * positive (growing) as negative (shrinking). |
| * |
| * A call to this helper is susceptible to change the underlying |
| * packet buffer. Therefore, at load time, all checks on pointers |
| * previously done by the verifier are invalidated and must be |
| * performed again, if the helper is used in combination with |
| * direct packet access. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_lwt_seg6_action(struct sk_buff *skb, u32 action, void *param, u32 param_len) |
| * Description |
| * Apply an IPv6 Segment Routing action of type *action* to the |
| * packet associated to *skb*. Each action takes a parameter |
| * contained at address *param*, and of length *param_len* bytes. |
| * *action* can be one of: |
| * |
| * **SEG6_LOCAL_ACTION_END_X** |
| * End.X action: Endpoint with Layer-3 cross-connect. |
| * Type of *param*: **struct in6_addr**. |
| * **SEG6_LOCAL_ACTION_END_T** |
| * End.T action: Endpoint with specific IPv6 table lookup. |
| * Type of *param*: **int**. |
| * **SEG6_LOCAL_ACTION_END_B6** |
| * End.B6 action: Endpoint bound to an SRv6 policy. |
| * Type of *param*: **struct ipv6_sr_hdr**. |
| * **SEG6_LOCAL_ACTION_END_B6_ENCAP** |
| * End.B6.Encap action: Endpoint bound to an SRv6 |
| * encapsulation policy. |
| * Type of *param*: **struct ipv6_sr_hdr**. |
| * |
| * A call to this helper is susceptible to change the underlying |
| * packet buffer. Therefore, at load time, all checks on pointers |
| * previously done by the verifier are invalidated and must be |
| * performed again, if the helper is used in combination with |
| * direct packet access. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_rc_repeat(void *ctx) |
| * Description |
| * This helper is used in programs implementing IR decoding, to |
| * report a successfully decoded repeat key message. This delays |
| * the generation of a key up event for previously generated |
| * key down event. |
| * |
| * Some IR protocols like NEC have a special IR message for |
| * repeating last button, for when a button is held down. |
| * |
| * The *ctx* should point to the lirc sample as passed into |
| * the program. |
| * |
| * This helper is only available is the kernel was compiled with |
| * the **CONFIG_BPF_LIRC_MODE2** configuration option set to |
| * "**y**". |
| * Return |
| * 0 |
| * |
| * long bpf_rc_keydown(void *ctx, u32 protocol, u64 scancode, u32 toggle) |
| * Description |
| * This helper is used in programs implementing IR decoding, to |
| * report a successfully decoded key press with *scancode*, |
| * *toggle* value in the given *protocol*. The scancode will be |
| * translated to a keycode using the rc keymap, and reported as |
| * an input key down event. After a period a key up event is |
| * generated. This period can be extended by calling either |
| * **bpf_rc_keydown**\ () again with the same values, or calling |
| * **bpf_rc_repeat**\ (). |
| * |
| * Some protocols include a toggle bit, in case the button was |
| * released and pressed again between consecutive scancodes. |
| * |
| * The *ctx* should point to the lirc sample as passed into |
| * the program. |
| * |
| * The *protocol* is the decoded protocol number (see |
| * **enum rc_proto** for some predefined values). |
| * |
| * This helper is only available is the kernel was compiled with |
| * the **CONFIG_BPF_LIRC_MODE2** configuration option set to |
| * "**y**". |
| * Return |
| * 0 |
| * |
| * u64 bpf_skb_cgroup_id(struct sk_buff *skb) |
| * Description |
| * Return the cgroup v2 id of the socket associated with the *skb*. |
| * This is roughly similar to the **bpf_get_cgroup_classid**\ () |
| * helper for cgroup v1 by providing a tag resp. identifier that |
| * can be matched on or used for map lookups e.g. to implement |
| * policy. The cgroup v2 id of a given path in the hierarchy is |
| * exposed in user space through the f_handle API in order to get |
| * to the same 64-bit id. |
| * |
| * This helper can be used on TC egress path, but not on ingress, |
| * and is available only if the kernel was compiled with the |
| * **CONFIG_SOCK_CGROUP_DATA** configuration option. |
| * Return |
| * The id is returned or 0 in case the id could not be retrieved. |
| * |
| * u64 bpf_get_current_cgroup_id(void) |
| * Return |
| * A 64-bit integer containing the current cgroup id based |
| * on the cgroup within which the current task is running. |
| * |
| * void *bpf_get_local_storage(void *map, u64 flags) |
| * Description |
| * Get the pointer to the local storage area. |
| * The type and the size of the local storage is defined |
| * by the *map* argument. |
| * The *flags* meaning is specific for each map type, |
| * and has to be 0 for cgroup local storage. |
| * |
| * Depending on the BPF program type, a local storage area |
| * can be shared between multiple instances of the BPF program, |
| * running simultaneously. |
| * |
| * A user should care about the synchronization by himself. |
| * For example, by using the **BPF_ATOMIC** instructions to alter |
| * the shared data. |
| * Return |
| * A pointer to the local storage area. |
| * |
| * long bpf_sk_select_reuseport(struct sk_reuseport_md *reuse, struct bpf_map *map, void *key, u64 flags) |
| * Description |
| * Select a **SO_REUSEPORT** socket from a |
| * **BPF_MAP_TYPE_REUSEPORT_ARRAY** *map*. |
| * It checks the selected socket is matching the incoming |
| * request in the socket buffer. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * u64 bpf_skb_ancestor_cgroup_id(struct sk_buff *skb, int ancestor_level) |
| * Description |
| * Return id of cgroup v2 that is ancestor of cgroup associated |
| * with the *skb* at the *ancestor_level*. The root cgroup is at |
| * *ancestor_level* zero and each step down the hierarchy |
| * increments the level. If *ancestor_level* == level of cgroup |
| * associated with *skb*, then return value will be same as that |
| * of **bpf_skb_cgroup_id**\ (). |
| * |
| * The helper is useful to implement policies based on cgroups |
| * that are upper in hierarchy than immediate cgroup associated |
| * with *skb*. |
| * |
| * The format of returned id and helper limitations are same as in |
| * **bpf_skb_cgroup_id**\ (). |
| * Return |
| * The id is returned or 0 in case the id could not be retrieved. |
| * |
| * struct bpf_sock *bpf_sk_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags) |
| * Description |
| * Look for TCP socket matching *tuple*, optionally in a child |
| * network namespace *netns*. The return value must be checked, |
| * and if non-**NULL**, released via **bpf_sk_release**\ (). |
| * |
| * The *ctx* should point to the context of the program, such as |
| * the skb or socket (depending on the hook in use). This is used |
| * to determine the base network namespace for the lookup. |
| * |
| * *tuple_size* must be one of: |
| * |
| * **sizeof**\ (*tuple*\ **->ipv4**) |
| * Look for an IPv4 socket. |
| * **sizeof**\ (*tuple*\ **->ipv6**) |
| * Look for an IPv6 socket. |
| * |
| * If the *netns* is a negative signed 32-bit integer, then the |
| * socket lookup table in the netns associated with the *ctx* |
| * will be used. For the TC hooks, this is the netns of the device |
| * in the skb. For socket hooks, this is the netns of the socket. |
| * If *netns* is any other signed 32-bit value greater than or |
| * equal to zero then it specifies the ID of the netns relative to |
| * the netns associated with the *ctx*. *netns* values beyond the |
| * range of 32-bit integers are reserved for future use. |
| * |
| * All values for *flags* are reserved for future usage, and must |
| * be left at zero. |
| * |
| * This helper is available only if the kernel was compiled with |
| * **CONFIG_NET** configuration option. |
| * Return |
| * Pointer to **struct bpf_sock**, or **NULL** in case of failure. |
| * For sockets with reuseport option, the **struct bpf_sock** |
| * result is from *reuse*\ **->socks**\ [] using the hash of the |
| * tuple. |
| * |
| * struct bpf_sock *bpf_sk_lookup_udp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags) |
| * Description |
| * Look for UDP socket matching *tuple*, optionally in a child |
| * network namespace *netns*. The return value must be checked, |
| * and if non-**NULL**, released via **bpf_sk_release**\ (). |
| * |
| * The *ctx* should point to the context of the program, such as |
| * the skb or socket (depending on the hook in use). This is used |
| * to determine the base network namespace for the lookup. |
| * |
| * *tuple_size* must be one of: |
| * |
| * **sizeof**\ (*tuple*\ **->ipv4**) |
| * Look for an IPv4 socket. |
| * **sizeof**\ (*tuple*\ **->ipv6**) |
| * Look for an IPv6 socket. |
| * |
| * If the *netns* is a negative signed 32-bit integer, then the |
| * socket lookup table in the netns associated with the *ctx* |
| * will be used. For the TC hooks, this is the netns of the device |
| * in the skb. For socket hooks, this is the netns of the socket. |
| * If *netns* is any other signed 32-bit value greater than or |
| * equal to zero then it specifies the ID of the netns relative to |
| * the netns associated with the *ctx*. *netns* values beyond the |
| * range of 32-bit integers are reserved for future use. |
| * |
| * All values for *flags* are reserved for future usage, and must |
| * be left at zero. |
| * |
| * This helper is available only if the kernel was compiled with |
| * **CONFIG_NET** configuration option. |
| * Return |
| * Pointer to **struct bpf_sock**, or **NULL** in case of failure. |
| * For sockets with reuseport option, the **struct bpf_sock** |
| * result is from *reuse*\ **->socks**\ [] using the hash of the |
| * tuple. |
| * |
| * long bpf_sk_release(void *sock) |
| * Description |
| * Release the reference held by *sock*. *sock* must be a |
| * non-**NULL** pointer that was returned from |
| * **bpf_sk_lookup_xxx**\ (). |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_map_push_elem(struct bpf_map *map, const void *value, u64 flags) |
| * Description |
| * Push an element *value* in *map*. *flags* is one of: |
| * |
| * **BPF_EXIST** |
| * If the queue/stack is full, the oldest element is |
| * removed to make room for this. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_map_pop_elem(struct bpf_map *map, void *value) |
| * Description |
| * Pop an element from *map*. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_map_peek_elem(struct bpf_map *map, void *value) |
| * Description |
| * Get an element from *map* without removing it. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_msg_push_data(struct sk_msg_buff *msg, u32 start, u32 len, u64 flags) |
| * Description |
| * For socket policies, insert *len* bytes into *msg* at offset |
| * *start*. |
| * |
| * If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a |
| * *msg* it may want to insert metadata or options into the *msg*. |
| * This can later be read and used by any of the lower layer BPF |
| * hooks. |
| * |
| * This helper may fail if under memory pressure (a malloc |
| * fails) in these cases BPF programs will get an appropriate |
| * error and BPF programs will need to handle them. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_msg_pop_data(struct sk_msg_buff *msg, u32 start, u32 len, u64 flags) |
| * Description |
| * Will remove *len* bytes from a *msg* starting at byte *start*. |
| * This may result in **ENOMEM** errors under certain situations if |
| * an allocation and copy are required due to a full ring buffer. |
| * However, the helper will try to avoid doing the allocation |
| * if possible. Other errors can occur if input parameters are |
| * invalid either due to *start* byte not being valid part of *msg* |
| * payload and/or *pop* value being to large. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_rc_pointer_rel(void *ctx, s32 rel_x, s32 rel_y) |
| * Description |
| * This helper is used in programs implementing IR decoding, to |
| * report a successfully decoded pointer movement. |
| * |
| * The *ctx* should point to the lirc sample as passed into |
| * the program. |
| * |
| * This helper is only available is the kernel was compiled with |
| * the **CONFIG_BPF_LIRC_MODE2** configuration option set to |
| * "**y**". |
| * Return |
| * 0 |
| * |
| * long bpf_spin_lock(struct bpf_spin_lock *lock) |
| * Description |
| * Acquire a spinlock represented by the pointer *lock*, which is |
| * stored as part of a value of a map. Taking the lock allows to |
| * safely update the rest of the fields in that value. The |
| * spinlock can (and must) later be released with a call to |
| * **bpf_spin_unlock**\ (\ *lock*\ ). |
| * |
| * Spinlocks in BPF programs come with a number of restrictions |
| * and constraints: |
| * |
| * * **bpf_spin_lock** objects are only allowed inside maps of |
| * types **BPF_MAP_TYPE_HASH** and **BPF_MAP_TYPE_ARRAY** (this |
| * list could be extended in the future). |
| * * BTF description of the map is mandatory. |
| * * The BPF program can take ONE lock at a time, since taking two |
| * or more could cause dead locks. |
| * * Only one **struct bpf_spin_lock** is allowed per map element. |
| * * When the lock is taken, calls (either BPF to BPF or helpers) |
| * are not allowed. |
| * * The **BPF_LD_ABS** and **BPF_LD_IND** instructions are not |
| * allowed inside a spinlock-ed region. |
| * * The BPF program MUST call **bpf_spin_unlock**\ () to release |
| * the lock, on all execution paths, before it returns. |
| * * The BPF program can access **struct bpf_spin_lock** only via |
| * the **bpf_spin_lock**\ () and **bpf_spin_unlock**\ () |
| * helpers. Loading or storing data into the **struct |
| * bpf_spin_lock** *lock*\ **;** field of a map is not allowed. |
| * * To use the **bpf_spin_lock**\ () helper, the BTF description |
| * of the map value must be a struct and have **struct |
| * bpf_spin_lock** *anyname*\ **;** field at the top level. |
| * Nested lock inside another struct is not allowed. |
| * * The **struct bpf_spin_lock** *lock* field in a map value must |
| * be aligned on a multiple of 4 bytes in that value. |
| * * Syscall with command **BPF_MAP_LOOKUP_ELEM** does not copy |
| * the **bpf_spin_lock** field to user space. |
| * * Syscall with command **BPF_MAP_UPDATE_ELEM**, or update from |
| * a BPF program, do not update the **bpf_spin_lock** field. |
| * * **bpf_spin_lock** cannot be on the stack or inside a |
| * networking packet (it can only be inside of a map values). |
| * * **bpf_spin_lock** is available to root only. |
| * * Tracing programs and socket filter programs cannot use |
| * **bpf_spin_lock**\ () due to insufficient preemption checks |
| * (but this may change in the future). |
| * * **bpf_spin_lock** is not allowed in inner maps of map-in-map. |
| * Return |
| * 0 |
| * |
| * long bpf_spin_unlock(struct bpf_spin_lock *lock) |
| * Description |
| * Release the *lock* previously locked by a call to |
| * **bpf_spin_lock**\ (\ *lock*\ ). |
| * Return |
| * 0 |
| * |
| * struct bpf_sock *bpf_sk_fullsock(struct bpf_sock *sk) |
| * Description |
| * This helper gets a **struct bpf_sock** pointer such |
| * that all the fields in this **bpf_sock** can be accessed. |
| * Return |
| * A **struct bpf_sock** pointer on success, or **NULL** in |
| * case of failure. |
| * |
| * struct bpf_tcp_sock *bpf_tcp_sock(struct bpf_sock *sk) |
| * Description |
| * This helper gets a **struct bpf_tcp_sock** pointer from a |
| * **struct bpf_sock** pointer. |
| * Return |
| * A **struct bpf_tcp_sock** pointer on success, or **NULL** in |
| * case of failure. |
| * |
| * long bpf_skb_ecn_set_ce(struct sk_buff *skb) |
| * Description |
| * Set ECN (Explicit Congestion Notification) field of IP header |
| * to **CE** (Congestion Encountered) if current value is **ECT** |
| * (ECN Capable Transport). Otherwise, do nothing. Works with IPv6 |
| * and IPv4. |
| * Return |
| * 1 if the **CE** flag is set (either by the current helper call |
| * or because it was already present), 0 if it is not set. |
| * |
| * struct bpf_sock *bpf_get_listener_sock(struct bpf_sock *sk) |
| * Description |
| * Return a **struct bpf_sock** pointer in **TCP_LISTEN** state. |
| * **bpf_sk_release**\ () is unnecessary and not allowed. |
| * Return |
| * A **struct bpf_sock** pointer on success, or **NULL** in |
| * case of failure. |
| * |
| * struct bpf_sock *bpf_skc_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags) |
| * Description |
| * Look for TCP socket matching *tuple*, optionally in a child |
| * network namespace *netns*. The return value must be checked, |
| * and if non-**NULL**, released via **bpf_sk_release**\ (). |
| * |
| * This function is identical to **bpf_sk_lookup_tcp**\ (), except |
| * that it also returns timewait or request sockets. Use |
| * **bpf_sk_fullsock**\ () or **bpf_tcp_sock**\ () to access the |
| * full structure. |
| * |
| * This helper is available only if the kernel was compiled with |
| * **CONFIG_NET** configuration option. |
| * Return |
| * Pointer to **struct bpf_sock**, or **NULL** in case of failure. |
| * For sockets with reuseport option, the **struct bpf_sock** |
| * result is from *reuse*\ **->socks**\ [] using the hash of the |
| * tuple. |
| * |
| * long bpf_tcp_check_syncookie(void *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len) |
| * Description |
| * Check whether *iph* and *th* contain a valid SYN cookie ACK for |
| * the listening socket in *sk*. |
| * |
| * *iph* points to the start of the IPv4 or IPv6 header, while |
| * *iph_len* contains **sizeof**\ (**struct iphdr**) or |
| * **sizeof**\ (**struct ip6hdr**). |
| * |
| * *th* points to the start of the TCP header, while *th_len* |
| * contains **sizeof**\ (**struct tcphdr**). |
| * Return |
| * 0 if *iph* and *th* are a valid SYN cookie ACK, or a negative |
| * error otherwise. |
| * |
| * long bpf_sysctl_get_name(struct bpf_sysctl *ctx, char *buf, size_t buf_len, u64 flags) |
| * Description |
| * Get name of sysctl in /proc/sys/ and copy it into provided by |
| * program buffer *buf* of size *buf_len*. |
| * |
| * The buffer is always NUL terminated, unless it's zero-sized. |
| * |
| * If *flags* is zero, full name (e.g. "net/ipv4/tcp_mem") is |
| * copied. Use **BPF_F_SYSCTL_BASE_NAME** flag to copy base name |
| * only (e.g. "tcp_mem"). |
| * Return |
| * Number of character copied (not including the trailing NUL). |
| * |
| * **-E2BIG** if the buffer wasn't big enough (*buf* will contain |
| * truncated name in this case). |
| * |
| * long bpf_sysctl_get_current_value(struct bpf_sysctl *ctx, char *buf, size_t buf_len) |
| * Description |
| * Get current value of sysctl as it is presented in /proc/sys |
| * (incl. newline, etc), and copy it as a string into provided |
| * by program buffer *buf* of size *buf_len*. |
| * |
| * The whole value is copied, no matter what file position user |
| * space issued e.g. sys_read at. |
| * |
| * The buffer is always NUL terminated, unless it's zero-sized. |
| * Return |
| * Number of character copied (not including the trailing NUL). |
| * |
| * **-E2BIG** if the buffer wasn't big enough (*buf* will contain |
| * truncated name in this case). |
| * |
| * **-EINVAL** if current value was unavailable, e.g. because |
| * sysctl is uninitialized and read returns -EIO for it. |
| * |
| * long bpf_sysctl_get_new_value(struct bpf_sysctl *ctx, char *buf, size_t buf_len) |
| * Description |
| * Get new value being written by user space to sysctl (before |
| * the actual write happens) and copy it as a string into |
| * provided by program buffer *buf* of size *buf_len*. |
| * |
| * User space may write new value at file position > 0. |
| * |
| * The buffer is always NUL terminated, unless it's zero-sized. |
| * Return |
| * Number of character copied (not including the trailing NUL). |
| * |
| * **-E2BIG** if the buffer wasn't big enough (*buf* will contain |
| * truncated name in this case). |
| * |
| * **-EINVAL** if sysctl is being read. |
| * |
| * long bpf_sysctl_set_new_value(struct bpf_sysctl *ctx, const char *buf, size_t buf_len) |
| * Description |
| * Override new value being written by user space to sysctl with |
| * value provided by program in buffer *buf* of size *buf_len*. |
| * |
| * *buf* should contain a string in same form as provided by user |
| * space on sysctl write. |
| * |
| * User space may write new value at file position > 0. To override |
| * the whole sysctl value file position should be set to zero. |
| * Return |
| * 0 on success. |
| * |
| * **-E2BIG** if the *buf_len* is too big. |
| * |
| * **-EINVAL** if sysctl is being read. |
| * |
| * long bpf_strtol(const char *buf, size_t buf_len, u64 flags, long *res) |
| * Description |
| * Convert the initial part of the string from buffer *buf* of |
| * size *buf_len* to a long integer according to the given base |
| * and save the result in *res*. |
| * |
| * The string may begin with an arbitrary amount of white space |
| * (as determined by **isspace**\ (3)) followed by a single |
| * optional '**-**' sign. |
| * |
| * Five least significant bits of *flags* encode base, other bits |
| * are currently unused. |
| * |
| * Base must be either 8, 10, 16 or 0 to detect it automatically |
| * similar to user space **strtol**\ (3). |
| * Return |
| * Number of characters consumed on success. Must be positive but |
| * no more than *buf_len*. |
| * |
| * **-EINVAL** if no valid digits were found or unsupported base |
| * was provided. |
| * |
| * **-ERANGE** if resulting value was out of range. |
| * |
| * long bpf_strtoul(const char *buf, size_t buf_len, u64 flags, unsigned long *res) |
| * Description |
| * Convert the initial part of the string from buffer *buf* of |
| * size *buf_len* to an unsigned long integer according to the |
| * given base and save the result in *res*. |
| * |
| * The string may begin with an arbitrary amount of white space |
| * (as determined by **isspace**\ (3)). |
| * |
| * Five least significant bits of *flags* encode base, other bits |
| * are currently unused. |
| * |
| * Base must be either 8, 10, 16 or 0 to detect it automatically |
| * similar to user space **strtoul**\ (3). |
| * Return |
| * Number of characters consumed on success. Must be positive but |
| * no more than *buf_len*. |
| * |
| * **-EINVAL** if no valid digits were found or unsupported base |
| * was provided. |
| * |
| * **-ERANGE** if resulting value was out of range. |
| * |
| * void *bpf_sk_storage_get(struct bpf_map *map, void *sk, void *value, u64 flags) |
| * Description |
| * Get a bpf-local-storage from a *sk*. |
| * |
| * Logically, it could be thought of getting the value from |
| * a *map* with *sk* as the **key**. From this |
| * perspective, the usage is not much different from |
| * **bpf_map_lookup_elem**\ (*map*, **&**\ *sk*) except this |
| * helper enforces the key must be a full socket and the map must |
| * be a **BPF_MAP_TYPE_SK_STORAGE** also. |
| * |
| * Underneath, the value is stored locally at *sk* instead of |
| * the *map*. The *map* is used as the bpf-local-storage |
| * "type". The bpf-local-storage "type" (i.e. the *map*) is |
| * searched against all bpf-local-storages residing at *sk*. |
| * |
| * *sk* is a kernel **struct sock** pointer for LSM program. |
| * *sk* is a **struct bpf_sock** pointer for other program types. |
| * |
| * An optional *flags* (**BPF_SK_STORAGE_GET_F_CREATE**) can be |
| * used such that a new bpf-local-storage will be |
| * created if one does not exist. *value* can be used |
| * together with **BPF_SK_STORAGE_GET_F_CREATE** to specify |
| * the initial value of a bpf-local-storage. If *value* is |
| * **NULL**, the new bpf-local-storage will be zero initialized. |
| * Return |
| * A bpf-local-storage pointer is returned on success. |
| * |
| * **NULL** if not found or there was an error in adding |
| * a new bpf-local-storage. |
| * |
| * long bpf_sk_storage_delete(struct bpf_map *map, void *sk) |
| * Description |
| * Delete a bpf-local-storage from a *sk*. |
| * Return |
| * 0 on success. |
| * |
| * **-ENOENT** if the bpf-local-storage cannot be found. |
| * **-EINVAL** if sk is not a fullsock (e.g. a request_sock). |
| * |
| * long bpf_send_signal(u32 sig) |
| * Description |
| * Send signal *sig* to the process of the current task. |
| * The signal may be delivered to any of this process's threads. |
| * Return |
| * 0 on success or successfully queued. |
| * |
| * **-EBUSY** if work queue under nmi is full. |
| * |
| * **-EINVAL** if *sig* is invalid. |
| * |
| * **-EPERM** if no permission to send the *sig*. |
| * |
| * **-EAGAIN** if bpf program can try again. |
| * |
| * s64 bpf_tcp_gen_syncookie(void *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len) |
| * Description |
| * Try to issue a SYN cookie for the packet with corresponding |
| * IP/TCP headers, *iph* and *th*, on the listening socket in *sk*. |
| * |
| * *iph* points to the start of the IPv4 or IPv6 header, while |
| * *iph_len* contains **sizeof**\ (**struct iphdr**) or |
| * **sizeof**\ (**struct ip6hdr**). |
| * |
| * *th* points to the start of the TCP header, while *th_len* |
| * contains the length of the TCP header. |
| * Return |
| * On success, lower 32 bits hold the generated SYN cookie in |
| * followed by 16 bits which hold the MSS value for that cookie, |
| * and the top 16 bits are unused. |
| * |
| * On failure, the returned value is one of the following: |
| * |
| * **-EINVAL** SYN cookie cannot be issued due to error |
| * |
| * **-ENOENT** SYN cookie should not be issued (no SYN flood) |
| * |
| * **-EOPNOTSUPP** kernel configuration does not enable SYN cookies |
| * |
| * **-EPROTONOSUPPORT** IP packet version is not 4 or 6 |
| * |
| * long bpf_skb_output(void *ctx, struct bpf_map *map, u64 flags, void *data, u64 size) |
| * Description |
| * Write raw *data* blob into a special BPF perf event held by |
| * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf |
| * event must have the following attributes: **PERF_SAMPLE_RAW** |
| * as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and |
| * **PERF_COUNT_SW_BPF_OUTPUT** as **config**. |
| * |
| * The *flags* are used to indicate the index in *map* for which |
| * the value must be put, masked with **BPF_F_INDEX_MASK**. |
| * Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU** |
| * to indicate that the index of the current CPU core should be |
| * used. |
| * |
| * The value to write, of *size*, is passed through eBPF stack and |
| * pointed by *data*. |
| * |
| * *ctx* is a pointer to in-kernel struct sk_buff. |
| * |
| * This helper is similar to **bpf_perf_event_output**\ () but |
| * restricted to raw_tracepoint bpf programs. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_probe_read_user(void *dst, u32 size, const void *unsafe_ptr) |
| * Description |
| * Safely attempt to read *size* bytes from user space address |
| * *unsafe_ptr* and store the data in *dst*. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr) |
| * Description |
| * Safely attempt to read *size* bytes from kernel space address |
| * *unsafe_ptr* and store the data in *dst*. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_probe_read_user_str(void *dst, u32 size, const void *unsafe_ptr) |
| * Description |
| * Copy a NUL terminated string from an unsafe user address |
| * *unsafe_ptr* to *dst*. The *size* should include the |
| * terminating NUL byte. In case the string length is smaller than |
| * *size*, the target is not padded with further NUL bytes. If the |
| * string length is larger than *size*, just *size*-1 bytes are |
| * copied and the last byte is set to NUL. |
| * |
| * On success, returns the number of bytes that were written, |
| * including the terminal NUL. This makes this helper useful in |
| * tracing programs for reading strings, and more importantly to |
| * get its length at runtime. See the following snippet: |
| * |
| * :: |
| * |
| * SEC("kprobe/sys_open") |
| * void bpf_sys_open(struct pt_regs *ctx) |
| * { |
| * char buf[PATHLEN]; // PATHLEN is defined to 256 |
| * int res = bpf_probe_read_user_str(buf, sizeof(buf), |
| * ctx->di); |
| * |
| * // Consume buf, for example push it to |
| * // userspace via bpf_perf_event_output(); we |
| * // can use res (the string length) as event |
| * // size, after checking its boundaries. |
| * } |
| * |
| * In comparison, using **bpf_probe_read_user**\ () helper here |
| * instead to read the string would require to estimate the length |
| * at compile time, and would often result in copying more memory |
| * than necessary. |
| * |
| * Another useful use case is when parsing individual process |
| * arguments or individual environment variables navigating |
| * *current*\ **->mm->arg_start** and *current*\ |
| * **->mm->env_start**: using this helper and the return value, |
| * one can quickly iterate at the right offset of the memory area. |
| * Return |
| * On success, the strictly positive length of the output string, |
| * including the trailing NUL character. On error, a negative |
| * value. |
| * |
| * long bpf_probe_read_kernel_str(void *dst, u32 size, const void *unsafe_ptr) |
| * Description |
| * Copy a NUL terminated string from an unsafe kernel address *unsafe_ptr* |
| * to *dst*. Same semantics as with **bpf_probe_read_user_str**\ () apply. |
| * Return |
| * On success, the strictly positive length of the string, including |
| * the trailing NUL character. On error, a negative value. |
| * |
| * long bpf_tcp_send_ack(void *tp, u32 rcv_nxt) |
| * Description |
| * Send out a tcp-ack. *tp* is the in-kernel struct **tcp_sock**. |
| * *rcv_nxt* is the ack_seq to be sent out. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * long bpf_send_signal_thread(u32 sig) |
| * Description |
| * Send signal *sig* to the thread corresponding to the current task. |
| * Return |
| * 0 on success or successfully queued. |
| * |
| * **-EBUSY** if work queue under nmi is full. |
| * |
| * **-EINVAL** if *sig* is invalid. |
| * |
| * **-EPERM** if no permission to send the *sig*. |
| * |
| * **-EAGAIN** if bpf program can try again. |
| * |
| * u64 bpf_jiffies64(void) |
| * Description |
| * Obtain the 64bit jiffies |
| * Return |
| * The 64 bit jiffies |
| * |
| * long bpf_read_branch_records(struct bpf_perf_event_data *ctx, void *buf, u32 size, u64 flags) |
| * Description |
| * For an eBPF program attached to a perf event, retrieve the |
| * branch records (**struct perf_branch_entry**) associated to *ctx* |
| * and store it in the buffer pointed by *buf* up to size |
| * *size* bytes. |
| * Return |
| * On success, number of bytes written to *buf*. On error, a |
| * negative value. |
| * |
| * The *flags* can be set to **BPF_F_GET_BRANCH_RECORDS_SIZE** to |
| * instead return the number of bytes required to store all the |
| * branch entries. If this flag is set, *buf* may be NULL. |
| * |
| * **-EINVAL** if arguments invalid or **size** not a multiple |
| * of **sizeof**\ (**struct perf_branch_entry**\ ). |
| * |
| * **-ENOENT** if architecture does not support branch records. |
| * |
| * long bpf_get_ns_current_pid_tgid(u64 dev, u64 ino, struct bpf_pidns_info *nsdata, u32 size) |
| * Description |
| * Returns 0 on success, values for *pid* and *tgid* as seen from the current |
| * *namespace* will be returned in *nsdata*. |
| * Return |
| * 0 on success, or one of the following in case of failure: |
| * |
| * **-EINVAL** if dev and inum supplied don't match dev_t and inode number |
| * with nsfs of current task, or if dev conversion to dev_t lost high bits. |
| * |
| * **-ENOENT** if pidns does not exists for the current task. |
| * |
| * long bpf_xdp_output(void *ctx, struct bpf_map *map, u64 flags, void *data, u64 size) |
| * Description |
| * Write raw *data* blob into a special BPF perf event held by |
| * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf |
| * event must have the following attributes: **PERF_SAMPLE_RAW** |
| * as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and |
| * **PERF_COUNT_SW_BPF_OUTPUT** as **config**. |
| * |
| * The *flags* are used to indicate the index in *map* for which |
| * the value must be put, masked with **BPF_F_INDEX_MASK**. |
| * Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU** |
| * to indicate that the index of the current CPU core should be |
| * used. |
| * |
| * The value to write, of *size*, is passed through eBPF stack and |
| * pointed by *data*. |
| * |
| * *ctx* is a pointer to in-kernel struct xdp_buff. |
| * |
| * This helper is similar to **bpf_perf_eventoutput**\ () but |
| * restricted to raw_tracepoint bpf programs. |
| * Return |
| * 0 on success, or a negative error in case of failure. |
| * |
| * u64 bpf_get_netns_cookie(void *ctx) |
| * Description |
| * Retrieve the cookie (generated by the kernel) of the network |
| * namespace the input *ctx* is associated with. The network |
| * namespace cookie remains stable for its lifetime and provides |
| * a global identifier that can be assumed unique. If *ctx* is |
| * NULL, then the helper returns the cookie for the initial |
| * network namespace. The cookie itself is very similar to that |
| * of **bpf_get_socket_cookie**\ () helper, but for network |
| * namespaces instead of sockets. |
| * Return |
| * A 8-byte long opaque number. |
| * |
| * u64 bpf_get_current_ancestor_cgroup_id(int ancestor_level) |
| * Description |
| * Return id of cgroup v2 that is ancestor of the cgroup associated |
| * with the current task at the *ancestor_level*. The root cgroup |
| * is at *ancestor_level* zero and each step down the hierarchy |
| * increments the level. If *ancestor_level* == level of cgroup |
| * associated with the current task, then return value will be the |
| * same as that of **bpf_get_current_cgroup_id**\ (). |
| * |
| * The helper is useful to implement policies based on cgroups |
| * that are upper in hierarchy than immediate cgroup associated |
| * with the current task. |
| * |
| * The format of returned id and helper limitations are same as in |
| * **bpf_get_current_cgroup_id**\ (). |
| * Return |
| * The id is returned or 0 in case the id could not be retrieved. |
| * |
| * long bpf_sk_assign(struct sk_buff *skb, void *sk, u64 flags) |
| * Description |
| * Helper is overloaded depending on BPF program type. This |
| * description applies to **BPF_PROG_TYPE_SCHED_CLS** and |
| * **BPF_PROG_TYPE_SCHED_ACT** programs. |
| * |
| * Assign the *sk* to the *skb*. When combined with appropriate |
| * routing configuration to receive the packet towards the socket, |
| * will cause *skb* to be delivered to the specified socket. |
| * Subsequent redirection of *skb* via **bpf_redirect**\ (), |
| * **bpf_clone_redirect**\ () or other methods outside of BPF may |
| * interfere with successful delivery to the socket. |
| * |
| * This operation is only valid from TC ingress path. |
| * |
| * The *flags* argument must be zero. |
| * Return |
| * 0 on success, or a negative error in case of failure: |
| * |
| * **-EINVAL** if specified *flags* are not supported. |
| * |
| * **-ENOENT** if the socket is unavailable for assignment. |
| * |
| * **-ENETUNREACH** if the socket is unreachable (wrong netns). |
| * |
| * **-EOPNOTSUPP** if the operation is not supported, for example |
| * a call from outside of TC ingress. |
| * |
| * **-ESOCKTNOSUPPORT** if the socket type is not supported |
| * (reuseport). |
| * |
| * long bpf_sk_assign(struct bpf_sk_lookup *ctx, struct bpf_sock *sk, u64 flags) |
| * Description |
| * Helper is overloaded depending on BPF program type. This |
| * description applies to **BPF_PROG_TYPE_SK_LOOKUP** programs. |
| * |
| * Select the *sk* as a result of a socket lookup. |
| * |
| * For the operation to succeed passed socket must be compatible |
| * with the packet description provided by the *ctx* object. |
| * |
| * L4 protocol (**IPPROTO_TCP** or **IPPROTO_UDP**) must |
| * be an exact match. While IP family (**AF_INET** or |
| * **AF_INET6**) must be compatible, that is IPv6 sockets |
| * that are not v6-only can be selected for IPv4 packets. |
| * |
| * Only TCP listeners and UDP unconnected sockets can be |
| * selected. *sk* can also be NULL to reset any previous |
| * selection. |
| * |
| * *flags* argument can combination of following values: |
| * |
| * * **BPF_SK_LOOKUP_F_REPLACE** to override the previous |
| * socket selection, potentially done by a BPF program |
| * that ran before us. |
| * |
| * * **BPF_SK_LOOKUP_F_NO_REUSEPORT** to skip |
| * load-balancing within reuseport group for the socket |
| * being selected. |
| * |
| * On success *ctx->sk* will point to the selected socket. |
| * |
| * Return |
| * 0 on success, or a negative errno in case of failure. |
| * |
| * * **-EAFNOSUPPORT** if socket family (*sk->family*) is |
| * not compatible with packet family (*ctx->family*). |
| * |
| * * **-EEXIST** if socket has been already selected, |
| * potentially by another program, and |
| * **BPF_SK_LOOKUP_F_REPLACE** flag was not specified. |
| * |
| * * **-EINVAL** if unsupported flags were specified. |
| * |
| * * **-EPROTOTYPE** if socket L4 protocol |
| * (*sk->protocol*) doesn't match packet protocol |
| * (*ctx->protocol*). |
| * |
| * * **-ESOCKTNOSUPPORT** if socket is not in allowed |
| * state (TCP listening or UDP unconnected). |
| * |
| * u64 bpf_ktime_get_boot_ns(void) |
| * Description |
| * Return the time elapsed since system boot, in nanoseconds. |
| * Does include the time the system was suspended. |
| * See: **clock_gettime**\ (**CLOCK_BOOTTIME**) |
| * Return |
| * Current *ktime*. |
| * |
| * long bpf_seq_printf(struct seq_file *m, const char *fmt, u32 fmt_size, const void *data, u32 data_len) |
| * Description |
| * **bpf_seq_printf**\ () uses seq_file **seq_printf**\ () to print |
| * out the format string. |
| * The *m* represents the seq_file. The *fmt* and *fmt_size* are for |
| * the format string itself. The *data* and *data_len* are format string |
| * arguments. The *data* are a **u64** array and corresponding format string |
| * values are stored in the array. For strings and pointers where pointees |
| * are accessed, only the pointer values are stored in the *data* array. |
| * The *data_len* is the size of *data* in bytes. |
| * |
| * Formats **%s**, **%p{i,I}{4,6}** requires to read kernel memory. |
| * Reading kernel memory may fail due to either invalid address or |
| * valid address but requiring a major memory fault. If reading kernel memory |
| |