| // SPDX-License-Identifier: GPL-2.0 |
| /* Copyright (c) 2019 Facebook */ |
| #include <linux/rculist.h> |
| #include <linux/list.h> |
| #include <linux/hash.h> |
| #include <linux/types.h> |
| #include <linux/spinlock.h> |
| #include <linux/bpf.h> |
| #include <linux/btf.h> |
| #include <linux/btf_ids.h> |
| #include <linux/bpf_local_storage.h> |
| #include <net/bpf_sk_storage.h> |
| #include <net/sock.h> |
| #include <uapi/linux/sock_diag.h> |
| #include <uapi/linux/btf.h> |
| |
| DEFINE_BPF_STORAGE_CACHE(sk_cache); |
| |
| static struct bpf_local_storage_data * |
| bpf_sk_storage_lookup(struct sock *sk, struct bpf_map *map, bool cacheit_lockit) |
| { |
| struct bpf_local_storage *sk_storage; |
| struct bpf_local_storage_map *smap; |
| |
| sk_storage = rcu_dereference(sk->sk_bpf_storage); |
| if (!sk_storage) |
| return NULL; |
| |
| smap = (struct bpf_local_storage_map *)map; |
| return bpf_local_storage_lookup(sk_storage, smap, cacheit_lockit); |
| } |
| |
| static int bpf_sk_storage_del(struct sock *sk, struct bpf_map *map) |
| { |
| struct bpf_local_storage_data *sdata; |
| |
| sdata = bpf_sk_storage_lookup(sk, map, false); |
| if (!sdata) |
| return -ENOENT; |
| |
| bpf_selem_unlink(SELEM(sdata)); |
| |
| return 0; |
| } |
| |
| /* Called by __sk_destruct() & bpf_sk_storage_clone() */ |
| void bpf_sk_storage_free(struct sock *sk) |
| { |
| struct bpf_local_storage_elem *selem; |
| struct bpf_local_storage *sk_storage; |
| bool free_sk_storage = false; |
| struct hlist_node *n; |
| |
| rcu_read_lock(); |
| sk_storage = rcu_dereference(sk->sk_bpf_storage); |
| if (!sk_storage) { |
| rcu_read_unlock(); |
| return; |
| } |
| |
| /* Netiher the bpf_prog nor the bpf-map's syscall |
| * could be modifying the sk_storage->list now. |
| * Thus, no elem can be added-to or deleted-from the |
| * sk_storage->list by the bpf_prog or by the bpf-map's syscall. |
| * |
| * It is racing with bpf_local_storage_map_free() alone |
| * when unlinking elem from the sk_storage->list and |
| * the map's bucket->list. |
| */ |
| raw_spin_lock_bh(&sk_storage->lock); |
| hlist_for_each_entry_safe(selem, n, &sk_storage->list, snode) { |
| /* Always unlink from map before unlinking from |
| * sk_storage. |
| */ |
| bpf_selem_unlink_map(selem); |
| free_sk_storage = bpf_selem_unlink_storage_nolock(sk_storage, |
| selem, true); |
| } |
| raw_spin_unlock_bh(&sk_storage->lock); |
| rcu_read_unlock(); |
| |
| if (free_sk_storage) |
| kfree_rcu(sk_storage, rcu); |
| } |
| |
| static void bpf_sk_storage_map_free(struct bpf_map *map) |
| { |
| struct bpf_local_storage_map *smap; |
| |
| smap = (struct bpf_local_storage_map *)map; |
| bpf_local_storage_cache_idx_free(&sk_cache, smap->cache_idx); |
| bpf_local_storage_map_free(smap, NULL); |
| } |
| |
| static struct bpf_map *bpf_sk_storage_map_alloc(union bpf_attr *attr) |
| { |
| struct bpf_local_storage_map *smap; |
| |
| smap = bpf_local_storage_map_alloc(attr); |
| if (IS_ERR(smap)) |
| return ERR_CAST(smap); |
| |
| smap->cache_idx = bpf_local_storage_cache_idx_get(&sk_cache); |
| return &smap->map; |
| } |
| |
| static int notsupp_get_next_key(struct bpf_map *map, void *key, |
| void *next_key) |
| { |
| return -ENOTSUPP; |
| } |
| |
| static void *bpf_fd_sk_storage_lookup_elem(struct bpf_map *map, void *key) |
| { |
| struct bpf_local_storage_data *sdata; |
| struct socket *sock; |
| int fd, err; |
| |
| fd = *(int *)key; |
| sock = sockfd_lookup(fd, &err); |
| if (sock) { |
| sdata = bpf_sk_storage_lookup(sock->sk, map, true); |
| sockfd_put(sock); |
| return sdata ? sdata->data : NULL; |
| } |
| |
| return ERR_PTR(err); |
| } |
| |
| static int bpf_fd_sk_storage_update_elem(struct bpf_map *map, void *key, |
| void *value, u64 map_flags) |
| { |
| struct bpf_local_storage_data *sdata; |
| struct socket *sock; |
| int fd, err; |
| |
| fd = *(int *)key; |
| sock = sockfd_lookup(fd, &err); |
| if (sock) { |
| sdata = bpf_local_storage_update( |
| sock->sk, (struct bpf_local_storage_map *)map, value, |
| map_flags); |
| sockfd_put(sock); |
| return PTR_ERR_OR_ZERO(sdata); |
| } |
| |
| return err; |
| } |
| |
| static int bpf_fd_sk_storage_delete_elem(struct bpf_map *map, void *key) |
| { |
| struct socket *sock; |
| int fd, err; |
| |
| fd = *(int *)key; |
| sock = sockfd_lookup(fd, &err); |
| if (sock) { |
| err = bpf_sk_storage_del(sock->sk, map); |
| sockfd_put(sock); |
| return err; |
| } |
| |
| return err; |
| } |
| |
| static struct bpf_local_storage_elem * |
| bpf_sk_storage_clone_elem(struct sock *newsk, |
| struct bpf_local_storage_map *smap, |
| struct bpf_local_storage_elem *selem) |
| { |
| struct bpf_local_storage_elem *copy_selem; |
| |
| copy_selem = bpf_selem_alloc(smap, newsk, NULL, true); |
| if (!copy_selem) |
| return NULL; |
| |
| if (map_value_has_spin_lock(&smap->map)) |
| copy_map_value_locked(&smap->map, SDATA(copy_selem)->data, |
| SDATA(selem)->data, true); |
| else |
| copy_map_value(&smap->map, SDATA(copy_selem)->data, |
| SDATA(selem)->data); |
| |
| return copy_selem; |
| } |
| |
| int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk) |
| { |
| struct bpf_local_storage *new_sk_storage = NULL; |
| struct bpf_local_storage *sk_storage; |
| struct bpf_local_storage_elem *selem; |
| int ret = 0; |
| |
| RCU_INIT_POINTER(newsk->sk_bpf_storage, NULL); |
| |
| rcu_read_lock(); |
| sk_storage = rcu_dereference(sk->sk_bpf_storage); |
| |
| if (!sk_storage || hlist_empty(&sk_storage->list)) |
| goto out; |
| |
| hlist_for_each_entry_rcu(selem, &sk_storage->list, snode) { |
| struct bpf_local_storage_elem *copy_selem; |
| struct bpf_local_storage_map *smap; |
| struct bpf_map *map; |
| |
| smap = rcu_dereference(SDATA(selem)->smap); |
| if (!(smap->map.map_flags & BPF_F_CLONE)) |
| continue; |
| |
| /* Note that for lockless listeners adding new element |
| * here can race with cleanup in bpf_local_storage_map_free. |
| * Try to grab map refcnt to make sure that it's still |
| * alive and prevent concurrent removal. |
| */ |
| map = bpf_map_inc_not_zero(&smap->map); |
| if (IS_ERR(map)) |
| continue; |
| |
| copy_selem = bpf_sk_storage_clone_elem(newsk, smap, selem); |
| if (!copy_selem) { |
| ret = -ENOMEM; |
| bpf_map_put(map); |
| goto out; |
| } |
| |
| if (new_sk_storage) { |
| bpf_selem_link_map(smap, copy_selem); |
| bpf_selem_link_storage_nolock(new_sk_storage, copy_selem); |
| } else { |
| ret = bpf_local_storage_alloc(newsk, smap, copy_selem); |
| if (ret) { |
| kfree(copy_selem); |
| atomic_sub(smap->elem_size, |
| &newsk->sk_omem_alloc); |
| bpf_map_put(map); |
| goto out; |
| } |
| |
| new_sk_storage = |
| rcu_dereference(copy_selem->local_storage); |
| } |
| bpf_map_put(map); |
| } |
| |
| out: |
| rcu_read_unlock(); |
| |
| /* In case of an error, don't free anything explicitly here, the |
| * caller is responsible to call bpf_sk_storage_free. |
| */ |
| |
| return ret; |
| } |
| |
| BPF_CALL_4(bpf_sk_storage_get, struct bpf_map *, map, struct sock *, sk, |
| void *, value, u64, flags) |
| { |
| struct bpf_local_storage_data *sdata; |
| |
| if (!sk || !sk_fullsock(sk) || flags > BPF_SK_STORAGE_GET_F_CREATE) |
| return (unsigned long)NULL; |
| |
| sdata = bpf_sk_storage_lookup(sk, map, true); |
| if (sdata) |
| return (unsigned long)sdata->data; |
| |
| if (flags == BPF_SK_STORAGE_GET_F_CREATE && |
| /* Cannot add new elem to a going away sk. |
| * Otherwise, the new elem may become a leak |
| * (and also other memory issues during map |
| * destruction). |
| */ |
| refcount_inc_not_zero(&sk->sk_refcnt)) { |
| sdata = bpf_local_storage_update( |
| sk, (struct bpf_local_storage_map *)map, value, |
| BPF_NOEXIST); |
| /* sk must be a fullsock (guaranteed by verifier), |
| * so sock_gen_put() is unnecessary. |
| */ |
| sock_put(sk); |
| return IS_ERR(sdata) ? |
| (unsigned long)NULL : (unsigned long)sdata->data; |
| } |
| |
| return (unsigned long)NULL; |
| } |
| |
| BPF_CALL_2(bpf_sk_storage_delete, struct bpf_map *, map, struct sock *, sk) |
| { |
| if (!sk || !sk_fullsock(sk)) |
| return -EINVAL; |
| |
| if (refcount_inc_not_zero(&sk->sk_refcnt)) { |
| int err; |
| |
| err = bpf_sk_storage_del(sk, map); |
| sock_put(sk); |
| return err; |
| } |
| |
| return -ENOENT; |
| } |
| |
| static int bpf_sk_storage_charge(struct bpf_local_storage_map *smap, |
| void *owner, u32 size) |
| { |
| struct sock *sk = (struct sock *)owner; |
| |
| /* same check as in sock_kmalloc() */ |
| if (size <= sysctl_optmem_max && |
| atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) { |
| atomic_add(size, &sk->sk_omem_alloc); |
| return 0; |
| } |
| |
| return -ENOMEM; |
| } |
| |
| static void bpf_sk_storage_uncharge(struct bpf_local_storage_map *smap, |
| void *owner, u32 size) |
| { |
| struct sock *sk = owner; |
| |
| atomic_sub(size, &sk->sk_omem_alloc); |
| } |
| |
| static struct bpf_local_storage __rcu ** |
| bpf_sk_storage_ptr(void *owner) |
| { |
| struct sock *sk = owner; |
| |
| return &sk->sk_bpf_storage; |
| } |
| |
| static int sk_storage_map_btf_id; |
| const struct bpf_map_ops sk_storage_map_ops = { |
| .map_meta_equal = bpf_map_meta_equal, |
| .map_alloc_check = bpf_local_storage_map_alloc_check, |
| .map_alloc = bpf_sk_storage_map_alloc, |
| .map_free = bpf_sk_storage_map_free, |
| .map_get_next_key = notsupp_get_next_key, |
| .map_lookup_elem = bpf_fd_sk_storage_lookup_elem, |
| .map_update_elem = bpf_fd_sk_storage_update_elem, |
| .map_delete_elem = bpf_fd_sk_storage_delete_elem, |
| .map_check_btf = bpf_local_storage_map_check_btf, |
| .map_btf_name = "bpf_local_storage_map", |
| .map_btf_id = &sk_storage_map_btf_id, |
| .map_local_storage_charge = bpf_sk_storage_charge, |
| .map_local_storage_uncharge = bpf_sk_storage_uncharge, |
| .map_owner_storage_ptr = bpf_sk_storage_ptr, |
| }; |
| |
| const struct bpf_func_proto bpf_sk_storage_get_proto = { |
| .func = bpf_sk_storage_get, |
| .gpl_only = false, |
| .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL, |
| .arg1_type = ARG_CONST_MAP_PTR, |
| .arg2_type = ARG_PTR_TO_BTF_ID_SOCK_COMMON, |
| .arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL, |
| .arg4_type = ARG_ANYTHING, |
| }; |
| |
| const struct bpf_func_proto bpf_sk_storage_get_cg_sock_proto = { |
| .func = bpf_sk_storage_get, |
| .gpl_only = false, |
| .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL, |
| .arg1_type = ARG_CONST_MAP_PTR, |
| .arg2_type = ARG_PTR_TO_CTX, /* context is 'struct sock' */ |
| .arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL, |
| .arg4_type = ARG_ANYTHING, |
| }; |
| |
| const struct bpf_func_proto bpf_sk_storage_delete_proto = { |
| .func = bpf_sk_storage_delete, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_CONST_MAP_PTR, |
| .arg2_type = ARG_PTR_TO_BTF_ID_SOCK_COMMON, |
| }; |
| |
| static bool bpf_sk_storage_tracing_allowed(const struct bpf_prog *prog) |
| { |
| const struct btf *btf_vmlinux; |
| const struct btf_type *t; |
| const char *tname; |
| u32 btf_id; |
| |
| if (prog->aux->dst_prog) |
| return false; |
| |
| /* Ensure the tracing program is not tracing |
| * any bpf_sk_storage*() function and also |
| * use the bpf_sk_storage_(get|delete) helper. |
| */ |
| switch (prog->expected_attach_type) { |
| case BPF_TRACE_ITER: |
| case BPF_TRACE_RAW_TP: |
| /* bpf_sk_storage has no trace point */ |
| return true; |
| case BPF_TRACE_FENTRY: |
| case BPF_TRACE_FEXIT: |
| btf_vmlinux = bpf_get_btf_vmlinux(); |
| btf_id = prog->aux->attach_btf_id; |
| t = btf_type_by_id(btf_vmlinux, btf_id); |
| tname = btf_name_by_offset(btf_vmlinux, t->name_off); |
| return !!strncmp(tname, "bpf_sk_storage", |
| strlen("bpf_sk_storage")); |
| default: |
| return false; |
| } |
| |
| return false; |
| } |
| |
| BPF_CALL_4(bpf_sk_storage_get_tracing, struct bpf_map *, map, struct sock *, sk, |
| void *, value, u64, flags) |
| { |
| if (in_irq() || in_nmi()) |
| return (unsigned long)NULL; |
| |
| return (unsigned long)____bpf_sk_storage_get(map, sk, value, flags); |
| } |
| |
| BPF_CALL_2(bpf_sk_storage_delete_tracing, struct bpf_map *, map, |
| struct sock *, sk) |
| { |
| if (in_irq() || in_nmi()) |
| return -EPERM; |
| |
| return ____bpf_sk_storage_delete(map, sk); |
| } |
| |
| const struct bpf_func_proto bpf_sk_storage_get_tracing_proto = { |
| .func = bpf_sk_storage_get_tracing, |
| .gpl_only = false, |
| .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL, |
| .arg1_type = ARG_CONST_MAP_PTR, |
| .arg2_type = ARG_PTR_TO_BTF_ID, |
| .arg2_btf_id = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON], |
| .arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL, |
| .arg4_type = ARG_ANYTHING, |
| .allowed = bpf_sk_storage_tracing_allowed, |
| }; |
| |
| const struct bpf_func_proto bpf_sk_storage_delete_tracing_proto = { |
| .func = bpf_sk_storage_delete_tracing, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_CONST_MAP_PTR, |
| .arg2_type = ARG_PTR_TO_BTF_ID, |
| .arg2_btf_id = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON], |
| .allowed = bpf_sk_storage_tracing_allowed, |
| }; |
| |
| struct bpf_sk_storage_diag { |
| u32 nr_maps; |
| struct bpf_map *maps[]; |
| }; |
| |
| /* The reply will be like: |
| * INET_DIAG_BPF_SK_STORAGES (nla_nest) |
| * SK_DIAG_BPF_STORAGE (nla_nest) |
| * SK_DIAG_BPF_STORAGE_MAP_ID (nla_put_u32) |
| * SK_DIAG_BPF_STORAGE_MAP_VALUE (nla_reserve_64bit) |
| * SK_DIAG_BPF_STORAGE (nla_nest) |
| * SK_DIAG_BPF_STORAGE_MAP_ID (nla_put_u32) |
| * SK_DIAG_BPF_STORAGE_MAP_VALUE (nla_reserve_64bit) |
| * .... |
| */ |
| static int nla_value_size(u32 value_size) |
| { |
| /* SK_DIAG_BPF_STORAGE (nla_nest) |
| * SK_DIAG_BPF_STORAGE_MAP_ID (nla_put_u32) |
| * SK_DIAG_BPF_STORAGE_MAP_VALUE (nla_reserve_64bit) |
| */ |
| return nla_total_size(0) + nla_total_size(sizeof(u32)) + |
| nla_total_size_64bit(value_size); |
| } |
| |
| void bpf_sk_storage_diag_free(struct bpf_sk_storage_diag *diag) |
| { |
| u32 i; |
| |
| if (!diag) |
| return; |
| |
| for (i = 0; i < diag->nr_maps; i++) |
| bpf_map_put(diag->maps[i]); |
| |
| kfree(diag); |
| } |
| EXPORT_SYMBOL_GPL(bpf_sk_storage_diag_free); |
| |
| static bool diag_check_dup(const struct bpf_sk_storage_diag *diag, |
| const struct bpf_map *map) |
| { |
| u32 i; |
| |
| for (i = 0; i < diag->nr_maps; i++) { |
| if (diag->maps[i] == map) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| struct bpf_sk_storage_diag * |
| bpf_sk_storage_diag_alloc(const struct nlattr *nla_stgs) |
| { |
| struct bpf_sk_storage_diag *diag; |
| struct nlattr *nla; |
| u32 nr_maps = 0; |
| int rem, err; |
| |
| /* bpf_local_storage_map is currently limited to CAP_SYS_ADMIN as |
| * the map_alloc_check() side also does. |
| */ |
| if (!bpf_capable()) |
| return ERR_PTR(-EPERM); |
| |
| nla_for_each_nested(nla, nla_stgs, rem) { |
| if (nla_type(nla) == SK_DIAG_BPF_STORAGE_REQ_MAP_FD) |
| nr_maps++; |
| } |
| |
| diag = kzalloc(struct_size(diag, maps, nr_maps), GFP_KERNEL); |
| if (!diag) |
| return ERR_PTR(-ENOMEM); |
| |
| nla_for_each_nested(nla, nla_stgs, rem) { |
| struct bpf_map *map; |
| int map_fd; |
| |
| if (nla_type(nla) != SK_DIAG_BPF_STORAGE_REQ_MAP_FD) |
| continue; |
| |
| map_fd = nla_get_u32(nla); |
| map = bpf_map_get(map_fd); |
| if (IS_ERR(map)) { |
| err = PTR_ERR(map); |
| goto err_free; |
| } |
| if (map->map_type != BPF_MAP_TYPE_SK_STORAGE) { |
| bpf_map_put(map); |
| err = -EINVAL; |
| goto err_free; |
| } |
| if (diag_check_dup(diag, map)) { |
| bpf_map_put(map); |
| err = -EEXIST; |
| goto err_free; |
| } |
| diag->maps[diag->nr_maps++] = map; |
| } |
| |
| return diag; |
| |
| err_free: |
| bpf_sk_storage_diag_free(diag); |
| return ERR_PTR(err); |
| } |
| EXPORT_SYMBOL_GPL(bpf_sk_storage_diag_alloc); |
| |
| static int diag_get(struct bpf_local_storage_data *sdata, struct sk_buff *skb) |
| { |
| struct nlattr *nla_stg, *nla_value; |
| struct bpf_local_storage_map *smap; |
| |
| /* It cannot exceed max nlattr's payload */ |
| BUILD_BUG_ON(U16_MAX - NLA_HDRLEN < BPF_LOCAL_STORAGE_MAX_VALUE_SIZE); |
| |
| nla_stg = nla_nest_start(skb, SK_DIAG_BPF_STORAGE); |
| if (!nla_stg) |
| return -EMSGSIZE; |
| |
| smap = rcu_dereference(sdata->smap); |
| if (nla_put_u32(skb, SK_DIAG_BPF_STORAGE_MAP_ID, smap->map.id)) |
| goto errout; |
| |
| nla_value = nla_reserve_64bit(skb, SK_DIAG_BPF_STORAGE_MAP_VALUE, |
| smap->map.value_size, |
| SK_DIAG_BPF_STORAGE_PAD); |
| if (!nla_value) |
| goto errout; |
| |
| if (map_value_has_spin_lock(&smap->map)) |
| copy_map_value_locked(&smap->map, nla_data(nla_value), |
| sdata->data, true); |
| else |
| copy_map_value(&smap->map, nla_data(nla_value), sdata->data); |
| |
| nla_nest_end(skb, nla_stg); |
| return 0; |
| |
| errout: |
| nla_nest_cancel(skb, nla_stg); |
| return -EMSGSIZE; |
| } |
| |
| static int bpf_sk_storage_diag_put_all(struct sock *sk, struct sk_buff *skb, |
| int stg_array_type, |
| unsigned int *res_diag_size) |
| { |
| /* stg_array_type (e.g. INET_DIAG_BPF_SK_STORAGES) */ |
| unsigned int diag_size = nla_total_size(0); |
| struct bpf_local_storage *sk_storage; |
| struct bpf_local_storage_elem *selem; |
| struct bpf_local_storage_map *smap; |
| struct nlattr *nla_stgs; |
| unsigned int saved_len; |
| int err = 0; |
| |
| rcu_read_lock(); |
| |
| sk_storage = rcu_dereference(sk->sk_bpf_storage); |
| if (!sk_storage || hlist_empty(&sk_storage->list)) { |
| rcu_read_unlock(); |
| return 0; |
| } |
| |
| nla_stgs = nla_nest_start(skb, stg_array_type); |
| if (!nla_stgs) |
| /* Continue to learn diag_size */ |
| err = -EMSGSIZE; |
| |
| saved_len = skb->len; |
| hlist_for_each_entry_rcu(selem, &sk_storage->list, snode) { |
| smap = rcu_dereference(SDATA(selem)->smap); |
| diag_size += nla_value_size(smap->map.value_size); |
| |
| if (nla_stgs && diag_get(SDATA(selem), skb)) |
| /* Continue to learn diag_size */ |
| err = -EMSGSIZE; |
| } |
| |
| rcu_read_unlock(); |
| |
| if (nla_stgs) { |
| if (saved_len == skb->len) |
| nla_nest_cancel(skb, nla_stgs); |
| else |
| nla_nest_end(skb, nla_stgs); |
| } |
| |
| if (diag_size == nla_total_size(0)) { |
| *res_diag_size = 0; |
| return 0; |
| } |
| |
| *res_diag_size = diag_size; |
| return err; |
| } |
| |
| int bpf_sk_storage_diag_put(struct bpf_sk_storage_diag *diag, |
| struct sock *sk, struct sk_buff *skb, |
| int stg_array_type, |
| unsigned int *res_diag_size) |
| { |
| /* stg_array_type (e.g. INET_DIAG_BPF_SK_STORAGES) */ |
| unsigned int diag_size = nla_total_size(0); |
| struct bpf_local_storage *sk_storage; |
| struct bpf_local_storage_data *sdata; |
| struct nlattr *nla_stgs; |
| unsigned int saved_len; |
| int err = 0; |
| u32 i; |
| |
| *res_diag_size = 0; |
| |
| /* No map has been specified. Dump all. */ |
| if (!diag->nr_maps) |
| return bpf_sk_storage_diag_put_all(sk, skb, stg_array_type, |
| res_diag_size); |
| |
| rcu_read_lock(); |
| sk_storage = rcu_dereference(sk->sk_bpf_storage); |
| if (!sk_storage || hlist_empty(&sk_storage->list)) { |
| rcu_read_unlock(); |
| return 0; |
| } |
| |
| nla_stgs = nla_nest_start(skb, stg_array_type); |
| if (!nla_stgs) |
| /* Continue to learn diag_size */ |
| err = -EMSGSIZE; |
| |
| saved_len = skb->len; |
| for (i = 0; i < diag->nr_maps; i++) { |
| sdata = bpf_local_storage_lookup(sk_storage, |
| (struct bpf_local_storage_map *)diag->maps[i], |
| false); |
| |
| if (!sdata) |
| continue; |
| |
| diag_size += nla_value_size(diag->maps[i]->value_size); |
| |
| if (nla_stgs && diag_get(sdata, skb)) |
| /* Continue to learn diag_size */ |
| err = -EMSGSIZE; |
| } |
| rcu_read_unlock(); |
| |
| if (nla_stgs) { |
| if (saved_len == skb->len) |
| nla_nest_cancel(skb, nla_stgs); |
| else |
| nla_nest_end(skb, nla_stgs); |
| } |
| |
| if (diag_size == nla_total_size(0)) { |
| *res_diag_size = 0; |
| return 0; |
| } |
| |
| *res_diag_size = diag_size; |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(bpf_sk_storage_diag_put); |
| |
| struct bpf_iter_seq_sk_storage_map_info { |
| struct bpf_map *map; |
| unsigned int bucket_id; |
| unsigned skip_elems; |
| }; |
| |
| static struct bpf_local_storage_elem * |
| bpf_sk_storage_map_seq_find_next(struct bpf_iter_seq_sk_storage_map_info *info, |
| struct bpf_local_storage_elem *prev_selem) |
| __acquires(RCU) __releases(RCU) |
| { |
| struct bpf_local_storage *sk_storage; |
| struct bpf_local_storage_elem *selem; |
| u32 skip_elems = info->skip_elems; |
| struct bpf_local_storage_map *smap; |
| u32 bucket_id = info->bucket_id; |
| u32 i, count, n_buckets; |
| struct bpf_local_storage_map_bucket *b; |
| |
| smap = (struct bpf_local_storage_map *)info->map; |
| n_buckets = 1U << smap->bucket_log; |
| if (bucket_id >= n_buckets) |
| return NULL; |
| |
| /* try to find next selem in the same bucket */ |
| selem = prev_selem; |
| count = 0; |
| while (selem) { |
| selem = hlist_entry_safe(rcu_dereference(hlist_next_rcu(&selem->map_node)), |
| struct bpf_local_storage_elem, map_node); |
| if (!selem) { |
| /* not found, unlock and go to the next bucket */ |
| b = &smap->buckets[bucket_id++]; |
| rcu_read_unlock(); |
| skip_elems = 0; |
| break; |
| } |
| sk_storage = rcu_dereference(selem->local_storage); |
| if (sk_storage) { |
| info->skip_elems = skip_elems + count; |
| return selem; |
| } |
| count++; |
| } |
| |
| for (i = bucket_id; i < (1U << smap->bucket_log); i++) { |
| b = &smap->buckets[i]; |
| rcu_read_lock(); |
| count = 0; |
| hlist_for_each_entry_rcu(selem, &b->list, map_node) { |
| sk_storage = rcu_dereference(selem->local_storage); |
| if (sk_storage && count >= skip_elems) { |
| info->bucket_id = i; |
| info->skip_elems = count; |
| return selem; |
| } |
| count++; |
| } |
| rcu_read_unlock(); |
| skip_elems = 0; |
| } |
| |
| info->bucket_id = i; |
| info->skip_elems = 0; |
| return NULL; |
| } |
| |
| static void *bpf_sk_storage_map_seq_start(struct seq_file *seq, loff_t *pos) |
| { |
| struct bpf_local_storage_elem *selem; |
| |
| selem = bpf_sk_storage_map_seq_find_next(seq->private, NULL); |
| if (!selem) |
| return NULL; |
| |
| if (*pos == 0) |
| ++*pos; |
| return selem; |
| } |
| |
| static void *bpf_sk_storage_map_seq_next(struct seq_file *seq, void *v, |
| loff_t *pos) |
| { |
| struct bpf_iter_seq_sk_storage_map_info *info = seq->private; |
| |
| ++*pos; |
| ++info->skip_elems; |
| return bpf_sk_storage_map_seq_find_next(seq->private, v); |
| } |
| |
| struct bpf_iter__bpf_sk_storage_map { |
| __bpf_md_ptr(struct bpf_iter_meta *, meta); |
| __bpf_md_ptr(struct bpf_map *, map); |
| __bpf_md_ptr(struct sock *, sk); |
| __bpf_md_ptr(void *, value); |
| }; |
| |
| DEFINE_BPF_ITER_FUNC(bpf_sk_storage_map, struct bpf_iter_meta *meta, |
| struct bpf_map *map, struct sock *sk, |
| void *value) |
| |
| static int __bpf_sk_storage_map_seq_show(struct seq_file *seq, |
| struct bpf_local_storage_elem *selem) |
| { |
| struct bpf_iter_seq_sk_storage_map_info *info = seq->private; |
| struct bpf_iter__bpf_sk_storage_map ctx = {}; |
| struct bpf_local_storage *sk_storage; |
| struct bpf_iter_meta meta; |
| struct bpf_prog *prog; |
| int ret = 0; |
| |
| meta.seq = seq; |
| prog = bpf_iter_get_info(&meta, selem == NULL); |
| if (prog) { |
| ctx.meta = &meta; |
| ctx.map = info->map; |
| if (selem) { |
| sk_storage = rcu_dereference(selem->local_storage); |
| ctx.sk = sk_storage->owner; |
| ctx.value = SDATA(selem)->data; |
| } |
| ret = bpf_iter_run_prog(prog, &ctx); |
| } |
| |
| return ret; |
| } |
| |
| static int bpf_sk_storage_map_seq_show(struct seq_file *seq, void *v) |
| { |
| return __bpf_sk_storage_map_seq_show(seq, v); |
| } |
| |
| static void bpf_sk_storage_map_seq_stop(struct seq_file *seq, void *v) |
| __releases(RCU) |
| { |
| if (!v) |
| (void)__bpf_sk_storage_map_seq_show(seq, v); |
| else |
| rcu_read_unlock(); |
| } |
| |
| static int bpf_iter_init_sk_storage_map(void *priv_data, |
| struct bpf_iter_aux_info *aux) |
| { |
| struct bpf_iter_seq_sk_storage_map_info *seq_info = priv_data; |
| |
| seq_info->map = aux->map; |
| return 0; |
| } |
| |
| static int bpf_iter_attach_map(struct bpf_prog *prog, |
| union bpf_iter_link_info *linfo, |
| struct bpf_iter_aux_info *aux) |
| { |
| struct bpf_map *map; |
| int err = -EINVAL; |
| |
| if (!linfo->map.map_fd) |
| return -EBADF; |
| |
| map = bpf_map_get_with_uref(linfo->map.map_fd); |
| if (IS_ERR(map)) |
| return PTR_ERR(map); |
| |
| if (map->map_type != BPF_MAP_TYPE_SK_STORAGE) |
| goto put_map; |
| |
| if (prog->aux->max_rdonly_access > map->value_size) { |
| err = -EACCES; |
| goto put_map; |
| } |
| |
| aux->map = map; |
| return 0; |
| |
| put_map: |
| bpf_map_put_with_uref(map); |
| return err; |
| } |
| |
| static void bpf_iter_detach_map(struct bpf_iter_aux_info *aux) |
| { |
| bpf_map_put_with_uref(aux->map); |
| } |
| |
| static const struct seq_operations bpf_sk_storage_map_seq_ops = { |
| .start = bpf_sk_storage_map_seq_start, |
| .next = bpf_sk_storage_map_seq_next, |
| .stop = bpf_sk_storage_map_seq_stop, |
| .show = bpf_sk_storage_map_seq_show, |
| }; |
| |
| static const struct bpf_iter_seq_info iter_seq_info = { |
| .seq_ops = &bpf_sk_storage_map_seq_ops, |
| .init_seq_private = bpf_iter_init_sk_storage_map, |
| .fini_seq_private = NULL, |
| .seq_priv_size = sizeof(struct bpf_iter_seq_sk_storage_map_info), |
| }; |
| |
| static struct bpf_iter_reg bpf_sk_storage_map_reg_info = { |
| .target = "bpf_sk_storage_map", |
| .attach_target = bpf_iter_attach_map, |
| .detach_target = bpf_iter_detach_map, |
| .show_fdinfo = bpf_iter_map_show_fdinfo, |
| .fill_link_info = bpf_iter_map_fill_link_info, |
| .ctx_arg_info_size = 2, |
| .ctx_arg_info = { |
| { offsetof(struct bpf_iter__bpf_sk_storage_map, sk), |
| PTR_TO_BTF_ID_OR_NULL }, |
| { offsetof(struct bpf_iter__bpf_sk_storage_map, value), |
| PTR_TO_RDWR_BUF_OR_NULL }, |
| }, |
| .seq_info = &iter_seq_info, |
| }; |
| |
| static int __init bpf_sk_storage_map_iter_init(void) |
| { |
| bpf_sk_storage_map_reg_info.ctx_arg_info[0].btf_id = |
| btf_sock_ids[BTF_SOCK_TYPE_SOCK]; |
| return bpf_iter_reg_target(&bpf_sk_storage_map_reg_info); |
| } |
| late_initcall(bpf_sk_storage_map_iter_init); |