| // SPDX-License-Identifier: GPL-2.0 |
| /* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */ |
| |
| #include <linux/bpf.h> |
| #include <linux/filter.h> |
| #include <linux/errno.h> |
| #include <linux/file.h> |
| #include <linux/net.h> |
| #include <linux/workqueue.h> |
| #include <linux/skmsg.h> |
| #include <linux/list.h> |
| #include <linux/jhash.h> |
| |
| struct bpf_stab { |
| struct bpf_map map; |
| struct sock **sks; |
| struct sk_psock_progs progs; |
| raw_spinlock_t lock; |
| }; |
| |
| #define SOCK_CREATE_FLAG_MASK \ |
| (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY) |
| |
| static struct bpf_map *sock_map_alloc(union bpf_attr *attr) |
| { |
| struct bpf_stab *stab; |
| u64 cost; |
| int err; |
| |
| if (!capable(CAP_NET_ADMIN)) |
| return ERR_PTR(-EPERM); |
| if (attr->max_entries == 0 || |
| attr->key_size != 4 || |
| attr->value_size != 4 || |
| attr->map_flags & ~SOCK_CREATE_FLAG_MASK) |
| return ERR_PTR(-EINVAL); |
| |
| stab = kzalloc(sizeof(*stab), GFP_USER); |
| if (!stab) |
| return ERR_PTR(-ENOMEM); |
| |
| bpf_map_init_from_attr(&stab->map, attr); |
| raw_spin_lock_init(&stab->lock); |
| |
| /* Make sure page count doesn't overflow. */ |
| cost = (u64) stab->map.max_entries * sizeof(struct sock *); |
| err = bpf_map_charge_init(&stab->map.memory, cost); |
| if (err) |
| goto free_stab; |
| |
| stab->sks = bpf_map_area_alloc(stab->map.max_entries * |
| sizeof(struct sock *), |
| stab->map.numa_node); |
| if (stab->sks) |
| return &stab->map; |
| err = -ENOMEM; |
| bpf_map_charge_finish(&stab->map.memory); |
| free_stab: |
| kfree(stab); |
| return ERR_PTR(err); |
| } |
| |
| int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog) |
| { |
| u32 ufd = attr->target_fd; |
| struct bpf_map *map; |
| struct fd f; |
| int ret; |
| |
| f = fdget(ufd); |
| map = __bpf_map_get(f); |
| if (IS_ERR(map)) |
| return PTR_ERR(map); |
| ret = sock_map_prog_update(map, prog, attr->attach_type); |
| fdput(f); |
| return ret; |
| } |
| |
| static void sock_map_sk_acquire(struct sock *sk) |
| __acquires(&sk->sk_lock.slock) |
| { |
| lock_sock(sk); |
| preempt_disable(); |
| rcu_read_lock(); |
| } |
| |
| static void sock_map_sk_release(struct sock *sk) |
| __releases(&sk->sk_lock.slock) |
| { |
| rcu_read_unlock(); |
| preempt_enable(); |
| release_sock(sk); |
| } |
| |
| static void sock_map_add_link(struct sk_psock *psock, |
| struct sk_psock_link *link, |
| struct bpf_map *map, void *link_raw) |
| { |
| link->link_raw = link_raw; |
| link->map = map; |
| spin_lock_bh(&psock->link_lock); |
| list_add_tail(&link->list, &psock->link); |
| spin_unlock_bh(&psock->link_lock); |
| } |
| |
| static void sock_map_del_link(struct sock *sk, |
| struct sk_psock *psock, void *link_raw) |
| { |
| struct sk_psock_link *link, *tmp; |
| bool strp_stop = false; |
| |
| spin_lock_bh(&psock->link_lock); |
| list_for_each_entry_safe(link, tmp, &psock->link, list) { |
| if (link->link_raw == link_raw) { |
| struct bpf_map *map = link->map; |
| struct bpf_stab *stab = container_of(map, struct bpf_stab, |
| map); |
| if (psock->parser.enabled && stab->progs.skb_parser) |
| strp_stop = true; |
| list_del(&link->list); |
| sk_psock_free_link(link); |
| } |
| } |
| spin_unlock_bh(&psock->link_lock); |
| if (strp_stop) { |
| write_lock_bh(&sk->sk_callback_lock); |
| sk_psock_stop_strp(sk, psock); |
| write_unlock_bh(&sk->sk_callback_lock); |
| } |
| } |
| |
| static void sock_map_unref(struct sock *sk, void *link_raw) |
| { |
| struct sk_psock *psock = sk_psock(sk); |
| |
| if (likely(psock)) { |
| sock_map_del_link(sk, psock, link_raw); |
| sk_psock_put(sk, psock); |
| } |
| } |
| |
| static int sock_map_link(struct bpf_map *map, struct sk_psock_progs *progs, |
| struct sock *sk) |
| { |
| struct bpf_prog *msg_parser, *skb_parser, *skb_verdict; |
| bool skb_progs, sk_psock_is_new = false; |
| struct sk_psock *psock; |
| int ret; |
| |
| skb_verdict = READ_ONCE(progs->skb_verdict); |
| skb_parser = READ_ONCE(progs->skb_parser); |
| skb_progs = skb_parser && skb_verdict; |
| if (skb_progs) { |
| skb_verdict = bpf_prog_inc_not_zero(skb_verdict); |
| if (IS_ERR(skb_verdict)) |
| return PTR_ERR(skb_verdict); |
| skb_parser = bpf_prog_inc_not_zero(skb_parser); |
| if (IS_ERR(skb_parser)) { |
| bpf_prog_put(skb_verdict); |
| return PTR_ERR(skb_parser); |
| } |
| } |
| |
| msg_parser = READ_ONCE(progs->msg_parser); |
| if (msg_parser) { |
| msg_parser = bpf_prog_inc_not_zero(msg_parser); |
| if (IS_ERR(msg_parser)) { |
| ret = PTR_ERR(msg_parser); |
| goto out; |
| } |
| } |
| |
| psock = sk_psock_get_checked(sk); |
| if (IS_ERR(psock)) { |
| ret = PTR_ERR(psock); |
| goto out_progs; |
| } |
| |
| if (psock) { |
| if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) || |
| (skb_progs && READ_ONCE(psock->progs.skb_parser))) { |
| sk_psock_put(sk, psock); |
| ret = -EBUSY; |
| goto out_progs; |
| } |
| } else { |
| psock = sk_psock_init(sk, map->numa_node); |
| if (!psock) { |
| ret = -ENOMEM; |
| goto out_progs; |
| } |
| sk_psock_is_new = true; |
| } |
| |
| if (msg_parser) |
| psock_set_prog(&psock->progs.msg_parser, msg_parser); |
| if (sk_psock_is_new) { |
| ret = tcp_bpf_init(sk); |
| if (ret < 0) |
| goto out_drop; |
| } else { |
| tcp_bpf_reinit(sk); |
| } |
| |
| write_lock_bh(&sk->sk_callback_lock); |
| if (skb_progs && !psock->parser.enabled) { |
| ret = sk_psock_init_strp(sk, psock); |
| if (ret) { |
| write_unlock_bh(&sk->sk_callback_lock); |
| goto out_drop; |
| } |
| psock_set_prog(&psock->progs.skb_verdict, skb_verdict); |
| psock_set_prog(&psock->progs.skb_parser, skb_parser); |
| sk_psock_start_strp(sk, psock); |
| } |
| write_unlock_bh(&sk->sk_callback_lock); |
| return 0; |
| out_drop: |
| sk_psock_put(sk, psock); |
| out_progs: |
| if (msg_parser) |
| bpf_prog_put(msg_parser); |
| out: |
| if (skb_progs) { |
| bpf_prog_put(skb_verdict); |
| bpf_prog_put(skb_parser); |
| } |
| return ret; |
| } |
| |
| static void sock_map_free(struct bpf_map *map) |
| { |
| struct bpf_stab *stab = container_of(map, struct bpf_stab, map); |
| int i; |
| |
| /* After the sync no updates or deletes will be in-flight so it |
| * is safe to walk map and remove entries without risking a race |
| * in EEXIST update case. |
| */ |
| synchronize_rcu(); |
| for (i = 0; i < stab->map.max_entries; i++) { |
| struct sock **psk = &stab->sks[i]; |
| struct sock *sk; |
| |
| sk = xchg(psk, NULL); |
| if (sk) { |
| lock_sock(sk); |
| rcu_read_lock(); |
| sock_map_unref(sk, psk); |
| rcu_read_unlock(); |
| release_sock(sk); |
| } |
| } |
| |
| /* wait for psock readers accessing its map link */ |
| synchronize_rcu(); |
| |
| bpf_map_area_free(stab->sks); |
| kfree(stab); |
| } |
| |
| static void sock_map_release_progs(struct bpf_map *map) |
| { |
| psock_progs_drop(&container_of(map, struct bpf_stab, map)->progs); |
| } |
| |
| static struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key) |
| { |
| struct bpf_stab *stab = container_of(map, struct bpf_stab, map); |
| |
| WARN_ON_ONCE(!rcu_read_lock_held()); |
| |
| if (unlikely(key >= map->max_entries)) |
| return NULL; |
| return READ_ONCE(stab->sks[key]); |
| } |
| |
| static void *sock_map_lookup(struct bpf_map *map, void *key) |
| { |
| return ERR_PTR(-EOPNOTSUPP); |
| } |
| |
| static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test, |
| struct sock **psk) |
| { |
| struct sock *sk; |
| int err = 0; |
| |
| raw_spin_lock_bh(&stab->lock); |
| sk = *psk; |
| if (!sk_test || sk_test == sk) |
| sk = xchg(psk, NULL); |
| |
| if (likely(sk)) |
| sock_map_unref(sk, psk); |
| else |
| err = -EINVAL; |
| |
| raw_spin_unlock_bh(&stab->lock); |
| return err; |
| } |
| |
| static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk, |
| void *link_raw) |
| { |
| struct bpf_stab *stab = container_of(map, struct bpf_stab, map); |
| |
| __sock_map_delete(stab, sk, link_raw); |
| } |
| |
| static int sock_map_delete_elem(struct bpf_map *map, void *key) |
| { |
| struct bpf_stab *stab = container_of(map, struct bpf_stab, map); |
| u32 i = *(u32 *)key; |
| struct sock **psk; |
| |
| if (unlikely(i >= map->max_entries)) |
| return -EINVAL; |
| |
| psk = &stab->sks[i]; |
| return __sock_map_delete(stab, NULL, psk); |
| } |
| |
| static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next) |
| { |
| struct bpf_stab *stab = container_of(map, struct bpf_stab, map); |
| u32 i = key ? *(u32 *)key : U32_MAX; |
| u32 *key_next = next; |
| |
| if (i == stab->map.max_entries - 1) |
| return -ENOENT; |
| if (i >= stab->map.max_entries) |
| *key_next = 0; |
| else |
| *key_next = i + 1; |
| return 0; |
| } |
| |
| static int sock_map_update_common(struct bpf_map *map, u32 idx, |
| struct sock *sk, u64 flags) |
| { |
| struct bpf_stab *stab = container_of(map, struct bpf_stab, map); |
| struct inet_connection_sock *icsk = inet_csk(sk); |
| struct sk_psock_link *link; |
| struct sk_psock *psock; |
| struct sock *osk; |
| int ret; |
| |
| WARN_ON_ONCE(!rcu_read_lock_held()); |
| if (unlikely(flags > BPF_EXIST)) |
| return -EINVAL; |
| if (unlikely(idx >= map->max_entries)) |
| return -E2BIG; |
| if (unlikely(rcu_access_pointer(icsk->icsk_ulp_data))) |
| return -EINVAL; |
| |
| link = sk_psock_init_link(); |
| if (!link) |
| return -ENOMEM; |
| |
| ret = sock_map_link(map, &stab->progs, sk); |
| if (ret < 0) |
| goto out_free; |
| |
| psock = sk_psock(sk); |
| WARN_ON_ONCE(!psock); |
| |
| raw_spin_lock_bh(&stab->lock); |
| osk = stab->sks[idx]; |
| if (osk && flags == BPF_NOEXIST) { |
| ret = -EEXIST; |
| goto out_unlock; |
| } else if (!osk && flags == BPF_EXIST) { |
| ret = -ENOENT; |
| goto out_unlock; |
| } |
| |
| sock_map_add_link(psock, link, map, &stab->sks[idx]); |
| stab->sks[idx] = sk; |
| if (osk) |
| sock_map_unref(osk, &stab->sks[idx]); |
| raw_spin_unlock_bh(&stab->lock); |
| return 0; |
| out_unlock: |
| raw_spin_unlock_bh(&stab->lock); |
| if (psock) |
| sk_psock_put(sk, psock); |
| out_free: |
| sk_psock_free_link(link); |
| return ret; |
| } |
| |
| static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops) |
| { |
| return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB || |
| ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB; |
| } |
| |
| static bool sock_map_sk_is_suitable(const struct sock *sk) |
| { |
| return sk->sk_type == SOCK_STREAM && |
| sk->sk_protocol == IPPROTO_TCP; |
| } |
| |
| static int sock_map_update_elem(struct bpf_map *map, void *key, |
| void *value, u64 flags) |
| { |
| u32 ufd = *(u32 *)value; |
| u32 idx = *(u32 *)key; |
| struct socket *sock; |
| struct sock *sk; |
| int ret; |
| |
| sock = sockfd_lookup(ufd, &ret); |
| if (!sock) |
| return ret; |
| sk = sock->sk; |
| if (!sk) { |
| ret = -EINVAL; |
| goto out; |
| } |
| if (!sock_map_sk_is_suitable(sk)) { |
| ret = -EOPNOTSUPP; |
| goto out; |
| } |
| |
| sock_map_sk_acquire(sk); |
| if (sk->sk_state != TCP_ESTABLISHED) |
| ret = -EOPNOTSUPP; |
| else |
| ret = sock_map_update_common(map, idx, sk, flags); |
| sock_map_sk_release(sk); |
| out: |
| fput(sock->file); |
| return ret; |
| } |
| |
| BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops, |
| struct bpf_map *, map, void *, key, u64, flags) |
| { |
| WARN_ON_ONCE(!rcu_read_lock_held()); |
| |
| if (likely(sock_map_sk_is_suitable(sops->sk) && |
| sock_map_op_okay(sops))) |
| return sock_map_update_common(map, *(u32 *)key, sops->sk, |
| flags); |
| return -EOPNOTSUPP; |
| } |
| |
| const struct bpf_func_proto bpf_sock_map_update_proto = { |
| .func = bpf_sock_map_update, |
| .gpl_only = false, |
| .pkt_access = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_CONST_MAP_PTR, |
| .arg3_type = ARG_PTR_TO_MAP_KEY, |
| .arg4_type = ARG_ANYTHING, |
| }; |
| |
| BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb, |
| struct bpf_map *, map, u32, key, u64, flags) |
| { |
| struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); |
| |
| if (unlikely(flags & ~(BPF_F_INGRESS))) |
| return SK_DROP; |
| tcb->bpf.flags = flags; |
| tcb->bpf.sk_redir = __sock_map_lookup_elem(map, key); |
| if (!tcb->bpf.sk_redir) |
| return SK_DROP; |
| return SK_PASS; |
| } |
| |
| const struct bpf_func_proto bpf_sk_redirect_map_proto = { |
| .func = bpf_sk_redirect_map, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_CONST_MAP_PTR, |
| .arg3_type = ARG_ANYTHING, |
| .arg4_type = ARG_ANYTHING, |
| }; |
| |
| BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg, |
| struct bpf_map *, map, u32, key, u64, flags) |
| { |
| if (unlikely(flags & ~(BPF_F_INGRESS))) |
| return SK_DROP; |
| msg->flags = flags; |
| msg->sk_redir = __sock_map_lookup_elem(map, key); |
| if (!msg->sk_redir) |
| return SK_DROP; |
| return SK_PASS; |
| } |
| |
| const struct bpf_func_proto bpf_msg_redirect_map_proto = { |
| .func = bpf_msg_redirect_map, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_CONST_MAP_PTR, |
| .arg3_type = ARG_ANYTHING, |
| .arg4_type = ARG_ANYTHING, |
| }; |
| |
| const struct bpf_map_ops sock_map_ops = { |
| .map_alloc = sock_map_alloc, |
| .map_free = sock_map_free, |
| .map_get_next_key = sock_map_get_next_key, |
| .map_update_elem = sock_map_update_elem, |
| .map_delete_elem = sock_map_delete_elem, |
| .map_lookup_elem = sock_map_lookup, |
| .map_release_uref = sock_map_release_progs, |
| .map_check_btf = map_check_no_btf, |
| }; |
| |
| struct bpf_htab_elem { |
| struct rcu_head rcu; |
| u32 hash; |
| struct sock *sk; |
| struct hlist_node node; |
| u8 key[0]; |
| }; |
| |
| struct bpf_htab_bucket { |
| struct hlist_head head; |
| raw_spinlock_t lock; |
| }; |
| |
| struct bpf_htab { |
| struct bpf_map map; |
| struct bpf_htab_bucket *buckets; |
| u32 buckets_num; |
| u32 elem_size; |
| struct sk_psock_progs progs; |
| atomic_t count; |
| }; |
| |
| static inline u32 sock_hash_bucket_hash(const void *key, u32 len) |
| { |
| return jhash(key, len, 0); |
| } |
| |
| static struct bpf_htab_bucket *sock_hash_select_bucket(struct bpf_htab *htab, |
| u32 hash) |
| { |
| return &htab->buckets[hash & (htab->buckets_num - 1)]; |
| } |
| |
| static struct bpf_htab_elem * |
| sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key, |
| u32 key_size) |
| { |
| struct bpf_htab_elem *elem; |
| |
| hlist_for_each_entry_rcu(elem, head, node) { |
| if (elem->hash == hash && |
| !memcmp(&elem->key, key, key_size)) |
| return elem; |
| } |
| |
| return NULL; |
| } |
| |
| static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key) |
| { |
| struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
| u32 key_size = map->key_size, hash; |
| struct bpf_htab_bucket *bucket; |
| struct bpf_htab_elem *elem; |
| |
| WARN_ON_ONCE(!rcu_read_lock_held()); |
| |
| hash = sock_hash_bucket_hash(key, key_size); |
| bucket = sock_hash_select_bucket(htab, hash); |
| elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); |
| |
| return elem ? elem->sk : NULL; |
| } |
| |
| static void sock_hash_free_elem(struct bpf_htab *htab, |
| struct bpf_htab_elem *elem) |
| { |
| atomic_dec(&htab->count); |
| kfree_rcu(elem, rcu); |
| } |
| |
| static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk, |
| void *link_raw) |
| { |
| struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
| struct bpf_htab_elem *elem_probe, *elem = link_raw; |
| struct bpf_htab_bucket *bucket; |
| |
| WARN_ON_ONCE(!rcu_read_lock_held()); |
| bucket = sock_hash_select_bucket(htab, elem->hash); |
| |
| /* elem may be deleted in parallel from the map, but access here |
| * is okay since it's going away only after RCU grace period. |
| * However, we need to check whether it's still present. |
| */ |
| raw_spin_lock_bh(&bucket->lock); |
| elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash, |
| elem->key, map->key_size); |
| if (elem_probe && elem_probe == elem) { |
| hlist_del_rcu(&elem->node); |
| sock_map_unref(elem->sk, elem); |
| sock_hash_free_elem(htab, elem); |
| } |
| raw_spin_unlock_bh(&bucket->lock); |
| } |
| |
| static int sock_hash_delete_elem(struct bpf_map *map, void *key) |
| { |
| struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
| u32 hash, key_size = map->key_size; |
| struct bpf_htab_bucket *bucket; |
| struct bpf_htab_elem *elem; |
| int ret = -ENOENT; |
| |
| hash = sock_hash_bucket_hash(key, key_size); |
| bucket = sock_hash_select_bucket(htab, hash); |
| |
| raw_spin_lock_bh(&bucket->lock); |
| elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); |
| if (elem) { |
| hlist_del_rcu(&elem->node); |
| sock_map_unref(elem->sk, elem); |
| sock_hash_free_elem(htab, elem); |
| ret = 0; |
| } |
| raw_spin_unlock_bh(&bucket->lock); |
| return ret; |
| } |
| |
| static struct bpf_htab_elem *sock_hash_alloc_elem(struct bpf_htab *htab, |
| void *key, u32 key_size, |
| u32 hash, struct sock *sk, |
| struct bpf_htab_elem *old) |
| { |
| struct bpf_htab_elem *new; |
| |
| if (atomic_inc_return(&htab->count) > htab->map.max_entries) { |
| if (!old) { |
| atomic_dec(&htab->count); |
| return ERR_PTR(-E2BIG); |
| } |
| } |
| |
| new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN, |
| htab->map.numa_node); |
| if (!new) { |
| atomic_dec(&htab->count); |
| return ERR_PTR(-ENOMEM); |
| } |
| memcpy(new->key, key, key_size); |
| new->sk = sk; |
| new->hash = hash; |
| return new; |
| } |
| |
| static int sock_hash_update_common(struct bpf_map *map, void *key, |
| struct sock *sk, u64 flags) |
| { |
| struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
| struct inet_connection_sock *icsk = inet_csk(sk); |
| u32 key_size = map->key_size, hash; |
| struct bpf_htab_elem *elem, *elem_new; |
| struct bpf_htab_bucket *bucket; |
| struct sk_psock_link *link; |
| struct sk_psock *psock; |
| int ret; |
| |
| WARN_ON_ONCE(!rcu_read_lock_held()); |
| if (unlikely(flags > BPF_EXIST)) |
| return -EINVAL; |
| if (unlikely(icsk->icsk_ulp_data)) |
| return -EINVAL; |
| |
| link = sk_psock_init_link(); |
| if (!link) |
| return -ENOMEM; |
| |
| ret = sock_map_link(map, &htab->progs, sk); |
| if (ret < 0) |
| goto out_free; |
| |
| psock = sk_psock(sk); |
| WARN_ON_ONCE(!psock); |
| |
| hash = sock_hash_bucket_hash(key, key_size); |
| bucket = sock_hash_select_bucket(htab, hash); |
| |
| raw_spin_lock_bh(&bucket->lock); |
| elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); |
| if (elem && flags == BPF_NOEXIST) { |
| ret = -EEXIST; |
| goto out_unlock; |
| } else if (!elem && flags == BPF_EXIST) { |
| ret = -ENOENT; |
| goto out_unlock; |
| } |
| |
| elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem); |
| if (IS_ERR(elem_new)) { |
| ret = PTR_ERR(elem_new); |
| goto out_unlock; |
| } |
| |
| sock_map_add_link(psock, link, map, elem_new); |
| /* Add new element to the head of the list, so that |
| * concurrent search will find it before old elem. |
| */ |
| hlist_add_head_rcu(&elem_new->node, &bucket->head); |
| if (elem) { |
| hlist_del_rcu(&elem->node); |
| sock_map_unref(elem->sk, elem); |
| sock_hash_free_elem(htab, elem); |
| } |
| raw_spin_unlock_bh(&bucket->lock); |
| return 0; |
| out_unlock: |
| raw_spin_unlock_bh(&bucket->lock); |
| sk_psock_put(sk, psock); |
| out_free: |
| sk_psock_free_link(link); |
| return ret; |
| } |
| |
| static int sock_hash_update_elem(struct bpf_map *map, void *key, |
| void *value, u64 flags) |
| { |
| u32 ufd = *(u32 *)value; |
| struct socket *sock; |
| struct sock *sk; |
| int ret; |
| |
| sock = sockfd_lookup(ufd, &ret); |
| if (!sock) |
| return ret; |
| sk = sock->sk; |
| if (!sk) { |
| ret = -EINVAL; |
| goto out; |
| } |
| if (!sock_map_sk_is_suitable(sk)) { |
| ret = -EOPNOTSUPP; |
| goto out; |
| } |
| |
| sock_map_sk_acquire(sk); |
| if (sk->sk_state != TCP_ESTABLISHED) |
| ret = -EOPNOTSUPP; |
| else |
| ret = sock_hash_update_common(map, key, sk, flags); |
| sock_map_sk_release(sk); |
| out: |
| fput(sock->file); |
| return ret; |
| } |
| |
| static int sock_hash_get_next_key(struct bpf_map *map, void *key, |
| void *key_next) |
| { |
| struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
| struct bpf_htab_elem *elem, *elem_next; |
| u32 hash, key_size = map->key_size; |
| struct hlist_head *head; |
| int i = 0; |
| |
| if (!key) |
| goto find_first_elem; |
| hash = sock_hash_bucket_hash(key, key_size); |
| head = &sock_hash_select_bucket(htab, hash)->head; |
| elem = sock_hash_lookup_elem_raw(head, hash, key, key_size); |
| if (!elem) |
| goto find_first_elem; |
| |
| elem_next = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu(&elem->node)), |
| struct bpf_htab_elem, node); |
| if (elem_next) { |
| memcpy(key_next, elem_next->key, key_size); |
| return 0; |
| } |
| |
| i = hash & (htab->buckets_num - 1); |
| i++; |
| find_first_elem: |
| for (; i < htab->buckets_num; i++) { |
| head = &sock_hash_select_bucket(htab, i)->head; |
| elem_next = hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(head)), |
| struct bpf_htab_elem, node); |
| if (elem_next) { |
| memcpy(key_next, elem_next->key, key_size); |
| return 0; |
| } |
| } |
| |
| return -ENOENT; |
| } |
| |
| static struct bpf_map *sock_hash_alloc(union bpf_attr *attr) |
| { |
| struct bpf_htab *htab; |
| int i, err; |
| u64 cost; |
| |
| if (!capable(CAP_NET_ADMIN)) |
| return ERR_PTR(-EPERM); |
| if (attr->max_entries == 0 || |
| attr->key_size == 0 || |
| attr->value_size != 4 || |
| attr->map_flags & ~SOCK_CREATE_FLAG_MASK) |
| return ERR_PTR(-EINVAL); |
| if (attr->key_size > MAX_BPF_STACK) |
| return ERR_PTR(-E2BIG); |
| |
| htab = kzalloc(sizeof(*htab), GFP_USER); |
| if (!htab) |
| return ERR_PTR(-ENOMEM); |
| |
| bpf_map_init_from_attr(&htab->map, attr); |
| |
| htab->buckets_num = roundup_pow_of_two(htab->map.max_entries); |
| htab->elem_size = sizeof(struct bpf_htab_elem) + |
| round_up(htab->map.key_size, 8); |
| if (htab->buckets_num == 0 || |
| htab->buckets_num > U32_MAX / sizeof(struct bpf_htab_bucket)) { |
| err = -EINVAL; |
| goto free_htab; |
| } |
| |
| cost = (u64) htab->buckets_num * sizeof(struct bpf_htab_bucket) + |
| (u64) htab->elem_size * htab->map.max_entries; |
| if (cost >= U32_MAX - PAGE_SIZE) { |
| err = -EINVAL; |
| goto free_htab; |
| } |
| |
| htab->buckets = bpf_map_area_alloc(htab->buckets_num * |
| sizeof(struct bpf_htab_bucket), |
| htab->map.numa_node); |
| if (!htab->buckets) { |
| err = -ENOMEM; |
| goto free_htab; |
| } |
| |
| for (i = 0; i < htab->buckets_num; i++) { |
| INIT_HLIST_HEAD(&htab->buckets[i].head); |
| raw_spin_lock_init(&htab->buckets[i].lock); |
| } |
| |
| return &htab->map; |
| free_htab: |
| kfree(htab); |
| return ERR_PTR(err); |
| } |
| |
| static void sock_hash_free(struct bpf_map *map) |
| { |
| struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
| struct bpf_htab_bucket *bucket; |
| struct bpf_htab_elem *elem; |
| struct hlist_node *node; |
| int i; |
| |
| /* After the sync no updates or deletes will be in-flight so it |
| * is safe to walk map and remove entries without risking a race |
| * in EEXIST update case. |
| */ |
| synchronize_rcu(); |
| for (i = 0; i < htab->buckets_num; i++) { |
| bucket = sock_hash_select_bucket(htab, i); |
| hlist_for_each_entry_safe(elem, node, &bucket->head, node) { |
| hlist_del_rcu(&elem->node); |
| lock_sock(elem->sk); |
| rcu_read_lock(); |
| sock_map_unref(elem->sk, elem); |
| rcu_read_unlock(); |
| release_sock(elem->sk); |
| } |
| } |
| |
| /* wait for psock readers accessing its map link */ |
| synchronize_rcu(); |
| |
| bpf_map_area_free(htab->buckets); |
| kfree(htab); |
| } |
| |
| static void sock_hash_release_progs(struct bpf_map *map) |
| { |
| psock_progs_drop(&container_of(map, struct bpf_htab, map)->progs); |
| } |
| |
| BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops, |
| struct bpf_map *, map, void *, key, u64, flags) |
| { |
| WARN_ON_ONCE(!rcu_read_lock_held()); |
| |
| if (likely(sock_map_sk_is_suitable(sops->sk) && |
| sock_map_op_okay(sops))) |
| return sock_hash_update_common(map, key, sops->sk, flags); |
| return -EOPNOTSUPP; |
| } |
| |
| const struct bpf_func_proto bpf_sock_hash_update_proto = { |
| .func = bpf_sock_hash_update, |
| .gpl_only = false, |
| .pkt_access = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_CONST_MAP_PTR, |
| .arg3_type = ARG_PTR_TO_MAP_KEY, |
| .arg4_type = ARG_ANYTHING, |
| }; |
| |
| BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb, |
| struct bpf_map *, map, void *, key, u64, flags) |
| { |
| struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); |
| |
| if (unlikely(flags & ~(BPF_F_INGRESS))) |
| return SK_DROP; |
| tcb->bpf.flags = flags; |
| tcb->bpf.sk_redir = __sock_hash_lookup_elem(map, key); |
| if (!tcb->bpf.sk_redir) |
| return SK_DROP; |
| return SK_PASS; |
| } |
| |
| const struct bpf_func_proto bpf_sk_redirect_hash_proto = { |
| .func = bpf_sk_redirect_hash, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_CONST_MAP_PTR, |
| .arg3_type = ARG_PTR_TO_MAP_KEY, |
| .arg4_type = ARG_ANYTHING, |
| }; |
| |
| BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg, |
| struct bpf_map *, map, void *, key, u64, flags) |
| { |
| if (unlikely(flags & ~(BPF_F_INGRESS))) |
| return SK_DROP; |
| msg->flags = flags; |
| msg->sk_redir = __sock_hash_lookup_elem(map, key); |
| if (!msg->sk_redir) |
| return SK_DROP; |
| return SK_PASS; |
| } |
| |
| const struct bpf_func_proto bpf_msg_redirect_hash_proto = { |
| .func = bpf_msg_redirect_hash, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_CONST_MAP_PTR, |
| .arg3_type = ARG_PTR_TO_MAP_KEY, |
| .arg4_type = ARG_ANYTHING, |
| }; |
| |
| const struct bpf_map_ops sock_hash_ops = { |
| .map_alloc = sock_hash_alloc, |
| .map_free = sock_hash_free, |
| .map_get_next_key = sock_hash_get_next_key, |
| .map_update_elem = sock_hash_update_elem, |
| .map_delete_elem = sock_hash_delete_elem, |
| .map_lookup_elem = sock_map_lookup, |
| .map_release_uref = sock_hash_release_progs, |
| .map_check_btf = map_check_no_btf, |
| }; |
| |
| static struct sk_psock_progs *sock_map_progs(struct bpf_map *map) |
| { |
| switch (map->map_type) { |
| case BPF_MAP_TYPE_SOCKMAP: |
| return &container_of(map, struct bpf_stab, map)->progs; |
| case BPF_MAP_TYPE_SOCKHASH: |
| return &container_of(map, struct bpf_htab, map)->progs; |
| default: |
| break; |
| } |
| |
| return NULL; |
| } |
| |
| int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, |
| u32 which) |
| { |
| struct sk_psock_progs *progs = sock_map_progs(map); |
| |
| if (!progs) |
| return -EOPNOTSUPP; |
| |
| switch (which) { |
| case BPF_SK_MSG_VERDICT: |
| psock_set_prog(&progs->msg_parser, prog); |
| break; |
| case BPF_SK_SKB_STREAM_PARSER: |
| psock_set_prog(&progs->skb_parser, prog); |
| break; |
| case BPF_SK_SKB_STREAM_VERDICT: |
| psock_set_prog(&progs->skb_verdict, prog); |
| break; |
| default: |
| return -EOPNOTSUPP; |
| } |
| |
| return 0; |
| } |
| |
| void sk_psock_unlink(struct sock *sk, struct sk_psock_link *link) |
| { |
| switch (link->map->map_type) { |
| case BPF_MAP_TYPE_SOCKMAP: |
| return sock_map_delete_from_link(link->map, sk, |
| link->link_raw); |
| case BPF_MAP_TYPE_SOCKHASH: |
| return sock_hash_delete_from_link(link->map, sk, |
| link->link_raw); |
| default: |
| break; |
| } |
| } |