diff options
Diffstat (limited to 'net/core/sock_map.c')
| -rw-r--r-- | net/core/sock_map.c | 1002 |
1 files changed, 1002 insertions, 0 deletions
diff --git a/net/core/sock_map.c b/net/core/sock_map.c new file mode 100644 index 000000000000..3c0e44cb811a --- /dev/null +++ b/net/core/sock_map.c @@ -0,0 +1,1002 @@ +// 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 *); + if (cost >= U32_MAX - PAGE_SIZE) { + err = -EINVAL; + goto free_stab; + } + + stab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT; + err = bpf_map_precharge_memlock(stab->map.pages); + 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; +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(sk); + if (psock) { + if (!sk_has_psock(sk)) { + ret = -EBUSY; + goto out_progs; + } + 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; + + synchronize_rcu(); + rcu_read_lock(); + raw_spin_lock_bh(&stab->lock); + for (i = 0; i < stab->map.max_entries; i++) { + struct sock **psk = &stab->sks[i]; + struct sock *sk; + + sk = xchg(psk, NULL); + if (sk) + sock_map_unref(sk, psk); + } + raw_spin_unlock_bh(&stab->lock); + rcu_read_unlock(); + + 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; + + raw_spin_lock_bh(&stab->lock); + sk = *psk; + if (!sk_test || sk_test == sk) + *psk = NULL; + raw_spin_unlock_bh(&stab->lock); + if (unlikely(!sk)) + return -EINVAL; + sock_map_unref(sk, psk); + return 0; +} + +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 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; + + 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) || + sk->sk_state != TCP_ESTABLISHED) { + ret = -EOPNOTSUPP; + goto out; + } + + sock_map_sk_acquire(sk); + 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); + 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; + + 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) || + sk->sk_state != TCP_ESTABLISHED) { + ret = -EOPNOTSUPP; + goto out; + } + + sock_map_sk_acquire(sk); + 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; + + synchronize_rcu(); + rcu_read_lock(); + for (i = 0; i < htab->buckets_num; i++) { + bucket = sock_hash_select_bucket(htab, i); + raw_spin_lock_bh(&bucket->lock); + hlist_for_each_entry_safe(elem, node, &bucket->head, node) { + hlist_del_rcu(&elem->node); + sock_map_unref(elem->sk, elem); + } + raw_spin_unlock_bh(&bucket->lock); + } + rcu_read_unlock(); + + 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; + } +} |
