diff options
Diffstat (limited to 'net/core/sock_map.c')
| -rw-r--r-- | net/core/sock_map.c | 1701 |
1 files changed, 1701 insertions, 0 deletions
diff --git a/net/core/sock_map.c b/net/core/sock_map.c new file mode 100644 index 000000000..91140bc05 --- /dev/null +++ b/net/core/sock_map.c @@ -0,0 +1,1701 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */ + +#include <linux/bpf.h> +#include <linux/btf_ids.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> +#include <linux/sock_diag.h> +#include <net/udp.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 int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, + struct bpf_prog *old, u32 which); +static struct sk_psock_progs *sock_map_progs(struct bpf_map *map); + +static struct bpf_map *sock_map_alloc(union bpf_attr *attr) +{ + struct bpf_stab *stab; + + if (!capable(CAP_NET_ADMIN)) + return ERR_PTR(-EPERM); + if (attr->max_entries == 0 || + attr->key_size != 4 || + (attr->value_size != sizeof(u32) && + attr->value_size != sizeof(u64)) || + attr->map_flags & ~SOCK_CREATE_FLAG_MASK) + return ERR_PTR(-EINVAL); + + stab = bpf_map_area_alloc(sizeof(*stab), NUMA_NO_NODE); + if (!stab) + return ERR_PTR(-ENOMEM); + + bpf_map_init_from_attr(&stab->map, attr); + raw_spin_lock_init(&stab->lock); + + stab->sks = bpf_map_area_alloc((u64) stab->map.max_entries * + sizeof(struct sock *), + stab->map.numa_node); + if (!stab->sks) { + bpf_map_area_free(stab); + return ERR_PTR(-ENOMEM); + } + + return &stab->map; +} + +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; + + if (attr->attach_flags || attr->replace_bpf_fd) + return -EINVAL; + + f = fdget(ufd); + map = __bpf_map_get(f); + if (IS_ERR(map)) + return PTR_ERR(map); + ret = sock_map_prog_update(map, prog, NULL, attr->attach_type); + fdput(f); + return ret; +} + +int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype) +{ + u32 ufd = attr->target_fd; + struct bpf_prog *prog; + struct bpf_map *map; + struct fd f; + int ret; + + if (attr->attach_flags || attr->replace_bpf_fd) + return -EINVAL; + + f = fdget(ufd); + map = __bpf_map_get(f); + if (IS_ERR(map)) + return PTR_ERR(map); + + prog = bpf_prog_get(attr->attach_bpf_fd); + if (IS_ERR(prog)) { + ret = PTR_ERR(prog); + goto put_map; + } + + if (prog->type != ptype) { + ret = -EINVAL; + goto put_prog; + } + + ret = sock_map_prog_update(map, NULL, prog, attr->attach_type); +put_prog: + bpf_prog_put(prog); +put_map: + fdput(f); + return ret; +} + +static void sock_map_sk_acquire(struct sock *sk) + __acquires(&sk->sk_lock.slock) +{ + lock_sock(sk); + rcu_read_lock(); +} + +static void sock_map_sk_release(struct sock *sk) + __releases(&sk->sk_lock.slock) +{ + rcu_read_unlock(); + 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) +{ + bool strp_stop = false, verdict_stop = false; + struct sk_psock_link *link, *tmp; + + 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 sk_psock_progs *progs = sock_map_progs(map); + + if (psock->saved_data_ready && progs->stream_parser) + strp_stop = true; + if (psock->saved_data_ready && progs->stream_verdict) + verdict_stop = true; + if (psock->saved_data_ready && progs->skb_verdict) + verdict_stop = true; + list_del(&link->list); + sk_psock_free_link(link); + } + } + spin_unlock_bh(&psock->link_lock); + if (strp_stop || verdict_stop) { + write_lock_bh(&sk->sk_callback_lock); + if (strp_stop) + sk_psock_stop_strp(sk, psock); + if (verdict_stop) + sk_psock_stop_verdict(sk, psock); + + if (psock->psock_update_sk_prot) + psock->psock_update_sk_prot(sk, psock, false); + 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_init_proto(struct sock *sk, struct sk_psock *psock) +{ + if (!sk->sk_prot->psock_update_sk_prot) + return -EINVAL; + psock->psock_update_sk_prot = sk->sk_prot->psock_update_sk_prot; + return sk->sk_prot->psock_update_sk_prot(sk, psock, false); +} + +static struct sk_psock *sock_map_psock_get_checked(struct sock *sk) +{ + struct sk_psock *psock; + + rcu_read_lock(); + psock = sk_psock(sk); + if (psock) { + if (sk->sk_prot->close != sock_map_close) { + psock = ERR_PTR(-EBUSY); + goto out; + } + + if (!refcount_inc_not_zero(&psock->refcnt)) + psock = ERR_PTR(-EBUSY); + } +out: + rcu_read_unlock(); + return psock; +} + +static int sock_map_link(struct bpf_map *map, struct sock *sk) +{ + struct sk_psock_progs *progs = sock_map_progs(map); + struct bpf_prog *stream_verdict = NULL; + struct bpf_prog *stream_parser = NULL; + struct bpf_prog *skb_verdict = NULL; + struct bpf_prog *msg_parser = NULL; + struct sk_psock *psock; + int ret; + + stream_verdict = READ_ONCE(progs->stream_verdict); + if (stream_verdict) { + stream_verdict = bpf_prog_inc_not_zero(stream_verdict); + if (IS_ERR(stream_verdict)) + return PTR_ERR(stream_verdict); + } + + stream_parser = READ_ONCE(progs->stream_parser); + if (stream_parser) { + stream_parser = bpf_prog_inc_not_zero(stream_parser); + if (IS_ERR(stream_parser)) { + ret = PTR_ERR(stream_parser); + goto out_put_stream_verdict; + } + } + + 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_put_stream_parser; + } + } + + skb_verdict = READ_ONCE(progs->skb_verdict); + if (skb_verdict) { + skb_verdict = bpf_prog_inc_not_zero(skb_verdict); + if (IS_ERR(skb_verdict)) { + ret = PTR_ERR(skb_verdict); + goto out_put_msg_parser; + } + } + + psock = sock_map_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)) || + (stream_parser && READ_ONCE(psock->progs.stream_parser)) || + (skb_verdict && READ_ONCE(psock->progs.skb_verdict)) || + (skb_verdict && READ_ONCE(psock->progs.stream_verdict)) || + (stream_verdict && READ_ONCE(psock->progs.skb_verdict)) || + (stream_verdict && READ_ONCE(psock->progs.stream_verdict))) { + sk_psock_put(sk, psock); + ret = -EBUSY; + goto out_progs; + } + } else { + psock = sk_psock_init(sk, map->numa_node); + if (IS_ERR(psock)) { + ret = PTR_ERR(psock); + goto out_progs; + } + } + + if (msg_parser) + psock_set_prog(&psock->progs.msg_parser, msg_parser); + if (stream_parser) + psock_set_prog(&psock->progs.stream_parser, stream_parser); + if (stream_verdict) + psock_set_prog(&psock->progs.stream_verdict, stream_verdict); + if (skb_verdict) + psock_set_prog(&psock->progs.skb_verdict, skb_verdict); + + /* msg_* and stream_* programs references tracked in psock after this + * point. Reference dec and cleanup will occur through psock destructor + */ + ret = sock_map_init_proto(sk, psock); + if (ret < 0) { + sk_psock_put(sk, psock); + goto out; + } + + write_lock_bh(&sk->sk_callback_lock); + if (stream_parser && stream_verdict && !psock->saved_data_ready) { + ret = sk_psock_init_strp(sk, psock); + if (ret) { + write_unlock_bh(&sk->sk_callback_lock); + sk_psock_put(sk, psock); + goto out; + } + sk_psock_start_strp(sk, psock); + } else if (!stream_parser && stream_verdict && !psock->saved_data_ready) { + sk_psock_start_verdict(sk,psock); + } else if (!stream_verdict && skb_verdict && !psock->saved_data_ready) { + sk_psock_start_verdict(sk, psock); + } + write_unlock_bh(&sk->sk_callback_lock); + return 0; +out_progs: + if (skb_verdict) + bpf_prog_put(skb_verdict); +out_put_msg_parser: + if (msg_parser) + bpf_prog_put(msg_parser); +out_put_stream_parser: + if (stream_parser) + bpf_prog_put(stream_parser); +out_put_stream_verdict: + if (stream_verdict) + bpf_prog_put(stream_verdict); +out: + 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) { + sock_hold(sk); + lock_sock(sk); + rcu_read_lock(); + sock_map_unref(sk, psk); + rcu_read_unlock(); + release_sock(sk); + sock_put(sk); + } + } + + /* wait for psock readers accessing its map link */ + synchronize_rcu(); + + bpf_map_area_free(stab->sks); + bpf_map_area_free(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) +{ + struct sock *sk; + + sk = __sock_map_lookup_elem(map, *(u32 *)key); + if (!sk) + return NULL; + if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt)) + return NULL; + return sk; +} + +static void *sock_map_lookup_sys(struct bpf_map *map, void *key) +{ + struct sock *sk; + + if (map->value_size != sizeof(u64)) + return ERR_PTR(-ENOSPC); + + sk = __sock_map_lookup_elem(map, *(u32 *)key); + if (!sk) + return ERR_PTR(-ENOENT); + + __sock_gen_cookie(sk); + return &sk->sk_cookie; +} + +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 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, 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 || + ops->op == BPF_SOCK_OPS_TCP_LISTEN_CB; +} + +static bool sock_map_redirect_allowed(const struct sock *sk) +{ + if (sk_is_tcp(sk)) + return sk->sk_state != TCP_LISTEN; + else + return sk->sk_state == TCP_ESTABLISHED; +} + +static bool sock_map_sk_is_suitable(const struct sock *sk) +{ + return !!sk->sk_prot->psock_update_sk_prot; +} + +static bool sock_map_sk_state_allowed(const struct sock *sk) +{ + if (sk_is_tcp(sk)) + return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_LISTEN); + if (sk_is_stream_unix(sk)) + return (1 << sk->sk_state) & TCPF_ESTABLISHED; + return true; +} + +static int sock_hash_update_common(struct bpf_map *map, void *key, + struct sock *sk, u64 flags); + +int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value, + u64 flags) +{ + struct socket *sock; + struct sock *sk; + int ret; + u64 ufd; + + if (map->value_size == sizeof(u64)) + ufd = *(u64 *)value; + else + ufd = *(u32 *)value; + if (ufd > S32_MAX) + return -EINVAL; + + 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 (!sock_map_sk_state_allowed(sk)) + ret = -EOPNOTSUPP; + else if (map->map_type == BPF_MAP_TYPE_SOCKMAP) + ret = sock_map_update_common(map, *(u32 *)key, sk, flags); + else + ret = sock_hash_update_common(map, key, sk, flags); + sock_map_sk_release(sk); +out: + sockfd_put(sock); + return ret; +} + +static int sock_map_update_elem(struct bpf_map *map, void *key, + void *value, u64 flags) +{ + struct sock *sk = (struct sock *)value; + int ret; + + if (unlikely(!sk || !sk_fullsock(sk))) + return -EINVAL; + + if (!sock_map_sk_is_suitable(sk)) + return -EOPNOTSUPP; + + local_bh_disable(); + bh_lock_sock(sk); + if (!sock_map_sk_state_allowed(sk)) + ret = -EOPNOTSUPP; + else if (map->map_type == BPF_MAP_TYPE_SOCKMAP) + ret = sock_map_update_common(map, *(u32 *)key, sk, flags); + else + ret = sock_hash_update_common(map, key, sk, flags); + bh_unlock_sock(sk); + local_bh_enable(); + 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 sock *sk; + + if (unlikely(flags & ~(BPF_F_INGRESS))) + return SK_DROP; + + sk = __sock_map_lookup_elem(map, key); + if (unlikely(!sk || !sock_map_redirect_allowed(sk))) + return SK_DROP; + + skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS); + 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) +{ + struct sock *sk; + + if (unlikely(flags & ~(BPF_F_INGRESS))) + return SK_DROP; + + sk = __sock_map_lookup_elem(map, key); + if (unlikely(!sk || !sock_map_redirect_allowed(sk))) + return SK_DROP; + if (!(flags & BPF_F_INGRESS) && !sk_is_tcp(sk)) + return SK_DROP; + + msg->flags = flags; + msg->sk_redir = sk; + 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, +}; + +struct sock_map_seq_info { + struct bpf_map *map; + struct sock *sk; + u32 index; +}; + +struct bpf_iter__sockmap { + __bpf_md_ptr(struct bpf_iter_meta *, meta); + __bpf_md_ptr(struct bpf_map *, map); + __bpf_md_ptr(void *, key); + __bpf_md_ptr(struct sock *, sk); +}; + +DEFINE_BPF_ITER_FUNC(sockmap, struct bpf_iter_meta *meta, + struct bpf_map *map, void *key, + struct sock *sk) + +static void *sock_map_seq_lookup_elem(struct sock_map_seq_info *info) +{ + if (unlikely(info->index >= info->map->max_entries)) + return NULL; + + info->sk = __sock_map_lookup_elem(info->map, info->index); + + /* can't return sk directly, since that might be NULL */ + return info; +} + +static void *sock_map_seq_start(struct seq_file *seq, loff_t *pos) + __acquires(rcu) +{ + struct sock_map_seq_info *info = seq->private; + + if (*pos == 0) + ++*pos; + + /* pairs with sock_map_seq_stop */ + rcu_read_lock(); + return sock_map_seq_lookup_elem(info); +} + +static void *sock_map_seq_next(struct seq_file *seq, void *v, loff_t *pos) + __must_hold(rcu) +{ + struct sock_map_seq_info *info = seq->private; + + ++*pos; + ++info->index; + + return sock_map_seq_lookup_elem(info); +} + +static int sock_map_seq_show(struct seq_file *seq, void *v) + __must_hold(rcu) +{ + struct sock_map_seq_info *info = seq->private; + struct bpf_iter__sockmap ctx = {}; + struct bpf_iter_meta meta; + struct bpf_prog *prog; + + meta.seq = seq; + prog = bpf_iter_get_info(&meta, !v); + if (!prog) + return 0; + + ctx.meta = &meta; + ctx.map = info->map; + if (v) { + ctx.key = &info->index; + ctx.sk = info->sk; + } + + return bpf_iter_run_prog(prog, &ctx); +} + +static void sock_map_seq_stop(struct seq_file *seq, void *v) + __releases(rcu) +{ + if (!v) + (void)sock_map_seq_show(seq, NULL); + + /* pairs with sock_map_seq_start */ + rcu_read_unlock(); +} + +static const struct seq_operations sock_map_seq_ops = { + .start = sock_map_seq_start, + .next = sock_map_seq_next, + .stop = sock_map_seq_stop, + .show = sock_map_seq_show, +}; + +static int sock_map_init_seq_private(void *priv_data, + struct bpf_iter_aux_info *aux) +{ + struct sock_map_seq_info *info = priv_data; + + bpf_map_inc_with_uref(aux->map); + info->map = aux->map; + return 0; +} + +static void sock_map_fini_seq_private(void *priv_data) +{ + struct sock_map_seq_info *info = priv_data; + + bpf_map_put_with_uref(info->map); +} + +static const struct bpf_iter_seq_info sock_map_iter_seq_info = { + .seq_ops = &sock_map_seq_ops, + .init_seq_private = sock_map_init_seq_private, + .fini_seq_private = sock_map_fini_seq_private, + .seq_priv_size = sizeof(struct sock_map_seq_info), +}; + +BTF_ID_LIST_SINGLE(sock_map_btf_ids, struct, bpf_stab) +const struct bpf_map_ops sock_map_ops = { + .map_meta_equal = bpf_map_meta_equal, + .map_alloc = sock_map_alloc, + .map_free = sock_map_free, + .map_get_next_key = sock_map_get_next_key, + .map_lookup_elem_sys_only = sock_map_lookup_sys, + .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, + .map_btf_id = &sock_map_btf_ids[0], + .iter_seq_info = &sock_map_iter_seq_info, +}; + +struct bpf_shtab_elem { + struct rcu_head rcu; + u32 hash; + struct sock *sk; + struct hlist_node node; + u8 key[]; +}; + +struct bpf_shtab_bucket { + struct hlist_head head; + raw_spinlock_t lock; +}; + +struct bpf_shtab { + struct bpf_map map; + struct bpf_shtab_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_shtab_bucket *sock_hash_select_bucket(struct bpf_shtab *htab, + u32 hash) +{ + return &htab->buckets[hash & (htab->buckets_num - 1)]; +} + +static struct bpf_shtab_elem * +sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key, + u32 key_size) +{ + struct bpf_shtab_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_shtab *htab = container_of(map, struct bpf_shtab, map); + u32 key_size = map->key_size, hash; + struct bpf_shtab_bucket *bucket; + struct bpf_shtab_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_shtab *htab, + struct bpf_shtab_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_shtab *htab = container_of(map, struct bpf_shtab, map); + struct bpf_shtab_elem *elem_probe, *elem = link_raw; + struct bpf_shtab_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_shtab *htab = container_of(map, struct bpf_shtab, map); + u32 hash, key_size = map->key_size; + struct bpf_shtab_bucket *bucket; + struct bpf_shtab_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_shtab_elem *sock_hash_alloc_elem(struct bpf_shtab *htab, + void *key, u32 key_size, + u32 hash, struct sock *sk, + struct bpf_shtab_elem *old) +{ + struct bpf_shtab_elem *new; + + if (atomic_inc_return(&htab->count) > htab->map.max_entries) { + if (!old) { + atomic_dec(&htab->count); + return ERR_PTR(-E2BIG); + } + } + + new = bpf_map_kmalloc_node(&htab->map, 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_shtab *htab = container_of(map, struct bpf_shtab, map); + u32 key_size = map->key_size, hash; + struct bpf_shtab_elem *elem, *elem_new; + struct bpf_shtab_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, 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_get_next_key(struct bpf_map *map, void *key, + void *key_next) +{ + struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); + struct bpf_shtab_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(hlist_next_rcu(&elem->node)), + struct bpf_shtab_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(hlist_first_rcu(head)), + struct bpf_shtab_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_shtab *htab; + int i, err; + + if (!capable(CAP_NET_ADMIN)) + return ERR_PTR(-EPERM); + if (attr->max_entries == 0 || + attr->key_size == 0 || + (attr->value_size != sizeof(u32) && + attr->value_size != sizeof(u64)) || + attr->map_flags & ~SOCK_CREATE_FLAG_MASK) + return ERR_PTR(-EINVAL); + if (attr->key_size > MAX_BPF_STACK) + return ERR_PTR(-E2BIG); + + htab = bpf_map_area_alloc(sizeof(*htab), NUMA_NO_NODE); + 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_shtab_elem) + + round_up(htab->map.key_size, 8); + if (htab->buckets_num == 0 || + htab->buckets_num > U32_MAX / sizeof(struct bpf_shtab_bucket)) { + err = -EINVAL; + goto free_htab; + } + + htab->buckets = bpf_map_area_alloc(htab->buckets_num * + sizeof(struct bpf_shtab_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: + bpf_map_area_free(htab); + return ERR_PTR(err); +} + +static void sock_hash_free(struct bpf_map *map) +{ + struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); + struct bpf_shtab_bucket *bucket; + struct hlist_head unlink_list; + struct bpf_shtab_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); + + /* We are racing with sock_hash_delete_from_link to + * enter the spin-lock critical section. Every socket on + * the list is still linked to sockhash. Since link + * exists, psock exists and holds a ref to socket. That + * lets us to grab a socket ref too. + */ + raw_spin_lock_bh(&bucket->lock); + hlist_for_each_entry(elem, &bucket->head, node) + sock_hold(elem->sk); + hlist_move_list(&bucket->head, &unlink_list); + raw_spin_unlock_bh(&bucket->lock); + + /* Process removed entries out of atomic context to + * block for socket lock before deleting the psock's + * link to sockhash. + */ + hlist_for_each_entry_safe(elem, node, &unlink_list, node) { + hlist_del(&elem->node); + lock_sock(elem->sk); + rcu_read_lock(); + sock_map_unref(elem->sk, elem); + rcu_read_unlock(); + release_sock(elem->sk); + sock_put(elem->sk); + sock_hash_free_elem(htab, elem); + } + } + + /* wait for psock readers accessing its map link */ + synchronize_rcu(); + + bpf_map_area_free(htab->buckets); + bpf_map_area_free(htab); +} + +static void *sock_hash_lookup_sys(struct bpf_map *map, void *key) +{ + struct sock *sk; + + if (map->value_size != sizeof(u64)) + return ERR_PTR(-ENOSPC); + + sk = __sock_hash_lookup_elem(map, key); + if (!sk) + return ERR_PTR(-ENOENT); + + __sock_gen_cookie(sk); + return &sk->sk_cookie; +} + +static void *sock_hash_lookup(struct bpf_map *map, void *key) +{ + struct sock *sk; + + sk = __sock_hash_lookup_elem(map, key); + if (!sk) + return NULL; + if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt)) + return NULL; + return sk; +} + +static void sock_hash_release_progs(struct bpf_map *map) +{ + psock_progs_drop(&container_of(map, struct bpf_shtab, 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 sock *sk; + + if (unlikely(flags & ~(BPF_F_INGRESS))) + return SK_DROP; + + sk = __sock_hash_lookup_elem(map, key); + if (unlikely(!sk || !sock_map_redirect_allowed(sk))) + return SK_DROP; + + skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS); + 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) +{ + struct sock *sk; + + if (unlikely(flags & ~(BPF_F_INGRESS))) + return SK_DROP; + + sk = __sock_hash_lookup_elem(map, key); + if (unlikely(!sk || !sock_map_redirect_allowed(sk))) + return SK_DROP; + if (!(flags & BPF_F_INGRESS) && !sk_is_tcp(sk)) + return SK_DROP; + + msg->flags = flags; + msg->sk_redir = sk; + 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, +}; + +struct sock_hash_seq_info { + struct bpf_map *map; + struct bpf_shtab *htab; + u32 bucket_id; +}; + +static void *sock_hash_seq_find_next(struct sock_hash_seq_info *info, + struct bpf_shtab_elem *prev_elem) +{ + const struct bpf_shtab *htab = info->htab; + struct bpf_shtab_bucket *bucket; + struct bpf_shtab_elem *elem; + struct hlist_node *node; + + /* try to find next elem in the same bucket */ + if (prev_elem) { + node = rcu_dereference(hlist_next_rcu(&prev_elem->node)); + elem = hlist_entry_safe(node, struct bpf_shtab_elem, node); + if (elem) + return elem; + + /* no more elements, continue in the next bucket */ + info->bucket_id++; + } + + for (; info->bucket_id < htab->buckets_num; info->bucket_id++) { + bucket = &htab->buckets[info->bucket_id]; + node = rcu_dereference(hlist_first_rcu(&bucket->head)); + elem = hlist_entry_safe(node, struct bpf_shtab_elem, node); + if (elem) + return elem; + } + + return NULL; +} + +static void *sock_hash_seq_start(struct seq_file *seq, loff_t *pos) + __acquires(rcu) +{ + struct sock_hash_seq_info *info = seq->private; + + if (*pos == 0) + ++*pos; + + /* pairs with sock_hash_seq_stop */ + rcu_read_lock(); + return sock_hash_seq_find_next(info, NULL); +} + +static void *sock_hash_seq_next(struct seq_file *seq, void *v, loff_t *pos) + __must_hold(rcu) +{ + struct sock_hash_seq_info *info = seq->private; + + ++*pos; + return sock_hash_seq_find_next(info, v); +} + +static int sock_hash_seq_show(struct seq_file *seq, void *v) + __must_hold(rcu) +{ + struct sock_hash_seq_info *info = seq->private; + struct bpf_iter__sockmap ctx = {}; + struct bpf_shtab_elem *elem = v; + struct bpf_iter_meta meta; + struct bpf_prog *prog; + + meta.seq = seq; + prog = bpf_iter_get_info(&meta, !elem); + if (!prog) + return 0; + + ctx.meta = &meta; + ctx.map = info->map; + if (elem) { + ctx.key = elem->key; + ctx.sk = elem->sk; + } + + return bpf_iter_run_prog(prog, &ctx); +} + +static void sock_hash_seq_stop(struct seq_file *seq, void *v) + __releases(rcu) +{ + if (!v) + (void)sock_hash_seq_show(seq, NULL); + + /* pairs with sock_hash_seq_start */ + rcu_read_unlock(); +} + +static const struct seq_operations sock_hash_seq_ops = { + .start = sock_hash_seq_start, + .next = sock_hash_seq_next, + .stop = sock_hash_seq_stop, + .show = sock_hash_seq_show, +}; + +static int sock_hash_init_seq_private(void *priv_data, + struct bpf_iter_aux_info *aux) +{ + struct sock_hash_seq_info *info = priv_data; + + bpf_map_inc_with_uref(aux->map); + info->map = aux->map; + info->htab = container_of(aux->map, struct bpf_shtab, map); + return 0; +} + +static void sock_hash_fini_seq_private(void *priv_data) +{ + struct sock_hash_seq_info *info = priv_data; + + bpf_map_put_with_uref(info->map); +} + +static const struct bpf_iter_seq_info sock_hash_iter_seq_info = { + .seq_ops = &sock_hash_seq_ops, + .init_seq_private = sock_hash_init_seq_private, + .fini_seq_private = sock_hash_fini_seq_private, + .seq_priv_size = sizeof(struct sock_hash_seq_info), +}; + +BTF_ID_LIST_SINGLE(sock_hash_map_btf_ids, struct, bpf_shtab) +const struct bpf_map_ops sock_hash_ops = { + .map_meta_equal = bpf_map_meta_equal, + .map_alloc = sock_hash_alloc, + .map_free = sock_hash_free, + .map_get_next_key = sock_hash_get_next_key, + .map_update_elem = sock_map_update_elem, + .map_delete_elem = sock_hash_delete_elem, + .map_lookup_elem = sock_hash_lookup, + .map_lookup_elem_sys_only = sock_hash_lookup_sys, + .map_release_uref = sock_hash_release_progs, + .map_check_btf = map_check_no_btf, + .map_btf_id = &sock_hash_map_btf_ids[0], + .iter_seq_info = &sock_hash_iter_seq_info, +}; + +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_shtab, map)->progs; + default: + break; + } + + return NULL; +} + +static int sock_map_prog_lookup(struct bpf_map *map, struct bpf_prog ***pprog, + u32 which) +{ + struct sk_psock_progs *progs = sock_map_progs(map); + + if (!progs) + return -EOPNOTSUPP; + + switch (which) { + case BPF_SK_MSG_VERDICT: + *pprog = &progs->msg_parser; + break; +#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER) + case BPF_SK_SKB_STREAM_PARSER: + *pprog = &progs->stream_parser; + break; +#endif + case BPF_SK_SKB_STREAM_VERDICT: + if (progs->skb_verdict) + return -EBUSY; + *pprog = &progs->stream_verdict; + break; + case BPF_SK_SKB_VERDICT: + if (progs->stream_verdict) + return -EBUSY; + *pprog = &progs->skb_verdict; + break; + default: + return -EOPNOTSUPP; + } + + return 0; +} + +static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, + struct bpf_prog *old, u32 which) +{ + struct bpf_prog **pprog; + int ret; + + ret = sock_map_prog_lookup(map, &pprog, which); + if (ret) + return ret; + + if (old) + return psock_replace_prog(pprog, prog, old); + + psock_set_prog(pprog, prog); + return 0; +} + +int sock_map_bpf_prog_query(const union bpf_attr *attr, + union bpf_attr __user *uattr) +{ + __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids); + u32 prog_cnt = 0, flags = 0, ufd = attr->target_fd; + struct bpf_prog **pprog; + struct bpf_prog *prog; + struct bpf_map *map; + struct fd f; + u32 id = 0; + int ret; + + if (attr->query.query_flags) + return -EINVAL; + + f = fdget(ufd); + map = __bpf_map_get(f); + if (IS_ERR(map)) + return PTR_ERR(map); + + rcu_read_lock(); + + ret = sock_map_prog_lookup(map, &pprog, attr->query.attach_type); + if (ret) + goto end; + + prog = *pprog; + prog_cnt = !prog ? 0 : 1; + + if (!attr->query.prog_cnt || !prog_ids || !prog_cnt) + goto end; + + /* we do not hold the refcnt, the bpf prog may be released + * asynchronously and the id would be set to 0. + */ + id = data_race(prog->aux->id); + if (id == 0) + prog_cnt = 0; + +end: + rcu_read_unlock(); + + if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)) || + (id != 0 && copy_to_user(prog_ids, &id, sizeof(u32))) || + copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt))) + ret = -EFAULT; + + fdput(f); + return ret; +} + +static void sock_map_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; + } +} + +static void sock_map_remove_links(struct sock *sk, struct sk_psock *psock) +{ + struct sk_psock_link *link; + + while ((link = sk_psock_link_pop(psock))) { + sock_map_unlink(sk, link); + sk_psock_free_link(link); + } +} + +void sock_map_unhash(struct sock *sk) +{ + void (*saved_unhash)(struct sock *sk); + struct sk_psock *psock; + + rcu_read_lock(); + psock = sk_psock(sk); + if (unlikely(!psock)) { + rcu_read_unlock(); + saved_unhash = READ_ONCE(sk->sk_prot)->unhash; + } else { + saved_unhash = psock->saved_unhash; + sock_map_remove_links(sk, psock); + rcu_read_unlock(); + } + if (WARN_ON_ONCE(saved_unhash == sock_map_unhash)) + return; + if (saved_unhash) + saved_unhash(sk); +} +EXPORT_SYMBOL_GPL(sock_map_unhash); + +void sock_map_destroy(struct sock *sk) +{ + void (*saved_destroy)(struct sock *sk); + struct sk_psock *psock; + + rcu_read_lock(); + psock = sk_psock_get(sk); + if (unlikely(!psock)) { + rcu_read_unlock(); + saved_destroy = READ_ONCE(sk->sk_prot)->destroy; + } else { + saved_destroy = psock->saved_destroy; + sock_map_remove_links(sk, psock); + rcu_read_unlock(); + sk_psock_stop(psock); + sk_psock_put(sk, psock); + } + if (WARN_ON_ONCE(saved_destroy == sock_map_destroy)) + return; + if (saved_destroy) + saved_destroy(sk); +} +EXPORT_SYMBOL_GPL(sock_map_destroy); + +void sock_map_close(struct sock *sk, long timeout) +{ + void (*saved_close)(struct sock *sk, long timeout); + struct sk_psock *psock; + + lock_sock(sk); + rcu_read_lock(); + psock = sk_psock_get(sk); + if (unlikely(!psock)) { + rcu_read_unlock(); + release_sock(sk); + saved_close = READ_ONCE(sk->sk_prot)->close; + } else { + saved_close = psock->saved_close; + sock_map_remove_links(sk, psock); + rcu_read_unlock(); + sk_psock_stop(psock); + release_sock(sk); + cancel_delayed_work_sync(&psock->work); + sk_psock_put(sk, psock); + } + + /* Make sure we do not recurse. This is a bug. + * Leak the socket instead of crashing on a stack overflow. + */ + if (WARN_ON_ONCE(saved_close == sock_map_close)) + return; + saved_close(sk, timeout); +} +EXPORT_SYMBOL_GPL(sock_map_close); + +static int sock_map_iter_attach_target(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_SOCKMAP && + map->map_type != BPF_MAP_TYPE_SOCKHASH) + goto put_map; + + if (prog->aux->max_rdonly_access > map->key_size) { + err = -EACCES; + goto put_map; + } + + aux->map = map; + return 0; + +put_map: + bpf_map_put_with_uref(map); + return err; +} + +static void sock_map_iter_detach_target(struct bpf_iter_aux_info *aux) +{ + bpf_map_put_with_uref(aux->map); +} + +static struct bpf_iter_reg sock_map_iter_reg = { + .target = "sockmap", + .attach_target = sock_map_iter_attach_target, + .detach_target = sock_map_iter_detach_target, + .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__sockmap, key), + PTR_TO_BUF | PTR_MAYBE_NULL | MEM_RDONLY }, + { offsetof(struct bpf_iter__sockmap, sk), + PTR_TO_BTF_ID_OR_NULL }, + }, +}; + +static int __init bpf_sockmap_iter_init(void) +{ + sock_map_iter_reg.ctx_arg_info[1].btf_id = + btf_sock_ids[BTF_SOCK_TYPE_SOCK]; + return bpf_iter_reg_target(&sock_map_iter_reg); +} +late_initcall(bpf_sockmap_iter_init); |