diff options
Diffstat (limited to 'net/core/sock_map.c')
| -rw-r--r-- | net/core/sock_map.c | 1434 |
1 files changed, 1195 insertions, 239 deletions
diff --git a/net/core/sock_map.c b/net/core/sock_map.c index be6092ac69f8..5947b38e4f8b 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -2,6 +2,7 @@ /* 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> @@ -10,74 +11,106 @@ #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; + spinlock_t lock; }; #define SOCK_CREATE_FLAG_MASK \ (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY) +/* This mutex is used to + * - protect race between prog/link attach/detach and link prog update, and + * - protect race between releasing and accessing map in bpf_link. + * A single global mutex lock is used since it is expected contention is low. + */ +static DEFINE_MUTEX(sockmap_mutex); + +static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, + struct bpf_prog *old, struct bpf_link *link, + 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; - 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->value_size != sizeof(u32) && + attr->value_size != sizeof(u64)) || attr->map_flags & ~SOCK_CREATE_FLAG_MASK) return ERR_PTR(-EINVAL); - stab = kzalloc(sizeof(*stab), GFP_USER); + 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); - - /* 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; + spin_lock_init(&stab->lock); - stab->sks = bpf_map_area_alloc(stab->map.max_entries * + stab->sks = bpf_map_area_alloc((u64) 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); + 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; - f = fdget(ufd); + if (attr->attach_flags || attr->replace_bpf_fd) + return -EINVAL; + + CLASS(fd, f)(attr->target_fd); 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); + mutex_lock(&sockmap_mutex); + ret = sock_map_prog_update(map, prog, NULL, NULL, attr->attach_type); + mutex_unlock(&sockmap_mutex); + return ret; +} + +int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype) +{ + struct bpf_prog *prog; + struct bpf_map *map; + int ret; + + if (attr->attach_flags || attr->replace_bpf_fd) + return -EINVAL; + + CLASS(fd, f)(attr->target_fd); + 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)) + return PTR_ERR(prog); + + if (prog->type != ptype) { + ret = -EINVAL; + goto put_prog; + } + + mutex_lock(&sockmap_mutex); + ret = sock_map_prog_update(map, NULL, prog, NULL, attr->attach_type); + mutex_unlock(&sockmap_mutex); +put_prog: + bpf_prog_put(prog); return ret; } @@ -85,7 +118,6 @@ static void sock_map_sk_acquire(struct sock *sk) __acquires(&sk->sk_lock.slock) { lock_sock(sk); - preempt_disable(); rcu_read_lock(); } @@ -93,7 +125,6 @@ static void sock_map_sk_release(struct sock *sk) __releases(&sk->sk_lock.slock) { rcu_read_unlock(); - preempt_enable(); release_sock(sk); } @@ -111,25 +142,36 @@ static void sock_map_add_link(struct sk_psock *psock, 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; - 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) + 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); + break; } } spin_unlock_bh(&psock->link_lock); - if (strp_stop) { + if (strp_stop || verdict_stop) { write_lock_bh(&sk->sk_callback_lock); - sk_psock_stop_strp(sk, psock); + 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); } } @@ -144,25 +186,57 @@ static void sock_map_unref(struct sock *sk, void *link_raw) } } -static int sock_map_link(struct bpf_map *map, struct sk_psock_progs *progs, - struct sock *sk) +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 bpf_prog *msg_parser, *skb_parser, *skb_verdict; - bool skb_progs, sk_psock_is_new = false; + 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; - 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); + 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; } } @@ -171,11 +245,20 @@ static int sock_map_link(struct bpf_map *map, struct sk_psock_progs *progs, msg_parser = bpf_prog_inc_not_zero(msg_parser); if (IS_ERR(msg_parser)) { ret = PTR_ERR(msg_parser); - goto out; + goto out_put_stream_parser; } } - psock = sk_psock_get_checked(sk); + 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; @@ -183,53 +266,73 @@ static int sock_map_link(struct bpf_map *map, struct sk_psock_progs *progs, if (psock) { if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) || - (skb_progs && READ_ONCE(psock->progs.skb_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 (!psock) { - ret = -ENOMEM; + if (IS_ERR(psock)) { + ret = PTR_ERR(psock); 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); + 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 (skb_progs && !psock->parser.enabled) { - ret = sk_psock_init_strp(sk, psock); + if (stream_parser && stream_verdict && !psock->saved_data_ready) { + if (sk_is_tcp(sk)) + ret = sk_psock_init_strp(sk, psock); + else + ret = -EOPNOTSUPP; if (ret) { write_unlock_bh(&sk->sk_callback_lock); - goto out_drop; + sk_psock_put(sk, psock); + goto out; } - psock_set_prog(&psock->progs.skb_verdict, skb_verdict); - psock_set_prog(&psock->progs.skb_parser, skb_parser); 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_drop: - sk_psock_put(sk, psock); 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: - if (skb_progs) { - bpf_prog_put(skb_verdict); - bpf_prog_put(skb_parser); - } return ret; } @@ -238,22 +341,32 @@ 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(); - 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) + 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); + } } - raw_spin_unlock_bh(&stab->lock); - rcu_read_unlock(); + + /* wait for psock readers accessing its map link */ + synchronize_rcu(); bpf_map_area_free(stab->sks); - kfree(stab); + bpf_map_area_free(stab); } static void sock_map_release_progs(struct bpf_map *map) @@ -274,23 +387,48 @@ static struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key) static void *sock_map_lookup(struct bpf_map *map, void *key) { - return ERR_PTR(-EOPNOTSUPP); + 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; + struct sock *sk = NULL; + int err = 0; - 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; + spin_lock_bh(&stab->lock); + if (!sk_test || sk_test == *psk) + sk = xchg(psk, NULL); + + if (likely(sk)) + sock_map_unref(sk, psk); + else + err = -EINVAL; + + spin_unlock_bh(&stab->lock); + return err; } static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk, @@ -301,7 +439,7 @@ static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk, __sock_map_delete(stab, sk, link_raw); } -static int sock_map_delete_elem(struct bpf_map *map, void *key) +static long 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; @@ -348,14 +486,14 @@ static int sock_map_update_common(struct bpf_map *map, u32 idx, if (!link) return -ENOMEM; - ret = sock_map_link(map, &stab->progs, sk); + 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); + spin_lock_bh(&stab->lock); osk = stab->sks[idx]; if (osk && flags == BPF_NOEXIST) { ret = -EEXIST; @@ -369,10 +507,10 @@ static int sock_map_update_common(struct bpf_map *map, u32 idx, stab->sks[idx] = sk; if (osk) sock_map_unref(osk, &stab->sks[idx]); - raw_spin_unlock_bh(&stab->lock); + spin_unlock_bh(&stab->lock); return 0; out_unlock: - raw_spin_unlock_bh(&stab->lock); + spin_unlock_bh(&stab->lock); if (psock) sk_psock_put(sk, psock); out_free: @@ -383,23 +521,52 @@ out_free: 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_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_type == SOCK_STREAM && - sk->sk_protocol == IPPROTO_TCP; + return !!sk->sk_prot->psock_update_sk_prot; } -static int sock_map_update_elem(struct bpf_map *map, void *key, - void *value, u64 flags) +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; + if (sk_is_vsock(sk) && + (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) + 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) { - u32 ufd = *(u32 *)value; - u32 idx = *(u32 *)key; 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) @@ -409,17 +576,46 @@ static int sock_map_update_elem(struct bpf_map *map, void *key, ret = -EINVAL; goto out; } - if (!sock_map_sk_is_suitable(sk) || - sk->sk_state != TCP_ESTABLISHED) { + if (!sock_map_sk_is_suitable(sk)) { ret = -EOPNOTSUPP; goto out; } sock_map_sk_acquire(sk); - ret = sock_map_update_common(map, idx, sk, flags); + 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: - fput(sock->file); + sockfd_put(sock); + return ret; +} + +static long 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; } @@ -449,14 +645,18 @@ const struct bpf_func_proto bpf_sock_map_update_proto = { 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); + struct sock *sk; 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) + + 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_vsock(sk)) return SK_DROP; + + skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS); return SK_PASS; } @@ -473,12 +673,21 @@ const struct bpf_func_proto bpf_sk_redirect_map_proto = { 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; - msg->flags = flags; - msg->sk_redir = __sock_map_lookup_elem(map, key); - if (!msg->sk_redir) + + 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; + if (sk_is_vsock(sk)) return SK_DROP; + + msg->flags = flags; + msg->sk_redir = sk; return SK_PASS; } @@ -492,33 +701,163 @@ const struct bpf_func_proto bpf_msg_redirect_map_proto = { .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 u64 sock_map_mem_usage(const struct bpf_map *map) +{ + u64 usage = sizeof(struct bpf_stab); + + usage += (u64)map->max_entries * sizeof(struct sock *); + return usage; +} + +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_mem_usage = sock_map_mem_usage, + .map_btf_id = &sock_map_btf_ids[0], + .iter_seq_info = &sock_map_iter_seq_info, }; -struct bpf_htab_elem { +struct bpf_shtab_elem { struct rcu_head rcu; u32 hash; struct sock *sk; struct hlist_node node; - u8 key[0]; + u8 key[]; }; -struct bpf_htab_bucket { +struct bpf_shtab_bucket { struct hlist_head head; - raw_spinlock_t lock; + spinlock_t lock; }; -struct bpf_htab { +struct bpf_shtab { struct bpf_map map; - struct bpf_htab_bucket *buckets; + struct bpf_shtab_bucket *buckets; u32 buckets_num; u32 elem_size; struct sk_psock_progs progs; @@ -530,17 +869,17 @@ 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) +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_htab_elem * +static struct bpf_shtab_elem * sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key, u32 key_size) { - struct bpf_htab_elem *elem; + struct bpf_shtab_elem *elem; hlist_for_each_entry_rcu(elem, head, node) { if (elem->hash == hash && @@ -553,10 +892,10 @@ sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key, static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key) { - struct bpf_htab *htab = container_of(map, struct bpf_htab, map); + struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); u32 key_size = map->key_size, hash; - struct bpf_htab_bucket *bucket; - struct bpf_htab_elem *elem; + struct bpf_shtab_bucket *bucket; + struct bpf_shtab_elem *elem; WARN_ON_ONCE(!rcu_read_lock_held()); @@ -567,8 +906,8 @@ static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key) return elem ? elem->sk : NULL; } -static void sock_hash_free_elem(struct bpf_htab *htab, - struct bpf_htab_elem *elem) +static void sock_hash_free_elem(struct bpf_shtab *htab, + struct bpf_shtab_elem *elem) { atomic_dec(&htab->count); kfree_rcu(elem, rcu); @@ -577,9 +916,9 @@ static void sock_hash_free_elem(struct bpf_htab *htab, 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; + 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); @@ -588,7 +927,7 @@ static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk, * 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); + 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) { @@ -596,21 +935,21 @@ static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk, sock_map_unref(elem->sk, elem); sock_hash_free_elem(htab, elem); } - raw_spin_unlock_bh(&bucket->lock); + spin_unlock_bh(&bucket->lock); } -static int sock_hash_delete_elem(struct bpf_map *map, void *key) +static long sock_hash_delete_elem(struct bpf_map *map, void *key) { - struct bpf_htab *htab = container_of(map, struct bpf_htab, map); + struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); u32 hash, key_size = map->key_size; - struct bpf_htab_bucket *bucket; - struct bpf_htab_elem *elem; + 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); + spin_lock_bh(&bucket->lock); elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); if (elem) { hlist_del_rcu(&elem->node); @@ -618,16 +957,16 @@ static int sock_hash_delete_elem(struct bpf_map *map, void *key) sock_hash_free_elem(htab, elem); ret = 0; } - raw_spin_unlock_bh(&bucket->lock); + 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) +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_htab_elem *new; + struct bpf_shtab_elem *new; if (atomic_inc_return(&htab->count) > htab->map.max_entries) { if (!old) { @@ -636,8 +975,9 @@ static struct bpf_htab_elem *sock_hash_alloc_elem(struct bpf_htab *htab, } } - new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN, - htab->map.numa_node); + 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); @@ -651,10 +991,10 @@ static struct bpf_htab_elem *sock_hash_alloc_elem(struct bpf_htab *htab, 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 bpf_shtab *htab = container_of(map, struct bpf_shtab, map); u32 key_size = map->key_size, hash; - struct bpf_htab_elem *elem, *elem_new; - struct bpf_htab_bucket *bucket; + struct bpf_shtab_elem *elem, *elem_new; + struct bpf_shtab_bucket *bucket; struct sk_psock_link *link; struct sk_psock *psock; int ret; @@ -667,7 +1007,7 @@ static int sock_hash_update_common(struct bpf_map *map, void *key, if (!link) return -ENOMEM; - ret = sock_map_link(map, &htab->progs, sk); + ret = sock_map_link(map, sk); if (ret < 0) goto out_free; @@ -677,7 +1017,7 @@ static int sock_hash_update_common(struct bpf_map *map, void *key, hash = sock_hash_bucket_hash(key, key_size); bucket = sock_hash_select_bucket(htab, hash); - raw_spin_lock_bh(&bucket->lock); + spin_lock_bh(&bucket->lock); elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); if (elem && flags == BPF_NOEXIST) { ret = -EEXIST; @@ -703,51 +1043,21 @@ static int sock_hash_update_common(struct bpf_map *map, void *key, sock_map_unref(elem->sk, elem); sock_hash_free_elem(htab, elem); } - raw_spin_unlock_bh(&bucket->lock); + spin_unlock_bh(&bucket->lock); return 0; out_unlock: - raw_spin_unlock_bh(&bucket->lock); + 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; + 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; @@ -760,8 +1070,8 @@ static int sock_hash_get_next_key(struct bpf_map *map, void *key, if (!elem) goto find_first_elem; - elem_next = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu(&elem->node)), - struct bpf_htab_elem, node); + 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; @@ -772,8 +1082,8 @@ static int sock_hash_get_next_key(struct bpf_map *map, void *key, 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); + 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; @@ -785,44 +1095,35 @@ find_first_elem: static struct bpf_map *sock_hash_alloc(union bpf_attr *attr) { - struct bpf_htab *htab; + struct bpf_shtab *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->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 = kzalloc(sizeof(*htab), GFP_USER); + 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_htab_elem) + + 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_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) { + 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_htab_bucket), + sizeof(struct bpf_shtab_bucket), htab->map.numa_node); if (!htab->buckets) { err = -ENOMEM; @@ -831,43 +1132,98 @@ static struct bpf_map *sock_hash_alloc(union bpf_attr *attr) for (i = 0; i < htab->buckets_num; i++) { INIT_HLIST_HEAD(&htab->buckets[i].head); - raw_spin_lock_init(&htab->buckets[i].lock); + spin_lock_init(&htab->buckets[i].lock); } return &htab->map; free_htab: - kfree(htab); + bpf_map_area_free(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 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(); - 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); + + /* 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. + */ + spin_lock_bh(&bucket->lock); + hlist_for_each_entry(elem, &bucket->head, node) + sock_hold(elem->sk); + hlist_move_list(&bucket->head, &unlink_list); + 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); } - raw_spin_unlock_bh(&bucket->lock); + cond_resched(); } - rcu_read_unlock(); + + /* wait for psock readers accessing its map link */ + synchronize_rcu(); bpf_map_area_free(htab->buckets); - kfree(htab); + 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_htab, map)->progs); + psock_progs_drop(&container_of(map, struct bpf_shtab, map)->progs); } BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops, @@ -895,14 +1251,18 @@ const struct bpf_func_proto bpf_sock_hash_update_proto = { 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); + struct sock *sk; 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) + + 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_vsock(sk)) return SK_DROP; + + skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS); return SK_PASS; } @@ -919,12 +1279,21 @@ const struct bpf_func_proto bpf_sk_redirect_hash_proto = { 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; - msg->flags = flags; - msg->sk_redir = __sock_hash_lookup_elem(map, key); - if (!msg->sk_redir) + + 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; + if (sk_is_vsock(sk)) + return SK_DROP; + + msg->flags = flags; + msg->sk_redir = sk; return SK_PASS; } @@ -938,15 +1307,155 @@ const struct bpf_func_proto bpf_msg_redirect_hash_proto = { .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 u64 sock_hash_mem_usage(const struct bpf_map *map) +{ + struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map); + u64 usage = sizeof(*htab); + + usage += htab->buckets_num * sizeof(struct bpf_shtab_bucket); + usage += atomic_read(&htab->count) * (u64)htab->elem_size; + return usage; +} + +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_hash_update_elem, + .map_update_elem = sock_map_update_elem, .map_delete_elem = sock_hash_delete_elem, - .map_lookup_elem = sock_map_lookup, + .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_mem_usage = sock_hash_mem_usage, + .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) @@ -955,7 +1464,7 @@ static struct sk_psock_progs *sock_map_progs(struct bpf_map *map) 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; + return &container_of(map, struct bpf_shtab, map)->progs; default: break; } @@ -963,32 +1472,136 @@ static struct sk_psock_progs *sock_map_progs(struct bpf_map *map) return NULL; } -int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, - u32 which) +static int sock_map_prog_link_lookup(struct bpf_map *map, struct bpf_prog ***pprog, + struct bpf_link ***plink, u32 which) { struct sk_psock_progs *progs = sock_map_progs(map); + struct bpf_prog **cur_pprog; + struct bpf_link **cur_plink; if (!progs) return -EOPNOTSUPP; switch (which) { case BPF_SK_MSG_VERDICT: - psock_set_prog(&progs->msg_parser, prog); + cur_pprog = &progs->msg_parser; + cur_plink = &progs->msg_parser_link; break; +#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER) case BPF_SK_SKB_STREAM_PARSER: - psock_set_prog(&progs->skb_parser, prog); + cur_pprog = &progs->stream_parser; + cur_plink = &progs->stream_parser_link; break; +#endif case BPF_SK_SKB_STREAM_VERDICT: - psock_set_prog(&progs->skb_verdict, prog); + if (progs->skb_verdict) + return -EBUSY; + cur_pprog = &progs->stream_verdict; + cur_plink = &progs->stream_verdict_link; + break; + case BPF_SK_SKB_VERDICT: + if (progs->stream_verdict) + return -EBUSY; + cur_pprog = &progs->skb_verdict; + cur_plink = &progs->skb_verdict_link; break; default: return -EOPNOTSUPP; } + *pprog = cur_pprog; + if (plink) + *plink = cur_plink; return 0; } -void sk_psock_unlink(struct sock *sk, struct sk_psock_link *link) +/* Handle the following four cases: + * prog_attach: prog != NULL, old == NULL, link == NULL + * prog_detach: prog == NULL, old != NULL, link == NULL + * link_attach: prog != NULL, old == NULL, link != NULL + * link_detach: prog == NULL, old != NULL, link != NULL + */ +static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, + struct bpf_prog *old, struct bpf_link *link, + u32 which) +{ + struct bpf_prog **pprog; + struct bpf_link **plink; + int ret; + + ret = sock_map_prog_link_lookup(map, &pprog, &plink, which); + if (ret) + return ret; + + /* for prog_attach/prog_detach/link_attach, return error if a bpf_link + * exists for that prog. + */ + if ((!link || prog) && *plink) + return -EBUSY; + + if (old) { + ret = psock_replace_prog(pprog, prog, old); + if (!ret) + *plink = NULL; + } else { + psock_set_prog(pprog, prog); + if (link) + *plink = link; + } + + return ret; +} + +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; + struct bpf_prog **pprog; + struct bpf_prog *prog; + struct bpf_map *map; + u32 id = 0; + int ret; + + if (attr->query.query_flags) + return -EINVAL; + + CLASS(fd, f)(attr->target_fd); + map = __bpf_map_get(f); + if (IS_ERR(map)) + return PTR_ERR(map); + + rcu_read_lock(); + + ret = sock_map_prog_link_lookup(map, &pprog, NULL, 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; + + 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: @@ -1001,3 +1614,346 @@ void sk_psock_unlink(struct sock *sk, struct sk_psock_link *link) 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(sk); + if (likely(psock)) { + saved_close = psock->saved_close; + sock_map_remove_links(sk, psock); + psock = sk_psock_get(sk); + if (unlikely(!psock)) + goto no_psock; + rcu_read_unlock(); + sk_psock_stop(psock); + release_sock(sk); + cancel_delayed_work_sync(&psock->work); + sk_psock_put(sk, psock); + } else { + saved_close = READ_ONCE(sk->sk_prot)->close; +no_psock: + rcu_read_unlock(); + release_sock(sk); + } + + /* 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); + +struct sockmap_link { + struct bpf_link link; + struct bpf_map *map; +}; + +static void sock_map_link_release(struct bpf_link *link) +{ + struct sockmap_link *sockmap_link = container_of(link, struct sockmap_link, link); + + mutex_lock(&sockmap_mutex); + if (!sockmap_link->map) + goto out; + + WARN_ON_ONCE(sock_map_prog_update(sockmap_link->map, NULL, link->prog, link, + link->attach_type)); + + bpf_map_put_with_uref(sockmap_link->map); + sockmap_link->map = NULL; +out: + mutex_unlock(&sockmap_mutex); +} + +static int sock_map_link_detach(struct bpf_link *link) +{ + sock_map_link_release(link); + return 0; +} + +static void sock_map_link_dealloc(struct bpf_link *link) +{ + kfree(link); +} + +/* Handle the following two cases: + * case 1: link != NULL, prog != NULL, old != NULL + * case 2: link != NULL, prog != NULL, old == NULL + */ +static int sock_map_link_update_prog(struct bpf_link *link, + struct bpf_prog *prog, + struct bpf_prog *old) +{ + const struct sockmap_link *sockmap_link = container_of(link, struct sockmap_link, link); + struct bpf_prog **pprog, *old_link_prog; + struct bpf_link **plink; + int ret = 0; + + mutex_lock(&sockmap_mutex); + + /* If old prog is not NULL, ensure old prog is the same as link->prog. */ + if (old && link->prog != old) { + ret = -EPERM; + goto out; + } + /* Ensure link->prog has the same type/attach_type as the new prog. */ + if (link->prog->type != prog->type || + link->prog->expected_attach_type != prog->expected_attach_type) { + ret = -EINVAL; + goto out; + } + if (!sockmap_link->map) { + ret = -ENOLINK; + goto out; + } + + ret = sock_map_prog_link_lookup(sockmap_link->map, &pprog, &plink, + link->attach_type); + if (ret) + goto out; + + /* return error if the stored bpf_link does not match the incoming bpf_link. */ + if (link != *plink) { + ret = -EBUSY; + goto out; + } + + if (old) { + ret = psock_replace_prog(pprog, prog, old); + if (ret) + goto out; + } else { + psock_set_prog(pprog, prog); + } + + bpf_prog_inc(prog); + old_link_prog = xchg(&link->prog, prog); + bpf_prog_put(old_link_prog); + +out: + mutex_unlock(&sockmap_mutex); + return ret; +} + +static u32 sock_map_link_get_map_id(const struct sockmap_link *sockmap_link) +{ + u32 map_id = 0; + + mutex_lock(&sockmap_mutex); + if (sockmap_link->map) + map_id = sockmap_link->map->id; + mutex_unlock(&sockmap_mutex); + return map_id; +} + +static int sock_map_link_fill_info(const struct bpf_link *link, + struct bpf_link_info *info) +{ + const struct sockmap_link *sockmap_link = container_of(link, struct sockmap_link, link); + u32 map_id = sock_map_link_get_map_id(sockmap_link); + + info->sockmap.map_id = map_id; + info->sockmap.attach_type = link->attach_type; + return 0; +} + +static void sock_map_link_show_fdinfo(const struct bpf_link *link, + struct seq_file *seq) +{ + const struct sockmap_link *sockmap_link = container_of(link, struct sockmap_link, link); + u32 map_id = sock_map_link_get_map_id(sockmap_link); + + seq_printf(seq, "map_id:\t%u\n", map_id); + seq_printf(seq, "attach_type:\t%u\n", link->attach_type); +} + +static const struct bpf_link_ops sock_map_link_ops = { + .release = sock_map_link_release, + .dealloc = sock_map_link_dealloc, + .detach = sock_map_link_detach, + .update_prog = sock_map_link_update_prog, + .fill_link_info = sock_map_link_fill_info, + .show_fdinfo = sock_map_link_show_fdinfo, +}; + +int sock_map_link_create(const union bpf_attr *attr, struct bpf_prog *prog) +{ + struct bpf_link_primer link_primer; + struct sockmap_link *sockmap_link; + enum bpf_attach_type attach_type; + struct bpf_map *map; + int ret; + + if (attr->link_create.flags) + return -EINVAL; + + map = bpf_map_get_with_uref(attr->link_create.target_fd); + if (IS_ERR(map)) + return PTR_ERR(map); + if (map->map_type != BPF_MAP_TYPE_SOCKMAP && map->map_type != BPF_MAP_TYPE_SOCKHASH) { + ret = -EINVAL; + goto out; + } + + sockmap_link = kzalloc(sizeof(*sockmap_link), GFP_USER); + if (!sockmap_link) { + ret = -ENOMEM; + goto out; + } + + attach_type = attr->link_create.attach_type; + bpf_link_init(&sockmap_link->link, BPF_LINK_TYPE_SOCKMAP, &sock_map_link_ops, prog, + attach_type); + sockmap_link->map = map; + + ret = bpf_link_prime(&sockmap_link->link, &link_primer); + if (ret) { + kfree(sockmap_link); + goto out; + } + + mutex_lock(&sockmap_mutex); + ret = sock_map_prog_update(map, prog, NULL, &sockmap_link->link, attach_type); + mutex_unlock(&sockmap_mutex); + if (ret) { + bpf_link_cleanup(&link_primer); + goto out; + } + + /* Increase refcnt for the prog since when old prog is replaced with + * psock_replace_prog() and psock_set_prog() its refcnt will be decreased. + * + * Actually, we do not need to increase refcnt for the prog since bpf_link + * will hold a reference. But in order to have less complexity w.r.t. + * replacing/setting prog, let us increase the refcnt to make things simpler. + */ + bpf_prog_inc(prog); + + return bpf_link_settle(&link_primer); + +out: + bpf_map_put_with_uref(map); + return ret; +} + +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); |