1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */
5 #include <linux/btf_ids.h>
6 #include <linux/filter.h>
7 #include <linux/errno.h>
8 #include <linux/file.h>
10 #include <linux/workqueue.h>
11 #include <linux/skmsg.h>
12 #include <linux/list.h>
13 #include <linux/jhash.h>
14 #include <linux/sock_diag.h>
20 struct sk_psock_progs progs;
24 #define SOCK_CREATE_FLAG_MASK \
25 (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
27 static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
29 struct bpf_stab *stab;
33 if (!capable(CAP_NET_ADMIN))
34 return ERR_PTR(-EPERM);
35 if (attr->max_entries == 0 ||
36 attr->key_size != 4 ||
37 (attr->value_size != sizeof(u32) &&
38 attr->value_size != sizeof(u64)) ||
39 attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
40 return ERR_PTR(-EINVAL);
42 stab = kzalloc(sizeof(*stab), GFP_USER);
44 return ERR_PTR(-ENOMEM);
46 bpf_map_init_from_attr(&stab->map, attr);
47 raw_spin_lock_init(&stab->lock);
49 /* Make sure page count doesn't overflow. */
50 cost = (u64) stab->map.max_entries * sizeof(struct sock *);
51 err = bpf_map_charge_init(&stab->map.memory, cost);
55 stab->sks = bpf_map_area_alloc((u64) stab->map.max_entries *
56 sizeof(struct sock *),
61 bpf_map_charge_finish(&stab->map.memory);
67 int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog)
69 u32 ufd = attr->target_fd;
74 if (attr->attach_flags || attr->replace_bpf_fd)
78 map = __bpf_map_get(f);
81 ret = sock_map_prog_update(map, prog, NULL, attr->attach_type);
86 int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
88 u32 ufd = attr->target_fd;
89 struct bpf_prog *prog;
94 if (attr->attach_flags || attr->replace_bpf_fd)
98 map = __bpf_map_get(f);
102 prog = bpf_prog_get(attr->attach_bpf_fd);
108 if (prog->type != ptype) {
113 ret = sock_map_prog_update(map, NULL, prog, attr->attach_type);
121 static void sock_map_sk_acquire(struct sock *sk)
122 __acquires(&sk->sk_lock.slock)
129 static void sock_map_sk_release(struct sock *sk)
130 __releases(&sk->sk_lock.slock)
137 static void sock_map_add_link(struct sk_psock *psock,
138 struct sk_psock_link *link,
139 struct bpf_map *map, void *link_raw)
141 link->link_raw = link_raw;
143 spin_lock_bh(&psock->link_lock);
144 list_add_tail(&link->list, &psock->link);
145 spin_unlock_bh(&psock->link_lock);
148 static void sock_map_del_link(struct sock *sk,
149 struct sk_psock *psock, void *link_raw)
151 bool strp_stop = false, verdict_stop = false;
152 struct sk_psock_link *link, *tmp;
154 spin_lock_bh(&psock->link_lock);
155 list_for_each_entry_safe(link, tmp, &psock->link, list) {
156 if (link->link_raw == link_raw) {
157 struct bpf_map *map = link->map;
158 struct bpf_stab *stab = container_of(map, struct bpf_stab,
160 if (psock->parser.enabled && stab->progs.skb_parser)
162 if (psock->parser.enabled && stab->progs.skb_verdict)
164 list_del(&link->list);
165 sk_psock_free_link(link);
168 spin_unlock_bh(&psock->link_lock);
169 if (strp_stop || verdict_stop) {
170 write_lock_bh(&sk->sk_callback_lock);
172 sk_psock_stop_strp(sk, psock);
174 sk_psock_stop_verdict(sk, psock);
175 write_unlock_bh(&sk->sk_callback_lock);
179 static void sock_map_unref(struct sock *sk, void *link_raw)
181 struct sk_psock *psock = sk_psock(sk);
184 sock_map_del_link(sk, psock, link_raw);
185 sk_psock_put(sk, psock);
189 static int sock_map_init_proto(struct sock *sk, struct sk_psock *psock)
193 switch (sk->sk_type) {
195 prot = tcp_bpf_get_proto(sk, psock);
199 prot = udp_bpf_get_proto(sk, psock);
207 return PTR_ERR(prot);
209 sk_psock_update_proto(sk, psock, prot);
213 static struct sk_psock *sock_map_psock_get_checked(struct sock *sk)
215 struct sk_psock *psock;
218 psock = sk_psock(sk);
220 if (sk->sk_prot->close != sock_map_close) {
221 psock = ERR_PTR(-EBUSY);
225 if (!refcount_inc_not_zero(&psock->refcnt))
226 psock = ERR_PTR(-EBUSY);
233 static int sock_map_link(struct bpf_map *map, struct sk_psock_progs *progs,
236 struct bpf_prog *msg_parser, *skb_parser, *skb_verdict;
237 struct sk_psock *psock;
240 skb_verdict = READ_ONCE(progs->skb_verdict);
242 skb_verdict = bpf_prog_inc_not_zero(skb_verdict);
243 if (IS_ERR(skb_verdict))
244 return PTR_ERR(skb_verdict);
247 skb_parser = READ_ONCE(progs->skb_parser);
249 skb_parser = bpf_prog_inc_not_zero(skb_parser);
250 if (IS_ERR(skb_parser)) {
251 ret = PTR_ERR(skb_parser);
252 goto out_put_skb_verdict;
256 msg_parser = READ_ONCE(progs->msg_parser);
258 msg_parser = bpf_prog_inc_not_zero(msg_parser);
259 if (IS_ERR(msg_parser)) {
260 ret = PTR_ERR(msg_parser);
261 goto out_put_skb_parser;
265 psock = sock_map_psock_get_checked(sk);
267 ret = PTR_ERR(psock);
272 if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) ||
273 (skb_parser && READ_ONCE(psock->progs.skb_parser)) ||
274 (skb_verdict && READ_ONCE(psock->progs.skb_verdict))) {
275 sk_psock_put(sk, psock);
280 psock = sk_psock_init(sk, map->numa_node);
282 ret = PTR_ERR(psock);
288 psock_set_prog(&psock->progs.msg_parser, msg_parser);
290 ret = sock_map_init_proto(sk, psock);
294 write_lock_bh(&sk->sk_callback_lock);
295 if (skb_parser && skb_verdict && !psock->parser.enabled) {
296 ret = sk_psock_init_strp(sk, psock);
298 goto out_unlock_drop;
299 psock_set_prog(&psock->progs.skb_verdict, skb_verdict);
300 psock_set_prog(&psock->progs.skb_parser, skb_parser);
301 sk_psock_start_strp(sk, psock);
302 } else if (!skb_parser && skb_verdict && !psock->parser.enabled) {
303 psock_set_prog(&psock->progs.skb_verdict, skb_verdict);
304 sk_psock_start_verdict(sk,psock);
306 write_unlock_bh(&sk->sk_callback_lock);
309 write_unlock_bh(&sk->sk_callback_lock);
311 sk_psock_put(sk, psock);
314 bpf_prog_put(msg_parser);
317 bpf_prog_put(skb_parser);
320 bpf_prog_put(skb_verdict);
324 static int sock_map_link_no_progs(struct bpf_map *map, struct sock *sk)
326 struct sk_psock *psock;
329 psock = sock_map_psock_get_checked(sk);
331 return PTR_ERR(psock);
334 psock = sk_psock_init(sk, map->numa_node);
336 return PTR_ERR(psock);
339 ret = sock_map_init_proto(sk, psock);
341 sk_psock_put(sk, psock);
345 static void sock_map_free(struct bpf_map *map)
347 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
350 /* After the sync no updates or deletes will be in-flight so it
351 * is safe to walk map and remove entries without risking a race
352 * in EEXIST update case.
355 for (i = 0; i < stab->map.max_entries; i++) {
356 struct sock **psk = &stab->sks[i];
359 sk = xchg(psk, NULL);
363 sock_map_unref(sk, psk);
369 /* wait for psock readers accessing its map link */
372 bpf_map_area_free(stab->sks);
376 static void sock_map_release_progs(struct bpf_map *map)
378 psock_progs_drop(&container_of(map, struct bpf_stab, map)->progs);
381 static struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
383 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
385 WARN_ON_ONCE(!rcu_read_lock_held());
387 if (unlikely(key >= map->max_entries))
389 return READ_ONCE(stab->sks[key]);
392 static void *sock_map_lookup(struct bpf_map *map, void *key)
396 sk = __sock_map_lookup_elem(map, *(u32 *)key);
399 if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
404 static void *sock_map_lookup_sys(struct bpf_map *map, void *key)
408 if (map->value_size != sizeof(u64))
409 return ERR_PTR(-ENOSPC);
411 sk = __sock_map_lookup_elem(map, *(u32 *)key);
413 return ERR_PTR(-ENOENT);
415 __sock_gen_cookie(sk);
416 return &sk->sk_cookie;
419 static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test,
425 raw_spin_lock_bh(&stab->lock);
427 if (!sk_test || sk_test == sk)
428 sk = xchg(psk, NULL);
431 sock_map_unref(sk, psk);
435 raw_spin_unlock_bh(&stab->lock);
439 static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk,
442 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
444 __sock_map_delete(stab, sk, link_raw);
447 static int sock_map_delete_elem(struct bpf_map *map, void *key)
449 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
453 if (unlikely(i >= map->max_entries))
457 return __sock_map_delete(stab, NULL, psk);
460 static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next)
462 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
463 u32 i = key ? *(u32 *)key : U32_MAX;
464 u32 *key_next = next;
466 if (i == stab->map.max_entries - 1)
468 if (i >= stab->map.max_entries)
475 static bool sock_map_redirect_allowed(const struct sock *sk);
477 static int sock_map_update_common(struct bpf_map *map, u32 idx,
478 struct sock *sk, u64 flags)
480 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
481 struct sk_psock_link *link;
482 struct sk_psock *psock;
486 WARN_ON_ONCE(!rcu_read_lock_held());
487 if (unlikely(flags > BPF_EXIST))
489 if (unlikely(idx >= map->max_entries))
492 link = sk_psock_init_link();
496 /* Only sockets we can redirect into/from in BPF need to hold
497 * refs to parser/verdict progs and have their sk_data_ready
498 * and sk_write_space callbacks overridden.
500 if (sock_map_redirect_allowed(sk))
501 ret = sock_map_link(map, &stab->progs, sk);
503 ret = sock_map_link_no_progs(map, sk);
507 psock = sk_psock(sk);
508 WARN_ON_ONCE(!psock);
510 raw_spin_lock_bh(&stab->lock);
511 osk = stab->sks[idx];
512 if (osk && flags == BPF_NOEXIST) {
515 } else if (!osk && flags == BPF_EXIST) {
520 sock_map_add_link(psock, link, map, &stab->sks[idx]);
523 sock_map_unref(osk, &stab->sks[idx]);
524 raw_spin_unlock_bh(&stab->lock);
527 raw_spin_unlock_bh(&stab->lock);
529 sk_psock_put(sk, psock);
531 sk_psock_free_link(link);
535 static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops)
537 return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB ||
538 ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB ||
539 ops->op == BPF_SOCK_OPS_TCP_LISTEN_CB;
542 static bool sk_is_tcp(const struct sock *sk)
544 return sk->sk_type == SOCK_STREAM &&
545 sk->sk_protocol == IPPROTO_TCP;
548 static bool sk_is_udp(const struct sock *sk)
550 return sk->sk_type == SOCK_DGRAM &&
551 sk->sk_protocol == IPPROTO_UDP;
554 static bool sock_map_redirect_allowed(const struct sock *sk)
556 return sk_is_tcp(sk) && sk->sk_state != TCP_LISTEN;
559 static bool sock_map_sk_is_suitable(const struct sock *sk)
561 return sk_is_tcp(sk) || sk_is_udp(sk);
564 static bool sock_map_sk_state_allowed(const struct sock *sk)
567 return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_LISTEN);
568 else if (sk_is_udp(sk))
569 return sk_hashed(sk);
574 static int sock_hash_update_common(struct bpf_map *map, void *key,
575 struct sock *sk, u64 flags);
577 int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value,
585 if (map->value_size == sizeof(u64))
592 sock = sockfd_lookup(ufd, &ret);
600 if (!sock_map_sk_is_suitable(sk)) {
605 sock_map_sk_acquire(sk);
606 if (!sock_map_sk_state_allowed(sk))
608 else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
609 ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
611 ret = sock_hash_update_common(map, key, sk, flags);
612 sock_map_sk_release(sk);
618 static int sock_map_update_elem(struct bpf_map *map, void *key,
619 void *value, u64 flags)
621 struct sock *sk = (struct sock *)value;
624 if (unlikely(!sk || !sk_fullsock(sk)))
627 if (!sock_map_sk_is_suitable(sk))
632 if (!sock_map_sk_state_allowed(sk))
634 else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
635 ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
637 ret = sock_hash_update_common(map, key, sk, flags);
643 BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops,
644 struct bpf_map *, map, void *, key, u64, flags)
646 WARN_ON_ONCE(!rcu_read_lock_held());
648 if (likely(sock_map_sk_is_suitable(sops->sk) &&
649 sock_map_op_okay(sops)))
650 return sock_map_update_common(map, *(u32 *)key, sops->sk,
655 const struct bpf_func_proto bpf_sock_map_update_proto = {
656 .func = bpf_sock_map_update,
659 .ret_type = RET_INTEGER,
660 .arg1_type = ARG_PTR_TO_CTX,
661 .arg2_type = ARG_CONST_MAP_PTR,
662 .arg3_type = ARG_PTR_TO_MAP_KEY,
663 .arg4_type = ARG_ANYTHING,
666 BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb,
667 struct bpf_map *, map, u32, key, u64, flags)
669 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
672 if (unlikely(flags & ~(BPF_F_INGRESS)))
675 sk = __sock_map_lookup_elem(map, key);
676 if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
679 tcb->bpf.flags = flags;
680 tcb->bpf.sk_redir = sk;
684 const struct bpf_func_proto bpf_sk_redirect_map_proto = {
685 .func = bpf_sk_redirect_map,
687 .ret_type = RET_INTEGER,
688 .arg1_type = ARG_PTR_TO_CTX,
689 .arg2_type = ARG_CONST_MAP_PTR,
690 .arg3_type = ARG_ANYTHING,
691 .arg4_type = ARG_ANYTHING,
694 BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg,
695 struct bpf_map *, map, u32, key, u64, flags)
699 if (unlikely(flags & ~(BPF_F_INGRESS)))
702 sk = __sock_map_lookup_elem(map, key);
703 if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
711 const struct bpf_func_proto bpf_msg_redirect_map_proto = {
712 .func = bpf_msg_redirect_map,
714 .ret_type = RET_INTEGER,
715 .arg1_type = ARG_PTR_TO_CTX,
716 .arg2_type = ARG_CONST_MAP_PTR,
717 .arg3_type = ARG_ANYTHING,
718 .arg4_type = ARG_ANYTHING,
721 struct sock_map_seq_info {
727 struct bpf_iter__sockmap {
728 __bpf_md_ptr(struct bpf_iter_meta *, meta);
729 __bpf_md_ptr(struct bpf_map *, map);
730 __bpf_md_ptr(void *, key);
731 __bpf_md_ptr(struct sock *, sk);
734 DEFINE_BPF_ITER_FUNC(sockmap, struct bpf_iter_meta *meta,
735 struct bpf_map *map, void *key,
738 static void *sock_map_seq_lookup_elem(struct sock_map_seq_info *info)
740 if (unlikely(info->index >= info->map->max_entries))
743 info->sk = __sock_map_lookup_elem(info->map, info->index);
745 /* can't return sk directly, since that might be NULL */
749 static void *sock_map_seq_start(struct seq_file *seq, loff_t *pos)
752 struct sock_map_seq_info *info = seq->private;
757 /* pairs with sock_map_seq_stop */
759 return sock_map_seq_lookup_elem(info);
762 static void *sock_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
765 struct sock_map_seq_info *info = seq->private;
770 return sock_map_seq_lookup_elem(info);
773 static int sock_map_seq_show(struct seq_file *seq, void *v)
776 struct sock_map_seq_info *info = seq->private;
777 struct bpf_iter__sockmap ctx = {};
778 struct bpf_iter_meta meta;
779 struct bpf_prog *prog;
782 prog = bpf_iter_get_info(&meta, !v);
789 ctx.key = &info->index;
793 return bpf_iter_run_prog(prog, &ctx);
796 static void sock_map_seq_stop(struct seq_file *seq, void *v)
800 (void)sock_map_seq_show(seq, NULL);
802 /* pairs with sock_map_seq_start */
806 static const struct seq_operations sock_map_seq_ops = {
807 .start = sock_map_seq_start,
808 .next = sock_map_seq_next,
809 .stop = sock_map_seq_stop,
810 .show = sock_map_seq_show,
813 static int sock_map_init_seq_private(void *priv_data,
814 struct bpf_iter_aux_info *aux)
816 struct sock_map_seq_info *info = priv_data;
818 bpf_map_inc_with_uref(aux->map);
819 info->map = aux->map;
823 static void sock_map_fini_seq_private(void *priv_data)
825 struct sock_map_seq_info *info = priv_data;
827 bpf_map_put_with_uref(info->map);
830 static const struct bpf_iter_seq_info sock_map_iter_seq_info = {
831 .seq_ops = &sock_map_seq_ops,
832 .init_seq_private = sock_map_init_seq_private,
833 .fini_seq_private = sock_map_fini_seq_private,
834 .seq_priv_size = sizeof(struct sock_map_seq_info),
837 static int sock_map_btf_id;
838 const struct bpf_map_ops sock_map_ops = {
839 .map_meta_equal = bpf_map_meta_equal,
840 .map_alloc = sock_map_alloc,
841 .map_free = sock_map_free,
842 .map_get_next_key = sock_map_get_next_key,
843 .map_lookup_elem_sys_only = sock_map_lookup_sys,
844 .map_update_elem = sock_map_update_elem,
845 .map_delete_elem = sock_map_delete_elem,
846 .map_lookup_elem = sock_map_lookup,
847 .map_release_uref = sock_map_release_progs,
848 .map_check_btf = map_check_no_btf,
849 .map_btf_name = "bpf_stab",
850 .map_btf_id = &sock_map_btf_id,
851 .iter_seq_info = &sock_map_iter_seq_info,
854 struct bpf_shtab_elem {
858 struct hlist_node node;
862 struct bpf_shtab_bucket {
863 struct hlist_head head;
869 struct bpf_shtab_bucket *buckets;
872 struct sk_psock_progs progs;
876 static inline u32 sock_hash_bucket_hash(const void *key, u32 len)
878 return jhash(key, len, 0);
881 static struct bpf_shtab_bucket *sock_hash_select_bucket(struct bpf_shtab *htab,
884 return &htab->buckets[hash & (htab->buckets_num - 1)];
887 static struct bpf_shtab_elem *
888 sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key,
891 struct bpf_shtab_elem *elem;
893 hlist_for_each_entry_rcu(elem, head, node) {
894 if (elem->hash == hash &&
895 !memcmp(&elem->key, key, key_size))
902 static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key)
904 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
905 u32 key_size = map->key_size, hash;
906 struct bpf_shtab_bucket *bucket;
907 struct bpf_shtab_elem *elem;
909 WARN_ON_ONCE(!rcu_read_lock_held());
911 hash = sock_hash_bucket_hash(key, key_size);
912 bucket = sock_hash_select_bucket(htab, hash);
913 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
915 return elem ? elem->sk : NULL;
918 static void sock_hash_free_elem(struct bpf_shtab *htab,
919 struct bpf_shtab_elem *elem)
921 atomic_dec(&htab->count);
922 kfree_rcu(elem, rcu);
925 static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk,
928 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
929 struct bpf_shtab_elem *elem_probe, *elem = link_raw;
930 struct bpf_shtab_bucket *bucket;
932 WARN_ON_ONCE(!rcu_read_lock_held());
933 bucket = sock_hash_select_bucket(htab, elem->hash);
935 /* elem may be deleted in parallel from the map, but access here
936 * is okay since it's going away only after RCU grace period.
937 * However, we need to check whether it's still present.
939 raw_spin_lock_bh(&bucket->lock);
940 elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash,
941 elem->key, map->key_size);
942 if (elem_probe && elem_probe == elem) {
943 hlist_del_rcu(&elem->node);
944 sock_map_unref(elem->sk, elem);
945 sock_hash_free_elem(htab, elem);
947 raw_spin_unlock_bh(&bucket->lock);
950 static int sock_hash_delete_elem(struct bpf_map *map, void *key)
952 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
953 u32 hash, key_size = map->key_size;
954 struct bpf_shtab_bucket *bucket;
955 struct bpf_shtab_elem *elem;
958 hash = sock_hash_bucket_hash(key, key_size);
959 bucket = sock_hash_select_bucket(htab, hash);
961 raw_spin_lock_bh(&bucket->lock);
962 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
964 hlist_del_rcu(&elem->node);
965 sock_map_unref(elem->sk, elem);
966 sock_hash_free_elem(htab, elem);
969 raw_spin_unlock_bh(&bucket->lock);
973 static struct bpf_shtab_elem *sock_hash_alloc_elem(struct bpf_shtab *htab,
974 void *key, u32 key_size,
975 u32 hash, struct sock *sk,
976 struct bpf_shtab_elem *old)
978 struct bpf_shtab_elem *new;
980 if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
982 atomic_dec(&htab->count);
983 return ERR_PTR(-E2BIG);
987 new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN,
988 htab->map.numa_node);
990 atomic_dec(&htab->count);
991 return ERR_PTR(-ENOMEM);
993 memcpy(new->key, key, key_size);
999 static int sock_hash_update_common(struct bpf_map *map, void *key,
1000 struct sock *sk, u64 flags)
1002 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1003 u32 key_size = map->key_size, hash;
1004 struct bpf_shtab_elem *elem, *elem_new;
1005 struct bpf_shtab_bucket *bucket;
1006 struct sk_psock_link *link;
1007 struct sk_psock *psock;
1010 WARN_ON_ONCE(!rcu_read_lock_held());
1011 if (unlikely(flags > BPF_EXIST))
1014 link = sk_psock_init_link();
1018 /* Only sockets we can redirect into/from in BPF need to hold
1019 * refs to parser/verdict progs and have their sk_data_ready
1020 * and sk_write_space callbacks overridden.
1022 if (sock_map_redirect_allowed(sk))
1023 ret = sock_map_link(map, &htab->progs, sk);
1025 ret = sock_map_link_no_progs(map, sk);
1029 psock = sk_psock(sk);
1030 WARN_ON_ONCE(!psock);
1032 hash = sock_hash_bucket_hash(key, key_size);
1033 bucket = sock_hash_select_bucket(htab, hash);
1035 raw_spin_lock_bh(&bucket->lock);
1036 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
1037 if (elem && flags == BPF_NOEXIST) {
1040 } else if (!elem && flags == BPF_EXIST) {
1045 elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem);
1046 if (IS_ERR(elem_new)) {
1047 ret = PTR_ERR(elem_new);
1051 sock_map_add_link(psock, link, map, elem_new);
1052 /* Add new element to the head of the list, so that
1053 * concurrent search will find it before old elem.
1055 hlist_add_head_rcu(&elem_new->node, &bucket->head);
1057 hlist_del_rcu(&elem->node);
1058 sock_map_unref(elem->sk, elem);
1059 sock_hash_free_elem(htab, elem);
1061 raw_spin_unlock_bh(&bucket->lock);
1064 raw_spin_unlock_bh(&bucket->lock);
1065 sk_psock_put(sk, psock);
1067 sk_psock_free_link(link);
1071 static int sock_hash_get_next_key(struct bpf_map *map, void *key,
1074 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1075 struct bpf_shtab_elem *elem, *elem_next;
1076 u32 hash, key_size = map->key_size;
1077 struct hlist_head *head;
1081 goto find_first_elem;
1082 hash = sock_hash_bucket_hash(key, key_size);
1083 head = &sock_hash_select_bucket(htab, hash)->head;
1084 elem = sock_hash_lookup_elem_raw(head, hash, key, key_size);
1086 goto find_first_elem;
1088 elem_next = hlist_entry_safe(rcu_dereference(hlist_next_rcu(&elem->node)),
1089 struct bpf_shtab_elem, node);
1091 memcpy(key_next, elem_next->key, key_size);
1095 i = hash & (htab->buckets_num - 1);
1098 for (; i < htab->buckets_num; i++) {
1099 head = &sock_hash_select_bucket(htab, i)->head;
1100 elem_next = hlist_entry_safe(rcu_dereference(hlist_first_rcu(head)),
1101 struct bpf_shtab_elem, node);
1103 memcpy(key_next, elem_next->key, key_size);
1111 static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
1113 struct bpf_shtab *htab;
1117 if (!capable(CAP_NET_ADMIN))
1118 return ERR_PTR(-EPERM);
1119 if (attr->max_entries == 0 ||
1120 attr->key_size == 0 ||
1121 (attr->value_size != sizeof(u32) &&
1122 attr->value_size != sizeof(u64)) ||
1123 attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
1124 return ERR_PTR(-EINVAL);
1125 if (attr->key_size > MAX_BPF_STACK)
1126 return ERR_PTR(-E2BIG);
1128 htab = kzalloc(sizeof(*htab), GFP_USER);
1130 return ERR_PTR(-ENOMEM);
1132 bpf_map_init_from_attr(&htab->map, attr);
1134 htab->buckets_num = roundup_pow_of_two(htab->map.max_entries);
1135 htab->elem_size = sizeof(struct bpf_shtab_elem) +
1136 round_up(htab->map.key_size, 8);
1137 if (htab->buckets_num == 0 ||
1138 htab->buckets_num > U32_MAX / sizeof(struct bpf_shtab_bucket)) {
1143 cost = (u64) htab->buckets_num * sizeof(struct bpf_shtab_bucket) +
1144 (u64) htab->elem_size * htab->map.max_entries;
1145 if (cost >= U32_MAX - PAGE_SIZE) {
1149 err = bpf_map_charge_init(&htab->map.memory, cost);
1153 htab->buckets = bpf_map_area_alloc(htab->buckets_num *
1154 sizeof(struct bpf_shtab_bucket),
1155 htab->map.numa_node);
1156 if (!htab->buckets) {
1157 bpf_map_charge_finish(&htab->map.memory);
1162 for (i = 0; i < htab->buckets_num; i++) {
1163 INIT_HLIST_HEAD(&htab->buckets[i].head);
1164 raw_spin_lock_init(&htab->buckets[i].lock);
1170 return ERR_PTR(err);
1173 static void sock_hash_free(struct bpf_map *map)
1175 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1176 struct bpf_shtab_bucket *bucket;
1177 struct hlist_head unlink_list;
1178 struct bpf_shtab_elem *elem;
1179 struct hlist_node *node;
1182 /* After the sync no updates or deletes will be in-flight so it
1183 * is safe to walk map and remove entries without risking a race
1184 * in EEXIST update case.
1187 for (i = 0; i < htab->buckets_num; i++) {
1188 bucket = sock_hash_select_bucket(htab, i);
1190 /* We are racing with sock_hash_delete_from_link to
1191 * enter the spin-lock critical section. Every socket on
1192 * the list is still linked to sockhash. Since link
1193 * exists, psock exists and holds a ref to socket. That
1194 * lets us to grab a socket ref too.
1196 raw_spin_lock_bh(&bucket->lock);
1197 hlist_for_each_entry(elem, &bucket->head, node)
1198 sock_hold(elem->sk);
1199 hlist_move_list(&bucket->head, &unlink_list);
1200 raw_spin_unlock_bh(&bucket->lock);
1202 /* Process removed entries out of atomic context to
1203 * block for socket lock before deleting the psock's
1206 hlist_for_each_entry_safe(elem, node, &unlink_list, node) {
1207 hlist_del(&elem->node);
1208 lock_sock(elem->sk);
1210 sock_map_unref(elem->sk, elem);
1212 release_sock(elem->sk);
1214 sock_hash_free_elem(htab, elem);
1218 /* wait for psock readers accessing its map link */
1221 bpf_map_area_free(htab->buckets);
1225 static void *sock_hash_lookup_sys(struct bpf_map *map, void *key)
1229 if (map->value_size != sizeof(u64))
1230 return ERR_PTR(-ENOSPC);
1232 sk = __sock_hash_lookup_elem(map, key);
1234 return ERR_PTR(-ENOENT);
1236 __sock_gen_cookie(sk);
1237 return &sk->sk_cookie;
1240 static void *sock_hash_lookup(struct bpf_map *map, void *key)
1244 sk = __sock_hash_lookup_elem(map, key);
1247 if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
1252 static void sock_hash_release_progs(struct bpf_map *map)
1254 psock_progs_drop(&container_of(map, struct bpf_shtab, map)->progs);
1257 BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops,
1258 struct bpf_map *, map, void *, key, u64, flags)
1260 WARN_ON_ONCE(!rcu_read_lock_held());
1262 if (likely(sock_map_sk_is_suitable(sops->sk) &&
1263 sock_map_op_okay(sops)))
1264 return sock_hash_update_common(map, key, sops->sk, flags);
1268 const struct bpf_func_proto bpf_sock_hash_update_proto = {
1269 .func = bpf_sock_hash_update,
1272 .ret_type = RET_INTEGER,
1273 .arg1_type = ARG_PTR_TO_CTX,
1274 .arg2_type = ARG_CONST_MAP_PTR,
1275 .arg3_type = ARG_PTR_TO_MAP_KEY,
1276 .arg4_type = ARG_ANYTHING,
1279 BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb,
1280 struct bpf_map *, map, void *, key, u64, flags)
1282 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
1285 if (unlikely(flags & ~(BPF_F_INGRESS)))
1288 sk = __sock_hash_lookup_elem(map, key);
1289 if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1292 tcb->bpf.flags = flags;
1293 tcb->bpf.sk_redir = sk;
1297 const struct bpf_func_proto bpf_sk_redirect_hash_proto = {
1298 .func = bpf_sk_redirect_hash,
1300 .ret_type = RET_INTEGER,
1301 .arg1_type = ARG_PTR_TO_CTX,
1302 .arg2_type = ARG_CONST_MAP_PTR,
1303 .arg3_type = ARG_PTR_TO_MAP_KEY,
1304 .arg4_type = ARG_ANYTHING,
1307 BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg,
1308 struct bpf_map *, map, void *, key, u64, flags)
1312 if (unlikely(flags & ~(BPF_F_INGRESS)))
1315 sk = __sock_hash_lookup_elem(map, key);
1316 if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1324 const struct bpf_func_proto bpf_msg_redirect_hash_proto = {
1325 .func = bpf_msg_redirect_hash,
1327 .ret_type = RET_INTEGER,
1328 .arg1_type = ARG_PTR_TO_CTX,
1329 .arg2_type = ARG_CONST_MAP_PTR,
1330 .arg3_type = ARG_PTR_TO_MAP_KEY,
1331 .arg4_type = ARG_ANYTHING,
1334 struct sock_hash_seq_info {
1335 struct bpf_map *map;
1336 struct bpf_shtab *htab;
1340 static void *sock_hash_seq_find_next(struct sock_hash_seq_info *info,
1341 struct bpf_shtab_elem *prev_elem)
1343 const struct bpf_shtab *htab = info->htab;
1344 struct bpf_shtab_bucket *bucket;
1345 struct bpf_shtab_elem *elem;
1346 struct hlist_node *node;
1348 /* try to find next elem in the same bucket */
1350 node = rcu_dereference(hlist_next_rcu(&prev_elem->node));
1351 elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
1355 /* no more elements, continue in the next bucket */
1359 for (; info->bucket_id < htab->buckets_num; info->bucket_id++) {
1360 bucket = &htab->buckets[info->bucket_id];
1361 node = rcu_dereference(hlist_first_rcu(&bucket->head));
1362 elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
1370 static void *sock_hash_seq_start(struct seq_file *seq, loff_t *pos)
1373 struct sock_hash_seq_info *info = seq->private;
1378 /* pairs with sock_hash_seq_stop */
1380 return sock_hash_seq_find_next(info, NULL);
1383 static void *sock_hash_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1386 struct sock_hash_seq_info *info = seq->private;
1389 return sock_hash_seq_find_next(info, v);
1392 static int sock_hash_seq_show(struct seq_file *seq, void *v)
1395 struct sock_hash_seq_info *info = seq->private;
1396 struct bpf_iter__sockmap ctx = {};
1397 struct bpf_shtab_elem *elem = v;
1398 struct bpf_iter_meta meta;
1399 struct bpf_prog *prog;
1402 prog = bpf_iter_get_info(&meta, !elem);
1407 ctx.map = info->map;
1409 ctx.key = elem->key;
1413 return bpf_iter_run_prog(prog, &ctx);
1416 static void sock_hash_seq_stop(struct seq_file *seq, void *v)
1420 (void)sock_hash_seq_show(seq, NULL);
1422 /* pairs with sock_hash_seq_start */
1426 static const struct seq_operations sock_hash_seq_ops = {
1427 .start = sock_hash_seq_start,
1428 .next = sock_hash_seq_next,
1429 .stop = sock_hash_seq_stop,
1430 .show = sock_hash_seq_show,
1433 static int sock_hash_init_seq_private(void *priv_data,
1434 struct bpf_iter_aux_info *aux)
1436 struct sock_hash_seq_info *info = priv_data;
1438 bpf_map_inc_with_uref(aux->map);
1439 info->map = aux->map;
1440 info->htab = container_of(aux->map, struct bpf_shtab, map);
1444 static void sock_hash_fini_seq_private(void *priv_data)
1446 struct sock_hash_seq_info *info = priv_data;
1448 bpf_map_put_with_uref(info->map);
1451 static const struct bpf_iter_seq_info sock_hash_iter_seq_info = {
1452 .seq_ops = &sock_hash_seq_ops,
1453 .init_seq_private = sock_hash_init_seq_private,
1454 .fini_seq_private = sock_hash_fini_seq_private,
1455 .seq_priv_size = sizeof(struct sock_hash_seq_info),
1458 static int sock_hash_map_btf_id;
1459 const struct bpf_map_ops sock_hash_ops = {
1460 .map_meta_equal = bpf_map_meta_equal,
1461 .map_alloc = sock_hash_alloc,
1462 .map_free = sock_hash_free,
1463 .map_get_next_key = sock_hash_get_next_key,
1464 .map_update_elem = sock_map_update_elem,
1465 .map_delete_elem = sock_hash_delete_elem,
1466 .map_lookup_elem = sock_hash_lookup,
1467 .map_lookup_elem_sys_only = sock_hash_lookup_sys,
1468 .map_release_uref = sock_hash_release_progs,
1469 .map_check_btf = map_check_no_btf,
1470 .map_btf_name = "bpf_shtab",
1471 .map_btf_id = &sock_hash_map_btf_id,
1472 .iter_seq_info = &sock_hash_iter_seq_info,
1475 static struct sk_psock_progs *sock_map_progs(struct bpf_map *map)
1477 switch (map->map_type) {
1478 case BPF_MAP_TYPE_SOCKMAP:
1479 return &container_of(map, struct bpf_stab, map)->progs;
1480 case BPF_MAP_TYPE_SOCKHASH:
1481 return &container_of(map, struct bpf_shtab, map)->progs;
1489 int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
1490 struct bpf_prog *old, u32 which)
1492 struct sk_psock_progs *progs = sock_map_progs(map);
1493 struct bpf_prog **pprog;
1499 case BPF_SK_MSG_VERDICT:
1500 pprog = &progs->msg_parser;
1502 case BPF_SK_SKB_STREAM_PARSER:
1503 pprog = &progs->skb_parser;
1505 case BPF_SK_SKB_STREAM_VERDICT:
1506 pprog = &progs->skb_verdict;
1513 return psock_replace_prog(pprog, prog, old);
1515 psock_set_prog(pprog, prog);
1519 static void sock_map_unlink(struct sock *sk, struct sk_psock_link *link)
1521 switch (link->map->map_type) {
1522 case BPF_MAP_TYPE_SOCKMAP:
1523 return sock_map_delete_from_link(link->map, sk,
1525 case BPF_MAP_TYPE_SOCKHASH:
1526 return sock_hash_delete_from_link(link->map, sk,
1533 static void sock_map_remove_links(struct sock *sk, struct sk_psock *psock)
1535 struct sk_psock_link *link;
1537 while ((link = sk_psock_link_pop(psock))) {
1538 sock_map_unlink(sk, link);
1539 sk_psock_free_link(link);
1543 void sock_map_unhash(struct sock *sk)
1545 void (*saved_unhash)(struct sock *sk);
1546 struct sk_psock *psock;
1549 psock = sk_psock(sk);
1550 if (unlikely(!psock)) {
1552 if (sk->sk_prot->unhash)
1553 sk->sk_prot->unhash(sk);
1557 saved_unhash = psock->saved_unhash;
1558 sock_map_remove_links(sk, psock);
1563 void sock_map_close(struct sock *sk, long timeout)
1565 void (*saved_close)(struct sock *sk, long timeout);
1566 struct sk_psock *psock;
1570 psock = sk_psock(sk);
1571 if (unlikely(!psock)) {
1574 return sk->sk_prot->close(sk, timeout);
1577 saved_close = psock->saved_close;
1578 sock_map_remove_links(sk, psock);
1581 saved_close(sk, timeout);
1584 static int sock_map_iter_attach_target(struct bpf_prog *prog,
1585 union bpf_iter_link_info *linfo,
1586 struct bpf_iter_aux_info *aux)
1588 struct bpf_map *map;
1591 if (!linfo->map.map_fd)
1594 map = bpf_map_get_with_uref(linfo->map.map_fd);
1596 return PTR_ERR(map);
1598 if (map->map_type != BPF_MAP_TYPE_SOCKMAP &&
1599 map->map_type != BPF_MAP_TYPE_SOCKHASH)
1602 if (prog->aux->max_rdonly_access > map->key_size) {
1611 bpf_map_put_with_uref(map);
1615 static void sock_map_iter_detach_target(struct bpf_iter_aux_info *aux)
1617 bpf_map_put_with_uref(aux->map);
1620 static struct bpf_iter_reg sock_map_iter_reg = {
1621 .target = "sockmap",
1622 .attach_target = sock_map_iter_attach_target,
1623 .detach_target = sock_map_iter_detach_target,
1624 .show_fdinfo = bpf_iter_map_show_fdinfo,
1625 .fill_link_info = bpf_iter_map_fill_link_info,
1626 .ctx_arg_info_size = 2,
1628 { offsetof(struct bpf_iter__sockmap, key),
1629 PTR_TO_RDONLY_BUF_OR_NULL },
1630 { offsetof(struct bpf_iter__sockmap, sk),
1631 PTR_TO_BTF_ID_OR_NULL },
1635 static int __init bpf_sockmap_iter_init(void)
1637 sock_map_iter_reg.ctx_arg_info[1].btf_id =
1638 btf_sock_ids[BTF_SOCK_TYPE_SOCK];
1639 return bpf_iter_reg_target(&sock_map_iter_reg);
1641 late_initcall(bpf_sockmap_iter_init);