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;
31 if (!capable(CAP_NET_ADMIN))
32 return ERR_PTR(-EPERM);
33 if (attr->max_entries == 0 ||
34 attr->key_size != 4 ||
35 (attr->value_size != sizeof(u32) &&
36 attr->value_size != sizeof(u64)) ||
37 attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
38 return ERR_PTR(-EINVAL);
40 stab = kzalloc(sizeof(*stab), GFP_USER | __GFP_ACCOUNT);
42 return ERR_PTR(-ENOMEM);
44 bpf_map_init_from_attr(&stab->map, attr);
45 raw_spin_lock_init(&stab->lock);
47 stab->sks = bpf_map_area_alloc(stab->map.max_entries *
48 sizeof(struct sock *),
52 return ERR_PTR(-ENOMEM);
58 int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog)
60 u32 ufd = attr->target_fd;
65 if (attr->attach_flags || attr->replace_bpf_fd)
69 map = __bpf_map_get(f);
72 ret = sock_map_prog_update(map, prog, NULL, attr->attach_type);
77 int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
79 u32 ufd = attr->target_fd;
80 struct bpf_prog *prog;
85 if (attr->attach_flags || attr->replace_bpf_fd)
89 map = __bpf_map_get(f);
93 prog = bpf_prog_get(attr->attach_bpf_fd);
99 if (prog->type != ptype) {
104 ret = sock_map_prog_update(map, NULL, prog, attr->attach_type);
112 static void sock_map_sk_acquire(struct sock *sk)
113 __acquires(&sk->sk_lock.slock)
120 static void sock_map_sk_release(struct sock *sk)
121 __releases(&sk->sk_lock.slock)
128 static void sock_map_add_link(struct sk_psock *psock,
129 struct sk_psock_link *link,
130 struct bpf_map *map, void *link_raw)
132 link->link_raw = link_raw;
134 spin_lock_bh(&psock->link_lock);
135 list_add_tail(&link->list, &psock->link);
136 spin_unlock_bh(&psock->link_lock);
139 static void sock_map_del_link(struct sock *sk,
140 struct sk_psock *psock, void *link_raw)
142 bool strp_stop = false, verdict_stop = false;
143 struct sk_psock_link *link, *tmp;
145 spin_lock_bh(&psock->link_lock);
146 list_for_each_entry_safe(link, tmp, &psock->link, list) {
147 if (link->link_raw == link_raw) {
148 struct bpf_map *map = link->map;
149 struct bpf_stab *stab = container_of(map, struct bpf_stab,
151 if (psock->parser.enabled && stab->progs.skb_parser)
153 if (psock->parser.enabled && stab->progs.skb_verdict)
155 list_del(&link->list);
156 sk_psock_free_link(link);
159 spin_unlock_bh(&psock->link_lock);
160 if (strp_stop || verdict_stop) {
161 write_lock_bh(&sk->sk_callback_lock);
163 sk_psock_stop_strp(sk, psock);
165 sk_psock_stop_verdict(sk, psock);
166 write_unlock_bh(&sk->sk_callback_lock);
170 static void sock_map_unref(struct sock *sk, void *link_raw)
172 struct sk_psock *psock = sk_psock(sk);
175 sock_map_del_link(sk, psock, link_raw);
176 sk_psock_put(sk, psock);
180 static int sock_map_init_proto(struct sock *sk, struct sk_psock *psock)
184 switch (sk->sk_type) {
186 prot = tcp_bpf_get_proto(sk, psock);
190 prot = udp_bpf_get_proto(sk, psock);
198 return PTR_ERR(prot);
200 sk_psock_update_proto(sk, psock, prot);
204 static struct sk_psock *sock_map_psock_get_checked(struct sock *sk)
206 struct sk_psock *psock;
209 psock = sk_psock(sk);
211 if (sk->sk_prot->close != sock_map_close) {
212 psock = ERR_PTR(-EBUSY);
216 if (!refcount_inc_not_zero(&psock->refcnt))
217 psock = ERR_PTR(-EBUSY);
224 static int sock_map_link(struct bpf_map *map, struct sk_psock_progs *progs,
227 struct bpf_prog *msg_parser, *skb_parser, *skb_verdict;
228 struct sk_psock *psock;
231 skb_verdict = READ_ONCE(progs->skb_verdict);
233 skb_verdict = bpf_prog_inc_not_zero(skb_verdict);
234 if (IS_ERR(skb_verdict))
235 return PTR_ERR(skb_verdict);
238 skb_parser = READ_ONCE(progs->skb_parser);
240 skb_parser = bpf_prog_inc_not_zero(skb_parser);
241 if (IS_ERR(skb_parser)) {
242 ret = PTR_ERR(skb_parser);
243 goto out_put_skb_verdict;
247 msg_parser = READ_ONCE(progs->msg_parser);
249 msg_parser = bpf_prog_inc_not_zero(msg_parser);
250 if (IS_ERR(msg_parser)) {
251 ret = PTR_ERR(msg_parser);
252 goto out_put_skb_parser;
256 psock = sock_map_psock_get_checked(sk);
258 ret = PTR_ERR(psock);
263 if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) ||
264 (skb_parser && READ_ONCE(psock->progs.skb_parser)) ||
265 (skb_verdict && READ_ONCE(psock->progs.skb_verdict))) {
266 sk_psock_put(sk, psock);
271 psock = sk_psock_init(sk, map->numa_node);
273 ret = PTR_ERR(psock);
279 psock_set_prog(&psock->progs.msg_parser, msg_parser);
281 ret = sock_map_init_proto(sk, psock);
285 write_lock_bh(&sk->sk_callback_lock);
286 if (skb_parser && skb_verdict && !psock->parser.enabled) {
287 ret = sk_psock_init_strp(sk, psock);
289 goto out_unlock_drop;
290 psock_set_prog(&psock->progs.skb_verdict, skb_verdict);
291 psock_set_prog(&psock->progs.skb_parser, skb_parser);
292 sk_psock_start_strp(sk, psock);
293 } else if (!skb_parser && skb_verdict && !psock->parser.enabled) {
294 psock_set_prog(&psock->progs.skb_verdict, skb_verdict);
295 sk_psock_start_verdict(sk,psock);
297 write_unlock_bh(&sk->sk_callback_lock);
300 write_unlock_bh(&sk->sk_callback_lock);
302 sk_psock_put(sk, psock);
305 bpf_prog_put(msg_parser);
308 bpf_prog_put(skb_parser);
311 bpf_prog_put(skb_verdict);
315 static int sock_map_link_no_progs(struct bpf_map *map, struct sock *sk)
317 struct sk_psock *psock;
320 psock = sock_map_psock_get_checked(sk);
322 return PTR_ERR(psock);
325 psock = sk_psock_init(sk, map->numa_node);
327 return PTR_ERR(psock);
330 ret = sock_map_init_proto(sk, psock);
332 sk_psock_put(sk, psock);
336 static void sock_map_free(struct bpf_map *map)
338 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
341 /* After the sync no updates or deletes will be in-flight so it
342 * is safe to walk map and remove entries without risking a race
343 * in EEXIST update case.
346 for (i = 0; i < stab->map.max_entries; i++) {
347 struct sock **psk = &stab->sks[i];
350 sk = xchg(psk, NULL);
354 sock_map_unref(sk, psk);
360 /* wait for psock readers accessing its map link */
363 bpf_map_area_free(stab->sks);
367 static void sock_map_release_progs(struct bpf_map *map)
369 psock_progs_drop(&container_of(map, struct bpf_stab, map)->progs);
372 static struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
374 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
376 WARN_ON_ONCE(!rcu_read_lock_held());
378 if (unlikely(key >= map->max_entries))
380 return READ_ONCE(stab->sks[key]);
383 static void *sock_map_lookup(struct bpf_map *map, void *key)
387 sk = __sock_map_lookup_elem(map, *(u32 *)key);
390 if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
395 static void *sock_map_lookup_sys(struct bpf_map *map, void *key)
399 if (map->value_size != sizeof(u64))
400 return ERR_PTR(-ENOSPC);
402 sk = __sock_map_lookup_elem(map, *(u32 *)key);
404 return ERR_PTR(-ENOENT);
406 __sock_gen_cookie(sk);
407 return &sk->sk_cookie;
410 static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test,
416 raw_spin_lock_bh(&stab->lock);
418 if (!sk_test || sk_test == sk)
419 sk = xchg(psk, NULL);
422 sock_map_unref(sk, psk);
426 raw_spin_unlock_bh(&stab->lock);
430 static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk,
433 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
435 __sock_map_delete(stab, sk, link_raw);
438 static int sock_map_delete_elem(struct bpf_map *map, void *key)
440 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
444 if (unlikely(i >= map->max_entries))
448 return __sock_map_delete(stab, NULL, psk);
451 static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next)
453 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
454 u32 i = key ? *(u32 *)key : U32_MAX;
455 u32 *key_next = next;
457 if (i == stab->map.max_entries - 1)
459 if (i >= stab->map.max_entries)
466 static bool sock_map_redirect_allowed(const struct sock *sk);
468 static int sock_map_update_common(struct bpf_map *map, u32 idx,
469 struct sock *sk, u64 flags)
471 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
472 struct sk_psock_link *link;
473 struct sk_psock *psock;
477 WARN_ON_ONCE(!rcu_read_lock_held());
478 if (unlikely(flags > BPF_EXIST))
480 if (unlikely(idx >= map->max_entries))
483 link = sk_psock_init_link();
487 /* Only sockets we can redirect into/from in BPF need to hold
488 * refs to parser/verdict progs and have their sk_data_ready
489 * and sk_write_space callbacks overridden.
491 if (sock_map_redirect_allowed(sk))
492 ret = sock_map_link(map, &stab->progs, sk);
494 ret = sock_map_link_no_progs(map, sk);
498 psock = sk_psock(sk);
499 WARN_ON_ONCE(!psock);
501 raw_spin_lock_bh(&stab->lock);
502 osk = stab->sks[idx];
503 if (osk && flags == BPF_NOEXIST) {
506 } else if (!osk && flags == BPF_EXIST) {
511 sock_map_add_link(psock, link, map, &stab->sks[idx]);
514 sock_map_unref(osk, &stab->sks[idx]);
515 raw_spin_unlock_bh(&stab->lock);
518 raw_spin_unlock_bh(&stab->lock);
520 sk_psock_put(sk, psock);
522 sk_psock_free_link(link);
526 static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops)
528 return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB ||
529 ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB ||
530 ops->op == BPF_SOCK_OPS_TCP_LISTEN_CB;
533 static bool sk_is_tcp(const struct sock *sk)
535 return sk->sk_type == SOCK_STREAM &&
536 sk->sk_protocol == IPPROTO_TCP;
539 static bool sk_is_udp(const struct sock *sk)
541 return sk->sk_type == SOCK_DGRAM &&
542 sk->sk_protocol == IPPROTO_UDP;
545 static bool sock_map_redirect_allowed(const struct sock *sk)
547 return sk_is_tcp(sk) && sk->sk_state != TCP_LISTEN;
550 static bool sock_map_sk_is_suitable(const struct sock *sk)
552 return sk_is_tcp(sk) || sk_is_udp(sk);
555 static bool sock_map_sk_state_allowed(const struct sock *sk)
558 return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_LISTEN);
559 else if (sk_is_udp(sk))
560 return sk_hashed(sk);
565 static int sock_hash_update_common(struct bpf_map *map, void *key,
566 struct sock *sk, u64 flags);
568 int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value,
576 if (map->value_size == sizeof(u64))
583 sock = sockfd_lookup(ufd, &ret);
591 if (!sock_map_sk_is_suitable(sk)) {
596 sock_map_sk_acquire(sk);
597 if (!sock_map_sk_state_allowed(sk))
599 else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
600 ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
602 ret = sock_hash_update_common(map, key, sk, flags);
603 sock_map_sk_release(sk);
609 static int sock_map_update_elem(struct bpf_map *map, void *key,
610 void *value, u64 flags)
612 struct sock *sk = (struct sock *)value;
615 if (unlikely(!sk || !sk_fullsock(sk)))
618 if (!sock_map_sk_is_suitable(sk))
623 if (!sock_map_sk_state_allowed(sk))
625 else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
626 ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
628 ret = sock_hash_update_common(map, key, sk, flags);
634 BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops,
635 struct bpf_map *, map, void *, key, u64, flags)
637 WARN_ON_ONCE(!rcu_read_lock_held());
639 if (likely(sock_map_sk_is_suitable(sops->sk) &&
640 sock_map_op_okay(sops)))
641 return sock_map_update_common(map, *(u32 *)key, sops->sk,
646 const struct bpf_func_proto bpf_sock_map_update_proto = {
647 .func = bpf_sock_map_update,
650 .ret_type = RET_INTEGER,
651 .arg1_type = ARG_PTR_TO_CTX,
652 .arg2_type = ARG_CONST_MAP_PTR,
653 .arg3_type = ARG_PTR_TO_MAP_KEY,
654 .arg4_type = ARG_ANYTHING,
657 BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb,
658 struct bpf_map *, map, u32, key, u64, flags)
660 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
663 if (unlikely(flags & ~(BPF_F_INGRESS)))
666 sk = __sock_map_lookup_elem(map, key);
667 if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
670 tcb->bpf.flags = flags;
671 tcb->bpf.sk_redir = sk;
675 const struct bpf_func_proto bpf_sk_redirect_map_proto = {
676 .func = bpf_sk_redirect_map,
678 .ret_type = RET_INTEGER,
679 .arg1_type = ARG_PTR_TO_CTX,
680 .arg2_type = ARG_CONST_MAP_PTR,
681 .arg3_type = ARG_ANYTHING,
682 .arg4_type = ARG_ANYTHING,
685 BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg,
686 struct bpf_map *, map, u32, key, u64, flags)
690 if (unlikely(flags & ~(BPF_F_INGRESS)))
693 sk = __sock_map_lookup_elem(map, key);
694 if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
702 const struct bpf_func_proto bpf_msg_redirect_map_proto = {
703 .func = bpf_msg_redirect_map,
705 .ret_type = RET_INTEGER,
706 .arg1_type = ARG_PTR_TO_CTX,
707 .arg2_type = ARG_CONST_MAP_PTR,
708 .arg3_type = ARG_ANYTHING,
709 .arg4_type = ARG_ANYTHING,
712 struct sock_map_seq_info {
718 struct bpf_iter__sockmap {
719 __bpf_md_ptr(struct bpf_iter_meta *, meta);
720 __bpf_md_ptr(struct bpf_map *, map);
721 __bpf_md_ptr(void *, key);
722 __bpf_md_ptr(struct sock *, sk);
725 DEFINE_BPF_ITER_FUNC(sockmap, struct bpf_iter_meta *meta,
726 struct bpf_map *map, void *key,
729 static void *sock_map_seq_lookup_elem(struct sock_map_seq_info *info)
731 if (unlikely(info->index >= info->map->max_entries))
734 info->sk = __sock_map_lookup_elem(info->map, info->index);
736 /* can't return sk directly, since that might be NULL */
740 static void *sock_map_seq_start(struct seq_file *seq, loff_t *pos)
743 struct sock_map_seq_info *info = seq->private;
748 /* pairs with sock_map_seq_stop */
750 return sock_map_seq_lookup_elem(info);
753 static void *sock_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
756 struct sock_map_seq_info *info = seq->private;
761 return sock_map_seq_lookup_elem(info);
764 static int sock_map_seq_show(struct seq_file *seq, void *v)
767 struct sock_map_seq_info *info = seq->private;
768 struct bpf_iter__sockmap ctx = {};
769 struct bpf_iter_meta meta;
770 struct bpf_prog *prog;
773 prog = bpf_iter_get_info(&meta, !v);
780 ctx.key = &info->index;
784 return bpf_iter_run_prog(prog, &ctx);
787 static void sock_map_seq_stop(struct seq_file *seq, void *v)
791 (void)sock_map_seq_show(seq, NULL);
793 /* pairs with sock_map_seq_start */
797 static const struct seq_operations sock_map_seq_ops = {
798 .start = sock_map_seq_start,
799 .next = sock_map_seq_next,
800 .stop = sock_map_seq_stop,
801 .show = sock_map_seq_show,
804 static int sock_map_init_seq_private(void *priv_data,
805 struct bpf_iter_aux_info *aux)
807 struct sock_map_seq_info *info = priv_data;
809 info->map = aux->map;
813 static const struct bpf_iter_seq_info sock_map_iter_seq_info = {
814 .seq_ops = &sock_map_seq_ops,
815 .init_seq_private = sock_map_init_seq_private,
816 .seq_priv_size = sizeof(struct sock_map_seq_info),
819 static int sock_map_btf_id;
820 const struct bpf_map_ops sock_map_ops = {
821 .map_meta_equal = bpf_map_meta_equal,
822 .map_alloc = sock_map_alloc,
823 .map_free = sock_map_free,
824 .map_get_next_key = sock_map_get_next_key,
825 .map_lookup_elem_sys_only = sock_map_lookup_sys,
826 .map_update_elem = sock_map_update_elem,
827 .map_delete_elem = sock_map_delete_elem,
828 .map_lookup_elem = sock_map_lookup,
829 .map_release_uref = sock_map_release_progs,
830 .map_check_btf = map_check_no_btf,
831 .map_btf_name = "bpf_stab",
832 .map_btf_id = &sock_map_btf_id,
833 .iter_seq_info = &sock_map_iter_seq_info,
836 struct bpf_shtab_elem {
840 struct hlist_node node;
844 struct bpf_shtab_bucket {
845 struct hlist_head head;
851 struct bpf_shtab_bucket *buckets;
854 struct sk_psock_progs progs;
858 static inline u32 sock_hash_bucket_hash(const void *key, u32 len)
860 return jhash(key, len, 0);
863 static struct bpf_shtab_bucket *sock_hash_select_bucket(struct bpf_shtab *htab,
866 return &htab->buckets[hash & (htab->buckets_num - 1)];
869 static struct bpf_shtab_elem *
870 sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key,
873 struct bpf_shtab_elem *elem;
875 hlist_for_each_entry_rcu(elem, head, node) {
876 if (elem->hash == hash &&
877 !memcmp(&elem->key, key, key_size))
884 static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key)
886 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
887 u32 key_size = map->key_size, hash;
888 struct bpf_shtab_bucket *bucket;
889 struct bpf_shtab_elem *elem;
891 WARN_ON_ONCE(!rcu_read_lock_held());
893 hash = sock_hash_bucket_hash(key, key_size);
894 bucket = sock_hash_select_bucket(htab, hash);
895 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
897 return elem ? elem->sk : NULL;
900 static void sock_hash_free_elem(struct bpf_shtab *htab,
901 struct bpf_shtab_elem *elem)
903 atomic_dec(&htab->count);
904 kfree_rcu(elem, rcu);
907 static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk,
910 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
911 struct bpf_shtab_elem *elem_probe, *elem = link_raw;
912 struct bpf_shtab_bucket *bucket;
914 WARN_ON_ONCE(!rcu_read_lock_held());
915 bucket = sock_hash_select_bucket(htab, elem->hash);
917 /* elem may be deleted in parallel from the map, but access here
918 * is okay since it's going away only after RCU grace period.
919 * However, we need to check whether it's still present.
921 raw_spin_lock_bh(&bucket->lock);
922 elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash,
923 elem->key, map->key_size);
924 if (elem_probe && elem_probe == elem) {
925 hlist_del_rcu(&elem->node);
926 sock_map_unref(elem->sk, elem);
927 sock_hash_free_elem(htab, elem);
929 raw_spin_unlock_bh(&bucket->lock);
932 static int sock_hash_delete_elem(struct bpf_map *map, void *key)
934 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
935 u32 hash, key_size = map->key_size;
936 struct bpf_shtab_bucket *bucket;
937 struct bpf_shtab_elem *elem;
940 hash = sock_hash_bucket_hash(key, key_size);
941 bucket = sock_hash_select_bucket(htab, hash);
943 raw_spin_lock_bh(&bucket->lock);
944 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
946 hlist_del_rcu(&elem->node);
947 sock_map_unref(elem->sk, elem);
948 sock_hash_free_elem(htab, elem);
951 raw_spin_unlock_bh(&bucket->lock);
955 static struct bpf_shtab_elem *sock_hash_alloc_elem(struct bpf_shtab *htab,
956 void *key, u32 key_size,
957 u32 hash, struct sock *sk,
958 struct bpf_shtab_elem *old)
960 struct bpf_shtab_elem *new;
962 if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
964 atomic_dec(&htab->count);
965 return ERR_PTR(-E2BIG);
969 new = bpf_map_kmalloc_node(&htab->map, htab->elem_size,
970 GFP_ATOMIC | __GFP_NOWARN,
971 htab->map.numa_node);
973 atomic_dec(&htab->count);
974 return ERR_PTR(-ENOMEM);
976 memcpy(new->key, key, key_size);
982 static int sock_hash_update_common(struct bpf_map *map, void *key,
983 struct sock *sk, u64 flags)
985 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
986 u32 key_size = map->key_size, hash;
987 struct bpf_shtab_elem *elem, *elem_new;
988 struct bpf_shtab_bucket *bucket;
989 struct sk_psock_link *link;
990 struct sk_psock *psock;
993 WARN_ON_ONCE(!rcu_read_lock_held());
994 if (unlikely(flags > BPF_EXIST))
997 link = sk_psock_init_link();
1001 /* Only sockets we can redirect into/from in BPF need to hold
1002 * refs to parser/verdict progs and have their sk_data_ready
1003 * and sk_write_space callbacks overridden.
1005 if (sock_map_redirect_allowed(sk))
1006 ret = sock_map_link(map, &htab->progs, sk);
1008 ret = sock_map_link_no_progs(map, sk);
1012 psock = sk_psock(sk);
1013 WARN_ON_ONCE(!psock);
1015 hash = sock_hash_bucket_hash(key, key_size);
1016 bucket = sock_hash_select_bucket(htab, hash);
1018 raw_spin_lock_bh(&bucket->lock);
1019 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
1020 if (elem && flags == BPF_NOEXIST) {
1023 } else if (!elem && flags == BPF_EXIST) {
1028 elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem);
1029 if (IS_ERR(elem_new)) {
1030 ret = PTR_ERR(elem_new);
1034 sock_map_add_link(psock, link, map, elem_new);
1035 /* Add new element to the head of the list, so that
1036 * concurrent search will find it before old elem.
1038 hlist_add_head_rcu(&elem_new->node, &bucket->head);
1040 hlist_del_rcu(&elem->node);
1041 sock_map_unref(elem->sk, elem);
1042 sock_hash_free_elem(htab, elem);
1044 raw_spin_unlock_bh(&bucket->lock);
1047 raw_spin_unlock_bh(&bucket->lock);
1048 sk_psock_put(sk, psock);
1050 sk_psock_free_link(link);
1054 static int sock_hash_get_next_key(struct bpf_map *map, void *key,
1057 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1058 struct bpf_shtab_elem *elem, *elem_next;
1059 u32 hash, key_size = map->key_size;
1060 struct hlist_head *head;
1064 goto find_first_elem;
1065 hash = sock_hash_bucket_hash(key, key_size);
1066 head = &sock_hash_select_bucket(htab, hash)->head;
1067 elem = sock_hash_lookup_elem_raw(head, hash, key, key_size);
1069 goto find_first_elem;
1071 elem_next = hlist_entry_safe(rcu_dereference(hlist_next_rcu(&elem->node)),
1072 struct bpf_shtab_elem, node);
1074 memcpy(key_next, elem_next->key, key_size);
1078 i = hash & (htab->buckets_num - 1);
1081 for (; i < htab->buckets_num; i++) {
1082 head = &sock_hash_select_bucket(htab, i)->head;
1083 elem_next = hlist_entry_safe(rcu_dereference(hlist_first_rcu(head)),
1084 struct bpf_shtab_elem, node);
1086 memcpy(key_next, elem_next->key, key_size);
1094 static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
1096 struct bpf_shtab *htab;
1099 if (!capable(CAP_NET_ADMIN))
1100 return ERR_PTR(-EPERM);
1101 if (attr->max_entries == 0 ||
1102 attr->key_size == 0 ||
1103 (attr->value_size != sizeof(u32) &&
1104 attr->value_size != sizeof(u64)) ||
1105 attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
1106 return ERR_PTR(-EINVAL);
1107 if (attr->key_size > MAX_BPF_STACK)
1108 return ERR_PTR(-E2BIG);
1110 htab = kzalloc(sizeof(*htab), GFP_USER | __GFP_ACCOUNT);
1112 return ERR_PTR(-ENOMEM);
1114 bpf_map_init_from_attr(&htab->map, attr);
1116 htab->buckets_num = roundup_pow_of_two(htab->map.max_entries);
1117 htab->elem_size = sizeof(struct bpf_shtab_elem) +
1118 round_up(htab->map.key_size, 8);
1119 if (htab->buckets_num == 0 ||
1120 htab->buckets_num > U32_MAX / sizeof(struct bpf_shtab_bucket)) {
1125 htab->buckets = bpf_map_area_alloc(htab->buckets_num *
1126 sizeof(struct bpf_shtab_bucket),
1127 htab->map.numa_node);
1128 if (!htab->buckets) {
1133 for (i = 0; i < htab->buckets_num; i++) {
1134 INIT_HLIST_HEAD(&htab->buckets[i].head);
1135 raw_spin_lock_init(&htab->buckets[i].lock);
1141 return ERR_PTR(err);
1144 static void sock_hash_free(struct bpf_map *map)
1146 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1147 struct bpf_shtab_bucket *bucket;
1148 struct hlist_head unlink_list;
1149 struct bpf_shtab_elem *elem;
1150 struct hlist_node *node;
1153 /* After the sync no updates or deletes will be in-flight so it
1154 * is safe to walk map and remove entries without risking a race
1155 * in EEXIST update case.
1158 for (i = 0; i < htab->buckets_num; i++) {
1159 bucket = sock_hash_select_bucket(htab, i);
1161 /* We are racing with sock_hash_delete_from_link to
1162 * enter the spin-lock critical section. Every socket on
1163 * the list is still linked to sockhash. Since link
1164 * exists, psock exists and holds a ref to socket. That
1165 * lets us to grab a socket ref too.
1167 raw_spin_lock_bh(&bucket->lock);
1168 hlist_for_each_entry(elem, &bucket->head, node)
1169 sock_hold(elem->sk);
1170 hlist_move_list(&bucket->head, &unlink_list);
1171 raw_spin_unlock_bh(&bucket->lock);
1173 /* Process removed entries out of atomic context to
1174 * block for socket lock before deleting the psock's
1177 hlist_for_each_entry_safe(elem, node, &unlink_list, node) {
1178 hlist_del(&elem->node);
1179 lock_sock(elem->sk);
1181 sock_map_unref(elem->sk, elem);
1183 release_sock(elem->sk);
1185 sock_hash_free_elem(htab, elem);
1189 /* wait for psock readers accessing its map link */
1192 bpf_map_area_free(htab->buckets);
1196 static void *sock_hash_lookup_sys(struct bpf_map *map, void *key)
1200 if (map->value_size != sizeof(u64))
1201 return ERR_PTR(-ENOSPC);
1203 sk = __sock_hash_lookup_elem(map, key);
1205 return ERR_PTR(-ENOENT);
1207 __sock_gen_cookie(sk);
1208 return &sk->sk_cookie;
1211 static void *sock_hash_lookup(struct bpf_map *map, void *key)
1215 sk = __sock_hash_lookup_elem(map, key);
1218 if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
1223 static void sock_hash_release_progs(struct bpf_map *map)
1225 psock_progs_drop(&container_of(map, struct bpf_shtab, map)->progs);
1228 BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops,
1229 struct bpf_map *, map, void *, key, u64, flags)
1231 WARN_ON_ONCE(!rcu_read_lock_held());
1233 if (likely(sock_map_sk_is_suitable(sops->sk) &&
1234 sock_map_op_okay(sops)))
1235 return sock_hash_update_common(map, key, sops->sk, flags);
1239 const struct bpf_func_proto bpf_sock_hash_update_proto = {
1240 .func = bpf_sock_hash_update,
1243 .ret_type = RET_INTEGER,
1244 .arg1_type = ARG_PTR_TO_CTX,
1245 .arg2_type = ARG_CONST_MAP_PTR,
1246 .arg3_type = ARG_PTR_TO_MAP_KEY,
1247 .arg4_type = ARG_ANYTHING,
1250 BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb,
1251 struct bpf_map *, map, void *, key, u64, flags)
1253 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
1256 if (unlikely(flags & ~(BPF_F_INGRESS)))
1259 sk = __sock_hash_lookup_elem(map, key);
1260 if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1263 tcb->bpf.flags = flags;
1264 tcb->bpf.sk_redir = sk;
1268 const struct bpf_func_proto bpf_sk_redirect_hash_proto = {
1269 .func = bpf_sk_redirect_hash,
1271 .ret_type = RET_INTEGER,
1272 .arg1_type = ARG_PTR_TO_CTX,
1273 .arg2_type = ARG_CONST_MAP_PTR,
1274 .arg3_type = ARG_PTR_TO_MAP_KEY,
1275 .arg4_type = ARG_ANYTHING,
1278 BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg,
1279 struct bpf_map *, map, void *, key, u64, flags)
1283 if (unlikely(flags & ~(BPF_F_INGRESS)))
1286 sk = __sock_hash_lookup_elem(map, key);
1287 if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1295 const struct bpf_func_proto bpf_msg_redirect_hash_proto = {
1296 .func = bpf_msg_redirect_hash,
1298 .ret_type = RET_INTEGER,
1299 .arg1_type = ARG_PTR_TO_CTX,
1300 .arg2_type = ARG_CONST_MAP_PTR,
1301 .arg3_type = ARG_PTR_TO_MAP_KEY,
1302 .arg4_type = ARG_ANYTHING,
1305 struct sock_hash_seq_info {
1306 struct bpf_map *map;
1307 struct bpf_shtab *htab;
1311 static void *sock_hash_seq_find_next(struct sock_hash_seq_info *info,
1312 struct bpf_shtab_elem *prev_elem)
1314 const struct bpf_shtab *htab = info->htab;
1315 struct bpf_shtab_bucket *bucket;
1316 struct bpf_shtab_elem *elem;
1317 struct hlist_node *node;
1319 /* try to find next elem in the same bucket */
1321 node = rcu_dereference(hlist_next_rcu(&prev_elem->node));
1322 elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
1326 /* no more elements, continue in the next bucket */
1330 for (; info->bucket_id < htab->buckets_num; info->bucket_id++) {
1331 bucket = &htab->buckets[info->bucket_id];
1332 node = rcu_dereference(hlist_first_rcu(&bucket->head));
1333 elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
1341 static void *sock_hash_seq_start(struct seq_file *seq, loff_t *pos)
1344 struct sock_hash_seq_info *info = seq->private;
1349 /* pairs with sock_hash_seq_stop */
1351 return sock_hash_seq_find_next(info, NULL);
1354 static void *sock_hash_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1357 struct sock_hash_seq_info *info = seq->private;
1360 return sock_hash_seq_find_next(info, v);
1363 static int sock_hash_seq_show(struct seq_file *seq, void *v)
1366 struct sock_hash_seq_info *info = seq->private;
1367 struct bpf_iter__sockmap ctx = {};
1368 struct bpf_shtab_elem *elem = v;
1369 struct bpf_iter_meta meta;
1370 struct bpf_prog *prog;
1373 prog = bpf_iter_get_info(&meta, !elem);
1378 ctx.map = info->map;
1380 ctx.key = elem->key;
1384 return bpf_iter_run_prog(prog, &ctx);
1387 static void sock_hash_seq_stop(struct seq_file *seq, void *v)
1391 (void)sock_hash_seq_show(seq, NULL);
1393 /* pairs with sock_hash_seq_start */
1397 static const struct seq_operations sock_hash_seq_ops = {
1398 .start = sock_hash_seq_start,
1399 .next = sock_hash_seq_next,
1400 .stop = sock_hash_seq_stop,
1401 .show = sock_hash_seq_show,
1404 static int sock_hash_init_seq_private(void *priv_data,
1405 struct bpf_iter_aux_info *aux)
1407 struct sock_hash_seq_info *info = priv_data;
1409 info->map = aux->map;
1410 info->htab = container_of(aux->map, struct bpf_shtab, map);
1414 static const struct bpf_iter_seq_info sock_hash_iter_seq_info = {
1415 .seq_ops = &sock_hash_seq_ops,
1416 .init_seq_private = sock_hash_init_seq_private,
1417 .seq_priv_size = sizeof(struct sock_hash_seq_info),
1420 static int sock_hash_map_btf_id;
1421 const struct bpf_map_ops sock_hash_ops = {
1422 .map_meta_equal = bpf_map_meta_equal,
1423 .map_alloc = sock_hash_alloc,
1424 .map_free = sock_hash_free,
1425 .map_get_next_key = sock_hash_get_next_key,
1426 .map_update_elem = sock_map_update_elem,
1427 .map_delete_elem = sock_hash_delete_elem,
1428 .map_lookup_elem = sock_hash_lookup,
1429 .map_lookup_elem_sys_only = sock_hash_lookup_sys,
1430 .map_release_uref = sock_hash_release_progs,
1431 .map_check_btf = map_check_no_btf,
1432 .map_btf_name = "bpf_shtab",
1433 .map_btf_id = &sock_hash_map_btf_id,
1434 .iter_seq_info = &sock_hash_iter_seq_info,
1437 static struct sk_psock_progs *sock_map_progs(struct bpf_map *map)
1439 switch (map->map_type) {
1440 case BPF_MAP_TYPE_SOCKMAP:
1441 return &container_of(map, struct bpf_stab, map)->progs;
1442 case BPF_MAP_TYPE_SOCKHASH:
1443 return &container_of(map, struct bpf_shtab, map)->progs;
1451 int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
1452 struct bpf_prog *old, u32 which)
1454 struct sk_psock_progs *progs = sock_map_progs(map);
1455 struct bpf_prog **pprog;
1461 case BPF_SK_MSG_VERDICT:
1462 pprog = &progs->msg_parser;
1464 case BPF_SK_SKB_STREAM_PARSER:
1465 pprog = &progs->skb_parser;
1467 case BPF_SK_SKB_STREAM_VERDICT:
1468 pprog = &progs->skb_verdict;
1475 return psock_replace_prog(pprog, prog, old);
1477 psock_set_prog(pprog, prog);
1481 static void sock_map_unlink(struct sock *sk, struct sk_psock_link *link)
1483 switch (link->map->map_type) {
1484 case BPF_MAP_TYPE_SOCKMAP:
1485 return sock_map_delete_from_link(link->map, sk,
1487 case BPF_MAP_TYPE_SOCKHASH:
1488 return sock_hash_delete_from_link(link->map, sk,
1495 static void sock_map_remove_links(struct sock *sk, struct sk_psock *psock)
1497 struct sk_psock_link *link;
1499 while ((link = sk_psock_link_pop(psock))) {
1500 sock_map_unlink(sk, link);
1501 sk_psock_free_link(link);
1505 void sock_map_unhash(struct sock *sk)
1507 void (*saved_unhash)(struct sock *sk);
1508 struct sk_psock *psock;
1511 psock = sk_psock(sk);
1512 if (unlikely(!psock)) {
1514 if (sk->sk_prot->unhash)
1515 sk->sk_prot->unhash(sk);
1519 saved_unhash = psock->saved_unhash;
1520 sock_map_remove_links(sk, psock);
1525 void sock_map_close(struct sock *sk, long timeout)
1527 void (*saved_close)(struct sock *sk, long timeout);
1528 struct sk_psock *psock;
1532 psock = sk_psock(sk);
1533 if (unlikely(!psock)) {
1536 return sk->sk_prot->close(sk, timeout);
1539 saved_close = psock->saved_close;
1540 sock_map_remove_links(sk, psock);
1543 saved_close(sk, timeout);
1546 static int sock_map_iter_attach_target(struct bpf_prog *prog,
1547 union bpf_iter_link_info *linfo,
1548 struct bpf_iter_aux_info *aux)
1550 struct bpf_map *map;
1553 if (!linfo->map.map_fd)
1556 map = bpf_map_get_with_uref(linfo->map.map_fd);
1558 return PTR_ERR(map);
1560 if (map->map_type != BPF_MAP_TYPE_SOCKMAP &&
1561 map->map_type != BPF_MAP_TYPE_SOCKHASH)
1564 if (prog->aux->max_rdonly_access > map->key_size) {
1573 bpf_map_put_with_uref(map);
1577 static void sock_map_iter_detach_target(struct bpf_iter_aux_info *aux)
1579 bpf_map_put_with_uref(aux->map);
1582 static struct bpf_iter_reg sock_map_iter_reg = {
1583 .target = "sockmap",
1584 .attach_target = sock_map_iter_attach_target,
1585 .detach_target = sock_map_iter_detach_target,
1586 .show_fdinfo = bpf_iter_map_show_fdinfo,
1587 .fill_link_info = bpf_iter_map_fill_link_info,
1588 .ctx_arg_info_size = 2,
1590 { offsetof(struct bpf_iter__sockmap, key),
1591 PTR_TO_RDONLY_BUF_OR_NULL },
1592 { offsetof(struct bpf_iter__sockmap, sk),
1593 PTR_TO_BTF_ID_OR_NULL },
1597 static int __init bpf_sockmap_iter_init(void)
1599 sock_map_iter_reg.ctx_arg_info[1].btf_id =
1600 btf_sock_ids[BTF_SOCK_TYPE_SOCK];
1601 return bpf_iter_reg_target(&sock_map_iter_reg);
1603 late_initcall(bpf_sockmap_iter_init);