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path: root/net/core/sock_map.c
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Diffstat (limited to 'net/core/sock_map.c')
-rw-r--r--net/core/sock_map.c466
1 files changed, 368 insertions, 98 deletions
diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index 22fa2c5bc6ec..5947b38e4f8b 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c
@@ -18,22 +18,28 @@ 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, u32 which);
+ 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;
- if (!capable(CAP_NET_ADMIN))
- return ERR_PTR(-EPERM);
if (attr->max_entries == 0 ||
attr->key_size != 4 ||
(attr->value_size != sizeof(u32) &&
@@ -46,7 +52,7 @@ static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
return ERR_PTR(-ENOMEM);
bpf_map_init_from_attr(&stab->map, attr);
- raw_spin_lock_init(&stab->lock);
+ spin_lock_init(&stab->lock);
stab->sks = bpf_map_area_alloc((u64) stab->map.max_entries *
sizeof(struct sock *),
@@ -61,55 +67,50 @@ static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog)
{
- u32 ufd = attr->target_fd;
struct bpf_map *map;
- struct fd f;
int ret;
if (attr->attach_flags || attr->replace_bpf_fd)
return -EINVAL;
- f = fdget(ufd);
+ 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, NULL, 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)
{
- u32 ufd = attr->target_fd;
struct bpf_prog *prog;
struct bpf_map *map;
- struct fd f;
int ret;
if (attr->attach_flags || attr->replace_bpf_fd)
return -EINVAL;
- f = fdget(ufd);
+ 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)) {
- ret = PTR_ERR(prog);
- goto put_map;
- }
+ if (IS_ERR(prog))
+ return PTR_ERR(prog);
if (prog->type != ptype) {
ret = -EINVAL;
goto put_prog;
}
- ret = sock_map_prog_update(map, NULL, prog, attr->attach_type);
+ 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);
-put_map:
- fdput(f);
return ret;
}
@@ -117,7 +118,6 @@ static void sock_map_sk_acquire(struct sock *sk)
__acquires(&sk->sk_lock.slock)
{
lock_sock(sk);
- preempt_disable();
rcu_read_lock();
}
@@ -125,7 +125,6 @@ static void sock_map_sk_release(struct sock *sk)
__releases(&sk->sk_lock.slock)
{
rcu_read_unlock();
- preempt_enable();
release_sock(sk);
}
@@ -150,16 +149,17 @@ static void sock_map_del_link(struct sock *sk,
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->saved_data_ready && stab->progs.stream_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 && stab->progs.stream_verdict)
+ if (psock->saved_data_ready && progs->stream_verdict)
verdict_stop = true;
- if (psock->saved_data_ready && stab->progs.skb_verdict)
+ 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);
@@ -303,7 +303,10 @@ static int sock_map_link(struct bpf_map *map, struct sock *sk)
write_lock_bh(&sk->sk_callback_lock);
if (stream_parser && stream_verdict && !psock->saved_data_ready) {
- ret = sk_psock_init_strp(sk, psock);
+ if (sk_is_tcp(sk))
+ ret = sk_psock_init_strp(sk, psock);
+ else
+ ret = -EOPNOTSUPP;
if (ret) {
write_unlock_bh(&sk->sk_callback_lock);
sk_psock_put(sk, psock);
@@ -412,12 +415,11 @@ static void *sock_map_lookup_sys(struct bpf_map *map, void *key)
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)
+ spin_lock_bh(&stab->lock);
+ if (!sk_test || sk_test == *psk)
sk = xchg(psk, NULL);
if (likely(sk))
@@ -425,7 +427,7 @@ static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test,
else
err = -EINVAL;
- raw_spin_unlock_bh(&stab->lock);
+ spin_unlock_bh(&stab->lock);
return err;
}
@@ -437,7 +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;
@@ -491,7 +493,7 @@ static int sock_map_update_common(struct bpf_map *map, u32 idx,
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;
@@ -505,10 +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:
@@ -540,6 +542,11 @@ 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;
}
@@ -587,8 +594,8 @@ out:
return ret;
}
-static int sock_map_update_elem(struct bpf_map *map, void *key,
- void *value, u64 flags)
+static long sock_map_update_elem(struct bpf_map *map, void *key,
+ void *value, u64 flags)
{
struct sock *sk = (struct sock *)value;
int ret;
@@ -646,6 +653,8 @@ BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb,
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;
@@ -672,6 +681,10 @@ BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg,
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;
@@ -797,6 +810,14 @@ static void sock_map_fini_seq_private(void *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,
@@ -816,6 +837,7 @@ const struct bpf_map_ops sock_map_ops = {
.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,
};
@@ -830,7 +852,7 @@ struct bpf_shtab_elem {
struct bpf_shtab_bucket {
struct hlist_head head;
- raw_spinlock_t lock;
+ spinlock_t lock;
};
struct bpf_shtab {
@@ -905,7 +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) {
@@ -913,10 +935,10 @@ 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_shtab *htab = container_of(map, struct bpf_shtab, map);
u32 hash, key_size = map->key_size;
@@ -927,7 +949,7 @@ static int sock_hash_delete_elem(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) {
hlist_del_rcu(&elem->node);
@@ -935,7 +957,7 @@ 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;
}
@@ -995,7 +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;
@@ -1021,10 +1043,10 @@ 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);
@@ -1076,8 +1098,6 @@ static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
struct bpf_shtab *htab;
int i, err;
- if (!capable(CAP_NET_ADMIN))
- return ERR_PTR(-EPERM);
if (attr->max_entries == 0 ||
attr->key_size == 0 ||
(attr->value_size != sizeof(u32) &&
@@ -1112,7 +1132,7 @@ 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;
@@ -1144,11 +1164,11 @@ static void sock_hash_free(struct bpf_map *map)
* exists, psock exists and holds a ref to socket. That
* lets us to grab a socket ref too.
*/
- raw_spin_lock_bh(&bucket->lock);
+ spin_lock_bh(&bucket->lock);
hlist_for_each_entry(elem, &bucket->head, node)
sock_hold(elem->sk);
hlist_move_list(&bucket->head, &unlink_list);
- raw_spin_unlock_bh(&bucket->lock);
+ spin_unlock_bh(&bucket->lock);
/* Process removed entries out of atomic context to
* block for socket lock before deleting the psock's
@@ -1164,6 +1184,7 @@ static void sock_hash_free(struct bpf_map *map)
sock_put(elem->sk);
sock_hash_free_elem(htab, elem);
}
+ cond_resched();
}
/* wait for psock readers accessing its map link */
@@ -1238,6 +1259,8 @@ BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb,
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;
@@ -1264,6 +1287,10 @@ BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg,
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;
@@ -1397,6 +1424,16 @@ static void sock_hash_fini_seq_private(void *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,
@@ -1416,6 +1453,7 @@ const struct bpf_map_ops sock_hash_ops = {
.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,
};
@@ -1434,80 +1472,108 @@ static struct sk_psock_progs *sock_map_progs(struct bpf_map *map)
return NULL;
}
-static int sock_map_prog_lookup(struct bpf_map *map, struct bpf_prog ***pprog,
- 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:
- *pprog = &progs->msg_parser;
+ 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:
- *pprog = &progs->stream_parser;
+ cur_pprog = &progs->stream_parser;
+ cur_plink = &progs->stream_parser_link;
break;
#endif
case BPF_SK_SKB_STREAM_VERDICT:
if (progs->skb_verdict)
return -EBUSY;
- *pprog = &progs->stream_verdict;
+ cur_pprog = &progs->stream_verdict;
+ cur_plink = &progs->stream_verdict_link;
break;
case BPF_SK_SKB_VERDICT:
if (progs->stream_verdict)
return -EBUSY;
- *pprog = &progs->skb_verdict;
+ 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;
}
+/* 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, u32 which)
+ struct bpf_prog *old, struct bpf_link *link,
+ u32 which)
{
struct bpf_prog **pprog;
+ struct bpf_link **plink;
int ret;
- ret = sock_map_prog_lookup(map, &pprog, which);
+ ret = sock_map_prog_link_lookup(map, &pprog, &plink, which);
if (ret)
return ret;
- if (old)
- return psock_replace_prog(pprog, prog, old);
+ /* for prog_attach/prog_detach/link_attach, return error if a bpf_link
+ * exists for that prog.
+ */
+ if ((!link || prog) && *plink)
+ return -EBUSY;
- psock_set_prog(pprog, prog);
- return 0;
+ 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, ufd = attr->target_fd;
+ u32 prog_cnt = 0, flags = 0;
struct bpf_prog **pprog;
struct bpf_prog *prog;
struct bpf_map *map;
- struct fd f;
u32 id = 0;
int ret;
if (attr->query.query_flags)
return -EINVAL;
- f = fdget(ufd);
+ 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_lookup(map, &pprog, attr->query.attach_type);
+ ret = sock_map_prog_link_lookup(map, &pprog, NULL, attr->query.attach_type);
if (ret)
goto end;
@@ -1532,7 +1598,6 @@ end:
copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt)))
ret = -EFAULT;
- fdput(f);
return ret;
}
@@ -1569,15 +1634,16 @@ void sock_map_unhash(struct sock *sk)
psock = sk_psock(sk);
if (unlikely(!psock)) {
rcu_read_unlock();
- if (sk->sk_prot->unhash)
- sk->sk_prot->unhash(sk);
- return;
+ saved_unhash = READ_ONCE(sk->sk_prot)->unhash;
+ } else {
+ saved_unhash = psock->saved_unhash;
+ sock_map_remove_links(sk, psock);
+ rcu_read_unlock();
}
-
- saved_unhash = psock->saved_unhash;
- sock_map_remove_links(sk, psock);
- rcu_read_unlock();
- saved_unhash(sk);
+ if (WARN_ON_ONCE(saved_unhash == sock_map_unhash))
+ return;
+ if (saved_unhash)
+ saved_unhash(sk);
}
EXPORT_SYMBOL_GPL(sock_map_unhash);
@@ -1590,17 +1656,18 @@ void sock_map_destroy(struct sock *sk)
psock = sk_psock_get(sk);
if (unlikely(!psock)) {
rcu_read_unlock();
- if (sk->sk_prot->destroy)
- sk->sk_prot->destroy(sk);
- return;
+ 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);
}
-
- saved_destroy = psock->saved_destroy;
- sock_map_remove_links(sk, psock);
- rcu_read_unlock();
- sk_psock_stop(psock);
- sk_psock_put(sk, psock);
- saved_destroy(sk);
+ if (WARN_ON_ONCE(saved_destroy == sock_map_destroy))
+ return;
+ if (saved_destroy)
+ saved_destroy(sk);
}
EXPORT_SYMBOL_GPL(sock_map_destroy);
@@ -1611,24 +1678,227 @@ void sock_map_close(struct sock *sk, long timeout)
lock_sock(sk);
rcu_read_lock();
- psock = sk_psock_get(sk);
- if (unlikely(!psock)) {
+ 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);
- return sk->sk_prot->close(sk, timeout);
}
- saved_close = psock->saved_close;
- sock_map_remove_links(sk, psock);
- rcu_read_unlock();
- sk_psock_stop(psock);
- release_sock(sk);
- cancel_work_sync(&psock->work);
- sk_psock_put(sk, psock);
+ /* Make sure we do not recurse. This is a bug.
+ * Leak the socket instead of crashing on a stack overflow.
+ */
+ if (WARN_ON_ONCE(saved_close == sock_map_close))
+ return;
saved_close(sk, timeout);
}
EXPORT_SYMBOL_GPL(sock_map_close);
+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)
generated by cgit (git 2.34.1) at 2025-12-21 18:32:51 +0000