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Diffstat (limited to 'kernel/bpf/sockmap.c')
-rw-r--r--kernel/bpf/sockmap.c187
1 files changed, 115 insertions, 72 deletions
diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
index 0314d1783d77..48c33417d13c 100644
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -86,9 +86,10 @@ struct smap_psock {
struct work_struct tx_work;
struct work_struct gc_work;
+ struct proto *sk_proto;
+ void (*save_close)(struct sock *sk, long timeout);
void (*save_data_ready)(struct sock *sk);
void (*save_write_space)(struct sock *sk);
- void (*save_state_change)(struct sock *sk);
};
static inline struct smap_psock *smap_psock_sk(const struct sock *sk)
@@ -96,12 +97,102 @@ static inline struct smap_psock *smap_psock_sk(const struct sock *sk)
return rcu_dereference_sk_user_data(sk);
}
+static struct proto tcp_bpf_proto;
+static int bpf_tcp_init(struct sock *sk)
+{
+ struct smap_psock *psock;
+
+ rcu_read_lock();
+ psock = smap_psock_sk(sk);
+ if (unlikely(!psock)) {
+ rcu_read_unlock();
+ return -EINVAL;
+ }
+
+ if (unlikely(psock->sk_proto)) {
+ rcu_read_unlock();
+ return -EBUSY;
+ }
+
+ psock->save_close = sk->sk_prot->close;
+ psock->sk_proto = sk->sk_prot;
+ sk->sk_prot = &tcp_bpf_proto;
+ rcu_read_unlock();
+ return 0;
+}
+
+static void bpf_tcp_release(struct sock *sk)
+{
+ struct smap_psock *psock;
+
+ rcu_read_lock();
+ psock = smap_psock_sk(sk);
+
+ if (likely(psock)) {
+ sk->sk_prot = psock->sk_proto;
+ psock->sk_proto = NULL;
+ }
+ rcu_read_unlock();
+}
+
+static void smap_release_sock(struct smap_psock *psock, struct sock *sock);
+
+static void bpf_tcp_close(struct sock *sk, long timeout)
+{
+ void (*close_fun)(struct sock *sk, long timeout);
+ struct smap_psock_map_entry *e, *tmp;
+ struct smap_psock *psock;
+ struct sock *osk;
+
+ rcu_read_lock();
+ psock = smap_psock_sk(sk);
+ if (unlikely(!psock)) {
+ rcu_read_unlock();
+ return sk->sk_prot->close(sk, timeout);
+ }
+
+ /* The psock may be destroyed anytime after exiting the RCU critial
+ * section so by the time we use close_fun the psock may no longer
+ * be valid. However, bpf_tcp_close is called with the sock lock
+ * held so the close hook and sk are still valid.
+ */
+ close_fun = psock->save_close;
+
+ write_lock_bh(&sk->sk_callback_lock);
+ list_for_each_entry_safe(e, tmp, &psock->maps, list) {
+ osk = cmpxchg(e->entry, sk, NULL);
+ if (osk == sk) {
+ list_del(&e->list);
+ smap_release_sock(psock, sk);
+ }
+ }
+ write_unlock_bh(&sk->sk_callback_lock);
+ rcu_read_unlock();
+ close_fun(sk, timeout);
+}
+
enum __sk_action {
__SK_DROP = 0,
__SK_PASS,
__SK_REDIRECT,
};
+static struct tcp_ulp_ops bpf_tcp_ulp_ops __read_mostly = {
+ .name = "bpf_tcp",
+ .uid = TCP_ULP_BPF,
+ .user_visible = false,
+ .owner = NULL,
+ .init = bpf_tcp_init,
+ .release = bpf_tcp_release,
+};
+
+static int bpf_tcp_ulp_register(void)
+{
+ tcp_bpf_proto = tcp_prot;
+ tcp_bpf_proto.close = bpf_tcp_close;
+ return tcp_register_ulp(&bpf_tcp_ulp_ops);
+}
+
static int smap_verdict_func(struct smap_psock *psock, struct sk_buff *skb)
{
struct bpf_prog *prog = READ_ONCE(psock->bpf_verdict);
@@ -166,68 +257,6 @@ static void smap_report_sk_error(struct smap_psock *psock, int err)
sk->sk_error_report(sk);
}
-static void smap_release_sock(struct smap_psock *psock, struct sock *sock);
-
-/* Called with lock_sock(sk) held */
-static void smap_state_change(struct sock *sk)
-{
- struct smap_psock_map_entry *e, *tmp;
- struct smap_psock *psock;
- struct socket_wq *wq;
- struct sock *osk;
-
- rcu_read_lock();
-
- /* Allowing transitions into an established syn_recv states allows
- * for early binding sockets to a smap object before the connection
- * is established.
- */
- switch (sk->sk_state) {
- case TCP_SYN_SENT:
- case TCP_SYN_RECV:
- case TCP_ESTABLISHED:
- break;
- case TCP_CLOSE_WAIT:
- case TCP_CLOSING:
- case TCP_LAST_ACK:
- case TCP_FIN_WAIT1:
- case TCP_FIN_WAIT2:
- case TCP_LISTEN:
- break;
- case TCP_CLOSE:
- /* Only release if the map entry is in fact the sock in
- * question. There is a case where the operator deletes
- * the sock from the map, but the TCP sock is closed before
- * the psock is detached. Use cmpxchg to verify correct
- * sock is removed.
- */
- psock = smap_psock_sk(sk);
- if (unlikely(!psock))
- break;
- write_lock_bh(&sk->sk_callback_lock);
- list_for_each_entry_safe(e, tmp, &psock->maps, list) {
- osk = cmpxchg(e->entry, sk, NULL);
- if (osk == sk) {
- list_del(&e->list);
- smap_release_sock(psock, sk);
- }
- }
- write_unlock_bh(&sk->sk_callback_lock);
- break;
- default:
- psock = smap_psock_sk(sk);
- if (unlikely(!psock))
- break;
- smap_report_sk_error(psock, EPIPE);
- break;
- }
-
- wq = rcu_dereference(sk->sk_wq);
- if (skwq_has_sleeper(wq))
- wake_up_interruptible_all(&wq->wait);
- rcu_read_unlock();
-}
-
static void smap_read_sock_strparser(struct strparser *strp,
struct sk_buff *skb)
{
@@ -322,10 +351,8 @@ static void smap_stop_sock(struct smap_psock *psock, struct sock *sk)
return;
sk->sk_data_ready = psock->save_data_ready;
sk->sk_write_space = psock->save_write_space;
- sk->sk_state_change = psock->save_state_change;
psock->save_data_ready = NULL;
psock->save_write_space = NULL;
- psock->save_state_change = NULL;
strp_stop(&psock->strp);
psock->strp_enabled = false;
}
@@ -350,6 +377,7 @@ static void smap_release_sock(struct smap_psock *psock, struct sock *sock)
if (psock->refcnt)
return;
+ tcp_cleanup_ulp(sock);
smap_stop_sock(psock, sock);
clear_bit(SMAP_TX_RUNNING, &psock->state);
rcu_assign_sk_user_data(sock, NULL);
@@ -427,10 +455,8 @@ static void smap_start_sock(struct smap_psock *psock, struct sock *sk)
return;
psock->save_data_ready = sk->sk_data_ready;
psock->save_write_space = sk->sk_write_space;
- psock->save_state_change = sk->sk_state_change;
sk->sk_data_ready = smap_data_ready;
sk->sk_write_space = smap_write_space;
- sk->sk_state_change = smap_state_change;
psock->strp_enabled = true;
}
@@ -509,6 +535,10 @@ static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
if (attr->value_size > KMALLOC_MAX_SIZE)
return ERR_PTR(-E2BIG);
+ err = bpf_tcp_ulp_register();
+ if (err && err != -EEXIST)
+ return ERR_PTR(err);
+
stab = kzalloc(sizeof(*stab), GFP_USER);
if (!stab)
return ERR_PTR(-ENOMEM);
@@ -590,11 +620,6 @@ static void sock_map_free(struct bpf_map *map)
}
rcu_read_unlock();
- if (stab->bpf_verdict)
- bpf_prog_put(stab->bpf_verdict);
- if (stab->bpf_parse)
- bpf_prog_put(stab->bpf_parse);
-
sock_map_remove_complete(stab);
}
@@ -754,6 +779,10 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops,
goto out_progs;
}
+ err = tcp_set_ulp_id(sock, TCP_ULP_BPF);
+ if (err)
+ goto out_progs;
+
set_bit(SMAP_TX_RUNNING, &psock->state);
}
@@ -866,6 +895,19 @@ static int sock_map_update_elem(struct bpf_map *map,
return err;
}
+static void sock_map_release(struct bpf_map *map, struct file *map_file)
+{
+ struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
+ struct bpf_prog *orig;
+
+ orig = xchg(&stab->bpf_parse, NULL);
+ if (orig)
+ bpf_prog_put(orig);
+ orig = xchg(&stab->bpf_verdict, NULL);
+ if (orig)
+ bpf_prog_put(orig);
+}
+
const struct bpf_map_ops sock_map_ops = {
.map_alloc = sock_map_alloc,
.map_free = sock_map_free,
@@ -873,6 +915,7 @@ const struct bpf_map_ops sock_map_ops = {
.map_get_next_key = sock_map_get_next_key,
.map_update_elem = sock_map_update_elem,
.map_delete_elem = sock_map_delete_elem,
+ .map_release = sock_map_release,
};
BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, bpf_sock,

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