diff options
| -rw-r--r-- | include/net/tcp.h | 13 | ||||
| -rw-r--r-- | net/core/sock.c | 1 | ||||
| -rw-r--r-- | net/ipv4/tcp_input.c | 8 | ||||
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 6 | ||||
| -rw-r--r-- | net/ipv6/tcp_ipv6.c | 4 |
5 files changed, 24 insertions, 8 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index a23282996ca9..74d3ed5eb219 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1836,4 +1836,17 @@ static inline void tcp_segs_in(struct tcp_sock *tp, const struct sk_buff *skb) tp->data_segs_in += segs_in; } +/* + * TCP listen path runs lockless. + * We forced "struct sock" to be const qualified to make sure + * we don't modify one of its field by mistake. + * Here, we increment sk_drops which is an atomic_t, so we can safely + * make sock writable again. + */ +static inline void tcp_listendrop(const struct sock *sk) +{ + atomic_inc(&((struct sock *)sk)->sk_drops); + NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); +} + #endif /* _TCP_H */ diff --git a/net/core/sock.c b/net/core/sock.c index 7a6a063b28b3..2f517ea56786 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1525,6 +1525,7 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority) newsk->sk_dst_cache = NULL; newsk->sk_wmem_queued = 0; newsk->sk_forward_alloc = 0; + atomic_set(&newsk->sk_drops, 0); newsk->sk_send_head = NULL; newsk->sk_userlocks = sk->sk_userlocks & ~SOCK_BINDPORT_LOCK; diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 0ffcd07e3409..983f04c11177 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -6339,8 +6339,10 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT); af_ops->send_synack(sk, dst, &fl, req, &foc, !want_cookie); - if (want_cookie) - goto drop_and_free; + if (want_cookie) { + reqsk_free(req); + return 0; + } } reqsk_put(req); return 0; @@ -6350,7 +6352,7 @@ drop_and_release: drop_and_free: reqsk_free(req); drop: - NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); + tcp_listendrop(sk); return 0; } EXPORT_SYMBOL(tcp_conn_request); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 059a98f5e7e1..f3ce0afe70aa 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -329,7 +329,7 @@ void tcp_req_err(struct sock *sk, u32 seq, bool abort) * errors returned from accept(). */ inet_csk_reqsk_queue_drop(req->rsk_listener, req); - NET_INC_STATS_BH(net, LINUX_MIB_LISTENDROPS); + tcp_listendrop(req->rsk_listener); } reqsk_put(req); } @@ -1246,7 +1246,7 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) &tcp_request_sock_ipv4_ops, sk, skb); drop: - NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); + tcp_listendrop(sk); return 0; } EXPORT_SYMBOL(tcp_v4_conn_request); @@ -1348,7 +1348,7 @@ exit_overflow: exit_nonewsk: dst_release(dst); exit: - NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); + tcp_listendrop(sk); return NULL; put_and_exit: inet_csk_prepare_forced_close(newsk); diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 5fa8fea394c9..7cde1b6fdda3 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -964,7 +964,7 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb) &tcp_request_sock_ipv6_ops, sk, skb); drop: - NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); + tcp_listendrop(sk); return 0; /* don't send reset */ } @@ -1169,7 +1169,7 @@ out_overflow: out_nonewsk: dst_release(dst); out: - NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); + tcp_listendrop(sk); return NULL; } |