diff options
| author | Eric Dumazet <edumazet@google.com> | 2015-10-13 17:12:54 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-10-13 18:26:34 -0700 |
| commit | 4bdc3d66147b3a623b32216a45431d0cff005f50 (patch) | |
| tree | 2e3f5a76b0e11c05cd1e9e88f5ab0c5cc1efe344 /net/dccp | |
| parent | bbb300eb976b613a8e4e666d3af39f5ab1031d22 (diff) | |
| download | linux-4bdc3d66147b3a623b32216a45431d0cff005f50.tar.gz | |
tcp/dccp: fix behavior of stale SYN_RECV request sockets
When a TCP/DCCP listener is closed, its pending SYN_RECV request sockets
become stale, meaning 3WHS can not complete.
But current behavior is wrong :
incoming packets finding such stale sockets are dropped.
We need instead to cleanup the request socket and perform another
lookup :
- Incoming ACK will give a RST answer,
- SYN rtx might find another listener if available.
- We expedite cleanup of request sockets and old listener socket.
Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dccp')
| -rw-r--r-- | net/dccp/ipv4.c | 15 | ||||
| -rw-r--r-- | net/dccp/ipv6.c | 15 |
2 files changed, 14 insertions, 16 deletions
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c index 8e99681c8189..0dcf1963b323 100644 --- a/net/dccp/ipv4.c +++ b/net/dccp/ipv4.c @@ -799,15 +799,10 @@ static int dccp_v4_rcv(struct sk_buff *skb) DCCP_SKB_CB(skb)->dccpd_ack_seq); } - /* Step 2: - * Look up flow ID in table and get corresponding socket */ +lookup: sk = __inet_lookup_skb(&dccp_hashinfo, skb, dh->dccph_sport, dh->dccph_dport); - /* - * Step 2: - * If no socket ... - */ - if (sk == NULL) { + if (!sk) { dccp_pr_debug("failed to look up flow ID in table and " "get corresponding socket\n"); goto no_dccp_socket; @@ -830,8 +825,12 @@ static int dccp_v4_rcv(struct sk_buff *skb) struct sock *nsk = NULL; sk = req->rsk_listener; - if (sk->sk_state == DCCP_LISTEN) + if (likely(sk->sk_state == DCCP_LISTEN)) { nsk = dccp_check_req(sk, skb, req); + } else { + inet_csk_reqsk_queue_drop(sk, req); + goto lookup; + } if (!nsk) { reqsk_put(req); goto discard_it; diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c index aed314f8c7c6..68831931b1fe 100644 --- a/net/dccp/ipv6.c +++ b/net/dccp/ipv6.c @@ -656,16 +656,11 @@ static int dccp_v6_rcv(struct sk_buff *skb) else DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb); - /* Step 2: - * Look up flow ID in table and get corresponding socket */ +lookup: sk = __inet6_lookup_skb(&dccp_hashinfo, skb, dh->dccph_sport, dh->dccph_dport, inet6_iif(skb)); - /* - * Step 2: - * If no socket ... - */ - if (sk == NULL) { + if (!sk) { dccp_pr_debug("failed to look up flow ID in table and " "get corresponding socket\n"); goto no_dccp_socket; @@ -688,8 +683,12 @@ static int dccp_v6_rcv(struct sk_buff *skb) struct sock *nsk = NULL; sk = req->rsk_listener; - if (sk->sk_state == DCCP_LISTEN) + if (likely(sk->sk_state == DCCP_LISTEN)) { nsk = dccp_check_req(sk, skb, req); + } else { + inet_csk_reqsk_queue_drop(sk, req); + goto lookup; + } if (!nsk) { reqsk_put(req); goto discard_it; |