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authorEric Dumazet <edumazet@google.com>2015-10-13 17:12:54 -0700
committerDavid S. Miller <davem@davemloft.net>2015-10-13 18:26:34 -0700
commit4bdc3d66147b3a623b32216a45431d0cff005f50 (patch)
tree2e3f5a76b0e11c05cd1e9e88f5ab0c5cc1efe344 /net/dccp
parentbbb300eb976b613a8e4e666d3af39f5ab1031d22 (diff)
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.c15
-rw-r--r--net/dccp/ipv6.c15
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;