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ipv6: syncookies: do not skip ->iif initialization

PATCH Applied Florian Westphal 2 participants 2 messages Jun 13, 2010 – Jun 16, 2010

Subsystems (3)
Networking Network drivers TCP
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Florian Westphal

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#0 lore raw

PATCH 1/1 ipv6: syncookies: do not skip ->iif initialization

When syncookies are in effect, req->iif is left uninitialized. In case of e.g. link-local addresses the route lookup then fails and no syn-ack is sent.

Rearrange things so ->iif is also initialized in the syncookie case.

want_cookie can only be true when the isn was zero, thus move the want_cookie check into the "!isn" branch.

Cc Glenn Griffin <[email protected]>
Signed-off-by Florian Westphal <[email protected]>
---
 net/ipv6/tcp_ipv6.c |   13 +++++++------
 1 files changed, 7 insertions(+), 6 deletions(-)
net/ipv6/tcp_ipv6.c +7 -6
index 5887141..f875345 100644
@@ -1272,10 +1272,7 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 	if (!want_cookie)
 		TCP_ECN_create_request(req, tcp_hdr(skb));
 
-	if (want_cookie) {
-		isn = cookie_v6_init_sequence(sk, skb, &req->mss);
-		req->cookie_ts = tmp_opt.tstamp_ok;
-	} else if (!isn) {
+	if (!isn) {
 		if (ipv6_opt_accepted(sk, skb) ||
 		    np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
 		    np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {

@@ -1288,8 +1285,12 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 		if (!sk->sk_bound_dev_if &&
 		    ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL)
 			treq->iif = inet6_iif(skb);
-
-		isn = tcp_v6_init_sequence(skb);
+		if (!want_cookie) {
+			isn = tcp_v6_init_sequence(skb);
+		} else {
+			isn = cookie_v6_init_sequence(sk, skb, &req->mss);
+			req->cookie_ts = tmp_opt.tstamp_ok;
+		}
 	}
 	tcp_rsk(req)->snt_isn = isn;
Signature · 1 line
1.6.4.4
maintainer Applied
#1 lore raw

From: Florian Westphal <[email protected]>
Date: Sun, 13 Jun 2010 23:29:39 +0200

Quoted 11 lines

When syncookies are in effect, req->iif is left uninitialized. In case of e.g. link-local addresses the route lookup then fails and no syn-ack is sent.

Rearrange things so ->iif is also initialized in the syncookie case.

want_cookie can only be true when the isn was zero, thus move the want_cookie check into the "!isn" branch.

Cc Glenn Griffin <[email protected]>
Signed-off-by Florian Westphal <[email protected]>

Applied, thanks.