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udp: fix for unicast RX path optimization

PATCH In review Jorge Boncompte [DTI2] 3 participants 4 messages Apr 8, 2010

Subsystems (3)
Networking Network drivers UDP
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Jorge Boncompte [DTI2]

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#0 lore raw

PATCH 1/1 udp: fix for unicast RX path optimization

	Commits 5051ebd275de672b807c28d93002c2fb0514a3c9 and

5051ebd275de672b807c28d93002c2fb0514a3c9 ("ipv[46]: udp: optimize unicast RX path") broke some programs.

After upgrading a L2TP server to 2.6.33 it started to fail, tunnels going up an
down, after the 10th tunnel came up. My modified rp-l2tp uses a global unconnected socket bound to (INADDR_ANY, 1701) and one connected socket per tunnel after parameter negotiation.

After ten sockets were open and due to mixed parameters to
udp[46]_lib_lookup2() kernel started to drop packets.

Signed-off-by Jorge Boncompte [DTI2] <[email protected]>

---

net/ipv4/udp.c +2 -2
diff -uNrp linux-2.6.33/net/ipv4/udp.c kernel-netns/net/ipv4/udp.c
@@ -471,8 +471,8 @@ static struct sock *__udp4_lib_lookup(st
 			if (hslot->count < hslot2->count)
 				goto begin;
 
-			result = udp4_lib_lookup2(net, INADDR_ANY, sport,
-						  daddr, hnum, dif,
+			result = udp4_lib_lookup2(net, saddr, sport,
+						  INADDR_ANY, hnum, dif,
 						  hslot2, slot2);
 		}
 		rcu_read_unlock();
net/ipv6/udp.c +2 -2
diff -uNrp linux-2.6.33/net/ipv6/udp.c kernel-netns/net/ipv6/udp.c
@@ -258,8 +258,8 @@ static struct sock *__udp6_lib_lookup(st
 			if (hslot->count < hslot2->count)
 				goto begin;
 
-			result = udp6_lib_lookup2(net, &in6addr_any, sport,
-						  daddr, hnum, dif,
+			result = udp6_lib_lookup2(net, saddr, sport,
+						  &in6addr_any, hnum, dif,
 						  hslot2, slot2);
 		}
 		rcu_read_unlock();
#1 lore raw
Quoted 9 lines · Le jeudi 08 avril 2010 à 16:56 +0200, Jorge Boncompte [DTI2] a écrit :
	Commits 5051ebd275de672b807c28d93002c2fb0514a3c9 and

5051ebd275de672b807c28d93002c2fb0514a3c9 ("ipv[46]: udp: optimize unicast RX path") broke some programs.

After upgrading a L2TP server to 2.6.33 it started to fail, tunnels going up an
down, after the 10th tunnel came up. My modified rp-l2tp uses a global unconnected socket bound to (INADDR_ANY, 1701) and one connected socket per tunnel after parameter negotiation.

Quoted 4 lines

After ten sockets were open and due to mixed parameters to
udp[46]_lib_lookup2() kernel started to drop packets.

Signed-off-by Jorge Boncompte [DTI2] <[email protected]>

Oops...

Thank you for finding this bug, this is indeed the right fix.

This is a stable candidate. David, can you catch it even if Jorge didnt sent you a copy ?

Signed-off-by Eric Dumazet <[email protected]>
maintainer
#2 lore raw

From: Eric Dumazet <[email protected]>
Date: Thu, 08 Apr 2010 17:12:27 +0200

Quoted 2 lines

This is a stable candidate. David, can you catch it even if Jorge didnt sent you a copy ?

It went to netdev and thus patchwork and I both have it :-)

maintainer
#3 lore raw
In reply to Eric Dumazet

From: Eric Dumazet <[email protected]>
Date: Thu, 08 Apr 2010 17:12:27 +0200

Quoted 14 lines · Le jeudi 08 avril 2010 à 16:56 +0200, Jorge Boncompte [DTI2] a écrit :
Quoted 13 lines
	Commits 5051ebd275de672b807c28d93002c2fb0514a3c9 and

5051ebd275de672b807c28d93002c2fb0514a3c9 ("ipv[46]: udp: optimize unicast RX path") broke some programs.

After upgrading a L2TP server to 2.6.33 it started to fail, tunnels going up an
down, after the 10th tunnel came up. My modified rp-l2tp uses a global unconnected socket bound to (INADDR_ANY, 1701) and one connected socket per tunnel after parameter negotiation.

After ten sockets were open and due to mixed parameters to
udp[46]_lib_lookup2() kernel started to drop packets.

Signed-off-by Jorge Boncompte [DTI2] <[email protected]>

...

Quoted 1 line
Signed-off-by Eric Dumazet <[email protected]>

Applied and queued up for -stable.