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authorDmitry Butskoy <dmitry@butskoy.name>2007-07-18 02:51:17 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2007-08-09 14:27:28 -0700
commitc709631f917050fd9633c7dde8ef7d7d31f1ecd9 (patch)
treeeca55986b262ff78134cccbbf8753f14a781101f
parent8a1c1646795c03edc0c4f18d3ad97e18e56f888c (diff)
downloadlwn-c709631f917050fd9633c7dde8ef7d7d31f1ecd9.tar.gz
lwn-c709631f917050fd9633c7dde8ef7d7d31f1ecd9.zip
Fix error queue socket lookup in ipv6
[IPV6]: MSG_ERRQUEUE messages do not pass to connected raw sockets From: Dmitry Butskoy <dmitry@butskoy.name> Taken from http://bugzilla.kernel.org/show_bug.cgi?id=8747 Problem Description: It is related to the possibility to obtain MSG_ERRQUEUE messages from the udp and raw sockets, both connected and unconnected. There is a little typo in net/ipv6/icmp.c code, which prevents such messages to be delivered to the errqueue of the correspond raw socket, when the socket is CONNECTED. The typo is due to swap of local/remote addresses. Consider __raw_v6_lookup() function from net/ipv6/raw.c. When a raw socket is looked up usual way, it is something like: sk = __raw_v6_lookup(sk, nexthdr, daddr, saddr, IP6CB(skb)->iif); where "daddr" is a destination address of the incoming packet (IOW our local address), "saddr" is a source address of the incoming packet (the remote end). But when the raw socket is looked up for some icmp error report, in net/ipv6/icmp.c:icmpv6_notify() , daddr/saddr are obtained from the echoed fragment of the "bad" packet, i.e. "daddr" is the original destination address of that packet, "saddr" is our local address. Hence, for icmpv6_notify() must use "saddr, daddr" in its arguments, not "daddr, saddr" ... Steps to reproduce: Create some raw socket, connect it to an address, and cause some error situation: f.e. set ttl=1 where the remote address is more than 1 hop to reach. Set IPV6_RECVERR . Then send something and wait for the error (f.e. poll() with POLLERR|POLLIN). You should receive "time exceeded" icmp message (because of "ttl=1"), but the socket do not receive it. If you do not connect your raw socket, you will receive MSG_ERRQUEUE successfully. (The reason is that for unconnected socket there are no actual checks for local/remote addresses). Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--net/ipv6/icmp.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index e9bcce9e7bdf..c956037c8066 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -604,7 +604,7 @@ static void icmpv6_notify(struct sk_buff *skb, int type, int code, __be32 info)
read_lock(&raw_v6_lock);
if ((sk = sk_head(&raw_v6_htable[hash])) != NULL) {
- while((sk = __raw_v6_lookup(sk, nexthdr, daddr, saddr,
+ while ((sk = __raw_v6_lookup(sk, nexthdr, saddr, daddr,
IP6CB(skb)->iif))) {
rawv6_err(sk, skb, NULL, type, code, inner_offset, info);
sk = sk_next(sk);