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author | Dmitry Butskoy <dmitry@butskoy.name> | 2007-07-15 06:53:08 (GMT) |
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committer | David S. Miller <davem@davemloft.net> | 2007-07-15 06:53:08 (GMT) |
commit | f13ec93fba60d339dc1663eb47b2fb801225d2d2 (patch) | |
tree | 1f6f12311f307d46b33a2a2afae43853f28fb5ad /net/ipv6/icmp.c | |
parent | d09f51b6997f3f443c5741bc696651e479576715 (diff) | |
download | linux-fsl-qoriq-f13ec93fba60d339dc1663eb47b2fb801225d2d2.tar.xz |
[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>
Diffstat (limited to 'net/ipv6/icmp.c')
-rw-r--r-- | net/ipv6/icmp.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index 4765a29..6a6714d 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); |