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From: Tao Wu <ytht.net@gmail.com>
To: qemu-devel@nongnu.org
Cc: Tao Wu <lepton@google.com>
Subject: [Qemu-devel] [PATCH] Fix wrong length in IP header in tcp_respond.
Date: Thu, 20 Apr 2017 13:27:45 -0700	[thread overview]
Message-ID: <20170420202745.149601-1-lepton@google.com> (raw)

This bug was introduced by https://github.com/qemu/qemu/commit/98c6305
And then we 'fix' it in
https://github.com/qemu/qemu/commit/27d92e
Actually I believe the root cause was that we sent out a RST packet with
wrong length and then get ignored by OS.

Signed-off-by: Tao Wu <lepton@google.com>
---
 slirp/tcp_subr.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/slirp/tcp_subr.c b/slirp/tcp_subr.c
index ed16e1807f..dc8b4bbb50 100644
--- a/slirp/tcp_subr.c
+++ b/slirp/tcp_subr.c
@@ -204,7 +204,7 @@ tcp_respond(struct tcpcb *tp, struct tcpiphdr *ti, struct mbuf *m,
 	    m->m_len  -= sizeof(struct tcpiphdr) - sizeof(struct tcphdr)
 	                                         - sizeof(struct ip);
 	    ip = mtod(m, struct ip *);
-	    ip->ip_len = tlen;
+	    ip->ip_len = m->m_len;
 	    ip->ip_dst = tcpiph_save.ti_dst;
 	    ip->ip_src = tcpiph_save.ti_src;
 	    ip->ip_p = tcpiph_save.ti_pr;
@@ -224,7 +224,7 @@ tcp_respond(struct tcpcb *tp, struct tcpiphdr *ti, struct mbuf *m,
 	    m->m_len  -= sizeof(struct tcpiphdr) - sizeof(struct tcphdr)
 	                                         - sizeof(struct ip6);
 	    ip6 = mtod(m, struct ip6 *);
-	    ip6->ip_pl = tlen;
+	    ip6->ip_pl = tcpiph_save.ti_len;
 	    ip6->ip_dst = tcpiph_save.ti_dst6;
 	    ip6->ip_src = tcpiph_save.ti_src6;
 	    ip6->ip_nh = tcpiph_save.ti_nh6;
-- 
2.12.2.816.g2cccc81164-goog

             reply	other threads:[~2017-04-20 20:27 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-20 20:27 Tao Wu [this message]
2017-04-21  2:25 ` [Qemu-devel] [PATCH] Fix wrong length in IP header in tcp_respond no-reply

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