[Qemu-devel] [PULL 3/3] Fix total IP header length in forwarded TCP packets

[Samuel Thibault]

From: Sjors Gielen <address@hidden>

When forwarding TCP packets, the internal tcpiphdr struct length was wrongly
used inside the IP header. This commit changes the behaviour to what is used
by tcp_output.c, using the correct full IP header + payload length.

Signed-off-by: Sjors Gielen <address@hidden>
Signed-off-by: Samuel Thibault <address@hidden>
---
 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;
-- 
2.11.0