Fix total IP header length in forwarded TCP packets

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 <sjors@sjorsgielen.nl>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/tcp_subr.c b/tcp_subr.c
index 5fc6aa4..59f61fc 100644
--- a/tcp_subr.c
+++ b/tcp_subr.c
@@ -207,7 +207,7 @@ void 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;
@@ -227,7 +227,7 @@ void 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;