Calculate UDP/TCP pseudo-checksum properly in the presence of

[tcpdump] / print-tcp.c

diff --git a/print-tcp.c b/print-tcp.c
index 1f57dfcf46e7388d53b083d0241d4c0f50d39f00..0d924dea87c1a15e6dc6ef5a73ae4d6a721ea2de 100644 (file)
--- a/print-tcp.c
+++ b/print-tcp.c
@@ -21,7 +21,7 @@
 
 #ifndef lint
 static const char rcsid[] =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-tcp.c,v 1.96 2002-07-21 20:56:24 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/tcpdump/print-tcp.c,v 1.97 2002-07-28 04:14:22 fenner Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -122,7 +122,10 @@ static int tcp_cksum(register const struct ip *ip,
        phu.ph.mbz = 0;
        phu.ph.proto = IPPROTO_TCP;
        memcpy(&phu.ph.src, &ip->ip_src.s_addr, sizeof(u_int32_t));
-       memcpy(&phu.ph.dst, &ip->ip_dst.s_addr, sizeof(u_int32_t));
+       if (IP_HL(ip) == 5)
+               memcpy(&phu.ph.dst, &ip->ip_dst.s_addr, sizeof(u_int32_t));
+       else
+               phu.ph.dst = ip_finddst(ip);
 
        sp = &phu.pa[0];
        return in_cksum((u_short *)tp, len,