do not use gcc-ism for macro, instead abuse C-syntax

[tcpdump] / print-tcp.c

diff --git a/print-tcp.c b/print-tcp.c
index 6cce9e21e746779067dd925d119e82c3ed64af42..86195a856086405f0ae1c78da8f3f3f7c76e41e7 100644 (file)
--- a/print-tcp.c
+++ b/print-tcp.c
@@ -21,7 +21,7 @@
 
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-tcp.c,v 1.111 2004-03-23 07:15:36 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/tcpdump/print-tcp.c,v 1.112 2004-04-05 00:12:54 mcr Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -53,7 +53,7 @@ static const char rcsid[] _U_ =
 #ifdef HAVE_LIBCRYPTO
 #include <openssl/md5.h>
 
-static int tcp_verify_signature(const struct ip *ip, struct tcphdr *tp,
+static int tcp_verify_signature(const struct ip *ip, const struct tcphdr *tp,
     const u_char *data, int length, const u_char *rcvsig);
 #endif
 
@@ -703,14 +703,17 @@ print_tcp_rst_data(register const u_char *sp, u_int length)
 
 #ifdef HAVE_LIBCRYPTO
 static int
-tcp_verify_signature(const struct ip *ip, struct tcphdr *tp,
+tcp_verify_signature(const struct ip *ip, const struct tcphdr *tp,
     const u_char *data, int length, const u_char *rcvsig)
 {
+        struct tcphdr tp1;
        char sig[TCP_SIGLEN];
        char zero_proto = 0;
        MD5_CTX ctx;
        u_short savecsum, tlen;
 
+       tp1 = *tp;
+
        if (tcpmd5secret == NULL)
                return (-1);
 
@@ -725,14 +728,15 @@ tcp_verify_signature(const struct ip *ip, struct tcphdr *tp,
        tlen = EXTRACT_16BITS(&ip->ip_len) - IP_HL(ip) * 4;
        tlen = htons(tlen);
        MD5_Update(&ctx, (char *)&tlen, sizeof(tlen));
+
        /*
         * Step 2: Update MD5 hash with TCP header, excluding options.
         * The TCP checksum must be set to zero.
         */
-       savecsum = tp->th_sum;
-       tp->th_sum = 0;
-       MD5_Update(&ctx, (char *)tp, sizeof(struct tcphdr));
-       tp->th_sum = savecsum;
+       savecsum = tp1.th_sum;
+       tp1.th_sum = 0;
+       MD5_Update(&ctx, (char *)&tp1, sizeof(struct tcphdr));
+       tp1.th_sum = savecsum;
        /*
         * Step 3: Update MD5 hash with TCP segment data, if present.
         */