From owner-freebsd-hackers  Wed Jan 19  5:56:21 2000
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To: hackers@freebsd.org, security@freebsd.org
Subject: New option to ping(8): dump packet contents
From: Dag-Erling Smorgrav <des@flood.ping.uio.no>
Date: 19 Jan 2000 14:56:10 +0100
Message-ID: <xzpd7qymah1.fsf@flood.ping.uio.no>
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--=-=-=

The attached patch adds a -D option to ping(8) which makes it dump the
payload of the reply packet instead of comparing it to the payload of
the original request packet. This is useful in cases where the target
host purposeldy modifies the payload before replying, e.g. if you hack
your stack to report the load average in echo reply packets.

DES
-- 
Dag-Erling Smorgrav - des@flood.ping.uio.no


--=-=-=
Content-Disposition: attachment; filename=ping-dump.diff
Content-Description: patch

Index: ping.c
===================================================================
RCS file: /home/ncvs/src/sbin/ping/ping.c,v
retrieving revision 1.49
diff -u -r1.49 ping.c
--- ping.c	2000/01/14 23:40:38	1.49
+++ ping.c	2000/01/19 13:48:53
@@ -133,6 +133,7 @@
 #define F_POLICY	0x4000
 #endif /*IPSEC_POLICY_IPSEC*/
 #endif /*IPSEC*/
+#define F_DUMP		0x8000
 
 /*
  * MAX_DUP_CHK is the number of bits in received table, i.e. the maximum
@@ -234,10 +235,10 @@
 
 	datap = &outpack[8 + PHDR_LEN];
 #ifndef IPSEC
-	while ((ch = getopt(argc, argv, "I:LQRT:c:adfi:l:np:qrs:t:v")) != -1)
+	while ((ch = getopt(argc, argv, "I:LQRT:c:adDfi:l:np:qrs:t:v")) != -1)
 #else
 #ifdef IPSEC_POLICY_IPSEC
-	while ((ch = getopt(argc, argv, "I:LQRT:c:adfi:l:np:qrs:t:vP:")) != -1)
+	while ((ch = getopt(argc, argv, "I:LQRT:c:adDfi:l:np:qrs:t:vP:")) != -1)
 #endif /*IPSEC_POLICY_IPSEC*/
 #endif
 	{
@@ -256,6 +257,9 @@
 		case 'd':
 			options |= F_SO_DEBUG;
 			break;
+		case 'D':
+			options |= F_DUMP;
+			break;
 		case 'f':
 			if (uid) {
 				errno = EPERM;
@@ -837,7 +841,13 @@
 			cp = (u_char*)&icp->icmp_data[PHDR_LEN];
 			dp = &outpack[8 + PHDR_LEN];
 			for (i = PHDR_LEN; i < datalen; ++i, ++cp, ++dp) {
-				if (*cp != *dp) {
+				if (options & F_DUMP) {
+					if ((i - PHDR_LEN) % 16 == 8)
+						putchar(' ');
+					if ((i - PHDR_LEN) % 16 == 0)
+						putchar('\n');
+					printf(" %02x", *dp);
+				} else if (*cp != *dp) {
 	(void)printf("\nwrong data byte #%d should be 0x%x but was 0x%x",
 	    i, *dp, *cp);
 					printf("\ncp:");

--=-=-=--


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