From: Guy Harris <guy@alum.mit.edu>
Date: Wed, 12 Nov 2014 09:09:27 +0000 (-0800)
Subject: Report a too-long unreachable destination list.
X-Git-Url: https://git.tcpdump.org/tcpdump/commitdiff_plain/c33ee7ff380c77ec2c0dbd8fceeb16cc41c618d0

Report a too-long unreachable destination list.

Running out of packet length before running out of unreachable
destinations is an error; report it as such.

Don't worry about leftover data past the end of the list of unreachable
destinations.
---

diff --git a/print-aodv.c b/print-aodv.c
index 9b3523a5..ef27eee6 100644
--- a/print-aodv.c
+++ b/print-aodv.c
@@ -277,14 +277,15 @@ aodv_rerr(netdissect_options *ndo, const u_char *dat, u_int length)
 	    ap->rerr_dc, length));
 	dp = (struct rerr_unreach *)(dat + sizeof(*ap));
 	i = length - sizeof(*ap);
-	for (dc = ap->rerr_dc; dc != 0 && i >= sizeof(*dp);
-	    ++dp, --dc, i -= sizeof(*dp)) {
+	for (dc = ap->rerr_dc; dc != 0; dc--) {
 		ND_TCHECK(*dp);
+		if (i < sizeof(*dp))
+			goto trunc;
 		ND_PRINT((ndo, " {%s}(%ld)", ipaddr_string(ndo, &dp->u_da),
 		    (unsigned long)EXTRACT_32BITS(&dp->u_ds)));
+		dp++;
+		i -= sizeof(*dp);
 	}
-	if ((i % sizeof(*dp)) != 0)
-		goto trunc;
 	return;
 
 trunc:
@@ -386,14 +387,15 @@ aodv_v6_rerr(netdissect_options *ndo, const u_char *dat _U_, u_int length)
 	    ap->rerr_dc, length));
 	dp6 = (struct rerr_unreach6 *)(void *)(ap + 1);
 	i = length - sizeof(*ap);
-	for (dc = ap->rerr_dc; dc != 0 && i >= sizeof(*dp6);
-	    ++dp6, --dc, i -= sizeof(*dp6)) {
+	for (dc = ap->rerr_dc; dc != 0; dc--) {
 		ND_TCHECK(*dp6);
+		if (i < sizeof(*dp6))
+			goto trunc;
 		ND_PRINT((ndo, " {%s}(%ld)", ip6addr_string(ndo, &dp6->u_da),
 		    (unsigned long)EXTRACT_32BITS(&dp6->u_ds)));
+		dp6++;
+		i -= sizeof(*dp6);
 	}
-	if ((i % sizeof(*dp6)) != 0)
-		goto trunc;
 	return;
 
 trunc:
@@ -498,14 +500,15 @@ aodv_v6_draft_01_rerr(netdissect_options *ndo, const u_char *dat _U_, u_int leng
 	    ap->rerr_dc, length));
 	dp6 = (struct rerr_unreach6_draft_01 *)(void *)(ap + 1);
 	i = length - sizeof(*ap);
-	for (dc = ap->rerr_dc; dc != 0 && i >= sizeof(*dp6);
-	    ++dp6, --dc, i -= sizeof(*dp6)) {
+	for (dc = ap->rerr_dc; dc != 0; dc--) {
 		ND_TCHECK(*dp6);
+		if (i < sizeof(*dp6))
+			goto trunc;
 		ND_PRINT((ndo, " {%s}(%ld)", ip6addr_string(ndo, &dp6->u_da),
 		    (unsigned long)EXTRACT_32BITS(&dp6->u_ds)));
+		dp6++;
+		i -= sizeof(*dp6);
 	}
-	if ((i % sizeof(*dp6)) != 0)
-		goto trunc;
 	return;
 
 trunc: