X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/4da3308f277b7cb520a0edf43b2cca2bc0ed2e29..HEAD:/print-ip6.c

diff --git a/print-ip6.c b/print-ip6.c
index 285fc979..269b41fb 100644
--- a/print-ip6.c
+++ b/print-ip6.c
@@ -21,9 +21,7 @@
 
 /* \summary: IPv6 printer */
 
-#ifdef HAVE_CONFIG_H
 #include <config.h>
-#endif
 
 #include "netdissect-stdinc.h"
 
@@ -246,16 +244,8 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
 		ND_PRINT(" ");
 	}
 
-	if (IP6_VERSION(ip6) != 6) {
-		ND_PRINT("version error: %u != 6", IP6_VERSION(ip6));
-		return;
-	}
-
-	ND_TCHECK_SIZE(ip6);
-	if (length < sizeof (struct ip6_hdr)) {
-		ND_PRINT("truncated-ip6 %u", length);
-		return;
-	}
+	ND_ICHECK_ZU(length, <, sizeof (struct ip6_hdr));
+	ND_ICHECKMSG_U("version", IP6_VERSION(ip6), !=, 6);
 
 	payload_len = GET_BE_U_2(ip6->ip6_plen);
 	/*
@@ -282,9 +272,12 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
 	 */
 	if (payload_len != 0) {
 		len = payload_len + sizeof(struct ip6_hdr);
-		if (length < len)
-			ND_PRINT("truncated-ip6 - %u bytes missing!",
-				len - length);
+		if (len > length) {
+			ND_PRINT("[header+payload length %u > length %u]",
+				 len, length);
+			nd_print_invalid(ndo);
+			ND_PRINT(" ");
+		}
 	} else
 		len = length + sizeof(struct ip6_hdr);
 
@@ -299,17 +292,20 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
 	    if (flow & 0x000fffff)
 	        ND_PRINT("flowlabel 0x%05x, ", flow & 0x000fffff);
 
-	    ND_PRINT("hlim %u, next-header %s (%u) payload length: %u) ",
+	    ND_PRINT("hlim %u, next-header %s (%u), payload length %u) ",
 	                 GET_U_1(ip6->ip6_hlim),
 	                 tok2str(ipproto_values,"unknown",nh),
 	                 nh,
 	                 payload_len);
 	}
+	ND_TCHECK_SIZE(ip6);
 
 	/*
-	 * Cut off the snapshot length to the end of the IP payload.
+	 * Cut off the snapshot length to the end of the IP payload
+	 * or the end of the data in which it's contained, whichever
+	 * comes first.
 	 */
-	if (!nd_push_snaplen(ndo, bp, len)) {
+	if (!nd_push_snaplen(ndo, bp, ND_MIN(length, len))) {
 		(*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC,
 			"%s: can't push snaplen on buffer stack", __func__);
 	}
@@ -332,7 +328,7 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
 		    nh != IPPROTO_TCP && nh != IPPROTO_UDP &&
 		    nh != IPPROTO_DCCP && nh != IPPROTO_SCTP) {
 			ND_PRINT("%s > %s: ", GET_IP6ADDR_STRING(ip6->ip6_src),
-				     GET_IP6ADDR_STRING(ip6->ip6_dst));
+				 GET_IP6ADDR_STRING(ip6->ip6_dst));
 		}
 
 		switch (nh) {
@@ -391,7 +387,7 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
 		case IPPROTO_MOBILITY_OLD:
 		case IPPROTO_MOBILITY:
 			/*
-			 * XXX - we don't use "advance"; RFC 3775 says that
+			 * RFC 3775 says that
 			 * the next header field in a mobility header
 			 * should be IPPROTO_NONE, but speaks of
 			 * the possibility of a future extension in
@@ -438,9 +434,12 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
 				len = payload_len + sizeof(struct ip6_hdr);
 				if (len < total_advance)
 					goto trunc;
-				if (length < len)
-					ND_PRINT("truncated-ip6 - %u bytes missing!",
-						len - length);
+				if (len > length) {
+					ND_PRINT("[header+payload length %u > length %u]",
+						 len, length);
+					nd_print_invalid(ndo);
+					ND_PRINT(" ");
+				}
 				nd_change_snaplen(ndo, bp, len);
 
 				/*
@@ -501,4 +500,8 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
 	return;
 trunc:
 	nd_print_trunc(ndo);
+	return;
+
+invalid:
+	nd_print_invalid(ndo);
 }