X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/6bb25b4b4c84e5015bdcfcbd688dff512a20d971..5ef0bcb5edd748de9d9af13c40da0395dfdd94e8:/print-domain.c

diff --git a/print-domain.c b/print-domain.c
index 2950c73c..ad08073f 100644
--- a/print-domain.c
+++ b/print-domain.c
@@ -116,25 +116,19 @@ blabel_print(netdissect_options *ndo,
 	/* print the bit string as a hex string */
 	ND_PRINT("\\[x");
 	for (bitp = cp + 1, b = bitlen; bitp < lim && b > 7; b -= 8, bitp++) {
-		ND_TCHECK_1(bitp);
 		ND_PRINT("%02x", GET_U_1(bitp));
 	}
 	if (b > 4) {
-		ND_TCHECK_1(bitp);
 		tc = GET_U_1(bitp);
 		bitp++;
 		ND_PRINT("%02x", tc & (0xff << (8 - b)));
 	} else if (b > 0) {
-		ND_TCHECK_1(bitp);
 		tc = GET_U_1(bitp);
 		bitp++;
 		ND_PRINT("%1x", ((tc >> 4) & 0x0f) & (0x0f << (4 - b)));
 	}
 	ND_PRINT("/%u]", bitlen);
 	return lim;
-trunc:
-	ND_PRINT(".../%u]", bitlen);
-	return NULL;
 }
 
 static int
@@ -428,7 +422,6 @@ eopt_print(netdissect_options *ndo,
     return (cp + data_len);
 
   trunc:
-    nd_print_invalid(ndo);
     return (NULL);
 
 }
@@ -843,7 +836,7 @@ ns_rprint(netdissect_options *ndo,
 
 void
 domain_print(netdissect_options *ndo,
-         const u_char *bp, u_int length, int is_mdns)
+             const u_char *bp, u_int length, int over_tcp, int is_mdns)
 {
 	const dns_header_t *np;
 	uint16_t flags, rcode, rdlen, type;
@@ -853,6 +846,34 @@ domain_print(netdissect_options *ndo,
 	uint16_t b2;
 
 	ndo->ndo_protocol = "domain";
+
+	if (over_tcp) {
+		/*
+		 * The message is prefixed with a two byte length field
+		 * which gives the message length, excluding the two byte
+		 * length field. (RFC 1035 - 4.2.2. TCP usage)
+		 */
+		if (length < 2) {
+			ND_PRINT(" [DNS over TCP: length %u < 2]", length);
+			nd_print_invalid(ndo);
+			return;
+		} else {
+			length -= 2; /* excluding the two byte length field */
+			if (GET_BE_U_2(bp) != length) {
+				ND_PRINT(" [prefix length(%u) != length(%u)]",
+					 GET_BE_U_2(bp), length);
+				nd_print_invalid(ndo);
+				return;
+			} else {
+				bp += 2;
+				/* in over TCP case, we need to prepend a space
+				 * (not needed in over UDP case)
+				 */
+				ND_PRINT(" ");
+			}
+		}
+	}
+
 	np = (const dns_header_t *)bp;
 
 	if(length < sizeof(*np)) {
@@ -901,7 +922,7 @@ domain_print(netdissect_options *ndo,
 		if (cp + 1 > ndo->ndo_snapend)
 			goto print;
 		if (type == T_OPT) {
-			rcode |= (*cp << 4);
+			rcode |= (GET_U_1(cp) << 4);
 			goto print;
 		}
 		cp += 4;