X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/7d95dbd02fdcadf8b56a61caab63626180d760ba..5ef0bcb5edd748de9d9af13c40da0395dfdd94e8:/print-domain.c

diff --git a/print-domain.c b/print-domain.c
index cec085be..ad08073f 100644
--- a/print-domain.c
+++ b/print-domain.c
@@ -52,7 +52,7 @@ static const char *ns_resp[] = {
 };
 
 static const char *
-ns_rcode(int rcode) {
+ns_rcode(u_int rcode) {
 	static char buf[sizeof(" Resp4095")];
 
 	if (rcode < sizeof(ns_resp)/sizeof(ns_resp[0])) {
@@ -71,7 +71,7 @@ ns_nskip(netdissect_options *ndo,
 
 	if (!ND_TTEST_1(cp))
 		return (NULL);
-	i = EXTRACT_U_1(cp);
+	i = GET_U_1(cp);
 	cp++;
 	while (i) {
 		if ((i & INDIR_MASK) == INDIR_MASK)
@@ -83,7 +83,7 @@ ns_nskip(netdissect_options *ndo,
 				return(NULL); /* unknown ELT */
 			if (!ND_TTEST_1(cp))
 				return (NULL);
-			if ((bitlen = EXTRACT_U_1(cp)) == 0)
+			if ((bitlen = GET_U_1(cp)) == 0)
 				bitlen = 256;
 			cp++;
 			bytelen = (bitlen + 7) / 8;
@@ -92,13 +92,12 @@ ns_nskip(netdissect_options *ndo,
 			cp += i;
 		if (!ND_TTEST_1(cp))
 			return (NULL);
-		i = EXTRACT_U_1(cp);
+		i = GET_U_1(cp);
 		cp++;
 	}
 	return (cp);
 }
 
-/* print a <domain-name> */
 static const u_char *
 blabel_print(netdissect_options *ndo,
              const u_char *cp)
@@ -109,7 +108,7 @@ blabel_print(netdissect_options *ndo,
 
 	if (!ND_TTEST_1(cp))
 		return(NULL);
-	if ((bitlen = EXTRACT_U_1(cp)) == 0)
+	if ((bitlen = GET_U_1(cp)) == 0)
 		bitlen = 256;
 	slen = (bitlen + 3) / 4;
 	lim = cp + 1 + slen;
@@ -117,25 +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", EXTRACT_U_1(bitp));
+		ND_PRINT("%02x", GET_U_1(bitp));
 	}
 	if (b > 4) {
-		ND_TCHECK_1(bitp);
-		tc = EXTRACT_U_1(bitp);
+		tc = GET_U_1(bitp);
 		bitp++;
 		ND_PRINT("%02x", tc & (0xff << (8 - b)));
 	} else if (b > 0) {
-		ND_TCHECK_1(bitp);
-		tc = EXTRACT_U_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
@@ -146,7 +139,7 @@ labellen(netdissect_options *ndo,
 
 	if (!ND_TTEST_1(cp))
 		return(-1);
-	i = EXTRACT_U_1(cp);
+	i = GET_U_1(cp);
 	if ((i & INDIR_MASK) == EDNS0_MASK) {
 		u_int bitlen, elt;
 		if ((elt = (i & ~INDIR_MASK)) != EDNS0_ELT_BITLABEL) {
@@ -155,15 +148,16 @@ labellen(netdissect_options *ndo,
 		}
 		if (!ND_TTEST_1(cp + 1))
 			return(-1);
-		if ((bitlen = EXTRACT_U_1(cp + 1)) == 0)
+		if ((bitlen = GET_U_1(cp + 1)) == 0)
 			bitlen = 256;
 		return(((bitlen + 7) / 8) + 1);
 	} else
 		return(i);
 }
 
+/* print a <domain-name> */
 const u_char *
-ns_nprint(netdissect_options *ndo,
+fqdn_print(netdissect_options *ndo,
           const u_char *cp, const u_char *bp)
 {
 	u_int i, l;
@@ -177,7 +171,7 @@ ns_nprint(netdissect_options *ndo,
 	if (!ND_TTEST_1(cp))
 		return(NULL);
 	max_offset = (u_int)(cp - bp);
-	i = EXTRACT_U_1(cp);
+	i = GET_U_1(cp);
 	cp++;
 	if ((i & INDIR_MASK) != INDIR_MASK) {
 		compress = 0;
@@ -193,7 +187,7 @@ ns_nprint(netdissect_options *ndo,
 				}
 				if (!ND_TTEST_1(cp))
 					return(NULL);
-				offset = (((i << 8) | EXTRACT_U_1(cp)) & 0x3fff);
+				offset = (((i << 8) | GET_U_1(cp)) & 0x3fff);
 				/*
 				 * This must move backwards in the packet.
 				 * No RFC explicitly says that, but BIND's
@@ -214,7 +208,7 @@ ns_nprint(netdissect_options *ndo,
 					return(NULL);
 				if (!ND_TTEST_1(cp))
 					return(NULL);
-				i = EXTRACT_U_1(cp);
+				i = GET_U_1(cp);
 				cp++;
 				continue;
 			}
@@ -241,7 +235,7 @@ ns_nprint(netdissect_options *ndo,
 				return(NULL);
 			if (!ND_TTEST_1(cp))
 				return(NULL);
-			i = EXTRACT_U_1(cp);
+			i = GET_U_1(cp);
 			cp++;
 			if (!compress)
 				rp += l + 1;
@@ -260,16 +254,183 @@ ns_cprint(netdissect_options *ndo,
 
 	if (!ND_TTEST_1(cp))
 		return (NULL);
-	i = EXTRACT_U_1(cp);
+	i = GET_U_1(cp);
 	cp++;
 	if (nd_printn(ndo, cp, i, ndo->ndo_snapend))
 		return (NULL);
 	return (cp + i);
 }
 
+static void
+print_eopt_ecs(netdissect_options *ndo, const u_char *cp,
+               u_int data_len)
+{
+    u_int family, addr_bits, src_len, scope_len;
+
+    u_char padded[32];
+    char addr[INET6_ADDRSTRLEN];
+
+    /* ecs option must at least contain family, src len, and scope len */
+    if (data_len < 4) {
+        nd_print_invalid(ndo);
+        return;
+    }
+
+    family = GET_BE_U_2(cp);
+    cp += 2;
+    src_len = GET_U_1(cp);
+    cp += 1;
+    scope_len = GET_U_1(cp);
+    cp += 1;
+
+    if (family == 1)
+        addr_bits = 32;
+    else if (family == 2)
+        addr_bits = 128;
+    else {
+        nd_print_invalid(ndo);
+        return;
+    }
+
+    if (data_len - 4 > (addr_bits / 8)) {
+        nd_print_invalid(ndo);
+        return;
+    }
+    /* checks for invalid ecs scope or source length */
+    if (src_len > addr_bits || scope_len > addr_bits || ((src_len + 7) / 8) != (data_len - 4)) {
+        nd_print_invalid(ndo);
+        return;
+    }
+
+    /* pad the truncated address from ecs with zeros */
+    memset(padded, 0, sizeof(padded));
+    memcpy(padded, cp, data_len - 4);
+
+
+    if (family == 1)
+        ND_PRINT("%s/%d/%d", addrtostr(padded, addr, INET_ADDRSTRLEN),
+                src_len, scope_len);
+    else
+        ND_PRINT("%s/%d/%d", addrtostr6(padded, addr, INET6_ADDRSTRLEN),
+                src_len, scope_len);
+
+}
+
+extern const struct tok edns_opt2str[];
+extern const struct tok dau_alg2str[];
+extern const struct tok dhu_alg2str[];
+extern const struct tok n3u_alg2str[];
+
+
+/* print an <EDNS-option> */
+static const u_char *
+eopt_print(netdissect_options *ndo,
+          const u_char *cp)
+{
+    u_int opt, data_len, i;
+
+    if (!ND_TTEST_2(cp))
+        return (NULL);
+    opt = GET_BE_U_2(cp);
+    cp += 2;
+    ND_PRINT("%s", tok2str(edns_opt2str, "Opt%u", opt));
+    if (!ND_TTEST_2(cp))
+        return (NULL);
+    data_len = GET_BE_U_2(cp);
+    cp += 2;
+
+    ND_TCHECK_LEN(cp, data_len);
+
+    if (data_len > 0) {
+        ND_PRINT(" ");
+        switch (opt) {
+
+        case E_ECS:
+            print_eopt_ecs(ndo, cp, data_len);
+            break;
+        case E_COOKIE:
+            if (data_len < 8 || (data_len > 8 && data_len < 16) || data_len > 40)
+                nd_print_invalid(ndo);
+            else {
+                for (i = 0; i < data_len; ++i) {
+                    /* split client and server cookie */
+                    if (i == 8)
+                        ND_PRINT(" ");
+                    ND_PRINT("%02x", GET_U_1(cp + i));
+                }
+            }
+            break;
+        case E_KEEPALIVE:
+            if (data_len != 2)
+                nd_print_invalid(ndo);
+            else
+                /* keepalive is in increments of 100ms. Convert to seconds */
+                ND_PRINT("%0.1f sec", (GET_BE_U_2(cp) / 10.0));
+            break;
+        case E_EXPIRE:
+            if (data_len != 4)
+                nd_print_invalid(ndo);
+            else
+                ND_PRINT("%u sec", GET_BE_U_4(cp));
+            break;
+        case E_PADDING:
+            /* ignore contents and just print length */
+            ND_PRINT("(%u)", data_len);
+            break;
+        case E_KEYTAG:
+            if (data_len % 2 != 0)
+                nd_print_invalid(ndo);
+            else
+                for (i = 0; i < data_len; i += 2) {
+                    if (i > 0)
+                        ND_PRINT(" ");
+                    ND_PRINT("%u", GET_BE_U_2(cp + i));
+                }
+            break;
+        case E_DAU:
+            for (i = 0; i < data_len; ++i) {
+                if (i > 0)
+                    ND_PRINT(" ");
+                ND_PRINT("%s", tok2str(dau_alg2str, "Alg_%u", GET_U_1(cp + i)));
+            }
+            break;
+        case E_DHU:
+            for (i = 0; i < data_len; ++i) {
+                if (i > 0)
+                    ND_PRINT(" ");
+                ND_PRINT("%s", tok2str(dhu_alg2str, "Alg_%u", GET_U_1(cp + i)));
+            }
+            break;
+        case E_N3U:
+            for (i = 0; i < data_len; ++i) {
+                if (i > 0)
+                    ND_PRINT(" ");
+                ND_PRINT("%s", tok2str(n3u_alg2str, "Alg_%u", GET_U_1(cp + i)));
+            }
+            break;
+        case E_CHAIN:
+            fqdn_print(ndo, cp, cp + data_len);
+            break;
+        case E_NSID:
+            /* intentional fall-through. NSID is an undefined byte string */
+        default:
+            for (i = 0; i < data_len; ++i)
+                ND_PRINT("%02x", GET_U_1(cp + i));
+            break;
+        }
+    }
+    return (cp + data_len);
+
+  trunc:
+    return (NULL);
+
+}
+
+
+
 extern const struct tok ns_type2str[];
 
-/* http://www.iana.org/assignments/dns-parameters */
+/* https://www.iana.org/assignments/dns-parameters */
 const struct tok ns_type2str[] = {
 	{ T_A,		"A" },			/* RFC 1035 */
 	{ T_NS,		"NS" },			/* RFC 1035 */
@@ -332,6 +493,7 @@ const struct tok ns_type2str[] = {
 	{ T_MAILB,	"MAILB" },		/* RFC 1035 */
 	{ T_MAILA,	"MAILA" },		/* RFC 1035 */
 	{ T_ANY,	"ANY" },
+	{ T_URI,	"URI" },		/* RFC 7553 */
 	{ 0,		NULL }
 };
 
@@ -345,6 +507,59 @@ const struct tok ns_class2str[] = {
 	{ 0,		NULL }
 };
 
+const struct tok edns_opt2str[] = {
+    { E_LLQ,        "LLQ" },
+    { E_UL,         "UL" },
+    { E_NSID,       "NSID" },
+    { E_DAU,        "DAU" },
+    { E_DHU,        "DHU" },
+    { E_N3U,        "N3U" },
+    { E_ECS,        "ECS" },
+    { E_EXPIRE,     "EXPIRE" },
+    { E_COOKIE,     "COOKIE" },
+    { E_KEEPALIVE,  "KEEPALIVE" },
+    { E_PADDING,    "PADDING" },
+    { E_CHAIN,      "CHAIN" },
+    { E_KEYTAG,     "KEY-TAG" },
+    { E_CLIENTTAG,  "CLIENT-TAG" },
+    { E_SERVERTAG,  "SERVER-TAG" },
+    { 0,            NULL }
+};
+
+const struct tok dau_alg2str[] = {
+    { A_DELETE,             "DELETE" },
+    { A_RSAMD5,             "RSAMD5" },
+    { A_DH,                 "DH" },
+    { A_DSA,                "DS" },
+    { A_RSASHA1,            "RSASHA1" },
+    { A_DSA_NSEC3_SHA1,     "DSA-NSEC3-SHA1" },
+    { A_RSASHA1_NSEC3_SHA1, "RSASHA1-NSEC3-SHA1" },
+    { A_RSASHA256,          "RSASHA256" },
+    { A_RSASHA512,          "RSASHA512" },
+    { A_ECC_GOST,           "ECC-GOST" },
+    { A_ECDSAP256SHA256,    "ECDSAP256SHA256" },
+    { A_ECDSAP384SHA384,    "ECDSAP384SHA384" },
+    { A_ED25519,            "ED25519" },
+    { A_ED448,              "ED448" },
+    { A_INDIRECT,           "INDIRECT" },
+    { A_PRIVATEDNS,         "PRIVATEDNS" },
+    { A_PRIVATEOID,         "PRIVATEOID" },
+    { 0,                NULL }
+};
+
+const struct tok dhu_alg2str[] = {
+    { DS_SHA1,  "SHA-1" },
+    { DS_SHA256,"SHA-256" },
+    { DS_GOST,  "GOST_R_34.11-94" },
+    { DS_SHA384,"SHA-384" },
+    { 0,    NULL }
+};
+
+const struct tok n3u_alg2str[] = {
+    { NSEC_SHA1,"SHA-1" },
+    { 0,    NULL }
+};
+
 /* print a query */
 static const u_char *
 ns_qprint(netdissect_options *ndo,
@@ -359,11 +574,11 @@ ns_qprint(netdissect_options *ndo,
 		return(NULL);
 
 	/* print the qtype */
-	i = EXTRACT_BE_U_2(cp);
+	i = GET_BE_U_2(cp);
 	cp += 2;
 	ND_PRINT(" %s", tok2str(ns_type2str, "Type%u", i));
 	/* print the qclass (if it's not IN) */
-	i = EXTRACT_BE_U_2(cp);
+	i = GET_BE_U_2(cp);
 	cp += 2;
 	if (is_mdns)
 		class = (i & ~C_QU);
@@ -376,7 +591,7 @@ ns_qprint(netdissect_options *ndo,
 	}
 
 	ND_PRINT("? ");
-	cp = ns_nprint(ndo, np, bp);
+	cp = fqdn_print(ndo, np, bp);
 	return(cp ? cp + 4 : NULL);
 }
 
@@ -391,7 +606,7 @@ ns_rprint(netdissect_options *ndo,
 
 	if (ndo->ndo_vflag) {
 		ND_PRINT(" ");
-		if ((cp = ns_nprint(ndo, cp, bp)) == NULL)
+		if ((cp = fqdn_print(ndo, cp, bp)) == NULL)
 			return NULL;
 	} else
 		cp = ns_nskip(ndo, cp);
@@ -400,10 +615,10 @@ ns_rprint(netdissect_options *ndo,
 		return (ndo->ndo_snapend);
 
 	/* print the type/qtype */
-	typ = EXTRACT_BE_U_2(cp);
+	typ = GET_BE_U_2(cp);
 	cp += 2;
 	/* print the class (if it's not IN and the type isn't OPT) */
-	i = EXTRACT_BE_U_2(cp);
+	i = GET_BE_U_2(cp);
 	cp += 2;
 	if (is_mdns)
 		class = (i & ~C_CACHE_FLUSH);
@@ -419,13 +634,13 @@ ns_rprint(netdissect_options *ndo,
 	if (typ == T_OPT) {
 		/* get opt flags */
 		cp += 2;
-		opt_flags = EXTRACT_BE_U_2(cp);
+		opt_flags = GET_BE_U_2(cp);
 		/* ignore rest of ttl field */
 		cp += 2;
 	} else if (ndo->ndo_vflag > 2) {
 		/* print ttl */
 		ND_PRINT(" [");
-		unsigned_relts_print(ndo, EXTRACT_BE_U_4(cp));
+		unsigned_relts_print(ndo, GET_BE_U_4(cp));
 		ND_PRINT("]");
 		cp += 4;
 	} else {
@@ -433,7 +648,7 @@ ns_rprint(netdissect_options *ndo,
 		cp += 4;
 	}
 
-	len = EXTRACT_BE_U_2(cp);
+	len = GET_BE_U_2(cp);
 	cp += 2;
 
 	rp = cp + len;
@@ -446,7 +661,7 @@ ns_rprint(netdissect_options *ndo,
 	case T_A:
 		if (!ND_TTEST_LEN(cp, sizeof(nd_ipv4)))
 			return(NULL);
-		ND_PRINT(" %s", intoa(EXTRACT_IPV4_TO_NETWORK_ORDER(cp)));
+		ND_PRINT(" %s", intoa(GET_IPV4_TO_NETWORK_ORDER(cp)));
 		break;
 
 	case T_NS:
@@ -456,7 +671,7 @@ ns_rprint(netdissect_options *ndo,
 	case T_DNAME:
 #endif
 		ND_PRINT(" ");
-		if (ns_nprint(ndo, cp, bp) == NULL)
+		if (fqdn_print(ndo, cp, bp) == NULL)
 			return(NULL);
 		break;
 
@@ -464,31 +679,31 @@ ns_rprint(netdissect_options *ndo,
 		if (!ndo->ndo_vflag)
 			break;
 		ND_PRINT(" ");
-		if ((cp = ns_nprint(ndo, cp, bp)) == NULL)
+		if ((cp = fqdn_print(ndo, cp, bp)) == NULL)
 			return(NULL);
 		ND_PRINT(" ");
-		if ((cp = ns_nprint(ndo, cp, bp)) == NULL)
+		if ((cp = fqdn_print(ndo, cp, bp)) == NULL)
 			return(NULL);
 		if (!ND_TTEST_LEN(cp, 5 * 4))
 			return(NULL);
-		ND_PRINT(" %u", EXTRACT_BE_U_4(cp));
+		ND_PRINT(" %u", GET_BE_U_4(cp));
 		cp += 4;
-		ND_PRINT(" %u", EXTRACT_BE_U_4(cp));
+		ND_PRINT(" %u", GET_BE_U_4(cp));
 		cp += 4;
-		ND_PRINT(" %u", EXTRACT_BE_U_4(cp));
+		ND_PRINT(" %u", GET_BE_U_4(cp));
 		cp += 4;
-		ND_PRINT(" %u", EXTRACT_BE_U_4(cp));
+		ND_PRINT(" %u", GET_BE_U_4(cp));
 		cp += 4;
-		ND_PRINT(" %u", EXTRACT_BE_U_4(cp));
+		ND_PRINT(" %u", GET_BE_U_4(cp));
 		cp += 4;
 		break;
 	case T_MX:
 		ND_PRINT(" ");
 		if (!ND_TTEST_2(cp))
 			return(NULL);
-		if (ns_nprint(ndo, cp + 2, bp) == NULL)
+		if (fqdn_print(ndo, cp + 2, bp) == NULL)
 			return(NULL);
-		ND_PRINT(" %u", EXTRACT_BE_U_2(cp));
+		ND_PRINT(" %u", GET_BE_U_2(cp));
 		break;
 
 	case T_TXT:
@@ -505,10 +720,10 @@ ns_rprint(netdissect_options *ndo,
 		ND_PRINT(" ");
 		if (!ND_TTEST_6(cp))
 			return(NULL);
-		if (ns_nprint(ndo, cp + 6, bp) == NULL)
+		if (fqdn_print(ndo, cp + 6, bp) == NULL)
 			return(NULL);
-		ND_PRINT(":%u %u %u", EXTRACT_BE_U_2(cp + 4),
-			  EXTRACT_BE_U_2(cp), EXTRACT_BE_U_2(cp + 2));
+		ND_PRINT(":%u %u %u", GET_BE_U_2(cp + 4),
+			  GET_BE_U_2(cp), GET_BE_U_2(cp + 2));
 		break;
 
 	case T_AAAA:
@@ -525,13 +740,13 @@ ns_rprint(netdissect_options *ndo,
 
 	case T_A6:
 	    {
-		struct in6_addr a;
+		nd_ipv6 a;
 		int pbit, pbyte;
 		char ntop_buf[INET6_ADDRSTRLEN];
 
 		if (!ND_TTEST_1(cp))
 			return(NULL);
-		pbit = EXTRACT_U_1(cp);
+		pbit = GET_U_1(cp);
 		pbyte = (pbit & ~7) / 8;
 		if (pbit > 128) {
 			ND_PRINT(" %u(bad plen)", pbit);
@@ -539,23 +754,42 @@ ns_rprint(netdissect_options *ndo,
 		} else if (pbit < 128) {
 			if (!ND_TTEST_LEN(cp + 1, sizeof(a) - pbyte))
 				return(NULL);
-			memset(&a, 0, sizeof(a));
-			memcpy(&a.s6_addr[pbyte], cp + 1, sizeof(a) - pbyte);
+			memset(a, 0, sizeof(a));
+			memcpy(a + pbyte, cp + 1, sizeof(a) - pbyte);
 			ND_PRINT(" %u %s", pbit,
 			    addrtostr6(&a, ntop_buf, sizeof(ntop_buf)));
 		}
 		if (pbit > 0) {
 			ND_PRINT(" ");
-			if (ns_nprint(ndo, cp + 1 + sizeof(a) - pbyte, bp) == NULL)
+			if (fqdn_print(ndo, cp + 1 + sizeof(a) - pbyte, bp) == NULL)
 				return(NULL);
 		}
 		break;
 	    }
 
+	case T_URI:
+		if (!ND_TTEST_LEN(cp, len))
+			return(NULL);
+		ND_PRINT(" %u %u ", GET_BE_U_2(cp), GET_BE_U_2(cp + 2));
+		if (nd_printn(ndo, cp + 4, len - 4, ndo->ndo_snapend))
+			return(NULL);
+		break;
+
 	case T_OPT:
 		ND_PRINT(" UDPsize=%u", class);
 		if (opt_flags & 0x8000)
 			ND_PRINT(" DO");
+        if (cp < rp) {
+            ND_PRINT(" [");
+            while (cp < rp) {
+                cp = eopt_print(ndo, cp);
+                if (cp == NULL)
+                    return(NULL);
+                if (cp < rp)
+                    ND_PRINT(",");
+            }
+            ND_PRINT("]");
+        }
 		break;
 
 	case T_UNSPECA:		/* One long string */
@@ -572,28 +806,28 @@ ns_rprint(netdissect_options *ndo,
 		if (!ndo->ndo_vflag)
 			break;
 		ND_PRINT(" ");
-		if ((cp = ns_nprint(ndo, cp, bp)) == NULL)
+		if ((cp = fqdn_print(ndo, cp, bp)) == NULL)
 			return(NULL);
 		cp += 6;
 		if (!ND_TTEST_2(cp))
 			return(NULL);
-		ND_PRINT(" fudge=%u", EXTRACT_BE_U_2(cp));
+		ND_PRINT(" fudge=%u", GET_BE_U_2(cp));
 		cp += 2;
 		if (!ND_TTEST_2(cp))
 			return(NULL);
-		ND_PRINT(" maclen=%u", EXTRACT_BE_U_2(cp));
-		cp += 2 + EXTRACT_BE_U_2(cp);
+		ND_PRINT(" maclen=%u", GET_BE_U_2(cp));
+		cp += 2 + GET_BE_U_2(cp);
 		if (!ND_TTEST_2(cp))
 			return(NULL);
-		ND_PRINT(" origid=%u", EXTRACT_BE_U_2(cp));
+		ND_PRINT(" origid=%u", GET_BE_U_2(cp));
 		cp += 2;
 		if (!ND_TTEST_2(cp))
 			return(NULL);
-		ND_PRINT(" error=%u", EXTRACT_BE_U_2(cp));
+		ND_PRINT(" error=%u", GET_BE_U_2(cp));
 		cp += 2;
 		if (!ND_TTEST_2(cp))
 			return(NULL);
-		ND_PRINT(" otherlen=%u", EXTRACT_BE_U_2(cp));
+		ND_PRINT(" otherlen=%u", GET_BE_U_2(cp));
 		cp += 2;
 	    }
 	}
@@ -602,7 +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;
@@ -612,14 +846,50 @@ 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)) {
+		nd_print_protocol(ndo);
+		ND_PRINT(" [length %u < %zu]", length, sizeof(*np));
+		nd_print_invalid(ndo);
+		return;
+	}
+
 	ND_TCHECK_SIZE(np);
-	flags = EXTRACT_BE_U_2(np->flags);
+	flags = GET_BE_U_2(np->flags);
 	/* get the byte-order right */
-	qdcount = EXTRACT_BE_U_2(np->qdcount);
-	ancount = EXTRACT_BE_U_2(np->ancount);
-	nscount = EXTRACT_BE_U_2(np->nscount);
-	arcount = EXTRACT_BE_U_2(np->arcount);
+	qdcount = GET_BE_U_2(np->qdcount);
+	ancount = GET_BE_U_2(np->ancount);
+	nscount = GET_BE_U_2(np->nscount);
+	arcount = GET_BE_U_2(np->arcount);
 
 	/* find the opt record to extract extended rcode */
 	cp = (const u_char *)(np + 1);
@@ -637,7 +907,7 @@ domain_print(netdissect_options *ndo,
 		cp += 8;	/* skip TYPE, CLASS and TTL */
 		if (cp + 2 > ndo->ndo_snapend)
 			goto print;
-		rdlen = EXTRACT_BE_U_2(cp);
+		rdlen = GET_BE_U_2(cp);
 		cp += 2 + rdlen;
 		if (cp >= ndo->ndo_snapend)
 			goto print;
@@ -647,18 +917,18 @@ domain_print(netdissect_options *ndo,
 			goto print;
 		if (cp + 2 > ndo->ndo_snapend)
 			goto print;
-		type = EXTRACT_BE_U_2(cp);
+		type = GET_BE_U_2(cp);
 		cp += 4;	/* skip TYPE and CLASS */
 		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;
 		if (cp + 2 > ndo->ndo_snapend)
 			goto print;
-		rdlen = EXTRACT_BE_U_2(cp);
+		rdlen = GET_BE_U_2(cp);
 		cp += 2 + rdlen;
 		if (cp >= ndo->ndo_snapend)
 			goto print;
@@ -668,7 +938,7 @@ domain_print(netdissect_options *ndo,
 	if (DNS_QR(flags)) {
 		/* this is a response */
 		ND_PRINT("%u%s%s%s%s%s%s",
-			EXTRACT_BE_U_2(np->id),
+			GET_BE_U_2(np->id),
 			ns_ops[DNS_OPCODE(flags)],
 			ns_rcode(rcode),
 			DNS_AA(flags)? "*" : "",
@@ -741,12 +1011,13 @@ domain_print(netdissect_options *ndo,
 	}
 	else {
 		/* this is a request */
-		ND_PRINT("%u%s%s%s", EXTRACT_BE_U_2(np->id), ns_ops[DNS_OPCODE(flags)],
+		ND_PRINT("%u%s%s%s", GET_BE_U_2(np->id),
+			  ns_ops[DNS_OPCODE(flags)],
 			  DNS_RD(flags) ? "+" : "",
 			  DNS_CD(flags) ? "%" : "");
 
 		/* any weirdness? */
-		b2 = EXTRACT_BE_U_2(((const u_short *)np) + 1);
+		b2 = GET_BE_U_2(((const u_short *)np) + 1);
 		if (b2 & 0x6cf)
 			ND_PRINT(" [b2&3=0x%x]", b2);