Adding upstream version 4.99.4.upstream/4.99.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1171 insertions, 0 deletions

diff --git a/print-domain.c b/print-domain.c
new file mode 100644
index 0000000..d2275a5
--- /dev/null
+++ b/print-domain.c
@@ -0,0 +1,1171 @@
+/*
+ * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that: (1) source code distributions
+ * retain the above copyright notice and this paragraph in its entirety, (2)
+ * distributions including binary code include the above copyright notice and
+ * this paragraph in its entirety in the documentation or other materials
+ * provided with the distribution, and (3) all advertising materials mentioning
+ * features or use of this software display the following acknowledgement:
+ * ``This product includes software developed by the University of California,
+ * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
+ * the University nor the names of its contributors may be used to endorse
+ * or promote products derived from this software without specific prior
+ * written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+/* \summary: Domain Name System (DNS) printer */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "netdissect-stdinc.h"
+
+#include <string.h>
+
+#include "netdissect.h"
+#include "addrtoname.h"
+#include "addrtostr.h"
+#include "extract.h"
+
+#include "nameser.h"
+
+static const char *ns_ops[] = {
+	"", " inv_q", " stat", " op3", " notify", " update", " op6", " op7",
+	" op8", " updateA", " updateD", " updateDA",
+	" updateM", " updateMA", " zoneInit", " zoneRef",
+};
+
+static const char *ns_resp[] = {
+	"", " FormErr", " ServFail", " NXDomain",
+	" NotImp", " Refused", " YXDomain", " YXRRSet",
+	" NXRRSet", " NotAuth", " NotZone", " Resp11",
+	" Resp12", " Resp13", " Resp14", " NoChange",
+	" BadVers", "Resp17", " Resp18", " Resp19",
+	" Resp20", "Resp21", " Resp22", " BadCookie",
+};
+
+static const char *
+ns_rcode(u_int rcode) {
+	static char buf[sizeof(" Resp4095")];
+
+	if (rcode < sizeof(ns_resp)/sizeof(ns_resp[0])) {
+		return (ns_resp[rcode]);
+	}
+	snprintf(buf, sizeof(buf), " Resp%u", rcode & 0xfff);
+	return (buf);
+}
+
+/* skip over a domain name */
+static const u_char *
+ns_nskip(netdissect_options *ndo,
+         const u_char *cp)
+{
+	u_char i;
+
+	if (!ND_TTEST_1(cp))
+		return (NULL);
+	i = GET_U_1(cp);
+	cp++;
+	while (i) {
+		switch (i & TYPE_MASK) {
+
+		case TYPE_INDIR:
+			return (cp + 1);
+
+		case TYPE_EDNS0: {
+			int bitlen, bytelen;
+
+			if ((i & ~TYPE_MASK) != EDNS0_ELT_BITLABEL)
+				return(NULL); /* unknown ELT */
+			if (!ND_TTEST_1(cp))
+				return (NULL);
+			if ((bitlen = GET_U_1(cp)) == 0)
+				bitlen = 256;
+			cp++;
+			bytelen = (bitlen + 7) / 8;
+			cp += bytelen;
+		}
+		break;
+
+		case TYPE_RESERVED:
+			return (NULL);
+
+		case TYPE_LABEL:
+			cp += i;
+			break;
+		}
+		if (!ND_TTEST_1(cp))
+			return (NULL);
+		i = GET_U_1(cp);
+		cp++;
+	}
+	return (cp);
+}
+
+static const u_char *
+blabel_print(netdissect_options *ndo,
+             const u_char *cp)
+{
+	u_int bitlen, slen, b;
+	const u_char *bitp, *lim;
+	uint8_t tc;
+
+	if (!ND_TTEST_1(cp))
+		return(NULL);
+	if ((bitlen = GET_U_1(cp)) == 0)
+		bitlen = 256;
+	slen = (bitlen + 3) / 4;
+	lim = cp + 1 + slen;
+
+	/* 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_PRINT("%02x", GET_U_1(bitp));
+	}
+	if (b > 4) {
+		tc = GET_U_1(bitp);
+		bitp++;
+		ND_PRINT("%02x", tc & (0xff << (8 - b)));
+	} else if (b > 0) {
+		tc = GET_U_1(bitp);
+		bitp++;
+		ND_PRINT("%1x", ((tc >> 4) & 0x0f) & (0x0f << (4 - b)));
+	}
+	ND_PRINT("/%u]", bitlen);
+	return lim;
+}
+
+static int
+labellen(netdissect_options *ndo,
+         const u_char *cp)
+{
+	u_int i;
+
+	if (!ND_TTEST_1(cp))
+		return(-1);
+	i = GET_U_1(cp);
+	switch (i & TYPE_MASK) {
+
+	case TYPE_EDNS0: {
+		u_int bitlen, elt;
+		if ((elt = (i & ~TYPE_MASK)) != EDNS0_ELT_BITLABEL) {
+			ND_PRINT("<ELT %d>", elt);
+			return(-1);
+		}
+		if (!ND_TTEST_1(cp + 1))
+			return(-1);
+		if ((bitlen = GET_U_1(cp + 1)) == 0)
+			bitlen = 256;
+		return(((bitlen + 7) / 8) + 1);
+	}
+
+	case TYPE_INDIR:
+	case TYPE_LABEL:
+		return(i);
+
+	default:
+		/*
+		 * TYPE_RESERVED, but we use default to suppress compiler
+		 * warnings about falling out of the switch statement.
+		 */
+		ND_PRINT("<BAD LABEL TYPE>");
+		return(-1);
+	}
+}
+
+/* print a <domain-name> */
+const u_char *
+fqdn_print(netdissect_options *ndo,
+          const u_char *cp, const u_char *bp)
+{
+	u_int i, l;
+	const u_char *rp = NULL;
+	int compress = 0;
+	u_int elt;
+	u_int offset, max_offset;
+	u_int name_chars = 0;
+
+	if ((l = labellen(ndo, cp)) == (u_int)-1)
+		return(NULL);
+	if (!ND_TTEST_1(cp))
+		return(NULL);
+	max_offset = (u_int)(cp - bp);
+	i = GET_U_1(cp);
+	cp++;
+	if ((i & TYPE_MASK) != TYPE_INDIR) {
+		compress = 0;
+		rp = cp + l;
+	}
+
+	if (i != 0) {
+		while (i && cp < ndo->ndo_snapend) {
+			switch (i & TYPE_MASK) {
+
+			case TYPE_INDIR:
+				if (!compress) {
+					rp = cp + 1;
+					compress = 1;
+				}
+				if (!ND_TTEST_1(cp))
+					return(NULL);
+				offset = (((i << 8) | GET_U_1(cp)) & 0x3fff);
+				/*
+				 * This must move backwards in the packet.
+				 * No RFC explicitly says that, but BIND's
+				 * name decompression code requires it,
+				 * as a way of preventing infinite loops
+				 * and other bad behavior, and it's probably
+				 * what was intended (compress by pointing
+				 * to domain name suffixes already seen in
+				 * the packet).
+				 */
+				if (offset >= max_offset) {
+					ND_PRINT("<BAD PTR>");
+					return(NULL);
+				}
+				max_offset = offset;
+				cp = bp + offset;
+				if (!ND_TTEST_1(cp))
+					return(NULL);
+				i = GET_U_1(cp);
+				if ((l = labellen(ndo, cp)) == (u_int)-1)
+					return(NULL);
+				cp++;
+				continue;
+
+			case TYPE_EDNS0:
+				elt = (i & ~TYPE_MASK);
+				switch(elt) {
+				case EDNS0_ELT_BITLABEL:
+					if (blabel_print(ndo, cp) == NULL)
+						return (NULL);
+					break;
+				default:
+					/* unknown ELT */
+					ND_PRINT("<ELT %u>", elt);
+					return(NULL);
+				}
+				break;
+
+			case TYPE_RESERVED:
+				ND_PRINT("<BAD LABEL TYPE>");
+				return(NULL);
+
+			case TYPE_LABEL:
+				if (name_chars + l <= MAXCDNAME) {
+					if (nd_printn(ndo, cp, l, ndo->ndo_snapend))
+						return(NULL);
+				} else if (name_chars < MAXCDNAME) {
+					if (nd_printn(ndo, cp,
+					    MAXCDNAME - name_chars, ndo->ndo_snapend))
+						return(NULL);
+				}
+				name_chars += l;
+				break;
+			}
+
+			cp += l;
+			if (name_chars <= MAXCDNAME)
+				ND_PRINT(".");
+			name_chars++;
+			if (!ND_TTEST_1(cp))
+				return(NULL);
+			i = GET_U_1(cp);
+			if ((l = labellen(ndo, cp)) == (u_int)-1)
+				return(NULL);
+			cp++;
+			if (!compress)
+				rp += l + 1;
+		}
+		if (name_chars > MAXCDNAME)
+			ND_PRINT("<DOMAIN NAME TOO LONG>");
+	} else
+		ND_PRINT(".");
+	return (rp);
+}
+
+/* print a <character-string> */
+static const u_char *
+ns_cprint(netdissect_options *ndo,
+          const u_char *cp)
+{
+	u_int i;
+
+	if (!ND_TTEST_1(cp))
+		return (NULL);
+	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[];
+
+/* https://www.iana.org/assignments/dns-parameters */
+const struct tok ns_type2str[] = {
+	{ T_A,		"A" },			/* RFC 1035 */
+	{ T_NS,		"NS" },			/* RFC 1035 */
+	{ T_MD,		"MD" },			/* RFC 1035 */
+	{ T_MF,		"MF" },			/* RFC 1035 */
+	{ T_CNAME,	"CNAME" },		/* RFC 1035 */
+	{ T_SOA,	"SOA" },		/* RFC 1035 */
+	{ T_MB,		"MB" },			/* RFC 1035 */
+	{ T_MG,		"MG" },			/* RFC 1035 */
+	{ T_MR,		"MR" },			/* RFC 1035 */
+	{ T_NULL,	"NULL" },		/* RFC 1035 */
+	{ T_WKS,	"WKS" },		/* RFC 1035 */
+	{ T_PTR,	"PTR" },		/* RFC 1035 */
+	{ T_HINFO,	"HINFO" },		/* RFC 1035 */
+	{ T_MINFO,	"MINFO" },		/* RFC 1035 */
+	{ T_MX,		"MX" },			/* RFC 1035 */
+	{ T_TXT,	"TXT" },		/* RFC 1035 */
+	{ T_RP,		"RP" },			/* RFC 1183 */
+	{ T_AFSDB,	"AFSDB" },		/* RFC 5864 */
+	{ T_X25,	"X25" },		/* RFC 1183 */
+	{ T_ISDN,	"ISDN" },		/* RFC 1183 */
+	{ T_RT,		"RT" },			/* RFC 1183 */
+	{ T_NSAP,	"NSAP" },		/* RFC 1706 */
+	{ T_NSAP_PTR,	"NSAP_PTR" },		/* RFC 1706 */
+	{ T_SIG,	"SIG" },		/* RFC 3008 */
+	{ T_KEY,	"KEY" },		/* RFC 3110 */
+	{ T_PX,		"PX" },			/* RFC 2163 */
+	{ T_GPOS,	"GPOS" },		/* RFC 1712 */
+	{ T_AAAA,	"AAAA" },		/* RFC 3596 */
+	{ T_LOC,	"LOC" },		/* RFC 1876 */
+	{ T_NXT,	"NXT" },		/* RFC 3755 */
+	{ T_EID,	"EID" },		/* Nimrod */
+	{ T_NIMLOC,	"NIMLOC" },		/* Nimrod */
+	{ T_SRV,	"SRV" },		/* RFC 2782 */
+	{ T_ATMA,	"ATMA" },		/* ATM Forum */
+	{ T_NAPTR,	"NAPTR" },		/* RFC 3403 */
+	{ T_KX,		"KX" },			/* RFC 2230 */
+	{ T_CERT,	"CERT" },		/* RFC 4398 */
+	{ T_A6,		"A6" },			/* RFC 6563 */
+	{ T_DNAME,	"DNAME" },		/* RFC 6672 */
+	{ T_SINK,	"SINK" },
+	{ T_OPT,	"OPT" },		/* RFC 6891 */
+	{ T_APL,	"APL" },		/* RFC 3123 */
+	{ T_DS,		"DS" },			/* RFC 4034 */
+	{ T_SSHFP,	"SSHFP" },		/* RFC 4255 */
+	{ T_IPSECKEY,	"IPSECKEY" },		/* RFC 4025 */
+	{ T_RRSIG,	"RRSIG" },		/* RFC 4034 */
+	{ T_NSEC,	"NSEC" },		/* RFC 4034 */
+	{ T_DNSKEY,	"DNSKEY" },		/* RFC 4034 */
+	{ T_DHCID,	"DHCID" },		/* RFC 4071 */
+	{ T_NSEC3,	"NSEC3" },		/* RFC 5155 */
+	{ T_NSEC3PARAM,	"NSEC3PARAM" },		/* RFC 5155 */
+	{ T_TLSA,	"TLSA" },		/* RFC 6698 */
+	{ T_SMIMEA,	"SMIMEA" },		/* RFC 8162 */
+	{ T_HIP,	"HIP" },		/* RFC 8005 */
+	{ T_NINFO,	"NINFO" },
+	{ T_RKEY,	"RKEY" },
+	{ T_TALINK,	"TALINK" },
+	{ T_CDS,	"CDS" },		/* RFC 7344 */
+	{ T_CDNSKEY,	"CDNSKEY" },		/* RFC 7344 */
+	{ T_OPENPGPKEY,	"OPENPGPKEY" },		/* RFC 7929 */
+	{ T_CSYNC,	"CSYNC" },		/* RFC 7477 */
+	{ T_ZONEMD,	"ZONEMD" },		/* RFC 8976 */
+	{ T_SVCB,	"SVCB" },
+	{ T_HTTPS,	"HTTPS" },
+	{ T_SPF,	"SPF" },		/* RFC 7208 */
+	{ T_UINFO,	"UINFO" },
+	{ T_UID,	"UID" },
+	{ T_GID,	"GID" },
+	{ T_UNSPEC,	"UNSPEC" },
+	{ T_NID,	"NID" },		/* RFC 6742 */
+	{ T_L32,	"L32" },		/* RFC 6742 */
+	{ T_L64,	"L64" },		/* RFC 6742 */
+	{ T_LP,		"LP" },			/* RFC 6742 */
+	{ T_EUI48,	"EUI48" },		/* RFC 7043 */
+	{ T_EUI64,	"EUI64" },		/* RFC 7043 */
+	{ T_TKEY,	"TKEY" },		/* RFC 2930 */
+	{ T_TSIG,	"TSIG" },		/* RFC 8945 */
+	{ T_IXFR,	"IXFR" },		/* RFC 1995 */
+	{ T_AXFR,	"AXFR" },		/* RFC 5936 */
+	{ T_MAILB,	"MAILB" },		/* RFC 1035 */
+	{ T_MAILA,	"MAILA" },		/* RFC 1035 */
+	{ T_ANY,	"ANY" },		/* RFC 8482 */
+	{ T_URI,	"URI" },		/* RFC 7553 */
+	{ T_CAA,	"CAA" },		/* RFC 8659 */
+	{ T_AVC,	"AVC" },
+	{ T_DOA,	"DOA" },
+	{ T_AMTRELAY,	"AMTRELAY" },		/* RFC 8777 */
+	{ T_TA,		"TA" },
+	{ T_DLV,	"DLV" },		/* RFC 8749 */
+	{ 0,		NULL }
+};
+
+extern const struct tok ns_class2str[];
+
+const struct tok ns_class2str[] = {
+	{ C_IN,		"IN" },		/* Not used */
+	{ C_CHAOS,	"CHAOS" },
+	{ C_HS,		"HS" },
+	{ C_ANY,	"ANY" },
+	{ 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,
+          const u_char *cp, const u_char *bp, int is_mdns)
+{
+	const u_char *np = cp;
+	u_int i, class;
+
+	cp = ns_nskip(ndo, cp);
+
+	if (cp == NULL || !ND_TTEST_4(cp))
+		return(NULL);
+
+	/* print the qtype */
+	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 = GET_BE_U_2(cp);
+	cp += 2;
+	if (is_mdns)
+		class = (i & ~C_QU);
+	else
+		class = i;
+	if (class != C_IN)
+		ND_PRINT(" %s", tok2str(ns_class2str, "(Class %u)", class));
+	if (is_mdns) {
+		ND_PRINT(i & C_QU ? " (QU)" : " (QM)");
+	}
+
+	ND_PRINT("? ");
+	cp = fqdn_print(ndo, np, bp);
+	return(cp ? cp + 4 : NULL);
+}
+
+/* print a reply */
+static const u_char *
+ns_rprint(netdissect_options *ndo,
+          const u_char *cp, const u_char *bp, int is_mdns)
+{
+	u_int i, class, opt_flags = 0;
+	u_short typ, len;
+	const u_char *rp;
+
+	if (ndo->ndo_vflag) {
+		ND_PRINT(" ");
+		if ((cp = fqdn_print(ndo, cp, bp)) == NULL)
+			return NULL;
+	} else
+		cp = ns_nskip(ndo, cp);
+
+	if (cp == NULL || !ND_TTEST_LEN(cp, 10))
+		return (ndo->ndo_snapend);
+
+	/* print the type/qtype */
+	typ = GET_BE_U_2(cp);
+	cp += 2;
+	/* print the class (if it's not IN and the type isn't OPT) */
+	i = GET_BE_U_2(cp);
+	cp += 2;
+	if (is_mdns)
+		class = (i & ~C_CACHE_FLUSH);
+	else
+		class = i;
+	if (class != C_IN && typ != T_OPT)
+		ND_PRINT(" %s", tok2str(ns_class2str, "(Class %u)", class));
+	if (is_mdns) {
+		if (i & C_CACHE_FLUSH)
+			ND_PRINT(" (Cache flush)");
+	}
+
+	if (typ == T_OPT) {
+		/* get opt flags */
+		cp += 2;
+		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, GET_BE_U_4(cp));
+		ND_PRINT("]");
+		cp += 4;
+	} else {
+		/* ignore ttl */
+		cp += 4;
+	}
+
+	len = GET_BE_U_2(cp);
+	cp += 2;
+
+	rp = cp + len;
+
+	ND_PRINT(" %s", tok2str(ns_type2str, "Type%u", typ));
+	if (rp > ndo->ndo_snapend)
+		return(NULL);
+
+	switch (typ) {
+	case T_A:
+		if (!ND_TTEST_LEN(cp, sizeof(nd_ipv4)))
+			return(NULL);
+		ND_PRINT(" %s", intoa(GET_IPV4_TO_NETWORK_ORDER(cp)));
+		break;
+
+	case T_NS:
+	case T_CNAME:
+	case T_PTR:
+	case T_DNAME:
+		ND_PRINT(" ");
+		if (fqdn_print(ndo, cp, bp) == NULL)
+			return(NULL);
+		break;
+
+	case T_SOA:
+		if (!ndo->ndo_vflag)
+			break;
+		ND_PRINT(" ");
+		if ((cp = fqdn_print(ndo, cp, bp)) == NULL)
+			return(NULL);
+		ND_PRINT(" ");
+		if ((cp = fqdn_print(ndo, cp, bp)) == NULL)
+			return(NULL);
+		if (!ND_TTEST_LEN(cp, 5 * 4))
+			return(NULL);
+		ND_PRINT(" %u", GET_BE_U_4(cp));
+		cp += 4;
+		ND_PRINT(" %u", GET_BE_U_4(cp));
+		cp += 4;
+		ND_PRINT(" %u", GET_BE_U_4(cp));
+		cp += 4;
+		ND_PRINT(" %u", GET_BE_U_4(cp));
+		cp += 4;
+		ND_PRINT(" %u", GET_BE_U_4(cp));
+		cp += 4;
+		break;
+	case T_MX:
+		ND_PRINT(" ");
+		if (!ND_TTEST_2(cp))
+			return(NULL);
+		if (fqdn_print(ndo, cp + 2, bp) == NULL)
+			return(NULL);
+		ND_PRINT(" %u", GET_BE_U_2(cp));
+		break;
+
+	case T_TXT:
+		while (cp < rp) {
+			ND_PRINT(" \"");
+			cp = ns_cprint(ndo, cp);
+			if (cp == NULL)
+				return(NULL);
+			ND_PRINT("\"");
+		}
+		break;
+
+	case T_SRV:
+		ND_PRINT(" ");
+		if (!ND_TTEST_6(cp))
+			return(NULL);
+		if (fqdn_print(ndo, cp + 6, bp) == NULL)
+			return(NULL);
+		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:
+	    {
+		char ntop_buf[INET6_ADDRSTRLEN];
+
+		if (!ND_TTEST_LEN(cp, sizeof(nd_ipv6)))
+			return(NULL);
+		ND_PRINT(" %s",
+		    addrtostr6(cp, ntop_buf, sizeof(ntop_buf)));
+
+		break;
+	    }
+
+	case T_A6:
+	    {
+		nd_ipv6 a;
+		int pbit, pbyte;
+		char ntop_buf[INET6_ADDRSTRLEN];
+
+		if (!ND_TTEST_1(cp))
+			return(NULL);
+		pbit = GET_U_1(cp);
+		pbyte = (pbit & ~7) / 8;
+		if (pbit > 128) {
+			ND_PRINT(" %u(bad plen)", pbit);
+			break;
+		} else if (pbit < 128) {
+			memset(a, 0, sizeof(a));
+			GET_CPY_BYTES(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 (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_TSIG:
+	    {
+		if (cp + len > ndo->ndo_snapend)
+			return(NULL);
+		if (!ndo->ndo_vflag)
+			break;
+		ND_PRINT(" ");
+		if ((cp = fqdn_print(ndo, cp, bp)) == NULL)
+			return(NULL);
+		cp += 6;
+		if (!ND_TTEST_2(cp))
+			return(NULL);
+		ND_PRINT(" fudge=%u", GET_BE_U_2(cp));
+		cp += 2;
+		if (!ND_TTEST_2(cp))
+			return(NULL);
+		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", GET_BE_U_2(cp));
+		cp += 2;
+		if (!ND_TTEST_2(cp))
+			return(NULL);
+		ND_PRINT(" error=%u", GET_BE_U_2(cp));
+		cp += 2;
+		if (!ND_TTEST_2(cp))
+			return(NULL);
+		ND_PRINT(" otherlen=%u", GET_BE_U_2(cp));
+		cp += 2;
+	    }
+	}
+	return (rp);		/* XXX This isn't always right */
+}
+
+void
+domain_print(netdissect_options *ndo,
+             const u_char *bp, u_int length, int over_tcp, int is_mdns)
+{
+	const dns_header_t *np;
+	uint16_t flags, rcode, rdlen, type;
+	u_int qdcount, ancount, nscount, arcount;
+	u_int i;
+	const u_char *cp;
+	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 = GET_BE_U_2(np->flags);
+	/* get the byte-order right */
+	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);
+	rcode = DNS_RCODE(flags);
+	for (i = 0; i < qdcount; i++) {
+		if ((cp = ns_nskip(ndo, cp)) == NULL)
+			goto print;
+		cp += 4;	/* skip QTYPE and QCLASS */
+		if (cp >= ndo->ndo_snapend)
+			goto print;
+	}
+	for (i = 0; i < ancount + nscount; i++) {
+		if ((cp = ns_nskip(ndo, cp)) == NULL)
+			goto print;
+		cp += 8;	/* skip TYPE, CLASS and TTL */
+		if (cp + 2 > ndo->ndo_snapend)
+			goto print;
+		rdlen = GET_BE_U_2(cp);
+		cp += 2 + rdlen;
+		if (cp >= ndo->ndo_snapend)
+			goto print;
+	}
+	for (i = 0; i < arcount; i++) {
+		if ((cp = ns_nskip(ndo, cp)) == NULL)
+			goto print;
+		if (cp + 2 > ndo->ndo_snapend)
+			goto print;
+		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 |= (GET_U_1(cp) << 4);
+			goto print;
+		}
+		cp += 4;
+		if (cp + 2 > ndo->ndo_snapend)
+			goto print;
+		rdlen = GET_BE_U_2(cp);
+		cp += 2 + rdlen;
+		if (cp >= ndo->ndo_snapend)
+			goto print;
+	}
+
+ print:
+	if (DNS_QR(flags)) {
+		/* this is a response */
+		ND_PRINT("%u%s%s%s%s%s%s",
+			GET_BE_U_2(np->id),
+			ns_ops[DNS_OPCODE(flags)],
+			ns_rcode(rcode),
+			DNS_AA(flags)? "*" : "",
+			DNS_RA(flags)? "" : "-",
+			DNS_TC(flags)? "|" : "",
+			DNS_AD(flags)? "$" : "");
+
+		if (qdcount != 1)
+			ND_PRINT(" [%uq]", qdcount);
+		/* Print QUESTION section on -vv */
+		cp = (const u_char *)(np + 1);
+		for (i = 0; i < qdcount; i++) {
+			if (i != 0)
+				ND_PRINT(",");
+			if (ndo->ndo_vflag > 1) {
+				ND_PRINT(" q:");
+				if ((cp = ns_qprint(ndo, cp, bp, is_mdns)) == NULL)
+					goto trunc;
+			} else {
+				if ((cp = ns_nskip(ndo, cp)) == NULL)
+					goto trunc;
+				cp += 4;	/* skip QTYPE and QCLASS */
+			}
+		}
+		ND_PRINT(" %u/%u/%u", ancount, nscount, arcount);
+		if (ancount) {
+			if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
+				goto trunc;
+			ancount--;
+			while (cp < ndo->ndo_snapend && ancount) {
+				ND_PRINT(",");
+				if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
+					goto trunc;
+				ancount--;
+			}
+		}
+		if (ancount)
+			goto trunc;
+		/* Print NS and AR sections on -vv */
+		if (ndo->ndo_vflag > 1) {
+			if (cp < ndo->ndo_snapend && nscount) {
+				ND_PRINT(" ns:");
+				if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
+					goto trunc;
+				nscount--;
+				while (cp < ndo->ndo_snapend && nscount) {
+					ND_PRINT(",");
+					if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
+						goto trunc;
+					nscount--;
+				}
+			}
+			if (nscount)
+				goto trunc;
+			if (cp < ndo->ndo_snapend && arcount) {
+				ND_PRINT(" ar:");
+				if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
+					goto trunc;
+				arcount--;
+				while (cp < ndo->ndo_snapend && arcount) {
+					ND_PRINT(",");
+					if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
+						goto trunc;
+					arcount--;
+				}
+			}
+			if (arcount)
+				goto trunc;
+		}
+	}
+	else {
+		/* this is a request */
+		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 = GET_BE_U_2(((const u_short *)np) + 1);
+		if (b2 & 0x6cf)
+			ND_PRINT(" [b2&3=0x%x]", b2);
+
+		if (DNS_OPCODE(flags) == IQUERY) {
+			if (qdcount)
+				ND_PRINT(" [%uq]", qdcount);
+			if (ancount != 1)
+				ND_PRINT(" [%ua]", ancount);
+		}
+		else {
+			if (ancount)
+				ND_PRINT(" [%ua]", ancount);
+			if (qdcount != 1)
+				ND_PRINT(" [%uq]", qdcount);
+		}
+		if (nscount)
+			ND_PRINT(" [%un]", nscount);
+		if (arcount)
+			ND_PRINT(" [%uau]", arcount);
+
+		cp = (const u_char *)(np + 1);
+		if (qdcount) {
+			cp = ns_qprint(ndo, cp, (const u_char *)np, is_mdns);
+			if (!cp)
+				goto trunc;
+			qdcount--;
+			while (cp < ndo->ndo_snapend && qdcount) {
+				cp = ns_qprint(ndo, (const u_char *)cp,
+					       (const u_char *)np,
+					       is_mdns);
+				if (!cp)
+					goto trunc;
+				qdcount--;
+			}
+		}
+		if (qdcount)
+			goto trunc;
+
+		/* Print remaining sections on -vv */
+		if (ndo->ndo_vflag > 1) {
+			if (ancount) {
+				if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
+					goto trunc;
+				ancount--;
+				while (cp < ndo->ndo_snapend && ancount) {
+					ND_PRINT(",");
+					if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
+						goto trunc;
+					ancount--;
+				}
+			}
+			if (ancount)
+				goto trunc;
+			if (cp < ndo->ndo_snapend && nscount) {
+				ND_PRINT(" ns:");
+				if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
+					goto trunc;
+				nscount--;
+				while (cp < ndo->ndo_snapend && nscount) {
+					ND_PRINT(",");
+					if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
+						goto trunc;
+					nscount--;
+				}
+			}
+			if (nscount > 0)
+				goto trunc;
+			if (cp < ndo->ndo_snapend && arcount) {
+				ND_PRINT(" ar:");
+				if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
+					goto trunc;
+				arcount--;
+				while (cp < ndo->ndo_snapend && arcount) {
+					ND_PRINT(",");
+					if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
+						goto trunc;
+					arcount--;
+				}
+			}
+			if (arcount)
+				goto trunc;
+		}
+	}
+	ND_PRINT(" (%u)", length);
+	return;
+
+  trunc:
+	nd_print_trunc(ndo);
+}