]> The Tcpdump Group git mirrors - tcpdump/blobdiff - print-domain.c
More UNALIGNED_MEM{CPY,CMP} on IP addresses.
[tcpdump] / print-domain.c
index b51731fc312037ddd2985225ea2830ae783bc9d7..9c229e033f4f0041f0602723935bfe39cd7d06e1 100644 (file)
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  */
 
-#ifndef lint
-static const char rcsid[] =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-domain.c,v 1.70 2001-02-20 06:03:42 itojun Exp $ (LBL)";
-#endif
-
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
-#include <sys/param.h>
-#include <sys/time.h>
+#include <tcpdump-stdinc.h>
 
-#include <netinet/in.h>
-
-#ifdef NOERROR
-#undef NOERROR                                 /* Solaris sucks */
-#endif
-#ifdef NOERROR
-#undef T_UNSPEC                                        /* SINIX does too */
-#endif
 #include "nameser.h"
 
 #include <stdio.h>
@@ -48,43 +34,46 @@ static const char rcsid[] =
 #include "addrtoname.h"
 #include "extract.h"                    /* must come after interface.h */
 
-static char *ns_ops[] = {
-       "", " inv_q", " stat", " op3", " notify", " op5", " op6", " op7",
+static const char *ns_ops[] = {
+       "", " inv_q", " stat", " op3", " notify", " update", " op6", " op7",
        " op8", " updataA", " updateD", " updateDA",
        " updateM", " updateMA", " zoneInit", " zoneRef",
 };
 
-static char *ns_resp[] = {
+static const char *ns_resp[] = {
        "", " FormErr", " ServFail", " NXDomain",
-       " NotImp", " Refused", " Resp6", " Resp7",
-       " Resp8", " Resp9", " Resp10", " Resp11",
+       " NotImp", " Refused", " YXDomain", " YXRRSet",
+       " NXRRSet", " NotAuth", " NotZone", " Resp11",
        " Resp12", " Resp13", " Resp14", " NoChange",
 };
 
 /* skip over a domain name */
 static const u_char *
-ns_nskip(register const u_char *cp, register const u_char *bp)
+ns_nskip(register const u_char *cp)
 {
        register u_char i;
 
-       if (((i = *cp++) & INDIR_MASK) == INDIR_MASK)
-               return (cp + 1);
-       if (cp >= snapend)
-               return(NULL);
-       while (i && cp < snapend) {
+       if (!TTEST2(*cp, 1))
+               return (NULL);
+       i = *cp++;
+       while (i) {
+               if ((i & INDIR_MASK) == INDIR_MASK)
+                       return (cp + 1);
                if ((i & INDIR_MASK) == EDNS0_MASK) {
                        int bitlen, bytelen;
 
                        if ((i & ~INDIR_MASK) != EDNS0_ELT_BITLABEL)
                                return(NULL); /* unknown ELT */
+                       if (!TTEST2(*cp, 1))
+                               return (NULL);
                        if ((bitlen = *cp++) == 0)
                                bitlen = 256;
                        bytelen = (bitlen + 7) / 8;
                        cp += bytelen;
                } else
                        cp += i;
-               if (cp >= snapend)
-                       return(NULL);
+               if (!TTEST2(*cp, 1))
+                       return (NULL);
                i = *cp++;
        }
        return (cp);
@@ -95,36 +84,36 @@ static const u_char *
 blabel_print(const u_char *cp)
 {
        int bitlen, slen, b;
-       int truncated = 0;
        const u_char *bitp, *lim;
        char tc;
 
-       if (cp >= snapend)
+       if (!TTEST2(*cp, 1))
                return(NULL);
        if ((bitlen = *cp) == 0)
                bitlen = 256;
        slen = (bitlen + 3) / 4;
-       if ((lim = cp + 1 + slen) > snapend) {
-               truncated = 1;
-               lim = snapend;
-       }
+       lim = cp + 1 + slen;
 
        /* print the bit string as a hex string */
        printf("\\[x");
-       for (bitp = cp + 1, b = bitlen; bitp < lim && b > 7; b -= 8, bitp++)
+       for (bitp = cp + 1, b = bitlen; bitp < lim && b > 7; b -= 8, bitp++) {
+               TCHECK(*bitp);
                printf("%02x", *bitp);
-       if (bitp == lim)
-               printf("...");
-       else if (b > 4) {
+       }
+       if (b > 4) {
+               TCHECK(*bitp);
                tc = *bitp++;
                printf("%02x", tc & (0xff << (8 - b)));
        } else if (b > 0) {
+               TCHECK(*bitp);
                tc = *bitp++;
                printf("%1x", ((tc >> 4) & 0x0f) & (0x0f << (4 - b)));
        }
        printf("/%d]", bitlen);
-
-       return(truncated ? NULL : lim);
+       return lim;
+trunc:
+       printf(".../%d]", bitlen);
+       return NULL;
 }
 
 static int
@@ -132,15 +121,16 @@ labellen(const u_char *cp)
 {
        register u_int i;
 
-       if (cp >= snapend)
+       if (!TTEST2(*cp, 1))
                return(-1);
        i = *cp;
        if ((i & INDIR_MASK) == EDNS0_MASK) {
                int bitlen, elt;
-
-               if ((elt = (i & ~INDIR_MASK)) != EDNS0_ELT_BITLABEL)
+               if ((elt = (i & ~INDIR_MASK)) != EDNS0_ELT_BITLABEL) {
+                       printf("<ELT %d>", elt);
                        return(-1);
-               if (cp + 1 >= snapend)
+               }
+               if (!TTEST2(*(cp + 1), 1))
                        return(-1);
                if ((bitlen = *(cp + 1)) == 0)
                        bitlen = 256;
@@ -149,7 +139,7 @@ labellen(const u_char *cp)
                return(i);
 }
 
-static const u_char *
+const u_char *
 ns_nprint(register const u_char *cp, register const u_char *bp)
 {
        register u_int i, l;
@@ -159,9 +149,9 @@ ns_nprint(register const u_char *cp, register const u_char *bp)
        int elt;
        int data_size = snapend - bp;
 
-       if ((l = labellen(cp)) < 0)
+       if ((l = labellen(cp)) == (u_int)-1)
                return(NULL);
-       if (cp >= snapend)
+       if (!TTEST2(*cp, 1))
                return(NULL);
        chars_processed = 1;
        if (((i = *cp++) & INDIR_MASK) != INDIR_MASK) {
@@ -176,10 +166,12 @@ ns_nprint(register const u_char *cp, register const u_char *bp)
                                        rp = cp + 1;
                                        compress = 1;
                                }
+                               if (!TTEST2(*cp, 1))
+                                       return(NULL);
                                cp = bp + (((i << 8) | *cp) & 0x3fff);
-                               if (cp >= snapend)
+                               if ((l = labellen(cp)) == (u_int)-1)
                                        return(NULL);
-                               if ((l = labellen(cp)) < 0)
+                               if (!TTEST2(*cp, 1))
                                        return(NULL);
                                i = *cp++;
                                chars_processed++;
@@ -200,7 +192,8 @@ ns_nprint(register const u_char *cp, register const u_char *bp)
                                elt = (i & ~INDIR_MASK);
                                switch(elt) {
                                case EDNS0_ELT_BITLABEL:
-                                       blabel_print(cp);
+                                       if (blabel_print(cp) == NULL)
+                                               return (NULL);
                                        break;
                                default:
                                        /* unknown ELT */
@@ -209,13 +202,15 @@ ns_nprint(register const u_char *cp, register const u_char *bp)
                                }
                        } else {
                                if (fn_printn(cp, l, snapend))
-                                       break;
+                                       return(NULL);
                        }
 
                        cp += l;
                        chars_processed += l;
                        putchar('.');
-                       if (cp >= snapend || (l = labellen(cp)) < 0)
+                       if ((l = labellen(cp)) == (u_int)-1)
+                               return(NULL);
+                       if (!TTEST2(*cp, 1))
                                return(NULL);
                        i = *cp++;
                        chars_processed++;
@@ -229,69 +224,85 @@ ns_nprint(register const u_char *cp, register const u_char *bp)
 
 /* print a <character-string> */
 static const u_char *
-ns_cprint(register const u_char *cp, register const u_char *bp)
+ns_cprint(register const u_char *cp)
 {
        register u_int i;
 
-       if (cp >= snapend)
-               return NULL;
+       if (!TTEST2(*cp, 1))
+               return (NULL);
        i = *cp++;
-       (void)fn_printn(cp, i, snapend);
+       if (fn_printn(cp, i, snapend))
+               return (NULL);
        return (cp + i);
 }
 
-struct tok ns_type2str[] = {
-       { T_A,          "A" },
-       { T_NS,         "NS" },
-       { T_MD,         "MD" },
-       { T_MF,         "MF" },
-       { T_CNAME,      "CNAME" },
-       { T_SOA,        "SOA" },
-       { T_MB,         "MB" },
-       { T_MG,         "MG" },
-       { T_MR,         "MR" },
-       { T_NULL,       "NULL" },
-       { T_WKS,        "WKS" },
-       { T_PTR,        "PTR" },
-       { T_HINFO,      "HINFO" },
-       { T_MINFO,      "MINFO" },
-       { T_MX,         "MX" },
-       { T_TXT,        "TXT" },
-       { T_RP,         "RP" },
-       { T_AFSDB,      "AFSDB" },
-       { T_X25,        "X25" },
-       { T_ISDN,       "ISDN" },
-       { T_RT,         "RT" },
-       { T_NSAP,       "NSAP" },
+/* http://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 1183 */
+       { 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" },
-       { T_SIG,        "SIG" },
-       { T_KEY,        "KEY" },
-       { T_PX,         "PX" },
-       { T_GPOS,       "GPOS" },
-       { T_AAAA,       "AAAA" },
-       { T_LOC,        "LOC" },
-       { T_NXT,        "NXT" },
-       { T_EID,        "EID" },
-       { T_NIMLOC,     "NIMLOC" },
-       { T_SRV,        "SRV" },
-       { T_ATMA,       "ATMA" },
-       { T_NAPTR,      "NAPTR" },
-       { T_A6,         "A6" },
-       { T_DNAME,      "DNAME" },
-       { T_OPT,        "OPT" },
+       { T_SIG,        "SIG" },                /* RFC 2535 */
+       { T_KEY,        "KEY" },                /* RFC 2535 */
+       { T_PX,         "PX" },                 /* RFC 2163 */
+       { T_GPOS,       "GPOS" },               /* RFC 1712 */
+       { T_AAAA,       "AAAA" },               /* RFC 1886 */
+       { T_LOC,        "LOC" },                /* RFC 1876 */
+       { T_NXT,        "NXT" },                /* RFC 2535 */
+       { T_EID,        "EID" },                /* Nimrod */
+       { T_NIMLOC,     "NIMLOC" },             /* Nimrod */
+       { T_SRV,        "SRV" },                /* RFC 2782 */
+       { T_ATMA,       "ATMA" },               /* ATM Forum */
+       { T_NAPTR,      "NAPTR" },              /* RFC 2168, RFC 2915 */
+       { T_KX,         "KX" },                 /* RFC 2230 */
+       { T_CERT,       "CERT" },               /* RFC 2538 */
+       { T_A6,         "A6" },                 /* RFC 2874 */
+       { T_DNAME,      "DNAME" },              /* RFC 2672 */
+       { T_SINK,       "SINK" },
+       { T_OPT,        "OPT" },                /* RFC 2671 */
+       { 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_SPF,        "SPF" },                /* RFC-schlitt-spf-classic-02.txt */
        { T_UINFO,      "UINFO" },
        { T_UID,        "UID" },
        { T_GID,        "GID" },
        { T_UNSPEC,     "UNSPEC" },
        { T_UNSPECA,    "UNSPECA" },
-       { T_AXFR,       "AXFR" },
-       { T_MAILB,      "MAILB" },
-       { T_MAILA,      "MAILA" },
+       { T_TKEY,       "TKEY" },               /* RFC 2930 */
+       { T_TSIG,       "TSIG" },               /* RFC 2845 */
+       { T_IXFR,       "IXFR" },               /* RFC 1995 */
+       { T_AXFR,       "AXFR" },               /* RFC 1035 */
+       { T_MAILB,      "MAILB" },              /* RFC 1035 */
+       { T_MAILA,      "MAILA" },              /* RFC 1035 */
        { T_ANY,        "ANY" },
        { 0,            NULL }
 };
 
-struct tok ns_class2str[] = {
+const struct tok ns_class2str[] = {
        { C_IN,         "IN" },         /* Not used */
        { C_CHAOS,      "CHAOS" },
        { C_HS,         "HS" },
@@ -301,24 +312,35 @@ struct tok ns_class2str[] = {
 
 /* print a query */
 static const u_char *
-ns_qprint(register const u_char *cp, register const u_char *bp)
+ns_qprint(register const u_char *cp, register const u_char *bp, int is_mdns)
 {
        register const u_char *np = cp;
-       register u_int i;
+       register u_int i, class;
 
-       cp = ns_nskip(cp, bp);
+       cp = ns_nskip(cp);
 
-       if (cp + 4 > snapend || cp == NULL)
+       if (cp == NULL || !TTEST2(*cp, 4))
                return(NULL);
 
-       /* print the qtype and qclass (if it's not IN) */
-       i = *cp++ << 8;
-       i |= *cp++;
+       /* print the qtype */
+       i = EXTRACT_16BITS(cp);
+       cp += 2;
        printf(" %s", tok2str(ns_type2str, "Type%d", i));
-       i = *cp++ << 8;
-       i |= *cp++;
-       if (i != C_IN)
-               printf(" %s", tok2str(ns_class2str, "(Class %d)", i));
+       /* print the qclass (if it's not IN) */
+       i = EXTRACT_16BITS(cp);
+       cp += 2;
+       if (is_mdns)
+               class = (i & ~C_QU);
+       else
+               class = i;
+       if (class != C_IN)
+               printf(" %s", tok2str(ns_class2str, "(Class %d)", class));
+       if (is_mdns) {
+               if (i & C_QU)
+                       printf(" (QU)");
+               else
+                       printf(" (QM)");
+       }
 
        fputs("? ", stdout);
        cp = ns_nprint(np, bp);
@@ -327,9 +349,9 @@ ns_qprint(register const u_char *cp, register const u_char *bp)
 
 /* print a reply */
 static const u_char *
-ns_rprint(register const u_char *cp, register const u_char *bp)
+ns_rprint(register const u_char *cp, register const u_char *bp, int is_mdns)
 {
-       register u_int class;
+       register u_int i, class, opt_flags = 0;
        register u_short typ, len;
        register const u_char *rp;
 
@@ -338,24 +360,47 @@ ns_rprint(register const u_char *cp, register const u_char *bp)
                if ((cp = ns_nprint(cp, bp)) == NULL)
                        return NULL;
        } else
-               cp = ns_nskip(cp, bp);
+               cp = ns_nskip(cp);
 
-       if (cp + 10 > snapend || cp == NULL)
+       if (cp == NULL || !TTEST2(*cp, 10))
                return (snapend);
 
-       /* print the type/qtype and class (if it's not IN) */
-       typ = *cp++ << 8;
-       typ |= *cp++;
-       class = *cp++ << 8;
-       class |= *cp++;
+       /* print the type/qtype */
+       typ = EXTRACT_16BITS(cp);
+       cp += 2;
+       /* print the class (if it's not IN and the type isn't OPT) */
+       i = EXTRACT_16BITS(cp);
+       cp += 2;
+       if (is_mdns)
+               class = (i & ~C_CACHE_FLUSH);
+       else
+               class = i;
        if (class != C_IN && typ != T_OPT)
                printf(" %s", tok2str(ns_class2str, "(Class %d)", class));
+       if (is_mdns) {
+               if (i & C_CACHE_FLUSH)
+                       printf(" (Cache flush)");
+       }
 
-       /* ignore ttl */
-       cp += 4;
+       if (typ == T_OPT) {
+               /* get opt flags */
+               cp += 2;
+               opt_flags = EXTRACT_16BITS(cp);
+               /* ignore rest of ttl field */
+               cp += 2;
+       } else if (vflag > 2) {
+               /* print ttl */
+               printf(" [");
+               relts_print(EXTRACT_32BITS(cp));
+               printf("]");
+               cp += 4;
+       } else {
+               /* ignore ttl */
+               cp += 4;
+       }
 
-       len = *cp++ << 8;
-       len |= *cp++;
+       len = EXTRACT_16BITS(cp);
+       cp += 2;
 
        rp = cp + len;
 
@@ -365,9 +410,9 @@ ns_rprint(register const u_char *cp, register const u_char *bp)
 
        switch (typ) {
        case T_A:
-               if (cp + sizeof(struct in_addr) > snapend)
+               if (!TTEST2(*cp, sizeof(struct in_addr)))
                        return(NULL);
-               printf(" %s", ipaddr_string(cp));
+               printf(" %s", intoa(htonl(EXTRACT_32BITS(cp))));
                break;
 
        case T_NS:
@@ -390,7 +435,7 @@ ns_rprint(register const u_char *cp, register const u_char *bp)
                putchar(' ');
                if ((cp = ns_nprint(cp, bp)) == NULL)
                        return(NULL);
-               if (cp + 5 * 4 > snapend)
+               if (!TTEST2(*cp, 5 * 4))
                        return(NULL);
                printf(" %u", EXTRACT_32BITS(cp));
                cp += 4;
@@ -405,7 +450,7 @@ ns_rprint(register const u_char *cp, register const u_char *bp)
                break;
        case T_MX:
                putchar(' ');
-               if (cp + 2 > snapend)
+               if (!TTEST2(*cp, 2))
                        return(NULL);
                if (ns_nprint(cp + 2, bp) == NULL)
                        return(NULL);
@@ -413,31 +458,60 @@ ns_rprint(register const u_char *cp, register const u_char *bp)
                break;
 
        case T_TXT:
+               while (cp < rp) {
+                       printf(" \"");
+                       cp = ns_cprint(cp);
+                       if (cp == NULL)
+                               return(NULL);
+                       putchar('"');
+               }
+               break;
+
+       case T_SRV:
                putchar(' ');
-               (void)ns_cprint(cp, bp);
+               if (!TTEST2(*cp, 6))
+                       return(NULL);
+               if (ns_nprint(cp + 6, bp) == NULL)
+                       return(NULL);
+               printf(":%d %d %d", EXTRACT_16BITS(cp + 4),
+                       EXTRACT_16BITS(cp), EXTRACT_16BITS(cp + 2));
                break;
 
 #ifdef INET6
        case T_AAAA:
-               if (cp + sizeof(struct in6_addr) > snapend)
+           {
+               struct in6_addr addr;
+               char ntop_buf[INET6_ADDRSTRLEN];
+
+               if (!TTEST2(*cp, sizeof(struct in6_addr)))
                        return(NULL);
-               printf(" %s", ip6addr_string(cp));
+               memcpy(&addr, cp, sizeof(struct in6_addr));
+               printf(" %s",
+                   inet_ntop(AF_INET6, &addr, ntop_buf, sizeof(ntop_buf)));
+
                break;
+           }
 
        case T_A6:
            {
                struct in6_addr a;
                int pbit, pbyte;
+               char ntop_buf[INET6_ADDRSTRLEN];
 
+               if (!TTEST2(*cp, 1))
+                       return(NULL);
                pbit = *cp;
                pbyte = (pbit & ~7) / 8;
                if (pbit > 128) {
                        printf(" %u(bad plen)", pbit);
                        break;
                } else if (pbit < 128) {
+                       if (!TTEST2(*(cp + 1), sizeof(a) - pbyte))
+                               return(NULL);
                        memset(&a, 0, sizeof(a));
                        memcpy(&a.s6_addr[pbyte], cp + 1, sizeof(a) - pbyte);
-                       printf(" %u %s", pbit, ip6addr_string(&a));
+                       printf(" %u %s", pbit,
+                           inet_ntop(AF_INET6, &a, ntop_buf, sizeof(ntop_buf)));
                }
                if (pbit > 0) {
                        putchar(' ');
@@ -450,68 +524,103 @@ ns_rprint(register const u_char *cp, register const u_char *bp)
 
        case T_OPT:
                printf(" UDPsize=%u", class);
+               if (opt_flags & 0x8000)
+                       printf(" OK");
                break;
 
        case T_UNSPECA:         /* One long string */
-               if (cp + len > snapend)
+               if (!TTEST2(*cp, len))
+                       return(NULL);
+               if (fn_printn(cp, len, snapend))
                        return(NULL);
-               fn_printn(cp, len, snapend);
                break;
+
+       case T_TSIG:
+           {
+               if (cp + len > snapend)
+                       return(NULL);
+               if (!vflag)
+                       break;
+               putchar(' ');
+               if ((cp = ns_nprint(cp, bp)) == NULL)
+                       return(NULL);
+               cp += 6;
+               if (!TTEST2(*cp, 2))
+                       return(NULL);
+               printf(" fudge=%u", EXTRACT_16BITS(cp));
+               cp += 2;
+               if (!TTEST2(*cp, 2))
+                       return(NULL);
+               printf(" maclen=%u", EXTRACT_16BITS(cp));
+               cp += 2 + EXTRACT_16BITS(cp);
+               if (!TTEST2(*cp, 2))
+                       return(NULL);
+               printf(" origid=%u", EXTRACT_16BITS(cp));
+               cp += 2;
+               if (!TTEST2(*cp, 2))
+                       return(NULL);
+               printf(" error=%u", EXTRACT_16BITS(cp));
+               cp += 2;
+               if (!TTEST2(*cp, 2))
+                       return(NULL);
+               printf(" otherlen=%u", EXTRACT_16BITS(cp));
+               cp += 2;
+           }
        }
        return (rp);            /* XXX This isn't always right */
 }
 
 void
-ns_print(register const u_char *bp, u_int length)
+ns_print(register const u_char *bp, u_int length, int is_mdns)
 {
        register const HEADER *np;
        register int qdcount, ancount, nscount, arcount;
-       register const u_char *cp = NULL;
+       register const u_char *cp;
+       u_int16_t b2;
 
        np = (const HEADER *)bp;
+       TCHECK(*np);
        /* get the byte-order right */
-       qdcount = ntohs(np->qdcount);
-       ancount = ntohs(np->ancount);
-       nscount = ntohs(np->nscount);
-       arcount = ntohs(np->arcount);
+       qdcount = EXTRACT_16BITS(&np->qdcount);
+       ancount = EXTRACT_16BITS(&np->ancount);
+       nscount = EXTRACT_16BITS(&np->nscount);
+       arcount = EXTRACT_16BITS(&np->arcount);
 
        if (DNS_QR(np)) {
                /* this is a response */
-               printf(" %d%s%s%s%s%s%s",
-                       ntohs(np->id),
+               printf("%d%s%s%s%s%s%s",
+                       EXTRACT_16BITS(&np->id),
                        ns_ops[DNS_OPCODE(np)],
                        ns_resp[DNS_RCODE(np)],
                        DNS_AA(np)? "*" : "",
                        DNS_RA(np)? "" : "-",
                        DNS_TC(np)? "|" : "",
-                       DNS_CD(np)? "%" : "");
+                       DNS_AD(np)? "$" : "");
 
                if (qdcount != 1)
                        printf(" [%dq]", qdcount);
                /* Print QUESTION section on -vv */
                cp = (const u_char *)(np + 1);
                while (qdcount--) {
-                       if (qdcount < ntohs(np->qdcount) - 1)
+                       if (qdcount < EXTRACT_16BITS(&np->qdcount) - 1)
                                putchar(',');
                        if (vflag > 1) {
                                fputs(" q:", stdout);
-                               if ((cp = ns_qprint((const u_char *)(np + 1), bp))
-                                   == NULL)
+                               if ((cp = ns_qprint(cp, bp, is_mdns)) == NULL)
                                        goto trunc;
                        } else {
-                               if ((cp = ns_nskip((const u_char *)(np + 1), bp))
-                                   == NULL)
+                               if ((cp = ns_nskip(cp)) == NULL)
                                        goto trunc;
                                cp += 4;        /* skip QTYPE and QCLASS */
                        }
                }
                printf(" %d/%d/%d", ancount, nscount, arcount);
                if (ancount--) {
-                       if ((cp = ns_rprint(cp, bp)) == NULL)
+                       if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
                                goto trunc;
                        while (cp < snapend && ancount--) {
                                putchar(',');
-                               if ((cp = ns_rprint(cp, bp)) == NULL)
+                               if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
                                        goto trunc;
                        }
                }
@@ -521,11 +630,11 @@ ns_print(register const u_char *bp, u_int length)
                if (vflag > 1) {
                        if (cp < snapend && nscount--) {
                                fputs(" ns:", stdout);
-                               if ((cp = ns_rprint(cp, bp)) == NULL)
+                               if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
                                        goto trunc;
                                while (cp < snapend && nscount--) {
                                        putchar(',');
-                                       if ((cp = ns_rprint(cp, bp)) == NULL)
+                                       if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
                                                goto trunc;
                                }
                        }
@@ -533,11 +642,11 @@ ns_print(register const u_char *bp, u_int length)
                                goto trunc;
                        if (cp < snapend && arcount--) {
                                fputs(" ar:", stdout);
-                               if ((cp = ns_rprint(cp, bp)) == NULL)
+                               if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
                                        goto trunc;
                                while (cp < snapend && arcount--) {
                                        putchar(',');
-                                       if ((cp = ns_rprint(cp, bp)) == NULL)
+                                       if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
                                                goto trunc;
                                }
                        }
@@ -547,13 +656,14 @@ ns_print(register const u_char *bp, u_int length)
        }
        else {
                /* this is a request */
-               printf(" %d%s%s%s", ntohs(np->id), ns_ops[DNS_OPCODE(np)],
+               printf("%d%s%s%s", EXTRACT_16BITS(&np->id), ns_ops[DNS_OPCODE(np)],
                    DNS_RD(np) ? "+" : "",
-                   DNS_AD(np) ? "$" : "");
+                   DNS_CD(np) ? "%" : "");
 
                /* any weirdness? */
-               if (*(((u_short *)np)+1) & htons(0x6cf))
-                       printf(" [b2&3=0x%x]", ntohs(*(((u_short *)np)+1)));
+               b2 = EXTRACT_16BITS(((u_short *)np)+1);
+               if (b2 & 0x6cf)
+                       printf(" [b2&3=0x%x]", b2);
 
                if (DNS_OPCODE(np) == IQUERY) {
                        if (qdcount)
@@ -572,14 +682,15 @@ ns_print(register const u_char *bp, u_int length)
                if (arcount)
                        printf(" [%dau]", arcount);
 
+               cp = (const u_char *)(np + 1);
                if (qdcount--) {
-                       cp = ns_qprint((const u_char *)(np + 1),
-                                      (const u_char *)np);
+                       cp = ns_qprint(cp, (const u_char *)np, is_mdns);
                        if (!cp)
                                goto trunc;
                        while (cp < snapend && qdcount--) {
                                cp = ns_qprint((const u_char *)cp,
-                                              (const u_char *)np);
+                                              (const u_char *)np,
+                                              is_mdns);
                                if (!cp)
                                        goto trunc;
                        }
@@ -590,11 +701,11 @@ ns_print(register const u_char *bp, u_int length)
                /* Print remaining sections on -vv */
                if (vflag > 1) {
                        if (ancount--) {
-                               if ((cp = ns_rprint(cp, bp)) == NULL)
+                               if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
                                        goto trunc;
                                while (cp < snapend && ancount--) {
                                        putchar(',');
-                                       if ((cp = ns_rprint(cp, bp)) == NULL)
+                                       if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
                                                goto trunc;
                                }
                        }
@@ -602,11 +713,11 @@ ns_print(register const u_char *bp, u_int length)
                                goto trunc;
                        if (cp < snapend && nscount--) {
                                fputs(" ns:", stdout);
-                               if ((cp = ns_rprint(cp, bp)) == NULL)
+                               if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
                                        goto trunc;
                                while (nscount-- && cp < snapend) {
                                        putchar(',');
-                                       if ((cp = ns_rprint(cp, bp)) == NULL)
+                                       if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
                                                goto trunc;
                                }
                        }
@@ -614,11 +725,11 @@ ns_print(register const u_char *bp, u_int length)
                                goto trunc;
                        if (cp < snapend && arcount--) {
                                fputs(" ar:", stdout);
-                               if ((cp = ns_rprint(cp, bp)) == NULL)
+                               if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
                                        goto trunc;
                                while (cp < snapend && arcount--) {
                                        putchar(',');
-                                       if ((cp = ns_rprint(cp, bp)) == NULL)
+                                       if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
                                                goto trunc;
                                }
                        }