X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/1fbb57a354465557ed6db53642d8696d029d4c08..1a04b92e365f5ed01ca38619b41bcc4fc9cbd63c:/print-domain.c

diff --git a/print-domain.c b/print-domain.c
index a6a6d3a2..787a2d66 100644
--- a/print-domain.c
+++ b/print-domain.c
@@ -19,19 +19,22 @@
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  */
 
+/* \summary: Domain Name System (DNS) printer */
+
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
-#include <tcpdump-stdinc.h>
-
-#include "nameser.h"
+#include <netdissect-stdinc.h>
 
 #include <string.h>
 
-#include "interface.h"
+#include "netdissect.h"
 #include "addrtoname.h"
-#include "extract.h"                    /* must come after interface.h */
+#include "addrtostr.h"
+#include "extract.h"
+
+#include "nameser.h"
 
 static const char *ns_ops[] = {
 	"", " inv_q", " stat", " op3", " notify", " update", " op6", " op7",
@@ -49,13 +52,14 @@ static const char *ns_resp[] = {
 /* skip over a domain name */
 static const u_char *
 ns_nskip(netdissect_options *ndo,
-         register const u_char *cp)
+         const u_char *cp)
 {
-	register u_char i;
+	u_char i;
 
-	if (!ND_TTEST2(*cp, 1))
+	if (!ND_TTEST_1(cp))
 		return (NULL);
-	i = *cp++;
+	i = EXTRACT_U_1(cp);
+	cp++;
 	while (i) {
 		if ((i & INDIR_MASK) == INDIR_MASK)
 			return (cp + 1);
@@ -64,17 +68,19 @@ ns_nskip(netdissect_options *ndo,
 
 			if ((i & ~INDIR_MASK) != EDNS0_ELT_BITLABEL)
 				return(NULL); /* unknown ELT */
-			if (!ND_TTEST2(*cp, 1))
+			if (!ND_TTEST_1(cp))
 				return (NULL);
-			if ((bitlen = *cp++) == 0)
+			if ((bitlen = EXTRACT_U_1(cp)) == 0)
 				bitlen = 256;
+			cp++;
 			bytelen = (bitlen + 7) / 8;
 			cp += bytelen;
 		} else
 			cp += i;
-		if (!ND_TTEST2(*cp, 1))
+		if (!ND_TTEST_1(cp))
 			return (NULL);
-		i = *cp++;
+		i = EXTRACT_U_1(cp);
+		cp++;
 	}
 	return (cp);
 }
@@ -88,9 +94,9 @@ blabel_print(netdissect_options *ndo,
 	const u_char *bitp, *lim;
 	char tc;
 
-	if (!ND_TTEST2(*cp, 1))
+	if (!ND_TTEST_1(cp))
 		return(NULL);
-	if ((bitlen = *cp) == 0)
+	if ((bitlen = EXTRACT_U_1(cp)) == 0)
 		bitlen = 256;
 	slen = (bitlen + 3) / 4;
 	lim = cp + 1 + slen;
@@ -98,16 +104,18 @@ blabel_print(netdissect_options *ndo,
 	/* print the bit string as a hex string */
 	ND_PRINT((ndo, "\\[x"));
 	for (bitp = cp + 1, b = bitlen; bitp < lim && b > 7; b -= 8, bitp++) {
-		ND_TCHECK(*bitp);
-		ND_PRINT((ndo, "%02x", *bitp));
+		ND_TCHECK_1(bitp);
+		ND_PRINT((ndo, "%02x", EXTRACT_U_1(bitp)));
 	}
 	if (b > 4) {
-		ND_TCHECK(*bitp);
-		tc = *bitp++;
+		ND_TCHECK_1(bitp);
+		tc = EXTRACT_U_1(bitp);
+		bitp++;
 		ND_PRINT((ndo, "%02x", tc & (0xff << (8 - b))));
 	} else if (b > 0) {
-		ND_TCHECK(*bitp);
-		tc = *bitp++;
+		ND_TCHECK_1(bitp);
+		tc = EXTRACT_U_1(bitp);
+		bitp++;
 		ND_PRINT((ndo, "%1x", ((tc >> 4) & 0x0f) & (0x0f << (4 - b))));
 	}
 	ND_PRINT((ndo, "/%d]", bitlen));
@@ -121,20 +129,20 @@ static int
 labellen(netdissect_options *ndo,
          const u_char *cp)
 {
-	register u_int i;
+	u_int i;
 
-	if (!ND_TTEST2(*cp, 1))
+	if (!ND_TTEST_1(cp))
 		return(-1);
-	i = *cp;
+	i = EXTRACT_U_1(cp);
 	if ((i & INDIR_MASK) == EDNS0_MASK) {
 		int bitlen, elt;
 		if ((elt = (i & ~INDIR_MASK)) != EDNS0_ELT_BITLABEL) {
 			ND_PRINT((ndo, "<ELT %d>", elt));
 			return(-1);
 		}
-		if (!ND_TTEST2(*(cp + 1), 1))
+		if (!ND_TTEST_1(cp + 1))
 			return(-1);
-		if ((bitlen = *(cp + 1)) == 0)
+		if ((bitlen = EXTRACT_U_1(cp + 1)) == 0)
 			bitlen = 256;
 		return(((bitlen + 7) / 8) + 1);
 	} else
@@ -143,21 +151,22 @@ labellen(netdissect_options *ndo,
 
 const u_char *
 ns_nprint(netdissect_options *ndo,
-          register const u_char *cp, register const u_char *bp)
+          const u_char *cp, const u_char *bp)
 {
-	register u_int i, l;
-	register const u_char *rp = NULL;
-	register int compress = 0;
-	int chars_processed;
+	u_int i, l;
+	const u_char *rp = NULL;
+	int compress = 0;
 	int elt;
-	int data_size = ndo->ndo_snapend - bp;
+	u_int offset, max_offset;
 
 	if ((l = labellen(ndo, cp)) == (u_int)-1)
 		return(NULL);
-	if (!ND_TTEST2(*cp, 1))
+	if (!ND_TTEST_1(cp))
 		return(NULL);
-	chars_processed = 1;
-	if (((i = *cp++) & INDIR_MASK) != INDIR_MASK) {
+	max_offset = (u_int)(cp - bp);
+	i = EXTRACT_U_1(cp);
+	cp++;
+	if ((i & INDIR_MASK) != INDIR_MASK) {
 		compress = 0;
 		rp = cp + l;
 	}
@@ -169,26 +178,31 @@ ns_nprint(netdissect_options *ndo,
 					rp = cp + 1;
 					compress = 1;
 				}
-				if (!ND_TTEST2(*cp, 1))
-					return(NULL);
-				cp = bp + (((i << 8) | *cp) & 0x3fff);
-				if ((l = labellen(ndo, cp)) == (u_int)-1)
+				if (!ND_TTEST_1(cp))
 					return(NULL);
-				if (!ND_TTEST2(*cp, 1))
-					return(NULL);
-				i = *cp++;
-				chars_processed++;
-
+				offset = (((i << 8) | EXTRACT_U_1(cp)) & 0x3fff);
 				/*
-				 * If we've looked at every character in
-				 * the message, this pointer will make
-				 * us look at some character again,
-				 * which means we're looping.
+				 * 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 (chars_processed >= data_size) {
-					ND_PRINT((ndo, "<LOOP>"));
-					return (NULL);
+				if (offset >= max_offset) {
+					ND_PRINT((ndo, "<BAD PTR>"));
+					return(NULL);
 				}
+				max_offset = offset;
+				cp = bp + offset;
+				if ((l = labellen(ndo, cp)) == (u_int)-1)
+					return(NULL);
+				if (!ND_TTEST_1(cp))
+					return(NULL);
+				i = EXTRACT_U_1(cp);
+				cp++;
 				continue;
 			}
 			if ((i & INDIR_MASK) == EDNS0_MASK) {
@@ -209,14 +223,13 @@ ns_nprint(netdissect_options *ndo,
 			}
 
 			cp += l;
-			chars_processed += l;
 			ND_PRINT((ndo, "."));
 			if ((l = labellen(ndo, cp)) == (u_int)-1)
 				return(NULL);
-			if (!ND_TTEST2(*cp, 1))
+			if (!ND_TTEST_1(cp))
 				return(NULL);
-			i = *cp++;
-			chars_processed++;
+			i = EXTRACT_U_1(cp);
+			cp++;
 			if (!compress)
 				rp += l + 1;
 		}
@@ -228,13 +241,14 @@ ns_nprint(netdissect_options *ndo,
 /* print a <character-string> */
 static const u_char *
 ns_cprint(netdissect_options *ndo,
-          register const u_char *cp)
+          const u_char *cp)
 {
-	register u_int i;
+	u_int i;
 
-	if (!ND_TTEST2(*cp, 1))
+	if (!ND_TTEST_1(cp))
 		return (NULL);
-	i = *cp++;
+	i = EXTRACT_U_1(cp);
+	cp++;
 	if (fn_printn(ndo, cp, i, ndo->ndo_snapend))
 		return (NULL);
 	return (cp + i);
@@ -317,22 +331,22 @@ const struct tok ns_class2str[] = {
 /* print a query */
 static const u_char *
 ns_qprint(netdissect_options *ndo,
-          register const u_char *cp, register const u_char *bp, int is_mdns)
+          const u_char *cp, const u_char *bp, int is_mdns)
 {
-	register const u_char *np = cp;
-	register u_int i, class;
+	const u_char *np = cp;
+	u_int i, class;
 
 	cp = ns_nskip(ndo, cp);
 
-	if (cp == NULL || !ND_TTEST2(*cp, 4))
+	if (cp == NULL || !ND_TTEST_4(cp))
 		return(NULL);
 
 	/* print the qtype */
-	i = EXTRACT_16BITS(cp);
+	i = EXTRACT_BE_U_2(cp);
 	cp += 2;
 	ND_PRINT((ndo, " %s", tok2str(ns_type2str, "Type%d", i)));
 	/* print the qclass (if it's not IN) */
-	i = EXTRACT_16BITS(cp);
+	i = EXTRACT_BE_U_2(cp);
 	cp += 2;
 	if (is_mdns)
 		class = (i & ~C_QU);
@@ -352,11 +366,11 @@ ns_qprint(netdissect_options *ndo,
 /* print a reply */
 static const u_char *
 ns_rprint(netdissect_options *ndo,
-          register const u_char *cp, register const u_char *bp, int is_mdns)
+          const u_char *cp, const u_char *bp, int is_mdns)
 {
-	register u_int i, class, opt_flags = 0;
-	register u_short typ, len;
-	register const u_char *rp;
+	u_int i, class, opt_flags = 0;
+	u_short typ, len;
+	const u_char *rp;
 
 	if (ndo->ndo_vflag) {
 		ND_PRINT((ndo, " "));
@@ -365,14 +379,14 @@ ns_rprint(netdissect_options *ndo,
 	} else
 		cp = ns_nskip(ndo, cp);
 
-	if (cp == NULL || !ND_TTEST2(*cp, 10))
+	if (cp == NULL || !ND_TTEST_LEN(cp, 10))
 		return (ndo->ndo_snapend);
 
 	/* print the type/qtype */
-	typ = EXTRACT_16BITS(cp);
+	typ = EXTRACT_BE_U_2(cp);
 	cp += 2;
 	/* print the class (if it's not IN and the type isn't OPT) */
-	i = EXTRACT_16BITS(cp);
+	i = EXTRACT_BE_U_2(cp);
 	cp += 2;
 	if (is_mdns)
 		class = (i & ~C_CACHE_FLUSH);
@@ -388,13 +402,13 @@ ns_rprint(netdissect_options *ndo,
 	if (typ == T_OPT) {
 		/* get opt flags */
 		cp += 2;
-		opt_flags = EXTRACT_16BITS(cp);
+		opt_flags = EXTRACT_BE_U_2(cp);
 		/* ignore rest of ttl field */
 		cp += 2;
 	} else if (ndo->ndo_vflag > 2) {
 		/* print ttl */
 		ND_PRINT((ndo, " ["));
-		relts_print(ndo, EXTRACT_32BITS(cp));
+		unsigned_relts_print(ndo, EXTRACT_BE_U_4(cp));
 		ND_PRINT((ndo, "]"));
 		cp += 4;
 	} else {
@@ -402,7 +416,7 @@ ns_rprint(netdissect_options *ndo,
 		cp += 4;
 	}
 
-	len = EXTRACT_16BITS(cp);
+	len = EXTRACT_BE_U_2(cp);
 	cp += 2;
 
 	rp = cp + len;
@@ -413,9 +427,9 @@ ns_rprint(netdissect_options *ndo,
 
 	switch (typ) {
 	case T_A:
-		if (!ND_TTEST2(*cp, sizeof(struct in_addr)))
+		if (!ND_TTEST_LEN(cp, sizeof(struct in_addr)))
 			return(NULL);
-		ND_PRINT((ndo, " %s", intoa(htonl(EXTRACT_32BITS(cp)))));
+		ND_PRINT((ndo, " %s", intoa(htonl(EXTRACT_BE_U_4(cp)))));
 		break;
 
 	case T_NS:
@@ -438,26 +452,26 @@ ns_rprint(netdissect_options *ndo,
 		ND_PRINT((ndo, " "));
 		if ((cp = ns_nprint(ndo, cp, bp)) == NULL)
 			return(NULL);
-		if (!ND_TTEST2(*cp, 5 * 4))
+		if (!ND_TTEST_LEN(cp, 5 * 4))
 			return(NULL);
-		ND_PRINT((ndo, " %u", EXTRACT_32BITS(cp)));
+		ND_PRINT((ndo, " %u", EXTRACT_BE_U_4(cp)));
 		cp += 4;
-		ND_PRINT((ndo, " %u", EXTRACT_32BITS(cp)));
+		ND_PRINT((ndo, " %u", EXTRACT_BE_U_4(cp)));
 		cp += 4;
-		ND_PRINT((ndo, " %u", EXTRACT_32BITS(cp)));
+		ND_PRINT((ndo, " %u", EXTRACT_BE_U_4(cp)));
 		cp += 4;
-		ND_PRINT((ndo, " %u", EXTRACT_32BITS(cp)));
+		ND_PRINT((ndo, " %u", EXTRACT_BE_U_4(cp)));
 		cp += 4;
-		ND_PRINT((ndo, " %u", EXTRACT_32BITS(cp)));
+		ND_PRINT((ndo, " %u", EXTRACT_BE_U_4(cp)));
 		cp += 4;
 		break;
 	case T_MX:
 		ND_PRINT((ndo, " "));
-		if (!ND_TTEST2(*cp, 2))
+		if (!ND_TTEST_2(cp))
 			return(NULL);
 		if (ns_nprint(ndo, cp + 2, bp) == NULL)
 			return(NULL);
-		ND_PRINT((ndo, " %d", EXTRACT_16BITS(cp)));
+		ND_PRINT((ndo, " %d", EXTRACT_BE_U_2(cp)));
 		break;
 
 	case T_TXT:
@@ -472,25 +486,22 @@ ns_rprint(netdissect_options *ndo,
 
 	case T_SRV:
 		ND_PRINT((ndo, " "));
-		if (!ND_TTEST2(*cp, 6))
+		if (!ND_TTEST_6(cp))
 			return(NULL);
 		if (ns_nprint(ndo, cp + 6, bp) == NULL)
 			return(NULL);
-		ND_PRINT((ndo, ":%d %d %d", EXTRACT_16BITS(cp + 4),
-			EXTRACT_16BITS(cp), EXTRACT_16BITS(cp + 2)));
+		ND_PRINT((ndo, ":%d %d %d", EXTRACT_BE_U_2(cp + 4),
+			  EXTRACT_BE_U_2(cp), EXTRACT_BE_U_2(cp + 2)));
 		break;
 
-#ifdef INET6
 	case T_AAAA:
 	    {
-		struct in6_addr addr;
 		char ntop_buf[INET6_ADDRSTRLEN];
 
-		if (!ND_TTEST2(*cp, sizeof(struct in6_addr)))
+		if (!ND_TTEST_LEN(cp, sizeof(struct in6_addr)))
 			return(NULL);
-		memcpy(&addr, cp, sizeof(struct in6_addr));
 		ND_PRINT((ndo, " %s",
-		    inet_ntop(AF_INET6, &addr, ntop_buf, sizeof(ntop_buf))));
+		    addrtostr6(cp, ntop_buf, sizeof(ntop_buf))));
 
 		break;
 	    }
@@ -501,20 +512,20 @@ ns_rprint(netdissect_options *ndo,
 		int pbit, pbyte;
 		char ntop_buf[INET6_ADDRSTRLEN];
 
-		if (!ND_TTEST2(*cp, 1))
+		if (!ND_TTEST_1(cp))
 			return(NULL);
-		pbit = *cp;
+		pbit = EXTRACT_U_1(cp);
 		pbyte = (pbit & ~7) / 8;
 		if (pbit > 128) {
 			ND_PRINT((ndo, " %u(bad plen)", pbit));
 			break;
 		} else if (pbit < 128) {
-			if (!ND_TTEST2(*(cp + 1), sizeof(a) - pbyte))
+			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);
 			ND_PRINT((ndo, " %u %s", pbit,
-			    inet_ntop(AF_INET6, &a, ntop_buf, sizeof(ntop_buf))));
+			    addrtostr6(&a, ntop_buf, sizeof(ntop_buf))));
 		}
 		if (pbit > 0) {
 			ND_PRINT((ndo, " "));
@@ -523,7 +534,6 @@ ns_rprint(netdissect_options *ndo,
 		}
 		break;
 	    }
-#endif /*INET6*/
 
 	case T_OPT:
 		ND_PRINT((ndo, " UDPsize=%u", class));
@@ -532,7 +542,7 @@ ns_rprint(netdissect_options *ndo,
 		break;
 
 	case T_UNSPECA:		/* One long string */
-		if (!ND_TTEST2(*cp, len))
+		if (!ND_TTEST_LEN(cp, len))
 			return(NULL);
 		if (fn_printn(ndo, cp, len, ndo->ndo_snapend))
 			return(NULL);
@@ -548,25 +558,25 @@ ns_rprint(netdissect_options *ndo,
 		if ((cp = ns_nprint(ndo, cp, bp)) == NULL)
 			return(NULL);
 		cp += 6;
-		if (!ND_TTEST2(*cp, 2))
+		if (!ND_TTEST_2(cp))
 			return(NULL);
-		ND_PRINT((ndo, " fudge=%u", EXTRACT_16BITS(cp)));
+		ND_PRINT((ndo, " fudge=%u", EXTRACT_BE_U_2(cp)));
 		cp += 2;
-		if (!ND_TTEST2(*cp, 2))
+		if (!ND_TTEST_2(cp))
 			return(NULL);
-		ND_PRINT((ndo, " maclen=%u", EXTRACT_16BITS(cp)));
-		cp += 2 + EXTRACT_16BITS(cp);
-		if (!ND_TTEST2(*cp, 2))
+		ND_PRINT((ndo, " maclen=%u", EXTRACT_BE_U_2(cp)));
+		cp += 2 + EXTRACT_BE_U_2(cp);
+		if (!ND_TTEST_2(cp))
 			return(NULL);
-		ND_PRINT((ndo, " origid=%u", EXTRACT_16BITS(cp)));
+		ND_PRINT((ndo, " origid=%u", EXTRACT_BE_U_2(cp)));
 		cp += 2;
-		if (!ND_TTEST2(*cp, 2))
+		if (!ND_TTEST_2(cp))
 			return(NULL);
-		ND_PRINT((ndo, " error=%u", EXTRACT_16BITS(cp)));
+		ND_PRINT((ndo, " error=%u", EXTRACT_BE_U_2(cp)));
 		cp += 2;
-		if (!ND_TTEST2(*cp, 2))
+		if (!ND_TTEST_2(cp))
 			return(NULL);
-		ND_PRINT((ndo, " otherlen=%u", EXTRACT_16BITS(cp)));
+		ND_PRINT((ndo, " otherlen=%u", EXTRACT_BE_U_2(cp)));
 		cp += 2;
 	    }
 	}
@@ -574,39 +584,42 @@ ns_rprint(netdissect_options *ndo,
 }
 
 void
-ns_print(netdissect_options *ndo,
-         register const u_char *bp, u_int length, int is_mdns)
+domain_print(netdissect_options *ndo,
+         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;
+	const HEADER *np;
+	uint16_t flags;
+	u_int qdcount, ancount, nscount, arcount;
+	u_int i;
+	const u_char *cp;
 	uint16_t b2;
 
 	np = (const HEADER *)bp;
 	ND_TCHECK(*np);
+	flags = EXTRACT_BE_U_2(np->flags);
 	/* get the byte-order right */
-	qdcount = EXTRACT_16BITS(&np->qdcount);
-	ancount = EXTRACT_16BITS(&np->ancount);
-	nscount = EXTRACT_16BITS(&np->nscount);
-	arcount = EXTRACT_16BITS(&np->arcount);
+	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);
 
-	if (DNS_QR(np)) {
+	if (DNS_QR(flags)) {
 		/* this is a response */
 		ND_PRINT((ndo, "%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_AD(np)? "$" : ""));
+			EXTRACT_BE_U_2(np->id),
+			ns_ops[DNS_OPCODE(flags)],
+			ns_resp[DNS_RCODE(flags)],
+			DNS_AA(flags)? "*" : "",
+			DNS_RA(flags)? "" : "-",
+			DNS_TC(flags)? "|" : "",
+			DNS_AD(flags)? "$" : ""));
 
 		if (qdcount != 1)
-			ND_PRINT((ndo, " [%dq]", qdcount));
+			ND_PRINT((ndo, " [%uq]", qdcount));
 		/* Print QUESTION section on -vv */
 		cp = (const u_char *)(np + 1);
-		while (qdcount--) {
-			if (qdcount < EXTRACT_16BITS(&np->qdcount) - 1)
+		for (i = 0; i < qdcount; i++) {
+			if (i != 0)
 				ND_PRINT((ndo, ","));
 			if (ndo->ndo_vflag > 1) {
 				ND_PRINT((ndo, " q:"));
@@ -618,126 +631,140 @@ ns_print(netdissect_options *ndo,
 				cp += 4;	/* skip QTYPE and QCLASS */
 			}
 		}
-		ND_PRINT((ndo, " %d/%d/%d", ancount, nscount, arcount));
-		if (ancount--) {
+		ND_PRINT((ndo, " %u/%u/%u", ancount, nscount, arcount));
+		if (ancount) {
 			if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
 				goto trunc;
-			while (cp < ndo->ndo_snapend && ancount--) {
+			ancount--;
+			while (cp < ndo->ndo_snapend && ancount) {
 				ND_PRINT((ndo, ","));
 				if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
 					goto trunc;
+				ancount--;
 			}
 		}
-		if (ancount > 0)
+		if (ancount)
 			goto trunc;
 		/* Print NS and AR sections on -vv */
 		if (ndo->ndo_vflag > 1) {
-			if (cp < ndo->ndo_snapend && nscount--) {
+			if (cp < ndo->ndo_snapend && nscount) {
 				ND_PRINT((ndo, " ns:"));
 				if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
 					goto trunc;
-				while (cp < ndo->ndo_snapend && nscount--) {
+				nscount--;
+				while (cp < ndo->ndo_snapend && nscount) {
 					ND_PRINT((ndo, ","));
 					if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
 						goto trunc;
+					nscount--;
 				}
 			}
-			if (nscount > 0)
+			if (nscount)
 				goto trunc;
-			if (cp < ndo->ndo_snapend && arcount--) {
+			if (cp < ndo->ndo_snapend && arcount) {
 				ND_PRINT((ndo, " ar:"));
 				if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
 					goto trunc;
-				while (cp < ndo->ndo_snapend && arcount--) {
+				arcount--;
+				while (cp < ndo->ndo_snapend && arcount) {
 					ND_PRINT((ndo, ","));
 					if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
 						goto trunc;
+					arcount--;
 				}
 			}
-			if (arcount > 0)
+			if (arcount)
 				goto trunc;
 		}
 	}
 	else {
 		/* this is a request */
-		ND_PRINT((ndo, "%d%s%s%s", EXTRACT_16BITS(&np->id), ns_ops[DNS_OPCODE(np)],
-		    DNS_RD(np) ? "+" : "",
-		    DNS_CD(np) ? "%" : ""));
+		ND_PRINT((ndo, "%d%s%s%s", EXTRACT_BE_U_2(np->id), ns_ops[DNS_OPCODE(flags)],
+			  DNS_RD(flags) ? "+" : "",
+			  DNS_CD(flags) ? "%" : ""));
 
 		/* any weirdness? */
-		b2 = EXTRACT_16BITS(((const u_short *)np)+1);
+		b2 = EXTRACT_BE_U_2(((const u_short *)np) + 1);
 		if (b2 & 0x6cf)
 			ND_PRINT((ndo, " [b2&3=0x%x]", b2));
 
-		if (DNS_OPCODE(np) == IQUERY) {
+		if (DNS_OPCODE(flags) == IQUERY) {
 			if (qdcount)
-				ND_PRINT((ndo, " [%dq]", qdcount));
+				ND_PRINT((ndo, " [%uq]", qdcount));
 			if (ancount != 1)
-				ND_PRINT((ndo, " [%da]", ancount));
+				ND_PRINT((ndo, " [%ua]", ancount));
 		}
 		else {
 			if (ancount)
-				ND_PRINT((ndo, " [%da]", ancount));
+				ND_PRINT((ndo, " [%ua]", ancount));
 			if (qdcount != 1)
-				ND_PRINT((ndo, " [%dq]", qdcount));
+				ND_PRINT((ndo, " [%uq]", qdcount));
 		}
 		if (nscount)
-			ND_PRINT((ndo, " [%dn]", nscount));
+			ND_PRINT((ndo, " [%un]", nscount));
 		if (arcount)
-			ND_PRINT((ndo, " [%dau]", arcount));
+			ND_PRINT((ndo, " [%uau]", arcount));
 
 		cp = (const u_char *)(np + 1);
-		if (qdcount--) {
+		if (qdcount) {
 			cp = ns_qprint(ndo, cp, (const u_char *)np, is_mdns);
 			if (!cp)
 				goto trunc;
-			while (cp < ndo->ndo_snapend && qdcount--) {
+			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 > 0)
+		if (qdcount)
 			goto trunc;
 
 		/* Print remaining sections on -vv */
 		if (ndo->ndo_vflag > 1) {
-			if (ancount--) {
+			if (ancount) {
 				if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
 					goto trunc;
-				while (cp < ndo->ndo_snapend && ancount--) {
+				ancount--;
+				while (cp < ndo->ndo_snapend && ancount) {
 					ND_PRINT((ndo, ","));
 					if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
 						goto trunc;
+					ancount--;
 				}
 			}
-			if (ancount > 0)
+			if (ancount)
 				goto trunc;
-			if (cp < ndo->ndo_snapend && nscount--) {
+			if (cp < ndo->ndo_snapend && nscount) {
 				ND_PRINT((ndo, " ns:"));
 				if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
 					goto trunc;
-				while (nscount-- && cp < ndo->ndo_snapend) {
+				nscount--;
+				while (cp < ndo->ndo_snapend && nscount) {
 					ND_PRINT((ndo, ","));
 					if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
 						goto trunc;
+					nscount--;
 				}
 			}
 			if (nscount > 0)
 				goto trunc;
-			if (cp < ndo->ndo_snapend && arcount--) {
+			if (cp < ndo->ndo_snapend && arcount) {
 				ND_PRINT((ndo, " ar:"));
 				if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
 					goto trunc;
-				while (cp < ndo->ndo_snapend && arcount--) {
+				arcount--;
+				while (cp < ndo->ndo_snapend && arcount) {
 					ND_PRINT((ndo, ","));
 					if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
 						goto trunc;
+					arcount--;
 				}
 			}
-			if (arcount > 0)
+			if (arcount)
 				goto trunc;
 		}
 	}