]> The Tcpdump Group git mirrors - tcpdump/blobdiff - print-ip.c
Revert partially the commit 21b1273
[tcpdump] / print-ip.c
index d56c0bd8c076cf943c9710f7159320175438304a..8dab94437e6919924dc23b1ac3c8de30375bd634 100644 (file)
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  */
 
-#ifndef lint
-static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-ip.c,v 1.137 2004-04-26 18:27:57 hannes Exp $ (LBL)";
-#endif
+/* \summary: IP printer */
 
 #ifdef HAVE_CONFIG_H
-#include "config.h"
+#include <config.h>
 #endif
 
-#include <tcpdump-stdinc.h>
+#include "netdissect-stdinc.h"
 
-#include <stdio.h>
-#include <stdlib.h>
 #include <string.h>
 
+#include "netdissect.h"
 #include "addrtoname.h"
-#include "interface.h"
-#include "extract.h"                   /* must come after interface.h */
+#include "extract.h"
 
 #include "ip.h"
 #include "ipproto.h"
 
+
+static const struct tok ip_option_values[] = {
+    { IPOPT_EOL, "EOL" },
+    { IPOPT_NOP, "NOP" },
+    { IPOPT_TS, "timestamp" },
+    { IPOPT_SECURITY, "security" },
+    { IPOPT_RR, "RR" },
+    { IPOPT_SSRR, "SSRR" },
+    { IPOPT_LSRR, "LSRR" },
+    { IPOPT_RA, "RA" },
+    { IPOPT_RFC1393, "traceroute" },
+    { 0, NULL }
+};
+
 /*
  * print the recorded route in an IP RR, LSRR or SSRR option.
  */
-static void
-ip_printroute(const char *type, register const u_char *cp, u_int length)
+static int
+ip_printroute(netdissect_options *ndo,
+              const u_char *cp, u_int length)
 {
-       register u_int ptr;
-       register u_int len;
+       u_int ptr;
+       u_int len;
 
        if (length < 3) {
-               printf(" [bad length %u]", length);
-               return;
+               ND_PRINT(" [bad length %u]", length);
+               return (0);
        }
-       printf(" %s{", type);
        if ((length + 1) & 3)
-               printf(" [bad length %u]", length);
-       ptr = cp[2] - 1;
+               ND_PRINT(" [bad length %u]", length);
+       ptr = GET_U_1(cp + 2) - 1;
        if (ptr < 3 || ((ptr + 1) & 3) || ptr > length + 1)
-               printf(" [bad ptr %u]", cp[2]);
+               ND_PRINT(" [bad ptr %u]", GET_U_1(cp + 2));
 
-       type = "";
        for (len = 3; len < length; len += 4) {
-               if (ptr == len)
-                       type = "#";
-               printf("%s%s", type, ipaddr_string(&cp[len]));
-               type = " ";
+               ND_PRINT(" %s", GET_IPADDR_STRING(cp + len));
+               if (ptr > len)
+                       ND_PRINT(",");
        }
-       printf("%s}", ptr == len? "#" : "");
+       return (0);
 }
 
 /*
- * If source-routing is present, return the final destination.
+ * If source-routing is present and valid, return the final destination.
  * Otherwise, return IP destination.
  *
  * This is used for UDP and TCP pseudo-header in the checksum
  * calculation.
  */
-u_int32_t
-ip_finddst(const struct ip *ip)
+static uint32_t
+ip_finddst(netdissect_options *ndo,
+           const struct ip *ip)
 {
-       int length;
-       int len;
+       u_int length;
+       u_int len;
        const u_char *cp;
-       u_int32_t retval;
 
        cp = (const u_char *)(ip + 1);
-       length = (IP_HL(ip) << 2) - sizeof(struct ip);
+       length = IP_HL(ip) * 4;
+       if (length < sizeof(struct ip))
+               goto trunc;
+       length -= sizeof(struct ip);
 
-       for (; length > 0; cp += len, length -= len) {
+       for (; length != 0; cp += len, length -= len) {
                int tt;
 
-               TCHECK(*cp);
-               tt = *cp;
-               if (tt == IPOPT_NOP || tt == IPOPT_EOL)
+               tt = GET_U_1(cp);
+               if (tt == IPOPT_EOL)
+                       break;
+               else if (tt == IPOPT_NOP)
                        len = 1;
                else {
-                       TCHECK(cp[1]);
-                       len = cp[1];
-               }
-               if (len < 2) {
-                       return 0;
+                       len = GET_U_1(cp + 1);
+                       if (len < 2)
+                               break;
                }
-               TCHECK2(*cp, len);
+               if (length < len)
+                       goto trunc;
+               ND_TCHECK_LEN(cp, len);
                switch (tt) {
 
                case IPOPT_SSRR:
                case IPOPT_LSRR:
                        if (len < 7)
-                               return 0;
-                       memcpy(&retval, cp + len - 4, 4);
-                       return retval;
+                               break;
+                       return (GET_IPV4_TO_NETWORK_ORDER(cp + len - 4));
                }
        }
-       return ip->ip_dst.s_addr;
-
 trunc:
-       return 0;
+       return (GET_IPV4_TO_NETWORK_ORDER(ip->ip_dst));
+}
+
+/*
+ * Compute a V4-style checksum by building a pseudoheader.
+ */
+uint16_t
+nextproto4_cksum(netdissect_options *ndo,
+                 const struct ip *ip, const uint8_t *data,
+                 u_int len, u_int covlen, uint8_t next_proto)
+{
+       struct phdr {
+               uint32_t src;
+               uint32_t dst;
+               uint8_t mbz;
+               uint8_t proto;
+               uint16_t len;
+       } ph;
+       struct cksum_vec vec[2];
+
+       /* pseudo-header.. */
+       ph.len = htons((uint16_t)len);
+       ph.mbz = 0;
+       ph.proto = next_proto;
+       ph.src = GET_IPV4_TO_NETWORK_ORDER(ip->ip_src);
+       if (IP_HL(ip) == 5)
+               ph.dst = GET_IPV4_TO_NETWORK_ORDER(ip->ip_dst);
+       else
+               ph.dst = ip_finddst(ndo, ip);
+
+       vec[0].ptr = (const uint8_t *)(void *)&ph;
+       vec[0].len = sizeof(ph);
+       vec[1].ptr = data;
+       vec[1].len = covlen;
+       return (in_cksum(vec, 2));
 }
 
-static void
-ip_printts(register const u_char *cp, u_int length)
+static int
+ip_printts(netdissect_options *ndo,
+           const u_char *cp, u_int length)
 {
-       register u_int ptr;
-       register u_int len;
-       int hoplen;
+       u_int ptr;
+       u_int len;
+       u_int hoplen;
        const char *type;
 
        if (length < 4) {
-               printf("[bad length %d]", length);
-               return;
+               ND_PRINT("[bad length %u]", length);
+               return (0);
        }
-       printf(" TS{");
-       hoplen = ((cp[3]&0xF) != IPOPT_TS_TSONLY) ? 8 : 4;
+       ND_PRINT(" TS{");
+       hoplen = ((GET_U_1(cp + 3) & 0xF) != IPOPT_TS_TSONLY) ? 8 : 4;
        if ((length - 4) & (hoplen-1))
-               printf("[bad length %d]", length);
-       ptr = cp[2] - 1;
+               ND_PRINT("[bad length %u]", length);
+       ptr = GET_U_1(cp + 2) - 1;
        len = 0;
        if (ptr < 4 || ((ptr - 4) & (hoplen-1)) || ptr > length + 1)
-               printf("[bad ptr %d]", cp[2]);
-       switch (cp[3]&0xF) {
+               ND_PRINT("[bad ptr %u]", GET_U_1(cp + 2));
+       switch (GET_U_1(cp + 3)&0xF) {
        case IPOPT_TS_TSONLY:
-               printf("TSONLY");
+               ND_PRINT("TSONLY");
                break;
        case IPOPT_TS_TSANDADDR:
-               printf("TS+ADDR");
+               ND_PRINT("TS+ADDR");
                break;
        /*
         * prespecified should really be 3, but some ones might send 2
@@ -154,13 +197,13 @@ ip_printts(register const u_char *cp, u_int length)
         */
 
        case 2:
-               printf("PRESPEC2.0");
+               ND_PRINT("PRESPEC2.0");
                break;
        case 3:                 /* IPOPT_TS_PRESPEC */
-               printf("PRESPEC");
+               ND_PRINT("PRESPEC");
                break;
        default:
-               printf("[bad ts type %d]", cp[3]&0xF);
+               ND_PRINT("[bad ts type %u]", GET_U_1(cp + 3)&0xF);
                goto done;
        }
 
@@ -168,493 +211,323 @@ ip_printts(register const u_char *cp, u_int length)
        for (len = 4; len < length; len += hoplen) {
                if (ptr == len)
                        type = " ^ ";
-               printf("%s%d@%s", type, EXTRACT_32BITS(&cp[len+hoplen-4]),
-                      hoplen!=8 ? "" : ipaddr_string(&cp[len]));
+               ND_TCHECK_LEN(cp + len, hoplen);
+               ND_PRINT("%s%u@%s", type, GET_BE_U_4(cp + len + hoplen - 4),
+                         hoplen!=8 ? "" : GET_IPADDR_STRING(cp + len));
                type = " ";
        }
 
 done:
-       printf("%s", ptr == len ? " ^ " : "");
+       ND_PRINT("%s", ptr == len ? " ^ " : "");
 
-       if (cp[3]>>4)
-               printf(" [%d hops not recorded]} ", cp[3]>>4);
+       if (GET_U_1(cp + 3) >> 4)
+               ND_PRINT(" [%u hops not recorded]} ", GET_U_1(cp + 3)>>4);
        else
-               printf("}");
+               ND_PRINT("}");
+       return (0);
+
+trunc:
+       return (-1);
 }
 
 /*
  * print IP options.
+   If truncated return -1, else 0.
  */
-static void
-ip_optprint(register const u_char *cp, u_int length)
+static int
+ip_optprint(netdissect_options *ndo,
+            const u_char *cp, u_int length)
 {
-       register u_int len;
+       u_int option_len;
+       const char *sep = "";
 
-       for (; length > 0; cp += len, length -= len) {
-               int tt;
+       for (; length > 0; cp += option_len, length -= option_len) {
+               u_int option_code;
+
+               ND_PRINT("%s", sep);
+               sep = ",";
+
+               option_code = GET_U_1(cp);
+
+               ND_PRINT("%s",
+                         tok2str(ip_option_values,"unknown %u",option_code));
+
+               if (option_code == IPOPT_NOP ||
+                    option_code == IPOPT_EOL)
+                       option_len = 1;
 
-               TCHECK(*cp);
-               tt = *cp;
-               if (tt == IPOPT_NOP || tt == IPOPT_EOL)
-                       len = 1;
                else {
-                       TCHECK(cp[1]);
-                       len = cp[1];
-                       if (len < 2) {
-                               printf("[|ip op len %d]", len);
-                               return;
+                       option_len = GET_U_1(cp + 1);
+                       if (option_len < 2) {
+                               ND_PRINT(" [bad length %u]", option_len);
+                               return 0;
                        }
-                       TCHECK2(*cp, len);
                }
-               switch (tt) {
 
-               case IPOPT_EOL:
-                       printf(" EOL");
-                       if (length > 1)
-                               printf("-%d", length - 1);
-                       return;
-
-               case IPOPT_NOP:
-                       printf(" NOP");
-                       break;
+               if (option_len > length) {
+                       ND_PRINT(" [bad length %u]", option_len);
+                       return 0;
+               }
 
-               case IPOPT_TS:
-                       ip_printts(cp, len);
-                       break;
+               ND_TCHECK_LEN(cp, option_len);
 
-#ifndef IPOPT_SECURITY
-#define IPOPT_SECURITY 130
-#endif /* IPOPT_SECURITY */
-               case IPOPT_SECURITY:
-                       printf(" SECURITY{%d}", len);
-                       break;
+               switch (option_code) {
+               case IPOPT_EOL:
+                       return 0;
 
-               case IPOPT_RR:
-                       ip_printroute("RR", cp, len);
+               case IPOPT_TS:
+                       if (ip_printts(ndo, cp, option_len) == -1)
+                               goto trunc;
                        break;
 
+               case IPOPT_RR:       /* fall through */
                case IPOPT_SSRR:
-                       ip_printroute("SSRR", cp, len);
-                       break;
-
                case IPOPT_LSRR:
-                       ip_printroute("LSRR", cp, len);
+                       if (ip_printroute(ndo, cp, option_len) == -1)
+                               goto trunc;
                        break;
 
-#ifndef IPOPT_RA
-#define IPOPT_RA 148           /* router alert */
-#endif
                case IPOPT_RA:
-                       printf(" RA");
-                       if (len != 4)
-                               printf("{%d}", len);
-                       else {
-                               TCHECK(cp[3]);
-                               if (cp[2] || cp[3])
-                                       printf("%d.%d", cp[2], cp[3]);
+                       if (option_len < 4) {
+                               ND_PRINT(" [bad length %u]", option_len);
+                               break;
                        }
+                       ND_TCHECK_1(cp + 3);
+                       if (GET_BE_U_2(cp + 2) != 0)
+                               ND_PRINT(" value %u", GET_BE_U_2(cp + 2));
                        break;
 
+               case IPOPT_NOP:       /* nothing to print - fall through */
+               case IPOPT_SECURITY:
                default:
-                       printf(" IPOPT-%d{%d}", cp[0], len);
                        break;
                }
        }
-       return;
+       return 0;
 
 trunc:
-       printf("[|ip]");
-}
-
-/*
- * compute an IP header checksum.
- * don't modifiy the packet.
- */
-u_short
-in_cksum(const u_short *addr, register u_int len, int csum)
-{
-       int nleft = len;
-       const u_short *w = addr;
-       u_short answer;
-       int sum = csum;
-
-       /*
-        *  Our algorithm is simple, using a 32 bit accumulator (sum),
-        *  we add sequential 16 bit words to it, and at the end, fold
-        *  back all the carry bits from the top 16 bits into the lower
-        *  16 bits.
-        */
-       while (nleft > 1)  {
-               sum += *w++;
-               nleft -= 2;
-       }
-       if (nleft == 1)
-               sum += htons(*(u_char *)w<<8);
-
-       /*
-        * add back carry outs from top 16 bits to low 16 bits
-        */
-       sum = (sum >> 16) + (sum & 0xffff);     /* add hi 16 to low 16 */
-       sum += (sum >> 16);                     /* add carry */
-       answer = ~sum;                          /* truncate to 16 bits */
-       return (answer);
+       return -1;
 }
 
-/*
- * Given the host-byte-order value of the checksum field in a packet
- * header, and the network-byte-order computed checksum of the data
- * that the checksum covers (including the checksum itself), compute
- * what the checksum field *should* have been.
- */
-u_int16_t
-in_cksum_shouldbe(u_int16_t sum, u_int16_t computed_sum)
-{
-       u_int32_t shouldbe;
-
-       /*
-        * The value that should have gone into the checksum field
-        * is the negative of the value gotten by summing up everything
-        * *but* the checksum field.
-        *
-        * We can compute that by subtracting the value of the checksum
-        * field from the sum of all the data in the packet, and then
-        * computing the negative of that value.
-        *
-        * "sum" is the value of the checksum field, and "computed_sum"
-        * is the negative of the sum of all the data in the packets,
-        * so that's -(-computed_sum - sum), or (sum + computed_sum).
-        *
-        * All the arithmetic in question is one's complement, so the
-        * addition must include an end-around carry; we do this by
-        * doing the arithmetic in 32 bits (with no sign-extension),
-        * and then adding the upper 16 bits of the sum, which contain
-        * the carry, to the lower 16 bits of the sum, and then do it
-        * again in case *that* sum produced a carry.
-        *
-        * As RFC 1071 notes, the checksum can be computed without
-        * byte-swapping the 16-bit words; summing 16-bit words
-        * on a big-endian machine gives a big-endian checksum, which
-        * can be directly stuffed into the big-endian checksum fields
-        * in protocol headers, and summing words on a little-endian
-        * machine gives a little-endian checksum, which must be
-        * byte-swapped before being stuffed into a big-endian checksum
-        * field.
-        *
-        * "computed_sum" is a network-byte-order value, so we must put
-        * it in host byte order before subtracting it from the
-        * host-byte-order value from the header; the adjusted checksum
-        * will be in host byte order, which is what we'll return.
-        */
-       shouldbe = sum;
-       shouldbe += ntohs(computed_sum);
-       shouldbe = (shouldbe & 0xFFFF) + (shouldbe >> 16);
-       shouldbe = (shouldbe & 0xFFFF) + (shouldbe >> 16);
-       return shouldbe;
-}
-
-#ifndef IP_MF
-#define IP_MF 0x2000
-#endif /* IP_MF */
-#ifndef IP_DF
-#define IP_DF 0x4000
-#endif /* IP_DF */
 #define IP_RES 0x8000
 
-static struct tok ip_frag_values[] = {
+static const struct tok ip_frag_values[] = {
         { IP_MF,        "+" },
         { IP_DF,        "DF" },
        { IP_RES,       "rsvd" }, /* The RFC3514 evil ;-) bit */
         { 0,            NULL }
 };
 
+
 /*
  * print an IP datagram.
  */
 void
-ip_print(register const u_char *bp, register u_int length)
+ip_print(netdissect_options *ndo,
+        const u_char *bp,
+        u_int length)
 {
-       register const struct ip *ip;
-       register u_int hlen, len, len0, off;
-       const u_char *ipend;
-       register const u_char *cp;
-       u_char nh;
-       int advance;
-       struct protoent *proto;
-       u_int16_t sum, ip_sum;
-
+       const struct ip *ip;
+       u_int off;
+       u_int hlen;
+       u_int len;
+       struct cksum_vec vec[1];
+       uint8_t ip_tos, ip_ttl, ip_proto;
+       uint16_t sum, ip_sum;
+       const char *p_name;
+       int truncated = 0;
+
+       ndo->ndo_protocol = "ip";
        ip = (const struct ip *)bp;
-       if (IP_V(ip) != 4) { /* print version if != 4 */
-           printf("IP%u ", IP_V(ip));
+       if (IP_V(ip) != 4) { /* print version and fail if != 4 */
            if (IP_V(ip) == 6)
-               printf(", wrong link-layer encapsulation");
+             ND_PRINT("IP6, wrong link-layer encapsulation");
+           else
+             ND_PRINT("IP%u", IP_V(ip));
+           nd_print_invalid(ndo);
+           return;
        }
-        else
-           printf("IP ");
+       if (!ndo->ndo_eflag)
+               ND_PRINT("IP ");
 
-       if ((u_char *)(ip + 1) > snapend) {
-               printf("[|ip]");
-               return;
-       }
+       ND_TCHECK_SIZE(ip);
        if (length < sizeof (struct ip)) {
-               (void)printf("truncated-ip %d", length);
+               ND_PRINT("truncated-ip %u", length);
                return;
        }
        hlen = IP_HL(ip) * 4;
        if (hlen < sizeof (struct ip)) {
-               (void)printf("bad-hlen %u", hlen);
+               ND_PRINT("bad-hlen %u", hlen);
                return;
        }
 
-       len = EXTRACT_16BITS(&ip->ip_len);
+       len = GET_BE_U_2(ip->ip_len);
        if (length < len)
-               (void)printf("truncated-ip - %u bytes missing! ",
+               ND_PRINT("truncated-ip - %u bytes missing! ",
                        len - length);
        if (len < hlen) {
-               (void)printf("bad-len %u", len);
-               return;
+#ifdef GUESS_TSO
+            if (len) {
+                ND_PRINT("bad-len %u", len);
+                return;
+            }
+            else {
+                /* we guess that it is a TSO send */
+                len = length;
+            }
+#else
+            ND_PRINT("bad-len %u", len);
+            return;
+#endif /* GUESS_TSO */
        }
 
        /*
         * Cut off the snapshot length to the end of the IP payload.
         */
-       ipend = bp + len;
-       if (ipend < snapend)
-               snapend = ipend;
+       nd_push_snapend(ndo, bp + len);
 
        len -= hlen;
-       len0 = len;
 
-       off = EXTRACT_16BITS(&ip->ip_off);
+       off = GET_BE_U_2(ip->ip_off);
+
+        ip_proto = GET_U_1(ip->ip_p);
 
-        if (vflag) {
-            (void)printf("(tos 0x%x", (int)ip->ip_tos);
+        if (ndo->ndo_vflag) {
+            ip_tos = GET_U_1(ip->ip_tos);
+            ND_PRINT("(tos 0x%x", ip_tos);
             /* ECN bits */
-            if (ip->ip_tos & 0x03) {
-                switch (ip->ip_tos & 0x03) {
-                case 1:
-                    (void)printf(",ECT(1)");
-                    break;
-                case 2:
-                    (void)printf(",ECT(0)");
-                    break;
-                case 3:
-                    (void)printf(",CE");
-                }
+            switch (ip_tos & 0x03) {
+
+            case 0:
+                break;
+
+            case 1:
+                ND_PRINT(",ECT(1)");
+                break;
+
+            case 2:
+                ND_PRINT(",ECT(0)");
+                break;
+
+            case 3:
+                ND_PRINT(",CE");
+                break;
             }
 
-            if (ip->ip_ttl >= 1)
-                (void)printf(", ttl %3u", ip->ip_ttl);    
+            ip_ttl = GET_U_1(ip->ip_ttl);
+            if (ip_ttl >= 1)
+                ND_PRINT(", ttl %u", ip_ttl);
 
            /*
             * for the firewall guys, print id, offset.
              * On all but the last stick a "+" in the flags portion.
             * For unfragmented datagrams, note the don't fragment flag.
             */
+           ND_PRINT(", id %u, offset %u, flags [%s], proto %s (%u)",
+                         GET_BE_U_2(ip->ip_id),
+                         (off & IP_OFFMASK) * 8,
+                         bittok2str(ip_frag_values, "none", off & (IP_RES|IP_DF|IP_MF)),
+                         tok2str(ipproto_values, "unknown", ip_proto),
+                         ip_proto);
 
-           (void)printf(", id %u, offset %u, flags [%s], proto: %s (%u)",
-                         EXTRACT_16BITS(&ip->ip_id),
-                         (off & 0x1fff) * 8,
-                         bittok2str(ip_frag_values, "none", off & 0xe000 ),
-                         tok2str(ipproto_values,"unknown",ip->ip_p),
-                         ip->ip_p);
-
-            (void)printf(", length: %u", EXTRACT_16BITS(&ip->ip_len));
+            ND_PRINT(", length %u", GET_BE_U_2(ip->ip_len));
 
             if ((hlen - sizeof(struct ip)) > 0) {
-                (void)printf(", optlength: %u (", hlen - (u_int)sizeof(struct ip));
-                ip_optprint((u_char *)(ip + 1), hlen - sizeof(struct ip));
-                printf(" )");
+                ND_PRINT(", options (");
+                if (ip_optprint(ndo, (const u_char *)(ip + 1),
+                    hlen - sizeof(struct ip)) == -1) {
+                        ND_PRINT(" [truncated-option]");
+                       truncated = 1;
+                }
+                ND_PRINT(")");
             }
 
-           if ((u_char *)ip + hlen <= snapend) {
-               sum = in_cksum((const u_short *)ip, hlen, 0);
+           if (!ndo->ndo_Kflag && (const u_char *)ip + hlen <= ndo->ndo_snapend) {
+               vec[0].ptr = (const uint8_t *)(const void *)ip;
+               vec[0].len = hlen;
+               sum = in_cksum(vec, 1);
                if (sum != 0) {
-                   ip_sum = EXTRACT_16BITS(&ip->ip_sum);
-                   (void)printf(", bad cksum %x (->%x)!", ip_sum,
+                   ip_sum = GET_BE_U_2(ip->ip_sum);
+                   ND_PRINT(", bad cksum %x (->%x)!", ip_sum,
                             in_cksum_shouldbe(ip_sum, sum));
                }
            }
 
-            printf(") ");
+           ND_PRINT(")\n    ");
+           if (truncated) {
+               ND_PRINT("%s > %s: ",
+                        GET_IPADDR_STRING(ip->ip_src),
+                        GET_IPADDR_STRING(ip->ip_dst));
+               nd_print_trunc(ndo);
+               nd_pop_packet_info(ndo);
+               return;
+           }
        }
 
        /*
         * If this is fragment zero, hand it to the next higher
-        * level protocol.
+        * level protocol.  Let them know whether there are more
+        * fragments.
         */
-       if ((off & 0x1fff) == 0) {
-               cp = (const u_char *)ip + hlen;
-               nh = ip->ip_p;
+       if ((off & IP_OFFMASK) == 0) {
+               uint8_t nh = GET_U_1(ip->ip_p);
 
                if (nh != IPPROTO_TCP && nh != IPPROTO_UDP &&
-                   nh != IPPROTO_SCTP) {
-                       (void)printf("%s > %s: ", ipaddr_string(&ip->ip_src),
-                               ipaddr_string(&ip->ip_dst));
-               }
-again:
-               switch (nh) {
-
-               case IPPROTO_AH:
-                       nh = *cp;
-                       advance = ah_print(cp);
-                       if (advance <= 0)
-                               break;
-                       cp += advance;
-                       len -= advance;
-                       goto again;
-
-               case IPPROTO_ESP:
-                   {
-                       int enh, padlen;
-                       advance = esp_print(gndo, cp, (const u_char *)ip, &enh, &padlen);
-                       if (advance <= 0)
-                               break;
-                       cp += advance;
-                       len -= advance + padlen;
-                       nh = enh & 0xff;
-                       goto again;
-                   }
-
-               case IPPROTO_IPCOMP:
-                   {
-                       int enh;
-                       advance = ipcomp_print(cp, &enh);
-                       if (advance <= 0)
-                               break;
-                       cp += advance;
-                       len -= advance;
-                       nh = enh & 0xff;
-                       goto again;
-                   }
-
-               case IPPROTO_SCTP:
-                       sctp_print(cp, (const u_char *)ip, len);
-                       break;
-
-               case IPPROTO_TCP:
-                       tcp_print(cp, len, (const u_char *)ip, (off &~ 0x6000));
-                       break;
-
-               case IPPROTO_UDP:
-                       udp_print(cp, len, (const u_char *)ip, (off &~ 0x6000));
-                       break;
-
-               case IPPROTO_ICMP:
-                       /* pass on the MF bit plus the offset to detect fragments */
-                       icmp_print(cp, len, (const u_char *)ip, (off & 0x3fff));
-                       break;
-
-                case IPPROTO_IGRP:
-               case IPPROTO_EIGRP:
-                       igrp_print(cp, len, (const u_char *)ip);
-                       break;
-
-               case IPPROTO_ND:
-                       (void)printf(" nd %d", len);
-                       break;
-
-               case IPPROTO_EGP:
-                       egp_print(cp);
-                       break;
-
-               case IPPROTO_OSPF:
-                       ospf_print(cp, len, (const u_char *)ip);
-                       break;
-
-               case IPPROTO_IGMP:
-                       igmp_print(cp, len);
-                       break;
-
-               case IPPROTO_IPV4:
-                       /* DVMRP multicast tunnel (ip-in-ip encapsulation) */
-                       ip_print(cp, len);
-                       if (! vflag) {
-                               printf(" (ipip-proto-4)");
-                               return;
-                       }
-                       break;
-
-#ifdef INET6
-               case IPPROTO_IPV6:
-                       /* ip6-in-ip encapsulation */
-                       ip6_print(cp, len);
-                       break;
-#endif /*INET6*/
-
-               case IPPROTO_RSVP:
-                       rsvp_print(cp, len);
-                       break;
-
-               case IPPROTO_GRE:
-                       /* do it */
-                       gre_print(cp, len);
-                       break;
-
-               case IPPROTO_MOBILE:
-                       mobile_print(cp, len);
-                       break;
-
-               case IPPROTO_PIM:
-                       pim_print(cp, len);
-                       break;
-
-               case IPPROTO_VRRP:
-                       vrrp_print(cp, len, ip->ip_ttl);
-                       break;
-
-               default:
-                       if ((proto = getprotobynumber(nh)) != NULL)
-                               (void)printf(" %s", proto->p_name);
-                       else
-                               (void)printf(" ip-proto-%d", nh);
-                       printf(" %d", len);
-                       break;
+                   nh != IPPROTO_SCTP && nh != IPPROTO_DCCP) {
+                       ND_PRINT("%s > %s: ",
+                                    GET_IPADDR_STRING(ip->ip_src),
+                                    GET_IPADDR_STRING(ip->ip_dst));
                }
+               ip_demux_print(ndo, (const u_char *)ip + hlen, len, 4,
+                   off & IP_MF, GET_U_1(ip->ip_ttl), nh, bp);
        } else {
-           /* Ultra quiet now means that all this stuff should be suppressed */
-           if (qflag > 1) return;
+               /*
+                * Ultra quiet now means that all this stuff should be
+                * suppressed.
+                */
+               if (ndo->ndo_qflag > 1) {
+                       nd_pop_packet_info(ndo);
+                       return;
+               }
 
-           /*
-            * if this isn't the first frag, we're missing the
-            * next level protocol header.  print the ip addr
-            * and the protocol.
-            */
-           if (off & 0x1fff) {
-               (void)printf("%s > %s:", ipaddr_string(&ip->ip_src),
-                            ipaddr_string(&ip->ip_dst));
-               if ((proto = getprotobynumber(ip->ip_p)) != NULL)
-                   (void)printf(" %s", proto->p_name);
+               /*
+                * This isn't the first frag, so we're missing the
+                * next level protocol header.  print the ip addr
+                * and the protocol.
+                */
+               ND_PRINT("%s > %s:", GET_IPADDR_STRING(ip->ip_src),
+                         GET_IPADDR_STRING(ip->ip_dst));
+               if (!ndo->ndo_nflag && (p_name = netdb_protoname(ip_proto)) != NULL)
+                       ND_PRINT(" %s", p_name);
                else
-                   (void)printf(" ip-proto-%d", ip->ip_p);
-           } 
+                       ND_PRINT(" ip-proto-%u", ip_proto);
        }
+       nd_pop_packet_info(ndo);
+       return;
+
+trunc:
+       nd_print_trunc(ndo);
+       return;
 }
 
 void
-ipN_print(register const u_char *bp, register u_int length)
+ipN_print(netdissect_options *ndo, const u_char *bp, u_int length)
 {
-       struct ip *ip, hdr;
-
-       ip = (struct ip *)bp;
-       if (length < 4) {
-               (void)printf("truncated-ip %d", length);
+       ndo->ndo_protocol = "ipn";
+       if (length < 1) {
+               ND_PRINT("truncated-ip %u", length);
                return;
        }
-       memcpy (&hdr, (char *)ip, 4);
-       switch (IP_V(&hdr)) {
-       case 4:
-               ip_print (bp, length);
-               return;
-#ifdef INET6
-       case 6:
-               ip6_print (bp, length);
-               return;
-#endif
+
+       switch (GET_U_1(bp) & 0xF0) {
+       case 0x40:
+               ip_print(ndo, bp, length);
+               break;
+       case 0x60:
+               ip6_print(ndo, bp, length);
+               break;
        default:
-               (void)printf("unknown ip %d", IP_V(&hdr));
-               return;
+               ND_PRINT("unknown ip %u", (GET_U_1(bp) & 0xF0) >> 4);
+               break;
        }
 }
-
-
-