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-rw-r--r--contrib/tcpdump/print-ip.c742
1 files changed, 742 insertions, 0 deletions
diff --git a/contrib/tcpdump/print-ip.c b/contrib/tcpdump/print-ip.c
new file mode 100644
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--- /dev/null
+++ b/contrib/tcpdump/print-ip.c
@@ -0,0 +1,742 @@
+/*
+ * 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef lint
+static const char rcsid[] _U_ =
+ "@(#) $Header: /tcpdump/master/tcpdump/print-ip.c,v 1.159 2007-09-14 01:29:28 guy Exp $ (LBL)";
+#endif
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <tcpdump-stdinc.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "addrtoname.h"
+#include "interface.h"
+#include "extract.h" /* must come after interface.h */
+
+#include "ip.h"
+#include "ipproto.h"
+
+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(register const u_char *cp, u_int length)
+{
+ register u_int ptr;
+ register u_int len;
+
+ if (length < 3) {
+ printf(" [bad length %u]", length);
+ return;
+ }
+ if ((length + 1) & 3)
+ printf(" [bad length %u]", length);
+ ptr = cp[2] - 1;
+ if (ptr < 3 || ((ptr + 1) & 3) || ptr > length + 1)
+ printf(" [bad ptr %u]", cp[2]);
+
+ for (len = 3; len < length; len += 4) {
+ printf(" %s", ipaddr_string(&cp[len]));
+ if (ptr > len)
+ printf(",");
+ }
+}
+
+/*
+ * 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)
+{
+ int length;
+ int len;
+ const u_char *cp;
+ u_int32_t retval;
+
+ cp = (const u_char *)(ip + 1);
+ length = (IP_HL(ip) << 2) - sizeof(struct ip);
+
+ for (; length > 0; cp += len, length -= len) {
+ int tt;
+
+ TCHECK(*cp);
+ tt = *cp;
+ if (tt == IPOPT_EOL)
+ break;
+ else if (tt == IPOPT_NOP)
+ len = 1;
+ else {
+ TCHECK(cp[1]);
+ len = cp[1];
+ if (len < 2)
+ break;
+ }
+ TCHECK2(*cp, len);
+ switch (tt) {
+
+ case IPOPT_SSRR:
+ case IPOPT_LSRR:
+ if (len < 7)
+ break;
+ memcpy(&retval, cp + len - 4, 4);
+ return retval;
+ }
+ }
+trunc:
+ memcpy(&retval, &ip->ip_dst.s_addr, sizeof(u_int32_t));
+ return retval;
+}
+
+static void
+ip_printts(register const u_char *cp, u_int length)
+{
+ register u_int ptr;
+ register u_int len;
+ int hoplen;
+ const char *type;
+
+ if (length < 4) {
+ printf("[bad length %u]", length);
+ return;
+ }
+ printf(" TS{");
+ hoplen = ((cp[3]&0xF) != IPOPT_TS_TSONLY) ? 8 : 4;
+ if ((length - 4) & (hoplen-1))
+ printf("[bad length %u]", length);
+ ptr = cp[2] - 1;
+ len = 0;
+ if (ptr < 4 || ((ptr - 4) & (hoplen-1)) || ptr > length + 1)
+ printf("[bad ptr %u]", cp[2]);
+ switch (cp[3]&0xF) {
+ case IPOPT_TS_TSONLY:
+ printf("TSONLY");
+ break;
+ case IPOPT_TS_TSANDADDR:
+ printf("TS+ADDR");
+ break;
+ /*
+ * prespecified should really be 3, but some ones might send 2
+ * instead, and the IPOPT_TS_PRESPEC constant can apparently
+ * have both values, so we have to hard-code it here.
+ */
+
+ case 2:
+ printf("PRESPEC2.0");
+ break;
+ case 3: /* IPOPT_TS_PRESPEC */
+ printf("PRESPEC");
+ break;
+ default:
+ printf("[bad ts type %d]", cp[3]&0xF);
+ goto done;
+ }
+
+ type = " ";
+ 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]));
+ type = " ";
+ }
+
+done:
+ printf("%s", ptr == len ? " ^ " : "");
+
+ if (cp[3]>>4)
+ printf(" [%d hops not recorded]} ", cp[3]>>4);
+ else
+ printf("}");
+}
+
+/*
+ * print IP options.
+ */
+static void
+ip_optprint(register const u_char *cp, u_int length)
+{
+ register u_int option_len;
+ const char *sep = "";
+
+ for (; length > 0; cp += option_len, length -= option_len) {
+ u_int option_code;
+
+ printf("%s", sep);
+ sep = ",";
+
+ TCHECK(*cp);
+ option_code = *cp;
+
+ printf("%s",
+ tok2str(ip_option_values,"unknown %u",option_code));
+
+ if (option_code == IPOPT_NOP ||
+ option_code == IPOPT_EOL)
+ option_len = 1;
+
+ else {
+ TCHECK(cp[1]);
+ option_len = cp[1];
+ if (option_len < 2) {
+ printf(" [bad length %u]", option_len);
+ return;
+ }
+ }
+
+ if (option_len > length) {
+ printf(" [bad length %u]", option_len);
+ return;
+ }
+
+ TCHECK2(*cp, option_len);
+
+ switch (option_code) {
+ case IPOPT_EOL:
+ return;
+
+ case IPOPT_TS:
+ ip_printts(cp, option_len);
+ break;
+
+ case IPOPT_RR: /* fall through */
+ case IPOPT_SSRR:
+ case IPOPT_LSRR:
+ ip_printroute(cp, option_len);
+ break;
+
+ case IPOPT_RA:
+ if (option_len < 4) {
+ printf(" [bad length %u]", option_len);
+ break;
+ }
+ TCHECK(cp[3]);
+ if (EXTRACT_16BITS(&cp[2]) != 0)
+ printf(" value %u", EXTRACT_16BITS(&cp[2]));
+ break;
+
+ case IPOPT_NOP: /* nothing to print - fall through */
+ case IPOPT_SECURITY:
+ default:
+ break;
+ }
+ }
+ return;
+
+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);
+}
+
+/*
+ * 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;
+}
+
+#define IP_RES 0x8000
+
+static struct tok ip_frag_values[] = {
+ { IP_MF, "+" },
+ { IP_DF, "DF" },
+ { IP_RES, "rsvd" }, /* The RFC3514 evil ;-) bit */
+ { 0, NULL }
+};
+
+struct ip_print_demux_state {
+ const struct ip *ip;
+ const u_char *cp;
+ u_int len, off;
+ u_char nh;
+ int advance;
+};
+
+static void
+ip_print_demux(netdissect_options *ndo,
+ struct ip_print_demux_state *ipds)
+{
+ struct protoent *proto;
+
+again:
+ switch (ipds->nh) {
+
+ case IPPROTO_AH:
+ ipds->nh = *ipds->cp;
+ ipds->advance = ah_print(ipds->cp);
+ if (ipds->advance <= 0)
+ break;
+ ipds->cp += ipds->advance;
+ ipds->len -= ipds->advance;
+ goto again;
+
+ case IPPROTO_ESP:
+ {
+ int enh, padlen;
+ ipds->advance = esp_print(ndo, ipds->cp, ipds->len,
+ (const u_char *)ipds->ip,
+ &enh, &padlen);
+ if (ipds->advance <= 0)
+ break;
+ ipds->cp += ipds->advance;
+ ipds->len -= ipds->advance + padlen;
+ ipds->nh = enh & 0xff;
+ goto again;
+ }
+
+ case IPPROTO_IPCOMP:
+ {
+ int enh;
+ ipds->advance = ipcomp_print(ipds->cp, &enh);
+ if (ipds->advance <= 0)
+ break;
+ ipds->cp += ipds->advance;
+ ipds->len -= ipds->advance;
+ ipds->nh = enh & 0xff;
+ goto again;
+ }
+
+ case IPPROTO_SCTP:
+ sctp_print(ipds->cp, (const u_char *)ipds->ip, ipds->len);
+ break;
+
+ case IPPROTO_DCCP:
+ dccp_print(ipds->cp, (const u_char *)ipds->ip, ipds->len);
+ break;
+
+ case IPPROTO_TCP:
+ /* pass on the MF bit plus the offset to detect fragments */
+ tcp_print(ipds->cp, ipds->len, (const u_char *)ipds->ip,
+ ipds->off & (IP_MF|IP_OFFMASK));
+ break;
+
+ case IPPROTO_UDP:
+ /* pass on the MF bit plus the offset to detect fragments */
+ udp_print(ipds->cp, ipds->len, (const u_char *)ipds->ip,
+ ipds->off & (IP_MF|IP_OFFMASK));
+ break;
+
+ case IPPROTO_ICMP:
+ /* pass on the MF bit plus the offset to detect fragments */
+ icmp_print(ipds->cp, ipds->len, (const u_char *)ipds->ip,
+ ipds->off & (IP_MF|IP_OFFMASK));
+ break;
+
+ case IPPROTO_PIGP:
+ /*
+ * XXX - the current IANA protocol number assignments
+ * page lists 9 as "any private interior gateway
+ * (used by Cisco for their IGRP)" and 88 as
+ * "EIGRP" from Cisco.
+ *
+ * Recent BSD <netinet/in.h> headers define
+ * IP_PROTO_PIGP as 9 and IP_PROTO_IGRP as 88.
+ * We define IP_PROTO_PIGP as 9 and
+ * IP_PROTO_EIGRP as 88; those names better
+ * match was the current protocol number
+ * assignments say.
+ */
+ igrp_print(ipds->cp, ipds->len, (const u_char *)ipds->ip);
+ break;
+
+ case IPPROTO_EIGRP:
+ eigrp_print(ipds->cp, ipds->len);
+ break;
+
+ case IPPROTO_ND:
+ ND_PRINT((ndo, " nd %d", ipds->len));
+ break;
+
+ case IPPROTO_EGP:
+ egp_print(ipds->cp, ipds->len);
+ break;
+
+ case IPPROTO_OSPF:
+ ospf_print(ipds->cp, ipds->len, (const u_char *)ipds->ip);
+ break;
+
+ case IPPROTO_IGMP:
+ igmp_print(ipds->cp, ipds->len);
+ break;
+
+ case IPPROTO_IPV4:
+ /* DVMRP multicast tunnel (ip-in-ip encapsulation) */
+ ip_print(gndo, ipds->cp, ipds->len);
+ if (! vflag) {
+ ND_PRINT((ndo, " (ipip-proto-4)"));
+ return;
+ }
+ break;
+
+#ifdef INET6
+ case IPPROTO_IPV6:
+ /* ip6-in-ip encapsulation */
+ ip6_print(ipds->cp, ipds->len);
+ break;
+#endif /*INET6*/
+
+ case IPPROTO_RSVP:
+ rsvp_print(ipds->cp, ipds->len);
+ break;
+
+ case IPPROTO_GRE:
+ /* do it */
+ gre_print(ipds->cp, ipds->len);
+ break;
+
+ case IPPROTO_MOBILE:
+ mobile_print(ipds->cp, ipds->len);
+ break;
+
+ case IPPROTO_PIM:
+ pim_print(ipds->cp, ipds->len);
+ break;
+
+ case IPPROTO_VRRP:
+ vrrp_print(ipds->cp, ipds->len, ipds->ip->ip_ttl);
+ break;
+
+ case IPPROTO_PGM:
+ pgm_print(ipds->cp, ipds->len, (const u_char *)ipds->ip);
+ break;
+
+ default:
+ if ((proto = getprotobynumber(ipds->nh)) != NULL)
+ ND_PRINT((ndo, " %s", proto->p_name));
+ else
+ ND_PRINT((ndo, " ip-proto-%d", ipds->nh));
+ ND_PRINT((ndo, " %d", ipds->len));
+ break;
+ }
+}
+
+void
+ip_print_inner(netdissect_options *ndo,
+ const u_char *bp,
+ u_int length, u_int nh,
+ const u_char *bp2)
+{
+ struct ip_print_demux_state ipd;
+
+ ipd.ip = (const struct ip *)bp2;
+ ipd.cp = bp;
+ ipd.len = length;
+ ipd.off = 0;
+ ipd.nh = nh;
+ ipd.advance = 0;
+
+ ip_print_demux(ndo, &ipd);
+}
+
+
+/*
+ * print an IP datagram.
+ */
+void
+ip_print(netdissect_options *ndo,
+ const u_char *bp,
+ u_int length)
+{
+ struct ip_print_demux_state ipd;
+ struct ip_print_demux_state *ipds=&ipd;
+ const u_char *ipend;
+ u_int hlen;
+ u_int16_t sum, ip_sum;
+ struct protoent *proto;
+
+ ipds->ip = (const struct ip *)bp;
+ if (IP_V(ipds->ip) != 4) { /* print version if != 4 */
+ printf("IP%u ", IP_V(ipds->ip));
+ if (IP_V(ipds->ip) == 6)
+ printf(", wrong link-layer encapsulation");
+ }
+ else if (!eflag)
+ printf("IP ");
+
+ if ((u_char *)(ipds->ip + 1) > snapend) {
+ printf("[|ip]");
+ return;
+ }
+ if (length < sizeof (struct ip)) {
+ (void)printf("truncated-ip %u", length);
+ return;
+ }
+ hlen = IP_HL(ipds->ip) * 4;
+ if (hlen < sizeof (struct ip)) {
+ (void)printf("bad-hlen %u", hlen);
+ return;
+ }
+
+ ipds->len = EXTRACT_16BITS(&ipds->ip->ip_len);
+ if (length < ipds->len)
+ (void)printf("truncated-ip - %u bytes missing! ",
+ ipds->len - length);
+ if (ipds->len < hlen) {
+#ifdef GUESS_TSO
+ if (ipds->len) {
+ (void)printf("bad-len %u", ipds->len);
+ return;
+ }
+ else {
+ /* we guess that it is a TSO send */
+ ipds->len = length;
+ }
+#else
+ (void)printf("bad-len %u", ipds->len);
+ return;
+#endif /* GUESS_TSO */
+ }
+
+ /*
+ * Cut off the snapshot length to the end of the IP payload.
+ */
+ ipend = bp + ipds->len;
+ if (ipend < snapend)
+ snapend = ipend;
+
+ ipds->len -= hlen;
+
+ ipds->off = EXTRACT_16BITS(&ipds->ip->ip_off);
+
+ if (vflag) {
+ (void)printf("(tos 0x%x", (int)ipds->ip->ip_tos);
+ /* ECN bits */
+ if (ipds->ip->ip_tos & 0x03) {
+ switch (ipds->ip->ip_tos & 0x03) {
+ case 1:
+ (void)printf(",ECT(1)");
+ break;
+ case 2:
+ (void)printf(",ECT(0)");
+ break;
+ case 3:
+ (void)printf(",CE");
+ }
+ }
+
+ if (ipds->ip->ip_ttl >= 1)
+ (void)printf(", ttl %u", ipds->ip->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.
+ */
+
+ (void)printf(", id %u, offset %u, flags [%s], proto %s (%u)",
+ EXTRACT_16BITS(&ipds->ip->ip_id),
+ (ipds->off & 0x1fff) * 8,
+ bittok2str(ip_frag_values, "none", ipds->off&0xe000),
+ tok2str(ipproto_values,"unknown",ipds->ip->ip_p),
+ ipds->ip->ip_p);
+
+ (void)printf(", length %u", EXTRACT_16BITS(&ipds->ip->ip_len));
+
+ if ((hlen - sizeof(struct ip)) > 0) {
+ printf(", options (");
+ ip_optprint((u_char *)(ipds->ip + 1), hlen - sizeof(struct ip));
+ printf(")");
+ }
+
+ if ((u_char *)ipds->ip + hlen <= snapend) {
+ sum = in_cksum((const u_short *)ipds->ip, hlen, 0);
+ if (sum != 0) {
+ ip_sum = EXTRACT_16BITS(&ipds->ip->ip_sum);
+ (void)printf(", bad cksum %x (->%x)!", ip_sum,
+ in_cksum_shouldbe(ip_sum, sum));
+ }
+ }
+
+ printf(")\n ");
+ }
+
+ /*
+ * If this is fragment zero, hand it to the next higher
+ * level protocol.
+ */
+ if ((ipds->off & 0x1fff) == 0) {
+ ipds->cp = (const u_char *)ipds->ip + hlen;
+ ipds->nh = ipds->ip->ip_p;
+
+ if (ipds->nh != IPPROTO_TCP && ipds->nh != IPPROTO_UDP &&
+ ipds->nh != IPPROTO_SCTP && ipds->nh != IPPROTO_DCCP) {
+ (void)printf("%s > %s: ",
+ ipaddr_string(&ipds->ip->ip_src),
+ ipaddr_string(&ipds->ip->ip_dst));
+ }
+ ip_print_demux(ndo, ipds);
+ } else {
+ /* Ultra quiet now means that all this stuff should be suppressed */
+ if (qflag > 1) return;
+
+ /*
+ * if this isn't the first frag, we're missing the
+ * next level protocol header. print the ip addr
+ * and the protocol.
+ */
+ if (ipds->off & 0x1fff) {
+ (void)printf("%s > %s:", ipaddr_string(&ipds->ip->ip_src),
+ ipaddr_string(&ipds->ip->ip_dst));
+ if ((proto = getprotobynumber(ipds->ip->ip_p)) != NULL)
+ (void)printf(" %s", proto->p_name);
+ else
+ (void)printf(" ip-proto-%d", ipds->ip->ip_p);
+ }
+ }
+}
+
+void
+ipN_print(register const u_char *bp, register u_int length)
+{
+ struct ip *ip, hdr;
+
+ ip = (struct ip *)bp;
+ if (length < 4) {
+ (void)printf("truncated-ip %d", length);
+ return;
+ }
+ memcpy (&hdr, (char *)ip, 4);
+ switch (IP_V(&hdr)) {
+ case 4:
+ ip_print (gndo, bp, length);
+ return;
+#ifdef INET6
+ case 6:
+ ip6_print (bp, length);
+ return;
+#endif
+ default:
+ (void)printf("unknown ip %d", IP_V(&hdr));
+ return;
+ }
+}
+
+/*
+ * Local Variables:
+ * c-style: whitesmith
+ * c-basic-offset: 8
+ * End:
+ */
+
+
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