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-rw-r--r--print-ip.c538
1 files changed, 538 insertions, 0 deletions
diff --git a/print-ip.c b/print-ip.c
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index 0000000..23ba99c
--- /dev/null
+++ b/print-ip.c
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+/*
+ * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
+ * The Regents of the University of California. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that: (1) source code distributions
+ * retain the above copyright notice and this paragraph in its entirety, (2)
+ * distributions including binary code include the above copyright notice and
+ * this paragraph in its entirety in the documentation or other materials
+ * provided with the distribution, and (3) all advertising materials mentioning
+ * features or use of this software display the following acknowledgement:
+ * ``This product includes software developed by the University of California,
+ * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
+ * the University nor the names of its contributors may be used to endorse
+ * or promote products derived from this software without specific prior
+ * written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+/* \summary: IP printer */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "netdissect-stdinc.h"
+
+#include "netdissect.h"
+#include "addrtoname.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 int
+ip_printroute(netdissect_options *ndo,
+ const u_char *cp, u_int length)
+{
+ u_int ptr;
+ u_int len;
+
+ if (length < 3) {
+ ND_PRINT(" [bad length %u]", length);
+ return (0);
+ }
+ if ((length + 1) & 3)
+ ND_PRINT(" [bad length %u]", length);
+ ptr = GET_U_1(cp + 2) - 1;
+ if (ptr < 3 || ((ptr + 1) & 3) || ptr > length + 1)
+ ND_PRINT(" [bad ptr %u]", GET_U_1(cp + 2));
+
+ for (len = 3; len < length; len += 4) {
+ ND_TCHECK_4(cp + len); /* Needed to print the IP addresses */
+ ND_PRINT(" %s", GET_IPADDR_STRING(cp + len));
+ if (ptr > len)
+ ND_PRINT(",");
+ }
+ return (0);
+
+trunc:
+ return (-1);
+}
+
+/*
+ * 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.
+ */
+static uint32_t
+ip_finddst(netdissect_options *ndo,
+ const struct ip *ip)
+{
+ u_int length;
+ u_int len;
+ const u_char *cp;
+
+ cp = (const u_char *)(ip + 1);
+ length = IP_HL(ip) * 4;
+ if (length < sizeof(struct ip))
+ goto trunc;
+ length -= sizeof(struct ip);
+
+ for (; length != 0; cp += len, length -= len) {
+ int tt;
+
+ tt = GET_U_1(cp);
+ if (tt == IPOPT_EOL)
+ break;
+ else if (tt == IPOPT_NOP)
+ len = 1;
+ else {
+ len = GET_U_1(cp + 1);
+ if (len < 2)
+ break;
+ }
+ if (length < len)
+ goto trunc;
+ ND_TCHECK_LEN(cp, len);
+ switch (tt) {
+
+ case IPOPT_SSRR:
+ case IPOPT_LSRR:
+ if (len < 7)
+ break;
+ return (GET_IPV4_TO_NETWORK_ORDER(cp + len - 4));
+ }
+ }
+trunc:
+ 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 int
+ip_printts(netdissect_options *ndo,
+ const u_char *cp, u_int length)
+{
+ u_int ptr;
+ u_int len;
+ u_int hoplen;
+ const char *type;
+
+ if (length < 4) {
+ ND_PRINT("[bad length %u]", length);
+ return (0);
+ }
+ ND_PRINT(" TS{");
+ hoplen = ((GET_U_1(cp + 3) & 0xF) != IPOPT_TS_TSONLY) ? 8 : 4;
+ if ((length - 4) & (hoplen-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)
+ ND_PRINT("[bad ptr %u]", GET_U_1(cp + 2));
+ switch (GET_U_1(cp + 3)&0xF) {
+ case IPOPT_TS_TSONLY:
+ ND_PRINT("TSONLY");
+ break;
+ case IPOPT_TS_TSANDADDR:
+ ND_PRINT("TS+ADDR");
+ break;
+ case IPOPT_TS_PRESPEC:
+ ND_PRINT("PRESPEC");
+ break;
+ default:
+ ND_PRINT("[bad ts type %u]", GET_U_1(cp + 3)&0xF);
+ goto done;
+ }
+
+ type = " ";
+ for (len = 4; len < length; len += hoplen) {
+ if (ptr == len)
+ type = " ^ ";
+ 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:
+ ND_PRINT("%s", ptr == len ? " ^ " : "");
+
+ if (GET_U_1(cp + 3) >> 4)
+ ND_PRINT(" [%u hops not recorded]} ", GET_U_1(cp + 3)>>4);
+ else
+ ND_PRINT("}");
+ return (0);
+
+trunc:
+ return (-1);
+}
+
+/*
+ * print IP options.
+ If truncated return -1, else 0.
+ */
+static int
+ip_optprint(netdissect_options *ndo,
+ const u_char *cp, u_int length)
+{
+ u_int option_len;
+ const char *sep = "";
+
+ 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;
+
+ else {
+ option_len = GET_U_1(cp + 1);
+ if (option_len < 2) {
+ ND_PRINT(" [bad length %u]", option_len);
+ return 0;
+ }
+ }
+
+ if (option_len > length) {
+ ND_PRINT(" [bad length %u]", option_len);
+ return 0;
+ }
+
+ ND_TCHECK_LEN(cp, option_len);
+
+ switch (option_code) {
+ case IPOPT_EOL:
+ return 0;
+
+ case IPOPT_TS:
+ if (ip_printts(ndo, cp, option_len) == -1)
+ goto trunc;
+ break;
+
+ case IPOPT_RR: /* fall through */
+ case IPOPT_SSRR:
+ case IPOPT_LSRR:
+ if (ip_printroute(ndo, cp, option_len) == -1)
+ goto trunc;
+ break;
+
+ case IPOPT_RA:
+ 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:
+ break;
+ }
+ }
+ return 0;
+
+trunc:
+ return -1;
+}
+
+#define IP_RES 0x8000
+
+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(netdissect_options *ndo,
+ const u_char *bp,
+ u_int length)
+{
+ 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 and fail if != 4 */
+ if (IP_V(ip) == 6)
+ ND_PRINT("IP6, wrong link-layer encapsulation");
+ else
+ ND_PRINT("IP%u", IP_V(ip));
+ nd_print_invalid(ndo);
+ return;
+ }
+ if (!ndo->ndo_eflag)
+ ND_PRINT("IP ");
+
+ ND_TCHECK_SIZE(ip);
+ if (length < sizeof (struct ip)) {
+ ND_PRINT("truncated-ip %u", length);
+ return;
+ }
+ hlen = IP_HL(ip) * 4;
+ if (hlen < sizeof (struct ip)) {
+ ND_PRINT("bad-hlen %u", hlen);
+ return;
+ }
+
+ len = GET_BE_U_2(ip->ip_len);
+ if (length < len)
+ ND_PRINT("truncated-ip - %u bytes missing! ",
+ len - length);
+ if (len < hlen) {
+#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.
+ */
+ if (!nd_push_snaplen(ndo, bp, len)) {
+ (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC,
+ "%s: can't push snaplen on buffer stack", __func__);
+ }
+
+ len -= hlen;
+
+ off = GET_BE_U_2(ip->ip_off);
+
+ ip_proto = GET_U_1(ip->ip_p);
+
+ if (ndo->ndo_vflag) {
+ ip_tos = GET_U_1(ip->ip_tos);
+ ND_PRINT("(tos 0x%x", ip_tos);
+ /* ECN bits */
+ 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;
+ }
+
+ 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);
+
+ ND_PRINT(", length %u", GET_BE_U_2(ip->ip_len));
+
+ if ((hlen - sizeof(struct ip)) > 0) {
+ 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 (!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 = GET_BE_U_2(ip->ip_sum);
+ ND_PRINT(", bad cksum %x (->%x)!", ip_sum,
+ in_cksum_shouldbe(ip_sum, sum));
+ }
+ }
+
+ 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. Let them know whether there are more
+ * fragments.
+ */
+ if ((off & IP_OFFMASK) == 0) {
+ uint8_t nh = GET_U_1(ip->ip_p);
+
+ if (nh != IPPROTO_TCP && nh != IPPROTO_UDP &&
+ nh != IPPROTO_SCTP && nh != IPPROTO_DCCP) {
+ ND_PRINT("%s > %s: ",
+ GET_IPADDR_STRING(ip->ip_src),
+ GET_IPADDR_STRING(ip->ip_dst));
+ }
+ /*
+ * Do a bounds check before calling ip_demux_print().
+ * At least the header data is required.
+ */
+ if (!ND_TTEST_LEN((const u_char *)ip, hlen)) {
+ ND_PRINT(" [remaining caplen(%u) < header length(%u)]",
+ ND_BYTES_AVAILABLE_AFTER((const u_char *)ip),
+ hlen);
+ nd_trunc_longjmp(ndo);
+ }
+ 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 (ndo->ndo_qflag > 1) {
+ nd_pop_packet_info(ndo);
+ return;
+ }
+
+ /*
+ * 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
+ ND_PRINT(" ip-proto-%u", ip_proto);
+ }
+ nd_pop_packet_info(ndo);
+ return;
+
+trunc:
+ nd_print_trunc(ndo);
+}
+
+void
+ipN_print(netdissect_options *ndo, const u_char *bp, u_int length)
+{
+ ndo->ndo_protocol = "ipn";
+ if (length < 1) {
+ ND_PRINT("truncated-ip %u", length);
+ return;
+ }
+
+ switch (GET_U_1(bp) & 0xF0) {
+ case 0x40:
+ ip_print(ndo, bp, length);
+ break;
+ case 0x60:
+ ip6_print(ndo, bp, length);
+ break;
+ default:
+ ND_PRINT("unknown ip %u", (GET_U_1(bp) & 0xF0) >> 4);
+ break;
+ }
+}
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