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-rw-r--r--print-ip6.c423
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diff --git a/print-ip6.c b/print-ip6.c
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+/*
+ * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994
+ * 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: IPv6 printer */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <netdissect-stdinc.h>
+
+#include <string.h>
+
+#include "netdissect.h"
+#include "addrtoname.h"
+#include "extract.h"
+
+#include "ip6.h"
+#include "ipproto.h"
+
+/*
+ * If routing headers are presend and valid, set dst to the final destination.
+ * Otherwise, set it to the IPv6 destination.
+ *
+ * This is used for UDP and TCP pseudo-header in the checksum
+ * calculation.
+ */
+static void
+ip6_finddst(netdissect_options *ndo, struct in6_addr *dst,
+ const struct ip6_hdr *ip6)
+{
+ const u_char *cp;
+ int advance;
+ u_int nh;
+ const struct in6_addr *dst_addr;
+ const struct ip6_rthdr *dp;
+ const struct ip6_rthdr0 *dp0;
+ const struct in6_addr *addr;
+ int i, len;
+
+ cp = (const u_char *)ip6;
+ advance = sizeof(struct ip6_hdr);
+ nh = ip6->ip6_nxt;
+ dst_addr = &ip6->ip6_dst;
+
+ while (cp < ndo->ndo_snapend) {
+ cp += advance;
+
+ switch (nh) {
+
+ case IPPROTO_HOPOPTS:
+ case IPPROTO_DSTOPTS:
+ case IPPROTO_MOBILITY_OLD:
+ case IPPROTO_MOBILITY:
+ /*
+ * These have a header length byte, following
+ * the next header byte, giving the length of
+ * the header, in units of 8 octets, excluding
+ * the first 8 octets.
+ */
+ ND_TCHECK2(*cp, 2);
+ advance = (int)((*(cp + 1) + 1) << 3);
+ nh = *cp;
+ break;
+
+ case IPPROTO_FRAGMENT:
+ /*
+ * The byte following the next header byte is
+ * marked as reserved, and the header is always
+ * the same size.
+ */
+ ND_TCHECK2(*cp, 1);
+ advance = sizeof(struct ip6_frag);
+ nh = *cp;
+ break;
+
+ case IPPROTO_ROUTING:
+ /*
+ * OK, we found it.
+ */
+ dp = (const struct ip6_rthdr *)cp;
+ ND_TCHECK(*dp);
+ len = dp->ip6r_len;
+ switch (dp->ip6r_type) {
+
+ case IPV6_RTHDR_TYPE_0:
+ case IPV6_RTHDR_TYPE_2: /* Mobile IPv6 ID-20 */
+ dp0 = (const struct ip6_rthdr0 *)dp;
+ if (len % 2 == 1)
+ goto trunc;
+ len >>= 1;
+ addr = &dp0->ip6r0_addr[0];
+ for (i = 0; i < len; i++) {
+ if ((const u_char *)(addr + 1) > ndo->ndo_snapend)
+ goto trunc;
+
+ dst_addr = addr;
+ addr++;
+ }
+ break;
+
+ default:
+ break;
+ }
+
+ /*
+ * Only one routing header to a customer.
+ */
+ goto done;
+
+ case IPPROTO_AH:
+ case IPPROTO_ESP:
+ case IPPROTO_IPCOMP:
+ default:
+ /*
+ * AH and ESP are, in the RFCs that describe them,
+ * described as being "viewed as an end-to-end
+ * payload" "in the IPv6 context, so that they
+ * "should appear after hop-by-hop, routing, and
+ * fragmentation extension headers". We assume
+ * that's the case, and stop as soon as we see
+ * one. (We can't handle an ESP header in
+ * the general case anyway, as its length depends
+ * on the encryption algorithm.)
+ *
+ * IPComp is also "viewed as an end-to-end
+ * payload" "in the IPv6 context".
+ *
+ * All other protocols are assumed to be the final
+ * protocol.
+ */
+ goto done;
+ }
+ }
+
+done:
+trunc:
+ UNALIGNED_MEMCPY(dst, dst_addr, sizeof(struct in6_addr));
+}
+
+/*
+ * Compute a V6-style checksum by building a pseudoheader.
+ */
+int
+nextproto6_cksum(netdissect_options *ndo,
+ const struct ip6_hdr *ip6, const uint8_t *data,
+ u_int len, u_int covlen, u_int next_proto)
+{
+ struct {
+ struct in6_addr ph_src;
+ struct in6_addr ph_dst;
+ uint32_t ph_len;
+ uint8_t ph_zero[3];
+ uint8_t ph_nxt;
+ } ph;
+ struct cksum_vec vec[2];
+
+ /* pseudo-header */
+ memset(&ph, 0, sizeof(ph));
+ UNALIGNED_MEMCPY(&ph.ph_src, &ip6->ip6_src, sizeof (struct in6_addr));
+ switch (ip6->ip6_nxt) {
+
+ case IPPROTO_HOPOPTS:
+ case IPPROTO_DSTOPTS:
+ case IPPROTO_MOBILITY_OLD:
+ case IPPROTO_MOBILITY:
+ case IPPROTO_FRAGMENT:
+ case IPPROTO_ROUTING:
+ /*
+ * The next header is either a routing header or a header
+ * after which there might be a routing header, so scan
+ * for a routing header.
+ */
+ ip6_finddst(ndo, &ph.ph_dst, ip6);
+ break;
+
+ default:
+ UNALIGNED_MEMCPY(&ph.ph_dst, &ip6->ip6_dst, sizeof (struct in6_addr));
+ break;
+ }
+ ph.ph_len = htonl(len);
+ ph.ph_nxt = next_proto;
+
+ 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);
+}
+
+/*
+ * print an IP6 datagram.
+ */
+void
+ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
+{
+ register const struct ip6_hdr *ip6;
+ register int advance;
+ u_int len;
+ const u_char *ipend;
+ register const u_char *cp;
+ register u_int payload_len;
+ int nh;
+ int fragmented = 0;
+ u_int flow;
+
+ ip6 = (const struct ip6_hdr *)bp;
+
+ ND_TCHECK(*ip6);
+ if (length < sizeof (struct ip6_hdr)) {
+ ND_PRINT((ndo, "truncated-ip6 %u", length));
+ return;
+ }
+
+ if (!ndo->ndo_eflag)
+ ND_PRINT((ndo, "IP6 "));
+
+ if (IP6_VERSION(ip6) != 6) {
+ ND_PRINT((ndo,"version error: %u != 6", IP6_VERSION(ip6)));
+ return;
+ }
+
+ payload_len = EXTRACT_16BITS(&ip6->ip6_plen);
+ len = payload_len + sizeof(struct ip6_hdr);
+ if (length < len)
+ ND_PRINT((ndo, "truncated-ip6 - %u bytes missing!",
+ len - length));
+
+ if (ndo->ndo_vflag) {
+ flow = EXTRACT_32BITS(&ip6->ip6_flow);
+ ND_PRINT((ndo, "("));
+#if 0
+ /* rfc1883 */
+ if (flow & 0x0f000000)
+ ND_PRINT((ndo, "pri 0x%02x, ", (flow & 0x0f000000) >> 24));
+ if (flow & 0x00ffffff)
+ ND_PRINT((ndo, "flowlabel 0x%06x, ", flow & 0x00ffffff));
+#else
+ /* RFC 2460 */
+ if (flow & 0x0ff00000)
+ ND_PRINT((ndo, "class 0x%02x, ", (flow & 0x0ff00000) >> 20));
+ if (flow & 0x000fffff)
+ ND_PRINT((ndo, "flowlabel 0x%05x, ", flow & 0x000fffff));
+#endif
+
+ ND_PRINT((ndo, "hlim %u, next-header %s (%u) payload length: %u) ",
+ ip6->ip6_hlim,
+ tok2str(ipproto_values,"unknown",ip6->ip6_nxt),
+ ip6->ip6_nxt,
+ payload_len));
+ }
+
+ /*
+ * Cut off the snapshot length to the end of the IP payload.
+ */
+ ipend = bp + len;
+ if (ipend < ndo->ndo_snapend)
+ ndo->ndo_snapend = ipend;
+
+ cp = (const u_char *)ip6;
+ advance = sizeof(struct ip6_hdr);
+ nh = ip6->ip6_nxt;
+ while (cp < ndo->ndo_snapend && advance > 0) {
+ if (len < (u_int)advance)
+ goto trunc;
+ cp += advance;
+ len -= advance;
+
+ if (cp == (const u_char *)(ip6 + 1) &&
+ nh != IPPROTO_TCP && nh != IPPROTO_UDP &&
+ nh != IPPROTO_DCCP && nh != IPPROTO_SCTP) {
+ ND_PRINT((ndo, "%s > %s: ", ip6addr_string(ndo, &ip6->ip6_src),
+ ip6addr_string(ndo, &ip6->ip6_dst)));
+ }
+
+ switch (nh) {
+ case IPPROTO_HOPOPTS:
+ advance = hbhopt_print(ndo, cp);
+ if (advance < 0)
+ return;
+ nh = *cp;
+ break;
+ case IPPROTO_DSTOPTS:
+ advance = dstopt_print(ndo, cp);
+ if (advance < 0)
+ return;
+ nh = *cp;
+ break;
+ case IPPROTO_FRAGMENT:
+ advance = frag6_print(ndo, cp, (const u_char *)ip6);
+ if (advance < 0 || ndo->ndo_snapend <= cp + advance)
+ return;
+ nh = *cp;
+ fragmented = 1;
+ break;
+
+ case IPPROTO_MOBILITY_OLD:
+ case IPPROTO_MOBILITY:
+ /*
+ * XXX - we don't use "advance"; RFC 3775 says that
+ * the next header field in a mobility header
+ * should be IPPROTO_NONE, but speaks of
+ * the possiblity of a future extension in
+ * which payload can be piggybacked atop a
+ * mobility header.
+ */
+ advance = mobility_print(ndo, cp, (const u_char *)ip6);
+ if (advance < 0)
+ return;
+ nh = *cp;
+ return;
+ case IPPROTO_ROUTING:
+ ND_TCHECK(*cp);
+ advance = rt6_print(ndo, cp, (const u_char *)ip6);
+ if (advance < 0)
+ return;
+ nh = *cp;
+ break;
+ case IPPROTO_SCTP:
+ sctp_print(ndo, cp, (const u_char *)ip6, len);
+ return;
+ case IPPROTO_DCCP:
+ dccp_print(ndo, cp, (const u_char *)ip6, len);
+ return;
+ case IPPROTO_TCP:
+ tcp_print(ndo, cp, len, (const u_char *)ip6, fragmented);
+ return;
+ case IPPROTO_UDP:
+ udp_print(ndo, cp, len, (const u_char *)ip6, fragmented);
+ return;
+ case IPPROTO_ICMPV6:
+ icmp6_print(ndo, cp, len, (const u_char *)ip6, fragmented);
+ return;
+ case IPPROTO_AH:
+ advance = ah_print(ndo, cp);
+ if (advance < 0)
+ return;
+ nh = *cp;
+ break;
+ case IPPROTO_ESP:
+ {
+ int enh, padlen;
+ advance = esp_print(ndo, cp, len, (const u_char *)ip6, &enh, &padlen);
+ if (advance < 0)
+ return;
+ nh = enh & 0xff;
+ len -= padlen;
+ break;
+ }
+ case IPPROTO_IPCOMP:
+ {
+ ipcomp_print(ndo, cp);
+ /*
+ * Either this has decompressed the payload and
+ * printed it, in which case there's nothing more
+ * to do, or it hasn't, in which case there's
+ * nothing more to do.
+ */
+ advance = -1;
+ break;
+ }
+
+ case IPPROTO_PIM:
+ pim_print(ndo, cp, len, (const u_char *)ip6);
+ return;
+
+ case IPPROTO_OSPF:
+ ospf6_print(ndo, cp, len);
+ return;
+
+ case IPPROTO_IPV6:
+ ip6_print(ndo, cp, len);
+ return;
+
+ case IPPROTO_IPV4:
+ ip_print(ndo, cp, len);
+ return;
+
+ case IPPROTO_PGM:
+ pgm_print(ndo, cp, len, (const u_char *)ip6);
+ return;
+
+ case IPPROTO_GRE:
+ gre_print(ndo, cp, len);
+ return;
+
+ case IPPROTO_RSVP:
+ rsvp_print(ndo, cp, len);
+ return;
+
+ case IPPROTO_NONE:
+ ND_PRINT((ndo, "no next header"));
+ return;
+
+ default:
+ ND_PRINT((ndo, "ip-proto-%d %d", nh, len));
+ return;
+ }
+ }
+
+ return;
+trunc:
+ ND_PRINT((ndo, "[|ip6]"));
+}
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