* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
-#ifdef HAVE_CONFIG_H
-#include "config.h"
-#endif
+/* \summary: IPv6 printer */
-#ifdef INET6
+#include <config.h>
-#include <tcpdump-stdinc.h>
+#include "netdissect-stdinc.h"
-#include <stdio.h>
-#include <stdlib.h>
#include <string.h>
#include "netdissect.h"
-#include "interface.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, nd_ipv6 *dst,
+ const struct ip6_hdr *ip6)
+{
+ const u_char *cp;
+ u_int advance;
+ u_int nh;
+ const void *dst_addr;
+ const struct ip6_rthdr *dp;
+ const struct ip6_rthdr0 *dp0;
+ const struct ip6_srh *srh;
+ const u_char *p;
+ int i, len;
+
+ cp = (const u_char *)ip6;
+ advance = sizeof(struct ip6_hdr);
+ nh = GET_U_1(ip6->ip6_nxt);
+ dst_addr = (const void *)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.
+ */
+ advance = (GET_U_1(cp + 1) + 1) << 3;
+ nh = GET_U_1(cp);
+ break;
+
+ case IPPROTO_FRAGMENT:
+ /*
+ * The byte following the next header byte is
+ * marked as reserved, and the header is always
+ * the same size.
+ */
+ advance = sizeof(struct ip6_frag);
+ nh = GET_U_1(cp);
+ break;
+
+ case IPPROTO_ROUTING:
+ /*
+ * OK, we found it.
+ */
+ dp = (const struct ip6_rthdr *)cp;
+ ND_TCHECK_SIZE(dp);
+ len = GET_U_1(dp->ip6r_len);
+ switch (GET_U_1(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;
+ p = (const u_char *) dp0->ip6r0_addr;
+ for (i = 0; i < len; i++) {
+ ND_TCHECK_16(p);
+ dst_addr = (const void *)p;
+ p += 16;
+ }
+ break;
+ case IPV6_RTHDR_TYPE_4:
+ /* IPv6 Segment Routing Header (SRH) */
+ srh = (const struct ip6_srh *)dp;
+ if (len % 2 == 1)
+ goto trunc;
+ p = (const u_char *) srh->srh_segments;
+ /*
+ * The list of segments are encoded in the reverse order.
+ * Accordingly, the final DA is encoded in srh_segments[0]
+ */
+ ND_TCHECK_16(p);
+ dst_addr = (const void *)p;
+ 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:
+ GET_CPY_BYTES(dst, dst_addr, sizeof(nd_ipv6));
+}
+
/*
* Compute a V6-style checksum by building a pseudoheader.
*/
-int
-nextproto6_cksum(const struct ip6_hdr *ip6, const u_int8_t *data,
- u_int len, u_int covlen, u_int next_proto)
+uint16_t
+nextproto6_cksum(netdissect_options *ndo,
+ const struct ip6_hdr *ip6, const uint8_t *data,
+ u_int len, u_int covlen, uint8_t next_proto)
{
struct {
- struct in6_addr ph_src;
- struct in6_addr ph_dst;
- u_int32_t ph_len;
- u_int8_t ph_zero[3];
- u_int8_t ph_nxt;
+ nd_ipv6 ph_src;
+ nd_ipv6 ph_dst;
+ uint32_t ph_len;
+ uint8_t ph_zero[3];
+ uint8_t ph_nxt;
} ph;
struct cksum_vec vec[2];
+ u_int nh;
/* pseudo-header */
memset(&ph, 0, sizeof(ph));
- UNALIGNED_MEMCPY(&ph.ph_src, &ip6->ip6_src, sizeof (struct in6_addr));
- UNALIGNED_MEMCPY(&ph.ph_dst, &ip6->ip6_dst, sizeof (struct in6_addr));
+ GET_CPY_BYTES(&ph.ph_src, ip6->ip6_src, sizeof(nd_ipv6));
+ nh = GET_U_1(ip6->ip6_nxt);
+ switch (nh) {
+
+ 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:
+ GET_CPY_BYTES(&ph.ph_dst, ip6->ip6_dst, sizeof(nd_ipv6));
+ break;
+ }
ph.ph_len = htonl(len);
ph.ph_nxt = next_proto;
- vec[0].ptr = (const u_int8_t *)(void *)&ph;
+ vec[0].ptr = (const uint8_t *)(void *)&ph;
vec[0].len = sizeof(ph);
vec[1].ptr = data;
vec[1].len = covlen;
void
ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
{
- register const struct ip6_hdr *ip6;
- register int advance;
+ const struct ip6_hdr *ip6;
+ int advance;
u_int len;
- const u_char *ipend;
- register const u_char *cp;
- register u_int payload_len;
- int nh;
+ u_int total_advance;
+ const u_char *cp;
+ uint32_t payload_len;
+ uint8_t ph, nh;
int fragmented = 0;
u_int flow;
+ int found_extension_header;
+ int found_jumbo;
+ int found_hbh;
+ ndo->ndo_protocol = "ip6";
ip6 = (const struct ip6_hdr *)bp;
- TCHECK(*ip6);
- if (length < sizeof (struct ip6_hdr)) {
- (void)ND_PRINT((ndo, "truncated-ip6 %u", length));
- return;
+ if (!ndo->ndo_eflag) {
+ nd_print_protocol_caps(ndo);
+ ND_PRINT(" ");
}
- if (!ndo->ndo_eflag)
- ND_PRINT((ndo, "IP6 "));
+ ND_ICHECK_ZU(length, <, sizeof (struct ip6_hdr));
+ ND_ICHECKMSG_U("version", IP6_VERSION(ip6), !=, 6);
- if (IP6_VERSION(ip6) != 6) {
- ND_PRINT((ndo,"version error: %u != 6", IP6_VERSION(ip6)));
- return;
+ payload_len = GET_BE_U_2(ip6->ip6_plen);
+ /*
+ * RFC 1883 says:
+ *
+ * The Payload Length field in the IPv6 header must be set to zero
+ * in every packet that carries the Jumbo Payload option. If a
+ * packet is received with a valid Jumbo Payload option present and
+ * a non-zero IPv6 Payload Length field, an ICMP Parameter Problem
+ * message, Code 0, should be sent to the packet's source, pointing
+ * to the Option Type field of the Jumbo Payload option.
+ *
+ * Later versions of the IPv6 spec don't discuss the Jumbo Payload
+ * option.
+ *
+ * If the payload length is 0, we temporarily just set the total
+ * length to the remaining data in the packet (which, for Ethernet,
+ * could include frame padding, but if it's a Jumbo Payload frame,
+ * it shouldn't even be sendable over Ethernet, so we don't worry
+ * about that), so we can process the extension headers in order
+ * to *find* a Jumbo Payload hop-by-hop option and, when we've
+ * processed all the extension headers, check whether we found
+ * a Jumbo Payload option, and fail if we haven't.
+ */
+ if (payload_len != 0) {
+ len = payload_len + sizeof(struct ip6_hdr);
+ if (len > length) {
+ ND_PRINT("[header+payload length %u > length %u]",
+ len, length);
+ nd_print_invalid(ndo);
+ ND_PRINT(" ");
+ }
+ } else
+ len = length + sizeof(struct ip6_hdr);
+
+ ph = 255;
+ nh = GET_U_1(ip6->ip6_nxt);
+ if (ndo->ndo_vflag) {
+ flow = GET_BE_U_4(ip6->ip6_flow);
+ ND_PRINT("(");
+ /* RFC 2460 */
+ if (flow & 0x0ff00000)
+ ND_PRINT("class 0x%02x, ", (flow & 0x0ff00000) >> 20);
+ if (flow & 0x000fffff)
+ ND_PRINT("flowlabel 0x%05x, ", flow & 0x000fffff);
+
+ ND_PRINT("hlim %u, next-header %s (%u), payload length %u) ",
+ GET_U_1(ip6->ip6_hlim),
+ tok2str(ipproto_values,"unknown",nh),
+ nh,
+ payload_len);
}
-
- payload_len = EXTRACT_16BITS(&ip6->ip6_plen);
- len = payload_len + sizeof(struct ip6_hdr);
- if (length < len)
- (void)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)
- (void)ND_PRINT((ndo, "pri 0x%02x, ", (flow & 0x0f000000) >> 24));
- if (flow & 0x00ffffff)
- (void)ND_PRINT((ndo, "flowlabel 0x%06x, ", flow & 0x00ffffff));
-#else
- /* RFC 2460 */
- if (flow & 0x0ff00000)
- (void)ND_PRINT((ndo, "class 0x%02x, ", (flow & 0x0ff00000) >> 20));
- if (flow & 0x000fffff)
- (void)ND_PRINT((ndo, "flowlabel 0x%05x, ", flow & 0x000fffff));
-#endif
-
- (void)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));
- }
+ ND_TCHECK_SIZE(ip6);
/*
- * Cut off the snapshot length to the end of the IP payload.
+ * Cut off the snapshot length to the end of the IP payload
+ * or the end of the data in which it's contained, whichever
+ * comes first.
*/
- ipend = bp + len;
- if (ipend < ndo->ndo_snapend)
- ndo->ndo_snapend = ipend;
+ if (!nd_push_snaplen(ndo, bp, ND_MIN(length, len))) {
+ (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC,
+ "%s: can't push snaplen on buffer stack", __func__);
+ }
cp = (const u_char *)ip6;
advance = sizeof(struct ip6_hdr);
- nh = ip6->ip6_nxt;
+ total_advance = 0;
+ /* Process extension headers */
+ found_extension_header = 0;
+ found_jumbo = 0;
+ found_hbh = 0;
while (cp < ndo->ndo_snapend && advance > 0) {
+ if (len < (u_int)advance)
+ goto trunc;
cp += advance;
len -= advance;
+ total_advance += advance;
if (cp == (const u_char *)(ip6 + 1) &&
nh != IPPROTO_TCP && nh != IPPROTO_UDP &&
nh != IPPROTO_DCCP && nh != IPPROTO_SCTP) {
- (void)ND_PRINT((ndo, "%s > %s: ", ip6addr_string(&ip6->ip6_src),
- ip6addr_string(&ip6->ip6_dst)));
+ ND_PRINT("%s > %s: ", GET_IP6ADDR_STRING(ip6->ip6_src),
+ GET_IP6ADDR_STRING(ip6->ip6_dst));
}
switch (nh) {
+
case IPPROTO_HOPOPTS:
- advance = hbhopt_print(cp);
- nh = *cp;
+ /*
+ * The Hop-by-Hop Options header, when present,
+ * must immediately follow the IPv6 header (RFC 8200)
+ */
+ if (found_hbh == 1) {
+ ND_PRINT("[The Hop-by-Hop Options header was already found]");
+ nd_print_invalid(ndo);
+ return;
+ }
+ if (ph != 255) {
+ ND_PRINT("[The Hop-by-Hop Options header don't follow the IPv6 header]");
+ nd_print_invalid(ndo);
+ return;
+ }
+ advance = hbhopt_process(ndo, cp, &found_jumbo, &payload_len);
+ if (payload_len == 0 && found_jumbo == 0) {
+ ND_PRINT("[No valid Jumbo Payload Hop-by-Hop option found]");
+ nd_print_invalid(ndo);
+ return;
+ }
+ if (advance < 0) {
+ nd_pop_packet_info(ndo);
+ return;
+ }
+ found_extension_header = 1;
+ found_hbh = 1;
+ nh = GET_U_1(cp);
break;
+
case IPPROTO_DSTOPTS:
- advance = dstopt_print(cp);
- nh = *cp;
+ advance = dstopt_process(ndo, cp);
+ if (advance < 0) {
+ nd_pop_packet_info(ndo);
+ return;
+ }
+ found_extension_header = 1;
+ nh = GET_U_1(cp);
break;
+
case IPPROTO_FRAGMENT:
advance = frag6_print(ndo, cp, (const u_char *)ip6);
- if (ndo->ndo_snapend <= cp + advance)
+ if (advance < 0 || ndo->ndo_snapend <= cp + advance) {
+ nd_pop_packet_info(ndo);
return;
- nh = *cp;
+ }
+ found_extension_header = 1;
+ nh = GET_U_1(cp);
fragmented = 1;
break;
case IPPROTO_MOBILITY_OLD:
case IPPROTO_MOBILITY:
/*
- * XXX - we don't use "advance"; the current
- * "Mobility Support in IPv6" draft
- * (draft-ietf-mobileip-ipv6-24) says that
+ * 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
+ * the possibility of a future extension in
* which payload can be piggybacked atop a
* mobility header.
*/
- advance = mobility_print(cp, (const u_char *)ip6);
- nh = *cp;
+ advance = mobility_print(ndo, cp, (const u_char *)ip6);
+ if (advance < 0) {
+ nd_pop_packet_info(ndo);
+ return;
+ }
+ found_extension_header = 1;
+ nh = GET_U_1(cp);
+ nd_pop_packet_info(ndo);
return;
+
case IPPROTO_ROUTING:
- advance = rt6_print(cp, (const u_char *)ip6);
- nh = *cp;
- break;
- case IPPROTO_SCTP:
- sctp_print(cp, (const u_char *)ip6, len);
- return;
- case IPPROTO_DCCP:
- dccp_print(cp, (const u_char *)ip6, len);
- return;
- case IPPROTO_TCP:
- tcp_print(cp, len, (const u_char *)ip6, fragmented);
- return;
- case IPPROTO_UDP:
- udp_print(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(gndo, cp);
- nh = *cp;
- break;
- case IPPROTO_ESP:
- {
- int enh, padlen;
- advance = esp_print(ndo, cp, len, (const u_char *)ip6, &enh, &padlen);
- nh = enh & 0xff;
- len -= padlen;
- break;
- }
- case IPPROTO_IPCOMP:
- {
- int enh;
- advance = ipcomp_print(ndo, cp, &enh);
- nh = enh & 0xff;
+ ND_TCHECK_1(cp);
+ advance = rt6_print(ndo, cp, (const u_char *)ip6);
+ if (advance < 0) {
+ nd_pop_packet_info(ndo);
+ return;
+ }
+ found_extension_header = 1;
+ nh = GET_U_1(cp);
break;
- }
-
- case IPPROTO_PIM:
- pim_print(cp, len, nextproto6_cksum(ip6, cp, len, len,
- IPPROTO_PIM));
- return;
-
- case IPPROTO_OSPF:
- ospf6_print(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(cp, len, (const u_char *)ip6);
- return;
-
- case IPPROTO_GRE:
- gre_print(ndo, cp, len);
- return;
-
- case IPPROTO_RSVP:
- rsvp_print(cp, len);
- return;
-
- case IPPROTO_NONE:
- (void)ND_PRINT((ndo, "no next header"));
- return;
default:
- (void)ND_PRINT((ndo, "ip-proto-%d %d", nh, len));
+ /*
+ * Not an extension header; hand off to the
+ * IP protocol demuxer.
+ */
+ if (found_jumbo) {
+ /*
+ * We saw a Jumbo Payload option.
+ * Set the length to the payload length
+ * plus the IPv6 header length, and
+ * change the snapshot length accordingly.
+ *
+ * But make sure it's not shorter than
+ * the total number of bytes we've
+ * processed so far.
+ */
+ len = payload_len + sizeof(struct ip6_hdr);
+ if (len < total_advance)
+ goto trunc;
+ if (len > length) {
+ ND_PRINT("[header+payload length %u > length %u]",
+ len, length);
+ nd_print_invalid(ndo);
+ ND_PRINT(" ");
+ }
+ nd_change_snaplen(ndo, bp, len);
+
+ /*
+ * Now subtract the length of the IPv6
+ * header plus extension headers to get
+ * the payload length.
+ */
+ len -= total_advance;
+ } else {
+ /*
+ * We didn't see a Jumbo Payload option;
+ * was the payload length zero?
+ */
+ if (payload_len == 0) {
+ /*
+ * Yes. If we found an extension
+ * header, treat that as a truncated
+ * packet header, as there was
+ * no payload to contain an
+ * extension header.
+ */
+ if (found_extension_header)
+ goto trunc;
+
+ /*
+ * OK, we didn't see any extension
+ * header, but that means we have
+ * no payload, so set the length
+ * to the IPv6 header length,
+ * and change the snapshot length
+ * accordingly.
+ */
+ len = sizeof(struct ip6_hdr);
+ nd_change_snaplen(ndo, bp, len);
+
+ /*
+ * Now subtract the length of
+ * the IPv6 header plus extension
+ * headers (there weren't any, so
+ * that's just the IPv6 header
+ * length) to get the payload length.
+ */
+ len -= total_advance;
+ }
+ }
+ ip_demux_print(ndo, cp, len, 6, fragmented,
+ GET_U_1(ip6->ip6_hlim), nh, bp);
+ nd_pop_packet_info(ndo);
return;
}
+ ph = nh;
+
+ /* ndo_protocol reassignment after xxx_print() calls */
+ ndo->ndo_protocol = "ip6";
}
+ nd_pop_packet_info(ndo);
return;
trunc:
- (void)ND_PRINT((ndo, "[|ip6]"));
-}
+ nd_print_trunc(ndo);
+ return;
-#endif /* INET6 */
+invalid:
+ nd_print_invalid(ndo);
+}
projects / tcpdump / blobdiff