/* \summary: IPv6 printer */
-#ifdef HAVE_CONFIG_H
#include <config.h>
-#endif
#include "netdissect-stdinc.h"
* calculation.
*/
static void
-ip6_finddst(netdissect_options *ndo, struct in6_addr *dst,
+ip6_finddst(netdissect_options *ndo, nd_ipv6 *dst,
const struct ip6_hdr *ip6)
{
const u_char *cp;
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;
* the header, in units of 8 octets, excluding
* the first 8 octets.
*/
- ND_TCHECK_2(cp);
advance = (GET_U_1(cp + 1) + 1) << 3;
nh = GET_U_1(cp);
break;
* marked as reserved, and the header is always
* the same size.
*/
- ND_TCHECK_1(cp);
advance = sizeof(struct ip6_frag);
nh = GET_U_1(cp);
break;
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;
done:
trunc:
- UNALIGNED_MEMCPY(dst, dst_addr, sizeof(nd_ipv6));
+ GET_CPY_BYTES(dst, dst_addr, sizeof(nd_ipv6));
}
/*
uint16_t
nextproto6_cksum(netdissect_options *ndo,
const struct ip6_hdr *ip6, const uint8_t *data,
- u_int len, u_int covlen, u_int next_proto)
+ u_int len, u_int covlen, uint8_t next_proto)
{
struct {
- struct in6_addr ph_src;
- struct in6_addr ph_dst;
+ nd_ipv6 ph_src;
+ nd_ipv6 ph_dst;
uint32_t ph_len;
uint8_t ph_zero[3];
uint8_t ph_nxt;
/* pseudo-header */
memset(&ph, 0, sizeof(ph));
- UNALIGNED_MEMCPY(&ph.ph_src, ip6->ip6_src, 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) {
break;
default:
- UNALIGNED_MEMCPY(&ph.ph_dst, ip6->ip6_dst,
- sizeof (struct in6_addr));
+ GET_CPY_BYTES(&ph.ph_dst, ip6->ip6_dst, sizeof(nd_ipv6));
break;
}
ph.ph_len = htonl(len);
const struct ip6_hdr *ip6;
int advance;
u_int len;
- const u_char *ipend;
+ u_int total_advance;
const u_char *cp;
- u_int payload_len;
- u_int nh;
+ 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;
- ND_TCHECK_SIZE(ip6);
- if (length < sizeof (struct ip6_hdr)) {
- ND_PRINT("truncated-ip6 %u", length);
- return;
+ if (!ndo->ndo_eflag) {
+ nd_print_protocol_caps(ndo);
+ ND_PRINT(" ");
}
- if (!ndo->ndo_eflag)
- ND_PRINT("IP6 ");
-
- if (IP6_VERSION(ip6) != 6) {
- ND_PRINT("version error: %u != 6", IP6_VERSION(ip6));
- return;
- }
+ ND_ICHECK_ZU(length, <, sizeof (struct ip6_hdr));
+ ND_ICHECKMSG_U("version", IP6_VERSION(ip6), !=, 6);
payload_len = GET_BE_U_2(ip6->ip6_plen);
- len = payload_len + sizeof(struct ip6_hdr);
- if (length < len)
- ND_PRINT("truncated-ip6 - %u bytes missing!",
- len - length);
+ /*
+ * 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);
- nh = GET_U_1(ip6->ip6_nxt);
- if (ndo->ndo_vflag) {
- flow = GET_BE_U_4(ip6->ip6_flow);
- ND_PRINT("(");
-#if 0
- /* rfc1883 */
- if (flow & 0x0f000000)
- ND_PRINT("pri 0x%02x, ", (flow & 0x0f000000) >> 24);
- if (flow & 0x00ffffff)
- ND_PRINT("flowlabel 0x%06x, ", flow & 0x00ffffff);
-#else
- /* RFC 2460 */
- if (flow & 0x0ff00000)
- ND_PRINT("class 0x%02x, ", (flow & 0x0ff00000) >> 20);
- if (flow & 0x000fffff)
- ND_PRINT("flowlabel 0x%05x, ", flow & 0x000fffff);
-#endif
-
- 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);
- }
+ 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);
+ }
+ 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);
+ 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) {
- ND_PRINT("%s > %s: ", ip6addr_string(ndo, ip6->ip6_src),
- ip6addr_string(ndo, 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(ndo, cp);
- if (advance < 0)
+ /*
+ * 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(ndo, cp);
- if (advance < 0)
+ 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 (advance < 0 || ndo->ndo_snapend <= cp + advance)
+ if (advance < 0 || ndo->ndo_snapend <= cp + advance) {
+ nd_pop_packet_info(ndo);
return;
+ }
+ 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"; RFC 3775 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(ndo, cp, (const u_char *)ip6);
- if (advance < 0)
+ 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:
ND_TCHECK_1(cp);
advance = rt6_print(ndo, cp, (const u_char *)ip6);
- if (advance < 0)
+ if (advance < 0) {
+ nd_pop_packet_info(ndo);
return;
+ }
+ found_extension_header = 1;
nh = GET_U_1(cp);
break;
* Not an extension header; hand off to the
* IP protocol demuxer.
*/
- ip_print_demux(ndo, cp, len, 6, fragmented,
- GET_U_1(ip6->ip6_hlim), nh, bp);
+ 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:
nd_print_trunc(ndo);
+ return;
+
+invalid:
+ nd_print_invalid(ndo);
}
projects / tcpdump / blobdiff