X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/ce1fc8263da72437c1df54b8b3ee682413d9e6ed..c0af6af3011d4c55bdadf3dd76cd5fc1115c50d0:/print-ip6.c

diff --git a/print-ip6.c b/print-ip6.c
index d3fe53a6..faffb4a2 100644
--- a/print-ip6.c
+++ b/print-ip6.c
@@ -19,48 +19,188 @@
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  */
 
+/* \summary: IPv6 printer */
+
 #ifdef HAVE_CONFIG_H
-#include "config.h"
+#include <config.h>
 #endif
 
-#ifdef INET6
-
-#include <tcpdump-stdinc.h>
+#include "netdissect-stdinc.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, struct in6_addr *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 u_char *p;
+	int i, len;
+
+	cp = (const u_char *)ip6;
+	advance = sizeof(struct ip6_hdr);
+	nh = EXTRACT_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.
+			 */
+			ND_TCHECK_2(cp);
+			advance = (EXTRACT_U_1(cp + 1) + 1) << 3;
+			nh = EXTRACT_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.
+			 */
+			ND_TCHECK_1(cp);
+			advance = sizeof(struct ip6_frag);
+			nh = EXTRACT_U_1(cp);
+			break;
+
+		case IPPROTO_ROUTING:
+			/*
+			 * OK, we found it.
+			 */
+			dp = (const struct ip6_rthdr *)cp;
+			ND_TCHECK_SIZE(dp);
+			len = EXTRACT_U_1(dp->ip6r_len);
+			switch (EXTRACT_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;
+
+			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(nd_ipv6));
+}
+
 /*
  * Compute a V6-style checksum by building a pseudoheader.
  */
-int
-nextproto6_cksum(const struct ip6_hdr *ip6, const u_int8_t *data,
+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)
 {
         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;
+                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));
+        UNALIGNED_MEMCPY(&ph.ph_src, ip6->ip6_src, sizeof (struct in6_addr));
+        nh = EXTRACT_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:
+                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 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;
@@ -74,60 +214,62 @@ nextproto6_cksum(const struct ip6_hdr *ip6, const u_int8_t *data,
 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;
+	const u_char *cp;
+	u_int payload_len;
+	u_int nh;
 	int fragmented = 0;
 	u_int flow;
 
+	ndo->ndo_protocol = "ip6";
 	ip6 = (const struct ip6_hdr *)bp;
 
-	TCHECK(*ip6);
+	ND_TCHECK_SIZE(ip6);
 	if (length < sizeof (struct ip6_hdr)) {
-		(void)ND_PRINT((ndo, "truncated-ip6 %u", length));
+		ND_PRINT("truncated-ip6 %u", length);
 		return;
 	}
 
         if (!ndo->ndo_eflag)
-            ND_PRINT((ndo, "IP6 "));
+            ND_PRINT("IP6 ");
 
 	if (IP6_VERSION(ip6) != 6) {
-          ND_PRINT((ndo,"version error: %u != 6", IP6_VERSION(ip6)));
+          ND_PRINT("version error: %u != 6", IP6_VERSION(ip6));
           return;
 	}
 
-	payload_len = EXTRACT_16BITS(&ip6->ip6_plen);
+	payload_len = EXTRACT_BE_U_2(ip6->ip6_plen);
 	len = payload_len + sizeof(struct ip6_hdr);
 	if (length < len)
-		(void)ND_PRINT((ndo, "truncated-ip6 - %u bytes missing!",
-			len - length));
+		ND_PRINT("truncated-ip6 - %u bytes missing!",
+			len - length);
 
+        nh = EXTRACT_U_1(ip6->ip6_nxt);
         if (ndo->ndo_vflag) {
-            flow = EXTRACT_32BITS(&ip6->ip6_flow);
-            ND_PRINT((ndo, "("));
+            flow = EXTRACT_BE_U_4(ip6->ip6_flow);
+            ND_PRINT("(");
 #if 0
             /* rfc1883 */
             if (flow & 0x0f000000)
-		(void)ND_PRINT((ndo, "pri 0x%02x, ", (flow & 0x0f000000) >> 24));
+		ND_PRINT("pri 0x%02x, ", (flow & 0x0f000000) >> 24);
             if (flow & 0x00ffffff)
-		(void)ND_PRINT((ndo, "flowlabel 0x%06x, ", flow & 0x00ffffff));
+		ND_PRINT("flowlabel 0x%06x, ", flow & 0x00ffffff);
 #else
             /* RFC 2460 */
             if (flow & 0x0ff00000)
-		(void)ND_PRINT((ndo, "class 0x%02x, ", (flow & 0x0ff00000) >> 20));
+		ND_PRINT("class 0x%02x, ", (flow & 0x0ff00000) >> 20);
             if (flow & 0x000fffff)
-		(void)ND_PRINT((ndo, "flowlabel 0x%05x, ", flow & 0x000fffff));
+		ND_PRINT("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_PRINT("hlim %u, next-header %s (%u) payload length: %u) ",
+                         EXTRACT_U_1(ip6->ip6_hlim),
+                         tok2str(ipproto_values,"unknown",nh),
+                         nh,
+                         payload_len);
         }
 
 	/*
@@ -139,96 +281,112 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
 
 	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) {
-			(void)ND_PRINT((ndo, "%s > %s: ", ip6addr_string(&ip6->ip6_src),
-				     ip6addr_string(&ip6->ip6_dst)));
+			ND_PRINT("%s > %s: ", ip6addr_string(ndo, ip6->ip6_src),
+				     ip6addr_string(ndo, ip6->ip6_dst));
 		}
 
 		switch (nh) {
 		case IPPROTO_HOPOPTS:
-			advance = hbhopt_print(cp);
-			nh = *cp;
+			advance = hbhopt_print(ndo, cp);
+			if (advance < 0)
+				return;
+			nh = EXTRACT_U_1(cp);
 			break;
 		case IPPROTO_DSTOPTS:
-			advance = dstopt_print(cp);
-			nh = *cp;
+			advance = dstopt_print(ndo, cp);
+			if (advance < 0)
+				return;
+			nh = EXTRACT_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)
 				return;
-			nh = *cp;
+			nh = EXTRACT_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
+			 * 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(cp, (const u_char *)ip6);
-			nh = *cp;
+			advance = mobility_print(ndo, cp, (const u_char *)ip6);
+			if (advance < 0)
+				return;
+			nh = EXTRACT_U_1(cp);
 			return;
 		case IPPROTO_ROUTING:
+			ND_TCHECK_1(cp);
 			advance = rt6_print(ndo, cp, (const u_char *)ip6);
-			nh = *cp;
+			if (advance < 0)
+				return;
+			nh = EXTRACT_U_1(cp);
 			break;
 		case IPPROTO_SCTP:
-			sctp_print(cp, (const u_char *)ip6, len);
+			sctp_print(ndo, cp, (const u_char *)ip6, len);
 			return;
 		case IPPROTO_DCCP:
-			dccp_print(cp, (const u_char *)ip6, len);
+			dccp_print(ndo, cp, (const u_char *)ip6, len);
 			return;
 		case IPPROTO_TCP:
-			tcp_print(cp, len, (const u_char *)ip6, fragmented);
+			tcp_print(ndo, cp, len, (const u_char *)ip6, fragmented);
 			return;
 		case IPPROTO_UDP:
-			udp_print(cp, len, (const u_char *)ip6, fragmented);
+			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(gndo, cp);
-			nh = *cp;
+			advance = ah_print(ndo, cp);
+			if (advance < 0)
+				return;
+			nh = EXTRACT_U_1(cp);
 			break;
 		case IPPROTO_ESP:
 		    {
-			int enh, padlen;
+			u_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:
 		    {
-			int enh;
-			advance = ipcomp_print(ndo, cp, &enh);
-			nh = enh & 0xff;
+			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(cp, len, nextproto6_cksum(ip6, cp, len, len,
-							    IPPROTO_PIM));
+			pim_print(ndo, cp, len, (const u_char *)ip6);
 			return;
 
 		case IPPROTO_OSPF:
-			ospf6_print(cp, len);
+			ospf6_print(ndo, cp, len);
 			return;
 
 		case IPPROTO_IPV6:
@@ -240,7 +398,7 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
 			return;
 
                 case IPPROTO_PGM:
-                        pgm_print(cp, len, (const u_char *)ip6);
+                        pgm_print(ndo, cp, len, (const u_char *)ip6);
                         return;
 
 		case IPPROTO_GRE:
@@ -248,22 +406,27 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
 			return;
 
 		case IPPROTO_RSVP:
-			rsvp_print(cp, len);
+			rsvp_print(ndo, cp, len);
+			return;
+
+		case IPPROTO_EIGRP:
+			eigrp_print(ndo, cp, len);
 			return;
 
 		case IPPROTO_NONE:
-			(void)ND_PRINT((ndo, "no next header"));
+			ND_PRINT("no next header");
 			return;
 
 		default:
-			(void)ND_PRINT((ndo, "ip-proto-%d %d", nh, len));
+			ND_PRINT("ip-proto-%u %u", nh, len);
 			return;
 		}
+
+		/* ndo_protocol reassignment after xxx_print() calls */
+		ndo->ndo_protocol = "ip6";
 	}
 
 	return;
 trunc:
-	(void)ND_PRINT((ndo, "[|ip6]"));
+	nd_print_trunc(ndo);
 }
-
-#endif /* INET6 */