X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/d511b994b9931460771dc56c70b791204178d157..1fb50928ce27360c1c987312774f686b23c69b51:/print-ip6.c

diff --git a/print-ip6.c b/print-ip6.c
index a49705c7..9f590f2a 100644
--- a/print-ip6.c
+++ b/print-ip6.c
@@ -19,35 +19,199 @@
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  */
 
-#ifndef lint
-static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-ip6.c,v 1.39 2003-11-19 06:31:28 guy Exp $";
-#endif
+/* \summary: IPv6 printer */
 
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
-#ifdef INET6
-
-#include <tcpdump-stdinc.h>
+#include <netdissect-stdinc.h>
 
-#include <stdio.h>
-#include <stdlib.h>
 #include <string.h>
 
-#include "interface.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(register const u_char *bp, register u_int length)
+ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
 {
 	register const struct ip6_hdr *ip6;
 	register int advance;
@@ -61,155 +225,188 @@ ip6_print(register const u_char *bp, register u_int length)
 
 	ip6 = (const struct ip6_hdr *)bp;
 
-	TCHECK(*ip6);
+	ND_TCHECK(*ip6);
 	if (length < sizeof (struct ip6_hdr)) {
-		(void)printf("truncated-ip6 %d", length);
+		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)
-		(void)printf("truncated-ip6 - %d bytes missing!",
-			len - length);
+		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 < snapend)
-		snapend = ipend;
+	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 < snapend && advance > 0) {
+	while (cp < ndo->ndo_snapend && advance > 0) {
 		cp += advance;
 		len -= advance;
 
 		if (cp == (const u_char *)(ip6 + 1) &&
 		    nh != IPPROTO_TCP && nh != IPPROTO_UDP &&
-		    nh != IPPROTO_SCTP) {
-			(void)printf("%s > %s: ", ip6addr_string(&ip6->ip6_src),
-				     ip6addr_string(&ip6->ip6_dst));
+		    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(cp);
+			advance = hbhopt_print(ndo, cp);
+			if (advance < 0)
+				return;
 			nh = *cp;
 			break;
 		case IPPROTO_DSTOPTS:
-			advance = dstopt_print(cp);
+			advance = dstopt_print(ndo, cp);
+			if (advance < 0)
+				return;
 			nh = *cp;
 			break;
 		case IPPROTO_FRAGMENT:
-			advance = frag6_print(cp, (const u_char *)ip6);
-			if (snapend <= cp + advance)
-				goto end;
+			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"; is this
-			 * header always a final header?
+			 * 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);
+			advance = mobility_print(ndo, cp, (const u_char *)ip6);
 			nh = *cp;
-			goto end;
+			return;
 		case IPPROTO_ROUTING:
-			advance = rt6_print(cp, (const u_char *)ip6);
+			advance = rt6_print(ndo, cp, (const u_char *)ip6);
 			nh = *cp;
 			break;
 		case IPPROTO_SCTP:
-			sctp_print(cp, (const u_char *)ip6, len);
-			goto end;
+			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(cp, len, (const u_char *)ip6, fragmented);
-			goto end;
+			tcp_print(ndo, cp, len, (const u_char *)ip6, fragmented);
+			return;
 		case IPPROTO_UDP:
-			udp_print(cp, len, (const u_char *)ip6, fragmented);
-			goto end;
+			udp_print(ndo, cp, len, (const u_char *)ip6, fragmented);
+			return;
 		case IPPROTO_ICMPV6:
-			icmp6_print(cp, len, (const u_char *)ip6, fragmented);
-			goto end;
+			icmp6_print(ndo, cp, len, (const u_char *)ip6, fragmented);
+			return;
 		case IPPROTO_AH:
-			advance = ah_print(cp);
+			advance = ah_print(ndo, cp);
 			nh = *cp;
 			break;
 		case IPPROTO_ESP:
 		    {
 			int enh, padlen;
-			advance = esp_print(cp, (const u_char *)ip6, &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(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);
-			goto end;
+			pim_print(ndo, cp, len, (const u_char *)ip6);
+			return;
+
 		case IPPROTO_OSPF:
-			ospf6_print(cp, len);
-			goto end;
+			ospf6_print(ndo, cp, len);
+			return;
 
 		case IPPROTO_IPV6:
-			ip6_print(cp, len);
-			goto end;
+			ip6_print(ndo, cp, len);
+			return;
 
 		case IPPROTO_IPV4:
-			ip_print(cp, len);
-			goto end;
+		        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:
-			(void)printf("no next header");
-			goto end;
+			ND_PRINT((ndo, "no next header"));
+			return;
 
 		default:
-			(void)printf("ip-proto-%d %d", ip6->ip6_nxt, len);
-			goto end;
+			ND_PRINT((ndo, "ip-proto-%d %d", nh, len));
+			return;
 		}
 	}
 
- end:
-
-	flow = EXTRACT_32BITS(&ip6->ip6_flow);
-#if 0
-	/* rfc1883 */
-	if (flow & 0x0f000000)
-		(void)printf(" [pri 0x%x]", (flow & 0x0f000000) >> 24);
-	if (flow & 0x00ffffff)
-		(void)printf(" [flowlabel 0x%x]", flow & 0x00ffffff);
-#else
-	/* RFC 2460 */
-	if (flow & 0x0ff00000)
-		(void)printf(" [class 0x%x]", (flow & 0x0ff00000) >> 20);
-	if (flow & 0x000fffff)
-		(void)printf(" [flowlabel 0x%x]", flow & 0x000fffff);
-#endif
-
-	if (ip6->ip6_hlim <= 1)
-		(void)printf(" [hlim %u]", ip6->ip6_hlim);
-
-	if (vflag) {
-		printf(" (");
-		(void)printf("len %u", payload_len);
-		if (ip6->ip6_hlim > 1)
-			(void)printf(", hlim %d", (int)ip6->ip6_hlim);
-		printf(")");
-	}
 	return;
 trunc:
-	(void)printf("[|ip6]");
+	ND_PRINT((ndo, "[|ip6]"));
 }
-
-#endif /* INET6 */