1 files changed, 538 insertions, 0 deletions

diff --git a/print-ip.c b/print-ip.c
new file mode 100644
index 0000000..23ba99c
--- /dev/null
+++ b/print-ip.c
@@ -0,0 +1,538 @@
+/*
+ * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
+ *	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: IP printer */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "netdissect-stdinc.h"
+
+#include "netdissect.h"
+#include "addrtoname.h"
+#include "extract.h"
+
+#include "ip.h"
+#include "ipproto.h"
+
+
+static const struct tok ip_option_values[] = {
+    { IPOPT_EOL, "EOL" },
+    { IPOPT_NOP, "NOP" },
+    { IPOPT_TS, "timestamp" },
+    { IPOPT_SECURITY, "security" },
+    { IPOPT_RR, "RR" },
+    { IPOPT_SSRR, "SSRR" },
+    { IPOPT_LSRR, "LSRR" },
+    { IPOPT_RA, "RA" },
+    { IPOPT_RFC1393, "traceroute" },
+    { 0, NULL }
+};
+
+/*
+ * print the recorded route in an IP RR, LSRR or SSRR option.
+ */
+static int
+ip_printroute(netdissect_options *ndo,
+              const u_char *cp, u_int length)
+{
+	u_int ptr;
+	u_int len;
+
+	if (length < 3) {
+		ND_PRINT(" [bad length %u]", length);
+		return (0);
+	}
+	if ((length + 1) & 3)
+		ND_PRINT(" [bad length %u]", length);
+	ptr = GET_U_1(cp + 2) - 1;
+	if (ptr < 3 || ((ptr + 1) & 3) || ptr > length + 1)
+		ND_PRINT(" [bad ptr %u]", GET_U_1(cp + 2));
+
+	for (len = 3; len < length; len += 4) {
+		ND_TCHECK_4(cp + len);	/* Needed to print the IP addresses */
+		ND_PRINT(" %s", GET_IPADDR_STRING(cp + len));
+		if (ptr > len)
+			ND_PRINT(",");
+	}
+	return (0);
+
+trunc:
+	return (-1);
+}
+
+/*
+ * If source-routing is present and valid, return the final destination.
+ * Otherwise, return IP destination.
+ *
+ * This is used for UDP and TCP pseudo-header in the checksum
+ * calculation.
+ */
+static uint32_t
+ip_finddst(netdissect_options *ndo,
+           const struct ip *ip)
+{
+	u_int length;
+	u_int len;
+	const u_char *cp;
+
+	cp = (const u_char *)(ip + 1);
+	length = IP_HL(ip) * 4;
+	if (length < sizeof(struct ip))
+		goto trunc;
+	length -= sizeof(struct ip);
+
+	for (; length != 0; cp += len, length -= len) {
+		int tt;
+
+		tt = GET_U_1(cp);
+		if (tt == IPOPT_EOL)
+			break;
+		else if (tt == IPOPT_NOP)
+			len = 1;
+		else {
+			len = GET_U_1(cp + 1);
+			if (len < 2)
+				break;
+		}
+		if (length < len)
+			goto trunc;
+		ND_TCHECK_LEN(cp, len);
+		switch (tt) {
+
+		case IPOPT_SSRR:
+		case IPOPT_LSRR:
+			if (len < 7)
+				break;
+			return (GET_IPV4_TO_NETWORK_ORDER(cp + len - 4));
+		}
+	}
+trunc:
+	return (GET_IPV4_TO_NETWORK_ORDER(ip->ip_dst));
+}
+
+/*
+ * Compute a V4-style checksum by building a pseudoheader.
+ */
+uint16_t
+nextproto4_cksum(netdissect_options *ndo,
+                 const struct ip *ip, const uint8_t *data,
+                 u_int len, u_int covlen, uint8_t next_proto)
+{
+	struct phdr {
+		uint32_t src;
+		uint32_t dst;
+		uint8_t mbz;
+		uint8_t proto;
+		uint16_t len;
+	} ph;
+	struct cksum_vec vec[2];
+
+	/* pseudo-header.. */
+	ph.len = htons((uint16_t)len);
+	ph.mbz = 0;
+	ph.proto = next_proto;
+	ph.src = GET_IPV4_TO_NETWORK_ORDER(ip->ip_src);
+	if (IP_HL(ip) == 5)
+		ph.dst = GET_IPV4_TO_NETWORK_ORDER(ip->ip_dst);
+	else
+		ph.dst = ip_finddst(ndo, ip);
+
+	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));
+}
+
+static int
+ip_printts(netdissect_options *ndo,
+           const u_char *cp, u_int length)
+{
+	u_int ptr;
+	u_int len;
+	u_int hoplen;
+	const char *type;
+
+	if (length < 4) {
+		ND_PRINT("[bad length %u]", length);
+		return (0);
+	}
+	ND_PRINT(" TS{");
+	hoplen = ((GET_U_1(cp + 3) & 0xF) != IPOPT_TS_TSONLY) ? 8 : 4;
+	if ((length - 4) & (hoplen-1))
+		ND_PRINT("[bad length %u]", length);
+	ptr = GET_U_1(cp + 2) - 1;
+	len = 0;
+	if (ptr < 4 || ((ptr - 4) & (hoplen-1)) || ptr > length + 1)
+		ND_PRINT("[bad ptr %u]", GET_U_1(cp + 2));
+	switch (GET_U_1(cp + 3)&0xF) {
+	case IPOPT_TS_TSONLY:
+		ND_PRINT("TSONLY");
+		break;
+	case IPOPT_TS_TSANDADDR:
+		ND_PRINT("TS+ADDR");
+		break;
+	case IPOPT_TS_PRESPEC:
+		ND_PRINT("PRESPEC");
+		break;
+	default:
+		ND_PRINT("[bad ts type %u]", GET_U_1(cp + 3)&0xF);
+		goto done;
+	}
+
+	type = " ";
+	for (len = 4; len < length; len += hoplen) {
+		if (ptr == len)
+			type = " ^ ";
+		ND_TCHECK_LEN(cp + len, hoplen);
+		ND_PRINT("%s%u@%s", type, GET_BE_U_4(cp + len + hoplen - 4),
+			  hoplen!=8 ? "" : GET_IPADDR_STRING(cp + len));
+		type = " ";
+	}
+
+done:
+	ND_PRINT("%s", ptr == len ? " ^ " : "");
+
+	if (GET_U_1(cp + 3) >> 4)
+		ND_PRINT(" [%u hops not recorded]} ", GET_U_1(cp + 3)>>4);
+	else
+		ND_PRINT("}");
+	return (0);
+
+trunc:
+	return (-1);
+}
+
+/*
+ * print IP options.
+   If truncated return -1, else 0.
+ */
+static int
+ip_optprint(netdissect_options *ndo,
+            const u_char *cp, u_int length)
+{
+	u_int option_len;
+	const char *sep = "";
+
+	for (; length > 0; cp += option_len, length -= option_len) {
+		u_int option_code;
+
+		ND_PRINT("%s", sep);
+		sep = ",";
+
+		option_code = GET_U_1(cp);
+
+		ND_PRINT("%s",
+		          tok2str(ip_option_values,"unknown %u",option_code));
+
+		if (option_code == IPOPT_NOP ||
+                    option_code == IPOPT_EOL)
+			option_len = 1;
+
+		else {
+			option_len = GET_U_1(cp + 1);
+			if (option_len < 2) {
+				ND_PRINT(" [bad length %u]", option_len);
+				return 0;
+			}
+		}
+
+		if (option_len > length) {
+			ND_PRINT(" [bad length %u]", option_len);
+			return 0;
+		}
+
+		ND_TCHECK_LEN(cp, option_len);
+
+		switch (option_code) {
+		case IPOPT_EOL:
+			return 0;
+
+		case IPOPT_TS:
+			if (ip_printts(ndo, cp, option_len) == -1)
+				goto trunc;
+			break;
+
+		case IPOPT_RR:       /* fall through */
+		case IPOPT_SSRR:
+		case IPOPT_LSRR:
+			if (ip_printroute(ndo, cp, option_len) == -1)
+				goto trunc;
+			break;
+
+		case IPOPT_RA:
+			if (option_len < 4) {
+				ND_PRINT(" [bad length %u]", option_len);
+				break;
+			}
+			ND_TCHECK_1(cp + 3);
+			if (GET_BE_U_2(cp + 2) != 0)
+				ND_PRINT(" value %u", GET_BE_U_2(cp + 2));
+			break;
+
+		case IPOPT_NOP:       /* nothing to print - fall through */
+		case IPOPT_SECURITY:
+		default:
+			break;
+		}
+	}
+	return 0;
+
+trunc:
+	return -1;
+}
+
+#define IP_RES 0x8000
+
+static const struct tok ip_frag_values[] = {
+        { IP_MF,        "+" },
+        { IP_DF,        "DF" },
+	{ IP_RES,       "rsvd" }, /* The RFC3514 evil ;-) bit */
+        { 0,            NULL }
+};
+
+
+/*
+ * print an IP datagram.
+ */
+void
+ip_print(netdissect_options *ndo,
+	 const u_char *bp,
+	 u_int length)
+{
+	const struct ip *ip;
+	u_int off;
+	u_int hlen;
+	u_int len;
+	struct cksum_vec vec[1];
+	uint8_t ip_tos, ip_ttl, ip_proto;
+	uint16_t sum, ip_sum;
+	const char *p_name;
+	int truncated = 0;
+
+	ndo->ndo_protocol = "ip";
+	ip = (const struct ip *)bp;
+	if (IP_V(ip) != 4) { /* print version and fail if != 4 */
+	    if (IP_V(ip) == 6)
+	      ND_PRINT("IP6, wrong link-layer encapsulation");
+	    else
+	      ND_PRINT("IP%u", IP_V(ip));
+	    nd_print_invalid(ndo);
+	    return;
+	}
+	if (!ndo->ndo_eflag)
+		ND_PRINT("IP ");
+
+	ND_TCHECK_SIZE(ip);
+	if (length < sizeof (struct ip)) {
+		ND_PRINT("truncated-ip %u", length);
+		return;
+	}
+	hlen = IP_HL(ip) * 4;
+	if (hlen < sizeof (struct ip)) {
+		ND_PRINT("bad-hlen %u", hlen);
+		return;
+	}
+
+	len = GET_BE_U_2(ip->ip_len);
+	if (length < len)
+		ND_PRINT("truncated-ip - %u bytes missing! ",
+			len - length);
+	if (len < hlen) {
+#ifdef GUESS_TSO
+            if (len) {
+                ND_PRINT("bad-len %u", len);
+                return;
+            }
+            else {
+                /* we guess that it is a TSO send */
+                len = length;
+            }
+#else
+            ND_PRINT("bad-len %u", len);
+            return;
+#endif /* GUESS_TSO */
+	}
+
+	/*
+	 * Cut off the snapshot length to the end of the IP payload.
+	 */
+	if (!nd_push_snaplen(ndo, bp, len)) {
+		(*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC,
+			"%s: can't push snaplen on buffer stack", __func__);
+	}
+
+	len -= hlen;
+
+	off = GET_BE_U_2(ip->ip_off);
+
+        ip_proto = GET_U_1(ip->ip_p);
+
+        if (ndo->ndo_vflag) {
+            ip_tos = GET_U_1(ip->ip_tos);
+            ND_PRINT("(tos 0x%x", ip_tos);
+            /* ECN bits */
+            switch (ip_tos & 0x03) {
+
+            case 0:
+                break;
+
+            case 1:
+                ND_PRINT(",ECT(1)");
+                break;
+
+            case 2:
+                ND_PRINT(",ECT(0)");
+                break;
+
+            case 3:
+                ND_PRINT(",CE");
+                break;
+            }
+
+            ip_ttl = GET_U_1(ip->ip_ttl);
+            if (ip_ttl >= 1)
+                ND_PRINT(", ttl %u", ip_ttl);
+
+	    /*
+	     * for the firewall guys, print id, offset.
+             * On all but the last stick a "+" in the flags portion.
+	     * For unfragmented datagrams, note the don't fragment flag.
+	     */
+	    ND_PRINT(", id %u, offset %u, flags [%s], proto %s (%u)",
+                         GET_BE_U_2(ip->ip_id),
+                         (off & IP_OFFMASK) * 8,
+                         bittok2str(ip_frag_values, "none", off & (IP_RES|IP_DF|IP_MF)),
+                         tok2str(ipproto_values, "unknown", ip_proto),
+                         ip_proto);
+
+            ND_PRINT(", length %u", GET_BE_U_2(ip->ip_len));
+
+            if ((hlen - sizeof(struct ip)) > 0) {
+                ND_PRINT(", options (");
+                if (ip_optprint(ndo, (const u_char *)(ip + 1),
+                    hlen - sizeof(struct ip)) == -1) {
+                        ND_PRINT(" [truncated-option]");
+			truncated = 1;
+                }
+                ND_PRINT(")");
+            }
+
+	    if (!ndo->ndo_Kflag && (const u_char *)ip + hlen <= ndo->ndo_snapend) {
+	        vec[0].ptr = (const uint8_t *)(const void *)ip;
+	        vec[0].len = hlen;
+	        sum = in_cksum(vec, 1);
+		if (sum != 0) {
+		    ip_sum = GET_BE_U_2(ip->ip_sum);
+		    ND_PRINT(", bad cksum %x (->%x)!", ip_sum,
+			     in_cksum_shouldbe(ip_sum, sum));
+		}
+	    }
+
+	    ND_PRINT(")\n    ");
+	    if (truncated) {
+		ND_PRINT("%s > %s: ",
+			 GET_IPADDR_STRING(ip->ip_src),
+			 GET_IPADDR_STRING(ip->ip_dst));
+		nd_print_trunc(ndo);
+		nd_pop_packet_info(ndo);
+		return;
+	    }
+	}
+
+	/*
+	 * If this is fragment zero, hand it to the next higher
+	 * level protocol.  Let them know whether there are more
+	 * fragments.
+	 */
+	if ((off & IP_OFFMASK) == 0) {
+		uint8_t nh = GET_U_1(ip->ip_p);
+
+		if (nh != IPPROTO_TCP && nh != IPPROTO_UDP &&
+		    nh != IPPROTO_SCTP && nh != IPPROTO_DCCP) {
+			ND_PRINT("%s > %s: ",
+				     GET_IPADDR_STRING(ip->ip_src),
+				     GET_IPADDR_STRING(ip->ip_dst));
+		}
+		/*
+		 * Do a bounds check before calling ip_demux_print().
+		 * At least the header data is required.
+		 */
+		if (!ND_TTEST_LEN((const u_char *)ip, hlen)) {
+			ND_PRINT(" [remaining caplen(%u) < header length(%u)]",
+				 ND_BYTES_AVAILABLE_AFTER((const u_char *)ip),
+				 hlen);
+			nd_trunc_longjmp(ndo);
+		}
+		ip_demux_print(ndo, (const u_char *)ip + hlen, len, 4,
+			       off & IP_MF, GET_U_1(ip->ip_ttl), nh, bp);
+	} else {
+		/*
+		 * Ultra quiet now means that all this stuff should be
+		 * suppressed.
+		 */
+		if (ndo->ndo_qflag > 1) {
+			nd_pop_packet_info(ndo);
+			return;
+		}
+
+		/*
+		 * This isn't the first frag, so we're missing the
+		 * next level protocol header.  print the ip addr
+		 * and the protocol.
+		 */
+		ND_PRINT("%s > %s:", GET_IPADDR_STRING(ip->ip_src),
+		          GET_IPADDR_STRING(ip->ip_dst));
+		if (!ndo->ndo_nflag && (p_name = netdb_protoname(ip_proto)) != NULL)
+			ND_PRINT(" %s", p_name);
+		else
+			ND_PRINT(" ip-proto-%u", ip_proto);
+	}
+	nd_pop_packet_info(ndo);
+	return;
+
+trunc:
+	nd_print_trunc(ndo);
+}
+
+void
+ipN_print(netdissect_options *ndo, const u_char *bp, u_int length)
+{
+	ndo->ndo_protocol = "ipn";
+	if (length < 1) {
+		ND_PRINT("truncated-ip %u", length);
+		return;
+	}
+
+	switch (GET_U_1(bp) & 0xF0) {
+	case 0x40:
+		ip_print(ndo, bp, length);
+		break;
+	case 0x60:
+		ip6_print(ndo, bp, length);
+		break;
+	default:
+		ND_PRINT("unknown ip %u", (GET_U_1(bp) & 0xF0) >> 4);
+		break;
+	}
+}