xref: /openbsd-src/usr.sbin/tcpdump/print-etherip.c (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1 /*	$OpenBSD: print-etherip.c,v 1.5 2007/10/07 16:41:05 deraadt Exp $	*/
2 
3 /*
4  * Copyright (c) 2001 Jason L. Wright (jason@thought.net)
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
24  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
25  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * Format and print etherip packets
31  */
32 
33 #ifndef lint
34 static const char rcsid[] =
35     "@(#) $Id: print-etherip.c,v 1.5 2007/10/07 16:41:05 deraadt Exp $";
36 #endif
37 
38 #include <sys/param.h>
39 #include <sys/time.h>
40 #include <sys/socket.h>
41 
42 #include <net/if.h>
43 #include <netinet/in.h>
44 #include <netinet/in_systm.h>
45 #include <netinet/ip.h>
46 #include <netinet/ip_var.h>
47 #include <netinet/udp.h>
48 #include <netinet/udp_var.h>
49 #include <netinet/tcp.h>
50 #include <netinet/tcpip.h>
51 #include <netinet/if_ether.h>
52 #include <netinet/ip_ether.h>
53 
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <unistd.h>
58 #include <stddef.h>
59 
60 #include "addrtoname.h"
61 #include "interface.h"
62 #include "extract.h"		    /* must come after interface.h */
63 
64 extern u_short extracted_ethertype;
65 
66 void
67 etherip_print(const u_char *bp, u_int caplen, u_int len, const u_char *bp2)
68 {
69 	const struct ip *ip = (const struct ip *)bp2;
70 	struct ether_header *eh;
71 	const u_char *pbuf = bp;
72 	u_int plen = caplen, hlen;
73 	u_int16_t etype;
74 
75 	if (plen < sizeof(struct etherip_header)) {
76 		printf("[|etherip]");
77 		return;
78 	}
79 
80 	printf("etherip %s > %s ver ", ipaddr_string(&ip->ip_src),
81 	    ipaddr_string(&ip->ip_dst));
82 
83 	switch ((*pbuf) & 0xf) {
84 	case 2:
85 		hlen = 1;
86 		printf("%d", 2);
87 		break;
88 	case 3:
89 		hlen = 2;
90 		printf("%d", 3);
91 		break;
92 	default:
93 		hlen = 0;
94 		printf("unknown");
95 		break;
96 	}
97 	printf(" len %d", len);
98 	if (hlen == 0)
99 		return;
100 
101 	printf(": ");
102 
103 	if (plen < hlen) {
104 		printf("[|etherip]");
105 		return;
106 	}
107 	pbuf += hlen;
108 	plen -= hlen;
109 	len -= hlen;
110 
111 	if (eflag)
112 		ether_print(pbuf, len);
113 	eh = (struct ether_header *)pbuf;
114 	if (plen < sizeof(struct ether_header)) {
115 		printf("[|ether]");
116 		return;
117 	}
118 	etype = EXTRACT_16BITS(pbuf + offsetof(struct ether_header, ether_type));
119 	pbuf += sizeof(struct ether_header);
120 	plen -= sizeof(struct ether_header);
121 	len -= sizeof(struct ether_header);
122 
123 	/* XXX LLC? */
124 	extracted_ethertype = 0;
125 	if (etype <= ETHERMTU) {
126 		if (llc_print(pbuf, len, plen, ESRC(eh), EDST(eh)) == 0) {
127 			if (!eflag)
128 				ether_print((u_char *)eh, len);
129 			if (extracted_ethertype) {
130 				printf("LLC %s",
131 				    etherproto_string(htons(extracted_ethertype)));
132 			}
133 			if (!xflag && !qflag)
134 				default_print(pbuf, plen);
135 		}
136 	} else if (ether_encap_print(etype, pbuf, len, plen) == 0) {
137 		if (!eflag)
138 			ether_print((u_char *)eh, len + sizeof(*eh));
139 		if (!xflag && !qflag)
140 			default_print(pbuf, plen);
141 	}
142 }
143