print-pppoe.c revision e66460324c0c1d5b6f767afeb6f3d201094156d3
1/*
2 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that: (1) source code distributions
7 * retain the above copyright notice and this paragraph in its entirety, (2)
8 * distributions including binary code include the above copyright notice and
9 * this paragraph in its entirety in the documentation or other materials
10 * provided with the distribution, and (3) all advertising materials mentioning
11 * features or use of this software display the following acknowledgement:
12 * ``This product includes software developed by the University of California,
13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14 * the University nor the names of its contributors may be used to endorse
15 * or promote products derived from this software without specific prior
16 * written permission.
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20 *
21 * Original code by Greg Stark <gsstark@mit.edu>
22 */
23
24#ifndef lint
25static const char rcsid[] _U_ =
26"@(#) $Header: /tcpdump/master/tcpdump/print-pppoe.c,v 1.30.2.1 2005/04/26 19:48:56 guy Exp $ (LBL)";
27#endif
28
29#ifdef HAVE_CONFIG_H
30#include "config.h"
31#endif
32
33#include <tcpdump-stdinc.h>
34
35#include <stdio.h>
36#include <string.h>
37
38#include "interface.h"
39#include "addrtoname.h"
40#include "ppp.h"
41#include "ethertype.h"
42#include "ether.h"
43#include "extract.h"			/* must come after interface.h */
44
45/* Codes */
46enum {
47	PPPOE_PADI = 0x09,
48	PPPOE_PADO = 0x07,
49	PPPOE_PADR = 0x19,
50	PPPOE_PADS = 0x65,
51	PPPOE_PADT = 0xa7
52};
53
54static struct tok pppoecode2str[] = {
55	{ PPPOE_PADI, "PADI" },
56	{ PPPOE_PADO, "PADO" },
57	{ PPPOE_PADR, "PADR" },
58	{ PPPOE_PADS, "PADS" },
59	{ PPPOE_PADT, "PADT" },
60	{ 0, "" }, /* PPP Data */
61	{ 0, NULL }
62};
63
64/* Tags */
65enum {
66	PPPOE_EOL = 0,
67	PPPOE_SERVICE_NAME = 0x0101,
68	PPPOE_AC_NAME = 0x0102,
69	PPPOE_HOST_UNIQ = 0x0103,
70	PPPOE_AC_COOKIE = 0x0104,
71	PPPOE_VENDOR = 0x0105,
72	PPPOE_RELAY_SID = 0x0110,
73	PPPOE_SERVICE_NAME_ERROR = 0x0201,
74	PPPOE_AC_SYSTEM_ERROR = 0x0202,
75	PPPOE_GENERIC_ERROR = 0x0203
76};
77
78static struct tok pppoetag2str[] = {
79	{ PPPOE_EOL, "EOL" },
80	{ PPPOE_SERVICE_NAME, "Service-Name" },
81	{ PPPOE_AC_NAME, "AC-Name" },
82	{ PPPOE_HOST_UNIQ, "Host-Uniq" },
83	{ PPPOE_AC_COOKIE, "AC-Cookie" },
84	{ PPPOE_VENDOR, "Vendor-Specific" },
85	{ PPPOE_RELAY_SID, "Relay-Session-ID" },
86	{ PPPOE_SERVICE_NAME_ERROR, "Service-Name-Error" },
87	{ PPPOE_AC_SYSTEM_ERROR, "AC-System-Error" },
88	{ PPPOE_GENERIC_ERROR, "Generic-Error" },
89	{ 0, NULL }
90};
91
92#define PPPOE_HDRLEN 6
93#define MAXTAGPRINT 80
94
95u_int
96pppoe_if_print(const struct pcap_pkthdr *h, register const u_char *p)
97{
98	return (pppoe_print(p, h->len));
99}
100
101u_int
102pppoe_print(register const u_char *bp, u_int length)
103{
104	u_int16_t pppoe_ver, pppoe_type, pppoe_code, pppoe_sessionid;
105	u_int pppoe_length;
106	const u_char *pppoe_packet, *pppoe_payload;
107
108	if (length < PPPOE_HDRLEN) {
109		(void)printf("truncated-pppoe %u", length);
110		return (length);
111	}
112	length -= PPPOE_HDRLEN;
113	pppoe_packet = bp;
114	TCHECK2(*pppoe_packet, PPPOE_HDRLEN);
115	pppoe_ver  = (pppoe_packet[0] & 0xF0) >> 4;
116	pppoe_type  = (pppoe_packet[0] & 0x0F);
117	pppoe_code = pppoe_packet[1];
118	pppoe_sessionid = EXTRACT_16BITS(pppoe_packet + 2);
119	pppoe_length    = EXTRACT_16BITS(pppoe_packet + 4);
120	pppoe_payload = pppoe_packet + PPPOE_HDRLEN;
121
122	if (pppoe_ver != 1) {
123		printf(" [ver %d]",pppoe_ver);
124	}
125	if (pppoe_type != 1) {
126		printf(" [type %d]",pppoe_type);
127	}
128
129	printf("PPPoE %s", tok2str(pppoecode2str, "PAD-%x", pppoe_code));
130	if (pppoe_code == PPPOE_PADI && pppoe_length > 1484 - PPPOE_HDRLEN) {
131		printf(" [len %u!]",pppoe_length);
132	}
133	if (pppoe_length > length) {
134		printf(" [len %u > %u!]", pppoe_length, length);
135		pppoe_length = length;
136	}
137	if (pppoe_sessionid) {
138		printf(" [ses 0x%x]", pppoe_sessionid);
139	}
140
141	if (pppoe_code) {
142		/* PPP session packets don't contain tags */
143		u_short tag_type = 0xffff, tag_len;
144		const u_char *p = pppoe_payload;
145
146		/*
147		 * loop invariant:
148		 * p points to current tag,
149		 * tag_type is previous tag or 0xffff for first iteration
150		 */
151		while (tag_type && p < pppoe_payload + pppoe_length) {
152			TCHECK2(*p, 4);
153			tag_type = EXTRACT_16BITS(p);
154			tag_len = EXTRACT_16BITS(p + 2);
155			p += 4;
156			/* p points to tag_value */
157
158			if (tag_len) {
159				unsigned isascii = 0, isgarbage = 0;
160				const u_char *v = p;
161				char tag_str[MAXTAGPRINT];
162				unsigned tag_str_len = 0;
163
164				/* TODO print UTF-8 decoded text */
165				TCHECK2(*p, tag_len);
166				for (v = p; v < p + tag_len && tag_str_len < MAXTAGPRINT-1; v++)
167					if (*v >= 32 && *v < 127) {
168						tag_str[tag_str_len++] = *v;
169						isascii++;
170					} else {
171						tag_str[tag_str_len++] = '.';
172						isgarbage++;
173					}
174				tag_str[tag_str_len] = 0;
175
176				if (isascii > isgarbage) {
177					printf(" [%s \"%*.*s\"]",
178					       tok2str(pppoetag2str, "TAG-0x%x", tag_type),
179					       (int)tag_str_len,
180					       (int)tag_str_len,
181					       tag_str);
182				} else {
183					/* Print hex, not fast to abuse printf but this doesn't get used much */
184					printf(" [%s 0x", tok2str(pppoetag2str, "TAG-0x%x", tag_type));
185					for (v=p; v<p+tag_len; v++) {
186						printf("%02X", *v);
187					}
188					printf("]");
189				}
190
191
192			} else
193				printf(" [%s]", tok2str(pppoetag2str,
194				    "TAG-0x%x", tag_type));
195
196			p += tag_len;
197			/* p points to next tag */
198		}
199		return (0);
200	} else {
201		/* PPPoE data */
202		printf(" ");
203		return (PPPOE_HDRLEN + ppp_print(pppoe_payload, pppoe_length));
204	}
205
206trunc:
207	printf("[|pppoe]");
208	return (PPPOE_HDRLEN);
209}
210