print-pppoe.c revision 1.5
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#include <sys/cdefs.h> 25#ifndef lint 26__RCSID("$NetBSD: print-pppoe.c,v 1.5 2014/11/20 03:05:03 christos Exp $"); 27#endif 28 29#define NETDISSECT_REWORKED 30#ifdef HAVE_CONFIG_H 31#include "config.h" 32#endif 33 34#include <tcpdump-stdinc.h> 35 36#include "interface.h" 37#include "extract.h" /* must come after interface.h */ 38 39/* Codes */ 40enum { 41 PPPOE_PADI = 0x09, 42 PPPOE_PADO = 0x07, 43 PPPOE_PADR = 0x19, 44 PPPOE_PADS = 0x65, 45 PPPOE_PADT = 0xa7 46}; 47 48static const struct tok pppoecode2str[] = { 49 { PPPOE_PADI, "PADI" }, 50 { PPPOE_PADO, "PADO" }, 51 { PPPOE_PADR, "PADR" }, 52 { PPPOE_PADS, "PADS" }, 53 { PPPOE_PADT, "PADT" }, 54 { 0, "" }, /* PPP Data */ 55 { 0, NULL } 56}; 57 58/* Tags */ 59enum { 60 PPPOE_EOL = 0, 61 PPPOE_SERVICE_NAME = 0x0101, 62 PPPOE_AC_NAME = 0x0102, 63 PPPOE_HOST_UNIQ = 0x0103, 64 PPPOE_AC_COOKIE = 0x0104, 65 PPPOE_VENDOR = 0x0105, 66 PPPOE_RELAY_SID = 0x0110, 67 PPPOE_MAX_PAYLOAD = 0x0120, 68 PPPOE_SERVICE_NAME_ERROR = 0x0201, 69 PPPOE_AC_SYSTEM_ERROR = 0x0202, 70 PPPOE_GENERIC_ERROR = 0x0203 71}; 72 73static const struct tok pppoetag2str[] = { 74 { PPPOE_EOL, "EOL" }, 75 { PPPOE_SERVICE_NAME, "Service-Name" }, 76 { PPPOE_AC_NAME, "AC-Name" }, 77 { PPPOE_HOST_UNIQ, "Host-Uniq" }, 78 { PPPOE_AC_COOKIE, "AC-Cookie" }, 79 { PPPOE_VENDOR, "Vendor-Specific" }, 80 { PPPOE_RELAY_SID, "Relay-Session-ID" }, 81 { PPPOE_MAX_PAYLOAD, "PPP-Max-Payload" }, 82 { PPPOE_SERVICE_NAME_ERROR, "Service-Name-Error" }, 83 { PPPOE_AC_SYSTEM_ERROR, "AC-System-Error" }, 84 { PPPOE_GENERIC_ERROR, "Generic-Error" }, 85 { 0, NULL } 86}; 87 88#define PPPOE_HDRLEN 6 89#define MAXTAGPRINT 80 90 91u_int 92pppoe_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, register const u_char *p) 93{ 94 return (pppoe_print(ndo, p, h->len)); 95} 96 97u_int 98pppoe_print(netdissect_options *ndo, register const u_char *bp, u_int length) 99{ 100 uint16_t pppoe_ver, pppoe_type, pppoe_code, pppoe_sessionid; 101 u_int pppoe_length; 102 const u_char *pppoe_packet, *pppoe_payload; 103 104 if (length < PPPOE_HDRLEN) { 105 ND_PRINT((ndo, "truncated-pppoe %u", length)); 106 return (length); 107 } 108 length -= PPPOE_HDRLEN; 109 pppoe_packet = bp; 110 ND_TCHECK2(*pppoe_packet, PPPOE_HDRLEN); 111 pppoe_ver = (pppoe_packet[0] & 0xF0) >> 4; 112 pppoe_type = (pppoe_packet[0] & 0x0F); 113 pppoe_code = pppoe_packet[1]; 114 pppoe_sessionid = EXTRACT_16BITS(pppoe_packet + 2); 115 pppoe_length = EXTRACT_16BITS(pppoe_packet + 4); 116 pppoe_payload = pppoe_packet + PPPOE_HDRLEN; 117 118 if (pppoe_ver != 1) { 119 ND_PRINT((ndo, " [ver %d]",pppoe_ver)); 120 } 121 if (pppoe_type != 1) { 122 ND_PRINT((ndo, " [type %d]",pppoe_type)); 123 } 124 125 ND_PRINT((ndo, "PPPoE %s", tok2str(pppoecode2str, "PAD-%x", pppoe_code))); 126 if (pppoe_code == PPPOE_PADI && pppoe_length > 1484 - PPPOE_HDRLEN) { 127 ND_PRINT((ndo, " [len %u!]",pppoe_length)); 128 } 129 if (pppoe_length > length) { 130 ND_PRINT((ndo, " [len %u > %u!]", pppoe_length, length)); 131 pppoe_length = length; 132 } 133 if (pppoe_sessionid) { 134 ND_PRINT((ndo, " [ses 0x%x]", pppoe_sessionid)); 135 } 136 137 if (pppoe_code) { 138 /* PPP session packets don't contain tags */ 139 u_short tag_type = 0xffff, tag_len; 140 const u_char *p = pppoe_payload; 141 142 /* 143 * loop invariant: 144 * p points to current tag, 145 * tag_type is previous tag or 0xffff for first iteration 146 */ 147 while (tag_type && p < pppoe_payload + pppoe_length) { 148 ND_TCHECK2(*p, 4); 149 tag_type = EXTRACT_16BITS(p); 150 tag_len = EXTRACT_16BITS(p + 2); 151 p += 4; 152 /* p points to tag_value */ 153 154 if (tag_len) { 155 unsigned isascii = 0, isgarbage = 0; 156 const u_char *v; 157 char tag_str[MAXTAGPRINT]; 158 unsigned tag_str_len = 0; 159 160 /* TODO print UTF-8 decoded text */ 161 ND_TCHECK2(*p, tag_len); 162 for (v = p; v < p + tag_len && tag_str_len < MAXTAGPRINT-1; v++) 163 if (*v >= 32 && *v < 127) { 164 tag_str[tag_str_len++] = *v; 165 isascii++; 166 } else { 167 tag_str[tag_str_len++] = '.'; 168 isgarbage++; 169 } 170 tag_str[tag_str_len] = 0; 171 172 if (isascii > isgarbage) { 173 ND_PRINT((ndo, " [%s \"%*.*s\"]", 174 tok2str(pppoetag2str, "TAG-0x%x", tag_type), 175 (int)tag_str_len, 176 (int)tag_str_len, 177 tag_str)); 178 } else { 179 /* Print hex, not fast to abuse printf but this doesn't get used much */ 180 ND_PRINT((ndo, " [%s 0x", tok2str(pppoetag2str, "TAG-0x%x", tag_type))); 181 for (v=p; v<p+tag_len; v++) { 182 ND_PRINT((ndo, "%02X", *v)); 183 } 184 ND_PRINT((ndo, "]")); 185 } 186 187 188 } else 189 ND_PRINT((ndo, " [%s]", tok2str(pppoetag2str, 190 "TAG-0x%x", tag_type))); 191 192 p += tag_len; 193 /* p points to next tag */ 194 } 195 return (0); 196 } else { 197 /* PPPoE data */ 198 ND_PRINT((ndo, " ")); 199 return (PPPOE_HDRLEN + ppp_print(ndo, pppoe_payload, pppoe_length)); 200 } 201 202trunc: 203 ND_PRINT((ndo, "[|pppoe]")); 204 return (PPPOE_HDRLEN); 205} 206