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 25 static const char rcsid[] _U_ = 26 "@(#) $Header: /tcpdump/master/tcpdump/print-pppoe.c,v 1.24.2.4 2004/03/24 03:04:22 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 */ 46 enum { 47 PPPOE_PADI = 0x09, 48 PPPOE_PADO = 0x07, 49 PPPOE_PADR = 0x19, 50 PPPOE_PADS = 0x65, 51 PPPOE_PADT = 0xa7 52 }; 53 54 static 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 */ 65 enum { 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 78 static 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 95 u_int 96 pppoe_if_print(const struct pcap_pkthdr *h, register const u_char *p) 97 { 98 return (pppoe_print(p, h->len)); 99 } 100 101 u_int 102 pppoe_print(register const u_char *bp, u_int length) 103 { 104 u_short pppoe_ver, pppoe_type, pppoe_code, pppoe_sessionid, pppoe_length; 105 const u_char *pppoe_packet, *pppoe_payload; 106 107 pppoe_packet = bp; 108 TCHECK2(*pppoe_packet, PPPOE_HDRLEN); 109 pppoe_ver = (pppoe_packet[0] & 0xF0) >> 4; 110 pppoe_type = (pppoe_packet[0] & 0x0F); 111 pppoe_code = pppoe_packet[1]; 112 pppoe_sessionid = EXTRACT_16BITS(pppoe_packet + 2); 113 pppoe_length = EXTRACT_16BITS(pppoe_packet + 4); 114 pppoe_payload = pppoe_packet + PPPOE_HDRLEN; 115 116 if (snapend < pppoe_payload) { 117 printf(" truncated PPPoE"); 118 return (PPPOE_HDRLEN); 119 } 120 121 if (pppoe_ver != 1) { 122 printf(" [ver %d]",pppoe_ver); 123 } 124 if (pppoe_type != 1) { 125 printf(" [type %d]",pppoe_type); 126 } 127 128 printf("PPPoE %s", tok2str(pppoecode2str, "PAD-%x", pppoe_code)); 129 if (pppoe_code == PPPOE_PADI && pppoe_length > 1484 - PPPOE_HDRLEN) { 130 printf(" [len %d!]",pppoe_length); 131 } 132 if (pppoe_sessionid) { 133 printf(" [ses 0x%x]", pppoe_sessionid); 134 } 135 136 if (pppoe_payload + pppoe_length < snapend && snapend-pppoe_payload+14 > 64) { 137 /* (small packets are probably just padded up to the ethernet 138 minimum of 64 bytes) */ 139 printf(" [length %d (%d extra bytes)]", 140 pppoe_length, snapend - pppoe_payload - pppoe_length); 141 #if RESPECT_PAYLOAD_LENGTH 142 snapend = pppoe_payload+pppoe_length; 143 #else 144 /* Actual PPPoE implementations appear to ignore the payload 145 length and use the full ethernet frame anyways */ 146 pppoe_length = snapend-pppoe_payload; 147 #endif 148 149 } 150 151 if (pppoe_code) { 152 /* PPP session packets don't contain tags */ 153 u_short tag_type = 0xffff, tag_len; 154 const u_char *p = pppoe_payload; 155 156 /* 157 * loop invariant: 158 * p points to next tag, 159 * tag_type is previous tag or 0xffff for first iteration 160 */ 161 while (tag_type && p + 4 < pppoe_payload + length && 162 p + 4 < snapend) { 163 tag_type = EXTRACT_16BITS(p); 164 tag_len = EXTRACT_16BITS(p + 2); 165 p += 4; 166 /* p points to tag_value */ 167 168 if (tag_len) { 169 unsigned isascii = 0, isgarbage = 0; 170 const u_char *v = p; 171 char tag_str[MAXTAGPRINT]; 172 unsigned tag_str_len = 0; 173 174 /* TODO print UTF-8 decoded text */ 175 for (v = p; v < p + tag_len && tag_str_len < MAXTAGPRINT-1; v++) 176 if (*v >= 32 && *v < 127) { 177 tag_str[tag_str_len++] = *v; 178 isascii++; 179 } else { 180 tag_str[tag_str_len++] = '.'; 181 isgarbage++; 182 } 183 tag_str[tag_str_len] = 0; 184 185 if (isascii > isgarbage) { 186 printf(" [%s \"%*.*s\"]", 187 tok2str(pppoetag2str, "TAG-0x%x", tag_type), 188 (int)tag_str_len, 189 (int)tag_str_len, 190 tag_str); 191 } else { 192 /* Print hex, not fast to abuse printf but this doesn't get used much */ 193 printf(" [%s 0x", tok2str(pppoetag2str, "TAG-0x%x", tag_type)); 194 for (v=p; v<p+tag_len; v++) { 195 printf("%02X", *v); 196 } 197 printf("]"); 198 } 199 200 201 } else 202 printf(" [%s]", tok2str(pppoetag2str, 203 "TAG-0x%x", tag_type)); 204 205 p += tag_len; 206 /* p points to next tag */ 207 } 208 return (0); 209 } else { 210 /* PPPoE data */ 211 printf(" "); 212 return (PPPOE_HDRLEN + ppp_print(pppoe_payload, pppoe_length)); 213 } 214 215 trunc: 216 printf("[|pppoe]"); 217 return (PPPOE_HDRLEN); 218 } 219