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 /* \summary: PPP-over-Ethernet (PPPoE) printer */ 25 26 #ifdef HAVE_CONFIG_H 27 #include <config.h> 28 #endif 29 30 #include "netdissect-stdinc.h" 31 32 #include "netdissect-ctype.h" 33 34 #define ND_LONGJMP_FROM_TCHECK 35 #include "netdissect.h" 36 #include "extract.h" 37 38 /* Codes */ 39 enum { 40 PPPOE_PADI = 0x09, 41 PPPOE_PADO = 0x07, 42 PPPOE_PADR = 0x19, 43 PPPOE_PADS = 0x65, 44 PPPOE_PADT = 0xa7 45 }; 46 47 static const struct tok pppoecode2str[] = { 48 { PPPOE_PADI, "PADI" }, 49 { PPPOE_PADO, "PADO" }, 50 { PPPOE_PADR, "PADR" }, 51 { PPPOE_PADS, "PADS" }, 52 { PPPOE_PADT, "PADT" }, 53 { 0, "" }, /* PPP Data */ 54 { 0, NULL } 55 }; 56 57 /* Tags */ 58 enum { 59 PPPOE_EOL = 0, 60 PPPOE_SERVICE_NAME = 0x0101, 61 PPPOE_AC_NAME = 0x0102, 62 PPPOE_HOST_UNIQ = 0x0103, 63 PPPOE_AC_COOKIE = 0x0104, 64 PPPOE_VENDOR = 0x0105, 65 PPPOE_RELAY_SID = 0x0110, 66 PPPOE_MAX_PAYLOAD = 0x0120, 67 PPPOE_SERVICE_NAME_ERROR = 0x0201, 68 PPPOE_AC_SYSTEM_ERROR = 0x0202, 69 PPPOE_GENERIC_ERROR = 0x0203 70 }; 71 72 static const struct tok pppoetag2str[] = { 73 { PPPOE_EOL, "EOL" }, 74 { PPPOE_SERVICE_NAME, "Service-Name" }, 75 { PPPOE_AC_NAME, "AC-Name" }, 76 { PPPOE_HOST_UNIQ, "Host-Uniq" }, 77 { PPPOE_AC_COOKIE, "AC-Cookie" }, 78 { PPPOE_VENDOR, "Vendor-Specific" }, 79 { PPPOE_RELAY_SID, "Relay-Session-ID" }, 80 { PPPOE_MAX_PAYLOAD, "PPP-Max-Payload" }, 81 { PPPOE_SERVICE_NAME_ERROR, "Service-Name-Error" }, 82 { PPPOE_AC_SYSTEM_ERROR, "AC-System-Error" }, 83 { PPPOE_GENERIC_ERROR, "Generic-Error" }, 84 { 0, NULL } 85 }; 86 87 #define PPPOE_HDRLEN 6 88 #define MAXTAGPRINT 80 89 90 void 91 pppoe_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p) 92 { 93 ndo->ndo_protocol = "pppoe"; 94 ndo->ndo_ll_hdr_len += pppoe_print(ndo, p, h->len); 95 } 96 97 u_int 98 pppoe_print(netdissect_options *ndo, 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 ndo->ndo_protocol = "pppoe"; 105 if (length < PPPOE_HDRLEN) { 106 ND_PRINT(" (length %u < %u)", length, PPPOE_HDRLEN); 107 goto invalid; 108 } 109 length -= PPPOE_HDRLEN; 110 pppoe_packet = bp; 111 ND_TCHECK_LEN(pppoe_packet, PPPOE_HDRLEN); 112 pppoe_ver = (GET_U_1(pppoe_packet) & 0xF0) >> 4; 113 pppoe_type = (GET_U_1(pppoe_packet) & 0x0F); 114 pppoe_code = GET_U_1(pppoe_packet + 1); 115 pppoe_sessionid = GET_BE_U_2(pppoe_packet + 2); 116 pppoe_length = GET_BE_U_2(pppoe_packet + 4); 117 pppoe_payload = pppoe_packet + PPPOE_HDRLEN; 118 119 if (pppoe_ver != 1) { 120 ND_PRINT(" [ver %u]",pppoe_ver); 121 } 122 if (pppoe_type != 1) { 123 ND_PRINT(" [type %u]",pppoe_type); 124 } 125 126 ND_PRINT("PPPoE %s", tok2str(pppoecode2str, "PAD-%x", pppoe_code)); 127 if (pppoe_code == PPPOE_PADI && pppoe_length > 1484 - PPPOE_HDRLEN) { 128 ND_PRINT(" [len %u!]",pppoe_length); 129 } 130 if (pppoe_length > length) { 131 ND_PRINT(" [len %u > %u!]", pppoe_length, length); 132 pppoe_length = length; 133 } 134 if (pppoe_sessionid) { 135 ND_PRINT(" [ses 0x%x]", pppoe_sessionid); 136 } 137 138 if (pppoe_code) { 139 /* PPP session packets don't contain tags */ 140 u_short tag_type = 0xffff, tag_len; 141 const u_char *p = pppoe_payload; 142 143 /* 144 * loop invariant: 145 * p points to current tag, 146 * tag_type is previous tag or 0xffff for first iteration 147 */ 148 while (tag_type && p < pppoe_payload + pppoe_length) { 149 tag_type = GET_BE_U_2(p); 150 tag_len = GET_BE_U_2(p + 2); 151 p += 4; 152 /* p points to tag_value */ 153 154 if (tag_len) { 155 unsigned ascii_count = 0, garbage_count = 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_TCHECK_LEN(p, tag_len); 162 for (v = p; v < p + tag_len && tag_str_len < MAXTAGPRINT-1; v++) 163 if (ND_ASCII_ISPRINT(GET_U_1(v))) { 164 tag_str[tag_str_len++] = GET_U_1(v); 165 ascii_count++; 166 } else { 167 tag_str[tag_str_len++] = '.'; 168 garbage_count++; 169 } 170 tag_str[tag_str_len] = 0; 171 172 if (ascii_count > garbage_count) { 173 ND_PRINT(" [%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(" [%s 0x", tok2str(pppoetag2str, "TAG-0x%x", tag_type)); 181 for (v=p; v<p+tag_len; v++) { 182 ND_PRINT("%02X", GET_U_1(v)); 183 } 184 ND_PRINT("]"); 185 } 186 187 188 } else 189 ND_PRINT(" [%s]", tok2str(pppoetag2str, 190 "TAG-0x%x", tag_type)); 191 192 p += tag_len; 193 /* p points to next tag */ 194 } 195 return PPPOE_HDRLEN; 196 } else { 197 /* PPPoE data */ 198 ND_PRINT(" "); 199 return (PPPOE_HDRLEN + ppp_print(ndo, pppoe_payload, pppoe_length)); 200 } 201 /* NOTREACHED */ 202 203 invalid: 204 nd_print_invalid(ndo); 205 return 0; 206 } 207