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 #include <config.h> 27 28 #include "netdissect-stdinc.h" 29 30 #include "netdissect-ctype.h" 31 32 #define ND_LONGJMP_FROM_TCHECK 33 #include "netdissect.h" 34 #include "extract.h" 35 36 /* Codes */ 37 enum { 38 PPPOE_PADI = 0x09, 39 PPPOE_PADO = 0x07, 40 PPPOE_PADR = 0x19, 41 PPPOE_PADS = 0x65, 42 PPPOE_PADT = 0xa7 43 }; 44 45 static const struct tok pppoecode2str[] = { 46 { PPPOE_PADI, "PADI" }, 47 { PPPOE_PADO, "PADO" }, 48 { PPPOE_PADR, "PADR" }, 49 { PPPOE_PADS, "PADS" }, 50 { PPPOE_PADT, "PADT" }, 51 { 0, "" }, /* PPP Data */ 52 { 0, NULL } 53 }; 54 55 /* Tags */ 56 enum { 57 PPPOE_EOL = 0, 58 PPPOE_SERVICE_NAME = 0x0101, 59 PPPOE_AC_NAME = 0x0102, 60 PPPOE_HOST_UNIQ = 0x0103, 61 PPPOE_AC_COOKIE = 0x0104, 62 PPPOE_VENDOR = 0x0105, 63 PPPOE_RELAY_SID = 0x0110, 64 PPPOE_MAX_PAYLOAD = 0x0120, 65 PPPOE_SERVICE_NAME_ERROR = 0x0201, 66 PPPOE_AC_SYSTEM_ERROR = 0x0202, 67 PPPOE_GENERIC_ERROR = 0x0203 68 }; 69 70 static const struct tok pppoetag2str[] = { 71 { PPPOE_EOL, "EOL" }, 72 { PPPOE_SERVICE_NAME, "Service-Name" }, 73 { PPPOE_AC_NAME, "AC-Name" }, 74 { PPPOE_HOST_UNIQ, "Host-Uniq" }, 75 { PPPOE_AC_COOKIE, "AC-Cookie" }, 76 { PPPOE_VENDOR, "Vendor-Specific" }, 77 { PPPOE_RELAY_SID, "Relay-Session-ID" }, 78 { PPPOE_MAX_PAYLOAD, "PPP-Max-Payload" }, 79 { PPPOE_SERVICE_NAME_ERROR, "Service-Name-Error" }, 80 { PPPOE_AC_SYSTEM_ERROR, "AC-System-Error" }, 81 { PPPOE_GENERIC_ERROR, "Generic-Error" }, 82 { 0, NULL } 83 }; 84 85 #define PPPOE_HDRLEN 6 86 #define MAXTAGPRINT 80 87 88 void 89 pppoe_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p) 90 { 91 ndo->ndo_protocol = "pppoe"; 92 ndo->ndo_ll_hdr_len += pppoe_print(ndo, p, h->len); 93 } 94 95 u_int 96 pppoe_print(netdissect_options *ndo, const u_char *bp, u_int length) 97 { 98 uint16_t pppoe_ver, pppoe_type, pppoe_code, pppoe_sessionid; 99 u_int pppoe_length; 100 const u_char *pppoe_packet, *pppoe_payload; 101 102 ndo->ndo_protocol = "pppoe"; 103 if (length < PPPOE_HDRLEN) { 104 ND_PRINT(" (length %u < %u)", length, PPPOE_HDRLEN); 105 goto invalid; 106 } 107 length -= PPPOE_HDRLEN; 108 pppoe_packet = bp; 109 ND_TCHECK_LEN(pppoe_packet, PPPOE_HDRLEN); 110 pppoe_ver = (GET_U_1(pppoe_packet) & 0xF0) >> 4; 111 pppoe_type = (GET_U_1(pppoe_packet) & 0x0F); 112 pppoe_code = GET_U_1(pppoe_packet + 1); 113 pppoe_sessionid = GET_BE_U_2(pppoe_packet + 2); 114 pppoe_length = GET_BE_U_2(pppoe_packet + 4); 115 pppoe_payload = pppoe_packet + PPPOE_HDRLEN; 116 117 if (pppoe_ver != 1) { 118 ND_PRINT(" [ver %u]",pppoe_ver); 119 } 120 if (pppoe_type != 1) { 121 ND_PRINT(" [type %u]",pppoe_type); 122 } 123 124 ND_PRINT("PPPoE %s", tok2str(pppoecode2str, "PAD-%x", pppoe_code)); 125 if (pppoe_code == PPPOE_PADI && pppoe_length > 1484 - PPPOE_HDRLEN) { 126 ND_PRINT(" [len %u!]",pppoe_length); 127 } 128 if (pppoe_length > length) { 129 ND_PRINT(" [len %u > %u!]", pppoe_length, length); 130 pppoe_length = length; 131 } 132 if (pppoe_sessionid) { 133 ND_PRINT(" [ses 0x%x]", pppoe_sessionid); 134 } 135 136 if (pppoe_code) { 137 /* PPP session packets don't contain tags */ 138 u_short tag_type = 0xffff, tag_len; 139 const u_char *p = pppoe_payload; 140 141 /* 142 * loop invariant: 143 * p points to current tag, 144 * tag_type is previous tag or 0xffff for first iteration 145 */ 146 while (tag_type && p < pppoe_payload + pppoe_length) { 147 tag_type = GET_BE_U_2(p); 148 tag_len = GET_BE_U_2(p + 2); 149 p += 4; 150 /* p points to tag_value */ 151 152 if (tag_len) { 153 unsigned ascii_count = 0, garbage_count = 0; 154 const u_char *v; 155 char tag_str[MAXTAGPRINT]; 156 unsigned tag_str_len = 0; 157 158 /* TODO print UTF-8 decoded text */ 159 ND_TCHECK_LEN(p, tag_len); 160 for (v = p; v < p + tag_len && tag_str_len < MAXTAGPRINT-1; v++) 161 if (ND_ASCII_ISPRINT(GET_U_1(v))) { 162 tag_str[tag_str_len++] = GET_U_1(v); 163 ascii_count++; 164 } else { 165 tag_str[tag_str_len++] = '.'; 166 garbage_count++; 167 } 168 tag_str[tag_str_len] = 0; 169 170 if (ascii_count > garbage_count) { 171 ND_PRINT(" [%s \"%*.*s\"]", 172 tok2str(pppoetag2str, "TAG-0x%x", tag_type), 173 (int)tag_str_len, 174 (int)tag_str_len, 175 tag_str); 176 } else { 177 /* Print hex, not fast to abuse printf but this doesn't get used much */ 178 ND_PRINT(" [%s 0x", tok2str(pppoetag2str, "TAG-0x%x", tag_type)); 179 for (v=p; v<p+tag_len; v++) { 180 ND_PRINT("%02X", GET_U_1(v)); 181 } 182 ND_PRINT("]"); 183 } 184 185 186 } else 187 ND_PRINT(" [%s]", tok2str(pppoetag2str, 188 "TAG-0x%x", tag_type)); 189 190 p += tag_len; 191 /* p points to next tag */ 192 } 193 return PPPOE_HDRLEN; 194 } else { 195 /* PPPoE data */ 196 ND_PRINT(" "); 197 return (PPPOE_HDRLEN + ppp_print(ndo, pppoe_payload, pppoe_length)); 198 } 199 /* NOTREACHED */ 200 201 invalid: 202 nd_print_invalid(ndo); 203 return 0; 204 } 205