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 (at) mit.edu> 22 */ 23 24 #define NETDISSECT_REWORKED 25 #ifdef HAVE_CONFIG_H 26 #include "config.h" 27 #endif 28 29 #include <tcpdump-stdinc.h> 30 31 #include "interface.h" 32 #include "extract.h" /* must come after interface.h */ 33 34 /* Codes */ 35 enum { 36 PPPOE_PADI = 0x09, 37 PPPOE_PADO = 0x07, 38 PPPOE_PADR = 0x19, 39 PPPOE_PADS = 0x65, 40 PPPOE_PADT = 0xa7 41 }; 42 43 static const struct tok pppoecode2str[] = { 44 { PPPOE_PADI, "PADI" }, 45 { PPPOE_PADO, "PADO" }, 46 { PPPOE_PADR, "PADR" }, 47 { PPPOE_PADS, "PADS" }, 48 { PPPOE_PADT, "PADT" }, 49 { 0, "" }, /* PPP Data */ 50 { 0, NULL } 51 }; 52 53 /* Tags */ 54 enum { 55 PPPOE_EOL = 0, 56 PPPOE_SERVICE_NAME = 0x0101, 57 PPPOE_AC_NAME = 0x0102, 58 PPPOE_HOST_UNIQ = 0x0103, 59 PPPOE_AC_COOKIE = 0x0104, 60 PPPOE_VENDOR = 0x0105, 61 PPPOE_RELAY_SID = 0x0110, 62 PPPOE_MAX_PAYLOAD = 0x0120, 63 PPPOE_SERVICE_NAME_ERROR = 0x0201, 64 PPPOE_AC_SYSTEM_ERROR = 0x0202, 65 PPPOE_GENERIC_ERROR = 0x0203 66 }; 67 68 static const struct tok pppoetag2str[] = { 69 { PPPOE_EOL, "EOL" }, 70 { PPPOE_SERVICE_NAME, "Service-Name" }, 71 { PPPOE_AC_NAME, "AC-Name" }, 72 { PPPOE_HOST_UNIQ, "Host-Uniq" }, 73 { PPPOE_AC_COOKIE, "AC-Cookie" }, 74 { PPPOE_VENDOR, "Vendor-Specific" }, 75 { PPPOE_RELAY_SID, "Relay-Session-ID" }, 76 { PPPOE_MAX_PAYLOAD, "PPP-Max-Payload" }, 77 { PPPOE_SERVICE_NAME_ERROR, "Service-Name-Error" }, 78 { PPPOE_AC_SYSTEM_ERROR, "AC-System-Error" }, 79 { PPPOE_GENERIC_ERROR, "Generic-Error" }, 80 { 0, NULL } 81 }; 82 83 #define PPPOE_HDRLEN 6 84 #define MAXTAGPRINT 80 85 86 u_int 87 pppoe_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, register const u_char *p) 88 { 89 return (pppoe_print(ndo, p, h->len)); 90 } 91 92 u_int 93 pppoe_print(netdissect_options *ndo, register const u_char *bp, u_int length) 94 { 95 uint16_t pppoe_ver, pppoe_type, pppoe_code, pppoe_sessionid; 96 u_int pppoe_length; 97 const u_char *pppoe_packet, *pppoe_payload; 98 99 if (length < PPPOE_HDRLEN) { 100 ND_PRINT((ndo, "truncated-pppoe %u", length)); 101 return (length); 102 } 103 length -= PPPOE_HDRLEN; 104 pppoe_packet = bp; 105 ND_TCHECK2(*pppoe_packet, PPPOE_HDRLEN); 106 pppoe_ver = (pppoe_packet[0] & 0xF0) >> 4; 107 pppoe_type = (pppoe_packet[0] & 0x0F); 108 pppoe_code = pppoe_packet[1]; 109 pppoe_sessionid = EXTRACT_16BITS(pppoe_packet + 2); 110 pppoe_length = EXTRACT_16BITS(pppoe_packet + 4); 111 pppoe_payload = pppoe_packet + PPPOE_HDRLEN; 112 113 if (pppoe_ver != 1) { 114 ND_PRINT((ndo, " [ver %d]",pppoe_ver)); 115 } 116 if (pppoe_type != 1) { 117 ND_PRINT((ndo, " [type %d]",pppoe_type)); 118 } 119 120 ND_PRINT((ndo, "PPPoE %s", tok2str(pppoecode2str, "PAD-%x", pppoe_code))); 121 if (pppoe_code == PPPOE_PADI && pppoe_length > 1484 - PPPOE_HDRLEN) { 122 ND_PRINT((ndo, " [len %u!]",pppoe_length)); 123 } 124 if (pppoe_length > length) { 125 ND_PRINT((ndo, " [len %u > %u!]", pppoe_length, length)); 126 pppoe_length = length; 127 } 128 if (pppoe_sessionid) { 129 ND_PRINT((ndo, " [ses 0x%x]", pppoe_sessionid)); 130 } 131 132 if (pppoe_code) { 133 /* PPP session packets don't contain tags */ 134 u_short tag_type = 0xffff, tag_len; 135 const u_char *p = pppoe_payload; 136 137 /* 138 * loop invariant: 139 * p points to current tag, 140 * tag_type is previous tag or 0xffff for first iteration 141 */ 142 while (tag_type && p < pppoe_payload + pppoe_length) { 143 ND_TCHECK2(*p, 4); 144 tag_type = EXTRACT_16BITS(p); 145 tag_len = EXTRACT_16BITS(p + 2); 146 p += 4; 147 /* p points to tag_value */ 148 149 if (tag_len) { 150 unsigned isascii = 0, isgarbage = 0; 151 const u_char *v; 152 char tag_str[MAXTAGPRINT]; 153 unsigned tag_str_len = 0; 154 155 /* TODO print UTF-8 decoded text */ 156 ND_TCHECK2(*p, tag_len); 157 for (v = p; v < p + tag_len && tag_str_len < MAXTAGPRINT-1; v++) 158 if (*v >= 32 && *v < 127) { 159 tag_str[tag_str_len++] = *v; 160 isascii++; 161 } else { 162 tag_str[tag_str_len++] = '.'; 163 isgarbage++; 164 } 165 tag_str[tag_str_len] = 0; 166 167 if (isascii > isgarbage) { 168 ND_PRINT((ndo, " [%s \"%*.*s\"]", 169 tok2str(pppoetag2str, "TAG-0x%x", tag_type), 170 (int)tag_str_len, 171 (int)tag_str_len, 172 tag_str)); 173 } else { 174 /* Print hex, not fast to abuse printf but this doesn't get used much */ 175 ND_PRINT((ndo, " [%s 0x", tok2str(pppoetag2str, "TAG-0x%x", tag_type))); 176 for (v=p; v<p+tag_len; v++) { 177 ND_PRINT((ndo, "%02X", *v)); 178 } 179 ND_PRINT((ndo, "]")); 180 } 181 182 183 } else 184 ND_PRINT((ndo, " [%s]", tok2str(pppoetag2str, 185 "TAG-0x%x", tag_type))); 186 187 p += tag_len; 188 /* p points to next tag */ 189 } 190 return (0); 191 } else { 192 /* PPPoE data */ 193 ND_PRINT((ndo, " ")); 194 return (PPPOE_HDRLEN + ppp_print(ndo, pppoe_payload, pppoe_length)); 195 } 196 197 trunc: 198 ND_PRINT((ndo, "[|pppoe]")); 199 return (PPPOE_HDRLEN); 200 } 201
