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