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 #include <sys/cdefs.h> 25 #ifndef lint 26 __RCSID("$NetBSD: print-pppoe.c,v 1.6 2017/01/24 23:29:14 christos Exp $"); 27 #endif 28 29 #ifdef HAVE_CONFIG_H 30 #include "config.h" 31 #endif 32 33 #include <netdissect-stdinc.h> 34 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 u_int 91 pppoe_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, register const u_char *p) 92 { 93 return (pppoe_print(ndo, p, h->len)); 94 } 95 96 u_int 97 pppoe_print(netdissect_options *ndo, register const u_char *bp, u_int length) 98 { 99 uint16_t pppoe_ver, pppoe_type, pppoe_code, pppoe_sessionid; 100 u_int pppoe_length; 101 const u_char *pppoe_packet, *pppoe_payload; 102 103 if (length < PPPOE_HDRLEN) { 104 ND_PRINT((ndo, "truncated-pppoe %u", length)); 105 return (length); 106 } 107 length -= PPPOE_HDRLEN; 108 pppoe_packet = bp; 109 ND_TCHECK2(*pppoe_packet, PPPOE_HDRLEN); 110 pppoe_ver = (pppoe_packet[0] & 0xF0) >> 4; 111 pppoe_type = (pppoe_packet[0] & 0x0F); 112 pppoe_code = pppoe_packet[1]; 113 pppoe_sessionid = EXTRACT_16BITS(pppoe_packet + 2); 114 pppoe_length = EXTRACT_16BITS(pppoe_packet + 4); 115 pppoe_payload = pppoe_packet + PPPOE_HDRLEN; 116 117 if (pppoe_ver != 1) { 118 ND_PRINT((ndo, " [ver %d]",pppoe_ver)); 119 } 120 if (pppoe_type != 1) { 121 ND_PRINT((ndo, " [type %d]",pppoe_type)); 122 } 123 124 ND_PRINT((ndo, "PPPoE %s", tok2str(pppoecode2str, "PAD-%x", pppoe_code))); 125 if (pppoe_code == PPPOE_PADI && pppoe_length > 1484 - PPPOE_HDRLEN) { 126 ND_PRINT((ndo, " [len %u!]",pppoe_length)); 127 } 128 if (pppoe_length > length) { 129 ND_PRINT((ndo, " [len %u > %u!]", pppoe_length, length)); 130 pppoe_length = length; 131 } 132 if (pppoe_sessionid) { 133 ND_PRINT((ndo, " [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 ND_TCHECK2(*p, 4); 148 tag_type = EXTRACT_16BITS(p); 149 tag_len = EXTRACT_16BITS(p + 2); 150 p += 4; 151 /* p points to tag_value */ 152 153 if (tag_len) { 154 unsigned ascii_count = 0, garbage_count = 0; 155 const u_char *v; 156 char tag_str[MAXTAGPRINT]; 157 unsigned tag_str_len = 0; 158 159 /* TODO print UTF-8 decoded text */ 160 ND_TCHECK2(*p, tag_len); 161 for (v = p; v < p + tag_len && tag_str_len < MAXTAGPRINT-1; v++) 162 if (*v >= 32 && *v < 127) { 163 tag_str[tag_str_len++] = *v; 164 ascii_count++; 165 } else { 166 tag_str[tag_str_len++] = '.'; 167 garbage_count++; 168 } 169 tag_str[tag_str_len] = 0; 170 171 if (ascii_count > garbage_count) { 172 ND_PRINT((ndo, " [%s \"%*.*s\"]", 173 tok2str(pppoetag2str, "TAG-0x%x", tag_type), 174 (int)tag_str_len, 175 (int)tag_str_len, 176 tag_str)); 177 } else { 178 /* Print hex, not fast to abuse printf but this doesn't get used much */ 179 ND_PRINT((ndo, " [%s 0x", tok2str(pppoetag2str, "TAG-0x%x", tag_type))); 180 for (v=p; v<p+tag_len; v++) { 181 ND_PRINT((ndo, "%02X", *v)); 182 } 183 ND_PRINT((ndo, "]")); 184 } 185 186 187 } else 188 ND_PRINT((ndo, " [%s]", tok2str(pppoetag2str, 189 "TAG-0x%x", tag_type))); 190 191 p += tag_len; 192 /* p points to next tag */ 193 } 194 return (0); 195 } else { 196 /* PPPoE data */ 197 ND_PRINT((ndo, " ")); 198 return (PPPOE_HDRLEN + ppp_print(ndo, pppoe_payload, pppoe_length)); 199 } 200 201 trunc: 202 ND_PRINT((ndo, "[|pppoe]")); 203 return (PPPOE_HDRLEN); 204 } 205