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 1.7 2017/02/05 04:05:05 spz Exp $"); 27 #endif 28 29 /* \summary: PPP-over-Ethernet (PPPoE) printer */ 30 31 #ifdef HAVE_CONFIG_H 32 #include "config.h" 33 #endif 34 35 #include <netdissect-stdinc.h> 36 37 #include "netdissect.h" 38 #include "extract.h" 39 40 /* Codes */ 41 enum { 42 PPPOE_PADI = 0x09, 43 PPPOE_PADO = 0x07, 44 PPPOE_PADR = 0x19, 45 PPPOE_PADS = 0x65, 46 PPPOE_PADT = 0xa7 47 }; 48 49 static const struct tok pppoecode2str[] = { 50 { PPPOE_PADI, "PADI" }, 51 { PPPOE_PADO, "PADO" }, 52 { PPPOE_PADR, "PADR" }, 53 { PPPOE_PADS, "PADS" }, 54 { PPPOE_PADT, "PADT" }, 55 { 0, "" }, /* PPP Data */ 56 { 0, NULL } 57 }; 58 59 /* Tags */ 60 enum { 61 PPPOE_EOL = 0, 62 PPPOE_SERVICE_NAME = 0x0101, 63 PPPOE_AC_NAME = 0x0102, 64 PPPOE_HOST_UNIQ = 0x0103, 65 PPPOE_AC_COOKIE = 0x0104, 66 PPPOE_VENDOR = 0x0105, 67 PPPOE_RELAY_SID = 0x0110, 68 PPPOE_MAX_PAYLOAD = 0x0120, 69 PPPOE_SERVICE_NAME_ERROR = 0x0201, 70 PPPOE_AC_SYSTEM_ERROR = 0x0202, 71 PPPOE_GENERIC_ERROR = 0x0203 72 }; 73 74 static const struct tok pppoetag2str[] = { 75 { PPPOE_EOL, "EOL" }, 76 { PPPOE_SERVICE_NAME, "Service-Name" }, 77 { PPPOE_AC_NAME, "AC-Name" }, 78 { PPPOE_HOST_UNIQ, "Host-Uniq" }, 79 { PPPOE_AC_COOKIE, "AC-Cookie" }, 80 { PPPOE_VENDOR, "Vendor-Specific" }, 81 { PPPOE_RELAY_SID, "Relay-Session-ID" }, 82 { PPPOE_MAX_PAYLOAD, "PPP-Max-Payload" }, 83 { PPPOE_SERVICE_NAME_ERROR, "Service-Name-Error" }, 84 { PPPOE_AC_SYSTEM_ERROR, "AC-System-Error" }, 85 { PPPOE_GENERIC_ERROR, "Generic-Error" }, 86 { 0, NULL } 87 }; 88 89 #define PPPOE_HDRLEN 6 90 #define MAXTAGPRINT 80 91 92 u_int 93 pppoe_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, register const u_char *p) 94 { 95 return (pppoe_print(ndo, p, h->len)); 96 } 97 98 u_int 99 pppoe_print(netdissect_options *ndo, register const u_char *bp, u_int length) 100 { 101 uint16_t pppoe_ver, pppoe_type, pppoe_code, pppoe_sessionid; 102 u_int pppoe_length; 103 const u_char *pppoe_packet, *pppoe_payload; 104 105 if (length < PPPOE_HDRLEN) { 106 ND_PRINT((ndo, "truncated-pppoe %u", length)); 107 return (length); 108 } 109 length -= PPPOE_HDRLEN; 110 pppoe_packet = bp; 111 ND_TCHECK2(*pppoe_packet, PPPOE_HDRLEN); 112 pppoe_ver = (pppoe_packet[0] & 0xF0) >> 4; 113 pppoe_type = (pppoe_packet[0] & 0x0F); 114 pppoe_code = pppoe_packet[1]; 115 pppoe_sessionid = EXTRACT_16BITS(pppoe_packet + 2); 116 pppoe_length = EXTRACT_16BITS(pppoe_packet + 4); 117 pppoe_payload = pppoe_packet + PPPOE_HDRLEN; 118 119 if (pppoe_ver != 1) { 120 ND_PRINT((ndo, " [ver %d]",pppoe_ver)); 121 } 122 if (pppoe_type != 1) { 123 ND_PRINT((ndo, " [type %d]",pppoe_type)); 124 } 125 126 ND_PRINT((ndo, "PPPoE %s", tok2str(pppoecode2str, "PAD-%x", pppoe_code))); 127 if (pppoe_code == PPPOE_PADI && pppoe_length > 1484 - PPPOE_HDRLEN) { 128 ND_PRINT((ndo, " [len %u!]",pppoe_length)); 129 } 130 if (pppoe_length > length) { 131 ND_PRINT((ndo, " [len %u > %u!]", pppoe_length, length)); 132 pppoe_length = length; 133 } 134 if (pppoe_sessionid) { 135 ND_PRINT((ndo, " [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 ND_TCHECK2(*p, 4); 150 tag_type = EXTRACT_16BITS(p); 151 tag_len = EXTRACT_16BITS(p + 2); 152 p += 4; 153 /* p points to tag_value */ 154 155 if (tag_len) { 156 unsigned ascii_count = 0, garbage_count = 0; 157 const u_char *v; 158 char tag_str[MAXTAGPRINT]; 159 unsigned tag_str_len = 0; 160 161 /* TODO print UTF-8 decoded text */ 162 ND_TCHECK2(*p, tag_len); 163 for (v = p; v < p + tag_len && tag_str_len < MAXTAGPRINT-1; v++) 164 if (*v >= 32 && *v < 127) { 165 tag_str[tag_str_len++] = *v; 166 ascii_count++; 167 } else { 168 tag_str[tag_str_len++] = '.'; 169 garbage_count++; 170 } 171 tag_str[tag_str_len] = 0; 172 173 if (ascii_count > garbage_count) { 174 ND_PRINT((ndo, " [%s \"%*.*s\"]", 175 tok2str(pppoetag2str, "TAG-0x%x", tag_type), 176 (int)tag_str_len, 177 (int)tag_str_len, 178 tag_str)); 179 } else { 180 /* Print hex, not fast to abuse printf but this doesn't get used much */ 181 ND_PRINT((ndo, " [%s 0x", tok2str(pppoetag2str, "TAG-0x%x", tag_type))); 182 for (v=p; v<p+tag_len; v++) { 183 ND_PRINT((ndo, "%02X", *v)); 184 } 185 ND_PRINT((ndo, "]")); 186 } 187 188 189 } else 190 ND_PRINT((ndo, " [%s]", tok2str(pppoetag2str, 191 "TAG-0x%x", tag_type))); 192 193 p += tag_len; 194 /* p points to next tag */ 195 } 196 return (0); 197 } else { 198 /* PPPoE data */ 199 ND_PRINT((ndo, " ")); 200 return (PPPOE_HDRLEN + ppp_print(ndo, pppoe_payload, pppoe_length)); 201 } 202 203 trunc: 204 ND_PRINT((ndo, "[|pppoe]")); 205 return (PPPOE_HDRLEN); 206 } 207