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Diffstat (limited to '')
| -rw-r--r-- | print-pppoe.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/print-pppoe.c b/print-pppoe.c new file mode 100644 index 0000000..65518df --- /dev/null +++ b/print-pppoe.c @@ -0,0 +1,206 @@ +/* + * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that: (1) source code distributions + * retain the above copyright notice and this paragraph in its entirety, (2) + * distributions including binary code include the above copyright notice and + * this paragraph in its entirety in the documentation or other materials + * provided with the distribution, and (3) all advertising materials mentioning + * features or use of this software display the following acknowledgement: + * ``This product includes software developed by the University of California, + * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of + * the University nor the names of its contributors may be used to endorse + * or promote products derived from this software without specific prior + * written permission. + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. + * + * Original code by Greg Stark <gsstark@mit.edu> + */ + +/* \summary: PPP-over-Ethernet (PPPoE) printer */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include "netdissect-stdinc.h" + +#include "netdissect-ctype.h" + +#define ND_LONGJMP_FROM_TCHECK +#include "netdissect.h" +#include "extract.h" + +/* Codes */ +enum { + PPPOE_PADI = 0x09, + PPPOE_PADO = 0x07, + PPPOE_PADR = 0x19, + PPPOE_PADS = 0x65, + PPPOE_PADT = 0xa7 +}; + +static const struct tok pppoecode2str[] = { + { PPPOE_PADI, "PADI" }, + { PPPOE_PADO, "PADO" }, + { PPPOE_PADR, "PADR" }, + { PPPOE_PADS, "PADS" }, + { PPPOE_PADT, "PADT" }, + { 0, "" }, /* PPP Data */ + { 0, NULL } +}; + +/* Tags */ +enum { + PPPOE_EOL = 0, + PPPOE_SERVICE_NAME = 0x0101, + PPPOE_AC_NAME = 0x0102, + PPPOE_HOST_UNIQ = 0x0103, + PPPOE_AC_COOKIE = 0x0104, + PPPOE_VENDOR = 0x0105, + PPPOE_RELAY_SID = 0x0110, + PPPOE_MAX_PAYLOAD = 0x0120, + PPPOE_SERVICE_NAME_ERROR = 0x0201, + PPPOE_AC_SYSTEM_ERROR = 0x0202, + PPPOE_GENERIC_ERROR = 0x0203 +}; + +static const struct tok pppoetag2str[] = { + { PPPOE_EOL, "EOL" }, + { PPPOE_SERVICE_NAME, "Service-Name" }, + { PPPOE_AC_NAME, "AC-Name" }, + { PPPOE_HOST_UNIQ, "Host-Uniq" }, + { PPPOE_AC_COOKIE, "AC-Cookie" }, + { PPPOE_VENDOR, "Vendor-Specific" }, + { PPPOE_RELAY_SID, "Relay-Session-ID" }, + { PPPOE_MAX_PAYLOAD, "PPP-Max-Payload" }, + { PPPOE_SERVICE_NAME_ERROR, "Service-Name-Error" }, + { PPPOE_AC_SYSTEM_ERROR, "AC-System-Error" }, + { PPPOE_GENERIC_ERROR, "Generic-Error" }, + { 0, NULL } +}; + +#define PPPOE_HDRLEN 6 +#define MAXTAGPRINT 80 + +void +pppoe_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p) +{ + ndo->ndo_protocol = "pppoe"; + ndo->ndo_ll_hdr_len += pppoe_print(ndo, p, h->len); +} + +u_int +pppoe_print(netdissect_options *ndo, const u_char *bp, u_int length) +{ + uint16_t pppoe_ver, pppoe_type, pppoe_code, pppoe_sessionid; + u_int pppoe_length; + const u_char *pppoe_packet, *pppoe_payload; + + ndo->ndo_protocol = "pppoe"; + if (length < PPPOE_HDRLEN) { + ND_PRINT(" (length %u < %u)", length, PPPOE_HDRLEN); + goto invalid; + } + length -= PPPOE_HDRLEN; + pppoe_packet = bp; + ND_TCHECK_LEN(pppoe_packet, PPPOE_HDRLEN); + pppoe_ver = (GET_U_1(pppoe_packet) & 0xF0) >> 4; + pppoe_type = (GET_U_1(pppoe_packet) & 0x0F); + pppoe_code = GET_U_1(pppoe_packet + 1); + pppoe_sessionid = GET_BE_U_2(pppoe_packet + 2); + pppoe_length = GET_BE_U_2(pppoe_packet + 4); + pppoe_payload = pppoe_packet + PPPOE_HDRLEN; + + if (pppoe_ver != 1) { + ND_PRINT(" [ver %u]",pppoe_ver); + } + if (pppoe_type != 1) { + ND_PRINT(" [type %u]",pppoe_type); + } + + ND_PRINT("PPPoE %s", tok2str(pppoecode2str, "PAD-%x", pppoe_code)); + if (pppoe_code == PPPOE_PADI && pppoe_length > 1484 - PPPOE_HDRLEN) { + ND_PRINT(" [len %u!]",pppoe_length); + } + if (pppoe_length > length) { + ND_PRINT(" [len %u > %u!]", pppoe_length, length); + pppoe_length = length; + } + if (pppoe_sessionid) { + ND_PRINT(" [ses 0x%x]", pppoe_sessionid); + } + + if (pppoe_code) { + /* PPP session packets don't contain tags */ + u_short tag_type = 0xffff, tag_len; + const u_char *p = pppoe_payload; + + /* + * loop invariant: + * p points to current tag, + * tag_type is previous tag or 0xffff for first iteration + */ + while (tag_type && p < pppoe_payload + pppoe_length) { + tag_type = GET_BE_U_2(p); + tag_len = GET_BE_U_2(p + 2); + p += 4; + /* p points to tag_value */ + + if (tag_len) { + unsigned ascii_count = 0, garbage_count = 0; + const u_char *v; + char tag_str[MAXTAGPRINT]; + unsigned tag_str_len = 0; + + /* TODO print UTF-8 decoded text */ + ND_TCHECK_LEN(p, tag_len); + for (v = p; v < p + tag_len && tag_str_len < MAXTAGPRINT-1; v++) + if (ND_ASCII_ISPRINT(GET_U_1(v))) { + tag_str[tag_str_len++] = GET_U_1(v); + ascii_count++; + } else { + tag_str[tag_str_len++] = '.'; + garbage_count++; + } + tag_str[tag_str_len] = 0; + + if (ascii_count > garbage_count) { + ND_PRINT(" [%s \"%*.*s\"]", + tok2str(pppoetag2str, "TAG-0x%x", tag_type), + (int)tag_str_len, + (int)tag_str_len, + tag_str); + } else { + /* Print hex, not fast to abuse printf but this doesn't get used much */ + ND_PRINT(" [%s 0x", tok2str(pppoetag2str, "TAG-0x%x", tag_type)); + for (v=p; v<p+tag_len; v++) { + ND_PRINT("%02X", GET_U_1(v)); + } + ND_PRINT("]"); + } + + + } else + ND_PRINT(" [%s]", tok2str(pppoetag2str, + "TAG-0x%x", tag_type)); + + p += tag_len; + /* p points to next tag */ + } + return PPPOE_HDRLEN; + } else { + /* PPPoE data */ + ND_PRINT(" "); + return (PPPOE_HDRLEN + ppp_print(ndo, pppoe_payload, pppoe_length)); + } + /* NOTREACHED */ + +invalid: + nd_print_invalid(ndo); + return 0; +} |