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Diffstat (limited to '')
| -rw-r--r-- | print-ahcp.c | 384 |
1 files changed, 384 insertions, 0 deletions
diff --git a/print-ahcp.c b/print-ahcp.c new file mode 100644 index 0000000..d57edda --- /dev/null +++ b/print-ahcp.c @@ -0,0 +1,384 @@ +/* + * Copyright (c) 2013 The TCPDUMP project + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +/* \summary: Ad Hoc Configuration Protocol (AHCP) printer */ + +/* Based on draft-chroboczek-ahcp-00 and source code of ahcpd-0.53 */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include "netdissect-stdinc.h" + +#define ND_LONGJMP_FROM_TCHECK +#include "netdissect.h" +#include "extract.h" +#include "addrtoname.h" + + +#define AHCP_MAGIC_NUMBER 43 +#define AHCP_VERSION_1 1 +#define AHCP1_HEADER_FIX_LEN 24 +#define AHCP1_BODY_MIN_LEN 4 + +#define AHCP1_MSG_DISCOVER 0 +#define AHCP1_MSG_OFFER 1 +#define AHCP1_MSG_REQUEST 2 +#define AHCP1_MSG_ACK 3 +#define AHCP1_MSG_NACK 4 +#define AHCP1_MSG_RELEASE 5 + +static const struct tok ahcp1_msg_str[] = { + { AHCP1_MSG_DISCOVER, "Discover" }, + { AHCP1_MSG_OFFER, "Offer" }, + { AHCP1_MSG_REQUEST, "Request" }, + { AHCP1_MSG_ACK, "Ack" }, + { AHCP1_MSG_NACK, "Nack" }, + { AHCP1_MSG_RELEASE, "Release" }, + { 0, NULL } +}; + +#define AHCP1_OPT_PAD 0 +#define AHCP1_OPT_MANDATORY 1 +#define AHCP1_OPT_ORIGIN_TIME 2 +#define AHCP1_OPT_EXPIRES 3 +#define AHCP1_OPT_MY_IPV6_ADDRESS 4 +#define AHCP1_OPT_MY_IPV4_ADDRESS 5 +#define AHCP1_OPT_IPV6_PREFIX 6 +#define AHCP1_OPT_IPV4_PREFIX 7 +#define AHCP1_OPT_IPV6_ADDRESS 8 +#define AHCP1_OPT_IPV4_ADDRESS 9 +#define AHCP1_OPT_IPV6_PREFIX_DELEGATION 10 +#define AHCP1_OPT_IPV4_PREFIX_DELEGATION 11 +#define AHCP1_OPT_NAME_SERVER 12 +#define AHCP1_OPT_NTP_SERVER 13 +#define AHCP1_OPT_MAX 13 + +static const struct tok ahcp1_opt_str[] = { + { AHCP1_OPT_PAD, "Pad" }, + { AHCP1_OPT_MANDATORY, "Mandatory" }, + { AHCP1_OPT_ORIGIN_TIME, "Origin Time" }, + { AHCP1_OPT_EXPIRES, "Expires" }, + { AHCP1_OPT_MY_IPV6_ADDRESS, "My-IPv6-Address" }, + { AHCP1_OPT_MY_IPV4_ADDRESS, "My-IPv4-Address" }, + { AHCP1_OPT_IPV6_PREFIX, "IPv6 Prefix" }, + { AHCP1_OPT_IPV4_PREFIX, "IPv4 Prefix" }, + { AHCP1_OPT_IPV6_ADDRESS, "IPv6 Address" }, + { AHCP1_OPT_IPV4_ADDRESS, "IPv4 Address" }, + { AHCP1_OPT_IPV6_PREFIX_DELEGATION, "IPv6 Prefix Delegation" }, + { AHCP1_OPT_IPV4_PREFIX_DELEGATION, "IPv4 Prefix Delegation" }, + { AHCP1_OPT_NAME_SERVER, "Name Server" }, + { AHCP1_OPT_NTP_SERVER, "NTP Server" }, + { 0, NULL } +}; + +static void +ahcp_time_print(netdissect_options *ndo, + const u_char *cp, uint8_t len) +{ + time_t t; + char buf[sizeof("-yyyyyyyyyy-mm-dd hh:mm:ss UTC")]; + + if (len != 4) + goto invalid; + t = GET_BE_U_4(cp); + ND_PRINT(": %s", + nd_format_time(buf, sizeof(buf), "%Y-%m-%d %H:%M:%S UTC", + gmtime(&t))); + return; + +invalid: + nd_print_invalid(ndo); + ND_TCHECK_LEN(cp, len); +} + +static void +ahcp_seconds_print(netdissect_options *ndo, + const u_char *cp, uint8_t len) +{ + if (len != 4) + goto invalid; + ND_PRINT(": %us", GET_BE_U_4(cp)); + return; + +invalid: + nd_print_invalid(ndo); + ND_TCHECK_LEN(cp, len); +} + +static void +ahcp_ipv6_addresses_print(netdissect_options *ndo, + const u_char *cp, uint8_t len) +{ + const char *sep = ": "; + + while (len) { + if (len < 16) + goto invalid; + ND_PRINT("%s%s", sep, GET_IP6ADDR_STRING(cp)); + cp += 16; + len -= 16; + sep = ", "; + } + return; + +invalid: + nd_print_invalid(ndo); + ND_TCHECK_LEN(cp, len); +} + +static void +ahcp_ipv4_addresses_print(netdissect_options *ndo, + const u_char *cp, uint8_t len) +{ + const char *sep = ": "; + + while (len) { + if (len < 4) + goto invalid; + ND_PRINT("%s%s", sep, GET_IPADDR_STRING(cp)); + cp += 4; + len -= 4; + sep = ", "; + } + return; + +invalid: + nd_print_invalid(ndo); + ND_TCHECK_LEN(cp, len); +} + +static void +ahcp_ipv6_prefixes_print(netdissect_options *ndo, + const u_char *cp, uint8_t len) +{ + const char *sep = ": "; + + while (len) { + if (len < 17) + goto invalid; + ND_PRINT("%s%s/%u", sep, GET_IP6ADDR_STRING(cp), GET_U_1(cp + 16)); + cp += 17; + len -= 17; + sep = ", "; + } + return; + +invalid: + nd_print_invalid(ndo); + ND_TCHECK_LEN(cp, len); +} + +static void +ahcp_ipv4_prefixes_print(netdissect_options *ndo, + const u_char *cp, uint8_t len) +{ + const char *sep = ": "; + + while (len) { + if (len < 5) + goto invalid; + ND_PRINT("%s%s/%u", sep, GET_IPADDR_STRING(cp), GET_U_1(cp + 4)); + cp += 5; + len -= 5; + sep = ", "; + } + return; + +invalid: + nd_print_invalid(ndo); + ND_TCHECK_LEN(cp, len); +} + +static void +(* const data_decoders[AHCP1_OPT_MAX + 1])(netdissect_options *, const u_char *, uint8_t) = { + /* [AHCP1_OPT_PAD] = */ NULL, + /* [AHCP1_OPT_MANDATORY] = */ NULL, + /* [AHCP1_OPT_ORIGIN_TIME] = */ ahcp_time_print, + /* [AHCP1_OPT_EXPIRES] = */ ahcp_seconds_print, + /* [AHCP1_OPT_MY_IPV6_ADDRESS] = */ ahcp_ipv6_addresses_print, + /* [AHCP1_OPT_MY_IPV4_ADDRESS] = */ ahcp_ipv4_addresses_print, + /* [AHCP1_OPT_IPV6_PREFIX] = */ ahcp_ipv6_prefixes_print, + /* [AHCP1_OPT_IPV4_PREFIX] = */ NULL, + /* [AHCP1_OPT_IPV6_ADDRESS] = */ ahcp_ipv6_addresses_print, + /* [AHCP1_OPT_IPV4_ADDRESS] = */ ahcp_ipv4_addresses_print, + /* [AHCP1_OPT_IPV6_PREFIX_DELEGATION] = */ ahcp_ipv6_prefixes_print, + /* [AHCP1_OPT_IPV4_PREFIX_DELEGATION] = */ ahcp_ipv4_prefixes_print, + /* [AHCP1_OPT_NAME_SERVER] = */ ahcp_ipv6_addresses_print, + /* [AHCP1_OPT_NTP_SERVER] = */ ahcp_ipv6_addresses_print, +}; + +static void +ahcp1_options_print(netdissect_options *ndo, + const u_char *cp, uint16_t len) +{ + while (len) { + uint8_t option_no, option_len; + + /* Option no */ + option_no = GET_U_1(cp); + cp += 1; + len -= 1; + ND_PRINT("\n\t %s", tok2str(ahcp1_opt_str, "Unknown-%u", option_no)); + if (option_no == AHCP1_OPT_PAD || option_no == AHCP1_OPT_MANDATORY) + continue; + /* Length */ + if (!len) + goto invalid; + option_len = GET_U_1(cp); + cp += 1; + len -= 1; + if (option_len > len) + goto invalid; + /* Value */ + if (option_no <= AHCP1_OPT_MAX && data_decoders[option_no] != NULL) { + data_decoders[option_no](ndo, cp, option_len); + } else { + ND_PRINT(" (Length %u)", option_len); + ND_TCHECK_LEN(cp, option_len); + } + cp += option_len; + len -= option_len; + } + return; + +invalid: + nd_print_invalid(ndo); + ND_TCHECK_LEN(cp, len); +} + +static void +ahcp1_body_print(netdissect_options *ndo, + const u_char *cp, u_int len) +{ + uint8_t type, mbz; + uint16_t body_len; + + if (len < AHCP1_BODY_MIN_LEN) + goto invalid; + /* Type */ + type = GET_U_1(cp); + cp += 1; + len -= 1; + /* MBZ */ + mbz = GET_U_1(cp); + cp += 1; + len -= 1; + /* Length */ + body_len = GET_BE_U_2(cp); + cp += 2; + len -= 2; + + if (ndo->ndo_vflag) { + ND_PRINT("\n\t%s", tok2str(ahcp1_msg_str, "Unknown-%u", type)); + if (mbz != 0) + ND_PRINT(", MBZ %u", mbz); + ND_PRINT(", Length %u", body_len); + } + if (body_len > len) + goto invalid; + + /* Options */ + /* Here use "body_len", not "len" (ignore any extra data). */ + if (ndo->ndo_vflag >= 2) + ahcp1_options_print(ndo, cp, body_len); + else + ND_TCHECK_LEN(cp, body_len); + return; + +invalid: + nd_print_invalid(ndo); + ND_TCHECK_LEN(cp, len); + +} + +void +ahcp_print(netdissect_options *ndo, + const u_char *cp, u_int len) +{ + uint8_t version; + + ndo->ndo_protocol = "ahcp"; + nd_print_protocol_caps(ndo); + if (len < 2) + goto invalid; + /* Magic */ + if (GET_U_1(cp) != AHCP_MAGIC_NUMBER) + goto invalid; + cp += 1; + len -= 1; + /* Version */ + version = GET_U_1(cp); + cp += 1; + len -= 1; + switch (version) { + case AHCP_VERSION_1: { + ND_PRINT(" Version 1"); + if (len < AHCP1_HEADER_FIX_LEN - 2) + goto invalid; + if (!ndo->ndo_vflag) { + ND_TCHECK_LEN(cp, AHCP1_HEADER_FIX_LEN - 2); + cp += AHCP1_HEADER_FIX_LEN - 2; + len -= AHCP1_HEADER_FIX_LEN - 2; + } else { + /* Hopcount */ + ND_PRINT("\n\tHopcount %u", GET_U_1(cp)); + cp += 1; + len -= 1; + /* Original Hopcount */ + ND_PRINT(", Original Hopcount %u", GET_U_1(cp)); + cp += 1; + len -= 1; + /* Nonce */ + ND_PRINT(", Nonce 0x%08x", GET_BE_U_4(cp)); + cp += 4; + len -= 4; + /* Source Id */ + ND_PRINT(", Source Id %s", GET_LINKADDR_STRING(cp, LINKADDR_OTHER, 8)); + cp += 8; + len -= 8; + /* Destination Id */ + ND_PRINT(", Destination Id %s", GET_LINKADDR_STRING(cp, LINKADDR_OTHER, 8)); + cp += 8; + len -= 8; + } + /* Body */ + ahcp1_body_print(ndo, cp, len); + break; + } + default: + ND_PRINT(" Version %u (unknown)", version); + ND_TCHECK_LEN(cp, len); + break; + } + return; + +invalid: + nd_print_invalid(ndo); + ND_TCHECK_LEN(cp, len); +} |