422 lines
16 KiB
C
422 lines
16 KiB
C
/*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that: (1) source code
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* distributions retain the above copyright notice and this paragraph
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* in its entirety, and (2) distributions including binary code include
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* the above copyright notice and this paragraph in its entirety in
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* the documentation or other materials provided with the distribution.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND
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* WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
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* LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE.
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*
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* Original code by Hannes Gredler (hannes@gredler.at)
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*/
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/* \summary: Bidirectional Forwarding Detection (BFD) printer */
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/*
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* specification: draft-ietf-bfd-base-01 for version 0,
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* RFC 5880 for version 1, and RFC 5881
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <netdissect-stdinc.h>
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#include "netdissect.h"
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#include "extract.h"
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#include "udp.h"
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/*
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* Control packet, BFDv0, draft-ietf-bfd-base-01
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*
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* 0 1 2 3
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* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* |Vers | Diag |H|D|P|F|C|A|Rsv| Detect Mult | Length |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | My Discriminator |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Your Discriminator |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Desired Min TX Interval |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Required Min RX Interval |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Required Min Echo RX Interval |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*/
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/*
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* Control packet, BFDv1, RFC 5880
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*
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* 0 1 2 3
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* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* |Vers | Diag |Sta|P|F|C|A|D|M| Detect Mult | Length |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | My Discriminator |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Your Discriminator |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Desired Min TX Interval |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Required Min RX Interval |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Required Min Echo RX Interval |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*/
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struct bfd_header_t {
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uint8_t version_diag;
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uint8_t flags;
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uint8_t detect_time_multiplier;
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uint8_t length;
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uint8_t my_discriminator[4];
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uint8_t your_discriminator[4];
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uint8_t desired_min_tx_interval[4];
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uint8_t required_min_rx_interval[4];
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uint8_t required_min_echo_interval[4];
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};
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/*
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* An optional Authentication Header may be present
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*
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* 0 1 2 3
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* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Auth Type | Auth Len | Authentication Data... |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*/
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struct bfd_auth_header_t {
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uint8_t auth_type;
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uint8_t auth_len;
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uint8_t auth_data;
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uint8_t dummy; /* minimun 4 bytes */
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};
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enum auth_type {
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AUTH_PASSWORD = 1,
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AUTH_MD5 = 2,
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AUTH_MET_MD5 = 3,
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AUTH_SHA1 = 4,
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AUTH_MET_SHA1 = 5
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};
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static const struct tok bfd_v1_authentication_values[] = {
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{ AUTH_PASSWORD, "Simple Password" },
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{ AUTH_MD5, "Keyed MD5" },
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{ AUTH_MET_MD5, "Meticulous Keyed MD5" },
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{ AUTH_SHA1, "Keyed SHA1" },
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{ AUTH_MET_SHA1, "Meticulous Keyed SHA1" },
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{ 0, NULL }
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};
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enum auth_length {
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AUTH_PASSWORD_FIELD_MIN_LEN = 4, /* header + password min: 3 + 1 */
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AUTH_PASSWORD_FIELD_MAX_LEN = 19, /* header + password max: 3 + 16 */
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AUTH_MD5_FIELD_LEN = 24,
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AUTH_MD5_HASH_LEN = 16,
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AUTH_SHA1_FIELD_LEN = 28,
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AUTH_SHA1_HASH_LEN = 20
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};
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#define BFD_EXTRACT_VERSION(x) (((x)&0xe0)>>5)
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#define BFD_EXTRACT_DIAG(x) ((x)&0x1f)
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static const struct tok bfd_diag_values[] = {
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{ 0, "No Diagnostic" },
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{ 1, "Control Detection Time Expired" },
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{ 2, "Echo Function Failed" },
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{ 3, "Neighbor Signaled Session Down" },
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{ 4, "Forwarding Plane Reset" },
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{ 5, "Path Down" },
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{ 6, "Concatenated Path Down" },
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{ 7, "Administratively Down" },
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{ 8, "Reverse Concatenated Path Down" },
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{ 0, NULL }
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};
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#define BFD_FLAG_AUTH 0x04
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static const struct tok bfd_v0_flag_values[] = {
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{ 0x80, "I Hear You" },
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{ 0x40, "Demand" },
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{ 0x20, "Poll" },
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{ 0x10, "Final" },
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{ 0x08, "Control Plane Independent" },
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{ BFD_FLAG_AUTH, "Authentication Present" },
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{ 0x02, "Reserved" },
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{ 0x01, "Reserved" },
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{ 0, NULL }
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};
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static const struct tok bfd_v1_flag_values[] = {
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{ 0x20, "Poll" },
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{ 0x10, "Final" },
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{ 0x08, "Control Plane Independent" },
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{ BFD_FLAG_AUTH, "Authentication Present" },
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{ 0x02, "Demand" },
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{ 0x01, "Multipoint" },
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{ 0, NULL }
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};
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static const struct tok bfd_v1_state_values[] = {
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{ 0, "AdminDown" },
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{ 1, "Down" },
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{ 2, "Init" },
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{ 3, "Up" },
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{ 0, NULL }
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};
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static int
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auth_print(netdissect_options *ndo, register const u_char *pptr)
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{
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const struct bfd_auth_header_t *bfd_auth_header;
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int i;
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pptr += sizeof (const struct bfd_header_t);
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bfd_auth_header = (const struct bfd_auth_header_t *)pptr;
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ND_TCHECK(*bfd_auth_header);
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ND_PRINT((ndo, "\n\tAuthentication: %s (%u), length: %u",
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tok2str(bfd_v1_authentication_values,"Unknown",bfd_auth_header->auth_type),
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bfd_auth_header->auth_type,
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bfd_auth_header->auth_len));
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pptr += 2;
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ND_PRINT((ndo, "\n\t Auth Key ID: %d", *pptr));
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switch(bfd_auth_header->auth_type) {
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case AUTH_PASSWORD:
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/*
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* Simple Password Authentication Section Format
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*
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* 0 1 2 3
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* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Auth Type | Auth Len | Auth Key ID | Password... |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | ... |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*/
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if (bfd_auth_header->auth_len < AUTH_PASSWORD_FIELD_MIN_LEN ||
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bfd_auth_header->auth_len > AUTH_PASSWORD_FIELD_MAX_LEN) {
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ND_PRINT((ndo, "[invalid length %d]",
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bfd_auth_header->auth_len));
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break;
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}
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pptr++;
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ND_PRINT((ndo, ", Password: "));
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/* the length is equal to the password length plus three */
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if (fn_printn(ndo, pptr, bfd_auth_header->auth_len - 3,
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ndo->ndo_snapend))
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goto trunc;
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break;
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case AUTH_MD5:
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case AUTH_MET_MD5:
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/*
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* Keyed MD5 and Meticulous Keyed MD5 Authentication Section Format
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*
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* 0 1 2 3
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* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Auth Type | Auth Len | Auth Key ID | Reserved |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Sequence Number |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Auth Key/Digest... |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | ... |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*/
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if (bfd_auth_header->auth_len != AUTH_MD5_FIELD_LEN) {
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ND_PRINT((ndo, "[invalid length %d]",
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bfd_auth_header->auth_len));
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break;
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}
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pptr += 2;
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ND_TCHECK2(*pptr, 4);
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ND_PRINT((ndo, ", Sequence Number: 0x%08x", EXTRACT_32BITS(pptr)));
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pptr += 4;
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ND_TCHECK2(*pptr, AUTH_MD5_HASH_LEN);
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ND_PRINT((ndo, "\n\t Digest: "));
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for(i = 0; i < AUTH_MD5_HASH_LEN; i++)
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ND_PRINT((ndo, "%02x", pptr[i]));
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break;
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case AUTH_SHA1:
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case AUTH_MET_SHA1:
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/*
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* Keyed SHA1 and Meticulous Keyed SHA1 Authentication Section Format
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*
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* 0 1 2 3
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* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Auth Type | Auth Len | Auth Key ID | Reserved |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Sequence Number |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Auth Key/Hash... |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | ... |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*/
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if (bfd_auth_header->auth_len != AUTH_SHA1_FIELD_LEN) {
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ND_PRINT((ndo, "[invalid length %d]",
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bfd_auth_header->auth_len));
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break;
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}
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pptr += 2;
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ND_TCHECK2(*pptr, 4);
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ND_PRINT((ndo, ", Sequence Number: 0x%08x", EXTRACT_32BITS(pptr)));
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pptr += 4;
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ND_TCHECK2(*pptr, AUTH_SHA1_HASH_LEN);
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ND_PRINT((ndo, "\n\t Hash: "));
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for(i = 0; i < AUTH_SHA1_HASH_LEN; i++)
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ND_PRINT((ndo, "%02x", pptr[i]));
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break;
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}
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return 0;
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trunc:
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return 1;
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}
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void
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bfd_print(netdissect_options *ndo, register const u_char *pptr,
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register u_int len, register u_int port)
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{
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if (port == BFD_CONTROL_PORT) {
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/*
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* Control packet.
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*/
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const struct bfd_header_t *bfd_header;
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uint8_t version_diag;
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uint8_t version = 0;
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uint8_t flags;
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bfd_header = (const struct bfd_header_t *)pptr;
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ND_TCHECK(*bfd_header);
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version_diag = bfd_header->version_diag;
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version = BFD_EXTRACT_VERSION(version_diag);
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flags = bfd_header->flags;
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switch (version) {
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/* BFDv0 */
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case 0:
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if (ndo->ndo_vflag < 1)
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{
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ND_PRINT((ndo, "BFDv0, Control, Flags: [%s], length: %u",
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bittok2str(bfd_v0_flag_values, "none", flags),
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len));
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return;
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}
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ND_PRINT((ndo, "BFDv0, length: %u\n\tControl, Flags: [%s], Diagnostic: %s (0x%02x)",
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len,
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bittok2str(bfd_v0_flag_values, "none", flags),
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tok2str(bfd_diag_values,"unknown",BFD_EXTRACT_DIAG(version_diag)),
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BFD_EXTRACT_DIAG(version_diag)));
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ND_PRINT((ndo, "\n\tDetection Timer Multiplier: %u (%u ms Detection time), BFD Length: %u",
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bfd_header->detect_time_multiplier,
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bfd_header->detect_time_multiplier * EXTRACT_32BITS(bfd_header->desired_min_tx_interval)/1000,
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bfd_header->length));
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ND_PRINT((ndo, "\n\tMy Discriminator: 0x%08x", EXTRACT_32BITS(bfd_header->my_discriminator)));
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ND_PRINT((ndo, ", Your Discriminator: 0x%08x", EXTRACT_32BITS(bfd_header->your_discriminator)));
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ND_PRINT((ndo, "\n\t Desired min Tx Interval: %4u ms", EXTRACT_32BITS(bfd_header->desired_min_tx_interval)/1000));
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ND_PRINT((ndo, "\n\t Required min Rx Interval: %4u ms", EXTRACT_32BITS(bfd_header->required_min_rx_interval)/1000));
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ND_PRINT((ndo, "\n\t Required min Echo Interval: %4u ms", EXTRACT_32BITS(bfd_header->required_min_echo_interval)/1000));
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if (flags & BFD_FLAG_AUTH) {
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if (auth_print(ndo, pptr))
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goto trunc;
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}
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break;
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/* BFDv1 */
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case 1:
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if (ndo->ndo_vflag < 1)
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{
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ND_PRINT((ndo, "BFDv1, Control, State %s, Flags: [%s], length: %u",
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tok2str(bfd_v1_state_values, "unknown (%u)", (flags & 0xc0) >> 6),
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bittok2str(bfd_v1_flag_values, "none", flags & 0x3f),
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len));
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return;
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}
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ND_PRINT((ndo, "BFDv1, length: %u\n\tControl, State %s, Flags: [%s], Diagnostic: %s (0x%02x)",
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len,
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tok2str(bfd_v1_state_values, "unknown (%u)", (flags & 0xc0) >> 6),
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bittok2str(bfd_v1_flag_values, "none", flags & 0x3f),
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tok2str(bfd_diag_values,"unknown",BFD_EXTRACT_DIAG(version_diag)),
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BFD_EXTRACT_DIAG(version_diag)));
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ND_PRINT((ndo, "\n\tDetection Timer Multiplier: %u (%u ms Detection time), BFD Length: %u",
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bfd_header->detect_time_multiplier,
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bfd_header->detect_time_multiplier * EXTRACT_32BITS(bfd_header->desired_min_tx_interval)/1000,
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bfd_header->length));
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ND_PRINT((ndo, "\n\tMy Discriminator: 0x%08x", EXTRACT_32BITS(bfd_header->my_discriminator)));
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ND_PRINT((ndo, ", Your Discriminator: 0x%08x", EXTRACT_32BITS(bfd_header->your_discriminator)));
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ND_PRINT((ndo, "\n\t Desired min Tx Interval: %4u ms", EXTRACT_32BITS(bfd_header->desired_min_tx_interval)/1000));
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ND_PRINT((ndo, "\n\t Required min Rx Interval: %4u ms", EXTRACT_32BITS(bfd_header->required_min_rx_interval)/1000));
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ND_PRINT((ndo, "\n\t Required min Echo Interval: %4u ms", EXTRACT_32BITS(bfd_header->required_min_echo_interval)/1000));
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if (flags & BFD_FLAG_AUTH) {
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if (auth_print(ndo, pptr))
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goto trunc;
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}
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break;
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default:
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ND_PRINT((ndo, "BFDv%u, Control, length: %u",
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version,
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len));
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if (ndo->ndo_vflag >= 1) {
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if(!print_unknown_data(ndo, pptr,"\n\t",len))
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return;
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}
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break;
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}
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} else if (port == BFD_ECHO_PORT) {
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/*
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* Echo packet.
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*/
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ND_PRINT((ndo, "BFD, Echo, length: %u",
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len));
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if (ndo->ndo_vflag >= 1) {
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if(!print_unknown_data(ndo, pptr,"\n\t",len))
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return;
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}
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} else {
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/*
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* Unknown packet type.
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*/
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ND_PRINT((ndo, "BFD, unknown (%u), length: %u",
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port,
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len));
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if (ndo->ndo_vflag >= 1) {
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if(!print_unknown_data(ndo, pptr,"\n\t",len))
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return;
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}
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}
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return;
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trunc:
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ND_PRINT((ndo, "[|BFD]"));
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}
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/*
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* Local Variables:
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* c-style: whitesmith
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* c-basic-offset: 8
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* End:
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*/
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