OpenBSD-4.6/usr.sbin/tcpdump/print-bgp.c
/* $OpenBSD: print-bgp.c,v 1.11 2009/01/29 09:46:32 bluhm Exp $ */
/*
* Copyright (C) 1999 WIDE 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.
* 3. Neither the name of the project 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 BY THE PROJECT 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 PROJECT 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.
*/
#ifndef lint
static const char rcsid[] =
"@(#) $Id: print-bgp.c,v 1.11 2009/01/29 09:46:32 bluhm Exp $";
#endif
#include <sys/param.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <netdb.h>
#include "interface.h"
#include "addrtoname.h"
#include "extract.h"
#include "afnum.h"
struct bgp {
u_int8_t bgp_marker[16];
u_int16_t bgp_len;
u_int8_t bgp_type;
};
#define BGP_SIZE 19 /* unaligned */
#define BGP_OPEN 1
#define BGP_UPDATE 2
#define BGP_NOTIFICATION 3
#define BGP_KEEPALIVE 4
struct bgp_open {
u_int8_t bgpo_marker[16];
u_int16_t bgpo_len;
u_int8_t bgpo_type;
u_int8_t bgpo_version;
u_int16_t bgpo_myas;
u_int16_t bgpo_holdtime;
u_int32_t bgpo_id;
u_int8_t bgpo_optlen;
/* options should follow */
};
#define BGP_OPEN_SIZE 29 /* unaligned */
struct bgp_opt {
u_int8_t bgpopt_type;
u_int8_t bgpopt_len;
/* variable length */
};
#define BGP_OPT_SIZE 2 /* some compilers may pad to 4 bytes */
struct bgp_notification {
u_int8_t bgpn_marker[16];
u_int16_t bgpn_len;
u_int8_t bgpn_type;
u_int8_t bgpn_major;
u_int8_t bgpn_minor;
/* data should follow */
};
#define BGP_NOTIFICATION_SIZE 21 /* unaligned */
struct bgp_attr {
u_int8_t bgpa_flags;
u_int8_t bgpa_type;
union {
u_int8_t len;
u_int16_t elen;
} bgpa_len;
#define bgp_attr_len(p) \
(((p)->bgpa_flags & 0x10) ? \
ntohs((p)->bgpa_len.elen) : (p)->bgpa_len.len)
#define bgp_attr_off(p) \
(((p)->bgpa_flags & 0x10) ? 4 : 3)
};
#define BGPTYPE_ORIGIN 1
#define BGPTYPE_AS_PATH 2
#define BGPTYPE_NEXT_HOP 3
#define BGPTYPE_MULTI_EXIT_DISC 4
#define BGPTYPE_LOCAL_PREF 5
#define BGPTYPE_ATOMIC_AGGREGATE 6
#define BGPTYPE_AGGREGATOR 7
#define BGPTYPE_COMMUNITIES 8 /* RFC1997 */
#define BGPTYPE_ORIGINATOR_ID 9 /* RFC1998 */
#define BGPTYPE_CLUSTER_LIST 10 /* RFC1998 */
#define BGPTYPE_DPA 11 /* draft-ietf-idr-bgp-dpa */
#define BGPTYPE_ADVERTISERS 12 /* RFC1863 */
#define BGPTYPE_RCID_PATH 13 /* RFC1863 */
#define BGPTYPE_MP_REACH_NLRI 14 /* RFC2283 */
#define BGPTYPE_MP_UNREACH_NLRI 15 /* RFC2283 */
#define BGP_MP_NLRI_MINSIZE 3
static const char *bgptype[] = {
NULL, "OPEN", "UPDATE", "NOTIFICATION", "KEEPALIVE",
};
#define bgp_type(x) num_or_str(bgptype, sizeof(bgptype)/sizeof(bgptype[0]), (x))
static const char *bgpopt_type[] = {
NULL, "Authentication Information", "Capabilities Advertisement",
};
#define bgp_opttype(x) \
num_or_str(bgpopt_type, sizeof(bgpopt_type)/sizeof(bgpopt_type[0]), (x))
static const char *bgpnotify_major[] = {
NULL, "Message Header Error",
"OPEN Message Error", "UPDATE Message Error",
"Hold Timer Expired", "Finite State Machine Error",
"Cease",
};
#define bgp_notify_major(x) \
num_or_str(bgpnotify_major, \
sizeof(bgpnotify_major)/sizeof(bgpnotify_major[0]), (x))
static const char *bgpnotify_minor_1[] = {
NULL, "Connection Not Synchronized",
"Bad Message Length", "Bad Message Type",
};
static const char *bgpnotify_minor_2[] = {
NULL, "Unsupported Version Number",
"Bad Peer AS", "Bad BGP Identifier",
"Unsupported Optional Parameter", "Authentication Failure",
"Unacceptable Hold Time",
};
static const char *bgpnotify_minor_3[] = {
NULL, "Malformed Attribute List",
"Unrecognized Well-known Attribute", "Missing Well-known Attribute",
"Attribute Flags Error", "Attribute Length Error",
"Invalid ORIGIN Attribute", "AS Routing Loop",
"Invalid NEXT_HOP Attribute", "Optional Attribute Error",
"Invalid Network Field", "Malformed AS_PATH",
};
static const char **bgpnotify_minor[] = {
NULL, bgpnotify_minor_1, bgpnotify_minor_2, bgpnotify_minor_3,
};
static const int bgpnotify_minor_siz[] = {
0, sizeof(bgpnotify_minor_1)/sizeof(bgpnotify_minor_1[0]),
sizeof(bgpnotify_minor_2)/sizeof(bgpnotify_minor_2[0]),
sizeof(bgpnotify_minor_3)/sizeof(bgpnotify_minor_3[0]),
};
static const char *bgpattr_origin[] = {
"IGP", "EGP", "INCOMPLETE",
};
#define bgp_attr_origin(x) \
num_or_str(bgpattr_origin, \
sizeof(bgpattr_origin)/sizeof(bgpattr_origin[0]), (x))
static const char *bgpattr_type[] = {
NULL, "ORIGIN", "AS_PATH", "NEXT_HOP",
"MULTI_EXIT_DISC", "LOCAL_PREF", "ATOMIC_AGGREGATE", "AGGREGATOR",
"COMMUNITIES", "ORIGINATOR_ID", "CLUSTER_LIST", "DPA",
"ADVERTISERS", "RCID_PATH", "MP_REACH_NLRI", "MP_UNREACH_NLRI",
};
#define bgp_attr_type(x) \
num_or_str(bgpattr_type, \
sizeof(bgpattr_type)/sizeof(bgpattr_type[0]), (x))
/* Subsequent address family identifier, RFC2283 section 7 */
static const char *bgpattr_nlri_safi[] = {
"Reserved", "Unicast", "Multicast", "Unicast+Multicast",
};
#define bgp_attr_nlri_safi(x) \
num_or_str(bgpattr_nlri_safi, \
sizeof(bgpattr_nlri_safi)/sizeof(bgpattr_nlri_safi[0]), (x))
/* well-known community */
#define BGP_COMMUNITY_NO_EXPORT 0xffffff01
#define BGP_COMMUNITY_NO_ADVERT 0xffffff02
#define BGP_COMMUNITY_NO_EXPORT_SUBCONFED 0xffffff03
#define BGP_COMMUNITY_NO_PEER 0xffffff04
static const char *afnumber[] = AFNUM_NAME_STR;
#define af_name(x) \
(((x) == 65535) ? afnumber[0] : \
num_or_str(afnumber, \
sizeof(afnumber)/sizeof(afnumber[0]), (x)))
static const char *
num_or_str(const char **table, size_t siz, int value)
{
static char buf[20];
if (value < 0 || siz <= value || table[value] == NULL) {
snprintf(buf, sizeof(buf), "#%d", value);
return buf;
} else
return table[value];
}
static const char *
bgp_notify_minor(int major, int minor)
{
static const char **table;
int siz;
static char buf[20];
const char *p;
if (0 <= major
&& major < sizeof(bgpnotify_minor)/sizeof(bgpnotify_minor[0])
&& bgpnotify_minor[major]) {
table = bgpnotify_minor[major];
siz = bgpnotify_minor_siz[major];
if (0 <= minor && minor < siz && table[minor])
p = table[minor];
else
p = NULL;
} else
p = NULL;
if (p == NULL) {
snprintf(buf, sizeof(buf), "#%d", minor);
return buf;
} else
return p;
}
static int
decode_prefix4(const u_char *pd, char *buf, u_int buflen)
{
struct in_addr addr;
u_int plen;
int n;
TCHECK(pd[0]);
plen = pd[0]; /*
* prefix length is in bits; packet only contains
* enough bytes of address to contain this many bits
*/
if (plen < 0 || 32 < plen)
return -1;
memset(&addr, 0, sizeof(addr));
TCHECK2(pd[1], (plen + 7) / 8);
memcpy(&addr, &pd[1], (plen + 7) / 8);
if (plen % 8) {
((u_char *)&addr)[(plen + 7) / 8 - 1] &=
((0xff00 >> (plen % 8)) & 0xff);
}
n = snprintf(buf, buflen, "%s/%d", getname((u_char *)&addr), plen);
if (n == -1 || n >= buflen)
return -1;
return 1 + (plen + 7) / 8;
trunc:
return -2;
}
#ifdef INET6
static int
decode_prefix6(const u_char *pd, char *buf, u_int buflen)
{
struct in6_addr addr;
u_int plen;
int n;
TCHECK(pd[0]);
plen = pd[0];
if (plen < 0 || 128 < plen)
return -1;
memset(&addr, 0, sizeof(addr));
TCHECK2(pd[1], (plen + 7) / 8);
memcpy(&addr, &pd[1], (plen + 7) / 8);
if (plen % 8) {
addr.s6_addr[(plen + 7) / 8 - 1] &=
((0xff00 >> (plen % 8)) & 0xff);
}
n = snprintf(buf, buflen, "%s/%d", getname6((u_char *)&addr), plen);
if (n == -1 || n >= buflen)
return -1;
return 1 + (plen + 7) / 8;
trunc:
return -2;
}
#endif
static int
bgp_attr_print(const struct bgp_attr *attr, const u_char *dat, int len)
{
int i;
u_int16_t af;
u_int8_t safi, snpa;
int advance;
int tlen;
const u_char *p;
char buf[MAXHOSTNAMELEN + 100];
p = dat;
switch (attr->bgpa_type) {
case BGPTYPE_ORIGIN:
if (len != 1)
printf(" invalid len");
else {
TCHECK(p[0]);
printf(" %s", bgp_attr_origin(p[0]));
}
break;
case BGPTYPE_AS_PATH:
if (len % 2) {
printf(" invalid len");
break;
}
if (!len) {
printf(" empty");
break;
}
while (p < dat + len) {
/*
* under RFC1965, p[0] means:
* 1: AS_SET 2: AS_SEQUENCE
* 3: AS_CONFED_SET 4: AS_CONFED_SEQUENCE
*/
printf(" ");
TCHECK(p[1]);
if (p[0] == 3 || p[0] == 4)
printf("confed");
printf("%s", (p[0] & 1) ? "{" : "");
for (i = 0; i < p[1] * 2; i += 2) {
TCHECK2(p[2 + i], 2); /* ASN is 2-bytes */
printf("%s%u", i == 0 ? "" : " ",
EXTRACT_16BITS(&p[2 + i]));
}
printf("%s", (p[0] & 1) ? "}" : "");
/*
* 1 byte for attr type, 1 byte for path length,
* plus size of ASN (2-bytes for now) * no of ASN
*
*/
p += 2 + p[1] * 2;
}
break;
case BGPTYPE_NEXT_HOP:
if (len != 4)
printf(" invalid len");
else {
TCHECK2(p[0], 4);
printf(" %s", getname(p));
}
break;
case BGPTYPE_MULTI_EXIT_DISC:
case BGPTYPE_LOCAL_PREF:
if (len != 4)
printf(" invalid len");
else {
TCHECK2(p[0], 4);
printf(" %u", EXTRACT_32BITS(p));
}
break;
case BGPTYPE_ATOMIC_AGGREGATE:
if (len != 0)
printf(" invalid len");
break;
case BGPTYPE_AGGREGATOR:
if (len != 6) {
printf(" invalid len");
break;
}
TCHECK2(p[0], 6);
printf(" AS #%u, origin %s", EXTRACT_16BITS(p),
getname(p + 2));
break;
case BGPTYPE_COMMUNITIES:
if (len % 4) {
printf(" invalid len");
break;
}
for (i = 0; i < len; i += 4) {
u_int32_t comm;
TCHECK2(p[i], 4);
comm = EXTRACT_32BITS(&p[i]);
switch (comm) {
case BGP_COMMUNITY_NO_EXPORT:
printf(" NO_EXPORT");
break;
case BGP_COMMUNITY_NO_ADVERT:
printf(" NO_ADVERTISE");
break;
case BGP_COMMUNITY_NO_EXPORT_SUBCONFED:
printf(" NO_EXPORT_SUBCONFED");
break;
case BGP_COMMUNITY_NO_PEER:
printf(" NO_PEER");
break;
default:
printf(" %d:%d",
(comm >> 16) & 0xffff, comm & 0xffff);
break;
}
}
break;
case BGPTYPE_MP_REACH_NLRI:
TCHECK2(p[0], BGP_MP_NLRI_MINSIZE);
af = EXTRACT_16BITS(p);
safi = p[2];
if (safi >= 128)
printf(" %s vendor specific,", af_name(af));
else {
printf(" %s %s,", af_name(af),
bgp_attr_nlri_safi(safi));
}
p += 3;
if (af == AFNUM_INET)
;
#ifdef INET6
else if (af == AFNUM_INET6)
;
#endif
else
break;
TCHECK(p[0]);
tlen = p[0];
if (tlen) {
printf(" nexthop");
i = 0;
while (i < tlen) {
switch (af) {
case AFNUM_INET:
TCHECK2(p[1+i], sizeof(struct in_addr));
printf(" %s", getname(p + 1 + i));
i += sizeof(struct in_addr);
break;
#ifdef INET6
case AFNUM_INET6:
TCHECK2(p[1+i], sizeof(struct in6_addr));
printf(" %s", getname6(p + 1 + i));
i += sizeof(struct in6_addr);
break;
#endif
default:
printf(" (unknown af)");
i = tlen; /*exit loop*/
break;
}
}
printf(",");
}
p += 1 + tlen;
TCHECK(p[0]);
snpa = p[0];
p++;
if (snpa) {
printf(" %u snpa", snpa);
for (/*nothing*/; snpa > 0; snpa--) {
TCHECK(p[0]);
printf("(%d bytes)", p[0]);
p += p[0] + 1;
}
printf(",");
}
printf(" NLRI");
while (len - (p - dat) > 0) {
switch (af) {
case AFNUM_INET:
advance = decode_prefix4(p, buf, sizeof(buf));
break;
#ifdef INET6
case AFNUM_INET6:
advance = decode_prefix6(p, buf, sizeof(buf));
break;
#endif
default:
printf(" (unknown af)");
advance = 0;
p = dat + len;
break;
}
if (advance <= 0)
break;
printf(" %s", buf);
p += advance;
}
break;
case BGPTYPE_MP_UNREACH_NLRI:
TCHECK2(p[0], BGP_MP_NLRI_MINSIZE);
af = EXTRACT_16BITS(p);
safi = p[2];
if (safi >= 128)
printf(" %s vendor specific,", af_name(af));
else {
printf(" %s %s,", af_name(af),
bgp_attr_nlri_safi(safi));
}
p += 3;
printf(" Withdraw");
while (len - (p - dat) > 0) {
switch (af) {
case AFNUM_INET:
advance = decode_prefix4(p, buf, sizeof(buf));
break;
#ifdef INET6
case AFNUM_INET6:
advance = decode_prefix6(p, buf, sizeof(buf));
break;
#endif
default:
printf(" (unknown af)");
advance = 0;
p = dat + len;
break;
}
if (advance <= 0)
break;
printf(" %s", buf);
p += advance;
}
break;
default:
break;
}
return 1;
trunc:
return 0;
}
static void
bgp_open_print(const u_char *dat, int length)
{
struct bgp_open bgpo;
struct bgp_opt bgpopt;
const u_char *opt;
int i;
TCHECK2(dat[0], BGP_OPEN_SIZE);
memcpy(&bgpo, dat, BGP_OPEN_SIZE);
printf(": Version %d,", bgpo.bgpo_version);
printf(" AS #%u,", ntohs(bgpo.bgpo_myas));
printf(" Holdtime %u,", ntohs(bgpo.bgpo_holdtime));
printf(" ID %s,", getname((u_char *)&bgpo.bgpo_id));
printf(" Option length %u", bgpo.bgpo_optlen);
/* ugly! */
opt = &((const struct bgp_open *)dat)->bgpo_optlen;
opt++;
i = 0;
while (i < bgpo.bgpo_optlen) {
TCHECK2(opt[i], BGP_OPT_SIZE);
memcpy(&bgpopt, &opt[i], BGP_OPT_SIZE);
if (i + 2 + bgpopt.bgpopt_len > bgpo.bgpo_optlen) {
printf(" [|opt %d %d]", bgpopt.bgpopt_len, bgpopt.bgpopt_type);
break;
}
printf(" (option %s, len=%d)", bgp_opttype(bgpopt.bgpopt_type),
bgpopt.bgpopt_len);
i += BGP_OPT_SIZE + bgpopt.bgpopt_len;
}
return;
trunc:
printf("[|BGP]");
}
static void
bgp_update_print(const u_char *dat, int length)
{
struct bgp bgp;
struct bgp_attr bgpa;
const u_char *p;
int len;
int i;
int newline;
TCHECK2(dat[0], BGP_SIZE);
memcpy(&bgp, dat, BGP_SIZE);
p = dat + BGP_SIZE; /*XXX*/
printf(":");
/* Unfeasible routes */
len = EXTRACT_16BITS(p);
if (len) {
/*
* Without keeping state from the original NLRI message,
* it's not possible to tell if this a v4 or v6 route,
* so only try to decode it if we're not v6 enabled.
*/
#ifdef INET6
printf(" (Withdrawn routes: %d bytes)", len);
#else
char buf[MAXHOSTNAMELEN + 100];
int wpfx;
TCHECK2(p[2], len);
i = 2;
printf(" (Withdrawn routes:");
while(i < 2 + len) {
wpfx = decode_prefix4(&p[i], buf, sizeof(buf));
if (wpfx == -2)
goto trunc;
else if (wpfx < 0) {
printf(" (illegal prefix length)");
break;
}
i += wpfx;
printf(" %s", buf);
}
printf(")");
#endif
}
p += 2 + len;
TCHECK2(p[0], 2);
len = EXTRACT_16BITS(p);
if (len) {
/* do something more useful!*/
i = 2;
printf(" (Path attributes:"); /* ) */
newline = 0;
while (i < 2 + len) {
int alen, aoff;
TCHECK2(p[i], sizeof(bgpa));
memcpy(&bgpa, &p[i], sizeof(bgpa));
alen = bgp_attr_len(&bgpa);
aoff = bgp_attr_off(&bgpa);
if (vflag && newline)
printf("\n\t\t");
else
printf(" ");
printf("("); /* ) */
printf("%s", bgp_attr_type(bgpa.bgpa_type));
if (bgpa.bgpa_flags) {
printf("[%s%s%s%s",
bgpa.bgpa_flags & 0x80 ? "O" : "",
bgpa.bgpa_flags & 0x40 ? "T" : "",
bgpa.bgpa_flags & 0x20 ? "P" : "",
bgpa.bgpa_flags & 0x10 ? "E" : "");
if (bgpa.bgpa_flags & 0xf)
printf("+%x", bgpa.bgpa_flags & 0xf);
printf("]");
}
if (!bgp_attr_print(&bgpa, &p[i + aoff], alen))
goto trunc;
newline = 1;
/* ( */
printf(")");
i += aoff + alen;
}
/* ( */
printf(")");
}
p += 2 + len;
if (len && dat + length > p)
printf("\n\t\t");
if (dat + length > p) {
printf("(NLRI:"); /* ) */
while (dat + length > p) {
char buf[MAXHOSTNAMELEN + 100];
i = decode_prefix4(p, buf, sizeof(buf));
if (i == -2)
goto trunc;
else if (i < 0) {
printf(" (illegal prefix length)");
break;
}
printf(" %s", buf);
p += i;
}
/* ( */
printf(")");
}
return;
trunc:
printf("[|BGP]");
}
static void
bgp_notification_print(const u_char *dat, int length)
{
struct bgp_notification bgpn;
TCHECK2(dat[0], BGP_NOTIFICATION_SIZE);
memcpy(&bgpn, dat, BGP_NOTIFICATION_SIZE);
printf(": error %s,", bgp_notify_major(bgpn.bgpn_major));
printf(" subcode %s",
bgp_notify_minor(bgpn.bgpn_major, bgpn.bgpn_minor));
return;
trunc:
printf("[|BGP]");
}
static int
bgp_header_print(const u_char *dat, int length)
{
struct bgp bgp;
TCHECK2(dat[0], BGP_SIZE);
memcpy(&bgp, dat, BGP_SIZE);
printf("(%s", bgp_type(bgp.bgp_type)); /* ) */
switch (bgp.bgp_type) {
case BGP_OPEN:
bgp_open_print(dat, length);
break;
case BGP_UPDATE:
bgp_update_print(dat, length);
break;
case BGP_NOTIFICATION:
bgp_notification_print(dat, length);
break;
}
/* ( */
printf(")");
return 1;
trunc:
printf("[|BGP]");
return 0;
}
void
bgp_print(const u_char *dat, int length)
{
const u_char *p;
const u_char *ep;
const u_char *start;
const u_char marker[] = {
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
};
struct bgp bgp;
u_int16_t hlen;
int newline;
ep = dat + length;
if (snapend < dat + length)
ep = snapend;
printf(": BGP");
p = dat;
newline = 0;
start = p;
while (p < ep) {
if (!TTEST2(p[0], 1))
break;
if (p[0] != 0xff) {
p++;
continue;
}
if (!TTEST2(p[0], sizeof(marker)))
break;
if (memcmp(p, marker, sizeof(marker)) != 0) {
p++;
continue;
}
/* found BGP header */
TCHECK2(p[0], BGP_SIZE); /*XXX*/
memcpy(&bgp, p, BGP_SIZE);
if (start != p)
printf(" [|BGP]");
hlen = ntohs(bgp.bgp_len);
if (vflag && newline)
printf("\n\t");
else
printf(" ");
if (TTEST2(p[0], hlen)) {
if (!bgp_header_print(p, hlen))
return;
newline = 1;
p += hlen;
start = p;
} else {
printf("[|BGP %s]", bgp_type(bgp.bgp_type));
break;
}
}
return;
trunc:
printf(" [|BGP]");
}