/* $OpenBSD: print-bgp.c,v 1.4 2002/09/03 12:21:12 ho 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[] = "@(#) $TCPDUMP: /tcpdump/master/tcpdump/print-bgp.c,v 1.27 2001/10/18 09:52:17 itojun 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" 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 /* work in progress */ #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 */ 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 /* RFC1700 address family numbers */ #define AFNUM_INET 1 #define AFNUM_INET6 2 #define AFNUM_NSAP 3 #define AFNUM_HDLC 4 #define AFNUM_BBN1822 5 #define AFNUM_802 6 #define AFNUM_E163 7 #define AFNUM_E164 8 #define AFNUM_F69 9 #define AFNUM_X121 10 #define AFNUM_IPX 11 #define AFNUM_ATALK 12 #define AFNUM_DECNET 13 #define AFNUM_BANYAN 14 #define AFNUM_E164NSAP 15 static const char *afnumber[] = { "Reserved", "IPv4", "IPv6", "NSAP", "HDLC", "BBN 1822", "802", "E.163", "E.164", "F.69", "X.121", "IPX", "Appletalk", "Decnet IV", "Banyan Vines", "E.164 with NSAP subaddress", }; #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; plen = pd[0]; if (plen < 0 || 32 < plen) return -1; memset(&addr, 0, sizeof(addr)); memcpy(&addr, &pd[1], (plen + 7) / 8); if (plen % 8) { ((u_char *)&addr)[(plen + 7) / 8 - 1] &= ((0xff00 >> (plen % 8)) & 0xff); } snprintf(buf, buflen, "%s/%d", getname((u_char *)&addr), plen); return 1 + (plen + 7) / 8; } #ifdef INET6 static int decode_prefix6(const u_char *pd, char *buf, u_int buflen) { struct in6_addr addr; u_int plen; plen = pd[0]; if (plen < 0 || 128 < plen) return -1; memset(&addr, 0, sizeof(addr)); memcpy(&addr, &pd[1], (plen + 7) / 8); if (plen % 8) { addr.s6_addr[(plen + 7) / 8 - 1] &= ((0xff00 >> (plen % 8)) & 0xff); } snprintf(buf, buflen, "%s/%d", getname6((u_char *)&addr), plen); return 1 + (plen + 7) / 8; } #endif static void 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 printf(" %s", bgp_attr_origin(p[0])); break; case BGPTYPE_AS_PATH: if (len % 2) { printf(" invalid len"); 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(" "); if (p[0] == 3 || p[0] == 4) printf("confed"); printf("%s", (p[0] & 1) ? "{" : ""); for (i = 0; i < p[1] * 2; i += 2) { printf("%s%u", i == 0 ? "" : " ", EXTRACT_16BITS(&p[2 + i])); } printf("%s", (p[0] & 1) ? "}" : ""); p += 2 + p[1] * 2; } break; case BGPTYPE_NEXT_HOP: if (len != 4) printf(" invalid len"); else printf(" %s", getname(p)); break; case BGPTYPE_MULTI_EXIT_DISC: case BGPTYPE_LOCAL_PREF: if (len != 4) printf(" invalid len"); else 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; } 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; 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; default: printf(" (AS #%d value 0x%04x)", (comm >> 16) & 0xffff, comm & 0xffff); break; } } break; case BGPTYPE_MP_REACH_NLRI: 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; tlen = p[0]; if (tlen) { printf(" nexthop"); i = 0; while (i < tlen) { switch (af) { case AFNUM_INET: printf(" %s", getname(p + 1 + i)); i += sizeof(struct in_addr); break; #ifdef INET6 case AFNUM_INET6: 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; snpa = p[0]; p++; if (snpa) { printf(" %u snpa", snpa); for (/*nothing*/; snpa > 0; snpa--) { 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)); printf(" %s", buf); break; #ifdef INET6 case AFNUM_INET6: advance = decode_prefix6(p, buf, sizeof(buf)); printf(" %s", buf); break; #endif default: printf(" (unknown af)"); advance = 0; p = dat + len; break; } p += advance; } break; case BGPTYPE_MP_UNREACH_NLRI: 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)); printf(" %s", buf); break; #ifdef INET6 case AFNUM_INET6: advance = decode_prefix6(p, buf, sizeof(buf)); printf(" %s", buf); break; #endif default: printf(" (unknown af)"); advance = 0; p = dat + len; break; } p += advance; } break; default: break; } } static void bgp_open_print(const u_char *dat, int length) { struct bgp_open bgpo; struct bgp_opt bgpopt; int hlen; const u_char *opt; int i; TCHECK2(dat[0], BGP_OPEN_SIZE); memcpy(&bgpo, dat, BGP_OPEN_SIZE); hlen = ntohs(bgpo.bgpo_len); 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; int hlen; const u_char *p; int len; int i; int newline; TCHECK2(dat[0], BGP_SIZE); memcpy(&bgp, dat, BGP_SIZE); hlen = ntohs(bgp.bgp_len); 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]; TCHECK2(p[2], len); i = 2; printf(" (Withdrawn routes:"); while(i < 2 + len) { i += decode_prefix4(&p[i], buf, sizeof(buf)); printf(" %s", buf); } printf(")\n"); #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("]"); } bgp_attr_print(&bgpa, &p[i + aoff], alen); 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)); printf(" %s", buf); if (i < 0) break; p += i; } /* ( */ printf(")"); } return; trunc: printf("[|BGP]"); } static void bgp_notification_print(const u_char *dat, int length) { struct bgp_notification bgpn; int hlen; TCHECK2(dat[0], BGP_NOTIFICATION_SIZE); memcpy(&bgpn, dat, BGP_NOTIFICATION_SIZE); hlen = ntohs(bgpn.bgpn_len); 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 void 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; trunc: printf("[|BGP]"); } 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 < snapend) { 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)) { bgp_header_print(p, hlen); newline = 1; p += hlen; start = p; } else { printf("[|BGP %s]", bgp_type(bgp.bgp_type)); break; } } return; trunc: printf(" [|BGP]"); }