/* $OpenBSD: print-bgp.c,v 1.32 2022/05/25 16:21:11 claudio 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. */ #include #include #include #include #include #include #include #include #include #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 #define BGP_ROUTE_REFRESH 5 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_CAP 2 #define BGP_OPT_SIZE 2 /* some compilers may pad to 4 bytes */ #define BGP_UPDATE_MINSIZE 23 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_route_refresh { u_int8_t bgp_marker[16]; u_int16_t len; u_int8_t type; u_int8_t afi[2]; /* unaligned; should be u_int16_t */ u_int8_t subtype; u_int8_t safi; }; #define BGP_ROUTE_REFRESH_SIZE 23 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 BGPTYPE_EXTD_COMMUNITIES 16 /* RFC4360 */ #define BGPTYPE_AS4_PATH 17 /* RFC4893 */ #define BGPTYPE_AGGREGATOR4 18 /* RFC4893 */ #define BGPTYPE_LARGE_COMMUNITIES 32 /* RFC8092 */ #define BGPTYPE_ONLY_TO_CUSTOMER 35 /* RFC9234 */ #define BGP_AS_SET 1 #define BGP_AS_SEQUENCE 2 #define BGP_CONFED_AS_SEQUENCE 3 /* draft-ietf-idr-rfc3065bis-01 */ #define BGP_CONFED_AS_SET 4 /* draft-ietf-idr-rfc3065bis-01 */ static struct tok bgp_as_path_segment_open_values[] = { { BGP_AS_SET, " {" }, { BGP_AS_SEQUENCE, " " }, { BGP_CONFED_AS_SEQUENCE, " (" }, { BGP_CONFED_AS_SET, " ({" }, { 0, NULL}, }; static struct tok bgp_as_path_segment_close_values[] = { { BGP_AS_SET, "}" }, { BGP_AS_SEQUENCE, "" }, { BGP_CONFED_AS_SEQUENCE, ")" }, { BGP_CONFED_AS_SET, "})" }, { 0, NULL}, }; #define BGP_MP_NLRI_MINSIZE 3 static const char *bgptype[] = { NULL, "OPEN", "UPDATE", "NOTIFICATION", "KEEPALIVE", "ROUTE-REFRESH", }; #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)) #define BGP_CAPCODE_MP 1 #define BGP_CAPCODE_REFRESH 2 #define BGP_CAPCODE_BGPROLE 9 /* RFC9234 */ #define BGP_CAPCODE_RESTART 64 /* RFC4724 */ #define BGP_CAPCODE_AS4 65 /* RFC4893 */ static const char *bgp_capcode[] = { NULL, "MULTI_PROTOCOL", "ROUTE_REFRESH", /* 3: RFC5291 */ "OUTBOUND_ROUTE_FILTERING", /* 4: RFC3107 */ "MULTIPLE_ROUTES", /* 5: RFC5549 */ "EXTENDED_NEXTHOP_ENCODING", 0, 0, 0, /* 9: RFC9234 */ "BGP_ROLE", 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 64: RFC4724 */ "GRACEFUL_RESTART", /* 65: RFC4893 */ "AS4", 0, /* 67: [Chen] */ "DYNAMIC_CAPABILITY", /* 68: [Appanna] */ "MULTISESSION", /* 69: RFC7911 */ "ADD-PATH", /* 70: RFC7313 */ "ENHANCED_ROUTE_REFRESH" }; #define bgp_capcode(x) \ num_or_str(bgp_capcode, sizeof(bgp_capcode)/sizeof(bgp_capcode[0]), (x)) static const char *bgp_roletype[] = { "Provider", "Route Server", "RS Client", "Customer", "Lateral Peer" }; #define bgp_roletype(x) \ num_or_str(bgp_roletype, \ sizeof(bgp_roletype)/sizeof(bgp_roletype[0]), (x)) #define BGP_NOTIFY_MAJOR_CEASE 6 static const char *bgpnotify_major[] = { NULL, "Message Header Error", "OPEN Message Error", "UPDATE Message Error", "Hold Timer Expired", "Finite State Machine Error", "Cease", "ROUTE_REFRESH Message Error", }; #define bgp_notify_major(x) \ num_or_str(bgpnotify_major, \ sizeof(bgpnotify_major)/sizeof(bgpnotify_major[0]), (x)) static const char *bgpnotify_minor_msg[] = { NULL, "Connection Not Synchronized", "Bad Message Length", "Bad Message Type", }; static const char *bgpnotify_minor_open[] = { NULL, "Unsupported Version Number", "Bad Peer AS", "Bad BGP Identifier", "Unsupported Optional Parameter", "Authentication Failure", "Unacceptable Hold Time", "Unsupported Capability", NULL, NULL, NULL, "Role Mismatch" }; static const char *bgpnotify_minor_update[] = { 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_holdtime[] = { NULL, }; /* RFC 6608 */ static const char *bgpnotify_minor_fsm[] = { "Unspecified Error", "In OpenSent State", "In OpenConfirm State", "In Established State", }; /* RFC 4486 */ #define BGP_NOTIFY_MINOR_CEASE_MAXPRFX 1 /* RFC 8203 */ #define BGP_NOTIFY_MINOR_CEASE_SHUT 2 #define BGP_NOTIFY_MINOR_CEASE_RESET 4 #define BGP_NOTIFY_MINOR_CEASE_ADMIN_SHUTDOWN_LEN 255 static const char *bgpnotify_minor_cease[] = { NULL, "Maximum Number of Prefixes Reached", "Administrative Shutdown", "Peer De-configured", "Administrative Reset", "Connection Rejected", "Other Configuration Change", "Connection Collision Resolution", "Out of Resources", }; /* RFC 7313 */ static const char *bgpnotify_minor_err[] = { NULL, "Invalid Message Length", }; static const char **bgpnotify_minor[] = { NULL, bgpnotify_minor_msg, bgpnotify_minor_open, bgpnotify_minor_update, bgpnotify_minor_holdtime, bgpnotify_minor_fsm, bgpnotify_minor_cease, bgpnotify_minor_err, }; static const int bgpnotify_minor_siz[] = { 0, sizeof(bgpnotify_minor_msg)/sizeof(bgpnotify_minor_msg[0]), sizeof(bgpnotify_minor_open)/sizeof(bgpnotify_minor_open[0]), sizeof(bgpnotify_minor_update)/sizeof(bgpnotify_minor_update[0]), sizeof(bgpnotify_minor_holdtime)/sizeof(bgpnotify_minor_holdtime[0]), sizeof(bgpnotify_minor_fsm)/sizeof(bgpnotify_minor_fsm[0]), sizeof(bgpnotify_minor_cease)/sizeof(bgpnotify_minor_cease[0]), sizeof(bgpnotify_minor_err)/sizeof(bgpnotify_minor_err[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", "EXTD_COMMUNITIES", "AS4_PATH", "AGGREGATOR4", NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, "LARGE_COMMUNITIES", NULL, NULL, "ONLY_TO_CUSTOMER" }; #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", "labeled Unicast", /* MPLS BGP RFC3107 */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 64-66: MPLS BGP RFC3107 */ "Tunnel", "VPLS", "MDT", 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 128-129: RFC4364 + RFC6513 */ "L3VPN Unicast", "L3VPN 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 *refreshtype[] = { "Request", "BoRR", "EoRR" }; #define refresh_subtype(x) \ num_or_str(refreshtype, sizeof(refreshtype)/sizeof(refreshtype[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 */ plen = pd[0]; if (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/%u", getname((u_char *)&addr), plen); if (n < 0 || n >= buflen) return -1; return 1 + (plen + 7) / 8; trunc: return -2; } 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 (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/%u", getname6((u_char *)&addr), plen); if (n < 0 || n >= buflen) return -1; return 1 + (plen + 7) / 8; trunc: return -2; } 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, asn_bytes; const u_char *p; char buf[HOST_NAME_MAX+1 + 100]; p = dat; tlen = len; asn_bytes = 0; 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_AS4_PATH: asn_bytes = 4; /* FALLTHROUGH */ case BGPTYPE_AS_PATH: /* * 2-byte speakers will receive AS4_PATH as well AS_PATH (2-byte). * 4-byte speakers will only receive AS_PATH but it will be 4-byte. * To identify which is the case, compare the length of the path * segment value in bytes, with the path segment length from the * message (counted in # of AS) */ if (len % 2) { printf(" invalid len"); break; } if (!len) { /* valid: local originated routes to IBGP peers */ printf(" empty"); break; } while (p < dat + len) { TCHECK2(p[0], 2); if (asn_bytes == 0) { if (p[1] == 0) { /* invalid: segment contains one or more AS */ printf(" malformed"); break; } asn_bytes = (len-2)/p[1]; } printf("%s", tok2str(bgp_as_path_segment_open_values, "?", p[0])); for (i = 0; i < p[1] * asn_bytes; i += asn_bytes) { TCHECK2(p[2 + i], asn_bytes); printf("%s", i == 0 ? "" : " "); if (asn_bytes == 2) printf("%u", EXTRACT_16BITS(&p[2 + i])); else printf("%u", EXTRACT_32BITS(&p[2 + i])); } printf("%s", tok2str(bgp_as_path_segment_close_values, "?", p[0])); p += 2 + p[1] * asn_bytes; } 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_AGGREGATOR4: case BGPTYPE_AGGREGATOR: /* * like AS_PATH/AS4_PATH, AGGREGATOR can contain * either 2-byte or 4-byte ASN, and AGGREGATOR4 * always contains 4-byte ASN. */ if (len != 6 && len != 8) { printf(" invalid len"); break; } TCHECK2(p[0], len); printf(" AS #"); if (len == 6) printf("%u", EXTRACT_16BITS(p)); else printf("%u", EXTRACT_32BITS(p)); printf(", origin %s", getname(p+len-4)); break; case BGPTYPE_COMMUNITIES: if (len % 4) { printf(" invalid len"); break; } while (tlen>0) { u_int32_t comm; TCHECK2(p[0], 4); comm = EXTRACT_32BITS(p); 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; } tlen -= 4; p += 4; } break; case BGPTYPE_LARGE_COMMUNITIES: if (len == 0 || len % 12) { printf(" invalid len"); break; } while (tlen>0) { TCHECK2(p[0], 12); printf(" %u:%u:%u", EXTRACT_32BITS(p), EXTRACT_32BITS(p + 4), EXTRACT_32BITS(p + 8)); tlen -= 12; p += 12; } break; case BGPTYPE_ONLY_TO_CUSTOMER: if (len != 4) { printf(" invalid len"); break; } TCHECK2(p[0], 4); printf(" AS%u", EXTRACT_32BITS(p)); break; case BGPTYPE_ORIGINATOR_ID: if (len != 4) { printf(" invalid len"); break; } TCHECK2(p[0], 4); printf("%s",getname(p)); break; case BGPTYPE_CLUSTER_LIST: if (len % 4) { printf(" invalid len"); break; } while (tlen>0) { TCHECK2(p[0], 4); printf(" %s%s", getname(p), (tlen>4) ? ", " : ""); tlen -=4; p +=4; } 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 %u,", af_name(af), safi); else { printf(" %s %s,", af_name(af), bgp_attr_nlri_safi(safi)); } p += 3; if (af != AFNUM_INET && af != AFNUM_INET6) 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; case AFNUM_INET6: TCHECK2(p[1+i], sizeof(struct in6_addr)); printf(" %s", getname6(p + 1 + i)); i += sizeof(struct in6_addr); break; 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; case AFNUM_INET6: advance = decode_prefix6(p, buf, sizeof(buf)); break; 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 %u,", af_name(af), safi); 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; case AFNUM_INET6: advance = decode_prefix6(p, buf, sizeof(buf)); break; 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_capa_print(const u_char *opt, int length) { int i,cap_type,cap_len,tcap_len,cap_offset; i = 0; while (i < length) { TCHECK2(opt[i], 2); cap_type=opt[i]; cap_len=opt[i+1]; printf("%sCAP %s", i == 0 ? "(" : " ", /* ) */ bgp_capcode(cap_type)); /* can we print the capability? */ TCHECK2(opt[i+2],cap_len); i += 2; switch(cap_type) { case BGP_CAPCODE_MP: if (cap_len != 4) { printf(" BAD ENCODING"); break; } printf(" [%s %s]", af_name(EXTRACT_16BITS(opt+i)), bgp_attr_nlri_safi(opt[i+3])); break; case BGP_CAPCODE_REFRESH: if (cap_len != 0) { printf(" BAD ENCODING"); break; } break; case BGP_CAPCODE_BGPROLE: if (cap_len != 1) { printf(" BAD ENCODING"); break; } printf(" [%s]", bgp_roletype(opt[i])); break; case BGP_CAPCODE_RESTART: if (cap_len < 2 || (cap_len - 2) % 4) { printf(" BAD ENCODING"); break; } printf(" [%s], Time %us", ((opt[i])&0x80) ? "R" : "none", EXTRACT_16BITS(opt+i)&0xfff); tcap_len=cap_len - 2; cap_offset=2; while(tcap_len>=4) { printf(" (%s %s)%s", af_name(EXTRACT_16BITS(opt+i+cap_offset)), bgp_attr_nlri_safi(opt[i+cap_offset+2]), ((opt[i+cap_offset+3])&0x80) ? " forwarding state preserved" : "" ); tcap_len-=4; cap_offset+=4; } break; case BGP_CAPCODE_AS4: if (cap_len != 4) { printf(" BAD ENCODING"); break; } printf(" #"); printf("%u", EXTRACT_32BITS(opt+i)); break; default: printf(" len %d", cap_len); break; } i += cap_len; if (i + cap_len < length) printf(","); } /* ( */ printf(")"); return; trunc: printf("[|BGP]"); } 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); /* sanity checking */ if ((length < bgpo.bgpo_optlen+BGP_OPEN_SIZE) || (!bgpo.bgpo_optlen)) return; /* 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; } if (i == 0) printf(" ("); /* ) */ else printf(" "); switch(bgpopt.bgpopt_type) { case BGP_OPT_CAP: bgp_open_capa_print(opt + i + BGP_OPT_SIZE, bgpopt.bgpopt_len); break; default: printf(" (option %s, len=%u)", bgp_opttype(bgpopt.bgpopt_type), bgpopt.bgpopt_len); break; } i += BGP_OPT_SIZE + bgpopt.bgpopt_len; } /* ( */ printf(")"); 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 do not try to decode it. */ printf(" (Withdrawn routes: %d bytes)", len); } p += 2 + len; TCHECK2(p[0], 2); len = EXTRACT_16BITS(p); if (len == 0 && length == BGP_UPDATE_MINSIZE) { printf(" End-of-Rib Marker (empty NLRI)"); return; } 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[HOST_NAME_MAX+1 + 100]; i = decode_prefix4(p, buf, sizeof(buf)); if (i == -1) { printf(" (illegal prefix length)"); break; } else if (i == -2) goto trunc; 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; u_int16_t af; u_int8_t safi; const u_char *p; size_t shutdown_comm_length; char shutstring[BGP_NOTIFY_MINOR_CEASE_ADMIN_SHUTDOWN_LEN + 1]; TCHECK2(dat[0], BGP_NOTIFICATION_SIZE); memcpy(&bgpn, dat, BGP_NOTIFICATION_SIZE); /* sanity checking */ if (length < BGP_NOTIFICATION_SIZE) return; printf(": error %s,", bgp_notify_major(bgpn.bgpn_major)); printf(" subcode %s", bgp_notify_minor(bgpn.bgpn_major, bgpn.bgpn_minor)); if (bgpn.bgpn_major == BGP_NOTIFY_MAJOR_CEASE) { /* * RFC 4486: optional maxprefix subtype of 7 bytes * may contain AFI, SAFI and MAXPREFIXES */ if(bgpn.bgpn_minor == BGP_NOTIFY_MINOR_CEASE_MAXPRFX && length >= BGP_NOTIFICATION_SIZE + 7) { p = dat + BGP_NOTIFICATION_SIZE; TCHECK2(*p, 7); af = EXTRACT_16BITS(p); safi = p[2]; printf(" %s %s,", af_name(af), bgp_attr_nlri_safi(safi)); printf(" Max Prefixes: %u", EXTRACT_32BITS(p+3)); } /* * RFC 8203 describes a method to send a message intended * for human consumption regarding the Administrative * Shutdown or Reset event. This is called the "Shutdown * Communication". The communication is UTF-8 encoded * and may be no longer than 128 bytes. */ if ((bgpn.bgpn_minor == BGP_NOTIFY_MINOR_CEASE_SHUT || bgpn.bgpn_minor == BGP_NOTIFY_MINOR_CEASE_RESET) && (length >= BGP_NOTIFICATION_SIZE + 1)) { p = dat + BGP_NOTIFICATION_SIZE; TCHECK2(*p, 1); shutdown_comm_length = *p; /* sanity checking */ if (shutdown_comm_length == 0) return; if (shutdown_comm_length > BGP_NOTIFY_MINOR_CEASE_ADMIN_SHUTDOWN_LEN) goto trunc; if (length < (shutdown_comm_length + 1 + BGP_NOTIFICATION_SIZE)) goto trunc; TCHECK2(*(p+1), shutdown_comm_length); /* a proper shutdown communication */ printf(", Shutdown Communication [len %zu]: \"", shutdown_comm_length); memset(shutstring, 0, sizeof(shutstring)); memcpy(shutstring, p+1, shutdown_comm_length); safeputs(shutstring); printf("\""); } } return; trunc: printf("[|BGP]"); } static void bgp_route_refresh_print(const u_char *dat, int length) { const struct bgp_route_refresh *bgp_route_refresh_header; TCHECK2(dat[0], BGP_ROUTE_REFRESH_SIZE); /* sanity checking */ if (lengthsubtype), af_name(EXTRACT_16BITS(&bgp_route_refresh_header->afi)), bgp_attr_nlri_safi(bgp_route_refresh_header->safi)); 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; case BGP_KEEPALIVE: break; case BGP_ROUTE_REFRESH: bgp_route_refresh_print(dat, length); default: TCHECK2(*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 (hlen < BGP_SIZE) { printf("\n[|BGP Bogus header length %u < %u]", hlen, BGP_SIZE); break; } 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]"); }