/* * Copyright (c) 2000 Lennert Buytenhek * * This software may be distributed either under the terms of the * BSD-style license that accompanies tcpdump or the GNU General * Public License * * Format and print IEEE 802.1d spanning tree protocol packets. * Contributed by Lennert Buytenhek */ #ifndef lint static const char rcsid[] _U_ = "@(#) $Header: /tcpdump/master/tcpdump/print-stp.c,v 1.13.2.7 2007/03/18 17:12:36 hannes Exp $"; #endif #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include #include #include #include "interface.h" #include "addrtoname.h" #include "extract.h" #define RSTP_EXTRACT_PORT_ROLE(x) (((x)&0x0C)>>2) /* STP timers are expressed in multiples of 1/256th second */ #define STP_TIME_BASE 256 #define STP_BPDU_MSTP_MIN_LEN 102 struct stp_bpdu_ { u_int8_t protocol_id[2]; u_int8_t protocol_version; u_int8_t bpdu_type; u_int8_t flags; u_int8_t root_id[8]; u_int8_t root_path_cost[4]; u_int8_t bridge_id[8]; u_int8_t port_id[2]; u_int8_t message_age[2]; u_int8_t max_age[2]; u_int8_t hello_time[2]; u_int8_t forward_delay[2]; u_int8_t v1_length; }; #define STP_PROTO_REGULAR 0x00 #define STP_PROTO_RAPID 0x02 #define STP_PROTO_MSTP 0x03 struct tok stp_proto_values[] = { { STP_PROTO_REGULAR, "802.1d" }, { STP_PROTO_RAPID, "802.1w" }, { STP_PROTO_MSTP, "802.1s" }, { 0, NULL} }; #define STP_BPDU_TYPE_CONFIG 0x00 #define STP_BPDU_TYPE_RSTP 0x02 #define STP_BPDU_TYPE_TOPO_CHANGE 0x80 struct tok stp_bpdu_flag_values[] = { { 0x01, "Topology change" }, { 0x02, "Proposal" }, { 0x10, "Learn" }, { 0x20, "Forward" }, { 0x40, "Agreement" }, { 0x80, "Topology change ACK" }, { 0, NULL} }; struct tok stp_bpdu_type_values[] = { { STP_BPDU_TYPE_CONFIG, "Config" }, { STP_BPDU_TYPE_RSTP, "Rapid STP" }, { STP_BPDU_TYPE_TOPO_CHANGE, "Topology Change" }, { 0, NULL} }; struct tok rstp_obj_port_role_values[] = { { 0x00, "Unknown" }, { 0x01, "Alternate" }, { 0x02, "Root" }, { 0x03, "Designated" }, { 0, NULL} }; static char * stp_print_bridge_id(const u_char *p) { static char bridge_id_str[sizeof("pppp.aa:bb:cc:dd:ee:ff")]; snprintf(bridge_id_str, sizeof(bridge_id_str), "%.2x%.2x.%.2x:%.2x:%.2x:%.2x:%.2x:%.2x", p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]); return bridge_id_str; } static void stp_print_config_bpdu(const struct stp_bpdu_ *stp_bpdu, u_int length) { printf(", Flags [%s]", bittok2str(stp_bpdu_flag_values, "none", stp_bpdu->flags)); printf(", bridge-id %s.%04x, length %u", stp_print_bridge_id((const u_char *)&stp_bpdu->bridge_id), EXTRACT_16BITS(&stp_bpdu->port_id), length); /* in non-verbose mode just print the bridge-id */ if (!vflag) { return; } printf("\n\tmessage-age %.2fs, max-age %.2fs" ", hello-time %.2fs, forwarding-delay %.2fs", (float)EXTRACT_16BITS(&stp_bpdu->message_age) / STP_TIME_BASE, (float)EXTRACT_16BITS(&stp_bpdu->max_age) / STP_TIME_BASE, (float)EXTRACT_16BITS(&stp_bpdu->hello_time) / STP_TIME_BASE, (float)EXTRACT_16BITS(&stp_bpdu->forward_delay) / STP_TIME_BASE); printf("\n\troot-id %s, root-pathcost %u", stp_print_bridge_id((const u_char *)&stp_bpdu->root_id), EXTRACT_32BITS(&stp_bpdu->root_path_cost)); /* Port role is only valid for 802.1w */ if (stp_bpdu->protocol_version == STP_PROTO_RAPID) { printf(", port-role %s", tok2str(rstp_obj_port_role_values, "Unknown", RSTP_EXTRACT_PORT_ROLE(stp_bpdu->flags))); } } /* * MSTP packet format * Ref. IEEE 802.1Q 2003 Ed. Section 14 * * MSTP BPDU * * 2 - bytes Protocol Id * 1 - byte Protocol Ver. * 1 - byte BPDU tye * 1 - byte Flags * 8 - bytes CIST Root Identifier * 4 - bytes CIST External Path Cost * 8 - bytes CIST Regional Root Identifier * 2 - bytes CIST Port Identifier * 2 - bytes Message Age * 2 - bytes Max age * 2 - bytes Hello Time * 2 - bytes Forward delay * 1 - byte Version 1 length. Must be 0 * 2 - bytes Version 3 length * 1 - byte Config Identifier * 32 - bytes Config Name * 2 - bytes Revision level * 16 - bytes Config Digest [MD5] * 4 - bytes CIST Internal Root Path Cost * 8 - bytes CIST Bridge Identifier * 1 - byte CIST Remaining Hops * 16 - bytes MSTI information [Max 64 MSTI, each 16 bytes] * * MSTI Payload * * 1 - byte MSTI flag * 8 - bytes MSTI Regional Root Identifier * 4 - bytes MSTI Regional Path Cost * 1 - byte MSTI Bridge Priority * 1 - byte MSTI Port Priority * 1 - byte MSTI Remaining Hops */ #define MST_BPDU_MSTI_LENGTH 16 #define MST_BPDU_CONFIG_INFO_LENGTH 64 /* Offsets of fields from the begginning for the packet */ #define MST_BPDU_VER3_LEN_OFFSET 36 #define MST_BPDU_CONFIG_NAME_OFFSET 39 #define MST_BPDU_CONFIG_DIGEST_OFFSET 73 #define MST_BPDU_CIST_INT_PATH_COST_OFFSET 89 #define MST_BPDU_CIST_BRIDGE_ID_OFFSET 93 #define MST_BPDU_CIST_REMAIN_HOPS_OFFSET 101 #define MST_BPDU_MSTI_OFFSET 102 /* Offsets within an MSTI */ #define MST_BPDU_MSTI_ROOT_PRIO_OFFSET 1 #define MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET 9 #define MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET 13 #define MST_BPDU_MSTI_PORT_PRIO_OFFSET 14 #define MST_BPDU_MSTI_REMAIN_HOPS_OFFSET 15 static void stp_print_mstp_bpdu(const struct stp_bpdu_ *stp_bpdu, u_int length) { const u_char *ptr; u_int16_t v3len; u_int16_t len; u_int16_t msti; u_int16_t offset; ptr = (const u_char *)stp_bpdu; printf(", CIST Flags [%s]", bittok2str(stp_bpdu_flag_values, "none", stp_bpdu->flags)); /* * in non-verbose mode just print the flags. We dont read that much * of the packet (DEFAULT_SNAPLEN) to print out cist bridge-id */ if (!vflag) { return; } printf(", CIST bridge-id %s.%04x, length %u", stp_print_bridge_id(ptr + MST_BPDU_CIST_BRIDGE_ID_OFFSET), EXTRACT_16BITS(&stp_bpdu->port_id), length); printf("\n\tmessage-age %.2fs, max-age %.2fs" ", hello-time %.2fs, forwarding-delay %.2fs", (float)EXTRACT_16BITS(&stp_bpdu->message_age) / STP_TIME_BASE, (float)EXTRACT_16BITS(&stp_bpdu->max_age) / STP_TIME_BASE, (float)EXTRACT_16BITS(&stp_bpdu->hello_time) / STP_TIME_BASE, (float)EXTRACT_16BITS(&stp_bpdu->forward_delay) / STP_TIME_BASE); printf("\n\tCIST root-id %s, ext-pathcost %u int-pathcost %u", stp_print_bridge_id((const u_char *)&stp_bpdu->root_id), EXTRACT_32BITS(&stp_bpdu->root_path_cost), EXTRACT_32BITS(ptr + MST_BPDU_CIST_INT_PATH_COST_OFFSET)); printf(", port-role %s", tok2str(rstp_obj_port_role_values, "Unknown", RSTP_EXTRACT_PORT_ROLE(stp_bpdu->flags))); printf("\n\tCIST regional-root-id %s", stp_print_bridge_id((const u_char *)&stp_bpdu->bridge_id)); printf("\n\tMSTP Configuration Name %s, revision %u, digest %08x%08x%08x%08x", ptr + MST_BPDU_CONFIG_NAME_OFFSET, EXTRACT_16BITS(ptr + MST_BPDU_CONFIG_NAME_OFFSET + 32), EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET), EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 4), EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 8), EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 12)); printf("\n\tCIST remaining-hops %d", ptr[MST_BPDU_CIST_REMAIN_HOPS_OFFSET]); /* Dump all MSTI's */ v3len = EXTRACT_16BITS(ptr + MST_BPDU_VER3_LEN_OFFSET); if (v3len > MST_BPDU_CONFIG_INFO_LENGTH) { len = v3len - MST_BPDU_CONFIG_INFO_LENGTH; offset = MST_BPDU_MSTI_OFFSET; while (len >= MST_BPDU_MSTI_LENGTH) { msti = EXTRACT_16BITS(ptr + offset + MST_BPDU_MSTI_ROOT_PRIO_OFFSET); msti = msti & 0x0FFF; printf("\n\tMSTI %d, Flags [%s], port-role %s", msti, bittok2str(stp_bpdu_flag_values, "none", ptr[offset]), tok2str(rstp_obj_port_role_values, "Unknown", RSTP_EXTRACT_PORT_ROLE(ptr[offset]))); printf("\n\t\tMSTI regional-root-id %s, pathcost %u", stp_print_bridge_id(ptr + offset + MST_BPDU_MSTI_ROOT_PRIO_OFFSET), EXTRACT_32BITS(ptr + offset + MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET)); printf("\n\t\tMSTI bridge-prio %d, port-prio %d, hops %d", ptr[offset + MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET] >> 4, ptr[offset + MST_BPDU_MSTI_PORT_PRIO_OFFSET] >> 4, ptr[offset + MST_BPDU_MSTI_REMAIN_HOPS_OFFSET]); len -= MST_BPDU_MSTI_LENGTH; offset += MST_BPDU_MSTI_LENGTH; } } } /* * Print 802.1d / 802.1w / 802.1q (mstp) packets. */ void stp_print(const u_char *p, u_int length) { const struct stp_bpdu_ *stp_bpdu; u_int16_t mstp_len; stp_bpdu = (struct stp_bpdu_*)p; /* Minimum STP Frame size. */ if (length < 4) goto trunc; if (EXTRACT_16BITS(&stp_bpdu->protocol_id)) { printf("unknown STP version, length %u", length); return; } printf("STP %s", tok2str(stp_proto_values, "Unknown STP protocol (0x%02x)", stp_bpdu->protocol_version)); switch (stp_bpdu->protocol_version) { case STP_PROTO_REGULAR: case STP_PROTO_RAPID: case STP_PROTO_MSTP: break; default: return; } printf(", %s", tok2str(stp_bpdu_type_values, "Unknown BPDU Type (0x%02x)", stp_bpdu->bpdu_type)); switch (stp_bpdu->bpdu_type) { case STP_BPDU_TYPE_CONFIG: if (length < sizeof(struct stp_bpdu_) - 1) { goto trunc; } stp_print_config_bpdu(stp_bpdu, length); break; case STP_BPDU_TYPE_RSTP: if (stp_bpdu->protocol_version == STP_PROTO_RAPID) { if (length < sizeof(struct stp_bpdu_)) { goto trunc; } stp_print_config_bpdu(stp_bpdu, length); } else if (stp_bpdu->protocol_version == STP_PROTO_MSTP) { if (length < STP_BPDU_MSTP_MIN_LEN) { goto trunc; } if (stp_bpdu->v1_length != 0) { /* FIX ME: Emit a message here ? */ goto trunc; } /* Validate v3 length */ mstp_len = EXTRACT_16BITS(p + MST_BPDU_VER3_LEN_OFFSET); mstp_len += 2; /* length encoding itself is 2 bytes */ if (length < (sizeof(struct stp_bpdu_) + mstp_len)) { goto trunc; } stp_print_mstp_bpdu(stp_bpdu, length); } break; case STP_BPDU_TYPE_TOPO_CHANGE: /* always empty message - just break out */ break; default: break; } return; trunc: printf("[|stp %d]", length); } /* * Local Variables: * c-style: whitesmith * c-basic-offset: 4 * End: */