| /* |
| * 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 |
| * |
| * Contributed by Lennert Buytenhek <buytenh@gnu.org> |
| */ |
| |
| /* \summary: IEEE 802.1d Spanning Tree Protocol (STP) printer */ |
| |
| #ifdef HAVE_CONFIG_H |
| #include <config.h> |
| #endif |
| |
| #include "netdissect-stdinc.h" |
| |
| #include <stdio.h> |
| |
| #include "netdissect.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_ { |
| nd_uint16_t protocol_id; |
| nd_uint8_t protocol_version; |
| nd_uint8_t bpdu_type; |
| nd_uint8_t flags; |
| nd_byte root_id[8]; |
| nd_uint32_t root_path_cost; |
| nd_byte bridge_id[8]; |
| nd_uint16_t port_id; |
| nd_uint16_t message_age; |
| nd_uint16_t max_age; |
| nd_uint16_t hello_time; |
| nd_uint16_t forward_delay; |
| nd_uint8_t v1_length; |
| }; |
| |
| #define STP_PROTO_REGULAR 0x00 |
| #define STP_PROTO_RAPID 0x02 |
| #define STP_PROTO_MSTP 0x03 |
| #define STP_PROTO_SPB 0x04 |
| |
| static const struct tok stp_proto_values[] = { |
| { STP_PROTO_REGULAR, "802.1d" }, |
| { STP_PROTO_RAPID, "802.1w" }, |
| { STP_PROTO_MSTP, "802.1s" }, |
| { STP_PROTO_SPB, "802.1aq" }, |
| { 0, NULL} |
| }; |
| |
| #define STP_BPDU_TYPE_CONFIG 0x00 |
| #define STP_BPDU_TYPE_RSTP 0x02 |
| #define STP_BPDU_TYPE_TOPO_CHANGE 0x80 |
| |
| static const struct tok stp_bpdu_flag_values[] = { |
| { 0x01, "Topology change" }, |
| { 0x02, "Proposal" }, |
| { 0x10, "Learn" }, |
| { 0x20, "Forward" }, |
| { 0x40, "Agreement" }, |
| { 0x80, "Topology change ACK" }, |
| { 0, NULL} |
| }; |
| |
| static const 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} |
| }; |
| |
| static const struct tok rstp_obj_port_role_values[] = { |
| { 0x00, "Unknown" }, |
| { 0x01, "Alternate" }, |
| { 0x02, "Root" }, |
| { 0x03, "Designated" }, |
| { 0, NULL} |
| }; |
| |
| static char * |
| stp_print_bridge_id(netdissect_options *ndo, 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", |
| GET_U_1(p), GET_U_1(p + 1), GET_U_1(p + 2), |
| GET_U_1(p + 3), GET_U_1(p + 4), GET_U_1(p + 5), |
| GET_U_1(p + 6), GET_U_1(p + 7)); |
| |
| return bridge_id_str; |
| } |
| |
| static void |
| stp_print_config_bpdu(netdissect_options *ndo, const struct stp_bpdu_ *stp_bpdu, |
| u_int length) |
| { |
| uint8_t bpdu_flags; |
| |
| bpdu_flags = GET_U_1(stp_bpdu->flags); |
| ND_PRINT(", Flags [%s]", |
| bittok2str(stp_bpdu_flag_values, "none", bpdu_flags)); |
| |
| ND_PRINT(", bridge-id %s.%04x, length %u", |
| stp_print_bridge_id(ndo, stp_bpdu->bridge_id), |
| GET_BE_U_2(stp_bpdu->port_id), length); |
| |
| /* in non-verbose mode just print the bridge-id */ |
| if (!ndo->ndo_vflag) { |
| return; |
| } |
| |
| ND_PRINT("\n\tmessage-age %.2fs, max-age %.2fs" |
| ", hello-time %.2fs, forwarding-delay %.2fs", |
| (float) GET_BE_U_2(stp_bpdu->message_age) / STP_TIME_BASE, |
| (float) GET_BE_U_2(stp_bpdu->max_age) / STP_TIME_BASE, |
| (float) GET_BE_U_2(stp_bpdu->hello_time) / STP_TIME_BASE, |
| (float) GET_BE_U_2(stp_bpdu->forward_delay) / STP_TIME_BASE); |
| |
| ND_PRINT("\n\troot-id %s, root-pathcost %u", |
| stp_print_bridge_id(ndo, stp_bpdu->root_id), |
| GET_BE_U_4(stp_bpdu->root_path_cost)); |
| |
| /* Port role is only valid for 802.1w */ |
| if (GET_U_1(stp_bpdu->protocol_version) == STP_PROTO_RAPID) { |
| ND_PRINT(", port-role %s", |
| tok2str(rstp_obj_port_role_values, "Unknown", |
| RSTP_EXTRACT_PORT_ROLE(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] |
| * |
| * |
| * SPB BPDU |
| * Ref. IEEE 802.1aq. Section 14 |
| * |
| * 2 - bytes Version 4 length |
| * 1 - byte Aux Config Identifier |
| * 32 - bytes Aux Config Name |
| * 2 - bytes Aux Revision level |
| * 16 - bytes Aux Config Digest [MD5] |
| * 1 - byte (1 - 2) Agreement Number |
| * (3 - 4) Discarded Agreement Number |
| * (5) Agreement Valid Flag |
| * (6) Restricted Role Flag |
| * (7 - 8) Unused sent zero |
| * 1 - byte Unused |
| * 1 - byte (1 - 4) Agreement Digest Format Identifier |
| * (5 - 8) Agreement Digest Format Capabilities |
| * 1 - byte (1 - 4) Agreement Digest Convention Identifier |
| * (5 - 8) Agreement Digest Convention Capabilities |
| * 2 - bytes Agreement Digest Edge Count |
| * 8 - byte Reserved Set |
| * 20 - bytes Computed Topology Digest |
| * |
| * |
| * 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 beginning 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 |
| |
| #define SPB_BPDU_MIN_LEN 87 |
| #define SPB_BPDU_CONFIG_NAME_OFFSET 3 |
| #define SPB_BPDU_CONFIG_REV_OFFSET SPB_BPDU_CONFIG_NAME_OFFSET + 32 |
| #define SPB_BPDU_CONFIG_DIGEST_OFFSET SPB_BPDU_CONFIG_REV_OFFSET + 2 |
| #define SPB_BPDU_AGREEMENT_OFFSET SPB_BPDU_CONFIG_DIGEST_OFFSET + 16 |
| #define SPB_BPDU_AGREEMENT_UNUSED_OFFSET SPB_BPDU_AGREEMENT_OFFSET + 1 |
| #define SPB_BPDU_AGREEMENT_FORMAT_OFFSET SPB_BPDU_AGREEMENT_UNUSED_OFFSET + 1 |
| #define SPB_BPDU_AGREEMENT_CON_OFFSET SPB_BPDU_AGREEMENT_FORMAT_OFFSET + 1 |
| #define SPB_BPDU_AGREEMENT_EDGE_OFFSET SPB_BPDU_AGREEMENT_CON_OFFSET + 1 |
| #define SPB_BPDU_AGREEMENT_RES1_OFFSET SPB_BPDU_AGREEMENT_EDGE_OFFSET + 2 |
| #define SPB_BPDU_AGREEMENT_RES2_OFFSET SPB_BPDU_AGREEMENT_RES1_OFFSET + 4 |
| #define SPB_BPDU_AGREEMENT_DIGEST_OFFSET SPB_BPDU_AGREEMENT_RES2_OFFSET + 4 |
| |
| static void |
| stp_print_mstp_bpdu(netdissect_options *ndo, const struct stp_bpdu_ *stp_bpdu, |
| u_int length) |
| { |
| const u_char *ptr; |
| uint8_t bpdu_flags; |
| uint16_t v3len; |
| uint16_t len; |
| uint16_t msti; |
| u_int offset; |
| |
| ptr = (const u_char *)stp_bpdu; |
| bpdu_flags = GET_U_1(stp_bpdu->flags); |
| ND_PRINT(", CIST Flags [%s], length %u", |
| bittok2str(stp_bpdu_flag_values, "none", bpdu_flags), length); |
| |
| /* |
| * in non-verbose mode just print the flags. |
| */ |
| if (!ndo->ndo_vflag) { |
| return; |
| } |
| |
| ND_PRINT("\n\tport-role %s, ", |
| tok2str(rstp_obj_port_role_values, "Unknown", |
| RSTP_EXTRACT_PORT_ROLE(bpdu_flags))); |
| |
| ND_PRINT("CIST root-id %s, CIST ext-pathcost %u", |
| stp_print_bridge_id(ndo, stp_bpdu->root_id), |
| GET_BE_U_4(stp_bpdu->root_path_cost)); |
| |
| ND_PRINT("\n\tCIST regional-root-id %s, ", |
| stp_print_bridge_id(ndo, stp_bpdu->bridge_id)); |
| |
| ND_PRINT("CIST port-id %04x,", GET_BE_U_2(stp_bpdu->port_id)); |
| |
| ND_PRINT("\n\tmessage-age %.2fs, max-age %.2fs" |
| ", hello-time %.2fs, forwarding-delay %.2fs", |
| (float) GET_BE_U_2(stp_bpdu->message_age) / STP_TIME_BASE, |
| (float) GET_BE_U_2(stp_bpdu->max_age) / STP_TIME_BASE, |
| (float) GET_BE_U_2(stp_bpdu->hello_time) / STP_TIME_BASE, |
| (float) GET_BE_U_2(stp_bpdu->forward_delay) / STP_TIME_BASE); |
| |
| ND_PRINT("\n\tv3len %u, ", GET_BE_U_2(ptr + MST_BPDU_VER3_LEN_OFFSET)); |
| ND_PRINT("MCID Name "); |
| nd_printjnp(ndo, ptr + MST_BPDU_CONFIG_NAME_OFFSET, 32); |
| ND_PRINT(", rev %u," |
| "\n\t\tdigest %08x%08x%08x%08x, ", |
| GET_BE_U_2(ptr + MST_BPDU_CONFIG_NAME_OFFSET + 32), |
| GET_BE_U_4(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET), |
| GET_BE_U_4(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 4), |
| GET_BE_U_4(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 8), |
| GET_BE_U_4(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 12)); |
| |
| ND_PRINT("CIST int-root-pathcost %u,", |
| GET_BE_U_4(ptr + MST_BPDU_CIST_INT_PATH_COST_OFFSET)); |
| |
| ND_PRINT("\n\tCIST bridge-id %s, ", |
| stp_print_bridge_id(ndo, ptr + MST_BPDU_CIST_BRIDGE_ID_OFFSET)); |
| |
| ND_PRINT("CIST remaining-hops %u", |
| GET_U_1(ptr + MST_BPDU_CIST_REMAIN_HOPS_OFFSET)); |
| |
| /* Dump all MSTI's */ |
| v3len = GET_BE_U_2(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 = GET_BE_U_2(ptr + offset + MST_BPDU_MSTI_ROOT_PRIO_OFFSET); |
| msti = msti & 0x0FFF; |
| |
| ND_PRINT("\n\tMSTI %u, Flags [%s], port-role %s", |
| msti, |
| bittok2str(stp_bpdu_flag_values, "none", GET_U_1(ptr + offset)), |
| tok2str(rstp_obj_port_role_values, "Unknown", |
| RSTP_EXTRACT_PORT_ROLE(GET_U_1(ptr + offset)))); |
| ND_PRINT("\n\t\tMSTI regional-root-id %s, pathcost %u", |
| stp_print_bridge_id(ndo, ptr + offset + |
| MST_BPDU_MSTI_ROOT_PRIO_OFFSET), |
| GET_BE_U_4(ptr + offset + MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET)); |
| ND_PRINT("\n\t\tMSTI bridge-prio %u, port-prio %u, hops %u", |
| GET_U_1(ptr + offset + MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET) >> 4, |
| GET_U_1(ptr + offset + MST_BPDU_MSTI_PORT_PRIO_OFFSET) >> 4, |
| GET_U_1(ptr + offset + MST_BPDU_MSTI_REMAIN_HOPS_OFFSET)); |
| |
| len -= MST_BPDU_MSTI_LENGTH; |
| offset += MST_BPDU_MSTI_LENGTH; |
| } |
| } |
| } |
| |
| static void |
| stp_print_spb_bpdu(netdissect_options *ndo, const struct stp_bpdu_ *stp_bpdu, |
| u_int offset) |
| { |
| const u_char *ptr; |
| |
| /* |
| * in non-verbose mode don't print anything. |
| */ |
| if (!ndo->ndo_vflag) { |
| return; |
| } |
| |
| ptr = (const u_char *)stp_bpdu; |
| |
| ND_PRINT("\n\tv4len %u, ", GET_BE_U_2(ptr + offset)); |
| ND_PRINT("AUXMCID Name "); |
| nd_printjnp(ndo, ptr + offset + SPB_BPDU_CONFIG_NAME_OFFSET, 32); |
| ND_PRINT(", Rev %u,\n\t\tdigest %08x%08x%08x%08x", |
| GET_BE_U_2(ptr + offset + SPB_BPDU_CONFIG_REV_OFFSET), |
| GET_BE_U_4(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET), |
| GET_BE_U_4(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 4), |
| GET_BE_U_4(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 8), |
| GET_BE_U_4(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 12)); |
| |
| ND_PRINT("\n\tAgreement num %u, Discarded Agreement num %u, Agreement valid-" |
| "flag %u,\n\tRestricted role-flag: %u, Format id %u cap %u, " |
| "Convention id %u cap %u,\n\tEdge count %u, " |
| "Agreement digest %08x%08x%08x%08x%08x", |
| GET_U_1(ptr + offset + SPB_BPDU_AGREEMENT_OFFSET)>>6, |
| GET_U_1(ptr + offset + SPB_BPDU_AGREEMENT_OFFSET)>>4 & 0x3, |
| GET_U_1(ptr + offset + SPB_BPDU_AGREEMENT_OFFSET)>>3 & 0x1, |
| GET_U_1(ptr + offset + SPB_BPDU_AGREEMENT_OFFSET)>>2 & 0x1, |
| GET_U_1(ptr + offset + SPB_BPDU_AGREEMENT_FORMAT_OFFSET)>>4, |
| GET_U_1(ptr + offset + SPB_BPDU_AGREEMENT_FORMAT_OFFSET)&0x00ff, |
| GET_U_1(ptr + offset + SPB_BPDU_AGREEMENT_CON_OFFSET)>>4, |
| GET_U_1(ptr + offset + SPB_BPDU_AGREEMENT_CON_OFFSET)&0x00ff, |
| GET_BE_U_2(ptr + offset + SPB_BPDU_AGREEMENT_EDGE_OFFSET), |
| GET_BE_U_4(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET), |
| GET_BE_U_4(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET + 4), |
| GET_BE_U_4(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET + 8), |
| GET_BE_U_4(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET + 12), |
| GET_BE_U_4(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET + 16)); |
| } |
| |
| /* |
| * Print 802.1d / 802.1w / 802.1q (mstp) / 802.1aq (spb) packets. |
| */ |
| void |
| stp_print(netdissect_options *ndo, const u_char *p, u_int length) |
| { |
| const struct stp_bpdu_ *stp_bpdu; |
| u_int protocol_version; |
| u_int bpdu_type; |
| u_int mstp_len; |
| u_int spb_len; |
| |
| ndo->ndo_protocol = "stp"; |
| stp_bpdu = (const struct stp_bpdu_*)p; |
| |
| /* Minimum STP Frame size. */ |
| if (length < 4) |
| goto invalid; |
| |
| if (GET_BE_U_2(stp_bpdu->protocol_id)) { |
| ND_PRINT("unknown STP version, length %u", length); |
| return; |
| } |
| |
| protocol_version = GET_U_1(stp_bpdu->protocol_version); |
| ND_PRINT("STP %s", tok2str(stp_proto_values, "Unknown STP protocol (0x%02x)", |
| protocol_version)); |
| |
| switch (protocol_version) { |
| case STP_PROTO_REGULAR: |
| case STP_PROTO_RAPID: |
| case STP_PROTO_MSTP: |
| case STP_PROTO_SPB: |
| break; |
| default: |
| return; |
| } |
| |
| bpdu_type = GET_U_1(stp_bpdu->bpdu_type); |
| ND_PRINT(", %s", tok2str(stp_bpdu_type_values, "Unknown BPDU Type (0x%02x)", |
| bpdu_type)); |
| |
| switch (bpdu_type) { |
| case STP_BPDU_TYPE_CONFIG: |
| if (length < sizeof(struct stp_bpdu_) - 1) { |
| goto invalid; |
| } |
| stp_print_config_bpdu(ndo, stp_bpdu, length); |
| break; |
| |
| case STP_BPDU_TYPE_RSTP: |
| if (protocol_version == STP_PROTO_RAPID) { |
| if (length < sizeof(struct stp_bpdu_)) { |
| goto invalid; |
| } |
| stp_print_config_bpdu(ndo, stp_bpdu, length); |
| } else if (protocol_version == STP_PROTO_MSTP || |
| protocol_version == STP_PROTO_SPB) { |
| if (length < STP_BPDU_MSTP_MIN_LEN) { |
| goto invalid; |
| } |
| |
| if (GET_U_1(stp_bpdu->v1_length) != 0) { |
| /* FIX ME: Emit a message here ? */ |
| goto invalid; |
| } |
| |
| /* Validate v3 length */ |
| mstp_len = GET_BE_U_2(p + MST_BPDU_VER3_LEN_OFFSET); |
| mstp_len += 2; /* length encoding itself is 2 bytes */ |
| if (length < (sizeof(struct stp_bpdu_) + mstp_len)) { |
| goto invalid; |
| } |
| stp_print_mstp_bpdu(ndo, stp_bpdu, length); |
| |
| if (protocol_version == STP_PROTO_SPB) |
| { |
| /* Validate v4 length */ |
| spb_len = GET_BE_U_2(p + MST_BPDU_VER3_LEN_OFFSET + mstp_len); |
| spb_len += 2; |
| if (length < (sizeof(struct stp_bpdu_) + mstp_len + spb_len) || |
| spb_len < SPB_BPDU_MIN_LEN) { |
| goto invalid; |
| } |
| stp_print_spb_bpdu(ndo, stp_bpdu, (sizeof(struct stp_bpdu_) + mstp_len)); |
| } |
| } |
| break; |
| |
| case STP_BPDU_TYPE_TOPO_CHANGE: |
| /* always empty message - just break out */ |
| break; |
| |
| default: |
| break; |
| } |
| return; |
| |
| invalid: |
| nd_print_invalid(ndo); |
| } |
