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-rw-r--r--print-stp.c471
1 files changed, 471 insertions, 0 deletions
diff --git a/print-stp.c b/print-stp.c
new file mode 100644
index 0000000..a4d49c4
--- /dev/null
+++ b/print-stp.c
@@ -0,0 +1,471 @@
+/*
+ * 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 type
+ * 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);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-17 00:03:32 +0000