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/*
* Copyright (c) 2008, 2011 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef STP_H
#define STP_H 1
/* This is an implementation of Spanning Tree Protocol as described in IEEE
* 802.1D-1998, clauses 8 and 9. Section numbers refer to this standard. */
#include <stdbool.h>
#include <stdint.h>
#include "compiler.h"
#include "util.h"
struct dp_packet;
/* Bridge and port priorities that should be used by default. */
#define STP_DEFAULT_BRIDGE_PRIORITY 32768
#define STP_DEFAULT_PORT_PRIORITY 128
/* Default time values. */
#define STP_DEFAULT_MAX_AGE 20000
#define STP_DEFAULT_HELLO_TIME 2000
#define STP_DEFAULT_FWD_DELAY 15000
/* Bridge identifier. Top 16 bits are a priority value (numerically lower
* values are higher priorities). Bottom 48 bits are MAC address of bridge. */
typedef uint64_t stp_identifier;
#define STP_ID_FMT "%04"PRIx16".%012"PRIx64
#define STP_ID_ARGS(stp_id) \
(uint16_t)((stp_id) >> 48), \
(uint64_t)((stp_id) & 0xffffffffffffULL)
#define STP_PORT_ID_FMT "%04"PRIx16
/* Basic STP functionality. */
#define STP_MAX_PORTS 255
void stp_init(void);
struct stp *stp_create(const char *name, stp_identifier bridge_id,
void (*send_bpdu)(struct dp_packet *bpdu, int port_no,
void *aux),
void *aux);
struct stp *stp_ref(const struct stp *);
void stp_unref(struct stp *);
void stp_tick(struct stp *, int ms);
void stp_set_bridge_id(struct stp *, stp_identifier bridge_id);
void stp_set_bridge_priority(struct stp *, uint16_t new_priority);
void stp_set_hello_time(struct stp *, int ms);
void stp_set_max_age(struct stp *, int ms);
void stp_set_forward_delay(struct stp *, int ms);
/* STP properties. */
const char *stp_get_name(const struct stp *);
stp_identifier stp_get_bridge_id(const struct stp *);
stp_identifier stp_get_designated_root(const struct stp *);
bool stp_is_root_bridge(const struct stp *);
int stp_get_root_path_cost(const struct stp *);
int stp_get_hello_time(const struct stp *);
int stp_get_max_age(const struct stp *);
int stp_get_forward_delay(const struct stp *);
bool stp_check_and_reset_fdb_flush(struct stp *);
/* Obtaining STP ports. */
struct stp_port *stp_get_port(struct stp *, int port_no);
struct stp_port *stp_get_root_port(struct stp *);
bool stp_get_changed_port(struct stp *, struct stp_port **portp);
/* State of an STP port.
*
* A port is in exactly one state at any given time, but distinct bits are used
* for states to allow testing for more than one state with a bit mask.
*
* The STP_DISABLED state means that the port is disabled by management.
* In our implementation, this state means that the port does not
* participate in the spanning tree, but it still forwards traffic as if
* it were in the STP_FORWARDING state. This may be different from
* other implementations.
*
* The following diagram describes the various states and what they are
* allowed to do in OVS:
*
* FWD LRN TX_BPDU RX_BPDU FWD_BPDU
* --- --- ------- ------- --------
* Disabled Y - - - Y
* Blocking - - - Y -
* Listening - - Y Y Y
* Learning - Y Y Y Y
* Forwarding Y Y Y Y Y
*
*
* FWD: the port should forward any incoming non-stp-BPDU
* packets.
*
* LRN: the port should conduct MAC learning on packets received.
*
* TX_BPDU/RX_BPDU: the port could generate/consume bpdus.
*
* FWD_BPDU: the port should should always forward the BPDUS,
* whether they are generated by the port or received
* as incoming packets.
*
* Once again, note that the disabled state forwards traffic, which is
* likely different than the spec would indicate.
*/
enum stp_state {
STP_DISABLED = 1 << 0, /* 8.4.5: See note above. */
STP_LISTENING = 1 << 1, /* 8.4.2: Not learning or relaying frames. */
STP_LEARNING = 1 << 2, /* 8.4.3: Learning but not relaying frames. */
STP_FORWARDING = 1 << 3, /* 8.4.4: Learning and relaying frames. */
STP_BLOCKING = 1 << 4 /* 8.4.1: Initial boot state. */
};
const char *stp_state_name(enum stp_state);
bool stp_forward_in_state(enum stp_state);
bool stp_learn_in_state(enum stp_state);
bool stp_should_forward_bpdu(enum stp_state);
/* Role of an STP port. */
enum stp_role {
STP_ROLE_ROOT, /* Path to root bridge. */
STP_ROLE_DESIGNATED, /* Path to LAN segments. */
STP_ROLE_ALTERNATE, /* Backup path to root bridge. */
STP_ROLE_DISABLED /* Port does not participate in STP. */
};
const char *stp_role_name(enum stp_role);
void stp_received_bpdu(struct stp_port *, const void *bpdu, size_t bpdu_size);
struct stp *stp_port_get_stp(struct stp_port *);
void stp_port_set_name(struct stp_port *, const char *);
void stp_port_set_aux(struct stp_port *, void *);
void *stp_port_get_aux(struct stp_port *);
int stp_port_no(const struct stp_port *);
enum stp_state stp_port_get_state(const struct stp_port *);
void stp_port_get_counts(const struct stp_port *,
int *tx_count, int *rx_count, int *error_count);
void stp_port_get_status(const struct stp_port *p,
int *port_id, enum stp_state *state, enum stp_role *role);
void stp_port_enable(struct stp_port *);
void stp_port_disable(struct stp_port *);
void stp_port_set_priority(struct stp_port *, uint8_t new_priority);
uint16_t stp_convert_speed_to_cost(unsigned int speed);
void stp_port_set_path_cost(struct stp_port *, uint16_t path_cost);
void stp_port_set_speed(struct stp_port *, unsigned int speed);
void stp_port_enable_change_detection(struct stp_port *);
void stp_port_disable_change_detection(struct stp_port *);
#endif /* stp.h */
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