-/* Copyright (c) 2008 The Board of Trustees of The Leland Stanford
+/* Copyright (c) 2008, 2009 The Board of Trustees of The Leland Stanford
* Junior University
*
* We are making the OpenFlow specification and associated documentation
#include <assert.h>
#include <inttypes.h>
#include <stdlib.h>
+#include "ofpbuf.h"
#include "packets.h"
#include "util.h"
#include "xtoxll.h"
int bridge_max_age; /* 8.5.3.8: max_age when we're root. */
int bridge_hello_time; /* 8.5.3.9: hello_time as root. */
int bridge_forward_delay; /* 8.5.3.10: forward_delay as root. */
+ int rq_max_age; /* User-requested max age, in ms. */
+ int rq_hello_time; /* User-requested hello time, in ms. */
+ int rq_forward_delay; /* User-requested forward delay, in ms. */
+ int elapsed_remainder; /* Left-over msecs from last stp_tick(). */
/* Dynamic bridge data. */
stp_identifier designated_root; /* 8.5.3.1: Bridge believed to be root. */
/* Interface to client. */
struct stp_port *first_changed_port;
- void (*send_bpdu)(const void *bpdu, size_t bpdu_size,
- int port_no, void *aux);
+ void (*send_bpdu)(struct ofpbuf *bpdu, int port_no, void *aux);
void *aux;
};
return NULL;
}
-#define SECONDS_TO_TIMER(SECS) ((SECS) * 0x100)
-
#define MESSAGE_AGE_INCREMENT 1
static void stp_transmit_config(struct stp_port *);
static void stp_topology_change_timer_expiry(struct stp *);
static void stp_hold_timer_expiry(struct stp_port *);
static void stp_initialize_port(struct stp_port *, enum stp_state);
-static void stp_become_root_bridge(struct stp *stp);
+static void stp_become_root_bridge(struct stp *);
+static void stp_update_bridge_timers(struct stp *);
+static int clamp(int x, int min, int max);
+static int ms_to_timer(int ms);
+static int ms_to_timer_remainder(int ms);
+static int timer_to_ms(int timer);
static void stp_start_timer(struct stp_timer *, int value);
static void stp_stop_timer(struct stp_timer *);
static bool stp_timer_expired(struct stp_timer *, int elapsed, int timeout);
-/* Creates and returns a new STP instance that initially has no port enabled.
+static void stp_send_bpdu(struct stp_port *, const void *, size_t);
+
+/* Creates and returns a new STP instance that initially has no ports enabled.
*
* 'bridge_id' should be a 48-bit MAC address as returned by
* eth_addr_to_uint64(). 'bridge_id' may also have a priority value in its top
- * 16 bits; if those bits are set to 0, the default bridge priority of 32768 is
- * used. (This priority may be changed with stp_set_bridge_priority().)
+ * 16 bits; if those bits are set to 0, STP_DEFAULT_BRIDGE_PRIORITY is used.
+ * (This priority may be changed with stp_set_bridge_priority().)
*
- * When the bridge needs to send out a BPDU, it calls 'send_bpdu', passing
- * 'aux' as auxiliary data. This callback may be called from stp_tick() or
- * stp_received_bpdu().
+ * When the bridge needs to send out a BPDU, it calls 'send_bpdu'. This
+ * callback may be called from stp_tick() or stp_received_bpdu(). The
+ * arguments to 'send_bpdu' are an STP BPDU encapsulated in
*/
struct stp *
stp_create(const char *name, stp_identifier bridge_id,
- void (*send_bpdu)(const void *bpdu, size_t bpdu_size,
- int port_no, void *aux),
+ void (*send_bpdu)(struct ofpbuf *bpdu, int port_no, void *aux),
void *aux)
{
struct stp *stp;
stp->name = xstrdup(name);
stp->bridge_id = bridge_id;
if (!(stp->bridge_id >> 48)) {
- stp->bridge_id |= UINT64_C(32768) << 48;
+ stp->bridge_id |= (uint64_t) STP_DEFAULT_BRIDGE_PRIORITY << 48;
}
- stp->max_age = SECONDS_TO_TIMER(6);
- stp->hello_time = SECONDS_TO_TIMER(2);
- stp->forward_delay = SECONDS_TO_TIMER(4);
- stp->bridge_max_age = stp->max_age;
- stp->bridge_hello_time = stp->hello_time;
- stp->bridge_forward_delay = stp->forward_delay;
- /* Verify constraints stated by 802.1D. */
- assert(2 * (stp->forward_delay - SECONDS_TO_TIMER(1)) >= stp->max_age);
- assert(stp->max_age >= 2 * (stp->hello_time + SECONDS_TO_TIMER(1)));
+ stp->rq_max_age = 6000;
+ stp->rq_hello_time = 2000;
+ stp->rq_forward_delay = 4000;
+ stp_update_bridge_timers(stp);
+ stp->max_age = stp->bridge_max_age;
+ stp->hello_time = stp->bridge_hello_time;
+ stp->forward_delay = stp->bridge_forward_delay;
stp->designated_root = stp->bridge_id;
stp->root_path_cost = 0;
stp->first_changed_port = &stp->ports[ARRAY_SIZE(stp->ports)];
for (p = stp->ports; p < &stp->ports[ARRAY_SIZE(stp->ports)]; p++) {
p->stp = stp;
- p->port_id = (stp_port_no(p) + 1) | (128 << 8);
+ p->port_id = (stp_port_no(p) + 1) | (STP_DEFAULT_PORT_PRIORITY << 8);
p->path_cost = 19; /* Recommended default for 100 Mb/s link. */
stp_initialize_port(p, STP_DISABLED);
}
free(stp);
}
+/* Runs 'stp' given that 'ms' milliseconds have passed. */
void
-stp_tick(struct stp *stp, int elapsed)
+stp_tick(struct stp *stp, int ms)
{
struct stp_port *p;
+ int elapsed;
+
+ /* Convert 'ms' to STP timer ticks. Preserve any leftover milliseconds
+ * from previous stp_tick() calls so that we don't lose STP ticks when we
+ * are called too frequently. */
+ ms = clamp(ms, 0, INT_MAX - 1000) + stp->elapsed_remainder;
+ elapsed = ms_to_timer(ms);
+ stp->elapsed_remainder = ms_to_timer_remainder(ms);
+ if (!elapsed) {
+ return;
+ }
if (stp_timer_expired(&stp->hello_timer, elapsed, stp->hello_time)) {
stp_hello_timer_expiry(stp);
stp->forward_delay)) {
stp_forward_delay_timer_expiry(p);
}
- if (stp_timer_expired(&p->hold_timer, elapsed, SECONDS_TO_TIMER(1))) {
+ if (stp_timer_expired(&p->hold_timer, elapsed, ms_to_timer(1000))) {
stp_hold_timer_expiry(p);
}
}
| ((uint64_t) new_priority << 48)));
}
+/* Sets the desired hello time for 'stp' to 'ms', in milliseconds. The actual
+ * hello time is clamped to the range of 1 to 10 seconds and subject to the
+ * relationship (bridge_max_age >= 2 * (bridge_hello_time + 1 s)). The bridge
+ * hello time is only used when 'stp' is the root bridge. */
+void
+stp_set_hello_time(struct stp *stp, int ms)
+{
+ stp->rq_hello_time = ms;
+ stp_update_bridge_timers(stp);
+}
+
+/* Sets the desired max age for 'stp' to 'ms', in milliseconds. The actual max
+ * age is clamped to the range of 6 to 40 seconds and subject to the
+ * relationships (2 * (bridge_forward_delay - 1 s) >= bridge_max_age) and
+ * (bridge_max_age >= 2 * (bridge_hello_time + 1 s)). The bridge max age is
+ * only used when 'stp' is the root bridge. */
+void
+stp_set_max_age(struct stp *stp, int ms)
+{
+ stp->rq_max_age = ms;
+ stp_update_bridge_timers(stp);
+}
+
+/* Sets the desired forward delay for 'stp' to 'ms', in milliseconds. The
+ * actual forward delay is clamped to the range of 4 to 30 seconds and subject
+ * to the relationship (2 * (bridge_forward_delay - 1 s) >= bridge_max_age).
+ * The bridge forward delay is only used when 'stp' is the root bridge. */
+void
+stp_set_forward_delay(struct stp *stp, int ms)
+{
+ stp->rq_forward_delay = ms;
+ stp_update_bridge_timers(stp);
+}
+
/* Returns the name given to 'stp' in the call to stp_create(). */
const char *
stp_get_name(const struct stp *stp)
return stp->root_path_cost;
}
+/* Returns the bridge hello time, in ms. The returned value is not necessarily
+ * the value passed to stp_set_hello_time(): it is clamped to the valid range
+ * and quantized to the STP timer resolution. */
+int
+stp_get_hello_time(const struct stp *stp)
+{
+ return timer_to_ms(stp->bridge_hello_time);
+}
+
+/* Returns the bridge max age, in ms. The returned value is not necessarily
+ * the value passed to stp_set_max_age(): it is clamped to the valid range,
+ * quantized to the STP timer resolution, and adjusted to match the constraints
+ * due to the hello time. */
+int
+stp_get_max_age(const struct stp *stp)
+{
+ return timer_to_ms(stp->bridge_max_age);
+}
+
+/* Returns the bridge forward delay, in ms. The returned value is not
+ * necessarily the value passed to stp_set_forward_delay(): it is clamped to
+ * the valid range, quantized to the STP timer resolution, and adjusted to
+ * match the constraints due to the forward delay. */
+int
+stp_get_forward_delay(const struct stp *stp)
+{
+ return timer_to_ms(stp->bridge_forward_delay);
+}
+
/* Returns the port in 'stp' with index 'port_no', which must be between 0 and
* STP_MAX_PORTS. */
struct stp_port *
}
/* Returns true if 'state' is one in which packets received on a port should
- * be forwarded, false otherwise. */
+ * be forwarded, false otherwise.
+ *
+ * Returns true if 'state' is STP_DISABLED, since presumably in that case the
+ * port should still work, just not have STP applied to it. */
bool
stp_forward_in_state(enum stp_state state)
{
- return state == STP_FORWARDING;
+ return (state & (STP_DISABLED | STP_FORWARDING)) != 0;
}
/* Returns true if 'state' is one in which MAC learning should be done on
- * packets received on a port, false otherwise. */
+ * packets received on a port, false otherwise.
+ *
+ * Returns true if 'state' is STP_DISABLED, since presumably in that case the
+ * port should still work, just not have STP applied to it. */
bool
stp_learn_in_state(enum stp_state state)
{
- return state & (STP_LEARNING | STP_FORWARDING);
+ return (state & (STP_DISABLED | STP_LEARNING | STP_FORWARDING)) != 0;
}
/* Notifies the STP entity that bridge protocol data unit 'bpdu', which is
* used to indicate faster links. Use stp_port_set_speed() to automatically
* generate a default path cost from a link speed. */
void
-stp_port_set_path_cost(struct stp_port *p, unsigned int path_cost)
+stp_port_set_path_cost(struct stp_port *p, uint16_t path_cost)
{
if (p->path_cost != path_cost) {
struct stp *stp = p->stp;
if (ntohs(config.message_age) < stp->max_age) {
p->topology_change_ack = false;
p->config_pending = false;
- stp->send_bpdu(&config, sizeof config, stp_port_no(p), stp->aux);
+ stp_send_bpdu(p, &config, sizeof config);
stp_start_timer(&p->hold_timer, 0);
}
}
tcn_bpdu.header.protocol_id = htons(STP_PROTOCOL_ID);
tcn_bpdu.header.protocol_version = STP_PROTOCOL_VERSION;
tcn_bpdu.header.bpdu_type = STP_TYPE_TCN;
- stp->send_bpdu(&tcn_bpdu, sizeof tcn_bpdu, stp_port_no(p), stp->aux);
+ stp_send_bpdu(p, &tcn_bpdu, sizeof tcn_bpdu);
}
static void
return false;
}
+/* Returns the number of whole STP timer ticks in 'ms' milliseconds. There
+ * are 256 STP timer ticks per second. */
+static int
+ms_to_timer(int ms)
+{
+ return ms * 0x100 / 1000;
+}
+
+/* Returns the number of leftover milliseconds when 'ms' is converted to STP
+ * timer ticks. */
+static int
+ms_to_timer_remainder(int ms)
+{
+ return ms * 0x100 % 1000;
+}
+
+/* Returns the number of whole milliseconds in 'timer' STP timer ticks. There
+ * are 256 STP timer ticks per second. */
+static int
+timer_to_ms(int timer)
+{
+ return timer * 1000 / 0x100;
+}
+
+static int
+clamp(int x, int min, int max)
+{
+ return x < min ? min : x > max ? max : x;
+}
+
+static void
+stp_update_bridge_timers(struct stp *stp)
+{
+ int ht, ma, fd;
+
+ ht = clamp(stp->rq_hello_time, 1000, 10000);
+ ma = clamp(stp->rq_max_age, MAX(2 * (ht + 1000), 6000), 40000);
+ fd = clamp(stp->rq_forward_delay, ma / 2 + 1000, 30000);
+
+ stp->bridge_hello_time = ms_to_timer(ht);
+ stp->bridge_max_age = ms_to_timer(ma);
+ stp->bridge_forward_delay = ms_to_timer(fd);
+
+ if (stp_is_root_bridge(stp)) {
+ stp->max_age = stp->bridge_max_age;
+ stp->hello_time = stp->bridge_hello_time;
+ stp->forward_delay = stp->bridge_forward_delay;
+ }
+}
+
+static void
+stp_send_bpdu(struct stp_port *p, const void *bpdu, size_t bpdu_size)
+{
+ struct eth_header *eth;
+ struct llc_header *llc;
+ struct ofpbuf *pkt;
+
+ /* Skeleton. */
+ pkt = ofpbuf_new(ETH_HEADER_LEN + LLC_HEADER_LEN + bpdu_size);
+ pkt->l2 = eth = ofpbuf_put_zeros(pkt, sizeof *eth);
+ llc = ofpbuf_put_zeros(pkt, sizeof *llc);
+ pkt->l3 = ofpbuf_put(pkt, bpdu, bpdu_size);
+
+ /* 802.2 header. */
+ memcpy(eth->eth_dst, stp_eth_addr, ETH_ADDR_LEN);
+ /* p->stp->send_bpdu() must fill in source address. */
+ eth->eth_type = htons(pkt->size - ETH_HEADER_LEN);
+
+ /* LLC header. */
+ llc->llc_dsap = STP_LLC_DSAP;
+ llc->llc_ssap = STP_LLC_SSAP;
+ llc->llc_cntl = STP_LLC_CNTL;
+
+ p->stp->send_bpdu(pkt, stp_port_no(p), p->stp->aux);
+}
#include "compiler.h"
#include "util.h"
+struct ofpbuf;
+
/* Ethernet address used as the destination for STP frames. */
extern const uint8_t stp_eth_addr[6];
#define STP_LLC_DSAP 0x42
#define STP_LLC_CNTL 0x03
+/* Bridge and port priorities that should be used by default. */
+#define STP_DEFAULT_BRIDGE_PRIORITY 32768
+#define STP_DEFAULT_PORT_PRIORITY 128
+
/* 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;
/* Basic STP functionality. */
#define STP_MAX_PORTS 255
struct stp *stp_create(const char *name, stp_identifier bridge_id,
- void (*send_bpdu)(const void *bpdu, size_t bpdu_size,
- int port_no, void *aux),
+ void (*send_bpdu)(struct ofpbuf *bpdu, int port_no,
+ void *aux),
void *aux);
void stp_destroy(struct stp *);
-void stp_tick(struct stp *, int elapsed);
+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_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 *);
/* Obtaining STP ports. */
struct stp_port *stp_get_port(struct stp *, int port_no);
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);
-void stp_port_set_path_cost(struct stp_port *, unsigned int path_cost);
+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 *);
struct port_watcher *pw;
struct rconn *local_rconn;
struct rconn *remote_rconn;
- long long int last_tick_256ths;
+ long long int last_tick;
int n_txq;
};
return true;
}
-static long long int
-time_256ths(void)
-{
- return time_msec() * 256 / 1000;
-}
-
static void
stp_periodic_cb(void *stp_)
{
struct stp_data *stp = stp_;
- long long int now_256ths = time_256ths();
- long long int elapsed_256ths = now_256ths - stp->last_tick_256ths;
+ long long int now = time_msec();
+ long long int elapsed = now - stp->last_tick;
struct stp_port *p;
if (!port_watcher_is_ready(stp->pw)) {
* disable STP. */
return;
}
- if (elapsed_256ths <= 0) {
+ if (elapsed <= 0) {
return;
}
- stp_tick(stp->stp, MIN(INT_MAX, elapsed_256ths));
- stp->last_tick_256ths = now_256ths;
+ stp_tick(stp->stp, MIN(INT_MAX, elapsed));
+ stp->last_tick = now;
while (stp_get_changed_port(stp->stp, &p)) {
int port_no = stp_port_no(p);
}
static void
-send_bpdu(const void *bpdu, size_t bpdu_size, int port_no, void *stp_)
+send_bpdu(struct ofpbuf *pkt, int port_no, void *stp_)
{
struct stp_data *stp = stp_;
- const uint8_t *port_mac;
- struct eth_header *eth;
- struct llc_header *llc;
- struct ofpbuf pkt, *opo;
+ const uint8_t *port_mac = port_watcher_get_hwaddr(stp->pw, port_no);
+ if (port_mac) {
+ struct eth_header *eth = pkt->l2;
+ struct ofpbuf *opo;
+
+ memcpy(eth->eth_src, port_mac, ETH_ADDR_LEN);
+ opo = make_unbuffered_packet_out(pkt, OFPP_NONE, port_no);
- port_mac = port_watcher_get_hwaddr(stp->pw, port_no);
- if (!port_mac) {
+ rconn_send_with_limit(stp->local_rconn, opo, &stp->n_txq, OFPP_MAX);
+ } else {
VLOG_WARN_RL(&rl, "cannot send BPDU on missing port %d", port_no);
- return;
}
-
- /* Packet skeleton. */
- ofpbuf_init(&pkt, ETH_HEADER_LEN + LLC_HEADER_LEN + bpdu_size);
- eth = ofpbuf_put_uninit(&pkt, sizeof *eth);
- llc = ofpbuf_put_uninit(&pkt, sizeof *llc);
- ofpbuf_put(&pkt, bpdu, bpdu_size);
-
- /* 802.2 header. */
- memcpy(eth->eth_dst, stp_eth_addr, ETH_ADDR_LEN);
- memcpy(eth->eth_src, port_mac, ETH_ADDR_LEN);
- eth->eth_type = htons(pkt.size - ETH_HEADER_LEN);
-
- /* LLC header. */
- llc->llc_dsap = STP_LLC_DSAP;
- llc->llc_ssap = STP_LLC_SSAP;
- llc->llc_cntl = STP_LLC_CNTL;
-
- opo = make_unbuffered_packet_out(&pkt, OFPP_NONE, port_no);
- ofpbuf_uninit(&pkt);
- rconn_send_with_limit(stp->local_rconn, opo, &stp->n_txq, OFPP_MAX);
+ ofpbuf_delete(pkt);
}
static bool
stp->pw = pw;
stp->local_rconn = local;
stp->remote_rconn = remote;
- stp->last_tick_256ths = time_256ths();
+ stp->last_tick = time_msec();
port_watcher_register_callback(pw, stp_port_changed_cb, stp);
port_watcher_register_local_port_callback(pw, stp_local_port_changed_cb,
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