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829a7d02 | 1 | /* |
ebc56baa | 2 | * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc. |
829a7d02 JP |
3 | * |
4 | * Licensed under the Apache License, Version 2.0 (the "License"); | |
5 | * you may not use this file except in compliance with the License. | |
6 | * You may obtain a copy of the License at: | |
7 | * | |
8 | * http://www.apache.org/licenses/LICENSE-2.0 | |
9 | * | |
10 | * Unless required by applicable law or agreed to in writing, software | |
11 | * distributed under the License is distributed on an "AS IS" BASIS, | |
12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
13 | * See the License for the specific language governing permissions and | |
14 | * limitations under the License. | |
15 | */ | |
16 | ||
17 | /* Based on sample implementation in 802.1D-1998. Above copyright and license | |
18 | * applies to all modifications. */ | |
19 | ||
20 | #include <config.h> | |
21 | ||
22 | #include "stp.h" | |
23 | #include <sys/types.h> | |
24 | #include <netinet/in.h> | |
25 | #include <arpa/inet.h> | |
829a7d02 JP |
26 | #include <inttypes.h> |
27 | #include <stdlib.h> | |
28 | #include "byte-order.h" | |
29 | #include "ofpbuf.h" | |
30 | #include "packets.h" | |
fe4a02e4 | 31 | #include "unixctl.h" |
829a7d02 JP |
32 | #include "util.h" |
33 | #include "vlog.h" | |
34 | ||
35 | VLOG_DEFINE_THIS_MODULE(stp); | |
36 | ||
37 | #define STP_PROTOCOL_ID 0x0000 | |
38 | #define STP_PROTOCOL_VERSION 0x00 | |
39 | #define STP_TYPE_CONFIG 0x00 | |
40 | #define STP_TYPE_TCN 0x80 | |
41 | ||
13b6bae6 | 42 | OVS_PACKED( |
829a7d02 JP |
43 | struct stp_bpdu_header { |
44 | ovs_be16 protocol_id; /* STP_PROTOCOL_ID. */ | |
45 | uint8_t protocol_version; /* STP_PROTOCOL_VERSION. */ | |
46 | uint8_t bpdu_type; /* One of STP_TYPE_*. */ | |
13b6bae6 | 47 | }); |
829a7d02 JP |
48 | BUILD_ASSERT_DECL(sizeof(struct stp_bpdu_header) == 4); |
49 | ||
50 | enum stp_config_bpdu_flags { | |
51 | STP_CONFIG_TOPOLOGY_CHANGE_ACK = 0x80, | |
52 | STP_CONFIG_TOPOLOGY_CHANGE = 0x01 | |
53 | }; | |
54 | ||
13b6bae6 | 55 | OVS_PACKED( |
829a7d02 JP |
56 | struct stp_config_bpdu { |
57 | struct stp_bpdu_header header; /* Type STP_TYPE_CONFIG. */ | |
58 | uint8_t flags; /* STP_CONFIG_* flags. */ | |
59 | ovs_be64 root_id; /* 8.5.1.1: Bridge believed to be root. */ | |
60 | ovs_be32 root_path_cost; /* 8.5.1.2: Cost of path to root. */ | |
61 | ovs_be64 bridge_id; /* 8.5.1.3: ID of transmitting bridge. */ | |
62 | ovs_be16 port_id; /* 8.5.1.4: Port transmitting the BPDU. */ | |
63 | ovs_be16 message_age; /* 8.5.1.5: Age of BPDU at tx time. */ | |
64 | ovs_be16 max_age; /* 8.5.1.6: Timeout for received data. */ | |
65 | ovs_be16 hello_time; /* 8.5.1.7: Time between BPDU generation. */ | |
66 | ovs_be16 forward_delay; /* 8.5.1.8: State progression delay. */ | |
13b6bae6 | 67 | }); |
829a7d02 JP |
68 | BUILD_ASSERT_DECL(sizeof(struct stp_config_bpdu) == 35); |
69 | ||
13b6bae6 | 70 | OVS_PACKED( |
829a7d02 JP |
71 | struct stp_tcn_bpdu { |
72 | struct stp_bpdu_header header; /* Type STP_TYPE_TCN. */ | |
13b6bae6 | 73 | }); |
829a7d02 JP |
74 | BUILD_ASSERT_DECL(sizeof(struct stp_tcn_bpdu) == 4); |
75 | ||
76 | struct stp_timer { | |
77 | bool active; /* Timer in use? */ | |
78 | int value; /* Current value of timer, counting up. */ | |
79 | }; | |
80 | ||
81 | struct stp_port { | |
82 | struct stp *stp; | |
3310b570 | 83 | void *aux; /* Auxiliary data the user may retrieve. */ |
829a7d02 JP |
84 | int port_id; /* 8.5.5.1: Unique port identifier. */ |
85 | enum stp_state state; /* 8.5.5.2: Current state. */ | |
86 | int path_cost; /* 8.5.5.3: Cost of tx/rx on this port. */ | |
87 | stp_identifier designated_root; /* 8.5.5.4. */ | |
88 | int designated_cost; /* 8.5.5.5: Path cost to root on port. */ | |
89 | stp_identifier designated_bridge; /* 8.5.5.6. */ | |
90 | int designated_port; /* 8.5.5.7: Port to send config msgs on. */ | |
91 | bool topology_change_ack; /* 8.5.5.8: Flag for next config BPDU. */ | |
92 | bool config_pending; /* 8.5.5.9: Send BPDU when hold expires? */ | |
93 | bool change_detection_enabled; /* 8.5.5.10: Detect topology changes? */ | |
94 | ||
95 | struct stp_timer message_age_timer; /* 8.5.6.1: Age of received info. */ | |
96 | struct stp_timer forward_delay_timer; /* 8.5.6.2: State change timer. */ | |
97 | struct stp_timer hold_timer; /* 8.5.6.3: BPDU rate limit timer. */ | |
98 | ||
80740385 JP |
99 | int tx_count; /* Number of BPDUs transmitted. */ |
100 | int rx_count; /* Number of valid BPDUs received. */ | |
101 | int error_count; /* Number of bad BPDUs received. */ | |
102 | ||
829a7d02 JP |
103 | bool state_changed; |
104 | }; | |
105 | ||
106 | struct stp { | |
fe4a02e4 EJ |
107 | struct list node; /* Node in all_stps list. */ |
108 | ||
829a7d02 JP |
109 | /* Static bridge data. */ |
110 | char *name; /* Human-readable name for log messages. */ | |
111 | stp_identifier bridge_id; /* 8.5.3.7: This bridge. */ | |
112 | int max_age; /* 8.5.3.4: Time to drop received data. */ | |
113 | int hello_time; /* 8.5.3.5: Time between sending BPDUs. */ | |
114 | int forward_delay; /* 8.5.3.6: Delay between state changes. */ | |
115 | int bridge_max_age; /* 8.5.3.8: max_age when we're root. */ | |
116 | int bridge_hello_time; /* 8.5.3.9: hello_time as root. */ | |
117 | int bridge_forward_delay; /* 8.5.3.10: forward_delay as root. */ | |
118 | int rq_max_age; /* User-requested max age, in ms. */ | |
119 | int rq_hello_time; /* User-requested hello time, in ms. */ | |
120 | int rq_forward_delay; /* User-requested forward delay, in ms. */ | |
121 | int elapsed_remainder; /* Left-over msecs from last stp_tick(). */ | |
122 | ||
123 | /* Dynamic bridge data. */ | |
124 | stp_identifier designated_root; /* 8.5.3.1: Bridge believed to be root. */ | |
125 | unsigned int root_path_cost; /* 8.5.3.2: Cost of path to root. */ | |
126 | struct stp_port *root_port; /* 8.5.3.3: Lowest cost port to root. */ | |
127 | bool topology_change_detected; /* 8.5.3.11: Detected a topology change? */ | |
128 | bool topology_change; /* 8.5.3.12: Received topology change? */ | |
129 | ||
130 | /* Bridge timers. */ | |
131 | struct stp_timer hello_timer; /* 8.5.4.1: Hello timer. */ | |
132 | struct stp_timer tcn_timer; /* 8.5.4.2: Topology change timer. */ | |
133 | struct stp_timer topology_change_timer; /* 8.5.4.3. */ | |
134 | ||
135 | /* Ports. */ | |
136 | struct stp_port ports[STP_MAX_PORTS]; | |
137 | ||
138 | /* Interface to client. */ | |
6ae50723 | 139 | bool fdb_needs_flush; /* MAC learning tables needs flushing. */ |
829a7d02 JP |
140 | struct stp_port *first_changed_port; |
141 | void (*send_bpdu)(struct ofpbuf *bpdu, int port_no, void *aux); | |
142 | void *aux; | |
143 | }; | |
144 | ||
fe4a02e4 EJ |
145 | static struct list all_stps = LIST_INITIALIZER(&all_stps); |
146 | ||
829a7d02 JP |
147 | #define FOR_EACH_ENABLED_PORT(PORT, STP) \ |
148 | for ((PORT) = stp_next_enabled_port((STP), (STP)->ports); \ | |
149 | (PORT); \ | |
150 | (PORT) = stp_next_enabled_port((STP), (PORT) + 1)) | |
151 | static struct stp_port * | |
152 | stp_next_enabled_port(const struct stp *stp, const struct stp_port *port) | |
153 | { | |
154 | for (; port < &stp->ports[ARRAY_SIZE(stp->ports)]; port++) { | |
155 | if (port->state != STP_DISABLED) { | |
ebc56baa | 156 | return CONST_CAST(struct stp_port *, port); |
829a7d02 JP |
157 | } |
158 | } | |
159 | return NULL; | |
160 | } | |
161 | ||
162 | #define MESSAGE_AGE_INCREMENT 1 | |
163 | ||
164 | static void stp_transmit_config(struct stp_port *); | |
165 | static bool stp_supersedes_port_info(const struct stp_port *, | |
166 | const struct stp_config_bpdu *); | |
167 | static void stp_record_config_information(struct stp_port *, | |
168 | const struct stp_config_bpdu *); | |
169 | static void stp_record_config_timeout_values(struct stp *, | |
170 | const struct stp_config_bpdu *); | |
171 | static bool stp_is_designated_port(const struct stp_port *); | |
172 | static void stp_config_bpdu_generation(struct stp *); | |
173 | static void stp_transmit_tcn(struct stp *); | |
174 | static void stp_configuration_update(struct stp *); | |
175 | static bool stp_supersedes_root(const struct stp_port *root, | |
176 | const struct stp_port *); | |
177 | static void stp_root_selection(struct stp *); | |
178 | static void stp_designated_port_selection(struct stp *); | |
179 | static void stp_become_designated_port(struct stp_port *); | |
180 | static void stp_port_state_selection(struct stp *); | |
181 | static void stp_make_forwarding(struct stp_port *); | |
182 | static void stp_make_blocking(struct stp_port *); | |
183 | static void stp_set_port_state(struct stp_port *, enum stp_state); | |
184 | static void stp_topology_change_detection(struct stp *); | |
185 | static void stp_topology_change_acknowledged(struct stp *); | |
186 | static void stp_acknowledge_topology_change(struct stp_port *); | |
187 | static void stp_received_config_bpdu(struct stp *, struct stp_port *, | |
188 | const struct stp_config_bpdu *); | |
189 | static void stp_received_tcn_bpdu(struct stp *, struct stp_port *); | |
190 | static void stp_hello_timer_expiry(struct stp *); | |
191 | static void stp_message_age_timer_expiry(struct stp_port *); | |
192 | static bool stp_is_designated_for_some_port(const struct stp *); | |
193 | static void stp_forward_delay_timer_expiry(struct stp_port *); | |
194 | static void stp_tcn_timer_expiry(struct stp *); | |
195 | static void stp_topology_change_timer_expiry(struct stp *); | |
196 | static void stp_hold_timer_expiry(struct stp_port *); | |
197 | static void stp_initialize_port(struct stp_port *, enum stp_state); | |
198 | static void stp_become_root_bridge(struct stp *); | |
199 | static void stp_update_bridge_timers(struct stp *); | |
200 | ||
201 | static int clamp(int x, int min, int max); | |
202 | static int ms_to_timer(int ms); | |
829a7d02 JP |
203 | static int timer_to_ms(int timer); |
204 | static void stp_start_timer(struct stp_timer *, int value); | |
205 | static void stp_stop_timer(struct stp_timer *); | |
206 | static bool stp_timer_expired(struct stp_timer *, int elapsed, int timeout); | |
207 | ||
208 | static void stp_send_bpdu(struct stp_port *, const void *, size_t); | |
fe4a02e4 EJ |
209 | static void stp_unixctl_tcn(struct unixctl_conn *, int argc, |
210 | const char *argv[], void *aux); | |
211 | ||
212 | void | |
213 | stp_init(void) | |
214 | { | |
215 | unixctl_command_register("stp/tcn", "[bridge]", 0, 1, stp_unixctl_tcn, | |
216 | NULL); | |
217 | } | |
829a7d02 JP |
218 | |
219 | /* Creates and returns a new STP instance that initially has no ports enabled. | |
220 | * | |
221 | * 'bridge_id' should be a 48-bit MAC address as returned by | |
222 | * eth_addr_to_uint64(). 'bridge_id' may also have a priority value in its top | |
223 | * 16 bits; if those bits are set to 0, STP_DEFAULT_BRIDGE_PRIORITY is used. | |
224 | * (This priority may be changed with stp_set_bridge_priority().) | |
225 | * | |
226 | * When the bridge needs to send out a BPDU, it calls 'send_bpdu'. This | |
227 | * callback may be called from stp_tick() or stp_received_bpdu(). The | |
228 | * arguments to 'send_bpdu' are an STP BPDU encapsulated in 'bpdu', | |
229 | * the spanning tree port number 'port_no' that should transmit the | |
230 | * packet, and auxiliary data to be passed to the callback in 'aux'. | |
231 | */ | |
232 | struct stp * | |
233 | stp_create(const char *name, stp_identifier bridge_id, | |
234 | void (*send_bpdu)(struct ofpbuf *bpdu, int port_no, void *aux), | |
235 | void *aux) | |
236 | { | |
237 | struct stp *stp; | |
238 | struct stp_port *p; | |
239 | ||
240 | stp = xzalloc(sizeof *stp); | |
241 | stp->name = xstrdup(name); | |
242 | stp->bridge_id = bridge_id; | |
243 | if (!(stp->bridge_id >> 48)) { | |
244 | stp->bridge_id |= (uint64_t) STP_DEFAULT_BRIDGE_PRIORITY << 48; | |
245 | } | |
246 | ||
3310b570 JP |
247 | stp->rq_max_age = STP_DEFAULT_MAX_AGE; |
248 | stp->rq_hello_time = STP_DEFAULT_HELLO_TIME; | |
249 | stp->rq_forward_delay = STP_DEFAULT_FWD_DELAY; | |
829a7d02 JP |
250 | stp_update_bridge_timers(stp); |
251 | stp->max_age = stp->bridge_max_age; | |
252 | stp->hello_time = stp->bridge_hello_time; | |
253 | stp->forward_delay = stp->bridge_forward_delay; | |
254 | ||
255 | stp->designated_root = stp->bridge_id; | |
256 | stp->root_path_cost = 0; | |
257 | stp->root_port = NULL; | |
258 | stp->topology_change_detected = false; | |
259 | stp->topology_change = false; | |
260 | ||
261 | stp_stop_timer(&stp->tcn_timer); | |
262 | stp_stop_timer(&stp->topology_change_timer); | |
263 | stp_start_timer(&stp->hello_timer, 0); | |
264 | ||
265 | stp->send_bpdu = send_bpdu; | |
266 | stp->aux = aux; | |
267 | ||
268 | stp->first_changed_port = &stp->ports[ARRAY_SIZE(stp->ports)]; | |
269 | for (p = stp->ports; p < &stp->ports[ARRAY_SIZE(stp->ports)]; p++) { | |
270 | p->stp = stp; | |
271 | p->port_id = (stp_port_no(p) + 1) | (STP_DEFAULT_PORT_PRIORITY << 8); | |
272 | p->path_cost = 19; /* Recommended default for 100 Mb/s link. */ | |
273 | stp_initialize_port(p, STP_DISABLED); | |
274 | } | |
fe4a02e4 | 275 | list_push_back(&all_stps, &stp->node); |
829a7d02 JP |
276 | return stp; |
277 | } | |
278 | ||
279 | /* Destroys 'stp'. */ | |
280 | void | |
281 | stp_destroy(struct stp *stp) | |
282 | { | |
283 | if (stp) { | |
fe4a02e4 | 284 | list_remove(&stp->node); |
829a7d02 JP |
285 | free(stp->name); |
286 | free(stp); | |
287 | } | |
288 | } | |
289 | ||
290 | /* Runs 'stp' given that 'ms' milliseconds have passed. */ | |
291 | void | |
292 | stp_tick(struct stp *stp, int ms) | |
293 | { | |
294 | struct stp_port *p; | |
295 | int elapsed; | |
296 | ||
297 | /* Convert 'ms' to STP timer ticks. Preserve any leftover milliseconds | |
298 | * from previous stp_tick() calls so that we don't lose STP ticks when we | |
299 | * are called too frequently. */ | |
300 | ms = clamp(ms, 0, INT_MAX - 1000) + stp->elapsed_remainder; | |
301 | elapsed = ms_to_timer(ms); | |
ba25773f | 302 | stp->elapsed_remainder = ms - timer_to_ms(elapsed); |
829a7d02 JP |
303 | if (!elapsed) { |
304 | return; | |
305 | } | |
306 | ||
307 | if (stp_timer_expired(&stp->hello_timer, elapsed, stp->hello_time)) { | |
308 | stp_hello_timer_expiry(stp); | |
309 | } | |
310 | if (stp_timer_expired(&stp->tcn_timer, elapsed, stp->bridge_hello_time)) { | |
311 | stp_tcn_timer_expiry(stp); | |
312 | } | |
313 | if (stp_timer_expired(&stp->topology_change_timer, elapsed, | |
314 | stp->max_age + stp->forward_delay)) { | |
315 | stp_topology_change_timer_expiry(stp); | |
316 | } | |
317 | FOR_EACH_ENABLED_PORT (p, stp) { | |
318 | if (stp_timer_expired(&p->message_age_timer, elapsed, stp->max_age)) { | |
319 | stp_message_age_timer_expiry(p); | |
320 | } | |
321 | } | |
322 | FOR_EACH_ENABLED_PORT (p, stp) { | |
323 | if (stp_timer_expired(&p->forward_delay_timer, elapsed, | |
324 | stp->forward_delay)) { | |
325 | stp_forward_delay_timer_expiry(p); | |
326 | } | |
327 | if (stp_timer_expired(&p->hold_timer, elapsed, ms_to_timer(1000))) { | |
328 | stp_hold_timer_expiry(p); | |
329 | } | |
330 | } | |
331 | } | |
332 | ||
333 | static void | |
334 | set_bridge_id(struct stp *stp, stp_identifier new_bridge_id) | |
335 | { | |
336 | if (new_bridge_id != stp->bridge_id) { | |
337 | bool root; | |
338 | struct stp_port *p; | |
339 | ||
340 | root = stp_is_root_bridge(stp); | |
341 | FOR_EACH_ENABLED_PORT (p, stp) { | |
342 | if (stp_is_designated_port(p)) { | |
343 | p->designated_bridge = new_bridge_id; | |
344 | } | |
345 | } | |
346 | stp->bridge_id = new_bridge_id; | |
347 | stp_configuration_update(stp); | |
348 | stp_port_state_selection(stp); | |
349 | if (stp_is_root_bridge(stp) && !root) { | |
350 | stp_become_root_bridge(stp); | |
351 | } | |
352 | } | |
353 | } | |
354 | ||
355 | void | |
356 | stp_set_bridge_id(struct stp *stp, stp_identifier bridge_id) | |
357 | { | |
358 | const uint64_t mac_bits = (UINT64_C(1) << 48) - 1; | |
359 | const uint64_t pri_bits = ~mac_bits; | |
360 | set_bridge_id(stp, (stp->bridge_id & pri_bits) | (bridge_id & mac_bits)); | |
361 | } | |
362 | ||
363 | void | |
364 | stp_set_bridge_priority(struct stp *stp, uint16_t new_priority) | |
365 | { | |
366 | const uint64_t mac_bits = (UINT64_C(1) << 48) - 1; | |
367 | set_bridge_id(stp, ((stp->bridge_id & mac_bits) | |
368 | | ((uint64_t) new_priority << 48))); | |
369 | } | |
370 | ||
371 | /* Sets the desired hello time for 'stp' to 'ms', in milliseconds. The actual | |
372 | * hello time is clamped to the range of 1 to 10 seconds and subject to the | |
373 | * relationship (bridge_max_age >= 2 * (bridge_hello_time + 1 s)). The bridge | |
374 | * hello time is only used when 'stp' is the root bridge. */ | |
375 | void | |
376 | stp_set_hello_time(struct stp *stp, int ms) | |
377 | { | |
378 | stp->rq_hello_time = ms; | |
379 | stp_update_bridge_timers(stp); | |
380 | } | |
381 | ||
382 | /* Sets the desired max age for 'stp' to 'ms', in milliseconds. The actual max | |
383 | * age is clamped to the range of 6 to 40 seconds and subject to the | |
384 | * relationships (2 * (bridge_forward_delay - 1 s) >= bridge_max_age) and | |
385 | * (bridge_max_age >= 2 * (bridge_hello_time + 1 s)). The bridge max age is | |
386 | * only used when 'stp' is the root bridge. */ | |
387 | void | |
388 | stp_set_max_age(struct stp *stp, int ms) | |
389 | { | |
390 | stp->rq_max_age = ms; | |
391 | stp_update_bridge_timers(stp); | |
392 | } | |
393 | ||
394 | /* Sets the desired forward delay for 'stp' to 'ms', in milliseconds. The | |
395 | * actual forward delay is clamped to the range of 4 to 30 seconds and subject | |
396 | * to the relationship (2 * (bridge_forward_delay - 1 s) >= bridge_max_age). | |
397 | * The bridge forward delay is only used when 'stp' is the root bridge. */ | |
398 | void | |
399 | stp_set_forward_delay(struct stp *stp, int ms) | |
400 | { | |
401 | stp->rq_forward_delay = ms; | |
402 | stp_update_bridge_timers(stp); | |
403 | } | |
404 | ||
405 | /* Returns the name given to 'stp' in the call to stp_create(). */ | |
406 | const char * | |
407 | stp_get_name(const struct stp *stp) | |
408 | { | |
409 | return stp->name; | |
410 | } | |
411 | ||
412 | /* Returns the bridge ID for 'stp'. */ | |
413 | stp_identifier | |
414 | stp_get_bridge_id(const struct stp *stp) | |
415 | { | |
416 | return stp->bridge_id; | |
417 | } | |
418 | ||
419 | /* Returns the bridge ID of the bridge currently believed to be the root. */ | |
420 | stp_identifier | |
421 | stp_get_designated_root(const struct stp *stp) | |
422 | { | |
423 | return stp->designated_root; | |
424 | } | |
425 | ||
426 | /* Returns true if 'stp' believes itself to the be root of the spanning tree, | |
427 | * false otherwise. */ | |
428 | bool | |
429 | stp_is_root_bridge(const struct stp *stp) | |
430 | { | |
431 | return stp->bridge_id == stp->designated_root; | |
432 | } | |
433 | ||
434 | /* Returns the cost of the path from 'stp' to the root of the spanning tree. */ | |
435 | int | |
436 | stp_get_root_path_cost(const struct stp *stp) | |
437 | { | |
438 | return stp->root_path_cost; | |
439 | } | |
440 | ||
441 | /* Returns the bridge hello time, in ms. The returned value is not necessarily | |
442 | * the value passed to stp_set_hello_time(): it is clamped to the valid range | |
443 | * and quantized to the STP timer resolution. */ | |
444 | int | |
445 | stp_get_hello_time(const struct stp *stp) | |
446 | { | |
447 | return timer_to_ms(stp->bridge_hello_time); | |
448 | } | |
449 | ||
450 | /* Returns the bridge max age, in ms. The returned value is not necessarily | |
451 | * the value passed to stp_set_max_age(): it is clamped to the valid range, | |
452 | * quantized to the STP timer resolution, and adjusted to match the constraints | |
453 | * due to the hello time. */ | |
454 | int | |
455 | stp_get_max_age(const struct stp *stp) | |
456 | { | |
457 | return timer_to_ms(stp->bridge_max_age); | |
458 | } | |
459 | ||
460 | /* Returns the bridge forward delay, in ms. The returned value is not | |
461 | * necessarily the value passed to stp_set_forward_delay(): it is clamped to | |
462 | * the valid range, quantized to the STP timer resolution, and adjusted to | |
463 | * match the constraints due to the forward delay. */ | |
464 | int | |
465 | stp_get_forward_delay(const struct stp *stp) | |
466 | { | |
467 | return timer_to_ms(stp->bridge_forward_delay); | |
468 | } | |
469 | ||
6ae50723 EJ |
470 | /* Returns true if something has happened to 'stp' which necessitates flushing |
471 | * the client's MAC learning table. Calling this function resets 'stp' so that | |
472 | * future calls will return false until flushing is required again. */ | |
473 | bool | |
474 | stp_check_and_reset_fdb_flush(struct stp *stp) | |
475 | { | |
476 | bool needs_flush = stp->fdb_needs_flush; | |
477 | stp->fdb_needs_flush = false; | |
478 | return needs_flush; | |
479 | } | |
480 | ||
829a7d02 JP |
481 | /* Returns the port in 'stp' with index 'port_no', which must be between 0 and |
482 | * STP_MAX_PORTS. */ | |
483 | struct stp_port * | |
484 | stp_get_port(struct stp *stp, int port_no) | |
485 | { | |
cb22974d | 486 | ovs_assert(port_no >= 0 && port_no < ARRAY_SIZE(stp->ports)); |
829a7d02 JP |
487 | return &stp->ports[port_no]; |
488 | } | |
489 | ||
490 | /* Returns the port connecting 'stp' to the root bridge, or a null pointer if | |
491 | * there is no such port. */ | |
492 | struct stp_port * | |
493 | stp_get_root_port(struct stp *stp) | |
494 | { | |
495 | return stp->root_port; | |
496 | } | |
497 | ||
498 | /* Finds a port whose state has changed. If successful, stores the port whose | |
499 | * state changed in '*portp' and returns true. If no port has changed, stores | |
500 | * NULL in '*portp' and returns false. */ | |
501 | bool | |
502 | stp_get_changed_port(struct stp *stp, struct stp_port **portp) | |
503 | { | |
504 | struct stp_port *end = &stp->ports[ARRAY_SIZE(stp->ports)]; | |
505 | struct stp_port *p; | |
506 | ||
507 | for (p = stp->first_changed_port; p < end; p++) { | |
508 | if (p->state_changed) { | |
509 | p->state_changed = false; | |
510 | stp->first_changed_port = p + 1; | |
511 | *portp = p; | |
512 | return true; | |
513 | } | |
514 | } | |
515 | stp->first_changed_port = end; | |
516 | *portp = NULL; | |
517 | return false; | |
518 | } | |
519 | ||
520 | /* Returns the name for the given 'state' (for use in debugging and log | |
521 | * messages). */ | |
522 | const char * | |
523 | stp_state_name(enum stp_state state) | |
524 | { | |
525 | switch (state) { | |
526 | case STP_DISABLED: | |
527 | return "disabled"; | |
528 | case STP_LISTENING: | |
529 | return "listening"; | |
530 | case STP_LEARNING: | |
531 | return "learning"; | |
532 | case STP_FORWARDING: | |
533 | return "forwarding"; | |
534 | case STP_BLOCKING: | |
535 | return "blocking"; | |
536 | default: | |
537 | NOT_REACHED(); | |
538 | } | |
539 | } | |
540 | ||
541 | /* Returns true if 'state' is one in which packets received on a port should | |
542 | * be forwarded, false otherwise. | |
543 | * | |
544 | * Returns true if 'state' is STP_DISABLED, since presumably in that case the | |
545 | * port should still work, just not have STP applied to it. */ | |
546 | bool | |
547 | stp_forward_in_state(enum stp_state state) | |
548 | { | |
549 | return (state & (STP_DISABLED | STP_FORWARDING)) != 0; | |
550 | } | |
551 | ||
552 | /* Returns true if 'state' is one in which MAC learning should be done on | |
553 | * packets received on a port, false otherwise. | |
554 | * | |
555 | * Returns true if 'state' is STP_DISABLED, since presumably in that case the | |
556 | * port should still work, just not have STP applied to it. */ | |
557 | bool | |
558 | stp_learn_in_state(enum stp_state state) | |
559 | { | |
560 | return (state & (STP_DISABLED | STP_LEARNING | STP_FORWARDING)) != 0; | |
561 | } | |
562 | ||
3310b570 JP |
563 | /* Returns the name for the given 'role' (for use in debugging and log |
564 | * messages). */ | |
565 | const char * | |
566 | stp_role_name(enum stp_role role) | |
567 | { | |
568 | switch (role) { | |
569 | case STP_ROLE_ROOT: | |
570 | return "root"; | |
571 | case STP_ROLE_DESIGNATED: | |
572 | return "designated"; | |
573 | case STP_ROLE_ALTERNATE: | |
574 | return "alternate"; | |
575 | case STP_ROLE_DISABLED: | |
576 | return "disabled"; | |
577 | default: | |
578 | NOT_REACHED(); | |
579 | } | |
580 | } | |
581 | ||
829a7d02 JP |
582 | /* Notifies the STP entity that bridge protocol data unit 'bpdu', which is |
583 | * 'bpdu_size' bytes in length, was received on port 'p'. | |
584 | * | |
585 | * This function may call the 'send_bpdu' function provided to stp_create(). */ | |
586 | void | |
587 | stp_received_bpdu(struct stp_port *p, const void *bpdu, size_t bpdu_size) | |
588 | { | |
589 | struct stp *stp = p->stp; | |
590 | const struct stp_bpdu_header *header; | |
591 | ||
592 | if (p->state == STP_DISABLED) { | |
593 | return; | |
594 | } | |
595 | ||
596 | if (bpdu_size < sizeof(struct stp_bpdu_header)) { | |
597 | VLOG_WARN("%s: received runt %zu-byte BPDU", stp->name, bpdu_size); | |
80740385 | 598 | p->error_count++; |
829a7d02 JP |
599 | return; |
600 | } | |
601 | ||
602 | header = bpdu; | |
603 | if (header->protocol_id != htons(STP_PROTOCOL_ID)) { | |
604 | VLOG_WARN("%s: received BPDU with unexpected protocol ID %"PRIu16, | |
605 | stp->name, ntohs(header->protocol_id)); | |
80740385 | 606 | p->error_count++; |
829a7d02 JP |
607 | return; |
608 | } | |
609 | if (header->protocol_version != STP_PROTOCOL_VERSION) { | |
610 | VLOG_DBG("%s: received BPDU with unexpected protocol version %"PRIu8, | |
611 | stp->name, header->protocol_version); | |
612 | } | |
613 | ||
614 | switch (header->bpdu_type) { | |
615 | case STP_TYPE_CONFIG: | |
616 | if (bpdu_size < sizeof(struct stp_config_bpdu)) { | |
617 | VLOG_WARN("%s: received config BPDU with invalid size %zu", | |
618 | stp->name, bpdu_size); | |
80740385 | 619 | p->error_count++; |
829a7d02 JP |
620 | return; |
621 | } | |
622 | stp_received_config_bpdu(stp, p, bpdu); | |
623 | break; | |
624 | ||
625 | case STP_TYPE_TCN: | |
626 | if (bpdu_size != sizeof(struct stp_tcn_bpdu)) { | |
627 | VLOG_WARN("%s: received TCN BPDU with invalid size %zu", | |
628 | stp->name, bpdu_size); | |
80740385 | 629 | p->error_count++; |
829a7d02 JP |
630 | return; |
631 | } | |
632 | stp_received_tcn_bpdu(stp, p); | |
633 | break; | |
634 | ||
635 | default: | |
636 | VLOG_WARN("%s: received BPDU of unexpected type %"PRIu8, | |
637 | stp->name, header->bpdu_type); | |
80740385 | 638 | p->error_count++; |
829a7d02 JP |
639 | return; |
640 | } | |
80740385 | 641 | p->rx_count++; |
829a7d02 JP |
642 | } |
643 | ||
644 | /* Returns the STP entity in which 'p' is nested. */ | |
645 | struct stp * | |
646 | stp_port_get_stp(struct stp_port *p) | |
647 | { | |
648 | return p->stp; | |
649 | } | |
650 | ||
3310b570 JP |
651 | /* Sets the 'aux' member of 'p'. |
652 | * | |
653 | * The 'aux' member will be reset to NULL when stp_port_disable() is | |
654 | * called or stp_port_enable() is called when the port is in a Disabled | |
655 | * state. */ | |
656 | void | |
657 | stp_port_set_aux(struct stp_port *p, void *aux) | |
658 | { | |
659 | p->aux = aux; | |
660 | } | |
661 | ||
662 | /* Returns the 'aux' member of 'p'. */ | |
663 | void * | |
664 | stp_port_get_aux(struct stp_port *p) | |
665 | { | |
666 | return p->aux; | |
667 | } | |
668 | ||
829a7d02 JP |
669 | /* Returns the index of port 'p' within its bridge. */ |
670 | int | |
671 | stp_port_no(const struct stp_port *p) | |
672 | { | |
673 | struct stp *stp = p->stp; | |
cb22974d | 674 | ovs_assert(p >= stp->ports && p < &stp->ports[ARRAY_SIZE(stp->ports)]); |
829a7d02 JP |
675 | return p - stp->ports; |
676 | } | |
677 | ||
3310b570 JP |
678 | /* Returns the port ID for 'p'. */ |
679 | int | |
680 | stp_port_get_id(const struct stp_port *p) | |
681 | { | |
682 | return p->port_id; | |
683 | } | |
684 | ||
829a7d02 JP |
685 | /* Returns the state of port 'p'. */ |
686 | enum stp_state | |
687 | stp_port_get_state(const struct stp_port *p) | |
688 | { | |
689 | return p->state; | |
690 | } | |
691 | ||
3310b570 JP |
692 | /* Returns the role of port 'p'. */ |
693 | enum stp_role | |
694 | stp_port_get_role(const struct stp_port *p) | |
695 | { | |
696 | struct stp_port *root_port = stp_get_root_port(p->stp); | |
697 | ||
698 | if (root_port && root_port->port_id == p->port_id) { | |
699 | return STP_ROLE_ROOT; | |
700 | } else if (stp_is_designated_port(p)) { | |
701 | return STP_ROLE_DESIGNATED; | |
702 | } else if (p->state == STP_DISABLED) { | |
703 | return STP_ROLE_DISABLED; | |
704 | } else { | |
705 | return STP_ROLE_ALTERNATE; | |
706 | } | |
707 | } | |
708 | ||
80740385 JP |
709 | /* Retrieves BPDU transmit and receive counts for 'p'. */ |
710 | void stp_port_get_counts(const struct stp_port *p, | |
711 | int *tx_count, int *rx_count, int *error_count) | |
712 | { | |
713 | *tx_count = p->tx_count; | |
714 | *rx_count = p->rx_count; | |
715 | *error_count = p->error_count; | |
716 | } | |
717 | ||
829a7d02 JP |
718 | /* Disables STP on port 'p'. */ |
719 | void | |
720 | stp_port_disable(struct stp_port *p) | |
721 | { | |
722 | struct stp *stp = p->stp; | |
723 | if (p->state != STP_DISABLED) { | |
724 | bool root = stp_is_root_bridge(stp); | |
725 | stp_become_designated_port(p); | |
726 | stp_set_port_state(p, STP_DISABLED); | |
727 | p->topology_change_ack = false; | |
728 | p->config_pending = false; | |
729 | stp_stop_timer(&p->message_age_timer); | |
730 | stp_stop_timer(&p->forward_delay_timer); | |
731 | stp_configuration_update(stp); | |
732 | stp_port_state_selection(stp); | |
733 | if (stp_is_root_bridge(stp) && !root) { | |
734 | stp_become_root_bridge(stp); | |
735 | } | |
3310b570 | 736 | p->aux = NULL; |
829a7d02 JP |
737 | } |
738 | } | |
739 | ||
740 | /* Enables STP on port 'p'. The port will initially be in "blocking" state. */ | |
741 | void | |
742 | stp_port_enable(struct stp_port *p) | |
743 | { | |
744 | if (p->state == STP_DISABLED) { | |
745 | stp_initialize_port(p, STP_BLOCKING); | |
746 | stp_port_state_selection(p->stp); | |
747 | } | |
748 | } | |
749 | ||
750 | /* Sets the priority of port 'p' to 'new_priority'. Lower numerical values | |
751 | * are interpreted as higher priorities. */ | |
752 | void | |
753 | stp_port_set_priority(struct stp_port *p, uint8_t new_priority) | |
754 | { | |
755 | uint16_t new_port_id = (p->port_id & 0xff) | (new_priority << 8); | |
756 | if (p->port_id != new_port_id) { | |
757 | struct stp *stp = p->stp; | |
758 | if (stp_is_designated_port(p)) { | |
759 | p->designated_port = new_port_id; | |
760 | } | |
761 | p->port_id = new_port_id; | |
762 | if (stp->bridge_id == p->designated_bridge | |
763 | && p->port_id < p->designated_port) { | |
764 | stp_become_designated_port(p); | |
765 | stp_port_state_selection(stp); | |
766 | } | |
767 | } | |
768 | } | |
769 | ||
3310b570 JP |
770 | /* Convert 'speed' (measured in Mb/s) into the path cost. */ |
771 | uint16_t | |
772 | stp_convert_speed_to_cost(unsigned int speed) | |
773 | { | |
774 | return speed >= 10000 ? 2 /* 10 Gb/s. */ | |
775 | : speed >= 1000 ? 4 /* 1 Gb/s. */ | |
776 | : speed >= 100 ? 19 /* 100 Mb/s. */ | |
777 | : speed >= 16 ? 62 /* 16 Mb/s. */ | |
778 | : speed >= 10 ? 100 /* 10 Mb/s. */ | |
779 | : speed >= 4 ? 250 /* 4 Mb/s. */ | |
780 | : 19; /* 100 Mb/s (guess). */ | |
781 | } | |
782 | ||
829a7d02 JP |
783 | /* Sets the path cost of port 'p' to 'path_cost'. Lower values are generally |
784 | * used to indicate faster links. Use stp_port_set_speed() to automatically | |
785 | * generate a default path cost from a link speed. */ | |
786 | void | |
787 | stp_port_set_path_cost(struct stp_port *p, uint16_t path_cost) | |
788 | { | |
789 | if (p->path_cost != path_cost) { | |
790 | struct stp *stp = p->stp; | |
791 | p->path_cost = path_cost; | |
792 | stp_configuration_update(stp); | |
793 | stp_port_state_selection(stp); | |
794 | } | |
795 | } | |
796 | ||
797 | /* Sets the path cost of port 'p' based on 'speed' (measured in Mb/s). */ | |
798 | void | |
799 | stp_port_set_speed(struct stp_port *p, unsigned int speed) | |
800 | { | |
3310b570 | 801 | stp_port_set_path_cost(p, stp_convert_speed_to_cost(speed)); |
829a7d02 JP |
802 | } |
803 | ||
804 | /* Enables topology change detection on port 'p'. */ | |
805 | void | |
806 | stp_port_enable_change_detection(struct stp_port *p) | |
807 | { | |
808 | p->change_detection_enabled = true; | |
809 | } | |
810 | ||
811 | /* Disables topology change detection on port 'p'. */ | |
812 | void | |
813 | stp_port_disable_change_detection(struct stp_port *p) | |
814 | { | |
815 | p->change_detection_enabled = false; | |
816 | } | |
817 | \f | |
818 | static void | |
819 | stp_transmit_config(struct stp_port *p) | |
820 | { | |
821 | struct stp *stp = p->stp; | |
822 | bool root = stp_is_root_bridge(stp); | |
823 | if (!root && !stp->root_port) { | |
824 | return; | |
825 | } | |
826 | if (p->hold_timer.active) { | |
827 | p->config_pending = true; | |
828 | } else { | |
829 | struct stp_config_bpdu config; | |
830 | memset(&config, 0, sizeof config); | |
831 | config.header.protocol_id = htons(STP_PROTOCOL_ID); | |
832 | config.header.protocol_version = STP_PROTOCOL_VERSION; | |
833 | config.header.bpdu_type = STP_TYPE_CONFIG; | |
834 | config.flags = 0; | |
835 | if (p->topology_change_ack) { | |
3310b570 | 836 | config.flags |= STP_CONFIG_TOPOLOGY_CHANGE_ACK; |
829a7d02 JP |
837 | } |
838 | if (stp->topology_change) { | |
3310b570 | 839 | config.flags |= STP_CONFIG_TOPOLOGY_CHANGE; |
829a7d02 JP |
840 | } |
841 | config.root_id = htonll(stp->designated_root); | |
842 | config.root_path_cost = htonl(stp->root_path_cost); | |
843 | config.bridge_id = htonll(stp->bridge_id); | |
844 | config.port_id = htons(p->port_id); | |
845 | if (root) { | |
846 | config.message_age = htons(0); | |
847 | } else { | |
848 | config.message_age = htons(stp->root_port->message_age_timer.value | |
849 | + MESSAGE_AGE_INCREMENT); | |
850 | } | |
851 | config.max_age = htons(stp->max_age); | |
852 | config.hello_time = htons(stp->hello_time); | |
853 | config.forward_delay = htons(stp->forward_delay); | |
854 | if (ntohs(config.message_age) < stp->max_age) { | |
855 | p->topology_change_ack = false; | |
856 | p->config_pending = false; | |
857 | stp_send_bpdu(p, &config, sizeof config); | |
858 | stp_start_timer(&p->hold_timer, 0); | |
859 | } | |
860 | } | |
861 | } | |
862 | ||
863 | static bool | |
864 | stp_supersedes_port_info(const struct stp_port *p, | |
865 | const struct stp_config_bpdu *config) | |
866 | { | |
867 | if (ntohll(config->root_id) != p->designated_root) { | |
868 | return ntohll(config->root_id) < p->designated_root; | |
869 | } else if (ntohl(config->root_path_cost) != p->designated_cost) { | |
870 | return ntohl(config->root_path_cost) < p->designated_cost; | |
871 | } else if (ntohll(config->bridge_id) != p->designated_bridge) { | |
872 | return ntohll(config->bridge_id) < p->designated_bridge; | |
873 | } else { | |
874 | return (ntohll(config->bridge_id) != p->stp->bridge_id | |
875 | || ntohs(config->port_id) <= p->designated_port); | |
876 | } | |
877 | } | |
878 | ||
879 | static void | |
880 | stp_record_config_information(struct stp_port *p, | |
881 | const struct stp_config_bpdu *config) | |
882 | { | |
883 | p->designated_root = ntohll(config->root_id); | |
884 | p->designated_cost = ntohl(config->root_path_cost); | |
885 | p->designated_bridge = ntohll(config->bridge_id); | |
886 | p->designated_port = ntohs(config->port_id); | |
887 | stp_start_timer(&p->message_age_timer, ntohs(config->message_age)); | |
888 | } | |
889 | ||
890 | static void | |
891 | stp_record_config_timeout_values(struct stp *stp, | |
892 | const struct stp_config_bpdu *config) | |
893 | { | |
894 | stp->max_age = ntohs(config->max_age); | |
895 | stp->hello_time = ntohs(config->hello_time); | |
896 | stp->forward_delay = ntohs(config->forward_delay); | |
3310b570 | 897 | stp->topology_change = config->flags & STP_CONFIG_TOPOLOGY_CHANGE; |
829a7d02 JP |
898 | } |
899 | ||
900 | static bool | |
901 | stp_is_designated_port(const struct stp_port *p) | |
902 | { | |
903 | return (p->designated_bridge == p->stp->bridge_id | |
904 | && p->designated_port == p->port_id); | |
905 | } | |
906 | ||
907 | static void | |
908 | stp_config_bpdu_generation(struct stp *stp) | |
909 | { | |
910 | struct stp_port *p; | |
911 | ||
912 | FOR_EACH_ENABLED_PORT (p, stp) { | |
913 | if (stp_is_designated_port(p)) { | |
914 | stp_transmit_config(p); | |
915 | } | |
916 | } | |
917 | } | |
918 | ||
919 | static void | |
920 | stp_transmit_tcn(struct stp *stp) | |
921 | { | |
922 | struct stp_port *p = stp->root_port; | |
923 | struct stp_tcn_bpdu tcn_bpdu; | |
924 | if (!p) { | |
925 | return; | |
926 | } | |
927 | tcn_bpdu.header.protocol_id = htons(STP_PROTOCOL_ID); | |
928 | tcn_bpdu.header.protocol_version = STP_PROTOCOL_VERSION; | |
929 | tcn_bpdu.header.bpdu_type = STP_TYPE_TCN; | |
930 | stp_send_bpdu(p, &tcn_bpdu, sizeof tcn_bpdu); | |
931 | } | |
932 | ||
933 | static void | |
934 | stp_configuration_update(struct stp *stp) | |
935 | { | |
936 | stp_root_selection(stp); | |
937 | stp_designated_port_selection(stp); | |
938 | } | |
939 | ||
940 | static bool | |
941 | stp_supersedes_root(const struct stp_port *root, const struct stp_port *p) | |
942 | { | |
943 | int p_cost = p->designated_cost + p->path_cost; | |
944 | int root_cost = root->designated_cost + root->path_cost; | |
945 | ||
946 | if (p->designated_root != root->designated_root) { | |
947 | return p->designated_root < root->designated_root; | |
948 | } else if (p_cost != root_cost) { | |
949 | return p_cost < root_cost; | |
950 | } else if (p->designated_bridge != root->designated_bridge) { | |
951 | return p->designated_bridge < root->designated_bridge; | |
952 | } else if (p->designated_port != root->designated_port) { | |
953 | return p->designated_port < root->designated_port; | |
954 | } else { | |
955 | return p->port_id < root->port_id; | |
956 | } | |
957 | } | |
958 | ||
959 | static void | |
960 | stp_root_selection(struct stp *stp) | |
961 | { | |
962 | struct stp_port *p, *root; | |
963 | ||
964 | root = NULL; | |
965 | FOR_EACH_ENABLED_PORT (p, stp) { | |
966 | if (stp_is_designated_port(p) | |
967 | || p->designated_root >= stp->bridge_id) { | |
968 | continue; | |
969 | } | |
970 | if (root && !stp_supersedes_root(root, p)) { | |
971 | continue; | |
972 | } | |
973 | root = p; | |
974 | } | |
975 | stp->root_port = root; | |
976 | if (!root) { | |
977 | stp->designated_root = stp->bridge_id; | |
978 | stp->root_path_cost = 0; | |
979 | } else { | |
980 | stp->designated_root = root->designated_root; | |
981 | stp->root_path_cost = root->designated_cost + root->path_cost; | |
982 | } | |
983 | } | |
984 | ||
985 | static void | |
986 | stp_designated_port_selection(struct stp *stp) | |
987 | { | |
988 | struct stp_port *p; | |
989 | ||
990 | FOR_EACH_ENABLED_PORT (p, stp) { | |
991 | if (stp_is_designated_port(p) | |
992 | || p->designated_root != stp->designated_root | |
993 | || stp->root_path_cost < p->designated_cost | |
994 | || (stp->root_path_cost == p->designated_cost | |
995 | && (stp->bridge_id < p->designated_bridge | |
996 | || (stp->bridge_id == p->designated_bridge | |
997 | && p->port_id <= p->designated_port)))) | |
998 | { | |
999 | stp_become_designated_port(p); | |
1000 | } | |
1001 | } | |
1002 | } | |
1003 | ||
1004 | static void | |
1005 | stp_become_designated_port(struct stp_port *p) | |
1006 | { | |
1007 | struct stp *stp = p->stp; | |
1008 | p->designated_root = stp->designated_root; | |
1009 | p->designated_cost = stp->root_path_cost; | |
1010 | p->designated_bridge = stp->bridge_id; | |
1011 | p->designated_port = p->port_id; | |
1012 | } | |
1013 | ||
1014 | static void | |
1015 | stp_port_state_selection(struct stp *stp) | |
1016 | { | |
1017 | struct stp_port *p; | |
1018 | ||
1019 | FOR_EACH_ENABLED_PORT (p, stp) { | |
1020 | if (p == stp->root_port) { | |
1021 | p->config_pending = false; | |
1022 | p->topology_change_ack = false; | |
1023 | stp_make_forwarding(p); | |
1024 | } else if (stp_is_designated_port(p)) { | |
1025 | stp_stop_timer(&p->message_age_timer); | |
1026 | stp_make_forwarding(p); | |
1027 | } else { | |
1028 | p->config_pending = false; | |
1029 | p->topology_change_ack = false; | |
1030 | stp_make_blocking(p); | |
1031 | } | |
1032 | } | |
1033 | } | |
1034 | ||
1035 | static void | |
1036 | stp_make_forwarding(struct stp_port *p) | |
1037 | { | |
1038 | if (p->state == STP_BLOCKING) { | |
1039 | stp_set_port_state(p, STP_LISTENING); | |
1040 | stp_start_timer(&p->forward_delay_timer, 0); | |
1041 | } | |
1042 | } | |
1043 | ||
1044 | static void | |
1045 | stp_make_blocking(struct stp_port *p) | |
1046 | { | |
1047 | if (!(p->state & (STP_DISABLED | STP_BLOCKING))) { | |
1048 | if (p->state & (STP_FORWARDING | STP_LEARNING)) { | |
1049 | if (p->change_detection_enabled) { | |
1050 | stp_topology_change_detection(p->stp); | |
1051 | } | |
1052 | } | |
1053 | stp_set_port_state(p, STP_BLOCKING); | |
1054 | stp_stop_timer(&p->forward_delay_timer); | |
1055 | } | |
1056 | } | |
1057 | ||
1058 | static void | |
1059 | stp_set_port_state(struct stp_port *p, enum stp_state state) | |
1060 | { | |
1061 | if (state != p->state && !p->state_changed) { | |
1062 | p->state_changed = true; | |
1063 | if (p < p->stp->first_changed_port) { | |
1064 | p->stp->first_changed_port = p; | |
1065 | } | |
1066 | } | |
1067 | p->state = state; | |
1068 | } | |
1069 | ||
1070 | static void | |
1071 | stp_topology_change_detection(struct stp *stp) | |
1072 | { | |
634408e0 EJ |
1073 | static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5); |
1074 | ||
829a7d02 JP |
1075 | if (stp_is_root_bridge(stp)) { |
1076 | stp->topology_change = true; | |
1077 | stp_start_timer(&stp->topology_change_timer, 0); | |
1078 | } else if (!stp->topology_change_detected) { | |
1079 | stp_transmit_tcn(stp); | |
1080 | stp_start_timer(&stp->tcn_timer, 0); | |
1081 | } | |
6ae50723 | 1082 | stp->fdb_needs_flush = true; |
829a7d02 | 1083 | stp->topology_change_detected = true; |
634408e0 | 1084 | VLOG_INFO_RL(&rl, "%s: detected topology change.", stp->name); |
829a7d02 JP |
1085 | } |
1086 | ||
1087 | static void | |
1088 | stp_topology_change_acknowledged(struct stp *stp) | |
1089 | { | |
1090 | stp->topology_change_detected = false; | |
1091 | stp_stop_timer(&stp->tcn_timer); | |
1092 | } | |
1093 | ||
1094 | static void | |
1095 | stp_acknowledge_topology_change(struct stp_port *p) | |
1096 | { | |
1097 | p->topology_change_ack = true; | |
1098 | stp_transmit_config(p); | |
1099 | } | |
1100 | ||
1101 | static void | |
1102 | stp_received_config_bpdu(struct stp *stp, struct stp_port *p, | |
1103 | const struct stp_config_bpdu *config) | |
1104 | { | |
1105 | if (ntohs(config->message_age) >= ntohs(config->max_age)) { | |
1106 | VLOG_WARN("%s: received config BPDU with message age (%u) greater " | |
1107 | "than max age (%u)", | |
1108 | stp->name, | |
1109 | ntohs(config->message_age), ntohs(config->max_age)); | |
1110 | return; | |
1111 | } | |
1112 | if (p->state != STP_DISABLED) { | |
1113 | bool root = stp_is_root_bridge(stp); | |
1114 | if (stp_supersedes_port_info(p, config)) { | |
1115 | stp_record_config_information(p, config); | |
1116 | stp_configuration_update(stp); | |
1117 | stp_port_state_selection(stp); | |
1118 | if (!stp_is_root_bridge(stp) && root) { | |
1119 | stp_stop_timer(&stp->hello_timer); | |
1120 | if (stp->topology_change_detected) { | |
1121 | stp_stop_timer(&stp->topology_change_timer); | |
1122 | stp_transmit_tcn(stp); | |
1123 | stp_start_timer(&stp->tcn_timer, 0); | |
1124 | } | |
1125 | } | |
1126 | if (p == stp->root_port) { | |
1127 | stp_record_config_timeout_values(stp, config); | |
1128 | stp_config_bpdu_generation(stp); | |
3310b570 | 1129 | if (config->flags & STP_CONFIG_TOPOLOGY_CHANGE_ACK) { |
829a7d02 JP |
1130 | stp_topology_change_acknowledged(stp); |
1131 | } | |
6ae50723 EJ |
1132 | if (config->flags & STP_CONFIG_TOPOLOGY_CHANGE) { |
1133 | stp->fdb_needs_flush = true; | |
1134 | } | |
829a7d02 JP |
1135 | } |
1136 | } else if (stp_is_designated_port(p)) { | |
1137 | stp_transmit_config(p); | |
1138 | } | |
1139 | } | |
1140 | } | |
1141 | ||
1142 | static void | |
1143 | stp_received_tcn_bpdu(struct stp *stp, struct stp_port *p) | |
1144 | { | |
1145 | if (p->state != STP_DISABLED) { | |
1146 | if (stp_is_designated_port(p)) { | |
1147 | stp_topology_change_detection(stp); | |
1148 | stp_acknowledge_topology_change(p); | |
1149 | } | |
1150 | } | |
1151 | } | |
1152 | ||
1153 | static void | |
1154 | stp_hello_timer_expiry(struct stp *stp) | |
1155 | { | |
1156 | stp_config_bpdu_generation(stp); | |
1157 | stp_start_timer(&stp->hello_timer, 0); | |
1158 | } | |
1159 | ||
1160 | static void | |
1161 | stp_message_age_timer_expiry(struct stp_port *p) | |
1162 | { | |
1163 | struct stp *stp = p->stp; | |
1164 | bool root = stp_is_root_bridge(stp); | |
1165 | stp_become_designated_port(p); | |
1166 | stp_configuration_update(stp); | |
1167 | stp_port_state_selection(stp); | |
1168 | if (stp_is_root_bridge(stp) && !root) { | |
1169 | stp->max_age = stp->bridge_max_age; | |
1170 | stp->hello_time = stp->bridge_hello_time; | |
1171 | stp->forward_delay = stp->bridge_forward_delay; | |
1172 | stp_topology_change_detection(stp); | |
1173 | stp_stop_timer(&stp->tcn_timer); | |
1174 | stp_config_bpdu_generation(stp); | |
1175 | stp_start_timer(&stp->hello_timer, 0); | |
1176 | } | |
1177 | } | |
1178 | ||
1179 | static bool | |
1180 | stp_is_designated_for_some_port(const struct stp *stp) | |
1181 | { | |
1182 | const struct stp_port *p; | |
1183 | ||
1184 | FOR_EACH_ENABLED_PORT (p, stp) { | |
1185 | if (p->designated_bridge == stp->bridge_id) { | |
1186 | return true; | |
1187 | } | |
1188 | } | |
1189 | return false; | |
1190 | } | |
1191 | ||
1192 | static void | |
1193 | stp_forward_delay_timer_expiry(struct stp_port *p) | |
1194 | { | |
1195 | if (p->state == STP_LISTENING) { | |
1196 | stp_set_port_state(p, STP_LEARNING); | |
1197 | stp_start_timer(&p->forward_delay_timer, 0); | |
1198 | } else if (p->state == STP_LEARNING) { | |
1199 | stp_set_port_state(p, STP_FORWARDING); | |
1200 | if (stp_is_designated_for_some_port(p->stp)) { | |
1201 | if (p->change_detection_enabled) { | |
1202 | stp_topology_change_detection(p->stp); | |
1203 | } | |
1204 | } | |
1205 | } | |
1206 | } | |
1207 | ||
1208 | static void | |
1209 | stp_tcn_timer_expiry(struct stp *stp) | |
1210 | { | |
1211 | stp_transmit_tcn(stp); | |
1212 | stp_start_timer(&stp->tcn_timer, 0); | |
1213 | } | |
1214 | ||
1215 | static void | |
1216 | stp_topology_change_timer_expiry(struct stp *stp) | |
1217 | { | |
1218 | stp->topology_change_detected = false; | |
1219 | stp->topology_change = false; | |
1220 | } | |
1221 | ||
1222 | static void | |
1223 | stp_hold_timer_expiry(struct stp_port *p) | |
1224 | { | |
1225 | if (p->config_pending) { | |
1226 | stp_transmit_config(p); | |
1227 | } | |
1228 | } | |
1229 | ||
1230 | static void | |
1231 | stp_initialize_port(struct stp_port *p, enum stp_state state) | |
1232 | { | |
cb22974d | 1233 | ovs_assert(state & (STP_DISABLED | STP_BLOCKING)); |
829a7d02 JP |
1234 | stp_become_designated_port(p); |
1235 | stp_set_port_state(p, state); | |
1236 | p->topology_change_ack = false; | |
1237 | p->config_pending = false; | |
1238 | p->change_detection_enabled = true; | |
3310b570 | 1239 | p->aux = NULL; |
829a7d02 JP |
1240 | stp_stop_timer(&p->message_age_timer); |
1241 | stp_stop_timer(&p->forward_delay_timer); | |
1242 | stp_stop_timer(&p->hold_timer); | |
80740385 | 1243 | p->tx_count = p->rx_count = p->error_count = 0; |
829a7d02 JP |
1244 | } |
1245 | ||
1246 | static void | |
1247 | stp_become_root_bridge(struct stp *stp) | |
1248 | { | |
1249 | stp->max_age = stp->bridge_max_age; | |
1250 | stp->hello_time = stp->bridge_hello_time; | |
1251 | stp->forward_delay = stp->bridge_forward_delay; | |
1252 | stp_topology_change_detection(stp); | |
1253 | stp_stop_timer(&stp->tcn_timer); | |
1254 | stp_config_bpdu_generation(stp); | |
1255 | stp_start_timer(&stp->hello_timer, 0); | |
1256 | } | |
1257 | ||
1258 | static void | |
1259 | stp_start_timer(struct stp_timer *timer, int value) | |
1260 | { | |
1261 | timer->value = value; | |
1262 | timer->active = true; | |
1263 | } | |
1264 | ||
1265 | static void | |
1266 | stp_stop_timer(struct stp_timer *timer) | |
1267 | { | |
1268 | timer->active = false; | |
1269 | } | |
1270 | ||
1271 | static bool | |
1272 | stp_timer_expired(struct stp_timer *timer, int elapsed, int timeout) | |
1273 | { | |
1274 | if (timer->active) { | |
1275 | timer->value += elapsed; | |
1276 | if (timer->value >= timeout) { | |
1277 | timer->active = false; | |
1278 | return true; | |
1279 | } | |
1280 | } | |
1281 | return false; | |
1282 | } | |
1283 | ||
1284 | /* Returns the number of whole STP timer ticks in 'ms' milliseconds. There | |
1285 | * are 256 STP timer ticks per second. */ | |
1286 | static int | |
1287 | ms_to_timer(int ms) | |
1288 | { | |
1289 | return ms * 0x100 / 1000; | |
1290 | } | |
1291 | ||
829a7d02 JP |
1292 | /* Returns the number of whole milliseconds in 'timer' STP timer ticks. There |
1293 | * are 256 STP timer ticks per second. */ | |
1294 | static int | |
1295 | timer_to_ms(int timer) | |
1296 | { | |
1297 | return timer * 1000 / 0x100; | |
1298 | } | |
1299 | ||
1300 | static int | |
1301 | clamp(int x, int min, int max) | |
1302 | { | |
1303 | return x < min ? min : x > max ? max : x; | |
1304 | } | |
1305 | ||
1306 | static void | |
1307 | stp_update_bridge_timers(struct stp *stp) | |
1308 | { | |
1309 | int ht, ma, fd; | |
1310 | ||
1311 | ht = clamp(stp->rq_hello_time, 1000, 10000); | |
1312 | ma = clamp(stp->rq_max_age, MAX(2 * (ht + 1000), 6000), 40000); | |
1313 | fd = clamp(stp->rq_forward_delay, ma / 2 + 1000, 30000); | |
1314 | ||
1315 | stp->bridge_hello_time = ms_to_timer(ht); | |
1316 | stp->bridge_max_age = ms_to_timer(ma); | |
1317 | stp->bridge_forward_delay = ms_to_timer(fd); | |
1318 | ||
1319 | if (stp_is_root_bridge(stp)) { | |
1320 | stp->max_age = stp->bridge_max_age; | |
1321 | stp->hello_time = stp->bridge_hello_time; | |
1322 | stp->forward_delay = stp->bridge_forward_delay; | |
1323 | } | |
1324 | } | |
1325 | ||
1326 | static void | |
1327 | stp_send_bpdu(struct stp_port *p, const void *bpdu, size_t bpdu_size) | |
1328 | { | |
1329 | struct eth_header *eth; | |
1330 | struct llc_header *llc; | |
1331 | struct ofpbuf *pkt; | |
1332 | ||
1333 | /* Skeleton. */ | |
1334 | pkt = ofpbuf_new(ETH_HEADER_LEN + LLC_HEADER_LEN + bpdu_size); | |
1335 | pkt->l2 = eth = ofpbuf_put_zeros(pkt, sizeof *eth); | |
1336 | llc = ofpbuf_put_zeros(pkt, sizeof *llc); | |
1337 | pkt->l3 = ofpbuf_put(pkt, bpdu, bpdu_size); | |
1338 | ||
1339 | /* 802.2 header. */ | |
1340 | memcpy(eth->eth_dst, eth_addr_stp, ETH_ADDR_LEN); | |
1341 | /* p->stp->send_bpdu() must fill in source address. */ | |
1342 | eth->eth_type = htons(pkt->size - ETH_HEADER_LEN); | |
1343 | ||
1344 | /* LLC header. */ | |
1345 | llc->llc_dsap = STP_LLC_DSAP; | |
1346 | llc->llc_ssap = STP_LLC_SSAP; | |
1347 | llc->llc_cntl = STP_LLC_CNTL; | |
1348 | ||
1349 | p->stp->send_bpdu(pkt, stp_port_no(p), p->stp->aux); | |
80740385 | 1350 | p->tx_count++; |
829a7d02 | 1351 | } |
fe4a02e4 EJ |
1352 | \f |
1353 | /* Unixctl. */ | |
1354 | ||
1355 | static struct stp * | |
1356 | stp_find(const char *name) | |
1357 | { | |
1358 | struct stp *stp; | |
1359 | ||
1360 | LIST_FOR_EACH (stp, node, &all_stps) { | |
1361 | if (!strcmp(stp->name, name)) { | |
1362 | return stp; | |
1363 | } | |
1364 | } | |
1365 | return NULL; | |
1366 | } | |
1367 | ||
1368 | static void | |
1369 | stp_unixctl_tcn(struct unixctl_conn *conn, int argc, | |
1370 | const char *argv[], void *aux OVS_UNUSED) | |
1371 | { | |
1372 | if (argc > 1) { | |
1373 | struct stp *stp = stp_find(argv[1]); | |
1374 | ||
1375 | if (!stp) { | |
bde9f75d | 1376 | unixctl_command_reply_error(conn, "no such stp object"); |
fe4a02e4 EJ |
1377 | return; |
1378 | } | |
1379 | stp_topology_change_detection(stp); | |
1380 | } else { | |
1381 | struct stp *stp; | |
1382 | ||
1383 | LIST_FOR_EACH (stp, node, &all_stps) { | |
1384 | stp_topology_change_detection(stp); | |
1385 | } | |
1386 | } | |
1387 | ||
bde9f75d | 1388 | unixctl_command_reply(conn, "OK"); |
fe4a02e4 | 1389 | } |