2 * Copyright (c) 2008, 2009, 2010 Nicira Networks.
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:
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
18 #include "learning-switch.h"
22 #include <netinet/in.h>
27 #include "mac-learning.h"
29 #include "ofp-print.h"
31 #include "openflow/openflow.h"
32 #include "poll-loop.h"
40 #define THIS_MODULE VLM_learning_switch
47 P_FORWARDING = 1 << 3,
52 /* If nonnegative, the switch sets up flows that expire after the given
53 * number of seconds (or never expire, if the value is OFP_FLOW_PERMANENT).
54 * Otherwise, the switch processes every packet. */
57 unsigned long long int datapath_id;
58 uint32_t capabilities;
59 time_t last_features_request;
60 struct mac_learning *ml; /* NULL to act as hub instead of switch. */
61 uint32_t wildcards; /* Wildcards to apply to flows. */
62 bool action_normal; /* Use OFPP_NORMAL? */
64 /* Number of outgoing queued packets on the rconn. */
65 struct rconn_packet_counter *queued;
67 /* Spanning tree protocol implementation.
69 * We implement STP states by, whenever a port's STP state changes,
70 * querying all the flows on the switch and then deleting any of them that
71 * are inappropriate for a port's STP state. */
72 long long int next_query; /* Next time at which to query all flows. */
73 long long int last_query; /* Last time we sent a query. */
74 long long int last_reply; /* Last time we received a query reply. */
75 unsigned int port_states[STP_MAX_PORTS];
76 uint32_t query_xid; /* XID used for query. */
77 int n_flows, n_no_recv, n_no_send;
80 /* The log messages here could actually be useful in debugging, so keep the
81 * rate limit relatively high. */
82 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(30, 300);
84 static void queue_tx(struct lswitch *, struct rconn *, struct ofpbuf *);
85 static void send_features_request(struct lswitch *, struct rconn *);
86 static void schedule_query(struct lswitch *, long long int delay);
87 static bool may_learn(const struct lswitch *, uint16_t port_no);
88 static bool may_recv(const struct lswitch *, uint16_t port_no,
90 static bool may_send(const struct lswitch *, uint16_t port_no);
92 typedef void packet_handler_func(struct lswitch *, struct rconn *, void *);
93 static packet_handler_func process_switch_features;
94 static packet_handler_func process_packet_in;
95 static packet_handler_func process_echo_request;
96 static packet_handler_func process_port_status;
97 static packet_handler_func process_phy_port;
98 static packet_handler_func process_stats_reply;
100 /* Creates and returns a new learning switch.
102 * If 'learn_macs' is true, the new switch will learn the ports on which MAC
103 * addresses appear. Otherwise, the new switch will flood all packets.
105 * If 'max_idle' is nonnegative, the new switch will set up flows that expire
106 * after the given number of seconds (or never expire, if 'max_idle' is
107 * OFP_FLOW_PERMANENT). Otherwise, the new switch will process every packet.
109 * 'rconn' is used to send out an OpenFlow features request. */
111 lswitch_create(struct rconn *rconn, bool learn_macs,
112 bool exact_flows, int max_idle, bool action_normal)
117 sw = xzalloc(sizeof *sw);
118 sw->max_idle = max_idle;
120 sw->last_features_request = time_now() - 1;
121 sw->ml = learn_macs ? mac_learning_create() : NULL;
122 sw->action_normal = action_normal;
127 /* We cannot wildcard all fields.
128 * We need in_port to detect moves.
129 * We need both SA and DA to do learning. */
130 sw->wildcards = (OFPFW_DL_TYPE | OFPFW_NW_SRC_MASK | OFPFW_NW_DST_MASK
131 | OFPFW_NW_PROTO | OFPFW_TP_SRC | OFPFW_TP_DST);
133 sw->queued = rconn_packet_counter_create();
134 sw->next_query = LLONG_MIN;
135 sw->last_query = LLONG_MIN;
136 sw->last_reply = LLONG_MIN;
137 for (i = 0; i < STP_MAX_PORTS; i++) {
138 sw->port_states[i] = P_DISABLED;
140 send_features_request(sw, rconn);
146 lswitch_destroy(struct lswitch *sw)
149 mac_learning_destroy(sw->ml);
150 rconn_packet_counter_destroy(sw->queued);
155 /* Takes care of necessary 'sw' activity, except for receiving packets (which
156 * the caller must do). */
158 lswitch_run(struct lswitch *sw, struct rconn *rconn)
160 long long int now = time_msec();
163 mac_learning_run(sw->ml, NULL);
166 /* If we're waiting for more replies, keeping waiting for up to 10 s. */
167 if (sw->last_reply != LLONG_MIN) {
168 if (now - sw->last_reply > 10000) {
169 VLOG_ERR_RL(&rl, "%016llx: No more flow stat replies last 10 s",
171 sw->last_reply = LLONG_MIN;
172 sw->last_query = LLONG_MIN;
173 schedule_query(sw, 0);
179 /* If we're waiting for any reply at all, keep waiting for up to 10 s. */
180 if (sw->last_query != LLONG_MIN) {
181 if (now - sw->last_query > 10000) {
182 VLOG_ERR_RL(&rl, "%016llx: No flow stat replies in last 10 s",
184 sw->last_query = LLONG_MIN;
185 schedule_query(sw, 0);
191 /* If it's time to send another query, do so. */
192 if (sw->next_query != LLONG_MIN && now >= sw->next_query) {
193 sw->next_query = LLONG_MIN;
194 if (!rconn_is_connected(rconn)) {
195 schedule_query(sw, 1000);
197 struct ofp_stats_request *osr;
198 struct ofp_flow_stats_request *ofsr;
202 VLOG_DBG("%016llx: Sending flow stats request to implement STP",
205 sw->last_query = now;
206 sw->query_xid = random_uint32();
210 osr = make_openflow_xid(sizeof *osr + sizeof *ofsr,
211 OFPT_STATS_REQUEST, sw->query_xid, &b);
212 osr->type = htons(OFPST_FLOW);
213 osr->flags = htons(0);
214 ofsr = (struct ofp_flow_stats_request *) osr->body;
215 ofsr->match.wildcards = htonl(OFPFW_ALL);
216 ofsr->table_id = 0xff;
217 ofsr->out_port = htons(OFPP_NONE);
219 error = rconn_send(rconn, b, NULL);
221 VLOG_WARN_RL(&rl, "%016llx: sending flow stats request "
222 "failed: %s", sw->datapath_id, strerror(error));
224 schedule_query(sw, 1000);
231 wait_timeout(long long int started)
233 poll_timer_wait_until(started + 10000);
237 lswitch_wait(struct lswitch *sw)
240 mac_learning_wait(sw->ml);
243 if (sw->last_reply != LLONG_MIN) {
244 wait_timeout(sw->last_reply);
245 } else if (sw->last_query != LLONG_MIN) {
246 wait_timeout(sw->last_query);
250 /* Processes 'msg', which should be an OpenFlow received on 'rconn', according
251 * to the learning switch state in 'sw'. The most likely result of processing
252 * is that flow-setup and packet-out OpenFlow messages will be sent out on
255 lswitch_process_packet(struct lswitch *sw, struct rconn *rconn,
256 const struct ofpbuf *msg)
261 packet_handler_func *handler;
263 static const struct processor processors[] = {
266 sizeof(struct ofp_header),
271 sizeof(struct ofp_switch_features),
272 process_switch_features
276 offsetof(struct ofp_packet_in, data),
281 sizeof(struct ofp_port_status),
286 offsetof(struct ofp_stats_reply, body),
291 sizeof(struct ofp_flow_removed),
295 const size_t n_processors = ARRAY_SIZE(processors);
296 const struct processor *p;
297 struct ofp_header *oh;
300 if (sw->datapath_id == 0
301 && oh->type != OFPT_ECHO_REQUEST
302 && oh->type != OFPT_FEATURES_REPLY) {
303 send_features_request(sw, rconn);
307 for (p = processors; p < &processors[n_processors]; p++) {
308 if (oh->type == p->type) {
309 if (msg->size < p->min_size) {
310 VLOG_WARN_RL(&rl, "%016llx: %s: too short (%zu bytes) for "
311 "type %"PRIu8" (min %zu)", sw->datapath_id,
312 rconn_get_name(rconn), msg->size, oh->type,
317 (p->handler)(sw, rconn, msg->data);
322 if (VLOG_IS_DBG_ENABLED()) {
323 char *p = ofp_to_string(msg->data, msg->size, 2);
324 VLOG_DBG_RL(&rl, "%016llx: OpenFlow packet ignored: %s",
331 send_features_request(struct lswitch *sw, struct rconn *rconn)
333 time_t now = time_now();
334 if (now >= sw->last_features_request + 1) {
336 struct ofp_switch_config *osc;
338 /* Send OFPT_FEATURES_REQUEST. */
339 make_openflow(sizeof(struct ofp_header), OFPT_FEATURES_REQUEST, &b);
340 queue_tx(sw, rconn, b);
342 /* Send OFPT_SET_CONFIG. */
343 osc = make_openflow(sizeof *osc, OFPT_SET_CONFIG, &b);
344 osc->miss_send_len = htons(OFP_DEFAULT_MISS_SEND_LEN);
345 queue_tx(sw, rconn, b);
347 sw->last_features_request = now;
352 queue_tx(struct lswitch *sw, struct rconn *rconn, struct ofpbuf *b)
354 int retval = rconn_send_with_limit(rconn, b, sw->queued, 10);
355 if (retval && retval != ENOTCONN) {
356 if (retval == EAGAIN) {
357 VLOG_INFO_RL(&rl, "%016llx: %s: tx queue overflow",
358 sw->datapath_id, rconn_get_name(rconn));
360 VLOG_WARN_RL(&rl, "%016llx: %s: send: %s",
361 sw->datapath_id, rconn_get_name(rconn),
368 schedule_query(struct lswitch *sw, long long int delay)
370 long long int now = time_msec();
371 if (sw->next_query == LLONG_MIN || sw->next_query > now + delay) {
372 sw->next_query = now + delay;
377 process_switch_features(struct lswitch *sw, struct rconn *rconn, void *osf_)
379 struct ofp_switch_features *osf = osf_;
380 size_t n_ports = ((ntohs(osf->header.length)
381 - offsetof(struct ofp_switch_features, ports))
382 / sizeof *osf->ports);
385 sw->datapath_id = ntohll(osf->datapath_id);
386 sw->capabilities = ntohl(osf->capabilities);
387 for (i = 0; i < n_ports; i++) {
388 process_phy_port(sw, rconn, &osf->ports[i]);
390 if (sw->capabilities & OFPC_STP) {
391 schedule_query(sw, 1000);
396 lswitch_choose_destination(struct lswitch *sw, const flow_t *flow)
400 /* Learn the source MAC. */
401 if (may_learn(sw, flow->in_port) && sw->ml) {
402 if (mac_learning_learn(sw->ml, flow->dl_src, 0, flow->in_port,
403 GRAT_ARP_LOCK_NONE)) {
404 VLOG_DBG_RL(&rl, "%016llx: learned that "ETH_ADDR_FMT" is on "
405 "port %"PRIu16, sw->datapath_id,
406 ETH_ADDR_ARGS(flow->dl_src), flow->in_port);
410 /* Drop frames for reserved multicast addresses. */
411 if (eth_addr_is_reserved(flow->dl_dst)) {
415 if (!may_recv(sw, flow->in_port, false)) {
416 /* STP prevents receiving anything on this port. */
420 out_port = OFPP_FLOOD;
422 int learned_port = mac_learning_lookup(sw->ml, flow->dl_dst, 0, NULL);
423 if (learned_port >= 0 && may_send(sw, learned_port)) {
424 out_port = learned_port;
425 if (out_port == flow->in_port) {
426 /* Don't send a packet back out its input port. */
432 /* Check if we need to use "NORMAL" action. */
433 if (sw->action_normal && out_port != OFPP_FLOOD) {
441 process_packet_in(struct lswitch *sw, struct rconn *rconn, void *opi_)
443 struct ofp_packet_in *opi = opi_;
444 uint16_t in_port = ntohs(opi->in_port);
447 size_t pkt_ofs, pkt_len;
451 /* Extract flow data from 'opi' into 'flow'. */
452 pkt_ofs = offsetof(struct ofp_packet_in, data);
453 pkt_len = ntohs(opi->header.length) - pkt_ofs;
454 pkt.data = opi->data;
456 flow_extract(&pkt, 0, in_port, &flow);
458 /* Choose output port. */
459 out_port = lswitch_choose_destination(sw, &flow);
461 /* Send the packet, and possibly the whole flow, to the output port. */
462 if (sw->max_idle >= 0 && (!sw->ml || out_port != OFPP_FLOOD)) {
463 struct ofpbuf *buffer;
464 struct ofp_flow_mod *ofm;
466 /* The output port is known, or we always flood everything, so add a
468 buffer = make_add_simple_flow(&flow, ntohl(opi->buffer_id),
469 out_port, sw->max_idle);
471 ofm->match.wildcards = htonl(sw->wildcards);
472 queue_tx(sw, rconn, buffer);
474 /* If the switch didn't buffer the packet, we need to send a copy. */
475 if (ntohl(opi->buffer_id) == UINT32_MAX && out_port != OFPP_NONE) {
477 make_unbuffered_packet_out(&pkt, in_port, out_port));
480 /* We don't know that MAC, or we don't set up flows. Send along the
481 * packet without setting up a flow. */
482 if (ntohl(opi->buffer_id) == UINT32_MAX) {
483 if (out_port != OFPP_NONE) {
485 make_unbuffered_packet_out(&pkt, in_port, out_port));
489 make_buffered_packet_out(ntohl(opi->buffer_id),
496 process_echo_request(struct lswitch *sw, struct rconn *rconn, void *rq_)
498 struct ofp_header *rq = rq_;
499 queue_tx(sw, rconn, make_echo_reply(rq));
503 process_port_status(struct lswitch *sw, struct rconn *rconn, void *ops_)
505 struct ofp_port_status *ops = ops_;
506 process_phy_port(sw, rconn, &ops->desc);
510 process_phy_port(struct lswitch *sw, struct rconn *rconn OVS_UNUSED,
513 const struct ofp_phy_port *opp = opp_;
514 uint16_t port_no = ntohs(opp->port_no);
515 if (sw->capabilities & OFPC_STP && port_no < STP_MAX_PORTS) {
516 uint32_t config = ntohl(opp->config);
517 uint32_t state = ntohl(opp->state);
518 unsigned int *port_state = &sw->port_states[port_no];
519 unsigned int new_port_state;
521 if (!(config & (OFPPC_NO_STP | OFPPC_PORT_DOWN))
522 && !(state & OFPPS_LINK_DOWN))
524 switch (state & OFPPS_STP_MASK) {
525 case OFPPS_STP_LISTEN:
526 new_port_state = P_LISTENING;
528 case OFPPS_STP_LEARN:
529 new_port_state = P_LEARNING;
531 case OFPPS_STP_FORWARD:
532 new_port_state = P_FORWARDING;
534 case OFPPS_STP_BLOCK:
535 new_port_state = P_BLOCKING;
538 new_port_state = P_DISABLED;
542 new_port_state = P_FORWARDING;
544 if (*port_state != new_port_state) {
545 *port_state = new_port_state;
546 schedule_query(sw, 1000);
552 get_port_state(const struct lswitch *sw, uint16_t port_no)
554 return (port_no >= STP_MAX_PORTS || !(sw->capabilities & OFPC_STP)
556 : sw->port_states[port_no]);
560 may_learn(const struct lswitch *sw, uint16_t port_no)
562 return get_port_state(sw, port_no) & (P_LEARNING | P_FORWARDING);
566 may_recv(const struct lswitch *sw, uint16_t port_no, bool any_actions)
568 unsigned int state = get_port_state(sw, port_no);
570 ? state & (P_DISABLED | P_LISTENING | P_BLOCKING)
571 : state & (P_DISABLED | P_LISTENING | P_BLOCKING | P_LEARNING));
575 may_send(const struct lswitch *sw, uint16_t port_no)
577 return get_port_state(sw, port_no) & P_FORWARDING;
581 process_flow_stats(struct lswitch *sw, struct rconn *rconn,
582 const struct ofp_flow_stats *ofs)
584 const char *end = (char *) ofs + ntohs(ofs->length);
587 /* Decide to delete the flow if it matches on an STP-disabled physical
588 * port. But don't delete it if the flow just drops all received packets,
589 * because that's a perfectly reasonable thing to do for disabled physical
591 if (!(ofs->match.wildcards & htonl(OFPFW_IN_PORT))) {
592 if (!may_recv(sw, ntohs(ofs->match.in_port),
593 end > (char *) ofs->actions)) {
599 /* Decide to delete the flow if it forwards to an STP-disabled physical
602 const struct ofp_action_header *a;
605 for (a = ofs->actions; (char *) a < end; a += len / 8) {
607 if (len > end - (char *) a) {
608 VLOG_DBG_RL(&rl, "%016llx: action exceeds available space "
610 sw->datapath_id, len, end - (char *) a);
612 } else if (len % 8) {
613 VLOG_DBG_RL(&rl, "%016llx: action length (%zu) not multiple "
614 "of 8 bytes", sw->datapath_id, len);
618 if (a->type == htons(OFPAT_OUTPUT)) {
619 struct ofp_action_output *oao = (struct ofp_action_output *) a;
620 if (!may_send(sw, ntohs(oao->port))) {
629 /* Delete the flow. */
631 struct ofp_flow_mod *ofm;
634 ofm = make_openflow(offsetof(struct ofp_flow_mod, actions),
636 ofm->match = ofs->match;
637 ofm->command = OFPFC_DELETE_STRICT;
638 rconn_send(rconn, b, NULL);
643 process_stats_reply(struct lswitch *sw, struct rconn *rconn, void *osr_)
645 struct ofp_stats_reply *osr = osr_;
646 struct flow_stats_iterator i;
647 const struct ofp_flow_stats *fs;
649 if (sw->last_query == LLONG_MIN
650 || osr->type != htons(OFPST_FLOW)
651 || osr->header.xid != sw->query_xid) {
654 for (fs = flow_stats_first(&i, osr); fs; fs = flow_stats_next(&i)) {
656 process_flow_stats(sw, rconn, fs);
658 if (!(osr->flags & htons(OFPSF_REPLY_MORE))) {
659 VLOG_DBG("%016llx: Deleted %d of %d received flows to "
660 "implement STP, %d because of no-recv, %d because of "
661 "no-send", sw->datapath_id,
662 sw->n_no_recv + sw->n_no_send, sw->n_flows,
663 sw->n_no_recv, sw->n_no_send);
664 sw->last_query = LLONG_MIN;
665 sw->last_reply = LLONG_MIN;
667 sw->last_reply = time_msec();