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.
19 #include <arpa/inet.h>
28 #include "mac-learning.h"
31 #include "ofp-print.h"
34 #include "openflow/openflow.h"
35 #include "openvswitch/datapath-protocol.h"
37 #include "poll-loop.h"
43 #define THIS_MODULE VLM_in_band
46 /* In-band control allows a single network to be used for OpenFlow
47 * traffic and other data traffic. Refer to ovs-vswitchd.conf(5) and
48 * secchan(8) for a description of configuring in-band control.
50 * This comment is an attempt to describe how in-band control works at a
51 * wire- and implementation-level. Correctly implementing in-band
52 * control has proven difficult due to its many subtleties, and has thus
53 * gone through many iterations. Please read through and understand the
54 * reasoning behind the chosen rules before making modifications.
56 * In Open vSwitch, in-band control is implemented as "hidden" flows (in
57 * that they are not visible through OpenFlow) and at a higher priority
58 * than wildcarded flows can be set up by the controller. This is done
59 * so that the controller cannot interfere with them and possibly break
60 * connectivity with its switches. It is possible to see all flows,
61 * including in-band ones, with the ovs-appctl "bridge/dump-flows"
64 * The following rules are always enabled with the "normal" action by a
65 * switch with in-band control:
67 * a. DHCP requests sent from the local port.
68 * b. ARP replies to the local port's MAC address.
69 * c. ARP requests from the local port's MAC address.
70 * d. ARP replies to the remote side's MAC address. Note that the
71 * remote side is either the controller or the gateway to reach
73 * e. ARP requests from the remote side's MAC address. Note that
74 * like (d), the MAC is either for the controller or gateway.
75 * f. ARP replies containing the controller's IP address as a target.
76 * g. ARP requests containing the controller's IP address as a source.
77 * h. OpenFlow (6633/tcp) traffic to the controller's IP.
78 * i. OpenFlow (6633/tcp) traffic from the controller's IP.
80 * The goal of these rules is to be as narrow as possible to allow a
81 * switch to join a network and be able to communicate with a
82 * controller. As mentioned earlier, these rules have higher priority
83 * than the controller's rules, so if they are too broad, they may
84 * prevent the controller from implementing its policy. As such,
85 * in-band actively monitors some aspects of flow and packet processing
86 * so that the rules can be made more precise.
88 * In-band control monitors attempts to add flows into the datapath that
89 * could interfere with its duties. The datapath only allows exact
90 * match entries, so in-band control is able to be very precise about
91 * the flows it prevents. Flows that miss in the datapath are sent to
92 * userspace to be processed, so preventing these flows from being
93 * cached in the "fast path" does not affect correctness. The only type
94 * of flow that is currently prevented is one that would prevent DHCP
95 * replies from being seen by the local port. For example, a rule that
96 * forwarded all DHCP traffic to the controller would not be allowed,
97 * but one that forwarded to all ports (including the local port) would.
99 * As mentioned earlier, packets that miss in the datapath are sent to
100 * the userspace for processing. The userspace has its own flow table,
101 * the "classifier", so in-band checks whether any special processing
102 * is needed before the classifier is consulted. If a packet is a DHCP
103 * response to a request from the local port, the packet is forwarded to
104 * the local port, regardless of the flow table. Note that this requires
105 * L7 processing of DHCP replies to determine whether the 'chaddr' field
106 * matches the MAC address of the local port.
108 * It is interesting to note that for an L3-based in-band control
109 * mechanism, the majority of rules are devoted to ARP traffic. At first
110 * glance, some of these rules appear redundant. However, each serves an
111 * important role. First, in order to determine the MAC address of the
112 * remote side (controller or gateway) for other ARP rules, we must allow
113 * ARP traffic for our local port with rules (b) and (c). If we are
114 * between a switch and its connection to the controller, we have to
115 * allow the other switch's ARP traffic to through. This is done with
116 * rules (d) and (e), since we do not know the addresses of the other
117 * switches a priori, but do know the controller's or gateway's. Finally,
118 * if the controller is running in a local guest VM that is not reached
119 * through the local port, the switch that is connected to the VM must
120 * allow ARP traffic based on the controller's IP address, since it will
121 * not know the MAC address of the local port that is sending the traffic
122 * or the MAC address of the controller in the guest VM.
124 * With a few notable exceptions below, in-band should work in most
125 * network setups. The following are considered "supported' in the
126 * current implementation:
128 * - Locally Connected. The switch and controller are on the same
129 * subnet. This uses rules (a), (b), (c), (h), and (i).
131 * - Reached through Gateway. The switch and controller are on
132 * different subnets and must go through a gateway. This uses
133 * rules (a), (b), (c), (h), and (i).
135 * - Between Switch and Controller. This switch is between another
136 * switch and the controller, and we want to allow the other
137 * switch's traffic through. This uses rules (d), (e), (h), and
138 * (i). It uses (b) and (c) indirectly in order to know the MAC
139 * address for rules (d) and (e). Note that DHCP for the other
140 * switch will not work unless the controller explicitly lets this
141 * switch pass the traffic.
143 * - Between Switch and Gateway. This switch is between another
144 * switch and the gateway, and we want to allow the other switch's
145 * traffic through. This uses the same rules and logic as the
146 * "Between Switch and Controller" configuration described earlier.
148 * - Controller on Local VM. The controller is a guest VM on the
149 * system running in-band control. This uses rules (a), (b), (c),
152 * - Controller on Local VM with Different Networks. The controller
153 * is a guest VM on the system running in-band control, but the
154 * local port is not used to connect to the controller. For
155 * example, an IP address is configured on eth0 of the switch. The
156 * controller's VM is connected through eth1 of the switch, but an
157 * IP address has not been configured for that port on the switch.
158 * As such, the switch will use eth0 to connect to the controller,
159 * and eth1's rules about the local port will not work. In the
160 * example, the switch attached to eth0 would use rules (a), (b),
161 * (c), (h), and (i) on eth0. The switch attached to eth1 would use
162 * rules (f), (g), (h), and (i).
164 * The following are explicitly *not* supported by in-band control:
166 * - Specify Controller by Name. Currently, the controller must be
167 * identified by IP address. A naive approach would be to permit
168 * all DNS traffic. Unfortunately, this would prevent the
169 * controller from defining any policy over DNS. Since switches
170 * that are located behind us need to connect to the controller,
171 * in-band cannot simply add a rule that allows DNS traffic from
172 * the local port. The "correct" way to support this is to parse
173 * DNS requests to allow all traffic related to a request for the
174 * controller's name through. Due to the potential security
175 * problems and amount of processing, we decided to hold off for
178 * - Differing Controllers for Switches. All switches must know
179 * the L3 addresses for all the controllers that other switches
180 * may use, since rules need to be set up to allow traffic related
181 * to those controllers through. See rules (f), (g), (h), and (i).
183 * - Differing Routes for Switches. In order for the switch to
184 * allow other switches to connect to a controller through a
185 * gateway, it allows the gateway's traffic through with rules (d)
186 * and (e). If the routes to the controller differ for the two
187 * switches, we will not know the MAC address of the alternate
191 /* Priorities used in classifier for in-band rules. These values are higher
192 * than any that may be set with OpenFlow, and "18" kind of looks like "IB".
193 * The ordering of priorities is not important because all of the rules set up
194 * by in-band control have the same action. The only reason to use more than
195 * one priority is to make the kind of flow easier to see during debugging. */
197 IBR_FROM_LOCAL_DHCP = 180000, /* (a) From local port, DHCP. */
198 IBR_TO_LOCAL_ARP, /* (b) To local port, ARP. */
199 IBR_FROM_LOCAL_ARP, /* (c) From local port, ARP. */
200 IBR_TO_REMOTE_ARP, /* (d) To remote MAC, ARP. */
201 IBR_FROM_REMOTE_ARP, /* (e) From remote MAC, ARP. */
202 IBR_TO_CTL_ARP, /* (f) To controller IP, ARP. */
203 IBR_FROM_CTL_ARP, /* (g) From controller IP, ARP. */
204 IBR_TO_CTL_OFP, /* (h) To controller, OpenFlow port. */
205 IBR_FROM_CTL_OFP /* (i) From controller, OpenFlow port. */
208 struct in_band_rule {
211 unsigned int priority;
214 /* Track one remote IP and next hop information. */
215 struct in_band_remote {
216 struct rconn *rconn; /* Connection to remote. */
217 uint32_t remote_ip; /* Remote IP, 0 if unknown. */
218 uint8_t remote_mac[ETH_ADDR_LEN]; /* Next-hop MAC, all-zeros if unknown. */
219 uint8_t last_remote_mac[ETH_ADDR_LEN]; /* Previous nonzero next-hop MAC. */
220 struct netdev *remote_netdev; /* Device to send to next-hop MAC. */
224 struct ofproto *ofproto;
225 struct status_category *ss_cat;
227 /* Remote information. */
228 time_t next_remote_refresh; /* Refresh timer. */
229 struct in_band_remote *remotes;
232 /* Local information. */
233 time_t next_local_refresh; /* Refresh timer. */
234 uint8_t local_mac[ETH_ADDR_LEN]; /* Current MAC. */
235 struct netdev *local_netdev; /* Local port's network device. */
237 /* Local and remote addresses that are installed as flows. */
238 uint8_t installed_local_mac[ETH_ADDR_LEN];
239 uint32_t *remote_ips;
240 uint32_t n_remote_ips;
241 uint8_t *remote_macs;
242 size_t n_remote_macs;
245 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(60, 60);
248 refresh_remote(struct in_band *ib, struct in_band_remote *r)
250 struct in_addr remote_inaddr;
251 struct in_addr next_hop_inaddr;
255 memset(r->remote_mac, 0, sizeof r->remote_mac);
257 /* Get remote IP address. */
258 r->remote_ip = rconn_get_remote_ip(r->rconn);
260 /* No remote IP address means that this rconn is probably either
261 * configured for a non-IP based protocol (e.g. "unix:") or
262 * misconfigured entirely. No point in refreshing quickly. */
266 /* Find the next-hop IP address. */
267 remote_inaddr.s_addr = r->remote_ip;
268 retval = netdev_get_next_hop(ib->local_netdev, &remote_inaddr,
269 &next_hop_inaddr, &next_hop_dev);
271 VLOG_WARN("cannot find route for controller ("IP_FMT"): %s",
272 IP_ARGS(&r->remote_ip), strerror(retval));
275 if (!next_hop_inaddr.s_addr) {
276 next_hop_inaddr.s_addr = remote_inaddr.s_addr;
279 /* Get the next-hop IP and network device. */
280 if (!r->remote_netdev
281 || strcmp(netdev_get_name(r->remote_netdev), next_hop_dev))
283 netdev_close(r->remote_netdev);
285 retval = netdev_open_default(next_hop_dev, &r->remote_netdev);
287 VLOG_WARN_RL(&rl, "cannot open netdev %s (next hop "
288 "to controller "IP_FMT"): %s",
289 next_hop_dev, IP_ARGS(&r->remote_ip),
297 /* Look up the MAC address of the next-hop IP address. */
298 retval = netdev_arp_lookup(r->remote_netdev, next_hop_inaddr.s_addr,
301 VLOG_DBG_RL(&rl, "cannot look up remote MAC address ("IP_FMT"): %s",
302 IP_ARGS(&next_hop_inaddr.s_addr), strerror(retval));
305 /* If we don't have a MAC address, then refresh quickly, since we probably
306 * will get a MAC address soon (via ARP). Otherwise, we can afford to wait
308 return eth_addr_is_zero(r->remote_mac) ? 1 : 10;
312 refresh_remotes(struct in_band *ib)
314 struct in_band_remote *r;
318 if (time_now() < ib->next_remote_refresh) {
324 for (r = ib->remotes; r < &ib->remotes[ib->n_remotes]; r++) {
325 uint8_t old_remote_mac[ETH_ADDR_LEN];
326 int refresh_interval;
329 memcpy(old_remote_mac, r->remote_mac, ETH_ADDR_LEN);
331 /* Refresh remote information. */
332 refresh_interval = refresh_remote(ib, r);
333 min_refresh = MIN(min_refresh, refresh_interval);
335 /* If the MAC changed, log the changes. */
336 if (!eth_addr_equals(r->remote_mac, old_remote_mac)) {
338 if (!eth_addr_is_zero(r->remote_mac)
339 && !eth_addr_equals(r->last_remote_mac, r->remote_mac)) {
340 VLOG_DBG("remote MAC address changed from "ETH_ADDR_FMT
342 ETH_ADDR_ARGS(r->last_remote_mac),
343 ETH_ADDR_ARGS(r->remote_mac));
344 memcpy(r->last_remote_mac, r->remote_mac, ETH_ADDR_LEN);
348 ib->next_remote_refresh = time_now() + min_refresh;
353 /* Refreshes the MAC address of the local port into ib->local_mac, if it is due
354 * for a refresh. Returns true if anything changed, otherwise false. */
356 refresh_local(struct in_band *ib)
358 uint8_t ea[ETH_ADDR_LEN];
362 if (now < ib->next_local_refresh) {
365 ib->next_local_refresh = now + 1;
367 if (netdev_get_etheraddr(ib->local_netdev, ea)
368 || eth_addr_equals(ea, ib->local_mac)) {
372 memcpy(ib->local_mac, ea, ETH_ADDR_LEN);
377 in_band_status_cb(struct status_reply *sr, void *in_band_)
379 struct in_band *in_band = in_band_;
381 if (!eth_addr_is_zero(in_band->local_mac)) {
382 status_reply_put(sr, "local-mac="ETH_ADDR_FMT,
383 ETH_ADDR_ARGS(in_band->local_mac));
386 if (in_band->n_remotes
387 && !eth_addr_is_zero(in_band->remotes[0].remote_mac)) {
388 status_reply_put(sr, "remote-mac="ETH_ADDR_FMT,
389 ETH_ADDR_ARGS(in_band->remotes[0].remote_mac));
393 /* Returns true if 'packet' should be sent to the local port regardless
394 * of the flow table. */
396 in_band_msg_in_hook(struct in_band *in_band, const flow_t *flow,
397 const struct ofpbuf *packet)
403 /* Regardless of how the flow table is configured, we want to be
404 * able to see replies to our DHCP requests. */
405 if (flow->dl_type == htons(ETH_TYPE_IP)
406 && flow->nw_proto == IP_TYPE_UDP
407 && flow->tp_src == htons(DHCP_SERVER_PORT)
408 && flow->tp_dst == htons(DHCP_CLIENT_PORT)
410 struct dhcp_header *dhcp;
412 dhcp = ofpbuf_at(packet, (char *)packet->l7 - (char *)packet->data,
418 refresh_local(in_band);
419 if (!eth_addr_is_zero(in_band->local_mac)
420 && eth_addr_equals(dhcp->chaddr, in_band->local_mac)) {
428 /* Returns true if the rule that would match 'flow' with 'actions' is
429 * allowed to be set up in the datapath. */
431 in_band_rule_check(struct in_band *in_band, const flow_t *flow,
432 const struct odp_actions *actions)
438 /* Don't allow flows that would prevent DHCP replies from being seen
439 * by the local port. */
440 if (flow->dl_type == htons(ETH_TYPE_IP)
441 && flow->nw_proto == IP_TYPE_UDP
442 && flow->tp_src == htons(DHCP_SERVER_PORT)
443 && flow->tp_dst == htons(DHCP_CLIENT_PORT)) {
446 for (i=0; i<actions->n_actions; i++) {
447 if (actions->actions[i].output.type == ODPAT_OUTPUT
448 && actions->actions[i].output.port == ODPP_LOCAL) {
459 init_rule(struct in_band_rule *rule, unsigned int priority)
461 rule->wildcards = OVSFW_ALL;
462 rule->priority = priority;
464 /* Not strictly necessary but seems cleaner. */
465 memset(&rule->flow, 0, sizeof rule->flow);
469 set_in_port(struct in_band_rule *rule, uint16_t odp_port)
471 rule->wildcards &= ~OFPFW_IN_PORT;
472 rule->flow.in_port = odp_port;
476 set_dl_type(struct in_band_rule *rule, uint16_t dl_type)
478 rule->wildcards &= ~OFPFW_DL_TYPE;
479 rule->flow.dl_type = htons(dl_type);
483 set_dl_src(struct in_band_rule *rule, const uint8_t dl_src[ETH_ADDR_LEN])
485 rule->wildcards &= ~OFPFW_DL_SRC;
486 memcpy(rule->flow.dl_src, dl_src, ETH_ADDR_LEN);
490 set_dl_dst(struct in_band_rule *rule, const uint8_t dl_dst[ETH_ADDR_LEN])
492 rule->wildcards &= ~OFPFW_DL_DST;
493 memcpy(rule->flow.dl_dst, dl_dst, ETH_ADDR_LEN);
497 set_tp_src(struct in_band_rule *rule, uint16_t tp_src)
499 rule->wildcards &= ~OFPFW_TP_SRC;
500 rule->flow.tp_src = htons(tp_src);
504 set_tp_dst(struct in_band_rule *rule, uint16_t tp_dst)
506 rule->wildcards &= ~OFPFW_TP_DST;
507 rule->flow.tp_dst = htons(tp_dst);
511 set_nw_proto(struct in_band_rule *rule, uint8_t nw_proto)
513 rule->wildcards &= ~OFPFW_NW_PROTO;
514 rule->flow.nw_proto = nw_proto;
518 set_nw_src(struct in_band_rule *rule, uint32_t nw_src)
520 rule->wildcards &= ~OFPFW_NW_SRC_MASK;
521 rule->flow.nw_src = nw_src;
525 set_nw_dst(struct in_band_rule *rule, uint32_t nw_dst)
527 rule->wildcards &= ~OFPFW_NW_DST_MASK;
528 rule->flow.nw_dst = nw_dst;
532 make_rules(struct in_band *ib,
533 void (*cb)(struct in_band *, const struct in_band_rule *))
535 struct in_band_rule rule;
538 if (!eth_addr_is_zero(ib->installed_local_mac)) {
539 /* Allow DHCP requests to be sent from the local port. */
540 init_rule(&rule, IBR_FROM_LOCAL_DHCP);
541 set_in_port(&rule, ODPP_LOCAL);
542 set_dl_type(&rule, ETH_TYPE_IP);
543 set_dl_src(&rule, ib->installed_local_mac);
544 set_nw_proto(&rule, IP_TYPE_UDP);
545 set_tp_src(&rule, DHCP_CLIENT_PORT);
546 set_tp_dst(&rule, DHCP_SERVER_PORT);
549 /* Allow the connection's interface to receive directed ARP traffic. */
550 init_rule(&rule, IBR_TO_LOCAL_ARP);
551 set_dl_type(&rule, ETH_TYPE_ARP);
552 set_dl_dst(&rule, ib->installed_local_mac);
553 set_nw_proto(&rule, ARP_OP_REPLY);
556 /* Allow the connection's interface to be the source of ARP traffic. */
557 init_rule(&rule, IBR_FROM_LOCAL_ARP);
558 set_dl_type(&rule, ETH_TYPE_ARP);
559 set_dl_src(&rule, ib->installed_local_mac);
560 set_nw_proto(&rule, ARP_OP_REQUEST);
564 for (i = 0; i < ib->n_remote_macs; i++) {
565 const uint8_t *remote_mac = &ib->remote_macs[i * ETH_ADDR_LEN];
568 const uint8_t *prev_mac = &ib->remote_macs[(i - 1) * ETH_ADDR_LEN];
569 if (eth_addr_equals(remote_mac, prev_mac)) {
570 /* Skip duplicates. */
575 /* Allow ARP replies to the remote side's MAC. */
576 init_rule(&rule, IBR_TO_REMOTE_ARP);
577 set_dl_type(&rule, ETH_TYPE_ARP);
578 set_dl_dst(&rule, remote_mac);
579 set_nw_proto(&rule, ARP_OP_REPLY);
582 /* Allow ARP requests from the remote side's MAC. */
583 init_rule(&rule, IBR_FROM_REMOTE_ARP);
584 set_dl_type(&rule, ETH_TYPE_ARP);
585 set_dl_src(&rule, remote_mac);
586 set_nw_proto(&rule, ARP_OP_REQUEST);
590 for (i = 0; i < ib->n_remote_ips; i++) {
591 uint32_t remote_ip = ib->remote_ips[i];
593 if (i > 0 && ib->remote_ips[i - 1] == remote_ip) {
594 /* Skip duplicates. */
598 /* Allow ARP replies to the controller's IP. */
599 init_rule(&rule, IBR_TO_CTL_ARP);
600 set_dl_type(&rule, ETH_TYPE_ARP);
601 set_nw_proto(&rule, ARP_OP_REPLY);
602 set_nw_dst(&rule, remote_ip);
605 /* Allow ARP requests from the controller's IP. */
606 init_rule(&rule, IBR_FROM_CTL_ARP);
607 set_dl_type(&rule, ETH_TYPE_ARP);
608 set_nw_proto(&rule, ARP_OP_REQUEST);
609 set_nw_src(&rule, remote_ip);
612 /* OpenFlow traffic to the controller. */
613 init_rule(&rule, IBR_TO_CTL_OFP);
614 set_dl_type(&rule, ETH_TYPE_IP);
615 set_nw_proto(&rule, IP_TYPE_TCP);
616 set_nw_dst(&rule, remote_ip);
617 set_tp_dst(&rule, OFP_TCP_PORT);
620 /* OpenFlow traffic from the controller. */
621 init_rule(&rule, IBR_FROM_CTL_OFP);
622 set_dl_type(&rule, ETH_TYPE_IP);
623 set_nw_proto(&rule, IP_TYPE_TCP);
624 set_nw_src(&rule, remote_ip);
625 set_tp_src(&rule, OFP_TCP_PORT);
631 clear_rules(struct in_band *ib)
633 memset(ib->installed_local_mac, 0, sizeof ib->installed_local_mac);
635 free(ib->remote_ips);
636 ib->remote_ips = NULL;
637 ib->n_remote_ips = 0;
639 free(ib->remote_macs);
640 ib->remote_macs = NULL;
641 ib->n_remote_macs = 0;
645 drop_rule(struct in_band *ib, const struct in_band_rule *rule)
647 ofproto_delete_flow(ib->ofproto, &rule->flow,
648 rule->wildcards, rule->priority);
652 drop_rules(struct in_band *ib)
654 make_rules(ib, drop_rule);
659 add_rule(struct in_band *ib, const struct in_band_rule *rule)
661 union ofp_action action;
663 action.type = htons(OFPAT_OUTPUT);
664 action.output.len = htons(sizeof action);
665 action.output.port = htons(OFPP_NORMAL);
666 action.output.max_len = htons(0);
667 ofproto_add_flow(ib->ofproto, &rule->flow, rule->wildcards,
668 rule->priority, &action, 1, 0);
672 add_rules(struct in_band *ib)
674 make_rules(ib, add_rule);
678 compare_ips(const void *a, const void *b)
680 return memcmp(a, b, sizeof(uint32_t));
684 compare_macs(const void *a, const void *b)
686 return memcmp(a, b, ETH_ADDR_LEN);
690 in_band_run(struct in_band *ib)
692 struct in_band_remote *r;
693 bool local_change, remote_change;
695 local_change = refresh_local(ib);
696 remote_change = refresh_remotes(ib);
697 if (!local_change && !remote_change) {
698 /* Nothing changed, nothing to do. */
702 /* Drop old rules. */
705 /* Figure out new rules. */
706 memcpy(ib->installed_local_mac, ib->local_mac, ETH_ADDR_LEN);
707 ib->remote_ips = xmalloc(ib->n_remotes * sizeof *ib->remote_ips);
708 ib->n_remote_ips = 0;
709 ib->remote_macs = xmalloc(ib->n_remotes * ETH_ADDR_LEN);
710 ib->n_remote_macs = 0;
711 for (r = ib->remotes; r < &ib->remotes[ib->n_remotes]; r++) {
713 ib->remote_ips[ib->n_remote_ips++] = r->remote_ip;
715 if (!eth_addr_is_zero(r->remote_mac)) {
716 memcpy(&ib->remote_macs[ib->n_remote_macs * ETH_ADDR_LEN],
717 r->remote_mac, ETH_ADDR_LEN);
722 /* Sort, to allow make_rules() to easily skip duplicates. */
723 qsort(ib->remote_ips, ib->n_remote_ips, sizeof *ib->remote_ips,
725 qsort(ib->remote_macs, ib->n_remote_macs, ETH_ADDR_LEN, compare_macs);
732 in_band_wait(struct in_band *in_band)
734 time_t now = time_now();
736 = MIN(in_band->next_remote_refresh, in_band->next_local_refresh);
738 poll_timer_wait((wakeup - now) * 1000);
740 poll_immediate_wake();
744 /* ofproto has flushed all flows from the flow table and it is calling us back
745 * to allow us to reinstall the ones that are important to us. */
747 in_band_flushed(struct in_band *in_band)
753 in_band_create(struct ofproto *ofproto, struct dpif *dpif,
754 struct switch_status *ss, struct in_band **in_bandp)
756 struct in_band *in_band;
757 char local_name[IF_NAMESIZE];
758 struct netdev *local_netdev;
761 error = dpif_port_get_name(dpif, ODPP_LOCAL,
762 local_name, sizeof local_name);
764 VLOG_ERR("failed to initialize in-band control: cannot get name "
765 "of datapath local port (%s)", strerror(error));
769 error = netdev_open_default(local_name, &local_netdev);
771 VLOG_ERR("failed to initialize in-band control: cannot open "
772 "datapath local port %s (%s)", local_name, strerror(error));
776 in_band = xzalloc(sizeof *in_band);
777 in_band->ofproto = ofproto;
778 in_band->ss_cat = switch_status_register(ss, "in-band",
779 in_band_status_cb, in_band);
780 in_band->next_remote_refresh = TIME_MIN;
781 in_band->next_local_refresh = TIME_MIN;
782 in_band->local_netdev = local_netdev;
790 in_band_destroy(struct in_band *ib)
794 in_band_set_remotes(ib, NULL, 0);
795 switch_status_unregister(ib->ss_cat);
796 netdev_close(ib->local_netdev);
802 in_band_set_remotes(struct in_band *ib, struct rconn **remotes, size_t n)
806 /* Optimize the case where the rconns are the same as last time. */
807 if (n == ib->n_remotes) {
808 for (i = 0; i < n; i++) {
809 if (ib->remotes[i].rconn != remotes[i]) {
818 for (i = 0; i < ib->n_remotes; i++) {
819 /* We don't own the rconn. */
820 netdev_close(ib->remotes[i].remote_netdev);
824 ib->next_remote_refresh = TIME_MIN;
825 ib->remotes = n ? xzalloc(n * sizeof *ib->remotes) : 0;
827 for (i = 0; i < n; i++) {
828 ib->remotes[i].rconn = remotes[i];