2 * Copyright (c) 2008, 2009, 2010, 2011 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>
22 #include <sys/socket.h>
26 #include "classifier.h"
35 #include "openflow/openflow.h"
37 #include "poll-loop.h"
42 VLOG_DEFINE_THIS_MODULE(in_band);
44 /* In-band control allows a single network to be used for OpenFlow traffic and
45 * other data traffic. See ovs-vswitchd.conf.db(5) for a description of
46 * configuring in-band control.
48 * This comment is an attempt to describe how in-band control works at a
49 * wire- and implementation-level. Correctly implementing in-band
50 * control has proven difficult due to its many subtleties, and has thus
51 * gone through many iterations. Please read through and understand the
52 * reasoning behind the chosen rules before making modifications.
54 * In Open vSwitch, in-band control is implemented as "hidden" flows (in that
55 * they are not visible through OpenFlow) and at a higher priority than
56 * wildcarded flows can be set up by through OpenFlow. This is done so that
57 * the OpenFlow controller cannot interfere with them and possibly break
58 * connectivity with its switches. It is possible to see all flows, including
59 * in-band ones, with the ovs-appctl "bridge/dump-flows" command.
61 * The Open vSwitch implementation of in-band control can hide traffic to
62 * arbitrary "remotes", where each remote is one TCP port on one IP address.
63 * Currently the remotes are automatically configured as the in-band OpenFlow
64 * controllers plus the OVSDB managers, if any. (The latter is a requirement
65 * because OVSDB managers are responsible for configuring OpenFlow controllers,
66 * so if the manager cannot be reached then OpenFlow cannot be reconfigured.)
68 * The following rules (with the OFPP_NORMAL action) are set up on any bridge
69 * that has any remotes:
71 * (a) DHCP requests sent from the local port.
72 * (b) ARP replies to the local port's MAC address.
73 * (c) ARP requests from the local port's MAC address.
75 * In-band also sets up the following rules for each unique next-hop MAC
76 * address for the remotes' IPs (the "next hop" is either the remote
77 * itself, if it is on a local subnet, or the gateway to reach the remote):
79 * (d) ARP replies to the next hop's MAC address.
80 * (e) ARP requests from the next hop's MAC address.
82 * In-band also sets up the following rules for each unique remote IP address:
84 * (f) ARP replies containing the remote's IP address as a target.
85 * (g) ARP requests containing the remote's IP address as a source.
87 * In-band also sets up the following rules for each unique remote (IP,port)
90 * (h) TCP traffic to the remote's IP and port.
91 * (i) TCP traffic from the remote's IP and port.
93 * The goal of these rules is to be as narrow as possible to allow a
94 * switch to join a network and be able to communicate with the
95 * remotes. As mentioned earlier, these rules have higher priority
96 * than the controller's rules, so if they are too broad, they may
97 * prevent the controller from implementing its policy. As such,
98 * in-band actively monitors some aspects of flow and packet processing
99 * so that the rules can be made more precise.
101 * In-band control monitors attempts to add flows into the datapath that
102 * could interfere with its duties. The datapath only allows exact
103 * match entries, so in-band control is able to be very precise about
104 * the flows it prevents. Flows that miss in the datapath are sent to
105 * userspace to be processed, so preventing these flows from being
106 * cached in the "fast path" does not affect correctness. The only type
107 * of flow that is currently prevented is one that would prevent DHCP
108 * replies from being seen by the local port. For example, a rule that
109 * forwarded all DHCP traffic to the controller would not be allowed,
110 * but one that forwarded to all ports (including the local port) would.
112 * As mentioned earlier, packets that miss in the datapath are sent to
113 * the userspace for processing. The userspace has its own flow table,
114 * the "classifier", so in-band checks whether any special processing
115 * is needed before the classifier is consulted. If a packet is a DHCP
116 * response to a request from the local port, the packet is forwarded to
117 * the local port, regardless of the flow table. Note that this requires
118 * L7 processing of DHCP replies to determine whether the 'chaddr' field
119 * matches the MAC address of the local port.
121 * It is interesting to note that for an L3-based in-band control
122 * mechanism, the majority of rules are devoted to ARP traffic. At first
123 * glance, some of these rules appear redundant. However, each serves an
124 * important role. First, in order to determine the MAC address of the
125 * remote side (controller or gateway) for other ARP rules, we must allow
126 * ARP traffic for our local port with rules (b) and (c). If we are
127 * between a switch and its connection to the remote, we have to
128 * allow the other switch's ARP traffic to through. This is done with
129 * rules (d) and (e), since we do not know the addresses of the other
130 * switches a priori, but do know the remote's or gateway's. Finally,
131 * if the remote is running in a local guest VM that is not reached
132 * through the local port, the switch that is connected to the VM must
133 * allow ARP traffic based on the remote's IP address, since it will
134 * not know the MAC address of the local port that is sending the traffic
135 * or the MAC address of the remote in the guest VM.
137 * With a few notable exceptions below, in-band should work in most
138 * network setups. The following are considered "supported' in the
139 * current implementation:
141 * - Locally Connected. The switch and remote are on the same
142 * subnet. This uses rules (a), (b), (c), (h), and (i).
144 * - Reached through Gateway. The switch and remote are on
145 * different subnets and must go through a gateway. This uses
146 * rules (a), (b), (c), (h), and (i).
148 * - Between Switch and Remote. This switch is between another
149 * switch and the remote, and we want to allow the other
150 * switch's traffic through. This uses rules (d), (e), (h), and
151 * (i). It uses (b) and (c) indirectly in order to know the MAC
152 * address for rules (d) and (e). Note that DHCP for the other
153 * switch will not work unless an OpenFlow controller explicitly lets this
154 * switch pass the traffic.
156 * - Between Switch and Gateway. This switch is between another
157 * switch and the gateway, and we want to allow the other switch's
158 * traffic through. This uses the same rules and logic as the
159 * "Between Switch and Remote" configuration described earlier.
161 * - Remote on Local VM. The remote is a guest VM on the
162 * system running in-band control. This uses rules (a), (b), (c),
165 * - Remote on Local VM with Different Networks. The remote
166 * is a guest VM on the system running in-band control, but the
167 * local port is not used to connect to the remote. For
168 * example, an IP address is configured on eth0 of the switch. The
169 * remote's VM is connected through eth1 of the switch, but an
170 * IP address has not been configured for that port on the switch.
171 * As such, the switch will use eth0 to connect to the remote,
172 * and eth1's rules about the local port will not work. In the
173 * example, the switch attached to eth0 would use rules (a), (b),
174 * (c), (h), and (i) on eth0. The switch attached to eth1 would use
175 * rules (f), (g), (h), and (i).
177 * The following are explicitly *not* supported by in-band control:
179 * - Specify Remote by Name. Currently, the remote must be
180 * identified by IP address. A naive approach would be to permit
181 * all DNS traffic. Unfortunately, this would prevent the
182 * controller from defining any policy over DNS. Since switches
183 * that are located behind us need to connect to the remote,
184 * in-band cannot simply add a rule that allows DNS traffic from
185 * the local port. The "correct" way to support this is to parse
186 * DNS requests to allow all traffic related to a request for the
187 * remote's name through. Due to the potential security
188 * problems and amount of processing, we decided to hold off for
191 * - Differing Remotes for Switches. All switches must know
192 * the L3 addresses for all the remotes that other switches
193 * may use, since rules need to be set up to allow traffic related
194 * to those remotes through. See rules (f), (g), (h), and (i).
196 * - Differing Routes for Switches. In order for the switch to
197 * allow other switches to connect to a remote through a
198 * gateway, it allows the gateway's traffic through with rules (d)
199 * and (e). If the routes to the remote differ for the two
200 * switches, we will not know the MAC address of the alternate
204 /* Priorities used in classifier for in-band rules. These values are higher
205 * than any that may be set with OpenFlow, and "18" kind of looks like "IB".
206 * The ordering of priorities is not important because all of the rules set up
207 * by in-band control have the same action. The only reason to use more than
208 * one priority is to make the kind of flow easier to see during debugging. */
210 /* One set per bridge. */
211 IBR_FROM_LOCAL_DHCP = 180000, /* (a) From local port, DHCP. */
212 IBR_TO_LOCAL_ARP, /* (b) To local port, ARP. */
213 IBR_FROM_LOCAL_ARP, /* (c) From local port, ARP. */
215 /* One set per unique next-hop MAC. */
216 IBR_TO_NEXT_HOP_ARP, /* (d) To remote MAC, ARP. */
217 IBR_FROM_NEXT_HOP_ARP, /* (e) From remote MAC, ARP. */
219 /* One set per unique remote IP address. */
220 IBR_TO_REMOTE_ARP, /* (f) To remote IP, ARP. */
221 IBR_FROM_REMOTE_ARP, /* (g) From remote IP, ARP. */
223 /* One set per unique remote (IP,port) pair. */
224 IBR_TO_REMOTE_TCP, /* (h) To remote IP, TCP port. */
225 IBR_FROM_REMOTE_TCP /* (i) From remote IP, TCP port. */
228 /* Track one remote IP and next hop information. */
229 struct in_band_remote {
230 struct sockaddr_in remote_addr; /* IP address, in network byte order. */
231 uint8_t remote_mac[ETH_ADDR_LEN]; /* Next-hop MAC, all-zeros if unknown. */
232 uint8_t last_remote_mac[ETH_ADDR_LEN]; /* Previous nonzero next-hop MAC. */
233 struct netdev *remote_netdev; /* Device to send to next-hop MAC. */
237 struct ofproto *ofproto;
238 int queue_id, prev_queue_id;
240 /* Remote information. */
241 time_t next_remote_refresh; /* Refresh timer. */
242 struct in_band_remote *remotes;
245 /* Local information. */
246 time_t next_local_refresh; /* Refresh timer. */
247 uint8_t local_mac[ETH_ADDR_LEN]; /* Current MAC. */
248 struct netdev *local_netdev; /* Local port's network device. */
250 /* Local and remote addresses that are installed as flows. */
251 uint8_t installed_local_mac[ETH_ADDR_LEN];
252 struct sockaddr_in *remote_addrs;
253 size_t n_remote_addrs;
254 uint8_t *remote_macs;
255 size_t n_remote_macs;
258 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(60, 60);
261 refresh_remote(struct in_band *ib, struct in_band_remote *r)
263 struct in_addr next_hop_inaddr;
267 /* Find the next-hop IP address. */
268 memset(r->remote_mac, 0, sizeof r->remote_mac);
269 retval = netdev_get_next_hop(ib->local_netdev, &r->remote_addr.sin_addr,
270 &next_hop_inaddr, &next_hop_dev);
272 VLOG_WARN("cannot find route for controller ("IP_FMT"): %s",
273 IP_ARGS(&r->remote_addr.sin_addr), strerror(retval));
276 if (!next_hop_inaddr.s_addr) {
277 next_hop_inaddr = r->remote_addr.sin_addr;
280 /* Open the next-hop network device. */
281 if (!r->remote_netdev
282 || strcmp(netdev_get_name(r->remote_netdev), next_hop_dev))
284 netdev_close(r->remote_netdev);
286 retval = netdev_open_default(next_hop_dev, &r->remote_netdev);
288 VLOG_WARN_RL(&rl, "cannot open netdev %s (next hop "
289 "to controller "IP_FMT"): %s",
290 next_hop_dev, IP_ARGS(&r->remote_addr.sin_addr),
298 /* Look up the MAC address of the next-hop IP address. */
299 retval = netdev_arp_lookup(r->remote_netdev, next_hop_inaddr.s_addr,
302 VLOG_DBG_RL(&rl, "cannot look up remote MAC address ("IP_FMT"): %s",
303 IP_ARGS(&next_hop_inaddr.s_addr), strerror(retval));
306 /* If we don't have a MAC address, then refresh quickly, since we probably
307 * will get a MAC address soon (via ARP). Otherwise, we can afford to wait
309 return eth_addr_is_zero(r->remote_mac) ? 1 : 10;
313 refresh_remotes(struct in_band *ib)
315 struct in_band_remote *r;
318 if (time_now() < ib->next_remote_refresh) {
323 ib->next_remote_refresh = TIME_MAX;
324 for (r = ib->remotes; r < &ib->remotes[ib->n_remotes]; r++) {
325 uint8_t old_remote_mac[ETH_ADDR_LEN];
329 memcpy(old_remote_mac, r->remote_mac, ETH_ADDR_LEN);
331 /* Refresh remote information. */
332 next_refresh = refresh_remote(ib, r) + time_now();
333 ib->next_remote_refresh = MIN(ib->next_remote_refresh, next_refresh);
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);
352 /* Refreshes the MAC address of the local port into ib->local_mac, if it is due
353 * for a refresh. Returns true if anything changed, otherwise false. */
355 refresh_local(struct in_band *ib)
357 uint8_t ea[ETH_ADDR_LEN];
361 if (now < ib->next_local_refresh) {
364 ib->next_local_refresh = now + 1;
366 if (netdev_get_etheraddr(ib->local_netdev, ea)
367 || eth_addr_equals(ea, ib->local_mac)) {
371 memcpy(ib->local_mac, ea, ETH_ADDR_LEN);
375 /* Returns true if 'packet' should be sent to the local port regardless
376 * of the flow table. */
378 in_band_msg_in_hook(struct in_band *in_band, const struct flow *flow,
379 const struct ofpbuf *packet)
381 /* Regardless of how the flow table is configured, we want to be
382 * able to see replies to our DHCP requests. */
383 if (flow->dl_type == htons(ETH_TYPE_IP)
384 && flow->nw_proto == IPPROTO_UDP
385 && flow->tp_src == htons(DHCP_SERVER_PORT)
386 && flow->tp_dst == htons(DHCP_CLIENT_PORT)
388 struct dhcp_header *dhcp;
390 dhcp = ofpbuf_at(packet, (char *)packet->l7 - (char *)packet->data,
396 refresh_local(in_band);
397 if (!eth_addr_is_zero(in_band->local_mac)
398 && eth_addr_equals(dhcp->chaddr, in_band->local_mac)) {
406 /* Returns true if the rule that would match 'flow' with 'actions' is
407 * allowed to be set up in the datapath. */
409 in_band_rule_check(const struct flow *flow,
410 const struct nlattr *actions, size_t actions_len)
412 /* Don't allow flows that would prevent DHCP replies from being seen
413 * by the local port. */
414 if (flow->dl_type == htons(ETH_TYPE_IP)
415 && flow->nw_proto == IPPROTO_UDP
416 && flow->tp_src == htons(DHCP_SERVER_PORT)
417 && flow->tp_dst == htons(DHCP_CLIENT_PORT)) {
418 const struct nlattr *a;
421 NL_ATTR_FOR_EACH_UNSAFE (a, left, actions, actions_len) {
422 if (nl_attr_type(a) == ODP_ACTION_ATTR_OUTPUT
423 && nl_attr_get_u32(a) == ODPP_LOCAL) {
434 make_rules(struct in_band *ib,
435 void (*cb)(struct in_band *, const struct cls_rule *))
437 struct cls_rule rule;
440 if (!eth_addr_is_zero(ib->installed_local_mac)) {
441 /* (a) Allow DHCP requests sent from the local port. */
442 cls_rule_init_catchall(&rule, IBR_FROM_LOCAL_DHCP);
443 cls_rule_set_in_port(&rule, ODPP_LOCAL);
444 cls_rule_set_dl_type(&rule, htons(ETH_TYPE_IP));
445 cls_rule_set_dl_src(&rule, ib->installed_local_mac);
446 cls_rule_set_nw_proto(&rule, IPPROTO_UDP);
447 cls_rule_set_tp_src(&rule, htons(DHCP_CLIENT_PORT));
448 cls_rule_set_tp_dst(&rule, htons(DHCP_SERVER_PORT));
451 /* (b) Allow ARP replies to the local port's MAC address. */
452 cls_rule_init_catchall(&rule, IBR_TO_LOCAL_ARP);
453 cls_rule_set_dl_type(&rule, htons(ETH_TYPE_ARP));
454 cls_rule_set_dl_dst(&rule, ib->installed_local_mac);
455 cls_rule_set_nw_proto(&rule, ARP_OP_REPLY);
458 /* (c) Allow ARP requests from the local port's MAC address. */
459 cls_rule_init_catchall(&rule, IBR_FROM_LOCAL_ARP);
460 cls_rule_set_dl_type(&rule, htons(ETH_TYPE_ARP));
461 cls_rule_set_dl_src(&rule, ib->installed_local_mac);
462 cls_rule_set_nw_proto(&rule, ARP_OP_REQUEST);
466 for (i = 0; i < ib->n_remote_macs; i++) {
467 const uint8_t *remote_mac = &ib->remote_macs[i * ETH_ADDR_LEN];
470 const uint8_t *prev_mac = &ib->remote_macs[(i - 1) * ETH_ADDR_LEN];
471 if (eth_addr_equals(remote_mac, prev_mac)) {
472 /* Skip duplicates. */
477 /* (d) Allow ARP replies to the next hop's MAC address. */
478 cls_rule_init_catchall(&rule, IBR_TO_NEXT_HOP_ARP);
479 cls_rule_set_dl_type(&rule, htons(ETH_TYPE_ARP));
480 cls_rule_set_dl_dst(&rule, remote_mac);
481 cls_rule_set_nw_proto(&rule, ARP_OP_REPLY);
484 /* (e) Allow ARP requests from the next hop's MAC address. */
485 cls_rule_init_catchall(&rule, IBR_FROM_NEXT_HOP_ARP);
486 cls_rule_set_dl_type(&rule, htons(ETH_TYPE_ARP));
487 cls_rule_set_dl_src(&rule, remote_mac);
488 cls_rule_set_nw_proto(&rule, ARP_OP_REQUEST);
492 for (i = 0; i < ib->n_remote_addrs; i++) {
493 const struct sockaddr_in *a = &ib->remote_addrs[i];
495 if (!i || a->sin_addr.s_addr != a[-1].sin_addr.s_addr) {
496 /* (f) Allow ARP replies containing the remote's IP address as a
498 cls_rule_init_catchall(&rule, IBR_TO_REMOTE_ARP);
499 cls_rule_set_dl_type(&rule, htons(ETH_TYPE_ARP));
500 cls_rule_set_nw_proto(&rule, ARP_OP_REPLY);
501 cls_rule_set_nw_dst(&rule, a->sin_addr.s_addr);
504 /* (g) Allow ARP requests containing the remote's IP address as a
506 cls_rule_init_catchall(&rule, IBR_FROM_REMOTE_ARP);
507 cls_rule_set_dl_type(&rule, htons(ETH_TYPE_ARP));
508 cls_rule_set_nw_proto(&rule, ARP_OP_REQUEST);
509 cls_rule_set_nw_src(&rule, a->sin_addr.s_addr);
514 || a->sin_addr.s_addr != a[-1].sin_addr.s_addr
515 || a->sin_port != a[-1].sin_port) {
516 /* (h) Allow TCP traffic to the remote's IP and port. */
517 cls_rule_init_catchall(&rule, IBR_TO_REMOTE_TCP);
518 cls_rule_set_dl_type(&rule, htons(ETH_TYPE_IP));
519 cls_rule_set_nw_proto(&rule, IPPROTO_TCP);
520 cls_rule_set_nw_dst(&rule, a->sin_addr.s_addr);
521 cls_rule_set_tp_dst(&rule, a->sin_port);
524 /* (i) Allow TCP traffic from the remote's IP and port. */
525 cls_rule_init_catchall(&rule, IBR_FROM_REMOTE_TCP);
526 cls_rule_set_dl_type(&rule, htons(ETH_TYPE_IP));
527 cls_rule_set_nw_proto(&rule, IPPROTO_TCP);
528 cls_rule_set_nw_src(&rule, a->sin_addr.s_addr);
529 cls_rule_set_tp_src(&rule, a->sin_port);
536 drop_rule(struct in_band *ib, const struct cls_rule *rule)
538 ofproto_delete_flow(ib->ofproto, rule);
541 /* Drops from the flow table all of the flows set up by 'ib', then clears out
542 * the information about the installed flows so that they can be filled in
543 * again if necessary. */
545 drop_rules(struct in_band *ib)
548 make_rules(ib, drop_rule);
550 /* Clear out state. */
551 memset(ib->installed_local_mac, 0, sizeof ib->installed_local_mac);
553 free(ib->remote_addrs);
554 ib->remote_addrs = NULL;
555 ib->n_remote_addrs = 0;
557 free(ib->remote_macs);
558 ib->remote_macs = NULL;
559 ib->n_remote_macs = 0;
563 add_rule(struct in_band *ib, const struct cls_rule *rule)
566 struct nx_action_set_queue nxsq;
567 struct ofp_action_output oao;
570 memset(&actions, 0, sizeof actions);
572 actions.oao.type = htons(OFPAT_OUTPUT);
573 actions.oao.len = htons(sizeof actions.oao);
574 actions.oao.port = htons(OFPP_NORMAL);
575 actions.oao.max_len = htons(0);
577 if (ib->queue_id < 0) {
578 ofproto_add_flow(ib->ofproto, rule,
579 (union ofp_action *) &actions.oao, 1);
581 actions.nxsq.type = htons(OFPAT_VENDOR);
582 actions.nxsq.len = htons(sizeof actions.nxsq);
583 actions.nxsq.vendor = htonl(NX_VENDOR_ID);
584 actions.nxsq.subtype = htons(NXAST_SET_QUEUE);
585 actions.nxsq.queue_id = htonl(ib->queue_id);
587 ofproto_add_flow(ib->ofproto, rule, (union ofp_action *) &actions,
588 sizeof actions / sizeof(union ofp_action));
592 /* Inserts flows into the flow table for the current state of 'ib'. */
594 add_rules(struct in_band *ib)
596 make_rules(ib, add_rule);
600 compare_addrs(const void *a_, const void *b_)
602 const struct sockaddr_in *a = a_;
603 const struct sockaddr_in *b = b_;
606 cmp = memcmp(&a->sin_addr.s_addr,
608 sizeof a->sin_addr.s_addr);
612 return memcmp(&a->sin_port, &b->sin_port, sizeof a->sin_port);
616 compare_macs(const void *a, const void *b)
618 return eth_addr_compare_3way(a, b);
622 in_band_run(struct in_band *ib)
624 bool local_change, remote_change, queue_id_change;
625 struct in_band_remote *r;
627 local_change = refresh_local(ib);
628 remote_change = refresh_remotes(ib);
629 queue_id_change = ib->queue_id != ib->prev_queue_id;
630 if (!local_change && !remote_change && !queue_id_change) {
631 /* Nothing changed, nothing to do. */
634 ib->prev_queue_id = ib->queue_id;
636 /* Drop old rules. */
639 /* Figure out new rules. */
640 memcpy(ib->installed_local_mac, ib->local_mac, ETH_ADDR_LEN);
641 ib->remote_addrs = xmalloc(ib->n_remotes * sizeof *ib->remote_addrs);
642 ib->n_remote_addrs = 0;
643 ib->remote_macs = xmalloc(ib->n_remotes * ETH_ADDR_LEN);
644 ib->n_remote_macs = 0;
645 for (r = ib->remotes; r < &ib->remotes[ib->n_remotes]; r++) {
646 ib->remote_addrs[ib->n_remote_addrs++] = r->remote_addr;
647 if (!eth_addr_is_zero(r->remote_mac)) {
648 memcpy(&ib->remote_macs[ib->n_remote_macs * ETH_ADDR_LEN],
649 r->remote_mac, ETH_ADDR_LEN);
654 /* Sort, to allow make_rules() to easily skip duplicates. */
655 qsort(ib->remote_addrs, ib->n_remote_addrs, sizeof *ib->remote_addrs,
657 qsort(ib->remote_macs, ib->n_remote_macs, ETH_ADDR_LEN, compare_macs);
664 in_band_wait(struct in_band *in_band)
667 = MIN(in_band->next_remote_refresh, in_band->next_local_refresh);
668 poll_timer_wait_until(wakeup * 1000);
671 /* ofproto has flushed all flows from the flow table and it is calling us back
672 * to allow us to reinstall the ones that are important to us. */
674 in_band_flushed(struct in_band *in_band)
680 in_band_create(struct ofproto *ofproto, const char *local_name,
681 struct in_band **in_bandp)
683 struct in_band *in_band;
684 struct netdev *local_netdev;
688 error = netdev_open_default(local_name, &local_netdev);
690 VLOG_ERR("failed to initialize in-band control: cannot open "
691 "datapath local port %s (%s)", local_name, strerror(error));
695 in_band = xzalloc(sizeof *in_band);
696 in_band->ofproto = ofproto;
697 in_band->queue_id = in_band->prev_queue_id = -1;
698 in_band->next_remote_refresh = TIME_MIN;
699 in_band->next_local_refresh = TIME_MIN;
700 in_band->local_netdev = local_netdev;
708 in_band_destroy(struct in_band *ib)
712 in_band_set_remotes(ib, NULL, 0);
713 netdev_close(ib->local_netdev);
719 any_addresses_changed(struct in_band *ib,
720 const struct sockaddr_in *addresses, size_t n)
724 if (n != ib->n_remotes) {
728 for (i = 0; i < n; i++) {
729 const struct sockaddr_in *old = &ib->remotes[i].remote_addr;
730 const struct sockaddr_in *new = &addresses[i];
732 if (old->sin_addr.s_addr != new->sin_addr.s_addr ||
733 old->sin_port != new->sin_port) {
742 in_band_set_remotes(struct in_band *ib,
743 const struct sockaddr_in *addresses, size_t n)
747 if (!any_addresses_changed(ib, addresses, n)) {
751 /* Clear old remotes. */
752 for (i = 0; i < ib->n_remotes; i++) {
753 netdev_close(ib->remotes[i].remote_netdev);
757 /* Set up new remotes. */
758 ib->remotes = n ? xzalloc(n * sizeof *ib->remotes) : NULL;
760 for (i = 0; i < n; i++) {
761 ib->remotes[i].remote_addr = addresses[i];
764 /* Force refresh in next call to in_band_run(). */
765 ib->next_remote_refresh = TIME_MIN;
768 /* Sets the OpenFlow queue used by flows set up by 'ib' to 'queue_id'. If
769 * 'queue_id' is negative, 'ib' will not set any queue (which is also the
772 in_band_set_queue(struct in_band *ib, int queue_id)
774 ib->queue_id = queue_id;