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1 : : /*
2 : : * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2015, 2016 Nicira, Inc.
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 : : #include <config.h>
18 : : #include <inttypes.h>
19 : : #include <stdlib.h>
20 : : #include "classifier.h"
21 : : #include "connmgr.h"
22 : : #include "dp-packet.h"
23 : : #include "fail-open.h"
24 : : #include "flow.h"
25 : : #include "mac-learning.h"
26 : : #include "odp-util.h"
27 : : #include "openvswitch/ofp-actions.h"
28 : : #include "openvswitch/ofp-util.h"
29 : : #include "openvswitch/ofpbuf.h"
30 : : #include "openvswitch/vconn.h"
31 : : #include "openvswitch/vlog.h"
32 : : #include "ofproto.h"
33 : : #include "ofproto-provider.h"
34 : : #include "poll-loop.h"
35 : : #include "rconn.h"
36 : : #include "timeval.h"
37 : :
38 : 1288 : VLOG_DEFINE_THIS_MODULE(fail_open);
39 : :
40 : : /*
41 : : * Fail-open mode.
42 : : *
43 : : * In fail-open mode, the switch detects when the controller cannot be
44 : : * contacted or when the controller is dropping switch connections because the
45 : : * switch does not pass its admission control policy. In those situations the
46 : : * switch sets up flows itself using the "normal" action.
47 : : *
48 : : * There is a little subtlety to implementation, to properly handle the case
49 : : * where the controller allows switch connections but drops them a few seconds
50 : : * later for admission control reasons. Because of this case, we don't want to
51 : : * just stop setting up flows when we connect to the controller: if we did,
52 : : * then new flow setup and existing flows would stop during the duration of
53 : : * connection to the controller, and thus the whole network would go down for
54 : : * that period of time.
55 : : *
56 : : * So, instead, we add some special cases when we are connected to a
57 : : * controller, but not yet sure that it has admitted us:
58 : : *
59 : : * - We set up flows immediately ourselves, but simultaneously send out an
60 : : * OFPT_PACKET_IN to the controller. We put a special bogus buffer-id in
61 : : * these OFPT_PACKET_IN messages so that duplicate packets don't get sent
62 : : * out to the network when the controller replies.
63 : : *
64 : : * - We also send out OFPT_PACKET_IN messages for totally bogus packets
65 : : * every so often, in case no real new flows are arriving in the network.
66 : : *
67 : : * - We don't flush the flow table at the time we connect, because this
68 : : * could cause network stuttering in a switch with lots of flows or very
69 : : * high-bandwidth flows by suddenly throwing lots of packets down to
70 : : * userspace.
71 : : */
72 : :
73 : : struct fail_open {
74 : : struct ofproto *ofproto;
75 : : struct connmgr *connmgr;
76 : : int last_disconn_secs;
77 : : long long int next_bogus_packet_in;
78 : : struct rconn_packet_counter *bogus_packet_counter;
79 : : bool fail_open_active;
80 : : };
81 : :
82 : : static void fail_open_recover(struct fail_open *);
83 : :
84 : : /* Returns the number of seconds of disconnection after which fail-open mode
85 : : * should activate. */
86 : : static int
87 : 0 : trigger_duration(const struct fail_open *fo)
88 : : {
89 [ # # ]: 0 : if (!connmgr_has_controllers(fo->connmgr)) {
90 : : /* Shouldn't ever arrive here, but if we do, never fail open. */
91 : 0 : return INT_MAX;
92 : : } else {
93 : : /* Otherwise, every controller must have a chance to send an
94 : : * inactivity probe and reconnect before we fail open, so take the
95 : : * maximum probe interval and multiply by 3:
96 : : *
97 : : * - The first interval is the idle time before sending an inactivity
98 : : * probe.
99 : : *
100 : : * - The second interval is the time allowed for a response to the
101 : : * inactivity probe.
102 : : *
103 : : * - The third interval is the time allowed to reconnect after no
104 : : * response is received.
105 : : */
106 : 0 : return connmgr_get_max_probe_interval(fo->connmgr) * 3;
107 : : }
108 : : }
109 : :
110 : : /* Returns true if 'fo' is currently in fail-open mode, otherwise false. */
111 : : bool
112 : 0 : fail_open_is_active(const struct fail_open *fo)
113 : : {
114 : 0 : return fo->last_disconn_secs != 0;
115 : : }
116 : :
117 : : static void
118 : 0 : send_bogus_packet_ins(struct fail_open *fo)
119 : : {
120 : : struct eth_addr mac;
121 : : struct dp_packet b;
122 : :
123 : 0 : dp_packet_init(&b, 128);
124 : 0 : eth_addr_nicira_random(&mac);
125 : 0 : compose_rarp(&b, mac);
126 : :
127 : 0 : struct ofproto_async_msg am = {
128 : : .oam = OAM_PACKET_IN,
129 : : .pin = {
130 : : .up = {
131 : : .public = {
132 : 0 : .packet = dp_packet_data(&b),
133 : 0 : .packet_len = dp_packet_size(&b),
134 : : .flow_metadata = MATCH_CATCHALL_INITIALIZER,
135 : : .flow_metadata.flow.in_port.ofp_port = OFPP_LOCAL,
136 : : .flow_metadata.wc.masks.in_port.ofp_port
137 : 0 : = u16_to_ofp(UINT16_MAX),
138 : : .reason = OFPR_NO_MATCH,
139 : : .cookie = OVS_BE64_MAX,
140 : : },
141 : : },
142 : : .max_len = UINT16_MAX,
143 : : }
144 : : };
145 : 0 : connmgr_send_async_msg(fo->connmgr, &am);
146 : :
147 : 0 : dp_packet_uninit(&b);
148 : 0 : }
149 : :
150 : : /* Enter fail-open mode if we should be in it. */
151 : : void
152 : 0 : fail_open_run(struct fail_open *fo)
153 : : {
154 : 0 : int disconn_secs = connmgr_failure_duration(fo->connmgr);
155 : :
156 : : /* Enter fail-open mode if 'fo' is not in it but should be. */
157 [ # # ]: 0 : if (disconn_secs >= trigger_duration(fo)) {
158 [ # # ]: 0 : if (!fail_open_is_active(fo)) {
159 [ # # ]: 0 : VLOG_WARN("Could not connect to controller (or switch failed "
160 : : "controller's post-connection admission control "
161 : : "policy) for %d seconds, failing open", disconn_secs);
162 : 0 : fo->last_disconn_secs = disconn_secs;
163 : :
164 : : /* Flush all OpenFlow and datapath flows. We will set up our
165 : : * fail-open rule from fail_open_flushed() when
166 : : * ofproto_flush_flows() calls back to us. */
167 : 0 : ofproto_flush_flows(fo->ofproto);
168 [ # # ]: 0 : } else if (disconn_secs > fo->last_disconn_secs + 60) {
169 [ # # ]: 0 : VLOG_INFO("Still in fail-open mode after %d seconds disconnected "
170 : : "from controller", disconn_secs);
171 : 0 : fo->last_disconn_secs = disconn_secs;
172 : : }
173 : : }
174 : :
175 : : /* Schedule a bogus packet-in if we're connected and in fail-open. */
176 [ # # ]: 0 : if (fail_open_is_active(fo)) {
177 [ # # ]: 0 : if (connmgr_is_any_controller_connected(fo->connmgr)) {
178 : 0 : bool expired = time_msec() >= fo->next_bogus_packet_in;
179 [ # # ]: 0 : if (expired) {
180 : 0 : send_bogus_packet_ins(fo);
181 : : }
182 [ # # ][ # # ]: 0 : if (expired || fo->next_bogus_packet_in == LLONG_MAX) {
183 : 0 : fo->next_bogus_packet_in = time_msec() + 2000;
184 : : }
185 : : } else {
186 : 0 : fo->next_bogus_packet_in = LLONG_MAX;
187 : : }
188 : : }
189 : :
190 : 0 : }
191 : :
192 : : /* If 'fo' is currently in fail-open mode and its rconn has connected to the
193 : : * controller, exits fail open mode. */
194 : : void
195 : 0 : fail_open_maybe_recover(struct fail_open *fo)
196 : : OVS_EXCLUDED(ofproto_mutex)
197 : : {
198 [ # # ]: 0 : if (fail_open_is_active(fo)
199 [ # # ]: 0 : && connmgr_is_any_controller_admitted(fo->connmgr)) {
200 : 0 : fail_open_recover(fo);
201 : : }
202 : 0 : }
203 : :
204 : : static void
205 : 0 : fail_open_recover(struct fail_open *fo)
206 : : OVS_EXCLUDED(ofproto_mutex)
207 : : {
208 : : struct match match;
209 : :
210 [ # # ]: 0 : VLOG_WARN("No longer in fail-open mode");
211 : 0 : fo->last_disconn_secs = 0;
212 : 0 : fo->next_bogus_packet_in = LLONG_MAX;
213 : :
214 : 0 : match_init_catchall(&match);
215 : 0 : ofproto_delete_flow(fo->ofproto, &match, FAIL_OPEN_PRIORITY);
216 : 0 : }
217 : :
218 : : void
219 : 0 : fail_open_wait(struct fail_open *fo)
220 : : {
221 [ # # ]: 0 : if (fo->next_bogus_packet_in != LLONG_MAX) {
222 : 0 : poll_timer_wait_until(fo->next_bogus_packet_in);
223 : : }
224 : 0 : }
225 : :
226 : : void
227 : 0 : fail_open_flushed(struct fail_open *fo)
228 : : OVS_EXCLUDED(ofproto_mutex)
229 : : {
230 : 0 : int disconn_secs = connmgr_failure_duration(fo->connmgr);
231 : 0 : bool open = disconn_secs >= trigger_duration(fo);
232 [ # # ]: 0 : if (open) {
233 : : struct ofpbuf ofpacts;
234 : : struct match match;
235 : :
236 : : /* Set up a flow that matches every packet and directs them to
237 : : * OFPP_NORMAL. */
238 : 0 : ofpbuf_init(&ofpacts, OFPACT_OUTPUT_SIZE);
239 : 0 : ofpact_put_OUTPUT(&ofpacts)->port = OFPP_NORMAL;
240 : :
241 : 0 : match_init_catchall(&match);
242 : 0 : ofproto_add_flow(fo->ofproto, &match, FAIL_OPEN_PRIORITY,
243 : 0 : ofpacts.data, ofpacts.size);
244 : :
245 : 0 : ofpbuf_uninit(&ofpacts);
246 : : }
247 : 0 : fo->fail_open_active = open;
248 : 0 : }
249 : :
250 : : /* Returns the number of fail-open rules currently installed in the flow
251 : : * table. */
252 : : int
253 : 0 : fail_open_count_rules(const struct fail_open *fo)
254 : : {
255 : 0 : return fo->fail_open_active != 0;
256 : : }
257 : :
258 : : /* Creates and returns a new struct fail_open for 'ofproto' and 'mgr'. */
259 : : struct fail_open *
260 : 0 : fail_open_create(struct ofproto *ofproto, struct connmgr *mgr)
261 : : {
262 : 0 : struct fail_open *fo = xmalloc(sizeof *fo);
263 : 0 : fo->ofproto = ofproto;
264 : 0 : fo->connmgr = mgr;
265 : 0 : fo->last_disconn_secs = 0;
266 : 0 : fo->next_bogus_packet_in = LLONG_MAX;
267 : 0 : fo->bogus_packet_counter = rconn_packet_counter_create();
268 : 0 : fo->fail_open_active = false;
269 : 0 : return fo;
270 : : }
271 : :
272 : : /* Destroys 'fo'. */
273 : : void
274 : 5594 : fail_open_destroy(struct fail_open *fo)
275 : : OVS_EXCLUDED(ofproto_mutex)
276 : : {
277 [ - + ]: 5594 : if (fo) {
278 [ # # ]: 0 : if (fail_open_is_active(fo)) {
279 : 0 : fail_open_recover(fo);
280 : : }
281 : : /* We don't own fo->connmgr. */
282 : 0 : rconn_packet_counter_destroy(fo->bogus_packet_counter);
283 : 0 : free(fo);
284 : : }
285 : 5594 : }
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