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064af421 | 1 | /* |
9b45d7f5 | 2 | * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks. |
064af421 | 3 | * |
a14bc59f BP |
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: | |
064af421 | 7 | * |
a14bc59f BP |
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. | |
064af421 BP |
15 | */ |
16 | ||
17 | #include <config.h> | |
18 | #include "fail-open.h" | |
19 | #include <inttypes.h> | |
20 | #include <stdlib.h> | |
cf3fad8a | 21 | #include "classifier.h" |
19a87e36 | 22 | #include "connmgr.h" |
064af421 BP |
23 | #include "flow.h" |
24 | #include "mac-learning.h" | |
25 | #include "odp-util.h" | |
fa37b408 | 26 | #include "ofp-util.h" |
7778bd15 | 27 | #include "ofpbuf.h" |
064af421 | 28 | #include "ofproto.h" |
7778bd15 BP |
29 | #include "pktbuf.h" |
30 | #include "poll-loop.h" | |
d08a2e92 | 31 | #include "private.h" |
064af421 | 32 | #include "rconn.h" |
064af421 | 33 | #include "timeval.h" |
7778bd15 | 34 | #include "vconn.h" |
064af421 BP |
35 | #include "vlog.h" |
36 | ||
d98e6007 | 37 | VLOG_DEFINE_THIS_MODULE(fail_open); |
5136ce49 | 38 | |
7778bd15 BP |
39 | /* |
40 | * Fail-open mode. | |
41 | * | |
42 | * In fail-open mode, the switch detects when the controller cannot be | |
43 | * contacted or when the controller is dropping switch connections because the | |
44 | * switch does not pass its admission control policy. In those situations the | |
45 | * switch sets up flows itself using the "normal" action. | |
46 | * | |
47 | * There is a little subtlety to implementation, to properly handle the case | |
48 | * where the controller allows switch connections but drops them a few seconds | |
49 | * later for admission control reasons. Because of this case, we don't want to | |
50 | * just stop setting up flows when we connect to the controller: if we did, | |
51 | * then new flow setup and existing flows would stop during the duration of | |
52 | * connection to the controller, and thus the whole network would go down for | |
53 | * that period of time. | |
54 | * | |
4a2026dd BP |
55 | * So, instead, we add some special cases when we are connected to a |
56 | * controller, but not yet sure that it has admitted us: | |
7778bd15 BP |
57 | * |
58 | * - We set up flows immediately ourselves, but simultaneously send out an | |
59 | * OFPT_PACKET_IN to the controller. We put a special bogus buffer-id in | |
60 | * these OFPT_PACKET_IN messages so that duplicate packets don't get sent | |
61 | * out to the network when the controller replies. | |
62 | * | |
63 | * - We also send out OFPT_PACKET_IN messages for totally bogus packets | |
64 | * every so often, in case no real new flows are arriving in the network. | |
65 | * | |
66 | * - We don't flush the flow table at the time we connect, because this | |
67 | * could cause network stuttering in a switch with lots of flows or very | |
68 | * high-bandwidth flows by suddenly throwing lots of packets down to | |
69 | * userspace. | |
70 | */ | |
71 | ||
064af421 BP |
72 | struct fail_open { |
73 | struct ofproto *ofproto; | |
19a87e36 | 74 | struct connmgr *connmgr; |
064af421 | 75 | int last_disconn_secs; |
7778bd15 BP |
76 | long long int next_bogus_packet_in; |
77 | struct rconn_packet_counter *bogus_packet_counter; | |
064af421 BP |
78 | }; |
79 | ||
2f6d3445 BP |
80 | static void fail_open_recover(struct fail_open *); |
81 | ||
76ce9432 BP |
82 | /* Returns the number of seconds of disconnection after which fail-open mode |
83 | * should activate. */ | |
84 | static int | |
85 | trigger_duration(const struct fail_open *fo) | |
064af421 | 86 | { |
19a87e36 | 87 | if (!connmgr_has_controllers(fo->connmgr)) { |
76ce9432 BP |
88 | /* Shouldn't ever arrive here, but if we do, never fail open. */ |
89 | return INT_MAX; | |
90 | } else { | |
91 | /* Otherwise, every controller must have a chance to send an | |
92 | * inactivity probe and reconnect before we fail open, so take the | |
93 | * maximum probe interval and multiply by 3: | |
94 | * | |
95 | * - The first interval is the idle time before sending an inactivity | |
96 | * probe. | |
97 | * | |
98 | * - The second interval is the time allowed for a response to the | |
99 | * inactivity probe. | |
100 | * | |
101 | * - The third interval is the time allowed to reconnect after no | |
102 | * response is received. | |
103 | */ | |
19a87e36 | 104 | return connmgr_get_max_probe_interval(fo->connmgr) * 3; |
76ce9432 | 105 | } |
7778bd15 BP |
106 | } |
107 | ||
108 | /* Returns true if 'fo' is currently in fail-open mode, otherwise false. */ | |
109 | bool | |
110 | fail_open_is_active(const struct fail_open *fo) | |
111 | { | |
112 | return fo->last_disconn_secs != 0; | |
113 | } | |
064af421 | 114 | |
7778bd15 | 115 | static void |
19a87e36 | 116 | send_bogus_packet_ins(struct fail_open *fo) |
7778bd15 BP |
117 | { |
118 | uint8_t mac[ETH_ADDR_LEN]; | |
119 | struct ofpbuf *opi; | |
120 | struct ofpbuf b; | |
064af421 | 121 | |
7778bd15 BP |
122 | /* Compose ofp_packet_in. */ |
123 | ofpbuf_init(&b, 128); | |
70150daf | 124 | eth_addr_nicira_random(mac); |
7778bd15 BP |
125 | compose_benign_packet(&b, "Open vSwitch Controller Probe", 0xa033, mac); |
126 | opi = make_packet_in(pktbuf_get_null(), OFPP_LOCAL, OFPR_NO_MATCH, &b, 64); | |
127 | ofpbuf_uninit(&b); | |
128 | ||
129 | /* Send. */ | |
19a87e36 | 130 | connmgr_broadcast(fo->connmgr, opi); |
7778bd15 BP |
131 | } |
132 | ||
76ce9432 | 133 | /* Enter fail-open mode if we should be in it. */ |
7778bd15 BP |
134 | void |
135 | fail_open_run(struct fail_open *fo) | |
136 | { | |
19a87e36 | 137 | int disconn_secs = connmgr_failure_duration(fo->connmgr); |
76ce9432 | 138 | |
7778bd15 | 139 | /* Enter fail-open mode if 'fo' is not in it but should be. */ |
76ce9432 | 140 | if (disconn_secs >= trigger_duration(fo)) { |
7778bd15 | 141 | if (!fail_open_is_active(fo)) { |
5ec6690c JP |
142 | VLOG_WARN("Could not connect to controller (or switch failed " |
143 | "controller's post-connection admission control " | |
144 | "policy) for %d seconds, failing open", disconn_secs); | |
064af421 BP |
145 | fo->last_disconn_secs = disconn_secs; |
146 | ||
147 | /* Flush all OpenFlow and datapath flows. We will set up our | |
148 | * fail-open rule from fail_open_flushed() when | |
149 | * ofproto_flush_flows() calls back to us. */ | |
150 | ofproto_flush_flows(fo->ofproto); | |
7778bd15 BP |
151 | } else if (disconn_secs > fo->last_disconn_secs + 60) { |
152 | VLOG_INFO("Still in fail-open mode after %d seconds disconnected " | |
153 | "from controller", disconn_secs); | |
154 | fo->last_disconn_secs = disconn_secs; | |
064af421 | 155 | } |
064af421 | 156 | } |
7778bd15 BP |
157 | |
158 | /* Schedule a bogus packet-in if we're connected and in fail-open. */ | |
159 | if (fail_open_is_active(fo)) { | |
19a87e36 | 160 | if (connmgr_is_any_controller_connected(fo->connmgr)) { |
7778bd15 BP |
161 | bool expired = time_msec() >= fo->next_bogus_packet_in; |
162 | if (expired) { | |
76ce9432 | 163 | send_bogus_packet_ins(fo); |
7778bd15 BP |
164 | } |
165 | if (expired || fo->next_bogus_packet_in == LLONG_MAX) { | |
166 | fo->next_bogus_packet_in = time_msec() + 2000; | |
167 | } | |
168 | } else { | |
169 | fo->next_bogus_packet_in = LLONG_MAX; | |
170 | } | |
171 | } | |
172 | ||
064af421 BP |
173 | } |
174 | ||
7778bd15 BP |
175 | /* If 'fo' is currently in fail-open mode and its rconn has connected to the |
176 | * controller, exits fail open mode. */ | |
064af421 | 177 | void |
7778bd15 | 178 | fail_open_maybe_recover(struct fail_open *fo) |
064af421 | 179 | { |
19a87e36 BP |
180 | if (fail_open_is_active(fo) |
181 | && connmgr_is_any_controller_admitted(fo->connmgr)) { | |
2f6d3445 BP |
182 | fail_open_recover(fo); |
183 | } | |
184 | } | |
185 | ||
186 | static void | |
187 | fail_open_recover(struct fail_open *fo) | |
188 | { | |
19a87e36 | 189 | struct cls_rule rule; |
7778bd15 | 190 | |
19a87e36 BP |
191 | VLOG_WARN("No longer in fail-open mode"); |
192 | fo->last_disconn_secs = 0; | |
193 | fo->next_bogus_packet_in = LLONG_MAX; | |
7778bd15 | 194 | |
19a87e36 BP |
195 | cls_rule_init_catchall(&rule, FAIL_OPEN_PRIORITY); |
196 | ofproto_delete_flow(fo->ofproto, &rule); | |
7778bd15 BP |
197 | } |
198 | ||
199 | void | |
200 | fail_open_wait(struct fail_open *fo) | |
201 | { | |
202 | if (fo->next_bogus_packet_in != LLONG_MAX) { | |
7cf8b266 | 203 | poll_timer_wait_until(fo->next_bogus_packet_in); |
7778bd15 | 204 | } |
064af421 BP |
205 | } |
206 | ||
207 | void | |
208 | fail_open_flushed(struct fail_open *fo) | |
209 | { | |
19a87e36 | 210 | int disconn_secs = connmgr_failure_duration(fo->connmgr); |
76ce9432 | 211 | bool open = disconn_secs >= trigger_duration(fo); |
064af421 BP |
212 | if (open) { |
213 | union ofp_action action; | |
cf3fad8a | 214 | struct cls_rule rule; |
064af421 BP |
215 | |
216 | /* Set up a flow that matches every packet and directs them to | |
217 | * OFPP_NORMAL. */ | |
218 | memset(&action, 0, sizeof action); | |
219 | action.type = htons(OFPAT_OUTPUT); | |
220 | action.output.len = htons(sizeof action); | |
221 | action.output.port = htons(OFPP_NORMAL); | |
cf3fad8a BP |
222 | |
223 | cls_rule_init_catchall(&rule, FAIL_OPEN_PRIORITY); | |
fa8b054f | 224 | ofproto_add_flow(fo->ofproto, &rule, &action, 1); |
064af421 BP |
225 | } |
226 | } | |
227 | ||
19a87e36 | 228 | /* Creates and returns a new struct fail_open for 'ofproto' and 'mgr'. */ |
064af421 | 229 | struct fail_open * |
19a87e36 | 230 | fail_open_create(struct ofproto *ofproto, struct connmgr *mgr) |
064af421 BP |
231 | { |
232 | struct fail_open *fo = xmalloc(sizeof *fo); | |
233 | fo->ofproto = ofproto; | |
19a87e36 | 234 | fo->connmgr = mgr; |
064af421 | 235 | fo->last_disconn_secs = 0; |
7778bd15 BP |
236 | fo->next_bogus_packet_in = LLONG_MAX; |
237 | fo->bogus_packet_counter = rconn_packet_counter_create(); | |
064af421 BP |
238 | return fo; |
239 | } | |
240 | ||
76ce9432 | 241 | /* Destroys 'fo'. */ |
064af421 BP |
242 | void |
243 | fail_open_destroy(struct fail_open *fo) | |
244 | { | |
245 | if (fo) { | |
19a87e36 BP |
246 | if (fail_open_is_active(fo)) { |
247 | fail_open_recover(fo); | |
248 | } | |
249 | /* We don't own fo->connmgr. */ | |
7778bd15 | 250 | rconn_packet_counter_destroy(fo->bogus_packet_counter); |
064af421 BP |
251 | free(fo); |
252 | } | |
253 | } |