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064af421 | 1 | /* |
e0edde6f | 2 | * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc. |
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" | |
f25d0cf3 | 26 | #include "ofp-actions.h" |
fa37b408 | 27 | #include "ofp-util.h" |
7778bd15 | 28 | #include "ofpbuf.h" |
064af421 | 29 | #include "ofproto.h" |
5bee6e26 | 30 | #include "ofproto-provider.h" |
7778bd15 BP |
31 | #include "pktbuf.h" |
32 | #include "poll-loop.h" | |
064af421 | 33 | #include "rconn.h" |
064af421 | 34 | #include "timeval.h" |
7778bd15 | 35 | #include "vconn.h" |
064af421 BP |
36 | #include "vlog.h" |
37 | ||
d98e6007 | 38 | VLOG_DEFINE_THIS_MODULE(fail_open); |
5136ce49 | 39 | |
7778bd15 BP |
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 | * | |
4a2026dd BP |
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: | |
7778bd15 BP |
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 | ||
064af421 BP |
73 | struct fail_open { |
74 | struct ofproto *ofproto; | |
19a87e36 | 75 | struct connmgr *connmgr; |
064af421 | 76 | int last_disconn_secs; |
7778bd15 BP |
77 | long long int next_bogus_packet_in; |
78 | struct rconn_packet_counter *bogus_packet_counter; | |
064af421 BP |
79 | }; |
80 | ||
2f6d3445 BP |
81 | static void fail_open_recover(struct fail_open *); |
82 | ||
76ce9432 BP |
83 | /* Returns the number of seconds of disconnection after which fail-open mode |
84 | * should activate. */ | |
85 | static int | |
86 | trigger_duration(const struct fail_open *fo) | |
064af421 | 87 | { |
19a87e36 | 88 | if (!connmgr_has_controllers(fo->connmgr)) { |
76ce9432 BP |
89 | /* Shouldn't ever arrive here, but if we do, never fail open. */ |
90 | return INT_MAX; | |
91 | } else { | |
92 | /* Otherwise, every controller must have a chance to send an | |
93 | * inactivity probe and reconnect before we fail open, so take the | |
94 | * maximum probe interval and multiply by 3: | |
95 | * | |
96 | * - The first interval is the idle time before sending an inactivity | |
97 | * probe. | |
98 | * | |
99 | * - The second interval is the time allowed for a response to the | |
100 | * inactivity probe. | |
101 | * | |
102 | * - The third interval is the time allowed to reconnect after no | |
103 | * response is received. | |
104 | */ | |
19a87e36 | 105 | return connmgr_get_max_probe_interval(fo->connmgr) * 3; |
76ce9432 | 106 | } |
7778bd15 BP |
107 | } |
108 | ||
109 | /* Returns true if 'fo' is currently in fail-open mode, otherwise false. */ | |
110 | bool | |
111 | fail_open_is_active(const struct fail_open *fo) | |
112 | { | |
113 | return fo->last_disconn_secs != 0; | |
114 | } | |
064af421 | 115 | |
7778bd15 | 116 | static void |
19a87e36 | 117 | send_bogus_packet_ins(struct fail_open *fo) |
7778bd15 | 118 | { |
0b0517ef | 119 | struct ofputil_packet_in pin; |
7778bd15 | 120 | uint8_t mac[ETH_ADDR_LEN]; |
7778bd15 | 121 | struct ofpbuf b; |
064af421 | 122 | |
7778bd15 | 123 | ofpbuf_init(&b, 128); |
70150daf | 124 | eth_addr_nicira_random(mac); |
2ea838ac | 125 | compose_rarp(&b, mac); |
7778bd15 | 126 | |
0b0517ef BP |
127 | memset(&pin, 0, sizeof pin); |
128 | pin.packet = b.data; | |
129 | pin.packet_len = b.size; | |
130 | pin.reason = OFPR_NO_MATCH; | |
131 | pin.send_len = b.size; | |
132 | pin.fmd.in_port = OFPP_LOCAL; | |
133 | connmgr_send_packet_in(fo->connmgr, &pin); | |
134 | ||
135 | ofpbuf_uninit(&b); | |
7778bd15 BP |
136 | } |
137 | ||
76ce9432 | 138 | /* Enter fail-open mode if we should be in it. */ |
7778bd15 BP |
139 | void |
140 | fail_open_run(struct fail_open *fo) | |
141 | { | |
19a87e36 | 142 | int disconn_secs = connmgr_failure_duration(fo->connmgr); |
76ce9432 | 143 | |
7778bd15 | 144 | /* Enter fail-open mode if 'fo' is not in it but should be. */ |
76ce9432 | 145 | if (disconn_secs >= trigger_duration(fo)) { |
7778bd15 | 146 | if (!fail_open_is_active(fo)) { |
5ec6690c JP |
147 | VLOG_WARN("Could not connect to controller (or switch failed " |
148 | "controller's post-connection admission control " | |
149 | "policy) for %d seconds, failing open", disconn_secs); | |
064af421 BP |
150 | fo->last_disconn_secs = disconn_secs; |
151 | ||
152 | /* Flush all OpenFlow and datapath flows. We will set up our | |
153 | * fail-open rule from fail_open_flushed() when | |
154 | * ofproto_flush_flows() calls back to us. */ | |
155 | ofproto_flush_flows(fo->ofproto); | |
7778bd15 BP |
156 | } else if (disconn_secs > fo->last_disconn_secs + 60) { |
157 | VLOG_INFO("Still in fail-open mode after %d seconds disconnected " | |
158 | "from controller", disconn_secs); | |
159 | fo->last_disconn_secs = disconn_secs; | |
064af421 | 160 | } |
064af421 | 161 | } |
7778bd15 BP |
162 | |
163 | /* Schedule a bogus packet-in if we're connected and in fail-open. */ | |
164 | if (fail_open_is_active(fo)) { | |
19a87e36 | 165 | if (connmgr_is_any_controller_connected(fo->connmgr)) { |
7778bd15 BP |
166 | bool expired = time_msec() >= fo->next_bogus_packet_in; |
167 | if (expired) { | |
76ce9432 | 168 | send_bogus_packet_ins(fo); |
7778bd15 BP |
169 | } |
170 | if (expired || fo->next_bogus_packet_in == LLONG_MAX) { | |
171 | fo->next_bogus_packet_in = time_msec() + 2000; | |
172 | } | |
173 | } else { | |
174 | fo->next_bogus_packet_in = LLONG_MAX; | |
175 | } | |
176 | } | |
177 | ||
064af421 BP |
178 | } |
179 | ||
7778bd15 BP |
180 | /* If 'fo' is currently in fail-open mode and its rconn has connected to the |
181 | * controller, exits fail open mode. */ | |
064af421 | 182 | void |
7778bd15 | 183 | fail_open_maybe_recover(struct fail_open *fo) |
064af421 | 184 | { |
19a87e36 BP |
185 | if (fail_open_is_active(fo) |
186 | && connmgr_is_any_controller_admitted(fo->connmgr)) { | |
2f6d3445 BP |
187 | fail_open_recover(fo); |
188 | } | |
189 | } | |
190 | ||
191 | static void | |
192 | fail_open_recover(struct fail_open *fo) | |
193 | { | |
81a76618 | 194 | struct match match; |
7778bd15 | 195 | |
19a87e36 BP |
196 | VLOG_WARN("No longer in fail-open mode"); |
197 | fo->last_disconn_secs = 0; | |
198 | fo->next_bogus_packet_in = LLONG_MAX; | |
7778bd15 | 199 | |
81a76618 BP |
200 | match_init_catchall(&match); |
201 | ofproto_delete_flow(fo->ofproto, &match, FAIL_OPEN_PRIORITY); | |
7778bd15 BP |
202 | } |
203 | ||
204 | void | |
205 | fail_open_wait(struct fail_open *fo) | |
206 | { | |
207 | if (fo->next_bogus_packet_in != LLONG_MAX) { | |
7cf8b266 | 208 | poll_timer_wait_until(fo->next_bogus_packet_in); |
7778bd15 | 209 | } |
064af421 BP |
210 | } |
211 | ||
212 | void | |
213 | fail_open_flushed(struct fail_open *fo) | |
214 | { | |
19a87e36 | 215 | int disconn_secs = connmgr_failure_duration(fo->connmgr); |
76ce9432 | 216 | bool open = disconn_secs >= trigger_duration(fo); |
064af421 | 217 | if (open) { |
f25d0cf3 | 218 | struct ofpbuf ofpacts; |
81a76618 | 219 | struct match match; |
064af421 BP |
220 | |
221 | /* Set up a flow that matches every packet and directs them to | |
222 | * OFPP_NORMAL. */ | |
f25d0cf3 BP |
223 | ofpbuf_init(&ofpacts, OFPACT_OUTPUT_SIZE); |
224 | ofpact_put_OUTPUT(&ofpacts)->port = OFPP_NORMAL; | |
225 | ofpact_pad(&ofpacts); | |
cf3fad8a | 226 | |
81a76618 BP |
227 | match_init_catchall(&match); |
228 | ofproto_add_flow(fo->ofproto, &match, FAIL_OPEN_PRIORITY, | |
229 | ofpacts.data, ofpacts.size); | |
f25d0cf3 BP |
230 | |
231 | ofpbuf_uninit(&ofpacts); | |
064af421 BP |
232 | } |
233 | } | |
234 | ||
19a87e36 | 235 | /* Creates and returns a new struct fail_open for 'ofproto' and 'mgr'. */ |
064af421 | 236 | struct fail_open * |
19a87e36 | 237 | fail_open_create(struct ofproto *ofproto, struct connmgr *mgr) |
064af421 BP |
238 | { |
239 | struct fail_open *fo = xmalloc(sizeof *fo); | |
240 | fo->ofproto = ofproto; | |
19a87e36 | 241 | fo->connmgr = mgr; |
064af421 | 242 | fo->last_disconn_secs = 0; |
7778bd15 BP |
243 | fo->next_bogus_packet_in = LLONG_MAX; |
244 | fo->bogus_packet_counter = rconn_packet_counter_create(); | |
064af421 BP |
245 | return fo; |
246 | } | |
247 | ||
76ce9432 | 248 | /* Destroys 'fo'. */ |
064af421 BP |
249 | void |
250 | fail_open_destroy(struct fail_open *fo) | |
251 | { | |
252 | if (fo) { | |
19a87e36 BP |
253 | if (fail_open_is_active(fo)) { |
254 | fail_open_recover(fo); | |
255 | } | |
256 | /* We don't own fo->connmgr. */ | |
7778bd15 | 257 | rconn_packet_counter_destroy(fo->bogus_packet_counter); |
064af421 BP |
258 | free(fo); |
259 | } | |
260 | } |