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1 | /* | |
2 | * This is an implementation of the IETF SPF delay algorithm | |
3 | * as explained in draft-ietf-rtgwg-backoff-algo-04 | |
4 | * | |
5 | * Created: 25-01-2017 by S. Litkowski | |
6 | * | |
7 | * Copyright (C) 2017 Orange Labs http://www.orange.com/ | |
8 | * Copyright (C) 2017 by Christian Franke, Open Source Routing / NetDEF Inc. | |
9 | * | |
10 | * This file is part of FreeRangeRouting (FRR) | |
11 | * | |
12 | * FRR is free software; you can redistribute it and/or modify it | |
13 | * under the terms of the GNU General Public License as published by the | |
14 | * Free Software Foundation; either version 2, or (at your option) any | |
15 | * later version. | |
16 | * | |
17 | * FRR is distributed in the hope that it will be useful, but | |
18 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
20 | * General Public License for more details. | |
21 | * | |
22 | * You should have received a copy of the GNU General Public License along | |
23 | * with this program; see the file COPYING; if not, write to the Free Software | |
24 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
25 | */ | |
26 | ||
27 | #include <zebra.h> | |
28 | ||
29 | #include "spf_backoff.h" | |
30 | ||
31 | #include "command.h" | |
32 | #include "memory.h" | |
33 | #include "thread.h" | |
34 | #include "vty.h" | |
35 | ||
36 | DEFINE_MTYPE_STATIC(LIB, SPF_BACKOFF, "SPF backoff") | |
37 | DEFINE_MTYPE_STATIC(LIB, SPF_BACKOFF_NAME, "SPF backoff name") | |
38 | ||
39 | static bool debug_spf_backoff = false; | |
40 | #define backoff_debug(...) \ | |
41 | do { \ | |
42 | if (debug_spf_backoff) \ | |
43 | zlog_debug(__VA_ARGS__); \ | |
44 | } while (0) | |
45 | ||
46 | enum spf_backoff_state { | |
47 | SPF_BACKOFF_QUIET, | |
48 | SPF_BACKOFF_SHORT_WAIT, | |
49 | SPF_BACKOFF_LONG_WAIT | |
50 | }; | |
51 | ||
52 | struct spf_backoff { | |
53 | struct thread_master *m; | |
54 | ||
55 | /* Timers as per draft */ | |
56 | long init_delay; | |
57 | long short_delay; | |
58 | long long_delay; | |
59 | long holddown; | |
60 | long timetolearn; | |
61 | ||
62 | /* State machine */ | |
63 | enum spf_backoff_state state; | |
64 | struct thread *t_holddown; | |
65 | struct thread *t_timetolearn; | |
66 | ||
67 | /* For debugging */ | |
68 | char *name; | |
69 | struct timeval first_event_time; | |
70 | struct timeval last_event_time; | |
71 | }; | |
72 | ||
73 | static const char *spf_backoff_state2str(enum spf_backoff_state state) | |
74 | { | |
75 | switch (state) { | |
76 | case SPF_BACKOFF_QUIET: | |
77 | return "QUIET"; | |
78 | case SPF_BACKOFF_SHORT_WAIT: | |
79 | return "SHORT_WAIT"; | |
80 | case SPF_BACKOFF_LONG_WAIT: | |
81 | return "LONG_WAIT"; | |
82 | } | |
83 | return "???"; | |
84 | } | |
85 | ||
86 | struct spf_backoff *spf_backoff_new(struct thread_master *m, const char *name, | |
87 | long init_delay, long short_delay, | |
88 | long long_delay, long holddown, | |
89 | long timetolearn) | |
90 | { | |
91 | struct spf_backoff *rv; | |
92 | ||
93 | rv = XCALLOC(MTYPE_SPF_BACKOFF, sizeof(*rv)); | |
94 | rv->m = m; | |
95 | ||
96 | rv->init_delay = init_delay; | |
97 | rv->short_delay = short_delay; | |
98 | rv->long_delay = long_delay; | |
99 | rv->holddown = holddown; | |
100 | rv->timetolearn = timetolearn; | |
101 | ||
102 | rv->state = SPF_BACKOFF_QUIET; | |
103 | ||
104 | rv->name = XSTRDUP(MTYPE_SPF_BACKOFF_NAME, name); | |
105 | return rv; | |
106 | } | |
107 | ||
108 | void spf_backoff_free(struct spf_backoff *backoff) | |
109 | { | |
110 | if (!backoff) | |
111 | return; | |
112 | ||
113 | THREAD_TIMER_OFF(backoff->t_holddown); | |
114 | THREAD_TIMER_OFF(backoff->t_timetolearn); | |
115 | XFREE(MTYPE_SPF_BACKOFF_NAME, backoff->name); | |
116 | ||
117 | XFREE(MTYPE_SPF_BACKOFF, backoff); | |
118 | } | |
119 | ||
120 | static int spf_backoff_timetolearn_elapsed(struct thread *thread) | |
121 | { | |
122 | struct spf_backoff *backoff = THREAD_ARG(thread); | |
123 | ||
124 | backoff->t_timetolearn = NULL; | |
125 | backoff->state = SPF_BACKOFF_LONG_WAIT; | |
126 | backoff_debug("SPF Back-off(%s) TIMETOLEARN elapsed, move to state %s", | |
127 | backoff->name, spf_backoff_state2str(backoff->state)); | |
128 | return 0; | |
129 | } | |
130 | ||
131 | static int spf_backoff_holddown_elapsed(struct thread *thread) | |
132 | { | |
133 | struct spf_backoff *backoff = THREAD_ARG(thread); | |
134 | ||
135 | backoff->t_holddown = NULL; | |
136 | THREAD_TIMER_OFF(backoff->t_timetolearn); | |
137 | timerclear(&backoff->first_event_time); | |
138 | backoff->state = SPF_BACKOFF_QUIET; | |
139 | backoff_debug("SPF Back-off(%s) HOLDDOWN elapsed, move to state %s", | |
140 | backoff->name, spf_backoff_state2str(backoff->state)); | |
141 | return 0; | |
142 | } | |
143 | ||
144 | long spf_backoff_schedule(struct spf_backoff *backoff) | |
145 | { | |
146 | long rv = 0; | |
147 | struct timeval now; | |
148 | ||
149 | gettimeofday(&now, NULL); | |
150 | ||
151 | backoff_debug("SPF Back-off(%s) schedule called in state %s", | |
152 | backoff->name, spf_backoff_state2str(backoff->state)); | |
153 | ||
154 | backoff->last_event_time = now; | |
155 | ||
156 | switch (backoff->state) { | |
157 | case SPF_BACKOFF_QUIET: | |
158 | backoff->state = SPF_BACKOFF_SHORT_WAIT; | |
159 | thread_add_timer_msec( | |
160 | backoff->m, spf_backoff_timetolearn_elapsed, backoff, | |
161 | backoff->timetolearn, &backoff->t_timetolearn); | |
162 | thread_add_timer_msec(backoff->m, spf_backoff_holddown_elapsed, | |
163 | backoff, backoff->holddown, | |
164 | &backoff->t_holddown); | |
165 | backoff->first_event_time = now; | |
166 | rv = backoff->init_delay; | |
167 | break; | |
168 | case SPF_BACKOFF_SHORT_WAIT: | |
169 | case SPF_BACKOFF_LONG_WAIT: | |
170 | THREAD_TIMER_OFF(backoff->t_holddown); | |
171 | thread_add_timer_msec(backoff->m, spf_backoff_holddown_elapsed, | |
172 | backoff, backoff->holddown, | |
173 | &backoff->t_holddown); | |
174 | if (backoff->state == SPF_BACKOFF_SHORT_WAIT) | |
175 | rv = backoff->short_delay; | |
176 | else | |
177 | rv = backoff->long_delay; | |
178 | break; | |
179 | } | |
180 | ||
181 | backoff_debug( | |
182 | "SPF Back-off(%s) changed state to %s and returned %ld delay", | |
183 | backoff->name, spf_backoff_state2str(backoff->state), rv); | |
184 | return rv; | |
185 | } | |
186 | ||
187 | static const char *timeval_format(struct timeval *tv) | |
188 | { | |
189 | struct tm tm_store; | |
190 | struct tm *tm; | |
191 | static char timebuf[256]; | |
192 | ||
193 | if (!tv->tv_sec && !tv->tv_usec) | |
194 | return "(never)"; | |
195 | ||
196 | tm = localtime_r(&tv->tv_sec, &tm_store); | |
197 | if (!tm | |
198 | || strftime(timebuf, sizeof(timebuf), "%Z %a %Y-%m-%d %H:%M:%S", tm) | |
199 | == 0) { | |
200 | return "???"; | |
201 | } | |
202 | ||
203 | size_t offset = strlen(timebuf); | |
204 | snprintf(timebuf + offset, sizeof(timebuf) - offset, ".%ld", | |
205 | (long int)tv->tv_usec); | |
206 | ||
207 | return timebuf; | |
208 | } | |
209 | ||
210 | void spf_backoff_show(struct spf_backoff *backoff, struct vty *vty, | |
211 | const char *prefix) | |
212 | { | |
213 | vty_out(vty, "%sCurrent state: %s\n", prefix, | |
214 | spf_backoff_state2str(backoff->state)); | |
215 | vty_out(vty, "%sInit timer: %ld msec\n", prefix, | |
216 | backoff->init_delay); | |
217 | vty_out(vty, "%sShort timer: %ld msec\n", prefix, | |
218 | backoff->short_delay); | |
219 | vty_out(vty, "%sLong timer: %ld msec\n", prefix, | |
220 | backoff->long_delay); | |
221 | vty_out(vty, "%sHolddown timer: %ld msec\n", prefix, | |
222 | backoff->holddown); | |
223 | if (backoff->t_holddown) { | |
224 | struct timeval remain = | |
225 | thread_timer_remain(backoff->t_holddown); | |
226 | vty_out(vty, "%s Still runs for %lld msec\n", | |
227 | prefix, | |
228 | (long long)remain.tv_sec * 1000 | |
229 | + remain.tv_usec / 1000); | |
230 | } else { | |
231 | vty_out(vty, "%s Inactive\n", prefix); | |
232 | } | |
233 | ||
234 | vty_out(vty, "%sTimeToLearn timer: %ld msec\n", prefix, | |
235 | backoff->timetolearn); | |
236 | if (backoff->t_timetolearn) { | |
237 | struct timeval remain = | |
238 | thread_timer_remain(backoff->t_timetolearn); | |
239 | vty_out(vty, "%s Still runs for %lld msec\n", | |
240 | prefix, | |
241 | (long long)remain.tv_sec * 1000 | |
242 | + remain.tv_usec / 1000); | |
243 | } else { | |
244 | vty_out(vty, "%s Inactive\n", prefix); | |
245 | } | |
246 | ||
247 | vty_out(vty, "%sFirst event: %s\n", prefix, | |
248 | timeval_format(&backoff->first_event_time)); | |
249 | vty_out(vty, "%sLast event: %s\n", prefix, | |
250 | timeval_format(&backoff->last_event_time)); | |
251 | } | |
252 | ||
253 | DEFUN(spf_backoff_debug, | |
254 | spf_backoff_debug_cmd, | |
255 | "debug spf-delay-ietf", | |
256 | DEBUG_STR | |
257 | "SPF Back-off Debugging\n") | |
258 | { | |
259 | debug_spf_backoff = true; | |
260 | return CMD_SUCCESS; | |
261 | } | |
262 | ||
263 | DEFUN(no_spf_backoff_debug, | |
264 | no_spf_backoff_debug_cmd, | |
265 | "no debug spf-delay-ietf", | |
266 | NO_STR | |
267 | DEBUG_STR | |
268 | "SPF Back-off Debugging\n") | |
269 | { | |
270 | debug_spf_backoff = false; | |
271 | return CMD_SUCCESS; | |
272 | } | |
273 | ||
274 | int spf_backoff_write_config(struct vty *vty) | |
275 | { | |
276 | int written = 0; | |
277 | ||
278 | if (debug_spf_backoff) { | |
279 | vty_out(vty, "debug spf-delay-ietf\n"); | |
280 | written++; | |
281 | } | |
282 | ||
283 | return written; | |
284 | } | |
285 | ||
286 | void spf_backoff_cmd_init(void) | |
287 | { | |
288 | install_element(ENABLE_NODE, &spf_backoff_debug_cmd); | |
289 | install_element(CONFIG_NODE, &spf_backoff_debug_cmd); | |
290 | install_element(ENABLE_NODE, &no_spf_backoff_debug_cmd); | |
291 | install_element(CONFIG_NODE, &no_spf_backoff_debug_cmd); | |
292 | } | |
293 | ||
294 | long spf_backoff_init_delay(struct spf_backoff *backoff) | |
295 | { | |
296 | return backoff->init_delay; | |
297 | } | |
298 | ||
299 | long spf_backoff_short_delay(struct spf_backoff *backoff) | |
300 | { | |
301 | return backoff->short_delay; | |
302 | } | |
303 | ||
304 | long spf_backoff_long_delay(struct spf_backoff *backoff) | |
305 | { | |
306 | return backoff->long_delay; | |
307 | } | |
308 | ||
309 | long spf_backoff_holddown(struct spf_backoff *backoff) | |
310 | { | |
311 | return backoff->holddown; | |
312 | } | |
313 | ||
314 | long spf_backoff_timetolearn(struct spf_backoff *backoff) | |
315 | { | |
316 | return backoff->timetolearn; | |
317 | } |