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eb5d44eb | 1 | /* |
2 | * IS-IS Rout(e)ing protocol - isis_dr.c | |
3 | * IS-IS designated router related routines | |
4 | * | |
5 | * Copyright (C) 2001,2002 Sampo Saaristo | |
6 | * Tampere University of Technology | |
7 | * Institute of Communications Engineering | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify it | |
10 | * under the terms of the GNU General Public Licenseas published by the Free | |
11 | * Software Foundation; either version 2 of the License, or (at your option) | |
12 | * any later version. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful,but WITHOUT | |
15 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
16 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
17 | * more details. | |
18 | ||
19 | * You should have received a copy of the GNU General Public License along | |
20 | * with this program; if not, write to the Free Software Foundation, Inc., | |
21 | * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
22 | */ | |
23 | ||
24 | ||
25 | #include <zebra.h> | |
eb5d44eb | 26 | |
27 | #include "log.h" | |
28 | #include "hash.h" | |
29 | #include "thread.h" | |
30 | #include "linklist.h" | |
31 | #include "vty.h" | |
32 | #include "stream.h" | |
33 | #include "if.h" | |
34 | ||
35 | #include "isisd/dict.h" | |
36 | #include "isisd/isis_constants.h" | |
37 | #include "isisd/isis_common.h" | |
38 | #include "isisd/isis_misc.h" | |
39 | #include "isisd/isis_flags.h" | |
40 | #include "isisd/isis_circuit.h" | |
41 | #include "isisd/isisd.h" | |
42 | #include "isisd/isis_adjacency.h" | |
43 | #include "isisd/isis_constants.h" | |
44 | #include "isisd/isis_pdu.h" | |
45 | #include "isisd/isis_tlv.h" | |
46 | #include "isisd/isis_lsp.h" | |
47 | #include "isisd/isis_dr.h" | |
48 | #include "isisd/isis_events.h" | |
49 | ||
1cd80845 | 50 | const char * |
f390d2c7 | 51 | isis_disflag2string (int disflag) |
52 | { | |
eb5d44eb | 53 | |
f390d2c7 | 54 | switch (disflag) |
55 | { | |
eb5d44eb | 56 | case ISIS_IS_NOT_DIS: |
57 | return "is not DIS"; | |
58 | case ISIS_IS_DIS: | |
59 | return "is DIS"; | |
60 | case ISIS_WAS_DIS: | |
61 | return "was DIS"; | |
f390d2c7 | 62 | default: |
63 | return "unknown DIS state"; | |
64 | } | |
65 | return NULL; /* not reached */ | |
eb5d44eb | 66 | } |
67 | ||
eb5d44eb | 68 | int |
69 | isis_run_dr_l1 (struct thread *thread) | |
70 | { | |
71 | struct isis_circuit *circuit; | |
f390d2c7 | 72 | |
eb5d44eb | 73 | circuit = THREAD_ARG (thread); |
74 | assert (circuit); | |
75 | ||
76 | if (circuit->u.bc.run_dr_elect[0]) | |
77 | zlog_warn ("isis_run_dr(): run_dr_elect already set for l1"); | |
f390d2c7 | 78 | |
efc1e725 | 79 | circuit->u.bc.t_run_dr[0] = NULL; |
eb5d44eb | 80 | circuit->u.bc.run_dr_elect[0] = 1; |
f390d2c7 | 81 | |
eb5d44eb | 82 | return ISIS_OK; |
83 | } | |
84 | ||
85 | int | |
86 | isis_run_dr_l2 (struct thread *thread) | |
87 | { | |
88 | struct isis_circuit *circuit; | |
f390d2c7 | 89 | |
eb5d44eb | 90 | circuit = THREAD_ARG (thread); |
91 | assert (circuit); | |
92 | ||
93 | if (circuit->u.bc.run_dr_elect[1]) | |
94 | zlog_warn ("isis_run_dr(): run_dr_elect already set for l2"); | |
f390d2c7 | 95 | |
96 | ||
97 | circuit->u.bc.t_run_dr[1] = NULL; | |
eb5d44eb | 98 | circuit->u.bc.run_dr_elect[1] = 1; |
f390d2c7 | 99 | |
eb5d44eb | 100 | return ISIS_OK; |
101 | } | |
102 | ||
92365889 | 103 | static int |
eb5d44eb | 104 | isis_check_dr_change (struct isis_adjacency *adj, int level) |
105 | { | |
106 | int i; | |
107 | ||
f390d2c7 | 108 | if (adj->dis_record[level - 1].dis != |
109 | adj->dis_record[(1 * ISIS_LEVELS) + level - 1].dis) | |
110 | /* was there a DIS state transition ? */ | |
eb5d44eb | 111 | { |
f390d2c7 | 112 | adj->dischanges[level - 1]++; |
eb5d44eb | 113 | /* ok rotate the history list through */ |
f390d2c7 | 114 | for (i = DIS_RECORDS - 1; i > 0; i--) |
eb5d44eb | 115 | { |
f390d2c7 | 116 | adj->dis_record[(i * ISIS_LEVELS) + level - 1].dis = |
117 | adj->dis_record[((i - 1) * ISIS_LEVELS) + level - 1].dis; | |
118 | adj->dis_record[(i * ISIS_LEVELS) + level - 1].last_dis_change = | |
119 | adj->dis_record[((i - 1) * ISIS_LEVELS) + level - | |
120 | 1].last_dis_change; | |
eb5d44eb | 121 | } |
122 | } | |
123 | return ISIS_OK; | |
124 | } | |
125 | ||
f390d2c7 | 126 | int |
eb5d44eb | 127 | isis_dr_elect (struct isis_circuit *circuit, int level) |
128 | { | |
129 | struct list *adjdb; | |
3fdb2dd9 | 130 | struct listnode *node; |
eb5d44eb | 131 | struct isis_adjacency *adj, *adj_dr = NULL; |
132 | struct list *list = list_new (); | |
133 | u_char own_prio; | |
134 | int biggest_prio = -1; | |
135 | int cmp_res, retval = ISIS_OK; | |
f390d2c7 | 136 | |
3f045a08 | 137 | own_prio = circuit->priority[level - 1]; |
eb5d44eb | 138 | adjdb = circuit->u.bc.adjdb[level - 1]; |
139 | ||
f390d2c7 | 140 | if (!adjdb) |
141 | { | |
142 | zlog_warn ("isis_dr_elect() adjdb == NULL"); | |
f390d2c7 | 143 | list_delete (list); |
3f045a08 | 144 | return ISIS_WARNING; |
f390d2c7 | 145 | } |
eb5d44eb | 146 | isis_adj_build_up_list (adjdb, list); |
147 | ||
148 | /* | |
149 | * Loop the adjacencies and find the one with the biggest priority | |
150 | */ | |
3fdb2dd9 | 151 | for (ALL_LIST_ELEMENTS_RO (list, node, adj)) |
f390d2c7 | 152 | { |
f390d2c7 | 153 | /* clear flag for show output */ |
154 | adj->dis_record[level - 1].dis = ISIS_IS_NOT_DIS; | |
155 | adj->dis_record[level - 1].last_dis_change = time (NULL); | |
156 | ||
157 | if (adj->prio[level - 1] > biggest_prio) | |
158 | { | |
159 | biggest_prio = adj->prio[level - 1]; | |
160 | adj_dr = adj; | |
161 | } | |
162 | else if (adj->prio[level - 1] == biggest_prio) | |
163 | { | |
164 | /* | |
165 | * Comparison of MACs breaks a tie | |
166 | */ | |
167 | if (adj_dr) | |
168 | { | |
169 | cmp_res = memcmp (adj_dr->snpa, adj->snpa, ETH_ALEN); | |
170 | if (cmp_res < 0) | |
171 | { | |
172 | adj_dr = adj; | |
173 | } | |
174 | if (cmp_res == 0) | |
175 | zlog_warn | |
176 | ("isis_dr_elect(): multiple adjacencies with same SNPA"); | |
177 | } | |
178 | else | |
179 | { | |
180 | adj_dr = adj; | |
181 | } | |
182 | } | |
183 | } | |
184 | ||
185 | if (!adj_dr) | |
186 | { | |
eb5d44eb | 187 | /* |
3f045a08 | 188 | * Could not find the DR - means we are alone. Resign if we were DR. |
eb5d44eb | 189 | */ |
3f045a08 JB |
190 | if (circuit->u.bc.is_dr[level - 1]) |
191 | retval = isis_dr_resign (circuit, level); | |
192 | list_delete (list); | |
193 | return retval; | |
eb5d44eb | 194 | } |
eb5d44eb | 195 | |
196 | /* | |
197 | * Now we have the DR adjacency, compare it to self | |
198 | */ | |
3f045a08 JB |
199 | if (adj_dr->prio[level - 1] < own_prio || |
200 | (adj_dr->prio[level - 1] == own_prio && | |
201 | memcmp (adj_dr->snpa, circuit->u.bc.snpa, ETH_ALEN) < 0)) | |
f390d2c7 | 202 | { |
3f045a08 JB |
203 | adj_dr->dis_record[level - 1].dis = ISIS_IS_NOT_DIS; |
204 | adj_dr->dis_record[level - 1].last_dis_change = time (NULL); | |
d9c427b2 | 205 | |
3f045a08 JB |
206 | /* rotate the history log */ |
207 | for (ALL_LIST_ELEMENTS_RO (list, node, adj)) | |
208 | isis_check_dr_change (adj, level); | |
d9c427b2 | 209 | |
3f045a08 JB |
210 | /* We are the DR, commence DR */ |
211 | if (circuit->u.bc.is_dr[level - 1] == 0 && listcount (list) > 0) | |
212 | retval = isis_dr_commence (circuit, level); | |
eb5d44eb | 213 | } |
f390d2c7 | 214 | else |
215 | { | |
f390d2c7 | 216 | /* ok we have found the DIS - lets mark the adjacency */ |
217 | /* set flag for show output */ | |
218 | adj_dr->dis_record[level - 1].dis = ISIS_IS_DIS; | |
219 | adj_dr->dis_record[level - 1].last_dis_change = time (NULL); | |
eb5d44eb | 220 | |
f390d2c7 | 221 | /* now loop through a second time to check if there has been a DIS change |
222 | * if yes rotate the history log | |
223 | */ | |
eb5d44eb | 224 | |
3fdb2dd9 | 225 | for (ALL_LIST_ELEMENTS_RO (list, node, adj)) |
1eb8ef25 | 226 | isis_check_dr_change (adj, level); |
eb5d44eb | 227 | |
f390d2c7 | 228 | /* |
229 | * We are not DR - if we were -> resign | |
230 | */ | |
f390d2c7 | 231 | if (circuit->u.bc.is_dr[level - 1]) |
3f045a08 | 232 | retval = isis_dr_resign (circuit, level); |
eb5d44eb | 233 | } |
3f045a08 | 234 | list_delete (list); |
eb5d44eb | 235 | return retval; |
236 | } | |
237 | ||
f390d2c7 | 238 | int |
eb5d44eb | 239 | isis_dr_resign (struct isis_circuit *circuit, int level) |
240 | { | |
241 | u_char id[ISIS_SYS_ID_LEN + 2]; | |
f390d2c7 | 242 | |
529d65b3 | 243 | zlog_debug ("isis_dr_resign l%d", level); |
eb5d44eb | 244 | |
245 | circuit->u.bc.is_dr[level - 1] = 0; | |
f390d2c7 | 246 | circuit->u.bc.run_dr_elect[level - 1] = 0; |
247 | THREAD_TIMER_OFF (circuit->u.bc.t_run_dr[level - 1]); | |
248 | THREAD_TIMER_OFF (circuit->u.bc.t_refresh_pseudo_lsp[level - 1]); | |
3f045a08 | 249 | circuit->lsp_regenerate_pending[level - 1] = 0; |
f390d2c7 | 250 | |
eb5d44eb | 251 | memcpy (id, isis->sysid, ISIS_SYS_ID_LEN); |
f390d2c7 | 252 | LSP_PSEUDO_ID (id) = circuit->circuit_id; |
253 | LSP_FRAGMENT (id) = 0; | |
3f045a08 | 254 | lsp_purge_pseudo (id, circuit, level); |
eb5d44eb | 255 | |
f390d2c7 | 256 | if (level == 1) |
257 | { | |
258 | memset (circuit->u.bc.l1_desig_is, 0, ISIS_SYS_ID_LEN + 1); | |
259 | ||
260 | THREAD_TIMER_OFF (circuit->t_send_csnp[0]); | |
261 | ||
262 | THREAD_TIMER_ON (master, circuit->u.bc.t_run_dr[0], isis_run_dr_l1, | |
e7fe02fd | 263 | circuit, 2 * circuit->hello_interval[0]); |
f390d2c7 | 264 | |
265 | THREAD_TIMER_ON (master, circuit->t_send_psnp[0], send_l1_psnp, circuit, | |
266 | isis_jitter (circuit->psnp_interval[level - 1], | |
267 | PSNP_JITTER)); | |
268 | } | |
269 | else | |
270 | { | |
271 | memset (circuit->u.bc.l2_desig_is, 0, ISIS_SYS_ID_LEN + 1); | |
272 | ||
273 | THREAD_TIMER_OFF (circuit->t_send_csnp[1]); | |
274 | ||
275 | THREAD_TIMER_ON (master, circuit->u.bc.t_run_dr[1], isis_run_dr_l2, | |
276 | circuit, 2 * circuit->hello_interval[1]); | |
277 | ||
278 | THREAD_TIMER_ON (master, circuit->t_send_psnp[1], send_l2_psnp, circuit, | |
279 | isis_jitter (circuit->psnp_interval[level - 1], | |
280 | PSNP_JITTER)); | |
281 | } | |
282 | ||
eb5d44eb | 283 | thread_add_event (master, isis_event_dis_status_change, circuit, 0); |
284 | ||
285 | return ISIS_OK; | |
286 | } | |
287 | ||
f390d2c7 | 288 | int |
eb5d44eb | 289 | isis_dr_commence (struct isis_circuit *circuit, int level) |
290 | { | |
291 | u_char old_dr[ISIS_SYS_ID_LEN + 2]; | |
f390d2c7 | 292 | |
c89c05dd | 293 | if (isis->debugs & DEBUG_EVENTS) |
294 | zlog_debug ("isis_dr_commence l%d", level); | |
eb5d44eb | 295 | |
296 | /* Lets keep a pause in DR election */ | |
297 | circuit->u.bc.run_dr_elect[level - 1] = 0; | |
f390d2c7 | 298 | if (level == 1) |
299 | THREAD_TIMER_ON (master, circuit->u.bc.t_run_dr[0], isis_run_dr_l1, | |
a211d65d | 300 | circuit, 2 * circuit->hello_interval[0]); |
f390d2c7 | 301 | else |
302 | THREAD_TIMER_ON (master, circuit->u.bc.t_run_dr[1], isis_run_dr_l2, | |
a211d65d | 303 | circuit, 2 * circuit->hello_interval[1]); |
eb5d44eb | 304 | circuit->u.bc.is_dr[level - 1] = 1; |
305 | ||
f390d2c7 | 306 | if (level == 1) |
307 | { | |
308 | memcpy (old_dr, circuit->u.bc.l1_desig_is, ISIS_SYS_ID_LEN + 1); | |
309 | LSP_FRAGMENT (old_dr) = 0; | |
310 | if (LSP_PSEUDO_ID (old_dr)) | |
311 | { | |
312 | /* there was a dr elected, purge its LSPs from the db */ | |
3f045a08 | 313 | lsp_purge_pseudo (old_dr, circuit, level); |
f390d2c7 | 314 | } |
315 | memcpy (circuit->u.bc.l1_desig_is, isis->sysid, ISIS_SYS_ID_LEN); | |
316 | *(circuit->u.bc.l1_desig_is + ISIS_SYS_ID_LEN) = circuit->circuit_id; | |
317 | ||
318 | assert (circuit->circuit_id); /* must be non-zero */ | |
319 | /* if (circuit->t_send_l1_psnp) | |
320 | thread_cancel (circuit->t_send_l1_psnp); */ | |
3f045a08 | 321 | lsp_generate_pseudo (circuit, 1); |
f390d2c7 | 322 | |
323 | THREAD_TIMER_OFF (circuit->u.bc.t_run_dr[0]); | |
324 | THREAD_TIMER_ON (master, circuit->u.bc.t_run_dr[0], isis_run_dr_l1, | |
325 | circuit, 2 * circuit->hello_interval[0]); | |
326 | ||
327 | THREAD_TIMER_ON (master, circuit->t_send_csnp[0], send_l1_csnp, circuit, | |
328 | isis_jitter (circuit->csnp_interval[level - 1], | |
329 | CSNP_JITTER)); | |
330 | ||
eb5d44eb | 331 | } |
f390d2c7 | 332 | else |
333 | { | |
334 | memcpy (old_dr, circuit->u.bc.l2_desig_is, ISIS_SYS_ID_LEN + 1); | |
335 | LSP_FRAGMENT (old_dr) = 0; | |
336 | if (LSP_PSEUDO_ID (old_dr)) | |
337 | { | |
338 | /* there was a dr elected, purge its LSPs from the db */ | |
3f045a08 | 339 | lsp_purge_pseudo (old_dr, circuit, level); |
f390d2c7 | 340 | } |
341 | memcpy (circuit->u.bc.l2_desig_is, isis->sysid, ISIS_SYS_ID_LEN); | |
342 | *(circuit->u.bc.l2_desig_is + ISIS_SYS_ID_LEN) = circuit->circuit_id; | |
343 | ||
344 | assert (circuit->circuit_id); /* must be non-zero */ | |
345 | /* if (circuit->t_send_l1_psnp) | |
346 | thread_cancel (circuit->t_send_l1_psnp); */ | |
3f045a08 | 347 | lsp_generate_pseudo (circuit, 2); |
f390d2c7 | 348 | |
349 | THREAD_TIMER_OFF (circuit->u.bc.t_run_dr[1]); | |
350 | THREAD_TIMER_ON (master, circuit->u.bc.t_run_dr[1], isis_run_dr_l2, | |
351 | circuit, 2 * circuit->hello_interval[1]); | |
352 | ||
353 | THREAD_TIMER_ON (master, circuit->t_send_csnp[1], send_l2_csnp, circuit, | |
354 | isis_jitter (circuit->csnp_interval[level - 1], | |
355 | CSNP_JITTER)); | |
eb5d44eb | 356 | } |
eb5d44eb | 357 | |
358 | thread_add_event (master, isis_event_dis_status_change, circuit, 0); | |
f390d2c7 | 359 | |
eb5d44eb | 360 | return ISIS_OK; |
361 | } |