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eb5d44eb | 1 | /* |
2 | * IS-IS Rout(e)ing protocol - isis_dr.c | |
d62a17ae | 3 | * IS-IS designated router related routines |
eb5d44eb | 4 | * |
5 | * Copyright (C) 2001,2002 Sampo Saaristo | |
d62a17ae | 6 | * Tampere University of Technology |
eb5d44eb | 7 | * Institute of Communications Engineering |
8 | * | |
d62a17ae | 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) | |
eb5d44eb | 12 | * any later version. |
13 | * | |
d62a17ae | 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 | |
eb5d44eb | 17 | * more details. |
896014f4 DL |
18 | * |
19 | * You should have received a copy of the GNU General Public License along | |
20 | * with this program; see the file COPYING; if not, write to the Free Software | |
21 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
eb5d44eb | 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 | ||
eb5d44eb | 35 | #include "isisd/isis_constants.h" |
36 | #include "isisd/isis_common.h" | |
37 | #include "isisd/isis_misc.h" | |
38 | #include "isisd/isis_flags.h" | |
39 | #include "isisd/isis_circuit.h" | |
40 | #include "isisd/isisd.h" | |
41 | #include "isisd/isis_adjacency.h" | |
42 | #include "isisd/isis_constants.h" | |
43 | #include "isisd/isis_pdu.h" | |
eb5d44eb | 44 | #include "isisd/isis_lsp.h" |
45 | #include "isisd/isis_dr.h" | |
46 | #include "isisd/isis_events.h" | |
47 | ||
d62a17ae | 48 | const char *isis_disflag2string(int disflag) |
f390d2c7 | 49 | { |
eb5d44eb | 50 | |
d62a17ae | 51 | switch (disflag) { |
52 | case ISIS_IS_NOT_DIS: | |
53 | return "is not DIS"; | |
54 | case ISIS_IS_DIS: | |
55 | return "is DIS"; | |
56 | case ISIS_WAS_DIS: | |
57 | return "was DIS"; | |
58 | default: | |
59 | return "unknown DIS state"; | |
60 | } | |
61 | return NULL; /* not reached */ | |
eb5d44eb | 62 | } |
63 | ||
7c4f7aab | 64 | int isis_run_dr(struct thread *thread) |
eb5d44eb | 65 | { |
7c4f7aab | 66 | struct isis_circuit_arg *arg = THREAD_ARG(thread); |
f390d2c7 | 67 | |
7c4f7aab | 68 | assert(arg); |
f390d2c7 | 69 | |
7c4f7aab CF |
70 | struct isis_circuit *circuit = arg->circuit; |
71 | int level = arg->level; | |
eb5d44eb | 72 | |
d62a17ae | 73 | assert(circuit); |
eb5d44eb | 74 | |
7c4f7aab CF |
75 | if (circuit->circ_type != CIRCUIT_T_BROADCAST) { |
76 | zlog_warn("%s: scheduled for non broadcast circuit from %s:%d", | |
77 | __func__, thread->schedfrom, thread->schedfrom_line); | |
78 | return ISIS_WARNING; | |
79 | } | |
f390d2c7 | 80 | |
7c4f7aab CF |
81 | if (circuit->u.bc.run_dr_elect[level - 1]) |
82 | zlog_warn("isis_run_dr(): run_dr_elect already set for l%d", level); | |
f390d2c7 | 83 | |
7c4f7aab CF |
84 | circuit->u.bc.t_run_dr[level - 1] = NULL; |
85 | circuit->u.bc.run_dr_elect[level - 1] = 1; | |
f390d2c7 | 86 | |
d62a17ae | 87 | return ISIS_OK; |
eb5d44eb | 88 | } |
89 | ||
d62a17ae | 90 | static int isis_check_dr_change(struct isis_adjacency *adj, int level) |
eb5d44eb | 91 | { |
d62a17ae | 92 | int i; |
93 | ||
94 | if (adj->dis_record[level - 1].dis | |
95 | != adj->dis_record[(1 * ISIS_LEVELS) + level - 1].dis) | |
96 | /* was there a DIS state transition ? */ | |
eb5d44eb | 97 | { |
d62a17ae | 98 | adj->dischanges[level - 1]++; |
99 | /* ok rotate the history list through */ | |
100 | for (i = DIS_RECORDS - 1; i > 0; i--) { | |
101 | adj->dis_record[(i * ISIS_LEVELS) + level - 1].dis = | |
102 | adj->dis_record[((i - 1) * ISIS_LEVELS) + level | |
103 | - 1] | |
104 | .dis; | |
105 | adj->dis_record[(i * ISIS_LEVELS) + level - 1] | |
106 | .last_dis_change = | |
107 | adj->dis_record[((i - 1) * ISIS_LEVELS) + level | |
108 | - 1] | |
109 | .last_dis_change; | |
110 | } | |
eb5d44eb | 111 | } |
d62a17ae | 112 | return ISIS_OK; |
eb5d44eb | 113 | } |
114 | ||
d62a17ae | 115 | int isis_dr_elect(struct isis_circuit *circuit, int level) |
eb5d44eb | 116 | { |
d62a17ae | 117 | struct list *adjdb; |
118 | struct listnode *node; | |
119 | struct isis_adjacency *adj, *adj_dr = NULL; | |
120 | struct list *list = list_new(); | |
d7c0a89a | 121 | uint8_t own_prio; |
d62a17ae | 122 | int biggest_prio = -1; |
123 | int cmp_res, retval = ISIS_OK; | |
124 | ||
125 | own_prio = circuit->priority[level - 1]; | |
126 | adjdb = circuit->u.bc.adjdb[level - 1]; | |
127 | ||
128 | if (!adjdb) { | |
129 | zlog_warn("isis_dr_elect() adjdb == NULL"); | |
6a154c88 | 130 | list_delete(&list); |
d62a17ae | 131 | return ISIS_WARNING; |
f390d2c7 | 132 | } |
d62a17ae | 133 | isis_adj_build_up_list(adjdb, list); |
134 | ||
135 | /* | |
136 | * Loop the adjacencies and find the one with the biggest priority | |
137 | */ | |
138 | for (ALL_LIST_ELEMENTS_RO(list, node, adj)) { | |
139 | /* clear flag for show output */ | |
140 | adj->dis_record[level - 1].dis = ISIS_IS_NOT_DIS; | |
141 | adj->dis_record[level - 1].last_dis_change = time(NULL); | |
142 | ||
143 | if (adj->prio[level - 1] > biggest_prio) { | |
144 | biggest_prio = adj->prio[level - 1]; | |
145 | adj_dr = adj; | |
146 | } else if (adj->prio[level - 1] == biggest_prio) { | |
147 | /* | |
148 | * Comparison of MACs breaks a tie | |
149 | */ | |
150 | if (adj_dr) { | |
151 | cmp_res = memcmp(adj_dr->snpa, adj->snpa, | |
152 | ETH_ALEN); | |
153 | if (cmp_res < 0) { | |
154 | adj_dr = adj; | |
155 | } | |
156 | if (cmp_res == 0) | |
157 | zlog_warn( | |
158 | "isis_dr_elect(): multiple adjacencies with same SNPA"); | |
159 | } else { | |
160 | adj_dr = adj; | |
161 | } | |
f390d2c7 | 162 | } |
f390d2c7 | 163 | } |
d62a17ae | 164 | |
165 | if (!adj_dr) { | |
166 | /* | |
167 | * Could not find the DR - means we are alone. Resign if we were | |
168 | * DR. | |
169 | */ | |
170 | if (circuit->u.bc.is_dr[level - 1]) | |
171 | retval = isis_dr_resign(circuit, level); | |
6a154c88 | 172 | list_delete(&list); |
d62a17ae | 173 | return retval; |
174 | } | |
175 | ||
176 | /* | |
177 | * Now we have the DR adjacency, compare it to self | |
178 | */ | |
179 | if (adj_dr->prio[level - 1] < own_prio | |
180 | || (adj_dr->prio[level - 1] == own_prio | |
181 | && memcmp(adj_dr->snpa, circuit->u.bc.snpa, ETH_ALEN) < 0)) { | |
182 | adj_dr->dis_record[level - 1].dis = ISIS_IS_NOT_DIS; | |
183 | adj_dr->dis_record[level - 1].last_dis_change = time(NULL); | |
184 | ||
185 | /* rotate the history log */ | |
186 | for (ALL_LIST_ELEMENTS_RO(list, node, adj)) | |
187 | isis_check_dr_change(adj, level); | |
188 | ||
189 | /* We are the DR, commence DR */ | |
190 | if (circuit->u.bc.is_dr[level - 1] == 0 && listcount(list) > 0) | |
191 | retval = isis_dr_commence(circuit, level); | |
192 | } else { | |
193 | /* ok we have found the DIS - lets mark the adjacency */ | |
194 | /* set flag for show output */ | |
195 | adj_dr->dis_record[level - 1].dis = ISIS_IS_DIS; | |
196 | adj_dr->dis_record[level - 1].last_dis_change = time(NULL); | |
197 | ||
198 | /* now loop through a second time to check if there has been a | |
199 | * DIS change | |
200 | * if yes rotate the history log | |
201 | */ | |
202 | ||
203 | for (ALL_LIST_ELEMENTS_RO(list, node, adj)) | |
204 | isis_check_dr_change(adj, level); | |
205 | ||
206 | /* | |
207 | * We are not DR - if we were -> resign | |
208 | */ | |
209 | if (circuit->u.bc.is_dr[level - 1]) | |
210 | retval = isis_dr_resign(circuit, level); | |
211 | } | |
6a154c88 | 212 | list_delete(&list); |
d62a17ae | 213 | return retval; |
eb5d44eb | 214 | } |
215 | ||
d62a17ae | 216 | int isis_dr_resign(struct isis_circuit *circuit, int level) |
eb5d44eb | 217 | { |
d7c0a89a | 218 | uint8_t id[ISIS_SYS_ID_LEN + 2]; |
f390d2c7 | 219 | |
d62a17ae | 220 | zlog_debug("isis_dr_resign l%d", level); |
eb5d44eb | 221 | |
d62a17ae | 222 | circuit->u.bc.is_dr[level - 1] = 0; |
223 | circuit->u.bc.run_dr_elect[level - 1] = 0; | |
50478845 MS |
224 | thread_cancel(&circuit->u.bc.t_run_dr[level - 1]); |
225 | thread_cancel(&circuit->u.bc.t_refresh_pseudo_lsp[level - 1]); | |
d62a17ae | 226 | circuit->lsp_regenerate_pending[level - 1] = 0; |
f390d2c7 | 227 | |
99e5d4af | 228 | memcpy(id, circuit->isis->sysid, ISIS_SYS_ID_LEN); |
d62a17ae | 229 | LSP_PSEUDO_ID(id) = circuit->circuit_id; |
230 | LSP_FRAGMENT(id) = 0; | |
231 | lsp_purge_pseudo(id, circuit, level); | |
eb5d44eb | 232 | |
d62a17ae | 233 | if (level == 1) { |
234 | memset(circuit->u.bc.l1_desig_is, 0, ISIS_SYS_ID_LEN + 1); | |
f390d2c7 | 235 | |
d62a17ae | 236 | thread_add_timer(master, send_l1_psnp, circuit, |
237 | isis_jitter(circuit->psnp_interval[level - 1], | |
238 | PSNP_JITTER), | |
239 | &circuit->t_send_psnp[0]); | |
240 | } else { | |
241 | memset(circuit->u.bc.l2_desig_is, 0, ISIS_SYS_ID_LEN + 1); | |
f390d2c7 | 242 | |
d62a17ae | 243 | thread_add_timer(master, send_l2_psnp, circuit, |
244 | isis_jitter(circuit->psnp_interval[level - 1], | |
245 | PSNP_JITTER), | |
246 | &circuit->t_send_psnp[1]); | |
247 | } | |
f390d2c7 | 248 | |
50478845 | 249 | thread_cancel(&circuit->t_send_csnp[level - 1]); |
7c4f7aab CF |
250 | |
251 | thread_add_timer(master, isis_run_dr, | |
252 | &circuit->level_arg[level - 1], | |
253 | 2 * circuit->hello_interval[level - 1], | |
254 | &circuit->u.bc.t_run_dr[level - 1]); | |
255 | ||
256 | ||
d62a17ae | 257 | thread_add_event(master, isis_event_dis_status_change, circuit, 0, |
258 | NULL); | |
eb5d44eb | 259 | |
d62a17ae | 260 | return ISIS_OK; |
eb5d44eb | 261 | } |
262 | ||
d62a17ae | 263 | int isis_dr_commence(struct isis_circuit *circuit, int level) |
eb5d44eb | 264 | { |
d7c0a89a | 265 | uint8_t old_dr[ISIS_SYS_ID_LEN + 2]; |
d62a17ae | 266 | |
e740f9c1 | 267 | if (IS_DEBUG_EVENTS) |
d62a17ae | 268 | zlog_debug("isis_dr_commence l%d", level); |
269 | ||
270 | /* Lets keep a pause in DR election */ | |
271 | circuit->u.bc.run_dr_elect[level - 1] = 0; | |
d62a17ae | 272 | circuit->u.bc.is_dr[level - 1] = 1; |
273 | ||
274 | if (level == 1) { | |
275 | memcpy(old_dr, circuit->u.bc.l1_desig_is, ISIS_SYS_ID_LEN + 1); | |
276 | LSP_FRAGMENT(old_dr) = 0; | |
277 | if (LSP_PSEUDO_ID(old_dr)) { | |
278 | /* there was a dr elected, purge its LSPs from the db */ | |
279 | lsp_purge_pseudo(old_dr, circuit, level); | |
280 | } | |
99e5d4af | 281 | memcpy(circuit->u.bc.l1_desig_is, circuit->isis->sysid, |
eab88f36 | 282 | ISIS_SYS_ID_LEN); |
d62a17ae | 283 | *(circuit->u.bc.l1_desig_is + ISIS_SYS_ID_LEN) = |
284 | circuit->circuit_id; | |
285 | ||
286 | assert(circuit->circuit_id); /* must be non-zero */ | |
287 | /* if (circuit->t_send_l1_psnp) | |
288 | thread_cancel (circuit->t_send_l1_psnp); */ | |
289 | lsp_generate_pseudo(circuit, 1); | |
290 | ||
d62a17ae | 291 | thread_add_timer(master, send_l1_csnp, circuit, |
292 | isis_jitter(circuit->csnp_interval[level - 1], | |
293 | CSNP_JITTER), | |
294 | &circuit->t_send_csnp[0]); | |
295 | ||
296 | } else { | |
297 | memcpy(old_dr, circuit->u.bc.l2_desig_is, ISIS_SYS_ID_LEN + 1); | |
298 | LSP_FRAGMENT(old_dr) = 0; | |
299 | if (LSP_PSEUDO_ID(old_dr)) { | |
300 | /* there was a dr elected, purge its LSPs from the db */ | |
301 | lsp_purge_pseudo(old_dr, circuit, level); | |
302 | } | |
99e5d4af | 303 | memcpy(circuit->u.bc.l2_desig_is, circuit->isis->sysid, |
eab88f36 | 304 | ISIS_SYS_ID_LEN); |
d62a17ae | 305 | *(circuit->u.bc.l2_desig_is + ISIS_SYS_ID_LEN) = |
306 | circuit->circuit_id; | |
307 | ||
308 | assert(circuit->circuit_id); /* must be non-zero */ | |
309 | /* if (circuit->t_send_l1_psnp) | |
310 | thread_cancel (circuit->t_send_l1_psnp); */ | |
311 | lsp_generate_pseudo(circuit, 2); | |
312 | ||
d62a17ae | 313 | thread_add_timer(master, send_l2_csnp, circuit, |
314 | isis_jitter(circuit->csnp_interval[level - 1], | |
315 | CSNP_JITTER), | |
316 | &circuit->t_send_csnp[1]); | |
f390d2c7 | 317 | } |
eb5d44eb | 318 | |
0a5e562a CF |
319 | thread_add_timer(master, isis_run_dr, |
320 | &circuit->level_arg[level - 1], | |
321 | 2 * circuit->hello_interval[level - 1], | |
322 | &circuit->u.bc.t_run_dr[level - 1]); | |
d62a17ae | 323 | thread_add_event(master, isis_event_dis_status_change, circuit, 0, |
324 | NULL); | |
f390d2c7 | 325 | |
d62a17ae | 326 | return ISIS_OK; |
eb5d44eb | 327 | } |