]>
Commit | Line | Data |
---|---|---|
31b3e1bb MM |
1 | /* |
2 | * BIRD Internet Routing Daemon -- Configuration File Handling | |
3 | * | |
50fe90ed | 4 | * (c) 1998--2000 Martin Mares <mj@ucw.cz> |
31b3e1bb MM |
5 | * |
6 | * Can be freely distributed and used under the terms of the GNU GPL. | |
7 | */ | |
8 | ||
06607335 MM |
9 | /** |
10 | * DOC: Configuration manager | |
11 | * | |
725270cb | 12 | * Configuration of BIRD is complex, yet straightforward. There are three |
06607335 | 13 | * modules taking care of the configuration: config manager (which takes care |
58f7d004 | 14 | * of storage of the config information and controls switching between configs), |
2e9b2421 | 15 | * lexical analyzer and parser. |
06607335 MM |
16 | * |
17 | * The configuration manager stores each config as a &config structure | |
18 | * accompanied by a linear pool from which all information associated | |
19 | * with the config and pointed to by the &config structure is allocated. | |
20 | * | |
725270cb | 21 | * There can exist up to four different configurations at one time: an active |
06607335 MM |
22 | * one (pointed to by @config), configuration we are just switching from |
23 | * (@old_config), one queued for the next reconfiguration (@future_config; | |
24 | * if it's non-%NULL and the user wants to reconfigure once again, we just | |
25 | * free the previous queued config and replace it with the new one) and | |
26 | * finally a config being parsed (@new_config). | |
27 | * | |
28 | * Loading of new configuration is very simple: just call config_alloc() | |
29 | * to get a new &config structure, then use config_parse() to parse a | |
58f7d004 | 30 | * configuration file and fill all fields of the structure |
06607335 MM |
31 | * and finally ask the config manager to switch to the new |
32 | * config by calling config_commit(). | |
33 | * | |
34 | * CLI commands are parsed in a very similar way -- there is also a stripped-down | |
2e9b2421 | 35 | * &config structure associated with them and they are lex-ed and parsed by the |
06607335 MM |
36 | * same functions, only a special fake token is prepended before the command |
37 | * text to make the parser recognize only the rules corresponding to CLI commands. | |
38 | */ | |
39 | ||
31b3e1bb MM |
40 | #include <setjmp.h> |
41 | #include <stdarg.h> | |
42 | ||
6b9fa320 | 43 | #undef LOCAL_DEBUG |
50fe90ed | 44 | |
31b3e1bb | 45 | #include "nest/bird.h" |
0e02abfd | 46 | #include "nest/route.h" |
31b3e1bb MM |
47 | #include "nest/protocol.h" |
48 | #include "nest/iface.h" | |
49 | #include "lib/resource.h" | |
50 | #include "lib/string.h" | |
50fe90ed | 51 | #include "lib/event.h" |
43270902 | 52 | #include "lib/timer.h" |
31b3e1bb MM |
53 | #include "conf/conf.h" |
54 | #include "filter/filter.h" | |
55 | ||
56 | static jmp_buf conf_jmpbuf; | |
57 | ||
50fe90ed MM |
58 | struct config *config, *new_config, *old_config, *future_config; |
59 | static event *config_event; | |
bf8558bc | 60 | int shutting_down; |
43270902 | 61 | bird_clock_t boot_time; |
31b3e1bb | 62 | |
06607335 MM |
63 | /** |
64 | * config_alloc - allocate a new configuration | |
65 | * @name: name of the config | |
66 | * | |
67 | * This function creates new &config structure, attaches a resource | |
68 | * pool and a linear memory pool to it and makes it available for | |
69 | * further use. Returns a pointer to the structure. | |
70 | */ | |
31b3e1bb MM |
71 | struct config * |
72 | config_alloc(byte *name) | |
73 | { | |
74 | pool *p = rp_new(&root_pool, "Config"); | |
d4ff7482 | 75 | linpool *l = lp_new(p, 4080); |
31b3e1bb MM |
76 | struct config *c = lp_allocz(l, sizeof(struct config)); |
77 | ||
78 | c->pool = p; | |
79 | cfg_mem = c->mem = l; | |
31b3e1bb | 80 | c->file_name = cfg_strdup(name); |
43270902 MM |
81 | c->load_time = now; |
82 | if (!boot_time) | |
83 | boot_time = now; | |
31b3e1bb MM |
84 | return c; |
85 | } | |
86 | ||
06607335 MM |
87 | /** |
88 | * config_parse - parse a configuration | |
89 | * @c: configuration | |
90 | * | |
91 | * config_parse() reads input by calling a hook function pointed to | |
92 | * by @cf_read_hook and parses it according to the configuration | |
93 | * grammar. It also calls all the preconfig and postconfig hooks | |
2e9b2421 | 94 | * before, resp. after parsing. |
06607335 MM |
95 | * |
96 | * Result: 1 if the config has been parsed successfully, 0 if any | |
2e9b2421 | 97 | * error has occurred (such as anybody calling cf_error()) and |
06607335 MM |
98 | * the @err_msg field has been set to the error message. |
99 | */ | |
31b3e1bb MM |
100 | int |
101 | config_parse(struct config *c) | |
102 | { | |
f30b86f9 | 103 | DBG("Parsing configuration file `%s'\n", c->file_name); |
31b3e1bb | 104 | new_config = c; |
31b3e1bb MM |
105 | cfg_mem = c->mem; |
106 | if (setjmp(conf_jmpbuf)) | |
107 | return 0; | |
bc2fb680 | 108 | cf_lex_init(0); |
7c0cc76e | 109 | sysdep_preconfig(c); |
31b3e1bb | 110 | protos_preconfig(c); |
0e02abfd | 111 | rt_preconfig(c); |
31b3e1bb | 112 | cf_parse(); |
31b3e1bb | 113 | protos_postconfig(c); |
dce26783 MM |
114 | #ifdef IPV6 |
115 | if (!c->router_id) | |
116 | cf_error("Router ID must be configured manually on IPv6 routers"); | |
117 | #endif | |
31b3e1bb MM |
118 | return 1; |
119 | } | |
120 | ||
06607335 MM |
121 | /** |
122 | * cli_parse - parse a CLI command | |
123 | * @c: temporary config structure | |
124 | * | |
125 | * cli_parse() is similar to config_parse(), but instead of a configuration, | |
126 | * it parses a CLI command. See the CLI module for more information. | |
127 | */ | |
bc2fb680 MM |
128 | int |
129 | cli_parse(struct config *c) | |
130 | { | |
131 | new_config = c; | |
c9aae7f4 | 132 | c->sym_fallback = config->sym_hash; |
bc2fb680 MM |
133 | cfg_mem = c->mem; |
134 | if (setjmp(conf_jmpbuf)) | |
135 | return 0; | |
136 | cf_lex_init(1); | |
137 | cf_parse(); | |
138 | return 1; | |
139 | } | |
140 | ||
06607335 MM |
141 | /** |
142 | * config_free - free a configuration | |
143 | * @c: configuration to be freed | |
144 | * | |
145 | * This function takes a &config structure and frees all resources | |
146 | * associated with it. | |
147 | */ | |
31b3e1bb MM |
148 | void |
149 | config_free(struct config *c) | |
150 | { | |
151 | rfree(c->pool); | |
152 | } | |
153 | ||
154 | void | |
50fe90ed MM |
155 | config_add_obstacle(struct config *c) |
156 | { | |
157 | DBG("+++ adding obstacle %d\n", c->obstacle_count); | |
158 | c->obstacle_count++; | |
159 | } | |
160 | ||
161 | void | |
162 | config_del_obstacle(struct config *c) | |
31b3e1bb | 163 | { |
50fe90ed MM |
164 | DBG("+++ deleting obstacle %d\n", c->obstacle_count); |
165 | c->obstacle_count--; | |
166 | if (!c->obstacle_count) | |
167 | { | |
168 | ASSERT(config_event); | |
169 | ev_schedule(config_event); | |
170 | } | |
171 | } | |
172 | ||
173 | static int | |
bf8558bc | 174 | global_commit(struct config *new, struct config *old) |
50fe90ed MM |
175 | { |
176 | if (!old) | |
177 | return 0; | |
bf8558bc MM |
178 | if (!new->router_id) |
179 | new->router_id = old->router_id; | |
180 | if (new->router_id != old->router_id) | |
50fe90ed MM |
181 | return 1; |
182 | return 0; | |
183 | } | |
184 | ||
185 | static int | |
186 | config_do_commit(struct config *c) | |
187 | { | |
188 | int force_restart, nobs; | |
189 | ||
190 | DBG("do_commit\n"); | |
191 | old_config = config; | |
bf8558bc | 192 | config = new_config = c; |
50fe90ed MM |
193 | if (old_config) |
194 | old_config->obstacle_count++; | |
195 | DBG("sysdep_commit\n"); | |
196 | force_restart = sysdep_commit(c, old_config); | |
197 | DBG("global_commit\n"); | |
198 | force_restart |= global_commit(c, old_config); | |
199 | DBG("rt_commit\n"); | |
200 | rt_commit(c, old_config); | |
201 | DBG("protos_commit\n"); | |
202 | protos_commit(c, old_config, force_restart); | |
203 | new_config = NULL; /* Just to be sure nobody uses that now */ | |
204 | if (old_config) | |
205 | nobs = --old_config->obstacle_count; | |
206 | else | |
207 | nobs = 0; | |
208 | DBG("do_commit finished with %d obstacles remaining\n", nobs); | |
209 | return !nobs; | |
210 | } | |
211 | ||
8f6accb5 | 212 | static void |
7c103b1e | 213 | config_done(void *unused UNUSED) |
50fe90ed MM |
214 | { |
215 | struct config *c; | |
216 | ||
217 | DBG("config_done\n"); | |
218 | for(;;) | |
219 | { | |
bf8558bc MM |
220 | if (config->shutdown) |
221 | sysdep_shutdown_done(); | |
50fe90ed MM |
222 | log(L_INFO "Reconfigured"); |
223 | if (old_config) | |
224 | { | |
225 | config_free(old_config); | |
226 | old_config = NULL; | |
227 | } | |
228 | if (!future_config) | |
229 | break; | |
230 | c = future_config; | |
231 | future_config = NULL; | |
232 | log(L_INFO "Switching to queued configuration..."); | |
233 | if (!config_do_commit(c)) | |
234 | break; | |
235 | } | |
50fe90ed MM |
236 | } |
237 | ||
06607335 MM |
238 | /** |
239 | * config_commit - commit a configuration | |
240 | * @c: new configuration | |
241 | * | |
242 | * When a configuration is parsed and prepared for use, the | |
243 | * config_commit() function starts the process of reconfiguration. | |
244 | * It checks whether there is already a reconfiguration in progress | |
245 | * in which case it just queues the new config for later processing. | |
246 | * Else it notifies all modules about the new configuration by calling | |
247 | * their commit() functions which can either accept it immediately | |
248 | * or call config_add_obstacle() to report that they need some time | |
249 | * to complete the reconfiguration. After all such obstacles are removed | |
250 | * using config_del_obstacle(), the old configuration is freed and | |
251 | * everything runs according to the new one. | |
252 | * | |
253 | * Result: %CONF_DONE if the configuration has been accepted immediately, | |
254 | * %CONF_PROGRESS if it will take some time to switch to it, %CONF_QUEUED | |
255 | * if it's been queued due to another reconfiguration being in progress now | |
256 | * or %CONF_SHUTDOWN if BIRD is in shutdown mode and no new configurations | |
257 | * are accepted. | |
258 | */ | |
50fe90ed MM |
259 | int |
260 | config_commit(struct config *c) | |
261 | { | |
262 | if (!config) /* First-time configuration */ | |
263 | { | |
264 | config_do_commit(c); | |
265 | return CONF_DONE; | |
266 | } | |
267 | if (old_config) /* Reconfiguration already in progress */ | |
268 | { | |
bf8558bc MM |
269 | if (shutting_down) |
270 | { | |
271 | log(L_INFO "New configuration discarded due to shutdown"); | |
272 | config_free(c); | |
273 | return CONF_SHUTDOWN; | |
274 | } | |
50fe90ed MM |
275 | if (future_config) |
276 | { | |
277 | log(L_INFO "Queueing new configuration, ignoring the one already queued"); | |
278 | config_free(future_config); | |
279 | } | |
280 | else | |
281 | log(L_INFO "Queued new configuration"); | |
282 | future_config = c; | |
283 | return CONF_QUEUED; | |
284 | } | |
285 | if (config_do_commit(c)) | |
286 | { | |
287 | config_done(NULL); | |
288 | return CONF_DONE; | |
289 | } | |
290 | if (!config_event) | |
291 | { | |
292 | config_event = ev_new(&root_pool); | |
293 | config_event->hook = config_done; | |
294 | } | |
295 | return CONF_PROGRESS; | |
31b3e1bb MM |
296 | } |
297 | ||
06607335 MM |
298 | /** |
299 | * order_shutdown - order BIRD shutdown | |
300 | * | |
301 | * This function initiates shutdown of BIRD. It's accomplished by asking | |
302 | * for switching to an empty configuration. | |
303 | */ | |
bf8558bc MM |
304 | void |
305 | order_shutdown(void) | |
306 | { | |
307 | struct config *c; | |
308 | ||
309 | if (shutting_down) | |
310 | return; | |
311 | log(L_INFO "Shutting down"); | |
312 | c = lp_alloc(config->mem, sizeof(struct config)); | |
313 | memcpy(c, config, sizeof(struct config)); | |
314 | init_list(&c->protos); | |
315 | init_list(&c->tables); | |
316 | c->shutdown = 1; | |
317 | config_commit(c); | |
318 | shutting_down = 1; | |
319 | } | |
320 | ||
06607335 MM |
321 | /** |
322 | * cf_error - report a configuration error | |
323 | * @msg: printf-like format string | |
324 | * | |
325 | * cf_error() can be called during execution of config_parse(), that is | |
326 | * from the parser, a preconfig hook or a postconfig hook, to report an | |
327 | * error in the configuration. | |
328 | */ | |
31b3e1bb MM |
329 | void |
330 | cf_error(char *msg, ...) | |
331 | { | |
332 | char buf[1024]; | |
333 | va_list args; | |
334 | ||
335 | va_start(args, msg); | |
336 | if (bvsnprintf(buf, sizeof(buf), msg, args) < 0) | |
337 | strcpy(buf, "<bug: error message too long>"); | |
338 | new_config->err_msg = cfg_strdup(buf); | |
339 | new_config->err_lino = conf_lino; | |
340 | longjmp(conf_jmpbuf, 1); | |
341 | } | |
342 | ||
06607335 MM |
343 | /** |
344 | * cfg_strdup - copy a string to config memory | |
345 | * @c: string to copy | |
346 | * | |
347 | * cfg_strdup() creates a new copy of the string in the memory | |
348 | * pool associated with the configuration being currently parsed. | |
349 | * It's often used when a string literal occurs in the configuration | |
350 | * and we want to preserve it for further use. | |
351 | */ | |
31b3e1bb MM |
352 | char * |
353 | cfg_strdup(char *c) | |
354 | { | |
355 | int l = strlen(c) + 1; | |
356 | char *z = cfg_allocu(l); | |
357 | memcpy(z, c, l); | |
358 | return z; | |
359 | } |