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git.ipfire.org Git - thirdparty/bird.git/blob - conf/conf.c
2 * BIRD Internet Routing Daemon -- Configuration File Handling
4 * (c) 1998--2000 Martin Mares <mj@ucw.cz>
6 * Can be freely distributed and used under the terms of the GNU GPL.
10 * DOC: Configuration manager
12 * Configuration of BIRD is complex, yet straightforward. There are three
13 * modules taking care of the configuration: config manager (which takes care
14 * of storage of the config information and controls switching between configs),
15 * lexical analyzer and parser.
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.
21 * There can exist up to four different configurations at one time: an active
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 there is one 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). The stored @old_config
27 * is also used for undo reconfiguration, which works in a similar way.
28 * Reconfiguration could also have timeout (using @config_timer) and undo
29 * is automatically called if the new configuration is not confirmed later.
31 * Loading of new configuration is very simple: just call config_alloc()
32 * to get a new &config structure, then use config_parse() to parse a
33 * configuration file and fill all fields of the structure
34 * and finally ask the config manager to switch to the new
35 * config by calling config_commit().
37 * CLI commands are parsed in a very similar way -- there is also a stripped-down
38 * &config structure associated with them and they are lex-ed and parsed by the
39 * same functions, only a special fake token is prepended before the command
40 * text to make the parser recognize only the rules corresponding to CLI commands.
48 #include "nest/bird.h"
49 #include "nest/route.h"
50 #include "nest/protocol.h"
51 #include "nest/iface.h"
52 #include "lib/resource.h"
53 #include "lib/string.h"
54 #include "lib/event.h"
55 #include "lib/timer.h"
56 #include "conf/conf.h"
57 #include "filter/filter.h"
59 static jmp_buf conf_jmpbuf
;
61 struct config
*config
, *new_config
;
63 static struct config
*old_config
; /* Old configuration */
64 static struct config
*future_config
; /* New config held here if recon requested during recon */
65 static int old_cftype
; /* Type of transition old_config -> config (RECONFIG_SOFT/HARD) */
66 static int future_cftype
; /* Type of scheduled transition, may also be RECONFIG_UNDO */
67 /* Note that when future_cftype is RECONFIG_UNDO, then future_config is NULL,
68 therefore proper check for future scheduled config checks future_cftype */
70 static event
*config_event
; /* Event for finalizing reconfiguration */
71 static timer
*config_timer
; /* Timer for scheduled configuration rollback */
73 /* These are public just for cmd_show_status(), should not be accessed elsewhere */
74 int shutting_down
; /* Shutdown requested, do not accept new config changes */
75 int configuring
; /* Reconfiguration is running */
76 int undo_available
; /* Undo was not requested from last reconfiguration */
77 /* Note that both shutting_down and undo_available are related to requests, not processing */
80 * config_alloc - allocate a new configuration
81 * @name: name of the config
83 * This function creates new &config structure, attaches a resource
84 * pool and a linear memory pool to it and makes it available for
85 * further use. Returns a pointer to the structure.
88 config_alloc(byte
*name
)
90 pool
*p
= rp_new(&root_pool
, "Config");
91 linpool
*l
= lp_new(p
, 4080);
92 struct config
*c
= lp_allocz(l
, sizeof(struct config
));
94 c
->mrtdump_file
= -1; /* Hack, this should be sysdep-specific */
97 c
->file_name
= cfg_strdup(name
);
99 c
->tf_route
= c
->tf_proto
= (struct timeformat
){"%T", "%F", 20*3600};
100 c
->tf_base
= c
->tf_log
= (struct timeformat
){"%F %T", NULL
, 0};
106 * config_parse - parse a configuration
109 * config_parse() reads input by calling a hook function pointed to
110 * by @cf_read_hook and parses it according to the configuration
111 * grammar. It also calls all the preconfig and postconfig hooks
112 * before, resp. after parsing.
114 * Result: 1 if the config has been parsed successfully, 0 if any
115 * error has occurred (such as anybody calling cf_error()) and
116 * the @err_msg field has been set to the error message.
119 config_parse(struct config
*c
)
121 DBG("Parsing configuration file `%s'\n", c
->file_name
);
124 if (setjmp(conf_jmpbuf
))
132 protos_postconfig(c
);
133 if (EMPTY_LIST(c
->protos
))
134 cf_error("No protocol is specified in the config file");
137 cf_error("Router ID must be configured manually on IPv6 routers");
143 * cli_parse - parse a CLI command
144 * @c: temporary config structure
146 * cli_parse() is similar to config_parse(), but instead of a configuration,
147 * it parses a CLI command. See the CLI module for more information.
150 cli_parse(struct config
*c
)
153 c
->sym_fallback
= config
->sym_hash
;
155 if (setjmp(conf_jmpbuf
))
163 * config_free - free a configuration
164 * @c: configuration to be freed
166 * This function takes a &config structure and frees all resources
167 * associated with it.
170 config_free(struct config
*c
)
177 config_add_obstacle(struct config
*c
)
179 DBG("+++ adding obstacle %d\n", c
->obstacle_count
);
184 config_del_obstacle(struct config
*c
)
186 DBG("+++ deleting obstacle %d\n", c
->obstacle_count
);
188 if (!c
->obstacle_count
)
189 ev_schedule(config_event
);
193 global_commit(struct config
*new, struct config
*old
)
198 if (!ipa_equal(old
->listen_bgp_addr
, new->listen_bgp_addr
) ||
199 (old
->listen_bgp_port
!= new->listen_bgp_port
) ||
200 (old
->listen_bgp_flags
!= new->listen_bgp_flags
))
201 log(L_WARN
"Reconfiguration of BGP listening socket not implemented, please restart BIRD.");
205 new->router_id
= old
->router_id
;
207 if (new->router_id_from
)
209 u32 id
= if_choose_router_id(new->router_id_from
, old
->router_id
);
211 log(L_WARN
"Cannot determine router ID, using old one");
221 config_do_commit(struct config
*c
, int type
)
223 if (type
== RECONFIG_UNDO
)
229 config_free(old_config
);
236 if (old_config
&& !config
->shutdown
)
237 log(L_INFO
"Reconfiguring");
239 /* This should not be necessary, but it seems there are some
240 functions that access new_config instead of config */
244 old_config
->obstacle_count
++;
246 DBG("sysdep_commit\n");
247 int force_restart
= sysdep_commit(c
, old_config
);
248 DBG("global_commit\n");
249 force_restart
|= global_commit(c
, old_config
);
251 rt_commit(c
, old_config
);
252 roa_commit(c
, old_config
);
253 DBG("protos_commit\n");
254 protos_commit(c
, old_config
, force_restart
, type
);
256 /* Just to be sure nobody uses that now */
261 obs
= --old_config
->obstacle_count
;
263 DBG("do_commit finished with %d obstacles remaining\n", obs
);
268 config_done(void *unused UNUSED
)
270 if (config
->shutdown
)
271 sysdep_shutdown_done();
275 log(L_INFO
"Reconfigured");
279 int type
= future_cftype
;
280 struct config
*conf
= future_config
;
281 future_cftype
= RECONFIG_NONE
;
282 future_config
= NULL
;
284 log(L_INFO
"Reconfiguring to queued configuration");
285 if (config_do_commit(conf
, type
))
291 * config_commit - commit a configuration
292 * @c: new configuration
293 * @type: type of reconfiguration (RECONFIG_SOFT or RECONFIG_HARD)
294 * @timeout: timeout for undo (or 0 for no timeout)
296 * When a configuration is parsed and prepared for use, the
297 * config_commit() function starts the process of reconfiguration.
298 * It checks whether there is already a reconfiguration in progress
299 * in which case it just queues the new config for later processing.
300 * Else it notifies all modules about the new configuration by calling
301 * their commit() functions which can either accept it immediately
302 * or call config_add_obstacle() to report that they need some time
303 * to complete the reconfiguration. After all such obstacles are removed
304 * using config_del_obstacle(), the old configuration is freed and
305 * everything runs according to the new one.
307 * When @timeout is nonzero, the undo timer is activated with given
308 * timeout. The timer is deactivated when config_commit(),
309 * config_confirm() or config_undo() is called.
311 * Result: %CONF_DONE if the configuration has been accepted immediately,
312 * %CONF_PROGRESS if it will take some time to switch to it, %CONF_QUEUED
313 * if it's been queued due to another reconfiguration being in progress now
314 * or %CONF_SHUTDOWN if BIRD is in shutdown mode and no new configurations
318 config_commit(struct config
*c
, int type
, int timeout
)
323 return CONF_SHUTDOWN
;
328 tm_start(config_timer
, timeout
);
330 tm_stop(config_timer
);
336 log(L_INFO
"Queueing new configuration, ignoring the one already queued");
337 config_free(future_config
);
340 log(L_INFO
"Queueing new configuration");
342 future_cftype
= type
;
347 if (config_do_commit(c
, type
))
352 return CONF_PROGRESS
;
356 * config_confirm - confirm a commited configuration
358 * When the undo timer is activated by config_commit() with nonzero timeout,
359 * this function can be used to deactivate it and therefore confirm
360 * the current configuration.
362 * Result: %CONF_CONFIRM when the current configuration is confirmed,
363 * %CONF_NONE when there is nothing to confirm (i.e. undo timer is not active).
368 if (config_timer
->expires
== 0)
371 tm_stop(config_timer
);
377 * config_undo - undo a configuration
379 * Function config_undo() can be used to change the current
380 * configuration back to stored %old_config. If no reconfiguration is
381 * running, this stored configuration is commited in the same way as a
382 * new configuration in config_commit(). If there is already a
383 * reconfiguration in progress and no next reconfiguration is
384 * scheduled, then the undo is scheduled for later processing as
385 * usual, but if another reconfiguration is already scheduled, then
386 * such reconfiguration is removed instead (i.e. undo is applied on
387 * the last commit that scheduled it).
389 * Result: %CONF_DONE if the configuration has been accepted immediately,
390 * %CONF_PROGRESS if it will take some time to switch to it, %CONF_QUEUED
391 * if it's been queued due to another reconfiguration being in progress now,
392 * %CONF_UNQUEUED if a scheduled reconfiguration is removed, %CONF_NOTHING
393 * if there is no relevant configuration to undo (the previous config request
394 * was config_undo() too) or %CONF_SHUTDOWN if BIRD is in shutdown mode and
395 * no new configuration changes are accepted.
401 return CONF_SHUTDOWN
;
403 if (!undo_available
|| !old_config
)
407 tm_stop(config_timer
);
413 config_free(future_config
);
414 future_config
= NULL
;
416 log(L_INFO
"Removing queued configuration");
417 future_cftype
= RECONFIG_NONE
;
418 return CONF_UNQUEUED
;
422 log(L_INFO
"Queueing undo configuration");
423 future_cftype
= RECONFIG_UNDO
;
428 if (config_do_commit(NULL
, RECONFIG_UNDO
))
433 return CONF_PROGRESS
;
436 extern void cmd_reconfig_undo_notify(void);
439 config_timeout(struct timer
*t
)
441 log(L_INFO
"Config timeout expired, starting undo");
442 cmd_reconfig_undo_notify();
444 int r
= config_undo();
446 log(L_ERR
"Undo request failed");
452 config_event
= ev_new(&root_pool
);
453 config_event
->hook
= config_done
;
455 config_timer
= tm_new(&root_pool
);
456 config_timer
->hook
= config_timeout
;
460 * order_shutdown - order BIRD shutdown
462 * This function initiates shutdown of BIRD. It's accomplished by asking
463 * for switching to an empty configuration.
473 log(L_INFO
"Shutting down");
474 c
= lp_alloc(config
->mem
, sizeof(struct config
));
475 memcpy(c
, config
, sizeof(struct config
));
476 init_list(&c
->protos
);
477 init_list(&c
->tables
);
480 config_commit(c
, RECONFIG_HARD
, 0);
485 * cf_error - report a configuration error
486 * @msg: printf-like format string
488 * cf_error() can be called during execution of config_parse(), that is
489 * from the parser, a preconfig hook or a postconfig hook, to report an
490 * error in the configuration.
493 cf_error(char *msg
, ...)
499 if (bvsnprintf(buf
, sizeof(buf
), msg
, args
) < 0)
500 strcpy(buf
, "<bug: error message too long>");
501 new_config
->err_msg
= cfg_strdup(buf
);
502 new_config
->err_lino
= ifs
->lino
;
503 new_config
->err_file_name
= ifs
->file_name
;
504 longjmp(conf_jmpbuf
, 1);
508 * cfg_strdup - copy a string to config memory
511 * cfg_strdup() creates a new copy of the string in the memory
512 * pool associated with the configuration being currently parsed.
513 * It's often used when a string literal occurs in the configuration
514 * and we want to preserve it for further use.
519 int l
= strlen(c
) + 1;
520 char *z
= cfg_allocu(l
);
527 cfg_copy_list(list
*dest
, list
*src
, unsigned node_size
)
534 dn
= cfg_alloc(node_size
);
535 memcpy(dn
, sn
, node_size
);