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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 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).
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
30 * configuration file and fill all fields of the structure
31 * and finally ask the config manager to switch to the new
32 * config by calling config_commit().
34 * CLI commands are parsed in a very similar way -- there is also a stripped-down
35 * &config structure associated with them and they are lex-ed and parsed by the
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.
45 #include "nest/bird.h"
46 #include "nest/route.h"
47 #include "nest/protocol.h"
48 #include "nest/iface.h"
49 #include "lib/resource.h"
50 #include "lib/string.h"
51 #include "lib/event.h"
52 #include "lib/timer.h"
53 #include "conf/conf.h"
54 #include "filter/filter.h"
56 static jmp_buf conf_jmpbuf
;
58 struct config
*config
, *new_config
, *old_config
, *future_config
;
59 static event
*config_event
;
61 bird_clock_t boot_time
;
64 * config_alloc - allocate a new configuration
65 * @name: name of the config
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.
72 config_alloc(byte
*name
)
74 pool
*p
= rp_new(&root_pool
, "Config");
75 linpool
*l
= lp_new(p
, 4080);
76 struct config
*c
= lp_allocz(l
, sizeof(struct config
));
80 c
->file_name
= cfg_strdup(name
);
88 * config_parse - parse a configuration
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
94 * before, resp. after parsing.
96 * Result: 1 if the config has been parsed successfully, 0 if any
97 * error has occurred (such as anybody calling cf_error()) and
98 * the @err_msg field has been set to the error message.
101 config_parse(struct config
*c
)
103 DBG("Parsing configuration file `%s'\n", c
->file_name
);
106 if (setjmp(conf_jmpbuf
))
113 protos_postconfig(c
);
116 cf_error("Router ID must be configured manually on IPv6 routers");
122 * cli_parse - parse a CLI command
123 * @c: temporary config structure
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.
129 cli_parse(struct config
*c
)
132 c
->sym_fallback
= config
->sym_hash
;
134 if (setjmp(conf_jmpbuf
))
142 * config_free - free a configuration
143 * @c: configuration to be freed
145 * This function takes a &config structure and frees all resources
146 * associated with it.
149 config_free(struct config
*c
)
155 config_add_obstacle(struct config
*c
)
157 DBG("+++ adding obstacle %d\n", c
->obstacle_count
);
162 config_del_obstacle(struct config
*c
)
164 DBG("+++ deleting obstacle %d\n", c
->obstacle_count
);
166 if (!c
->obstacle_count
)
168 ASSERT(config_event
);
169 ev_schedule(config_event
);
174 global_commit(struct config
*new, struct config
*old
)
179 if (!ipa_equal(old
->bind_bgp_addr
, new->bind_bgp_addr
) ||
180 (old
->bind_bgp_port
!= new->bind_bgp_port
) ||
181 (old
->bind_bgp_flags
!= new->bind_bgp_flags
))
182 log(L_WARN
"Reconfiguration of BGP listening socket not implemented, please restart BIRD.");
185 new->router_id
= old
->router_id
;
186 if (new->router_id
!= old
->router_id
)
192 config_do_commit(struct config
*c
, int type
)
194 int force_restart
, nobs
;
198 config
= new_config
= c
;
200 old_config
->obstacle_count
++;
201 DBG("sysdep_commit\n");
202 force_restart
= sysdep_commit(c
, old_config
);
203 DBG("global_commit\n");
204 force_restart
|= global_commit(c
, old_config
);
206 rt_commit(c
, old_config
);
207 DBG("protos_commit\n");
208 protos_commit(c
, old_config
, force_restart
, type
);
209 new_config
= NULL
; /* Just to be sure nobody uses that now */
211 nobs
= --old_config
->obstacle_count
;
214 DBG("do_commit finished with %d obstacles remaining\n", nobs
);
219 config_done(void *unused UNUSED
)
223 DBG("config_done\n");
226 if (config
->shutdown
)
227 sysdep_shutdown_done();
228 log(L_INFO
"Reconfigured");
231 config_free(old_config
);
237 future_config
= NULL
;
238 log(L_INFO
"Switching to queued configuration...");
239 if (!config_do_commit(c
, RECONFIG_HARD
))
245 * config_commit - commit a configuration
246 * @c: new configuration
247 * @type: type of reconfiguration (RECONFIG_SOFT or RECONFIG_HARD)
249 * When a configuration is parsed and prepared for use, the
250 * config_commit() function starts the process of reconfiguration.
251 * It checks whether there is already a reconfiguration in progress
252 * in which case it just queues the new config for later processing.
253 * Else it notifies all modules about the new configuration by calling
254 * their commit() functions which can either accept it immediately
255 * or call config_add_obstacle() to report that they need some time
256 * to complete the reconfiguration. After all such obstacles are removed
257 * using config_del_obstacle(), the old configuration is freed and
258 * everything runs according to the new one.
260 * Result: %CONF_DONE if the configuration has been accepted immediately,
261 * %CONF_PROGRESS if it will take some time to switch to it, %CONF_QUEUED
262 * if it's been queued due to another reconfiguration being in progress now
263 * or %CONF_SHUTDOWN if BIRD is in shutdown mode and no new configurations
267 config_commit(struct config
*c
, int type
)
269 if (!config
) /* First-time configuration */
271 config_do_commit(c
, RECONFIG_HARD
);
274 if (old_config
) /* Reconfiguration already in progress */
276 if (shutting_down
== 2)
278 log(L_INFO
"New configuration discarded due to shutdown");
280 return CONF_SHUTDOWN
;
284 log(L_INFO
"Queueing new configuration, ignoring the one already queued");
285 config_free(future_config
);
288 log(L_INFO
"Queued new configuration");
292 if (config_do_commit(c
, type
))
299 config_event
= ev_new(&root_pool
);
300 config_event
->hook
= config_done
;
302 return CONF_PROGRESS
;
306 * order_shutdown - order BIRD shutdown
308 * This function initiates shutdown of BIRD. It's accomplished by asking
309 * for switching to an empty configuration.
318 log(L_INFO
"Shutting down");
319 c
= lp_alloc(config
->mem
, sizeof(struct config
));
320 memcpy(c
, config
, sizeof(struct config
));
321 init_list(&c
->protos
);
322 init_list(&c
->tables
);
325 config_commit(c
, RECONFIG_HARD
);
330 * cf_error - report a configuration error
331 * @msg: printf-like format string
333 * cf_error() can be called during execution of config_parse(), that is
334 * from the parser, a preconfig hook or a postconfig hook, to report an
335 * error in the configuration.
338 cf_error(char *msg
, ...)
344 if (bvsnprintf(buf
, sizeof(buf
), msg
, args
) < 0)
345 strcpy(buf
, "<bug: error message too long>");
346 new_config
->err_msg
= cfg_strdup(buf
);
347 new_config
->err_lino
= conf_lino
;
348 longjmp(conf_jmpbuf
, 1);
352 * cfg_strdup - copy a string to config memory
355 * cfg_strdup() creates a new copy of the string in the memory
356 * pool associated with the configuration being currently parsed.
357 * It's often used when a string literal occurs in the configuration
358 * and we want to preserve it for further use.
363 int l
= strlen(c
) + 1;
364 char *z
= cfg_allocu(l
);