1 /*
2  *	BIRD Internet Routing Daemon -- Protocols
3  *
4  *	(c) 1998--2000 Martin Mares <mj@ucw.cz>
5  *
6  *	Can be freely distributed and used under the terms of the GNU GPL.
7  */
8 
9 #ifndef _BIRD_PROTOCOL_H_
10 #define _BIRD_PROTOCOL_H_
11 
12 #include "lib/lists.h"
13 #include "lib/resource.h"
14 #include "lib/timer.h"
15 #include "nest/route.h"
16 #include "conf/conf.h"
17 
18 struct iface;
19 struct ifa;
20 struct rtable;
21 struct rte;
22 struct neighbor;
23 struct rta;
24 struct network;
25 struct proto_config;
26 struct config;
27 struct proto;
28 struct event;
29 struct ea_list;
30 struct eattr;
31 struct symbol;
32 
33 /*
34  *	Routing Protocol
35  */
36 
37 struct protocol {
38   node n;
39   char *name;
40   char *template;			/* Template for automatic generation of names */
41   int name_counter;			/* Counter for automatic name generation */
42   int attr_class;			/* Attribute class known to this protocol */
43   int multitable;			/* Protocol handles all announce hooks itself */
44   uint preference;			/* Default protocol preference */
45   uint config_size;			/* Size of protocol config */
46 
47   void (*preconfig)(struct protocol *, struct config *);	/* Just before configuring */
48   void (*postconfig)(struct proto_config *);			/* After configuring each instance */
49   struct proto * (*init)(struct proto_config *);		/* Create new instance */
50   int (*reconfigure)(struct proto *, struct proto_config *);	/* Try to reconfigure instance, returns success */
51   void (*dump)(struct proto *);			/* Debugging dump */
52   void (*dump_attrs)(struct rte *);		/* Dump protocol-dependent attributes */
53   int (*start)(struct proto *);			/* Start the instance */
54   int (*shutdown)(struct proto *);		/* Stop the instance */
55   void (*cleanup)(struct proto *);		/* Called after shutdown when protocol became hungry/down */
56   void (*get_status)(struct proto *, byte *buf); /* Get instance status (for `show protocols' command) */
57   void (*get_route_info)(struct rte *, byte *buf, struct ea_list *attrs); /* Get route information (for `show route' command) */
58   int (*get_attr)(struct eattr *, byte *buf, int buflen);	/* ASCIIfy dynamic attribute (returns GA_*) */
59   void (*show_proto_info)(struct proto *);	/* Show protocol info (for `show protocols all' command) */
60   void (*copy_config)(struct proto_config *, struct proto_config *);	/* Copy config from given protocol instance */
61 };
62 
63 void protos_build(void);
64 void proto_build(struct protocol *);
65 void protos_preconfig(struct config *);
66 void protos_postconfig(struct config *);
67 void protos_commit(struct config *new, struct config *old, int force_restart, int type);
68 void protos_dump_all(void);
69 
70 #define GA_UNKNOWN	0		/* Attribute not recognized */
71 #define GA_NAME		1		/* Result = name */
72 #define GA_FULL		2		/* Result = both name and value */
73 
74 /*
75  *	Known protocols
76  */
77 
78 extern struct protocol
79   proto_device, proto_radv, proto_rip, proto_static, proto_mrt,
80   proto_ospf, proto_pipe, proto_bgp, proto_bfd, proto_babel;
81 
82 /*
83  *	Routing Protocol Instance
84  */
85 
86 struct proto_config {
87   node n;
88   struct config *global;		/* Global configuration data */
89   struct protocol *protocol;		/* Protocol */
90   struct proto *proto;			/* Instance we've created */
91   char *name;
92   char *dsc;
93   int class;				/* SYM_PROTO or SYM_TEMPLATE */
94   u32 debug, mrtdump;			/* Debugging bitfields, both use D_* constants */
95   unsigned preference, disabled;	/* Generic parameters */
96   int vrf_set;				/* Related VRF instance (below) is defined */
97   int in_keep_filtered;			/* Routes rejected in import filter are kept */
98   u32 router_id;			/* Protocol specific router ID */
99   struct iface *vrf;			/* Related VRF instance, NULL if global */
100   struct rtable_config *table;		/* Table we're attached to */
101   struct filter *in_filter, *out_filter; /* Attached filters */
102   struct proto_limit *rx_limit;		/* Limit for receiving routes from protocol
103 					   (relevant when in_keep_filtered is active) */
104   struct proto_limit *in_limit;		/* Limit for importing routes from protocol */
105   struct proto_limit *out_limit;	/* Limit for exporting routes to protocol */
106 
107   /* Check proto_reconfigure() and proto_copy_config() after changing struct proto_config */
108 
109   /* Protocol-specific data follow... */
110 };
111 
112 /* Protocol statistics */
113 struct proto_stats {
114   /* Import - from protocol to core */
115   u32 imp_routes;		/* Number of routes successfully imported to the (adjacent) routing table */
116   u32 filt_routes;		/* Number of routes rejected in import filter but kept in the routing table */
117   u32 pref_routes;		/* Number of routes that are preferred, sum over all routing tables */
118   u32 imp_updates_received;	/* Number of route updates received */
119   u32 imp_updates_invalid;	/* Number of route updates rejected as invalid */
120   u32 imp_updates_filtered;	/* Number of route updates rejected by filters */
121   u32 imp_updates_ignored;	/* Number of route updates rejected as already in route table */
122   u32 imp_updates_accepted;	/* Number of route updates accepted and imported */
123   u32 imp_withdraws_received;	/* Number of route withdraws received */
124   u32 imp_withdraws_invalid;	/* Number of route withdraws rejected as invalid */
125   u32 imp_withdraws_ignored;	/* Number of route withdraws rejected as already not in route table */
126   u32 imp_withdraws_accepted;	/* Number of route withdraws accepted and processed */
127 
128   /* Export - from core to protocol */
129   u32 exp_routes;		/* Number of routes successfully exported to the protocol */
130   u32 exp_updates_received;	/* Number of route updates received */
131   u32 exp_updates_rejected;	/* Number of route updates rejected by protocol */
132   u32 exp_updates_filtered;	/* Number of route updates rejected by filters */
133   u32 exp_updates_accepted;	/* Number of route updates accepted and exported */
134   u32 exp_withdraws_received;	/* Number of route withdraws received */
135   u32 exp_withdraws_accepted;	/* Number of route withdraws accepted and processed */
136 };
137 
138 struct proto {
139   node n;				/* Node in *_proto_list */
140   node glob_node;			/* Node in global proto_list */
141   struct protocol *proto;		/* Protocol */
142   struct proto_config *cf;		/* Configuration data */
143   struct proto_config *cf_new;		/* Configuration we want to switch to after shutdown (NULL=delete) */
144   pool *pool;				/* Pool containing local objects */
145   struct event *attn;			/* "Pay attention" event */
146 
147   char *name;				/* Name of this instance (== cf->name) */
148   u32 debug;				/* Debugging flags */
149   u32 mrtdump;				/* MRTDump flags */
150   unsigned preference;			/* Default route preference */
151   byte accept_ra_types;			/* Which types of route announcements are accepted (RA_OPTIMAL or RA_ANY) */
152   byte disabled;			/* Manually disabled */
153   byte vrf_set;				/* Related VRF instance (above) is defined */
154   byte proto_state;			/* Protocol state machine (PS_*, see below) */
155   byte core_state;			/* Core state machine (FS_*, see below) */
156   byte export_state;			/* Route export state (ES_*, see below) */
157   byte reconfiguring;			/* We're shutting down due to reconfiguration */
158   byte refeeding;			/* We are refeeding (valid only if export_state == ES_FEEDING) */
159   byte flushing;			/* Protocol is flushed in current flush loop round */
160   byte gr_recovery;			/* Protocol should participate in graceful restart recovery */
161   byte gr_lock;				/* Graceful restart mechanism should wait for this proto */
162   byte gr_wait;				/* Route export to protocol is postponed until graceful restart */
163   byte down_sched;			/* Shutdown is scheduled for later (PDS_*) */
164   byte down_code;			/* Reason for shutdown (PDC_* codes) */
165   byte merge_limit;			/* Maximal number of nexthops for RA_MERGED */
166   u32 hash_key;				/* Random key used for hashing of neighbors */
167   bird_clock_t last_state_change;	/* Time of last state transition */
168   char *last_state_name_announced;	/* Last state name we've announced to the user */
169   char *message;			/* State-change message, allocated from proto_pool */
170   struct proto_stats stats;		/* Current protocol statistics */
171 
172   /*
173    *	General protocol hooks:
174    *
175    *	   if_notify	Notify protocol about interface state changes.
176    *	   ifa_notify	Notify protocol about interface address changes.
177    *	   rt_notify	Notify protocol about routing table updates.
178    *	   neigh_notify	Notify protocol about neighbor cache events.
179    *	   make_tmp_attrs  Construct ea_list from private attrs stored in rte.
180    *	   store_tmp_attrs Store private attrs back to the rte.
181    *	   import_control  Called as the first step of the route importing process.
182    *			It can construct a new rte, add private attributes and
183    *			decide whether the route shall be imported: 1=yes, -1=no,
184    *			0=process it through the import filter set by the user.
185    *	   reload_routes   Request protocol to reload all its routes to the core
186    *			(using rte_update()). Returns: 0=reload cannot be done,
187    *			1= reload is scheduled and will happen (asynchronously).
188    *	   feed_begin	Notify protocol about beginning of route feeding.
189    *	   feed_end	Notify protocol about finish of route feeding.
190    */
191 
192   void (*if_notify)(struct proto *, unsigned flags, struct iface *i);
193   void (*ifa_notify)(struct proto *, unsigned flags, struct ifa *a);
194   void (*rt_notify)(struct proto *, struct rtable *table, struct network *net, struct rte *new, struct rte *old, struct ea_list *attrs);
195   void (*neigh_notify)(struct neighbor *neigh);
196   struct ea_list *(*make_tmp_attrs)(struct rte *rt, struct linpool *pool);
197   void (*store_tmp_attrs)(struct rte *rt, struct ea_list *attrs);
198   int (*import_control)(struct proto *, struct rte **rt, struct ea_list **attrs, struct linpool *pool);
199   int (*reload_routes)(struct proto *);
200   void (*feed_begin)(struct proto *, int initial);
201   void (*feed_end)(struct proto *);
202 
203   /*
204    *	Routing entry hooks (called only for routes belonging to this protocol):
205    *
206    *	   rte_recalculate Called at the beginning of the best route selection
207    *	   rte_better	Compare two rte's and decide which one is better (1=first, 0=second).
208    *       rte_same	Compare two rte's and decide whether they are identical (1=yes, 0=no).
209    *       rte_mergable	Compare two rte's and decide whether they could be merged (1=yes, 0=no).
210    *	   rte_insert	Called whenever a rte is inserted to a routing table.
211    *	   rte_remove	Called whenever a rte is removed from the routing table.
212    */
213 
214   int (*rte_recalculate)(struct rtable *, struct network *, struct rte *, struct rte *, struct rte *);
215   int (*rte_better)(struct rte *, struct rte *);
216   int (*rte_same)(struct rte *, struct rte *);
217   int (*rte_mergable)(struct rte *, struct rte *);
218   struct rte * (*rte_modify)(struct rte *, struct linpool *);
219   void (*rte_insert)(struct network *, struct rte *);
220   void (*rte_remove)(struct network *, struct rte *);
221 
222   struct iface *vrf;			/* Related VRF instance, NULL if global */
223   struct rtable *table;			/* Our primary routing table */
224   struct rte_src *main_source;		/* Primary route source */
225   struct announce_hook *main_ahook;	/* Primary announcement hook */
226   struct announce_hook *ahooks;		/* Announcement hooks for this protocol */
227 
228   struct fib_iterator *feed_iterator;	/* Routing table iterator used during protocol feeding */
229   struct announce_hook *feed_ahook;	/* Announce hook we currently feed */
230 
231   /* Hic sunt protocol-specific data */
232 };
233 
234 struct proto_spec {
235   void *ptr;
236   int patt;
237 };
238 
239 
240 #define PDS_DISABLE		1	/* Proto disable scheduled */
241 #define PDS_RESTART		2	/* Proto restart scheduled */
242 
243 #define PDC_CF_REMOVE		0x01	/* Removed in new config */
244 #define PDC_CF_DISABLE		0x02	/* Disabled in new config */
245 #define PDC_CF_RESTART		0x03	/* Restart due to reconfiguration */
246 #define PDC_CMD_DISABLE		0x11	/* Result of disable command */
247 #define PDC_CMD_RESTART		0x12	/* Result of restart command */
248 #define PDC_CMD_SHUTDOWN	0x13	/* Result of global shutdown */
249 #define PDC_RX_LIMIT_HIT	0x21	/* Route receive limit reached */
250 #define PDC_IN_LIMIT_HIT	0x22	/* Route import limit reached */
251 #define PDC_OUT_LIMIT_HIT	0x23	/* Route export limit reached */
252 
253 
254 void *proto_new(struct proto_config *, unsigned size);
255 void *proto_config_new(struct protocol *, int class);
256 void proto_copy_config(struct proto_config *dest, struct proto_config *src);
257 void proto_set_message(struct proto *p, char *msg, int len);
258 void proto_request_feeding(struct proto *p);
259 
260 static inline void
proto_copy_rest(struct proto_config * dest,struct proto_config * src,unsigned size)261 proto_copy_rest(struct proto_config *dest, struct proto_config *src, unsigned size)
262 { memcpy(dest + 1, src + 1, size - sizeof(struct proto_config)); }
263 
264 void graceful_restart_recovery(void);
265 void graceful_restart_init(void);
266 void graceful_restart_show_status(void);
267 void proto_graceful_restart_lock(struct proto *p);
268 void proto_graceful_restart_unlock(struct proto *p);
269 
270 #define DEFAULT_GR_WAIT	240
271 
272 void proto_show_limit(struct proto_limit *l, const char *dsc);
273 void proto_show_basic_info(struct proto *p);
274 
275 void proto_cmd_show(struct proto *, uintptr_t, int);
276 void proto_cmd_disable(struct proto *, uintptr_t, int);
277 void proto_cmd_enable(struct proto *, uintptr_t, int);
278 void proto_cmd_restart(struct proto *, uintptr_t, int);
279 void proto_cmd_reload(struct proto *, uintptr_t, int);
280 void proto_cmd_debug(struct proto *, uintptr_t, int);
281 void proto_cmd_mrtdump(struct proto *, uintptr_t, int);
282 
283 void proto_apply_cmd(struct proto_spec ps, void (* cmd)(struct proto *, uintptr_t, int), int restricted, uintptr_t arg);
284 struct proto *proto_get_named(struct symbol *, struct protocol *);
285 
286 #define CMD_RELOAD	0
287 #define CMD_RELOAD_IN	1
288 #define CMD_RELOAD_OUT	2
289 
290 static inline u32
proto_get_router_id(struct proto_config * pc)291 proto_get_router_id(struct proto_config *pc)
292 {
293   return pc->router_id ? pc->router_id : pc->global->router_id;
294 }
295 
296 static inline struct ea_list *
rte_make_tmp_attrs(struct rte * rt,struct linpool * pool)297 rte_make_tmp_attrs(struct rte *rt, struct linpool *pool)
298 {
299   struct ea_list *(*mta)(struct rte *rt, struct linpool *pool);
300   mta = rt->attrs->src->proto->make_tmp_attrs;
301   return mta ? mta(rt, pool) : NULL;
302 }
303 
304 /* Moved from route.h to avoid dependency conflicts */
rte_update(struct proto * p,net * net,rte * new)305 static inline void rte_update(struct proto *p, net *net, rte *new) { rte_update2(p->main_ahook, net, new, p->main_source); }
306 
307 extern list active_proto_list;
308 
309 /*
310  *  Each protocol instance runs two different state machines:
311  *
312  *  [P] The protocol machine: (implemented inside protocol)
313  *
314  *		DOWN    ---->    START
315  *		  ^		   |
316  *		  |		   V
317  *		STOP    <----     UP
318  *
319  *	States:	DOWN	Protocol is down and it's waiting for the core
320  *			requesting protocol start.
321  *		START	Protocol is waiting for connection with the rest
322  *			of the network and it's not willing to accept
323  *			packets. When it connects, it goes to UP state.
324  *		UP	Protocol is up and running. When the network
325  *			connection breaks down or the core requests
326  *			protocol to be terminated, it goes to STOP state.
327  *		STOP	Protocol is disconnecting from the network.
328  *			After it disconnects, it returns to DOWN state.
329  *
330  *	In:	start()	Called in DOWN state to request protocol startup.
331  *			Returns new state: either UP or START (in this
332  *			case, the protocol will notify the core when it
333  *			finally comes UP).
334  *		stop()	Called in START, UP or STOP state to request
335  *			protocol shutdown. Returns new state: either
336  *			DOWN or STOP (in this case, the protocol will
337  *			notify the core when it finally comes DOWN).
338  *
339  *	Out:	proto_notify_state() -- called by protocol instance when
340  *			it does any state transition not covered by
341  *			return values of start() and stop(). This includes
342  *			START->UP (delayed protocol startup), UP->STOP
343  *			(spontaneous shutdown) and STOP->DOWN (delayed
344  *			shutdown).
345  */
346 
347 #define PS_DOWN 0
348 #define PS_START 1
349 #define PS_UP 2
350 #define PS_STOP 3
351 
352 void proto_notify_state(struct proto *p, unsigned state);
353 
354 /*
355  *  [F] The feeder machine: (implemented in core routines)
356  *
357  *		HUNGRY    ---->   FEEDING
358  *		 ^		     |
359  *		 | 		     V
360  *		FLUSHING  <----   HAPPY
361  *
362  *	States:	HUNGRY	Protocol either administratively down (i.e.,
363  *			disabled by the user) or temporarily down
364  *			(i.e., [P] is not UP)
365  *		FEEDING	The protocol came up and we're feeding it
366  *			initial routes. [P] is UP.
367  *		HAPPY	The protocol is up and it's receiving normal
368  *			routing updates. [P] is UP.
369  *		FLUSHING The protocol is down and we're removing its
370  *			routes from the table. [P] is STOP or DOWN.
371  *
372  *	Normal lifecycle of a protocol looks like:
373  *
374  *		HUNGRY/DOWN --> HUNGRY/START --> HUNGRY/UP -->
375  *		FEEDING/UP --> HAPPY/UP --> FLUSHING/STOP|DOWN -->
376  *		HUNGRY/STOP|DOWN --> HUNGRY/DOWN
377  *
378  *	Sometimes, protocol might switch from HAPPY/UP to FEEDING/UP
379  *	if it wants to refeed the routes (for example BGP does so
380  *	as a result of received ROUTE-REFRESH request).
381  */
382 
383 #define FS_HUNGRY	0
384 #define FS_FEEDING	1	/* obsolete */
385 #define FS_HAPPY	2
386 #define FS_FLUSHING	3
387 
388 
389 #define ES_DOWN		0
390 #define ES_FEEDING	1
391 #define ES_READY	2
392 
393 
394 
395 /*
396  *	Debugging flags
397  */
398 
399 #define D_STATES 1		/* [core] State transitions */
400 #define D_ROUTES 2		/* [core] Routes passed by the filters */
401 #define D_FILTERS 4		/* [core] Routes rejected by the filters */
402 #define D_IFACES 8		/* [core] Interface events */
403 #define D_EVENTS 16		/* Protocol events */
404 #define D_PACKETS 32		/* Packets sent/received */
405 
406 #ifndef PARSER
407 #define TRACE(flags, msg, args...) \
408   do { if (p->p.debug & flags) log(L_TRACE "%s: " msg, p->p.name , ## args ); } while(0)
409 #endif
410 
411 
412 /*
413  *	MRTDump flags
414  */
415 
416 #define MD_STATES	1		/* Protocol state changes (BGP4MP_MESSAGE_AS4) */
417 #define MD_MESSAGES	2		/* Protocol packets (BGP4MP_MESSAGE_AS4) */
418 
419 /*
420  *	Known unique protocol instances as referenced by config routines
421  */
422 
423 extern struct proto_config *cf_dev_proto;
424 
425 
426 /*
427  * Protocol limits
428  */
429 
430 #define PLD_RX		0	/* Receive limit */
431 #define PLD_IN		1	/* Import limit */
432 #define PLD_OUT		2	/* Export limit */
433 #define PLD_MAX		3
434 
435 #define PLA_WARN	1	/* Issue log warning */
436 #define PLA_BLOCK	2	/* Block new routes */
437 #define PLA_RESTART	4	/* Force protocol restart */
438 #define PLA_DISABLE	5	/* Shutdown and disable protocol */
439 
440 #define PLS_INITIAL	0	/* Initial limit state after protocol start */
441 #define PLS_ACTIVE	1	/* Limit was hit */
442 #define PLS_BLOCKED	2	/* Limit is active and blocking new routes */
443 
444 struct proto_limit {
445   u32 limit;			/* Maximum number of prefixes */
446   byte action;			/* Action to take (PLA_*) */
447   byte state;			/* State of limit (PLS_*) */
448 };
449 
450 void proto_notify_limit(struct announce_hook *ah, struct proto_limit *l, int dir, u32 rt_count);
451 void proto_verify_limits(struct announce_hook *ah);
452 
453 static inline void
proto_reset_limit(struct proto_limit * l)454 proto_reset_limit(struct proto_limit *l)
455 {
456   if (l)
457     l->state = PLS_INITIAL;
458 }
459 
460 
461 /*
462  *	Route Announcement Hook
463  */
464 
465 struct announce_hook {
466   node n;
467   struct rtable *table;
468   struct proto *proto;
469   struct filter *in_filter;		/* Input filter */
470   struct filter *out_filter;		/* Output filter */
471   struct proto_limit *rx_limit;		/* Receive limit (for in_keep_filtered) */
472   struct proto_limit *in_limit;		/* Input limit */
473   struct proto_limit *out_limit;	/* Output limit */
474   struct proto_stats *stats;		/* Per-table protocol statistics */
475   struct announce_hook *next;		/* Next hook for the same protocol */
476   int in_keep_filtered;			/* Routes rejected in import filter are kept */
477   bird_clock_t last_out_filter_change;	/* Last time when out_filter _changed_ */
478 };
479 
480 struct announce_hook *proto_add_announce_hook(struct proto *p, struct rtable *t, struct proto_stats *stats);
481 struct announce_hook *proto_find_announce_hook(struct proto *p, struct rtable *t);
482 
483 #endif
484