summaryrefslogtreecommitdiffstats
path: root/nest/route.h
blob: cd9e9ff761083ec8734714353e0b3cc6d54d95c1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
/*
 *	BIRD Internet Routing Daemon -- Routing Table
 *
 *	(c) 1998--2000 Martin Mares <mj@ucw.cz>
 *
 *	Can be freely distributed and used under the terms of the GNU GPL.
 */

#ifndef _BIRD_ROUTE_H_
#define _BIRD_ROUTE_H_

#include "lib/lists.h"
#include "lib/resource.h"
#include "lib/timer.h"

struct protocol;
struct proto;
struct symbol;
struct filter;
struct cli;

/*
 *	Generic data structure for storing network prefixes. Also used
 *	for the master routing table. Currently implemented as a hash
 *	table.
 *
 *	Available operations:
 *		- insertion of new entry
 *		- deletion of entry
 *		- searching for entry by network prefix
 *		- asynchronous retrieval of fib contents
 */

struct fib_node {
  struct fib_node *next;		/* Next in hash chain */
  struct fib_iterator *readers;		/* List of readers of this node */
  byte pxlen;
  byte flags;				/* User-defined */
  byte x0, x1;				/* User-defined */
  ip_addr prefix;			/* In host order */
};

struct fib_iterator {			/* See lib/slists.h for an explanation */
  struct fib_iterator *prev, *next;	/* Must be synced with struct fib_node! */
  struct fib_node *node;		/* Or NULL if freshly merged */
  byte efef;				/* 0xff to distinguish between iterator and node */
  byte pad[3];
  unsigned int hash;
};

struct fib {
  pool *fib_pool;			/* Pool holding all our data */
  slab *fib_slab;			/* Slab holding all fib nodes */
  struct fib_node **hash_table;		/* Node hash table */
  unsigned int hash_size;		/* Number of hash table entries (a power of two) */
  unsigned int hash_order;		/* Binary logarithm of hash_size */
  unsigned int hash_shift;		/* 16 - hash_log */
  unsigned int entries;			/* Number of entries */
  unsigned int entries_min, entries_max;/* Entry count limits (else start rehashing) */
  void (*init)(struct fib_node *);	/* Constructor */
};

void fib_init(struct fib *, pool *, unsigned node_size, unsigned hash_order, void (*init)(struct fib_node *));
void *fib_find(struct fib *, ip_addr *, int);	/* Find or return NULL if doesn't exist */
void *fib_get(struct fib *, ip_addr *, int); 	/* Find or create new if nonexistent */
void fib_delete(struct fib *, void *);	/* Remove fib entry */
void fib_free(struct fib *);		/* Destroy the fib */
void fib_check(struct fib *);		/* Consistency check for debugging */

void fit_init(struct fib_iterator *, struct fib *); /* Internal functions, don't call */
struct fib_node *fit_get(struct fib *, struct fib_iterator *);
void fit_put(struct fib_iterator *, struct fib_node *);

#define FIB_WALK(fib, z) do {					\
	struct fib_node *z, **ff = (fib)->hash_table;		\
	unsigned int count = (fib)->hash_size;			\
	while (count--)						\
	  for(z = *ff++; z; z=z->next)

#define FIB_WALK_END } while (0)

#define FIB_ITERATE_INIT(it, fib) fit_init(it, fib)

#define FIB_ITERATE_START(fib, it, z) do {			\
	struct fib_node *z = fit_get(fib, it);			\
	unsigned int count = (fib)->hash_size;			\
	unsigned int hpos = (it)->hash;				\
	for(;;) {						\
	fis_again:	if (!z) {				\
			if (++hpos >= count)			\
				break;				\
			z = (fib)->hash_table[hpos];		\
			goto fis_again;				\
		}

#define FIB_ITERATE_END(z) z = z->next; } } while(0)

#define FIB_ITERATE_PUT(it, z) fit_put(it, z)

/*
 *	Master Routing Tables. Generally speaking, each of them contains a FIB
 *	with each entry pointing to a list of route entries representing routes
 *	to given network (with the selected one at the head).
 *
 *	Each of the RTE's contains variable data (the preference and protocol-dependent
 *	metrics) and a pointer to a route attribute block common for many routes).
 *
 *	It's guaranteed that there is at most one RTE for every (prefix,proto) pair.
 */

struct rtable_config {
  node n;
  char *name;
  struct rtable *table;
  struct proto_config *krt_attached;	/* Kernel syncer attached to this table */
  int gc_max_ops;			/* Maximum number of operations before GC is run */
  int gc_min_time;			/* Minimum time between two consecutive GC runs */
};

typedef struct rtable {
  node n;				/* Node in list of all tables */
  struct fib fib;
  char *name;				/* Name of this table */
  list hooks;				/* List of announcement hooks */
  int pipe_busy;			/* Pipe loop detection */
  int use_count;			/* Number of protocols using this table */
  struct rtable_config *config;		/* Configuration of this table */
  struct config *deleted;		/* Table doesn't exist in current configuration,
					 * delete as soon as use_count becomes 0 and remove
					 * obstacle from this routing table.
					 */
  struct event *gc_event;		/* Garbage collector event */
  int gc_counter;			/* Number of operations since last GC */
  bird_clock_t gc_time;			/* Time of last GC */
} rtable;

typedef struct network {
  struct fib_node n;			/* FIB flags reserved for kernel syncer */
  struct rte *routes;			/* Available routes for this network */
} net;

typedef struct rte {
  struct rte *next;
  net *net;				/* Network this RTE belongs to */
  struct rta *attrs;			/* Attributes of this route */
  byte flags;				/* Flags (REF_...) */
  byte pflags;				/* Protocol-specific flags */
  word pref;				/* Route preference */
  bird_clock_t lastmod;			/* Last modified */
  union {				/* Protocol-dependent data (metrics etc.) */
#ifdef CONFIG_RIP
    struct {
      node garbage;			/* List for garbage collection */
      byte metric;			/* RIP metric */
      u16 tag;				/* External route tag */
      bird_clock_t lastmodX;		/* Strange kind of last modification time */
    } rip;
#endif
#ifdef CONFIG_OSPF
    struct {
      u32 metric1, metric2;		/* OSPF Type 1 and Type 2 metrics */
      u32 tag;				/* External route tag */
    } ospf;
#endif
    struct {				/* Routes generated by krt sync (both temporary and inherited ones) */
      s8 src;				/* Alleged route source (see krt.h) */
      u8 proto;				/* Kernel source protocol ID */
      u8 type;				/* Kernel route type */
      u8 seen;				/* Seen during last scan */
      u32 metric;			/* Kernel metric */
    } krt;
  } u;
} rte;

#define REF_COW 1			/* Copy this rte on write */

struct config;

void rt_init(void);
void rt_preconfig(struct config *);
void rt_commit(struct config *new, struct config *old);
void rt_lock_table(rtable *);
void rt_unlock_table(rtable *);
void rt_setup(pool *, rtable *, char *, struct rtable_config *);
static inline net *net_find(rtable *tab, ip_addr addr, unsigned len) { return (net *) fib_find(&tab->fib, &addr, len); }
static inline net *net_get(rtable *tab, ip_addr addr, unsigned len) { return (net *) fib_get(&tab->fib, &addr, len); }
rte *rte_find(net *net, struct proto *p);
rte *rte_get_temp(struct rta *);
void rte_update(rtable *tab, net *net, struct proto *p, rte *new);
void rte_discard(rtable *tab, rte *old);
void rte_dump(rte *);
void rte_free(rte *);
rte *rte_do_cow(rte *);
static inline rte * rte_cow(rte *r) { return (r->flags & REF_COW) ? rte_do_cow(r) : r; }
void rt_dump(rtable *);
void rt_dump_all(void);
void rt_feed_baby(struct proto *p);
void rt_prune(rtable *tab);
void rt_prune_all(void);
struct rtable_config *rt_new_table(struct symbol *s);

struct rt_show_data {
  ip_addr prefix;
  unsigned pxlen;
  rtable *table;
  struct filter *filter;
  int verbose;
  struct fib_iterator fit;
};
void rt_show(struct rt_show_data *);

/*
 *	Route Attributes
 *
 *	Beware: All standard BGP attributes must be represented here instead
 *	of making them local to the route. This is needed to ensure proper
 *	construction of BGP route attribute lists.
 */

typedef struct rta {
  struct rta *next, **pprev;		/* Hash chain */
  struct proto *proto;			/* Protocol instance */
  unsigned uc;				/* Use count */
  byte source;				/* Route source (RTS_...) */
  byte scope;				/* Route scope (SCOPE_... -- see ip.h) */
  byte cast;				/* Casting type (RTC_...) */
  byte dest;				/* Route destination type (RTD_...) */
  byte flags;				/* Route flags (RTF_...), now unused */
  byte aflags;				/* Attribute cache flags (RTAF_...) */
  u16 hash_key;				/* Hash over important fields */
  ip_addr gw;				/* Next hop */
  ip_addr from;				/* Advertising router */
  struct iface *iface;			/* Outgoing interface */
  struct ea_list *eattrs;		/* Extended Attribute chain */
} rta;

#define RTS_DUMMY 0			/* Dummy route to be removed soon */
#define RTS_STATIC 1			/* Normal static route */
#define RTS_INHERIT 2			/* Route inherited from kernel */
#define RTS_DEVICE 3			/* Device route */
#define RTS_STATIC_DEVICE 4		/* Static device route */
#define RTS_REDIRECT 5			/* Learned via redirect */
#define RTS_RIP 6			/* RIP route */
#define RTS_OSPF 7			/* OSPF route */
#define RTS_OSPF_EXT 8			/* OSPF external route */
#define RTS_OSPF_IA 9			/* OSPF inter-area route */
#define RTS_OSPF_BOUNDARY 10		/* OSPF route to boundary router */
#define RTS_BGP 11			/* BGP route */
#define RTS_PIPE 12			/* Inter-table wormhole */

#define RTC_UNICAST 0
#define RTC_BROADCAST 1
#define RTC_MULTICAST 2
#define RTC_ANYCAST 3			/* IPv6 Anycast */

#define RTD_ROUTER 0			/* Next hop is neighbor router */
#define RTD_DEVICE 1			/* Points to device */
#define RTD_BLACKHOLE 2			/* Silently drop packets */
#define RTD_UNREACHABLE 3		/* Reject as unreachable */
#define RTD_PROHIBIT 4			/* Administratively prohibited */

#define RTAF_CACHED 1			/* This is a cached rta */

/*
 *	Extended Route Attributes
 */

typedef struct eattr {
  word id;				/* EA_CODE(EAP_..., protocol-dependent ID) */
  byte flags;				/* Protocol-dependent flags */
  byte type;				/* Attribute type and several flags (EAF_...) */
  union {
    u32 data;
    struct adata *ptr;			/* Attribute data elsewhere */
  } u;
} eattr;

#define EAP_GENERIC 0			/* Generic attributes */
#define EAP_BGP 1			/* BGP attributes */
#define EAP_RIP 2			/* RIP */
#define EAP_MAX 3

#define EA_CODE(proto,id) (((proto) << 8) | (id))
#define EA_PROTO(ea) ((ea) >> 8)
#define EA_ID(ea) ((ea) & 0xff)

#define EA_CODE_MASK 0xffff
#define EA_ALLOW_UNDEF 0x10000		/* ea_find: allow EAF_TYPE_UNDEF */

#define EAF_TYPE_MASK 0x0f		/* Mask with this to get type */
#define EAF_TYPE_INT 0x01		/* 32-bit signed integer number */
#define EAF_TYPE_OPAQUE 0x02		/* Opaque byte string (not filterable) */
#define EAF_TYPE_IP_ADDRESS 0x04	/* IP address */
#define EAF_TYPE_ROUTER_ID 0x05		/* Router ID (IPv4 address) */
#define EAF_TYPE_AS_PATH 0x06		/* BGP AS path (encoding per RFC 1771:4.3) */
#define EAF_TYPE_INT_SET 0x0a		/* Set of u32's (e.g., a community list) */
#define EAF_TYPE_UNDEF 0x0f		/* `force undefined' entry */
#define EAF_EMBEDDED 0x01		/* Data stored in eattr.u.data (part of type spec) */
#define EAF_VAR_LENGTH 0x02		/* Attribute length is variable (part of type spec) */
#define EAF_ORIGINATED 0x40		/* The attribute has originated locally */
#define EAF_TEMP 0x80			/* A temporary attribute (the one stored in the tmp attr list) */

struct adata {
  unsigned int length;			/* Length of data */
  byte data[0];
};

typedef struct ea_list {
  struct ea_list *next;			/* In case we have an override list */
  byte flags;				/* Flags: EALF_... */
  byte rfu;
  word count;				/* Number of attributes */
  eattr attrs[0];			/* Attribute definitions themselves */
} ea_list;

#define EALF_SORTED 1			/* Attributes are sorted by code */
#define EALF_BISECT 2			/* Use interval bisection for searching */
#define EALF_CACHED 4			/* Attributes belonging to cached rta */

eattr *ea_find(ea_list *, unsigned ea);
void ea_dump(ea_list *);
void ea_sort(ea_list *);		/* Sort entries in all sub-lists */
unsigned ea_scan(ea_list *);		/* How many bytes do we need for merged ea_list */
void ea_merge(ea_list *from, ea_list *to); /* Merge sub-lists to allocated buffer */
int ea_same(ea_list *x, ea_list *y);	/* Test whether two ea_lists are identical */
unsigned int ea_hash(ea_list *e);	/* Calculate 16-bit hash value */
void ea_format(eattr *e, byte *buf);
#define EA_FORMAT_BUF_SIZE 256

void rta_init(void);
rta *rta_lookup(rta *);			/* Get rta equivalent to this one, uc++ */
static inline rta *rta_clone(rta *r) { r->uc++; return r; }
void rta__free(rta *r);
static inline void rta_free(rta *r) { if (r && !--r->uc) rta__free(r); }
void rta_dump(rta *);
void rta_dump_all(void);
static inline eattr * rta_find(rta *a, unsigned ea) { return ea_find(a->eattrs, ea); }
void rta_show(struct cli *, rta *);

extern struct protocol *attr_class_to_protocol[EAP_MAX];

/*
 *	Default protocol preferences
 */

#define DEF_PREF_DIRECT	    	240	/* Directly connected */
#define DEF_PREF_STATIC		200	/* Static route */
#define DEF_PREF_OSPF_INTERNAL	150	/* OSPF intra-area, inter-area and type 1 external routes */
#define DEF_PREF_RIP		120	/* RIP */
#define DEF_PREF_BGP		100	/* BGP */
#define DEF_PREF_OSPF_EXTERNAL	80	/* OSPF external routes */
#define DEF_PREF_PIPE		70	/* Routes piped from other tables */

#endif