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1 | /* BGP routing table | |
2 | Copyright (C) 1998, 2001 Kunihiro Ishiguro | |
3 | ||
4 | This file is part of GNU Zebra. | |
5 | ||
6 | GNU Zebra is free software; you can redistribute it and/or modify it | |
7 | under the terms of the GNU General Public License as published by the | |
8 | Free Software Foundation; either version 2, or (at your option) any | |
9 | later version. | |
10 | ||
11 | GNU Zebra is distributed in the hope that it will be useful, but | |
12 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GNU Zebra; see the file COPYING. If not, write to the Free | |
18 | Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA | |
19 | 02111-1307, USA. */ | |
20 | ||
21 | #include <zebra.h> | |
22 | ||
23 | #include "prefix.h" | |
24 | #include "memory.h" | |
25 | #include "sockunion.h" | |
26 | #include "vty.h" | |
27 | ||
28 | #include "bgpd/bgpd.h" | |
29 | #include "bgpd/bgp_table.h" | |
30 | ||
31 | void bgp_node_delete (struct bgp_node *); | |
32 | void bgp_table_free (struct bgp_table *); | |
33 | \f | |
34 | struct bgp_table * | |
35 | bgp_table_init (void) | |
36 | { | |
37 | struct bgp_table *rt; | |
38 | ||
39 | rt = XMALLOC (MTYPE_BGP_TABLE, sizeof (struct bgp_table)); | |
40 | memset (rt, 0, sizeof (struct bgp_table)); | |
41 | return rt; | |
42 | } | |
43 | ||
44 | void | |
45 | bgp_table_finish (struct bgp_table *rt) | |
46 | { | |
47 | bgp_table_free (rt); | |
48 | } | |
49 | ||
50 | struct bgp_node * | |
51 | bgp_node_create () | |
52 | { | |
53 | struct bgp_node *rn; | |
54 | ||
55 | rn = (struct bgp_node *) XMALLOC (MTYPE_BGP_NODE, sizeof (struct bgp_node)); | |
56 | memset (rn, 0, sizeof (struct bgp_node)); | |
57 | return rn; | |
58 | } | |
59 | ||
60 | /* Allocate new route node with prefix set. */ | |
61 | struct bgp_node * | |
62 | bgp_node_set (struct bgp_table *table, struct prefix *prefix) | |
63 | { | |
64 | struct bgp_node *node; | |
65 | ||
66 | node = bgp_node_create (); | |
67 | ||
68 | prefix_copy (&node->p, prefix); | |
69 | node->table = table; | |
70 | ||
71 | return node; | |
72 | } | |
73 | ||
74 | /* Free route node. */ | |
75 | void | |
76 | bgp_node_free (struct bgp_node *node) | |
77 | { | |
78 | XFREE (MTYPE_BGP_NODE, node); | |
79 | } | |
80 | ||
81 | /* Free route table. */ | |
82 | void | |
83 | bgp_table_free (struct bgp_table *rt) | |
84 | { | |
85 | struct bgp_node *tmp_node; | |
86 | struct bgp_node *node; | |
87 | ||
88 | if (rt == NULL) | |
89 | return; | |
90 | ||
91 | node = rt->top; | |
92 | ||
93 | while (node) | |
94 | { | |
95 | if (node->l_left) | |
96 | { | |
97 | node = node->l_left; | |
98 | continue; | |
99 | } | |
100 | ||
101 | if (node->l_right) | |
102 | { | |
103 | node = node->l_right; | |
104 | continue; | |
105 | } | |
106 | ||
107 | tmp_node = node; | |
108 | node = node->parent; | |
109 | ||
110 | if (node != NULL) | |
111 | { | |
112 | if (node->l_left == tmp_node) | |
113 | node->l_left = NULL; | |
114 | else | |
115 | node->l_right = NULL; | |
116 | ||
117 | bgp_node_free (tmp_node); | |
118 | } | |
119 | else | |
120 | { | |
121 | bgp_node_free (tmp_node); | |
122 | break; | |
123 | } | |
124 | } | |
125 | ||
126 | XFREE (MTYPE_BGP_TABLE, rt); | |
127 | return; | |
128 | } | |
129 | ||
130 | /* Utility mask array. */ | |
131 | static u_char maskbit[] = | |
132 | { | |
133 | 0x00, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff | |
134 | }; | |
135 | ||
136 | /* Common prefix route genaration. */ | |
137 | static void | |
138 | route_common (struct prefix *n, struct prefix *p, struct prefix *new) | |
139 | { | |
140 | int i; | |
141 | u_char diff; | |
142 | u_char mask; | |
143 | ||
144 | u_char *np = (u_char *)&n->u.prefix; | |
145 | u_char *pp = (u_char *)&p->u.prefix; | |
146 | u_char *newp = (u_char *)&new->u.prefix; | |
147 | ||
148 | for (i = 0; i < p->prefixlen / 8; i++) | |
149 | { | |
150 | if (np[i] == pp[i]) | |
151 | newp[i] = np[i]; | |
152 | else | |
153 | break; | |
154 | } | |
155 | ||
156 | new->prefixlen = i * 8; | |
157 | ||
158 | if (new->prefixlen != p->prefixlen) | |
159 | { | |
160 | diff = np[i] ^ pp[i]; | |
161 | mask = 0x80; | |
162 | while (new->prefixlen < p->prefixlen && !(mask & diff)) | |
163 | { | |
164 | mask >>= 1; | |
165 | new->prefixlen++; | |
166 | } | |
167 | newp[i] = np[i] & maskbit[new->prefixlen % 8]; | |
168 | } | |
169 | } | |
170 | ||
171 | /* Macro version of check_bit (). */ | |
172 | #define CHECK_BIT(X,P) ((((u_char *)(X))[(P) / 8]) >> (7 - ((P) % 8)) & 1) | |
173 | ||
174 | /* Check bit of the prefix. */ | |
175 | static int | |
176 | check_bit (u_char *prefix, u_char prefixlen) | |
177 | { | |
178 | int offset; | |
179 | int shift; | |
180 | u_char *p = (u_char *)prefix; | |
181 | ||
182 | assert (prefixlen <= 128); | |
183 | ||
184 | offset = prefixlen / 8; | |
185 | shift = 7 - (prefixlen % 8); | |
186 | ||
187 | return (p[offset] >> shift & 1); | |
188 | } | |
189 | ||
190 | /* Macro version of set_link (). */ | |
191 | #define SET_LINK(X,Y) (X)->link[CHECK_BIT(&(Y)->prefix,(X)->prefixlen)] = (Y);\ | |
192 | (Y)->parent = (X) | |
193 | ||
194 | static void | |
195 | set_link (struct bgp_node *node, struct bgp_node *new) | |
196 | { | |
197 | int bit; | |
198 | ||
199 | bit = check_bit (&new->p.u.prefix, node->p.prefixlen); | |
200 | ||
201 | assert (bit == 0 || bit == 1); | |
202 | ||
203 | node->link[bit] = new; | |
204 | new->parent = node; | |
205 | } | |
206 | ||
207 | /* Lock node. */ | |
208 | struct bgp_node * | |
209 | bgp_lock_node (struct bgp_node *node) | |
210 | { | |
211 | node->lock++; | |
212 | return node; | |
213 | } | |
214 | ||
215 | /* Unlock node. */ | |
216 | void | |
217 | bgp_unlock_node (struct bgp_node *node) | |
218 | { | |
219 | node->lock--; | |
220 | ||
221 | if (node->lock == 0) | |
222 | bgp_node_delete (node); | |
223 | } | |
224 | ||
225 | /* Find matched prefix. */ | |
226 | struct bgp_node * | |
227 | bgp_node_match (struct bgp_table *table, struct prefix *p) | |
228 | { | |
229 | struct bgp_node *node; | |
230 | struct bgp_node *matched; | |
231 | ||
232 | matched = NULL; | |
233 | node = table->top; | |
234 | ||
235 | /* Walk down tree. If there is matched route then store it to | |
236 | matched. */ | |
237 | while (node && node->p.prefixlen <= p->prefixlen && | |
238 | prefix_match (&node->p, p)) | |
239 | { | |
240 | if (node->info) | |
241 | matched = node; | |
242 | node = node->link[check_bit(&p->u.prefix, node->p.prefixlen)]; | |
243 | } | |
244 | ||
245 | /* If matched route found, return it. */ | |
246 | if (matched) | |
247 | return bgp_lock_node (matched); | |
248 | ||
249 | return NULL; | |
250 | } | |
251 | ||
252 | struct bgp_node * | |
253 | bgp_node_match_ipv4 (struct bgp_table *table, struct in_addr *addr) | |
254 | { | |
255 | struct prefix_ipv4 p; | |
256 | ||
257 | memset (&p, 0, sizeof (struct prefix_ipv4)); | |
258 | p.family = AF_INET; | |
259 | p.prefixlen = IPV4_MAX_PREFIXLEN; | |
260 | p.prefix = *addr; | |
261 | ||
262 | return bgp_node_match (table, (struct prefix *) &p); | |
263 | } | |
264 | ||
265 | #ifdef HAVE_IPV6 | |
266 | struct bgp_node * | |
267 | bgp_node_match_ipv6 (struct bgp_table *table, struct in6_addr *addr) | |
268 | { | |
269 | struct prefix_ipv6 p; | |
270 | ||
271 | memset (&p, 0, sizeof (struct prefix_ipv6)); | |
272 | p.family = AF_INET6; | |
273 | p.prefixlen = IPV6_MAX_PREFIXLEN; | |
274 | p.prefix = *addr; | |
275 | ||
276 | return bgp_node_match (table, (struct prefix *) &p); | |
277 | } | |
278 | #endif /* HAVE_IPV6 */ | |
279 | ||
280 | /* Lookup same prefix node. Return NULL when we can't find route. */ | |
281 | struct bgp_node * | |
282 | bgp_node_lookup (struct bgp_table *table, struct prefix *p) | |
283 | { | |
284 | struct bgp_node *node; | |
285 | ||
286 | node = table->top; | |
287 | ||
288 | while (node && node->p.prefixlen <= p->prefixlen && | |
289 | prefix_match (&node->p, p)) | |
290 | { | |
291 | if (node->p.prefixlen == p->prefixlen && node->info) | |
292 | return bgp_lock_node (node); | |
293 | ||
294 | node = node->link[check_bit(&p->u.prefix, node->p.prefixlen)]; | |
295 | } | |
296 | ||
297 | return NULL; | |
298 | } | |
299 | ||
300 | /* Add node to routing table. */ | |
301 | struct bgp_node * | |
302 | bgp_node_get (struct bgp_table *table, struct prefix *p) | |
303 | { | |
304 | struct bgp_node *new; | |
305 | struct bgp_node *node; | |
306 | struct bgp_node *match; | |
307 | ||
308 | match = NULL; | |
309 | node = table->top; | |
310 | while (node && node->p.prefixlen <= p->prefixlen && | |
311 | prefix_match (&node->p, p)) | |
312 | { | |
313 | if (node->p.prefixlen == p->prefixlen) | |
314 | { | |
315 | bgp_lock_node (node); | |
316 | return node; | |
317 | } | |
318 | match = node; | |
319 | node = node->link[check_bit(&p->u.prefix, node->p.prefixlen)]; | |
320 | } | |
321 | ||
322 | if (node == NULL) | |
323 | { | |
324 | new = bgp_node_set (table, p); | |
325 | if (match) | |
326 | set_link (match, new); | |
327 | else | |
328 | table->top = new; | |
329 | } | |
330 | else | |
331 | { | |
332 | new = bgp_node_create (); | |
333 | route_common (&node->p, p, &new->p); | |
334 | new->p.family = p->family; | |
335 | new->table = table; | |
336 | set_link (new, node); | |
337 | ||
338 | if (match) | |
339 | set_link (match, new); | |
340 | else | |
341 | table->top = new; | |
342 | ||
343 | if (new->p.prefixlen != p->prefixlen) | |
344 | { | |
345 | match = new; | |
346 | new = bgp_node_set (table, p); | |
347 | set_link (match, new); | |
348 | } | |
349 | } | |
350 | bgp_lock_node (new); | |
351 | ||
352 | return new; | |
353 | } | |
354 | ||
355 | /* Delete node from the routing table. */ | |
356 | void | |
357 | bgp_node_delete (struct bgp_node *node) | |
358 | { | |
359 | struct bgp_node *child; | |
360 | struct bgp_node *parent; | |
361 | ||
362 | assert (node->lock == 0); | |
363 | assert (node->info == NULL); | |
364 | ||
365 | if (node->l_left && node->l_right) | |
366 | return; | |
367 | ||
368 | if (node->l_left) | |
369 | child = node->l_left; | |
370 | else | |
371 | child = node->l_right; | |
372 | ||
373 | parent = node->parent; | |
374 | ||
375 | if (child) | |
376 | child->parent = parent; | |
377 | ||
378 | if (parent) | |
379 | { | |
380 | if (parent->l_left == node) | |
381 | parent->l_left = child; | |
382 | else | |
383 | parent->l_right = child; | |
384 | } | |
385 | else | |
386 | node->table->top = child; | |
387 | ||
388 | bgp_node_free (node); | |
389 | ||
390 | /* If parent node is stub then delete it also. */ | |
391 | if (parent && parent->lock == 0) | |
392 | bgp_node_delete (parent); | |
393 | } | |
394 | ||
395 | /* Get fist node and lock it. This function is useful when one want | |
396 | to lookup all the node exist in the routing table. */ | |
397 | struct bgp_node * | |
398 | bgp_table_top (struct bgp_table *table) | |
399 | { | |
400 | /* If there is no node in the routing table return NULL. */ | |
401 | if (table->top == NULL) | |
402 | return NULL; | |
403 | ||
404 | /* Lock the top node and return it. */ | |
405 | bgp_lock_node (table->top); | |
406 | return table->top; | |
407 | } | |
408 | ||
409 | /* Unlock current node and lock next node then return it. */ | |
410 | struct bgp_node * | |
411 | bgp_route_next (struct bgp_node *node) | |
412 | { | |
413 | struct bgp_node *next; | |
414 | struct bgp_node *start; | |
415 | ||
416 | /* Node may be deleted from bgp_unlock_node so we have to preserve | |
417 | next node's pointer. */ | |
418 | ||
419 | if (node->l_left) | |
420 | { | |
421 | next = node->l_left; | |
422 | bgp_lock_node (next); | |
423 | bgp_unlock_node (node); | |
424 | return next; | |
425 | } | |
426 | if (node->l_right) | |
427 | { | |
428 | next = node->l_right; | |
429 | bgp_lock_node (next); | |
430 | bgp_unlock_node (node); | |
431 | return next; | |
432 | } | |
433 | ||
434 | start = node; | |
435 | while (node->parent) | |
436 | { | |
437 | if (node->parent->l_left == node && node->parent->l_right) | |
438 | { | |
439 | next = node->parent->l_right; | |
440 | bgp_lock_node (next); | |
441 | bgp_unlock_node (start); | |
442 | return next; | |
443 | } | |
444 | node = node->parent; | |
445 | } | |
446 | bgp_unlock_node (start); | |
447 | return NULL; | |
448 | } | |
449 | ||
450 | /* Unlock current node and lock next node until limit. */ | |
451 | struct bgp_node * | |
452 | bgp_route_next_until (struct bgp_node *node, struct bgp_node *limit) | |
453 | { | |
454 | struct bgp_node *next; | |
455 | struct bgp_node *start; | |
456 | ||
457 | /* Node may be deleted from bgp_unlock_node so we have to preserve | |
458 | next node's pointer. */ | |
459 | ||
460 | if (node->l_left) | |
461 | { | |
462 | next = node->l_left; | |
463 | bgp_lock_node (next); | |
464 | bgp_unlock_node (node); | |
465 | return next; | |
466 | } | |
467 | if (node->l_right) | |
468 | { | |
469 | next = node->l_right; | |
470 | bgp_lock_node (next); | |
471 | bgp_unlock_node (node); | |
472 | return next; | |
473 | } | |
474 | ||
475 | start = node; | |
476 | while (node->parent && node != limit) | |
477 | { | |
478 | if (node->parent->l_left == node && node->parent->l_right) | |
479 | { | |
480 | next = node->parent->l_right; | |
481 | bgp_lock_node (next); | |
482 | bgp_unlock_node (start); | |
483 | return next; | |
484 | } | |
485 | node = node->parent; | |
486 | } | |
487 | bgp_unlock_node (start); | |
488 | return NULL; | |
489 | } |