f010e4ead64458875a4d97477ad53aa93e4c3fb5
[tinc] / src / subnet.c
1 /*
2     subnet.c -- handle subnet lookups and lists
3     Copyright (C) 2000-2010 Guus Sliepen <guus@tinc-vpn.org>,
4                   2000-2005 Ivo Timmermans
5
6     This program is free software; you can redistribute it and/or modify
7     it under the terms of the GNU General Public License as published by
8     the Free Software Foundation; either version 2 of the License, or
9     (at your option) any later version.
10
11     This program is distributed in the hope that it will be useful,
12     but WITHOUT ANY WARRANTY; without even the implied warranty of
13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14     GNU General Public License for more details.
15
16     You should have received a copy of the GNU General Public License along
17     with this program; if not, write to the Free Software Foundation, Inc.,
18     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19 */
20
21 #include "system.h"
22
23 #include "avl_tree.h"
24 #include "device.h"
25 #include "logger.h"
26 #include "net.h"
27 #include "netutl.h"
28 #include "node.h"
29 #include "process.h"
30 #include "subnet.h"
31 #include "utils.h"
32 #include "xalloc.h"
33
34 /* lists type of subnet */
35
36 avl_tree_t *subnet_tree;
37
38 /* Subnet lookup cache */
39
40 static ipv4_t cache_ipv4_address[2];
41 static subnet_t *cache_ipv4_subnet[2];
42 static bool cache_ipv4_valid[2];
43 static int cache_ipv4_slot;
44
45 static ipv6_t cache_ipv6_address[2];
46 static subnet_t *cache_ipv6_subnet[2];
47 static bool cache_ipv6_valid[2];
48 static int cache_ipv6_slot;
49
50 static mac_t cache_mac_address[2];
51 static subnet_t *cache_mac_subnet[2];
52 static bool cache_mac_valid[2];
53 static int cache_mac_slot;
54
55 void subnet_cache_flush(void) {
56         cache_ipv4_valid[0] = cache_ipv4_valid[1] = false;
57         cache_ipv6_valid[0] = cache_ipv6_valid[1] = false;
58         cache_mac_valid[0] = cache_mac_valid[1] = false;
59 }
60
61 /* Subnet comparison */
62
63 static int subnet_compare_mac(const subnet_t *a, const subnet_t *b) {
64         int result;
65
66         result = memcmp(&a->net.mac.address, &b->net.mac.address, sizeof(mac_t));
67
68         if(result)
69                 return result;
70         
71         result = a->weight - b->weight;
72
73         if(result || !a->owner || !b->owner)
74                 return result;
75
76         return strcmp(a->owner->name, b->owner->name);
77 }
78
79 static int subnet_compare_ipv4(const subnet_t *a, const subnet_t *b) {
80         int result;
81
82         result = b->net.ipv4.prefixlength - a->net.ipv4.prefixlength;
83
84         if(result)
85                 return result;
86
87         result = memcmp(&a->net.ipv4.address, &b->net.ipv4.address, sizeof(ipv4_t));
88
89         if(result)
90                 return result;
91         
92         result = a->weight - b->weight;
93
94         if(result || !a->owner || !b->owner)
95                 return result;
96
97         return strcmp(a->owner->name, b->owner->name);
98 }
99
100 static int subnet_compare_ipv6(const subnet_t *a, const subnet_t *b) {
101         int result;
102
103         result = b->net.ipv6.prefixlength - a->net.ipv6.prefixlength;
104
105         if(result)
106                 return result;
107         
108         result = memcmp(&a->net.ipv6.address, &b->net.ipv6.address, sizeof(ipv6_t));
109
110         if(result)
111                 return result;
112         
113         result = a->weight - b->weight;
114
115         if(result || !a->owner || !b->owner)
116                 return result;
117
118         return strcmp(a->owner->name, b->owner->name);
119 }
120
121 int subnet_compare(const subnet_t *a, const subnet_t *b) {
122         int result;
123
124         result = a->type - b->type;
125
126         if(result)
127                 return result;
128
129         switch (a->type) {
130         case SUBNET_MAC:
131                 return subnet_compare_mac(a, b);
132         case SUBNET_IPV4:
133                 return subnet_compare_ipv4(a, b);
134         case SUBNET_IPV6:
135                 return subnet_compare_ipv6(a, b);
136         default:
137                 logger(LOG_ERR, "subnet_compare() was called with unknown subnet type %d, exitting!",
138                            a->type);
139                 exit(0);
140         }
141
142         return 0;
143 }
144
145 /* Initialising trees */
146
147 void init_subnets(void) {
148         subnet_tree = avl_alloc_tree((avl_compare_t) subnet_compare, (avl_action_t) free_subnet);
149
150         subnet_cache_flush();
151 }
152
153 void exit_subnets(void) {
154         avl_delete_tree(subnet_tree);
155 }
156
157 avl_tree_t *new_subnet_tree(void) {
158         return avl_alloc_tree((avl_compare_t) subnet_compare, NULL);
159 }
160
161 void free_subnet_tree(avl_tree_t *subnet_tree) {
162         avl_delete_tree(subnet_tree);
163 }
164
165 /* Allocating and freeing space for subnets */
166
167 subnet_t *new_subnet(void) {
168         return xmalloc_and_zero(sizeof(subnet_t));
169 }
170
171 void free_subnet(subnet_t *subnet) {
172         free(subnet);
173 }
174
175 /* Adding and removing subnets */
176
177 void subnet_add(node_t *n, subnet_t *subnet) {
178         subnet->owner = n;
179
180         avl_insert(subnet_tree, subnet);
181         avl_insert(n->subnet_tree, subnet);
182
183         subnet_cache_flush();
184 }
185
186 void subnet_del(node_t *n, subnet_t *subnet) {
187         avl_delete(n->subnet_tree, subnet);
188         avl_delete(subnet_tree, subnet);
189
190         subnet_cache_flush();
191 }
192
193 /* Ascii representation of subnets */
194
195 bool str2net(subnet_t *subnet, const char *subnetstr) {
196         int i, l;
197         uint16_t x[8];
198         int weight = 10;
199
200         if(sscanf(subnetstr, "%hu.%hu.%hu.%hu/%d#%d",
201                           &x[0], &x[1], &x[2], &x[3], &l, &weight) >= 5) {
202                 if(l < 0 || l > 32)
203                         return false;
204
205                 subnet->type = SUBNET_IPV4;
206                 subnet->net.ipv4.prefixlength = l;
207                 subnet->weight = weight;
208
209                 for(i = 0; i < 4; i++) {
210                         if(x[i] > 255)
211                                 return false;
212                         subnet->net.ipv4.address.x[i] = x[i];
213                 }
214
215                 return true;
216         }
217
218         if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d#%d",
219                           &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7],
220                           &l, &weight) >= 9) {
221                 if(l < 0 || l > 128)
222                         return false;
223
224                 subnet->type = SUBNET_IPV6;
225                 subnet->net.ipv6.prefixlength = l;
226                 subnet->weight = weight;
227
228                 for(i = 0; i < 8; i++)
229                         subnet->net.ipv6.address.x[i] = htons(x[i]);
230
231                 return true;
232         }
233
234         if(sscanf(subnetstr, "%hu.%hu.%hu.%hu#%d", &x[0], &x[1], &x[2], &x[3], &weight) >= 4) {
235                 subnet->type = SUBNET_IPV4;
236                 subnet->net.ipv4.prefixlength = 32;
237                 subnet->weight = weight;
238
239                 for(i = 0; i < 4; i++) {
240                         if(x[i] > 255)
241                                 return false;
242                         subnet->net.ipv4.address.x[i] = x[i];
243                 }
244
245                 return true;
246         }
247
248         if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx#%d",
249                           &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7], &weight) >= 8) {
250                 subnet->type = SUBNET_IPV6;
251                 subnet->net.ipv6.prefixlength = 128;
252                 subnet->weight = weight;
253
254                 for(i = 0; i < 8; i++)
255                         subnet->net.ipv6.address.x[i] = htons(x[i]);
256
257                 return true;
258         }
259
260         if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx#%d",
261                           &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &weight) >= 6) {
262                 subnet->type = SUBNET_MAC;
263                 subnet->weight = weight;
264
265                 for(i = 0; i < 6; i++)
266                         subnet->net.mac.address.x[i] = x[i];
267
268                 return true;
269         }
270
271         return false;
272 }
273
274 bool net2str(char *netstr, int len, const subnet_t *subnet) {
275         if(!netstr || !subnet) {
276                 logger(LOG_ERR, "net2str() was called with netstr=%p, subnet=%p!\n", netstr, subnet);
277                 return false;
278         }
279
280         switch (subnet->type) {
281                 case SUBNET_MAC:
282                         snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx#%d",
283                                          subnet->net.mac.address.x[0],
284                                          subnet->net.mac.address.x[1],
285                                          subnet->net.mac.address.x[2],
286                                          subnet->net.mac.address.x[3],
287                                          subnet->net.mac.address.x[4],
288                                          subnet->net.mac.address.x[5],
289                                          subnet->weight);
290                         break;
291
292                 case SUBNET_IPV4:
293                         snprintf(netstr, len, "%hu.%hu.%hu.%hu/%d#%d",
294                                          subnet->net.ipv4.address.x[0],
295                                          subnet->net.ipv4.address.x[1],
296                                          subnet->net.ipv4.address.x[2],
297                                          subnet->net.ipv4.address.x[3],
298                                          subnet->net.ipv4.prefixlength,
299                                          subnet->weight);
300                         break;
301
302                 case SUBNET_IPV6:
303                         snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d#%d",
304                                          ntohs(subnet->net.ipv6.address.x[0]),
305                                          ntohs(subnet->net.ipv6.address.x[1]),
306                                          ntohs(subnet->net.ipv6.address.x[2]),
307                                          ntohs(subnet->net.ipv6.address.x[3]),
308                                          ntohs(subnet->net.ipv6.address.x[4]),
309                                          ntohs(subnet->net.ipv6.address.x[5]),
310                                          ntohs(subnet->net.ipv6.address.x[6]),
311                                          ntohs(subnet->net.ipv6.address.x[7]),
312                                          subnet->net.ipv6.prefixlength,
313                                          subnet->weight);
314                         break;
315
316                 default:
317                         logger(LOG_ERR,
318                                    "net2str() was called with unknown subnet type %d, exiting!",
319                                    subnet->type);
320                         exit(0);
321         }
322
323         return true;
324 }
325
326 /* Subnet lookup routines */
327
328 subnet_t *lookup_subnet(const node_t *owner, const subnet_t *subnet) {
329         return avl_search(owner->subnet_tree, subnet);
330 }
331
332 subnet_t *lookup_subnet_mac(const node_t *owner, const mac_t *address) {
333         subnet_t *p, *r = NULL;
334         avl_node_t *n;
335         int i;
336
337         // Check if this address is cached
338
339         for(i = 0; i < 2; i++) {
340                 if(!cache_mac_valid[i])
341                         continue;
342                 if(owner && cache_mac_subnet[i] && cache_mac_subnet[i]->owner != owner)
343                         continue;
344                 if(!memcmp(address, &cache_mac_address[i], sizeof *address))
345                         return cache_mac_subnet[i];
346         }
347
348         // Search all subnets for a matching one
349
350         for(n = owner ? owner->subnet_tree->head : subnet_tree->head; n; n = n->next) {
351                 p = n->data;
352                 
353                 if(!p || p->type != SUBNET_MAC)
354                         continue;
355
356                 if(!memcmp(address, &p->net.mac.address, sizeof *address)) {
357                         r = p;
358                         if(p->owner->status.reachable)
359                                 break;
360                 }
361         }
362
363         // Cache the result
364
365         cache_mac_slot = !cache_mac_slot;
366         memcpy(&cache_mac_address[cache_mac_slot], address, sizeof *address);
367         cache_mac_subnet[cache_mac_slot] = r;
368         cache_mac_valid[cache_mac_slot] = true;
369
370         return r;
371 }
372
373 subnet_t *lookup_subnet_ipv4(const ipv4_t *address) {
374         subnet_t *p, *r = NULL;
375         avl_node_t *n;
376         int i;
377
378         // Check if this address is cached
379
380         for(i = 0; i < 2; i++) {
381                 if(!cache_ipv4_valid[i])
382                         continue;
383                 if(!memcmp(address, &cache_ipv4_address[i], sizeof *address))
384                         return cache_ipv4_subnet[i];
385         }
386
387         // Search all subnets for a matching one
388
389         for(n = subnet_tree->head; n; n = n->next) {
390                 p = n->data;
391                 
392                 if(!p || p->type != SUBNET_IPV4)
393                         continue;
394
395                 if(!maskcmp(address, &p->net.ipv4.address, p->net.ipv4.prefixlength)) {
396                         r = p;
397                         if(p->owner->status.reachable)
398                                 break;
399                 }
400         }
401
402         // Cache the result
403
404         cache_ipv4_slot = !cache_ipv4_slot;
405         memcpy(&cache_ipv4_address[cache_ipv4_slot], address, sizeof *address);
406         cache_ipv4_subnet[cache_ipv4_slot] = r;
407         cache_ipv4_valid[cache_ipv4_slot] = true;
408
409         return r;
410 }
411
412 subnet_t *lookup_subnet_ipv6(const ipv6_t *address) {
413         subnet_t *p, *r = NULL;
414         avl_node_t *n;
415         int i;
416
417         // Check if this address is cached
418
419         for(i = 0; i < 2; i++) {
420                 if(!cache_ipv6_valid[i])
421                         continue;
422                 if(!memcmp(address, &cache_ipv6_address[i], sizeof *address))
423                         return cache_ipv6_subnet[i];
424         }
425
426         // Search all subnets for a matching one
427
428         for(n = subnet_tree->head; n; n = n->next) {
429                 p = n->data;
430                 
431                 if(!p || p->type != SUBNET_IPV6)
432                         continue;
433
434                 if(!maskcmp(address, &p->net.ipv6.address, p->net.ipv6.prefixlength)) {
435                         r = p;
436                         if(p->owner->status.reachable)
437                                 break;
438                 }
439         }
440
441         // Cache the result
442
443         cache_ipv6_slot = !cache_ipv6_slot;
444         memcpy(&cache_ipv6_address[cache_ipv6_slot], address, sizeof *address);
445         cache_ipv6_subnet[cache_ipv6_slot] = r;
446         cache_ipv6_valid[cache_ipv6_slot] = true;
447
448         return r;
449 }
450
451 void subnet_update(node_t *owner, subnet_t *subnet, bool up) {
452         avl_node_t *node;
453         int i;
454         char *envp[9] = {NULL};
455         char netstr[MAXNETSTR];
456         char *name, *address, *port;
457         char empty[] = "";
458
459         // Prepare environment variables to be passed to the script
460
461         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
462         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
463         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
464         xasprintf(&envp[3], "NODE=%s", owner->name);
465
466         if(owner != myself) {
467                 sockaddr2str(&owner->address, &address, &port);
468                 // 4 and 5 are reserved for SUBNET and WEIGHT
469                 xasprintf(&envp[6], "REMOTEADDRESS=%s", address);
470                 xasprintf(&envp[7], "REMOTEPORT=%s", port);
471         }
472
473         name = up ? "subnet-up" : "subnet-down";
474
475         if(!subnet) {
476                 for(node = owner->subnet_tree->head; node; node = node->next) {
477                         subnet = node->data;
478                         if(!net2str(netstr, sizeof netstr, subnet))
479                                 continue;
480                         // Strip the weight from the subnet, and put it in its own environment variable
481                         char *weight = strchr(netstr, '#');
482                         if(weight)
483                                 *weight++ = 0;
484                         else
485                                 weight = empty;
486
487                         // Prepare the SUBNET and WEIGHT variables
488                         if(envp[4])
489                                 free(envp[4]);
490                         if(envp[5])
491                                 free(envp[5]);
492                         xasprintf(&envp[4], "SUBNET=%s", netstr);
493                         xasprintf(&envp[5], "WEIGHT=%s", weight);
494
495                         execute_script(name, envp);
496                 }
497         } else {
498                 if(net2str(netstr, sizeof netstr, subnet)) {
499                         // Strip the weight from the subnet, and put it in its own environment variable
500                         char *weight = strchr(netstr, '#');
501                         if(weight)
502                                 *weight++ = 0;
503                         else
504                                 weight = empty;
505
506                         // Prepare the SUBNET and WEIGHT variables
507                         xasprintf(&envp[4], "SUBNET=%s", netstr);
508                         xasprintf(&envp[5], "WEIGHT=%s", weight);
509
510                         execute_script(name, envp);
511                 }
512         }
513
514         for(i = 0; envp[i] && i < 9; i++)
515                 free(envp[i]);
516 }
517
518 void dump_subnets(void) {
519         char netstr[MAXNETSTR];
520         subnet_t *subnet;
521         avl_node_t *node;
522
523         logger(LOG_DEBUG, "Subnet list:");
524
525         for(node = subnet_tree->head; node; node = node->next) {
526                 subnet = node->data;
527                 if(!net2str(netstr, sizeof netstr, subnet))
528                         continue;
529                 logger(LOG_DEBUG, " %s owner %s", netstr, subnet->owner->name);
530         }
531
532         logger(LOG_DEBUG, "End of subnet list.");
533 }