Fix generation of version_git.h for some versions of BSD make.
[tinc] / src / protocol_edge.c
1 /*
2     protocol_edge.c -- handle the meta-protocol, edges
3     Copyright (C) 1999-2005 Ivo Timmermans,
4                   2000-2012 Guus Sliepen <guus@tinc-vpn.org>
5                   2009      Michael Tokarev <mjt@corpit.ru>
6
7     This program is free software; you can redistribute it and/or modify
8     it under the terms of the GNU General Public License as published by
9     the Free Software Foundation; either version 2 of the License, or
10     (at your option) any later version.
11
12     This program is distributed in the hope that it will be useful,
13     but WITHOUT ANY WARRANTY; without even the implied warranty of
14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15     GNU General Public License for more details.
16
17     You should have received a copy of the GNU General Public License along
18     with this program; if not, write to the Free Software Foundation, Inc.,
19     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
20 */
21
22 #include "system.h"
23
24 #include "conf.h"
25 #include "connection.h"
26 #include "edge.h"
27 #include "graph.h"
28 #include "logger.h"
29 #include "meta.h"
30 #include "net.h"
31 #include "netutl.h"
32 #include "node.h"
33 #include "protocol.h"
34 #include "utils.h"
35 #include "xalloc.h"
36
37 bool send_add_edge(connection_t *c, const edge_t *e) {
38         bool x;
39         char *address, *port;
40
41         sockaddr2str(&e->address, &address, &port);
42
43         if(e->local_address.sa.sa_family) {
44                 char *local_address, *local_port;
45                 sockaddr2str(&e->local_address, &local_address, &local_port);
46
47                 x = send_request(c, "%d %x %s %s %s %s %x %d %s %s", ADD_EDGE, rand(),
48                                                  e->from->name, e->to->name, address, port,
49                                                  e->options, e->weight, local_address, local_port);
50                 free(local_address);
51                 free(local_port);
52         } else {
53                 x = send_request(c, "%d %x %s %s %s %s %x %d", ADD_EDGE, rand(),
54                                                  e->from->name, e->to->name, address, port,
55                                                  e->options, e->weight);
56         }
57
58         free(address);
59         free(port);
60
61         return x;
62 }
63
64 bool add_edge_h(connection_t *c, const char *request) {
65         edge_t *e;
66         node_t *from, *to;
67         char from_name[MAX_STRING_SIZE];
68         char to_name[MAX_STRING_SIZE];
69         char to_address[MAX_STRING_SIZE];
70         char to_port[MAX_STRING_SIZE];
71         char address_local[MAX_STRING_SIZE];
72         char port_local[MAX_STRING_SIZE];
73         sockaddr_t address, local_address = {{0}};
74         uint32_t options;
75         int weight;
76
77         int parameter_count = sscanf(request, "%*d %*x "MAX_STRING" "MAX_STRING" "MAX_STRING" "MAX_STRING" %x %d "MAX_STRING" "MAX_STRING,
78                                               from_name, to_name, to_address, to_port, &options, &weight, address_local, port_local);
79         if (parameter_count != 6 && parameter_count != 8) {
80                 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "ADD_EDGE", c->name,
81                            c->hostname);
82                 return false;
83         }
84
85         /* Check if names are valid */
86
87         if(!check_id(from_name) || !check_id(to_name)) {
88                 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "ADD_EDGE", c->name,
89                            c->hostname, "invalid name");
90                 return false;
91         }
92
93         if(seen_request(request))
94                 return true;
95
96         /* Lookup nodes */
97
98         from = lookup_node(from_name);
99         to = lookup_node(to_name);
100
101         if(tunnelserver &&
102            from != myself && from != c->node &&
103            to != myself && to != c->node) {
104                 /* ignore indirect edge registrations for tunnelserver */
105                 logger(DEBUG_PROTOCOL, LOG_WARNING,
106                    "Ignoring indirect %s from %s (%s)",
107                    "ADD_EDGE", c->name, c->hostname);
108                 return true;
109         }
110
111         if(!from) {
112                 from = new_node();
113                 from->name = xstrdup(from_name);
114                 node_add(from);
115         }
116
117         if(!to) {
118                 to = new_node();
119                 to->name = xstrdup(to_name);
120                 node_add(to);
121         }
122
123
124         /* Convert addresses */
125
126         address = str2sockaddr(to_address, to_port);
127         if(parameter_count >= 8)
128                 local_address = str2sockaddr(address_local, port_local);
129
130         /* Check if edge already exists */
131
132         e = lookup_edge(from, to);
133
134         if(e) {
135                 if(e->weight != weight || e->options != options || sockaddrcmp(&e->address, &address)) {
136                         if(from == myself) {
137                                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) for ourself which does not match existing entry",
138                                                    "ADD_EDGE", c->name, c->hostname);
139                                 send_add_edge(c, e);
140                                 sockaddrfree(&local_address);
141                                 return true;
142                         } else {
143                                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) which does not match existing entry",
144                                                    "ADD_EDGE", c->name, c->hostname);
145                                 e->options = options;
146                                 if(sockaddrcmp(&e->address, &address)) {
147                                         sockaddrfree(&e->address);
148                                         e->address = address;
149                                 }
150                                 if(e->weight != weight) {
151                                         splay_node_t *node = splay_unlink(edge_weight_tree, e);
152                                         e->weight = weight;
153                                         splay_insert_node(edge_weight_tree, node);
154                                 }
155
156                                 goto done;
157                         }
158                 } else if(sockaddrcmp(&e->local_address, &local_address)) {
159                         if(from == myself) {
160                                 if(e->local_address.sa.sa_family && local_address.sa.sa_family) {
161                                         // Someone has the wrong local address for ourself. Correct then.
162                                         logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) for ourself which does not match existing entry",
163                                                            "ADD_EDGE", c->name, c->hostname);
164                                         send_add_edge(c, e);
165                                         sockaddrfree(&local_address);
166                                         return true;
167                                 }
168                                 // Otherwise, just ignore it.
169                                 sockaddrfree(&local_address);
170                                 return true;
171                         } else if(local_address.sa.sa_family && local_address.sa.sa_family != AF_UNKNOWN) {
172                                 // We learned a new local address for this edge.
173                                 // local_address.sa.sa_family will be 0 if we got it from older tinc versions
174                                 // local_address.sa.sa_family will be 255 (AF_UNKNOWN) if we got it from newer versions
175                                 // but for edge which does not have local_address
176                                 sockaddrfree(&e->local_address);
177                                 e->local_address = local_address;
178
179                                 // Tell others about it.
180                                 if(!tunnelserver)
181                                         forward_request(c, request);
182
183                                 return true;
184                         } else {
185                                 sockaddrfree(&local_address);
186                                 return true;
187                         }
188                 } else {
189                         sockaddrfree(&local_address);
190                         return true;
191                 }
192         } else if(from == myself) {
193                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) for ourself which does not exist",
194                                    "ADD_EDGE", c->name, c->hostname);
195                 contradicting_add_edge++;
196                 e = new_edge();
197                 e->from = from;
198                 e->to = to;
199                 send_del_edge(c, e);
200                 free_edge(e);
201                 sockaddrfree(&local_address);
202                 return true;
203         }
204
205         e = new_edge();
206         e->from = from;
207         e->to = to;
208         e->address = address;
209         e->local_address = local_address;
210         e->options = options;
211         e->weight = weight;
212         edge_add(e);
213
214 done:
215         /* Tell the rest about the new edge */
216
217         if(!tunnelserver)
218                 forward_request(c, request);
219
220         /* Run MST before or after we tell the rest? */
221
222         graph();
223
224         return true;
225 }
226
227 bool send_del_edge(connection_t *c, const edge_t *e) {
228         return send_request(c, "%d %x %s %s", DEL_EDGE, rand(),
229                                                 e->from->name, e->to->name);
230 }
231
232 bool del_edge_h(connection_t *c, const char *request) {
233         edge_t *e;
234         char from_name[MAX_STRING_SIZE];
235         char to_name[MAX_STRING_SIZE];
236         node_t *from, *to;
237
238         if(sscanf(request, "%*d %*x "MAX_STRING" "MAX_STRING, from_name, to_name) != 2) {
239                 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "DEL_EDGE", c->name,
240                            c->hostname);
241                 return false;
242         }
243
244         /* Check if names are valid */
245
246         if(!check_id(from_name) || !check_id(to_name)) {
247                 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "DEL_EDGE", c->name,
248                            c->hostname, "invalid name");
249                 return false;
250         }
251
252         if(seen_request(request))
253                 return true;
254
255         /* Lookup nodes */
256
257         from = lookup_node(from_name);
258         to = lookup_node(to_name);
259
260         if(tunnelserver &&
261            from != myself && from != c->node &&
262            to != myself && to != c->node) {
263                 /* ignore indirect edge registrations for tunnelserver */
264                 logger(DEBUG_PROTOCOL, LOG_WARNING,
265                    "Ignoring indirect %s from %s (%s)",
266                    "DEL_EDGE", c->name, c->hostname);
267                 return true;
268         }
269
270         if(!from) {
271                 logger(DEBUG_PROTOCOL, LOG_ERR, "Got %s from %s (%s) which does not appear in the edge tree",
272                                    "DEL_EDGE", c->name, c->hostname);
273                 return true;
274         }
275
276         if(!to) {
277                 logger(DEBUG_PROTOCOL, LOG_ERR, "Got %s from %s (%s) which does not appear in the edge tree",
278                                    "DEL_EDGE", c->name, c->hostname);
279                 return true;
280         }
281
282         /* Check if edge exists */
283
284         e = lookup_edge(from, to);
285
286         if(!e) {
287                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) which does not appear in the edge tree",
288                                    "DEL_EDGE", c->name, c->hostname);
289                 return true;
290         }
291
292         if(e->from == myself) {
293                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) for ourself",
294                                    "DEL_EDGE", c->name, c->hostname);
295                 contradicting_del_edge++;
296                 send_add_edge(c, e);    /* Send back a correction */
297                 return true;
298         }
299
300         /* Tell the rest about the deleted edge */
301
302         if(!tunnelserver)
303                 forward_request(c, request);
304
305         /* Delete the edge */
306
307         edge_del(e);
308
309         /* Run MST before or after we tell the rest? */
310
311         graph();
312
313         /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
314
315         if(!to->status.reachable) {
316                 e = lookup_edge(to, myself);
317                 if(e) {
318                         if(!tunnelserver)
319                                 send_del_edge(everyone, e);
320                         edge_del(e);
321                 }
322         }
323
324         return true;
325 }