-
Notifications
You must be signed in to change notification settings - Fork 73
/
helper.c
480 lines (420 loc) · 13.4 KB
/
helper.c
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
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
/*
* OpenVPN -- An application to securely tunnel IP networks
* over a single TCP/UDP port, with support for SSL/TLS-based
* session authentication and key exchange,
* packet encryption, packet authentication, and
* packet compression.
*
* Copyright (C) 2002-2009 OpenVPN Technologies, Inc. <[email protected]>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (see the file COPYING included with this
* distribution); if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "syshead.h"
#include "forward.h"
#include "helper.h"
#include "pool.h"
#include "push.h"
#include "memdbg.h"
#if P2MP_SERVER
static const char *
print_netmask (int netbits, struct gc_arena *gc)
{
struct buffer out = alloc_buf_gc (128, gc);
const in_addr_t netmask = netbits_to_netmask (netbits);
buf_printf (&out, "%s (/%d)", print_in_addr_t (netmask, 0, gc), netbits);
return BSTR (&out);
}
static const char *
print_opt_route_gateway (const in_addr_t route_gateway, struct gc_arena *gc)
{
struct buffer out = alloc_buf_gc (128, gc);
ASSERT (route_gateway);
buf_printf (&out, "route-gateway %s", print_in_addr_t (route_gateway, 0, gc));
return BSTR (&out);
}
static const char *
print_opt_route_gateway_dhcp (struct gc_arena *gc)
{
struct buffer out = alloc_buf_gc (32, gc);
buf_printf (&out, "route-gateway dhcp");
return BSTR (&out);
}
static const char *
print_opt_route (const in_addr_t network, const in_addr_t netmask, struct gc_arena *gc)
{
struct buffer out = alloc_buf_gc (128, gc);
ASSERT (network);
if (netmask)
buf_printf (&out, "route %s %s",
print_in_addr_t (network, 0, gc),
print_in_addr_t (netmask, 0, gc));
else
buf_printf (&out, "route %s",
print_in_addr_t (network, 0, gc));
return BSTR (&out);
}
static const char *
print_opt_topology (const int topology, struct gc_arena *gc)
{
struct buffer out = alloc_buf_gc (128, gc);
buf_printf (&out, "topology %s", print_topology (topology));
return BSTR (&out);
}
static const char *
print_str_int (const char *str, const int i, struct gc_arena *gc)
{
struct buffer out = alloc_buf_gc (128, gc);
buf_printf (&out, "%s %d", str, i);
return BSTR (&out);
}
static const char *
print_str (const char *str, struct gc_arena *gc)
{
struct buffer out = alloc_buf_gc (128, gc);
buf_printf (&out, "%s", str);
return BSTR (&out);
}
static void
helper_add_route (const in_addr_t network, const in_addr_t netmask, struct options *o)
{
rol_check_alloc (o);
add_route_to_option_list (o->routes,
print_in_addr_t (network, 0, &o->gc),
print_in_addr_t (netmask, 0, &o->gc),
NULL,
NULL);
}
static void
verify_common_subnet (const char *opt, const in_addr_t a, const in_addr_t b, const in_addr_t subnet)
{
struct gc_arena gc = gc_new ();
if ((a & subnet) != (b & subnet))
msg (M_USAGE, "%s IP addresses %s and %s are not in the same %s subnet",
opt,
print_in_addr_t (a, 0, &gc),
print_in_addr_t (b, 0, &gc),
print_in_addr_t (subnet, 0, &gc));
gc_free (&gc);
}
#endif
/*
* Process server, server-bridge, and client helper
* directives after the parameters themselves have been
* parsed and placed in struct options.
*/
void
helper_client_server (struct options *o)
{
struct gc_arena gc = gc_new ();
#if P2MP
#if P2MP_SERVER
/*
*
* HELPER DIRECTIVE:
*
* server 10.8.0.0 255.255.255.0
*
* EXPANDS TO:
*
* mode server
* tls-server
* push "topology [topology]"
*
* if tun AND (topology == net30 OR topology == p2p):
* ifconfig 10.8.0.1 10.8.0.2
* if !nopool:
* ifconfig-pool 10.8.0.4 10.8.0.251
* route 10.8.0.0 255.255.255.0
* if client-to-client:
* push "route 10.8.0.0 255.255.255.0"
* else if topology == net30:
* push "route 10.8.0.1"
*
* if tap OR (tun AND topology == subnet):
* ifconfig 10.8.0.1 255.255.255.0
* if !nopool:
* ifconfig-pool 10.8.0.2 10.8.0.254 255.255.255.0
* push "route-gateway 10.8.0.1"
*/
/*
* Get tun/tap/null device type
*/
const int dev = dev_type_enum (o->dev, o->dev_type);
const int topology = o->topology;
if (o->server_defined)
{
int netbits = -2;
bool status = false;
if (o->client)
msg (M_USAGE, "--server and --client cannot be used together");
if (o->server_bridge_defined || o->server_bridge_proxy_dhcp)
msg (M_USAGE, "--server and --server-bridge cannot be used together");
if (o->shared_secret_file)
msg (M_USAGE, "--server and --secret cannot be used together (you must use SSL/TLS keys)");
if (!(o->server_flags & SF_NOPOOL) && o->ifconfig_pool_defined)
msg (M_USAGE, "--server already defines an ifconfig-pool, so you can't also specify --ifconfig-pool explicitly");
if (!(dev == DEV_TYPE_TAP || dev == DEV_TYPE_TUN))
msg (M_USAGE, "--server directive only makes sense with --dev tun or --dev tap");
status = netmask_to_netbits (o->server_network, o->server_netmask, &netbits);
if (!status)
msg (M_USAGE, "--server directive network/netmask combination is invalid");
if (netbits < 0)
msg (M_USAGE, "--server directive netmask is invalid");
if (netbits < IFCONFIG_POOL_MIN_NETBITS)
msg (M_USAGE, "--server directive netmask allows for too many host addresses (subnet must be %s or higher)",
print_netmask (IFCONFIG_POOL_MIN_NETBITS, &gc));
if (dev == DEV_TYPE_TUN)
{
int pool_end_reserve = 4;
if (netbits > 29)
msg (M_USAGE, "--server directive when used with --dev tun must define a subnet of %s or lower",
print_netmask (29, &gc));
if (netbits == 29)
pool_end_reserve = 0;
o->mode = MODE_SERVER;
o->tls_server = true;
if (topology == TOP_NET30 || topology == TOP_P2P)
{
o->ifconfig_local = print_in_addr_t (o->server_network + 1, 0, &o->gc);
o->ifconfig_remote_netmask = print_in_addr_t (o->server_network + 2, 0, &o->gc);
if (!(o->server_flags & SF_NOPOOL))
{
o->ifconfig_pool_defined = true;
o->ifconfig_pool_start = o->server_network + 4;
o->ifconfig_pool_end = (o->server_network | ~o->server_netmask) - pool_end_reserve;
ifconfig_pool_verify_range (M_USAGE, o->ifconfig_pool_start, o->ifconfig_pool_end);
}
helper_add_route (o->server_network, o->server_netmask, o);
if (o->enable_c2c)
push_option (o, print_opt_route (o->server_network, o->server_netmask, &o->gc), M_USAGE);
else if (topology == TOP_NET30)
push_option (o, print_opt_route (o->server_network + 1, 0, &o->gc), M_USAGE);
}
else if (topology == TOP_SUBNET)
{
o->ifconfig_local = print_in_addr_t (o->server_network + 1, 0, &o->gc);
o->ifconfig_remote_netmask = print_in_addr_t (o->server_netmask, 0, &o->gc);
if (!(o->server_flags & SF_NOPOOL))
{
o->ifconfig_pool_defined = true;
o->ifconfig_pool_start = o->server_network + 2;
o->ifconfig_pool_end = (o->server_network | ~o->server_netmask) - 2;
ifconfig_pool_verify_range (M_USAGE, o->ifconfig_pool_start, o->ifconfig_pool_end);
}
o->ifconfig_pool_netmask = o->server_netmask;
push_option (o, print_opt_route_gateway (o->server_network + 1, &o->gc), M_USAGE);
}
else
ASSERT (0);
push_option (o, print_opt_topology (topology, &o->gc), M_USAGE);
}
else if (dev == DEV_TYPE_TAP)
{
if (netbits > 30)
msg (M_USAGE, "--server directive when used with --dev tap must define a subnet of %s or lower",
print_netmask (30, &gc));
o->mode = MODE_SERVER;
o->tls_server = true;
o->ifconfig_local = print_in_addr_t (o->server_network + 1, 0, &o->gc);
o->ifconfig_remote_netmask = print_in_addr_t (o->server_netmask, 0, &o->gc);
if (!(o->server_flags & SF_NOPOOL))
{
o->ifconfig_pool_defined = true;
o->ifconfig_pool_start = o->server_network + 2;
o->ifconfig_pool_end = (o->server_network | ~o->server_netmask) - 1;
ifconfig_pool_verify_range (M_USAGE, o->ifconfig_pool_start, o->ifconfig_pool_end);
}
o->ifconfig_pool_netmask = o->server_netmask;
push_option (o, print_opt_route_gateway (o->server_network + 1, &o->gc), M_USAGE);
}
else
{
ASSERT (0);
}
/* set push-ifconfig-constraint directive */
if ((dev == DEV_TYPE_TAP || topology == TOP_SUBNET))
{
o->push_ifconfig_constraint_defined = true;
o->push_ifconfig_constraint_network = o->server_network;
o->push_ifconfig_constraint_netmask = o->server_netmask;
}
}
/*
* HELPER DIRECTIVE:
*
* server-bridge 10.8.0.4 255.255.255.0 10.8.0.128 10.8.0.254
*
* EXPANDS TO:
*
* mode server
* tls-server
*
* ifconfig-pool 10.8.0.128 10.8.0.254 255.255.255.0
* push "route-gateway 10.8.0.4"
*
* OR
*
* server-bridge
*
* EXPANDS TO:
*
* mode server
* tls-server
*
* if !nogw:
* push "route-gateway dhcp"
*/
else if (o->server_bridge_defined | o->server_bridge_proxy_dhcp)
{
if (o->client)
msg (M_USAGE, "--server-bridge and --client cannot be used together");
if (!(o->server_flags & SF_NOPOOL) && o->ifconfig_pool_defined)
msg (M_USAGE, "--server-bridge already defines an ifconfig-pool, so you can't also specify --ifconfig-pool explicitly");
if (o->shared_secret_file)
msg (M_USAGE, "--server-bridge and --secret cannot be used together (you must use SSL/TLS keys)");
if (dev != DEV_TYPE_TAP)
msg (M_USAGE, "--server-bridge directive only makes sense with --dev tap");
if (o->server_bridge_defined)
{
verify_common_subnet ("--server-bridge", o->server_bridge_ip, o->server_bridge_pool_start, o->server_bridge_netmask);
verify_common_subnet ("--server-bridge", o->server_bridge_pool_start, o->server_bridge_pool_end, o->server_bridge_netmask);
verify_common_subnet ("--server-bridge", o->server_bridge_ip, o->server_bridge_pool_end, o->server_bridge_netmask);
}
o->mode = MODE_SERVER;
o->tls_server = true;
if (o->server_bridge_defined)
{
o->ifconfig_pool_defined = true;
o->ifconfig_pool_start = o->server_bridge_pool_start;
o->ifconfig_pool_end = o->server_bridge_pool_end;
ifconfig_pool_verify_range (M_USAGE, o->ifconfig_pool_start, o->ifconfig_pool_end);
o->ifconfig_pool_netmask = o->server_bridge_netmask;
push_option (o, print_opt_route_gateway (o->server_bridge_ip, &o->gc), M_USAGE);
}
else if (o->server_bridge_proxy_dhcp && !(o->server_flags & SF_NO_PUSH_ROUTE_GATEWAY))
{
push_option (o, print_opt_route_gateway_dhcp (&o->gc), M_USAGE);
}
}
else
#endif /* P2MP_SERVER */
/*
* HELPER DIRECTIVE:
*
* client
*
* EXPANDS TO:
*
* pull
* tls-client
*/
if (o->client)
{
if (o->key_method != 2)
msg (M_USAGE, "--client requires --key-method 2");
o->pull = true;
o->tls_client = true;
}
#endif /* P2MP */
gc_free (&gc);
}
/*
*
* HELPER DIRECTIVE:
*
* keepalive 10 60
*
* EXPANDS TO:
*
* if mode server:
* ping 10
* ping-restart 120
* push "ping 10"
* push "ping-restart 60"
* else
* ping 10
* ping-restart 60
*/
void
helper_keepalive (struct options *o)
{
if (o->keepalive_ping || o->keepalive_timeout)
{
/*
* Sanity checks.
*/
if (o->keepalive_ping <= 0 || o->keepalive_timeout <= 0)
msg (M_USAGE, "--keepalive parameters must be > 0");
if (o->keepalive_ping * 2 > o->keepalive_timeout)
msg (M_USAGE, "the second parameter to --keepalive (restart timeout=%d) must be at least twice the value of the first parameter (ping interval=%d). A ratio of 1:5 or 1:6 would be even better. Recommended setting is --keepalive 10 60.",
o->keepalive_timeout,
o->keepalive_ping);
if (o->ping_send_timeout || o->ping_rec_timeout)
msg (M_USAGE, "--keepalive conflicts with --ping, --ping-exit, or --ping-restart. If you use --keepalive, you don't need any of the other --ping directives.");
/*
* Expand.
*/
if (o->mode == MODE_POINT_TO_POINT)
{
o->ping_rec_timeout_action = PING_RESTART;
o->ping_send_timeout = o->keepalive_ping;
o->ping_rec_timeout = o->keepalive_timeout;
}
#if P2MP_SERVER
else if (o->mode == MODE_SERVER)
{
o->ping_rec_timeout_action = PING_RESTART;
o->ping_send_timeout = o->keepalive_ping;
o->ping_rec_timeout = o->keepalive_timeout * 2;
push_option (o, print_str_int ("ping", o->keepalive_ping, &o->gc), M_USAGE);
push_option (o, print_str_int ("ping-restart", o->keepalive_timeout, &o->gc), M_USAGE);
}
#endif
else
{
ASSERT (0);
}
}
}
/*
*
* HELPER DIRECTIVE:
*
* tcp-nodelay
*
* EXPANDS TO:
*
* if mode server:
* socket-flags TCP_NODELAY
* push "socket-flags TCP_NODELAY"
*/
void
helper_tcp_nodelay (struct options *o)
{
#if P2MP_SERVER
if (o->server_flags & SF_TCP_NODELAY_HELPER)
{
if (o->mode == MODE_SERVER)
{
o->sockflags |= SF_TCP_NODELAY;
push_option (o, print_str ("socket-flags TCP_NODELAY", &o->gc), M_USAGE);
}
else
{
ASSERT (0);
}
}
#endif
}