summaryrefslogtreecommitdiffstats
path: root/src/fastd.h
blob: fd2a6687a2d3aff69a3c525b12eeea709957d08a (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
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
/*
  Copyright (c) 2012, Matthias Schiffer <mschiffer@universe-factory.net>
  All rights reserved.

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions are met:

    1. Redistributions of source code must retain the above copyright notice,
       this list of conditions and the following disclaimer.
    2. Redistributions in binary form must reproduce the above copyright notice,
       this list of conditions and the following disclaimer in the documentation
       and/or other materials provided with the distribution.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/


#ifndef _FASTD_FASTD_H_
#define _FASTD_FASTD_H_

#include "types.h"
#include "queue.h"

#include <errno.h>
#include <linux/if_ether.h>
#include <netinet/in.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <sys/uio.h>
#include <sys/socket.h>
#include <time.h>
#include <unistd.h>


#define FASTD_VERSION "6+"


/* This must be adjusted when new methods are added */
#define MAX_METHODS 3


struct fastd_buffer {
	void *base;
	size_t base_len;

	void *data;
	size_t len;
};

struct fastd_eth_addr {
	uint8_t data[ETH_ALEN];
};

struct fastd_protocol {
	const char *name;

	fastd_protocol_config_t* (*init)(fastd_context_t *ctx);
	void (*peer_configure)(fastd_context_t *ctx, fastd_peer_config_t *peer_conf);

	void (*handshake_init)(fastd_context_t *ctx, const fastd_socket_t *sock, const fastd_peer_address_t *address, const fastd_peer_config_t *peer_conf);
	void (*handshake_handle)(fastd_context_t *ctx, fastd_socket_t *sock, const fastd_peer_address_t *address, const fastd_peer_config_t *peer_conf, const fastd_handshake_t *handshake, const fastd_method_t *method);

	void (*handle_recv)(fastd_context_t *ctx, fastd_peer_t *peer, fastd_buffer_t buffer);
	void (*send)(fastd_context_t *ctx, fastd_peer_t *peer, fastd_buffer_t buffer);

	void (*init_peer_state)(fastd_context_t *ctx, fastd_peer_t *peer);
	void (*reset_peer_state)(fastd_context_t *ctx, fastd_peer_t *peer);
	void (*free_peer_state)(fastd_context_t *ctx, fastd_peer_t *peer);

	void (*generate_key)(fastd_context_t *ctx);
	void (*show_key)(fastd_context_t *ctx);
};

struct fastd_method {
	const char *name;

	size_t (*max_packet_size)(fastd_context_t *ctx);
	size_t (*min_encrypt_head_space)(fastd_context_t *ctx);
	size_t (*min_decrypt_head_space)(fastd_context_t *ctx);
	size_t (*min_encrypt_tail_space)(fastd_context_t *ctx);
	size_t (*min_decrypt_tail_space)(fastd_context_t *ctx);

	fastd_method_session_state_t* (*session_init)(fastd_context_t *ctx, uint8_t *secret, size_t length, bool initiator);
	bool (*session_is_valid)(fastd_context_t *ctx, fastd_method_session_state_t *session);
	bool (*session_is_initiator)(fastd_context_t *ctx, fastd_method_session_state_t *session);
	bool (*session_want_refresh)(fastd_context_t *ctx, fastd_method_session_state_t *session);
	void (*session_free)(fastd_context_t *ctx, fastd_method_session_state_t *session);

	bool (*encrypt)(fastd_context_t *ctx, fastd_peer_t *peer, fastd_method_session_state_t *session, fastd_buffer_t *out, fastd_buffer_t in);
	bool (*decrypt)(fastd_context_t *ctx, fastd_peer_t *peer, fastd_method_session_state_t *session, fastd_buffer_t *out, fastd_buffer_t in);
};

union fastd_peer_address {
	struct sockaddr sa;
	struct sockaddr_in in;
	struct sockaddr_in6 in6;
};

struct fastd_resolve_return {
	char *hostname;
	fastd_peer_address_t constraints;

	fastd_peer_address_t addr;
};

struct fastd_log_file {
	fastd_log_file_t *next;

	int level;
	char *filename;
};

struct fastd_log_fd {
	fastd_log_fd_t *next;

	fastd_log_file_t *config;
	int fd;
};

struct fastd_bind_address {
	fastd_bind_address_t *next;
	fastd_peer_address_t addr;
	char *bindtodev;
};

struct fastd_socket {
	int fd;
	const fastd_bind_address_t *addr;
	fastd_peer_t *peer;
};

struct fastd_peer_group_config {
	fastd_peer_group_config_t *next;
	fastd_peer_group_config_t *parent;
	fastd_peer_group_config_t *children;

	char *name;
	fastd_string_stack_t *peer_dirs;

	/* contraints */
	unsigned max_connections;
};

struct fastd_peer_group {
	fastd_peer_group_t *next;
	fastd_peer_group_t *parent;
	fastd_peer_group_t *children;

	const fastd_peer_group_config_t *conf;

	unsigned n_connections;
};

struct fastd_config {
	int log_stderr_level;
	int log_syslog_level;
	char *log_syslog_ident;
	fastd_log_file_t *log_files;

	unsigned keepalive_interval;
	unsigned peer_stale_time;
	unsigned eth_addr_stale_time;

	unsigned reorder_count;
	unsigned reorder_time;

	unsigned min_handshake_interval;
	unsigned min_resolve_interval;

	char *ifname;

	unsigned n_bind_addrs;
	fastd_bind_address_t *bind_addrs;

	fastd_bind_address_t *bind_addr_default_v4;
	fastd_bind_address_t *bind_addr_default_v6;

	uint16_t mtu;
	fastd_mode_t mode;

	bool forward;

	const fastd_protocol_t *protocol;
	const fastd_method_t *methods[MAX_METHODS];
	const fastd_method_t *method_default;
	char *secret;
	unsigned key_valid;
	unsigned key_refresh;

#ifdef USE_CRYPTO_AES128CTR
	const fastd_crypto_aes128ctr_t *crypto_aes128ctr;
#endif
#ifdef USE_CRYPTO_GHASH
	const fastd_crypto_ghash_t *crypto_ghash;
#endif

	fastd_peer_group_config_t *peer_group;
	fastd_peer_config_t *peers;

	unsigned n_floating;
	unsigned n_v4;
	unsigned n_v6;
	unsigned n_dynamic;
	unsigned n_dynamic_v4;
	unsigned n_dynamic_v6;

	fastd_protocol_config_t *protocol_config;

	char *on_up;
	char *on_up_dir;

	char *on_down;
	char *on_down_dir;

	char *on_establish;
	char *on_establish_dir;

	char *on_disestablish;
	char *on_disestablish_dir;

	bool daemon;
	char *pid_file;

	bool machine_readable;
	bool generate_key;
	bool show_key;
};

struct fastd_context {
	const fastd_config_t *conf;

	fastd_log_fd_t *log_files;

	char *ifname;

	struct timespec now;

	unsigned n_peers;
	fastd_peer_group_t *peer_group;
	fastd_peer_t *peers;
	fastd_queue_t task_queue;

	int resolverfd;
	int resolvewfd;

	int tunfd;

	unsigned n_socks;
	fastd_socket_t *socks;

	fastd_socket_t *sock_default_v4;
	fastd_socket_t *sock_default_v6;

#ifdef USE_CRYPTO_AES128CTR
	fastd_crypto_aes128ctr_context_t *crypto_aes128ctr;
#endif
#ifdef USE_CRYPTO_GHASH
	fastd_crypto_ghash_context_t *crypto_ghash;
#endif

	size_t eth_addr_size;
	size_t n_eth_addr;
	fastd_peer_eth_addr_t *eth_addr;

	unsigned int randseed;

	fastd_protocol_state_t *protocol_state;
};

struct fastd_string_stack {
	fastd_string_stack_t *next;
	char str[];
};


void fastd_send(fastd_context_t *ctx, const fastd_socket_t *sock, const fastd_peer_address_t *address, fastd_buffer_t buffer);
void fastd_send_handshake(fastd_context_t *ctx, const fastd_socket_t *sock, const fastd_peer_address_t *address, fastd_buffer_t buffer);
void fastd_handle_receive(fastd_context_t *ctx, fastd_peer_t *peer, fastd_buffer_t buffer);

fastd_socket_t* fastd_socket_open(fastd_context_t *ctx, fastd_peer_t *peer, int af);

void fastd_setfd(const fastd_context_t *ctx, int fd, int set, int unset);
void fastd_setfl(const fastd_context_t *ctx, int fd, int set, int unset);

void fastd_resolve_peer(fastd_context_t *ctx, fastd_peer_t *peer);

int fastd_vsnprintf(const fastd_context_t *ctx, char *buffer, size_t size, const char *format, va_list ap);
void fastd_logf(const fastd_context_t *ctx, int level, const char *format, ...);

void fastd_read_peer_dir(fastd_context_t *ctx, fastd_config_t *conf, const char *dir);
bool fastd_read_config(fastd_context_t *ctx, fastd_config_t *conf, const char *filename, bool peer_config, int depth);

bool fastd_config_protocol(fastd_context_t *ctx, fastd_config_t *conf, const char *name);
bool fastd_config_method(fastd_context_t *ctx, fastd_config_t *conf, const char *name);
bool fastd_config_crypto(fastd_context_t *ctx, fastd_config_t *conf, const char *alg, const char *impl);
bool fastd_config_add_log_file(fastd_context_t *ctx, fastd_config_t *conf, const char *name, int level);
void fastd_config_bind_address(fastd_context_t *ctx, fastd_config_t *conf, const fastd_peer_address_t *address, const char *bindtodev, bool default_v4, bool default_v6);
void fastd_config_peer_group_push(fastd_context_t *ctx, fastd_config_t *conf, const char *name);
void fastd_config_peer_group_pop(fastd_context_t *ctx, fastd_config_t *conf);
void fastd_config_release(fastd_context_t *ctx, fastd_config_t *conf);
void fastd_configure(fastd_context_t *ctx, fastd_config_t *conf, int argc, char *const argv[]);
void fastd_reconfigure(fastd_context_t *ctx, fastd_config_t *conf);

void fastd_random_bytes(fastd_context_t *ctx, void *buffer, size_t len, bool secure);

static inline int fastd_rand(fastd_context_t *ctx, int min, int max) {
	unsigned int r = (unsigned int)rand_r(&ctx->randseed);
	return (r%(max-min) + min);
}


#define FASTD_DEFAULT_LOG_LEVEL	LOG_INFO


#define pr_fatal(ctx, args...) fastd_logf(ctx, LOG_CRIT, args)
#define pr_error(ctx, args...) fastd_logf(ctx, LOG_ERR, args)
#define pr_warn(ctx, args...) fastd_logf(ctx, LOG_WARNING, args)
#define pr_info(ctx, args...) fastd_logf(ctx, LOG_NOTICE, args)
#define pr_verbose(ctx, args...) fastd_logf(ctx, LOG_INFO, args)
#define pr_debug(ctx, args...) fastd_logf(ctx, LOG_DEBUG, args)

#define pr_warn_errno(ctx, message) pr_warn(ctx, "%s: %s", message, strerror(errno))
#define pr_error_errno(ctx, message) pr_warn(ctx, "%s: %s", message, strerror(errno))
#define exit_fatal(ctx, args...) do { pr_fatal(ctx, args); abort(); } while(0)
#define exit_bug(ctx, message) exit_fatal(ctx, "BUG: %s", message)
#define exit_error(ctx, args...) do { pr_error(ctx, args); exit(1); } while(0)
#define exit_errno(ctx, message) exit_error(ctx, "%s: %s", message, strerror(errno))


#define container_of(ptr, type, member) ({                      \
        const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
        (type *)( (char *)__mptr - offsetof(type,member) );})


static inline size_t alignto(size_t l, size_t a) {
	return ((l+a-1)/a)*a;
}

static inline fastd_buffer_t fastd_buffer_alloc(size_t len, size_t head_space, size_t tail_space) {
	size_t base_len = head_space+len+tail_space;
	void *ptr;
	if (posix_memalign(&ptr, 16, base_len))
		return (fastd_buffer_t){ .base = NULL, .base_len = 0, .data = NULL, .len = 0 };

	return (fastd_buffer_t){ .base = ptr, .base_len = base_len, .data = ptr+head_space, .len = len };
}

static inline void fastd_buffer_free(fastd_buffer_t buffer) {
	free(buffer.base);
}

static inline void fastd_buffer_pull_head(fastd_buffer_t *buffer, size_t len) {
	buffer->data -= len;
	buffer->len += len;

	if (buffer->data < buffer->base)
		abort();
}

static inline void fastd_buffer_push_head(fastd_buffer_t *buffer, size_t len) {
	if (buffer->len < len)
		abort();

	buffer->data += len;
	buffer->len -= len;
}

static inline size_t fastd_max_packet_size(const fastd_context_t *ctx) {
	switch (ctx->conf->mode) {
	case MODE_TAP:
		return ctx->conf->mtu+ETH_HLEN;
	case MODE_TUN:
		return ctx->conf->mtu;
	default:
		exit_bug(ctx, "invalid mode");
	}
}

static inline fastd_string_stack_t* fastd_string_stack_dup(const char *str) {
	fastd_string_stack_t *ret = malloc(sizeof(fastd_string_stack_t) + strlen(str) + 1);
	ret->next = NULL;
	strcpy(ret->str, str);

	return ret;
}

static inline fastd_string_stack_t* fastd_string_stack_dupn(const char *str, size_t len) {
	size_t str_len = strnlen(str, len);
	fastd_string_stack_t *ret = malloc(sizeof(fastd_string_stack_t) + str_len + 1);
	ret->next = NULL;
	strncpy(ret->str, str, str_len);
	ret->str[str_len] = 0;

	return ret;
}

static inline fastd_string_stack_t* fastd_string_stack_push(fastd_string_stack_t *stack, const char *str) {
	fastd_string_stack_t *ret = malloc(sizeof(fastd_string_stack_t) + strlen(str) + 1);
	ret->next = stack;
	strcpy(ret->str, str);

	return ret;
}

static inline void fastd_string_stack_free(fastd_string_stack_t *str) {
	while(str) {
		fastd_string_stack_t *next = str->next;
		free(str);
		str = next;
	}
}

static inline void fastd_socket_close(fastd_context_t *ctx, fastd_socket_t *sock) {
	if (sock->fd >= 0) {
		if(close(sock->fd))
			pr_error_errno(ctx, "closing socket: close");

		sock->fd = -2;
	}
}

static inline bool timespec_after(const struct timespec *tp1, const struct timespec *tp2) {
	return (tp1->tv_sec > tp2->tv_sec ||
		(tp1->tv_sec == tp2->tv_sec && tp1->tv_nsec > tp2->tv_nsec));
}

/* returns (tp1 - tp2) in milliseconds  */
static inline int timespec_diff(const struct timespec *tp1, const struct timespec *tp2) {
	return ((tp1->tv_sec - tp2->tv_sec))*1000 + (tp1->tv_nsec - tp2->tv_nsec)/1e6;
}

static inline bool strequal(const char *str1, const char *str2) {
	if (str1 && str2)
		return (!strcmp(str1, str2));
	else
		return (str1 == str2);
}

#endif /* _FASTD_FASTD_H_ */