summaryrefslogtreecommitdiffstats
path: root/src/server/server.c
blob: 5bbea913e98b53e9357e7947d2354fc5f5878d5b (plain) (blame)
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
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
/*
 * This file is part of the Distributed Network Block Device 3
 *
 * Copyright(c) 2011-2012 Johann Latocha <johann@latocha.de>
 *
 * This file may be licensed under the terms of of the
 * GNU General Public License Version 2 (the ``GPL'').
 *
 * Software distributed under the License is distributed
 * on an ``AS IS'' basis, WITHOUT WARRANTY OF ANY KIND, either
 * express or implied. See the GPL for the specific language
 * governing rights and limitations.
 *
 * You should have received a copy of the GPL along with this
 * program. If not, go to http://www.gnu.org/licenses/gpl.html
 * or write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <getopt.h>
#include <pthread.h>
#include <string.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <stdint.h>
#include <unistd.h>
#include <assert.h>

#include "../types.h"
#include "../version.h"

#include "locks.h"
#include "sockhelper.h"
#include "server.h"
#include "image.h"
#include "uplink.h"
#include "net.h"
#include "altservers.h"
#include "memlog.h"
#include "globals.h"
#include "integrity.h"
#include "helper.h"

#define MAX_SERVER_SOCKETS 50 // Assume there will be no more than 50 sockets the server will listen on
static int sockets[MAX_SERVER_SOCKETS], socket_count = 0;
#ifdef _DEBUG
int _fake_delay = 0;
#endif

dnbd3_client_t *_clients[SERVER_MAX_CLIENTS];
int _num_clients = 0;
pthread_spinlock_t _clients_lock;

/**
 * Time the server was started
 */
static time_t _startupTime = 0;
static int _doReload = FALSE, _printStats = FALSE;

static int dnbd3_add_client(dnbd3_client_t *client);
static void dnbd3_handle_signal(int signum);
static void dnbd3_printClients();

/**
 * Print help text for usage instructions
 */
void dnbd3_print_help(char *argv_0)
{
	printf( "Usage: %s [OPTIONS]...\n", argv_0 );
	printf( "Start the DNBD3 server\n" );
	printf( "-c or --config      Configuration file (default /etc/dnbd3-server.conf)\n" );
#ifdef _DEBUG
	printf( "-d or --delay       Add a fake network delay of X µs\n" );
#endif
	printf( "-n or --nodaemon    Start server in foreground\n" );
	printf( "-b or --bind        Local Address to bind to\n" );
	//printf( "-r or --reload      Reload configuration file\n" );
	//printf( "-s or --stop        Stop running dnbd3-server\n" );
	//printf( "-i or --info        Print connected clients and used images\n" );
	printf( "-h or --help        Show this help text and quit\n" );
	printf( "-v or --version     Show version and quit\n" );
	printf( "Management functions:\n" );
	printf( "--crc [image-file]  Generate crc block list for given image\n" );
	printf( "--create [image-name] --revision [rid] --size [filesize]\n"
			"\tCreate a local empty image file with a zeroed cache-map for the specified image\n" );
	printf( "\n" );
	exit( 0 );
}

/**
 * Print version information
 */
void dnbd3_print_version()
{
	printf( "Version: %s\n", VERSION_STRING );
	exit( 0 );
}

/**
 * Clean up structs, connections, write out data, then exit
 */
void dnbd3_cleanup()
{
	int i, count;

	_shutdown = TRUE;
	debug_locks_stop_watchdog();
	memlogf( "INFO: Cleanup...\n" );

	for (int i = 0; i < socket_count; ++i) {
		if ( sockets[i] == -1 ) continue;
		close( sockets[i] );
		sockets[i] = -1;
	}
	socket_count = 0;

	altservers_shutdown();

	// Terminate all uplinks
	image_killUplinks();

	// Terminate integrity checker
	integrity_shutdown();

	// Clean up clients
	spin_lock( &_clients_lock );
	for (i = 0; i < _num_clients; ++i) {
		if ( _clients[i] == NULL ) continue;
		dnbd3_client_t * const client = _clients[i];
		spin_lock( &client->lock );
		if ( client->sock >= 0 ) close( client->sock );
		client->sock = -1;
		spin_unlock( &client->lock );
	}
	spin_unlock( &_clients_lock );
	count = -1;
	while ( count != 0 ) {
		count = 0;
		spin_lock( &_clients_lock );
		for (i = 0; i < _num_clients; ++i) {
			if ( _clients[i] == NULL ) continue;
			if ( _clients[i]->running ) {
				count++;
			} else {
				_clients[i] = NULL;
				dnbd3_free_client( _clients[i] );
			}
		}
		spin_unlock( &_clients_lock );
		if ( count != 0 ) {
			printf( "%d clients still active...\n", count );
			sleep( 1 );
		}
	}
	_num_clients = 0;

	// Clean up images
	spin_lock( &_images_lock );
	for (i = 0; i < _num_images; ++i) {
		if ( _images[i] == NULL ) continue;
		_images[i] = image_free( _images[i] );
	}
	_num_images = 0;
	spin_unlock( &_images_lock );

	exit( EXIT_SUCCESS );
}

/**
 * Program entry point
 */
int main(int argc, char *argv[])
{
	int demonize = 1;
	int opt = 0;
	int longIndex = 0;
	char *paramCreate = NULL;
	char *bindAddress = NULL;
	int64_t paramSize = -1;
	int paramRevision = -1;
	static const char *optString = "c:d:b:nrsihv?";
	static const struct option longOpts[] = {
	        { "config", required_argument, NULL, 'c' },
	        { "delay", required_argument, NULL, 'd' },
	        { "nodaemon", no_argument, NULL, 'n' },
	        { "reload", no_argument, NULL, 'r' },
	        { "stop", no_argument, NULL, 's' },
	        { "info", no_argument, NULL, 'i' },
	        { "help", no_argument, NULL, 'h' },
	        { "version", no_argument, NULL, 'v' },
	        { "bind", required_argument, NULL, 'b' },
	        { "crc", required_argument, NULL, 'crc4' },
	        { "assert", no_argument, NULL, 'asrt' },
	        { "create", required_argument, NULL, 'crat' },
	        { "revision", required_argument, NULL, 'rvid' },
	        { "size", required_argument, NULL, 'size' },
	        { 0, 0, 0, 0 }
	};

	opt = getopt_long( argc, argv, optString, longOpts, &longIndex );

	while ( opt != -1 ) {
		switch ( opt ) {
		case 'c':
			_configDir = strdup( optarg );
			break;
		case 'd':
			#ifdef _DEBUG
			_fake_delay = atoi( optarg );
			break;
#else
			printf( "This option is only available in debug builds.\n\n" );
			return EXIT_FAILURE;
#endif
		case 'n':
			demonize = 0;
			break;
		case 'r':
			printf( "INFO: Reloading configuration file...\n\n" );
			//dnbd3_rpc_send(RPC_RELOAD);
			return EXIT_SUCCESS;
		case 's':
			printf( "INFO: Stopping running server...\n\n" );
			//dnbd3_rpc_send(RPC_EXIT);
			return EXIT_SUCCESS;
		case 'i':
			printf( "INFO: Requesting information...\n\n" );
			//dnbd3_rpc_send(RPC_IMG_LIST);
			return EXIT_SUCCESS;
		case 'h':
			case '?':
			dnbd3_print_help( argv[0] );
			break;
		case 'v':
			dnbd3_print_version();
			break;
		case 'b':
			bindAddress = strdup( optarg );
			break;
		case 'crc4':
			return image_generateCrcFile( optarg ) ? 0 : EXIT_FAILURE;
		case 'asrt':
			printf( "Testing a failing assertion:\n" );
			assert( 4 == 5 );
			printf( "Assertion 4 == 5 seems to hold. ;-)\n" );
			return EXIT_SUCCESS;
		case 'crat':
			paramCreate = strdup( optarg );
			break;
		case 'rvid':
			paramRevision = atoi( optarg );
			break;
		case 'size':
			paramSize = strtoll( optarg, NULL, 10 );
			break;
		}
		opt = getopt_long( argc, argv, optString, longOpts, &longIndex );
	}

	// Load general config

	if ( _configDir == NULL ) _configDir = strdup( "/etc/dnbd3-server" );
	globals_loadConfig();
	if ( _basePath == NULL ) {
		printf( "ERROR: basePath not set in %s/%s\n", _configDir, CONFIG_FILENAME );
		exit( EXIT_FAILURE );
	}

	// One-shots first:

	if ( paramCreate != NULL ) {
		return image_create( paramCreate, paramRevision, paramSize ) ? 0 : EXIT_FAILURE;
	}

	// No one-shot detected, normal server operation

	if ( demonize ) daemon( 1, 0 );
	initmemlog();
	spin_init( &_clients_lock, PTHREAD_PROCESS_PRIVATE );
	spin_init( &_images_lock, PTHREAD_PROCESS_PRIVATE );
	altservers_init();
	integrity_init();
	memlogf( "DNBD3 server starting.... Machine type: " ENDIAN_MODE );

	if ( altservers_load() < 0 ) {
		memlogf( "[WARNING] Could not load alt-servers. Does the file exist in %s?", _configDir );
	}

#ifdef _DEBUG
	debug_locks_start_watchdog();
#endif

	// setup signal handler
	signal( SIGTERM, dnbd3_handle_signal );
	signal( SIGINT, dnbd3_handle_signal );
	signal( SIGUSR1, dnbd3_handle_signal );
	signal( SIGUSR2, dnbd3_handle_signal );

	printf( "Loading images....\n" );
	// Load all images in base path
	if ( !image_loadAll( NULL ) ) {
		printf( "[ERROR] Could not load images.\n" );
		return EXIT_FAILURE;
	}

	_startupTime = time( NULL );

	// Give other threads some time to start up before accepting connections
	sleep( 2 );

	// setup network
	sockets[socket_count] = sock_listen_any( PF_INET, PORT, bindAddress );
	if ( sockets[socket_count] != -1 ) ++socket_count;
#ifdef WITH_IPV6
	sockets[socket_count] = sock_listen_any(PF_INET6, PORT, NULL);
	if (sockets[socket_count] != -1) ++socket_count;
#endif
	if ( socket_count == 0 ) exit( EXIT_FAILURE );
	struct sockaddr_storage client;
	socklen_t len;
	int fd;

	// setup rpc
	//pthread_t thread_rpc;
	//pthread_create(&(thread_rpc), NULL, &dnbd3_rpc_mainloop, NULL);

	pthread_attr_t threadAttrs;
	pthread_attr_init( &threadAttrs );
	pthread_attr_setdetachstate( &threadAttrs, PTHREAD_CREATE_DETACHED );

	memlogf( "[INFO] Server is ready..." );

	// +++++++++++++++++++++++++++++++++++++++++++++++++++ main loop
	while ( !_shutdown ) {
		// Handle signals
		if ( _doReload ) {
			_doReload = FALSE;
			memlogf( "INFO: SIGUSR1 received, re-scanning image directory" );
			image_loadAll( NULL );
		}
		if ( _printStats ) {
			_printStats = FALSE;
			printf( "[DEBUG] SIGUSR2 received, stats incoming\n" );
			printf( " ** Images **\n" );
			image_printAll();
			printf( " ** Clients **\n" );
			dnbd3_printClients();
		}
		//
		len = sizeof(client);
		fd = accept_any( sockets, socket_count, &client, &len );
		if ( fd < 0 ) {
			const int err = errno;
			if ( err == EINTR || err == EAGAIN ) continue;
			memlogf( "[ERROR] Client accept failure (err=%d)", err );
			usleep( 10000 ); // 10ms
			continue;
		}
		//memlogf("INFO: Client %s connected\n", inet_ntoa(client.sin_addr));

		sock_set_timeout( fd, SOCKET_TIMEOUT_SERVER_MS );

		dnbd3_client_t *dnbd3_client = dnbd3_init_client( &client, fd );
		if ( dnbd3_client == NULL ) {
			close( fd );
			continue;
		}

		// This has to be done before creating the thread, otherwise a race condition might occur when the new thread dies faster than this thread adds the client to the list after creating the thread
		if ( !dnbd3_add_client( dnbd3_client ) ) {
			dnbd3_client = dnbd3_free_client( dnbd3_client );
			continue;
		}

		if ( 0 != pthread_create( &(dnbd3_client->thread), &threadAttrs, net_client_handler, (void *)(uintptr_t)dnbd3_client ) ) {
			memlogf( "[ERROR] Could not start thread for new client." );
			dnbd3_remove_client( dnbd3_client );
			dnbd3_client = dnbd3_free_client( dnbd3_client );
			continue;
		}
	}
	dnbd3_cleanup();
}

/**
 * Initialize and populate the client struct - called when an incoming
 * connection is accepted
 */
dnbd3_client_t* dnbd3_init_client(struct sockaddr_storage *client, int fd)
{
	dnbd3_client_t *dnbd3_client = calloc( 1, sizeof(dnbd3_client_t) );
	if ( dnbd3_client == NULL ) { // This will never happen thanks to memory overcommit
		memlogf( "[ERROR] Could not alloc dnbd3_client_t for new client." );
		return NULL ;
	}

	if ( client->ss_family == AF_INET ) {
		struct sockaddr_in *v4 = (struct sockaddr_in *)client;
		dnbd3_client->host.type = AF_INET;
		memcpy( dnbd3_client->host.addr, &(v4->sin_addr), 4 );
		dnbd3_client->host.port = v4->sin_port;
	} else if ( client->ss_family == AF_INET6 ) {
		struct sockaddr_in6 *v6 = (struct sockaddr_in6 *)client;
		dnbd3_client->host.type = AF_INET6;
		memcpy( dnbd3_client->host.addr, &(v6->sin6_addr), 16 );
		dnbd3_client->host.port = v6->sin6_port;
	} else {
		memlogf( "[ERROR] New client has unknown address family %d, disconnecting...", (int)client->ss_family );
		free( dnbd3_client );
		return NULL ;
	}
	dnbd3_client->running = TRUE;
	dnbd3_client->sock = fd;
	spin_init( &dnbd3_client->lock, PTHREAD_PROCESS_PRIVATE );
	pthread_mutex_init( &dnbd3_client->sendMutex, NULL );
	return dnbd3_client;
}

/**
 * Remove a client from the clients array
 * Locks on: _clients_lock
 */
void dnbd3_remove_client(dnbd3_client_t *client)
{
	int i;
	spin_lock( &_clients_lock );
	const int cutoff = MAX(10, _num_clients / 2);
	for (i = _num_clients - 1; i >= 0; --i) {
		if ( _clients[i] != client ) continue;
		_clients[i] = NULL;
		if ( i > cutoff && i + 1 == _num_clients ) --_num_clients;
	}
	spin_unlock( &_clients_lock );
}

/**
 * Free the client struct recursively.
 * !! Make sure to call this function after removing the client from _dnbd3_clients !!
 * Locks on: _clients[].lock, _images[].lock
 * might call functions that lock on _images, _image[], uplink.queueLock, client.sendMutex
 */
dnbd3_client_t* dnbd3_free_client(dnbd3_client_t *client)
{
	spin_lock( &client->lock );
	if ( client->sock >= 0 ) close( client->sock );
	client->sock = -1;
	if ( client->image != NULL ) {
		spin_lock( &client->image->lock );
		if ( client->image->uplink != NULL ) uplink_removeClient( client->image->uplink, client );
		spin_unlock( &client->image->lock );
		image_release( client->image );
	}
	client->image = NULL;
	spin_unlock( &client->lock );
	spin_destroy( &client->lock );
	pthread_mutex_lock( &client->sendMutex );
	pthread_mutex_unlock( &client->sendMutex );
	pthread_mutex_destroy( &client->sendMutex );
	free( client );
	return NULL ;
}

//###//

/**
 * Add client to the clients array.
 * Locks on: _clients_lock
 */
static int dnbd3_add_client(dnbd3_client_t *client)
{
	int i;
	spin_lock( &_clients_lock );
	for (i = 0; i < _num_clients; ++i) {
		if ( _clients[i] != NULL ) continue;
		_clients[i] = client;
		spin_unlock( &_clients_lock );
		return TRUE;
	}
	if ( _num_clients >= SERVER_MAX_CLIENTS ) {
		spin_unlock( &_clients_lock );
		memlogf( "[ERROR] Maximum number of clients reached!" );
		return FALSE;
	}
	_clients[_num_clients++] = client;
	spin_unlock( &_clients_lock );
	return TRUE;
}

static void dnbd3_handle_signal(int signum)
{
	if ( signum == SIGINT || signum == SIGTERM ) {
		_shutdown = TRUE;
	} else if ( signum == SIGUSR1 ) {
		_doReload = TRUE;
	} else if ( signum == SIGUSR2 ) {
		_printStats = TRUE;
	}
}

int dnbd3_serverUptime()
{
	return (int)(time( NULL ) - _startupTime);
}

static void dnbd3_printClients()
{
	int i;
	char buffer[100];
	spin_lock( &_clients_lock );
	for (i = 0; i < _num_clients; ++i) {
		if ( _clients[i] == NULL ) continue;
		spin_lock( &_clients[i]->lock );
		host_to_string( &_clients[i]->host, buffer, sizeof(buffer) );
		printf( "Client %s\n", buffer );
		if ( _clients[i]->image != NULL ) printf( "  Image: %s\n", _clients[i]->image->lower_name );
		spin_unlock( &_clients[i]->lock );
	}
	spin_unlock( &_clients_lock );
}