File: vsock.c

package info (click to toggle)
fence-virt 1.0.0-1
  • links: PTS, VCS
  • area: main
  • in suites: bookworm, bullseye
  • size: 772 kB
  • sloc: ansic: 10,257; cpp: 382; makefile: 272; sh: 214; lex: 113; yacc: 105
file content (576 lines) | stat: -rw-r--r-- 12,661 bytes parent folder | download
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
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
/*
  Copyright Red Hat, Inc. 2017

  This program is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License as published by the
  Free Software Foundation; either version 2, or (at your option) any
  later version.

  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.  If not, write to the
  Free Software Foundation, Inc.,  675 Mass Ave, Cambridge, 
  MA 02139, USA.
*/
#include "config.h"

#include <unistd.h>
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <signal.h>
#include <errno.h>
#include <nss.h>
#include <sys/socket.h>
#include <linux/vm_sockets.h>

/* Local includes */
#include "list.h"
#include "simpleconfig.h"
#include "static_map.h"
#include "server_plugin.h"
#include "history.h"
#include "xvm.h"
#include "simple_auth.h"
#include "options.h"
#include "mcast.h"
#include "tcp.h"
#include "tcp_listener.h"
#include "debug.h"
#include "fdops.h"

#define NAME "vsock"
#define VSOCK_VERSION "0.1"

#define VSOCK_MAGIC 0xa32d27c1e

#define VALIDATE(info) \
do {\
	if (!info || info->magic != VSOCK_MAGIC)\
		return -EINVAL;\
} while(0)

typedef struct _vsock_options {
	char *key_file;
	int cid;
	unsigned int port;
	unsigned int hash;
	unsigned int auth;
	unsigned int flags;
} vsock_options;


typedef struct _vsock_info {
	uint64_t magic;
	void *priv;
	map_object_t *map;
	history_info_t *history;
	char key[MAX_KEY_LEN];
	vsock_options args;
	const fence_callbacks_t *cb;
	ssize_t key_len;
	int listen_sock;
} vsock_info;


struct vsock_hostlist_arg {
	map_object_t *map;
	int cid;
	int fd;
};


static int get_peer_cid(int fd, uint32_t *peer_cid) {
	struct sockaddr_vm svm;
	socklen_t len;
	int ret;

	if (!peer_cid)
		return -1;

	len = sizeof(svm);
	ret = getpeername(fd, (struct sockaddr *) &svm, &len);
	if (ret < 0) {
		printf("Error getting peer CID: %s\n", strerror(errno));
		return -1;
	}

	*peer_cid = svm.svm_cid;
	return 0;
}


/*
 * See if we fenced this node recently (successfully)
 * If so, ignore the request for a few seconds.
 *
 * We purge our history when the entries time out.
 */
static int
check_history(void *a, void *b) {
	fence_req_t *old = a, *current = b;

	if (old->request == current->request &&
	    old->seqno == current->seqno &&
	    !strcasecmp((const char *)old->domain,
			(const char *)current->domain)) {
		return 1;
	}
	return 0;
}


static int 
vsock_hostlist(const char *vm_name, const char *vm_uuid,
	       int state, void *priv)
{
	struct vsock_hostlist_arg *arg = (struct vsock_hostlist_arg *) priv;
	host_state_t hinfo;
	struct timeval tv;
	int ret;
	uint32_t peer_cid = 0;
	char peer_cid_str[24];

	ret = get_peer_cid(arg->fd, &peer_cid);
	if (ret < 0) {
		printf("Unable to get peer CID: %s\n", strerror(errno));
		peer_cid_str[0] = '\0';
	} else
		snprintf(peer_cid_str, sizeof(peer_cid_str), "%u", peer_cid);

	/* Noops if auth == AUTH_NONE */

	if (map_check(arg->map, peer_cid_str, vm_uuid) == 0) {
		/* if we don't have access to fence this VM,
		 * we should not see it in a hostlist either */
		return 0;
	}

	strncpy((char *)hinfo.domain, vm_name, sizeof(hinfo.domain) - 1);
	strncpy((char *)hinfo.uuid, vm_uuid, sizeof(hinfo.uuid) - 1);
	hinfo.state = state;

	tv.tv_sec = 1;
	tv.tv_usec = 0;
	ret = _write_retry(arg->fd, &hinfo, sizeof(hinfo), &tv);
	if (ret == sizeof(hinfo))
		return 0;
	return 1;
}


static int
vsock_hostlist_begin(int fd)
{
	struct timeval tv;
	char val = (char) RESP_HOSTLIST;

	tv.tv_sec = 1;
	tv.tv_usec = 0;
	return _write_retry(fd, &val, 1, &tv);
}


static int 
vsock_hostlist_end(int fd)
{
	host_state_t hinfo;
	struct timeval tv;
	int ret;

	printf("Sending terminator packet\n");

	memset(&hinfo, 0, sizeof(hinfo));

	tv.tv_sec = 1;
	tv.tv_usec = 0;
	ret = _write_retry(fd, &hinfo, sizeof(hinfo), &tv);
	if (ret == sizeof(hinfo))
		return 0;
	return 1;
}


static int
do_fence_request_vsock(int fd, fence_req_t *req, vsock_info *info)
{
	char response = 1;
	struct vsock_hostlist_arg arg;
	uint32_t peer_cid = 0;
	char peer_cid_str[24];
	int ret;

	ret = get_peer_cid(fd, &peer_cid);
	if (ret < 0) {
		printf("Unable to get peer CID: %s\n", strerror(errno));
		return -1;
	}

	snprintf(peer_cid_str, sizeof(peer_cid_str), "%u", peer_cid);

	/* Noops if auth == AUTH_NONE */
	if (sock_response(fd, info->args.auth, info->key, info->key_len, 10) <= 0) {
		printf("CID %u Failed to respond to challenge\n", peer_cid);
		close(fd);
		return -1;
	}

	ret = sock_challenge(fd, info->args.auth, info->key, info->key_len, 10);
	if (ret <= 0) {
		printf("Remote CID %u failed challenge\n", peer_cid);
		close(fd);
		return -1;
	}

	dbg_printf(2, "Request %d seqno %d target %s from CID %u\n", 
		   req->request, req->seqno, req->domain, peer_cid);

	switch(req->request) {
	case FENCE_NULL:
		response = info->cb->null((char *)req->domain, info->priv);
		break;
	case FENCE_ON:
		if (map_check(info->map, peer_cid_str,
				     (const char *)req->domain) == 0) {
			response = RESP_PERM;
			break;
		}
		response = info->cb->on((char *)req->domain, peer_cid_str,
					req->seqno, info->priv);
		break;
	case FENCE_OFF:
		if (map_check(info->map, peer_cid_str,
				     (const char *)req->domain) == 0) {
			response = RESP_PERM;
			break;
		}
		response = info->cb->off((char *)req->domain, peer_cid_str,
					 req->seqno, info->priv);
		break;
	case FENCE_REBOOT:
		if (map_check(info->map, peer_cid_str,
				     (const char *)req->domain) == 0) {
			response = RESP_PERM;
			break;
		}
		response = info->cb->reboot((char *)req->domain, peer_cid_str,
					    req->seqno, info->priv);
		break;
	case FENCE_STATUS:
		if (map_check(info->map, peer_cid_str,
				     (const char *)req->domain) == 0) {
			response = RESP_PERM;
			break;
		}
		response = info->cb->status((char *)req->domain, info->priv);
		break;
	case FENCE_DEVSTATUS:
		response = info->cb->devstatus(info->priv);
		break;
	case FENCE_HOSTLIST:
		arg.map = info->map;
		arg.fd = fd;

		vsock_hostlist_begin(arg.fd);
		response = info->cb->hostlist(vsock_hostlist, &arg, info->priv);
		vsock_hostlist_end(arg.fd);
		break;
	}

	dbg_printf(3, "Sending response to caller CID %u...\n", peer_cid);
	if (_write_retry(fd, &response, 1, NULL) < 0)
		perror("write");

	history_record(info->history, req);

	if (fd != -1)
		close(fd);

	return 1;
}


static int
vsock_dispatch(listener_context_t c, struct timeval *timeout)
{
	vsock_info *info;
	fence_req_t data;
	fd_set rfds;
	int n;
	int client_fd;
    int ret;
	struct timeval tv;

    if (timeout != NULL)
    	memcpy(&tv, timeout, sizeof(tv));
    else {
        tv.tv_sec = 1;
        tv.tv_usec = 0;
    }

	info = (vsock_info *) c;
	VALIDATE(info);

	FD_ZERO(&rfds);
	FD_SET(info->listen_sock, &rfds);

	n = select(info->listen_sock + 1, &rfds, NULL, NULL, timeout);
	if (n <= 0) {
		if (errno == EINTR || errno == EAGAIN)
			n = 0;
		else
			dbg_printf(2, "select: %s\n", strerror(errno));
		return n;
	}

	
	client_fd = accept(info->listen_sock, NULL, NULL);
	if (client_fd < 0) {
		perror("accept");
		return -1;
	}

	dbg_printf(3, "Accepted vsock client...\n");

	ret = _read_retry(client_fd, &data, sizeof(data), &tv);
	if (ret != sizeof(data)) {
		dbg_printf(3, "Invalid request (read %d bytes)\n", ret);
		close(client_fd);
		return 0;
	}

	swab_fence_req_t(&data);

	if (!verify_request(&data, info->args.hash, info->key, info->key_len)) {
		printf("Key mismatch; dropping client\n");
        close(client_fd);
		return 0;
	}

	dbg_printf(3, "Request %d seqno %d domain %s\n",
		data.request, data.seqno, data.domain);

	if (history_check(info->history, &data) == 1) {
		printf("We just did this request; dropping client\n");
        close(client_fd);
		return 0;
	}
		
	switch(info->args.auth) {
	case AUTH_NONE:
	case AUTH_SHA1:
	case AUTH_SHA256:
	case AUTH_SHA512:
		printf("VSOCK request\n");
		do_fence_request_vsock(client_fd, &data, info);
		break;
	default:
		printf("XXX Unhandled authentication\n");
	}

	return 0;
}


static int
vsock_config(config_object_t *config, vsock_options *args)
{
	char value[1024];
	int errors = 0;

#ifdef _MODULE
	if (sc_get(config, "fence_virtd/@debug", value, sizeof(value))==0)
		dset(atoi(value));
#endif

	if (sc_get(config, "listeners/vsock/@key_file",
		   value, sizeof(value)-1) == 0) {
		dbg_printf(1, "Got %s for key_file\n", value);
		args->key_file = strdup(value);
	} else {
		args->key_file = strdup(DEFAULT_KEY_FILE);
		if (!args->key_file) {
			dbg_printf(1, "Failed to allocate memory\n");
			return -1;
		}
	}

	args->hash = DEFAULT_HASH;
	if (sc_get(config, "listeners/vsock/@hash",
		   value, sizeof(value)-1) == 0) {
		dbg_printf(1, "Got %s for hash\n", value);
		if (!strcasecmp(value, "none")) {
			args->hash = HASH_NONE;
		} else if (!strcasecmp(value, "sha1")) {
			args->hash = HASH_SHA1;
		} else if (!strcasecmp(value, "sha256")) {
			args->hash = HASH_SHA256;
		} else if (!strcasecmp(value, "sha512")) {
			args->hash = HASH_SHA512;
		} else {
			dbg_printf(1, "Unsupported hash: %s\n", value);
			++errors;
		}
	}
	
	args->auth = DEFAULT_AUTH;
	if (sc_get(config, "listeners/vsock/@auth",
		   value, sizeof(value)-1) == 0) {
		dbg_printf(1, "Got %s for auth\n", value);
		if (!strcasecmp(value, "none")) {
			args->hash = AUTH_NONE;
		} else if (!strcasecmp(value, "sha1")) {
			args->hash = AUTH_SHA1;
		} else if (!strcasecmp(value, "sha256")) {
			args->hash = AUTH_SHA256;
		} else if (!strcasecmp(value, "sha512")) {
			args->hash = AUTH_SHA512;
		} else {
			dbg_printf(1, "Unsupported auth: %s\n", value);
			++errors;
		}
	}
	
	args->port = DEFAULT_MCAST_PORT;
	if (sc_get(config, "listeners/vsock/@port",
		   value, sizeof(value)-1) == 0) {
		dbg_printf(1, "Got %s for port\n", value);
		args->port = atoi(value);
		if (args->port <= 0) {
			dbg_printf(1, "Invalid port: %s\n", value);
			++errors;
		}
	}

	return errors;
}


static int
vsock_init(listener_context_t *c, const fence_callbacks_t *cb,
	   config_object_t *config, map_object_t *map, void *priv)
{
	vsock_info *info;
	int listen_sock, ret;
	struct sockaddr_vm svm;

	if (NSS_NoDB_Init(NULL) != SECSuccess) {
		printf("Could not initialize NSS\n");
		return 1;
	}

	info = calloc(1, sizeof(*info));
	if (!info)
		return -1;

	info->priv = priv;
	info->cb = cb;
	info->map = map;

	ret = vsock_config(config, &info->args);
	if (ret < 0)
		perror("vsock_config");
	else if (ret > 0)
		printf("%d errors found during vsock listener configuration\n", ret);

	if (ret != 0) {
		if (info->args.key_file)
			free(info->args.key_file);
		free(info);
		return -1;
	}

	if (info->args.auth != AUTH_NONE || info->args.hash != HASH_NONE) {
		info->key_len = read_key_file(info->args.key_file,
					info->key, sizeof(info->key));
		if (info->key_len < 0) {
			printf("Could not read %s; operating without "
			       "authentication\n", info->args.key_file);
			info->args.auth = AUTH_NONE;
			info->args.hash = HASH_NONE;
			info->key_len = 0;
		}
	}

	listen_sock = socket(PF_VSOCK, SOCK_STREAM, 0);
	if (listen_sock < 0)
		goto out_fail;

	memset(&svm, 0, sizeof(svm));
	svm.svm_family = AF_VSOCK;
	svm.svm_cid = VMADDR_CID_ANY;
	svm.svm_port = info->args.port;

	if (bind(listen_sock, (struct sockaddr *) &svm, sizeof(svm)) < 0)
		goto out_fail;

	if (listen(listen_sock, 1) < 0)
		goto out_fail;

	info->magic = VSOCK_MAGIC;
	info->listen_sock = listen_sock;
	info->history = history_init(check_history, 10, sizeof(fence_req_t));
	*c = (listener_context_t)info;
	return 0;

out_fail:
	printf("Could not set up listen socket: %s\n", strerror(errno));
	if (listen_sock >= 0)
		close(listen_sock);
	if (info->args.key_file)
		free(info->args.key_file);
	free(info);
	return -1;
}


static int
vsock_shutdown(listener_context_t c)
{
	vsock_info *info = (vsock_info *)c;

	VALIDATE(info);
	info->magic = 0;
	history_wipe(info->history);
	free(info->history);
	free(info->args.key_file);
	close(info->listen_sock);
	free(info);

	return 0;
}


static listener_plugin_t vsock_plugin = {
	.name = NAME,
	.version = VSOCK_VERSION,
	.init = vsock_init,
	.dispatch = vsock_dispatch,
	.cleanup = vsock_shutdown,
};


#ifdef _MODULE
double
LISTENER_VER_SYM(void)
{
	return PLUGIN_VERSION_LISTENER;
}

const listener_plugin_t *
LISTENER_INFO_SYM(void)
{
	return &vsock_plugin;
}
#else
static void __attribute__((constructor))
vsock_register_plugin(void)
{
	plugin_reg_listener(&vsock_plugin);
}
#endif