1
/*
2
 * Copyright (c) 2020, 2021, 2022 Omar Polo <op@omarpolo.com>
3
 *
4
 * Permission to use, copy, modify, and distribute this software for any
5
 * purpose with or without fee is hereby granted, provided that the above
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 * copyright notice and this permission notice appear in all copies.
7
 *
8
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15
 */
16

17
#include "gmid.h"
18

19
#include <sys/stat.h>
20

21
#include <errno.h>
22
#include <fcntl.h>
23
#include <getopt.h>
24
#include <libgen.h>
25
#include <limits.h>
26
#include <pwd.h>
27
#include <signal.h>
28
#include <string.h>
29

30
static const char	*opts = "D:df:hnP:Vv";
31

32
static const struct option longopts[] = {
33
	{"help",	no_argument,		NULL,	'h'},
34
	{"version",	no_argument,		NULL,	'V'},
35
	{NULL,		0,			NULL,	0},
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};
37

38
struct fcgi fcgi[FCGI_MAX];
39

40
struct vhosthead hosts;
41

42
int sock4, sock6;
43

44
struct imsgbuf logibuf, servibuf[PROC_MAX];
45

46
const char *config_path = "/etc/gmid.conf";
47
const char *pidfile;
48

49
struct conf conf;
50

51
struct tls_config *tlsconf;
52
struct tls *ctx;
53

54
static void
55
dummy_handler(int signo)
56
{
57
	return;
58
}
59

60
void
61
load_vhosts(void)
62
{
63
	struct vhost	*h;
64
	struct location	*l;
65

66
	TAILQ_FOREACH(h, &hosts, vhosts) {
67
		TAILQ_FOREACH(l, &h->locations, locations) {
68
			if (*l->dir == '\0')
69
				continue;
70
			if ((l->dirfd = open(l->dir, O_RDONLY | O_DIRECTORY)) == -1)
71
				fatal("open %s for domain %s: %s", l->dir, h->domain,
72
				    strerror(errno));
73
		}
74
	}
75
}
76

77
int
78
make_socket(int port, int family)
79
{
80
	int sock, v;
81
	struct sockaddr_in addr4;
82
	struct sockaddr_in6 addr6;
83
	struct sockaddr *addr;
84
	socklen_t len;
85

86
	switch (family) {
87
	case AF_INET:
88
		memset(&addr4, 0, sizeof(addr4));
89
		addr4.sin_family = family;
90
		addr4.sin_port = htons(port);
91
		addr4.sin_addr.s_addr = INADDR_ANY;
92
		addr = (struct sockaddr*)&addr4;
93
		len = sizeof(addr4);
94
		break;
95

96
	case AF_INET6:
97
		memset(&addr6, 0, sizeof(addr6));
98
		addr6.sin6_family = AF_INET6;
99
		addr6.sin6_port = htons(port);
100
		addr6.sin6_addr = in6addr_any;
101
		addr = (struct sockaddr*)&addr6;
102
		len = sizeof(addr6);
103
		break;
104

105
	default:
106
		/* unreachable */
107
		abort();
108
	}
109

110
	if ((sock = socket(family, SOCK_STREAM, 0)) == -1)
111
		fatal("socket: %s", strerror(errno));
112

113
	v = 1;
114
	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &v, sizeof(v)) == -1)
115
		fatal("setsockopt(SO_REUSEADDR): %s", strerror(errno));
116

117
	v = 1;
118
	if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &v, sizeof(v)) == -1)
119
		fatal("setsockopt(SO_REUSEPORT): %s", strerror(errno));
120

121
	mark_nonblock(sock);
122

123
	if (bind(sock, addr, len) == -1)
124
		fatal("bind: %s", strerror(errno));
125

126
	if (listen(sock, 16) == -1)
127
		fatal("listen: %s", strerror(errno));
128

129
	return sock;
130
}
131

132
static void
133
add_keypair(struct vhost *h)
134
{
135
	if (*h->ocsp == '\0') {
136
		if (tls_config_add_keypair_file(tlsconf, h->cert, h->key) == -1)
137
			fatal("failed to load the keypair (%s, %s)",
138
			    h->cert, h->key);
139
	} else {
140
		if (tls_config_add_keypair_ocsp_file(tlsconf, h->cert, h->key,
141
		    h->ocsp) == -1)
142
			fatal("failed to load the keypair (%s, %s, %s)",
143
			    h->cert, h->key, h->ocsp);
144
	}
145
}
146

147
void
148
setup_tls(void)
149
{
150
	struct vhost *h;
151

152
	if ((tlsconf = tls_config_new()) == NULL)
153
		fatal("tls_config_new");
154

155
	/* optionally accept client certs, but don't try to verify them */
156
	tls_config_verify_client_optional(tlsconf);
157
	tls_config_insecure_noverifycert(tlsconf);
158

159
	if (tls_config_set_protocols(tlsconf, conf.protos) == -1)
160
		fatal("tls_config_set_protocols");
161

162
	if ((ctx = tls_server()) == NULL)
163
		fatal("tls_server failure");
164

165
	h = TAILQ_FIRST(&hosts);
166

167
	/* we need to set something, then we can add how many key we want */
168
	if (tls_config_set_keypair_file(tlsconf, h->cert, h->key))
169
		fatal("tls_config_set_keypair_file failed for (%s, %s)",
170
		    h->cert, h->key);
171

172
	/* same for OCSP */
173
	if (*h->ocsp != '\0' &&
174
	    tls_config_set_ocsp_staple_file(tlsconf, h->ocsp) == -1)
175
		fatal("tls_config_set_ocsp_staple_file failed for (%s)",
176
		    h->ocsp);
177

178
	while ((h = TAILQ_NEXT(h, vhosts)) != NULL)
179
		add_keypair(h);
180

181
	if (tls_configure(ctx, tlsconf) == -1)
182
		fatal("tls_configure: %s", tls_error(ctx));
183
}
184

185
static int
186
listener_main(struct imsgbuf *ibuf)
187
{
188
	drop_priv();
189
	if (load_default_mime(&conf.mime) == -1)
190
		fatal("load_default_mime: %s", strerror(errno));
191
	sort_mime(&conf.mime);
192
	load_vhosts();
193
	loop(ctx, sock4, sock6, ibuf);
194
	return 0;
195
}
196

197
void
198
init_config(void)
199
{
200
	TAILQ_INIT(&hosts);
201

202
	conf.port = 1965;
203
	conf.ipv6 = 0;
204
	conf.protos = TLS_PROTOCOL_TLSv1_2 | TLS_PROTOCOL_TLSv1_3;
205

206
	init_mime(&conf.mime);
207

208
	conf.prefork = 3;
209
}
210

211
void
212
free_config(void)
213
{
214
	struct vhost *h, *th;
215
	struct location *l, *tl;
216
	struct proxy *p, *tp;
217
	struct envlist *e, *te;
218
	struct alist *a, *ta;
219
	int v;
220

221
	v = conf.verbose;
222

223
	free_mime(&conf.mime);
224
	memset(&conf, 0, sizeof(conf));
225

226
	conf.verbose = v;
227

228
	TAILQ_FOREACH_SAFE(h, &hosts, vhosts, th) {
229
		TAILQ_FOREACH_SAFE(l, &h->locations, locations, tl) {
230
			TAILQ_REMOVE(&h->locations, l, locations);
231

232
			if (l->dirfd != -1)
233
				close(l->dirfd);
234

235
			free(l);
236
		}
237

238
		TAILQ_FOREACH_SAFE(e, &h->params, envs, te) {
239
			TAILQ_REMOVE(&h->params, e, envs);
240
			free(e);
241
		}
242

243
		TAILQ_FOREACH_SAFE(a, &h->aliases, aliases, ta) {
244
			TAILQ_REMOVE(&h->aliases, a, aliases);
245
			free(a);
246
		}
247

248
		TAILQ_FOREACH_SAFE(p, &h->proxies, proxies, tp) {
249
			TAILQ_REMOVE(&h->proxies, p, proxies);
250
			tls_unload_file(p->cert, p->certlen);
251
			tls_unload_file(p->key, p->keylen);
252
			free(p);
253
		}
254

255
		TAILQ_REMOVE(&hosts, h, vhosts);
256
		free(h);
257
	}
258

259
	memset(fcgi, 0, sizeof(fcgi));
260

261
	tls_free(ctx);
262
	tls_config_free(tlsconf);
263
}
264

265
static int
266
wait_signal(void)
267
{
268
	sigset_t mask;
269
	int signo;
270

271
	sigemptyset(&mask);
272
	sigaddset(&mask, SIGHUP);
273
	sigaddset(&mask, SIGINT);
274
	sigaddset(&mask, SIGTERM);
275
	sigwait(&mask, &signo);
276

277
	return signo == SIGHUP;
278
}
279

280
void
281
drop_priv(void)
282
{
283
	struct passwd *pw = NULL;
284

285
	if (*conf.chroot != '\0' && *conf.user == '\0')
286
		fatal("can't chroot without an user to switch to after.");
287

288
	if (*conf.user != '\0') {
289
		if ((pw = getpwnam(conf.user)) == NULL)
290
			fatal("can't find user %s", conf.user);
291
	}
292

293
	if (*conf.chroot != '\0') {
294
		if (chroot(conf.chroot) != 0 || chdir("/") != 0)
295
			fatal("%s: %s", conf.chroot, strerror(errno));
296
	}
297

298
	if (pw != NULL) {
299
		if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1)
300
			fatal("setresuid(%d): %s", pw->pw_uid,
301
			    strerror(errno));
302
	}
303

304
	if (getuid() == 0)
305
		log_warn(NULL, "not a good idea to run a network daemon as root");
306
}
307

308
static void
309
usage(void)
310
{
311
	fprintf(stderr,
312
	    "Version: " GMID_STRING "\n"
313
	    "Usage: %s [-dhnVv] [-D macro=value] [-f config] [-P pidfile]\n",
314
	    getprogname());
315
}
316

317
static void
318
logger_init(void)
319
{
320
	int p[2];
321

322
	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, p) == -1)
323
		err(1, "socketpair");
324

325
	switch (fork()) {
326
	case -1:
327
		err(1, "fork");
328
	case 0:
329
		signal(SIGHUP, SIG_IGN);
330
		close(p[0]);
331
		setproctitle("logger");
332
		imsg_init(&logibuf, p[1]);
333
		drop_priv();
334
		_exit(logger_main(p[1], &logibuf));
335
	default:
336
		close(p[1]);
337
		imsg_init(&logibuf, p[0]);
338
		return;
339
	}
340
}
341

342
static void
343
serve(void)
344
{
345
	int i, p[2];
346

347
	/* setup tls before dropping privileges: we don't want user
348
	 * to put private certs inside the chroot. */
349
	setup_tls();
350

351
	for (i = 0; i < conf.prefork; ++i) {
352
		if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC,
353
		    PF_UNSPEC, p) == -1)
354
			fatal("socketpair: %s", strerror(errno));
355

356
		switch (fork()) {
357
		case -1:
358
			fatal("fork: %s", strerror(errno));
359
		case 0:		/* child */
360
			close(p[0]);
361
			imsg_init(&servibuf[i], p[1]);
362
			setproctitle("server");
363
			_exit(listener_main(&servibuf[i]));
364
		default:
365
			close(p[1]);
366
			imsg_init(&servibuf[i], p[0]);
367
		}
368
	}
369
}
370

371
static int
372
write_pidfile(const char *pidfile)
373
{
374
	struct flock	lock;
375
	int		fd;
376

377
	if (pidfile == NULL)
378
		return -1;
379

380
	if ((fd = open(pidfile, O_WRONLY|O_CREAT|O_CLOEXEC, 0600)) == -1)
381
		fatal("can't open pidfile %s: %s", pidfile, strerror(errno));
382

383
	lock.l_start = 0;
384
	lock.l_len = 0;
385
	lock.l_type = F_WRLCK;
386
	lock.l_whence = SEEK_SET;
387

388
	if (fcntl(fd, F_SETLK, &lock) == -1)
389
		fatal("can't lock %s, gmid is already running?", pidfile);
390

391
	if (ftruncate(fd, 0) == -1)
392
		fatal("ftruncate: %s: %s", pidfile, strerror(errno));
393

394
	dprintf(fd, "%d\n", getpid());
395

396
	return fd;
397
}
398

399
int
400
main(int argc, char **argv)
401
{
402
	int i, ch, conftest = 0;
403
	int pidfd, old_ipv6, old_port;
404

405
	logger_init();
406
	init_config();
407

408
	while ((ch = getopt_long(argc, argv, opts, longopts, NULL)) != -1) {
409
		switch (ch) {
410
		case 'D':
411
			if (cmdline_symset(optarg) == -1)
412
				fatal("could not parse macro definition: %s",
413
				    optarg);
414
			break;
415
		case 'd':
416
			conf.foreground = 1;
417
			break;
418
		case 'f':
419
			config_path = absolutify_path(optarg);
420
			break;
421
		case 'h':
422
			usage();
423
			return 0;
424
		case 'n':
425
			conftest++;
426
			break;
427
		case 'P':
428
			pidfile = optarg;
429
			break;
430
		case 'V':
431
			puts("Version: " GMID_STRING);
432
			return 0;
433
		case 'v':
434
			conf.verbose++;
435
			break;
436
		default:
437
			usage();
438
			return 1;
439
		}
440
	}
441
	argc -= optind;
442
	argv += optind;
443

444
	if (argc != 0)
445
		usage();
446

447
	parse_conf(config_path);
448

449
	if (conftest) {
450
		fprintf(stderr, "config OK\n");
451
		if (conftest > 1)
452
			print_conf();
453
		return 0;
454
	}
455

456
	if (!conf.foreground) {
457
		/* log to syslog */
458
		imsg_compose(&logibuf, IMSG_LOG_TYPE, 0, 0, -1, NULL, 0);
459
		imsg_flush(&logibuf);
460

461
		if (daemon(1, 1) == -1)
462
			fatal("daemon: %s", strerror(errno));
463
	}
464

465
	sock4 = make_socket(conf.port, AF_INET);
466
	sock6 = -1;
467
	if (conf.ipv6)
468
		sock6 = make_socket(conf.port, AF_INET6);
469

470
	signal(SIGPIPE, SIG_IGN);
471

472
	pidfd = write_pidfile(pidfile);
473

474
	/*
475
	 * Linux seems to call the event handlers even when we're
476
	 * doing a sigwait.  These dummy handlers are here to avoid
477
	 * being terminated on SIGHUP, SIGINT or SIGTERM.
478
	 */
479
	signal(SIGHUP, dummy_handler);
480
	signal(SIGINT, dummy_handler);
481
	signal(SIGTERM, dummy_handler);
482

483
	/* wait a sighup and reload the daemon */
484
	for (;;) {
485
		serve();
486

487
		if (!wait_signal())
488
			break;
489

490
		log_info(NULL, "reloading configuration %s", config_path);
491

492
		/* close the servers */
493
		for (i = 0; i < conf.prefork; ++i) {
494
			imsg_compose(&servibuf[i], IMSG_QUIT, 0, 0, -1, NULL, 0);
495
			imsg_flush(&servibuf[i]);
496
			close(servibuf[i].fd);
497
		}
498

499
		old_ipv6 = conf.ipv6;
500
		old_port = conf.port;
501

502
		free_config();
503
		init_config();
504
		parse_conf(config_path);
505

506
		if (old_port != conf.port) {
507
			close(sock4);
508
			close(sock6);
509
			sock4 = -1;
510
			sock6 = -1;
511
		}
512

513
		if (sock6 != -1 && old_ipv6 != conf.ipv6) {
514
			close(sock6);
515
			sock6 = -1;
516
		}
517

518
		if (sock4 == -1)
519
			sock4 = make_socket(conf.port, AF_INET);
520
		if (sock6 == -1 && conf.ipv6)
521
			sock6 = make_socket(conf.port, AF_INET6);
522
	}
523

524
	for (i = 0; i < conf.prefork; ++i) {
525
		imsg_compose(&servibuf[i], IMSG_QUIT, 0, 0, -1, NULL, 0);
526
		imsg_flush(&servibuf[i]);
527
		close(servibuf[i].fd);
528
	}
529

530
	imsg_compose(&logibuf, IMSG_QUIT, 0, 0, -1, NULL, 0);
531
	imsg_flush(&logibuf);
532
	close(logibuf.fd);
533

534
	if (pidfd != -1)
535
		close(pidfd);
536

537
	return 0;
538
}