1 /*
2 * Copyright (c) 2020 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
6 * 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
12 * 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 = "6c:D:d:fH:hnP:p:Vvx:";
31
32 static struct option longopts[] = {
33 {"help", no_argument, NULL, 'h'},
34 {"version", no_argument, NULL, 'V'},
35 {NULL, 0, NULL, 0},
36 };
37
38 struct fcgi fcgi[FCGI_MAX];
39
40 struct vhosthead hosts;
41
42 int sock4, sock6;
43
44 struct imsgbuf logibuf, exibuf, servibuf[PROC_MAX];
45
46 const char *config_path, *certs_dir, *hostname, *pidfile, *cgi;
47
48 struct conf conf;
49
50 struct tls_config *tlsconf;
51 struct tls *ctx;
52
53 static void
dummy_handler(int signo)54 dummy_handler(int signo)
55 {
56 return;
57 }
58
59 /* wrapper around dirname(3). dn must be PATH_MAX+1 at least. */
60 static void
pdirname(const char * path,char * dn)61 pdirname(const char *path, char *dn)
62 {
63 char p[PATH_MAX+1];
64 char *t;
65
66 strlcpy(p, path, sizeof(p));
67 t = dirname(p);
68 memmove(dn, t, strlen(t)+1);
69 }
70
71 static void
mkdirs(const char * path,mode_t mode)72 mkdirs(const char *path, mode_t mode)
73 {
74 char dname[PATH_MAX+1];
75
76 pdirname(path, dname);
77 if (!strcmp(dname, "/"))
78 return;
79 mkdirs(dname, mode);
80 if (mkdir(path, mode) != 0 && errno != EEXIST)
81 fatal("can't mkdir %s: %s", path, strerror(errno));
82 }
83
84 /* $XDG_DATA_HOME/gmid */
85 char *
data_dir(void)86 data_dir(void)
87 {
88 const char *home, *xdg;
89 char *t;
90
91 if ((xdg = getenv("XDG_DATA_HOME")) == NULL) {
92 if ((home = getenv("HOME")) == NULL)
93 errx(1, "XDG_DATA_HOME and HOME both empty");
94 if (asprintf(&t, "%s/.local/share/gmid", home) == -1)
95 err(1, "asprintf");
96 } else {
97 if (asprintf(&t, "%s/gmid", xdg) == -1)
98 err(1, "asprintf");
99 }
100
101 mkdirs(t, 0755);
102 return t;
103 }
104
105 void
load_local_cert(const char * hostname,const char * dir)106 load_local_cert(const char *hostname, const char *dir)
107 {
108 char *cert, *key;
109 struct vhost *h;
110
111 if (asprintf(&cert, "%s/%s.cert.pem", dir, hostname) == -1)
112 errx(1, "asprintf");
113 if (asprintf(&key, "%s/%s.key.pem", dir, hostname) == -1)
114 errx(1, "asprintf");
115
116 if (access(cert, R_OK) == -1 || access(key, R_OK) == -1)
117 gen_certificate(hostname, cert, key);
118
119 h = TAILQ_FIRST(&hosts);
120 h->cert = cert;
121 h->key = key;
122 h->domain = hostname;
123 }
124
125 void
load_vhosts(void)126 load_vhosts(void)
127 {
128 struct vhost *h;
129 struct location *l;
130
131 TAILQ_FOREACH(h, &hosts, vhosts) {
132 TAILQ_FOREACH(l, &h->locations, locations) {
133 if (l->dir == NULL)
134 continue;
135 if ((l->dirfd = open(l->dir, O_RDONLY | O_DIRECTORY)) == -1)
136 fatal("open %s for domain %s", l->dir, h->domain);
137 }
138 }
139 }
140
141 int
make_socket(int port,int family)142 make_socket(int port, int family)
143 {
144 int sock, v;
145 struct sockaddr_in addr4;
146 struct sockaddr_in6 addr6;
147 struct sockaddr *addr;
148 socklen_t len;
149
150 switch (family) {
151 case AF_INET:
152 bzero(&addr4, sizeof(addr4));
153 addr4.sin_family = family;
154 addr4.sin_port = htons(port);
155 addr4.sin_addr.s_addr = INADDR_ANY;
156 addr = (struct sockaddr*)&addr4;
157 len = sizeof(addr4);
158 break;
159
160 case AF_INET6:
161 bzero(&addr6, sizeof(addr6));
162 addr6.sin6_family = AF_INET6;
163 addr6.sin6_port = htons(port);
164 addr6.sin6_addr = in6addr_any;
165 addr = (struct sockaddr*)&addr6;
166 len = sizeof(addr6);
167 break;
168
169 default:
170 /* unreachable */
171 abort();
172 }
173
174 if ((sock = socket(family, SOCK_STREAM, 0)) == -1)
175 fatal("socket: %s", strerror(errno));
176
177 v = 1;
178 if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &v, sizeof(v)) == -1)
179 fatal("setsockopt(SO_REUSEADDR): %s", strerror(errno));
180
181 v = 1;
182 if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &v, sizeof(v)) == -1)
183 fatal("setsockopt(SO_REUSEPORT): %s", strerror(errno));
184
185 mark_nonblock(sock);
186
187 if (bind(sock, addr, len) == -1)
188 fatal("bind: %s", strerror(errno));
189
190 if (listen(sock, 16) == -1)
191 fatal("listen: %s", strerror(errno));
192
193 return sock;
194 }
195
196 void
setup_tls(void)197 setup_tls(void)
198 {
199 struct vhost *h;
200
201 if ((tlsconf = tls_config_new()) == NULL)
202 fatal("tls_config_new");
203
204 /* optionally accept client certs, but don't try to verify them */
205 tls_config_verify_client_optional(tlsconf);
206 tls_config_insecure_noverifycert(tlsconf);
207
208 if (tls_config_set_protocols(tlsconf, conf.protos) == -1)
209 fatal("tls_config_set_protocols");
210
211 if ((ctx = tls_server()) == NULL)
212 fatal("tls_server failure");
213
214 h = TAILQ_FIRST(&hosts);
215
216 /* we need to set something, then we can add how many key we want */
217 if (tls_config_set_keypair_file(tlsconf, h->cert, h->key))
218 fatal("tls_config_set_keypair_file failed for (%s, %s)",
219 h->cert, h->key);
220
221 while ((h = TAILQ_NEXT(h, vhosts)) != NULL) {
222 if (tls_config_add_keypair_file(tlsconf, h->cert, h->key) == -1)
223 fatal("failed to load the keypair (%s, %s)",
224 h->cert, h->key);
225 }
226
227 if (tls_configure(ctx, tlsconf) == -1)
228 fatal("tls_configure: %s", tls_error(ctx));
229 }
230
231 static int
listener_main(struct imsgbuf * ibuf)232 listener_main(struct imsgbuf *ibuf)
233 {
234 drop_priv();
235 load_default_mime(&conf.mime);
236 load_vhosts();
237 loop(ctx, sock4, sock6, ibuf);
238 return 0;
239 }
240
241 void
init_config(void)242 init_config(void)
243 {
244 TAILQ_INIT(&hosts);
245
246 conf.port = 1965;
247 conf.ipv6 = 0;
248 conf.protos = TLS_PROTOCOL_TLSv1_2 | TLS_PROTOCOL_TLSv1_3;
249
250 init_mime(&conf.mime);
251
252 conf.chroot = NULL;
253 conf.user = NULL;
254
255 conf.prefork = 3;
256 }
257
258 void
free_config(void)259 free_config(void)
260 {
261 struct vhost *h, *th;
262 struct location *l, *tl;
263 struct envlist *e, *te;
264 struct alist *a, *ta;
265 int v, i;
266
267 v = conf.verbose;
268
269 free(conf.chroot);
270 free(conf.user);
271 memset(&conf, 0, sizeof(conf));
272
273 conf.verbose = v;
274
275 TAILQ_FOREACH_SAFE(h, &hosts, vhosts, th) {
276 TAILQ_FOREACH_SAFE(l, &h->locations, locations, tl) {
277 TAILQ_REMOVE(&h->locations, l, locations);
278
279 free((char*)l->match);
280 free((char*)l->lang);
281 free((char*)l->default_mime);
282 free((char*)l->index);
283 free((char*)l->block_fmt);
284 free((char*)l->dir);
285
286 if (l->dirfd != -1)
287 close(l->dirfd);
288
289 free(l);
290 }
291
292 TAILQ_FOREACH_SAFE(e, &h->env, envs, te) {
293 TAILQ_REMOVE(&h->env, e, envs);
294
295 free(e->name);
296 free(e->value);
297 free(e);
298 }
299
300 TAILQ_FOREACH_SAFE(e, &h->params, envs, te) {
301 TAILQ_REMOVE(&h->params, e, envs);
302
303 free(e->name);
304 free(e->value);
305 free(e);
306 }
307
308 TAILQ_FOREACH_SAFE(a, &h->aliases, aliases, ta) {
309 TAILQ_REMOVE(&h->aliases, a, aliases);
310
311 free(a->alias);
312 free(a);
313 }
314
315 free((char*)h->domain);
316 free((char*)h->cert);
317 free((char*)h->key);
318 free((char*)h->cgi);
319 free((char*)h->entrypoint);
320
321 TAILQ_REMOVE(&hosts, h, vhosts);
322 free(h);
323 }
324
325 for (i = 0; i < FCGI_MAX; ++i) {
326 if (fcgi[i].path == NULL && fcgi[i].prog == NULL)
327 break;
328 free(fcgi[i].path);
329 free(fcgi[i].port);
330 free(fcgi[i].prog);
331
332 fcgi[i].path = NULL;
333 fcgi[i].port = NULL;
334 fcgi[i].prog = NULL;
335
336 fcgi[i].pending = 0;
337 fcgi[i].s = FCGI_OFF;
338 }
339
340 tls_free(ctx);
341 tls_config_free(tlsconf);
342 }
343
344 static int
wait_signal(void)345 wait_signal(void)
346 {
347 sigset_t mask;
348 int signo;
349
350 sigemptyset(&mask);
351 sigaddset(&mask, SIGHUP);
352 sigaddset(&mask, SIGINT);
353 sigaddset(&mask, SIGTERM);
354 sigwait(&mask, &signo);
355
356 return signo == SIGHUP;
357 }
358
359 void
drop_priv(void)360 drop_priv(void)
361 {
362 struct passwd *pw = NULL;
363
364 if (conf.chroot != NULL && conf.user == NULL)
365 fatal("can't chroot without an user to switch to after.");
366
367 if (conf.user != NULL) {
368 if ((pw = getpwnam(conf.user)) == NULL)
369 fatal("can't find user %s", conf.user);
370 }
371
372 if (conf.chroot != NULL) {
373 if (chroot(conf.chroot) != 0 || chdir("/") != 0)
374 fatal("%s: %s", conf.chroot, strerror(errno));
375 }
376
377 if (pw != NULL) {
378 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1)
379 fatal("setresuid(%d): %s", pw->pw_uid,
380 strerror(errno));
381 }
382
383 if (getuid() == 0)
384 log_warn(NULL, "not a good idea to run a network daemon as root");
385 }
386
387 static void
usage(void)388 usage(void)
389 {
390 fprintf(stderr,
391 "Version: " GMID_STRING "\n"
392 "Usage: %s [-fnv] [-c config] [-D macro=value] [-P pidfile]\n"
393 " %s [-6hVv] [-d certs-dir] [-H hostname] [-p port] [-x cgi] [dir]\n",
394 getprogname(),
395 getprogname());
396 }
397
398 static void
logger_init(void)399 logger_init(void)
400 {
401 int p[2];
402
403 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, p) == -1)
404 err(1, "socketpair");
405
406 switch (fork()) {
407 case -1:
408 err(1, "fork");
409 case 0:
410 signal(SIGHUP, SIG_IGN);
411 close(p[0]);
412 setproctitle("logger");
413 imsg_init(&logibuf, p[1]);
414 drop_priv();
415 _exit(logger_main(p[1], &logibuf));
416 default:
417 close(p[1]);
418 imsg_init(&logibuf, p[0]);
419 return;
420 }
421 }
422
423 static int
serve(int argc,char ** argv,struct imsgbuf * ibuf)424 serve(int argc, char **argv, struct imsgbuf *ibuf)
425 {
426 char path[PATH_MAX];
427 int i, p[2];
428 struct vhost *h;
429 struct location *l;
430
431 if (config_path == NULL) {
432 if (hostname == NULL)
433 hostname = "localhost";
434 if (certs_dir == NULL)
435 certs_dir = data_dir();
436 load_local_cert(hostname, certs_dir);
437
438 h = TAILQ_FIRST(&hosts);
439 h->domain = "*";
440
441 l = TAILQ_FIRST(&h->locations);
442 l->auto_index = 1;
443 l->match = "*";
444
445 switch (argc) {
446 case 0:
447 l->dir = getcwd(path, sizeof(path));
448 break;
449 case 1:
450 l->dir = absolutify_path(argv[0]);
451 break;
452 default:
453 usage();
454 return 1;
455 }
456
457 log_notice(NULL, "serving %s on port %d", l->dir, conf.port);
458 }
459
460 /* setup tls before dropping privileges: we don't want user
461 * to put private certs inside the chroot. */
462 setup_tls();
463
464 for (i = 0; i < conf.prefork; ++i) {
465 if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC,
466 PF_UNSPEC, p) == -1)
467 fatal("socketpair: %s", strerror(errno));
468
469 switch (fork()) {
470 case -1:
471 fatal("fork: %s", strerror(errno));
472 case 0: /* child */
473 close(p[0]);
474 imsg_init(&exibuf, p[1]);
475 setproctitle("server");
476 _exit(listener_main(&exibuf));
477 default:
478 close(p[1]);
479 imsg_init(&servibuf[i], p[0]);
480 }
481 }
482
483 setproctitle("executor");
484 drop_priv();
485 _exit(executor_main(ibuf));
486 }
487
488 static int
write_pidfile(const char * pidfile)489 write_pidfile(const char *pidfile)
490 {
491 struct flock lock;
492 int fd;
493
494 if (pidfile == NULL)
495 return -1;
496
497 if ((fd = open(pidfile, O_WRONLY|O_CREAT|O_CLOEXEC, 0600)) == -1)
498 fatal("can't open pidfile %s: %s", pidfile, strerror(errno));
499
500 lock.l_start = 0;
501 lock.l_len = 0;
502 lock.l_type = F_WRLCK;
503 lock.l_whence = SEEK_SET;
504
505 if (fcntl(fd, F_SETLK, &lock) == -1)
506 fatal("can't lock %s, gmid is already running?", pidfile);
507
508 if (ftruncate(fd, 0) == -1)
509 fatal("ftruncate: %s: %s", pidfile, strerror(errno));
510
511 dprintf(fd, "%d\n", getpid());
512
513 return fd;
514 }
515
516 static void
setup_configless(int argc,char ** argv,const char * cgi)517 setup_configless(int argc, char **argv, const char *cgi)
518 {
519 struct vhost *host;
520 struct location *loc;
521
522 host = xcalloc(1, sizeof(*host));
523 host->cgi = cgi;
524 TAILQ_INSERT_HEAD(&hosts, host, vhosts);
525
526 loc = xcalloc(1, sizeof(*loc));
527 loc->fcgi = -1;
528 TAILQ_INSERT_HEAD(&host->locations, loc, locations);
529
530 serve(argc, argv, NULL);
531
532 imsg_compose(&logibuf, IMSG_QUIT, 0, 0, -1, NULL, 0);
533 imsg_flush(&logibuf);
534 }
535
536 static int
parse_portno(const char * p)537 parse_portno(const char *p)
538 {
539 const char *errstr;
540 int n;
541
542 n = strtonum(p, 0, UINT16_MAX, &errstr);
543 if (errstr != NULL)
544 yyerror("port number is %s: %s", errstr, p);
545 return n;
546 }
547
548 int
main(int argc,char ** argv)549 main(int argc, char **argv)
550 {
551 struct imsgbuf exibuf;
552 int ch, conftest = 0, configless = 0;
553 int pidfd, old_ipv6, old_port;
554
555 logger_init();
556 init_config();
557
558 while ((ch = getopt_long(argc, argv, opts, longopts, NULL)) != -1) {
559 switch (ch) {
560 case '6':
561 conf.ipv6 = 1;
562 configless = 1;
563 break;
564
565 case 'c':
566 config_path = absolutify_path(optarg);
567 break;
568
569 case 'D':
570 if (cmdline_symset(optarg) == -1)
571 fatal("could not parse macro definition: %s",
572 optarg);
573 break;
574
575 case 'd':
576 certs_dir = optarg;
577 configless = 1;
578 break;
579
580 case 'f':
581 conf.foreground = 1;
582 break;
583
584 case 'H':
585 hostname = optarg;
586 configless = 1;
587 break;
588
589 case 'h':
590 usage();
591 return 0;
592
593 case 'n':
594 conftest = 1;
595 break;
596
597 case 'P':
598 pidfile = optarg;
599 break;
600
601 case 'p':
602 conf.port = parse_portno(optarg);
603 configless = 1;
604 break;
605
606 case 'V':
607 puts("Version: " GMID_STRING);
608 return 0;
609
610 case 'v':
611 conf.verbose++;
612 break;
613
614 case 'x':
615 /* drop the starting / (if any) */
616 if (*optarg == '/')
617 optarg++;
618 cgi = optarg;
619 configless = 1;
620 break;
621
622 default:
623 usage();
624 return 1;
625 }
626 }
627 argc -= optind;
628 argv += optind;
629
630 if (config_path == NULL) {
631 configless = 1;
632 conf.foreground = 1;
633 conf.prefork = 1;
634 conf.verbose++;
635 }
636
637 if (config_path != NULL && (argc > 0 || configless))
638 fatal("can't specify options in config mode.");
639
640 if (conftest) {
641 if (config_path == NULL)
642 fatal("missing configuration");
643 parse_conf(config_path);
644 puts("config OK");
645 return 0;
646 }
647
648 if (!conf.foreground && !configless) {
649 /* log to syslog */
650 imsg_compose(&logibuf, IMSG_LOG_TYPE, 0, 0, -1, NULL, 0);
651 imsg_flush(&logibuf);
652
653 if (daemon(1, 1) == -1)
654 fatal("daemon: %s", strerror(errno));
655 }
656
657 if (config_path != NULL)
658 parse_conf(config_path);
659
660 sock4 = make_socket(conf.port, AF_INET);
661 sock6 = -1;
662 if (conf.ipv6)
663 sock6 = make_socket(conf.port, AF_INET6);
664
665 signal(SIGPIPE, SIG_IGN);
666 signal(SIGCHLD, SIG_IGN);
667
668 if (configless) {
669 setup_configless(argc, argv, cgi);
670 return 0;
671 }
672
673 pidfd = write_pidfile(pidfile);
674
675 /*
676 * Linux seems to call the event handlers even when we're
677 * doing a sigwait. These dummy handlers are here to avoid
678 * being terminated on SIGHUP, SIGINT or SIGTERM.
679 */
680 signal(SIGHUP, dummy_handler);
681 signal(SIGINT, dummy_handler);
682 signal(SIGTERM, dummy_handler);
683
684 /* wait a sighup and reload the daemon */
685 for (;;) {
686 int p[2];
687
688 if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC,
689 PF_UNSPEC, p) == -1)
690 fatal("socketpair: %s", strerror(errno));
691
692 switch (fork()) {
693 case -1:
694 fatal("fork: %s", strerror(errno));
695 case 0:
696 close(p[0]);
697 imsg_init(&exibuf, p[1]);
698 _exit(serve(argc, argv, &exibuf));
699 }
700
701 close(p[1]);
702 imsg_init(&exibuf, p[0]);
703
704 if (!wait_signal())
705 break;
706
707 log_info(NULL, "reloading configuration %s", config_path);
708
709 /* close the executor (it'll close the servers too) */
710 imsg_compose(&exibuf, IMSG_QUIT, 0, 0, -1, NULL, 0);
711 imsg_flush(&exibuf);
712 close(p[0]);
713
714 old_ipv6 = conf.ipv6;
715 old_port = conf.port;
716
717 free_config();
718 init_config();
719 parse_conf(config_path);
720
721 if (old_port != conf.port) {
722 close(sock4);
723 close(sock6);
724 sock4 = -1;
725 sock6 = -1;
726 }
727
728 if (sock6 != -1 && old_ipv6 != conf.ipv6) {
729 close(sock6);
730 sock6 = -1;
731 }
732
733 if (sock4 == -1)
734 sock4 = make_socket(conf.port, AF_INET);
735 if (sock6 == -1 && conf.ipv6)
736 sock6 = make_socket(conf.port, AF_INET6);
737 }
738
739 imsg_compose(&exibuf, IMSG_QUIT, 0, 0, -1, NULL, 0);
740 imsg_flush(&exibuf);
741
742 imsg_compose(&logibuf, IMSG_QUIT, 0, 0, -1, NULL, 0);
743 imsg_flush(&logibuf);
744
745 if (pidfd != -1)
746 close(pidfd);
747
748 return 0;
749 }
750