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Date:: Wed Jan 27 23:14:16 2021 UTC
Message:: -v for verbose logging
Actions:: History | Blame | Raw File
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 <sys/stat.h>
18 
19 #include <errno.h>
20 #include <fcntl.h>
21 #include <limits.h>
22 #include <netdb.h>
23 #include <pwd.h>
24 #include <signal.h>
25 #include <stdarg.h>
26 #include <string.h>
27 
28 #include <openssl/pem.h>
29 #include <openssl/x509.h>
30 
31 #include "gmid.h"
32 
33 struct vhost hosts[HOSTSLEN];
34 
35 int exfd, foreground, verbose;
36 
37 struct conf conf;
38 
39 struct tls *ctx;
40 
41 void
42 fatal(const char *fmt, ...)
43 {
44 	va_list ap;
45 
46 	va_start(ap, fmt);
47 
48 	if (foreground) {
49 		vfprintf(stderr, fmt, ap);
50 		fprintf(stderr, "\n");
51 	} else
52 		vsyslog(LOG_DAEMON | LOG_CRIT, fmt, ap);
53 
54 	va_end(ap);
55 	exit(1);
56 }
57 
58 void
59 logs(int priority, struct client *c,
60     const char *fmt, ...)
61 {
62 	char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV];
63 	char *fmted, *s;
64 	size_t len;
65 	int ec;
66 	va_list ap;
67 
68 	if (foreground && !verbose) {
69 		if (priority == LOG_DEBUG || priority == LOG_INFO)
70 			return;
71 	}
72 
73 	va_start(ap, fmt);
74 
75 	if (c == NULL) {
76 		strncpy(hbuf, "<internal>", sizeof(hbuf));
77 		sbuf[0] = '\0';
78 	} else {
79 		len = sizeof(c->addr);
80 		ec = getnameinfo((struct sockaddr*)&c->addr, len,
81 		    hbuf, sizeof(hbuf),
82 		    sbuf, sizeof(sbuf),
83 		    NI_NUMERICHOST | NI_NUMERICSERV);
84 		if (ec != 0)
85 			fatal("getnameinfo: %s", gai_strerror(ec));
86 	}
87 
88 	if (vasprintf(&fmted, fmt, ap) == -1)
89 		fatal("vasprintf: %s", strerror(errno));
90 
91 	if (foreground)
92 		fprintf(stderr, "%s:%s %s\n", hbuf, sbuf, fmted);
93 	else {
94 		if (asprintf(&s, "%s:%s %s", hbuf, sbuf, fmted) == -1)
95 			fatal("asprintf: %s", strerror(errno));
96 		syslog(priority | LOG_DAEMON, "%s", s);
97 		free(s);
98 	}
99 
100 	free(fmted);
101 
102 	va_end(ap);
103 }
104 
105 /* strchr, but with a bound */
106 static char *
107 gmid_strnchr(char *s, int c, size_t len)
108 {
109 	size_t i;
110 
111 	for (i = 0; i < len; ++i)
112 		if (s[i] == c)
113 			return &s[i];
114 	return NULL;
115 }
116 
117 void
118 log_request(struct client *c, char *meta, size_t l)
119 {
120 	char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV], b[GEMINI_URL_LEN];
121 	char *t;
122 	size_t len;
123 	int ec;
124 
125 	len = sizeof(c->addr);
126 	ec = getnameinfo((struct sockaddr*)&c->addr, len,
127 	    hbuf, sizeof(hbuf),
128 	    sbuf, sizeof(sbuf),
129 	    NI_NUMERICHOST | NI_NUMERICSERV);
130 	if (ec != 0)
131 		fatal("getnameinfo: %s", gai_strerror(ec));
132 
133 	if (c->iri.schema != NULL) {
134 		/* serialize the IRI */
135 		strlcpy(b, c->iri.schema, sizeof(b));
136 		strlcat(b, "://", sizeof(b));
137 
138 		/* log the decoded host name, but if it was invalid
139 		 * use the raw one. */
140 		if (*c->domain != '\0')
141 			strlcat(b, c->domain, sizeof(b));
142 		else
143 			strlcat(b, c->iri.host, sizeof(b));
144 
145 		strlcat(b, "/", sizeof(b));
146 		strlcat(b, c->iri.path, sizeof(b)); /* TODO: sanitize UTF8 */
147 		if (*c->iri.query != '\0') {	    /* TODO: sanitize UTF8 */
148 			strlcat(b, "?", sizeof(b));
149 			strlcat(b, c->iri.query, sizeof(b));
150 		}
151 	} else {
152 		strlcpy(b, c->req, sizeof(b));
153 	}
154 
155 	if ((t = gmid_strnchr(meta, '\r', l)) == NULL)
156 		t = meta + len;
157 
158 	if (foreground)
159 		fprintf(stderr, "%s:%s GET %s %.*s\n", hbuf, sbuf, b,
160 		    (int)(t - meta), meta);
161 	else
162 		syslog(LOG_INFO | LOG_DAEMON, "%s:%s GET %s %.*s",
163 		    hbuf, sbuf, b, (int)(t - meta), meta);
164 }
165 
166 void
167 sig_handler(int sig)
168 {
169 	(void)sig;
170 }
171 
172 char *
173 absolutify_path(const char *path)
174 {
175 	char *wd, *r;
176 
177 	if (*path == '/')
178 		return strdup(path);
179 
180 	wd = getcwd(NULL, 0);
181 	if (asprintf(&r, "%s/%s", wd, path) == -1)
182 		fatal("asprintf: %s", strerror(errno));
183 	free(wd);
184 	return r;
185 }
186 
187 void
188 gen_certificate(const char *host, const char *certpath, const char *keypath)
189 {
190 	BIGNUM		e;
191 	EVP_PKEY	*pkey;
192 	RSA		*rsa;
193 	X509		*x509;
194 	X509_NAME	*name;
195 	FILE		*f;
196 	const char	*org = "gmid";
197 
198 	LOGN(NULL, "generating new certificate for %s (it could take a while)",
199 	    host);
200 
201 	if ((pkey = EVP_PKEY_new()) == NULL)
202                 fatal("couldn't create a new private key");
203 
204 	if ((rsa = RSA_new()) == NULL)
205 		fatal("could'nt generate rsa");
206 
207 	BN_init(&e);
208 	BN_set_word(&e, 17);
209 	if (!RSA_generate_key_ex(rsa, 4096, &e, NULL))
210 		fatal("couldn't generate a rsa key");
211 
212 	if (!EVP_PKEY_assign_RSA(pkey, rsa))
213 		fatal("couldn't assign the key");
214 
215 	if ((x509 = X509_new()) == NULL)
216 		fatal("couldn't generate the X509 certificate");
217 
218 	ASN1_INTEGER_set(X509_get_serialNumber(x509), 1);
219 	X509_gmtime_adj(X509_get_notBefore(x509), 0);
220 	X509_gmtime_adj(X509_get_notAfter(x509), 315360000L); /* 10 years */
221 
222 	if (!X509_set_pubkey(x509, pkey))
223 		fatal("couldn't set the public key");
224 
225 	name = X509_get_subject_name(x509);
226 	if (!X509_NAME_add_entry_by_txt(name, "O", MBSTRING_ASC, org, -1, -1, 0))
227 		fatal("couldn't add N to cert");
228 	if (!X509_NAME_add_entry_by_txt(name, "CN", MBSTRING_ASC, host, -1, -1, 0))
229 		fatal("couldn't add CN to cert");
230 	X509_set_issuer_name(x509, name);
231 
232 	if (!X509_sign(x509, pkey, EVP_sha256()))
233                 fatal("couldn't sign the certificate");
234 
235 	if ((f = fopen(keypath, "w")) == NULL)
236 		fatal("fopen(%s): %s", keypath, strerror(errno));
237 	if (!PEM_write_PrivateKey(f, pkey, NULL, NULL, 0, NULL, NULL))
238 		fatal("couldn't write private key");
239 	fclose(f);
240 
241 	if ((f = fopen(certpath, "w")) == NULL)
242 		fatal("fopen(%s): %s", certpath, strerror(errno));
243 	if (!PEM_write_X509(f, x509))
244 		fatal("couldn't write cert");
245 	fclose(f);
246 
247 	X509_free(x509);
248 	RSA_free(rsa);
249 }
250 
251 /* XXX: create recursively */
252 void
253 mkdirs(const char *path)
254 {
255 	if (mkdir(path, 0755) == -1 && errno != EEXIST)
256 		fatal("can't mkdir %s: %s", path, strerror(errno));
257 }
258 
259 /* $XDG_DATA_HOME/gmid */
260 char *
261 data_dir(void)
262 {
263 	const char *home, *xdg;
264 	char *t;
265 
266 	if ((xdg = getenv("XDG_DATA_HOME")) == NULL) {
267 		if ((home = getenv("HOME")) == NULL)
268 			errx(1, "XDG_DATA_HOME and HOME both empty");
269 		if (asprintf(&t, "%s/.local/share/gmid", home) == -1)
270 			err(1, "asprintf");
271 		mkdirs(t);
272 		return t;
273 	}
274 
275 	if (asprintf(&t, "%s/gmid", xdg) == -1)
276 		err(1, "asprintf");
277 	mkdirs(t);
278 	return t;
279 }
280 
281 void
282 load_local_cert(const char *hostname, const char *dir)
283 {
284 	char *cert, *key;
285 
286 	if (asprintf(&cert, "%s/%s.cert.pem", dir, hostname) == -1)
287 		errx(1, "asprintf");
288 	if (asprintf(&key, "%s/%s.key.pem", dir, hostname) == -1)
289 		errx(1, "asprintf");
290 
291 	if (access(cert, R_OK) == -1 || access(key, R_OK) == -1)
292 		gen_certificate(hostname, cert, key);
293 
294 	hosts[0].cert = cert;
295 	hosts[0].key = key;
296 	hosts[0].domain = hostname;
297 }
298 
299 void
300 load_vhosts(void)
301 {
302 	struct vhost *h;
303 
304 	for (h = hosts; h->domain != NULL; ++h) {
305 		if ((h->dirfd = open(h->dir, O_RDONLY | O_DIRECTORY)) == -1)
306 			fatal("open %s for domain %s", h->dir, h->domain);
307 	}
308 }
309 
310 int
311 make_socket(int port, int family)
312 {
313 	int sock, v;
314 	struct sockaddr_in addr4;
315 	struct sockaddr_in6 addr6;
316 	struct sockaddr *addr;
317 	socklen_t len;
318 
319         switch (family) {
320 	case AF_INET:
321 		bzero(&addr4, sizeof(addr4));
322 		addr4.sin_family = family;
323 		addr4.sin_port = htons(port);
324 		addr4.sin_addr.s_addr = INADDR_ANY;
325 		addr = (struct sockaddr*)&addr4;
326 		len = sizeof(addr4);
327 		break;
328 
329 	case AF_INET6:
330 		bzero(&addr6, sizeof(addr6));
331 		addr6.sin6_family = AF_INET6;
332 		addr6.sin6_port = htons(port);
333 		addr6.sin6_addr = in6addr_any;
334 		addr = (struct sockaddr*)&addr6;
335 		len = sizeof(addr6);
336 		break;
337 
338 	default:
339 		/* unreachable */
340 		abort();
341 	}
342 
343 	if ((sock = socket(family, SOCK_STREAM, 0)) == -1)
344 		fatal("socket: %s", strerror(errno));
345 
346 	v = 1;
347 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &v, sizeof(v)) == -1)
348 		fatal("setsockopt(SO_REUSEADDR): %s", strerror(errno));
349 
350 	v = 1;
351 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &v, sizeof(v)) == -1)
352 		fatal("setsockopt(SO_REUSEPORT): %s", strerror(errno));
353 
354 	mark_nonblock(sock);
355 
356 	if (bind(sock, addr, len) == -1)
357 		fatal("bind: %s", strerror(errno));
358 
359 	if (listen(sock, 16) == -1)
360 		fatal("listen: %s", strerror(errno));
361 
362 	return sock;
363 }
364 
365 void
366 setup_tls(void)
367 {
368 	struct tls_config *tlsconf;
369 	struct vhost *h;
370 
371 	if ((tlsconf = tls_config_new()) == NULL)
372 		fatal("tls_config_new");
373 
374 	/* optionally accept client certs, but don't try to verify them */
375 	tls_config_verify_client_optional(tlsconf);
376 	tls_config_insecure_noverifycert(tlsconf);
377 
378 	if (tls_config_set_protocols(tlsconf, conf.protos) == -1)
379 		fatal("tls_config_set_protocols");
380 
381 	if ((ctx = tls_server()) == NULL)
382 		fatal("tls_server failure");
383 
384 	/* we need to set something, then we can add how many key we want */
385 	if (tls_config_set_keypair_file(tlsconf, hosts->cert, hosts->key))
386 		fatal("tls_config_set_keypair_file failed");
387 
388 	for (h = &hosts[1]; h->domain != NULL; ++h) {
389 		if (tls_config_add_keypair_file(tlsconf, h->cert, h->key) == -1)
390 			fatal("failed to load the keypair (%s, %s)",
391 			    h->cert, h->key);
392 	}
393 
394 	if (tls_configure(ctx, tlsconf) == -1)
395 		fatal("tls_configure: %s", tls_error(ctx));
396 }
397 
398 int
399 listener_main(void)
400 {
401 	int sock4, sock6;
402 
403 	load_default_mime(&conf.mime);
404 
405 	sock4 = make_socket(conf.port, AF_INET);
406 	sock6 = -1;
407 	if (conf.ipv6)
408 		sock6 = make_socket(conf.port, AF_INET6);
409 
410 	load_vhosts();
411 
412 	sandbox();
413 	loop(ctx, sock4, sock6);
414 
415 	return 0;
416 }
417 
418 void
419 init_config(void)
420 {
421 	size_t i;
422 
423 	bzero(hosts, sizeof(hosts));
424 	for (i = 0; i < HOSTSLEN; ++i)
425 		hosts[i].dirfd = -1;
426 
427 	conf.port = 1965;
428 	conf.ipv6 = 0;
429 	conf.protos = TLS_PROTOCOL_TLSv1_2 | TLS_PROTOCOL_TLSv1_3;
430 
431 	init_mime(&conf.mime);
432 
433 	conf.chroot = NULL;
434 	conf.user = NULL;
435 }
436 
437 void
438 drop_priv(void)
439 {
440 	struct passwd *pw = NULL;
441 
442 	if (conf.chroot != NULL && conf.user == NULL)
443 		fatal("can't chroot without an user to switch to after.");
444 
445 	if (conf.user != NULL) {
446 		if ((pw = getpwnam(conf.user)) == NULL)
447 			fatal("can't find user %s", conf.user);
448 	}
449 
450 	if (conf.chroot != NULL) {
451 		if (chroot(conf.chroot) != 0 || chdir("/") != 0)
452 			fatal("%s: %s", conf.chroot, strerror(errno));
453 	}
454 
455 	if (pw != NULL) {
456 		if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1)
457 			fatal("setresuid(%d): %s", pw->pw_uid,
458 			    strerror(errno));
459 	}
460 
461 	if (getuid() == 0)
462 		LOGW(NULL, "%s",
463 		    "not a good idea to run a network daemon as root");
464 }
465 
466 void
467 usage(const char *me)
468 {
469 	fprintf(stderr,
470 	    "USAGE: %s [-fn] [-c config] | [-6h] [-d certs-dir] [-H host]"
471 	    "       [-p port] [-x cgi] [dir]",
472 	    me);
473 }
474 
475 int
476 main(int argc, char **argv)
477 {
478 	int ch, p[2];
479 	const char *config_path = NULL, *certs_dir = NULL, *hostname = NULL;
480 	int conftest = 0, configless = 0;
481 
482 	init_config();
483 
484 	while ((ch = getopt(argc, argv, "6c:d:fH:hnp:vx:")) != -1) {
485 		switch (ch) {
486 		case '6':
487 			conf.ipv6 = 1;
488 			configless = 1;
489 			break;
490 
491 		case 'c':
492 			config_path = optarg;
493 			break;
494 
495 		case 'd':
496 			certs_dir = optarg;
497 			configless = 1;
498 			break;
499 
500 		case 'f':
501 			foreground = 1;
502 			break;
503 
504 		case 'H':
505 			hostname = optarg;
506 			configless = 1;
507 			break;
508 
509 		case 'h':
510 			usage(*argv);
511 			return 0;
512 
513 		case 'n':
514 			conftest = 1;
515 			break;
516 
517 		case 'p':
518 			conf.port = parse_portno(optarg);
519 			configless = 1;
520 			break;
521 
522 		case 'v':
523 			verbose = 1;
524 			break;
525 
526 		case 'x':
527 			/* drop the starting / (if any) */
528 			if (*optarg == '/')
529 				optarg++;
530 			hosts[0].cgi = optarg;
531 			configless = 1;
532 			break;
533 
534 		default:
535 			usage(*argv);
536 			return 1;
537 		}
538 	}
539 	argc -= optind;
540 	argv += optind;
541 
542 	if (config_path != NULL) {
543 		if (argc > 0 || configless)
544 			fatal("can't specify options is config mode.");
545 
546 		parse_conf(config_path);
547 	} else {
548 		configless = 1;
549 		foreground = 1;
550 
551 		if (hostname == NULL)
552 			hostname = "localhost";
553 		if (certs_dir == NULL)
554 			certs_dir = data_dir();
555 		load_local_cert(hostname, certs_dir);
556 
557 		hosts[0].domain = "*";
558 		hosts[0].locations[0].auto_index = 1;
559 		hosts[0].locations[0].match = "*";
560 
561                 switch (argc) {
562 		case 0:
563 			hosts[0].dir = ".";
564 			break;
565 		case 1:
566 			hosts[0].dir = argv[0];
567 			break;
568 		default:
569 			usage(getprogname());
570 			return 1;
571 		}
572 
573 		LOGN(NULL, "serving %s on port %d", hosts[0].dir, conf.port);
574 	}
575 
576 	if (conftest) {
577 		puts("config OK");
578 		return 0;
579 	}
580 
581 	/* setup tls before dropping privileges: we don't want user
582 	 * to put private certs inside the chroot. */
583 	setup_tls();
584 	drop_priv();
585 
586 	signal(SIGPIPE, SIG_IGN);
587 	signal(SIGCHLD, SIG_IGN);
588 
589 #ifdef SIGINFO
590 	signal(SIGINFO, sig_handler);
591 #endif
592 	signal(SIGUSR2, sig_handler);
593 	signal(SIGHUP, SIG_IGN);
594 
595 	if (!foreground && !configless) {
596 		if (daemon(1, 1) == -1)
597 			fatal("daemon: %s", strerror(errno));
598 	}
599 
600 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, p) == -1)
601 		fatal("socketpair: %s", strerror(errno));
602 
603 	switch (fork()) {
604 	case -1:
605 		fatal("fork: %s", strerror(errno));
606 
607 	case 0:			/* child */
608 		close(p[0]);
609 		exfd = p[1];
610 		listener_main();
611 		_exit(0);
612 
613 	default:		/* parent */
614 		close(p[1]);
615 		return executor_main(p[0]);
616 	}
617 }