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 <errno.h>
18 #include <fcntl.h>
19 #include <limits.h>
20 #include <netdb.h>
21 #include <signal.h>
22 #include <stdarg.h>
23 #include <string.h>
24 
25 #include "gmid.h"
26 
27 struct vhost hosts[HOSTSLEN];
28 
29 int goterror;
30 
31 int exfd;
32 
33 struct conf conf;
34 
35 void
36 fatal(const char *fmt, ...)
37 {
38 	va_list ap;
39 
40 	va_start(ap, fmt);
41 
42 	if (conf.foreground) {
43 		vfprintf(stderr, fmt, ap);
44 		fprintf(stderr, "\n");
45 	} else
46 		vsyslog(LOG_DAEMON | LOG_CRIT, fmt, ap);
47 
48 	va_end(ap);
49 	exit(1);
50 }
51 
52 void
53 logs(int priority, struct client *c,
54     const char *fmt, ...)
55 {
56 	char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV];
57 	char *fmted, *s;
58 	size_t len;
59 	int ec;
60 	va_list ap;
61 
62 	va_start(ap, fmt);
63 
64 	if (c == NULL) {
65 		strncpy(hbuf, "<internal>", sizeof(hbuf));
66 		sbuf[0] = '\0';
67 	} else {
68 		len = sizeof(c->addr);
69 		ec = getnameinfo((struct sockaddr*)&c->addr, len,
70 		    hbuf, sizeof(hbuf),
71 		    sbuf, sizeof(sbuf),
72 		    NI_NUMERICHOST | NI_NUMERICSERV);
73 		if (ec != 0)
74 			fatal("getnameinfo: %s", gai_strerror(ec));
75 	}
76 
77 	if (vasprintf(&fmted, fmt, ap) == -1)
78 		fatal("vasprintf: %s", strerror(errno));
79 
80 	if (conf.foreground)
81 		fprintf(stderr, "%s:%s %s\n", hbuf, sbuf, fmted);
82 	else {
83 		if (asprintf(&s, "%s:%s %s", hbuf, sbuf, fmted) == -1)
84 			fatal("asprintf: %s", strerror(errno));
85 		syslog(priority | LOG_DAEMON, "%s", s);
86 		free(s);
87 	}
88 
89 	free(fmted);
90 
91 	va_end(ap);
92 }
93 
94 /* strchr, but with a bound */
95 static char *
96 gmid_strnchr(char *s, int c, size_t len)
97 {
98 	size_t i;
99 
100 	for (i = 0; i < len; ++i)
101 		if (s[i] == c)
102 			return &s[i];
103 	return NULL;
104 }
105 
106 void
107 log_request(struct client *c, char *meta, size_t l)
108 {
109 	char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV], b[GEMINI_URL_LEN];
110 	char *t;
111 	size_t len;
112 	int ec;
113 
114 	len = sizeof(c->addr);
115 	ec = getnameinfo((struct sockaddr*)&c->addr, len,
116 	    hbuf, sizeof(hbuf),
117 	    sbuf, sizeof(sbuf),
118 	    NI_NUMERICHOST | NI_NUMERICSERV);
119 	if (ec != 0)
120 		fatal("getnameinfo: %s", gai_strerror(ec));
121 
122 	if (c->iri.schema != NULL) {
123 		/* serialize the IRI */
124 		strlcpy(b, c->iri.schema, sizeof(b));
125 		strlcat(b, "://", sizeof(b));
126 		strlcat(b, c->iri.host, sizeof(b));
127 		strlcat(b, "/", sizeof(b));
128 		strlcat(b, c->iri.path, sizeof(b)); /* TODO: sanitize UTF8 */
129 		if (*c->iri.query != '\0') {	    /* TODO: sanitize UTF8 */
130 			strlcat(b, "?", sizeof(b));
131 			strlcat(b, c->iri.query, sizeof(b));
132 		}
133 	} else {
134 		strlcpy(b, c->req, sizeof(b));
135 	}
136 
137 	if ((t = gmid_strnchr(meta, '\r', l)) == NULL)
138 		t = meta + len;
139 
140 	if (conf.foreground)
141 		fprintf(stderr, "%s:%s GET %s %.*s\n", hbuf, sbuf, b,
142 		    (int)(t - meta), meta);
143 	else
144 		syslog(LOG_INFO | LOG_DAEMON, "%s:%s GET %s %.*s",
145 		    hbuf, sbuf, b, (int)(t - meta), meta);
146 }
147 
148 void
149 sig_handler(int sig)
150 {
151 	(void)sig;
152 }
153 
154 int
155 starts_with(const char *str, const char *prefix)
156 {
157 	size_t i;
158 
159 	if (prefix == NULL)
160 		return 0;
161 
162 	for (i = 0; prefix[i] != '\0'; ++i)
163 		if (str[i] != prefix[i])
164 			return 0;
165 	return 1;
166 }
167 
168 int
169 ends_with(const char *str, const char *sufx)
170 {
171 	size_t i, j;
172 
173 	i = strlen(str);
174 	j = strlen(sufx);
175 
176 	if (j > i)
177 		return 0;
178 
179 	i -= j;
180 	for (j = 0; str[i] != '\0'; i++, j++)
181 		if (str[i] != sufx[j])
182 			return 0;
183 	return 1;
184 }
185 
186 ssize_t
187 filesize(int fd)
188 {
189 	ssize_t len;
190 
191 	if ((len = lseek(fd, 0, SEEK_END)) == -1)
192 		return -1;
193 	if (lseek(fd, 0, SEEK_SET) == -1)
194 		return -1;
195 	return len;
196 }
197 
198 char *
199 absolutify_path(const char *path)
200 {
201 	char *wd, *r;
202 
203 	if (*path == '/')
204 		return strdup(path);
205 
206 	wd = getcwd(NULL, 0);
207 	if (asprintf(&r, "%s/%s", wd, path) == -1)
208 		fatal("asprintf: %s", strerror(errno));
209 	free(wd);
210 	return r;
211 }
212 
213 void
214 yyerror(const char *msg)
215 {
216 	goterror = 1;
217 	fprintf(stderr, "%d: %s\n", yylineno, msg);
218 }
219 
220 int
221 parse_portno(const char *p)
222 {
223 	const char *errstr;
224 	int n;
225 
226 	n = strtonum(p, 0, UINT16_MAX, &errstr);
227 	if (errstr != NULL)
228 		errx(1, "port number is %s: %s", errstr, p);
229 	return n;
230 }
231 
232 void
233 parse_conf(const char *path)
234 {
235 	if ((yyin = fopen(path, "r")) == NULL)
236 		fatal("cannot open config %s", path);
237 	yyparse();
238 	fclose(yyin);
239 
240 	if (goterror)
241 		exit(1);
242 }
243 
244 void
245 load_vhosts(struct tls_config *tlsconf)
246 {
247 	struct vhost *h;
248 
249 	/* we need to set something, then we can add how many key we want */
250 	if (tls_config_set_keypair_file(tlsconf, hosts->cert, hosts->key))
251 		fatal("tls_config_set_keypair_file failed");
252 
253 	for (h = hosts; h->domain != NULL; ++h) {
254 		if (tls_config_add_keypair_file(tlsconf, h->cert, h->key) == -1)
255 			fatal("failed to load the keypair (%s, %s)",
256 			    h->cert, h->key);
257 
258 		if ((h->dirfd = open(h->dir, O_RDONLY | O_DIRECTORY)) == -1)
259 			fatal("open %s for domain %s", h->dir, h->domain);
260 	}
261 }
262 
263 int
264 make_socket(int port, int family)
265 {
266 	int sock, v;
267 	struct sockaddr_in addr4;
268 	struct sockaddr_in6 addr6;
269 	struct sockaddr *addr;
270 	socklen_t len;
271 
272         switch (family) {
273 	case AF_INET:
274 		bzero(&addr4, sizeof(addr4));
275 		addr4.sin_family = family;
276 		addr4.sin_port = htons(port);
277 		addr4.sin_addr.s_addr = INADDR_ANY;
278 		addr = (struct sockaddr*)&addr4;
279 		len = sizeof(addr4);
280 		break;
281 
282 	case AF_INET6:
283 		bzero(&addr6, sizeof(addr6));
284 		addr6.sin6_family = AF_INET6;
285 		addr6.sin6_port = htons(port);
286 		addr6.sin6_addr = in6addr_any;
287 		addr = (struct sockaddr*)&addr6;
288 		len = sizeof(addr6);
289 		break;
290 
291 	default:
292 		/* unreachable */
293 		abort();
294 	}
295 
296 	if ((sock = socket(family, SOCK_STREAM, 0)) == -1)
297 		fatal("socket: %s", strerror(errno));
298 
299 	v = 1;
300 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &v, sizeof(v)) == -1)
301 		fatal("setsockopt(SO_REUSEADDR): %s", strerror(errno));
302 
303 	v = 1;
304 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &v, sizeof(v)) == -1)
305 		fatal("setsockopt(SO_REUSEPORT): %s", strerror(errno));
306 
307 	mark_nonblock(sock);
308 
309 	if (bind(sock, addr, len) == -1)
310 		fatal("bind: %s", strerror(errno));
311 
312 	if (listen(sock, 16) == -1)
313 		fatal("listen: %s", strerror(errno));
314 
315 	return sock;
316 }
317 
318 int
319 listener_main()
320 {
321 	int sock4, sock6;
322 	struct tls *ctx = NULL;
323 	struct tls_config *tlsconf;
324 
325 	load_default_mime(&conf.mime);
326 
327 	if ((tlsconf = tls_config_new()) == NULL)
328 		fatal("tls_config_new");
329 
330 	/* optionally accept client certs, but don't try to verify them */
331 	tls_config_verify_client_optional(tlsconf);
332 	tls_config_insecure_noverifycert(tlsconf);
333 
334 	if (tls_config_set_protocols(tlsconf, conf.protos) == -1)
335 		fatal("tls_config_set_protocols");
336 
337 	if ((ctx = tls_server()) == NULL)
338 		fatal("tls_server failure");
339 
340 	load_vhosts(tlsconf);
341 
342 	if (tls_configure(ctx, tlsconf) == -1)
343 		fatal("tls_configure: %s", tls_error(ctx));
344 
345 	if (!conf.foreground && daemon(0, 1) == -1)
346 		exit(1);
347 
348 	sock4 = make_socket(conf.port, AF_INET);
349 	sock6 = -1;
350 	if (conf.ipv6)
351 		sock6 = make_socket(conf.port, AF_INET6);
352 
353 	sandbox();
354 	loop(ctx, sock4, sock6);
355 
356 	return 0;
357 }
358 
359 void
360 usage(const char *me)
361 {
362 	fprintf(stderr,
363 	    "USAGE: %s [-n] [-c config] | [-6fh] [-C cert] [-d root] [-K key] "
364 	    "[-p port] [-x cgi-bin]\n",
365 	    me);
366 }
367 
368 void
369 init_config(void)
370 {
371 	size_t i;
372 
373 	bzero(hosts, sizeof(hosts));
374 	for (i = 0; i < HOSTSLEN; ++i)
375 		hosts[i].dirfd = -1;
376 
377 	conf.foreground = 1;
378 	conf.port = 1965;
379 	conf.ipv6 = 0;
380 	conf.protos = TLS_PROTOCOL_TLSv1_2 | TLS_PROTOCOL_TLSv1_3;
381 
382 	init_mime(&conf.mime);
383 }
384 
385 int
386 main(int argc, char **argv)
387 {
388 	int ch, p[2];
389 	const char *config_path = NULL;
390 	int conftest = 0;
391 
392 	init_config();
393 
394 	while ((ch = getopt(argc, argv, "6C:c:d:fhK:np:x:")) != -1) {
395 		switch (ch) {
396 		case '6':
397 			conf.ipv6 = 1;
398 			break;
399 
400 		case 'C':
401 			hosts[0].cert = optarg;
402 			break;
403 
404 		case 'c':
405 			config_path = optarg;
406 			break;
407 
408 		case 'd':
409 			free((char*)hosts[0].dir);
410 			if ((hosts[0].dir = absolutify_path(optarg)) == NULL)
411 				fatal("absolutify_path");
412 			break;
413 
414 		case 'f':
415 			conf.foreground = 1;
416 			break;
417 
418 		case 'h':
419 			usage(*argv);
420 			return 0;
421 
422 		case 'K':
423 			hosts[0].key = optarg;
424 			break;
425 
426 		case 'n':
427 			conftest = 1;
428 			break;
429 
430 		case 'p':
431 			conf.port = parse_portno(optarg);
432 			break;
433 
434 		case 'x':
435 			/* drop the starting / (if any) */
436 			if (*optarg == '/')
437 				optarg++;
438 			hosts[0].cgi = optarg;
439 			break;
440 
441 		default:
442 			usage(*argv);
443 			return 1;
444 		}
445 	}
446 
447 	if (config_path != NULL) {
448 		if (hosts[0].cert != NULL || hosts[0].key != NULL ||
449 		    hosts[0].dir != NULL)
450 			fatal("can't specify options in conf mode");
451 		parse_conf(config_path);
452 	} else {
453 		if (hosts[0].cert == NULL || hosts[0].key == NULL ||
454 		    hosts[0].dir == NULL)
455 			fatal("missing cert, key or root directory to serve");
456 		hosts[0].domain = "*";
457 	}
458 
459 	if (conftest) {
460 		puts("config OK");
461 		return 0;
462 	}
463 
464 	signal(SIGPIPE, SIG_IGN);
465 	signal(SIGCHLD, SIG_IGN);
466 
467 #ifdef SIGINFO
468 	signal(SIGINFO, sig_handler);
469 #endif
470 	signal(SIGUSR2, sig_handler);
471 
472 	if (!conf.foreground) {
473 		signal(SIGHUP, SIG_IGN);
474 		if (daemon(1, 1) == -1)
475 			fatal("daemon: %s", strerror(errno));
476 	}
477 
478 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, p) == -1)
479 		fatal("socketpair: %s", strerror(errno));
480 
481 	switch (fork()) {
482 	case -1:
483 		fatal("fork: %s", strerror(errno));
484 
485 	case 0:			/* child */
486 		close(p[0]);
487 		exfd = p[1];
488 		listener_main();
489 		_exit(0);
490 
491 	default:		/* parent */
492 		close(p[1]);
493 		return executor_main(p[0]);
494 	}
495 }