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 	for (i = 0; prefix[i] != '\0'; ++i)
160 		if (str[i] != prefix[i])
161 			return 0;
162 	return 1;
163 }
164 
165 int
166 ends_with(const char *str, const char *sufx)
167 {
168 	size_t i, j;
169 
170 	i = strlen(str);
171 	j = strlen(sufx);
172 
173 	if (j > i)
174 		return 0;
175 
176 	i -= j;
177 	for (j = 0; str[i] != '\0'; i++, j++)
178 		if (str[i] != sufx[j])
179 			return 0;
180 	return 1;
181 }
182 
183 ssize_t
184 filesize(int fd)
185 {
186 	ssize_t len;
187 
188 	if ((len = lseek(fd, 0, SEEK_END)) == -1)
189 		return -1;
190 	if (lseek(fd, 0, SEEK_SET) == -1)
191 		return -1;
192 	return len;
193 }
194 
195 char *
196 absolutify_path(const char *path)
197 {
198 	char *wd, *r;
199 
200 	if (*path == '/')
201 		return strdup(path);
202 
203 	wd = getcwd(NULL, 0);
204 	if (asprintf(&r, "%s/%s", wd, path) == -1)
205 		fatal("asprintf: %s", strerror(errno));
206 	free(wd);
207 	return r;
208 }
209 
210 void
211 yyerror(const char *msg)
212 {
213 	goterror = 1;
214 	fprintf(stderr, "%d: %s\n", yylineno, msg);
215 }
216 
217 int
218 parse_portno(const char *p)
219 {
220 	const char *errstr;
221 	int n;
222 
223 	n = strtonum(p, 0, UINT16_MAX, &errstr);
224 	if (errstr != NULL)
225 		errx(1, "port number is %s: %s", errstr, p);
226 	return n;
227 }
228 
229 void
230 parse_conf(const char *path)
231 {
232 	if ((yyin = fopen(path, "r")) == NULL)
233 		fatal("cannot open config %s", path);
234 	yyparse();
235 	fclose(yyin);
236 
237 	if (goterror)
238 		exit(1);
239 }
240 
241 void
242 load_vhosts(struct tls_config *tlsconf)
243 {
244 	struct vhost *h;
245 
246 	/* we need to set something, then we can add how many key we want */
247 	if (tls_config_set_keypair_file(tlsconf, hosts->cert, hosts->key))
248 		fatal("tls_config_set_keypair_file failed");
249 
250 	for (h = hosts; h->domain != NULL; ++h) {
251 		if (tls_config_add_keypair_file(tlsconf, h->cert, h->key) == -1)
252 			fatal("failed to load the keypair (%s, %s)",
253 			    h->cert, h->key);
254 
255 		if ((h->dirfd = open(h->dir, O_RDONLY | O_DIRECTORY)) == -1)
256 			fatal("open %s for domain %s", h->dir, h->domain);
257 	}
258 }
259 
260 int
261 make_socket(int port, int family)
262 {
263 	int sock, v;
264 	struct sockaddr_in addr4;
265 	struct sockaddr_in6 addr6;
266 	struct sockaddr *addr;
267 	socklen_t len;
268 
269         switch (family) {
270 	case AF_INET:
271 		bzero(&addr4, sizeof(addr4));
272 		addr4.sin_family = family;
273 		addr4.sin_port = htons(port);
274 		addr4.sin_addr.s_addr = INADDR_ANY;
275 		addr = (struct sockaddr*)&addr4;
276 		len = sizeof(addr4);
277 		break;
278 
279 	case AF_INET6:
280 		bzero(&addr6, sizeof(addr6));
281 		addr6.sin6_family = AF_INET6;
282 		addr6.sin6_port = htons(port);
283 		addr6.sin6_addr = in6addr_any;
284 		addr = (struct sockaddr*)&addr6;
285 		len = sizeof(addr6);
286 		break;
287 
288 	default:
289 		/* unreachable */
290 		abort();
291 	}
292 
293 	if ((sock = socket(family, SOCK_STREAM, 0)) == -1)
294 		fatal("socket: %s", strerror(errno));
295 
296 	v = 1;
297 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &v, sizeof(v)) == -1)
298 		fatal("setsockopt(SO_REUSEADDR): %s", strerror(errno));
299 
300 	v = 1;
301 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &v, sizeof(v)) == -1)
302 		fatal("setsockopt(SO_REUSEPORT): %s", strerror(errno));
303 
304 	mark_nonblock(sock);
305 
306 	if (bind(sock, addr, len) == -1)
307 		fatal("bind: %s", strerror(errno));
308 
309 	if (listen(sock, 16) == -1)
310 		fatal("listen: %s", strerror(errno));
311 
312 	return sock;
313 }
314 
315 int
316 listener_main()
317 {
318 	int sock4, sock6;
319 	struct tls *ctx = NULL;
320 	struct tls_config *tlsconf;
321 
322 	load_default_mime(&conf.mime);
323 
324 	if ((tlsconf = tls_config_new()) == NULL)
325 		fatal("tls_config_new");
326 
327 	/* optionally accept client certs, but don't try to verify them */
328 	tls_config_verify_client_optional(tlsconf);
329 	tls_config_insecure_noverifycert(tlsconf);
330 
331 	if (tls_config_set_protocols(tlsconf, conf.protos) == -1)
332 		fatal("tls_config_set_protocols");
333 
334 	if ((ctx = tls_server()) == NULL)
335 		fatal("tls_server failure");
336 
337 	load_vhosts(tlsconf);
338 
339 	if (tls_configure(ctx, tlsconf) == -1)
340 		fatal("tls_configure: %s", tls_error(ctx));
341 
342 	if (!conf.foreground && daemon(0, 1) == -1)
343 		exit(1);
344 
345 	sock4 = make_socket(conf.port, AF_INET);
346 	sock6 = -1;
347 	if (conf.ipv6)
348 		sock6 = make_socket(conf.port, AF_INET6);
349 
350 	sandbox();
351 	loop(ctx, sock4, sock6);
352 
353 	return 0;
354 }
355 
356 void
357 usage(const char *me)
358 {
359 	fprintf(stderr,
360 	    "USAGE: %s [-n] [-c config] | [-6fh] [-C cert] [-d root] [-K key] "
361 	    "[-p port] [-x cgi-bin]\n",
362 	    me);
363 }
364 
365 void
366 init_config(void)
367 {
368 	size_t i;
369 
370 	bzero(hosts, sizeof(hosts));
371 	for (i = 0; i < HOSTSLEN; ++i)
372 		hosts[i].dirfd = -1;
373 
374 	conf.foreground = 1;
375 	conf.port = 1965;
376 	conf.ipv6 = 0;
377 	conf.protos = TLS_PROTOCOL_TLSv1_2 | TLS_PROTOCOL_TLSv1_3;
378 
379 	init_mime(&conf.mime);
380 }
381 
382 int
383 main(int argc, char **argv)
384 {
385 	int ch, p[2];
386 	const char *config_path = NULL;
387 	int conftest = 0;
388 
389 	init_config();
390 
391 	while ((ch = getopt(argc, argv, "6C:c:d:fhK:np:x:")) != -1) {
392 		switch (ch) {
393 		case '6':
394 			conf.ipv6 = 1;
395 			break;
396 
397 		case 'C':
398 			hosts[0].cert = optarg;
399 			break;
400 
401 		case 'c':
402 			config_path = optarg;
403 			break;
404 
405 		case 'd':
406 			free((char*)hosts[0].dir);
407 			if ((hosts[0].dir = absolutify_path(optarg)) == NULL)
408 				fatal("absolutify_path");
409 			break;
410 
411 		case 'f':
412 			conf.foreground = 1;
413 			break;
414 
415 		case 'h':
416 			usage(*argv);
417 			return 0;
418 
419 		case 'K':
420 			hosts[0].key = optarg;
421 			break;
422 
423 		case 'n':
424 			conftest = 1;
425 			break;
426 
427 		case 'p':
428 			conf.port = parse_portno(optarg);
429 			break;
430 
431 		case 'x':
432 			/* drop the starting / (if any) */
433 			if (*optarg == '/')
434 				optarg++;
435 			hosts[0].cgi = optarg;
436 			break;
437 
438 		default:
439 			usage(*argv);
440 			return 1;
441 		}
442 	}
443 
444 	if (config_path != NULL) {
445 		if (hosts[0].cert != NULL || hosts[0].key != NULL ||
446 		    hosts[0].dir != NULL)
447 			fatal("can't specify options in conf mode");
448 		parse_conf(config_path);
449 	} else {
450 		if (hosts[0].cert == NULL || hosts[0].key == NULL ||
451 		    hosts[0].dir == NULL)
452 			fatal("missing cert, key or root directory to serve");
453 		hosts[0].domain = "*";
454 	}
455 
456 	if (conftest) {
457 		puts("config OK");
458 		return 0;
459 	}
460 
461 	signal(SIGPIPE, SIG_IGN);
462 	signal(SIGCHLD, SIG_IGN);
463 
464 #ifdef SIGINFO
465 	signal(SIGINFO, sig_handler);
466 #endif
467 	signal(SIGUSR2, sig_handler);
468 
469 	if (!conf.foreground) {
470 		signal(SIGHUP, SIG_IGN);
471 		if (daemon(1, 1) == -1)
472 			fatal("daemon: %s", strerror(errno));
473 	}
474 
475 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, p) == -1)
476 		fatal("socketpair: %s", strerror(errno));
477 
478 	switch (fork()) {
479 	case -1:
480 		fatal("fork: %s", strerror(errno));
481 
482 	case 0:			/* child */
483 		close(p[0]);
484 		exfd = p[1];
485 		listener_main();
486 		_exit(0);
487 
488 	default:		/* parent */
489 		close(p[1]);
490 		return executor_main(p[0]);
491 	}
492 }