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 ssize_t
166 filesize(int fd)
167 {
168 	ssize_t len;
169 
170 	if ((len = lseek(fd, 0, SEEK_END)) == -1)
171 		return -1;
172 	if (lseek(fd, 0, SEEK_SET) == -1)
173 		return -1;
174 	return len;
175 }
176 
177 char *
178 absolutify_path(const char *path)
179 {
180 	char *wd, *r;
181 
182 	if (*path == '/')
183 		return strdup(path);
184 
185 	wd = getcwd(NULL, 0);
186 	if (asprintf(&r, "%s/%s", wd, path) == -1)
187 		fatal("asprintf: %s", strerror(errno));
188 	free(wd);
189 	return r;
190 }
191 
192 void
193 yyerror(const char *msg)
194 {
195 	goterror = 1;
196 	fprintf(stderr, "%d: %s\n", yylineno, msg);
197 }
198 
199 int
200 parse_portno(const char *p)
201 {
202 	char *ep;
203 	long lval;
204 
205 	errno = 0;
206 	lval = strtol(p, &ep, 10);
207 	if (p[0] == '\0' || *ep != '\0')
208 		fatal("not a number: %s", p);
209 	if (lval < 0 || lval > UINT16_MAX)
210 		fatal("port number out of range for domain %s: %ld", p, lval);
211 	return lval;
212 }
213 
214 void
215 parse_conf(const char *path)
216 {
217 	if ((yyin = fopen(path, "r")) == NULL)
218 		fatal("cannot open config %s", path);
219 	yyparse();
220 	fclose(yyin);
221 
222 	if (goterror)
223 		exit(1);
224 }
225 
226 void
227 load_vhosts(struct tls_config *tlsconf)
228 {
229 	struct vhost *h;
230 
231 	/* we need to set something, then we can add how many key we want */
232 	if (tls_config_set_keypair_file(tlsconf, hosts->cert, hosts->key))
233 		fatal("tls_config_set_keypair_file failed");
234 
235 	for (h = hosts; h->domain != NULL; ++h) {
236 		if (tls_config_add_keypair_file(tlsconf, h->cert, h->key) == -1)
237 			fatal("failed to load the keypair (%s, %s)",
238 			    h->cert, h->key);
239 
240 		if ((h->dirfd = open(h->dir, O_RDONLY | O_DIRECTORY)) == -1)
241 			fatal("open %s for domain %s", h->dir, h->domain);
242 	}
243 }
244 
245 int
246 make_socket(int port, int family)
247 {
248 	int sock, v;
249 	struct sockaddr_in addr4;
250 	struct sockaddr_in6 addr6;
251 	struct sockaddr *addr;
252 	socklen_t len;
253 
254         switch (family) {
255 	case AF_INET:
256 		bzero(&addr4, sizeof(addr4));
257 		addr4.sin_family = family;
258 		addr4.sin_port = htons(port);
259 		addr4.sin_addr.s_addr = INADDR_ANY;
260 		addr = (struct sockaddr*)&addr4;
261 		len = sizeof(addr4);
262 		break;
263 
264 	case AF_INET6:
265 		bzero(&addr6, sizeof(addr6));
266 		addr6.sin6_family = AF_INET6;
267 		addr6.sin6_port = htons(port);
268 		addr6.sin6_addr = in6addr_any;
269 		addr = (struct sockaddr*)&addr6;
270 		len = sizeof(addr6);
271 		break;
272 
273 	default:
274 		/* unreachable */
275 		abort();
276 	}
277 
278 	if ((sock = socket(family, SOCK_STREAM, 0)) == -1)
279 		fatal("socket: %s", strerror(errno));
280 
281 	v = 1;
282 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &v, sizeof(v)) == -1)
283 		fatal("setsockopt(SO_REUSEADDR): %s", strerror(errno));
284 
285 	v = 1;
286 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &v, sizeof(v)) == -1)
287 		fatal("setsockopt(SO_REUSEPORT): %s", strerror(errno));
288 
289 	mark_nonblock(sock);
290 
291 	if (bind(sock, addr, len) == -1)
292 		fatal("bind: %s", strerror(errno));
293 
294 	if (listen(sock, 16) == -1)
295 		fatal("listen: %s", strerror(errno));
296 
297 	return sock;
298 }
299 
300 int
301 listener_main()
302 {
303 	int sock4, sock6;
304 	struct tls *ctx = NULL;
305 	struct tls_config *tlsconf;
306 
307 	load_default_mime(&conf.mime);
308 
309 	if ((tlsconf = tls_config_new()) == NULL)
310 		fatal("tls_config_new");
311 
312 	/* optionally accept client certs, but don't try to verify them */
313 	tls_config_verify_client_optional(tlsconf);
314 	tls_config_insecure_noverifycert(tlsconf);
315 
316 	if (tls_config_set_protocols(tlsconf, conf.protos) == -1)
317 		fatal("tls_config_set_protocols");
318 
319 	if ((ctx = tls_server()) == NULL)
320 		fatal("tls_server failure");
321 
322 	load_vhosts(tlsconf);
323 
324 	if (tls_configure(ctx, tlsconf) == -1)
325 		fatal("tls_configure: %s", tls_error(ctx));
326 
327 	if (!conf.foreground && daemon(0, 1) == -1)
328 		exit(1);
329 
330 	sock4 = make_socket(conf.port, AF_INET);
331 	sock6 = -1;
332 	if (conf.ipv6)
333 		sock6 = make_socket(conf.port, AF_INET6);
334 
335 	sandbox();
336 	loop(ctx, sock4, sock6);
337 
338 	return 0;
339 }
340 
341 void
342 usage(const char *me)
343 {
344 	fprintf(stderr,
345 	    "USAGE: %s [-n] [-c config] | [-6fh] [-C cert] [-d root] [-K key] "
346 	    "[-p port] [-x cgi-bin]\n",
347 	    me);
348 }
349 
350 int
351 main(int argc, char **argv)
352 {
353 	int ch, p[2];
354 	const char *config_path = NULL;
355 	size_t i;
356 	int conftest = 0;
357 
358 	bzero(hosts, sizeof(hosts));
359 	for (i = 0; i < HOSTSLEN; ++i)
360 		hosts[i].dirfd = -1;
361 
362 	conf.foreground = 1;
363 	conf.port = 1965;
364 	conf.ipv6 = 0;
365 	conf.protos = TLS_PROTOCOL_TLSv1_2 | TLS_PROTOCOL_TLSv1_3;
366 
367 	init_mime(&conf.mime);
368 
369 	while ((ch = getopt(argc, argv, "6C:c:d:fhK:np:x:")) != -1) {
370 		switch (ch) {
371 		case '6':
372 			conf.ipv6 = 1;
373 			break;
374 
375 		case 'C':
376 			hosts[0].cert = optarg;
377 			break;
378 
379 		case 'c':
380 			config_path = optarg;
381 			break;
382 
383 		case 'd':
384 			free((char*)hosts[0].dir);
385 			if ((hosts[0].dir = absolutify_path(optarg)) == NULL)
386 				fatal("absolutify_path");
387 			break;
388 
389 		case 'f':
390 			conf.foreground = 1;
391 			break;
392 
393 		case 'h':
394 			usage(*argv);
395 			return 0;
396 
397 		case 'K':
398 			hosts[0].key = optarg;
399 			break;
400 
401 		case 'n':
402 			conftest = 1;
403 			break;
404 
405 		case 'p':
406 			conf.port = parse_portno(optarg);
407 			break;
408 
409 		case 'x':
410 			/* drop the starting / (if any) */
411 			if (*optarg == '/')
412 				optarg++;
413 			hosts[0].cgi = optarg;
414 			break;
415 
416 		default:
417 			usage(*argv);
418 			return 1;
419 		}
420 	}
421 
422 	if (config_path != NULL) {
423 		if (hosts[0].cert != NULL || hosts[0].key != NULL ||
424 		    hosts[0].dir != NULL)
425 			fatal("can't specify options in conf mode");
426 		parse_conf(config_path);
427 	} else {
428 		if (hosts[0].cert == NULL || hosts[0].key == NULL ||
429 		    hosts[0].dir == NULL)
430 			fatal("missing cert, key or root directory to serve");
431 		hosts[0].domain = "*";
432 	}
433 
434 	if (conftest) {
435 		puts("config OK");
436 		return 0;
437 	}
438 
439 	signal(SIGPIPE, SIG_IGN);
440 	signal(SIGCHLD, SIG_IGN);
441 
442 #ifdef SIGINFO
443 	signal(SIGINFO, sig_handler);
444 #endif
445 	signal(SIGUSR2, sig_handler);
446 
447 	if (!conf.foreground) {
448 		signal(SIGHUP, SIG_IGN);
449 		if (daemon(1, 1) == -1)
450 			fatal("daemon: %s", strerror(errno));
451 	}
452 
453 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, p) == -1)
454 		fatal("socketpair: %s", strerror(errno));
455 
456 	switch (fork()) {
457 	case -1:
458 		fatal("fork: %s", strerror(errno));
459 
460 	case 0:			/* child */
461 		close(p[0]);
462 		exfd = p[1];
463 		listener_main();
464 		_exit(0);
465 
466 	default:		/* parent */
467 		close(p[1]);
468 		return executor_main(p[0]);
469 	}
470 }