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 	/* serialize the IRI */
123 	strlcpy(b, c->iri.schema, sizeof(b));
124 	strlcat(b, "://", sizeof(b));
125 	strlcat(b, c->iri.host, sizeof(b));
126 	strlcat(b, "/", sizeof(b));
127 	strlcat(b, c->iri.path, sizeof(b)); /* TODO: sanitize UTF8 */
128 	if (*c->iri.query != '\0') {	    /* TODO: sanitize UTF8 */
129 		strlcat(b, "?", sizeof(b));
130 		strlcat(b, c->iri.query, sizeof(b));
131 	}
132 
133 	if ((t = gmid_strnchr(meta, '\r', l)) == NULL)
134 		t = meta + len;
135 
136 	if (conf.foreground)
137 		fprintf(stderr, "%s:%s GET %s %.*s\n", hbuf, sbuf, b,
138 		    (int)(t - meta), meta);
139 	else
140 		syslog(LOG_INFO | LOG_DAEMON, "%s:%s GET %s %.*s",
141 		    hbuf, sbuf, b, (int)(t - meta), meta);
142 }
143 
144 void
145 sig_handler(int sig)
146 {
147 	(void)sig;
148 }
149 
150 int
151 starts_with(const char *str, const char *prefix)
152 {
153 	size_t i;
154 
155 	for (i = 0; prefix[i] != '\0'; ++i)
156 		if (str[i] != prefix[i])
157 			return 0;
158 	return 1;
159 }
160 
161 ssize_t
162 filesize(int fd)
163 {
164 	ssize_t len;
165 
166 	if ((len = lseek(fd, 0, SEEK_END)) == -1)
167 		return -1;
168 	if (lseek(fd, 0, SEEK_SET) == -1)
169 		return -1;
170 	return len;
171 }
172 
173 char *
174 absolutify_path(const char *path)
175 {
176 	char *wd, *r;
177 
178 	if (*path == '/')
179 		return strdup(path);
180 
181 	wd = getcwd(NULL, 0);
182 	if (asprintf(&r, "%s/%s", wd, path) == -1)
183 		fatal("asprintf: %s", strerror(errno));
184 	free(wd);
185 	return r;
186 }
187 
188 void
189 yyerror(const char *msg)
190 {
191 	goterror = 1;
192 	fprintf(stderr, "%d: %s\n", yylineno, msg);
193 }
194 
195 int
196 parse_portno(const char *p)
197 {
198 	char *ep;
199 	long lval;
200 
201 	errno = 0;
202 	lval = strtol(p, &ep, 10);
203 	if (p[0] == '\0' || *ep != '\0')
204 		fatal("not a number: %s", p);
205 	if (lval < 0 || lval > UINT16_MAX)
206 		fatal("port number out of range for domain %s: %ld", p, lval);
207 	return lval;
208 }
209 
210 void
211 parse_conf(const char *path)
212 {
213 	if ((yyin = fopen(path, "r")) == NULL)
214 		fatal("cannot open config %s", path);
215 	yyparse();
216 	fclose(yyin);
217 
218 	if (goterror)
219 		exit(1);
220 }
221 
222 void
223 load_vhosts(struct tls_config *tlsconf)
224 {
225 	struct vhost *h;
226 
227 	/* we need to set something, then we can add how many key we want */
228 	if (tls_config_set_keypair_file(tlsconf, hosts->cert, hosts->key))
229 		fatal("tls_config_set_keypair_file failed");
230 
231 	for (h = hosts; h->domain != NULL; ++h) {
232 		if (tls_config_add_keypair_file(tlsconf, h->cert, h->key) == -1)
233 			fatal("failed to load the keypair (%s, %s)",
234 			    h->cert, h->key);
235 
236 		if ((h->dirfd = open(h->dir, O_RDONLY | O_DIRECTORY)) == -1)
237 			fatal("open %s for domain %s", h->dir, h->domain);
238 	}
239 }
240 
241 int
242 make_socket(int port, int family)
243 {
244 	int sock, v;
245 	struct sockaddr_in addr4;
246 	struct sockaddr_in6 addr6;
247 	struct sockaddr *addr;
248 	socklen_t len;
249 
250         switch (family) {
251 	case AF_INET:
252 		bzero(&addr4, sizeof(addr4));
253 		addr4.sin_family = family;
254 		addr4.sin_port = htons(port);
255 		addr4.sin_addr.s_addr = INADDR_ANY;
256 		addr = (struct sockaddr*)&addr4;
257 		len = sizeof(addr4);
258 		break;
259 
260 	case AF_INET6:
261 		bzero(&addr6, sizeof(addr6));
262 		addr6.sin6_family = AF_INET6;
263 		addr6.sin6_port = htons(port);
264 		addr6.sin6_addr = in6addr_any;
265 		addr = (struct sockaddr*)&addr6;
266 		len = sizeof(addr6);
267 		break;
268 
269 	default:
270 		/* unreachable */
271 		abort();
272 	}
273 
274 	if ((sock = socket(family, SOCK_STREAM, 0)) == -1)
275 		fatal("socket: %s", strerror(errno));
276 
277 	v = 1;
278 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &v, sizeof(v)) == -1)
279 		fatal("setsockopt(SO_REUSEADDR): %s", strerror(errno));
280 
281 	v = 1;
282 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &v, sizeof(v)) == -1)
283 		fatal("setsockopt(SO_REUSEPORT): %s", strerror(errno));
284 
285 	mark_nonblock(sock);
286 
287 	if (bind(sock, addr, len) == -1)
288 		fatal("bind: %s", strerror(errno));
289 
290 	if (listen(sock, 16) == -1)
291 		fatal("listen: %s", strerror(errno));
292 
293 	return sock;
294 }
295 
296 int
297 listener_main()
298 {
299 	int sock4, sock6;
300 	struct tls *ctx = NULL;
301 	struct tls_config *tlsconf;
302 
303 	load_default_mime();
304 
305 	if ((tlsconf = tls_config_new()) == NULL)
306 		fatal("tls_config_new");
307 
308 	/* optionally accept client certs, but don't try to verify them */
309 	tls_config_verify_client_optional(tlsconf);
310 	tls_config_insecure_noverifycert(tlsconf);
311 
312 	if (tls_config_set_protocols(tlsconf, conf.protos) == -1)
313 		fatal("tls_config_set_protocols");
314 
315 	if ((ctx = tls_server()) == NULL)
316 		fatal("tls_server failure");
317 
318 	load_vhosts(tlsconf);
319 
320 	if (tls_configure(ctx, tlsconf) == -1)
321 		fatal("tls_configure: %s", tls_error(ctx));
322 
323 	if (!conf.foreground && daemon(0, 1) == -1)
324 		exit(1);
325 
326 	sock4 = make_socket(conf.port, AF_INET);
327 	sock6 = -1;
328 	if (conf.ipv6)
329 		sock6 = make_socket(conf.port, AF_INET6);
330 
331 	sandbox();
332 	loop(ctx, sock4, sock6);
333 
334 	return 0;
335 }
336 
337 void
338 usage(const char *me)
339 {
340 	fprintf(stderr,
341 	    "USAGE: %s [-n] [-c config] | [-6fh] [-C cert] [-d root] [-K key] "
342 	    "[-p port] [-x cgi-bin]\n",
343 	    me);
344 }
345 
346 int
347 main(int argc, char **argv)
348 {
349 	int ch, p[2];
350 	const char *config_path = NULL;
351 	size_t i;
352 	int conftest = 0;
353 
354 	bzero(hosts, sizeof(hosts));
355 	for (i = 0; i < HOSTSLEN; ++i)
356 		hosts[i].dirfd = -1;
357 
358 	conf.foreground = 1;
359 	conf.port = 1965;
360 	conf.ipv6 = 0;
361 	conf.protos = TLS_PROTOCOL_TLSv1_2 | TLS_PROTOCOL_TLSv1_3;
362 
363 	init_mime();
364 
365 	while ((ch = getopt(argc, argv, "6C:c:d:fhK:np:x:")) != -1) {
366 		switch (ch) {
367 		case '6':
368 			conf.ipv6 = 1;
369 			break;
370 
371 		case 'C':
372 			hosts[0].cert = optarg;
373 			break;
374 
375 		case 'c':
376 			config_path = optarg;
377 			break;
378 
379 		case 'd':
380 			free((char*)hosts[0].dir);
381 			if ((hosts[0].dir = absolutify_path(optarg)) == NULL)
382 				fatal("absolutify_path");
383 			break;
384 
385 		case 'f':
386 			conf.foreground = 1;
387 			break;
388 
389 		case 'h':
390 			usage(*argv);
391 			return 0;
392 
393 		case 'K':
394 			hosts[0].key = optarg;
395 			break;
396 
397 		case 'n':
398 			conftest = 1;
399 			break;
400 
401 		case 'p':
402 			conf.port = parse_portno(optarg);
403 			break;
404 
405 		case 'x':
406 			/* drop the starting / (if any) */
407 			if (*optarg == '/')
408 				optarg++;
409 			hosts[0].cgi = optarg;
410 			break;
411 
412 		default:
413 			usage(*argv);
414 			return 1;
415 		}
416 	}
417 
418 	if (config_path != NULL) {
419 		if (hosts[0].cert != NULL || hosts[0].key != NULL ||
420 		    hosts[0].dir != NULL)
421 			fatal("can't specify options in conf mode");
422 		parse_conf(config_path);
423 	} else {
424 		if (hosts[0].cert == NULL || hosts[0].key == NULL ||
425 		    hosts[0].dir == NULL)
426 			fatal("missing cert, key or root directory to serve");
427 		hosts[0].domain = "*";
428 	}
429 
430 	if (conftest) {
431 		puts("config OK");
432 		return 0;
433 	}
434 
435 	signal(SIGPIPE, SIG_IGN);
436 	signal(SIGCHLD, SIG_IGN);
437 
438 #ifdef SIGINFO
439 	signal(SIGINFO, sig_handler);
440 #endif
441 	signal(SIGUSR2, sig_handler);
442 
443 	if (!conf.foreground) {
444 		signal(SIGHUP, SIG_IGN);
445 		if (daemon(1, 1) == -1)
446 			fatal("daemon: %s", strerror(errno));
447 	}
448 
449 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, p) == -1)
450 		fatal("socketpair: %s", strerror(errno));
451 
452 	switch (fork()) {
453 	case -1:
454 		fatal("fork: %s", strerror(errno));
455 
456 	case 0:			/* child */
457 		close(p[0]);
458 		exfd = p[1];
459 		listener_main();
460 		_exit(0);
461 
462 	default:		/* parent */
463 		close(p[1]);
464 		return executor_main(p[0]);
465 	}
466 }