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 void
95 sig_handler(int sig)
96 {
97 	(void)sig;
98 }
99 
100 int
101 starts_with(const char *str, const char *prefix)
102 {
103 	size_t i;
104 
105 	for (i = 0; prefix[i] != '\0'; ++i)
106 		if (str[i] != prefix[i])
107 			return 0;
108 	return 1;
109 }
110 
111 ssize_t
112 filesize(int fd)
113 {
114 	ssize_t len;
115 
116 	if ((len = lseek(fd, 0, SEEK_END)) == -1)
117 		return -1;
118 	if (lseek(fd, 0, SEEK_SET) == -1)
119 		return -1;
120 	return len;
121 }
122 
123 char *
124 absolutify_path(const char *path)
125 {
126 	char *wd, *r;
127 
128 	if (*path == '/')
129 		return strdup(path);
130 
131 	wd = getcwd(NULL, 0);
132 	if (asprintf(&r, "%s/%s", wd, path) == -1)
133 		fatal("asprintf: %s", strerror(errno));
134 	free(wd);
135 	return r;
136 }
137 
138 void
139 yyerror(const char *msg)
140 {
141 	goterror = 1;
142 	fprintf(stderr, "%d: %s\n", yylineno, msg);
143 }
144 
145 int
146 parse_portno(const char *p)
147 {
148 	char *ep;
149 	long lval;
150 
151 	errno = 0;
152 	lval = strtol(p, &ep, 10);
153 	if (p[0] == '\0' || *ep != '\0')
154 		fatal("not a number: %s", p);
155 	if (lval < 0 || lval > UINT16_MAX)
156 		fatal("port number out of range for domain %s: %ld", p, lval);
157 	return lval;
158 }
159 
160 void
161 parse_conf(const char *path)
162 {
163 	if ((yyin = fopen(path, "r")) == NULL)
164 		fatal("cannot open config %s", path);
165 	yyparse();
166 	fclose(yyin);
167 
168 	if (goterror)
169 		exit(1);
170 }
171 
172 void
173 load_vhosts(struct tls_config *tlsconf)
174 {
175 	struct vhost *h;
176 
177 	/* we need to set something, then we can add how many key we want */
178 	if (tls_config_set_keypair_file(tlsconf, hosts->cert, hosts->key))
179 		fatal("tls_config_set_keypair_file failed");
180 
181 	for (h = hosts; h->domain != NULL; ++h) {
182 		if (tls_config_add_keypair_file(tlsconf, h->cert, h->key) == -1)
183 			fatal("failed to load the keypair (%s, %s)",
184 			    h->cert, h->key);
185 
186 		if ((h->dirfd = open(h->dir, O_RDONLY | O_DIRECTORY)) == -1)
187 			fatal("open %s for domain %s", h->dir, h->domain);
188 	}
189 }
190 
191 int
192 make_socket(int port, int family)
193 {
194 	int sock, v;
195 	struct sockaddr_in addr4;
196 	struct sockaddr_in6 addr6;
197 	struct sockaddr *addr;
198 	socklen_t len;
199 
200         switch (family) {
201 	case AF_INET:
202 		bzero(&addr4, sizeof(addr4));
203 		addr4.sin_family = family;
204 		addr4.sin_port = htons(port);
205 		addr4.sin_addr.s_addr = INADDR_ANY;
206 		addr = (struct sockaddr*)&addr4;
207 		len = sizeof(addr4);
208 		break;
209 
210 	case AF_INET6:
211 		bzero(&addr6, sizeof(addr6));
212 		addr6.sin6_family = AF_INET6;
213 		addr6.sin6_port = htons(port);
214 		addr6.sin6_addr = in6addr_any;
215 		addr = (struct sockaddr*)&addr6;
216 		len = sizeof(addr6);
217 		break;
218 
219 	default:
220 		/* unreachable */
221 		abort();
222 	}
223 
224 	if ((sock = socket(family, SOCK_STREAM, 0)) == -1)
225 		fatal("socket: %s", strerror(errno));
226 
227 	v = 1;
228 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &v, sizeof(v)) == -1)
229 		fatal("setsockopt(SO_REUSEADDR): %s", strerror(errno));
230 
231 	v = 1;
232 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &v, sizeof(v)) == -1)
233 		fatal("setsockopt(SO_REUSEPORT): %s", strerror(errno));
234 
235 	mark_nonblock(sock);
236 
237 	if (bind(sock, addr, len) == -1)
238 		fatal("bind: %s", strerror(errno));
239 
240 	if (listen(sock, 16) == -1)
241 		fatal("listen: %s", strerror(errno));
242 
243 	return sock;
244 }
245 
246 int
247 listener_main()
248 {
249 	int sock4, sock6;
250 	struct tls *ctx = NULL;
251 	struct tls_config *tlsconf;
252 
253 	load_default_mime();
254 
255 	if ((tlsconf = tls_config_new()) == NULL)
256 		fatal("tls_config_new");
257 
258 	/* optionally accept client certs, but don't try to verify them */
259 	tls_config_verify_client_optional(tlsconf);
260 	tls_config_insecure_noverifycert(tlsconf);
261 
262 	if (tls_config_set_protocols(tlsconf, conf.protos) == -1)
263 		fatal("tls_config_set_protocols");
264 
265 	if ((ctx = tls_server()) == NULL)
266 		fatal("tls_server failure");
267 
268 	load_vhosts(tlsconf);
269 
270 	if (tls_configure(ctx, tlsconf) == -1)
271 		fatal("tls_configure: %s", tls_error(ctx));
272 
273 	if (!conf.foreground && daemon(0, 1) == -1)
274 		exit(1);
275 
276 	sock4 = make_socket(conf.port, AF_INET);
277 	sock6 = -1;
278 	if (conf.ipv6)
279 		sock6 = make_socket(conf.port, AF_INET6);
280 
281 	sandbox();
282 	loop(ctx, sock4, sock6);
283 
284 	return 0;
285 }
286 
287 void
288 usage(const char *me)
289 {
290 	fprintf(stderr,
291 	    "USAGE: %s [-n] [-c config] | [-6fh] [-C cert] [-d root] [-K key] "
292 	    "[-p port] [-x cgi-bin]\n",
293 	    me);
294 }
295 
296 int
297 main(int argc, char **argv)
298 {
299 	int ch, p[2];
300 	const char *config_path = NULL;
301 	size_t i;
302 	int conftest = 0;
303 
304 	bzero(hosts, sizeof(hosts));
305 	for (i = 0; i < HOSTSLEN; ++i)
306 		hosts[i].dirfd = -1;
307 
308 	conf.foreground = 1;
309 	conf.port = 1965;
310 	conf.ipv6 = 0;
311 	conf.protos = TLS_PROTOCOL_TLSv1_2 | TLS_PROTOCOL_TLSv1_3;
312 
313 	init_mime();
314 
315 	while ((ch = getopt(argc, argv, "6C:c:d:fhK:np:x:")) != -1) {
316 		switch (ch) {
317 		case '6':
318 			conf.ipv6 = 1;
319 			break;
320 
321 		case 'C':
322 			hosts[0].cert = optarg;
323 			break;
324 
325 		case 'c':
326 			config_path = optarg;
327 			break;
328 
329 		case 'd':
330 			free((char*)hosts[0].dir);
331 			if ((hosts[0].dir = absolutify_path(optarg)) == NULL)
332 				fatal("absolutify_path");
333 			break;
334 
335 		case 'f':
336 			conf.foreground = 1;
337 			break;
338 
339 		case 'h':
340 			usage(*argv);
341 			return 0;
342 
343 		case 'K':
344 			hosts[0].key = optarg;
345 			break;
346 
347 		case 'n':
348 			conftest = 1;
349 			break;
350 
351 		case 'p':
352 			conf.port = parse_portno(optarg);
353 			break;
354 
355 		case 'x':
356 			/* drop the starting / (if any) */
357 			if (*optarg == '/')
358 				optarg++;
359 			hosts[0].cgi = optarg;
360 			break;
361 
362 		default:
363 			usage(*argv);
364 			return 1;
365 		}
366 	}
367 
368 	if (config_path != NULL) {
369 		if (hosts[0].cert != NULL || hosts[0].key != NULL ||
370 		    hosts[0].dir != NULL)
371 			fatal("can't specify options in conf mode");
372 		parse_conf(config_path);
373 	} else {
374 		if (hosts[0].cert == NULL || hosts[0].key == NULL ||
375 		    hosts[0].dir == NULL)
376 			fatal("missing cert, key or root directory to serve");
377 		hosts[0].domain = "*";
378 	}
379 
380 	if (conftest) {
381 		puts("config OK");
382 		return 0;
383 	}
384 
385 	signal(SIGPIPE, SIG_IGN);
386 	signal(SIGCHLD, SIG_IGN);
387 
388 #ifdef SIGINFO
389 	signal(SIGINFO, sig_handler);
390 #endif
391 	signal(SIGUSR2, sig_handler);
392 
393 	if (!conf.foreground) {
394 		signal(SIGHUP, SIG_IGN);
395 		if (daemon(1, 1) == -1)
396 			fatal("daemon: %s", strerror(errno));
397 	}
398 
399 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, p) == -1)
400 		fatal("socketpair: %s", strerror(errno));
401 
402 	switch (fork()) {
403 	case -1:
404 		fatal("fork: %s", strerror(errno));
405 
406 	case 0:			/* child */
407 		close(p[0]);
408 		exfd = p[1];
409 		listener_main();
410 		_exit(0);
411 
412 	default:		/* parent */
413 		close(p[1]);
414 		return executor_main(p[0]);
415 	}
416 }