1 /*
2  * Copyright (c) 2022, 2023 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 "gmid.h"
18 
19 #include <sys/stat.h>
20 #include <sys/wait.h>
21 
22 #include <errno.h>
23 #include <fcntl.h>
24 #include <getopt.h>
25 #include <locale.h>
26 #include <libgen.h>
27 #include <signal.h>
28 #include <string.h>
29 #include <syslog.h>
30 #include <unistd.h>
31 #include <vis.h>
32 
33 #include "log.h"
34 
35 static int gen_eckey = 1;
36 
37 int privsep_process;
38 
39 static const struct option opts[] = {
40 	{"help",	no_argument,	NULL,	'h'},
41 	{"version",	no_argument,	NULL,	'V'},
42 	{NULL,		0,		NULL,	0},
43 };
44 
45 void
46 log_request(struct client *c, int code, const char *meta)
47 {
48 	char b[GEMINI_URL_LEN];
49 	char cntmp[64], cn[64] = "-";
50 	const char *t;
51 
52 	if (c->iri.schema != NULL) {
53 		/* serialize the IRI */
54 		strlcpy(b, c->iri.schema, sizeof(b));
55 		strlcat(b, "://", sizeof(b));
56 
57 		/* log the decoded host name, but if it was invalid
58 		 * use the raw one. */
59 		if (*c->domain != '\0')
60 			strlcat(b, c->domain, sizeof(b));
61 		else
62 			strlcat(b, c->iri.host, sizeof(b));
63 
64 		if (*c->iri.path != '/')
65 			strlcat(b, "/", sizeof(b));
66 		strlcat(b, c->iri.path, sizeof(b)); /* TODO: sanitize UTF8 */
67 		if (*c->iri.query != '\0') {	    /* TODO: sanitize UTF8 */
68 			strlcat(b, "?", sizeof(b));
69 			strlcat(b, c->iri.query, sizeof(b));
70 		}
71 	} else {
72 		if ((t = c->req) == NULL)
73 			t = "";
74 		strlcpy(b, t, sizeof(b));
75 	}
76 
77 	if (tls_peer_cert_provided(c->ctx)) {
78 		const char *subj;
79 		char *n;
80 
81 		subj = tls_peer_cert_subject(c->ctx);
82 		if ((n = strstr(subj, "/CN=")) != NULL) {
83 			strlcpy(cntmp, subj + 4, sizeof(cntmp));
84 			if ((n = strchr(cntmp, '/')) != NULL)
85 				*n = '\0';
86 			strnvis(cn, cntmp, sizeof(cn), VIS_WHITE|VIS_DQ);
87 		}
88 	}
89 
90 	fprintf(stderr, "%s %s %s %s %d %s\n", c->rhost, cn,
91 	    *c->domain == '\0' ? c->iri.host : c->domain, b, code, meta);
92 }
93 
94 void
95 load_local_cert(struct vhost *h, const char *hostname, const char *dir)
96 {
97 	char *cert, *key;
98 
99 	if (asprintf(&cert, "%s/%s.pem", dir, hostname) == -1)
100 		fatal("asprintf");
101 	if (asprintf(&key, "%s/%s.key", dir, hostname) == -1)
102 		fatal("asprintf");
103 
104 	if (access(cert, R_OK) == -1 || access(key, R_OK) == -1)
105 		gencert(hostname, cert, key, gen_eckey);
106 
107 	h->cert = tls_load_file(cert, &h->certlen, NULL);
108 	if (h->cert == NULL)
109 		fatal("can't load %s", cert);
110 
111 	h->key = tls_load_file(key, &h->keylen, NULL);
112 	if (h->key == NULL)
113 		fatal("can't load %s", key);
114 
115 	strlcpy(h->domain, hostname, sizeof(h->domain));
116 }
117 
118 /* wrapper around dirname(3).  dn must be PATH_MAX+1 at least. */
119 static void
120 pdirname(const char *path, char *dn)
121 {
122 	char	 p[PATH_MAX+1];
123 	char	*t;
124 
125 	strlcpy(p, path, sizeof(p));
126 	t = dirname(p);
127 	memmove(dn, t, strlen(t)+1);
128 }
129 
130 static void
131 mkdirs(const char *path, mode_t mode)
132 {
133 	char	dname[PATH_MAX+1];
134 
135 	pdirname(path, dname);
136 	if (!strcmp(dname, "/"))
137 		return;
138 	mkdirs(dname, mode);
139 	if (mkdir(path, mode) != 0 && errno != EEXIST)
140 		fatal("can't mkdir %s", path);
141 }
142 
143 /* $XDG_DATA_HOME/gemexp */
144 char *
145 data_dir(void)
146 {
147 	const char *home, *xdg;
148 	char *t;
149 
150 	if ((xdg = getenv("XDG_DATA_HOME")) == NULL) {
151 		if ((home = getenv("HOME")) == NULL)
152 			fatalx("XDG_DATA_HOME and HOME both empty");
153 		if (asprintf(&t, "%s/.local/share/gemexp", home) == -1)
154 			fatalx("asprintf");
155 	} else {
156 		if (asprintf(&t, "%s/gemexp", xdg) == -1)
157 			fatal("asprintf");
158 	}
159 
160 	mkdirs(t, 0755);
161 	return t;
162 }
163 
164 static int
165 serve(struct conf *conf, const char *host, int port, const char *dir)
166 {
167 	struct addrinfo hints, *res, *res0;
168 	struct vhost *vh = TAILQ_FIRST(&conf->hosts);
169 	struct address *addr, *acp;
170 	int r, error, saved_errno, sock = -1;
171 	const char *cause = NULL;
172 	char service[32];
173 	int any = 0;
174 
175 	event_init();
176 
177 	r = snprintf(service, sizeof(service), "%d", port);
178 	if (r < 0 || (size_t)r >= sizeof(service))
179 		fatal("snprintf");
180 
181 	memset(&hints, 0, sizeof(hints));
182 	hints.ai_family = AF_UNSPEC;
183 	hints.ai_socktype = SOCK_STREAM;
184 	hints.ai_flags = AI_PASSIVE;
185 	error = getaddrinfo(host, service, &hints, &res0);
186 	if (error)
187 		fatalx("%s", gai_strerror(error));
188 	for (res = res0; res; res = res->ai_next) {
189 		sock = socket(res->ai_family, res->ai_socktype,
190 		    res->ai_protocol);
191 		if (sock == -1) {
192 			cause = "socket";
193 			continue;
194 		}
195 
196 		if (bind(sock, res->ai_addr, res->ai_addrlen) == -1) {
197 			cause = "bind";
198 			saved_errno = errno;
199 			close(sock);
200 			errno = saved_errno;
201 			continue;
202 		}
203 
204 		if (listen(sock, 5) == -1)
205 			fatal("listen");
206 
207 		any = 1;
208 
209 		addr = xcalloc(1, sizeof(*addr));
210 		addr->ai_flags = res->ai_flags;
211 		addr->ai_family = res->ai_family;
212 		addr->ai_socktype = res->ai_socktype;
213 		addr->ai_protocol = res->ai_protocol;
214 		addr->slen = res->ai_addrlen;
215 		memcpy(&addr->ss, res->ai_addr, res->ai_addrlen);
216 
217 		addr->conf = conf;
218 		addr->sock = sock;
219 		event_set(&addr->evsock, addr->sock, EV_READ|EV_PERSIST,
220 		    server_accept, addr);
221 
222 		if ((addr->ctx = tls_server()) == NULL)
223 			fatal("tls_server failure");
224 
225 		TAILQ_INSERT_HEAD(&conf->addrs, addr, addrs);
226 
227 		acp = xcalloc(1, sizeof(*acp));
228 		memcpy(acp, addr, sizeof(*acp));
229 		acp->sock = -1;
230 		memset(&acp->evsock, 0, sizeof(acp->evsock));
231 		TAILQ_INSERT_HEAD(&vh->addrs, addr, addrs);
232 	}
233 
234 	if (!any)
235 		fatal("%s", cause);
236 	freeaddrinfo(res0);
237 
238 	server_init(NULL, NULL, NULL);
239 	if (server_configure_done(conf) == -1)
240 		fatalx("server configuration failed");
241 
242 	log_info("serving %s on port %d", dir, port);
243 	event_dispatch();
244 	log_info("quitting");
245 	return 0;
246 }
247 
248 static __dead void
249 usage(void)
250 {
251 	fprintf(stderr,
252 	    "Version: " GEMEXP_STRING "\n"
253 	    "Usage: %s [-hRV] [-d certs-dir] [-H hostname] [-p port] [dir]\n",
254 	    getprogname());
255 	exit(1);
256 }
257 
258 int
259 main(int argc, char **argv)
260 {
261 	struct conf *conf;
262 	struct vhost *host;
263 	struct location *loc;
264 	const char *errstr, *certs_dir = NULL, *hostname = "localhost";
265 	char path[PATH_MAX];
266 	int ch, port = 1965;
267 
268 	setlocale(LC_CTYPE, "");
269 
270 	log_init(1, LOG_DAEMON);
271 	log_setverbose(0);
272 	conf = config_new();
273 
274 	/* ge doesn't do privsep so no privsep crypto engine. */
275 	conf->use_privsep_crypto = 0;
276 
277 	while ((ch = getopt_long(argc, argv, "d:H:hp:RV", opts, NULL)) != -1) {
278 		switch (ch) {
279 		case 'd':
280 			certs_dir = optarg;
281 			break;
282 		case 'H':
283 			hostname = optarg;
284 			break;
285 		case 'h':
286 			usage();
287 			break;
288 		case 'p':
289 			port = strtonum(optarg, 0, UINT16_MAX, &errstr);
290 			if (errstr)
291 				fatalx("port number is %s: %s", errstr,
292 				    optarg);
293 			break;
294 		case 'R':
295 			gen_eckey = 0;
296 			break;
297 		case 'V':
298 			puts("Version: " GEMEXP_STRING);
299 			return 0;
300 		default:
301 			usage();
302 			break;
303 		}
304 	}
305 	argc -= optind;
306 	argv += optind;
307 
308 	if (argc > 1)
309 		usage();
310 
311 	/* prepare the configuration */
312 	init_mime(&conf->mime);
313 
314 	if (certs_dir == NULL)
315 		certs_dir = data_dir();
316 
317 	/* set up the implicit vhost and location */
318 	host = xcalloc(1, sizeof(*host));
319 	TAILQ_INSERT_HEAD(&conf->hosts, host, vhosts);
320 
321 	loc = xcalloc(1, sizeof(*loc));
322 	loc->fcgi = -1;
323 	TAILQ_INSERT_HEAD(&host->locations, loc, locations);
324 
325 	load_local_cert(host, hostname, certs_dir);
326 
327 	strlcpy(host->domain, "*", sizeof(host->domain));
328 	loc->auto_index = 1;
329 	strlcpy(loc->match, "*", sizeof(loc->match));
330 
331 	if (*argv == NULL) {
332 		if (getcwd(path, sizeof(path)) == NULL)
333 			fatal("getcwd");
334 		strlcpy(loc->dir, path, sizeof(loc->dir));
335 	} else {
336 		char	*tmp;
337 
338 		tmp = absolutify_path(*argv);
339 		strlcpy(loc->dir, tmp, sizeof(loc->dir));
340 		free(tmp);
341 	}
342 
343 	/* start the server */
344 	signal(SIGPIPE, SIG_IGN);
345 	setproctitle("%s", loc->dir);
346 	return serve(conf, hostname, port, loc->dir);
347 }