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