1 /*
2  * Copyright (c) 2021 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/socket.h>
20 
21 #include <assert.h>
22 #include <ctype.h>
23 #include <errno.h>
24 #include <locale.h>
25 #include <string.h>
26 
27 enum debug {
28 	DEBUG_NONE,
29 	DEBUG_CODE,
30 	DEBUG_HEADER,
31 	DEBUG_META,
32 	DEBUG_ALL,
33 };
34 
35 /* flags */
36 int		 debug;
37 int		 dont_verify_name;
38 int		 flag2;
39 int		 flag3;
40 int		 nop;
41 int		 redirects = 5;
42 int		 timer;
43 const char	*cert;
44 const char	*key;
45 const char	*proxy_host;
46 const char	*proxy_port;
47 const char	*sni;
48 
49 /* state */
50 struct tls_config *tls_conf;
51 
52 static void
53 timeout(int signo)
54 {
55 	dprintf(2, "%s: timer expired\n", getprogname());
56 	exit(1);
57 }
58 
59 static void
60 load_tls_conf(void)
61 {
62 	if ((tls_conf = tls_config_new()) == NULL)
63 		err(1, "tls_config_new");
64 
65 	tls_config_insecure_noverifycert(tls_conf);
66 	if (dont_verify_name)
67 		tls_config_insecure_noverifyname(tls_conf);
68 
69 	if (flag2 &&
70 	    tls_config_set_protocols(tls_conf, TLS_PROTOCOL_TLSv1_2) == -1)
71 		errx(1, "can't set TLSv1.2");
72 	if (flag3 &&
73 	    tls_config_set_protocols(tls_conf, TLS_PROTOCOL_TLSv1_3) == -1)
74 		errx(1, "can't set TLSv1.3");
75 
76 	if (cert != NULL &&
77 	    tls_config_set_keypair_file(tls_conf, cert, key) == -1)
78 		errx(1, "can't load client certificate %s", cert);
79 }
80 
81 static void
82 connectto(struct tls *ctx, const char *host, const char *port)
83 {
84 	struct addrinfo hints, *res, *res0;
85 	int error;
86 	int saved_errno;
87 	int s;
88 	const char *cause = NULL;
89 	const char *sname;
90 
91 	if (proxy_host != NULL) {
92 		host = proxy_host;
93 		port = proxy_port;
94 	}
95 
96 	if ((sname = sni) == NULL)
97 		sname = host;
98 
99 	memset(&hints, 0, sizeof(hints));
100 	hints.ai_family = AF_UNSPEC;
101 	hints.ai_socktype = SOCK_STREAM;
102 	error = getaddrinfo(host, port, &hints, &res0);
103 	if (error)
104 		errx(1, "%s", gai_strerror(error));
105 
106 	s = -1;
107 	for (res = res0; res != NULL; res = res->ai_next) {
108 		s = socket(res->ai_family, res->ai_socktype,
109 		    res->ai_protocol);
110 		if (s == -1) {
111 			cause = "socket";
112 			continue;
113 		}
114 
115 		if (connect(s, res->ai_addr, res->ai_addrlen) == -1) {
116 			cause = "connect";
117 			saved_errno = errno;
118 			close(s);
119 			errno = saved_errno;
120 			s = -1;
121 			continue;
122 		}
123 
124 		break;
125 	}
126 
127 	if (s == -1)
128 		err(1, "%s: can't connect to %s:%s", cause,
129 		    host, port);
130 
131 	freeaddrinfo(res0);
132 
133 	if (tls_connect_socket(ctx, s, sname) == -1)
134 		errx(1, "tls_connect_socket: %s", tls_error(ctx));
135 }
136 
137 static void
138 doreq(struct tls *ctx, const char *buf)
139 {
140 	size_t	s;
141 	ssize_t	w;
142 
143 	s = strlen(buf);
144 	while (s != 0) {
145 		switch (w = tls_write(ctx, buf, s)) {
146 		case 0:
147 		case -1:
148 			errx(1, "tls_write: %s", tls_error(ctx));
149 		case TLS_WANT_POLLIN:
150 		case TLS_WANT_POLLOUT:
151 			continue;
152 		}
153 
154 		s -= w;
155 		buf += w;
156 	}
157 }
158 
159 static size_t
160 dorep(struct tls *ctx, uint8_t *buf, size_t len)
161 {
162 	ssize_t	w;
163 	size_t	tot = 0;
164 
165 	while (len != 0) {
166 		switch (w = tls_read(ctx, buf, len)) {
167 		case 0:
168 			return tot;
169 		case -1:
170 			errx(1, "tls_write: %s", tls_error(ctx));
171 		case TLS_WANT_POLLIN:
172 		case TLS_WANT_POLLOUT:
173 			continue;
174 		}
175 
176 		len -= w;
177 		buf += w;
178 		tot += w;
179 	}
180 
181 	return tot;
182 }
183 
184 static int
185 get(const char *r)
186 {
187 	struct tls	*ctx;
188 	struct iri	 iri;
189 	int		 foundhdr = 0, code = -1, od;
190 	char		 iribuf[GEMINI_URL_LEN];
191 	char		 req[GEMINI_URL_LEN];
192 	uint8_t		 buf[2048];
193 	const char	*parse_err, *host, *port;
194 
195 	if (strlcpy(iribuf, r, sizeof(iribuf)) >= sizeof(iribuf))
196 		errx(1, "iri too long: %s", r);
197 
198 	if (strlcpy(req, r, sizeof(req)) >= sizeof(req))
199 		errx(1, "iri too long: %s", r);
200 
201 	if (strlcat(req, "\r\n", sizeof(req)) >= sizeof(req))
202 		errx(1, "iri too long: %s", r);
203 
204 	if (!parse_iri(iribuf, &iri, &parse_err))
205 		errx(1, "invalid IRI: %s", parse_err);
206 
207 	if (nop)
208 		errx(0, "IRI OK");
209 
210 	if ((ctx = tls_client()) == NULL)
211 		errx(1, "can't create tls context");
212 
213 	if (tls_configure(ctx, tls_conf) == -1)
214 		errx(1, "tls_configure: %s", tls_error(ctx));
215 
216 	host = iri.host;
217 	port = "1965";
218 	if (*iri.port != '\0')
219 		port = iri.port;
220 
221 	connectto(ctx, host, port);
222 
223 	od = 0;
224 	while (!od) {
225 		switch (tls_handshake(ctx)) {
226 		case 0:
227 			od = 1;
228 			break;
229 		case -1:
230 			errx(1, "handshake: %s", tls_error(ctx));
231 		}
232 	}
233 
234 	doreq(ctx, req);
235 
236 	for (;;) {
237 		uint8_t	*t;
238 		size_t	 len;
239 
240 		len = dorep(ctx, buf, sizeof(buf));
241 		if (len == 0)
242 			goto close;
243 
244 		if (foundhdr) {
245 			write(1, buf, len);
246 			continue;
247 		}
248 		foundhdr = 1;
249 
250 		if (memmem(buf, len, "\r\n", 2) == NULL)
251 			errx(1, "invalid reply: no \\r\\n");
252 		if (!isdigit((unsigned char)buf[0]) ||
253 		    !isdigit((unsigned char)buf[1]) ||
254 		    buf[2] != ' ')
255 			errx(1, "invalid reply: invalid response format");
256 
257 		code = (buf[0] - '0') * 10 + buf[1] - '0';
258 
259 		if (debug == DEBUG_CODE) {
260 			printf("%d\n", code);
261 			goto close;
262 		}
263 
264 		if (debug == DEBUG_HEADER) {
265 			t = memmem(buf, len, "\r\n", 2);
266 			assert(t != NULL);
267 			*t = '\0';
268 			printf("%s\n", buf);
269 			goto close;
270 		}
271 
272 		if (debug == DEBUG_META) {
273 			t = memmem(buf, len, "\r\n", 2);
274 			assert(t != NULL);
275 			*t = '\0';
276 			printf("%s\n", buf+3);
277 			goto close;
278 		}
279 
280 		if (debug == DEBUG_ALL) {
281 			write(1, buf, len);
282 			continue;
283 		}
284 
285 		/* skip the header */
286 		t = memmem(buf, len, "\r\n", 2);
287 		assert(t != NULL);
288 		t += 2; /* skip \r\n */
289 		len -= t - buf;
290 		write(1, t, len);
291 	}
292 
293 close:
294 	od = tls_close(ctx);
295 	if (od == TLS_WANT_POLLIN || od == TLS_WANT_POLLOUT)
296 		goto close;
297 
298 	tls_close(ctx);
299 	tls_free(ctx);
300 	return code;
301 }
302 
303 static void __attribute__((noreturn))
304 usage(void)
305 {
306 	fprintf(stderr, "version: " GG_STRING "\n");
307 	fprintf(stderr, "usage: %s [-23Nn] [-C cert] [-d mode] [-H sni] "
308 	    "[-K key] [-P host[:port]]\n",
309 	    getprogname());
310 	fprintf(stderr, "          [-T seconds] gemini://...\n");
311 	exit(1);
312 }
313 
314 static int
315 parse_debug(const char *arg)
316 {
317 	if (!strcmp(arg, "none"))
318 		return DEBUG_NONE;
319 	if (!strcmp(arg, "code"))
320 		return DEBUG_CODE;
321 	if (!strcmp(arg, "header"))
322 		return DEBUG_HEADER;
323 	if (!strcmp(arg, "meta"))
324 		return DEBUG_META;
325 	if (!strcmp(arg, "all"))
326 		return DEBUG_ALL;
327 	usage();
328 }
329 
330 static void
331 parse_proxy(const char *arg)
332 {
333 	char *at;
334 
335 	if ((proxy_host = strdup(arg)) == NULL)
336 		err(1, "strdup");
337 
338 	proxy_port = "1965";
339 
340 	if ((at = strchr(proxy_host, ':')) == NULL)
341 		return;
342 	*at = '\0';
343 	proxy_port = ++at;
344 
345 	if (strchr(proxy_port, ':') != NULL)
346 		errx(1, "invalid port %s", proxy_port);
347 }
348 
349 int
350 main(int argc, char **argv)
351 {
352 	int		 ch, code;
353 	const char	*errstr;
354 
355 	setlocale(LC_CTYPE, "");
356 
357 	while ((ch = getopt(argc, argv, "23C:d:H:K:NP:T:")) != -1) {
358 		switch (ch) {
359 		case '2':
360 			flag2 = 1;
361 			break;
362 		case '3':
363 			flag3 = 1;
364 			break;
365 		case 'C':
366 			cert = optarg;
367 			break;
368 		case 'd':
369 			debug = parse_debug(optarg);
370 			break;
371 		case 'H':
372 			sni = optarg;
373 			break;
374 		case 'K':
375 			key = optarg;
376 			break;
377 		case 'N':
378 			dont_verify_name = 1;
379 			break;
380 		case 'n':
381 			nop = 1;
382 			break;
383 		case 'P':
384 			parse_proxy(optarg);
385 			dont_verify_name = 1;
386 			break;
387 		case 'T':
388 			timer = strtonum(optarg, 1, 1000, &errstr);
389 			if (errstr != NULL)
390 				errx(1, "timeout is %s: %s",
391 				    errstr, optarg);
392 			signal(SIGALRM, timeout);
393 			alarm(timer);
394 			break;
395 		default:
396 			usage();
397 		}
398 	}
399 	argc -= optind;
400 	argv += optind;
401 
402 	if (flag2 + flag3 > 1) {
403 		warnx("only -2 or -3 can be specified at the same time");
404 		usage();
405 	}
406 
407 	if ((cert != NULL && key == NULL) ||
408 	    (cert == NULL && key != NULL)) {
409 		warnx("cert or key is missing");
410 		usage();
411 	}
412 
413 	if (argc != 1)
414 		usage();
415 
416 	load_tls_conf();
417 
418 	signal(SIGPIPE, SIG_IGN);
419 
420 #ifdef __OpenBSD__
421 	if (pledge("stdio inet dns", NULL) == -1)
422 		err(1, "pledge");
423 #endif
424 
425 	code = get(*argv);
426 
427 	return code < 20 || code >= 30;
428 }