xref: /freebsd/lib/libfetch/common.c (revision 9f23cbd6cae82fd77edfad7173432fa8dccd0a95)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1998-2016 Dag-Erling Smørgrav
5  * Copyright (c) 2013 Michael Gmelin <freebsd@grem.de>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer
13  *    in this position and unchanged.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. The name of the author may not be used to endorse or promote products
18  *    derived from this software without specific prior written permission
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/param.h>
36 #include <sys/socket.h>
37 #include <sys/time.h>
38 #include <sys/uio.h>
39 
40 #include <netinet/in.h>
41 
42 #include <ctype.h>
43 #include <errno.h>
44 #include <fcntl.h>
45 #include <inttypes.h>
46 #include <netdb.h>
47 #include <paths.h>
48 #include <poll.h>
49 #include <pwd.h>
50 #include <stdarg.h>
51 #include <stdlib.h>
52 #include <stdio.h>
53 #include <string.h>
54 #include <unistd.h>
55 
56 #ifdef WITH_SSL
57 #include <openssl/x509v3.h>
58 #endif
59 
60 #include "fetch.h"
61 #include "common.h"
62 
63 
64 /*** Local data **************************************************************/
65 
66 /*
67  * Error messages for resolver errors
68  */
69 static struct fetcherr netdb_errlist[] = {
70 #ifdef EAI_ADDRFAMILY
71 	{ EAI_ADDRFAMILY, FETCH_RESOLV, "Address family for host not supported" },
72 #endif
73 #ifdef EAI_NODATA
74 	{ EAI_NODATA,	FETCH_RESOLV,	"No address for host" },
75 #endif
76 	{ EAI_AGAIN,	FETCH_TEMP,	"Transient resolver failure" },
77 	{ EAI_FAIL,	FETCH_RESOLV,	"Non-recoverable resolver failure" },
78 	{ EAI_NONAME,	FETCH_RESOLV,	"Host does not resolve" },
79 	{ -1,		FETCH_UNKNOWN,	"Unknown resolver error" }
80 };
81 
82 /*
83  * SOCKS5 error enumerations
84  */
85 enum SOCKS5_ERR {
86 /* Protocol errors */
87 	SOCKS5_ERR_SELECTION,
88 	SOCKS5_ERR_READ_METHOD,
89 	SOCKS5_ERR_VER5_ONLY,
90 	SOCKS5_ERR_NOMETHODS,
91 	SOCKS5_ERR_NOTIMPLEMENTED,
92 	SOCKS5_ERR_HOSTNAME_SIZE,
93 	SOCKS5_ERR_REQUEST,
94 	SOCKS5_ERR_REPLY,
95 	SOCKS5_ERR_NON_VER5_RESP,
96 	SOCKS5_ERR_GENERAL,
97 	SOCKS5_ERR_NOT_ALLOWED,
98 	SOCKS5_ERR_NET_UNREACHABLE,
99 	SOCKS5_ERR_HOST_UNREACHABLE,
100 	SOCKS5_ERR_CONN_REFUSED,
101 	SOCKS5_ERR_TTL_EXPIRED,
102 	SOCKS5_ERR_COM_UNSUPPORTED,
103 	SOCKS5_ERR_ADDR_UNSUPPORTED,
104 	SOCKS5_ERR_UNSPECIFIED,
105 /* Configuration errors */
106 	SOCKS5_ERR_BAD_HOST,
107 	SOCKS5_ERR_BAD_PROXY_FORMAT,
108 	SOCKS5_ERR_BAD_PORT
109 };
110 
111 /*
112  * Error messages for SOCKS5 errors
113  */
114 static struct fetcherr socks5_errlist[] = {
115 /* SOCKS5 protocol errors */
116 	{ SOCKS5_ERR_SELECTION,		FETCH_ABORT,	"SOCKS5: Failed to send selection method" },
117 	{ SOCKS5_ERR_READ_METHOD,	FETCH_ABORT,	"SOCKS5: Failed to read method" },
118 	{ SOCKS5_ERR_VER5_ONLY,		FETCH_PROTO,	"SOCKS5: Only version 5 is implemented" },
119 	{ SOCKS5_ERR_NOMETHODS,		FETCH_PROTO,	"SOCKS5: No acceptable methods" },
120 	{ SOCKS5_ERR_NOTIMPLEMENTED,	FETCH_PROTO,	"SOCKS5: Method currently not implemented" },
121 	{ SOCKS5_ERR_HOSTNAME_SIZE,	FETCH_PROTO,	"SOCKS5: Hostname size is above 256 bytes" },
122 	{ SOCKS5_ERR_REQUEST,		FETCH_PROTO,	"SOCKS5: Failed to request" },
123 	{ SOCKS5_ERR_REPLY,		FETCH_PROTO,	"SOCKS5: Failed to receive reply" },
124 	{ SOCKS5_ERR_NON_VER5_RESP,	FETCH_PROTO,	"SOCKS5: Server responded with a non-version 5 response" },
125 	{ SOCKS5_ERR_GENERAL,		FETCH_ABORT,	"SOCKS5: General server failure" },
126 	{ SOCKS5_ERR_NOT_ALLOWED,	FETCH_AUTH,	"SOCKS5: Connection not allowed by ruleset" },
127 	{ SOCKS5_ERR_NET_UNREACHABLE,	FETCH_NETWORK,	"SOCKS5: Network unreachable" },
128 	{ SOCKS5_ERR_HOST_UNREACHABLE,	FETCH_ABORT,	"SOCKS5: Host unreachable" },
129 	{ SOCKS5_ERR_CONN_REFUSED,	FETCH_ABORT,	"SOCKS5: Connection refused" },
130 	{ SOCKS5_ERR_TTL_EXPIRED,	FETCH_TIMEOUT,	"SOCKS5: TTL expired" },
131 	{ SOCKS5_ERR_COM_UNSUPPORTED,	FETCH_PROTO,	"SOCKS5: Command not supported" },
132 	{ SOCKS5_ERR_ADDR_UNSUPPORTED,	FETCH_ABORT,	"SOCKS5: Address type not supported" },
133 	{ SOCKS5_ERR_UNSPECIFIED,	FETCH_UNKNOWN,	"SOCKS5: Unspecified error" },
134 /* Configuration error */
135 	{ SOCKS5_ERR_BAD_HOST,		FETCH_ABORT,	"SOCKS5: Bad proxy host" },
136 	{ SOCKS5_ERR_BAD_PROXY_FORMAT,	FETCH_ABORT,	"SOCKS5: Bad proxy format" },
137 	{ SOCKS5_ERR_BAD_PORT,		FETCH_ABORT,	"SOCKS5: Bad port" }
138 };
139 
140 /* End-of-Line */
141 static const char ENDL[2] = "\r\n";
142 
143 
144 /*** Error-reporting functions ***********************************************/
145 
146 /*
147  * Map error code to string
148  */
149 static struct fetcherr *
150 fetch_finderr(struct fetcherr *p, int e)
151 {
152 	while (p->num != -1 && p->num != e)
153 		p++;
154 	return (p);
155 }
156 
157 /*
158  * Set error code
159  */
160 void
161 fetch_seterr(struct fetcherr *p, int e)
162 {
163 	p = fetch_finderr(p, e);
164 	fetchLastErrCode = p->cat;
165 	snprintf(fetchLastErrString, MAXERRSTRING, "%s", p->string);
166 }
167 
168 /*
169  * Set error code according to errno
170  */
171 void
172 fetch_syserr(void)
173 {
174 	switch (errno) {
175 	case 0:
176 		fetchLastErrCode = FETCH_OK;
177 		break;
178 	case EPERM:
179 	case EACCES:
180 	case EROFS:
181 	case EAUTH:
182 	case ENEEDAUTH:
183 		fetchLastErrCode = FETCH_AUTH;
184 		break;
185 	case ENOENT:
186 	case EISDIR: /* XXX */
187 		fetchLastErrCode = FETCH_UNAVAIL;
188 		break;
189 	case ENOMEM:
190 		fetchLastErrCode = FETCH_MEMORY;
191 		break;
192 	case EBUSY:
193 	case EAGAIN:
194 		fetchLastErrCode = FETCH_TEMP;
195 		break;
196 	case EEXIST:
197 		fetchLastErrCode = FETCH_EXISTS;
198 		break;
199 	case ENOSPC:
200 		fetchLastErrCode = FETCH_FULL;
201 		break;
202 	case EADDRINUSE:
203 	case EADDRNOTAVAIL:
204 	case ENETDOWN:
205 	case ENETUNREACH:
206 	case ENETRESET:
207 	case EHOSTUNREACH:
208 		fetchLastErrCode = FETCH_NETWORK;
209 		break;
210 	case ECONNABORTED:
211 	case ECONNRESET:
212 		fetchLastErrCode = FETCH_ABORT;
213 		break;
214 	case ETIMEDOUT:
215 		fetchLastErrCode = FETCH_TIMEOUT;
216 		break;
217 	case ECONNREFUSED:
218 	case EHOSTDOWN:
219 		fetchLastErrCode = FETCH_DOWN;
220 		break;
221 	default:
222 		fetchLastErrCode = FETCH_UNKNOWN;
223 	}
224 	snprintf(fetchLastErrString, MAXERRSTRING, "%s", strerror(errno));
225 }
226 
227 
228 /*
229  * Emit status message
230  */
231 void
232 fetch_info(const char *fmt, ...)
233 {
234 	va_list ap;
235 
236 	va_start(ap, fmt);
237 	vfprintf(stderr, fmt, ap);
238 	va_end(ap);
239 	fputc('\n', stderr);
240 }
241 
242 
243 /*** Network-related utility functions ***************************************/
244 
245 /*
246  * Return the default port for a scheme
247  */
248 int
249 fetch_default_port(const char *scheme)
250 {
251 	struct servent *se;
252 
253 	if ((se = getservbyname(scheme, "tcp")) != NULL)
254 		return (ntohs(se->s_port));
255 	if (strcmp(scheme, SCHEME_FTP) == 0)
256 		return (FTP_DEFAULT_PORT);
257 	if (strcmp(scheme, SCHEME_HTTP) == 0)
258 		return (HTTP_DEFAULT_PORT);
259 	return (0);
260 }
261 
262 /*
263  * Return the default proxy port for a scheme
264  */
265 int
266 fetch_default_proxy_port(const char *scheme)
267 {
268 	if (strcmp(scheme, SCHEME_FTP) == 0)
269 		return (FTP_DEFAULT_PROXY_PORT);
270 	if (strcmp(scheme, SCHEME_HTTP) == 0)
271 		return (HTTP_DEFAULT_PROXY_PORT);
272 	return (0);
273 }
274 
275 
276 /*
277  * Create a connection for an existing descriptor.
278  */
279 conn_t *
280 fetch_reopen(int sd)
281 {
282 	conn_t *conn;
283 	int opt = 1;
284 
285 	/* allocate and fill connection structure */
286 	if ((conn = calloc(1, sizeof(*conn))) == NULL)
287 		return (NULL);
288 	fcntl(sd, F_SETFD, FD_CLOEXEC);
289 	setsockopt(sd, SOL_SOCKET, SO_NOSIGPIPE, &opt, sizeof opt);
290 	conn->sd = sd;
291 	++conn->ref;
292 	return (conn);
293 }
294 
295 
296 /*
297  * Bump a connection's reference count.
298  */
299 conn_t *
300 fetch_ref(conn_t *conn)
301 {
302 
303 	++conn->ref;
304 	return (conn);
305 }
306 
307 
308 /*
309  * Resolve an address
310  */
311 struct addrinfo *
312 fetch_resolve(const char *addr, int port, int af)
313 {
314 	char hbuf[256], sbuf[8];
315 	struct addrinfo hints, *res;
316 	const char *hb, *he, *sep;
317 	const char *host, *service;
318 	int err, len;
319 
320 	/* first, check for a bracketed IPv6 address */
321 	if (*addr == '[') {
322 		hb = addr + 1;
323 		if ((sep = strchr(hb, ']')) == NULL) {
324 			errno = EINVAL;
325 			goto syserr;
326 		}
327 		he = sep++;
328 	} else {
329 		hb = addr;
330 		sep = strchrnul(hb, ':');
331 		he = sep;
332 	}
333 
334 	/* see if we need to copy the host name */
335 	if (*he != '\0') {
336 		len = snprintf(hbuf, sizeof(hbuf),
337 		    "%.*s", (int)(he - hb), hb);
338 		if (len < 0)
339 			goto syserr;
340 		if (len >= (int)sizeof(hbuf)) {
341 			errno = ENAMETOOLONG;
342 			goto syserr;
343 		}
344 		host = hbuf;
345 	} else {
346 		host = hb;
347 	}
348 
349 	/* was it followed by a service name? */
350 	if (*sep == '\0' && port != 0) {
351 		if (port < 1 || port > 65535) {
352 			errno = EINVAL;
353 			goto syserr;
354 		}
355 		if (snprintf(sbuf, sizeof(sbuf), "%d", port) < 0)
356 			goto syserr;
357 		service = sbuf;
358 	} else if (*sep != '\0') {
359 		service = sep + 1;
360 	} else {
361 		service = NULL;
362 	}
363 
364 	/* resolve */
365 	memset(&hints, 0, sizeof(hints));
366 	hints.ai_family = af;
367 	hints.ai_socktype = SOCK_STREAM;
368 	hints.ai_flags = AI_ADDRCONFIG;
369 	if ((err = getaddrinfo(host, service, &hints, &res)) != 0) {
370 		netdb_seterr(err);
371 		return (NULL);
372 	}
373 	return (res);
374 syserr:
375 	fetch_syserr();
376 	return (NULL);
377 }
378 
379 
380 /*
381  * Bind a socket to a specific local address
382  */
383 int
384 fetch_bind(int sd, int af, const char *addr)
385 {
386 	struct addrinfo *cliai, *ai;
387 	int err;
388 
389 	if ((cliai = fetch_resolve(addr, 0, af)) == NULL)
390 		return (-1);
391 	for (ai = cliai; ai != NULL; ai = ai->ai_next)
392 		if ((err = bind(sd, ai->ai_addr, ai->ai_addrlen)) == 0)
393 			break;
394 	if (err != 0)
395 		fetch_syserr();
396 	freeaddrinfo(cliai);
397 	return (err == 0 ? 0 : -1);
398 }
399 
400 
401 /*
402  * SOCKS5 connection initiation, based on RFC 1928
403  * Default DNS resolution over SOCKS5
404  */
405 int
406 fetch_socks5_init(conn_t *conn, const char *host, int port, int verbose)
407 {
408 	/*
409 	 * Size is based on largest packet prefix (4 bytes) +
410 	 * Largest FQDN (256) + one byte size (1) +
411 	 * Port (2)
412 	 */
413 	unsigned char buf[BUFF_SIZE];
414 	unsigned char *ptr;
415 	int ret = 1;
416 
417 	if (verbose)
418 		fetch_info("Initializing SOCKS5 connection: %s:%d", host, port);
419 
420 	/* Connection initialization */
421 	ptr = buf;
422 	*ptr++ = SOCKS_VERSION_5;
423 	*ptr++ = SOCKS_CONNECTION;
424 	*ptr++ = SOCKS_RSV;
425 
426 	if (fetch_write(conn, buf, 3) != 3) {
427 		ret = SOCKS5_ERR_SELECTION;
428 		goto fail;
429 	}
430 
431 	/* Verify response from SOCKS5 server */
432 	if (fetch_read(conn, buf, 2) != 2) {
433 		ret = SOCKS5_ERR_READ_METHOD;
434 		goto fail;
435 	}
436 
437 	ptr = buf;
438 	if (ptr[0] != SOCKS_VERSION_5) {
439 		ret = SOCKS5_ERR_VER5_ONLY;
440 		goto fail;
441 	}
442 	if (ptr[1] == SOCKS_NOMETHODS) {
443 		ret = SOCKS5_ERR_NOMETHODS;
444 		goto fail;
445 	}
446 	else if (ptr[1] != SOCKS5_NOTIMPLEMENTED) {
447 		ret = SOCKS5_ERR_NOTIMPLEMENTED;
448 		goto fail;
449 	}
450 
451 	/* Send Request */
452 	*ptr++ = SOCKS_VERSION_5;
453 	*ptr++ = SOCKS_CONNECTION;
454 	*ptr++ = SOCKS_RSV;
455 	/* Encode all targets as a hostname to avoid DNS leaks */
456 	*ptr++ = SOCKS_ATYP_DOMAINNAME;
457 	if (strlen(host) > FQDN_SIZE) {
458 		ret = SOCKS5_ERR_HOSTNAME_SIZE;
459 		goto fail;
460 	}
461 	*ptr++ = strlen(host);
462 	memcpy(ptr, host, strlen(host));
463 	ptr = ptr + strlen(host);
464 
465 	port = htons(port);
466 	*ptr++ = port & 0x00ff;
467 	*ptr++ = (port & 0xff00) >> 8;
468 
469 	if (fetch_write(conn, buf, ptr - buf) != ptr - buf) {
470 		ret = SOCKS5_ERR_REQUEST;
471 		goto fail;
472 	}
473 
474 	/* BND.ADDR is variable length, read the largest on non-blocking socket */
475 	if (!fetch_read(conn, buf, BUFF_SIZE)) {
476 		ret = SOCKS5_ERR_REPLY;
477 		goto fail;
478 	}
479 
480 	ptr = buf;
481 	if (*ptr++ != SOCKS_VERSION_5) {
482 		ret = SOCKS5_ERR_NON_VER5_RESP;
483 		goto fail;
484 	}
485 
486 	switch(*ptr++) {
487 	case SOCKS_SUCCESS:
488 		break;
489 	case SOCKS_GENERAL_FAILURE:
490 		ret = SOCKS5_ERR_GENERAL;
491 		goto fail;
492 	case SOCKS_CONNECTION_NOT_ALLOWED:
493 		ret = SOCKS5_ERR_NOT_ALLOWED;
494 		goto fail;
495 	case SOCKS_NETWORK_UNREACHABLE:
496 		ret = SOCKS5_ERR_NET_UNREACHABLE;
497 		goto fail;
498 	case SOCKS_HOST_UNREACHABLE:
499 		ret = SOCKS5_ERR_HOST_UNREACHABLE;
500 		goto fail;
501 	case SOCKS_CONNECTION_REFUSED:
502 		ret = SOCKS5_ERR_CONN_REFUSED;
503 		goto fail;
504 	case SOCKS_TTL_EXPIRED:
505 		ret = SOCKS5_ERR_TTL_EXPIRED;
506 		goto fail;
507 	case SOCKS_COMMAND_NOT_SUPPORTED:
508 		ret = SOCKS5_ERR_COM_UNSUPPORTED;
509 		goto fail;
510 	case SOCKS_ADDRESS_NOT_SUPPORTED:
511 		ret = SOCKS5_ERR_ADDR_UNSUPPORTED;
512 		goto fail;
513 	default:
514 		ret = SOCKS5_ERR_UNSPECIFIED;
515 		goto fail;
516 	}
517 
518 	return (ret);
519 
520 fail:
521 	socks5_seterr(ret);
522 	return (0);
523 }
524 
525 /*
526  * Perform SOCKS5 initialization
527  */
528 int
529 fetch_socks5_getenv(char **host, int *port)
530 {
531 	char *socks5env, *endptr, *ext;
532 	const char *portDelim;
533 	size_t slen;
534 
535 	portDelim = ":";
536 	if ((socks5env = getenv("SOCKS5_PROXY")) == NULL || *socks5env == '\0') {
537 		*host = NULL;
538 		*port = -1;
539 		return (-1);
540 	}
541 
542 	/*
543 	 * IPv6 addresses begin and end in brackets.  Set the port delimiter
544 	 * accordingly and search for it so we can do appropriate validation.
545 	 */
546 	if (socks5env[0] == '[')
547 		portDelim = "]:";
548 
549 	slen = strlen(socks5env);
550 	ext = strstr(socks5env, portDelim);
551 	if (socks5env[0] == '[') {
552 		if (socks5env[slen - 1] == ']') {
553 			*host = strndup(socks5env, slen);
554 		} else if (ext != NULL) {
555 			*host = strndup(socks5env, ext - socks5env + 1);
556 		} else {
557 			socks5_seterr(SOCKS5_ERR_BAD_PROXY_FORMAT);
558 			return (0);
559 		}
560 	} else {
561 		*host = strndup(socks5env, ext - socks5env);
562 	}
563 
564 	if (*host == NULL) {
565 		fprintf(stderr, "Failure to allocate memory, exiting.\n");
566 		return (-1);
567 	}
568 	if (ext == NULL) {
569 		*port = 1080; /* Default port as defined in RFC1928 */
570 	} else {
571 		ext += strlen(portDelim);
572 		errno = 0;
573 		*port = strtoimax(ext, (char **)&endptr, 10);
574 		if (*endptr != '\0' || errno != 0 || *port < 0 ||
575 		    *port > 65535) {
576 			free(*host);
577 			*host = NULL;
578 			socks5_seterr(SOCKS5_ERR_BAD_PORT);
579 			return (0);
580 		}
581 	}
582 
583 	return (2);
584 }
585 
586 
587 /*
588  * Establish a TCP connection to the specified port on the specified host.
589  */
590 conn_t *
591 fetch_connect(const char *host, int port, int af, int verbose)
592 {
593 	struct addrinfo *cais = NULL, *sais = NULL, *cai, *sai;
594 	const char *bindaddr;
595 	conn_t *conn = NULL;
596 	int err = 0, sd = -1;
597 	char *sockshost;
598 	int socksport;
599 
600 	DEBUGF("---> %s:%d\n", host, port);
601 
602 	/*
603 	 * Check if SOCKS5_PROXY env variable is set.  fetch_socks5_getenv
604 	 * will either set sockshost = NULL or allocate memory in all cases.
605 	 */
606 	sockshost = NULL;
607 	if (!fetch_socks5_getenv(&sockshost, &socksport))
608 		goto fail;
609 
610 	/* Not using SOCKS5 proxy */
611 	if (sockshost == NULL) {
612 		/* resolve server address */
613 		if (verbose)
614 			fetch_info("resolving server address: %s:%d", host,
615 			    port);
616 		if ((sais = fetch_resolve(host, port, af)) == NULL)
617 			goto fail;
618 
619 		/* resolve client address */
620 		bindaddr = getenv("FETCH_BIND_ADDRESS");
621 		if (bindaddr != NULL && *bindaddr != '\0') {
622 			if (verbose)
623 				fetch_info("resolving client address: %s",
624 				    bindaddr);
625 			if ((cais = fetch_resolve(bindaddr, 0, af)) == NULL)
626 				goto fail;
627 		}
628 	} else {
629 		/* resolve socks5 proxy address */
630 		if (verbose)
631 			fetch_info("resolving SOCKS5 server address: %s:%d",
632 			    sockshost, socksport);
633 		if ((sais = fetch_resolve(sockshost, socksport, af)) == NULL) {
634 			socks5_seterr(SOCKS5_ERR_BAD_HOST);
635 			goto fail;
636 		}
637 	}
638 
639 	/* try each server address in turn */
640 	for (err = 0, sai = sais; sai != NULL; sai = sai->ai_next) {
641 		/* open socket */
642 		if ((sd = socket(sai->ai_family, SOCK_STREAM, 0)) < 0)
643 			goto syserr;
644 		/* attempt to bind to client address */
645 		for (err = 0, cai = cais; cai != NULL; cai = cai->ai_next) {
646 			if (cai->ai_family != sai->ai_family)
647 				continue;
648 			if ((err = bind(sd, cai->ai_addr, cai->ai_addrlen)) == 0)
649 				break;
650 		}
651 		if (err != 0) {
652 			if (verbose)
653 				fetch_info("failed to bind to %s", bindaddr);
654 			goto syserr;
655 		}
656 		/* attempt to connect to server address */
657 		if ((err = connect(sd, sai->ai_addr, sai->ai_addrlen)) == 0)
658 			break;
659 		/* clean up before next attempt */
660 		close(sd);
661 		sd = -1;
662 	}
663 	if (err != 0) {
664 		if (verbose && sockshost == NULL) {
665 			fetch_info("failed to connect to %s:%d", host, port);
666 			goto syserr;
667 		} else if (sockshost != NULL) {
668 			if (verbose)
669 				fetch_info(
670 				    "failed to connect to SOCKS5 server %s:%d",
671 				    sockshost, socksport);
672 			socks5_seterr(SOCKS5_ERR_CONN_REFUSED);
673 			goto fail;
674 		}
675 		goto syserr;
676 	}
677 
678 	if ((conn = fetch_reopen(sd)) == NULL)
679 		goto syserr;
680 
681 	if (sockshost)
682 		if (!fetch_socks5_init(conn, host, port, verbose))
683 			goto fail;
684 	free(sockshost);
685 	if (cais != NULL)
686 		freeaddrinfo(cais);
687 	if (sais != NULL)
688 		freeaddrinfo(sais);
689 	return (conn);
690 syserr:
691 	fetch_syserr();
692 fail:
693 	free(sockshost);
694 	/* Fully close if it was opened; otherwise just don't leak the fd. */
695 	if (conn != NULL)
696 		fetch_close(conn);
697 	else if (sd >= 0)
698 		close(sd);
699 	if (cais != NULL)
700 		freeaddrinfo(cais);
701 	if (sais != NULL)
702 		freeaddrinfo(sais);
703 	return (NULL);
704 }
705 
706 #ifdef WITH_SSL
707 /*
708  * Convert characters A-Z to lowercase (intentionally avoid any locale
709  * specific conversions).
710  */
711 static char
712 fetch_ssl_tolower(char in)
713 {
714 	if (in >= 'A' && in <= 'Z')
715 		return (in + 32);
716 	else
717 		return (in);
718 }
719 
720 /*
721  * isalpha implementation that intentionally avoids any locale specific
722  * conversions.
723  */
724 static int
725 fetch_ssl_isalpha(char in)
726 {
727 	return ((in >= 'A' && in <= 'Z') || (in >= 'a' && in <= 'z'));
728 }
729 
730 /*
731  * Check if passed hostnames a and b are equal.
732  */
733 static int
734 fetch_ssl_hname_equal(const char *a, size_t alen, const char *b,
735     size_t blen)
736 {
737 	size_t i;
738 
739 	if (alen != blen)
740 		return (0);
741 	for (i = 0; i < alen; ++i) {
742 		if (fetch_ssl_tolower(a[i]) != fetch_ssl_tolower(b[i]))
743 			return (0);
744 	}
745 	return (1);
746 }
747 
748 /*
749  * Check if domain label is traditional, meaning that only A-Z, a-z, 0-9
750  * and '-' (hyphen) are allowed. Hyphens have to be surrounded by alpha-
751  * numeric characters. Double hyphens (like they're found in IDN a-labels
752  * 'xn--') are not allowed. Empty labels are invalid.
753  */
754 static int
755 fetch_ssl_is_trad_domain_label(const char *l, size_t len, int wcok)
756 {
757 	size_t i;
758 
759 	if (!len || l[0] == '-' || l[len-1] == '-')
760 		return (0);
761 	for (i = 0; i < len; ++i) {
762 		if (!isdigit(l[i]) &&
763 		    !fetch_ssl_isalpha(l[i]) &&
764 		    !(l[i] == '*' && wcok) &&
765 		    !(l[i] == '-' && l[i - 1] != '-'))
766 			return (0);
767 	}
768 	return (1);
769 }
770 
771 /*
772  * Check if host name consists only of numbers. This might indicate an IP
773  * address, which is not a good idea for CN wildcard comparison.
774  */
775 static int
776 fetch_ssl_hname_is_only_numbers(const char *hostname, size_t len)
777 {
778 	size_t i;
779 
780 	for (i = 0; i < len; ++i) {
781 		if (!((hostname[i] >= '0' && hostname[i] <= '9') ||
782 		    hostname[i] == '.'))
783 			return (0);
784 	}
785 	return (1);
786 }
787 
788 /*
789  * Check if the host name h passed matches the pattern passed in m which
790  * is usually part of subjectAltName or CN of a certificate presented to
791  * the client. This includes wildcard matching. The algorithm is based on
792  * RFC6125, sections 6.4.3 and 7.2, which clarifies RFC2818 and RFC3280.
793  */
794 static int
795 fetch_ssl_hname_match(const char *h, size_t hlen, const char *m,
796     size_t mlen)
797 {
798 	int delta, hdotidx, mdot1idx, wcidx;
799 	const char *hdot, *mdot1, *mdot2;
800 	const char *wc; /* wildcard */
801 
802 	if (!(h && *h && m && *m))
803 		return (0);
804 	if ((wc = strnstr(m, "*", mlen)) == NULL)
805 		return (fetch_ssl_hname_equal(h, hlen, m, mlen));
806 	wcidx = wc - m;
807 	/* hostname should not be just dots and numbers */
808 	if (fetch_ssl_hname_is_only_numbers(h, hlen))
809 		return (0);
810 	/* only one wildcard allowed in pattern */
811 	if (strnstr(wc + 1, "*", mlen - wcidx - 1) != NULL)
812 		return (0);
813 	/*
814 	 * there must be at least two more domain labels and
815 	 * wildcard has to be in the leftmost label (RFC6125)
816 	 */
817 	mdot1 = strnstr(m, ".", mlen);
818 	if (mdot1 == NULL || mdot1 < wc || (mlen - (mdot1 - m)) < 4)
819 		return (0);
820 	mdot1idx = mdot1 - m;
821 	mdot2 = strnstr(mdot1 + 1, ".", mlen - mdot1idx - 1);
822 	if (mdot2 == NULL || (mlen - (mdot2 - m)) < 2)
823 		return (0);
824 	/* hostname must contain a dot and not be the 1st char */
825 	hdot = strnstr(h, ".", hlen);
826 	if (hdot == NULL || hdot == h)
827 		return (0);
828 	hdotidx = hdot - h;
829 	/*
830 	 * host part of hostname must be at least as long as
831 	 * pattern it's supposed to match
832 	 */
833 	if (hdotidx < mdot1idx)
834 		return (0);
835 	/*
836 	 * don't allow wildcards in non-traditional domain names
837 	 * (IDN, A-label, U-label...)
838 	 */
839 	if (!fetch_ssl_is_trad_domain_label(h, hdotidx, 0) ||
840 	    !fetch_ssl_is_trad_domain_label(m, mdot1idx, 1))
841 		return (0);
842 	/* match domain part (part after first dot) */
843 	if (!fetch_ssl_hname_equal(hdot, hlen - hdotidx, mdot1,
844 	    mlen - mdot1idx))
845 		return (0);
846 	/* match part left of wildcard */
847 	if (!fetch_ssl_hname_equal(h, wcidx, m, wcidx))
848 		return (0);
849 	/* match part right of wildcard */
850 	delta = mdot1idx - wcidx - 1;
851 	if (!fetch_ssl_hname_equal(hdot - delta, delta,
852 	    mdot1 - delta, delta))
853 		return (0);
854 	/* all tests succeeded, it's a match */
855 	return (1);
856 }
857 
858 /*
859  * Get numeric host address info - returns NULL if host was not an IP
860  * address. The caller is responsible for deallocation using
861  * freeaddrinfo(3).
862  */
863 static struct addrinfo *
864 fetch_ssl_get_numeric_addrinfo(const char *hostname, size_t len)
865 {
866 	struct addrinfo hints, *res;
867 	char *host;
868 
869 	host = (char *)malloc(len + 1);
870 	memcpy(host, hostname, len);
871 	host[len] = '\0';
872 	memset(&hints, 0, sizeof(hints));
873 	hints.ai_family = PF_UNSPEC;
874 	hints.ai_socktype = SOCK_STREAM;
875 	hints.ai_protocol = 0;
876 	hints.ai_flags = AI_NUMERICHOST;
877 	/* port is not relevant for this purpose */
878 	if (getaddrinfo(host, "443", &hints, &res) != 0)
879 		res = NULL;
880 	free(host);
881 	return res;
882 }
883 
884 /*
885  * Compare ip address in addrinfo with address passes.
886  */
887 static int
888 fetch_ssl_ipaddr_match_bin(const struct addrinfo *lhost, const char *rhost,
889     size_t rhostlen)
890 {
891 	const void *left;
892 
893 	if (lhost->ai_family == AF_INET && rhostlen == 4) {
894 		left = (void *)&((struct sockaddr_in*)(void *)
895 		    lhost->ai_addr)->sin_addr.s_addr;
896 #ifdef INET6
897 	} else if (lhost->ai_family == AF_INET6 && rhostlen == 16) {
898 		left = (void *)&((struct sockaddr_in6 *)(void *)
899 		    lhost->ai_addr)->sin6_addr;
900 #endif
901 	} else
902 		return (0);
903 	return (!memcmp(left, (const void *)rhost, rhostlen) ? 1 : 0);
904 }
905 
906 /*
907  * Compare ip address in addrinfo with host passed. If host is not an IP
908  * address, comparison will fail.
909  */
910 static int
911 fetch_ssl_ipaddr_match(const struct addrinfo *laddr, const char *r,
912     size_t rlen)
913 {
914 	struct addrinfo *raddr;
915 	int ret;
916 	char *rip;
917 
918 	ret = 0;
919 	if ((raddr = fetch_ssl_get_numeric_addrinfo(r, rlen)) == NULL)
920 		return 0; /* not a numeric host */
921 
922 	if (laddr->ai_family == raddr->ai_family) {
923 		if (laddr->ai_family == AF_INET) {
924 			rip = (char *)&((struct sockaddr_in *)(void *)
925 			    raddr->ai_addr)->sin_addr.s_addr;
926 			ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 4);
927 #ifdef INET6
928 		} else if (laddr->ai_family == AF_INET6) {
929 			rip = (char *)&((struct sockaddr_in6 *)(void *)
930 			    raddr->ai_addr)->sin6_addr;
931 			ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 16);
932 #endif
933 		}
934 
935 	}
936 	freeaddrinfo(raddr);
937 	return (ret);
938 }
939 
940 /*
941  * Verify server certificate by subjectAltName.
942  */
943 static int
944 fetch_ssl_verify_altname(STACK_OF(GENERAL_NAME) *altnames,
945     const char *host, struct addrinfo *ip)
946 {
947 	const GENERAL_NAME *name;
948 	size_t nslen;
949 	int i;
950 	const char *ns;
951 
952 	for (i = 0; i < sk_GENERAL_NAME_num(altnames); ++i) {
953 		name = sk_GENERAL_NAME_value(altnames, i);
954 		ns = (const char *)ASN1_STRING_get0_data(name->d.ia5);
955 		nslen = (size_t)ASN1_STRING_length(name->d.ia5);
956 
957 		if (name->type == GEN_DNS && ip == NULL &&
958 		    fetch_ssl_hname_match(host, strlen(host), ns, nslen))
959 			return (1);
960 		else if (name->type == GEN_IPADD && ip != NULL &&
961 		    fetch_ssl_ipaddr_match_bin(ip, ns, nslen))
962 			return (1);
963 	}
964 	return (0);
965 }
966 
967 /*
968  * Verify server certificate by CN.
969  */
970 static int
971 fetch_ssl_verify_cn(X509_NAME *subject, const char *host,
972     struct addrinfo *ip)
973 {
974 	ASN1_STRING *namedata;
975 	X509_NAME_ENTRY *nameentry;
976 	int cnlen, lastpos, loc, ret;
977 	unsigned char *cn;
978 
979 	ret = 0;
980 	lastpos = -1;
981 	loc = -1;
982 	cn = NULL;
983 	/* get most specific CN (last entry in list) and compare */
984 	while ((lastpos = X509_NAME_get_index_by_NID(subject,
985 	    NID_commonName, lastpos)) != -1)
986 		loc = lastpos;
987 
988 	if (loc > -1) {
989 		nameentry = X509_NAME_get_entry(subject, loc);
990 		namedata = X509_NAME_ENTRY_get_data(nameentry);
991 		cnlen = ASN1_STRING_to_UTF8(&cn, namedata);
992 		if (ip == NULL &&
993 		    fetch_ssl_hname_match(host, strlen(host), cn, cnlen))
994 			ret = 1;
995 		else if (ip != NULL && fetch_ssl_ipaddr_match(ip, cn, cnlen))
996 			ret = 1;
997 		OPENSSL_free(cn);
998 	}
999 	return (ret);
1000 }
1001 
1002 /*
1003  * Verify that server certificate subjectAltName/CN matches
1004  * hostname. First check, if there are alternative subject names. If yes,
1005  * those have to match. Only if those don't exist it falls back to
1006  * checking the subject's CN.
1007  */
1008 static int
1009 fetch_ssl_verify_hname(X509 *cert, const char *host)
1010 {
1011 	struct addrinfo *ip;
1012 	STACK_OF(GENERAL_NAME) *altnames;
1013 	X509_NAME *subject;
1014 	int ret;
1015 
1016 	ret = 0;
1017 	ip = fetch_ssl_get_numeric_addrinfo(host, strlen(host));
1018 	altnames = X509_get_ext_d2i(cert, NID_subject_alt_name,
1019 	    NULL, NULL);
1020 
1021 	if (altnames != NULL) {
1022 		ret = fetch_ssl_verify_altname(altnames, host, ip);
1023 	} else {
1024 		subject = X509_get_subject_name(cert);
1025 		if (subject != NULL)
1026 			ret = fetch_ssl_verify_cn(subject, host, ip);
1027 	}
1028 
1029 	if (ip != NULL)
1030 		freeaddrinfo(ip);
1031 	if (altnames != NULL)
1032 		GENERAL_NAMES_free(altnames);
1033 	return (ret);
1034 }
1035 
1036 /*
1037  * Configure transport security layer based on environment.
1038  */
1039 static void
1040 fetch_ssl_setup_transport_layer(SSL_CTX *ctx, int verbose)
1041 {
1042 	long ssl_ctx_options;
1043 
1044 	ssl_ctx_options = SSL_OP_ALL | SSL_OP_NO_SSLv3 | SSL_OP_NO_TICKET;
1045 	if (getenv("SSL_NO_TLS1") != NULL)
1046 		ssl_ctx_options |= SSL_OP_NO_TLSv1;
1047 	if (getenv("SSL_NO_TLS1_1") != NULL)
1048 		ssl_ctx_options |= SSL_OP_NO_TLSv1_1;
1049 	if (getenv("SSL_NO_TLS1_2") != NULL)
1050 		ssl_ctx_options |= SSL_OP_NO_TLSv1_2;
1051 	if (verbose)
1052 		fetch_info("SSL options: %lx", ssl_ctx_options);
1053 	SSL_CTX_set_options(ctx, ssl_ctx_options);
1054 }
1055 
1056 
1057 /*
1058  * Configure peer verification based on environment.
1059  */
1060 #define LOCAL_CERT_FILE	_PATH_LOCALBASE "/etc/ssl/cert.pem"
1061 #define BASE_CERT_FILE	"/etc/ssl/cert.pem"
1062 static int
1063 fetch_ssl_setup_peer_verification(SSL_CTX *ctx, int verbose)
1064 {
1065 	X509_LOOKUP *crl_lookup;
1066 	X509_STORE *crl_store;
1067 	const char *ca_cert_file, *ca_cert_path, *crl_file;
1068 
1069 	if (getenv("SSL_NO_VERIFY_PEER") == NULL) {
1070 		ca_cert_file = getenv("SSL_CA_CERT_FILE");
1071 		if (ca_cert_file == NULL &&
1072 		    access(LOCAL_CERT_FILE, R_OK) == 0)
1073 			ca_cert_file = LOCAL_CERT_FILE;
1074 		if (ca_cert_file == NULL &&
1075 		    access(BASE_CERT_FILE, R_OK) == 0)
1076 			ca_cert_file = BASE_CERT_FILE;
1077 		ca_cert_path = getenv("SSL_CA_CERT_PATH");
1078 		if (verbose) {
1079 			fetch_info("Peer verification enabled");
1080 			if (ca_cert_file != NULL)
1081 				fetch_info("Using CA cert file: %s",
1082 				    ca_cert_file);
1083 			if (ca_cert_path != NULL)
1084 				fetch_info("Using CA cert path: %s",
1085 				    ca_cert_path);
1086 			if (ca_cert_file == NULL && ca_cert_path == NULL)
1087 				fetch_info("Using OpenSSL default "
1088 				    "CA cert file and path");
1089 		}
1090 		SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER,
1091 		    fetch_ssl_cb_verify_crt);
1092 		if (ca_cert_file != NULL || ca_cert_path != NULL)
1093 			SSL_CTX_load_verify_locations(ctx, ca_cert_file,
1094 			    ca_cert_path);
1095 		else
1096 			SSL_CTX_set_default_verify_paths(ctx);
1097 		if ((crl_file = getenv("SSL_CRL_FILE")) != NULL) {
1098 			if (verbose)
1099 				fetch_info("Using CRL file: %s", crl_file);
1100 			crl_store = SSL_CTX_get_cert_store(ctx);
1101 			crl_lookup = X509_STORE_add_lookup(crl_store,
1102 			    X509_LOOKUP_file());
1103 			if (crl_lookup == NULL ||
1104 			    !X509_load_crl_file(crl_lookup, crl_file,
1105 				X509_FILETYPE_PEM)) {
1106 				fprintf(stderr,
1107 				    "Could not load CRL file %s\n",
1108 				    crl_file);
1109 				return (0);
1110 			}
1111 			X509_STORE_set_flags(crl_store,
1112 			    X509_V_FLAG_CRL_CHECK |
1113 			    X509_V_FLAG_CRL_CHECK_ALL);
1114 		}
1115 	}
1116 	return (1);
1117 }
1118 
1119 /*
1120  * Configure client certificate based on environment.
1121  */
1122 static int
1123 fetch_ssl_setup_client_certificate(SSL_CTX *ctx, int verbose)
1124 {
1125 	const char *client_cert_file, *client_key_file;
1126 
1127 	if ((client_cert_file = getenv("SSL_CLIENT_CERT_FILE")) != NULL) {
1128 		client_key_file = getenv("SSL_CLIENT_KEY_FILE") != NULL ?
1129 		    getenv("SSL_CLIENT_KEY_FILE") : client_cert_file;
1130 		if (verbose) {
1131 			fetch_info("Using client cert file: %s",
1132 			    client_cert_file);
1133 			fetch_info("Using client key file: %s",
1134 			    client_key_file);
1135 		}
1136 		if (SSL_CTX_use_certificate_chain_file(ctx,
1137 			client_cert_file) != 1) {
1138 			fprintf(stderr,
1139 			    "Could not load client certificate %s\n",
1140 			    client_cert_file);
1141 			return (0);
1142 		}
1143 		if (SSL_CTX_use_PrivateKey_file(ctx, client_key_file,
1144 			SSL_FILETYPE_PEM) != 1) {
1145 			fprintf(stderr,
1146 			    "Could not load client key %s\n",
1147 			    client_key_file);
1148 			return (0);
1149 		}
1150 	}
1151 	return (1);
1152 }
1153 
1154 /*
1155  * Callback for SSL certificate verification, this is called on server
1156  * cert verification. It takes no decision, but informs the user in case
1157  * verification failed.
1158  */
1159 int
1160 fetch_ssl_cb_verify_crt(int verified, X509_STORE_CTX *ctx)
1161 {
1162 	X509 *crt;
1163 	X509_NAME *name;
1164 	char *str;
1165 
1166 	str = NULL;
1167 	if (!verified) {
1168 		if ((crt = X509_STORE_CTX_get_current_cert(ctx)) != NULL &&
1169 		    (name = X509_get_subject_name(crt)) != NULL)
1170 			str = X509_NAME_oneline(name, 0, 0);
1171 		fprintf(stderr, "Certificate verification failed for %s\n",
1172 		    str != NULL ? str : "no relevant certificate");
1173 		OPENSSL_free(str);
1174 	}
1175 	return (verified);
1176 }
1177 
1178 #endif
1179 
1180 /*
1181  * Enable SSL on a connection.
1182  */
1183 int
1184 fetch_ssl(conn_t *conn, const struct url *URL, int verbose)
1185 {
1186 #ifdef WITH_SSL
1187 	int ret, ssl_err;
1188 	X509_NAME *name;
1189 	char *str;
1190 
1191 	conn->ssl_meth = SSLv23_client_method();
1192 	conn->ssl_ctx = SSL_CTX_new(conn->ssl_meth);
1193 	SSL_CTX_set_mode(conn->ssl_ctx, SSL_MODE_AUTO_RETRY);
1194 
1195 	fetch_ssl_setup_transport_layer(conn->ssl_ctx, verbose);
1196 	if (!fetch_ssl_setup_peer_verification(conn->ssl_ctx, verbose))
1197 		return (-1);
1198 	if (!fetch_ssl_setup_client_certificate(conn->ssl_ctx, verbose))
1199 		return (-1);
1200 
1201 	conn->ssl = SSL_new(conn->ssl_ctx);
1202 	if (conn->ssl == NULL) {
1203 		fprintf(stderr, "SSL context creation failed\n");
1204 		return (-1);
1205 	}
1206 	SSL_set_fd(conn->ssl, conn->sd);
1207 
1208 #if !defined(OPENSSL_NO_TLSEXT)
1209 	if (!SSL_set_tlsext_host_name(conn->ssl,
1210 	    __DECONST(struct url *, URL)->host)) {
1211 		fprintf(stderr,
1212 		    "TLS server name indication extension failed for host %s\n",
1213 		    URL->host);
1214 		return (-1);
1215 	}
1216 #endif
1217 	while ((ret = SSL_connect(conn->ssl)) == -1) {
1218 		ssl_err = SSL_get_error(conn->ssl, ret);
1219 		if (ssl_err != SSL_ERROR_WANT_READ &&
1220 		    ssl_err != SSL_ERROR_WANT_WRITE) {
1221 			ERR_print_errors_fp(stderr);
1222 			return (-1);
1223 		}
1224 	}
1225 	conn->ssl_cert = SSL_get_peer_certificate(conn->ssl);
1226 
1227 	if (conn->ssl_cert == NULL) {
1228 		fprintf(stderr, "No server SSL certificate\n");
1229 		return (-1);
1230 	}
1231 
1232 	if (getenv("SSL_NO_VERIFY_HOSTNAME") == NULL) {
1233 		if (verbose)
1234 			fetch_info("Verify hostname");
1235 		if (!fetch_ssl_verify_hname(conn->ssl_cert, URL->host)) {
1236 			fprintf(stderr,
1237 			    "SSL certificate subject doesn't match host %s\n",
1238 			    URL->host);
1239 			return (-1);
1240 		}
1241 	}
1242 
1243 	if (verbose) {
1244 		fetch_info("%s connection established using %s",
1245 		    SSL_get_version(conn->ssl), SSL_get_cipher(conn->ssl));
1246 		name = X509_get_subject_name(conn->ssl_cert);
1247 		str = X509_NAME_oneline(name, 0, 0);
1248 		fetch_info("Certificate subject: %s", str);
1249 		OPENSSL_free(str);
1250 		name = X509_get_issuer_name(conn->ssl_cert);
1251 		str = X509_NAME_oneline(name, 0, 0);
1252 		fetch_info("Certificate issuer: %s", str);
1253 		OPENSSL_free(str);
1254 	}
1255 
1256 	return (0);
1257 #else
1258 	(void)conn;
1259 	(void)verbose;
1260 	(void)URL;
1261 	fprintf(stderr, "SSL support disabled\n");
1262 	return (-1);
1263 #endif
1264 }
1265 
1266 #define FETCH_READ_WAIT		-2
1267 #define FETCH_READ_ERROR	-1
1268 #define FETCH_READ_DONE		 0
1269 
1270 #ifdef WITH_SSL
1271 static ssize_t
1272 fetch_ssl_read(SSL *ssl, char *buf, size_t len)
1273 {
1274 	ssize_t rlen;
1275 	int ssl_err;
1276 
1277 	rlen = SSL_read(ssl, buf, len);
1278 	if (rlen < 0) {
1279 		ssl_err = SSL_get_error(ssl, rlen);
1280 		if (ssl_err == SSL_ERROR_WANT_READ ||
1281 		    ssl_err == SSL_ERROR_WANT_WRITE) {
1282 			return (FETCH_READ_WAIT);
1283 		} else {
1284 			ERR_print_errors_fp(stderr);
1285 			return (FETCH_READ_ERROR);
1286 		}
1287 	}
1288 	return (rlen);
1289 }
1290 #endif
1291 
1292 static ssize_t
1293 fetch_socket_read(int sd, char *buf, size_t len)
1294 {
1295 	ssize_t rlen;
1296 
1297 	rlen = read(sd, buf, len);
1298 	if (rlen < 0) {
1299 		if (errno == EAGAIN || (errno == EINTR && fetchRestartCalls))
1300 			return (FETCH_READ_WAIT);
1301 		else
1302 			return (FETCH_READ_ERROR);
1303 	}
1304 	return (rlen);
1305 }
1306 
1307 /*
1308  * Read a character from a connection w/ timeout
1309  */
1310 ssize_t
1311 fetch_read(conn_t *conn, char *buf, size_t len)
1312 {
1313 	struct timeval now, timeout, delta;
1314 	struct pollfd pfd;
1315 	ssize_t rlen;
1316 	int deltams;
1317 
1318 	if (fetchTimeout > 0) {
1319 		gettimeofday(&timeout, NULL);
1320 		timeout.tv_sec += fetchTimeout;
1321 	}
1322 
1323 	deltams = INFTIM;
1324 	memset(&pfd, 0, sizeof pfd);
1325 	pfd.fd = conn->sd;
1326 	pfd.events = POLLIN | POLLERR;
1327 
1328 	for (;;) {
1329 		/*
1330 		 * The socket is non-blocking.  Instead of the canonical
1331 		 * poll() -> read(), we do the following:
1332 		 *
1333 		 * 1) call read() or SSL_read().
1334 		 * 2) if we received some data, return it.
1335 		 * 3) if an error occurred, return -1.
1336 		 * 4) if read() or SSL_read() signaled EOF, return.
1337 		 * 5) if we did not receive any data but we're not at EOF,
1338 		 *    call poll().
1339 		 *
1340 		 * In the SSL case, this is necessary because if we
1341 		 * receive a close notification, we have to call
1342 		 * SSL_read() one additional time after we've read
1343 		 * everything we received.
1344 		 *
1345 		 * In the non-SSL case, it may improve performance (very
1346 		 * slightly) when reading small amounts of data.
1347 		 */
1348 #ifdef WITH_SSL
1349 		if (conn->ssl != NULL)
1350 			rlen = fetch_ssl_read(conn->ssl, buf, len);
1351 		else
1352 #endif
1353 			rlen = fetch_socket_read(conn->sd, buf, len);
1354 		if (rlen >= 0) {
1355 			break;
1356 		} else if (rlen == FETCH_READ_ERROR) {
1357 			fetch_syserr();
1358 			return (-1);
1359 		}
1360 		// assert(rlen == FETCH_READ_WAIT);
1361 		if (fetchTimeout > 0) {
1362 			gettimeofday(&now, NULL);
1363 			if (!timercmp(&timeout, &now, >)) {
1364 				errno = ETIMEDOUT;
1365 				fetch_syserr();
1366 				return (-1);
1367 			}
1368 			timersub(&timeout, &now, &delta);
1369 			deltams = delta.tv_sec * 1000 +
1370 			    delta.tv_usec / 1000;;
1371 		}
1372 		errno = 0;
1373 		pfd.revents = 0;
1374 		if (poll(&pfd, 1, deltams) < 0) {
1375 			if (errno == EINTR && fetchRestartCalls)
1376 				continue;
1377 			fetch_syserr();
1378 			return (-1);
1379 		}
1380 	}
1381 	return (rlen);
1382 }
1383 
1384 
1385 /*
1386  * Read a line of text from a connection w/ timeout
1387  */
1388 #define MIN_BUF_SIZE 1024
1389 
1390 int
1391 fetch_getln(conn_t *conn)
1392 {
1393 	char *tmp;
1394 	size_t tmpsize;
1395 	ssize_t len;
1396 	char c;
1397 
1398 	if (conn->buf == NULL) {
1399 		if ((conn->buf = malloc(MIN_BUF_SIZE)) == NULL) {
1400 			errno = ENOMEM;
1401 			return (-1);
1402 		}
1403 		conn->bufsize = MIN_BUF_SIZE;
1404 	}
1405 
1406 	conn->buf[0] = '\0';
1407 	conn->buflen = 0;
1408 
1409 	do {
1410 		len = fetch_read(conn, &c, 1);
1411 		if (len == -1)
1412 			return (-1);
1413 		if (len == 0)
1414 			break;
1415 		conn->buf[conn->buflen++] = c;
1416 		if (conn->buflen == conn->bufsize) {
1417 			tmp = conn->buf;
1418 			tmpsize = conn->bufsize * 2 + 1;
1419 			if ((tmp = realloc(tmp, tmpsize)) == NULL) {
1420 				errno = ENOMEM;
1421 				return (-1);
1422 			}
1423 			conn->buf = tmp;
1424 			conn->bufsize = tmpsize;
1425 		}
1426 	} while (c != '\n');
1427 
1428 	conn->buf[conn->buflen] = '\0';
1429 	DEBUGF("<<< %s", conn->buf);
1430 	return (0);
1431 }
1432 
1433 
1434 /*
1435  * Write to a connection w/ timeout
1436  */
1437 ssize_t
1438 fetch_write(conn_t *conn, const char *buf, size_t len)
1439 {
1440 	struct iovec iov;
1441 
1442 	iov.iov_base = __DECONST(char *, buf);
1443 	iov.iov_len = len;
1444 	return fetch_writev(conn, &iov, 1);
1445 }
1446 
1447 /*
1448  * Write a vector to a connection w/ timeout
1449  * Note: can modify the iovec.
1450  */
1451 ssize_t
1452 fetch_writev(conn_t *conn, struct iovec *iov, int iovcnt)
1453 {
1454 	struct timeval now, timeout, delta;
1455 	struct pollfd pfd;
1456 	ssize_t wlen, total;
1457 	int deltams;
1458 
1459 	memset(&pfd, 0, sizeof pfd);
1460 	if (fetchTimeout) {
1461 		pfd.fd = conn->sd;
1462 		pfd.events = POLLOUT | POLLERR;
1463 		gettimeofday(&timeout, NULL);
1464 		timeout.tv_sec += fetchTimeout;
1465 	}
1466 
1467 	total = 0;
1468 	while (iovcnt > 0) {
1469 		while (fetchTimeout && pfd.revents == 0) {
1470 			gettimeofday(&now, NULL);
1471 			if (!timercmp(&timeout, &now, >)) {
1472 				errno = ETIMEDOUT;
1473 				fetch_syserr();
1474 				return (-1);
1475 			}
1476 			timersub(&timeout, &now, &delta);
1477 			deltams = delta.tv_sec * 1000 +
1478 			    delta.tv_usec / 1000;
1479 			errno = 0;
1480 			pfd.revents = 0;
1481 			if (poll(&pfd, 1, deltams) < 0) {
1482 				/* POSIX compliance */
1483 				if (errno == EAGAIN)
1484 					continue;
1485 				if (errno == EINTR && fetchRestartCalls)
1486 					continue;
1487 				return (-1);
1488 			}
1489 		}
1490 		errno = 0;
1491 #ifdef WITH_SSL
1492 		if (conn->ssl != NULL)
1493 			wlen = SSL_write(conn->ssl,
1494 			    iov->iov_base, iov->iov_len);
1495 		else
1496 #endif
1497 			wlen = writev(conn->sd, iov, iovcnt);
1498 		if (wlen == 0) {
1499 			/* we consider a short write a failure */
1500 			/* XXX perhaps we shouldn't in the SSL case */
1501 			errno = EPIPE;
1502 			fetch_syserr();
1503 			return (-1);
1504 		}
1505 		if (wlen < 0) {
1506 			if (errno == EINTR && fetchRestartCalls)
1507 				continue;
1508 			return (-1);
1509 		}
1510 		total += wlen;
1511 		while (iovcnt > 0 && wlen >= (ssize_t)iov->iov_len) {
1512 			wlen -= iov->iov_len;
1513 			iov++;
1514 			iovcnt--;
1515 		}
1516 		if (iovcnt > 0) {
1517 			iov->iov_len -= wlen;
1518 			iov->iov_base = __DECONST(char *, iov->iov_base) + wlen;
1519 		}
1520 	}
1521 	return (total);
1522 }
1523 
1524 
1525 /*
1526  * Write a line of text to a connection w/ timeout
1527  */
1528 int
1529 fetch_putln(conn_t *conn, const char *str, size_t len)
1530 {
1531 	struct iovec iov[2];
1532 	int ret;
1533 
1534 	DEBUGF(">>> %s\n", str);
1535 	iov[0].iov_base = __DECONST(char *, str);
1536 	iov[0].iov_len = len;
1537 	iov[1].iov_base = __DECONST(char *, ENDL);
1538 	iov[1].iov_len = sizeof(ENDL);
1539 	if (len == 0)
1540 		ret = fetch_writev(conn, &iov[1], 1);
1541 	else
1542 		ret = fetch_writev(conn, iov, 2);
1543 	if (ret == -1)
1544 		return (-1);
1545 	return (0);
1546 }
1547 
1548 
1549 /*
1550  * Close connection
1551  */
1552 int
1553 fetch_close(conn_t *conn)
1554 {
1555 	int ret;
1556 
1557 	if (--conn->ref > 0)
1558 		return (0);
1559 #ifdef WITH_SSL
1560 	if (conn->ssl) {
1561 		SSL_shutdown(conn->ssl);
1562 		SSL_set_connect_state(conn->ssl);
1563 		SSL_free(conn->ssl);
1564 		conn->ssl = NULL;
1565 	}
1566 	if (conn->ssl_ctx) {
1567 		SSL_CTX_free(conn->ssl_ctx);
1568 		conn->ssl_ctx = NULL;
1569 	}
1570 	if (conn->ssl_cert) {
1571 		X509_free(conn->ssl_cert);
1572 		conn->ssl_cert = NULL;
1573 	}
1574 #endif
1575 	ret = close(conn->sd);
1576 	free(conn->buf);
1577 	free(conn);
1578 	return (ret);
1579 }
1580 
1581 
1582 /*** Directory-related utility functions *************************************/
1583 
1584 int
1585 fetch_add_entry(struct url_ent **p, int *size, int *len,
1586     const char *name, struct url_stat *us)
1587 {
1588 	struct url_ent *tmp;
1589 
1590 	if (*p == NULL) {
1591 		*size = 0;
1592 		*len = 0;
1593 	}
1594 
1595 	if (*len >= *size - 1) {
1596 		tmp = reallocarray(*p, *size * 2 + 1, sizeof(**p));
1597 		if (tmp == NULL) {
1598 			errno = ENOMEM;
1599 			fetch_syserr();
1600 			return (-1);
1601 		}
1602 		*size = (*size * 2 + 1);
1603 		*p = tmp;
1604 	}
1605 
1606 	tmp = *p + *len;
1607 	snprintf(tmp->name, PATH_MAX, "%s", name);
1608 	memcpy(&tmp->stat, us, sizeof(*us));
1609 
1610 	(*len)++;
1611 	(++tmp)->name[0] = 0;
1612 
1613 	return (0);
1614 }
1615 
1616 
1617 /*** Authentication-related utility functions ********************************/
1618 
1619 static const char *
1620 fetch_read_word(FILE *f)
1621 {
1622 	static char word[1024];
1623 
1624 	if (fscanf(f, " %1023s ", word) != 1)
1625 		return (NULL);
1626 	return (word);
1627 }
1628 
1629 static int
1630 fetch_netrc_open(void)
1631 {
1632 	struct passwd *pwd;
1633 	char fn[PATH_MAX];
1634 	const char *p;
1635 	int fd, serrno;
1636 
1637 	if ((p = getenv("NETRC")) != NULL) {
1638 		DEBUGF("NETRC=%s\n", p);
1639 		if (snprintf(fn, sizeof(fn), "%s", p) >= (int)sizeof(fn)) {
1640 			fetch_info("$NETRC specifies a file name "
1641 			    "longer than PATH_MAX");
1642 			return (-1);
1643 		}
1644 	} else {
1645 		if ((p = getenv("HOME")) == NULL) {
1646 			if ((pwd = getpwuid(getuid())) == NULL ||
1647 			    (p = pwd->pw_dir) == NULL)
1648 				return (-1);
1649 		}
1650 		if (snprintf(fn, sizeof(fn), "%s/.netrc", p) >= (int)sizeof(fn))
1651 			return (-1);
1652 	}
1653 
1654 	if ((fd = open(fn, O_RDONLY)) < 0) {
1655 		serrno = errno;
1656 		DEBUGF("%s: %s\n", fn, strerror(serrno));
1657 		errno = serrno;
1658 	}
1659 	return (fd);
1660 }
1661 
1662 /*
1663  * Get authentication data for a URL from .netrc
1664  */
1665 int
1666 fetch_netrc_auth(struct url *url)
1667 {
1668 	const char *word;
1669 	int serrno;
1670 	FILE *f;
1671 
1672 	if (url->netrcfd < 0)
1673 		url->netrcfd = fetch_netrc_open();
1674 	if (url->netrcfd < 0)
1675 		return (-1);
1676 	if ((f = fdopen(url->netrcfd, "r")) == NULL) {
1677 		serrno = errno;
1678 		DEBUGF("fdopen(netrcfd): %s", strerror(errno));
1679 		close(url->netrcfd);
1680 		url->netrcfd = -1;
1681 		errno = serrno;
1682 		return (-1);
1683 	}
1684 	rewind(f);
1685 	DEBUGF("searching netrc for %s\n", url->host);
1686 	while ((word = fetch_read_word(f)) != NULL) {
1687 		if (strcmp(word, "default") == 0) {
1688 			DEBUGF("using default netrc settings\n");
1689 			break;
1690 		}
1691 		if (strcmp(word, "machine") == 0 &&
1692 		    (word = fetch_read_word(f)) != NULL &&
1693 		    strcasecmp(word, url->host) == 0) {
1694 			DEBUGF("using netrc settings for %s\n", word);
1695 			break;
1696 		}
1697 	}
1698 	if (word == NULL)
1699 		goto ferr;
1700 	while ((word = fetch_read_word(f)) != NULL) {
1701 		if (strcmp(word, "login") == 0) {
1702 			if ((word = fetch_read_word(f)) == NULL)
1703 				goto ferr;
1704 			if (snprintf(url->user, sizeof(url->user),
1705 				"%s", word) > (int)sizeof(url->user)) {
1706 				fetch_info("login name in .netrc is too long");
1707 				url->user[0] = '\0';
1708 			}
1709 		} else if (strcmp(word, "password") == 0) {
1710 			if ((word = fetch_read_word(f)) == NULL)
1711 				goto ferr;
1712 			if (snprintf(url->pwd, sizeof(url->pwd),
1713 				"%s", word) > (int)sizeof(url->pwd)) {
1714 				fetch_info("password in .netrc is too long");
1715 				url->pwd[0] = '\0';
1716 			}
1717 		} else if (strcmp(word, "account") == 0) {
1718 			if ((word = fetch_read_word(f)) == NULL)
1719 				goto ferr;
1720 			/* XXX not supported! */
1721 		} else {
1722 			break;
1723 		}
1724 	}
1725 	fclose(f);
1726 	url->netrcfd = -1;
1727 	return (0);
1728 ferr:
1729 	serrno = errno;
1730 	fclose(f);
1731 	url->netrcfd = -1;
1732 	errno = serrno;
1733 	return (-1);
1734 }
1735 
1736 /*
1737  * The no_proxy environment variable specifies a set of domains for
1738  * which the proxy should not be consulted; the contents is a comma-,
1739  * or space-separated list of domain names.  A single asterisk will
1740  * override all proxy variables and no transactions will be proxied
1741  * (for compatibility with lynx and curl, see the discussion at
1742  * <http://curl.haxx.se/mail/archive_pre_oct_99/0009.html>).
1743  */
1744 int
1745 fetch_no_proxy_match(const char *host)
1746 {
1747 	const char *no_proxy, *p, *q;
1748 	size_t h_len, d_len;
1749 
1750 	if ((no_proxy = getenv("NO_PROXY")) == NULL &&
1751 	    (no_proxy = getenv("no_proxy")) == NULL)
1752 		return (0);
1753 
1754 	/* asterisk matches any hostname */
1755 	if (strcmp(no_proxy, "*") == 0)
1756 		return (1);
1757 
1758 	h_len = strlen(host);
1759 	p = no_proxy;
1760 	do {
1761 		/* position p at the beginning of a domain suffix */
1762 		while (*p == ',' || isspace((unsigned char)*p))
1763 			p++;
1764 
1765 		/* position q at the first separator character */
1766 		for (q = p; *q; ++q)
1767 			if (*q == ',' || isspace((unsigned char)*q))
1768 				break;
1769 
1770 		d_len = q - p;
1771 		if (d_len > 0 && h_len >= d_len &&
1772 		    strncasecmp(host + h_len - d_len,
1773 			p, d_len) == 0) {
1774 			/* domain name matches */
1775 			return (1);
1776 		}
1777 
1778 		p = q + 1;
1779 	} while (*q);
1780 
1781 	return (0);
1782 }
1783