1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1998-2016 Dag-Erling Sm��rgrav
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 */
69static struct fetcherr netdb_errlist[] = {
70#ifdef EAI_NODATA
71	{ EAI_NODATA,	FETCH_RESOLV,	"Host not found" },
72#endif
73	{ EAI_AGAIN,	FETCH_TEMP,	"Transient resolver failure" },
74	{ EAI_FAIL,	FETCH_RESOLV,	"Non-recoverable resolver failure" },
75	{ EAI_NONAME,	FETCH_RESOLV,	"No address record" },
76	{ -1,		FETCH_UNKNOWN,	"Unknown resolver error" }
77};
78
79/*
80 * SOCKS5 error enumerations
81 */
82enum SOCKS5_ERR {
83/* Protocol errors */
84	SOCKS5_ERR_SELECTION,
85	SOCKS5_ERR_READ_METHOD,
86	SOCKS5_ERR_VER5_ONLY,
87	SOCKS5_ERR_NOMETHODS,
88	SOCKS5_ERR_NOTIMPLEMENTED,
89	SOCKS5_ERR_HOSTNAME_SIZE,
90	SOCKS5_ERR_REQUEST,
91	SOCKS5_ERR_REPLY,
92	SOCKS5_ERR_NON_VER5_RESP,
93	SOCKS5_ERR_GENERAL,
94	SOCKS5_ERR_NOT_ALLOWED,
95	SOCKS5_ERR_NET_UNREACHABLE,
96	SOCKS5_ERR_HOST_UNREACHABLE,
97	SOCKS5_ERR_CONN_REFUSED,
98	SOCKS5_ERR_TTL_EXPIRED,
99	SOCKS5_ERR_COM_UNSUPPORTED,
100	SOCKS5_ERR_ADDR_UNSUPPORTED,
101	SOCKS5_ERR_UNSPECIFIED,
102/* Configuration errors */
103	SOCKS5_ERR_BAD_HOST,
104	SOCKS5_ERR_BAD_PROXY_FORMAT,
105	SOCKS5_ERR_BAD_PORT
106};
107
108/*
109 * Error messages for SOCKS5 errors
110 */
111static struct fetcherr socks5_errlist[] = {
112/* SOCKS5 protocol errors */
113	{ SOCKS5_ERR_SELECTION,		FETCH_ABORT,	"SOCKS5: Failed to send selection method" },
114	{ SOCKS5_ERR_READ_METHOD,	FETCH_ABORT,	"SOCKS5: Failed to read method" },
115	{ SOCKS5_ERR_VER5_ONLY,		FETCH_PROTO,	"SOCKS5: Only version 5 is implemented" },
116	{ SOCKS5_ERR_NOMETHODS,		FETCH_PROTO,	"SOCKS5: No acceptable methods" },
117	{ SOCKS5_ERR_NOTIMPLEMENTED,	FETCH_PROTO,	"SOCKS5: Method currently not implemented" },
118	{ SOCKS5_ERR_HOSTNAME_SIZE,	FETCH_PROTO,	"SOCKS5: Hostname size is above 256 bytes" },
119	{ SOCKS5_ERR_REQUEST,		FETCH_PROTO,	"SOCKS5: Failed to request" },
120	{ SOCKS5_ERR_REPLY,		FETCH_PROTO,	"SOCKS5: Failed to receive reply" },
121	{ SOCKS5_ERR_NON_VER5_RESP,	FETCH_PROTO,	"SOCKS5: Server responded with a non-version 5 response" },
122	{ SOCKS5_ERR_GENERAL,		FETCH_ABORT,	"SOCKS5: General server failure" },
123	{ SOCKS5_ERR_NOT_ALLOWED,	FETCH_AUTH,	"SOCKS5: Connection not allowed by ruleset" },
124	{ SOCKS5_ERR_NET_UNREACHABLE,	FETCH_NETWORK,	"SOCKS5: Network unreachable" },
125	{ SOCKS5_ERR_HOST_UNREACHABLE,	FETCH_ABORT,	"SOCKS5: Host unreachable" },
126	{ SOCKS5_ERR_CONN_REFUSED,	FETCH_ABORT,	"SOCKS5: Connection refused" },
127	{ SOCKS5_ERR_TTL_EXPIRED,	FETCH_TIMEOUT,	"SOCKS5: TTL expired" },
128	{ SOCKS5_ERR_COM_UNSUPPORTED,	FETCH_PROTO,	"SOCKS5: Command not supported" },
129	{ SOCKS5_ERR_ADDR_UNSUPPORTED,	FETCH_ABORT,	"SOCKS5: Address type not supported" },
130	{ SOCKS5_ERR_UNSPECIFIED,	FETCH_UNKNOWN,	"SOCKS5: Unspecified error" },
131/* Configuration error */
132	{ SOCKS5_ERR_BAD_HOST,		FETCH_ABORT,	"SOCKS5: Bad proxy host" },
133	{ SOCKS5_ERR_BAD_PROXY_FORMAT,	FETCH_ABORT,	"SOCKS5: Bad proxy format" },
134	{ SOCKS5_ERR_BAD_PORT,		FETCH_ABORT,	"SOCKS5: Bad port" }
135};
136
137/* End-of-Line */
138static const char ENDL[2] = "\r\n";
139
140
141/*** Error-reporting functions ***********************************************/
142
143/*
144 * Map error code to string
145 */
146static struct fetcherr *
147fetch_finderr(struct fetcherr *p, int e)
148{
149	while (p->num != -1 && p->num != e)
150		p++;
151	return (p);
152}
153
154/*
155 * Set error code
156 */
157void
158fetch_seterr(struct fetcherr *p, int e)
159{
160	p = fetch_finderr(p, e);
161	fetchLastErrCode = p->cat;
162	snprintf(fetchLastErrString, MAXERRSTRING, "%s", p->string);
163}
164
165/*
166 * Set error code according to errno
167 */
168void
169fetch_syserr(void)
170{
171	switch (errno) {
172	case 0:
173		fetchLastErrCode = FETCH_OK;
174		break;
175	case EPERM:
176	case EACCES:
177	case EROFS:
178	case EAUTH:
179	case ENEEDAUTH:
180		fetchLastErrCode = FETCH_AUTH;
181		break;
182	case ENOENT:
183	case EISDIR: /* XXX */
184		fetchLastErrCode = FETCH_UNAVAIL;
185		break;
186	case ENOMEM:
187		fetchLastErrCode = FETCH_MEMORY;
188		break;
189	case EBUSY:
190	case EAGAIN:
191		fetchLastErrCode = FETCH_TEMP;
192		break;
193	case EEXIST:
194		fetchLastErrCode = FETCH_EXISTS;
195		break;
196	case ENOSPC:
197		fetchLastErrCode = FETCH_FULL;
198		break;
199	case EADDRINUSE:
200	case EADDRNOTAVAIL:
201	case ENETDOWN:
202	case ENETUNREACH:
203	case ENETRESET:
204	case EHOSTUNREACH:
205		fetchLastErrCode = FETCH_NETWORK;
206		break;
207	case ECONNABORTED:
208	case ECONNRESET:
209		fetchLastErrCode = FETCH_ABORT;
210		break;
211	case ETIMEDOUT:
212		fetchLastErrCode = FETCH_TIMEOUT;
213		break;
214	case ECONNREFUSED:
215	case EHOSTDOWN:
216		fetchLastErrCode = FETCH_DOWN;
217		break;
218	default:
219		fetchLastErrCode = FETCH_UNKNOWN;
220	}
221	snprintf(fetchLastErrString, MAXERRSTRING, "%s", strerror(errno));
222}
223
224
225/*
226 * Emit status message
227 */
228void
229fetch_info(const char *fmt, ...)
230{
231	va_list ap;
232
233	va_start(ap, fmt);
234	vfprintf(stderr, fmt, ap);
235	va_end(ap);
236	fputc('\n', stderr);
237}
238
239
240/*** Network-related utility functions ***************************************/
241
242/*
243 * Return the default port for a scheme
244 */
245int
246fetch_default_port(const char *scheme)
247{
248	struct servent *se;
249
250	if ((se = getservbyname(scheme, "tcp")) != NULL)
251		return (ntohs(se->s_port));
252	if (strcmp(scheme, SCHEME_FTP) == 0)
253		return (FTP_DEFAULT_PORT);
254	if (strcmp(scheme, SCHEME_HTTP) == 0)
255		return (HTTP_DEFAULT_PORT);
256	return (0);
257}
258
259/*
260 * Return the default proxy port for a scheme
261 */
262int
263fetch_default_proxy_port(const char *scheme)
264{
265	if (strcmp(scheme, SCHEME_FTP) == 0)
266		return (FTP_DEFAULT_PROXY_PORT);
267	if (strcmp(scheme, SCHEME_HTTP) == 0)
268		return (HTTP_DEFAULT_PROXY_PORT);
269	return (0);
270}
271
272
273/*
274 * Create a connection for an existing descriptor.
275 */
276conn_t *
277fetch_reopen(int sd)
278{
279	conn_t *conn;
280	int opt = 1;
281
282	/* allocate and fill connection structure */
283	if ((conn = calloc(1, sizeof(*conn))) == NULL)
284		return (NULL);
285	fcntl(sd, F_SETFD, FD_CLOEXEC);
286	setsockopt(sd, SOL_SOCKET, SO_NOSIGPIPE, &opt, sizeof opt);
287	conn->sd = sd;
288	++conn->ref;
289	return (conn);
290}
291
292
293/*
294 * Bump a connection's reference count.
295 */
296conn_t *
297fetch_ref(conn_t *conn)
298{
299
300	++conn->ref;
301	return (conn);
302}
303
304
305/*
306 * Resolve an address
307 */
308struct addrinfo *
309fetch_resolve(const char *addr, int port, int af)
310{
311	char hbuf[256], sbuf[8];
312	struct addrinfo hints, *res;
313	const char *hb, *he, *sep;
314	const char *host, *service;
315	int err, len;
316
317	/* first, check for a bracketed IPv6 address */
318	if (*addr == '[') {
319		hb = addr + 1;
320		if ((sep = strchr(hb, ']')) == NULL) {
321			errno = EINVAL;
322			goto syserr;
323		}
324		he = sep++;
325	} else {
326		hb = addr;
327		sep = strchrnul(hb, ':');
328		he = sep;
329	}
330
331	/* see if we need to copy the host name */
332	if (*he != '\0') {
333		len = snprintf(hbuf, sizeof(hbuf),
334		    "%.*s", (int)(he - hb), hb);
335		if (len < 0)
336			goto syserr;
337		if (len >= (int)sizeof(hbuf)) {
338			errno = ENAMETOOLONG;
339			goto syserr;
340		}
341		host = hbuf;
342	} else {
343		host = hb;
344	}
345
346	/* was it followed by a service name? */
347	if (*sep == '\0' && port != 0) {
348		if (port < 1 || port > 65535) {
349			errno = EINVAL;
350			goto syserr;
351		}
352		if (snprintf(sbuf, sizeof(sbuf), "%d", port) < 0)
353			goto syserr;
354		service = sbuf;
355	} else if (*sep != '\0') {
356		service = sep + 1;
357	} else {
358		service = NULL;
359	}
360
361	/* resolve */
362	memset(&hints, 0, sizeof(hints));
363	hints.ai_family = af;
364	hints.ai_socktype = SOCK_STREAM;
365	hints.ai_flags = AI_ADDRCONFIG;
366	if ((err = getaddrinfo(host, service, &hints, &res)) != 0) {
367		netdb_seterr(err);
368		return (NULL);
369	}
370	return (res);
371syserr:
372	fetch_syserr();
373	return (NULL);
374}
375
376
377/*
378 * Bind a socket to a specific local address
379 */
380int
381fetch_bind(int sd, int af, const char *addr)
382{
383	struct addrinfo *cliai, *ai;
384	int err;
385
386	if ((cliai = fetch_resolve(addr, 0, af)) == NULL)
387		return (-1);
388	for (ai = cliai; ai != NULL; ai = ai->ai_next)
389		if ((err = bind(sd, ai->ai_addr, ai->ai_addrlen)) == 0)
390			break;
391	if (err != 0)
392		fetch_syserr();
393	freeaddrinfo(cliai);
394	return (err == 0 ? 0 : -1);
395}
396
397
398/*
399 * SOCKS5 connection initiation, based on RFC 1928
400 * Default DNS resolution over SOCKS5
401 */
402int
403fetch_socks5_init(conn_t *conn, const char *host, int port, int verbose)
404{
405	/*
406	 * Size is based on largest packet prefix (4 bytes) +
407	 * Largest FQDN (256) + one byte size (1) +
408	 * Port (2)
409	 */
410	unsigned char buf[BUFF_SIZE];
411	unsigned char *ptr;
412	int ret = 1;
413
414	if (verbose)
415		fetch_info("Initializing SOCKS5 connection: %s:%d", host, port);
416
417	/* Connection initialization */
418	ptr = buf;
419	*ptr++ = SOCKS_VERSION_5;
420	*ptr++ = SOCKS_CONNECTION;
421	*ptr++ = SOCKS_RSV;
422
423	if (fetch_write(conn, buf, 3) != 3) {
424		ret = SOCKS5_ERR_SELECTION;
425		goto fail;
426	}
427
428	/* Verify response from SOCKS5 server */
429	if (fetch_read(conn, buf, 2) != 2) {
430		ret = SOCKS5_ERR_READ_METHOD;
431		goto fail;
432	}
433
434	ptr = buf;
435	if (ptr[0] != SOCKS_VERSION_5) {
436		ret = SOCKS5_ERR_VER5_ONLY;
437		goto fail;
438	}
439	if (ptr[1] == SOCKS_NOMETHODS) {
440		ret = SOCKS5_ERR_NOMETHODS;
441		goto fail;
442	}
443	else if (ptr[1] != SOCKS5_NOTIMPLEMENTED) {
444		ret = SOCKS5_ERR_NOTIMPLEMENTED;
445		goto fail;
446	}
447
448	/* Send Request */
449	*ptr++ = SOCKS_VERSION_5;
450	*ptr++ = SOCKS_CONNECTION;
451	*ptr++ = SOCKS_RSV;
452	/* Encode all targets as a hostname to avoid DNS leaks */
453	*ptr++ = SOCKS_ATYP_DOMAINNAME;
454	if (strlen(host) > FQDN_SIZE) {
455		ret = SOCKS5_ERR_HOSTNAME_SIZE;
456		goto fail;
457	}
458	*ptr++ = strlen(host);
459	strncpy(ptr, host, strlen(host));
460	ptr = ptr + strlen(host);
461
462	port = htons(port);
463	*ptr++ = port & 0x00ff;
464	*ptr++ = (port & 0xff00) >> 8;
465
466	if (fetch_write(conn, buf, ptr - buf) != ptr - buf) {
467		ret = SOCKS5_ERR_REQUEST;
468		goto fail;
469	}
470
471	/* BND.ADDR is variable length, read the largest on non-blocking socket */
472	if (!fetch_read(conn, buf, BUFF_SIZE)) {
473		ret = SOCKS5_ERR_REPLY;
474		goto fail;
475	}
476
477	ptr = buf;
478	if (*ptr++ != SOCKS_VERSION_5) {
479		ret = SOCKS5_ERR_NON_VER5_RESP;
480		goto fail;
481	}
482
483	switch(*ptr++) {
484	case SOCKS_SUCCESS:
485		break;
486	case SOCKS_GENERAL_FAILURE:
487		ret = SOCKS5_ERR_GENERAL;
488		goto fail;
489	case SOCKS_CONNECTION_NOT_ALLOWED:
490		ret = SOCKS5_ERR_NOT_ALLOWED;
491		goto fail;
492	case SOCKS_NETWORK_UNREACHABLE:
493		ret = SOCKS5_ERR_NET_UNREACHABLE;
494		goto fail;
495	case SOCKS_HOST_UNREACHABLE:
496		ret = SOCKS5_ERR_HOST_UNREACHABLE;
497		goto fail;
498	case SOCKS_CONNECTION_REFUSED:
499		ret = SOCKS5_ERR_CONN_REFUSED;
500		goto fail;
501	case SOCKS_TTL_EXPIRED:
502		ret = SOCKS5_ERR_TTL_EXPIRED;
503		goto fail;
504	case SOCKS_COMMAND_NOT_SUPPORTED:
505		ret = SOCKS5_ERR_COM_UNSUPPORTED;
506		goto fail;
507	case SOCKS_ADDRESS_NOT_SUPPORTED:
508		ret = SOCKS5_ERR_ADDR_UNSUPPORTED;
509		goto fail;
510	default:
511		ret = SOCKS5_ERR_UNSPECIFIED;
512		goto fail;
513	}
514
515	return (ret);
516
517fail:
518	socks5_seterr(ret);
519	return (0);
520}
521
522/*
523 * Perform SOCKS5 initialization
524 */
525int
526fetch_socks5_getenv(char **host, int *port)
527{
528	char *socks5env, *endptr, *ext;
529	const char *portDelim;
530	size_t slen;
531
532	portDelim = ":";
533	if ((socks5env = getenv("SOCKS5_PROXY")) == NULL || *socks5env == '\0') {
534		*host = NULL;
535		*port = -1;
536		return (-1);
537	}
538
539	/*
540	 * IPv6 addresses begin and end in brackets.  Set the port delimiter
541	 * accordingly and search for it so we can do appropriate validation.
542	 */
543	if (socks5env[0] == '[')
544		portDelim = "]:";
545
546	slen = strlen(socks5env);
547	ext = strstr(socks5env, portDelim);
548	if (socks5env[0] == '[') {
549		if (socks5env[slen - 1] == ']') {
550			*host = strndup(socks5env, slen);
551		} else if (ext != NULL) {
552			*host = strndup(socks5env, ext - socks5env + 1);
553		} else {
554			socks5_seterr(SOCKS5_ERR_BAD_PROXY_FORMAT);
555			return (0);
556		}
557	} else {
558		*host = strndup(socks5env, ext - socks5env);
559	}
560
561	if (*host == NULL) {
562		fprintf(stderr, "Failure to allocate memory, exiting.\n");
563		return (-1);
564	}
565	if (ext == NULL) {
566		*port = 1080; /* Default port as defined in RFC1928 */
567	} else {
568		ext += strlen(portDelim);
569		errno = 0;
570		*port = strtoimax(ext, (char **)&endptr, 10);
571		if (*endptr != '\0' || errno != 0 || *port < 0 ||
572		    *port > 65535) {
573			free(*host);
574			*host = NULL;
575			socks5_seterr(SOCKS5_ERR_BAD_PORT);
576			return (0);
577		}
578	}
579
580	return (2);
581}
582
583
584/*
585 * Establish a TCP connection to the specified port on the specified host.
586 */
587conn_t *
588fetch_connect(const char *host, int port, int af, int verbose)
589{
590	struct addrinfo *cais = NULL, *sais = NULL, *cai, *sai;
591	const char *bindaddr;
592	conn_t *conn = NULL;
593	int err = 0, sd = -1;
594	char *sockshost;
595	int socksport;
596
597	DEBUGF("---> %s:%d\n", host, port);
598
599	/*
600	 * Check if SOCKS5_PROXY env variable is set.  fetch_socks5_getenv
601	 * will either set sockshost = NULL or allocate memory in all cases.
602	 */
603	sockshost = NULL;
604	if (!fetch_socks5_getenv(&sockshost, &socksport))
605		goto fail;
606
607	/* Not using SOCKS5 proxy */
608	if (sockshost == NULL) {
609		/* resolve server address */
610		if (verbose)
611			fetch_info("resolving server address: %s:%d", host,
612			    port);
613		if ((sais = fetch_resolve(host, port, af)) == NULL)
614			goto fail;
615
616		/* resolve client address */
617		bindaddr = getenv("FETCH_BIND_ADDRESS");
618		if (bindaddr != NULL && *bindaddr != '\0') {
619			if (verbose)
620				fetch_info("resolving client address: %s",
621				    bindaddr);
622			if ((cais = fetch_resolve(bindaddr, 0, af)) == NULL)
623				goto fail;
624		}
625	} else {
626		/* resolve socks5 proxy address */
627		if (verbose)
628			fetch_info("resolving SOCKS5 server address: %s:%d",
629			    sockshost, socksport);
630		if ((sais = fetch_resolve(sockshost, socksport, af)) == NULL) {
631			socks5_seterr(SOCKS5_ERR_BAD_HOST);
632			goto fail;
633		}
634	}
635
636	/* try each server address in turn */
637	for (err = 0, sai = sais; sai != NULL; sai = sai->ai_next) {
638		/* open socket */
639		if ((sd = socket(sai->ai_family, SOCK_STREAM, 0)) < 0)
640			goto syserr;
641		/* attempt to bind to client address */
642		for (err = 0, cai = cais; cai != NULL; cai = cai->ai_next) {
643			if (cai->ai_family != sai->ai_family)
644				continue;
645			if ((err = bind(sd, cai->ai_addr, cai->ai_addrlen)) == 0)
646				break;
647		}
648		if (err != 0) {
649			if (verbose)
650				fetch_info("failed to bind to %s", bindaddr);
651			goto syserr;
652		}
653		/* attempt to connect to server address */
654		if ((err = connect(sd, sai->ai_addr, sai->ai_addrlen)) == 0)
655			break;
656		/* clean up before next attempt */
657		close(sd);
658		sd = -1;
659	}
660	if (err != 0) {
661		if (verbose && sockshost == NULL) {
662			fetch_info("failed to connect to %s:%d", host, port);
663			goto syserr;
664		} else if (sockshost != NULL) {
665			if (verbose)
666				fetch_info(
667				    "failed to connect to SOCKS5 server %s:%d",
668				    sockshost, socksport);
669			socks5_seterr(SOCKS5_ERR_CONN_REFUSED);
670			goto fail;
671		}
672		goto syserr;
673	}
674
675	if ((conn = fetch_reopen(sd)) == NULL)
676		goto syserr;
677
678	if (sockshost)
679		if (!fetch_socks5_init(conn, host, port, verbose))
680			goto fail;
681	free(sockshost);
682	if (cais != NULL)
683		freeaddrinfo(cais);
684	if (sais != NULL)
685		freeaddrinfo(sais);
686	return (conn);
687syserr:
688	fetch_syserr();
689fail:
690	free(sockshost);
691	/* Fully close if it was opened; otherwise just don't leak the fd. */
692	if (conn != NULL)
693		fetch_close(conn);
694	else if (sd >= 0)
695		close(sd);
696	if (cais != NULL)
697		freeaddrinfo(cais);
698	if (sais != NULL)
699		freeaddrinfo(sais);
700	return (NULL);
701}
702
703#ifdef WITH_SSL
704/*
705 * Convert characters A-Z to lowercase (intentionally avoid any locale
706 * specific conversions).
707 */
708static char
709fetch_ssl_tolower(char in)
710{
711	if (in >= 'A' && in <= 'Z')
712		return (in + 32);
713	else
714		return (in);
715}
716
717/*
718 * isalpha implementation that intentionally avoids any locale specific
719 * conversions.
720 */
721static int
722fetch_ssl_isalpha(char in)
723{
724	return ((in >= 'A' && in <= 'Z') || (in >= 'a' && in <= 'z'));
725}
726
727/*
728 * Check if passed hostnames a and b are equal.
729 */
730static int
731fetch_ssl_hname_equal(const char *a, size_t alen, const char *b,
732    size_t blen)
733{
734	size_t i;
735
736	if (alen != blen)
737		return (0);
738	for (i = 0; i < alen; ++i) {
739		if (fetch_ssl_tolower(a[i]) != fetch_ssl_tolower(b[i]))
740			return (0);
741	}
742	return (1);
743}
744
745/*
746 * Check if domain label is traditional, meaning that only A-Z, a-z, 0-9
747 * and '-' (hyphen) are allowed. Hyphens have to be surrounded by alpha-
748 * numeric characters. Double hyphens (like they're found in IDN a-labels
749 * 'xn--') are not allowed. Empty labels are invalid.
750 */
751static int
752fetch_ssl_is_trad_domain_label(const char *l, size_t len, int wcok)
753{
754	size_t i;
755
756	if (!len || l[0] == '-' || l[len-1] == '-')
757		return (0);
758	for (i = 0; i < len; ++i) {
759		if (!isdigit(l[i]) &&
760		    !fetch_ssl_isalpha(l[i]) &&
761		    !(l[i] == '*' && wcok) &&
762		    !(l[i] == '-' && l[i - 1] != '-'))
763			return (0);
764	}
765	return (1);
766}
767
768/*
769 * Check if host name consists only of numbers. This might indicate an IP
770 * address, which is not a good idea for CN wildcard comparison.
771 */
772static int
773fetch_ssl_hname_is_only_numbers(const char *hostname, size_t len)
774{
775	size_t i;
776
777	for (i = 0; i < len; ++i) {
778		if (!((hostname[i] >= '0' && hostname[i] <= '9') ||
779		    hostname[i] == '.'))
780			return (0);
781	}
782	return (1);
783}
784
785/*
786 * Check if the host name h passed matches the pattern passed in m which
787 * is usually part of subjectAltName or CN of a certificate presented to
788 * the client. This includes wildcard matching. The algorithm is based on
789 * RFC6125, sections 6.4.3 and 7.2, which clarifies RFC2818 and RFC3280.
790 */
791static int
792fetch_ssl_hname_match(const char *h, size_t hlen, const char *m,
793    size_t mlen)
794{
795	int delta, hdotidx, mdot1idx, wcidx;
796	const char *hdot, *mdot1, *mdot2;
797	const char *wc; /* wildcard */
798
799	if (!(h && *h && m && *m))
800		return (0);
801	if ((wc = strnstr(m, "*", mlen)) == NULL)
802		return (fetch_ssl_hname_equal(h, hlen, m, mlen));
803	wcidx = wc - m;
804	/* hostname should not be just dots and numbers */
805	if (fetch_ssl_hname_is_only_numbers(h, hlen))
806		return (0);
807	/* only one wildcard allowed in pattern */
808	if (strnstr(wc + 1, "*", mlen - wcidx - 1) != NULL)
809		return (0);
810	/*
811	 * there must be at least two more domain labels and
812	 * wildcard has to be in the leftmost label (RFC6125)
813	 */
814	mdot1 = strnstr(m, ".", mlen);
815	if (mdot1 == NULL || mdot1 < wc || (mlen - (mdot1 - m)) < 4)
816		return (0);
817	mdot1idx = mdot1 - m;
818	mdot2 = strnstr(mdot1 + 1, ".", mlen - mdot1idx - 1);
819	if (mdot2 == NULL || (mlen - (mdot2 - m)) < 2)
820		return (0);
821	/* hostname must contain a dot and not be the 1st char */
822	hdot = strnstr(h, ".", hlen);
823	if (hdot == NULL || hdot == h)
824		return (0);
825	hdotidx = hdot - h;
826	/*
827	 * host part of hostname must be at least as long as
828	 * pattern it's supposed to match
829	 */
830	if (hdotidx < mdot1idx)
831		return (0);
832	/*
833	 * don't allow wildcards in non-traditional domain names
834	 * (IDN, A-label, U-label...)
835	 */
836	if (!fetch_ssl_is_trad_domain_label(h, hdotidx, 0) ||
837	    !fetch_ssl_is_trad_domain_label(m, mdot1idx, 1))
838		return (0);
839	/* match domain part (part after first dot) */
840	if (!fetch_ssl_hname_equal(hdot, hlen - hdotidx, mdot1,
841	    mlen - mdot1idx))
842		return (0);
843	/* match part left of wildcard */
844	if (!fetch_ssl_hname_equal(h, wcidx, m, wcidx))
845		return (0);
846	/* match part right of wildcard */
847	delta = mdot1idx - wcidx - 1;
848	if (!fetch_ssl_hname_equal(hdot - delta, delta,
849	    mdot1 - delta, delta))
850		return (0);
851	/* all tests succeeded, it's a match */
852	return (1);
853}
854
855/*
856 * Get numeric host address info - returns NULL if host was not an IP
857 * address. The caller is responsible for deallocation using
858 * freeaddrinfo(3).
859 */
860static struct addrinfo *
861fetch_ssl_get_numeric_addrinfo(const char *hostname, size_t len)
862{
863	struct addrinfo hints, *res;
864	char *host;
865
866	host = (char *)malloc(len + 1);
867	memcpy(host, hostname, len);
868	host[len] = '\0';
869	memset(&hints, 0, sizeof(hints));
870	hints.ai_family = PF_UNSPEC;
871	hints.ai_socktype = SOCK_STREAM;
872	hints.ai_protocol = 0;
873	hints.ai_flags = AI_NUMERICHOST;
874	/* port is not relevant for this purpose */
875	if (getaddrinfo(host, "443", &hints, &res) != 0)
876		res = NULL;
877	free(host);
878	return res;
879}
880
881/*
882 * Compare ip address in addrinfo with address passes.
883 */
884static int
885fetch_ssl_ipaddr_match_bin(const struct addrinfo *lhost, const char *rhost,
886    size_t rhostlen)
887{
888	const void *left;
889
890	if (lhost->ai_family == AF_INET && rhostlen == 4) {
891		left = (void *)&((struct sockaddr_in*)(void *)
892		    lhost->ai_addr)->sin_addr.s_addr;
893#ifdef INET6
894	} else if (lhost->ai_family == AF_INET6 && rhostlen == 16) {
895		left = (void *)&((struct sockaddr_in6 *)(void *)
896		    lhost->ai_addr)->sin6_addr;
897#endif
898	} else
899		return (0);
900	return (!memcmp(left, (const void *)rhost, rhostlen) ? 1 : 0);
901}
902
903/*
904 * Compare ip address in addrinfo with host passed. If host is not an IP
905 * address, comparison will fail.
906 */
907static int
908fetch_ssl_ipaddr_match(const struct addrinfo *laddr, const char *r,
909    size_t rlen)
910{
911	struct addrinfo *raddr;
912	int ret;
913	char *rip;
914
915	ret = 0;
916	if ((raddr = fetch_ssl_get_numeric_addrinfo(r, rlen)) == NULL)
917		return 0; /* not a numeric host */
918
919	if (laddr->ai_family == raddr->ai_family) {
920		if (laddr->ai_family == AF_INET) {
921			rip = (char *)&((struct sockaddr_in *)(void *)
922			    raddr->ai_addr)->sin_addr.s_addr;
923			ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 4);
924#ifdef INET6
925		} else if (laddr->ai_family == AF_INET6) {
926			rip = (char *)&((struct sockaddr_in6 *)(void *)
927			    raddr->ai_addr)->sin6_addr;
928			ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 16);
929#endif
930		}
931
932	}
933	freeaddrinfo(raddr);
934	return (ret);
935}
936
937/*
938 * Verify server certificate by subjectAltName.
939 */
940static int
941fetch_ssl_verify_altname(STACK_OF(GENERAL_NAME) *altnames,
942    const char *host, struct addrinfo *ip)
943{
944	const GENERAL_NAME *name;
945	size_t nslen;
946	int i;
947	const char *ns;
948
949	for (i = 0; i < sk_GENERAL_NAME_num(altnames); ++i) {
950#if OPENSSL_VERSION_NUMBER < 0x10000000L
951		/*
952		 * This is a workaround, since the following line causes
953		 * alignment issues in clang:
954		 * name = sk_GENERAL_NAME_value(altnames, i);
955		 * OpenSSL explicitly warns not to use those macros
956		 * directly, but there isn't much choice (and there
957		 * shouldn't be any ill side effects)
958		 */
959		name = (GENERAL_NAME *)SKM_sk_value(void, altnames, i);
960#else
961		name = sk_GENERAL_NAME_value(altnames, i);
962#endif
963#if OPENSSL_VERSION_NUMBER < 0x10100000L
964		ns = (const char *)ASN1_STRING_data(name->d.ia5);
965#else
966		ns = (const char *)ASN1_STRING_get0_data(name->d.ia5);
967#endif
968		nslen = (size_t)ASN1_STRING_length(name->d.ia5);
969
970		if (name->type == GEN_DNS && ip == NULL &&
971		    fetch_ssl_hname_match(host, strlen(host), ns, nslen))
972			return (1);
973		else if (name->type == GEN_IPADD && ip != NULL &&
974		    fetch_ssl_ipaddr_match_bin(ip, ns, nslen))
975			return (1);
976	}
977	return (0);
978}
979
980/*
981 * Verify server certificate by CN.
982 */
983static int
984fetch_ssl_verify_cn(X509_NAME *subject, const char *host,
985    struct addrinfo *ip)
986{
987	ASN1_STRING *namedata;
988	X509_NAME_ENTRY *nameentry;
989	int cnlen, lastpos, loc, ret;
990	unsigned char *cn;
991
992	ret = 0;
993	lastpos = -1;
994	loc = -1;
995	cn = NULL;
996	/* get most specific CN (last entry in list) and compare */
997	while ((lastpos = X509_NAME_get_index_by_NID(subject,
998	    NID_commonName, lastpos)) != -1)
999		loc = lastpos;
1000
1001	if (loc > -1) {
1002		nameentry = X509_NAME_get_entry(subject, loc);
1003		namedata = X509_NAME_ENTRY_get_data(nameentry);
1004		cnlen = ASN1_STRING_to_UTF8(&cn, namedata);
1005		if (ip == NULL &&
1006		    fetch_ssl_hname_match(host, strlen(host), cn, cnlen))
1007			ret = 1;
1008		else if (ip != NULL && fetch_ssl_ipaddr_match(ip, cn, cnlen))
1009			ret = 1;
1010		OPENSSL_free(cn);
1011	}
1012	return (ret);
1013}
1014
1015/*
1016 * Verify that server certificate subjectAltName/CN matches
1017 * hostname. First check, if there are alternative subject names. If yes,
1018 * those have to match. Only if those don't exist it falls back to
1019 * checking the subject's CN.
1020 */
1021static int
1022fetch_ssl_verify_hname(X509 *cert, const char *host)
1023{
1024	struct addrinfo *ip;
1025	STACK_OF(GENERAL_NAME) *altnames;
1026	X509_NAME *subject;
1027	int ret;
1028
1029	ret = 0;
1030	ip = fetch_ssl_get_numeric_addrinfo(host, strlen(host));
1031	altnames = X509_get_ext_d2i(cert, NID_subject_alt_name,
1032	    NULL, NULL);
1033
1034	if (altnames != NULL) {
1035		ret = fetch_ssl_verify_altname(altnames, host, ip);
1036	} else {
1037		subject = X509_get_subject_name(cert);
1038		if (subject != NULL)
1039			ret = fetch_ssl_verify_cn(subject, host, ip);
1040	}
1041
1042	if (ip != NULL)
1043		freeaddrinfo(ip);
1044	if (altnames != NULL)
1045		GENERAL_NAMES_free(altnames);
1046	return (ret);
1047}
1048
1049/*
1050 * Configure transport security layer based on environment.
1051 */
1052static void
1053fetch_ssl_setup_transport_layer(SSL_CTX *ctx, int verbose)
1054{
1055	long ssl_ctx_options;
1056
1057	ssl_ctx_options = SSL_OP_ALL | SSL_OP_NO_SSLv3 | SSL_OP_NO_TICKET;
1058	if (getenv("SSL_NO_TLS1") != NULL)
1059		ssl_ctx_options |= SSL_OP_NO_TLSv1;
1060	if (getenv("SSL_NO_TLS1_1") != NULL)
1061		ssl_ctx_options |= SSL_OP_NO_TLSv1_1;
1062	if (getenv("SSL_NO_TLS1_2") != NULL)
1063		ssl_ctx_options |= SSL_OP_NO_TLSv1_2;
1064	if (verbose)
1065		fetch_info("SSL options: %lx", ssl_ctx_options);
1066	SSL_CTX_set_options(ctx, ssl_ctx_options);
1067}
1068
1069
1070/*
1071 * Configure peer verification based on environment.
1072 */
1073#define LOCAL_CERT_FILE	_PATH_LOCALBASE "/etc/ssl/cert.pem"
1074#define BASE_CERT_FILE	"/etc/ssl/cert.pem"
1075static int
1076fetch_ssl_setup_peer_verification(SSL_CTX *ctx, int verbose)
1077{
1078	X509_LOOKUP *crl_lookup;
1079	X509_STORE *crl_store;
1080	const char *ca_cert_file, *ca_cert_path, *crl_file;
1081
1082	if (getenv("SSL_NO_VERIFY_PEER") == NULL) {
1083		ca_cert_file = getenv("SSL_CA_CERT_FILE");
1084		if (ca_cert_file == NULL &&
1085		    access(LOCAL_CERT_FILE, R_OK) == 0)
1086			ca_cert_file = LOCAL_CERT_FILE;
1087		if (ca_cert_file == NULL &&
1088		    access(BASE_CERT_FILE, R_OK) == 0)
1089			ca_cert_file = BASE_CERT_FILE;
1090		ca_cert_path = getenv("SSL_CA_CERT_PATH");
1091		if (verbose) {
1092			fetch_info("Peer verification enabled");
1093			if (ca_cert_file != NULL)
1094				fetch_info("Using CA cert file: %s",
1095				    ca_cert_file);
1096			if (ca_cert_path != NULL)
1097				fetch_info("Using CA cert path: %s",
1098				    ca_cert_path);
1099			if (ca_cert_file == NULL && ca_cert_path == NULL)
1100				fetch_info("Using OpenSSL default "
1101				    "CA cert file and path");
1102		}
1103		SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER,
1104		    fetch_ssl_cb_verify_crt);
1105		if (ca_cert_file != NULL || ca_cert_path != NULL)
1106			SSL_CTX_load_verify_locations(ctx, ca_cert_file,
1107			    ca_cert_path);
1108		else
1109			SSL_CTX_set_default_verify_paths(ctx);
1110		if ((crl_file = getenv("SSL_CRL_FILE")) != NULL) {
1111			if (verbose)
1112				fetch_info("Using CRL file: %s", crl_file);
1113			crl_store = SSL_CTX_get_cert_store(ctx);
1114			crl_lookup = X509_STORE_add_lookup(crl_store,
1115			    X509_LOOKUP_file());
1116			if (crl_lookup == NULL ||
1117			    !X509_load_crl_file(crl_lookup, crl_file,
1118				X509_FILETYPE_PEM)) {
1119				fprintf(stderr,
1120				    "Could not load CRL file %s\n",
1121				    crl_file);
1122				return (0);
1123			}
1124			X509_STORE_set_flags(crl_store,
1125			    X509_V_FLAG_CRL_CHECK |
1126			    X509_V_FLAG_CRL_CHECK_ALL);
1127		}
1128	}
1129	return (1);
1130}
1131
1132/*
1133 * Configure client certificate based on environment.
1134 */
1135static int
1136fetch_ssl_setup_client_certificate(SSL_CTX *ctx, int verbose)
1137{
1138	const char *client_cert_file, *client_key_file;
1139
1140	if ((client_cert_file = getenv("SSL_CLIENT_CERT_FILE")) != NULL) {
1141		client_key_file = getenv("SSL_CLIENT_KEY_FILE") != NULL ?
1142		    getenv("SSL_CLIENT_KEY_FILE") : client_cert_file;
1143		if (verbose) {
1144			fetch_info("Using client cert file: %s",
1145			    client_cert_file);
1146			fetch_info("Using client key file: %s",
1147			    client_key_file);
1148		}
1149		if (SSL_CTX_use_certificate_chain_file(ctx,
1150			client_cert_file) != 1) {
1151			fprintf(stderr,
1152			    "Could not load client certificate %s\n",
1153			    client_cert_file);
1154			return (0);
1155		}
1156		if (SSL_CTX_use_PrivateKey_file(ctx, client_key_file,
1157			SSL_FILETYPE_PEM) != 1) {
1158			fprintf(stderr,
1159			    "Could not load client key %s\n",
1160			    client_key_file);
1161			return (0);
1162		}
1163	}
1164	return (1);
1165}
1166
1167/*
1168 * Callback for SSL certificate verification, this is called on server
1169 * cert verification. It takes no decision, but informs the user in case
1170 * verification failed.
1171 */
1172int
1173fetch_ssl_cb_verify_crt(int verified, X509_STORE_CTX *ctx)
1174{
1175	X509 *crt;
1176	X509_NAME *name;
1177	char *str;
1178
1179	str = NULL;
1180	if (!verified) {
1181		if ((crt = X509_STORE_CTX_get_current_cert(ctx)) != NULL &&
1182		    (name = X509_get_subject_name(crt)) != NULL)
1183			str = X509_NAME_oneline(name, 0, 0);
1184		fprintf(stderr, "Certificate verification failed for %s\n",
1185		    str != NULL ? str : "no relevant certificate");
1186		OPENSSL_free(str);
1187	}
1188	return (verified);
1189}
1190
1191#endif
1192
1193/*
1194 * Enable SSL on a connection.
1195 */
1196int
1197fetch_ssl(conn_t *conn, const struct url *URL, int verbose)
1198{
1199#ifdef WITH_SSL
1200	int ret, ssl_err;
1201	X509_NAME *name;
1202	char *str;
1203
1204	/* Init the SSL library and context */
1205	if (!SSL_library_init()){
1206		fprintf(stderr, "SSL library init failed\n");
1207		return (-1);
1208	}
1209
1210	SSL_load_error_strings();
1211
1212	conn->ssl_meth = SSLv23_client_method();
1213	conn->ssl_ctx = SSL_CTX_new(conn->ssl_meth);
1214	SSL_CTX_set_mode(conn->ssl_ctx, SSL_MODE_AUTO_RETRY);
1215
1216	fetch_ssl_setup_transport_layer(conn->ssl_ctx, verbose);
1217	if (!fetch_ssl_setup_peer_verification(conn->ssl_ctx, verbose))
1218		return (-1);
1219	if (!fetch_ssl_setup_client_certificate(conn->ssl_ctx, verbose))
1220		return (-1);
1221
1222	conn->ssl = SSL_new(conn->ssl_ctx);
1223	if (conn->ssl == NULL) {
1224		fprintf(stderr, "SSL context creation failed\n");
1225		return (-1);
1226	}
1227	SSL_set_fd(conn->ssl, conn->sd);
1228
1229#if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT)
1230	if (!SSL_set_tlsext_host_name(conn->ssl,
1231	    __DECONST(struct url *, URL)->host)) {
1232		fprintf(stderr,
1233		    "TLS server name indication extension failed for host %s\n",
1234		    URL->host);
1235		return (-1);
1236	}
1237#endif
1238	while ((ret = SSL_connect(conn->ssl)) == -1) {
1239		ssl_err = SSL_get_error(conn->ssl, ret);
1240		if (ssl_err != SSL_ERROR_WANT_READ &&
1241		    ssl_err != SSL_ERROR_WANT_WRITE) {
1242			ERR_print_errors_fp(stderr);
1243			return (-1);
1244		}
1245	}
1246	conn->ssl_cert = SSL_get_peer_certificate(conn->ssl);
1247
1248	if (conn->ssl_cert == NULL) {
1249		fprintf(stderr, "No server SSL certificate\n");
1250		return (-1);
1251	}
1252
1253	if (getenv("SSL_NO_VERIFY_HOSTNAME") == NULL) {
1254		if (verbose)
1255			fetch_info("Verify hostname");
1256		if (!fetch_ssl_verify_hname(conn->ssl_cert, URL->host)) {
1257			fprintf(stderr,
1258			    "SSL certificate subject doesn't match host %s\n",
1259			    URL->host);
1260			return (-1);
1261		}
1262	}
1263
1264	if (verbose) {
1265		fetch_info("%s connection established using %s",
1266		    SSL_get_version(conn->ssl), SSL_get_cipher(conn->ssl));
1267		name = X509_get_subject_name(conn->ssl_cert);
1268		str = X509_NAME_oneline(name, 0, 0);
1269		fetch_info("Certificate subject: %s", str);
1270		OPENSSL_free(str);
1271		name = X509_get_issuer_name(conn->ssl_cert);
1272		str = X509_NAME_oneline(name, 0, 0);
1273		fetch_info("Certificate issuer: %s", str);
1274		OPENSSL_free(str);
1275	}
1276
1277	return (0);
1278#else
1279	(void)conn;
1280	(void)verbose;
1281	(void)URL;
1282	fprintf(stderr, "SSL support disabled\n");
1283	return (-1);
1284#endif
1285}
1286
1287#define FETCH_READ_WAIT		-2
1288#define FETCH_READ_ERROR	-1
1289#define FETCH_READ_DONE		 0
1290
1291#ifdef WITH_SSL
1292static ssize_t
1293fetch_ssl_read(SSL *ssl, char *buf, size_t len)
1294{
1295	ssize_t rlen;
1296	int ssl_err;
1297
1298	rlen = SSL_read(ssl, buf, len);
1299	if (rlen < 0) {
1300		ssl_err = SSL_get_error(ssl, rlen);
1301		if (ssl_err == SSL_ERROR_WANT_READ ||
1302		    ssl_err == SSL_ERROR_WANT_WRITE) {
1303			return (FETCH_READ_WAIT);
1304		} else {
1305			ERR_print_errors_fp(stderr);
1306			return (FETCH_READ_ERROR);
1307		}
1308	}
1309	return (rlen);
1310}
1311#endif
1312
1313static ssize_t
1314fetch_socket_read(int sd, char *buf, size_t len)
1315{
1316	ssize_t rlen;
1317
1318	rlen = read(sd, buf, len);
1319	if (rlen < 0) {
1320		if (errno == EAGAIN || (errno == EINTR && fetchRestartCalls))
1321			return (FETCH_READ_WAIT);
1322		else
1323			return (FETCH_READ_ERROR);
1324	}
1325	return (rlen);
1326}
1327
1328/*
1329 * Read a character from a connection w/ timeout
1330 */
1331ssize_t
1332fetch_read(conn_t *conn, char *buf, size_t len)
1333{
1334	struct timeval now, timeout, delta;
1335	struct pollfd pfd;
1336	ssize_t rlen;
1337	int deltams;
1338
1339	if (fetchTimeout > 0) {
1340		gettimeofday(&timeout, NULL);
1341		timeout.tv_sec += fetchTimeout;
1342	}
1343
1344	deltams = INFTIM;
1345	memset(&pfd, 0, sizeof pfd);
1346	pfd.fd = conn->sd;
1347	pfd.events = POLLIN | POLLERR;
1348
1349	for (;;) {
1350		/*
1351		 * The socket is non-blocking.  Instead of the canonical
1352		 * poll() -> read(), we do the following:
1353		 *
1354		 * 1) call read() or SSL_read().
1355		 * 2) if we received some data, return it.
1356		 * 3) if an error occurred, return -1.
1357		 * 4) if read() or SSL_read() signaled EOF, return.
1358		 * 5) if we did not receive any data but we're not at EOF,
1359		 *    call poll().
1360		 *
1361		 * In the SSL case, this is necessary because if we
1362		 * receive a close notification, we have to call
1363		 * SSL_read() one additional time after we've read
1364		 * everything we received.
1365		 *
1366		 * In the non-SSL case, it may improve performance (very
1367		 * slightly) when reading small amounts of data.
1368		 */
1369#ifdef WITH_SSL
1370		if (conn->ssl != NULL)
1371			rlen = fetch_ssl_read(conn->ssl, buf, len);
1372		else
1373#endif
1374			rlen = fetch_socket_read(conn->sd, buf, len);
1375		if (rlen >= 0) {
1376			break;
1377		} else if (rlen == FETCH_READ_ERROR) {
1378			fetch_syserr();
1379			return (-1);
1380		}
1381		// assert(rlen == FETCH_READ_WAIT);
1382		if (fetchTimeout > 0) {
1383			gettimeofday(&now, NULL);
1384			if (!timercmp(&timeout, &now, >)) {
1385				errno = ETIMEDOUT;
1386				fetch_syserr();
1387				return (-1);
1388			}
1389			timersub(&timeout, &now, &delta);
1390			deltams = delta.tv_sec * 1000 +
1391			    delta.tv_usec / 1000;;
1392		}
1393		errno = 0;
1394		pfd.revents = 0;
1395		if (poll(&pfd, 1, deltams) < 0) {
1396			if (errno == EINTR && fetchRestartCalls)
1397				continue;
1398			fetch_syserr();
1399			return (-1);
1400		}
1401	}
1402	return (rlen);
1403}
1404
1405
1406/*
1407 * Read a line of text from a connection w/ timeout
1408 */
1409#define MIN_BUF_SIZE 1024
1410
1411int
1412fetch_getln(conn_t *conn)
1413{
1414	char *tmp;
1415	size_t tmpsize;
1416	ssize_t len;
1417	char c;
1418
1419	if (conn->buf == NULL) {
1420		if ((conn->buf = malloc(MIN_BUF_SIZE)) == NULL) {
1421			errno = ENOMEM;
1422			return (-1);
1423		}
1424		conn->bufsize = MIN_BUF_SIZE;
1425	}
1426
1427	conn->buf[0] = '\0';
1428	conn->buflen = 0;
1429
1430	do {
1431		len = fetch_read(conn, &c, 1);
1432		if (len == -1)
1433			return (-1);
1434		if (len == 0)
1435			break;
1436		conn->buf[conn->buflen++] = c;
1437		if (conn->buflen == conn->bufsize) {
1438			tmp = conn->buf;
1439			tmpsize = conn->bufsize * 2 + 1;
1440			if ((tmp = realloc(tmp, tmpsize)) == NULL) {
1441				errno = ENOMEM;
1442				return (-1);
1443			}
1444			conn->buf = tmp;
1445			conn->bufsize = tmpsize;
1446		}
1447	} while (c != '\n');
1448
1449	conn->buf[conn->buflen] = '\0';
1450	DEBUGF("<<< %s", conn->buf);
1451	return (0);
1452}
1453
1454
1455/*
1456 * Write to a connection w/ timeout
1457 */
1458ssize_t
1459fetch_write(conn_t *conn, const char *buf, size_t len)
1460{
1461	struct iovec iov;
1462
1463	iov.iov_base = __DECONST(char *, buf);
1464	iov.iov_len = len;
1465	return fetch_writev(conn, &iov, 1);
1466}
1467
1468/*
1469 * Write a vector to a connection w/ timeout
1470 * Note: can modify the iovec.
1471 */
1472ssize_t
1473fetch_writev(conn_t *conn, struct iovec *iov, int iovcnt)
1474{
1475	struct timeval now, timeout, delta;
1476	struct pollfd pfd;
1477	ssize_t wlen, total;
1478	int deltams;
1479
1480	memset(&pfd, 0, sizeof pfd);
1481	if (fetchTimeout) {
1482		pfd.fd = conn->sd;
1483		pfd.events = POLLOUT | POLLERR;
1484		gettimeofday(&timeout, NULL);
1485		timeout.tv_sec += fetchTimeout;
1486	}
1487
1488	total = 0;
1489	while (iovcnt > 0) {
1490		while (fetchTimeout && pfd.revents == 0) {
1491			gettimeofday(&now, NULL);
1492			if (!timercmp(&timeout, &now, >)) {
1493				errno = ETIMEDOUT;
1494				fetch_syserr();
1495				return (-1);
1496			}
1497			timersub(&timeout, &now, &delta);
1498			deltams = delta.tv_sec * 1000 +
1499			    delta.tv_usec / 1000;
1500			errno = 0;
1501			pfd.revents = 0;
1502			if (poll(&pfd, 1, deltams) < 0) {
1503				/* POSIX compliance */
1504				if (errno == EAGAIN)
1505					continue;
1506				if (errno == EINTR && fetchRestartCalls)
1507					continue;
1508				return (-1);
1509			}
1510		}
1511		errno = 0;
1512#ifdef WITH_SSL
1513		if (conn->ssl != NULL)
1514			wlen = SSL_write(conn->ssl,
1515			    iov->iov_base, iov->iov_len);
1516		else
1517#endif
1518			wlen = writev(conn->sd, iov, iovcnt);
1519		if (wlen == 0) {
1520			/* we consider a short write a failure */
1521			/* XXX perhaps we shouldn't in the SSL case */
1522			errno = EPIPE;
1523			fetch_syserr();
1524			return (-1);
1525		}
1526		if (wlen < 0) {
1527			if (errno == EINTR && fetchRestartCalls)
1528				continue;
1529			return (-1);
1530		}
1531		total += wlen;
1532		while (iovcnt > 0 && wlen >= (ssize_t)iov->iov_len) {
1533			wlen -= iov->iov_len;
1534			iov++;
1535			iovcnt--;
1536		}
1537		if (iovcnt > 0) {
1538			iov->iov_len -= wlen;
1539			iov->iov_base = __DECONST(char *, iov->iov_base) + wlen;
1540		}
1541	}
1542	return (total);
1543}
1544
1545
1546/*
1547 * Write a line of text to a connection w/ timeout
1548 */
1549int
1550fetch_putln(conn_t *conn, const char *str, size_t len)
1551{
1552	struct iovec iov[2];
1553	int ret;
1554
1555	DEBUGF(">>> %s\n", str);
1556	iov[0].iov_base = __DECONST(char *, str);
1557	iov[0].iov_len = len;
1558	iov[1].iov_base = __DECONST(char *, ENDL);
1559	iov[1].iov_len = sizeof(ENDL);
1560	if (len == 0)
1561		ret = fetch_writev(conn, &iov[1], 1);
1562	else
1563		ret = fetch_writev(conn, iov, 2);
1564	if (ret == -1)
1565		return (-1);
1566	return (0);
1567}
1568
1569
1570/*
1571 * Close connection
1572 */
1573int
1574fetch_close(conn_t *conn)
1575{
1576	int ret;
1577
1578	if (--conn->ref > 0)
1579		return (0);
1580#ifdef WITH_SSL
1581	if (conn->ssl) {
1582		SSL_shutdown(conn->ssl);
1583		SSL_set_connect_state(conn->ssl);
1584		SSL_free(conn->ssl);
1585		conn->ssl = NULL;
1586	}
1587	if (conn->ssl_ctx) {
1588		SSL_CTX_free(conn->ssl_ctx);
1589		conn->ssl_ctx = NULL;
1590	}
1591	if (conn->ssl_cert) {
1592		X509_free(conn->ssl_cert);
1593		conn->ssl_cert = NULL;
1594	}
1595#endif
1596	ret = close(conn->sd);
1597	free(conn->buf);
1598	free(conn);
1599	return (ret);
1600}
1601
1602
1603/*** Directory-related utility functions *************************************/
1604
1605int
1606fetch_add_entry(struct url_ent **p, int *size, int *len,
1607    const char *name, struct url_stat *us)
1608{
1609	struct url_ent *tmp;
1610
1611	if (*p == NULL) {
1612		*size = 0;
1613		*len = 0;
1614	}
1615
1616	if (*len >= *size - 1) {
1617		tmp = reallocarray(*p, *size * 2 + 1, sizeof(**p));
1618		if (tmp == NULL) {
1619			errno = ENOMEM;
1620			fetch_syserr();
1621			return (-1);
1622		}
1623		*size = (*size * 2 + 1);
1624		*p = tmp;
1625	}
1626
1627	tmp = *p + *len;
1628	snprintf(tmp->name, PATH_MAX, "%s", name);
1629	memcpy(&tmp->stat, us, sizeof(*us));
1630
1631	(*len)++;
1632	(++tmp)->name[0] = 0;
1633
1634	return (0);
1635}
1636
1637
1638/*** Authentication-related utility functions ********************************/
1639
1640static const char *
1641fetch_read_word(FILE *f)
1642{
1643	static char word[1024];
1644
1645	if (fscanf(f, " %1023s ", word) != 1)
1646		return (NULL);
1647	return (word);
1648}
1649
1650static int
1651fetch_netrc_open(void)
1652{
1653	struct passwd *pwd;
1654	char fn[PATH_MAX];
1655	const char *p;
1656	int fd, serrno;
1657
1658	if ((p = getenv("NETRC")) != NULL) {
1659		DEBUGF("NETRC=%s\n", p);
1660		if (snprintf(fn, sizeof(fn), "%s", p) >= (int)sizeof(fn)) {
1661			fetch_info("$NETRC specifies a file name "
1662			    "longer than PATH_MAX");
1663			return (-1);
1664		}
1665	} else {
1666		if ((p = getenv("HOME")) == NULL) {
1667			if ((pwd = getpwuid(getuid())) == NULL ||
1668			    (p = pwd->pw_dir) == NULL)
1669				return (-1);
1670		}
1671		if (snprintf(fn, sizeof(fn), "%s/.netrc", p) >= (int)sizeof(fn))
1672			return (-1);
1673	}
1674
1675	if ((fd = open(fn, O_RDONLY)) < 0) {
1676		serrno = errno;
1677		DEBUGF("%s: %s\n", fn, strerror(serrno));
1678		errno = serrno;
1679	}
1680	return (fd);
1681}
1682
1683/*
1684 * Get authentication data for a URL from .netrc
1685 */
1686int
1687fetch_netrc_auth(struct url *url)
1688{
1689	const char *word;
1690	int serrno;
1691	FILE *f;
1692
1693	if (url->netrcfd < 0)
1694		url->netrcfd = fetch_netrc_open();
1695	if (url->netrcfd < 0)
1696		return (-1);
1697	if ((f = fdopen(url->netrcfd, "r")) == NULL) {
1698		serrno = errno;
1699		DEBUGF("fdopen(netrcfd): %s", strerror(errno));
1700		close(url->netrcfd);
1701		url->netrcfd = -1;
1702		errno = serrno;
1703		return (-1);
1704	}
1705	rewind(f);
1706	DEBUGF("searching netrc for %s\n", url->host);
1707	while ((word = fetch_read_word(f)) != NULL) {
1708		if (strcmp(word, "default") == 0) {
1709			DEBUGF("using default netrc settings\n");
1710			break;
1711		}
1712		if (strcmp(word, "machine") == 0 &&
1713		    (word = fetch_read_word(f)) != NULL &&
1714		    strcasecmp(word, url->host) == 0) {
1715			DEBUGF("using netrc settings for %s\n", word);
1716			break;
1717		}
1718	}
1719	if (word == NULL)
1720		goto ferr;
1721	while ((word = fetch_read_word(f)) != NULL) {
1722		if (strcmp(word, "login") == 0) {
1723			if ((word = fetch_read_word(f)) == NULL)
1724				goto ferr;
1725			if (snprintf(url->user, sizeof(url->user),
1726				"%s", word) > (int)sizeof(url->user)) {
1727				fetch_info("login name in .netrc is too long");
1728				url->user[0] = '\0';
1729			}
1730		} else if (strcmp(word, "password") == 0) {
1731			if ((word = fetch_read_word(f)) == NULL)
1732				goto ferr;
1733			if (snprintf(url->pwd, sizeof(url->pwd),
1734				"%s", word) > (int)sizeof(url->pwd)) {
1735				fetch_info("password in .netrc is too long");
1736				url->pwd[0] = '\0';
1737			}
1738		} else if (strcmp(word, "account") == 0) {
1739			if ((word = fetch_read_word(f)) == NULL)
1740				goto ferr;
1741			/* XXX not supported! */
1742		} else {
1743			break;
1744		}
1745	}
1746	fclose(f);
1747	url->netrcfd = -1;
1748	return (0);
1749ferr:
1750	serrno = errno;
1751	fclose(f);
1752	url->netrcfd = -1;
1753	errno = serrno;
1754	return (-1);
1755}
1756
1757/*
1758 * The no_proxy environment variable specifies a set of domains for
1759 * which the proxy should not be consulted; the contents is a comma-,
1760 * or space-separated list of domain names.  A single asterisk will
1761 * override all proxy variables and no transactions will be proxied
1762 * (for compatibility with lynx and curl, see the discussion at
1763 * <http://curl.haxx.se/mail/archive_pre_oct_99/0009.html>).
1764 */
1765int
1766fetch_no_proxy_match(const char *host)
1767{
1768	const char *no_proxy, *p, *q;
1769	size_t h_len, d_len;
1770
1771	if ((no_proxy = getenv("NO_PROXY")) == NULL &&
1772	    (no_proxy = getenv("no_proxy")) == NULL)
1773		return (0);
1774
1775	/* asterisk matches any hostname */
1776	if (strcmp(no_proxy, "*") == 0)
1777		return (1);
1778
1779	h_len = strlen(host);
1780	p = no_proxy;
1781	do {
1782		/* position p at the beginning of a domain suffix */
1783		while (*p == ',' || isspace((unsigned char)*p))
1784			p++;
1785
1786		/* position q at the first separator character */
1787		for (q = p; *q; ++q)
1788			if (*q == ',' || isspace((unsigned char)*q))
1789				break;
1790
1791		d_len = q - p;
1792		if (d_len > 0 && h_len >= d_len &&
1793		    strncasecmp(host + h_len - d_len,
1794			p, d_len) == 0) {
1795			/* domain name matches */
1796			return (1);
1797		}
1798
1799		p = q + 1;
1800	} while (*q);
1801
1802	return (0);
1803}
1804