xref: /netbsd-src/external/bsd/fetch/dist/libfetch/common.c (revision 914f0ba5d8c5120e978b2c62821c20d3f0dee25b)
1 /*	$NetBSD: common.c,v 1.7 2024/02/02 22:19:05 christos Exp $	*/
2 /*-
3  * Copyright (c) 1998-2004 Dag-Erling Co�dan Sm�rgrav
4  * Copyright (c) 2008, 2010 Joerg Sonnenberger <joerg@NetBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer
12  *    in this position and unchanged.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The name of the author may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  *
30  * $FreeBSD: common.c,v 1.53 2007/12/19 00:26:36 des Exp $
31  */
32 
33 #if HAVE_CONFIG_H
34 #include "config.h"
35 #endif
36 #ifndef NETBSD
37 #include <nbcompat.h>
38 #endif
39 
40 #include <sys/types.h>
41 #include <sys/socket.h>
42 #include <sys/time.h>
43 #include <sys/uio.h>
44 #if defined(HAVE_POLL_H) || defined(NETBSD)
45 #include <poll.h>
46 #define HAVE_POLL
47 #elif HAVE_SYS_POLL_H
48 #define HAVE_POLL
49 #include <sys/poll.h>
50 #endif
51 
52 #include <netinet/in.h>
53 #include <arpa/inet.h>
54 
55 #include <ctype.h>
56 #include <errno.h>
57 #if defined(HAVE_INTTYPES_H) || defined(NETBSD)
58 #include <inttypes.h>
59 #endif
60 #ifndef NETBSD
61 #include <nbcompat/netdb.h>
62 #else
63 #include <netdb.h>
64 #endif
65 #include <pwd.h>
66 #include <stdarg.h>
67 #include <stdlib.h>
68 #include <stdio.h>
69 #include <string.h>
70 #include <unistd.h>
71 
72 #ifndef MSG_NOSIGNAL
73 #include <signal.h>
74 #endif
75 
76 #include "fetch.h"
77 #include "common.h"
78 
79 /*** Local data **************************************************************/
80 
81 /*
82  * Error messages for resolver errors
83  */
84 static struct fetcherr netdb_errlist[] = {
85 #ifdef EAI_NODATA
86 	{ EAI_NODATA,	FETCH_RESOLV,	"Host not found" },
87 #endif
88 	{ EAI_AGAIN,	FETCH_TEMP,	"Transient resolver failure" },
89 	{ EAI_FAIL,	FETCH_RESOLV,	"Non-recoverable resolver failure" },
90 	{ EAI_NONAME,	FETCH_RESOLV,	"No address record" },
91 	{ -1,		FETCH_UNKNOWN,	"Unknown resolver error" }
92 };
93 
94 /*** Error-reporting functions ***********************************************/
95 
96 /*
97  * Map error code to string
98  */
99 static struct fetcherr *
fetch_finderr(struct fetcherr * p,int e)100 fetch_finderr(struct fetcherr *p, int e)
101 {
102 	while (p->num != -1 && p->num != e)
103 		p++;
104 	return (p);
105 }
106 
107 /*
108  * Set error code
109  */
110 void
fetch_seterr(struct fetcherr * p,int e)111 fetch_seterr(struct fetcherr *p, int e)
112 {
113 	p = fetch_finderr(p, e);
114 	fetchLastErrCode = p->cat;
115 	snprintf(fetchLastErrString, MAXERRSTRING, "%s", p->string);
116 }
117 
118 /*
119  * Set error code according to errno
120  */
121 void
fetch_syserr(void)122 fetch_syserr(void)
123 {
124 	switch (errno) {
125 	case 0:
126 		fetchLastErrCode = FETCH_OK;
127 		break;
128 	case EPERM:
129 	case EACCES:
130 	case EROFS:
131 #ifdef EAUTH
132 	case EAUTH:
133 #endif
134 #ifdef ENEEDAUTH
135 	case ENEEDAUTH:
136 #endif
137 		fetchLastErrCode = FETCH_AUTH;
138 		break;
139 	case ENOENT:
140 	case EISDIR: /* XXX */
141 		fetchLastErrCode = FETCH_UNAVAIL;
142 		break;
143 	case ENOMEM:
144 		fetchLastErrCode = FETCH_MEMORY;
145 		break;
146 	case EBUSY:
147 	case EAGAIN:
148 		fetchLastErrCode = FETCH_TEMP;
149 		break;
150 	case EEXIST:
151 		fetchLastErrCode = FETCH_EXISTS;
152 		break;
153 	case ENOSPC:
154 		fetchLastErrCode = FETCH_FULL;
155 		break;
156 	case EADDRINUSE:
157 	case EADDRNOTAVAIL:
158 	case ENETDOWN:
159 	case ENETUNREACH:
160 	case ENETRESET:
161 	case EHOSTUNREACH:
162 		fetchLastErrCode = FETCH_NETWORK;
163 		break;
164 	case ECONNABORTED:
165 	case ECONNRESET:
166 		fetchLastErrCode = FETCH_ABORT;
167 		break;
168 	case ETIMEDOUT:
169 		fetchLastErrCode = FETCH_TIMEOUT;
170 		break;
171 	case ECONNREFUSED:
172 	case EHOSTDOWN:
173 		fetchLastErrCode = FETCH_DOWN;
174 		break;
175 default:
176 		fetchLastErrCode = FETCH_UNKNOWN;
177 	}
178 	snprintf(fetchLastErrString, MAXERRSTRING, "%s", strerror(errno));
179 }
180 
181 
182 /*
183  * Emit status message
184  */
185 void
fetch_info(const char * fmt,...)186 fetch_info(const char *fmt, ...)
187 {
188 	va_list ap;
189 
190 	va_start(ap, fmt);
191 	vfprintf(stderr, fmt, ap);
192 	va_end(ap);
193 	fputc('\n', stderr);
194 }
195 
196 
197 /*** Network-related utility functions ***************************************/
198 
199 /*
200  * Return the default port for a scheme
201  */
202 int
fetch_default_port(const char * scheme)203 fetch_default_port(const char *scheme)
204 {
205 	struct servent *se;
206 
207 	if ((se = getservbyname(scheme, "tcp")) != NULL)
208 		return (ntohs(se->s_port));
209 	if (strcasecmp(scheme, SCHEME_FTP) == 0)
210 		return (FTP_DEFAULT_PORT);
211 	if (strcasecmp(scheme, SCHEME_HTTP) == 0)
212 		return (HTTP_DEFAULT_PORT);
213 	return (0);
214 }
215 
216 /*
217  * Return the default proxy port for a scheme
218  */
219 int
fetch_default_proxy_port(const char * scheme)220 fetch_default_proxy_port(const char *scheme)
221 {
222 	if (strcasecmp(scheme, SCHEME_FTP) == 0)
223 		return (FTP_DEFAULT_PROXY_PORT);
224 	if (strcasecmp(scheme, SCHEME_HTTP) == 0)
225 		return (HTTP_DEFAULT_PROXY_PORT);
226 	return (0);
227 }
228 
229 
230 /*
231  * Create a connection for an existing descriptor.
232  */
233 conn_t *
fetch_reopen(int sd)234 fetch_reopen(int sd)
235 {
236 	conn_t *conn;
237 
238 	/* allocate and fill connection structure */
239 	if ((conn = calloc(1, sizeof(*conn))) == NULL)
240 		return (NULL);
241 	conn->ftp_home = NULL;
242 	conn->cache_url = NULL;
243 	conn->next_buf = NULL;
244 	conn->next_len = 0;
245 	conn->sd = sd;
246 #ifdef HAVE_POLL
247 	conn->buf_events = POLLIN;
248 #endif
249 	return (conn);
250 }
251 
252 
253 /*
254  * Bind a socket to a specific local address
255  */
256 int
fetch_bind(int sd,int af,const char * addr)257 fetch_bind(int sd, int af, const char *addr)
258 {
259 	struct addrinfo hints, *res, *res0;
260 
261 	memset(&hints, 0, sizeof(hints));
262 	hints.ai_family = af;
263 	hints.ai_socktype = SOCK_STREAM;
264 	hints.ai_protocol = 0;
265 	if (getaddrinfo(addr, NULL, &hints, &res0))
266 		return (-1);
267 	for (res = res0; res; res = res->ai_next) {
268 		if (bind(sd, res->ai_addr, res->ai_addrlen) == 0)
269 			return (0);
270 	}
271 	return (-1);
272 }
273 
274 
275 /*
276  * Establish a TCP connection to the specified port on the specified host.
277  */
278 conn_t *
fetch_connect(struct url * url,int af,int verbose)279 fetch_connect(struct url *url, int af, int verbose)
280 {
281 	conn_t *conn;
282 	char pbuf[10];
283 	const char *bindaddr;
284 	struct addrinfo hints, *res, *res0;
285 	int sd, error;
286 
287 	if (verbose)
288 		fetch_info("looking up %s", url->host);
289 
290 	/* look up host name and set up socket address structure */
291 	snprintf(pbuf, sizeof(pbuf), "%d", url->port);
292 	memset(&hints, 0, sizeof(hints));
293 	hints.ai_family = af;
294 	hints.ai_socktype = SOCK_STREAM;
295 	hints.ai_protocol = 0;
296 	if ((error = getaddrinfo(url->host, pbuf, &hints, &res0)) != 0) {
297 		netdb_seterr(error);
298 		return (NULL);
299 	}
300 	bindaddr = getenv("FETCH_BIND_ADDRESS");
301 
302 	if (verbose)
303 		fetch_info("connecting to %s:%d", url->host, url->port);
304 
305 	/* try to connect */
306 	for (sd = -1, res = res0; res; sd = -1, res = res->ai_next) {
307 		if ((sd = socket(res->ai_family, res->ai_socktype,
308 			 res->ai_protocol)) == -1)
309 			continue;
310 		if (bindaddr != NULL && *bindaddr != '\0' &&
311 		    fetch_bind(sd, res->ai_family, bindaddr) != 0) {
312 			fetch_info("failed to bind to '%s'", bindaddr);
313 			close(sd);
314 			continue;
315 		}
316 		if (connect(sd, res->ai_addr, res->ai_addrlen) == 0)
317 			break;
318 		close(sd);
319 	}
320 	freeaddrinfo(res0);
321 	if (sd == -1) {
322 		fetch_syserr();
323 		return (NULL);
324 	}
325 
326 	if ((conn = fetch_reopen(sd)) == NULL) {
327 		fetch_syserr();
328 		close(sd);
329 		return (NULL);
330 	}
331 	conn->cache_url = fetchCopyURL(url);
332 	conn->cache_af = af;
333 	return (conn);
334 }
335 
336 static conn_t *connection_cache;
337 static int cache_global_limit = 0;
338 static int cache_per_host_limit = 0;
339 
340 /*
341  * Initialise cache with the given limits.
342  */
343 void
fetchConnectionCacheInit(int global_limit,int per_host_limit)344 fetchConnectionCacheInit(int global_limit, int per_host_limit)
345 {
346 
347 	if (global_limit < 0)
348 		cache_global_limit = INT_MAX;
349 	else if (per_host_limit > global_limit)
350 		cache_global_limit = per_host_limit;
351 	else
352 		cache_global_limit = global_limit;
353 	if (per_host_limit < 0)
354 		cache_per_host_limit = INT_MAX;
355 	else
356 		cache_per_host_limit = per_host_limit;
357 }
358 
359 /*
360  * Flush cache and free all associated resources.
361  */
362 void
fetchConnectionCacheClose(void)363 fetchConnectionCacheClose(void)
364 {
365 	conn_t *conn;
366 
367 	while ((conn = connection_cache) != NULL) {
368 		connection_cache = conn->next_cached;
369 		(*conn->cache_close)(conn);
370 	}
371 }
372 
373 /*
374  * Check connection cache for an existing entry matching
375  * protocol/host/port/user/password/family.
376  */
377 conn_t *
fetch_cache_get(const struct url * url,int af)378 fetch_cache_get(const struct url *url, int af)
379 {
380 	conn_t *conn, *last_conn = NULL;
381 
382 	for (conn = connection_cache; conn; last_conn = conn,
383 	    conn = conn->next_cached)
384 	{
385 		if (conn->cache_url->port == url->port &&
386 		    strcmp(conn->cache_url->scheme, url->scheme) == 0 &&
387 		    strcmp(conn->cache_url->host, url->host) == 0 &&
388 		    strcmp(conn->cache_url->user, url->user) == 0 &&
389 		    strcmp(conn->cache_url->pwd, url->pwd) == 0 &&
390 		    (conn->cache_af == AF_UNSPEC || af == AF_UNSPEC ||
391 		     conn->cache_af == af)) {
392 			if (last_conn != NULL)
393 				last_conn->next_cached = conn->next_cached;
394 			else
395 				connection_cache = conn->next_cached;
396 			return conn;
397 		}
398 	}
399 
400 	return NULL;
401 }
402 
403 /*
404  * Put the connection back into the cache for reuse.
405  * If the connection is freed due to LRU or if the cache
406  * is explicitly closed, the given callback is called.
407  */
408 void
fetch_cache_put(conn_t * conn,int (* closecb)(conn_t *))409 fetch_cache_put(conn_t *conn, int (*closecb)(conn_t *))
410 {
411 	conn_t *iter, *last, *oiter;
412 	int global_count, host_count, added;
413 
414 	if (conn->cache_url == NULL || cache_global_limit == 0) {
415 		(*closecb)(conn);
416 		return;
417 	}
418 
419 	global_count = host_count = 0;
420 	last = NULL;
421 	for (iter = connection_cache; iter; ) {
422 		++global_count;
423 		added = !strcmp(conn->cache_url->host, iter->cache_url->host);
424 		if (added)
425 			++host_count;
426 		if (global_count < cache_global_limit &&
427 		    host_count < cache_per_host_limit) {
428 			oiter = NULL;
429 			last = iter;
430 		} else {
431 			--global_count;
432 			if (added)
433 				--host_count;
434 			if (last != NULL)
435 				last->next_cached = iter->next_cached;
436 			else
437 				connection_cache = iter->next_cached;
438 			oiter = iter;
439 		}
440 		iter = iter->next_cached;
441 		if (oiter)
442 			(*oiter->cache_close)(oiter);
443 	}
444 
445 	conn->cache_close = closecb;
446 	conn->next_cached = connection_cache;
447 	connection_cache = conn;
448 }
449 
450 /*
451  * Enable SSL on a connection.
452  */
453 int
fetch_ssl(conn_t * conn,const struct url * URL,int verbose)454 fetch_ssl(conn_t *conn, const struct url *URL, int verbose)
455 {
456 
457 #ifdef WITH_SSL
458 	/* Init the SSL library and context */
459 	if (!SSL_library_init()){
460 		fprintf(stderr, "SSL library init failed\n");
461 		return (-1);
462 	}
463 
464 	SSL_load_error_strings();
465 
466 	conn->ssl_meth = SSLv23_client_method();
467 	conn->ssl_ctx = SSL_CTX_new(conn->ssl_meth);
468 	SSL_CTX_set_mode(conn->ssl_ctx, SSL_MODE_AUTO_RETRY);
469 	if (getenv("SSL_NO_VERIFY_PEER") == NULL) {
470 		SSL_CTX_set_default_verify_paths(conn->ssl_ctx);
471 		SSL_CTX_set_verify(conn->ssl_ctx, SSL_VERIFY_PEER, NULL);
472 	}
473 
474 	conn->ssl = SSL_new(conn->ssl_ctx);
475 	if (conn->ssl == NULL){
476 		fprintf(stderr, "SSL context creation failed\n");
477 		return (-1);
478 	}
479 	conn->buf_events = 0;
480 	SSL_set_fd(conn->ssl, conn->sd);
481 #if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT)
482 	if (!SSL_set_tlsext_host_name(conn->ssl, (char *)(uintptr_t)URL->host))
483 	{
484 		fprintf(stderr,
485 		    "TLS server name indication extension failed for host %s\n",
486 		    URL->host);
487 		return (-1);
488 	}
489 #endif
490 	if (SSL_connect(conn->ssl) == -1){
491 		ERR_print_errors_fp(stderr);
492 		return (-1);
493 	}
494 
495 	if (verbose) {
496 		X509_NAME *name;
497 		char *str;
498 
499 		fprintf(stderr, "SSL connection established using %s\n",
500 		    SSL_get_cipher(conn->ssl));
501 		conn->ssl_cert = SSL_get_peer_certificate(conn->ssl);
502 		name = X509_get_subject_name(conn->ssl_cert);
503 		str = X509_NAME_oneline(name, 0, 0);
504 		printf("Certificate subject: %s\n", str);
505 		free(str);
506 		name = X509_get_issuer_name(conn->ssl_cert);
507 		str = X509_NAME_oneline(name, 0, 0);
508 		printf("Certificate issuer: %s\n", str);
509 		free(str);
510 	}
511 
512 	return (0);
513 #else
514 	(void)conn;
515 	(void)verbose;
516 	fprintf(stderr, "SSL support disabled\n");
517 	return (-1);
518 #endif
519 }
520 
521 #ifdef HAVE_POLL
522 static int
compute_timeout(const struct timeval * tv)523 compute_timeout(const struct timeval *tv)
524 {
525 	struct timeval cur;
526 
527 	gettimeofday(&cur, NULL);
528 	return (tv->tv_sec - cur.tv_sec) * 1000
529 	    + (tv->tv_usec - cur.tv_usec) / 1000;
530 }
531 #endif
532 
533 /*
534  * Read a character from a connection w/ timeout
535  */
536 ssize_t
fetch_read(conn_t * conn,char * buf,size_t len)537 fetch_read(conn_t *conn, char *buf, size_t len)
538 {
539 	struct timeval timeout_end;
540 #ifdef HAVE_POLL
541 	struct pollfd pfd;
542 #else
543 	fd_set readfds;
544 #endif
545 	int timeout_cur;
546 	ssize_t rlen;
547 	int r;
548 
549 	if (len == 0)
550 		return 0;
551 
552 	if (conn->next_len != 0) {
553 		if (conn->next_len < len)
554 			len = conn->next_len;
555 		memmove(buf, conn->next_buf, len);
556 		conn->next_len -= len;
557 		conn->next_buf += len;
558 		return len;
559 	}
560 
561 	if (fetchTimeout) {
562 #ifndef HAVE_POLL
563 		FD_ZERO(&readfds);
564 #endif
565 		gettimeofday(&timeout_end, NULL);
566 		timeout_end.tv_sec += fetchTimeout;
567 	}
568 
569 	for (;;) {
570 #ifdef HAVE_POLL
571 		pfd.fd = conn->sd;
572 		pfd.events = conn->buf_events;
573 		if (fetchTimeout && pfd.events) {
574 			do {
575 				timeout_cur = compute_timeout(&timeout_end);
576 				if (timeout_cur < 0) {
577 					errno = ETIMEDOUT;
578 					fetch_syserr();
579 					return (-1);
580 				}
581 				errno = 0;
582 				r = poll(&pfd, 1, timeout_cur);
583 				if (r == -1) {
584 					if (errno == EINTR && fetchRestartCalls)
585 						continue;
586 					fetch_syserr();
587 					return (-1);
588 				}
589 			} while (pfd.revents == 0);
590 #else
591 		while (fetchTimeout && !FD_ISSET(conn->sd, &readfds)) {
592 			struct timeval waittv, now;
593 			FD_SET(conn->sd, &readfds);
594 			gettimeofday(&now, NULL);
595 			waittv.tv_sec = timeout_end.tv_sec - now.tv_sec;
596 			waittv.tv_usec = timeout_end.tv_usec - now.tv_usec;
597 			if (waittv.tv_usec < 0) {
598 				waittv.tv_usec += 1000000;
599 				waittv.tv_sec--;
600 			}
601 			if (waittv.tv_sec < 0) {
602 				errno = ETIMEDOUT;
603 				fetch_syserr();
604 				return (-1);
605 			}
606 			errno = 0;
607 			r = select(conn->sd + 1, &readfds, NULL, NULL, &waittv);
608 			if (r == -1) {
609 				if (errno == EINTR && fetchRestartCalls)
610 					continue;
611 				fetch_syserr();
612 				return (-1);
613 			}
614 #endif
615 		}
616 #ifdef WITH_SSL
617 		if (conn->ssl != NULL) {
618 			rlen = SSL_read(conn->ssl, buf, len);
619 			if (rlen == -1) {
620 				switch (SSL_get_error(conn->ssl, rlen)) {
621 				case SSL_ERROR_WANT_READ:
622 					conn->buf_events = POLLIN;
623 					break;
624 				case SSL_ERROR_WANT_WRITE:
625 					conn->buf_events = POLLOUT;
626 					break;
627 				default:
628 					errno = EIO;
629 					fetch_syserr();
630 					return -1;
631 				}
632 			} else {
633 				/* Assume buffering on the SSL layer. */
634 				conn->buf_events = 0;
635 			}
636 		} else
637 #endif
638 			rlen = read(conn->sd, buf, len);
639 		if (rlen >= 0)
640 			break;
641 
642 		if (errno != EINTR || !fetchRestartCalls)
643 			return (-1);
644 	}
645 	return (rlen);
646 }
647 
648 
649 /*
650  * Read a line of text from a connection w/ timeout
651  */
652 #define MIN_BUF_SIZE 1024
653 
654 int
655 fetch_getln(conn_t *conn)
656 {
657 	char *tmp, *next;
658 	size_t tmpsize;
659 	ssize_t len;
660 
661 	if (conn->buf == NULL) {
662 		if ((conn->buf = malloc(MIN_BUF_SIZE)) == NULL) {
663 			errno = ENOMEM;
664 			return (-1);
665 		}
666 		conn->bufsize = MIN_BUF_SIZE;
667 	}
668 
669 	conn->buflen = 0;
670 	next = NULL;
671 
672 	do {
673 		/*
674 		 * conn->bufsize != conn->buflen at this point,
675 		 * so the buffer can be NUL-terminated below for
676 		 * the case of len == 0.
677 		 */
678 		len = fetch_read(conn, conn->buf + conn->buflen,
679 		    conn->bufsize - conn->buflen);
680 		if (len == -1)
681 			return (-1);
682 		if (len == 0)
683 			break;
684 		next = memchr(conn->buf + conn->buflen, '\n', (size_t)len);
685 		conn->buflen += len;
686 		if (conn->buflen == conn->bufsize && next == NULL) {
687 			tmp = conn->buf;
688 			tmpsize = conn->bufsize * 2;
689 			if (tmpsize < conn->bufsize) {
690 				errno = ENOMEM;
691 				return (-1);
692 			}
693 			if ((tmp = realloc(tmp, tmpsize)) == NULL) {
694 				errno = ENOMEM;
695 				return (-1);
696 			}
697 			conn->buf = tmp;
698 			conn->bufsize = tmpsize;
699 		}
700 	} while (next == NULL);
701 
702 	if (next != NULL) {
703 		*next = '\0';
704 		conn->next_buf = next + 1;
705 		conn->next_len = conn->buflen - (conn->next_buf - conn->buf);
706 		conn->buflen = next - conn->buf;
707 	} else {
708 		conn->buf[conn->buflen] = '\0';
709 		conn->next_len = 0;
710 	}
711 	return (0);
712 }
713 
714 /*
715  * Write a vector to a connection w/ timeout
716  * Note: can modify the iovec.
717  */
718 ssize_t
719 fetch_write(conn_t *conn, const void *buf, size_t len)
720 {
721 	struct timeval now, timeout, waittv;
722 	fd_set writefds;
723 	ssize_t wlen, total;
724 	int r;
725 #ifndef MSG_NOSIGNAL
726 	static int killed_sigpipe;
727 #endif
728 
729 #ifndef MSG_NOSIGNAL
730 	if (!killed_sigpipe) {
731 		signal(SIGPIPE, SIG_IGN);
732 		killed_sigpipe = 1;
733 	}
734 #endif
735 
736 
737 	if (fetchTimeout) {
738 		FD_ZERO(&writefds);
739 		gettimeofday(&timeout, NULL);
740 		timeout.tv_sec += fetchTimeout;
741 	}
742 
743 	total = 0;
744 	while (len) {
745 		while (fetchTimeout && !FD_ISSET(conn->sd, &writefds)) {
746 			FD_SET(conn->sd, &writefds);
747 			gettimeofday(&now, NULL);
748 			waittv.tv_sec = timeout.tv_sec - now.tv_sec;
749 			waittv.tv_usec = timeout.tv_usec - now.tv_usec;
750 			if (waittv.tv_usec < 0) {
751 				waittv.tv_usec += 1000000;
752 				waittv.tv_sec--;
753 			}
754 			if (waittv.tv_sec < 0) {
755 				errno = ETIMEDOUT;
756 				fetch_syserr();
757 				return (-1);
758 			}
759 			errno = 0;
760 			r = select(conn->sd + 1, NULL, &writefds, NULL, &waittv);
761 			if (r == -1) {
762 				if (errno == EINTR && fetchRestartCalls)
763 					continue;
764 				return (-1);
765 			}
766 		}
767 		errno = 0;
768 #ifdef WITH_SSL
769 		if (conn->ssl != NULL)
770 			wlen = SSL_write(conn->ssl, buf, (int)len);
771 		else
772 #endif
773 #ifndef MSG_NOSIGNAL
774 			wlen = send(conn->sd, buf, len, 0);
775 #else
776 			wlen = send(conn->sd, buf, len, MSG_NOSIGNAL);
777 #endif
778 		if (wlen == 0) {
779 			/* we consider a short write a failure */
780 			errno = EPIPE;
781 			fetch_syserr();
782 			return (-1);
783 		}
784 		if (wlen < 0) {
785 			if (errno == EINTR && fetchRestartCalls)
786 				continue;
787 			return (-1);
788 		}
789 		total += wlen;
790 		buf = (const char *)buf + wlen;
791 		len -= wlen;
792 	}
793 	return (total);
794 }
795 
796 
797 /*
798  * Close connection
799  */
800 int
801 fetch_close(conn_t *conn)
802 {
803 	int ret;
804 
805 #ifdef WITH_SSL
806 	if (conn->ssl) {
807 		SSL_shutdown(conn->ssl);
808 		SSL_set_connect_state(conn->ssl);
809 		SSL_free(conn->ssl);
810 		conn->ssl = NULL;
811 	}
812 	if (conn->ssl_ctx) {
813 		SSL_CTX_free(conn->ssl_ctx);
814 		conn->ssl_ctx = NULL;
815 	}
816 	if (conn->ssl_cert) {
817 		X509_free(conn->ssl_cert);
818 		conn->ssl_cert = NULL;
819 	}
820 #endif
821 	ret = close(conn->sd);
822 	if (conn->cache_url)
823 		fetchFreeURL(conn->cache_url);
824 	free(conn->ftp_home);
825 	free(conn->buf);
826 	free(conn);
827 	return (ret);
828 }
829 
830 
831 /*** Directory-related utility functions *************************************/
832 
833 int
834 fetch_add_entry(struct url_list *ue, struct url *base, const char *name,
835     int pre_quoted)
836 {
837 	struct url *tmp;
838 	char *tmp_name;
839 	size_t base_doc_len, name_len, i;
840 	unsigned char c;
841 
842 	if (strchr(name, '/') != NULL ||
843 	    strcmp(name, "..") == 0 ||
844 	    strcmp(name, ".") == 0)
845 		return 0;
846 
847 	if (strcmp(base->doc, "/") == 0)
848 		base_doc_len = 0;
849 	else
850 		base_doc_len = strlen(base->doc);
851 
852 	name_len = 1;
853 	for (i = 0; name[i] != '\0'; ++i) {
854 		if ((!pre_quoted && name[i] == '%') ||
855 		    !fetch_urlpath_safe(name[i]))
856 			name_len += 3;
857 		else
858 			++name_len;
859 	}
860 
861 	tmp_name = malloc( base_doc_len + name_len + 1);
862 	if (tmp_name == NULL) {
863 		errno = ENOMEM;
864 		fetch_syserr();
865 		return (-1);
866 	}
867 
868 	if (ue->length + 1 >= ue->alloc_size) {
869 		tmp = realloc(ue->urls, (ue->alloc_size * 2 + 1) * sizeof(*tmp));
870 		if (tmp == NULL) {
871 			free(tmp_name);
872 			errno = ENOMEM;
873 			fetch_syserr();
874 			return (-1);
875 		}
876 		ue->alloc_size = ue->alloc_size * 2 + 1;
877 		ue->urls = tmp;
878 	}
879 
880 	tmp = ue->urls + ue->length;
881 	strcpy(tmp->scheme, base->scheme);
882 	strcpy(tmp->user, base->user);
883 	strcpy(tmp->pwd, base->pwd);
884 	strcpy(tmp->host, base->host);
885 	tmp->port = base->port;
886 	tmp->doc = tmp_name;
887 	memcpy(tmp->doc, base->doc, base_doc_len);
888 	tmp->doc[base_doc_len] = '/';
889 
890 	for (i = base_doc_len + 1; *name != '\0'; ++name) {
891 		if ((!pre_quoted && *name == '%') ||
892 		    !fetch_urlpath_safe(*name)) {
893 			tmp->doc[i++] = '%';
894 			c = (unsigned char)*name / 16;
895 			if (c < 10)
896 				tmp->doc[i++] = '0' + c;
897 			else
898 				tmp->doc[i++] = 'a' - 10 + c;
899 			c = (unsigned char)*name % 16;
900 			if (c < 10)
901 				tmp->doc[i++] = '0' + c;
902 			else
903 				tmp->doc[i++] = 'a' - 10 + c;
904 		} else {
905 			tmp->doc[i++] = *name;
906 		}
907 	}
908 	tmp->doc[i] = '\0';
909 
910 	tmp->offset = 0;
911 	tmp->length = 0;
912 	tmp->last_modified = -1;
913 
914 	++ue->length;
915 
916 	return (0);
917 }
918 
919 void
920 fetchInitURLList(struct url_list *ue)
921 {
922 	ue->length = ue->alloc_size = 0;
923 	ue->urls = NULL;
924 }
925 
926 int
927 fetchAppendURLList(struct url_list *dst, const struct url_list *src)
928 {
929 	size_t i, j, len;
930 
931 	len = dst->length + src->length;
932 	if (len > dst->alloc_size) {
933 		struct url *tmp;
934 
935 		tmp = realloc(dst->urls, len * sizeof(*tmp));
936 		if (tmp == NULL) {
937 			errno = ENOMEM;
938 			fetch_syserr();
939 			return (-1);
940 		}
941 		dst->alloc_size = len;
942 		dst->urls = tmp;
943 	}
944 
945 	for (i = 0, j = dst->length; i < src->length; ++i, ++j) {
946 		dst->urls[j] = src->urls[i];
947 		dst->urls[j].doc = strdup(src->urls[i].doc);
948 		if (dst->urls[j].doc == NULL) {
949 			while (i-- > 0)
950 				free(dst->urls[j].doc);
951 			fetch_syserr();
952 			return -1;
953 		}
954 	}
955 	dst->length = len;
956 
957 	return 0;
958 }
959 
960 void
961 fetchFreeURLList(struct url_list *ue)
962 {
963 	size_t i;
964 
965 	for (i = 0; i < ue->length; ++i)
966 		free(ue->urls[i].doc);
967 	free(ue->urls);
968 	ue->length = ue->alloc_size = 0;
969 }
970 
971 
972 /*** Authentication-related utility functions ********************************/
973 
974 static const char *
975 fetch_read_word(FILE *f)
976 {
977 	static char word[1024];
978 
979 	if (fscanf(f, " %1023s ", word) != 1)
980 		return (NULL);
981 	return (word);
982 }
983 
984 /*
985  * Get authentication data for a URL from .netrc
986  */
987 int
988 fetch_netrc_auth(struct url *url)
989 {
990 	char fn[PATH_MAX];
991 	const char *word;
992 	char *p;
993 	FILE *f;
994 
995 	if ((p = getenv("NETRC")) != NULL) {
996 		if (snprintf(fn, sizeof(fn), "%s", p) >= (int)sizeof(fn)) {
997 			fetch_info("$NETRC specifies a file name "
998 			    "longer than PATH_MAX");
999 			return (-1);
1000 		}
1001 	} else {
1002 		if ((p = getenv("HOME")) != NULL) {
1003 			struct passwd *pwd;
1004 
1005 			if ((pwd = getpwuid(getuid())) == NULL ||
1006 			    (p = pwd->pw_dir) == NULL)
1007 				return (-1);
1008 		}
1009 		if (snprintf(fn, sizeof(fn), "%s/.netrc", p) >= (int)sizeof(fn))
1010 			return (-1);
1011 	}
1012 
1013 	if ((f = fopen(fn, "r")) == NULL)
1014 		return (-1);
1015 	while ((word = fetch_read_word(f)) != NULL) {
1016 		if (strcmp(word, "default") == 0)
1017 			break;
1018 		if (strcmp(word, "machine") == 0 &&
1019 		    (word = fetch_read_word(f)) != NULL &&
1020 		    strcasecmp(word, url->host) == 0) {
1021 			break;
1022 		}
1023 	}
1024 	if (word == NULL)
1025 		goto ferr;
1026 	while ((word = fetch_read_word(f)) != NULL) {
1027 		if (strcmp(word, "login") == 0) {
1028 			if ((word = fetch_read_word(f)) == NULL)
1029 				goto ferr;
1030 			if (snprintf(url->user, sizeof(url->user),
1031 				"%s", word) > (int)sizeof(url->user)) {
1032 				fetch_info("login name in .netrc is too long");
1033 				url->user[0] = '\0';
1034 			}
1035 		} else if (strcmp(word, "password") == 0) {
1036 			if ((word = fetch_read_word(f)) == NULL)
1037 				goto ferr;
1038 			if (snprintf(url->pwd, sizeof(url->pwd),
1039 				"%s", word) > (int)sizeof(url->pwd)) {
1040 				fetch_info("password in .netrc is too long");
1041 				url->pwd[0] = '\0';
1042 			}
1043 		} else if (strcmp(word, "account") == 0) {
1044 			if ((word = fetch_read_word(f)) == NULL)
1045 				goto ferr;
1046 			/* XXX not supported! */
1047 		} else {
1048 			break;
1049 		}
1050 	}
1051 	fclose(f);
1052 	return (0);
1053  ferr:
1054 	fclose(f);
1055 	return (-1);
1056 }
1057 
1058 /*
1059  * The no_proxy environment variable specifies a set of domains for
1060  * which the proxy should not be consulted; the contents is a comma-,
1061  * or space-separated list of domain names.  A single asterisk will
1062  * override all proxy variables and no transactions will be proxied
1063  * (for compatability with lynx and curl, see the discussion at
1064  * <http://curl.haxx.se/mail/archive_pre_oct_99/0009.html>).
1065  */
1066 int
1067 fetch_no_proxy_match(const char *host)
1068 {
1069 	const char *no_proxy, *p, *q;
1070 	size_t h_len, d_len;
1071 
1072 	if ((no_proxy = getenv("NO_PROXY")) == NULL &&
1073 	    (no_proxy = getenv("no_proxy")) == NULL)
1074 		return (0);
1075 
1076 	/* asterisk matches any hostname */
1077 	if (strcmp(no_proxy, "*") == 0)
1078 		return (1);
1079 
1080 	h_len = strlen(host);
1081 	p = no_proxy;
1082 	do {
1083 		/* position p at the beginning of a domain suffix */
1084 		while (*p == ',' || isspace((unsigned char)*p))
1085 			p++;
1086 
1087 		/* position q at the first separator character */
1088 		for (q = p; *q; ++q)
1089 			if (*q == ',' || isspace((unsigned char)*q))
1090 				break;
1091 
1092 		d_len = q - p;
1093 		if (d_len > 0 && h_len > d_len &&
1094 		    strncasecmp(host + h_len - d_len,
1095 			p, d_len) == 0) {
1096 			/* domain name matches */
1097 			return (1);
1098 		}
1099 
1100 		p = q + 1;
1101 	} while (*q);
1102 
1103 	return (0);
1104 }
1105 
1106 struct fetchIO {
1107 	void *io_cookie;
1108 	ssize_t (*io_read)(void *, void *, size_t);
1109 	ssize_t (*io_write)(void *, const void *, size_t);
1110 	void (*io_close)(void *);
1111 };
1112 
1113 void
1114 fetchIO_close(fetchIO *f)
1115 {
1116 	if (f->io_close != NULL)
1117 		(*f->io_close)(f->io_cookie);
1118 
1119 	free(f);
1120 }
1121 
1122 fetchIO *
1123 fetchIO_unopen(void *io_cookie, ssize_t (*io_read)(void *, void *, size_t),
1124     ssize_t (*io_write)(void *, const void *, size_t),
1125     void (*io_close)(void *))
1126 {
1127 	fetchIO *f;
1128 
1129 	f = malloc(sizeof(*f));
1130 	if (f == NULL)
1131 		return f;
1132 
1133 	f->io_cookie = io_cookie;
1134 	f->io_read = io_read;
1135 	f->io_write = io_write;
1136 	f->io_close = io_close;
1137 
1138 	return f;
1139 }
1140 
1141 ssize_t
1142 fetchIO_read(fetchIO *f, void *buf, size_t len)
1143 {
1144 	if (f->io_read == NULL)
1145 		return EBADF;
1146 	return (*f->io_read)(f->io_cookie, buf, len);
1147 }
1148 
1149 ssize_t
1150 fetchIO_write(fetchIO *f, const void *buf, size_t len)
1151 {
1152 	if (f->io_read == NULL)
1153 		return EBADF;
1154 	return (*f->io_write)(f->io_cookie, buf, len);
1155 }
1156