xref: /dflybsd-src/lib/libfetch/common.c (revision ba1d801e083c520ff4cb89128deda9b887d6fd0b)
1 /*-
2  * Copyright (c) 1998-2004 Dag-Erling Co�dan Sm�rgrav
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer
10  *    in this position and unchanged.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  *
28  * $FreeBSD: src/lib/libfetch/common.c,v 1.56 2008/04/15 23:29:51 cperciva Exp $
29  */
30 
31 #include <sys/param.h>
32 #include <sys/socket.h>
33 #include <sys/time.h>
34 #include <sys/uio.h>
35 
36 #include <netinet/in.h>
37 
38 #include <ctype.h>
39 #include <errno.h>
40 #include <netdb.h>
41 #include <pwd.h>
42 #include <stdarg.h>
43 #include <stdlib.h>
44 #include <stdio.h>
45 #include <string.h>
46 #include <unistd.h>
47 
48 #include "fetch.h"
49 #include "common.h"
50 
51 
52 /*** Local data **************************************************************/
53 
54 /*
55  * Error messages for resolver errors
56  */
57 static struct fetcherr netdb_errlist[] = {
58 #ifdef EAI_NODATA
59 	{ EAI_NODATA,	FETCH_RESOLV,	"Host not found" },
60 #endif
61 	{ EAI_AGAIN,	FETCH_TEMP,	"Transient resolver failure" },
62 	{ EAI_FAIL,	FETCH_RESOLV,	"Non-recoverable resolver failure" },
63 	{ EAI_NONAME,	FETCH_RESOLV,	"No address record" },
64 	{ -1,		FETCH_UNKNOWN,	"Unknown resolver error" }
65 };
66 
67 /* End-of-Line */
68 static const char ENDL[2] = "\r\n";
69 
70 
71 /*** Error-reporting functions ***********************************************/
72 
73 /*
74  * Map error code to string
75  */
76 static struct fetcherr *
77 fetch_finderr(struct fetcherr *p, int e)
78 {
79 	while (p->num != -1 && p->num != e)
80 		p++;
81 	return (p);
82 }
83 
84 /*
85  * Set error code
86  */
87 void
88 fetch_seterr(struct fetcherr *p, int e)
89 {
90 	p = fetch_finderr(p, e);
91 	fetchLastErrCode = p->cat;
92 	snprintf(fetchLastErrString, MAXERRSTRING, "%s", p->string);
93 }
94 
95 /*
96  * Set error code according to errno
97  */
98 void
99 fetch_syserr(void)
100 {
101 	switch (errno) {
102 	case 0:
103 		fetchLastErrCode = FETCH_OK;
104 		break;
105 	case EPERM:
106 	case EACCES:
107 	case EROFS:
108 	case EAUTH:
109 	case ENEEDAUTH:
110 		fetchLastErrCode = FETCH_AUTH;
111 		break;
112 	case ENOENT:
113 	case EISDIR: /* XXX */
114 		fetchLastErrCode = FETCH_UNAVAIL;
115 		break;
116 	case ENOMEM:
117 		fetchLastErrCode = FETCH_MEMORY;
118 		break;
119 	case EBUSY:
120 	case EAGAIN:
121 		fetchLastErrCode = FETCH_TEMP;
122 		break;
123 	case EEXIST:
124 		fetchLastErrCode = FETCH_EXISTS;
125 		break;
126 	case ENOSPC:
127 		fetchLastErrCode = FETCH_FULL;
128 		break;
129 	case EADDRINUSE:
130 	case EADDRNOTAVAIL:
131 	case ENETDOWN:
132 	case ENETUNREACH:
133 	case ENETRESET:
134 	case EHOSTUNREACH:
135 		fetchLastErrCode = FETCH_NETWORK;
136 		break;
137 	case ECONNABORTED:
138 	case ECONNRESET:
139 		fetchLastErrCode = FETCH_ABORT;
140 		break;
141 	case ETIMEDOUT:
142 		fetchLastErrCode = FETCH_TIMEOUT;
143 		break;
144 	case ECONNREFUSED:
145 	case EHOSTDOWN:
146 		fetchLastErrCode = FETCH_DOWN;
147 		break;
148 default:
149 		fetchLastErrCode = FETCH_UNKNOWN;
150 	}
151 	snprintf(fetchLastErrString, MAXERRSTRING, "%s", strerror(errno));
152 }
153 
154 
155 /*
156  * Emit status message
157  */
158 void
159 fetch_info(const char *fmt, ...)
160 {
161 	va_list ap;
162 
163 	va_start(ap, fmt);
164 	vfprintf(stderr, fmt, ap);
165 	va_end(ap);
166 	fputc('\n', stderr);
167 }
168 
169 
170 /*** Network-related utility functions ***************************************/
171 
172 /*
173  * Return the default port for a scheme
174  */
175 int
176 fetch_default_port(const char *scheme)
177 {
178 	struct servent *se;
179 
180 	if ((se = getservbyname(scheme, "tcp")) != NULL)
181 		return (ntohs(se->s_port));
182 	if (strcasecmp(scheme, SCHEME_FTP) == 0)
183 		return (FTP_DEFAULT_PORT);
184 	if (strcasecmp(scheme, SCHEME_HTTP) == 0)
185 		return (HTTP_DEFAULT_PORT);
186 	return (0);
187 }
188 
189 /*
190  * Return the default proxy port for a scheme
191  */
192 int
193 fetch_default_proxy_port(const char *scheme)
194 {
195 	if (strcasecmp(scheme, SCHEME_FTP) == 0)
196 		return (FTP_DEFAULT_PROXY_PORT);
197 	if (strcasecmp(scheme, SCHEME_HTTP) == 0)
198 		return (HTTP_DEFAULT_PROXY_PORT);
199 	return (0);
200 }
201 
202 
203 /*
204  * Create a connection for an existing descriptor.
205  */
206 conn_t *
207 fetch_reopen(int sd)
208 {
209 	conn_t *conn;
210 
211 	/* allocate and fill connection structure */
212 	if ((conn = calloc(1, sizeof(*conn))) == NULL)
213 		return (NULL);
214 	conn->sd = sd;
215 	++conn->ref;
216 	return (conn);
217 }
218 
219 
220 /*
221  * Bump a connection's reference count.
222  */
223 conn_t *
224 fetch_ref(conn_t *conn)
225 {
226 
227 	++conn->ref;
228 	return (conn);
229 }
230 
231 
232 /*
233  * Bind a socket to a specific local address
234  */
235 int
236 fetch_bind(int sd, int af, const char *addr)
237 {
238 	struct addrinfo hints, *res, *res0;
239 	int err;
240 
241 	memset(&hints, 0, sizeof(hints));
242 	hints.ai_family = af;
243 	hints.ai_socktype = SOCK_STREAM;
244 	hints.ai_protocol = 0;
245 	if ((err = getaddrinfo(addr, NULL, &hints, &res0)) != 0)
246 		return (-1);
247 	for (res = res0; res; res = res->ai_next)
248 		if (bind(sd, res->ai_addr, res->ai_addrlen) == 0)
249 			return (0);
250 	return (-1);
251 }
252 
253 
254 /*
255  * Establish a TCP connection to the specified port on the specified host.
256  */
257 conn_t *
258 fetch_connect(const char *host, int port, int af, int verbose)
259 {
260 	conn_t *conn;
261 	char pbuf[10];
262 	const char *bindaddr;
263 	struct addrinfo hints, *res, *res0;
264 	int sd, err;
265 
266 	DEBUG(fprintf(stderr, "---> %s:%d\n", host, port));
267 
268 	if (verbose)
269 		fetch_info("looking up %s", host);
270 
271 	/* look up host name and set up socket address structure */
272 	snprintf(pbuf, sizeof(pbuf), "%d", port);
273 	memset(&hints, 0, sizeof(hints));
274 	hints.ai_family = af;
275 	hints.ai_socktype = SOCK_STREAM;
276 	hints.ai_protocol = 0;
277 	if ((err = getaddrinfo(host, pbuf, &hints, &res0)) != 0) {
278 		netdb_seterr(err);
279 		return (NULL);
280 	}
281 	bindaddr = getenv("FETCH_BIND_ADDRESS");
282 
283 	if (verbose)
284 		fetch_info("connecting to %s:%d", host, port);
285 
286 	/* try to connect */
287 	for (sd = -1, res = res0; res; sd = -1, res = res->ai_next) {
288 		if ((sd = socket(res->ai_family, res->ai_socktype,
289 			 res->ai_protocol)) == -1)
290 			continue;
291 		if (bindaddr != NULL && *bindaddr != '\0' &&
292 		    fetch_bind(sd, res->ai_family, bindaddr) != 0) {
293 			fetch_info("failed to bind to '%s'", bindaddr);
294 			close(sd);
295 			continue;
296 		}
297 		if (connect(sd, res->ai_addr, res->ai_addrlen) == 0)
298 			break;
299 		close(sd);
300 	}
301 	freeaddrinfo(res0);
302 	if (sd == -1) {
303 		fetch_syserr();
304 		return (NULL);
305 	}
306 
307 	if ((conn = fetch_reopen(sd)) == NULL) {
308 		fetch_syserr();
309 		close(sd);
310 	}
311 	return (conn);
312 }
313 
314 
315 /*
316  * Enable SSL on a connection.
317  */
318 int
319 fetch_ssl(conn_t *conn, int verbose)
320 {
321 
322 #ifdef WITH_SSL
323 	/* Init the SSL library and context */
324 	if (!SSL_library_init()){
325 		fprintf(stderr, "SSL library init failed\n");
326 		return (-1);
327 	}
328 
329 	SSL_load_error_strings();
330 
331 	conn->ssl_meth = SSLv23_client_method();
332 	conn->ssl_ctx = SSL_CTX_new(conn->ssl_meth);
333 	SSL_CTX_set_mode(conn->ssl_ctx, SSL_MODE_AUTO_RETRY);
334 
335 	conn->ssl = SSL_new(conn->ssl_ctx);
336 	if (conn->ssl == NULL){
337 		fprintf(stderr, "SSL context creation failed\n");
338 		return (-1);
339 	}
340 	SSL_set_fd(conn->ssl, conn->sd);
341 	if (SSL_connect(conn->ssl) == -1){
342 		ERR_print_errors_fp(stderr);
343 		return (-1);
344 	}
345 
346 	if (verbose) {
347 		X509_NAME *name;
348 		char *str;
349 
350 		fprintf(stderr, "SSL connection established using %s\n",
351 		    SSL_get_cipher(conn->ssl));
352 		conn->ssl_cert = SSL_get_peer_certificate(conn->ssl);
353 		name = X509_get_subject_name(conn->ssl_cert);
354 		str = X509_NAME_oneline(name, 0, 0);
355 		printf("Certificate subject: %s\n", str);
356 		free(str);
357 		name = X509_get_issuer_name(conn->ssl_cert);
358 		str = X509_NAME_oneline(name, 0, 0);
359 		printf("Certificate issuer: %s\n", str);
360 		free(str);
361 	}
362 
363 	return (0);
364 #else
365 	(void)conn;
366 	(void)verbose;
367 	fprintf(stderr, "SSL support disabled\n");
368 	return (-1);
369 #endif
370 }
371 
372 
373 /*
374  * Read a character from a connection w/ timeout
375  */
376 ssize_t
377 fetch_read(conn_t *conn, char *buf, size_t len)
378 {
379 	struct timeval now, timeout, delta;
380 	fd_set readfds;
381 	ssize_t rlen, total;
382 	int r;
383 
384 	if (fetchTimeout) {
385 		FD_ZERO(&readfds);
386 		gettimeofday(&timeout, NULL);
387 		timeout.tv_sec += fetchTimeout;
388 	}
389 
390 	total = 0;
391 	while (len > 0) {
392 		while (fetchTimeout && !FD_ISSET(conn->sd, &readfds)) {
393 			FD_SET(conn->sd, &readfds);
394 			gettimeofday(&now, NULL);
395 			delta.tv_sec = timeout.tv_sec - now.tv_sec;
396 			delta.tv_usec = timeout.tv_usec - now.tv_usec;
397 			if (delta.tv_usec < 0) {
398 				delta.tv_usec += 1000000;
399 				delta.tv_sec--;
400 			}
401 			if (delta.tv_sec < 0) {
402 				errno = ETIMEDOUT;
403 				fetch_syserr();
404 				return (-1);
405 			}
406 			errno = 0;
407 			r = select(conn->sd + 1, &readfds, NULL, NULL, &delta);
408 			if (r == -1) {
409 				if (errno == EINTR && fetchRestartCalls)
410 					continue;
411 				fetch_syserr();
412 				return (-1);
413 			}
414 		}
415 #ifdef WITH_SSL
416 		if (conn->ssl != NULL)
417 			rlen = SSL_read(conn->ssl, buf, len);
418 		else
419 #endif
420 			rlen = read(conn->sd, buf, len);
421 		if (rlen == 0)
422 			break;
423 		if (rlen < 0) {
424 			if (errno == EINTR && fetchRestartCalls)
425 				continue;
426 			return (-1);
427 		}
428 		len -= rlen;
429 		buf += rlen;
430 		total += rlen;
431 	}
432 	return (total);
433 }
434 
435 
436 /*
437  * Read a line of text from a connection w/ timeout
438  */
439 #define MIN_BUF_SIZE 1024
440 
441 int
442 fetch_getln(conn_t *conn)
443 {
444 	char *tmp;
445 	size_t tmpsize;
446 	ssize_t len;
447 	char c;
448 
449 	if (conn->buf == NULL) {
450 		if ((conn->buf = malloc(MIN_BUF_SIZE)) == NULL) {
451 			errno = ENOMEM;
452 			return (-1);
453 		}
454 		conn->bufsize = MIN_BUF_SIZE;
455 	}
456 
457 	conn->buf[0] = '\0';
458 	conn->buflen = 0;
459 
460 	do {
461 		len = fetch_read(conn, &c, 1);
462 		if (len == -1)
463 			return (-1);
464 		if (len == 0)
465 			break;
466 		conn->buf[conn->buflen++] = c;
467 		if (conn->buflen == conn->bufsize) {
468 			tmp = conn->buf;
469 			tmpsize = conn->bufsize * 2 + 1;
470 			if ((tmp = realloc(tmp, tmpsize)) == NULL) {
471 				errno = ENOMEM;
472 				return (-1);
473 			}
474 			conn->buf = tmp;
475 			conn->bufsize = tmpsize;
476 		}
477 	} while (c != '\n');
478 
479 	conn->buf[conn->buflen] = '\0';
480 	DEBUG(fprintf(stderr, "<<< %s", conn->buf));
481 	return (0);
482 }
483 
484 
485 /*
486  * Write to a connection w/ timeout
487  */
488 ssize_t
489 fetch_write(conn_t *conn, const char *buf, size_t len)
490 {
491 	struct iovec iov;
492 
493 	iov.iov_base = __DECONST(char *, buf);
494 	iov.iov_len = len;
495 	return fetch_writev(conn, &iov, 1);
496 }
497 
498 /*
499  * Write a vector to a connection w/ timeout
500  * Note: can modify the iovec.
501  */
502 ssize_t
503 fetch_writev(conn_t *conn, struct iovec *iov, int iovcnt)
504 {
505 	struct timeval now, timeout, delta;
506 	fd_set writefds;
507 	ssize_t wlen, total;
508 	int r;
509 
510 	if (fetchTimeout) {
511 		FD_ZERO(&writefds);
512 		gettimeofday(&timeout, NULL);
513 		timeout.tv_sec += fetchTimeout;
514 	}
515 
516 	total = 0;
517 	while (iovcnt > 0) {
518 		while (fetchTimeout && !FD_ISSET(conn->sd, &writefds)) {
519 			FD_SET(conn->sd, &writefds);
520 			gettimeofday(&now, NULL);
521 			delta.tv_sec = timeout.tv_sec - now.tv_sec;
522 			delta.tv_usec = timeout.tv_usec - now.tv_usec;
523 			if (delta.tv_usec < 0) {
524 				delta.tv_usec += 1000000;
525 				delta.tv_sec--;
526 			}
527 			if (delta.tv_sec < 0) {
528 				errno = ETIMEDOUT;
529 				fetch_syserr();
530 				return (-1);
531 			}
532 			errno = 0;
533 			r = select(conn->sd + 1, NULL, &writefds, NULL, &delta);
534 			if (r == -1) {
535 				if (errno == EINTR && fetchRestartCalls)
536 					continue;
537 				return (-1);
538 			}
539 		}
540 		errno = 0;
541 #ifdef WITH_SSL
542 		if (conn->ssl != NULL)
543 			wlen = SSL_write(conn->ssl,
544 			    iov->iov_base, iov->iov_len);
545 		else
546 #endif
547 			wlen = writev(conn->sd, iov, iovcnt);
548 		if (wlen == 0) {
549 			/* we consider a short write a failure */
550 			errno = EPIPE;
551 			fetch_syserr();
552 			return (-1);
553 		}
554 		if (wlen < 0) {
555 			if (errno == EINTR && fetchRestartCalls)
556 				continue;
557 			return (-1);
558 		}
559 		total += wlen;
560 		while (iovcnt > 0 && wlen >= (ssize_t)iov->iov_len) {
561 			wlen -= iov->iov_len;
562 			iov++;
563 			iovcnt--;
564 		}
565 		if (iovcnt > 0) {
566 			iov->iov_len -= wlen;
567 			iov->iov_base = __DECONST(char *, iov->iov_base) + wlen;
568 		}
569 	}
570 	return (total);
571 }
572 
573 
574 /*
575  * Write a line of text to a connection w/ timeout
576  */
577 int
578 fetch_putln(conn_t *conn, const char *str, size_t len)
579 {
580 	struct iovec iov[2];
581 	int ret;
582 
583 	DEBUG(fprintf(stderr, ">>> %s\n", str));
584 	iov[0].iov_base = __DECONST(char *, str);
585 	iov[0].iov_len = len;
586 	iov[1].iov_base = __DECONST(char *, ENDL);
587 	iov[1].iov_len = sizeof(ENDL);
588 	if (len == 0)
589 		ret = fetch_writev(conn, &iov[1], 1);
590 	else
591 		ret = fetch_writev(conn, iov, 2);
592 	if (ret == -1)
593 		return (-1);
594 	return (0);
595 }
596 
597 
598 /*
599  * Close connection
600  */
601 int
602 fetch_close(conn_t *conn)
603 {
604 	int ret;
605 
606 	if (--conn->ref > 0)
607 		return (0);
608 	ret = close(conn->sd);
609 	free(conn->buf);
610 	free(conn);
611 	return (ret);
612 }
613 
614 
615 /*** Directory-related utility functions *************************************/
616 
617 int
618 fetch_add_entry(struct url_ent **p, int *size, int *len,
619     const char *name, struct url_stat *us)
620 {
621 	struct url_ent *tmp;
622 
623 	if (*p == NULL) {
624 		*size = 0;
625 		*len = 0;
626 	}
627 
628 	if (*len >= *size - 1) {
629 		tmp = realloc(*p, (*size * 2 + 1) * sizeof(**p));
630 		if (tmp == NULL) {
631 			errno = ENOMEM;
632 			fetch_syserr();
633 			return (-1);
634 		}
635 		*size = (*size * 2 + 1);
636 		*p = tmp;
637 	}
638 
639 	tmp = *p + *len;
640 	snprintf(tmp->name, PATH_MAX, "%s", name);
641 	memcpy(&tmp->stat, us, sizeof(*us));
642 
643 	(*len)++;
644 	(++tmp)->name[0] = 0;
645 
646 	return (0);
647 }
648 
649 
650 /*** Authentication-related utility functions ********************************/
651 
652 static const char *
653 fetch_read_word(FILE *f)
654 {
655 	static char word[1024];
656 
657 	if (fscanf(f, " %1023s ", word) != 1)
658 		return (NULL);
659 	return (word);
660 }
661 
662 /*
663  * Get authentication data for a URL from .netrc
664  */
665 int
666 fetch_netrc_auth(struct url *url)
667 {
668 	char fn[PATH_MAX];
669 	const char *word;
670 	char *p;
671 	FILE *f;
672 
673 	if ((p = getenv("NETRC")) != NULL) {
674 		if (snprintf(fn, sizeof(fn), "%s", p) >= (int)sizeof(fn)) {
675 			fetch_info("$NETRC specifies a file name "
676 			    "longer than PATH_MAX");
677 			return (-1);
678 		}
679 	} else {
680 		if ((p = getenv("HOME")) != NULL) {
681 			struct passwd *pwd;
682 
683 			if ((pwd = getpwuid(getuid())) == NULL ||
684 			    (p = pwd->pw_dir) == NULL)
685 				return (-1);
686 		}
687 		if (snprintf(fn, sizeof(fn), "%s/.netrc", p) >= (int)sizeof(fn))
688 			return (-1);
689 	}
690 
691 	if ((f = fopen(fn, "r")) == NULL)
692 		return (-1);
693 	while ((word = fetch_read_word(f)) != NULL) {
694 		if (strcmp(word, "default") == 0) {
695 			DEBUG(fetch_info("Using default .netrc settings"));
696 			break;
697 		}
698 		if (strcmp(word, "machine") == 0 &&
699 		    (word = fetch_read_word(f)) != NULL &&
700 		    strcasecmp(word, url->host) == 0) {
701 			DEBUG(fetch_info("Using .netrc settings for %s", word));
702 			break;
703 		}
704 	}
705 	if (word == NULL)
706 		goto ferr;
707 	while ((word = fetch_read_word(f)) != NULL) {
708 		if (strcmp(word, "login") == 0) {
709 			if ((word = fetch_read_word(f)) == NULL)
710 				goto ferr;
711 			if (snprintf(url->user, sizeof(url->user),
712 				"%s", word) > (int)sizeof(url->user)) {
713 				fetch_info("login name in .netrc is too long");
714 				url->user[0] = '\0';
715 			}
716 		} else if (strcmp(word, "password") == 0) {
717 			if ((word = fetch_read_word(f)) == NULL)
718 				goto ferr;
719 			if (snprintf(url->pwd, sizeof(url->pwd),
720 				"%s", word) > (int)sizeof(url->pwd)) {
721 				fetch_info("password in .netrc is too long");
722 				url->pwd[0] = '\0';
723 			}
724 		} else if (strcmp(word, "account") == 0) {
725 			if ((word = fetch_read_word(f)) == NULL)
726 				goto ferr;
727 			/* XXX not supported! */
728 		} else {
729 			break;
730 		}
731 	}
732 	fclose(f);
733 	return (0);
734  ferr:
735 	fclose(f);
736 	return (-1);
737 }
738 
739 /*
740  * The no_proxy environment variable specifies a set of domains for
741  * which the proxy should not be consulted; the contents is a comma-,
742  * or space-separated list of domain names.  A single asterisk will
743  * override all proxy variables and no transactions will be proxied
744  * (for compatability with lynx and curl, see the discussion at
745  * <http://curl.haxx.se/mail/archive_pre_oct_99/0009.html>).
746  */
747 int
748 fetch_no_proxy_match(const char *host)
749 {
750 	const char *no_proxy, *p, *q;
751 	size_t h_len, d_len;
752 
753 	if ((no_proxy = getenv("NO_PROXY")) == NULL &&
754 	    (no_proxy = getenv("no_proxy")) == NULL)
755 		return (0);
756 
757 	/* asterisk matches any hostname */
758 	if (strcmp(no_proxy, "*") == 0)
759 		return (1);
760 
761 	h_len = strlen(host);
762 	p = no_proxy;
763 	do {
764 		/* position p at the beginning of a domain suffix */
765 		while (*p == ',' || isspace((unsigned char)*p))
766 			p++;
767 
768 		/* position q at the first separator character */
769 		for (q = p; *q; ++q)
770 			if (*q == ',' || isspace((unsigned char)*q))
771 				break;
772 
773 		d_len = q - p;
774 		if (d_len > 0 && h_len >= d_len &&
775 		    strncasecmp(host + h_len - d_len,
776 			p, d_len) == 0) {
777 			/* domain name matches */
778 			return (1);
779 		}
780 
781 		p = q + 1;
782 	} while (*q);
783 
784 	return (0);
785 }
786