xref: /freebsd/lib/libfetch/common.c (revision 282a3889ebf826db9839be296ff1dd903f6d6d6e) 
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 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/socket.h>
34 #include <sys/time.h>
35 #include <sys/uio.h>
36 #include <netinet/in.h>
37 
38 #include <errno.h>
39 #include <netdb.h>
40 #include <pwd.h>
41 #include <stdarg.h>
42 #include <stdlib.h>
43 #include <stdio.h>
44 #include <string.h>
45 #include <unistd.h>
46 
47 #include "fetch.h"
48 #include "common.h"
49 
50 
51 /*** Local data **************************************************************/
52 
53 /*
54  * Error messages for resolver errors
55  */
56 static struct fetcherr _netdb_errlist[] = {
57 #ifdef EAI_NODATA
58 	{ EAI_NODATA,	FETCH_RESOLV,	"Host not found" },
59 #endif
60 	{ EAI_AGAIN,	FETCH_TEMP,	"Transient resolver failure" },
61 	{ EAI_FAIL,	FETCH_RESOLV,	"Non-recoverable resolver failure" },
62 	{ EAI_NONAME,	FETCH_RESOLV,	"No address record" },
63 	{ -1,		FETCH_UNKNOWN,	"Unknown resolver error" }
64 };
65 
66 /* End-of-Line */
67 static const char ENDL[2] = "\r\n";
68 
69 
70 /*** Error-reporting functions ***********************************************/
71 
72 /*
73  * Map error code to string
74  */
75 static struct fetcherr *
76 _fetch_finderr(struct fetcherr *p, int e)
77 {
78 	while (p->num != -1 && p->num != e)
79 		p++;
80 	return (p);
81 }
82 
83 /*
84  * Set error code
85  */
86 void
87 _fetch_seterr(struct fetcherr *p, int e)
88 {
89 	p = _fetch_finderr(p, e);
90 	fetchLastErrCode = p->cat;
91 	snprintf(fetchLastErrString, MAXERRSTRING, "%s", p->string);
92 }
93 
94 /*
95  * Set error code according to errno
96  */
97 void
98 _fetch_syserr(void)
99 {
100 	switch (errno) {
101 	case 0:
102 		fetchLastErrCode = FETCH_OK;
103 		break;
104 	case EPERM:
105 	case EACCES:
106 	case EROFS:
107 	case EAUTH:
108 	case ENEEDAUTH:
109 		fetchLastErrCode = FETCH_AUTH;
110 		break;
111 	case ENOENT:
112 	case EISDIR: /* XXX */
113 		fetchLastErrCode = FETCH_UNAVAIL;
114 		break;
115 	case ENOMEM:
116 		fetchLastErrCode = FETCH_MEMORY;
117 		break;
118 	case EBUSY:
119 	case EAGAIN:
120 		fetchLastErrCode = FETCH_TEMP;
121 		break;
122 	case EEXIST:
123 		fetchLastErrCode = FETCH_EXISTS;
124 		break;
125 	case ENOSPC:
126 		fetchLastErrCode = FETCH_FULL;
127 		break;
128 	case EADDRINUSE:
129 	case EADDRNOTAVAIL:
130 	case ENETDOWN:
131 	case ENETUNREACH:
132 	case ENETRESET:
133 	case EHOSTUNREACH:
134 		fetchLastErrCode = FETCH_NETWORK;
135 		break;
136 	case ECONNABORTED:
137 	case ECONNRESET:
138 		fetchLastErrCode = FETCH_ABORT;
139 		break;
140 	case ETIMEDOUT:
141 		fetchLastErrCode = FETCH_TIMEOUT;
142 		break;
143 	case ECONNREFUSED:
144 	case EHOSTDOWN:
145 		fetchLastErrCode = FETCH_DOWN;
146 		break;
147 default:
148 		fetchLastErrCode = FETCH_UNKNOWN;
149 	}
150 	snprintf(fetchLastErrString, MAXERRSTRING, "%s", strerror(errno));
151 }
152 
153 
154 /*
155  * Emit status message
156  */
157 void
158 _fetch_info(const char *fmt, ...)
159 {
160 	va_list ap;
161 
162 	va_start(ap, fmt);
163 	vfprintf(stderr, fmt, ap);
164 	va_end(ap);
165 	fputc('\n', stderr);
166 }
167 
168 
169 /*** Network-related utility functions ***************************************/
170 
171 /*
172  * Return the default port for a scheme
173  */
174 int
175 _fetch_default_port(const char *scheme)
176 {
177 	struct servent *se;
178 
179 	if ((se = getservbyname(scheme, "tcp")) != NULL)
180 		return (ntohs(se->s_port));
181 	if (strcasecmp(scheme, SCHEME_FTP) == 0)
182 		return (FTP_DEFAULT_PORT);
183 	if (strcasecmp(scheme, SCHEME_HTTP) == 0)
184 		return (HTTP_DEFAULT_PORT);
185 	return (0);
186 }
187 
188 /*
189  * Return the default proxy port for a scheme
190  */
191 int
192 _fetch_default_proxy_port(const char *scheme)
193 {
194 	if (strcasecmp(scheme, SCHEME_FTP) == 0)
195 		return (FTP_DEFAULT_PROXY_PORT);
196 	if (strcasecmp(scheme, SCHEME_HTTP) == 0)
197 		return (HTTP_DEFAULT_PROXY_PORT);
198 	return (0);
199 }
200 
201 
202 /*
203  * Create a connection for an existing descriptor.
204  */
205 conn_t *
206 _fetch_reopen(int sd)
207 {
208 	conn_t *conn;
209 
210 	/* allocate and fill connection structure */
211 	if ((conn = calloc(1, sizeof(*conn))) == NULL)
212 		return (NULL);
213 	conn->sd = sd;
214 	++conn->ref;
215 	return (conn);
216 }
217 
218 
219 /*
220  * Bump a connection's reference count.
221  */
222 conn_t *
223 _fetch_ref(conn_t *conn)
224 {
225 
226 	++conn->ref;
227 	return (conn);
228 }
229 
230 
231 /*
232  * Bind a socket to a specific local address
233  */
234 int
235 _fetch_bind(int sd, int af, const char *addr)
236 {
237 	struct addrinfo hints, *res, *res0;
238 	int err;
239 
240 	memset(&hints, 0, sizeof(hints));
241 	hints.ai_family = af;
242 	hints.ai_socktype = SOCK_STREAM;
243 	hints.ai_protocol = 0;
244 	if ((err = getaddrinfo(addr, NULL, &hints, &res0)) != 0)
245 		return (-1);
246 	for (res = res0; res; res = res->ai_next)
247 		if (bind(sd, res->ai_addr, res->ai_addrlen) == 0)
248 			return (0);
249 	return (-1);
250 }
251 
252 
253 /*
254  * Establish a TCP connection to the specified port on the specified host.
255  */
256 conn_t *
257 _fetch_connect(const char *host, int port, int af, int verbose)
258 {
259 	conn_t *conn;
260 	char pbuf[10];
261 	const char *bindaddr;
262 	struct addrinfo hints, *res, *res0;
263 	int sd, err;
264 
265 	DEBUG(fprintf(stderr, "---> %s:%d\n", host, port));
266 
267 	if (verbose)
268 		_fetch_info("looking up %s", host);
269 
270 	/* look up host name and set up socket address structure */
271 	snprintf(pbuf, sizeof(pbuf), "%d", port);
272 	memset(&hints, 0, sizeof(hints));
273 	hints.ai_family = af;
274 	hints.ai_socktype = SOCK_STREAM;
275 	hints.ai_protocol = 0;
276 	if ((err = getaddrinfo(host, pbuf, &hints, &res0)) != 0) {
277 		_netdb_seterr(err);
278 		return (NULL);
279 	}
280 	bindaddr = getenv("FETCH_BIND_ADDRESS");
281 
282 	if (verbose)
283 		_fetch_info("connecting to %s:%d", host, port);
284 
285 	/* try to connect */
286 	for (sd = -1, res = res0; res; sd = -1, res = res->ai_next) {
287 		if ((sd = socket(res->ai_family, res->ai_socktype,
288 			 res->ai_protocol)) == -1)
289 			continue;
290 		if (bindaddr != NULL && *bindaddr != '\0' &&
291 		    _fetch_bind(sd, res->ai_family, bindaddr) != 0) {
292 			_fetch_info("failed to bind to '%s'", bindaddr);
293 			close(sd);
294 			continue;
295 		}
296 		if (connect(sd, res->ai_addr, res->ai_addrlen) == 0)
297 			break;
298 		close(sd);
299 	}
300 	freeaddrinfo(res0);
301 	if (sd == -1) {
302 		_fetch_syserr();
303 		return (NULL);
304 	}
305 
306 	if ((conn = _fetch_reopen(sd)) == NULL) {
307 		_fetch_syserr();
308 		close(sd);
309 	}
310 	return (conn);
311 }
312 
313 
314 /*
315  * Enable SSL on a connection.
316  */
317 int
318 _fetch_ssl(conn_t *conn, int verbose)
319 {
320 
321 #ifdef WITH_SSL
322 	/* Init the SSL library and context */
323 	if (!SSL_library_init()){
324 		fprintf(stderr, "SSL library init failed\n");
325 		return (-1);
326 	}
327 
328 	SSL_load_error_strings();
329 
330 	conn->ssl_meth = SSLv23_client_method();
331 	conn->ssl_ctx = SSL_CTX_new(conn->ssl_meth);
332 	SSL_CTX_set_mode(conn->ssl_ctx, SSL_MODE_AUTO_RETRY);
333 
334 	conn->ssl = SSL_new(conn->ssl_ctx);
335 	if (conn->ssl == NULL){
336 		fprintf(stderr, "SSL context creation failed\n");
337 		return (-1);
338 	}
339 	SSL_set_fd(conn->ssl, conn->sd);
340 	if (SSL_connect(conn->ssl) == -1){
341 		ERR_print_errors_fp(stderr);
342 		return (-1);
343 	}
344 
345 	if (verbose) {
346 		X509_NAME *name;
347 		char *str;
348 
349 		fprintf(stderr, "SSL connection established using %s\n",
350 		    SSL_get_cipher(conn->ssl));
351 		conn->ssl_cert = SSL_get_peer_certificate(conn->ssl);
352 		name = X509_get_subject_name(conn->ssl_cert);
353 		str = X509_NAME_oneline(name, 0, 0);
354 		printf("Certificate subject: %s\n", str);
355 		free(str);
356 		name = X509_get_issuer_name(conn->ssl_cert);
357 		str = X509_NAME_oneline(name, 0, 0);
358 		printf("Certificate issuer: %s\n", str);
359 		free(str);
360 	}
361 
362 	return (0);
363 #else
364 	(void)conn;
365 	(void)verbose;
366 	fprintf(stderr, "SSL support disabled\n");
367 	return (-1);
368 #endif
369 }
370 
371 
372 /*
373  * Read a character from a connection w/ timeout
374  */
375 ssize_t
376 _fetch_read(conn_t *conn, char *buf, size_t len)
377 {
378 	struct timeval now, timeout, wait;
379 	fd_set readfds;
380 	ssize_t rlen, total;
381 	int r;
382 
383 	if (fetchTimeout) {
384 		FD_ZERO(&readfds);
385 		gettimeofday(&timeout, NULL);
386 		timeout.tv_sec += fetchTimeout;
387 	}
388 
389 	total = 0;
390 	while (len > 0) {
391 		while (fetchTimeout && !FD_ISSET(conn->sd, &readfds)) {
392 			FD_SET(conn->sd, &readfds);
393 			gettimeofday(&now, NULL);
394 			wait.tv_sec = timeout.tv_sec - now.tv_sec;
395 			wait.tv_usec = timeout.tv_usec - now.tv_usec;
396 			if (wait.tv_usec < 0) {
397 				wait.tv_usec += 1000000;
398 				wait.tv_sec--;
399 			}
400 			if (wait.tv_sec < 0) {
401 				errno = ETIMEDOUT;
402 				_fetch_syserr();
403 				return (-1);
404 			}
405 			errno = 0;
406 			r = select(conn->sd + 1, &readfds, NULL, NULL, &wait);
407 			if (r == -1) {
408 				if (errno == EINTR && fetchRestartCalls)
409 					continue;
410 				_fetch_syserr();
411 				return (-1);
412 			}
413 		}
414 #ifdef WITH_SSL
415 		if (conn->ssl != NULL)
416 			rlen = SSL_read(conn->ssl, buf, len);
417 		else
418 #endif
419 			rlen = read(conn->sd, buf, len);
420 		if (rlen == 0)
421 			break;
422 		if (rlen < 0) {
423 			if (errno == EINTR && fetchRestartCalls)
424 				continue;
425 			return (-1);
426 		}
427 		len -= rlen;
428 		buf += rlen;
429 		total += rlen;
430 	}
431 	return (total);
432 }
433 
434 
435 /*
436  * Read a line of text from a connection w/ timeout
437  */
438 #define MIN_BUF_SIZE 1024
439 
440 int
441 _fetch_getln(conn_t *conn)
442 {
443 	char *tmp;
444 	size_t tmpsize;
445 	ssize_t len;
446 	char c;
447 
448 	if (conn->buf == NULL) {
449 		if ((conn->buf = malloc(MIN_BUF_SIZE)) == NULL) {
450 			errno = ENOMEM;
451 			return (-1);
452 		}
453 		conn->bufsize = MIN_BUF_SIZE;
454 	}
455 
456 	conn->buf[0] = '\0';
457 	conn->buflen = 0;
458 
459 	do {
460 		len = _fetch_read(conn, &c, 1);
461 		if (len == -1)
462 			return (-1);
463 		if (len == 0)
464 			break;
465 		conn->buf[conn->buflen++] = c;
466 		if (conn->buflen == conn->bufsize) {
467 			tmp = conn->buf;
468 			tmpsize = conn->bufsize * 2 + 1;
469 			if ((tmp = realloc(tmp, tmpsize)) == NULL) {
470 				errno = ENOMEM;
471 				return (-1);
472 			}
473 			conn->buf = tmp;
474 			conn->bufsize = tmpsize;
475 		}
476 	} while (c != '\n');
477 
478 	conn->buf[conn->buflen] = '\0';
479 	DEBUG(fprintf(stderr, "<<< %s", conn->buf));
480 	return (0);
481 }
482 
483 
484 /*
485  * Write to a connection w/ timeout
486  */
487 ssize_t
488 _fetch_write(conn_t *conn, const char *buf, size_t len)
489 {
490 	struct iovec iov;
491 
492 	iov.iov_base = __DECONST(char *, buf);
493 	iov.iov_len = len;
494 	return _fetch_writev(conn, &iov, 1);
495 }
496 
497 /*
498  * Write a vector to a connection w/ timeout
499  * Note: can modify the iovec.
500  */
501 ssize_t
502 _fetch_writev(conn_t *conn, struct iovec *iov, int iovcnt)
503 {
504 	struct timeval now, timeout, wait;
505 	fd_set writefds;
506 	ssize_t wlen, total;
507 	int r;
508 
509 	if (fetchTimeout) {
510 		FD_ZERO(&writefds);
511 		gettimeofday(&timeout, NULL);
512 		timeout.tv_sec += fetchTimeout;
513 	}
514 
515 	total = 0;
516 	while (iovcnt > 0) {
517 		while (fetchTimeout && !FD_ISSET(conn->sd, &writefds)) {
518 			FD_SET(conn->sd, &writefds);
519 			gettimeofday(&now, NULL);
520 			wait.tv_sec = timeout.tv_sec - now.tv_sec;
521 			wait.tv_usec = timeout.tv_usec - now.tv_usec;
522 			if (wait.tv_usec < 0) {
523 				wait.tv_usec += 1000000;
524 				wait.tv_sec--;
525 			}
526 			if (wait.tv_sec < 0) {
527 				errno = ETIMEDOUT;
528 				_fetch_syserr();
529 				return (-1);
530 			}
531 			errno = 0;
532 			r = select(conn->sd + 1, NULL, &writefds, NULL, &wait);
533 			if (r == -1) {
534 				if (errno == EINTR && fetchRestartCalls)
535 					continue;
536 				return (-1);
537 			}
538 		}
539 		errno = 0;
540 #ifdef WITH_SSL
541 		if (conn->ssl != NULL)
542 			wlen = SSL_write(conn->ssl,
543 			    iov->iov_base, iov->iov_len);
544 		else
545 #endif
546 			wlen = writev(conn->sd, iov, iovcnt);
547 		if (wlen == 0) {
548 			/* we consider a short write a failure */
549 			errno = EPIPE;
550 			_fetch_syserr();
551 			return (-1);
552 		}
553 		if (wlen < 0) {
554 			if (errno == EINTR && fetchRestartCalls)
555 				continue;
556 			return (-1);
557 		}
558 		total += wlen;
559 		while (iovcnt > 0 && wlen >= (ssize_t)iov->iov_len) {
560 			wlen -= iov->iov_len;
561 			iov++;
562 			iovcnt--;
563 		}
564 		if (iovcnt > 0) {
565 			iov->iov_len -= wlen;
566 			iov->iov_base = __DECONST(char *, iov->iov_base) + wlen;
567 		}
568 	}
569 	return (total);
570 }
571 
572 
573 /*
574  * Write a line of text to a connection w/ timeout
575  */
576 int
577 _fetch_putln(conn_t *conn, const char *str, size_t len)
578 {
579 	struct iovec iov[2];
580 	int ret;
581 
582 	DEBUG(fprintf(stderr, ">>> %s\n", str));
583 	iov[0].iov_base = __DECONST(char *, str);
584 	iov[0].iov_len = len;
585 	iov[1].iov_base = __DECONST(char *, ENDL);
586 	iov[1].iov_len = sizeof(ENDL);
587 	if (len == 0)
588 		ret = _fetch_writev(conn, &iov[1], 1);
589 	else
590 		ret = _fetch_writev(conn, iov, 2);
591 	if (ret == -1)
592 		return (-1);
593 	return (0);
594 }
595 
596 
597 /*
598  * Close connection
599  */
600 int
601 _fetch_close(conn_t *conn)
602 {
603 	int ret;
604 
605 	if (--conn->ref > 0)
606 		return (0);
607 	ret = close(conn->sd);
608 	free(conn->buf);
609 	free(conn);
610 	return (ret);
611 }
612 
613 
614 /*** Directory-related utility functions *************************************/
615 
616 int
617 _fetch_add_entry(struct url_ent **p, int *size, int *len,
618     const char *name, struct url_stat *us)
619 {
620 	struct url_ent *tmp;
621 
622 	if (*p == NULL) {
623 		*size = 0;
624 		*len = 0;
625 	}
626 
627 	if (*len >= *size - 1) {
628 		tmp = realloc(*p, (*size * 2 + 1) * sizeof(**p));
629 		if (tmp == NULL) {
630 			errno = ENOMEM;
631 			_fetch_syserr();
632 			return (-1);
633 		}
634 		*size = (*size * 2 + 1);
635 		*p = tmp;
636 	}
637 
638 	tmp = *p + *len;
639 	snprintf(tmp->name, PATH_MAX, "%s", name);
640 	bcopy(us, &tmp->stat, sizeof(*us));
641 
642 	(*len)++;
643 	(++tmp)->name[0] = 0;
644 
645 	return (0);
646 }
647 
648 
649 /*** Authentication-related utility functions ********************************/
650 
651 static const char *
652 _fetch_read_word(FILE *f)
653 {
654 	static char word[1024];
655 
656 	if (fscanf(f, " %1024s ", word) != 1)
657 		return (NULL);
658 	return (word);
659 }
660 
661 /*
662  * Get authentication data for a URL from .netrc
663  */
664 int
665 _fetch_netrc_auth(struct url *url)
666 {
667 	char fn[PATH_MAX];
668 	const char *word;
669 	char *p;
670 	FILE *f;
671 
672 	if ((p = getenv("NETRC")) != NULL) {
673 		if (snprintf(fn, sizeof(fn), "%s", p) >= (int)sizeof(fn)) {
674 			_fetch_info("$NETRC specifies a file name "
675 			    "longer than PATH_MAX");
676 			return (-1);
677 		}
678 	} else {
679 		if ((p = getenv("HOME")) != NULL) {
680 			struct passwd *pwd;
681 
682 			if ((pwd = getpwuid(getuid())) == NULL ||
683 			    (p = pwd->pw_dir) == NULL)
684 				return (-1);
685 		}
686 		if (snprintf(fn, sizeof(fn), "%s/.netrc", p) >= (int)sizeof(fn))
687 			return (-1);
688 	}
689 
690 	if ((f = fopen(fn, "r")) == NULL)
691 		return (-1);
692 	while ((word = _fetch_read_word(f)) != NULL) {
693 		if (strcmp(word, "default") == 0) {
694 			DEBUG(_fetch_info("Using default .netrc settings"));
695 			break;
696 		}
697 		if (strcmp(word, "machine") == 0 &&
698 		    (word = _fetch_read_word(f)) != NULL &&
699 		    strcasecmp(word, url->host) == 0) {
700 			DEBUG(_fetch_info("Using .netrc settings for %s", word));
701 			break;
702 		}
703 	}
704 	if (word == NULL)
705 		goto ferr;
706 	while ((word = _fetch_read_word(f)) != NULL) {
707 		if (strcmp(word, "login") == 0) {
708 			if ((word = _fetch_read_word(f)) == NULL)
709 				goto ferr;
710 			if (snprintf(url->user, sizeof(url->user),
711 				"%s", word) > (int)sizeof(url->user)) {
712 				_fetch_info("login name in .netrc is too long");
713 				url->user[0] = '\0';
714 			}
715 		} else if (strcmp(word, "password") == 0) {
716 			if ((word = _fetch_read_word(f)) == NULL)
717 				goto ferr;
718 			if (snprintf(url->pwd, sizeof(url->pwd),
719 				"%s", word) > (int)sizeof(url->pwd)) {
720 				_fetch_info("password in .netrc is too long");
721 				url->pwd[0] = '\0';
722 			}
723 		} else if (strcmp(word, "account") == 0) {
724 			if ((word = _fetch_read_word(f)) == NULL)
725 				goto ferr;
726 			/* XXX not supported! */
727 		} else {
728 			break;
729 		}
730 	}
731 	fclose(f);
732 	return (0);
733  ferr:
734 	fclose(f);
735 	return (-1);
736 }
737