xref: /freebsd/lib/libfetch/common.c (revision f9218d3d4fd34f082473b3a021c6d4d109fb47cf) 
1 /*-
2  * Copyright (c) 1998 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 	{ EAI_NODATA,	FETCH_RESOLV,	"Host not found" },
58 	{ EAI_AGAIN,	FETCH_TEMP,	"Transient resolver failure" },
59 	{ EAI_FAIL,	FETCH_RESOLV,	"Non-recoverable resolver failure" },
60 	{ EAI_NONAME,	FETCH_RESOLV,	"No address record" },
61 	{ -1,		FETCH_UNKNOWN,	"Unknown resolver error" }
62 };
63 
64 /* End-of-Line */
65 static const char ENDL[2] = "\r\n";
66 
67 
68 /*** Error-reporting functions ***********************************************/
69 
70 /*
71  * Map error code to string
72  */
73 static struct fetcherr *
74 _fetch_finderr(struct fetcherr *p, int e)
75 {
76 	while (p->num != -1 && p->num != e)
77 		p++;
78 	return (p);
79 }
80 
81 /*
82  * Set error code
83  */
84 void
85 _fetch_seterr(struct fetcherr *p, int e)
86 {
87 	p = _fetch_finderr(p, e);
88 	fetchLastErrCode = p->cat;
89 	snprintf(fetchLastErrString, MAXERRSTRING, "%s", p->string);
90 }
91 
92 /*
93  * Set error code according to errno
94  */
95 void
96 _fetch_syserr(void)
97 {
98 	switch (errno) {
99 	case 0:
100 		fetchLastErrCode = FETCH_OK;
101 		break;
102 	case EPERM:
103 	case EACCES:
104 	case EROFS:
105 	case EAUTH:
106 	case ENEEDAUTH:
107 		fetchLastErrCode = FETCH_AUTH;
108 		break;
109 	case ENOENT:
110 	case EISDIR: /* XXX */
111 		fetchLastErrCode = FETCH_UNAVAIL;
112 		break;
113 	case ENOMEM:
114 		fetchLastErrCode = FETCH_MEMORY;
115 		break;
116 	case EBUSY:
117 	case EAGAIN:
118 		fetchLastErrCode = FETCH_TEMP;
119 		break;
120 	case EEXIST:
121 		fetchLastErrCode = FETCH_EXISTS;
122 		break;
123 	case ENOSPC:
124 		fetchLastErrCode = FETCH_FULL;
125 		break;
126 	case EADDRINUSE:
127 	case EADDRNOTAVAIL:
128 	case ENETDOWN:
129 	case ENETUNREACH:
130 	case ENETRESET:
131 	case EHOSTUNREACH:
132 		fetchLastErrCode = FETCH_NETWORK;
133 		break;
134 	case ECONNABORTED:
135 	case ECONNRESET:
136 		fetchLastErrCode = FETCH_ABORT;
137 		break;
138 	case ETIMEDOUT:
139 		fetchLastErrCode = FETCH_TIMEOUT;
140 		break;
141 	case ECONNREFUSED:
142 	case EHOSTDOWN:
143 		fetchLastErrCode = FETCH_DOWN;
144 		break;
145 default:
146 		fetchLastErrCode = FETCH_UNKNOWN;
147 	}
148 	snprintf(fetchLastErrString, MAXERRSTRING, "%s", strerror(errno));
149 }
150 
151 
152 /*
153  * Emit status message
154  */
155 void
156 _fetch_info(const char *fmt, ...)
157 {
158 	va_list ap;
159 
160 	va_start(ap, fmt);
161 	vfprintf(stderr, fmt, ap);
162 	va_end(ap);
163 	fputc('\n', stderr);
164 }
165 
166 
167 /*** Network-related utility functions ***************************************/
168 
169 /*
170  * Return the default port for a scheme
171  */
172 int
173 _fetch_default_port(const char *scheme)
174 {
175 	struct servent *se;
176 
177 	if ((se = getservbyname(scheme, "tcp")) != NULL)
178 		return (ntohs(se->s_port));
179 	if (strcasecmp(scheme, SCHEME_FTP) == 0)
180 		return (FTP_DEFAULT_PORT);
181 	if (strcasecmp(scheme, SCHEME_HTTP) == 0)
182 		return (HTTP_DEFAULT_PORT);
183 	return (0);
184 }
185 
186 /*
187  * Return the default proxy port for a scheme
188  */
189 int
190 _fetch_default_proxy_port(const char *scheme)
191 {
192 	if (strcasecmp(scheme, SCHEME_FTP) == 0)
193 		return (FTP_DEFAULT_PROXY_PORT);
194 	if (strcasecmp(scheme, SCHEME_HTTP) == 0)
195 		return (HTTP_DEFAULT_PROXY_PORT);
196 	return (0);
197 }
198 
199 
200 /*
201  * Create a connection for an existing descriptor.
202  */
203 conn_t *
204 _fetch_reopen(int sd)
205 {
206 	conn_t *conn;
207 
208 	/* allocate and fill connection structure */
209 	if ((conn = calloc(1, sizeof(*conn))) == NULL)
210 		return (NULL);
211 	conn->sd = sd;
212 	++conn->ref;
213 	return (conn);
214 }
215 
216 
217 /*
218  * Bump a connection's reference count.
219  */
220 conn_t *
221 _fetch_ref(conn_t *conn)
222 {
223 
224 	++conn->ref;
225 	return (conn);
226 }
227 
228 
229 /*
230  * Bind a socket to a specific local address
231  */
232 int
233 _fetch_bind(int sd, int af, const char *addr)
234 {
235 	struct addrinfo hints, *res, *res0;
236 	int err;
237 
238 	memset(&hints, 0, sizeof(hints));
239 	hints.ai_family = af;
240 	hints.ai_socktype = SOCK_STREAM;
241 	hints.ai_protocol = 0;
242 	if ((err = getaddrinfo(addr, NULL, &hints, &res0)) != 0)
243 		return (-1);
244 	for (res = res0; res; res = res->ai_next)
245 		if (bind(sd, res->ai_addr, res->ai_addrlen) == 0)
246 			return (0);
247 	return (-1);
248 }
249 
250 
251 /*
252  * Establish a TCP connection to the specified port on the specified host.
253  */
254 conn_t *
255 _fetch_connect(const char *host, int port, int af, int verbose)
256 {
257 	conn_t *conn;
258 	char pbuf[10];
259 	const char *bindaddr;
260 	struct addrinfo hints, *res, *res0;
261 	int sd, err;
262 
263 	DEBUG(fprintf(stderr, "---> %s:%d\n", host, port));
264 
265 	if (verbose)
266 		_fetch_info("looking up %s", host);
267 
268 	/* look up host name and set up socket address structure */
269 	snprintf(pbuf, sizeof(pbuf), "%d", port);
270 	memset(&hints, 0, sizeof(hints));
271 	hints.ai_family = af;
272 	hints.ai_socktype = SOCK_STREAM;
273 	hints.ai_protocol = 0;
274 	if ((err = getaddrinfo(host, pbuf, &hints, &res0)) != 0) {
275 		_netdb_seterr(err);
276 		return (NULL);
277 	}
278 	bindaddr = getenv("FETCH_BIND_ADDRESS");
279 
280 	if (verbose)
281 		_fetch_info("connecting to %s:%d", host, port);
282 
283 	/* try to connect */
284 	for (sd = -1, res = res0; res; sd = -1, res = res->ai_next) {
285 		if ((sd = socket(res->ai_family, res->ai_socktype,
286 			 res->ai_protocol)) == -1)
287 			continue;
288 		if (bindaddr != NULL && *bindaddr != '\0' &&
289 		    _fetch_bind(sd, res->ai_family, bindaddr) != 0) {
290 			_fetch_info("failed to bind to '%s'", bindaddr);
291 			close(sd);
292 			continue;
293 		}
294 		if (connect(sd, res->ai_addr, res->ai_addrlen) == 0)
295 			break;
296 		close(sd);
297 	}
298 	freeaddrinfo(res0);
299 	if (sd == -1) {
300 		_fetch_syserr();
301 		return (NULL);
302 	}
303 
304 	if ((conn = _fetch_reopen(sd)) == NULL) {
305 		_fetch_syserr();
306 		close(sd);
307 	}
308 	return (conn);
309 }
310 
311 
312 /*
313  * Enable SSL on a connection.
314  */
315 int
316 _fetch_ssl(conn_t *conn, int verbose)
317 {
318 
319 #ifdef WITH_SSL
320 	/* Init the SSL library and context */
321 	if (!SSL_library_init()){
322 		fprintf(stderr, "SSL library init failed\n");
323 		return (-1);
324 	}
325 
326 	SSL_load_error_strings();
327 
328 	conn->ssl_meth = SSLv23_client_method();
329 	conn->ssl_ctx = SSL_CTX_new(conn->ssl_meth);
330 	SSL_CTX_set_mode(conn->ssl_ctx, SSL_MODE_AUTO_RETRY);
331 
332 	conn->ssl = SSL_new(conn->ssl_ctx);
333 	if (conn->ssl == NULL){
334 		fprintf(stderr, "SSL context creation failed\n");
335 		return (-1);
336 	}
337 	SSL_set_fd(conn->ssl, conn->sd);
338 	if (SSL_connect(conn->ssl) == -1){
339 		ERR_print_errors_fp(stderr);
340 		return (-1);
341 	}
342 
343 	if (verbose) {
344 		X509_NAME *name;
345 		char *str;
346 
347 		fprintf(stderr, "SSL connection established using %s\n",
348 		    SSL_get_cipher(conn->ssl));
349 		conn->ssl_cert = SSL_get_peer_certificate(conn->ssl);
350 		name = X509_get_subject_name(conn->ssl_cert);
351 		str = X509_NAME_oneline(name, 0, 0);
352 		printf("Certificate subject: %s\n", str);
353 		free(str);
354 		name = X509_get_issuer_name(conn->ssl_cert);
355 		str = X509_NAME_oneline(name, 0, 0);
356 		printf("Certificate issuer: %s\n", str);
357 		free(str);
358 	}
359 
360 	return (0);
361 #else
362 	(void)conn;
363 	(void)verbose;
364 	fprintf(stderr, "SSL support disabled\n");
365 	return (-1);
366 #endif
367 }
368 
369 
370 /*
371  * Read a character from a connection w/ timeout
372  */
373 ssize_t
374 _fetch_read(conn_t *conn, char *buf, size_t len)
375 {
376 	struct timeval now, timeout, wait;
377 	fd_set readfds;
378 	ssize_t rlen, total;
379 	int r;
380 
381 	if (fetchTimeout) {
382 		FD_ZERO(&readfds);
383 		gettimeofday(&timeout, NULL);
384 		timeout.tv_sec += fetchTimeout;
385 	}
386 
387 	total = 0;
388 	while (len > 0) {
389 		while (fetchTimeout && !FD_ISSET(conn->sd, &readfds)) {
390 			FD_SET(conn->sd, &readfds);
391 			gettimeofday(&now, NULL);
392 			wait.tv_sec = timeout.tv_sec - now.tv_sec;
393 			wait.tv_usec = timeout.tv_usec - now.tv_usec;
394 			if (wait.tv_usec < 0) {
395 				wait.tv_usec += 1000000;
396 				wait.tv_sec--;
397 			}
398 			if (wait.tv_sec < 0) {
399 				errno = ETIMEDOUT;
400 				_fetch_syserr();
401 				return (-1);
402 			}
403 			errno = 0;
404 			r = select(conn->sd + 1, &readfds, NULL, NULL, &wait);
405 			if (r == -1) {
406 				if (errno == EINTR && fetchRestartCalls)
407 					continue;
408 				_fetch_syserr();
409 				return (-1);
410 			}
411 		}
412 #ifdef WITH_SSL
413 		if (conn->ssl != NULL)
414 			rlen = SSL_read(conn->ssl, buf, len);
415 		else
416 #endif
417 			rlen = read(conn->sd, buf, len);
418 		if (rlen == 0)
419 			break;
420 		if (rlen < 0) {
421 			if (errno == EINTR && fetchRestartCalls)
422 				continue;
423 			return (-1);
424 		}
425 		len -= rlen;
426 		buf += rlen;
427 		total += rlen;
428 	}
429 	return (total);
430 }
431 
432 
433 /*
434  * Read a line of text from a connection w/ timeout
435  */
436 #define MIN_BUF_SIZE 1024
437 
438 int
439 _fetch_getln(conn_t *conn)
440 {
441 	char *tmp;
442 	size_t tmpsize;
443 	ssize_t len;
444 	char c;
445 
446 	if (conn->buf == NULL) {
447 		if ((conn->buf = malloc(MIN_BUF_SIZE)) == NULL) {
448 			errno = ENOMEM;
449 			return (-1);
450 		}
451 		conn->bufsize = MIN_BUF_SIZE;
452 	}
453 
454 	conn->buf[0] = '\0';
455 	conn->buflen = 0;
456 
457 	do {
458 		len = _fetch_read(conn, &c, 1);
459 		if (len == -1)
460 			return (-1);
461 		if (len == 0)
462 			break;
463 		conn->buf[conn->buflen++] = c;
464 		if (conn->buflen == conn->bufsize) {
465 			tmp = conn->buf;
466 			tmpsize = conn->bufsize * 2 + 1;
467 			if ((tmp = realloc(tmp, tmpsize)) == NULL) {
468 				errno = ENOMEM;
469 				return (-1);
470 			}
471 			conn->buf = tmp;
472 			conn->bufsize = tmpsize;
473 		}
474 	} while (c != '\n');
475 
476 	conn->buf[conn->buflen] = '\0';
477 	DEBUG(fprintf(stderr, "<<< %s", conn->buf));
478 	return (0);
479 }
480 
481 
482 /*
483  * Write to a connection w/ timeout
484  */
485 ssize_t
486 _fetch_write(conn_t *conn, const char *buf, size_t len)
487 {
488 	struct iovec iov;
489 
490 	iov.iov_base = __DECONST(char *, buf);
491 	iov.iov_len = len;
492 	return _fetch_writev(conn, &iov, 1);
493 }
494 
495 /*
496  * Write a vector to a connection w/ timeout
497  * Note: can modify the iovec.
498  */
499 ssize_t
500 _fetch_writev(conn_t *conn, struct iovec *iov, int iovcnt)
501 {
502 	struct timeval now, timeout, wait;
503 	fd_set writefds;
504 	ssize_t wlen, total;
505 	int r;
506 
507 	if (fetchTimeout) {
508 		FD_ZERO(&writefds);
509 		gettimeofday(&timeout, NULL);
510 		timeout.tv_sec += fetchTimeout;
511 	}
512 
513 	total = 0;
514 	while (iovcnt > 0) {
515 		while (fetchTimeout && !FD_ISSET(conn->sd, &writefds)) {
516 			FD_SET(conn->sd, &writefds);
517 			gettimeofday(&now, NULL);
518 			wait.tv_sec = timeout.tv_sec - now.tv_sec;
519 			wait.tv_usec = timeout.tv_usec - now.tv_usec;
520 			if (wait.tv_usec < 0) {
521 				wait.tv_usec += 1000000;
522 				wait.tv_sec--;
523 			}
524 			if (wait.tv_sec < 0) {
525 				errno = ETIMEDOUT;
526 				_fetch_syserr();
527 				return (-1);
528 			}
529 			errno = 0;
530 			r = select(conn->sd + 1, NULL, &writefds, NULL, &wait);
531 			if (r == -1) {
532 				if (errno == EINTR && fetchRestartCalls)
533 					continue;
534 				return (-1);
535 			}
536 		}
537 		errno = 0;
538 #ifdef WITH_SSL
539 		if (conn->ssl != NULL)
540 			wlen = SSL_write(conn->ssl,
541 			    iov->iov_base, iov->iov_len);
542 		else
543 #endif
544 			wlen = writev(conn->sd, iov, iovcnt);
545 		if (wlen == 0) {
546 			/* we consider a short write a failure */
547 			errno = EPIPE;
548 			_fetch_syserr();
549 			return (-1);
550 		}
551 		if (wlen < 0) {
552 			if (errno == EINTR && fetchRestartCalls)
553 				continue;
554 			return (-1);
555 		}
556 		total += wlen;
557 		while (iovcnt > 0 && wlen >= (ssize_t)iov->iov_len) {
558 			wlen -= iov->iov_len;
559 			iov++;
560 			iovcnt--;
561 		}
562 		if (iovcnt > 0) {
563 			iov->iov_len -= wlen;
564 			iov->iov_base = __DECONST(char *, iov->iov_base) + wlen;
565 		}
566 	}
567 	return (total);
568 }
569 
570 
571 /*
572  * Write a line of text to a connection w/ timeout
573  */
574 int
575 _fetch_putln(conn_t *conn, const char *str, size_t len)
576 {
577 	struct iovec iov[2];
578 	int ret;
579 
580 	DEBUG(fprintf(stderr, ">>> %s\n", str));
581 	iov[0].iov_base = __DECONST(char *, str);
582 	iov[0].iov_len = len;
583 	iov[1].iov_base = __DECONST(char *, ENDL);
584 	iov[1].iov_len = sizeof(ENDL);
585 	if (len == 0)
586 		ret = _fetch_writev(conn, &iov[1], 1);
587 	else
588 		ret = _fetch_writev(conn, iov, 2);
589 	if (ret == -1)
590 		return (-1);
591 	return (0);
592 }
593 
594 
595 /*
596  * Close connection
597  */
598 int
599 _fetch_close(conn_t *conn)
600 {
601 	int ret;
602 
603 	if (--conn->ref > 0)
604 		return (0);
605 	ret = close(conn->sd);
606 	free(conn);
607 	return (ret);
608 }
609 
610 
611 /*** Directory-related utility functions *************************************/
612 
613 int
614 _fetch_add_entry(struct url_ent **p, int *size, int *len,
615     const char *name, struct url_stat *us)
616 {
617 	struct url_ent *tmp;
618 
619 	if (*p == NULL) {
620 		*size = 0;
621 		*len = 0;
622 	}
623 
624 	if (*len >= *size - 1) {
625 		tmp = realloc(*p, (*size * 2 + 1) * sizeof(**p));
626 		if (tmp == NULL) {
627 			errno = ENOMEM;
628 			_fetch_syserr();
629 			return (-1);
630 		}
631 		*size = (*size * 2 + 1);
632 		*p = tmp;
633 	}
634 
635 	tmp = *p + *len;
636 	snprintf(tmp->name, PATH_MAX, "%s", name);
637 	bcopy(us, &tmp->stat, sizeof(*us));
638 
639 	(*len)++;
640 	(++tmp)->name[0] = 0;
641 
642 	return (0);
643 }
644 
645 
646 /*** Authentication-related utility functions ********************************/
647 
648 static const char *
649 _fetch_read_word(FILE *f)
650 {
651 	static char word[1024];
652 
653 	if (fscanf(f, " %1024s ", word) != 1)
654 		return (NULL);
655 	return (word);
656 }
657 
658 /*
659  * Get authentication data for a URL from .netrc
660  */
661 int
662 _fetch_netrc_auth(struct url *url)
663 {
664 	char fn[PATH_MAX];
665 	const char *word;
666 	char *p;
667 	FILE *f;
668 
669 	if ((p = getenv("NETRC")) != NULL) {
670 		if (snprintf(fn, sizeof(fn), "%s", p) >= (int)sizeof(fn)) {
671 			_fetch_info("$NETRC specifies a file name "
672 			    "longer than PATH_MAX");
673 			return (-1);
674 		}
675 	} else {
676 		if ((p = getenv("HOME")) != NULL) {
677 			struct passwd *pwd;
678 
679 			if ((pwd = getpwuid(getuid())) == NULL ||
680 			    (p = pwd->pw_dir) == NULL)
681 				return (-1);
682 		}
683 		if (snprintf(fn, sizeof(fn), "%s/.netrc", p) >= (int)sizeof(fn))
684 			return (-1);
685 	}
686 
687 	if ((f = fopen(fn, "r")) == NULL)
688 		return (-1);
689 	while ((word = _fetch_read_word(f)) != NULL) {
690 		if (strcmp(word, "default") == 0) {
691 			DEBUG(_fetch_info("Using default .netrc settings"));
692 			break;
693 		}
694 		if (strcmp(word, "machine") == 0 &&
695 		    (word = _fetch_read_word(f)) != NULL &&
696 		    strcasecmp(word, url->host) == 0) {
697 			DEBUG(_fetch_info("Using .netrc settings for %s", word));
698 			break;
699 		}
700 	}
701 	if (word == NULL)
702 		goto ferr;
703 	while ((word = _fetch_read_word(f)) != NULL) {
704 		if (strcmp(word, "login") == 0) {
705 			if ((word = _fetch_read_word(f)) == NULL)
706 				goto ferr;
707 			if (snprintf(url->user, sizeof(url->user),
708 				"%s", word) > (int)sizeof(url->user)) {
709 				_fetch_info("login name in .netrc is too long");
710 				url->user[0] = '\0';
711 			}
712 		} else if (strcmp(word, "password") == 0) {
713 			if ((word = _fetch_read_word(f)) == NULL)
714 				goto ferr;
715 			if (snprintf(url->pwd, sizeof(url->pwd),
716 				"%s", word) > (int)sizeof(url->pwd)) {
717 				_fetch_info("password in .netrc is too long");
718 				url->pwd[0] = '\0';
719 			}
720 		} else if (strcmp(word, "account") == 0) {
721 			if ((word = _fetch_read_word(f)) == NULL)
722 				goto ferr;
723 			/* XXX not supported! */
724 		} else {
725 			break;
726 		}
727 	}
728 	fclose(f);
729 	return (0);
730  ferr:
731 	fclose(f);
732 	return (-1);
733 }
734