xref: /freebsd/lib/libfetch/common.c (revision 4b2eaea43fec8e8792be611dea204071a10b655a) 
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  * Establish a TCP connection to the specified port on the specified host.
231  */
232 conn_t *
233 _fetch_connect(const char *host, int port, int af, int verbose)
234 {
235 	conn_t *conn;
236 	char pbuf[10];
237 	struct addrinfo hints, *res, *res0;
238 	int sd, err;
239 
240 	DEBUG(fprintf(stderr, "---> %s:%d\n", host, port));
241 
242 	if (verbose)
243 		_fetch_info("looking up %s", host);
244 
245 	/* look up host name and set up socket address structure */
246 	snprintf(pbuf, sizeof(pbuf), "%d", port);
247 	memset(&hints, 0, sizeof(hints));
248 	hints.ai_family = af;
249 	hints.ai_socktype = SOCK_STREAM;
250 	hints.ai_protocol = 0;
251 	if ((err = getaddrinfo(host, pbuf, &hints, &res0)) != 0) {
252 		_netdb_seterr(err);
253 		return (NULL);
254 	}
255 
256 	if (verbose)
257 		_fetch_info("connecting to %s:%d", host, port);
258 
259 	/* try to connect */
260 	for (sd = -1, res = res0; res; res = res->ai_next) {
261 		if ((sd = socket(res->ai_family, res->ai_socktype,
262 			 res->ai_protocol)) == -1)
263 			continue;
264 		if (connect(sd, res->ai_addr, res->ai_addrlen) != -1)
265 			break;
266 		close(sd);
267 		sd = -1;
268 	}
269 	freeaddrinfo(res0);
270 	if (sd == -1) {
271 		_fetch_syserr();
272 		return (NULL);
273 	}
274 
275 	if ((conn = _fetch_reopen(sd)) == NULL) {
276 		_fetch_syserr();
277 		close(sd);
278 	}
279 	return (conn);
280 }
281 
282 
283 /*
284  * Enable SSL on a connection.
285  */
286 int
287 _fetch_ssl(conn_t *conn, int verbose)
288 {
289 
290 #ifdef WITH_SSL
291 	/* Init the SSL library and context */
292 	if (!SSL_library_init()){
293 		fprintf(stderr, "SSL library init failed\n");
294 		return (-1);
295 	}
296 
297 	SSL_load_error_strings();
298 
299 	conn->ssl_meth = SSLv23_client_method();
300 	conn->ssl_ctx = SSL_CTX_new(conn->ssl_meth);
301 	SSL_CTX_set_mode(conn->ssl_ctx, SSL_MODE_AUTO_RETRY);
302 
303 	conn->ssl = SSL_new(conn->ssl_ctx);
304 	if (conn->ssl == NULL){
305 		fprintf(stderr, "SSL context creation failed\n");
306 		return (-1);
307 	}
308 	SSL_set_fd(conn->ssl, conn->sd);
309 	if (SSL_connect(conn->ssl) == -1){
310 		ERR_print_errors_fp(stderr);
311 		return (-1);
312 	}
313 
314 	if (verbose) {
315 		X509_NAME *name;
316 		char *str;
317 
318 		fprintf(stderr, "SSL connection established using %s\n",
319 		    SSL_get_cipher(conn->ssl));
320 		conn->ssl_cert = SSL_get_peer_certificate(conn->ssl);
321 		name = X509_get_subject_name(conn->ssl_cert);
322 		str = X509_NAME_oneline(name, 0, 0);
323 		printf("Certificate subject: %s\n", str);
324 		free(str);
325 		name = X509_get_issuer_name(conn->ssl_cert);
326 		str = X509_NAME_oneline(name, 0, 0);
327 		printf("Certificate issuer: %s\n", str);
328 		free(str);
329 	}
330 
331 	return (0);
332 #else
333 	(void)conn;
334 	(void)verbose;
335 	fprintf(stderr, "SSL support disabled\n");
336 	return (-1);
337 #endif
338 }
339 
340 
341 /*
342  * Read a character from a connection w/ timeout
343  */
344 ssize_t
345 _fetch_read(conn_t *conn, char *buf, size_t len)
346 {
347 	struct timeval now, timeout, wait;
348 	fd_set readfds;
349 	ssize_t rlen, total;
350 	int r;
351 
352 	if (fetchTimeout) {
353 		FD_ZERO(&readfds);
354 		gettimeofday(&timeout, NULL);
355 		timeout.tv_sec += fetchTimeout;
356 	}
357 
358 	total = 0;
359 	while (len > 0) {
360 		while (fetchTimeout && !FD_ISSET(conn->sd, &readfds)) {
361 			FD_SET(conn->sd, &readfds);
362 			gettimeofday(&now, NULL);
363 			wait.tv_sec = timeout.tv_sec - now.tv_sec;
364 			wait.tv_usec = timeout.tv_usec - now.tv_usec;
365 			if (wait.tv_usec < 0) {
366 				wait.tv_usec += 1000000;
367 				wait.tv_sec--;
368 			}
369 			if (wait.tv_sec < 0) {
370 				errno = ETIMEDOUT;
371 				_fetch_syserr();
372 				return (-1);
373 			}
374 			errno = 0;
375 			r = select(conn->sd + 1, &readfds, NULL, NULL, &wait);
376 			if (r == -1) {
377 				if (errno == EINTR && fetchRestartCalls)
378 					continue;
379 				_fetch_syserr();
380 				return (-1);
381 			}
382 		}
383 #ifdef WITH_SSL
384 		if (conn->ssl != NULL)
385 			rlen = SSL_read(conn->ssl, buf, len);
386 		else
387 #endif
388 			rlen = read(conn->sd, buf, len);
389 		if (rlen == 0)
390 			break;
391 		if (rlen < 0) {
392 			if (errno == EINTR && fetchRestartCalls)
393 				continue;
394 			return (-1);
395 		}
396 		len -= rlen;
397 		buf += rlen;
398 		total += rlen;
399 	}
400 	return (total);
401 }
402 
403 
404 /*
405  * Read a line of text from a connection w/ timeout
406  */
407 #define MIN_BUF_SIZE 1024
408 
409 int
410 _fetch_getln(conn_t *conn)
411 {
412 	char *tmp;
413 	size_t tmpsize;
414 	ssize_t len;
415 	char c;
416 
417 	if (conn->buf == NULL) {
418 		if ((conn->buf = malloc(MIN_BUF_SIZE)) == NULL) {
419 			errno = ENOMEM;
420 			return (-1);
421 		}
422 		conn->bufsize = MIN_BUF_SIZE;
423 	}
424 
425 	conn->buf[0] = '\0';
426 	conn->buflen = 0;
427 
428 	do {
429 		len = _fetch_read(conn, &c, 1);
430 		if (len == -1)
431 			return (-1);
432 		if (len == 0)
433 			break;
434 		conn->buf[conn->buflen++] = c;
435 		if (conn->buflen == conn->bufsize) {
436 			tmp = conn->buf;
437 			tmpsize = conn->bufsize * 2 + 1;
438 			if ((tmp = realloc(tmp, tmpsize)) == NULL) {
439 				errno = ENOMEM;
440 				return (-1);
441 			}
442 			conn->buf = tmp;
443 			conn->bufsize = tmpsize;
444 		}
445 	} while (c != '\n');
446 
447 	conn->buf[conn->buflen] = '\0';
448 	DEBUG(fprintf(stderr, "<<< %s", conn->buf));
449 	return (0);
450 }
451 
452 
453 /*
454  * Write to a connection w/ timeout
455  */
456 ssize_t
457 _fetch_write(conn_t *conn, const char *buf, size_t len)
458 {
459 	struct iovec iov;
460 
461 	iov.iov_base = __DECONST(char *, buf);
462 	iov.iov_len = len;
463 	return _fetch_writev(conn, &iov, 1);
464 }
465 
466 /*
467  * Write a vector to a connection w/ timeout
468  * Note: can modify the iovec.
469  */
470 ssize_t
471 _fetch_writev(conn_t *conn, struct iovec *iov, int iovcnt)
472 {
473 	struct timeval now, timeout, wait;
474 	fd_set writefds;
475 	ssize_t wlen, total;
476 	int r;
477 
478 	if (fetchTimeout) {
479 		FD_ZERO(&writefds);
480 		gettimeofday(&timeout, NULL);
481 		timeout.tv_sec += fetchTimeout;
482 	}
483 
484 	total = 0;
485 	while (iovcnt > 0) {
486 		while (fetchTimeout && !FD_ISSET(conn->sd, &writefds)) {
487 			FD_SET(conn->sd, &writefds);
488 			gettimeofday(&now, NULL);
489 			wait.tv_sec = timeout.tv_sec - now.tv_sec;
490 			wait.tv_usec = timeout.tv_usec - now.tv_usec;
491 			if (wait.tv_usec < 0) {
492 				wait.tv_usec += 1000000;
493 				wait.tv_sec--;
494 			}
495 			if (wait.tv_sec < 0) {
496 				errno = ETIMEDOUT;
497 				_fetch_syserr();
498 				return (-1);
499 			}
500 			errno = 0;
501 			r = select(conn->sd + 1, NULL, &writefds, NULL, &wait);
502 			if (r == -1) {
503 				if (errno == EINTR && fetchRestartCalls)
504 					continue;
505 				return (-1);
506 			}
507 		}
508 		errno = 0;
509 #ifdef WITH_SSL
510 		if (conn->ssl != NULL)
511 			wlen = SSL_write(conn->ssl,
512 			    iov->iov_base, iov->iov_len);
513 		else
514 #endif
515 			wlen = writev(conn->sd, iov, iovcnt);
516 		if (wlen == 0) {
517 			/* we consider a short write a failure */
518 			errno = EPIPE;
519 			_fetch_syserr();
520 			return (-1);
521 		}
522 		if (wlen < 0) {
523 			if (errno == EINTR && fetchRestartCalls)
524 				continue;
525 			return (-1);
526 		}
527 		total += wlen;
528 		while (iovcnt > 0 && wlen >= (ssize_t)iov->iov_len) {
529 			wlen -= iov->iov_len;
530 			iov++;
531 			iovcnt--;
532 		}
533 		if (iovcnt > 0) {
534 			iov->iov_len -= wlen;
535 			iov->iov_base = __DECONST(char *, iov->iov_base) + wlen;
536 		}
537 	}
538 	return (total);
539 }
540 
541 
542 /*
543  * Write a line of text to a connection w/ timeout
544  */
545 int
546 _fetch_putln(conn_t *conn, const char *str, size_t len)
547 {
548 	struct iovec iov[2];
549 	int ret;
550 
551 	DEBUG(fprintf(stderr, ">>> %s\n", str));
552 	iov[0].iov_base = __DECONST(char *, str);
553 	iov[0].iov_len = len;
554 	iov[1].iov_base = __DECONST(char *, ENDL);
555 	iov[1].iov_len = sizeof(ENDL);
556 	if (len == 0)
557 		ret = _fetch_writev(conn, &iov[1], 1);
558 	else
559 		ret = _fetch_writev(conn, iov, 2);
560 	if (ret == -1)
561 		return (-1);
562 	return (0);
563 }
564 
565 
566 /*
567  * Close connection
568  */
569 int
570 _fetch_close(conn_t *conn)
571 {
572 	int ret;
573 
574 	if (--conn->ref > 0)
575 		return (0);
576 	ret = close(conn->sd);
577 	free(conn);
578 	return (ret);
579 }
580 
581 
582 /*** Directory-related utility functions *************************************/
583 
584 int
585 _fetch_add_entry(struct url_ent **p, int *size, int *len,
586     const char *name, struct url_stat *us)
587 {
588 	struct url_ent *tmp;
589 
590 	if (*p == NULL) {
591 		*size = 0;
592 		*len = 0;
593 	}
594 
595 	if (*len >= *size - 1) {
596 		tmp = realloc(*p, (*size * 2 + 1) * sizeof(**p));
597 		if (tmp == NULL) {
598 			errno = ENOMEM;
599 			_fetch_syserr();
600 			return (-1);
601 		}
602 		*size = (*size * 2 + 1);
603 		*p = tmp;
604 	}
605 
606 	tmp = *p + *len;
607 	snprintf(tmp->name, PATH_MAX, "%s", name);
608 	bcopy(us, &tmp->stat, sizeof(*us));
609 
610 	(*len)++;
611 	(++tmp)->name[0] = 0;
612 
613 	return (0);
614 }
615 
616 
617 /*** Authentication-related utility functions ********************************/
618 
619 static const char *
620 _fetch_read_word(FILE *f)
621 {
622 	static char word[1024];
623 
624 	if (fscanf(f, " %1024s ", word) != 1)
625 		return (NULL);
626 	return (word);
627 }
628 
629 /*
630  * Get authentication data for a URL from .netrc
631  */
632 int
633 _fetch_netrc_auth(struct url *url)
634 {
635 	char fn[PATH_MAX];
636 	const char *word;
637 	char *p;
638 	FILE *f;
639 
640 	if ((p = getenv("NETRC")) != NULL) {
641 		if (snprintf(fn, sizeof(fn), "%s", p) >= (int)sizeof(fn)) {
642 			_fetch_info("$NETRC specifies a file name "
643 			    "longer than PATH_MAX");
644 			return (-1);
645 		}
646 	} else {
647 		if ((p = getenv("HOME")) != NULL) {
648 			struct passwd *pwd;
649 
650 			if ((pwd = getpwuid(getuid())) == NULL ||
651 			    (p = pwd->pw_dir) == NULL)
652 				return (-1);
653 		}
654 		if (snprintf(fn, sizeof(fn), "%s/.netrc", p) >= (int)sizeof(fn))
655 			return (-1);
656 	}
657 
658 	if ((f = fopen(fn, "r")) == NULL)
659 		return (-1);
660 	while ((word = _fetch_read_word(f)) != NULL) {
661 		if (strcmp(word, "default") == 0) {
662 			DEBUG(_fetch_info("Using default .netrc settings"));
663 			break;
664 		}
665 		if (strcmp(word, "machine") == 0 &&
666 		    (word = _fetch_read_word(f)) != NULL &&
667 		    strcasecmp(word, url->host) == 0) {
668 			DEBUG(_fetch_info("Using .netrc settings for %s", word));
669 			break;
670 		}
671 	}
672 	if (word == NULL)
673 		goto ferr;
674 	while ((word = _fetch_read_word(f)) != NULL) {
675 		if (strcmp(word, "login") == 0) {
676 			if ((word = _fetch_read_word(f)) == NULL)
677 				goto ferr;
678 			if (snprintf(url->user, sizeof(url->user),
679 				"%s", word) > (int)sizeof(url->user)) {
680 				_fetch_info("login name in .netrc is too long");
681 				url->user[0] = '\0';
682 			}
683 		} else if (strcmp(word, "password") == 0) {
684 			if ((word = _fetch_read_word(f)) == NULL)
685 				goto ferr;
686 			if (snprintf(url->pwd, sizeof(url->pwd),
687 				"%s", word) > (int)sizeof(url->pwd)) {
688 				_fetch_info("password in .netrc is too long");
689 				url->pwd[0] = '\0';
690 			}
691 		} else if (strcmp(word, "account") == 0) {
692 			if ((word = _fetch_read_word(f)) == NULL)
693 				goto ferr;
694 			/* XXX not supported! */
695 		} else {
696 			break;
697 		}
698 	}
699 	fclose(f);
700 	return (0);
701  ferr:
702 	fclose(f);
703 	return (-1);
704 }
705