xref: /freebsd/lib/libfetch/ftp.c (revision d056fa046c6a91b90cd98165face0e42a33a5173)
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 /*
33  * Portions of this code were taken from or based on ftpio.c:
34  *
35  * ----------------------------------------------------------------------------
36  * "THE BEER-WARE LICENSE" (Revision 42):
37  * <phk@FreeBSD.org> wrote this file.  As long as you retain this notice you
38  * can do whatever you want with this stuff. If we meet some day, and you think
39  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
40  * ----------------------------------------------------------------------------
41  *
42  * Major Changelog:
43  *
44  * Dag-Erling Co�dan Sm�rgrav
45  * 9 Jun 1998
46  *
47  * Incorporated into libfetch
48  *
49  * Jordan K. Hubbard
50  * 17 Jan 1996
51  *
52  * Turned inside out. Now returns xfers as new file ids, not as a special
53  * `state' of FTP_t
54  *
55  * $ftpioId: ftpio.c,v 1.30 1998/04/11 07:28:53 phk Exp $
56  *
57  */
58 
59 #include <sys/param.h>
60 #include <sys/socket.h>
61 #include <netinet/in.h>
62 
63 #include <ctype.h>
64 #include <err.h>
65 #include <errno.h>
66 #include <fcntl.h>
67 #include <netdb.h>
68 #include <stdarg.h>
69 #include <stdint.h>
70 #include <stdio.h>
71 #include <stdlib.h>
72 #include <string.h>
73 #include <time.h>
74 #include <unistd.h>
75 
76 #include "fetch.h"
77 #include "common.h"
78 #include "ftperr.h"
79 
80 #define FTP_ANONYMOUS_USER	"anonymous"
81 
82 #define FTP_CONNECTION_ALREADY_OPEN	125
83 #define FTP_OPEN_DATA_CONNECTION	150
84 #define FTP_OK				200
85 #define FTP_FILE_STATUS			213
86 #define FTP_SERVICE_READY		220
87 #define FTP_TRANSFER_COMPLETE		226
88 #define FTP_PASSIVE_MODE		227
89 #define FTP_LPASSIVE_MODE		228
90 #define FTP_EPASSIVE_MODE		229
91 #define FTP_LOGGED_IN			230
92 #define FTP_FILE_ACTION_OK		250
93 #define FTP_DIRECTORY_CREATED		257 /* multiple meanings */
94 #define FTP_FILE_CREATED		257 /* multiple meanings */
95 #define FTP_WORKING_DIRECTORY		257 /* multiple meanings */
96 #define FTP_NEED_PASSWORD		331
97 #define FTP_NEED_ACCOUNT		332
98 #define FTP_FILE_OK			350
99 #define FTP_SYNTAX_ERROR		500
100 #define FTP_PROTOCOL_ERROR		999
101 
102 static struct url cached_host;
103 static conn_t	*cached_connection;
104 
105 #define isftpreply(foo) (isdigit(foo[0]) && isdigit(foo[1]) \
106 			 && isdigit(foo[2]) \
107 			 && (foo[3] == ' ' || foo[3] == '\0'))
108 #define isftpinfo(foo) (isdigit(foo[0]) && isdigit(foo[1]) \
109 			&& isdigit(foo[2]) && foo[3] == '-')
110 
111 /*
112  * Translate IPv4 mapped IPv6 address to IPv4 address
113  */
114 static void
115 unmappedaddr(struct sockaddr_in6 *sin6)
116 {
117 	struct sockaddr_in *sin4;
118 	u_int32_t addr;
119 	int port;
120 
121 	if (sin6->sin6_family != AF_INET6 ||
122 	    !IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
123 		return;
124 	sin4 = (struct sockaddr_in *)sin6;
125 	addr = *(u_int32_t *)&sin6->sin6_addr.s6_addr[12];
126 	port = sin6->sin6_port;
127 	memset(sin4, 0, sizeof(struct sockaddr_in));
128 	sin4->sin_addr.s_addr = addr;
129 	sin4->sin_port = port;
130 	sin4->sin_family = AF_INET;
131 	sin4->sin_len = sizeof(struct sockaddr_in);
132 }
133 
134 /*
135  * Get server response
136  */
137 static int
138 _ftp_chkerr(conn_t *conn)
139 {
140 	if (_fetch_getln(conn) == -1) {
141 		_fetch_syserr();
142 		return (-1);
143 	}
144 	if (isftpinfo(conn->buf)) {
145 		while (conn->buflen && !isftpreply(conn->buf)) {
146 			if (_fetch_getln(conn) == -1) {
147 				_fetch_syserr();
148 				return (-1);
149 			}
150 		}
151 	}
152 
153 	while (conn->buflen && isspace(conn->buf[conn->buflen - 1]))
154 		conn->buflen--;
155 	conn->buf[conn->buflen] = '\0';
156 
157 	if (!isftpreply(conn->buf)) {
158 		_ftp_seterr(FTP_PROTOCOL_ERROR);
159 		return (-1);
160 	}
161 
162 	conn->err = (conn->buf[0] - '0') * 100
163 	    + (conn->buf[1] - '0') * 10
164 	    + (conn->buf[2] - '0');
165 
166 	return (conn->err);
167 }
168 
169 /*
170  * Send a command and check reply
171  */
172 static int
173 _ftp_cmd(conn_t *conn, const char *fmt, ...)
174 {
175 	va_list ap;
176 	size_t len;
177 	char *msg;
178 	int r;
179 
180 	va_start(ap, fmt);
181 	len = vasprintf(&msg, fmt, ap);
182 	va_end(ap);
183 
184 	if (msg == NULL) {
185 		errno = ENOMEM;
186 		_fetch_syserr();
187 		return (-1);
188 	}
189 
190 	r = _fetch_putln(conn, msg, len);
191 	free(msg);
192 
193 	if (r == -1) {
194 		_fetch_syserr();
195 		return (-1);
196 	}
197 
198 	return (_ftp_chkerr(conn));
199 }
200 
201 /*
202  * Return a pointer to the filename part of a path
203  */
204 static const char *
205 _ftp_filename(const char *file, int *len, int *type)
206 {
207 	const char *s;
208 
209 	if ((s = strrchr(file, '/')) == NULL)
210 		s = file;
211 	else
212 		s = s + 1;
213 	*len = strlen(s);
214 	if (*len > 7 && strncmp(s + *len - 7, ";type=", 6) == 0) {
215 		*type = s[*len - 1];
216 		*len -= 7;
217 	} else {
218 		*type = '\0';
219 	}
220 	return (s);
221 }
222 
223 /*
224  * Get current working directory from the reply to a CWD, PWD or CDUP
225  * command.
226  */
227 static int
228 _ftp_pwd(conn_t *conn, char *pwd, size_t pwdlen)
229 {
230 	char *src, *dst, *end;
231 	int q;
232 
233 	if (conn->err != FTP_WORKING_DIRECTORY &&
234 	    conn->err != FTP_FILE_ACTION_OK)
235 		return (FTP_PROTOCOL_ERROR);
236 	end = conn->buf + conn->buflen;
237 	src = conn->buf + 4;
238 	if (src >= end || *src++ != '"')
239 		return (FTP_PROTOCOL_ERROR);
240 	for (q = 0, dst = pwd; src < end && pwdlen--; ++src) {
241 		if (!q && *src == '"')
242 			q = 1;
243 		else if (q && *src != '"')
244 			break;
245 		else if (q)
246 			*dst++ = '"', q = 0;
247 		else
248 			*dst++ = *src;
249 	}
250 	if (!pwdlen)
251 		return (FTP_PROTOCOL_ERROR);
252 	*dst = '\0';
253 #if 0
254 	DEBUG(fprintf(stderr, "pwd: [%s]\n", pwd));
255 #endif
256 	return (FTP_OK);
257 }
258 
259 /*
260  * Change working directory to the directory that contains the specified
261  * file.
262  */
263 static int
264 _ftp_cwd(conn_t *conn, const char *file)
265 {
266 	const char *beg, *end;
267 	char pwd[PATH_MAX];
268 	int e, i, len;
269 
270 	if ((end = strrchr(file, '/')) == NULL)
271 		return (0);
272 	if ((e = _ftp_cmd(conn, "PWD")) != FTP_WORKING_DIRECTORY ||
273 	    (e = _ftp_pwd(conn, pwd, sizeof(pwd))) != FTP_OK) {
274 		_ftp_seterr(e);
275 		return (-1);
276 	}
277 	for (;;) {
278 		len = strlen(pwd);
279 		/* look for a common prefix */
280 		for (i = 0; i <= len && i <= end - file; ++i)
281 			if (pwd[i] != file[i])
282 				break;
283 #if 0
284 		DEBUG(fprintf(stderr, "have: [%.*s|%s]\n", i, pwd, pwd + i));
285 		DEBUG(fprintf(stderr, "want: [%.*s|%s]\n", i, file, file + i));
286 #endif
287 		if (pwd[i] == '\0' && (file[i - 1] == '/' || file[i] == '/'))
288 			break;
289 		if ((e = _ftp_cmd(conn, "CDUP")) != FTP_FILE_ACTION_OK ||
290 		    (e = _ftp_cmd(conn, "PWD")) != FTP_WORKING_DIRECTORY ||
291 		    (e = _ftp_pwd(conn, pwd, sizeof(pwd))) != FTP_OK) {
292 			_ftp_seterr(e);
293 			return (-1);
294 		}
295 	}
296 	for (beg = file + i; beg < end; beg = file + i + 1) {
297 		while (*beg == '/')
298 			++beg, ++i;
299 		for (++i; file + i < end && file[i] != '/'; ++i)
300 			/* nothing */ ;
301 		e = _ftp_cmd(conn, "CWD %.*s", file + i - beg, beg);
302 		if (e != FTP_FILE_ACTION_OK) {
303 			_ftp_seterr(e);
304 			return (-1);
305 		}
306 	}
307 	return (0);
308 }
309 
310 /*
311  * Set transfer mode and data type
312  */
313 static int
314 _ftp_mode_type(conn_t *conn, int mode, int type)
315 {
316 	int e;
317 
318 	switch (mode) {
319 	case 0:
320 	case 's':
321 		mode = 'S';
322 	case 'S':
323 		break;
324 	default:
325 		return (FTP_PROTOCOL_ERROR);
326 	}
327 	if ((e = _ftp_cmd(conn, "MODE %c", mode)) != FTP_OK) {
328 		if (mode == 'S') {
329 			/*
330 			 * Stream mode is supposed to be the default - so
331 			 * much so that some servers not only do not
332 			 * support any other mode, but do not support the
333 			 * MODE command at all.
334 			 *
335 			 * If "MODE S" fails, it is unlikely that we
336 			 * previously succeeded in setting a different
337 			 * mode.  Therefore, we simply hope that the
338 			 * server is already in the correct mode, and
339 			 * silently ignore the failure.
340 			 */
341 		} else {
342 			return (e);
343 		}
344 	}
345 
346 	switch (type) {
347 	case 0:
348 	case 'i':
349 		type = 'I';
350 	case 'I':
351 		break;
352 	case 'a':
353 		type = 'A';
354 	case 'A':
355 		break;
356 	case 'd':
357 		type = 'D';
358 	case 'D':
359 		/* can't handle yet */
360 	default:
361 		return (FTP_PROTOCOL_ERROR);
362 	}
363 	if ((e = _ftp_cmd(conn, "TYPE %c", type)) != FTP_OK)
364 		return (e);
365 
366 	return (FTP_OK);
367 }
368 
369 /*
370  * Request and parse file stats
371  */
372 static int
373 _ftp_stat(conn_t *conn, const char *file, struct url_stat *us)
374 {
375 	char *ln;
376 	const char *filename;
377 	int filenamelen, type;
378 	struct tm tm;
379 	time_t t;
380 	int e;
381 
382 	us->size = -1;
383 	us->atime = us->mtime = 0;
384 
385 	filename = _ftp_filename(file, &filenamelen, &type);
386 
387 	if ((e = _ftp_mode_type(conn, 0, type)) != FTP_OK) {
388 		_ftp_seterr(e);
389 		return (-1);
390 	}
391 
392 	e = _ftp_cmd(conn, "SIZE %.*s", filenamelen, filename);
393 	if (e != FTP_FILE_STATUS) {
394 		_ftp_seterr(e);
395 		return (-1);
396 	}
397 	for (ln = conn->buf + 4; *ln && isspace(*ln); ln++)
398 		/* nothing */ ;
399 	for (us->size = 0; *ln && isdigit(*ln); ln++)
400 		us->size = us->size * 10 + *ln - '0';
401 	if (*ln && !isspace(*ln)) {
402 		_ftp_seterr(FTP_PROTOCOL_ERROR);
403 		us->size = -1;
404 		return (-1);
405 	}
406 	if (us->size == 0)
407 		us->size = -1;
408 	DEBUG(fprintf(stderr, "size: [%lld]\n", (long long)us->size));
409 
410 	e = _ftp_cmd(conn, "MDTM %.*s", filenamelen, filename);
411 	if (e != FTP_FILE_STATUS) {
412 		_ftp_seterr(e);
413 		return (-1);
414 	}
415 	for (ln = conn->buf + 4; *ln && isspace(*ln); ln++)
416 		/* nothing */ ;
417 	switch (strspn(ln, "0123456789")) {
418 	case 14:
419 		break;
420 	case 15:
421 		ln++;
422 		ln[0] = '2';
423 		ln[1] = '0';
424 		break;
425 	default:
426 		_ftp_seterr(FTP_PROTOCOL_ERROR);
427 		return (-1);
428 	}
429 	if (sscanf(ln, "%04d%02d%02d%02d%02d%02d",
430 	    &tm.tm_year, &tm.tm_mon, &tm.tm_mday,
431 	    &tm.tm_hour, &tm.tm_min, &tm.tm_sec) != 6) {
432 		_ftp_seterr(FTP_PROTOCOL_ERROR);
433 		return (-1);
434 	}
435 	tm.tm_mon--;
436 	tm.tm_year -= 1900;
437 	tm.tm_isdst = -1;
438 	t = timegm(&tm);
439 	if (t == (time_t)-1)
440 		t = time(NULL);
441 	us->mtime = t;
442 	us->atime = t;
443 	DEBUG(fprintf(stderr,
444 	    "last modified: [%04d-%02d-%02d %02d:%02d:%02d]\n",
445 	    tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
446 	    tm.tm_hour, tm.tm_min, tm.tm_sec));
447 	return (0);
448 }
449 
450 /*
451  * I/O functions for FTP
452  */
453 struct ftpio {
454 	conn_t	*cconn;		/* Control connection */
455 	conn_t	*dconn;		/* Data connection */
456 	int	 dir;		/* Direction */
457 	int	 eof;		/* EOF reached */
458 	int	 err;		/* Error code */
459 };
460 
461 static int	 _ftp_readfn(void *, char *, int);
462 static int	 _ftp_writefn(void *, const char *, int);
463 static fpos_t	 _ftp_seekfn(void *, fpos_t, int);
464 static int	 _ftp_closefn(void *);
465 
466 static int
467 _ftp_readfn(void *v, char *buf, int len)
468 {
469 	struct ftpio *io;
470 	int r;
471 
472 	io = (struct ftpio *)v;
473 	if (io == NULL) {
474 		errno = EBADF;
475 		return (-1);
476 	}
477 	if (io->cconn == NULL || io->dconn == NULL || io->dir == O_WRONLY) {
478 		errno = EBADF;
479 		return (-1);
480 	}
481 	if (io->err) {
482 		errno = io->err;
483 		return (-1);
484 	}
485 	if (io->eof)
486 		return (0);
487 	r = _fetch_read(io->dconn, buf, len);
488 	if (r > 0)
489 		return (r);
490 	if (r == 0) {
491 		io->eof = 1;
492 		return (0);
493 	}
494 	if (errno != EINTR)
495 		io->err = errno;
496 	return (-1);
497 }
498 
499 static int
500 _ftp_writefn(void *v, const char *buf, int len)
501 {
502 	struct ftpio *io;
503 	int w;
504 
505 	io = (struct ftpio *)v;
506 	if (io == NULL) {
507 		errno = EBADF;
508 		return (-1);
509 	}
510 	if (io->cconn == NULL || io->dconn == NULL || io->dir == O_RDONLY) {
511 		errno = EBADF;
512 		return (-1);
513 	}
514 	if (io->err) {
515 		errno = io->err;
516 		return (-1);
517 	}
518 	w = _fetch_write(io->dconn, buf, len);
519 	if (w >= 0)
520 		return (w);
521 	if (errno != EINTR)
522 		io->err = errno;
523 	return (-1);
524 }
525 
526 static fpos_t
527 _ftp_seekfn(void *v, fpos_t pos __unused, int whence __unused)
528 {
529 	struct ftpio *io;
530 
531 	io = (struct ftpio *)v;
532 	if (io == NULL) {
533 		errno = EBADF;
534 		return (-1);
535 	}
536 	errno = ESPIPE;
537 	return (-1);
538 }
539 
540 static int
541 _ftp_closefn(void *v)
542 {
543 	struct ftpio *io;
544 	int r;
545 
546 	io = (struct ftpio *)v;
547 	if (io == NULL) {
548 		errno = EBADF;
549 		return (-1);
550 	}
551 	if (io->dir == -1)
552 		return (0);
553 	if (io->cconn == NULL || io->dconn == NULL) {
554 		errno = EBADF;
555 		return (-1);
556 	}
557 	_fetch_close(io->dconn);
558 	io->dir = -1;
559 	io->dconn = NULL;
560 	DEBUG(fprintf(stderr, "Waiting for final status\n"));
561 	r = _ftp_chkerr(io->cconn);
562 	if (io->cconn == cached_connection && io->cconn->ref == 1)
563 		cached_connection = NULL;
564 	_fetch_close(io->cconn);
565 	free(io);
566 	return (r == FTP_TRANSFER_COMPLETE) ? 0 : -1;
567 }
568 
569 static FILE *
570 _ftp_setup(conn_t *cconn, conn_t *dconn, int mode)
571 {
572 	struct ftpio *io;
573 	FILE *f;
574 
575 	if (cconn == NULL || dconn == NULL)
576 		return (NULL);
577 	if ((io = malloc(sizeof(*io))) == NULL)
578 		return (NULL);
579 	io->cconn = cconn;
580 	io->dconn = dconn;
581 	io->dir = mode;
582 	io->eof = io->err = 0;
583 	f = funopen(io, _ftp_readfn, _ftp_writefn, _ftp_seekfn, _ftp_closefn);
584 	if (f == NULL)
585 		free(io);
586 	return (f);
587 }
588 
589 /*
590  * Transfer file
591  */
592 static FILE *
593 _ftp_transfer(conn_t *conn, const char *oper, const char *file,
594     int mode, off_t offset, const char *flags)
595 {
596 	struct sockaddr_storage sa;
597 	struct sockaddr_in6 *sin6;
598 	struct sockaddr_in *sin4;
599 	const char *bindaddr;
600 	const char *filename;
601 	int filenamelen, type;
602 	int low, pasv, verbose;
603 	int e, sd = -1;
604 	socklen_t l;
605 	char *s;
606 	FILE *df;
607 
608 	/* check flags */
609 	low = CHECK_FLAG('l');
610 	pasv = CHECK_FLAG('p');
611 	verbose = CHECK_FLAG('v');
612 
613 	/* passive mode */
614 	if (!pasv)
615 		pasv = ((s = getenv("FTP_PASSIVE_MODE")) != NULL &&
616 		    strncasecmp(s, "no", 2) != 0);
617 
618 	/* isolate filename */
619 	filename = _ftp_filename(file, &filenamelen, &type);
620 
621 	/* set transfer mode and data type */
622 	if ((e = _ftp_mode_type(conn, 0, type)) != FTP_OK)
623 		goto ouch;
624 
625 	/* find our own address, bind, and listen */
626 	l = sizeof(sa);
627 	if (getsockname(conn->sd, (struct sockaddr *)&sa, &l) == -1)
628 		goto sysouch;
629 	if (sa.ss_family == AF_INET6)
630 		unmappedaddr((struct sockaddr_in6 *)&sa);
631 
632 	/* open data socket */
633 	if ((sd = socket(sa.ss_family, SOCK_STREAM, IPPROTO_TCP)) == -1) {
634 		_fetch_syserr();
635 		return (NULL);
636 	}
637 
638 	if (pasv) {
639 		u_char addr[64];
640 		char *ln, *p;
641 		unsigned int i;
642 		int port;
643 
644 		/* send PASV command */
645 		if (verbose)
646 			_fetch_info("setting passive mode");
647 		switch (sa.ss_family) {
648 		case AF_INET:
649 			if ((e = _ftp_cmd(conn, "PASV")) != FTP_PASSIVE_MODE)
650 				goto ouch;
651 			break;
652 		case AF_INET6:
653 			if ((e = _ftp_cmd(conn, "EPSV")) != FTP_EPASSIVE_MODE) {
654 				if (e == -1)
655 					goto ouch;
656 				if ((e = _ftp_cmd(conn, "LPSV")) !=
657 				    FTP_LPASSIVE_MODE)
658 					goto ouch;
659 			}
660 			break;
661 		default:
662 			e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
663 			goto ouch;
664 		}
665 
666 		/*
667 		 * Find address and port number. The reply to the PASV command
668 		 * is IMHO the one and only weak point in the FTP protocol.
669 		 */
670 		ln = conn->buf;
671 		switch (e) {
672 		case FTP_PASSIVE_MODE:
673 		case FTP_LPASSIVE_MODE:
674 			for (p = ln + 3; *p && !isdigit(*p); p++)
675 				/* nothing */ ;
676 			if (!*p) {
677 				e = FTP_PROTOCOL_ERROR;
678 				goto ouch;
679 			}
680 			l = (e == FTP_PASSIVE_MODE ? 6 : 21);
681 			for (i = 0; *p && i < l; i++, p++)
682 				addr[i] = strtol(p, &p, 10);
683 			if (i < l) {
684 				e = FTP_PROTOCOL_ERROR;
685 				goto ouch;
686 			}
687 			break;
688 		case FTP_EPASSIVE_MODE:
689 			for (p = ln + 3; *p && *p != '('; p++)
690 				/* nothing */ ;
691 			if (!*p) {
692 				e = FTP_PROTOCOL_ERROR;
693 				goto ouch;
694 			}
695 			++p;
696 			if (sscanf(p, "%c%c%c%d%c", &addr[0], &addr[1], &addr[2],
697 				&port, &addr[3]) != 5 ||
698 			    addr[0] != addr[1] ||
699 			    addr[0] != addr[2] || addr[0] != addr[3]) {
700 				e = FTP_PROTOCOL_ERROR;
701 				goto ouch;
702 			}
703 			break;
704 		}
705 
706 		/* seek to required offset */
707 		if (offset)
708 			if (_ftp_cmd(conn, "REST %lu", (u_long)offset) != FTP_FILE_OK)
709 				goto sysouch;
710 
711 		/* construct sockaddr for data socket */
712 		l = sizeof(sa);
713 		if (getpeername(conn->sd, (struct sockaddr *)&sa, &l) == -1)
714 			goto sysouch;
715 		if (sa.ss_family == AF_INET6)
716 			unmappedaddr((struct sockaddr_in6 *)&sa);
717 		switch (sa.ss_family) {
718 		case AF_INET6:
719 			sin6 = (struct sockaddr_in6 *)&sa;
720 			if (e == FTP_EPASSIVE_MODE)
721 				sin6->sin6_port = htons(port);
722 			else {
723 				bcopy(addr + 2, (char *)&sin6->sin6_addr, 16);
724 				bcopy(addr + 19, (char *)&sin6->sin6_port, 2);
725 			}
726 			break;
727 		case AF_INET:
728 			sin4 = (struct sockaddr_in *)&sa;
729 			if (e == FTP_EPASSIVE_MODE)
730 				sin4->sin_port = htons(port);
731 			else {
732 				bcopy(addr, (char *)&sin4->sin_addr, 4);
733 				bcopy(addr + 4, (char *)&sin4->sin_port, 2);
734 			}
735 			break;
736 		default:
737 			e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
738 			break;
739 		}
740 
741 		/* connect to data port */
742 		if (verbose)
743 			_fetch_info("opening data connection");
744 		bindaddr = getenv("FETCH_BIND_ADDRESS");
745 		if (bindaddr != NULL && *bindaddr != '\0' &&
746 		    _fetch_bind(sd, sa.ss_family, bindaddr) != 0)
747 			goto sysouch;
748 		if (connect(sd, (struct sockaddr *)&sa, sa.ss_len) == -1)
749 			goto sysouch;
750 
751 		/* make the server initiate the transfer */
752 		if (verbose)
753 			_fetch_info("initiating transfer");
754 		e = _ftp_cmd(conn, "%s %.*s", oper, filenamelen, filename);
755 		if (e != FTP_CONNECTION_ALREADY_OPEN && e != FTP_OPEN_DATA_CONNECTION)
756 			goto ouch;
757 
758 	} else {
759 		u_int32_t a;
760 		u_short p;
761 		int arg, d;
762 		char *ap;
763 		char hname[INET6_ADDRSTRLEN];
764 
765 		switch (sa.ss_family) {
766 		case AF_INET6:
767 			((struct sockaddr_in6 *)&sa)->sin6_port = 0;
768 #ifdef IPV6_PORTRANGE
769 			arg = low ? IPV6_PORTRANGE_DEFAULT : IPV6_PORTRANGE_HIGH;
770 			if (setsockopt(sd, IPPROTO_IPV6, IPV6_PORTRANGE,
771 				(char *)&arg, sizeof(arg)) == -1)
772 				goto sysouch;
773 #endif
774 			break;
775 		case AF_INET:
776 			((struct sockaddr_in *)&sa)->sin_port = 0;
777 			arg = low ? IP_PORTRANGE_DEFAULT : IP_PORTRANGE_HIGH;
778 			if (setsockopt(sd, IPPROTO_IP, IP_PORTRANGE,
779 				(char *)&arg, sizeof(arg)) == -1)
780 				goto sysouch;
781 			break;
782 		}
783 		if (verbose)
784 			_fetch_info("binding data socket");
785 		if (bind(sd, (struct sockaddr *)&sa, sa.ss_len) == -1)
786 			goto sysouch;
787 		if (listen(sd, 1) == -1)
788 			goto sysouch;
789 
790 		/* find what port we're on and tell the server */
791 		if (getsockname(sd, (struct sockaddr *)&sa, &l) == -1)
792 			goto sysouch;
793 		switch (sa.ss_family) {
794 		case AF_INET:
795 			sin4 = (struct sockaddr_in *)&sa;
796 			a = ntohl(sin4->sin_addr.s_addr);
797 			p = ntohs(sin4->sin_port);
798 			e = _ftp_cmd(conn, "PORT %d,%d,%d,%d,%d,%d",
799 			    (a >> 24) & 0xff, (a >> 16) & 0xff,
800 			    (a >> 8) & 0xff, a & 0xff,
801 			    (p >> 8) & 0xff, p & 0xff);
802 			break;
803 		case AF_INET6:
804 #define UC(b)	(((int)b)&0xff)
805 			e = -1;
806 			sin6 = (struct sockaddr_in6 *)&sa;
807 			sin6->sin6_scope_id = 0;
808 			if (getnameinfo((struct sockaddr *)&sa, sa.ss_len,
809 				hname, sizeof(hname),
810 				NULL, 0, NI_NUMERICHOST) == 0) {
811 				e = _ftp_cmd(conn, "EPRT |%d|%s|%d|", 2, hname,
812 				    htons(sin6->sin6_port));
813 				if (e == -1)
814 					goto ouch;
815 			}
816 			if (e != FTP_OK) {
817 				ap = (char *)&sin6->sin6_addr;
818 				e = _ftp_cmd(conn,
819 				    "LPRT %d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d",
820 				    6, 16,
821 				    UC(ap[0]), UC(ap[1]), UC(ap[2]), UC(ap[3]),
822 				    UC(ap[4]), UC(ap[5]), UC(ap[6]), UC(ap[7]),
823 				    UC(ap[8]), UC(ap[9]), UC(ap[10]), UC(ap[11]),
824 				    UC(ap[12]), UC(ap[13]), UC(ap[14]), UC(ap[15]),
825 				    2,
826 				    (ntohs(sin6->sin6_port) >> 8) & 0xff,
827 				    ntohs(sin6->sin6_port)        & 0xff);
828 			}
829 			break;
830 		default:
831 			e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
832 			goto ouch;
833 		}
834 		if (e != FTP_OK)
835 			goto ouch;
836 
837 		/* seek to required offset */
838 		if (offset)
839 			if (_ftp_cmd(conn, "REST %ju", (uintmax_t)offset) != FTP_FILE_OK)
840 				goto sysouch;
841 
842 		/* make the server initiate the transfer */
843 		if (verbose)
844 			_fetch_info("initiating transfer");
845 		e = _ftp_cmd(conn, "%s %.*s", oper, filenamelen, filename);
846 		if (e != FTP_CONNECTION_ALREADY_OPEN && e != FTP_OPEN_DATA_CONNECTION)
847 			goto ouch;
848 
849 		/* accept the incoming connection and go to town */
850 		if ((d = accept(sd, NULL, NULL)) == -1)
851 			goto sysouch;
852 		close(sd);
853 		sd = d;
854 	}
855 
856 	if ((df = _ftp_setup(conn, _fetch_reopen(sd), mode)) == NULL)
857 		goto sysouch;
858 	return (df);
859 
860 sysouch:
861 	_fetch_syserr();
862 	if (sd >= 0)
863 		close(sd);
864 	return (NULL);
865 
866 ouch:
867 	if (e != -1)
868 		_ftp_seterr(e);
869 	if (sd >= 0)
870 		close(sd);
871 	return (NULL);
872 }
873 
874 /*
875  * Authenticate
876  */
877 static int
878 _ftp_authenticate(conn_t *conn, struct url *url, struct url *purl)
879 {
880 	const char *user, *pwd, *logname;
881 	char pbuf[MAXHOSTNAMELEN + MAXLOGNAME + 1];
882 	int e, len;
883 
884 	/* XXX FTP_AUTH, and maybe .netrc */
885 
886 	/* send user name and password */
887 	if (url->user[0] == '\0')
888 		_fetch_netrc_auth(url);
889 	user = url->user;
890 	if (*user == '\0')
891 		user = getenv("FTP_LOGIN");
892 	if (user == NULL || *user == '\0')
893 		user = FTP_ANONYMOUS_USER;
894 	if (purl && url->port == _fetch_default_port(url->scheme))
895 		e = _ftp_cmd(conn, "USER %s@%s", user, url->host);
896 	else if (purl)
897 		e = _ftp_cmd(conn, "USER %s@%s@%d", user, url->host, url->port);
898 	else
899 		e = _ftp_cmd(conn, "USER %s", user);
900 
901 	/* did the server request a password? */
902 	if (e == FTP_NEED_PASSWORD) {
903 		pwd = url->pwd;
904 		if (*pwd == '\0')
905 			pwd = getenv("FTP_PASSWORD");
906 		if (pwd == NULL || *pwd == '\0') {
907 			if ((logname = getlogin()) == 0)
908 				logname = FTP_ANONYMOUS_USER;
909 			if ((len = snprintf(pbuf, MAXLOGNAME + 1, "%s@", logname)) < 0)
910 				len = 0;
911 			else if (len > MAXLOGNAME)
912 				len = MAXLOGNAME;
913 			gethostname(pbuf + len, sizeof(pbuf) - len);
914 			pwd = pbuf;
915 		}
916 		e = _ftp_cmd(conn, "PASS %s", pwd);
917 	}
918 
919 	return (e);
920 }
921 
922 /*
923  * Log on to FTP server
924  */
925 static conn_t *
926 _ftp_connect(struct url *url, struct url *purl, const char *flags)
927 {
928 	conn_t *conn;
929 	int e, direct, verbose;
930 #ifdef INET6
931 	int af = AF_UNSPEC;
932 #else
933 	int af = AF_INET;
934 #endif
935 
936 	direct = CHECK_FLAG('d');
937 	verbose = CHECK_FLAG('v');
938 	if (CHECK_FLAG('4'))
939 		af = AF_INET;
940 	else if (CHECK_FLAG('6'))
941 		af = AF_INET6;
942 
943 	if (direct)
944 		purl = NULL;
945 
946 	/* check for proxy */
947 	if (purl) {
948 		/* XXX proxy authentication! */
949 		conn = _fetch_connect(purl->host, purl->port, af, verbose);
950 	} else {
951 		/* no proxy, go straight to target */
952 		conn = _fetch_connect(url->host, url->port, af, verbose);
953 		purl = NULL;
954 	}
955 
956 	/* check connection */
957 	if (conn == NULL)
958 		/* _fetch_connect() has already set an error code */
959 		return (NULL);
960 
961 	/* expect welcome message */
962 	if ((e = _ftp_chkerr(conn)) != FTP_SERVICE_READY)
963 		goto fouch;
964 
965 	/* authenticate */
966 	if ((e = _ftp_authenticate(conn, url, purl)) != FTP_LOGGED_IN)
967 		goto fouch;
968 
969 	/* done */
970 	return (conn);
971 
972 fouch:
973 	if (e != -1)
974 		_ftp_seterr(e);
975 	_fetch_close(conn);
976 	return (NULL);
977 }
978 
979 /*
980  * Disconnect from server
981  */
982 static void
983 _ftp_disconnect(conn_t *conn)
984 {
985 	(void)_ftp_cmd(conn, "QUIT");
986 	if (conn == cached_connection && conn->ref == 1)
987 		cached_connection = NULL;
988 	_fetch_close(conn);
989 }
990 
991 /*
992  * Check if we're already connected
993  */
994 static int
995 _ftp_isconnected(struct url *url)
996 {
997 	return (cached_connection
998 	    && (strcmp(url->host, cached_host.host) == 0)
999 	    && (strcmp(url->user, cached_host.user) == 0)
1000 	    && (strcmp(url->pwd, cached_host.pwd) == 0)
1001 	    && (url->port == cached_host.port));
1002 }
1003 
1004 /*
1005  * Check the cache, reconnect if no luck
1006  */
1007 static conn_t *
1008 _ftp_cached_connect(struct url *url, struct url *purl, const char *flags)
1009 {
1010 	conn_t *conn;
1011 	int e;
1012 
1013 	/* set default port */
1014 	if (!url->port)
1015 		url->port = _fetch_default_port(url->scheme);
1016 
1017 	/* try to use previously cached connection */
1018 	if (_ftp_isconnected(url)) {
1019 		e = _ftp_cmd(cached_connection, "NOOP");
1020 		if (e == FTP_OK || e == FTP_SYNTAX_ERROR)
1021 			return (_fetch_ref(cached_connection));
1022 	}
1023 
1024 	/* connect to server */
1025 	if ((conn = _ftp_connect(url, purl, flags)) == NULL)
1026 		return (NULL);
1027 	if (cached_connection)
1028 		_ftp_disconnect(cached_connection);
1029 	cached_connection = _fetch_ref(conn);
1030 	memcpy(&cached_host, url, sizeof(*url));
1031 	return (conn);
1032 }
1033 
1034 /*
1035  * Check the proxy settings
1036  */
1037 static struct url *
1038 _ftp_get_proxy(const char *flags)
1039 {
1040 	struct url *purl;
1041 	char *p;
1042 
1043 	if (flags != NULL && strchr(flags, 'd') != NULL)
1044 		return (NULL);
1045 	if (((p = getenv("FTP_PROXY")) || (p = getenv("ftp_proxy")) ||
1046 		(p = getenv("HTTP_PROXY")) || (p = getenv("http_proxy"))) &&
1047 	    *p && (purl = fetchParseURL(p)) != NULL) {
1048 		if (!*purl->scheme) {
1049 			if (getenv("FTP_PROXY") || getenv("ftp_proxy"))
1050 				strcpy(purl->scheme, SCHEME_FTP);
1051 			else
1052 				strcpy(purl->scheme, SCHEME_HTTP);
1053 		}
1054 		if (!purl->port)
1055 			purl->port = _fetch_default_proxy_port(purl->scheme);
1056 		if (strcasecmp(purl->scheme, SCHEME_FTP) == 0 ||
1057 		    strcasecmp(purl->scheme, SCHEME_HTTP) == 0)
1058 			return (purl);
1059 		fetchFreeURL(purl);
1060 	}
1061 	return (NULL);
1062 }
1063 
1064 /*
1065  * Process an FTP request
1066  */
1067 FILE *
1068 _ftp_request(struct url *url, const char *op, struct url_stat *us,
1069     struct url *purl, const char *flags)
1070 {
1071 	conn_t *conn;
1072 	int oflag;
1073 
1074 	/* check if we should use HTTP instead */
1075 	if (purl && strcasecmp(purl->scheme, SCHEME_HTTP) == 0) {
1076 		if (strcmp(op, "STAT") == 0)
1077 			return (_http_request(url, "HEAD", us, purl, flags));
1078 		else if (strcmp(op, "RETR") == 0)
1079 			return (_http_request(url, "GET", us, purl, flags));
1080 		/*
1081 		 * Our HTTP code doesn't support PUT requests yet, so try
1082 		 * a direct connection.
1083 		 */
1084 	}
1085 
1086 	/* connect to server */
1087 	conn = _ftp_cached_connect(url, purl, flags);
1088 	if (purl)
1089 		fetchFreeURL(purl);
1090 	if (conn == NULL)
1091 		return (NULL);
1092 
1093 	/* change directory */
1094 	if (_ftp_cwd(conn, url->doc) == -1)
1095 		return (NULL);
1096 
1097 	/* stat file */
1098 	if (us && _ftp_stat(conn, url->doc, us) == -1
1099 	    && fetchLastErrCode != FETCH_PROTO
1100 	    && fetchLastErrCode != FETCH_UNAVAIL)
1101 		return (NULL);
1102 
1103 	/* just a stat */
1104 	if (strcmp(op, "STAT") == 0)
1105 		return (FILE *)1; /* bogus return value */
1106 	if (strcmp(op, "STOR") == 0 || strcmp(op, "APPE") == 0)
1107 		oflag = O_WRONLY;
1108 	else
1109 		oflag = O_RDONLY;
1110 
1111 	/* initiate the transfer */
1112 	return (_ftp_transfer(conn, op, url->doc, oflag, url->offset, flags));
1113 }
1114 
1115 /*
1116  * Get and stat file
1117  */
1118 FILE *
1119 fetchXGetFTP(struct url *url, struct url_stat *us, const char *flags)
1120 {
1121 	return (_ftp_request(url, "RETR", us, _ftp_get_proxy(flags), flags));
1122 }
1123 
1124 /*
1125  * Get file
1126  */
1127 FILE *
1128 fetchGetFTP(struct url *url, const char *flags)
1129 {
1130 	return (fetchXGetFTP(url, NULL, flags));
1131 }
1132 
1133 /*
1134  * Put file
1135  */
1136 FILE *
1137 fetchPutFTP(struct url *url, const char *flags)
1138 {
1139 
1140 	return (_ftp_request(url, CHECK_FLAG('a') ? "APPE" : "STOR", NULL,
1141 	    _ftp_get_proxy(flags), flags));
1142 }
1143 
1144 /*
1145  * Get file stats
1146  */
1147 int
1148 fetchStatFTP(struct url *url, struct url_stat *us, const char *flags)
1149 {
1150 	FILE *f;
1151 
1152 	f = _ftp_request(url, "STAT", us, _ftp_get_proxy(flags), flags);
1153 	if (f == NULL)
1154 		return (-1);
1155 	return (0);
1156 }
1157 
1158 /*
1159  * List a directory
1160  */
1161 struct url_ent *
1162 fetchListFTP(struct url *url __unused, const char *flags __unused)
1163 {
1164 	warnx("fetchListFTP(): not implemented");
1165 	return (NULL);
1166 }
1167