xref: /freebsd/lib/libfetch/ftp.c (revision 87569f75a91f298c52a71823c04d41cf53c88889)
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 		for (++i; file + i < end && file[i] != '/'; ++i)
298 			/* nothing */ ;
299 		e = _ftp_cmd(conn, "CWD %.*s", file + i - beg, beg);
300 		if (e != FTP_FILE_ACTION_OK) {
301 			_ftp_seterr(e);
302 			return (-1);
303 		}
304 	}
305 	return (0);
306 }
307 
308 /*
309  * Set transfer mode and data type
310  */
311 static int
312 _ftp_mode_type(conn_t *conn, int mode, int type)
313 {
314 	int e;
315 
316 	switch (mode) {
317 	case 0:
318 	case 's':
319 		mode = 'S';
320 	case 'S':
321 		break;
322 	default:
323 		return (FTP_PROTOCOL_ERROR);
324 	}
325 	if ((e = _ftp_cmd(conn, "MODE %c", mode)) != FTP_OK) {
326 		if (mode == 'S') {
327 			/*
328 			 * Stream mode is supposed to be the default - so
329 			 * much so that some servers not only do not
330 			 * support any other mode, but do not support the
331 			 * MODE command at all.
332 			 *
333 			 * If "MODE S" fails, it is unlikely that we
334 			 * previously succeeded in setting a different
335 			 * mode.  Therefore, we simply hope that the
336 			 * server is already in the correct mode, and
337 			 * silently ignore the failure.
338 			 */
339 		} else {
340 			return (e);
341 		}
342 	}
343 
344 	switch (type) {
345 	case 0:
346 	case 'i':
347 		type = 'I';
348 	case 'I':
349 		break;
350 	case 'a':
351 		type = 'A';
352 	case 'A':
353 		break;
354 	case 'd':
355 		type = 'D';
356 	case 'D':
357 		/* can't handle yet */
358 	default:
359 		return (FTP_PROTOCOL_ERROR);
360 	}
361 	if ((e = _ftp_cmd(conn, "TYPE %c", type)) != FTP_OK)
362 		return (e);
363 
364 	return (FTP_OK);
365 }
366 
367 /*
368  * Request and parse file stats
369  */
370 static int
371 _ftp_stat(conn_t *conn, const char *file, struct url_stat *us)
372 {
373 	char *ln;
374 	const char *filename;
375 	int filenamelen, type;
376 	struct tm tm;
377 	time_t t;
378 	int e;
379 
380 	us->size = -1;
381 	us->atime = us->mtime = 0;
382 
383 	filename = _ftp_filename(file, &filenamelen, &type);
384 
385 	if ((e = _ftp_mode_type(conn, 0, type)) != FTP_OK) {
386 		_ftp_seterr(e);
387 		return (-1);
388 	}
389 
390 	e = _ftp_cmd(conn, "SIZE %.*s", filenamelen, filename);
391 	if (e != FTP_FILE_STATUS) {
392 		_ftp_seterr(e);
393 		return (-1);
394 	}
395 	for (ln = conn->buf + 4; *ln && isspace(*ln); ln++)
396 		/* nothing */ ;
397 	for (us->size = 0; *ln && isdigit(*ln); ln++)
398 		us->size = us->size * 10 + *ln - '0';
399 	if (*ln && !isspace(*ln)) {
400 		_ftp_seterr(FTP_PROTOCOL_ERROR);
401 		us->size = -1;
402 		return (-1);
403 	}
404 	if (us->size == 0)
405 		us->size = -1;
406 	DEBUG(fprintf(stderr, "size: [%lld]\n", (long long)us->size));
407 
408 	e = _ftp_cmd(conn, "MDTM %.*s", filenamelen, filename);
409 	if (e != FTP_FILE_STATUS) {
410 		_ftp_seterr(e);
411 		return (-1);
412 	}
413 	for (ln = conn->buf + 4; *ln && isspace(*ln); ln++)
414 		/* nothing */ ;
415 	switch (strspn(ln, "0123456789")) {
416 	case 14:
417 		break;
418 	case 15:
419 		ln++;
420 		ln[0] = '2';
421 		ln[1] = '0';
422 		break;
423 	default:
424 		_ftp_seterr(FTP_PROTOCOL_ERROR);
425 		return (-1);
426 	}
427 	if (sscanf(ln, "%04d%02d%02d%02d%02d%02d",
428 	    &tm.tm_year, &tm.tm_mon, &tm.tm_mday,
429 	    &tm.tm_hour, &tm.tm_min, &tm.tm_sec) != 6) {
430 		_ftp_seterr(FTP_PROTOCOL_ERROR);
431 		return (-1);
432 	}
433 	tm.tm_mon--;
434 	tm.tm_year -= 1900;
435 	tm.tm_isdst = -1;
436 	t = timegm(&tm);
437 	if (t == (time_t)-1)
438 		t = time(NULL);
439 	us->mtime = t;
440 	us->atime = t;
441 	DEBUG(fprintf(stderr,
442 	    "last modified: [%04d-%02d-%02d %02d:%02d:%02d]\n",
443 	    tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
444 	    tm.tm_hour, tm.tm_min, tm.tm_sec));
445 	return (0);
446 }
447 
448 /*
449  * I/O functions for FTP
450  */
451 struct ftpio {
452 	conn_t	*cconn;		/* Control connection */
453 	conn_t	*dconn;		/* Data connection */
454 	int	 dir;		/* Direction */
455 	int	 eof;		/* EOF reached */
456 	int	 err;		/* Error code */
457 };
458 
459 static int	 _ftp_readfn(void *, char *, int);
460 static int	 _ftp_writefn(void *, const char *, int);
461 static fpos_t	 _ftp_seekfn(void *, fpos_t, int);
462 static int	 _ftp_closefn(void *);
463 
464 static int
465 _ftp_readfn(void *v, char *buf, int len)
466 {
467 	struct ftpio *io;
468 	int r;
469 
470 	io = (struct ftpio *)v;
471 	if (io == NULL) {
472 		errno = EBADF;
473 		return (-1);
474 	}
475 	if (io->cconn == NULL || io->dconn == NULL || io->dir == O_WRONLY) {
476 		errno = EBADF;
477 		return (-1);
478 	}
479 	if (io->err) {
480 		errno = io->err;
481 		return (-1);
482 	}
483 	if (io->eof)
484 		return (0);
485 	r = _fetch_read(io->dconn, buf, len);
486 	if (r > 0)
487 		return (r);
488 	if (r == 0) {
489 		io->eof = 1;
490 		return (0);
491 	}
492 	if (errno != EINTR)
493 		io->err = errno;
494 	return (-1);
495 }
496 
497 static int
498 _ftp_writefn(void *v, const char *buf, int len)
499 {
500 	struct ftpio *io;
501 	int w;
502 
503 	io = (struct ftpio *)v;
504 	if (io == NULL) {
505 		errno = EBADF;
506 		return (-1);
507 	}
508 	if (io->cconn == NULL || io->dconn == NULL || io->dir == O_RDONLY) {
509 		errno = EBADF;
510 		return (-1);
511 	}
512 	if (io->err) {
513 		errno = io->err;
514 		return (-1);
515 	}
516 	w = _fetch_write(io->dconn, buf, len);
517 	if (w >= 0)
518 		return (w);
519 	if (errno != EINTR)
520 		io->err = errno;
521 	return (-1);
522 }
523 
524 static fpos_t
525 _ftp_seekfn(void *v, fpos_t pos __unused, int whence __unused)
526 {
527 	struct ftpio *io;
528 
529 	io = (struct ftpio *)v;
530 	if (io == NULL) {
531 		errno = EBADF;
532 		return (-1);
533 	}
534 	errno = ESPIPE;
535 	return (-1);
536 }
537 
538 static int
539 _ftp_closefn(void *v)
540 {
541 	struct ftpio *io;
542 	int r;
543 
544 	io = (struct ftpio *)v;
545 	if (io == NULL) {
546 		errno = EBADF;
547 		return (-1);
548 	}
549 	if (io->dir == -1)
550 		return (0);
551 	if (io->cconn == NULL || io->dconn == NULL) {
552 		errno = EBADF;
553 		return (-1);
554 	}
555 	_fetch_close(io->dconn);
556 	io->dir = -1;
557 	io->dconn = NULL;
558 	DEBUG(fprintf(stderr, "Waiting for final status\n"));
559 	r = _ftp_chkerr(io->cconn);
560 	if (io->cconn == cached_connection && io->cconn->ref == 1)
561 		cached_connection = NULL;
562 	_fetch_close(io->cconn);
563 	free(io);
564 	return (r == FTP_TRANSFER_COMPLETE) ? 0 : -1;
565 }
566 
567 static FILE *
568 _ftp_setup(conn_t *cconn, conn_t *dconn, int mode)
569 {
570 	struct ftpio *io;
571 	FILE *f;
572 
573 	if (cconn == NULL || dconn == NULL)
574 		return (NULL);
575 	if ((io = malloc(sizeof(*io))) == NULL)
576 		return (NULL);
577 	io->cconn = cconn;
578 	io->dconn = dconn;
579 	io->dir = mode;
580 	io->eof = io->err = 0;
581 	f = funopen(io, _ftp_readfn, _ftp_writefn, _ftp_seekfn, _ftp_closefn);
582 	if (f == NULL)
583 		free(io);
584 	return (f);
585 }
586 
587 /*
588  * Transfer file
589  */
590 static FILE *
591 _ftp_transfer(conn_t *conn, const char *oper, const char *file,
592     int mode, off_t offset, const char *flags)
593 {
594 	struct sockaddr_storage sa;
595 	struct sockaddr_in6 *sin6;
596 	struct sockaddr_in *sin4;
597 	const char *filename;
598 	int filenamelen, type;
599 	int low, pasv, verbose;
600 	int e, sd = -1;
601 	socklen_t l;
602 	char *s;
603 	FILE *df;
604 
605 	/* check flags */
606 	low = CHECK_FLAG('l');
607 	pasv = CHECK_FLAG('p');
608 	verbose = CHECK_FLAG('v');
609 
610 	/* passive mode */
611 	if (!pasv)
612 		pasv = ((s = getenv("FTP_PASSIVE_MODE")) != NULL &&
613 		    strncasecmp(s, "no", 2) != 0);
614 
615 	/* isolate filename */
616 	filename = _ftp_filename(file, &filenamelen, &type);
617 
618 	/* set transfer mode and data type */
619 	if ((e = _ftp_mode_type(conn, 0, type)) != FTP_OK)
620 		goto ouch;
621 
622 	/* find our own address, bind, and listen */
623 	l = sizeof(sa);
624 	if (getsockname(conn->sd, (struct sockaddr *)&sa, &l) == -1)
625 		goto sysouch;
626 	if (sa.ss_family == AF_INET6)
627 		unmappedaddr((struct sockaddr_in6 *)&sa);
628 
629 	/* open data socket */
630 	if ((sd = socket(sa.ss_family, SOCK_STREAM, IPPROTO_TCP)) == -1) {
631 		_fetch_syserr();
632 		return (NULL);
633 	}
634 
635 	if (pasv) {
636 		u_char addr[64];
637 		char *ln, *p;
638 		unsigned int i;
639 		int port;
640 
641 		/* send PASV command */
642 		if (verbose)
643 			_fetch_info("setting passive mode");
644 		switch (sa.ss_family) {
645 		case AF_INET:
646 			if ((e = _ftp_cmd(conn, "PASV")) != FTP_PASSIVE_MODE)
647 				goto ouch;
648 			break;
649 		case AF_INET6:
650 			if ((e = _ftp_cmd(conn, "EPSV")) != FTP_EPASSIVE_MODE) {
651 				if (e == -1)
652 					goto ouch;
653 				if ((e = _ftp_cmd(conn, "LPSV")) !=
654 				    FTP_LPASSIVE_MODE)
655 					goto ouch;
656 			}
657 			break;
658 		default:
659 			e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
660 			goto ouch;
661 		}
662 
663 		/*
664 		 * Find address and port number. The reply to the PASV command
665 		 * is IMHO the one and only weak point in the FTP protocol.
666 		 */
667 		ln = conn->buf;
668 		switch (e) {
669 		case FTP_PASSIVE_MODE:
670 		case FTP_LPASSIVE_MODE:
671 			for (p = ln + 3; *p && !isdigit(*p); p++)
672 				/* nothing */ ;
673 			if (!*p) {
674 				e = FTP_PROTOCOL_ERROR;
675 				goto ouch;
676 			}
677 			l = (e == FTP_PASSIVE_MODE ? 6 : 21);
678 			for (i = 0; *p && i < l; i++, p++)
679 				addr[i] = strtol(p, &p, 10);
680 			if (i < l) {
681 				e = FTP_PROTOCOL_ERROR;
682 				goto ouch;
683 			}
684 			break;
685 		case FTP_EPASSIVE_MODE:
686 			for (p = ln + 3; *p && *p != '('; p++)
687 				/* nothing */ ;
688 			if (!*p) {
689 				e = FTP_PROTOCOL_ERROR;
690 				goto ouch;
691 			}
692 			++p;
693 			if (sscanf(p, "%c%c%c%d%c", &addr[0], &addr[1], &addr[2],
694 				&port, &addr[3]) != 5 ||
695 			    addr[0] != addr[1] ||
696 			    addr[0] != addr[2] || addr[0] != addr[3]) {
697 				e = FTP_PROTOCOL_ERROR;
698 				goto ouch;
699 			}
700 			break;
701 		}
702 
703 		/* seek to required offset */
704 		if (offset)
705 			if (_ftp_cmd(conn, "REST %lu", (u_long)offset) != FTP_FILE_OK)
706 				goto sysouch;
707 
708 		/* construct sockaddr for data socket */
709 		l = sizeof(sa);
710 		if (getpeername(conn->sd, (struct sockaddr *)&sa, &l) == -1)
711 			goto sysouch;
712 		if (sa.ss_family == AF_INET6)
713 			unmappedaddr((struct sockaddr_in6 *)&sa);
714 		switch (sa.ss_family) {
715 		case AF_INET6:
716 			sin6 = (struct sockaddr_in6 *)&sa;
717 			if (e == FTP_EPASSIVE_MODE)
718 				sin6->sin6_port = htons(port);
719 			else {
720 				bcopy(addr + 2, (char *)&sin6->sin6_addr, 16);
721 				bcopy(addr + 19, (char *)&sin6->sin6_port, 2);
722 			}
723 			break;
724 		case AF_INET:
725 			sin4 = (struct sockaddr_in *)&sa;
726 			if (e == FTP_EPASSIVE_MODE)
727 				sin4->sin_port = htons(port);
728 			else {
729 				bcopy(addr, (char *)&sin4->sin_addr, 4);
730 				bcopy(addr + 4, (char *)&sin4->sin_port, 2);
731 			}
732 			break;
733 		default:
734 			e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
735 			break;
736 		}
737 
738 		/* connect to data port */
739 		if (verbose)
740 			_fetch_info("opening data connection");
741 		if (connect(sd, (struct sockaddr *)&sa, sa.ss_len) == -1)
742 			goto sysouch;
743 
744 		/* make the server initiate the transfer */
745 		if (verbose)
746 			_fetch_info("initiating transfer");
747 		e = _ftp_cmd(conn, "%s %.*s", oper, filenamelen, filename);
748 		if (e != FTP_CONNECTION_ALREADY_OPEN && e != FTP_OPEN_DATA_CONNECTION)
749 			goto ouch;
750 
751 	} else {
752 		u_int32_t a;
753 		u_short p;
754 		int arg, d;
755 		char *ap;
756 		char hname[INET6_ADDRSTRLEN];
757 
758 		switch (sa.ss_family) {
759 		case AF_INET6:
760 			((struct sockaddr_in6 *)&sa)->sin6_port = 0;
761 #ifdef IPV6_PORTRANGE
762 			arg = low ? IPV6_PORTRANGE_DEFAULT : IPV6_PORTRANGE_HIGH;
763 			if (setsockopt(sd, IPPROTO_IPV6, IPV6_PORTRANGE,
764 				(char *)&arg, sizeof(arg)) == -1)
765 				goto sysouch;
766 #endif
767 			break;
768 		case AF_INET:
769 			((struct sockaddr_in *)&sa)->sin_port = 0;
770 			arg = low ? IP_PORTRANGE_DEFAULT : IP_PORTRANGE_HIGH;
771 			if (setsockopt(sd, IPPROTO_IP, IP_PORTRANGE,
772 				(char *)&arg, sizeof(arg)) == -1)
773 				goto sysouch;
774 			break;
775 		}
776 		if (verbose)
777 			_fetch_info("binding data socket");
778 		if (bind(sd, (struct sockaddr *)&sa, sa.ss_len) == -1)
779 			goto sysouch;
780 		if (listen(sd, 1) == -1)
781 			goto sysouch;
782 
783 		/* find what port we're on and tell the server */
784 		if (getsockname(sd, (struct sockaddr *)&sa, &l) == -1)
785 			goto sysouch;
786 		switch (sa.ss_family) {
787 		case AF_INET:
788 			sin4 = (struct sockaddr_in *)&sa;
789 			a = ntohl(sin4->sin_addr.s_addr);
790 			p = ntohs(sin4->sin_port);
791 			e = _ftp_cmd(conn, "PORT %d,%d,%d,%d,%d,%d",
792 			    (a >> 24) & 0xff, (a >> 16) & 0xff,
793 			    (a >> 8) & 0xff, a & 0xff,
794 			    (p >> 8) & 0xff, p & 0xff);
795 			break;
796 		case AF_INET6:
797 #define UC(b)	(((int)b)&0xff)
798 			e = -1;
799 			sin6 = (struct sockaddr_in6 *)&sa;
800 			sin6->sin6_scope_id = 0;
801 			if (getnameinfo((struct sockaddr *)&sa, sa.ss_len,
802 				hname, sizeof(hname),
803 				NULL, 0, NI_NUMERICHOST) == 0) {
804 				e = _ftp_cmd(conn, "EPRT |%d|%s|%d|", 2, hname,
805 				    htons(sin6->sin6_port));
806 				if (e == -1)
807 					goto ouch;
808 			}
809 			if (e != FTP_OK) {
810 				ap = (char *)&sin6->sin6_addr;
811 				e = _ftp_cmd(conn,
812 				    "LPRT %d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d",
813 				    6, 16,
814 				    UC(ap[0]), UC(ap[1]), UC(ap[2]), UC(ap[3]),
815 				    UC(ap[4]), UC(ap[5]), UC(ap[6]), UC(ap[7]),
816 				    UC(ap[8]), UC(ap[9]), UC(ap[10]), UC(ap[11]),
817 				    UC(ap[12]), UC(ap[13]), UC(ap[14]), UC(ap[15]),
818 				    2,
819 				    (ntohs(sin6->sin6_port) >> 8) & 0xff,
820 				    ntohs(sin6->sin6_port)        & 0xff);
821 			}
822 			break;
823 		default:
824 			e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
825 			goto ouch;
826 		}
827 		if (e != FTP_OK)
828 			goto ouch;
829 
830 		/* seek to required offset */
831 		if (offset)
832 			if (_ftp_cmd(conn, "REST %ju", (uintmax_t)offset) != FTP_FILE_OK)
833 				goto sysouch;
834 
835 		/* make the server initiate the transfer */
836 		if (verbose)
837 			_fetch_info("initiating transfer");
838 		e = _ftp_cmd(conn, "%s %.*s", oper, filenamelen, filename);
839 		if (e != FTP_CONNECTION_ALREADY_OPEN && e != FTP_OPEN_DATA_CONNECTION)
840 			goto ouch;
841 
842 		/* accept the incoming connection and go to town */
843 		if ((d = accept(sd, NULL, NULL)) == -1)
844 			goto sysouch;
845 		close(sd);
846 		sd = d;
847 	}
848 
849 	if ((df = _ftp_setup(conn, _fetch_reopen(sd), mode)) == NULL)
850 		goto sysouch;
851 	return (df);
852 
853 sysouch:
854 	_fetch_syserr();
855 	if (sd >= 0)
856 		close(sd);
857 	return (NULL);
858 
859 ouch:
860 	if (e != -1)
861 		_ftp_seterr(e);
862 	if (sd >= 0)
863 		close(sd);
864 	return (NULL);
865 }
866 
867 /*
868  * Authenticate
869  */
870 static int
871 _ftp_authenticate(conn_t *conn, struct url *url, struct url *purl)
872 {
873 	const char *user, *pwd, *logname;
874 	char pbuf[MAXHOSTNAMELEN + MAXLOGNAME + 1];
875 	int e, len;
876 
877 	/* XXX FTP_AUTH, and maybe .netrc */
878 
879 	/* send user name and password */
880 	if (url->user[0] == '\0')
881 		_fetch_netrc_auth(url);
882 	user = url->user;
883 	if (*user == '\0')
884 		user = getenv("FTP_LOGIN");
885 	if (user == NULL || *user == '\0')
886 		user = FTP_ANONYMOUS_USER;
887 	if (purl && url->port == _fetch_default_port(url->scheme))
888 		e = _ftp_cmd(conn, "USER %s@%s", user, url->host);
889 	else if (purl)
890 		e = _ftp_cmd(conn, "USER %s@%s@%d", user, url->host, url->port);
891 	else
892 		e = _ftp_cmd(conn, "USER %s", user);
893 
894 	/* did the server request a password? */
895 	if (e == FTP_NEED_PASSWORD) {
896 		pwd = url->pwd;
897 		if (*pwd == '\0')
898 			pwd = getenv("FTP_PASSWORD");
899 		if (pwd == NULL || *pwd == '\0') {
900 			if ((logname = getlogin()) == 0)
901 				logname = FTP_ANONYMOUS_USER;
902 			if ((len = snprintf(pbuf, MAXLOGNAME + 1, "%s@", logname)) < 0)
903 				len = 0;
904 			else if (len > MAXLOGNAME)
905 				len = MAXLOGNAME;
906 			gethostname(pbuf + len, sizeof(pbuf) - len);
907 			pwd = pbuf;
908 		}
909 		e = _ftp_cmd(conn, "PASS %s", pwd);
910 	}
911 
912 	return (e);
913 }
914 
915 /*
916  * Log on to FTP server
917  */
918 static conn_t *
919 _ftp_connect(struct url *url, struct url *purl, const char *flags)
920 {
921 	conn_t *conn;
922 	int e, direct, verbose;
923 #ifdef INET6
924 	int af = AF_UNSPEC;
925 #else
926 	int af = AF_INET;
927 #endif
928 
929 	direct = CHECK_FLAG('d');
930 	verbose = CHECK_FLAG('v');
931 	if (CHECK_FLAG('4'))
932 		af = AF_INET;
933 	else if (CHECK_FLAG('6'))
934 		af = AF_INET6;
935 
936 	if (direct)
937 		purl = NULL;
938 
939 	/* check for proxy */
940 	if (purl) {
941 		/* XXX proxy authentication! */
942 		conn = _fetch_connect(purl->host, purl->port, af, verbose);
943 	} else {
944 		/* no proxy, go straight to target */
945 		conn = _fetch_connect(url->host, url->port, af, verbose);
946 		purl = NULL;
947 	}
948 
949 	/* check connection */
950 	if (conn == NULL)
951 		/* _fetch_connect() has already set an error code */
952 		return (NULL);
953 
954 	/* expect welcome message */
955 	if ((e = _ftp_chkerr(conn)) != FTP_SERVICE_READY)
956 		goto fouch;
957 
958 	/* authenticate */
959 	if ((e = _ftp_authenticate(conn, url, purl)) != FTP_LOGGED_IN)
960 		goto fouch;
961 
962 	/* done */
963 	return (conn);
964 
965 fouch:
966 	if (e != -1)
967 		_ftp_seterr(e);
968 	_fetch_close(conn);
969 	return (NULL);
970 }
971 
972 /*
973  * Disconnect from server
974  */
975 static void
976 _ftp_disconnect(conn_t *conn)
977 {
978 	(void)_ftp_cmd(conn, "QUIT");
979 	if (conn == cached_connection && conn->ref == 1)
980 		cached_connection = NULL;
981 	_fetch_close(conn);
982 }
983 
984 /*
985  * Check if we're already connected
986  */
987 static int
988 _ftp_isconnected(struct url *url)
989 {
990 	return (cached_connection
991 	    && (strcmp(url->host, cached_host.host) == 0)
992 	    && (strcmp(url->user, cached_host.user) == 0)
993 	    && (strcmp(url->pwd, cached_host.pwd) == 0)
994 	    && (url->port == cached_host.port));
995 }
996 
997 /*
998  * Check the cache, reconnect if no luck
999  */
1000 static conn_t *
1001 _ftp_cached_connect(struct url *url, struct url *purl, const char *flags)
1002 {
1003 	conn_t *conn;
1004 	int e;
1005 
1006 	/* set default port */
1007 	if (!url->port)
1008 		url->port = _fetch_default_port(url->scheme);
1009 
1010 	/* try to use previously cached connection */
1011 	if (_ftp_isconnected(url)) {
1012 		e = _ftp_cmd(cached_connection, "NOOP");
1013 		if (e == FTP_OK || e == FTP_SYNTAX_ERROR)
1014 			return (_fetch_ref(cached_connection));
1015 	}
1016 
1017 	/* connect to server */
1018 	if ((conn = _ftp_connect(url, purl, flags)) == NULL)
1019 		return (NULL);
1020 	if (cached_connection)
1021 		_ftp_disconnect(cached_connection);
1022 	cached_connection = _fetch_ref(conn);
1023 	memcpy(&cached_host, url, sizeof(*url));
1024 	return (conn);
1025 }
1026 
1027 /*
1028  * Check the proxy settings
1029  */
1030 static struct url *
1031 _ftp_get_proxy(const char *flags)
1032 {
1033 	struct url *purl;
1034 	char *p;
1035 
1036 	if (flags != NULL && strchr(flags, 'd') != NULL)
1037 		return (NULL);
1038 	if (((p = getenv("FTP_PROXY")) || (p = getenv("ftp_proxy")) ||
1039 		(p = getenv("HTTP_PROXY")) || (p = getenv("http_proxy"))) &&
1040 	    *p && (purl = fetchParseURL(p)) != NULL) {
1041 		if (!*purl->scheme) {
1042 			if (getenv("FTP_PROXY") || getenv("ftp_proxy"))
1043 				strcpy(purl->scheme, SCHEME_FTP);
1044 			else
1045 				strcpy(purl->scheme, SCHEME_HTTP);
1046 		}
1047 		if (!purl->port)
1048 			purl->port = _fetch_default_proxy_port(purl->scheme);
1049 		if (strcasecmp(purl->scheme, SCHEME_FTP) == 0 ||
1050 		    strcasecmp(purl->scheme, SCHEME_HTTP) == 0)
1051 			return (purl);
1052 		fetchFreeURL(purl);
1053 	}
1054 	return (NULL);
1055 }
1056 
1057 /*
1058  * Process an FTP request
1059  */
1060 FILE *
1061 _ftp_request(struct url *url, const char *op, struct url_stat *us,
1062     struct url *purl, const char *flags)
1063 {
1064 	conn_t *conn;
1065 	int oflag;
1066 
1067 	/* check if we should use HTTP instead */
1068 	if (purl && strcasecmp(purl->scheme, SCHEME_HTTP) == 0) {
1069 		if (strcmp(op, "STAT") == 0)
1070 			return (_http_request(url, "HEAD", us, purl, flags));
1071 		else if (strcmp(op, "RETR") == 0)
1072 			return (_http_request(url, "GET", us, purl, flags));
1073 		/*
1074 		 * Our HTTP code doesn't support PUT requests yet, so try
1075 		 * a direct connection.
1076 		 */
1077 	}
1078 
1079 	/* connect to server */
1080 	conn = _ftp_cached_connect(url, purl, flags);
1081 	if (purl)
1082 		fetchFreeURL(purl);
1083 	if (conn == NULL)
1084 		return (NULL);
1085 
1086 	/* change directory */
1087 	if (_ftp_cwd(conn, url->doc) == -1)
1088 		return (NULL);
1089 
1090 	/* stat file */
1091 	if (us && _ftp_stat(conn, url->doc, us) == -1
1092 	    && fetchLastErrCode != FETCH_PROTO
1093 	    && fetchLastErrCode != FETCH_UNAVAIL)
1094 		return (NULL);
1095 
1096 	/* just a stat */
1097 	if (strcmp(op, "STAT") == 0)
1098 		return (FILE *)1; /* bogus return value */
1099 	if (strcmp(op, "STOR") == 0 || strcmp(op, "APPE") == 0)
1100 		oflag = O_WRONLY;
1101 	else
1102 		oflag = O_RDONLY;
1103 
1104 	/* initiate the transfer */
1105 	return (_ftp_transfer(conn, op, url->doc, oflag, url->offset, flags));
1106 }
1107 
1108 /*
1109  * Get and stat file
1110  */
1111 FILE *
1112 fetchXGetFTP(struct url *url, struct url_stat *us, const char *flags)
1113 {
1114 	return (_ftp_request(url, "RETR", us, _ftp_get_proxy(flags), flags));
1115 }
1116 
1117 /*
1118  * Get file
1119  */
1120 FILE *
1121 fetchGetFTP(struct url *url, const char *flags)
1122 {
1123 	return (fetchXGetFTP(url, NULL, flags));
1124 }
1125 
1126 /*
1127  * Put file
1128  */
1129 FILE *
1130 fetchPutFTP(struct url *url, const char *flags)
1131 {
1132 
1133 	return (_ftp_request(url, CHECK_FLAG('a') ? "APPE" : "STOR", NULL,
1134 	    _ftp_get_proxy(flags), flags));
1135 }
1136 
1137 /*
1138  * Get file stats
1139  */
1140 int
1141 fetchStatFTP(struct url *url, struct url_stat *us, const char *flags)
1142 {
1143 	FILE *f;
1144 
1145 	f = _ftp_request(url, "STAT", us, _ftp_get_proxy(flags), flags);
1146 	if (f == NULL)
1147 		return (-1);
1148 	return (0);
1149 }
1150 
1151 /*
1152  * List a directory
1153  */
1154 struct url_ent *
1155 fetchListFTP(struct url *url __unused, const char *flags __unused)
1156 {
1157 	warnx("fetchListFTP(): not implemented");
1158 	return (NULL);
1159 }
1160