xref: /freebsd/lib/libfetch/ftp.c (revision 6de306ecee3831f48debaad1d0b22418faa48e10)
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  * $FreeBSD$
29  */
30 
31 /*
32  * Portions of this code were taken from or based on ftpio.c:
33  *
34  * ----------------------------------------------------------------------------
35  * "THE BEER-WARE LICENSE" (Revision 42):
36  * <phk@login.dknet.dk> wrote this file.  As long as you retain this notice you
37  * can do whatever you want with this stuff. If we meet some day, and you think
38  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
39  * ----------------------------------------------------------------------------
40  *
41  * Major Changelog:
42  *
43  * Dag-Erling Co�dan Sm�rgrav
44  * 9 Jun 1998
45  *
46  * Incorporated into libfetch
47  *
48  * Jordan K. Hubbard
49  * 17 Jan 1996
50  *
51  * Turned inside out. Now returns xfers as new file ids, not as a special
52  * `state' of FTP_t
53  *
54  * $ftpioId: ftpio.c,v 1.30 1998/04/11 07:28:53 phk Exp $
55  *
56  */
57 
58 #include <sys/param.h>
59 #include <sys/socket.h>
60 #include <netinet/in.h>
61 
62 #include <ctype.h>
63 #include <errno.h>
64 #include <fcntl.h>
65 #include <netdb.h>
66 #include <stdarg.h>
67 #include <stdio.h>
68 #include <stdlib.h>
69 #include <string.h>
70 #include <time.h>
71 #include <unistd.h>
72 
73 #include "fetch.h"
74 #include "common.h"
75 #include "ftperr.h"
76 
77 #define FTP_ANONYMOUS_USER	"anonymous"
78 
79 #define FTP_CONNECTION_ALREADY_OPEN	125
80 #define FTP_OPEN_DATA_CONNECTION	150
81 #define FTP_OK				200
82 #define FTP_FILE_STATUS			213
83 #define FTP_SERVICE_READY		220
84 #define FTP_TRANSFER_COMPLETE		226
85 #define FTP_PASSIVE_MODE		227
86 #define FTP_LPASSIVE_MODE		228
87 #define FTP_EPASSIVE_MODE		229
88 #define FTP_LOGGED_IN			230
89 #define FTP_FILE_ACTION_OK		250
90 #define FTP_NEED_PASSWORD		331
91 #define FTP_NEED_ACCOUNT		332
92 #define FTP_FILE_OK			350
93 #define FTP_SYNTAX_ERROR		500
94 #define FTP_PROTOCOL_ERROR		999
95 
96 static struct url cached_host;
97 static int cached_socket;
98 
99 static char *last_reply;
100 static size_t lr_size, lr_length;
101 static int last_code;
102 
103 #define isftpreply(foo) (isdigit(foo[0]) && isdigit(foo[1]) \
104 			 && isdigit(foo[2]) \
105                          && (foo[3] == ' ' || foo[3] == '\0'))
106 #define isftpinfo(foo) (isdigit(foo[0]) && isdigit(foo[1]) \
107 			&& isdigit(foo[2]) && foo[3] == '-')
108 
109 /* translate IPv4 mapped IPv6 address to IPv4 address */
110 static void
111 unmappedaddr(struct sockaddr_in6 *sin6)
112 {
113     struct sockaddr_in *sin4;
114     u_int32_t addr;
115     int port;
116 
117     if (sin6->sin6_family != AF_INET6 ||
118 	!IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
119 	return;
120     sin4 = (struct sockaddr_in *)sin6;
121     addr = *(u_int32_t *)&sin6->sin6_addr.s6_addr[12];
122     port = sin6->sin6_port;
123     memset(sin4, 0, sizeof(struct sockaddr_in));
124     sin4->sin_addr.s_addr = addr;
125     sin4->sin_port = port;
126     sin4->sin_family = AF_INET;
127     sin4->sin_len = sizeof(struct sockaddr_in);
128 }
129 
130 /*
131  * Get server response
132  */
133 static int
134 _ftp_chkerr(int cd)
135 {
136     if (_fetch_getln(cd, &last_reply, &lr_size, &lr_length) == -1) {
137 	_fetch_syserr();
138 	return -1;
139     }
140     if (isftpinfo(last_reply)) {
141 	while (lr_length && !isftpreply(last_reply)) {
142 	    if (_fetch_getln(cd, &last_reply, &lr_size, &lr_length) == -1) {
143 		_fetch_syserr();
144 		return -1;
145 	    }
146 	}
147     }
148 
149     while (lr_length && isspace(last_reply[lr_length-1]))
150 	lr_length--;
151     last_reply[lr_length] = 0;
152 
153     if (!isftpreply(last_reply)) {
154 	_ftp_seterr(FTP_PROTOCOL_ERROR);
155 	return -1;
156     }
157 
158     last_code = (last_reply[0] - '0') * 100
159 	+ (last_reply[1] - '0') * 10
160 	+ (last_reply[2] - '0');
161 
162     return last_code;
163 }
164 
165 /*
166  * Send a command and check reply
167  */
168 static int
169 _ftp_cmd(int cd, char *fmt, ...)
170 {
171     va_list ap;
172     size_t len;
173     char *msg;
174     int r;
175 
176     va_start(ap, fmt);
177     len = vasprintf(&msg, fmt, ap);
178     va_end(ap);
179 
180     if (msg == NULL) {
181 	errno = ENOMEM;
182 	_fetch_syserr();
183 	return -1;
184     }
185 
186     r = _fetch_putln(cd, msg, len);
187     free(msg);
188 
189     if (r == -1) {
190 	_fetch_syserr();
191 	return -1;
192     }
193 
194     return _ftp_chkerr(cd);
195 }
196 
197 /*
198  * Return a pointer to the filename part of a path
199  */
200 static char *
201 _ftp_filename(char *file)
202 {
203     char *s;
204 
205     if ((s = strrchr(file, '/')) == NULL)
206 	return file;
207     else
208 	return s + 1;
209 }
210 
211 /*
212  * Change working directory to the directory that contains the
213  * specified file.
214  */
215 static int
216 _ftp_cwd(int cd, char *file)
217 {
218     char *s;
219     int e;
220 
221     if ((s = strrchr(file, '/')) == NULL || s == file) {
222 	e = _ftp_cmd(cd, "CWD /");
223     } else {
224 	e = _ftp_cmd(cd, "CWD %.*s", s - file, file);
225     }
226     if (e != FTP_FILE_ACTION_OK) {
227 	_ftp_seterr(e);
228 	return -1;
229     }
230     return 0;
231 }
232 
233 /*
234  * Request and parse file stats
235  */
236 static int
237 _ftp_stat(int cd, char *file, struct url_stat *us)
238 {
239     char *ln, *s;
240     struct tm tm;
241     time_t t;
242     int e;
243 
244     us->size = -1;
245     us->atime = us->mtime = 0;
246 
247     if ((s = strrchr(file, '/')) == NULL)
248 	s = file;
249     else
250 	++s;
251 
252     if ((e = _ftp_cmd(cd, "SIZE %s", s)) != FTP_FILE_STATUS) {
253 	_ftp_seterr(e);
254 	return -1;
255     }
256     for (ln = last_reply + 4; *ln && isspace(*ln); ln++)
257 	/* nothing */ ;
258     for (us->size = 0; *ln && isdigit(*ln); ln++)
259 	us->size = us->size * 10 + *ln - '0';
260     if (*ln && !isspace(*ln)) {
261 	_ftp_seterr(FTP_PROTOCOL_ERROR);
262 	return -1;
263     }
264     if (us->size == 0)
265 	us->size = -1;
266     DEBUG(fprintf(stderr, "size: [\033[1m%lld\033[m]\n", us->size));
267 
268     if ((e = _ftp_cmd(cd, "MDTM %s", s)) != FTP_FILE_STATUS) {
269 	_ftp_seterr(e);
270 	return -1;
271     }
272     for (ln = last_reply + 4; *ln && isspace(*ln); ln++)
273 	/* nothing */ ;
274     switch (strspn(ln, "0123456789")) {
275     case 14:
276 	break;
277     case 15:
278 	ln++;
279 	ln[0] = '2';
280 	ln[1] = '0';
281 	break;
282     default:
283 	_ftp_seterr(FTP_PROTOCOL_ERROR);
284 	return -1;
285     }
286     if (sscanf(ln, "%04d%02d%02d%02d%02d%02d",
287 	       &tm.tm_year, &tm.tm_mon, &tm.tm_mday,
288 	       &tm.tm_hour, &tm.tm_min, &tm.tm_sec) != 6) {
289 	_ftp_seterr(FTP_PROTOCOL_ERROR);
290 	return -1;
291     }
292     tm.tm_mon--;
293     tm.tm_year -= 1900;
294     tm.tm_isdst = -1;
295     t = timegm(&tm);
296     if (t == (time_t)-1)
297 	t = time(NULL);
298     us->mtime = t;
299     us->atime = t;
300     DEBUG(fprintf(stderr, "last modified: [\033[1m%04d-%02d-%02d "
301 		  "%02d:%02d:%02d\033[m]\n",
302 		  tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
303 		  tm.tm_hour, tm.tm_min, tm.tm_sec));
304     return 0;
305 }
306 
307 /*
308  * I/O functions for FTP
309  */
310 struct ftpio {
311     int		 csd;		/* Control socket descriptor */
312     int		 dsd;		/* Data socket descriptor */
313     int		 dir;		/* Direction */
314     int		 eof;		/* EOF reached */
315     int		 err;		/* Error code */
316 };
317 
318 static int	_ftp_readfn(void *, char *, int);
319 static int	_ftp_writefn(void *, const char *, int);
320 static fpos_t	_ftp_seekfn(void *, fpos_t, int);
321 static int	_ftp_closefn(void *);
322 
323 static int
324 _ftp_readfn(void *v, char *buf, int len)
325 {
326     struct ftpio *io;
327     int r;
328 
329     io = (struct ftpio *)v;
330     if (io == NULL) {
331 	errno = EBADF;
332 	return -1;
333     }
334     if (io->csd == -1 || io->dsd == -1 || io->dir == O_WRONLY) {
335 	errno = EBADF;
336 	return -1;
337     }
338     if (io->err) {
339 	errno = io->err;
340 	return -1;
341     }
342     if (io->eof)
343 	return 0;
344     r = read(io->dsd, buf, len);
345     if (r > 0)
346 	return r;
347     if (r == 0) {
348 	io->eof = 1;
349 	return _ftp_closefn(v);
350     }
351     io->err = errno;
352     return -1;
353 }
354 
355 static int
356 _ftp_writefn(void *v, const char *buf, int len)
357 {
358     struct ftpio *io;
359     int w;
360 
361     io = (struct ftpio *)v;
362     if (io == NULL) {
363 	errno = EBADF;
364 	return -1;
365     }
366     if (io->csd == -1 || io->dsd == -1 || io->dir == O_RDONLY) {
367 	errno = EBADF;
368 	return -1;
369     }
370     if (io->err) {
371 	errno = io->err;
372 	return -1;
373     }
374     w = write(io->dsd, buf, len);
375     if (w >= 0)
376 	return w;
377     io->err = errno;
378     return -1;
379 }
380 
381 static fpos_t
382 _ftp_seekfn(void *v, fpos_t pos, int whence)
383 {
384     struct ftpio *io;
385 
386     io = (struct ftpio *)v;
387     if (io == NULL) {
388 	errno = EBADF;
389 	return -1;
390     }
391     errno = ESPIPE;
392     return -1;
393 }
394 
395 static int
396 _ftp_closefn(void *v)
397 {
398     struct ftpio *io;
399     int r;
400 
401     io = (struct ftpio *)v;
402     if (io == NULL) {
403 	errno = EBADF;
404 	return -1;
405     }
406     if (io->dir == -1)
407 	return 0;
408     if (io->csd == -1 || io->dsd == -1) {
409 	errno = EBADF;
410 	return -1;
411     }
412     close(io->dsd);
413     io->dir = -1;
414     io->dsd = -1;
415     DEBUG(fprintf(stderr, "Waiting for final status\n"));
416     if ((r = _ftp_chkerr(io->csd)) != FTP_TRANSFER_COMPLETE)
417 	io->err = r;
418     else
419 	io->err = 0;
420     close(io->csd);
421     io->csd = -1;
422     return io->err ? -1 : 0;
423 }
424 
425 static FILE *
426 _ftp_setup(int csd, int dsd, int mode)
427 {
428     struct ftpio *io;
429     FILE *f;
430 
431     if ((io = malloc(sizeof *io)) == NULL)
432 	return NULL;
433     io->csd = dup(csd);
434     io->dsd = dsd;
435     io->dir = mode;
436     io->eof = io->err = 0;
437     f = funopen(io, _ftp_readfn, _ftp_writefn, _ftp_seekfn, _ftp_closefn);
438     if (f == NULL)
439 	free(io);
440     return f;
441 }
442 
443 /*
444  * Transfer file
445  */
446 static FILE *
447 _ftp_transfer(int cd, char *oper, char *file,
448 	      int mode, off_t offset, char *flags)
449 {
450     struct sockaddr_storage sin;
451     struct sockaddr_in6 *sin6;
452     struct sockaddr_in *sin4;
453     int pasv, high, verbose;
454     int e, sd = -1;
455     socklen_t l;
456     char *s;
457     FILE *df;
458 
459     /* check flags */
460     pasv = CHECK_FLAG('p');
461     high = CHECK_FLAG('h');
462     verbose = CHECK_FLAG('v');
463 
464     /* passive mode */
465     if (!pasv)
466 	pasv = ((s = getenv("FTP_PASSIVE_MODE")) != NULL &&
467 		strncasecmp(s, "no", 2) != 0);
468 
469     /* find our own address, bind, and listen */
470     l = sizeof sin;
471     if (getsockname(cd, (struct sockaddr *)&sin, &l) == -1)
472 	goto sysouch;
473     if (sin.ss_family == AF_INET6)
474 	unmappedaddr((struct sockaddr_in6 *)&sin);
475 
476     /* open data socket */
477     if ((sd = socket(sin.ss_family, SOCK_STREAM, IPPROTO_TCP)) == -1) {
478 	_fetch_syserr();
479 	return NULL;
480     }
481 
482     if (pasv) {
483 	u_char addr[64];
484 	char *ln, *p;
485 	int i;
486 	int port;
487 
488 	/* send PASV command */
489 	if (verbose)
490 	    _fetch_info("setting passive mode");
491 	switch (sin.ss_family) {
492 	case AF_INET:
493 	    if ((e = _ftp_cmd(cd, "PASV")) != FTP_PASSIVE_MODE)
494 		goto ouch;
495 	    break;
496 	case AF_INET6:
497 	    if ((e = _ftp_cmd(cd, "EPSV")) != FTP_EPASSIVE_MODE) {
498 		if (e == -1)
499 		    goto ouch;
500 		if ((e = _ftp_cmd(cd, "LPSV")) != FTP_LPASSIVE_MODE)
501 		    goto ouch;
502 	    }
503 	    break;
504 	default:
505 	    e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
506 	    goto ouch;
507 	}
508 
509 	/*
510 	 * Find address and port number. The reply to the PASV command
511          * is IMHO the one and only weak point in the FTP protocol.
512 	 */
513 	ln = last_reply;
514       	switch (e) {
515 	case FTP_PASSIVE_MODE:
516 	case FTP_LPASSIVE_MODE:
517 	    for (p = ln + 3; *p && !isdigit(*p); p++)
518 		/* nothing */ ;
519 	    if (!*p) {
520 		e = FTP_PROTOCOL_ERROR;
521 		goto ouch;
522 	    }
523 	    l = (e == FTP_PASSIVE_MODE ? 6 : 21);
524 	    for (i = 0; *p && i < l; i++, p++)
525 		addr[i] = strtol(p, &p, 10);
526 	    if (i < l) {
527 		e = FTP_PROTOCOL_ERROR;
528 		goto ouch;
529 	    }
530 	    break;
531 	case FTP_EPASSIVE_MODE:
532 	    for (p = ln + 3; *p && *p != '('; p++)
533 		/* nothing */ ;
534 	    if (!*p) {
535 		e = FTP_PROTOCOL_ERROR;
536 		goto ouch;
537 	    }
538 	    ++p;
539 	    if (sscanf(p, "%c%c%c%d%c", &addr[0], &addr[1], &addr[2],
540 		       &port, &addr[3]) != 5 ||
541 		addr[0] != addr[1] ||
542 		addr[0] != addr[2] || addr[0] != addr[3]) {
543 		e = FTP_PROTOCOL_ERROR;
544 		goto ouch;
545 	    }
546 	    break;
547 	}
548 
549 	/* seek to required offset */
550 	if (offset)
551 	    if (_ftp_cmd(cd, "REST %lu", (u_long)offset) != FTP_FILE_OK)
552 		goto sysouch;
553 
554 	/* construct sockaddr for data socket */
555 	l = sizeof sin;
556 	if (getpeername(cd, (struct sockaddr *)&sin, &l) == -1)
557 	    goto sysouch;
558 	if (sin.ss_family == AF_INET6)
559 	    unmappedaddr((struct sockaddr_in6 *)&sin);
560 	switch (sin.ss_family) {
561 	case AF_INET6:
562 	    sin6 = (struct sockaddr_in6 *)&sin;
563 	    if (e == FTP_EPASSIVE_MODE)
564 		sin6->sin6_port = htons(port);
565 	    else {
566 		bcopy(addr + 2, (char *)&sin6->sin6_addr, 16);
567 		bcopy(addr + 19, (char *)&sin6->sin6_port, 2);
568 	    }
569 	    break;
570 	case AF_INET:
571 	    sin4 = (struct sockaddr_in *)&sin;
572 	    if (e == FTP_EPASSIVE_MODE)
573 		sin4->sin_port = htons(port);
574 	    else {
575 		bcopy(addr, (char *)&sin4->sin_addr, 4);
576 		bcopy(addr + 4, (char *)&sin4->sin_port, 2);
577 	    }
578 	    break;
579 	default:
580 	    e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
581 	    break;
582 	}
583 
584 	/* connect to data port */
585 	if (verbose)
586 	    _fetch_info("opening data connection");
587 	if (connect(sd, (struct sockaddr *)&sin, sin.ss_len) == -1)
588 	    goto sysouch;
589 
590 	/* make the server initiate the transfer */
591 	if (verbose)
592 	    _fetch_info("initiating transfer");
593 	e = _ftp_cmd(cd, "%s %s", oper, _ftp_filename(file));
594 	if (e != FTP_CONNECTION_ALREADY_OPEN && e != FTP_OPEN_DATA_CONNECTION)
595 	    goto ouch;
596 
597     } else {
598 	u_int32_t a;
599 	u_short p;
600 	int arg, d;
601 	char *ap;
602 	char hname[INET6_ADDRSTRLEN];
603 
604 	switch (sin.ss_family) {
605 	case AF_INET6:
606 	    ((struct sockaddr_in6 *)&sin)->sin6_port = 0;
607 #ifdef IPV6_PORTRANGE
608 	    arg = high ? IPV6_PORTRANGE_HIGH : IPV6_PORTRANGE_DEFAULT;
609 	    if (setsockopt(sd, IPPROTO_IPV6, IPV6_PORTRANGE,
610 			   (char *)&arg, sizeof(arg)) == -1)
611 		goto sysouch;
612 #endif
613 	    break;
614 	case AF_INET:
615 	    ((struct sockaddr_in *)&sin)->sin_port = 0;
616 	    arg = high ? IP_PORTRANGE_HIGH : IP_PORTRANGE_DEFAULT;
617 	    if (setsockopt(sd, IPPROTO_IP, IP_PORTRANGE,
618 			   (char *)&arg, sizeof arg) == -1)
619 		goto sysouch;
620 	    break;
621 	}
622 	if (verbose)
623 	    _fetch_info("binding data socket");
624 	if (bind(sd, (struct sockaddr *)&sin, sin.ss_len) == -1)
625 	    goto sysouch;
626 	if (listen(sd, 1) == -1)
627 	    goto sysouch;
628 
629 	/* find what port we're on and tell the server */
630 	if (getsockname(sd, (struct sockaddr *)&sin, &l) == -1)
631 	    goto sysouch;
632 	switch (sin.ss_family) {
633 	case AF_INET:
634 	    sin4 = (struct sockaddr_in *)&sin;
635 	    a = ntohl(sin4->sin_addr.s_addr);
636 	    p = ntohs(sin4->sin_port);
637 	    e = _ftp_cmd(cd, "PORT %d,%d,%d,%d,%d,%d",
638 			 (a >> 24) & 0xff, (a >> 16) & 0xff,
639 			 (a >> 8) & 0xff, a & 0xff,
640 			 (p >> 8) & 0xff, p & 0xff);
641 	    break;
642 	case AF_INET6:
643 #define UC(b)	(((int)b)&0xff)
644 	    e = -1;
645 	    sin6 = (struct sockaddr_in6 *)&sin;
646 	    if (getnameinfo((struct sockaddr *)&sin, sin.ss_len,
647 			    hname, sizeof(hname),
648 			    NULL, 0, NI_NUMERICHOST) == 0) {
649 		e = _ftp_cmd(cd, "EPRT |%d|%s|%d|", 2, hname,
650 			     htons(sin6->sin6_port));
651 		if (e == -1)
652 		    goto ouch;
653 	    }
654 	    if (e != FTP_OK) {
655 		ap = (char *)&sin6->sin6_addr;
656 		e = _ftp_cmd(cd,
657      "LPRT %d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d",
658 			     6, 16,
659 			     UC(ap[0]), UC(ap[1]), UC(ap[2]), UC(ap[3]),
660 			     UC(ap[4]), UC(ap[5]), UC(ap[6]), UC(ap[7]),
661 			     UC(ap[8]), UC(ap[9]), UC(ap[10]), UC(ap[11]),
662 			     UC(ap[12]), UC(ap[13]), UC(ap[14]), UC(ap[15]),
663 			     2,
664 			     (ntohs(sin6->sin6_port) >> 8) & 0xff,
665 			     ntohs(sin6->sin6_port)        & 0xff);
666 	    }
667 	    break;
668 	default:
669 	    e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
670 	    goto ouch;
671 	}
672 	if (e != FTP_OK)
673 	    goto ouch;
674 
675 	/* seek to required offset */
676 	if (offset)
677 	    if (_ftp_cmd(cd, "REST %lu", (u_long)offset) != FTP_FILE_OK)
678 		goto sysouch;
679 
680 	/* make the server initiate the transfer */
681 	if (verbose)
682 	    _fetch_info("initiating transfer");
683 	e = _ftp_cmd(cd, "%s %s", oper, _ftp_filename(file));
684 	if (e != FTP_OPEN_DATA_CONNECTION)
685 	    goto ouch;
686 
687 	/* accept the incoming connection and go to town */
688 	if ((d = accept(sd, NULL, NULL)) == -1)
689 	    goto sysouch;
690 	close(sd);
691 	sd = d;
692     }
693 
694     if ((df = _ftp_setup(cd, sd, mode)) == NULL)
695 	goto sysouch;
696     return df;
697 
698 sysouch:
699     _fetch_syserr();
700     if (sd >= 0)
701 	close(sd);
702     return NULL;
703 
704 ouch:
705     if (e != -1)
706 	_ftp_seterr(e);
707     if (sd >= 0)
708 	close(sd);
709     return NULL;
710 }
711 
712 /*
713  * Log on to FTP server
714  */
715 static int
716 _ftp_connect(struct url *url, struct url *purl, char *flags)
717 {
718     int cd, e, direct, verbose;
719 #ifdef INET6
720     int af = AF_UNSPEC;
721 #else
722     int af = AF_INET;
723 #endif
724     const char *logname;
725     char *user, *pwd;
726     char localhost[MAXHOSTNAMELEN];
727     char pbuf[MAXHOSTNAMELEN + MAXLOGNAME + 1];
728 
729     direct = CHECK_FLAG('d');
730     verbose = CHECK_FLAG('v');
731     if (CHECK_FLAG('4'))
732 	af = AF_INET;
733     else if (CHECK_FLAG('6'))
734 	af = AF_INET6;
735 
736     if (direct)
737 	purl = NULL;
738 
739     /* check for proxy */
740     if (purl) {
741 	/* XXX proxy authentication! */
742 	cd = _fetch_connect(purl->host, purl->port, af, verbose);
743     } else {
744 	/* no proxy, go straight to target */
745 	cd = _fetch_connect(url->host, url->port, af, verbose);
746 	purl = NULL;
747     }
748 
749     /* check connection */
750     if (cd == -1) {
751 	_fetch_syserr();
752 	return NULL;
753     }
754 
755     /* expect welcome message */
756     if ((e = _ftp_chkerr(cd)) != FTP_SERVICE_READY)
757 	goto fouch;
758 
759     /* XXX FTP_AUTH, and maybe .netrc */
760 
761     /* send user name and password */
762     user = url->user;
763     if (!user || !*user)
764 	user = getenv("FTP_LOGIN");
765     if (!user || !*user)
766 	user = FTP_ANONYMOUS_USER;
767     if (purl && url->port == _fetch_default_port(url->scheme))
768 	e = _ftp_cmd(cd, "USER %s@%s", user, url->host);
769     else if (purl)
770 	e = _ftp_cmd(cd, "USER %s@%s@%d", user, url->host, url->port);
771     else
772 	e = _ftp_cmd(cd, "USER %s", user);
773 
774     /* did the server request a password? */
775     if (e == FTP_NEED_PASSWORD) {
776 	pwd = url->pwd;
777 	if (!pwd || !*pwd)
778 	    pwd = getenv("FTP_PASSWORD");
779 	if (!pwd || !*pwd) {
780 	    if ((logname = getlogin()) == 0)
781 		logname = FTP_ANONYMOUS_USER;
782 	    gethostname(localhost, sizeof localhost);
783 	    snprintf(pbuf, sizeof pbuf, "%s@%s", logname, localhost);
784 	    pwd = pbuf;
785 	}
786 	e = _ftp_cmd(cd, "PASS %s", pwd);
787     }
788 
789     /* did the server request an account? */
790     if (e == FTP_NEED_ACCOUNT)
791 	goto fouch;
792 
793     /* we should be done by now */
794     if (e != FTP_LOGGED_IN)
795 	goto fouch;
796 
797     /* might as well select mode and type at once */
798 #ifdef FTP_FORCE_STREAM_MODE
799     if ((e = _ftp_cmd(cd, "MODE S")) != FTP_OK) /* default is S */
800 	goto fouch;
801 #endif
802     if ((e = _ftp_cmd(cd, "TYPE I")) != FTP_OK) /* default is A */
803 	goto fouch;
804 
805     /* done */
806     return cd;
807 
808 fouch:
809     if (e != -1)
810 	_ftp_seterr(e);
811     close(cd);
812     return NULL;
813 }
814 
815 /*
816  * Disconnect from server
817  */
818 static void
819 _ftp_disconnect(int cd)
820 {
821     (void)_ftp_cmd(cd, "QUIT");
822     close(cd);
823 }
824 
825 /*
826  * Check if we're already connected
827  */
828 static int
829 _ftp_isconnected(struct url *url)
830 {
831     return (cached_socket
832 	    && (strcmp(url->host, cached_host.host) == 0)
833 	    && (strcmp(url->user, cached_host.user) == 0)
834 	    && (strcmp(url->pwd, cached_host.pwd) == 0)
835 	    && (url->port == cached_host.port));
836 }
837 
838 /*
839  * Check the cache, reconnect if no luck
840  */
841 static int
842 _ftp_cached_connect(struct url *url, struct url *purl, char *flags)
843 {
844     int e, cd;
845 
846     cd = -1;
847 
848     /* set default port */
849     if (!url->port)
850 	url->port = _fetch_default_port(url->scheme);
851 
852     /* try to use previously cached connection */
853     if (_ftp_isconnected(url)) {
854 	e = _ftp_cmd(cached_socket, "NOOP");
855 	if (e == FTP_OK || e == FTP_SYNTAX_ERROR)
856 	    return cached_socket;
857     }
858 
859     /* connect to server */
860     if ((cd = _ftp_connect(url, purl, flags)) == -1)
861 	return -1;
862     if (cached_socket)
863 	_ftp_disconnect(cached_socket);
864     cached_socket = cd;
865     memcpy(&cached_host, url, sizeof *url);
866     return cd;
867 }
868 
869 /*
870  * Check the proxy settings
871  */
872 static struct url *
873 _ftp_get_proxy(void)
874 {
875     struct url *purl;
876     char *p;
877 
878     if (((p = getenv("FTP_PROXY")) || (p = getenv("HTTP_PROXY"))) &&
879 	*p && (purl = fetchParseURL(p)) != NULL) {
880 	if (!*purl->scheme) {
881 	    if (getenv("FTP_PROXY"))
882 		strcpy(purl->scheme, SCHEME_FTP);
883 	    else
884 		strcpy(purl->scheme, SCHEME_HTTP);
885 	}
886 	if (!purl->port)
887 	    purl->port = _fetch_default_proxy_port(purl->scheme);
888 	if (strcasecmp(purl->scheme, SCHEME_FTP) == 0 ||
889 	    strcasecmp(purl->scheme, SCHEME_HTTP) == 0)
890 	    return purl;
891 	fetchFreeURL(purl);
892     }
893     return NULL;
894 }
895 
896 /*
897  * Get and stat file
898  */
899 FILE *
900 fetchXGetFTP(struct url *url, struct url_stat *us, char *flags)
901 {
902     struct url *purl;
903     int cd;
904 
905     /* get the proxy URL, and check if we should use HTTP instead */
906     if (!CHECK_FLAG('d') && (purl = _ftp_get_proxy()) != NULL) {
907 	if (strcasecmp(purl->scheme, SCHEME_HTTP) == 0)
908 	    return _http_request(url, "GET", us, purl, flags);
909     } else {
910 	purl = NULL;
911     }
912 
913     /* connect to server */
914     cd = _ftp_cached_connect(url, purl, flags);
915     if (purl)
916 	fetchFreeURL(purl);
917     if (cd == NULL)
918 	return NULL;
919 
920     /* change directory */
921     if (_ftp_cwd(cd, url->doc) == -1)
922 	return NULL;
923 
924     /* stat file */
925     if (us && _ftp_stat(cd, url->doc, us) == -1
926 	&& fetchLastErrCode != FETCH_PROTO
927 	&& fetchLastErrCode != FETCH_UNAVAIL)
928 	return NULL;
929 
930     /* initiate the transfer */
931     return _ftp_transfer(cd, "RETR", url->doc, O_RDONLY, url->offset, flags);
932 }
933 
934 /*
935  * Get file
936  */
937 FILE *
938 fetchGetFTP(struct url *url, char *flags)
939 {
940     return fetchXGetFTP(url, NULL, flags);
941 }
942 
943 /*
944  * Put file
945  */
946 FILE *
947 fetchPutFTP(struct url *url, char *flags)
948 {
949     struct url *purl;
950     int cd;
951 
952     /* get the proxy URL, and check if we should use HTTP instead */
953     if (!CHECK_FLAG('d') && (purl = _ftp_get_proxy()) != NULL) {
954 	if (strcasecmp(purl->scheme, SCHEME_HTTP) == 0)
955 	    /* XXX HTTP PUT is not implemented, so try without the proxy */
956 	    purl = NULL;
957     } else {
958 	purl = NULL;
959     }
960 
961     /* connect to server */
962     cd = _ftp_cached_connect(url, purl, flags);
963     if (purl)
964 	fetchFreeURL(purl);
965     if (cd == NULL)
966 	return NULL;
967 
968     /* change directory */
969     if (_ftp_cwd(cd, url->doc) == -1)
970 	return NULL;
971 
972     /* initiate the transfer */
973     return _ftp_transfer(cd, CHECK_FLAG('a') ? "APPE" : "STOR",
974 			 url->doc, O_WRONLY, url->offset, flags);
975 }
976 
977 /*
978  * Get file stats
979  */
980 int
981 fetchStatFTP(struct url *url, struct url_stat *us, char *flags)
982 {
983     struct url *purl;
984     int cd;
985 
986     /* get the proxy URL, and check if we should use HTTP instead */
987     if (!CHECK_FLAG('d') && (purl = _ftp_get_proxy()) != NULL) {
988 	if (strcasecmp(purl->scheme, SCHEME_HTTP) == 0) {
989 	    FILE *f;
990 
991 	    if ((f = _http_request(url, "HEAD", us, purl, flags)) == NULL)
992 		return -1;
993 	    fclose(f);
994 	    return 0;
995 	}
996     } else {
997 	purl = NULL;
998     }
999 
1000     /* connect to server */
1001     cd = _ftp_cached_connect(url, purl, flags);
1002     if (purl)
1003 	fetchFreeURL(purl);
1004     if (cd == NULL)
1005 	return NULL;
1006 
1007     /* change directory */
1008     if (_ftp_cwd(cd, url->doc) == -1)
1009 	return -1;
1010 
1011     /* stat file */
1012     return _ftp_stat(cd, url->doc, us);
1013 }
1014 
1015 /*
1016  * List a directory
1017  */
1018 extern void warnx(char *, ...);
1019 struct url_ent *
1020 fetchListFTP(struct url *url, char *flags)
1021 {
1022     warnx("fetchListFTP(): not implemented");
1023     return NULL;
1024 }
1025