1/*-
2 * SPDX-License-Identifier: (BSD-3-Clause AND Beerware)
3 *
4 * Copyright (c) 1998-2011 Dag-Erling Sm��rgrav
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer
12 *    in this position and unchanged.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote products
17 *    derived from this software without specific prior written permission
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <sys/cdefs.h>
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 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
102static struct url cached_host;
103static conn_t	*cached_connection;
104
105#define isftpreply(foo)				\
106	(isdigit((unsigned char)foo[0]) &&	\
107	    isdigit((unsigned char)foo[1]) &&	\
108	    isdigit((unsigned char)foo[2]) &&	\
109	    (foo[3] == ' ' || foo[3] == '\0'))
110#define isftpinfo(foo) \
111	(isdigit((unsigned char)foo[0]) &&	\
112	    isdigit((unsigned char)foo[1]) &&	\
113	    isdigit((unsigned char)foo[2]) &&	\
114	    foo[3] == '-')
115
116/*
117 * Translate IPv4 mapped IPv6 address to IPv4 address
118 */
119static void
120unmappedaddr(struct sockaddr_in6 *sin6)
121{
122	struct sockaddr_in *sin4;
123	u_int32_t addr;
124	int port;
125
126	if (sin6->sin6_family != AF_INET6 ||
127	    !IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
128		return;
129	sin4 = (struct sockaddr_in *)sin6;
130	addr = *(u_int32_t *)(uintptr_t)&sin6->sin6_addr.s6_addr[12];
131	port = sin6->sin6_port;
132	memset(sin4, 0, sizeof(struct sockaddr_in));
133	sin4->sin_addr.s_addr = addr;
134	sin4->sin_port = port;
135	sin4->sin_family = AF_INET;
136	sin4->sin_len = sizeof(struct sockaddr_in);
137}
138
139/*
140 * Get server response
141 */
142static int
143ftp_chkerr(conn_t *conn)
144{
145	if (fetch_getln(conn) == -1) {
146		fetch_syserr();
147		return (-1);
148	}
149	if (isftpinfo(conn->buf)) {
150		while (conn->buflen && !isftpreply(conn->buf)) {
151			if (fetch_getln(conn) == -1) {
152				fetch_syserr();
153				return (-1);
154			}
155		}
156	}
157
158	while (conn->buflen &&
159	    isspace((unsigned char)conn->buf[conn->buflen - 1]))
160		conn->buflen--;
161	conn->buf[conn->buflen] = '\0';
162
163	if (!isftpreply(conn->buf)) {
164		ftp_seterr(FTP_PROTOCOL_ERROR);
165		return (-1);
166	}
167
168	conn->err = (conn->buf[0] - '0') * 100
169	    + (conn->buf[1] - '0') * 10
170	    + (conn->buf[2] - '0');
171
172	return (conn->err);
173}
174
175/*
176 * Send a command and check reply
177 */
178static int
179ftp_cmd(conn_t *conn, const char *fmt, ...)
180{
181	va_list ap;
182	size_t len;
183	char *msg;
184	int r;
185
186	va_start(ap, fmt);
187	len = vasprintf(&msg, fmt, ap);
188	va_end(ap);
189
190	if (msg == NULL) {
191		errno = ENOMEM;
192		fetch_syserr();
193		return (-1);
194	}
195
196	r = fetch_putln(conn, msg, len);
197	free(msg);
198
199	if (r == -1) {
200		fetch_syserr();
201		return (-1);
202	}
203
204	return (ftp_chkerr(conn));
205}
206
207/*
208 * Return a pointer to the filename part of a path
209 */
210static const char *
211ftp_filename(const char *file, int *len, int *type)
212{
213	const char *s;
214
215	if ((s = strrchr(file, '/')) == NULL)
216		s = file;
217	else
218		s = s + 1;
219	*len = strlen(s);
220	if (*len > 7 && strncmp(s + *len - 7, ";type=", 6) == 0) {
221		*type = s[*len - 1];
222		*len -= 7;
223	} else {
224		*type = '\0';
225	}
226	return (s);
227}
228
229/*
230 * Get current working directory from the reply to a CWD, PWD or CDUP
231 * command.
232 */
233static int
234ftp_pwd(conn_t *conn, char *pwd, size_t pwdlen)
235{
236	char *src, *dst, *end;
237	int q;
238
239	if (conn->err != FTP_WORKING_DIRECTORY &&
240	    conn->err != FTP_FILE_ACTION_OK)
241		return (FTP_PROTOCOL_ERROR);
242	end = conn->buf + conn->buflen;
243	src = conn->buf + 4;
244	if (src >= end || *src++ != '"')
245		return (FTP_PROTOCOL_ERROR);
246	for (q = 0, dst = pwd; src < end && pwdlen--; ++src) {
247		if (!q && *src == '"')
248			q = 1;
249		else if (q && *src != '"')
250			break;
251		else if (q)
252			*dst++ = '"', q = 0;
253		else
254			*dst++ = *src;
255	}
256	if (!pwdlen)
257		return (FTP_PROTOCOL_ERROR);
258	*dst = '\0';
259#if 0
260	DEBUGF("pwd: [%s]\n", pwd);
261#endif
262	return (FTP_OK);
263}
264
265/*
266 * Change working directory to the directory that contains the specified
267 * file.
268 */
269static int
270ftp_cwd(conn_t *conn, const char *file)
271{
272	const char *beg, *end;
273	char pwd[PATH_MAX];
274	int e, i, len;
275
276	/* If no slashes in name, no need to change dirs. */
277	if ((end = strrchr(file, '/')) == NULL)
278		return (0);
279	if ((e = ftp_cmd(conn, "PWD")) != FTP_WORKING_DIRECTORY ||
280	    (e = ftp_pwd(conn, pwd, sizeof(pwd))) != FTP_OK) {
281		ftp_seterr(e);
282		return (-1);
283	}
284	for (;;) {
285		len = strlen(pwd);
286
287		/* Look for a common prefix between PWD and dir to fetch. */
288		for (i = 0; i <= len && i <= end - file; ++i)
289			if (pwd[i] != file[i])
290				break;
291#if 0
292		DEBUGF("have: [%.*s|%s]\n", i, pwd, pwd + i);
293		DEBUGF("want: [%.*s|%s]\n", i, file, file + i);
294#endif
295		/* Keep going up a dir until we have a matching prefix. */
296		if (pwd[i] == '\0' && (file[i - 1] == '/' || file[i] == '/'))
297			break;
298		if ((e = ftp_cmd(conn, "CDUP")) != FTP_FILE_ACTION_OK ||
299		    (e = ftp_cmd(conn, "PWD")) != FTP_WORKING_DIRECTORY ||
300		    (e = ftp_pwd(conn, pwd, sizeof(pwd))) != FTP_OK) {
301			ftp_seterr(e);
302			return (-1);
303		}
304	}
305
306#ifdef FTP_COMBINE_CWDS
307	/* Skip leading slashes, even "////". */
308	for (beg = file + i; beg < end && *beg == '/'; ++beg, ++i)
309		/* nothing */ ;
310
311	/* If there is no trailing dir, we're already there. */
312	if (beg >= end)
313		return (0);
314
315	/* Change to the directory all in one chunk (e.g., foo/bar/baz). */
316	e = ftp_cmd(conn, "CWD %.*s", (int)(end - beg), beg);
317	if (e == FTP_FILE_ACTION_OK)
318		return (0);
319#endif /* FTP_COMBINE_CWDS */
320
321	/* That didn't work so go back to legacy behavior (multiple CWDs). */
322	for (beg = file + i; beg < end; beg = file + i + 1) {
323		while (*beg == '/')
324			++beg, ++i;
325		for (++i; file + i < end && file[i] != '/'; ++i)
326			/* nothing */ ;
327		e = ftp_cmd(conn, "CWD %.*s", file + i - beg, beg);
328		if (e != FTP_FILE_ACTION_OK) {
329			ftp_seterr(e);
330			return (-1);
331		}
332	}
333	return (0);
334}
335
336/*
337 * Set transfer mode and data type
338 */
339static int
340ftp_mode_type(conn_t *conn, int mode, int type)
341{
342	int e;
343
344	switch (mode) {
345	case 0:
346	case 's':
347		mode = 'S';
348	case 'S':
349		break;
350	default:
351		return (FTP_PROTOCOL_ERROR);
352	}
353	if ((e = ftp_cmd(conn, "MODE %c", mode)) != FTP_OK) {
354		if (mode == 'S') {
355			/*
356			 * Stream mode is supposed to be the default - so
357			 * much so that some servers not only do not
358			 * support any other mode, but do not support the
359			 * MODE command at all.
360			 *
361			 * If "MODE S" fails, it is unlikely that we
362			 * previously succeeded in setting a different
363			 * mode.  Therefore, we simply hope that the
364			 * server is already in the correct mode, and
365			 * silently ignore the failure.
366			 */
367		} else {
368			return (e);
369		}
370	}
371
372	switch (type) {
373	case 0:
374	case 'i':
375		type = 'I';
376	case 'I':
377		break;
378	case 'a':
379		type = 'A';
380	case 'A':
381		break;
382	case 'd':
383		type = 'D';
384	case 'D':
385		/* can't handle yet */
386	default:
387		return (FTP_PROTOCOL_ERROR);
388	}
389	if ((e = ftp_cmd(conn, "TYPE %c", type)) != FTP_OK)
390		return (e);
391
392	return (FTP_OK);
393}
394
395/*
396 * Request and parse file stats
397 */
398static int
399ftp_stat(conn_t *conn, const char *file, struct url_stat *us)
400{
401	char *ln;
402	const char *filename;
403	int filenamelen, type;
404	struct tm tm;
405	time_t t;
406	int e;
407
408	us->size = -1;
409	us->atime = us->mtime = 0;
410
411	filename = ftp_filename(file, &filenamelen, &type);
412
413	if ((e = ftp_mode_type(conn, 0, type)) != FTP_OK) {
414		ftp_seterr(e);
415		return (-1);
416	}
417
418	e = ftp_cmd(conn, "SIZE %.*s", filenamelen, filename);
419	if (e != FTP_FILE_STATUS) {
420		ftp_seterr(e);
421		return (-1);
422	}
423	for (ln = conn->buf + 4; *ln && isspace((unsigned char)*ln); ln++)
424		/* nothing */ ;
425	for (us->size = 0; *ln && isdigit((unsigned char)*ln); ln++)
426		us->size = us->size * 10 + *ln - '0';
427	if (*ln && !isspace((unsigned char)*ln)) {
428		ftp_seterr(FTP_PROTOCOL_ERROR);
429		us->size = -1;
430		return (-1);
431	}
432	if (us->size == 0)
433		us->size = -1;
434	DEBUGF("size: [%lld]\n", (long long)us->size);
435
436	e = ftp_cmd(conn, "MDTM %.*s", filenamelen, filename);
437	if (e != FTP_FILE_STATUS) {
438		ftp_seterr(e);
439		return (-1);
440	}
441	for (ln = conn->buf + 4; *ln && isspace((unsigned char)*ln); ln++)
442		/* nothing */ ;
443	switch (strspn(ln, "0123456789")) {
444	case 14:
445		break;
446	case 15:
447		ln++;
448		ln[0] = '2';
449		ln[1] = '0';
450		break;
451	default:
452		ftp_seterr(FTP_PROTOCOL_ERROR);
453		return (-1);
454	}
455	if (sscanf(ln, "%04d%02d%02d%02d%02d%02d",
456	    &tm.tm_year, &tm.tm_mon, &tm.tm_mday,
457	    &tm.tm_hour, &tm.tm_min, &tm.tm_sec) != 6) {
458		ftp_seterr(FTP_PROTOCOL_ERROR);
459		return (-1);
460	}
461	tm.tm_mon--;
462	tm.tm_year -= 1900;
463	tm.tm_isdst = -1;
464	t = timegm(&tm);
465	if (t == (time_t)-1)
466		t = time(NULL);
467	us->mtime = t;
468	us->atime = t;
469	DEBUGF("last modified: [%04d-%02d-%02d %02d:%02d:%02d]\n",
470	    tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
471	    tm.tm_hour, tm.tm_min, tm.tm_sec);
472	return (0);
473}
474
475/*
476 * I/O functions for FTP
477 */
478struct ftpio {
479	conn_t	*cconn;		/* Control connection */
480	conn_t	*dconn;		/* Data connection */
481	int	 dir;		/* Direction */
482	int	 eof;		/* EOF reached */
483	int	 err;		/* Error code */
484};
485
486static int	 ftp_readfn(void *, char *, int);
487static int	 ftp_writefn(void *, const char *, int);
488static fpos_t	 ftp_seekfn(void *, fpos_t, int);
489static int	 ftp_closefn(void *);
490
491static int
492ftp_readfn(void *v, char *buf, int len)
493{
494	struct ftpio *io;
495	int r;
496
497	io = (struct ftpio *)v;
498	if (io == NULL) {
499		errno = EBADF;
500		return (-1);
501	}
502	if (io->cconn == NULL || io->dconn == NULL || io->dir == O_WRONLY) {
503		errno = EBADF;
504		return (-1);
505	}
506	if (io->err) {
507		errno = io->err;
508		return (-1);
509	}
510	if (io->eof)
511		return (0);
512	r = fetch_read(io->dconn, buf, len);
513	if (r > 0)
514		return (r);
515	if (r == 0) {
516		io->eof = 1;
517		return (0);
518	}
519	if (errno != EINTR)
520		io->err = errno;
521	return (-1);
522}
523
524static int
525ftp_writefn(void *v, const char *buf, int len)
526{
527	struct ftpio *io;
528	int w;
529
530	io = (struct ftpio *)v;
531	if (io == NULL) {
532		errno = EBADF;
533		return (-1);
534	}
535	if (io->cconn == NULL || io->dconn == NULL || io->dir == O_RDONLY) {
536		errno = EBADF;
537		return (-1);
538	}
539	if (io->err) {
540		errno = io->err;
541		return (-1);
542	}
543	w = fetch_write(io->dconn, buf, len);
544	if (w >= 0)
545		return (w);
546	if (errno != EINTR)
547		io->err = errno;
548	return (-1);
549}
550
551static fpos_t
552ftp_seekfn(void *v, fpos_t pos __unused, int whence __unused)
553{
554	struct ftpio *io;
555
556	io = (struct ftpio *)v;
557	if (io == NULL) {
558		errno = EBADF;
559		return (-1);
560	}
561	errno = ESPIPE;
562	return (-1);
563}
564
565static int
566ftp_closefn(void *v)
567{
568	struct ftpio *io;
569	int r;
570
571	io = (struct ftpio *)v;
572	if (io == NULL) {
573		errno = EBADF;
574		return (-1);
575	}
576	if (io->dir == -1)
577		return (0);
578	if (io->cconn == NULL || io->dconn == NULL) {
579		errno = EBADF;
580		return (-1);
581	}
582	fetch_close(io->dconn);
583	io->dir = -1;
584	io->dconn = NULL;
585	DEBUGF("Waiting for final status\n");
586	r = ftp_chkerr(io->cconn);
587	if (io->cconn == cached_connection && io->cconn->ref == 1)
588		cached_connection = NULL;
589	fetch_close(io->cconn);
590	free(io);
591	return (r == FTP_TRANSFER_COMPLETE) ? 0 : -1;
592}
593
594static FILE *
595ftp_setup(conn_t *cconn, conn_t *dconn, int mode)
596{
597	struct ftpio *io;
598	FILE *f;
599
600	if (cconn == NULL || dconn == NULL)
601		return (NULL);
602	if ((io = malloc(sizeof(*io))) == NULL)
603		return (NULL);
604	io->cconn = cconn;
605	io->dconn = dconn;
606	io->dir = mode;
607	io->eof = io->err = 0;
608	f = funopen(io, ftp_readfn, ftp_writefn, ftp_seekfn, ftp_closefn);
609	if (f == NULL)
610		free(io);
611	return (f);
612}
613
614/*
615 * Transfer file
616 */
617static FILE *
618ftp_transfer(conn_t *conn, const char *oper, const char *file,
619    int mode, off_t offset, const char *flags)
620{
621	struct sockaddr_storage sa;
622	struct sockaddr_in6 *sin6;
623	struct sockaddr_in *sin4;
624	const char *bindaddr;
625	const char *filename;
626	int filenamelen, type;
627	int low, pasv, verbose;
628	int e, sd = -1;
629	socklen_t l;
630	char *s;
631	FILE *df;
632
633	/* check flags */
634	low = CHECK_FLAG('l');
635	pasv = CHECK_FLAG('p') || !CHECK_FLAG('P');
636	verbose = CHECK_FLAG('v');
637
638	/* passive mode */
639	if ((s = getenv("FTP_PASSIVE_MODE")) != NULL)
640		pasv = (strncasecmp(s, "no", 2) != 0);
641
642	/* isolate filename */
643	filename = ftp_filename(file, &filenamelen, &type);
644
645	/* set transfer mode and data type */
646	if ((e = ftp_mode_type(conn, 0, type)) != FTP_OK)
647		goto ouch;
648
649	/* find our own address, bind, and listen */
650	l = sizeof(sa);
651	if (getsockname(conn->sd, (struct sockaddr *)&sa, &l) == -1)
652		goto sysouch;
653	if (sa.ss_family == AF_INET6)
654		unmappedaddr((struct sockaddr_in6 *)&sa);
655
656	/* open data socket */
657	if ((sd = socket(sa.ss_family, SOCK_STREAM, IPPROTO_TCP)) == -1) {
658		fetch_syserr();
659		return (NULL);
660	}
661
662	if (pasv) {
663		u_char addr[64];
664		char *ln, *p;
665		unsigned int i;
666		int port;
667
668		/* send PASV command */
669		if (verbose)
670			fetch_info("setting passive mode");
671		switch (sa.ss_family) {
672		case AF_INET:
673			if ((e = ftp_cmd(conn, "PASV")) != FTP_PASSIVE_MODE)
674				goto ouch;
675			break;
676		case AF_INET6:
677			if ((e = ftp_cmd(conn, "EPSV")) != FTP_EPASSIVE_MODE) {
678				if (e == -1)
679					goto ouch;
680				if ((e = ftp_cmd(conn, "LPSV")) !=
681				    FTP_LPASSIVE_MODE)
682					goto ouch;
683			}
684			break;
685		default:
686			e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
687			goto ouch;
688		}
689
690		/*
691		 * Find address and port number. The reply to the PASV command
692		 * is IMHO the one and only weak point in the FTP protocol.
693		 */
694		ln = conn->buf;
695		switch (e) {
696		case FTP_PASSIVE_MODE:
697		case FTP_LPASSIVE_MODE:
698			for (p = ln + 3; *p && !isdigit((unsigned char)*p); p++)
699				/* nothing */ ;
700			if (!*p) {
701				e = FTP_PROTOCOL_ERROR;
702				goto ouch;
703			}
704			l = (e == FTP_PASSIVE_MODE ? 6 : 21);
705			for (i = 0; *p && i < l; i++, p++) {
706				addr[i] = strtol(p, &p, 10);
707				if (*p == '\0' && i < l - 1)
708					break;
709			}
710			if (i < l) {
711				e = FTP_PROTOCOL_ERROR;
712				goto ouch;
713			}
714			break;
715		case FTP_EPASSIVE_MODE:
716			for (p = ln + 3; *p && *p != '('; p++)
717				/* nothing */ ;
718			if (!*p) {
719				e = FTP_PROTOCOL_ERROR;
720				goto ouch;
721			}
722			++p;
723			if (sscanf(p, "%c%c%c%d%c", &addr[0], &addr[1], &addr[2],
724				&port, &addr[3]) != 5 ||
725			    addr[0] != addr[1] ||
726			    addr[0] != addr[2] || addr[0] != addr[3]) {
727				e = FTP_PROTOCOL_ERROR;
728				goto ouch;
729			}
730			break;
731		}
732
733		/* seek to required offset */
734		if (offset)
735			if (ftp_cmd(conn, "REST %lu", (u_long)offset) != FTP_FILE_OK)
736				goto sysouch;
737
738		/* construct sockaddr for data socket */
739		l = sizeof(sa);
740		if (getpeername(conn->sd, (struct sockaddr *)&sa, &l) == -1)
741			goto sysouch;
742		if (sa.ss_family == AF_INET6)
743			unmappedaddr((struct sockaddr_in6 *)&sa);
744		switch (sa.ss_family) {
745		case AF_INET6:
746			sin6 = (struct sockaddr_in6 *)&sa;
747			if (e == FTP_EPASSIVE_MODE)
748				sin6->sin6_port = htons(port);
749			else {
750				memcpy(&sin6->sin6_addr, addr + 2, 16);
751				memcpy(&sin6->sin6_port, addr + 19, 2);
752			}
753			break;
754		case AF_INET:
755			sin4 = (struct sockaddr_in *)&sa;
756			if (e == FTP_EPASSIVE_MODE)
757				sin4->sin_port = htons(port);
758			else {
759				memcpy(&sin4->sin_addr, addr, 4);
760				memcpy(&sin4->sin_port, addr + 4, 2);
761			}
762			break;
763		default:
764			e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
765			break;
766		}
767
768		/* connect to data port */
769		if (verbose)
770			fetch_info("opening data connection");
771		bindaddr = getenv("FETCH_BIND_ADDRESS");
772		if (bindaddr != NULL && *bindaddr != '\0' &&
773		    (e = fetch_bind(sd, sa.ss_family, bindaddr)) != 0)
774			goto ouch;
775		if (connect(sd, (struct sockaddr *)&sa, sa.ss_len) == -1)
776			goto sysouch;
777
778		/* make the server initiate the transfer */
779		if (verbose)
780			fetch_info("initiating transfer");
781		e = ftp_cmd(conn, "%s %.*s", oper, filenamelen, filename);
782		if (e != FTP_CONNECTION_ALREADY_OPEN && e != FTP_OPEN_DATA_CONNECTION)
783			goto ouch;
784
785	} else {
786		u_int32_t a;
787		u_short p;
788		int arg, d;
789		char *ap;
790		char hname[INET6_ADDRSTRLEN];
791
792		switch (sa.ss_family) {
793		case AF_INET6:
794			((struct sockaddr_in6 *)&sa)->sin6_port = 0;
795#ifdef IPV6_PORTRANGE
796			arg = low ? IPV6_PORTRANGE_DEFAULT : IPV6_PORTRANGE_HIGH;
797			if (setsockopt(sd, IPPROTO_IPV6, IPV6_PORTRANGE,
798				(char *)&arg, sizeof(arg)) == -1)
799				goto sysouch;
800#endif
801			break;
802		case AF_INET:
803			((struct sockaddr_in *)&sa)->sin_port = 0;
804			arg = low ? IP_PORTRANGE_DEFAULT : IP_PORTRANGE_HIGH;
805			if (setsockopt(sd, IPPROTO_IP, IP_PORTRANGE,
806				(char *)&arg, sizeof(arg)) == -1)
807				goto sysouch;
808			break;
809		}
810		if (verbose)
811			fetch_info("binding data socket");
812		if (bind(sd, (struct sockaddr *)&sa, sa.ss_len) == -1)
813			goto sysouch;
814		if (listen(sd, 1) == -1)
815			goto sysouch;
816
817		/* find what port we're on and tell the server */
818		if (getsockname(sd, (struct sockaddr *)&sa, &l) == -1)
819			goto sysouch;
820		switch (sa.ss_family) {
821		case AF_INET:
822			sin4 = (struct sockaddr_in *)&sa;
823			a = ntohl(sin4->sin_addr.s_addr);
824			p = ntohs(sin4->sin_port);
825			e = ftp_cmd(conn, "PORT %d,%d,%d,%d,%d,%d",
826			    (a >> 24) & 0xff, (a >> 16) & 0xff,
827			    (a >> 8) & 0xff, a & 0xff,
828			    (p >> 8) & 0xff, p & 0xff);
829			break;
830		case AF_INET6:
831#define UC(b)	(((int)b)&0xff)
832			e = -1;
833			sin6 = (struct sockaddr_in6 *)&sa;
834			sin6->sin6_scope_id = 0;
835			if (getnameinfo((struct sockaddr *)&sa, sa.ss_len,
836				hname, sizeof(hname),
837				NULL, 0, NI_NUMERICHOST) == 0) {
838				e = ftp_cmd(conn, "EPRT |%d|%s|%d|", 2, hname,
839				    htons(sin6->sin6_port));
840				if (e == -1)
841					goto ouch;
842			}
843			if (e != FTP_OK) {
844				ap = (char *)&sin6->sin6_addr;
845				e = ftp_cmd(conn,
846				    "LPRT %d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d",
847				    6, 16,
848				    UC(ap[0]), UC(ap[1]), UC(ap[2]), UC(ap[3]),
849				    UC(ap[4]), UC(ap[5]), UC(ap[6]), UC(ap[7]),
850				    UC(ap[8]), UC(ap[9]), UC(ap[10]), UC(ap[11]),
851				    UC(ap[12]), UC(ap[13]), UC(ap[14]), UC(ap[15]),
852				    2,
853				    (ntohs(sin6->sin6_port) >> 8) & 0xff,
854				    ntohs(sin6->sin6_port)        & 0xff);
855			}
856			break;
857		default:
858			e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
859			goto ouch;
860		}
861		if (e != FTP_OK)
862			goto ouch;
863
864		/* seek to required offset */
865		if (offset)
866			if (ftp_cmd(conn, "REST %ju", (uintmax_t)offset) != FTP_FILE_OK)
867				goto sysouch;
868
869		/* make the server initiate the transfer */
870		if (verbose)
871			fetch_info("initiating transfer");
872		e = ftp_cmd(conn, "%s %.*s", oper, filenamelen, filename);
873		if (e != FTP_CONNECTION_ALREADY_OPEN && e != FTP_OPEN_DATA_CONNECTION)
874			goto ouch;
875
876		/* accept the incoming connection and go to town */
877		if ((d = accept(sd, NULL, NULL)) == -1)
878			goto sysouch;
879		close(sd);
880		sd = d;
881	}
882
883	if ((df = ftp_setup(conn, fetch_reopen(sd), mode)) == NULL)
884		goto sysouch;
885	return (df);
886
887sysouch:
888	fetch_syserr();
889	if (sd >= 0)
890		close(sd);
891	return (NULL);
892
893ouch:
894	if (e != -1)
895		ftp_seterr(e);
896	if (sd >= 0)
897		close(sd);
898	return (NULL);
899}
900
901/*
902 * Authenticate
903 */
904static int
905ftp_authenticate(conn_t *conn, struct url *url, struct url *purl)
906{
907	const char *user, *pwd, *logname;
908	char pbuf[MAXHOSTNAMELEN + MAXLOGNAME + 1];
909	int e, len;
910
911	/* XXX FTP_AUTH, and maybe .netrc */
912
913	/* send user name and password */
914	if (url->user[0] == '\0')
915		fetch_netrc_auth(url);
916	user = url->user;
917	if (*user == '\0')
918		if ((user = getenv("FTP_LOGIN")) != NULL)
919			DEBUGF("FTP_LOGIN=%s\n", user);
920	if (user == NULL || *user == '\0')
921		user = FTP_ANONYMOUS_USER;
922	if (purl && url->port == fetch_default_port(url->scheme))
923		e = ftp_cmd(conn, "USER %s@%s", user, url->host);
924	else if (purl)
925		e = ftp_cmd(conn, "USER %s@%s@%d", user, url->host, url->port);
926	else
927		e = ftp_cmd(conn, "USER %s", user);
928
929	/* did the server request a password? */
930	if (e == FTP_NEED_PASSWORD) {
931		pwd = url->pwd;
932		if (*pwd == '\0')
933			if ((pwd = getenv("FTP_PASSWORD")) != NULL)
934				DEBUGF("FTP_PASSWORD=%s\n", pwd);
935		if (pwd == NULL || *pwd == '\0') {
936			if ((logname = getlogin()) == NULL)
937				logname = FTP_ANONYMOUS_USER;
938			if ((len = snprintf(pbuf, MAXLOGNAME + 1, "%s@", logname)) < 0)
939				len = 0;
940			else if (len > MAXLOGNAME)
941				len = MAXLOGNAME;
942			gethostname(pbuf + len, sizeof(pbuf) - len);
943			pwd = pbuf;
944		}
945		e = ftp_cmd(conn, "PASS %s", pwd);
946	}
947
948	return (e);
949}
950
951/*
952 * Log on to FTP server
953 */
954static conn_t *
955ftp_connect(struct url *url, struct url *purl, const char *flags)
956{
957	conn_t *conn;
958	int e, direct, verbose;
959#ifdef INET6
960	int af = AF_UNSPEC;
961#else
962	int af = AF_INET;
963#endif
964
965	direct = CHECK_FLAG('d');
966	verbose = CHECK_FLAG('v');
967	if (CHECK_FLAG('4'))
968		af = AF_INET;
969	else if (CHECK_FLAG('6'))
970		af = AF_INET6;
971
972	if (direct)
973		purl = NULL;
974
975	/* check for proxy */
976	if (purl) {
977		/* XXX proxy authentication! */
978		conn = fetch_connect(purl->host, purl->port, af, verbose);
979	} else {
980		/* no proxy, go straight to target */
981		conn = fetch_connect(url->host, url->port, af, verbose);
982		purl = NULL;
983	}
984
985	/* check connection */
986	if (conn == NULL)
987		/* fetch_connect() has already set an error code */
988		return (NULL);
989
990	/* expect welcome message */
991	if ((e = ftp_chkerr(conn)) != FTP_SERVICE_READY)
992		goto fouch;
993
994	/* authenticate */
995	if ((e = ftp_authenticate(conn, url, purl)) != FTP_LOGGED_IN)
996		goto fouch;
997
998	/* TODO: Request extended features supported, if any (RFC 3659). */
999
1000	/* done */
1001	return (conn);
1002
1003fouch:
1004	if (e != -1)
1005		ftp_seterr(e);
1006	fetch_close(conn);
1007	return (NULL);
1008}
1009
1010/*
1011 * Disconnect from server
1012 */
1013static void
1014ftp_disconnect(conn_t *conn)
1015{
1016	(void)ftp_cmd(conn, "QUIT");
1017	if (conn == cached_connection && conn->ref == 1)
1018		cached_connection = NULL;
1019	fetch_close(conn);
1020}
1021
1022/*
1023 * Check if we're already connected
1024 */
1025static int
1026ftp_isconnected(struct url *url)
1027{
1028	return (cached_connection
1029	    && (strcmp(url->host, cached_host.host) == 0)
1030	    && (strcmp(url->user, cached_host.user) == 0)
1031	    && (strcmp(url->pwd, cached_host.pwd) == 0)
1032	    && (url->port == cached_host.port));
1033}
1034
1035/*
1036 * Check the cache, reconnect if no luck
1037 */
1038static conn_t *
1039ftp_cached_connect(struct url *url, struct url *purl, const char *flags)
1040{
1041	conn_t *conn;
1042	int e;
1043
1044	/* set default port */
1045	if (!url->port)
1046		url->port = fetch_default_port(url->scheme);
1047
1048	/* try to use previously cached connection */
1049	if (ftp_isconnected(url)) {
1050		e = ftp_cmd(cached_connection, "NOOP");
1051		if (e == FTP_OK || e == FTP_SYNTAX_ERROR)
1052			return (fetch_ref(cached_connection));
1053	}
1054
1055	/* connect to server */
1056	if ((conn = ftp_connect(url, purl, flags)) == NULL)
1057		return (NULL);
1058	if (cached_connection)
1059		ftp_disconnect(cached_connection);
1060	cached_connection = fetch_ref(conn);
1061	memcpy(&cached_host, url, sizeof(*url));
1062	return (conn);
1063}
1064
1065/*
1066 * Check the proxy settings
1067 */
1068static struct url *
1069ftp_get_proxy(struct url * url, const char *flags)
1070{
1071	struct url *purl;
1072	char *p;
1073
1074	if (flags != NULL && strchr(flags, 'd') != NULL)
1075		return (NULL);
1076	if (fetch_no_proxy_match(url->host))
1077		return (NULL);
1078	if (((p = getenv("FTP_PROXY")) || (p = getenv("ftp_proxy")) ||
1079		(p = getenv("HTTP_PROXY")) || (p = getenv("http_proxy"))) &&
1080	    *p && (purl = fetchParseURL(p)) != NULL) {
1081		if (!*purl->scheme) {
1082			if (getenv("FTP_PROXY") || getenv("ftp_proxy"))
1083				strcpy(purl->scheme, SCHEME_FTP);
1084			else
1085				strcpy(purl->scheme, SCHEME_HTTP);
1086		}
1087		if (!purl->port)
1088			purl->port = fetch_default_proxy_port(purl->scheme);
1089		if (strcmp(purl->scheme, SCHEME_FTP) == 0 ||
1090		    strcmp(purl->scheme, SCHEME_HTTP) == 0)
1091			return (purl);
1092		fetchFreeURL(purl);
1093	}
1094	return (NULL);
1095}
1096
1097/*
1098 * Process an FTP request
1099 */
1100FILE *
1101ftp_request(struct url *url, const char *op, struct url_stat *us,
1102    struct url *purl, const char *flags)
1103{
1104	conn_t *conn;
1105	int oflag;
1106
1107	/* check if we should use HTTP instead */
1108	if (purl && (strcmp(purl->scheme, SCHEME_HTTP) == 0 ||
1109	    strcmp(purl->scheme, SCHEME_HTTPS) == 0)) {
1110		if (strcmp(op, "STAT") == 0)
1111			return (http_request(url, "HEAD", us, purl, flags));
1112		else if (strcmp(op, "RETR") == 0)
1113			return (http_request(url, "GET", us, purl, flags));
1114		/*
1115		 * Our HTTP code doesn't support PUT requests yet, so try
1116		 * a direct connection.
1117		 */
1118	}
1119
1120	/* connect to server */
1121	conn = ftp_cached_connect(url, purl, flags);
1122	if (purl)
1123		fetchFreeURL(purl);
1124	if (conn == NULL)
1125		return (NULL);
1126
1127	/* change directory */
1128	if (ftp_cwd(conn, url->doc) == -1)
1129		goto errsock;
1130
1131	/* stat file */
1132	if (us && ftp_stat(conn, url->doc, us) == -1
1133	    && fetchLastErrCode != FETCH_PROTO
1134	    && fetchLastErrCode != FETCH_UNAVAIL)
1135		goto errsock;
1136
1137	/* just a stat */
1138	if (strcmp(op, "STAT") == 0) {
1139		--conn->ref;
1140		ftp_disconnect(conn);
1141		return (FILE *)1; /* bogus return value */
1142	}
1143	if (strcmp(op, "STOR") == 0 || strcmp(op, "APPE") == 0)
1144		oflag = O_WRONLY;
1145	else
1146		oflag = O_RDONLY;
1147
1148	/* initiate the transfer */
1149	return (ftp_transfer(conn, op, url->doc, oflag, url->offset, flags));
1150
1151errsock:
1152	ftp_disconnect(conn);
1153	return (NULL);
1154}
1155
1156/*
1157 * Get and stat file
1158 */
1159FILE *
1160fetchXGetFTP(struct url *url, struct url_stat *us, const char *flags)
1161{
1162	return (ftp_request(url, "RETR", us, ftp_get_proxy(url, flags), flags));
1163}
1164
1165/*
1166 * Get file
1167 */
1168FILE *
1169fetchGetFTP(struct url *url, const char *flags)
1170{
1171	return (fetchXGetFTP(url, NULL, flags));
1172}
1173
1174/*
1175 * Put file
1176 */
1177FILE *
1178fetchPutFTP(struct url *url, const char *flags)
1179{
1180	return (ftp_request(url, CHECK_FLAG('a') ? "APPE" : "STOR", NULL,
1181	    ftp_get_proxy(url, flags), flags));
1182}
1183
1184/*
1185 * Get file stats
1186 */
1187int
1188fetchStatFTP(struct url *url, struct url_stat *us, const char *flags)
1189{
1190	FILE *f;
1191
1192	f = ftp_request(url, "STAT", us, ftp_get_proxy(url, flags), flags);
1193	if (f == NULL)
1194		return (-1);
1195	/*
1196	 * When op is "STAT", ftp_request() will return either NULL or
1197	 * (FILE *)1, never a valid FILE *, so we mustn't fclose(f) before
1198	 * returning, as it would cause a segfault.
1199	 */
1200	return (0);
1201}
1202
1203/*
1204 * List a directory
1205 */
1206struct url_ent *
1207fetchListFTP(struct url *url __unused, const char *flags __unused)
1208{
1209	warnx("fetchListFTP(): not implemented");
1210	return (NULL);
1211}
1212