1 /* $NetBSD: ftp.c,v 1.8 2024/02/02 22:19:05 christos Exp $ */
2 /*-
3 * Copyright (c) 1998-2004 Dag-Erling Co�dan Sm�rgrav
4 * Copyright (c) 2008, 2009, 2010 Joerg Sonnenberger <joerg@NetBSD.org>
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 * $FreeBSD: ftp.c,v 1.101 2008/01/23 20:57:59 des Exp $
31 */
32
33 /*
34 * Portions of this code were taken from or based on ftpio.c:
35 *
36 * ----------------------------------------------------------------------------
37 * "THE BEER-WARE LICENSE" (Revision 42):
38 * <phk@FreeBSD.org> wrote this file. As long as you retain this notice you
39 * can do whatever you want with this stuff. If we meet some day, and you think
40 * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
41 * ----------------------------------------------------------------------------
42 *
43 * Major Changelog:
44 *
45 * Dag-Erling Co�dan Sm�rgrav
46 * 9 Jun 1998
47 *
48 * Incorporated into libfetch
49 *
50 * Jordan K. Hubbard
51 * 17 Jan 1996
52 *
53 * Turned inside out. Now returns xfers as new file ids, not as a special
54 * `state' of FTP_t
55 *
56 * $ftpioId: ftpio.c,v 1.30 1998/04/11 07:28:53 phk Exp $
57 *
58 */
59
60 #ifdef __linux__
61 /* Keep this down to Linux, it can create surprises else where. */
62 #define _GNU_SOURCE
63 #endif
64
65 #if HAVE_CONFIG_H
66 #include "config.h"
67 #endif
68 #ifndef NETBSD
69 #include <nbcompat.h>
70 #endif
71
72 #include <sys/types.h>
73 #include <sys/socket.h>
74
75 #include <netinet/in.h>
76 #include <arpa/inet.h>
77
78 #include <ctype.h>
79 #include <errno.h>
80 #include <fcntl.h>
81 #if defined(HAVE_INTTYPES_H) || defined(NETBSD)
82 #include <inttypes.h>
83 #endif
84 #include <stdarg.h>
85 #ifndef NETBSD
86 #include <nbcompat/netdb.h>
87 #include <nbcompat/stdio.h>
88 #else
89 #include <netdb.h>
90 #include <stdio.h>
91 #endif
92 #include <stdlib.h>
93 #include <string.h>
94 #include <time.h>
95 #include <unistd.h>
96
97 #include "fetch.h"
98 #include "common.h"
99 #include "ftperr.h"
100
101 #define FTP_ANONYMOUS_USER "anonymous"
102
103 #define FTP_CONNECTION_ALREADY_OPEN 125
104 #define FTP_OPEN_DATA_CONNECTION 150
105 #define FTP_OK 200
106 #define FTP_FILE_STATUS 213
107 #define FTP_SERVICE_READY 220
108 #define FTP_TRANSFER_COMPLETE 226
109 #define FTP_PASSIVE_MODE 227
110 #define FTP_LPASSIVE_MODE 228
111 #define FTP_EPASSIVE_MODE 229
112 #define FTP_LOGGED_IN 230
113 #define FTP_FILE_ACTION_OK 250
114 #define FTP_DIRECTORY_CREATED 257 /* multiple meanings */
115 #define FTP_FILE_CREATED 257 /* multiple meanings */
116 #define FTP_WORKING_DIRECTORY 257 /* multiple meanings */
117 #define FTP_NEED_PASSWORD 331
118 #define FTP_NEED_ACCOUNT 332
119 #define FTP_FILE_OK 350
120 #define FTP_SYNTAX_ERROR 500
121 #define FTP_PROTOCOL_ERROR 999
122
123 #define isftpreply(foo) \
124 (isdigit((unsigned char)foo[0]) && \
125 isdigit((unsigned char)foo[1]) && \
126 isdigit((unsigned char)foo[2]) && \
127 (foo[3] == ' ' || foo[3] == '\0'))
128 #define isftpinfo(foo) \
129 (isdigit((unsigned char)foo[0]) && \
130 isdigit((unsigned char)foo[1]) && \
131 isdigit((unsigned char)foo[2]) && \
132 foo[3] == '-')
133
134 /*
135 * Translate IPv4 mapped IPv6 address to IPv4 address
136 */
137 static void
unmappedaddr(struct sockaddr_in6 * sin6,socklen_t * len)138 unmappedaddr(struct sockaddr_in6 *sin6, socklen_t *len)
139 {
140 struct sockaddr_in *sin4;
141 uint32_t addr;
142 int port;
143
144 if (sin6->sin6_family != AF_INET6 ||
145 !IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
146 return;
147 sin4 = (struct sockaddr_in *)(void *)sin6;
148 #ifdef s6_addr32
149 addr = sin6->sin6_addr.s6_addr32[3];
150 #else
151 memcpy(&addr, &sin6->sin6_addr.s6_addr[12], sizeof(addr));
152 #endif
153 port = sin6->sin6_port;
154 memset(sin4, 0, sizeof(struct sockaddr_in));
155 sin4->sin_addr.s_addr = addr;
156 sin4->sin_port = port;
157 sin4->sin_family = AF_INET;
158 *len = sizeof(struct sockaddr_in);
159 #ifdef HAVE_SA_LEN
160 sin4->sin_len = sizeof(struct sockaddr_in);
161 #endif
162 }
163
164 /*
165 * Get server response
166 */
167 static int
ftp_chkerr(conn_t * conn)168 ftp_chkerr(conn_t *conn)
169 {
170 if (fetch_getln(conn) == -1) {
171 fetch_syserr();
172 return (-1);
173 }
174 if (isftpinfo(conn->buf)) {
175 while (conn->buflen && !isftpreply(conn->buf)) {
176 if (fetch_getln(conn) == -1) {
177 fetch_syserr();
178 return (-1);
179 }
180 }
181 }
182
183 while (conn->buflen &&
184 isspace((unsigned char)conn->buf[conn->buflen - 1]))
185 conn->buflen--;
186 conn->buf[conn->buflen] = '\0';
187
188 if (!isftpreply(conn->buf)) {
189 ftp_seterr(FTP_PROTOCOL_ERROR);
190 return (-1);
191 }
192
193 conn->err = (conn->buf[0] - '0') * 100
194 + (conn->buf[1] - '0') * 10
195 + (conn->buf[2] - '0');
196
197 return (conn->err);
198 }
199
200 /*
201 * Send a command and check reply
202 */
203 LIBFETCH_PRINTFLIKE(2, 3)
204 static int
ftp_cmd(conn_t * conn,const char * fmt,...)205 ftp_cmd(conn_t *conn, const char *fmt, ...)
206 {
207 va_list ap;
208 size_t len;
209 char *msg;
210 ssize_t r;
211
212 va_start(ap, fmt);
213 len = vasprintf(&msg, fmt, ap);
214 va_end(ap);
215
216 if (msg == NULL) {
217 errno = ENOMEM;
218 fetch_syserr();
219 return (-1);
220 }
221
222 r = fetch_write(conn, msg, len);
223 free(msg);
224
225 if (r == -1) {
226 fetch_syserr();
227 return (-1);
228 }
229
230 return (ftp_chkerr(conn));
231 }
232
233 /*
234 * Return a pointer to the filename part of a path
235 */
236 static const char *
ftp_filename(const char * file,size_t * len,int * type,int subdir)237 ftp_filename(const char *file, size_t *len, int *type, int subdir)
238 {
239 const char *s;
240
241 if ((s = strrchr(file, '/')) == NULL || subdir)
242 s = file;
243 else
244 s = s + 1;
245 *len = strlen(s);
246 if (*len > 7 && strncmp(s + *len - 7, ";type=", 6) == 0) {
247 *type = s[*len - 1];
248 *len -= 7;
249 } else {
250 *type = '\0';
251 }
252 return (s);
253 }
254
255 /*
256 * Get current working directory from the reply to a CWD, PWD or CDUP
257 * command.
258 */
259 static int
ftp_pwd(conn_t * conn,char ** pwd)260 ftp_pwd(conn_t *conn, char **pwd)
261 {
262 char *src, *dst, *end;
263 int q;
264 size_t len;
265
266 if (conn->err != FTP_WORKING_DIRECTORY &&
267 conn->err != FTP_FILE_ACTION_OK)
268 return (FTP_PROTOCOL_ERROR);
269 end = conn->buf + conn->buflen;
270 src = conn->buf + 4;
271 if (src >= end || *src++ != '"')
272 return (FTP_PROTOCOL_ERROR);
273 len = end - src + 1;
274 *pwd = malloc(len);
275 if (*pwd == NULL)
276 return (FTP_PROTOCOL_ERROR);
277 for (q = 0, dst = *pwd; src < end; ++src) {
278 if (!q && *src == '"')
279 q = 1;
280 else if (q && *src != '"')
281 break;
282 else if (q)
283 *dst++ = '"', q = 0;
284 else
285 *dst++ = *src;
286 }
287 *dst = '\0';
288 if (**pwd != '/') {
289 free(*pwd);
290 *pwd = NULL;
291 return (FTP_PROTOCOL_ERROR);
292 }
293 return (FTP_OK);
294 }
295
296 /*
297 * Change working directory to the directory that contains the specified
298 * file.
299 */
300 static int
ftp_cwd(conn_t * conn,const char * path,int subdir)301 ftp_cwd(conn_t *conn, const char *path, int subdir)
302 {
303 const char *beg, *end;
304 char *pwd, *dst;
305 int e;
306 size_t i, len;
307
308 if (*path != '/') {
309 ftp_seterr(501);
310 return (-1);
311 }
312 ++path;
313
314 /* Simple case: still in the home directory and no directory change. */
315 if (conn->ftp_home == NULL && strchr(path, '/') == NULL &&
316 (!subdir || *path == '\0'))
317 return 0;
318
319 if ((e = ftp_cmd(conn, "PWD\r\n")) != FTP_WORKING_DIRECTORY ||
320 (e = ftp_pwd(conn, &pwd)) != FTP_OK) {
321 ftp_seterr(e);
322 return (-1);
323 }
324 if (conn->ftp_home == NULL && (conn->ftp_home = strdup(pwd)) == NULL) {
325 fetch_syserr();
326 free(pwd);
327 return (-1);
328 }
329 if (*path == '/') {
330 while (path[1] == '/')
331 ++path;
332 dst = strdup(path);
333 } else if (strcmp(conn->ftp_home, "/") == 0) {
334 dst = strdup(path - 1);
335 } else {
336 if (asprintf(&dst, "%s/%s", conn->ftp_home, path) == -1)
337 dst = NULL;
338 }
339 if (dst == NULL) {
340 fetch_syserr();
341 free(pwd);
342 return (-1);
343 }
344
345 if (subdir)
346 end = dst + strlen(dst);
347 else
348 end = strrchr(dst, '/');
349
350 for (;;) {
351 len = strlen(pwd);
352
353 /* Look for a common prefix between PWD and dir to fetch. */
354 for (i = 0; i <= len && i <= (size_t)(end - dst); ++i)
355 if (pwd[i] != dst[i])
356 break;
357 /* Keep going up a dir until we have a matching prefix. */
358 if (strcmp(pwd, "/") == 0)
359 break;
360 if (pwd[i] == '\0' && (dst[i - 1] == '/' || dst[i] == '/'))
361 break;
362 free(pwd);
363 if ((e = ftp_cmd(conn, "CDUP\r\n")) != FTP_FILE_ACTION_OK ||
364 (e = ftp_cmd(conn, "PWD\r\n")) != FTP_WORKING_DIRECTORY ||
365 (e = ftp_pwd(conn, &pwd)) != FTP_OK) {
366 ftp_seterr(e);
367 free(dst);
368 return (-1);
369 }
370 }
371 free(pwd);
372
373 #ifdef FTP_COMBINE_CWDS
374 /* Skip leading slashes, even "////". */
375 for (beg = dst + i; beg < end && *beg == '/'; ++beg, ++i)
376 /* nothing */ ;
377
378 /* If there is no trailing dir, we're already there. */
379 if (beg >= end) {
380 free(dst);
381 return (0);
382 }
383
384 /* Change to the directory all in one chunk (e.g., foo/bar/baz). */
385 e = ftp_cmd(conn, "CWD %.*s\r\n", (int)(end - beg), beg);
386 if (e == FTP_FILE_ACTION_OK) {
387 free(dst);
388 return (0);
389 }
390 #endif /* FTP_COMBINE_CWDS */
391
392 /* That didn't work so go back to legacy behavior (multiple CWDs). */
393 for (beg = dst + i; beg < end; beg = dst + i + 1) {
394 while (*beg == '/')
395 ++beg, ++i;
396 for (++i; dst + i < end && dst[i] != '/'; ++i)
397 /* nothing */ ;
398 e = ftp_cmd(conn, "CWD %.*s\r\n", (int)(dst + i - beg), beg);
399 if (e != FTP_FILE_ACTION_OK) {
400 free(dst);
401 ftp_seterr(e);
402 return (-1);
403 }
404 }
405 free(dst);
406 return (0);
407 }
408
409 /*
410 * Set transfer mode and data type
411 */
412 static int
ftp_mode_type(conn_t * conn,int mode,int type)413 ftp_mode_type(conn_t *conn, int mode, int type)
414 {
415 int e;
416
417 switch (mode) {
418 case 0:
419 case 's':
420 mode = 'S';
421 /*FALLTHROUGH*/
422 case 'S':
423 break;
424 default:
425 return (FTP_PROTOCOL_ERROR);
426 }
427 if ((e = ftp_cmd(conn, "MODE %c\r\n", mode)) != FTP_OK) {
428 if (mode == 'S') {
429 /*
430 * Stream mode is supposed to be the default - so
431 * much so that some servers not only do not
432 * support any other mode, but do not support the
433 * MODE command at all.
434 *
435 * If "MODE S" fails, it is unlikely that we
436 * previously succeeded in setting a different
437 * mode. Therefore, we simply hope that the
438 * server is already in the correct mode, and
439 * silently ignore the failure.
440 */
441 } else {
442 return (e);
443 }
444 }
445
446 switch (type) {
447 case 0:
448 case 'i':
449 type = 'I';
450 /*FALLTHROUGH*/
451 case 'I':
452 break;
453 case 'a':
454 type = 'A';
455 /*FALLTHROUGH*/
456 case 'A':
457 break;
458 case 'd':
459 type = 'D';
460 /*FALLTHROUGH*/
461 case 'D':
462 /* can't handle yet */
463 default:
464 return (FTP_PROTOCOL_ERROR);
465 }
466 if ((e = ftp_cmd(conn, "TYPE %c\r\n", type)) != FTP_OK)
467 return (e);
468
469 return (FTP_OK);
470 }
471
472 /*
473 * Request and parse file stats
474 */
475 static int
ftp_stat(conn_t * conn,const char * file,struct url_stat * us)476 ftp_stat(conn_t *conn, const char *file, struct url_stat *us)
477 {
478 char *ln;
479 const char *filename;
480 size_t filenamelen;
481 int type;
482 struct tm tm;
483 time_t t;
484 int e;
485
486 us->size = -1;
487 us->atime = us->mtime = 0;
488
489 filename = ftp_filename(file, &filenamelen, &type, 0);
490
491 if ((e = ftp_mode_type(conn, 0, type)) != FTP_OK) {
492 ftp_seterr(e);
493 return (-1);
494 }
495
496 e = ftp_cmd(conn, "SIZE %.*s\r\n", (int)filenamelen, filename);
497 if (e != FTP_FILE_STATUS) {
498 ftp_seterr(e);
499 return (-1);
500 }
501 for (ln = conn->buf + 4; *ln && isspace((unsigned char)*ln); ln++)
502 /* nothing */ ;
503 for (us->size = 0; *ln && isdigit((unsigned char)*ln); ln++)
504 us->size = us->size * 10 + *ln - '0';
505 if (*ln && !isspace((unsigned char)*ln)) {
506 ftp_seterr(FTP_PROTOCOL_ERROR);
507 us->size = -1;
508 return (-1);
509 }
510 if (us->size == 0)
511 us->size = -1;
512
513 e = ftp_cmd(conn, "MDTM %.*s\r\n", (int)filenamelen, filename);
514 if (e != FTP_FILE_STATUS) {
515 ftp_seterr(e);
516 return (-1);
517 }
518 for (ln = conn->buf + 4; *ln && isspace((unsigned char)*ln); ln++)
519 /* nothing */ ;
520 switch (strspn(ln, "0123456789")) {
521 case 14:
522 break;
523 case 15:
524 ln++;
525 ln[0] = '2';
526 ln[1] = '0';
527 break;
528 default:
529 ftp_seterr(FTP_PROTOCOL_ERROR);
530 return (-1);
531 }
532 if (sscanf(ln, "%04d%02d%02d%02d%02d%02d",
533 &tm.tm_year, &tm.tm_mon, &tm.tm_mday,
534 &tm.tm_hour, &tm.tm_min, &tm.tm_sec) != 6) {
535 ftp_seterr(FTP_PROTOCOL_ERROR);
536 return (-1);
537 }
538 tm.tm_mon--;
539 tm.tm_year -= 1900;
540 tm.tm_isdst = -1;
541 t = timegm(&tm);
542 if (t == (time_t)-1)
543 t = time(NULL);
544 us->mtime = t;
545 us->atime = t;
546
547 return (0);
548 }
549
550 /*
551 * I/O functions for FTP
552 */
553 struct ftpio {
554 conn_t *cconn; /* Control connection */
555 conn_t *dconn; /* Data connection */
556 int dir; /* Direction */
557 int eof; /* EOF reached */
558 int err; /* Error code */
559 };
560
561 static ssize_t ftp_readfn(void *, void *, size_t);
562 static ssize_t ftp_writefn(void *, const void *, size_t);
563 static void ftp_closefn(void *);
564
565 static ssize_t
ftp_readfn(void * v,void * buf,size_t len)566 ftp_readfn(void *v, void *buf, size_t len)
567 {
568 struct ftpio *io;
569 ssize_t r;
570
571 io = (struct ftpio *)v;
572 if (io == NULL) {
573 errno = EBADF;
574 return (-1);
575 }
576 if (io->cconn == NULL || io->dconn == NULL || io->dir == O_WRONLY) {
577 errno = EBADF;
578 return (-1);
579 }
580 if (io->err) {
581 errno = io->err;
582 return (-1);
583 }
584 if (io->eof)
585 return (0);
586 r = fetch_read(io->dconn, buf, len);
587 if (r > 0)
588 return (r);
589 if (r == 0) {
590 io->eof = 1;
591 return (0);
592 }
593 if (errno != EINTR)
594 io->err = errno;
595 return (-1);
596 }
597
598 static ssize_t
ftp_writefn(void * v,const void * buf,size_t len)599 ftp_writefn(void *v, const void *buf, size_t len)
600 {
601 struct ftpio *io;
602 ssize_t w;
603
604 io = (struct ftpio *)v;
605 if (io == NULL) {
606 errno = EBADF;
607 return (-1);
608 }
609 if (io->cconn == NULL || io->dconn == NULL || io->dir == O_RDONLY) {
610 errno = EBADF;
611 return (-1);
612 }
613 if (io->err) {
614 errno = io->err;
615 return (-1);
616 }
617 w = fetch_write(io->dconn, buf, len);
618 if (w >= 0)
619 return (w);
620 if (errno != EINTR)
621 io->err = errno;
622 return (-1);
623 }
624
625 static int
ftp_disconnect(conn_t * conn)626 ftp_disconnect(conn_t *conn)
627 {
628 ftp_cmd(conn, "QUIT\r\n");
629 return fetch_close(conn);
630 }
631
632 static void
ftp_closefn(void * v)633 ftp_closefn(void *v)
634 {
635 struct ftpio *io;
636
637 io = (struct ftpio *)v;
638 if (io == NULL) {
639 errno = EBADF;
640 return;
641 }
642 if (io->dir == -1)
643 return;
644 if (io->cconn == NULL || io->dconn == NULL) {
645 errno = EBADF;
646 return;
647 }
648 fetch_close(io->dconn);
649 io->dconn = NULL;
650 io->dir = -1;
651 (void)ftp_chkerr(io->cconn);
652 fetch_cache_put(io->cconn, ftp_disconnect);
653 free(io);
654 return;
655 }
656
657 static fetchIO *
ftp_setup(conn_t * cconn,conn_t * dconn,int mode)658 ftp_setup(conn_t *cconn, conn_t *dconn, int mode)
659 {
660 struct ftpio *io;
661 fetchIO *f;
662
663 if (cconn == NULL || dconn == NULL)
664 return (NULL);
665 if ((io = malloc(sizeof(*io))) == NULL)
666 return (NULL);
667 io->cconn = cconn;
668 io->dconn = dconn;
669 io->dir = mode;
670 io->eof = io->err = 0;
671 f = fetchIO_unopen(io, ftp_readfn, ftp_writefn, ftp_closefn);
672 if (f == NULL)
673 free(io);
674 return (f);
675 }
676
677 /*
678 * Transfer file
679 */
680 static fetchIO *
ftp_transfer(conn_t * conn,const char * oper,const char * file,const char * op_arg,int mode,off_t offset,const char * flags)681 ftp_transfer(conn_t *conn, const char *oper, const char *file, const char *op_arg,
682 int mode, off_t offset, const char *flags)
683 {
684 union anonymous {
685 struct sockaddr_storage ss;
686 struct sockaddr sa;
687 struct sockaddr_in6 sin6;
688 struct sockaddr_in sin4;
689 } u;
690 const char *bindaddr;
691 const char *filename;
692 size_t filenamelen;
693 int type;
694 int low, pasv, verbose;
695 int e, sd = -1;
696 socklen_t l;
697 char *s;
698 fetchIO *df;
699
700 /* check flags */
701 low = CHECK_FLAG('l');
702 pasv = !CHECK_FLAG('a');
703 verbose = CHECK_FLAG('v');
704
705 /* passive mode */
706 if (!pasv)
707 pasv = ((s = getenv("FTP_PASSIVE_MODE")) != NULL &&
708 strncasecmp(s, "no", 2) != 0);
709
710 /* isolate filename */
711 filename = ftp_filename(file, &filenamelen, &type, op_arg != NULL);
712
713 /* set transfer mode and data type */
714 if ((e = ftp_mode_type(conn, 0, type)) != FTP_OK)
715 goto ouch;
716
717 /* find our own address, bind, and listen */
718 l = sizeof(u.ss);
719 if (getsockname(conn->sd, &u.sa, &l) == -1)
720 goto sysouch;
721 if (u.ss.ss_family == AF_INET6)
722 unmappedaddr(&u.sin6, &l);
723
724 retry_mode:
725
726 /* open data socket */
727 if ((sd = socket(u.ss.ss_family, SOCK_STREAM, IPPROTO_TCP)) == -1) {
728 fetch_syserr();
729 return (NULL);
730 }
731
732 if (pasv) {
733 unsigned char addr[64];
734 char *ln, *p;
735 unsigned int i;
736 int port;
737
738 /* send PASV command */
739 if (verbose)
740 fetch_info("setting passive mode");
741 switch (u.ss.ss_family) {
742 case AF_INET:
743 if ((e = ftp_cmd(conn, "PASV\r\n")) != FTP_PASSIVE_MODE)
744 goto ouch;
745 break;
746 case AF_INET6:
747 if ((e = ftp_cmd(conn, "EPSV\r\n")) != FTP_EPASSIVE_MODE) {
748 if (e == -1)
749 goto ouch;
750 if ((e = ftp_cmd(conn, "LPSV\r\n")) !=
751 FTP_LPASSIVE_MODE)
752 goto ouch;
753 }
754 break;
755 default:
756 e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
757 goto ouch;
758 }
759
760 /*
761 * Find address and port number. The reply to the PASV command
762 * is IMHO the one and only weak point in the FTP protocol.
763 */
764 ln = conn->buf;
765 switch (e) {
766 case FTP_PASSIVE_MODE:
767 case FTP_LPASSIVE_MODE:
768 for (p = ln + 3; *p && !isdigit((unsigned char)*p); p++)
769 /* nothing */ ;
770 if (!*p) {
771 e = FTP_PROTOCOL_ERROR;
772 goto ouch;
773 }
774 l = (e == FTP_PASSIVE_MODE ? 6 : 21);
775 for (i = 0; *p && i < l; i++, p++)
776 addr[i] = (unsigned char)strtol(p, &p, 10);
777 if (i < l) {
778 e = FTP_PROTOCOL_ERROR;
779 goto ouch;
780 }
781 break;
782 case FTP_EPASSIVE_MODE:
783 for (p = ln + 3; *p && *p != '('; p++)
784 /* nothing */ ;
785 if (!*p) {
786 e = FTP_PROTOCOL_ERROR;
787 goto ouch;
788 }
789 ++p;
790 if (sscanf(p, "%c%c%c%d%c", &addr[0], &addr[1], &addr[2],
791 &port, &addr[3]) != 5 ||
792 addr[0] != addr[1] ||
793 addr[0] != addr[2] || addr[0] != addr[3]) {
794 e = FTP_PROTOCOL_ERROR;
795 goto ouch;
796 }
797 break;
798 case FTP_SYNTAX_ERROR:
799 if (verbose)
800 fetch_info("passive mode failed");
801 /* Close socket and retry with passive mode. */
802 pasv = 0;
803 close(sd);
804 sd = -1;
805 goto retry_mode;
806 }
807
808 /* seek to required offset */
809 if (offset)
810 if (ftp_cmd(conn, "REST %lu\r\n", (unsigned long)offset) != FTP_FILE_OK)
811 goto sysouch;
812
813 /* construct sockaddr for data socket */
814 l = sizeof(u.ss);
815 if (getpeername(conn->sd, &u.sa, &l) == -1)
816 goto sysouch;
817 if (u.ss.ss_family == AF_INET6)
818 unmappedaddr(&u.sin6, &l);
819 switch (u.ss.ss_family) {
820 case AF_INET6:
821 if (e == FTP_EPASSIVE_MODE)
822 u.sin6.sin6_port = htons(port);
823 else {
824 memcpy(&u.sin6.sin6_addr, addr + 2, 16);
825 memcpy(&u.sin6.sin6_port, addr + 19, 2);
826 }
827 break;
828 case AF_INET:
829 if (e == FTP_EPASSIVE_MODE)
830 u.sin4.sin_port = htons(port);
831 else {
832 memcpy(&u.sin4.sin_addr, addr, 4);
833 memcpy(&u.sin4.sin_port, addr + 4, 2);
834 }
835 break;
836 default:
837 e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
838 break;
839 }
840
841 /* connect to data port */
842 if (verbose)
843 fetch_info("opening data connection");
844 bindaddr = getenv("FETCH_BIND_ADDRESS");
845 if (bindaddr != NULL && *bindaddr != '\0' &&
846 fetch_bind(sd, u.ss.ss_family, bindaddr) != 0)
847 goto sysouch;
848 if (connect(sd, &u.sa, l) == -1)
849 goto sysouch;
850
851 /* make the server initiate the transfer */
852 if (verbose)
853 fetch_info("initiating transfer");
854 if (op_arg)
855 e = ftp_cmd(conn, "%s%s%s\r\n", oper, *op_arg ? " " : "", op_arg);
856 else
857 e = ftp_cmd(conn, "%s %.*s\r\n", oper,
858 (int)filenamelen, filename);
859 if (e != FTP_CONNECTION_ALREADY_OPEN && e != FTP_OPEN_DATA_CONNECTION)
860 goto ouch;
861
862 } else {
863 uint32_t a;
864 uint16_t p;
865 #if defined(IPV6_PORTRANGE) || defined(IP_PORTRANGE)
866 int arg;
867 #endif
868 int d;
869 char hname[INET6_ADDRSTRLEN];
870
871 switch (u.ss.ss_family) {
872 case AF_INET6:
873 u.sin6.sin6_port = 0;
874 #ifdef IPV6_PORTRANGE
875 arg = low ? IPV6_PORTRANGE_DEFAULT : IPV6_PORTRANGE_HIGH;
876 if (setsockopt(sd, IPPROTO_IPV6, IPV6_PORTRANGE,
877 &arg, (socklen_t)sizeof(arg)) == -1)
878 goto sysouch;
879 #endif
880 break;
881 case AF_INET:
882 u.sin4.sin_port = 0;
883 #ifdef IP_PORTRANGE
884 arg = low ? IP_PORTRANGE_DEFAULT : IP_PORTRANGE_HIGH;
885 if (setsockopt(sd, IPPROTO_IP, IP_PORTRANGE,
886 &arg, (socklen_t)sizeof(arg)) == -1)
887 goto sysouch;
888 #endif
889 break;
890 }
891 if (verbose)
892 fetch_info("binding data socket");
893 if (bind(sd, &u.sa, l) == -1)
894 goto sysouch;
895 if (listen(sd, 1) == -1)
896 goto sysouch;
897
898 /* find what port we're on and tell the server */
899 if (getsockname(sd, &u.sa, &l) == -1)
900 goto sysouch;
901 switch (u.ss.ss_family) {
902 case AF_INET:
903 a = ntohl(u.sin4.sin_addr.s_addr);
904 p = ntohs(u.sin4.sin_port);
905 e = ftp_cmd(conn, "PORT %d,%d,%d,%d,%d,%d\r\n",
906 (a >> 24) & 0xff, (a >> 16) & 0xff,
907 (a >> 8) & 0xff, a & 0xff,
908 ((unsigned int)p >> 8) & 0xff, p & 0xff);
909 break;
910 case AF_INET6:
911 e = -1;
912 u.sin6.sin6_scope_id = 0;
913 if (getnameinfo(&u.sa, l,
914 hname, (socklen_t)sizeof(hname),
915 NULL, 0, NI_NUMERICHOST) == 0) {
916 e = ftp_cmd(conn, "EPRT |%d|%s|%d|\r\n", 2, hname,
917 htons(u.sin6.sin6_port));
918 if (e == -1)
919 goto ouch;
920 }
921 if (e != FTP_OK) {
922 uint8_t aa[sizeof(u.sin6.sin6_addr)];
923 memcpy(aa, &u.sin6.sin6_addr, sizeof(aa));
924 p = ntohs(u.sin6.sin6_port);
925 e = ftp_cmd(conn,
926 "LPRT %d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d\r\n",
927 6, 16,
928 aa[ 0], aa[ 1], aa[ 2], aa[ 3],
929 aa[ 4], aa[ 5], aa[ 6], aa[ 7],
930 aa[ 8], aa[ 9], aa[10], aa[11],
931 aa[12], aa[13], aa[14], aa[15],
932 2,
933 ((unsigned int)p >> 8) & 0xff, p & 0xff);
934 }
935 break;
936 default:
937 e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
938 goto ouch;
939 }
940 if (e != FTP_OK)
941 goto ouch;
942
943 /* seek to required offset */
944 if (offset)
945 if (ftp_cmd(conn, "REST %llu\r\n", (unsigned long long)offset) != FTP_FILE_OK)
946 goto sysouch;
947
948 /* make the server initiate the transfer */
949 if (verbose)
950 fetch_info("initiating transfer");
951 if (op_arg)
952 e = ftp_cmd(conn, "%s%s%s\r\n", oper, *op_arg ? " " : "", op_arg);
953 else
954 e = ftp_cmd(conn, "%s %.*s\r\n", oper,
955 (int)filenamelen, filename);
956 if (e != FTP_CONNECTION_ALREADY_OPEN && e != FTP_OPEN_DATA_CONNECTION)
957 goto ouch;
958
959 /* accept the incoming connection and go to town */
960 if ((d = accept(sd, NULL, NULL)) == -1)
961 goto sysouch;
962 close(sd);
963 sd = d;
964 }
965
966 if ((df = ftp_setup(conn, fetch_reopen(sd), mode)) == NULL)
967 goto sysouch;
968 return (df);
969
970 sysouch:
971 fetch_syserr();
972 if (sd >= 0)
973 close(sd);
974 return (NULL);
975
976 ouch:
977 if (e != -1)
978 ftp_seterr(e);
979 if (sd >= 0)
980 close(sd);
981 return (NULL);
982 }
983
984 /*
985 * Authenticate
986 */
987 static int
ftp_authenticate(conn_t * conn,struct url * url,struct url * purl)988 ftp_authenticate(conn_t *conn, struct url *url, struct url *purl)
989 {
990 const char *user, *pwd, *login_name;
991 char pbuf[URL_USERLEN + 1 + URL_HOSTLEN + 1];
992 int e, len;
993
994 /* XXX FTP_AUTH, and maybe .netrc */
995
996 /* send user name and password */
997 if (url->user[0] == '\0')
998 fetch_netrc_auth(url);
999 user = url->user;
1000 if (*user == '\0')
1001 user = getenv("FTP_LOGIN");
1002 if (user == NULL || *user == '\0')
1003 user = FTP_ANONYMOUS_USER;
1004 if (purl && url->port == fetch_default_port(url->scheme))
1005 e = ftp_cmd(conn, "USER %s@%s\r\n", user, url->host);
1006 else if (purl)
1007 e = ftp_cmd(conn, "USER %s@%s@%d\r\n", user, url->host, url->port);
1008 else
1009 e = ftp_cmd(conn, "USER %s\r\n", user);
1010
1011 /* did the server request a password? */
1012 if (e == FTP_NEED_PASSWORD) {
1013 pwd = url->pwd;
1014 if (*pwd == '\0')
1015 pwd = getenv("FTP_PASSWORD");
1016 if (pwd == NULL || *pwd == '\0') {
1017 if ((login_name = getlogin()) == 0)
1018 login_name = FTP_ANONYMOUS_USER;
1019 if ((len = snprintf(pbuf, URL_USERLEN + 2, "%s@", login_name)) < 0)
1020 len = 0;
1021 else if (len > URL_USERLEN + 1)
1022 len = URL_USERLEN + 1;
1023 gethostname(pbuf + len, sizeof(pbuf) - len);
1024 /* MAXHOSTNAMELEN can differ from URL_HOSTLEN + 1 */
1025 pbuf[sizeof(pbuf) - 1] = '\0';
1026 pwd = pbuf;
1027 }
1028 e = ftp_cmd(conn, "PASS %s\r\n", pwd);
1029 }
1030
1031 return (e);
1032 }
1033
1034 /*
1035 * Log on to FTP server
1036 */
1037 static conn_t *
ftp_connect(struct url * url,struct url * purl,const char * flags)1038 ftp_connect(struct url *url, struct url *purl, const char *flags)
1039 {
1040 conn_t *conn;
1041 int e, direct, verbose;
1042 #ifdef INET6
1043 int af = AF_UNSPEC;
1044 #else
1045 int af = AF_INET;
1046 #endif
1047
1048 direct = CHECK_FLAG('d');
1049 verbose = CHECK_FLAG('v');
1050 if (CHECK_FLAG('4'))
1051 af = AF_INET;
1052 else if (CHECK_FLAG('6'))
1053 af = AF_INET6;
1054
1055 if (direct)
1056 purl = NULL;
1057
1058 /* check for proxy */
1059 if (purl) {
1060 /* XXX proxy authentication! */
1061 /* XXX connetion caching */
1062 if (!purl->port)
1063 purl->port = fetch_default_port(purl->scheme);
1064
1065 conn = fetch_connect(purl, af, verbose);
1066 } else {
1067 /* no proxy, go straight to target */
1068 if (!url->port)
1069 url->port = fetch_default_port(url->scheme);
1070
1071 while ((conn = fetch_cache_get(url, af)) != NULL) {
1072 e = ftp_cmd(conn, "NOOP\r\n");
1073 if (e == FTP_OK)
1074 return conn;
1075 fetch_close(conn);
1076 }
1077 conn = fetch_connect(url, af, verbose);
1078 purl = NULL;
1079 }
1080
1081 /* check connection */
1082 if (conn == NULL)
1083 /* fetch_connect() has already set an error code */
1084 return (NULL);
1085
1086 /* expect welcome message */
1087 if ((e = ftp_chkerr(conn)) != FTP_SERVICE_READY)
1088 goto fouch;
1089
1090 /* authenticate */
1091 if ((e = ftp_authenticate(conn, url, purl)) != FTP_LOGGED_IN)
1092 goto fouch;
1093
1094 /* TODO: Request extended features supported, if any (RFC 3659). */
1095
1096 /* done */
1097 return (conn);
1098
1099 fouch:
1100 if (e != -1)
1101 ftp_seterr(e);
1102 fetch_close(conn);
1103 return (NULL);
1104 }
1105
1106 /*
1107 * Check the proxy settings
1108 */
1109 static struct url *
ftp_get_proxy(struct url * url,const char * flags)1110 ftp_get_proxy(struct url * url, const char *flags)
1111 {
1112 struct url *purl;
1113 char *p, *fp, *FP, *hp, *HP;
1114
1115 if (flags != NULL && strchr(flags, 'd') != NULL)
1116 return NULL;
1117 if (fetch_no_proxy_match(url->host))
1118 return NULL;
1119
1120 FP = getenv("FTP_PROXY");
1121 fp = getenv("ftp_proxy");
1122 HP = getenv("HTTP_PROXY");
1123 hp = getenv("http_proxy");
1124
1125 if ((((p = FP) || (p = fp) || (p = HP) || (p = hp))) &&
1126 *p && (purl = fetchParseURL(p)) != NULL) {
1127 if (!*purl->scheme) {
1128 if (fp || FP)
1129 strcpy(purl->scheme, SCHEME_FTP);
1130 else
1131 strcpy(purl->scheme, SCHEME_HTTP);
1132 }
1133 if (!purl->port)
1134 purl->port = fetch_default_proxy_port(purl->scheme);
1135 if (strcasecmp(purl->scheme, SCHEME_FTP) == 0 ||
1136 strcasecmp(purl->scheme, SCHEME_HTTP) == 0)
1137 return purl;
1138 fetchFreeURL(purl);
1139 }
1140 return NULL;
1141 }
1142
1143 /*
1144 * Process an FTP request
1145 */
1146 fetchIO *
ftp_request(struct url * url,const char * op,const char * op_arg,struct url_stat * us,struct url * purl,const char * flags)1147 ftp_request(struct url *url, const char *op, const char *op_arg,
1148 struct url_stat *us, struct url *purl, const char *flags)
1149 {
1150 fetchIO *f;
1151 char *path;
1152 conn_t *conn;
1153 int if_modified_since, oflag;
1154 struct url_stat local_us;
1155
1156 /* check if we should use HTTP instead */
1157 if (purl && strcasecmp(purl->scheme, SCHEME_HTTP) == 0) {
1158 if (strcmp(op, "STAT") == 0)
1159 return (http_request(url, "HEAD", us, purl, flags));
1160 else if (strcmp(op, "RETR") == 0)
1161 return (http_request(url, "GET", us, purl, flags));
1162 /*
1163 * Our HTTP code doesn't support PUT requests yet, so try
1164 * a direct connection.
1165 */
1166 }
1167
1168 /* connect to server */
1169 conn = ftp_connect(url, purl, flags);
1170 if (purl)
1171 fetchFreeURL(purl);
1172 if (conn == NULL)
1173 return (NULL);
1174
1175 if ((path = fetchUnquotePath(url)) == NULL) {
1176 fetch_close(conn);
1177 fetch_syserr();
1178 return NULL;
1179 }
1180
1181 /* change directory */
1182 if (ftp_cwd(conn, path, op_arg != NULL) == -1) {
1183 fetch_close(conn);
1184 free(path);
1185 return (NULL);
1186 }
1187
1188 if_modified_since = CHECK_FLAG('i');
1189 if (if_modified_since && us == NULL)
1190 us = &local_us;
1191
1192 /* stat file */
1193 if (us && ftp_stat(conn, path, us) == -1
1194 && fetchLastErrCode != FETCH_PROTO
1195 && fetchLastErrCode != FETCH_UNAVAIL) {
1196 fetch_close(conn);
1197 free(path);
1198 return (NULL);
1199 }
1200
1201 if (if_modified_since && url->last_modified > 0 &&
1202 url->last_modified >= us->mtime) {
1203 fetch_cache_put(conn, ftp_disconnect);
1204 free(path);
1205 fetchLastErrCode = FETCH_UNCHANGED;
1206 snprintf(fetchLastErrString, MAXERRSTRING, "Unchanged");
1207 return NULL;
1208 }
1209
1210 /* just a stat */
1211 if (strcmp(op, "STAT") == 0) {
1212 fetch_cache_put(conn, ftp_disconnect);
1213 free(path);
1214 return fetchIO_unopen(NULL, NULL, NULL, NULL);
1215 }
1216 if (strcmp(op, "STOR") == 0 || strcmp(op, "APPE") == 0)
1217 oflag = O_WRONLY;
1218 else
1219 oflag = O_RDONLY;
1220
1221 /* initiate the transfer */
1222 f = (ftp_transfer(conn, op, path, op_arg, oflag, url->offset, flags));
1223 free(path);
1224 return f;
1225 }
1226
1227 /*
1228 * Get and stat file
1229 */
1230 fetchIO *
fetchXGetFTP(struct url * url,struct url_stat * us,const char * flags)1231 fetchXGetFTP(struct url *url, struct url_stat *us, const char *flags)
1232 {
1233 return (ftp_request(url, "RETR", NULL, us, ftp_get_proxy(url, flags), flags));
1234 }
1235
1236 /*
1237 * Get file
1238 */
1239 fetchIO *
fetchGetFTP(struct url * url,const char * flags)1240 fetchGetFTP(struct url *url, const char *flags)
1241 {
1242 return (fetchXGetFTP(url, NULL, flags));
1243 }
1244
1245 /*
1246 * Put file
1247 */
1248 fetchIO *
fetchPutFTP(struct url * url,const char * flags)1249 fetchPutFTP(struct url *url, const char *flags)
1250 {
1251 return (ftp_request(url, CHECK_FLAG('a') ? "APPE" : "STOR", NULL, NULL,
1252 ftp_get_proxy(url, flags), flags));
1253 }
1254
1255 /*
1256 * Get file stats
1257 */
1258 int
fetchStatFTP(struct url * url,struct url_stat * us,const char * flags)1259 fetchStatFTP(struct url *url, struct url_stat *us, const char *flags)
1260 {
1261 fetchIO *f;
1262
1263 f = ftp_request(url, "STAT", NULL, us, ftp_get_proxy(url, flags), flags);
1264 if (f == NULL)
1265 return (-1);
1266 fetchIO_close(f);
1267 return (0);
1268 }
1269
1270 /*
1271 * List a directory
1272 */
1273 int
fetchListFTP(struct url_list * ue,struct url * url,const char * pattern,const char * flags)1274 fetchListFTP(struct url_list *ue, struct url *url, const char *pattern, const char *flags)
1275 {
1276 fetchIO *f;
1277 char buf[2 * PATH_MAX], *eol, *eos;
1278 ssize_t len;
1279 size_t cur_off;
1280 int ret;
1281
1282 /* XXX What about proxies? */
1283 if (pattern == NULL || strcmp(pattern, "*") == 0)
1284 pattern = "";
1285 f = ftp_request(url, "NLST", pattern, NULL, ftp_get_proxy(url, flags), flags);
1286 if (f == NULL)
1287 return -1;
1288
1289 cur_off = 0;
1290 ret = 0;
1291
1292 while ((len = fetchIO_read(f, buf + cur_off, sizeof(buf) - cur_off)) > 0) {
1293 cur_off += len;
1294 while ((eol = memchr(buf, '\n', cur_off)) != NULL) {
1295 if (len == eol - buf)
1296 break;
1297 if (eol != buf) {
1298 if (eol[-1] == '\r')
1299 eos = eol - 1;
1300 else
1301 eos = eol;
1302 *eos = '\0';
1303 ret = fetch_add_entry(ue, url, buf, 0);
1304 if (ret)
1305 break;
1306 cur_off -= eol - buf + 1;
1307 memmove(buf, eol + 1, cur_off);
1308 }
1309 }
1310 if (ret)
1311 break;
1312 }
1313 if (cur_off != 0 || len < 0) {
1314 /* Not RFC conform, bail out. */
1315 fetchIO_close(f);
1316 return -1;
1317 }
1318 fetchIO_close(f);
1319 return ret;
1320 }
1321