1 /*-
2 * SPDX-License-Identifier: (BSD-3-Clause AND Beerware)
3 *
4 * Copyright (c) 1998-2011 Dag-Erling Smørgrav
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 #include "bsd_compat.h"
33 __FBSDID("$FreeBSD: head/lib/libfetch/ftp.c 341013 2018-11-27 10:45:14Z des $");
34
35 /*
36 * Portions of this code were taken from or based on ftpio.c:
37 *
38 * ----------------------------------------------------------------------------
39 * "THE BEER-WARE LICENSE" (Revision 42):
40 * <phk@FreeBSD.org> wrote this file. As long as you retain this notice you
41 * can do whatever you want with this stuff. If we meet some day, and you think
42 * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
43 * ----------------------------------------------------------------------------
44 *
45 * Major Changelog:
46 *
47 * Dag-Erling Smørgrav
48 * 9 Jun 1998
49 *
50 * Incorporated into libfetch
51 *
52 * Jordan K. Hubbard
53 * 17 Jan 1996
54 *
55 * Turned inside out. Now returns xfers as new file ids, not as a special
56 * `state' of FTP_t
57 *
58 * $ftpioId: ftpio.c,v 1.30 1998/04/11 07:28:53 phk Exp $
59 *
60 */
61
62 #include <sys/param.h>
63 #include <sys/socket.h>
64 #include <netinet/in.h>
65
66 #include <ctype.h>
67 #include <err.h>
68 #include <errno.h>
69 #include <fcntl.h>
70 #include <netdb.h>
71 #include <stdarg.h>
72 #include <stdint.h>
73 #include <stdio.h>
74 #include <stdlib.h>
75 #include <string.h>
76 #include <time.h>
77 #include <unistd.h>
78
79 #include "fetch.h"
80 #include "common.h"
81 #include "ftperr.h"
82
83 #define FTP_ANONYMOUS_USER "anonymous"
84
85 #define FTP_CONNECTION_ALREADY_OPEN 125
86 #define FTP_OPEN_DATA_CONNECTION 150
87 #define FTP_OK 200
88 #define FTP_FILE_STATUS 213
89 #define FTP_SERVICE_READY 220
90 #define FTP_TRANSFER_COMPLETE 226
91 #define FTP_PASSIVE_MODE 227
92 #define FTP_LPASSIVE_MODE 228
93 #define FTP_EPASSIVE_MODE 229
94 #define FTP_LOGGED_IN 230
95 #define FTP_FILE_ACTION_OK 250
96 #define FTP_DIRECTORY_CREATED 257 /* multiple meanings */
97 #define FTP_FILE_CREATED 257 /* multiple meanings */
98 #define FTP_WORKING_DIRECTORY 257 /* multiple meanings */
99 #define FTP_NEED_PASSWORD 331
100 #define FTP_NEED_ACCOUNT 332
101 #define FTP_FILE_OK 350
102 #define FTP_SYNTAX_ERROR 500
103 #define FTP_PROTOCOL_ERROR 999
104
105 static struct url cached_host;
106 static conn_t *cached_connection;
107
108 #define isftpreply(foo) \
109 (isdigit((unsigned char)foo[0]) && \
110 isdigit((unsigned char)foo[1]) && \
111 isdigit((unsigned char)foo[2]) && \
112 (foo[3] == ' ' || foo[3] == '\0'))
113 #define isftpinfo(foo) \
114 (isdigit((unsigned char)foo[0]) && \
115 isdigit((unsigned char)foo[1]) && \
116 isdigit((unsigned char)foo[2]) && \
117 foo[3] == '-')
118
119 /*
120 * Translate IPv4 mapped IPv6 address to IPv4 address
121 */
122 static void
unmappedaddr(struct sockaddr_in6 * sin6)123 unmappedaddr(struct sockaddr_in6 *sin6)
124 {
125 struct sockaddr_in *sin4;
126 u_int32_t addr;
127 int port;
128
129 if (sin6->sin6_family != AF_INET6 ||
130 !IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
131 return;
132 sin4 = (struct sockaddr_in *)sin6;
133 addr = *(u_int32_t *)(uintptr_t)&sin6->sin6_addr.s6_addr[12];
134 port = sin6->sin6_port;
135 memset(sin4, 0, sizeof(struct sockaddr_in));
136 sin4->sin_addr.s_addr = addr;
137 sin4->sin_port = port;
138 sin4->sin_family = AF_INET;
139 #ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LE
140 sin4->sin_len = sizeof(struct sockaddr_in);
141 #endif
142 }
143
144 /*
145 * Get server response
146 */
147 static int
ftp_chkerr(conn_t * conn)148 ftp_chkerr(conn_t *conn)
149 {
150 if (fetch_getln(conn) == -1) {
151 fetch_syserr();
152 return (-1);
153 }
154 if (isftpinfo(conn->buf)) {
155 while (conn->buflen && !isftpreply(conn->buf)) {
156 if (fetch_getln(conn) == -1) {
157 fetch_syserr();
158 return (-1);
159 }
160 }
161 }
162
163 while (conn->buflen &&
164 isspace((unsigned char)conn->buf[conn->buflen - 1]))
165 conn->buflen--;
166 conn->buf[conn->buflen] = '\0';
167
168 if (!isftpreply(conn->buf)) {
169 ftp_seterr(FTP_PROTOCOL_ERROR);
170 return (-1);
171 }
172
173 conn->err = (conn->buf[0] - '0') * 100
174 + (conn->buf[1] - '0') * 10
175 + (conn->buf[2] - '0');
176
177 return (conn->err);
178 }
179
180 /*
181 * Send a command and check reply
182 */
183 static int
ftp_cmd(conn_t * conn,const char * fmt,...)184 ftp_cmd(conn_t *conn, const char *fmt, ...)
185 {
186 va_list ap;
187 size_t len;
188 char *msg;
189 int r;
190
191 va_start(ap, fmt);
192 len = vasprintf(&msg, fmt, ap);
193 va_end(ap);
194
195 if (msg == NULL) {
196 errno = ENOMEM;
197 fetch_syserr();
198 return (-1);
199 }
200
201 r = fetch_putln(conn, msg, len);
202 free(msg);
203
204 if (r == -1) {
205 fetch_syserr();
206 return (-1);
207 }
208
209 return (ftp_chkerr(conn));
210 }
211
212 /*
213 * Return a pointer to the filename part of a path
214 */
215 static const char *
ftp_filename(const char * file,int * len,int * type)216 ftp_filename(const char *file, int *len, int *type)
217 {
218 const char *s;
219
220 if ((s = strrchr(file, '/')) == NULL)
221 s = file;
222 else
223 s = s + 1;
224 *len = strlen(s);
225 if (*len > 7 && strncmp(s + *len - 7, ";type=", 6) == 0) {
226 *type = s[*len - 1];
227 *len -= 7;
228 } else {
229 *type = '\0';
230 }
231 return (s);
232 }
233
234 /*
235 * Get current working directory from the reply to a CWD, PWD or CDUP
236 * command.
237 */
238 static int
ftp_pwd(conn_t * conn,char * pwd,size_t pwdlen)239 ftp_pwd(conn_t *conn, char *pwd, size_t pwdlen)
240 {
241 char *src, *dst, *end;
242 int q;
243
244 if (conn->err != FTP_WORKING_DIRECTORY &&
245 conn->err != FTP_FILE_ACTION_OK)
246 return (FTP_PROTOCOL_ERROR);
247 end = conn->buf + conn->buflen;
248 src = conn->buf + 4;
249 if (src >= end || *src++ != '"')
250 return (FTP_PROTOCOL_ERROR);
251 for (q = 0, dst = pwd; src < end && pwdlen--; ++src) {
252 if (!q && *src == '"')
253 q = 1;
254 else if (q && *src != '"')
255 break;
256 else if (q)
257 *dst++ = '"', q = 0;
258 else
259 *dst++ = *src;
260 }
261 if (!pwdlen)
262 return (FTP_PROTOCOL_ERROR);
263 *dst = '\0';
264 #if 0
265 DEBUGF("pwd: [%s]\n", pwd);
266 #endif
267 return (FTP_OK);
268 }
269
270 /*
271 * Change working directory to the directory that contains the specified
272 * file.
273 */
274 static int
ftp_cwd(conn_t * conn,const char * file)275 ftp_cwd(conn_t *conn, const char *file)
276 {
277 const char *beg, *end;
278 char pwd[PATH_MAX];
279 int e, i, len;
280
281 /* If no slashes in name, no need to change dirs. */
282 if ((end = strrchr(file, '/')) == NULL)
283 return (0);
284 if ((e = ftp_cmd(conn, "PWD")) != FTP_WORKING_DIRECTORY ||
285 (e = ftp_pwd(conn, pwd, sizeof(pwd))) != FTP_OK) {
286 ftp_seterr(e);
287 return (-1);
288 }
289 for (;;) {
290 len = strlen(pwd);
291
292 /* Look for a common prefix between PWD and dir to fetch. */
293 for (i = 0; i <= len && i <= end - file; ++i)
294 if (pwd[i] != file[i])
295 break;
296 #if 0
297 DEBUGF("have: [%.*s|%s]\n", i, pwd, pwd + i);
298 DEBUGF("want: [%.*s|%s]\n", i, file, file + i);
299 #endif
300 /* Keep going up a dir until we have a matching prefix. */
301 if (pwd[i] == '\0' && (file[i - 1] == '/' || file[i] == '/'))
302 break;
303 if ((e = ftp_cmd(conn, "CDUP")) != FTP_FILE_ACTION_OK ||
304 (e = ftp_cmd(conn, "PWD")) != FTP_WORKING_DIRECTORY ||
305 (e = ftp_pwd(conn, pwd, sizeof(pwd))) != FTP_OK) {
306 ftp_seterr(e);
307 return (-1);
308 }
309 }
310
311 #ifdef FTP_COMBINE_CWDS
312 /* Skip leading slashes, even "////". */
313 for (beg = file + i; beg < end && *beg == '/'; ++beg, ++i)
314 /* nothing */ ;
315
316 /* If there is no trailing dir, we're already there. */
317 if (beg >= end)
318 return (0);
319
320 /* Change to the directory all in one chunk (e.g., foo/bar/baz). */
321 e = ftp_cmd(conn, "CWD %.*s", (int)(end - beg), beg);
322 if (e == FTP_FILE_ACTION_OK)
323 return (0);
324 #endif /* FTP_COMBINE_CWDS */
325
326 /* That didn't work so go back to legacy behavior (multiple CWDs). */
327 for (beg = file + i; beg < end; beg = file + i + 1) {
328 while (*beg == '/')
329 ++beg, ++i;
330 for (++i; file + i < end && file[i] != '/'; ++i)
331 /* nothing */ ;
332 e = ftp_cmd(conn, "CWD %.*s", file + i - beg, beg);
333 if (e != FTP_FILE_ACTION_OK) {
334 ftp_seterr(e);
335 return (-1);
336 }
337 }
338 return (0);
339 }
340
341 /*
342 * Set transfer mode and data type
343 */
344 static int
ftp_mode_type(conn_t * conn,int mode,int type)345 ftp_mode_type(conn_t *conn, int mode, int type)
346 {
347 int e;
348
349 switch (mode) {
350 case 0:
351 case 's':
352 mode = 'S';
353 case 'S':
354 break;
355 default:
356 return (FTP_PROTOCOL_ERROR);
357 }
358 if ((e = ftp_cmd(conn, "MODE %c", mode)) != FTP_OK) {
359 if (mode == 'S') {
360 /*
361 * Stream mode is supposed to be the default - so
362 * much so that some servers not only do not
363 * support any other mode, but do not support the
364 * MODE command at all.
365 *
366 * If "MODE S" fails, it is unlikely that we
367 * previously succeeded in setting a different
368 * mode. Therefore, we simply hope that the
369 * server is already in the correct mode, and
370 * silently ignore the failure.
371 */
372 } else {
373 return (e);
374 }
375 }
376
377 switch (type) {
378 case 0:
379 case 'i':
380 type = 'I';
381 case 'I':
382 break;
383 case 'a':
384 type = 'A';
385 case 'A':
386 break;
387 case 'd':
388 type = 'D';
389 case 'D':
390 /* can't handle yet */
391 default:
392 return (FTP_PROTOCOL_ERROR);
393 }
394 if ((e = ftp_cmd(conn, "TYPE %c", type)) != FTP_OK)
395 return (e);
396
397 return (FTP_OK);
398 }
399
400 /*
401 * Request and parse file stats
402 */
403 static int
ftp_stat(conn_t * conn,const char * file,struct url_stat * us)404 ftp_stat(conn_t *conn, const char *file, struct url_stat *us)
405 {
406 char *ln;
407 const char *filename;
408 int filenamelen, type;
409 struct tm tm;
410 time_t t;
411 int e;
412
413 us->size = -1;
414 us->atime = us->mtime = 0;
415
416 filename = ftp_filename(file, &filenamelen, &type);
417
418 if ((e = ftp_mode_type(conn, 0, type)) != FTP_OK) {
419 ftp_seterr(e);
420 return (-1);
421 }
422
423 e = ftp_cmd(conn, "SIZE %.*s", filenamelen, filename);
424 if (e != FTP_FILE_STATUS) {
425 ftp_seterr(e);
426 return (-1);
427 }
428 for (ln = conn->buf + 4; *ln && isspace((unsigned char)*ln); ln++)
429 /* nothing */ ;
430 for (us->size = 0; *ln && isdigit((unsigned char)*ln); ln++)
431 us->size = us->size * 10 + *ln - '0';
432 if (*ln && !isspace((unsigned char)*ln)) {
433 ftp_seterr(FTP_PROTOCOL_ERROR);
434 us->size = -1;
435 return (-1);
436 }
437 if (us->size == 0)
438 us->size = -1;
439 DEBUGF("size: [%lld]\n", (long long)us->size);
440
441 e = ftp_cmd(conn, "MDTM %.*s", filenamelen, filename);
442 if (e != FTP_FILE_STATUS) {
443 ftp_seterr(e);
444 return (-1);
445 }
446 for (ln = conn->buf + 4; *ln && isspace((unsigned char)*ln); ln++)
447 /* nothing */ ;
448 switch (strspn(ln, "0123456789")) {
449 case 14:
450 break;
451 case 15:
452 ln++;
453 ln[0] = '2';
454 ln[1] = '0';
455 break;
456 default:
457 ftp_seterr(FTP_PROTOCOL_ERROR);
458 return (-1);
459 }
460 if (sscanf(ln, "%04d%02d%02d%02d%02d%02d",
461 &tm.tm_year, &tm.tm_mon, &tm.tm_mday,
462 &tm.tm_hour, &tm.tm_min, &tm.tm_sec) != 6) {
463 ftp_seterr(FTP_PROTOCOL_ERROR);
464 return (-1);
465 }
466 tm.tm_mon--;
467 tm.tm_year -= 1900;
468 tm.tm_isdst = -1;
469 t = timegm(&tm);
470 if (t == (time_t)-1)
471 t = time(NULL);
472 us->mtime = t;
473 us->atime = t;
474 DEBUGF("last modified: [%04d-%02d-%02d %02d:%02d:%02d]\n",
475 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
476 tm.tm_hour, tm.tm_min, tm.tm_sec);
477 return (0);
478 }
479
480 /*
481 * I/O functions for FTP
482 */
483 struct ftpio {
484 conn_t *cconn; /* Control connection */
485 conn_t *dconn; /* Data connection */
486 int dir; /* Direction */
487 int eof; /* EOF reached */
488 int err; /* Error code */
489 };
490
491 static int ftp_readfn(void *, char *, int);
492 static int ftp_writefn(void *, const char *, int);
493 static off_t ftp_seekfn(void *, off_t, int);
494 static int ftp_closefn(void *);
495
496 static int
ftp_readfn(void * v,char * buf,int len)497 ftp_readfn(void *v, char *buf, int len)
498 {
499 struct ftpio *io;
500 int r;
501
502 io = (struct ftpio *)v;
503 if (io == NULL) {
504 errno = EBADF;
505 return (-1);
506 }
507 if (io->cconn == NULL || io->dconn == NULL || io->dir == O_WRONLY) {
508 errno = EBADF;
509 return (-1);
510 }
511 if (io->err) {
512 errno = io->err;
513 return (-1);
514 }
515 if (io->eof)
516 return (0);
517 r = fetch_read(io->dconn, buf, len);
518 if (r > 0)
519 return (r);
520 if (r == 0) {
521 io->eof = 1;
522 return (0);
523 }
524 if (errno != EINTR)
525 io->err = errno;
526 return (-1);
527 }
528
529 static int
ftp_writefn(void * v,const char * buf,int len)530 ftp_writefn(void *v, const char *buf, int len)
531 {
532 struct ftpio *io;
533 int w;
534
535 io = (struct ftpio *)v;
536 if (io == NULL) {
537 errno = EBADF;
538 return (-1);
539 }
540 if (io->cconn == NULL || io->dconn == NULL || io->dir == O_RDONLY) {
541 errno = EBADF;
542 return (-1);
543 }
544 if (io->err) {
545 errno = io->err;
546 return (-1);
547 }
548 w = fetch_write(io->dconn, buf, len);
549 if (w >= 0)
550 return (w);
551 if (errno != EINTR)
552 io->err = errno;
553 return (-1);
554 }
555
556 static off_t
ftp_seekfn(void * v,off_t pos __unused,int whence __unused)557 ftp_seekfn(void *v, off_t pos __unused, int whence __unused)
558 {
559 struct ftpio *io;
560
561 io = (struct ftpio *)v;
562 if (io == NULL) {
563 errno = EBADF;
564 return ((off_t)-1);
565 }
566 errno = ESPIPE;
567 return ((off_t)-1);
568 }
569
570 static int
ftp_closefn(void * v)571 ftp_closefn(void *v)
572 {
573 struct ftpio *io;
574 int r;
575
576 io = (struct ftpio *)v;
577 if (io == NULL) {
578 errno = EBADF;
579 return (-1);
580 }
581 if (io->dir == -1)
582 return (0);
583 if (io->cconn == NULL || io->dconn == NULL) {
584 errno = EBADF;
585 return (-1);
586 }
587 fetch_close(io->dconn);
588 io->dir = -1;
589 io->dconn = NULL;
590 DEBUGF("Waiting for final status\n");
591 r = ftp_chkerr(io->cconn);
592 if (io->cconn == cached_connection && io->cconn->ref == 1)
593 cached_connection = NULL;
594 fetch_close(io->cconn);
595 free(io);
596 return (r == FTP_TRANSFER_COMPLETE) ? 0 : -1;
597 }
598
599 static FILE *
ftp_setup(conn_t * cconn,conn_t * dconn,int mode)600 ftp_setup(conn_t *cconn, conn_t *dconn, int mode)
601 {
602 struct ftpio *io;
603 FILE *f;
604
605 if (cconn == NULL || dconn == NULL)
606 return (NULL);
607 if ((io = malloc(sizeof(*io))) == NULL)
608 return (NULL);
609 io->cconn = cconn;
610 io->dconn = dconn;
611 io->dir = mode;
612 io->eof = io->err = 0;
613 f = funopen(io, ftp_readfn, ftp_writefn, ftp_seekfn, ftp_closefn);
614 if (f == NULL)
615 free(io);
616 return (f);
617 }
618
619 /*
620 * Transfer file
621 */
622 static FILE *
ftp_transfer(conn_t * conn,const char * oper,const char * file,int mode,off_t offset,const char * flags)623 ftp_transfer(conn_t *conn, const char *oper, const char *file,
624 int mode, off_t offset, const char *flags)
625 {
626 struct sockaddr_storage sa;
627 struct sockaddr_in6 *sin6;
628 struct sockaddr_in *sin4;
629 const char *bindaddr;
630 const char *filename;
631 int filenamelen, type;
632 int low, pasv, verbose;
633 int e, sd = -1;
634 socklen_t l;
635 char *s;
636 FILE *df;
637
638 /* check flags */
639 low = CHECK_FLAG('l');
640 pasv = CHECK_FLAG('p') || !CHECK_FLAG('P');
641 verbose = CHECK_FLAG('v');
642
643 /* passive mode */
644 if ((s = getenv("FTP_PASSIVE_MODE")) != NULL)
645 pasv = (strncasecmp(s, "no", 2) != 0);
646
647 /* isolate filename */
648 filename = ftp_filename(file, &filenamelen, &type);
649
650 /* set transfer mode and data type */
651 if ((e = ftp_mode_type(conn, 0, type)) != FTP_OK)
652 goto ouch;
653
654 /* find our own address, bind, and listen */
655 l = sizeof(sa);
656 if (getsockname(conn->sd, (struct sockaddr *)&sa, &l) == -1)
657 goto sysouch;
658 if (sa.ss_family == AF_INET6)
659 unmappedaddr((struct sockaddr_in6 *)&sa);
660
661 /* open data socket */
662 if ((sd = socket(sa.ss_family, SOCK_STREAM, IPPROTO_TCP)) == -1) {
663 fetch_syserr();
664 return (NULL);
665 }
666
667 if (pasv) {
668 u_char addr[64];
669 char *ln, *p;
670 unsigned int i;
671 int port;
672
673 /* send PASV command */
674 if (verbose)
675 fetch_info("setting passive mode");
676 switch (sa.ss_family) {
677 case AF_INET:
678 if ((e = ftp_cmd(conn, "PASV")) != FTP_PASSIVE_MODE)
679 goto ouch;
680 break;
681 case AF_INET6:
682 if ((e = ftp_cmd(conn, "EPSV")) != FTP_EPASSIVE_MODE) {
683 if (e == -1)
684 goto ouch;
685 if ((e = ftp_cmd(conn, "LPSV")) !=
686 FTP_LPASSIVE_MODE)
687 goto ouch;
688 }
689 break;
690 default:
691 e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
692 goto ouch;
693 }
694
695 /*
696 * Find address and port number. The reply to the PASV command
697 * is IMHO the one and only weak point in the FTP protocol.
698 */
699 ln = conn->buf;
700 switch (e) {
701 case FTP_PASSIVE_MODE:
702 case FTP_LPASSIVE_MODE:
703 for (p = ln + 3; *p && !isdigit((unsigned char)*p); p++)
704 /* nothing */ ;
705 if (!*p) {
706 e = FTP_PROTOCOL_ERROR;
707 goto ouch;
708 }
709 l = (e == FTP_PASSIVE_MODE ? 6 : 21);
710 for (i = 0; *p && i < l; i++, p++)
711 addr[i] = strtol(p, &p, 10);
712 if (i < l) {
713 e = FTP_PROTOCOL_ERROR;
714 goto ouch;
715 }
716 break;
717 case FTP_EPASSIVE_MODE:
718 for (p = ln + 3; *p && *p != '('; p++)
719 /* nothing */ ;
720 if (!*p) {
721 e = FTP_PROTOCOL_ERROR;
722 goto ouch;
723 }
724 ++p;
725 if (sscanf(p, "%c%c%c%d%c", &addr[0], &addr[1], &addr[2],
726 &port, &addr[3]) != 5 ||
727 addr[0] != addr[1] ||
728 addr[0] != addr[2] || addr[0] != addr[3]) {
729 e = FTP_PROTOCOL_ERROR;
730 goto ouch;
731 }
732 break;
733 }
734
735 /* seek to required offset */
736 if (offset)
737 if (ftp_cmd(conn, "REST %lu", (u_long)offset) != FTP_FILE_OK)
738 goto sysouch;
739
740 /* construct sockaddr for data socket */
741 l = sizeof(sa);
742 if (getpeername(conn->sd, (struct sockaddr *)&sa, &l) == -1)
743 goto sysouch;
744 if (sa.ss_family == AF_INET6)
745 unmappedaddr((struct sockaddr_in6 *)&sa);
746 switch (sa.ss_family) {
747 case AF_INET6:
748 sin6 = (struct sockaddr_in6 *)&sa;
749 if (e == FTP_EPASSIVE_MODE)
750 sin6->sin6_port = htons(port);
751 else {
752 memcpy(&sin6->sin6_addr, addr + 2, 16);
753 memcpy(&sin6->sin6_port, addr + 19, 2);
754 }
755 break;
756 case AF_INET:
757 sin4 = (struct sockaddr_in *)&sa;
758 if (e == FTP_EPASSIVE_MODE)
759 sin4->sin_port = htons(port);
760 else {
761 memcpy(&sin4->sin_addr, addr, 4);
762 memcpy(&sin4->sin_port, addr + 4, 2);
763 }
764 break;
765 default:
766 e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
767 break;
768 }
769
770 /* connect to data port */
771 if (verbose)
772 fetch_info("opening data connection");
773 bindaddr = getenv("FETCH_BIND_ADDRESS");
774 if (bindaddr != NULL && *bindaddr != '\0' &&
775 (e = fetch_bind(sd, sa.ss_family, bindaddr)) != 0)
776 goto ouch;
777 if (connect(sd, (struct sockaddr *)&sa, l) == -1)
778 goto sysouch;
779
780 /* make the server initiate the transfer */
781 if (verbose)
782 fetch_info("initiating transfer");
783 e = ftp_cmd(conn, "%s %.*s", oper, filenamelen, filename);
784 if (e != FTP_CONNECTION_ALREADY_OPEN && e != FTP_OPEN_DATA_CONNECTION)
785 goto ouch;
786
787 } else {
788 u_int32_t a;
789 u_short p;
790 int arg, d;
791 char *ap;
792 char hname[INET6_ADDRSTRLEN];
793
794 switch (sa.ss_family) {
795 case AF_INET6:
796 ((struct sockaddr_in6 *)&sa)->sin6_port = 0;
797 #ifdef IPV6_PORTRANGE
798 arg = low ? IPV6_PORTRANGE_DEFAULT : IPV6_PORTRANGE_HIGH;
799 if (setsockopt(sd, IPPROTO_IPV6, IPV6_PORTRANGE,
800 (char *)&arg, sizeof(arg)) == -1)
801 goto sysouch;
802 #endif
803 break;
804 case AF_INET:
805 ((struct sockaddr_in *)&sa)->sin_port = 0;
806 #ifdef IP_PORTRANGE
807 arg = low ? IP_PORTRANGE_DEFAULT : IP_PORTRANGE_HIGH;
808 if (setsockopt(sd, IPPROTO_IP, IP_PORTRANGE,
809 (char *)&arg, sizeof(arg)) == -1)
810 goto sysouch;
811 #endif
812 break;
813 }
814 if (verbose)
815 fetch_info("binding data socket");
816 if (bind(sd, (struct sockaddr *)&sa, l) == -1)
817 goto sysouch;
818 if (listen(sd, 1) == -1)
819 goto sysouch;
820
821 /* find what port we're on and tell the server */
822 if (getsockname(sd, (struct sockaddr *)&sa, &l) == -1)
823 goto sysouch;
824 switch (sa.ss_family) {
825 case AF_INET:
826 sin4 = (struct sockaddr_in *)&sa;
827 a = ntohl(sin4->sin_addr.s_addr);
828 p = ntohs(sin4->sin_port);
829 e = ftp_cmd(conn, "PORT %d,%d,%d,%d,%d,%d",
830 (a >> 24) & 0xff, (a >> 16) & 0xff,
831 (a >> 8) & 0xff, a & 0xff,
832 (p >> 8) & 0xff, p & 0xff);
833 break;
834 case AF_INET6:
835 #define UC(b) (((int)b)&0xff)
836 e = -1;
837 sin6 = (struct sockaddr_in6 *)&sa;
838 sin6->sin6_scope_id = 0;
839 if (getnameinfo((struct sockaddr *)&sa, l,
840 hname, sizeof(hname),
841 NULL, 0, NI_NUMERICHOST) == 0) {
842 e = ftp_cmd(conn, "EPRT |%d|%s|%d|", 2, hname,
843 htons(sin6->sin6_port));
844 if (e == -1)
845 goto ouch;
846 }
847 if (e != FTP_OK) {
848 ap = (char *)&sin6->sin6_addr;
849 e = ftp_cmd(conn,
850 "LPRT %d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d",
851 6, 16,
852 UC(ap[0]), UC(ap[1]), UC(ap[2]), UC(ap[3]),
853 UC(ap[4]), UC(ap[5]), UC(ap[6]), UC(ap[7]),
854 UC(ap[8]), UC(ap[9]), UC(ap[10]), UC(ap[11]),
855 UC(ap[12]), UC(ap[13]), UC(ap[14]), UC(ap[15]),
856 2,
857 (ntohs(sin6->sin6_port) >> 8) & 0xff,
858 ntohs(sin6->sin6_port) & 0xff);
859 }
860 break;
861 default:
862 e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
863 goto ouch;
864 }
865 if (e != FTP_OK)
866 goto ouch;
867
868 /* seek to required offset */
869 if (offset)
870 if (ftp_cmd(conn, "REST %ju", (uintmax_t)offset) != FTP_FILE_OK)
871 goto sysouch;
872
873 /* make the server initiate the transfer */
874 if (verbose)
875 fetch_info("initiating transfer");
876 e = ftp_cmd(conn, "%s %.*s", oper, filenamelen, filename);
877 if (e != FTP_CONNECTION_ALREADY_OPEN && e != FTP_OPEN_DATA_CONNECTION)
878 goto ouch;
879
880 /* accept the incoming connection and go to town */
881 if ((d = accept(sd, NULL, NULL)) == -1)
882 goto sysouch;
883 close(sd);
884 sd = d;
885 }
886
887 if ((df = ftp_setup(conn, fetch_reopen(sd), mode)) == NULL)
888 goto sysouch;
889 return (df);
890
891 sysouch:
892 fetch_syserr();
893 if (sd >= 0)
894 close(sd);
895 return (NULL);
896
897 ouch:
898 if (e != -1)
899 ftp_seterr(e);
900 if (sd >= 0)
901 close(sd);
902 return (NULL);
903 }
904
905 /*
906 * Authenticate
907 */
908 static int
ftp_authenticate(conn_t * conn,struct url * url,struct url * purl)909 ftp_authenticate(conn_t *conn, struct url *url, struct url *purl)
910 {
911 const char *user, *pwd, *logname;
912 char pbuf[MAXHOSTNAMELEN + MAXLOGNAME + 1];
913 int e, len;
914
915 /* XXX FTP_AUTH, and maybe .netrc */
916
917 /* send user name and password */
918 if (url->user[0] == '\0')
919 fetch_netrc_auth(url);
920 user = url->user;
921 if (*user == '\0')
922 if ((user = getenv("FTP_LOGIN")) != NULL)
923 DEBUGF("FTP_LOGIN=%s\n", user);
924 if (user == NULL || *user == '\0')
925 user = FTP_ANONYMOUS_USER;
926 if (purl && url->port == fetch_default_port(url->scheme))
927 e = ftp_cmd(conn, "USER %s@%s", user, url->host);
928 else if (purl)
929 e = ftp_cmd(conn, "USER %s@%s@%d", user, url->host, url->port);
930 else
931 e = ftp_cmd(conn, "USER %s", user);
932
933 /* did the server request a password? */
934 if (e == FTP_NEED_PASSWORD) {
935 pwd = url->pwd;
936 if (*pwd == '\0')
937 if ((pwd = getenv("FTP_PASSWORD")) != NULL)
938 DEBUGF("FTP_PASSWORD=%s\n", pwd);
939 if (pwd == NULL || *pwd == '\0') {
940 if ((logname = getlogin()) == NULL)
941 logname = FTP_ANONYMOUS_USER;
942 if ((len = snprintf(pbuf, MAXLOGNAME + 1, "%s@", logname)) < 0)
943 len = 0;
944 else if (len > MAXLOGNAME)
945 len = MAXLOGNAME;
946 gethostname(pbuf + len, sizeof(pbuf) - len);
947 pwd = pbuf;
948 }
949 e = ftp_cmd(conn, "PASS %s", pwd);
950 }
951
952 return (e);
953 }
954
955 /*
956 * Log on to FTP server
957 */
958 static conn_t *
ftp_connect(struct url * url,struct url * purl,const char * flags)959 ftp_connect(struct url *url, struct url *purl, const char *flags)
960 {
961 conn_t *conn;
962 int e, direct, verbose;
963 #ifdef INET6
964 int af = AF_UNSPEC;
965 #else
966 int af = AF_INET;
967 #endif
968
969 direct = CHECK_FLAG('d');
970 verbose = CHECK_FLAG('v');
971 if (CHECK_FLAG('4'))
972 af = AF_INET;
973 else if (CHECK_FLAG('6'))
974 af = AF_INET6;
975
976 if (direct)
977 purl = NULL;
978
979 /* check for proxy */
980 if (purl) {
981 /* XXX proxy authentication! */
982 conn = fetch_connect(purl, af, verbose);
983 } else {
984 /* no proxy, go straight to target */
985 conn = fetch_connect(url, af, verbose);
986 purl = NULL;
987 }
988
989 /* check connection */
990 if (conn == NULL)
991 /* fetch_connect() has already set an error code */
992 return (NULL);
993
994 /* expect welcome message */
995 if ((e = ftp_chkerr(conn)) != FTP_SERVICE_READY)
996 goto fouch;
997
998 /* authenticate */
999 if ((e = ftp_authenticate(conn, url, purl)) != FTP_LOGGED_IN)
1000 goto fouch;
1001
1002 /* TODO: Request extended features supported, if any (RFC 3659). */
1003
1004 /* done */
1005 return (conn);
1006
1007 fouch:
1008 if (e != -1)
1009 ftp_seterr(e);
1010 fetch_close(conn);
1011 return (NULL);
1012 }
1013
1014 /*
1015 * Disconnect from server
1016 */
1017 static void
ftp_disconnect(conn_t * conn)1018 ftp_disconnect(conn_t *conn)
1019 {
1020 (void)ftp_cmd(conn, "QUIT");
1021 if (conn == cached_connection && conn->ref == 1)
1022 cached_connection = NULL;
1023 fetch_close(conn);
1024 }
1025
1026 /*
1027 * Check if we're already connected
1028 */
1029 static int
ftp_isconnected(struct url * url)1030 ftp_isconnected(struct url *url)
1031 {
1032 return (cached_connection
1033 && (strcmp(url->host, cached_host.host) == 0)
1034 && (strcmp(url->user, cached_host.user) == 0)
1035 && (strcmp(url->pwd, cached_host.pwd) == 0)
1036 && (url->port == cached_host.port));
1037 }
1038
1039 /*
1040 * Check the cache, reconnect if no luck
1041 */
1042 static conn_t *
ftp_cached_connect(struct url * url,struct url * purl,const char * flags)1043 ftp_cached_connect(struct url *url, struct url *purl, const char *flags)
1044 {
1045 conn_t *conn;
1046 int e;
1047
1048 /* set default port */
1049 if (!url->port)
1050 url->port = fetch_default_port(url->scheme);
1051
1052 /* try to use previously cached connection */
1053 if (ftp_isconnected(url)) {
1054 e = ftp_cmd(cached_connection, "NOOP");
1055 if (e == FTP_OK || e == FTP_SYNTAX_ERROR)
1056 return (fetch_ref(cached_connection));
1057 }
1058
1059 /* connect to server */
1060 if ((conn = ftp_connect(url, purl, flags)) == NULL)
1061 return (NULL);
1062 if (cached_connection)
1063 ftp_disconnect(cached_connection);
1064 cached_connection = fetch_ref(conn);
1065 memcpy(&cached_host, url, sizeof(*url));
1066 return (conn);
1067 }
1068
1069 /*
1070 * Check the proxy settings
1071 */
1072 static struct url *
ftp_get_proxy(struct url * url,const char * flags)1073 ftp_get_proxy(struct url * url, const char *flags)
1074 {
1075 struct url *purl;
1076 char *p;
1077
1078 if (flags != NULL && strchr(flags, 'd') != NULL)
1079 return (NULL);
1080 if (fetch_no_proxy_match(url->host))
1081 return (NULL);
1082 if (((p = getenv("FTP_PROXY")) || (p = getenv("ftp_proxy")) ||
1083 (p = getenv("HTTP_PROXY")) || (p = getenv("http_proxy"))) &&
1084 *p && (purl = fetchParseURL(p)) != NULL) {
1085 if (!*purl->scheme) {
1086 if (getenv("FTP_PROXY") || getenv("ftp_proxy"))
1087 strcpy(purl->scheme, SCHEME_FTP);
1088 else
1089 strcpy(purl->scheme, SCHEME_HTTP);
1090 }
1091 if (!purl->port)
1092 purl->port = fetch_default_proxy_port(purl->scheme);
1093 if (strcmp(purl->scheme, SCHEME_FTP) == 0 ||
1094 strcmp(purl->scheme, SCHEME_HTTP) == 0)
1095 return (purl);
1096 fetchFreeURL(purl);
1097 }
1098 return (NULL);
1099 }
1100
1101 /*
1102 * Process an FTP request
1103 */
1104 FILE *
ftp_request(struct url * url,const char * op,struct url_stat * us,struct url * purl,const char * flags)1105 ftp_request(struct url *url, const char *op, struct url_stat *us,
1106 struct url *purl, const char *flags)
1107 {
1108 conn_t *conn;
1109 int oflag;
1110
1111 /* check if we should use HTTP instead */
1112 if (purl && (strcmp(purl->scheme, SCHEME_HTTP) == 0 ||
1113 strcmp(purl->scheme, SCHEME_HTTPS) == 0)) {
1114 if (strcmp(op, "STAT") == 0)
1115 return (http_request(url, "HEAD", us, purl, flags));
1116 else if (strcmp(op, "RETR") == 0)
1117 return (http_request(url, "GET", us, purl, flags));
1118 /*
1119 * Our HTTP code doesn't support PUT requests yet, so try
1120 * a direct connection.
1121 */
1122 }
1123
1124 /* connect to server */
1125 conn = ftp_cached_connect(url, purl, flags);
1126 if (purl)
1127 fetchFreeURL(purl);
1128 if (conn == NULL)
1129 return (NULL);
1130
1131 /* change directory */
1132 if (ftp_cwd(conn, url->doc) == -1)
1133 goto errsock;
1134
1135 /* stat file */
1136 if (us && ftp_stat(conn, url->doc, us) == -1
1137 && fetchLastErrCode != FETCH_PROTO
1138 && fetchLastErrCode != FETCH_UNAVAIL)
1139 goto errsock;
1140
1141 /* just a stat */
1142 if (strcmp(op, "STAT") == 0) {
1143 --conn->ref;
1144 ftp_disconnect(conn);
1145 return (FILE *)1; /* bogus return value */
1146 }
1147 if (strcmp(op, "STOR") == 0 || strcmp(op, "APPE") == 0)
1148 oflag = O_WRONLY;
1149 else
1150 oflag = O_RDONLY;
1151
1152 /* initiate the transfer */
1153 return (ftp_transfer(conn, op, url->doc, oflag, url->offset, flags));
1154
1155 errsock:
1156 ftp_disconnect(conn);
1157 return (NULL);
1158 }
1159
1160 /*
1161 * Get and stat file
1162 */
1163 FILE *
fetchXGetFTP(struct url * url,struct url_stat * us,const char * flags)1164 fetchXGetFTP(struct url *url, struct url_stat *us, const char *flags)
1165 {
1166 return (ftp_request(url, "RETR", us, ftp_get_proxy(url, flags), flags));
1167 }
1168
1169 /*
1170 * Get file
1171 */
1172 FILE *
fetchGetFTP(struct url * url,const char * flags)1173 fetchGetFTP(struct url *url, const char *flags)
1174 {
1175 return (fetchXGetFTP(url, NULL, flags));
1176 }
1177
1178 /*
1179 * Put file
1180 */
1181 FILE *
fetchPutFTP(struct url * url,const char * flags)1182 fetchPutFTP(struct url *url, const char *flags)
1183 {
1184 return (ftp_request(url, CHECK_FLAG('a') ? "APPE" : "STOR", NULL,
1185 ftp_get_proxy(url, flags), flags));
1186 }
1187
1188 /*
1189 * Get file stats
1190 */
1191 int
fetchStatFTP(struct url * url,struct url_stat * us,const char * flags)1192 fetchStatFTP(struct url *url, struct url_stat *us, const char *flags)
1193 {
1194 FILE *f;
1195
1196 f = ftp_request(url, "STAT", us, ftp_get_proxy(url, flags), flags);
1197 if (f == NULL)
1198 return (-1);
1199 /*
1200 * When op is "STAT", ftp_request() will return either NULL or
1201 * (FILE *)1, never a valid FILE *, so we mustn't fclose(f) before
1202 * returning, as it would cause a segfault.
1203 */
1204 return (0);
1205 }
1206
1207 /*
1208 * List a directory
1209 */
1210 struct url_ent *
fetchListFTP(struct url * url __unused,const char * flags __unused)1211 fetchListFTP(struct url *url __unused, const char *flags __unused)
1212 {
1213 warnx("fetchListFTP(): not implemented");
1214 return (NULL);
1215 }
1216