xref: /freebsd/crypto/openssh/sftp-client.c (revision ee2ea5ceafed78a5bd9810beb9e3ca927180c226)
1 /*
2  * Copyright (c) 2001,2002 Damien Miller.  All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23  */
24 
25 /* XXX: memleaks */
26 /* XXX: signed vs unsigned */
27 /* XXX: remove all logging, only return status codes */
28 /* XXX: copy between two remote sites */
29 
30 #include "includes.h"
31 RCSID("$OpenBSD: sftp-client.c,v 1.24 2002/02/24 16:57:19 markus Exp $");
32 
33 #include <sys/queue.h>
34 
35 #include "buffer.h"
36 #include "bufaux.h"
37 #include "getput.h"
38 #include "xmalloc.h"
39 #include "log.h"
40 #include "atomicio.h"
41 
42 #include "sftp.h"
43 #include "sftp-common.h"
44 #include "sftp-client.h"
45 
46 /* Minimum amount of data to read at at time */
47 #define MIN_READ_SIZE	512
48 
49 struct sftp_conn {
50 	int fd_in;
51 	int fd_out;
52 	u_int transfer_buflen;
53 	u_int num_requests;
54 	u_int version;
55 	u_int msg_id;
56 };
57 
58 static void
59 send_msg(int fd, Buffer *m)
60 {
61 	int mlen = buffer_len(m);
62 	int len;
63 	Buffer oqueue;
64 
65 	buffer_init(&oqueue);
66 	buffer_put_int(&oqueue, mlen);
67 	buffer_append(&oqueue, buffer_ptr(m), mlen);
68 	buffer_consume(m, mlen);
69 
70 	len = atomicio(write, fd, buffer_ptr(&oqueue), buffer_len(&oqueue));
71 	if (len <= 0)
72 		fatal("Couldn't send packet: %s", strerror(errno));
73 
74 	buffer_free(&oqueue);
75 }
76 
77 static void
78 get_msg(int fd, Buffer *m)
79 {
80 	u_int len, msg_len;
81 	unsigned char buf[4096];
82 
83 	len = atomicio(read, fd, buf, 4);
84 	if (len == 0)
85 		fatal("Connection closed");
86 	else if (len == -1)
87 		fatal("Couldn't read packet: %s", strerror(errno));
88 
89 	msg_len = GET_32BIT(buf);
90 	if (msg_len > 256 * 1024)
91 		fatal("Received message too long %d", msg_len);
92 
93 	while (msg_len) {
94 		len = atomicio(read, fd, buf, MIN(msg_len, sizeof(buf)));
95 		if (len == 0)
96 			fatal("Connection closed");
97 		else if (len == -1)
98 			fatal("Couldn't read packet: %s", strerror(errno));
99 
100 		msg_len -= len;
101 		buffer_append(m, buf, len);
102 	}
103 }
104 
105 static void
106 send_string_request(int fd, u_int id, u_int code, char *s,
107     u_int len)
108 {
109 	Buffer msg;
110 
111 	buffer_init(&msg);
112 	buffer_put_char(&msg, code);
113 	buffer_put_int(&msg, id);
114 	buffer_put_string(&msg, s, len);
115 	send_msg(fd, &msg);
116 	debug3("Sent message fd %d T:%d I:%d", fd, code, id);
117 	buffer_free(&msg);
118 }
119 
120 static void
121 send_string_attrs_request(int fd, u_int id, u_int code, char *s,
122     u_int len, Attrib *a)
123 {
124 	Buffer msg;
125 
126 	buffer_init(&msg);
127 	buffer_put_char(&msg, code);
128 	buffer_put_int(&msg, id);
129 	buffer_put_string(&msg, s, len);
130 	encode_attrib(&msg, a);
131 	send_msg(fd, &msg);
132 	debug3("Sent message fd %d T:%d I:%d", fd, code, id);
133 	buffer_free(&msg);
134 }
135 
136 static u_int
137 get_status(int fd, int expected_id)
138 {
139 	Buffer msg;
140 	u_int type, id, status;
141 
142 	buffer_init(&msg);
143 	get_msg(fd, &msg);
144 	type = buffer_get_char(&msg);
145 	id = buffer_get_int(&msg);
146 
147 	if (id != expected_id)
148 		fatal("ID mismatch (%d != %d)", id, expected_id);
149 	if (type != SSH2_FXP_STATUS)
150 		fatal("Expected SSH2_FXP_STATUS(%d) packet, got %d",
151 		    SSH2_FXP_STATUS, type);
152 
153 	status = buffer_get_int(&msg);
154 	buffer_free(&msg);
155 
156 	debug3("SSH2_FXP_STATUS %d", status);
157 
158 	return(status);
159 }
160 
161 static char *
162 get_handle(int fd, u_int expected_id, u_int *len)
163 {
164 	Buffer msg;
165 	u_int type, id;
166 	char *handle;
167 
168 	buffer_init(&msg);
169 	get_msg(fd, &msg);
170 	type = buffer_get_char(&msg);
171 	id = buffer_get_int(&msg);
172 
173 	if (id != expected_id)
174 		fatal("ID mismatch (%d != %d)", id, expected_id);
175 	if (type == SSH2_FXP_STATUS) {
176 		int status = buffer_get_int(&msg);
177 
178 		error("Couldn't get handle: %s", fx2txt(status));
179 		return(NULL);
180 	} else if (type != SSH2_FXP_HANDLE)
181 		fatal("Expected SSH2_FXP_HANDLE(%d) packet, got %d",
182 		    SSH2_FXP_HANDLE, type);
183 
184 	handle = buffer_get_string(&msg, len);
185 	buffer_free(&msg);
186 
187 	return(handle);
188 }
189 
190 static Attrib *
191 get_decode_stat(int fd, u_int expected_id, int quiet)
192 {
193 	Buffer msg;
194 	u_int type, id;
195 	Attrib *a;
196 
197 	buffer_init(&msg);
198 	get_msg(fd, &msg);
199 
200 	type = buffer_get_char(&msg);
201 	id = buffer_get_int(&msg);
202 
203 	debug3("Received stat reply T:%d I:%d", type, id);
204 	if (id != expected_id)
205 		fatal("ID mismatch (%d != %d)", id, expected_id);
206 	if (type == SSH2_FXP_STATUS) {
207 		int status = buffer_get_int(&msg);
208 
209 		if (quiet)
210 			debug("Couldn't stat remote file: %s", fx2txt(status));
211 		else
212 			error("Couldn't stat remote file: %s", fx2txt(status));
213 		return(NULL);
214 	} else if (type != SSH2_FXP_ATTRS) {
215 		fatal("Expected SSH2_FXP_ATTRS(%d) packet, got %d",
216 		    SSH2_FXP_ATTRS, type);
217 	}
218 	a = decode_attrib(&msg);
219 	buffer_free(&msg);
220 
221 	return(a);
222 }
223 
224 struct sftp_conn *
225 do_init(int fd_in, int fd_out, u_int transfer_buflen, u_int num_requests)
226 {
227 	int type, version;
228 	Buffer msg;
229 	struct sftp_conn *ret;
230 
231 	buffer_init(&msg);
232 	buffer_put_char(&msg, SSH2_FXP_INIT);
233 	buffer_put_int(&msg, SSH2_FILEXFER_VERSION);
234 	send_msg(fd_out, &msg);
235 
236 	buffer_clear(&msg);
237 
238 	get_msg(fd_in, &msg);
239 
240 	/* Expecting a VERSION reply */
241 	if ((type = buffer_get_char(&msg)) != SSH2_FXP_VERSION) {
242 		error("Invalid packet back from SSH2_FXP_INIT (type %d)",
243 		    type);
244 		buffer_free(&msg);
245 		return(NULL);
246 	}
247 	version = buffer_get_int(&msg);
248 
249 	debug2("Remote version: %d", version);
250 
251 	/* Check for extensions */
252 	while (buffer_len(&msg) > 0) {
253 		char *name = buffer_get_string(&msg, NULL);
254 		char *value = buffer_get_string(&msg, NULL);
255 
256 		debug2("Init extension: \"%s\"", name);
257 		xfree(name);
258 		xfree(value);
259 	}
260 
261 	buffer_free(&msg);
262 
263 	ret = xmalloc(sizeof(*ret));
264 	ret->fd_in = fd_in;
265 	ret->fd_out = fd_out;
266 	ret->transfer_buflen = transfer_buflen;
267 	ret->num_requests = num_requests;
268 	ret->version = version;
269 	ret->msg_id = 1;
270 
271 	/* Some filexfer v.0 servers don't support large packets */
272 	if (version == 0)
273 		ret->transfer_buflen = MAX(ret->transfer_buflen, 20480);
274 
275 	return(ret);
276 }
277 
278 u_int
279 sftp_proto_version(struct sftp_conn *conn)
280 {
281 	return(conn->version);
282 }
283 
284 int
285 do_close(struct sftp_conn *conn, char *handle, u_int handle_len)
286 {
287 	u_int id, status;
288 	Buffer msg;
289 
290 	buffer_init(&msg);
291 
292 	id = conn->msg_id++;
293 	buffer_put_char(&msg, SSH2_FXP_CLOSE);
294 	buffer_put_int(&msg, id);
295 	buffer_put_string(&msg, handle, handle_len);
296 	send_msg(conn->fd_out, &msg);
297 	debug3("Sent message SSH2_FXP_CLOSE I:%d", id);
298 
299 	status = get_status(conn->fd_in, id);
300 	if (status != SSH2_FX_OK)
301 		error("Couldn't close file: %s", fx2txt(status));
302 
303 	buffer_free(&msg);
304 
305 	return(status);
306 }
307 
308 
309 static int
310 do_lsreaddir(struct sftp_conn *conn, char *path, int printflag,
311     SFTP_DIRENT ***dir)
312 {
313 	Buffer msg;
314 	u_int type, id, handle_len, i, expected_id, ents = 0;
315 	char *handle;
316 
317 	id = conn->msg_id++;
318 
319 	buffer_init(&msg);
320 	buffer_put_char(&msg, SSH2_FXP_OPENDIR);
321 	buffer_put_int(&msg, id);
322 	buffer_put_cstring(&msg, path);
323 	send_msg(conn->fd_out, &msg);
324 
325 	buffer_clear(&msg);
326 
327 	handle = get_handle(conn->fd_in, id, &handle_len);
328 	if (handle == NULL)
329 		return(-1);
330 
331 	if (dir) {
332 		ents = 0;
333 		*dir = xmalloc(sizeof(**dir));
334 		(*dir)[0] = NULL;
335 	}
336 
337 	for (;;) {
338 		int count;
339 
340 		id = expected_id = conn->msg_id++;
341 
342 		debug3("Sending SSH2_FXP_READDIR I:%d", id);
343 
344 		buffer_clear(&msg);
345 		buffer_put_char(&msg, SSH2_FXP_READDIR);
346 		buffer_put_int(&msg, id);
347 		buffer_put_string(&msg, handle, handle_len);
348 		send_msg(conn->fd_out, &msg);
349 
350 		buffer_clear(&msg);
351 
352 		get_msg(conn->fd_in, &msg);
353 
354 		type = buffer_get_char(&msg);
355 		id = buffer_get_int(&msg);
356 
357 		debug3("Received reply T:%d I:%d", type, id);
358 
359 		if (id != expected_id)
360 			fatal("ID mismatch (%d != %d)", id, expected_id);
361 
362 		if (type == SSH2_FXP_STATUS) {
363 			int status = buffer_get_int(&msg);
364 
365 			debug3("Received SSH2_FXP_STATUS %d", status);
366 
367 			if (status == SSH2_FX_EOF) {
368 				break;
369 			} else {
370 				error("Couldn't read directory: %s",
371 				    fx2txt(status));
372 				do_close(conn, handle, handle_len);
373 				return(status);
374 			}
375 		} else if (type != SSH2_FXP_NAME)
376 			fatal("Expected SSH2_FXP_NAME(%d) packet, got %d",
377 			    SSH2_FXP_NAME, type);
378 
379 		count = buffer_get_int(&msg);
380 		if (count == 0)
381 			break;
382 		debug3("Received %d SSH2_FXP_NAME responses", count);
383 		for (i = 0; i < count; i++) {
384 			char *filename, *longname;
385 			Attrib *a;
386 
387 			filename = buffer_get_string(&msg, NULL);
388 			longname = buffer_get_string(&msg, NULL);
389 			a = decode_attrib(&msg);
390 
391 			if (printflag)
392 				printf("%s\n", longname);
393 
394 			if (dir) {
395 				*dir = xrealloc(*dir, sizeof(**dir) *
396 				    (ents + 2));
397 				(*dir)[ents] = xmalloc(sizeof(***dir));
398 				(*dir)[ents]->filename = xstrdup(filename);
399 				(*dir)[ents]->longname = xstrdup(longname);
400 				memcpy(&(*dir)[ents]->a, a, sizeof(*a));
401 				(*dir)[++ents] = NULL;
402 			}
403 
404 			xfree(filename);
405 			xfree(longname);
406 		}
407 	}
408 
409 	buffer_free(&msg);
410 	do_close(conn, handle, handle_len);
411 	xfree(handle);
412 
413 	return(0);
414 }
415 
416 int
417 do_ls(struct sftp_conn *conn, char *path)
418 {
419 	return(do_lsreaddir(conn, path, 1, NULL));
420 }
421 
422 int
423 do_readdir(struct sftp_conn *conn, char *path, SFTP_DIRENT ***dir)
424 {
425 	return(do_lsreaddir(conn, path, 0, dir));
426 }
427 
428 void free_sftp_dirents(SFTP_DIRENT **s)
429 {
430 	int i;
431 
432 	for (i = 0; s[i]; i++) {
433 		xfree(s[i]->filename);
434 		xfree(s[i]->longname);
435 		xfree(s[i]);
436 	}
437 	xfree(s);
438 }
439 
440 int
441 do_rm(struct sftp_conn *conn, char *path)
442 {
443 	u_int status, id;
444 
445 	debug2("Sending SSH2_FXP_REMOVE \"%s\"", path);
446 
447 	id = conn->msg_id++;
448 	send_string_request(conn->fd_out, id, SSH2_FXP_REMOVE, path,
449 	    strlen(path));
450 	status = get_status(conn->fd_in, id);
451 	if (status != SSH2_FX_OK)
452 		error("Couldn't delete file: %s", fx2txt(status));
453 	return(status);
454 }
455 
456 int
457 do_mkdir(struct sftp_conn *conn, char *path, Attrib *a)
458 {
459 	u_int status, id;
460 
461 	id = conn->msg_id++;
462 	send_string_attrs_request(conn->fd_out, id, SSH2_FXP_MKDIR, path,
463 	    strlen(path), a);
464 
465 	status = get_status(conn->fd_in, id);
466 	if (status != SSH2_FX_OK)
467 		error("Couldn't create directory: %s", fx2txt(status));
468 
469 	return(status);
470 }
471 
472 int
473 do_rmdir(struct sftp_conn *conn, char *path)
474 {
475 	u_int status, id;
476 
477 	id = conn->msg_id++;
478 	send_string_request(conn->fd_out, id, SSH2_FXP_RMDIR, path,
479 	    strlen(path));
480 
481 	status = get_status(conn->fd_in, id);
482 	if (status != SSH2_FX_OK)
483 		error("Couldn't remove directory: %s", fx2txt(status));
484 
485 	return(status);
486 }
487 
488 Attrib *
489 do_stat(struct sftp_conn *conn, char *path, int quiet)
490 {
491 	u_int id;
492 
493 	id = conn->msg_id++;
494 
495 	send_string_request(conn->fd_out, id,
496 	    conn->version == 0 ? SSH2_FXP_STAT_VERSION_0 : SSH2_FXP_STAT,
497 	    path, strlen(path));
498 
499 	return(get_decode_stat(conn->fd_in, id, quiet));
500 }
501 
502 Attrib *
503 do_lstat(struct sftp_conn *conn, char *path, int quiet)
504 {
505 	u_int id;
506 
507 	if (conn->version == 0) {
508 		if (quiet)
509 			debug("Server version does not support lstat operation");
510 		else
511 			error("Server version does not support lstat operation");
512 		return(NULL);
513 	}
514 
515 	id = conn->msg_id++;
516 	send_string_request(conn->fd_out, id, SSH2_FXP_LSTAT, path,
517 	    strlen(path));
518 
519 	return(get_decode_stat(conn->fd_in, id, quiet));
520 }
521 
522 Attrib *
523 do_fstat(struct sftp_conn *conn, char *handle, u_int handle_len, int quiet)
524 {
525 	u_int id;
526 
527 	id = conn->msg_id++;
528 	send_string_request(conn->fd_out, id, SSH2_FXP_FSTAT, handle,
529 	    handle_len);
530 
531 	return(get_decode_stat(conn->fd_in, id, quiet));
532 }
533 
534 int
535 do_setstat(struct sftp_conn *conn, char *path, Attrib *a)
536 {
537 	u_int status, id;
538 
539 	id = conn->msg_id++;
540 	send_string_attrs_request(conn->fd_out, id, SSH2_FXP_SETSTAT, path,
541 	    strlen(path), a);
542 
543 	status = get_status(conn->fd_in, id);
544 	if (status != SSH2_FX_OK)
545 		error("Couldn't setstat on \"%s\": %s", path,
546 		    fx2txt(status));
547 
548 	return(status);
549 }
550 
551 int
552 do_fsetstat(struct sftp_conn *conn, char *handle, u_int handle_len,
553     Attrib *a)
554 {
555 	u_int status, id;
556 
557 	id = conn->msg_id++;
558 	send_string_attrs_request(conn->fd_out, id, SSH2_FXP_FSETSTAT, handle,
559 	    handle_len, a);
560 
561 	status = get_status(conn->fd_in, id);
562 	if (status != SSH2_FX_OK)
563 		error("Couldn't fsetstat: %s", fx2txt(status));
564 
565 	return(status);
566 }
567 
568 char *
569 do_realpath(struct sftp_conn *conn, char *path)
570 {
571 	Buffer msg;
572 	u_int type, expected_id, count, id;
573 	char *filename, *longname;
574 	Attrib *a;
575 
576 	expected_id = id = conn->msg_id++;
577 	send_string_request(conn->fd_out, id, SSH2_FXP_REALPATH, path,
578 	    strlen(path));
579 
580 	buffer_init(&msg);
581 
582 	get_msg(conn->fd_in, &msg);
583 	type = buffer_get_char(&msg);
584 	id = buffer_get_int(&msg);
585 
586 	if (id != expected_id)
587 		fatal("ID mismatch (%d != %d)", id, expected_id);
588 
589 	if (type == SSH2_FXP_STATUS) {
590 		u_int status = buffer_get_int(&msg);
591 
592 		error("Couldn't canonicalise: %s", fx2txt(status));
593 		return(NULL);
594 	} else if (type != SSH2_FXP_NAME)
595 		fatal("Expected SSH2_FXP_NAME(%d) packet, got %d",
596 		    SSH2_FXP_NAME, type);
597 
598 	count = buffer_get_int(&msg);
599 	if (count != 1)
600 		fatal("Got multiple names (%d) from SSH_FXP_REALPATH", count);
601 
602 	filename = buffer_get_string(&msg, NULL);
603 	longname = buffer_get_string(&msg, NULL);
604 	a = decode_attrib(&msg);
605 
606 	debug3("SSH_FXP_REALPATH %s -> %s", path, filename);
607 
608 	xfree(longname);
609 
610 	buffer_free(&msg);
611 
612 	return(filename);
613 }
614 
615 int
616 do_rename(struct sftp_conn *conn, char *oldpath, char *newpath)
617 {
618 	Buffer msg;
619 	u_int status, id;
620 
621 	buffer_init(&msg);
622 
623 	/* Send rename request */
624 	id = conn->msg_id++;
625 	buffer_put_char(&msg, SSH2_FXP_RENAME);
626 	buffer_put_int(&msg, id);
627 	buffer_put_cstring(&msg, oldpath);
628 	buffer_put_cstring(&msg, newpath);
629 	send_msg(conn->fd_out, &msg);
630 	debug3("Sent message SSH2_FXP_RENAME \"%s\" -> \"%s\"", oldpath,
631 	    newpath);
632 	buffer_free(&msg);
633 
634 	status = get_status(conn->fd_in, id);
635 	if (status != SSH2_FX_OK)
636 		error("Couldn't rename file \"%s\" to \"%s\": %s", oldpath,
637 		    newpath, fx2txt(status));
638 
639 	return(status);
640 }
641 
642 int
643 do_symlink(struct sftp_conn *conn, char *oldpath, char *newpath)
644 {
645 	Buffer msg;
646 	u_int status, id;
647 
648 	if (conn->version < 3) {
649 		error("This server does not support the symlink operation");
650 		return(SSH2_FX_OP_UNSUPPORTED);
651 	}
652 
653 	buffer_init(&msg);
654 
655 	/* Send rename request */
656 	id = conn->msg_id++;
657 	buffer_put_char(&msg, SSH2_FXP_SYMLINK);
658 	buffer_put_int(&msg, id);
659 	buffer_put_cstring(&msg, oldpath);
660 	buffer_put_cstring(&msg, newpath);
661 	send_msg(conn->fd_out, &msg);
662 	debug3("Sent message SSH2_FXP_SYMLINK \"%s\" -> \"%s\"", oldpath,
663 	    newpath);
664 	buffer_free(&msg);
665 
666 	status = get_status(conn->fd_in, id);
667 	if (status != SSH2_FX_OK)
668 		error("Couldn't rename file \"%s\" to \"%s\": %s", oldpath,
669 		    newpath, fx2txt(status));
670 
671 	return(status);
672 }
673 
674 char *
675 do_readlink(struct sftp_conn *conn, char *path)
676 {
677 	Buffer msg;
678 	u_int type, expected_id, count, id;
679 	char *filename, *longname;
680 	Attrib *a;
681 
682 	expected_id = id = conn->msg_id++;
683 	send_string_request(conn->fd_out, id, SSH2_FXP_READLINK, path,
684 	    strlen(path));
685 
686 	buffer_init(&msg);
687 
688 	get_msg(conn->fd_in, &msg);
689 	type = buffer_get_char(&msg);
690 	id = buffer_get_int(&msg);
691 
692 	if (id != expected_id)
693 		fatal("ID mismatch (%d != %d)", id, expected_id);
694 
695 	if (type == SSH2_FXP_STATUS) {
696 		u_int status = buffer_get_int(&msg);
697 
698 		error("Couldn't readlink: %s", fx2txt(status));
699 		return(NULL);
700 	} else if (type != SSH2_FXP_NAME)
701 		fatal("Expected SSH2_FXP_NAME(%d) packet, got %d",
702 		    SSH2_FXP_NAME, type);
703 
704 	count = buffer_get_int(&msg);
705 	if (count != 1)
706 		fatal("Got multiple names (%d) from SSH_FXP_READLINK", count);
707 
708 	filename = buffer_get_string(&msg, NULL);
709 	longname = buffer_get_string(&msg, NULL);
710 	a = decode_attrib(&msg);
711 
712 	debug3("SSH_FXP_READLINK %s -> %s", path, filename);
713 
714 	xfree(longname);
715 
716 	buffer_free(&msg);
717 
718 	return(filename);
719 }
720 
721 static void
722 send_read_request(int fd_out, u_int id, u_int64_t offset, u_int len,
723     char *handle, u_int handle_len)
724 {
725 	Buffer msg;
726 
727 	buffer_init(&msg);
728 	buffer_clear(&msg);
729 	buffer_put_char(&msg, SSH2_FXP_READ);
730 	buffer_put_int(&msg, id);
731 	buffer_put_string(&msg, handle, handle_len);
732 	buffer_put_int64(&msg, offset);
733 	buffer_put_int(&msg, len);
734 	send_msg(fd_out, &msg);
735 	buffer_free(&msg);
736 }
737 
738 int
739 do_download(struct sftp_conn *conn, char *remote_path, char *local_path,
740     int pflag)
741 {
742 	Attrib junk, *a;
743 	Buffer msg;
744 	char *handle;
745 	int local_fd, status, num_req, max_req, write_error;
746 	int read_error, write_errno;
747 	u_int64_t offset, size;
748 	u_int handle_len, mode, type, id, buflen;
749 	struct request {
750 		u_int id;
751 		u_int len;
752 		u_int64_t offset;
753 		TAILQ_ENTRY(request) tq;
754 	};
755 	TAILQ_HEAD(reqhead, request) requests;
756 	struct request *req;
757 
758 	TAILQ_INIT(&requests);
759 
760 	a = do_stat(conn, remote_path, 0);
761 	if (a == NULL)
762 		return(-1);
763 
764 	/* XXX: should we preserve set[ug]id? */
765 	if (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS)
766 		mode = S_IWRITE | (a->perm & 0777);
767 	else
768 		mode = 0666;
769 
770 	if ((a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) &&
771 	    (a->perm & S_IFDIR)) {
772 		error("Cannot download a directory: %s", remote_path);
773 		return(-1);
774 	}
775 
776 	if (a->flags & SSH2_FILEXFER_ATTR_SIZE)
777 		size = a->size;
778 	else
779 		size = 0;
780 
781 	buflen = conn->transfer_buflen;
782 	buffer_init(&msg);
783 
784 	/* Send open request */
785 	id = conn->msg_id++;
786 	buffer_put_char(&msg, SSH2_FXP_OPEN);
787 	buffer_put_int(&msg, id);
788 	buffer_put_cstring(&msg, remote_path);
789 	buffer_put_int(&msg, SSH2_FXF_READ);
790 	attrib_clear(&junk); /* Send empty attributes */
791 	encode_attrib(&msg, &junk);
792 	send_msg(conn->fd_out, &msg);
793 	debug3("Sent message SSH2_FXP_OPEN I:%d P:%s", id, remote_path);
794 
795 	handle = get_handle(conn->fd_in, id, &handle_len);
796 	if (handle == NULL) {
797 		buffer_free(&msg);
798 		return(-1);
799 	}
800 
801 	local_fd = open(local_path, O_WRONLY | O_CREAT | O_TRUNC, mode);
802 	if (local_fd == -1) {
803 		error("Couldn't open local file \"%s\" for writing: %s",
804 		    local_path, strerror(errno));
805 		buffer_free(&msg);
806 		xfree(handle);
807 		return(-1);
808 	}
809 
810 	/* Read from remote and write to local */
811 	write_error = read_error = write_errno = num_req = offset = 0;
812 	max_req = 1;
813 	while (num_req > 0 || max_req > 0) {
814 		char *data;
815 		u_int len;
816 
817 		/* Send some more requests */
818 		while (num_req < max_req) {
819 			debug3("Request range %llu -> %llu (%d/%d)",
820 			    offset, offset + buflen - 1, num_req, max_req);
821 			req = xmalloc(sizeof(*req));
822 			req->id = conn->msg_id++;
823 			req->len = buflen;
824 			req->offset = offset;
825 			offset += buflen;
826 			num_req++;
827 			TAILQ_INSERT_TAIL(&requests, req, tq);
828 			send_read_request(conn->fd_out, req->id, req->offset,
829 			    req->len, handle, handle_len);
830 		}
831 
832 		buffer_clear(&msg);
833 		get_msg(conn->fd_in, &msg);
834 		type = buffer_get_char(&msg);
835 		id = buffer_get_int(&msg);
836 		debug3("Received reply T:%d I:%d R:%d", type, id, max_req);
837 
838 		/* Find the request in our queue */
839 		for(req = TAILQ_FIRST(&requests);
840 		    req != NULL && req->id != id;
841 		    req = TAILQ_NEXT(req, tq))
842 			;
843 		if (req == NULL)
844 			fatal("Unexpected reply %u", id);
845 
846 		switch (type) {
847 		case SSH2_FXP_STATUS:
848 			status = buffer_get_int(&msg);
849 			if (status != SSH2_FX_EOF)
850 				read_error = 1;
851 			max_req = 0;
852 			TAILQ_REMOVE(&requests, req, tq);
853 			xfree(req);
854 			num_req--;
855 			break;
856 		case SSH2_FXP_DATA:
857 			data = buffer_get_string(&msg, &len);
858 			debug3("Received data %llu -> %llu", req->offset,
859 			    req->offset + len - 1);
860 			if (len > req->len)
861 				fatal("Received more data than asked for "
862 				      "%d > %d", len, req->len);
863 			if ((lseek(local_fd, req->offset, SEEK_SET) == -1 ||
864 			     atomicio(write, local_fd, data, len) != len) &&
865 			    !write_error) {
866 				write_errno = errno;
867 				write_error = 1;
868 				max_req = 0;
869 			}
870 			xfree(data);
871 
872 			if (len == req->len) {
873 				TAILQ_REMOVE(&requests, req, tq);
874 				xfree(req);
875 				num_req--;
876 			} else {
877 				/* Resend the request for the missing data */
878 				debug3("Short data block, re-requesting "
879 				    "%llu -> %llu (%2d)", req->offset + len,
880 					req->offset + req->len - 1, num_req);
881 				req->id = conn->msg_id++;
882 				req->len -= len;
883 				req->offset += len;
884 				send_read_request(conn->fd_out, req->id,
885 				    req->offset, req->len, handle, handle_len);
886 				/* Reduce the request size */
887 				if (len < buflen)
888 					buflen = MAX(MIN_READ_SIZE, len);
889 			}
890 			if (max_req > 0) { /* max_req = 0 iff EOF received */
891 				if (size > 0 && offset > size) {
892 					/* Only one request at a time
893 					 * after the expected EOF */
894 					debug3("Finish at %llu (%2d)",
895 					    offset, num_req);
896 					max_req = 1;
897 				}
898 				else if (max_req < conn->num_requests + 1) {
899 					++max_req;
900 				}
901 			}
902 			break;
903 		default:
904 			fatal("Expected SSH2_FXP_DATA(%d) packet, got %d",
905 			    SSH2_FXP_DATA, type);
906 		}
907 	}
908 
909 	/* Sanity check */
910 	if (TAILQ_FIRST(&requests) != NULL)
911 		fatal("Transfer complete, but requests still in queue");
912 
913 	if (read_error) {
914 		error("Couldn't read from remote file \"%s\" : %s",
915 		    remote_path, fx2txt(status));
916 		do_close(conn, handle, handle_len);
917 	} else if (write_error) {
918 		error("Couldn't write to \"%s\": %s", local_path,
919 		    strerror(write_errno));
920 		status = -1;
921 		do_close(conn, handle, handle_len);
922 	} else {
923 		status = do_close(conn, handle, handle_len);
924 
925 		/* Override umask and utimes if asked */
926 		if (pflag && fchmod(local_fd, mode) == -1)
927 			error("Couldn't set mode on \"%s\": %s", local_path,
928 			      strerror(errno));
929 		if (pflag && (a->flags & SSH2_FILEXFER_ATTR_ACMODTIME)) {
930 			struct timeval tv[2];
931 			tv[0].tv_sec = a->atime;
932 			tv[1].tv_sec = a->mtime;
933 			tv[0].tv_usec = tv[1].tv_usec = 0;
934 			if (utimes(local_path, tv) == -1)
935 				error("Can't set times on \"%s\": %s",
936 				      local_path, strerror(errno));
937 		}
938 	}
939 	close(local_fd);
940 	buffer_free(&msg);
941 	xfree(handle);
942 
943 	return(status);
944 }
945 
946 int
947 do_upload(struct sftp_conn *conn, char *local_path, char *remote_path,
948     int pflag)
949 {
950 	int local_fd, status;
951 	u_int handle_len, id, type;
952 	u_int64_t offset;
953 	char *handle, *data;
954 	Buffer msg;
955 	struct stat sb;
956 	Attrib a;
957 	u_int32_t startid;
958 	u_int32_t ackid;
959 	struct outstanding_ack {
960 		u_int id;
961 		u_int len;
962 		u_int64_t offset;
963 		TAILQ_ENTRY(outstanding_ack) tq;
964 	};
965 	TAILQ_HEAD(ackhead, outstanding_ack) acks;
966 	struct outstanding_ack *ack;
967 
968 	TAILQ_INIT(&acks);
969 
970 	if ((local_fd = open(local_path, O_RDONLY, 0)) == -1) {
971 		error("Couldn't open local file \"%s\" for reading: %s",
972 		    local_path, strerror(errno));
973 		return(-1);
974 	}
975 	if (fstat(local_fd, &sb) == -1) {
976 		error("Couldn't fstat local file \"%s\": %s",
977 		    local_path, strerror(errno));
978 		close(local_fd);
979 		return(-1);
980 	}
981 	stat_to_attrib(&sb, &a);
982 
983 	a.flags &= ~SSH2_FILEXFER_ATTR_SIZE;
984 	a.flags &= ~SSH2_FILEXFER_ATTR_UIDGID;
985 	a.perm &= 0777;
986 	if (!pflag)
987 		a.flags &= ~SSH2_FILEXFER_ATTR_ACMODTIME;
988 
989 	buffer_init(&msg);
990 
991 	/* Send open request */
992 	id = conn->msg_id++;
993 	buffer_put_char(&msg, SSH2_FXP_OPEN);
994 	buffer_put_int(&msg, id);
995 	buffer_put_cstring(&msg, remote_path);
996 	buffer_put_int(&msg, SSH2_FXF_WRITE|SSH2_FXF_CREAT|SSH2_FXF_TRUNC);
997 	encode_attrib(&msg, &a);
998 	send_msg(conn->fd_out, &msg);
999 	debug3("Sent message SSH2_FXP_OPEN I:%d P:%s", id, remote_path);
1000 
1001 	buffer_clear(&msg);
1002 
1003 	handle = get_handle(conn->fd_in, id, &handle_len);
1004 	if (handle == NULL) {
1005 		close(local_fd);
1006 		buffer_free(&msg);
1007 		return(-1);
1008 	}
1009 
1010 	startid = ackid = id + 1;
1011 	data = xmalloc(conn->transfer_buflen);
1012 
1013 	/* Read from local and write to remote */
1014 	offset = 0;
1015 	for (;;) {
1016 		int len;
1017 
1018 		/*
1019 		 * Can't use atomicio here because it returns 0 on EOF, thus losing
1020 		 * the last block of the file
1021 		 */
1022 		do
1023 			len = read(local_fd, data, conn->transfer_buflen);
1024 		while ((len == -1) && (errno == EINTR || errno == EAGAIN));
1025 
1026 		if (len == -1)
1027 			fatal("Couldn't read from \"%s\": %s", local_path,
1028 			    strerror(errno));
1029 
1030 		if (len != 0) {
1031 			ack = xmalloc(sizeof(*ack));
1032 			ack->id = ++id;
1033 			ack->offset = offset;
1034 			ack->len = len;
1035 			TAILQ_INSERT_TAIL(&acks, ack, tq);
1036 
1037 			buffer_clear(&msg);
1038 			buffer_put_char(&msg, SSH2_FXP_WRITE);
1039 			buffer_put_int(&msg, ack->id);
1040 			buffer_put_string(&msg, handle, handle_len);
1041 			buffer_put_int64(&msg, offset);
1042 			buffer_put_string(&msg, data, len);
1043 			send_msg(conn->fd_out, &msg);
1044 			debug3("Sent message SSH2_FXP_WRITE I:%d O:%llu S:%u",
1045 			       id, (u_int64_t)offset, len);
1046 		} else if (TAILQ_FIRST(&acks) == NULL)
1047 			break;
1048 
1049 		if (ack == NULL)
1050 			fatal("Unexpected ACK %u", id);
1051 
1052 		if (id == startid || len == 0 ||
1053 		    id - ackid >= conn->num_requests) {
1054 			buffer_clear(&msg);
1055 			get_msg(conn->fd_in, &msg);
1056 			type = buffer_get_char(&msg);
1057 			id = buffer_get_int(&msg);
1058 
1059 			if (type != SSH2_FXP_STATUS)
1060 				fatal("Expected SSH2_FXP_STATUS(%d) packet, "
1061 				    "got %d", SSH2_FXP_STATUS, type);
1062 
1063 			status = buffer_get_int(&msg);
1064 			debug3("SSH2_FXP_STATUS %d", status);
1065 
1066 			/* Find the request in our queue */
1067 			for(ack = TAILQ_FIRST(&acks);
1068 			    ack != NULL && ack->id != id;
1069 			    ack = TAILQ_NEXT(ack, tq))
1070 				;
1071 			if (ack == NULL)
1072 				fatal("Can't find request for ID %d", id);
1073 			TAILQ_REMOVE(&acks, ack, tq);
1074 
1075 			if (status != SSH2_FX_OK) {
1076 				error("Couldn't write to remote file \"%s\": %s",
1077 				      remote_path, fx2txt(status));
1078 				do_close(conn, handle, handle_len);
1079 				close(local_fd);
1080 				goto done;
1081 			}
1082 			debug3("In write loop, ack for %u %d bytes at %llu",
1083 			   ack->id, ack->len, ack->offset);
1084 			++ackid;
1085 			free(ack);
1086 		}
1087 		offset += len;
1088 	}
1089 	xfree(data);
1090 
1091 	if (close(local_fd) == -1) {
1092 		error("Couldn't close local file \"%s\": %s", local_path,
1093 		    strerror(errno));
1094 		do_close(conn, handle, handle_len);
1095 		status = -1;
1096 		goto done;
1097 	}
1098 
1099 	/* Override umask and utimes if asked */
1100 	if (pflag)
1101 		do_fsetstat(conn, handle, handle_len, &a);
1102 
1103 	status = do_close(conn, handle, handle_len);
1104 
1105 done:
1106 	xfree(handle);
1107 	buffer_free(&msg);
1108 	return(status);
1109 }
1110