1 /* $OpenBSD: sftp-server.c,v 1.110 2016/09/12 01:22:38 deraadt Exp $ */
2 /*
3 * Copyright (c) 2000-2004 Markus Friedl. All rights reserved.
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 #include "includes.h"
19
20 #include <sys/types.h>
21 #include <sys/stat.h>
22 #ifdef HAVE_SYS_TIME_H
23 # include <sys/time.h>
24 #endif
25 #ifdef HAVE_SYS_MOUNT_H
26 #include <sys/mount.h>
27 #endif
28 #ifdef HAVE_SYS_STATVFS_H
29 #include <sys/statvfs.h>
30 #endif
31
32 #include <dirent.h>
33 #include <errno.h>
34 #include <fcntl.h>
35 #include <pwd.h>
36 #include <stdlib.h>
37 #include <stdio.h>
38 #include <string.h>
39 #include <time.h>
40 #include <unistd.h>
41 #include <stdarg.h>
42
43 #include "xmalloc.h"
44 #include "sshbuf.h"
45 #include "ssherr.h"
46 #include "log.h"
47 #include "misc.h"
48 #include "match.h"
49 #include "uidswap.h"
50
51 #include "sftp.h"
52 #include "sftp-common.h"
53
54 /* Our verbosity */
55 static LogLevel log_level = SYSLOG_LEVEL_ERROR;
56
57 /* Our client */
58 static struct passwd *pw = NULL;
59 static char *client_addr = NULL;
60
61 /* input and output queue */
62 struct sshbuf *iqueue;
63 struct sshbuf *oqueue;
64
65 /* Version of client */
66 static u_int version;
67
68 /* SSH2_FXP_INIT received */
69 static int init_done;
70
71 /* Disable writes */
72 static int readonly;
73
74 /* Requests that are allowed/denied */
75 static char *request_whitelist, *request_blacklist;
76
77 /* portable attributes, etc. */
78 typedef struct Stat Stat;
79
80 struct Stat {
81 char *name;
82 char *long_name;
83 Attrib attrib;
84 };
85
86 /* Packet handlers */
87 static void process_open(u_int32_t id);
88 static void process_close(u_int32_t id);
89 static void process_read(u_int32_t id);
90 static void process_write(u_int32_t id);
91 static void process_stat(u_int32_t id);
92 static void process_lstat(u_int32_t id);
93 static void process_fstat(u_int32_t id);
94 static void process_setstat(u_int32_t id);
95 static void process_fsetstat(u_int32_t id);
96 static void process_opendir(u_int32_t id);
97 static void process_readdir(u_int32_t id);
98 static void process_remove(u_int32_t id);
99 static void process_mkdir(u_int32_t id);
100 static void process_rmdir(u_int32_t id);
101 static void process_realpath(u_int32_t id);
102 static void process_rename(u_int32_t id);
103 static void process_readlink(u_int32_t id);
104 static void process_symlink(u_int32_t id);
105 static void process_extended_posix_rename(u_int32_t id);
106 static void process_extended_statvfs(u_int32_t id);
107 static void process_extended_fstatvfs(u_int32_t id);
108 static void process_extended_hardlink(u_int32_t id);
109 static void process_extended_fsync(u_int32_t id);
110 static void process_extended(u_int32_t id);
111
112 struct sftp_handler {
113 const char *name; /* user-visible name for fine-grained perms */
114 const char *ext_name; /* extended request name */
115 u_int type; /* packet type, for non extended packets */
116 void (*handler)(u_int32_t);
117 int does_write; /* if nonzero, banned for readonly mode */
118 };
119
120 struct sftp_handler handlers[] = {
121 /* NB. SSH2_FXP_OPEN does the readonly check in the handler itself */
122 { "open", NULL, SSH2_FXP_OPEN, process_open, 0 },
123 { "close", NULL, SSH2_FXP_CLOSE, process_close, 0 },
124 { "read", NULL, SSH2_FXP_READ, process_read, 0 },
125 { "write", NULL, SSH2_FXP_WRITE, process_write, 1 },
126 { "lstat", NULL, SSH2_FXP_LSTAT, process_lstat, 0 },
127 { "fstat", NULL, SSH2_FXP_FSTAT, process_fstat, 0 },
128 { "setstat", NULL, SSH2_FXP_SETSTAT, process_setstat, 1 },
129 { "fsetstat", NULL, SSH2_FXP_FSETSTAT, process_fsetstat, 1 },
130 { "opendir", NULL, SSH2_FXP_OPENDIR, process_opendir, 0 },
131 { "readdir", NULL, SSH2_FXP_READDIR, process_readdir, 0 },
132 { "remove", NULL, SSH2_FXP_REMOVE, process_remove, 1 },
133 { "mkdir", NULL, SSH2_FXP_MKDIR, process_mkdir, 1 },
134 { "rmdir", NULL, SSH2_FXP_RMDIR, process_rmdir, 1 },
135 { "realpath", NULL, SSH2_FXP_REALPATH, process_realpath, 0 },
136 { "stat", NULL, SSH2_FXP_STAT, process_stat, 0 },
137 { "rename", NULL, SSH2_FXP_RENAME, process_rename, 1 },
138 { "readlink", NULL, SSH2_FXP_READLINK, process_readlink, 0 },
139 { "symlink", NULL, SSH2_FXP_SYMLINK, process_symlink, 1 },
140 { NULL, NULL, 0, NULL, 0 }
141 };
142
143 /* SSH2_FXP_EXTENDED submessages */
144 struct sftp_handler extended_handlers[] = {
145 { "posix-rename", "posix-rename@openssh.com", 0,
146 process_extended_posix_rename, 1 },
147 { "statvfs", "statvfs@openssh.com", 0, process_extended_statvfs, 0 },
148 { "fstatvfs", "fstatvfs@openssh.com", 0, process_extended_fstatvfs, 0 },
149 { "hardlink", "hardlink@openssh.com", 0, process_extended_hardlink, 1 },
150 { "fsync", "fsync@openssh.com", 0, process_extended_fsync, 1 },
151 { NULL, NULL, 0, NULL, 0 }
152 };
153
154 static int
request_permitted(struct sftp_handler * h)155 request_permitted(struct sftp_handler *h)
156 {
157 char *result;
158
159 if (readonly && h->does_write) {
160 verbose("Refusing %s request in read-only mode", h->name);
161 return 0;
162 }
163 if (request_blacklist != NULL &&
164 ((result = match_list(h->name, request_blacklist, NULL))) != NULL) {
165 free(result);
166 verbose("Refusing blacklisted %s request", h->name);
167 return 0;
168 }
169 if (request_whitelist != NULL &&
170 ((result = match_list(h->name, request_whitelist, NULL))) != NULL) {
171 free(result);
172 debug2("Permitting whitelisted %s request", h->name);
173 return 1;
174 }
175 if (request_whitelist != NULL) {
176 verbose("Refusing non-whitelisted %s request", h->name);
177 return 0;
178 }
179 return 1;
180 }
181
182 static int
errno_to_portable(int unixerrno)183 errno_to_portable(int unixerrno)
184 {
185 int ret = 0;
186
187 switch (unixerrno) {
188 case 0:
189 ret = SSH2_FX_OK;
190 break;
191 case ENOENT:
192 case ENOTDIR:
193 case EBADF:
194 case ELOOP:
195 ret = SSH2_FX_NO_SUCH_FILE;
196 break;
197 case EPERM:
198 case EACCES:
199 case EFAULT:
200 ret = SSH2_FX_PERMISSION_DENIED;
201 break;
202 case ENAMETOOLONG:
203 case EINVAL:
204 ret = SSH2_FX_BAD_MESSAGE;
205 break;
206 case ENOSYS:
207 ret = SSH2_FX_OP_UNSUPPORTED;
208 break;
209 default:
210 ret = SSH2_FX_FAILURE;
211 break;
212 }
213 return ret;
214 }
215
216 static int
flags_from_portable(int pflags)217 flags_from_portable(int pflags)
218 {
219 int flags = 0;
220
221 if ((pflags & SSH2_FXF_READ) &&
222 (pflags & SSH2_FXF_WRITE)) {
223 flags = O_RDWR;
224 } else if (pflags & SSH2_FXF_READ) {
225 flags = O_RDONLY;
226 } else if (pflags & SSH2_FXF_WRITE) {
227 flags = O_WRONLY;
228 }
229 if (pflags & SSH2_FXF_APPEND)
230 flags |= O_APPEND;
231 if (pflags & SSH2_FXF_CREAT)
232 flags |= O_CREAT;
233 if (pflags & SSH2_FXF_TRUNC)
234 flags |= O_TRUNC;
235 if (pflags & SSH2_FXF_EXCL)
236 flags |= O_EXCL;
237 return flags;
238 }
239
240 static const char *
string_from_portable(int pflags)241 string_from_portable(int pflags)
242 {
243 static char ret[128];
244
245 *ret = '\0';
246
247 #define PAPPEND(str) { \
248 if (*ret != '\0') \
249 strlcat(ret, ",", sizeof(ret)); \
250 strlcat(ret, str, sizeof(ret)); \
251 }
252
253 if (pflags & SSH2_FXF_READ)
254 PAPPEND("READ")
255 if (pflags & SSH2_FXF_WRITE)
256 PAPPEND("WRITE")
257 if (pflags & SSH2_FXF_APPEND)
258 PAPPEND("APPEND")
259 if (pflags & SSH2_FXF_CREAT)
260 PAPPEND("CREATE")
261 if (pflags & SSH2_FXF_TRUNC)
262 PAPPEND("TRUNCATE")
263 if (pflags & SSH2_FXF_EXCL)
264 PAPPEND("EXCL")
265
266 return ret;
267 }
268
269 /* handle handles */
270
271 typedef struct Handle Handle;
272 struct Handle {
273 int use;
274 DIR *dirp;
275 int fd;
276 int flags;
277 char *name;
278 u_int64_t bytes_read, bytes_write;
279 int next_unused;
280 };
281
282 enum {
283 HANDLE_UNUSED,
284 HANDLE_DIR,
285 HANDLE_FILE
286 };
287
288 Handle *handles = NULL;
289 u_int num_handles = 0;
290 int first_unused_handle = -1;
291
handle_unused(int i)292 static void handle_unused(int i)
293 {
294 handles[i].use = HANDLE_UNUSED;
295 handles[i].next_unused = first_unused_handle;
296 first_unused_handle = i;
297 }
298
299 static int
handle_new(int use,const char * name,int fd,int flags,DIR * dirp)300 handle_new(int use, const char *name, int fd, int flags, DIR *dirp)
301 {
302 int i;
303
304 if (first_unused_handle == -1) {
305 if (num_handles + 1 <= num_handles)
306 return -1;
307 num_handles++;
308 handles = xreallocarray(handles, num_handles, sizeof(Handle));
309 handle_unused(num_handles - 1);
310 }
311
312 i = first_unused_handle;
313 first_unused_handle = handles[i].next_unused;
314
315 handles[i].use = use;
316 handles[i].dirp = dirp;
317 handles[i].fd = fd;
318 handles[i].flags = flags;
319 handles[i].name = xstrdup(name);
320 handles[i].bytes_read = handles[i].bytes_write = 0;
321
322 return i;
323 }
324
325 static int
handle_is_ok(int i,int type)326 handle_is_ok(int i, int type)
327 {
328 return i >= 0 && (u_int)i < num_handles && handles[i].use == type;
329 }
330
331 static int
handle_to_string(int handle,u_char ** stringp,int * hlenp)332 handle_to_string(int handle, u_char **stringp, int *hlenp)
333 {
334 if (stringp == NULL || hlenp == NULL)
335 return -1;
336 *stringp = xmalloc(sizeof(int32_t));
337 put_u32(*stringp, handle);
338 *hlenp = sizeof(int32_t);
339 return 0;
340 }
341
342 static int
handle_from_string(const u_char * handle,u_int hlen)343 handle_from_string(const u_char *handle, u_int hlen)
344 {
345 int val;
346
347 if (hlen != sizeof(int32_t))
348 return -1;
349 val = get_u32(handle);
350 if (handle_is_ok(val, HANDLE_FILE) ||
351 handle_is_ok(val, HANDLE_DIR))
352 return val;
353 return -1;
354 }
355
356 static char *
handle_to_name(int handle)357 handle_to_name(int handle)
358 {
359 if (handle_is_ok(handle, HANDLE_DIR)||
360 handle_is_ok(handle, HANDLE_FILE))
361 return handles[handle].name;
362 return NULL;
363 }
364
365 static DIR *
handle_to_dir(int handle)366 handle_to_dir(int handle)
367 {
368 if (handle_is_ok(handle, HANDLE_DIR))
369 return handles[handle].dirp;
370 return NULL;
371 }
372
373 static int
handle_to_fd(int handle)374 handle_to_fd(int handle)
375 {
376 if (handle_is_ok(handle, HANDLE_FILE))
377 return handles[handle].fd;
378 return -1;
379 }
380
381 static int
handle_to_flags(int handle)382 handle_to_flags(int handle)
383 {
384 if (handle_is_ok(handle, HANDLE_FILE))
385 return handles[handle].flags;
386 return 0;
387 }
388
389 static void
handle_update_read(int handle,ssize_t bytes)390 handle_update_read(int handle, ssize_t bytes)
391 {
392 if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
393 handles[handle].bytes_read += bytes;
394 }
395
396 static void
handle_update_write(int handle,ssize_t bytes)397 handle_update_write(int handle, ssize_t bytes)
398 {
399 if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
400 handles[handle].bytes_write += bytes;
401 }
402
403 static u_int64_t
handle_bytes_read(int handle)404 handle_bytes_read(int handle)
405 {
406 if (handle_is_ok(handle, HANDLE_FILE))
407 return (handles[handle].bytes_read);
408 return 0;
409 }
410
411 static u_int64_t
handle_bytes_write(int handle)412 handle_bytes_write(int handle)
413 {
414 if (handle_is_ok(handle, HANDLE_FILE))
415 return (handles[handle].bytes_write);
416 return 0;
417 }
418
419 static int
handle_close(int handle)420 handle_close(int handle)
421 {
422 int ret = -1;
423
424 if (handle_is_ok(handle, HANDLE_FILE)) {
425 ret = close(handles[handle].fd);
426 free(handles[handle].name);
427 handle_unused(handle);
428 } else if (handle_is_ok(handle, HANDLE_DIR)) {
429 ret = closedir(handles[handle].dirp);
430 free(handles[handle].name);
431 handle_unused(handle);
432 } else {
433 errno = ENOENT;
434 }
435 return ret;
436 }
437
438 static void
handle_log_close(int handle,char * emsg)439 handle_log_close(int handle, char *emsg)
440 {
441 if (handle_is_ok(handle, HANDLE_FILE)) {
442 logit("%s%sclose \"%s\" bytes read %llu written %llu",
443 emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
444 handle_to_name(handle),
445 (unsigned long long)handle_bytes_read(handle),
446 (unsigned long long)handle_bytes_write(handle));
447 } else {
448 logit("%s%sclosedir \"%s\"",
449 emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
450 handle_to_name(handle));
451 }
452 }
453
454 static void
handle_log_exit(void)455 handle_log_exit(void)
456 {
457 u_int i;
458
459 for (i = 0; i < num_handles; i++)
460 if (handles[i].use != HANDLE_UNUSED)
461 handle_log_close(i, "forced");
462 }
463
464 static int
get_handle(struct sshbuf * queue,int * hp)465 get_handle(struct sshbuf *queue, int *hp)
466 {
467 u_char *handle;
468 int r;
469 size_t hlen;
470
471 *hp = -1;
472 if ((r = sshbuf_get_string(queue, &handle, &hlen)) != 0)
473 return r;
474 if (hlen < 256)
475 *hp = handle_from_string(handle, hlen);
476 free(handle);
477 return 0;
478 }
479
480 /* send replies */
481
482 static void
send_msg(struct sshbuf * m)483 send_msg(struct sshbuf *m)
484 {
485 int r;
486
487 if ((r = sshbuf_put_stringb(oqueue, m)) != 0)
488 fatal("%s: buffer error: %s", __func__, ssh_err(r));
489 sshbuf_reset(m);
490 }
491
492 static const char *
status_to_message(u_int32_t status)493 status_to_message(u_int32_t status)
494 {
495 const char *status_messages[] = {
496 "Success", /* SSH_FX_OK */
497 "End of file", /* SSH_FX_EOF */
498 "No such file", /* SSH_FX_NO_SUCH_FILE */
499 "Permission denied", /* SSH_FX_PERMISSION_DENIED */
500 "Failure", /* SSH_FX_FAILURE */
501 "Bad message", /* SSH_FX_BAD_MESSAGE */
502 "No connection", /* SSH_FX_NO_CONNECTION */
503 "Connection lost", /* SSH_FX_CONNECTION_LOST */
504 "Operation unsupported", /* SSH_FX_OP_UNSUPPORTED */
505 "Unknown error" /* Others */
506 };
507 return (status_messages[MINIMUM(status,SSH2_FX_MAX)]);
508 }
509
510 static void
send_status(u_int32_t id,u_int32_t status)511 send_status(u_int32_t id, u_int32_t status)
512 {
513 struct sshbuf *msg;
514 int r;
515
516 debug3("request %u: sent status %u", id, status);
517 if (log_level > SYSLOG_LEVEL_VERBOSE ||
518 (status != SSH2_FX_OK && status != SSH2_FX_EOF))
519 logit("sent status %s", status_to_message(status));
520 if ((msg = sshbuf_new()) == NULL)
521 fatal("%s: sshbuf_new failed", __func__);
522 if ((r = sshbuf_put_u8(msg, SSH2_FXP_STATUS)) != 0 ||
523 (r = sshbuf_put_u32(msg, id)) != 0 ||
524 (r = sshbuf_put_u32(msg, status)) != 0)
525 fatal("%s: buffer error: %s", __func__, ssh_err(r));
526 if (version >= 3) {
527 if ((r = sshbuf_put_cstring(msg,
528 status_to_message(status))) != 0 ||
529 (r = sshbuf_put_cstring(msg, "")) != 0)
530 fatal("%s: buffer error: %s", __func__, ssh_err(r));
531 }
532 send_msg(msg);
533 sshbuf_free(msg);
534 }
535 static void
send_data_or_handle(char type,u_int32_t id,const u_char * data,int dlen)536 send_data_or_handle(char type, u_int32_t id, const u_char *data, int dlen)
537 {
538 struct sshbuf *msg;
539 int r;
540
541 if ((msg = sshbuf_new()) == NULL)
542 fatal("%s: sshbuf_new failed", __func__);
543 if ((r = sshbuf_put_u8(msg, type)) != 0 ||
544 (r = sshbuf_put_u32(msg, id)) != 0 ||
545 (r = sshbuf_put_string(msg, data, dlen)) != 0)
546 fatal("%s: buffer error: %s", __func__, ssh_err(r));
547 send_msg(msg);
548 sshbuf_free(msg);
549 }
550
551 static void
send_data(u_int32_t id,const u_char * data,int dlen)552 send_data(u_int32_t id, const u_char *data, int dlen)
553 {
554 debug("request %u: sent data len %d", id, dlen);
555 send_data_or_handle(SSH2_FXP_DATA, id, data, dlen);
556 }
557
558 static void
send_handle(u_int32_t id,int handle)559 send_handle(u_int32_t id, int handle)
560 {
561 u_char *string;
562 int hlen;
563
564 handle_to_string(handle, &string, &hlen);
565 debug("request %u: sent handle handle %d", id, handle);
566 send_data_or_handle(SSH2_FXP_HANDLE, id, string, hlen);
567 free(string);
568 }
569
570 static void
send_names(u_int32_t id,int count,const Stat * stats)571 send_names(u_int32_t id, int count, const Stat *stats)
572 {
573 struct sshbuf *msg;
574 int i, r;
575
576 if ((msg = sshbuf_new()) == NULL)
577 fatal("%s: sshbuf_new failed", __func__);
578 if ((r = sshbuf_put_u8(msg, SSH2_FXP_NAME)) != 0 ||
579 (r = sshbuf_put_u32(msg, id)) != 0 ||
580 (r = sshbuf_put_u32(msg, count)) != 0)
581 fatal("%s: buffer error: %s", __func__, ssh_err(r));
582 debug("request %u: sent names count %d", id, count);
583 for (i = 0; i < count; i++) {
584 if ((r = sshbuf_put_cstring(msg, stats[i].name)) != 0 ||
585 (r = sshbuf_put_cstring(msg, stats[i].long_name)) != 0 ||
586 (r = encode_attrib(msg, &stats[i].attrib)) != 0)
587 fatal("%s: buffer error: %s", __func__, ssh_err(r));
588 }
589 send_msg(msg);
590 sshbuf_free(msg);
591 }
592
593 static void
send_attrib(u_int32_t id,const Attrib * a)594 send_attrib(u_int32_t id, const Attrib *a)
595 {
596 struct sshbuf *msg;
597 int r;
598
599 debug("request %u: sent attrib have 0x%x", id, a->flags);
600 if ((msg = sshbuf_new()) == NULL)
601 fatal("%s: sshbuf_new failed", __func__);
602 if ((r = sshbuf_put_u8(msg, SSH2_FXP_ATTRS)) != 0 ||
603 (r = sshbuf_put_u32(msg, id)) != 0 ||
604 (r = encode_attrib(msg, a)) != 0)
605 fatal("%s: buffer error: %s", __func__, ssh_err(r));
606 send_msg(msg);
607 sshbuf_free(msg);
608 }
609
610 static void
send_statvfs(u_int32_t id,struct statvfs * st)611 send_statvfs(u_int32_t id, struct statvfs *st)
612 {
613 struct sshbuf *msg;
614 u_int64_t flag;
615 int r;
616
617 flag = (st->f_flag & ST_RDONLY) ? SSH2_FXE_STATVFS_ST_RDONLY : 0;
618 flag |= (st->f_flag & ST_NOSUID) ? SSH2_FXE_STATVFS_ST_NOSUID : 0;
619
620 if ((msg = sshbuf_new()) == NULL)
621 fatal("%s: sshbuf_new failed", __func__);
622 if ((r = sshbuf_put_u8(msg, SSH2_FXP_EXTENDED_REPLY)) != 0 ||
623 (r = sshbuf_put_u32(msg, id)) != 0 ||
624 (r = sshbuf_put_u64(msg, st->f_bsize)) != 0 ||
625 (r = sshbuf_put_u64(msg, st->f_frsize)) != 0 ||
626 (r = sshbuf_put_u64(msg, st->f_blocks)) != 0 ||
627 (r = sshbuf_put_u64(msg, st->f_bfree)) != 0 ||
628 (r = sshbuf_put_u64(msg, st->f_bavail)) != 0 ||
629 (r = sshbuf_put_u64(msg, st->f_files)) != 0 ||
630 (r = sshbuf_put_u64(msg, st->f_ffree)) != 0 ||
631 (r = sshbuf_put_u64(msg, st->f_favail)) != 0 ||
632 (r = sshbuf_put_u64(msg, FSID_TO_ULONG(st->f_fsid))) != 0 ||
633 (r = sshbuf_put_u64(msg, flag)) != 0 ||
634 (r = sshbuf_put_u64(msg, st->f_namemax)) != 0)
635 fatal("%s: buffer error: %s", __func__, ssh_err(r));
636 send_msg(msg);
637 sshbuf_free(msg);
638 }
639
640 /* parse incoming */
641
642 static void
process_init(void)643 process_init(void)
644 {
645 struct sshbuf *msg;
646 int r;
647
648 if ((r = sshbuf_get_u32(iqueue, &version)) != 0)
649 fatal("%s: buffer error: %s", __func__, ssh_err(r));
650 verbose("received client version %u", version);
651 if ((msg = sshbuf_new()) == NULL)
652 fatal("%s: sshbuf_new failed", __func__);
653 if ((r = sshbuf_put_u8(msg, SSH2_FXP_VERSION)) != 0 ||
654 (r = sshbuf_put_u32(msg, SSH2_FILEXFER_VERSION)) != 0 ||
655 /* POSIX rename extension */
656 (r = sshbuf_put_cstring(msg, "posix-rename@openssh.com")) != 0 ||
657 (r = sshbuf_put_cstring(msg, "1")) != 0 || /* version */
658 /* statvfs extension */
659 (r = sshbuf_put_cstring(msg, "statvfs@openssh.com")) != 0 ||
660 (r = sshbuf_put_cstring(msg, "2")) != 0 || /* version */
661 /* fstatvfs extension */
662 (r = sshbuf_put_cstring(msg, "fstatvfs@openssh.com")) != 0 ||
663 (r = sshbuf_put_cstring(msg, "2")) != 0 || /* version */
664 /* hardlink extension */
665 (r = sshbuf_put_cstring(msg, "hardlink@openssh.com")) != 0 ||
666 (r = sshbuf_put_cstring(msg, "1")) != 0 || /* version */
667 /* fsync extension */
668 (r = sshbuf_put_cstring(msg, "fsync@openssh.com")) != 0 ||
669 (r = sshbuf_put_cstring(msg, "1")) != 0) /* version */
670 fatal("%s: buffer error: %s", __func__, ssh_err(r));
671 send_msg(msg);
672 sshbuf_free(msg);
673 }
674
675 static void
process_open(u_int32_t id)676 process_open(u_int32_t id)
677 {
678 u_int32_t pflags;
679 Attrib a;
680 char *name;
681 int r, handle, fd, flags, mode, status = SSH2_FX_FAILURE;
682
683 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
684 (r = sshbuf_get_u32(iqueue, &pflags)) != 0 || /* portable flags */
685 (r = decode_attrib(iqueue, &a)) != 0)
686 fatal("%s: buffer error: %s", __func__, ssh_err(r));
687
688 debug3("request %u: open flags %d", id, pflags);
689 flags = flags_from_portable(pflags);
690 mode = (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? a.perm : 0666;
691 logit("open \"%s\" flags %s mode 0%o",
692 name, string_from_portable(pflags), mode);
693 if (readonly &&
694 ((flags & O_ACCMODE) == O_WRONLY ||
695 (flags & O_ACCMODE) == O_RDWR)) {
696 verbose("Refusing open request in read-only mode");
697 status = SSH2_FX_PERMISSION_DENIED;
698 } else {
699 fd = open(name, flags, mode);
700 if (fd < 0) {
701 status = errno_to_portable(errno);
702 } else {
703 handle = handle_new(HANDLE_FILE, name, fd, flags, NULL);
704 if (handle < 0) {
705 close(fd);
706 } else {
707 send_handle(id, handle);
708 status = SSH2_FX_OK;
709 }
710 }
711 }
712 if (status != SSH2_FX_OK)
713 send_status(id, status);
714 free(name);
715 }
716
717 static void
process_close(u_int32_t id)718 process_close(u_int32_t id)
719 {
720 int r, handle, ret, status = SSH2_FX_FAILURE;
721
722 if ((r = get_handle(iqueue, &handle)) != 0)
723 fatal("%s: buffer error: %s", __func__, ssh_err(r));
724
725 debug3("request %u: close handle %u", id, handle);
726 handle_log_close(handle, NULL);
727 ret = handle_close(handle);
728 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
729 send_status(id, status);
730 }
731
732 static void
process_read(u_int32_t id)733 process_read(u_int32_t id)
734 {
735 u_char buf[64*1024];
736 u_int32_t len;
737 int r, handle, fd, ret, status = SSH2_FX_FAILURE;
738 u_int64_t off;
739
740 if ((r = get_handle(iqueue, &handle)) != 0 ||
741 (r = sshbuf_get_u64(iqueue, &off)) != 0 ||
742 (r = sshbuf_get_u32(iqueue, &len)) != 0)
743 fatal("%s: buffer error: %s", __func__, ssh_err(r));
744
745 debug("request %u: read \"%s\" (handle %d) off %llu len %d",
746 id, handle_to_name(handle), handle, (unsigned long long)off, len);
747 if (len > sizeof buf) {
748 len = sizeof buf;
749 debug2("read change len %d", len);
750 }
751 fd = handle_to_fd(handle);
752 if (fd >= 0) {
753 if (lseek(fd, off, SEEK_SET) < 0) {
754 error("process_read: seek failed");
755 status = errno_to_portable(errno);
756 } else {
757 ret = read(fd, buf, len);
758 if (ret < 0) {
759 status = errno_to_portable(errno);
760 } else if (ret == 0) {
761 status = SSH2_FX_EOF;
762 } else {
763 send_data(id, buf, ret);
764 status = SSH2_FX_OK;
765 handle_update_read(handle, ret);
766 }
767 }
768 }
769 if (status != SSH2_FX_OK)
770 send_status(id, status);
771 }
772
773 static void
process_write(u_int32_t id)774 process_write(u_int32_t id)
775 {
776 u_int64_t off;
777 size_t len;
778 int r, handle, fd, ret, status;
779 u_char *data;
780
781 if ((r = get_handle(iqueue, &handle)) != 0 ||
782 (r = sshbuf_get_u64(iqueue, &off)) != 0 ||
783 (r = sshbuf_get_string(iqueue, &data, &len)) != 0)
784 fatal("%s: buffer error: %s", __func__, ssh_err(r));
785
786 debug("request %u: write \"%s\" (handle %d) off %llu len %zu",
787 id, handle_to_name(handle), handle, (unsigned long long)off, len);
788 fd = handle_to_fd(handle);
789
790 if (fd < 0)
791 status = SSH2_FX_FAILURE;
792 else {
793 if (!(handle_to_flags(handle) & O_APPEND) &&
794 lseek(fd, off, SEEK_SET) < 0) {
795 status = errno_to_portable(errno);
796 error("process_write: seek failed");
797 } else {
798 /* XXX ATOMICIO ? */
799 ret = write(fd, data, len);
800 if (ret < 0) {
801 error("process_write: write failed");
802 status = errno_to_portable(errno);
803 } else if ((size_t)ret == len) {
804 status = SSH2_FX_OK;
805 handle_update_write(handle, ret);
806 } else {
807 debug2("nothing at all written");
808 status = SSH2_FX_FAILURE;
809 }
810 }
811 }
812 send_status(id, status);
813 free(data);
814 }
815
816 static void
process_do_stat(u_int32_t id,int do_lstat)817 process_do_stat(u_int32_t id, int do_lstat)
818 {
819 Attrib a;
820 struct stat st;
821 char *name;
822 int r, status = SSH2_FX_FAILURE;
823
824 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
825 fatal("%s: buffer error: %s", __func__, ssh_err(r));
826
827 debug3("request %u: %sstat", id, do_lstat ? "l" : "");
828 verbose("%sstat name \"%s\"", do_lstat ? "l" : "", name);
829 r = do_lstat ? lstat(name, &st) : stat(name, &st);
830 if (r < 0) {
831 status = errno_to_portable(errno);
832 } else {
833 stat_to_attrib(&st, &a);
834 send_attrib(id, &a);
835 status = SSH2_FX_OK;
836 }
837 if (status != SSH2_FX_OK)
838 send_status(id, status);
839 free(name);
840 }
841
842 static void
process_stat(u_int32_t id)843 process_stat(u_int32_t id)
844 {
845 process_do_stat(id, 0);
846 }
847
848 static void
process_lstat(u_int32_t id)849 process_lstat(u_int32_t id)
850 {
851 process_do_stat(id, 1);
852 }
853
854 static void
process_fstat(u_int32_t id)855 process_fstat(u_int32_t id)
856 {
857 Attrib a;
858 struct stat st;
859 int fd, r, handle, status = SSH2_FX_FAILURE;
860
861 if ((r = get_handle(iqueue, &handle)) != 0)
862 fatal("%s: buffer error: %s", __func__, ssh_err(r));
863 debug("request %u: fstat \"%s\" (handle %u)",
864 id, handle_to_name(handle), handle);
865 fd = handle_to_fd(handle);
866 if (fd >= 0) {
867 r = fstat(fd, &st);
868 if (r < 0) {
869 status = errno_to_portable(errno);
870 } else {
871 stat_to_attrib(&st, &a);
872 send_attrib(id, &a);
873 status = SSH2_FX_OK;
874 }
875 }
876 if (status != SSH2_FX_OK)
877 send_status(id, status);
878 }
879
880 static struct timeval *
attrib_to_tv(const Attrib * a)881 attrib_to_tv(const Attrib *a)
882 {
883 static struct timeval tv[2];
884
885 tv[0].tv_sec = a->atime;
886 tv[0].tv_usec = 0;
887 tv[1].tv_sec = a->mtime;
888 tv[1].tv_usec = 0;
889 return tv;
890 }
891
892 static void
process_setstat(u_int32_t id)893 process_setstat(u_int32_t id)
894 {
895 Attrib a;
896 char *name;
897 int r, status = SSH2_FX_OK;
898
899 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
900 (r = decode_attrib(iqueue, &a)) != 0)
901 fatal("%s: buffer error: %s", __func__, ssh_err(r));
902
903 debug("request %u: setstat name \"%s\"", id, name);
904 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) {
905 logit("set \"%s\" size %llu",
906 name, (unsigned long long)a.size);
907 r = truncate(name, a.size);
908 if (r == -1)
909 status = errno_to_portable(errno);
910 }
911 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
912 logit("set \"%s\" mode %04o", name, a.perm);
913 r = chmod(name, a.perm & 07777);
914 if (r == -1)
915 status = errno_to_portable(errno);
916 }
917 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
918 char buf[64];
919 time_t t = a.mtime;
920
921 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
922 localtime(&t));
923 logit("set \"%s\" modtime %s", name, buf);
924 r = utimes(name, attrib_to_tv(&a));
925 if (r == -1)
926 status = errno_to_portable(errno);
927 }
928 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) {
929 logit("set \"%s\" owner %lu group %lu", name,
930 (u_long)a.uid, (u_long)a.gid);
931 r = chown(name, a.uid, a.gid);
932 if (r == -1)
933 status = errno_to_portable(errno);
934 }
935 send_status(id, status);
936 free(name);
937 }
938
939 static void
process_fsetstat(u_int32_t id)940 process_fsetstat(u_int32_t id)
941 {
942 Attrib a;
943 int handle, fd, r;
944 int status = SSH2_FX_OK;
945
946 if ((r = get_handle(iqueue, &handle)) != 0 ||
947 (r = decode_attrib(iqueue, &a)) != 0)
948 fatal("%s: buffer error: %s", __func__, ssh_err(r));
949
950 debug("request %u: fsetstat handle %d", id, handle);
951 fd = handle_to_fd(handle);
952 if (fd < 0)
953 status = SSH2_FX_FAILURE;
954 else {
955 char *name = handle_to_name(handle);
956
957 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) {
958 logit("set \"%s\" size %llu",
959 name, (unsigned long long)a.size);
960 r = ftruncate(fd, a.size);
961 if (r == -1)
962 status = errno_to_portable(errno);
963 }
964 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
965 logit("set \"%s\" mode %04o", name, a.perm);
966 #ifdef HAVE_FCHMOD
967 r = fchmod(fd, a.perm & 07777);
968 #else
969 r = chmod(name, a.perm & 07777);
970 #endif
971 if (r == -1)
972 status = errno_to_portable(errno);
973 }
974 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
975 char buf[64];
976 time_t t = a.mtime;
977
978 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
979 localtime(&t));
980 logit("set \"%s\" modtime %s", name, buf);
981 #ifdef HAVE_FUTIMES
982 r = futimes(fd, attrib_to_tv(&a));
983 #else
984 r = utimes(name, attrib_to_tv(&a));
985 #endif
986 if (r == -1)
987 status = errno_to_portable(errno);
988 }
989 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) {
990 logit("set \"%s\" owner %lu group %lu", name,
991 (u_long)a.uid, (u_long)a.gid);
992 #ifdef HAVE_FCHOWN
993 r = fchown(fd, a.uid, a.gid);
994 #else
995 r = chown(name, a.uid, a.gid);
996 #endif
997 if (r == -1)
998 status = errno_to_portable(errno);
999 }
1000 }
1001 send_status(id, status);
1002 }
1003
1004 static void
process_opendir(u_int32_t id)1005 process_opendir(u_int32_t id)
1006 {
1007 DIR *dirp = NULL;
1008 char *path;
1009 int r, handle, status = SSH2_FX_FAILURE;
1010
1011 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1012 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1013
1014 debug3("request %u: opendir", id);
1015 logit("opendir \"%s\"", path);
1016 dirp = opendir(path);
1017 if (dirp == NULL) {
1018 status = errno_to_portable(errno);
1019 } else {
1020 handle = handle_new(HANDLE_DIR, path, 0, 0, dirp);
1021 if (handle < 0) {
1022 closedir(dirp);
1023 } else {
1024 send_handle(id, handle);
1025 status = SSH2_FX_OK;
1026 }
1027
1028 }
1029 if (status != SSH2_FX_OK)
1030 send_status(id, status);
1031 free(path);
1032 }
1033
1034 static void
process_readdir(u_int32_t id)1035 process_readdir(u_int32_t id)
1036 {
1037 DIR *dirp;
1038 struct dirent *dp;
1039 char *path;
1040 int r, handle;
1041
1042 if ((r = get_handle(iqueue, &handle)) != 0)
1043 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1044
1045 debug("request %u: readdir \"%s\" (handle %d)", id,
1046 handle_to_name(handle), handle);
1047 dirp = handle_to_dir(handle);
1048 path = handle_to_name(handle);
1049 if (dirp == NULL || path == NULL) {
1050 send_status(id, SSH2_FX_FAILURE);
1051 } else {
1052 struct stat st;
1053 char pathname[PATH_MAX];
1054 Stat *stats;
1055 int nstats = 10, count = 0, i;
1056
1057 stats = xcalloc(nstats, sizeof(Stat));
1058 while ((dp = readdir(dirp)) != NULL) {
1059 if (count >= nstats) {
1060 nstats *= 2;
1061 stats = xreallocarray(stats, nstats, sizeof(Stat));
1062 }
1063 /* XXX OVERFLOW ? */
1064 snprintf(pathname, sizeof pathname, "%s%s%s", path,
1065 strcmp(path, "/") ? "/" : "", dp->d_name);
1066 if (lstat(pathname, &st) < 0)
1067 continue;
1068 stat_to_attrib(&st, &(stats[count].attrib));
1069 stats[count].name = xstrdup(dp->d_name);
1070 stats[count].long_name = ls_file(dp->d_name, &st, 0, 0);
1071 count++;
1072 /* send up to 100 entries in one message */
1073 /* XXX check packet size instead */
1074 if (count == 100)
1075 break;
1076 }
1077 if (count > 0) {
1078 send_names(id, count, stats);
1079 for (i = 0; i < count; i++) {
1080 free(stats[i].name);
1081 free(stats[i].long_name);
1082 }
1083 } else {
1084 send_status(id, SSH2_FX_EOF);
1085 }
1086 free(stats);
1087 }
1088 }
1089
1090 static void
process_remove(u_int32_t id)1091 process_remove(u_int32_t id)
1092 {
1093 char *name;
1094 int r, status = SSH2_FX_FAILURE;
1095
1096 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
1097 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1098
1099 debug3("request %u: remove", id);
1100 logit("remove name \"%s\"", name);
1101 r = unlink(name);
1102 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1103 send_status(id, status);
1104 free(name);
1105 }
1106
1107 static void
process_mkdir(u_int32_t id)1108 process_mkdir(u_int32_t id)
1109 {
1110 Attrib a;
1111 char *name;
1112 int r, mode, status = SSH2_FX_FAILURE;
1113
1114 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
1115 (r = decode_attrib(iqueue, &a)) != 0)
1116 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1117
1118 mode = (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ?
1119 a.perm & 07777 : 0777;
1120 debug3("request %u: mkdir", id);
1121 logit("mkdir name \"%s\" mode 0%o", name, mode);
1122 r = mkdir(name, mode);
1123 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1124 send_status(id, status);
1125 free(name);
1126 }
1127
1128 static void
process_rmdir(u_int32_t id)1129 process_rmdir(u_int32_t id)
1130 {
1131 char *name;
1132 int r, status;
1133
1134 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
1135 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1136
1137 debug3("request %u: rmdir", id);
1138 logit("rmdir name \"%s\"", name);
1139 r = rmdir(name);
1140 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1141 send_status(id, status);
1142 free(name);
1143 }
1144
1145 static void
process_realpath(u_int32_t id)1146 process_realpath(u_int32_t id)
1147 {
1148 char resolvedname[PATH_MAX];
1149 char *path;
1150 int r;
1151
1152 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1153 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1154
1155 if (path[0] == '\0') {
1156 free(path);
1157 path = xstrdup(".");
1158 }
1159 debug3("request %u: realpath", id);
1160 verbose("realpath \"%s\"", path);
1161 if (realpath(path, resolvedname) == NULL) {
1162 send_status(id, errno_to_portable(errno));
1163 } else {
1164 Stat s;
1165 attrib_clear(&s.attrib);
1166 s.name = s.long_name = resolvedname;
1167 send_names(id, 1, &s);
1168 }
1169 free(path);
1170 }
1171
1172 static void
process_rename(u_int32_t id)1173 process_rename(u_int32_t id)
1174 {
1175 char *oldpath, *newpath;
1176 int r, status;
1177 struct stat sb;
1178
1179 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
1180 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
1181 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1182
1183 debug3("request %u: rename", id);
1184 logit("rename old \"%s\" new \"%s\"", oldpath, newpath);
1185 status = SSH2_FX_FAILURE;
1186 if (lstat(oldpath, &sb) == -1)
1187 status = errno_to_portable(errno);
1188 else if (S_ISREG(sb.st_mode)) {
1189 /* Race-free rename of regular files */
1190 if (link(oldpath, newpath) == -1) {
1191 if (errno == EOPNOTSUPP || errno == ENOSYS
1192 #ifdef EXDEV
1193 || errno == EXDEV
1194 #endif
1195 #ifdef LINK_OPNOTSUPP_ERRNO
1196 || errno == LINK_OPNOTSUPP_ERRNO
1197 #endif
1198 ) {
1199 struct stat st;
1200
1201 /*
1202 * fs doesn't support links, so fall back to
1203 * stat+rename. This is racy.
1204 */
1205 if (stat(newpath, &st) == -1) {
1206 if (rename(oldpath, newpath) == -1)
1207 status =
1208 errno_to_portable(errno);
1209 else
1210 status = SSH2_FX_OK;
1211 }
1212 } else {
1213 status = errno_to_portable(errno);
1214 }
1215 } else if (unlink(oldpath) == -1) {
1216 status = errno_to_portable(errno);
1217 /* clean spare link */
1218 unlink(newpath);
1219 } else
1220 status = SSH2_FX_OK;
1221 } else if (stat(newpath, &sb) == -1) {
1222 if (rename(oldpath, newpath) == -1)
1223 status = errno_to_portable(errno);
1224 else
1225 status = SSH2_FX_OK;
1226 }
1227 send_status(id, status);
1228 free(oldpath);
1229 free(newpath);
1230 }
1231
1232 static void
process_readlink(u_int32_t id)1233 process_readlink(u_int32_t id)
1234 {
1235 int r, len;
1236 char buf[PATH_MAX];
1237 char *path;
1238
1239 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1240 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1241
1242 debug3("request %u: readlink", id);
1243 verbose("readlink \"%s\"", path);
1244 if ((len = readlink(path, buf, sizeof(buf) - 1)) == -1)
1245 send_status(id, errno_to_portable(errno));
1246 else {
1247 Stat s;
1248
1249 buf[len] = '\0';
1250 attrib_clear(&s.attrib);
1251 s.name = s.long_name = buf;
1252 send_names(id, 1, &s);
1253 }
1254 free(path);
1255 }
1256
1257 static void
process_symlink(u_int32_t id)1258 process_symlink(u_int32_t id)
1259 {
1260 char *oldpath, *newpath;
1261 int r, status;
1262
1263 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
1264 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
1265 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1266
1267 debug3("request %u: symlink", id);
1268 logit("symlink old \"%s\" new \"%s\"", oldpath, newpath);
1269 /* this will fail if 'newpath' exists */
1270 r = symlink(oldpath, newpath);
1271 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1272 send_status(id, status);
1273 free(oldpath);
1274 free(newpath);
1275 }
1276
1277 static void
process_extended_posix_rename(u_int32_t id)1278 process_extended_posix_rename(u_int32_t id)
1279 {
1280 char *oldpath, *newpath;
1281 int r, status;
1282
1283 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
1284 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
1285 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1286
1287 debug3("request %u: posix-rename", id);
1288 logit("posix-rename old \"%s\" new \"%s\"", oldpath, newpath);
1289 r = rename(oldpath, newpath);
1290 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1291 send_status(id, status);
1292 free(oldpath);
1293 free(newpath);
1294 }
1295
1296 static void
process_extended_statvfs(u_int32_t id)1297 process_extended_statvfs(u_int32_t id)
1298 {
1299 char *path;
1300 struct statvfs st;
1301 int r;
1302
1303 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1304 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1305 debug3("request %u: statvfs", id);
1306 logit("statvfs \"%s\"", path);
1307
1308 if (statvfs(path, &st) != 0)
1309 send_status(id, errno_to_portable(errno));
1310 else
1311 send_statvfs(id, &st);
1312 free(path);
1313 }
1314
1315 static void
process_extended_fstatvfs(u_int32_t id)1316 process_extended_fstatvfs(u_int32_t id)
1317 {
1318 int r, handle, fd;
1319 struct statvfs st;
1320
1321 if ((r = get_handle(iqueue, &handle)) != 0)
1322 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1323 debug("request %u: fstatvfs \"%s\" (handle %u)",
1324 id, handle_to_name(handle), handle);
1325 if ((fd = handle_to_fd(handle)) < 0) {
1326 send_status(id, SSH2_FX_FAILURE);
1327 return;
1328 }
1329 if (fstatvfs(fd, &st) != 0)
1330 send_status(id, errno_to_portable(errno));
1331 else
1332 send_statvfs(id, &st);
1333 }
1334
1335 static void
process_extended_hardlink(u_int32_t id)1336 process_extended_hardlink(u_int32_t id)
1337 {
1338 char *oldpath, *newpath;
1339 int r, status;
1340
1341 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
1342 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
1343 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1344
1345 debug3("request %u: hardlink", id);
1346 logit("hardlink old \"%s\" new \"%s\"", oldpath, newpath);
1347 r = link(oldpath, newpath);
1348 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1349 send_status(id, status);
1350 free(oldpath);
1351 free(newpath);
1352 }
1353
1354 static void
process_extended_fsync(u_int32_t id)1355 process_extended_fsync(u_int32_t id)
1356 {
1357 int handle, fd, r, status = SSH2_FX_OP_UNSUPPORTED;
1358
1359 if ((r = get_handle(iqueue, &handle)) != 0)
1360 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1361 debug3("request %u: fsync (handle %u)", id, handle);
1362 verbose("fsync \"%s\"", handle_to_name(handle));
1363 if ((fd = handle_to_fd(handle)) < 0)
1364 status = SSH2_FX_NO_SUCH_FILE;
1365 else if (handle_is_ok(handle, HANDLE_FILE)) {
1366 r = fsync(fd);
1367 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1368 }
1369 send_status(id, status);
1370 }
1371
1372 static void
process_extended(u_int32_t id)1373 process_extended(u_int32_t id)
1374 {
1375 char *request;
1376 int i, r;
1377
1378 if ((r = sshbuf_get_cstring(iqueue, &request, NULL)) != 0)
1379 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1380 for (i = 0; extended_handlers[i].handler != NULL; i++) {
1381 if (strcmp(request, extended_handlers[i].ext_name) == 0) {
1382 if (!request_permitted(&extended_handlers[i]))
1383 send_status(id, SSH2_FX_PERMISSION_DENIED);
1384 else
1385 extended_handlers[i].handler(id);
1386 break;
1387 }
1388 }
1389 if (extended_handlers[i].handler == NULL) {
1390 error("Unknown extended request \"%.100s\"", request);
1391 send_status(id, SSH2_FX_OP_UNSUPPORTED); /* MUST */
1392 }
1393 free(request);
1394 }
1395
1396 /* stolen from ssh-agent */
1397
1398 static void
process(void)1399 process(void)
1400 {
1401 u_int msg_len;
1402 u_int buf_len;
1403 u_int consumed;
1404 u_char type;
1405 const u_char *cp;
1406 int i, r;
1407 u_int32_t id;
1408
1409 buf_len = sshbuf_len(iqueue);
1410 if (buf_len < 5)
1411 return; /* Incomplete message. */
1412 cp = sshbuf_ptr(iqueue);
1413 msg_len = get_u32(cp);
1414 if (msg_len > SFTP_MAX_MSG_LENGTH) {
1415 error("bad message from %s local user %s",
1416 client_addr, pw->pw_name);
1417 sftp_server_cleanup_exit(11);
1418 }
1419 if (buf_len < msg_len + 4)
1420 return;
1421 if ((r = sshbuf_consume(iqueue, 4)) != 0)
1422 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1423 buf_len -= 4;
1424 if ((r = sshbuf_get_u8(iqueue, &type)) != 0)
1425 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1426
1427 switch (type) {
1428 case SSH2_FXP_INIT:
1429 process_init();
1430 init_done = 1;
1431 break;
1432 case SSH2_FXP_EXTENDED:
1433 if (!init_done)
1434 fatal("Received extended request before init");
1435 if ((r = sshbuf_get_u32(iqueue, &id)) != 0)
1436 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1437 process_extended(id);
1438 break;
1439 default:
1440 if (!init_done)
1441 fatal("Received %u request before init", type);
1442 if ((r = sshbuf_get_u32(iqueue, &id)) != 0)
1443 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1444 for (i = 0; handlers[i].handler != NULL; i++) {
1445 if (type == handlers[i].type) {
1446 if (!request_permitted(&handlers[i])) {
1447 send_status(id,
1448 SSH2_FX_PERMISSION_DENIED);
1449 } else {
1450 handlers[i].handler(id);
1451 }
1452 break;
1453 }
1454 }
1455 if (handlers[i].handler == NULL)
1456 error("Unknown message %u", type);
1457 }
1458 /* discard the remaining bytes from the current packet */
1459 if (buf_len < sshbuf_len(iqueue)) {
1460 error("iqueue grew unexpectedly");
1461 sftp_server_cleanup_exit(255);
1462 }
1463 consumed = buf_len - sshbuf_len(iqueue);
1464 if (msg_len < consumed) {
1465 error("msg_len %u < consumed %u", msg_len, consumed);
1466 sftp_server_cleanup_exit(255);
1467 }
1468 if (msg_len > consumed &&
1469 (r = sshbuf_consume(iqueue, msg_len - consumed)) != 0)
1470 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1471 }
1472
1473 /* Cleanup handler that logs active handles upon normal exit */
1474 void
sftp_server_cleanup_exit(int i)1475 sftp_server_cleanup_exit(int i)
1476 {
1477 if (pw != NULL && client_addr != NULL) {
1478 handle_log_exit();
1479 logit("session closed for local user %s from [%s]",
1480 pw->pw_name, client_addr);
1481 }
1482 _exit(i);
1483 }
1484
1485 static void
sftp_server_usage(void)1486 sftp_server_usage(void)
1487 {
1488 extern char *__progname;
1489
1490 fprintf(stderr,
1491 "usage: %s [-ehR] [-d start_directory] [-f log_facility] "
1492 "[-l log_level]\n\t[-P blacklisted_requests] "
1493 "[-p whitelisted_requests] [-u umask]\n"
1494 " %s -Q protocol_feature\n",
1495 __progname, __progname);
1496 exit(1);
1497 }
1498
1499 int
sftp_server_main(int argc,char ** argv,struct passwd * user_pw)1500 sftp_server_main(int argc, char **argv, struct passwd *user_pw)
1501 {
1502 fd_set *rset, *wset;
1503 int i, r, in, out, max, ch, skipargs = 0, log_stderr = 0;
1504 ssize_t len, olen, set_size;
1505 SyslogFacility log_facility = SYSLOG_FACILITY_AUTH;
1506 char *cp, *homedir = NULL, buf[4*4096];
1507 long mask;
1508
1509 extern char *optarg;
1510 extern char *__progname;
1511
1512 ssh_malloc_init(); /* must be called before any mallocs */
1513 __progname = ssh_get_progname(argv[0]);
1514 log_init(__progname, log_level, log_facility, log_stderr);
1515
1516 pw = pwcopy(user_pw);
1517
1518 while (!skipargs && (ch = getopt(argc, argv,
1519 "d:f:l:P:p:Q:u:cehR")) != -1) {
1520 switch (ch) {
1521 case 'Q':
1522 if (strcasecmp(optarg, "requests") != 0) {
1523 fprintf(stderr, "Invalid query type\n");
1524 exit(1);
1525 }
1526 for (i = 0; handlers[i].handler != NULL; i++)
1527 printf("%s\n", handlers[i].name);
1528 for (i = 0; extended_handlers[i].handler != NULL; i++)
1529 printf("%s\n", extended_handlers[i].name);
1530 exit(0);
1531 break;
1532 case 'R':
1533 readonly = 1;
1534 break;
1535 case 'c':
1536 /*
1537 * Ignore all arguments if we are invoked as a
1538 * shell using "sftp-server -c command"
1539 */
1540 skipargs = 1;
1541 break;
1542 case 'e':
1543 log_stderr = 1;
1544 break;
1545 case 'l':
1546 log_level = log_level_number(optarg);
1547 if (log_level == SYSLOG_LEVEL_NOT_SET)
1548 error("Invalid log level \"%s\"", optarg);
1549 break;
1550 case 'f':
1551 log_facility = log_facility_number(optarg);
1552 if (log_facility == SYSLOG_FACILITY_NOT_SET)
1553 error("Invalid log facility \"%s\"", optarg);
1554 break;
1555 case 'd':
1556 cp = tilde_expand_filename(optarg, user_pw->pw_uid);
1557 homedir = percent_expand(cp, "d", user_pw->pw_dir,
1558 "u", user_pw->pw_name, (char *)NULL);
1559 free(cp);
1560 break;
1561 case 'p':
1562 if (request_whitelist != NULL)
1563 fatal("Permitted requests already set");
1564 request_whitelist = xstrdup(optarg);
1565 break;
1566 case 'P':
1567 if (request_blacklist != NULL)
1568 fatal("Refused requests already set");
1569 request_blacklist = xstrdup(optarg);
1570 break;
1571 case 'u':
1572 errno = 0;
1573 mask = strtol(optarg, &cp, 8);
1574 if (mask < 0 || mask > 0777 || *cp != '\0' ||
1575 cp == optarg || (mask == 0 && errno != 0))
1576 fatal("Invalid umask \"%s\"", optarg);
1577 (void)umask((mode_t)mask);
1578 break;
1579 case 'h':
1580 default:
1581 sftp_server_usage();
1582 }
1583 }
1584
1585 log_init(__progname, log_level, log_facility, log_stderr);
1586
1587 /*
1588 * On platforms where we can, avoid making /proc/self/{mem,maps}
1589 * available to the user so that sftp access doesn't automatically
1590 * imply arbitrary code execution access that will break
1591 * restricted configurations.
1592 */
1593 platform_disable_tracing(1); /* strict */
1594
1595 /* Drop any fine-grained privileges we don't need */
1596 platform_pledge_sftp_server();
1597
1598 if ((cp = getenv("SSH_CONNECTION")) != NULL) {
1599 client_addr = xstrdup(cp);
1600 if ((cp = strchr(client_addr, ' ')) == NULL) {
1601 error("Malformed SSH_CONNECTION variable: \"%s\"",
1602 getenv("SSH_CONNECTION"));
1603 sftp_server_cleanup_exit(255);
1604 }
1605 *cp = '\0';
1606 } else
1607 client_addr = xstrdup("UNKNOWN");
1608
1609 logit("session opened for local user %s from [%s]",
1610 pw->pw_name, client_addr);
1611
1612 in = STDIN_FILENO;
1613 out = STDOUT_FILENO;
1614
1615 #ifdef HAVE_CYGWIN
1616 setmode(in, O_BINARY);
1617 setmode(out, O_BINARY);
1618 #endif
1619
1620 max = 0;
1621 if (in > max)
1622 max = in;
1623 if (out > max)
1624 max = out;
1625
1626 if ((iqueue = sshbuf_new()) == NULL)
1627 fatal("%s: sshbuf_new failed", __func__);
1628 if ((oqueue = sshbuf_new()) == NULL)
1629 fatal("%s: sshbuf_new failed", __func__);
1630
1631 rset = xcalloc(howmany(max + 1, NFDBITS), sizeof(fd_mask));
1632 wset = xcalloc(howmany(max + 1, NFDBITS), sizeof(fd_mask));
1633
1634 if (homedir != NULL) {
1635 if (chdir(homedir) != 0) {
1636 error("chdir to \"%s\" failed: %s", homedir,
1637 strerror(errno));
1638 }
1639 }
1640
1641 set_size = howmany(max + 1, NFDBITS) * sizeof(fd_mask);
1642 for (;;) {
1643 memset(rset, 0, set_size);
1644 memset(wset, 0, set_size);
1645
1646 /*
1647 * Ensure that we can read a full buffer and handle
1648 * the worst-case length packet it can generate,
1649 * otherwise apply backpressure by stopping reads.
1650 */
1651 if ((r = sshbuf_check_reserve(iqueue, sizeof(buf))) == 0 &&
1652 (r = sshbuf_check_reserve(oqueue,
1653 SFTP_MAX_MSG_LENGTH)) == 0)
1654 FD_SET(in, rset);
1655 else if (r != SSH_ERR_NO_BUFFER_SPACE)
1656 fatal("%s: sshbuf_check_reserve failed: %s",
1657 __func__, ssh_err(r));
1658
1659 olen = sshbuf_len(oqueue);
1660 if (olen > 0)
1661 FD_SET(out, wset);
1662
1663 if (select(max+1, rset, wset, NULL, NULL) < 0) {
1664 if (errno == EINTR)
1665 continue;
1666 error("select: %s", strerror(errno));
1667 sftp_server_cleanup_exit(2);
1668 }
1669
1670 /* copy stdin to iqueue */
1671 if (FD_ISSET(in, rset)) {
1672 len = read(in, buf, sizeof buf);
1673 if (len == 0) {
1674 debug("read eof");
1675 sftp_server_cleanup_exit(0);
1676 } else if (len < 0) {
1677 error("read: %s", strerror(errno));
1678 sftp_server_cleanup_exit(1);
1679 } else if ((r = sshbuf_put(iqueue, buf, len)) != 0) {
1680 fatal("%s: buffer error: %s",
1681 __func__, ssh_err(r));
1682 }
1683 }
1684 /* send oqueue to stdout */
1685 if (FD_ISSET(out, wset)) {
1686 len = write(out, sshbuf_ptr(oqueue), olen);
1687 if (len < 0) {
1688 error("write: %s", strerror(errno));
1689 sftp_server_cleanup_exit(1);
1690 } else if ((r = sshbuf_consume(oqueue, len)) != 0) {
1691 fatal("%s: buffer error: %s",
1692 __func__, ssh_err(r));
1693 }
1694 }
1695
1696 /*
1697 * Process requests from client if we can fit the results
1698 * into the output buffer, otherwise stop processing input
1699 * and let the output queue drain.
1700 */
1701 r = sshbuf_check_reserve(oqueue, SFTP_MAX_MSG_LENGTH);
1702 if (r == 0)
1703 process();
1704 else if (r != SSH_ERR_NO_BUFFER_SPACE)
1705 fatal("%s: sshbuf_check_reserve: %s",
1706 __func__, ssh_err(r));
1707 }
1708 }
1709