1 /* $OpenBSD: sftp-server.c,v 1.107 2015/08/20 22:32:42 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/param.h> /* MIN */
21 #include <sys/types.h>
22 #include <sys/stat.h>
23 #ifdef HAVE_SYS_TIME_H
24 # include <sys/time.h>
25 #endif
26 #ifdef HAVE_SYS_MOUNT_H
27 #include <sys/mount.h>
28 #endif
29 #ifdef HAVE_SYS_STATVFS_H
30 #include <sys/statvfs.h>
31 #endif
32 #ifdef HAVE_SYS_PRCTL_H
33 #include <sys/prctl.h>
34 #endif
35
36 #include <dirent.h>
37 #include <errno.h>
38 #include <fcntl.h>
39 #include <pwd.h>
40 #include <stdlib.h>
41 #include <stdio.h>
42 #include <string.h>
43 #include <time.h>
44 #include <unistd.h>
45 #include <stdarg.h>
46
47 #include "xmalloc.h"
48 #include "sshbuf.h"
49 #include "ssherr.h"
50 #include "log.h"
51 #include "misc.h"
52 #include "match.h"
53 #include "uidswap.h"
54
55 #include "sftp.h"
56 #include "sftp-common.h"
57
58 /* Our verbosity */
59 static LogLevel log_level = SYSLOG_LEVEL_ERROR;
60
61 /* Our client */
62 static struct passwd *pw = NULL;
63 static char *client_addr = NULL;
64
65 /* input and output queue */
66 struct sshbuf *iqueue;
67 struct sshbuf *oqueue;
68
69 /* Version of client */
70 static u_int version;
71
72 /* SSH2_FXP_INIT received */
73 static int init_done;
74
75 /* Disable writes */
76 static int readonly;
77
78 /* Requests that are allowed/denied */
79 static char *request_whitelist, *request_blacklist;
80
81 /* portable attributes, etc. */
82 typedef struct Stat Stat;
83
84 struct Stat {
85 char *name;
86 char *long_name;
87 Attrib attrib;
88 };
89
90 /* Packet handlers */
91 static void process_open(u_int32_t id);
92 static void process_close(u_int32_t id);
93 static void process_read(u_int32_t id);
94 static void process_write(u_int32_t id);
95 static void process_stat(u_int32_t id);
96 static void process_lstat(u_int32_t id);
97 static void process_fstat(u_int32_t id);
98 static void process_setstat(u_int32_t id);
99 static void process_fsetstat(u_int32_t id);
100 static void process_opendir(u_int32_t id);
101 static void process_readdir(u_int32_t id);
102 static void process_remove(u_int32_t id);
103 static void process_mkdir(u_int32_t id);
104 static void process_rmdir(u_int32_t id);
105 static void process_realpath(u_int32_t id);
106 static void process_rename(u_int32_t id);
107 static void process_readlink(u_int32_t id);
108 static void process_symlink(u_int32_t id);
109 static void process_extended_posix_rename(u_int32_t id);
110 static void process_extended_statvfs(u_int32_t id);
111 static void process_extended_fstatvfs(u_int32_t id);
112 static void process_extended_hardlink(u_int32_t id);
113 static void process_extended_fsync(u_int32_t id);
114 static void process_extended(u_int32_t id);
115
116 struct sftp_handler {
117 const char *name; /* user-visible name for fine-grained perms */
118 const char *ext_name; /* extended request name */
119 u_int type; /* packet type, for non extended packets */
120 void (*handler)(u_int32_t);
121 int does_write; /* if nonzero, banned for readonly mode */
122 };
123
124 struct sftp_handler handlers[] = {
125 /* NB. SSH2_FXP_OPEN does the readonly check in the handler itself */
126 { "open", NULL, SSH2_FXP_OPEN, process_open, 0 },
127 { "close", NULL, SSH2_FXP_CLOSE, process_close, 0 },
128 { "read", NULL, SSH2_FXP_READ, process_read, 0 },
129 { "write", NULL, SSH2_FXP_WRITE, process_write, 1 },
130 { "lstat", NULL, SSH2_FXP_LSTAT, process_lstat, 0 },
131 { "fstat", NULL, SSH2_FXP_FSTAT, process_fstat, 0 },
132 { "setstat", NULL, SSH2_FXP_SETSTAT, process_setstat, 1 },
133 { "fsetstat", NULL, SSH2_FXP_FSETSTAT, process_fsetstat, 1 },
134 { "opendir", NULL, SSH2_FXP_OPENDIR, process_opendir, 0 },
135 { "readdir", NULL, SSH2_FXP_READDIR, process_readdir, 0 },
136 { "remove", NULL, SSH2_FXP_REMOVE, process_remove, 1 },
137 { "mkdir", NULL, SSH2_FXP_MKDIR, process_mkdir, 1 },
138 { "rmdir", NULL, SSH2_FXP_RMDIR, process_rmdir, 1 },
139 { "realpath", NULL, SSH2_FXP_REALPATH, process_realpath, 0 },
140 { "stat", NULL, SSH2_FXP_STAT, process_stat, 0 },
141 { "rename", NULL, SSH2_FXP_RENAME, process_rename, 1 },
142 { "readlink", NULL, SSH2_FXP_READLINK, process_readlink, 0 },
143 { "symlink", NULL, SSH2_FXP_SYMLINK, process_symlink, 1 },
144 { NULL, NULL, 0, NULL, 0 }
145 };
146
147 /* SSH2_FXP_EXTENDED submessages */
148 struct sftp_handler extended_handlers[] = {
149 { "posix-rename", "posix-rename@openssh.com", 0,
150 process_extended_posix_rename, 1 },
151 { "statvfs", "statvfs@openssh.com", 0, process_extended_statvfs, 0 },
152 { "fstatvfs", "fstatvfs@openssh.com", 0, process_extended_fstatvfs, 0 },
153 { "hardlink", "hardlink@openssh.com", 0, process_extended_hardlink, 1 },
154 { "fsync", "fsync@openssh.com", 0, process_extended_fsync, 1 },
155 { NULL, NULL, 0, NULL, 0 }
156 };
157
158 static int
request_permitted(struct sftp_handler * h)159 request_permitted(struct sftp_handler *h)
160 {
161 char *result;
162
163 if (readonly && h->does_write) {
164 verbose("Refusing %s request in read-only mode", h->name);
165 return 0;
166 }
167 if (request_blacklist != NULL &&
168 ((result = match_list(h->name, request_blacklist, NULL))) != NULL) {
169 free(result);
170 verbose("Refusing blacklisted %s request", h->name);
171 return 0;
172 }
173 if (request_whitelist != NULL &&
174 ((result = match_list(h->name, request_whitelist, NULL))) != NULL) {
175 free(result);
176 debug2("Permitting whitelisted %s request", h->name);
177 return 1;
178 }
179 if (request_whitelist != NULL) {
180 verbose("Refusing non-whitelisted %s request", h->name);
181 return 0;
182 }
183 return 1;
184 }
185
186 static int
errno_to_portable(int unixerrno)187 errno_to_portable(int unixerrno)
188 {
189 int ret = 0;
190
191 switch (unixerrno) {
192 case 0:
193 ret = SSH2_FX_OK;
194 break;
195 case ENOENT:
196 case ENOTDIR:
197 case EBADF:
198 case ELOOP:
199 ret = SSH2_FX_NO_SUCH_FILE;
200 break;
201 case EPERM:
202 case EACCES:
203 case EFAULT:
204 ret = SSH2_FX_PERMISSION_DENIED;
205 break;
206 case ENAMETOOLONG:
207 case EINVAL:
208 ret = SSH2_FX_BAD_MESSAGE;
209 break;
210 case ENOSYS:
211 ret = SSH2_FX_OP_UNSUPPORTED;
212 break;
213 default:
214 ret = SSH2_FX_FAILURE;
215 break;
216 }
217 return ret;
218 }
219
220 static int
flags_from_portable(int pflags)221 flags_from_portable(int pflags)
222 {
223 int flags = 0;
224
225 if ((pflags & SSH2_FXF_READ) &&
226 (pflags & SSH2_FXF_WRITE)) {
227 flags = O_RDWR;
228 } else if (pflags & SSH2_FXF_READ) {
229 flags = O_RDONLY;
230 } else if (pflags & SSH2_FXF_WRITE) {
231 flags = O_WRONLY;
232 }
233 if (pflags & SSH2_FXF_APPEND)
234 flags |= O_APPEND;
235 if (pflags & SSH2_FXF_CREAT)
236 flags |= O_CREAT;
237 if (pflags & SSH2_FXF_TRUNC)
238 flags |= O_TRUNC;
239 if (pflags & SSH2_FXF_EXCL)
240 flags |= O_EXCL;
241 return flags;
242 }
243
244 static const char *
string_from_portable(int pflags)245 string_from_portable(int pflags)
246 {
247 static char ret[128];
248
249 *ret = '\0';
250
251 #define PAPPEND(str) { \
252 if (*ret != '\0') \
253 strlcat(ret, ",", sizeof(ret)); \
254 strlcat(ret, str, sizeof(ret)); \
255 }
256
257 if (pflags & SSH2_FXF_READ)
258 PAPPEND("READ")
259 if (pflags & SSH2_FXF_WRITE)
260 PAPPEND("WRITE")
261 if (pflags & SSH2_FXF_APPEND)
262 PAPPEND("APPEND")
263 if (pflags & SSH2_FXF_CREAT)
264 PAPPEND("CREATE")
265 if (pflags & SSH2_FXF_TRUNC)
266 PAPPEND("TRUNCATE")
267 if (pflags & SSH2_FXF_EXCL)
268 PAPPEND("EXCL")
269
270 return ret;
271 }
272
273 /* handle handles */
274
275 typedef struct Handle Handle;
276 struct Handle {
277 int use;
278 DIR *dirp;
279 int fd;
280 int flags;
281 char *name;
282 u_int64_t bytes_read, bytes_write;
283 int next_unused;
284 };
285
286 enum {
287 HANDLE_UNUSED,
288 HANDLE_DIR,
289 HANDLE_FILE
290 };
291
292 Handle *handles = NULL;
293 u_int num_handles = 0;
294 int first_unused_handle = -1;
295
handle_unused(int i)296 static void handle_unused(int i)
297 {
298 handles[i].use = HANDLE_UNUSED;
299 handles[i].next_unused = first_unused_handle;
300 first_unused_handle = i;
301 }
302
303 static int
handle_new(int use,const char * name,int fd,int flags,DIR * dirp)304 handle_new(int use, const char *name, int fd, int flags, DIR *dirp)
305 {
306 int i;
307
308 if (first_unused_handle == -1) {
309 if (num_handles + 1 <= num_handles)
310 return -1;
311 num_handles++;
312 handles = xreallocarray(handles, num_handles, sizeof(Handle));
313 handle_unused(num_handles - 1);
314 }
315
316 i = first_unused_handle;
317 first_unused_handle = handles[i].next_unused;
318
319 handles[i].use = use;
320 handles[i].dirp = dirp;
321 handles[i].fd = fd;
322 handles[i].flags = flags;
323 handles[i].name = xstrdup(name);
324 handles[i].bytes_read = handles[i].bytes_write = 0;
325
326 return i;
327 }
328
329 static int
handle_is_ok(int i,int type)330 handle_is_ok(int i, int type)
331 {
332 return i >= 0 && (u_int)i < num_handles && handles[i].use == type;
333 }
334
335 static int
handle_to_string(int handle,u_char ** stringp,int * hlenp)336 handle_to_string(int handle, u_char **stringp, int *hlenp)
337 {
338 if (stringp == NULL || hlenp == NULL)
339 return -1;
340 *stringp = xmalloc(sizeof(int32_t));
341 put_u32(*stringp, handle);
342 *hlenp = sizeof(int32_t);
343 return 0;
344 }
345
346 static int
handle_from_string(const u_char * handle,u_int hlen)347 handle_from_string(const u_char *handle, u_int hlen)
348 {
349 int val;
350
351 if (hlen != sizeof(int32_t))
352 return -1;
353 val = get_u32(handle);
354 if (handle_is_ok(val, HANDLE_FILE) ||
355 handle_is_ok(val, HANDLE_DIR))
356 return val;
357 return -1;
358 }
359
360 static char *
handle_to_name(int handle)361 handle_to_name(int handle)
362 {
363 if (handle_is_ok(handle, HANDLE_DIR)||
364 handle_is_ok(handle, HANDLE_FILE))
365 return handles[handle].name;
366 return NULL;
367 }
368
369 static DIR *
handle_to_dir(int handle)370 handle_to_dir(int handle)
371 {
372 if (handle_is_ok(handle, HANDLE_DIR))
373 return handles[handle].dirp;
374 return NULL;
375 }
376
377 static int
handle_to_fd(int handle)378 handle_to_fd(int handle)
379 {
380 if (handle_is_ok(handle, HANDLE_FILE))
381 return handles[handle].fd;
382 return -1;
383 }
384
385 static int
handle_to_flags(int handle)386 handle_to_flags(int handle)
387 {
388 if (handle_is_ok(handle, HANDLE_FILE))
389 return handles[handle].flags;
390 return 0;
391 }
392
393 static void
handle_update_read(int handle,ssize_t bytes)394 handle_update_read(int handle, ssize_t bytes)
395 {
396 if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
397 handles[handle].bytes_read += bytes;
398 }
399
400 static void
handle_update_write(int handle,ssize_t bytes)401 handle_update_write(int handle, ssize_t bytes)
402 {
403 if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
404 handles[handle].bytes_write += bytes;
405 }
406
407 static u_int64_t
handle_bytes_read(int handle)408 handle_bytes_read(int handle)
409 {
410 if (handle_is_ok(handle, HANDLE_FILE))
411 return (handles[handle].bytes_read);
412 return 0;
413 }
414
415 static u_int64_t
handle_bytes_write(int handle)416 handle_bytes_write(int handle)
417 {
418 if (handle_is_ok(handle, HANDLE_FILE))
419 return (handles[handle].bytes_write);
420 return 0;
421 }
422
423 static int
handle_close(int handle)424 handle_close(int handle)
425 {
426 int ret = -1;
427
428 if (handle_is_ok(handle, HANDLE_FILE)) {
429 ret = close(handles[handle].fd);
430 free(handles[handle].name);
431 handle_unused(handle);
432 } else if (handle_is_ok(handle, HANDLE_DIR)) {
433 ret = closedir(handles[handle].dirp);
434 free(handles[handle].name);
435 handle_unused(handle);
436 } else {
437 errno = ENOENT;
438 }
439 return ret;
440 }
441
442 static void
handle_log_close(int handle,char * emsg)443 handle_log_close(int handle, char *emsg)
444 {
445 if (handle_is_ok(handle, HANDLE_FILE)) {
446 logit("%s%sclose \"%s\" bytes read %llu written %llu",
447 emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
448 handle_to_name(handle),
449 (unsigned long long)handle_bytes_read(handle),
450 (unsigned long long)handle_bytes_write(handle));
451 } else {
452 logit("%s%sclosedir \"%s\"",
453 emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
454 handle_to_name(handle));
455 }
456 }
457
458 static void
handle_log_exit(void)459 handle_log_exit(void)
460 {
461 u_int i;
462
463 for (i = 0; i < num_handles; i++)
464 if (handles[i].use != HANDLE_UNUSED)
465 handle_log_close(i, "forced");
466 }
467
468 static int
get_handle(struct sshbuf * queue,int * hp)469 get_handle(struct sshbuf *queue, int *hp)
470 {
471 u_char *handle;
472 int r;
473 size_t hlen;
474
475 *hp = -1;
476 if ((r = sshbuf_get_string(queue, &handle, &hlen)) != 0)
477 return r;
478 if (hlen < 256)
479 *hp = handle_from_string(handle, hlen);
480 free(handle);
481 return 0;
482 }
483
484 /* send replies */
485
486 static void
send_msg(struct sshbuf * m)487 send_msg(struct sshbuf *m)
488 {
489 int r;
490
491 if ((r = sshbuf_put_stringb(oqueue, m)) != 0)
492 fatal("%s: buffer error: %s", __func__, ssh_err(r));
493 sshbuf_reset(m);
494 }
495
496 static const char *
status_to_message(u_int32_t status)497 status_to_message(u_int32_t status)
498 {
499 const char *status_messages[] = {
500 "Success", /* SSH_FX_OK */
501 "End of file", /* SSH_FX_EOF */
502 "No such file", /* SSH_FX_NO_SUCH_FILE */
503 "Permission denied", /* SSH_FX_PERMISSION_DENIED */
504 "Failure", /* SSH_FX_FAILURE */
505 "Bad message", /* SSH_FX_BAD_MESSAGE */
506 "No connection", /* SSH_FX_NO_CONNECTION */
507 "Connection lost", /* SSH_FX_CONNECTION_LOST */
508 "Operation unsupported", /* SSH_FX_OP_UNSUPPORTED */
509 "Unknown error" /* Others */
510 };
511 return (status_messages[MIN(status,SSH2_FX_MAX)]);
512 }
513
514 static void
send_status(u_int32_t id,u_int32_t status)515 send_status(u_int32_t id, u_int32_t status)
516 {
517 struct sshbuf *msg;
518 int r;
519
520 debug3("request %u: sent status %u", id, status);
521 if (log_level > SYSLOG_LEVEL_VERBOSE ||
522 (status != SSH2_FX_OK && status != SSH2_FX_EOF))
523 logit("sent status %s", status_to_message(status));
524 if ((msg = sshbuf_new()) == NULL)
525 fatal("%s: sshbuf_new failed", __func__);
526 if ((r = sshbuf_put_u8(msg, SSH2_FXP_STATUS)) != 0 ||
527 (r = sshbuf_put_u32(msg, id)) != 0 ||
528 (r = sshbuf_put_u32(msg, status)) != 0)
529 fatal("%s: buffer error: %s", __func__, ssh_err(r));
530 if (version >= 3) {
531 if ((r = sshbuf_put_cstring(msg,
532 status_to_message(status))) != 0 ||
533 (r = sshbuf_put_cstring(msg, "")) != 0)
534 fatal("%s: buffer error: %s", __func__, ssh_err(r));
535 }
536 send_msg(msg);
537 sshbuf_free(msg);
538 }
539 static void
send_data_or_handle(char type,u_int32_t id,const u_char * data,int dlen)540 send_data_or_handle(char type, u_int32_t id, const u_char *data, int dlen)
541 {
542 struct sshbuf *msg;
543 int r;
544
545 if ((msg = sshbuf_new()) == NULL)
546 fatal("%s: sshbuf_new failed", __func__);
547 if ((r = sshbuf_put_u8(msg, type)) != 0 ||
548 (r = sshbuf_put_u32(msg, id)) != 0 ||
549 (r = sshbuf_put_string(msg, data, dlen)) != 0)
550 fatal("%s: buffer error: %s", __func__, ssh_err(r));
551 send_msg(msg);
552 sshbuf_free(msg);
553 }
554
555 static void
send_data(u_int32_t id,const u_char * data,int dlen)556 send_data(u_int32_t id, const u_char *data, int dlen)
557 {
558 debug("request %u: sent data len %d", id, dlen);
559 send_data_or_handle(SSH2_FXP_DATA, id, data, dlen);
560 }
561
562 static void
send_handle(u_int32_t id,int handle)563 send_handle(u_int32_t id, int handle)
564 {
565 u_char *string;
566 int hlen;
567
568 handle_to_string(handle, &string, &hlen);
569 debug("request %u: sent handle handle %d", id, handle);
570 send_data_or_handle(SSH2_FXP_HANDLE, id, string, hlen);
571 free(string);
572 }
573
574 static void
send_names(u_int32_t id,int count,const Stat * stats)575 send_names(u_int32_t id, int count, const Stat *stats)
576 {
577 struct sshbuf *msg;
578 int i, r;
579
580 if ((msg = sshbuf_new()) == NULL)
581 fatal("%s: sshbuf_new failed", __func__);
582 if ((r = sshbuf_put_u8(msg, SSH2_FXP_NAME)) != 0 ||
583 (r = sshbuf_put_u32(msg, id)) != 0 ||
584 (r = sshbuf_put_u32(msg, count)) != 0)
585 fatal("%s: buffer error: %s", __func__, ssh_err(r));
586 debug("request %u: sent names count %d", id, count);
587 for (i = 0; i < count; i++) {
588 if ((r = sshbuf_put_cstring(msg, stats[i].name)) != 0 ||
589 (r = sshbuf_put_cstring(msg, stats[i].long_name)) != 0 ||
590 (r = encode_attrib(msg, &stats[i].attrib)) != 0)
591 fatal("%s: buffer error: %s", __func__, ssh_err(r));
592 }
593 send_msg(msg);
594 sshbuf_free(msg);
595 }
596
597 static void
send_attrib(u_int32_t id,const Attrib * a)598 send_attrib(u_int32_t id, const Attrib *a)
599 {
600 struct sshbuf *msg;
601 int r;
602
603 debug("request %u: sent attrib have 0x%x", id, a->flags);
604 if ((msg = sshbuf_new()) == NULL)
605 fatal("%s: sshbuf_new failed", __func__);
606 if ((r = sshbuf_put_u8(msg, SSH2_FXP_ATTRS)) != 0 ||
607 (r = sshbuf_put_u32(msg, id)) != 0 ||
608 (r = encode_attrib(msg, a)) != 0)
609 fatal("%s: buffer error: %s", __func__, ssh_err(r));
610 send_msg(msg);
611 sshbuf_free(msg);
612 }
613
614 static void
send_statvfs(u_int32_t id,struct statvfs * st)615 send_statvfs(u_int32_t id, struct statvfs *st)
616 {
617 struct sshbuf *msg;
618 u_int64_t flag;
619 int r;
620
621 flag = (st->f_flag & ST_RDONLY) ? SSH2_FXE_STATVFS_ST_RDONLY : 0;
622 flag |= (st->f_flag & ST_NOSUID) ? SSH2_FXE_STATVFS_ST_NOSUID : 0;
623
624 if ((msg = sshbuf_new()) == NULL)
625 fatal("%s: sshbuf_new failed", __func__);
626 if ((r = sshbuf_put_u8(msg, SSH2_FXP_EXTENDED_REPLY)) != 0 ||
627 (r = sshbuf_put_u32(msg, id)) != 0 ||
628 (r = sshbuf_put_u64(msg, st->f_bsize)) != 0 ||
629 (r = sshbuf_put_u64(msg, st->f_frsize)) != 0 ||
630 (r = sshbuf_put_u64(msg, st->f_blocks)) != 0 ||
631 (r = sshbuf_put_u64(msg, st->f_bfree)) != 0 ||
632 (r = sshbuf_put_u64(msg, st->f_bavail)) != 0 ||
633 (r = sshbuf_put_u64(msg, st->f_files)) != 0 ||
634 (r = sshbuf_put_u64(msg, st->f_ffree)) != 0 ||
635 (r = sshbuf_put_u64(msg, st->f_favail)) != 0 ||
636 (r = sshbuf_put_u64(msg, FSID_TO_ULONG(st->f_fsid))) != 0 ||
637 (r = sshbuf_put_u64(msg, flag)) != 0 ||
638 (r = sshbuf_put_u64(msg, st->f_namemax)) != 0)
639 fatal("%s: buffer error: %s", __func__, ssh_err(r));
640 send_msg(msg);
641 sshbuf_free(msg);
642 }
643
644 /* parse incoming */
645
646 static void
process_init(void)647 process_init(void)
648 {
649 struct sshbuf *msg;
650 int r;
651
652 if ((r = sshbuf_get_u32(iqueue, &version)) != 0)
653 fatal("%s: buffer error: %s", __func__, ssh_err(r));
654 verbose("received client version %u", version);
655 if ((msg = sshbuf_new()) == NULL)
656 fatal("%s: sshbuf_new failed", __func__);
657 if ((r = sshbuf_put_u8(msg, SSH2_FXP_VERSION)) != 0 ||
658 (r = sshbuf_put_u32(msg, SSH2_FILEXFER_VERSION)) != 0 ||
659 /* POSIX rename extension */
660 (r = sshbuf_put_cstring(msg, "posix-rename@openssh.com")) != 0 ||
661 (r = sshbuf_put_cstring(msg, "1")) != 0 || /* version */
662 /* statvfs extension */
663 (r = sshbuf_put_cstring(msg, "statvfs@openssh.com")) != 0 ||
664 (r = sshbuf_put_cstring(msg, "2")) != 0 || /* version */
665 /* fstatvfs extension */
666 (r = sshbuf_put_cstring(msg, "fstatvfs@openssh.com")) != 0 ||
667 (r = sshbuf_put_cstring(msg, "2")) != 0 || /* version */
668 /* hardlink extension */
669 (r = sshbuf_put_cstring(msg, "hardlink@openssh.com")) != 0 ||
670 (r = sshbuf_put_cstring(msg, "1")) != 0 || /* version */
671 /* fsync extension */
672 (r = sshbuf_put_cstring(msg, "fsync@openssh.com")) != 0 ||
673 (r = sshbuf_put_cstring(msg, "1")) != 0) /* version */
674 fatal("%s: buffer error: %s", __func__, ssh_err(r));
675 send_msg(msg);
676 sshbuf_free(msg);
677 }
678
679 static void
process_open(u_int32_t id)680 process_open(u_int32_t id)
681 {
682 u_int32_t pflags;
683 Attrib a;
684 char *name;
685 int r, handle, fd, flags, mode, status = SSH2_FX_FAILURE;
686
687 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
688 (r = sshbuf_get_u32(iqueue, &pflags)) != 0 || /* portable flags */
689 (r = decode_attrib(iqueue, &a)) != 0)
690 fatal("%s: buffer error: %s", __func__, ssh_err(r));
691
692 debug3("request %u: open flags %d", id, pflags);
693 flags = flags_from_portable(pflags);
694 mode = (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? a.perm : 0666;
695 logit("open \"%s\" flags %s mode 0%o",
696 name, string_from_portable(pflags), mode);
697 if (readonly &&
698 ((flags & O_ACCMODE) == O_WRONLY ||
699 (flags & O_ACCMODE) == O_RDWR)) {
700 verbose("Refusing open request in read-only mode");
701 status = SSH2_FX_PERMISSION_DENIED;
702 } else {
703 fd = open(name, flags, mode);
704 if (fd < 0) {
705 status = errno_to_portable(errno);
706 } else {
707 handle = handle_new(HANDLE_FILE, name, fd, flags, NULL);
708 if (handle < 0) {
709 close(fd);
710 } else {
711 send_handle(id, handle);
712 status = SSH2_FX_OK;
713 }
714 }
715 }
716 if (status != SSH2_FX_OK)
717 send_status(id, status);
718 free(name);
719 }
720
721 static void
process_close(u_int32_t id)722 process_close(u_int32_t id)
723 {
724 int r, handle, ret, status = SSH2_FX_FAILURE;
725
726 if ((r = get_handle(iqueue, &handle)) != 0)
727 fatal("%s: buffer error: %s", __func__, ssh_err(r));
728
729 debug3("request %u: close handle %u", id, handle);
730 handle_log_close(handle, NULL);
731 ret = handle_close(handle);
732 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
733 send_status(id, status);
734 }
735
736 static void
process_read(u_int32_t id)737 process_read(u_int32_t id)
738 {
739 u_char buf[64*1024];
740 u_int32_t len;
741 int r, handle, fd, ret, status = SSH2_FX_FAILURE;
742 u_int64_t off;
743
744 if ((r = get_handle(iqueue, &handle)) != 0 ||
745 (r = sshbuf_get_u64(iqueue, &off)) != 0 ||
746 (r = sshbuf_get_u32(iqueue, &len)) != 0)
747 fatal("%s: buffer error: %s", __func__, ssh_err(r));
748
749 debug("request %u: read \"%s\" (handle %d) off %llu len %d",
750 id, handle_to_name(handle), handle, (unsigned long long)off, len);
751 if (len > sizeof buf) {
752 len = sizeof buf;
753 debug2("read change len %d", len);
754 }
755 fd = handle_to_fd(handle);
756 if (fd >= 0) {
757 if (lseek(fd, off, SEEK_SET) < 0) {
758 error("process_read: seek failed");
759 status = errno_to_portable(errno);
760 } else {
761 ret = read(fd, buf, len);
762 if (ret < 0) {
763 status = errno_to_portable(errno);
764 } else if (ret == 0) {
765 status = SSH2_FX_EOF;
766 } else {
767 send_data(id, buf, ret);
768 status = SSH2_FX_OK;
769 handle_update_read(handle, ret);
770 }
771 }
772 }
773 if (status != SSH2_FX_OK)
774 send_status(id, status);
775 }
776
777 static void
process_write(u_int32_t id)778 process_write(u_int32_t id)
779 {
780 u_int64_t off;
781 size_t len;
782 int r, handle, fd, ret, status;
783 u_char *data;
784
785 if ((r = get_handle(iqueue, &handle)) != 0 ||
786 (r = sshbuf_get_u64(iqueue, &off)) != 0 ||
787 (r = sshbuf_get_string(iqueue, &data, &len)) != 0)
788 fatal("%s: buffer error: %s", __func__, ssh_err(r));
789
790 debug("request %u: write \"%s\" (handle %d) off %llu len %zu",
791 id, handle_to_name(handle), handle, (unsigned long long)off, len);
792 fd = handle_to_fd(handle);
793
794 if (fd < 0)
795 status = SSH2_FX_FAILURE;
796 else {
797 if (!(handle_to_flags(handle) & O_APPEND) &&
798 lseek(fd, off, SEEK_SET) < 0) {
799 status = errno_to_portable(errno);
800 error("process_write: seek failed");
801 } else {
802 /* XXX ATOMICIO ? */
803 ret = write(fd, data, len);
804 if (ret < 0) {
805 error("process_write: write failed");
806 status = errno_to_portable(errno);
807 } else if ((size_t)ret == len) {
808 status = SSH2_FX_OK;
809 handle_update_write(handle, ret);
810 } else {
811 debug2("nothing at all written");
812 status = SSH2_FX_FAILURE;
813 }
814 }
815 }
816 send_status(id, status);
817 free(data);
818 }
819
820 static void
process_do_stat(u_int32_t id,int do_lstat)821 process_do_stat(u_int32_t id, int do_lstat)
822 {
823 Attrib a;
824 struct stat st;
825 char *name;
826 int r, status = SSH2_FX_FAILURE;
827
828 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
829 fatal("%s: buffer error: %s", __func__, ssh_err(r));
830
831 debug3("request %u: %sstat", id, do_lstat ? "l" : "");
832 verbose("%sstat name \"%s\"", do_lstat ? "l" : "", name);
833 r = do_lstat ? lstat(name, &st) : stat(name, &st);
834 if (r < 0) {
835 status = errno_to_portable(errno);
836 } else {
837 stat_to_attrib(&st, &a);
838 send_attrib(id, &a);
839 status = SSH2_FX_OK;
840 }
841 if (status != SSH2_FX_OK)
842 send_status(id, status);
843 free(name);
844 }
845
846 static void
process_stat(u_int32_t id)847 process_stat(u_int32_t id)
848 {
849 process_do_stat(id, 0);
850 }
851
852 static void
process_lstat(u_int32_t id)853 process_lstat(u_int32_t id)
854 {
855 process_do_stat(id, 1);
856 }
857
858 static void
process_fstat(u_int32_t id)859 process_fstat(u_int32_t id)
860 {
861 Attrib a;
862 struct stat st;
863 int fd, r, handle, status = SSH2_FX_FAILURE;
864
865 if ((r = get_handle(iqueue, &handle)) != 0)
866 fatal("%s: buffer error: %s", __func__, ssh_err(r));
867 debug("request %u: fstat \"%s\" (handle %u)",
868 id, handle_to_name(handle), handle);
869 fd = handle_to_fd(handle);
870 if (fd >= 0) {
871 r = fstat(fd, &st);
872 if (r < 0) {
873 status = errno_to_portable(errno);
874 } else {
875 stat_to_attrib(&st, &a);
876 send_attrib(id, &a);
877 status = SSH2_FX_OK;
878 }
879 }
880 if (status != SSH2_FX_OK)
881 send_status(id, status);
882 }
883
884 static struct timeval *
attrib_to_tv(const Attrib * a)885 attrib_to_tv(const Attrib *a)
886 {
887 static struct timeval tv[2];
888
889 tv[0].tv_sec = a->atime;
890 tv[0].tv_usec = 0;
891 tv[1].tv_sec = a->mtime;
892 tv[1].tv_usec = 0;
893 return tv;
894 }
895
896 static void
process_setstat(u_int32_t id)897 process_setstat(u_int32_t id)
898 {
899 Attrib a;
900 char *name;
901 int r, status = SSH2_FX_OK;
902
903 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
904 (r = decode_attrib(iqueue, &a)) != 0)
905 fatal("%s: buffer error: %s", __func__, ssh_err(r));
906
907 debug("request %u: setstat name \"%s\"", id, name);
908 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) {
909 logit("set \"%s\" size %llu",
910 name, (unsigned long long)a.size);
911 r = truncate(name, a.size);
912 if (r == -1)
913 status = errno_to_portable(errno);
914 }
915 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
916 logit("set \"%s\" mode %04o", name, a.perm);
917 r = chmod(name, a.perm & 07777);
918 if (r == -1)
919 status = errno_to_portable(errno);
920 }
921 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
922 char buf[64];
923 time_t t = a.mtime;
924
925 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
926 localtime(&t));
927 logit("set \"%s\" modtime %s", name, buf);
928 r = utimes(name, attrib_to_tv(&a));
929 if (r == -1)
930 status = errno_to_portable(errno);
931 }
932 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) {
933 logit("set \"%s\" owner %lu group %lu", name,
934 (u_long)a.uid, (u_long)a.gid);
935 r = chown(name, a.uid, a.gid);
936 if (r == -1)
937 status = errno_to_portable(errno);
938 }
939 send_status(id, status);
940 free(name);
941 }
942
943 static void
process_fsetstat(u_int32_t id)944 process_fsetstat(u_int32_t id)
945 {
946 Attrib a;
947 int handle, fd, r;
948 int status = SSH2_FX_OK;
949
950 if ((r = get_handle(iqueue, &handle)) != 0 ||
951 (r = decode_attrib(iqueue, &a)) != 0)
952 fatal("%s: buffer error: %s", __func__, ssh_err(r));
953
954 debug("request %u: fsetstat handle %d", id, handle);
955 fd = handle_to_fd(handle);
956 if (fd < 0)
957 status = SSH2_FX_FAILURE;
958 else {
959 char *name = handle_to_name(handle);
960
961 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) {
962 logit("set \"%s\" size %llu",
963 name, (unsigned long long)a.size);
964 r = ftruncate(fd, a.size);
965 if (r == -1)
966 status = errno_to_portable(errno);
967 }
968 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
969 logit("set \"%s\" mode %04o", name, a.perm);
970 #ifdef HAVE_FCHMOD
971 r = fchmod(fd, a.perm & 07777);
972 #else
973 r = chmod(name, a.perm & 07777);
974 #endif
975 if (r == -1)
976 status = errno_to_portable(errno);
977 }
978 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
979 char buf[64];
980 time_t t = a.mtime;
981
982 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
983 localtime(&t));
984 logit("set \"%s\" modtime %s", name, buf);
985 #ifdef HAVE_FUTIMES
986 r = futimes(fd, attrib_to_tv(&a));
987 #else
988 r = utimes(name, attrib_to_tv(&a));
989 #endif
990 if (r == -1)
991 status = errno_to_portable(errno);
992 }
993 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) {
994 logit("set \"%s\" owner %lu group %lu", name,
995 (u_long)a.uid, (u_long)a.gid);
996 #ifdef HAVE_FCHOWN
997 r = fchown(fd, a.uid, a.gid);
998 #else
999 r = chown(name, a.uid, a.gid);
1000 #endif
1001 if (r == -1)
1002 status = errno_to_portable(errno);
1003 }
1004 }
1005 send_status(id, status);
1006 }
1007
1008 static void
process_opendir(u_int32_t id)1009 process_opendir(u_int32_t id)
1010 {
1011 DIR *dirp = NULL;
1012 char *path;
1013 int r, handle, status = SSH2_FX_FAILURE;
1014
1015 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1016 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1017
1018 debug3("request %u: opendir", id);
1019 logit("opendir \"%s\"", path);
1020 dirp = opendir(path);
1021 if (dirp == NULL) {
1022 status = errno_to_portable(errno);
1023 } else {
1024 handle = handle_new(HANDLE_DIR, path, 0, 0, dirp);
1025 if (handle < 0) {
1026 closedir(dirp);
1027 } else {
1028 send_handle(id, handle);
1029 status = SSH2_FX_OK;
1030 }
1031
1032 }
1033 if (status != SSH2_FX_OK)
1034 send_status(id, status);
1035 free(path);
1036 }
1037
1038 static void
process_readdir(u_int32_t id)1039 process_readdir(u_int32_t id)
1040 {
1041 DIR *dirp;
1042 struct dirent *dp;
1043 char *path;
1044 int r, handle;
1045
1046 if ((r = get_handle(iqueue, &handle)) != 0)
1047 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1048
1049 debug("request %u: readdir \"%s\" (handle %d)", id,
1050 handle_to_name(handle), handle);
1051 dirp = handle_to_dir(handle);
1052 path = handle_to_name(handle);
1053 if (dirp == NULL || path == NULL) {
1054 send_status(id, SSH2_FX_FAILURE);
1055 } else {
1056 struct stat st;
1057 char pathname[PATH_MAX];
1058 Stat *stats;
1059 int nstats = 10, count = 0, i;
1060
1061 stats = xcalloc(nstats, sizeof(Stat));
1062 while ((dp = readdir(dirp)) != NULL) {
1063 if (count >= nstats) {
1064 nstats *= 2;
1065 stats = xreallocarray(stats, nstats, sizeof(Stat));
1066 }
1067 /* XXX OVERFLOW ? */
1068 snprintf(pathname, sizeof pathname, "%s%s%s", path,
1069 strcmp(path, "/") ? "/" : "", dp->d_name);
1070 if (lstat(pathname, &st) < 0)
1071 continue;
1072 stat_to_attrib(&st, &(stats[count].attrib));
1073 stats[count].name = xstrdup(dp->d_name);
1074 stats[count].long_name = ls_file(dp->d_name, &st, 0, 0);
1075 count++;
1076 /* send up to 100 entries in one message */
1077 /* XXX check packet size instead */
1078 if (count == 100)
1079 break;
1080 }
1081 if (count > 0) {
1082 send_names(id, count, stats);
1083 for (i = 0; i < count; i++) {
1084 free(stats[i].name);
1085 free(stats[i].long_name);
1086 }
1087 } else {
1088 send_status(id, SSH2_FX_EOF);
1089 }
1090 free(stats);
1091 }
1092 }
1093
1094 static void
process_remove(u_int32_t id)1095 process_remove(u_int32_t id)
1096 {
1097 char *name;
1098 int r, status = SSH2_FX_FAILURE;
1099
1100 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
1101 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1102
1103 debug3("request %u: remove", id);
1104 logit("remove name \"%s\"", name);
1105 r = unlink(name);
1106 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1107 send_status(id, status);
1108 free(name);
1109 }
1110
1111 static void
process_mkdir(u_int32_t id)1112 process_mkdir(u_int32_t id)
1113 {
1114 Attrib a;
1115 char *name;
1116 int r, mode, status = SSH2_FX_FAILURE;
1117
1118 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
1119 (r = decode_attrib(iqueue, &a)) != 0)
1120 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1121
1122 mode = (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ?
1123 a.perm & 07777 : 0777;
1124 debug3("request %u: mkdir", id);
1125 logit("mkdir name \"%s\" mode 0%o", name, mode);
1126 r = mkdir(name, mode);
1127 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1128 send_status(id, status);
1129 free(name);
1130 }
1131
1132 static void
process_rmdir(u_int32_t id)1133 process_rmdir(u_int32_t id)
1134 {
1135 char *name;
1136 int r, status;
1137
1138 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
1139 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1140
1141 debug3("request %u: rmdir", id);
1142 logit("rmdir name \"%s\"", name);
1143 r = rmdir(name);
1144 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1145 send_status(id, status);
1146 free(name);
1147 }
1148
1149 static void
process_realpath(u_int32_t id)1150 process_realpath(u_int32_t id)
1151 {
1152 char resolvedname[PATH_MAX];
1153 char *path;
1154 int r;
1155
1156 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1157 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1158
1159 if (path[0] == '\0') {
1160 free(path);
1161 path = xstrdup(".");
1162 }
1163 debug3("request %u: realpath", id);
1164 verbose("realpath \"%s\"", path);
1165 if (realpath(path, resolvedname) == NULL) {
1166 send_status(id, errno_to_portable(errno));
1167 } else {
1168 Stat s;
1169 attrib_clear(&s.attrib);
1170 s.name = s.long_name = resolvedname;
1171 send_names(id, 1, &s);
1172 }
1173 free(path);
1174 }
1175
1176 static void
process_rename(u_int32_t id)1177 process_rename(u_int32_t id)
1178 {
1179 char *oldpath, *newpath;
1180 int r, status;
1181 struct stat sb;
1182
1183 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
1184 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
1185 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1186
1187 debug3("request %u: rename", id);
1188 logit("rename old \"%s\" new \"%s\"", oldpath, newpath);
1189 status = SSH2_FX_FAILURE;
1190 if (lstat(oldpath, &sb) == -1)
1191 status = errno_to_portable(errno);
1192 else if (S_ISREG(sb.st_mode)) {
1193 /* Race-free rename of regular files */
1194 if (link(oldpath, newpath) == -1) {
1195 if (errno == EOPNOTSUPP || errno == ENOSYS
1196 #ifdef EXDEV
1197 || errno == EXDEV
1198 #endif
1199 #ifdef LINK_OPNOTSUPP_ERRNO
1200 || errno == LINK_OPNOTSUPP_ERRNO
1201 #endif
1202 ) {
1203 struct stat st;
1204
1205 /*
1206 * fs doesn't support links, so fall back to
1207 * stat+rename. This is racy.
1208 */
1209 if (stat(newpath, &st) == -1) {
1210 if (rename(oldpath, newpath) == -1)
1211 status =
1212 errno_to_portable(errno);
1213 else
1214 status = SSH2_FX_OK;
1215 }
1216 } else {
1217 status = errno_to_portable(errno);
1218 }
1219 } else if (unlink(oldpath) == -1) {
1220 status = errno_to_portable(errno);
1221 /* clean spare link */
1222 unlink(newpath);
1223 } else
1224 status = SSH2_FX_OK;
1225 } else if (stat(newpath, &sb) == -1) {
1226 if (rename(oldpath, newpath) == -1)
1227 status = errno_to_portable(errno);
1228 else
1229 status = SSH2_FX_OK;
1230 }
1231 send_status(id, status);
1232 free(oldpath);
1233 free(newpath);
1234 }
1235
1236 static void
process_readlink(u_int32_t id)1237 process_readlink(u_int32_t id)
1238 {
1239 int r, len;
1240 char buf[PATH_MAX];
1241 char *path;
1242
1243 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1244 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1245
1246 debug3("request %u: readlink", id);
1247 verbose("readlink \"%s\"", path);
1248 if ((len = readlink(path, buf, sizeof(buf) - 1)) == -1)
1249 send_status(id, errno_to_portable(errno));
1250 else {
1251 Stat s;
1252
1253 buf[len] = '\0';
1254 attrib_clear(&s.attrib);
1255 s.name = s.long_name = buf;
1256 send_names(id, 1, &s);
1257 }
1258 free(path);
1259 }
1260
1261 static void
process_symlink(u_int32_t id)1262 process_symlink(u_int32_t id)
1263 {
1264 char *oldpath, *newpath;
1265 int r, status;
1266
1267 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
1268 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
1269 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1270
1271 debug3("request %u: symlink", id);
1272 logit("symlink old \"%s\" new \"%s\"", oldpath, newpath);
1273 /* this will fail if 'newpath' exists */
1274 r = symlink(oldpath, newpath);
1275 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1276 send_status(id, status);
1277 free(oldpath);
1278 free(newpath);
1279 }
1280
1281 static void
process_extended_posix_rename(u_int32_t id)1282 process_extended_posix_rename(u_int32_t id)
1283 {
1284 char *oldpath, *newpath;
1285 int r, status;
1286
1287 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
1288 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
1289 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1290
1291 debug3("request %u: posix-rename", id);
1292 logit("posix-rename old \"%s\" new \"%s\"", oldpath, newpath);
1293 r = rename(oldpath, newpath);
1294 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1295 send_status(id, status);
1296 free(oldpath);
1297 free(newpath);
1298 }
1299
1300 static void
process_extended_statvfs(u_int32_t id)1301 process_extended_statvfs(u_int32_t id)
1302 {
1303 char *path;
1304 struct statvfs st;
1305 int r;
1306
1307 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1308 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1309 debug3("request %u: statvfs", id);
1310 logit("statvfs \"%s\"", path);
1311
1312 if (statvfs(path, &st) != 0)
1313 send_status(id, errno_to_portable(errno));
1314 else
1315 send_statvfs(id, &st);
1316 free(path);
1317 }
1318
1319 static void
process_extended_fstatvfs(u_int32_t id)1320 process_extended_fstatvfs(u_int32_t id)
1321 {
1322 int r, handle, fd;
1323 struct statvfs st;
1324
1325 if ((r = get_handle(iqueue, &handle)) != 0)
1326 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1327 debug("request %u: fstatvfs \"%s\" (handle %u)",
1328 id, handle_to_name(handle), handle);
1329 if ((fd = handle_to_fd(handle)) < 0) {
1330 send_status(id, SSH2_FX_FAILURE);
1331 return;
1332 }
1333 if (fstatvfs(fd, &st) != 0)
1334 send_status(id, errno_to_portable(errno));
1335 else
1336 send_statvfs(id, &st);
1337 }
1338
1339 static void
process_extended_hardlink(u_int32_t id)1340 process_extended_hardlink(u_int32_t id)
1341 {
1342 char *oldpath, *newpath;
1343 int r, status;
1344
1345 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
1346 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
1347 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1348
1349 debug3("request %u: hardlink", id);
1350 logit("hardlink old \"%s\" new \"%s\"", oldpath, newpath);
1351 r = link(oldpath, newpath);
1352 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1353 send_status(id, status);
1354 free(oldpath);
1355 free(newpath);
1356 }
1357
1358 static void
process_extended_fsync(u_int32_t id)1359 process_extended_fsync(u_int32_t id)
1360 {
1361 int handle, fd, r, status = SSH2_FX_OP_UNSUPPORTED;
1362
1363 if ((r = get_handle(iqueue, &handle)) != 0)
1364 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1365 debug3("request %u: fsync (handle %u)", id, handle);
1366 verbose("fsync \"%s\"", handle_to_name(handle));
1367 if ((fd = handle_to_fd(handle)) < 0)
1368 status = SSH2_FX_NO_SUCH_FILE;
1369 else if (handle_is_ok(handle, HANDLE_FILE)) {
1370 r = fsync(fd);
1371 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1372 }
1373 send_status(id, status);
1374 }
1375
1376 static void
process_extended(u_int32_t id)1377 process_extended(u_int32_t id)
1378 {
1379 char *request;
1380 int i, r;
1381
1382 if ((r = sshbuf_get_cstring(iqueue, &request, NULL)) != 0)
1383 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1384 for (i = 0; extended_handlers[i].handler != NULL; i++) {
1385 if (strcmp(request, extended_handlers[i].ext_name) == 0) {
1386 if (!request_permitted(&extended_handlers[i]))
1387 send_status(id, SSH2_FX_PERMISSION_DENIED);
1388 else
1389 extended_handlers[i].handler(id);
1390 break;
1391 }
1392 }
1393 if (extended_handlers[i].handler == NULL) {
1394 error("Unknown extended request \"%.100s\"", request);
1395 send_status(id, SSH2_FX_OP_UNSUPPORTED); /* MUST */
1396 }
1397 free(request);
1398 }
1399
1400 /* stolen from ssh-agent */
1401
1402 static void
process(void)1403 process(void)
1404 {
1405 u_int msg_len;
1406 u_int buf_len;
1407 u_int consumed;
1408 u_char type;
1409 const u_char *cp;
1410 int i, r;
1411 u_int32_t id;
1412
1413 buf_len = sshbuf_len(iqueue);
1414 if (buf_len < 5)
1415 return; /* Incomplete message. */
1416 cp = sshbuf_ptr(iqueue);
1417 msg_len = get_u32(cp);
1418 if (msg_len > SFTP_MAX_MSG_LENGTH) {
1419 error("bad message from %s local user %s",
1420 client_addr, pw->pw_name);
1421 sftp_server_cleanup_exit(11);
1422 }
1423 if (buf_len < msg_len + 4)
1424 return;
1425 if ((r = sshbuf_consume(iqueue, 4)) != 0)
1426 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1427 buf_len -= 4;
1428 if ((r = sshbuf_get_u8(iqueue, &type)) != 0)
1429 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1430
1431 switch (type) {
1432 case SSH2_FXP_INIT:
1433 process_init();
1434 init_done = 1;
1435 break;
1436 case SSH2_FXP_EXTENDED:
1437 if (!init_done)
1438 fatal("Received extended request before init");
1439 if ((r = sshbuf_get_u32(iqueue, &id)) != 0)
1440 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1441 process_extended(id);
1442 break;
1443 default:
1444 if (!init_done)
1445 fatal("Received %u request before init", type);
1446 if ((r = sshbuf_get_u32(iqueue, &id)) != 0)
1447 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1448 for (i = 0; handlers[i].handler != NULL; i++) {
1449 if (type == handlers[i].type) {
1450 if (!request_permitted(&handlers[i])) {
1451 send_status(id,
1452 SSH2_FX_PERMISSION_DENIED);
1453 } else {
1454 handlers[i].handler(id);
1455 }
1456 break;
1457 }
1458 }
1459 if (handlers[i].handler == NULL)
1460 error("Unknown message %u", type);
1461 }
1462 /* discard the remaining bytes from the current packet */
1463 if (buf_len < sshbuf_len(iqueue)) {
1464 error("iqueue grew unexpectedly");
1465 sftp_server_cleanup_exit(255);
1466 }
1467 consumed = buf_len - sshbuf_len(iqueue);
1468 if (msg_len < consumed) {
1469 error("msg_len %u < consumed %u", msg_len, consumed);
1470 sftp_server_cleanup_exit(255);
1471 }
1472 if (msg_len > consumed &&
1473 (r = sshbuf_consume(iqueue, msg_len - consumed)) != 0)
1474 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1475 }
1476
1477 /* Cleanup handler that logs active handles upon normal exit */
1478 void
sftp_server_cleanup_exit(int i)1479 sftp_server_cleanup_exit(int i)
1480 {
1481 if (pw != NULL && client_addr != NULL) {
1482 handle_log_exit();
1483 logit("session closed for local user %s from [%s]",
1484 pw->pw_name, client_addr);
1485 }
1486 _exit(i);
1487 }
1488
1489 static void
sftp_server_usage(void)1490 sftp_server_usage(void)
1491 {
1492 extern char *__progname;
1493
1494 fprintf(stderr,
1495 "usage: %s [-ehR] [-d start_directory] [-f log_facility] "
1496 "[-l log_level]\n\t[-P blacklisted_requests] "
1497 "[-p whitelisted_requests] [-u umask]\n"
1498 " %s -Q protocol_feature\n",
1499 __progname, __progname);
1500 exit(1);
1501 }
1502
1503 int
sftp_server_main(int argc,char ** argv,struct passwd * user_pw)1504 sftp_server_main(int argc, char **argv, struct passwd *user_pw)
1505 {
1506 fd_set *rset, *wset;
1507 int i, r, in, out, max, ch, skipargs = 0, log_stderr = 0;
1508 ssize_t len, olen, set_size;
1509 SyslogFacility log_facility = SYSLOG_FACILITY_AUTH;
1510 char *cp, *homedir = NULL, buf[4*4096];
1511 long mask;
1512
1513 extern char *optarg;
1514 extern char *__progname;
1515
1516 __progname = ssh_get_progname(argv[0]);
1517 log_init(__progname, log_level, log_facility, log_stderr);
1518
1519 pw = pwcopy(user_pw);
1520
1521 while (!skipargs && (ch = getopt(argc, argv,
1522 "d:f:l:P:p:Q:u:cehR")) != -1) {
1523 switch (ch) {
1524 case 'Q':
1525 if (strcasecmp(optarg, "requests") != 0) {
1526 fprintf(stderr, "Invalid query type\n");
1527 exit(1);
1528 }
1529 for (i = 0; handlers[i].handler != NULL; i++)
1530 printf("%s\n", handlers[i].name);
1531 for (i = 0; extended_handlers[i].handler != NULL; i++)
1532 printf("%s\n", extended_handlers[i].name);
1533 exit(0);
1534 break;
1535 case 'R':
1536 readonly = 1;
1537 break;
1538 case 'c':
1539 /*
1540 * Ignore all arguments if we are invoked as a
1541 * shell using "sftp-server -c command"
1542 */
1543 skipargs = 1;
1544 break;
1545 case 'e':
1546 log_stderr = 1;
1547 break;
1548 case 'l':
1549 log_level = log_level_number(optarg);
1550 if (log_level == SYSLOG_LEVEL_NOT_SET)
1551 error("Invalid log level \"%s\"", optarg);
1552 break;
1553 case 'f':
1554 log_facility = log_facility_number(optarg);
1555 if (log_facility == SYSLOG_FACILITY_NOT_SET)
1556 error("Invalid log facility \"%s\"", optarg);
1557 break;
1558 case 'd':
1559 cp = tilde_expand_filename(optarg, user_pw->pw_uid);
1560 homedir = percent_expand(cp, "d", user_pw->pw_dir,
1561 "u", user_pw->pw_name, (char *)NULL);
1562 free(cp);
1563 break;
1564 case 'p':
1565 if (request_whitelist != NULL)
1566 fatal("Permitted requests already set");
1567 request_whitelist = xstrdup(optarg);
1568 break;
1569 case 'P':
1570 if (request_blacklist != NULL)
1571 fatal("Refused requests already set");
1572 request_blacklist = xstrdup(optarg);
1573 break;
1574 case 'u':
1575 errno = 0;
1576 mask = strtol(optarg, &cp, 8);
1577 if (mask < 0 || mask > 0777 || *cp != '\0' ||
1578 cp == optarg || (mask == 0 && errno != 0))
1579 fatal("Invalid umask \"%s\"", optarg);
1580 (void)umask((mode_t)mask);
1581 break;
1582 case 'h':
1583 default:
1584 sftp_server_usage();
1585 }
1586 }
1587
1588 log_init(__progname, log_level, log_facility, log_stderr);
1589
1590 #if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
1591 /*
1592 * On Linux, we should try to avoid making /proc/self/{mem,maps}
1593 * available to the user so that sftp access doesn't automatically
1594 * imply arbitrary code execution access that will break
1595 * restricted configurations.
1596 */
1597 if (prctl(PR_SET_DUMPABLE, 0) != 0)
1598 fatal("unable to make the process undumpable");
1599 #endif /* defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE) */
1600
1601 if ((cp = getenv("SSH_CONNECTION")) != NULL) {
1602 client_addr = xstrdup(cp);
1603 if ((cp = strchr(client_addr, ' ')) == NULL) {
1604 error("Malformed SSH_CONNECTION variable: \"%s\"",
1605 getenv("SSH_CONNECTION"));
1606 sftp_server_cleanup_exit(255);
1607 }
1608 *cp = '\0';
1609 } else
1610 client_addr = xstrdup("UNKNOWN");
1611
1612 logit("session opened for local user %s from [%s]",
1613 pw->pw_name, client_addr);
1614
1615 in = STDIN_FILENO;
1616 out = STDOUT_FILENO;
1617
1618 #ifdef HAVE_CYGWIN
1619 setmode(in, O_BINARY);
1620 setmode(out, O_BINARY);
1621 #endif
1622
1623 max = 0;
1624 if (in > max)
1625 max = in;
1626 if (out > max)
1627 max = out;
1628
1629 if ((iqueue = sshbuf_new()) == NULL)
1630 fatal("%s: sshbuf_new failed", __func__);
1631 if ((oqueue = sshbuf_new()) == NULL)
1632 fatal("%s: sshbuf_new failed", __func__);
1633
1634 set_size = howmany(max + 1, NFDBITS) * sizeof(fd_mask);
1635 rset = xmalloc(set_size);
1636 wset = xmalloc(set_size);
1637
1638 if (homedir != NULL) {
1639 if (chdir(homedir) != 0) {
1640 error("chdir to \"%s\" failed: %s", homedir,
1641 strerror(errno));
1642 }
1643 }
1644
1645 for (;;) {
1646 memset(rset, 0, set_size);
1647 memset(wset, 0, set_size);
1648
1649 /*
1650 * Ensure that we can read a full buffer and handle
1651 * the worst-case length packet it can generate,
1652 * otherwise apply backpressure by stopping reads.
1653 */
1654 if ((r = sshbuf_check_reserve(iqueue, sizeof(buf))) == 0 &&
1655 (r = sshbuf_check_reserve(oqueue,
1656 SFTP_MAX_MSG_LENGTH)) == 0)
1657 FD_SET(in, rset);
1658 else if (r != SSH_ERR_NO_BUFFER_SPACE)
1659 fatal("%s: sshbuf_check_reserve failed: %s",
1660 __func__, ssh_err(r));
1661
1662 olen = sshbuf_len(oqueue);
1663 if (olen > 0)
1664 FD_SET(out, wset);
1665
1666 if (select(max+1, rset, wset, NULL, NULL) < 0) {
1667 if (errno == EINTR)
1668 continue;
1669 error("select: %s", strerror(errno));
1670 sftp_server_cleanup_exit(2);
1671 }
1672
1673 /* copy stdin to iqueue */
1674 if (FD_ISSET(in, rset)) {
1675 len = read(in, buf, sizeof buf);
1676 if (len == 0) {
1677 debug("read eof");
1678 sftp_server_cleanup_exit(0);
1679 } else if (len < 0) {
1680 error("read: %s", strerror(errno));
1681 sftp_server_cleanup_exit(1);
1682 } else if ((r = sshbuf_put(iqueue, buf, len)) != 0) {
1683 fatal("%s: buffer error: %s",
1684 __func__, ssh_err(r));
1685 }
1686 }
1687 /* send oqueue to stdout */
1688 if (FD_ISSET(out, wset)) {
1689 len = write(out, sshbuf_ptr(oqueue), olen);
1690 if (len < 0) {
1691 error("write: %s", strerror(errno));
1692 sftp_server_cleanup_exit(1);
1693 } else if ((r = sshbuf_consume(oqueue, len)) != 0) {
1694 fatal("%s: buffer error: %s",
1695 __func__, ssh_err(r));
1696 }
1697 }
1698
1699 /*
1700 * Process requests from client if we can fit the results
1701 * into the output buffer, otherwise stop processing input
1702 * and let the output queue drain.
1703 */
1704 r = sshbuf_check_reserve(oqueue, SFTP_MAX_MSG_LENGTH);
1705 if (r == 0)
1706 process();
1707 else if (r != SSH_ERR_NO_BUFFER_SPACE)
1708 fatal("%s: sshbuf_check_reserve: %s",
1709 __func__, ssh_err(r));
1710 }
1711 }
1712