1 /* $OpenBSD: sftp-server.c,v 1.117 2019/07/05 04:55:40 djm 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 char *sftp_realpath(const char *, char *); /* sftp-realpath.c */
55
56 /* Our verbosity */
57 static LogLevel log_level = SYSLOG_LEVEL_ERROR;
58
59 /* Our client */
60 static struct passwd *pw = NULL;
61 static char *client_addr = NULL;
62
63 /* input and output queue */
64 struct sshbuf *iqueue;
65 struct sshbuf *oqueue;
66
67 /* Version of client */
68 static u_int version;
69
70 /* SSH2_FXP_INIT received */
71 static int init_done;
72
73 /* Disable writes */
74 static int readonly;
75
76 /* Requests that are allowed/denied */
77 static char *request_whitelist, *request_blacklist;
78
79 /* portable attributes, etc. */
80 typedef struct Stat Stat;
81
82 struct Stat {
83 char *name;
84 char *long_name;
85 Attrib attrib;
86 };
87
88 /* Packet handlers */
89 static void process_open(u_int32_t id);
90 static void process_close(u_int32_t id);
91 static void process_read(u_int32_t id);
92 static void process_write(u_int32_t id);
93 static void process_stat(u_int32_t id);
94 static void process_lstat(u_int32_t id);
95 static void process_fstat(u_int32_t id);
96 static void process_setstat(u_int32_t id);
97 static void process_fsetstat(u_int32_t id);
98 static void process_opendir(u_int32_t id);
99 static void process_readdir(u_int32_t id);
100 static void process_remove(u_int32_t id);
101 static void process_mkdir(u_int32_t id);
102 static void process_rmdir(u_int32_t id);
103 static void process_realpath(u_int32_t id);
104 static void process_rename(u_int32_t id);
105 static void process_readlink(u_int32_t id);
106 static void process_symlink(u_int32_t id);
107 static void process_extended_posix_rename(u_int32_t id);
108 static void process_extended_statvfs(u_int32_t id);
109 static void process_extended_fstatvfs(u_int32_t id);
110 static void process_extended_hardlink(u_int32_t id);
111 static void process_extended_fsync(u_int32_t id);
112 static void process_extended_lsetstat(u_int32_t id);
113 static void process_extended(u_int32_t id);
114
115 struct sftp_handler {
116 const char *name; /* user-visible name for fine-grained perms */
117 const char *ext_name; /* extended request name */
118 u_int type; /* packet type, for non extended packets */
119 void (*handler)(u_int32_t);
120 int does_write; /* if nonzero, banned for readonly mode */
121 };
122
123 static const struct sftp_handler handlers[] = {
124 /* NB. SSH2_FXP_OPEN does the readonly check in the handler itself */
125 { "open", NULL, SSH2_FXP_OPEN, process_open, 0 },
126 { "close", NULL, SSH2_FXP_CLOSE, process_close, 0 },
127 { "read", NULL, SSH2_FXP_READ, process_read, 0 },
128 { "write", NULL, SSH2_FXP_WRITE, process_write, 1 },
129 { "lstat", NULL, SSH2_FXP_LSTAT, process_lstat, 0 },
130 { "fstat", NULL, SSH2_FXP_FSTAT, process_fstat, 0 },
131 { "setstat", NULL, SSH2_FXP_SETSTAT, process_setstat, 1 },
132 { "fsetstat", NULL, SSH2_FXP_FSETSTAT, process_fsetstat, 1 },
133 { "opendir", NULL, SSH2_FXP_OPENDIR, process_opendir, 0 },
134 { "readdir", NULL, SSH2_FXP_READDIR, process_readdir, 0 },
135 { "remove", NULL, SSH2_FXP_REMOVE, process_remove, 1 },
136 { "mkdir", NULL, SSH2_FXP_MKDIR, process_mkdir, 1 },
137 { "rmdir", NULL, SSH2_FXP_RMDIR, process_rmdir, 1 },
138 { "realpath", NULL, SSH2_FXP_REALPATH, process_realpath, 0 },
139 { "stat", NULL, SSH2_FXP_STAT, process_stat, 0 },
140 { "rename", NULL, SSH2_FXP_RENAME, process_rename, 1 },
141 { "readlink", NULL, SSH2_FXP_READLINK, process_readlink, 0 },
142 { "symlink", NULL, SSH2_FXP_SYMLINK, process_symlink, 1 },
143 { NULL, NULL, 0, NULL, 0 }
144 };
145
146 /* SSH2_FXP_EXTENDED submessages */
147 static const struct sftp_handler extended_handlers[] = {
148 { "posix-rename", "posix-rename@openssh.com", 0,
149 process_extended_posix_rename, 1 },
150 { "statvfs", "statvfs@openssh.com", 0, process_extended_statvfs, 0 },
151 { "fstatvfs", "fstatvfs@openssh.com", 0, process_extended_fstatvfs, 0 },
152 { "hardlink", "hardlink@openssh.com", 0, process_extended_hardlink, 1 },
153 { "fsync", "fsync@openssh.com", 0, process_extended_fsync, 1 },
154 { "lsetstat", "lsetstat@openssh.com", 0, process_extended_lsetstat, 1 },
155 { NULL, NULL, 0, NULL, 0 }
156 };
157
158 static int
request_permitted(const struct sftp_handler * h)159 request_permitted(const 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 static Handle *handles = NULL;
293 static u_int num_handles = 0;
294 static 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[MINIMUM(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 (r = sshbuf_put_cstring(msg, "lsetstat@openssh.com")) != 0 ||
675 (r = sshbuf_put_cstring(msg, "1")) != 0) /* version */
676 fatal("%s: buffer error: %s", __func__, ssh_err(r));
677 send_msg(msg);
678 sshbuf_free(msg);
679 }
680
681 static void
process_open(u_int32_t id)682 process_open(u_int32_t id)
683 {
684 u_int32_t pflags;
685 Attrib a;
686 char *name;
687 int r, handle, fd, flags, mode, status = SSH2_FX_FAILURE;
688
689 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
690 (r = sshbuf_get_u32(iqueue, &pflags)) != 0 || /* portable flags */
691 (r = decode_attrib(iqueue, &a)) != 0)
692 fatal("%s: buffer error: %s", __func__, ssh_err(r));
693
694 debug3("request %u: open flags %d", id, pflags);
695 flags = flags_from_portable(pflags);
696 mode = (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? a.perm : 0666;
697 logit("open \"%s\" flags %s mode 0%o",
698 name, string_from_portable(pflags), mode);
699 if (readonly &&
700 ((flags & O_ACCMODE) != O_RDONLY ||
701 (flags & (O_CREAT|O_TRUNC)) != 0)) {
702 verbose("Refusing open request in read-only mode");
703 status = SSH2_FX_PERMISSION_DENIED;
704 } else {
705 fd = open(name, flags, mode);
706 if (fd == -1) {
707 status = errno_to_portable(errno);
708 } else {
709 handle = handle_new(HANDLE_FILE, name, fd, flags, NULL);
710 if (handle < 0) {
711 close(fd);
712 } else {
713 send_handle(id, handle);
714 status = SSH2_FX_OK;
715 }
716 }
717 }
718 if (status != SSH2_FX_OK)
719 send_status(id, status);
720 free(name);
721 }
722
723 static void
process_close(u_int32_t id)724 process_close(u_int32_t id)
725 {
726 int r, handle, ret, status = SSH2_FX_FAILURE;
727
728 if ((r = get_handle(iqueue, &handle)) != 0)
729 fatal("%s: buffer error: %s", __func__, ssh_err(r));
730
731 debug3("request %u: close handle %u", id, handle);
732 handle_log_close(handle, NULL);
733 ret = handle_close(handle);
734 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
735 send_status(id, status);
736 }
737
738 static void
process_read(u_int32_t id)739 process_read(u_int32_t id)
740 {
741 u_char buf[64*1024];
742 u_int32_t len;
743 int r, handle, fd, ret, status = SSH2_FX_FAILURE;
744 u_int64_t off;
745
746 if ((r = get_handle(iqueue, &handle)) != 0 ||
747 (r = sshbuf_get_u64(iqueue, &off)) != 0 ||
748 (r = sshbuf_get_u32(iqueue, &len)) != 0)
749 fatal("%s: buffer error: %s", __func__, ssh_err(r));
750
751 debug("request %u: read \"%s\" (handle %d) off %llu len %d",
752 id, handle_to_name(handle), handle, (unsigned long long)off, len);
753 if (len > sizeof buf) {
754 len = sizeof buf;
755 debug2("read change len %d", len);
756 }
757 fd = handle_to_fd(handle);
758 if (fd >= 0) {
759 if (lseek(fd, off, SEEK_SET) == -1) {
760 error("process_read: seek failed");
761 status = errno_to_portable(errno);
762 } else {
763 ret = read(fd, buf, len);
764 if (ret == -1) {
765 status = errno_to_portable(errno);
766 } else if (ret == 0) {
767 status = SSH2_FX_EOF;
768 } else {
769 send_data(id, buf, ret);
770 status = SSH2_FX_OK;
771 handle_update_read(handle, ret);
772 }
773 }
774 }
775 if (status != SSH2_FX_OK)
776 send_status(id, status);
777 }
778
779 static void
process_write(u_int32_t id)780 process_write(u_int32_t id)
781 {
782 u_int64_t off;
783 size_t len;
784 int r, handle, fd, ret, status;
785 u_char *data;
786
787 if ((r = get_handle(iqueue, &handle)) != 0 ||
788 (r = sshbuf_get_u64(iqueue, &off)) != 0 ||
789 (r = sshbuf_get_string(iqueue, &data, &len)) != 0)
790 fatal("%s: buffer error: %s", __func__, ssh_err(r));
791
792 debug("request %u: write \"%s\" (handle %d) off %llu len %zu",
793 id, handle_to_name(handle), handle, (unsigned long long)off, len);
794 fd = handle_to_fd(handle);
795
796 if (fd < 0)
797 status = SSH2_FX_FAILURE;
798 else {
799 if (!(handle_to_flags(handle) & O_APPEND) &&
800 lseek(fd, off, SEEK_SET) == -1) {
801 status = errno_to_portable(errno);
802 error("process_write: seek failed");
803 } else {
804 /* XXX ATOMICIO ? */
805 ret = write(fd, data, len);
806 if (ret == -1) {
807 error("process_write: write failed");
808 status = errno_to_portable(errno);
809 } else if ((size_t)ret == len) {
810 status = SSH2_FX_OK;
811 handle_update_write(handle, ret);
812 } else {
813 debug2("nothing at all written");
814 status = SSH2_FX_FAILURE;
815 }
816 }
817 }
818 send_status(id, status);
819 free(data);
820 }
821
822 static void
process_do_stat(u_int32_t id,int do_lstat)823 process_do_stat(u_int32_t id, int do_lstat)
824 {
825 Attrib a;
826 struct stat st;
827 char *name;
828 int r, status = SSH2_FX_FAILURE;
829
830 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
831 fatal("%s: buffer error: %s", __func__, ssh_err(r));
832
833 debug3("request %u: %sstat", id, do_lstat ? "l" : "");
834 verbose("%sstat name \"%s\"", do_lstat ? "l" : "", name);
835 r = do_lstat ? lstat(name, &st) : stat(name, &st);
836 if (r == -1) {
837 status = errno_to_portable(errno);
838 } else {
839 stat_to_attrib(&st, &a);
840 send_attrib(id, &a);
841 status = SSH2_FX_OK;
842 }
843 if (status != SSH2_FX_OK)
844 send_status(id, status);
845 free(name);
846 }
847
848 static void
process_stat(u_int32_t id)849 process_stat(u_int32_t id)
850 {
851 process_do_stat(id, 0);
852 }
853
854 static void
process_lstat(u_int32_t id)855 process_lstat(u_int32_t id)
856 {
857 process_do_stat(id, 1);
858 }
859
860 static void
process_fstat(u_int32_t id)861 process_fstat(u_int32_t id)
862 {
863 Attrib a;
864 struct stat st;
865 int fd, r, handle, status = SSH2_FX_FAILURE;
866
867 if ((r = get_handle(iqueue, &handle)) != 0)
868 fatal("%s: buffer error: %s", __func__, ssh_err(r));
869 debug("request %u: fstat \"%s\" (handle %u)",
870 id, handle_to_name(handle), handle);
871 fd = handle_to_fd(handle);
872 if (fd >= 0) {
873 r = fstat(fd, &st);
874 if (r == -1) {
875 status = errno_to_portable(errno);
876 } else {
877 stat_to_attrib(&st, &a);
878 send_attrib(id, &a);
879 status = SSH2_FX_OK;
880 }
881 }
882 if (status != SSH2_FX_OK)
883 send_status(id, status);
884 }
885
886 static struct timeval *
attrib_to_tv(const Attrib * a)887 attrib_to_tv(const Attrib *a)
888 {
889 static struct timeval tv[2];
890
891 tv[0].tv_sec = a->atime;
892 tv[0].tv_usec = 0;
893 tv[1].tv_sec = a->mtime;
894 tv[1].tv_usec = 0;
895 return tv;
896 }
897
898 static struct timespec *
attrib_to_ts(const Attrib * a)899 attrib_to_ts(const Attrib *a)
900 {
901 static struct timespec ts[2];
902
903 ts[0].tv_sec = a->atime;
904 ts[0].tv_nsec = 0;
905 ts[1].tv_sec = a->mtime;
906 ts[1].tv_nsec = 0;
907 return ts;
908 }
909
910 static void
process_setstat(u_int32_t id)911 process_setstat(u_int32_t id)
912 {
913 Attrib a;
914 char *name;
915 int r, status = SSH2_FX_OK;
916
917 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
918 (r = decode_attrib(iqueue, &a)) != 0)
919 fatal("%s: buffer error: %s", __func__, ssh_err(r));
920
921 debug("request %u: setstat name \"%s\"", id, name);
922 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) {
923 logit("set \"%s\" size %llu",
924 name, (unsigned long long)a.size);
925 r = truncate(name, a.size);
926 if (r == -1)
927 status = errno_to_portable(errno);
928 }
929 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
930 logit("set \"%s\" mode %04o", name, a.perm);
931 r = chmod(name, a.perm & 07777);
932 if (r == -1)
933 status = errno_to_portable(errno);
934 }
935 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
936 char buf[64];
937 time_t t = a.mtime;
938
939 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
940 localtime(&t));
941 logit("set \"%s\" modtime %s", name, buf);
942 r = utimes(name, attrib_to_tv(&a));
943 if (r == -1)
944 status = errno_to_portable(errno);
945 }
946 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) {
947 logit("set \"%s\" owner %lu group %lu", name,
948 (u_long)a.uid, (u_long)a.gid);
949 r = chown(name, a.uid, a.gid);
950 if (r == -1)
951 status = errno_to_portable(errno);
952 }
953 send_status(id, status);
954 free(name);
955 }
956
957 static void
process_fsetstat(u_int32_t id)958 process_fsetstat(u_int32_t id)
959 {
960 Attrib a;
961 int handle, fd, r;
962 int status = SSH2_FX_OK;
963
964 if ((r = get_handle(iqueue, &handle)) != 0 ||
965 (r = decode_attrib(iqueue, &a)) != 0)
966 fatal("%s: buffer error: %s", __func__, ssh_err(r));
967
968 debug("request %u: fsetstat handle %d", id, handle);
969 fd = handle_to_fd(handle);
970 if (fd < 0)
971 status = SSH2_FX_FAILURE;
972 else {
973 char *name = handle_to_name(handle);
974
975 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) {
976 logit("set \"%s\" size %llu",
977 name, (unsigned long long)a.size);
978 r = ftruncate(fd, a.size);
979 if (r == -1)
980 status = errno_to_portable(errno);
981 }
982 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
983 logit("set \"%s\" mode %04o", name, a.perm);
984 #ifdef HAVE_FCHMOD
985 r = fchmod(fd, a.perm & 07777);
986 #else
987 r = chmod(name, a.perm & 07777);
988 #endif
989 if (r == -1)
990 status = errno_to_portable(errno);
991 }
992 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
993 char buf[64];
994 time_t t = a.mtime;
995
996 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
997 localtime(&t));
998 logit("set \"%s\" modtime %s", name, buf);
999 #ifdef HAVE_FUTIMES
1000 r = futimes(fd, attrib_to_tv(&a));
1001 #else
1002 r = utimes(name, attrib_to_tv(&a));
1003 #endif
1004 if (r == -1)
1005 status = errno_to_portable(errno);
1006 }
1007 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) {
1008 logit("set \"%s\" owner %lu group %lu", name,
1009 (u_long)a.uid, (u_long)a.gid);
1010 #ifdef HAVE_FCHOWN
1011 r = fchown(fd, a.uid, a.gid);
1012 #else
1013 r = chown(name, a.uid, a.gid);
1014 #endif
1015 if (r == -1)
1016 status = errno_to_portable(errno);
1017 }
1018 }
1019 send_status(id, status);
1020 }
1021
1022 static void
process_opendir(u_int32_t id)1023 process_opendir(u_int32_t id)
1024 {
1025 DIR *dirp = NULL;
1026 char *path;
1027 int r, handle, status = SSH2_FX_FAILURE;
1028
1029 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1030 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1031
1032 debug3("request %u: opendir", id);
1033 logit("opendir \"%s\"", path);
1034 dirp = opendir(path);
1035 if (dirp == NULL) {
1036 status = errno_to_portable(errno);
1037 } else {
1038 handle = handle_new(HANDLE_DIR, path, 0, 0, dirp);
1039 if (handle < 0) {
1040 closedir(dirp);
1041 } else {
1042 send_handle(id, handle);
1043 status = SSH2_FX_OK;
1044 }
1045
1046 }
1047 if (status != SSH2_FX_OK)
1048 send_status(id, status);
1049 free(path);
1050 }
1051
1052 static void
process_readdir(u_int32_t id)1053 process_readdir(u_int32_t id)
1054 {
1055 DIR *dirp;
1056 struct dirent *dp;
1057 char *path;
1058 int r, handle;
1059
1060 if ((r = get_handle(iqueue, &handle)) != 0)
1061 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1062
1063 debug("request %u: readdir \"%s\" (handle %d)", id,
1064 handle_to_name(handle), handle);
1065 dirp = handle_to_dir(handle);
1066 path = handle_to_name(handle);
1067 if (dirp == NULL || path == NULL) {
1068 send_status(id, SSH2_FX_FAILURE);
1069 } else {
1070 struct stat st;
1071 char pathname[PATH_MAX];
1072 Stat *stats;
1073 int nstats = 10, count = 0, i;
1074
1075 stats = xcalloc(nstats, sizeof(Stat));
1076 while ((dp = readdir(dirp)) != NULL) {
1077 if (count >= nstats) {
1078 nstats *= 2;
1079 stats = xreallocarray(stats, nstats, sizeof(Stat));
1080 }
1081 /* XXX OVERFLOW ? */
1082 snprintf(pathname, sizeof pathname, "%s%s%s", path,
1083 strcmp(path, "/") ? "/" : "", dp->d_name);
1084 if (lstat(pathname, &st) == -1)
1085 continue;
1086 stat_to_attrib(&st, &(stats[count].attrib));
1087 stats[count].name = xstrdup(dp->d_name);
1088 stats[count].long_name = ls_file(dp->d_name, &st, 0, 0);
1089 count++;
1090 /* send up to 100 entries in one message */
1091 /* XXX check packet size instead */
1092 if (count == 100)
1093 break;
1094 }
1095 if (count > 0) {
1096 send_names(id, count, stats);
1097 for (i = 0; i < count; i++) {
1098 free(stats[i].name);
1099 free(stats[i].long_name);
1100 }
1101 } else {
1102 send_status(id, SSH2_FX_EOF);
1103 }
1104 free(stats);
1105 }
1106 }
1107
1108 static void
process_remove(u_int32_t id)1109 process_remove(u_int32_t id)
1110 {
1111 char *name;
1112 int r, status = SSH2_FX_FAILURE;
1113
1114 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
1115 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1116
1117 debug3("request %u: remove", id);
1118 logit("remove name \"%s\"", name);
1119 r = unlink(name);
1120 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1121 send_status(id, status);
1122 free(name);
1123 }
1124
1125 static void
process_mkdir(u_int32_t id)1126 process_mkdir(u_int32_t id)
1127 {
1128 Attrib a;
1129 char *name;
1130 int r, mode, status = SSH2_FX_FAILURE;
1131
1132 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
1133 (r = decode_attrib(iqueue, &a)) != 0)
1134 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1135
1136 mode = (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ?
1137 a.perm & 07777 : 0777;
1138 debug3("request %u: mkdir", id);
1139 logit("mkdir name \"%s\" mode 0%o", name, mode);
1140 r = mkdir(name, mode);
1141 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1142 send_status(id, status);
1143 free(name);
1144 }
1145
1146 static void
process_rmdir(u_int32_t id)1147 process_rmdir(u_int32_t id)
1148 {
1149 char *name;
1150 int r, status;
1151
1152 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
1153 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1154
1155 debug3("request %u: rmdir", id);
1156 logit("rmdir name \"%s\"", name);
1157 r = rmdir(name);
1158 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1159 send_status(id, status);
1160 free(name);
1161 }
1162
1163 static void
process_realpath(u_int32_t id)1164 process_realpath(u_int32_t id)
1165 {
1166 char resolvedname[PATH_MAX];
1167 char *path;
1168 int r;
1169
1170 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1171 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1172
1173 if (path[0] == '\0') {
1174 free(path);
1175 path = xstrdup(".");
1176 }
1177 debug3("request %u: realpath", id);
1178 verbose("realpath \"%s\"", path);
1179 if (sftp_realpath(path, resolvedname) == NULL) {
1180 send_status(id, errno_to_portable(errno));
1181 } else {
1182 Stat s;
1183 attrib_clear(&s.attrib);
1184 s.name = s.long_name = resolvedname;
1185 send_names(id, 1, &s);
1186 }
1187 free(path);
1188 }
1189
1190 static void
process_rename(u_int32_t id)1191 process_rename(u_int32_t id)
1192 {
1193 char *oldpath, *newpath;
1194 int r, status;
1195 struct stat sb;
1196
1197 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
1198 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
1199 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1200
1201 debug3("request %u: rename", id);
1202 logit("rename old \"%s\" new \"%s\"", oldpath, newpath);
1203 status = SSH2_FX_FAILURE;
1204 if (lstat(oldpath, &sb) == -1)
1205 status = errno_to_portable(errno);
1206 else if (S_ISREG(sb.st_mode)) {
1207 /* Race-free rename of regular files */
1208 if (link(oldpath, newpath) == -1) {
1209 if (errno == EOPNOTSUPP || errno == ENOSYS
1210 #ifdef EXDEV
1211 || errno == EXDEV
1212 #endif
1213 #ifdef LINK_OPNOTSUPP_ERRNO
1214 || errno == LINK_OPNOTSUPP_ERRNO
1215 #endif
1216 ) {
1217 struct stat st;
1218
1219 /*
1220 * fs doesn't support links, so fall back to
1221 * stat+rename. This is racy.
1222 */
1223 if (stat(newpath, &st) == -1) {
1224 if (rename(oldpath, newpath) == -1)
1225 status =
1226 errno_to_portable(errno);
1227 else
1228 status = SSH2_FX_OK;
1229 }
1230 } else {
1231 status = errno_to_portable(errno);
1232 }
1233 } else if (unlink(oldpath) == -1) {
1234 status = errno_to_portable(errno);
1235 /* clean spare link */
1236 unlink(newpath);
1237 } else
1238 status = SSH2_FX_OK;
1239 } else if (stat(newpath, &sb) == -1) {
1240 if (rename(oldpath, newpath) == -1)
1241 status = errno_to_portable(errno);
1242 else
1243 status = SSH2_FX_OK;
1244 }
1245 send_status(id, status);
1246 free(oldpath);
1247 free(newpath);
1248 }
1249
1250 static void
process_readlink(u_int32_t id)1251 process_readlink(u_int32_t id)
1252 {
1253 int r, len;
1254 char buf[PATH_MAX];
1255 char *path;
1256
1257 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1258 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1259
1260 debug3("request %u: readlink", id);
1261 verbose("readlink \"%s\"", path);
1262 if ((len = readlink(path, buf, sizeof(buf) - 1)) == -1)
1263 send_status(id, errno_to_portable(errno));
1264 else {
1265 Stat s;
1266
1267 buf[len] = '\0';
1268 attrib_clear(&s.attrib);
1269 s.name = s.long_name = buf;
1270 send_names(id, 1, &s);
1271 }
1272 free(path);
1273 }
1274
1275 static void
process_symlink(u_int32_t id)1276 process_symlink(u_int32_t id)
1277 {
1278 char *oldpath, *newpath;
1279 int r, status;
1280
1281 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
1282 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
1283 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1284
1285 debug3("request %u: symlink", id);
1286 logit("symlink old \"%s\" new \"%s\"", oldpath, newpath);
1287 /* this will fail if 'newpath' exists */
1288 r = symlink(oldpath, newpath);
1289 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1290 send_status(id, status);
1291 free(oldpath);
1292 free(newpath);
1293 }
1294
1295 static void
process_extended_posix_rename(u_int32_t id)1296 process_extended_posix_rename(u_int32_t id)
1297 {
1298 char *oldpath, *newpath;
1299 int r, status;
1300
1301 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
1302 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
1303 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1304
1305 debug3("request %u: posix-rename", id);
1306 logit("posix-rename old \"%s\" new \"%s\"", oldpath, newpath);
1307 r = rename(oldpath, newpath);
1308 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1309 send_status(id, status);
1310 free(oldpath);
1311 free(newpath);
1312 }
1313
1314 static void
process_extended_statvfs(u_int32_t id)1315 process_extended_statvfs(u_int32_t id)
1316 {
1317 char *path;
1318 struct statvfs st;
1319 int r;
1320
1321 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1322 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1323 debug3("request %u: statvfs", id);
1324 logit("statvfs \"%s\"", path);
1325
1326 if (statvfs(path, &st) != 0)
1327 send_status(id, errno_to_portable(errno));
1328 else
1329 send_statvfs(id, &st);
1330 free(path);
1331 }
1332
1333 static void
process_extended_fstatvfs(u_int32_t id)1334 process_extended_fstatvfs(u_int32_t id)
1335 {
1336 int r, handle, fd;
1337 struct statvfs st;
1338
1339 if ((r = get_handle(iqueue, &handle)) != 0)
1340 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1341 debug("request %u: fstatvfs \"%s\" (handle %u)",
1342 id, handle_to_name(handle), handle);
1343 if ((fd = handle_to_fd(handle)) < 0) {
1344 send_status(id, SSH2_FX_FAILURE);
1345 return;
1346 }
1347 if (fstatvfs(fd, &st) != 0)
1348 send_status(id, errno_to_portable(errno));
1349 else
1350 send_statvfs(id, &st);
1351 }
1352
1353 static void
process_extended_hardlink(u_int32_t id)1354 process_extended_hardlink(u_int32_t id)
1355 {
1356 char *oldpath, *newpath;
1357 int r, status;
1358
1359 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
1360 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
1361 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1362
1363 debug3("request %u: hardlink", id);
1364 logit("hardlink old \"%s\" new \"%s\"", oldpath, newpath);
1365 r = link(oldpath, newpath);
1366 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1367 send_status(id, status);
1368 free(oldpath);
1369 free(newpath);
1370 }
1371
1372 static void
process_extended_fsync(u_int32_t id)1373 process_extended_fsync(u_int32_t id)
1374 {
1375 int handle, fd, r, status = SSH2_FX_OP_UNSUPPORTED;
1376
1377 if ((r = get_handle(iqueue, &handle)) != 0)
1378 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1379 debug3("request %u: fsync (handle %u)", id, handle);
1380 verbose("fsync \"%s\"", handle_to_name(handle));
1381 if ((fd = handle_to_fd(handle)) < 0)
1382 status = SSH2_FX_NO_SUCH_FILE;
1383 else if (handle_is_ok(handle, HANDLE_FILE)) {
1384 r = fsync(fd);
1385 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1386 }
1387 send_status(id, status);
1388 }
1389
1390 static void
process_extended_lsetstat(u_int32_t id)1391 process_extended_lsetstat(u_int32_t id)
1392 {
1393 Attrib a;
1394 char *name;
1395 int r, status = SSH2_FX_OK;
1396
1397 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
1398 (r = decode_attrib(iqueue, &a)) != 0)
1399 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1400
1401 debug("request %u: lsetstat name \"%s\"", id, name);
1402 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) {
1403 /* nonsensical for links */
1404 status = SSH2_FX_BAD_MESSAGE;
1405 goto out;
1406 }
1407 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
1408 logit("set \"%s\" mode %04o", name, a.perm);
1409 r = fchmodat(AT_FDCWD, name,
1410 a.perm & 07777, AT_SYMLINK_NOFOLLOW);
1411 if (r == -1)
1412 status = errno_to_portable(errno);
1413 }
1414 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
1415 char buf[64];
1416 time_t t = a.mtime;
1417
1418 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
1419 localtime(&t));
1420 logit("set \"%s\" modtime %s", name, buf);
1421 r = utimensat(AT_FDCWD, name,
1422 attrib_to_ts(&a), AT_SYMLINK_NOFOLLOW);
1423 if (r == -1)
1424 status = errno_to_portable(errno);
1425 }
1426 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) {
1427 logit("set \"%s\" owner %lu group %lu", name,
1428 (u_long)a.uid, (u_long)a.gid);
1429 r = fchownat(AT_FDCWD, name, a.uid, a.gid,
1430 AT_SYMLINK_NOFOLLOW);
1431 if (r == -1)
1432 status = errno_to_portable(errno);
1433 }
1434 out:
1435 send_status(id, status);
1436 free(name);
1437 }
1438
1439 static void
process_extended(u_int32_t id)1440 process_extended(u_int32_t id)
1441 {
1442 char *request;
1443 int i, r;
1444
1445 if ((r = sshbuf_get_cstring(iqueue, &request, NULL)) != 0)
1446 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1447 for (i = 0; extended_handlers[i].handler != NULL; i++) {
1448 if (strcmp(request, extended_handlers[i].ext_name) == 0) {
1449 if (!request_permitted(&extended_handlers[i]))
1450 send_status(id, SSH2_FX_PERMISSION_DENIED);
1451 else
1452 extended_handlers[i].handler(id);
1453 break;
1454 }
1455 }
1456 if (extended_handlers[i].handler == NULL) {
1457 error("Unknown extended request \"%.100s\"", request);
1458 send_status(id, SSH2_FX_OP_UNSUPPORTED); /* MUST */
1459 }
1460 free(request);
1461 }
1462
1463 /* stolen from ssh-agent */
1464
1465 static void
process(void)1466 process(void)
1467 {
1468 u_int msg_len;
1469 u_int buf_len;
1470 u_int consumed;
1471 u_char type;
1472 const u_char *cp;
1473 int i, r;
1474 u_int32_t id;
1475
1476 buf_len = sshbuf_len(iqueue);
1477 if (buf_len < 5)
1478 return; /* Incomplete message. */
1479 cp = sshbuf_ptr(iqueue);
1480 msg_len = get_u32(cp);
1481 if (msg_len > SFTP_MAX_MSG_LENGTH) {
1482 error("bad message from %s local user %s",
1483 client_addr, pw->pw_name);
1484 sftp_server_cleanup_exit(11);
1485 }
1486 if (buf_len < msg_len + 4)
1487 return;
1488 if ((r = sshbuf_consume(iqueue, 4)) != 0)
1489 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1490 buf_len -= 4;
1491 if ((r = sshbuf_get_u8(iqueue, &type)) != 0)
1492 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1493
1494 switch (type) {
1495 case SSH2_FXP_INIT:
1496 process_init();
1497 init_done = 1;
1498 break;
1499 case SSH2_FXP_EXTENDED:
1500 if (!init_done)
1501 fatal("Received extended request before init");
1502 if ((r = sshbuf_get_u32(iqueue, &id)) != 0)
1503 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1504 process_extended(id);
1505 break;
1506 default:
1507 if (!init_done)
1508 fatal("Received %u request before init", type);
1509 if ((r = sshbuf_get_u32(iqueue, &id)) != 0)
1510 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1511 for (i = 0; handlers[i].handler != NULL; i++) {
1512 if (type == handlers[i].type) {
1513 if (!request_permitted(&handlers[i])) {
1514 send_status(id,
1515 SSH2_FX_PERMISSION_DENIED);
1516 } else {
1517 handlers[i].handler(id);
1518 }
1519 break;
1520 }
1521 }
1522 if (handlers[i].handler == NULL)
1523 error("Unknown message %u", type);
1524 }
1525 /* discard the remaining bytes from the current packet */
1526 if (buf_len < sshbuf_len(iqueue)) {
1527 error("iqueue grew unexpectedly");
1528 sftp_server_cleanup_exit(255);
1529 }
1530 consumed = buf_len - sshbuf_len(iqueue);
1531 if (msg_len < consumed) {
1532 error("msg_len %u < consumed %u", msg_len, consumed);
1533 sftp_server_cleanup_exit(255);
1534 }
1535 if (msg_len > consumed &&
1536 (r = sshbuf_consume(iqueue, msg_len - consumed)) != 0)
1537 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1538 }
1539
1540 /* Cleanup handler that logs active handles upon normal exit */
1541 void
sftp_server_cleanup_exit(int i)1542 sftp_server_cleanup_exit(int i)
1543 {
1544 if (pw != NULL && client_addr != NULL) {
1545 handle_log_exit();
1546 logit("session closed for local user %s from [%s]",
1547 pw->pw_name, client_addr);
1548 }
1549 _exit(i);
1550 }
1551
1552 static void
sftp_server_usage(void)1553 sftp_server_usage(void)
1554 {
1555 extern char *__progname;
1556
1557 fprintf(stderr,
1558 "usage: %s [-ehR] [-d start_directory] [-f log_facility] "
1559 "[-l log_level]\n\t[-P blacklisted_requests] "
1560 "[-p whitelisted_requests] [-u umask]\n"
1561 " %s -Q protocol_feature\n",
1562 __progname, __progname);
1563 exit(1);
1564 }
1565
1566 int
sftp_server_main(int argc,char ** argv,struct passwd * user_pw)1567 sftp_server_main(int argc, char **argv, struct passwd *user_pw)
1568 {
1569 fd_set *rset, *wset;
1570 int i, r, in, out, max, ch, skipargs = 0, log_stderr = 0;
1571 ssize_t len, olen, set_size;
1572 SyslogFacility log_facility = SYSLOG_FACILITY_AUTH;
1573 char *cp, *homedir = NULL, uidstr[32], buf[4*4096];
1574 long mask;
1575
1576 extern char *optarg;
1577 extern char *__progname;
1578
1579 __progname = ssh_get_progname(argv[0]);
1580 log_init(__progname, log_level, log_facility, log_stderr);
1581
1582 pw = pwcopy(user_pw);
1583
1584 while (!skipargs && (ch = getopt(argc, argv,
1585 "d:f:l:P:p:Q:u:cehR")) != -1) {
1586 switch (ch) {
1587 case 'Q':
1588 if (strcasecmp(optarg, "requests") != 0) {
1589 fprintf(stderr, "Invalid query type\n");
1590 exit(1);
1591 }
1592 for (i = 0; handlers[i].handler != NULL; i++)
1593 printf("%s\n", handlers[i].name);
1594 for (i = 0; extended_handlers[i].handler != NULL; i++)
1595 printf("%s\n", extended_handlers[i].name);
1596 exit(0);
1597 break;
1598 case 'R':
1599 readonly = 1;
1600 break;
1601 case 'c':
1602 /*
1603 * Ignore all arguments if we are invoked as a
1604 * shell using "sftp-server -c command"
1605 */
1606 skipargs = 1;
1607 break;
1608 case 'e':
1609 log_stderr = 1;
1610 break;
1611 case 'l':
1612 log_level = log_level_number(optarg);
1613 if (log_level == SYSLOG_LEVEL_NOT_SET)
1614 error("Invalid log level \"%s\"", optarg);
1615 break;
1616 case 'f':
1617 log_facility = log_facility_number(optarg);
1618 if (log_facility == SYSLOG_FACILITY_NOT_SET)
1619 error("Invalid log facility \"%s\"", optarg);
1620 break;
1621 case 'd':
1622 cp = tilde_expand_filename(optarg, user_pw->pw_uid);
1623 snprintf(uidstr, sizeof(uidstr), "%llu",
1624 (unsigned long long)pw->pw_uid);
1625 homedir = percent_expand(cp, "d", user_pw->pw_dir,
1626 "u", user_pw->pw_name, "U", uidstr, (char *)NULL);
1627 free(cp);
1628 break;
1629 case 'p':
1630 if (request_whitelist != NULL)
1631 fatal("Permitted requests already set");
1632 request_whitelist = xstrdup(optarg);
1633 break;
1634 case 'P':
1635 if (request_blacklist != NULL)
1636 fatal("Refused requests already set");
1637 request_blacklist = xstrdup(optarg);
1638 break;
1639 case 'u':
1640 errno = 0;
1641 mask = strtol(optarg, &cp, 8);
1642 if (mask < 0 || mask > 0777 || *cp != '\0' ||
1643 cp == optarg || (mask == 0 && errno != 0))
1644 fatal("Invalid umask \"%s\"", optarg);
1645 (void)umask((mode_t)mask);
1646 break;
1647 case 'h':
1648 default:
1649 sftp_server_usage();
1650 }
1651 }
1652
1653 log_init(__progname, log_level, log_facility, log_stderr);
1654
1655 /*
1656 * On platforms where we can, avoid making /proc/self/{mem,maps}
1657 * available to the user so that sftp access doesn't automatically
1658 * imply arbitrary code execution access that will break
1659 * restricted configurations.
1660 */
1661 platform_disable_tracing(1); /* strict */
1662
1663 /* Drop any fine-grained privileges we don't need */
1664 platform_pledge_sftp_server();
1665
1666 if ((cp = getenv("SSH_CONNECTION")) != NULL) {
1667 client_addr = xstrdup(cp);
1668 if ((cp = strchr(client_addr, ' ')) == NULL) {
1669 error("Malformed SSH_CONNECTION variable: \"%s\"",
1670 getenv("SSH_CONNECTION"));
1671 sftp_server_cleanup_exit(255);
1672 }
1673 *cp = '\0';
1674 } else
1675 client_addr = xstrdup("UNKNOWN");
1676
1677 logit("session opened for local user %s from [%s]",
1678 pw->pw_name, client_addr);
1679
1680 in = STDIN_FILENO;
1681 out = STDOUT_FILENO;
1682
1683 #ifdef HAVE_CYGWIN
1684 setmode(in, O_BINARY);
1685 setmode(out, O_BINARY);
1686 #endif
1687
1688 max = 0;
1689 if (in > max)
1690 max = in;
1691 if (out > max)
1692 max = out;
1693
1694 if ((iqueue = sshbuf_new()) == NULL)
1695 fatal("%s: sshbuf_new failed", __func__);
1696 if ((oqueue = sshbuf_new()) == NULL)
1697 fatal("%s: sshbuf_new failed", __func__);
1698
1699 rset = xcalloc(howmany(max + 1, NFDBITS), sizeof(fd_mask));
1700 wset = xcalloc(howmany(max + 1, NFDBITS), sizeof(fd_mask));
1701
1702 if (homedir != NULL) {
1703 if (chdir(homedir) != 0) {
1704 error("chdir to \"%s\" failed: %s", homedir,
1705 strerror(errno));
1706 }
1707 }
1708
1709 set_size = howmany(max + 1, NFDBITS) * sizeof(fd_mask);
1710 for (;;) {
1711 memset(rset, 0, set_size);
1712 memset(wset, 0, set_size);
1713
1714 /*
1715 * Ensure that we can read a full buffer and handle
1716 * the worst-case length packet it can generate,
1717 * otherwise apply backpressure by stopping reads.
1718 */
1719 if ((r = sshbuf_check_reserve(iqueue, sizeof(buf))) == 0 &&
1720 (r = sshbuf_check_reserve(oqueue,
1721 SFTP_MAX_MSG_LENGTH)) == 0)
1722 FD_SET(in, rset);
1723 else if (r != SSH_ERR_NO_BUFFER_SPACE)
1724 fatal("%s: sshbuf_check_reserve failed: %s",
1725 __func__, ssh_err(r));
1726
1727 olen = sshbuf_len(oqueue);
1728 if (olen > 0)
1729 FD_SET(out, wset);
1730
1731 if (select(max+1, rset, wset, NULL, NULL) == -1) {
1732 if (errno == EINTR)
1733 continue;
1734 error("select: %s", strerror(errno));
1735 sftp_server_cleanup_exit(2);
1736 }
1737
1738 /* copy stdin to iqueue */
1739 if (FD_ISSET(in, rset)) {
1740 len = read(in, buf, sizeof buf);
1741 if (len == 0) {
1742 debug("read eof");
1743 sftp_server_cleanup_exit(0);
1744 } else if (len == -1) {
1745 error("read: %s", strerror(errno));
1746 sftp_server_cleanup_exit(1);
1747 } else if ((r = sshbuf_put(iqueue, buf, len)) != 0) {
1748 fatal("%s: buffer error: %s",
1749 __func__, ssh_err(r));
1750 }
1751 }
1752 /* send oqueue to stdout */
1753 if (FD_ISSET(out, wset)) {
1754 len = write(out, sshbuf_ptr(oqueue), olen);
1755 if (len == -1) {
1756 error("write: %s", strerror(errno));
1757 sftp_server_cleanup_exit(1);
1758 } else if ((r = sshbuf_consume(oqueue, len)) != 0) {
1759 fatal("%s: buffer error: %s",
1760 __func__, ssh_err(r));
1761 }
1762 }
1763
1764 /*
1765 * Process requests from client if we can fit the results
1766 * into the output buffer, otherwise stop processing input
1767 * and let the output queue drain.
1768 */
1769 r = sshbuf_check_reserve(oqueue, SFTP_MAX_MSG_LENGTH);
1770 if (r == 0)
1771 process();
1772 else if (r != SSH_ERR_NO_BUFFER_SPACE)
1773 fatal("%s: sshbuf_check_reserve: %s",
1774 __func__, ssh_err(r));
1775 }
1776 }
1777