1 /* $OpenBSD: sftp-server.c,v 1.156 2026/07/01 00:52:23 dtucker 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/resource.h>
22 #include <sys/stat.h>
23 #include <sys/time.h>
24 #include <sys/statvfs.h>
25
26 #include <dirent.h>
27 #include <errno.h>
28 #include <fcntl.h>
29 #include <limits.h>
30 #include <poll.h>
31 #include <pwd.h>
32 #include <grp.h>
33 #include <stdlib.h>
34 #include <stdio.h>
35 #include <string.h>
36 #include <time.h>
37 #include <unistd.h>
38 #include <stdarg.h>
39
40 #include "atomicio.h"
41 #include "xmalloc.h"
42 #include "sshbuf.h"
43 #include "ssherr.h"
44 #include "log.h"
45 #include "misc.h"
46 #include "match.h"
47 #include "uidswap.h"
48
49 #include "sftp.h"
50 #include "sftp-common.h"
51
52 char *sftp_realpath(const char *, char *); /* sftp-realpath.c */
53
54 /* Maximum data read that we are willing to accept */
55 #define SFTP_MAX_READ_LENGTH (SFTP_MAX_MSG_LENGTH - 1024)
56
57 /* Our verbosity */
58 static LogLevel log_level = SYSLOG_LEVEL_ERROR;
59
60 /* Our client */
61 static struct passwd *pw = NULL;
62 static char *client_addr = NULL;
63
64 /* input and output queue */
65 struct sshbuf *iqueue;
66 struct sshbuf *oqueue;
67
68 /* Version of client */
69 static u_int version;
70
71 /* SSH2_FXP_INIT received */
72 static int init_done;
73
74 /* Disable writes */
75 static int readonly;
76
77 /* Requests that are allowed/denied */
78 static char *request_allowlist, *request_denylist;
79
80 /* portable attributes, etc. */
81 typedef struct Stat Stat;
82
83 struct Stat {
84 char *name;
85 char *long_name;
86 Attrib attrib;
87 };
88
89 /* Packet handlers */
90 static void process_open(uint32_t id);
91 static void process_close(uint32_t id);
92 static void process_read(uint32_t id);
93 static void process_write(uint32_t id);
94 static void process_stat(uint32_t id);
95 static void process_lstat(uint32_t id);
96 static void process_fstat(uint32_t id);
97 static void process_setstat(uint32_t id);
98 static void process_fsetstat(uint32_t id);
99 static void process_opendir(uint32_t id);
100 static void process_readdir(uint32_t id);
101 static void process_remove(uint32_t id);
102 static void process_mkdir(uint32_t id);
103 static void process_rmdir(uint32_t id);
104 static void process_realpath(uint32_t id);
105 static void process_rename(uint32_t id);
106 static void process_readlink(uint32_t id);
107 static void process_symlink(uint32_t id);
108 static void process_extended_posix_rename(uint32_t id);
109 static void process_extended_statvfs(uint32_t id);
110 static void process_extended_fstatvfs(uint32_t id);
111 static void process_extended_hardlink(uint32_t id);
112 static void process_extended_fsync(uint32_t id);
113 static void process_extended_lsetstat(uint32_t id);
114 static void process_extended_limits(uint32_t id);
115 static void process_extended_expand(uint32_t id);
116 static void process_extended_copy_data(uint32_t id);
117 static void process_extended_home_directory(uint32_t id);
118 static void process_extended_get_users_groups_by_id(uint32_t id);
119 static void process_extended(uint32_t id);
120
121 struct sftp_handler {
122 const char *name; /* user-visible name for fine-grained perms */
123 const char *ext_name; /* extended request name */
124 u_int type; /* packet type, for non extended packets */
125 void (*handler)(uint32_t);
126 int does_write; /* if nonzero, banned for readonly mode */
127 };
128
129 static const struct sftp_handler handlers[] = {
130 /* NB. SSH2_FXP_OPEN does the readonly check in the handler itself */
131 { "open", NULL, SSH2_FXP_OPEN, process_open, 0 },
132 { "close", NULL, SSH2_FXP_CLOSE, process_close, 0 },
133 { "read", NULL, SSH2_FXP_READ, process_read, 0 },
134 { "write", NULL, SSH2_FXP_WRITE, process_write, 1 },
135 { "lstat", NULL, SSH2_FXP_LSTAT, process_lstat, 0 },
136 { "fstat", NULL, SSH2_FXP_FSTAT, process_fstat, 0 },
137 { "setstat", NULL, SSH2_FXP_SETSTAT, process_setstat, 1 },
138 { "fsetstat", NULL, SSH2_FXP_FSETSTAT, process_fsetstat, 1 },
139 { "opendir", NULL, SSH2_FXP_OPENDIR, process_opendir, 0 },
140 { "readdir", NULL, SSH2_FXP_READDIR, process_readdir, 0 },
141 { "remove", NULL, SSH2_FXP_REMOVE, process_remove, 1 },
142 { "mkdir", NULL, SSH2_FXP_MKDIR, process_mkdir, 1 },
143 { "rmdir", NULL, SSH2_FXP_RMDIR, process_rmdir, 1 },
144 { "realpath", NULL, SSH2_FXP_REALPATH, process_realpath, 0 },
145 { "stat", NULL, SSH2_FXP_STAT, process_stat, 0 },
146 { "rename", NULL, SSH2_FXP_RENAME, process_rename, 1 },
147 { "readlink", NULL, SSH2_FXP_READLINK, process_readlink, 0 },
148 { "symlink", NULL, SSH2_FXP_SYMLINK, process_symlink, 1 },
149 { NULL, NULL, 0, NULL, 0 }
150 };
151
152 /* SSH2_FXP_EXTENDED submessages */
153 static const struct sftp_handler extended_handlers[] = {
154 { "posix-rename", "posix-rename@openssh.com", 0,
155 process_extended_posix_rename, 1 },
156 { "statvfs", "statvfs@openssh.com", 0, process_extended_statvfs, 0 },
157 { "fstatvfs", "fstatvfs@openssh.com", 0, process_extended_fstatvfs, 0 },
158 { "hardlink", "hardlink@openssh.com", 0, process_extended_hardlink, 1 },
159 { "fsync", "fsync@openssh.com", 0, process_extended_fsync, 1 },
160 { "lsetstat", "lsetstat@openssh.com", 0, process_extended_lsetstat, 1 },
161 { "limits", "limits@openssh.com", 0, process_extended_limits, 0 },
162 { "expand-path", "expand-path@openssh.com", 0,
163 process_extended_expand, 0 },
164 { "copy-data", "copy-data", 0, process_extended_copy_data, 1 },
165 { "home-directory", "home-directory", 0,
166 process_extended_home_directory, 0 },
167 { "users-groups-by-id", "users-groups-by-id@openssh.com", 0,
168 process_extended_get_users_groups_by_id, 0 },
169 { NULL, NULL, 0, NULL, 0 }
170 };
171
172 static const struct sftp_handler *
extended_handler_byname(const char * name)173 extended_handler_byname(const char *name)
174 {
175 int i;
176
177 for (i = 0; extended_handlers[i].handler != NULL; i++) {
178 if (strcmp(name, extended_handlers[i].ext_name) == 0)
179 return &extended_handlers[i];
180 }
181 return NULL;
182 }
183
184 static int
request_permitted(const struct sftp_handler * h)185 request_permitted(const struct sftp_handler *h)
186 {
187 char *result;
188
189 if (readonly && h->does_write) {
190 verbose("Refusing %s request in read-only mode", h->name);
191 return 0;
192 }
193 if (request_denylist != NULL &&
194 ((result = match_list(h->name, request_denylist, NULL))) != NULL) {
195 free(result);
196 verbose("Refusing denylisted %s request", h->name);
197 return 0;
198 }
199 if (request_allowlist != NULL &&
200 ((result = match_list(h->name, request_allowlist, NULL))) != NULL) {
201 free(result);
202 debug2("Permitting allowlisted %s request", h->name);
203 return 1;
204 }
205 if (request_allowlist != NULL) {
206 verbose("Refusing non-allowlisted %s request", h->name);
207 return 0;
208 }
209 return 1;
210 }
211
212 static int
errno_to_portable(int unixerrno)213 errno_to_portable(int unixerrno)
214 {
215 int ret = 0;
216
217 switch (unixerrno) {
218 case 0:
219 ret = SSH2_FX_OK;
220 break;
221 case ENOENT:
222 case ENOTDIR:
223 case EBADF:
224 case ELOOP:
225 ret = SSH2_FX_NO_SUCH_FILE;
226 break;
227 case EPERM:
228 case EACCES:
229 case EFAULT:
230 ret = SSH2_FX_PERMISSION_DENIED;
231 break;
232 case ENAMETOOLONG:
233 case EINVAL:
234 ret = SSH2_FX_BAD_MESSAGE;
235 break;
236 case ENOSYS:
237 ret = SSH2_FX_OP_UNSUPPORTED;
238 break;
239 default:
240 ret = SSH2_FX_FAILURE;
241 break;
242 }
243 return ret;
244 }
245
246 static int
flags_from_portable(int pflags)247 flags_from_portable(int pflags)
248 {
249 int flags = 0;
250
251 if ((pflags & SSH2_FXF_READ) &&
252 (pflags & SSH2_FXF_WRITE)) {
253 flags = O_RDWR;
254 } else if (pflags & SSH2_FXF_READ) {
255 flags = O_RDONLY;
256 } else if (pflags & SSH2_FXF_WRITE) {
257 flags = O_WRONLY;
258 }
259 if (pflags & SSH2_FXF_APPEND)
260 flags |= O_APPEND;
261 if (pflags & SSH2_FXF_CREAT)
262 flags |= O_CREAT;
263 if (pflags & SSH2_FXF_TRUNC)
264 flags |= O_TRUNC;
265 if (pflags & SSH2_FXF_EXCL)
266 flags |= O_EXCL;
267 return flags;
268 }
269
270 static const char *
string_from_portable(int pflags)271 string_from_portable(int pflags)
272 {
273 static char ret[128];
274
275 *ret = '\0';
276
277 #define PAPPEND(str) { \
278 if (*ret != '\0') \
279 strlcat(ret, ",", sizeof(ret)); \
280 strlcat(ret, str, sizeof(ret)); \
281 }
282
283 if (pflags & SSH2_FXF_READ)
284 PAPPEND("READ")
285 if (pflags & SSH2_FXF_WRITE)
286 PAPPEND("WRITE")
287 if (pflags & SSH2_FXF_APPEND)
288 PAPPEND("APPEND")
289 if (pflags & SSH2_FXF_CREAT)
290 PAPPEND("CREATE")
291 if (pflags & SSH2_FXF_TRUNC)
292 PAPPEND("TRUNCATE")
293 if (pflags & SSH2_FXF_EXCL)
294 PAPPEND("EXCL")
295
296 return ret;
297 }
298
299 /* handle handles */
300
301 typedef struct Handle Handle;
302 struct Handle {
303 int use;
304 DIR *dirp;
305 int fd;
306 int flags;
307 char *name;
308 uint64_t bytes_read, bytes_write;
309 int next_unused;
310 };
311
312 enum {
313 HANDLE_UNUSED,
314 HANDLE_DIR,
315 HANDLE_FILE
316 };
317
318 static Handle *handles = NULL;
319 static u_int num_handles = 0;
320 static int first_unused_handle = -1;
321
handle_unused(int i)322 static void handle_unused(int i)
323 {
324 handles[i].use = HANDLE_UNUSED;
325 handles[i].next_unused = first_unused_handle;
326 first_unused_handle = i;
327 }
328
329 static int
handle_new(int use,const char * name,int fd,int flags,DIR * dirp)330 handle_new(int use, const char *name, int fd, int flags, DIR *dirp)
331 {
332 int i;
333
334 if (first_unused_handle == -1) {
335 if (num_handles + 1 <= num_handles)
336 return -1;
337 num_handles++;
338 handles = xreallocarray(handles, num_handles, sizeof(Handle));
339 handle_unused(num_handles - 1);
340 }
341
342 i = first_unused_handle;
343 first_unused_handle = handles[i].next_unused;
344
345 handles[i].use = use;
346 handles[i].dirp = dirp;
347 handles[i].fd = fd;
348 handles[i].flags = flags;
349 handles[i].name = xstrdup(name);
350 handles[i].bytes_read = handles[i].bytes_write = 0;
351
352 return i;
353 }
354
355 static int
handle_is_ok(int i,int type)356 handle_is_ok(int i, int type)
357 {
358 return i >= 0 && (u_int)i < num_handles && handles[i].use == type;
359 }
360
361 static int
handle_to_string(int handle,u_char ** stringp,int * hlenp)362 handle_to_string(int handle, u_char **stringp, int *hlenp)
363 {
364 if (stringp == NULL || hlenp == NULL)
365 return -1;
366 *stringp = xmalloc(sizeof(int32_t));
367 put_u32(*stringp, handle);
368 *hlenp = sizeof(int32_t);
369 return 0;
370 }
371
372 static int
handle_from_string(const u_char * handle,u_int hlen)373 handle_from_string(const u_char *handle, u_int hlen)
374 {
375 int val;
376
377 if (hlen != sizeof(int32_t))
378 return -1;
379 val = get_u32(handle);
380 if (handle_is_ok(val, HANDLE_FILE) ||
381 handle_is_ok(val, HANDLE_DIR))
382 return val;
383 return -1;
384 }
385
386 static char *
handle_to_name(int handle)387 handle_to_name(int handle)
388 {
389 if (handle_is_ok(handle, HANDLE_DIR)||
390 handle_is_ok(handle, HANDLE_FILE))
391 return handles[handle].name;
392 return NULL;
393 }
394
395 static DIR *
handle_to_dir(int handle)396 handle_to_dir(int handle)
397 {
398 if (handle_is_ok(handle, HANDLE_DIR))
399 return handles[handle].dirp;
400 return NULL;
401 }
402
403 static int
handle_to_fd(int handle)404 handle_to_fd(int handle)
405 {
406 if (handle_is_ok(handle, HANDLE_FILE))
407 return handles[handle].fd;
408 return -1;
409 }
410
411 static int
handle_to_flags(int handle)412 handle_to_flags(int handle)
413 {
414 if (handle_is_ok(handle, HANDLE_FILE))
415 return handles[handle].flags;
416 return 0;
417 }
418
419 static void
handle_update_read(int handle,ssize_t bytes)420 handle_update_read(int handle, ssize_t bytes)
421 {
422 if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
423 handles[handle].bytes_read += bytes;
424 }
425
426 static void
handle_update_write(int handle,ssize_t bytes)427 handle_update_write(int handle, ssize_t bytes)
428 {
429 if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
430 handles[handle].bytes_write += bytes;
431 }
432
433 static uint64_t
handle_bytes_read(int handle)434 handle_bytes_read(int handle)
435 {
436 if (handle_is_ok(handle, HANDLE_FILE))
437 return (handles[handle].bytes_read);
438 return 0;
439 }
440
441 static uint64_t
handle_bytes_write(int handle)442 handle_bytes_write(int handle)
443 {
444 if (handle_is_ok(handle, HANDLE_FILE))
445 return (handles[handle].bytes_write);
446 return 0;
447 }
448
449 static int
handle_close(int handle)450 handle_close(int handle)
451 {
452 int ret = -1;
453
454 if (handle_is_ok(handle, HANDLE_FILE)) {
455 ret = close(handles[handle].fd);
456 free(handles[handle].name);
457 handle_unused(handle);
458 } else if (handle_is_ok(handle, HANDLE_DIR)) {
459 ret = closedir(handles[handle].dirp);
460 free(handles[handle].name);
461 handle_unused(handle);
462 } else {
463 errno = ENOENT;
464 }
465 return ret;
466 }
467
468 static void
handle_log_close(int handle,char * emsg)469 handle_log_close(int handle, char *emsg)
470 {
471 if (handle_is_ok(handle, HANDLE_FILE)) {
472 logit("%s%sclose \"%s\" bytes read %llu written %llu",
473 emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
474 handle_to_name(handle),
475 (unsigned long long)handle_bytes_read(handle),
476 (unsigned long long)handle_bytes_write(handle));
477 } else {
478 logit("%s%sclosedir \"%s\"",
479 emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
480 handle_to_name(handle));
481 }
482 }
483
484 static void
handle_log_exit(void)485 handle_log_exit(void)
486 {
487 u_int i;
488
489 for (i = 0; i < num_handles; i++)
490 if (handles[i].use != HANDLE_UNUSED)
491 handle_log_close(i, "forced");
492 }
493
494 static int
get_handle(struct sshbuf * queue,int * hp)495 get_handle(struct sshbuf *queue, int *hp)
496 {
497 u_char *handle;
498 int r;
499 size_t hlen;
500
501 *hp = -1;
502 if ((r = sshbuf_get_string(queue, &handle, &hlen)) != 0)
503 return r;
504 if (hlen < 256)
505 *hp = handle_from_string(handle, hlen);
506 free(handle);
507 return 0;
508 }
509
510 /* send replies */
511
512 static void
send_msg(struct sshbuf * m)513 send_msg(struct sshbuf *m)
514 {
515 int r;
516
517 if ((r = sshbuf_put_stringb(oqueue, m)) != 0)
518 fatal_fr(r, "enqueue");
519 sshbuf_reset(m);
520 }
521
522 static const char *
status_to_message(uint32_t status)523 status_to_message(uint32_t status)
524 {
525 static const char * const status_messages[] = {
526 "Success", /* SSH_FX_OK */
527 "End of file", /* SSH_FX_EOF */
528 "No such file", /* SSH_FX_NO_SUCH_FILE */
529 "Permission denied", /* SSH_FX_PERMISSION_DENIED */
530 "Failure", /* SSH_FX_FAILURE */
531 "Bad message", /* SSH_FX_BAD_MESSAGE */
532 "No connection", /* SSH_FX_NO_CONNECTION */
533 "Connection lost", /* SSH_FX_CONNECTION_LOST */
534 "Operation unsupported", /* SSH_FX_OP_UNSUPPORTED */
535 "Unknown error" /* Others */
536 };
537 return (status_messages[MINIMUM(status,SSH2_FX_MAX)]);
538 }
539
540 static void
send_status_errmsg(uint32_t id,uint32_t status,const char * errmsg)541 send_status_errmsg(uint32_t id, uint32_t status, const char *errmsg)
542 {
543 struct sshbuf *msg;
544 int r;
545
546 debug3("request %u: sent status %u", id, status);
547 if (log_level > SYSLOG_LEVEL_VERBOSE ||
548 (status != SSH2_FX_OK && status != SSH2_FX_EOF))
549 logit("sent status %s", status_to_message(status));
550 if ((msg = sshbuf_new()) == NULL)
551 fatal_f("sshbuf_new failed");
552 if ((r = sshbuf_put_u8(msg, SSH2_FXP_STATUS)) != 0 ||
553 (r = sshbuf_put_u32(msg, id)) != 0 ||
554 (r = sshbuf_put_u32(msg, status)) != 0)
555 fatal_fr(r, "compose");
556 if (version >= 3) {
557 if ((r = sshbuf_put_cstring(msg, errmsg == NULL ?
558 status_to_message(status) : errmsg)) != 0 ||
559 (r = sshbuf_put_cstring(msg, "")) != 0)
560 fatal_fr(r, "compose message");
561 }
562 send_msg(msg);
563 sshbuf_free(msg);
564 }
565
566 static void
send_status(uint32_t id,uint32_t status)567 send_status(uint32_t id, uint32_t status)
568 {
569 send_status_errmsg(id, status, NULL);
570 }
571
572 static void
send_data_or_handle(char type,uint32_t id,const u_char * data,int dlen)573 send_data_or_handle(char type, uint32_t id, const u_char *data, int dlen)
574 {
575 struct sshbuf *msg;
576 int r;
577
578 if ((msg = sshbuf_new()) == NULL)
579 fatal_f("sshbuf_new failed");
580 if ((r = sshbuf_put_u8(msg, type)) != 0 ||
581 (r = sshbuf_put_u32(msg, id)) != 0 ||
582 (r = sshbuf_put_string(msg, data, dlen)) != 0)
583 fatal_fr(r, "compose");
584 send_msg(msg);
585 sshbuf_free(msg);
586 }
587
588 static void
send_data(uint32_t id,const u_char * data,int dlen)589 send_data(uint32_t id, const u_char *data, int dlen)
590 {
591 debug("request %u: sent data len %d", id, dlen);
592 send_data_or_handle(SSH2_FXP_DATA, id, data, dlen);
593 }
594
595 static void
send_handle(uint32_t id,int handle)596 send_handle(uint32_t id, int handle)
597 {
598 u_char *string;
599 int hlen;
600
601 handle_to_string(handle, &string, &hlen);
602 debug("request %u: sent handle %d", id, handle);
603 send_data_or_handle(SSH2_FXP_HANDLE, id, string, hlen);
604 free(string);
605 }
606
607 static void
send_names(uint32_t id,int count,const Stat * stats)608 send_names(uint32_t id, int count, const Stat *stats)
609 {
610 struct sshbuf *msg;
611 int i, r;
612
613 if ((msg = sshbuf_new()) == NULL)
614 fatal_f("sshbuf_new failed");
615 if ((r = sshbuf_put_u8(msg, SSH2_FXP_NAME)) != 0 ||
616 (r = sshbuf_put_u32(msg, id)) != 0 ||
617 (r = sshbuf_put_u32(msg, count)) != 0)
618 fatal_fr(r, "compose");
619 debug("request %u: sent names count %d", id, count);
620 for (i = 0; i < count; i++) {
621 if ((r = sshbuf_put_cstring(msg, stats[i].name)) != 0 ||
622 (r = sshbuf_put_cstring(msg, stats[i].long_name)) != 0 ||
623 (r = encode_attrib(msg, &stats[i].attrib)) != 0)
624 fatal_fr(r, "compose filenames/attrib");
625 }
626 send_msg(msg);
627 sshbuf_free(msg);
628 }
629
630 static void
send_attrib(uint32_t id,const Attrib * a)631 send_attrib(uint32_t id, const Attrib *a)
632 {
633 struct sshbuf *msg;
634 int r;
635
636 debug("request %u: sent attrib have 0x%x", id, a->flags);
637 if ((msg = sshbuf_new()) == NULL)
638 fatal_f("sshbuf_new failed");
639 if ((r = sshbuf_put_u8(msg, SSH2_FXP_ATTRS)) != 0 ||
640 (r = sshbuf_put_u32(msg, id)) != 0 ||
641 (r = encode_attrib(msg, a)) != 0)
642 fatal_fr(r, "compose");
643 send_msg(msg);
644 sshbuf_free(msg);
645 }
646
647 static void
send_statvfs(uint32_t id,struct statvfs * st)648 send_statvfs(uint32_t id, struct statvfs *st)
649 {
650 struct sshbuf *msg;
651 uint64_t flag;
652 int r;
653
654 flag = (st->f_flag & ST_RDONLY) ? SSH2_FXE_STATVFS_ST_RDONLY : 0;
655 flag |= (st->f_flag & ST_NOSUID) ? SSH2_FXE_STATVFS_ST_NOSUID : 0;
656
657 if ((msg = sshbuf_new()) == NULL)
658 fatal_f("sshbuf_new failed");
659 if ((r = sshbuf_put_u8(msg, SSH2_FXP_EXTENDED_REPLY)) != 0 ||
660 (r = sshbuf_put_u32(msg, id)) != 0 ||
661 (r = sshbuf_put_u64(msg, st->f_bsize)) != 0 ||
662 (r = sshbuf_put_u64(msg, st->f_frsize)) != 0 ||
663 (r = sshbuf_put_u64(msg, st->f_blocks)) != 0 ||
664 (r = sshbuf_put_u64(msg, st->f_bfree)) != 0 ||
665 (r = sshbuf_put_u64(msg, st->f_bavail)) != 0 ||
666 (r = sshbuf_put_u64(msg, st->f_files)) != 0 ||
667 (r = sshbuf_put_u64(msg, st->f_ffree)) != 0 ||
668 (r = sshbuf_put_u64(msg, st->f_favail)) != 0 ||
669 (r = sshbuf_put_u64(msg, FSID_TO_ULONG(st->f_fsid))) != 0 ||
670 (r = sshbuf_put_u64(msg, flag)) != 0 ||
671 (r = sshbuf_put_u64(msg, st->f_namemax)) != 0)
672 fatal_fr(r, "compose");
673 send_msg(msg);
674 sshbuf_free(msg);
675 }
676
677 /*
678 * Prepare SSH2_FXP_VERSION extension advertisement for a single extension.
679 * The extension is checked for permission prior to advertisement.
680 */
681 static int
compose_extension(struct sshbuf * msg,const char * name,const char * ver)682 compose_extension(struct sshbuf *msg, const char *name, const char *ver)
683 {
684 int r;
685 const struct sftp_handler *exthnd;
686
687 if ((exthnd = extended_handler_byname(name)) == NULL)
688 fatal_f("internal error: no handler for %s", name);
689 if (!request_permitted(exthnd)) {
690 debug2_f("refusing to advertise disallowed extension %s", name);
691 return 0;
692 }
693 if ((r = sshbuf_put_cstring(msg, name)) != 0 ||
694 (r = sshbuf_put_cstring(msg, ver)) != 0)
695 fatal_fr(r, "compose %s", name);
696 return 0;
697 }
698
699 /* parse incoming */
700
701 static void
process_init(void)702 process_init(void)
703 {
704 struct sshbuf *msg;
705 int r;
706
707 if ((r = sshbuf_get_u32(iqueue, &version)) != 0)
708 fatal_fr(r, "parse");
709 verbose("received client version %u", version);
710 if ((msg = sshbuf_new()) == NULL)
711 fatal_f("sshbuf_new failed");
712 if ((r = sshbuf_put_u8(msg, SSH2_FXP_VERSION)) != 0 ||
713 (r = sshbuf_put_u32(msg, SSH2_FILEXFER_VERSION)) != 0)
714 fatal_fr(r, "compose");
715
716 /* extension advertisements */
717 compose_extension(msg, "posix-rename@openssh.com", "1");
718 compose_extension(msg, "statvfs@openssh.com", "2");
719 compose_extension(msg, "fstatvfs@openssh.com", "2");
720 compose_extension(msg, "hardlink@openssh.com", "1");
721 compose_extension(msg, "fsync@openssh.com", "1");
722 compose_extension(msg, "lsetstat@openssh.com", "1");
723 compose_extension(msg, "limits@openssh.com", "1");
724 compose_extension(msg, "expand-path@openssh.com", "1");
725 compose_extension(msg, "copy-data", "1");
726 compose_extension(msg, "home-directory", "1");
727 compose_extension(msg, "users-groups-by-id@openssh.com", "1");
728
729 send_msg(msg);
730 sshbuf_free(msg);
731 }
732
733 static void
process_open(uint32_t id)734 process_open(uint32_t id)
735 {
736 uint32_t pflags;
737 Attrib a;
738 char *name;
739 int r, handle, fd, flags, mode, status = SSH2_FX_FAILURE;
740
741 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
742 (r = sshbuf_get_u32(iqueue, &pflags)) != 0 || /* portable flags */
743 (r = decode_attrib(iqueue, &a)) != 0)
744 fatal_fr(r, "parse");
745
746 debug3("request %u: open flags %d", id, pflags);
747 flags = flags_from_portable(pflags);
748 mode = (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? a.perm : 0666;
749 logit("open \"%s\" flags %s mode 0%o",
750 name, string_from_portable(pflags), mode);
751 if (readonly &&
752 ((flags & O_ACCMODE) != O_RDONLY ||
753 (flags & (O_CREAT|O_TRUNC)) != 0)) {
754 verbose("Refusing open request in read-only mode");
755 status = SSH2_FX_PERMISSION_DENIED;
756 } else {
757 fd = open(name, flags, mode);
758 if (fd == -1) {
759 status = errno_to_portable(errno);
760 } else {
761 handle = handle_new(HANDLE_FILE, name, fd, flags, NULL);
762 if (handle < 0) {
763 close(fd);
764 } else {
765 send_handle(id, handle);
766 status = SSH2_FX_OK;
767 }
768 }
769 }
770 if (status != SSH2_FX_OK)
771 send_status(id, status);
772 free(name);
773 }
774
775 static void
process_close(uint32_t id)776 process_close(uint32_t id)
777 {
778 int r, handle, ret, status = SSH2_FX_FAILURE;
779
780 if ((r = get_handle(iqueue, &handle)) != 0)
781 fatal_fr(r, "parse");
782
783 debug3("request %u: close handle %u", id, handle);
784 handle_log_close(handle, NULL);
785 ret = handle_close(handle);
786 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
787 send_status(id, status);
788 }
789
790 static void
process_read(uint32_t id)791 process_read(uint32_t id)
792 {
793 static u_char *buf;
794 static size_t buflen;
795 uint32_t len;
796 int r, handle, fd, ret, status = SSH2_FX_FAILURE;
797 uint64_t off;
798
799 if ((r = get_handle(iqueue, &handle)) != 0 ||
800 (r = sshbuf_get_u64(iqueue, &off)) != 0 ||
801 (r = sshbuf_get_u32(iqueue, &len)) != 0)
802 fatal_fr(r, "parse");
803
804 debug("request %u: read \"%s\" (handle %d) off %llu len %u",
805 id, handle_to_name(handle), handle, (unsigned long long)off, len);
806 if ((fd = handle_to_fd(handle)) == -1)
807 goto out;
808 if (len > SFTP_MAX_READ_LENGTH) {
809 debug2("read change len %u to %u", len, SFTP_MAX_READ_LENGTH);
810 len = SFTP_MAX_READ_LENGTH;
811 }
812 if (len > buflen) {
813 debug3_f("allocate %zu => %u", buflen, len);
814 if ((buf = realloc(buf, len)) == NULL)
815 fatal_f("realloc failed");
816 buflen = len;
817 }
818 if (lseek(fd, off, SEEK_SET) == -1) {
819 status = errno_to_portable(errno);
820 error_f("seek \"%.100s\": %s", handle_to_name(handle),
821 strerror(errno));
822 goto out;
823 }
824 if (len == 0) {
825 /* weird, but not strictly disallowed */
826 ret = 0;
827 } else if ((ret = read(fd, buf, len)) == -1) {
828 status = errno_to_portable(errno);
829 error_f("read \"%.100s\": %s", handle_to_name(handle),
830 strerror(errno));
831 goto out;
832 } else if (ret == 0) {
833 status = SSH2_FX_EOF;
834 goto out;
835 }
836 send_data(id, buf, ret);
837 handle_update_read(handle, ret);
838 /* success */
839 status = SSH2_FX_OK;
840 out:
841 if (status != SSH2_FX_OK)
842 send_status(id, status);
843 }
844
845 static void
process_write(uint32_t id)846 process_write(uint32_t id)
847 {
848 uint64_t off;
849 size_t len;
850 int r, handle, fd, ret, status;
851 u_char *data;
852
853 if ((r = get_handle(iqueue, &handle)) != 0 ||
854 (r = sshbuf_get_u64(iqueue, &off)) != 0 ||
855 (r = sshbuf_get_string(iqueue, &data, &len)) != 0)
856 fatal_fr(r, "parse");
857
858 debug("request %u: write \"%s\" (handle %d) off %llu len %zu",
859 id, handle_to_name(handle), handle, (unsigned long long)off, len);
860 fd = handle_to_fd(handle);
861
862 if (fd < 0)
863 status = SSH2_FX_FAILURE;
864 else {
865 if (!(handle_to_flags(handle) & O_APPEND) &&
866 lseek(fd, off, SEEK_SET) == -1) {
867 status = errno_to_portable(errno);
868 error_f("seek \"%.100s\": %s", handle_to_name(handle),
869 strerror(errno));
870 } else {
871 /* XXX ATOMICIO ? */
872 ret = write(fd, data, len);
873 if (ret == -1) {
874 status = errno_to_portable(errno);
875 error_f("write \"%.100s\": %s",
876 handle_to_name(handle), strerror(errno));
877 } else if ((size_t)ret == len) {
878 status = SSH2_FX_OK;
879 handle_update_write(handle, ret);
880 } else {
881 debug2_f("nothing at all written");
882 status = SSH2_FX_FAILURE;
883 }
884 }
885 }
886 send_status(id, status);
887 free(data);
888 }
889
890 static void
process_do_stat(uint32_t id,int do_lstat)891 process_do_stat(uint32_t id, int do_lstat)
892 {
893 Attrib a;
894 struct stat st;
895 char *name;
896 int r, status = SSH2_FX_FAILURE;
897
898 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
899 fatal_fr(r, "parse");
900
901 debug3("request %u: %sstat", id, do_lstat ? "l" : "");
902 verbose("%sstat name \"%s\"", do_lstat ? "l" : "", name);
903 r = do_lstat ? lstat(name, &st) : stat(name, &st);
904 if (r == -1) {
905 status = errno_to_portable(errno);
906 } else {
907 stat_to_attrib(&st, &a);
908 send_attrib(id, &a);
909 status = SSH2_FX_OK;
910 }
911 if (status != SSH2_FX_OK)
912 send_status(id, status);
913 free(name);
914 }
915
916 static void
process_stat(uint32_t id)917 process_stat(uint32_t id)
918 {
919 process_do_stat(id, 0);
920 }
921
922 static void
process_lstat(uint32_t id)923 process_lstat(uint32_t id)
924 {
925 process_do_stat(id, 1);
926 }
927
928 static void
process_fstat(uint32_t id)929 process_fstat(uint32_t id)
930 {
931 Attrib a;
932 struct stat st;
933 int fd, r, handle, status = SSH2_FX_FAILURE;
934
935 if ((r = get_handle(iqueue, &handle)) != 0)
936 fatal_fr(r, "parse");
937 debug("request %u: fstat \"%s\" (handle %u)",
938 id, handle_to_name(handle), handle);
939 fd = handle_to_fd(handle);
940 if (fd >= 0) {
941 r = fstat(fd, &st);
942 if (r == -1) {
943 status = errno_to_portable(errno);
944 } else {
945 stat_to_attrib(&st, &a);
946 send_attrib(id, &a);
947 status = SSH2_FX_OK;
948 }
949 }
950 if (status != SSH2_FX_OK)
951 send_status(id, status);
952 }
953
954 static struct timeval *
attrib_to_tv(const Attrib * a)955 attrib_to_tv(const Attrib *a)
956 {
957 static struct timeval tv[2];
958
959 tv[0].tv_sec = a->atime;
960 tv[0].tv_usec = 0;
961 tv[1].tv_sec = a->mtime;
962 tv[1].tv_usec = 0;
963 return tv;
964 }
965
966 static struct timespec *
attrib_to_ts(const Attrib * a)967 attrib_to_ts(const Attrib *a)
968 {
969 static struct timespec ts[2];
970
971 ts[0].tv_sec = a->atime;
972 ts[0].tv_nsec = 0;
973 ts[1].tv_sec = a->mtime;
974 ts[1].tv_nsec = 0;
975 return ts;
976 }
977
978 static void
process_setstat(uint32_t id)979 process_setstat(uint32_t id)
980 {
981 Attrib a;
982 char *name;
983 int r, status = SSH2_FX_OK;
984
985 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
986 (r = decode_attrib(iqueue, &a)) != 0)
987 fatal_fr(r, "parse");
988
989 debug("request %u: setstat name \"%s\"", id, name);
990 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) {
991 logit("set \"%s\" size %llu",
992 name, (unsigned long long)a.size);
993 r = truncate(name, a.size);
994 if (r == -1)
995 status = errno_to_portable(errno);
996 }
997 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
998 logit("set \"%s\" mode %04o", name, a.perm);
999 r = chmod(name, a.perm & 07777);
1000 if (r == -1)
1001 status = errno_to_portable(errno);
1002 }
1003 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
1004 char buf[64];
1005 time_t t = a.mtime;
1006
1007 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
1008 localtime(&t));
1009 logit("set \"%s\" modtime %s", name, buf);
1010 r = utimes(name, attrib_to_tv(&a));
1011 if (r == -1)
1012 status = errno_to_portable(errno);
1013 }
1014 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) {
1015 logit("set \"%s\" owner %lu group %lu", name,
1016 (u_long)a.uid, (u_long)a.gid);
1017 r = chown(name, a.uid, a.gid);
1018 if (r == -1)
1019 status = errno_to_portable(errno);
1020 }
1021 send_status(id, status);
1022 free(name);
1023 }
1024
1025 static void
process_fsetstat(uint32_t id)1026 process_fsetstat(uint32_t id)
1027 {
1028 Attrib a;
1029 int handle, fd, r;
1030 int status = SSH2_FX_OK;
1031
1032 if ((r = get_handle(iqueue, &handle)) != 0 ||
1033 (r = decode_attrib(iqueue, &a)) != 0)
1034 fatal_fr(r, "parse");
1035
1036 debug("request %u: fsetstat handle %d", id, handle);
1037 fd = handle_to_fd(handle);
1038 if (fd < 0)
1039 status = SSH2_FX_FAILURE;
1040 else {
1041 char *name = handle_to_name(handle);
1042
1043 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) {
1044 logit("set \"%s\" size %llu",
1045 name, (unsigned long long)a.size);
1046 r = ftruncate(fd, a.size);
1047 if (r == -1)
1048 status = errno_to_portable(errno);
1049 }
1050 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
1051 logit("set \"%s\" mode %04o", name, a.perm);
1052 #ifdef HAVE_FCHMOD
1053 r = fchmod(fd, a.perm & 07777);
1054 #else
1055 r = chmod(name, a.perm & 07777);
1056 #endif
1057 if (r == -1)
1058 status = errno_to_portable(errno);
1059 }
1060 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
1061 char buf[64];
1062 time_t t = a.mtime;
1063
1064 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
1065 localtime(&t));
1066 logit("set \"%s\" modtime %s", name, buf);
1067 #ifdef HAVE_FUTIMES
1068 r = futimes(fd, attrib_to_tv(&a));
1069 #else
1070 r = utimes(name, attrib_to_tv(&a));
1071 #endif
1072 if (r == -1)
1073 status = errno_to_portable(errno);
1074 }
1075 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) {
1076 logit("set \"%s\" owner %lu group %lu", name,
1077 (u_long)a.uid, (u_long)a.gid);
1078 #ifdef HAVE_FCHOWN
1079 r = fchown(fd, a.uid, a.gid);
1080 #else
1081 r = chown(name, a.uid, a.gid);
1082 #endif
1083 if (r == -1)
1084 status = errno_to_portable(errno);
1085 }
1086 }
1087 send_status(id, status);
1088 }
1089
1090 static void
process_opendir(uint32_t id)1091 process_opendir(uint32_t id)
1092 {
1093 DIR *dirp = NULL;
1094 char *path;
1095 int r, handle, status = SSH2_FX_FAILURE;
1096
1097 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1098 fatal_fr(r, "parse");
1099
1100 debug3("request %u: opendir", id);
1101 logit("opendir \"%s\"", path);
1102 dirp = opendir(path);
1103 if (dirp == NULL) {
1104 status = errno_to_portable(errno);
1105 } else {
1106 handle = handle_new(HANDLE_DIR, path, 0, 0, dirp);
1107 if (handle < 0) {
1108 closedir(dirp);
1109 } else {
1110 send_handle(id, handle);
1111 status = SSH2_FX_OK;
1112 }
1113
1114 }
1115 if (status != SSH2_FX_OK)
1116 send_status(id, status);
1117 free(path);
1118 }
1119
1120 static void
process_readdir(uint32_t id)1121 process_readdir(uint32_t id)
1122 {
1123 DIR *dirp;
1124 struct dirent *dp;
1125 char *path;
1126 int r, handle;
1127
1128 if ((r = get_handle(iqueue, &handle)) != 0)
1129 fatal_fr(r, "parse");
1130
1131 debug("request %u: readdir \"%s\" (handle %d)", id,
1132 handle_to_name(handle), handle);
1133 dirp = handle_to_dir(handle);
1134 path = handle_to_name(handle);
1135 if (dirp == NULL || path == NULL) {
1136 send_status(id, SSH2_FX_FAILURE);
1137 } else {
1138 struct stat st;
1139 char *pathname;
1140 Stat *stats;
1141 int nstats = 10, count = 0, i;
1142
1143 stats = xcalloc(nstats, sizeof(Stat));
1144 while ((dp = readdir(dirp)) != NULL) {
1145 if (count >= nstats) {
1146 nstats *= 2;
1147 stats = xreallocarray(stats, nstats, sizeof(Stat));
1148 }
1149 xasprintf(&pathname, "%s%s%s", path,
1150 strcmp(path, "/") ? "/" : "", dp->d_name);
1151 r = lstat(pathname, &st);
1152 free(pathname);
1153 if (r == -1)
1154 continue;
1155 stat_to_attrib(&st, &(stats[count].attrib));
1156 stats[count].name = xstrdup(dp->d_name);
1157 stats[count].long_name = ls_file(dp->d_name, &st,
1158 0, 0, NULL, NULL);
1159 count++;
1160 /* send up to 100 entries in one message */
1161 /* XXX check packet size instead */
1162 if (count == 100)
1163 break;
1164 }
1165 if (count > 0) {
1166 send_names(id, count, stats);
1167 for (i = 0; i < count; i++) {
1168 free(stats[i].name);
1169 free(stats[i].long_name);
1170 }
1171 } else {
1172 send_status(id, SSH2_FX_EOF);
1173 }
1174 free(stats);
1175 }
1176 }
1177
1178 static void
process_remove(uint32_t id)1179 process_remove(uint32_t id)
1180 {
1181 char *name;
1182 int r, status = SSH2_FX_FAILURE;
1183
1184 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
1185 fatal_fr(r, "parse");
1186
1187 debug3("request %u: remove", id);
1188 logit("remove name \"%s\"", name);
1189 r = unlink(name);
1190 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1191 send_status(id, status);
1192 free(name);
1193 }
1194
1195 static void
process_mkdir(uint32_t id)1196 process_mkdir(uint32_t id)
1197 {
1198 Attrib a;
1199 char *name;
1200 int r, mode, status = SSH2_FX_FAILURE;
1201
1202 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
1203 (r = decode_attrib(iqueue, &a)) != 0)
1204 fatal_fr(r, "parse");
1205
1206 mode = (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ?
1207 a.perm & 07777 : 0777;
1208 debug3("request %u: mkdir", id);
1209 logit("mkdir name \"%s\" mode 0%o", name, mode);
1210 r = mkdir(name, mode);
1211 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1212 send_status(id, status);
1213 free(name);
1214 }
1215
1216 static void
process_rmdir(uint32_t id)1217 process_rmdir(uint32_t id)
1218 {
1219 char *name;
1220 int r, status;
1221
1222 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
1223 fatal_fr(r, "parse");
1224
1225 debug3("request %u: rmdir", id);
1226 logit("rmdir name \"%s\"", name);
1227 r = rmdir(name);
1228 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1229 send_status(id, status);
1230 free(name);
1231 }
1232
1233 static void
process_realpath(uint32_t id)1234 process_realpath(uint32_t id)
1235 {
1236 char resolvedname[PATH_MAX];
1237 char *path;
1238 int r;
1239
1240 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1241 fatal_fr(r, "parse");
1242
1243 if (path[0] == '\0') {
1244 free(path);
1245 path = xstrdup(".");
1246 }
1247 debug3("request %u: realpath", id);
1248 verbose("realpath \"%s\"", path);
1249 if (sftp_realpath(path, resolvedname) == NULL) {
1250 send_status(id, errno_to_portable(errno));
1251 } else {
1252 Stat s;
1253 attrib_clear(&s.attrib);
1254 s.name = s.long_name = resolvedname;
1255 send_names(id, 1, &s);
1256 }
1257 free(path);
1258 }
1259
1260 static void
process_rename(uint32_t id)1261 process_rename(uint32_t id)
1262 {
1263 char *oldpath, *newpath;
1264 int r, status;
1265 struct stat sb;
1266
1267 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
1268 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
1269 fatal_fr(r, "parse");
1270
1271 debug3("request %u: rename", id);
1272 logit("rename old \"%s\" new \"%s\"", oldpath, newpath);
1273 status = SSH2_FX_FAILURE;
1274 if (lstat(oldpath, &sb) == -1)
1275 status = errno_to_portable(errno);
1276 else if (S_ISREG(sb.st_mode)) {
1277 /* Race-free rename of regular files */
1278 if (link(oldpath, newpath) == -1) {
1279 if (errno == EOPNOTSUPP || errno == ENOSYS
1280 #ifdef EXDEV
1281 || errno == EXDEV
1282 #endif
1283 #ifdef LINK_OPNOTSUPP_ERRNO
1284 || errno == LINK_OPNOTSUPP_ERRNO
1285 #endif
1286 ) {
1287 struct stat st;
1288
1289 /*
1290 * fs doesn't support links, so fall back to
1291 * stat+rename. This is racy.
1292 */
1293 if (stat(newpath, &st) == -1) {
1294 if (rename(oldpath, newpath) == -1)
1295 status =
1296 errno_to_portable(errno);
1297 else
1298 status = SSH2_FX_OK;
1299 }
1300 } else {
1301 status = errno_to_portable(errno);
1302 }
1303 } else if (unlink(oldpath) == -1) {
1304 status = errno_to_portable(errno);
1305 /* clean spare link */
1306 unlink(newpath);
1307 } else
1308 status = SSH2_FX_OK;
1309 } else if (stat(newpath, &sb) == -1) {
1310 if (rename(oldpath, newpath) == -1)
1311 status = errno_to_portable(errno);
1312 else
1313 status = SSH2_FX_OK;
1314 }
1315 send_status(id, status);
1316 free(oldpath);
1317 free(newpath);
1318 }
1319
1320 static void
process_readlink(uint32_t id)1321 process_readlink(uint32_t id)
1322 {
1323 int r, len;
1324 char buf[PATH_MAX];
1325 char *path;
1326
1327 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1328 fatal_fr(r, "parse");
1329
1330 debug3("request %u: readlink", id);
1331 verbose("readlink \"%s\"", path);
1332 if ((len = readlink(path, buf, sizeof(buf) - 1)) == -1)
1333 send_status(id, errno_to_portable(errno));
1334 else {
1335 Stat s;
1336
1337 buf[len] = '\0';
1338 attrib_clear(&s.attrib);
1339 s.name = s.long_name = buf;
1340 send_names(id, 1, &s);
1341 }
1342 free(path);
1343 }
1344
1345 static void
process_symlink(uint32_t id)1346 process_symlink(uint32_t id)
1347 {
1348 char *oldpath, *newpath;
1349 int r, status;
1350
1351 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
1352 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
1353 fatal_fr(r, "parse");
1354
1355 debug3("request %u: symlink", id);
1356 logit("symlink old \"%s\" new \"%s\"", oldpath, newpath);
1357 /* this will fail if 'newpath' exists */
1358 r = symlink(oldpath, newpath);
1359 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1360 send_status(id, status);
1361 free(oldpath);
1362 free(newpath);
1363 }
1364
1365 static void
process_extended_posix_rename(uint32_t id)1366 process_extended_posix_rename(uint32_t id)
1367 {
1368 char *oldpath, *newpath;
1369 int r, status;
1370
1371 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
1372 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
1373 fatal_fr(r, "parse");
1374
1375 debug3("request %u: posix-rename", id);
1376 logit("posix-rename old \"%s\" new \"%s\"", oldpath, newpath);
1377 r = rename(oldpath, newpath);
1378 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1379 send_status(id, status);
1380 free(oldpath);
1381 free(newpath);
1382 }
1383
1384 static void
process_extended_statvfs(uint32_t id)1385 process_extended_statvfs(uint32_t id)
1386 {
1387 char *path;
1388 struct statvfs st;
1389 int r;
1390
1391 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1392 fatal_fr(r, "parse");
1393 debug3("request %u: statvfs", id);
1394 logit("statvfs \"%s\"", path);
1395
1396 if (statvfs(path, &st) != 0)
1397 send_status(id, errno_to_portable(errno));
1398 else
1399 send_statvfs(id, &st);
1400 free(path);
1401 }
1402
1403 static void
process_extended_fstatvfs(uint32_t id)1404 process_extended_fstatvfs(uint32_t id)
1405 {
1406 int r, handle, fd;
1407 struct statvfs st;
1408
1409 if ((r = get_handle(iqueue, &handle)) != 0)
1410 fatal_fr(r, "parse");
1411 debug("request %u: fstatvfs \"%s\" (handle %u)",
1412 id, handle_to_name(handle), handle);
1413 if ((fd = handle_to_fd(handle)) < 0) {
1414 send_status(id, SSH2_FX_FAILURE);
1415 return;
1416 }
1417 if (fstatvfs(fd, &st) != 0)
1418 send_status(id, errno_to_portable(errno));
1419 else
1420 send_statvfs(id, &st);
1421 }
1422
1423 static void
process_extended_hardlink(uint32_t id)1424 process_extended_hardlink(uint32_t id)
1425 {
1426 char *oldpath, *newpath;
1427 int r, status;
1428
1429 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
1430 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
1431 fatal_fr(r, "parse");
1432
1433 debug3("request %u: hardlink", id);
1434 logit("hardlink old \"%s\" new \"%s\"", oldpath, newpath);
1435 r = link(oldpath, newpath);
1436 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1437 send_status(id, status);
1438 free(oldpath);
1439 free(newpath);
1440 }
1441
1442 static void
process_extended_fsync(uint32_t id)1443 process_extended_fsync(uint32_t id)
1444 {
1445 int handle, fd, r, status = SSH2_FX_OP_UNSUPPORTED;
1446
1447 if ((r = get_handle(iqueue, &handle)) != 0)
1448 fatal_fr(r, "parse");
1449 debug3("request %u: fsync (handle %u)", id, handle);
1450 verbose("fsync \"%s\"", handle_to_name(handle));
1451 if ((fd = handle_to_fd(handle)) < 0)
1452 status = SSH2_FX_NO_SUCH_FILE;
1453 else if (handle_is_ok(handle, HANDLE_FILE)) {
1454 r = fsync(fd);
1455 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1456 }
1457 send_status(id, status);
1458 }
1459
1460 static void
process_extended_lsetstat(uint32_t id)1461 process_extended_lsetstat(uint32_t id)
1462 {
1463 Attrib a;
1464 char *name;
1465 int r, status = SSH2_FX_OK;
1466
1467 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
1468 (r = decode_attrib(iqueue, &a)) != 0)
1469 fatal_fr(r, "parse");
1470
1471 debug("request %u: lsetstat name \"%s\"", id, name);
1472 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) {
1473 /* nonsensical for links */
1474 status = SSH2_FX_BAD_MESSAGE;
1475 goto out;
1476 }
1477 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
1478 logit("set \"%s\" mode %04o", name, a.perm);
1479 r = fchmodat(AT_FDCWD, name,
1480 a.perm & 07777, AT_SYMLINK_NOFOLLOW);
1481 if (r == -1)
1482 status = errno_to_portable(errno);
1483 }
1484 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
1485 char buf[64];
1486 time_t t = a.mtime;
1487
1488 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
1489 localtime(&t));
1490 logit("set \"%s\" modtime %s", name, buf);
1491 r = utimensat(AT_FDCWD, name,
1492 attrib_to_ts(&a), AT_SYMLINK_NOFOLLOW);
1493 if (r == -1)
1494 status = errno_to_portable(errno);
1495 }
1496 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) {
1497 logit("set \"%s\" owner %lu group %lu", name,
1498 (u_long)a.uid, (u_long)a.gid);
1499 r = fchownat(AT_FDCWD, name, a.uid, a.gid,
1500 AT_SYMLINK_NOFOLLOW);
1501 if (r == -1)
1502 status = errno_to_portable(errno);
1503 }
1504 out:
1505 send_status(id, status);
1506 free(name);
1507 }
1508
1509 static void
process_extended_limits(uint32_t id)1510 process_extended_limits(uint32_t id)
1511 {
1512 struct sshbuf *msg;
1513 int r;
1514 uint64_t nfiles = 0;
1515 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
1516 struct rlimit rlim;
1517 #endif
1518
1519 debug("request %u: limits", id);
1520
1521 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
1522 if (getrlimit(RLIMIT_NOFILE, &rlim) != -1 && rlim.rlim_cur > 5)
1523 nfiles = rlim.rlim_cur - 5; /* stdio(3) + syslog + spare */
1524 #endif
1525
1526 if ((msg = sshbuf_new()) == NULL)
1527 fatal_f("sshbuf_new failed");
1528 if ((r = sshbuf_put_u8(msg, SSH2_FXP_EXTENDED_REPLY)) != 0 ||
1529 (r = sshbuf_put_u32(msg, id)) != 0 ||
1530 /* max-packet-length */
1531 (r = sshbuf_put_u64(msg, SFTP_MAX_MSG_LENGTH)) != 0 ||
1532 /* max-read-length */
1533 (r = sshbuf_put_u64(msg, SFTP_MAX_READ_LENGTH)) != 0 ||
1534 /* max-write-length */
1535 (r = sshbuf_put_u64(msg, SFTP_MAX_MSG_LENGTH - 1024)) != 0 ||
1536 /* max-open-handles */
1537 (r = sshbuf_put_u64(msg, nfiles)) != 0)
1538 fatal_fr(r, "compose");
1539 send_msg(msg);
1540 sshbuf_free(msg);
1541 }
1542
1543 static void
process_extended_expand(uint32_t id)1544 process_extended_expand(uint32_t id)
1545 {
1546 char cwd[PATH_MAX], resolvedname[PATH_MAX];
1547 char *path, *npath;
1548 int r;
1549 Stat s;
1550
1551 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1552 fatal_fr(r, "parse");
1553 if (getcwd(cwd, sizeof(cwd)) == NULL) {
1554 send_status(id, errno_to_portable(errno));
1555 goto out;
1556 }
1557
1558 debug3("request %u: expand, original \"%s\"", id, path);
1559 if (path[0] == '\0') {
1560 /* empty path */
1561 free(path);
1562 path = xstrdup(".");
1563 } else if (*path == '~') {
1564 /* ~ expand path */
1565 /* Special-case for "~" and "~/" to respect homedir flag */
1566 if (strcmp(path, "~") == 0) {
1567 free(path);
1568 path = xstrdup(cwd);
1569 } else if (strncmp(path, "~/", 2) == 0) {
1570 npath = xstrdup(path + 2);
1571 free(path);
1572 xasprintf(&path, "%s/%s", cwd, npath);
1573 free(npath);
1574 } else {
1575 /* ~user expansions */
1576 if (tilde_expand(path, pw->pw_uid, &npath) != 0) {
1577 send_status_errmsg(id,
1578 errno_to_portable(ENOENT), "no such user");
1579 goto out;
1580 }
1581 free(path);
1582 path = npath;
1583 }
1584 } else if (*path != '/') {
1585 /* relative path */
1586 xasprintf(&npath, "%s/%s", cwd, path);
1587 free(path);
1588 path = npath;
1589 }
1590 verbose("expand \"%s\"", path);
1591 if (sftp_realpath(path, resolvedname) == NULL) {
1592 send_status(id, errno_to_portable(errno));
1593 goto out;
1594 }
1595 attrib_clear(&s.attrib);
1596 s.name = s.long_name = resolvedname;
1597 send_names(id, 1, &s);
1598 out:
1599 free(path);
1600 }
1601
1602 static void
process_extended_copy_data(uint32_t id)1603 process_extended_copy_data(uint32_t id)
1604 {
1605 u_char buf[64*1024];
1606 int read_handle, read_fd, write_handle, write_fd;
1607 uint64_t len, read_off, read_len, write_off;
1608 int r, copy_until_eof, status = SSH2_FX_OP_UNSUPPORTED;
1609 size_t ret;
1610 struct stat st_read, st_write;
1611
1612 if ((r = get_handle(iqueue, &read_handle)) != 0 ||
1613 (r = sshbuf_get_u64(iqueue, &read_off)) != 0 ||
1614 (r = sshbuf_get_u64(iqueue, &read_len)) != 0 ||
1615 (r = get_handle(iqueue, &write_handle)) != 0 ||
1616 (r = sshbuf_get_u64(iqueue, &write_off)) != 0)
1617 fatal_fr(r, "buffer error");
1618
1619 debug("request %u: copy-data from \"%s\" (handle %d) off %llu len %llu "
1620 "to \"%s\" (handle %d) off %llu",
1621 id, handle_to_name(read_handle), read_handle,
1622 (unsigned long long)read_off, (unsigned long long)read_len,
1623 handle_to_name(write_handle), write_handle,
1624 (unsigned long long)write_off);
1625
1626 /* For read length of 0, we read until EOF. */
1627 if (read_len == 0) {
1628 read_len = (uint64_t)-1 - read_off;
1629 copy_until_eof = 1;
1630 } else
1631 copy_until_eof = 0;
1632
1633 /* Disallow reading & writing to the same handle, path or inode */
1634 read_fd = handle_to_fd(read_handle);
1635 write_fd = handle_to_fd(write_handle);
1636 if (read_fd < 0 || write_fd < 0) {
1637 error_f("bad read or write fd");
1638 status = errno_to_portable(EBADF);
1639 goto out;
1640 }
1641 if (fstat(read_fd, &st_read) != 0) {
1642 status = errno_to_portable(errno);
1643 error_f("fstat read_fd failed: %s", strerror(errno));
1644 goto out;
1645 }
1646 if (fstat(write_fd, &st_write) != 0) {
1647 status = errno_to_portable(errno);
1648 error_f("fstat write_fd failed: %s", strerror(errno));
1649 goto out;
1650 }
1651 if (read_handle == write_handle ||
1652 !strcmp(handle_to_name(read_handle), handle_to_name(write_handle)) ||
1653 (st_read.st_dev != 0 && st_read.st_ino != 0 &&
1654 st_read.st_dev == st_write.st_dev &&
1655 st_read.st_ino == st_write.st_ino)) {
1656 error_f("refusing to read/write same file: "
1657 "read \"%s\" dev %lu ino %lu, write \"%s\" dev %lu ino %lu",
1658 handle_to_name(read_handle),
1659 (u_long)st_read.st_dev, (u_long)st_read.st_ino,
1660 handle_to_name(write_handle),
1661 (u_long)st_write.st_dev, (u_long)st_write.st_ino);
1662 status = SSH2_FX_FAILURE;
1663 goto out;
1664 }
1665
1666 if (lseek(read_fd, read_off, SEEK_SET) < 0) {
1667 status = errno_to_portable(errno);
1668 error_f("read_seek failed");
1669 goto out;
1670 }
1671
1672 if ((handle_to_flags(write_handle) & O_APPEND) == 0 &&
1673 lseek(write_fd, write_off, SEEK_SET) < 0) {
1674 status = errno_to_portable(errno);
1675 error_f("write_seek failed");
1676 goto out;
1677 }
1678
1679 /* Process the request in chunks. */
1680 while (read_len > 0 || copy_until_eof) {
1681 len = MINIMUM(sizeof(buf), read_len);
1682 read_len -= len;
1683
1684 ret = atomicio(read, read_fd, buf, len);
1685 if (ret == 0 && errno == EPIPE) {
1686 status = copy_until_eof ? SSH2_FX_OK : SSH2_FX_EOF;
1687 break;
1688 } else if (ret == 0) {
1689 status = errno_to_portable(errno);
1690 error_f("read failed: %s", strerror(errno));
1691 break;
1692 }
1693 len = ret;
1694 handle_update_read(read_handle, len);
1695
1696 ret = atomicio(vwrite, write_fd, buf, len);
1697 if (ret != len) {
1698 status = errno_to_portable(errno);
1699 error("%s: write failed: %llu != %llu: %s", __func__,
1700 (unsigned long long)ret, (unsigned long long)len,
1701 strerror(errno));
1702 break;
1703 }
1704 handle_update_write(write_handle, len);
1705 }
1706
1707 if (read_len == 0)
1708 status = SSH2_FX_OK;
1709
1710 out:
1711 send_status(id, status);
1712 }
1713
1714 static void
process_extended_home_directory(uint32_t id)1715 process_extended_home_directory(uint32_t id)
1716 {
1717 char *username;
1718 struct passwd *user_pw;
1719 int r;
1720 Stat s;
1721
1722 if ((r = sshbuf_get_cstring(iqueue, &username, NULL)) != 0)
1723 fatal_fr(r, "parse");
1724
1725 debug3("request %u: home-directory \"%s\"", id, username);
1726 if (username[0] == '\0') {
1727 user_pw = pw;
1728 } else if ((user_pw = getpwnam(username)) == NULL) {
1729 send_status(id, SSH2_FX_FAILURE);
1730 goto out;
1731 }
1732
1733 verbose("home-directory \"%s\"", user_pw->pw_dir);
1734 attrib_clear(&s.attrib);
1735 s.name = s.long_name = user_pw->pw_dir;
1736 send_names(id, 1, &s);
1737 out:
1738 free(username);
1739 }
1740
1741 static void
process_extended_get_users_groups_by_id(uint32_t id)1742 process_extended_get_users_groups_by_id(uint32_t id)
1743 {
1744 struct passwd *user_pw;
1745 struct group *gr;
1746 struct sshbuf *uids, *gids, *usernames, *groupnames, *msg;
1747 int r;
1748 u_int n, nusers = 0, ngroups = 0;
1749 const char *name;
1750
1751 if ((usernames = sshbuf_new()) == NULL ||
1752 (groupnames = sshbuf_new()) == NULL ||
1753 (msg = sshbuf_new()) == NULL)
1754 fatal_f("sshbuf_new failed");
1755 if ((r = sshbuf_froms(iqueue, &uids)) != 0 ||
1756 (r = sshbuf_froms(iqueue, &gids)) != 0)
1757 fatal_fr(r, "parse");
1758 debug_f("uids len = %zu, gids len = %zu",
1759 sshbuf_len(uids), sshbuf_len(gids));
1760 while (sshbuf_len(uids) != 0) {
1761 if ((r = sshbuf_get_u32(uids, &n)) != 0)
1762 fatal_fr(r, "parse inner uid");
1763 user_pw = getpwuid((uid_t)n);
1764 name = user_pw == NULL ? "" : user_pw->pw_name;
1765 debug3_f("uid %u => \"%s\"", n, name);
1766 if ((r = sshbuf_put_cstring(usernames, name)) != 0)
1767 fatal_fr(r, "assemble uid reply");
1768 nusers++;
1769 }
1770 while (sshbuf_len(gids) != 0) {
1771 if ((r = sshbuf_get_u32(gids, &n)) != 0)
1772 fatal_fr(r, "parse inner gid");
1773 gr = getgrgid((gid_t)n);
1774 name = gr == NULL ? "" : gr->gr_name;
1775 debug3_f("gid %u => \"%s\"", n, name);
1776 if ((r = sshbuf_put_cstring(groupnames, name)) != 0)
1777 fatal_fr(r, "assemble gid reply");
1778 ngroups++;
1779 }
1780 verbose("users-groups-by-id: %u users, %u groups", nusers, ngroups);
1781
1782 if ((r = sshbuf_put_u8(msg, SSH2_FXP_EXTENDED_REPLY)) != 0 ||
1783 (r = sshbuf_put_u32(msg, id)) != 0 ||
1784 (r = sshbuf_put_stringb(msg, usernames)) != 0 ||
1785 (r = sshbuf_put_stringb(msg, groupnames)) != 0)
1786 fatal_fr(r, "compose");
1787 send_msg(msg);
1788
1789 sshbuf_free(uids);
1790 sshbuf_free(gids);
1791 sshbuf_free(usernames);
1792 sshbuf_free(groupnames);
1793 sshbuf_free(msg);
1794 }
1795
1796 static void
process_extended(uint32_t id)1797 process_extended(uint32_t id)
1798 {
1799 char *request;
1800 int r;
1801 const struct sftp_handler *exthand;
1802
1803 if ((r = sshbuf_get_cstring(iqueue, &request, NULL)) != 0)
1804 fatal_fr(r, "parse");
1805 if ((exthand = extended_handler_byname(request)) == NULL) {
1806 error("Unknown extended request \"%.100s\"", request);
1807 send_status(id, SSH2_FX_OP_UNSUPPORTED); /* MUST */
1808 } else {
1809 if (!request_permitted(exthand))
1810 send_status(id, SSH2_FX_PERMISSION_DENIED);
1811 else
1812 exthand->handler(id);
1813 }
1814 free(request);
1815 }
1816
1817 /* stolen from ssh-agent */
1818
1819 static void
process(void)1820 process(void)
1821 {
1822 u_int msg_len;
1823 u_int buf_len;
1824 u_int consumed;
1825 u_char type;
1826 const u_char *cp;
1827 int i, r;
1828 uint32_t id;
1829
1830 buf_len = sshbuf_len(iqueue);
1831 if (buf_len < 5)
1832 return; /* Incomplete message. */
1833 cp = sshbuf_ptr(iqueue);
1834 msg_len = get_u32(cp);
1835 if (msg_len > SFTP_MAX_MSG_LENGTH) {
1836 error("bad message from %s local user %s",
1837 client_addr, pw->pw_name);
1838 sftp_server_cleanup_exit(11);
1839 }
1840 if (buf_len < msg_len + 4)
1841 return;
1842 if ((r = sshbuf_consume(iqueue, 4)) != 0)
1843 fatal_fr(r, "consume");
1844 buf_len -= 4;
1845 if ((r = sshbuf_get_u8(iqueue, &type)) != 0)
1846 fatal_fr(r, "parse type");
1847
1848 switch (type) {
1849 case SSH2_FXP_INIT:
1850 process_init();
1851 init_done = 1;
1852 break;
1853 case SSH2_FXP_EXTENDED:
1854 if (!init_done)
1855 fatal("Received extended request before init");
1856 if ((r = sshbuf_get_u32(iqueue, &id)) != 0)
1857 fatal_fr(r, "parse extended ID");
1858 process_extended(id);
1859 break;
1860 default:
1861 if (!init_done)
1862 fatal("Received %u request before init", type);
1863 if ((r = sshbuf_get_u32(iqueue, &id)) != 0)
1864 fatal_fr(r, "parse ID");
1865 for (i = 0; handlers[i].handler != NULL; i++) {
1866 if (type == handlers[i].type) {
1867 if (!request_permitted(&handlers[i])) {
1868 send_status(id,
1869 SSH2_FX_PERMISSION_DENIED);
1870 } else {
1871 handlers[i].handler(id);
1872 }
1873 break;
1874 }
1875 }
1876 if (handlers[i].handler == NULL)
1877 error("Unknown message %u", type);
1878 }
1879 /* discard the remaining bytes from the current packet */
1880 if (buf_len < sshbuf_len(iqueue)) {
1881 error("iqueue grew unexpectedly");
1882 sftp_server_cleanup_exit(255);
1883 }
1884 consumed = buf_len - sshbuf_len(iqueue);
1885 if (msg_len < consumed) {
1886 error("msg_len %u < consumed %u", msg_len, consumed);
1887 sftp_server_cleanup_exit(255);
1888 }
1889 if (msg_len > consumed &&
1890 (r = sshbuf_consume(iqueue, msg_len - consumed)) != 0)
1891 fatal_fr(r, "consume");
1892 }
1893
1894 /* Cleanup handler that logs active handles upon normal exit */
1895 void
sftp_server_cleanup_exit(int i)1896 sftp_server_cleanup_exit(int i)
1897 {
1898 if (pw != NULL && client_addr != NULL) {
1899 handle_log_exit();
1900 logit("session closed for local user %s from [%s]",
1901 pw->pw_name, client_addr);
1902 }
1903 _exit(i);
1904 }
1905
1906 static void
sftp_server_usage(void)1907 sftp_server_usage(void)
1908 {
1909 extern char *__progname;
1910
1911 fprintf(stderr,
1912 "usage: %s [-ehR] [-d start_directory] [-f log_facility] "
1913 "[-l log_level]\n\t[-P denied_requests] "
1914 "[-p allowed_requests] [-u umask]\n"
1915 " %s -Q protocol_feature\n",
1916 __progname, __progname);
1917 exit(1);
1918 }
1919
1920 int
sftp_server_main(int argc,char ** argv,struct passwd * user_pw)1921 sftp_server_main(int argc, char **argv, struct passwd *user_pw)
1922 {
1923 int i, r, in, out, ch, skipargs = 0, log_stderr = 0;
1924 ssize_t len, olen;
1925 SyslogFacility log_facility = SYSLOG_FACILITY_AUTH;
1926 char *cp, *homedir = NULL, uidstr[32], buf[4*4096];
1927 long mask;
1928
1929 extern char *optarg;
1930 extern char *__progname;
1931
1932 __progname = ssh_get_progname(argv[0]);
1933 log_init(__progname, log_level, log_facility, log_stderr);
1934
1935 pw = pwcopy(user_pw);
1936
1937 while (!skipargs && (ch = getopt(argc, argv,
1938 "d:f:l:P:p:Q:u:cehR")) != -1) {
1939 switch (ch) {
1940 case 'Q':
1941 if (strcasecmp(optarg, "requests") != 0) {
1942 fprintf(stderr, "Invalid query type\n");
1943 exit(1);
1944 }
1945 for (i = 0; handlers[i].handler != NULL; i++)
1946 printf("%s\n", handlers[i].name);
1947 for (i = 0; extended_handlers[i].handler != NULL; i++)
1948 printf("%s\n", extended_handlers[i].name);
1949 exit(0);
1950 break;
1951 case 'R':
1952 readonly = 1;
1953 break;
1954 case 'c':
1955 /*
1956 * Ignore all arguments if we are invoked as a
1957 * shell using "sftp-server -c command"
1958 */
1959 skipargs = 1;
1960 break;
1961 case 'e':
1962 log_stderr = 1;
1963 break;
1964 case 'l':
1965 log_level = log_level_number(optarg);
1966 if (log_level == SYSLOG_LEVEL_NOT_SET)
1967 error("Invalid log level \"%s\"", optarg);
1968 break;
1969 case 'f':
1970 log_facility = log_facility_number(optarg);
1971 if (log_facility == SYSLOG_FACILITY_NOT_SET)
1972 error("Invalid log facility \"%s\"", optarg);
1973 break;
1974 case 'd':
1975 cp = tilde_expand_filename(optarg, user_pw->pw_uid);
1976 snprintf(uidstr, sizeof(uidstr), "%llu",
1977 (unsigned long long)pw->pw_uid);
1978 homedir = percent_expand(cp, "d", user_pw->pw_dir,
1979 "u", user_pw->pw_name, "U", uidstr, (char *)NULL);
1980 free(cp);
1981 break;
1982 case 'p':
1983 if (request_allowlist != NULL)
1984 fatal("Permitted requests already set");
1985 request_allowlist = xstrdup(optarg);
1986 break;
1987 case 'P':
1988 if (request_denylist != NULL)
1989 fatal("Refused requests already set");
1990 request_denylist = xstrdup(optarg);
1991 break;
1992 case 'u':
1993 errno = 0;
1994 mask = strtol(optarg, &cp, 8);
1995 if (mask < 0 || mask > 0777 || *cp != '\0' ||
1996 cp == optarg || (mask == 0 && errno != 0))
1997 fatal("Invalid umask \"%s\"", optarg);
1998 (void)umask((mode_t)mask);
1999 break;
2000 case 'h':
2001 default:
2002 sftp_server_usage();
2003 }
2004 }
2005
2006 log_init(__progname, log_level, log_facility, log_stderr);
2007
2008 /*
2009 * On platforms where we can, avoid making /proc/self/{mem,maps}
2010 * available to the user so that sftp access doesn't automatically
2011 * imply arbitrary code execution access that will break
2012 * restricted configurations.
2013 */
2014 platform_disable_tracing(1); /* strict */
2015
2016 /* Drop any fine-grained privileges we don't need */
2017 platform_pledge_sftp_server();
2018
2019 if ((cp = getenv("SSH_CONNECTION")) != NULL) {
2020 client_addr = xstrdup(cp);
2021 if ((cp = strchr(client_addr, ' ')) == NULL) {
2022 error("Malformed SSH_CONNECTION variable: \"%s\"",
2023 getenv("SSH_CONNECTION"));
2024 sftp_server_cleanup_exit(255);
2025 }
2026 *cp = '\0';
2027 } else
2028 client_addr = xstrdup("UNKNOWN");
2029
2030 logit("session opened for local user %s from [%s]",
2031 pw->pw_name, client_addr);
2032
2033 in = STDIN_FILENO;
2034 out = STDOUT_FILENO;
2035
2036 #ifdef HAVE_CYGWIN
2037 setmode(in, O_BINARY);
2038 setmode(out, O_BINARY);
2039 #endif
2040
2041 if ((iqueue = sshbuf_new()) == NULL)
2042 fatal_f("sshbuf_new failed");
2043 if ((oqueue = sshbuf_new()) == NULL)
2044 fatal_f("sshbuf_new failed");
2045
2046 if (homedir != NULL) {
2047 if (chdir(homedir) != 0) {
2048 error("chdir to \"%s\" failed: %s", homedir,
2049 strerror(errno));
2050 }
2051 }
2052
2053 for (;;) {
2054 struct pollfd pfd[2];
2055
2056 memset(pfd, 0, sizeof pfd);
2057 pfd[0].fd = pfd[1].fd = -1;
2058
2059 /*
2060 * Ensure that we can read a full buffer and handle
2061 * the worst-case length packet it can generate,
2062 * otherwise apply backpressure by stopping reads.
2063 */
2064 if ((r = sshbuf_check_reserve(iqueue, sizeof(buf))) == 0 &&
2065 (r = sshbuf_check_reserve(oqueue,
2066 SFTP_MAX_MSG_LENGTH)) == 0) {
2067 pfd[0].fd = in;
2068 pfd[0].events = POLLIN;
2069 }
2070 else if (r != SSH_ERR_NO_BUFFER_SPACE)
2071 fatal_fr(r, "reserve");
2072
2073 olen = sshbuf_len(oqueue);
2074 if (olen > 0) {
2075 pfd[1].fd = out;
2076 pfd[1].events = POLLOUT;
2077 }
2078
2079 if (poll(pfd, 2, -1) == -1) {
2080 if (errno == EINTR)
2081 continue;
2082 error("poll: %s", strerror(errno));
2083 sftp_server_cleanup_exit(2);
2084 }
2085
2086 /* copy stdin to iqueue */
2087 if (pfd[0].revents & (POLLIN|POLLHUP)) {
2088 len = read(in, buf, sizeof buf);
2089 if (len == 0) {
2090 debug("read eof");
2091 sftp_server_cleanup_exit(0);
2092 } else if (len == -1) {
2093 if (errno != EAGAIN && errno != EINTR) {
2094 error("read: %s", strerror(errno));
2095 sftp_server_cleanup_exit(1);
2096 }
2097 } else if ((r = sshbuf_put(iqueue, buf, len)) != 0)
2098 fatal_fr(r, "sshbuf_put");
2099 }
2100 /* send oqueue to stdout */
2101 if (pfd[1].revents & (POLLOUT|POLLHUP)) {
2102 len = write(out, sshbuf_ptr(oqueue), olen);
2103 if (len == 0 || (len == -1 && errno == EPIPE)) {
2104 debug("write eof");
2105 sftp_server_cleanup_exit(0);
2106 } else if (len == -1) {
2107 sftp_server_cleanup_exit(1);
2108 if (errno != EAGAIN && errno != EINTR) {
2109 error("write: %s", strerror(errno));
2110 sftp_server_cleanup_exit(1);
2111 }
2112 } else if ((r = sshbuf_consume(oqueue, len)) != 0)
2113 fatal_fr(r, "consume");
2114 }
2115
2116 /*
2117 * Process requests from client if we can fit the results
2118 * into the output buffer, otherwise stop processing input
2119 * and let the output queue drain.
2120 */
2121 r = sshbuf_check_reserve(oqueue, SFTP_MAX_MSG_LENGTH);
2122 if (r == 0)
2123 process();
2124 else if (r != SSH_ERR_NO_BUFFER_SPACE)
2125 fatal_fr(r, "reserve");
2126 }
2127 }
2128