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libc/_collate_lookup: Fix segfault seen on ISO-8859-5 locales
[dragonfly.git] / crypto / openssh / sftp-server.c
blob0177130cfb17e71be47f71f74232ff8a84a3da70
1 /* $OpenBSD: sftp-server.c,v 1.103 2014/01/17 06:23:24 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/param.h>
22 #include <sys/stat.h>
23 #ifdef HAVE_SYS_TIME_H
24 # include <sys/time.h>
25 #endif
26 #ifdef HAVE_SYS_MOUNT_H
27 #include <sys/mount.h>
28 #endif
29 #ifdef HAVE_SYS_STATVFS_H
30 #include <sys/statvfs.h>
31 #endif
32 #ifdef HAVE_SYS_PRCTL_H
33 #include <sys/prctl.h>
34 #endif
35
36 #include <dirent.h>
37 #include <errno.h>
38 #include <fcntl.h>
39 #include <pwd.h>
40 #include <stdlib.h>
41 #include <stdio.h>
42 #include <string.h>
43 #include <pwd.h>
44 #include <time.h>
45 #include <unistd.h>
46 #include <stdarg.h>
47
48 #include "xmalloc.h"
49 #include "buffer.h"
50 #include "log.h"
51 #include "misc.h"
52 #include "match.h"
53 #include "uidswap.h"
54
55 #include "sftp.h"
56 #include "sftp-common.h"
57
58 /* helper */
59 #define get_int64() buffer_get_int64(&iqueue);
60 #define get_int() buffer_get_int(&iqueue);
61 #define get_string(lenp) buffer_get_string(&iqueue, lenp);
62
63 /* Our verbosity */
64 static LogLevel log_level = SYSLOG_LEVEL_ERROR;
65
66 /* Our client */
67 static struct passwd *pw = NULL;
68 static char *client_addr = NULL;
69
70 /* input and output queue */
71 static Buffer iqueue;
72 static Buffer oqueue;
73
74 /* Version of client */
75 static u_int version;
76
77 /* SSH2_FXP_INIT received */
78 static int init_done;
79
80 /* Disable writes */
81 static int readonly;
82
83 /* Requests that are allowed/denied */
84 static char *request_whitelist, *request_blacklist;
85
86 /* portable attributes, etc. */
87 typedef struct Stat Stat;
88
89 struct Stat {
90 char *name;
91 char *long_name;
92 Attrib attrib;
93 };
94
95 /* Packet handlers */
96 static void process_open(u_int32_t id);
97 static void process_close(u_int32_t id);
98 static void process_read(u_int32_t id);
99 static void process_write(u_int32_t id);
100 static void process_stat(u_int32_t id);
101 static void process_lstat(u_int32_t id);
102 static void process_fstat(u_int32_t id);
103 static void process_setstat(u_int32_t id);
104 static void process_fsetstat(u_int32_t id);
105 static void process_opendir(u_int32_t id);
106 static void process_readdir(u_int32_t id);
107 static void process_remove(u_int32_t id);
108 static void process_mkdir(u_int32_t id);
109 static void process_rmdir(u_int32_t id);
110 static void process_realpath(u_int32_t id);
111 static void process_rename(u_int32_t id);
112 static void process_readlink(u_int32_t id);
113 static void process_symlink(u_int32_t id);
114 static void process_extended_posix_rename(u_int32_t id);
115 static void process_extended_statvfs(u_int32_t id);
116 static void process_extended_fstatvfs(u_int32_t id);
117 static void process_extended_hardlink(u_int32_t id);
118 static void process_extended_fsync(u_int32_t id);
119 static void process_extended(u_int32_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)(u_int32_t);
126 int does_write; /* if nonzero, banned for readonly mode */
127 };
128
129 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 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 { NULL, NULL, 0, NULL, 0 }
161 };
162
163 static int
164 request_permitted(struct sftp_handler *h)
165 {
166 char *result;
167
168 if (readonly && h->does_write) {
169 verbose("Refusing %s request in read-only mode", h->name);
170 return 0;
171 }
172 if (request_blacklist != NULL &&
173 ((result = match_list(h->name, request_blacklist, NULL))) != NULL) {
174 free(result);
175 verbose("Refusing blacklisted %s request", h->name);
176 return 0;
177 }
178 if (request_whitelist != NULL &&
179 ((result = match_list(h->name, request_whitelist, NULL))) != NULL) {
180 free(result);
181 debug2("Permitting whitelisted %s request", h->name);
182 return 1;
183 }
184 if (request_whitelist != NULL) {
185 verbose("Refusing non-whitelisted %s request", h->name);
186 return 0;
187 }
188 return 1;
189 }
190
191 static int
192 errno_to_portable(int unixerrno)
193 {
194 int ret = 0;
195
196 switch (unixerrno) {
197 case 0:
198 ret = SSH2_FX_OK;
199 break;
200 case ENOENT:
201 case ENOTDIR:
202 case EBADF:
203 case ELOOP:
204 ret = SSH2_FX_NO_SUCH_FILE;
205 break;
206 case EPERM:
207 case EACCES:
208 case EFAULT:
209 ret = SSH2_FX_PERMISSION_DENIED;
210 break;
211 case ENAMETOOLONG:
212 case EINVAL:
213 ret = SSH2_FX_BAD_MESSAGE;
214 break;
215 case ENOSYS:
216 ret = SSH2_FX_OP_UNSUPPORTED;
217 break;
218 default:
219 ret = SSH2_FX_FAILURE;
220 break;
221 }
222 return ret;
223 }
224
225 static int
226 flags_from_portable(int pflags)
227 {
228 int flags = 0;
229
230 if ((pflags & SSH2_FXF_READ) &&
231 (pflags & SSH2_FXF_WRITE)) {
232 flags = O_RDWR;
233 } else if (pflags & SSH2_FXF_READ) {
234 flags = O_RDONLY;
235 } else if (pflags & SSH2_FXF_WRITE) {
236 flags = O_WRONLY;
237 }
238 if (pflags & SSH2_FXF_APPEND)
239 flags |= O_APPEND;
240 if (pflags & SSH2_FXF_CREAT)
241 flags |= O_CREAT;
242 if (pflags & SSH2_FXF_TRUNC)
243 flags |= O_TRUNC;
244 if (pflags & SSH2_FXF_EXCL)
245 flags |= O_EXCL;
246 return flags;
247 }
248
249 static const char *
250 string_from_portable(int pflags)
251 {
252 static char ret[128];
253
254 *ret = '\0';
255
256 #define PAPPEND(str) { \
257 if (*ret != '\0') \
258 strlcat(ret, ",", sizeof(ret)); \
259 strlcat(ret, str, sizeof(ret)); \
260 }
261
262 if (pflags & SSH2_FXF_READ)
263 PAPPEND("READ")
264 if (pflags & SSH2_FXF_WRITE)
265 PAPPEND("WRITE")
266 if (pflags & SSH2_FXF_APPEND)
267 PAPPEND("APPEND")
268 if (pflags & SSH2_FXF_CREAT)
269 PAPPEND("CREATE")
270 if (pflags & SSH2_FXF_TRUNC)
271 PAPPEND("TRUNCATE")
272 if (pflags & SSH2_FXF_EXCL)
273 PAPPEND("EXCL")
274
275 return ret;
276 }
277
278 static Attrib *
279 get_attrib(void)
280 {
281 return decode_attrib(&iqueue);
282 }
283
284 /* handle handles */
285
286 typedef struct Handle Handle;
287 struct Handle {
288 int use;
289 DIR *dirp;
290 int fd;
291 int flags;
292 char *name;
293 u_int64_t bytes_read, bytes_write;
294 int next_unused;
295 };
296
297 enum {
298 HANDLE_UNUSED,
299 HANDLE_DIR,
300 HANDLE_FILE
301 };
302
303 Handle *handles = NULL;
304 u_int num_handles = 0;
305 int first_unused_handle = -1;
306
307 static void handle_unused(int i)
308 {
309 handles[i].use = HANDLE_UNUSED;
310 handles[i].next_unused = first_unused_handle;
311 first_unused_handle = i;
312 }
313
314 static int
315 handle_new(int use, const char *name, int fd, int flags, DIR *dirp)
316 {
317 int i;
318
319 if (first_unused_handle == -1) {
320 if (num_handles + 1 <= num_handles)
321 return -1;
322 num_handles++;
323 handles = xrealloc(handles, num_handles, sizeof(Handle));
324 handle_unused(num_handles - 1);
325 }
326
327 i = first_unused_handle;
328 first_unused_handle = handles[i].next_unused;
329
330 handles[i].use = use;
331 handles[i].dirp = dirp;
332 handles[i].fd = fd;
333 handles[i].flags = flags;
334 handles[i].name = xstrdup(name);
335 handles[i].bytes_read = handles[i].bytes_write = 0;
336
337 return i;
338 }
339
340 static int
341 handle_is_ok(int i, int type)
342 {
343 return i >= 0 && (u_int)i < num_handles && handles[i].use == type;
344 }
345
346 static int
347 handle_to_string(int handle, char **stringp, int *hlenp)
348 {
349 if (stringp == NULL || hlenp == NULL)
350 return -1;
351 *stringp = xmalloc(sizeof(int32_t));
352 put_u32(*stringp, handle);
353 *hlenp = sizeof(int32_t);
354 return 0;
355 }
356
357 static int
358 handle_from_string(const char *handle, u_int hlen)
359 {
360 int val;
361
362 if (hlen != sizeof(int32_t))
363 return -1;
364 val = get_u32(handle);
365 if (handle_is_ok(val, HANDLE_FILE) ||
366 handle_is_ok(val, HANDLE_DIR))
367 return val;
368 return -1;
369 }
370
371 static char *
372 handle_to_name(int handle)
373 {
374 if (handle_is_ok(handle, HANDLE_DIR)||
375 handle_is_ok(handle, HANDLE_FILE))
376 return handles[handle].name;
377 return NULL;
378 }
379
380 static DIR *
381 handle_to_dir(int handle)
382 {
383 if (handle_is_ok(handle, HANDLE_DIR))
384 return handles[handle].dirp;
385 return NULL;
386 }
387
388 static int
389 handle_to_fd(int handle)
390 {
391 if (handle_is_ok(handle, HANDLE_FILE))
392 return handles[handle].fd;
393 return -1;
394 }
395
396 static int
397 handle_to_flags(int handle)
398 {
399 if (handle_is_ok(handle, HANDLE_FILE))
400 return handles[handle].flags;
401 return 0;
402 }
403
404 static void
405 handle_update_read(int handle, ssize_t bytes)
406 {
407 if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
408 handles[handle].bytes_read += bytes;
409 }
410
411 static void
412 handle_update_write(int handle, ssize_t bytes)
413 {
414 if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
415 handles[handle].bytes_write += bytes;
416 }
417
418 static u_int64_t
419 handle_bytes_read(int handle)
420 {
421 if (handle_is_ok(handle, HANDLE_FILE))
422 return (handles[handle].bytes_read);
423 return 0;
424 }
425
426 static u_int64_t
427 handle_bytes_write(int handle)
428 {
429 if (handle_is_ok(handle, HANDLE_FILE))
430 return (handles[handle].bytes_write);
431 return 0;
432 }
433
434 static int
435 handle_close(int handle)
436 {
437 int ret = -1;
438
439 if (handle_is_ok(handle, HANDLE_FILE)) {
440 ret = close(handles[handle].fd);
441 free(handles[handle].name);
442 handle_unused(handle);
443 } else if (handle_is_ok(handle, HANDLE_DIR)) {
444 ret = closedir(handles[handle].dirp);
445 free(handles[handle].name);
446 handle_unused(handle);
447 } else {
448 errno = ENOENT;
449 }
450 return ret;
451 }
452
453 static void
454 handle_log_close(int handle, char *emsg)
455 {
456 if (handle_is_ok(handle, HANDLE_FILE)) {
457 logit("%s%sclose \"%s\" bytes read %llu written %llu",
458 emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
459 handle_to_name(handle),
460 (unsigned long long)handle_bytes_read(handle),
461 (unsigned long long)handle_bytes_write(handle));
462 } else {
463 logit("%s%sclosedir \"%s\"",
464 emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
465 handle_to_name(handle));
466 }
467 }
468
469 static void
470 handle_log_exit(void)
471 {
472 u_int i;
473
474 for (i = 0; i < num_handles; i++)
475 if (handles[i].use != HANDLE_UNUSED)
476 handle_log_close(i, "forced");
477 }
478
479 static int
480 get_handle(void)
481 {
482 char *handle;
483 int val = -1;
484 u_int hlen;
485
486 handle = get_string(&hlen);
487 if (hlen < 256)
488 val = handle_from_string(handle, hlen);
489 free(handle);
490 return val;
491 }
492
493 /* send replies */
494
495 static void
496 send_msg(Buffer *m)
497 {
498 int mlen = buffer_len(m);
499
500 buffer_put_int(&oqueue, mlen);
501 buffer_append(&oqueue, buffer_ptr(m), mlen);
502 buffer_consume(m, mlen);
503 }
504
505 static const char *
506 status_to_message(u_int32_t status)
507 {
508 const char *status_messages[] = {
509 "Success", /* SSH_FX_OK */
510 "End of file", /* SSH_FX_EOF */
511 "No such file", /* SSH_FX_NO_SUCH_FILE */
512 "Permission denied", /* SSH_FX_PERMISSION_DENIED */
513 "Failure", /* SSH_FX_FAILURE */
514 "Bad message", /* SSH_FX_BAD_MESSAGE */
515 "No connection", /* SSH_FX_NO_CONNECTION */
516 "Connection lost", /* SSH_FX_CONNECTION_LOST */
517 "Operation unsupported", /* SSH_FX_OP_UNSUPPORTED */
518 "Unknown error" /* Others */
519 };
520 return (status_messages[MIN(status,SSH2_FX_MAX)]);
521 }
522
523 static void
524 send_status(u_int32_t id, u_int32_t status)
525 {
526 Buffer msg;
527
528 debug3("request %u: sent status %u", id, status);
529 if (log_level > SYSLOG_LEVEL_VERBOSE ||
530 (status != SSH2_FX_OK && status != SSH2_FX_EOF))
531 logit("sent status %s", status_to_message(status));
532 buffer_init(&msg);
533 buffer_put_char(&msg, SSH2_FXP_STATUS);
534 buffer_put_int(&msg, id);
535 buffer_put_int(&msg, status);
536 if (version >= 3) {
537 buffer_put_cstring(&msg, status_to_message(status));
538 buffer_put_cstring(&msg, "");
539 }
540 send_msg(&msg);
541 buffer_free(&msg);
542 }
543 static void
544 send_data_or_handle(char type, u_int32_t id, const char *data, int dlen)
545 {
546 Buffer msg;
547
548 buffer_init(&msg);
549 buffer_put_char(&msg, type);
550 buffer_put_int(&msg, id);
551 buffer_put_string(&msg, data, dlen);
552 send_msg(&msg);
553 buffer_free(&msg);
554 }
555
556 static void
557 send_data(u_int32_t id, const char *data, int dlen)
558 {
559 debug("request %u: sent data len %d", id, dlen);
560 send_data_or_handle(SSH2_FXP_DATA, id, data, dlen);
561 }
562
563 static void
564 send_handle(u_int32_t id, int handle)
565 {
566 char *string;
567 int hlen;
568
569 handle_to_string(handle, &string, &hlen);
570 debug("request %u: sent handle handle %d", id, handle);
571 send_data_or_handle(SSH2_FXP_HANDLE, id, string, hlen);
572 free(string);
573 }
574
575 static void
576 send_names(u_int32_t id, int count, const Stat *stats)
577 {
578 Buffer msg;
579 int i;
580
581 buffer_init(&msg);
582 buffer_put_char(&msg, SSH2_FXP_NAME);
583 buffer_put_int(&msg, id);
584 buffer_put_int(&msg, count);
585 debug("request %u: sent names count %d", id, count);
586 for (i = 0; i < count; i++) {
587 buffer_put_cstring(&msg, stats[i].name);
588 buffer_put_cstring(&msg, stats[i].long_name);
589 encode_attrib(&msg, &stats[i].attrib);
590 }
591 send_msg(&msg);
592 buffer_free(&msg);
593 }
594
595 static void
596 send_attrib(u_int32_t id, const Attrib *a)
597 {
598 Buffer msg;
599
600 debug("request %u: sent attrib have 0x%x", id, a->flags);
601 buffer_init(&msg);
602 buffer_put_char(&msg, SSH2_FXP_ATTRS);
603 buffer_put_int(&msg, id);
604 encode_attrib(&msg, a);
605 send_msg(&msg);
606 buffer_free(&msg);
607 }
608
609 static void
610 send_statvfs(u_int32_t id, struct statvfs *st)
611 {
612 Buffer msg;
613 u_int64_t flag;
614
615 flag = (st->f_flag & ST_RDONLY) ? SSH2_FXE_STATVFS_ST_RDONLY : 0;
616 flag |= (st->f_flag & ST_NOSUID) ? SSH2_FXE_STATVFS_ST_NOSUID : 0;
617
618 buffer_init(&msg);
619 buffer_put_char(&msg, SSH2_FXP_EXTENDED_REPLY);
620 buffer_put_int(&msg, id);
621 buffer_put_int64(&msg, st->f_bsize);
622 buffer_put_int64(&msg, st->f_frsize);
623 buffer_put_int64(&msg, st->f_blocks);
624 buffer_put_int64(&msg, st->f_bfree);
625 buffer_put_int64(&msg, st->f_bavail);
626 buffer_put_int64(&msg, st->f_files);
627 buffer_put_int64(&msg, st->f_ffree);
628 buffer_put_int64(&msg, st->f_favail);
629 buffer_put_int64(&msg, FSID_TO_ULONG(st->f_fsid));
630 buffer_put_int64(&msg, flag);
631 buffer_put_int64(&msg, st->f_namemax);
632 send_msg(&msg);
633 buffer_free(&msg);
634 }
635
636 /* parse incoming */
637
638 static void
639 process_init(void)
640 {
641 Buffer msg;
642
643 version = get_int();
644 verbose("received client version %u", version);
645 buffer_init(&msg);
646 buffer_put_char(&msg, SSH2_FXP_VERSION);
647 buffer_put_int(&msg, SSH2_FILEXFER_VERSION);
648 /* POSIX rename extension */
649 buffer_put_cstring(&msg, "posix-rename@openssh.com");
650 buffer_put_cstring(&msg, "1"); /* version */
651 /* statvfs extension */
652 buffer_put_cstring(&msg, "statvfs@openssh.com");
653 buffer_put_cstring(&msg, "2"); /* version */
654 /* fstatvfs extension */
655 buffer_put_cstring(&msg, "fstatvfs@openssh.com");
656 buffer_put_cstring(&msg, "2"); /* version */
657 /* hardlink extension */
658 buffer_put_cstring(&msg, "hardlink@openssh.com");
659 buffer_put_cstring(&msg, "1"); /* version */
660 /* fsync extension */
661 buffer_put_cstring(&msg, "fsync@openssh.com");
662 buffer_put_cstring(&msg, "1"); /* version */
663 send_msg(&msg);
664 buffer_free(&msg);
665 }
666
667 static void
668 process_open(u_int32_t id)
669 {
670 u_int32_t pflags;
671 Attrib *a;
672 char *name;
673 int handle, fd, flags, mode, status = SSH2_FX_FAILURE;
674
675 name = get_string(NULL);
676 pflags = get_int(); /* portable flags */
677 debug3("request %u: open flags %d", id, pflags);
678 a = get_attrib();
679 flags = flags_from_portable(pflags);
680 mode = (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? a->perm : 0666;
681 logit("open \"%s\" flags %s mode 0%o",
682 name, string_from_portable(pflags), mode);
683 if (readonly &&
684 ((flags & O_ACCMODE) == O_WRONLY ||
685 (flags & O_ACCMODE) == O_RDWR)) {
686 verbose("Refusing open request in read-only mode");
687 status = SSH2_FX_PERMISSION_DENIED;
688 } else {
689 fd = open(name, flags, mode);
690 if (fd < 0) {
691 status = errno_to_portable(errno);
692 } else {
693 handle = handle_new(HANDLE_FILE, name, fd, flags, NULL);
694 if (handle < 0) {
695 close(fd);
696 } else {
697 send_handle(id, handle);
698 status = SSH2_FX_OK;
699 }
700 }
701 }
702 if (status != SSH2_FX_OK)
703 send_status(id, status);
704 free(name);
705 }
706
707 static void
708 process_close(u_int32_t id)
709 {
710 int handle, ret, status = SSH2_FX_FAILURE;
711
712 handle = get_handle();
713 debug3("request %u: close handle %u", id, handle);
714 handle_log_close(handle, NULL);
715 ret = handle_close(handle);
716 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
717 send_status(id, status);
718 }
719
720 static void
721 process_read(u_int32_t id)
722 {
723 char buf[64*1024];
724 u_int32_t len;
725 int handle, fd, ret, status = SSH2_FX_FAILURE;
726 u_int64_t off;
727
728 handle = get_handle();
729 off = get_int64();
730 len = get_int();
731
732 debug("request %u: read \"%s\" (handle %d) off %llu len %d",
733 id, handle_to_name(handle), handle, (unsigned long long)off, len);
734 if (len > sizeof buf) {
735 len = sizeof buf;
736 debug2("read change len %d", len);
737 }
738 fd = handle_to_fd(handle);
739 if (fd >= 0) {
740 if (lseek(fd, off, SEEK_SET) < 0) {
741 error("process_read: seek failed");
742 status = errno_to_portable(errno);
743 } else {
744 ret = read(fd, buf, len);
745 if (ret < 0) {
746 status = errno_to_portable(errno);
747 } else if (ret == 0) {
748 status = SSH2_FX_EOF;
749 } else {
750 send_data(id, buf, ret);
751 status = SSH2_FX_OK;
752 handle_update_read(handle, ret);
753 }
754 }
755 }
756 if (status != SSH2_FX_OK)
757 send_status(id, status);
758 }
759
760 static void
761 process_write(u_int32_t id)
762 {
763 u_int64_t off;
764 u_int len;
765 int handle, fd, ret, status;
766 char *data;
767
768 handle = get_handle();
769 off = get_int64();
770 data = get_string(&len);
771
772 debug("request %u: write \"%s\" (handle %d) off %llu len %d",
773 id, handle_to_name(handle), handle, (unsigned long long)off, len);
774 fd = handle_to_fd(handle);
775
776 if (fd < 0)
777 status = SSH2_FX_FAILURE;
778 else {
779 if (!(handle_to_flags(handle) & O_APPEND) &&
780 lseek(fd, off, SEEK_SET) < 0) {
781 status = errno_to_portable(errno);
782 error("process_write: seek failed");
783 } else {
784 /* XXX ATOMICIO ? */
785 ret = write(fd, data, len);
786 if (ret < 0) {
787 error("process_write: write failed");
788 status = errno_to_portable(errno);
789 } else if ((size_t)ret == len) {
790 status = SSH2_FX_OK;
791 handle_update_write(handle, ret);
792 } else {
793 debug2("nothing at all written");
794 status = SSH2_FX_FAILURE;
795 }
796 }
797 }
798 send_status(id, status);
799 free(data);
800 }
801
802 static void
803 process_do_stat(u_int32_t id, int do_lstat)
804 {
805 Attrib a;
806 struct stat st;
807 char *name;
808 int ret, status = SSH2_FX_FAILURE;
809
810 name = get_string(NULL);
811 debug3("request %u: %sstat", id, do_lstat ? "l" : "");
812 verbose("%sstat name \"%s\"", do_lstat ? "l" : "", name);
813 ret = do_lstat ? lstat(name, &st) : stat(name, &st);
814 if (ret < 0) {
815 status = errno_to_portable(errno);
816 } else {
817 stat_to_attrib(&st, &a);
818 send_attrib(id, &a);
819 status = SSH2_FX_OK;
820 }
821 if (status != SSH2_FX_OK)
822 send_status(id, status);
823 free(name);
824 }
825
826 static void
827 process_stat(u_int32_t id)
828 {
829 process_do_stat(id, 0);
830 }
831
832 static void
833 process_lstat(u_int32_t id)
834 {
835 process_do_stat(id, 1);
836 }
837
838 static void
839 process_fstat(u_int32_t id)
840 {
841 Attrib a;
842 struct stat st;
843 int fd, ret, handle, status = SSH2_FX_FAILURE;
844
845 handle = get_handle();
846 debug("request %u: fstat \"%s\" (handle %u)",
847 id, handle_to_name(handle), handle);
848 fd = handle_to_fd(handle);
849 if (fd >= 0) {
850 ret = fstat(fd, &st);
851 if (ret < 0) {
852 status = errno_to_portable(errno);
853 } else {
854 stat_to_attrib(&st, &a);
855 send_attrib(id, &a);
856 status = SSH2_FX_OK;
857 }
858 }
859 if (status != SSH2_FX_OK)
860 send_status(id, status);
861 }
862
863 static struct timeval *
864 attrib_to_tv(const Attrib *a)
865 {
866 static struct timeval tv[2];
867
868 tv[0].tv_sec = a->atime;
869 tv[0].tv_usec = 0;
870 tv[1].tv_sec = a->mtime;
871 tv[1].tv_usec = 0;
872 return tv;
873 }
874
875 static void
876 process_setstat(u_int32_t id)
877 {
878 Attrib *a;
879 char *name;
880 int status = SSH2_FX_OK, ret;
881
882 name = get_string(NULL);
883 a = get_attrib();
884 debug("request %u: setstat name \"%s\"", id, name);
885 if (a->flags & SSH2_FILEXFER_ATTR_SIZE) {
886 logit("set \"%s\" size %llu",
887 name, (unsigned long long)a->size);
888 ret = truncate(name, a->size);
889 if (ret == -1)
890 status = errno_to_portable(errno);
891 }
892 if (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
893 logit("set \"%s\" mode %04o", name, a->perm);
894 ret = chmod(name, a->perm & 07777);
895 if (ret == -1)
896 status = errno_to_portable(errno);
897 }
898 if (a->flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
899 char buf[64];
900 time_t t = a->mtime;
901
902 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
903 localtime(&t));
904 logit("set \"%s\" modtime %s", name, buf);
905 ret = utimes(name, attrib_to_tv(a));
906 if (ret == -1)
907 status = errno_to_portable(errno);
908 }
909 if (a->flags & SSH2_FILEXFER_ATTR_UIDGID) {
910 logit("set \"%s\" owner %lu group %lu", name,
911 (u_long)a->uid, (u_long)a->gid);
912 ret = chown(name, a->uid, a->gid);
913 if (ret == -1)
914 status = errno_to_portable(errno);
915 }
916 send_status(id, status);
917 free(name);
918 }
919
920 static void
921 process_fsetstat(u_int32_t id)
922 {
923 Attrib *a;
924 int handle, fd, ret;
925 int status = SSH2_FX_OK;
926
927 handle = get_handle();
928 a = get_attrib();
929 debug("request %u: fsetstat handle %d", id, handle);
930 fd = handle_to_fd(handle);
931 if (fd < 0)
932 status = SSH2_FX_FAILURE;
933 else {
934 char *name = handle_to_name(handle);
935
936 if (a->flags & SSH2_FILEXFER_ATTR_SIZE) {
937 logit("set \"%s\" size %llu",
938 name, (unsigned long long)a->size);
939 ret = ftruncate(fd, a->size);
940 if (ret == -1)
941 status = errno_to_portable(errno);
942 }
943 if (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
944 logit("set \"%s\" mode %04o", name, a->perm);
945 #ifdef HAVE_FCHMOD
946 ret = fchmod(fd, a->perm & 07777);
947 #else
948 ret = chmod(name, a->perm & 07777);
949 #endif
950 if (ret == -1)
951 status = errno_to_portable(errno);
952 }
953 if (a->flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
954 char buf[64];
955 time_t t = a->mtime;
956
957 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
958 localtime(&t));
959 logit("set \"%s\" modtime %s", name, buf);
960 #ifdef HAVE_FUTIMES
961 ret = futimes(fd, attrib_to_tv(a));
962 #else
963 ret = utimes(name, attrib_to_tv(a));
964 #endif
965 if (ret == -1)
966 status = errno_to_portable(errno);
967 }
968 if (a->flags & SSH2_FILEXFER_ATTR_UIDGID) {
969 logit("set \"%s\" owner %lu group %lu", name,
970 (u_long)a->uid, (u_long)a->gid);
971 #ifdef HAVE_FCHOWN
972 ret = fchown(fd, a->uid, a->gid);
973 #else
974 ret = chown(name, a->uid, a->gid);
975 #endif
976 if (ret == -1)
977 status = errno_to_portable(errno);
978 }
979 }
980 send_status(id, status);
981 }
982
983 static void
984 process_opendir(u_int32_t id)
985 {
986 DIR *dirp = NULL;
987 char *path;
988 int handle, status = SSH2_FX_FAILURE;
989
990 path = get_string(NULL);
991 debug3("request %u: opendir", id);
992 logit("opendir \"%s\"", path);
993 dirp = opendir(path);
994 if (dirp == NULL) {
995 status = errno_to_portable(errno);
996 } else {
997 handle = handle_new(HANDLE_DIR, path, 0, 0, dirp);
998 if (handle < 0) {
999 closedir(dirp);
1000 } else {
1001 send_handle(id, handle);
1002 status = SSH2_FX_OK;
1003 }
1004
1005 }
1006 if (status != SSH2_FX_OK)
1007 send_status(id, status);
1008 free(path);
1009 }
1010
1011 static void
1012 process_readdir(u_int32_t id)
1013 {
1014 DIR *dirp;
1015 struct dirent *dp;
1016 char *path;
1017 int handle;
1018
1019 handle = get_handle();
1020 debug("request %u: readdir \"%s\" (handle %d)", id,
1021 handle_to_name(handle), handle);
1022 dirp = handle_to_dir(handle);
1023 path = handle_to_name(handle);
1024 if (dirp == NULL || path == NULL) {
1025 send_status(id, SSH2_FX_FAILURE);
1026 } else {
1027 struct stat st;
1028 char pathname[MAXPATHLEN];
1029 Stat *stats;
1030 int nstats = 10, count = 0, i;
1031
1032 stats = xcalloc(nstats, sizeof(Stat));
1033 while ((dp = readdir(dirp)) != NULL) {
1034 if (count >= nstats) {
1035 nstats *= 2;
1036 stats = xrealloc(stats, nstats, sizeof(Stat));
1037 }
1038 /* XXX OVERFLOW ? */
1039 snprintf(pathname, sizeof pathname, "%s%s%s", path,
1040 strcmp(path, "/") ? "/" : "", dp->d_name);
1041 if (lstat(pathname, &st) < 0)
1042 continue;
1043 stat_to_attrib(&st, &(stats[count].attrib));
1044 stats[count].name = xstrdup(dp->d_name);
1045 stats[count].long_name = ls_file(dp->d_name, &st, 0, 0);
1046 count++;
1047 /* send up to 100 entries in one message */
1048 /* XXX check packet size instead */
1049 if (count == 100)
1050 break;
1051 }
1052 if (count > 0) {
1053 send_names(id, count, stats);
1054 for (i = 0; i < count; i++) {
1055 free(stats[i].name);
1056 free(stats[i].long_name);
1057 }
1058 } else {
1059 send_status(id, SSH2_FX_EOF);
1060 }
1061 free(stats);
1062 }
1063 }
1064
1065 static void
1066 process_remove(u_int32_t id)
1067 {
1068 char *name;
1069 int status = SSH2_FX_FAILURE;
1070 int ret;
1071
1072 name = get_string(NULL);
1073 debug3("request %u: remove", id);
1074 logit("remove name \"%s\"", name);
1075 ret = unlink(name);
1076 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1077 send_status(id, status);
1078 free(name);
1079 }
1080
1081 static void
1082 process_mkdir(u_int32_t id)
1083 {
1084 Attrib *a;
1085 char *name;
1086 int ret, mode, status = SSH2_FX_FAILURE;
1087
1088 name = get_string(NULL);
1089 a = get_attrib();
1090 mode = (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ?
1091 a->perm & 07777 : 0777;
1092 debug3("request %u: mkdir", id);
1093 logit("mkdir name \"%s\" mode 0%o", name, mode);
1094 ret = mkdir(name, mode);
1095 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1096 send_status(id, status);
1097 free(name);
1098 }
1099
1100 static void
1101 process_rmdir(u_int32_t id)
1102 {
1103 char *name;
1104 int ret, status;
1105
1106 name = get_string(NULL);
1107 debug3("request %u: rmdir", id);
1108 logit("rmdir name \"%s\"", name);
1109 ret = rmdir(name);
1110 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1111 send_status(id, status);
1112 free(name);
1113 }
1114
1115 static void
1116 process_realpath(u_int32_t id)
1117 {
1118 char resolvedname[MAXPATHLEN];
1119 char *path;
1120
1121 path = get_string(NULL);
1122 if (path[0] == '\0') {
1123 free(path);
1124 path = xstrdup(".");
1125 }
1126 debug3("request %u: realpath", id);
1127 verbose("realpath \"%s\"", path);
1128 if (realpath(path, resolvedname) == NULL) {
1129 send_status(id, errno_to_portable(errno));
1130 } else {
1131 Stat s;
1132 attrib_clear(&s.attrib);
1133 s.name = s.long_name = resolvedname;
1134 send_names(id, 1, &s);
1135 }
1136 free(path);
1137 }
1138
1139 static void
1140 process_rename(u_int32_t id)
1141 {
1142 char *oldpath, *newpath;
1143 int status;
1144 struct stat sb;
1145
1146 oldpath = get_string(NULL);
1147 newpath = get_string(NULL);
1148 debug3("request %u: rename", id);
1149 logit("rename old \"%s\" new \"%s\"", oldpath, newpath);
1150 status = SSH2_FX_FAILURE;
1151 if (lstat(oldpath, &sb) == -1)
1152 status = errno_to_portable(errno);
1153 else if (S_ISREG(sb.st_mode)) {
1154 /* Race-free rename of regular files */
1155 if (link(oldpath, newpath) == -1) {
1156 if (errno == EOPNOTSUPP || errno == ENOSYS
1157 #ifdef EXDEV
1158 || errno == EXDEV
1159 #endif
1160 #ifdef LINK_OPNOTSUPP_ERRNO
1161 || errno == LINK_OPNOTSUPP_ERRNO
1162 #endif
1163 ) {
1164 struct stat st;
1165
1166 /*
1167 * fs doesn't support links, so fall back to
1168 * stat+rename. This is racy.
1169 */
1170 if (stat(newpath, &st) == -1) {
1171 if (rename(oldpath, newpath) == -1)
1172 status =
1173 errno_to_portable(errno);
1174 else
1175 status = SSH2_FX_OK;
1176 }
1177 } else {
1178 status = errno_to_portable(errno);
1179 }
1180 } else if (unlink(oldpath) == -1) {
1181 status = errno_to_portable(errno);
1182 /* clean spare link */
1183 unlink(newpath);
1184 } else
1185 status = SSH2_FX_OK;
1186 } else if (stat(newpath, &sb) == -1) {
1187 if (rename(oldpath, newpath) == -1)
1188 status = errno_to_portable(errno);
1189 else
1190 status = SSH2_FX_OK;
1191 }
1192 send_status(id, status);
1193 free(oldpath);
1194 free(newpath);
1195 }
1196
1197 static void
1198 process_readlink(u_int32_t id)
1199 {
1200 int len;
1201 char buf[MAXPATHLEN];
1202 char *path;
1203
1204 path = get_string(NULL);
1205 debug3("request %u: readlink", id);
1206 verbose("readlink \"%s\"", path);
1207 if ((len = readlink(path, buf, sizeof(buf) - 1)) == -1)
1208 send_status(id, errno_to_portable(errno));
1209 else {
1210 Stat s;
1211
1212 buf[len] = '\0';
1213 attrib_clear(&s.attrib);
1214 s.name = s.long_name = buf;
1215 send_names(id, 1, &s);
1216 }
1217 free(path);
1218 }
1219
1220 static void
1221 process_symlink(u_int32_t id)
1222 {
1223 char *oldpath, *newpath;
1224 int ret, status;
1225
1226 oldpath = get_string(NULL);
1227 newpath = get_string(NULL);
1228 debug3("request %u: symlink", id);
1229 logit("symlink old \"%s\" new \"%s\"", oldpath, newpath);
1230 /* this will fail if 'newpath' exists */
1231 ret = symlink(oldpath, newpath);
1232 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1233 send_status(id, status);
1234 free(oldpath);
1235 free(newpath);
1236 }
1237
1238 static void
1239 process_extended_posix_rename(u_int32_t id)
1240 {
1241 char *oldpath, *newpath;
1242 int ret, status;
1243
1244 oldpath = get_string(NULL);
1245 newpath = get_string(NULL);
1246 debug3("request %u: posix-rename", id);
1247 logit("posix-rename old \"%s\" new \"%s\"", oldpath, newpath);
1248 ret = rename(oldpath, newpath);
1249 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1250 send_status(id, status);
1251 free(oldpath);
1252 free(newpath);
1253 }
1254
1255 static void
1256 process_extended_statvfs(u_int32_t id)
1257 {
1258 char *path;
1259 struct statvfs st;
1260
1261 path = get_string(NULL);
1262 debug3("request %u: statvfs", id);
1263 logit("statvfs \"%s\"", path);
1264
1265 if (statvfs(path, &st) != 0)
1266 send_status(id, errno_to_portable(errno));
1267 else
1268 send_statvfs(id, &st);
1269 free(path);
1270 }
1271
1272 static void
1273 process_extended_fstatvfs(u_int32_t id)
1274 {
1275 int handle, fd;
1276 struct statvfs st;
1277
1278 handle = get_handle();
1279 debug("request %u: fstatvfs \"%s\" (handle %u)",
1280 id, handle_to_name(handle), handle);
1281 if ((fd = handle_to_fd(handle)) < 0) {
1282 send_status(id, SSH2_FX_FAILURE);
1283 return;
1284 }
1285 if (fstatvfs(fd, &st) != 0)
1286 send_status(id, errno_to_portable(errno));
1287 else
1288 send_statvfs(id, &st);
1289 }
1290
1291 static void
1292 process_extended_hardlink(u_int32_t id)
1293 {
1294 char *oldpath, *newpath;
1295 int ret, status;
1296
1297 oldpath = get_string(NULL);
1298 newpath = get_string(NULL);
1299 debug3("request %u: hardlink", id);
1300 logit("hardlink old \"%s\" new \"%s\"", oldpath, newpath);
1301 ret = link(oldpath, newpath);
1302 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1303 send_status(id, status);
1304 free(oldpath);
1305 free(newpath);
1306 }
1307
1308 static void
1309 process_extended_fsync(u_int32_t id)
1310 {
1311 int handle, fd, ret, status = SSH2_FX_OP_UNSUPPORTED;
1312
1313 handle = get_handle();
1314 debug3("request %u: fsync (handle %u)", id, handle);
1315 verbose("fsync \"%s\"", handle_to_name(handle));
1316 if ((fd = handle_to_fd(handle)) < 0)
1317 status = SSH2_FX_NO_SUCH_FILE;
1318 else if (handle_is_ok(handle, HANDLE_FILE)) {
1319 ret = fsync(fd);
1320 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1321 }
1322 send_status(id, status);
1323 }
1324
1325 static void
1326 process_extended(u_int32_t id)
1327 {
1328 char *request;
1329 u_int i;
1330
1331 request = get_string(NULL);
1332 for (i = 0; extended_handlers[i].handler != NULL; i++) {
1333 if (strcmp(request, extended_handlers[i].ext_name) == 0) {
1334 if (!request_permitted(&extended_handlers[i]))
1335 send_status(id, SSH2_FX_PERMISSION_DENIED);
1336 else
1337 extended_handlers[i].handler(id);
1338 break;
1339 }
1340 }
1341 if (extended_handlers[i].handler == NULL) {
1342 error("Unknown extended request \"%.100s\"", request);
1343 send_status(id, SSH2_FX_OP_UNSUPPORTED); /* MUST */
1344 }
1345 free(request);
1346 }
1347
1348 /* stolen from ssh-agent */
1349
1350 static void
1351 process(void)
1352 {
1353 u_int msg_len, buf_len, consumed, type, i;
1354 u_char *cp;
1355 u_int32_t id;
1356
1357 buf_len = buffer_len(&iqueue);
1358 if (buf_len < 5)
1359 return; /* Incomplete message. */
1360 cp = buffer_ptr(&iqueue);
1361 msg_len = get_u32(cp);
1362 if (msg_len > SFTP_MAX_MSG_LENGTH) {
1363 error("bad message from %s local user %s",
1364 client_addr, pw->pw_name);
1365 sftp_server_cleanup_exit(11);
1366 }
1367 if (buf_len < msg_len + 4)
1368 return;
1369 buffer_consume(&iqueue, 4);
1370 buf_len -= 4;
1371 type = buffer_get_char(&iqueue);
1372
1373 switch (type) {
1374 case SSH2_FXP_INIT:
1375 process_init();
1376 init_done = 1;
1377 break;
1378 case SSH2_FXP_EXTENDED:
1379 if (!init_done)
1380 fatal("Received extended request before init");
1381 id = get_int();
1382 process_extended(id);
1383 break;
1384 default:
1385 if (!init_done)
1386 fatal("Received %u request before init", type);
1387 id = get_int();
1388 for (i = 0; handlers[i].handler != NULL; i++) {
1389 if (type == handlers[i].type) {
1390 if (!request_permitted(&handlers[i])) {
1391 send_status(id,
1392 SSH2_FX_PERMISSION_DENIED);
1393 } else {
1394 handlers[i].handler(id);
1395 }
1396 break;
1397 }
1398 }
1399 if (handlers[i].handler == NULL)
1400 error("Unknown message %u", type);
1401 }
1402 /* discard the remaining bytes from the current packet */
1403 if (buf_len < buffer_len(&iqueue)) {
1404 error("iqueue grew unexpectedly");
1405 sftp_server_cleanup_exit(255);
1406 }
1407 consumed = buf_len - buffer_len(&iqueue);
1408 if (msg_len < consumed) {
1409 error("msg_len %u < consumed %u", msg_len, consumed);
1410 sftp_server_cleanup_exit(255);
1411 }
1412 if (msg_len > consumed)
1413 buffer_consume(&iqueue, msg_len - consumed);
1414 }
1415
1416 /* Cleanup handler that logs active handles upon normal exit */
1417 void
1418 sftp_server_cleanup_exit(int i)
1419 {
1420 if (pw != NULL && client_addr != NULL) {
1421 handle_log_exit();
1422 logit("session closed for local user %s from [%s]",
1423 pw->pw_name, client_addr);
1424 }
1425 _exit(i);
1426 }
1427
1428 static void
1429 sftp_server_usage(void)
1430 {
1431 extern char *__progname;
1432
1433 fprintf(stderr,
1434 "usage: %s [-ehR] [-d start_directory] [-f log_facility] "
1435 "[-l log_level]\n\t[-P blacklisted_requests] "
1436 "[-p whitelisted_requests] [-u umask]\n"
1437 " %s -Q protocol_feature\n",
1438 __progname, __progname);
1439 exit(1);
1440 }
1441
1442 int
1443 sftp_server_main(int argc, char **argv, struct passwd *user_pw)
1444 {
1445 fd_set *rset, *wset;
1446 int i, in, out, max, ch, skipargs = 0, log_stderr = 0;
1447 ssize_t len, olen, set_size;
1448 SyslogFacility log_facility = SYSLOG_FACILITY_AUTH;
1449 char *cp, *homedir = NULL, buf[4*4096];
1450 long mask;
1451
1452 extern char *optarg;
1453 extern char *__progname;
1454
1455 __progname = ssh_get_progname(argv[0]);
1456 log_init(__progname, log_level, log_facility, log_stderr);
1457
1458 pw = pwcopy(user_pw);
1459
1460 while (!skipargs && (ch = getopt(argc, argv,
1461 "d:f:l:P:p:Q:u:cehR")) != -1) {
1462 switch (ch) {
1463 case 'Q':
1464 if (strcasecmp(optarg, "requests") != 0) {
1465 fprintf(stderr, "Invalid query type\n");
1466 exit(1);
1467 }
1468 for (i = 0; handlers[i].handler != NULL; i++)
1469 printf("%s\n", handlers[i].name);
1470 for (i = 0; extended_handlers[i].handler != NULL; i++)
1471 printf("%s\n", extended_handlers[i].name);
1472 exit(0);
1473 break;
1474 case 'R':
1475 readonly = 1;
1476 break;
1477 case 'c':
1478 /*
1479 * Ignore all arguments if we are invoked as a
1480 * shell using "sftp-server -c command"
1481 */
1482 skipargs = 1;
1483 break;
1484 case 'e':
1485 log_stderr = 1;
1486 break;
1487 case 'l':
1488 log_level = log_level_number(optarg);
1489 if (log_level == SYSLOG_LEVEL_NOT_SET)
1490 error("Invalid log level \"%s\"", optarg);
1491 break;
1492 case 'f':
1493 log_facility = log_facility_number(optarg);
1494 if (log_facility == SYSLOG_FACILITY_NOT_SET)
1495 error("Invalid log facility \"%s\"", optarg);
1496 break;
1497 case 'd':
1498 cp = tilde_expand_filename(optarg, user_pw->pw_uid);
1499 homedir = percent_expand(cp, "d", user_pw->pw_dir,
1500 "u", user_pw->pw_name, (char *)NULL);
1501 free(cp);
1502 break;
1503 case 'p':
1504 if (request_whitelist != NULL)
1505 fatal("Permitted requests already set");
1506 request_whitelist = xstrdup(optarg);
1507 break;
1508 case 'P':
1509 if (request_blacklist != NULL)
1510 fatal("Refused requests already set");
1511 request_blacklist = xstrdup(optarg);
1512 break;
1513 case 'u':
1514 errno = 0;
1515 mask = strtol(optarg, &cp, 8);
1516 if (mask < 0 || mask > 0777 || *cp != '\0' ||
1517 cp == optarg || (mask == 0 && errno != 0))
1518 fatal("Invalid umask \"%s\"", optarg);
1519 (void)umask((mode_t)mask);
1520 break;
1521 case 'h':
1522 default:
1523 sftp_server_usage();
1524 }
1525 }
1526
1527 log_init(__progname, log_level, log_facility, log_stderr);
1528
1529 #if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
1530 /*
1531 * On Linux, we should try to avoid making /proc/self/{mem,maps}
1532 * available to the user so that sftp access doesn't automatically
1533 * imply arbitrary code execution access that will break
1534 * restricted configurations.
1535 */
1536 if (prctl(PR_SET_DUMPABLE, 0) != 0)
1537 fatal("unable to make the process undumpable");
1538 #endif /* defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE) */
1539
1540 if ((cp = getenv("SSH_CONNECTION")) != NULL) {
1541 client_addr = xstrdup(cp);
1542 if ((cp = strchr(client_addr, ' ')) == NULL) {
1543 error("Malformed SSH_CONNECTION variable: \"%s\"",
1544 getenv("SSH_CONNECTION"));
1545 sftp_server_cleanup_exit(255);
1546 }
1547 *cp = '\0';
1548 } else
1549 client_addr = xstrdup("UNKNOWN");
1550
1551 logit("session opened for local user %s from [%s]",
1552 pw->pw_name, client_addr);
1553
1554 in = STDIN_FILENO;
1555 out = STDOUT_FILENO;
1556
1557 #ifdef HAVE_CYGWIN
1558 setmode(in, O_BINARY);
1559 setmode(out, O_BINARY);
1560 #endif
1561
1562 max = 0;
1563 if (in > max)
1564 max = in;
1565 if (out > max)
1566 max = out;
1567
1568 buffer_init(&iqueue);
1569 buffer_init(&oqueue);
1570
1571 set_size = howmany(max + 1, NFDBITS) * sizeof(fd_mask);
1572 rset = (fd_set *)xmalloc(set_size);
1573 wset = (fd_set *)xmalloc(set_size);
1574
1575 if (homedir != NULL) {
1576 if (chdir(homedir) != 0) {
1577 error("chdir to \"%s\" failed: %s", homedir,
1578 strerror(errno));
1579 }
1580 }
1581
1582 for (;;) {
1583 memset(rset, 0, set_size);
1584 memset(wset, 0, set_size);
1585
1586 /*
1587 * Ensure that we can read a full buffer and handle
1588 * the worst-case length packet it can generate,
1589 * otherwise apply backpressure by stopping reads.
1590 */
1591 if (buffer_check_alloc(&iqueue, sizeof(buf)) &&
1592 buffer_check_alloc(&oqueue, SFTP_MAX_MSG_LENGTH))
1593 FD_SET(in, rset);
1594
1595 olen = buffer_len(&oqueue);
1596 if (olen > 0)
1597 FD_SET(out, wset);
1598
1599 if (select(max+1, rset, wset, NULL, NULL) < 0) {
1600 if (errno == EINTR)
1601 continue;
1602 error("select: %s", strerror(errno));
1603 sftp_server_cleanup_exit(2);
1604 }
1605
1606 /* copy stdin to iqueue */
1607 if (FD_ISSET(in, rset)) {
1608 len = read(in, buf, sizeof buf);
1609 if (len == 0) {
1610 debug("read eof");
1611 sftp_server_cleanup_exit(0);
1612 } else if (len < 0) {
1613 error("read: %s", strerror(errno));
1614 sftp_server_cleanup_exit(1);
1615 } else {
1616 buffer_append(&iqueue, buf, len);
1617 }
1618 }
1619 /* send oqueue to stdout */
1620 if (FD_ISSET(out, wset)) {
1621 len = write(out, buffer_ptr(&oqueue), olen);
1622 if (len < 0) {
1623 error("write: %s", strerror(errno));
1624 sftp_server_cleanup_exit(1);
1625 } else {
1626 buffer_consume(&oqueue, len);
1627 }
1628 }
1629
1630 /*
1631 * Process requests from client if we can fit the results
1632 * into the output buffer, otherwise stop processing input
1633 * and let the output queue drain.
1634 */
1635 if (buffer_check_alloc(&oqueue, SFTP_MAX_MSG_LENGTH))
1636 process();
1637 }
1638 }
DragonFly BSD