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
33 #include <dirent.h>
34 #include <errno.h>
35 #include <fcntl.h>
36 #include <pwd.h>
37 #include <stdlib.h>
38 #include <stdio.h>
39 #include <string.h>
40 #include <pwd.h>
41 #include <time.h>
42 #include <unistd.h>
43 #include <stdarg.h>
44
45 #include "xmalloc.h"
46 #include "buffer.h"
47 #include "log.h"
48 #include "misc.h"
49 #include "match.h"
50 #include "uidswap.h"
51
52 #include "sftp.h"
53 #include "sftp-common.h"
54
55 /* helper */
56 #define get_int64() buffer_get_int64(&iqueue);
57 #define get_int() buffer_get_int(&iqueue);
58 #define get_string(lenp) buffer_get_string(&iqueue, lenp);
59
60 /* Our verbosity */
61 static LogLevel log_level = SYSLOG_LEVEL_ERROR;
62
63 /* Our client */
64 static struct passwd *pw = NULL;
65 static char *client_addr = NULL;
66
67 /* input and output queue */
68 static Buffer iqueue;
69 static Buffer oqueue;
70
71 /* Version of client */
72 static u_int version;
73
74 /* SSH2_FXP_INIT received */
75 static int init_done;
76
77 /* Disable writes */
78 static int readonly;
79
80 /* Requests that are allowed/denied */
81 static char *request_whitelist, *request_blacklist;
82
83 /* portable attributes, etc. */
84 typedef struct Stat Stat;
85
86 struct Stat {
87 char *name;
88 char *long_name;
89 Attrib attrib;
90 };
91
92 /* Packet handlers */
93 static void process_open(u_int32_t id);
94 static void process_close(u_int32_t id);
95 static void process_read(u_int32_t id);
96 static void process_write(u_int32_t id);
97 static void process_stat(u_int32_t id);
98 static void process_lstat(u_int32_t id);
99 static void process_fstat(u_int32_t id);
100 static void process_setstat(u_int32_t id);
101 static void process_fsetstat(u_int32_t id);
102 static void process_opendir(u_int32_t id);
103 static void process_readdir(u_int32_t id);
104 static void process_remove(u_int32_t id);
105 static void process_mkdir(u_int32_t id);
106 static void process_rmdir(u_int32_t id);
107 static void process_realpath(u_int32_t id);
108 static void process_rename(u_int32_t id);
109 static void process_readlink(u_int32_t id);
110 static void process_symlink(u_int32_t id);
111 static void process_extended_posix_rename(u_int32_t id);
112 static void process_extended_statvfs(u_int32_t id);
113 static void process_extended_fstatvfs(u_int32_t id);
114 static void process_extended_hardlink(u_int32_t id);
115 static void process_extended_fsync(u_int32_t id);
116 static void process_extended(u_int32_t id);
117
118 struct sftp_handler {
119 const char *name; /* user-visible name for fine-grained perms */
120 const char *ext_name; /* extended request name */
121 u_int type; /* packet type, for non extended packets */
122 void (*handler)(u_int32_t);
123 int does_write; /* if nonzero, banned for readonly mode */
124 };
125
126 struct sftp_handler handlers[] = {
127 /* NB. SSH2_FXP_OPEN does the readonly check in the handler itself */
128 { "open", NULL, SSH2_FXP_OPEN, process_open, 0 },
129 { "close", NULL, SSH2_FXP_CLOSE, process_close, 0 },
130 { "read", NULL, SSH2_FXP_READ, process_read, 0 },
131 { "write", NULL, SSH2_FXP_WRITE, process_write, 1 },
132 { "lstat", NULL, SSH2_FXP_LSTAT, process_lstat, 0 },
133 { "fstat", NULL, SSH2_FXP_FSTAT, process_fstat, 0 },
134 { "setstat", NULL, SSH2_FXP_SETSTAT, process_setstat, 1 },
135 { "fsetstat", NULL, SSH2_FXP_FSETSTAT, process_fsetstat, 1 },
136 { "opendir", NULL, SSH2_FXP_OPENDIR, process_opendir, 0 },
137 { "readdir", NULL, SSH2_FXP_READDIR, process_readdir, 0 },
138 { "remove", NULL, SSH2_FXP_REMOVE, process_remove, 1 },
139 { "mkdir", NULL, SSH2_FXP_MKDIR, process_mkdir, 1 },
140 { "rmdir", NULL, SSH2_FXP_RMDIR, process_rmdir, 1 },
141 { "realpath", NULL, SSH2_FXP_REALPATH, process_realpath, 0 },
142 { "stat", NULL, SSH2_FXP_STAT, process_stat, 0 },
143 { "rename", NULL, SSH2_FXP_RENAME, process_rename, 1 },
144 { "readlink", NULL, SSH2_FXP_READLINK, process_readlink, 0 },
145 { "symlink", NULL, SSH2_FXP_SYMLINK, process_symlink, 1 },
146 { NULL, NULL, 0, NULL, 0 }
147 };
148
149 /* SSH2_FXP_EXTENDED submessages */
150 struct sftp_handler extended_handlers[] = {
151 { "posix-rename", "posix-rename@openssh.com", 0,
152 process_extended_posix_rename, 1 },
153 { "statvfs", "statvfs@openssh.com", 0, process_extended_statvfs, 0 },
154 { "fstatvfs", "fstatvfs@openssh.com", 0, process_extended_fstatvfs, 0 },
155 { "hardlink", "hardlink@openssh.com", 0, process_extended_hardlink, 1 },
156 { "fsync", "fsync@openssh.com", 0, process_extended_fsync, 1 },
157 { NULL, NULL, 0, NULL, 0 }
158 };
159
160 static int
request_permitted(struct sftp_handler * h)161 request_permitted(struct sftp_handler *h)
162 {
163 char *result;
164
165 if (readonly && h->does_write) {
166 verbose("Refusing %s request in read-only mode", h->name);
167 return 0;
168 }
169 if (request_blacklist != NULL &&
170 ((result = match_list(h->name, request_blacklist, NULL))) != NULL) {
171 free(result);
172 verbose("Refusing blacklisted %s request", h->name);
173 return 0;
174 }
175 if (request_whitelist != NULL &&
176 ((result = match_list(h->name, request_whitelist, NULL))) != NULL) {
177 free(result);
178 debug2("Permitting whitelisted %s request", h->name);
179 return 1;
180 }
181 if (request_whitelist != NULL) {
182 verbose("Refusing non-whitelisted %s request", h->name);
183 return 0;
184 }
185 return 1;
186 }
187
188 static int
errno_to_portable(int unixerrno)189 errno_to_portable(int unixerrno)
190 {
191 int ret = 0;
192
193 switch (unixerrno) {
194 case 0:
195 ret = SSH2_FX_OK;
196 break;
197 case ENOENT:
198 case ENOTDIR:
199 case EBADF:
200 case ELOOP:
201 ret = SSH2_FX_NO_SUCH_FILE;
202 break;
203 case EPERM:
204 case EACCES:
205 case EFAULT:
206 ret = SSH2_FX_PERMISSION_DENIED;
207 break;
208 case ENAMETOOLONG:
209 case EINVAL:
210 ret = SSH2_FX_BAD_MESSAGE;
211 break;
212 case ENOSYS:
213 ret = SSH2_FX_OP_UNSUPPORTED;
214 break;
215 default:
216 ret = SSH2_FX_FAILURE;
217 break;
218 }
219 return ret;
220 }
221
222 static int
flags_from_portable(int pflags)223 flags_from_portable(int pflags)
224 {
225 int flags = 0;
226
227 if ((pflags & SSH2_FXF_READ) &&
228 (pflags & SSH2_FXF_WRITE)) {
229 flags = O_RDWR;
230 } else if (pflags & SSH2_FXF_READ) {
231 flags = O_RDONLY;
232 } else if (pflags & SSH2_FXF_WRITE) {
233 flags = O_WRONLY;
234 }
235 if (pflags & SSH2_FXF_APPEND)
236 flags |= O_APPEND;
237 if (pflags & SSH2_FXF_CREAT)
238 flags |= O_CREAT;
239 if (pflags & SSH2_FXF_TRUNC)
240 flags |= O_TRUNC;
241 if (pflags & SSH2_FXF_EXCL)
242 flags |= O_EXCL;
243 return flags;
244 }
245
246 static const char *
string_from_portable(int pflags)247 string_from_portable(int pflags)
248 {
249 static char ret[128];
250
251 *ret = '\0';
252
253 #define PAPPEND(str) { \
254 if (*ret != '\0') \
255 strlcat(ret, ",", sizeof(ret)); \
256 strlcat(ret, str, sizeof(ret)); \
257 }
258
259 if (pflags & SSH2_FXF_READ)
260 PAPPEND("READ")
261 if (pflags & SSH2_FXF_WRITE)
262 PAPPEND("WRITE")
263 if (pflags & SSH2_FXF_APPEND)
264 PAPPEND("APPEND")
265 if (pflags & SSH2_FXF_CREAT)
266 PAPPEND("CREATE")
267 if (pflags & SSH2_FXF_TRUNC)
268 PAPPEND("TRUNCATE")
269 if (pflags & SSH2_FXF_EXCL)
270 PAPPEND("EXCL")
271
272 return ret;
273 }
274
275 static Attrib *
get_attrib(void)276 get_attrib(void)
277 {
278 return decode_attrib(&iqueue);
279 }
280
281 /* handle handles */
282
283 typedef struct Handle Handle;
284 struct Handle {
285 int use;
286 DIR *dirp;
287 int fd;
288 int flags;
289 char *name;
290 u_int64_t bytes_read, bytes_write;
291 int next_unused;
292 };
293
294 enum {
295 HANDLE_UNUSED,
296 HANDLE_DIR,
297 HANDLE_FILE
298 };
299
300 Handle *handles = NULL;
301 u_int num_handles = 0;
302 int first_unused_handle = -1;
303
handle_unused(int i)304 static void handle_unused(int i)
305 {
306 handles[i].use = HANDLE_UNUSED;
307 handles[i].next_unused = first_unused_handle;
308 first_unused_handle = i;
309 }
310
311 static int
handle_new(int use,const char * name,int fd,int flags,DIR * dirp)312 handle_new(int use, const char *name, int fd, int flags, DIR *dirp)
313 {
314 int i;
315
316 if (first_unused_handle == -1) {
317 if (num_handles + 1 <= num_handles)
318 return -1;
319 num_handles++;
320 handles = xrealloc(handles, num_handles, sizeof(Handle));
321 handle_unused(num_handles - 1);
322 }
323
324 i = first_unused_handle;
325 first_unused_handle = handles[i].next_unused;
326
327 handles[i].use = use;
328 handles[i].dirp = dirp;
329 handles[i].fd = fd;
330 handles[i].flags = flags;
331 handles[i].name = xstrdup(name);
332 handles[i].bytes_read = handles[i].bytes_write = 0;
333
334 return i;
335 }
336
337 static int
handle_is_ok(int i,int type)338 handle_is_ok(int i, int type)
339 {
340 return i >= 0 && (u_int)i < num_handles && handles[i].use == type;
341 }
342
343 static int
handle_to_string(int handle,char ** stringp,int * hlenp)344 handle_to_string(int handle, char **stringp, int *hlenp)
345 {
346 if (stringp == NULL || hlenp == NULL)
347 return -1;
348 *stringp = xmalloc(sizeof(int32_t));
349 put_u32(*stringp, handle);
350 *hlenp = sizeof(int32_t);
351 return 0;
352 }
353
354 static int
handle_from_string(const char * handle,u_int hlen)355 handle_from_string(const char *handle, u_int hlen)
356 {
357 int val;
358
359 if (hlen != sizeof(int32_t))
360 return -1;
361 val = get_u32(handle);
362 if (handle_is_ok(val, HANDLE_FILE) ||
363 handle_is_ok(val, HANDLE_DIR))
364 return val;
365 return -1;
366 }
367
368 static char *
handle_to_name(int handle)369 handle_to_name(int handle)
370 {
371 if (handle_is_ok(handle, HANDLE_DIR)||
372 handle_is_ok(handle, HANDLE_FILE))
373 return handles[handle].name;
374 return NULL;
375 }
376
377 static DIR *
handle_to_dir(int handle)378 handle_to_dir(int handle)
379 {
380 if (handle_is_ok(handle, HANDLE_DIR))
381 return handles[handle].dirp;
382 return NULL;
383 }
384
385 static int
handle_to_fd(int handle)386 handle_to_fd(int handle)
387 {
388 if (handle_is_ok(handle, HANDLE_FILE))
389 return handles[handle].fd;
390 return -1;
391 }
392
393 static int
handle_to_flags(int handle)394 handle_to_flags(int handle)
395 {
396 if (handle_is_ok(handle, HANDLE_FILE))
397 return handles[handle].flags;
398 return 0;
399 }
400
401 static void
handle_update_read(int handle,ssize_t bytes)402 handle_update_read(int handle, ssize_t bytes)
403 {
404 if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
405 handles[handle].bytes_read += bytes;
406 }
407
408 static void
handle_update_write(int handle,ssize_t bytes)409 handle_update_write(int handle, ssize_t bytes)
410 {
411 if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
412 handles[handle].bytes_write += bytes;
413 }
414
415 static u_int64_t
handle_bytes_read(int handle)416 handle_bytes_read(int handle)
417 {
418 if (handle_is_ok(handle, HANDLE_FILE))
419 return (handles[handle].bytes_read);
420 return 0;
421 }
422
423 static u_int64_t
handle_bytes_write(int handle)424 handle_bytes_write(int handle)
425 {
426 if (handle_is_ok(handle, HANDLE_FILE))
427 return (handles[handle].bytes_write);
428 return 0;
429 }
430
431 static int
handle_close(int handle)432 handle_close(int handle)
433 {
434 int ret = -1;
435
436 if (handle_is_ok(handle, HANDLE_FILE)) {
437 ret = close(handles[handle].fd);
438 free(handles[handle].name);
439 handle_unused(handle);
440 } else if (handle_is_ok(handle, HANDLE_DIR)) {
441 ret = closedir(handles[handle].dirp);
442 free(handles[handle].name);
443 handle_unused(handle);
444 } else {
445 errno = ENOENT;
446 }
447 return ret;
448 }
449
450 static void
handle_log_close(int handle,char * emsg)451 handle_log_close(int handle, char *emsg)
452 {
453 if (handle_is_ok(handle, HANDLE_FILE)) {
454 logit("%s%sclose \"%s\" bytes read %llu written %llu",
455 emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
456 handle_to_name(handle),
457 (unsigned long long)handle_bytes_read(handle),
458 (unsigned long long)handle_bytes_write(handle));
459 } else {
460 logit("%s%sclosedir \"%s\"",
461 emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
462 handle_to_name(handle));
463 }
464 }
465
466 static void
handle_log_exit(void)467 handle_log_exit(void)
468 {
469 u_int i;
470
471 for (i = 0; i < num_handles; i++)
472 if (handles[i].use != HANDLE_UNUSED)
473 handle_log_close(i, "forced");
474 }
475
476 static int
get_handle(void)477 get_handle(void)
478 {
479 char *handle;
480 int val = -1;
481 u_int hlen;
482
483 handle = get_string(&hlen);
484 if (hlen < 256)
485 val = handle_from_string(handle, hlen);
486 free(handle);
487 return val;
488 }
489
490 /* send replies */
491
492 static void
send_msg(Buffer * m)493 send_msg(Buffer *m)
494 {
495 int mlen = buffer_len(m);
496
497 buffer_put_int(&oqueue, mlen);
498 buffer_append(&oqueue, buffer_ptr(m), mlen);
499 buffer_consume(m, mlen);
500 }
501
502 static const char *
status_to_message(u_int32_t status)503 status_to_message(u_int32_t status)
504 {
505 const char *status_messages[] = {
506 "Success", /* SSH_FX_OK */
507 "End of file", /* SSH_FX_EOF */
508 "No such file", /* SSH_FX_NO_SUCH_FILE */
509 "Permission denied", /* SSH_FX_PERMISSION_DENIED */
510 "Failure", /* SSH_FX_FAILURE */
511 "Bad message", /* SSH_FX_BAD_MESSAGE */
512 "No connection", /* SSH_FX_NO_CONNECTION */
513 "Connection lost", /* SSH_FX_CONNECTION_LOST */
514 "Operation unsupported", /* SSH_FX_OP_UNSUPPORTED */
515 "Unknown error" /* Others */
516 };
517 return (status_messages[MIN(status,SSH2_FX_MAX)]);
518 }
519
520 static void
send_status(u_int32_t id,u_int32_t status)521 send_status(u_int32_t id, u_int32_t status)
522 {
523 Buffer msg;
524
525 debug3("request %u: sent status %u", id, status);
526 if (log_level > SYSLOG_LEVEL_VERBOSE ||
527 (status != SSH2_FX_OK && status != SSH2_FX_EOF))
528 logit("sent status %s", status_to_message(status));
529 buffer_init(&msg);
530 buffer_put_char(&msg, SSH2_FXP_STATUS);
531 buffer_put_int(&msg, id);
532 buffer_put_int(&msg, status);
533 if (version >= 3) {
534 buffer_put_cstring(&msg, status_to_message(status));
535 buffer_put_cstring(&msg, "");
536 }
537 send_msg(&msg);
538 buffer_free(&msg);
539 }
540 static void
send_data_or_handle(char type,u_int32_t id,const char * data,int dlen)541 send_data_or_handle(char type, u_int32_t id, const char *data, int dlen)
542 {
543 Buffer msg;
544
545 buffer_init(&msg);
546 buffer_put_char(&msg, type);
547 buffer_put_int(&msg, id);
548 buffer_put_string(&msg, data, dlen);
549 send_msg(&msg);
550 buffer_free(&msg);
551 }
552
553 static void
send_data(u_int32_t id,const char * data,int dlen)554 send_data(u_int32_t id, const char *data, int dlen)
555 {
556 debug("request %u: sent data len %d", id, dlen);
557 send_data_or_handle(SSH2_FXP_DATA, id, data, dlen);
558 }
559
560 static void
send_handle(u_int32_t id,int handle)561 send_handle(u_int32_t id, int handle)
562 {
563 char *string;
564 int hlen;
565
566 handle_to_string(handle, &string, &hlen);
567 debug("request %u: sent handle handle %d", id, handle);
568 send_data_or_handle(SSH2_FXP_HANDLE, id, string, hlen);
569 free(string);
570 }
571
572 static void
send_names(u_int32_t id,int count,const Stat * stats)573 send_names(u_int32_t id, int count, const Stat *stats)
574 {
575 Buffer msg;
576 int i;
577
578 buffer_init(&msg);
579 buffer_put_char(&msg, SSH2_FXP_NAME);
580 buffer_put_int(&msg, id);
581 buffer_put_int(&msg, count);
582 debug("request %u: sent names count %d", id, count);
583 for (i = 0; i < count; i++) {
584 buffer_put_cstring(&msg, stats[i].name);
585 buffer_put_cstring(&msg, stats[i].long_name);
586 encode_attrib(&msg, &stats[i].attrib);
587 }
588 send_msg(&msg);
589 buffer_free(&msg);
590 }
591
592 static void
send_attrib(u_int32_t id,const Attrib * a)593 send_attrib(u_int32_t id, const Attrib *a)
594 {
595 Buffer msg;
596
597 debug("request %u: sent attrib have 0x%x", id, a->flags);
598 buffer_init(&msg);
599 buffer_put_char(&msg, SSH2_FXP_ATTRS);
600 buffer_put_int(&msg, id);
601 encode_attrib(&msg, a);
602 send_msg(&msg);
603 buffer_free(&msg);
604 }
605
606 static void
send_statvfs(u_int32_t id,struct statvfs * st)607 send_statvfs(u_int32_t id, struct statvfs *st)
608 {
609 Buffer msg;
610 u_int64_t flag;
611
612 flag = (st->f_flag & ST_RDONLY) ? SSH2_FXE_STATVFS_ST_RDONLY : 0;
613 flag |= (st->f_flag & ST_NOSUID) ? SSH2_FXE_STATVFS_ST_NOSUID : 0;
614
615 buffer_init(&msg);
616 buffer_put_char(&msg, SSH2_FXP_EXTENDED_REPLY);
617 buffer_put_int(&msg, id);
618 buffer_put_int64(&msg, st->f_bsize);
619 buffer_put_int64(&msg, st->f_frsize);
620 buffer_put_int64(&msg, st->f_blocks);
621 buffer_put_int64(&msg, st->f_bfree);
622 buffer_put_int64(&msg, st->f_bavail);
623 buffer_put_int64(&msg, st->f_files);
624 buffer_put_int64(&msg, st->f_ffree);
625 buffer_put_int64(&msg, st->f_favail);
626 buffer_put_int64(&msg, FSID_TO_ULONG(st->f_fsid));
627 buffer_put_int64(&msg, flag);
628 buffer_put_int64(&msg, st->f_namemax);
629 send_msg(&msg);
630 buffer_free(&msg);
631 }
632
633 /* parse incoming */
634
635 static void
process_init(void)636 process_init(void)
637 {
638 Buffer msg;
639
640 version = get_int();
641 verbose("received client version %u", version);
642 buffer_init(&msg);
643 buffer_put_char(&msg, SSH2_FXP_VERSION);
644 buffer_put_int(&msg, SSH2_FILEXFER_VERSION);
645 /* POSIX rename extension */
646 buffer_put_cstring(&msg, "posix-rename@openssh.com");
647 buffer_put_cstring(&msg, "1"); /* version */
648 /* statvfs extension */
649 buffer_put_cstring(&msg, "statvfs@openssh.com");
650 buffer_put_cstring(&msg, "2"); /* version */
651 /* fstatvfs extension */
652 buffer_put_cstring(&msg, "fstatvfs@openssh.com");
653 buffer_put_cstring(&msg, "2"); /* version */
654 /* hardlink extension */
655 buffer_put_cstring(&msg, "hardlink@openssh.com");
656 buffer_put_cstring(&msg, "1"); /* version */
657 /* fsync extension */
658 buffer_put_cstring(&msg, "fsync@openssh.com");
659 buffer_put_cstring(&msg, "1"); /* version */
660 send_msg(&msg);
661 buffer_free(&msg);
662 }
663
664 static void
process_open(u_int32_t id)665 process_open(u_int32_t id)
666 {
667 u_int32_t pflags;
668 Attrib *a;
669 char *name;
670 int handle, fd, flags, mode, status = SSH2_FX_FAILURE;
671
672 name = get_string(NULL);
673 pflags = get_int(); /* portable flags */
674 debug3("request %u: open flags %d", id, pflags);
675 a = get_attrib();
676 flags = flags_from_portable(pflags);
677 mode = (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? a->perm : 0666;
678 logit("open \"%s\" flags %s mode 0%o",
679 name, string_from_portable(pflags), mode);
680 if (readonly &&
681 ((flags & O_ACCMODE) == O_WRONLY ||
682 (flags & O_ACCMODE) == O_RDWR)) {
683 verbose("Refusing open request in read-only mode");
684 status = SSH2_FX_PERMISSION_DENIED;
685 } else {
686 fd = open(name, flags, mode);
687 if (fd < 0) {
688 status = errno_to_portable(errno);
689 } else {
690 handle = handle_new(HANDLE_FILE, name, fd, flags, NULL);
691 if (handle < 0) {
692 close(fd);
693 } else {
694 send_handle(id, handle);
695 status = SSH2_FX_OK;
696 }
697 }
698 }
699 if (status != SSH2_FX_OK)
700 send_status(id, status);
701 free(name);
702 }
703
704 static void
process_close(u_int32_t id)705 process_close(u_int32_t id)
706 {
707 int handle, ret, status = SSH2_FX_FAILURE;
708
709 handle = get_handle();
710 debug3("request %u: close handle %u", id, handle);
711 handle_log_close(handle, NULL);
712 ret = handle_close(handle);
713 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
714 send_status(id, status);
715 }
716
717 static void
process_read(u_int32_t id)718 process_read(u_int32_t id)
719 {
720 char buf[64*1024];
721 u_int32_t len;
722 int handle, fd, ret, status = SSH2_FX_FAILURE;
723 u_int64_t off;
724
725 handle = get_handle();
726 off = get_int64();
727 len = get_int();
728
729 debug("request %u: read \"%s\" (handle %d) off %llu len %d",
730 id, handle_to_name(handle), handle, (unsigned long long)off, len);
731 if (len > sizeof buf) {
732 len = sizeof buf;
733 debug2("read change len %d", len);
734 }
735 fd = handle_to_fd(handle);
736 if (fd >= 0) {
737 if (lseek(fd, off, SEEK_SET) < 0) {
738 error("process_read: seek failed");
739 status = errno_to_portable(errno);
740 } else {
741 ret = read(fd, buf, len);
742 if (ret < 0) {
743 status = errno_to_portable(errno);
744 } else if (ret == 0) {
745 status = SSH2_FX_EOF;
746 } else {
747 send_data(id, buf, ret);
748 status = SSH2_FX_OK;
749 handle_update_read(handle, ret);
750 }
751 }
752 }
753 if (status != SSH2_FX_OK)
754 send_status(id, status);
755 }
756
757 static void
process_write(u_int32_t id)758 process_write(u_int32_t id)
759 {
760 u_int64_t off;
761 u_int len;
762 int handle, fd, ret, status;
763 char *data;
764
765 handle = get_handle();
766 off = get_int64();
767 data = get_string(&len);
768
769 debug("request %u: write \"%s\" (handle %d) off %llu len %d",
770 id, handle_to_name(handle), handle, (unsigned long long)off, len);
771 fd = handle_to_fd(handle);
772
773 if (fd < 0)
774 status = SSH2_FX_FAILURE;
775 else {
776 if (!(handle_to_flags(handle) & O_APPEND) &&
777 lseek(fd, off, SEEK_SET) < 0) {
778 status = errno_to_portable(errno);
779 error("process_write: seek failed");
780 } else {
781 /* XXX ATOMICIO ? */
782 ret = write(fd, data, len);
783 if (ret < 0) {
784 error("process_write: write failed");
785 status = errno_to_portable(errno);
786 } else if ((size_t)ret == len) {
787 status = SSH2_FX_OK;
788 handle_update_write(handle, ret);
789 } else {
790 debug2("nothing at all written");
791 status = SSH2_FX_FAILURE;
792 }
793 }
794 }
795 send_status(id, status);
796 free(data);
797 }
798
799 static void
process_do_stat(u_int32_t id,int do_lstat)800 process_do_stat(u_int32_t id, int do_lstat)
801 {
802 Attrib a;
803 struct stat st;
804 char *name;
805 int ret, status = SSH2_FX_FAILURE;
806
807 name = get_string(NULL);
808 debug3("request %u: %sstat", id, do_lstat ? "l" : "");
809 verbose("%sstat name \"%s\"", do_lstat ? "l" : "", name);
810 ret = do_lstat ? lstat(name, &st) : stat(name, &st);
811 if (ret < 0) {
812 status = errno_to_portable(errno);
813 } else {
814 stat_to_attrib(&st, &a);
815 send_attrib(id, &a);
816 status = SSH2_FX_OK;
817 }
818 if (status != SSH2_FX_OK)
819 send_status(id, status);
820 free(name);
821 }
822
823 static void
process_stat(u_int32_t id)824 process_stat(u_int32_t id)
825 {
826 process_do_stat(id, 0);
827 }
828
829 static void
process_lstat(u_int32_t id)830 process_lstat(u_int32_t id)
831 {
832 process_do_stat(id, 1);
833 }
834
835 static void
process_fstat(u_int32_t id)836 process_fstat(u_int32_t id)
837 {
838 Attrib a;
839 struct stat st;
840 int fd, ret, handle, status = SSH2_FX_FAILURE;
841
842 handle = get_handle();
843 debug("request %u: fstat \"%s\" (handle %u)",
844 id, handle_to_name(handle), handle);
845 fd = handle_to_fd(handle);
846 if (fd >= 0) {
847 ret = fstat(fd, &st);
848 if (ret < 0) {
849 status = errno_to_portable(errno);
850 } else {
851 stat_to_attrib(&st, &a);
852 send_attrib(id, &a);
853 status = SSH2_FX_OK;
854 }
855 }
856 if (status != SSH2_FX_OK)
857 send_status(id, status);
858 }
859
860 static struct timeval *
attrib_to_tv(const Attrib * a)861 attrib_to_tv(const Attrib *a)
862 {
863 static struct timeval tv[2];
864
865 tv[0].tv_sec = a->atime;
866 tv[0].tv_usec = 0;
867 tv[1].tv_sec = a->mtime;
868 tv[1].tv_usec = 0;
869 return tv;
870 }
871
872 static void
process_setstat(u_int32_t id)873 process_setstat(u_int32_t id)
874 {
875 Attrib *a;
876 char *name;
877 int status = SSH2_FX_OK, ret;
878
879 name = get_string(NULL);
880 a = get_attrib();
881 debug("request %u: setstat name \"%s\"", id, name);
882 if (a->flags & SSH2_FILEXFER_ATTR_SIZE) {
883 logit("set \"%s\" size %llu",
884 name, (unsigned long long)a->size);
885 ret = truncate(name, a->size);
886 if (ret == -1)
887 status = errno_to_portable(errno);
888 }
889 if (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
890 logit("set \"%s\" mode %04o", name, a->perm);
891 ret = chmod(name, a->perm & 07777);
892 if (ret == -1)
893 status = errno_to_portable(errno);
894 }
895 if (a->flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
896 char buf[64];
897 time_t t = a->mtime;
898
899 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
900 localtime(&t));
901 logit("set \"%s\" modtime %s", name, buf);
902 ret = utimes(name, attrib_to_tv(a));
903 if (ret == -1)
904 status = errno_to_portable(errno);
905 }
906 if (a->flags & SSH2_FILEXFER_ATTR_UIDGID) {
907 logit("set \"%s\" owner %lu group %lu", name,
908 (u_long)a->uid, (u_long)a->gid);
909 ret = chown(name, a->uid, a->gid);
910 if (ret == -1)
911 status = errno_to_portable(errno);
912 }
913 send_status(id, status);
914 free(name);
915 }
916
917 static void
process_fsetstat(u_int32_t id)918 process_fsetstat(u_int32_t id)
919 {
920 Attrib *a;
921 int handle, fd, ret;
922 int status = SSH2_FX_OK;
923
924 handle = get_handle();
925 a = get_attrib();
926 debug("request %u: fsetstat handle %d", id, handle);
927 fd = handle_to_fd(handle);
928 if (fd < 0)
929 status = SSH2_FX_FAILURE;
930 else {
931 char *name = handle_to_name(handle);
932
933 if (a->flags & SSH2_FILEXFER_ATTR_SIZE) {
934 logit("set \"%s\" size %llu",
935 name, (unsigned long long)a->size);
936 ret = ftruncate(fd, a->size);
937 if (ret == -1)
938 status = errno_to_portable(errno);
939 }
940 if (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
941 logit("set \"%s\" mode %04o", name, a->perm);
942 #ifdef HAVE_FCHMOD
943 ret = fchmod(fd, a->perm & 07777);
944 #else
945 ret = chmod(name, a->perm & 07777);
946 #endif
947 if (ret == -1)
948 status = errno_to_portable(errno);
949 }
950 if (a->flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
951 char buf[64];
952 time_t t = a->mtime;
953
954 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
955 localtime(&t));
956 logit("set \"%s\" modtime %s", name, buf);
957 #ifdef HAVE_FUTIMES
958 ret = futimes(fd, attrib_to_tv(a));
959 #else
960 ret = utimes(name, attrib_to_tv(a));
961 #endif
962 if (ret == -1)
963 status = errno_to_portable(errno);
964 }
965 if (a->flags & SSH2_FILEXFER_ATTR_UIDGID) {
966 logit("set \"%s\" owner %lu group %lu", name,
967 (u_long)a->uid, (u_long)a->gid);
968 #ifdef HAVE_FCHOWN
969 ret = fchown(fd, a->uid, a->gid);
970 #else
971 ret = chown(name, a->uid, a->gid);
972 #endif
973 if (ret == -1)
974 status = errno_to_portable(errno);
975 }
976 }
977 send_status(id, status);
978 }
979
980 static void
process_opendir(u_int32_t id)981 process_opendir(u_int32_t id)
982 {
983 DIR *dirp = NULL;
984 char *path;
985 int handle, status = SSH2_FX_FAILURE;
986
987 path = get_string(NULL);
988 debug3("request %u: opendir", id);
989 logit("opendir \"%s\"", path);
990 dirp = opendir(path);
991 if (dirp == NULL) {
992 status = errno_to_portable(errno);
993 } else {
994 handle = handle_new(HANDLE_DIR, path, 0, 0, dirp);
995 if (handle < 0) {
996 closedir(dirp);
997 } else {
998 send_handle(id, handle);
999 status = SSH2_FX_OK;
1000 }
1001
1002 }
1003 if (status != SSH2_FX_OK)
1004 send_status(id, status);
1005 free(path);
1006 }
1007
1008 static void
process_readdir(u_int32_t id)1009 process_readdir(u_int32_t id)
1010 {
1011 DIR *dirp;
1012 struct dirent *dp;
1013 char *path;
1014 int handle;
1015
1016 handle = get_handle();
1017 debug("request %u: readdir \"%s\" (handle %d)", id,
1018 handle_to_name(handle), handle);
1019 dirp = handle_to_dir(handle);
1020 path = handle_to_name(handle);
1021 if (dirp == NULL || path == NULL) {
1022 send_status(id, SSH2_FX_FAILURE);
1023 } else {
1024 struct stat st;
1025 char pathname[MAXPATHLEN];
1026 Stat *stats;
1027 int nstats = 10, count = 0, i;
1028
1029 stats = xcalloc(nstats, sizeof(Stat));
1030 while ((dp = readdir(dirp)) != NULL) {
1031 if (count >= nstats) {
1032 nstats *= 2;
1033 stats = xrealloc(stats, nstats, sizeof(Stat));
1034 }
1035 /* XXX OVERFLOW ? */
1036 snprintf(pathname, sizeof pathname, "%s%s%s", path,
1037 strcmp(path, "/") ? "/" : "", dp->d_name);
1038 if (lstat(pathname, &st) < 0)
1039 continue;
1040 stat_to_attrib(&st, &(stats[count].attrib));
1041 stats[count].name = xstrdup(dp->d_name);
1042 stats[count].long_name = ls_file(dp->d_name, &st, 0, 0);
1043 count++;
1044 /* send up to 100 entries in one message */
1045 /* XXX check packet size instead */
1046 if (count == 100)
1047 break;
1048 }
1049 if (count > 0) {
1050 send_names(id, count, stats);
1051 for (i = 0; i < count; i++) {
1052 free(stats[i].name);
1053 free(stats[i].long_name);
1054 }
1055 } else {
1056 send_status(id, SSH2_FX_EOF);
1057 }
1058 free(stats);
1059 }
1060 }
1061
1062 static void
process_remove(u_int32_t id)1063 process_remove(u_int32_t id)
1064 {
1065 char *name;
1066 int status = SSH2_FX_FAILURE;
1067 int ret;
1068
1069 name = get_string(NULL);
1070 debug3("request %u: remove", id);
1071 logit("remove name \"%s\"", name);
1072 ret = unlink(name);
1073 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1074 send_status(id, status);
1075 free(name);
1076 }
1077
1078 static void
process_mkdir(u_int32_t id)1079 process_mkdir(u_int32_t id)
1080 {
1081 Attrib *a;
1082 char *name;
1083 int ret, mode, status = SSH2_FX_FAILURE;
1084
1085 name = get_string(NULL);
1086 a = get_attrib();
1087 mode = (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ?
1088 a->perm & 07777 : 0777;
1089 debug3("request %u: mkdir", id);
1090 logit("mkdir name \"%s\" mode 0%o", name, mode);
1091 ret = mkdir(name, mode);
1092 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1093 send_status(id, status);
1094 free(name);
1095 }
1096
1097 static void
process_rmdir(u_int32_t id)1098 process_rmdir(u_int32_t id)
1099 {
1100 char *name;
1101 int ret, status;
1102
1103 name = get_string(NULL);
1104 debug3("request %u: rmdir", id);
1105 logit("rmdir name \"%s\"", name);
1106 ret = rmdir(name);
1107 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1108 send_status(id, status);
1109 free(name);
1110 }
1111
1112 static void
process_realpath(u_int32_t id)1113 process_realpath(u_int32_t id)
1114 {
1115 char resolvedname[MAXPATHLEN];
1116 char *path;
1117
1118 path = get_string(NULL);
1119 if (path[0] == '\0') {
1120 free(path);
1121 path = xstrdup(".");
1122 }
1123 debug3("request %u: realpath", id);
1124 verbose("realpath \"%s\"", path);
1125 if (realpath(path, resolvedname) == NULL) {
1126 send_status(id, errno_to_portable(errno));
1127 } else {
1128 Stat s;
1129 attrib_clear(&s.attrib);
1130 s.name = s.long_name = resolvedname;
1131 send_names(id, 1, &s);
1132 }
1133 free(path);
1134 }
1135
1136 static void
process_rename(u_int32_t id)1137 process_rename(u_int32_t id)
1138 {
1139 char *oldpath, *newpath;
1140 int status;
1141 struct stat sb;
1142
1143 oldpath = get_string(NULL);
1144 newpath = get_string(NULL);
1145 debug3("request %u: rename", id);
1146 logit("rename old \"%s\" new \"%s\"", oldpath, newpath);
1147 status = SSH2_FX_FAILURE;
1148 if (lstat(oldpath, &sb) == -1)
1149 status = errno_to_portable(errno);
1150 else if (S_ISREG(sb.st_mode)) {
1151 /* Race-free rename of regular files */
1152 if (link(oldpath, newpath) == -1) {
1153 if (errno == EOPNOTSUPP || errno == ENOSYS
1154 #ifdef EXDEV
1155 || errno == EXDEV
1156 #endif
1157 #ifdef LINK_OPNOTSUPP_ERRNO
1158 || errno == LINK_OPNOTSUPP_ERRNO
1159 #endif
1160 ) {
1161 struct stat st;
1162
1163 /*
1164 * fs doesn't support links, so fall back to
1165 * stat+rename. This is racy.
1166 */
1167 if (stat(newpath, &st) == -1) {
1168 if (rename(oldpath, newpath) == -1)
1169 status =
1170 errno_to_portable(errno);
1171 else
1172 status = SSH2_FX_OK;
1173 }
1174 } else {
1175 status = errno_to_portable(errno);
1176 }
1177 } else if (unlink(oldpath) == -1) {
1178 status = errno_to_portable(errno);
1179 /* clean spare link */
1180 unlink(newpath);
1181 } else
1182 status = SSH2_FX_OK;
1183 } else if (stat(newpath, &sb) == -1) {
1184 if (rename(oldpath, newpath) == -1)
1185 status = errno_to_portable(errno);
1186 else
1187 status = SSH2_FX_OK;
1188 }
1189 send_status(id, status);
1190 free(oldpath);
1191 free(newpath);
1192 }
1193
1194 static void
process_readlink(u_int32_t id)1195 process_readlink(u_int32_t id)
1196 {
1197 int len;
1198 char buf[MAXPATHLEN];
1199 char *path;
1200
1201 path = get_string(NULL);
1202 debug3("request %u: readlink", id);
1203 verbose("readlink \"%s\"", path);
1204 if ((len = readlink(path, buf, sizeof(buf) - 1)) == -1)
1205 send_status(id, errno_to_portable(errno));
1206 else {
1207 Stat s;
1208
1209 buf[len] = '\0';
1210 attrib_clear(&s.attrib);
1211 s.name = s.long_name = buf;
1212 send_names(id, 1, &s);
1213 }
1214 free(path);
1215 }
1216
1217 static void
process_symlink(u_int32_t id)1218 process_symlink(u_int32_t id)
1219 {
1220 char *oldpath, *newpath;
1221 int ret, status;
1222
1223 oldpath = get_string(NULL);
1224 newpath = get_string(NULL);
1225 debug3("request %u: symlink", id);
1226 logit("symlink old \"%s\" new \"%s\"", oldpath, newpath);
1227 /* this will fail if 'newpath' exists */
1228 ret = symlink(oldpath, newpath);
1229 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1230 send_status(id, status);
1231 free(oldpath);
1232 free(newpath);
1233 }
1234
1235 static void
process_extended_posix_rename(u_int32_t id)1236 process_extended_posix_rename(u_int32_t id)
1237 {
1238 char *oldpath, *newpath;
1239 int ret, status;
1240
1241 oldpath = get_string(NULL);
1242 newpath = get_string(NULL);
1243 debug3("request %u: posix-rename", id);
1244 logit("posix-rename old \"%s\" new \"%s\"", oldpath, newpath);
1245 ret = rename(oldpath, newpath);
1246 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1247 send_status(id, status);
1248 free(oldpath);
1249 free(newpath);
1250 }
1251
1252 static void
process_extended_statvfs(u_int32_t id)1253 process_extended_statvfs(u_int32_t id)
1254 {
1255 char *path;
1256 struct statvfs st;
1257
1258 path = get_string(NULL);
1259 debug3("request %u: statvfs", id);
1260 logit("statvfs \"%s\"", path);
1261
1262 if (statvfs(path, &st) != 0)
1263 send_status(id, errno_to_portable(errno));
1264 else
1265 send_statvfs(id, &st);
1266 free(path);
1267 }
1268
1269 static void
process_extended_fstatvfs(u_int32_t id)1270 process_extended_fstatvfs(u_int32_t id)
1271 {
1272 int handle, fd;
1273 struct statvfs st;
1274
1275 handle = get_handle();
1276 debug("request %u: fstatvfs \"%s\" (handle %u)",
1277 id, handle_to_name(handle), handle);
1278 if ((fd = handle_to_fd(handle)) < 0) {
1279 send_status(id, SSH2_FX_FAILURE);
1280 return;
1281 }
1282 if (fstatvfs(fd, &st) != 0)
1283 send_status(id, errno_to_portable(errno));
1284 else
1285 send_statvfs(id, &st);
1286 }
1287
1288 static void
process_extended_hardlink(u_int32_t id)1289 process_extended_hardlink(u_int32_t id)
1290 {
1291 char *oldpath, *newpath;
1292 int ret, status;
1293
1294 oldpath = get_string(NULL);
1295 newpath = get_string(NULL);
1296 debug3("request %u: hardlink", id);
1297 logit("hardlink old \"%s\" new \"%s\"", oldpath, newpath);
1298 ret = link(oldpath, newpath);
1299 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1300 send_status(id, status);
1301 free(oldpath);
1302 free(newpath);
1303 }
1304
1305 static void
process_extended_fsync(u_int32_t id)1306 process_extended_fsync(u_int32_t id)
1307 {
1308 int handle, fd, ret, status = SSH2_FX_OP_UNSUPPORTED;
1309
1310 handle = get_handle();
1311 debug3("request %u: fsync (handle %u)", id, handle);
1312 verbose("fsync \"%s\"", handle_to_name(handle));
1313 if ((fd = handle_to_fd(handle)) < 0)
1314 status = SSH2_FX_NO_SUCH_FILE;
1315 else if (handle_is_ok(handle, HANDLE_FILE)) {
1316 ret = fsync(fd);
1317 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1318 }
1319 send_status(id, status);
1320 }
1321
1322 static void
process_extended(u_int32_t id)1323 process_extended(u_int32_t id)
1324 {
1325 char *request;
1326 u_int i;
1327
1328 request = get_string(NULL);
1329 for (i = 0; extended_handlers[i].handler != NULL; i++) {
1330 if (strcmp(request, extended_handlers[i].ext_name) == 0) {
1331 if (!request_permitted(&extended_handlers[i]))
1332 send_status(id, SSH2_FX_PERMISSION_DENIED);
1333 else
1334 extended_handlers[i].handler(id);
1335 break;
1336 }
1337 }
1338 if (extended_handlers[i].handler == NULL) {
1339 error("Unknown extended request \"%.100s\"", request);
1340 send_status(id, SSH2_FX_OP_UNSUPPORTED); /* MUST */
1341 }
1342 free(request);
1343 }
1344
1345 /* stolen from ssh-agent */
1346
1347 static void
process(void)1348 process(void)
1349 {
1350 u_int msg_len, buf_len, consumed, type, i;
1351 u_char *cp;
1352 u_int32_t id;
1353
1354 buf_len = buffer_len(&iqueue);
1355 if (buf_len < 5)
1356 return; /* Incomplete message. */
1357 cp = buffer_ptr(&iqueue);
1358 msg_len = get_u32(cp);
1359 if (msg_len > SFTP_MAX_MSG_LENGTH) {
1360 error("bad message from %s local user %s",
1361 client_addr, pw->pw_name);
1362 sftp_server_cleanup_exit(11);
1363 }
1364 if (buf_len < msg_len + 4)
1365 return;
1366 buffer_consume(&iqueue, 4);
1367 buf_len -= 4;
1368 type = buffer_get_char(&iqueue);
1369
1370 switch (type) {
1371 case SSH2_FXP_INIT:
1372 process_init();
1373 init_done = 1;
1374 break;
1375 case SSH2_FXP_EXTENDED:
1376 if (!init_done)
1377 fatal("Received extended request before init");
1378 id = get_int();
1379 process_extended(id);
1380 break;
1381 default:
1382 if (!init_done)
1383 fatal("Received %u request before init", type);
1384 id = get_int();
1385 for (i = 0; handlers[i].handler != NULL; i++) {
1386 if (type == handlers[i].type) {
1387 if (!request_permitted(&handlers[i])) {
1388 send_status(id,
1389 SSH2_FX_PERMISSION_DENIED);
1390 } else {
1391 handlers[i].handler(id);
1392 }
1393 break;
1394 }
1395 }
1396 if (handlers[i].handler == NULL)
1397 error("Unknown message %u", type);
1398 }
1399 /* discard the remaining bytes from the current packet */
1400 if (buf_len < buffer_len(&iqueue)) {
1401 error("iqueue grew unexpectedly");
1402 sftp_server_cleanup_exit(255);
1403 }
1404 consumed = buf_len - buffer_len(&iqueue);
1405 if (msg_len < consumed) {
1406 error("msg_len %u < consumed %u", msg_len, consumed);
1407 sftp_server_cleanup_exit(255);
1408 }
1409 if (msg_len > consumed)
1410 buffer_consume(&iqueue, msg_len - consumed);
1411 }
1412
1413 /* Cleanup handler that logs active handles upon normal exit */
1414 void
sftp_server_cleanup_exit(int i)1415 sftp_server_cleanup_exit(int i)
1416 {
1417 if (pw != NULL && client_addr != NULL) {
1418 handle_log_exit();
1419 logit("session closed for local user %s from [%s]",
1420 pw->pw_name, client_addr);
1421 }
1422 _exit(i);
1423 }
1424
1425 static void
sftp_server_usage(void)1426 sftp_server_usage(void)
1427 {
1428 extern char *__progname;
1429
1430 fprintf(stderr,
1431 "usage: %s [-ehR] [-d start_directory] [-f log_facility] "
1432 "[-l log_level]\n\t[-P blacklisted_requests] "
1433 "[-p whitelisted_requests] [-u umask]\n"
1434 " %s -Q protocol_feature\n",
1435 __progname, __progname);
1436 exit(1);
1437 }
1438
1439 int
sftp_server_main(int argc,char ** argv,struct passwd * user_pw)1440 sftp_server_main(int argc, char **argv, struct passwd *user_pw)
1441 {
1442 fd_set *rset, *wset;
1443 int i, in, out, max, ch, skipargs = 0, log_stderr = 0;
1444 ssize_t len, olen, set_size;
1445 SyslogFacility log_facility = SYSLOG_FACILITY_AUTH;
1446 char *cp, *homedir = NULL, buf[4*4096];
1447 long mask;
1448
1449 extern char *optarg;
1450 extern char *__progname;
1451
1452 __progname = ssh_get_progname(argv[0]);
1453 log_init(__progname, log_level, log_facility, log_stderr);
1454
1455 pw = pwcopy(user_pw);
1456
1457 while (!skipargs && (ch = getopt(argc, argv,
1458 "d:f:l:P:p:Q:u:cehR")) != -1) {
1459 switch (ch) {
1460 case 'Q':
1461 if (strcasecmp(optarg, "requests") != 0) {
1462 fprintf(stderr, "Invalid query type\n");
1463 exit(1);
1464 }
1465 for (i = 0; handlers[i].handler != NULL; i++)
1466 printf("%s\n", handlers[i].name);
1467 for (i = 0; extended_handlers[i].handler != NULL; i++)
1468 printf("%s\n", extended_handlers[i].name);
1469 exit(0);
1470 break;
1471 case 'R':
1472 readonly = 1;
1473 break;
1474 case 'c':
1475 /*
1476 * Ignore all arguments if we are invoked as a
1477 * shell using "sftp-server -c command"
1478 */
1479 skipargs = 1;
1480 break;
1481 case 'e':
1482 log_stderr = 1;
1483 break;
1484 case 'l':
1485 log_level = log_level_number(optarg);
1486 if (log_level == SYSLOG_LEVEL_NOT_SET)
1487 error("Invalid log level \"%s\"", optarg);
1488 break;
1489 case 'f':
1490 log_facility = log_facility_number(optarg);
1491 if (log_facility == SYSLOG_FACILITY_NOT_SET)
1492 error("Invalid log facility \"%s\"", optarg);
1493 break;
1494 case 'd':
1495 cp = tilde_expand_filename(optarg, user_pw->pw_uid);
1496 homedir = percent_expand(cp, "d", user_pw->pw_dir,
1497 "u", user_pw->pw_name, (char *)NULL);
1498 free(cp);
1499 break;
1500 case 'p':
1501 if (request_whitelist != NULL)
1502 fatal("Permitted requests already set");
1503 request_whitelist = xstrdup(optarg);
1504 break;
1505 case 'P':
1506 if (request_blacklist != NULL)
1507 fatal("Refused requests already set");
1508 request_blacklist = xstrdup(optarg);
1509 break;
1510 case 'u':
1511 errno = 0;
1512 mask = strtol(optarg, &cp, 8);
1513 if (mask < 0 || mask > 0777 || *cp != '\0' ||
1514 cp == optarg || (mask == 0 && errno != 0))
1515 fatal("Invalid umask \"%s\"", optarg);
1516 (void)umask((mode_t)mask);
1517 break;
1518 case 'h':
1519 default:
1520 sftp_server_usage();
1521 }
1522 }
1523
1524 log_init(__progname, log_level, log_facility, log_stderr);
1525
1526 if ((cp = getenv("SSH_CONNECTION")) != NULL) {
1527 client_addr = xstrdup(cp);
1528 if ((cp = strchr(client_addr, ' ')) == NULL) {
1529 error("Malformed SSH_CONNECTION variable: \"%s\"",
1530 getenv("SSH_CONNECTION"));
1531 sftp_server_cleanup_exit(255);
1532 }
1533 *cp = '\0';
1534 } else
1535 client_addr = xstrdup("UNKNOWN");
1536
1537 logit("session opened for local user %s from [%s]",
1538 pw->pw_name, client_addr);
1539
1540 in = STDIN_FILENO;
1541 out = STDOUT_FILENO;
1542
1543 #ifdef HAVE_CYGWIN
1544 setmode(in, O_BINARY);
1545 setmode(out, O_BINARY);
1546 #endif
1547
1548 max = 0;
1549 if (in > max)
1550 max = in;
1551 if (out > max)
1552 max = out;
1553
1554 buffer_init(&iqueue);
1555 buffer_init(&oqueue);
1556
1557 set_size = howmany(max + 1, NFDBITS) * sizeof(fd_mask);
1558 rset = (fd_set *)xmalloc(set_size);
1559 wset = (fd_set *)xmalloc(set_size);
1560
1561 if (homedir != NULL) {
1562 if (chdir(homedir) != 0) {
1563 error("chdir to \"%s\" failed: %s", homedir,
1564 strerror(errno));
1565 }
1566 }
1567
1568 for (;;) {
1569 memset(rset, 0, set_size);
1570 memset(wset, 0, set_size);
1571
1572 /*
1573 * Ensure that we can read a full buffer and handle
1574 * the worst-case length packet it can generate,
1575 * otherwise apply backpressure by stopping reads.
1576 */
1577 if (buffer_check_alloc(&iqueue, sizeof(buf)) &&
1578 buffer_check_alloc(&oqueue, SFTP_MAX_MSG_LENGTH))
1579 FD_SET(in, rset);
1580
1581 olen = buffer_len(&oqueue);
1582 if (olen > 0)
1583 FD_SET(out, wset);
1584
1585 if (select(max+1, rset, wset, NULL, NULL) < 0) {
1586 if (errno == EINTR)
1587 continue;
1588 error("select: %s", strerror(errno));
1589 sftp_server_cleanup_exit(2);
1590 }
1591
1592 /* copy stdin to iqueue */
1593 if (FD_ISSET(in, rset)) {
1594 len = read(in, buf, sizeof buf);
1595 if (len == 0) {
1596 debug("read eof");
1597 sftp_server_cleanup_exit(0);
1598 } else if (len < 0) {
1599 error("read: %s", strerror(errno));
1600 sftp_server_cleanup_exit(1);
1601 } else {
1602 buffer_append(&iqueue, buf, len);
1603 }
1604 }
1605 /* send oqueue to stdout */
1606 if (FD_ISSET(out, wset)) {
1607 len = write(out, buffer_ptr(&oqueue), olen);
1608 if (len < 0) {
1609 error("write: %s", strerror(errno));
1610 sftp_server_cleanup_exit(1);
1611 } else {
1612 buffer_consume(&oqueue, len);
1613 }
1614 }
1615
1616 /*
1617 * Process requests from client if we can fit the results
1618 * into the output buffer, otherwise stop processing input
1619 * and let the output queue drain.
1620 */
1621 if (buffer_check_alloc(&oqueue, SFTP_MAX_MSG_LENGTH))
1622 process();
1623 }
1624 }
1625