1 /* $OpenBSD: sftp-server.c,v 1.148 2024/04/30 06:23:51 djm Exp $ */
2 /*
3 * Copyright (c) 2000-2004 Markus Friedl. All rights reserved.
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 #include <sys/types.h>
19 #include <sys/resource.h>
20 #include <sys/stat.h>
21 #include <sys/time.h>
22 #include <sys/mount.h>
23 #include <sys/statvfs.h>
24
25 #include <dirent.h>
26 #include <errno.h>
27 #include <fcntl.h>
28 #include <poll.h>
29 #include <stdlib.h>
30 #include <stdio.h>
31 #include <string.h>
32 #include <pwd.h>
33 #include <grp.h>
34 #include <time.h>
35 #include <unistd.h>
36 #include <stdarg.h>
37
38 #include "atomicio.h"
39 #include "xmalloc.h"
40 #include "sshbuf.h"
41 #include "ssherr.h"
42 #include "log.h"
43 #include "misc.h"
44 #include "match.h"
45 #include "uidswap.h"
46
47 #include "sftp.h"
48 #include "sftp-common.h"
49
50 char *sftp_realpath(const char *, char *); /* sftp-realpath.c */
51
52 /* Maximum data read that we are willing to accept */
53 #define SFTP_MAX_READ_LENGTH (SFTP_MAX_MSG_LENGTH - 1024)
54
55 /* Our verbosity */
56 static LogLevel log_level = SYSLOG_LEVEL_ERROR;
57
58 /* Our client */
59 static struct passwd *pw = NULL;
60 static char *client_addr = NULL;
61
62 /* input and output queue */
63 struct sshbuf *iqueue;
64 struct sshbuf *oqueue;
65
66 /* Version of client */
67 static u_int version;
68
69 /* SSH2_FXP_INIT received */
70 static int init_done;
71
72 /* Disable writes */
73 static int readonly;
74
75 /* Requests that are allowed/denied */
76 static char *request_allowlist, *request_denylist;
77
78 /* portable attributes, etc. */
79 typedef struct Stat Stat;
80
81 struct Stat {
82 char *name;
83 char *long_name;
84 Attrib attrib;
85 };
86
87 /* Packet handlers */
88 static void process_open(u_int32_t id);
89 static void process_close(u_int32_t id);
90 static void process_read(u_int32_t id);
91 static void process_write(u_int32_t id);
92 static void process_stat(u_int32_t id);
93 static void process_lstat(u_int32_t id);
94 static void process_fstat(u_int32_t id);
95 static void process_setstat(u_int32_t id);
96 static void process_fsetstat(u_int32_t id);
97 static void process_opendir(u_int32_t id);
98 static void process_readdir(u_int32_t id);
99 static void process_remove(u_int32_t id);
100 static void process_mkdir(u_int32_t id);
101 static void process_rmdir(u_int32_t id);
102 static void process_realpath(u_int32_t id);
103 static void process_rename(u_int32_t id);
104 static void process_readlink(u_int32_t id);
105 static void process_symlink(u_int32_t id);
106 static void process_extended_posix_rename(u_int32_t id);
107 static void process_extended_statvfs(u_int32_t id);
108 static void process_extended_fstatvfs(u_int32_t id);
109 static void process_extended_hardlink(u_int32_t id);
110 static void process_extended_fsync(u_int32_t id);
111 static void process_extended_lsetstat(u_int32_t id);
112 static void process_extended_limits(u_int32_t id);
113 static void process_extended_expand(u_int32_t id);
114 static void process_extended_copy_data(u_int32_t id);
115 static void process_extended_home_directory(u_int32_t id);
116 static void process_extended_get_users_groups_by_id(u_int32_t id);
117 static void process_extended(u_int32_t id);
118
119 struct sftp_handler {
120 const char *name; /* user-visible name for fine-grained perms */
121 const char *ext_name; /* extended request name */
122 u_int type; /* packet type, for non extended packets */
123 void (*handler)(u_int32_t);
124 int does_write; /* if nonzero, banned for readonly mode */
125 };
126
127 static const struct sftp_handler handlers[] = {
128 /* NB. SSH2_FXP_OPEN does the readonly check in the handler itself */
129 { "open", NULL, SSH2_FXP_OPEN, process_open, 0 },
130 { "close", NULL, SSH2_FXP_CLOSE, process_close, 0 },
131 { "read", NULL, SSH2_FXP_READ, process_read, 0 },
132 { "write", NULL, SSH2_FXP_WRITE, process_write, 1 },
133 { "lstat", NULL, SSH2_FXP_LSTAT, process_lstat, 0 },
134 { "fstat", NULL, SSH2_FXP_FSTAT, process_fstat, 0 },
135 { "setstat", NULL, SSH2_FXP_SETSTAT, process_setstat, 1 },
136 { "fsetstat", NULL, SSH2_FXP_FSETSTAT, process_fsetstat, 1 },
137 { "opendir", NULL, SSH2_FXP_OPENDIR, process_opendir, 0 },
138 { "readdir", NULL, SSH2_FXP_READDIR, process_readdir, 0 },
139 { "remove", NULL, SSH2_FXP_REMOVE, process_remove, 1 },
140 { "mkdir", NULL, SSH2_FXP_MKDIR, process_mkdir, 1 },
141 { "rmdir", NULL, SSH2_FXP_RMDIR, process_rmdir, 1 },
142 { "realpath", NULL, SSH2_FXP_REALPATH, process_realpath, 0 },
143 { "stat", NULL, SSH2_FXP_STAT, process_stat, 0 },
144 { "rename", NULL, SSH2_FXP_RENAME, process_rename, 1 },
145 { "readlink", NULL, SSH2_FXP_READLINK, process_readlink, 0 },
146 { "symlink", NULL, SSH2_FXP_SYMLINK, process_symlink, 1 },
147 { NULL, NULL, 0, NULL, 0 }
148 };
149
150 /* SSH2_FXP_EXTENDED submessages */
151 static const struct sftp_handler extended_handlers[] = {
152 { "posix-rename", "posix-rename@openssh.com", 0,
153 process_extended_posix_rename, 1 },
154 { "statvfs", "statvfs@openssh.com", 0, process_extended_statvfs, 0 },
155 { "fstatvfs", "fstatvfs@openssh.com", 0, process_extended_fstatvfs, 0 },
156 { "hardlink", "hardlink@openssh.com", 0, process_extended_hardlink, 1 },
157 { "fsync", "fsync@openssh.com", 0, process_extended_fsync, 1 },
158 { "lsetstat", "lsetstat@openssh.com", 0, process_extended_lsetstat, 1 },
159 { "limits", "limits@openssh.com", 0, process_extended_limits, 0 },
160 { "expand-path", "expand-path@openssh.com", 0,
161 process_extended_expand, 0 },
162 { "copy-data", "copy-data", 0, process_extended_copy_data, 1 },
163 { "home-directory", "home-directory", 0,
164 process_extended_home_directory, 0 },
165 { "users-groups-by-id", "users-groups-by-id@openssh.com", 0,
166 process_extended_get_users_groups_by_id, 0 },
167 { NULL, NULL, 0, NULL, 0 }
168 };
169
170 static const struct sftp_handler *
extended_handler_byname(const char * name)171 extended_handler_byname(const char *name)
172 {
173 int i;
174
175 for (i = 0; extended_handlers[i].handler != NULL; i++) {
176 if (strcmp(name, extended_handlers[i].ext_name) == 0)
177 return &extended_handlers[i];
178 }
179 return NULL;
180 }
181
182 static int
request_permitted(const struct sftp_handler * h)183 request_permitted(const struct sftp_handler *h)
184 {
185 char *result;
186
187 if (readonly && h->does_write) {
188 verbose("Refusing %s request in read-only mode", h->name);
189 return 0;
190 }
191 if (request_denylist != NULL &&
192 ((result = match_list(h->name, request_denylist, NULL))) != NULL) {
193 free(result);
194 verbose("Refusing denylisted %s request", h->name);
195 return 0;
196 }
197 if (request_allowlist != NULL &&
198 ((result = match_list(h->name, request_allowlist, NULL))) != NULL) {
199 free(result);
200 debug2("Permitting allowlisted %s request", h->name);
201 return 1;
202 }
203 if (request_allowlist != NULL) {
204 verbose("Refusing non-allowlisted %s request", h->name);
205 return 0;
206 }
207 return 1;
208 }
209
210 static int
errno_to_portable(int unixerrno)211 errno_to_portable(int unixerrno)
212 {
213 int ret = 0;
214
215 switch (unixerrno) {
216 case 0:
217 ret = SSH2_FX_OK;
218 break;
219 case ENOENT:
220 case ENOTDIR:
221 case EBADF:
222 case ELOOP:
223 ret = SSH2_FX_NO_SUCH_FILE;
224 break;
225 case EPERM:
226 case EACCES:
227 case EFAULT:
228 ret = SSH2_FX_PERMISSION_DENIED;
229 break;
230 case ENAMETOOLONG:
231 case EINVAL:
232 ret = SSH2_FX_BAD_MESSAGE;
233 break;
234 case ENOSYS:
235 ret = SSH2_FX_OP_UNSUPPORTED;
236 break;
237 default:
238 ret = SSH2_FX_FAILURE;
239 break;
240 }
241 return ret;
242 }
243
244 static int
flags_from_portable(int pflags)245 flags_from_portable(int pflags)
246 {
247 int flags = 0;
248
249 if ((pflags & SSH2_FXF_READ) &&
250 (pflags & SSH2_FXF_WRITE)) {
251 flags = O_RDWR;
252 } else if (pflags & SSH2_FXF_READ) {
253 flags = O_RDONLY;
254 } else if (pflags & SSH2_FXF_WRITE) {
255 flags = O_WRONLY;
256 }
257 if (pflags & SSH2_FXF_APPEND)
258 flags |= O_APPEND;
259 if (pflags & SSH2_FXF_CREAT)
260 flags |= O_CREAT;
261 if (pflags & SSH2_FXF_TRUNC)
262 flags |= O_TRUNC;
263 if (pflags & SSH2_FXF_EXCL)
264 flags |= O_EXCL;
265 return flags;
266 }
267
268 static const char *
string_from_portable(int pflags)269 string_from_portable(int pflags)
270 {
271 static char ret[128];
272
273 *ret = '\0';
274
275 #define PAPPEND(str) { \
276 if (*ret != '\0') \
277 strlcat(ret, ",", sizeof(ret)); \
278 strlcat(ret, str, sizeof(ret)); \
279 }
280
281 if (pflags & SSH2_FXF_READ)
282 PAPPEND("READ")
283 if (pflags & SSH2_FXF_WRITE)
284 PAPPEND("WRITE")
285 if (pflags & SSH2_FXF_APPEND)
286 PAPPEND("APPEND")
287 if (pflags & SSH2_FXF_CREAT)
288 PAPPEND("CREATE")
289 if (pflags & SSH2_FXF_TRUNC)
290 PAPPEND("TRUNCATE")
291 if (pflags & SSH2_FXF_EXCL)
292 PAPPEND("EXCL")
293
294 return ret;
295 }
296
297 /* handle handles */
298
299 typedef struct Handle Handle;
300 struct Handle {
301 int use;
302 DIR *dirp;
303 int fd;
304 int flags;
305 char *name;
306 u_int64_t bytes_read, bytes_write;
307 int next_unused;
308 };
309
310 enum {
311 HANDLE_UNUSED,
312 HANDLE_DIR,
313 HANDLE_FILE
314 };
315
316 static Handle *handles = NULL;
317 static u_int num_handles = 0;
318 static int first_unused_handle = -1;
319
handle_unused(int i)320 static void handle_unused(int i)
321 {
322 handles[i].use = HANDLE_UNUSED;
323 handles[i].next_unused = first_unused_handle;
324 first_unused_handle = i;
325 }
326
327 static int
handle_new(int use,const char * name,int fd,int flags,DIR * dirp)328 handle_new(int use, const char *name, int fd, int flags, DIR *dirp)
329 {
330 int i;
331
332 if (first_unused_handle == -1) {
333 if (num_handles + 1 <= num_handles)
334 return -1;
335 num_handles++;
336 handles = xreallocarray(handles, num_handles, sizeof(Handle));
337 handle_unused(num_handles - 1);
338 }
339
340 i = first_unused_handle;
341 first_unused_handle = handles[i].next_unused;
342
343 handles[i].use = use;
344 handles[i].dirp = dirp;
345 handles[i].fd = fd;
346 handles[i].flags = flags;
347 handles[i].name = xstrdup(name);
348 handles[i].bytes_read = handles[i].bytes_write = 0;
349
350 return i;
351 }
352
353 static int
handle_is_ok(int i,int type)354 handle_is_ok(int i, int type)
355 {
356 return i >= 0 && (u_int)i < num_handles && handles[i].use == type;
357 }
358
359 static int
handle_to_string(int handle,u_char ** stringp,int * hlenp)360 handle_to_string(int handle, u_char **stringp, int *hlenp)
361 {
362 if (stringp == NULL || hlenp == NULL)
363 return -1;
364 *stringp = xmalloc(sizeof(int32_t));
365 put_u32(*stringp, handle);
366 *hlenp = sizeof(int32_t);
367 return 0;
368 }
369
370 static int
handle_from_string(const u_char * handle,u_int hlen)371 handle_from_string(const u_char *handle, u_int hlen)
372 {
373 int val;
374
375 if (hlen != sizeof(int32_t))
376 return -1;
377 val = get_u32(handle);
378 if (handle_is_ok(val, HANDLE_FILE) ||
379 handle_is_ok(val, HANDLE_DIR))
380 return val;
381 return -1;
382 }
383
384 static char *
handle_to_name(int handle)385 handle_to_name(int handle)
386 {
387 if (handle_is_ok(handle, HANDLE_DIR)||
388 handle_is_ok(handle, HANDLE_FILE))
389 return handles[handle].name;
390 return NULL;
391 }
392
393 static DIR *
handle_to_dir(int handle)394 handle_to_dir(int handle)
395 {
396 if (handle_is_ok(handle, HANDLE_DIR))
397 return handles[handle].dirp;
398 return NULL;
399 }
400
401 static int
handle_to_fd(int handle)402 handle_to_fd(int handle)
403 {
404 if (handle_is_ok(handle, HANDLE_FILE))
405 return handles[handle].fd;
406 return -1;
407 }
408
409 static int
handle_to_flags(int handle)410 handle_to_flags(int handle)
411 {
412 if (handle_is_ok(handle, HANDLE_FILE))
413 return handles[handle].flags;
414 return 0;
415 }
416
417 static void
handle_update_read(int handle,ssize_t bytes)418 handle_update_read(int handle, ssize_t bytes)
419 {
420 if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
421 handles[handle].bytes_read += bytes;
422 }
423
424 static void
handle_update_write(int handle,ssize_t bytes)425 handle_update_write(int handle, ssize_t bytes)
426 {
427 if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
428 handles[handle].bytes_write += bytes;
429 }
430
431 static u_int64_t
handle_bytes_read(int handle)432 handle_bytes_read(int handle)
433 {
434 if (handle_is_ok(handle, HANDLE_FILE))
435 return (handles[handle].bytes_read);
436 return 0;
437 }
438
439 static u_int64_t
handle_bytes_write(int handle)440 handle_bytes_write(int handle)
441 {
442 if (handle_is_ok(handle, HANDLE_FILE))
443 return (handles[handle].bytes_write);
444 return 0;
445 }
446
447 static int
handle_close(int handle)448 handle_close(int handle)
449 {
450 int ret = -1;
451
452 if (handle_is_ok(handle, HANDLE_FILE)) {
453 ret = close(handles[handle].fd);
454 free(handles[handle].name);
455 handle_unused(handle);
456 } else if (handle_is_ok(handle, HANDLE_DIR)) {
457 ret = closedir(handles[handle].dirp);
458 free(handles[handle].name);
459 handle_unused(handle);
460 } else {
461 errno = ENOENT;
462 }
463 return ret;
464 }
465
466 static void
handle_log_close(int handle,char * emsg)467 handle_log_close(int handle, char *emsg)
468 {
469 if (handle_is_ok(handle, HANDLE_FILE)) {
470 logit("%s%sclose \"%s\" bytes read %llu written %llu",
471 emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
472 handle_to_name(handle),
473 (unsigned long long)handle_bytes_read(handle),
474 (unsigned long long)handle_bytes_write(handle));
475 } else {
476 logit("%s%sclosedir \"%s\"",
477 emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
478 handle_to_name(handle));
479 }
480 }
481
482 static void
handle_log_exit(void)483 handle_log_exit(void)
484 {
485 u_int i;
486
487 for (i = 0; i < num_handles; i++)
488 if (handles[i].use != HANDLE_UNUSED)
489 handle_log_close(i, "forced");
490 }
491
492 static int
get_handle(struct sshbuf * queue,int * hp)493 get_handle(struct sshbuf *queue, int *hp)
494 {
495 u_char *handle;
496 int r;
497 size_t hlen;
498
499 *hp = -1;
500 if ((r = sshbuf_get_string(queue, &handle, &hlen)) != 0)
501 return r;
502 if (hlen < 256)
503 *hp = handle_from_string(handle, hlen);
504 free(handle);
505 return 0;
506 }
507
508 /* send replies */
509
510 static void
send_msg(struct sshbuf * m)511 send_msg(struct sshbuf *m)
512 {
513 int r;
514
515 if ((r = sshbuf_put_stringb(oqueue, m)) != 0)
516 fatal_fr(r, "enqueue");
517 sshbuf_reset(m);
518 }
519
520 static const char *
status_to_message(u_int32_t status)521 status_to_message(u_int32_t status)
522 {
523 static const char * const status_messages[] = {
524 "Success", /* SSH_FX_OK */
525 "End of file", /* SSH_FX_EOF */
526 "No such file", /* SSH_FX_NO_SUCH_FILE */
527 "Permission denied", /* SSH_FX_PERMISSION_DENIED */
528 "Failure", /* SSH_FX_FAILURE */
529 "Bad message", /* SSH_FX_BAD_MESSAGE */
530 "No connection", /* SSH_FX_NO_CONNECTION */
531 "Connection lost", /* SSH_FX_CONNECTION_LOST */
532 "Operation unsupported", /* SSH_FX_OP_UNSUPPORTED */
533 "Unknown error" /* Others */
534 };
535 return (status_messages[MINIMUM(status,SSH2_FX_MAX)]);
536 }
537
538 static void
send_status_errmsg(u_int32_t id,u_int32_t status,const char * errmsg)539 send_status_errmsg(u_int32_t id, u_int32_t status, const char *errmsg)
540 {
541 struct sshbuf *msg;
542 int r;
543
544 debug3("request %u: sent status %u", id, status);
545 if (log_level > SYSLOG_LEVEL_VERBOSE ||
546 (status != SSH2_FX_OK && status != SSH2_FX_EOF))
547 logit("sent status %s", status_to_message(status));
548 if ((msg = sshbuf_new()) == NULL)
549 fatal_f("sshbuf_new failed");
550 if ((r = sshbuf_put_u8(msg, SSH2_FXP_STATUS)) != 0 ||
551 (r = sshbuf_put_u32(msg, id)) != 0 ||
552 (r = sshbuf_put_u32(msg, status)) != 0)
553 fatal_fr(r, "compose");
554 if (version >= 3) {
555 if ((r = sshbuf_put_cstring(msg, errmsg == NULL ?
556 status_to_message(status) : errmsg)) != 0 ||
557 (r = sshbuf_put_cstring(msg, "")) != 0)
558 fatal_fr(r, "compose message");
559 }
560 send_msg(msg);
561 sshbuf_free(msg);
562 }
563
564 static void
send_status(u_int32_t id,u_int32_t status)565 send_status(u_int32_t id, u_int32_t status)
566 {
567 send_status_errmsg(id, status, NULL);
568 }
569
570 static void
send_data_or_handle(char type,u_int32_t id,const u_char * data,int dlen)571 send_data_or_handle(char type, u_int32_t id, const u_char *data, int dlen)
572 {
573 struct sshbuf *msg;
574 int r;
575
576 if ((msg = sshbuf_new()) == NULL)
577 fatal_f("sshbuf_new failed");
578 if ((r = sshbuf_put_u8(msg, type)) != 0 ||
579 (r = sshbuf_put_u32(msg, id)) != 0 ||
580 (r = sshbuf_put_string(msg, data, dlen)) != 0)
581 fatal_fr(r, "compose");
582 send_msg(msg);
583 sshbuf_free(msg);
584 }
585
586 static void
send_data(u_int32_t id,const u_char * data,int dlen)587 send_data(u_int32_t id, const u_char *data, int dlen)
588 {
589 debug("request %u: sent data len %d", id, dlen);
590 send_data_or_handle(SSH2_FXP_DATA, id, data, dlen);
591 }
592
593 static void
send_handle(u_int32_t id,int handle)594 send_handle(u_int32_t id, int handle)
595 {
596 u_char *string;
597 int hlen;
598
599 handle_to_string(handle, &string, &hlen);
600 debug("request %u: sent handle %d", id, handle);
601 send_data_or_handle(SSH2_FXP_HANDLE, id, string, hlen);
602 free(string);
603 }
604
605 static void
send_names(u_int32_t id,int count,const Stat * stats)606 send_names(u_int32_t id, int count, const Stat *stats)
607 {
608 struct sshbuf *msg;
609 int i, r;
610
611 if ((msg = sshbuf_new()) == NULL)
612 fatal_f("sshbuf_new failed");
613 if ((r = sshbuf_put_u8(msg, SSH2_FXP_NAME)) != 0 ||
614 (r = sshbuf_put_u32(msg, id)) != 0 ||
615 (r = sshbuf_put_u32(msg, count)) != 0)
616 fatal_fr(r, "compose");
617 debug("request %u: sent names count %d", id, count);
618 for (i = 0; i < count; i++) {
619 if ((r = sshbuf_put_cstring(msg, stats[i].name)) != 0 ||
620 (r = sshbuf_put_cstring(msg, stats[i].long_name)) != 0 ||
621 (r = encode_attrib(msg, &stats[i].attrib)) != 0)
622 fatal_fr(r, "compose filenames/attrib");
623 }
624 send_msg(msg);
625 sshbuf_free(msg);
626 }
627
628 static void
send_attrib(u_int32_t id,const Attrib * a)629 send_attrib(u_int32_t id, const Attrib *a)
630 {
631 struct sshbuf *msg;
632 int r;
633
634 debug("request %u: sent attrib have 0x%x", id, a->flags);
635 if ((msg = sshbuf_new()) == NULL)
636 fatal_f("sshbuf_new failed");
637 if ((r = sshbuf_put_u8(msg, SSH2_FXP_ATTRS)) != 0 ||
638 (r = sshbuf_put_u32(msg, id)) != 0 ||
639 (r = encode_attrib(msg, a)) != 0)
640 fatal_fr(r, "compose");
641 send_msg(msg);
642 sshbuf_free(msg);
643 }
644
645 static void
send_statvfs(u_int32_t id,struct statvfs * st)646 send_statvfs(u_int32_t id, struct statvfs *st)
647 {
648 struct sshbuf *msg;
649 u_int64_t flag;
650 int r;
651
652 flag = (st->f_flag & ST_RDONLY) ? SSH2_FXE_STATVFS_ST_RDONLY : 0;
653 flag |= (st->f_flag & ST_NOSUID) ? SSH2_FXE_STATVFS_ST_NOSUID : 0;
654
655 if ((msg = sshbuf_new()) == NULL)
656 fatal_f("sshbuf_new failed");
657 if ((r = sshbuf_put_u8(msg, SSH2_FXP_EXTENDED_REPLY)) != 0 ||
658 (r = sshbuf_put_u32(msg, id)) != 0 ||
659 (r = sshbuf_put_u64(msg, st->f_bsize)) != 0 ||
660 (r = sshbuf_put_u64(msg, st->f_frsize)) != 0 ||
661 (r = sshbuf_put_u64(msg, st->f_blocks)) != 0 ||
662 (r = sshbuf_put_u64(msg, st->f_bfree)) != 0 ||
663 (r = sshbuf_put_u64(msg, st->f_bavail)) != 0 ||
664 (r = sshbuf_put_u64(msg, st->f_files)) != 0 ||
665 (r = sshbuf_put_u64(msg, st->f_ffree)) != 0 ||
666 (r = sshbuf_put_u64(msg, st->f_favail)) != 0 ||
667 (r = sshbuf_put_u64(msg, st->f_fsid)) != 0 ||
668 (r = sshbuf_put_u64(msg, flag)) != 0 ||
669 (r = sshbuf_put_u64(msg, st->f_namemax)) != 0)
670 fatal_fr(r, "compose");
671 send_msg(msg);
672 sshbuf_free(msg);
673 }
674
675 /*
676 * Prepare SSH2_FXP_VERSION extension advertisement for a single extension.
677 * The extension is checked for permission prior to advertisement.
678 */
679 static int
compose_extension(struct sshbuf * msg,const char * name,const char * ver)680 compose_extension(struct sshbuf *msg, const char *name, const char *ver)
681 {
682 int r;
683 const struct sftp_handler *exthnd;
684
685 if ((exthnd = extended_handler_byname(name)) == NULL)
686 fatal_f("internal error: no handler for %s", name);
687 if (!request_permitted(exthnd)) {
688 debug2_f("refusing to advertise disallowed extension %s", name);
689 return 0;
690 }
691 if ((r = sshbuf_put_cstring(msg, name)) != 0 ||
692 (r = sshbuf_put_cstring(msg, ver)) != 0)
693 fatal_fr(r, "compose %s", name);
694 return 0;
695 }
696
697 /* parse incoming */
698
699 static void
process_init(void)700 process_init(void)
701 {
702 struct sshbuf *msg;
703 int r;
704
705 if ((r = sshbuf_get_u32(iqueue, &version)) != 0)
706 fatal_fr(r, "parse");
707 verbose("received client version %u", version);
708 if ((msg = sshbuf_new()) == NULL)
709 fatal_f("sshbuf_new failed");
710 if ((r = sshbuf_put_u8(msg, SSH2_FXP_VERSION)) != 0 ||
711 (r = sshbuf_put_u32(msg, SSH2_FILEXFER_VERSION)) != 0)
712 fatal_fr(r, "compose");
713
714 /* extension advertisements */
715 compose_extension(msg, "posix-rename@openssh.com", "1");
716 compose_extension(msg, "statvfs@openssh.com", "2");
717 compose_extension(msg, "fstatvfs@openssh.com", "2");
718 compose_extension(msg, "hardlink@openssh.com", "1");
719 compose_extension(msg, "fsync@openssh.com", "1");
720 compose_extension(msg, "lsetstat@openssh.com", "1");
721 compose_extension(msg, "limits@openssh.com", "1");
722 compose_extension(msg, "expand-path@openssh.com", "1");
723 compose_extension(msg, "copy-data", "1");
724 compose_extension(msg, "home-directory", "1");
725 compose_extension(msg, "users-groups-by-id@openssh.com", "1");
726
727 send_msg(msg);
728 sshbuf_free(msg);
729 }
730
731 static void
process_open(u_int32_t id)732 process_open(u_int32_t id)
733 {
734 u_int32_t pflags;
735 Attrib a;
736 char *name;
737 int r, handle, fd, flags, mode, status = SSH2_FX_FAILURE;
738
739 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
740 (r = sshbuf_get_u32(iqueue, &pflags)) != 0 || /* portable flags */
741 (r = decode_attrib(iqueue, &a)) != 0)
742 fatal_fr(r, "parse");
743
744 debug3("request %u: open flags %d", id, pflags);
745 flags = flags_from_portable(pflags);
746 mode = (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? a.perm : 0666;
747 logit("open \"%s\" flags %s mode 0%o",
748 name, string_from_portable(pflags), mode);
749 if (readonly &&
750 ((flags & O_ACCMODE) != O_RDONLY ||
751 (flags & (O_CREAT|O_TRUNC)) != 0)) {
752 verbose("Refusing open request in read-only mode");
753 status = SSH2_FX_PERMISSION_DENIED;
754 } else {
755 fd = open(name, flags, mode);
756 if (fd == -1) {
757 status = errno_to_portable(errno);
758 } else {
759 handle = handle_new(HANDLE_FILE, name, fd, flags, NULL);
760 if (handle < 0) {
761 close(fd);
762 } else {
763 send_handle(id, handle);
764 status = SSH2_FX_OK;
765 }
766 }
767 }
768 if (status != SSH2_FX_OK)
769 send_status(id, status);
770 free(name);
771 }
772
773 static void
process_close(u_int32_t id)774 process_close(u_int32_t id)
775 {
776 int r, handle, ret, status = SSH2_FX_FAILURE;
777
778 if ((r = get_handle(iqueue, &handle)) != 0)
779 fatal_fr(r, "parse");
780
781 debug3("request %u: close handle %u", id, handle);
782 handle_log_close(handle, NULL);
783 ret = handle_close(handle);
784 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
785 send_status(id, status);
786 }
787
788 static void
process_read(u_int32_t id)789 process_read(u_int32_t id)
790 {
791 static u_char *buf;
792 static size_t buflen;
793 u_int32_t len;
794 int r, handle, fd, ret, status = SSH2_FX_FAILURE;
795 u_int64_t off;
796
797 if ((r = get_handle(iqueue, &handle)) != 0 ||
798 (r = sshbuf_get_u64(iqueue, &off)) != 0 ||
799 (r = sshbuf_get_u32(iqueue, &len)) != 0)
800 fatal_fr(r, "parse");
801
802 debug("request %u: read \"%s\" (handle %d) off %llu len %u",
803 id, handle_to_name(handle), handle, (unsigned long long)off, len);
804 if ((fd = handle_to_fd(handle)) == -1)
805 goto out;
806 if (len > SFTP_MAX_READ_LENGTH) {
807 debug2("read change len %u to %u", len, SFTP_MAX_READ_LENGTH);
808 len = SFTP_MAX_READ_LENGTH;
809 }
810 if (len > buflen) {
811 debug3_f("allocate %zu => %u", buflen, len);
812 if ((buf = realloc(buf, len)) == NULL)
813 fatal_f("realloc failed");
814 buflen = len;
815 }
816 if (lseek(fd, off, SEEK_SET) == -1) {
817 status = errno_to_portable(errno);
818 error_f("seek \"%.100s\": %s", handle_to_name(handle),
819 strerror(errno));
820 goto out;
821 }
822 if (len == 0) {
823 /* weird, but not strictly disallowed */
824 ret = 0;
825 } else if ((ret = read(fd, buf, len)) == -1) {
826 status = errno_to_portable(errno);
827 error_f("read \"%.100s\": %s", handle_to_name(handle),
828 strerror(errno));
829 goto out;
830 } else if (ret == 0) {
831 status = SSH2_FX_EOF;
832 goto out;
833 }
834 send_data(id, buf, ret);
835 handle_update_read(handle, ret);
836 /* success */
837 status = SSH2_FX_OK;
838 out:
839 if (status != SSH2_FX_OK)
840 send_status(id, status);
841 }
842
843 static void
process_write(u_int32_t id)844 process_write(u_int32_t id)
845 {
846 u_int64_t off;
847 size_t len;
848 int r, handle, fd, ret, status;
849 u_char *data;
850
851 if ((r = get_handle(iqueue, &handle)) != 0 ||
852 (r = sshbuf_get_u64(iqueue, &off)) != 0 ||
853 (r = sshbuf_get_string(iqueue, &data, &len)) != 0)
854 fatal_fr(r, "parse");
855
856 debug("request %u: write \"%s\" (handle %d) off %llu len %zu",
857 id, handle_to_name(handle), handle, (unsigned long long)off, len);
858 fd = handle_to_fd(handle);
859
860 if (fd < 0)
861 status = SSH2_FX_FAILURE;
862 else {
863 if (!(handle_to_flags(handle) & O_APPEND) &&
864 lseek(fd, off, SEEK_SET) == -1) {
865 status = errno_to_portable(errno);
866 error_f("seek \"%.100s\": %s", handle_to_name(handle),
867 strerror(errno));
868 } else {
869 /* XXX ATOMICIO ? */
870 ret = write(fd, data, len);
871 if (ret == -1) {
872 status = errno_to_portable(errno);
873 error_f("write \"%.100s\": %s",
874 handle_to_name(handle), strerror(errno));
875 } else if ((size_t)ret == len) {
876 status = SSH2_FX_OK;
877 handle_update_write(handle, ret);
878 } else {
879 debug2_f("nothing at all written");
880 status = SSH2_FX_FAILURE;
881 }
882 }
883 }
884 send_status(id, status);
885 free(data);
886 }
887
888 static void
process_do_stat(u_int32_t id,int do_lstat)889 process_do_stat(u_int32_t id, int do_lstat)
890 {
891 Attrib a;
892 struct stat st;
893 char *name;
894 int r, status = SSH2_FX_FAILURE;
895
896 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
897 fatal_fr(r, "parse");
898
899 debug3("request %u: %sstat", id, do_lstat ? "l" : "");
900 verbose("%sstat name \"%s\"", do_lstat ? "l" : "", name);
901 r = do_lstat ? lstat(name, &st) : stat(name, &st);
902 if (r == -1) {
903 status = errno_to_portable(errno);
904 } else {
905 stat_to_attrib(&st, &a);
906 send_attrib(id, &a);
907 status = SSH2_FX_OK;
908 }
909 if (status != SSH2_FX_OK)
910 send_status(id, status);
911 free(name);
912 }
913
914 static void
process_stat(u_int32_t id)915 process_stat(u_int32_t id)
916 {
917 process_do_stat(id, 0);
918 }
919
920 static void
process_lstat(u_int32_t id)921 process_lstat(u_int32_t id)
922 {
923 process_do_stat(id, 1);
924 }
925
926 static void
process_fstat(u_int32_t id)927 process_fstat(u_int32_t id)
928 {
929 Attrib a;
930 struct stat st;
931 int fd, r, handle, status = SSH2_FX_FAILURE;
932
933 if ((r = get_handle(iqueue, &handle)) != 0)
934 fatal_fr(r, "parse");
935 debug("request %u: fstat \"%s\" (handle %u)",
936 id, handle_to_name(handle), handle);
937 fd = handle_to_fd(handle);
938 if (fd >= 0) {
939 r = fstat(fd, &st);
940 if (r == -1) {
941 status = errno_to_portable(errno);
942 } else {
943 stat_to_attrib(&st, &a);
944 send_attrib(id, &a);
945 status = SSH2_FX_OK;
946 }
947 }
948 if (status != SSH2_FX_OK)
949 send_status(id, status);
950 }
951
952 static struct timeval *
attrib_to_tv(const Attrib * a)953 attrib_to_tv(const Attrib *a)
954 {
955 static struct timeval tv[2];
956
957 tv[0].tv_sec = a->atime;
958 tv[0].tv_usec = 0;
959 tv[1].tv_sec = a->mtime;
960 tv[1].tv_usec = 0;
961 return tv;
962 }
963
964 static struct timespec *
attrib_to_ts(const Attrib * a)965 attrib_to_ts(const Attrib *a)
966 {
967 static struct timespec ts[2];
968
969 ts[0].tv_sec = a->atime;
970 ts[0].tv_nsec = 0;
971 ts[1].tv_sec = a->mtime;
972 ts[1].tv_nsec = 0;
973 return ts;
974 }
975
976 static void
process_setstat(u_int32_t id)977 process_setstat(u_int32_t id)
978 {
979 Attrib a;
980 char *name;
981 int r, status = SSH2_FX_OK;
982
983 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
984 (r = decode_attrib(iqueue, &a)) != 0)
985 fatal_fr(r, "parse");
986
987 debug("request %u: setstat name \"%s\"", id, name);
988 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) {
989 logit("set \"%s\" size %llu",
990 name, (unsigned long long)a.size);
991 r = truncate(name, a.size);
992 if (r == -1)
993 status = errno_to_portable(errno);
994 }
995 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
996 logit("set \"%s\" mode %04o", name, a.perm);
997 r = chmod(name, a.perm & 07777);
998 if (r == -1)
999 status = errno_to_portable(errno);
1000 }
1001 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
1002 char buf[64];
1003 time_t t = a.mtime;
1004
1005 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
1006 localtime(&t));
1007 logit("set \"%s\" modtime %s", name, buf);
1008 r = utimes(name, attrib_to_tv(&a));
1009 if (r == -1)
1010 status = errno_to_portable(errno);
1011 }
1012 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) {
1013 logit("set \"%s\" owner %lu group %lu", name,
1014 (u_long)a.uid, (u_long)a.gid);
1015 r = chown(name, a.uid, a.gid);
1016 if (r == -1)
1017 status = errno_to_portable(errno);
1018 }
1019 send_status(id, status);
1020 free(name);
1021 }
1022
1023 static void
process_fsetstat(u_int32_t id)1024 process_fsetstat(u_int32_t id)
1025 {
1026 Attrib a;
1027 int handle, fd, r;
1028 int status = SSH2_FX_OK;
1029
1030 if ((r = get_handle(iqueue, &handle)) != 0 ||
1031 (r = decode_attrib(iqueue, &a)) != 0)
1032 fatal_fr(r, "parse");
1033
1034 debug("request %u: fsetstat handle %d", id, handle);
1035 fd = handle_to_fd(handle);
1036 if (fd < 0)
1037 status = SSH2_FX_FAILURE;
1038 else {
1039 char *name = handle_to_name(handle);
1040
1041 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) {
1042 logit("set \"%s\" size %llu",
1043 name, (unsigned long long)a.size);
1044 r = ftruncate(fd, a.size);
1045 if (r == -1)
1046 status = errno_to_portable(errno);
1047 }
1048 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
1049 logit("set \"%s\" mode %04o", name, a.perm);
1050 r = fchmod(fd, a.perm & 07777);
1051 if (r == -1)
1052 status = errno_to_portable(errno);
1053 }
1054 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
1055 char buf[64];
1056 time_t t = a.mtime;
1057
1058 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
1059 localtime(&t));
1060 logit("set \"%s\" modtime %s", name, buf);
1061 r = futimes(fd, attrib_to_tv(&a));
1062 if (r == -1)
1063 status = errno_to_portable(errno);
1064 }
1065 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) {
1066 logit("set \"%s\" owner %lu group %lu", name,
1067 (u_long)a.uid, (u_long)a.gid);
1068 r = fchown(fd, a.uid, a.gid);
1069 if (r == -1)
1070 status = errno_to_portable(errno);
1071 }
1072 }
1073 send_status(id, status);
1074 }
1075
1076 static void
process_opendir(u_int32_t id)1077 process_opendir(u_int32_t id)
1078 {
1079 DIR *dirp = NULL;
1080 char *path;
1081 int r, handle, status = SSH2_FX_FAILURE;
1082
1083 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1084 fatal_fr(r, "parse");
1085
1086 debug3("request %u: opendir", id);
1087 logit("opendir \"%s\"", path);
1088 dirp = opendir(path);
1089 if (dirp == NULL) {
1090 status = errno_to_portable(errno);
1091 } else {
1092 handle = handle_new(HANDLE_DIR, path, 0, 0, dirp);
1093 if (handle < 0) {
1094 closedir(dirp);
1095 } else {
1096 send_handle(id, handle);
1097 status = SSH2_FX_OK;
1098 }
1099
1100 }
1101 if (status != SSH2_FX_OK)
1102 send_status(id, status);
1103 free(path);
1104 }
1105
1106 static void
process_readdir(u_int32_t id)1107 process_readdir(u_int32_t id)
1108 {
1109 DIR *dirp;
1110 struct dirent *dp;
1111 char *path;
1112 int r, handle;
1113
1114 if ((r = get_handle(iqueue, &handle)) != 0)
1115 fatal_fr(r, "parse");
1116
1117 debug("request %u: readdir \"%s\" (handle %d)", id,
1118 handle_to_name(handle), handle);
1119 dirp = handle_to_dir(handle);
1120 path = handle_to_name(handle);
1121 if (dirp == NULL || path == NULL) {
1122 send_status(id, SSH2_FX_FAILURE);
1123 } else {
1124 struct stat st;
1125 char pathname[PATH_MAX];
1126 Stat *stats;
1127 int nstats = 10, count = 0, i;
1128
1129 stats = xcalloc(nstats, sizeof(Stat));
1130 while ((dp = readdir(dirp)) != NULL) {
1131 if (count >= nstats) {
1132 nstats *= 2;
1133 stats = xreallocarray(stats, nstats, sizeof(Stat));
1134 }
1135 /* XXX OVERFLOW ? */
1136 snprintf(pathname, sizeof pathname, "%s%s%s", path,
1137 strcmp(path, "/") ? "/" : "", dp->d_name);
1138 if (lstat(pathname, &st) == -1)
1139 continue;
1140 stat_to_attrib(&st, &(stats[count].attrib));
1141 stats[count].name = xstrdup(dp->d_name);
1142 stats[count].long_name = ls_file(dp->d_name, &st,
1143 0, 0, NULL, NULL);
1144 count++;
1145 /* send up to 100 entries in one message */
1146 /* XXX check packet size instead */
1147 if (count == 100)
1148 break;
1149 }
1150 if (count > 0) {
1151 send_names(id, count, stats);
1152 for (i = 0; i < count; i++) {
1153 free(stats[i].name);
1154 free(stats[i].long_name);
1155 }
1156 } else {
1157 send_status(id, SSH2_FX_EOF);
1158 }
1159 free(stats);
1160 }
1161 }
1162
1163 static void
process_remove(u_int32_t id)1164 process_remove(u_int32_t id)
1165 {
1166 char *name;
1167 int r, status = SSH2_FX_FAILURE;
1168
1169 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
1170 fatal_fr(r, "parse");
1171
1172 debug3("request %u: remove", id);
1173 logit("remove name \"%s\"", name);
1174 r = unlink(name);
1175 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1176 send_status(id, status);
1177 free(name);
1178 }
1179
1180 static void
process_mkdir(u_int32_t id)1181 process_mkdir(u_int32_t id)
1182 {
1183 Attrib a;
1184 char *name;
1185 int r, mode, status = SSH2_FX_FAILURE;
1186
1187 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
1188 (r = decode_attrib(iqueue, &a)) != 0)
1189 fatal_fr(r, "parse");
1190
1191 mode = (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ?
1192 a.perm & 07777 : 0777;
1193 debug3("request %u: mkdir", id);
1194 logit("mkdir name \"%s\" mode 0%o", name, mode);
1195 r = mkdir(name, mode);
1196 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1197 send_status(id, status);
1198 free(name);
1199 }
1200
1201 static void
process_rmdir(u_int32_t id)1202 process_rmdir(u_int32_t id)
1203 {
1204 char *name;
1205 int r, status;
1206
1207 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
1208 fatal_fr(r, "parse");
1209
1210 debug3("request %u: rmdir", id);
1211 logit("rmdir name \"%s\"", name);
1212 r = rmdir(name);
1213 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1214 send_status(id, status);
1215 free(name);
1216 }
1217
1218 static void
process_realpath(u_int32_t id)1219 process_realpath(u_int32_t id)
1220 {
1221 char resolvedname[PATH_MAX];
1222 char *path;
1223 int r;
1224
1225 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1226 fatal_fr(r, "parse");
1227
1228 if (path[0] == '\0') {
1229 free(path);
1230 path = xstrdup(".");
1231 }
1232 debug3("request %u: realpath", id);
1233 verbose("realpath \"%s\"", path);
1234 if (sftp_realpath(path, resolvedname) == NULL) {
1235 send_status(id, errno_to_portable(errno));
1236 } else {
1237 Stat s;
1238 attrib_clear(&s.attrib);
1239 s.name = s.long_name = resolvedname;
1240 send_names(id, 1, &s);
1241 }
1242 free(path);
1243 }
1244
1245 static void
process_rename(u_int32_t id)1246 process_rename(u_int32_t id)
1247 {
1248 char *oldpath, *newpath;
1249 int r, status;
1250 struct stat sb;
1251
1252 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
1253 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
1254 fatal_fr(r, "parse");
1255
1256 debug3("request %u: rename", id);
1257 logit("rename old \"%s\" new \"%s\"", oldpath, newpath);
1258 status = SSH2_FX_FAILURE;
1259 if (lstat(oldpath, &sb) == -1)
1260 status = errno_to_portable(errno);
1261 else if (S_ISREG(sb.st_mode)) {
1262 /* Race-free rename of regular files */
1263 if (link(oldpath, newpath) == -1) {
1264 if (errno == EOPNOTSUPP) {
1265 struct stat st;
1266
1267 /*
1268 * fs doesn't support links, so fall back to
1269 * stat+rename. This is racy.
1270 */
1271 if (stat(newpath, &st) == -1) {
1272 if (rename(oldpath, newpath) == -1)
1273 status =
1274 errno_to_portable(errno);
1275 else
1276 status = SSH2_FX_OK;
1277 }
1278 } else {
1279 status = errno_to_portable(errno);
1280 }
1281 } else if (unlink(oldpath) == -1) {
1282 status = errno_to_portable(errno);
1283 /* clean spare link */
1284 unlink(newpath);
1285 } else
1286 status = SSH2_FX_OK;
1287 } else if (stat(newpath, &sb) == -1) {
1288 if (rename(oldpath, newpath) == -1)
1289 status = errno_to_portable(errno);
1290 else
1291 status = SSH2_FX_OK;
1292 }
1293 send_status(id, status);
1294 free(oldpath);
1295 free(newpath);
1296 }
1297
1298 static void
process_readlink(u_int32_t id)1299 process_readlink(u_int32_t id)
1300 {
1301 int r, len;
1302 char buf[PATH_MAX];
1303 char *path;
1304
1305 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1306 fatal_fr(r, "parse");
1307
1308 debug3("request %u: readlink", id);
1309 verbose("readlink \"%s\"", path);
1310 if ((len = readlink(path, buf, sizeof(buf) - 1)) == -1)
1311 send_status(id, errno_to_portable(errno));
1312 else {
1313 Stat s;
1314
1315 buf[len] = '\0';
1316 attrib_clear(&s.attrib);
1317 s.name = s.long_name = buf;
1318 send_names(id, 1, &s);
1319 }
1320 free(path);
1321 }
1322
1323 static void
process_symlink(u_int32_t id)1324 process_symlink(u_int32_t id)
1325 {
1326 char *oldpath, *newpath;
1327 int r, status;
1328
1329 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
1330 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
1331 fatal_fr(r, "parse");
1332
1333 debug3("request %u: symlink", id);
1334 logit("symlink old \"%s\" new \"%s\"", oldpath, newpath);
1335 /* this will fail if 'newpath' exists */
1336 r = symlink(oldpath, newpath);
1337 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1338 send_status(id, status);
1339 free(oldpath);
1340 free(newpath);
1341 }
1342
1343 static void
process_extended_posix_rename(u_int32_t id)1344 process_extended_posix_rename(u_int32_t id)
1345 {
1346 char *oldpath, *newpath;
1347 int r, status;
1348
1349 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
1350 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
1351 fatal_fr(r, "parse");
1352
1353 debug3("request %u: posix-rename", id);
1354 logit("posix-rename old \"%s\" new \"%s\"", oldpath, newpath);
1355 r = rename(oldpath, newpath);
1356 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1357 send_status(id, status);
1358 free(oldpath);
1359 free(newpath);
1360 }
1361
1362 static void
process_extended_statvfs(u_int32_t id)1363 process_extended_statvfs(u_int32_t id)
1364 {
1365 char *path;
1366 struct statvfs st;
1367 int r;
1368
1369 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1370 fatal_fr(r, "parse");
1371 debug3("request %u: statvfs", id);
1372 logit("statvfs \"%s\"", path);
1373
1374 if (statvfs(path, &st) != 0)
1375 send_status(id, errno_to_portable(errno));
1376 else
1377 send_statvfs(id, &st);
1378 free(path);
1379 }
1380
1381 static void
process_extended_fstatvfs(u_int32_t id)1382 process_extended_fstatvfs(u_int32_t id)
1383 {
1384 int r, handle, fd;
1385 struct statvfs st;
1386
1387 if ((r = get_handle(iqueue, &handle)) != 0)
1388 fatal_fr(r, "parse");
1389 debug("request %u: fstatvfs \"%s\" (handle %u)",
1390 id, handle_to_name(handle), handle);
1391 if ((fd = handle_to_fd(handle)) < 0) {
1392 send_status(id, SSH2_FX_FAILURE);
1393 return;
1394 }
1395 if (fstatvfs(fd, &st) != 0)
1396 send_status(id, errno_to_portable(errno));
1397 else
1398 send_statvfs(id, &st);
1399 }
1400
1401 static void
process_extended_hardlink(u_int32_t id)1402 process_extended_hardlink(u_int32_t id)
1403 {
1404 char *oldpath, *newpath;
1405 int r, status;
1406
1407 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
1408 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
1409 fatal_fr(r, "parse");
1410
1411 debug3("request %u: hardlink", id);
1412 logit("hardlink old \"%s\" new \"%s\"", oldpath, newpath);
1413 r = link(oldpath, newpath);
1414 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1415 send_status(id, status);
1416 free(oldpath);
1417 free(newpath);
1418 }
1419
1420 static void
process_extended_fsync(u_int32_t id)1421 process_extended_fsync(u_int32_t id)
1422 {
1423 int handle, fd, r, status = SSH2_FX_OP_UNSUPPORTED;
1424
1425 if ((r = get_handle(iqueue, &handle)) != 0)
1426 fatal_fr(r, "parse");
1427 debug3("request %u: fsync (handle %u)", id, handle);
1428 verbose("fsync \"%s\"", handle_to_name(handle));
1429 if ((fd = handle_to_fd(handle)) < 0)
1430 status = SSH2_FX_NO_SUCH_FILE;
1431 else if (handle_is_ok(handle, HANDLE_FILE)) {
1432 r = fsync(fd);
1433 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1434 }
1435 send_status(id, status);
1436 }
1437
1438 static void
process_extended_lsetstat(u_int32_t id)1439 process_extended_lsetstat(u_int32_t id)
1440 {
1441 Attrib a;
1442 char *name;
1443 int r, status = SSH2_FX_OK;
1444
1445 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
1446 (r = decode_attrib(iqueue, &a)) != 0)
1447 fatal_fr(r, "parse");
1448
1449 debug("request %u: lsetstat name \"%s\"", id, name);
1450 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) {
1451 /* nonsensical for links */
1452 status = SSH2_FX_BAD_MESSAGE;
1453 goto out;
1454 }
1455 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
1456 logit("set \"%s\" mode %04o", name, a.perm);
1457 r = fchmodat(AT_FDCWD, name,
1458 a.perm & 07777, AT_SYMLINK_NOFOLLOW);
1459 if (r == -1)
1460 status = errno_to_portable(errno);
1461 }
1462 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
1463 char buf[64];
1464 time_t t = a.mtime;
1465
1466 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
1467 localtime(&t));
1468 logit("set \"%s\" modtime %s", name, buf);
1469 r = utimensat(AT_FDCWD, name,
1470 attrib_to_ts(&a), AT_SYMLINK_NOFOLLOW);
1471 if (r == -1)
1472 status = errno_to_portable(errno);
1473 }
1474 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) {
1475 logit("set \"%s\" owner %lu group %lu", name,
1476 (u_long)a.uid, (u_long)a.gid);
1477 r = fchownat(AT_FDCWD, name, a.uid, a.gid,
1478 AT_SYMLINK_NOFOLLOW);
1479 if (r == -1)
1480 status = errno_to_portable(errno);
1481 }
1482 out:
1483 send_status(id, status);
1484 free(name);
1485 }
1486
1487 static void
process_extended_limits(u_int32_t id)1488 process_extended_limits(u_int32_t id)
1489 {
1490 struct sshbuf *msg;
1491 int r;
1492 uint64_t nfiles = 0;
1493 struct rlimit rlim;
1494
1495 debug("request %u: limits", id);
1496
1497 if (getrlimit(RLIMIT_NOFILE, &rlim) != -1 && rlim.rlim_cur > 5)
1498 nfiles = rlim.rlim_cur - 5; /* stdio(3) + syslog + spare */
1499
1500 if ((msg = sshbuf_new()) == NULL)
1501 fatal_f("sshbuf_new failed");
1502 if ((r = sshbuf_put_u8(msg, SSH2_FXP_EXTENDED_REPLY)) != 0 ||
1503 (r = sshbuf_put_u32(msg, id)) != 0 ||
1504 /* max-packet-length */
1505 (r = sshbuf_put_u64(msg, SFTP_MAX_MSG_LENGTH)) != 0 ||
1506 /* max-read-length */
1507 (r = sshbuf_put_u64(msg, SFTP_MAX_READ_LENGTH)) != 0 ||
1508 /* max-write-length */
1509 (r = sshbuf_put_u64(msg, SFTP_MAX_MSG_LENGTH - 1024)) != 0 ||
1510 /* max-open-handles */
1511 (r = sshbuf_put_u64(msg, nfiles)) != 0)
1512 fatal_fr(r, "compose");
1513 send_msg(msg);
1514 sshbuf_free(msg);
1515 }
1516
1517 static void
process_extended_expand(u_int32_t id)1518 process_extended_expand(u_int32_t id)
1519 {
1520 char cwd[PATH_MAX], resolvedname[PATH_MAX];
1521 char *path, *npath;
1522 int r;
1523 Stat s;
1524
1525 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
1526 fatal_fr(r, "parse");
1527 if (getcwd(cwd, sizeof(cwd)) == NULL) {
1528 send_status(id, errno_to_portable(errno));
1529 goto out;
1530 }
1531
1532 debug3("request %u: expand, original \"%s\"", id, path);
1533 if (path[0] == '\0') {
1534 /* empty path */
1535 free(path);
1536 path = xstrdup(".");
1537 } else if (*path == '~') {
1538 /* ~ expand path */
1539 /* Special-case for "~" and "~/" to respect homedir flag */
1540 if (strcmp(path, "~") == 0) {
1541 free(path);
1542 path = xstrdup(cwd);
1543 } else if (strncmp(path, "~/", 2) == 0) {
1544 npath = xstrdup(path + 2);
1545 free(path);
1546 xasprintf(&path, "%s/%s", cwd, npath);
1547 free(npath);
1548 } else {
1549 /* ~user expansions */
1550 if (tilde_expand(path, pw->pw_uid, &npath) != 0) {
1551 send_status_errmsg(id,
1552 errno_to_portable(ENOENT), "no such user");
1553 goto out;
1554 }
1555 free(path);
1556 path = npath;
1557 }
1558 } else if (*path != '/') {
1559 /* relative path */
1560 xasprintf(&npath, "%s/%s", cwd, path);
1561 free(path);
1562 path = npath;
1563 }
1564 verbose("expand \"%s\"", path);
1565 if (sftp_realpath(path, resolvedname) == NULL) {
1566 send_status(id, errno_to_portable(errno));
1567 goto out;
1568 }
1569 attrib_clear(&s.attrib);
1570 s.name = s.long_name = resolvedname;
1571 send_names(id, 1, &s);
1572 out:
1573 free(path);
1574 }
1575
1576 static void
process_extended_copy_data(u_int32_t id)1577 process_extended_copy_data(u_int32_t id)
1578 {
1579 u_char buf[64*1024];
1580 int read_handle, read_fd, write_handle, write_fd;
1581 u_int64_t len, read_off, read_len, write_off;
1582 int r, copy_until_eof, status = SSH2_FX_OP_UNSUPPORTED;
1583 size_t ret;
1584
1585 if ((r = get_handle(iqueue, &read_handle)) != 0 ||
1586 (r = sshbuf_get_u64(iqueue, &read_off)) != 0 ||
1587 (r = sshbuf_get_u64(iqueue, &read_len)) != 0 ||
1588 (r = get_handle(iqueue, &write_handle)) != 0 ||
1589 (r = sshbuf_get_u64(iqueue, &write_off)) != 0)
1590 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1591
1592 debug("request %u: copy-data from \"%s\" (handle %d) off %llu len %llu "
1593 "to \"%s\" (handle %d) off %llu",
1594 id, handle_to_name(read_handle), read_handle,
1595 (unsigned long long)read_off, (unsigned long long)read_len,
1596 handle_to_name(write_handle), write_handle,
1597 (unsigned long long)write_off);
1598
1599 /* For read length of 0, we read until EOF. */
1600 if (read_len == 0) {
1601 read_len = (u_int64_t)-1 - read_off;
1602 copy_until_eof = 1;
1603 } else
1604 copy_until_eof = 0;
1605
1606 read_fd = handle_to_fd(read_handle);
1607 write_fd = handle_to_fd(write_handle);
1608
1609 /* Disallow reading & writing to the same handle or same path or dirs */
1610 if (read_handle == write_handle || read_fd < 0 || write_fd < 0 ||
1611 !strcmp(handle_to_name(read_handle), handle_to_name(write_handle))) {
1612 status = SSH2_FX_FAILURE;
1613 goto out;
1614 }
1615
1616 if (lseek(read_fd, read_off, SEEK_SET) < 0) {
1617 status = errno_to_portable(errno);
1618 error("%s: read_seek failed", __func__);
1619 goto out;
1620 }
1621
1622 if ((handle_to_flags(write_handle) & O_APPEND) == 0 &&
1623 lseek(write_fd, write_off, SEEK_SET) < 0) {
1624 status = errno_to_portable(errno);
1625 error("%s: write_seek failed", __func__);
1626 goto out;
1627 }
1628
1629 /* Process the request in chunks. */
1630 while (read_len > 0 || copy_until_eof) {
1631 len = MINIMUM(sizeof(buf), read_len);
1632 read_len -= len;
1633
1634 ret = atomicio(read, read_fd, buf, len);
1635 if (ret == 0 && errno == EPIPE) {
1636 status = copy_until_eof ? SSH2_FX_OK : SSH2_FX_EOF;
1637 break;
1638 } else if (ret == 0) {
1639 status = errno_to_portable(errno);
1640 error("%s: read failed: %s", __func__, strerror(errno));
1641 break;
1642 }
1643 len = ret;
1644 handle_update_read(read_handle, len);
1645
1646 ret = atomicio(vwrite, write_fd, buf, len);
1647 if (ret != len) {
1648 status = errno_to_portable(errno);
1649 error("%s: write failed: %llu != %llu: %s", __func__,
1650 (unsigned long long)ret, (unsigned long long)len,
1651 strerror(errno));
1652 break;
1653 }
1654 handle_update_write(write_handle, len);
1655 }
1656
1657 if (read_len == 0)
1658 status = SSH2_FX_OK;
1659
1660 out:
1661 send_status(id, status);
1662 }
1663
1664 static void
process_extended_home_directory(u_int32_t id)1665 process_extended_home_directory(u_int32_t id)
1666 {
1667 char *username;
1668 struct passwd *user_pw;
1669 int r;
1670 Stat s;
1671
1672 if ((r = sshbuf_get_cstring(iqueue, &username, NULL)) != 0)
1673 fatal_fr(r, "parse");
1674
1675 debug3("request %u: home-directory \"%s\"", id, username);
1676 if (username[0] == '\0') {
1677 user_pw = pw;
1678 } else if ((user_pw = getpwnam(username)) == NULL) {
1679 send_status(id, SSH2_FX_FAILURE);
1680 goto out;
1681 }
1682
1683 verbose("home-directory \"%s\"", user_pw->pw_dir);
1684 attrib_clear(&s.attrib);
1685 s.name = s.long_name = user_pw->pw_dir;
1686 send_names(id, 1, &s);
1687 out:
1688 free(username);
1689 }
1690
1691 static void
process_extended_get_users_groups_by_id(u_int32_t id)1692 process_extended_get_users_groups_by_id(u_int32_t id)
1693 {
1694 struct passwd *user_pw;
1695 struct group *gr;
1696 struct sshbuf *uids, *gids, *usernames, *groupnames, *msg;
1697 int r;
1698 u_int n, nusers = 0, ngroups = 0;
1699 const char *name;
1700
1701 if ((usernames = sshbuf_new()) == NULL ||
1702 (groupnames = sshbuf_new()) == NULL ||
1703 (msg = sshbuf_new()) == NULL)
1704 fatal_f("sshbuf_new failed");
1705 if ((r = sshbuf_froms(iqueue, &uids)) != 0 ||
1706 (r = sshbuf_froms(iqueue, &gids)) != 0)
1707 fatal_fr(r, "parse");
1708 debug_f("uids len = %zu, gids len = %zu",
1709 sshbuf_len(uids), sshbuf_len(gids));
1710 while (sshbuf_len(uids) != 0) {
1711 if ((r = sshbuf_get_u32(uids, &n)) != 0)
1712 fatal_fr(r, "parse inner uid");
1713 user_pw = getpwuid((uid_t)n);
1714 name = user_pw == NULL ? "" : user_pw->pw_name;
1715 debug3_f("uid %u => \"%s\"", n, name);
1716 if ((r = sshbuf_put_cstring(usernames, name)) != 0)
1717 fatal_fr(r, "assemble uid reply");
1718 nusers++;
1719 }
1720 while (sshbuf_len(gids) != 0) {
1721 if ((r = sshbuf_get_u32(gids, &n)) != 0)
1722 fatal_fr(r, "parse inner gid");
1723 gr = getgrgid((gid_t)n);
1724 name = gr == NULL ? "" : gr->gr_name;
1725 debug3_f("gid %u => \"%s\"", n, name);
1726 if ((r = sshbuf_put_cstring(groupnames, name)) != 0)
1727 fatal_fr(r, "assemble gid reply");
1728 nusers++;
1729 }
1730 verbose("users-groups-by-id: %u users, %u groups", nusers, ngroups);
1731
1732 if ((r = sshbuf_put_u8(msg, SSH2_FXP_EXTENDED_REPLY)) != 0 ||
1733 (r = sshbuf_put_u32(msg, id)) != 0 ||
1734 (r = sshbuf_put_stringb(msg, usernames)) != 0 ||
1735 (r = sshbuf_put_stringb(msg, groupnames)) != 0)
1736 fatal_fr(r, "compose");
1737 send_msg(msg);
1738
1739 sshbuf_free(uids);
1740 sshbuf_free(gids);
1741 sshbuf_free(usernames);
1742 sshbuf_free(groupnames);
1743 sshbuf_free(msg);
1744 }
1745
1746 static void
process_extended(u_int32_t id)1747 process_extended(u_int32_t id)
1748 {
1749 char *request;
1750 int r;
1751 const struct sftp_handler *exthand;
1752
1753 if ((r = sshbuf_get_cstring(iqueue, &request, NULL)) != 0)
1754 fatal_fr(r, "parse");
1755 if ((exthand = extended_handler_byname(request)) == NULL) {
1756 error("Unknown extended request \"%.100s\"", request);
1757 send_status(id, SSH2_FX_OP_UNSUPPORTED); /* MUST */
1758 } else {
1759 if (!request_permitted(exthand))
1760 send_status(id, SSH2_FX_PERMISSION_DENIED);
1761 else
1762 exthand->handler(id);
1763 }
1764 free(request);
1765 }
1766
1767 /* stolen from ssh-agent */
1768
1769 static void
process(void)1770 process(void)
1771 {
1772 u_int msg_len;
1773 u_int buf_len;
1774 u_int consumed;
1775 u_char type;
1776 const u_char *cp;
1777 int i, r;
1778 u_int32_t id;
1779
1780 buf_len = sshbuf_len(iqueue);
1781 if (buf_len < 5)
1782 return; /* Incomplete message. */
1783 cp = sshbuf_ptr(iqueue);
1784 msg_len = get_u32(cp);
1785 if (msg_len > SFTP_MAX_MSG_LENGTH) {
1786 error("bad message from %s local user %s",
1787 client_addr, pw->pw_name);
1788 sftp_server_cleanup_exit(11);
1789 }
1790 if (buf_len < msg_len + 4)
1791 return;
1792 if ((r = sshbuf_consume(iqueue, 4)) != 0)
1793 fatal_fr(r, "consume");
1794 buf_len -= 4;
1795 if ((r = sshbuf_get_u8(iqueue, &type)) != 0)
1796 fatal_fr(r, "parse type");
1797
1798 switch (type) {
1799 case SSH2_FXP_INIT:
1800 process_init();
1801 init_done = 1;
1802 break;
1803 case SSH2_FXP_EXTENDED:
1804 if (!init_done)
1805 fatal("Received extended request before init");
1806 if ((r = sshbuf_get_u32(iqueue, &id)) != 0)
1807 fatal_fr(r, "parse extended ID");
1808 process_extended(id);
1809 break;
1810 default:
1811 if (!init_done)
1812 fatal("Received %u request before init", type);
1813 if ((r = sshbuf_get_u32(iqueue, &id)) != 0)
1814 fatal_fr(r, "parse ID");
1815 for (i = 0; handlers[i].handler != NULL; i++) {
1816 if (type == handlers[i].type) {
1817 if (!request_permitted(&handlers[i])) {
1818 send_status(id,
1819 SSH2_FX_PERMISSION_DENIED);
1820 } else {
1821 handlers[i].handler(id);
1822 }
1823 break;
1824 }
1825 }
1826 if (handlers[i].handler == NULL)
1827 error("Unknown message %u", type);
1828 }
1829 /* discard the remaining bytes from the current packet */
1830 if (buf_len < sshbuf_len(iqueue)) {
1831 error("iqueue grew unexpectedly");
1832 sftp_server_cleanup_exit(255);
1833 }
1834 consumed = buf_len - sshbuf_len(iqueue);
1835 if (msg_len < consumed) {
1836 error("msg_len %u < consumed %u", msg_len, consumed);
1837 sftp_server_cleanup_exit(255);
1838 }
1839 if (msg_len > consumed &&
1840 (r = sshbuf_consume(iqueue, msg_len - consumed)) != 0)
1841 fatal_fr(r, "consume");
1842 }
1843
1844 /* Cleanup handler that logs active handles upon normal exit */
1845 void
sftp_server_cleanup_exit(int i)1846 sftp_server_cleanup_exit(int i)
1847 {
1848 if (pw != NULL && client_addr != NULL) {
1849 handle_log_exit();
1850 logit("session closed for local user %s from [%s]",
1851 pw->pw_name, client_addr);
1852 }
1853 _exit(i);
1854 }
1855
1856 static void
sftp_server_usage(void)1857 sftp_server_usage(void)
1858 {
1859 extern char *__progname;
1860
1861 fprintf(stderr,
1862 "usage: %s [-ehR] [-d start_directory] [-f log_facility] "
1863 "[-l log_level]\n\t[-P denied_requests] "
1864 "[-p allowed_requests] [-u umask]\n"
1865 " %s -Q protocol_feature\n",
1866 __progname, __progname);
1867 exit(1);
1868 }
1869
1870 int
sftp_server_main(int argc,char ** argv,struct passwd * user_pw)1871 sftp_server_main(int argc, char **argv, struct passwd *user_pw)
1872 {
1873 int i, r, in, out, ch, skipargs = 0, log_stderr = 0;
1874 ssize_t len, olen;
1875 SyslogFacility log_facility = SYSLOG_FACILITY_AUTH;
1876 char *cp, *homedir = NULL, uidstr[32], buf[4*4096];
1877 long mask;
1878
1879 extern char *optarg;
1880 extern char *__progname;
1881
1882 log_init(__progname, log_level, log_facility, log_stderr);
1883
1884 pw = pwcopy(user_pw);
1885
1886 while (!skipargs && (ch = getopt(argc, argv,
1887 "d:f:l:P:p:Q:u:cehR")) != -1) {
1888 switch (ch) {
1889 case 'Q':
1890 if (strcasecmp(optarg, "requests") != 0) {
1891 fprintf(stderr, "Invalid query type\n");
1892 exit(1);
1893 }
1894 for (i = 0; handlers[i].handler != NULL; i++)
1895 printf("%s\n", handlers[i].name);
1896 for (i = 0; extended_handlers[i].handler != NULL; i++)
1897 printf("%s\n", extended_handlers[i].name);
1898 exit(0);
1899 break;
1900 case 'R':
1901 readonly = 1;
1902 break;
1903 case 'c':
1904 /*
1905 * Ignore all arguments if we are invoked as a
1906 * shell using "sftp-server -c command"
1907 */
1908 skipargs = 1;
1909 break;
1910 case 'e':
1911 log_stderr = 1;
1912 break;
1913 case 'l':
1914 log_level = log_level_number(optarg);
1915 if (log_level == SYSLOG_LEVEL_NOT_SET)
1916 error("Invalid log level \"%s\"", optarg);
1917 break;
1918 case 'f':
1919 log_facility = log_facility_number(optarg);
1920 if (log_facility == SYSLOG_FACILITY_NOT_SET)
1921 error("Invalid log facility \"%s\"", optarg);
1922 break;
1923 case 'd':
1924 cp = tilde_expand_filename(optarg, user_pw->pw_uid);
1925 snprintf(uidstr, sizeof(uidstr), "%llu",
1926 (unsigned long long)pw->pw_uid);
1927 homedir = percent_expand(cp, "d", user_pw->pw_dir,
1928 "u", user_pw->pw_name, "U", uidstr, (char *)NULL);
1929 free(cp);
1930 break;
1931 case 'p':
1932 if (request_allowlist != NULL)
1933 fatal("Permitted requests already set");
1934 request_allowlist = xstrdup(optarg);
1935 break;
1936 case 'P':
1937 if (request_denylist != NULL)
1938 fatal("Refused requests already set");
1939 request_denylist = xstrdup(optarg);
1940 break;
1941 case 'u':
1942 errno = 0;
1943 mask = strtol(optarg, &cp, 8);
1944 if (mask < 0 || mask > 0777 || *cp != '\0' ||
1945 cp == optarg || (mask == 0 && errno != 0))
1946 fatal("Invalid umask \"%s\"", optarg);
1947 (void)umask((mode_t)mask);
1948 break;
1949 case 'h':
1950 default:
1951 sftp_server_usage();
1952 }
1953 }
1954
1955 log_init(__progname, log_level, log_facility, log_stderr);
1956
1957 if ((cp = getenv("SSH_CONNECTION")) != NULL) {
1958 client_addr = xstrdup(cp);
1959 if ((cp = strchr(client_addr, ' ')) == NULL) {
1960 error("Malformed SSH_CONNECTION variable: \"%s\"",
1961 getenv("SSH_CONNECTION"));
1962 sftp_server_cleanup_exit(255);
1963 }
1964 *cp = '\0';
1965 } else
1966 client_addr = xstrdup("UNKNOWN");
1967
1968 logit("session opened for local user %s from [%s]",
1969 pw->pw_name, client_addr);
1970
1971 in = STDIN_FILENO;
1972 out = STDOUT_FILENO;
1973
1974 if ((iqueue = sshbuf_new()) == NULL)
1975 fatal_f("sshbuf_new failed");
1976 if ((oqueue = sshbuf_new()) == NULL)
1977 fatal_f("sshbuf_new failed");
1978
1979 if (homedir != NULL) {
1980 if (chdir(homedir) != 0) {
1981 error("chdir to \"%s\" failed: %s", homedir,
1982 strerror(errno));
1983 }
1984 }
1985
1986 for (;;) {
1987 struct pollfd pfd[2];
1988
1989 memset(pfd, 0, sizeof pfd);
1990 pfd[0].fd = pfd[1].fd = -1;
1991
1992 /*
1993 * Ensure that we can read a full buffer and handle
1994 * the worst-case length packet it can generate,
1995 * otherwise apply backpressure by stopping reads.
1996 */
1997 if ((r = sshbuf_check_reserve(iqueue, sizeof(buf))) == 0 &&
1998 (r = sshbuf_check_reserve(oqueue,
1999 SFTP_MAX_MSG_LENGTH)) == 0) {
2000 pfd[0].fd = in;
2001 pfd[0].events = POLLIN;
2002 }
2003 else if (r != SSH_ERR_NO_BUFFER_SPACE)
2004 fatal_fr(r, "reserve");
2005
2006 olen = sshbuf_len(oqueue);
2007 if (olen > 0) {
2008 pfd[1].fd = out;
2009 pfd[1].events = POLLOUT;
2010 }
2011
2012 if (poll(pfd, 2, -1) == -1) {
2013 if (errno == EINTR)
2014 continue;
2015 error("poll: %s", strerror(errno));
2016 sftp_server_cleanup_exit(2);
2017 }
2018
2019 /* copy stdin to iqueue */
2020 if (pfd[0].revents & (POLLIN|POLLHUP)) {
2021 len = read(in, buf, sizeof buf);
2022 if (len == 0) {
2023 debug("read eof");
2024 sftp_server_cleanup_exit(0);
2025 } else if (len == -1) {
2026 if (errno != EAGAIN && errno != EINTR) {
2027 error("read: %s", strerror(errno));
2028 sftp_server_cleanup_exit(1);
2029 }
2030 } else if ((r = sshbuf_put(iqueue, buf, len)) != 0)
2031 fatal_fr(r, "sshbuf_put");
2032 }
2033 /* send oqueue to stdout */
2034 if (pfd[1].revents & (POLLOUT|POLLHUP)) {
2035 len = write(out, sshbuf_ptr(oqueue), olen);
2036 if (len == 0 || (len == -1 && errno == EPIPE)) {
2037 debug("write eof");
2038 sftp_server_cleanup_exit(0);
2039 } else if (len == -1) {
2040 sftp_server_cleanup_exit(1);
2041 if (errno != EAGAIN && errno != EINTR) {
2042 error("write: %s", strerror(errno));
2043 sftp_server_cleanup_exit(1);
2044 }
2045 } else if ((r = sshbuf_consume(oqueue, len)) != 0)
2046 fatal_fr(r, "consume");
2047 }
2048
2049 /*
2050 * Process requests from client if we can fit the results
2051 * into the output buffer, otherwise stop processing input
2052 * and let the output queue drain.
2053 */
2054 r = sshbuf_check_reserve(oqueue, SFTP_MAX_MSG_LENGTH);
2055 if (r == 0)
2056 process();
2057 else if (r != SSH_ERR_NO_BUFFER_SPACE)
2058 fatal_fr(r, "reserve");
2059 }
2060 }
2061