1 /* $OpenBSD: sftp-server.c,v 1.120 2020/10/18 11:32:02 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/stat.h> 20 #include <sys/time.h> 21 #include <sys/mount.h> 22 #include <sys/statvfs.h> 23 24 #include <dirent.h> 25 #include <errno.h> 26 #include <fcntl.h> 27 #include <stdlib.h> 28 #include <stdio.h> 29 #include <string.h> 30 #include <pwd.h> 31 #include <time.h> 32 #include <unistd.h> 33 #include <stdarg.h> 34 35 #include "xmalloc.h" 36 #include "sshbuf.h" 37 #include "ssherr.h" 38 #include "log.h" 39 #include "misc.h" 40 #include "match.h" 41 #include "uidswap.h" 42 43 #include "sftp.h" 44 #include "sftp-common.h" 45 46 char *sftp_realpath(const char *, char *); /* sftp-realpath.c */ 47 48 /* Our verbosity */ 49 static LogLevel log_level = SYSLOG_LEVEL_ERROR; 50 51 /* Our client */ 52 static struct passwd *pw = NULL; 53 static char *client_addr = NULL; 54 55 /* input and output queue */ 56 struct sshbuf *iqueue; 57 struct sshbuf *oqueue; 58 59 /* Version of client */ 60 static u_int version; 61 62 /* SSH2_FXP_INIT received */ 63 static int init_done; 64 65 /* Disable writes */ 66 static int readonly; 67 68 /* Requests that are allowed/denied */ 69 static char *request_allowlist, *request_denylist; 70 71 /* portable attributes, etc. */ 72 typedef struct Stat Stat; 73 74 struct Stat { 75 char *name; 76 char *long_name; 77 Attrib attrib; 78 }; 79 80 /* Packet handlers */ 81 static void process_open(u_int32_t id); 82 static void process_close(u_int32_t id); 83 static void process_read(u_int32_t id); 84 static void process_write(u_int32_t id); 85 static void process_stat(u_int32_t id); 86 static void process_lstat(u_int32_t id); 87 static void process_fstat(u_int32_t id); 88 static void process_setstat(u_int32_t id); 89 static void process_fsetstat(u_int32_t id); 90 static void process_opendir(u_int32_t id); 91 static void process_readdir(u_int32_t id); 92 static void process_remove(u_int32_t id); 93 static void process_mkdir(u_int32_t id); 94 static void process_rmdir(u_int32_t id); 95 static void process_realpath(u_int32_t id); 96 static void process_rename(u_int32_t id); 97 static void process_readlink(u_int32_t id); 98 static void process_symlink(u_int32_t id); 99 static void process_extended_posix_rename(u_int32_t id); 100 static void process_extended_statvfs(u_int32_t id); 101 static void process_extended_fstatvfs(u_int32_t id); 102 static void process_extended_hardlink(u_int32_t id); 103 static void process_extended_fsync(u_int32_t id); 104 static void process_extended_lsetstat(u_int32_t id); 105 static void process_extended(u_int32_t id); 106 107 struct sftp_handler { 108 const char *name; /* user-visible name for fine-grained perms */ 109 const char *ext_name; /* extended request name */ 110 u_int type; /* packet type, for non extended packets */ 111 void (*handler)(u_int32_t); 112 int does_write; /* if nonzero, banned for readonly mode */ 113 }; 114 115 static const struct sftp_handler handlers[] = { 116 /* NB. SSH2_FXP_OPEN does the readonly check in the handler itself */ 117 { "open", NULL, SSH2_FXP_OPEN, process_open, 0 }, 118 { "close", NULL, SSH2_FXP_CLOSE, process_close, 0 }, 119 { "read", NULL, SSH2_FXP_READ, process_read, 0 }, 120 { "write", NULL, SSH2_FXP_WRITE, process_write, 1 }, 121 { "lstat", NULL, SSH2_FXP_LSTAT, process_lstat, 0 }, 122 { "fstat", NULL, SSH2_FXP_FSTAT, process_fstat, 0 }, 123 { "setstat", NULL, SSH2_FXP_SETSTAT, process_setstat, 1 }, 124 { "fsetstat", NULL, SSH2_FXP_FSETSTAT, process_fsetstat, 1 }, 125 { "opendir", NULL, SSH2_FXP_OPENDIR, process_opendir, 0 }, 126 { "readdir", NULL, SSH2_FXP_READDIR, process_readdir, 0 }, 127 { "remove", NULL, SSH2_FXP_REMOVE, process_remove, 1 }, 128 { "mkdir", NULL, SSH2_FXP_MKDIR, process_mkdir, 1 }, 129 { "rmdir", NULL, SSH2_FXP_RMDIR, process_rmdir, 1 }, 130 { "realpath", NULL, SSH2_FXP_REALPATH, process_realpath, 0 }, 131 { "stat", NULL, SSH2_FXP_STAT, process_stat, 0 }, 132 { "rename", NULL, SSH2_FXP_RENAME, process_rename, 1 }, 133 { "readlink", NULL, SSH2_FXP_READLINK, process_readlink, 0 }, 134 { "symlink", NULL, SSH2_FXP_SYMLINK, process_symlink, 1 }, 135 { NULL, NULL, 0, NULL, 0 } 136 }; 137 138 /* SSH2_FXP_EXTENDED submessages */ 139 static const struct sftp_handler extended_handlers[] = { 140 { "posix-rename", "posix-rename@openssh.com", 0, 141 process_extended_posix_rename, 1 }, 142 { "statvfs", "statvfs@openssh.com", 0, process_extended_statvfs, 0 }, 143 { "fstatvfs", "fstatvfs@openssh.com", 0, process_extended_fstatvfs, 0 }, 144 { "hardlink", "hardlink@openssh.com", 0, process_extended_hardlink, 1 }, 145 { "fsync", "fsync@openssh.com", 0, process_extended_fsync, 1 }, 146 { "lsetstat", "lsetstat@openssh.com", 0, process_extended_lsetstat, 1 }, 147 { NULL, NULL, 0, NULL, 0 } 148 }; 149 150 static int 151 request_permitted(const struct sftp_handler *h) 152 { 153 char *result; 154 155 if (readonly && h->does_write) { 156 verbose("Refusing %s request in read-only mode", h->name); 157 return 0; 158 } 159 if (request_denylist != NULL && 160 ((result = match_list(h->name, request_denylist, NULL))) != NULL) { 161 free(result); 162 verbose("Refusing denylisted %s request", h->name); 163 return 0; 164 } 165 if (request_allowlist != NULL && 166 ((result = match_list(h->name, request_allowlist, NULL))) != NULL) { 167 free(result); 168 debug2("Permitting allowlisted %s request", h->name); 169 return 1; 170 } 171 if (request_allowlist != NULL) { 172 verbose("Refusing non-allowlisted %s request", h->name); 173 return 0; 174 } 175 return 1; 176 } 177 178 static int 179 errno_to_portable(int unixerrno) 180 { 181 int ret = 0; 182 183 switch (unixerrno) { 184 case 0: 185 ret = SSH2_FX_OK; 186 break; 187 case ENOENT: 188 case ENOTDIR: 189 case EBADF: 190 case ELOOP: 191 ret = SSH2_FX_NO_SUCH_FILE; 192 break; 193 case EPERM: 194 case EACCES: 195 case EFAULT: 196 ret = SSH2_FX_PERMISSION_DENIED; 197 break; 198 case ENAMETOOLONG: 199 case EINVAL: 200 ret = SSH2_FX_BAD_MESSAGE; 201 break; 202 case ENOSYS: 203 ret = SSH2_FX_OP_UNSUPPORTED; 204 break; 205 default: 206 ret = SSH2_FX_FAILURE; 207 break; 208 } 209 return ret; 210 } 211 212 static int 213 flags_from_portable(int pflags) 214 { 215 int flags = 0; 216 217 if ((pflags & SSH2_FXF_READ) && 218 (pflags & SSH2_FXF_WRITE)) { 219 flags = O_RDWR; 220 } else if (pflags & SSH2_FXF_READ) { 221 flags = O_RDONLY; 222 } else if (pflags & SSH2_FXF_WRITE) { 223 flags = O_WRONLY; 224 } 225 if (pflags & SSH2_FXF_APPEND) 226 flags |= O_APPEND; 227 if (pflags & SSH2_FXF_CREAT) 228 flags |= O_CREAT; 229 if (pflags & SSH2_FXF_TRUNC) 230 flags |= O_TRUNC; 231 if (pflags & SSH2_FXF_EXCL) 232 flags |= O_EXCL; 233 return flags; 234 } 235 236 static const char * 237 string_from_portable(int pflags) 238 { 239 static char ret[128]; 240 241 *ret = '\0'; 242 243 #define PAPPEND(str) { \ 244 if (*ret != '\0') \ 245 strlcat(ret, ",", sizeof(ret)); \ 246 strlcat(ret, str, sizeof(ret)); \ 247 } 248 249 if (pflags & SSH2_FXF_READ) 250 PAPPEND("READ") 251 if (pflags & SSH2_FXF_WRITE) 252 PAPPEND("WRITE") 253 if (pflags & SSH2_FXF_APPEND) 254 PAPPEND("APPEND") 255 if (pflags & SSH2_FXF_CREAT) 256 PAPPEND("CREATE") 257 if (pflags & SSH2_FXF_TRUNC) 258 PAPPEND("TRUNCATE") 259 if (pflags & SSH2_FXF_EXCL) 260 PAPPEND("EXCL") 261 262 return ret; 263 } 264 265 /* handle handles */ 266 267 typedef struct Handle Handle; 268 struct Handle { 269 int use; 270 DIR *dirp; 271 int fd; 272 int flags; 273 char *name; 274 u_int64_t bytes_read, bytes_write; 275 int next_unused; 276 }; 277 278 enum { 279 HANDLE_UNUSED, 280 HANDLE_DIR, 281 HANDLE_FILE 282 }; 283 284 static Handle *handles = NULL; 285 static u_int num_handles = 0; 286 static int first_unused_handle = -1; 287 288 static void handle_unused(int i) 289 { 290 handles[i].use = HANDLE_UNUSED; 291 handles[i].next_unused = first_unused_handle; 292 first_unused_handle = i; 293 } 294 295 static int 296 handle_new(int use, const char *name, int fd, int flags, DIR *dirp) 297 { 298 int i; 299 300 if (first_unused_handle == -1) { 301 if (num_handles + 1 <= num_handles) 302 return -1; 303 num_handles++; 304 handles = xreallocarray(handles, num_handles, sizeof(Handle)); 305 handle_unused(num_handles - 1); 306 } 307 308 i = first_unused_handle; 309 first_unused_handle = handles[i].next_unused; 310 311 handles[i].use = use; 312 handles[i].dirp = dirp; 313 handles[i].fd = fd; 314 handles[i].flags = flags; 315 handles[i].name = xstrdup(name); 316 handles[i].bytes_read = handles[i].bytes_write = 0; 317 318 return i; 319 } 320 321 static int 322 handle_is_ok(int i, int type) 323 { 324 return i >= 0 && (u_int)i < num_handles && handles[i].use == type; 325 } 326 327 static int 328 handle_to_string(int handle, u_char **stringp, int *hlenp) 329 { 330 if (stringp == NULL || hlenp == NULL) 331 return -1; 332 *stringp = xmalloc(sizeof(int32_t)); 333 put_u32(*stringp, handle); 334 *hlenp = sizeof(int32_t); 335 return 0; 336 } 337 338 static int 339 handle_from_string(const u_char *handle, u_int hlen) 340 { 341 int val; 342 343 if (hlen != sizeof(int32_t)) 344 return -1; 345 val = get_u32(handle); 346 if (handle_is_ok(val, HANDLE_FILE) || 347 handle_is_ok(val, HANDLE_DIR)) 348 return val; 349 return -1; 350 } 351 352 static char * 353 handle_to_name(int handle) 354 { 355 if (handle_is_ok(handle, HANDLE_DIR)|| 356 handle_is_ok(handle, HANDLE_FILE)) 357 return handles[handle].name; 358 return NULL; 359 } 360 361 static DIR * 362 handle_to_dir(int handle) 363 { 364 if (handle_is_ok(handle, HANDLE_DIR)) 365 return handles[handle].dirp; 366 return NULL; 367 } 368 369 static int 370 handle_to_fd(int handle) 371 { 372 if (handle_is_ok(handle, HANDLE_FILE)) 373 return handles[handle].fd; 374 return -1; 375 } 376 377 static int 378 handle_to_flags(int handle) 379 { 380 if (handle_is_ok(handle, HANDLE_FILE)) 381 return handles[handle].flags; 382 return 0; 383 } 384 385 static void 386 handle_update_read(int handle, ssize_t bytes) 387 { 388 if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0) 389 handles[handle].bytes_read += bytes; 390 } 391 392 static void 393 handle_update_write(int handle, ssize_t bytes) 394 { 395 if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0) 396 handles[handle].bytes_write += bytes; 397 } 398 399 static u_int64_t 400 handle_bytes_read(int handle) 401 { 402 if (handle_is_ok(handle, HANDLE_FILE)) 403 return (handles[handle].bytes_read); 404 return 0; 405 } 406 407 static u_int64_t 408 handle_bytes_write(int handle) 409 { 410 if (handle_is_ok(handle, HANDLE_FILE)) 411 return (handles[handle].bytes_write); 412 return 0; 413 } 414 415 static int 416 handle_close(int handle) 417 { 418 int ret = -1; 419 420 if (handle_is_ok(handle, HANDLE_FILE)) { 421 ret = close(handles[handle].fd); 422 free(handles[handle].name); 423 handle_unused(handle); 424 } else if (handle_is_ok(handle, HANDLE_DIR)) { 425 ret = closedir(handles[handle].dirp); 426 free(handles[handle].name); 427 handle_unused(handle); 428 } else { 429 errno = ENOENT; 430 } 431 return ret; 432 } 433 434 static void 435 handle_log_close(int handle, char *emsg) 436 { 437 if (handle_is_ok(handle, HANDLE_FILE)) { 438 logit("%s%sclose \"%s\" bytes read %llu written %llu", 439 emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ", 440 handle_to_name(handle), 441 (unsigned long long)handle_bytes_read(handle), 442 (unsigned long long)handle_bytes_write(handle)); 443 } else { 444 logit("%s%sclosedir \"%s\"", 445 emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ", 446 handle_to_name(handle)); 447 } 448 } 449 450 static void 451 handle_log_exit(void) 452 { 453 u_int i; 454 455 for (i = 0; i < num_handles; i++) 456 if (handles[i].use != HANDLE_UNUSED) 457 handle_log_close(i, "forced"); 458 } 459 460 static int 461 get_handle(struct sshbuf *queue, int *hp) 462 { 463 u_char *handle; 464 int r; 465 size_t hlen; 466 467 *hp = -1; 468 if ((r = sshbuf_get_string(queue, &handle, &hlen)) != 0) 469 return r; 470 if (hlen < 256) 471 *hp = handle_from_string(handle, hlen); 472 free(handle); 473 return 0; 474 } 475 476 /* send replies */ 477 478 static void 479 send_msg(struct sshbuf *m) 480 { 481 int r; 482 483 if ((r = sshbuf_put_stringb(oqueue, m)) != 0) 484 fatal_fr(r, "enqueue"); 485 sshbuf_reset(m); 486 } 487 488 static const char * 489 status_to_message(u_int32_t status) 490 { 491 const char *status_messages[] = { 492 "Success", /* SSH_FX_OK */ 493 "End of file", /* SSH_FX_EOF */ 494 "No such file", /* SSH_FX_NO_SUCH_FILE */ 495 "Permission denied", /* SSH_FX_PERMISSION_DENIED */ 496 "Failure", /* SSH_FX_FAILURE */ 497 "Bad message", /* SSH_FX_BAD_MESSAGE */ 498 "No connection", /* SSH_FX_NO_CONNECTION */ 499 "Connection lost", /* SSH_FX_CONNECTION_LOST */ 500 "Operation unsupported", /* SSH_FX_OP_UNSUPPORTED */ 501 "Unknown error" /* Others */ 502 }; 503 return (status_messages[MINIMUM(status,SSH2_FX_MAX)]); 504 } 505 506 static void 507 send_status(u_int32_t id, u_int32_t status) 508 { 509 struct sshbuf *msg; 510 int r; 511 512 debug3("request %u: sent status %u", id, status); 513 if (log_level > SYSLOG_LEVEL_VERBOSE || 514 (status != SSH2_FX_OK && status != SSH2_FX_EOF)) 515 logit("sent status %s", status_to_message(status)); 516 if ((msg = sshbuf_new()) == NULL) 517 fatal_f("sshbuf_new failed"); 518 if ((r = sshbuf_put_u8(msg, SSH2_FXP_STATUS)) != 0 || 519 (r = sshbuf_put_u32(msg, id)) != 0 || 520 (r = sshbuf_put_u32(msg, status)) != 0) 521 fatal_fr(r, "compose"); 522 if (version >= 3) { 523 if ((r = sshbuf_put_cstring(msg, 524 status_to_message(status))) != 0 || 525 (r = sshbuf_put_cstring(msg, "")) != 0) 526 fatal_fr(r, "compose message"); 527 } 528 send_msg(msg); 529 sshbuf_free(msg); 530 } 531 static void 532 send_data_or_handle(char type, u_int32_t id, const u_char *data, int dlen) 533 { 534 struct sshbuf *msg; 535 int r; 536 537 if ((msg = sshbuf_new()) == NULL) 538 fatal_f("sshbuf_new failed"); 539 if ((r = sshbuf_put_u8(msg, type)) != 0 || 540 (r = sshbuf_put_u32(msg, id)) != 0 || 541 (r = sshbuf_put_string(msg, data, dlen)) != 0) 542 fatal_fr(r, "compose"); 543 send_msg(msg); 544 sshbuf_free(msg); 545 } 546 547 static void 548 send_data(u_int32_t id, const u_char *data, int dlen) 549 { 550 debug("request %u: sent data len %d", id, dlen); 551 send_data_or_handle(SSH2_FXP_DATA, id, data, dlen); 552 } 553 554 static void 555 send_handle(u_int32_t id, int handle) 556 { 557 u_char *string; 558 int hlen; 559 560 handle_to_string(handle, &string, &hlen); 561 debug("request %u: sent handle handle %d", id, handle); 562 send_data_or_handle(SSH2_FXP_HANDLE, id, string, hlen); 563 free(string); 564 } 565 566 static void 567 send_names(u_int32_t id, int count, const Stat *stats) 568 { 569 struct sshbuf *msg; 570 int i, r; 571 572 if ((msg = sshbuf_new()) == NULL) 573 fatal_f("sshbuf_new failed"); 574 if ((r = sshbuf_put_u8(msg, SSH2_FXP_NAME)) != 0 || 575 (r = sshbuf_put_u32(msg, id)) != 0 || 576 (r = sshbuf_put_u32(msg, count)) != 0) 577 fatal_fr(r, "compose"); 578 debug("request %u: sent names count %d", id, count); 579 for (i = 0; i < count; i++) { 580 if ((r = sshbuf_put_cstring(msg, stats[i].name)) != 0 || 581 (r = sshbuf_put_cstring(msg, stats[i].long_name)) != 0 || 582 (r = encode_attrib(msg, &stats[i].attrib)) != 0) 583 fatal_fr(r, "compose filenames/attrib"); 584 } 585 send_msg(msg); 586 sshbuf_free(msg); 587 } 588 589 static void 590 send_attrib(u_int32_t id, const Attrib *a) 591 { 592 struct sshbuf *msg; 593 int r; 594 595 debug("request %u: sent attrib have 0x%x", id, a->flags); 596 if ((msg = sshbuf_new()) == NULL) 597 fatal_f("sshbuf_new failed"); 598 if ((r = sshbuf_put_u8(msg, SSH2_FXP_ATTRS)) != 0 || 599 (r = sshbuf_put_u32(msg, id)) != 0 || 600 (r = encode_attrib(msg, a)) != 0) 601 fatal_fr(r, "compose"); 602 send_msg(msg); 603 sshbuf_free(msg); 604 } 605 606 static void 607 send_statvfs(u_int32_t id, struct statvfs *st) 608 { 609 struct sshbuf *msg; 610 u_int64_t flag; 611 int r; 612 613 flag = (st->f_flag & ST_RDONLY) ? SSH2_FXE_STATVFS_ST_RDONLY : 0; 614 flag |= (st->f_flag & ST_NOSUID) ? SSH2_FXE_STATVFS_ST_NOSUID : 0; 615 616 if ((msg = sshbuf_new()) == NULL) 617 fatal_f("sshbuf_new failed"); 618 if ((r = sshbuf_put_u8(msg, SSH2_FXP_EXTENDED_REPLY)) != 0 || 619 (r = sshbuf_put_u32(msg, id)) != 0 || 620 (r = sshbuf_put_u64(msg, st->f_bsize)) != 0 || 621 (r = sshbuf_put_u64(msg, st->f_frsize)) != 0 || 622 (r = sshbuf_put_u64(msg, st->f_blocks)) != 0 || 623 (r = sshbuf_put_u64(msg, st->f_bfree)) != 0 || 624 (r = sshbuf_put_u64(msg, st->f_bavail)) != 0 || 625 (r = sshbuf_put_u64(msg, st->f_files)) != 0 || 626 (r = sshbuf_put_u64(msg, st->f_ffree)) != 0 || 627 (r = sshbuf_put_u64(msg, st->f_favail)) != 0 || 628 (r = sshbuf_put_u64(msg, st->f_fsid)) != 0 || 629 (r = sshbuf_put_u64(msg, flag)) != 0 || 630 (r = sshbuf_put_u64(msg, st->f_namemax)) != 0) 631 fatal_fr(r, "compose"); 632 send_msg(msg); 633 sshbuf_free(msg); 634 } 635 636 /* parse incoming */ 637 638 static void 639 process_init(void) 640 { 641 struct sshbuf *msg; 642 int r; 643 644 if ((r = sshbuf_get_u32(iqueue, &version)) != 0) 645 fatal_fr(r, "parse"); 646 verbose("received client version %u", version); 647 if ((msg = sshbuf_new()) == NULL) 648 fatal_f("sshbuf_new failed"); 649 if ((r = sshbuf_put_u8(msg, SSH2_FXP_VERSION)) != 0 || 650 (r = sshbuf_put_u32(msg, SSH2_FILEXFER_VERSION)) != 0 || 651 /* POSIX rename extension */ 652 (r = sshbuf_put_cstring(msg, "posix-rename@openssh.com")) != 0 || 653 (r = sshbuf_put_cstring(msg, "1")) != 0 || /* version */ 654 /* statvfs extension */ 655 (r = sshbuf_put_cstring(msg, "statvfs@openssh.com")) != 0 || 656 (r = sshbuf_put_cstring(msg, "2")) != 0 || /* version */ 657 /* fstatvfs extension */ 658 (r = sshbuf_put_cstring(msg, "fstatvfs@openssh.com")) != 0 || 659 (r = sshbuf_put_cstring(msg, "2")) != 0 || /* version */ 660 /* hardlink extension */ 661 (r = sshbuf_put_cstring(msg, "hardlink@openssh.com")) != 0 || 662 (r = sshbuf_put_cstring(msg, "1")) != 0 || /* version */ 663 /* fsync extension */ 664 (r = sshbuf_put_cstring(msg, "fsync@openssh.com")) != 0 || 665 (r = sshbuf_put_cstring(msg, "1")) != 0 || /* version */ 666 (r = sshbuf_put_cstring(msg, "lsetstat@openssh.com")) != 0 || 667 (r = sshbuf_put_cstring(msg, "1")) != 0) /* version */ 668 fatal_fr(r, "compose"); 669 send_msg(msg); 670 sshbuf_free(msg); 671 } 672 673 static void 674 process_open(u_int32_t id) 675 { 676 u_int32_t pflags; 677 Attrib a; 678 char *name; 679 int r, handle, fd, flags, mode, status = SSH2_FX_FAILURE; 680 681 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 || 682 (r = sshbuf_get_u32(iqueue, &pflags)) != 0 || /* portable flags */ 683 (r = decode_attrib(iqueue, &a)) != 0) 684 fatal_fr(r, "parse"); 685 686 debug3("request %u: open flags %d", id, pflags); 687 flags = flags_from_portable(pflags); 688 mode = (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? a.perm : 0666; 689 logit("open \"%s\" flags %s mode 0%o", 690 name, string_from_portable(pflags), mode); 691 if (readonly && 692 ((flags & O_ACCMODE) != O_RDONLY || 693 (flags & (O_CREAT|O_TRUNC)) != 0)) { 694 verbose("Refusing open request in read-only mode"); 695 status = SSH2_FX_PERMISSION_DENIED; 696 } else { 697 fd = open(name, flags, mode); 698 if (fd == -1) { 699 status = errno_to_portable(errno); 700 } else { 701 handle = handle_new(HANDLE_FILE, name, fd, flags, NULL); 702 if (handle < 0) { 703 close(fd); 704 } else { 705 send_handle(id, handle); 706 status = SSH2_FX_OK; 707 } 708 } 709 } 710 if (status != SSH2_FX_OK) 711 send_status(id, status); 712 free(name); 713 } 714 715 static void 716 process_close(u_int32_t id) 717 { 718 int r, handle, ret, status = SSH2_FX_FAILURE; 719 720 if ((r = get_handle(iqueue, &handle)) != 0) 721 fatal_fr(r, "parse"); 722 723 debug3("request %u: close handle %u", id, handle); 724 handle_log_close(handle, NULL); 725 ret = handle_close(handle); 726 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 727 send_status(id, status); 728 } 729 730 static void 731 process_read(u_int32_t id) 732 { 733 u_char buf[64*1024]; 734 u_int32_t len; 735 int r, handle, fd, ret, status = SSH2_FX_FAILURE; 736 u_int64_t off; 737 738 if ((r = get_handle(iqueue, &handle)) != 0 || 739 (r = sshbuf_get_u64(iqueue, &off)) != 0 || 740 (r = sshbuf_get_u32(iqueue, &len)) != 0) 741 fatal_fr(r, "parse"); 742 743 debug("request %u: read \"%s\" (handle %d) off %llu len %d", 744 id, handle_to_name(handle), handle, (unsigned long long)off, len); 745 if (len > sizeof buf) { 746 len = sizeof buf; 747 debug2("read change len %d", len); 748 } 749 fd = handle_to_fd(handle); 750 if (fd >= 0) { 751 if (lseek(fd, off, SEEK_SET) == -1) { 752 error("process_read: seek failed"); 753 status = errno_to_portable(errno); 754 } else { 755 ret = read(fd, buf, len); 756 if (ret == -1) { 757 status = errno_to_portable(errno); 758 } else if (ret == 0) { 759 status = SSH2_FX_EOF; 760 } else { 761 send_data(id, buf, ret); 762 status = SSH2_FX_OK; 763 handle_update_read(handle, ret); 764 } 765 } 766 } 767 if (status != SSH2_FX_OK) 768 send_status(id, status); 769 } 770 771 static void 772 process_write(u_int32_t id) 773 { 774 u_int64_t off; 775 size_t len; 776 int r, handle, fd, ret, status; 777 u_char *data; 778 779 if ((r = get_handle(iqueue, &handle)) != 0 || 780 (r = sshbuf_get_u64(iqueue, &off)) != 0 || 781 (r = sshbuf_get_string(iqueue, &data, &len)) != 0) 782 fatal_fr(r, "parse"); 783 784 debug("request %u: write \"%s\" (handle %d) off %llu len %zu", 785 id, handle_to_name(handle), handle, (unsigned long long)off, len); 786 fd = handle_to_fd(handle); 787 788 if (fd < 0) 789 status = SSH2_FX_FAILURE; 790 else { 791 if (!(handle_to_flags(handle) & O_APPEND) && 792 lseek(fd, off, SEEK_SET) == -1) { 793 status = errno_to_portable(errno); 794 error_f("seek failed"); 795 } else { 796 /* XXX ATOMICIO ? */ 797 ret = write(fd, data, len); 798 if (ret == -1) { 799 error_f("write: %s", strerror(errno)); 800 status = errno_to_portable(errno); 801 } else if ((size_t)ret == len) { 802 status = SSH2_FX_OK; 803 handle_update_write(handle, ret); 804 } else { 805 debug2_f("nothing at all written"); 806 status = SSH2_FX_FAILURE; 807 } 808 } 809 } 810 send_status(id, status); 811 free(data); 812 } 813 814 static void 815 process_do_stat(u_int32_t id, int do_lstat) 816 { 817 Attrib a; 818 struct stat st; 819 char *name; 820 int r, status = SSH2_FX_FAILURE; 821 822 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0) 823 fatal_fr(r, "parse"); 824 825 debug3("request %u: %sstat", id, do_lstat ? "l" : ""); 826 verbose("%sstat name \"%s\"", do_lstat ? "l" : "", name); 827 r = do_lstat ? lstat(name, &st) : stat(name, &st); 828 if (r == -1) { 829 status = errno_to_portable(errno); 830 } else { 831 stat_to_attrib(&st, &a); 832 send_attrib(id, &a); 833 status = SSH2_FX_OK; 834 } 835 if (status != SSH2_FX_OK) 836 send_status(id, status); 837 free(name); 838 } 839 840 static void 841 process_stat(u_int32_t id) 842 { 843 process_do_stat(id, 0); 844 } 845 846 static void 847 process_lstat(u_int32_t id) 848 { 849 process_do_stat(id, 1); 850 } 851 852 static void 853 process_fstat(u_int32_t id) 854 { 855 Attrib a; 856 struct stat st; 857 int fd, r, handle, status = SSH2_FX_FAILURE; 858 859 if ((r = get_handle(iqueue, &handle)) != 0) 860 fatal_fr(r, "parse"); 861 debug("request %u: fstat \"%s\" (handle %u)", 862 id, handle_to_name(handle), handle); 863 fd = handle_to_fd(handle); 864 if (fd >= 0) { 865 r = fstat(fd, &st); 866 if (r == -1) { 867 status = errno_to_portable(errno); 868 } else { 869 stat_to_attrib(&st, &a); 870 send_attrib(id, &a); 871 status = SSH2_FX_OK; 872 } 873 } 874 if (status != SSH2_FX_OK) 875 send_status(id, status); 876 } 877 878 static struct timeval * 879 attrib_to_tv(const Attrib *a) 880 { 881 static struct timeval tv[2]; 882 883 tv[0].tv_sec = a->atime; 884 tv[0].tv_usec = 0; 885 tv[1].tv_sec = a->mtime; 886 tv[1].tv_usec = 0; 887 return tv; 888 } 889 890 static struct timespec * 891 attrib_to_ts(const Attrib *a) 892 { 893 static struct timespec ts[2]; 894 895 ts[0].tv_sec = a->atime; 896 ts[0].tv_nsec = 0; 897 ts[1].tv_sec = a->mtime; 898 ts[1].tv_nsec = 0; 899 return ts; 900 } 901 902 static void 903 process_setstat(u_int32_t id) 904 { 905 Attrib a; 906 char *name; 907 int r, status = SSH2_FX_OK; 908 909 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 || 910 (r = decode_attrib(iqueue, &a)) != 0) 911 fatal_fr(r, "parse"); 912 913 debug("request %u: setstat name \"%s\"", id, name); 914 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) { 915 logit("set \"%s\" size %llu", 916 name, (unsigned long long)a.size); 917 r = truncate(name, a.size); 918 if (r == -1) 919 status = errno_to_portable(errno); 920 } 921 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) { 922 logit("set \"%s\" mode %04o", name, a.perm); 923 r = chmod(name, a.perm & 07777); 924 if (r == -1) 925 status = errno_to_portable(errno); 926 } 927 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) { 928 char buf[64]; 929 time_t t = a.mtime; 930 931 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S", 932 localtime(&t)); 933 logit("set \"%s\" modtime %s", name, buf); 934 r = utimes(name, attrib_to_tv(&a)); 935 if (r == -1) 936 status = errno_to_portable(errno); 937 } 938 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) { 939 logit("set \"%s\" owner %lu group %lu", name, 940 (u_long)a.uid, (u_long)a.gid); 941 r = chown(name, a.uid, a.gid); 942 if (r == -1) 943 status = errno_to_portable(errno); 944 } 945 send_status(id, status); 946 free(name); 947 } 948 949 static void 950 process_fsetstat(u_int32_t id) 951 { 952 Attrib a; 953 int handle, fd, r; 954 int status = SSH2_FX_OK; 955 956 if ((r = get_handle(iqueue, &handle)) != 0 || 957 (r = decode_attrib(iqueue, &a)) != 0) 958 fatal_fr(r, "parse"); 959 960 debug("request %u: fsetstat handle %d", id, handle); 961 fd = handle_to_fd(handle); 962 if (fd < 0) 963 status = SSH2_FX_FAILURE; 964 else { 965 char *name = handle_to_name(handle); 966 967 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) { 968 logit("set \"%s\" size %llu", 969 name, (unsigned long long)a.size); 970 r = ftruncate(fd, a.size); 971 if (r == -1) 972 status = errno_to_portable(errno); 973 } 974 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) { 975 logit("set \"%s\" mode %04o", name, a.perm); 976 r = fchmod(fd, a.perm & 07777); 977 if (r == -1) 978 status = errno_to_portable(errno); 979 } 980 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) { 981 char buf[64]; 982 time_t t = a.mtime; 983 984 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S", 985 localtime(&t)); 986 logit("set \"%s\" modtime %s", name, buf); 987 r = futimes(fd, attrib_to_tv(&a)); 988 if (r == -1) 989 status = errno_to_portable(errno); 990 } 991 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) { 992 logit("set \"%s\" owner %lu group %lu", name, 993 (u_long)a.uid, (u_long)a.gid); 994 r = fchown(fd, a.uid, a.gid); 995 if (r == -1) 996 status = errno_to_portable(errno); 997 } 998 } 999 send_status(id, status); 1000 } 1001 1002 static void 1003 process_opendir(u_int32_t id) 1004 { 1005 DIR *dirp = NULL; 1006 char *path; 1007 int r, handle, status = SSH2_FX_FAILURE; 1008 1009 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0) 1010 fatal_fr(r, "parse"); 1011 1012 debug3("request %u: opendir", id); 1013 logit("opendir \"%s\"", path); 1014 dirp = opendir(path); 1015 if (dirp == NULL) { 1016 status = errno_to_portable(errno); 1017 } else { 1018 handle = handle_new(HANDLE_DIR, path, 0, 0, dirp); 1019 if (handle < 0) { 1020 closedir(dirp); 1021 } else { 1022 send_handle(id, handle); 1023 status = SSH2_FX_OK; 1024 } 1025 1026 } 1027 if (status != SSH2_FX_OK) 1028 send_status(id, status); 1029 free(path); 1030 } 1031 1032 static void 1033 process_readdir(u_int32_t id) 1034 { 1035 DIR *dirp; 1036 struct dirent *dp; 1037 char *path; 1038 int r, handle; 1039 1040 if ((r = get_handle(iqueue, &handle)) != 0) 1041 fatal_fr(r, "parse"); 1042 1043 debug("request %u: readdir \"%s\" (handle %d)", id, 1044 handle_to_name(handle), handle); 1045 dirp = handle_to_dir(handle); 1046 path = handle_to_name(handle); 1047 if (dirp == NULL || path == NULL) { 1048 send_status(id, SSH2_FX_FAILURE); 1049 } else { 1050 struct stat st; 1051 char pathname[PATH_MAX]; 1052 Stat *stats; 1053 int nstats = 10, count = 0, i; 1054 1055 stats = xcalloc(nstats, sizeof(Stat)); 1056 while ((dp = readdir(dirp)) != NULL) { 1057 if (count >= nstats) { 1058 nstats *= 2; 1059 stats = xreallocarray(stats, nstats, sizeof(Stat)); 1060 } 1061 /* XXX OVERFLOW ? */ 1062 snprintf(pathname, sizeof pathname, "%s%s%s", path, 1063 strcmp(path, "/") ? "/" : "", dp->d_name); 1064 if (lstat(pathname, &st) == -1) 1065 continue; 1066 stat_to_attrib(&st, &(stats[count].attrib)); 1067 stats[count].name = xstrdup(dp->d_name); 1068 stats[count].long_name = ls_file(dp->d_name, &st, 0, 0); 1069 count++; 1070 /* send up to 100 entries in one message */ 1071 /* XXX check packet size instead */ 1072 if (count == 100) 1073 break; 1074 } 1075 if (count > 0) { 1076 send_names(id, count, stats); 1077 for (i = 0; i < count; i++) { 1078 free(stats[i].name); 1079 free(stats[i].long_name); 1080 } 1081 } else { 1082 send_status(id, SSH2_FX_EOF); 1083 } 1084 free(stats); 1085 } 1086 } 1087 1088 static void 1089 process_remove(u_int32_t id) 1090 { 1091 char *name; 1092 int r, status = SSH2_FX_FAILURE; 1093 1094 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0) 1095 fatal_fr(r, "parse"); 1096 1097 debug3("request %u: remove", id); 1098 logit("remove name \"%s\"", name); 1099 r = unlink(name); 1100 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1101 send_status(id, status); 1102 free(name); 1103 } 1104 1105 static void 1106 process_mkdir(u_int32_t id) 1107 { 1108 Attrib a; 1109 char *name; 1110 int r, mode, status = SSH2_FX_FAILURE; 1111 1112 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 || 1113 (r = decode_attrib(iqueue, &a)) != 0) 1114 fatal_fr(r, "parse"); 1115 1116 mode = (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? 1117 a.perm & 07777 : 0777; 1118 debug3("request %u: mkdir", id); 1119 logit("mkdir name \"%s\" mode 0%o", name, mode); 1120 r = mkdir(name, mode); 1121 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1122 send_status(id, status); 1123 free(name); 1124 } 1125 1126 static void 1127 process_rmdir(u_int32_t id) 1128 { 1129 char *name; 1130 int r, status; 1131 1132 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0) 1133 fatal_fr(r, "parse"); 1134 1135 debug3("request %u: rmdir", id); 1136 logit("rmdir name \"%s\"", name); 1137 r = rmdir(name); 1138 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1139 send_status(id, status); 1140 free(name); 1141 } 1142 1143 static void 1144 process_realpath(u_int32_t id) 1145 { 1146 char resolvedname[PATH_MAX]; 1147 char *path; 1148 int r; 1149 1150 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0) 1151 fatal_fr(r, "parse"); 1152 1153 if (path[0] == '\0') { 1154 free(path); 1155 path = xstrdup("."); 1156 } 1157 debug3("request %u: realpath", id); 1158 verbose("realpath \"%s\"", path); 1159 if (sftp_realpath(path, resolvedname) == NULL) { 1160 send_status(id, errno_to_portable(errno)); 1161 } else { 1162 Stat s; 1163 attrib_clear(&s.attrib); 1164 s.name = s.long_name = resolvedname; 1165 send_names(id, 1, &s); 1166 } 1167 free(path); 1168 } 1169 1170 static void 1171 process_rename(u_int32_t id) 1172 { 1173 char *oldpath, *newpath; 1174 int r, status; 1175 struct stat sb; 1176 1177 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 || 1178 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0) 1179 fatal_fr(r, "parse"); 1180 1181 debug3("request %u: rename", id); 1182 logit("rename old \"%s\" new \"%s\"", oldpath, newpath); 1183 status = SSH2_FX_FAILURE; 1184 if (lstat(oldpath, &sb) == -1) 1185 status = errno_to_portable(errno); 1186 else if (S_ISREG(sb.st_mode)) { 1187 /* Race-free rename of regular files */ 1188 if (link(oldpath, newpath) == -1) { 1189 if (errno == EOPNOTSUPP) { 1190 struct stat st; 1191 1192 /* 1193 * fs doesn't support links, so fall back to 1194 * stat+rename. This is racy. 1195 */ 1196 if (stat(newpath, &st) == -1) { 1197 if (rename(oldpath, newpath) == -1) 1198 status = 1199 errno_to_portable(errno); 1200 else 1201 status = SSH2_FX_OK; 1202 } 1203 } else { 1204 status = errno_to_portable(errno); 1205 } 1206 } else if (unlink(oldpath) == -1) { 1207 status = errno_to_portable(errno); 1208 /* clean spare link */ 1209 unlink(newpath); 1210 } else 1211 status = SSH2_FX_OK; 1212 } else if (stat(newpath, &sb) == -1) { 1213 if (rename(oldpath, newpath) == -1) 1214 status = errno_to_portable(errno); 1215 else 1216 status = SSH2_FX_OK; 1217 } 1218 send_status(id, status); 1219 free(oldpath); 1220 free(newpath); 1221 } 1222 1223 static void 1224 process_readlink(u_int32_t id) 1225 { 1226 int r, len; 1227 char buf[PATH_MAX]; 1228 char *path; 1229 1230 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0) 1231 fatal_fr(r, "parse"); 1232 1233 debug3("request %u: readlink", id); 1234 verbose("readlink \"%s\"", path); 1235 if ((len = readlink(path, buf, sizeof(buf) - 1)) == -1) 1236 send_status(id, errno_to_portable(errno)); 1237 else { 1238 Stat s; 1239 1240 buf[len] = '\0'; 1241 attrib_clear(&s.attrib); 1242 s.name = s.long_name = buf; 1243 send_names(id, 1, &s); 1244 } 1245 free(path); 1246 } 1247 1248 static void 1249 process_symlink(u_int32_t id) 1250 { 1251 char *oldpath, *newpath; 1252 int r, status; 1253 1254 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 || 1255 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0) 1256 fatal_fr(r, "parse"); 1257 1258 debug3("request %u: symlink", id); 1259 logit("symlink old \"%s\" new \"%s\"", oldpath, newpath); 1260 /* this will fail if 'newpath' exists */ 1261 r = symlink(oldpath, newpath); 1262 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1263 send_status(id, status); 1264 free(oldpath); 1265 free(newpath); 1266 } 1267 1268 static void 1269 process_extended_posix_rename(u_int32_t id) 1270 { 1271 char *oldpath, *newpath; 1272 int r, status; 1273 1274 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 || 1275 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0) 1276 fatal_fr(r, "parse"); 1277 1278 debug3("request %u: posix-rename", id); 1279 logit("posix-rename old \"%s\" new \"%s\"", oldpath, newpath); 1280 r = rename(oldpath, newpath); 1281 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1282 send_status(id, status); 1283 free(oldpath); 1284 free(newpath); 1285 } 1286 1287 static void 1288 process_extended_statvfs(u_int32_t id) 1289 { 1290 char *path; 1291 struct statvfs st; 1292 int r; 1293 1294 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0) 1295 fatal_fr(r, "parse"); 1296 debug3("request %u: statvfs", id); 1297 logit("statvfs \"%s\"", path); 1298 1299 if (statvfs(path, &st) != 0) 1300 send_status(id, errno_to_portable(errno)); 1301 else 1302 send_statvfs(id, &st); 1303 free(path); 1304 } 1305 1306 static void 1307 process_extended_fstatvfs(u_int32_t id) 1308 { 1309 int r, handle, fd; 1310 struct statvfs st; 1311 1312 if ((r = get_handle(iqueue, &handle)) != 0) 1313 fatal_fr(r, "parse"); 1314 debug("request %u: fstatvfs \"%s\" (handle %u)", 1315 id, handle_to_name(handle), handle); 1316 if ((fd = handle_to_fd(handle)) < 0) { 1317 send_status(id, SSH2_FX_FAILURE); 1318 return; 1319 } 1320 if (fstatvfs(fd, &st) != 0) 1321 send_status(id, errno_to_portable(errno)); 1322 else 1323 send_statvfs(id, &st); 1324 } 1325 1326 static void 1327 process_extended_hardlink(u_int32_t id) 1328 { 1329 char *oldpath, *newpath; 1330 int r, status; 1331 1332 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 || 1333 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0) 1334 fatal_fr(r, "parse"); 1335 1336 debug3("request %u: hardlink", id); 1337 logit("hardlink old \"%s\" new \"%s\"", oldpath, newpath); 1338 r = link(oldpath, newpath); 1339 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1340 send_status(id, status); 1341 free(oldpath); 1342 free(newpath); 1343 } 1344 1345 static void 1346 process_extended_fsync(u_int32_t id) 1347 { 1348 int handle, fd, r, status = SSH2_FX_OP_UNSUPPORTED; 1349 1350 if ((r = get_handle(iqueue, &handle)) != 0) 1351 fatal_fr(r, "parse"); 1352 debug3("request %u: fsync (handle %u)", id, handle); 1353 verbose("fsync \"%s\"", handle_to_name(handle)); 1354 if ((fd = handle_to_fd(handle)) < 0) 1355 status = SSH2_FX_NO_SUCH_FILE; 1356 else if (handle_is_ok(handle, HANDLE_FILE)) { 1357 r = fsync(fd); 1358 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1359 } 1360 send_status(id, status); 1361 } 1362 1363 static void 1364 process_extended_lsetstat(u_int32_t id) 1365 { 1366 Attrib a; 1367 char *name; 1368 int r, status = SSH2_FX_OK; 1369 1370 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 || 1371 (r = decode_attrib(iqueue, &a)) != 0) 1372 fatal_fr(r, "parse"); 1373 1374 debug("request %u: lsetstat name \"%s\"", id, name); 1375 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) { 1376 /* nonsensical for links */ 1377 status = SSH2_FX_BAD_MESSAGE; 1378 goto out; 1379 } 1380 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) { 1381 logit("set \"%s\" mode %04o", name, a.perm); 1382 r = fchmodat(AT_FDCWD, name, 1383 a.perm & 07777, AT_SYMLINK_NOFOLLOW); 1384 if (r == -1) 1385 status = errno_to_portable(errno); 1386 } 1387 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) { 1388 char buf[64]; 1389 time_t t = a.mtime; 1390 1391 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S", 1392 localtime(&t)); 1393 logit("set \"%s\" modtime %s", name, buf); 1394 r = utimensat(AT_FDCWD, name, 1395 attrib_to_ts(&a), AT_SYMLINK_NOFOLLOW); 1396 if (r == -1) 1397 status = errno_to_portable(errno); 1398 } 1399 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) { 1400 logit("set \"%s\" owner %lu group %lu", name, 1401 (u_long)a.uid, (u_long)a.gid); 1402 r = fchownat(AT_FDCWD, name, a.uid, a.gid, 1403 AT_SYMLINK_NOFOLLOW); 1404 if (r == -1) 1405 status = errno_to_portable(errno); 1406 } 1407 out: 1408 send_status(id, status); 1409 free(name); 1410 } 1411 1412 static void 1413 process_extended(u_int32_t id) 1414 { 1415 char *request; 1416 int i, r; 1417 1418 if ((r = sshbuf_get_cstring(iqueue, &request, NULL)) != 0) 1419 fatal_fr(r, "parse"); 1420 for (i = 0; extended_handlers[i].handler != NULL; i++) { 1421 if (strcmp(request, extended_handlers[i].ext_name) == 0) { 1422 if (!request_permitted(&extended_handlers[i])) 1423 send_status(id, SSH2_FX_PERMISSION_DENIED); 1424 else 1425 extended_handlers[i].handler(id); 1426 break; 1427 } 1428 } 1429 if (extended_handlers[i].handler == NULL) { 1430 error("Unknown extended request \"%.100s\"", request); 1431 send_status(id, SSH2_FX_OP_UNSUPPORTED); /* MUST */ 1432 } 1433 free(request); 1434 } 1435 1436 /* stolen from ssh-agent */ 1437 1438 static void 1439 process(void) 1440 { 1441 u_int msg_len; 1442 u_int buf_len; 1443 u_int consumed; 1444 u_char type; 1445 const u_char *cp; 1446 int i, r; 1447 u_int32_t id; 1448 1449 buf_len = sshbuf_len(iqueue); 1450 if (buf_len < 5) 1451 return; /* Incomplete message. */ 1452 cp = sshbuf_ptr(iqueue); 1453 msg_len = get_u32(cp); 1454 if (msg_len > SFTP_MAX_MSG_LENGTH) { 1455 error("bad message from %s local user %s", 1456 client_addr, pw->pw_name); 1457 sftp_server_cleanup_exit(11); 1458 } 1459 if (buf_len < msg_len + 4) 1460 return; 1461 if ((r = sshbuf_consume(iqueue, 4)) != 0) 1462 fatal_fr(r, "consume"); 1463 buf_len -= 4; 1464 if ((r = sshbuf_get_u8(iqueue, &type)) != 0) 1465 fatal_fr(r, "parse type"); 1466 1467 switch (type) { 1468 case SSH2_FXP_INIT: 1469 process_init(); 1470 init_done = 1; 1471 break; 1472 case SSH2_FXP_EXTENDED: 1473 if (!init_done) 1474 fatal("Received extended request before init"); 1475 if ((r = sshbuf_get_u32(iqueue, &id)) != 0) 1476 fatal_fr(r, "parse extended ID"); 1477 process_extended(id); 1478 break; 1479 default: 1480 if (!init_done) 1481 fatal("Received %u request before init", type); 1482 if ((r = sshbuf_get_u32(iqueue, &id)) != 0) 1483 fatal_fr(r, "parse ID"); 1484 for (i = 0; handlers[i].handler != NULL; i++) { 1485 if (type == handlers[i].type) { 1486 if (!request_permitted(&handlers[i])) { 1487 send_status(id, 1488 SSH2_FX_PERMISSION_DENIED); 1489 } else { 1490 handlers[i].handler(id); 1491 } 1492 break; 1493 } 1494 } 1495 if (handlers[i].handler == NULL) 1496 error("Unknown message %u", type); 1497 } 1498 /* discard the remaining bytes from the current packet */ 1499 if (buf_len < sshbuf_len(iqueue)) { 1500 error("iqueue grew unexpectedly"); 1501 sftp_server_cleanup_exit(255); 1502 } 1503 consumed = buf_len - sshbuf_len(iqueue); 1504 if (msg_len < consumed) { 1505 error("msg_len %u < consumed %u", msg_len, consumed); 1506 sftp_server_cleanup_exit(255); 1507 } 1508 if (msg_len > consumed && 1509 (r = sshbuf_consume(iqueue, msg_len - consumed)) != 0) 1510 fatal_fr(r, "consume"); 1511 } 1512 1513 /* Cleanup handler that logs active handles upon normal exit */ 1514 void 1515 sftp_server_cleanup_exit(int i) 1516 { 1517 if (pw != NULL && client_addr != NULL) { 1518 handle_log_exit(); 1519 logit("session closed for local user %s from [%s]", 1520 pw->pw_name, client_addr); 1521 } 1522 _exit(i); 1523 } 1524 1525 static void 1526 sftp_server_usage(void) 1527 { 1528 extern char *__progname; 1529 1530 fprintf(stderr, 1531 "usage: %s [-ehR] [-d start_directory] [-f log_facility] " 1532 "[-l log_level]\n\t[-P denied_requests] " 1533 "[-p allowed_requests] [-u umask]\n" 1534 " %s -Q protocol_feature\n", 1535 __progname, __progname); 1536 exit(1); 1537 } 1538 1539 int 1540 sftp_server_main(int argc, char **argv, struct passwd *user_pw) 1541 { 1542 fd_set *rset, *wset; 1543 int i, r, in, out, max, ch, skipargs = 0, log_stderr = 0; 1544 ssize_t len, olen, set_size; 1545 SyslogFacility log_facility = SYSLOG_FACILITY_AUTH; 1546 char *cp, *homedir = NULL, uidstr[32], buf[4*4096]; 1547 long mask; 1548 1549 extern char *optarg; 1550 extern char *__progname; 1551 1552 log_init(__progname, log_level, log_facility, log_stderr); 1553 1554 pw = pwcopy(user_pw); 1555 1556 while (!skipargs && (ch = getopt(argc, argv, 1557 "d:f:l:P:p:Q:u:cehR")) != -1) { 1558 switch (ch) { 1559 case 'Q': 1560 if (strcasecmp(optarg, "requests") != 0) { 1561 fprintf(stderr, "Invalid query type\n"); 1562 exit(1); 1563 } 1564 for (i = 0; handlers[i].handler != NULL; i++) 1565 printf("%s\n", handlers[i].name); 1566 for (i = 0; extended_handlers[i].handler != NULL; i++) 1567 printf("%s\n", extended_handlers[i].name); 1568 exit(0); 1569 break; 1570 case 'R': 1571 readonly = 1; 1572 break; 1573 case 'c': 1574 /* 1575 * Ignore all arguments if we are invoked as a 1576 * shell using "sftp-server -c command" 1577 */ 1578 skipargs = 1; 1579 break; 1580 case 'e': 1581 log_stderr = 1; 1582 break; 1583 case 'l': 1584 log_level = log_level_number(optarg); 1585 if (log_level == SYSLOG_LEVEL_NOT_SET) 1586 error("Invalid log level \"%s\"", optarg); 1587 break; 1588 case 'f': 1589 log_facility = log_facility_number(optarg); 1590 if (log_facility == SYSLOG_FACILITY_NOT_SET) 1591 error("Invalid log facility \"%s\"", optarg); 1592 break; 1593 case 'd': 1594 cp = tilde_expand_filename(optarg, user_pw->pw_uid); 1595 snprintf(uidstr, sizeof(uidstr), "%llu", 1596 (unsigned long long)pw->pw_uid); 1597 homedir = percent_expand(cp, "d", user_pw->pw_dir, 1598 "u", user_pw->pw_name, "U", uidstr, (char *)NULL); 1599 free(cp); 1600 break; 1601 case 'p': 1602 if (request_allowlist != NULL) 1603 fatal("Permitted requests already set"); 1604 request_allowlist = xstrdup(optarg); 1605 break; 1606 case 'P': 1607 if (request_denylist != NULL) 1608 fatal("Refused requests already set"); 1609 request_denylist = xstrdup(optarg); 1610 break; 1611 case 'u': 1612 errno = 0; 1613 mask = strtol(optarg, &cp, 8); 1614 if (mask < 0 || mask > 0777 || *cp != '\0' || 1615 cp == optarg || (mask == 0 && errno != 0)) 1616 fatal("Invalid umask \"%s\"", optarg); 1617 (void)umask((mode_t)mask); 1618 break; 1619 case 'h': 1620 default: 1621 sftp_server_usage(); 1622 } 1623 } 1624 1625 log_init(__progname, log_level, log_facility, log_stderr); 1626 1627 if ((cp = getenv("SSH_CONNECTION")) != NULL) { 1628 client_addr = xstrdup(cp); 1629 if ((cp = strchr(client_addr, ' ')) == NULL) { 1630 error("Malformed SSH_CONNECTION variable: \"%s\"", 1631 getenv("SSH_CONNECTION")); 1632 sftp_server_cleanup_exit(255); 1633 } 1634 *cp = '\0'; 1635 } else 1636 client_addr = xstrdup("UNKNOWN"); 1637 1638 logit("session opened for local user %s from [%s]", 1639 pw->pw_name, client_addr); 1640 1641 in = STDIN_FILENO; 1642 out = STDOUT_FILENO; 1643 1644 max = 0; 1645 if (in > max) 1646 max = in; 1647 if (out > max) 1648 max = out; 1649 1650 if ((iqueue = sshbuf_new()) == NULL) 1651 fatal_f("sshbuf_new failed"); 1652 if ((oqueue = sshbuf_new()) == NULL) 1653 fatal_f("sshbuf_new failed"); 1654 1655 rset = xcalloc(howmany(max + 1, NFDBITS), sizeof(fd_mask)); 1656 wset = xcalloc(howmany(max + 1, NFDBITS), sizeof(fd_mask)); 1657 1658 if (homedir != NULL) { 1659 if (chdir(homedir) != 0) { 1660 error("chdir to \"%s\" failed: %s", homedir, 1661 strerror(errno)); 1662 } 1663 } 1664 1665 set_size = howmany(max + 1, NFDBITS) * sizeof(fd_mask); 1666 for (;;) { 1667 memset(rset, 0, set_size); 1668 memset(wset, 0, set_size); 1669 1670 /* 1671 * Ensure that we can read a full buffer and handle 1672 * the worst-case length packet it can generate, 1673 * otherwise apply backpressure by stopping reads. 1674 */ 1675 if ((r = sshbuf_check_reserve(iqueue, sizeof(buf))) == 0 && 1676 (r = sshbuf_check_reserve(oqueue, 1677 SFTP_MAX_MSG_LENGTH)) == 0) 1678 FD_SET(in, rset); 1679 else if (r != SSH_ERR_NO_BUFFER_SPACE) 1680 fatal_fr(r, "reserve"); 1681 1682 olen = sshbuf_len(oqueue); 1683 if (olen > 0) 1684 FD_SET(out, wset); 1685 1686 if (select(max+1, rset, wset, NULL, NULL) == -1) { 1687 if (errno == EINTR) 1688 continue; 1689 error("select: %s", strerror(errno)); 1690 sftp_server_cleanup_exit(2); 1691 } 1692 1693 /* copy stdin to iqueue */ 1694 if (FD_ISSET(in, rset)) { 1695 len = read(in, buf, sizeof buf); 1696 if (len == 0) { 1697 debug("read eof"); 1698 sftp_server_cleanup_exit(0); 1699 } else if (len == -1) { 1700 error("read: %s", strerror(errno)); 1701 sftp_server_cleanup_exit(1); 1702 } else if ((r = sshbuf_put(iqueue, buf, len)) != 0) 1703 fatal_fr(r, "sshbuf_put"); 1704 } 1705 /* send oqueue to stdout */ 1706 if (FD_ISSET(out, wset)) { 1707 len = write(out, sshbuf_ptr(oqueue), olen); 1708 if (len == -1) { 1709 error("write: %s", strerror(errno)); 1710 sftp_server_cleanup_exit(1); 1711 } else if ((r = sshbuf_consume(oqueue, len)) != 0) 1712 fatal_fr(r, "consume"); 1713 } 1714 1715 /* 1716 * Process requests from client if we can fit the results 1717 * into the output buffer, otherwise stop processing input 1718 * and let the output queue drain. 1719 */ 1720 r = sshbuf_check_reserve(oqueue, SFTP_MAX_MSG_LENGTH); 1721 if (r == 0) 1722 process(); 1723 else if (r != SSH_ERR_NO_BUFFER_SPACE) 1724 fatal_fr(r, "reserve"); 1725 } 1726 } 1727