1 /* $OpenBSD: sftp-server.c,v 1.122 2021/02/18 00:30:17 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 <stdlib.h> 29 #include <stdio.h> 30 #include <string.h> 31 #include <pwd.h> 32 #include <time.h> 33 #include <unistd.h> 34 #include <stdarg.h> 35 36 #include "xmalloc.h" 37 #include "sshbuf.h" 38 #include "ssherr.h" 39 #include "log.h" 40 #include "misc.h" 41 #include "match.h" 42 #include "uidswap.h" 43 44 #include "sftp.h" 45 #include "sftp-common.h" 46 47 char *sftp_realpath(const char *, char *); /* sftp-realpath.c */ 48 49 /* Maximum data read that we are willing to accept */ 50 #define SFTP_MAX_READ_LENGTH (64 * 1024) 51 52 /* Our verbosity */ 53 static LogLevel log_level = SYSLOG_LEVEL_ERROR; 54 55 /* Our client */ 56 static struct passwd *pw = NULL; 57 static char *client_addr = NULL; 58 59 /* input and output queue */ 60 struct sshbuf *iqueue; 61 struct sshbuf *oqueue; 62 63 /* Version of client */ 64 static u_int version; 65 66 /* SSH2_FXP_INIT received */ 67 static int init_done; 68 69 /* Disable writes */ 70 static int readonly; 71 72 /* Requests that are allowed/denied */ 73 static char *request_allowlist, *request_denylist; 74 75 /* portable attributes, etc. */ 76 typedef struct Stat Stat; 77 78 struct Stat { 79 char *name; 80 char *long_name; 81 Attrib attrib; 82 }; 83 84 /* Packet handlers */ 85 static void process_open(u_int32_t id); 86 static void process_close(u_int32_t id); 87 static void process_read(u_int32_t id); 88 static void process_write(u_int32_t id); 89 static void process_stat(u_int32_t id); 90 static void process_lstat(u_int32_t id); 91 static void process_fstat(u_int32_t id); 92 static void process_setstat(u_int32_t id); 93 static void process_fsetstat(u_int32_t id); 94 static void process_opendir(u_int32_t id); 95 static void process_readdir(u_int32_t id); 96 static void process_remove(u_int32_t id); 97 static void process_mkdir(u_int32_t id); 98 static void process_rmdir(u_int32_t id); 99 static void process_realpath(u_int32_t id); 100 static void process_rename(u_int32_t id); 101 static void process_readlink(u_int32_t id); 102 static void process_symlink(u_int32_t id); 103 static void process_extended_posix_rename(u_int32_t id); 104 static void process_extended_statvfs(u_int32_t id); 105 static void process_extended_fstatvfs(u_int32_t id); 106 static void process_extended_hardlink(u_int32_t id); 107 static void process_extended_fsync(u_int32_t id); 108 static void process_extended_lsetstat(u_int32_t id); 109 static void process_extended_limits(u_int32_t id); 110 static void process_extended(u_int32_t id); 111 112 struct sftp_handler { 113 const char *name; /* user-visible name for fine-grained perms */ 114 const char *ext_name; /* extended request name */ 115 u_int type; /* packet type, for non extended packets */ 116 void (*handler)(u_int32_t); 117 int does_write; /* if nonzero, banned for readonly mode */ 118 }; 119 120 static const struct sftp_handler handlers[] = { 121 /* NB. SSH2_FXP_OPEN does the readonly check in the handler itself */ 122 { "open", NULL, SSH2_FXP_OPEN, process_open, 0 }, 123 { "close", NULL, SSH2_FXP_CLOSE, process_close, 0 }, 124 { "read", NULL, SSH2_FXP_READ, process_read, 0 }, 125 { "write", NULL, SSH2_FXP_WRITE, process_write, 1 }, 126 { "lstat", NULL, SSH2_FXP_LSTAT, process_lstat, 0 }, 127 { "fstat", NULL, SSH2_FXP_FSTAT, process_fstat, 0 }, 128 { "setstat", NULL, SSH2_FXP_SETSTAT, process_setstat, 1 }, 129 { "fsetstat", NULL, SSH2_FXP_FSETSTAT, process_fsetstat, 1 }, 130 { "opendir", NULL, SSH2_FXP_OPENDIR, process_opendir, 0 }, 131 { "readdir", NULL, SSH2_FXP_READDIR, process_readdir, 0 }, 132 { "remove", NULL, SSH2_FXP_REMOVE, process_remove, 1 }, 133 { "mkdir", NULL, SSH2_FXP_MKDIR, process_mkdir, 1 }, 134 { "rmdir", NULL, SSH2_FXP_RMDIR, process_rmdir, 1 }, 135 { "realpath", NULL, SSH2_FXP_REALPATH, process_realpath, 0 }, 136 { "stat", NULL, SSH2_FXP_STAT, process_stat, 0 }, 137 { "rename", NULL, SSH2_FXP_RENAME, process_rename, 1 }, 138 { "readlink", NULL, SSH2_FXP_READLINK, process_readlink, 0 }, 139 { "symlink", NULL, SSH2_FXP_SYMLINK, process_symlink, 1 }, 140 { NULL, NULL, 0, NULL, 0 } 141 }; 142 143 /* SSH2_FXP_EXTENDED submessages */ 144 static const struct sftp_handler extended_handlers[] = { 145 { "posix-rename", "posix-rename@openssh.com", 0, 146 process_extended_posix_rename, 1 }, 147 { "statvfs", "statvfs@openssh.com", 0, process_extended_statvfs, 0 }, 148 { "fstatvfs", "fstatvfs@openssh.com", 0, process_extended_fstatvfs, 0 }, 149 { "hardlink", "hardlink@openssh.com", 0, process_extended_hardlink, 1 }, 150 { "fsync", "fsync@openssh.com", 0, process_extended_fsync, 1 }, 151 { "lsetstat", "lsetstat@openssh.com", 0, process_extended_lsetstat, 1 }, 152 { "limits", "limits@openssh.com", 0, process_extended_limits, 1 }, 153 { NULL, NULL, 0, NULL, 0 } 154 }; 155 156 static int 157 request_permitted(const struct sftp_handler *h) 158 { 159 char *result; 160 161 if (readonly && h->does_write) { 162 verbose("Refusing %s request in read-only mode", h->name); 163 return 0; 164 } 165 if (request_denylist != NULL && 166 ((result = match_list(h->name, request_denylist, NULL))) != NULL) { 167 free(result); 168 verbose("Refusing denylisted %s request", h->name); 169 return 0; 170 } 171 if (request_allowlist != NULL && 172 ((result = match_list(h->name, request_allowlist, NULL))) != NULL) { 173 free(result); 174 debug2("Permitting allowlisted %s request", h->name); 175 return 1; 176 } 177 if (request_allowlist != NULL) { 178 verbose("Refusing non-allowlisted %s request", h->name); 179 return 0; 180 } 181 return 1; 182 } 183 184 static int 185 errno_to_portable(int unixerrno) 186 { 187 int ret = 0; 188 189 switch (unixerrno) { 190 case 0: 191 ret = SSH2_FX_OK; 192 break; 193 case ENOENT: 194 case ENOTDIR: 195 case EBADF: 196 case ELOOP: 197 ret = SSH2_FX_NO_SUCH_FILE; 198 break; 199 case EPERM: 200 case EACCES: 201 case EFAULT: 202 ret = SSH2_FX_PERMISSION_DENIED; 203 break; 204 case ENAMETOOLONG: 205 case EINVAL: 206 ret = SSH2_FX_BAD_MESSAGE; 207 break; 208 case ENOSYS: 209 ret = SSH2_FX_OP_UNSUPPORTED; 210 break; 211 default: 212 ret = SSH2_FX_FAILURE; 213 break; 214 } 215 return ret; 216 } 217 218 static int 219 flags_from_portable(int pflags) 220 { 221 int flags = 0; 222 223 if ((pflags & SSH2_FXF_READ) && 224 (pflags & SSH2_FXF_WRITE)) { 225 flags = O_RDWR; 226 } else if (pflags & SSH2_FXF_READ) { 227 flags = O_RDONLY; 228 } else if (pflags & SSH2_FXF_WRITE) { 229 flags = O_WRONLY; 230 } 231 if (pflags & SSH2_FXF_APPEND) 232 flags |= O_APPEND; 233 if (pflags & SSH2_FXF_CREAT) 234 flags |= O_CREAT; 235 if (pflags & SSH2_FXF_TRUNC) 236 flags |= O_TRUNC; 237 if (pflags & SSH2_FXF_EXCL) 238 flags |= O_EXCL; 239 return flags; 240 } 241 242 static const char * 243 string_from_portable(int pflags) 244 { 245 static char ret[128]; 246 247 *ret = '\0'; 248 249 #define PAPPEND(str) { \ 250 if (*ret != '\0') \ 251 strlcat(ret, ",", sizeof(ret)); \ 252 strlcat(ret, str, sizeof(ret)); \ 253 } 254 255 if (pflags & SSH2_FXF_READ) 256 PAPPEND("READ") 257 if (pflags & SSH2_FXF_WRITE) 258 PAPPEND("WRITE") 259 if (pflags & SSH2_FXF_APPEND) 260 PAPPEND("APPEND") 261 if (pflags & SSH2_FXF_CREAT) 262 PAPPEND("CREATE") 263 if (pflags & SSH2_FXF_TRUNC) 264 PAPPEND("TRUNCATE") 265 if (pflags & SSH2_FXF_EXCL) 266 PAPPEND("EXCL") 267 268 return ret; 269 } 270 271 /* handle handles */ 272 273 typedef struct Handle Handle; 274 struct Handle { 275 int use; 276 DIR *dirp; 277 int fd; 278 int flags; 279 char *name; 280 u_int64_t bytes_read, bytes_write; 281 int next_unused; 282 }; 283 284 enum { 285 HANDLE_UNUSED, 286 HANDLE_DIR, 287 HANDLE_FILE 288 }; 289 290 static Handle *handles = NULL; 291 static u_int num_handles = 0; 292 static int first_unused_handle = -1; 293 294 static void handle_unused(int i) 295 { 296 handles[i].use = HANDLE_UNUSED; 297 handles[i].next_unused = first_unused_handle; 298 first_unused_handle = i; 299 } 300 301 static int 302 handle_new(int use, const char *name, int fd, int flags, DIR *dirp) 303 { 304 int i; 305 306 if (first_unused_handle == -1) { 307 if (num_handles + 1 <= num_handles) 308 return -1; 309 num_handles++; 310 handles = xreallocarray(handles, num_handles, sizeof(Handle)); 311 handle_unused(num_handles - 1); 312 } 313 314 i = first_unused_handle; 315 first_unused_handle = handles[i].next_unused; 316 317 handles[i].use = use; 318 handles[i].dirp = dirp; 319 handles[i].fd = fd; 320 handles[i].flags = flags; 321 handles[i].name = xstrdup(name); 322 handles[i].bytes_read = handles[i].bytes_write = 0; 323 324 return i; 325 } 326 327 static int 328 handle_is_ok(int i, int type) 329 { 330 return i >= 0 && (u_int)i < num_handles && handles[i].use == type; 331 } 332 333 static int 334 handle_to_string(int handle, u_char **stringp, int *hlenp) 335 { 336 if (stringp == NULL || hlenp == NULL) 337 return -1; 338 *stringp = xmalloc(sizeof(int32_t)); 339 put_u32(*stringp, handle); 340 *hlenp = sizeof(int32_t); 341 return 0; 342 } 343 344 static int 345 handle_from_string(const u_char *handle, u_int hlen) 346 { 347 int val; 348 349 if (hlen != sizeof(int32_t)) 350 return -1; 351 val = get_u32(handle); 352 if (handle_is_ok(val, HANDLE_FILE) || 353 handle_is_ok(val, HANDLE_DIR)) 354 return val; 355 return -1; 356 } 357 358 static char * 359 handle_to_name(int handle) 360 { 361 if (handle_is_ok(handle, HANDLE_DIR)|| 362 handle_is_ok(handle, HANDLE_FILE)) 363 return handles[handle].name; 364 return NULL; 365 } 366 367 static DIR * 368 handle_to_dir(int handle) 369 { 370 if (handle_is_ok(handle, HANDLE_DIR)) 371 return handles[handle].dirp; 372 return NULL; 373 } 374 375 static int 376 handle_to_fd(int handle) 377 { 378 if (handle_is_ok(handle, HANDLE_FILE)) 379 return handles[handle].fd; 380 return -1; 381 } 382 383 static int 384 handle_to_flags(int handle) 385 { 386 if (handle_is_ok(handle, HANDLE_FILE)) 387 return handles[handle].flags; 388 return 0; 389 } 390 391 static void 392 handle_update_read(int handle, ssize_t bytes) 393 { 394 if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0) 395 handles[handle].bytes_read += bytes; 396 } 397 398 static void 399 handle_update_write(int handle, ssize_t bytes) 400 { 401 if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0) 402 handles[handle].bytes_write += bytes; 403 } 404 405 static u_int64_t 406 handle_bytes_read(int handle) 407 { 408 if (handle_is_ok(handle, HANDLE_FILE)) 409 return (handles[handle].bytes_read); 410 return 0; 411 } 412 413 static u_int64_t 414 handle_bytes_write(int handle) 415 { 416 if (handle_is_ok(handle, HANDLE_FILE)) 417 return (handles[handle].bytes_write); 418 return 0; 419 } 420 421 static int 422 handle_close(int handle) 423 { 424 int ret = -1; 425 426 if (handle_is_ok(handle, HANDLE_FILE)) { 427 ret = close(handles[handle].fd); 428 free(handles[handle].name); 429 handle_unused(handle); 430 } else if (handle_is_ok(handle, HANDLE_DIR)) { 431 ret = closedir(handles[handle].dirp); 432 free(handles[handle].name); 433 handle_unused(handle); 434 } else { 435 errno = ENOENT; 436 } 437 return ret; 438 } 439 440 static void 441 handle_log_close(int handle, char *emsg) 442 { 443 if (handle_is_ok(handle, HANDLE_FILE)) { 444 logit("%s%sclose \"%s\" bytes read %llu written %llu", 445 emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ", 446 handle_to_name(handle), 447 (unsigned long long)handle_bytes_read(handle), 448 (unsigned long long)handle_bytes_write(handle)); 449 } else { 450 logit("%s%sclosedir \"%s\"", 451 emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ", 452 handle_to_name(handle)); 453 } 454 } 455 456 static void 457 handle_log_exit(void) 458 { 459 u_int i; 460 461 for (i = 0; i < num_handles; i++) 462 if (handles[i].use != HANDLE_UNUSED) 463 handle_log_close(i, "forced"); 464 } 465 466 static int 467 get_handle(struct sshbuf *queue, int *hp) 468 { 469 u_char *handle; 470 int r; 471 size_t hlen; 472 473 *hp = -1; 474 if ((r = sshbuf_get_string(queue, &handle, &hlen)) != 0) 475 return r; 476 if (hlen < 256) 477 *hp = handle_from_string(handle, hlen); 478 free(handle); 479 return 0; 480 } 481 482 /* send replies */ 483 484 static void 485 send_msg(struct sshbuf *m) 486 { 487 int r; 488 489 if ((r = sshbuf_put_stringb(oqueue, m)) != 0) 490 fatal_fr(r, "enqueue"); 491 sshbuf_reset(m); 492 } 493 494 static const char * 495 status_to_message(u_int32_t status) 496 { 497 const char *status_messages[] = { 498 "Success", /* SSH_FX_OK */ 499 "End of file", /* SSH_FX_EOF */ 500 "No such file", /* SSH_FX_NO_SUCH_FILE */ 501 "Permission denied", /* SSH_FX_PERMISSION_DENIED */ 502 "Failure", /* SSH_FX_FAILURE */ 503 "Bad message", /* SSH_FX_BAD_MESSAGE */ 504 "No connection", /* SSH_FX_NO_CONNECTION */ 505 "Connection lost", /* SSH_FX_CONNECTION_LOST */ 506 "Operation unsupported", /* SSH_FX_OP_UNSUPPORTED */ 507 "Unknown error" /* Others */ 508 }; 509 return (status_messages[MINIMUM(status,SSH2_FX_MAX)]); 510 } 511 512 static void 513 send_status(u_int32_t id, u_int32_t status) 514 { 515 struct sshbuf *msg; 516 int r; 517 518 debug3("request %u: sent status %u", id, status); 519 if (log_level > SYSLOG_LEVEL_VERBOSE || 520 (status != SSH2_FX_OK && status != SSH2_FX_EOF)) 521 logit("sent status %s", status_to_message(status)); 522 if ((msg = sshbuf_new()) == NULL) 523 fatal_f("sshbuf_new failed"); 524 if ((r = sshbuf_put_u8(msg, SSH2_FXP_STATUS)) != 0 || 525 (r = sshbuf_put_u32(msg, id)) != 0 || 526 (r = sshbuf_put_u32(msg, status)) != 0) 527 fatal_fr(r, "compose"); 528 if (version >= 3) { 529 if ((r = sshbuf_put_cstring(msg, 530 status_to_message(status))) != 0 || 531 (r = sshbuf_put_cstring(msg, "")) != 0) 532 fatal_fr(r, "compose message"); 533 } 534 send_msg(msg); 535 sshbuf_free(msg); 536 } 537 static void 538 send_data_or_handle(char type, u_int32_t id, const u_char *data, int dlen) 539 { 540 struct sshbuf *msg; 541 int r; 542 543 if ((msg = sshbuf_new()) == NULL) 544 fatal_f("sshbuf_new failed"); 545 if ((r = sshbuf_put_u8(msg, type)) != 0 || 546 (r = sshbuf_put_u32(msg, id)) != 0 || 547 (r = sshbuf_put_string(msg, data, dlen)) != 0) 548 fatal_fr(r, "compose"); 549 send_msg(msg); 550 sshbuf_free(msg); 551 } 552 553 static void 554 send_data(u_int32_t id, const u_char *data, int dlen) 555 { 556 debug("request %u: sent data len %d", id, dlen); 557 send_data_or_handle(SSH2_FXP_DATA, id, data, dlen); 558 } 559 560 static void 561 send_handle(u_int32_t id, int handle) 562 { 563 u_char *string; 564 int hlen; 565 566 handle_to_string(handle, &string, &hlen); 567 debug("request %u: sent handle handle %d", id, handle); 568 send_data_or_handle(SSH2_FXP_HANDLE, id, string, hlen); 569 free(string); 570 } 571 572 static void 573 send_names(u_int32_t id, int count, const Stat *stats) 574 { 575 struct sshbuf *msg; 576 int i, r; 577 578 if ((msg = sshbuf_new()) == NULL) 579 fatal_f("sshbuf_new failed"); 580 if ((r = sshbuf_put_u8(msg, SSH2_FXP_NAME)) != 0 || 581 (r = sshbuf_put_u32(msg, id)) != 0 || 582 (r = sshbuf_put_u32(msg, count)) != 0) 583 fatal_fr(r, "compose"); 584 debug("request %u: sent names count %d", id, count); 585 for (i = 0; i < count; i++) { 586 if ((r = sshbuf_put_cstring(msg, stats[i].name)) != 0 || 587 (r = sshbuf_put_cstring(msg, stats[i].long_name)) != 0 || 588 (r = encode_attrib(msg, &stats[i].attrib)) != 0) 589 fatal_fr(r, "compose filenames/attrib"); 590 } 591 send_msg(msg); 592 sshbuf_free(msg); 593 } 594 595 static void 596 send_attrib(u_int32_t id, const Attrib *a) 597 { 598 struct sshbuf *msg; 599 int r; 600 601 debug("request %u: sent attrib have 0x%x", id, a->flags); 602 if ((msg = sshbuf_new()) == NULL) 603 fatal_f("sshbuf_new failed"); 604 if ((r = sshbuf_put_u8(msg, SSH2_FXP_ATTRS)) != 0 || 605 (r = sshbuf_put_u32(msg, id)) != 0 || 606 (r = encode_attrib(msg, a)) != 0) 607 fatal_fr(r, "compose"); 608 send_msg(msg); 609 sshbuf_free(msg); 610 } 611 612 static void 613 send_statvfs(u_int32_t id, struct statvfs *st) 614 { 615 struct sshbuf *msg; 616 u_int64_t flag; 617 int r; 618 619 flag = (st->f_flag & ST_RDONLY) ? SSH2_FXE_STATVFS_ST_RDONLY : 0; 620 flag |= (st->f_flag & ST_NOSUID) ? SSH2_FXE_STATVFS_ST_NOSUID : 0; 621 622 if ((msg = sshbuf_new()) == NULL) 623 fatal_f("sshbuf_new failed"); 624 if ((r = sshbuf_put_u8(msg, SSH2_FXP_EXTENDED_REPLY)) != 0 || 625 (r = sshbuf_put_u32(msg, id)) != 0 || 626 (r = sshbuf_put_u64(msg, st->f_bsize)) != 0 || 627 (r = sshbuf_put_u64(msg, st->f_frsize)) != 0 || 628 (r = sshbuf_put_u64(msg, st->f_blocks)) != 0 || 629 (r = sshbuf_put_u64(msg, st->f_bfree)) != 0 || 630 (r = sshbuf_put_u64(msg, st->f_bavail)) != 0 || 631 (r = sshbuf_put_u64(msg, st->f_files)) != 0 || 632 (r = sshbuf_put_u64(msg, st->f_ffree)) != 0 || 633 (r = sshbuf_put_u64(msg, st->f_favail)) != 0 || 634 (r = sshbuf_put_u64(msg, st->f_fsid)) != 0 || 635 (r = sshbuf_put_u64(msg, flag)) != 0 || 636 (r = sshbuf_put_u64(msg, st->f_namemax)) != 0) 637 fatal_fr(r, "compose"); 638 send_msg(msg); 639 sshbuf_free(msg); 640 } 641 642 /* parse incoming */ 643 644 static void 645 process_init(void) 646 { 647 struct sshbuf *msg; 648 int r; 649 650 if ((r = sshbuf_get_u32(iqueue, &version)) != 0) 651 fatal_fr(r, "parse"); 652 verbose("received client version %u", version); 653 if ((msg = sshbuf_new()) == NULL) 654 fatal_f("sshbuf_new failed"); 655 if ((r = sshbuf_put_u8(msg, SSH2_FXP_VERSION)) != 0 || 656 (r = sshbuf_put_u32(msg, SSH2_FILEXFER_VERSION)) != 0 || 657 /* POSIX rename extension */ 658 (r = sshbuf_put_cstring(msg, "posix-rename@openssh.com")) != 0 || 659 (r = sshbuf_put_cstring(msg, "1")) != 0 || /* version */ 660 /* statvfs extension */ 661 (r = sshbuf_put_cstring(msg, "statvfs@openssh.com")) != 0 || 662 (r = sshbuf_put_cstring(msg, "2")) != 0 || /* version */ 663 /* fstatvfs extension */ 664 (r = sshbuf_put_cstring(msg, "fstatvfs@openssh.com")) != 0 || 665 (r = sshbuf_put_cstring(msg, "2")) != 0 || /* version */ 666 /* hardlink extension */ 667 (r = sshbuf_put_cstring(msg, "hardlink@openssh.com")) != 0 || 668 (r = sshbuf_put_cstring(msg, "1")) != 0 || /* version */ 669 /* fsync extension */ 670 (r = sshbuf_put_cstring(msg, "fsync@openssh.com")) != 0 || 671 (r = sshbuf_put_cstring(msg, "1")) != 0 || /* version */ 672 /* lsetstat extension */ 673 (r = sshbuf_put_cstring(msg, "lsetstat@openssh.com")) != 0 || 674 (r = sshbuf_put_cstring(msg, "1")) != 0 || /* version */ 675 /* limits extension */ 676 (r = sshbuf_put_cstring(msg, "limits@openssh.com")) != 0 || 677 (r = sshbuf_put_cstring(msg, "1")) != 0) /* version */ 678 fatal_fr(r, "compose"); 679 send_msg(msg); 680 sshbuf_free(msg); 681 } 682 683 static void 684 process_open(u_int32_t id) 685 { 686 u_int32_t pflags; 687 Attrib a; 688 char *name; 689 int r, handle, fd, flags, mode, status = SSH2_FX_FAILURE; 690 691 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 || 692 (r = sshbuf_get_u32(iqueue, &pflags)) != 0 || /* portable flags */ 693 (r = decode_attrib(iqueue, &a)) != 0) 694 fatal_fr(r, "parse"); 695 696 debug3("request %u: open flags %d", id, pflags); 697 flags = flags_from_portable(pflags); 698 mode = (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? a.perm : 0666; 699 logit("open \"%s\" flags %s mode 0%o", 700 name, string_from_portable(pflags), mode); 701 if (readonly && 702 ((flags & O_ACCMODE) != O_RDONLY || 703 (flags & (O_CREAT|O_TRUNC)) != 0)) { 704 verbose("Refusing open request in read-only mode"); 705 status = SSH2_FX_PERMISSION_DENIED; 706 } else { 707 fd = open(name, flags, mode); 708 if (fd == -1) { 709 status = errno_to_portable(errno); 710 } else { 711 handle = handle_new(HANDLE_FILE, name, fd, flags, NULL); 712 if (handle < 0) { 713 close(fd); 714 } else { 715 send_handle(id, handle); 716 status = SSH2_FX_OK; 717 } 718 } 719 } 720 if (status != SSH2_FX_OK) 721 send_status(id, status); 722 free(name); 723 } 724 725 static void 726 process_close(u_int32_t id) 727 { 728 int r, handle, ret, status = SSH2_FX_FAILURE; 729 730 if ((r = get_handle(iqueue, &handle)) != 0) 731 fatal_fr(r, "parse"); 732 733 debug3("request %u: close handle %u", id, handle); 734 handle_log_close(handle, NULL); 735 ret = handle_close(handle); 736 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 737 send_status(id, status); 738 } 739 740 static void 741 process_read(u_int32_t id) 742 { 743 u_char buf[SFTP_MAX_READ_LENGTH]; 744 u_int32_t len; 745 int r, handle, fd, ret, status = SSH2_FX_FAILURE; 746 u_int64_t off; 747 748 if ((r = get_handle(iqueue, &handle)) != 0 || 749 (r = sshbuf_get_u64(iqueue, &off)) != 0 || 750 (r = sshbuf_get_u32(iqueue, &len)) != 0) 751 fatal_fr(r, "parse"); 752 753 debug("request %u: read \"%s\" (handle %d) off %llu len %d", 754 id, handle_to_name(handle), handle, (unsigned long long)off, len); 755 if (len > sizeof buf) { 756 len = sizeof buf; 757 debug2("read change len %d", len); 758 } 759 fd = handle_to_fd(handle); 760 if (fd >= 0) { 761 if (lseek(fd, off, SEEK_SET) == -1) { 762 error("process_read: seek failed"); 763 status = errno_to_portable(errno); 764 } else { 765 ret = read(fd, buf, len); 766 if (ret == -1) { 767 status = errno_to_portable(errno); 768 } else if (ret == 0) { 769 status = SSH2_FX_EOF; 770 } else { 771 send_data(id, buf, ret); 772 status = SSH2_FX_OK; 773 handle_update_read(handle, ret); 774 } 775 } 776 } 777 if (status != SSH2_FX_OK) 778 send_status(id, status); 779 } 780 781 static void 782 process_write(u_int32_t id) 783 { 784 u_int64_t off; 785 size_t len; 786 int r, handle, fd, ret, status; 787 u_char *data; 788 789 if ((r = get_handle(iqueue, &handle)) != 0 || 790 (r = sshbuf_get_u64(iqueue, &off)) != 0 || 791 (r = sshbuf_get_string(iqueue, &data, &len)) != 0) 792 fatal_fr(r, "parse"); 793 794 debug("request %u: write \"%s\" (handle %d) off %llu len %zu", 795 id, handle_to_name(handle), handle, (unsigned long long)off, len); 796 fd = handle_to_fd(handle); 797 798 if (fd < 0) 799 status = SSH2_FX_FAILURE; 800 else { 801 if (!(handle_to_flags(handle) & O_APPEND) && 802 lseek(fd, off, SEEK_SET) == -1) { 803 status = errno_to_portable(errno); 804 error_f("seek failed"); 805 } else { 806 /* XXX ATOMICIO ? */ 807 ret = write(fd, data, len); 808 if (ret == -1) { 809 error_f("write: %s", strerror(errno)); 810 status = errno_to_portable(errno); 811 } else if ((size_t)ret == len) { 812 status = SSH2_FX_OK; 813 handle_update_write(handle, ret); 814 } else { 815 debug2_f("nothing at all written"); 816 status = SSH2_FX_FAILURE; 817 } 818 } 819 } 820 send_status(id, status); 821 free(data); 822 } 823 824 static void 825 process_do_stat(u_int32_t id, int do_lstat) 826 { 827 Attrib a; 828 struct stat st; 829 char *name; 830 int r, status = SSH2_FX_FAILURE; 831 832 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0) 833 fatal_fr(r, "parse"); 834 835 debug3("request %u: %sstat", id, do_lstat ? "l" : ""); 836 verbose("%sstat name \"%s\"", do_lstat ? "l" : "", name); 837 r = do_lstat ? lstat(name, &st) : stat(name, &st); 838 if (r == -1) { 839 status = errno_to_portable(errno); 840 } else { 841 stat_to_attrib(&st, &a); 842 send_attrib(id, &a); 843 status = SSH2_FX_OK; 844 } 845 if (status != SSH2_FX_OK) 846 send_status(id, status); 847 free(name); 848 } 849 850 static void 851 process_stat(u_int32_t id) 852 { 853 process_do_stat(id, 0); 854 } 855 856 static void 857 process_lstat(u_int32_t id) 858 { 859 process_do_stat(id, 1); 860 } 861 862 static void 863 process_fstat(u_int32_t id) 864 { 865 Attrib a; 866 struct stat st; 867 int fd, r, handle, status = SSH2_FX_FAILURE; 868 869 if ((r = get_handle(iqueue, &handle)) != 0) 870 fatal_fr(r, "parse"); 871 debug("request %u: fstat \"%s\" (handle %u)", 872 id, handle_to_name(handle), handle); 873 fd = handle_to_fd(handle); 874 if (fd >= 0) { 875 r = fstat(fd, &st); 876 if (r == -1) { 877 status = errno_to_portable(errno); 878 } else { 879 stat_to_attrib(&st, &a); 880 send_attrib(id, &a); 881 status = SSH2_FX_OK; 882 } 883 } 884 if (status != SSH2_FX_OK) 885 send_status(id, status); 886 } 887 888 static struct timeval * 889 attrib_to_tv(const Attrib *a) 890 { 891 static struct timeval tv[2]; 892 893 tv[0].tv_sec = a->atime; 894 tv[0].tv_usec = 0; 895 tv[1].tv_sec = a->mtime; 896 tv[1].tv_usec = 0; 897 return tv; 898 } 899 900 static struct timespec * 901 attrib_to_ts(const Attrib *a) 902 { 903 static struct timespec ts[2]; 904 905 ts[0].tv_sec = a->atime; 906 ts[0].tv_nsec = 0; 907 ts[1].tv_sec = a->mtime; 908 ts[1].tv_nsec = 0; 909 return ts; 910 } 911 912 static void 913 process_setstat(u_int32_t id) 914 { 915 Attrib a; 916 char *name; 917 int r, status = SSH2_FX_OK; 918 919 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 || 920 (r = decode_attrib(iqueue, &a)) != 0) 921 fatal_fr(r, "parse"); 922 923 debug("request %u: setstat name \"%s\"", id, name); 924 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) { 925 logit("set \"%s\" size %llu", 926 name, (unsigned long long)a.size); 927 r = truncate(name, a.size); 928 if (r == -1) 929 status = errno_to_portable(errno); 930 } 931 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) { 932 logit("set \"%s\" mode %04o", name, a.perm); 933 r = chmod(name, a.perm & 07777); 934 if (r == -1) 935 status = errno_to_portable(errno); 936 } 937 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) { 938 char buf[64]; 939 time_t t = a.mtime; 940 941 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S", 942 localtime(&t)); 943 logit("set \"%s\" modtime %s", name, buf); 944 r = utimes(name, attrib_to_tv(&a)); 945 if (r == -1) 946 status = errno_to_portable(errno); 947 } 948 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) { 949 logit("set \"%s\" owner %lu group %lu", name, 950 (u_long)a.uid, (u_long)a.gid); 951 r = chown(name, a.uid, a.gid); 952 if (r == -1) 953 status = errno_to_portable(errno); 954 } 955 send_status(id, status); 956 free(name); 957 } 958 959 static void 960 process_fsetstat(u_int32_t id) 961 { 962 Attrib a; 963 int handle, fd, r; 964 int status = SSH2_FX_OK; 965 966 if ((r = get_handle(iqueue, &handle)) != 0 || 967 (r = decode_attrib(iqueue, &a)) != 0) 968 fatal_fr(r, "parse"); 969 970 debug("request %u: fsetstat handle %d", id, handle); 971 fd = handle_to_fd(handle); 972 if (fd < 0) 973 status = SSH2_FX_FAILURE; 974 else { 975 char *name = handle_to_name(handle); 976 977 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) { 978 logit("set \"%s\" size %llu", 979 name, (unsigned long long)a.size); 980 r = ftruncate(fd, a.size); 981 if (r == -1) 982 status = errno_to_portable(errno); 983 } 984 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) { 985 logit("set \"%s\" mode %04o", name, a.perm); 986 r = fchmod(fd, a.perm & 07777); 987 if (r == -1) 988 status = errno_to_portable(errno); 989 } 990 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) { 991 char buf[64]; 992 time_t t = a.mtime; 993 994 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S", 995 localtime(&t)); 996 logit("set \"%s\" modtime %s", name, buf); 997 r = futimes(fd, attrib_to_tv(&a)); 998 if (r == -1) 999 status = errno_to_portable(errno); 1000 } 1001 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) { 1002 logit("set \"%s\" owner %lu group %lu", name, 1003 (u_long)a.uid, (u_long)a.gid); 1004 r = fchown(fd, a.uid, a.gid); 1005 if (r == -1) 1006 status = errno_to_portable(errno); 1007 } 1008 } 1009 send_status(id, status); 1010 } 1011 1012 static void 1013 process_opendir(u_int32_t id) 1014 { 1015 DIR *dirp = NULL; 1016 char *path; 1017 int r, handle, status = SSH2_FX_FAILURE; 1018 1019 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0) 1020 fatal_fr(r, "parse"); 1021 1022 debug3("request %u: opendir", id); 1023 logit("opendir \"%s\"", path); 1024 dirp = opendir(path); 1025 if (dirp == NULL) { 1026 status = errno_to_portable(errno); 1027 } else { 1028 handle = handle_new(HANDLE_DIR, path, 0, 0, dirp); 1029 if (handle < 0) { 1030 closedir(dirp); 1031 } else { 1032 send_handle(id, handle); 1033 status = SSH2_FX_OK; 1034 } 1035 1036 } 1037 if (status != SSH2_FX_OK) 1038 send_status(id, status); 1039 free(path); 1040 } 1041 1042 static void 1043 process_readdir(u_int32_t id) 1044 { 1045 DIR *dirp; 1046 struct dirent *dp; 1047 char *path; 1048 int r, handle; 1049 1050 if ((r = get_handle(iqueue, &handle)) != 0) 1051 fatal_fr(r, "parse"); 1052 1053 debug("request %u: readdir \"%s\" (handle %d)", id, 1054 handle_to_name(handle), handle); 1055 dirp = handle_to_dir(handle); 1056 path = handle_to_name(handle); 1057 if (dirp == NULL || path == NULL) { 1058 send_status(id, SSH2_FX_FAILURE); 1059 } else { 1060 struct stat st; 1061 char pathname[PATH_MAX]; 1062 Stat *stats; 1063 int nstats = 10, count = 0, i; 1064 1065 stats = xcalloc(nstats, sizeof(Stat)); 1066 while ((dp = readdir(dirp)) != NULL) { 1067 if (count >= nstats) { 1068 nstats *= 2; 1069 stats = xreallocarray(stats, nstats, sizeof(Stat)); 1070 } 1071 /* XXX OVERFLOW ? */ 1072 snprintf(pathname, sizeof pathname, "%s%s%s", path, 1073 strcmp(path, "/") ? "/" : "", dp->d_name); 1074 if (lstat(pathname, &st) == -1) 1075 continue; 1076 stat_to_attrib(&st, &(stats[count].attrib)); 1077 stats[count].name = xstrdup(dp->d_name); 1078 stats[count].long_name = ls_file(dp->d_name, &st, 0, 0); 1079 count++; 1080 /* send up to 100 entries in one message */ 1081 /* XXX check packet size instead */ 1082 if (count == 100) 1083 break; 1084 } 1085 if (count > 0) { 1086 send_names(id, count, stats); 1087 for (i = 0; i < count; i++) { 1088 free(stats[i].name); 1089 free(stats[i].long_name); 1090 } 1091 } else { 1092 send_status(id, SSH2_FX_EOF); 1093 } 1094 free(stats); 1095 } 1096 } 1097 1098 static void 1099 process_remove(u_int32_t id) 1100 { 1101 char *name; 1102 int r, status = SSH2_FX_FAILURE; 1103 1104 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0) 1105 fatal_fr(r, "parse"); 1106 1107 debug3("request %u: remove", id); 1108 logit("remove name \"%s\"", name); 1109 r = unlink(name); 1110 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1111 send_status(id, status); 1112 free(name); 1113 } 1114 1115 static void 1116 process_mkdir(u_int32_t id) 1117 { 1118 Attrib a; 1119 char *name; 1120 int r, mode, status = SSH2_FX_FAILURE; 1121 1122 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 || 1123 (r = decode_attrib(iqueue, &a)) != 0) 1124 fatal_fr(r, "parse"); 1125 1126 mode = (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? 1127 a.perm & 07777 : 0777; 1128 debug3("request %u: mkdir", id); 1129 logit("mkdir name \"%s\" mode 0%o", name, mode); 1130 r = mkdir(name, mode); 1131 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1132 send_status(id, status); 1133 free(name); 1134 } 1135 1136 static void 1137 process_rmdir(u_int32_t id) 1138 { 1139 char *name; 1140 int r, status; 1141 1142 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0) 1143 fatal_fr(r, "parse"); 1144 1145 debug3("request %u: rmdir", id); 1146 logit("rmdir name \"%s\"", name); 1147 r = rmdir(name); 1148 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1149 send_status(id, status); 1150 free(name); 1151 } 1152 1153 static void 1154 process_realpath(u_int32_t id) 1155 { 1156 char resolvedname[PATH_MAX]; 1157 char *path; 1158 int r; 1159 1160 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0) 1161 fatal_fr(r, "parse"); 1162 1163 if (path[0] == '\0') { 1164 free(path); 1165 path = xstrdup("."); 1166 } 1167 debug3("request %u: realpath", id); 1168 verbose("realpath \"%s\"", path); 1169 if (sftp_realpath(path, resolvedname) == NULL) { 1170 send_status(id, errno_to_portable(errno)); 1171 } else { 1172 Stat s; 1173 attrib_clear(&s.attrib); 1174 s.name = s.long_name = resolvedname; 1175 send_names(id, 1, &s); 1176 } 1177 free(path); 1178 } 1179 1180 static void 1181 process_rename(u_int32_t id) 1182 { 1183 char *oldpath, *newpath; 1184 int r, status; 1185 struct stat sb; 1186 1187 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 || 1188 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0) 1189 fatal_fr(r, "parse"); 1190 1191 debug3("request %u: rename", id); 1192 logit("rename old \"%s\" new \"%s\"", oldpath, newpath); 1193 status = SSH2_FX_FAILURE; 1194 if (lstat(oldpath, &sb) == -1) 1195 status = errno_to_portable(errno); 1196 else if (S_ISREG(sb.st_mode)) { 1197 /* Race-free rename of regular files */ 1198 if (link(oldpath, newpath) == -1) { 1199 if (errno == EOPNOTSUPP) { 1200 struct stat st; 1201 1202 /* 1203 * fs doesn't support links, so fall back to 1204 * stat+rename. This is racy. 1205 */ 1206 if (stat(newpath, &st) == -1) { 1207 if (rename(oldpath, newpath) == -1) 1208 status = 1209 errno_to_portable(errno); 1210 else 1211 status = SSH2_FX_OK; 1212 } 1213 } else { 1214 status = errno_to_portable(errno); 1215 } 1216 } else if (unlink(oldpath) == -1) { 1217 status = errno_to_portable(errno); 1218 /* clean spare link */ 1219 unlink(newpath); 1220 } else 1221 status = SSH2_FX_OK; 1222 } else if (stat(newpath, &sb) == -1) { 1223 if (rename(oldpath, newpath) == -1) 1224 status = errno_to_portable(errno); 1225 else 1226 status = SSH2_FX_OK; 1227 } 1228 send_status(id, status); 1229 free(oldpath); 1230 free(newpath); 1231 } 1232 1233 static void 1234 process_readlink(u_int32_t id) 1235 { 1236 int r, len; 1237 char buf[PATH_MAX]; 1238 char *path; 1239 1240 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0) 1241 fatal_fr(r, "parse"); 1242 1243 debug3("request %u: readlink", id); 1244 verbose("readlink \"%s\"", path); 1245 if ((len = readlink(path, buf, sizeof(buf) - 1)) == -1) 1246 send_status(id, errno_to_portable(errno)); 1247 else { 1248 Stat s; 1249 1250 buf[len] = '\0'; 1251 attrib_clear(&s.attrib); 1252 s.name = s.long_name = buf; 1253 send_names(id, 1, &s); 1254 } 1255 free(path); 1256 } 1257 1258 static void 1259 process_symlink(u_int32_t id) 1260 { 1261 char *oldpath, *newpath; 1262 int r, status; 1263 1264 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 || 1265 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0) 1266 fatal_fr(r, "parse"); 1267 1268 debug3("request %u: symlink", id); 1269 logit("symlink old \"%s\" new \"%s\"", oldpath, newpath); 1270 /* this will fail if 'newpath' exists */ 1271 r = symlink(oldpath, newpath); 1272 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1273 send_status(id, status); 1274 free(oldpath); 1275 free(newpath); 1276 } 1277 1278 static void 1279 process_extended_posix_rename(u_int32_t id) 1280 { 1281 char *oldpath, *newpath; 1282 int r, status; 1283 1284 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 || 1285 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0) 1286 fatal_fr(r, "parse"); 1287 1288 debug3("request %u: posix-rename", id); 1289 logit("posix-rename old \"%s\" new \"%s\"", oldpath, newpath); 1290 r = rename(oldpath, newpath); 1291 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1292 send_status(id, status); 1293 free(oldpath); 1294 free(newpath); 1295 } 1296 1297 static void 1298 process_extended_statvfs(u_int32_t id) 1299 { 1300 char *path; 1301 struct statvfs st; 1302 int r; 1303 1304 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0) 1305 fatal_fr(r, "parse"); 1306 debug3("request %u: statvfs", id); 1307 logit("statvfs \"%s\"", path); 1308 1309 if (statvfs(path, &st) != 0) 1310 send_status(id, errno_to_portable(errno)); 1311 else 1312 send_statvfs(id, &st); 1313 free(path); 1314 } 1315 1316 static void 1317 process_extended_fstatvfs(u_int32_t id) 1318 { 1319 int r, handle, fd; 1320 struct statvfs st; 1321 1322 if ((r = get_handle(iqueue, &handle)) != 0) 1323 fatal_fr(r, "parse"); 1324 debug("request %u: fstatvfs \"%s\" (handle %u)", 1325 id, handle_to_name(handle), handle); 1326 if ((fd = handle_to_fd(handle)) < 0) { 1327 send_status(id, SSH2_FX_FAILURE); 1328 return; 1329 } 1330 if (fstatvfs(fd, &st) != 0) 1331 send_status(id, errno_to_portable(errno)); 1332 else 1333 send_statvfs(id, &st); 1334 } 1335 1336 static void 1337 process_extended_hardlink(u_int32_t id) 1338 { 1339 char *oldpath, *newpath; 1340 int r, status; 1341 1342 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 || 1343 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0) 1344 fatal_fr(r, "parse"); 1345 1346 debug3("request %u: hardlink", id); 1347 logit("hardlink old \"%s\" new \"%s\"", oldpath, newpath); 1348 r = link(oldpath, newpath); 1349 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1350 send_status(id, status); 1351 free(oldpath); 1352 free(newpath); 1353 } 1354 1355 static void 1356 process_extended_fsync(u_int32_t id) 1357 { 1358 int handle, fd, r, status = SSH2_FX_OP_UNSUPPORTED; 1359 1360 if ((r = get_handle(iqueue, &handle)) != 0) 1361 fatal_fr(r, "parse"); 1362 debug3("request %u: fsync (handle %u)", id, handle); 1363 verbose("fsync \"%s\"", handle_to_name(handle)); 1364 if ((fd = handle_to_fd(handle)) < 0) 1365 status = SSH2_FX_NO_SUCH_FILE; 1366 else if (handle_is_ok(handle, HANDLE_FILE)) { 1367 r = fsync(fd); 1368 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1369 } 1370 send_status(id, status); 1371 } 1372 1373 static void 1374 process_extended_lsetstat(u_int32_t id) 1375 { 1376 Attrib a; 1377 char *name; 1378 int r, status = SSH2_FX_OK; 1379 1380 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 || 1381 (r = decode_attrib(iqueue, &a)) != 0) 1382 fatal_fr(r, "parse"); 1383 1384 debug("request %u: lsetstat name \"%s\"", id, name); 1385 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) { 1386 /* nonsensical for links */ 1387 status = SSH2_FX_BAD_MESSAGE; 1388 goto out; 1389 } 1390 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) { 1391 logit("set \"%s\" mode %04o", name, a.perm); 1392 r = fchmodat(AT_FDCWD, name, 1393 a.perm & 07777, AT_SYMLINK_NOFOLLOW); 1394 if (r == -1) 1395 status = errno_to_portable(errno); 1396 } 1397 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) { 1398 char buf[64]; 1399 time_t t = a.mtime; 1400 1401 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S", 1402 localtime(&t)); 1403 logit("set \"%s\" modtime %s", name, buf); 1404 r = utimensat(AT_FDCWD, name, 1405 attrib_to_ts(&a), AT_SYMLINK_NOFOLLOW); 1406 if (r == -1) 1407 status = errno_to_portable(errno); 1408 } 1409 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) { 1410 logit("set \"%s\" owner %lu group %lu", name, 1411 (u_long)a.uid, (u_long)a.gid); 1412 r = fchownat(AT_FDCWD, name, a.uid, a.gid, 1413 AT_SYMLINK_NOFOLLOW); 1414 if (r == -1) 1415 status = errno_to_portable(errno); 1416 } 1417 out: 1418 send_status(id, status); 1419 free(name); 1420 } 1421 1422 static void 1423 process_extended_limits(u_int32_t id) 1424 { 1425 struct sshbuf *msg; 1426 int r; 1427 uint64_t nfiles = 0; 1428 struct rlimit rlim; 1429 1430 debug("request %u: limits", id); 1431 1432 if (getrlimit(RLIMIT_NOFILE, &rlim) != -1 && rlim.rlim_cur > 5) 1433 nfiles = rlim.rlim_cur - 5; /* stdio(3) + syslog + spare */ 1434 1435 if ((msg = sshbuf_new()) == NULL) 1436 fatal_f("sshbuf_new failed"); 1437 if ((r = sshbuf_put_u8(msg, SSH2_FXP_EXTENDED_REPLY)) != 0 || 1438 (r = sshbuf_put_u32(msg, id)) != 0 || 1439 /* max-packet-length */ 1440 (r = sshbuf_put_u64(msg, SFTP_MAX_MSG_LENGTH)) != 0 || 1441 /* max-read-length */ 1442 (r = sshbuf_put_u64(msg, SFTP_MAX_READ_LENGTH)) != 0 || 1443 /* max-write-length */ 1444 (r = sshbuf_put_u64(msg, SFTP_MAX_MSG_LENGTH - 1024)) != 0 || 1445 /* max-open-handles */ 1446 (r = sshbuf_put_u64(msg, nfiles)) != 0) 1447 fatal_fr(r, "compose"); 1448 send_msg(msg); 1449 sshbuf_free(msg); 1450 } 1451 1452 static void 1453 process_extended(u_int32_t id) 1454 { 1455 char *request; 1456 int i, r; 1457 1458 if ((r = sshbuf_get_cstring(iqueue, &request, NULL)) != 0) 1459 fatal_fr(r, "parse"); 1460 for (i = 0; extended_handlers[i].handler != NULL; i++) { 1461 if (strcmp(request, extended_handlers[i].ext_name) == 0) { 1462 if (!request_permitted(&extended_handlers[i])) 1463 send_status(id, SSH2_FX_PERMISSION_DENIED); 1464 else 1465 extended_handlers[i].handler(id); 1466 break; 1467 } 1468 } 1469 if (extended_handlers[i].handler == NULL) { 1470 error("Unknown extended request \"%.100s\"", request); 1471 send_status(id, SSH2_FX_OP_UNSUPPORTED); /* MUST */ 1472 } 1473 free(request); 1474 } 1475 1476 /* stolen from ssh-agent */ 1477 1478 static void 1479 process(void) 1480 { 1481 u_int msg_len; 1482 u_int buf_len; 1483 u_int consumed; 1484 u_char type; 1485 const u_char *cp; 1486 int i, r; 1487 u_int32_t id; 1488 1489 buf_len = sshbuf_len(iqueue); 1490 if (buf_len < 5) 1491 return; /* Incomplete message. */ 1492 cp = sshbuf_ptr(iqueue); 1493 msg_len = get_u32(cp); 1494 if (msg_len > SFTP_MAX_MSG_LENGTH) { 1495 error("bad message from %s local user %s", 1496 client_addr, pw->pw_name); 1497 sftp_server_cleanup_exit(11); 1498 } 1499 if (buf_len < msg_len + 4) 1500 return; 1501 if ((r = sshbuf_consume(iqueue, 4)) != 0) 1502 fatal_fr(r, "consume"); 1503 buf_len -= 4; 1504 if ((r = sshbuf_get_u8(iqueue, &type)) != 0) 1505 fatal_fr(r, "parse type"); 1506 1507 switch (type) { 1508 case SSH2_FXP_INIT: 1509 process_init(); 1510 init_done = 1; 1511 break; 1512 case SSH2_FXP_EXTENDED: 1513 if (!init_done) 1514 fatal("Received extended request before init"); 1515 if ((r = sshbuf_get_u32(iqueue, &id)) != 0) 1516 fatal_fr(r, "parse extended ID"); 1517 process_extended(id); 1518 break; 1519 default: 1520 if (!init_done) 1521 fatal("Received %u request before init", type); 1522 if ((r = sshbuf_get_u32(iqueue, &id)) != 0) 1523 fatal_fr(r, "parse ID"); 1524 for (i = 0; handlers[i].handler != NULL; i++) { 1525 if (type == handlers[i].type) { 1526 if (!request_permitted(&handlers[i])) { 1527 send_status(id, 1528 SSH2_FX_PERMISSION_DENIED); 1529 } else { 1530 handlers[i].handler(id); 1531 } 1532 break; 1533 } 1534 } 1535 if (handlers[i].handler == NULL) 1536 error("Unknown message %u", type); 1537 } 1538 /* discard the remaining bytes from the current packet */ 1539 if (buf_len < sshbuf_len(iqueue)) { 1540 error("iqueue grew unexpectedly"); 1541 sftp_server_cleanup_exit(255); 1542 } 1543 consumed = buf_len - sshbuf_len(iqueue); 1544 if (msg_len < consumed) { 1545 error("msg_len %u < consumed %u", msg_len, consumed); 1546 sftp_server_cleanup_exit(255); 1547 } 1548 if (msg_len > consumed && 1549 (r = sshbuf_consume(iqueue, msg_len - consumed)) != 0) 1550 fatal_fr(r, "consume"); 1551 } 1552 1553 /* Cleanup handler that logs active handles upon normal exit */ 1554 void 1555 sftp_server_cleanup_exit(int i) 1556 { 1557 if (pw != NULL && client_addr != NULL) { 1558 handle_log_exit(); 1559 logit("session closed for local user %s from [%s]", 1560 pw->pw_name, client_addr); 1561 } 1562 _exit(i); 1563 } 1564 1565 static void 1566 sftp_server_usage(void) 1567 { 1568 extern char *__progname; 1569 1570 fprintf(stderr, 1571 "usage: %s [-ehR] [-d start_directory] [-f log_facility] " 1572 "[-l log_level]\n\t[-P denied_requests] " 1573 "[-p allowed_requests] [-u umask]\n" 1574 " %s -Q protocol_feature\n", 1575 __progname, __progname); 1576 exit(1); 1577 } 1578 1579 int 1580 sftp_server_main(int argc, char **argv, struct passwd *user_pw) 1581 { 1582 fd_set *rset, *wset; 1583 int i, r, in, out, max, ch, skipargs = 0, log_stderr = 0; 1584 ssize_t len, olen, set_size; 1585 SyslogFacility log_facility = SYSLOG_FACILITY_AUTH; 1586 char *cp, *homedir = NULL, uidstr[32], buf[4*4096]; 1587 long mask; 1588 1589 extern char *optarg; 1590 extern char *__progname; 1591 1592 log_init(__progname, log_level, log_facility, log_stderr); 1593 1594 pw = pwcopy(user_pw); 1595 1596 while (!skipargs && (ch = getopt(argc, argv, 1597 "d:f:l:P:p:Q:u:cehR")) != -1) { 1598 switch (ch) { 1599 case 'Q': 1600 if (strcasecmp(optarg, "requests") != 0) { 1601 fprintf(stderr, "Invalid query type\n"); 1602 exit(1); 1603 } 1604 for (i = 0; handlers[i].handler != NULL; i++) 1605 printf("%s\n", handlers[i].name); 1606 for (i = 0; extended_handlers[i].handler != NULL; i++) 1607 printf("%s\n", extended_handlers[i].name); 1608 exit(0); 1609 break; 1610 case 'R': 1611 readonly = 1; 1612 break; 1613 case 'c': 1614 /* 1615 * Ignore all arguments if we are invoked as a 1616 * shell using "sftp-server -c command" 1617 */ 1618 skipargs = 1; 1619 break; 1620 case 'e': 1621 log_stderr = 1; 1622 break; 1623 case 'l': 1624 log_level = log_level_number(optarg); 1625 if (log_level == SYSLOG_LEVEL_NOT_SET) 1626 error("Invalid log level \"%s\"", optarg); 1627 break; 1628 case 'f': 1629 log_facility = log_facility_number(optarg); 1630 if (log_facility == SYSLOG_FACILITY_NOT_SET) 1631 error("Invalid log facility \"%s\"", optarg); 1632 break; 1633 case 'd': 1634 cp = tilde_expand_filename(optarg, user_pw->pw_uid); 1635 snprintf(uidstr, sizeof(uidstr), "%llu", 1636 (unsigned long long)pw->pw_uid); 1637 homedir = percent_expand(cp, "d", user_pw->pw_dir, 1638 "u", user_pw->pw_name, "U", uidstr, (char *)NULL); 1639 free(cp); 1640 break; 1641 case 'p': 1642 if (request_allowlist != NULL) 1643 fatal("Permitted requests already set"); 1644 request_allowlist = xstrdup(optarg); 1645 break; 1646 case 'P': 1647 if (request_denylist != NULL) 1648 fatal("Refused requests already set"); 1649 request_denylist = xstrdup(optarg); 1650 break; 1651 case 'u': 1652 errno = 0; 1653 mask = strtol(optarg, &cp, 8); 1654 if (mask < 0 || mask > 0777 || *cp != '\0' || 1655 cp == optarg || (mask == 0 && errno != 0)) 1656 fatal("Invalid umask \"%s\"", optarg); 1657 (void)umask((mode_t)mask); 1658 break; 1659 case 'h': 1660 default: 1661 sftp_server_usage(); 1662 } 1663 } 1664 1665 log_init(__progname, log_level, log_facility, log_stderr); 1666 1667 if ((cp = getenv("SSH_CONNECTION")) != NULL) { 1668 client_addr = xstrdup(cp); 1669 if ((cp = strchr(client_addr, ' ')) == NULL) { 1670 error("Malformed SSH_CONNECTION variable: \"%s\"", 1671 getenv("SSH_CONNECTION")); 1672 sftp_server_cleanup_exit(255); 1673 } 1674 *cp = '\0'; 1675 } else 1676 client_addr = xstrdup("UNKNOWN"); 1677 1678 logit("session opened for local user %s from [%s]", 1679 pw->pw_name, client_addr); 1680 1681 in = STDIN_FILENO; 1682 out = STDOUT_FILENO; 1683 1684 max = 0; 1685 if (in > max) 1686 max = in; 1687 if (out > max) 1688 max = out; 1689 1690 if ((iqueue = sshbuf_new()) == NULL) 1691 fatal_f("sshbuf_new failed"); 1692 if ((oqueue = sshbuf_new()) == NULL) 1693 fatal_f("sshbuf_new failed"); 1694 1695 rset = xcalloc(howmany(max + 1, NFDBITS), sizeof(fd_mask)); 1696 wset = xcalloc(howmany(max + 1, NFDBITS), sizeof(fd_mask)); 1697 1698 if (homedir != NULL) { 1699 if (chdir(homedir) != 0) { 1700 error("chdir to \"%s\" failed: %s", homedir, 1701 strerror(errno)); 1702 } 1703 } 1704 1705 set_size = howmany(max + 1, NFDBITS) * sizeof(fd_mask); 1706 for (;;) { 1707 memset(rset, 0, set_size); 1708 memset(wset, 0, set_size); 1709 1710 /* 1711 * Ensure that we can read a full buffer and handle 1712 * the worst-case length packet it can generate, 1713 * otherwise apply backpressure by stopping reads. 1714 */ 1715 if ((r = sshbuf_check_reserve(iqueue, sizeof(buf))) == 0 && 1716 (r = sshbuf_check_reserve(oqueue, 1717 SFTP_MAX_MSG_LENGTH)) == 0) 1718 FD_SET(in, rset); 1719 else if (r != SSH_ERR_NO_BUFFER_SPACE) 1720 fatal_fr(r, "reserve"); 1721 1722 olen = sshbuf_len(oqueue); 1723 if (olen > 0) 1724 FD_SET(out, wset); 1725 1726 if (select(max+1, rset, wset, NULL, NULL) == -1) { 1727 if (errno == EINTR) 1728 continue; 1729 error("select: %s", strerror(errno)); 1730 sftp_server_cleanup_exit(2); 1731 } 1732 1733 /* copy stdin to iqueue */ 1734 if (FD_ISSET(in, rset)) { 1735 len = read(in, buf, sizeof buf); 1736 if (len == 0) { 1737 debug("read eof"); 1738 sftp_server_cleanup_exit(0); 1739 } else if (len == -1) { 1740 error("read: %s", strerror(errno)); 1741 sftp_server_cleanup_exit(1); 1742 } else if ((r = sshbuf_put(iqueue, buf, len)) != 0) 1743 fatal_fr(r, "sshbuf_put"); 1744 } 1745 /* send oqueue to stdout */ 1746 if (FD_ISSET(out, wset)) { 1747 len = write(out, sshbuf_ptr(oqueue), olen); 1748 if (len == -1) { 1749 error("write: %s", strerror(errno)); 1750 sftp_server_cleanup_exit(1); 1751 } else if ((r = sshbuf_consume(oqueue, len)) != 0) 1752 fatal_fr(r, "consume"); 1753 } 1754 1755 /* 1756 * Process requests from client if we can fit the results 1757 * into the output buffer, otherwise stop processing input 1758 * and let the output queue drain. 1759 */ 1760 r = sshbuf_check_reserve(oqueue, SFTP_MAX_MSG_LENGTH); 1761 if (r == 0) 1762 process(); 1763 else if (r != SSH_ERR_NO_BUFFER_SPACE) 1764 fatal_fr(r, "reserve"); 1765 } 1766 } 1767