1 /* $OpenBSD: sftp-server.c,v 1.107 2015/08/20 22:32:42 deraadt Exp $ */ 2 /* 3 * Copyright (c) 2000-2004 Markus Friedl. All rights reserved. 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 #include "includes.h" 19 20 #include <sys/param.h> /* MIN */ 21 #include <sys/types.h> 22 #include <sys/stat.h> 23 #ifdef HAVE_SYS_TIME_H 24 # include <sys/time.h> 25 #endif 26 #ifdef HAVE_SYS_MOUNT_H 27 #include <sys/mount.h> 28 #endif 29 #ifdef HAVE_SYS_STATVFS_H 30 #include <sys/statvfs.h> 31 #endif 32 #ifdef HAVE_SYS_PRCTL_H 33 #include <sys/prctl.h> 34 #endif 35 36 #include <dirent.h> 37 #include <errno.h> 38 #include <fcntl.h> 39 #include <pwd.h> 40 #include <stdlib.h> 41 #include <stdio.h> 42 #include <string.h> 43 #include <time.h> 44 #include <unistd.h> 45 #include <stdarg.h> 46 47 #include "xmalloc.h" 48 #include "sshbuf.h" 49 #include "ssherr.h" 50 #include "log.h" 51 #include "misc.h" 52 #include "match.h" 53 #include "uidswap.h" 54 55 #include "sftp.h" 56 #include "sftp-common.h" 57 58 /* Our verbosity */ 59 static LogLevel log_level = SYSLOG_LEVEL_ERROR; 60 61 /* Our client */ 62 static struct passwd *pw = NULL; 63 static char *client_addr = NULL; 64 65 /* input and output queue */ 66 struct sshbuf *iqueue; 67 struct sshbuf *oqueue; 68 69 /* Version of client */ 70 static u_int version; 71 72 /* SSH2_FXP_INIT received */ 73 static int init_done; 74 75 /* Disable writes */ 76 static int readonly; 77 78 /* Requests that are allowed/denied */ 79 static char *request_whitelist, *request_blacklist; 80 81 /* portable attributes, etc. */ 82 typedef struct Stat Stat; 83 84 struct Stat { 85 char *name; 86 char *long_name; 87 Attrib attrib; 88 }; 89 90 /* Packet handlers */ 91 static void process_open(u_int32_t id); 92 static void process_close(u_int32_t id); 93 static void process_read(u_int32_t id); 94 static void process_write(u_int32_t id); 95 static void process_stat(u_int32_t id); 96 static void process_lstat(u_int32_t id); 97 static void process_fstat(u_int32_t id); 98 static void process_setstat(u_int32_t id); 99 static void process_fsetstat(u_int32_t id); 100 static void process_opendir(u_int32_t id); 101 static void process_readdir(u_int32_t id); 102 static void process_remove(u_int32_t id); 103 static void process_mkdir(u_int32_t id); 104 static void process_rmdir(u_int32_t id); 105 static void process_realpath(u_int32_t id); 106 static void process_rename(u_int32_t id); 107 static void process_readlink(u_int32_t id); 108 static void process_symlink(u_int32_t id); 109 static void process_extended_posix_rename(u_int32_t id); 110 static void process_extended_statvfs(u_int32_t id); 111 static void process_extended_fstatvfs(u_int32_t id); 112 static void process_extended_hardlink(u_int32_t id); 113 static void process_extended_fsync(u_int32_t id); 114 static void process_extended(u_int32_t id); 115 116 struct sftp_handler { 117 const char *name; /* user-visible name for fine-grained perms */ 118 const char *ext_name; /* extended request name */ 119 u_int type; /* packet type, for non extended packets */ 120 void (*handler)(u_int32_t); 121 int does_write; /* if nonzero, banned for readonly mode */ 122 }; 123 124 struct sftp_handler handlers[] = { 125 /* NB. SSH2_FXP_OPEN does the readonly check in the handler itself */ 126 { "open", NULL, SSH2_FXP_OPEN, process_open, 0 }, 127 { "close", NULL, SSH2_FXP_CLOSE, process_close, 0 }, 128 { "read", NULL, SSH2_FXP_READ, process_read, 0 }, 129 { "write", NULL, SSH2_FXP_WRITE, process_write, 1 }, 130 { "lstat", NULL, SSH2_FXP_LSTAT, process_lstat, 0 }, 131 { "fstat", NULL, SSH2_FXP_FSTAT, process_fstat, 0 }, 132 { "setstat", NULL, SSH2_FXP_SETSTAT, process_setstat, 1 }, 133 { "fsetstat", NULL, SSH2_FXP_FSETSTAT, process_fsetstat, 1 }, 134 { "opendir", NULL, SSH2_FXP_OPENDIR, process_opendir, 0 }, 135 { "readdir", NULL, SSH2_FXP_READDIR, process_readdir, 0 }, 136 { "remove", NULL, SSH2_FXP_REMOVE, process_remove, 1 }, 137 { "mkdir", NULL, SSH2_FXP_MKDIR, process_mkdir, 1 }, 138 { "rmdir", NULL, SSH2_FXP_RMDIR, process_rmdir, 1 }, 139 { "realpath", NULL, SSH2_FXP_REALPATH, process_realpath, 0 }, 140 { "stat", NULL, SSH2_FXP_STAT, process_stat, 0 }, 141 { "rename", NULL, SSH2_FXP_RENAME, process_rename, 1 }, 142 { "readlink", NULL, SSH2_FXP_READLINK, process_readlink, 0 }, 143 { "symlink", NULL, SSH2_FXP_SYMLINK, process_symlink, 1 }, 144 { NULL, NULL, 0, NULL, 0 } 145 }; 146 147 /* SSH2_FXP_EXTENDED submessages */ 148 struct sftp_handler extended_handlers[] = { 149 { "posix-rename", "posix-rename (at) openssh.com", 0, 150 process_extended_posix_rename, 1 }, 151 { "statvfs", "statvfs (at) openssh.com", 0, process_extended_statvfs, 0 }, 152 { "fstatvfs", "fstatvfs (at) openssh.com", 0, process_extended_fstatvfs, 0 }, 153 { "hardlink", "hardlink (at) openssh.com", 0, process_extended_hardlink, 1 }, 154 { "fsync", "fsync (at) openssh.com", 0, process_extended_fsync, 1 }, 155 { NULL, NULL, 0, NULL, 0 } 156 }; 157 158 static int 159 request_permitted(struct sftp_handler *h) 160 { 161 char *result; 162 163 if (readonly && h->does_write) { 164 verbose("Refusing %s request in read-only mode", h->name); 165 return 0; 166 } 167 if (request_blacklist != NULL && 168 ((result = match_list(h->name, request_blacklist, NULL))) != NULL) { 169 free(result); 170 verbose("Refusing blacklisted %s request", h->name); 171 return 0; 172 } 173 if (request_whitelist != NULL && 174 ((result = match_list(h->name, request_whitelist, NULL))) != NULL) { 175 free(result); 176 debug2("Permitting whitelisted %s request", h->name); 177 return 1; 178 } 179 if (request_whitelist != NULL) { 180 verbose("Refusing non-whitelisted %s request", h->name); 181 return 0; 182 } 183 return 1; 184 } 185 186 static int 187 errno_to_portable(int unixerrno) 188 { 189 int ret = 0; 190 191 switch (unixerrno) { 192 case 0: 193 ret = SSH2_FX_OK; 194 break; 195 case ENOENT: 196 case ENOTDIR: 197 case EBADF: 198 case ELOOP: 199 ret = SSH2_FX_NO_SUCH_FILE; 200 break; 201 case EPERM: 202 case EACCES: 203 case EFAULT: 204 ret = SSH2_FX_PERMISSION_DENIED; 205 break; 206 case ENAMETOOLONG: 207 case EINVAL: 208 ret = SSH2_FX_BAD_MESSAGE; 209 break; 210 case ENOSYS: 211 ret = SSH2_FX_OP_UNSUPPORTED; 212 break; 213 default: 214 ret = SSH2_FX_FAILURE; 215 break; 216 } 217 return ret; 218 } 219 220 static int 221 flags_from_portable(int pflags) 222 { 223 int flags = 0; 224 225 if ((pflags & SSH2_FXF_READ) && 226 (pflags & SSH2_FXF_WRITE)) { 227 flags = O_RDWR; 228 } else if (pflags & SSH2_FXF_READ) { 229 flags = O_RDONLY; 230 } else if (pflags & SSH2_FXF_WRITE) { 231 flags = O_WRONLY; 232 } 233 if (pflags & SSH2_FXF_APPEND) 234 flags |= O_APPEND; 235 if (pflags & SSH2_FXF_CREAT) 236 flags |= O_CREAT; 237 if (pflags & SSH2_FXF_TRUNC) 238 flags |= O_TRUNC; 239 if (pflags & SSH2_FXF_EXCL) 240 flags |= O_EXCL; 241 return flags; 242 } 243 244 static const char * 245 string_from_portable(int pflags) 246 { 247 static char ret[128]; 248 249 *ret = '\0'; 250 251 #define PAPPEND(str) { \ 252 if (*ret != '\0') \ 253 strlcat(ret, ",", sizeof(ret)); \ 254 strlcat(ret, str, sizeof(ret)); \ 255 } 256 257 if (pflags & SSH2_FXF_READ) 258 PAPPEND("READ") 259 if (pflags & SSH2_FXF_WRITE) 260 PAPPEND("WRITE") 261 if (pflags & SSH2_FXF_APPEND) 262 PAPPEND("APPEND") 263 if (pflags & SSH2_FXF_CREAT) 264 PAPPEND("CREATE") 265 if (pflags & SSH2_FXF_TRUNC) 266 PAPPEND("TRUNCATE") 267 if (pflags & SSH2_FXF_EXCL) 268 PAPPEND("EXCL") 269 270 return ret; 271 } 272 273 /* handle handles */ 274 275 typedef struct Handle Handle; 276 struct Handle { 277 int use; 278 DIR *dirp; 279 int fd; 280 int flags; 281 char *name; 282 u_int64_t bytes_read, bytes_write; 283 int next_unused; 284 }; 285 286 enum { 287 HANDLE_UNUSED, 288 HANDLE_DIR, 289 HANDLE_FILE 290 }; 291 292 Handle *handles = NULL; 293 u_int num_handles = 0; 294 int first_unused_handle = -1; 295 296 static void handle_unused(int i) 297 { 298 handles[i].use = HANDLE_UNUSED; 299 handles[i].next_unused = first_unused_handle; 300 first_unused_handle = i; 301 } 302 303 static int 304 handle_new(int use, const char *name, int fd, int flags, DIR *dirp) 305 { 306 int i; 307 308 if (first_unused_handle == -1) { 309 if (num_handles + 1 <= num_handles) 310 return -1; 311 num_handles++; 312 handles = xreallocarray(handles, num_handles, sizeof(Handle)); 313 handle_unused(num_handles - 1); 314 } 315 316 i = first_unused_handle; 317 first_unused_handle = handles[i].next_unused; 318 319 handles[i].use = use; 320 handles[i].dirp = dirp; 321 handles[i].fd = fd; 322 handles[i].flags = flags; 323 handles[i].name = xstrdup(name); 324 handles[i].bytes_read = handles[i].bytes_write = 0; 325 326 return i; 327 } 328 329 static int 330 handle_is_ok(int i, int type) 331 { 332 return i >= 0 && (u_int)i < num_handles && handles[i].use == type; 333 } 334 335 static int 336 handle_to_string(int handle, u_char **stringp, int *hlenp) 337 { 338 if (stringp == NULL || hlenp == NULL) 339 return -1; 340 *stringp = xmalloc(sizeof(int32_t)); 341 put_u32(*stringp, handle); 342 *hlenp = sizeof(int32_t); 343 return 0; 344 } 345 346 static int 347 handle_from_string(const u_char *handle, u_int hlen) 348 { 349 int val; 350 351 if (hlen != sizeof(int32_t)) 352 return -1; 353 val = get_u32(handle); 354 if (handle_is_ok(val, HANDLE_FILE) || 355 handle_is_ok(val, HANDLE_DIR)) 356 return val; 357 return -1; 358 } 359 360 static char * 361 handle_to_name(int handle) 362 { 363 if (handle_is_ok(handle, HANDLE_DIR)|| 364 handle_is_ok(handle, HANDLE_FILE)) 365 return handles[handle].name; 366 return NULL; 367 } 368 369 static DIR * 370 handle_to_dir(int handle) 371 { 372 if (handle_is_ok(handle, HANDLE_DIR)) 373 return handles[handle].dirp; 374 return NULL; 375 } 376 377 static int 378 handle_to_fd(int handle) 379 { 380 if (handle_is_ok(handle, HANDLE_FILE)) 381 return handles[handle].fd; 382 return -1; 383 } 384 385 static int 386 handle_to_flags(int handle) 387 { 388 if (handle_is_ok(handle, HANDLE_FILE)) 389 return handles[handle].flags; 390 return 0; 391 } 392 393 static void 394 handle_update_read(int handle, ssize_t bytes) 395 { 396 if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0) 397 handles[handle].bytes_read += bytes; 398 } 399 400 static void 401 handle_update_write(int handle, ssize_t bytes) 402 { 403 if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0) 404 handles[handle].bytes_write += bytes; 405 } 406 407 static u_int64_t 408 handle_bytes_read(int handle) 409 { 410 if (handle_is_ok(handle, HANDLE_FILE)) 411 return (handles[handle].bytes_read); 412 return 0; 413 } 414 415 static u_int64_t 416 handle_bytes_write(int handle) 417 { 418 if (handle_is_ok(handle, HANDLE_FILE)) 419 return (handles[handle].bytes_write); 420 return 0; 421 } 422 423 static int 424 handle_close(int handle) 425 { 426 int ret = -1; 427 428 if (handle_is_ok(handle, HANDLE_FILE)) { 429 ret = close(handles[handle].fd); 430 free(handles[handle].name); 431 handle_unused(handle); 432 } else if (handle_is_ok(handle, HANDLE_DIR)) { 433 ret = closedir(handles[handle].dirp); 434 free(handles[handle].name); 435 handle_unused(handle); 436 } else { 437 errno = ENOENT; 438 } 439 return ret; 440 } 441 442 static void 443 handle_log_close(int handle, char *emsg) 444 { 445 if (handle_is_ok(handle, HANDLE_FILE)) { 446 logit("%s%sclose \"%s\" bytes read %llu written %llu", 447 emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ", 448 handle_to_name(handle), 449 (unsigned long long)handle_bytes_read(handle), 450 (unsigned long long)handle_bytes_write(handle)); 451 } else { 452 logit("%s%sclosedir \"%s\"", 453 emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ", 454 handle_to_name(handle)); 455 } 456 } 457 458 static void 459 handle_log_exit(void) 460 { 461 u_int i; 462 463 for (i = 0; i < num_handles; i++) 464 if (handles[i].use != HANDLE_UNUSED) 465 handle_log_close(i, "forced"); 466 } 467 468 static int 469 get_handle(struct sshbuf *queue, int *hp) 470 { 471 u_char *handle; 472 int r; 473 size_t hlen; 474 475 *hp = -1; 476 if ((r = sshbuf_get_string(queue, &handle, &hlen)) != 0) 477 return r; 478 if (hlen < 256) 479 *hp = handle_from_string(handle, hlen); 480 free(handle); 481 return 0; 482 } 483 484 /* send replies */ 485 486 static void 487 send_msg(struct sshbuf *m) 488 { 489 int r; 490 491 if ((r = sshbuf_put_stringb(oqueue, m)) != 0) 492 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 493 sshbuf_reset(m); 494 } 495 496 static const char * 497 status_to_message(u_int32_t status) 498 { 499 const char *status_messages[] = { 500 "Success", /* SSH_FX_OK */ 501 "End of file", /* SSH_FX_EOF */ 502 "No such file", /* SSH_FX_NO_SUCH_FILE */ 503 "Permission denied", /* SSH_FX_PERMISSION_DENIED */ 504 "Failure", /* SSH_FX_FAILURE */ 505 "Bad message", /* SSH_FX_BAD_MESSAGE */ 506 "No connection", /* SSH_FX_NO_CONNECTION */ 507 "Connection lost", /* SSH_FX_CONNECTION_LOST */ 508 "Operation unsupported", /* SSH_FX_OP_UNSUPPORTED */ 509 "Unknown error" /* Others */ 510 }; 511 return (status_messages[MIN(status,SSH2_FX_MAX)]); 512 } 513 514 static void 515 send_status(u_int32_t id, u_int32_t status) 516 { 517 struct sshbuf *msg; 518 int r; 519 520 debug3("request %u: sent status %u", id, status); 521 if (log_level > SYSLOG_LEVEL_VERBOSE || 522 (status != SSH2_FX_OK && status != SSH2_FX_EOF)) 523 logit("sent status %s", status_to_message(status)); 524 if ((msg = sshbuf_new()) == NULL) 525 fatal("%s: sshbuf_new failed", __func__); 526 if ((r = sshbuf_put_u8(msg, SSH2_FXP_STATUS)) != 0 || 527 (r = sshbuf_put_u32(msg, id)) != 0 || 528 (r = sshbuf_put_u32(msg, status)) != 0) 529 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 530 if (version >= 3) { 531 if ((r = sshbuf_put_cstring(msg, 532 status_to_message(status))) != 0 || 533 (r = sshbuf_put_cstring(msg, "")) != 0) 534 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 535 } 536 send_msg(msg); 537 sshbuf_free(msg); 538 } 539 static void 540 send_data_or_handle(char type, u_int32_t id, const u_char *data, int dlen) 541 { 542 struct sshbuf *msg; 543 int r; 544 545 if ((msg = sshbuf_new()) == NULL) 546 fatal("%s: sshbuf_new failed", __func__); 547 if ((r = sshbuf_put_u8(msg, type)) != 0 || 548 (r = sshbuf_put_u32(msg, id)) != 0 || 549 (r = sshbuf_put_string(msg, data, dlen)) != 0) 550 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 551 send_msg(msg); 552 sshbuf_free(msg); 553 } 554 555 static void 556 send_data(u_int32_t id, const u_char *data, int dlen) 557 { 558 debug("request %u: sent data len %d", id, dlen); 559 send_data_or_handle(SSH2_FXP_DATA, id, data, dlen); 560 } 561 562 static void 563 send_handle(u_int32_t id, int handle) 564 { 565 u_char *string; 566 int hlen; 567 568 handle_to_string(handle, &string, &hlen); 569 debug("request %u: sent handle handle %d", id, handle); 570 send_data_or_handle(SSH2_FXP_HANDLE, id, string, hlen); 571 free(string); 572 } 573 574 static void 575 send_names(u_int32_t id, int count, const Stat *stats) 576 { 577 struct sshbuf *msg; 578 int i, r; 579 580 if ((msg = sshbuf_new()) == NULL) 581 fatal("%s: sshbuf_new failed", __func__); 582 if ((r = sshbuf_put_u8(msg, SSH2_FXP_NAME)) != 0 || 583 (r = sshbuf_put_u32(msg, id)) != 0 || 584 (r = sshbuf_put_u32(msg, count)) != 0) 585 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 586 debug("request %u: sent names count %d", id, count); 587 for (i = 0; i < count; i++) { 588 if ((r = sshbuf_put_cstring(msg, stats[i].name)) != 0 || 589 (r = sshbuf_put_cstring(msg, stats[i].long_name)) != 0 || 590 (r = encode_attrib(msg, &stats[i].attrib)) != 0) 591 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 592 } 593 send_msg(msg); 594 sshbuf_free(msg); 595 } 596 597 static void 598 send_attrib(u_int32_t id, const Attrib *a) 599 { 600 struct sshbuf *msg; 601 int r; 602 603 debug("request %u: sent attrib have 0x%x", id, a->flags); 604 if ((msg = sshbuf_new()) == NULL) 605 fatal("%s: sshbuf_new failed", __func__); 606 if ((r = sshbuf_put_u8(msg, SSH2_FXP_ATTRS)) != 0 || 607 (r = sshbuf_put_u32(msg, id)) != 0 || 608 (r = encode_attrib(msg, a)) != 0) 609 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 610 send_msg(msg); 611 sshbuf_free(msg); 612 } 613 614 static void 615 send_statvfs(u_int32_t id, struct statvfs *st) 616 { 617 struct sshbuf *msg; 618 u_int64_t flag; 619 int r; 620 621 flag = (st->f_flag & ST_RDONLY) ? SSH2_FXE_STATVFS_ST_RDONLY : 0; 622 flag |= (st->f_flag & ST_NOSUID) ? SSH2_FXE_STATVFS_ST_NOSUID : 0; 623 624 if ((msg = sshbuf_new()) == NULL) 625 fatal("%s: sshbuf_new failed", __func__); 626 if ((r = sshbuf_put_u8(msg, SSH2_FXP_EXTENDED_REPLY)) != 0 || 627 (r = sshbuf_put_u32(msg, id)) != 0 || 628 (r = sshbuf_put_u64(msg, st->f_bsize)) != 0 || 629 (r = sshbuf_put_u64(msg, st->f_frsize)) != 0 || 630 (r = sshbuf_put_u64(msg, st->f_blocks)) != 0 || 631 (r = sshbuf_put_u64(msg, st->f_bfree)) != 0 || 632 (r = sshbuf_put_u64(msg, st->f_bavail)) != 0 || 633 (r = sshbuf_put_u64(msg, st->f_files)) != 0 || 634 (r = sshbuf_put_u64(msg, st->f_ffree)) != 0 || 635 (r = sshbuf_put_u64(msg, st->f_favail)) != 0 || 636 (r = sshbuf_put_u64(msg, FSID_TO_ULONG(st->f_fsid))) != 0 || 637 (r = sshbuf_put_u64(msg, flag)) != 0 || 638 (r = sshbuf_put_u64(msg, st->f_namemax)) != 0) 639 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 640 send_msg(msg); 641 sshbuf_free(msg); 642 } 643 644 /* parse incoming */ 645 646 static void 647 process_init(void) 648 { 649 struct sshbuf *msg; 650 int r; 651 652 if ((r = sshbuf_get_u32(iqueue, &version)) != 0) 653 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 654 verbose("received client version %u", version); 655 if ((msg = sshbuf_new()) == NULL) 656 fatal("%s: sshbuf_new failed", __func__); 657 if ((r = sshbuf_put_u8(msg, SSH2_FXP_VERSION)) != 0 || 658 (r = sshbuf_put_u32(msg, SSH2_FILEXFER_VERSION)) != 0 || 659 /* POSIX rename extension */ 660 (r = sshbuf_put_cstring(msg, "posix-rename (at) openssh.com")) != 0 || 661 (r = sshbuf_put_cstring(msg, "1")) != 0 || /* version */ 662 /* statvfs extension */ 663 (r = sshbuf_put_cstring(msg, "statvfs (at) openssh.com")) != 0 || 664 (r = sshbuf_put_cstring(msg, "2")) != 0 || /* version */ 665 /* fstatvfs extension */ 666 (r = sshbuf_put_cstring(msg, "fstatvfs (at) openssh.com")) != 0 || 667 (r = sshbuf_put_cstring(msg, "2")) != 0 || /* version */ 668 /* hardlink extension */ 669 (r = sshbuf_put_cstring(msg, "hardlink (at) openssh.com")) != 0 || 670 (r = sshbuf_put_cstring(msg, "1")) != 0 || /* version */ 671 /* fsync extension */ 672 (r = sshbuf_put_cstring(msg, "fsync (at) openssh.com")) != 0 || 673 (r = sshbuf_put_cstring(msg, "1")) != 0) /* version */ 674 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 675 send_msg(msg); 676 sshbuf_free(msg); 677 } 678 679 static void 680 process_open(u_int32_t id) 681 { 682 u_int32_t pflags; 683 Attrib a; 684 char *name; 685 int r, handle, fd, flags, mode, status = SSH2_FX_FAILURE; 686 687 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 || 688 (r = sshbuf_get_u32(iqueue, &pflags)) != 0 || /* portable flags */ 689 (r = decode_attrib(iqueue, &a)) != 0) 690 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 691 692 debug3("request %u: open flags %d", id, pflags); 693 flags = flags_from_portable(pflags); 694 mode = (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? a.perm : 0666; 695 logit("open \"%s\" flags %s mode 0%o", 696 name, string_from_portable(pflags), mode); 697 if (readonly && 698 ((flags & O_ACCMODE) == O_WRONLY || 699 (flags & O_ACCMODE) == O_RDWR)) { 700 verbose("Refusing open request in read-only mode"); 701 status = SSH2_FX_PERMISSION_DENIED; 702 } else { 703 fd = open(name, flags, mode); 704 if (fd < 0) { 705 status = errno_to_portable(errno); 706 } else { 707 handle = handle_new(HANDLE_FILE, name, fd, flags, NULL); 708 if (handle < 0) { 709 close(fd); 710 } else { 711 send_handle(id, handle); 712 status = SSH2_FX_OK; 713 } 714 } 715 } 716 if (status != SSH2_FX_OK) 717 send_status(id, status); 718 free(name); 719 } 720 721 static void 722 process_close(u_int32_t id) 723 { 724 int r, handle, ret, status = SSH2_FX_FAILURE; 725 726 if ((r = get_handle(iqueue, &handle)) != 0) 727 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 728 729 debug3("request %u: close handle %u", id, handle); 730 handle_log_close(handle, NULL); 731 ret = handle_close(handle); 732 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 733 send_status(id, status); 734 } 735 736 static void 737 process_read(u_int32_t id) 738 { 739 u_char buf[64*1024]; 740 u_int32_t len; 741 int r, handle, fd, ret, status = SSH2_FX_FAILURE; 742 u_int64_t off; 743 744 if ((r = get_handle(iqueue, &handle)) != 0 || 745 (r = sshbuf_get_u64(iqueue, &off)) != 0 || 746 (r = sshbuf_get_u32(iqueue, &len)) != 0) 747 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 748 749 debug("request %u: read \"%s\" (handle %d) off %llu len %d", 750 id, handle_to_name(handle), handle, (unsigned long long)off, len); 751 if (len > sizeof buf) { 752 len = sizeof buf; 753 debug2("read change len %d", len); 754 } 755 fd = handle_to_fd(handle); 756 if (fd >= 0) { 757 if (lseek(fd, off, SEEK_SET) < 0) { 758 error("process_read: seek failed"); 759 status = errno_to_portable(errno); 760 } else { 761 ret = read(fd, buf, len); 762 if (ret < 0) { 763 status = errno_to_portable(errno); 764 } else if (ret == 0) { 765 status = SSH2_FX_EOF; 766 } else { 767 send_data(id, buf, ret); 768 status = SSH2_FX_OK; 769 handle_update_read(handle, ret); 770 } 771 } 772 } 773 if (status != SSH2_FX_OK) 774 send_status(id, status); 775 } 776 777 static void 778 process_write(u_int32_t id) 779 { 780 u_int64_t off; 781 size_t len; 782 int r, handle, fd, ret, status; 783 u_char *data; 784 785 if ((r = get_handle(iqueue, &handle)) != 0 || 786 (r = sshbuf_get_u64(iqueue, &off)) != 0 || 787 (r = sshbuf_get_string(iqueue, &data, &len)) != 0) 788 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 789 790 debug("request %u: write \"%s\" (handle %d) off %llu len %zu", 791 id, handle_to_name(handle), handle, (unsigned long long)off, len); 792 fd = handle_to_fd(handle); 793 794 if (fd < 0) 795 status = SSH2_FX_FAILURE; 796 else { 797 if (!(handle_to_flags(handle) & O_APPEND) && 798 lseek(fd, off, SEEK_SET) < 0) { 799 status = errno_to_portable(errno); 800 error("process_write: seek failed"); 801 } else { 802 /* XXX ATOMICIO ? */ 803 ret = write(fd, data, len); 804 if (ret < 0) { 805 error("process_write: write failed"); 806 status = errno_to_portable(errno); 807 } else if ((size_t)ret == len) { 808 status = SSH2_FX_OK; 809 handle_update_write(handle, ret); 810 } else { 811 debug2("nothing at all written"); 812 status = SSH2_FX_FAILURE; 813 } 814 } 815 } 816 send_status(id, status); 817 free(data); 818 } 819 820 static void 821 process_do_stat(u_int32_t id, int do_lstat) 822 { 823 Attrib a; 824 struct stat st; 825 char *name; 826 int r, status = SSH2_FX_FAILURE; 827 828 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0) 829 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 830 831 debug3("request %u: %sstat", id, do_lstat ? "l" : ""); 832 verbose("%sstat name \"%s\"", do_lstat ? "l" : "", name); 833 r = do_lstat ? lstat(name, &st) : stat(name, &st); 834 if (r < 0) { 835 status = errno_to_portable(errno); 836 } else { 837 stat_to_attrib(&st, &a); 838 send_attrib(id, &a); 839 status = SSH2_FX_OK; 840 } 841 if (status != SSH2_FX_OK) 842 send_status(id, status); 843 free(name); 844 } 845 846 static void 847 process_stat(u_int32_t id) 848 { 849 process_do_stat(id, 0); 850 } 851 852 static void 853 process_lstat(u_int32_t id) 854 { 855 process_do_stat(id, 1); 856 } 857 858 static void 859 process_fstat(u_int32_t id) 860 { 861 Attrib a; 862 struct stat st; 863 int fd, r, handle, status = SSH2_FX_FAILURE; 864 865 if ((r = get_handle(iqueue, &handle)) != 0) 866 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 867 debug("request %u: fstat \"%s\" (handle %u)", 868 id, handle_to_name(handle), handle); 869 fd = handle_to_fd(handle); 870 if (fd >= 0) { 871 r = fstat(fd, &st); 872 if (r < 0) { 873 status = errno_to_portable(errno); 874 } else { 875 stat_to_attrib(&st, &a); 876 send_attrib(id, &a); 877 status = SSH2_FX_OK; 878 } 879 } 880 if (status != SSH2_FX_OK) 881 send_status(id, status); 882 } 883 884 static struct timeval * 885 attrib_to_tv(const Attrib *a) 886 { 887 static struct timeval tv[2]; 888 889 tv[0].tv_sec = a->atime; 890 tv[0].tv_usec = 0; 891 tv[1].tv_sec = a->mtime; 892 tv[1].tv_usec = 0; 893 return tv; 894 } 895 896 static void 897 process_setstat(u_int32_t id) 898 { 899 Attrib a; 900 char *name; 901 int r, status = SSH2_FX_OK; 902 903 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 || 904 (r = decode_attrib(iqueue, &a)) != 0) 905 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 906 907 debug("request %u: setstat name \"%s\"", id, name); 908 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) { 909 logit("set \"%s\" size %llu", 910 name, (unsigned long long)a.size); 911 r = truncate(name, a.size); 912 if (r == -1) 913 status = errno_to_portable(errno); 914 } 915 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) { 916 logit("set \"%s\" mode %04o", name, a.perm); 917 r = chmod(name, a.perm & 07777); 918 if (r == -1) 919 status = errno_to_portable(errno); 920 } 921 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) { 922 char buf[64]; 923 time_t t = a.mtime; 924 925 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S", 926 localtime(&t)); 927 logit("set \"%s\" modtime %s", name, buf); 928 r = utimes(name, attrib_to_tv(&a)); 929 if (r == -1) 930 status = errno_to_portable(errno); 931 } 932 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) { 933 logit("set \"%s\" owner %lu group %lu", name, 934 (u_long)a.uid, (u_long)a.gid); 935 r = chown(name, a.uid, a.gid); 936 if (r == -1) 937 status = errno_to_portable(errno); 938 } 939 send_status(id, status); 940 free(name); 941 } 942 943 static void 944 process_fsetstat(u_int32_t id) 945 { 946 Attrib a; 947 int handle, fd, r; 948 int status = SSH2_FX_OK; 949 950 if ((r = get_handle(iqueue, &handle)) != 0 || 951 (r = decode_attrib(iqueue, &a)) != 0) 952 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 953 954 debug("request %u: fsetstat handle %d", id, handle); 955 fd = handle_to_fd(handle); 956 if (fd < 0) 957 status = SSH2_FX_FAILURE; 958 else { 959 char *name = handle_to_name(handle); 960 961 if (a.flags & SSH2_FILEXFER_ATTR_SIZE) { 962 logit("set \"%s\" size %llu", 963 name, (unsigned long long)a.size); 964 r = ftruncate(fd, a.size); 965 if (r == -1) 966 status = errno_to_portable(errno); 967 } 968 if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) { 969 logit("set \"%s\" mode %04o", name, a.perm); 970 #ifdef HAVE_FCHMOD 971 r = fchmod(fd, a.perm & 07777); 972 #else 973 r = chmod(name, a.perm & 07777); 974 #endif 975 if (r == -1) 976 status = errno_to_portable(errno); 977 } 978 if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) { 979 char buf[64]; 980 time_t t = a.mtime; 981 982 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S", 983 localtime(&t)); 984 logit("set \"%s\" modtime %s", name, buf); 985 #ifdef HAVE_FUTIMES 986 r = futimes(fd, attrib_to_tv(&a)); 987 #else 988 r = utimes(name, attrib_to_tv(&a)); 989 #endif 990 if (r == -1) 991 status = errno_to_portable(errno); 992 } 993 if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) { 994 logit("set \"%s\" owner %lu group %lu", name, 995 (u_long)a.uid, (u_long)a.gid); 996 #ifdef HAVE_FCHOWN 997 r = fchown(fd, a.uid, a.gid); 998 #else 999 r = chown(name, a.uid, a.gid); 1000 #endif 1001 if (r == -1) 1002 status = errno_to_portable(errno); 1003 } 1004 } 1005 send_status(id, status); 1006 } 1007 1008 static void 1009 process_opendir(u_int32_t id) 1010 { 1011 DIR *dirp = NULL; 1012 char *path; 1013 int r, handle, status = SSH2_FX_FAILURE; 1014 1015 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0) 1016 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1017 1018 debug3("request %u: opendir", id); 1019 logit("opendir \"%s\"", path); 1020 dirp = opendir(path); 1021 if (dirp == NULL) { 1022 status = errno_to_portable(errno); 1023 } else { 1024 handle = handle_new(HANDLE_DIR, path, 0, 0, dirp); 1025 if (handle < 0) { 1026 closedir(dirp); 1027 } else { 1028 send_handle(id, handle); 1029 status = SSH2_FX_OK; 1030 } 1031 1032 } 1033 if (status != SSH2_FX_OK) 1034 send_status(id, status); 1035 free(path); 1036 } 1037 1038 static void 1039 process_readdir(u_int32_t id) 1040 { 1041 DIR *dirp; 1042 struct dirent *dp; 1043 char *path; 1044 int r, handle; 1045 1046 if ((r = get_handle(iqueue, &handle)) != 0) 1047 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1048 1049 debug("request %u: readdir \"%s\" (handle %d)", id, 1050 handle_to_name(handle), handle); 1051 dirp = handle_to_dir(handle); 1052 path = handle_to_name(handle); 1053 if (dirp == NULL || path == NULL) { 1054 send_status(id, SSH2_FX_FAILURE); 1055 } else { 1056 struct stat st; 1057 char pathname[PATH_MAX]; 1058 Stat *stats; 1059 int nstats = 10, count = 0, i; 1060 1061 stats = xcalloc(nstats, sizeof(Stat)); 1062 while ((dp = readdir(dirp)) != NULL) { 1063 if (count >= nstats) { 1064 nstats *= 2; 1065 stats = xreallocarray(stats, nstats, sizeof(Stat)); 1066 } 1067 /* XXX OVERFLOW ? */ 1068 snprintf(pathname, sizeof pathname, "%s%s%s", path, 1069 strcmp(path, "/") ? "/" : "", dp->d_name); 1070 if (lstat(pathname, &st) < 0) 1071 continue; 1072 stat_to_attrib(&st, &(stats[count].attrib)); 1073 stats[count].name = xstrdup(dp->d_name); 1074 stats[count].long_name = ls_file(dp->d_name, &st, 0, 0); 1075 count++; 1076 /* send up to 100 entries in one message */ 1077 /* XXX check packet size instead */ 1078 if (count == 100) 1079 break; 1080 } 1081 if (count > 0) { 1082 send_names(id, count, stats); 1083 for (i = 0; i < count; i++) { 1084 free(stats[i].name); 1085 free(stats[i].long_name); 1086 } 1087 } else { 1088 send_status(id, SSH2_FX_EOF); 1089 } 1090 free(stats); 1091 } 1092 } 1093 1094 static void 1095 process_remove(u_int32_t id) 1096 { 1097 char *name; 1098 int r, status = SSH2_FX_FAILURE; 1099 1100 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0) 1101 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1102 1103 debug3("request %u: remove", id); 1104 logit("remove name \"%s\"", name); 1105 r = unlink(name); 1106 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1107 send_status(id, status); 1108 free(name); 1109 } 1110 1111 static void 1112 process_mkdir(u_int32_t id) 1113 { 1114 Attrib a; 1115 char *name; 1116 int r, mode, status = SSH2_FX_FAILURE; 1117 1118 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 || 1119 (r = decode_attrib(iqueue, &a)) != 0) 1120 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1121 1122 mode = (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? 1123 a.perm & 07777 : 0777; 1124 debug3("request %u: mkdir", id); 1125 logit("mkdir name \"%s\" mode 0%o", name, mode); 1126 r = mkdir(name, mode); 1127 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1128 send_status(id, status); 1129 free(name); 1130 } 1131 1132 static void 1133 process_rmdir(u_int32_t id) 1134 { 1135 char *name; 1136 int r, status; 1137 1138 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0) 1139 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1140 1141 debug3("request %u: rmdir", id); 1142 logit("rmdir name \"%s\"", name); 1143 r = rmdir(name); 1144 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1145 send_status(id, status); 1146 free(name); 1147 } 1148 1149 static void 1150 process_realpath(u_int32_t id) 1151 { 1152 char resolvedname[PATH_MAX]; 1153 char *path; 1154 int r; 1155 1156 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0) 1157 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1158 1159 if (path[0] == '\0') { 1160 free(path); 1161 path = xstrdup("."); 1162 } 1163 debug3("request %u: realpath", id); 1164 verbose("realpath \"%s\"", path); 1165 if (realpath(path, resolvedname) == NULL) { 1166 send_status(id, errno_to_portable(errno)); 1167 } else { 1168 Stat s; 1169 attrib_clear(&s.attrib); 1170 s.name = s.long_name = resolvedname; 1171 send_names(id, 1, &s); 1172 } 1173 free(path); 1174 } 1175 1176 static void 1177 process_rename(u_int32_t id) 1178 { 1179 char *oldpath, *newpath; 1180 int r, status; 1181 struct stat sb; 1182 1183 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 || 1184 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0) 1185 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1186 1187 debug3("request %u: rename", id); 1188 logit("rename old \"%s\" new \"%s\"", oldpath, newpath); 1189 status = SSH2_FX_FAILURE; 1190 if (lstat(oldpath, &sb) == -1) 1191 status = errno_to_portable(errno); 1192 else if (S_ISREG(sb.st_mode)) { 1193 /* Race-free rename of regular files */ 1194 if (link(oldpath, newpath) == -1) { 1195 if (errno == EOPNOTSUPP || errno == ENOSYS 1196 #ifdef EXDEV 1197 || errno == EXDEV 1198 #endif 1199 #ifdef LINK_OPNOTSUPP_ERRNO 1200 || errno == LINK_OPNOTSUPP_ERRNO 1201 #endif 1202 ) { 1203 struct stat st; 1204 1205 /* 1206 * fs doesn't support links, so fall back to 1207 * stat+rename. This is racy. 1208 */ 1209 if (stat(newpath, &st) == -1) { 1210 if (rename(oldpath, newpath) == -1) 1211 status = 1212 errno_to_portable(errno); 1213 else 1214 status = SSH2_FX_OK; 1215 } 1216 } else { 1217 status = errno_to_portable(errno); 1218 } 1219 } else if (unlink(oldpath) == -1) { 1220 status = errno_to_portable(errno); 1221 /* clean spare link */ 1222 unlink(newpath); 1223 } else 1224 status = SSH2_FX_OK; 1225 } else if (stat(newpath, &sb) == -1) { 1226 if (rename(oldpath, newpath) == -1) 1227 status = errno_to_portable(errno); 1228 else 1229 status = SSH2_FX_OK; 1230 } 1231 send_status(id, status); 1232 free(oldpath); 1233 free(newpath); 1234 } 1235 1236 static void 1237 process_readlink(u_int32_t id) 1238 { 1239 int r, len; 1240 char buf[PATH_MAX]; 1241 char *path; 1242 1243 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0) 1244 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1245 1246 debug3("request %u: readlink", id); 1247 verbose("readlink \"%s\"", path); 1248 if ((len = readlink(path, buf, sizeof(buf) - 1)) == -1) 1249 send_status(id, errno_to_portable(errno)); 1250 else { 1251 Stat s; 1252 1253 buf[len] = '\0'; 1254 attrib_clear(&s.attrib); 1255 s.name = s.long_name = buf; 1256 send_names(id, 1, &s); 1257 } 1258 free(path); 1259 } 1260 1261 static void 1262 process_symlink(u_int32_t id) 1263 { 1264 char *oldpath, *newpath; 1265 int r, status; 1266 1267 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 || 1268 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0) 1269 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1270 1271 debug3("request %u: symlink", id); 1272 logit("symlink old \"%s\" new \"%s\"", oldpath, newpath); 1273 /* this will fail if 'newpath' exists */ 1274 r = symlink(oldpath, newpath); 1275 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1276 send_status(id, status); 1277 free(oldpath); 1278 free(newpath); 1279 } 1280 1281 static void 1282 process_extended_posix_rename(u_int32_t id) 1283 { 1284 char *oldpath, *newpath; 1285 int r, status; 1286 1287 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 || 1288 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0) 1289 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1290 1291 debug3("request %u: posix-rename", id); 1292 logit("posix-rename old \"%s\" new \"%s\"", oldpath, newpath); 1293 r = rename(oldpath, newpath); 1294 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1295 send_status(id, status); 1296 free(oldpath); 1297 free(newpath); 1298 } 1299 1300 static void 1301 process_extended_statvfs(u_int32_t id) 1302 { 1303 char *path; 1304 struct statvfs st; 1305 int r; 1306 1307 if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0) 1308 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1309 debug3("request %u: statvfs", id); 1310 logit("statvfs \"%s\"", path); 1311 1312 if (statvfs(path, &st) != 0) 1313 send_status(id, errno_to_portable(errno)); 1314 else 1315 send_statvfs(id, &st); 1316 free(path); 1317 } 1318 1319 static void 1320 process_extended_fstatvfs(u_int32_t id) 1321 { 1322 int r, handle, fd; 1323 struct statvfs st; 1324 1325 if ((r = get_handle(iqueue, &handle)) != 0) 1326 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1327 debug("request %u: fstatvfs \"%s\" (handle %u)", 1328 id, handle_to_name(handle), handle); 1329 if ((fd = handle_to_fd(handle)) < 0) { 1330 send_status(id, SSH2_FX_FAILURE); 1331 return; 1332 } 1333 if (fstatvfs(fd, &st) != 0) 1334 send_status(id, errno_to_portable(errno)); 1335 else 1336 send_statvfs(id, &st); 1337 } 1338 1339 static void 1340 process_extended_hardlink(u_int32_t id) 1341 { 1342 char *oldpath, *newpath; 1343 int r, status; 1344 1345 if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 || 1346 (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0) 1347 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1348 1349 debug3("request %u: hardlink", id); 1350 logit("hardlink old \"%s\" new \"%s\"", oldpath, newpath); 1351 r = link(oldpath, newpath); 1352 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1353 send_status(id, status); 1354 free(oldpath); 1355 free(newpath); 1356 } 1357 1358 static void 1359 process_extended_fsync(u_int32_t id) 1360 { 1361 int handle, fd, r, status = SSH2_FX_OP_UNSUPPORTED; 1362 1363 if ((r = get_handle(iqueue, &handle)) != 0) 1364 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1365 debug3("request %u: fsync (handle %u)", id, handle); 1366 verbose("fsync \"%s\"", handle_to_name(handle)); 1367 if ((fd = handle_to_fd(handle)) < 0) 1368 status = SSH2_FX_NO_SUCH_FILE; 1369 else if (handle_is_ok(handle, HANDLE_FILE)) { 1370 r = fsync(fd); 1371 status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK; 1372 } 1373 send_status(id, status); 1374 } 1375 1376 static void 1377 process_extended(u_int32_t id) 1378 { 1379 char *request; 1380 int i, r; 1381 1382 if ((r = sshbuf_get_cstring(iqueue, &request, NULL)) != 0) 1383 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1384 for (i = 0; extended_handlers[i].handler != NULL; i++) { 1385 if (strcmp(request, extended_handlers[i].ext_name) == 0) { 1386 if (!request_permitted(&extended_handlers[i])) 1387 send_status(id, SSH2_FX_PERMISSION_DENIED); 1388 else 1389 extended_handlers[i].handler(id); 1390 break; 1391 } 1392 } 1393 if (extended_handlers[i].handler == NULL) { 1394 error("Unknown extended request \"%.100s\"", request); 1395 send_status(id, SSH2_FX_OP_UNSUPPORTED); /* MUST */ 1396 } 1397 free(request); 1398 } 1399 1400 /* stolen from ssh-agent */ 1401 1402 static void 1403 process(void) 1404 { 1405 u_int msg_len; 1406 u_int buf_len; 1407 u_int consumed; 1408 u_char type; 1409 const u_char *cp; 1410 int i, r; 1411 u_int32_t id; 1412 1413 buf_len = sshbuf_len(iqueue); 1414 if (buf_len < 5) 1415 return; /* Incomplete message. */ 1416 cp = sshbuf_ptr(iqueue); 1417 msg_len = get_u32(cp); 1418 if (msg_len > SFTP_MAX_MSG_LENGTH) { 1419 error("bad message from %s local user %s", 1420 client_addr, pw->pw_name); 1421 sftp_server_cleanup_exit(11); 1422 } 1423 if (buf_len < msg_len + 4) 1424 return; 1425 if ((r = sshbuf_consume(iqueue, 4)) != 0) 1426 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1427 buf_len -= 4; 1428 if ((r = sshbuf_get_u8(iqueue, &type)) != 0) 1429 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1430 1431 switch (type) { 1432 case SSH2_FXP_INIT: 1433 process_init(); 1434 init_done = 1; 1435 break; 1436 case SSH2_FXP_EXTENDED: 1437 if (!init_done) 1438 fatal("Received extended request before init"); 1439 if ((r = sshbuf_get_u32(iqueue, &id)) != 0) 1440 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1441 process_extended(id); 1442 break; 1443 default: 1444 if (!init_done) 1445 fatal("Received %u request before init", type); 1446 if ((r = sshbuf_get_u32(iqueue, &id)) != 0) 1447 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1448 for (i = 0; handlers[i].handler != NULL; i++) { 1449 if (type == handlers[i].type) { 1450 if (!request_permitted(&handlers[i])) { 1451 send_status(id, 1452 SSH2_FX_PERMISSION_DENIED); 1453 } else { 1454 handlers[i].handler(id); 1455 } 1456 break; 1457 } 1458 } 1459 if (handlers[i].handler == NULL) 1460 error("Unknown message %u", type); 1461 } 1462 /* discard the remaining bytes from the current packet */ 1463 if (buf_len < sshbuf_len(iqueue)) { 1464 error("iqueue grew unexpectedly"); 1465 sftp_server_cleanup_exit(255); 1466 } 1467 consumed = buf_len - sshbuf_len(iqueue); 1468 if (msg_len < consumed) { 1469 error("msg_len %u < consumed %u", msg_len, consumed); 1470 sftp_server_cleanup_exit(255); 1471 } 1472 if (msg_len > consumed && 1473 (r = sshbuf_consume(iqueue, msg_len - consumed)) != 0) 1474 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1475 } 1476 1477 /* Cleanup handler that logs active handles upon normal exit */ 1478 void 1479 sftp_server_cleanup_exit(int i) 1480 { 1481 if (pw != NULL && client_addr != NULL) { 1482 handle_log_exit(); 1483 logit("session closed for local user %s from [%s]", 1484 pw->pw_name, client_addr); 1485 } 1486 _exit(i); 1487 } 1488 1489 static void 1490 sftp_server_usage(void) 1491 { 1492 extern char *__progname; 1493 1494 fprintf(stderr, 1495 "usage: %s [-ehR] [-d start_directory] [-f log_facility] " 1496 "[-l log_level]\n\t[-P blacklisted_requests] " 1497 "[-p whitelisted_requests] [-u umask]\n" 1498 " %s -Q protocol_feature\n", 1499 __progname, __progname); 1500 exit(1); 1501 } 1502 1503 int 1504 sftp_server_main(int argc, char **argv, struct passwd *user_pw) 1505 { 1506 fd_set *rset, *wset; 1507 int i, r, in, out, max, ch, skipargs = 0, log_stderr = 0; 1508 ssize_t len, olen, set_size; 1509 SyslogFacility log_facility = SYSLOG_FACILITY_AUTH; 1510 char *cp, *homedir = NULL, buf[4*4096]; 1511 long mask; 1512 1513 extern char *optarg; 1514 extern char *__progname; 1515 1516 __progname = ssh_get_progname(argv[0]); 1517 log_init(__progname, log_level, log_facility, log_stderr); 1518 1519 pw = pwcopy(user_pw); 1520 1521 while (!skipargs && (ch = getopt(argc, argv, 1522 "d:f:l:P:p:Q:u:cehR")) != -1) { 1523 switch (ch) { 1524 case 'Q': 1525 if (strcasecmp(optarg, "requests") != 0) { 1526 fprintf(stderr, "Invalid query type\n"); 1527 exit(1); 1528 } 1529 for (i = 0; handlers[i].handler != NULL; i++) 1530 printf("%s\n", handlers[i].name); 1531 for (i = 0; extended_handlers[i].handler != NULL; i++) 1532 printf("%s\n", extended_handlers[i].name); 1533 exit(0); 1534 break; 1535 case 'R': 1536 readonly = 1; 1537 break; 1538 case 'c': 1539 /* 1540 * Ignore all arguments if we are invoked as a 1541 * shell using "sftp-server -c command" 1542 */ 1543 skipargs = 1; 1544 break; 1545 case 'e': 1546 log_stderr = 1; 1547 break; 1548 case 'l': 1549 log_level = log_level_number(optarg); 1550 if (log_level == SYSLOG_LEVEL_NOT_SET) 1551 error("Invalid log level \"%s\"", optarg); 1552 break; 1553 case 'f': 1554 log_facility = log_facility_number(optarg); 1555 if (log_facility == SYSLOG_FACILITY_NOT_SET) 1556 error("Invalid log facility \"%s\"", optarg); 1557 break; 1558 case 'd': 1559 cp = tilde_expand_filename(optarg, user_pw->pw_uid); 1560 homedir = percent_expand(cp, "d", user_pw->pw_dir, 1561 "u", user_pw->pw_name, (char *)NULL); 1562 free(cp); 1563 break; 1564 case 'p': 1565 if (request_whitelist != NULL) 1566 fatal("Permitted requests already set"); 1567 request_whitelist = xstrdup(optarg); 1568 break; 1569 case 'P': 1570 if (request_blacklist != NULL) 1571 fatal("Refused requests already set"); 1572 request_blacklist = xstrdup(optarg); 1573 break; 1574 case 'u': 1575 errno = 0; 1576 mask = strtol(optarg, &cp, 8); 1577 if (mask < 0 || mask > 0777 || *cp != '\0' || 1578 cp == optarg || (mask == 0 && errno != 0)) 1579 fatal("Invalid umask \"%s\"", optarg); 1580 (void)umask((mode_t)mask); 1581 break; 1582 case 'h': 1583 default: 1584 sftp_server_usage(); 1585 } 1586 } 1587 1588 log_init(__progname, log_level, log_facility, log_stderr); 1589 1590 #if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE) 1591 /* 1592 * On Linux, we should try to avoid making /proc/self/{mem,maps} 1593 * available to the user so that sftp access doesn't automatically 1594 * imply arbitrary code execution access that will break 1595 * restricted configurations. 1596 */ 1597 if (prctl(PR_SET_DUMPABLE, 0) != 0) 1598 fatal("unable to make the process undumpable"); 1599 #endif /* defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE) */ 1600 1601 if ((cp = getenv("SSH_CONNECTION")) != NULL) { 1602 client_addr = xstrdup(cp); 1603 if ((cp = strchr(client_addr, ' ')) == NULL) { 1604 error("Malformed SSH_CONNECTION variable: \"%s\"", 1605 getenv("SSH_CONNECTION")); 1606 sftp_server_cleanup_exit(255); 1607 } 1608 *cp = '\0'; 1609 } else 1610 client_addr = xstrdup("UNKNOWN"); 1611 1612 logit("session opened for local user %s from [%s]", 1613 pw->pw_name, client_addr); 1614 1615 in = STDIN_FILENO; 1616 out = STDOUT_FILENO; 1617 1618 #ifdef HAVE_CYGWIN 1619 setmode(in, O_BINARY); 1620 setmode(out, O_BINARY); 1621 #endif 1622 1623 max = 0; 1624 if (in > max) 1625 max = in; 1626 if (out > max) 1627 max = out; 1628 1629 if ((iqueue = sshbuf_new()) == NULL) 1630 fatal("%s: sshbuf_new failed", __func__); 1631 if ((oqueue = sshbuf_new()) == NULL) 1632 fatal("%s: sshbuf_new failed", __func__); 1633 1634 set_size = howmany(max + 1, NFDBITS) * sizeof(fd_mask); 1635 rset = xmalloc(set_size); 1636 wset = xmalloc(set_size); 1637 1638 if (homedir != NULL) { 1639 if (chdir(homedir) != 0) { 1640 error("chdir to \"%s\" failed: %s", homedir, 1641 strerror(errno)); 1642 } 1643 } 1644 1645 for (;;) { 1646 memset(rset, 0, set_size); 1647 memset(wset, 0, set_size); 1648 1649 /* 1650 * Ensure that we can read a full buffer and handle 1651 * the worst-case length packet it can generate, 1652 * otherwise apply backpressure by stopping reads. 1653 */ 1654 if ((r = sshbuf_check_reserve(iqueue, sizeof(buf))) == 0 && 1655 (r = sshbuf_check_reserve(oqueue, 1656 SFTP_MAX_MSG_LENGTH)) == 0) 1657 FD_SET(in, rset); 1658 else if (r != SSH_ERR_NO_BUFFER_SPACE) 1659 fatal("%s: sshbuf_check_reserve failed: %s", 1660 __func__, ssh_err(r)); 1661 1662 olen = sshbuf_len(oqueue); 1663 if (olen > 0) 1664 FD_SET(out, wset); 1665 1666 if (select(max+1, rset, wset, NULL, NULL) < 0) { 1667 if (errno == EINTR) 1668 continue; 1669 error("select: %s", strerror(errno)); 1670 sftp_server_cleanup_exit(2); 1671 } 1672 1673 /* copy stdin to iqueue */ 1674 if (FD_ISSET(in, rset)) { 1675 len = read(in, buf, sizeof buf); 1676 if (len == 0) { 1677 debug("read eof"); 1678 sftp_server_cleanup_exit(0); 1679 } else if (len < 0) { 1680 error("read: %s", strerror(errno)); 1681 sftp_server_cleanup_exit(1); 1682 } else if ((r = sshbuf_put(iqueue, buf, len)) != 0) { 1683 fatal("%s: buffer error: %s", 1684 __func__, ssh_err(r)); 1685 } 1686 } 1687 /* send oqueue to stdout */ 1688 if (FD_ISSET(out, wset)) { 1689 len = write(out, sshbuf_ptr(oqueue), olen); 1690 if (len < 0) { 1691 error("write: %s", strerror(errno)); 1692 sftp_server_cleanup_exit(1); 1693 } else if ((r = sshbuf_consume(oqueue, len)) != 0) { 1694 fatal("%s: buffer error: %s", 1695 __func__, ssh_err(r)); 1696 } 1697 } 1698 1699 /* 1700 * Process requests from client if we can fit the results 1701 * into the output buffer, otherwise stop processing input 1702 * and let the output queue drain. 1703 */ 1704 r = sshbuf_check_reserve(oqueue, SFTP_MAX_MSG_LENGTH); 1705 if (r == 0) 1706 process(); 1707 else if (r != SSH_ERR_NO_BUFFER_SPACE) 1708 fatal("%s: sshbuf_check_reserve: %s", 1709 __func__, ssh_err(r)); 1710 } 1711 } 1712
