9p-local.c (44067B)
1 /* 2 * 9p Posix callback 3 * 4 * Copyright IBM, Corp. 2010 5 * 6 * Authors: 7 * Anthony Liguori <aliguori@us.ibm.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2. See 10 * the COPYING file in the top-level directory. 11 */ 12 13 /* 14 * Not so fast! You might want to read the 9p developer docs first: 15 * https://wiki.qemu.org/Documentation/9p 16 */ 17 18 #include "qemu/osdep.h" 19 #include "9p.h" 20 #include "9p-local.h" 21 #include "9p-xattr.h" 22 #include "9p-util.h" 23 #include "fsdev/qemu-fsdev.h" /* local_ops */ 24 #include <arpa/inet.h> 25 #include <pwd.h> 26 #include <grp.h> 27 #include <sys/socket.h> 28 #include <sys/un.h> 29 #include "qemu/xattr.h" 30 #include "qapi/error.h" 31 #include "qemu/cutils.h" 32 #include "qemu/error-report.h" 33 #include "qemu/option.h" 34 #include <libgen.h> 35 #ifdef CONFIG_LINUX 36 #include <linux/fs.h> 37 #ifdef CONFIG_LINUX_MAGIC_H 38 #include <linux/magic.h> 39 #endif 40 #endif 41 #include <sys/ioctl.h> 42 43 #ifndef XFS_SUPER_MAGIC 44 #define XFS_SUPER_MAGIC 0x58465342 45 #endif 46 #ifndef EXT2_SUPER_MAGIC 47 #define EXT2_SUPER_MAGIC 0xEF53 48 #endif 49 #ifndef REISERFS_SUPER_MAGIC 50 #define REISERFS_SUPER_MAGIC 0x52654973 51 #endif 52 #ifndef BTRFS_SUPER_MAGIC 53 #define BTRFS_SUPER_MAGIC 0x9123683E 54 #endif 55 56 typedef struct { 57 int mountfd; 58 } LocalData; 59 60 int local_open_nofollow(FsContext *fs_ctx, const char *path, int flags, 61 mode_t mode) 62 { 63 LocalData *data = fs_ctx->private; 64 int fd = data->mountfd; 65 66 while (*path && fd != -1) { 67 const char *c; 68 int next_fd; 69 char *head; 70 71 /* Only relative paths without consecutive slashes */ 72 assert(*path != '/'); 73 74 head = g_strdup(path); 75 c = qemu_strchrnul(path, '/'); 76 if (*c) { 77 /* Intermediate path element */ 78 head[c - path] = 0; 79 path = c + 1; 80 next_fd = openat_dir(fd, head); 81 } else { 82 /* Rightmost path element */ 83 next_fd = openat_file(fd, head, flags, mode); 84 path = c; 85 } 86 g_free(head); 87 if (fd != data->mountfd) { 88 close_preserve_errno(fd); 89 } 90 fd = next_fd; 91 } 92 93 assert(fd != data->mountfd); 94 return fd; 95 } 96 97 int local_opendir_nofollow(FsContext *fs_ctx, const char *path) 98 { 99 return local_open_nofollow(fs_ctx, path, O_DIRECTORY | O_RDONLY, 0); 100 } 101 102 static void renameat_preserve_errno(int odirfd, const char *opath, int ndirfd, 103 const char *npath) 104 { 105 int serrno = errno; 106 renameat(odirfd, opath, ndirfd, npath); 107 errno = serrno; 108 } 109 110 static void unlinkat_preserve_errno(int dirfd, const char *path, int flags) 111 { 112 int serrno = errno; 113 unlinkat(dirfd, path, flags); 114 errno = serrno; 115 } 116 117 #define VIRTFS_META_DIR ".virtfs_metadata" 118 #define VIRTFS_META_ROOT_FILE VIRTFS_META_DIR "_root" 119 120 static FILE *local_fopenat(int dirfd, const char *name, const char *mode) 121 { 122 int fd, o_mode = 0; 123 FILE *fp; 124 int flags; 125 /* 126 * only supports two modes 127 */ 128 if (mode[0] == 'r') { 129 flags = O_RDONLY; 130 } else if (mode[0] == 'w') { 131 flags = O_WRONLY | O_TRUNC | O_CREAT; 132 o_mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH; 133 } else { 134 return NULL; 135 } 136 fd = openat_file(dirfd, name, flags, o_mode); 137 if (fd == -1) { 138 return NULL; 139 } 140 fp = fdopen(fd, mode); 141 if (!fp) { 142 close(fd); 143 } 144 return fp; 145 } 146 147 #define ATTR_MAX 100 148 static void local_mapped_file_attr(int dirfd, const char *name, 149 struct stat *stbuf) 150 { 151 FILE *fp; 152 char buf[ATTR_MAX]; 153 int map_dirfd; 154 155 if (strcmp(name, ".")) { 156 map_dirfd = openat_dir(dirfd, VIRTFS_META_DIR); 157 if (map_dirfd == -1) { 158 return; 159 } 160 161 fp = local_fopenat(map_dirfd, name, "r"); 162 close_preserve_errno(map_dirfd); 163 } else { 164 fp = local_fopenat(dirfd, VIRTFS_META_ROOT_FILE, "r"); 165 } 166 if (!fp) { 167 return; 168 } 169 memset(buf, 0, ATTR_MAX); 170 while (fgets(buf, ATTR_MAX, fp)) { 171 if (!strncmp(buf, "virtfs.uid", 10)) { 172 stbuf->st_uid = atoi(buf + 11); 173 } else if (!strncmp(buf, "virtfs.gid", 10)) { 174 stbuf->st_gid = atoi(buf + 11); 175 } else if (!strncmp(buf, "virtfs.mode", 11)) { 176 stbuf->st_mode = atoi(buf + 12); 177 } else if (!strncmp(buf, "virtfs.rdev", 11)) { 178 stbuf->st_rdev = atoi(buf + 12); 179 } 180 memset(buf, 0, ATTR_MAX); 181 } 182 fclose(fp); 183 } 184 185 static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf) 186 { 187 int err = -1; 188 char *dirpath = g_path_get_dirname(fs_path->data); 189 char *name = g_path_get_basename(fs_path->data); 190 int dirfd; 191 192 dirfd = local_opendir_nofollow(fs_ctx, dirpath); 193 if (dirfd == -1) { 194 goto out; 195 } 196 197 err = fstatat(dirfd, name, stbuf, AT_SYMLINK_NOFOLLOW); 198 if (err) { 199 goto err_out; 200 } 201 if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 202 /* Actual credentials are part of extended attrs */ 203 uid_t tmp_uid; 204 gid_t tmp_gid; 205 mode_t tmp_mode; 206 dev_t tmp_dev; 207 208 if (fgetxattrat_nofollow(dirfd, name, "user.virtfs.uid", &tmp_uid, 209 sizeof(uid_t)) > 0) { 210 stbuf->st_uid = le32_to_cpu(tmp_uid); 211 } 212 if (fgetxattrat_nofollow(dirfd, name, "user.virtfs.gid", &tmp_gid, 213 sizeof(gid_t)) > 0) { 214 stbuf->st_gid = le32_to_cpu(tmp_gid); 215 } 216 if (fgetxattrat_nofollow(dirfd, name, "user.virtfs.mode", &tmp_mode, 217 sizeof(mode_t)) > 0) { 218 stbuf->st_mode = le32_to_cpu(tmp_mode); 219 } 220 if (fgetxattrat_nofollow(dirfd, name, "user.virtfs.rdev", &tmp_dev, 221 sizeof(dev_t)) > 0) { 222 stbuf->st_rdev = le64_to_cpu(tmp_dev); 223 } 224 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 225 local_mapped_file_attr(dirfd, name, stbuf); 226 } 227 228 err_out: 229 close_preserve_errno(dirfd); 230 out: 231 g_free(name); 232 g_free(dirpath); 233 return err; 234 } 235 236 static int local_set_mapped_file_attrat(int dirfd, const char *name, 237 FsCred *credp) 238 { 239 FILE *fp; 240 int ret; 241 char buf[ATTR_MAX]; 242 int uid = -1, gid = -1, mode = -1, rdev = -1; 243 int map_dirfd = -1, map_fd; 244 bool is_root = !strcmp(name, "."); 245 246 if (is_root) { 247 fp = local_fopenat(dirfd, VIRTFS_META_ROOT_FILE, "r"); 248 if (!fp) { 249 if (errno == ENOENT) { 250 goto update_map_file; 251 } else { 252 return -1; 253 } 254 } 255 } else { 256 ret = mkdirat(dirfd, VIRTFS_META_DIR, 0700); 257 if (ret < 0 && errno != EEXIST) { 258 return -1; 259 } 260 261 map_dirfd = openat_dir(dirfd, VIRTFS_META_DIR); 262 if (map_dirfd == -1) { 263 return -1; 264 } 265 266 fp = local_fopenat(map_dirfd, name, "r"); 267 if (!fp) { 268 if (errno == ENOENT) { 269 goto update_map_file; 270 } else { 271 close_preserve_errno(map_dirfd); 272 return -1; 273 } 274 } 275 } 276 memset(buf, 0, ATTR_MAX); 277 while (fgets(buf, ATTR_MAX, fp)) { 278 if (!strncmp(buf, "virtfs.uid", 10)) { 279 uid = atoi(buf + 11); 280 } else if (!strncmp(buf, "virtfs.gid", 10)) { 281 gid = atoi(buf + 11); 282 } else if (!strncmp(buf, "virtfs.mode", 11)) { 283 mode = atoi(buf + 12); 284 } else if (!strncmp(buf, "virtfs.rdev", 11)) { 285 rdev = atoi(buf + 12); 286 } 287 memset(buf, 0, ATTR_MAX); 288 } 289 fclose(fp); 290 291 update_map_file: 292 if (is_root) { 293 fp = local_fopenat(dirfd, VIRTFS_META_ROOT_FILE, "w"); 294 } else { 295 fp = local_fopenat(map_dirfd, name, "w"); 296 /* We can't go this far with map_dirfd not being a valid file descriptor 297 * but some versions of gcc aren't smart enough to see it. 298 */ 299 if (map_dirfd != -1) { 300 close_preserve_errno(map_dirfd); 301 } 302 } 303 if (!fp) { 304 return -1; 305 } 306 307 map_fd = fileno(fp); 308 assert(map_fd != -1); 309 ret = fchmod(map_fd, 0600); 310 assert(ret == 0); 311 312 if (credp->fc_uid != -1) { 313 uid = credp->fc_uid; 314 } 315 if (credp->fc_gid != -1) { 316 gid = credp->fc_gid; 317 } 318 if (credp->fc_mode != (mode_t)-1) { 319 mode = credp->fc_mode; 320 } 321 if (credp->fc_rdev != -1) { 322 rdev = credp->fc_rdev; 323 } 324 325 if (uid != -1) { 326 fprintf(fp, "virtfs.uid=%d\n", uid); 327 } 328 if (gid != -1) { 329 fprintf(fp, "virtfs.gid=%d\n", gid); 330 } 331 if (mode != -1) { 332 fprintf(fp, "virtfs.mode=%d\n", mode); 333 } 334 if (rdev != -1) { 335 fprintf(fp, "virtfs.rdev=%d\n", rdev); 336 } 337 fclose(fp); 338 339 return 0; 340 } 341 342 static int fchmodat_nofollow(int dirfd, const char *name, mode_t mode) 343 { 344 struct stat stbuf; 345 int fd, ret; 346 347 /* FIXME: this should be handled with fchmodat(AT_SYMLINK_NOFOLLOW). 348 * Unfortunately, the linux kernel doesn't implement it yet. 349 */ 350 351 /* First, we clear non-racing symlinks out of the way. */ 352 if (fstatat(dirfd, name, &stbuf, AT_SYMLINK_NOFOLLOW)) { 353 return -1; 354 } 355 if (S_ISLNK(stbuf.st_mode)) { 356 errno = ELOOP; 357 return -1; 358 } 359 360 fd = openat_file(dirfd, name, O_RDONLY | O_PATH_9P_UTIL | O_NOFOLLOW, 0); 361 #if O_PATH_9P_UTIL == 0 362 /* Fallback for systems that don't support O_PATH: we depend on the file 363 * being readable or writable. 364 */ 365 if (fd == -1) { 366 /* In case the file is writable-only and isn't a directory. */ 367 if (errno == EACCES) { 368 fd = openat_file(dirfd, name, O_WRONLY, 0); 369 } 370 if (fd == -1 && errno == EISDIR) { 371 errno = EACCES; 372 } 373 } 374 if (fd == -1) { 375 return -1; 376 } 377 ret = fchmod(fd, mode); 378 #else 379 /* Access modes are ignored when O_PATH is supported. If name is a symbolic 380 * link, O_PATH | O_NOFOLLOW causes openat(2) to return a file descriptor 381 * referring to the symbolic link. 382 */ 383 if (fd == -1) { 384 return -1; 385 } 386 387 /* Now we handle racing symlinks. */ 388 ret = fstat(fd, &stbuf); 389 if (!ret) { 390 if (S_ISLNK(stbuf.st_mode)) { 391 errno = ELOOP; 392 ret = -1; 393 } else { 394 char *proc_path = g_strdup_printf("/proc/self/fd/%d", fd); 395 ret = chmod(proc_path, mode); 396 g_free(proc_path); 397 } 398 } 399 #endif 400 close_preserve_errno(fd); 401 return ret; 402 } 403 404 static int local_set_xattrat(int dirfd, const char *path, FsCred *credp) 405 { 406 int err; 407 408 if (credp->fc_uid != -1) { 409 uint32_t tmp_uid = cpu_to_le32(credp->fc_uid); 410 err = fsetxattrat_nofollow(dirfd, path, "user.virtfs.uid", &tmp_uid, 411 sizeof(uid_t), 0); 412 if (err) { 413 return err; 414 } 415 } 416 if (credp->fc_gid != -1) { 417 uint32_t tmp_gid = cpu_to_le32(credp->fc_gid); 418 err = fsetxattrat_nofollow(dirfd, path, "user.virtfs.gid", &tmp_gid, 419 sizeof(gid_t), 0); 420 if (err) { 421 return err; 422 } 423 } 424 if (credp->fc_mode != (mode_t)-1) { 425 uint32_t tmp_mode = cpu_to_le32(credp->fc_mode); 426 err = fsetxattrat_nofollow(dirfd, path, "user.virtfs.mode", &tmp_mode, 427 sizeof(mode_t), 0); 428 if (err) { 429 return err; 430 } 431 } 432 if (credp->fc_rdev != -1) { 433 uint64_t tmp_rdev = cpu_to_le64(credp->fc_rdev); 434 err = fsetxattrat_nofollow(dirfd, path, "user.virtfs.rdev", &tmp_rdev, 435 sizeof(dev_t), 0); 436 if (err) { 437 return err; 438 } 439 } 440 return 0; 441 } 442 443 static int local_set_cred_passthrough(FsContext *fs_ctx, int dirfd, 444 const char *name, FsCred *credp) 445 { 446 if (fchownat(dirfd, name, credp->fc_uid, credp->fc_gid, 447 AT_SYMLINK_NOFOLLOW) < 0) { 448 /* 449 * If we fail to change ownership and if we are 450 * using security model none. Ignore the error 451 */ 452 if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) { 453 return -1; 454 } 455 } 456 457 return fchmodat_nofollow(dirfd, name, credp->fc_mode & 07777); 458 } 459 460 static ssize_t local_readlink(FsContext *fs_ctx, V9fsPath *fs_path, 461 char *buf, size_t bufsz) 462 { 463 ssize_t tsize = -1; 464 465 if ((fs_ctx->export_flags & V9FS_SM_MAPPED) || 466 (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE)) { 467 int fd; 468 469 fd = local_open_nofollow(fs_ctx, fs_path->data, O_RDONLY, 0); 470 if (fd == -1) { 471 return -1; 472 } 473 do { 474 tsize = read(fd, (void *)buf, bufsz); 475 } while (tsize == -1 && errno == EINTR); 476 close_preserve_errno(fd); 477 } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || 478 (fs_ctx->export_flags & V9FS_SM_NONE)) { 479 char *dirpath = g_path_get_dirname(fs_path->data); 480 char *name = g_path_get_basename(fs_path->data); 481 int dirfd; 482 483 dirfd = local_opendir_nofollow(fs_ctx, dirpath); 484 if (dirfd == -1) { 485 goto out; 486 } 487 488 tsize = readlinkat(dirfd, name, buf, bufsz); 489 close_preserve_errno(dirfd); 490 out: 491 g_free(name); 492 g_free(dirpath); 493 } 494 return tsize; 495 } 496 497 static int local_close(FsContext *ctx, V9fsFidOpenState *fs) 498 { 499 return close(fs->fd); 500 } 501 502 static int local_closedir(FsContext *ctx, V9fsFidOpenState *fs) 503 { 504 return closedir(fs->dir.stream); 505 } 506 507 static int local_open(FsContext *ctx, V9fsPath *fs_path, 508 int flags, V9fsFidOpenState *fs) 509 { 510 int fd; 511 512 fd = local_open_nofollow(ctx, fs_path->data, flags, 0); 513 if (fd == -1) { 514 return -1; 515 } 516 fs->fd = fd; 517 return fs->fd; 518 } 519 520 static int local_opendir(FsContext *ctx, 521 V9fsPath *fs_path, V9fsFidOpenState *fs) 522 { 523 int dirfd; 524 DIR *stream; 525 526 dirfd = local_opendir_nofollow(ctx, fs_path->data); 527 if (dirfd == -1) { 528 return -1; 529 } 530 531 stream = fdopendir(dirfd); 532 if (!stream) { 533 close(dirfd); 534 return -1; 535 } 536 fs->dir.stream = stream; 537 return 0; 538 } 539 540 static void local_rewinddir(FsContext *ctx, V9fsFidOpenState *fs) 541 { 542 rewinddir(fs->dir.stream); 543 } 544 545 static off_t local_telldir(FsContext *ctx, V9fsFidOpenState *fs) 546 { 547 return telldir(fs->dir.stream); 548 } 549 550 static bool local_is_mapped_file_metadata(FsContext *fs_ctx, const char *name) 551 { 552 return 553 !strcmp(name, VIRTFS_META_DIR) || !strcmp(name, VIRTFS_META_ROOT_FILE); 554 } 555 556 static struct dirent *local_readdir(FsContext *ctx, V9fsFidOpenState *fs) 557 { 558 struct dirent *entry; 559 560 again: 561 entry = readdir(fs->dir.stream); 562 if (!entry) { 563 return NULL; 564 } 565 #ifdef CONFIG_DARWIN 566 int off; 567 off = telldir(fs->dir.stream); 568 /* If telldir fails, fail the entire readdir call */ 569 if (off < 0) { 570 return NULL; 571 } 572 entry->d_seekoff = off; 573 #endif 574 575 if (ctx->export_flags & V9FS_SM_MAPPED) { 576 entry->d_type = DT_UNKNOWN; 577 } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { 578 if (local_is_mapped_file_metadata(ctx, entry->d_name)) { 579 /* skip the meta data */ 580 goto again; 581 } 582 entry->d_type = DT_UNKNOWN; 583 } 584 585 return entry; 586 } 587 588 static void local_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off) 589 { 590 seekdir(fs->dir.stream, off); 591 } 592 593 static ssize_t local_preadv(FsContext *ctx, V9fsFidOpenState *fs, 594 const struct iovec *iov, 595 int iovcnt, off_t offset) 596 { 597 #ifdef CONFIG_PREADV 598 return preadv(fs->fd, iov, iovcnt, offset); 599 #else 600 int err = lseek(fs->fd, offset, SEEK_SET); 601 if (err == -1) { 602 return err; 603 } else { 604 return readv(fs->fd, iov, iovcnt); 605 } 606 #endif 607 } 608 609 static ssize_t local_pwritev(FsContext *ctx, V9fsFidOpenState *fs, 610 const struct iovec *iov, 611 int iovcnt, off_t offset) 612 { 613 ssize_t ret; 614 #ifdef CONFIG_PREADV 615 ret = pwritev(fs->fd, iov, iovcnt, offset); 616 #else 617 int err = lseek(fs->fd, offset, SEEK_SET); 618 if (err == -1) { 619 return err; 620 } else { 621 ret = writev(fs->fd, iov, iovcnt); 622 } 623 #endif 624 #ifdef CONFIG_SYNC_FILE_RANGE 625 if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) { 626 /* 627 * Initiate a writeback. This is not a data integrity sync. 628 * We want to ensure that we don't leave dirty pages in the cache 629 * after write when writeout=immediate is sepcified. 630 */ 631 sync_file_range(fs->fd, offset, ret, 632 SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE); 633 } 634 #endif 635 return ret; 636 } 637 638 static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp) 639 { 640 char *dirpath = g_path_get_dirname(fs_path->data); 641 char *name = g_path_get_basename(fs_path->data); 642 int ret = -1; 643 int dirfd; 644 645 dirfd = local_opendir_nofollow(fs_ctx, dirpath); 646 if (dirfd == -1) { 647 goto out; 648 } 649 650 if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 651 ret = local_set_xattrat(dirfd, name, credp); 652 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 653 ret = local_set_mapped_file_attrat(dirfd, name, credp); 654 } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH || 655 fs_ctx->export_flags & V9FS_SM_NONE) { 656 ret = fchmodat_nofollow(dirfd, name, credp->fc_mode); 657 } 658 close_preserve_errno(dirfd); 659 660 out: 661 g_free(dirpath); 662 g_free(name); 663 return ret; 664 } 665 666 static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path, 667 const char *name, FsCred *credp) 668 { 669 int err = -1; 670 int dirfd; 671 672 if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE && 673 local_is_mapped_file_metadata(fs_ctx, name)) { 674 errno = EINVAL; 675 return -1; 676 } 677 678 dirfd = local_opendir_nofollow(fs_ctx, dir_path->data); 679 if (dirfd == -1) { 680 return -1; 681 } 682 683 if (fs_ctx->export_flags & V9FS_SM_MAPPED || 684 fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 685 err = qemu_mknodat(dirfd, name, fs_ctx->fmode | S_IFREG, 0); 686 if (err == -1) { 687 goto out; 688 } 689 690 if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 691 err = local_set_xattrat(dirfd, name, credp); 692 } else { 693 err = local_set_mapped_file_attrat(dirfd, name, credp); 694 } 695 if (err == -1) { 696 goto err_end; 697 } 698 } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH || 699 fs_ctx->export_flags & V9FS_SM_NONE) { 700 err = qemu_mknodat(dirfd, name, credp->fc_mode, credp->fc_rdev); 701 if (err == -1) { 702 goto out; 703 } 704 err = local_set_cred_passthrough(fs_ctx, dirfd, name, credp); 705 if (err == -1) { 706 goto err_end; 707 } 708 } 709 goto out; 710 711 err_end: 712 unlinkat_preserve_errno(dirfd, name, 0); 713 out: 714 close_preserve_errno(dirfd); 715 return err; 716 } 717 718 static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path, 719 const char *name, FsCred *credp) 720 { 721 int err = -1; 722 int dirfd; 723 724 if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE && 725 local_is_mapped_file_metadata(fs_ctx, name)) { 726 errno = EINVAL; 727 return -1; 728 } 729 730 dirfd = local_opendir_nofollow(fs_ctx, dir_path->data); 731 if (dirfd == -1) { 732 return -1; 733 } 734 735 if (fs_ctx->export_flags & V9FS_SM_MAPPED || 736 fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 737 err = mkdirat(dirfd, name, fs_ctx->dmode); 738 if (err == -1) { 739 goto out; 740 } 741 credp->fc_mode = credp->fc_mode | S_IFDIR; 742 743 if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 744 err = local_set_xattrat(dirfd, name, credp); 745 } else { 746 err = local_set_mapped_file_attrat(dirfd, name, credp); 747 } 748 if (err == -1) { 749 goto err_end; 750 } 751 } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH || 752 fs_ctx->export_flags & V9FS_SM_NONE) { 753 err = mkdirat(dirfd, name, credp->fc_mode); 754 if (err == -1) { 755 goto out; 756 } 757 err = local_set_cred_passthrough(fs_ctx, dirfd, name, credp); 758 if (err == -1) { 759 goto err_end; 760 } 761 } 762 goto out; 763 764 err_end: 765 unlinkat_preserve_errno(dirfd, name, AT_REMOVEDIR); 766 out: 767 close_preserve_errno(dirfd); 768 return err; 769 } 770 771 static int local_fstat(FsContext *fs_ctx, int fid_type, 772 V9fsFidOpenState *fs, struct stat *stbuf) 773 { 774 int err, fd; 775 776 if (fid_type == P9_FID_DIR) { 777 fd = dirfd(fs->dir.stream); 778 } else { 779 fd = fs->fd; 780 } 781 782 err = fstat(fd, stbuf); 783 if (err) { 784 return err; 785 } 786 if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 787 /* Actual credentials are part of extended attrs */ 788 uid_t tmp_uid; 789 gid_t tmp_gid; 790 mode_t tmp_mode; 791 dev_t tmp_dev; 792 793 if (qemu_fgetxattr(fd, "user.virtfs.uid", 794 &tmp_uid, sizeof(uid_t)) > 0) { 795 stbuf->st_uid = le32_to_cpu(tmp_uid); 796 } 797 if (qemu_fgetxattr(fd, "user.virtfs.gid", 798 &tmp_gid, sizeof(gid_t)) > 0) { 799 stbuf->st_gid = le32_to_cpu(tmp_gid); 800 } 801 if (qemu_fgetxattr(fd, "user.virtfs.mode", 802 &tmp_mode, sizeof(mode_t)) > 0) { 803 stbuf->st_mode = le32_to_cpu(tmp_mode); 804 } 805 if (qemu_fgetxattr(fd, "user.virtfs.rdev", 806 &tmp_dev, sizeof(dev_t)) > 0) { 807 stbuf->st_rdev = le64_to_cpu(tmp_dev); 808 } 809 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 810 errno = EOPNOTSUPP; 811 return -1; 812 } 813 return err; 814 } 815 816 static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name, 817 int flags, FsCred *credp, V9fsFidOpenState *fs) 818 { 819 int fd = -1; 820 int err = -1; 821 int dirfd; 822 823 if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE && 824 local_is_mapped_file_metadata(fs_ctx, name)) { 825 errno = EINVAL; 826 return -1; 827 } 828 829 /* 830 * Mark all the open to not follow symlinks 831 */ 832 flags |= O_NOFOLLOW; 833 834 dirfd = local_opendir_nofollow(fs_ctx, dir_path->data); 835 if (dirfd == -1) { 836 return -1; 837 } 838 839 /* Determine the security model */ 840 if (fs_ctx->export_flags & V9FS_SM_MAPPED || 841 fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 842 fd = openat_file(dirfd, name, flags, fs_ctx->fmode); 843 if (fd == -1) { 844 goto out; 845 } 846 credp->fc_mode = credp->fc_mode | S_IFREG; 847 if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 848 /* Set cleint credentials in xattr */ 849 err = local_set_xattrat(dirfd, name, credp); 850 } else { 851 err = local_set_mapped_file_attrat(dirfd, name, credp); 852 } 853 if (err == -1) { 854 goto err_end; 855 } 856 } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || 857 (fs_ctx->export_flags & V9FS_SM_NONE)) { 858 fd = openat_file(dirfd, name, flags, credp->fc_mode); 859 if (fd == -1) { 860 goto out; 861 } 862 err = local_set_cred_passthrough(fs_ctx, dirfd, name, credp); 863 if (err == -1) { 864 goto err_end; 865 } 866 } 867 err = fd; 868 fs->fd = fd; 869 goto out; 870 871 err_end: 872 unlinkat_preserve_errno(dirfd, name, 873 flags & O_DIRECTORY ? AT_REMOVEDIR : 0); 874 close_preserve_errno(fd); 875 out: 876 close_preserve_errno(dirfd); 877 return err; 878 } 879 880 881 static int local_symlink(FsContext *fs_ctx, const char *oldpath, 882 V9fsPath *dir_path, const char *name, FsCred *credp) 883 { 884 int err = -1; 885 int dirfd; 886 887 if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE && 888 local_is_mapped_file_metadata(fs_ctx, name)) { 889 errno = EINVAL; 890 return -1; 891 } 892 893 dirfd = local_opendir_nofollow(fs_ctx, dir_path->data); 894 if (dirfd == -1) { 895 return -1; 896 } 897 898 /* Determine the security model */ 899 if (fs_ctx->export_flags & V9FS_SM_MAPPED || 900 fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 901 int fd; 902 ssize_t oldpath_size, write_size; 903 904 fd = openat_file(dirfd, name, O_CREAT | O_EXCL | O_RDWR, 905 fs_ctx->fmode); 906 if (fd == -1) { 907 goto out; 908 } 909 /* Write the oldpath (target) to the file. */ 910 oldpath_size = strlen(oldpath); 911 do { 912 write_size = write(fd, (void *)oldpath, oldpath_size); 913 } while (write_size == -1 && errno == EINTR); 914 close_preserve_errno(fd); 915 916 if (write_size != oldpath_size) { 917 goto err_end; 918 } 919 /* Set cleint credentials in symlink's xattr */ 920 credp->fc_mode = credp->fc_mode | S_IFLNK; 921 922 if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 923 err = local_set_xattrat(dirfd, name, credp); 924 } else { 925 err = local_set_mapped_file_attrat(dirfd, name, credp); 926 } 927 if (err == -1) { 928 goto err_end; 929 } 930 } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH || 931 fs_ctx->export_flags & V9FS_SM_NONE) { 932 err = symlinkat(oldpath, dirfd, name); 933 if (err) { 934 goto out; 935 } 936 err = fchownat(dirfd, name, credp->fc_uid, credp->fc_gid, 937 AT_SYMLINK_NOFOLLOW); 938 if (err == -1) { 939 /* 940 * If we fail to change ownership and if we are 941 * using security model none. Ignore the error 942 */ 943 if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) { 944 goto err_end; 945 } else { 946 err = 0; 947 } 948 } 949 } 950 goto out; 951 952 err_end: 953 unlinkat_preserve_errno(dirfd, name, 0); 954 out: 955 close_preserve_errno(dirfd); 956 return err; 957 } 958 959 static int local_link(FsContext *ctx, V9fsPath *oldpath, 960 V9fsPath *dirpath, const char *name) 961 { 962 char *odirpath = g_path_get_dirname(oldpath->data); 963 char *oname = g_path_get_basename(oldpath->data); 964 int ret = -1; 965 int odirfd, ndirfd; 966 967 if (ctx->export_flags & V9FS_SM_MAPPED_FILE && 968 local_is_mapped_file_metadata(ctx, name)) { 969 errno = EINVAL; 970 goto out; 971 } 972 973 odirfd = local_opendir_nofollow(ctx, odirpath); 974 if (odirfd == -1) { 975 goto out; 976 } 977 978 ndirfd = local_opendir_nofollow(ctx, dirpath->data); 979 if (ndirfd == -1) { 980 close_preserve_errno(odirfd); 981 goto out; 982 } 983 984 ret = linkat(odirfd, oname, ndirfd, name, 0); 985 if (ret < 0) { 986 goto out_close; 987 } 988 989 /* now link the virtfs_metadata files */ 990 if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { 991 int omap_dirfd, nmap_dirfd; 992 993 ret = mkdirat(ndirfd, VIRTFS_META_DIR, 0700); 994 if (ret < 0 && errno != EEXIST) { 995 goto err_undo_link; 996 } 997 998 omap_dirfd = openat_dir(odirfd, VIRTFS_META_DIR); 999 if (omap_dirfd == -1) { 1000 goto err; 1001 } 1002 1003 nmap_dirfd = openat_dir(ndirfd, VIRTFS_META_DIR); 1004 if (nmap_dirfd == -1) { 1005 close_preserve_errno(omap_dirfd); 1006 goto err; 1007 } 1008 1009 ret = linkat(omap_dirfd, oname, nmap_dirfd, name, 0); 1010 close_preserve_errno(nmap_dirfd); 1011 close_preserve_errno(omap_dirfd); 1012 if (ret < 0 && errno != ENOENT) { 1013 goto err_undo_link; 1014 } 1015 1016 ret = 0; 1017 } 1018 goto out_close; 1019 1020 err: 1021 ret = -1; 1022 err_undo_link: 1023 unlinkat_preserve_errno(ndirfd, name, 0); 1024 out_close: 1025 close_preserve_errno(ndirfd); 1026 close_preserve_errno(odirfd); 1027 out: 1028 g_free(oname); 1029 g_free(odirpath); 1030 return ret; 1031 } 1032 1033 static int local_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size) 1034 { 1035 int fd, ret; 1036 1037 fd = local_open_nofollow(ctx, fs_path->data, O_WRONLY, 0); 1038 if (fd == -1) { 1039 return -1; 1040 } 1041 ret = ftruncate(fd, size); 1042 close_preserve_errno(fd); 1043 return ret; 1044 } 1045 1046 static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp) 1047 { 1048 char *dirpath = g_path_get_dirname(fs_path->data); 1049 char *name = g_path_get_basename(fs_path->data); 1050 int ret = -1; 1051 int dirfd; 1052 1053 dirfd = local_opendir_nofollow(fs_ctx, dirpath); 1054 if (dirfd == -1) { 1055 goto out; 1056 } 1057 1058 if ((credp->fc_uid == -1 && credp->fc_gid == -1) || 1059 (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || 1060 (fs_ctx->export_flags & V9FS_SM_NONE)) { 1061 ret = fchownat(dirfd, name, credp->fc_uid, credp->fc_gid, 1062 AT_SYMLINK_NOFOLLOW); 1063 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 1064 ret = local_set_xattrat(dirfd, name, credp); 1065 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 1066 ret = local_set_mapped_file_attrat(dirfd, name, credp); 1067 } 1068 1069 close_preserve_errno(dirfd); 1070 out: 1071 g_free(name); 1072 g_free(dirpath); 1073 return ret; 1074 } 1075 1076 static int local_utimensat(FsContext *s, V9fsPath *fs_path, 1077 const struct timespec *buf) 1078 { 1079 char *dirpath = g_path_get_dirname(fs_path->data); 1080 char *name = g_path_get_basename(fs_path->data); 1081 int dirfd, ret = -1; 1082 1083 dirfd = local_opendir_nofollow(s, dirpath); 1084 if (dirfd == -1) { 1085 goto out; 1086 } 1087 1088 ret = utimensat(dirfd, name, buf, AT_SYMLINK_NOFOLLOW); 1089 close_preserve_errno(dirfd); 1090 out: 1091 g_free(dirpath); 1092 g_free(name); 1093 return ret; 1094 } 1095 1096 static int local_unlinkat_common(FsContext *ctx, int dirfd, const char *name, 1097 int flags) 1098 { 1099 int ret; 1100 1101 if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { 1102 int map_dirfd; 1103 1104 /* We need to remove the metadata as well: 1105 * - the metadata directory if we're removing a directory 1106 * - the metadata file in the parent's metadata directory 1107 * 1108 * If any of these are missing (ie, ENOENT) then we're probably 1109 * trying to remove something that wasn't created in mapped-file 1110 * mode. We just ignore the error. 1111 */ 1112 if (flags == AT_REMOVEDIR) { 1113 int fd; 1114 1115 fd = openat_dir(dirfd, name); 1116 if (fd == -1) { 1117 return -1; 1118 } 1119 ret = unlinkat(fd, VIRTFS_META_DIR, AT_REMOVEDIR); 1120 close_preserve_errno(fd); 1121 if (ret < 0 && errno != ENOENT) { 1122 return -1; 1123 } 1124 } 1125 map_dirfd = openat_dir(dirfd, VIRTFS_META_DIR); 1126 if (map_dirfd != -1) { 1127 ret = unlinkat(map_dirfd, name, 0); 1128 close_preserve_errno(map_dirfd); 1129 if (ret < 0 && errno != ENOENT) { 1130 return -1; 1131 } 1132 } else if (errno != ENOENT) { 1133 return -1; 1134 } 1135 } 1136 1137 return unlinkat(dirfd, name, flags); 1138 } 1139 1140 static int local_remove(FsContext *ctx, const char *path) 1141 { 1142 struct stat stbuf; 1143 char *dirpath = g_path_get_dirname(path); 1144 char *name = g_path_get_basename(path); 1145 int flags = 0; 1146 int dirfd; 1147 int err = -1; 1148 1149 dirfd = local_opendir_nofollow(ctx, dirpath); 1150 if (dirfd == -1) { 1151 goto out; 1152 } 1153 1154 if (fstatat(dirfd, name, &stbuf, AT_SYMLINK_NOFOLLOW) < 0) { 1155 goto err_out; 1156 } 1157 1158 if (S_ISDIR(stbuf.st_mode)) { 1159 flags |= AT_REMOVEDIR; 1160 } 1161 1162 err = local_unlinkat_common(ctx, dirfd, name, flags); 1163 err_out: 1164 close_preserve_errno(dirfd); 1165 out: 1166 g_free(name); 1167 g_free(dirpath); 1168 return err; 1169 } 1170 1171 static int local_fsync(FsContext *ctx, int fid_type, 1172 V9fsFidOpenState *fs, int datasync) 1173 { 1174 int fd; 1175 1176 if (fid_type == P9_FID_DIR) { 1177 fd = dirfd(fs->dir.stream); 1178 } else { 1179 fd = fs->fd; 1180 } 1181 1182 if (datasync) { 1183 return qemu_fdatasync(fd); 1184 } else { 1185 return fsync(fd); 1186 } 1187 } 1188 1189 static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf) 1190 { 1191 int fd, ret; 1192 1193 fd = local_open_nofollow(s, fs_path->data, O_RDONLY, 0); 1194 if (fd == -1) { 1195 return -1; 1196 } 1197 ret = fstatfs(fd, stbuf); 1198 close_preserve_errno(fd); 1199 return ret; 1200 } 1201 1202 static ssize_t local_lgetxattr(FsContext *ctx, V9fsPath *fs_path, 1203 const char *name, void *value, size_t size) 1204 { 1205 char *path = fs_path->data; 1206 1207 return v9fs_get_xattr(ctx, path, name, value, size); 1208 } 1209 1210 static ssize_t local_llistxattr(FsContext *ctx, V9fsPath *fs_path, 1211 void *value, size_t size) 1212 { 1213 char *path = fs_path->data; 1214 1215 return v9fs_list_xattr(ctx, path, value, size); 1216 } 1217 1218 static int local_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name, 1219 void *value, size_t size, int flags) 1220 { 1221 char *path = fs_path->data; 1222 1223 return v9fs_set_xattr(ctx, path, name, value, size, flags); 1224 } 1225 1226 static int local_lremovexattr(FsContext *ctx, V9fsPath *fs_path, 1227 const char *name) 1228 { 1229 char *path = fs_path->data; 1230 1231 return v9fs_remove_xattr(ctx, path, name); 1232 } 1233 1234 static int local_name_to_path(FsContext *ctx, V9fsPath *dir_path, 1235 const char *name, V9fsPath *target) 1236 { 1237 if (ctx->export_flags & V9FS_SM_MAPPED_FILE && 1238 local_is_mapped_file_metadata(ctx, name)) { 1239 errno = EINVAL; 1240 return -1; 1241 } 1242 1243 if (dir_path) { 1244 if (!strcmp(name, ".")) { 1245 /* "." relative to "foo/bar" is "foo/bar" */ 1246 v9fs_path_copy(target, dir_path); 1247 } else if (!strcmp(name, "..")) { 1248 if (!strcmp(dir_path->data, ".")) { 1249 /* ".." relative to the root is "." */ 1250 v9fs_path_sprintf(target, "."); 1251 } else { 1252 char *tmp = g_path_get_dirname(dir_path->data); 1253 /* Symbolic links are resolved by the client. We can assume 1254 * that ".." relative to "foo/bar" is equivalent to "foo" 1255 */ 1256 v9fs_path_sprintf(target, "%s", tmp); 1257 g_free(tmp); 1258 } 1259 } else { 1260 assert(!strchr(name, '/')); 1261 v9fs_path_sprintf(target, "%s/%s", dir_path->data, name); 1262 } 1263 } else if (!strcmp(name, "/") || !strcmp(name, ".") || 1264 !strcmp(name, "..")) { 1265 /* This is the root fid */ 1266 v9fs_path_sprintf(target, "."); 1267 } else { 1268 assert(!strchr(name, '/')); 1269 v9fs_path_sprintf(target, "./%s", name); 1270 } 1271 return 0; 1272 } 1273 1274 static int local_renameat(FsContext *ctx, V9fsPath *olddir, 1275 const char *old_name, V9fsPath *newdir, 1276 const char *new_name) 1277 { 1278 int ret; 1279 int odirfd, ndirfd; 1280 1281 if (ctx->export_flags & V9FS_SM_MAPPED_FILE && 1282 (local_is_mapped_file_metadata(ctx, old_name) || 1283 local_is_mapped_file_metadata(ctx, new_name))) { 1284 errno = EINVAL; 1285 return -1; 1286 } 1287 1288 odirfd = local_opendir_nofollow(ctx, olddir->data); 1289 if (odirfd == -1) { 1290 return -1; 1291 } 1292 1293 ndirfd = local_opendir_nofollow(ctx, newdir->data); 1294 if (ndirfd == -1) { 1295 close_preserve_errno(odirfd); 1296 return -1; 1297 } 1298 1299 ret = renameat(odirfd, old_name, ndirfd, new_name); 1300 if (ret < 0) { 1301 goto out; 1302 } 1303 1304 if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { 1305 int omap_dirfd, nmap_dirfd; 1306 1307 ret = mkdirat(ndirfd, VIRTFS_META_DIR, 0700); 1308 if (ret < 0 && errno != EEXIST) { 1309 goto err_undo_rename; 1310 } 1311 1312 omap_dirfd = openat_dir(odirfd, VIRTFS_META_DIR); 1313 if (omap_dirfd == -1) { 1314 goto err; 1315 } 1316 1317 nmap_dirfd = openat_dir(ndirfd, VIRTFS_META_DIR); 1318 if (nmap_dirfd == -1) { 1319 close_preserve_errno(omap_dirfd); 1320 goto err; 1321 } 1322 1323 /* rename the .virtfs_metadata files */ 1324 ret = renameat(omap_dirfd, old_name, nmap_dirfd, new_name); 1325 close_preserve_errno(nmap_dirfd); 1326 close_preserve_errno(omap_dirfd); 1327 if (ret < 0 && errno != ENOENT) { 1328 goto err_undo_rename; 1329 } 1330 1331 ret = 0; 1332 } 1333 goto out; 1334 1335 err: 1336 ret = -1; 1337 err_undo_rename: 1338 renameat_preserve_errno(ndirfd, new_name, odirfd, old_name); 1339 out: 1340 close_preserve_errno(ndirfd); 1341 close_preserve_errno(odirfd); 1342 return ret; 1343 } 1344 1345 static void v9fs_path_init_dirname(V9fsPath *path, const char *str) 1346 { 1347 path->data = g_path_get_dirname(str); 1348 path->size = strlen(path->data) + 1; 1349 } 1350 1351 static int local_rename(FsContext *ctx, const char *oldpath, 1352 const char *newpath) 1353 { 1354 int err; 1355 char *oname = g_path_get_basename(oldpath); 1356 char *nname = g_path_get_basename(newpath); 1357 V9fsPath olddir, newdir; 1358 1359 v9fs_path_init_dirname(&olddir, oldpath); 1360 v9fs_path_init_dirname(&newdir, newpath); 1361 1362 err = local_renameat(ctx, &olddir, oname, &newdir, nname); 1363 1364 v9fs_path_free(&newdir); 1365 v9fs_path_free(&olddir); 1366 g_free(nname); 1367 g_free(oname); 1368 1369 return err; 1370 } 1371 1372 static int local_unlinkat(FsContext *ctx, V9fsPath *dir, 1373 const char *name, int flags) 1374 { 1375 int ret; 1376 int dirfd; 1377 1378 if (ctx->export_flags & V9FS_SM_MAPPED_FILE && 1379 local_is_mapped_file_metadata(ctx, name)) { 1380 errno = EINVAL; 1381 return -1; 1382 } 1383 1384 dirfd = local_opendir_nofollow(ctx, dir->data); 1385 if (dirfd == -1) { 1386 return -1; 1387 } 1388 1389 ret = local_unlinkat_common(ctx, dirfd, name, flags); 1390 close_preserve_errno(dirfd); 1391 return ret; 1392 } 1393 1394 #ifdef FS_IOC_GETVERSION 1395 static int local_ioc_getversion(FsContext *ctx, V9fsPath *path, 1396 mode_t st_mode, uint64_t *st_gen) 1397 { 1398 int err; 1399 V9fsFidOpenState fid_open; 1400 1401 /* 1402 * Do not try to open special files like device nodes, fifos etc 1403 * We can get fd for regular files and directories only 1404 */ 1405 if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) { 1406 errno = ENOTTY; 1407 return -1; 1408 } 1409 err = local_open(ctx, path, O_RDONLY, &fid_open); 1410 if (err < 0) { 1411 return err; 1412 } 1413 err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen); 1414 local_close(ctx, &fid_open); 1415 return err; 1416 } 1417 #endif 1418 1419 static int local_ioc_getversion_init(FsContext *ctx, LocalData *data, Error **errp) 1420 { 1421 #ifdef FS_IOC_GETVERSION 1422 struct statfs stbuf; 1423 1424 /* 1425 * use ioc_getversion only if the ioctl is definied 1426 */ 1427 if (fstatfs(data->mountfd, &stbuf) < 0) { 1428 error_setg_errno(errp, errno, 1429 "failed to stat file system at '%s'", ctx->fs_root); 1430 return -1; 1431 } 1432 switch (stbuf.f_type) { 1433 case EXT2_SUPER_MAGIC: 1434 case BTRFS_SUPER_MAGIC: 1435 case REISERFS_SUPER_MAGIC: 1436 case XFS_SUPER_MAGIC: 1437 ctx->exops.get_st_gen = local_ioc_getversion; 1438 break; 1439 } 1440 #endif 1441 return 0; 1442 } 1443 1444 static int local_init(FsContext *ctx, Error **errp) 1445 { 1446 LocalData *data = g_malloc(sizeof(*data)); 1447 1448 data->mountfd = open(ctx->fs_root, O_DIRECTORY | O_RDONLY); 1449 if (data->mountfd == -1) { 1450 error_setg_errno(errp, errno, "failed to open '%s'", ctx->fs_root); 1451 goto err; 1452 } 1453 1454 if (local_ioc_getversion_init(ctx, data, errp) < 0) { 1455 close(data->mountfd); 1456 goto err; 1457 } 1458 1459 if (ctx->export_flags & V9FS_SM_PASSTHROUGH) { 1460 ctx->xops = passthrough_xattr_ops; 1461 } else if (ctx->export_flags & V9FS_SM_MAPPED) { 1462 ctx->xops = mapped_xattr_ops; 1463 } else if (ctx->export_flags & V9FS_SM_NONE) { 1464 ctx->xops = none_xattr_ops; 1465 } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { 1466 /* 1467 * xattr operation for mapped-file and passthrough 1468 * remain same. 1469 */ 1470 ctx->xops = passthrough_xattr_ops; 1471 } 1472 ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT; 1473 1474 ctx->private = data; 1475 return 0; 1476 1477 err: 1478 g_free(data); 1479 return -1; 1480 } 1481 1482 static void local_cleanup(FsContext *ctx) 1483 { 1484 LocalData *data = ctx->private; 1485 1486 if (!data) { 1487 return; 1488 } 1489 1490 close(data->mountfd); 1491 g_free(data); 1492 } 1493 1494 static void error_append_security_model_hint(Error *const *errp) 1495 { 1496 error_append_hint(errp, "Valid options are: security_model=" 1497 "[passthrough|mapped-xattr|mapped-file|none]\n"); 1498 } 1499 1500 static int local_parse_opts(QemuOpts *opts, FsDriverEntry *fse, Error **errp) 1501 { 1502 ERRP_GUARD(); 1503 const char *sec_model = qemu_opt_get(opts, "security_model"); 1504 const char *path = qemu_opt_get(opts, "path"); 1505 const char *multidevs = qemu_opt_get(opts, "multidevs"); 1506 1507 if (!sec_model) { 1508 error_setg(errp, "security_model property not set"); 1509 error_append_security_model_hint(errp); 1510 return -1; 1511 } 1512 1513 if (!strcmp(sec_model, "passthrough")) { 1514 fse->export_flags |= V9FS_SM_PASSTHROUGH; 1515 } else if (!strcmp(sec_model, "mapped") || 1516 !strcmp(sec_model, "mapped-xattr")) { 1517 fse->export_flags |= V9FS_SM_MAPPED; 1518 } else if (!strcmp(sec_model, "none")) { 1519 fse->export_flags |= V9FS_SM_NONE; 1520 } else if (!strcmp(sec_model, "mapped-file")) { 1521 fse->export_flags |= V9FS_SM_MAPPED_FILE; 1522 } else { 1523 error_setg(errp, "invalid security_model property '%s'", sec_model); 1524 error_append_security_model_hint(errp); 1525 return -1; 1526 } 1527 1528 if (multidevs) { 1529 if (!strcmp(multidevs, "remap")) { 1530 fse->export_flags &= ~V9FS_FORBID_MULTIDEVS; 1531 fse->export_flags |= V9FS_REMAP_INODES; 1532 } else if (!strcmp(multidevs, "forbid")) { 1533 fse->export_flags &= ~V9FS_REMAP_INODES; 1534 fse->export_flags |= V9FS_FORBID_MULTIDEVS; 1535 } else if (!strcmp(multidevs, "warn")) { 1536 fse->export_flags &= ~V9FS_FORBID_MULTIDEVS; 1537 fse->export_flags &= ~V9FS_REMAP_INODES; 1538 } else { 1539 error_setg(errp, "invalid multidevs property '%s'", 1540 multidevs); 1541 error_append_hint(errp, "Valid options are: multidevs=" 1542 "[remap|forbid|warn]\n"); 1543 return -1; 1544 } 1545 } 1546 1547 if (!path) { 1548 error_setg(errp, "path property not set"); 1549 return -1; 1550 } 1551 1552 if (fsdev_throttle_parse_opts(opts, &fse->fst, errp)) { 1553 error_prepend(errp, "invalid throttle configuration: "); 1554 return -1; 1555 } 1556 1557 if (fse->export_flags & V9FS_SM_MAPPED || 1558 fse->export_flags & V9FS_SM_MAPPED_FILE) { 1559 fse->fmode = 1560 qemu_opt_get_number(opts, "fmode", SM_LOCAL_MODE_BITS) & 0777; 1561 fse->dmode = 1562 qemu_opt_get_number(opts, "dmode", SM_LOCAL_DIR_MODE_BITS) & 0777; 1563 } else { 1564 if (qemu_opt_find(opts, "fmode")) { 1565 error_setg(errp, "fmode is only valid for mapped security modes"); 1566 return -1; 1567 } 1568 if (qemu_opt_find(opts, "dmode")) { 1569 error_setg(errp, "dmode is only valid for mapped security modes"); 1570 return -1; 1571 } 1572 } 1573 1574 fse->path = g_strdup(path); 1575 1576 return 0; 1577 } 1578 1579 FileOperations local_ops = { 1580 .parse_opts = local_parse_opts, 1581 .init = local_init, 1582 .cleanup = local_cleanup, 1583 .lstat = local_lstat, 1584 .readlink = local_readlink, 1585 .close = local_close, 1586 .closedir = local_closedir, 1587 .open = local_open, 1588 .opendir = local_opendir, 1589 .rewinddir = local_rewinddir, 1590 .telldir = local_telldir, 1591 .readdir = local_readdir, 1592 .seekdir = local_seekdir, 1593 .preadv = local_preadv, 1594 .pwritev = local_pwritev, 1595 .chmod = local_chmod, 1596 .mknod = local_mknod, 1597 .mkdir = local_mkdir, 1598 .fstat = local_fstat, 1599 .open2 = local_open2, 1600 .symlink = local_symlink, 1601 .link = local_link, 1602 .truncate = local_truncate, 1603 .rename = local_rename, 1604 .chown = local_chown, 1605 .utimensat = local_utimensat, 1606 .remove = local_remove, 1607 .fsync = local_fsync, 1608 .statfs = local_statfs, 1609 .lgetxattr = local_lgetxattr, 1610 .llistxattr = local_llistxattr, 1611 .lsetxattr = local_lsetxattr, 1612 .lremovexattr = local_lremovexattr, 1613 .name_to_path = local_name_to_path, 1614 .renameat = local_renameat, 1615 .unlinkat = local_unlinkat, 1616 };