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 #include "qemu/osdep.h" 15 #include "9p.h" 16 #include "9p-xattr.h" 17 #include "fsdev/qemu-fsdev.h" /* local_ops */ 18 #include <arpa/inet.h> 19 #include <pwd.h> 20 #include <grp.h> 21 #include <sys/socket.h> 22 #include <sys/un.h> 23 #include "qemu/xattr.h" 24 #include "qemu/cutils.h" 25 #include "qemu/error-report.h" 26 #include <libgen.h> 27 #include <linux/fs.h> 28 #ifdef CONFIG_LINUX_MAGIC_H 29 #include <linux/magic.h> 30 #endif 31 #include <sys/ioctl.h> 32 33 #ifndef XFS_SUPER_MAGIC 34 #define XFS_SUPER_MAGIC 0x58465342 35 #endif 36 #ifndef EXT2_SUPER_MAGIC 37 #define EXT2_SUPER_MAGIC 0xEF53 38 #endif 39 #ifndef REISERFS_SUPER_MAGIC 40 #define REISERFS_SUPER_MAGIC 0x52654973 41 #endif 42 #ifndef BTRFS_SUPER_MAGIC 43 #define BTRFS_SUPER_MAGIC 0x9123683E 44 #endif 45 46 #define VIRTFS_META_DIR ".virtfs_metadata" 47 48 static char *local_mapped_attr_path(FsContext *ctx, const char *path) 49 { 50 int dirlen; 51 const char *name = strrchr(path, '/'); 52 if (name) { 53 dirlen = name - path; 54 ++name; 55 } else { 56 name = path; 57 dirlen = 0; 58 } 59 return g_strdup_printf("%s/%.*s/%s/%s", ctx->fs_root, 60 dirlen, path, VIRTFS_META_DIR, name); 61 } 62 63 static FILE *local_fopen(const char *path, const char *mode) 64 { 65 int fd, o_mode = 0; 66 FILE *fp; 67 int flags = O_NOFOLLOW; 68 /* 69 * only supports two modes 70 */ 71 if (mode[0] == 'r') { 72 flags |= O_RDONLY; 73 } else if (mode[0] == 'w') { 74 flags |= O_WRONLY | O_TRUNC | O_CREAT; 75 o_mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH; 76 } else { 77 return NULL; 78 } 79 fd = open(path, flags, o_mode); 80 if (fd == -1) { 81 return NULL; 82 } 83 fp = fdopen(fd, mode); 84 if (!fp) { 85 close(fd); 86 } 87 return fp; 88 } 89 90 #define ATTR_MAX 100 91 static void local_mapped_file_attr(FsContext *ctx, const char *path, 92 struct stat *stbuf) 93 { 94 FILE *fp; 95 char buf[ATTR_MAX]; 96 char *attr_path; 97 98 attr_path = local_mapped_attr_path(ctx, path); 99 fp = local_fopen(attr_path, "r"); 100 g_free(attr_path); 101 if (!fp) { 102 return; 103 } 104 memset(buf, 0, ATTR_MAX); 105 while (fgets(buf, ATTR_MAX, fp)) { 106 if (!strncmp(buf, "virtfs.uid", 10)) { 107 stbuf->st_uid = atoi(buf+11); 108 } else if (!strncmp(buf, "virtfs.gid", 10)) { 109 stbuf->st_gid = atoi(buf+11); 110 } else if (!strncmp(buf, "virtfs.mode", 11)) { 111 stbuf->st_mode = atoi(buf+12); 112 } else if (!strncmp(buf, "virtfs.rdev", 11)) { 113 stbuf->st_rdev = atoi(buf+12); 114 } 115 memset(buf, 0, ATTR_MAX); 116 } 117 fclose(fp); 118 } 119 120 static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf) 121 { 122 int err; 123 char *buffer; 124 char *path = fs_path->data; 125 126 buffer = rpath(fs_ctx, path); 127 err = lstat(buffer, stbuf); 128 if (err) { 129 goto err_out; 130 } 131 if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 132 /* Actual credentials are part of extended attrs */ 133 uid_t tmp_uid; 134 gid_t tmp_gid; 135 mode_t tmp_mode; 136 dev_t tmp_dev; 137 if (getxattr(buffer, "user.virtfs.uid", &tmp_uid, sizeof(uid_t)) > 0) { 138 stbuf->st_uid = le32_to_cpu(tmp_uid); 139 } 140 if (getxattr(buffer, "user.virtfs.gid", &tmp_gid, sizeof(gid_t)) > 0) { 141 stbuf->st_gid = le32_to_cpu(tmp_gid); 142 } 143 if (getxattr(buffer, "user.virtfs.mode", 144 &tmp_mode, sizeof(mode_t)) > 0) { 145 stbuf->st_mode = le32_to_cpu(tmp_mode); 146 } 147 if (getxattr(buffer, "user.virtfs.rdev", &tmp_dev, sizeof(dev_t)) > 0) { 148 stbuf->st_rdev = le64_to_cpu(tmp_dev); 149 } 150 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 151 local_mapped_file_attr(fs_ctx, path, stbuf); 152 } 153 154 err_out: 155 g_free(buffer); 156 return err; 157 } 158 159 static int local_create_mapped_attr_dir(FsContext *ctx, const char *path) 160 { 161 int err; 162 char *attr_dir; 163 char *tmp_path = g_strdup(path); 164 165 attr_dir = g_strdup_printf("%s/%s/%s", 166 ctx->fs_root, dirname(tmp_path), VIRTFS_META_DIR); 167 168 err = mkdir(attr_dir, 0700); 169 if (err < 0 && errno == EEXIST) { 170 err = 0; 171 } 172 g_free(attr_dir); 173 g_free(tmp_path); 174 return err; 175 } 176 177 static int local_set_mapped_file_attr(FsContext *ctx, 178 const char *path, FsCred *credp) 179 { 180 FILE *fp; 181 int ret = 0; 182 char buf[ATTR_MAX]; 183 char *attr_path; 184 int uid = -1, gid = -1, mode = -1, rdev = -1; 185 186 attr_path = local_mapped_attr_path(ctx, path); 187 fp = local_fopen(attr_path, "r"); 188 if (!fp) { 189 goto create_map_file; 190 } 191 memset(buf, 0, ATTR_MAX); 192 while (fgets(buf, ATTR_MAX, fp)) { 193 if (!strncmp(buf, "virtfs.uid", 10)) { 194 uid = atoi(buf+11); 195 } else if (!strncmp(buf, "virtfs.gid", 10)) { 196 gid = atoi(buf+11); 197 } else if (!strncmp(buf, "virtfs.mode", 11)) { 198 mode = atoi(buf+12); 199 } else if (!strncmp(buf, "virtfs.rdev", 11)) { 200 rdev = atoi(buf+12); 201 } 202 memset(buf, 0, ATTR_MAX); 203 } 204 fclose(fp); 205 goto update_map_file; 206 207 create_map_file: 208 ret = local_create_mapped_attr_dir(ctx, path); 209 if (ret < 0) { 210 goto err_out; 211 } 212 213 update_map_file: 214 fp = local_fopen(attr_path, "w"); 215 if (!fp) { 216 ret = -1; 217 goto err_out; 218 } 219 220 if (credp->fc_uid != -1) { 221 uid = credp->fc_uid; 222 } 223 if (credp->fc_gid != -1) { 224 gid = credp->fc_gid; 225 } 226 if (credp->fc_mode != -1) { 227 mode = credp->fc_mode; 228 } 229 if (credp->fc_rdev != -1) { 230 rdev = credp->fc_rdev; 231 } 232 233 234 if (uid != -1) { 235 fprintf(fp, "virtfs.uid=%d\n", uid); 236 } 237 if (gid != -1) { 238 fprintf(fp, "virtfs.gid=%d\n", gid); 239 } 240 if (mode != -1) { 241 fprintf(fp, "virtfs.mode=%d\n", mode); 242 } 243 if (rdev != -1) { 244 fprintf(fp, "virtfs.rdev=%d\n", rdev); 245 } 246 fclose(fp); 247 248 err_out: 249 g_free(attr_path); 250 return ret; 251 } 252 253 static int local_set_xattr(const char *path, FsCred *credp) 254 { 255 int err; 256 257 if (credp->fc_uid != -1) { 258 uint32_t tmp_uid = cpu_to_le32(credp->fc_uid); 259 err = setxattr(path, "user.virtfs.uid", &tmp_uid, sizeof(uid_t), 0); 260 if (err) { 261 return err; 262 } 263 } 264 if (credp->fc_gid != -1) { 265 uint32_t tmp_gid = cpu_to_le32(credp->fc_gid); 266 err = setxattr(path, "user.virtfs.gid", &tmp_gid, sizeof(gid_t), 0); 267 if (err) { 268 return err; 269 } 270 } 271 if (credp->fc_mode != -1) { 272 uint32_t tmp_mode = cpu_to_le32(credp->fc_mode); 273 err = setxattr(path, "user.virtfs.mode", &tmp_mode, sizeof(mode_t), 0); 274 if (err) { 275 return err; 276 } 277 } 278 if (credp->fc_rdev != -1) { 279 uint64_t tmp_rdev = cpu_to_le64(credp->fc_rdev); 280 err = setxattr(path, "user.virtfs.rdev", &tmp_rdev, sizeof(dev_t), 0); 281 if (err) { 282 return err; 283 } 284 } 285 return 0; 286 } 287 288 static int local_post_create_passthrough(FsContext *fs_ctx, const char *path, 289 FsCred *credp) 290 { 291 char *buffer; 292 293 buffer = rpath(fs_ctx, path); 294 if (lchown(buffer, credp->fc_uid, credp->fc_gid) < 0) { 295 /* 296 * If we fail to change ownership and if we are 297 * using security model none. Ignore the error 298 */ 299 if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) { 300 goto err; 301 } 302 } 303 304 if (chmod(buffer, credp->fc_mode & 07777) < 0) { 305 goto err; 306 } 307 308 g_free(buffer); 309 return 0; 310 err: 311 g_free(buffer); 312 return -1; 313 } 314 315 static ssize_t local_readlink(FsContext *fs_ctx, V9fsPath *fs_path, 316 char *buf, size_t bufsz) 317 { 318 ssize_t tsize = -1; 319 char *buffer; 320 char *path = fs_path->data; 321 322 if ((fs_ctx->export_flags & V9FS_SM_MAPPED) || 323 (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE)) { 324 int fd; 325 buffer = rpath(fs_ctx, path); 326 fd = open(buffer, O_RDONLY | O_NOFOLLOW); 327 g_free(buffer); 328 if (fd == -1) { 329 return -1; 330 } 331 do { 332 tsize = read(fd, (void *)buf, bufsz); 333 } while (tsize == -1 && errno == EINTR); 334 close(fd); 335 } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || 336 (fs_ctx->export_flags & V9FS_SM_NONE)) { 337 buffer = rpath(fs_ctx, path); 338 tsize = readlink(buffer, buf, bufsz); 339 g_free(buffer); 340 } 341 return tsize; 342 } 343 344 static int local_close(FsContext *ctx, V9fsFidOpenState *fs) 345 { 346 return close(fs->fd); 347 } 348 349 static int local_closedir(FsContext *ctx, V9fsFidOpenState *fs) 350 { 351 return closedir(fs->dir.stream); 352 } 353 354 static int local_open(FsContext *ctx, V9fsPath *fs_path, 355 int flags, V9fsFidOpenState *fs) 356 { 357 char *buffer; 358 char *path = fs_path->data; 359 360 buffer = rpath(ctx, path); 361 fs->fd = open(buffer, flags | O_NOFOLLOW); 362 g_free(buffer); 363 return fs->fd; 364 } 365 366 static int local_opendir(FsContext *ctx, 367 V9fsPath *fs_path, V9fsFidOpenState *fs) 368 { 369 char *buffer; 370 char *path = fs_path->data; 371 372 buffer = rpath(ctx, path); 373 fs->dir.stream = opendir(buffer); 374 g_free(buffer); 375 if (!fs->dir.stream) { 376 return -1; 377 } 378 return 0; 379 } 380 381 static void local_rewinddir(FsContext *ctx, V9fsFidOpenState *fs) 382 { 383 rewinddir(fs->dir.stream); 384 } 385 386 static off_t local_telldir(FsContext *ctx, V9fsFidOpenState *fs) 387 { 388 return telldir(fs->dir.stream); 389 } 390 391 static struct dirent *local_readdir(FsContext *ctx, V9fsFidOpenState *fs) 392 { 393 struct dirent *entry; 394 395 again: 396 entry = readdir(fs->dir.stream); 397 if (!entry) { 398 return NULL; 399 } 400 401 if (ctx->export_flags & V9FS_SM_MAPPED) { 402 entry->d_type = DT_UNKNOWN; 403 } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { 404 if (!strcmp(entry->d_name, VIRTFS_META_DIR)) { 405 /* skp the meta data directory */ 406 goto again; 407 } 408 entry->d_type = DT_UNKNOWN; 409 } 410 411 return entry; 412 } 413 414 static void local_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off) 415 { 416 seekdir(fs->dir.stream, off); 417 } 418 419 static ssize_t local_preadv(FsContext *ctx, V9fsFidOpenState *fs, 420 const struct iovec *iov, 421 int iovcnt, off_t offset) 422 { 423 #ifdef CONFIG_PREADV 424 return preadv(fs->fd, iov, iovcnt, offset); 425 #else 426 int err = lseek(fs->fd, offset, SEEK_SET); 427 if (err == -1) { 428 return err; 429 } else { 430 return readv(fs->fd, iov, iovcnt); 431 } 432 #endif 433 } 434 435 static ssize_t local_pwritev(FsContext *ctx, V9fsFidOpenState *fs, 436 const struct iovec *iov, 437 int iovcnt, off_t offset) 438 { 439 ssize_t ret; 440 #ifdef CONFIG_PREADV 441 ret = pwritev(fs->fd, iov, iovcnt, offset); 442 #else 443 int err = lseek(fs->fd, offset, SEEK_SET); 444 if (err == -1) { 445 return err; 446 } else { 447 ret = writev(fs->fd, iov, iovcnt); 448 } 449 #endif 450 #ifdef CONFIG_SYNC_FILE_RANGE 451 if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) { 452 /* 453 * Initiate a writeback. This is not a data integrity sync. 454 * We want to ensure that we don't leave dirty pages in the cache 455 * after write when writeout=immediate is sepcified. 456 */ 457 sync_file_range(fs->fd, offset, ret, 458 SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE); 459 } 460 #endif 461 return ret; 462 } 463 464 static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp) 465 { 466 char *buffer; 467 int ret = -1; 468 char *path = fs_path->data; 469 470 if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 471 buffer = rpath(fs_ctx, path); 472 ret = local_set_xattr(buffer, credp); 473 g_free(buffer); 474 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 475 return local_set_mapped_file_attr(fs_ctx, path, credp); 476 } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || 477 (fs_ctx->export_flags & V9FS_SM_NONE)) { 478 buffer = rpath(fs_ctx, path); 479 ret = chmod(buffer, credp->fc_mode); 480 g_free(buffer); 481 } 482 return ret; 483 } 484 485 static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path, 486 const char *name, FsCred *credp) 487 { 488 char *path; 489 int err = -1; 490 int serrno = 0; 491 V9fsString fullname; 492 char *buffer = NULL; 493 494 v9fs_string_init(&fullname); 495 v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name); 496 path = fullname.data; 497 498 /* Determine the security model */ 499 if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 500 buffer = rpath(fs_ctx, path); 501 err = mknod(buffer, SM_LOCAL_MODE_BITS|S_IFREG, 0); 502 if (err == -1) { 503 goto out; 504 } 505 err = local_set_xattr(buffer, credp); 506 if (err == -1) { 507 serrno = errno; 508 goto err_end; 509 } 510 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 511 512 buffer = rpath(fs_ctx, path); 513 err = mknod(buffer, SM_LOCAL_MODE_BITS|S_IFREG, 0); 514 if (err == -1) { 515 goto out; 516 } 517 err = local_set_mapped_file_attr(fs_ctx, path, credp); 518 if (err == -1) { 519 serrno = errno; 520 goto err_end; 521 } 522 } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || 523 (fs_ctx->export_flags & V9FS_SM_NONE)) { 524 buffer = rpath(fs_ctx, path); 525 err = mknod(buffer, credp->fc_mode, credp->fc_rdev); 526 if (err == -1) { 527 goto out; 528 } 529 err = local_post_create_passthrough(fs_ctx, path, credp); 530 if (err == -1) { 531 serrno = errno; 532 goto err_end; 533 } 534 } 535 goto out; 536 537 err_end: 538 remove(buffer); 539 errno = serrno; 540 out: 541 g_free(buffer); 542 v9fs_string_free(&fullname); 543 return err; 544 } 545 546 static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path, 547 const char *name, FsCred *credp) 548 { 549 char *path; 550 int err = -1; 551 int serrno = 0; 552 V9fsString fullname; 553 char *buffer = NULL; 554 555 v9fs_string_init(&fullname); 556 v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name); 557 path = fullname.data; 558 559 /* Determine the security model */ 560 if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 561 buffer = rpath(fs_ctx, path); 562 err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS); 563 if (err == -1) { 564 goto out; 565 } 566 credp->fc_mode = credp->fc_mode|S_IFDIR; 567 err = local_set_xattr(buffer, credp); 568 if (err == -1) { 569 serrno = errno; 570 goto err_end; 571 } 572 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 573 buffer = rpath(fs_ctx, path); 574 err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS); 575 if (err == -1) { 576 goto out; 577 } 578 credp->fc_mode = credp->fc_mode|S_IFDIR; 579 err = local_set_mapped_file_attr(fs_ctx, path, credp); 580 if (err == -1) { 581 serrno = errno; 582 goto err_end; 583 } 584 } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || 585 (fs_ctx->export_flags & V9FS_SM_NONE)) { 586 buffer = rpath(fs_ctx, path); 587 err = mkdir(buffer, credp->fc_mode); 588 if (err == -1) { 589 goto out; 590 } 591 err = local_post_create_passthrough(fs_ctx, path, credp); 592 if (err == -1) { 593 serrno = errno; 594 goto err_end; 595 } 596 } 597 goto out; 598 599 err_end: 600 remove(buffer); 601 errno = serrno; 602 out: 603 g_free(buffer); 604 v9fs_string_free(&fullname); 605 return err; 606 } 607 608 static int local_fstat(FsContext *fs_ctx, int fid_type, 609 V9fsFidOpenState *fs, struct stat *stbuf) 610 { 611 int err, fd; 612 613 if (fid_type == P9_FID_DIR) { 614 fd = dirfd(fs->dir.stream); 615 } else { 616 fd = fs->fd; 617 } 618 619 err = fstat(fd, stbuf); 620 if (err) { 621 return err; 622 } 623 if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 624 /* Actual credentials are part of extended attrs */ 625 uid_t tmp_uid; 626 gid_t tmp_gid; 627 mode_t tmp_mode; 628 dev_t tmp_dev; 629 630 if (fgetxattr(fd, "user.virtfs.uid", &tmp_uid, sizeof(uid_t)) > 0) { 631 stbuf->st_uid = le32_to_cpu(tmp_uid); 632 } 633 if (fgetxattr(fd, "user.virtfs.gid", &tmp_gid, sizeof(gid_t)) > 0) { 634 stbuf->st_gid = le32_to_cpu(tmp_gid); 635 } 636 if (fgetxattr(fd, "user.virtfs.mode", &tmp_mode, sizeof(mode_t)) > 0) { 637 stbuf->st_mode = le32_to_cpu(tmp_mode); 638 } 639 if (fgetxattr(fd, "user.virtfs.rdev", &tmp_dev, sizeof(dev_t)) > 0) { 640 stbuf->st_rdev = le64_to_cpu(tmp_dev); 641 } 642 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 643 errno = EOPNOTSUPP; 644 return -1; 645 } 646 return err; 647 } 648 649 static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name, 650 int flags, FsCred *credp, V9fsFidOpenState *fs) 651 { 652 char *path; 653 int fd = -1; 654 int err = -1; 655 int serrno = 0; 656 V9fsString fullname; 657 char *buffer = NULL; 658 659 /* 660 * Mark all the open to not follow symlinks 661 */ 662 flags |= O_NOFOLLOW; 663 664 v9fs_string_init(&fullname); 665 v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name); 666 path = fullname.data; 667 668 /* Determine the security model */ 669 if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 670 buffer = rpath(fs_ctx, path); 671 fd = open(buffer, flags, SM_LOCAL_MODE_BITS); 672 if (fd == -1) { 673 err = fd; 674 goto out; 675 } 676 credp->fc_mode = credp->fc_mode|S_IFREG; 677 /* Set cleint credentials in xattr */ 678 err = local_set_xattr(buffer, credp); 679 if (err == -1) { 680 serrno = errno; 681 goto err_end; 682 } 683 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 684 buffer = rpath(fs_ctx, path); 685 fd = open(buffer, flags, SM_LOCAL_MODE_BITS); 686 if (fd == -1) { 687 err = fd; 688 goto out; 689 } 690 credp->fc_mode = credp->fc_mode|S_IFREG; 691 /* Set client credentials in .virtfs_metadata directory files */ 692 err = local_set_mapped_file_attr(fs_ctx, path, credp); 693 if (err == -1) { 694 serrno = errno; 695 goto err_end; 696 } 697 } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || 698 (fs_ctx->export_flags & V9FS_SM_NONE)) { 699 buffer = rpath(fs_ctx, path); 700 fd = open(buffer, flags, credp->fc_mode); 701 if (fd == -1) { 702 err = fd; 703 goto out; 704 } 705 err = local_post_create_passthrough(fs_ctx, path, credp); 706 if (err == -1) { 707 serrno = errno; 708 goto err_end; 709 } 710 } 711 err = fd; 712 fs->fd = fd; 713 goto out; 714 715 err_end: 716 close(fd); 717 remove(buffer); 718 errno = serrno; 719 out: 720 g_free(buffer); 721 v9fs_string_free(&fullname); 722 return err; 723 } 724 725 726 static int local_symlink(FsContext *fs_ctx, const char *oldpath, 727 V9fsPath *dir_path, const char *name, FsCred *credp) 728 { 729 int err = -1; 730 int serrno = 0; 731 char *newpath; 732 V9fsString fullname; 733 char *buffer = NULL; 734 735 v9fs_string_init(&fullname); 736 v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name); 737 newpath = fullname.data; 738 739 /* Determine the security model */ 740 if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 741 int fd; 742 ssize_t oldpath_size, write_size; 743 buffer = rpath(fs_ctx, newpath); 744 fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS); 745 if (fd == -1) { 746 err = fd; 747 goto out; 748 } 749 /* Write the oldpath (target) to the file. */ 750 oldpath_size = strlen(oldpath); 751 do { 752 write_size = write(fd, (void *)oldpath, oldpath_size); 753 } while (write_size == -1 && errno == EINTR); 754 755 if (write_size != oldpath_size) { 756 serrno = errno; 757 close(fd); 758 err = -1; 759 goto err_end; 760 } 761 close(fd); 762 /* Set cleint credentials in symlink's xattr */ 763 credp->fc_mode = credp->fc_mode|S_IFLNK; 764 err = local_set_xattr(buffer, credp); 765 if (err == -1) { 766 serrno = errno; 767 goto err_end; 768 } 769 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 770 int fd; 771 ssize_t oldpath_size, write_size; 772 buffer = rpath(fs_ctx, newpath); 773 fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS); 774 if (fd == -1) { 775 err = fd; 776 goto out; 777 } 778 /* Write the oldpath (target) to the file. */ 779 oldpath_size = strlen(oldpath); 780 do { 781 write_size = write(fd, (void *)oldpath, oldpath_size); 782 } while (write_size == -1 && errno == EINTR); 783 784 if (write_size != oldpath_size) { 785 serrno = errno; 786 close(fd); 787 err = -1; 788 goto err_end; 789 } 790 close(fd); 791 /* Set cleint credentials in symlink's xattr */ 792 credp->fc_mode = credp->fc_mode|S_IFLNK; 793 err = local_set_mapped_file_attr(fs_ctx, newpath, credp); 794 if (err == -1) { 795 serrno = errno; 796 goto err_end; 797 } 798 } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || 799 (fs_ctx->export_flags & V9FS_SM_NONE)) { 800 buffer = rpath(fs_ctx, newpath); 801 err = symlink(oldpath, buffer); 802 if (err) { 803 goto out; 804 } 805 err = lchown(buffer, credp->fc_uid, credp->fc_gid); 806 if (err == -1) { 807 /* 808 * If we fail to change ownership and if we are 809 * using security model none. Ignore the error 810 */ 811 if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) { 812 serrno = errno; 813 goto err_end; 814 } else 815 err = 0; 816 } 817 } 818 goto out; 819 820 err_end: 821 remove(buffer); 822 errno = serrno; 823 out: 824 g_free(buffer); 825 v9fs_string_free(&fullname); 826 return err; 827 } 828 829 static int local_link(FsContext *ctx, V9fsPath *oldpath, 830 V9fsPath *dirpath, const char *name) 831 { 832 int ret; 833 V9fsString newpath; 834 char *buffer, *buffer1; 835 836 v9fs_string_init(&newpath); 837 v9fs_string_sprintf(&newpath, "%s/%s", dirpath->data, name); 838 839 buffer = rpath(ctx, oldpath->data); 840 buffer1 = rpath(ctx, newpath.data); 841 ret = link(buffer, buffer1); 842 g_free(buffer); 843 g_free(buffer1); 844 845 /* now link the virtfs_metadata files */ 846 if (!ret && (ctx->export_flags & V9FS_SM_MAPPED_FILE)) { 847 /* Link the .virtfs_metadata files. Create the metada directory */ 848 ret = local_create_mapped_attr_dir(ctx, newpath.data); 849 if (ret < 0) { 850 goto err_out; 851 } 852 buffer = local_mapped_attr_path(ctx, oldpath->data); 853 buffer1 = local_mapped_attr_path(ctx, newpath.data); 854 ret = link(buffer, buffer1); 855 g_free(buffer); 856 g_free(buffer1); 857 if (ret < 0 && errno != ENOENT) { 858 goto err_out; 859 } 860 } 861 err_out: 862 v9fs_string_free(&newpath); 863 return ret; 864 } 865 866 static int local_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size) 867 { 868 char *buffer; 869 int ret; 870 char *path = fs_path->data; 871 872 buffer = rpath(ctx, path); 873 ret = truncate(buffer, size); 874 g_free(buffer); 875 return ret; 876 } 877 878 static int local_rename(FsContext *ctx, const char *oldpath, 879 const char *newpath) 880 { 881 int err; 882 char *buffer, *buffer1; 883 884 if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { 885 err = local_create_mapped_attr_dir(ctx, newpath); 886 if (err < 0) { 887 return err; 888 } 889 /* rename the .virtfs_metadata files */ 890 buffer = local_mapped_attr_path(ctx, oldpath); 891 buffer1 = local_mapped_attr_path(ctx, newpath); 892 err = rename(buffer, buffer1); 893 g_free(buffer); 894 g_free(buffer1); 895 if (err < 0 && errno != ENOENT) { 896 return err; 897 } 898 } 899 900 buffer = rpath(ctx, oldpath); 901 buffer1 = rpath(ctx, newpath); 902 err = rename(buffer, buffer1); 903 g_free(buffer); 904 g_free(buffer1); 905 return err; 906 } 907 908 static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp) 909 { 910 char *buffer; 911 int ret = -1; 912 char *path = fs_path->data; 913 914 if ((credp->fc_uid == -1 && credp->fc_gid == -1) || 915 (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || 916 (fs_ctx->export_flags & V9FS_SM_NONE)) { 917 buffer = rpath(fs_ctx, path); 918 ret = lchown(buffer, credp->fc_uid, credp->fc_gid); 919 g_free(buffer); 920 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 921 buffer = rpath(fs_ctx, path); 922 ret = local_set_xattr(buffer, credp); 923 g_free(buffer); 924 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 925 return local_set_mapped_file_attr(fs_ctx, path, credp); 926 } 927 return ret; 928 } 929 930 static int local_utimensat(FsContext *s, V9fsPath *fs_path, 931 const struct timespec *buf) 932 { 933 char *buffer; 934 int ret; 935 char *path = fs_path->data; 936 937 buffer = rpath(s, path); 938 ret = qemu_utimens(buffer, buf); 939 g_free(buffer); 940 return ret; 941 } 942 943 static int local_remove(FsContext *ctx, const char *path) 944 { 945 int err; 946 struct stat stbuf; 947 char *buffer; 948 949 if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { 950 buffer = rpath(ctx, path); 951 err = lstat(buffer, &stbuf); 952 g_free(buffer); 953 if (err) { 954 goto err_out; 955 } 956 /* 957 * If directory remove .virtfs_metadata contained in the 958 * directory 959 */ 960 if (S_ISDIR(stbuf.st_mode)) { 961 buffer = g_strdup_printf("%s/%s/%s", ctx->fs_root, 962 path, VIRTFS_META_DIR); 963 err = remove(buffer); 964 g_free(buffer); 965 if (err < 0 && errno != ENOENT) { 966 /* 967 * We didn't had the .virtfs_metadata file. May be file created 968 * in non-mapped mode ?. Ignore ENOENT. 969 */ 970 goto err_out; 971 } 972 } 973 /* 974 * Now remove the name from parent directory 975 * .virtfs_metadata directory 976 */ 977 buffer = local_mapped_attr_path(ctx, path); 978 err = remove(buffer); 979 g_free(buffer); 980 if (err < 0 && errno != ENOENT) { 981 /* 982 * We didn't had the .virtfs_metadata file. May be file created 983 * in non-mapped mode ?. Ignore ENOENT. 984 */ 985 goto err_out; 986 } 987 } 988 989 buffer = rpath(ctx, path); 990 err = remove(buffer); 991 g_free(buffer); 992 err_out: 993 return err; 994 } 995 996 static int local_fsync(FsContext *ctx, int fid_type, 997 V9fsFidOpenState *fs, int datasync) 998 { 999 int fd; 1000 1001 if (fid_type == P9_FID_DIR) { 1002 fd = dirfd(fs->dir.stream); 1003 } else { 1004 fd = fs->fd; 1005 } 1006 1007 if (datasync) { 1008 return qemu_fdatasync(fd); 1009 } else { 1010 return fsync(fd); 1011 } 1012 } 1013 1014 static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf) 1015 { 1016 char *buffer; 1017 int ret; 1018 char *path = fs_path->data; 1019 1020 buffer = rpath(s, path); 1021 ret = statfs(buffer, stbuf); 1022 g_free(buffer); 1023 return ret; 1024 } 1025 1026 static ssize_t local_lgetxattr(FsContext *ctx, V9fsPath *fs_path, 1027 const char *name, void *value, size_t size) 1028 { 1029 char *path = fs_path->data; 1030 1031 return v9fs_get_xattr(ctx, path, name, value, size); 1032 } 1033 1034 static ssize_t local_llistxattr(FsContext *ctx, V9fsPath *fs_path, 1035 void *value, size_t size) 1036 { 1037 char *path = fs_path->data; 1038 1039 return v9fs_list_xattr(ctx, path, value, size); 1040 } 1041 1042 static int local_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name, 1043 void *value, size_t size, int flags) 1044 { 1045 char *path = fs_path->data; 1046 1047 return v9fs_set_xattr(ctx, path, name, value, size, flags); 1048 } 1049 1050 static int local_lremovexattr(FsContext *ctx, V9fsPath *fs_path, 1051 const char *name) 1052 { 1053 char *path = fs_path->data; 1054 1055 return v9fs_remove_xattr(ctx, path, name); 1056 } 1057 1058 static int local_name_to_path(FsContext *ctx, V9fsPath *dir_path, 1059 const char *name, V9fsPath *target) 1060 { 1061 if (dir_path) { 1062 v9fs_path_sprintf(target, "%s/%s", dir_path->data, name); 1063 } else { 1064 v9fs_path_sprintf(target, "%s", name); 1065 } 1066 return 0; 1067 } 1068 1069 static int local_renameat(FsContext *ctx, V9fsPath *olddir, 1070 const char *old_name, V9fsPath *newdir, 1071 const char *new_name) 1072 { 1073 int ret; 1074 V9fsString old_full_name, new_full_name; 1075 1076 v9fs_string_init(&old_full_name); 1077 v9fs_string_init(&new_full_name); 1078 1079 v9fs_string_sprintf(&old_full_name, "%s/%s", olddir->data, old_name); 1080 v9fs_string_sprintf(&new_full_name, "%s/%s", newdir->data, new_name); 1081 1082 ret = local_rename(ctx, old_full_name.data, new_full_name.data); 1083 v9fs_string_free(&old_full_name); 1084 v9fs_string_free(&new_full_name); 1085 return ret; 1086 } 1087 1088 static int local_unlinkat(FsContext *ctx, V9fsPath *dir, 1089 const char *name, int flags) 1090 { 1091 int ret; 1092 V9fsString fullname; 1093 char *buffer; 1094 1095 v9fs_string_init(&fullname); 1096 1097 v9fs_string_sprintf(&fullname, "%s/%s", dir->data, name); 1098 if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { 1099 if (flags == AT_REMOVEDIR) { 1100 /* 1101 * If directory remove .virtfs_metadata contained in the 1102 * directory 1103 */ 1104 buffer = g_strdup_printf("%s/%s/%s", ctx->fs_root, 1105 fullname.data, VIRTFS_META_DIR); 1106 ret = remove(buffer); 1107 g_free(buffer); 1108 if (ret < 0 && errno != ENOENT) { 1109 /* 1110 * We didn't had the .virtfs_metadata file. May be file created 1111 * in non-mapped mode ?. Ignore ENOENT. 1112 */ 1113 goto err_out; 1114 } 1115 } 1116 /* 1117 * Now remove the name from parent directory 1118 * .virtfs_metadata directory. 1119 */ 1120 buffer = local_mapped_attr_path(ctx, fullname.data); 1121 ret = remove(buffer); 1122 g_free(buffer); 1123 if (ret < 0 && errno != ENOENT) { 1124 /* 1125 * We didn't had the .virtfs_metadata file. May be file created 1126 * in non-mapped mode ?. Ignore ENOENT. 1127 */ 1128 goto err_out; 1129 } 1130 } 1131 /* Remove the name finally */ 1132 buffer = rpath(ctx, fullname.data); 1133 ret = remove(buffer); 1134 g_free(buffer); 1135 1136 err_out: 1137 v9fs_string_free(&fullname); 1138 return ret; 1139 } 1140 1141 static int local_ioc_getversion(FsContext *ctx, V9fsPath *path, 1142 mode_t st_mode, uint64_t *st_gen) 1143 { 1144 #ifdef FS_IOC_GETVERSION 1145 int err; 1146 V9fsFidOpenState fid_open; 1147 1148 /* 1149 * Do not try to open special files like device nodes, fifos etc 1150 * We can get fd for regular files and directories only 1151 */ 1152 if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) { 1153 errno = ENOTTY; 1154 return -1; 1155 } 1156 err = local_open(ctx, path, O_RDONLY, &fid_open); 1157 if (err < 0) { 1158 return err; 1159 } 1160 err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen); 1161 local_close(ctx, &fid_open); 1162 return err; 1163 #else 1164 errno = ENOTTY; 1165 return -1; 1166 #endif 1167 } 1168 1169 static int local_init(FsContext *ctx) 1170 { 1171 int err = 0; 1172 struct statfs stbuf; 1173 1174 if (ctx->export_flags & V9FS_SM_PASSTHROUGH) { 1175 ctx->xops = passthrough_xattr_ops; 1176 } else if (ctx->export_flags & V9FS_SM_MAPPED) { 1177 ctx->xops = mapped_xattr_ops; 1178 } else if (ctx->export_flags & V9FS_SM_NONE) { 1179 ctx->xops = none_xattr_ops; 1180 } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { 1181 /* 1182 * xattr operation for mapped-file and passthrough 1183 * remain same. 1184 */ 1185 ctx->xops = passthrough_xattr_ops; 1186 } 1187 ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT; 1188 #ifdef FS_IOC_GETVERSION 1189 /* 1190 * use ioc_getversion only if the iocl is definied 1191 */ 1192 err = statfs(ctx->fs_root, &stbuf); 1193 if (!err) { 1194 switch (stbuf.f_type) { 1195 case EXT2_SUPER_MAGIC: 1196 case BTRFS_SUPER_MAGIC: 1197 case REISERFS_SUPER_MAGIC: 1198 case XFS_SUPER_MAGIC: 1199 ctx->exops.get_st_gen = local_ioc_getversion; 1200 break; 1201 } 1202 } 1203 #endif 1204 return err; 1205 } 1206 1207 static int local_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse) 1208 { 1209 const char *sec_model = qemu_opt_get(opts, "security_model"); 1210 const char *path = qemu_opt_get(opts, "path"); 1211 1212 if (!sec_model) { 1213 error_report("Security model not specified, local fs needs security model"); 1214 error_printf("valid options are:" 1215 "\tsecurity_model=[passthrough|mapped-xattr|mapped-file|none]\n"); 1216 return -1; 1217 } 1218 1219 if (!strcmp(sec_model, "passthrough")) { 1220 fse->export_flags |= V9FS_SM_PASSTHROUGH; 1221 } else if (!strcmp(sec_model, "mapped") || 1222 !strcmp(sec_model, "mapped-xattr")) { 1223 fse->export_flags |= V9FS_SM_MAPPED; 1224 } else if (!strcmp(sec_model, "none")) { 1225 fse->export_flags |= V9FS_SM_NONE; 1226 } else if (!strcmp(sec_model, "mapped-file")) { 1227 fse->export_flags |= V9FS_SM_MAPPED_FILE; 1228 } else { 1229 error_report("Invalid security model %s specified", sec_model); 1230 error_printf("valid options are:" 1231 "\t[passthrough|mapped-xattr|mapped-file|none]\n"); 1232 return -1; 1233 } 1234 1235 if (!path) { 1236 error_report("fsdev: No path specified"); 1237 return -1; 1238 } 1239 fse->path = g_strdup(path); 1240 1241 return 0; 1242 } 1243 1244 FileOperations local_ops = { 1245 .parse_opts = local_parse_opts, 1246 .init = local_init, 1247 .lstat = local_lstat, 1248 .readlink = local_readlink, 1249 .close = local_close, 1250 .closedir = local_closedir, 1251 .open = local_open, 1252 .opendir = local_opendir, 1253 .rewinddir = local_rewinddir, 1254 .telldir = local_telldir, 1255 .readdir = local_readdir, 1256 .seekdir = local_seekdir, 1257 .preadv = local_preadv, 1258 .pwritev = local_pwritev, 1259 .chmod = local_chmod, 1260 .mknod = local_mknod, 1261 .mkdir = local_mkdir, 1262 .fstat = local_fstat, 1263 .open2 = local_open2, 1264 .symlink = local_symlink, 1265 .link = local_link, 1266 .truncate = local_truncate, 1267 .rename = local_rename, 1268 .chown = local_chown, 1269 .utimensat = local_utimensat, 1270 .remove = local_remove, 1271 .fsync = local_fsync, 1272 .statfs = local_statfs, 1273 .lgetxattr = local_lgetxattr, 1274 .llistxattr = local_llistxattr, 1275 .lsetxattr = local_lsetxattr, 1276 .lremovexattr = local_lremovexattr, 1277 .name_to_path = local_name_to_path, 1278 .renameat = local_renameat, 1279 .unlinkat = local_unlinkat, 1280 }; 1281