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); 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 = opendir(buffer); 374 g_free(buffer); 375 if (!fs->dir) { 376 return -1; 377 } 378 return 0; 379 } 380 381 static void local_rewinddir(FsContext *ctx, V9fsFidOpenState *fs) 382 { 383 rewinddir(fs->dir); 384 } 385 386 static off_t local_telldir(FsContext *ctx, V9fsFidOpenState *fs) 387 { 388 return telldir(fs->dir); 389 } 390 391 static int local_readdir_r(FsContext *ctx, V9fsFidOpenState *fs, 392 struct dirent *entry, 393 struct dirent **result) 394 { 395 int ret; 396 397 again: 398 ret = readdir_r(fs->dir, entry, result); 399 if (ctx->export_flags & V9FS_SM_MAPPED) { 400 entry->d_type = DT_UNKNOWN; 401 } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { 402 if (!ret && *result != NULL && 403 !strcmp(entry->d_name, VIRTFS_META_DIR)) { 404 /* skp the meta data directory */ 405 goto again; 406 } 407 entry->d_type = DT_UNKNOWN; 408 } 409 return ret; 410 } 411 412 static void local_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off) 413 { 414 seekdir(fs->dir, off); 415 } 416 417 static ssize_t local_preadv(FsContext *ctx, V9fsFidOpenState *fs, 418 const struct iovec *iov, 419 int iovcnt, off_t offset) 420 { 421 #ifdef CONFIG_PREADV 422 return preadv(fs->fd, iov, iovcnt, offset); 423 #else 424 int err = lseek(fs->fd, offset, SEEK_SET); 425 if (err == -1) { 426 return err; 427 } else { 428 return readv(fs->fd, iov, iovcnt); 429 } 430 #endif 431 } 432 433 static ssize_t local_pwritev(FsContext *ctx, V9fsFidOpenState *fs, 434 const struct iovec *iov, 435 int iovcnt, off_t offset) 436 { 437 ssize_t ret 438 ; 439 #ifdef CONFIG_PREADV 440 ret = pwritev(fs->fd, iov, iovcnt, offset); 441 #else 442 int err = lseek(fs->fd, offset, SEEK_SET); 443 if (err == -1) { 444 return err; 445 } else { 446 ret = writev(fs->fd, iov, iovcnt); 447 } 448 #endif 449 #ifdef CONFIG_SYNC_FILE_RANGE 450 if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) { 451 /* 452 * Initiate a writeback. This is not a data integrity sync. 453 * We want to ensure that we don't leave dirty pages in the cache 454 * after write when writeout=immediate is sepcified. 455 */ 456 sync_file_range(fs->fd, offset, ret, 457 SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE); 458 } 459 #endif 460 return ret; 461 } 462 463 static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp) 464 { 465 char *buffer; 466 int ret = -1; 467 char *path = fs_path->data; 468 469 if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 470 buffer = rpath(fs_ctx, path); 471 ret = local_set_xattr(buffer, credp); 472 g_free(buffer); 473 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 474 return local_set_mapped_file_attr(fs_ctx, path, credp); 475 } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || 476 (fs_ctx->export_flags & V9FS_SM_NONE)) { 477 buffer = rpath(fs_ctx, path); 478 ret = chmod(buffer, credp->fc_mode); 479 g_free(buffer); 480 } 481 return ret; 482 } 483 484 static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path, 485 const char *name, FsCred *credp) 486 { 487 char *path; 488 int err = -1; 489 int serrno = 0; 490 V9fsString fullname; 491 char *buffer = NULL; 492 493 v9fs_string_init(&fullname); 494 v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name); 495 path = fullname.data; 496 497 /* Determine the security model */ 498 if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 499 buffer = rpath(fs_ctx, path); 500 err = mknod(buffer, SM_LOCAL_MODE_BITS|S_IFREG, 0); 501 if (err == -1) { 502 goto out; 503 } 504 err = local_set_xattr(buffer, credp); 505 if (err == -1) { 506 serrno = errno; 507 goto err_end; 508 } 509 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 510 511 buffer = rpath(fs_ctx, path); 512 err = mknod(buffer, SM_LOCAL_MODE_BITS|S_IFREG, 0); 513 if (err == -1) { 514 goto out; 515 } 516 err = local_set_mapped_file_attr(fs_ctx, path, credp); 517 if (err == -1) { 518 serrno = errno; 519 goto err_end; 520 } 521 } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || 522 (fs_ctx->export_flags & V9FS_SM_NONE)) { 523 buffer = rpath(fs_ctx, path); 524 err = mknod(buffer, credp->fc_mode, credp->fc_rdev); 525 if (err == -1) { 526 goto out; 527 } 528 err = local_post_create_passthrough(fs_ctx, path, credp); 529 if (err == -1) { 530 serrno = errno; 531 goto err_end; 532 } 533 } 534 goto out; 535 536 err_end: 537 remove(buffer); 538 errno = serrno; 539 out: 540 g_free(buffer); 541 v9fs_string_free(&fullname); 542 return err; 543 } 544 545 static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path, 546 const char *name, FsCred *credp) 547 { 548 char *path; 549 int err = -1; 550 int serrno = 0; 551 V9fsString fullname; 552 char *buffer = NULL; 553 554 v9fs_string_init(&fullname); 555 v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name); 556 path = fullname.data; 557 558 /* Determine the security model */ 559 if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 560 buffer = rpath(fs_ctx, path); 561 err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS); 562 if (err == -1) { 563 goto out; 564 } 565 credp->fc_mode = credp->fc_mode|S_IFDIR; 566 err = local_set_xattr(buffer, credp); 567 if (err == -1) { 568 serrno = errno; 569 goto err_end; 570 } 571 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 572 buffer = rpath(fs_ctx, path); 573 err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS); 574 if (err == -1) { 575 goto out; 576 } 577 credp->fc_mode = credp->fc_mode|S_IFDIR; 578 err = local_set_mapped_file_attr(fs_ctx, path, credp); 579 if (err == -1) { 580 serrno = errno; 581 goto err_end; 582 } 583 } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || 584 (fs_ctx->export_flags & V9FS_SM_NONE)) { 585 buffer = rpath(fs_ctx, path); 586 err = mkdir(buffer, credp->fc_mode); 587 if (err == -1) { 588 goto out; 589 } 590 err = local_post_create_passthrough(fs_ctx, path, credp); 591 if (err == -1) { 592 serrno = errno; 593 goto err_end; 594 } 595 } 596 goto out; 597 598 err_end: 599 remove(buffer); 600 errno = serrno; 601 out: 602 g_free(buffer); 603 v9fs_string_free(&fullname); 604 return err; 605 } 606 607 static int local_fstat(FsContext *fs_ctx, int fid_type, 608 V9fsFidOpenState *fs, struct stat *stbuf) 609 { 610 int err, fd; 611 612 if (fid_type == P9_FID_DIR) { 613 fd = dirfd(fs->dir); 614 } else { 615 fd = fs->fd; 616 } 617 618 err = fstat(fd, stbuf); 619 if (err) { 620 return err; 621 } 622 if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 623 /* Actual credentials are part of extended attrs */ 624 uid_t tmp_uid; 625 gid_t tmp_gid; 626 mode_t tmp_mode; 627 dev_t tmp_dev; 628 629 if (fgetxattr(fd, "user.virtfs.uid", &tmp_uid, sizeof(uid_t)) > 0) { 630 stbuf->st_uid = le32_to_cpu(tmp_uid); 631 } 632 if (fgetxattr(fd, "user.virtfs.gid", &tmp_gid, sizeof(gid_t)) > 0) { 633 stbuf->st_gid = le32_to_cpu(tmp_gid); 634 } 635 if (fgetxattr(fd, "user.virtfs.mode", &tmp_mode, sizeof(mode_t)) > 0) { 636 stbuf->st_mode = le32_to_cpu(tmp_mode); 637 } 638 if (fgetxattr(fd, "user.virtfs.rdev", &tmp_dev, sizeof(dev_t)) > 0) { 639 stbuf->st_rdev = le64_to_cpu(tmp_dev); 640 } 641 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 642 errno = EOPNOTSUPP; 643 return -1; 644 } 645 return err; 646 } 647 648 static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name, 649 int flags, FsCred *credp, V9fsFidOpenState *fs) 650 { 651 char *path; 652 int fd = -1; 653 int err = -1; 654 int serrno = 0; 655 V9fsString fullname; 656 char *buffer = NULL; 657 658 /* 659 * Mark all the open to not follow symlinks 660 */ 661 flags |= O_NOFOLLOW; 662 663 v9fs_string_init(&fullname); 664 v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name); 665 path = fullname.data; 666 667 /* Determine the security model */ 668 if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 669 buffer = rpath(fs_ctx, path); 670 fd = open(buffer, flags, SM_LOCAL_MODE_BITS); 671 if (fd == -1) { 672 err = fd; 673 goto out; 674 } 675 credp->fc_mode = credp->fc_mode|S_IFREG; 676 /* Set cleint credentials in xattr */ 677 err = local_set_xattr(buffer, credp); 678 if (err == -1) { 679 serrno = errno; 680 goto err_end; 681 } 682 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 683 buffer = rpath(fs_ctx, path); 684 fd = open(buffer, flags, SM_LOCAL_MODE_BITS); 685 if (fd == -1) { 686 err = fd; 687 goto out; 688 } 689 credp->fc_mode = credp->fc_mode|S_IFREG; 690 /* Set client credentials in .virtfs_metadata directory files */ 691 err = local_set_mapped_file_attr(fs_ctx, path, credp); 692 if (err == -1) { 693 serrno = errno; 694 goto err_end; 695 } 696 } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || 697 (fs_ctx->export_flags & V9FS_SM_NONE)) { 698 buffer = rpath(fs_ctx, path); 699 fd = open(buffer, flags, credp->fc_mode); 700 if (fd == -1) { 701 err = fd; 702 goto out; 703 } 704 err = local_post_create_passthrough(fs_ctx, path, credp); 705 if (err == -1) { 706 serrno = errno; 707 goto err_end; 708 } 709 } 710 err = fd; 711 fs->fd = fd; 712 goto out; 713 714 err_end: 715 close(fd); 716 remove(buffer); 717 errno = serrno; 718 out: 719 g_free(buffer); 720 v9fs_string_free(&fullname); 721 return err; 722 } 723 724 725 static int local_symlink(FsContext *fs_ctx, const char *oldpath, 726 V9fsPath *dir_path, const char *name, FsCred *credp) 727 { 728 int err = -1; 729 int serrno = 0; 730 char *newpath; 731 V9fsString fullname; 732 char *buffer = NULL; 733 734 v9fs_string_init(&fullname); 735 v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name); 736 newpath = fullname.data; 737 738 /* Determine the security model */ 739 if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 740 int fd; 741 ssize_t oldpath_size, write_size; 742 buffer = rpath(fs_ctx, newpath); 743 fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS); 744 if (fd == -1) { 745 err = fd; 746 goto out; 747 } 748 /* Write the oldpath (target) to the file. */ 749 oldpath_size = strlen(oldpath); 750 do { 751 write_size = write(fd, (void *)oldpath, oldpath_size); 752 } while (write_size == -1 && errno == EINTR); 753 754 if (write_size != oldpath_size) { 755 serrno = errno; 756 close(fd); 757 err = -1; 758 goto err_end; 759 } 760 close(fd); 761 /* Set cleint credentials in symlink's xattr */ 762 credp->fc_mode = credp->fc_mode|S_IFLNK; 763 err = local_set_xattr(buffer, credp); 764 if (err == -1) { 765 serrno = errno; 766 goto err_end; 767 } 768 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 769 int fd; 770 ssize_t oldpath_size, write_size; 771 buffer = rpath(fs_ctx, newpath); 772 fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS); 773 if (fd == -1) { 774 err = fd; 775 goto out; 776 } 777 /* Write the oldpath (target) to the file. */ 778 oldpath_size = strlen(oldpath); 779 do { 780 write_size = write(fd, (void *)oldpath, oldpath_size); 781 } while (write_size == -1 && errno == EINTR); 782 783 if (write_size != oldpath_size) { 784 serrno = errno; 785 close(fd); 786 err = -1; 787 goto err_end; 788 } 789 close(fd); 790 /* Set cleint credentials in symlink's xattr */ 791 credp->fc_mode = credp->fc_mode|S_IFLNK; 792 err = local_set_mapped_file_attr(fs_ctx, newpath, credp); 793 if (err == -1) { 794 serrno = errno; 795 goto err_end; 796 } 797 } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || 798 (fs_ctx->export_flags & V9FS_SM_NONE)) { 799 buffer = rpath(fs_ctx, newpath); 800 err = symlink(oldpath, buffer); 801 if (err) { 802 goto out; 803 } 804 err = lchown(buffer, credp->fc_uid, credp->fc_gid); 805 if (err == -1) { 806 /* 807 * If we fail to change ownership and if we are 808 * using security model none. Ignore the error 809 */ 810 if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) { 811 serrno = errno; 812 goto err_end; 813 } else 814 err = 0; 815 } 816 } 817 goto out; 818 819 err_end: 820 remove(buffer); 821 errno = serrno; 822 out: 823 g_free(buffer); 824 v9fs_string_free(&fullname); 825 return err; 826 } 827 828 static int local_link(FsContext *ctx, V9fsPath *oldpath, 829 V9fsPath *dirpath, const char *name) 830 { 831 int ret; 832 V9fsString newpath; 833 char *buffer, *buffer1; 834 835 v9fs_string_init(&newpath); 836 v9fs_string_sprintf(&newpath, "%s/%s", dirpath->data, name); 837 838 buffer = rpath(ctx, oldpath->data); 839 buffer1 = rpath(ctx, newpath.data); 840 ret = link(buffer, buffer1); 841 g_free(buffer); 842 g_free(buffer1); 843 844 /* now link the virtfs_metadata files */ 845 if (!ret && (ctx->export_flags & V9FS_SM_MAPPED_FILE)) { 846 /* Link the .virtfs_metadata files. Create the metada directory */ 847 ret = local_create_mapped_attr_dir(ctx, newpath.data); 848 if (ret < 0) { 849 goto err_out; 850 } 851 buffer = local_mapped_attr_path(ctx, oldpath->data); 852 buffer1 = local_mapped_attr_path(ctx, newpath.data); 853 ret = link(buffer, buffer1); 854 g_free(buffer); 855 g_free(buffer1); 856 if (ret < 0 && errno != ENOENT) { 857 goto err_out; 858 } 859 } 860 err_out: 861 v9fs_string_free(&newpath); 862 return ret; 863 } 864 865 static int local_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size) 866 { 867 char *buffer; 868 int ret; 869 char *path = fs_path->data; 870 871 buffer = rpath(ctx, path); 872 ret = truncate(buffer, size); 873 g_free(buffer); 874 return ret; 875 } 876 877 static int local_rename(FsContext *ctx, const char *oldpath, 878 const char *newpath) 879 { 880 int err; 881 char *buffer, *buffer1; 882 883 if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { 884 err = local_create_mapped_attr_dir(ctx, newpath); 885 if (err < 0) { 886 return err; 887 } 888 /* rename the .virtfs_metadata files */ 889 buffer = local_mapped_attr_path(ctx, oldpath); 890 buffer1 = local_mapped_attr_path(ctx, newpath); 891 err = rename(buffer, buffer1); 892 g_free(buffer); 893 g_free(buffer1); 894 if (err < 0 && errno != ENOENT) { 895 return err; 896 } 897 } 898 899 buffer = rpath(ctx, oldpath); 900 buffer1 = rpath(ctx, newpath); 901 err = rename(buffer, buffer1); 902 g_free(buffer); 903 g_free(buffer1); 904 return err; 905 } 906 907 static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp) 908 { 909 char *buffer; 910 int ret = -1; 911 char *path = fs_path->data; 912 913 if ((credp->fc_uid == -1 && credp->fc_gid == -1) || 914 (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || 915 (fs_ctx->export_flags & V9FS_SM_NONE)) { 916 buffer = rpath(fs_ctx, path); 917 ret = lchown(buffer, credp->fc_uid, credp->fc_gid); 918 g_free(buffer); 919 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED) { 920 buffer = rpath(fs_ctx, path); 921 ret = local_set_xattr(buffer, credp); 922 g_free(buffer); 923 } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { 924 return local_set_mapped_file_attr(fs_ctx, path, credp); 925 } 926 return ret; 927 } 928 929 static int local_utimensat(FsContext *s, V9fsPath *fs_path, 930 const struct timespec *buf) 931 { 932 char *buffer; 933 int ret; 934 char *path = fs_path->data; 935 936 buffer = rpath(s, path); 937 ret = qemu_utimens(buffer, buf); 938 g_free(buffer); 939 return ret; 940 } 941 942 static int local_remove(FsContext *ctx, const char *path) 943 { 944 int err; 945 struct stat stbuf; 946 char *buffer; 947 948 if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { 949 buffer = rpath(ctx, path); 950 err = lstat(buffer, &stbuf); 951 g_free(buffer); 952 if (err) { 953 goto err_out; 954 } 955 /* 956 * If directory remove .virtfs_metadata contained in the 957 * directory 958 */ 959 if (S_ISDIR(stbuf.st_mode)) { 960 buffer = g_strdup_printf("%s/%s/%s", ctx->fs_root, 961 path, VIRTFS_META_DIR); 962 err = remove(buffer); 963 g_free(buffer); 964 if (err < 0 && errno != ENOENT) { 965 /* 966 * We didn't had the .virtfs_metadata file. May be file created 967 * in non-mapped mode ?. Ignore ENOENT. 968 */ 969 goto err_out; 970 } 971 } 972 /* 973 * Now remove the name from parent directory 974 * .virtfs_metadata directory 975 */ 976 buffer = local_mapped_attr_path(ctx, path); 977 err = remove(buffer); 978 g_free(buffer); 979 if (err < 0 && errno != ENOENT) { 980 /* 981 * We didn't had the .virtfs_metadata file. May be file created 982 * in non-mapped mode ?. Ignore ENOENT. 983 */ 984 goto err_out; 985 } 986 } 987 988 buffer = rpath(ctx, path); 989 err = remove(buffer); 990 g_free(buffer); 991 err_out: 992 return err; 993 } 994 995 static int local_fsync(FsContext *ctx, int fid_type, 996 V9fsFidOpenState *fs, int datasync) 997 { 998 int fd; 999 1000 if (fid_type == P9_FID_DIR) { 1001 fd = dirfd(fs->dir); 1002 } else { 1003 fd = fs->fd; 1004 } 1005 1006 if (datasync) { 1007 return qemu_fdatasync(fd); 1008 } else { 1009 return fsync(fd); 1010 } 1011 } 1012 1013 static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf) 1014 { 1015 char *buffer; 1016 int ret; 1017 char *path = fs_path->data; 1018 1019 buffer = rpath(s, path); 1020 ret = statfs(buffer, stbuf); 1021 g_free(buffer); 1022 return ret; 1023 } 1024 1025 static ssize_t local_lgetxattr(FsContext *ctx, V9fsPath *fs_path, 1026 const char *name, void *value, size_t size) 1027 { 1028 char *path = fs_path->data; 1029 1030 return v9fs_get_xattr(ctx, path, name, value, size); 1031 } 1032 1033 static ssize_t local_llistxattr(FsContext *ctx, V9fsPath *fs_path, 1034 void *value, size_t size) 1035 { 1036 char *path = fs_path->data; 1037 1038 return v9fs_list_xattr(ctx, path, value, size); 1039 } 1040 1041 static int local_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name, 1042 void *value, size_t size, int flags) 1043 { 1044 char *path = fs_path->data; 1045 1046 return v9fs_set_xattr(ctx, path, name, value, size, flags); 1047 } 1048 1049 static int local_lremovexattr(FsContext *ctx, V9fsPath *fs_path, 1050 const char *name) 1051 { 1052 char *path = fs_path->data; 1053 1054 return v9fs_remove_xattr(ctx, path, name); 1055 } 1056 1057 static int local_name_to_path(FsContext *ctx, V9fsPath *dir_path, 1058 const char *name, V9fsPath *target) 1059 { 1060 if (dir_path) { 1061 v9fs_string_sprintf((V9fsString *)target, "%s/%s", 1062 dir_path->data, name); 1063 } else { 1064 v9fs_string_sprintf((V9fsString *)target, "%s", name); 1065 } 1066 /* Bump the size for including terminating NULL */ 1067 target->size++; 1068 return 0; 1069 } 1070 1071 static int local_renameat(FsContext *ctx, V9fsPath *olddir, 1072 const char *old_name, V9fsPath *newdir, 1073 const char *new_name) 1074 { 1075 int ret; 1076 V9fsString old_full_name, new_full_name; 1077 1078 v9fs_string_init(&old_full_name); 1079 v9fs_string_init(&new_full_name); 1080 1081 v9fs_string_sprintf(&old_full_name, "%s/%s", olddir->data, old_name); 1082 v9fs_string_sprintf(&new_full_name, "%s/%s", newdir->data, new_name); 1083 1084 ret = local_rename(ctx, old_full_name.data, new_full_name.data); 1085 v9fs_string_free(&old_full_name); 1086 v9fs_string_free(&new_full_name); 1087 return ret; 1088 } 1089 1090 static int local_unlinkat(FsContext *ctx, V9fsPath *dir, 1091 const char *name, int flags) 1092 { 1093 int ret; 1094 V9fsString fullname; 1095 char *buffer; 1096 1097 v9fs_string_init(&fullname); 1098 1099 v9fs_string_sprintf(&fullname, "%s/%s", dir->data, name); 1100 if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { 1101 if (flags == AT_REMOVEDIR) { 1102 /* 1103 * If directory remove .virtfs_metadata contained in the 1104 * directory 1105 */ 1106 buffer = g_strdup_printf("%s/%s/%s", ctx->fs_root, 1107 fullname.data, VIRTFS_META_DIR); 1108 ret = remove(buffer); 1109 g_free(buffer); 1110 if (ret < 0 && errno != ENOENT) { 1111 /* 1112 * We didn't had the .virtfs_metadata file. May be file created 1113 * in non-mapped mode ?. Ignore ENOENT. 1114 */ 1115 goto err_out; 1116 } 1117 } 1118 /* 1119 * Now remove the name from parent directory 1120 * .virtfs_metadata directory. 1121 */ 1122 buffer = local_mapped_attr_path(ctx, fullname.data); 1123 ret = remove(buffer); 1124 g_free(buffer); 1125 if (ret < 0 && errno != ENOENT) { 1126 /* 1127 * We didn't had the .virtfs_metadata file. May be file created 1128 * in non-mapped mode ?. Ignore ENOENT. 1129 */ 1130 goto err_out; 1131 } 1132 } 1133 /* Remove the name finally */ 1134 buffer = rpath(ctx, fullname.data); 1135 ret = remove(buffer); 1136 g_free(buffer); 1137 1138 err_out: 1139 v9fs_string_free(&fullname); 1140 return ret; 1141 } 1142 1143 static int local_ioc_getversion(FsContext *ctx, V9fsPath *path, 1144 mode_t st_mode, uint64_t *st_gen) 1145 { 1146 #ifdef FS_IOC_GETVERSION 1147 int err; 1148 V9fsFidOpenState fid_open; 1149 1150 /* 1151 * Do not try to open special files like device nodes, fifos etc 1152 * We can get fd for regular files and directories only 1153 */ 1154 if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) { 1155 errno = ENOTTY; 1156 return -1; 1157 } 1158 err = local_open(ctx, path, O_RDONLY, &fid_open); 1159 if (err < 0) { 1160 return err; 1161 } 1162 err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen); 1163 local_close(ctx, &fid_open); 1164 return err; 1165 #else 1166 errno = ENOTTY; 1167 return -1; 1168 #endif 1169 } 1170 1171 static int local_init(FsContext *ctx) 1172 { 1173 int err = 0; 1174 struct statfs stbuf; 1175 1176 if (ctx->export_flags & V9FS_SM_PASSTHROUGH) { 1177 ctx->xops = passthrough_xattr_ops; 1178 } else if (ctx->export_flags & V9FS_SM_MAPPED) { 1179 ctx->xops = mapped_xattr_ops; 1180 } else if (ctx->export_flags & V9FS_SM_NONE) { 1181 ctx->xops = none_xattr_ops; 1182 } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { 1183 /* 1184 * xattr operation for mapped-file and passthrough 1185 * remain same. 1186 */ 1187 ctx->xops = passthrough_xattr_ops; 1188 } 1189 ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT; 1190 #ifdef FS_IOC_GETVERSION 1191 /* 1192 * use ioc_getversion only if the iocl is definied 1193 */ 1194 err = statfs(ctx->fs_root, &stbuf); 1195 if (!err) { 1196 switch (stbuf.f_type) { 1197 case EXT2_SUPER_MAGIC: 1198 case BTRFS_SUPER_MAGIC: 1199 case REISERFS_SUPER_MAGIC: 1200 case XFS_SUPER_MAGIC: 1201 ctx->exops.get_st_gen = local_ioc_getversion; 1202 break; 1203 } 1204 } 1205 #endif 1206 return err; 1207 } 1208 1209 static int local_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse) 1210 { 1211 const char *sec_model = qemu_opt_get(opts, "security_model"); 1212 const char *path = qemu_opt_get(opts, "path"); 1213 1214 if (!sec_model) { 1215 error_report("Security model not specified, local fs needs security model"); 1216 error_printf("valid options are:" 1217 "\tsecurity_model=[passthrough|mapped-xattr|mapped-file|none]\n"); 1218 return -1; 1219 } 1220 1221 if (!strcmp(sec_model, "passthrough")) { 1222 fse->export_flags |= V9FS_SM_PASSTHROUGH; 1223 } else if (!strcmp(sec_model, "mapped") || 1224 !strcmp(sec_model, "mapped-xattr")) { 1225 fse->export_flags |= V9FS_SM_MAPPED; 1226 } else if (!strcmp(sec_model, "none")) { 1227 fse->export_flags |= V9FS_SM_NONE; 1228 } else if (!strcmp(sec_model, "mapped-file")) { 1229 fse->export_flags |= V9FS_SM_MAPPED_FILE; 1230 } else { 1231 error_report("Invalid security model %s specified", sec_model); 1232 error_printf("valid options are:" 1233 "\t[passthrough|mapped-xattr|mapped-file|none]\n"); 1234 return -1; 1235 } 1236 1237 if (!path) { 1238 error_report("fsdev: No path specified"); 1239 return -1; 1240 } 1241 fse->path = g_strdup(path); 1242 1243 return 0; 1244 } 1245 1246 FileOperations local_ops = { 1247 .parse_opts = local_parse_opts, 1248 .init = local_init, 1249 .lstat = local_lstat, 1250 .readlink = local_readlink, 1251 .close = local_close, 1252 .closedir = local_closedir, 1253 .open = local_open, 1254 .opendir = local_opendir, 1255 .rewinddir = local_rewinddir, 1256 .telldir = local_telldir, 1257 .readdir_r = local_readdir_r, 1258 .seekdir = local_seekdir, 1259 .preadv = local_preadv, 1260 .pwritev = local_pwritev, 1261 .chmod = local_chmod, 1262 .mknod = local_mknod, 1263 .mkdir = local_mkdir, 1264 .fstat = local_fstat, 1265 .open2 = local_open2, 1266 .symlink = local_symlink, 1267 .link = local_link, 1268 .truncate = local_truncate, 1269 .rename = local_rename, 1270 .chown = local_chown, 1271 .utimensat = local_utimensat, 1272 .remove = local_remove, 1273 .fsync = local_fsync, 1274 .statfs = local_statfs, 1275 .lgetxattr = local_lgetxattr, 1276 .llistxattr = local_llistxattr, 1277 .lsetxattr = local_lsetxattr, 1278 .lremovexattr = local_lremovexattr, 1279 .name_to_path = local_name_to_path, 1280 .renameat = local_renameat, 1281 .unlinkat = local_unlinkat, 1282 }; 1283