hw/9pfs/virtio-9p-local.c

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