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 "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 <libgen.h>
  25 #include <linux/fs.h>
  26 #ifdef CONFIG_LINUX_MAGIC_H
  27 #include <linux/magic.h>
  28 #endif
  29 #include <sys/ioctl.h>
  30
  31 #ifndef XFS_SUPER_MAGIC
  32 #define XFS_SUPER_MAGIC  0x58465342
  33 #endif
  34 #ifndef EXT2_SUPER_MAGIC
  35 #define EXT2_SUPER_MAGIC 0xEF53
  36 #endif
  37 #ifndef REISERFS_SUPER_MAGIC
  38 #define REISERFS_SUPER_MAGIC 0x52654973
  39 #endif
  40 #ifndef BTRFS_SUPER_MAGIC
  41 #define BTRFS_SUPER_MAGIC 0x9123683E
  42 #endif
  43
  44 #define VIRTFS_META_DIR ".virtfs_metadata"
  45
  46 static char *local_mapped_attr_path(FsContext *ctx, const char *path)
  47 {
  48     char *dir_name;
  49     char *tmp_path = g_strdup(path);
  50     char *base_name = basename(tmp_path);
  51     char *buffer;
  52
  53     /* NULL terminate the directory */
  54     dir_name = tmp_path;
  55     *(base_name - 1) = '\0';
  56
  57     buffer = g_strdup_printf("%s/%s/%s/%s",
  58              ctx->fs_root, dir_name, VIRTFS_META_DIR, base_name);
  59     g_free(tmp_path);
  60     return buffer;
  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     return 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     return 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;
 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             g_free(buffer);
 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             g_free(buffer);
 516             goto out;
 517         }
 518         err = local_set_mapped_file_attr(fs_ctx, path, credp);
 519         if (err == -1) {
 520             serrno = errno;
 521             goto err_end;
 522         }
 523     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 524                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 525         buffer = rpath(fs_ctx, path);
 526         err = mknod(buffer, credp->fc_mode, credp->fc_rdev);
 527         if (err == -1) {
 528             g_free(buffer);
 529             goto out;
 530         }
 531         err = local_post_create_passthrough(fs_ctx, path, credp);
 532         if (err == -1) {
 533             serrno = errno;
 534             goto err_end;
 535         }
 536     }
 537     goto out;
 538
 539 err_end:
 540     remove(buffer);
 541     errno = serrno;
 542     g_free(buffer);
 543 out:
 544     v9fs_string_free(&fullname);
 545     return err;
 546 }
 547
 548 static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
 549                        const char *name, FsCred *credp)
 550 {
 551     char *path;
 552     int err = -1;
 553     int serrno = 0;
 554     V9fsString fullname;
 555     char *buffer;
 556
 557     v9fs_string_init(&fullname);
 558     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 559     path = fullname.data;
 560
 561     /* Determine the security model */
 562     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 563         buffer = rpath(fs_ctx, path);
 564         err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS);
 565         if (err == -1) {
 566             g_free(buffer);
 567             goto out;
 568         }
 569         credp->fc_mode = credp->fc_mode|S_IFDIR;
 570         err = local_set_xattr(buffer, credp);
 571         if (err == -1) {
 572             serrno = errno;
 573             goto err_end;
 574         }
 575     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 576         buffer = rpath(fs_ctx, path);
 577         err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS);
 578         if (err == -1) {
 579             g_free(buffer);
 580             goto out;
 581         }
 582         credp->fc_mode = credp->fc_mode|S_IFDIR;
 583         err = local_set_mapped_file_attr(fs_ctx, path, credp);
 584         if (err == -1) {
 585             serrno = errno;
 586             goto err_end;
 587         }
 588     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 589                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 590         buffer = rpath(fs_ctx, path);
 591         err = mkdir(buffer, credp->fc_mode);
 592         if (err == -1) {
 593             g_free(buffer);
 594             goto out;
 595         }
 596         err = local_post_create_passthrough(fs_ctx, path, credp);
 597         if (err == -1) {
 598             serrno = errno;
 599             goto err_end;
 600         }
 601     }
 602     goto out;
 603
 604 err_end:
 605     remove(buffer);
 606     errno = serrno;
 607     g_free(buffer);
 608 out:
 609     v9fs_string_free(&fullname);
 610     return err;
 611 }
 612
 613 static int local_fstat(FsContext *fs_ctx, int fid_type,
 614                        V9fsFidOpenState *fs, struct stat *stbuf)
 615 {
 616     int err, fd;
 617
 618     if (fid_type == P9_FID_DIR) {
 619         fd = dirfd(fs->dir);
 620     } else {
 621         fd = fs->fd;
 622     }
 623
 624     err = fstat(fd, stbuf);
 625     if (err) {
 626         return err;
 627     }
 628     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 629         /* Actual credentials are part of extended attrs */
 630         uid_t tmp_uid;
 631         gid_t tmp_gid;
 632         mode_t tmp_mode;
 633         dev_t tmp_dev;
 634
 635         if (fgetxattr(fd, "user.virtfs.uid", &tmp_uid, sizeof(uid_t)) > 0) {
 636             stbuf->st_uid = le32_to_cpu(tmp_uid);
 637         }
 638         if (fgetxattr(fd, "user.virtfs.gid", &tmp_gid, sizeof(gid_t)) > 0) {
 639             stbuf->st_gid = le32_to_cpu(tmp_gid);
 640         }
 641         if (fgetxattr(fd, "user.virtfs.mode", &tmp_mode, sizeof(mode_t)) > 0) {
 642             stbuf->st_mode = le32_to_cpu(tmp_mode);
 643         }
 644         if (fgetxattr(fd, "user.virtfs.rdev", &tmp_dev, sizeof(dev_t)) > 0) {
 645             stbuf->st_rdev = le64_to_cpu(tmp_dev);
 646         }
 647     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 648         errno = EOPNOTSUPP;
 649         return -1;
 650     }
 651     return err;
 652 }
 653
 654 static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
 655                        int flags, FsCred *credp, V9fsFidOpenState *fs)
 656 {
 657     char *path;
 658     int fd = -1;
 659     int err = -1;
 660     int serrno = 0;
 661     V9fsString fullname;
 662     char *buffer;
 663
 664     /*
 665      * Mark all the open to not follow symlinks
 666      */
 667     flags |= O_NOFOLLOW;
 668
 669     v9fs_string_init(&fullname);
 670     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 671     path = fullname.data;
 672
 673     /* Determine the security model */
 674     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 675         buffer = rpath(fs_ctx, path);
 676         fd = open(buffer, flags, SM_LOCAL_MODE_BITS);
 677         if (fd == -1) {
 678             g_free(buffer);
 679             err = fd;
 680             goto out;
 681         }
 682         credp->fc_mode = credp->fc_mode|S_IFREG;
 683         /* Set cleint credentials in xattr */
 684         err = local_set_xattr(buffer, credp);
 685         if (err == -1) {
 686             serrno = errno;
 687             goto err_end;
 688         }
 689     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 690         buffer = rpath(fs_ctx, path);
 691         fd = open(buffer, flags, SM_LOCAL_MODE_BITS);
 692         if (fd == -1) {
 693             g_free(buffer);
 694             err = fd;
 695             goto out;
 696         }
 697         credp->fc_mode = credp->fc_mode|S_IFREG;
 698         /* Set client credentials in .virtfs_metadata directory files */
 699         err = local_set_mapped_file_attr(fs_ctx, path, credp);
 700         if (err == -1) {
 701             serrno = errno;
 702             goto err_end;
 703         }
 704     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 705                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 706         buffer = rpath(fs_ctx, path);
 707         fd = open(buffer, flags, credp->fc_mode);
 708         if (fd == -1) {
 709             g_free(buffer);
 710             err = fd;
 711             goto out;
 712         }
 713         err = local_post_create_passthrough(fs_ctx, path, credp);
 714         if (err == -1) {
 715             serrno = errno;
 716             goto err_end;
 717         }
 718     }
 719     err = fd;
 720     fs->fd = fd;
 721     goto out;
 722
 723 err_end:
 724     close(fd);
 725     remove(buffer);
 726     errno = serrno;
 727     g_free(buffer);
 728 out:
 729     v9fs_string_free(&fullname);
 730     return err;
 731 }
 732
 733
 734 static int local_symlink(FsContext *fs_ctx, const char *oldpath,
 735                          V9fsPath *dir_path, const char *name, FsCred *credp)
 736 {
 737     int err = -1;
 738     int serrno = 0;
 739     char *newpath;
 740     V9fsString fullname;
 741     char *buffer;
 742
 743     v9fs_string_init(&fullname);
 744     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 745     newpath = fullname.data;
 746
 747     /* Determine the security model */
 748     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 749         int fd;
 750         ssize_t oldpath_size, write_size;
 751         buffer = rpath(fs_ctx, newpath);
 752         fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS);
 753         if (fd == -1) {
 754             g_free(buffer);
 755             err = fd;
 756             goto out;
 757         }
 758         /* Write the oldpath (target) to the file. */
 759         oldpath_size = strlen(oldpath);
 760         do {
 761             write_size = write(fd, (void *)oldpath, oldpath_size);
 762         } while (write_size == -1 && errno == EINTR);
 763
 764         if (write_size != oldpath_size) {
 765             serrno = errno;
 766             close(fd);
 767             err = -1;
 768             goto err_end;
 769         }
 770         close(fd);
 771         /* Set cleint credentials in symlink's xattr */
 772         credp->fc_mode = credp->fc_mode|S_IFLNK;
 773         err = local_set_xattr(buffer, credp);
 774         if (err == -1) {
 775             serrno = errno;
 776             goto err_end;
 777         }
 778     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 779         int fd;
 780         ssize_t oldpath_size, write_size;
 781         buffer = rpath(fs_ctx, newpath);
 782         fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS);
 783         if (fd == -1) {
 784             g_free(buffer);
 785             err = fd;
 786             goto out;
 787         }
 788         /* Write the oldpath (target) to the file. */
 789         oldpath_size = strlen(oldpath);
 790         do {
 791             write_size = write(fd, (void *)oldpath, oldpath_size);
 792         } while (write_size == -1 && errno == EINTR);
 793
 794         if (write_size != oldpath_size) {
 795             serrno = errno;
 796             close(fd);
 797             err = -1;
 798             goto err_end;
 799         }
 800         close(fd);
 801         /* Set cleint credentials in symlink's xattr */
 802         credp->fc_mode = credp->fc_mode|S_IFLNK;
 803         err = local_set_mapped_file_attr(fs_ctx, newpath, credp);
 804         if (err == -1) {
 805             serrno = errno;
 806             goto err_end;
 807         }
 808     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 809                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 810         buffer = rpath(fs_ctx, newpath);
 811         err = symlink(oldpath, buffer);
 812         if (err) {
 813             g_free(buffer);
 814             goto out;
 815         }
 816         err = lchown(buffer, credp->fc_uid, credp->fc_gid);
 817         if (err == -1) {
 818             /*
 819              * If we fail to change ownership and if we are
 820              * using security model none. Ignore the error
 821              */
 822             if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
 823                 serrno = errno;
 824                 goto err_end;
 825             } else
 826                 err = 0;
 827         }
 828     }
 829     goto out;
 830
 831 err_end:
 832     remove(buffer);
 833     errno = serrno;
 834     g_free(buffer);
 835 out:
 836     v9fs_string_free(&fullname);
 837     return err;
 838 }
 839
 840 static int local_link(FsContext *ctx, V9fsPath *oldpath,
 841                       V9fsPath *dirpath, const char *name)
 842 {
 843     int ret;
 844     V9fsString newpath;
 845     char *buffer, *buffer1;
 846
 847     v9fs_string_init(&newpath);
 848     v9fs_string_sprintf(&newpath, "%s/%s", dirpath->data, name);
 849
 850     buffer = rpath(ctx, oldpath->data);
 851     buffer1 = rpath(ctx, newpath.data);
 852     ret = link(buffer, buffer1);
 853     g_free(buffer);
 854     g_free(buffer1);
 855
 856     /* now link the virtfs_metadata files */
 857     if (!ret && (ctx->export_flags & V9FS_SM_MAPPED_FILE)) {
 858         /* Link the .virtfs_metadata files. Create the metada directory */
 859         ret = local_create_mapped_attr_dir(ctx, newpath.data);
 860         if (ret < 0) {
 861             goto err_out;
 862         }
 863         buffer = local_mapped_attr_path(ctx, oldpath->data);
 864         buffer1 = local_mapped_attr_path(ctx, newpath.data);
 865         ret = link(buffer, buffer1);
 866         g_free(buffer);
 867         g_free(buffer1);
 868         if (ret < 0 && errno != ENOENT) {
 869             goto err_out;
 870         }
 871     }
 872 err_out:
 873     v9fs_string_free(&newpath);
 874     return ret;
 875 }
 876
 877 static int local_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
 878 {
 879     char *buffer;
 880     int ret;
 881     char *path = fs_path->data;
 882
 883     buffer = rpath(ctx, path);
 884     ret = truncate(buffer, size);
 885     g_free(buffer);
 886     return ret;
 887 }
 888
 889 static int local_rename(FsContext *ctx, const char *oldpath,
 890                         const char *newpath)
 891 {
 892     int err;
 893     char *buffer, *buffer1;
 894
 895     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 896         err = local_create_mapped_attr_dir(ctx, newpath);
 897         if (err < 0) {
 898             return err;
 899         }
 900         /* rename the .virtfs_metadata files */
 901         buffer = local_mapped_attr_path(ctx, oldpath);
 902         buffer1 = local_mapped_attr_path(ctx, newpath);
 903         err = rename(buffer, buffer1);
 904         g_free(buffer);
 905         g_free(buffer1);
 906         if (err < 0 && errno != ENOENT) {
 907             return err;
 908         }
 909     }
 910
 911     buffer = rpath(ctx, oldpath);
 912     buffer1 = rpath(ctx, newpath);
 913     err = rename(buffer, buffer1);
 914     g_free(buffer);
 915     g_free(buffer1);
 916     return err;
 917 }
 918
 919 static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 920 {
 921     char *buffer;
 922     int ret = -1;
 923     char *path = fs_path->data;
 924
 925     if ((credp->fc_uid == -1 && credp->fc_gid == -1) ||
 926         (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 927         (fs_ctx->export_flags & V9FS_SM_NONE)) {
 928         buffer = rpath(fs_ctx, path);
 929         ret = lchown(buffer, credp->fc_uid, credp->fc_gid);
 930         g_free(buffer);
 931     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 932         buffer = rpath(fs_ctx, path);
 933         ret = local_set_xattr(buffer, credp);
 934         g_free(buffer);
 935     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 936         return local_set_mapped_file_attr(fs_ctx, path, credp);
 937     }
 938     return ret;
 939 }
 940
 941 static int local_utimensat(FsContext *s, V9fsPath *fs_path,
 942                            const struct timespec *buf)
 943 {
 944     char *buffer;
 945     int ret;
 946     char *path = fs_path->data;
 947
 948     buffer = rpath(s, path);
 949     ret = qemu_utimens(buffer, buf);
 950     g_free(buffer);
 951     return ret;
 952 }
 953
 954 static int local_remove(FsContext *ctx, const char *path)
 955 {
 956     int err;
 957     struct stat stbuf;
 958     char *buffer;
 959
 960     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 961         buffer = rpath(ctx, path);
 962         err =  lstat(buffer, &stbuf);
 963         g_free(buffer);
 964         if (err) {
 965             goto err_out;
 966         }
 967         /*
 968          * If directory remove .virtfs_metadata contained in the
 969          * directory
 970          */
 971         if (S_ISDIR(stbuf.st_mode)) {
 972             buffer = g_strdup_printf("%s/%s/%s", ctx->fs_root,
 973                                      path, VIRTFS_META_DIR);
 974             err = remove(buffer);
 975             g_free(buffer);
 976             if (err < 0 && errno != ENOENT) {
 977                 /*
 978                  * We didn't had the .virtfs_metadata file. May be file created
 979                  * in non-mapped mode ?. Ignore ENOENT.
 980                  */
 981                 goto err_out;
 982             }
 983         }
 984         /*
 985          * Now remove the name from parent directory
 986          * .virtfs_metadata directory
 987          */
 988         buffer = local_mapped_attr_path(ctx, path);
 989         err = remove(buffer);
 990         g_free(buffer);
 991         if (err < 0 && errno != ENOENT) {
 992             /*
 993              * We didn't had the .virtfs_metadata file. May be file created
 994              * in non-mapped mode ?. Ignore ENOENT.
 995              */
 996             goto err_out;
 997         }
 998     }
 999
1000     buffer = rpath(ctx, path);
1001     err = remove(buffer);
1002     g_free(buffer);
1003 err_out:
1004     return err;
1005 }
1006
1007 static int local_fsync(FsContext *ctx, int fid_type,
1008                        V9fsFidOpenState *fs, int datasync)
1009 {
1010     int fd;
1011
1012     if (fid_type == P9_FID_DIR) {
1013         fd = dirfd(fs->dir);
1014     } else {
1015         fd = fs->fd;
1016     }
1017
1018     if (datasync) {
1019         return qemu_fdatasync(fd);
1020     } else {
1021         return fsync(fd);
1022     }
1023 }
1024
1025 static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
1026 {
1027     char *buffer;
1028     int ret;
1029     char *path = fs_path->data;
1030
1031     buffer = rpath(s, path);
1032     ret = statfs(buffer, stbuf);
1033     g_free(buffer);
1034     return ret;
1035 }
1036
1037 static ssize_t local_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
1038                                const char *name, void *value, size_t size)
1039 {
1040     char *path = fs_path->data;
1041
1042     return v9fs_get_xattr(ctx, path, name, value, size);
1043 }
1044
1045 static ssize_t local_llistxattr(FsContext *ctx, V9fsPath *fs_path,
1046                                 void *value, size_t size)
1047 {
1048     char *path = fs_path->data;
1049
1050     return v9fs_list_xattr(ctx, path, value, size);
1051 }
1052
1053 static int local_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name,
1054                            void *value, size_t size, int flags)
1055 {
1056     char *path = fs_path->data;
1057
1058     return v9fs_set_xattr(ctx, path, name, value, size, flags);
1059 }
1060
1061 static int local_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
1062                               const char *name)
1063 {
1064     char *path = fs_path->data;
1065
1066     return v9fs_remove_xattr(ctx, path, name);
1067 }
1068
1069 static int local_name_to_path(FsContext *ctx, V9fsPath *dir_path,
1070                               const char *name, V9fsPath *target)
1071 {
1072     if (dir_path) {
1073         v9fs_string_sprintf((V9fsString *)target, "%s/%s",
1074                             dir_path->data, name);
1075     } else {
1076         v9fs_string_sprintf((V9fsString *)target, "%s", name);
1077     }
1078     /* Bump the size for including terminating NULL */
1079     target->size++;
1080     return 0;
1081 }
1082
1083 static int local_renameat(FsContext *ctx, V9fsPath *olddir,
1084                           const char *old_name, V9fsPath *newdir,
1085                           const char *new_name)
1086 {
1087     int ret;
1088     V9fsString old_full_name, new_full_name;
1089
1090     v9fs_string_init(&old_full_name);
1091     v9fs_string_init(&new_full_name);
1092
1093     v9fs_string_sprintf(&old_full_name, "%s/%s", olddir->data, old_name);
1094     v9fs_string_sprintf(&new_full_name, "%s/%s", newdir->data, new_name);
1095
1096     ret = local_rename(ctx, old_full_name.data, new_full_name.data);
1097     v9fs_string_free(&old_full_name);
1098     v9fs_string_free(&new_full_name);
1099     return ret;
1100 }
1101
1102 static int local_unlinkat(FsContext *ctx, V9fsPath *dir,
1103                           const char *name, int flags)
1104 {
1105     int ret;
1106     V9fsString fullname;
1107     char *buffer;
1108
1109     v9fs_string_init(&fullname);
1110
1111     v9fs_string_sprintf(&fullname, "%s/%s", dir->data, name);
1112     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
1113         if (flags == AT_REMOVEDIR) {
1114             /*
1115              * If directory remove .virtfs_metadata contained in the
1116              * directory
1117              */
1118             buffer = g_strdup_printf("%s/%s/%s", ctx->fs_root,
1119                                      fullname.data, VIRTFS_META_DIR);
1120             ret = remove(buffer);
1121             g_free(buffer);
1122             if (ret < 0 && errno != ENOENT) {
1123                 /*
1124                  * We didn't had the .virtfs_metadata file. May be file created
1125                  * in non-mapped mode ?. Ignore ENOENT.
1126                  */
1127                 goto err_out;
1128             }
1129         }
1130         /*
1131          * Now remove the name from parent directory
1132          * .virtfs_metadata directory.
1133          */
1134         buffer = local_mapped_attr_path(ctx, fullname.data);
1135         ret = remove(buffer);
1136         g_free(buffer);
1137         if (ret < 0 && errno != ENOENT) {
1138             /*
1139              * We didn't had the .virtfs_metadata file. May be file created
1140              * in non-mapped mode ?. Ignore ENOENT.
1141              */
1142             goto err_out;
1143         }
1144     }
1145     /* Remove the name finally */
1146     buffer = rpath(ctx, fullname.data);
1147     ret = remove(buffer);
1148     g_free(buffer);
1149
1150 err_out:
1151     v9fs_string_free(&fullname);
1152     return ret;
1153 }
1154
1155 static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
1156                                 mode_t st_mode, uint64_t *st_gen)
1157 {
1158 #ifdef FS_IOC_GETVERSION
1159     int err;
1160     V9fsFidOpenState fid_open;
1161
1162     /*
1163      * Do not try to open special files like device nodes, fifos etc
1164      * We can get fd for regular files and directories only
1165      */
1166     if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
1167         errno = ENOTTY;
1168         return -1;
1169     }
1170     err = local_open(ctx, path, O_RDONLY, &fid_open);
1171     if (err < 0) {
1172         return err;
1173     }
1174     err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
1175     local_close(ctx, &fid_open);
1176     return err;
1177 #else
1178     errno = ENOTTY;
1179     return -1;
1180 #endif
1181 }
1182
1183 static int local_init(FsContext *ctx)
1184 {
1185     int err = 0;
1186     struct statfs stbuf;
1187
1188     if (ctx->export_flags & V9FS_SM_PASSTHROUGH) {
1189         ctx->xops = passthrough_xattr_ops;
1190     } else if (ctx->export_flags & V9FS_SM_MAPPED) {
1191         ctx->xops = mapped_xattr_ops;
1192     } else if (ctx->export_flags & V9FS_SM_NONE) {
1193         ctx->xops = none_xattr_ops;
1194     } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
1195         /*
1196          * xattr operation for mapped-file and passthrough
1197          * remain same.
1198          */
1199         ctx->xops = passthrough_xattr_ops;
1200     }
1201     ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT;
1202 #ifdef FS_IOC_GETVERSION
1203     /*
1204      * use ioc_getversion only if the iocl is definied
1205      */
1206     err = statfs(ctx->fs_root, &stbuf);
1207     if (!err) {
1208         switch (stbuf.f_type) {
1209         case EXT2_SUPER_MAGIC:
1210         case BTRFS_SUPER_MAGIC:
1211         case REISERFS_SUPER_MAGIC:
1212         case XFS_SUPER_MAGIC:
1213             ctx->exops.get_st_gen = local_ioc_getversion;
1214             break;
1215         }
1216     }
1217 #endif
1218     return err;
1219 }
1220
1221 static int local_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse)
1222 {
1223     const char *sec_model = qemu_opt_get(opts, "security_model");
1224     const char *path = qemu_opt_get(opts, "path");
1225
1226     if (!sec_model) {
1227         fprintf(stderr, "security model not specified, "
1228                 "local fs needs security model\nvalid options are:"
1229                 "\tsecurity_model=[passthrough|mapped|none]\n");
1230         return -1;
1231     }
1232
1233     if (!strcmp(sec_model, "passthrough")) {
1234         fse->export_flags |= V9FS_SM_PASSTHROUGH;
1235     } else if (!strcmp(sec_model, "mapped") ||
1236                !strcmp(sec_model, "mapped-xattr")) {
1237         fse->export_flags |= V9FS_SM_MAPPED;
1238     } else if (!strcmp(sec_model, "none")) {
1239         fse->export_flags |= V9FS_SM_NONE;
1240     } else if (!strcmp(sec_model, "mapped-file")) {
1241         fse->export_flags |= V9FS_SM_MAPPED_FILE;
1242     } else {
1243         fprintf(stderr, "Invalid security model %s specified, valid options are"
1244                 "\n\t [passthrough|mapped-xattr|mapped-file|none]\n",
1245                 sec_model);
1246         return -1;
1247     }
1248
1249     if (!path) {
1250         fprintf(stderr, "fsdev: No path specified.\n");
1251         return -1;
1252     }
1253     fse->path = g_strdup(path);
1254
1255     return 0;
1256 }
1257
1258 FileOperations local_ops = {
1259     .parse_opts = local_parse_opts,
1260     .init  = local_init,
1261     .lstat = local_lstat,
1262     .readlink = local_readlink,
1263     .close = local_close,
1264     .closedir = local_closedir,
1265     .open = local_open,
1266     .opendir = local_opendir,
1267     .rewinddir = local_rewinddir,
1268     .telldir = local_telldir,
1269     .readdir_r = local_readdir_r,
1270     .seekdir = local_seekdir,
1271     .preadv = local_preadv,
1272     .pwritev = local_pwritev,
1273     .chmod = local_chmod,
1274     .mknod = local_mknod,
1275     .mkdir = local_mkdir,
1276     .fstat = local_fstat,
1277     .open2 = local_open2,
1278     .symlink = local_symlink,
1279     .link = local_link,
1280     .truncate = local_truncate,
1281     .rename = local_rename,
1282     .chown = local_chown,
1283     .utimensat = local_utimensat,
1284     .remove = local_remove,
1285     .fsync = local_fsync,
1286     .statfs = local_statfs,
1287     .lgetxattr = local_lgetxattr,
1288     .llistxattr = local_llistxattr,
1289     .lsetxattr = local_lsetxattr,
1290     .lremovexattr = local_lremovexattr,
1291     .name_to_path = local_name_to_path,
1292     .renameat  = local_renameat,
1293     .unlinkat = local_unlinkat,
1294 };