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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
#define ATTR_MAX 100
63
static void local_mapped_file_attr(FsContext *ctx, const char *path,
64
                                   struct stat *stbuf)
65
{
66
    FILE *fp;
67
    char buf[ATTR_MAX];
68
    char attr_path[PATH_MAX];
69

    
70
    local_mapped_attr_path(ctx, path, attr_path);
71
    fp = fopen(attr_path, "r");
72
    if (!fp) {
73
        return;
74
    }
75
    memset(buf, 0, ATTR_MAX);
76
    while (fgets(buf, ATTR_MAX, fp)) {
77
        if (!strncmp(buf, "virtfs.uid", 10)) {
78
            stbuf->st_uid = atoi(buf+11);
79
        } else if (!strncmp(buf, "virtfs.gid", 10)) {
80
            stbuf->st_gid = atoi(buf+11);
81
        } else if (!strncmp(buf, "virtfs.mode", 11)) {
82
            stbuf->st_mode = atoi(buf+12);
83
        } else if (!strncmp(buf, "virtfs.rdev", 11)) {
84
            stbuf->st_rdev = atoi(buf+12);
85
        }
86
        memset(buf, 0, ATTR_MAX);
87
    }
88
    fclose(fp);
89
}
90

    
91
static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
92
{
93
    int err;
94
    char buffer[PATH_MAX];
95
    char *path = fs_path->data;
96

    
97
    err =  lstat(rpath(fs_ctx, path, buffer), stbuf);
98
    if (err) {
99
        return err;
100
    }
101
    if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
102
        /* Actual credentials are part of extended attrs */
103
        uid_t tmp_uid;
104
        gid_t tmp_gid;
105
        mode_t tmp_mode;
106
        dev_t tmp_dev;
107
        if (getxattr(rpath(fs_ctx, path, buffer), "user.virtfs.uid", &tmp_uid,
108
                    sizeof(uid_t)) > 0) {
109
            stbuf->st_uid = tmp_uid;
110
        }
111
        if (getxattr(rpath(fs_ctx, path, buffer), "user.virtfs.gid", &tmp_gid,
112
                    sizeof(gid_t)) > 0) {
113
            stbuf->st_gid = tmp_gid;
114
        }
115
        if (getxattr(rpath(fs_ctx, path, buffer), "user.virtfs.mode",
116
                    &tmp_mode, sizeof(mode_t)) > 0) {
117
            stbuf->st_mode = tmp_mode;
118
        }
119
        if (getxattr(rpath(fs_ctx, path, buffer), "user.virtfs.rdev", &tmp_dev,
120
                        sizeof(dev_t)) > 0) {
121
                stbuf->st_rdev = tmp_dev;
122
        }
123
    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
124
        local_mapped_file_attr(fs_ctx, path, stbuf);
125
    }
126
    return err;
127
}
128

    
129
static int local_create_mapped_attr_dir(FsContext *ctx, const char *path)
130
{
131
    int err;
132
    char attr_dir[PATH_MAX];
133
    char *tmp_path = g_strdup(path);
134

    
135
    snprintf(attr_dir, PATH_MAX, "%s/%s/%s",
136
             ctx->fs_root, dirname(tmp_path), VIRTFS_META_DIR);
137

    
138
    err = mkdir(attr_dir, 0700);
139
    if (err < 0 && errno == EEXIST) {
140
        err = 0;
141
    }
142
    g_free(tmp_path);
143
    return err;
144
}
145

    
146
static int local_set_mapped_file_attr(FsContext *ctx,
147
                                      const char *path, FsCred *credp)
148
{
149
    FILE *fp;
150
    int ret = 0;
151
    char buf[ATTR_MAX];
152
    char attr_path[PATH_MAX];
153
    int uid = -1, gid = -1, mode = -1, rdev = -1;
154

    
155
    fp = fopen(local_mapped_attr_path(ctx, path, attr_path), "r");
156
    if (!fp) {
157
        goto create_map_file;
158
    }
159
    memset(buf, 0, ATTR_MAX);
160
    while (fgets(buf, ATTR_MAX, fp)) {
161
        if (!strncmp(buf, "virtfs.uid", 10)) {
162
            uid = atoi(buf+11);
163
        } else if (!strncmp(buf, "virtfs.gid", 10)) {
164
            gid = atoi(buf+11);
165
        } else if (!strncmp(buf, "virtfs.mode", 11)) {
166
            mode = atoi(buf+12);
167
        } else if (!strncmp(buf, "virtfs.rdev", 11)) {
168
            rdev = atoi(buf+12);
169
        }
170
        memset(buf, 0, ATTR_MAX);
171
    }
172
    fclose(fp);
173
    goto update_map_file;
174

    
175
create_map_file:
176
    ret = local_create_mapped_attr_dir(ctx, path);
177
    if (ret < 0) {
178
        goto err_out;
179
    }
180

    
181
update_map_file:
182
    fp = fopen(attr_path, "w");
183
    if (!fp) {
184
        ret = -1;
185
        goto err_out;
186
    }
187

    
188
    if (credp->fc_uid != -1) {
189
        uid = credp->fc_uid;
190
    }
191
    if (credp->fc_gid != -1) {
192
        gid = credp->fc_gid;
193
    }
194
    if (credp->fc_mode != -1) {
195
        mode = credp->fc_mode;
196
    }
197
    if (credp->fc_rdev != -1) {
198
        rdev = credp->fc_rdev;
199
    }
200

    
201

    
202
    if (uid != -1) {
203
        fprintf(fp, "virtfs.uid=%d\n", uid);
204
    }
205
    if (gid != -1) {
206
        fprintf(fp, "virtfs.gid=%d\n", gid);
207
    }
208
    if (mode != -1) {
209
        fprintf(fp, "virtfs.mode=%d\n", mode);
210
    }
211
    if (rdev != -1) {
212
        fprintf(fp, "virtfs.rdev=%d\n", rdev);
213
    }
214
    fclose(fp);
215

    
216
err_out:
217
    return ret;
218
}
219

    
220
static int local_set_xattr(const char *path, FsCred *credp)
221
{
222
    int err;
223

    
224
    if (credp->fc_uid != -1) {
225
        err = setxattr(path, "user.virtfs.uid", &credp->fc_uid, sizeof(uid_t),
226
                0);
227
        if (err) {
228
            return err;
229
        }
230
    }
231
    if (credp->fc_gid != -1) {
232
        err = setxattr(path, "user.virtfs.gid", &credp->fc_gid, sizeof(gid_t),
233
                0);
234
        if (err) {
235
            return err;
236
        }
237
    }
238
    if (credp->fc_mode != -1) {
239
        err = setxattr(path, "user.virtfs.mode", &credp->fc_mode,
240
                sizeof(mode_t), 0);
241
        if (err) {
242
            return err;
243
        }
244
    }
245
    if (credp->fc_rdev != -1) {
246
        err = setxattr(path, "user.virtfs.rdev", &credp->fc_rdev,
247
                sizeof(dev_t), 0);
248
        if (err) {
249
            return err;
250
        }
251
    }
252
    return 0;
253
}
254

    
255
static int local_post_create_passthrough(FsContext *fs_ctx, const char *path,
256
                                         FsCred *credp)
257
{
258
    char buffer[PATH_MAX];
259

    
260
    if (lchown(rpath(fs_ctx, path, buffer), credp->fc_uid,
261
                credp->fc_gid) < 0) {
262
        /*
263
         * If we fail to change ownership and if we are
264
         * using security model none. Ignore the error
265
         */
266
        if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
267
            return -1;
268
        }
269
    }
270

    
271
    if (chmod(rpath(fs_ctx, path, buffer), credp->fc_mode & 07777) < 0) {
272
        return -1;
273
    }
274
    return 0;
275
}
276

    
277
static ssize_t local_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
278
                              char *buf, size_t bufsz)
279
{
280
    ssize_t tsize = -1;
281
    char buffer[PATH_MAX];
282
    char *path = fs_path->data;
283

    
284
    if ((fs_ctx->export_flags & V9FS_SM_MAPPED) ||
285
        (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE)) {
286
        int fd;
287
        fd = open(rpath(fs_ctx, path, buffer), O_RDONLY);
288
        if (fd == -1) {
289
            return -1;
290
        }
291
        do {
292
            tsize = read(fd, (void *)buf, bufsz);
293
        } while (tsize == -1 && errno == EINTR);
294
        close(fd);
295
        return tsize;
296
    } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
297
               (fs_ctx->export_flags & V9FS_SM_NONE)) {
298
        tsize = readlink(rpath(fs_ctx, path, buffer), buf, bufsz);
299
    }
300
    return tsize;
301
}
302

    
303
static int local_close(FsContext *ctx, V9fsFidOpenState *fs)
304
{
305
    return close(fs->fd);
306
}
307

    
308
static int local_closedir(FsContext *ctx, V9fsFidOpenState *fs)
309
{
310
    return closedir(fs->dir);
311
}
312

    
313
static int local_open(FsContext *ctx, V9fsPath *fs_path,
314
                      int flags, V9fsFidOpenState *fs)
315
{
316
    char buffer[PATH_MAX];
317
    char *path = fs_path->data;
318

    
319
    fs->fd = open(rpath(ctx, path, buffer), flags);
320
    return fs->fd;
321
}
322

    
323
static int local_opendir(FsContext *ctx,
324
                         V9fsPath *fs_path, V9fsFidOpenState *fs)
325
{
326
    char buffer[PATH_MAX];
327
    char *path = fs_path->data;
328

    
329
    fs->dir = opendir(rpath(ctx, path, buffer));
330
    if (!fs->dir) {
331
        return -1;
332
    }
333
    return 0;
334
}
335

    
336
static void local_rewinddir(FsContext *ctx, V9fsFidOpenState *fs)
337
{
338
    return rewinddir(fs->dir);
339
}
340

    
341
static off_t local_telldir(FsContext *ctx, V9fsFidOpenState *fs)
342
{
343
    return telldir(fs->dir);
344
}
345

    
346
static int local_readdir_r(FsContext *ctx, V9fsFidOpenState *fs,
347
                           struct dirent *entry,
348
                           struct dirent **result)
349
{
350
    int ret;
351

    
352
again:
353
    ret = readdir_r(fs->dir, entry, result);
354
    if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
355
        if (!ret && *result != NULL &&
356
            !strcmp(entry->d_name, VIRTFS_META_DIR)) {
357
            /* skp the meta data directory */
358
            goto again;
359
        }
360
    }
361
    return ret;
362
}
363

    
364
static void local_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off)
365
{
366
    return seekdir(fs->dir, off);
367
}
368

    
369
static ssize_t local_preadv(FsContext *ctx, V9fsFidOpenState *fs,
370
                            const struct iovec *iov,
371
                            int iovcnt, off_t offset)
372
{
373
#ifdef CONFIG_PREADV
374
    return preadv(fs->fd, iov, iovcnt, offset);
375
#else
376
    int err = lseek(fs->fd, offset, SEEK_SET);
377
    if (err == -1) {
378
        return err;
379
    } else {
380
        return readv(fs->fd, iov, iovcnt);
381
    }
382
#endif
383
}
384

    
385
static ssize_t local_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
386
                             const struct iovec *iov,
387
                             int iovcnt, off_t offset)
388
{
389
    ssize_t ret
390
;
391
#ifdef CONFIG_PREADV
392
    ret = pwritev(fs->fd, iov, iovcnt, offset);
393
#else
394
    int err = lseek(fs->fd, offset, SEEK_SET);
395
    if (err == -1) {
396
        return err;
397
    } else {
398
        ret = writev(fs->fd, iov, iovcnt);
399
    }
400
#endif
401
#ifdef CONFIG_SYNC_FILE_RANGE
402
    if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) {
403
        /*
404
         * Initiate a writeback. This is not a data integrity sync.
405
         * We want to ensure that we don't leave dirty pages in the cache
406
         * after write when writeout=immediate is sepcified.
407
         */
408
        sync_file_range(fs->fd, offset, ret,
409
                        SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE);
410
    }
411
#endif
412
    return ret;
413
}
414

    
415
static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
416
{
417
    char buffer[PATH_MAX];
418
    char *path = fs_path->data;
419

    
420
    if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
421
        return local_set_xattr(rpath(fs_ctx, path, buffer), credp);
422
    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
423
        return local_set_mapped_file_attr(fs_ctx, path, credp);
424
    } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
425
               (fs_ctx->export_flags & V9FS_SM_NONE)) {
426
        return chmod(rpath(fs_ctx, path, buffer), credp->fc_mode);
427
    }
428
    return -1;
429
}
430

    
431
static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
432
                       const char *name, FsCred *credp)
433
{
434
    char *path;
435
    int err = -1;
436
    int serrno = 0;
437
    V9fsString fullname;
438
    char buffer[PATH_MAX];
439

    
440
    v9fs_string_init(&fullname);
441
    v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
442
    path = fullname.data;
443

    
444
    /* Determine the security model */
445
    if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
446
        err = mknod(rpath(fs_ctx, path, buffer),
447
                SM_LOCAL_MODE_BITS|S_IFREG, 0);
448
        if (err == -1) {
449
            goto out;
450
        }
451
        err = local_set_xattr(rpath(fs_ctx, path, buffer), credp);
452
        if (err == -1) {
453
            serrno = errno;
454
            goto err_end;
455
        }
456
    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
457

    
458
        err = mknod(rpath(fs_ctx, path, buffer),
459
                    SM_LOCAL_MODE_BITS|S_IFREG, 0);
460
        if (err == -1) {
461
            goto out;
462
        }
463
        err = local_set_mapped_file_attr(fs_ctx, path, credp);
464
        if (err == -1) {
465
            serrno = errno;
466
            goto err_end;
467
        }
468
    } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
469
               (fs_ctx->export_flags & V9FS_SM_NONE)) {
470
        err = mknod(rpath(fs_ctx, path, buffer), credp->fc_mode,
471
                credp->fc_rdev);
472
        if (err == -1) {
473
            goto out;
474
        }
475
        err = local_post_create_passthrough(fs_ctx, path, credp);
476
        if (err == -1) {
477
            serrno = errno;
478
            goto err_end;
479
        }
480
    }
481
    goto out;
482

    
483
err_end:
484
    remove(rpath(fs_ctx, path, buffer));
485
    errno = serrno;
486
out:
487
    v9fs_string_free(&fullname);
488
    return err;
489
}
490

    
491
static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
492
                       const char *name, FsCred *credp)
493
{
494
    char *path;
495
    int err = -1;
496
    int serrno = 0;
497
    V9fsString fullname;
498
    char buffer[PATH_MAX];
499

    
500
    v9fs_string_init(&fullname);
501
    v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
502
    path = fullname.data;
503

    
504
    /* Determine the security model */
505
    if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
506
        err = mkdir(rpath(fs_ctx, path, buffer), SM_LOCAL_DIR_MODE_BITS);
507
        if (err == -1) {
508
            goto out;
509
        }
510
        credp->fc_mode = credp->fc_mode|S_IFDIR;
511
        err = local_set_xattr(rpath(fs_ctx, path, buffer), credp);
512
        if (err == -1) {
513
            serrno = errno;
514
            goto err_end;
515
        }
516
    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
517
        err = mkdir(rpath(fs_ctx, path, buffer), SM_LOCAL_DIR_MODE_BITS);
518
        if (err == -1) {
519
            goto out;
520
        }
521
        credp->fc_mode = credp->fc_mode|S_IFDIR;
522
        err = local_set_mapped_file_attr(fs_ctx, path, credp);
523
        if (err == -1) {
524
            serrno = errno;
525
            goto err_end;
526
        }
527
    } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
528
               (fs_ctx->export_flags & V9FS_SM_NONE)) {
529
        err = mkdir(rpath(fs_ctx, path, buffer), credp->fc_mode);
530
        if (err == -1) {
531
            goto out;
532
        }
533
        err = local_post_create_passthrough(fs_ctx, path, credp);
534
        if (err == -1) {
535
            serrno = errno;
536
            goto err_end;
537
        }
538
    }
539
    goto out;
540

    
541
err_end:
542
    remove(rpath(fs_ctx, path, buffer));
543
    errno = serrno;
544
out:
545
    v9fs_string_free(&fullname);
546
    return err;
547
}
548

    
549
static int local_fstat(FsContext *fs_ctx, int fid_type,
550
                       V9fsFidOpenState *fs, struct stat *stbuf)
551
{
552
    int err, fd;
553

    
554
    if (fid_type == P9_FID_DIR) {
555
        fd = dirfd(fs->dir);
556
    } else {
557
        fd = fs->fd;
558
    }
559

    
560
    err = fstat(fd, stbuf);
561
    if (err) {
562
        return err;
563
    }
564
    if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
565
        /* Actual credentials are part of extended attrs */
566
        uid_t tmp_uid;
567
        gid_t tmp_gid;
568
        mode_t tmp_mode;
569
        dev_t tmp_dev;
570

    
571
        if (fgetxattr(fd, "user.virtfs.uid",
572
                      &tmp_uid, sizeof(uid_t)) > 0) {
573
            stbuf->st_uid = tmp_uid;
574
        }
575
        if (fgetxattr(fd, "user.virtfs.gid",
576
                      &tmp_gid, sizeof(gid_t)) > 0) {
577
            stbuf->st_gid = tmp_gid;
578
        }
579
        if (fgetxattr(fd, "user.virtfs.mode",
580
                      &tmp_mode, sizeof(mode_t)) > 0) {
581
            stbuf->st_mode = tmp_mode;
582
        }
583
        if (fgetxattr(fd, "user.virtfs.rdev",
584
                      &tmp_dev, sizeof(dev_t)) > 0) {
585
                stbuf->st_rdev = tmp_dev;
586
        }
587
    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
588
        errno = EOPNOTSUPP;
589
        return -1;
590
    }
591
    return err;
592
}
593

    
594
static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
595
                       int flags, FsCred *credp, V9fsFidOpenState *fs)
596
{
597
    char *path;
598
    int fd = -1;
599
    int err = -1;
600
    int serrno = 0;
601
    V9fsString fullname;
602
    char buffer[PATH_MAX];
603

    
604
    v9fs_string_init(&fullname);
605
    v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
606
    path = fullname.data;
607

    
608
    /* Determine the security model */
609
    if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
610
        fd = open(rpath(fs_ctx, path, buffer), flags, SM_LOCAL_MODE_BITS);
611
        if (fd == -1) {
612
            err = fd;
613
            goto out;
614
        }
615
        credp->fc_mode = credp->fc_mode|S_IFREG;
616
        /* Set cleint credentials in xattr */
617
        err = local_set_xattr(rpath(fs_ctx, path, buffer), credp);
618
        if (err == -1) {
619
            serrno = errno;
620
            goto err_end;
621
        }
622
    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
623
        fd = open(rpath(fs_ctx, path, buffer), flags, SM_LOCAL_MODE_BITS);
624
        if (fd == -1) {
625
            err = fd;
626
            goto out;
627
        }
628
        credp->fc_mode = credp->fc_mode|S_IFREG;
629
        /* Set client credentials in .virtfs_metadata directory files */
630
        err = local_set_mapped_file_attr(fs_ctx, path, credp);
631
        if (err == -1) {
632
            serrno = errno;
633
            goto err_end;
634
        }
635
    } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
636
               (fs_ctx->export_flags & V9FS_SM_NONE)) {
637
        fd = open(rpath(fs_ctx, path, buffer), flags, credp->fc_mode);
638
        if (fd == -1) {
639
            err = fd;
640
            goto out;
641
        }
642
        err = local_post_create_passthrough(fs_ctx, path, credp);
643
        if (err == -1) {
644
            serrno = errno;
645
            goto err_end;
646
        }
647
    }
648
    err = fd;
649
    fs->fd = fd;
650
    goto out;
651

    
652
err_end:
653
    close(fd);
654
    remove(rpath(fs_ctx, path, buffer));
655
    errno = serrno;
656
out:
657
    v9fs_string_free(&fullname);
658
    return err;
659
}
660

    
661

    
662
static int local_symlink(FsContext *fs_ctx, const char *oldpath,
663
                         V9fsPath *dir_path, const char *name, FsCred *credp)
664
{
665
    int err = -1;
666
    int serrno = 0;
667
    char *newpath;
668
    V9fsString fullname;
669
    char buffer[PATH_MAX];
670

    
671
    v9fs_string_init(&fullname);
672
    v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
673
    newpath = fullname.data;
674

    
675
    /* Determine the security model */
676
    if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
677
        int fd;
678
        ssize_t oldpath_size, write_size;
679
        fd = open(rpath(fs_ctx, newpath, buffer), O_CREAT|O_EXCL|O_RDWR,
680
                SM_LOCAL_MODE_BITS);
681
        if (fd == -1) {
682
            err = fd;
683
            goto out;
684
        }
685
        /* Write the oldpath (target) to the file. */
686
        oldpath_size = strlen(oldpath);
687
        do {
688
            write_size = write(fd, (void *)oldpath, oldpath_size);
689
        } while (write_size == -1 && errno == EINTR);
690

    
691
        if (write_size != oldpath_size) {
692
            serrno = errno;
693
            close(fd);
694
            err = -1;
695
            goto err_end;
696
        }
697
        close(fd);
698
        /* Set cleint credentials in symlink's xattr */
699
        credp->fc_mode = credp->fc_mode|S_IFLNK;
700
        err = local_set_xattr(rpath(fs_ctx, newpath, buffer), credp);
701
        if (err == -1) {
702
            serrno = errno;
703
            goto err_end;
704
        }
705
    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
706
        int fd;
707
        ssize_t oldpath_size, write_size;
708
        fd = open(rpath(fs_ctx, newpath, buffer), O_CREAT|O_EXCL|O_RDWR,
709
                  SM_LOCAL_MODE_BITS);
710
        if (fd == -1) {
711
            err = fd;
712
            goto out;
713
        }
714
        /* Write the oldpath (target) to the file. */
715
        oldpath_size = strlen(oldpath);
716
        do {
717
            write_size = write(fd, (void *)oldpath, oldpath_size);
718
        } while (write_size == -1 && errno == EINTR);
719

    
720
        if (write_size != oldpath_size) {
721
            serrno = errno;
722
            close(fd);
723
            err = -1;
724
            goto err_end;
725
        }
726
        close(fd);
727
        /* Set cleint credentials in symlink's xattr */
728
        credp->fc_mode = credp->fc_mode|S_IFLNK;
729
        err = local_set_mapped_file_attr(fs_ctx, newpath, credp);
730
        if (err == -1) {
731
            serrno = errno;
732
            goto err_end;
733
        }
734
    } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
735
               (fs_ctx->export_flags & V9FS_SM_NONE)) {
736
        err = symlink(oldpath, rpath(fs_ctx, newpath, buffer));
737
        if (err) {
738
            goto out;
739
        }
740
        err = lchown(rpath(fs_ctx, newpath, buffer), credp->fc_uid,
741
                     credp->fc_gid);
742
        if (err == -1) {
743
            /*
744
             * If we fail to change ownership and if we are
745
             * using security model none. Ignore the error
746
             */
747
            if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
748
                serrno = errno;
749
                goto err_end;
750
            } else
751
                err = 0;
752
        }
753
    }
754
    goto out;
755

    
756
err_end:
757
    remove(rpath(fs_ctx, newpath, buffer));
758
    errno = serrno;
759
out:
760
    v9fs_string_free(&fullname);
761
    return err;
762
}
763

    
764
static int local_link(FsContext *ctx, V9fsPath *oldpath,
765
                      V9fsPath *dirpath, const char *name)
766
{
767
    int ret;
768
    V9fsString newpath;
769
    char buffer[PATH_MAX], buffer1[PATH_MAX];
770

    
771
    v9fs_string_init(&newpath);
772
    v9fs_string_sprintf(&newpath, "%s/%s", dirpath->data, name);
773

    
774
    ret = link(rpath(ctx, oldpath->data, buffer),
775
               rpath(ctx, newpath.data, buffer1));
776

    
777
    /* now link the virtfs_metadata files */
778
    if (!ret && (ctx->export_flags & V9FS_SM_MAPPED_FILE)) {
779
        /* Link the .virtfs_metadata files. Create the metada directory */
780
        ret = local_create_mapped_attr_dir(ctx, newpath.data);
781
        if (ret < 0) {
782
            goto err_out;
783
        }
784
        ret = link(local_mapped_attr_path(ctx, oldpath->data, buffer),
785
                   local_mapped_attr_path(ctx, newpath.data, buffer1));
786
        if (ret < 0 && errno != ENOENT) {
787
            goto err_out;
788
        }
789
    }
790
err_out:
791
    v9fs_string_free(&newpath);
792
    return ret;
793
}
794

    
795
static int local_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
796
{
797
    char buffer[PATH_MAX];
798
    char *path = fs_path->data;
799

    
800
    return truncate(rpath(ctx, path, buffer), size);
801
}
802

    
803
static int local_rename(FsContext *ctx, const char *oldpath,
804
                        const char *newpath)
805
{
806
    int err;
807
    char buffer[PATH_MAX], buffer1[PATH_MAX];
808

    
809
    if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
810
        err = local_create_mapped_attr_dir(ctx, newpath);
811
        if (err < 0) {
812
            return err;
813
        }
814
        /* rename the .virtfs_metadata files */
815
        err = rename(local_mapped_attr_path(ctx, oldpath, buffer),
816
                     local_mapped_attr_path(ctx, newpath, buffer1));
817
        if (err < 0 && errno != ENOENT) {
818
            return err;
819
        }
820
    }
821
    return rename(rpath(ctx, oldpath, buffer), rpath(ctx, newpath, buffer1));
822
}
823

    
824
static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
825
{
826
    char buffer[PATH_MAX];
827
    char *path = fs_path->data;
828

    
829
    if ((credp->fc_uid == -1 && credp->fc_gid == -1) ||
830
        (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
831
        (fs_ctx->export_flags & V9FS_SM_NONE)) {
832
        return lchown(rpath(fs_ctx, path, buffer),
833
                      credp->fc_uid, credp->fc_gid);
834
    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
835
        return local_set_xattr(rpath(fs_ctx, path, buffer), credp);
836
    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
837
        return local_set_mapped_file_attr(fs_ctx, path, credp);
838
    }
839
    return -1;
840
}
841

    
842
static int local_utimensat(FsContext *s, V9fsPath *fs_path,
843
                           const struct timespec *buf)
844
{
845
    char buffer[PATH_MAX];
846
    char *path = fs_path->data;
847

    
848
    return qemu_utimens(rpath(s, path, buffer), buf);
849
}
850

    
851
static int local_remove(FsContext *ctx, const char *path)
852
{
853
    int err;
854
    struct stat stbuf;
855
    char buffer[PATH_MAX];
856

    
857
    if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
858
        err =  lstat(rpath(ctx, path, buffer), &stbuf);
859
        if (err) {
860
            goto err_out;
861
        }
862
        /*
863
         * If directory remove .virtfs_metadata contained in the
864
         * directory
865
         */
866
        if (S_ISDIR(stbuf.st_mode)) {
867
            sprintf(buffer, "%s/%s/%s", ctx->fs_root, path, VIRTFS_META_DIR);
868
            err = remove(buffer);
869
            if (err < 0 && errno != ENOENT) {
870
                /*
871
                 * We didn't had the .virtfs_metadata file. May be file created
872
                 * in non-mapped mode ?. Ignore ENOENT.
873
                 */
874
                goto err_out;
875
            }
876
        }
877
        /*
878
         * Now remove the name from parent directory
879
         * .virtfs_metadata directory
880
         */
881
        err = remove(local_mapped_attr_path(ctx, path, buffer));;
882
        if (err < 0 && errno != ENOENT) {
883
            /*
884
             * We didn't had the .virtfs_metadata file. May be file created
885
             * in non-mapped mode ?. Ignore ENOENT.
886
             */
887
            goto err_out;
888
        }
889
    }
890
    return remove(rpath(ctx, path, buffer));
891
err_out:
892
    return err;
893
}
894

    
895
static int local_fsync(FsContext *ctx, int fid_type,
896
                       V9fsFidOpenState *fs, int datasync)
897
{
898
    int fd;
899

    
900
    if (fid_type == P9_FID_DIR) {
901
        fd = dirfd(fs->dir);
902
    } else {
903
        fd = fs->fd;
904
    }
905

    
906
    if (datasync) {
907
        return qemu_fdatasync(fd);
908
    } else {
909
        return fsync(fd);
910
    }
911
}
912

    
913
static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
914
{
915
    char buffer[PATH_MAX];
916
    char *path = fs_path->data;
917

    
918
    return statfs(rpath(s, path, buffer), stbuf);
919
}
920

    
921
static ssize_t local_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
922
                               const char *name, void *value, size_t size)
923
{
924
    char *path = fs_path->data;
925

    
926
    return v9fs_get_xattr(ctx, path, name, value, size);
927
}
928

    
929
static ssize_t local_llistxattr(FsContext *ctx, V9fsPath *fs_path,
930
                                void *value, size_t size)
931
{
932
    char *path = fs_path->data;
933

    
934
    return v9fs_list_xattr(ctx, path, value, size);
935
}
936

    
937
static int local_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name,
938
                           void *value, size_t size, int flags)
939
{
940
    char *path = fs_path->data;
941

    
942
    return v9fs_set_xattr(ctx, path, name, value, size, flags);
943
}
944

    
945
static int local_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
946
                              const char *name)
947
{
948
    char *path = fs_path->data;
949

    
950
    return v9fs_remove_xattr(ctx, path, name);
951
}
952

    
953
static int local_name_to_path(FsContext *ctx, V9fsPath *dir_path,
954
                              const char *name, V9fsPath *target)
955
{
956
    if (dir_path) {
957
        v9fs_string_sprintf((V9fsString *)target, "%s/%s",
958
                            dir_path->data, name);
959
    } else {
960
        v9fs_string_sprintf((V9fsString *)target, "%s", name);
961
    }
962
    /* Bump the size for including terminating NULL */
963
    target->size++;
964
    return 0;
965
}
966

    
967
static int local_renameat(FsContext *ctx, V9fsPath *olddir,
968
                          const char *old_name, V9fsPath *newdir,
969
                          const char *new_name)
970
{
971
    int ret;
972
    V9fsString old_full_name, new_full_name;
973

    
974
    v9fs_string_init(&old_full_name);
975
    v9fs_string_init(&new_full_name);
976

    
977
    v9fs_string_sprintf(&old_full_name, "%s/%s", olddir->data, old_name);
978
    v9fs_string_sprintf(&new_full_name, "%s/%s", newdir->data, new_name);
979

    
980
    ret = local_rename(ctx, old_full_name.data, new_full_name.data);
981
    v9fs_string_free(&old_full_name);
982
    v9fs_string_free(&new_full_name);
983
    return ret;
984
}
985

    
986
static int local_unlinkat(FsContext *ctx, V9fsPath *dir,
987
                          const char *name, int flags)
988
{
989
    int ret;
990
    V9fsString fullname;
991
    char buffer[PATH_MAX];
992

    
993
    v9fs_string_init(&fullname);
994

    
995
    v9fs_string_sprintf(&fullname, "%s/%s", dir->data, name);
996
    if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
997
        if (flags == AT_REMOVEDIR) {
998
            /*
999
             * If directory remove .virtfs_metadata contained in the
1000
             * directory
1001
             */
1002
            sprintf(buffer, "%s/%s/%s", ctx->fs_root,
1003
                    fullname.data, VIRTFS_META_DIR);
1004
            ret = remove(buffer);
1005
            if (ret < 0 && errno != ENOENT) {
1006
                /*
1007
                 * We didn't had the .virtfs_metadata file. May be file created
1008
                 * in non-mapped mode ?. Ignore ENOENT.
1009
                 */
1010
                goto err_out;
1011
            }
1012
        }
1013
        /*
1014
         * Now remove the name from parent directory
1015
         * .virtfs_metadata directory.
1016
         */
1017
        ret = remove(local_mapped_attr_path(ctx, fullname.data, buffer));
1018
        if (ret < 0 && errno != ENOENT) {
1019
            /*
1020
             * We didn't had the .virtfs_metadata file. May be file created
1021
             * in non-mapped mode ?. Ignore ENOENT.
1022
             */
1023
            goto err_out;
1024
        }
1025
    }
1026
    /* Remove the name finally */
1027
    ret = remove(rpath(ctx, fullname.data, buffer));
1028
    v9fs_string_free(&fullname);
1029

    
1030
err_out:
1031
    return ret;
1032
}
1033

    
1034
static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
1035
                                mode_t st_mode, uint64_t *st_gen)
1036
{
1037
    int err;
1038
#ifdef FS_IOC_GETVERSION
1039
    V9fsFidOpenState fid_open;
1040

    
1041
    /*
1042
     * Do not try to open special files like device nodes, fifos etc
1043
     * We can get fd for regular files and directories only
1044
     */
1045
    if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
1046
            return 0;
1047
    }
1048
    err = local_open(ctx, path, O_RDONLY, &fid_open);
1049
    if (err < 0) {
1050
        return err;
1051
    }
1052
    err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
1053
    local_close(ctx, &fid_open);
1054
#else
1055
    err = -ENOTTY;
1056
#endif
1057
    return err;
1058
}
1059

    
1060
static int local_init(FsContext *ctx)
1061
{
1062
    int err = 0;
1063
    struct statfs stbuf;
1064

    
1065
    if (ctx->export_flags & V9FS_SM_PASSTHROUGH) {
1066
        ctx->xops = passthrough_xattr_ops;
1067
    } else if (ctx->export_flags & V9FS_SM_MAPPED) {
1068
        ctx->xops = mapped_xattr_ops;
1069
    } else if (ctx->export_flags & V9FS_SM_NONE) {
1070
        ctx->xops = none_xattr_ops;
1071
    } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
1072
        /*
1073
         * xattr operation for mapped-file and passthrough
1074
         * remain same.
1075
         */
1076
        ctx->xops = passthrough_xattr_ops;
1077
    }
1078
    ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT;
1079
#ifdef FS_IOC_GETVERSION
1080
    /*
1081
     * use ioc_getversion only if the iocl is definied
1082
     */
1083
    err = statfs(ctx->fs_root, &stbuf);
1084
    if (!err) {
1085
        switch (stbuf.f_type) {
1086
        case EXT2_SUPER_MAGIC:
1087
        case BTRFS_SUPER_MAGIC:
1088
        case REISERFS_SUPER_MAGIC:
1089
        case XFS_SUPER_MAGIC:
1090
            ctx->exops.get_st_gen = local_ioc_getversion;
1091
            break;
1092
        }
1093
    }
1094
#endif
1095
    return err;
1096
}
1097

    
1098
static int local_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse)
1099
{
1100
    const char *sec_model = qemu_opt_get(opts, "security_model");
1101
    const char *path = qemu_opt_get(opts, "path");
1102

    
1103
    if (!sec_model) {
1104
        fprintf(stderr, "security model not specified, "
1105
                "local fs needs security model\nvalid options are:"
1106
                "\tsecurity_model=[passthrough|mapped|none]\n");
1107
        return -1;
1108
    }
1109

    
1110
    if (!strcmp(sec_model, "passthrough")) {
1111
        fse->export_flags |= V9FS_SM_PASSTHROUGH;
1112
    } else if (!strcmp(sec_model, "mapped") ||
1113
               !strcmp(sec_model, "mapped-xattr")) {
1114
        fse->export_flags |= V9FS_SM_MAPPED;
1115
    } else if (!strcmp(sec_model, "none")) {
1116
        fse->export_flags |= V9FS_SM_NONE;
1117
    } else if (!strcmp(sec_model, "mapped-file")) {
1118
        fse->export_flags |= V9FS_SM_MAPPED_FILE;
1119
    } else {
1120
        fprintf(stderr, "Invalid security model %s specified, valid options are"
1121
                "\n\t [passthrough|mapped-xattr|mapped-file|none]\n",
1122
                sec_model);
1123
        return -1;
1124
    }
1125

    
1126
    if (!path) {
1127
        fprintf(stderr, "fsdev: No path specified.\n");
1128
        return -1;
1129
    }
1130
    fse->path = g_strdup(path);
1131

    
1132
    return 0;
1133
}
1134

    
1135
FileOperations local_ops = {
1136
    .parse_opts = local_parse_opts,
1137
    .init  = local_init,
1138
    .lstat = local_lstat,
1139
    .readlink = local_readlink,
1140
    .close = local_close,
1141
    .closedir = local_closedir,
1142
    .open = local_open,
1143
    .opendir = local_opendir,
1144
    .rewinddir = local_rewinddir,
1145
    .telldir = local_telldir,
1146
    .readdir_r = local_readdir_r,
1147
    .seekdir = local_seekdir,
1148
    .preadv = local_preadv,
1149
    .pwritev = local_pwritev,
1150
    .chmod = local_chmod,
1151
    .mknod = local_mknod,
1152
    .mkdir = local_mkdir,
1153
    .fstat = local_fstat,
1154
    .open2 = local_open2,
1155
    .symlink = local_symlink,
1156
    .link = local_link,
1157
    .truncate = local_truncate,
1158
    .rename = local_rename,
1159
    .chown = local_chown,
1160
    .utimensat = local_utimensat,
1161
    .remove = local_remove,
1162
    .fsync = local_fsync,
1163
    .statfs = local_statfs,
1164
    .lgetxattr = local_lgetxattr,
1165
    .llistxattr = local_llistxattr,
1166
    .lsetxattr = local_lsetxattr,
1167
    .lremovexattr = local_lremovexattr,
1168
    .name_to_path = local_name_to_path,
1169
    .renameat  = local_renameat,
1170
    .unlinkat = local_unlinkat,
1171
};