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14#include "qemu/osdep.h"
15#include "9p.h"
16#include "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 "qemu/cutils.h"
24#include "qemu/error-report.h"
25#include "qemu/option.h"
26#include <linux/fs.h>
27#ifdef CONFIG_LINUX_MAGIC_H
28#include <linux/magic.h>
29#endif
30#include <sys/ioctl.h>
31
32#ifndef XFS_SUPER_MAGIC
33#define XFS_SUPER_MAGIC 0x58465342
34#endif
35#ifndef EXT2_SUPER_MAGIC
36#define EXT2_SUPER_MAGIC 0xEF53
37#endif
38#ifndef REISERFS_SUPER_MAGIC
39#define REISERFS_SUPER_MAGIC 0x52654973
40#endif
41#ifndef BTRFS_SUPER_MAGIC
42#define BTRFS_SUPER_MAGIC 0x9123683E
43#endif
44
45typedef struct HandleData {
46 int mountfd;
47 int handle_bytes;
48} HandleData;
49
50static inline int name_to_handle(int dirfd, const char *name,
51 struct file_handle *fh, int *mnt_id, int flags)
52{
53 return name_to_handle_at(dirfd, name, fh, mnt_id, flags);
54}
55
56static inline int open_by_handle(int mountfd, const char *fh, int flags)
57{
58 return open_by_handle_at(mountfd, (struct file_handle *)fh, flags);
59}
60
61static int handle_update_file_cred(int dirfd, const char *name, FsCred *credp)
62{
63 int fd, ret;
64 fd = openat(dirfd, name, O_NONBLOCK | O_NOFOLLOW);
65 if (fd < 0) {
66 return fd;
67 }
68 ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
69 if (ret < 0) {
70 goto err_out;
71 }
72 ret = fchmod(fd, credp->fc_mode & 07777);
73err_out:
74 close(fd);
75 return ret;
76}
77
78
79static int handle_lstat(FsContext *fs_ctx, V9fsPath *fs_path,
80 struct stat *stbuf)
81{
82 int fd, ret;
83 HandleData *data = (HandleData *) fs_ctx->private;
84
85 fd = open_by_handle(data->mountfd, fs_path->data, O_PATH);
86 if (fd < 0) {
87 return fd;
88 }
89 ret = fstatat(fd, "", stbuf, AT_EMPTY_PATH);
90 close(fd);
91 return ret;
92}
93
94static ssize_t handle_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
95 char *buf, size_t bufsz)
96{
97 int fd, ret;
98 HandleData *data = (HandleData *) fs_ctx->private;
99
100 fd = open_by_handle(data->mountfd, fs_path->data, O_PATH);
101 if (fd < 0) {
102 return fd;
103 }
104 ret = readlinkat(fd, "", buf, bufsz);
105 close(fd);
106 return ret;
107}
108
109static int handle_close(FsContext *ctx, V9fsFidOpenState *fs)
110{
111 return close(fs->fd);
112}
113
114static int handle_closedir(FsContext *ctx, V9fsFidOpenState *fs)
115{
116 return closedir(fs->dir.stream);
117}
118
119static int handle_open(FsContext *ctx, V9fsPath *fs_path,
120 int flags, V9fsFidOpenState *fs)
121{
122 HandleData *data = (HandleData *) ctx->private;
123
124 fs->fd = open_by_handle(data->mountfd, fs_path->data, flags);
125 return fs->fd;
126}
127
128static int handle_opendir(FsContext *ctx,
129 V9fsPath *fs_path, V9fsFidOpenState *fs)
130{
131 int ret;
132 ret = handle_open(ctx, fs_path, O_DIRECTORY, fs);
133 if (ret < 0) {
134 return -1;
135 }
136 fs->dir.stream = fdopendir(ret);
137 if (!fs->dir.stream) {
138 return -1;
139 }
140 return 0;
141}
142
143static void handle_rewinddir(FsContext *ctx, V9fsFidOpenState *fs)
144{
145 rewinddir(fs->dir.stream);
146}
147
148static off_t handle_telldir(FsContext *ctx, V9fsFidOpenState *fs)
149{
150 return telldir(fs->dir.stream);
151}
152
153static struct dirent *handle_readdir(FsContext *ctx, V9fsFidOpenState *fs)
154{
155 return readdir(fs->dir.stream);
156}
157
158static void handle_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off)
159{
160 seekdir(fs->dir.stream, off);
161}
162
163static ssize_t handle_preadv(FsContext *ctx, V9fsFidOpenState *fs,
164 const struct iovec *iov,
165 int iovcnt, off_t offset)
166{
167#ifdef CONFIG_PREADV
168 return preadv(fs->fd, iov, iovcnt, offset);
169#else
170 int err = lseek(fs->fd, offset, SEEK_SET);
171 if (err == -1) {
172 return err;
173 } else {
174 return readv(fs->fd, iov, iovcnt);
175 }
176#endif
177}
178
179static ssize_t handle_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
180 const struct iovec *iov,
181 int iovcnt, off_t offset)
182{
183 ssize_t ret;
184#ifdef CONFIG_PREADV
185 ret = pwritev(fs->fd, iov, iovcnt, offset);
186#else
187 int err = lseek(fs->fd, offset, SEEK_SET);
188 if (err == -1) {
189 return err;
190 } else {
191 ret = writev(fs->fd, iov, iovcnt);
192 }
193#endif
194#ifdef CONFIG_SYNC_FILE_RANGE
195 if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) {
196
197
198
199
200
201 sync_file_range(fs->fd, offset, ret,
202 SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE);
203 }
204#endif
205 return ret;
206}
207
208static int handle_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
209{
210 int fd, ret;
211 HandleData *data = (HandleData *) fs_ctx->private;
212
213 fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
214 if (fd < 0) {
215 return fd;
216 }
217 ret = fchmod(fd, credp->fc_mode);
218 close(fd);
219 return ret;
220}
221
222static int handle_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
223 const char *name, FsCred *credp)
224{
225 int dirfd, ret;
226 HandleData *data = (HandleData *) fs_ctx->private;
227
228 dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
229 if (dirfd < 0) {
230 return dirfd;
231 }
232 ret = mknodat(dirfd, name, credp->fc_mode, credp->fc_rdev);
233 if (!ret) {
234 ret = handle_update_file_cred(dirfd, name, credp);
235 }
236 close(dirfd);
237 return ret;
238}
239
240static int handle_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
241 const char *name, FsCred *credp)
242{
243 int dirfd, ret;
244 HandleData *data = (HandleData *) fs_ctx->private;
245
246 dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
247 if (dirfd < 0) {
248 return dirfd;
249 }
250 ret = mkdirat(dirfd, name, credp->fc_mode);
251 if (!ret) {
252 ret = handle_update_file_cred(dirfd, name, credp);
253 }
254 close(dirfd);
255 return ret;
256}
257
258static int handle_fstat(FsContext *fs_ctx, int fid_type,
259 V9fsFidOpenState *fs, struct stat *stbuf)
260{
261 int fd;
262
263 if (fid_type == P9_FID_DIR) {
264 fd = dirfd(fs->dir.stream);
265 } else {
266 fd = fs->fd;
267 }
268 return fstat(fd, stbuf);
269}
270
271static int handle_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
272 int flags, FsCred *credp, V9fsFidOpenState *fs)
273{
274 int ret;
275 int dirfd, fd;
276 HandleData *data = (HandleData *) fs_ctx->private;
277
278 dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
279 if (dirfd < 0) {
280 return dirfd;
281 }
282 fd = openat(dirfd, name, flags | O_NOFOLLOW, credp->fc_mode);
283 if (fd >= 0) {
284 ret = handle_update_file_cred(dirfd, name, credp);
285 if (ret < 0) {
286 close(fd);
287 fd = ret;
288 } else {
289 fs->fd = fd;
290 }
291 }
292 close(dirfd);
293 return fd;
294}
295
296
297static int handle_symlink(FsContext *fs_ctx, const char *oldpath,
298 V9fsPath *dir_path, const char *name, FsCred *credp)
299{
300 int fd, dirfd, ret;
301 HandleData *data = (HandleData *) fs_ctx->private;
302
303 dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
304 if (dirfd < 0) {
305 return dirfd;
306 }
307 ret = symlinkat(oldpath, dirfd, name);
308 if (!ret) {
309 fd = openat(dirfd, name, O_PATH | O_NOFOLLOW);
310 if (fd < 0) {
311 ret = fd;
312 goto err_out;
313 }
314 ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
315 close(fd);
316 }
317err_out:
318 close(dirfd);
319 return ret;
320}
321
322static int handle_link(FsContext *ctx, V9fsPath *oldpath,
323 V9fsPath *dirpath, const char *name)
324{
325 int oldfd, newdirfd, ret;
326 HandleData *data = (HandleData *) ctx->private;
327
328 oldfd = open_by_handle(data->mountfd, oldpath->data, O_PATH);
329 if (oldfd < 0) {
330 return oldfd;
331 }
332 newdirfd = open_by_handle(data->mountfd, dirpath->data, O_PATH);
333 if (newdirfd < 0) {
334 close(oldfd);
335 return newdirfd;
336 }
337 ret = linkat(oldfd, "", newdirfd, name, AT_EMPTY_PATH);
338 close(newdirfd);
339 close(oldfd);
340 return ret;
341}
342
343static int handle_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
344{
345 int fd, ret;
346 HandleData *data = (HandleData *) ctx->private;
347
348 fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK | O_WRONLY);
349 if (fd < 0) {
350 return fd;
351 }
352 ret = ftruncate(fd, size);
353 close(fd);
354 return ret;
355}
356
357static int handle_rename(FsContext *ctx, const char *oldpath,
358 const char *newpath)
359{
360 errno = EOPNOTSUPP;
361 return -1;
362}
363
364static int handle_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
365{
366 int fd, ret;
367 HandleData *data = (HandleData *) fs_ctx->private;
368
369 fd = open_by_handle(data->mountfd, fs_path->data, O_PATH);
370 if (fd < 0) {
371 return fd;
372 }
373 ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
374 close(fd);
375 return ret;
376}
377
378static int handle_utimensat(FsContext *ctx, V9fsPath *fs_path,
379 const struct timespec *buf)
380{
381 int ret;
382 int fd;
383 HandleData *data = (HandleData *) ctx->private;
384
385 fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
386 if (fd < 0) {
387 return fd;
388 }
389 ret = futimens(fd, buf);
390 close(fd);
391 return ret;
392}
393
394static int handle_remove(FsContext *ctx, const char *path)
395{
396 errno = EOPNOTSUPP;
397 return -1;
398}
399
400static int handle_fsync(FsContext *ctx, int fid_type,
401 V9fsFidOpenState *fs, int datasync)
402{
403 int fd;
404
405 if (fid_type == P9_FID_DIR) {
406 fd = dirfd(fs->dir.stream);
407 } else {
408 fd = fs->fd;
409 }
410
411 if (datasync) {
412 return qemu_fdatasync(fd);
413 } else {
414 return fsync(fd);
415 }
416}
417
418static int handle_statfs(FsContext *ctx, V9fsPath *fs_path,
419 struct statfs *stbuf)
420{
421 int fd, ret;
422 HandleData *data = (HandleData *) ctx->private;
423
424 fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
425 if (fd < 0) {
426 return fd;
427 }
428 ret = fstatfs(fd, stbuf);
429 close(fd);
430 return ret;
431}
432
433static ssize_t handle_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
434 const char *name, void *value, size_t size)
435{
436 int fd, ret;
437 HandleData *data = (HandleData *) ctx->private;
438
439 fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
440 if (fd < 0) {
441 return fd;
442 }
443 ret = fgetxattr(fd, name, value, size);
444 close(fd);
445 return ret;
446}
447
448static ssize_t handle_llistxattr(FsContext *ctx, V9fsPath *fs_path,
449 void *value, size_t size)
450{
451 int fd, ret;
452 HandleData *data = (HandleData *) ctx->private;
453
454 fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
455 if (fd < 0) {
456 return fd;
457 }
458 ret = flistxattr(fd, value, size);
459 close(fd);
460 return ret;
461}
462
463static int handle_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name,
464 void *value, size_t size, int flags)
465{
466 int fd, ret;
467 HandleData *data = (HandleData *) ctx->private;
468
469 fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
470 if (fd < 0) {
471 return fd;
472 }
473 ret = fsetxattr(fd, name, value, size, flags);
474 close(fd);
475 return ret;
476}
477
478static int handle_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
479 const char *name)
480{
481 int fd, ret;
482 HandleData *data = (HandleData *) ctx->private;
483
484 fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
485 if (fd < 0) {
486 return fd;
487 }
488 ret = fremovexattr(fd, name);
489 close(fd);
490 return ret;
491}
492
493static int handle_name_to_path(FsContext *ctx, V9fsPath *dir_path,
494 const char *name, V9fsPath *target)
495{
496 char *buffer;
497 struct file_handle *fh;
498 int dirfd, ret, mnt_id;
499 HandleData *data = (HandleData *) ctx->private;
500
501
502 if (!strcmp(name, ".") || !strcmp(name, "..")) {
503 errno = EINVAL;
504 return -1;
505
506 }
507 if (dir_path) {
508 dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
509 } else {
510
511 buffer = rpath(ctx, ".");
512 dirfd = open(buffer, O_DIRECTORY);
513 g_free(buffer);
514 }
515 if (dirfd < 0) {
516 return dirfd;
517 }
518 fh = g_malloc(sizeof(struct file_handle) + data->handle_bytes);
519 fh->handle_bytes = data->handle_bytes;
520
521 buffer = g_strdup_printf("./%s", name);
522
523 ret = name_to_handle(dirfd, buffer, fh, &mnt_id, 0);
524 if (!ret) {
525 target->data = (char *)fh;
526 target->size = sizeof(struct file_handle) + data->handle_bytes;
527 } else {
528 g_free(fh);
529 }
530 close(dirfd);
531 g_free(buffer);
532 return ret;
533}
534
535static int handle_renameat(FsContext *ctx, V9fsPath *olddir,
536 const char *old_name, V9fsPath *newdir,
537 const char *new_name)
538{
539 int olddirfd, newdirfd, ret;
540 HandleData *data = (HandleData *) ctx->private;
541
542 olddirfd = open_by_handle(data->mountfd, olddir->data, O_PATH);
543 if (olddirfd < 0) {
544 return olddirfd;
545 }
546 newdirfd = open_by_handle(data->mountfd, newdir->data, O_PATH);
547 if (newdirfd < 0) {
548 close(olddirfd);
549 return newdirfd;
550 }
551 ret = renameat(olddirfd, old_name, newdirfd, new_name);
552 close(newdirfd);
553 close(olddirfd);
554 return ret;
555}
556
557static int handle_unlinkat(FsContext *ctx, V9fsPath *dir,
558 const char *name, int flags)
559{
560 int dirfd, ret;
561 HandleData *data = (HandleData *) ctx->private;
562
563 dirfd = open_by_handle(data->mountfd, dir->data, O_PATH);
564 if (dirfd < 0) {
565 return dirfd;
566 }
567
568 ret = unlinkat(dirfd, name, flags);
569
570 close(dirfd);
571 return ret;
572}
573
574static int handle_ioc_getversion(FsContext *ctx, V9fsPath *path,
575 mode_t st_mode, uint64_t *st_gen)
576{
577#ifdef FS_IOC_GETVERSION
578 int err;
579 V9fsFidOpenState fid_open;
580
581
582
583
584
585 if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
586 errno = ENOTTY;
587 return -1;
588 }
589 err = handle_open(ctx, path, O_RDONLY, &fid_open);
590 if (err < 0) {
591 return err;
592 }
593 err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
594 handle_close(ctx, &fid_open);
595 return err;
596#else
597 errno = ENOTTY;
598 return -1;
599#endif
600}
601
602static int handle_init(FsContext *ctx, Error **errp)
603{
604 int ret, mnt_id;
605 struct statfs stbuf;
606 struct file_handle fh;
607 HandleData *data = g_malloc(sizeof(HandleData));
608
609 data->mountfd = open(ctx->fs_root, O_DIRECTORY);
610 if (data->mountfd < 0) {
611 ret = data->mountfd;
612 goto err_out;
613 }
614 ret = statfs(ctx->fs_root, &stbuf);
615 if (!ret) {
616 switch (stbuf.f_type) {
617 case EXT2_SUPER_MAGIC:
618 case BTRFS_SUPER_MAGIC:
619 case REISERFS_SUPER_MAGIC:
620 case XFS_SUPER_MAGIC:
621 ctx->exops.get_st_gen = handle_ioc_getversion;
622 break;
623 }
624 }
625 memset(&fh, 0, sizeof(struct file_handle));
626 ret = name_to_handle(data->mountfd, ".", &fh, &mnt_id, 0);
627 if (ret && errno == EOVERFLOW) {
628 data->handle_bytes = fh.handle_bytes;
629 ctx->private = data;
630 ret = 0;
631 goto out;
632 }
633
634 ret = -1;
635 close(data->mountfd);
636err_out:
637 g_free(data);
638out:
639 return ret;
640}
641
642static void handle_cleanup(FsContext *ctx)
643{
644 HandleData *data = ctx->private;
645
646 close(data->mountfd);
647 g_free(data);
648}
649
650static int handle_parse_opts(QemuOpts *opts, FsDriverEntry *fse, Error **errp)
651{
652 const char *sec_model = qemu_opt_get(opts, "security_model");
653 const char *path = qemu_opt_get(opts, "path");
654
655 warn_report("handle backend is deprecated");
656
657 if (sec_model) {
658 error_report("Invalid argument security_model specified with handle fsdriver");
659 return -1;
660 }
661
662 if (!path) {
663 error_report("fsdev: No path specified");
664 return -1;
665 }
666 fse->path = g_strdup(path);
667 return 0;
668
669}
670
671FileOperations handle_ops = {
672 .parse_opts = handle_parse_opts,
673 .init = handle_init,
674 .cleanup = handle_cleanup,
675 .lstat = handle_lstat,
676 .readlink = handle_readlink,
677 .close = handle_close,
678 .closedir = handle_closedir,
679 .open = handle_open,
680 .opendir = handle_opendir,
681 .rewinddir = handle_rewinddir,
682 .telldir = handle_telldir,
683 .readdir = handle_readdir,
684 .seekdir = handle_seekdir,
685 .preadv = handle_preadv,
686 .pwritev = handle_pwritev,
687 .chmod = handle_chmod,
688 .mknod = handle_mknod,
689 .mkdir = handle_mkdir,
690 .fstat = handle_fstat,
691 .open2 = handle_open2,
692 .symlink = handle_symlink,
693 .link = handle_link,
694 .truncate = handle_truncate,
695 .rename = handle_rename,
696 .chown = handle_chown,
697 .utimensat = handle_utimensat,
698 .remove = handle_remove,
699 .fsync = handle_fsync,
700 .statfs = handle_statfs,
701 .lgetxattr = handle_lgetxattr,
702 .llistxattr = handle_llistxattr,
703 .lsetxattr = handle_lsetxattr,
704 .lremovexattr = handle_lremovexattr,
705 .name_to_path = handle_name_to_path,
706 .renameat = handle_renameat,
707 .unlinkat = handle_unlinkat,
708};
709
