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

829 lines
22 KiB
C

/*
* Virtio 9p Posix callback
*
* Copyright IBM, Corp. 2010
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#include "hw/virtio.h"
#include "virtio-9p.h"
#include "virtio-9p-xattr.h"
#include <arpa/inet.h>
#include <pwd.h>
#include <grp.h>
#include <sys/socket.h>
#include <sys/un.h>
#include "qemu-xattr.h"
#include <linux/fs.h>
#ifdef CONFIG_LINUX_MAGIC_H
#include <linux/magic.h>
#endif
#include <sys/ioctl.h>
#ifndef XFS_SUPER_MAGIC
#define XFS_SUPER_MAGIC 0x58465342
#endif
#ifndef EXT2_SUPER_MAGIC
#define EXT2_SUPER_MAGIC 0xEF53
#endif
#ifndef REISERFS_SUPER_MAGIC
#define REISERFS_SUPER_MAGIC 0x52654973
#endif
#ifndef BTRFS_SUPER_MAGIC
#define BTRFS_SUPER_MAGIC 0x9123683E
#endif
static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
{
int err;
char buffer[PATH_MAX];
char *path = fs_path->data;
err = lstat(rpath(fs_ctx, path, buffer), stbuf);
if (err) {
return err;
}
if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
/* Actual credentials are part of extended attrs */
uid_t tmp_uid;
gid_t tmp_gid;
mode_t tmp_mode;
dev_t tmp_dev;
if (getxattr(rpath(fs_ctx, path, buffer), "user.virtfs.uid", &tmp_uid,
sizeof(uid_t)) > 0) {
stbuf->st_uid = tmp_uid;
}
if (getxattr(rpath(fs_ctx, path, buffer), "user.virtfs.gid", &tmp_gid,
sizeof(gid_t)) > 0) {
stbuf->st_gid = tmp_gid;
}
if (getxattr(rpath(fs_ctx, path, buffer), "user.virtfs.mode",
&tmp_mode, sizeof(mode_t)) > 0) {
stbuf->st_mode = tmp_mode;
}
if (getxattr(rpath(fs_ctx, path, buffer), "user.virtfs.rdev", &tmp_dev,
sizeof(dev_t)) > 0) {
stbuf->st_rdev = tmp_dev;
}
}
return err;
}
static int local_set_xattr(const char *path, FsCred *credp)
{
int err;
if (credp->fc_uid != -1) {
err = setxattr(path, "user.virtfs.uid", &credp->fc_uid, sizeof(uid_t),
0);
if (err) {
return err;
}
}
if (credp->fc_gid != -1) {
err = setxattr(path, "user.virtfs.gid", &credp->fc_gid, sizeof(gid_t),
0);
if (err) {
return err;
}
}
if (credp->fc_mode != -1) {
err = setxattr(path, "user.virtfs.mode", &credp->fc_mode,
sizeof(mode_t), 0);
if (err) {
return err;
}
}
if (credp->fc_rdev != -1) {
err = setxattr(path, "user.virtfs.rdev", &credp->fc_rdev,
sizeof(dev_t), 0);
if (err) {
return err;
}
}
return 0;
}
static int local_post_create_passthrough(FsContext *fs_ctx, const char *path,
FsCred *credp)
{
char buffer[PATH_MAX];
if (chmod(rpath(fs_ctx, path, buffer), credp->fc_mode & 07777) < 0) {
return -1;
}
if (lchown(rpath(fs_ctx, path, buffer), credp->fc_uid,
credp->fc_gid) < 0) {
/*
* If we fail to change ownership and if we are
* using security model none. Ignore the error
*/
if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
return -1;
}
}
return 0;
}
static ssize_t local_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
char *buf, size_t bufsz)
{
ssize_t tsize = -1;
char buffer[PATH_MAX];
char *path = fs_path->data;
if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
int fd;
fd = open(rpath(fs_ctx, path, buffer), O_RDONLY);
if (fd == -1) {
return -1;
}
do {
tsize = read(fd, (void *)buf, bufsz);
} while (tsize == -1 && errno == EINTR);
close(fd);
return tsize;
} else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
(fs_ctx->export_flags & V9FS_SM_NONE)) {
tsize = readlink(rpath(fs_ctx, path, buffer), buf, bufsz);
}
return tsize;
}
static int local_close(FsContext *ctx, V9fsFidOpenState *fs)
{
return close(fs->fd);
}
static int local_closedir(FsContext *ctx, V9fsFidOpenState *fs)
{
return closedir(fs->dir);
}
static int local_open(FsContext *ctx, V9fsPath *fs_path,
int flags, V9fsFidOpenState *fs)
{
char buffer[PATH_MAX];
char *path = fs_path->data;
fs->fd = open(rpath(ctx, path, buffer), flags);
return fs->fd;
}
static int local_opendir(FsContext *ctx,
V9fsPath *fs_path, V9fsFidOpenState *fs)
{
char buffer[PATH_MAX];
char *path = fs_path->data;
fs->dir = opendir(rpath(ctx, path, buffer));
if (!fs->dir) {
return -1;
}
return 0;
}
static void local_rewinddir(FsContext *ctx, V9fsFidOpenState *fs)
{
return rewinddir(fs->dir);
}
static off_t local_telldir(FsContext *ctx, V9fsFidOpenState *fs)
{
return telldir(fs->dir);
}
static int local_readdir_r(FsContext *ctx, V9fsFidOpenState *fs,
struct dirent *entry,
struct dirent **result)
{
return readdir_r(fs->dir, entry, result);
}
static void local_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off)
{
return seekdir(fs->dir, off);
}
static ssize_t local_preadv(FsContext *ctx, V9fsFidOpenState *fs,
const struct iovec *iov,
int iovcnt, off_t offset)
{
#ifdef CONFIG_PREADV
return preadv(fs->fd, iov, iovcnt, offset);
#else
int err = lseek(fs->fd, offset, SEEK_SET);
if (err == -1) {
return err;
} else {
return readv(fs->fd, iov, iovcnt);
}
#endif
}
static ssize_t local_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
const struct iovec *iov,
int iovcnt, off_t offset)
{
ssize_t ret
;
#ifdef CONFIG_PREADV
ret = pwritev(fs->fd, iov, iovcnt, offset);
#else
int err = lseek(fs->fd, offset, SEEK_SET);
if (err == -1) {
return err;
} else {
ret = writev(fs->fd, iov, iovcnt);
}
#endif
#ifdef CONFIG_SYNC_FILE_RANGE
if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) {
/*
* Initiate a writeback. This is not a data integrity sync.
* We want to ensure that we don't leave dirty pages in the cache
* after write when writeout=immediate is sepcified.
*/
sync_file_range(fs->fd, offset, ret,
SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE);
}
#endif
return ret;
}
static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
{
char buffer[PATH_MAX];
char *path = fs_path->data;
if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
return local_set_xattr(rpath(fs_ctx, path, buffer), credp);
} else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
(fs_ctx->export_flags & V9FS_SM_NONE)) {
return chmod(rpath(fs_ctx, path, buffer), credp->fc_mode);
}
return -1;
}
static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
const char *name, FsCred *credp)
{
char *path;
int err = -1;
int serrno = 0;
V9fsString fullname;
char buffer[PATH_MAX];
v9fs_string_init(&fullname);
v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
path = fullname.data;
/* Determine the security model */
if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
err = mknod(rpath(fs_ctx, path, buffer),
SM_LOCAL_MODE_BITS|S_IFREG, 0);
if (err == -1) {
goto out;
}
err = local_set_xattr(rpath(fs_ctx, path, buffer), credp);
if (err == -1) {
serrno = errno;
goto err_end;
}
} else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
(fs_ctx->export_flags & V9FS_SM_NONE)) {
err = mknod(rpath(fs_ctx, path, buffer), credp->fc_mode,
credp->fc_rdev);
if (err == -1) {
goto out;
}
err = local_post_create_passthrough(fs_ctx, path, credp);
if (err == -1) {
serrno = errno;
goto err_end;
}
}
goto out;
err_end:
remove(rpath(fs_ctx, path, buffer));
errno = serrno;
out:
v9fs_string_free(&fullname);
return err;
}
static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
const char *name, FsCred *credp)
{
char *path;
int err = -1;
int serrno = 0;
V9fsString fullname;
char buffer[PATH_MAX];
v9fs_string_init(&fullname);
v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
path = fullname.data;
/* Determine the security model */
if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
err = mkdir(rpath(fs_ctx, path, buffer), SM_LOCAL_DIR_MODE_BITS);
if (err == -1) {
goto out;
}
credp->fc_mode = credp->fc_mode|S_IFDIR;
err = local_set_xattr(rpath(fs_ctx, path, buffer), credp);
if (err == -1) {
serrno = errno;
goto err_end;
}
} else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
(fs_ctx->export_flags & V9FS_SM_NONE)) {
err = mkdir(rpath(fs_ctx, path, buffer), credp->fc_mode);
if (err == -1) {
goto out;
}
err = local_post_create_passthrough(fs_ctx, path, credp);
if (err == -1) {
serrno = errno;
goto err_end;
}
}
goto out;
err_end:
remove(rpath(fs_ctx, path, buffer));
errno = serrno;
out:
v9fs_string_free(&fullname);
return err;
}
static int local_fstat(FsContext *fs_ctx, int fid_type,
V9fsFidOpenState *fs, struct stat *stbuf)
{
int err, fd;
if (fid_type == P9_FID_DIR) {
fd = dirfd(fs->dir);
} else {
fd = fs->fd;
}
err = fstat(fd, stbuf);
if (err) {
return err;
}
if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
/* Actual credentials are part of extended attrs */
uid_t tmp_uid;
gid_t tmp_gid;
mode_t tmp_mode;
dev_t tmp_dev;
if (fgetxattr(fd, "user.virtfs.uid",
&tmp_uid, sizeof(uid_t)) > 0) {
stbuf->st_uid = tmp_uid;
}
if (fgetxattr(fd, "user.virtfs.gid",
&tmp_gid, sizeof(gid_t)) > 0) {
stbuf->st_gid = tmp_gid;
}
if (fgetxattr(fd, "user.virtfs.mode",
&tmp_mode, sizeof(mode_t)) > 0) {
stbuf->st_mode = tmp_mode;
}
if (fgetxattr(fd, "user.virtfs.rdev",
&tmp_dev, sizeof(dev_t)) > 0) {
stbuf->st_rdev = tmp_dev;
}
}
return err;
}
static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
int flags, FsCred *credp, V9fsFidOpenState *fs)
{
char *path;
int fd = -1;
int err = -1;
int serrno = 0;
V9fsString fullname;
char buffer[PATH_MAX];
v9fs_string_init(&fullname);
v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
path = fullname.data;
/* Determine the security model */
if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
fd = open(rpath(fs_ctx, path, buffer), flags, SM_LOCAL_MODE_BITS);
if (fd == -1) {
err = fd;
goto out;
}
credp->fc_mode = credp->fc_mode|S_IFREG;
/* Set cleint credentials in xattr */
err = local_set_xattr(rpath(fs_ctx, path, buffer), credp);
if (err == -1) {
serrno = errno;
goto err_end;
}
} else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
(fs_ctx->export_flags & V9FS_SM_NONE)) {
fd = open(rpath(fs_ctx, path, buffer), flags, credp->fc_mode);
if (fd == -1) {
err = fd;
goto out;
}
err = local_post_create_passthrough(fs_ctx, path, credp);
if (err == -1) {
serrno = errno;
goto err_end;
}
}
err = fd;
fs->fd = fd;
goto out;
err_end:
close(fd);
remove(rpath(fs_ctx, path, buffer));
errno = serrno;
out:
v9fs_string_free(&fullname);
return err;
}
static int local_symlink(FsContext *fs_ctx, const char *oldpath,
V9fsPath *dir_path, const char *name, FsCred *credp)
{
int err = -1;
int serrno = 0;
char *newpath;
V9fsString fullname;
char buffer[PATH_MAX];
v9fs_string_init(&fullname);
v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
newpath = fullname.data;
/* Determine the security model */
if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
int fd;
ssize_t oldpath_size, write_size;
fd = open(rpath(fs_ctx, newpath, buffer), O_CREAT|O_EXCL|O_RDWR,
SM_LOCAL_MODE_BITS);
if (fd == -1) {
err = fd;
goto out;
}
/* Write the oldpath (target) to the file. */
oldpath_size = strlen(oldpath);
do {
write_size = write(fd, (void *)oldpath, oldpath_size);
} while (write_size == -1 && errno == EINTR);
if (write_size != oldpath_size) {
serrno = errno;
close(fd);
err = -1;
goto err_end;
}
close(fd);
/* Set cleint credentials in symlink's xattr */
credp->fc_mode = credp->fc_mode|S_IFLNK;
err = local_set_xattr(rpath(fs_ctx, newpath, buffer), credp);
if (err == -1) {
serrno = errno;
goto err_end;
}
} else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
(fs_ctx->export_flags & V9FS_SM_NONE)) {
err = symlink(oldpath, rpath(fs_ctx, newpath, buffer));
if (err) {
goto out;
}
err = lchown(rpath(fs_ctx, newpath, buffer), credp->fc_uid,
credp->fc_gid);
if (err == -1) {
/*
* If we fail to change ownership and if we are
* using security model none. Ignore the error
*/
if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
serrno = errno;
goto err_end;
} else
err = 0;
}
}
goto out;
err_end:
remove(rpath(fs_ctx, newpath, buffer));
errno = serrno;
out:
v9fs_string_free(&fullname);
return err;
}
static int local_link(FsContext *ctx, V9fsPath *oldpath,
V9fsPath *dirpath, const char *name)
{
int ret;
V9fsString newpath;
char buffer[PATH_MAX], buffer1[PATH_MAX];
v9fs_string_init(&newpath);
v9fs_string_sprintf(&newpath, "%s/%s", dirpath->data, name);
ret = link(rpath(ctx, oldpath->data, buffer),
rpath(ctx, newpath.data, buffer1));
v9fs_string_free(&newpath);
return ret;
}
static int local_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
{
char buffer[PATH_MAX];
char *path = fs_path->data;
return truncate(rpath(ctx, path, buffer), size);
}
static int local_rename(FsContext *ctx, const char *oldpath,
const char *newpath)
{
char buffer[PATH_MAX], buffer1[PATH_MAX];
return rename(rpath(ctx, oldpath, buffer), rpath(ctx, newpath, buffer1));
}
static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
{
char buffer[PATH_MAX];
char *path = fs_path->data;
if ((credp->fc_uid == -1 && credp->fc_gid == -1) ||
(fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
(fs_ctx->export_flags & V9FS_SM_NONE)) {
return lchown(rpath(fs_ctx, path, buffer),
credp->fc_uid, credp->fc_gid);
} else if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
return local_set_xattr(rpath(fs_ctx, path, buffer), credp);
}
return -1;
}
static int local_utimensat(FsContext *s, V9fsPath *fs_path,
const struct timespec *buf)
{
char buffer[PATH_MAX];
char *path = fs_path->data;
return qemu_utimens(rpath(s, path, buffer), buf);
}
static int local_remove(FsContext *ctx, const char *path)
{
char buffer[PATH_MAX];
return remove(rpath(ctx, path, buffer));
}
static int local_fsync(FsContext *ctx, int fid_type,
V9fsFidOpenState *fs, int datasync)
{
int fd;
if (fid_type == P9_FID_DIR) {
fd = dirfd(fs->dir);
} else {
fd = fs->fd;
}
if (datasync) {
return qemu_fdatasync(fd);
} else {
return fsync(fd);
}
}
static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
{
char buffer[PATH_MAX];
char *path = fs_path->data;
return statfs(rpath(s, path, buffer), stbuf);
}
static ssize_t local_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
const char *name, void *value, size_t size)
{
char *path = fs_path->data;
return v9fs_get_xattr(ctx, path, name, value, size);
}
static ssize_t local_llistxattr(FsContext *ctx, V9fsPath *fs_path,
void *value, size_t size)
{
char *path = fs_path->data;
return v9fs_list_xattr(ctx, path, value, size);
}
static int local_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name,
void *value, size_t size, int flags)
{
char *path = fs_path->data;
return v9fs_set_xattr(ctx, path, name, value, size, flags);
}
static int local_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
const char *name)
{
char *path = fs_path->data;
return v9fs_remove_xattr(ctx, path, name);
}
static int local_name_to_path(FsContext *ctx, V9fsPath *dir_path,
const char *name, V9fsPath *target)
{
if (dir_path) {
v9fs_string_sprintf((V9fsString *)target, "%s/%s",
dir_path->data, name);
} else {
v9fs_string_sprintf((V9fsString *)target, "%s", name);
}
/* Bump the size for including terminating NULL */
target->size++;
return 0;
}
static int local_renameat(FsContext *ctx, V9fsPath *olddir,
const char *old_name, V9fsPath *newdir,
const char *new_name)
{
int ret;
V9fsString old_full_name, new_full_name;
v9fs_string_init(&old_full_name);
v9fs_string_init(&new_full_name);
v9fs_string_sprintf(&old_full_name, "%s/%s", olddir->data, old_name);
v9fs_string_sprintf(&new_full_name, "%s/%s", newdir->data, new_name);
ret = local_rename(ctx, old_full_name.data, new_full_name.data);
v9fs_string_free(&old_full_name);
v9fs_string_free(&new_full_name);
return ret;
}
static int local_unlinkat(FsContext *ctx, V9fsPath *dir,
const char *name, int flags)
{
int ret;
V9fsString fullname;
char buffer[PATH_MAX];
v9fs_string_init(&fullname);
v9fs_string_sprintf(&fullname, "%s/%s", dir->data, name);
ret = remove(rpath(ctx, fullname.data, buffer));
v9fs_string_free(&fullname);
return ret;
}
static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
mode_t st_mode, uint64_t *st_gen)
{
int err;
#ifdef FS_IOC_GETVERSION
V9fsFidOpenState fid_open;
/*
* Do not try to open special files like device nodes, fifos etc
* We can get fd for regular files and directories only
*/
if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
return 0;
}
err = local_open(ctx, path, O_RDONLY, &fid_open);
if (err < 0) {
return err;
}
err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
local_close(ctx, &fid_open);
#else
err = -ENOTTY;
#endif
return err;
}
static int local_init(FsContext *ctx)
{
int err = 0;
struct statfs stbuf;
ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT;
#ifdef FS_IOC_GETVERSION
/*
* use ioc_getversion only if the iocl is definied
*/
err = statfs(ctx->fs_root, &stbuf);
if (!err) {
switch (stbuf.f_type) {
case EXT2_SUPER_MAGIC:
case BTRFS_SUPER_MAGIC:
case REISERFS_SUPER_MAGIC:
case XFS_SUPER_MAGIC:
ctx->exops.get_st_gen = local_ioc_getversion;
break;
}
}
#endif
return err;
}
static int local_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse)
{
const char *sec_model = qemu_opt_get(opts, "security_model");
const char *path = qemu_opt_get(opts, "path");
if (!sec_model) {
fprintf(stderr, "security model not specified, "
"local fs needs security model\nvalid options are:"
"\tsecurity_model=[passthrough|mapped|none]\n");
return -1;
}
if (!strcmp(sec_model, "passthrough")) {
fse->export_flags |= V9FS_SM_PASSTHROUGH;
} else if (!strcmp(sec_model, "mapped")) {
fse->export_flags |= V9FS_SM_MAPPED;
} else if (!strcmp(sec_model, "none")) {
fse->export_flags |= V9FS_SM_NONE;
} else {
fprintf(stderr, "Invalid security model %s specified, valid options are"
"\n\t [passthrough|mapped|none]\n", sec_model);
return -1;
}
if (!path) {
fprintf(stderr, "fsdev: No path specified.\n");
return -1;
}
fse->path = g_strdup(path);
return 0;
}
FileOperations local_ops = {
.parse_opts = local_parse_opts,
.init = local_init,
.lstat = local_lstat,
.readlink = local_readlink,
.close = local_close,
.closedir = local_closedir,
.open = local_open,
.opendir = local_opendir,
.rewinddir = local_rewinddir,
.telldir = local_telldir,
.readdir_r = local_readdir_r,
.seekdir = local_seekdir,
.preadv = local_preadv,
.pwritev = local_pwritev,
.chmod = local_chmod,
.mknod = local_mknod,
.mkdir = local_mkdir,
.fstat = local_fstat,
.open2 = local_open2,
.symlink = local_symlink,
.link = local_link,
.truncate = local_truncate,
.rename = local_rename,
.chown = local_chown,
.utimensat = local_utimensat,
.remove = local_remove,
.fsync = local_fsync,
.statfs = local_statfs,
.lgetxattr = local_lgetxattr,
.llistxattr = local_llistxattr,
.lsetxattr = local_lsetxattr,
.lremovexattr = local_lremovexattr,
.name_to_path = local_name_to_path,
.renameat = local_renameat,
.unlinkat = local_unlinkat,
};