qemu/hw/9pfs/virtio-9p-local.c
Aneesh Kumar K.V 532decb715 hw/9pfs: Add fs driver specific details to fscontext
Add a new context flag PATHNAME_FSCONTEXT and indicate whether
the fs driver track fid using path names. Also add a private
pointer that help us to track fs driver specific values in there

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2011-09-22 21:38:52 +05:30

690 lines
18 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 <attr/xattr.h>
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->fs_sm == 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->fs_sm != 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->fs_sm == 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->fs_sm == SM_PASSTHROUGH) ||
(fs_ctx->fs_sm == SM_NONE)) {
tsize = readlink(rpath(fs_ctx, path, buffer), buf, bufsz);
}
return tsize;
}
static int local_close(FsContext *ctx, int fd)
{
return close(fd);
}
static int local_closedir(FsContext *ctx, DIR *dir)
{
return closedir(dir);
}
static int local_open(FsContext *ctx, V9fsPath *fs_path, int flags)
{
char buffer[PATH_MAX];
char *path = fs_path->data;
return open(rpath(ctx, path, buffer), flags);
}
static DIR *local_opendir(FsContext *ctx, V9fsPath *fs_path)
{
char buffer[PATH_MAX];
char *path = fs_path->data;
return opendir(rpath(ctx, path, buffer));
}
static void local_rewinddir(FsContext *ctx, DIR *dir)
{
return rewinddir(dir);
}
static off_t local_telldir(FsContext *ctx, DIR *dir)
{
return telldir(dir);
}
static int local_readdir_r(FsContext *ctx, DIR *dir, struct dirent *entry,
struct dirent **result)
{
return readdir_r(dir, entry, result);
}
static void local_seekdir(FsContext *ctx, DIR *dir, off_t off)
{
return seekdir(dir, off);
}
static ssize_t local_preadv(FsContext *ctx, int fd, const struct iovec *iov,
int iovcnt, off_t offset)
{
#ifdef CONFIG_PREADV
return preadv(fd, iov, iovcnt, offset);
#else
int err = lseek(fd, offset, SEEK_SET);
if (err == -1) {
return err;
} else {
return readv(fd, iov, iovcnt);
}
#endif
}
static ssize_t local_pwritev(FsContext *ctx, int fd, const struct iovec *iov,
int iovcnt, off_t offset)
{
#ifdef CONFIG_PREADV
return pwritev(fd, iov, iovcnt, offset);
#else
int err = lseek(fd, offset, SEEK_SET);
if (err == -1) {
return err;
} else {
return writev(fd, iov, iovcnt);
}
#endif
}
static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
{
char buffer[PATH_MAX];
char *path = fs_path->data;
if (fs_ctx->fs_sm == SM_MAPPED) {
return local_set_xattr(rpath(fs_ctx, path, buffer), credp);
} else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
(fs_ctx->fs_sm == 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->fs_sm == SM_MAPPED) {
err = mknod(rpath(fs_ctx, path, buffer),
SM_LOCAL_MODE_BITS|S_IFREG, 0);
if (err == -1) {
goto out;
}
local_set_xattr(rpath(fs_ctx, path, buffer), credp);
if (err == -1) {
serrno = errno;
goto err_end;
}
} else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
(fs_ctx->fs_sm == 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->fs_sm == 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->fs_sm == SM_PASSTHROUGH) ||
(fs_ctx->fs_sm == 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 fd, struct stat *stbuf)
{
int err;
err = fstat(fd, stbuf);
if (err) {
return err;
}
if (fs_ctx->fs_sm == 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)
{
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->fs_sm == 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->fs_sm == SM_PASSTHROUGH) ||
(fs_ctx->fs_sm == 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;
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->fs_sm == 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->fs_sm == SM_PASSTHROUGH) ||
(fs_ctx->fs_sm == 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->fs_sm != 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->fs_sm == SM_PASSTHROUGH)) {
return lchown(rpath(fs_ctx, path, buffer), credp->fc_uid,
credp->fc_gid);
} else if (fs_ctx->fs_sm == SM_MAPPED) {
return local_set_xattr(rpath(fs_ctx, path, buffer), credp);
} else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
(fs_ctx->fs_sm == SM_NONE)) {
return lchown(rpath(fs_ctx, path, buffer), credp->fc_uid,
credp->fc_gid);
}
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_utimensat(AT_FDCWD, rpath(s, path, buffer), buf,
AT_SYMLINK_NOFOLLOW);
}
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 fd, int datasync)
{
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_init(FsContext *ctx)
{
ctx->flags |= PATHNAME_FSCONTEXT;
return 0;
}
FileOperations local_ops = {
.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,
};