qemu/hw/virtio-9p-local.c
Venkateswararao Jujjuri (JV) 00ec5c3760 virtio-9p: Security model for mkdir
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-06-22 15:15:51 -05:00

430 lines
10 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 "virtio.h"
#include "virtio-9p.h"
#include <arpa/inet.h>
#include <pwd.h>
#include <grp.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <attr/xattr.h>
static const char *rpath(FsContext *ctx, const char *path)
{
/* FIXME: so wrong... */
static char buffer[4096];
snprintf(buffer, sizeof(buffer), "%s/%s", ctx->fs_root, path);
return buffer;
}
static int local_lstat(FsContext *fs_ctx, const char *path, struct stat *stbuf)
{
int err;
err = lstat(rpath(fs_ctx, path), 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), "user.virtfs.uid", &tmp_uid,
sizeof(uid_t)) > 0) {
stbuf->st_uid = tmp_uid;
}
if (getxattr(rpath(fs_ctx, path), "user.virtfs.gid", &tmp_gid,
sizeof(gid_t)) > 0) {
stbuf->st_gid = tmp_gid;
}
if (getxattr(rpath(fs_ctx, path), "user.virtfs.mode", &tmp_mode,
sizeof(mode_t)) > 0) {
stbuf->st_mode = tmp_mode;
}
if (getxattr(rpath(fs_ctx, path), "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)
{
if (chmod(rpath(fs_ctx, path), credp->fc_mode & 07777) < 0) {
return -1;
}
if (chown(rpath(fs_ctx, path), credp->fc_uid, credp->fc_gid) < 0) {
return -1;
}
return 0;
}
static ssize_t local_readlink(FsContext *ctx, const char *path,
char *buf, size_t bufsz)
{
return readlink(rpath(ctx, path), buf, bufsz);
}
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, const char *path, int flags)
{
return open(rpath(ctx, path), flags);
}
static DIR *local_opendir(FsContext *ctx, const char *path)
{
return opendir(rpath(ctx, path));
}
static void local_rewinddir(FsContext *ctx, DIR *dir)
{
return rewinddir(dir);
}
static off_t local_telldir(FsContext *ctx, DIR *dir)
{
return telldir(dir);
}
static struct dirent *local_readdir(FsContext *ctx, DIR *dir)
{
return readdir(dir);
}
static void local_seekdir(FsContext *ctx, DIR *dir, off_t off)
{
return seekdir(dir, off);
}
static ssize_t local_readv(FsContext *ctx, int fd, const struct iovec *iov,
int iovcnt)
{
return readv(fd, iov, iovcnt);
}
static off_t local_lseek(FsContext *ctx, int fd, off_t offset, int whence)
{
return lseek(fd, offset, whence);
}
static ssize_t local_writev(FsContext *ctx, int fd, const struct iovec *iov,
int iovcnt)
{
return writev(fd, iov, iovcnt);
}
static int local_chmod(FsContext *fs_ctx, const char *path, FsCred *credp)
{
if (fs_ctx->fs_sm == SM_MAPPED) {
return local_set_xattr(rpath(fs_ctx, path), credp);
} else if (fs_ctx->fs_sm == SM_PASSTHROUGH) {
return chmod(rpath(fs_ctx, path), credp->fc_mode);
}
return -1;
}
static int local_mknod(FsContext *ctx, const char *path, mode_t mode, dev_t dev)
{
return mknod(rpath(ctx, path), mode, dev);
}
static int local_mksock(FsContext *ctx2, const char *path)
{
struct sockaddr_un addr;
int s;
addr.sun_family = AF_UNIX;
snprintf(addr.sun_path, 108, "%s", rpath(ctx2, path));
s = socket(PF_UNIX, SOCK_STREAM, 0);
if (s == -1) {
return -1;
}
if (bind(s, (struct sockaddr *)&addr, sizeof(addr))) {
close(s);
return -1;
}
close(s);
return 0;
}
static int local_mkdir(FsContext *fs_ctx, const char *path, FsCred *credp)
{
int err = -1;
int serrno = 0;
/* Determine the security model */
if (fs_ctx->fs_sm == SM_MAPPED) {
err = mkdir(rpath(fs_ctx, path), SM_LOCAL_DIR_MODE_BITS);
if (err == -1) {
return err;
}
credp->fc_mode = credp->fc_mode|S_IFDIR;
err = local_set_xattr(rpath(fs_ctx, path), credp);
if (err == -1) {
serrno = errno;
goto err_end;
}
} else if (fs_ctx->fs_sm == SM_PASSTHROUGH) {
err = mkdir(rpath(fs_ctx, path), credp->fc_mode);
if (err == -1) {
return err;
}
err = local_post_create_passthrough(fs_ctx, path, credp);
if (err == -1) {
serrno = errno;
goto err_end;
}
}
return err;
err_end:
remove(rpath(fs_ctx, path));
errno = serrno;
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, const char *path, int flags,
FsCred *credp)
{
int fd = -1;
int err = -1;
int serrno = 0;
/* Determine the security model */
if (fs_ctx->fs_sm == SM_MAPPED) {
fd = open(rpath(fs_ctx, path), flags, SM_LOCAL_MODE_BITS);
if (fd == -1) {
return fd;
}
credp->fc_mode = credp->fc_mode|S_IFREG;
/* Set cleint credentials in xattr */
err = local_set_xattr(rpath(fs_ctx, path), credp);
if (err == -1) {
serrno = errno;
goto err_end;
}
} else if (fs_ctx->fs_sm == SM_PASSTHROUGH) {
fd = open(rpath(fs_ctx, path), flags, credp->fc_mode);
if (fd == -1) {
return fd;
}
err = local_post_create_passthrough(fs_ctx, path, credp);
if (err == -1) {
serrno = errno;
goto err_end;
}
}
return fd;
err_end:
close(fd);
remove(rpath(fs_ctx, path));
errno = serrno;
return err;
}
static int local_symlink(FsContext *ctx, const char *oldpath,
const char *newpath)
{
return symlink(oldpath, rpath(ctx, newpath));
}
static int local_link(FsContext *ctx, const char *oldpath, const char *newpath)
{
char *tmp = qemu_strdup(rpath(ctx, oldpath));
int err, serrno = 0;
if (tmp == NULL) {
return -ENOMEM;
}
err = link(tmp, rpath(ctx, newpath));
if (err == -1) {
serrno = errno;
}
qemu_free(tmp);
if (err == -1) {
errno = serrno;
}
return err;
}
static int local_truncate(FsContext *ctx, const char *path, off_t size)
{
return truncate(rpath(ctx, path), size);
}
static int local_rename(FsContext *ctx, const char *oldpath,
const char *newpath)
{
char *tmp;
int err;
tmp = qemu_strdup(rpath(ctx, oldpath));
if (tmp == NULL) {
return -1;
}
err = rename(tmp, rpath(ctx, newpath));
if (err == -1) {
int serrno = errno;
qemu_free(tmp);
errno = serrno;
} else {
qemu_free(tmp);
}
return err;
}
static int local_chown(FsContext *fs_ctx, const char *path, FsCred *credp)
{
if (fs_ctx->fs_sm == SM_MAPPED) {
return local_set_xattr(rpath(fs_ctx, path), credp);
} else if (fs_ctx->fs_sm == SM_PASSTHROUGH) {
return lchown(rpath(fs_ctx, path), credp->fc_uid, credp->fc_gid);
}
return -1;
}
static int local_utime(FsContext *ctx, const char *path,
const struct utimbuf *buf)
{
return utime(rpath(ctx, path), buf);
}
static int local_remove(FsContext *ctx, const char *path)
{
return remove(rpath(ctx, path));
}
static int local_fsync(FsContext *ctx, int fd)
{
return fsync(fd);
}
FileOperations local_ops = {
.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 = local_readdir,
.seekdir = local_seekdir,
.readv = local_readv,
.lseek = local_lseek,
.writev = local_writev,
.chmod = local_chmod,
.mknod = local_mknod,
.mksock = local_mksock,
.mkdir = local_mkdir,
.fstat = local_fstat,
.open2 = local_open2,
.symlink = local_symlink,
.link = local_link,
.truncate = local_truncate,
.rename = local_rename,
.chown = local_chown,
.utime = local_utime,
.remove = local_remove,
.fsync = local_fsync,
};