633 lines
16 KiB
C
633 lines
16 KiB
C
/*
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* Virtio 9p Posix callback
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*
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* Copyright IBM, Corp. 2010
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*
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* Authors:
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* Anthony Liguori <aliguori@us.ibm.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*
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*/
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#include "virtio.h"
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#include "virtio-9p.h"
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#include <arpa/inet.h>
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#include <pwd.h>
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#include <grp.h>
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#include <sys/socket.h>
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#include <sys/un.h>
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#include <attr/xattr.h>
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static const char *rpath(FsContext *ctx, const char *path)
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{
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/* FIXME: so wrong... */
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static char buffer[4096];
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snprintf(buffer, sizeof(buffer), "%s/%s", ctx->fs_root, path);
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return buffer;
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}
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static int local_lstat(FsContext *fs_ctx, const char *path, struct stat *stbuf)
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{
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int err;
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err = lstat(rpath(fs_ctx, path), stbuf);
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if (err) {
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return err;
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}
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if (fs_ctx->fs_sm == SM_MAPPED) {
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/* Actual credentials are part of extended attrs */
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uid_t tmp_uid;
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gid_t tmp_gid;
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mode_t tmp_mode;
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dev_t tmp_dev;
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if (getxattr(rpath(fs_ctx, path), "user.virtfs.uid", &tmp_uid,
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sizeof(uid_t)) > 0) {
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stbuf->st_uid = tmp_uid;
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}
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if (getxattr(rpath(fs_ctx, path), "user.virtfs.gid", &tmp_gid,
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sizeof(gid_t)) > 0) {
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stbuf->st_gid = tmp_gid;
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}
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if (getxattr(rpath(fs_ctx, path), "user.virtfs.mode", &tmp_mode,
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sizeof(mode_t)) > 0) {
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stbuf->st_mode = tmp_mode;
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}
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if (getxattr(rpath(fs_ctx, path), "user.virtfs.rdev", &tmp_dev,
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sizeof(dev_t)) > 0) {
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stbuf->st_rdev = tmp_dev;
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}
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}
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return err;
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}
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static int local_set_xattr(const char *path, FsCred *credp)
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{
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int err;
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if (credp->fc_uid != -1) {
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err = setxattr(path, "user.virtfs.uid", &credp->fc_uid, sizeof(uid_t),
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0);
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if (err) {
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return err;
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}
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}
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if (credp->fc_gid != -1) {
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err = setxattr(path, "user.virtfs.gid", &credp->fc_gid, sizeof(gid_t),
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0);
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if (err) {
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return err;
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}
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}
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if (credp->fc_mode != -1) {
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err = setxattr(path, "user.virtfs.mode", &credp->fc_mode,
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sizeof(mode_t), 0);
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if (err) {
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return err;
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}
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}
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if (credp->fc_rdev != -1) {
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err = setxattr(path, "user.virtfs.rdev", &credp->fc_rdev,
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sizeof(dev_t), 0);
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if (err) {
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return err;
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}
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}
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return 0;
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}
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static int local_post_create_passthrough(FsContext *fs_ctx, const char *path,
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FsCred *credp)
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{
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if (chmod(rpath(fs_ctx, path), credp->fc_mode & 07777) < 0) {
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return -1;
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}
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if (lchown(rpath(fs_ctx, path), credp->fc_uid, credp->fc_gid) < 0) {
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/*
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* If we fail to change ownership and if we are
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* using security model none. Ignore the error
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*/
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if (fs_ctx->fs_sm != SM_NONE) {
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return -1;
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}
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}
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return 0;
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}
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static ssize_t local_readlink(FsContext *fs_ctx, const char *path,
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char *buf, size_t bufsz)
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{
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ssize_t tsize = -1;
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if (fs_ctx->fs_sm == SM_MAPPED) {
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int fd;
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fd = open(rpath(fs_ctx, path), O_RDONLY);
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if (fd == -1) {
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return -1;
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}
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do {
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tsize = read(fd, (void *)buf, bufsz);
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} while (tsize == -1 && errno == EINTR);
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close(fd);
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return tsize;
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} else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
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(fs_ctx->fs_sm == SM_NONE)) {
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tsize = readlink(rpath(fs_ctx, path), buf, bufsz);
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}
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return tsize;
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}
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static int local_close(FsContext *ctx, int fd)
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{
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return close(fd);
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}
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static int local_closedir(FsContext *ctx, DIR *dir)
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{
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return closedir(dir);
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}
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static int local_open(FsContext *ctx, const char *path, int flags)
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{
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return open(rpath(ctx, path), flags);
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}
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static DIR *local_opendir(FsContext *ctx, const char *path)
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{
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return opendir(rpath(ctx, path));
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}
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static void local_rewinddir(FsContext *ctx, DIR *dir)
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{
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return rewinddir(dir);
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}
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static off_t local_telldir(FsContext *ctx, DIR *dir)
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{
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return telldir(dir);
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}
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static struct dirent *local_readdir(FsContext *ctx, DIR *dir)
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{
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return readdir(dir);
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}
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static void local_seekdir(FsContext *ctx, DIR *dir, off_t off)
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{
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return seekdir(dir, off);
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}
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static ssize_t local_readv(FsContext *ctx, int fd, const struct iovec *iov,
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int iovcnt)
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{
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return readv(fd, iov, iovcnt);
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}
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static off_t local_lseek(FsContext *ctx, int fd, off_t offset, int whence)
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{
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return lseek(fd, offset, whence);
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}
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static ssize_t local_writev(FsContext *ctx, int fd, const struct iovec *iov,
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int iovcnt)
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{
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return writev(fd, iov, iovcnt);
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}
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static int local_chmod(FsContext *fs_ctx, const char *path, FsCred *credp)
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{
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if (fs_ctx->fs_sm == SM_MAPPED) {
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return local_set_xattr(rpath(fs_ctx, path), credp);
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} else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
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(fs_ctx->fs_sm == SM_NONE)) {
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return chmod(rpath(fs_ctx, path), credp->fc_mode);
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}
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return -1;
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}
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static int local_mknod(FsContext *fs_ctx, const char *path, FsCred *credp)
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{
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int err = -1;
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int serrno = 0;
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/* Determine the security model */
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if (fs_ctx->fs_sm == SM_MAPPED) {
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err = mknod(rpath(fs_ctx, path), SM_LOCAL_MODE_BITS|S_IFREG, 0);
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if (err == -1) {
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return err;
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}
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local_set_xattr(rpath(fs_ctx, path), credp);
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if (err == -1) {
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serrno = errno;
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goto err_end;
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}
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} else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
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(fs_ctx->fs_sm == SM_NONE)) {
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err = mknod(rpath(fs_ctx, path), credp->fc_mode, credp->fc_rdev);
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if (err == -1) {
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return err;
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}
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err = local_post_create_passthrough(fs_ctx, path, credp);
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if (err == -1) {
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serrno = errno;
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goto err_end;
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}
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}
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return err;
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err_end:
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remove(rpath(fs_ctx, path));
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errno = serrno;
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return err;
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}
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static int local_mkdir(FsContext *fs_ctx, const char *path, FsCred *credp)
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{
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int err = -1;
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int serrno = 0;
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/* Determine the security model */
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if (fs_ctx->fs_sm == SM_MAPPED) {
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err = mkdir(rpath(fs_ctx, path), SM_LOCAL_DIR_MODE_BITS);
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if (err == -1) {
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return err;
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}
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credp->fc_mode = credp->fc_mode|S_IFDIR;
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err = local_set_xattr(rpath(fs_ctx, path), credp);
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if (err == -1) {
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serrno = errno;
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goto err_end;
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}
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} else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
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(fs_ctx->fs_sm == SM_NONE)) {
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err = mkdir(rpath(fs_ctx, path), credp->fc_mode);
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if (err == -1) {
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return err;
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}
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err = local_post_create_passthrough(fs_ctx, path, credp);
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if (err == -1) {
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serrno = errno;
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goto err_end;
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}
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}
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return err;
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err_end:
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remove(rpath(fs_ctx, path));
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errno = serrno;
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return err;
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}
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static int local_fstat(FsContext *fs_ctx, int fd, struct stat *stbuf)
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{
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int err;
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err = fstat(fd, stbuf);
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if (err) {
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return err;
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}
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if (fs_ctx->fs_sm == SM_MAPPED) {
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/* Actual credentials are part of extended attrs */
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uid_t tmp_uid;
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gid_t tmp_gid;
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mode_t tmp_mode;
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dev_t tmp_dev;
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if (fgetxattr(fd, "user.virtfs.uid", &tmp_uid, sizeof(uid_t)) > 0) {
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stbuf->st_uid = tmp_uid;
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}
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if (fgetxattr(fd, "user.virtfs.gid", &tmp_gid, sizeof(gid_t)) > 0) {
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stbuf->st_gid = tmp_gid;
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}
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if (fgetxattr(fd, "user.virtfs.mode", &tmp_mode, sizeof(mode_t)) > 0) {
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stbuf->st_mode = tmp_mode;
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}
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if (fgetxattr(fd, "user.virtfs.rdev", &tmp_dev, sizeof(dev_t)) > 0) {
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stbuf->st_rdev = tmp_dev;
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}
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}
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return err;
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}
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static int local_open2(FsContext *fs_ctx, const char *path, int flags,
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FsCred *credp)
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{
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int fd = -1;
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int err = -1;
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int serrno = 0;
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/* Determine the security model */
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if (fs_ctx->fs_sm == SM_MAPPED) {
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fd = open(rpath(fs_ctx, path), flags, SM_LOCAL_MODE_BITS);
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if (fd == -1) {
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return fd;
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}
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credp->fc_mode = credp->fc_mode|S_IFREG;
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/* Set cleint credentials in xattr */
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err = local_set_xattr(rpath(fs_ctx, path), credp);
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if (err == -1) {
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serrno = errno;
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goto err_end;
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}
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} else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
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(fs_ctx->fs_sm == SM_NONE)) {
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fd = open(rpath(fs_ctx, path), flags, credp->fc_mode);
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if (fd == -1) {
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return fd;
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}
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err = local_post_create_passthrough(fs_ctx, path, credp);
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if (err == -1) {
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serrno = errno;
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goto err_end;
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}
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}
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return fd;
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err_end:
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close(fd);
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remove(rpath(fs_ctx, path));
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errno = serrno;
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return err;
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}
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static int local_symlink(FsContext *fs_ctx, const char *oldpath,
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const char *newpath, FsCred *credp)
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{
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int err = -1;
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int serrno = 0;
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/* Determine the security model */
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if (fs_ctx->fs_sm == SM_MAPPED) {
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int fd;
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ssize_t oldpath_size, write_size;
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fd = open(rpath(fs_ctx, newpath), O_CREAT|O_EXCL|O_RDWR,
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SM_LOCAL_MODE_BITS);
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if (fd == -1) {
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return fd;
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}
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/* Write the oldpath (target) to the file. */
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oldpath_size = strlen(oldpath) + 1;
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do {
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write_size = write(fd, (void *)oldpath, oldpath_size);
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} while (write_size == -1 && errno == EINTR);
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if (write_size != oldpath_size) {
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serrno = errno;
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close(fd);
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err = -1;
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goto err_end;
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}
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close(fd);
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/* Set cleint credentials in symlink's xattr */
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credp->fc_mode = credp->fc_mode|S_IFLNK;
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err = local_set_xattr(rpath(fs_ctx, newpath), credp);
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if (err == -1) {
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serrno = errno;
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goto err_end;
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}
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} else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
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(fs_ctx->fs_sm == SM_NONE)) {
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err = symlink(oldpath, rpath(fs_ctx, newpath));
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if (err) {
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return err;
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}
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err = lchown(rpath(fs_ctx, newpath), credp->fc_uid, credp->fc_gid);
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if (err == -1) {
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/*
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* If we fail to change ownership and if we are
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* using security model none. Ignore the error
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*/
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if (fs_ctx->fs_sm != SM_NONE) {
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serrno = errno;
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goto err_end;
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} else
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err = 0;
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}
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}
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return err;
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err_end:
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remove(rpath(fs_ctx, newpath));
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errno = serrno;
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return err;
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}
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static int local_link(FsContext *ctx, const char *oldpath, const char *newpath)
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{
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char *tmp = qemu_strdup(rpath(ctx, oldpath));
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int err, serrno = 0;
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if (tmp == NULL) {
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return -ENOMEM;
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}
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err = link(tmp, rpath(ctx, newpath));
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if (err == -1) {
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serrno = errno;
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}
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qemu_free(tmp);
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if (err == -1) {
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errno = serrno;
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}
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return err;
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}
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static int local_truncate(FsContext *ctx, const char *path, off_t size)
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{
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return truncate(rpath(ctx, path), size);
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}
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static int local_rename(FsContext *ctx, const char *oldpath,
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const char *newpath)
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{
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char *tmp;
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int err;
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tmp = qemu_strdup(rpath(ctx, oldpath));
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err = rename(tmp, rpath(ctx, newpath));
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if (err == -1) {
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int serrno = errno;
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qemu_free(tmp);
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errno = serrno;
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} else {
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qemu_free(tmp);
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}
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return err;
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}
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static int local_chown(FsContext *fs_ctx, const char *path, FsCred *credp)
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{
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if ((credp->fc_uid == -1 && credp->fc_gid == -1) ||
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(fs_ctx->fs_sm == SM_PASSTHROUGH)) {
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return lchown(rpath(fs_ctx, path), credp->fc_uid, credp->fc_gid);
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} else if (fs_ctx->fs_sm == SM_MAPPED) {
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return local_set_xattr(rpath(fs_ctx, path), credp);
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} else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
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(fs_ctx->fs_sm == SM_NONE)) {
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return lchown(rpath(fs_ctx, path), credp->fc_uid, credp->fc_gid);
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}
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return -1;
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}
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static int local_utimensat(FsContext *s, const char *path,
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const struct timespec *buf)
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{
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return utimensat(AT_FDCWD, rpath(s, path), buf, AT_SYMLINK_NOFOLLOW);
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}
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static int local_remove(FsContext *ctx, const char *path)
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{
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return remove(rpath(ctx, path));
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}
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static int local_fsync(FsContext *ctx, int fd)
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{
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return fsync(fd);
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}
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static int local_statfs(FsContext *s, const char *path, struct statfs *stbuf)
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{
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return statfs(rpath(s, path), stbuf);
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}
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static ssize_t local_lgetxattr(FsContext *ctx, const char *path,
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const char *name, void *value, size_t size)
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{
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if ((ctx->fs_sm == SM_MAPPED) &&
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(strncmp(name, "user.virtfs.", 12) == 0)) {
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/*
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* Don't allow fetch of user.virtfs namesapce
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* in case of mapped security
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*/
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errno = ENOATTR;
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return -1;
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}
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return lgetxattr(rpath(ctx, path), name, value, size);
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}
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static ssize_t local_llistxattr(FsContext *ctx, const char *path,
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void *value, size_t size)
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{
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ssize_t retval;
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ssize_t actual_len = 0;
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char *orig_value, *orig_value_start;
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char *temp_value, *temp_value_start;
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ssize_t xattr_len, parsed_len = 0, attr_len;
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|
if (ctx->fs_sm != SM_MAPPED) {
|
|
return llistxattr(rpath(ctx, path), value, size);
|
|
}
|
|
|
|
/* Get the actual len */
|
|
xattr_len = llistxattr(rpath(ctx, path), value, 0);
|
|
|
|
/* Now fetch the xattr and find the actual size */
|
|
orig_value = qemu_malloc(xattr_len);
|
|
xattr_len = llistxattr(rpath(ctx, path), orig_value, xattr_len);
|
|
|
|
/*
|
|
* For mapped security model drop user.virtfs namespace
|
|
* from the list
|
|
*/
|
|
temp_value = qemu_mallocz(xattr_len);
|
|
temp_value_start = temp_value;
|
|
orig_value_start = orig_value;
|
|
while (xattr_len > parsed_len) {
|
|
attr_len = strlen(orig_value) + 1;
|
|
if (strncmp(orig_value, "user.virtfs.", 12) != 0) {
|
|
/* Copy this entry */
|
|
strcat(temp_value, orig_value);
|
|
temp_value += attr_len;
|
|
actual_len += attr_len;
|
|
}
|
|
parsed_len += attr_len;
|
|
orig_value += attr_len;
|
|
}
|
|
if (!size) {
|
|
retval = actual_len;
|
|
goto out;
|
|
} else if (size >= actual_len) {
|
|
/* now copy the parsed attribute list back */
|
|
memset(value, 0, size);
|
|
memcpy(value, temp_value_start, actual_len);
|
|
retval = actual_len;
|
|
goto out;
|
|
}
|
|
errno = ERANGE;
|
|
retval = -1;
|
|
out:
|
|
qemu_free(orig_value_start);
|
|
qemu_free(temp_value_start);
|
|
return retval;
|
|
}
|
|
|
|
static int local_lsetxattr(FsContext *ctx, const char *path, const char *name,
|
|
void *value, size_t size, int flags)
|
|
{
|
|
if ((ctx->fs_sm == SM_MAPPED) &&
|
|
(strncmp(name, "user.virtfs.", 12) == 0)) {
|
|
/*
|
|
* Don't allow fetch of user.virtfs namesapce
|
|
* in case of mapped security
|
|
*/
|
|
errno = EACCES;
|
|
return -1;
|
|
}
|
|
return lsetxattr(rpath(ctx, path), name, value, size, flags);
|
|
}
|
|
|
|
static int local_lremovexattr(FsContext *ctx,
|
|
const char *path, const char *name)
|
|
{
|
|
if ((ctx->fs_sm == SM_MAPPED) &&
|
|
(strncmp(name, "user.virtfs.", 12) == 0)) {
|
|
/*
|
|
* Don't allow fetch of user.virtfs namesapce
|
|
* in case of mapped security
|
|
*/
|
|
errno = EACCES;
|
|
return -1;
|
|
}
|
|
return lremovexattr(rpath(ctx, path), name);
|
|
}
|
|
|
|
|
|
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,
|
|
.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,
|
|
};
|