On 2/28/2011 3:22 AM, M. Mohan Kumar wrote:
> Add both chroot deamon and qemu side interfaces to create special files
> (directory, device nodes, links and symbolic links)
>
> Signed-off-by: M. Mohan Kumar <mo...@in.ibm.com>
> ---
> hw/9pfs/virtio-9p-chroot-dm.c | 57 ++++++++++++++++++++++++
> hw/9pfs/virtio-9p-chroot-qemu.c | 19 ++++++++
> hw/9pfs/virtio-9p-chroot.h | 1 +
> hw/9pfs/virtio-9p-local.c | 93
> ++++++++++++++++++++++++++-------------
> 4 files changed, 139 insertions(+), 31 deletions(-)
>
> diff --git a/hw/9pfs/virtio-9p-chroot-dm.c b/hw/9pfs/virtio-9p-chroot-dm.c
> index 985d42b..0ead017 100644
> --- a/hw/9pfs/virtio-9p-chroot-dm.c
> +++ b/hw/9pfs/virtio-9p-chroot-dm.c
> @@ -119,6 +119,57 @@ unset_uid:
> setfsuid(cur_uid);
> }
>
> +/*
> + * Create directory, symbolic link, link, device node and regular files
> + * Similar to create, but it does not return the fd of created object
> + * Returns 0 as file descriptor on success and -errno on failure in FdInfo
> + * structure
> + */
> +static void chroot_do_create_special(V9fsFileObjectRequest *request,
> + FdInfo *fd_info)
> +{
> + int cur_uid, cur_gid;
> +
> + cur_uid = geteuid();
> + cur_gid = getegid();
> +
> + fd_info->fi_fd = -1;
> + /* fd is not valid for create operations */
> + fd_info->fi_flags = FI_FD_INVALID;
> +
> + if (setfsuid(request->data.uid) < 0) {
> + fd_info->fi_fd = -errno;
> + return;
> + }
> + if (setfsgid(request->data.gid) < 0) {
> + fd_info->fi_fd = -errno;
> + goto unset_uid;
> + }
> +
> + switch (request->data.type) {
> + case T_MKDIR:
> + fd_info->fi_fd = mkdir(request->path.path, request->data.mode);
> + break;
> + case T_SYMLINK:
> + fd_info->fi_fd = symlink(request->path.old_path, request->path.path);
> + break;
> + case T_LINK:
> + fd_info->fi_fd = link(request->path.old_path, request->path.path);
> + break;
> + default:
> + fd_info->fi_fd = mknod(request->path.path, request->data.mode,
> + request->data.dev);
> + break;
> + }
> +
> + if (fd_info->fi_fd < 0) {
> + fd_info->fi_fd = -errno;
> + }
> + setfsgid(cur_gid);
> +unset_uid:
> + setfsuid(cur_uid);
> +}
> +
> static int chroot_daemonize(int chroot_sock)
> {
> sigset_t sigset;
> @@ -216,6 +267,12 @@ int v9fs_chroot(FsContext *fs_ctx)
> case T_CREATE:
> chroot_do_create(&request, &fd_info);
> break;
> + case T_MKDIR:
> + case T_SYMLINK:
> + case T_LINK:
> + case T_MKNOD:
> + chroot_do_create_special(&request, &fd_info);
> + break;
> default:
> fd_info.fi_flags = FI_FD_SOCKERR;
> break;
> diff --git a/hw/9pfs/virtio-9p-chroot-qemu.c b/hw/9pfs/virtio-9p-chroot-qemu.c
> index 41f9db2..1a42dc2 100644
> --- a/hw/9pfs/virtio-9p-chroot-qemu.c
> +++ b/hw/9pfs/virtio-9p-chroot-qemu.c
> @@ -103,3 +103,22 @@ unlock:
> qemu_mutex_unlock(&fs_ctx->chroot_mutex);
> return fd;
> }
> +
> +/* Return 0 on success or -errno on error */
> +int v9fs_create_special(FsContext *fs_ctx, V9fsFileObjectRequest *request)
> +{
> + int fd, sock_error;
Since this is not fd; may be you can use some other variable like err or
something?
> + qemu_mutex_lock(&fs_ctx->chroot_mutex);
> + if (fs_ctx->chroot_ioerror) {
> + fd = -EIO;
> + goto unlock;
> + }
> + v9fs_write_request(fs_ctx->chroot_socket, request);
> + fd = v9fs_receivefd(fs_ctx->chroot_socket, &sock_error);
> + if (fd < 0 && sock_error) {
> + fs_ctx->chroot_ioerror = 1;
> + }
Format??
- JV
> +unlock:
> + qemu_mutex_unlock(&fs_ctx->chroot_mutex);
> + return fd;
> +}
> diff --git a/hw/9pfs/virtio-9p-chroot.h b/hw/9pfs/virtio-9p-chroot.h
> index 4592807..f113ff1 100644
> --- a/hw/9pfs/virtio-9p-chroot.h
> +++ b/hw/9pfs/virtio-9p-chroot.h
> @@ -54,5 +54,6 @@ typedef struct V9fsFileObjectRequest
>
> int v9fs_chroot(FsContext *fs_ctx);
> int v9fs_request(FsContext *fs_ctx, V9fsFileObjectRequest *or);
> +int v9fs_create_special(FsContext *fs_ctx, V9fsFileObjectRequest *request);
>
> #endif /* _QEMU_VIRTIO_9P_CHROOT_H */
> diff --git a/hw/9pfs/virtio-9p-local.c b/hw/9pfs/virtio-9p-local.c
> index 3fed16c..c92c5dd 100644
> --- a/hw/9pfs/virtio-9p-local.c
> +++ b/hw/9pfs/virtio-9p-local.c
> @@ -74,6 +74,28 @@ static int passthrough_create(FsContext *fs_ctx, const
> char *path, int flags,
> return fd;
> }
>
> +static int passthrough_create_special(FsContext *fs_ctx, const char *oldpath,
> + const char *path, FsCred *credp, int type)
> +{
> + V9fsFileObjectRequest request;
> + int retval;
> +
> + retval = fill_fileobjectrequest(&request, path, credp);
> + if (retval < 0) {
> + return retval;
> + }
> + request.data.type = type;
> + if (oldpath) {
> + request.data.oldpath_len = strlen(oldpath);
> + if (strlen(oldpath) > PATH_MAX) {
> + return -ENAMETOOLONG;
> + }
> + strcpy(request.path.old_path, oldpath);
> + }
> + retval = v9fs_create_special(fs_ctx, &request);
> + return retval;
> +}
> +
> static int local_lstat(FsContext *fs_ctx, const char *path, struct stat
> *stbuf)
> {
> int err;
> @@ -291,8 +313,7 @@ static int local_mknod(FsContext *fs_ctx, const char
> *path, FsCred *credp)
> serrno = errno;
> goto err_end;
> }
> - } else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
> - (fs_ctx->fs_sm == SM_NONE)) {
> + } else if (fs_ctx->fs_sm == SM_NONE) {
> err = mknod(rpath(fs_ctx, path), credp->fc_mode, credp->fc_rdev);
> if (err == -1) {
> return err;
> @@ -302,6 +323,12 @@ static int local_mknod(FsContext *fs_ctx, const char
> *path, FsCred *credp)
> serrno = errno;
> goto err_end;
> }
> + } else if (fs_ctx->fs_sm == SM_PASSTHROUGH) {
> + err = passthrough_create_special(fs_ctx, NULL, path, credp, T_MKNOD);
> + if (err < 0) {
> + serrno = errno;
> + goto err_end;
> + }
> }
> return err;
>
> @@ -328,8 +355,7 @@ static int local_mkdir(FsContext *fs_ctx, const char
> *path, FsCred *credp)
> serrno = errno;
> goto err_end;
> }
> - } else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
> - (fs_ctx->fs_sm == SM_NONE)) {
> + } else if (fs_ctx->fs_sm == SM_NONE) {
> err = mkdir(rpath(fs_ctx, path), credp->fc_mode);
> if (err == -1) {
> return err;
> @@ -339,6 +365,12 @@ static int local_mkdir(FsContext *fs_ctx, const char
> *path, FsCred *credp)
> serrno = errno;
> goto err_end;
> }
> + } else if (fs_ctx->fs_sm == SM_PASSTHROUGH) {
> + err = passthrough_create_special(fs_ctx, NULL, path, credp, T_MKDIR);
> + if (err < 0) {
> + serrno = errno;
> + goto err_end;
> + }
> }
> return err;
>
> @@ -456,23 +488,19 @@ static int local_symlink(FsContext *fs_ctx, const char
> *oldpath,
> serrno = errno;
> goto err_end;
> }
> - } else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
> - (fs_ctx->fs_sm == SM_NONE)) {
> + } else if (fs_ctx->fs_sm == SM_NONE) {
> err = symlink(oldpath, rpath(fs_ctx, newpath));
> if (err) {
> return err;
> }
> err = lchown(rpath(fs_ctx, newpath), 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;
> + err = 0;
> + } else if (fs_ctx->fs_sm == SM_PASSTHROUGH) {
> + err = passthrough_create_special(fs_ctx, oldpath, newpath, credp,
> + T_SYMLINK);
> + if (err < 0) {
> + serrno = errno;
> + goto err_end;
> }
> }
> return err;
> @@ -483,24 +511,27 @@ err_end:
> return err;
> }
>
> -static int local_link(FsContext *ctx, const char *oldpath, const char
> *newpath)
> +static int local_link(FsContext *fs_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;
> + if (fs_ctx->fs_sm == SM_PASSTHROUGH) {
> + err = passthrough_create_special(fs_ctx, oldpath, newpath, NULL,
> + T_LINK);
> + if (err < 0) {
> + serrno = errno;
> + }
> + } else {
> + char *tmp = qemu_strdup(rpath(fs_ctx, oldpath));
> + if (tmp == NULL) {
> + return -ENOMEM;
> + }
> + err = link(tmp, rpath(fs_ctx, newpath));
> + if (err == -1) {
> + serrno = errno;
> + }
> + qemu_free(tmp);
> }
>
> return err;
