Re: [Qemu-devel] [V3 PATCH 5/8] virtio-9p: Create support in chroot environment

[Blue Swirl]

On Tue, Jan 18, 2011 at 6:25 AM, M. Mohan Kumar <address@hidden> wrote:
> Add both server & client side interfaces to create regular files in
> chroot environment
>
> Signed-off-by: M. Mohan Kumar <address@hidden>
> ---
>  hw/9pfs/virtio-9p-chroot.c |   42 ++++++++++++++++++++++++++++++++++++++++++
>  hw/9pfs/virtio-9p-local.c  |   22 ++++++++++++++++++++--
>  2 files changed, 62 insertions(+), 2 deletions(-)
>
> diff --git a/hw/9pfs/virtio-9p-chroot.c b/hw/9pfs/virtio-9p-chroot.c
> index b599e23..e7f85e2 100644
> --- a/hw/9pfs/virtio-9p-chroot.c
> +++ b/hw/9pfs/virtio-9p-chroot.c
> @@ -193,6 +193,42 @@ static void chroot_do_open(V9fsFileObjectRequest 
> *request, FdInfo *fd_info)
>     }
>  }
>
> +/*
> + * Helper routine to create a file and return the file descriptor and
> + * error status in FdInfo structure.
> + */
> +static void chroot_do_create(V9fsFileObjectRequest *request, FdInfo *fd_info)
> +{
> +    int cur_uid, cur_gid;

uid_t cur_uid;
gid_t cur_gid;

> +
> +    cur_uid = geteuid();
> +    cur_gid = getegid();
> +
> +    fd_info->fi_fd = -1;
> +
> +    if (setfsuid(request->data.uid) < 0) {
> +        fd_info->fi_error = errno;
> +        return;
> +    }
> +    if (setfsgid(request->data.gid) < 0) {
> +        fd_info->fi_error = errno;
> +        goto unset_uid;
> +    }
> +
> +    fd_info->fi_fd = open(request->path.path, request->data.flags,
> +                        request->data.mode);
> +
> +    if (fd_info->fi_fd < 0) {
> +        fd_info->fi_error = errno;
> +    } else {
> +        fd_info->fi_error = 0;
> +    }
> +
> +    setfsgid(cur_gid);
> +unset_uid:
> +    setfsuid(cur_uid);
> +}
> +
>  static int chroot_daemonize(int chroot_sock)
>  {
>     sigset_t sigset;
> @@ -276,6 +312,12 @@ int v9fs_chroot(FsContext *fs_ctx)
>                 error = -2;
>             }
>             break;
> +        case T_CREATE:
> +            chroot_do_create(&request, &fd_info);
> +            if (chroot_sendfd(chroot_sock, &fd_info) <= 0) {
> +                error = -2;
> +            }
> +            break;
>         default:
>             break;
>         }
> diff --git a/hw/9pfs/virtio-9p-local.c b/hw/9pfs/virtio-9p-local.c
> index 2376ec2..7f39b40 100644
> --- a/hw/9pfs/virtio-9p-local.c
> +++ b/hw/9pfs/virtio-9p-local.c
> @@ -52,6 +52,23 @@ static int __open(FsContext *fs_ctx, const char *path, int 
> flags)
>     return fd;
>  }
>
> +static int __create(FsContext *fs_ctx, const char *path, int flags,

Please don't use identifiers starting with underscores.