[Libguestfs] [PATCH] daemon: resolve paths for ll and llz

[Richard W.M. Jones]

On Fri, Jan 15, 2016 at 11:33:49AM +0100, Pino Toscano wrote:
> Resolve in the guest the given path, so absolute symlinks can be listed
> using appliance tools without resolution errors.
> Also remove the note about the possibility to escape the sysroot using
> ll and llz, since realpath won't return paths outside sysroot.
> 
> Fixes part of RHBZ#1293276.
> ---
>  daemon/ls.c | 28 ++++++++++++++++++++--------
>  1 file changed, 20 insertions(+), 8 deletions(-)
> 
> diff --git a/daemon/ls.c b/daemon/ls.c
> index d3689cd..0e2f110 100644
> --- a/daemon/ls.c
> +++ b/daemon/ls.c
> @@ -95,21 +95,24 @@ do_ls0 (const char *path)
>    return 0;
>  }
>  
> -/* Because we can't chroot and run the ls command (since 'ls' won't
> - * necessarily exist in the chroot), this command can be used to escape
> - * from the sysroot (eg. 'll /..').  This command is not meant for
> - * serious use anyway, just for quick interactive sessions.
> - */
> -
>  char *
>  do_ll (const char *path)
>  {
>    int r;
>    char *out;
>    CLEANUP_FREE char *err = NULL;
> +  CLEANUP_FREE char *rpath = NULL;
>    CLEANUP_FREE char *spath = NULL;
>  
> -  spath = sysroot_path (path);
> +  CHROOT_IN;
> +  rpath = realpath (path, NULL);
> +  CHROOT_OUT;
> +  if (rpath == NULL) {
> +    reply_with_perror ("%s", path);
> +    return NULL;
> +  }
> +
> +  spath = sysroot_path (rpath);
>    if (!spath) {
>      reply_with_perror ("malloc");
>      return NULL;
> @@ -131,9 +134,18 @@ do_llz (const char *path)
>    int r;
>    char *out;
>    CLEANUP_FREE char *err = NULL;
> +  CLEANUP_FREE char *rpath = NULL;
>    CLEANUP_FREE char *spath = NULL;
>  
> -  spath = sysroot_path (path);
> +  CHROOT_IN;
> +  rpath = realpath (path, NULL);
> +  CHROOT_OUT;
> +  if (rpath == NULL) {
> +    reply_with_perror ("%s", path);
> +    return NULL;
> +  }
> +
> +  spath = sysroot_path (rpath);
>    if (!spath) {
>      reply_with_perror ("malloc");
>      return NULL;

Looks good, ACK.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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