[Libguestfs] [PATCH 2/7] New internal API: internal_set_libvirt_selinux_label

[Matthew Booth]

On Thu, 2013-02-28 at 10:57 +0000, Richard W.M. Jones wrote:
> From: "Richard W.M. Jones" <rjones at redhat.com>
> 
> This internal API sets two SELinux labels in the handle (the process
> label and the image label -- they are closely related).
> 
> If using the libvirt attach-method with SELinux and sVirt, then this
> will cause the following XML to be added to the appliance definition:
> 
> <seclabel type=static model=selinux relabel=yes>
>   <label>[LABEL HERE]</label>
>   <imagelabel>[IMAGELABEL HERE]</imagelabel>
> </seclabel>

We're hard-coding type=static, model=selinux, relabel=yes here. I have
no idea what the implications of this are. Are we sure this is ok? I
guess Dan would be the person to ask.

> It is ignored by other attach-methods.
> ---
>  generator/actions.ml   | 12 ++++++++++++
>  src/guestfs-internal.h |  2 ++
>  src/handle.c           |  2 ++
>  src/launch-libvirt.c   | 36 ++++++++++++++++++++++++++++++++++++
>  4 files changed, 52 insertions(+)
> 
> diff --git a/generator/actions.ml b/generator/actions.ml
> index 8a8e3ff..59e667d 100644
> --- a/generator/actions.ml
> +++ b/generator/actions.ml
> @@ -2694,6 +2694,18 @@ the default.  Else C</var/tmp> is the default." };
>      longdesc = "\
>  Get the directory used by the handle to store the appliance cache." };
>  
> +  { defaults with
> +    name = "internal_set_libvirt_selinux_label";
> +    style = RErr, [String "label"; String "imagelabel"], [];
> +    blocking = false;
> +    visibility = VInternal;
> +    shortdesc = "set SELinux label used by the libvirt attach method";
> +    longdesc = "\
> +This internal function sets the SELinux security label (in
> +reality, two labels: the process label and the image label)
> +used by the appliance when the libvirt attach method is selected
> +(it is ignored by other attach methods)." };
> +
>  ]
>  
>  (* daemon_functions are any functions which cause some action
> diff --git a/src/guestfs-internal.h b/src/guestfs-internal.h
> index e1a7d31..78e2bf5 100644
> --- a/src/guestfs-internal.h
> +++ b/src/guestfs-internal.h
> @@ -322,6 +322,8 @@ struct guestfs_h
>      virDomainPtr dom;           /* libvirt domain */
>    } virt;
>  #endif
> +  char *virt_selinux_label;
> +  char *virt_selinux_imagelabel;
>  };
>  
>  /* Per-filesystem data stored for inspect_os. */
> diff --git a/src/handle.c b/src/handle.c
> index c630daf..2f44632 100644
> --- a/src/handle.c
> +++ b/src/handle.c
> @@ -326,6 +326,8 @@ guestfs_close (guestfs_h *g)
>  
>    if (g->pda)
>      hash_free (g->pda);
> +  free (g->virt_selinux_label);
> +  free (g->virt_selinux_imagelabel);
>    free (g->tmpdir);
>    free (g->env_tmpdir);
>    free (g->int_tmpdir);
> diff --git a/src/launch-libvirt.c b/src/launch-libvirt.c
> index 7db2ce5..0a59cb6 100644
> --- a/src/launch-libvirt.c
> +++ b/src/launch-libvirt.c
> @@ -855,6 +855,31 @@ construct_libvirt_xml_seclabel (guestfs_h *g,
>                                             BAD_CAST "none"));
>      XMLERROR (-1, xmlTextWriterEndElement (xo));
>    }
> +  else if (g->virt_selinux_label) {
> +    /* Enable sVirt and pass a custom <seclabel/> inherited from the
> +     * original libvirt domain (when guestfs_add_domain was called).
> +     * https://bugzilla.redhat.com/show_bug.cgi?id=912499#c7
> +     */
> +    XMLERROR (-1, xmlTextWriterStartElement (xo, BAD_CAST "seclabel"));
> +    XMLERROR (-1,
> +              xmlTextWriterWriteAttribute (xo, BAD_CAST "type",
> +                                           BAD_CAST "static"));
> +    XMLERROR (-1,
> +              xmlTextWriterWriteAttribute (xo, BAD_CAST "model",
> +                                           BAD_CAST "selinux"));
> +    XMLERROR (-1,
> +              xmlTextWriterWriteAttribute (xo, BAD_CAST "relabel",
> +                                           BAD_CAST "yes"));
> +    XMLERROR (-1, xmlTextWriterStartElement (xo, BAD_CAST "label"));
> +    XMLERROR (-1, xmlTextWriterWriteString (xo,
> +                                            BAD_CAST g->virt_selinux_label));
> +    XMLERROR (-1, xmlTextWriterEndElement (xo));
> +    XMLERROR (-1, xmlTextWriterStartElement (xo, BAD_CAST "imagelabel"));
> +    XMLERROR (-1, xmlTextWriterWriteString (xo,
> +                                            BAD_CAST g->virt_selinux_imagelabel));
> +    XMLERROR (-1, xmlTextWriterEndElement (xo));
> +    XMLERROR (-1, xmlTextWriterEndElement (xo));
> +  }
>  
>    return 0;
>  }
> @@ -1603,3 +1628,14 @@ struct attach_ops attach_ops_libvirt = {
>  };
>  
>  #endif /* no libvirt or libxml2 at compile time */
> +
> +int
> +guestfs__internal_set_libvirt_selinux_label (guestfs_h *g, const char *label,
> +                                             const char *imagelabel)
> +{
> +  free (g->virt_selinux_label);
> +  g->virt_selinux_label = safe_strdup (g, label);
> +  free (g->virt_selinux_imagelabel);
> +  g->virt_selinux_imagelabel = safe_strdup (g, imagelabel);
> +  return 0;
> +}

Assuming the hard-coding is acceptable, ACK.

Matt