From fe36f57d5f5c19d17c29e04c68526eb4b0118db6 Mon Sep 17 00:00:00 2001

From: "Richard W.M. Jones" <rjones@redhat.com>

Date: Tue, 5 May 2015 15:55:53 +0100

Subject: [PATCH] v2v: Add a C function to fetch libvirt hypervisor

 capabilities.

Instead of having to run external 'virsh capabilities' command and

parsing the output.

(cherry picked from commit e7833a5eea350ca3579d1f9e6702e116b45572fc)

---

 v2v/domainxml-c.c     | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++-

 v2v/domainxml.ml      |  5 +++-

 v2v/domainxml.mli     |  7 +++++-

 v2v/output_libvirt.ml |  9 +-------

 4 files changed, 74 insertions(+), 11 deletions(-)

diff --git a/v2v/domainxml-c.c b/v2v/domainxml-c.c

index 60157e1..2aebc5c 100644

--- a/v2v/domainxml-c.c

+++ b/v2v/domainxml-c.c

@@ -16,7 +16,9 @@

  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

  */

-/* [virsh dumpxml] but with non-broken authentication handling. */

+/* This module implements various [virsh]-like commands, but with

+ * non-broken authentication handling.

+ */

 #include <config.h>

@@ -360,6 +362,60 @@ v2v_vol_dumpxml (value connv, value poolnamev, value volnamev)

   CAMLreturn (retv);

 }

+value

+v2v_capabilities (value connv, value unitv)

+{

+  CAMLparam2 (connv, unitv);

+  CAMLlocal1 (capabilitiesv);

+  const char *conn_uri = NULL;

+  char *capabilities;

+  /* We have to assemble the error on the stack because a dynamic

+   * string couldn't be freed.

+   */

+  char errmsg[256];

+  virErrorPtr err;

+  virConnectPtr conn;

+

+  if (connv != Val_int (0))

+    conn_uri = String_val (Field (connv, 0)); /* Some conn */

+

+  /* We have to call the default authentication handler, not least

+   * since it handles all the PolicyKit crap.  However it also makes

+   * coding this simpler.

+   */

+  conn = virConnectOpenAuth (conn_uri, virConnectAuthPtrDefault,

+                             VIR_CONNECT_RO);

+  if (conn == NULL) {

+    if (conn_uri)

+      snprintf (errmsg, sizeof errmsg,

+                _("cannot open libvirt connection '%s'"), conn_uri);

+    else

+      snprintf (errmsg, sizeof errmsg, _("cannot open libvirt connection"));

+    caml_invalid_argument (errmsg);

+  }

+

+  /* Suppress default behaviour of printing errors to stderr.  Note

+   * you can't set this to NULL to ignore errors; setting it to NULL

+   * restores the default error handler ...

+   */

+  virConnSetErrorFunc (conn, NULL, ignore_errors);

+

+  capabilities = virConnectGetCapabilities (conn);

+  if (!capabilities) {

+    err = virGetLastError ();

+    snprintf (errmsg, sizeof errmsg,

+              _("cannot get libvirt hypervisor capabilities: %s"),

+              err->message);

+    virConnectClose (conn);

+    caml_invalid_argument (errmsg);

+  }

+

+  capabilitiesv = caml_copy_string (capabilities);

+  free (capabilities);

+

+  CAMLreturn (capabilitiesv);

+}

+

 #else /* !HAVE_LIBVIRT */

 value

@@ -380,4 +436,10 @@ v2v_vol_dumpxml (value connv, value poolnamev, value volnamev)

   caml_invalid_argument ("virt-v2v was compiled without libvirt support");

 }

+value

+v2v_capabilities (value connv, value unitv)

+{

+  caml_invalid_argument ("virt-v2v was compiled without libvirt support");

+}

+

 #endif /* !HAVE_LIBVIRT */

diff --git a/v2v/domainxml.ml b/v2v/domainxml.ml

index d8b9ed4..3357856 100644

--- a/v2v/domainxml.ml

+++ b/v2v/domainxml.ml

@@ -16,8 +16,11 @@

  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

  *)

-(* [virsh dumpxml] but with non-broken authentication handling. *)

+(* This module implements various [virsh]-like commands, but with

+    non-broken authentication handling. *)

 external dumpxml : ?password:string -> ?conn:string -> string -> string = "v2v_dumpxml"

 external pool_dumpxml : ?conn:string -> string -> string = "v2v_pool_dumpxml"

 external vol_dumpxml : ?conn:string -> string -> string -> string = "v2v_vol_dumpxml"

+

+external capabilities : ?conn:string -> unit -> string = "v2v_capabilities"

diff --git a/v2v/domainxml.mli b/v2v/domainxml.mli

index 98690fe..089b793 100644

--- a/v2v/domainxml.mli

+++ b/v2v/domainxml.mli

@@ -16,7 +16,8 @@

  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

  *)

-(** [virsh dumpxml] but with non-broken authentication handling.

+(** This module implements various [virsh]-like commands, but with

+    non-broken authentication handling.

     If you do [virsh dumpxml foo] and if the libvirt source (eg. ESX)

     requires an interactive password, then virsh unhelpfully sends the

@@ -38,3 +39,7 @@ val vol_dumpxml : ?conn:string -> string -> string -> string

     which is part of the pool [pool].

     The optional [?conn] parameter is the libvirt connection URI.

     [pool] may be a pool name or UUID. *)

+

+val capabilities : ?conn:string -> unit -> string

+(** [capabilities ?conn ()] returns the libvirt capabilities XML.

+    The optional [?conn] parameter is the libvirt connection URI. *)

diff --git a/v2v/output_libvirt.ml b/v2v/output_libvirt.ml

index 48d39e2..b516d51 100644

--- a/v2v/output_libvirt.ml

+++ b/v2v/output_libvirt.ml

@@ -325,14 +325,7 @@ class output_libvirt verbose oc output_pool = object

   method prepare_targets source targets =

     (* Get the capabilities from libvirt. *)

-    let cmd =

-      match oc with

-      | None -> "virsh capabilities"

-      | Some uri -> sprintf "virsh -c %s capabilities" (quote uri) in

-    if verbose then printf "%s\n%!" cmd;

-    let xml = external_command ~prog cmd in

-    let xml = String.concat "\n" xml in

-

+    let xml = Domainxml.capabilities ?conn:oc () in

     if verbose then printf "libvirt capabilities XML:\n%s\n%!" xml;

     (* This just checks that the capabilities XML is well-formed,

-- 

1.8.3.1