libguestfs/SOURCES/0059-Revert-launch-libvirt-Use-qemu-bridge-helper-to-impl.patch

From 66a40516a2696b7528803d7637c022659fa8c46e Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Thu, 2 Oct 2014 16:44:07 +0100
Subject: [PATCH] Revert "launch: libvirt: Use qemu-bridge-helper to implement
 a full network (RHBZ#1148012)."

We've been carrying this exact patch in RHEL 7 for several years.  It
reverts the change made in 2014 where we switched to using the virbr0
bridge for libguestfs networking instead of SLIRP.  We thought SLIRP
was going to become unsupported in qemu, but recently there have been
more encouraging signs since it looks like SLIRP will be spun off as a
separate project, running as a modular process and properly secured
and supported.

This reverts commit 224de20b9a8d5ea56f6337f19b4ca237bb88eca0.

(cherry picked from commit 492a945791b43f80a769a53e60d0899b3d7c60ab)
---
 lib/guestfs-internal.h | 11 +++++
 lib/guestfs.pod        | 10 -----
 lib/launch-direct.c    | 11 -----
 lib/launch-libvirt.c   | 91 ++++++++++--------------------------------
 4 files changed, 32 insertions(+), 91 deletions(-)

diff --git a/lib/guestfs-internal.h b/lib/guestfs-internal.h
index adeb9478a..fe3a0e3b9 100644
--- a/lib/guestfs-internal.h
+++ b/lib/guestfs-internal.h
@@ -147,6 +147,17 @@
 #define MACHINE_TYPE "pseries"
 #endif
 
+/* Differences in qemu device names on ARMv7 (virtio-mmio), s/390x
+ * (CCW) vs normal hardware with PCI.
+ */
+#if defined(__arm__)
+#define VIRTIO_DEVICE_NAME(type) type "-device"
+#elif defined(__s390x__)
+#define VIRTIO_DEVICE_NAME(type) type "-ccw"
+#else
+#define VIRTIO_DEVICE_NAME(type) type "-pci"
+#endif
+
 /* Guestfs handle and associated structures. */
 
 /* State. */
diff --git a/lib/guestfs.pod b/lib/guestfs.pod
index 4b24006df..c7fbeef03 100644
--- a/lib/guestfs.pod
+++ b/lib/guestfs.pod
@@ -1551,16 +1551,6 @@ On Fedora, install C<kernel-debuginfo> for the C<vmlinux> file
 (containing symbols).  Make sure the symbols precisely match the
 kernel being used.
 
-=head3 network_bridge
-
-The libvirt backend supports:
-
- export LIBGUESTFS_BACKEND_SETTINGS=network_bridge=virbrX
-
-This allows you to override the bridge that is connected to when the
-network is enabled.  The default is C<virbr0>.  See also
-L</guestfs_set_network>.
-
 =head2 ATTACHING TO RUNNING DAEMONS
 
 I<Note (1):> This is B<highly experimental> and has a tendency to eat
diff --git a/lib/launch-direct.c b/lib/launch-direct.c
index 47e8f37de..f6c494d69 100644
--- a/lib/launch-direct.c
+++ b/lib/launch-direct.c
@@ -49,17 +49,6 @@
 #include "guestfs_protocol.h"
 #include "qemuopts.h"
 
-/* Differences in qemu device names on ARMv7 (virtio-mmio), s/390x
- * (CCW) vs normal hardware with PCI.
- */
-#if defined(__arm__)
-#define VIRTIO_DEVICE_NAME(type) type "-device"
-#elif defined(__s390x__)
-#define VIRTIO_DEVICE_NAME(type) type "-ccw"
-#else
-#define VIRTIO_DEVICE_NAME(type) type "-pci"
-#endif
-
 /* Per-handle data. */
 struct backend_direct_data {
   pid_t pid;                    /* Qemu PID. */
diff --git a/lib/launch-libvirt.c b/lib/launch-libvirt.c
index 7121aee1b..4df26825a 100644
--- a/lib/launch-libvirt.c
+++ b/lib/launch-libvirt.c
@@ -116,7 +116,6 @@ struct backend_libvirt_data {
   char *selinux_label;
   char *selinux_imagelabel;
   bool selinux_norelabel_disks;
-  char *network_bridge;
   char name[DOMAIN_NAME_LEN];   /* random name */
   bool is_kvm;                  /* false = qemu, true = kvm (from capabilities)*/
   struct version libvirt_version; /* libvirt version */
@@ -157,7 +156,6 @@ static int is_blk (const char *path);
 static void ignore_errors (void *ignore, virErrorPtr ignore2);
 static void set_socket_create_context (guestfs_h *g);
 static void clear_socket_create_context (guestfs_h *g);
-static int check_bridge_exists (guestfs_h *g, const char *brname);
 
 #if HAVE_LIBSELINUX
 static void selinux_warning (guestfs_h *g, const char *func, const char *selinux_op, const char *data);
@@ -438,17 +436,8 @@ launch_libvirt (guestfs_h *g, void *datav, const char *libvirt_uri)
     guestfs_get_backend_setting (g, "internal_libvirt_imagelabel");
   data->selinux_norelabel_disks =
     guestfs_int_get_backend_setting_bool (g, "internal_libvirt_norelabel_disks");
-  if (g->enable_network) {
-    data->network_bridge =
-      guestfs_get_backend_setting (g, "network_bridge");
-    if (!data->network_bridge)
-      data->network_bridge = safe_strdup (g, "virbr0");
-  }
   guestfs_pop_error_handler (g);
 
-  if (g->enable_network && check_bridge_exists (g, data->network_bridge) == -1)
-    goto cleanup;
-
   /* Locate and/or build the appliance. */
   TRACE0 (launch_build_libvirt_appliance_start);
 
@@ -1403,19 +1392,6 @@ construct_libvirt_xml_devices (guestfs_h *g,
       } end_element ();
     } end_element ();
 
-    /* Connect to libvirt bridge (see: RHBZ#1148012). */
-    if (g->enable_network) {
-      start_element ("interface") {
-        attribute ("type", "bridge");
-        start_element ("source") {
-          attribute ("bridge", params->data->network_bridge);
-        } end_element ();
-        start_element ("model") {
-          attribute ("type", "virtio");
-        } end_element ();
-      } end_element ();
-    }
-
     /* Libvirt adds some devices by default.  Indicate to libvirt
      * that we don't want them.
      */
@@ -1823,6 +1799,27 @@ construct_libvirt_xml_qemu_cmdline (guestfs_h *g,
       attribute ("value", tmpdir);
     } end_element ();
 
+    /* Workaround because libvirt user networking cannot specify "net="
+     * parameter.
+     */
+    if (g->enable_network) {
+      start_element ("qemu:arg") {
+        attribute ("value", "-netdev");
+      } end_element ();
+
+      start_element ("qemu:arg") {
+        attribute ("value", "user,id=usernet,net=169.254.0.0/16");
+      } end_element ();
+
+      start_element ("qemu:arg") {
+        attribute ("value", "-device");
+      } end_element ();
+
+      start_element ("qemu:arg") {
+        attribute ("value", VIRTIO_DEVICE_NAME ("virtio-net") ",netdev=usernet");
+      } end_element ();
+    }
+
     /* The qemu command line arguments requested by the caller. */
     for (hp = g->hv_params; hp; hp = hp->next) {
       start_element ("qemu:arg") {
@@ -2060,49 +2057,6 @@ is_blk (const char *path)
   return S_ISBLK (statbuf.st_mode);
 }
 
-static int
-is_dir (const char *path)
-{
-  struct stat statbuf;
-
-  if (stat (path, &statbuf) == -1)
-    return 0;
-  return S_ISDIR (statbuf.st_mode);
-}
-
-/* Used to check the network_bridge exists, or give a useful error
- * message.
- */
-static int
-check_bridge_exists (guestfs_h *g, const char *brname)
-{
-  CLEANUP_FREE char *path = NULL;
-
-  /* If this doesn't look like Linux, give up. */
-  if (!is_dir ("/sys/class/net"))
-    return 0;
-
-  /* Does the interface exist and is it a bridge? */
-  path = safe_asprintf (g, "/sys/class/net/%s/bridge", brname);
-  if (is_dir (path))
-    return 0;
-
-  error (g,
-         _("bridge ‘%s’ not found.  Try running:\n"
-           "\n"
-           "  brctl show\n"
-           "\n"
-           "to get a list of bridges on the host, and then selecting the\n"
-           "bridge you wish the appliance network to connect to using:\n"
-           "\n"
-           "  export LIBGUESTFS_BACKEND_SETTINGS=network_bridge=<bridge name>\n"
-           "\n"
-           "You may also need to allow the bridge in /etc/qemu/bridge.conf.\n"
-           "For further information see guestfs(3)."),
-	 brname);
-  return -1;
-}
-
 static void
 ignore_errors (void *ignore, virErrorPtr ignore2)
 {
@@ -2148,9 +2102,6 @@ shutdown_libvirt (guestfs_h *g, void *datav, int check_for_errors)
   free (data->selinux_imagelabel);
   data->selinux_imagelabel = NULL;
 
-  free (data->network_bridge);
-  data->network_bridge = NULL;
-
   for (i = 0; i < data->nr_secrets; ++i)
     free (data->secrets[i].secret);
   free (data->secrets);
-- 
2.21.0