[PATCH v2 13/15] libxl: call hotplug scripts for nic devices from libxl

[Roger Pau Monne <roger.pau@citrix.com>]

Since most of the needed work is already done in previous patches,
this patch only contains the necessary code to call hotplug scripts
for nic devices, that should be called when the device is added or
removed from a guest.

Changes since v1:

 * Move event code to libxl_device.c (as in previous patch).

Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
---
 tools/hotplug/Linux/xen-backend.rules |    6 +-
 tools/libxl/libxl_device.c            |   34 +++++++++++++-
 tools/libxl/libxl_internal.h          |    5 ++-
 tools/libxl/libxl_linux.c             |   84 ++++++++++++++++++++++++++++++++-
 4 files changed, 122 insertions(+), 7 deletions(-)

diff --git a/tools/hotplug/Linux/xen-backend.rules b/tools/hotplug/Linux/xen-backend.rules
index d55ff11..c591a3f 100644
--- a/tools/hotplug/Linux/xen-backend.rules
+++ b/tools/hotplug/Linux/xen-backend.rules
@@ -2,8 +2,8 @@ SUBSYSTEM=="xen-backend", KERNEL=="tap*", ENV{UDEV_CALL}="1", RUN+="/etc/xen/scr
 SUBSYSTEM=="xen-backend", KERNEL=="vbd*", ENV{UDEV_CALL}="1", RUN+="/etc/xen/scripts/block $env{ACTION}"
 SUBSYSTEM=="xen-backend", KERNEL=="vtpm*", RUN+="/etc/xen/scripts/vtpm $env{ACTION}"
 SUBSYSTEM=="xen-backend", KERNEL=="vif2-*", RUN+="/etc/xen/scripts/vif2 $env{ACTION}"
-SUBSYSTEM=="xen-backend", KERNEL=="vif-*", ACTION=="online", RUN+="/etc/xen/scripts/vif-setup online type_if=vif"
-SUBSYSTEM=="xen-backend", KERNEL=="vif-*", ACTION=="offline", RUN+="/etc/xen/scripts/vif-setup offline type_if=vif"
+SUBSYSTEM=="xen-backend", KERNEL=="vif-*", ENV{UDEV_CALL}="1", ACTION=="online", RUN+="/etc/xen/scripts/vif-setup online type_if=vif"
+SUBSYSTEM=="xen-backend", KERNEL=="vif-*", ENV{UDEV_CALL}="1", ACTION=="offline", RUN+="/etc/xen/scripts/vif-setup offline type_if=vif"
 SUBSYSTEM=="xen-backend", KERNEL=="vscsi*", RUN+="/etc/xen/scripts/vscsi $env{ACTION}"
 SUBSYSTEM=="xen-backend", ACTION=="remove", ENV{UDEV_CALL}="1", RUN+="/etc/xen/scripts/xen-hotplug-cleanup"
 KERNEL=="evtchn", NAME="xen/%k"
@@ -13,4 +13,4 @@ KERNEL=="blktap-control", NAME="xen/blktap-2/control", MODE="0600"
 KERNEL=="gntdev", NAME="xen/%k", MODE="0600"
 KERNEL=="pci_iomul", NAME="xen/%k", MODE="0600"
 KERNEL=="tapdev[a-z]*", NAME="xen/blktap-2/tapdev%m", MODE="0600"
-SUBSYSTEM=="net", KERNEL=="vif*-emu", ACTION=="add", RUN+="/etc/xen/scripts/vif-setup $env{ACTION} type_if=tap"
+SUBSYSTEM=="net", KERNEL=="vif*-emu", ACTION=="add", ENV{UDEV_CALL}="1", RUN+="/etc/xen/scripts/vif-setup $env{ACTION} type_if=tap"
diff --git a/tools/libxl/libxl_device.c b/tools/libxl/libxl_device.c
index d7dd7a3..b7bcffa 100644
--- a/tools/libxl/libxl_device.c
+++ b/tools/libxl/libxl_device.c
@@ -100,6 +100,26 @@ out:
     return numdevs;
 }
 
+libxl_nic_type libxl__nic_type(libxl__gc *gc, libxl__device *dev)
+{
+    char *snictype, *be_path;
+    libxl_nic_type nictype;
+
+    be_path = libxl__device_backend_path(gc, dev);
+    snictype = libxl__xs_read(gc, XBT_NULL,
+                              GCSPRINTF("%s/%s", be_path, "type"));
+    if (!snictype) {
+        LOGE(ERROR, "unable to read nictype from %s", be_path);
+        return -1;
+    }
+    if (libxl_nic_type_from_string(snictype, &nictype) < 0) {
+        LOGE(ERROR, "unable to parse nictype from %s", be_path);
+        return -1;
+    }
+
+    return nictype;
+}
+
 int libxl__device_generic_add(libxl__gc *gc, libxl__device *device,
                              char **bents, char **fents)
 {
@@ -732,7 +752,8 @@ static void device_hotplug(libxl__egc *egc, libxl__ao_device *aodev)
     /* Check if we have to execute hotplug scripts for this device
      * and return the necessary args/env vars for execution */
     hotplug = libxl__get_hotplug_script_info(gc, aodev->dev, &args, &env,
-                                             aodev->action);
+                                             aodev->action,
+                                             aodev->vif_executed);
     switch (hotplug) {
     case 0:
         /* no hotplug script to execute */
@@ -806,7 +827,18 @@ static void device_hotplug_fork_cb(libxl__egc *egc, libxl__ev_child *child,
                                                      : LIBXL__LOG_WARNING,
                                       aodev->what, pid, status);
         aodev->rc = ERROR_FAIL;
+        goto out;
     }
+
+    if (aodev->dev->backend_kind == LIBXL__DEVICE_KIND_VIF &&
+        libxl__nic_type(gc, aodev->dev) == LIBXL_NIC_TYPE_IOEMU &&
+        !aodev->vif_executed) {
+        aodev->vif_executed = 1;
+        device_hotplug(egc, aodev);
+        return;
+    }
+
+out:
     aodev->callback(egc, aodev);
 }
 
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 4af35cb..68a6122 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -800,6 +800,7 @@ _hidden int libxl__parse_backend_path(libxl__gc *gc, const char *path,
                                       libxl__device *dev);
 _hidden int libxl__device_destroy(libxl__gc *gc, libxl__device *dev);
 _hidden int libxl__wait_for_backend(libxl__gc *gc, char *be_path, char *state);
+_hidden libxl_nic_type libxl__nic_type(libxl__gc *gc, libxl__device *dev);
 
 /*
  * For each aggregate type which can be used as an input we provide:
@@ -1796,6 +1797,7 @@ struct libxl__ao_device {
     /* device hotplug execution */
     pid_t pid;
     char *what;
+    int vif_executed;
     libxl__ev_time ev;
     libxl__ev_child child;
 };
@@ -1838,7 +1840,8 @@ _hidden void libxl__initiate_device_remove(libxl__egc *egc,
  */
 _hidden int libxl__get_hotplug_script_info(libxl__gc *gc, libxl__device *dev,
                                            char ***args, char ***env,
-                                           libxl__device_action action);
+                                           libxl__device_action action,
+                                           int vif_executed);
 
 /*----- Domain destruction -----*/
 
diff --git a/tools/libxl/libxl_linux.c b/tools/libxl/libxl_linux.c
index 83b85b3..bd37f7f 100644
--- a/tools/libxl/libxl_linux.c
+++ b/tools/libxl/libxl_linux.c
@@ -43,7 +43,7 @@ static char **get_hotplug_env(libxl__gc *gc, libxl__device *dev)
         return NULL;
     }
 
-    GCNEW_ARRAY(env, 9);
+    GCNEW_ARRAY(env, 13);
     env[nr++] = "script";
     env[nr++] = script;
     env[nr++] = "XENBUS_TYPE";
@@ -52,6 +52,24 @@ static char **get_hotplug_env(libxl__gc *gc, libxl__device *dev)
     env[nr++] = GCSPRINTF("backend/%s/%u/%d", type, dev->domid, dev->devid);
     env[nr++] = "XENBUS_BASE_PATH";
     env[nr++] = "backend";
+    if (dev->backend_kind == LIBXL__DEVICE_KIND_VIF) {
+        switch (libxl__nic_type(gc, dev)) {
+        case LIBXL_NIC_TYPE_IOEMU:
+            env[nr++] = "INTERFACE";
+            env[nr++] = libxl__strdup(gc, libxl__device_nic_devname(gc,
+                                                      dev->domid, dev->devid,
+                                                      LIBXL_NIC_TYPE_IOEMU));
+        case LIBXL_NIC_TYPE_VIF:
+            env[nr++] = "vif";
+            env[nr++] = libxl__strdup(gc, libxl__device_nic_devname(gc,
+                                                      dev->domid, dev->devid,
+                                                      LIBXL_NIC_TYPE_VIF));
+            break;
+        default:
+            return NULL;
+        }
+    }
+
     env[nr++] = NULL;
 
     return env;
@@ -59,6 +77,63 @@ static char **get_hotplug_env(libxl__gc *gc, libxl__device *dev)
 
 /* Hotplug scripts caller functions */
 
+static int libxl__hotplug_nic(libxl__gc *gc, libxl__device *dev,
+                               char ***args, char ***env,
+                               libxl__device_action action, int vif_executed)
+{
+    char *be_path = libxl__device_backend_path(gc, dev);
+    char *script;
+    int nr = 0, rc = 0;
+    libxl_nic_type nictype;
+
+    script = libxl__xs_read(gc, XBT_NULL, GCSPRINTF("%s/%s", be_path,
+                                                             "script"));
+    if (!script) {
+        LOGE(ERROR, "unable to read script from %s", be_path);
+        return -1;
+    }
+
+    nictype = libxl__nic_type(gc, dev);
+    if (nictype < 0) {
+        LOG(ERROR, "error when fetching nic type");
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    *env = get_hotplug_env(gc, dev);
+    if (!env) {
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    GCNEW_ARRAY(*args, 4);
+    (*args)[nr++] = script;
+
+    switch (nictype) {
+    case LIBXL_NIC_TYPE_IOEMU:
+        if (!vif_executed) goto execute_vif;
+        (*args)[nr++] = action == DEVICE_CONNECT ? "add" : "remove";
+        (*args)[nr++] = libxl__strdup(gc, "type_if=tap");
+        (*args)[nr++] = NULL;
+        break;
+    case LIBXL_NIC_TYPE_VIF:
+execute_vif:
+        (*args)[nr++] = action == DEVICE_CONNECT ? "online" : "offline";
+        (*args)[nr++] = libxl__strdup(gc, "type_if=vif");
+        (*args)[nr++] = NULL;
+        break;
+    default:
+        /* Unknown network type */
+        LOG(ERROR, "unknown network card type %s", be_path);
+        return 0;
+    }
+
+    rc = 0;
+
+out:
+    return rc;
+}
+
 static int libxl__hotplug_disk(libxl__gc *gc, libxl__device *dev,
                                char ***args, char ***env,
                                libxl__device_action action)
@@ -95,7 +170,8 @@ error:
 
 int libxl__get_hotplug_script_info(libxl__gc *gc, libxl__device *dev,
                                    char ***args, char ***env,
-                                   libxl__device_action action)
+                                   libxl__device_action action,
+                                   int vif_executed)
 {
     char *disable_udev = libxl__xs_read(gc, XBT_NULL, DISABLE_UDEV_PATH);
     int rc;
@@ -111,6 +187,10 @@ int libxl__get_hotplug_script_info(libxl__gc *gc, libxl__device *dev,
         rc = libxl__hotplug_disk(gc, dev, args, env, action);
         if (!rc) rc = 1;
         break;
+    case LIBXL__DEVICE_KIND_VIF:
+        rc = libxl__hotplug_nic(gc, dev, args, env, action, vif_executed);
+        if (!rc) rc = 1;
+        break;
     default:
         /* If no need to execute any hotplug scripts,
          * call the callback manually
-- 
1.7.7.5 (Apple Git-26)