virtxml: auto detect available network interface wipwip

1 files changed, 97 insertions, 1 deletions

diff --git a/examples/virt-designer.c b/examples/virt-designer.c
index f134b98..32708a8 100644
--- a/examples/virt-designer.c
+++ b/examples/virt-designer.c
@@ -24,10 +24,13 @@
 #include <libvirt-designer/libvirt-designer.h>
 #include <libvirt-gobject/libvirt-gobject.h>
 
+#include <errno.h>
+#include <net/if.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
 #include <string.h>
+#include <sys/ioctl.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
@@ -363,6 +366,99 @@ add_iface_str(const gchar *option_name,
     return TRUE;
 }
 
+static gpointer has_unpriviledged_libvirt_bridge_once(gpointer user_data)
+{
+    int sock = -1;
+    struct ifreq ifr;
+    gboolean can_use_bridge = FALSE;
+    GError *error = NULL;
+    char *contents = NULL;
+
+    sock = socket(PF_INET, SOCK_STREAM, 0);
+    if (sock < 1) {
+        g_warning("socket() failed: %s", strerror(errno));
+        goto end;
+    }
+
+    memset(&ifr, 0, sizeof(ifr));
+    strncpy(ifr.ifr_name, "virbr0", IFNAMSIZ);
+    if (ioctl(sock, SIOCGIFFLAGS, &ifr) < 0) {
+        g_warning("ioctl(SIOCGIFFLAGS) failed: %s", strerror(errno));
+        goto end;
+    }
+    if (!(ifr.ifr_flags & IFF_UP)) {
+        g_debug("virbr0 is not up");
+        goto end;
+    }
+
+    if (!g_file_get_contents("/etc/qemu/bridge.conf", &contents, NULL, &error)) {
+        g_debug("Could not load /etc/qemu/bridge.conf: %s", error->message);
+        goto end;
+    }
+
+    if (g_regex_match_simple("^\\s*allow\\s*virbr0\\b", contents, 0, 0)) {
+        can_use_bridge = TRUE;
+    }
+
+end:
+    if (sock >= 0) {
+        close(sock);
+    }
+    if (error != NULL) {
+        g_error_free(error);
+    }
+    g_free(contents);
+
+    return GINT_TO_POINTER(can_use_bridge);
+}
+
+static gboolean has_unpriviledged_libvirt_bridge(void)
+{
+    GOnce libvirt_bridge = G_ONCE_INIT;
+    gpointer ret;
+
+    ret = g_once(&libvirt_bridge,
+                 has_unpriviledged_libvirt_bridge_once,
+                 NULL);
+
+    return GPOINTER_TO_INT(ret);
+}
+
+static void add_network_interface(GVirConnection *conn,
+                                  GVirDesignerDomain *domain,
+                                  GList *interfaces)
+{
+    const char *libvirt_uri;
+    gboolean unpriviledged = FALSE;
+    GVirConfigDomainInterface *iface;
+
+    if (interfaces != NULL) {
+        g_list_foreach(iface_str_list, add_iface, domain);
+        return;
+    }
+
+    /* This logic could eventually go in libvirt-builder */
+    libvirt_uri = gvir_connection_get_uri(conn);
+    if (g_strcmp0(libvirt_uri, "qemu:///session") == 0) {
+        unpriviledged = TRUE;
+    }
+
+    if (unpriviledged) {
+        if (has_unpriviledged_libvirt_bridge()) {
+            iface = gvir_designer_domain_add_interface_bridge(domain, "virbr0", NULL);
+        } else {
+            iface = gvir_designer_domain_add_interface_user(domain, NULL);
+        }
+        //gvir_designer_domain_add_interface_bridge(domain, "virbr0", NULL);
+    } else {
+        iface = gvir_designer_domain_add_interface_network(domain, "default", NULL);
+    }
+
+    if (iface != NULL) {
+        g_object_unref(iface);
+    }
+}
+
 static OsinfoEntity *
 find_entity_by_short_id(OsinfoList *ent_list,
                         const char *short_id)
@@ -718,7 +814,7 @@ main(int argc, char *argv[])
 
     g_list_foreach(floppy_str_list, add_floppy, domain);
 
-    g_list_foreach(iface_str_list, add_iface, domain);
+    add_network_interface(conn, domain, iface_str_list);
 
     config = gvir_designer_domain_get_config(domain);
     xml = gvir_config_object_to_xml(GVIR_CONFIG_OBJECT(config));