Support openvswitch bridges

configure.ac

@@ -190,6 +190,16 @@ fi
 
 AM_CONDITIONAL([ENABLE_API_DOCS], [test "x$HAVE_DOXYGEN" != "x"])
 
+# Openvswitch
+AC_PATH_PROG([OVS_CTL_PATH],[ovs-vsctl])
+if test "x$OVS_CTL_PATH" != "x"; then
+	enable_ovs="yes"
+	AS_AC_EXPAND(OVS_CTL_PATH, "$OVS_CTL_PATH")
+else
+	enable_ovs="no"
+fi
+AM_CONDITIONAL([HAVE_OVS], [test "x$enable_ovs" = "xyes"])
+
 # Apparmor
 AC_ARG_ENABLE([apparmor],
 	[AC_HELP_STRING([--enable-apparmor], [enable apparmor support [default=auto]])],
@@ -755,6 +765,7 @@ Environment:
  - rpath: $enable_rpath
  - GnuTLS: $enable_gnutls
  - Bash integration: $enable_bash
+ - Openvswitch: $enable_ovs
 
 Security features:
  - Apparmor: $enable_apparmor

src/lxc/Makefile.am

@@ -128,6 +128,10 @@ if ENABLE_APPARMOR
 AM_CFLAGS += -DHAVE_APPARMOR
 endif
 
+if HAVE_OVS
+AM_CFLAGS += -DHAVE_OVS -DOVS_CTL_PATH=\"$(OVS_CTL_PATH)\"
+endif
+
 if ENABLE_CGMANAGER
 AM_CFLAGS += -DHAVE_CGMANAGER
 endif

src/lxc/network.c

@@ -48,6 +48,7 @@
 #include "nl.h"
 #include "network.h"
 #include "conf.h"
+#include "utils.h"
 
 #if HAVE_IFADDRS_H
 #include <ifaddrs.h>
@@ -1170,6 +1171,45 @@ int lxc_ipv6_dest_add(int ifindex, struct in6_addr *dest)
 	return ip_route_dest_add(AF_INET6, ifindex, dest);
 }
 
+#ifdef HAVE_OVS
+static bool is_ovs_bridge(const char *bridge)
+{
+	char brdirname[22 + IFNAMSIZ + 1] = {0};
+	struct stat sb;
+
+	snprintf(brdirname, 22 +IFNAMSIZ + 1, "/sys/class/net/%s/bridge", bridge);
+	if (stat(brdirname, &sb) == -1 && errno == ENOENT)
+		return true;
+	return false;
+}
+
+static int attach_to_ovs_bridge(const char *bridge, const char *nic)
+{
+	pid_t pid;
+	const char *progname;
+
+	pid = fork();
+	if (pid < 0)
+		return -1;
+	if (pid > 0)
+		return wait_for_pid(pid);
+
+	progname = strrchr(OVS_CTL_PATH, '/');
+	if (!progname) // not sane, should we just fail?
+		progname = OVS_CTL_PATH;
+	if (execl(OVS_CTL_PATH, progname, "add-port", bridge, nic, NULL))
+		exit(1);
+	// not reached
+	exit(1);
+}
+#else
+static inline bool is_ovs_bridge(const char *bridge) { return false; }
+static inline int attach_to_ovs_bridge(const char *bridge, const char *nic)
+{
+	retun -1;
+}
+#endif
+
 /*
  * There is a lxc_bridge_attach, but no need of a bridge detach
  * as automatically done by kernel when a netdev is deleted.
@@ -1186,6 +1226,9 @@ int lxc_bridge_attach(const char *bridge, const char *ifname)
 	if (!index)
 		return -EINVAL;
 
+	if (is_ovs_bridge(bridge))
+		return attach_to_ovs_bridge(bridge, ifname);
+
 	fd = socket(AF_INET, SOCK_STREAM, 0);
 	if (fd < 0)
 		return -errno;