platform: add support for kernel IPv6LL address generation modes

This patch requires both upstream kernel support for
IFLA_INET6_ADDR_GEN_MODE which was merged in this patch:

ipv6: addrconf: implement address generation modes
bc91b0f07ada5535427373a4e2050877bcc12218

and corresponding libnl support, merged in these patches:

veth: add kernel header linux/veth.h for VETH defines
9dc6e6da90016a33929f262bea0187396e1a061b

link: update copy of kernel header include/linux/if_link.h
b51815a9dbd8e45fd2558bbe337fb360ca2fd861

link/inet6: add link IPv6 address generation mode support
558f966782539f6d975da705fd73cea561c9dc83

configure.ac

@@ -386,6 +386,25 @@ PKG_CHECK_MODULES(LIBNL, libnl-3.0 >= 3.2.8 libnl-route-3.0 libnl-genl-3.0)
 AC_SUBST(LIBNL_CFLAGS)
 AC_SUBST(LIBNL_LIBS)
 
+AC_CHECK_LIB([nl-route-3], [rtnl_link_inet6_get_addr_gen_mode],
+	ac_have_addr_gen_mode="1",
+	ac_have_addr_gen_mode="0")
+AC_DEFINE_UNQUOTED(HAVE_LIBNL_INET6_ADDR_GEN_MODE,
+	$ac_have_addr_gen_mode, [Define if libnl has rtnl_link_inet6_get_addr_gen_mode()])
+
+AC_MSG_CHECKING([Linux kernel IN6_ADDR_GEN_MODE enum])
+AC_COMPILE_IFELSE(
+	[AC_LANG_PROGRAM(
+              [[#ifndef __user
+                #define __user
+                #endif
+                #include <linux/if_link.h>]],
+              [[int a = IN6_ADDR_GEN_MODE_EUI64; a++;]])],
+        [ac_have_kernel_gen_mode="1"],
+        [ac_have_kernel_gen_mode="0"])
+AC_DEFINE_UNQUOTED(HAVE_KERNEL_INET6_ADDR_GEN_MODE,
+	$ac_have_kernel_gen_mode, [Define if the kernel has IN6_ADDR_GEN_MODE_*])
+
 # uuid library
 PKG_CHECK_MODULES(UUID, uuid)
 AC_SUBST(UUID_CFLAGS)

src/platform/nm-linux-platform.c

@@ -44,6 +44,16 @@
 #include <netlink/route/route.h>
 #include <gudev/gudev.h>
 
+#if HAVE_LIBNL_INET6_ADDR_GEN_MODE
+#include <netlink/route/link/inet6.h>
+#if HAVE_KERNEL_INET6_ADDR_GEN_MODE
+#include <linux/if_link.h>
+#else
+#define IN6_ADDR_GEN_MODE_EUI64 0
+#define IN6_ADDR_GEN_MODE_NONE  1
+#endif
+#endif
+
 #include "NetworkManagerUtils.h"
 #include "nm-linux-platform.h"
 #include "NetworkManagerUtils.h"
@@ -83,6 +93,7 @@ typedef struct {
 	GHashTable *wifi_data;
 
 	int support_kernel_extended_ifa_flags;
+	int support_user_ipv6ll;
 } NMLinuxPlatformPrivate;
 
 #define NM_LINUX_PLATFORM_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), NM_TYPE_LINUX_PLATFORM, NMLinuxPlatformPrivate))
@@ -669,6 +680,23 @@ check_support_kernel_extended_ifa_flags (NMPlatform *platform)
 	return priv->support_kernel_extended_ifa_flags > 0;
 }
 
+static gboolean
+check_support_user_ipv6ll (NMPlatform *platform)
+{
+	NMLinuxPlatformPrivate *priv;
+
+	g_return_val_if_fail (NM_IS_LINUX_PLATFORM (platform), FALSE);
+
+	priv = NM_LINUX_PLATFORM_GET_PRIVATE (platform);
+
+	if (priv->support_user_ipv6ll == 0) {
+		nm_log_warn (LOGD_PLATFORM, "Unable to detect kernel support for IFLA_INET6_ADDR_GEN_MODE. Assume no kernel support.");
+		priv->support_user_ipv6ll = -1;
+	}
+
+	return priv->support_user_ipv6ll > 0;
+}
+
 
 /* Object type specific utilities */
 
@@ -1529,8 +1557,20 @@ announce_object (NMPlatform *platform, const struct nl_object *object, NMPlatfor
 	switch (object_type) {
 	case OBJECT_TYPE_LINK:
 		{
-			NMPlatformLink device;
 			struct rtnl_link *rtnl_link = (struct rtnl_link *) object;
+			NMPlatformLink device;
+
+#if HAVE_LIBNL_INET6_ADDR_GEN_MODE
+			/* If we ever see a link with valid IPv6 link-local address
+			 * generation modes, the kernel supports it.
+			 */
+			if (priv->support_user_ipv6ll == 0) {
+				uint8_t mode;
+
+				if (rtnl_link_inet6_get_addr_gen_mode (rtnl_link, &mode) == 0)
+					priv->support_user_ipv6ll = 1;
+			}
+#endif
 
 			if (!init_link (platform, &device, rtnl_link))
 				return;
@@ -2405,6 +2445,46 @@ link_set_noarp (NMPlatform *platform, int ifindex)
 	return link_change_flags (platform, ifindex, IFF_NOARP, TRUE);
 }
 
+static gboolean
+link_get_user_ipv6ll_enabled (NMPlatform *platform, int ifindex)
+{
+#if HAVE_LIBNL_INET6_ADDR_GEN_MODE
+	NMLinuxPlatformPrivate *priv = NM_LINUX_PLATFORM_GET_PRIVATE (platform);
+
+	if (priv->support_user_ipv6ll > 0) {
+		auto_nl_object struct rtnl_link *rtnllink = link_get (platform, ifindex);
+		uint8_t mode = 0;
+
+		if (rtnllink) {
+			if (rtnl_link_inet6_get_addr_gen_mode (rtnllink, &mode) != 0) {
+				/* Default to "disabled" on error */
+				return FALSE;
+			}
+			return mode == IN6_ADDR_GEN_MODE_NONE;
+		}
+	}
+#endif
+	return FALSE;
+}
+
+static gboolean
+link_set_user_ipv6ll_enabled (NMPlatform *platform, int ifindex, gboolean enabled)
+{
+#if HAVE_LIBNL_INET6_ADDR_GEN_MODE
+	if (check_support_user_ipv6ll (platform)) {
+		auto_nl_object struct rtnl_link *change = _nm_rtnl_link_alloc (ifindex, NULL);
+		guint8 mode = enabled ? IN6_ADDR_GEN_MODE_NONE : IN6_ADDR_GEN_MODE_EUI64;
+		char buf[32];
+
+		rtnl_link_inet6_set_addr_gen_mode (change, mode);
+		debug ("link: change %d: set IPv6 address generation mode to %s",
+		       ifindex, rtnl_link_inet6_addrgenmode2str (mode, buf, sizeof (buf)));
+		return link_change (platform, ifindex, change);
+	}
+#endif
+	return FALSE;
+}
+
 static gboolean
 supports_ethtool_carrier_detect (const char *ifname)
 {
@@ -4060,6 +4140,24 @@ setup (NMPlatform *platform)
 	for (object = nl_cache_get_first (priv->address_cache); object; object = nl_cache_get_next (object))
 		_rtnl_addr_hack_lifetimes_rel_to_abs ((struct rtnl_addr *) object);
 
+#if HAVE_LIBNL_INET6_ADDR_GEN_MODE
+	/* Initial check for user IPv6LL support once the link cache is allocated
+	 * and filled.  If there are no links in the cache yet then we'll check
+	 * when a new link shows up in announce_object().
+	 */
+	object = nl_cache_get_first (priv->link_cache);
+	if (object) {
+		uint8_t mode;
+
+		if (rtnl_link_inet6_get_addr_gen_mode ((struct rtnl_link *) object, &mode) == 0)
+			priv->support_user_ipv6ll = 1;
+		else
+			priv->support_user_ipv6ll = -1;
+	}
+#else
+	priv->support_user_ipv6ll = -1;
+#endif
+
 	/* Set up udev monitoring */
 	priv->udev_client = g_udev_client_new (udev_subsys);
 	g_signal_connect (priv->udev_client, "uevent", G_CALLBACK (handle_udev_event), platform);
@@ -4147,6 +4245,9 @@ nm_linux_platform_class_init (NMLinuxPlatformClass *klass)
 	platform_class->link_is_connected = link_is_connected;
 	platform_class->link_uses_arp = link_uses_arp;
 
+	platform_class->link_get_user_ipv6ll_enabled = link_get_user_ipv6ll_enabled;
+	platform_class->link_set_user_ipv6ll_enabled = link_set_user_ipv6ll_enabled;
+
 	platform_class->link_get_address = link_get_address;
 	platform_class->link_set_address = link_set_address;
 	platform_class->link_get_mtu = link_get_mtu;
@@ -4213,4 +4314,5 @@ nm_linux_platform_class_init (NMLinuxPlatformClass *klass)
 	platform_class->ip6_route_exists = ip6_route_exists;
 
 	platform_class->check_support_kernel_extended_ifa_flags = check_support_kernel_extended_ifa_flags;
+	platform_class->check_support_user_ipv6ll = check_support_user_ipv6ll;
 }

src/platform/nm-platform.c

@@ -215,6 +215,21 @@ nm_platform_check_support_kernel_extended_ifa_flags ()
 	return klass->check_support_kernel_extended_ifa_flags (platform);
 }
 
+gboolean
+nm_platform_check_support_user_ipv6ll (void)
+{
+	static int supported = -1;
+
+	g_return_val_if_fail (NM_IS_PLATFORM (platform), FALSE);
+
+	if (!klass->check_support_user_ipv6ll)
+		return FALSE;
+
+	if (supported < 0)
+		supported = klass->check_support_user_ipv6ll (platform) ? 1 : 0;
+	return !!supported;
+}
+
 /******************************************************************/
 
 /**
@@ -729,6 +744,52 @@ nm_platform_link_uses_arp (int ifindex)
 	return klass->link_uses_arp (platform, ifindex);
 }
 
+/**
+ * nm_platform_link_get_user_ip6vll_enabled:
+ * @ifindex: Interface index
+ *
+ * Check whether NM handles IPv6LL address creation for the link.  If the
+ * platform or OS doesn't support changing the IPv6LL address mode, this call
+ * will fail and return %FALSE.
+ *
+ * Returns: %TRUE if NM handles the IPv6LL address for @ifindex
+ */
+gboolean
+nm_platform_link_get_user_ipv6ll_enabled (int ifindex)
+{
+	reset_error ();
+
+	g_return_val_if_fail (ifindex >= 0, FALSE);
+	g_return_val_if_fail (klass->check_support_user_ipv6ll, FALSE);
+
+	if (klass->link_get_user_ipv6ll_enabled)
+		return klass->link_get_user_ipv6ll_enabled (platform, ifindex);
+	return FALSE;
+}
+
+/**
+ * nm_platform_link_set_user_ip6vll_enabled:
+ * @ifindex: Interface index
+ *
+ * Set whether NM handles IPv6LL address creation for the link.  If the
+ * platform or OS doesn't support changing the IPv6LL address mode, this call
+ * will fail and return %FALSE.
+ *
+ * Returns: %TRUE if the operation was successful, %FALSE if it failed.
+ */
+gboolean
+nm_platform_link_set_user_ipv6ll_enabled (int ifindex, gboolean enabled)
+{
+	reset_error ();
+
+	g_return_val_if_fail (ifindex >= 0, FALSE);
+	g_return_val_if_fail (klass->check_support_user_ipv6ll, FALSE);
+
+	if (klass->link_set_user_ipv6ll_enabled)
+		return klass->link_set_user_ipv6ll_enabled (platform, ifindex, enabled);
+	return FALSE;
+}
+
 /**
  * nm_platform_link_set_address:
  * @ifindex: Interface index

src/platform/nm-platform.h

@@ -388,6 +388,9 @@ typedef struct {
 	gboolean (*link_is_connected) (NMPlatform *, int ifindex);
 	gboolean (*link_uses_arp) (NMPlatform *, int ifindex);
 
+	gboolean (*link_get_user_ipv6ll_enabled) (NMPlatform *, int ifindex);
+	gboolean (*link_set_user_ipv6ll_enabled) (NMPlatform *, int ifindex, gboolean enabled);
+
 	gconstpointer (*link_get_address) (NMPlatform *, int ifindex, size_t *length);
 	gboolean (*link_set_address) (NMPlatform *, int ifindex, gconstpointer address, size_t length);
 	guint32 (*link_get_mtu) (NMPlatform *, int ifindex);
@@ -463,6 +466,7 @@ typedef struct {
 	gboolean (*ip6_route_exists) (NMPlatform *, int ifindex, struct in6_addr network, int plen, int metric);
 
 	gboolean (*check_support_kernel_extended_ifa_flags) (NMPlatform *);
+	gboolean (*check_support_user_ipv6ll) (NMPlatform *);
 } NMPlatformClass;
 
 /* NMPlatform signals
@@ -528,6 +532,9 @@ gboolean nm_platform_link_is_up (int ifindex);
 gboolean nm_platform_link_is_connected (int ifindex);
 gboolean nm_platform_link_uses_arp (int ifindex);
 
+gboolean nm_platform_link_get_user_ipv6ll_enabled (int ifindex);
+gboolean nm_platform_link_set_user_ipv6ll_enabled (int ifindex, gboolean enabled);
+
 gconstpointer nm_platform_link_get_address (int ifindex, size_t *length);
 gboolean nm_platform_link_set_address (int ifindex, const void *address, size_t length);
 guint32 nm_platform_link_get_mtu (int ifindex);
@@ -623,6 +630,7 @@ int nm_platform_ip6_route_cmp (const NMPlatformIP6Route *a, const NMPlatformIP6R
 
 gboolean nm_platform_check_support_libnl_extended_ifa_flags (void);
 gboolean nm_platform_check_support_kernel_extended_ifa_flags (void);
+gboolean nm_platform_check_support_user_ipv6ll (void);
 
 void nm_platform_addr_flags2str (int flags, char *buf, size_t size);