platform: refactor detecting kernel support

We are going to add another parameter to check. Instead of adding multiple
virtual functions, add a NMPlatformKernelSupportFlags flags enum.

6 files changed, 65 insertions, 49 deletions

diff --git a/src/devices/nm-device.c b/src/devices/nm-device.c
index fd6f840a75..0e9833bd3d 100644
--- a/src/devices/nm-device.c
+++ b/src/devices/nm-device.c
@@ -1203,7 +1203,8 @@ nm_device_set_ip_iface (NMDevice *self, const char *iface)
 	}
 
 	if (priv->ip_ifindex > 0) {
-		if (nm_platform_check_support_user_ipv6ll (nm_device_get_platform (self)))
+		if (nm_platform_check_kernel_support (nm_device_get_platform (self),
+		                                      NM_PLATFORM_KERNEL_SUPPORT_USER_IPV6LL))
 			nm_platform_link_set_user_ipv6ll_enabled (nm_device_get_platform (self), priv->ip_ifindex, TRUE);
 
 		if (!nm_platform_link_is_up (nm_device_get_platform (self), priv->ip_ifindex))
@@ -3308,7 +3309,8 @@ realize_start_setup (NMDevice *self,
 		if (priv->firmware_version)
 			_notify (self, PROP_FIRMWARE_VERSION);
 
-		if (nm_platform_check_support_user_ipv6ll (nm_device_get_platform (self)))
+		if (nm_platform_check_kernel_support (nm_device_get_platform (self),
+		                                      NM_PLATFORM_KERNEL_SUPPORT_USER_IPV6LL))
 			priv->nm_ipv6ll = nm_platform_link_get_user_ipv6ll_enabled (nm_device_get_platform (self), priv->ifindex);
 
 		if (nm_platform_link_supports_sriov (nm_device_get_platform (self), priv->ifindex))
@@ -7370,7 +7372,8 @@ ndisc_config_changed (NMNDisc *ndisc, const NMNDiscData *rdata, guint changed_in
 		 * addresses as /128. The reason for the /128 is to prevent the kernel
 		 * from adding a prefix route for this address. */
 		ifa_flags = 0;
-		if (nm_platform_check_support_kernel_extended_ifa_flags (nm_device_get_platform (self))) {
+		if (nm_platform_check_kernel_support (nm_device_get_platform (self),
+		                                      NM_PLATFORM_KERNEL_SUPPORT_EXTENDED_IFA_FLAGS)) {
 			ifa_flags |= IFA_F_NOPREFIXROUTE;
 			if (NM_IN_SET (priv->ndisc_use_tempaddr, NM_SETTING_IP6_CONFIG_PRIVACY_PREFER_TEMP_ADDR,
 			                                         NM_SETTING_IP6_CONFIG_PRIVACY_PREFER_PUBLIC_ADDR))
@@ -7586,7 +7589,8 @@ addrconf6_start (NMDevice *self, NMSettingIP6ConfigPrivacy use_tempaddr)
 	priv->ndisc_use_tempaddr = use_tempaddr;
 
 	if (   NM_IN_SET (use_tempaddr, NM_SETTING_IP6_CONFIG_PRIVACY_PREFER_TEMP_ADDR, NM_SETTING_IP6_CONFIG_PRIVACY_PREFER_PUBLIC_ADDR)
-	    && !nm_platform_check_support_kernel_extended_ifa_flags (nm_device_get_platform (self))) {
+	    && !nm_platform_check_kernel_support (nm_device_get_platform (self),
+	                                          NM_PLATFORM_KERNEL_SUPPORT_EXTENDED_IFA_FLAGS)) {
 		_LOGW (LOGD_IP6, "The kernel does not support extended IFA_FLAGS needed by NM for "
 		                 "IPv6 private addresses. This feature is not available");
 	}
@@ -7686,7 +7690,8 @@ set_nm_ipv6ll (NMDevice *self, gboolean enable)
 	int ifindex = nm_device_get_ip_ifindex (self);
 	char *value;
 
-	if (!nm_platform_check_support_user_ipv6ll (nm_device_get_platform (self)))
+	if (!nm_platform_check_kernel_support (nm_device_get_platform (self),
+	                                       NM_PLATFORM_KERNEL_SUPPORT_USER_IPV6LL))
 		return;
 
 	priv->nm_ipv6ll = enable;
diff --git a/src/nm-iface-helper.c b/src/nm-iface-helper.c
index 4be92bfb44..8f6331e3c9 100644
--- a/src/nm-iface-helper.c
+++ b/src/nm-iface-helper.c
@@ -183,7 +183,8 @@ ndisc_config_changed (NMNDisc *ndisc, const NMNDiscData *rdata, guint changed_in
 		 * addresses as /128. The reason for the /128 is to prevent the kernel
 		 * from adding a prefix route for this address. */
 		ifa_flags = 0;
-		if (nm_platform_check_support_kernel_extended_ifa_flags (NM_PLATFORM_GET)) {
+		if (nm_platform_check_kernel_support (NM_PLATFORM_GET,
+		                                      NM_PLATFORM_KERNEL_SUPPORT_EXTENDED_IFA_FLAGS)) {
 			ifa_flags |= IFA_F_NOPREFIXROUTE;
 			if (NM_IN_SET (global_opt.tempaddr, NM_SETTING_IP6_CONFIG_PRIVACY_PREFER_TEMP_ADDR,
 			                                    NM_SETTING_IP6_CONFIG_PRIVACY_PREFER_PUBLIC_ADDR))
diff --git a/src/platform/nm-linux-platform.c b/src/platform/nm-linux-platform.c
index ee52446071..f7ce9851aa 100644
--- a/src/platform/nm-linux-platform.c
+++ b/src/platform/nm-linux-platform.c
@@ -3074,20 +3074,25 @@ sysctl_get (NMPlatform *platform, const char *pathid, int dirfd, const char *pat
 
 /*****************************************************************************/
 
-static gboolean
-check_support_kernel_extended_ifa_flags (NMPlatform *platform)
+static NMPlatformKernelSupportFlags
+check_kernel_support (NMPlatform *platform,
+                      NMPlatformKernelSupportFlags request_flags)
 {
+	NMPlatformKernelSupportFlags response = 0;
+
 	nm_assert (NM_IS_LINUX_PLATFORM (platform));
 
-	return _support_kernel_extended_ifa_flags_get ();
-}
+	if (NM_FLAGS_HAS (request_flags, NM_PLATFORM_KERNEL_SUPPORT_EXTENDED_IFA_FLAGS)) {
+		if (_support_kernel_extended_ifa_flags_get ())
+			response |= NM_PLATFORM_KERNEL_SUPPORT_EXTENDED_IFA_FLAGS;
+	}
 
-static gboolean
-check_support_user_ipv6ll (NMPlatform *platform)
-{
-	nm_assert (NM_IS_LINUX_PLATFORM (platform));
+	if (NM_FLAGS_HAS (request_flags, NM_PLATFORM_KERNEL_SUPPORT_USER_IPV6LL)) {
+		if (_support_user_ipv6ll_get ())
+			response |= NM_PLATFORM_KERNEL_SUPPORT_USER_IPV6LL;
+	}
 
-	return _support_user_ipv6ll_get ();
+	return response;
 }
 
 static void
@@ -6864,8 +6869,7 @@ nm_linux_platform_class_init (NMLinuxPlatformClass *klass)
 	platform_class->ip_route_delete = ip_route_delete;
 	platform_class->ip_route_get = ip_route_get;
 
-	platform_class->check_support_kernel_extended_ifa_flags = check_support_kernel_extended_ifa_flags;
-	platform_class->check_support_user_ipv6ll = check_support_user_ipv6ll;
+	platform_class->check_kernel_support = check_kernel_support;
 
 	platform_class->process_events = process_events;
 }
diff --git a/src/platform/nm-platform.c b/src/platform/nm-platform.c
index 9b0929757e..222b68f8e0 100644
--- a/src/platform/nm-platform.c
+++ b/src/platform/nm-platform.c
@@ -92,8 +92,8 @@ typedef struct _NMPlatformPrivate {
 	bool use_udev:1;
 	bool log_with_ptr:1;
 
-	gint8 check_support_kernel_extended_ifa_flags_cached;
-	gint8 check_support_user_ipv6ll_cached;
+	NMPlatformKernelSupportFlags support_checked;
+	NMPlatformKernelSupportFlags support_present;
 
 	guint ip4_dev_route_blacklist_check_id;
 	guint ip4_dev_route_blacklist_gc_timeout_id;
@@ -301,8 +301,9 @@ NM_UTILS_LOOKUP_STR_DEFINE_STATIC (_nmp_nlm_flag_to_string_lookup, NMPNlmFlags,
 
 /*****************************************************************************/
 
-gboolean
-nm_platform_check_support_kernel_extended_ifa_flags (NMPlatform *self)
+NMPlatformKernelSupportFlags
+nm_platform_check_kernel_support (NMPlatform *self,
+                                  NMPlatformKernelSupportFlags request_flags)
 {
 	NMPlatformPrivate *priv;
 
@@ -310,29 +311,28 @@ nm_platform_check_support_kernel_extended_ifa_flags (NMPlatform *self)
 
 	priv = NM_PLATFORM_GET_PRIVATE (self);
 
-	if (G_UNLIKELY (priv->check_support_kernel_extended_ifa_flags_cached == 0)) {
-		priv->check_support_kernel_extended_ifa_flags_cached = (   klass->check_support_kernel_extended_ifa_flags
-		                                                        && klass->check_support_kernel_extended_ifa_flags (self))
-		                                                       ? 1 : -1;
-	}
-	return priv->check_support_kernel_extended_ifa_flags_cached >= 0;
-}
-
-gboolean
-nm_platform_check_support_user_ipv6ll (NMPlatform *self)
-{
-	NMPlatformPrivate *priv;
-
-	_CHECK_SELF (self, klass, TRUE);
-
-	priv = NM_PLATFORM_GET_PRIVATE (self);
+	/* we cache the response from subclasses and only request it once.
+	 * This probably gives better performance, but more importantly,
+	 * we are guaranteed that the answer for a certain request_flag
+	 * is always the same. */
+	if (G_UNLIKELY (!NM_FLAGS_ALL (priv->support_checked, request_flags))) {
+		NMPlatformKernelSupportFlags checked, response;
+
+		checked = request_flags & ~priv->support_checked;
+		nm_assert (checked);
+
+		if (klass->check_kernel_support)
+			response = klass->check_kernel_support (self, checked);
+		else {
+			/* fake platform. Pretend no support for anything. */
+			response = 0;
+		}
 
-	if (G_UNLIKELY (priv->check_support_user_ipv6ll_cached == 0)) {
-		priv->check_support_user_ipv6ll_cached = (   klass->check_support_user_ipv6ll
-		                                          && klass->check_support_user_ipv6ll (self))
-		                                         ? 1 : -1;
+		priv->support_checked |= checked;
+		priv->support_present = (priv->support_present & ~checked) | (response & checked);
 	}
-	return priv->check_support_user_ipv6ll_cached >= 0;
+
+	return priv->support_present & request_flags;
 }
 
 /**
@@ -3421,7 +3421,7 @@ delete_and_next:
 	if (!known_addresses)
 		return TRUE;
 
-	ifa_flags =   nm_platform_check_support_kernel_extended_ifa_flags (self)
+	ifa_flags =   nm_platform_check_kernel_support (self, NM_PLATFORM_KERNEL_SUPPORT_EXTENDED_IFA_FLAGS)
 	            ? IFA_F_NOPREFIXROUTE
 	            : 0;
 
@@ -3503,7 +3503,7 @@ nm_platform_ip6_address_sync (NMPlatform *self,
 	if (!known_addresses)
 		return TRUE;
 
-	ifa_flags =   nm_platform_check_support_kernel_extended_ifa_flags (self)
+	ifa_flags =   nm_platform_check_kernel_support (self, NM_PLATFORM_KERNEL_SUPPORT_EXTENDED_IFA_FLAGS)
 	            ? IFA_F_NOPREFIXROUTE
 	            : 0;
 
diff --git a/src/platform/nm-platform.h b/src/platform/nm-platform.h
index 0f953f122d..3d6e5bf7f5 100644
--- a/src/platform/nm-platform.h
+++ b/src/platform/nm-platform.h
@@ -659,6 +659,11 @@ typedef enum {
 	NM_PLATFORM_LINK_DUPLEX_FULL,
 } NMPlatformLinkDuplexType;
 
+typedef enum {
+	NM_PLATFORM_KERNEL_SUPPORT_EXTENDED_IFA_FLAGS               = (1LL <<  0),
+	NM_PLATFORM_KERNEL_SUPPORT_USER_IPV6LL                      = (1LL <<  1),
+} NMPlatformKernelSupportFlags;
+
 /*****************************************************************************/
 
 struct _NMPlatformPrivate;
@@ -824,8 +829,8 @@ typedef struct {
 	                                 int oif_ifindex,
 	                                 NMPObject **out_route);
 
-	gboolean (*check_support_kernel_extended_ifa_flags) (NMPlatform *);
-	gboolean (*check_support_user_ipv6ll) (NMPlatform *);
+	NMPlatformKernelSupportFlags (*check_kernel_support) (NMPlatform * self,
+	                                                      NMPlatformKernelSupportFlags request_flags);
 } NMPlatformClass;
 
 /* NMPlatform signals
@@ -1315,8 +1320,8 @@ nm_platform_ip6_route_hash_full (const NMPlatformIP6Route *obj)
 	return nm_platform_ip6_route_hash (obj, NM_PLATFORM_IP_ROUTE_CMP_TYPE_FULL);
 }
 
-gboolean nm_platform_check_support_kernel_extended_ifa_flags (NMPlatform *self);
-gboolean nm_platform_check_support_user_ipv6ll (NMPlatform *self);
+NMPlatformKernelSupportFlags nm_platform_check_kernel_support (NMPlatform *self,
+                                                               NMPlatformKernelSupportFlags request_flags);
 
 const char *nm_platform_link_flags2str (unsigned flags, char *buf, gsize len);
 const char *nm_platform_link_inet6_addrgenmode2str (guint8 mode, char *buf, gsize len);
diff --git a/src/platform/tests/test-link.c b/src/platform/tests/test-link.c
index 0a974eb13a..ccbada32d7 100644
--- a/src/platform/tests/test-link.c
+++ b/src/platform/tests/test-link.c
@@ -512,7 +512,8 @@ test_bridge_addr (void)
 	plink = nm_platform_link_get (NM_PLATFORM_GET, link.ifindex);
 	g_assert (plink);
 
-	if (nm_platform_check_support_user_ipv6ll (NM_PLATFORM_GET)) {
+	if (nm_platform_check_kernel_support (NM_PLATFORM_GET,
+	                                      NM_PLATFORM_KERNEL_SUPPORT_USER_IPV6LL)) {
 		g_assert (!nm_platform_link_get_user_ipv6ll_enabled (NM_PLATFORM_GET, link.ifindex));
 		g_assert_cmpint (_nm_platform_uint8_inv (plink->inet6_addr_gen_mode_inv), ==, NM_IN6_ADDR_GEN_MODE_EUI64);