From: Matthias Schiffer <mschiffer@universe-factory.net>
Date: Thu, 16 Jun 2016 00:51:07 +0200
Subject: linux: make IPv6 builtin if selected (saves >30KB)

Signed-off-by: Steven Barth <steven@midlink.org>

Backport of OpenWrt r46834

kmod-ipv6 is added to the PROVIDES of the kernel package, so we don't have
to adjust all packages depending on kmod-ipv6.

diff --git a/config/Config-build.in b/config/Config-build.in
index 4674d84..cd50290 100644
--- a/config/Config-build.in
+++ b/config/Config-build.in
@@ -83,7 +83,7 @@ menu "Global build settings"
 		prompt "Enable IPv6 support in packages"
 		default y
 		help
-		  Enable IPv6 support in packages (passes --enable-ipv6 to configure scripts).
+		  Enables IPv6 support in kernel (builtin) and packages.
 
 	config PKG_BUILD_PARALLEL
 		bool
diff --git a/package/kernel/linux/Makefile b/package/kernel/linux/Makefile
index 45ca9fa..b06c49a 100644
--- a/package/kernel/linux/Makefile
+++ b/package/kernel/linux/Makefile
@@ -49,6 +49,7 @@ define Package/kernel
   TITLE:=Virtual kernel package
   VERSION:=$(LINUX_VERSION)-$(LINUX_RELEASE)-$(LINUX_VERMAGIC)
   URL:=http://www.kernel.org/
+  PROVIDES:=$(if $(CONFIG_IPV6),kmod-ipv6)
 endef
 
 define Package/kernel/install
diff --git a/package/kernel/linux/modules/netsupport.mk b/package/kernel/linux/modules/netsupport.mk
index cea8e47..8a2760d 100644
--- a/package/kernel/linux/modules/netsupport.mk
+++ b/package/kernel/linux/modules/netsupport.mk
@@ -439,7 +439,7 @@ $(eval $(call KernelPackage,iptunnel4))
 define KernelPackage/iptunnel6
   SUBMENU:=$(NETWORK_SUPPORT_MENU)
   TITLE:=IPv6 tunneling
-  DEPENDS:= +kmod-ipv6
+  DEPENDS:=@IPV6
   KCONFIG:= \
 	CONFIG_INET6_TUNNEL
   FILES:=$(LINUX_DIR)/net/ipv6/tunnel6.ko
@@ -456,15 +456,16 @@ $(eval $(call KernelPackage,iptunnel6))
 define KernelPackage/ipv6
   SUBMENU:=$(NETWORK_SUPPORT_MENU)
   TITLE:=IPv6 support
+  DEPENDS:=@IPV6
+  HIDDEN:=1
+  DEFAULT:=y
   KCONFIG:= \
-	CONFIG_IPV6 \
+	CONFIG_IPV6=y \
 	CONFIG_IPV6_PRIVACY=y \
 	CONFIG_IPV6_MULTIPLE_TABLES=y \
 	CONFIG_IPV6_MROUTE=y \
 	CONFIG_IPV6_PIMSM_V2=n \
 	CONFIG_IPV6_SUBTREES=y
-  FILES:=$(LINUX_DIR)/net/ipv6/ipv6.ko
-  AUTOLOAD:=$(call AutoLoad,20,ipv6)
 endef
 
 define KernelPackage/ipv6/description
@@ -476,7 +477,7 @@ $(eval $(call KernelPackage,ipv6))
 
 define KernelPackage/sit
   SUBMENU:=$(NETWORK_SUPPORT_MENU)
-  DEPENDS:=+kmod-ipv6 +kmod-iptunnel +kmod-iptunnel4
+  DEPENDS:=@IPV6 +kmod-iptunnel +kmod-iptunnel4
   TITLE:=IPv6-in-IPv4 tunnel
   KCONFIG:=CONFIG_IPV6_SIT \
 	CONFIG_IPV6_SIT_6RD=y
@@ -494,7 +495,7 @@ $(eval $(call KernelPackage,sit))
 define KernelPackage/ip6-tunnel
   SUBMENU:=$(NETWORK_SUPPORT_MENU)
   TITLE:=IP-in-IPv6 tunnelling
-  DEPENDS:= +kmod-ipv6 +kmod-iptunnel6
+  DEPENDS:=@IPV6 +kmod-iptunnel6
   KCONFIG:= CONFIG_IPV6_TUNNEL
   FILES:=$(LINUX_DIR)/net/ipv6/ip6_tunnel.ko
   AUTOLOAD:=$(call AutoLoad,32,ip6_tunnel)
@@ -510,7 +511,7 @@ $(eval $(call KernelPackage,ip6-tunnel))
 define KernelPackage/gre
   SUBMENU:=$(NETWORK_SUPPORT_MENU)
   TITLE:=GRE support
-  DEPENDS:=+PACKAGE_kmod-ipv6:kmod-ipv6 +kmod-iptunnel
+  DEPENDS:=+kmod-iptunnel
   KCONFIG:=CONFIG_NET_IPGRE CONFIG_NET_IPGRE_DEMUX
   FILES:=$(LINUX_DIR)/net/ipv4/ip_gre.ko $(LINUX_DIR)/net/ipv4/gre.ko
   AUTOLOAD:=$(call AutoLoad,39,gre ip_gre)
@@ -526,7 +527,7 @@ $(eval $(call KernelPackage,gre))
 define KernelPackage/gre6
   SUBMENU:=$(NETWORK_SUPPORT_MENU)
   TITLE:=GRE support over IPV6
-  DEPENDS:=+kmod-ipv6 +kmod-iptunnel +kmod-ip6-tunnel
+  DEPENDS:=@IPV6 +kmod-iptunnel +kmod-ip6-tunnel
   KCONFIG:=CONFIG_IPV6_GRE
   FILES:=$(LINUX_DIR)/net/ipv6/ip6_gre.ko
   AUTOLOAD:=$(call AutoLoad,39,ip6_gre)
@@ -862,7 +863,6 @@ define KernelPackage/l2tp
   SUBMENU:=$(NETWORK_SUPPORT_MENU)
   TITLE:=Layer Two Tunneling Protocol (L2TP)
   DEPENDS:= \
-	+IPV6:kmod-ipv6 \
 	+kmod-udptunnel4 \
 	+IPV6:kmod-udptunnel6
   KCONFIG:=CONFIG_L2TP \
@@ -898,7 +898,7 @@ $(eval $(call KernelPackage,l2tp-eth))
 define KernelPackage/l2tp-ip
   SUBMENU:=$(NETWORK_SUPPORT_MENU)
   TITLE:=L2TP IP encapsulation for L2TPv3
-  DEPENDS:=+kmod-l2tp +IPV6:kmod-ipv6
+  DEPENDS:=+kmod-l2tp
   KCONFIG:=CONFIG_L2TP_IP
   FILES:= \
 	$(LINUX_DIR)/net/l2tp/l2tp_ip.ko \
@@ -930,7 +930,7 @@ define KernelPackage/sctp
      CONFIG_SCTP_DEFAULT_COOKIE_HMAC_MD5=y
   FILES:= $(LINUX_DIR)/net/sctp/sctp.ko
   AUTOLOAD:= $(call AutoLoad,32,sctp)
-  DEPENDS:=+kmod-lib-crc32c +kmod-crypto-md5 +kmod-crypto-hmac +IPV6:kmod-ipv6
+  DEPENDS:=+kmod-lib-crc32c +kmod-crypto-md5 +kmod-crypto-hmac
 endef
 
 define KernelPackage/sctp/description
diff --git a/package/network/services/dnsmasq/Makefile b/package/network/services/dnsmasq/Makefile
index 19a8df9..8fd51fe 100644
--- a/package/network/services/dnsmasq/Makefile
+++ b/package/network/services/dnsmasq/Makefile
@@ -52,7 +52,6 @@ define Package/dnsmasq-full
 $(call Package/dnsmasq/Default)
   TITLE += (with DNSSEC, DHCPv6, Auth DNS, IPset enabled by default)
   DEPENDS:=+PACKAGE_dnsmasq_full_dnssec:libnettle \
-	+PACKAGE_dnsmasq_full_dhcpv6:kmod-ipv6 \
 	+PACKAGE_dnsmasq_full_ipset:kmod-ipt-ipset
   VARIANT:=full
 endef