+# The GNU/Linux filter flags.
+grep '^const _BPF_' gen-sysinfo.go | \
+ sed -e 's/^\(const \)_\(BPF_[^= ]*\)\(.*\)$/\1\2 = _\2/' >> ${OUT}
+
+# The GNU/Linux nlattr struct.
+grep '^type _nlattr ' gen-sysinfo.go | \
+ sed -e 's/_nlattr/NlAttr/' \
+ -e 's/nla_len/Len/' \
+ -e 's/nla_type/Type/' \
+ >> ${OUT}
+
+# The GNU/Linux nlmsgerr struct.
+grep '^type _nlmsgerr ' gen-sysinfo.go | \
+ sed -e 's/_nlmsgerr/NlMsgerr/' \
+ -e 's/error/Error/' \
+ -e 's/msg/Msg/' \
+ -e 's/_nlmsghdr/NlMsghdr/' \
+ >> ${OUT}
+
+# The GNU/Linux rtnexthop struct.
+grep '^type _rtnexthop ' gen-sysinfo.go | \
+ sed -e 's/_rtnexthop/RtNexthop/' \
+ -e 's/rtnh_len/Len/' \
+ -e 's/rtnh_flags/Flags/' \
+ -e 's/rtnh_hops/Hops/' \
+ -e 's/rtnh_ifindex/Ifindex/' \
+ >> ${OUT}
+
+# The GNU/Linux netlink flags.
+grep '^const _NETLINK_' gen-sysinfo.go | \
+ sed -e 's/^\(const \)_\(NETLINK_[^= ]*\)\(.*\)$/\1\2 = _\2/' >> ${OUT}
+grep '^const _NLA_' gen-sysinfo.go | \
+ sed -e 's/^\(const \)_\(NLA_[^= ]*\)\(.*\)$/\1\2 = _\2/' >> ${OUT}
+
+# The GNU/Linux packet socket flags.
+grep '^const _PACKET_' gen-sysinfo.go | \
+ sed -e 's/^\(const \)_\(PACKET_[^= ]*\)\(.*\)$/\1\2 = _\2/' >> ${OUT}
+
+# The GNU/Linux inotify_event struct.
+grep '^type _inotify_event ' gen-sysinfo.go | \
+ sed -e 's/_inotify_event/InotifyEvent/' \
+ -e 's/wd/Wd/' \
+ -e 's/mask/Mask/' \
+ -e 's/cookie/Cookie/' \
+ -e 's/len/Len/' \
+ -e 's/name/Name/' \
+ -e 's/\[\]/[0]/' \
+ -e 's/\[0\]byte/[0]int8/' \
+ >> ${OUT}
+
+# The GNU/Linux CLONE flags.
+grep '^const _CLONE_' gen-sysinfo.go | \
+ sed -e 's/^\(const \)_\(CLONE_[^= ]*\)\(.*\)$/\1\2 = _\2/' >> ${OUT}
+
+# Struct sizes.
+set cmsghdr Cmsghdr ip_mreq IPMreq ip_mreqn IPMreqn ipv6_mreq IPv6Mreq \
+ ifaddrmsg IfAddrmsg ifinfomsg IfInfomsg in_pktinfo Inet4Pktinfo \
+ in6_pktinfo Inet6Pktinfo inotify_event InotifyEvent linger Linger \
+ msghdr Msghdr nlattr NlAttr nlmsgerr NlMsgerr nlmsghdr NlMsghdr \
+ rtattr RtAttr rtgenmsg RtGenmsg rtmsg RtMsg rtnexthop RtNexthop \
+ sock_filter SockFilter sock_fprog SockFprog ucred Ucred \
+ icmp6_filter ICMPv6Filter
+while test $# != 0; do
+ nc=$1
+ ngo=$2
+ shift
+ shift
+ if grep "^const _sizeof_$nc =" gen-sysinfo.go >/dev/null 2>&1; then
+ echo "const Sizeof$ngo = _sizeof_$nc" >> ${OUT}
+ fi
+done
+
+# In order to compile the net package, we need some sizes to exist
+# even if the types do not.
+if ! grep 'const SizeofIPMreq ' ${OUT} >/dev/null 2>&1; then
+ echo 'const SizeofIPMreq = 8' >> ${OUT}
+fi
+if ! grep 'const SizeofIPv6Mreq ' ${OUT} >/dev/null 2>&1; then
+ echo 'const SizeofIPv6Mreq = 20' >> ${OUT}
+fi
+if ! grep 'const SizeofIPMreqn ' ${OUT} >/dev/null 2>&1; then
+ echo 'const SizeofIPMreqn = 12' >> ${OUT}
+fi
+if ! grep 'const SizeofICMPv6Filter ' ${OUT} >/dev/null 2>&1; then
+ echo 'const SizeofICMPv6Filter = 32' >> ${OUT}
+fi
+