+dnl the directory in $KBUILD.
+AC_DEFUN([OVS_CHECK_LINUX_COMPAT], [
+ rm -f datapath/linux/kcompat.h.new
+ mkdir -p datapath/linux
+ : > datapath/linux/kcompat.h.new
+
+ echo '#include <linux/version.h>
+#ifndef RHEL_RELEASE_CODE
+#define RHEL_RELEASE_CODE 0
+#define RHEL_RELEASE_VERSION(a, b) 0
+#endif' >> datapath/linux/kcompat.h.new
+
+ OVS_GREP_IFELSE([$KSRC/arch/x86/include/asm/checksum_32.h], [src_err,],
+ [OVS_DEFINE([HAVE_CSUM_COPY_DBG])])
+
+ OVS_GREP_IFELSE([$KSRC/include/net/addrconf.h], [ipv6_dst_lookup.*net],
+ [OVS_DEFINE([HAVE_IPV6_DST_LOOKUP_NET])])
+ OVS_GREP_IFELSE([$KSRC/include/net/addrconf.h], [ipv6_stub])
+
+ OVS_GREP_IFELSE([$KSRC/include/linux/err.h], [ERR_CAST])
+ OVS_GREP_IFELSE([$KSRC/include/linux/err.h], [IS_ERR_OR_NULL])
+
+ OVS_GREP_IFELSE([$KSRC/include/linux/etherdevice.h], [eth_hw_addr_random])
+ OVS_GREP_IFELSE([$KSRC/include/linux/etherdevice.h], [ether_addr_copy])
+
+ OVS_GREP_IFELSE([$KSRC/include/uapi/linux/if_link.h], [IFLA_GENEVE_TOS])
+ OVS_GREP_IFELSE([$KSRC/include/uapi/linux/if_link.h], [rtnl_link_stats64])
+ OVS_GREP_IFELSE([$KSRC/include/linux/if_link.h], [rtnl_link_stats64])
+ OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [vlan_set_encap_proto])
+ OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [vlan_hwaccel_push_inside])
+
+ OVS_GREP_IFELSE([$KSRC/include/linux/in.h], [ipv4_is_multicast])
+ OVS_GREP_IFELSE([$KSRC/include/linux/in.h], [proto_ports_offset])
+ OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [__ip_select_ident.*dst_entry],
+ [OVS_DEFINE([HAVE_IP_SELECT_IDENT_USING_DST_ENTRY])])
+ OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [__ip_select_ident.*net],
+ [OVS_DEFINE([HAVE_IP_SELECT_IDENT_USING_NET])])
+
+ OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [inet_get_local_port_range.*net],
+ [OVS_DEFINE([HAVE_INET_GET_LOCAL_PORT_RANGE_USING_NET])])
+ OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [ip_do_fragment])
+ OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [ip_is_fragment])
+ OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [ip_skb_dst_mtu])
+
+ OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [IPSKB_FRAG_PMTU],
+ [OVS_DEFINE([HAVE_CORRECT_MRU_HANDLING])])
+ OVS_GREP_IFELSE([$KSRC/include/net/ip_tunnels.h], [__ip_tunnel_change_mtu])
+ OVS_GREP_IFELSE([$KSRC/include/net/inet_frag.h], [hashfn.*const],
+ [OVS_DEFINE([HAVE_INET_FRAGS_CONST])])
+ OVS_GREP_IFELSE([$KSRC/include/net/inet_frag.h], [last_in],
+ [OVS_DEFINE([HAVE_INET_FRAGS_LAST_IN])])
+ OVS_GREP_IFELSE([$KSRC/include/net/inet_frag.h], [inet_frag_evicting])
+ OVS_FIND_FIELD_IFELSE([$KSRC/include/net/inet_frag.h], [inet_frags],
+ [frags_work])
+ OVS_FIND_FIELD_IFELSE([$KSRC/include/net/inet_frag.h], [inet_frags],
+ [rwlock])
+ OVS_FIND_FIELD_IFELSE([$KSRC/include/net/inet_frag.h], [inet_frag_queue],
+ [list_evictor])
+ OVS_GREP_IFELSE([$KSRC/include/net/inetpeer.h], [vif],
+ [OVS_DEFINE([HAVE_INETPEER_VIF_SUPPORT])])
+
+ OVS_GREP_IFELSE([$KSRC/include/net/dst_metadata.h], [metadata_dst])
+
+ OVS_GREP_IFELSE([$KSRC/include/linux/net.h], [sock_create_kern.*net],
+ [OVS_DEFINE([HAVE_SOCK_CREATE_KERN_NET])])
+ OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [dev_disable_lro])
+ OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [dev_get_stats])
+ OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [dev_get_by_index_rcu])
+ OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [dev_recursion_level])
+ OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [__skb_gso_segment])
+ OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [can_checksum_protocol])
+ OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [ndo_get_iflink])
+ OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [netdev_features_t])
+ OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [pcpu_sw_netstats])
+ OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [netdev_rx_handler_register])
+ OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [net_device_extended])
+ OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [rx_handler_func_t.*pskb],
+ [OVS_DEFINE([HAVE_RX_HANDLER_PSKB])])
+ OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [netif_needs_gso.*net_device],
+ [OVS_DEFINE([HAVE_NETIF_NEEDS_GSO_NETDEV])])
+ OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [udp_offload])
+ OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [udp_offload.*uoff],
+ [OVS_DEFINE([HAVE_UDP_OFFLOAD_ARG_UOFF])])
+ OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [gro_remcsum])
+
+ OVS_GREP_IFELSE([$KSRC/include/linux/netfilter.h], [nf_hook_state])
+ OVS_GREP_IFELSE([$KSRC/include/linux/netfilter.h], [nf_register_net_hook])
+ OVS_GREP_IFELSE([$KSRC/include/linux/netfilter.h], [nf_hookfn.*nf_hook_ops],
+ [OVS_DEFINE([HAVE_NF_HOOKFN_ARG_OPS])])
+ OVS_FIND_FIELD_IFELSE([$KSRC/include/linux/netfilter_ipv6.h], [nf_ipv6_ops],
+ [fragment], [OVS_DEFINE([HAVE_NF_IPV6_OPS_FRAGMENT])])
+
+ OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_conntrack.h],
+ [tmpl_alloc.*conntrack_zone],
+ [OVS_DEFINE([HAVE_NF_CT_TMPL_ALLOC_TAKES_STRUCT_ZONE])])
+ OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_conntrack_zones.h],
+ [nf_ct_zone_init])
+ OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_conntrack_labels.h],
+ [nf_connlabels_get])
+ OVS_GREP_IFELSE([$KSRC/include/net/netfilter/ipv6/nf_defrag_ipv6.h],
+ [nf_ct_frag6_consume_orig])
+ OVS_GREP_IFELSE([$KSRC/include/net/netfilter/ipv6/nf_defrag_ipv6.h],
+ [nf_ct_frag6_output])
+
+ OVS_GREP_IFELSE([$KSRC/include/linux/random.h], [prandom_u32])
+ OVS_GREP_IFELSE([$KSRC/include/linux/random.h], [prandom_u32_max])
+
+ OVS_GREP_IFELSE([$KSRC/include/net/rtnetlink.h], [get_link_net])
+ OVS_GREP_IFELSE([$KSRC/include/net/rtnetlink.h], [name_assign_type])
+ OVS_GREP_IFELSE([$KSRC/include/net/rtnetlink.h], [rtnl_create_link.*src_net],
+ [OVS_DEFINE([HAVE_RTNL_CREATE_LINK_SRC_NET])])
+ OVS_GREP_IFELSE([$KSRC/include/net/net_namespace.h], [possible_net_t])
+
+ OVS_GREP_IFELSE([$KSRC/include/linux/rcupdate.h], [rcu_read_lock_held], [],
+ [OVS_GREP_IFELSE([$KSRC/include/linux/rtnetlink.h],
+ [rcu_read_lock_held])])
+ OVS_GREP_IFELSE([$KSRC/include/linux/rtnetlink.h], [lockdep_rtnl_is_held])
+
+ # Check for the proto_data_valid member in struct sk_buff. The [^@]
+ # is necessary because some versions of this header remove the
+ # member but retain the kerneldoc comment that describes it (which
+ # starts with @). The brackets must be doubled because of m4
+ # quoting rules.
+ OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [[[^@]]proto_data_valid],
+ [OVS_DEFINE([HAVE_PROTO_DATA_VALID])])
+ OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_checksum_start_offset])
+ OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [inner_protocol])
+ OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [inner_mac_header])
+ OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [inner_network_header])
+ OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [kfree_skb_list])
+ OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_scrub_packet.*xnet],
+ [OVS_DEFINE([HAVE_SKB_SCRUB_PACKET_XNET])])
+ OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [rxhash])
+ OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [u16.*rxhash],
+ [OVS_DEFINE([HAVE_U16_RXHASH])])
+ OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_dst(],
+ [OVS_DEFINE([HAVE_SKB_DST_ACCESSOR_FUNCS])])
+ OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h],
+ [skb_copy_from_linear_data_offset])
+ OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h],
+ [skb_reset_tail_pointer])
+ OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_cow_head])
+ OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_transport_header],