netfilter: nft_reject: introduce icmp code abstraction for inet and bridge
This patch introduces the NFT_REJECT_ICMPX_UNREACH type which provides
an abstraction to the ICMP and ICMPv6 codes that you can use from the
inet and bridge tables, they are:
* NFT_REJECT_ICMPX_NO_ROUTE: no route to host - network unreachable
* NFT_REJECT_ICMPX_PORT_UNREACH: port unreachable
* NFT_REJECT_ICMPX_HOST_UNREACH: host unreachable
* NFT_REJECT_ICMPX_ADMIN_PROHIBITED: administratevely prohibited
You can still use the specific codes when restricting the rule to match
the corresponding layer 3 protocol.
I decided to not overload the existing NFT_REJECT_ICMP_UNREACH to have
different semantics depending on the table family and to allow the user
to specify ICMP family specific codes if they restrict it to the
corresponding family.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index b72ccfe..c26df67 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -749,13 +749,34 @@
*
* @NFT_REJECT_ICMP_UNREACH: reject using ICMP unreachable
* @NFT_REJECT_TCP_RST: reject using TCP RST
+ * @NFT_REJECT_ICMPX_UNREACH: abstracted ICMP unreachable for bridge and inet
*/
enum nft_reject_types {
NFT_REJECT_ICMP_UNREACH,
NFT_REJECT_TCP_RST,
+ NFT_REJECT_ICMPX_UNREACH,
};
/**
+ * enum nft_reject_code - Generic reject codes for IPv4/IPv6
+ *
+ * @NFT_REJECT_ICMPX_NO_ROUTE: no route to host / network unreachable
+ * @NFT_REJECT_ICMPX_PORT_UNREACH: port unreachable
+ * @NFT_REJECT_ICMPX_HOST_UNREACH: host unreachable
+ * @NFT_REJECT_ICMPX_ADMIN_PROHIBITED: administratively prohibited
+ *
+ * These codes are mapped to real ICMP and ICMPv6 codes.
+ */
+enum nft_reject_inet_code {
+ NFT_REJECT_ICMPX_NO_ROUTE = 0,
+ NFT_REJECT_ICMPX_PORT_UNREACH,
+ NFT_REJECT_ICMPX_HOST_UNREACH,
+ NFT_REJECT_ICMPX_ADMIN_PROHIBITED,
+ __NFT_REJECT_ICMPX_MAX
+};
+#define NFT_REJECT_ICMPX_MAX (__NFT_REJECT_ICMPX_MAX + 1)
+
+/**
* enum nft_reject_attributes - nf_tables reject expression netlink attributes
*
* @NFTA_REJECT_TYPE: packet type to use (NLA_U32: nft_reject_types)