From 0768b3b3d228c5acf2075f40f3d25cda30011d4f Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Wed, 19 Feb 2014 17:27:06 +0100 Subject: netfilter: nf_tables: add optional user data area to rules This allows us to store user comment strings, but it could be also used to store any kind of information that the user application needs to link to the rule. Scratch 8 bits for the new ulen field that indicates the length the user data area. 4 bits from the handle (so it's 42 bits long, according to Patrick, it would last 139 years with 1000 new rules per second) and 4 bits from dlen (so the expression data area is 4K, which seems sufficient by now even considering the compatibility layer). Signed-off-by: Pablo Neira Ayuso Acked-by: Patrick McHardy --- include/uapi/linux/netfilter/nf_tables.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/uapi') diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index c84c452c62a7..c88ccbfda5f1 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -1,7 +1,8 @@ #ifndef _LINUX_NF_TABLES_H #define _LINUX_NF_TABLES_H -#define NFT_CHAIN_MAXNAMELEN 32 +#define NFT_CHAIN_MAXNAMELEN 32 +#define NFT_USERDATA_MAXLEN 256 enum nft_registers { NFT_REG_VERDICT, @@ -156,6 +157,7 @@ enum nft_chain_attributes { * @NFTA_RULE_EXPRESSIONS: list of expressions (NLA_NESTED: nft_expr_attributes) * @NFTA_RULE_COMPAT: compatibility specifications of the rule (NLA_NESTED: nft_rule_compat_attributes) * @NFTA_RULE_POSITION: numeric handle of the previous rule (NLA_U64) + * @NFTA_RULE_USERDATA: user data (NLA_BINARY, NFT_USERDATA_MAXLEN) */ enum nft_rule_attributes { NFTA_RULE_UNSPEC, @@ -165,6 +167,7 @@ enum nft_rule_attributes { NFTA_RULE_EXPRESSIONS, NFTA_RULE_COMPAT, NFTA_RULE_POSITION, + NFTA_RULE_USERDATA, __NFTA_RULE_MAX }; #define NFTA_RULE_MAX (__NFTA_RULE_MAX - 1) -- cgit v1.2.3