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| author | Pablo Neira Ayuso <pablo@netfilter.org> | 2016-11-24 14:04:55 +0300 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2016-12-06 23:47:54 +0300 |
| commit | 1814096980bbe546c4384b7b064126cbe7d40d30 (patch) | |
| tree | 60b487a40c3af0f581b97928d508ade027d8cdb0 /include | |
| parent | e0ffdbc78d84e1da090f03ab62da3def0e65159e (diff) | |
| download | linux-1814096980bbe546c4384b7b064126cbe7d40d30.tar.xz | |
netfilter: nft_payload: layer 4 checksum adjustment for pseudoheader fields
This patch adds a new flag that signals the kernel to update layer 4
checksum if the packet field belongs to the layer 4 pseudoheader. This
implicitly provides stateless NAT 1:1 that is useful under very specific
usecases.
Since rules mangling layer 3 fields that are part of the pseudoheader
may potentially convey any layer 4 packet, we have to deal with the
layer 4 checksum adjustment using protocol specific code.
This patch adds support for TCP, UDP and ICMPv6, since they include the
pseudoheader in the layer 4 checksum calculation. ICMP doesn't, so we
can skip it.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/netfilter/nf_tables_core.h | 1 | ||||
| -rw-r--r-- | include/uapi/linux/netfilter/nf_tables.h | 6 |
2 files changed, 7 insertions, 0 deletions
diff --git a/include/net/netfilter/nf_tables_core.h b/include/net/netfilter/nf_tables_core.h index 862373d4ea9d..8f690effec37 100644 --- a/include/net/netfilter/nf_tables_core.h +++ b/include/net/netfilter/nf_tables_core.h @@ -45,6 +45,7 @@ struct nft_payload_set { enum nft_registers sreg:8; u8 csum_type; u8 csum_offset; + u8 csum_flags; }; extern const struct nft_expr_ops nft_payload_fast_ops; diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index 14e5f619167e..f030e59aa2ec 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -659,6 +659,10 @@ enum nft_payload_csum_types { NFT_PAYLOAD_CSUM_INET, }; +enum nft_payload_csum_flags { + NFT_PAYLOAD_L4CSUM_PSEUDOHDR = (1 << 0), +}; + /** * enum nft_payload_attributes - nf_tables payload expression netlink attributes * @@ -669,6 +673,7 @@ enum nft_payload_csum_types { * @NFTA_PAYLOAD_SREG: source register to load data from (NLA_U32: nft_registers) * @NFTA_PAYLOAD_CSUM_TYPE: checksum type (NLA_U32) * @NFTA_PAYLOAD_CSUM_OFFSET: checksum offset relative to base (NLA_U32) + * @NFTA_PAYLOAD_CSUM_FLAGS: checksum flags (NLA_U32) */ enum nft_payload_attributes { NFTA_PAYLOAD_UNSPEC, @@ -679,6 +684,7 @@ enum nft_payload_attributes { NFTA_PAYLOAD_SREG, NFTA_PAYLOAD_CSUM_TYPE, NFTA_PAYLOAD_CSUM_OFFSET, + NFTA_PAYLOAD_CSUM_FLAGS, __NFTA_PAYLOAD_MAX }; #define NFTA_PAYLOAD_MAX (__NFTA_PAYLOAD_MAX - 1) |