From 772892a018b4431361a226020b0f7615ab2b304f Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Mon, 2 Jan 2023 15:36:25 +0100 Subject: src: add vxlan matching support This patch adds the initial infrastructure to support for inner header tunnel matching and its first user: vxlan. A new struct proto_desc field for payload and meta expression to specify that the expression refers to inner header matching is used. The existing codebase to generate bytecode is fully reused, allowing for reusing existing supported layer 2, 3 and 4 protocols. Syntax requires to specify vxlan before the inner protocol field: ... vxlan ip protocol udp ... vxlan ip saddr 1.2.3.0/24 This also works with concatenations and anonymous sets, eg. ... vxlan ip saddr . vxlan ip daddr { 1.2.3.4 . 4.3.2.1 } You have to restrict vxlan matching to udp traffic, otherwise it complains on missing transport protocol dependency, e.g. ... udp dport 4789 vxlan ip daddr 1.2.3.4 The bytecode that is generated uses the new inner expression: # nft --debug=netlink add rule netdev x y udp dport 4789 vxlan ip saddr 1.2.3.4 netdev x y [ meta load l4proto => reg 1 ] [ cmp eq reg 1 0x00000011 ] [ payload load 2b @ transport header + 2 => reg 1 ] [ cmp eq reg 1 0x0000b512 ] [ inner type 1 hdrsize 8 flags f [ meta load protocol => reg 1 ] ] [ cmp eq reg 1 0x00000008 ] [ inner type 1 hdrsize 8 flags f [ payload load 4b @ network header + 12 => reg 1 ] ] [ cmp eq reg 1 0x04030201 ] JSON support is not included in this patch. Signed-off-by: Pablo Neira Ayuso --- include/expression.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/expression.h') diff --git a/include/expression.h b/include/expression.h index 3f06a38a..1f58a68c 100644 --- a/include/expression.h +++ b/include/expression.h @@ -316,6 +316,7 @@ struct expr { /* EXPR_PAYLOAD */ const struct proto_desc *desc; const struct proto_hdr_template *tmpl; + const struct proto_desc *inner_desc; enum proto_bases base; unsigned int offset; bool is_raw; @@ -334,6 +335,7 @@ struct expr { /* EXPR_META */ enum nft_meta_keys key; enum proto_bases base; + const struct proto_desc *inner_desc; } meta; struct { /* SOCKET */ -- cgit v1.2.3