From b2591d4b13ab95240216a93d682b842c28b2b884 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 3 Dec 2021 20:19:10 +0100 Subject: netlink_delinearize: zero shift removal Remove shifts-by-0. These can occur after binop postprocessing has adjusted the RHS value to account for a mask operation. Example: frag frag-off @s4 Is internally represented via: [ exthdr load ipv6 2b @ 44 + 2 => reg 1 ] [ bitwise reg 1 = ( reg 1 & 0x0000f8ff ) ^ 0x00000000 ] [ bitwise reg 1 = ( reg 1 >> 0x00000003 ) ] [ lookup reg 1 set s ] First binop masks out unwanted parts of the 16-bit field. Second binop needs to left-shift so that lookups in the set will work. When decoding, the first binop is removed after the exthdr load has been adjusted accordingly. Constant propagation adjusts the shift-value to 0 on removal. This change then gets rid of the shift-by-0 entirely. After this change, 'frag frag-off @s4' input is shown as-is. Signed-off-by: Florian Westphal --- tests/shell/testcases/sets/dumps/typeof_sets_0.nft | 8 ++++++++ tests/shell/testcases/sets/typeof_sets_0 | 8 ++++++++ 2 files changed, 16 insertions(+) (limited to 'tests/shell/testcases') diff --git a/tests/shell/testcases/sets/dumps/typeof_sets_0.nft b/tests/shell/testcases/sets/dumps/typeof_sets_0.nft index ad442713..e397a634 100644 --- a/tests/shell/testcases/sets/dumps/typeof_sets_0.nft +++ b/tests/shell/testcases/sets/dumps/typeof_sets_0.nft @@ -53,6 +53,10 @@ table inet t { vlan id @s2 accept } + chain c4 { + frag frag-off @s4 accept + } + chain c5 { ip option ra value @s5 accept } @@ -65,6 +69,10 @@ table inet t { sctp chunk init num-inbound-streams @s7 accept } + chain c8 { + ip version @s8 accept + } + chain c9 { ip hdrlength @s9 accept } diff --git a/tests/shell/testcases/sets/typeof_sets_0 b/tests/shell/testcases/sets/typeof_sets_0 index 2102789e..be906cdc 100755 --- a/tests/shell/testcases/sets/typeof_sets_0 +++ b/tests/shell/testcases/sets/typeof_sets_0 @@ -58,6 +58,10 @@ EXPECTED="table inet t { ether type vlan vlan id @s2 accept } + chain c4 { + frag frag-off @s4 accept + } + chain c5 { ip option ra value @s5 accept } @@ -70,6 +74,10 @@ EXPECTED="table inet t { sctp chunk init num-inbound-streams @s7 accept } + chain c8 { + ip version @s8 accept + } + chain c9 { ip hdrlength @s9 accept } -- cgit v1.2.3