diff --git a/pkg/abi/linux/BUILD b/pkg/abi/linux/BUILD index 141896951..b34f6fe9e 100644 --- a/pkg/abi/linux/BUILD +++ b/pkg/abi/linux/BUILD @@ -57,6 +57,7 @@ go_library( "netfilter_ipv6.go", "netlink.go", "netlink_route.go", + "nf_tables.go", "poll.go", "prctl.go", "ptrace.go", diff --git a/pkg/abi/linux/nf_tables.go b/pkg/abi/linux/nf_tables.go new file mode 100644 index 000000000..6a005aba3 --- /dev/null +++ b/pkg/abi/linux/nf_tables.go @@ -0,0 +1,82 @@ +// Copyright 2024 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package linux + +// This file contains constants required to support nf_tables. + +// 16-byte Registers that can be used to maintain state for rules. +// These correspond to values in include/uapi/linux/netfilter/nf_tables.h. +const ( + NFT_REG_VERDICT = iota + NFT_REG_1 + NFT_REG_2 + NFT_REG_3 + NFT_REG_4 + __NFT_REG_MAX +) + +// 4-byte Registers that can be used to maintain state for rules. +// Note that these overlap with the 16-byte registers in memory. +// These correspond to values in include/uapi/linux/netfilter/nf_tables.h. +const ( + NFT_REG32_00 = 8 + iota + NFT_REG32_01 + NFT_REG32_02 + NFT_REG32_03 + NFT_REG32_04 + NFT_REG32_05 + NFT_REG32_06 + NFT_REG32_07 + NFT_REG32_08 + NFT_REG32_09 + NFT_REG32_10 + NFT_REG32_11 + NFT_REG32_12 + NFT_REG32_13 + NFT_REG32_14 + NFT_REG32_15 +) + +// Other register constants, corresponding to values in +// include/uapi/linux/netfilter/nf_tables.h. +const ( + NFT_REG_MAX = __NFT_REG_MAX - 1 // Maximum register value + NFT_REG_SIZE = 16 // Size of NFT_REG + NFT_REG32_SIZE = 4 // Size of NFT_REG32 + NFT_REG32_COUNT = NFT_REG32_15 - NFT_REG32_00 + 1 // Count of 4-byte registers +) + +// Internal nf table verdicts. These are used for ruleset evaluation and +// are not returned to userspace. +// +// These also share their numeric name space with the netfilter verdicts. When +// used these values are converted to uint32 (purposefully overflowing the int). +// These correspond to values in include/uapi/linux/netfilter/nf_tables.h. +const ( + // Continue evaluation of the current rule. + NFT_CONTINUE int32 = -1 + + // Terminate evaluation of the current rule. + NFT_BREAK = -2 + + // Push the current chain on the jump stack and jump to a chain. + NFT_JUMP = -3 + + // Jump to a chain without pushing the current chain on the jump stack. + NFT_GOTO = -4 + + // Return to the topmost chain on the jump stack. + NFT_RETURN = -5 +)