summaryrefslogtreecommitdiff
path: root/vendor/golang.org/x/net/bpf/vm_instructions.go
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/golang.org/x/net/bpf/vm_instructions.go')
-rw-r--r--vendor/golang.org/x/net/bpf/vm_instructions.go174
1 files changed, 0 insertions, 174 deletions
diff --git a/vendor/golang.org/x/net/bpf/vm_instructions.go b/vendor/golang.org/x/net/bpf/vm_instructions.go
deleted file mode 100644
index 516f946..0000000
--- a/vendor/golang.org/x/net/bpf/vm_instructions.go
+++ /dev/null
@@ -1,174 +0,0 @@
-// Copyright 2016 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package bpf
-
-import (
- "encoding/binary"
- "fmt"
-)
-
-func aluOpConstant(ins ALUOpConstant, regA uint32) uint32 {
- return aluOpCommon(ins.Op, regA, ins.Val)
-}
-
-func aluOpX(ins ALUOpX, regA uint32, regX uint32) (uint32, bool) {
- // Guard against division or modulus by zero by terminating
- // the program, as the OS BPF VM does
- if regX == 0 {
- switch ins.Op {
- case ALUOpDiv, ALUOpMod:
- return 0, false
- }
- }
-
- return aluOpCommon(ins.Op, regA, regX), true
-}
-
-func aluOpCommon(op ALUOp, regA uint32, value uint32) uint32 {
- switch op {
- case ALUOpAdd:
- return regA + value
- case ALUOpSub:
- return regA - value
- case ALUOpMul:
- return regA * value
- case ALUOpDiv:
- // Division by zero not permitted by NewVM and aluOpX checks
- return regA / value
- case ALUOpOr:
- return regA | value
- case ALUOpAnd:
- return regA & value
- case ALUOpShiftLeft:
- return regA << value
- case ALUOpShiftRight:
- return regA >> value
- case ALUOpMod:
- // Modulus by zero not permitted by NewVM and aluOpX checks
- return regA % value
- case ALUOpXor:
- return regA ^ value
- default:
- return regA
- }
-}
-
-func jumpIf(ins JumpIf, value uint32) int {
- var ok bool
- inV := uint32(ins.Val)
-
- switch ins.Cond {
- case JumpEqual:
- ok = value == inV
- case JumpNotEqual:
- ok = value != inV
- case JumpGreaterThan:
- ok = value > inV
- case JumpLessThan:
- ok = value < inV
- case JumpGreaterOrEqual:
- ok = value >= inV
- case JumpLessOrEqual:
- ok = value <= inV
- case JumpBitsSet:
- ok = (value & inV) != 0
- case JumpBitsNotSet:
- ok = (value & inV) == 0
- }
-
- if ok {
- return int(ins.SkipTrue)
- }
-
- return int(ins.SkipFalse)
-}
-
-func loadAbsolute(ins LoadAbsolute, in []byte) (uint32, bool) {
- offset := int(ins.Off)
- size := int(ins.Size)
-
- return loadCommon(in, offset, size)
-}
-
-func loadConstant(ins LoadConstant, regA uint32, regX uint32) (uint32, uint32) {
- switch ins.Dst {
- case RegA:
- regA = ins.Val
- case RegX:
- regX = ins.Val
- }
-
- return regA, regX
-}
-
-func loadExtension(ins LoadExtension, in []byte) uint32 {
- switch ins.Num {
- case ExtLen:
- return uint32(len(in))
- default:
- panic(fmt.Sprintf("unimplemented extension: %d", ins.Num))
- }
-}
-
-func loadIndirect(ins LoadIndirect, in []byte, regX uint32) (uint32, bool) {
- offset := int(ins.Off) + int(regX)
- size := int(ins.Size)
-
- return loadCommon(in, offset, size)
-}
-
-func loadMemShift(ins LoadMemShift, in []byte) (uint32, bool) {
- offset := int(ins.Off)
-
- if !inBounds(len(in), offset, 0) {
- return 0, false
- }
-
- // Mask off high 4 bits and multiply low 4 bits by 4
- return uint32(in[offset]&0x0f) * 4, true
-}
-
-func inBounds(inLen int, offset int, size int) bool {
- return offset+size <= inLen
-}
-
-func loadCommon(in []byte, offset int, size int) (uint32, bool) {
- if !inBounds(len(in), offset, size) {
- return 0, false
- }
-
- switch size {
- case 1:
- return uint32(in[offset]), true
- case 2:
- return uint32(binary.BigEndian.Uint16(in[offset : offset+size])), true
- case 4:
- return uint32(binary.BigEndian.Uint32(in[offset : offset+size])), true
- default:
- panic(fmt.Sprintf("invalid load size: %d", size))
- }
-}
-
-func loadScratch(ins LoadScratch, regScratch [16]uint32, regA uint32, regX uint32) (uint32, uint32) {
- switch ins.Dst {
- case RegA:
- regA = regScratch[ins.N]
- case RegX:
- regX = regScratch[ins.N]
- }
-
- return regA, regX
-}
-
-func storeScratch(ins StoreScratch, regScratch [16]uint32, regA uint32, regX uint32) [16]uint32 {
- switch ins.Src {
- case RegA:
- regScratch[ins.N] = regA
- case RegX:
- regScratch[ins.N] = regX
- }
-
- return regScratch
-}