From 14bb08c1df8db9ec6c8a05520d4eee67971235d9 Mon Sep 17 00:00:00 2001 From: Dimitri Sokolyuk Date: Thu, 27 Sep 2018 20:03:23 +0200 Subject: mod tidy --- vendor/golang.org/x/net/bpf/vm.go | 140 -------------------------------------- 1 file changed, 140 deletions(-) delete mode 100644 vendor/golang.org/x/net/bpf/vm.go (limited to 'vendor/golang.org/x/net/bpf/vm.go') diff --git a/vendor/golang.org/x/net/bpf/vm.go b/vendor/golang.org/x/net/bpf/vm.go deleted file mode 100644 index 4c656f1..0000000 --- a/vendor/golang.org/x/net/bpf/vm.go +++ /dev/null @@ -1,140 +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 ( - "errors" - "fmt" -) - -// A VM is an emulated BPF virtual machine. -type VM struct { - filter []Instruction -} - -// NewVM returns a new VM using the input BPF program. -func NewVM(filter []Instruction) (*VM, error) { - if len(filter) == 0 { - return nil, errors.New("one or more Instructions must be specified") - } - - for i, ins := range filter { - check := len(filter) - (i + 1) - switch ins := ins.(type) { - // Check for out-of-bounds jumps in instructions - case Jump: - if check <= int(ins.Skip) { - return nil, fmt.Errorf("cannot jump %d instructions; jumping past program bounds", ins.Skip) - } - case JumpIf: - if check <= int(ins.SkipTrue) { - return nil, fmt.Errorf("cannot jump %d instructions in true case; jumping past program bounds", ins.SkipTrue) - } - if check <= int(ins.SkipFalse) { - return nil, fmt.Errorf("cannot jump %d instructions in false case; jumping past program bounds", ins.SkipFalse) - } - // Check for division or modulus by zero - case ALUOpConstant: - if ins.Val != 0 { - break - } - - switch ins.Op { - case ALUOpDiv, ALUOpMod: - return nil, errors.New("cannot divide by zero using ALUOpConstant") - } - // Check for unknown extensions - case LoadExtension: - switch ins.Num { - case ExtLen: - default: - return nil, fmt.Errorf("extension %d not implemented", ins.Num) - } - } - } - - // Make sure last instruction is a return instruction - switch filter[len(filter)-1].(type) { - case RetA, RetConstant: - default: - return nil, errors.New("BPF program must end with RetA or RetConstant") - } - - // Though our VM works using disassembled instructions, we - // attempt to assemble the input filter anyway to ensure it is compatible - // with an operating system VM. - _, err := Assemble(filter) - - return &VM{ - filter: filter, - }, err -} - -// Run runs the VM's BPF program against the input bytes. -// Run returns the number of bytes accepted by the BPF program, and any errors -// which occurred while processing the program. -func (v *VM) Run(in []byte) (int, error) { - var ( - // Registers of the virtual machine - regA uint32 - regX uint32 - regScratch [16]uint32 - - // OK is true if the program should continue processing the next - // instruction, or false if not, causing the loop to break - ok = true - ) - - // TODO(mdlayher): implement: - // - NegateA: - // - would require a change from uint32 registers to int32 - // registers - - // TODO(mdlayher): add interop tests that check signedness of ALU - // operations against kernel implementation, and make sure Go - // implementation matches behavior - - for i := 0; i < len(v.filter) && ok; i++ { - ins := v.filter[i] - - switch ins := ins.(type) { - case ALUOpConstant: - regA = aluOpConstant(ins, regA) - case ALUOpX: - regA, ok = aluOpX(ins, regA, regX) - case Jump: - i += int(ins.Skip) - case JumpIf: - jump := jumpIf(ins, regA) - i += jump - case LoadAbsolute: - regA, ok = loadAbsolute(ins, in) - case LoadConstant: - regA, regX = loadConstant(ins, regA, regX) - case LoadExtension: - regA = loadExtension(ins, in) - case LoadIndirect: - regA, ok = loadIndirect(ins, in, regX) - case LoadMemShift: - regX, ok = loadMemShift(ins, in) - case LoadScratch: - regA, regX = loadScratch(ins, regScratch, regA, regX) - case RetA: - return int(regA), nil - case RetConstant: - return int(ins.Val), nil - case StoreScratch: - regScratch = storeScratch(ins, regScratch, regA, regX) - case TAX: - regX = regA - case TXA: - regA = regX - default: - return 0, fmt.Errorf("unknown Instruction at index %d: %T", i, ins) - } - } - - return 0, nil -} -- cgit v1.2.3