diff options
Diffstat (limited to 'vendor/golang.org/x/net/bpf/instructions.go')
| -rw-r--r-- | vendor/golang.org/x/net/bpf/instructions.go | 272 |
1 files changed, 271 insertions, 1 deletions
diff --git a/vendor/golang.org/x/net/bpf/instructions.go b/vendor/golang.org/x/net/bpf/instructions.go index 68ae6f549..3b4fd0891 100644 --- a/vendor/golang.org/x/net/bpf/instructions.go +++ b/vendor/golang.org/x/net/bpf/instructions.go @@ -57,6 +57,9 @@ func (ri RawInstruction) Disassemble() Instruction { } return LoadScratch{Dst: reg, N: int(ri.K)} case opAddrModeAbsolute: + if ri.K > extOffset+0xffffffff { + return LoadExtension{Num: Extension(-extOffset + ri.K)} + } return LoadAbsolute{Size: sz, Off: ri.K} case opAddrModeIndirect: return LoadIndirect{Size: sz, Off: ri.K} @@ -104,6 +107,14 @@ func (ri RawInstruction) Disassemble() Instruction { case opJumpAlways: return Jump{Skip: ri.K} case opJumpEqual: + if ri.Jt == 0 { + return JumpIf{ + Cond: JumpNotEqual, + Val: ri.K, + SkipTrue: ri.Jf, + SkipFalse: 0, + } + } return JumpIf{ Cond: JumpEqual, Val: ri.K, @@ -111,6 +122,14 @@ func (ri RawInstruction) Disassemble() Instruction { SkipFalse: ri.Jf, } case opJumpGT: + if ri.Jt == 0 { + return JumpIf{ + Cond: JumpLessOrEqual, + Val: ri.K, + SkipTrue: ri.Jf, + SkipFalse: 0, + } + } return JumpIf{ Cond: JumpGreaterThan, Val: ri.K, @@ -118,6 +137,14 @@ func (ri RawInstruction) Disassemble() Instruction { SkipFalse: ri.Jf, } case opJumpGE: + if ri.Jt == 0 { + return JumpIf{ + Cond: JumpLessThan, + Val: ri.K, + SkipTrue: ri.Jf, + SkipFalse: 0, + } + } return JumpIf{ Cond: JumpGreaterOrEqual, Val: ri.K, @@ -171,6 +198,18 @@ func (a LoadConstant) Assemble() (RawInstruction, error) { return assembleLoad(a.Dst, 4, opAddrModeImmediate, a.Val) } +// String returns the the instruction in assembler notation. +func (a LoadConstant) String() string { + switch a.Dst { + case RegA: + return fmt.Sprintf("ld #%d", a.Val) + case RegX: + return fmt.Sprintf("ldx #%d", a.Val) + default: + return fmt.Sprintf("unknown instruction: %#v", a) + } +} + // LoadScratch loads scratch[N] into register Dst. type LoadScratch struct { Dst Register @@ -185,6 +224,18 @@ func (a LoadScratch) Assemble() (RawInstruction, error) { return assembleLoad(a.Dst, 4, opAddrModeScratch, uint32(a.N)) } +// String returns the the instruction in assembler notation. +func (a LoadScratch) String() string { + switch a.Dst { + case RegA: + return fmt.Sprintf("ld M[%d]", a.N) + case RegX: + return fmt.Sprintf("ldx M[%d]", a.N) + default: + return fmt.Sprintf("unknown instruction: %#v", a) + } +} + // LoadAbsolute loads packet[Off:Off+Size] as an integer value into // register A. type LoadAbsolute struct { @@ -197,6 +248,23 @@ func (a LoadAbsolute) Assemble() (RawInstruction, error) { return assembleLoad(RegA, a.Size, opAddrModeAbsolute, a.Off) } +// String returns the the instruction in assembler notation. +func (a LoadAbsolute) String() string { + switch a.Size { + case 1: // byte + return fmt.Sprintf("ldb [%d]", a.Off) + case 2: // half word + return fmt.Sprintf("ldh [%d]", a.Off) + case 4: // word + if a.Off > extOffset+0xffffffff { + return LoadExtension{Num: Extension(a.Off + 0x1000)}.String() + } + return fmt.Sprintf("ld [%d]", a.Off) + default: + return fmt.Sprintf("unknown instruction: %#v", a) + } +} + // LoadIndirect loads packet[X+Off:X+Off+Size] as an integer value // into register A. type LoadIndirect struct { @@ -209,6 +277,20 @@ func (a LoadIndirect) Assemble() (RawInstruction, error) { return assembleLoad(RegA, a.Size, opAddrModeIndirect, a.Off) } +// String returns the the instruction in assembler notation. +func (a LoadIndirect) String() string { + switch a.Size { + case 1: // byte + return fmt.Sprintf("ldb [x + %d]", a.Off) + case 2: // half word + return fmt.Sprintf("ldh [x + %d]", a.Off) + case 4: // word + return fmt.Sprintf("ld [x + %d]", a.Off) + default: + return fmt.Sprintf("unknown instruction: %#v", a) + } +} + // LoadMemShift multiplies the first 4 bits of the byte at packet[Off] // by 4 and stores the result in register X. // @@ -224,6 +306,11 @@ func (a LoadMemShift) Assemble() (RawInstruction, error) { return assembleLoad(RegX, 1, opAddrModeMemShift, a.Off) } +// String returns the the instruction in assembler notation. +func (a LoadMemShift) String() string { + return fmt.Sprintf("ldx 4*([%d]&0xf)", a.Off) +} + // LoadExtension invokes a linux-specific extension and stores the // result in register A. type LoadExtension struct { @@ -235,7 +322,47 @@ func (a LoadExtension) Assemble() (RawInstruction, error) { if a.Num == ExtLen { return assembleLoad(RegA, 4, opAddrModePacketLen, 0) } - return assembleLoad(RegA, 4, opAddrModeAbsolute, uint32(-0x1000+a.Num)) + return assembleLoad(RegA, 4, opAddrModeAbsolute, uint32(extOffset+a.Num)) +} + +// String returns the the instruction in assembler notation. +func (a LoadExtension) String() string { + switch a.Num { + case ExtLen: + return "ld #len" + case ExtProto: + return "ld #proto" + case ExtType: + return "ld #type" + case ExtPayloadOffset: + return "ld #poff" + case ExtInterfaceIndex: + return "ld #ifidx" + case ExtNetlinkAttr: + return "ld #nla" + case ExtNetlinkAttrNested: + return "ld #nlan" + case ExtMark: + return "ld #mark" + case ExtQueue: + return "ld #queue" + case ExtLinkLayerType: + return "ld #hatype" + case ExtRXHash: + return "ld #rxhash" + case ExtCPUID: + return "ld #cpu" + case ExtVLANTag: + return "ld #vlan_tci" + case ExtVLANTagPresent: + return "ld #vlan_avail" + case ExtVLANProto: + return "ld #vlan_tpid" + case ExtRand: + return "ld #rand" + default: + return fmt.Sprintf("unknown instruction: %#v", a) + } } // StoreScratch stores register Src into scratch[N]. @@ -265,6 +392,18 @@ func (a StoreScratch) Assemble() (RawInstruction, error) { }, nil } +// String returns the the instruction in assembler notation. +func (a StoreScratch) String() string { + switch a.Src { + case RegA: + return fmt.Sprintf("st M[%d]", a.N) + case RegX: + return fmt.Sprintf("stx M[%d]", a.N) + default: + return fmt.Sprintf("unknown instruction: %#v", a) + } +} + // ALUOpConstant executes A = A <Op> Val. type ALUOpConstant struct { Op ALUOp @@ -279,6 +418,34 @@ func (a ALUOpConstant) Assemble() (RawInstruction, error) { }, nil } +// String returns the the instruction in assembler notation. +func (a ALUOpConstant) String() string { + switch a.Op { + case ALUOpAdd: + return fmt.Sprintf("add #%d", a.Val) + case ALUOpSub: + return fmt.Sprintf("sub #%d", a.Val) + case ALUOpMul: + return fmt.Sprintf("mul #%d", a.Val) + case ALUOpDiv: + return fmt.Sprintf("div #%d", a.Val) + case ALUOpMod: + return fmt.Sprintf("mod #%d", a.Val) + case ALUOpAnd: + return fmt.Sprintf("and #%d", a.Val) + case ALUOpOr: + return fmt.Sprintf("or #%d", a.Val) + case ALUOpXor: + return fmt.Sprintf("xor #%d", a.Val) + case ALUOpShiftLeft: + return fmt.Sprintf("lsh #%d", a.Val) + case ALUOpShiftRight: + return fmt.Sprintf("rsh #%d", a.Val) + default: + return fmt.Sprintf("unknown instruction: %#v", a) + } +} + // ALUOpX executes A = A <Op> X type ALUOpX struct { Op ALUOp @@ -291,6 +458,34 @@ func (a ALUOpX) Assemble() (RawInstruction, error) { }, nil } +// String returns the the instruction in assembler notation. +func (a ALUOpX) String() string { + switch a.Op { + case ALUOpAdd: + return "add x" + case ALUOpSub: + return "sub x" + case ALUOpMul: + return "mul x" + case ALUOpDiv: + return "div x" + case ALUOpMod: + return "mod x" + case ALUOpAnd: + return "and x" + case ALUOpOr: + return "or x" + case ALUOpXor: + return "xor x" + case ALUOpShiftLeft: + return "lsh x" + case ALUOpShiftRight: + return "rsh x" + default: + return fmt.Sprintf("unknown instruction: %#v", a) + } +} + // NegateA executes A = -A. type NegateA struct{} @@ -301,6 +496,11 @@ func (a NegateA) Assemble() (RawInstruction, error) { }, nil } +// String returns the the instruction in assembler notation. +func (a NegateA) String() string { + return fmt.Sprintf("neg") +} + // Jump skips the following Skip instructions in the program. type Jump struct { Skip uint32 @@ -314,6 +514,11 @@ func (a Jump) Assemble() (RawInstruction, error) { }, nil } +// String returns the the instruction in assembler notation. +func (a Jump) String() string { + return fmt.Sprintf("ja %d", a.Skip) +} + // JumpIf skips the following Skip instructions in the program if A // <Cond> Val is true. type JumpIf struct { @@ -361,6 +566,51 @@ func (a JumpIf) Assemble() (RawInstruction, error) { }, nil } +// String returns the the instruction in assembler notation. +func (a JumpIf) String() string { + switch a.Cond { + // K == A + case JumpEqual: + return conditionalJump(a, "jeq", "jneq") + // K != A + case JumpNotEqual: + return fmt.Sprintf("jneq #%d,%d", a.Val, a.SkipTrue) + // K > A + case JumpGreaterThan: + return conditionalJump(a, "jgt", "jle") + // K < A + case JumpLessThan: + return fmt.Sprintf("jlt #%d,%d", a.Val, a.SkipTrue) + // K >= A + case JumpGreaterOrEqual: + return conditionalJump(a, "jge", "jlt") + // K <= A + case JumpLessOrEqual: + return fmt.Sprintf("jle #%d,%d", a.Val, a.SkipTrue) + // K & A != 0 + case JumpBitsSet: + if a.SkipFalse > 0 { + return fmt.Sprintf("jset #%d,%d,%d", a.Val, a.SkipTrue, a.SkipFalse) + } + return fmt.Sprintf("jset #%d,%d", a.Val, a.SkipTrue) + // K & A == 0, there is no assembler instruction for JumpBitNotSet, use JumpBitSet and invert skips + case JumpBitsNotSet: + return JumpIf{Cond: JumpBitsSet, SkipTrue: a.SkipFalse, SkipFalse: a.SkipTrue, Val: a.Val}.String() + default: + return fmt.Sprintf("unknown instruction: %#v", a) + } +} + +func conditionalJump(inst JumpIf, positiveJump, negativeJump string) string { + if inst.SkipTrue > 0 { + if inst.SkipFalse > 0 { + return fmt.Sprintf("%s #%d,%d,%d", positiveJump, inst.Val, inst.SkipTrue, inst.SkipFalse) + } + return fmt.Sprintf("%s #%d,%d", positiveJump, inst.Val, inst.SkipTrue) + } + return fmt.Sprintf("%s #%d,%d", negativeJump, inst.Val, inst.SkipFalse) +} + // RetA exits the BPF program, returning the value of register A. type RetA struct{} @@ -371,6 +621,11 @@ func (a RetA) Assemble() (RawInstruction, error) { }, nil } +// String returns the the instruction in assembler notation. +func (a RetA) String() string { + return fmt.Sprintf("ret a") +} + // RetConstant exits the BPF program, returning a constant value. type RetConstant struct { Val uint32 @@ -384,6 +639,11 @@ func (a RetConstant) Assemble() (RawInstruction, error) { }, nil } +// String returns the the instruction in assembler notation. +func (a RetConstant) String() string { + return fmt.Sprintf("ret #%d", a.Val) +} + // TXA copies the value of register X to register A. type TXA struct{} @@ -394,6 +654,11 @@ func (a TXA) Assemble() (RawInstruction, error) { }, nil } +// String returns the the instruction in assembler notation. +func (a TXA) String() string { + return fmt.Sprintf("txa") +} + // TAX copies the value of register A to register X. type TAX struct{} @@ -404,6 +669,11 @@ func (a TAX) Assemble() (RawInstruction, error) { }, nil } +// String returns the the instruction in assembler notation. +func (a TAX) String() string { + return fmt.Sprintf("tax") +} + func assembleLoad(dst Register, loadSize int, mode uint16, k uint32) (RawInstruction, error) { var ( cls uint16 |