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Commit 49bb7cea authored by Arthur Fabre's avatar Arthur Fabre Committed by Brad Fitzpatrick
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bpf: support JumpIf on RegX instead of K 

Add a JumpIfX instruction which implements conditional jumps using
RegA and RegX. This is in addition to the pre-existing JumpIf
instruction which uses RegA and K.

This instruction / addressing mode is not mentionned in the original BPF
paper, but is supported by tools like bpf_asm, and has recently been
added to the kernel's filter.txt.

Simplify some of the parsing logic, and add a separate helper for
checking for "fake" JumpIfs.

Add JumpIfX support to the BPF vm.

Update testdata with JumpIfX instructions, and add tests
for both the assembler/disassembler and vm.

Fixes golang/go#27814

Change-Id: I0c3f6ac7eb5b4cd4d9c5af8784ee2e8d25195a0a
GitHub-Last-Rev: 39a88165b2d3253c37db4b0e303d862b60dc37c9
GitHub-Pull-Request: golang/net#20
Reviewed-on: https://go-review.googlesource.com/c/136895Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
parent 146acd28
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Showing with 587 additions and 121 deletions
bpf/constants.go
View file @ 49bb7cea
......@@ -38,6 +38,7 @@ const (
type JumpTest uint16
// Supported operators for conditional jumps.
// K can be RegX for JumpIfX
const (
// K == A
JumpEqual JumpTest = iota
......@@ -134,12 +135,9 @@ const (
opMaskLoadDest = 0x01
opMaskLoadWidth = 0x18
opMaskLoadMode = 0xe0
// opClsALU
opMaskOperandSrc = 0x08
opMaskOperator = 0xf0
// opClsJump
opMaskJumpConst = 0x0f
opMaskJumpCond = 0xf0
// opClsALU & opClsJump
opMaskOperand = 0x08
opMaskOperator = 0xf0
)
const (
......@@ -192,15 +190,21 @@ const (
opLoadWidth1
)
// Operator defined by ALUOp*
// Operand for ALU and Jump instructions
type opOperand uint16
// Supported operand sources.
const (
opALUSrcConstant uint16 = iota << 3
opALUSrcX
opOperandConstant opOperand = iota << 3
opOperandX
)
// An jumpOp is a conditional jump condition.
type jumpOp uint16
// Supported jump conditions.
const (
opJumpAlways = iota << 4
opJumpAlways jumpOp = iota << 4
opJumpEqual
opJumpGT
opJumpGE
......
bpf/instructions.go
View file @ 49bb7cea
......@@ -89,10 +89,14 @@ func (ri RawInstruction) Disassemble() Instruction {
case opClsALU:
switch op := ALUOp(ri.Op & opMaskOperator); op {
case ALUOpAdd, ALUOpSub, ALUOpMul, ALUOpDiv, ALUOpOr, ALUOpAnd, ALUOpShiftLeft, ALUOpShiftRight, ALUOpMod, ALUOpXor:
if ri.Op&opMaskOperandSrc != 0 {
switch operand := opOperand(ri.Op & opMaskOperand); operand {
case opOperandX:
return ALUOpX{Op: op}
case opOperandConstant:
return ALUOpConstant{Op: op, Val: ri.K}
default:
return ri
}
return ALUOpConstant{Op: op, Val: ri.K}
case aluOpNeg:
return NegateA{}
default:
......@@ -100,63 +104,18 @@ func (ri RawInstruction) Disassemble() Instruction {
}
case opClsJump:
if ri.Op&opMaskJumpConst != opClsJump {
return ri
}
switch ri.Op & opMaskJumpCond {
switch op := jumpOp(ri.Op & opMaskOperator); op {
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,
SkipTrue: ri.Jt,
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,
SkipTrue: ri.Jt,
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,
SkipTrue: ri.Jt,
SkipFalse: ri.Jf,
}
case opJumpSet:
return JumpIf{
Cond: JumpBitsSet,
Val: ri.K,
SkipTrue: ri.Jt,
SkipFalse: ri.Jf,
case opJumpEqual, opJumpGT, opJumpGE, opJumpSet:
cond, skipTrue, skipFalse := jumpOpToTest(op, ri.Jt, ri.Jf)
switch operand := opOperand(ri.Op & opMaskOperand); operand {
case opOperandX:
return JumpIfX{Cond: cond, SkipTrue: skipTrue, SkipFalse: skipFalse}
case opOperandConstant:
return JumpIf{Cond: cond, Val: ri.K, SkipTrue: skipTrue, SkipFalse: skipFalse}
default:
return ri
}
default:
return ri
......@@ -187,6 +146,41 @@ func (ri RawInstruction) Disassemble() Instruction {
}
}
func jumpOpToTest(op jumpOp, skipTrue uint8, skipFalse uint8) (JumpTest, uint8, uint8) {
var test JumpTest
// Decode "fake" jump conditions that don't appear in machine code
// Ensures the Assemble -> Disassemble stage recreates the same instructions
// See https://github.com/golang/go/issues/18470
if skipTrue == 0 {
switch op {
case opJumpEqual:
test = JumpNotEqual
case opJumpGT:
test = JumpLessOrEqual
case opJumpGE:
test = JumpLessThan
case opJumpSet:
test = JumpBitsNotSet
}
return test, skipFalse, 0
}
switch op {
case opJumpEqual:
test = JumpEqual
case opJumpGT:
test = JumpGreaterThan
case opJumpGE:
test = JumpGreaterOrEqual
case opJumpSet:
test = JumpBitsSet
}
return test, skipTrue, skipFalse
}
// LoadConstant loads Val into register Dst.
type LoadConstant struct {
Dst Register
......@@ -413,7 +407,7 @@ type ALUOpConstant struct {
// Assemble implements the Instruction Assemble method.
func (a ALUOpConstant) Assemble() (RawInstruction, error) {
return RawInstruction{
Op: opClsALU | opALUSrcConstant | uint16(a.Op),
Op: opClsALU | uint16(opOperandConstant) | uint16(a.Op),
K: a.Val,
}, nil
}
......@@ -454,7 +448,7 @@ type ALUOpX struct {
// Assemble implements the Instruction Assemble method.
func (a ALUOpX) Assemble() (RawInstruction, error) {
return RawInstruction{
Op: opClsALU | opALUSrcX | uint16(a.Op),
Op: opClsALU | uint16(opOperandX) | uint16(a.Op),
}, nil
}
......@@ -509,7 +503,7 @@ type Jump struct {
// Assemble implements the Instruction Assemble method.
func (a Jump) Assemble() (RawInstruction, error) {
return RawInstruction{
Op: opClsJump | opJumpAlways,
Op: opClsJump | uint16(opJumpAlways),
K: a.Skip,
}, nil
}
......@@ -530,11 +524,39 @@ type JumpIf struct {
// Assemble implements the Instruction Assemble method.
func (a JumpIf) Assemble() (RawInstruction, error) {
return jumpToRaw(a.Cond, opOperandConstant, a.Val, a.SkipTrue, a.SkipFalse)
}
// String returns the instruction in assembler notation.
func (a JumpIf) String() string {
return jumpToString(a.Cond, fmt.Sprintf("#%d", a.Val), a.SkipTrue, a.SkipFalse)
}
// JumpIfX skips the following Skip instructions in the program if A
// <Cond> X is true.
type JumpIfX struct {
Cond JumpTest
SkipTrue uint8
SkipFalse uint8
}
// Assemble implements the Instruction Assemble method.
func (a JumpIfX) Assemble() (RawInstruction, error) {
return jumpToRaw(a.Cond, opOperandX, 0, a.SkipTrue, a.SkipFalse)
}
// String returns the instruction in assembler notation.
func (a JumpIfX) String() string {
return jumpToString(a.Cond, "x", a.SkipTrue, a.SkipFalse)
}
// jumpToRaw assembles a jump instruction into a RawInstruction
func jumpToRaw(test JumpTest, operand opOperand, k uint32, skipTrue, skipFalse uint8) (RawInstruction, error) {
var (
cond uint16
cond jumpOp
flip bool
)
switch a.Cond {
switch test {
case JumpEqual:
cond = opJumpEqual
case JumpNotEqual:
......@@ -552,63 +574,63 @@ func (a JumpIf) Assemble() (RawInstruction, error) {
case JumpBitsNotSet:
cond, flip = opJumpSet, true
default:
return RawInstruction{}, fmt.Errorf("unknown JumpTest %v", a.Cond)
return RawInstruction{}, fmt.Errorf("unknown JumpTest %v", test)
}
jt, jf := a.SkipTrue, a.SkipFalse
jt, jf := skipTrue, skipFalse
if flip {
jt, jf = jf, jt
}
return RawInstruction{
Op: opClsJump | cond,
Op: opClsJump | uint16(cond) | uint16(operand),
Jt: jt,
Jf: jf,
K: a.Val,
K: k,
}, nil
}
// String returns the instruction in assembler notation.
func (a JumpIf) String() string {
switch a.Cond {
// jumpToString converts a jump instruction to assembler notation
func jumpToString(cond JumpTest, operand string, skipTrue, skipFalse uint8) string {
switch cond {
// K == A
case JumpEqual:
return conditionalJump(a, "jeq", "jneq")
return conditionalJump(operand, skipTrue, skipFalse, "jeq", "jneq")
// K != A
case JumpNotEqual:
return fmt.Sprintf("jneq #%d,%d", a.Val, a.SkipTrue)
return fmt.Sprintf("jneq %s,%d", operand, skipTrue)
// K > A
case JumpGreaterThan:
return conditionalJump(a, "jgt", "jle")
return conditionalJump(operand, skipTrue, skipFalse, "jgt", "jle")
// K < A
case JumpLessThan:
return fmt.Sprintf("jlt #%d,%d", a.Val, a.SkipTrue)
return fmt.Sprintf("jlt %s,%d", operand, skipTrue)
// K >= A
case JumpGreaterOrEqual:
return conditionalJump(a, "jge", "jlt")
return conditionalJump(operand, skipTrue, skipFalse, "jge", "jlt")
// K <= A
case JumpLessOrEqual:
return fmt.Sprintf("jle #%d,%d", a.Val, a.SkipTrue)
return fmt.Sprintf("jle %s,%d", operand, skipTrue)
// K & A != 0
case JumpBitsSet:
if a.SkipFalse > 0 {
return fmt.Sprintf("jset #%d,%d,%d", a.Val, a.SkipTrue, a.SkipFalse)
if skipFalse > 0 {
return fmt.Sprintf("jset %s,%d,%d", operand, skipTrue, skipFalse)
}
return fmt.Sprintf("jset #%d,%d", a.Val, a.SkipTrue)
return fmt.Sprintf("jset %s,%d", operand, 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()
return jumpToString(JumpBitsSet, operand, skipFalse, skipTrue)
default:
return fmt.Sprintf("unknown instruction: %#v", a)
return fmt.Sprintf("unknown JumpTest %#v", cond)
}
}
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)
func conditionalJump(operand string, skipTrue, skipFalse uint8, positiveJump, negativeJump string) string {
if skipTrue > 0 {
if skipFalse > 0 {
return fmt.Sprintf("%s %s,%d,%d", positiveJump, operand, skipTrue, skipFalse)
}
return fmt.Sprintf("%s #%d,%d", positiveJump, inst.Val, inst.SkipTrue)
return fmt.Sprintf("%s %s,%d", positiveJump, operand, skipTrue)
}
return fmt.Sprintf("%s #%d,%d", negativeJump, inst.Val, inst.SkipFalse)
return fmt.Sprintf("%s %s,%d", negativeJump, operand, skipFalse)
}
// RetA exits the BPF program, returning the value of register A.
......
bpf/instructions_test.go
View file @ 49bb7cea
......@@ -64,14 +64,22 @@ var allInstructions = []Instruction{
NegateA{},
Jump{Skip: 10},
JumpIf{Cond: JumpEqual, Val: 42, SkipTrue: 8, SkipFalse: 9},
JumpIf{Cond: JumpNotEqual, Val: 42, SkipTrue: 8},
JumpIf{Cond: JumpLessThan, Val: 42, SkipTrue: 7},
JumpIf{Cond: JumpLessOrEqual, Val: 42, SkipTrue: 6},
JumpIf{Cond: JumpGreaterThan, Val: 42, SkipTrue: 4, SkipFalse: 5},
JumpIf{Cond: JumpGreaterOrEqual, Val: 42, SkipTrue: 3, SkipFalse: 4},
JumpIf{Cond: JumpBitsSet, Val: 42, SkipTrue: 2, SkipFalse: 3},
Jump{Skip: 17},
JumpIf{Cond: JumpEqual, Val: 42, SkipTrue: 15, SkipFalse: 16},
JumpIf{Cond: JumpNotEqual, Val: 42, SkipTrue: 15},
JumpIf{Cond: JumpLessThan, Val: 42, SkipTrue: 14},
JumpIf{Cond: JumpLessOrEqual, Val: 42, SkipTrue: 13},
JumpIf{Cond: JumpGreaterThan, Val: 42, SkipTrue: 11, SkipFalse: 12},
JumpIf{Cond: JumpGreaterOrEqual, Val: 42, SkipTrue: 10, SkipFalse: 11},
JumpIf{Cond: JumpBitsSet, Val: 42, SkipTrue: 9, SkipFalse: 10},
JumpIfX{Cond: JumpEqual, SkipTrue: 8, SkipFalse: 9},
JumpIfX{Cond: JumpNotEqual, SkipTrue: 8},
JumpIfX{Cond: JumpLessThan, SkipTrue: 7},
JumpIfX{Cond: JumpLessOrEqual, SkipTrue: 6},
JumpIfX{Cond: JumpGreaterThan, SkipTrue: 4, SkipFalse: 5},
JumpIfX{Cond: JumpGreaterOrEqual, SkipTrue: 3, SkipFalse: 4},
JumpIfX{Cond: JumpBitsSet, SkipTrue: 2, SkipFalse: 3},
TAX{},
TXA{},
......@@ -487,7 +495,67 @@ func TestString(t *testing.T) {
},
{
instruction: JumpIf{Cond: 0xffff, Val: 42, SkipTrue: 1, SkipFalse: 2},
assembler: "unknown instruction: bpf.JumpIf{Cond:0xffff, Val:0x2a, SkipTrue:0x1, SkipFalse:0x2}",
assembler: "unknown JumpTest 0xffff",
},
{
instruction: JumpIfX{Cond: JumpEqual, SkipTrue: 8, SkipFalse: 9},
assembler: "jeq x,8,9",
},
{
instruction: JumpIfX{Cond: JumpEqual, SkipTrue: 8},
assembler: "jeq x,8",
},
{
instruction: JumpIfX{Cond: JumpEqual, SkipFalse: 8},
assembler: "jneq x,8",
},
{
instruction: JumpIfX{Cond: JumpNotEqual, SkipTrue: 8},
assembler: "jneq x,8",
},
{
instruction: JumpIfX{Cond: JumpLessThan, SkipTrue: 7},
assembler: "jlt x,7",
},
{
instruction: JumpIfX{Cond: JumpLessOrEqual, SkipTrue: 6},
assembler: "jle x,6",
},
{
instruction: JumpIfX{Cond: JumpGreaterThan, SkipTrue: 4, SkipFalse: 5},
assembler: "jgt x,4,5",
},
{
instruction: JumpIfX{Cond: JumpGreaterThan, SkipTrue: 4},
assembler: "jgt x,4",
},
{
instruction: JumpIfX{Cond: JumpGreaterOrEqual, SkipTrue: 3, SkipFalse: 4},
assembler: "jge x,3,4",
},
{
instruction: JumpIfX{Cond: JumpGreaterOrEqual, SkipTrue: 3},
assembler: "jge x,3",
},
{
instruction: JumpIfX{Cond: JumpBitsSet, SkipTrue: 2, SkipFalse: 3},
assembler: "jset x,2,3",
},
{
instruction: JumpIfX{Cond: JumpBitsSet, SkipTrue: 2},
assembler: "jset x,2",
},
{
instruction: JumpIfX{Cond: JumpBitsNotSet, SkipTrue: 2, SkipFalse: 3},
assembler: "jset x,3,2",
},
{
instruction: JumpIfX{Cond: JumpBitsNotSet, SkipTrue: 2},
assembler: "jset x,0,2",
},
{
instruction: JumpIfX{Cond: 0xffff, SkipTrue: 1, SkipFalse: 2},
assembler: "unknown JumpTest 0xffff",
},
{
instruction: TAX{},
......
bpf/testdata/all_instructions.bpf
View file @ 49bb7cea
50,0 0 0 42,1 0 0 42,96 0 0 3,97 0 0 3,48 0 0 42,40 0 0 42,32 0 0 42,80 0 0 42,72 0 0 42,64 0 0 42,177 0 0 42,128 0 0 0,32 0 0 4294963200,32 0 0 4294963204,32 0 0 4294963256,2 0 0 3,3 0 0 3,4 0 0 42,20 0 0 42,36 0 0 42,52 0 0 42,68 0 0 42,84 0 0 42,100 0 0 42,116 0 0 42,148 0 0 42,164 0 0 42,12 0 0 0,28 0 0 0,44 0 0 0,60 0 0 0,76 0 0 0,92 0 0 0,108 0 0 0,124 0 0 0,156 0 0 0,172 0 0 0,132 0 0 0,5 0 0 10,21 8 9 42,21 0 8 42,53 0 7 42,37 0 6 42,37 4 5 42,53 3 4 42,69 2 3 42,7 0 0 0,135 0 0 0,22 0 0 0,6 0 0 0,
57,0 0 0 42,1 0 0 42,96 0 0 3,97 0 0 3,48 0 0 42,40 0 0 42,32 0 0 42,80 0 0 42,72 0 0 42,64 0 0 42,177 0 0 42,128 0 0 0,32 0 0 4294963200,32 0 0 4294963204,32 0 0 4294963256,2 0 0 3,3 0 0 3,4 0 0 42,20 0 0 42,36 0 0 42,52 0 0 42,68 0 0 42,84 0 0 42,100 0 0 42,116 0 0 42,148 0 0 42,164 0 0 42,12 0 0 0,28 0 0 0,44 0 0 0,60 0 0 0,76 0 0 0,92 0 0 0,108 0 0 0,124 0 0 0,156 0 0 0,172 0 0 0,132 0 0 0,5 0 0 17,21 15 16 42,21 0 15 42,53 0 14 42,37 0 13 42,37 11 12 42,53 10 11 42,69 9 10 42,29 8 9 0,29 0 8 0,61 0 7 0,45 0 6 0,45 4 5 0,61 3 4 0,77 2 3 0,7 0 0 0,135 0 0 0,22 0 0 0,6 0 0 42,
bpf/testdata/all_instructions.txt
View file @ 49bb7cea
# This filter is compiled to all_instructions.bpf by the `bpf_asm`
# tool, which can be found in the linux kernel source tree under
# tools/net.
# tools/bpf.
# Load immediate
ld #42
......@@ -60,7 +60,7 @@ xor x
# !A
neg
# Jumps
# Jump A <op> constant
ja end
jeq #42,prev,end
jne #42,end
......@@ -70,6 +70,15 @@ jgt #42,prev,end
jge #42,prev,end
jset #42,prev,end
# Jump A <op> X
jeq x,prev,end
jne x,end
jlt x,end
jle x,end
jgt x,prev,end
jge x,prev,end
jset x,prev,end
# Register transfers
tax
txa
......
bpf/vm.go
View file @ 49bb7cea
......@@ -35,6 +35,13 @@ func NewVM(filter []Instruction) (*VM, error) {
if check <= int(ins.SkipFalse) {
return nil, fmt.Errorf("cannot jump %d instructions in false case; jumping past program bounds", ins.SkipFalse)
}
case JumpIfX:
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 {
......@@ -109,6 +116,9 @@ func (v *VM) Run(in []byte) (int, error) {
case JumpIf:
jump := jumpIf(ins, regA)
i += jump
case JumpIfX:
jump := jumpIfX(ins, regA, regX)
i += jump
case LoadAbsolute:
regA, ok = loadAbsolute(ins, in)
case LoadConstant:
......
bpf/vm_instructions.go
View file @ 49bb7cea
......@@ -55,34 +55,41 @@ func aluOpCommon(op ALUOp, regA uint32, value uint32) uint32 {
}
}
func jumpIf(ins JumpIf, value uint32) int {
func jumpIf(ins JumpIf, regA uint32) int {
return jumpIfCommon(ins.Cond, ins.SkipTrue, ins.SkipFalse, regA, ins.Val)
}
func jumpIfX(ins JumpIfX, regA uint32, regX uint32) int {
return jumpIfCommon(ins.Cond, ins.SkipTrue, ins.SkipFalse, regA, regX)
}
func jumpIfCommon(cond JumpTest, skipTrue, skipFalse uint8, regA uint32, value uint32) int {
var ok bool
inV := uint32(ins.Val)
switch ins.Cond {
switch cond {
case JumpEqual:
ok = value == inV
ok = regA == value
case JumpNotEqual:
ok = value != inV
ok = regA != value
case JumpGreaterThan:
ok = value > inV
ok = regA > value
case JumpLessThan:
ok = value < inV
ok = regA < value
case JumpGreaterOrEqual:
ok = value >= inV
ok = regA >= value
case JumpLessOrEqual:
ok = value <= inV
ok = regA <= value
case JumpBitsSet:
ok = (value & inV) != 0
ok = (regA & value) != 0
case JumpBitsNotSet:
ok = (value & inV) == 0
ok = (regA & value) == 0
}
if ok {
return int(ins.SkipTrue)
return int(skipTrue)
}
return int(ins.SkipFalse)
return int(skipFalse)
}
func loadAbsolute(ins LoadAbsolute, in []byte) (uint32, bool) {
......
bpf/vm_jump_test.go
View file @ 49bb7cea
......@@ -83,6 +83,32 @@ func TestVMJumpIfFalseOutOfProgram(t *testing.T) {
}
}
func TestVMJumpIfXTrueOutOfProgram(t *testing.T) {
_, _, err := testVM(t, []bpf.Instruction{
bpf.JumpIfX{
Cond: bpf.JumpEqual,
SkipTrue: 2,
},
bpf.RetA{},
})
if errStr(err) != "cannot jump 2 instructions in true case; jumping past program bounds" {
t.Fatalf("unexpected error: %v", err)
}
}
func TestVMJumpIfXFalseOutOfProgram(t *testing.T) {
_, _, err := testVM(t, []bpf.Instruction{
bpf.JumpIfX{
Cond: bpf.JumpEqual,
SkipFalse: 3,
},
bpf.RetA{},
})
if errStr(err) != "cannot jump 3 instructions in false case; jumping past program bounds" {
t.Fatalf("unexpected error: %v", err)
}
}
func TestVMJumpIfEqual(t *testing.T) {
vm, done, err := testVM(t, []bpf.Instruction{
bpf.LoadAbsolute{
......@@ -378,3 +404,323 @@ func TestVMJumpIfBitsNotSet(t *testing.T) {
want, got)
}
}
func TestVMJumpIfXEqual(t *testing.T) {
vm, done, err := testVM(t, []bpf.Instruction{
bpf.LoadAbsolute{
Off: 8,
Size: 1,
},
bpf.LoadConstant{
Dst: bpf.RegX,
Val: 1,
},
bpf.JumpIfX{
Cond: bpf.JumpEqual,
SkipTrue: 1,
},
bpf.RetConstant{
Val: 0,
},
bpf.RetConstant{
Val: 9,
},
})
if err != nil {
t.Fatalf("failed to load BPF program: %v", err)
}
defer done()
out, err := vm.Run([]byte{
0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff,
1,
})
if err != nil {
t.Fatalf("unexpected error while running program: %v", err)
}
if want, got := 1, out; want != got {
t.Fatalf("unexpected number of output bytes:\n- want: %d\n- got: %d",
want, got)
}
}
func TestVMJumpIfXNotEqual(t *testing.T) {
vm, done, err := testVM(t, []bpf.Instruction{
bpf.LoadAbsolute{
Off: 8,
Size: 1,
},
bpf.LoadConstant{
Dst: bpf.RegX,
Val: 1,
},
bpf.JumpIfX{
Cond: bpf.JumpNotEqual,
SkipFalse: 1,
},
bpf.RetConstant{
Val: 0,
},
bpf.RetConstant{
Val: 9,
},
})
if err != nil {
t.Fatalf("failed to load BPF program: %v", err)
}
defer done()
out, err := vm.Run([]byte{
0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff,
1,
})
if err != nil {
t.Fatalf("unexpected error while running program: %v", err)
}
if want, got := 1, out; want != got {
t.Fatalf("unexpected number of output bytes:\n- want: %d\n- got: %d",
want, got)
}
}
func TestVMJumpIfXGreaterThan(t *testing.T) {
vm, done, err := testVM(t, []bpf.Instruction{
bpf.LoadAbsolute{
Off: 8,
Size: 4,
},
bpf.LoadConstant{
Dst: bpf.RegX,
Val: 0x00010202,
},
bpf.JumpIfX{
Cond: bpf.JumpGreaterThan,
SkipTrue: 1,
},
bpf.RetConstant{
Val: 0,
},
bpf.RetConstant{
Val: 12,
},
})
if err != nil {
t.Fatalf("failed to load BPF program: %v", err)
}
defer done()
out, err := vm.Run([]byte{
0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff,
0, 1, 2, 3,
})
if err != nil {
t.Fatalf("unexpected error while running program: %v", err)
}
if want, got := 4, out; want != got {
t.Fatalf("unexpected number of output bytes:\n- want: %d\n- got: %d",
want, got)
}
}
func TestVMJumpIfXLessThan(t *testing.T) {
vm, done, err := testVM(t, []bpf.Instruction{
bpf.LoadAbsolute{
Off: 8,
Size: 4,
},
bpf.LoadConstant{
Dst: bpf.RegX,
Val: 0xff010203,
},
bpf.JumpIfX{
Cond: bpf.JumpLessThan,
SkipTrue: 1,
},
bpf.RetConstant{
Val: 0,
},
bpf.RetConstant{
Val: 12,
},
})
if err != nil {
t.Fatalf("failed to load BPF program: %v", err)
}
defer done()
out, err := vm.Run([]byte{
0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff,
0, 1, 2, 3,
})
if err != nil {
t.Fatalf("unexpected error while running program: %v", err)
}
if want, got := 4, out; want != got {
t.Fatalf("unexpected number of output bytes:\n- want: %d\n- got: %d",
want, got)
}
}
func TestVMJumpIfXGreaterOrEqual(t *testing.T) {
vm, done, err := testVM(t, []bpf.Instruction{
bpf.LoadAbsolute{
Off: 8,
Size: 4,
},
bpf.LoadConstant{
Dst: bpf.RegX,
Val: 0x00010203,
},
bpf.JumpIfX{
Cond: bpf.JumpGreaterOrEqual,
SkipTrue: 1,
},
bpf.RetConstant{
Val: 0,
},
bpf.RetConstant{
Val: 12,
},
})
if err != nil {
t.Fatalf("failed to load BPF program: %v", err)
}
defer done()
out, err := vm.Run([]byte{
0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff,
0, 1, 2, 3,
})
if err != nil {
t.Fatalf("unexpected error while running program: %v", err)
}
if want, got := 4, out; want != got {
t.Fatalf("unexpected number of output bytes:\n- want: %d\n- got: %d",
want, got)
}
}
func TestVMJumpIfXLessOrEqual(t *testing.T) {
vm, done, err := testVM(t, []bpf.Instruction{
bpf.LoadAbsolute{
Off: 8,
Size: 4,
},
bpf.LoadConstant{
Dst: bpf.RegX,
Val: 0xff010203,
},
bpf.JumpIfX{
Cond: bpf.JumpLessOrEqual,
SkipTrue: 1,
},
bpf.RetConstant{
Val: 0,
},
bpf.RetConstant{
Val: 12,
},
})
if err != nil {
t.Fatalf("failed to load BPF program: %v", err)
}
defer done()
out, err := vm.Run([]byte{
0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff,
0, 1, 2, 3,
})
if err != nil {
t.Fatalf("unexpected error while running program: %v", err)
}
if want, got := 4, out; want != got {
t.Fatalf("unexpected number of output bytes:\n- want: %d\n- got: %d",
want, got)
}
}
func TestVMJumpIfXBitsSet(t *testing.T) {
vm, done, err := testVM(t, []bpf.Instruction{
bpf.LoadAbsolute{
Off: 8,
Size: 2,
},
bpf.LoadConstant{
Dst: bpf.RegX,
Val: 0x1122,
},
bpf.JumpIfX{
Cond: bpf.JumpBitsSet,
SkipTrue: 1,
},
bpf.RetConstant{
Val: 0,
},
bpf.RetConstant{
Val: 10,
},
})
if err != nil {
t.Fatalf("failed to load BPF program: %v", err)
}
defer done()
out, err := vm.Run([]byte{
0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff,
0x01, 0x02,
})
if err != nil {
t.Fatalf("unexpected error while running program: %v", err)
}
if want, got := 2, out; want != got {
t.Fatalf("unexpected number of output bytes:\n- want: %d\n- got: %d",
want, got)
}
}
func TestVMJumpIfXBitsNotSet(t *testing.T) {
vm, done, err := testVM(t, []bpf.Instruction{
bpf.LoadAbsolute{
Off: 8,
Size: 2,
},
bpf.LoadConstant{
Dst: bpf.RegX,
Val: 0x1221,
},
bpf.JumpIfX{
Cond: bpf.JumpBitsNotSet,
SkipTrue: 1,
},
bpf.RetConstant{
Val: 0,
},
bpf.RetConstant{
Val: 10,
},
})
if err != nil {
t.Fatalf("failed to load BPF program: %v", err)
}
defer done()
out, err := vm.Run([]byte{
0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff,
0x01, 0x02,
})
if err != nil {
t.Fatalf("unexpected error while running program: %v", err)
}
if want, got := 2, out; want != got {
t.Fatalf("unexpected number of output bytes:\n- want: %d\n- got: %d",
want, got)
}
}
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