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// Copyright 2021 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.
//go:build linux
// +build linux
package unix
import (
"bytes"
"net"
"testing"
"unsafe"
)
// An ifreqUnion is shorthand for a byte array matching the
// architecture-dependent size of an ifreq's union field.
type ifreqUnion = [len(ifreq{}.Ifru)]byte
func TestNewIfreq(t *testing.T) {
// Interface name too long.
if _, err := NewIfreq("abcdefghijklmnop"); err != EINVAL {
t.Fatalf("expected error EINVAL, but got: %v", err)
}
}
func TestIfreqSize(t *testing.T) {
// Ensure ifreq (generated) and Ifreq/ifreqData (hand-written to create a
// safe wrapper and store a pointer field) are identical in size.
want := unsafe.Sizeof(ifreq{})
if got := unsafe.Sizeof(Ifreq{}); want != got {
t.Fatalf("unexpected Ifreq size: got: %d, want: %d", got, want)
}
if got := unsafe.Sizeof(ifreqData{}); want != got {
t.Fatalf("unexpected IfreqData size: got: %d, want: %d", got, want)
}
}
func TestIfreqName(t *testing.T) {
// Valid ifreq, expect the hard-coded testIfreq name.
ifr := testIfreq(t)
if want, got := ifreqName, ifr.Name(); want != got {
t.Fatalf("unexpected ifreq name: got: %q, want: %q", got, want)
}
}
func TestIfreqWithData(t *testing.T) {
ifr := testIfreq(t)
// Store pointer data in the ifreq so we can retrieve it and cast back later
// for comparison.
want := [5]byte{'h', 'e', 'l', 'l', 'o'}
ifrd := ifr.withData(unsafe.Pointer(&want[0]))
// Ensure the memory of the original Ifreq was not modified by SetData.
if ifr.raw.Ifru != (ifreqUnion{}) {
t.Fatalf("ifreq was unexpectedly modified: % #x", ifr.raw.Ifru)
}
got := *(*[5]byte)(ifrd.data)
if want != got {
t.Fatalf("unexpected ifreq data bytes:\n got: % #x\nwant: % #x", got, want)
}
}
func TestIfreqInet4Addr(t *testing.T) {
ifr := testIfreq(t)
in := net.IPv4(192, 0, 2, 1).To4()
if err := ifr.SetInet4Addr(in); err != nil {
t.Fatalf("failed to set ifreq IPv4 address: %v", err)
}
// Store fixed offset data (AF_INET, IPv4 address) within underlying
// sockaddr bytes. Everything else should be zeroed.
want := ifreqUnion{4: 192, 5: 0, 6: 2, 7: 1}
if isBigEndian {
want[0] = 0x00
want[1] = 0x02
} else {
want[0] = 0x02
want[1] = 0x00
}
if got := ifr.raw.Ifru; want != got {
t.Fatalf("unexpected ifreq sockaddr bytes:\n got: % #x\nwant: % #x", got, want)
}
got, err := ifr.Inet4Addr()
if err != nil {
t.Fatalf("failed to get ifreq IPv4 address: %v", err)
}
if !bytes.Equal(in, got) {
t.Fatalf("unexpected ifreq IPv4 address:\n got: % #x\nwant: % #x", got, in)
}
// Invalid input, wrong length.
if err := ifr.SetInet4Addr([]byte{0xff}); err == nil {
t.Fatal("expected an error setting invalid IPv4 address, but none occurred")
}
// Invalid output, AF_INET is only set by SetInet4Addr input.
ifr.SetUint32(0xffffffff)
if _, err := ifr.Inet4Addr(); err == nil {
t.Fatal("expected an error getting invalid IPv4 address, but none occurred")
}
}
func TestIfreqUint16(t *testing.T) {
ifr := testIfreq(t)
const in = 0x0102
ifr.SetUint16(in)
// The layout of the bytes depends on the machine's endianness.
var want ifreqUnion
if isBigEndian {
want[0] = 0x01
want[1] = 0x02
} else {
want[0] = 0x02
want[1] = 0x01
}
if got := ifr.raw.Ifru; want != got {
t.Fatalf("unexpected ifreq uint16 bytes:\n got: % #x\nwant: % #x", got, want)
}
if got := ifr.Uint16(); in != got {
t.Fatalf("unexpected ifreq uint16: got: %d, want: %d", got, in)
}
}
func TestIfreqUint32(t *testing.T) {
ifr := testIfreq(t)
const in = 0x01020304
ifr.SetUint32(in)
// The layout of the bytes depends on the machine's endianness.
var want ifreqUnion
if isBigEndian {
want[0] = 0x01
want[1] = 0x02
want[2] = 0x03
want[3] = 0x04
} else {
want[0] = 0x04
want[1] = 0x03
want[2] = 0x02
want[3] = 0x01
}
if got := ifr.raw.Ifru; want != got {
t.Fatalf("unexpected ifreq uint32 bytes:\n got: % #x\nwant: % #x", got, want)
}
if got := ifr.Uint32(); in != got {
t.Fatalf("unexpected ifreq uint32: got: %d, want: %d", got, in)
}
}
// ifreqName is a hard-coded name for testIfreq.
const ifreqName = "eth0"
// testIfreq returns an Ifreq with a populated interface name.
func testIfreq(t *testing.T) *Ifreq {
t.Helper()
ifr, err := NewIfreq(ifreqName)
if err != nil {
t.Fatalf("failed to create ifreq: %v", err)
}
return ifr
}