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// Copyright 2012 Google, Inc. All rights reserved.
// Copyright 2009-2011 Andreas Krennmair. All rights reserved.
//
// Use of this source code is governed by a BSD-style license
// that can be found in the LICENSE file in the root of the source
// tree.
package pcap
import (
"errors"
"fmt"
"os"
"runtime"
"sync"
"syscall"
"time"
"unsafe"
"github.com/gopacket/gopacket"
"github.com/gopacket/gopacket/layers"
"golang.org/x/sys/windows"
)
var pcapLoaded = false
const npcapPath = "\\Npcap"
func initDllPath(kernel32 syscall.Handle) {
setDllDirectory, err := syscall.GetProcAddress(kernel32, "SetDllDirectoryA")
if err != nil {
// we can't do anything since SetDllDirectoryA is missing - fall back to use first wpcap.dll we encounter
return
}
getSystemDirectory, err := syscall.GetProcAddress(kernel32, "GetSystemDirectoryA")
if err != nil {
// we can't do anything since SetDllDirectoryA is missing - fall back to use first wpcap.dll we encounter
return
}
buf := make([]byte, 4096)
r, _, _ := syscall.Syscall(getSystemDirectory, 2, uintptr(unsafe.Pointer(&buf[0])), uintptr(len(buf)), 0)
if r == 0 || r > 4096-uintptr(len(npcapPath))-1 {
// we can't do anything since SetDllDirectoryA is missing - fall back to use first wpcap.dll we encounter
return
}
copy(buf[r:], npcapPath)
_, _, _ = syscall.Syscall(setDllDirectory, 1, uintptr(unsafe.Pointer(&buf[0])), 0, 0)
// ignore errors here - we just fallback to load wpcap.dll from default locations
}
// loadedDllPath will hold the full pathname of the loaded wpcap.dll after init if possible
var loadedDllPath = "wpcap.dll"
func initLoadedDllPath(kernel32 syscall.Handle) {
getModuleFileName, err := syscall.GetProcAddress(kernel32, "GetModuleFileNameA")
if err != nil {
// we can't get the filename of the loaded module in this case - just leave default of wpcap.dll
return
}
buf := make([]byte, 4096)
r, _, _ := syscall.Syscall(getModuleFileName, 3, uintptr(wpcapHandle), uintptr(unsafe.Pointer(&buf[0])), uintptr(len(buf)))
if r == 0 {
// we can't get the filename of the loaded module in this case - just leave default of wpcap.dll
return
}
loadedDllPath = string(buf[:int(r)])
}
func mustLoad(fun string) uintptr {
addr, err := windows.GetProcAddress(wpcapHandle, fun)
if err != nil {
panic(fmt.Sprintf("Couldn't load function %s from %s", fun, loadedDllPath))
}
return addr
}
func mightLoad(fun string) uintptr {
addr, err := windows.GetProcAddress(wpcapHandle, fun)
if err != nil {
return 0
}
return addr
}
func byteSliceToString(bval []byte) string {
for i := range bval {
if bval[i] == 0 {
return string(bval[:i])
}
}
return string(bval[:])
}
// bytePtrToString returns a string copied from pointer to a null terminated byte array
// WARNING: ONLY SAFE WITH IF r POINTS TO C MEMORY!
// govet will complain about this function for the reason stated above
func bytePtrToString(r uintptr) string {
if r == 0 {
return ""
}
bval := (*[1 << 30]byte)(unsafe.Pointer(r))
return byteSliceToString(bval[:])
}
var wpcapHandle windows.Handle
var msvcrtHandle syscall.Handle
var (
callocPtr,
pcapStrerrorPtr,
pcapStatustostrPtr,
pcapOpenLivePtr,
pcapOpenOfflinePtr,
pcapClosePtr,
pcapGeterrPtr,
pcapStatsPtr,
pcapCompilePtr,
pcapFreecodePtr,
pcapLookupnetPtr,
pcapOfflineFilterPtr,
pcapSetfilterPtr,
pcapListDatalinksPtr,
pcapFreeDatalinksPtr,
pcapDatalinkValToNamePtr,
pcapDatalinkValToDescriptionPtr,
pcapOpenDeadPtr,
pcapNextExPtr,
pcapDatalinkPtr,
pcapSetDatalinkPtr,
pcapDatalinkNameToValPtr,
pcapLibVersionPtr,
pcapFreealldevsPtr,
pcapFindalldevsPtr,
pcapSendpacketPtr,
pcapSetdirectionPtr,
pcapSnapshotPtr,
pcapTstampTypeValToNamePtr,
pcapTstampTypeNameToValPtr,
pcapListTstampTypesPtr,
pcapFreeTstampTypesPtr,
pcapSetTstampTypePtr,
pcapGetTstampPrecisionPtr,
pcapSetTstampPrecisionPtr,
pcapOpenOfflineWithTstampPrecisionPtr,
pcapHOpenOfflineWithTstampPrecisionPtr,
pcapActivatePtr,
pcapCreatePtr,
pcapSetSnaplenPtr,
pcapSetPromiscPtr,
pcapSetTimeoutPtr,
pcapCanSetRfmonPtr,
pcapSetRfmonPtr,
pcapSetBufferSizePtr,
pcapSetImmediateModePtr,
pcapHopenOfflinePtr uintptr
)
func init() {
LoadWinPCAP()
}
// LoadWinPCAP attempts to dynamically load the wpcap DLL and resolve necessary functions
func LoadWinPCAP() error {
if pcapLoaded {
return nil
}
kernel32, err := syscall.LoadLibrary("kernel32.dll")
if err != nil {
return fmt.Errorf("couldn't load kernel32.dll")
}
defer syscall.FreeLibrary(kernel32)
initDllPath(kernel32)
if haveSearch, _ := syscall.GetProcAddress(kernel32, "AddDllDirectory"); haveSearch != 0 {
// if AddDllDirectory is present, we can use LOAD_LIBRARY_* stuff with LoadLibraryEx to avoid wpcap.dll hijacking
// see: https://msdn.microsoft.com/en-us/library/ff919712%28VS.85%29.aspx
const LOAD_LIBRARY_SEARCH_USER_DIRS = 0x00000400
const LOAD_LIBRARY_SEARCH_SYSTEM32 = 0x00000800
wpcapHandle, err = windows.LoadLibraryEx("wpcap.dll", 0, LOAD_LIBRARY_SEARCH_USER_DIRS|LOAD_LIBRARY_SEARCH_SYSTEM32)
if err != nil {
return fmt.Errorf("couldn't load wpcap.dll")
}
} else {
// otherwise fall back to load it with the unsafe search cause by SetDllDirectory
wpcapHandle, err = windows.LoadLibrary("wpcap.dll")
if err != nil {
return fmt.Errorf("couldn't load wpcap.dll")
}
}
initLoadedDllPath(kernel32)
msvcrtHandle, err = syscall.LoadLibrary("msvcrt.dll")
if err != nil {
return fmt.Errorf("couldn't load msvcrt.dll")
}
callocPtr, err = syscall.GetProcAddress(msvcrtHandle, "calloc")
if err != nil {
return fmt.Errorf("couldn't get calloc function")
}
pcapStrerrorPtr = mustLoad("pcap_strerror")
pcapStatustostrPtr = mightLoad("pcap_statustostr") // not available on winpcap
pcapOpenLivePtr = mustLoad("pcap_open_live")
pcapOpenOfflinePtr = mustLoad("pcap_open_offline")
pcapClosePtr = mustLoad("pcap_close")
pcapGeterrPtr = mustLoad("pcap_geterr")
pcapStatsPtr = mustLoad("pcap_stats")
pcapCompilePtr = mustLoad("pcap_compile")
pcapFreecodePtr = mustLoad("pcap_freecode")
pcapLookupnetPtr = mustLoad("pcap_lookupnet")
pcapOfflineFilterPtr = mustLoad("pcap_offline_filter")
pcapSetfilterPtr = mustLoad("pcap_setfilter")
pcapListDatalinksPtr = mustLoad("pcap_list_datalinks")
pcapFreeDatalinksPtr = mustLoad("pcap_free_datalinks")
pcapDatalinkValToNamePtr = mustLoad("pcap_datalink_val_to_name")
pcapDatalinkValToDescriptionPtr = mustLoad("pcap_datalink_val_to_description")
pcapOpenDeadPtr = mustLoad("pcap_open_dead")
pcapNextExPtr = mustLoad("pcap_next_ex")
pcapDatalinkPtr = mustLoad("pcap_datalink")
pcapSetDatalinkPtr = mustLoad("pcap_set_datalink")
pcapDatalinkNameToValPtr = mustLoad("pcap_datalink_name_to_val")
pcapLibVersionPtr = mustLoad("pcap_lib_version")
pcapFreealldevsPtr = mustLoad("pcap_freealldevs")
pcapFindalldevsPtr = mustLoad("pcap_findalldevs")
pcapSendpacketPtr = mustLoad("pcap_sendpacket")
pcapSetdirectionPtr = mustLoad("pcap_setdirection")
pcapSnapshotPtr = mustLoad("pcap_snapshot")
//libpcap <1.2 doesn't have pcap_*_tstamp_* functions
pcapTstampTypeValToNamePtr = mightLoad("pcap_tstamp_type_val_to_name")
pcapTstampTypeNameToValPtr = mightLoad("pcap_tstamp_type_name_to_val")
pcapListTstampTypesPtr = mightLoad("pcap_list_tstamp_types")
pcapFreeTstampTypesPtr = mightLoad("pcap_free_tstamp_types")
pcapSetTstampTypePtr = mightLoad("pcap_set_tstamp_type")
pcapGetTstampPrecisionPtr = mightLoad("pcap_get_tstamp_precision")
pcapSetTstampPrecisionPtr = mightLoad("pcap_set_tstamp_precision")
pcapOpenOfflineWithTstampPrecisionPtr = mightLoad("pcap_open_offline_with_tstamp_precision")
pcapHOpenOfflineWithTstampPrecisionPtr = mightLoad("pcap_hopen_offline_with_tstamp_precision")
pcapActivatePtr = mustLoad("pcap_activate")
pcapCreatePtr = mustLoad("pcap_create")
pcapSetSnaplenPtr = mustLoad("pcap_set_snaplen")
pcapSetPromiscPtr = mustLoad("pcap_set_promisc")
pcapSetTimeoutPtr = mustLoad("pcap_set_timeout")
//winpcap does not support rfmon
pcapCanSetRfmonPtr = mightLoad("pcap_can_set_rfmon")
pcapSetRfmonPtr = mightLoad("pcap_set_rfmon")
pcapSetBufferSizePtr = mustLoad("pcap_set_buffer_size")
//libpcap <1.5 does not have pcap_set_immediate_mode
pcapSetImmediateModePtr = mightLoad("pcap_set_immediate_mode")
pcapHopenOfflinePtr = mustLoad("pcap_hopen_offline")
pcapLoaded = true
return nil
}
func (h *pcapPkthdr) getSec() int64 {
return int64(h.Ts.Sec)
}
func (h *pcapPkthdr) getUsec() int64 {
return int64(h.Ts.Usec)
}
func (h *pcapPkthdr) getLen() int {
return int(h.Len)
}
func (h *pcapPkthdr) getCaplen() int {
return int(h.Caplen)
}
func statusError(status pcapCint) error {
var ret uintptr
if pcapStatustostrPtr == 0 {
ret, _, _ = syscall.Syscall(pcapStrerrorPtr, 1, uintptr(status), 0, 0)
} else {
ret, _, _ = syscall.Syscall(pcapStatustostrPtr, 1, uintptr(status), 0, 0)
}
return errors.New(bytePtrToString(ret))
}
func pcapGetTstampPrecision(cptr pcapTPtr) int {
if pcapGetTstampPrecisionPtr == 0 {
return pcapTstampPrecisionMicro
}
ret, _, _ := syscall.Syscall(pcapGetTstampPrecisionPtr, 1, uintptr(cptr), 0, 0)
return int(pcapCint(ret))
}
func pcapSetTstampPrecision(cptr pcapTPtr, precision int) error {
if pcapSetTstampPrecisionPtr == 0 {
return errors.New("Not supported")
}
ret, _, _ := syscall.Syscall(pcapSetTstampPrecisionPtr, 2, uintptr(cptr), uintptr(precision), 0)
if pcapCint(ret) < 0 {
return errors.New("Not supported")
}
return nil
}
func pcapOpenLive(device string, snaplen int, pro int, timeout int) (*Handle, error) {
err := LoadWinPCAP()
if err != nil {
return nil, err
}
buf := make([]byte, errorBufferSize)
dev, err := syscall.BytePtrFromString(device)
if err != nil {
return nil, err
}
cptr, _, _ := syscall.Syscall6(pcapOpenLivePtr, 5, uintptr(unsafe.Pointer(dev)), uintptr(snaplen), uintptr(pro), uintptr(timeout), uintptr(unsafe.Pointer(&buf[0])), 0)
if cptr == 0 {
return nil, errors.New(byteSliceToString(buf))
}
return &Handle{cptr: pcapTPtr(cptr)}, nil
}
func openOffline(file string) (handle *Handle, err error) {
err = LoadWinPCAP()
if err != nil {
return nil, err
}
buf := make([]byte, errorBufferSize)
f, err := syscall.BytePtrFromString(file)
if err != nil {
return nil, err
}
var cptr uintptr
if pcapOpenOfflineWithTstampPrecisionPtr == 0 {
cptr, _, _ = syscall.Syscall(pcapOpenOfflinePtr, 2, uintptr(unsafe.Pointer(f)), uintptr(unsafe.Pointer(&buf[0])), 0)
} else {
cptr, _, _ = syscall.Syscall(pcapOpenOfflineWithTstampPrecisionPtr, 3, uintptr(unsafe.Pointer(f)), uintptr(pcapTstampPrecisionNano), uintptr(unsafe.Pointer(&buf[0])))
}
if cptr == 0 {
return nil, errors.New(byteSliceToString(buf))
}
h := &Handle{cptr: pcapTPtr(cptr)}
return h, nil
}
func (p *Handle) pcapClose() {
if p.cptr != 0 {
_, _, _ = syscall.Syscall(pcapClosePtr, 1, uintptr(p.cptr), 0, 0)
}
p.cptr = 0
}
func (p *Handle) pcapGeterr() error {
ret, _, _ := syscall.Syscall(pcapGeterrPtr, 1, uintptr(p.cptr), 0, 0)
return errors.New(bytePtrToString(ret))
}
func (p *Handle) pcapStats() (*Stats, error) {
var cstats pcapStats
ret, _, _ := syscall.Syscall(pcapStatsPtr, 2, uintptr(p.cptr), uintptr(unsafe.Pointer(&cstats)), 0)
if pcapCint(ret) < 0 {
return nil, p.pcapGeterr()
}
return &Stats{
PacketsReceived: int(cstats.Recv),
PacketsDropped: int(cstats.Drop),
PacketsIfDropped: int(cstats.Ifdrop),
}, nil
}
// for libpcap < 1.8 pcap_compile is NOT thread-safe, so protect it.
var pcapCompileMu sync.Mutex
func (p *Handle) pcapCompile(expr string, maskp uint32) (pcapBpfProgram, error) {
var bpf pcapBpfProgram
cexpr, err := syscall.BytePtrFromString(expr)
if err != nil {
return pcapBpfProgram{}, err
}
pcapCompileMu.Lock()
defer pcapCompileMu.Unlock()
res, _, _ := syscall.Syscall6(pcapCompilePtr, 5, uintptr(p.cptr), uintptr(unsafe.Pointer(&bpf)), uintptr(unsafe.Pointer(cexpr)), uintptr(1), uintptr(maskp), 0)
if pcapCint(res) < 0 {
return bpf, p.pcapGeterr()
}
return bpf, nil
}
func (p pcapBpfProgram) free() {
_, _, _ = syscall.Syscall(pcapFreecodePtr, 1, uintptr(unsafe.Pointer(&p)), 0, 0)
}
func (p pcapBpfProgram) toBPFInstruction() []BPFInstruction {
bpfInsn := (*[bpfInstructionBufferSize]pcapBpfInstruction)(unsafe.Pointer(p.Insns))[0:p.Len:p.Len]
bpfInstruction := make([]BPFInstruction, len(bpfInsn), len(bpfInsn))
for i, v := range bpfInsn {
bpfInstruction[i].Code = v.Code
bpfInstruction[i].Jt = v.Jt
bpfInstruction[i].Jf = v.Jf
bpfInstruction[i].K = v.K
}
return bpfInstruction
}
func pcapBpfProgramFromInstructions(bpfInstructions []BPFInstruction) pcapBpfProgram {
var bpf pcapBpfProgram
bpf.Len = uint32(len(bpfInstructions))
cbpfInsns, _, _ := syscall.Syscall(callocPtr, 2, uintptr(len(bpfInstructions)), uintptr(unsafe.Sizeof(bpfInstructions[0])), 0)
gbpfInsns := (*[bpfInstructionBufferSize]pcapBpfInstruction)(unsafe.Pointer(cbpfInsns))
for i, v := range bpfInstructions {
gbpfInsns[i].Code = v.Code
gbpfInsns[i].Jt = v.Jt
gbpfInsns[i].Jf = v.Jf
gbpfInsns[i].K = v.K
}
bpf.Insns = (*pcapBpfInstruction)(unsafe.Pointer(cbpfInsns))
return bpf
}
func pcapLookupnet(device string) (netp, maskp uint32, err error) {
err = LoadWinPCAP()
if err != nil {
return 0, 0, err
}
buf := make([]byte, errorBufferSize)
dev, err := syscall.BytePtrFromString(device)
if err != nil {
return 0, 0, err
}
e, _, _ := syscall.Syscall6(pcapLookupnetPtr, 4, uintptr(unsafe.Pointer(dev)), uintptr(unsafe.Pointer(&netp)), uintptr(unsafe.Pointer(&maskp)), uintptr(unsafe.Pointer(&buf[0])), 0, 0)
if pcapCint(e) < 0 {
return 0, 0, errors.New(byteSliceToString(buf))
}
return
}
func (b *BPF) pcapOfflineFilter(ci gopacket.CaptureInfo, data []byte) bool {
var hdr pcapPkthdr
hdr.Ts.Sec = int32(ci.Timestamp.Unix())
hdr.Ts.Usec = int32(ci.Timestamp.Nanosecond() / 1000)
hdr.Caplen = uint32(len(data)) // Trust actual length over ci.Length.
hdr.Len = uint32(ci.Length)
e, _, _ := syscall.Syscall(pcapOfflineFilterPtr, 3, uintptr(unsafe.Pointer(&b.bpf.bpf)), uintptr(unsafe.Pointer(&hdr)), uintptr(unsafe.Pointer(&data[0])))
return e != 0
}
func (p *Handle) pcapSetfilter(bpf pcapBpfProgram) error {
e, _, _ := syscall.Syscall(pcapSetfilterPtr, 2, uintptr(p.cptr), uintptr(unsafe.Pointer(&bpf)), 0)
if pcapCint(e) < 0 {
return p.pcapGeterr()
}
return nil
}
func (p *Handle) pcapListDatalinks() (datalinks []Datalink, err error) {
var dltbuf *pcapCint
ret, _, _ := syscall.Syscall(pcapListDatalinksPtr, 2, uintptr(p.cptr), uintptr(unsafe.Pointer(&dltbuf)), 0)
n := int(pcapCint(ret))
if n < 0 {
return nil, p.pcapGeterr()
}
defer syscall.Syscall(pcapFreeDatalinksPtr, 1, uintptr(unsafe.Pointer(dltbuf)), 0, 0)
datalinks = make([]Datalink, n)
dltArray := (*[1 << 28]pcapCint)(unsafe.Pointer(dltbuf))
for i := 0; i < n; i++ {
datalinks[i].Name = pcapDatalinkValToName(int((*dltArray)[i]))
datalinks[i].Description = pcapDatalinkValToDescription(int((*dltArray)[i]))
}
return datalinks, nil
}
func pcapOpenDead(linkType layers.LinkType, captureLength int) (*Handle, error) {
err := LoadWinPCAP()
if err != nil {
return nil, err
}
cptr, _, _ := syscall.Syscall(pcapOpenDeadPtr, 2, uintptr(linkType), uintptr(captureLength), 0)
if cptr == 0 {
return nil, errors.New("error opening dead capture")
}
return &Handle{cptr: pcapTPtr(cptr)}, nil
}
func (p *Handle) pcapNextPacketEx() NextError {
r, _, _ := syscall.Syscall(pcapNextExPtr, 3, uintptr(p.cptr), uintptr(unsafe.Pointer(&p.pkthdr)), uintptr(unsafe.Pointer(&p.bufptr)))
ret := pcapCint(r)
// According to https://github.com/the-tcpdump-group/libpcap/blob/1131a7c26c6f4d4772e4a2beeaf7212f4dea74ac/pcap.c#L398-L406 ,
// the return value of pcap_next_ex could be greater than 1 for success.
// Let's just make it 1 if it comes bigger than 1.
if ret > 1 {
ret = 1
}
return NextError(ret)
}
func (p *Handle) pcapDatalink() layers.LinkType {
ret, _, _ := syscall.Syscall(pcapDatalinkPtr, 1, uintptr(p.cptr), 0, 0)
return layers.LinkType(ret)
}
func (p *Handle) pcapSetDatalink(dlt layers.LinkType) error {
ret, _, _ := syscall.Syscall(pcapSetDatalinkPtr, 2, uintptr(p.cptr), uintptr(dlt), 0)
if pcapCint(ret) < 0 {
return p.pcapGeterr()
}
return nil
}
func pcapDatalinkValToName(dlt int) string {
err := LoadWinPCAP()
if err != nil {
panic(err)
}
ret, _, _ := syscall.Syscall(pcapDatalinkValToNamePtr, 1, uintptr(dlt), 0, 0)
return bytePtrToString(ret)
}
func pcapDatalinkValToDescription(dlt int) string {
err := LoadWinPCAP()
if err != nil {
panic(err)
}
ret, _, _ := syscall.Syscall(pcapDatalinkValToDescriptionPtr, 1, uintptr(dlt), 0, 0)
return bytePtrToString(ret)
}
func pcapDatalinkNameToVal(name string) int {
err := LoadWinPCAP()
if err != nil {
panic(err)
}
cptr, err := syscall.BytePtrFromString(name)
if err != nil {
return 0
}
ret, _, _ := syscall.Syscall(pcapDatalinkNameToValPtr, 1, uintptr(unsafe.Pointer(cptr)), 0, 0)
return int(pcapCint(ret))
}
func pcapLibVersion() string {
err := LoadWinPCAP()
if err != nil {
panic(err)
}
ret, _, _ := syscall.Syscall(pcapLibVersionPtr, 0, 0, 0, 0)
return bytePtrToString(ret)
}
func (p *Handle) isOpen() bool {
return p.cptr != 0
}
type pcapDevices struct {
all, cur *pcapIf
}
func (p pcapDevices) free() {
syscall.Syscall(pcapFreealldevsPtr, 1, uintptr(unsafe.Pointer(p.all)), 0, 0)
}
func (p *pcapDevices) next() bool {
if p.cur == nil {
p.cur = p.all
if p.cur == nil {
return false
}
return true
}
if p.cur.Next == nil {
return false
}
p.cur = p.cur.Next
return true
}
func (p pcapDevices) name() string {
return bytePtrToString(uintptr(unsafe.Pointer(p.cur.Name)))
}
func (p pcapDevices) description() string {
return bytePtrToString(uintptr(unsafe.Pointer(p.cur.Description)))
}
func (p pcapDevices) flags() uint32 {
return p.cur.Flags
}
type pcapAddresses struct {
all, cur *pcapAddr
}
func (p *pcapAddresses) next() bool {
if p.cur == nil {
p.cur = p.all
if p.cur == nil {
return false
}
return true
}
if p.cur.Next == nil {
return false
}
p.cur = p.cur.Next
return true
}
func (p pcapAddresses) addr() *syscall.RawSockaddr {
return p.cur.Addr
}
func (p pcapAddresses) netmask() *syscall.RawSockaddr {
return p.cur.Netmask
}
func (p pcapAddresses) broadaddr() *syscall.RawSockaddr {
return p.cur.Broadaddr
}
func (p pcapAddresses) dstaddr() *syscall.RawSockaddr {
return p.cur.Dstaddr
}
func (p pcapDevices) addresses() pcapAddresses {
return pcapAddresses{all: p.cur.Addresses}
}
func pcapFindAllDevs() (pcapDevices, error) {
var alldevsp pcapDevices
err := LoadWinPCAP()
if err != nil {
return alldevsp, err
}
buf := make([]byte, errorBufferSize)
ret, _, _ := syscall.Syscall(pcapFindalldevsPtr, 2, uintptr(unsafe.Pointer(&alldevsp.all)), uintptr(unsafe.Pointer(&buf[0])), 0)
if pcapCint(ret) < 0 {
return pcapDevices{}, errors.New(byteSliceToString(buf))
}
return alldevsp, nil
}
func (p *Handle) pcapSendpacket(data []byte) error {
ret, _, _ := syscall.Syscall(pcapSendpacketPtr, 3, uintptr(p.cptr), uintptr(unsafe.Pointer(&data[0])), uintptr(len(data)))
if pcapCint(ret) < 0 {
return p.pcapGeterr()
}
return nil
}
func (p *Handle) pcapSetdirection(direction Direction) error {
status, _, _ := syscall.Syscall(pcapSetdirectionPtr, 2, uintptr(p.cptr), uintptr(direction), 0)
if pcapCint(status) < 0 {
return statusError(pcapCint(status))
}
return nil
}
func (p *Handle) pcapSnapshot() int {
ret, _, _ := syscall.Syscall(pcapSnapshotPtr, 1, uintptr(p.cptr), 0, 0)
return int(pcapCint(ret))
}
func (t TimestampSource) pcapTstampTypeValToName() string {
err := LoadWinPCAP()
if err != nil {
return err.Error()
}
//libpcap <1.2 doesn't have pcap_*_tstamp_* functions
if pcapTstampTypeValToNamePtr == 0 {
return "pcap timestamp types not supported"
}
ret, _, _ := syscall.Syscall(pcapTstampTypeValToNamePtr, 1, uintptr(t), 0, 0)
return bytePtrToString(ret)
}
func pcapTstampTypeNameToVal(s string) (TimestampSource, error) {
err := LoadWinPCAP()
if err != nil {
return 0, err
}
//libpcap <1.2 doesn't have pcap_*_tstamp_* functions
if pcapTstampTypeNameToValPtr == 0 {
return 0, statusError(pcapCint(pcapError))
}
cs, err := syscall.BytePtrFromString(s)
if err != nil {
return 0, err
}
ret, _, _ := syscall.Syscall(pcapTstampTypeNameToValPtr, 1, uintptr(unsafe.Pointer(cs)), 0, 0)
t := pcapCint(ret)
if t < 0 {
return 0, statusError(pcapCint(t))
}
return TimestampSource(t), nil
}
func (p *InactiveHandle) pcapGeterr() error {
ret, _, _ := syscall.Syscall(pcapGeterrPtr, 1, uintptr(p.cptr), 0, 0)
return errors.New(bytePtrToString(ret))
}
func (p *InactiveHandle) pcapActivate() (*Handle, activateError) {
r, _, _ := syscall.Syscall(pcapActivatePtr, 1, uintptr(p.cptr), 0, 0)
ret := activateError(pcapCint(r))
if ret != aeNoError {
return nil, ret
}
h := &Handle{
cptr: p.cptr,
}
p.cptr = 0
return h, ret
}
func (p *InactiveHandle) pcapClose() {
if p.cptr != 0 {
_, _, _ = syscall.Syscall(pcapClosePtr, 1, uintptr(p.cptr), 0, 0)
}
p.cptr = 0
}
func pcapCreate(device string) (*InactiveHandle, error) {
err := LoadWinPCAP()
if err != nil {
return nil, err
}
buf := make([]byte, errorBufferSize)
dev, err := syscall.BytePtrFromString(device)
if err != nil {
return nil, err
}
cptr, _, _ := syscall.Syscall(pcapCreatePtr, 2, uintptr(unsafe.Pointer(dev)), uintptr(unsafe.Pointer(&buf[0])), 0)
if cptr == 0 {
return nil, errors.New(byteSliceToString(buf))
}
return &InactiveHandle{cptr: pcapTPtr(cptr)}, nil
}
func (p *InactiveHandle) pcapSetSnaplen(snaplen int) error {
status, _, _ := syscall.Syscall(pcapSetSnaplenPtr, 2, uintptr(p.cptr), uintptr(snaplen), 0)
if pcapCint(status) < 0 {
return statusError(pcapCint(status))
}
return nil
}
func (p *InactiveHandle) pcapSetPromisc(promisc bool) error {
var pro uintptr
if promisc {
pro = 1
}
status, _, _ := syscall.Syscall(pcapSetPromiscPtr, 2, uintptr(p.cptr), pro, 0)
if pcapCint(status) < 0 {
return statusError(pcapCint(status))
}
return nil
}
func (p *InactiveHandle) pcapSetTimeout(timeout time.Duration) error {
status, _, _ := syscall.Syscall(pcapSetTimeoutPtr, 2, uintptr(p.cptr), uintptr(timeoutMillis(timeout)), 0)
if pcapCint(status) < 0 {
return statusError(pcapCint(status))
}
return nil
}
func (p *InactiveHandle) pcapListTstampTypes() (out []TimestampSource) {
//libpcap <1.2 doesn't have pcap_*_tstamp_* functions
if pcapListTstampTypesPtr == 0 {
return
}
var types *pcapCint
ret, _, _ := syscall.Syscall(pcapListTstampTypesPtr, 2, uintptr(p.cptr), uintptr(unsafe.Pointer(&types)), 0)
n := int(pcapCint(ret))
if n < 0 {
return // public interface doesn't have error :(
}
defer syscall.Syscall(pcapFreeTstampTypesPtr, 1, uintptr(unsafe.Pointer(types)), 0, 0)
typesArray := (*[1 << 28]pcapCint)(unsafe.Pointer(types))
for i := 0; i < n; i++ {
out = append(out, TimestampSource((*typesArray)[i]))
}
return
}
func (p *InactiveHandle) pcapSetTstampType(t TimestampSource) error {
//libpcap <1.2 doesn't have pcap_*_tstamp_* functions
if pcapSetTstampTypePtr == 0 {
return statusError(pcapError)
}
status, _, _ := syscall.Syscall(pcapSetTstampTypePtr, 2, uintptr(p.cptr), uintptr(t), 0)
if pcapCint(status) < 0 {
return statusError(pcapCint(status))
}
return nil
}
func (p *InactiveHandle) pcapSetRfmon(monitor bool) error {
//winpcap does not support rfmon
if pcapCanSetRfmonPtr == 0 {
return CannotSetRFMon
}
var mon uintptr
if monitor {
mon = 1
}
canset, _, _ := syscall.Syscall(pcapCanSetRfmonPtr, 1, uintptr(p.cptr), 0, 0)
switch canset {
case 0:
return CannotSetRFMon
case 1:
// success
default:
return statusError(pcapCint(canset))
}
status, _, _ := syscall.Syscall(pcapSetRfmonPtr, 2, uintptr(p.cptr), mon, 0)
if status != 0 {
return statusError(pcapCint(status))
}
return nil
}
func (p *InactiveHandle) pcapSetBufferSize(bufferSize int) error {
status, _, _ := syscall.Syscall(pcapSetBufferSizePtr, 2, uintptr(p.cptr), uintptr(bufferSize), 0)
if pcapCint(status) < 0 {
return statusError(pcapCint(status))
}
return nil
}
func (p *InactiveHandle) pcapSetImmediateMode(mode bool) error {
//libpcap <1.5 does not have pcap_set_immediate_mode
if pcapSetImmediateModePtr == 0 {
return statusError(pcapError)
}
var md uintptr
if mode {
md = 1
}
status, _, _ := syscall.Syscall(pcapSetImmediateModePtr, 2, uintptr(p.cptr), md, 0)
if pcapCint(status) < 0 {
return statusError(pcapCint(status))
}
return nil
}
func (p *Handle) setNonBlocking() error {
// do nothing
return nil
}
// waitForPacket waits for a packet or for the timeout to expire.
func (p *Handle) waitForPacket() {
// can't use select() so instead just switch goroutines
runtime.Gosched()
}
// openOfflineFile returns contents of input file as a *Handle.
func openOfflineFile(file *os.File) (handle *Handle, err error) {
err = LoadWinPCAP()
if err != nil {
return nil, err
}
buf := make([]byte, errorBufferSize)
cf := file.Fd()
var cptr uintptr
if pcapOpenOfflineWithTstampPrecisionPtr == 0 {
cptr, _, _ = syscall.Syscall(pcapHopenOfflinePtr, 2, cf, uintptr(unsafe.Pointer(&buf[0])), 0)
} else {
cptr, _, _ = syscall.Syscall(pcapHOpenOfflineWithTstampPrecisionPtr, 3, cf, uintptr(pcapTstampPrecisionNano), uintptr(unsafe.Pointer(&buf[0])))
}
if cptr == 0 {
return nil, errors.New(byteSliceToString(buf))
}
return &Handle{cptr: pcapTPtr(cptr)}, nil
}
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