func (t *Listener) readRAWSocket() {
// AF_INET can't capture outgoing packets, must change to use AF_PACKET
// https://github.com/golang/go/issues/7653
// http://www.binarytides.com/packet-sniffer-code-in-c-using-linux-sockets-bsd-part-2/
proto := (syscall.ETH_P_ALL<<8)&0xff00 | syscall.ETH_P_ALL>>8 // change to Big-Endian order
fd, err := syscall.Socket(syscall.AF_PACKET, syscall.SOCK_RAW, proto)
if err != nil {
log.Fatal("socket: ", err)
}
defer syscall.Close(fd)
if t.addr != "" && t.addr != "0.0.0.0" {
ifi, err := net.InterfaceByName(t.addr)
if err != nil {
log.Fatal("interfacebyname: ", err)
}
lla := syscall.SockaddrLinklayer{Protocol: uint16(proto), Ifindex: ifi.Index}
if err := syscall.Bind(fd, &lla); err != nil {
log.Fatal("bind: ", err)
}
}
var src_ip string
var dest_ip string
buf := make([]byte, 65536)
for {
n, _, err := syscall.Recvfrom(fd, buf, 0)
if err != nil {
log.Println("Error:", err)
continue
}
if n <= 0 {
continue
}
packet := gopacket.NewPacket(buf[:n], layers.LayerTypeEthernet, gopacket.Default)
if tcpLayer := packet.Layer(layers.LayerTypeTCP); tcpLayer != nil {
tcp, _ := tcpLayer.(*layers.TCP)
src_ip = packet.NetworkLayer().NetworkFlow().Src().String()
dest_ip = packet.NetworkLayer().NetworkFlow().Dst().String()
t.parsePacket(src_ip, dest_ip, tcp)
}
}
}
func (w *Watcher) readAllEvents() {
buf := make([]byte, syscall.Getpagesize())
listener, _ := w.listener.(*netlinkListener)
for {
if w.isDone() {
return
}
nr, _, err := syscall.Recvfrom(listener.sock, buf, 0)
if err != nil {
w.Error <- err
continue
}
if nr < syscall.NLMSG_HDRLEN {
w.Error <- syscall.EINVAL
continue
}
msgs, _ := syscall.ParseNetlinkMessage(buf[:nr])
for _, m := range msgs {
if m.Header.Type == syscall.NLMSG_DONE {
w.handleEventAll(m.Data)
}
}
}
}
func (fd *netFD) ReadFrom(p []byte) (n int, sa syscall.Sockaddr, err error) {
fd.rio.Lock()
defer fd.rio.Unlock()
if err := fd.incref(false); err != nil {
return 0, nil, err
}
defer fd.decref()
for {
n, sa, err = syscall.Recvfrom(fd.sysfd, p, 0)
if err == syscall.EAGAIN {
err = errTimeout
if fd.rdeadline >= 0 {
if err = fd.pollServer.WaitRead(fd); err == nil {
continue
}
}
}
if err != nil {
n = 0
}
break
}
if err != nil && err != io.EOF {
err = &OpError{"read", fd.net, fd.laddr, err}
}
return
}
func (nlSock *NLSocket) recv() ([]GNLMessage, error) {
buff := make([]byte, 16384)
var msgsList []GNLMessage
for {
n, _, err := syscall.Recvfrom(nlSock.Sd, buff, 0)
if err != nil {
return nil, err
}
resp := buff[:n]
for len(resp) > 0 {
rmsg, data, err := DeserializeNLMsg(resp)
if err != nil {
return nil, err
}
if len(msgsList) == 0 && rmsg.Flags&0x2 == 0 {
return []GNLMessage{rmsg}, nil
} else if rmsg.Family == DoneMessageType {
return msgsList, nil
}
msgsList = append(msgsList, rmsg)
resp = data
}
}
return msgsList, nil
}
func (fd *netFD) ReadFrom(p []byte) (n int, sa syscall.Sockaddr, err os.Error) {
if fd == nil || fd.sysfile == nil {
return 0, nil, os.EINVAL
}
fd.rio.Lock()
defer fd.rio.Unlock()
fd.incref()
defer fd.decref()
if fd.rdeadline_delta > 0 {
fd.rdeadline = pollserver.Now() + fd.rdeadline_delta
} else {
fd.rdeadline = 0
}
var oserr os.Error
for {
var errno int
n, sa, errno = syscall.Recvfrom(fd.sysfd, p, 0)
if errno == syscall.EAGAIN && fd.rdeadline >= 0 {
pollserver.WaitRead(fd)
continue
}
if errno != 0 {
n = 0
oserr = os.Errno(errno)
}
break
}
if oserr != nil {
err = &OpError{"read", fd.net, fd.laddr, oserr}
}
return
}
func (fd *netFD) ReadFrom(p []byte) (n int, sa syscall.Sockaddr, err error) {
if err := fd.readLock(); err != nil {
return 0, nil, err
}
defer fd.readUnlock()
if err := fd.pd.PrepareRead(); err != nil {
return 0, nil, &OpError{"read", fd.net, fd.laddr, err}
}
for {
n, sa, err = syscall.Recvfrom(fd.sysfd, p, 0)
if err != nil {
n = 0
if err == syscall.EAGAIN {
if err = fd.pd.WaitRead(); err == nil {
continue
}
}
}
err = chkReadErr(n, err, fd)
break
}
if err != nil && err != io.EOF {
err = &OpError{"read", fd.net, fd.laddr, err}
}
return
}
func (fd *netFD) ReadFrom(p []byte) (n int, sa syscall.Sockaddr, err error) {
if fd == nil || fd.sysfile == nil {
return 0, nil, os.EINVAL
}
fd.rio.Lock()
defer fd.rio.Unlock()
fd.incref()
defer fd.decref()
for {
n, sa, err = syscall.Recvfrom(fd.sysfd, p, 0)
if err == syscall.EAGAIN {
if fd.rdeadline >= 0 {
pollserver.WaitRead(fd)
continue
}
err = errTimeout
}
if err != nil {
n = 0
}
break
}
if err != nil {
err = &OpError{"read", fd.net, fd.laddr, err}
}
return
}
func (fd *netFD) readFrom(p []byte) (n int, sa syscall.Sockaddr, err error) {
if err := fd.readLock(); err != nil {
return 0, nil, err
}
defer fd.readUnlock()
if err := fd.pd.prepareRead(); err != nil {
return 0, nil, err
}
for {
n, sa, err = syscall.Recvfrom(fd.sysfd, p, 0)
if err != nil {
n = 0
if err == syscall.EAGAIN {
if err = fd.pd.waitRead(); err == nil {
continue
}
}
}
err = fd.eofError(n, err)
break
}
if _, ok := err.(syscall.Errno); ok {
err = os.NewSyscallError("recvfrom", err)
}
return
}
// Receives messages from Kernel and forwards to channels
func Getreply(s *NetlinkSocket, done <-chan bool, msgchan chan string, errchan chan error) {
for {
rb := make([]byte, MAX_AUDIT_MESSAGE_LENGTH)
nr, _, err := syscall.Recvfrom(s.fd, rb, 0)
if isDone(msgchan, errchan, done) {
return
}
if err != nil {
log.Println("Error While Recieving !!")
errchan <- err
continue
}
if nr < syscall.NLMSG_HDRLEN {
log.Println("Message Too Short!!")
errchan <- syscall.EINVAL
continue
}
rb = rb[:nr]
msgs, err := ParseAuditNetlinkMessage(rb)
if err != nil {
log.Println("Not Parsed Successfuly !!")
errchan <- err
continue
}
for _, m := range msgs {
//Decide on various message Types
//Add more message Types
if m.Header.Type == syscall.NLMSG_DONE {
log.Println("Done")
} else if m.Header.Type == syscall.NLMSG_ERROR {
err := int32(nativeEndian().Uint32(m.Data[0:4]))
if err == 0 {
//Acknowledgement from kernel
log.Println("Ack")
} else {
log.Println("NLMSG_ERROR")
}
} else if m.Header.Type == AUDIT_GET {
log.Println("AUDIT_GET")
} else if m.Header.Type == AUDIT_FIRST_USER_MSG {
log.Println("AUDIT_FIRST_USER_MSG")
} else if m.Header.Type == AUDIT_SYSCALL {
msgchan <- ("type=SYSCALL " + "msg=" + string(m.Data[:]))
} else if m.Header.Type == AUDIT_CWD {
msgchan <- ("type=CWD " + "msg=" + string(m.Data[:]))
} else if m.Header.Type == AUDIT_PATH {
msgchan <- ("type=PATH " + "msg=" + string(m.Data[:]))
} else if m.Header.Type == AUDIT_EOE {
// log.Println("Event Ends ", string(m.Data[:]))
} else if m.Header.Type == AUDIT_CONFIG_CHANGE {
msgchan <- ("type=CONFIG_CHANGE " + "msg=" + string(m.Data[:]))
} else {
log.Println("Unknown: ", m.Header.Type)
}
}
}
}
func (nl *NetlinkSocket) RecvMessages(sz, sockflags int) ([]NetlinkMessage, error) {
buf := make([]byte, sz)
rsz, _, err := syscall.Recvfrom(nl.sfd, buf, sockflags)
if err != nil {
return nil, err
}
if rsz < syscall.NLMSG_HDRLEN {
return nil, syscall.EINVAL
}
msgList, err := syscall.ParseNetlinkMessage(buf[:rsz])
if err != nil {
return nil, err
}
ret := []NetlinkMessage{}
for _, msg := range msgList {
msg := NetlinkMessage(msg)
logf("received: %+v\n", msg)
ret = append(ret, msg)
}
return ret, nil
}
func traceOne(addr *syscall.SockaddrInet4, ttl int) *ReturnArgs {
cli, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_DGRAM, syscall.IPPROTO_UDP)
if err != nil {
exitWithError(err)
}
srv, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_RAW, syscall.IPPROTO_ICMP)
if err != nil {
exitWithError(err)
}
defer syscall.Close(cli)
defer syscall.Close(srv)
// set ttl, stolen from somewhere else...
// https://github.com/aeden/traceroute/blob/master/traceroute.go#L195
if err := syscall.SetsockoptInt(cli, syscall.SOL_IP, syscall.IP_TTL, ttl); err != nil {
exitWithError(err)
}
// set timeout, stolen from somewhere else...
// https://github.com/aeden/traceroute/blob/master/traceroute.go#L197
tv := syscall.NsecToTimeval(1e6 * TIMEOUT)
if err := syscall.SetsockoptTimeval(srv, syscall.SOL_SOCKET, syscall.SO_RCVTIMEO, &tv); err != nil {
exitWithError(err)
}
if err := syscall.Bind(srv, toAddr(HOST, RECV_PORT)); err != nil {
exitWithError(err)
}
rr := &ReturnArgs{}
start := time.Now()
if err := syscall.Sendto(cli, makeICMP(), 0, addr); err != nil {
return rr
}
buf := make([]byte, 512)
_, from, err := syscall.Recvfrom(srv, buf, 0)
if err != nil {
return rr
}
rr.elapsed = float64(time.Since(start).Nanoseconds()) / 1e6
t, c := parseICMP(buf)
if t == 3 && c == 3 { // Destination port unreachable, type==3 && code==3
rr.done = true
} else if t != 11 { // Time Exceeded, type==11 && code in (0,1)
return rr
}
rr.ok = true
rr.ip = toStr(from)
addrs, err := net.LookupAddr(rr.ip)
if err != nil {
rr.addr = rr.ip
} else {
rr.addr = addrs[0]
}
return rr
}
// Traceroute executes traceroute to given destination, using options from TracerouteOptions
// and sending updates to chan c
//
// Outbound packets are UDP packets and inbound packets are ICMP.
//
// Returns an error or nil if no error occurred
func Traceroute(dest *net.IPAddr, options *TracerouteOptions, c chan TraceUpdate) (err error) {
var destAddr [4]byte
copy(destAddr[:], dest.IP.To4())
socketAddr, err := getSocketAddr()
if err != nil {
return
}
timeoutMs := (int64)(options.TimeoutMs)
tv := syscall.NsecToTimeval(1000 * 1000 * timeoutMs)
ttl := 1
for {
// Set up receiving socket
recvSocket, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_RAW, syscall.IPPROTO_ICMP)
if err != nil {
log.Fatal("Cannot setup receive socket, please run as root or with CAP_NET_RAW permissions")
return err
}
// Set up sending socket
sendSocket, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_DGRAM, syscall.IPPROTO_UDP)
if err != nil {
log.Fatal("Cannot setup sending socket")
return err
}
start := time.Now()
syscall.SetsockoptInt(sendSocket, 0x0, syscall.IP_TTL, ttl)
syscall.SetsockoptTimeval(recvSocket, syscall.SOL_SOCKET, syscall.SO_RCVTIMEO, &tv)
syscall.Bind(recvSocket, &syscall.SockaddrInet4{Port: options.Port, Addr: socketAddr})
syscall.Sendto(sendSocket, []byte{0x0}, 0, &syscall.SockaddrInet4{Port: options.Port, Addr: destAddr})
var p = make([]byte, options.PacketSize)
n, from, err := syscall.Recvfrom(recvSocket, p, 0)
elapsed := time.Since(start)
if err == nil {
currAddr := from.(*syscall.SockaddrInet4).Addr
hop := TraceUpdate{Success: true, Address: currAddr, N: n, ElapsedTime: elapsed, TTL: ttl}
currHost, err := net.LookupAddr(hop.addressString())
if err == nil {
hop.Host = currHost[0]
}
// Send update
c <- hop
ttl += 1
// We reached the destination
if ttl > options.MaxTTL || currAddr == destAddr {
ttl = 1
}
} else {
c <- TraceUpdate{Success: false, TTL: ttl}
ttl += 1
}
syscall.Close(recvSocket)
syscall.Close(sendSocket)
}
}
func receiveICMP(result chan icmpEvent) {
// Set up the socket to receive inbound packets
sock, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_RAW, syscall.IPPROTO_ICMP)
if err != nil {
result <- makeICMPErrorEvent(&icmpEvent{}, fmt.Errorf("%v. Did you forget to run as root?", err))
return
}
err = syscall.Bind(sock, &syscall.SockaddrInet4{})
if err != nil {
result <- makeICMPErrorEvent(&icmpEvent{}, err)
return
}
var pkt = make([]byte, 1024)
for {
event := icmpEvent{}
_, from, err := syscall.Recvfrom(sock, pkt, 0)
if err != nil {
result <- makeICMPErrorEvent(&event, err)
return
}
reader := bytes.NewReader(pkt)
var ip IPHeader
var icmp ICMPHeader
var tcp TCPHeader
err = binary.Read(reader, binary.BigEndian, &ip)
if ip.Protocol != syscall.IPPROTO_ICMP {
break
}
ipheaderlen := (ip.VerHdrLen & 0xf) * 4
reader = bytes.NewReader(pkt[ipheaderlen:])
err = binary.Read(reader, binary.BigEndian, &icmp)
if icmp.Type != 11 || icmp.Code != 0 {
break
}
err = binary.Read(reader, binary.BigEndian, &ip)
if ip.Protocol != syscall.IPPROTO_TCP {
break
}
err = binary.Read(reader, binary.BigEndian, &tcp)
event.localAddr.IP = append(event.localAddr.IP, ip.SourceIP[:]...)
event.localPort = int(tcp.SrcPort)
// fill in the remote endpoint deatils on the event struct
event.remoteAddr, _, _ = ToIPAddrAndPort(from)
result <- makeICMPEvent(&event, icmpTTLExpired)
}
}
// Receives messages from Kernel and forwards to channels
func Getreply(s *NetlinkSocket, done <-chan bool, msgchan chan string, errchan chan error) {
for {
rb := make([]byte, MAX_AUDIT_MESSAGE_LENGTH)
nr, _, err := syscall.Recvfrom(s.fd, rb, 0)
if isDone(msgchan, errchan, done) {
return
}
if err != nil {
log.Println("Error While Recieving !!")
errchan <- err
continue
}
if nr < syscall.NLMSG_HDRLEN {
log.Println("Message Too Short!!")
errchan <- syscall.EINVAL
continue
}
rb = rb[:nr]
msgs, err := ParseAuditNetlinkMessage(rb)
if err != nil {
log.Println("Not Parsed Successfuly !!")
errchan <- err
continue
}
for _, m := range msgs {
//Decide on various message Types
if m.Header.Type == syscall.NLMSG_DONE {
log.Println("Done")
} else if m.Header.Type == syscall.NLMSG_ERROR {
err := int32(nativeEndian().Uint32(m.Data[0:4]))
if err == 0 {
//Acknowledgement from kernel
log.Println("Ack")
} else {
log.Println("NLMSG_ERROR")
}
} else if m.Header.Type == uint16(AUDIT_EOE) {
// log.Println("Event Ends ", string(m.Data[:]))
} else if m.Header.Type == uint16(AUDIT_GET) {
log.Println("AUDIT_GET")
} else if m.Header.Type == uint16(AUDIT_FIRST_USER_MSG) {
log.Println("AUDIT_FIRST_USER_MSG")
} else {
Type := auditConstant(m.Header.Type)
if Type.String() == "auditConstant("+strconv.Itoa(int(m.Header.Type))+")" {
log.Println("Unknown: ", m.Header.Type)
} else {
msgchan <- ("type=" + Type.String()[6:] + " msg=" + string(m.Data[:]))
}
}
}
}
}
func receive() (arpDatagram, time.Time, error) {
buffer := make([]byte, 128)
n, _, err := syscall.Recvfrom(sock, buffer, 0)
if err != nil {
return arpDatagram{}, time.Now(), err
}
// skip 14 bytes ethernet header
return parseArpDatagram(buffer[14:n]), time.Now(), nil
}
func (nl *NetlinkSocket) RecvMessagesRaw(sz, sockflags int) ([]byte, error) {
buf := make([]byte, sz)
rsz, _, err := syscall.Recvfrom(nl.sfd, buf, sockflags)
if err != nil {
return nil, err
}
return buf[:rsz], nil
}
func Hop(port, ttl int, IP_addr net.IP) (*Hop_ret, error) {
ret_addr := net.IPv4(0, 0, 0, 0)
success := false
// make sockets
send_udp_s, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_DGRAM, syscall.IPPROTO_UDP)
if err != nil {
return nil, err
}
recv_icmp_s, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_RAW, syscall.IPPROTO_ICMP)
if err != nil {
return nil, err
}
//editing TTL value for outgoing IPv4 packets
if err := syscall.SetsockoptInt(send_udp_s, syscall.SOL_IP, syscall.IP_TTL, ttl); err != nil {
return nil, err
}
tv := syscall.NsecToTimeval(1000 * 1000 * TIME_OUT_MS)
syscall.SetsockoptTimeval(recv_icmp_s, syscall.SOL_SOCKET, syscall.SO_RCVTIMEO, &tv)
defer syscall.Close(send_udp_s)
defer syscall.Close(recv_icmp_s)
//connect sockets
if err := syscall.Bind(recv_icmp_s, &syscall.SockaddrInet4{Port: port, Addr: [4]byte{137, 224, 226, 47}}); err != nil {
return nil, err
}
//send udp-packet
var IP [4]byte
copy(IP[:], IP_addr.To4())
if err := syscall.Sendto(send_udp_s, []byte{0x42, 0x42}, 0, &syscall.SockaddrInet4{Port: 1337, Addr: IP}); err != nil {
return nil, err
}
//receive ICMP
recv_buffer := make([]byte, 4096)
_, _, err = syscall.Recvfrom(recv_icmp_s, recv_buffer, 0)
if err == nil {
header, err := ipv4.ParseHeader(recv_buffer)
if err != nil {
log.Errorf("%q", err)
}
success = true
ret_addr = header.Src
} else {
//time out
success = false
ret_addr = net.IPv4(0, 0, 0, 0)
//log.Errorf("%q", err)
}
//resolve (timeout) errors, retry or return false...
return &Hop_ret{Addr: ret_addr, TTL: ttl, success: success}, nil
}
func main() {
flag.Parse()
args := flag.Args()
if flag.NArg() != 1 {
usage()
}
f, err := os.Create(args[0])
if err != nil {
log.Fatal(err)
}
defer func() {
if err := f.Close(); err != nil {
log.Fatal(err)
}
}()
pw := pcap.NewWriter(f)
defer func() {
if err := pw.Close(); err != nil {
log.Fatal(err)
}
}()
hdr := &pcap.Header{
SnapLen: maxSnapLen,
LinkType: pcap.LINKTYPE_ETHERNET,
}
if err := pw.WriteHeader(hdr); err != nil {
log.Fatal(err)
}
fd, err := syscall.Socket(syscall.AF_PACKET, syscall.SOCK_RAW, htons(syscall.ETH_P_ALL))
if err != nil {
log.Fatal(err)
}
var buf [maxSnapLen]byte
for {
n, _, err := syscall.Recvfrom(fd, buf[:], 0)
if err != nil {
log.Fatal(err)
}
sec, usec := currTime()
record := &pcap.RecordHeader{TsSec: uint32(sec), TsUsec: uint32(usec), CapLen: uint32(n), Len: uint32(n)}
if err := pw.WriteRecordHeader(record); err != nil {
log.Fatal(err)
}
if _, err = pw.Write(buf[:n]); err != nil {
log.Fatal(err)
}
}
}
func NewRtHub() (*RtHub, error) {
self := &RtHub{
sock: NlSocketAlloc(),
lock: &sync.Mutex{},
unilock: &sync.Mutex{},
multicast: make(map[uint32][]NetlinkListener),
}
if err := NlConnect(self.sock, syscall.NETLINK_ROUTE); err != nil {
NlSocketFree(self.sock)
return nil, err
}
go func() {
for {
buf := make([]byte, syscall.Getpagesize())
if n, _, err := syscall.Recvfrom(self.sock.Fd, buf, syscall.MSG_TRUNC); err != nil {
if e, ok := err.(syscall.Errno); ok && e.Temporary() {
continue
}
break
} else if msgs, err := syscall.ParseNetlinkMessage(buf[:n]); err != nil {
break
} else {
for _, msg := range msgs {
multi := func() []NetlinkListener {
self.lock.Lock()
defer self.lock.Unlock()
var ret []NetlinkListener
for _, s := range self.multicast {
ret = append(ret, s...)
}
return ret
}()
if msg.Header.Seq == self.uniseq {
if self.unicast != nil {
self.unicast.NetlinkListen(msg)
}
switch msg.Header.Type {
case syscall.NLMSG_DONE, syscall.NLMSG_ERROR:
self.unilock.Unlock()
}
}
if msg.Header.Seq == 0 {
for _, proc := range multi {
proc.NetlinkListen(msg)
}
}
}
}
}
log.Print("rt hub loop exit")
}()
return self, nil
}
func (k *PosixKernel) Recvfrom(fd co.Fd, buf co.Buf, size co.Len, flags int, from co.Buf, fromlen co.Len) uint64 {
p := make([]byte, size)
if n, _, err := syscall.Recvfrom(int(fd), p, flags); err != nil {
// TODO: need kernel.Pack() so we can pack a sockaddr into from
if err := buf.Pack(p); err != nil {
return UINT64_MAX // FIXME
}
return uint64(n)
} else {
return UINT64_MAX // FIXME
}
}
func (s *NetlinkSocket) Receive() ([]syscall.NetlinkMessage, error) {
rb := make([]byte, syscall.Getpagesize())
nr, _, err := syscall.Recvfrom(s.fd, rb, 0)
if err != nil {
return nil, err
}
if nr < syscall.NLMSG_HDRLEN {
return nil, ErrShortResponse
}
rb = rb[:nr]
return syscall.ParseNetlinkMessage(rb)
}
func (w *Worker) recvPacket(socket int) ([]byte, int) {
//time.Sleep(time.Duration(time.Millisecond * 100))
RecvBuf := make([]byte, 52)
var RecvLen int
//var from net.TCPAddr
var RecvErr error
RecvLen, _, RecvErr = syscall.Recvfrom(socket, RecvBuf, 0)
if RecvErr != nil {
fmt.Printf("%s", RecvErr.Error())
}
return RecvBuf, RecvLen
}
func (self *NetLinkSocket) Receive() (*ProcEvent, error) {
rb := make([]byte, 76)
nr, _, err := syscall.Recvfrom(self.fd, rb, 0)
if err != nil {
return nil, err
}
if nr < syscall.NLMSG_HDRLEN {
return nil, ErrShortResponse
}
rb = rb[:nr]
return parseProcEvent(rb)
}
// Receive is a wrapper for recieving from netlink socket and return an array of NetlinkMessage
func (s *NetlinkConnection) Receive(bytesize int, block int) ([]NetlinkMessage, error) {
rb := make([]byte, bytesize)
nr, _, err := syscall.Recvfrom(s.fd, rb, 0|block)
if err != nil {
return nil, errors.Wrap(err, "recvfrom failed")
}
if nr < syscall.NLMSG_HDRLEN {
return nil, errors.Wrap(err, "message length shorter than expected")
}
rb = rb[:nr]
return parseAuditNetlinkMessage(rb)
}
// Wrapper for Recvfrom
func (s *NetlinkConnection) Receive(bytesize int, block int) ([]NetlinkMessage, error) {
rb := make([]byte, bytesize)
nr, _, err := syscall.Recvfrom(s.fd, rb, 0|block)
if err != nil {
return nil, err
}
if nr < syscall.NLMSG_HDRLEN {
return nil, syscall.EINVAL
}
rb = rb[:nr]
return parseAuditNetlinkMessage(rb)
}
// ReadFromUnix reads a packet from c, copying the payload into b.
// It returns the number of bytes copied into b and the return address
// that was on the packet.
//
// ReadFromUnix can be made to time out and return err == os.EAGAIN
// after a fixed time limit; see SetTimeout and SetReadTimeout.
func (c *UnixConn) ReadFromUnix(b []byte) (n int, addr *UnixAddr, err os.Error) {
if !c.ok() {
return 0, nil, os.EINVAL
}
n, sa, errno := syscall.Recvfrom(c.fd.fd, b, 0)
if errno != 0 {
err = os.Errno(errno)
}
switch sa := sa.(type) {
case *syscall.SockaddrUnix:
addr = &UnixAddr{sa.Name, c.fd.proto == syscall.SOCK_DGRAM}
}
return
}
// Wrapper for Recvfrom
func (s *NetlinkSocket) Receive(bytesize int, block int) ([]syscall.NetlinkMessage, error) {
rb := make([]byte, bytesize)
nr, _, err := syscall.Recvfrom(s.fd, rb, 0|block)
//nr, _, err := syscall.Recvfrom(s, rb, syscall.MSG_PEEK|syscall.MSG_DONTWAIT)
if err != nil {
return nil, err
}
if nr < syscall.NLMSG_HDRLEN {
return nil, syscall.EINVAL
}
rb = rb[:nr]
return ParseAuditNetlinkMessage(rb)
}
// genl_ctrl_probe_by_name is not exposed in the original libnl
func GenlCtrlProbeByName(sk *NlSock, name string) (AttrMap, error) {
if err := GenlSendSimple(sk, GENL_ID_CTRL, CTRL_CMD_GETFAMILY, CTRL_VERSION, syscall.NLM_F_DUMP); err != nil {
return AttrMap{}, err
}
var ret AttrMap
err := func() error {
for {
buf := make([]byte, syscall.Getpagesize())
if nn, _, err := syscall.Recvfrom(sk.Fd, buf, syscall.MSG_TRUNC); err != nil {
return err
} else if nn > len(buf) {
return NLE_MSG_TRUNC
} else {
buf = buf[:nn]
}
if msgs, err := syscall.ParseNetlinkMessage(buf); err != nil {
return err
} else {
for _, msg := range msgs {
switch msg.Header.Type {
case GENL_ID_CTRL:
genl := (*GenlMsghdr)(unsafe.Pointer(&msg.Data[0]))
switch genl.Cmd {
case CTRL_CMD_NEWFAMILY:
if attrs, err := CtrlPolicy.Parse(msg.Data[GENL_HDRLEN:]); err != nil {
return err
} else if info, ok := attrs.(AttrMap); !ok {
// shold not happen
} else if value := info.Get(CTRL_ATTR_FAMILY_NAME); value == nil {
// should not happen by kernel
} else if string(value.(NulString)) == name {
ret = info
}
default:
return fmt.Errorf("unexpected command")
}
case syscall.NLMSG_DONE:
return nil
case syscall.NLMSG_ERROR:
return fmt.Errorf("NlMsgerr=%s", (*syscall.NlMsgerr)(unsafe.Pointer(&msg.Data[0])))
default:
return fmt.Errorf("unexpected NlMsghdr=%s", msg.Header)
}
}
}
}
}()
return ret, err
}
func (s *NetlinkSocket) Receive() ([]syscall.NetlinkMessage, error) {
if s.fd < 0 {
return nil, fmt.Errorf("Receive called on a closed socket")
}
rb := make([]byte, syscall.Getpagesize())
nr, _, err := syscall.Recvfrom(s.fd, rb, 0)
if err != nil {
return nil, err
}
if nr < syscall.NLMSG_HDRLEN {
return nil, fmt.Errorf("Got short response from netlink")
}
rb = rb[:nr]
return syscall.ParseNetlinkMessage(rb)
}
// ReadFromUDP reads a UDP packet from c, copying the payload into b.
// It returns the number of bytes copied into b and the return address
// that was on the packet.
//
// ReadFromUDP can be made to time out and return err == os.EAGAIN
// after a fixed time limit; see SetTimeout and SetReadTimeout.
func (c *UDPConn) ReadFromUDP(b []byte) (n int, addr *UDPAddr, err os.Error) {
if !c.ok() {
return 0, nil, os.EINVAL
}
n, sa, errno := syscall.Recvfrom(c.fd.fd, b, 0)
if errno != 0 {
err = os.Errno(errno)
}
switch sa := sa.(type) {
case *syscall.SockaddrInet4:
addr = &UDPAddr{&sa.Addr, sa.Port}
case *syscall.SockaddrInet6:
addr = &UDPAddr{&sa.Addr, sa.Port}
}
return
}
