// Saves stats from the socket to the TPacket instance
func (h *TPacket) SocketStats() (SocketStats, SocketStatsV3, error) {
h.mu.Lock()
defer h.mu.Unlock()
// We need to save the counters since asking for the stats will clear them
if h.tpVersion == TPacketVersion3 {
prevStats := h.socketStatsV3
socklen := unsafe.Sizeof(h.socketStatsV3)
var slt C.socklen_t = C.socklen_t(socklen)
_, err := C.getsockopt(h.fd, C.SOL_PACKET, C.PACKET_STATISTICS, unsafe.Pointer(&h.socketStatsV3), &slt)
if err != nil {
return SocketStats{}, SocketStatsV3{}, err
}
h.socketStatsV3.tp_packets += prevStats.tp_packets
h.socketStatsV3.tp_drops += prevStats.tp_drops
h.socketStatsV3.tp_freeze_q_cnt += prevStats.tp_freeze_q_cnt
return h.socketStats, h.socketStatsV3, nil
} else {
prevStats := h.socketStats
socklen := unsafe.Sizeof(h.socketStats)
var slt C.socklen_t = C.socklen_t(socklen)
_, err := C.getsockopt(h.fd, C.SOL_PACKET, C.PACKET_STATISTICS, unsafe.Pointer(&h.socketStats), &slt)
if err != nil {
return SocketStats{}, SocketStatsV3{}, err
}
h.socketStats.tp_packets += prevStats.tp_packets
h.socketStats.tp_drops += prevStats.tp_drops
return h.socketStats, h.socketStatsV3, nil
}
}
func cgoSockaddr(ip IP, zone string) (*C.struct_sockaddr, C.socklen_t) {
if ip4 := ip.To4(); ip4 != nil {
return cgoSockaddrInet4(ip4), C.socklen_t(syscall.SizeofSockaddrInet4)
}
if ip6 := ip.To16(); ip6 != nil {
return cgoSockaddrInet6(ip6, zoneToInt(zone)), C.socklen_t(syscall.SizeofSockaddrInet6)
}
return nil, 0
}
func (sock fd) accept() (nfd fd, addr ax25Addr, err error) {
addrLen := C.socklen_t(unsafe.Sizeof(addr))
n, err := C.accept(
C.int(sock),
(*C.struct_sockaddr)(unsafe.Pointer(&addr)),
&addrLen)
if addrLen != C.socklen_t(unsafe.Sizeof(addr)) {
panic("unexpected socklet_t")
}
return fd(n), addr, err
}
func newAfalg() (a *afalg, err error) {
a = &afalg{tfm_fd: -1, op_fd: -1}
runtime.SetFinalizer(a, func(a *afalg) {
a.Close()
})
a.tfm_fd, err = syscall.Socket(syscall.AF_ALG, syscall.SOCK_SEQPACKET, 0)
if err != nil || a.tfm_fd == -1 {
a.Close()
return nil, fmt.Errorf("failed creating af_alg socket: %v", err)
}
// rats, we can't call Bind with a sockaddr_alg. There's no sockaddr_alg
// in the go stdlib, nor can i make up my own byte array that matches
// the required sockaddr interface in the bind call. have to use cgo.
if C.bind(C.int(a.tfm_fd), (*C.struct_sockaddr)(unsafe.Pointer(&C.sha1_sa)),
C.socklen_t(unsafe.Sizeof(C.sha1_sa))) != 0 {
a.Close()
return nil, fmt.Errorf("failed binding af_alg connection")
}
// can't call Accept with go's stdlib, cause it's going to make up and
// pass a sockaddr to fill in. not only do we not care about the sockaddr,
// the sockaddr type is sockaddr_alg, and go doesn't understand that.
nfd, _, e := syscall.Syscall(syscall.SYS_ACCEPT, uintptr(a.tfm_fd), 0, 0)
a.op_fd = int(nfd)
if e != 0 || a.op_fd == -1 {
a.Close()
return nil, fmt.Errorf("failed accepting af_alg connection: %v", e)
}
return a, nil
}
func (b *ax25Beacon) Now() error {
// Create file descriptor
//REVIEW: Should we keep it for next beacon?
var socket fd
if f, err := syscall.Socket(syscall.AF_AX25, syscall.SOCK_DGRAM, 0); err != nil {
return err
} else {
socket = fd(f)
}
defer socket.close()
if err := socket.bind(b.localAddr); err != nil {
return fmt.Errorf("bind: %s", err)
}
msg := C.CString(b.message)
_, err := C.sendto(
C.int(socket),
unsafe.Pointer(msg),
C.size_t(len(b.message)),
0,
(*C.struct_sockaddr)(unsafe.Pointer(&b.remoteAddr)),
C.socklen_t(unsafe.Sizeof(b.remoteAddr)),
)
return err
}
func (sock fd) bind(addr ax25Addr) (err error) {
_, err = C.bind(
C.int(sock),
(*C.struct_sockaddr)(unsafe.Pointer(&addr)),
C.socklen_t(unsafe.Sizeof(addr)))
return
}
// setTPacketVersion asks the kernel to set TPacket to a particular version, and returns an error on failure.
func (h *TPacket) setTPacketVersion(version OptTPacketVersion) error {
val := C.int(version)
_, err := C.setsockopt(h.fd, C.SOL_PACKET, C.PACKET_VERSION, unsafe.Pointer(&val), C.socklen_t(unsafe.Sizeof(val)))
if err != nil {
return fmt.Errorf("setsockopt packet_version: %v", err)
}
return nil
}
// Processes a UDP packet. For when you're handling UDP yourself.
func (c *UTPContext) ProcessUDP(buf []byte, len int,
to *syscall.RawSockaddr, tolen int) int {
bufptr := (*C.byte)(unsafe.Pointer(&buf[0]))
adrptr := (*C.struct_sockaddr)(unsafe.Pointer(to))
return int(C.utp_process_udp(c.raw, bufptr, C.size_t(len),
adrptr, C.socklen_t(tolen)))
}
// SetFanout activates TPacket's fanout ability.
// Use of Fanout requires creating multiple TPacket objects and the same id/type to
// a SetFanout call on each. Note that this can be done cross-process, so if two
// different processes both call SetFanout with the same type/id, they'll share
// packets between them. The same should work for multiple TPacket objects within
// the same process.
func (h *TPacket) SetFanout(t FanoutType, id uint16) error {
h.mu.Lock()
defer h.mu.Unlock()
arg := C.int(t) << 16
arg |= C.int(id)
_, err := C.setsockopt(h.fd, C.SOL_PACKET, C.PACKET_FANOUT, unsafe.Pointer(&arg), C.socklen_t(unsafe.Sizeof(arg)))
return err
}
// Clear socket counters and return empty stats
func (h *TPacket) InitSocketStats() error {
if h.tpVersion == TPacketVersion3 {
socklen := unsafe.Sizeof(h.socketStatsV3)
var slt C.socklen_t = C.socklen_t(socklen)
_, err := C.getsockopt(h.fd, C.SOL_PACKET, C.PACKET_STATISTICS, unsafe.Pointer(&h.socketStatsV3), &slt)
if err != nil {
return err
}
h.socketStatsV3 = SocketStatsV3{}
} else {
socklen := unsafe.Sizeof(h.socketStats)
var slt C.socklen_t = C.socklen_t(socklen)
_, err := C.getsockopt(h.fd, C.SOL_PACKET, C.PACKET_STATISTICS, unsafe.Pointer(&h.socketStats), &slt)
if err != nil {
return err
}
h.socketStats = SocketStats{}
}
return nil
}
func NewInterfaces() ([]InterfaceTotal, string) {
var ifaces *C.struct_ifaddrs
if getrc, _ := C.getifaddrs(&ifaces); getrc != 0 {
return []InterfaceTotal{}, ""
}
defer C.freeifaddrs(ifaces)
ifs := []InterfaceTotal{}
IP := ""
for fi := ifaces; fi != nil; fi = fi.ifa_next {
if fi.ifa_addr == nil {
continue
}
ifa_name := C.GoString(fi.ifa_name)
if IP == "" &&
fi.ifa_addr.sa_family == C.AF_INET &&
ifa_name != "lo" &&
!rx_lo.Match([]byte(ifa_name)) &&
realInterfaceName(ifa_name) {
sa_in := (*C.struct_sockaddr_in)(unsafe.Pointer(fi.ifa_addr))
if C.inet_ntop(
C.int(fi.ifa_addr.sa_family), // C.AF_INET,
unsafe.Pointer(&sa_in.sin_addr),
&C.ADDR[0],
C.socklen_t(unsafe.Sizeof(C.ADDR))) != nil {
IP = C.GoString((*C.char)(unsafe.Pointer(&C.ADDR)))
}
}
if fi.ifa_addr.sa_family != C.AF_LINK {
continue
}
data := fi.ifa_data
if C.Ibytes(data) == 0 &&
C.Obytes(data) == 0 {
continue
}
ifs = append(ifs, InterfaceTotal{
Name: ifa_name,
In: uint(C.Ibytes(data)),
Out: uint(C.Obytes(data)),
})
}
return ifs, IP
}
// bindToInterface binds the TPacket socket to a particular named interface.
func (h *TPacket) bindToInterface(ifaceName string) error {
iface, err := net.InterfaceByName(ifaceName)
if err != nil {
return fmt.Errorf("InterfaceByName: %v", err)
}
var ll C.struct_sockaddr_ll
ll.sll_family = C.AF_PACKET
ll.sll_protocol = C.__be16(C.htons(C.ETH_P_ALL))
ll.sll_ifindex = C.int(iface.Index)
if _, err := C.bind(h.fd, (*C.struct_sockaddr)(unsafe.Pointer(&ll)), C.socklen_t(unsafe.Sizeof(ll))); err != nil {
return fmt.Errorf("bindToInterface: %v", err)
}
return nil
}
func ntop(fi *C.struct_ifaddrs) (string, bool) {
if fi.ifa_addr == nil {
return "", false
}
if fi.ifa_addr.sa_family != C.AF_INET {
return "", false
}
saIn := (*C.struct_sockaddr_in)(unsafe.Pointer(fi.ifa_addr))
if nil == C.inet_ntop(
C.int(fi.ifa_addr.sa_family), // C.AF_INET,
unsafe.Pointer(&saIn.sin_addr),
&C.ADDR[0],
C.socklen_t(unsafe.Sizeof(C.ADDR))) {
return "", false
}
return C.GoString((*C.char)(unsafe.Pointer(&C.ADDR))), true
}
func (s *UTPSocket) Connect(addr *UTPAddr) (int, error) {
// func (s *UTPSocket) Connect(to *syscall.RawSockaddr, tolen int) int {
if addr == nil {
return 0, net.InvalidAddrError("No address given.")
}
sa, err := addr.Sockaddr()
if err != nil {
return 0, err
}
rsa, err := sockaddr.NewRawSockaddr(&sa)
if err != nil {
return 0, err
}
ptr := (*C.struct_sockaddr)(unsafe.Pointer(&rsa.Raw))
ret := int(C.utp_connect(s.raw, ptr, C.socklen_t(rsa.Len)))
return ret, nil
}
// SetBPFFilter compiles and sets a BPF filter for the TPacket handle.
func (h *TPacket) SetBPFFilter(expr string) (err error) {
// Open a dummy pcap handle
p, err := pcap.OpenDead(layers.LinkTypeEthernet, int32(h.opts.frameSize))
if err != nil {
return fmt.Errorf("OpenDead: %s", err)
}
bpf, err := p.NewBPF(expr)
if err != nil {
return fmt.Errorf("NewBPF: %s", err)
}
program := bpf.BPF()
_, err = C.setsockopt(h.fd, C.SOL_SOCKET, C.SO_ATTACH_FILTER,
unsafe.Pointer(&program), C.socklen_t(unsafe.Sizeof(program)))
if err != nil {
return fmt.Errorf("setsockopt: %s", err)
}
return nil
}
func NewInterfaces(CH chan InterfacesInfo) {
var ifaces *C.struct_ifaddrs
if getrc, _ := C.getifaddrs(&ifaces); getrc != 0 {
CH <- InterfacesInfo{}
return
}
defer C.freeifaddrs(ifaces)
ifs := []InterfaceInfo{}
IP := ""
for fi := ifaces; fi != nil; fi = fi.ifa_next {
if fi.ifa_addr == nil {
continue
}
ifa_name := C.GoString(fi.ifa_name)
if IP == "" &&
fi.ifa_addr.sa_family == C.AF_INET &&
!rx_lo.Match([]byte(ifa_name)) &&
realInterfaceName(ifa_name) {
sa_in := (*C.struct_sockaddr_in)(unsafe.Pointer(fi.ifa_addr))
if C.inet_ntop(
C.int(fi.ifa_addr.sa_family), // C.AF_INET,
unsafe.Pointer(&sa_in.sin_addr),
&C.ADDR[0],
C.socklen_t(unsafe.Sizeof(C.ADDR))) != nil {
IP = C.GoString((*C.char)(unsafe.Pointer(&C.ADDR)))
}
}
if fi.ifa_addr.sa_family != C.AF_LINK {
continue
}
data := fi.ifa_data
it := InterfaceInfo{
Name: ifa_name,
InBytes: uint(C.Ibytes(data)),
OutBytes: uint(C.Obytes(data)),
InPackets: uint(C.Ipackets(data)),
OutPackets: uint(C.Opackets(data)),
InErrors: uint(C.Ierrors(data)),
OutErrors: uint(C.Oerrors(data)),
}
if it.InBytes == 0 &&
it.OutBytes == 0 &&
it.InPackets == 0 &&
it.OutPackets == 0 &&
it.InErrors == 0 &&
it.OutErrors == 0 {
continue
}
ifs = append(ifs, it)
}
CH <- InterfacesInfo{
List: ifs,
IP: IP,
}
}
// setUpRing sets up the shared-memory ring buffer between the user process and the kernel.
func (h *TPacket) setUpRing() (err error) {
totalSize := C.uint(h.opts.framesPerBlock * h.opts.numBlocks * h.opts.frameSize)
switch h.tpVersion {
case TPacketVersion1, TPacketVersion2:
var tp C.struct_tpacket_req
tp.tp_block_size = C.uint(h.opts.blockSize)
tp.tp_block_nr = C.uint(h.opts.numBlocks)
tp.tp_frame_size = C.uint(h.opts.frameSize)
tp.tp_frame_nr = C.uint(h.opts.framesPerBlock * h.opts.numBlocks)
if _, err := C.setsockopt(h.fd, C.SOL_PACKET, C.PACKET_RX_RING, unsafe.Pointer(&tp), C.socklen_t(unsafe.Sizeof(tp))); err != nil {
return fmt.Errorf("setsockopt packet_rx_ring: %v", err)
}
case TPacketVersion3:
var tp C.struct_tpacket_req3
tp.tp_block_size = C.uint(h.opts.blockSize)
tp.tp_block_nr = C.uint(h.opts.numBlocks)
tp.tp_frame_size = C.uint(h.opts.frameSize)
tp.tp_frame_nr = C.uint(h.opts.framesPerBlock * h.opts.numBlocks)
tp.tp_retire_blk_tov = C.uint(h.opts.blockTimeout / time.Millisecond)
if _, err := C.setsockopt(h.fd, C.SOL_PACKET, C.PACKET_RX_RING, unsafe.Pointer(&tp), C.socklen_t(unsafe.Sizeof(tp))); err != nil {
return fmt.Errorf("setsockopt packet_rx_ring v3: %v", err)
}
default:
return errors.New("invalid tpVersion")
}
if h.ring, err = C.mmap(nil, C.size_t(totalSize), C.PROT_READ|C.PROT_WRITE, C.MAP_SHARED, C.int(h.fd), 0); err != nil {
return
}
if h.ring == nil {
return errors.New("no ring")
}
return nil
}
func cgoNameinfoPTR(b []byte, sa *C.struct_sockaddr, salen C.socklen_t) (int, error) {
gerrno, err := C.getnameinfo(sa, salen, (*C.char)(unsafe.Pointer(&b[0])), C.socklen_t(len(b)), nil, 0, C.NI_NAMEREQD)
return int(gerrno), err
}
