diff options
Diffstat (limited to 'device/conn_linux.go')
-rw-r--r-- | device/conn_linux.go | 766 |
1 files changed, 0 insertions, 766 deletions
diff --git a/device/conn_linux.go b/device/conn_linux.go deleted file mode 100644 index e90b0e3..0000000 --- a/device/conn_linux.go +++ /dev/null @@ -1,766 +0,0 @@ -// +build !android - -/* SPDX-License-Identifier: MIT - * - * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved. - * - * This implements userspace semantics of "sticky sockets", modeled after - * WireGuard's kernelspace implementation. This is more or less a straight port - * of the sticky-sockets.c example code: - * https://git.zx2c4.com/wireguard-tools/tree/contrib/sticky-sockets/sticky-sockets.c - * - * Currently there is no way to achieve this within the net package: - * See e.g. https://github.com/golang/go/issues/17930 - * So this code is remains platform dependent. - */ - -package device - -import ( - "errors" - "net" - "strconv" - "sync" - "syscall" - "unsafe" - - "golang.org/x/sys/unix" - "golang.zx2c4.com/wireguard/rwcancel" -) - -const ( - FD_ERR = -1 -) - -type IPv4Source struct { - src [4]byte - ifindex int32 -} - -type IPv6Source struct { - src [16]byte - //ifindex belongs in dst.ZoneId -} - -type NativeEndpoint struct { - sync.Mutex - dst [unsafe.Sizeof(unix.SockaddrInet6{})]byte - src [unsafe.Sizeof(IPv6Source{})]byte - isV6 bool -} - -func (endpoint *NativeEndpoint) src4() *IPv4Source { - return (*IPv4Source)(unsafe.Pointer(&endpoint.src[0])) -} - -func (endpoint *NativeEndpoint) src6() *IPv6Source { - return (*IPv6Source)(unsafe.Pointer(&endpoint.src[0])) -} - -func (endpoint *NativeEndpoint) dst4() *unix.SockaddrInet4 { - return (*unix.SockaddrInet4)(unsafe.Pointer(&endpoint.dst[0])) -} - -func (endpoint *NativeEndpoint) dst6() *unix.SockaddrInet6 { - return (*unix.SockaddrInet6)(unsafe.Pointer(&endpoint.dst[0])) -} - -type nativeBind struct { - sock4 int - sock6 int - netlinkSock int - netlinkCancel *rwcancel.RWCancel - lastMark uint32 -} - -var _ Endpoint = (*NativeEndpoint)(nil) -var _ Bind = (*nativeBind)(nil) - -func CreateEndpoint(s string) (Endpoint, error) { - var end NativeEndpoint - addr, err := parseEndpoint(s) - if err != nil { - return nil, err - } - - ipv4 := addr.IP.To4() - if ipv4 != nil { - dst := end.dst4() - end.isV6 = false - dst.Port = addr.Port - copy(dst.Addr[:], ipv4) - end.ClearSrc() - return &end, nil - } - - ipv6 := addr.IP.To16() - if ipv6 != nil { - zone, err := zoneToUint32(addr.Zone) - if err != nil { - return nil, err - } - dst := end.dst6() - end.isV6 = true - dst.Port = addr.Port - dst.ZoneId = zone - copy(dst.Addr[:], ipv6[:]) - end.ClearSrc() - return &end, nil - } - - return nil, errors.New("Invalid IP address") -} - -func createNetlinkRouteSocket() (int, error) { - sock, err := unix.Socket(unix.AF_NETLINK, unix.SOCK_RAW, unix.NETLINK_ROUTE) - if err != nil { - return -1, err - } - saddr := &unix.SockaddrNetlink{ - Family: unix.AF_NETLINK, - Groups: unix.RTMGRP_IPV4_ROUTE, - } - err = unix.Bind(sock, saddr) - if err != nil { - unix.Close(sock) - return -1, err - } - return sock, nil - -} - -func CreateBind(port uint16, device *Device) (*nativeBind, uint16, error) { - var err error - var bind nativeBind - var newPort uint16 - - bind.netlinkSock, err = createNetlinkRouteSocket() - if err != nil { - return nil, 0, err - } - bind.netlinkCancel, err = rwcancel.NewRWCancel(bind.netlinkSock) - if err != nil { - unix.Close(bind.netlinkSock) - return nil, 0, err - } - - go bind.routineRouteListener(device) - - // attempt ipv6 bind, update port if successful - - bind.sock6, newPort, err = create6(port) - if err != nil { - if err != syscall.EAFNOSUPPORT { - bind.netlinkCancel.Cancel() - return nil, 0, err - } - } else { - port = newPort - } - - // attempt ipv4 bind, update port if successful - - bind.sock4, newPort, err = create4(port) - if err != nil { - if err != syscall.EAFNOSUPPORT { - bind.netlinkCancel.Cancel() - unix.Close(bind.sock6) - return nil, 0, err - } - } else { - port = newPort - } - - if bind.sock4 == FD_ERR && bind.sock6 == FD_ERR { - return nil, 0, errors.New("ipv4 and ipv6 not supported") - } - - return &bind, port, nil -} - -func (bind *nativeBind) SetMark(value uint32) error { - if bind.sock6 != -1 { - err := unix.SetsockoptInt( - bind.sock6, - unix.SOL_SOCKET, - unix.SO_MARK, - int(value), - ) - - if err != nil { - return err - } - } - - if bind.sock4 != -1 { - err := unix.SetsockoptInt( - bind.sock4, - unix.SOL_SOCKET, - unix.SO_MARK, - int(value), - ) - - if err != nil { - return err - } - } - - bind.lastMark = value - return nil -} - -func closeUnblock(fd int) error { - // shutdown to unblock readers and writers - unix.Shutdown(fd, unix.SHUT_RDWR) - return unix.Close(fd) -} - -func (bind *nativeBind) Close() error { - var err1, err2, err3 error - if bind.sock6 != -1 { - err1 = closeUnblock(bind.sock6) - } - if bind.sock4 != -1 { - err2 = closeUnblock(bind.sock4) - } - err3 = bind.netlinkCancel.Cancel() - - if err1 != nil { - return err1 - } - if err2 != nil { - return err2 - } - return err3 -} - -func (bind *nativeBind) ReceiveIPv6(buff []byte) (int, Endpoint, error) { - var end NativeEndpoint - if bind.sock6 == -1 { - return 0, nil, syscall.EAFNOSUPPORT - } - n, err := receive6( - bind.sock6, - buff, - &end, - ) - return n, &end, err -} - -func (bind *nativeBind) ReceiveIPv4(buff []byte) (int, Endpoint, error) { - var end NativeEndpoint - if bind.sock4 == -1 { - return 0, nil, syscall.EAFNOSUPPORT - } - n, err := receive4( - bind.sock4, - buff, - &end, - ) - return n, &end, err -} - -func (bind *nativeBind) Send(buff []byte, end Endpoint) error { - nend := end.(*NativeEndpoint) - if !nend.isV6 { - if bind.sock4 == -1 { - return syscall.EAFNOSUPPORT - } - return send4(bind.sock4, nend, buff) - } else { - if bind.sock6 == -1 { - return syscall.EAFNOSUPPORT - } - return send6(bind.sock6, nend, buff) - } -} - -func (end *NativeEndpoint) SrcIP() net.IP { - if !end.isV6 { - return net.IPv4( - end.src4().src[0], - end.src4().src[1], - end.src4().src[2], - end.src4().src[3], - ) - } else { - return end.src6().src[:] - } -} - -func (end *NativeEndpoint) DstIP() net.IP { - if !end.isV6 { - return net.IPv4( - end.dst4().Addr[0], - end.dst4().Addr[1], - end.dst4().Addr[2], - end.dst4().Addr[3], - ) - } else { - return end.dst6().Addr[:] - } -} - -func (end *NativeEndpoint) DstToBytes() []byte { - if !end.isV6 { - return (*[unsafe.Offsetof(end.dst4().Addr) + unsafe.Sizeof(end.dst4().Addr)]byte)(unsafe.Pointer(end.dst4()))[:] - } else { - return (*[unsafe.Offsetof(end.dst6().Addr) + unsafe.Sizeof(end.dst6().Addr)]byte)(unsafe.Pointer(end.dst6()))[:] - } -} - -func (end *NativeEndpoint) SrcToString() string { - return end.SrcIP().String() -} - -func (end *NativeEndpoint) DstToString() string { - var udpAddr net.UDPAddr - udpAddr.IP = end.DstIP() - if !end.isV6 { - udpAddr.Port = end.dst4().Port - } else { - udpAddr.Port = end.dst6().Port - } - return udpAddr.String() -} - -func (end *NativeEndpoint) ClearDst() { - for i := range end.dst { - end.dst[i] = 0 - } -} - -func (end *NativeEndpoint) ClearSrc() { - for i := range end.src { - end.src[i] = 0 - } -} - -func zoneToUint32(zone string) (uint32, error) { - if zone == "" { - return 0, nil - } - if intr, err := net.InterfaceByName(zone); err == nil { - return uint32(intr.Index), nil - } - n, err := strconv.ParseUint(zone, 10, 32) - return uint32(n), err -} - -func create4(port uint16) (int, uint16, error) { - - // create socket - - fd, err := unix.Socket( - unix.AF_INET, - unix.SOCK_DGRAM, - 0, - ) - - if err != nil { - return FD_ERR, 0, err - } - - addr := unix.SockaddrInet4{ - Port: int(port), - } - - // set sockopts and bind - - if err := func() error { - if err := unix.SetsockoptInt( - fd, - unix.SOL_SOCKET, - unix.SO_REUSEADDR, - 1, - ); err != nil { - return err - } - - if err := unix.SetsockoptInt( - fd, - unix.IPPROTO_IP, - unix.IP_PKTINFO, - 1, - ); err != nil { - return err - } - - return unix.Bind(fd, &addr) - }(); err != nil { - unix.Close(fd) - return FD_ERR, 0, err - } - - sa, err := unix.Getsockname(fd) - if err == nil { - addr.Port = sa.(*unix.SockaddrInet4).Port - } - - return fd, uint16(addr.Port), err -} - -func create6(port uint16) (int, uint16, error) { - - // create socket - - fd, err := unix.Socket( - unix.AF_INET6, - unix.SOCK_DGRAM, - 0, - ) - - if err != nil { - return FD_ERR, 0, err - } - - // set sockopts and bind - - addr := unix.SockaddrInet6{ - Port: int(port), - } - - if err := func() error { - - if err := unix.SetsockoptInt( - fd, - unix.SOL_SOCKET, - unix.SO_REUSEADDR, - 1, - ); err != nil { - return err - } - - if err := unix.SetsockoptInt( - fd, - unix.IPPROTO_IPV6, - unix.IPV6_RECVPKTINFO, - 1, - ); err != nil { - return err - } - - if err := unix.SetsockoptInt( - fd, - unix.IPPROTO_IPV6, - unix.IPV6_V6ONLY, - 1, - ); err != nil { - return err - } - - return unix.Bind(fd, &addr) - - }(); err != nil { - unix.Close(fd) - return FD_ERR, 0, err - } - - sa, err := unix.Getsockname(fd) - if err == nil { - addr.Port = sa.(*unix.SockaddrInet6).Port - } - - return fd, uint16(addr.Port), err -} - -func send4(sock int, end *NativeEndpoint, buff []byte) error { - - // construct message header - - cmsg := struct { - cmsghdr unix.Cmsghdr - pktinfo unix.Inet4Pktinfo - }{ - unix.Cmsghdr{ - Level: unix.IPPROTO_IP, - Type: unix.IP_PKTINFO, - Len: unix.SizeofInet4Pktinfo + unix.SizeofCmsghdr, - }, - unix.Inet4Pktinfo{ - Spec_dst: end.src4().src, - Ifindex: end.src4().ifindex, - }, - } - - end.Lock() - _, err := unix.SendmsgN(sock, buff, (*[unsafe.Sizeof(cmsg)]byte)(unsafe.Pointer(&cmsg))[:], end.dst4(), 0) - end.Unlock() - - if err == nil { - return nil - } - - // clear src and retry - - if err == unix.EINVAL { - end.ClearSrc() - cmsg.pktinfo = unix.Inet4Pktinfo{} - end.Lock() - _, err = unix.SendmsgN(sock, buff, (*[unsafe.Sizeof(cmsg)]byte)(unsafe.Pointer(&cmsg))[:], end.dst4(), 0) - end.Unlock() - } - - return err -} - -func send6(sock int, end *NativeEndpoint, buff []byte) error { - - // construct message header - - cmsg := struct { - cmsghdr unix.Cmsghdr - pktinfo unix.Inet6Pktinfo - }{ - unix.Cmsghdr{ - Level: unix.IPPROTO_IPV6, - Type: unix.IPV6_PKTINFO, - Len: unix.SizeofInet6Pktinfo + unix.SizeofCmsghdr, - }, - unix.Inet6Pktinfo{ - Addr: end.src6().src, - Ifindex: end.dst6().ZoneId, - }, - } - - if cmsg.pktinfo.Addr == [16]byte{} { - cmsg.pktinfo.Ifindex = 0 - } - - end.Lock() - _, err := unix.SendmsgN(sock, buff, (*[unsafe.Sizeof(cmsg)]byte)(unsafe.Pointer(&cmsg))[:], end.dst6(), 0) - end.Unlock() - - if err == nil { - return nil - } - - // clear src and retry - - if err == unix.EINVAL { - end.ClearSrc() - cmsg.pktinfo = unix.Inet6Pktinfo{} - end.Lock() - _, err = unix.SendmsgN(sock, buff, (*[unsafe.Sizeof(cmsg)]byte)(unsafe.Pointer(&cmsg))[:], end.dst6(), 0) - end.Unlock() - } - - return err -} - -func receive4(sock int, buff []byte, end *NativeEndpoint) (int, error) { - - // construct message header - - var cmsg struct { - cmsghdr unix.Cmsghdr - pktinfo unix.Inet4Pktinfo - } - - size, _, _, newDst, err := unix.Recvmsg(sock, buff, (*[unsafe.Sizeof(cmsg)]byte)(unsafe.Pointer(&cmsg))[:], 0) - - if err != nil { - return 0, err - } - end.isV6 = false - - if newDst4, ok := newDst.(*unix.SockaddrInet4); ok { - *end.dst4() = *newDst4 - } - - // update source cache - - if cmsg.cmsghdr.Level == unix.IPPROTO_IP && - cmsg.cmsghdr.Type == unix.IP_PKTINFO && - cmsg.cmsghdr.Len >= unix.SizeofInet4Pktinfo { - end.src4().src = cmsg.pktinfo.Spec_dst - end.src4().ifindex = cmsg.pktinfo.Ifindex - } - - return size, nil -} - -func receive6(sock int, buff []byte, end *NativeEndpoint) (int, error) { - - // construct message header - - var cmsg struct { - cmsghdr unix.Cmsghdr - pktinfo unix.Inet6Pktinfo - } - - size, _, _, newDst, err := unix.Recvmsg(sock, buff, (*[unsafe.Sizeof(cmsg)]byte)(unsafe.Pointer(&cmsg))[:], 0) - - if err != nil { - return 0, err - } - end.isV6 = true - - if newDst6, ok := newDst.(*unix.SockaddrInet6); ok { - *end.dst6() = *newDst6 - } - - // update source cache - - if cmsg.cmsghdr.Level == unix.IPPROTO_IPV6 && - cmsg.cmsghdr.Type == unix.IPV6_PKTINFO && - cmsg.cmsghdr.Len >= unix.SizeofInet6Pktinfo { - end.src6().src = cmsg.pktinfo.Addr - end.dst6().ZoneId = cmsg.pktinfo.Ifindex - } - - return size, nil -} - -func (bind *nativeBind) routineRouteListener(device *Device) { - type peerEndpointPtr struct { - peer *Peer - endpoint *Endpoint - } - var reqPeer map[uint32]peerEndpointPtr - var reqPeerLock sync.Mutex - - defer unix.Close(bind.netlinkSock) - - for msg := make([]byte, 1<<16); ; { - var err error - var msgn int - for { - msgn, _, _, _, err = unix.Recvmsg(bind.netlinkSock, msg[:], nil, 0) - if err == nil || !rwcancel.RetryAfterError(err) { - break - } - if !bind.netlinkCancel.ReadyRead() { - return - } - } - if err != nil { - return - } - - for remain := msg[:msgn]; len(remain) >= unix.SizeofNlMsghdr; { - - hdr := *(*unix.NlMsghdr)(unsafe.Pointer(&remain[0])) - - if uint(hdr.Len) > uint(len(remain)) { - break - } - - switch hdr.Type { - case unix.RTM_NEWROUTE, unix.RTM_DELROUTE: - if hdr.Seq <= MaxPeers && hdr.Seq > 0 { - if uint(len(remain)) < uint(hdr.Len) { - break - } - if hdr.Len > unix.SizeofNlMsghdr+unix.SizeofRtMsg { - attr := remain[unix.SizeofNlMsghdr+unix.SizeofRtMsg:] - for { - if uint(len(attr)) < uint(unix.SizeofRtAttr) { - break - } - attrhdr := *(*unix.RtAttr)(unsafe.Pointer(&attr[0])) - if attrhdr.Len < unix.SizeofRtAttr || uint(len(attr)) < uint(attrhdr.Len) { - break - } - if attrhdr.Type == unix.RTA_OIF && attrhdr.Len == unix.SizeofRtAttr+4 { - ifidx := *(*uint32)(unsafe.Pointer(&attr[unix.SizeofRtAttr])) - reqPeerLock.Lock() - if reqPeer == nil { - reqPeerLock.Unlock() - break - } - pePtr, ok := reqPeer[hdr.Seq] - reqPeerLock.Unlock() - if !ok { - break - } - pePtr.peer.Lock() - if &pePtr.peer.endpoint != pePtr.endpoint { - pePtr.peer.Unlock() - break - } - if uint32(pePtr.peer.endpoint.(*NativeEndpoint).src4().ifindex) == ifidx { - pePtr.peer.Unlock() - break - } - pePtr.peer.endpoint.(*NativeEndpoint).ClearSrc() - pePtr.peer.Unlock() - } - attr = attr[attrhdr.Len:] - } - } - break - } - reqPeerLock.Lock() - reqPeer = make(map[uint32]peerEndpointPtr) - reqPeerLock.Unlock() - go func() { - device.peers.RLock() - i := uint32(1) - for _, peer := range device.peers.keyMap { - peer.RLock() - if peer.endpoint == nil || peer.endpoint.(*NativeEndpoint) == nil { - peer.RUnlock() - continue - } - if peer.endpoint.(*NativeEndpoint).isV6 || peer.endpoint.(*NativeEndpoint).src4().ifindex == 0 { - peer.RUnlock() - break - } - nlmsg := struct { - hdr unix.NlMsghdr - msg unix.RtMsg - dsthdr unix.RtAttr - dst [4]byte - srchdr unix.RtAttr - src [4]byte - markhdr unix.RtAttr - mark uint32 - }{ - unix.NlMsghdr{ - Type: uint16(unix.RTM_GETROUTE), - Flags: unix.NLM_F_REQUEST, - Seq: i, - }, - unix.RtMsg{ - Family: unix.AF_INET, - Dst_len: 32, - Src_len: 32, - }, - unix.RtAttr{ - Len: 8, - Type: unix.RTA_DST, - }, - peer.endpoint.(*NativeEndpoint).dst4().Addr, - unix.RtAttr{ - Len: 8, - Type: unix.RTA_SRC, - }, - peer.endpoint.(*NativeEndpoint).src4().src, - unix.RtAttr{ - Len: 8, - Type: unix.RTA_MARK, - }, - uint32(bind.lastMark), - } - nlmsg.hdr.Len = uint32(unsafe.Sizeof(nlmsg)) - reqPeerLock.Lock() - reqPeer[i] = peerEndpointPtr{ - peer: peer, - endpoint: &peer.endpoint, - } - reqPeerLock.Unlock() - peer.RUnlock() - i++ - _, err := bind.netlinkCancel.Write((*[unsafe.Sizeof(nlmsg)]byte)(unsafe.Pointer(&nlmsg))[:]) - if err != nil { - break - } - } - device.peers.RUnlock() - }() - } - remain = remain[hdr.Len:] - } - } -} |