diff options
Diffstat (limited to 'vendor/github.com/vishvananda/netlink/socket_linux.go')
-rw-r--r-- | vendor/github.com/vishvananda/netlink/socket_linux.go | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/vendor/github.com/vishvananda/netlink/socket_linux.go b/vendor/github.com/vishvananda/netlink/socket_linux.go new file mode 100644 index 000000000..b42b84f0c --- /dev/null +++ b/vendor/github.com/vishvananda/netlink/socket_linux.go @@ -0,0 +1,159 @@ +package netlink + +import ( + "errors" + "fmt" + "net" + "syscall" + + "github.com/vishvananda/netlink/nl" +) + +const ( + sizeofSocketID = 0x30 + sizeofSocketRequest = sizeofSocketID + 0x8 + sizeofSocket = sizeofSocketID + 0x18 +) + +type socketRequest struct { + Family uint8 + Protocol uint8 + Ext uint8 + pad uint8 + States uint32 + ID SocketID +} + +type writeBuffer struct { + Bytes []byte + pos int +} + +func (b *writeBuffer) Write(c byte) { + b.Bytes[b.pos] = c + b.pos++ +} + +func (b *writeBuffer) Next(n int) []byte { + s := b.Bytes[b.pos : b.pos+n] + b.pos += n + return s +} + +func (r *socketRequest) Serialize() []byte { + b := writeBuffer{Bytes: make([]byte, sizeofSocketRequest)} + b.Write(r.Family) + b.Write(r.Protocol) + b.Write(r.Ext) + b.Write(r.pad) + native.PutUint32(b.Next(4), r.States) + networkOrder.PutUint16(b.Next(2), r.ID.SourcePort) + networkOrder.PutUint16(b.Next(2), r.ID.DestinationPort) + copy(b.Next(4), r.ID.Source.To4()) + b.Next(12) + copy(b.Next(4), r.ID.Destination.To4()) + b.Next(12) + native.PutUint32(b.Next(4), r.ID.Interface) + native.PutUint32(b.Next(4), r.ID.Cookie[0]) + native.PutUint32(b.Next(4), r.ID.Cookie[1]) + return b.Bytes +} + +func (r *socketRequest) Len() int { return sizeofSocketRequest } + +type readBuffer struct { + Bytes []byte + pos int +} + +func (b *readBuffer) Read() byte { + c := b.Bytes[b.pos] + b.pos++ + return c +} + +func (b *readBuffer) Next(n int) []byte { + s := b.Bytes[b.pos : b.pos+n] + b.pos += n + return s +} + +func (s *Socket) deserialize(b []byte) error { + if len(b) < sizeofSocket { + return fmt.Errorf("socket data short read (%d); want %d", len(b), sizeofSocket) + } + rb := readBuffer{Bytes: b} + s.Family = rb.Read() + s.State = rb.Read() + s.Timer = rb.Read() + s.Retrans = rb.Read() + s.ID.SourcePort = networkOrder.Uint16(rb.Next(2)) + s.ID.DestinationPort = networkOrder.Uint16(rb.Next(2)) + s.ID.Source = net.IPv4(rb.Read(), rb.Read(), rb.Read(), rb.Read()) + rb.Next(12) + s.ID.Destination = net.IPv4(rb.Read(), rb.Read(), rb.Read(), rb.Read()) + rb.Next(12) + s.ID.Interface = native.Uint32(rb.Next(4)) + s.ID.Cookie[0] = native.Uint32(rb.Next(4)) + s.ID.Cookie[1] = native.Uint32(rb.Next(4)) + s.Expires = native.Uint32(rb.Next(4)) + s.RQueue = native.Uint32(rb.Next(4)) + s.WQueue = native.Uint32(rb.Next(4)) + s.UID = native.Uint32(rb.Next(4)) + s.INode = native.Uint32(rb.Next(4)) + return nil +} + +// SocketGet returns the Socket identified by its local and remote addresses. +func SocketGet(local, remote net.Addr) (*Socket, error) { + localTCP, ok := local.(*net.TCPAddr) + if !ok { + return nil, ErrNotImplemented + } + remoteTCP, ok := remote.(*net.TCPAddr) + if !ok { + return nil, ErrNotImplemented + } + localIP := localTCP.IP.To4() + if localIP == nil { + return nil, ErrNotImplemented + } + remoteIP := remoteTCP.IP.To4() + if remoteIP == nil { + return nil, ErrNotImplemented + } + + s, err := nl.Subscribe(syscall.NETLINK_INET_DIAG) + if err != nil { + return nil, err + } + defer s.Close() + req := nl.NewNetlinkRequest(nl.SOCK_DIAG_BY_FAMILY, 0) + req.AddData(&socketRequest{ + Family: syscall.AF_INET, + Protocol: syscall.IPPROTO_TCP, + ID: SocketID{ + SourcePort: uint16(localTCP.Port), + DestinationPort: uint16(remoteTCP.Port), + Source: localIP, + Destination: remoteIP, + Cookie: [2]uint32{nl.TCPDIAG_NOCOOKIE, nl.TCPDIAG_NOCOOKIE}, + }, + }) + s.Send(req) + msgs, err := s.Receive() + if err != nil { + return nil, err + } + if len(msgs) == 0 { + return nil, errors.New("no message nor error from netlink") + } + if len(msgs) > 2 { + return nil, fmt.Errorf("multiple (%d) matching sockets", len(msgs)) + } + sock := &Socket{} + if err := sock.deserialize(msgs[0].Data); err != nil { + return nil, err + } + return sock, nil +} |