diff options
| -rw-r--r-- | pkg/sentry/socket/rpcinet/socket.go | 73 |
1 files changed, 68 insertions, 5 deletions
diff --git a/pkg/sentry/socket/rpcinet/socket.go b/pkg/sentry/socket/rpcinet/socket.go index 207123d6f..72fa1ca8f 100644 --- a/pkg/sentry/socket/rpcinet/socket.go +++ b/pkg/sentry/socket/rpcinet/socket.go @@ -64,10 +64,6 @@ type socketOperations struct { // Verify that we actually implement socket.Socket. var _ = socket.Socket(&socketOperations{}) -const ( - sizeOfIfReq = 40 -) - // New creates a new RPC socket. func newSocketFile(ctx context.Context, stack *Stack, family int, skType int, protocol int) (*fs.File, *syserr.Error) { id, c := stack.rpcConn.NewRequest(pb.SyscallRequest{Args: &pb.SyscallRequest_Socket{&pb.SocketRequest{Family: int64(family), Type: int64(skType | syscall.SOCK_NONBLOCK), Protocol: int64(protocol)}}}, false /* ignoreResult */) @@ -465,6 +461,55 @@ func rpcIoctl(t *kernel.Task, fd, cmd uint32, arg []byte) ([]byte, error) { return res.(*pb.IOCtlResponse_Value).Value, nil } +// ifconfIoctlFromStack populates a struct ifconf for the SIOCGIFCONF ioctl. +func ifconfIoctlFromStack(ctx context.Context, io usermem.IO, ifc *linux.IFConf) error { + // If Ptr is NULL, return the necessary buffer size via Len. + // Otherwise, write up to Len bytes starting at Ptr containing ifreq + // structs. + t := ctx.(*kernel.Task) + s := t.NetworkContext().(*Stack) + if s == nil { + return syserr.ErrNoDevice.ToError() + } + + if ifc.Ptr == 0 { + ifc.Len = int32(len(s.Interfaces())) * int32(linux.SizeOfIFReq) + return nil + } + + max := ifc.Len + ifc.Len = 0 + for key, ifaceAddrs := range s.InterfaceAddrs() { + iface := s.Interfaces()[key] + for _, ifaceAddr := range ifaceAddrs { + // Don't write past the end of the buffer. + if ifc.Len+int32(linux.SizeOfIFReq) > max { + break + } + if ifaceAddr.Family != linux.AF_INET { + continue + } + + // Populate ifr.ifr_addr. + ifr := linux.IFReq{} + ifr.SetName(iface.Name) + usermem.ByteOrder.PutUint16(ifr.Data[0:2], uint16(ifaceAddr.Family)) + usermem.ByteOrder.PutUint16(ifr.Data[2:4], 0) + copy(ifr.Data[4:8], ifaceAddr.Addr[:4]) + + // Copy the ifr to userspace. + dst := uintptr(ifc.Ptr) + uintptr(ifc.Len) + ifc.Len += int32(linux.SizeOfIFReq) + if _, err := usermem.CopyObjectOut(ctx, io, usermem.Addr(dst), ifr, usermem.IOOpts{ + AddressSpaceActive: true, + }); err != nil { + return err + } + } + } + return nil +} + // Ioctl implements fs.FileOperations.Ioctl. func (s *socketOperations) Ioctl(ctx context.Context, io usermem.IO, args arch.SyscallArguments) (uintptr, error) { t := ctx.(*kernel.Task) @@ -491,7 +536,25 @@ func (s *socketOperations) Ioctl(ctx context.Context, io usermem.IO, args arch.S syscall.SIOCGIFNAME, syscall.SIOCGIFNETMASK, syscall.SIOCGIFTXQLEN: - buf = make([]byte, sizeOfIfReq) + buf = make([]byte, linux.SizeOfIFReq) + case syscall.SIOCGIFCONF: + // SIOCGIFCONF has slightly different behavior than the others, in that it + // will need to populate the array of ifreqs. + var ifc linux.IFConf + if _, err := usermem.CopyObjectIn(ctx, io, args[2].Pointer(), &ifc, usermem.IOOpts{ + AddressSpaceActive: true, + }); err != nil { + return 0, err + } + + if err := ifconfIoctlFromStack(ctx, io, &ifc); err != nil { + return 0, err + } + _, err := usermem.CopyObjectOut(ctx, io, args[2].Pointer(), ifc, usermem.IOOpts{ + AddressSpaceActive: true, + }) + + return 0, err default: return 0, syserror.ENOTTY } |