Method getSockOptIP

pkg/sentry/socket/netstack/netstack.go:1638–1909

getSockOptIP implements linux getsockopt(2) when the level is SOL_IP.

(t *kernel.Task, ep commonEndpoint, name int, outPtr hostarch.Addr, outLen int, _ int)

// getSockOptIP implements linux getsockopt(2) when the level is SOL_IP.
func (s *sock) getSockOptIP(t *kernel.Task, ep commonEndpoint, name int, outPtr hostarch.Addr, outLen int, _ int) (marshal.Marshallable, *syserr.Error) {
	if _, ok := ep.(tcpip.Endpoint); !ok {
		log.Warningf("SOL_IP options not supported on endpoints other than tcpip.Endpoint: option = %d, endpoint = %T", name, ep)
		return nil, syserr.ErrUnknownProtocolOption
	}
	// Rejection of SOL_IP options for AF_INET6 RAW sockets matches Linux behavior:
	// https://github.com/torvalds/linux/blob/cec1e6e5d1a/net/ipv6/ipv6_sockglue.c#L1453
	if family, skType, _ := s.Type(); family == linux.AF_INET6 && skType == linux.SOCK_RAW {
		return nil, syserr.ErrUnknownProtocolOption
	}

	switch name {
	case linux.IP_TTL:
		if outLen < sizeOfInt32 {
			return nil, syserr.ErrInvalidArgument
		}

		v, err := ep.GetSockOptInt(tcpip.IPv4TTLOption)
		if err != nil {
			return nil, syserr.TranslateNetstackError(err)
		}

		// Fill in the default value, if needed.
		vP := primitive.Int32(v)
		if vP == 0 {
			vP, err = defaultTTL(t, header.IPv4ProtocolNumber)
			if err != nil {
				return nil, syserr.TranslateNetstackError(err)
			}
		}

		return &vP, nil

	case linux.IP_RECVTTL:
		if outLen < sizeOfInt32 {
			return nil, syserr.ErrInvalidArgument
		}

		v := primitive.Int32(boolToInt32(ep.SocketOptions().GetReceiveTTL()))
		return &v, nil

	case linux.IP_MULTICAST_TTL:
		if outLen < sizeOfInt32 {
			return nil, syserr.ErrInvalidArgument
		}

		v, err := ep.GetSockOptInt(tcpip.MulticastTTLOption)
		if err != nil {
			return nil, syserr.TranslateNetstackError(err)
		}

		vP := primitive.Int32(v)
		return &vP, nil

	case linux.IP_MULTICAST_IF:
		if outLen < len(linux.InetAddr{}) {
			return nil, syserr.ErrInvalidArgument
		}