You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: sys_zos_s390x.go
    path of file: ./repos/moby/vendor/golang.org/x/net/internal/socket
    
    the code of the file until where you have to start completion: // Copyright 2020 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package socket

import (
	"net"
	"syscall"
	"unsafe"
)

func syscall_syscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err syscall.Errno)
func syscall_syscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err syscall.Errno)

func probeProtocolStack() int {
	return 4 // sizeof(int) on GOOS=zos GOARCH=s390x
}

func getsockopt(s uintptr, level, name int, b 
    
func recvmsg(s uintptr, buffers [][]byte, oob []byte, flags int, network string) (n, oobn int, recvflags int, from net.Addr, err error) {
	var h msghdr
	vs := make([]iovec, len(buffers))
	var sa []byte
	if network != "tcp" {
		sa = make([]byte, sizeofSockaddrInet6)
	}
	h.pack(vs, buffers, oob, sa)
	sn, _, errno := syscall_syscall(syscall.SYS___RECVMSG_A, s, uintptr(unsafe.Pointer(&h)), uintptr(flags))
	n = int(sn)
	oobn = h.controllen()
	recvflags = h.flags()
	err = errnoErr(errno)
	if network != "tcp" {
		var err2 error
		from, err2 = parseInetAddr(sa, network)
		if err2 != nil && err == nil {
			err = err2
		}
	}
	return
}