github.com/tumi8/quic-go@v0.37.4-tum/sys_conn_helper_darwin.go (about)

     1  //go:build darwin
     2  
     3  package quic
     4  
     5  import (
     6  	"encoding/binary"
     7  	"net/netip"
     8  
     9  	"golang.org/x/sys/unix"
    10  )
    11  
    12  const (
    13  	msgTypeIPTOS = unix.IP_RECVTOS
    14  	ipv4PKTINFO  = unix.IP_RECVPKTINFO
    15  )
    16  
    17  // ReadBatch only returns a single packet on OSX,
    18  // see https://godoc.org/golang.org/x/net/ipv4#PacketConn.ReadBatch.
    19  const batchSize = 1
    20  
    21  func parseIPv4PktInfo(body []byte) (ip netip.Addr, ifIndex uint32, ok bool) {
    22  	// struct in_pktinfo {
    23  	// 	unsigned int   ipi_ifindex;  /* Interface index */
    24  	// 	struct in_addr ipi_spec_dst; /* Local address */
    25  	// 	struct in_addr ipi_addr;     /* Header Destination address */
    26  	// };
    27  	if len(body) != 12 {
    28  		return netip.Addr{}, 0, false
    29  	}
    30  	return netip.AddrFrom4(*(*[4]byte)(body[8:12])), binary.LittleEndian.Uint32(body), true
    31  }