net pkg

README.md

@@ -2,4 +2,7 @@
 
 This package extracts unexported code from `syscall`. The standard library should just export these. See https://groups.google.com/d/msg/golang-nuts/B-meiFfkmH0/-TxP1r6zvk8J
 
-Godoc: http://godoc.org/github.com/jbenet/go-sockaddr
+Godoc:
+
+- sockaddr - http://godoc.org/github.com/jbenet/go-sockaddr
+- sockaddr/net - http://godoc.org/github.com/jbenet/go-sockaddr/net

net/net.go

+// package sanet provides conversions between net.Addr and syscall.Sockaddr
+package sanet
+
+import (
+	"net"
+	"syscall"
+)
+
+// NetAddrToSockaddr converts a net.Addr to a syscall.Sockaddr.
+// Returns nil if the input is invalid or conversion is not possible.
+func NetAddrToSockaddr(addr net.Addr) syscall.Sockaddr {
+	switch addr := addr.(type) {
+	default:
+		return nil
+	case *net.IPAddr:
+		return IPAddrToSockaddr(addr)
+	case *net.TCPAddr:
+		return TCPAddrToSockaddr(addr)
+	case *net.UDPAddr:
+		return UDPAddrToSockaddr(addr)
+	case *net.UnixAddr:
+		sa, _ := UnixAddrToSockaddr(addr)
+		return sa
+	}
+}
+
+// IPAndZoneToSockaddr converts a net.IP (with optional IPv6 Zone) to a syscall.Sockaddr
+// Returns nil if conversion fails.
+func IPAndZoneToSockaddr(ip net.IP, zone string) syscall.Sockaddr {
+	switch {
+	default:
+		return nil
+
+	case ip.To4() != nil:
+		var buf [4]byte
+		copy(buf[:], ip[12:16]) // last 4 bytes
+		return &syscall.SockaddrInet4{Addr: buf}
+
+	case ip.To16() != nil:
+		var buf [16]byte
+		copy(buf[:], ip)
+		return &syscall.SockaddrInet6{Addr: buf, ZoneId: uint32(IP6ZoneToInt(zone))}
+	}
+}
+
+// IPAddrToSockaddr converts a net.IPAddr to a syscall.Sockaddr.
+// Returns nil if conversion fails.
+func IPAddrToSockaddr(addr *net.IPAddr) syscall.Sockaddr {
+	return IPAndZoneToSockaddr(addr.IP, addr.Zone)
+}
+
+// TCPAddrToSockaddr converts a net.TCPAddr to a syscall.Sockaddr.
+// Returns nil if conversion fails.
+func TCPAddrToSockaddr(addr *net.TCPAddr) syscall.Sockaddr {
+	sa := IPAndZoneToSockaddr(addr.IP, addr.Zone)
+	if sa == nil {
+		return sa
+	}
+
+	switch sa := sa.(type) {
+	default:
+		return nil
+	case *syscall.SockaddrInet4:
+		sa.Port = addr.Port
+		return sa
+	case *syscall.SockaddrInet6:
+		sa.Port = addr.Port
+		return sa
+	}
+}
+
+// UDPAddrToSockaddr converts a net.UDPAddr to a syscall.Sockaddr.
+// Returns nil if conversion fails.
+func UDPAddrToSockaddr(addr *net.UDPAddr) syscall.Sockaddr {
+	sa := IPAndZoneToSockaddr(addr.IP, addr.Zone)
+	if sa == nil {
+		return sa
+	}
+
+	switch sa := sa.(type) {
+	default:
+		return nil
+	case *syscall.SockaddrInet4:
+		sa.Port = addr.Port
+		return sa
+	case *syscall.SockaddrInet6:
+		sa.Port = addr.Port
+		return sa
+	}
+}
+
+// UnixAddrToSockaddr converts a net.UnixAddr to a syscall.Sockaddr, and returns
+// the type (syscall.SOCK_STREAM, syscall.SOCK_DGRAM, syscall.SOCK_SEQPACKET)
+// Returns (nil, 0) if conversion fails.
+func UnixAddrToSockaddr(addr *net.UnixAddr) (syscall.Sockaddr, int) {
+	t := 0
+	switch addr.Net {
+	default:
+		return nil, 0
+	case "unix":
+		t = syscall.SOCK_STREAM
+	case "unixgram":
+		t = syscall.SOCK_DGRAM
+	case "unixpacket":
+		t = syscall.SOCK_SEQPACKET
+	}
+	return &syscall.SockaddrUnix{Name: addr.Name}, t
+}
+
+// from: go/src/pkg/net/unixsock_posix.go
+
+// SockaddrToUnixAddr converts a syscall.Sockaddr to a net.UnixAddr
+// Returns nil if conversion fails.
+func SockaddrToUnixAddr(sa syscall.Sockaddr) *net.UnixAddr {
+	if s, ok := sa.(*syscall.SockaddrUnix); ok {
+		return &net.UnixAddr{Name: s.Name, Net: "unix"}
+	}
+	return nil
+}
+
+// SockaddrToUnixgramAddr converts a syscall.Sockaddr to a net.UnixAddr
+// Returns nil if conversion fails.
+func SockaddrToUnixgramAddr(sa syscall.Sockaddr) *net.UnixAddr {
+	if s, ok := sa.(*syscall.SockaddrUnix); ok {
+		return &net.UnixAddr{Name: s.Name, Net: "unixgram"}
+	}
+	return nil
+}
+
+// SockaddrToUnixpacketAddr converts a syscall.Sockaddr to a net.UnixAddr
+// Returns nil if conversion fails.
+func SockaddrToUnixpacketAddr(sa syscall.Sockaddr) *net.UnixAddr {
+	if s, ok := sa.(*syscall.SockaddrUnix); ok {
+		return &net.UnixAddr{Name: s.Name, Net: "unixpacket"}
+	}
+	return nil
+}
+
+// from: go/src/pkg/net/ipsock.go
+
+// IP6ZoneToString converts an IP6 Zone syscall int to a net string
+// returns "" if zone is 0
+func IP6ZoneToString(zone int) string {
+	if zone == 0 {
+		return ""
+	}
+	if ifi, err := net.InterfaceByIndex(zone); err == nil {
+		return ifi.Name
+	}
+	return itod(uint(zone))
+}
+
+// IP6ZoneToInt converts an IP6 Zone net string to a syscall int
+// returns 0 if zone is ""
+func IP6ZoneToInt(zone string) int {
+	if zone == "" {
+		return 0
+	}
+	if ifi, err := net.InterfaceByName(zone); err == nil {
+		return ifi.Index
+	}
+	n, _, _ := dtoi(zone, 0)
+	return n
+}
+
+// from: go/src/pkg/net/parse.go
+
+// Convert i to decimal string.
+func itod(i uint) string {
+	if i == 0 {
+		return "0"
+	}
+
+	// Assemble decimal in reverse order.
+	var b [32]byte
+	bp := len(b)
+	for ; i > 0; i /= 10 {
+		bp--
+		b[bp] = byte(i%10) + '0'
+	}
+
+	return string(b[bp:])
+}
+
+// Bigger than we need, not too big to worry about overflow
+const big = 0xFFFFFF
+
+// Decimal to integer starting at &s[i0].
+// Returns number, new offset, success.
+func dtoi(s string, i0 int) (n int, i int, ok bool) {
+	n = 0
+	for i = i0; i < len(s) && '0' <= s[i] && s[i] <= '9'; i++ {
+		n = n*10 + int(s[i]-'0')
+		if n >= big {
+			return 0, i, false
+		}
+	}
+	if i == i0 {
+		return 0, i, false
+	}
+	return n, i, true
+}