| // Copyright 2009 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. |
| |
| //go:build unix || (js && wasm) || windows |
| |
| package net |
| |
| import ( |
| "context" |
| "net/netip" |
| "syscall" |
| ) |
| |
| func sockaddrToUDP(sa syscall.Sockaddr) Addr { |
| switch sa := sa.(type) { |
| case *syscall.SockaddrInet4: |
| return &UDPAddr{IP: sa.Addr[0:], Port: sa.Port} |
| case *syscall.SockaddrInet6: |
| return &UDPAddr{IP: sa.Addr[0:], Port: sa.Port, Zone: zoneCache.name(int(sa.ZoneId))} |
| } |
| return nil |
| } |
| |
| func (a *UDPAddr) family() int { |
| if a == nil || len(a.IP) <= IPv4len { |
| return syscall.AF_INET |
| } |
| if a.IP.To4() != nil { |
| return syscall.AF_INET |
| } |
| return syscall.AF_INET6 |
| } |
| |
| func (a *UDPAddr) sockaddr(family int) (syscall.Sockaddr, error) { |
| if a == nil { |
| return nil, nil |
| } |
| return ipToSockaddr(family, a.IP, a.Port, a.Zone) |
| } |
| |
| func (a *UDPAddr) toLocal(net string) sockaddr { |
| return &UDPAddr{loopbackIP(net), a.Port, a.Zone} |
| } |
| |
| func (c *UDPConn) readFrom(b []byte, addr *UDPAddr) (int, *UDPAddr, error) { |
| var n int |
| var err error |
| switch c.fd.family { |
| case syscall.AF_INET: |
| var from syscall.SockaddrInet4 |
| n, err = c.fd.readFromInet4(b, &from) |
| if err == nil { |
| ip := from.Addr // copy from.Addr; ip escapes, so this line allocates 4 bytes |
| *addr = UDPAddr{IP: ip[:], Port: from.Port} |
| } |
| case syscall.AF_INET6: |
| var from syscall.SockaddrInet6 |
| n, err = c.fd.readFromInet6(b, &from) |
| if err == nil { |
| ip := from.Addr // copy from.Addr; ip escapes, so this line allocates 16 bytes |
| *addr = UDPAddr{IP: ip[:], Port: from.Port, Zone: zoneCache.name(int(from.ZoneId))} |
| } |
| } |
| if err != nil { |
| // No sockaddr, so don't return UDPAddr. |
| addr = nil |
| } |
| return n, addr, err |
| } |
| |
| func (c *UDPConn) readFromAddrPort(b []byte) (n int, addr netip.AddrPort, err error) { |
| var ip netip.Addr |
| var port int |
| switch c.fd.family { |
| case syscall.AF_INET: |
| var from syscall.SockaddrInet4 |
| n, err = c.fd.readFromInet4(b, &from) |
| if err == nil { |
| ip = netip.AddrFrom4(from.Addr) |
| port = from.Port |
| } |
| case syscall.AF_INET6: |
| var from syscall.SockaddrInet6 |
| n, err = c.fd.readFromInet6(b, &from) |
| if err == nil { |
| ip = netip.AddrFrom16(from.Addr).WithZone(zoneCache.name(int(from.ZoneId))) |
| port = from.Port |
| } |
| } |
| if err == nil { |
| addr = netip.AddrPortFrom(ip, uint16(port)) |
| } |
| return n, addr, err |
| } |
| |
| func (c *UDPConn) readMsg(b, oob []byte) (n, oobn, flags int, addr netip.AddrPort, err error) { |
| switch c.fd.family { |
| case syscall.AF_INET: |
| var sa syscall.SockaddrInet4 |
| n, oobn, flags, err = c.fd.readMsgInet4(b, oob, 0, &sa) |
| ip := netip.AddrFrom4(sa.Addr) |
| addr = netip.AddrPortFrom(ip, uint16(sa.Port)) |
| case syscall.AF_INET6: |
| var sa syscall.SockaddrInet6 |
| n, oobn, flags, err = c.fd.readMsgInet6(b, oob, 0, &sa) |
| ip := netip.AddrFrom16(sa.Addr).WithZone(zoneCache.name(int(sa.ZoneId))) |
| addr = netip.AddrPortFrom(ip, uint16(sa.Port)) |
| } |
| return |
| } |
| |
| func (c *UDPConn) writeTo(b []byte, addr *UDPAddr) (int, error) { |
| if c.fd.isConnected { |
| return 0, ErrWriteToConnected |
| } |
| if addr == nil { |
| return 0, errMissingAddress |
| } |
| |
| switch c.fd.family { |
| case syscall.AF_INET: |
| sa, err := ipToSockaddrInet4(addr.IP, addr.Port) |
| if err != nil { |
| return 0, err |
| } |
| return c.fd.writeToInet4(b, &sa) |
| case syscall.AF_INET6: |
| sa, err := ipToSockaddrInet6(addr.IP, addr.Port, addr.Zone) |
| if err != nil { |
| return 0, err |
| } |
| return c.fd.writeToInet6(b, &sa) |
| default: |
| return 0, &AddrError{Err: "invalid address family", Addr: addr.IP.String()} |
| } |
| } |
| |
| func (c *UDPConn) writeToAddrPort(b []byte, addr netip.AddrPort) (int, error) { |
| if c.fd.isConnected { |
| return 0, ErrWriteToConnected |
| } |
| if !addr.IsValid() { |
| return 0, errMissingAddress |
| } |
| |
| switch c.fd.family { |
| case syscall.AF_INET: |
| sa, err := addrPortToSockaddrInet4(addr) |
| if err != nil { |
| return 0, err |
| } |
| return c.fd.writeToInet4(b, &sa) |
| case syscall.AF_INET6: |
| sa, err := addrPortToSockaddrInet6(addr) |
| if err != nil { |
| return 0, err |
| } |
| return c.fd.writeToInet6(b, &sa) |
| default: |
| return 0, &AddrError{Err: "invalid address family", Addr: addr.Addr().String()} |
| } |
| } |
| |
| func (c *UDPConn) writeMsg(b, oob []byte, addr *UDPAddr) (n, oobn int, err error) { |
| if c.fd.isConnected && addr != nil { |
| return 0, 0, ErrWriteToConnected |
| } |
| if !c.fd.isConnected && addr == nil { |
| return 0, 0, errMissingAddress |
| } |
| sa, err := addr.sockaddr(c.fd.family) |
| if err != nil { |
| return 0, 0, err |
| } |
| return c.fd.writeMsg(b, oob, sa) |
| } |
| |
| func (c *UDPConn) writeMsgAddrPort(b, oob []byte, addr netip.AddrPort) (n, oobn int, err error) { |
| if c.fd.isConnected && addr.IsValid() { |
| return 0, 0, ErrWriteToConnected |
| } |
| if !c.fd.isConnected && !addr.IsValid() { |
| return 0, 0, errMissingAddress |
| } |
| |
| switch c.fd.family { |
| case syscall.AF_INET: |
| sa, err := addrPortToSockaddrInet4(addr) |
| if err != nil { |
| return 0, 0, err |
| } |
| return c.fd.writeMsgInet4(b, oob, &sa) |
| case syscall.AF_INET6: |
| sa, err := addrPortToSockaddrInet6(addr) |
| if err != nil { |
| return 0, 0, err |
| } |
| return c.fd.writeMsgInet6(b, oob, &sa) |
| default: |
| return 0, 0, &AddrError{Err: "invalid address family", Addr: addr.Addr().String()} |
| } |
| } |
| |
| func (sd *sysDialer) dialUDP(ctx context.Context, laddr, raddr *UDPAddr) (*UDPConn, error) { |
| fd, err := internetSocket(ctx, sd.network, laddr, raddr, syscall.SOCK_DGRAM, 0, "dial", sd.Dialer.Control) |
| if err != nil { |
| return nil, err |
| } |
| return newUDPConn(fd), nil |
| } |
| |
| func (sl *sysListener) listenUDP(ctx context.Context, laddr *UDPAddr) (*UDPConn, error) { |
| fd, err := internetSocket(ctx, sl.network, laddr, nil, syscall.SOCK_DGRAM, 0, "listen", sl.ListenConfig.Control) |
| if err != nil { |
| return nil, err |
| } |
| return newUDPConn(fd), nil |
| } |
| |
| func (sl *sysListener) listenMulticastUDP(ctx context.Context, ifi *Interface, gaddr *UDPAddr) (*UDPConn, error) { |
| fd, err := internetSocket(ctx, sl.network, gaddr, nil, syscall.SOCK_DGRAM, 0, "listen", sl.ListenConfig.Control) |
| if err != nil { |
| return nil, err |
| } |
| c := newUDPConn(fd) |
| if ip4 := gaddr.IP.To4(); ip4 != nil { |
| if err := listenIPv4MulticastUDP(c, ifi, ip4); err != nil { |
| c.Close() |
| return nil, err |
| } |
| } else { |
| if err := listenIPv6MulticastUDP(c, ifi, gaddr.IP); err != nil { |
| c.Close() |
| return nil, err |
| } |
| } |
| return c, nil |
| } |
| |
| func listenIPv4MulticastUDP(c *UDPConn, ifi *Interface, ip IP) error { |
| if ifi != nil { |
| if err := setIPv4MulticastInterface(c.fd, ifi); err != nil { |
| return err |
| } |
| } |
| if err := setIPv4MulticastLoopback(c.fd, false); err != nil { |
| return err |
| } |
| if err := joinIPv4Group(c.fd, ifi, ip); err != nil { |
| return err |
| } |
| return nil |
| } |
| |
| func listenIPv6MulticastUDP(c *UDPConn, ifi *Interface, ip IP) error { |
| if ifi != nil { |
| if err := setIPv6MulticastInterface(c.fd, ifi); err != nil { |
| return err |
| } |
| } |
| if err := setIPv6MulticastLoopback(c.fd, false); err != nil { |
| return err |
| } |
| if err := joinIPv6Group(c.fd, ifi, ip); err != nil { |
| return err |
| } |
| return nil |
| } |
