feat(application): inital commit

vendor/golang.org/x/net/ipv4/payload_cmsg.go

@@ -0,0 +1,85 @@
+// Copyright 2012 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 aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris || zos
+// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris zos
+
+package ipv4
+
+import (
+	"net"
+
+	"golang.org/x/net/internal/socket"
+)
+
+// ReadFrom reads a payload of the received IPv4 datagram, from the
+// endpoint c, copying the payload into b. It returns the number of
+// bytes copied into b, the control message cm and the source address
+// src of the received datagram.
+func (c *payloadHandler) ReadFrom(b []byte) (n int, cm *ControlMessage, src net.Addr, err error) {
+	if !c.ok() {
+		return 0, nil, nil, errInvalidConn
+	}
+	c.rawOpt.RLock()
+	m := socket.Message{
+		OOB: NewControlMessage(c.rawOpt.cflags),
+	}
+	c.rawOpt.RUnlock()
+	switch c.PacketConn.(type) {
+	case *net.UDPConn:
+		m.Buffers = [][]byte{b}
+		if err := c.RecvMsg(&m, 0); err != nil {
+			return 0, nil, nil, &net.OpError{Op: "read", Net: c.PacketConn.LocalAddr().Network(), Source: c.PacketConn.LocalAddr(), Err: err}
+		}
+	case *net.IPConn:
+		h := make([]byte, HeaderLen)
+		m.Buffers = [][]byte{h, b}
+		if err := c.RecvMsg(&m, 0); err != nil {
+			return 0, nil, nil, &net.OpError{Op: "read", Net: c.PacketConn.LocalAddr().Network(), Source: c.PacketConn.LocalAddr(), Err: err}
+		}
+		hdrlen := int(h[0]&0x0f) << 2
+		if hdrlen > len(h) {
+			d := hdrlen - len(h)
+			copy(b, b[d:])
+			m.N -= d
+		} else {
+			m.N -= hdrlen
+		}
+	default:
+		return 0, nil, nil, &net.OpError{Op: "read", Net: c.PacketConn.LocalAddr().Network(), Source: c.PacketConn.LocalAddr(), Err: errInvalidConnType}
+	}
+	if m.NN > 0 {
+		if compatFreeBSD32 {
+			adjustFreeBSD32(&m)
+		}
+		cm = new(ControlMessage)
+		if err := cm.Parse(m.OOB[:m.NN]); err != nil {
+			return 0, nil, nil, &net.OpError{Op: "read", Net: c.PacketConn.LocalAddr().Network(), Source: c.PacketConn.LocalAddr(), Err: err}
+		}
+		cm.Src = netAddrToIP4(m.Addr)
+	}
+	return m.N, cm, m.Addr, nil
+}
+
+// WriteTo writes a payload of the IPv4 datagram, to the destination
+// address dst through the endpoint c, copying the payload from b. It
+// returns the number of bytes written. The control message cm allows
+// the datagram path and the outgoing interface to be specified.
+// Currently only Darwin and Linux support this. The cm may be nil if
+// control of the outgoing datagram is not required.
+func (c *payloadHandler) WriteTo(b []byte, cm *ControlMessage, dst net.Addr) (n int, err error) {
+	if !c.ok() {
+		return 0, errInvalidConn
+	}
+	m := socket.Message{
+		Buffers: [][]byte{b},
+		OOB:     cm.Marshal(),
+		Addr:    dst,
+	}
+	err = c.SendMsg(&m, 0)
+	if err != nil {
+		err = &net.OpError{Op: "write", Net: c.PacketConn.LocalAddr().Network(), Source: c.PacketConn.LocalAddr(), Addr: opAddr(dst), Err: err}
+	}
+	return m.N, err
+}