open-nomad/vendor/golang.org/x/net/ipv4/payload_cmsg.go
Seth Hoenig 435c0d9fc8 deps: Switch to Go modules for dependency management
This PR switches the Nomad repository from using govendor to Go modules
for managing dependencies. Aspects of the Nomad workflow remain pretty
much the same. The usual Makefile targets should continue to work as
they always did. The API submodule simply defers to the parent Nomad
version on the repository, keeping the semantics of API versioning that
currently exists.
2020-06-02 14:30:36 -05:00

85 lines
2.7 KiB
Go

// 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.
// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
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
}