plugeth/vendor/golang.org/x/sys/unix/sockcmsg_unix.go
Péter Szilágyi 289b30715d Godeps, vendor: convert dependency management to trash (#3198)
This commit converts the dependency management from Godeps to the vendor
folder, also switching the tool from godep to trash. Since the upstream tool
lacks a few features proposed via a few PRs, until those PRs are merged in
(if), use github.com/karalabe/trash.

You can update dependencies via trash --update.

All dependencies have been updated to their latest version.

Parts of the build system are reworked to drop old notions of Godeps and
invocation of the go vet command so that it doesn't run against the vendor
folder, as that will just blow up during vetting.

The conversion drops OpenCL (and hence GPU mining support) from ethash and our
codebase. The short reasoning is that there's noone to maintain and having
opencl libs in our deps messes up builds as go install ./... tries to build
them, failing with unsatisfied link errors for the C OpenCL deps.

golang.org/x/net/context is not vendored in. We expect it to be fetched by the
user (i.e. using go get). To keep ci.go builds reproducible the package is
"vendored" in build/_vendor.
2016-10-28 19:05:01 +02:00

104 lines
2.9 KiB
Go

// Copyright 2011 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 darwin dragonfly freebsd linux netbsd openbsd solaris
// Socket control messages
package unix
import "unsafe"
// Round the length of a raw sockaddr up to align it properly.
func cmsgAlignOf(salen int) int {
salign := sizeofPtr
// NOTE: It seems like 64-bit Darwin and DragonFly BSD kernels
// still require 32-bit aligned access to network subsystem.
if darwin64Bit || dragonfly64Bit {
salign = 4
}
return (salen + salign - 1) & ^(salign - 1)
}
// CmsgLen returns the value to store in the Len field of the Cmsghdr
// structure, taking into account any necessary alignment.
func CmsgLen(datalen int) int {
return cmsgAlignOf(SizeofCmsghdr) + datalen
}
// CmsgSpace returns the number of bytes an ancillary element with
// payload of the passed data length occupies.
func CmsgSpace(datalen int) int {
return cmsgAlignOf(SizeofCmsghdr) + cmsgAlignOf(datalen)
}
func cmsgData(h *Cmsghdr) unsafe.Pointer {
return unsafe.Pointer(uintptr(unsafe.Pointer(h)) + uintptr(cmsgAlignOf(SizeofCmsghdr)))
}
// SocketControlMessage represents a socket control message.
type SocketControlMessage struct {
Header Cmsghdr
Data []byte
}
// ParseSocketControlMessage parses b as an array of socket control
// messages.
func ParseSocketControlMessage(b []byte) ([]SocketControlMessage, error) {
var msgs []SocketControlMessage
i := 0
for i+CmsgLen(0) <= len(b) {
h, dbuf, err := socketControlMessageHeaderAndData(b[i:])
if err != nil {
return nil, err
}
m := SocketControlMessage{Header: *h, Data: dbuf}
msgs = append(msgs, m)
i += cmsgAlignOf(int(h.Len))
}
return msgs, nil
}
func socketControlMessageHeaderAndData(b []byte) (*Cmsghdr, []byte, error) {
h := (*Cmsghdr)(unsafe.Pointer(&b[0]))
if h.Len < SizeofCmsghdr || uint64(h.Len) > uint64(len(b)) {
return nil, nil, EINVAL
}
return h, b[cmsgAlignOf(SizeofCmsghdr):h.Len], nil
}
// UnixRights encodes a set of open file descriptors into a socket
// control message for sending to another process.
func UnixRights(fds ...int) []byte {
datalen := len(fds) * 4
b := make([]byte, CmsgSpace(datalen))
h := (*Cmsghdr)(unsafe.Pointer(&b[0]))
h.Level = SOL_SOCKET
h.Type = SCM_RIGHTS
h.SetLen(CmsgLen(datalen))
data := cmsgData(h)
for _, fd := range fds {
*(*int32)(data) = int32(fd)
data = unsafe.Pointer(uintptr(data) + 4)
}
return b
}
// ParseUnixRights decodes a socket control message that contains an
// integer array of open file descriptors from another process.
func ParseUnixRights(m *SocketControlMessage) ([]int, error) {
if m.Header.Level != SOL_SOCKET {
return nil, EINVAL
}
if m.Header.Type != SCM_RIGHTS {
return nil, EINVAL
}
fds := make([]int, len(m.Data)>>2)
for i, j := 0, 0; i < len(m.Data); i += 4 {
fds[j] = int(*(*int32)(unsafe.Pointer(&m.Data[i])))
j++
}
return fds, nil
}