distribution/vendor/golang.org/x/sys/unix/sockcmsg_unix.go
Sebastiaan van Stijn 345be95498
vendor: golang.org/x/net v0.4.0
golang.org/x/net contains a fix for CVE-2022-41717, which was addressed
in stdlib in go1.19.4 and go1.18.9;

> net/http: limit canonical header cache by bytes, not entries
>
> An attacker can cause excessive memory growth in a Go server accepting
> HTTP/2 requests.
>
> HTTP/2 server connections contain a cache of HTTP header keys sent by
> the client. While the total number of entries in this cache is capped,
> an attacker sending very large keys can cause the server to allocate
> approximately 64 MiB per open connection.
>
> This issue is also fixed in golang.org/x/net/http2 v0.4.0,
> for users manually configuring HTTP/2.

full diff: https://github.com/golang/net/compare/v0.2.0...v0.4.0

other dependency updates (due to (circular) dependencies):

- golang.org/x/sys v0.3.0: https://github.com/golang/sys/compare/3c1f35247d10...v0.3.0
- golang.org/x/text v0.5.0: https://github.com/golang/text/compare/v0.3.7...v0.5.0

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2022-12-08 10:39:04 +01:00

107 lines
3.2 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.
//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris || zos
// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris zos
// Socket control messages
package unix
import (
"unsafe"
)
// 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 (h *Cmsghdr) data(offset uintptr) unsafe.Pointer {
return unsafe.Pointer(uintptr(unsafe.Pointer(h)) + uintptr(cmsgAlignOf(SizeofCmsghdr)) + offset)
}
// 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
}
// ParseOneSocketControlMessage parses a single socket control message from b, returning the message header,
// message data (a slice of b), and the remainder of b after that single message.
// When there are no remaining messages, len(remainder) == 0.
func ParseOneSocketControlMessage(b []byte) (hdr Cmsghdr, data []byte, remainder []byte, err error) {
h, dbuf, err := socketControlMessageHeaderAndData(b)
if err != nil {
return Cmsghdr{}, nil, nil, err
}
if i := cmsgAlignOf(int(h.Len)); i < len(b) {
remainder = b[i:]
}
return *h, dbuf, remainder, 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))
for i, fd := range fds {
*(*int32)(h.data(4 * uintptr(i))) = int32(fd)
}
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
}