crashpad::UnixCredentialSocket Class Reference

Utilities for communicating over SO_PASSCRED enabled AF_UNIX sockets. More...

#include "util/linux/socket.h"

Static Public Member Functions
static bool	CreateCredentialSocketpair (ScopedFileHandle *s1, ScopedFileHandle *s2)
	Creates an AF_UNIX family socket pair with SO_PASSCRED set on each socket. More...
static int	SendMsg (int fd, const void *buf, size_t buf_size, const int *fds=nullptr, size_t fd_count=0)
	Wraps sendmsg() to send a message with file descriptors. More...
static bool	RecvMsg (int fd, void *buf, size_t buf_size, ucred *creds, std::vector< ScopedFileHandle > *fds=nullptr)
	Wraps recvmsg() to receive a message with file descriptors and credentials. More...

Static Public Attributes
static const size_t	kMaxSendRecvMsgFDs = 4
	The maximum number of file descriptors that may be sent/received with SendMsg() or RecvMsg().

Detailed Description

Utilities for communicating over SO_PASSCRED enabled AF_UNIX sockets.

Member Function Documentation

CreateCredentialSocketpair()

bool crashpad::UnixCredentialSocket::CreateCredentialSocketpair ( ScopedFileHandle *  s1, ScopedFileHandle *  s2  )

static

Creates an AF_UNIX family socket pair with SO_PASSCRED set on each socket.

Parameters

[out]	s1	One end of the connected pair.
[out]	s2	The other end of the connected pair.

Returns

true on success. Otherwise, false with a message logged.

RecvMsg()

bool crashpad::UnixCredentialSocket::RecvMsg ( int  fd, void *  buf, size_t  buf_size, ucred *  creds, std::vector< ScopedFileHandle > *  fds = nullptr  )

static

Wraps recvmsg() to receive a message with file descriptors and credentials.

This function is intended to be used with AF_UNIX family sockets. Up to kMaxSendRecvMsgFDs file descriptors may be received (via SCM_RIGHTS). The socket must have SO_PASSCRED set.

Parameters

[in]	fd	The file descriptor to receive the message on.
[out]	buf	The buffer to fill with the message.
[in]	buf_size	The size of the message.
[out]	creds	The credentials of the sender.
[out]	fds	The recieved file descriptors. Optional. If nullptr, all received file descriptors will be closed.

Returns

true on success. Otherwise, false, with a message logged. No message will be logged if the message was detected to be an EOF condition triggered by all clients disconnecting. This case is indistinguishable from misuses of this interface that haven't set SO_PASSCRED on fd.

SendMsg()

int crashpad::UnixCredentialSocket::SendMsg ( int  fd, const void *  buf, size_t  buf_size, const int *  fds = nullptr, size_t  fd_count = 0  )

static

Wraps sendmsg() to send a message with file descriptors.

This function is intended for use with AF_UNIX family sockets and passes file descriptors with SCM_RIGHTS.

This function may be used in a compromised context.

Parameters

[in]	fd	The file descriptor to write the message to.
[in]	buf	The buffer containing the message.
[in]	buf_size	The size of the message.
[in]	fds	An array of at most kMaxSendRecvMsgFDs file descriptors. Optional.
[in]	fd_count	The number of file descriptors in fds. Required only if fds was set.

Returns

0 on success or an error code on failure.

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The documentation for this class was generated from the following files:

• util/linux/socket.h
• util/linux/socket.cc