c09cd2d1a7
This patch, which was originally created by Christian Helmuth, represents the first step towards using SCM rights as capability mechanism on Linux. It employs the SCM rights mechanism for transmitting a reply capability to the server as argument of each IPC call. The server will then send its respond to this reply file descriptor. This way, the reply channel does not need to be globally visible anymore.
209 lines
4.1 KiB
C++
209 lines
4.1 KiB
C++
/*
|
|
* \brief Socket-based IPC implementation for Linux
|
|
* \author Norman Feske
|
|
* \author Christian Helmuth
|
|
* \date 2011-10-11
|
|
*
|
|
* The current request message layout is:
|
|
*
|
|
* long server_local_name;
|
|
* long client_thread_id;
|
|
* int opcode;
|
|
* ...payload...
|
|
*
|
|
* Response messages look like this:
|
|
*
|
|
* long scratch_word;
|
|
* int exc_code;
|
|
* ...payload...
|
|
*
|
|
* All fields are naturally aligned, i.e., aligend on 4 or 8 byte boundaries on
|
|
* 32-bit resp. 64-bit systems.
|
|
*/
|
|
|
|
/*
|
|
* Copyright (C) 2011-2012 Genode Labs GmbH
|
|
*
|
|
* This file is part of the Genode OS framework, which is distributed
|
|
* under the terms of the GNU General Public License version 2.
|
|
*/
|
|
|
|
/* Genode includes */
|
|
#include <base/ipc.h>
|
|
#include <base/thread.h>
|
|
#include <base/blocking.h>
|
|
|
|
/* Linux includes */
|
|
#include <sys/socket.h>
|
|
#include <sys/types.h>
|
|
#include <sys/un.h>
|
|
#include <errno.h>
|
|
|
|
#include <linux_socket.h>
|
|
#include <linux_syscalls.h>
|
|
|
|
|
|
using namespace Genode;
|
|
|
|
|
|
/*****************
|
|
** Ipc_ostream **
|
|
*****************/
|
|
|
|
/*
|
|
* XXX This class will be removed soon.
|
|
*/
|
|
|
|
void Ipc_ostream::_prepare_next_send()
|
|
{
|
|
PRAW("unexpected call to %s (%p)", __PRETTY_FUNCTION__, this);
|
|
}
|
|
|
|
|
|
void Ipc_ostream::_send()
|
|
{
|
|
PRAW("unexpected call to %s (%p)", __PRETTY_FUNCTION__, this);
|
|
}
|
|
|
|
|
|
Ipc_ostream::Ipc_ostream(Native_capability dst, Msgbuf_base *snd_msg):
|
|
Ipc_marshaller(snd_msg->buf, snd_msg->size()), _snd_msg(snd_msg), _dst(dst)
|
|
{ }
|
|
|
|
|
|
/*****************
|
|
** Ipc_istream **
|
|
*****************/
|
|
|
|
/*
|
|
* XXX This class will be removed soon.
|
|
*/
|
|
|
|
void Ipc_istream::_prepare_next_receive()
|
|
{
|
|
PRAW("unexpected call to %s (%p)", __PRETTY_FUNCTION__, this);
|
|
}
|
|
|
|
|
|
void Ipc_istream::_wait()
|
|
{
|
|
PRAW("unexpected call to %s (%p)", __PRETTY_FUNCTION__, this);
|
|
}
|
|
|
|
|
|
Ipc_istream::Ipc_istream(Msgbuf_base *rcv_msg)
|
|
: Ipc_unmarshaller(rcv_msg->buf, rcv_msg->size()),
|
|
Native_capability(lx_gettid(), 0),
|
|
_rcv_msg(rcv_msg)
|
|
{ }
|
|
|
|
|
|
Ipc_istream::~Ipc_istream() { }
|
|
|
|
|
|
/****************
|
|
** Ipc_client **
|
|
****************/
|
|
|
|
void Ipc_client::_prepare_next_call()
|
|
{
|
|
/* prepare next request in buffer */
|
|
long local_name = Ipc_ostream::_dst.local_name();
|
|
long tid = Native_capability::dst();
|
|
|
|
_write_offset = 0;
|
|
_write_to_buf(local_name);
|
|
_write_to_buf(tid);
|
|
|
|
/* prepare response buffer */
|
|
_read_offset = sizeof(long);
|
|
}
|
|
|
|
|
|
void Ipc_client::_call()
|
|
{
|
|
if (Ipc_ostream::_dst.valid()) {
|
|
lx_call(Ipc_ostream::_dst.dst(),
|
|
_snd_msg->buf, _write_offset,
|
|
_rcv_msg->buf, _rcv_msg->size());
|
|
}
|
|
_prepare_next_call();
|
|
}
|
|
|
|
|
|
Ipc_client::Ipc_client(Native_capability const &srv,
|
|
Msgbuf_base *snd_msg, Msgbuf_base *rcv_msg)
|
|
: Ipc_istream(rcv_msg), Ipc_ostream(srv, snd_msg), _result(0)
|
|
{
|
|
_prepare_next_call();
|
|
}
|
|
|
|
|
|
/****************
|
|
** Ipc_server **
|
|
****************/
|
|
|
|
void Ipc_server::_prepare_next_reply_wait()
|
|
{
|
|
/* skip server-local name */
|
|
_read_offset = sizeof(long);
|
|
|
|
/* read client thread id from request buffer */
|
|
long tid = 0;
|
|
if (_reply_needed) {
|
|
_read_from_buf(tid);
|
|
Ipc_ostream::_dst = Native_capability(tid, 0); /* only _tid member is used */
|
|
}
|
|
|
|
/* prepare next reply */
|
|
_write_offset = 0;
|
|
long local_name = Ipc_ostream::_dst.local_name();
|
|
_write_to_buf(local_name); /* XXX unused, needed by de/marshaller */
|
|
|
|
/* leave space for exc code at the beginning of the msgbuf */
|
|
_write_offset += align_natural(sizeof(int));
|
|
}
|
|
|
|
|
|
void Ipc_server::_wait()
|
|
{
|
|
/* wait for new server request */
|
|
try {
|
|
lx_wait(_rcv_cs, _rcv_msg->buf, _rcv_msg->size());
|
|
} catch (Blocking_canceled) { }
|
|
|
|
/* now we have a request to reply, determine reply destination */
|
|
_reply_needed = true;
|
|
_prepare_next_reply_wait();
|
|
}
|
|
|
|
|
|
void Ipc_server::_reply()
|
|
{
|
|
try {
|
|
lx_reply(_rcv_cs, _snd_msg->buf, _write_offset);
|
|
} catch (Ipc_error) { }
|
|
|
|
_prepare_next_reply_wait();
|
|
}
|
|
|
|
|
|
void Ipc_server::_reply_wait()
|
|
{
|
|
/* when first called, there was no request yet */
|
|
if (_reply_needed)
|
|
lx_reply(_rcv_cs, _snd_msg->buf, _write_offset);
|
|
|
|
_wait();
|
|
}
|
|
|
|
|
|
Ipc_server::Ipc_server(Msgbuf_base *snd_msg, Msgbuf_base *rcv_msg)
|
|
: Ipc_istream(rcv_msg),
|
|
Ipc_ostream(Native_capability(), snd_msg), _reply_needed(false)
|
|
{
|
|
_rcv_cs.socket(lx_server_socket(Thread_base::myself()));
|
|
|
|
_prepare_next_reply_wait();
|
|
}
|