6b289a1423
This patch replaces the former prominent use of pointers by references wherever feasible. This has the following benefits: * The contract between caller and callee becomes more obvious. When passing a reference, the contract says that the argument cannot be a null pointer. The caller is responsible to ensure that. Therefore, the use of reference eliminates the need to add defensive null-pointer checks at the callee site, which sometimes merely exist to be on the safe side. The bottom line is that the code becomes easier to follow. * Reference members must be initialized via an object initializer, which promotes a programming style that avoids intermediate object- construction states. Within core, there are still a few pointers as member variables left though. E.g., caused by the late association of 'Platform_thread' objects with their 'Platform_pd' objects. * If no pointers are present as member variables, we don't need to manually provide declarations of a private copy constructor and an assignment operator to avoid -Weffc++ errors "class ... has pointer data members [-Werror=effc++]". This patch also changes a few system bindings on NOVA and Fiasco.OC, e.g., the return value of the global 'cap_map' accessor has become a reference. Hence, the patch touches a few places outside of core. Fixes #3135
110 lines
2.8 KiB
C++
110 lines
2.8 KiB
C++
/*
|
|
* \brief Support for communication over Unix domain sockets
|
|
* \author Norman Feske
|
|
* \date 2012-08-10
|
|
*/
|
|
|
|
/*
|
|
* Copyright (C) 2011-2017 Genode Labs GmbH
|
|
*
|
|
* This file is part of the Genode OS framework, which is distributed
|
|
* under the terms of the GNU Affero General Public License version 3.
|
|
*/
|
|
|
|
#ifndef _CORE__INCLUDE__SERVER_SOCKET_PAIR_H_
|
|
#define _CORE__INCLUDE__SERVER_SOCKET_PAIR_H_
|
|
|
|
/* Linux syscall bindings */
|
|
#include <core_linux_syscalls.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/un.h>
|
|
|
|
/* base-internal includes */
|
|
#include <base/internal/socket_descriptor_registry.h>
|
|
#include <base/internal/server_socket_pair.h>
|
|
|
|
/* core-local includes */
|
|
#include <resource_path.h>
|
|
|
|
|
|
/**
|
|
* Utility: Create socket address for server entrypoint at thread ID
|
|
*/
|
|
struct Uds_addr : sockaddr_un
|
|
{
|
|
Uds_addr(long thread_id)
|
|
:
|
|
sockaddr_un({.sun_family = AF_UNIX, .sun_path = { }})
|
|
{
|
|
Genode::snprintf(sun_path, sizeof(sun_path), "%s/ep-%ld",
|
|
resource_path(), thread_id);
|
|
}
|
|
};
|
|
|
|
|
|
/**
|
|
* Utility: Create named socket pair for given unique ID
|
|
*/
|
|
static inline Genode::Socket_pair create_server_socket_pair(long id)
|
|
{
|
|
Genode::Socket_pair socket_pair;
|
|
|
|
/*
|
|
* Main thread uses 'Ipc_server' for 'sleep_forever()' only. No need for
|
|
* binding.
|
|
*/
|
|
if (id == -1)
|
|
return socket_pair;
|
|
|
|
Uds_addr addr(id);
|
|
|
|
/*
|
|
* Create server-side socket
|
|
*/
|
|
socket_pair.server_sd = lx_socket(AF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC, 0);
|
|
if (socket_pair.server_sd < 0) {
|
|
PRAW("Error: Could not create server-side socket (ret=%d)", socket_pair.server_sd);
|
|
class Server_socket_failed { };
|
|
throw Server_socket_failed();
|
|
}
|
|
|
|
/* make sure bind succeeds */
|
|
lx_unlink(addr.sun_path);
|
|
|
|
int const bind_ret = lx_bind(socket_pair.server_sd, (sockaddr *)&addr, sizeof(addr));
|
|
if (bind_ret < 0) {
|
|
PRAW("Error: Could not bind server socket (ret=%d)", bind_ret);
|
|
class Bind_failed { };
|
|
throw Bind_failed();
|
|
}
|
|
|
|
/*
|
|
* Create client-side socket
|
|
*/
|
|
socket_pair.client_sd = lx_socket(AF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC, 0);
|
|
if (socket_pair.client_sd < 0) {
|
|
PRAW("Error: Could not create client-side socket (ret=%d)", socket_pair.client_sd);
|
|
class Client_socket_failed { };
|
|
throw Client_socket_failed();
|
|
}
|
|
|
|
int const conn_ret = lx_connect(socket_pair.client_sd, (sockaddr *)&addr, sizeof(addr));
|
|
if (conn_ret < 0) {
|
|
PRAW("Error: Could not connect client-side socket (ret=%d)", conn_ret);
|
|
class Connect_failed { };
|
|
throw Connect_failed();
|
|
}
|
|
|
|
socket_pair.client_sd = Genode::ep_sd_registry().try_associate(socket_pair.client_sd, id);
|
|
|
|
/*
|
|
* Wipe Unix domain socket from the file system. It will live as long as
|
|
* there exist references to it in the form of file descriptors.
|
|
*/
|
|
lx_unlink(addr.sun_path);
|
|
|
|
return socket_pair;
|
|
}
|
|
|
|
#endif /* _CORE__INCLUDE__SERVER_SOCKET_PAIR_H_ */
|