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/*
* InspIRCd -- Internet Relay Chat Daemon
*
* Copyright (C) 2009 Daniel De Graaf <danieldg@inspircd.org>
* Copyright (C) 2007-2008 Craig Edwards <craigedwards@brainbox.cc>
*
* This file is part of InspIRCd. InspIRCd is free software: you can
* redistribute it and/or modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "inspircd.h"
#include "exitcodes.h"
#include <sys/epoll.h>
#include <ulimit.h>
#include <iostream>
/** A specialisation of the SocketEngine class, designed to use linux 2.6 epoll().
*/
namespace
{
int EngineHandle;
/** These are used by epoll() to hold socket events
*/
std::vector<struct epoll_event> events(1);
}
void SocketEngine::Init()
{
// MAX_DESCRIPTORS is mainly used for display purposes, no problem if ulimit() fails and returns a negative number
MAX_DESCRIPTORS = ulimit(4, 0);
// 128 is not a maximum, just a hint at the eventual number of sockets that may be polled,
// and it is completely ignored by 2.6.8 and later kernels, except it must be larger than zero.
EngineHandle = epoll_create(128);
if (EngineHandle == -1)
{
ServerInstance->Logs->Log("SOCKET", LOG_DEFAULT, "ERROR: Could not initialize socket engine: %s", strerror(errno));
ServerInstance->Logs->Log("SOCKET", LOG_DEFAULT, "ERROR: Your kernel probably does not have the proper features. This is a fatal error, exiting now.");
std::cout << "ERROR: Could not initialize epoll socket engine: " << strerror(errno) << std::endl;
std::cout << "ERROR: Your kernel probably does not have the proper features. This is a fatal error, exiting now." << std::endl;
ServerInstance->QuickExit(EXIT_STATUS_SOCKETENGINE);
}
}
void SocketEngine::RecoverFromFork()
{
}
void SocketEngine::Deinit()
{
Close(EngineHandle);
}
static unsigned mask_to_epoll(int event_mask)
{
unsigned rv = 0;
if (event_mask & (FD_WANT_POLL_READ | FD_WANT_POLL_WRITE | FD_WANT_SINGLE_WRITE))
{
// we need to use standard polling on this FD
if (event_mask & (FD_WANT_POLL_READ | FD_WANT_FAST_READ))
rv |= EPOLLIN;
if (event_mask & (FD_WANT_POLL_WRITE | FD_WANT_FAST_WRITE | FD_WANT_SINGLE_WRITE))
rv |= EPOLLOUT;
}
else
{
// we can use edge-triggered polling on this FD
rv = EPOLLET;
if (event_mask & (FD_WANT_FAST_READ | FD_WANT_EDGE_READ))
rv |= EPOLLIN;
if (event_mask & (FD_WANT_FAST_WRITE | FD_WANT_EDGE_WRITE))
rv |= EPOLLOUT;
}
return rv;
}
bool SocketEngine::AddFd(EventHandler* eh, int event_mask)
{
int fd = eh->GetFd();
if (fd < 0)
{
ServerInstance->Logs->Log("SOCKET", LOG_DEBUG, "AddFd out of range: (fd: %d)", fd);
return false;
}
if (!SocketEngine::AddFdRef(eh))
{
ServerInstance->Logs->Log("SOCKET", LOG_DEBUG, "Attempt to add duplicate fd: %d", fd);
return false;
}
struct epoll_event ev;
memset(&ev, 0, sizeof(ev));
ev.events = mask_to_epoll(event_mask);
ev.data.ptr = static_cast<void*>(eh);
int i = epoll_ctl(EngineHandle, EPOLL_CTL_ADD, fd, &ev);
if (i < 0)
{
ServerInstance->Logs->Log("SOCKET", LOG_DEBUG, "Error adding fd: %d to socketengine: %s", fd, strerror(errno));
return false;
}
ServerInstance->Logs->Log("SOCKET", LOG_DEBUG, "New file descriptor: %d", fd);
eh->SetEventMask(event_mask);
ResizeDouble(events);
return true;
}
void SocketEngine::OnSetEvent(EventHandler* eh, int old_mask, int new_mask)
{
unsigned old_events = mask_to_epoll(old_mask);
unsigned new_events = mask_to_epoll(new_mask);
if (old_events != new_events)
{
// ok, we actually have something to tell the kernel about
struct epoll_event ev;
memset(&ev, 0, sizeof(ev));
ev.events = new_events;
ev.data.ptr = static_cast<void*>(eh);
epoll_ctl(EngineHandle, EPOLL_CTL_MOD, eh->GetFd(), &ev);
}
}
void SocketEngine::DelFd(EventHandler* eh)
{
int fd = eh->GetFd();
if (fd < 0)
{
ServerInstance->Logs->Log("SOCKET", LOG_DEBUG, "DelFd out of range: (fd: %d)", fd);
return;
}
// Do not initialize epoll_event because for EPOLL_CTL_DEL operations the event is ignored and can be NULL.
// In kernel versions before 2.6.9, the EPOLL_CTL_DEL operation required a non-NULL pointer in event,
// even though this argument is ignored. Since Linux 2.6.9, event can be specified as NULL when using EPOLL_CTL_DEL.
struct epoll_event ev;
int i = epoll_ctl(EngineHandle, EPOLL_CTL_DEL, fd, &ev);
if (i < 0)
{
ServerInstance->Logs->Log("SOCKET", LOG_DEBUG, "epoll_ctl can't remove socket: %s", strerror(errno));
}
SocketEngine::DelFdRef(eh);
ServerInstance->Logs->Log("SOCKET", LOG_DEBUG, "Remove file descriptor: %d", fd);
}
int SocketEngine::DispatchEvents()
{
int i = epoll_wait(EngineHandle, &events[0], events.size(), 1000);
ServerInstance->UpdateTime();
stats.TotalEvents += i;
for (int j = 0; j < i; j++)
{
// Copy these in case the vector gets resized and ev invalidated
const epoll_event ev = events[j];
EventHandler* const eh = static_cast<EventHandler*>(ev.data.ptr);
const int fd = eh->GetFd();
if (fd < 0)
continue;
if (ev.events & EPOLLHUP)
{
stats.ErrorEvents++;
eh->OnEventHandlerError(0);
continue;
}
if (ev.events & EPOLLERR)
{
stats.ErrorEvents++;
/* Get error number */
socklen_t codesize = sizeof(int);
int errcode;
if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &errcode, &codesize) < 0)
errcode = errno;
eh->OnEventHandlerError(errcode);
continue;
}
int mask = eh->GetEventMask();
if (ev.events & EPOLLIN)
mask &= ~FD_READ_WILL_BLOCK;
if (ev.events & EPOLLOUT)
{
mask &= ~FD_WRITE_WILL_BLOCK;
if (mask & FD_WANT_SINGLE_WRITE)
{
int nm = mask & ~FD_WANT_SINGLE_WRITE;
OnSetEvent(eh, mask, nm);
mask = nm;
}
}
eh->SetEventMask(mask);
if (ev.events & EPOLLIN)
{
eh->OnEventHandlerRead();
if (eh != GetRef(fd))
// whoa! we got deleted, better not give out the write event
continue;
}
if (ev.events & EPOLLOUT)
{
eh->OnEventHandlerWrite();
}
}
return i;
}
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