ostinato/server/pcapsession.cpp
2019-08-18 13:13:39 +05:30

87 lines
2.4 KiB
C++

/*
Copyright (C) 2019 Srivats P.
This file is part of "Ostinato"
This 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, either version 3 of the License, or
(at your option) any later version.
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 "pcapsession.h"
#ifdef Q_OS_UNIX
#include <signal.h>
#include <typeinfo>
#define MY_BREAK_SIGNAL SIGUSR1
QHash<ThreadId, bool> PcapSession::signalSeen_;
void PcapSession::preRun()
{
// Should be called in the thread's context
thread_ = pthread_self();
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sigemptyset(&sa.sa_mask);
sa.sa_handler = PcapSession::signalBreakHandler;
if (!sigaction(MY_BREAK_SIGNAL, &sa, NULL)) {
signalSeen_[thread_] = false;
qDebug("Break signal handler installed");
}
else
qWarning("Failed to install MY_BREAK_SIGNAL handler");
}
void PcapSession::postRun()
{
// Should be called in the thread's context
ThreadId id = pthread_self();
qDebug("In %s::%s", typeid(*this).name(), __FUNCTION__);
if (!signalSeen_.contains(id)) {
qWarning("Thread not found in signalSeen");
return;
}
bool &seen = signalSeen_[id];
// XXX: don't exit the thread until we see the signal; if we don't
// some platforms will crash
if (!seen) {
qDebug("Wait for signal");
while (!seen)
QThread::msleep(10);
}
signalSeen_.remove(id);
qDebug("Signal seen and handled");
}
void PcapSession::stop(pcap_t *handle)
{
// Should be called OUTSIDE the thread's context
// XXX: As per the man page for pcap_breakloop, we need both
// pcap_breakloop and a mechanism to interrupt system calls;
// we use a signal for the latter
// TODO: If the signal mechanism doesn't work, we could try
// pthread_cancel(thread_);
pcap_breakloop(handle);
pthread_kill(thread_.nativeId(), MY_BREAK_SIGNAL);
}
void PcapSession::signalBreakHandler(int /*signum*/)
{
qDebug("In %s", __FUNCTION__);
signalSeen_[pthread_self()] = true;
}
#endif