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ostinato/server/pcapport.cpp

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/*
Copyright (C) 2010 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 "pcapport.h"
#include "devicemanager.h"
#include "packetbuffer.h"
#include <QtGlobal>
#ifdef Q_OS_WIN32
#include <windows.h>
#endif
pcap_if_t *PcapPort::deviceList_ = NULL;
#if defined(Q_OS_LINUX)
typedef struct timeval TimeStamp;
static void inline getTimeStamp(TimeStamp *stamp)
{
gettimeofday(stamp, NULL);
}
// Returns time diff in usecs between end and start
static long inline udiffTimeStamp(const TimeStamp *start, const TimeStamp *end)
{
struct timeval diff;
long usecs;
timersub(end, start, &diff);
usecs = diff.tv_usec;
if (diff.tv_sec)
usecs += diff.tv_sec*1e6;
return usecs;
}
#elif defined(Q_OS_WIN32)
static quint64 gTicksFreq;
typedef LARGE_INTEGER TimeStamp;
static void inline getTimeStamp(TimeStamp* stamp)
{
QueryPerformanceCounter(stamp);
}
static long inline udiffTimeStamp(const TimeStamp *start, const TimeStamp *end)
{
if (end->QuadPart >= start->QuadPart)
return (end->QuadPart - start->QuadPart)*long(1e6)/gTicksFreq;
else
{
// FIXME: incorrect! what's the max value for this counter before
// it rolls over?
return (start->QuadPart)*long(1e6)/gTicksFreq;
}
}
#else
typedef int TimeStamp;
static void inline getTimeStamp(TimeStamp*) {}
static long inline udiffTimeStamp(const TimeStamp*, const TimeStamp*) { return 0; }
#endif
PcapPort::PcapPort(int id, const char *device)
: AbstractPort(id, device)
{
monitorRx_ = new PortMonitor(device, kDirectionRx, &stats_);
monitorTx_ = new PortMonitor(device, kDirectionTx, &stats_);
transmitter_ = new PortTransmitter(device);
capturer_ = new PortCapturer(device);
emulXcvr_ = new EmulationTransceiver(device, deviceManager_);
if (!monitorRx_->handle() || !monitorTx_->handle())
isUsable_ = false;
if (!deviceList_)
{
char errbuf[PCAP_ERRBUF_SIZE];
if (pcap_findalldevs(&deviceList_, errbuf) == -1)
qDebug("Error in pcap_findalldevs_ex: %s\n", errbuf);
}
for (pcap_if_t *dev = deviceList_; dev != NULL; dev = dev->next)
{
if (strcmp(device, dev->name) == 0)
{
if (dev->name)
data_.set_name(dev->name);
if (dev->description)
data_.set_description(dev->description);
//! \todo set port IP addr also
}
}
}
void PcapPort::init()
{
if (!monitorTx_->isDirectional())
transmitter_->useExternalStats(&stats_);
transmitter_->setHandle(monitorRx_->handle());
updateNotes();
monitorRx_->start();
monitorTx_->start();
}
PcapPort::~PcapPort()
{
qDebug("In %s", __FUNCTION__);
if (monitorRx_)
monitorRx_->stop();
if (monitorTx_)
monitorTx_->stop();
delete emulXcvr_;
delete capturer_;
delete transmitter_;
if (monitorRx_)
monitorRx_->wait();
delete monitorRx_;
if (monitorTx_)
monitorTx_->wait();
delete monitorTx_;
}
void PcapPort::updateNotes()
{
QString notes;
if ((!monitorRx_->isPromiscuous()) || (!monitorTx_->isPromiscuous()))
notes.append("<li>Non Promiscuous Mode</li>");
if (!monitorRx_->isDirectional() && !hasExclusiveControl())
notes.append("<li><i>Rx Frames/Bytes</i>: Includes non Ostinato Tx pkts also (Tx by Ostinato are not included)</li>");
if (!monitorTx_->isDirectional() && !hasExclusiveControl())
notes.append("<li><i>Tx Frames/Bytes</i>: Only Ostinato Tx pkts (Tx by others NOT included)</li>");
if (notes.isEmpty())
data_.set_notes("");
else
data_.set_notes(QString("<b>Limitation(s)</b>"
"<ul>%1</ul>"
"Rx/Tx Rates are also subject to above limitation(s)").
arg(notes).toStdString());
}
bool PcapPort::setRateAccuracy(AbstractPort::Accuracy accuracy)
{
if (transmitter_->setRateAccuracy(accuracy)) {
AbstractPort::setRateAccuracy(accuracy);
return true;
}
return false;
}
void PcapPort::startDeviceEmulation()
{
emulXcvr_->start();
}
void PcapPort::stopDeviceEmulation()
{
emulXcvr_->stop();
}
int PcapPort::sendEmulationPacket(PacketBuffer *pktBuf)
{
return emulXcvr_->transmitPacket(pktBuf);
}
/*
* ------------------------------------------------------------------- *
* Port Monitor
* ------------------------------------------------------------------- *
*/
PcapPort::PortMonitor::PortMonitor(const char *device, Direction direction,
AbstractPort::PortStats *stats)
{
int ret;
char errbuf[PCAP_ERRBUF_SIZE] = "";
bool noLocalCapture;
direction_ = direction;
isDirectional_ = true;
isPromisc_ = true;
noLocalCapture = true;
stats_ = stats;
stop_ = false;
_retry:
#ifdef Q_OS_WIN32
int flags = 0;
if (isPromisc_)
flags |= PCAP_OPENFLAG_PROMISCUOUS;
if (noLocalCapture)
flags |= PCAP_OPENFLAG_NOCAPTURE_LOCAL;
handle_ = pcap_open(device, 64 /* FIXME */, flags,
1000 /* ms */, NULL, errbuf);
#else
handle_ = pcap_open_live(device, 64 /* FIXME */, int(isPromisc_),
1000 /* ms */, errbuf);
#endif
if (handle_ == NULL)
{
if (isPromisc_ && QString(errbuf).contains("promiscuous"))
{
qDebug("Can't set promiscuous mode, trying non-promisc %s", device);
isPromisc_ = false;
goto _retry;
}
else if (noLocalCapture && QString(errbuf).contains("loopback"))
{
qDebug("Can't set no local capture mode %s", device);
noLocalCapture = false;
goto _retry;
}
else
goto _open_error;
}
#ifdef Q_OS_WIN32
// pcap_setdirection() API is not supported in Windows.
// NOTE: WinPcap 4.1.1 and above exports a dummy API that returns -1
// but since we would like to work with previous versions of WinPcap
// also, we assume the API does not exist
ret = -1;
#else
switch (direction_)
{
case kDirectionRx:
ret = pcap_setdirection(handle_, PCAP_D_IN);
break;
case kDirectionTx:
ret = pcap_setdirection(handle_, PCAP_D_OUT);
break;
default:
ret = -1; // avoid 'may be used uninitialized' warning
Q_ASSERT(false);
}
#endif
if (ret < 0)
goto _set_direction_error;
return;
_set_direction_error:
qDebug("Error setting direction(%d) %s: %s\n", direction, device,
pcap_geterr(handle_));
isDirectional_ = false;
return;
_open_error:
qDebug("%s: Error opening port %s: %s\n", __FUNCTION__, device, errbuf);
}
PcapPort::PortMonitor::~PortMonitor()
{
if (handle_)
pcap_close(handle_);
}
void PcapPort::PortMonitor::run()
{
while (!stop_)
{
int ret;
struct pcap_pkthdr *hdr;
const uchar *data;
ret = pcap_next_ex(handle_, &hdr, &data);
switch (ret)
{
case 1:
switch (direction_)
{
case kDirectionRx:
stats_->rxPkts++;
stats_->rxBytes += hdr->len;
break;
case kDirectionTx:
if (isDirectional_)
{
stats_->txPkts++;
stats_->txBytes += hdr->len;
}
break;
default:
Q_ASSERT(false);
}
//! \todo TODO pkt/bit rates
break;
case 0:
//qDebug("%s: timeout. continuing ...", __PRETTY_FUNCTION__);
continue;
case -1:
qWarning("%s: error reading packet (%d): %s",
__PRETTY_FUNCTION__, ret, pcap_geterr(handle_));
break;
case -2:
qWarning("%s: error reading packet (%d): %s",
__PRETTY_FUNCTION__, ret, pcap_geterr(handle_));
break;
default:
qFatal("%s: Unexpected return value %d", __PRETTY_FUNCTION__, ret);
}
}
}
void PcapPort::PortMonitor::stop()
{
stop_ = true;
pcap_breakloop(handle());
}
/*
* ------------------------------------------------------------------- *
* Port Transmitter
* ------------------------------------------------------------------- *
*/
PcapPort::PortTransmitter::PortTransmitter(const char *device)
{
char errbuf[PCAP_ERRBUF_SIZE] = "";
#ifdef Q_OS_WIN32
LARGE_INTEGER freq;
if (QueryPerformanceFrequency(&freq))
gTicksFreq = freq.QuadPart;
else
Q_ASSERT_X(false, "PortTransmitter::PortTransmitter",
"This Win32 platform does not support performance counter");
#endif
state_ = kNotStarted;
returnToQIdx_ = -1;
loopDelay_ = 0;
stop_ = false;
stats_ = new AbstractPort::PortStats;
usingInternalStats_ = true;
handle_ = pcap_open_live(device, 64 /* FIXME */, 0, 1000 /* ms */, errbuf);
if (handle_ == NULL)
goto _open_error;
usingInternalHandle_ = true;
return;
_open_error:
qDebug("%s: Error opening port %s: %s\n", __FUNCTION__, device, errbuf);
usingInternalHandle_ = false;
}
PcapPort::PortTransmitter::~PortTransmitter()
{
if (usingInternalStats_)
delete stats_;
if (usingInternalHandle_)
pcap_close(handle_);
}
bool PcapPort::PortTransmitter::setRateAccuracy(
AbstractPort::Accuracy accuracy)
{
switch (accuracy) {
case kHighAccuracy:
udelayFn_ = udelay;
qWarning("%s: rate accuracy set to High - busy wait", __FUNCTION__);
break;
case kLowAccuracy:
udelayFn_ = QThread::usleep;
qWarning("%s: rate accuracy set to Low - usleep", __FUNCTION__);
break;
default:
qWarning("%s: unsupported rate accuracy value %d", __FUNCTION__,
accuracy);
return false;
}
return true;
}
void PcapPort::PortTransmitter::clearPacketList()
{
Q_ASSERT(!isRunning());
// \todo lock for packetSequenceList
while(packetSequenceList_.size())
delete packetSequenceList_.takeFirst();
currentPacketSequence_ = NULL;
repeatSequenceStart_ = -1;
repeatSize_ = 0;
packetCount_ = 0;
returnToQIdx_ = -1;
setPacketListLoopMode(false, 0, 0);
}
void PcapPort::PortTransmitter::loopNextPacketSet(qint64 size, qint64 repeats,
long repeatDelaySec, long repeatDelayNsec)
{
currentPacketSequence_ = new PacketSequence;
currentPacketSequence_->repeatCount_ = repeats;
currentPacketSequence_->usecDelay_ = repeatDelaySec * long(1e6)
+ repeatDelayNsec/1000;
repeatSequenceStart_ = packetSequenceList_.size();
repeatSize_ = size;
packetCount_ = 0;
packetSequenceList_.append(currentPacketSequence_);
}
bool PcapPort::PortTransmitter::appendToPacketList(long sec, long nsec,
const uchar *packet, int length)
{
bool op = true;
pcap_pkthdr pktHdr;
pktHdr.caplen = pktHdr.len = length;
pktHdr.ts.tv_sec = sec;
pktHdr.ts.tv_usec = nsec/1000;
if (currentPacketSequence_ == NULL ||
!currentPacketSequence_->hasFreeSpace(2*sizeof(pcap_pkthdr)+length))
{
if (currentPacketSequence_ != NULL)
{
long usecs;
usecs = (pktHdr.ts.tv_sec
- currentPacketSequence_->lastPacket_->ts.tv_sec)
* long(1e6);
usecs += (pktHdr.ts.tv_usec
- currentPacketSequence_->lastPacket_->ts.tv_usec);
currentPacketSequence_->usecDelay_ = usecs;
}
//! \todo (LOW): calculate sendqueue size
currentPacketSequence_ = new PacketSequence;
packetSequenceList_.append(currentPacketSequence_);
// Validate that the pkt will fit inside the new currentSendQueue_
Q_ASSERT(currentPacketSequence_->hasFreeSpace(
sizeof(pcap_pkthdr) + length));
}
if (currentPacketSequence_->appendPacket(&pktHdr, (u_char*) packet) < 0)
{
op = false;
}
packetCount_++;
if (repeatSize_ > 0 && packetCount_ == repeatSize_)
{
qDebug("repeatSequenceStart_=%d, repeatSize_ = %llu",
repeatSequenceStart_, repeatSize_);
// Set the packetSequence repeatSize
Q_ASSERT(repeatSequenceStart_ >= 0);
Q_ASSERT(repeatSequenceStart_ < packetSequenceList_.size());
if (currentPacketSequence_ != packetSequenceList_[repeatSequenceStart_])
{
PacketSequence *start = packetSequenceList_[repeatSequenceStart_];
currentPacketSequence_->usecDelay_ = start->usecDelay_;
start->usecDelay_ = 0;
start->repeatSize_ =
packetSequenceList_.size() - repeatSequenceStart_;
}
repeatSize_ = 0;
// End current pktSeq and trigger a new pktSeq allocation for next pkt
currentPacketSequence_ = NULL;
}
return op;
}
void PcapPort::PortTransmitter::setHandle(pcap_t *handle)
{
if (usingInternalHandle_)
pcap_close(handle_);
handle_ = handle;
usingInternalHandle_ = false;
}
void PcapPort::PortTransmitter::useExternalStats(AbstractPort::PortStats *stats)
{
if (usingInternalStats_)
delete stats_;
stats_ = stats;
usingInternalStats_ = false;
}
void PcapPort::PortTransmitter::run()
{
//! \todo (MED) Stream Mode - continuous: define before implement
// NOTE1: We can't use pcap_sendqueue_transmit() directly even on Win32
// 'coz of 2 reasons - there's no way of stopping it before all packets
// in the sendQueue are sent out and secondly, stats are available only
// when all packets have been sent - no periodic updates
//
// NOTE2: Transmit on the Rx Handle so that we can receive it back
// on the Tx Handle to do stats
//
// NOTE3: Update pcapExtra counters - port TxStats will be updated in the
// 'stats callback' function so that both Rx and Tx stats are updated
// together
const int kSyncTransmit = 1;
int i;
long overHead = 0; // overHead should be negative or zero
qDebug("packetSequenceList_.size = %d", packetSequenceList_.size());
if (packetSequenceList_.size() <= 0)
goto _exit;
for(i = 0; i < packetSequenceList_.size(); i++) {
qDebug("sendQ[%d]: rptCnt = %d, rptSz = %d, usecDelay = %ld", i,
packetSequenceList_.at(i)->repeatCount_,
packetSequenceList_.at(i)->repeatSize_,
packetSequenceList_.at(i)->usecDelay_);
qDebug("sendQ[%d]: pkts = %ld, usecDuration = %ld", i,
packetSequenceList_.at(i)->packets_,
packetSequenceList_.at(i)->usecDuration_);
}
state_ = kRunning;
i = 0;
while (i < packetSequenceList_.size())
{
_restart:
int rptSz = packetSequenceList_.at(i)->repeatSize_;
int rptCnt = packetSequenceList_.at(i)->repeatCount_;
for (int j = 0; j < rptCnt; j++)
{
for (int k = 0; k < rptSz; k++)
{
int ret;
PacketSequence *seq = packetSequenceList_.at(i+k);
#ifdef Q_OS_WIN32
TimeStamp ovrStart, ovrEnd;
if (seq->usecDuration_ <= long(1e6)) // 1s
{
getTimeStamp(&ovrStart);
ret = pcap_sendqueue_transmit(handle_,
seq->sendQueue_, kSyncTransmit);
if (ret >= 0)
{
stats_->txPkts += seq->packets_;
stats_->txBytes += seq->bytes_;
getTimeStamp(&ovrEnd);
overHead += seq->usecDuration_
- udiffTimeStamp(&ovrStart, &ovrEnd);
Q_ASSERT(overHead <= 0);
}
if (stop_)
ret = -2;
}
else
{
ret = sendQueueTransmit(handle_, seq->sendQueue_,
overHead, kSyncTransmit);
}
#else
ret = sendQueueTransmit(handle_, seq->sendQueue_,
overHead, kSyncTransmit);
#endif
if (ret >= 0)
{
long usecs = seq->usecDelay_ + overHead;
if (usecs > 0)
{
(*udelayFn_)(usecs);
overHead = 0;
}
else
overHead = usecs;
}
else
{
qDebug("error %d in sendQueueTransmit()", ret);
qDebug("overHead = %ld", overHead);
stop_ = false;
goto _exit;
}
}
}
// Move to the next Packet Set
i += rptSz;
}
if (returnToQIdx_ >= 0)
{
long usecs = loopDelay_ + overHead;
if (usecs > 0)
{
(*udelayFn_)(usecs);
overHead = 0;
}
else
overHead = usecs;
i = returnToQIdx_;
goto _restart;
}
_exit:
state_ = kFinished;
}
void PcapPort::PortTransmitter::start()
{
// FIXME: return error
if (state_ == kRunning) {
qWarning("Transmit start requested but is already running!");
return;
}
state_ = kNotStarted;
QThread::start();
while (state_ == kNotStarted)
QThread::msleep(10);
}
void PcapPort::PortTransmitter::stop()
{
if (state_ == kRunning) {
stop_ = true;
while (state_ == kRunning)
QThread::msleep(10);
}
else {
// FIXME: return error
qWarning("Transmit stop requested but is not running!");
return;
}
}
bool PcapPort::PortTransmitter::isRunning()
{
return (state_ == kRunning);
}
int PcapPort::PortTransmitter::sendQueueTransmit(pcap_t *p,
pcap_send_queue *queue, long &overHead, int sync)
{
TimeStamp ovrStart, ovrEnd;
struct timeval ts;
struct pcap_pkthdr *hdr = (struct pcap_pkthdr*) queue->buffer;
char *end = queue->buffer + queue->len;
ts = hdr->ts;
getTimeStamp(&ovrStart);
while((char*) hdr < end)
{
uchar *pkt = (uchar*)hdr + sizeof(*hdr);
int pktLen = hdr->caplen;
if (sync)
{
long usec = (hdr->ts.tv_sec - ts.tv_sec) * 1000000 +
(hdr->ts.tv_usec - ts.tv_usec);
getTimeStamp(&ovrEnd);
overHead -= udiffTimeStamp(&ovrStart, &ovrEnd);
Q_ASSERT(overHead <= 0);
usec += overHead;
if (usec > 0)
{
(*udelayFn_)(usec);
overHead = 0;
}
else
overHead = usec;
ts = hdr->ts;
getTimeStamp(&ovrStart);
}
Q_ASSERT(pktLen > 0);
pcap_sendpacket(p, pkt, pktLen);
stats_->txPkts++;
stats_->txBytes += pktLen;
// Step to the next packet in the buffer
hdr = (struct pcap_pkthdr*) (pkt + pktLen);
pkt = (uchar*) ((uchar*)hdr + sizeof(*hdr));
if (stop_)
{
return -2;
}
}
return 0;
}
void PcapPort::PortTransmitter::udelay(unsigned long usec)
{
#if defined(Q_OS_WIN32)
LARGE_INTEGER tgtTicks;
LARGE_INTEGER curTicks;
QueryPerformanceCounter(&curTicks);
tgtTicks.QuadPart = curTicks.QuadPart + (usec*gTicksFreq)/1000000;
while (curTicks.QuadPart < tgtTicks.QuadPart)
QueryPerformanceCounter(&curTicks);
#elif defined(Q_OS_LINUX)
struct timeval delay, target, now;
//qDebug("usec delay = %ld", usec);
delay.tv_sec = 0;
delay.tv_usec = usec;
while (delay.tv_usec >= 1000000)
{
delay.tv_sec++;
delay.tv_usec -= 1000000;
}
gettimeofday(&now, NULL);
timeradd(&now, &delay, &target);
do {
gettimeofday(&now, NULL);
} while (timercmp(&now, &target, <));
#else
QThread::usleep(usec);
#endif
}
/*
* ------------------------------------------------------------------- *
* Port Capturer
* ------------------------------------------------------------------- *
*/
PcapPort::PortCapturer::PortCapturer(const char *device)
{
device_ = QString::fromAscii(device);
stop_ = false;
state_ = kNotStarted;
if (!capFile_.open())
qWarning("Unable to open temp cap file");
qDebug("cap file = %s", capFile_.fileName().toAscii().constData());
dumpHandle_ = NULL;
handle_ = NULL;
}
PcapPort::PortCapturer::~PortCapturer()
{
capFile_.close();
}
void PcapPort::PortCapturer::run()
{
int flag = PCAP_OPENFLAG_PROMISCUOUS;
char errbuf[PCAP_ERRBUF_SIZE] = "";
qDebug("In %s", __PRETTY_FUNCTION__);
if (!capFile_.isOpen())
{
qWarning("temp cap file is not open");
goto _exit;
}
_retry:
handle_ = pcap_open_live(device_.toAscii().constData(), 65535,
flag, 1000 /* ms */, errbuf);
if (handle_ == NULL)
{
if (flag && QString(errbuf).contains("promiscuous"))
{
qDebug("%s:can't set promiscuous mode, trying non-promisc",
device_.toAscii().constData());
flag = 0;
goto _retry;
}
else
{
qDebug("%s: Error opening port %s: %s\n", __FUNCTION__,
device_.toAscii().constData(), errbuf);
goto _exit;
}
}
dumpHandle_ = pcap_dump_open(handle_,
capFile_.fileName().toAscii().constData());
state_ = kRunning;
while (1)
{
int ret;
struct pcap_pkthdr *hdr;
const uchar *data;
ret = pcap_next_ex(handle_, &hdr, &data);
switch (ret)
{
case 1:
pcap_dump((uchar*) dumpHandle_, hdr, data);
break;
case 0:
// timeout: just go back to the loop
break;
case -1:
qWarning("%s: error reading packet (%d): %s",
__PRETTY_FUNCTION__, ret, pcap_geterr(handle_));
break;
case -2:
default:
qFatal("%s: Unexpected return value %d", __PRETTY_FUNCTION__, ret);
}
if (stop_)
{
qDebug("user requested capture stop\n");
break;
}
}
pcap_dump_close(dumpHandle_);
pcap_close(handle_);
dumpHandle_ = NULL;
handle_ = NULL;
stop_ = false;
_exit:
state_ = kFinished;
}
void PcapPort::PortCapturer::start()
{
// FIXME: return error
if (state_ == kRunning) {
qWarning("Capture start requested but is already running!");
return;
}
state_ = kNotStarted;
QThread::start();
while (state_ == kNotStarted)
QThread::msleep(10);
}
void PcapPort::PortCapturer::stop()
{
if (state_ == kRunning) {
stop_ = true;
while (state_ == kRunning)
QThread::msleep(10);
}
else {
// FIXME: return error
qWarning("Capture stop requested but is not running!");
return;
}
}
bool PcapPort::PortCapturer::isRunning()
{
return (state_ == kRunning);
}
QFile* PcapPort::PortCapturer::captureFile()
{
return &capFile_;
}
/*
* ------------------------------------------------------------------- *
* Transmit+Receiver for Device/ProtocolEmulation
* ------------------------------------------------------------------- *
*/
PcapPort::EmulationTransceiver::EmulationTransceiver(const char *device,
DeviceManager *deviceManager)
{
device_ = QString::fromAscii(device);
deviceManager_ = deviceManager;
stop_ = false;
state_ = kNotStarted;
handle_ = NULL;
}
PcapPort::EmulationTransceiver::~EmulationTransceiver()
{
stop();
}
void PcapPort::EmulationTransceiver::run()
{
int flags = PCAP_OPENFLAG_PROMISCUOUS;
char errbuf[PCAP_ERRBUF_SIZE] = "";
struct bpf_program bpf;
#if 0
const char *capture_filter =
"arp or icmp or icmp6 or "
"(vlan and (arp or icmp or icmp6)) or "
"(vlan and vlan and (arp or icmp or icmp6)) or "
"(vlan and vlan and vlan and (arp or icmp or icmp6)) or "
"(vlan and vlan and vlan and vlan and (arp or icmp or icmp6))";
/*
Ideally we should use the above filter, but the 'vlan' capture filter
in libpcap is implemented as a kludge. From the pcap-filter man page -
vlan [vlan_id]
Note that the first vlan keyword encountered in expression changes
the decoding offsets for the remainder of expression on the
assumption that the packet is a VLAN packet.
The vlan [vlan_id] expression may be used more than once, to filter on
VLAN hierarchies. Each use of that expression increments the filter
offsets by 4.
See https://ask.wireshark.org/questions/31953/unusual-behavior-with-stacked-vlan-tags-and-capture-filter
So we use the modified filter expression that works as we intend. If ever
libpcap changes their implementation, this will need to change as well.
*/
#else
const char *capture_filter =
"arp or icmp or icmp6 or "
"(vlan and (arp or icmp or icmp6)) or "
"(vlan and (arp or icmp or icmp6)) or "
"(vlan and (arp or icmp or icmp6)) or "
"(vlan and (arp or icmp or icmp6))";
#endif
const int optimize = 1;
qDebug("In %s", __PRETTY_FUNCTION__);
#ifdef Q_OS_WIN32
flags |= PCAP_OPENFLAG_NOCAPTURE_LOCAL;
#endif
#ifdef Q_OS_WIN32
_retry:
// NOCAPTURE_LOCAL needs windows only pcap_open()
handle_ = pcap_open(qPrintable(device_), 65535,
flags, 100 /* ms */, NULL, errbuf);
#else
handle_ = pcap_open_live(qPrintable(device_), 65535,
flags, 100 /* ms */, errbuf);
#endif
if (handle_ == NULL)
{
if (flags && QString(errbuf).contains("promiscuous"))
{
notify("Unable to set promiscuous mode on <%s> - "
"device emulation will not work", qPrintable(device_));
goto _exit;
}
#ifdef Q_OS_WIN32
else if ((flags & PCAP_OPENFLAG_NOCAPTURE_LOCAL)
&& QString(errbuf).contains("loopback"))
{
qDebug("Can't set no local capture mode %s", qPrintable(device_));
flags &= ~PCAP_OPENFLAG_NOCAPTURE_LOCAL;
goto _retry;
}
#endif
else
{
notify("Unable to open <%s> [%s] - device emulation will not work",
qPrintable(device_), errbuf);
goto _exit;
}
}
// TODO: for now the filter is hardcoded to accept tagged/untagged
// ARP/NDP or ICMPv4/v6; when more protocols are added, we may need
// to derive this filter based on which protocols are configured
// on the devices
if (pcap_compile(handle_, &bpf, capture_filter, optimize, 0) < 0)
{
qWarning("%s: error compiling filter: %s", qPrintable(device_),
pcap_geterr(handle_));
goto _skip_filter;
}
if (pcap_setfilter(handle_, &bpf) < 0)
{
qWarning("%s: error setting filter: %s", qPrintable(device_),
pcap_geterr(handle_));
goto _skip_filter;
}
_skip_filter:
state_ = kRunning;
while (1)
{
int ret;
struct pcap_pkthdr *hdr;
const uchar *data;
ret = pcap_next_ex(handle_, &hdr, &data);
switch (ret)
{
case 1:
{
PacketBuffer *pktBuf = new PacketBuffer(data, hdr->caplen);
#if 0
for (int i = 0; i < 64; i++) {
printf("%02x ", data[i]);
if (i % 16 == 0)
printf("\n");
}
printf("\n");
#endif
// XXX: deviceManager should free pktBuf before returning
// from this call; if it needs to process the pkt async
// it should make a copy as the pktBuf's data buffer is
// owned by libpcap which does not guarantee data will
// persist across calls to pcap_next_ex()
deviceManager_->receivePacket(pktBuf);
break;
}
case 0:
// timeout: just go back to the loop
break;
case -1:
qWarning("%s: error reading packet (%d): %s",
__PRETTY_FUNCTION__, ret, pcap_geterr(handle_));
break;
case -2:
default:
qFatal("%s: Unexpected return value %d", __PRETTY_FUNCTION__,
ret);
}
if (stop_)
{
qDebug("user requested receiver stop\n");
break;
}
}
pcap_close(handle_);
handle_ = NULL;
stop_ = false;
_exit:
state_ = kFinished;
}
void PcapPort::EmulationTransceiver::start()
{
if (state_ == kRunning) {
qWarning("Receive start requested but is already running!");
return;
}
state_ = kNotStarted;
QThread::start();
while (state_ == kNotStarted)
QThread::msleep(10);
}
void PcapPort::EmulationTransceiver::stop()
{
if (state_ == kRunning) {
stop_ = true;
while (state_ == kRunning)
QThread::msleep(10);
}
else {
qWarning("Receive stop requested but is not running!");
return;
}
}
bool PcapPort::EmulationTransceiver::isRunning()
{
return (state_ == kRunning);
}
int PcapPort::EmulationTransceiver::transmitPacket(PacketBuffer *pktBuf)
{
return pcap_sendpacket(handle_, pktBuf->data(), pktBuf->length());
}
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