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//------------------------------------------------------------------------------
// Author: Pavel Karneliuk
// Description: Capture packets from NIC by libpcap.
// Copyright (c) 2013 EPAM Systems
//------------------------------------------------------------------------------
/*
This file is part of Nfstrace.
Nfstrace 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 of the License.
Nfstrace 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 Nfstrace. If not, see <http://www.gnu.org/licenses/>.
*/
//------------------------------------------------------------------------------
#include "filtration/pcap/capture_reader.h"
#include "filtration/pcap/bpf.h"
#include "filtration/pcap/pcap_error.h"
//------------------------------------------------------------------------------
namespace NST
{
namespace filtration
{
namespace pcap
{
CaptureReader::CaptureReader(const Params& params)
: BaseReader{params.interface}
{
char errbuf[PCAP_ERRBUF_SIZE]; // storage of error description
const char* device{source.c_str()};
handle = pcap_create(device, errbuf);
if(!handle)
{
throw PcapError("pcap_create", errbuf);
}
if(int status{pcap_set_snaplen(handle, params.snaplen)})
{
throw PcapError("pcap_set_snaplen", pcap_statustostr(status));
}
if(int status{pcap_set_promisc(handle, params.promisc ? 1 : 0)})
{
throw PcapError("pcap_set_promisc", pcap_statustostr(status));
}
if(int status{pcap_set_timeout(handle, params.timeout_ms)})
{
throw PcapError("pcap_set_timeout", pcap_statustostr(status));
}
if(int status{pcap_set_buffer_size(handle, params.buffer_size)})
{
throw PcapError("pcap_set_buffer_size", pcap_statustostr(status));
}
if(int status{pcap_activate(handle)})
{
throw PcapError("pcap_activate", pcap_statustostr(status));
}
pcap_direction_t direction{PCAP_D_INOUT};
switch(params.direction)
{
using Direction = CaptureReader::Direction;
case Direction::IN:
direction = PCAP_D_IN;
break;
case Direction::OUT:
direction = PCAP_D_OUT;
break;
case Direction::INOUT:
direction = PCAP_D_INOUT;
break;
}
if(int status{pcap_setdirection(handle, direction)})
{
throw PcapError("pcap_setdirection", pcap_statustostr(status));
}
bpf_u_int32 localnet, netmask;
if(pcap_lookupnet(device, &localnet, &netmask, errbuf) < 0)
{
throw PcapError("pcap_lookupnet", errbuf);
}
BPF bpf(handle, params.filter.c_str(), netmask);
if(pcap_setfilter(handle, bpf) < 0)
{
throw PcapError("pcap_setfiltration", pcap_geterr(handle));
}
}
void CaptureReader::print_statistic(std::ostream& out) const
{
struct pcap_stat stat = {0, 0, 0};
if(pcap_stats(handle, &stat) == 0)
{
out << "Statistics from interface: " << source << '\n'
<< " packets received by filtration: " << stat.ps_recv << '\n'
<< " packets dropped by kernel : " << stat.ps_drop << '\n'
<< " packets dropped by interface : " << stat.ps_ifdrop;
}
else
{
throw PcapError("pcap_stats", pcap_geterr(handle));
}
}
std::ostream& operator<<(std::ostream& out, const CaptureReader::Params& params)
{
out << "Read from interface: " << params.interface << '\n'
<< " BPF filter : " << params.filter << '\n'
<< " snapshot len: " << params.snaplen << " bytes\n"
<< " read timeout: " << params.timeout_ms << " ms\n"
<< " buffer size : " << params.buffer_size << " bytes\n"
<< " promiscuous mode: " << (params.promisc ? "on" : "off") << '\n'
<< " capture traffic : ";
switch(params.direction)
{
using Direction = CaptureReader::Direction;
case Direction::IN:
out << "in";
break;
case Direction::OUT:
out << "out";
break;
case Direction::INOUT:
out << "inout";
break;
}
return out;
}
} // namespace pcap
} // namespace filtration
} // namespace NST
//------------------------------------------------------------------------------
|
