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/*
* Copyright (c) 2017, Matias Fontanini
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <tins/tcp_ip/stream_follower.h>
#ifdef TINS_HAVE_TCPIP
#include <limits>
#include <tins/ip_address.h>
#include <tins/ipv6_address.h>
#include <tins/tcp.h>
#include <tins/ip.h>
#include <tins/ipv6.h>
#include <tins/rawpdu.h>
#include <tins/packet.h>
#include <tins/exceptions.h>
using std::make_pair;
using std::bind;
using std::pair;
using std::numeric_limits;
using std::chrono::system_clock;
using std::chrono::minutes;
using std::chrono::duration_cast;
namespace Tins {
namespace TCPIP {
const size_t StreamFollower::DEFAULT_MAX_BUFFERED_CHUNKS = 512;
const size_t StreamFollower::DEFAULT_MAX_SACKED_INTERVALS = 1024;
const uint32_t StreamFollower::DEFAULT_MAX_BUFFERED_BYTES = 3 * 1024 * 1024; // 3MB
const StreamFollower::timestamp_type StreamFollower::DEFAULT_KEEP_ALIVE = minutes(5);
StreamFollower::StreamFollower()
: max_buffered_chunks_(DEFAULT_MAX_BUFFERED_CHUNKS),
max_buffered_bytes_(DEFAULT_MAX_BUFFERED_BYTES), last_cleanup_(0),
stream_keep_alive_(DEFAULT_KEEP_ALIVE), attach_to_flows_(false) {
}
void StreamFollower::process_packet(PDU& packet) {
// Use current time
const system_clock::duration ts = system_clock::now().time_since_epoch();
process_packet(packet, duration_cast<timestamp_type>(ts));
}
void StreamFollower::process_packet(Packet& packet) {
process_packet(*packet.pdu(), packet.timestamp());
}
void StreamFollower::process_packet(PDU& packet, const timestamp_type& ts) {
const TCP* tcp = packet.find_pdu<TCP>();
if (!tcp) {
return;
}
stream_id identifier = stream_id::make_identifier(packet);
streams_type::iterator iter = streams_.find(identifier);
if (iter == streams_.end()) {
// Start tracking if they're either SYNs or they contain data (attach
// to an already running flow).
// Start on client's SYN, not on server's SYN+ACK
const bool is_syn = tcp->has_flags(TCP::SYN) && !tcp->has_flags(TCP::ACK);
if (is_syn || (attach_to_flows_ && tcp->find_pdu<RawPDU>() != 0)) {
iter = streams_.insert(make_pair(identifier, Stream(packet, ts))).first;
iter->second.setup_flows_callbacks();
if (on_new_connection_) {
on_new_connection_(iter->second);
}
else {
throw callback_not_set();
}
if (!is_syn) {
// assume the connection is established
iter->second.client_flow().state(Flow::ESTABLISHED);
iter->second.server_flow().state(Flow::ESTABLISHED);
}
}
else {
// no stream found and no stream was created
if (last_cleanup_ + stream_keep_alive_ <= ts) {
cleanup_streams(ts);
}
return;
}
}
// We'll process it if we had already seen this stream or if we just attached to
// it and it contains payload
Stream& stream = iter->second;
stream.process_packet(packet, ts);
// Check for different potential termination
size_t total_chunks = stream.client_flow().buffered_payload().size() +
stream.server_flow().buffered_payload().size();
uint32_t total_buffered_bytes = stream.client_flow().total_buffered_bytes() +
stream.server_flow().total_buffered_bytes();
bool terminate_stream = total_chunks > max_buffered_chunks_ ||
total_buffered_bytes > max_buffered_bytes_;
TerminationReason reason = BUFFERED_DATA;
#ifdef TINS_HAVE_ACK_TRACKER
if (!terminate_stream) {
uint32_t count = 0;
count += stream.client_flow().ack_tracker().acked_intervals().iterative_size();
count += stream.server_flow().ack_tracker().acked_intervals().iterative_size();
terminate_stream = count > DEFAULT_MAX_SACKED_INTERVALS;
reason = SACKED_SEGMENTS;
}
#endif // TINS_HAVE_ACK_TRACKER
if (stream.is_finished() || terminate_stream) {
// If we're terminating the stream, execute the termination callback
if (terminate_stream && on_stream_termination_) {
on_stream_termination_(stream, reason);
}
streams_.erase(iter);
}
if (last_cleanup_ + stream_keep_alive_ <= ts) {
cleanup_streams(ts);
}
}
void StreamFollower::new_stream_callback(const stream_callback_type& callback) {
on_new_connection_ = callback;
}
void StreamFollower::stream_termination_callback(const stream_termination_callback_type& callback) {
on_stream_termination_ = callback;
}
Stream& StreamFollower::find_stream(const IPv4Address& client_addr, uint16_t client_port,
const IPv4Address& server_addr, uint16_t server_port) {
stream_id identifier(stream_id::serialize(client_addr), client_port,
stream_id::serialize(server_addr), server_port);
return find_stream(identifier);
}
Stream& StreamFollower::find_stream(const IPv6Address& client_addr, uint16_t client_port,
const IPv6Address& server_addr, uint16_t server_port) {
stream_id identifier(stream_id::serialize(client_addr), client_port,
stream_id::serialize(server_addr), server_port);
return find_stream(identifier);
}
Stream& StreamFollower::find_stream(const stream_id& id) {
streams_type::iterator iter = streams_.find(id);
if (iter == streams_.end()) {
throw stream_not_found();
}
else {
return iter->second;
}
}
void StreamFollower::follow_partial_streams(bool value) {
attach_to_flows_ = value;
}
void StreamFollower::cleanup_streams(const timestamp_type& now) {
streams_type::iterator iter = streams_.begin();
while (iter != streams_.end()) {
if (iter->second.last_seen() + stream_keep_alive_ <= now) {
// If we have a termination callback, execute it
if (on_stream_termination_) {
on_stream_termination_(iter->second, TIMEOUT);
}
streams_.erase(iter++);
}
else {
++iter;
}
}
last_cleanup_ = now;
}
} // TCPIP
} // Tins
#endif // TINS_HAVE_TCPIP
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