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nfqueue to hyperscan and stream match, removed proxyregex

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This commit is contained in:
Domingo Dirutigliano
2025-02-02 19:54:42 +01:00
parent 3de629ebd5
commit 2d8f19679f
54 changed files with 1134 additions and 3092 deletions
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485
backend/binsrc/classes/netfilter.cpp Normal file
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#include <linux/netfilter/nfnetlink_queue.h>
#include <libnetfilter_queue/libnetfilter_queue.h>
#include <linux/netfilter/nfnetlink_conntrack.h>
#include <tins/tins.h>
#include <tins/tcp_ip/stream_follower.h>
#include <libmnl/libmnl.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nfnetlink.h>
#include <linux/types.h>
#include <stdexcept>
#include <thread>
#include <hs.h>
#include <iostream>
using Tins::TCPIP::Stream;
using Tins::TCPIP::StreamFollower;
using namespace std;
#ifndef NETFILTER_CLASSES_HPP
#define NETFILTER_CLASSES_HPP
string inline client_endpoint(const Stream& stream) {
ostringstream output;
// Use the IPv4 or IPv6 address depending on which protocol the
// connection uses
if (stream.is_v6()) {
output << stream.client_addr_v6();
}
else {
output << stream.client_addr_v4();
}
output << ":" << stream.client_port();
return output.str();
}
// Convert the server endpoint to a readable string
string inline server_endpoint(const Stream& stream) {
ostringstream output;
if (stream.is_v6()) {
output << stream.server_addr_v6();
}
else {
output << stream.server_addr_v4();
}
output << ":" << stream.server_port();
return output.str();
}
// Concat both endpoints to get a readable stream identifier
string inline stream_identifier(const Stream& stream) {
ostringstream output;
output << client_endpoint(stream) << " - " << server_endpoint(stream);
return output.str();
}
typedef unordered_map<string, hs_stream_t*> matching_map;
struct packet_info;
struct tcp_stream_tmp {
bool matching_has_been_called = false;
bool result;
packet_info *pkt_info;
};
struct stream_ctx {
matching_map in_hs_streams;
matching_map out_hs_streams;
hs_scratch_t* in_scratch = nullptr;
hs_scratch_t* out_scratch = nullptr;
u_int16_t latest_config_ver = 0;
StreamFollower follower;
mnl_socket* nl;
tcp_stream_tmp tcp_match_util;
void clean_scratches(){
if (out_scratch != nullptr){
hs_free_scratch(out_scratch);
out_scratch = nullptr;
}
if (in_scratch != nullptr){
hs_free_scratch(in_scratch);
in_scratch = nullptr;
}
}
};
struct packet_info {
string packet;
string payload;
string stream_id;
bool is_input;
bool is_tcp;
stream_ctx* sctx;
};
typedef bool NetFilterQueueCallback(packet_info &);
Tins::PDU * find_transport_layer(Tins::PDU* pkt){
while(pkt != nullptr){
if (pkt->pdu_type() == Tins::PDU::TCP || pkt->pdu_type() == Tins::PDU::UDP) {
return pkt;
}
pkt = pkt->inner_pdu();
}
return nullptr;
}
template <NetFilterQueueCallback callback_func>
class NetfilterQueue {
public:
size_t BUF_SIZE = 0xffff + (MNL_SOCKET_BUFFER_SIZE/2);
char *buf = nullptr;
unsigned int portid;
u_int16_t queue_num;
stream_ctx sctx;
NetfilterQueue(u_int16_t queue_num): queue_num(queue_num) {
sctx.nl = mnl_socket_open(NETLINK_NETFILTER);
if (sctx.nl == nullptr) { throw runtime_error( "mnl_socket_open" );}
if (mnl_socket_bind(sctx.nl, 0, MNL_SOCKET_AUTOPID) < 0) {
mnl_socket_close(sctx.nl);
throw runtime_error( "mnl_socket_bind" );
}
portid = mnl_socket_get_portid(sctx.nl);
buf = (char*) malloc(BUF_SIZE);
if (!buf) {
mnl_socket_close(sctx.nl);
throw runtime_error( "allocate receive buffer" );
}
if (send_config_cmd(NFQNL_CFG_CMD_BIND) < 0) {
_clear();
throw runtime_error( "mnl_socket_send" );
}
//TEST if BIND was successful
if (send_config_cmd(NFQNL_CFG_CMD_NONE) < 0) { // SEND A NONE cmmand to generate an error meessage
_clear();
throw runtime_error( "mnl_socket_send" );
}
if (recv_packet() == -1) { //RECV the error message
_clear();
throw runtime_error( "mnl_socket_recvfrom" );
}
struct nlmsghdr *nlh = (struct nlmsghdr *) buf;
if (nlh->nlmsg_type != NLMSG_ERROR) {
_clear();
throw runtime_error( "unexpected packet from kernel (expected NLMSG_ERROR packet)" );
}
//nfqnl_msg_config_cmd
nlmsgerr* error_msg = (nlmsgerr *)mnl_nlmsg_get_payload(nlh);
// error code taken from the linux kernel:
// https://elixir.bootlin.com/linux/v5.18.12/source/include/linux/errno.h#L27
#define ENOTSUPP 524 /* Operation is not supported */
if (error_msg->error != -ENOTSUPP) {
_clear();
throw invalid_argument( "queueid is already busy" );
}
//END TESTING BIND
nlh = nfq_nlmsg_put(buf, NFQNL_MSG_CONFIG, queue_num);
nfq_nlmsg_cfg_put_params(nlh, NFQNL_COPY_PACKET, 0xffff);
mnl_attr_put_u32(nlh, NFQA_CFG_FLAGS, htonl(NFQA_CFG_F_GSO));
mnl_attr_put_u32(nlh, NFQA_CFG_MASK, htonl(NFQA_CFG_F_GSO));
if (mnl_socket_sendto(sctx.nl, nlh, nlh->nlmsg_len) < 0) {
_clear();
throw runtime_error( "mnl_socket_send" );
}
}
//Input data filtering
void on_client_data(Stream& stream) {
string data(stream.client_payload().begin(), stream.client_payload().end());
string stream_id = stream_identifier(stream);
this->sctx.tcp_match_util.pkt_info->is_input = true;
this->sctx.tcp_match_util.pkt_info->stream_id = stream_id;
this->sctx.tcp_match_util.matching_has_been_called = true;
bool result = callback_func(*sctx.tcp_match_util.pkt_info);
if (result){
this->clean_stream_by_id(stream_id);
stream.ignore_client_data();
stream.ignore_server_data();
}
this->sctx.tcp_match_util.result = result;
}
//Server data filtering
void on_server_data(Stream& stream) {
string data(stream.server_payload().begin(), stream.server_payload().end());
string stream_id = stream_identifier(stream);
this->sctx.tcp_match_util.pkt_info->is_input = false;
this->sctx.tcp_match_util.pkt_info->stream_id = stream_id;
this->sctx.tcp_match_util.matching_has_been_called = true;
bool result = callback_func(*sctx.tcp_match_util.pkt_info);
if (result){
this->clean_stream_by_id(stream_id);
stream.ignore_client_data();
stream.ignore_server_data();
}
this->sctx.tcp_match_util.result = result;
}
void on_new_stream(Stream& stream) {
string stream_id = stream_identifier(stream);
if (stream.is_partial_stream()) {
return;
}
cout << "[+] New connection " << stream_id << endl;
stream.auto_cleanup_payloads(true);
stream.client_data_callback(
[&](auto a){this->on_client_data(a);}
);
stream.server_data_callback(
[&](auto a){this->on_server_data(a);}
);
}
void clean_stream_by_id(string stream_id){
auto stream_search = this->sctx.in_hs_streams.find(stream_id);
hs_stream_t* stream_match;
if (stream_search != this->sctx.in_hs_streams.end()){
stream_match = stream_search->second;
if (hs_close_stream(stream_match, sctx.in_scratch, nullptr, nullptr) != HS_SUCCESS) {
cerr << "[error] [NetfilterQueue.clean_stream_by_id] Error closing the stream matcher (hs)" << endl;
throw invalid_argument("Cannot close stream match on hyperscan");
}
this->sctx.in_hs_streams.erase(stream_search);
}
stream_search = this->sctx.out_hs_streams.find(stream_id);
if (stream_search != this->sctx.out_hs_streams.end()){
stream_match = stream_search->second;
if (hs_close_stream(stream_match, sctx.out_scratch, nullptr, nullptr) != HS_SUCCESS) {
cerr << "[error] [NetfilterQueue.clean_stream_by_id] Error closing the stream matcher (hs)" << endl;
throw invalid_argument("Cannot close stream match on hyperscan");
}
this->sctx.out_hs_streams.erase(stream_search);
}
}
// A stream was terminated. The second argument is the reason why it was terminated
void on_stream_terminated(Stream& stream, StreamFollower::TerminationReason reason) {
string stream_id = stream_identifier(stream);
cout << "[+] Connection closed: " << stream_id << endl;
this->clean_stream_by_id(stream_id);
}
void run(){
/*
* ENOBUFS is signalled to userspace when packets were lost
* on kernel side. In most cases, userspace isn't interested
* in this information, so turn it off.
*/
int ret = 1;
mnl_socket_setsockopt(sctx.nl, NETLINK_NO_ENOBUFS, &ret, sizeof(int));
sctx.follower.new_stream_callback(
[&](auto a){this->on_new_stream(a);}
);
sctx.follower.stream_termination_callback(
[&](auto a, auto b){this->on_stream_terminated(a, b);}
);
for (;;) {
ret = recv_packet();
if (ret == -1) {
throw runtime_error( "mnl_socket_recvfrom" );
}
ret = mnl_cb_run(buf, ret, 0, portid, queue_cb, &sctx);
if (ret < 0){
throw runtime_error( "mnl_cb_run" );
}
}
}
~NetfilterQueue() {
send_config_cmd(NFQNL_CFG_CMD_UNBIND);
_clear();
}
private:
ssize_t send_config_cmd(nfqnl_msg_config_cmds cmd){
struct nlmsghdr *nlh = nfq_nlmsg_put(buf, NFQNL_MSG_CONFIG, queue_num);
nfq_nlmsg_cfg_put_cmd(nlh, AF_INET, cmd);
return mnl_socket_sendto(sctx.nl, nlh, nlh->nlmsg_len);
}
ssize_t recv_packet(){
return mnl_socket_recvfrom(sctx.nl, buf, BUF_SIZE);
}
void _clear(){
if (buf != nullptr) {
free(buf);
buf = nullptr;
}
mnl_socket_close(sctx.nl);
sctx.nl = nullptr;
sctx.clean_scratches();
for(auto ele: sctx.in_hs_streams){
if (hs_close_stream(ele.second, sctx.in_scratch, nullptr, nullptr) != HS_SUCCESS) {
cerr << "[error] [NetfilterQueue.clean_stream_by_id] Error closing the stream matcher (hs)" << endl;
throw invalid_argument("Cannot close stream match on hyperscan");
}
}
sctx.in_hs_streams.clear();
for(auto ele: sctx.out_hs_streams){
if (hs_close_stream(ele.second, sctx.out_scratch, nullptr, nullptr) != HS_SUCCESS) {
cerr << "[error] [NetfilterQueue.clean_stream_by_id] Error closing the stream matcher (hs)" << endl;
throw invalid_argument("Cannot close stream match on hyperscan");
}
}
sctx.out_hs_streams.clear();
}
static int queue_cb(const nlmsghdr *nlh, void *data_ptr)
{
stream_ctx* sctx = (stream_ctx*)data_ptr;
//Extract attributes from the nlmsghdr
nlattr *attr[NFQA_MAX+1] = {};
if (nfq_nlmsg_parse(nlh, attr) < 0) {
perror("problems parsing");
return MNL_CB_ERROR;
}
if (attr[NFQA_PACKET_HDR] == nullptr) {
fputs("metaheader not set\n", stderr);
return MNL_CB_ERROR;
}
//Get Payload
uint16_t plen = mnl_attr_get_payload_len(attr[NFQA_PAYLOAD]);
uint8_t *payload = (uint8_t *)mnl_attr_get_payload(attr[NFQA_PAYLOAD]);
//Return result to the kernel
struct nfqnl_msg_packet_hdr *ph = (nfqnl_msg_packet_hdr*) mnl_attr_get_payload(attr[NFQA_PACKET_HDR]);
struct nfgenmsg *nfg = (nfgenmsg *)mnl_nlmsg_get_payload(nlh);
char buf[MNL_SOCKET_BUFFER_SIZE];
struct nlmsghdr *nlh_verdict;
struct nlattr *nest;
nlh_verdict = nfq_nlmsg_put(buf, NFQNL_MSG_VERDICT, ntohs(nfg->res_id));
// Check IP protocol version
Tins::PDU *packet;
if ( ((payload)[0] & 0xf0) == 0x40 ){
Tins::IP parsed = Tins::IP(payload, plen);
packet = &parsed;
}else{
Tins::IPv6 parsed = Tins::IPv6(payload, plen);
packet = &parsed;
}
Tins::PDU *transport_layer = find_transport_layer(packet);
if(transport_layer == nullptr || transport_layer->inner_pdu() == nullptr){
nfq_nlmsg_verdict_put(nlh_verdict, ntohl(ph->packet_id), NF_ACCEPT );
}else{
bool is_tcp = transport_layer->pdu_type() == Tins::PDU::TCP;
int size = transport_layer->inner_pdu()->size();
packet_info pktinfo{
packet: string(payload, payload+plen),
payload: string(payload+plen - size, payload+plen),
stream_id: "", // TODO We need to calculate this
is_input: true, // TODO We need to detect this
is_tcp: is_tcp,
sctx: sctx,
};
if (is_tcp){
sctx->tcp_match_util.matching_has_been_called = false;
sctx->tcp_match_util.pkt_info = &pktinfo;
sctx->follower.process_packet(*packet);
if (sctx->tcp_match_util.matching_has_been_called && !sctx->tcp_match_util.result){
auto tcp_layer = (Tins::TCP *)transport_layer;
tcp_layer->release_inner_pdu();
tcp_layer->set_flag(Tins::TCP::FIN,1);
tcp_layer->set_flag(Tins::TCP::ACK,1);
tcp_layer->set_flag(Tins::TCP::SYN,0);
nfq_nlmsg_verdict_put_pkt(nlh_verdict, packet->serialize().data(), packet->size());
nfq_nlmsg_verdict_put(nlh_verdict, ntohl(ph->packet_id), NF_ACCEPT );
delete tcp_layer;
}
}else if(callback_func(pktinfo)){
nfq_nlmsg_verdict_put(nlh_verdict, ntohl(ph->packet_id), NF_ACCEPT );
} else{
nfq_nlmsg_verdict_put(nlh_verdict, ntohl(ph->packet_id), NF_DROP );
}
}
/* example to set the connmark. First, start NFQA_CT section: */
nest = mnl_attr_nest_start(nlh_verdict, NFQA_CT);
/* then, add the connmark attribute: */
mnl_attr_put_u32(nlh_verdict, CTA_MARK, htonl(42));
/* more conntrack attributes, e.g. CTA_LABELS could be set here */
/* end conntrack section */
mnl_attr_nest_end(nlh_verdict, nest);
if (mnl_socket_sendto(sctx->nl, nlh_verdict, nlh_verdict->nlmsg_len) < 0) {
throw runtime_error( "mnl_socket_send" );
}
return MNL_CB_OK;
}
};
template <NetFilterQueueCallback func>
class NFQueueSequence{
private:
vector<NetfilterQueue<func> *> nfq;
uint16_t _init;
uint16_t _end;
vector<thread> threads;
public:
static const int QUEUE_BASE_NUM = 1000;
NFQueueSequence(uint16_t seq_len){
if (seq_len <= 0) throw invalid_argument("seq_len <= 0");
nfq = vector<NetfilterQueue<func>*>(seq_len);
_init = QUEUE_BASE_NUM;
while(nfq[0] == nullptr){
if (_init+seq_len-1 >= 65536){
throw runtime_error("NFQueueSequence: too many queues!");
}
for (int i=0;i<seq_len;i++){
try{
nfq[i] = new NetfilterQueue<func>(_init+i);
}catch(const invalid_argument e){
for(int j = 0; j < i; j++) {
delete nfq[j];
nfq[j] = nullptr;
}
_init += seq_len - i;
break;
}
}
}
_end = _init + seq_len - 1;
}
void start(){
if (threads.size() != 0) throw runtime_error("NFQueueSequence: already started!");
for (int i=0;i<nfq.size();i++){
threads.push_back(thread(&NetfilterQueue<func>::run, nfq[i]));
}
}
void join(){
for (int i=0;i<nfq.size();i++){
threads[i].join();
}
threads.clear();
}
uint16_t init(){
return _init;
}
uint16_t end(){
return _end;
}
~NFQueueSequence(){
for (int i=0;i<nfq.size();i++){
delete nfq[i];
}
}
};
#endif // NETFILTER_CLASSES_HPP

294
backend/binsrc/classes/netfilter.hpp
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@@ -1,294 +0,0 @@
#include <linux/netfilter/nfnetlink_queue.h>
#include <libnetfilter_queue/libnetfilter_queue.h>
#include <linux/netfilter/nfnetlink_conntrack.h>
#include <tins/tins.h>
#include <libmnl/libmnl.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nfnetlink.h>
#include <linux/types.h>
#include <stdexcept>
#include <thread>
#ifndef NETFILTER_CLASSES_HPP
#define NETFILTER_CLASSES_HPP
typedef bool NetFilterQueueCallback(const uint8_t*,uint32_t);
Tins::PDU * find_transport_layer(Tins::PDU* pkt){
while(pkt != NULL){
if (pkt->pdu_type() == Tins::PDU::TCP || pkt->pdu_type() == Tins::PDU::UDP) {
return pkt;
}
pkt = pkt->inner_pdu();
}
return pkt;
}
template <NetFilterQueueCallback callback_func>
class NetfilterQueue {
public:
size_t BUF_SIZE = 0xffff + (MNL_SOCKET_BUFFER_SIZE/2);
char *buf = NULL;
unsigned int portid;
u_int16_t queue_num;
struct mnl_socket* nl = NULL;
NetfilterQueue(u_int16_t queue_num): queue_num(queue_num) {
nl = mnl_socket_open(NETLINK_NETFILTER);
if (nl == NULL) { throw std::runtime_error( "mnl_socket_open" );}
if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
mnl_socket_close(nl);
throw std::runtime_error( "mnl_socket_bind" );
}
portid = mnl_socket_get_portid(nl);
buf = (char*) malloc(BUF_SIZE);
if (!buf) {
mnl_socket_close(nl);
throw std::runtime_error( "allocate receive buffer" );
}
if (send_config_cmd(NFQNL_CFG_CMD_BIND) < 0) {
_clear();
throw std::runtime_error( "mnl_socket_send" );
}
//TEST if BIND was successful
if (send_config_cmd(NFQNL_CFG_CMD_NONE) < 0) { // SEND A NONE cmmand to generate an error meessage
_clear();
throw std::runtime_error( "mnl_socket_send" );
}
if (recv_packet() == -1) { //RECV the error message
_clear();
throw std::runtime_error( "mnl_socket_recvfrom" );
}
struct nlmsghdr *nlh = (struct nlmsghdr *) buf;
if (nlh->nlmsg_type != NLMSG_ERROR) {
_clear();
throw std::runtime_error( "unexpected packet from kernel (expected NLMSG_ERROR packet)" );
}
//nfqnl_msg_config_cmd
nlmsgerr* error_msg = (nlmsgerr *)mnl_nlmsg_get_payload(nlh);
// error code taken from the linux kernel:
// https://elixir.bootlin.com/linux/v5.18.12/source/include/linux/errno.h#L27
#define ENOTSUPP 524 /* Operation is not supported */
if (error_msg->error != -ENOTSUPP) {
_clear();
throw std::invalid_argument( "queueid is already busy" );
}
//END TESTING BIND
nlh = nfq_nlmsg_put(buf, NFQNL_MSG_CONFIG, queue_num);
nfq_nlmsg_cfg_put_params(nlh, NFQNL_COPY_PACKET, 0xffff);
mnl_attr_put_u32(nlh, NFQA_CFG_FLAGS, htonl(NFQA_CFG_F_GSO));
mnl_attr_put_u32(nlh, NFQA_CFG_MASK, htonl(NFQA_CFG_F_GSO));
if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
_clear();
throw std::runtime_error( "mnl_socket_send" );
}
}
void run(){
/*
* ENOBUFS is signalled to userspace when packets were lost
* on kernel side. In most cases, userspace isn't interested
* in this information, so turn it off.
*/
int ret = 1;
mnl_socket_setsockopt(nl, NETLINK_NO_ENOBUFS, &ret, sizeof(int));
for (;;) {
ret = recv_packet();
if (ret == -1) {
throw std::runtime_error( "mnl_socket_recvfrom" );
}
ret = mnl_cb_run(buf, ret, 0, portid, queue_cb, nl);
if (ret < 0){
throw std::runtime_error( "mnl_cb_run" );
}
}
}
~NetfilterQueue() {
send_config_cmd(NFQNL_CFG_CMD_UNBIND);
_clear();
}
private:
ssize_t send_config_cmd(nfqnl_msg_config_cmds cmd){
struct nlmsghdr *nlh = nfq_nlmsg_put(buf, NFQNL_MSG_CONFIG, queue_num);
nfq_nlmsg_cfg_put_cmd(nlh, AF_INET, cmd);
return mnl_socket_sendto(nl, nlh, nlh->nlmsg_len);
}
ssize_t recv_packet(){
return mnl_socket_recvfrom(nl, buf, BUF_SIZE);
}
void _clear(){
if (buf != NULL) {
free(buf);
buf = NULL;
}
mnl_socket_close(nl);
}
static int queue_cb(const struct nlmsghdr *nlh, void *data)
{
struct mnl_socket* nl = (struct mnl_socket*)data;
//Extract attributes from the nlmsghdr
struct nlattr *attr[NFQA_MAX+1] = {};
if (nfq_nlmsg_parse(nlh, attr) < 0) {
perror("problems parsing");
return MNL_CB_ERROR;
}
if (attr[NFQA_PACKET_HDR] == NULL) {
fputs("metaheader not set\n", stderr);
return MNL_CB_ERROR;
}
//Get Payload
uint16_t plen = mnl_attr_get_payload_len(attr[NFQA_PAYLOAD]);
void *payload = mnl_attr_get_payload(attr[NFQA_PAYLOAD]);
//Return result to the kernel
struct nfqnl_msg_packet_hdr *ph = (nfqnl_msg_packet_hdr*) mnl_attr_get_payload(attr[NFQA_PACKET_HDR]);
struct nfgenmsg *nfg = (nfgenmsg *)mnl_nlmsg_get_payload(nlh);
char buf[MNL_SOCKET_BUFFER_SIZE];
struct nlmsghdr *nlh_verdict;
struct nlattr *nest;
nlh_verdict = nfq_nlmsg_put(buf, NFQNL_MSG_VERDICT, ntohs(nfg->res_id));
/*
This define allow to avoid to allocate new heap memory for each packet.
The code under this comment is replicated for ipv6 and ip
Better solutions are welcome. :)
*/
#define PKT_HANDLE \
Tins::PDU *transport_layer = find_transport_layer(&packet); \
if(transport_layer->inner_pdu() == nullptr || transport_layer == nullptr){ \
nfq_nlmsg_verdict_put(nlh_verdict, ntohl(ph->packet_id), NF_ACCEPT ); \
}else{ \
int size = transport_layer->inner_pdu()->size(); \
if(callback_func((const uint8_t*)payload+plen - size, size)){ \
nfq_nlmsg_verdict_put(nlh_verdict, ntohl(ph->packet_id), NF_ACCEPT ); \
} else{ \
if (transport_layer->pdu_type() == Tins::PDU::TCP){ \
((Tins::TCP *)transport_layer)->release_inner_pdu(); \
((Tins::TCP *)transport_layer)->set_flag(Tins::TCP::FIN,1); \
((Tins::TCP *)transport_layer)->set_flag(Tins::TCP::ACK,1); \
((Tins::TCP *)transport_layer)->set_flag(Tins::TCP::SYN,0); \
nfq_nlmsg_verdict_put_pkt(nlh_verdict, packet.serialize().data(), packet.size()); \
nfq_nlmsg_verdict_put(nlh_verdict, ntohl(ph->packet_id), NF_ACCEPT ); \
}else{ \
nfq_nlmsg_verdict_put(nlh_verdict, ntohl(ph->packet_id), NF_DROP ); \
} \
} \
}
// Check IP protocol version
if ( (((uint8_t*)payload)[0] & 0xf0) == 0x40 ){
Tins::IP packet = Tins::IP((uint8_t*)payload,plen);
PKT_HANDLE
}else{
Tins::IPv6 packet = Tins::IPv6((uint8_t*)payload,plen);
PKT_HANDLE
}
/* example to set the connmark. First, start NFQA_CT section: */
nest = mnl_attr_nest_start(nlh_verdict, NFQA_CT);
/* then, add the connmark attribute: */
mnl_attr_put_u32(nlh_verdict, CTA_MARK, htonl(42));
/* more conntrack attributes, e.g. CTA_LABELS could be set here */
/* end conntrack section */
mnl_attr_nest_end(nlh_verdict, nest);
if (mnl_socket_sendto(nl, nlh_verdict, nlh_verdict->nlmsg_len) < 0) {
throw std::runtime_error( "mnl_socket_send" );
}
return MNL_CB_OK;
}
};
template <NetFilterQueueCallback func>
class NFQueueSequence{
private:
std::vector<NetfilterQueue<func> *> nfq;
uint16_t _init;
uint16_t _end;
std::vector<std::thread> threads;
public:
static const int QUEUE_BASE_NUM = 1000;
NFQueueSequence(uint16_t seq_len){
if (seq_len <= 0) throw std::invalid_argument("seq_len <= 0");
nfq = std::vector<NetfilterQueue<func>*>(seq_len);
_init = QUEUE_BASE_NUM;
while(nfq[0] == NULL){
if (_init+seq_len-1 >= 65536){
throw std::runtime_error("NFQueueSequence: too many queues!");
}
for (int i=0;i<seq_len;i++){
try{
nfq[i] = new NetfilterQueue<func>(_init+i);
}catch(const std::invalid_argument e){
for(int j = 0; j < i; j++) {
delete nfq[j];
nfq[j] = nullptr;
}
_init += seq_len - i;
break;
}
}
}
_end = _init + seq_len - 1;
}
void start(){
if (threads.size() != 0) throw std::runtime_error("NFQueueSequence: already started!");
for (int i=0;i<nfq.size();i++){
threads.push_back(std::thread(&NetfilterQueue<func>::run, nfq[i]));
}
}
void join(){
for (int i=0;i<nfq.size();i++){
threads[i].join();
}
threads.clear();
}
uint16_t init(){
return _init;
}
uint16_t end(){
return _end;
}
~NFQueueSequence(){
for (int i=0;i<nfq.size();i++){
delete nfq[i];
}
}
};
#endif // NETFILTER_CLASSES_HPP

95
backend/binsrc/classes/regex_filter.hpp
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@@ -1,95 +0,0 @@
#include <iostream>
#include <cstring>
#include <jpcre2.hpp>
#include <sstream>
#include "../utils.hpp"
#ifndef REGEX_FILTER_HPP
#define REGEX_FILTER_HPP
typedef jpcre2::select<char> jp;
typedef std::pair<std::string,jp::Regex> regex_rule_pair;
typedef std::vector<regex_rule_pair> regex_rule_vector;
struct regex_rules{
regex_rule_vector output_whitelist, input_whitelist, output_blacklist, input_blacklist;
regex_rule_vector* getByCode(char code){
switch(code){
case 'C': // Client to server Blacklist
return &input_blacklist; break;
case 'c': // Client to server Whitelist
return &input_whitelist; break;
case 'S': // Server to client Blacklist
return &output_blacklist; break;
case 's': // Server to client Whitelist
return &output_whitelist; break;
}
throw std::invalid_argument( "Expected 'C' 'c' 'S' or 's'" );
}
int add(const char* arg){
//Integrity checks
size_t arg_len = strlen(arg);
if (arg_len < 2 || arg_len%2 != 0){
std::cerr << "[warning] [regex_rules.add] invalid arg passed (" << arg << "), skipping..." << std::endl;
return -1;
}
if (arg[0] != '0' && arg[0] != '1'){
std::cerr << "[warning] [regex_rules.add] invalid is_case_sensitive (" << arg[0] << ") in '" << arg << "', must be '1' or '0', skipping..." << std::endl;
return -1;
}
if (arg[1] != 'C' && arg[1] != 'c' && arg[1] != 'S' && arg[1] != 's'){
std::cerr << "[warning] [regex_rules.add] invalid filter_type (" << arg[1] << ") in '" << arg << "', must be 'C', 'c', 'S' or 's', skipping..." << std::endl;
return -1;
}
std::string hex(arg+2), expr;
if (!unhexlify(hex, expr)){
std::cerr << "[warning] [regex_rules.add] invalid hex regex value (" << hex << "), skipping..." << std::endl;
return -1;
}
//Push regex
jp::Regex regex(expr,arg[0] == '1'?"gS":"giS");
if (regex){
std::cerr << "[info] [regex_rules.add] adding new regex filter: '" << expr << "'" << std::endl;
getByCode(arg[1])->push_back(std::make_pair(std::string(arg), regex));
} else {
std::cerr << "[warning] [regex_rules.add] compiling of '" << expr << "' regex failed, skipping..." << std::endl;
return -1;
}
return 0;
}
bool check(unsigned char* data, const size_t& bytes_transferred, const bool in_input){
std::string str_data((char *) data, bytes_transferred);
for (regex_rule_pair ele:(in_input?input_blacklist:output_blacklist)){
try{
if(ele.second.match(str_data)){
std::stringstream msg;
msg << "BLOCKED " << ele.first << "\n";
std::cout << msg.str() << std::flush;
return false;
}
} catch(...){
std::cerr << "[info] [regex_rules.check] Error while matching blacklist regex: " << ele.first << std::endl;
}
}
for (regex_rule_pair ele:(in_input?input_whitelist:output_whitelist)){
try{
std::cerr << "[debug] [regex_rules.check] regex whitelist match " << ele.second.getPattern() << std::endl;
if(!ele.second.match(str_data)){
std::stringstream msg;
msg << "BLOCKED " << ele.first << "\n";
std::cout << msg.str() << std::flush;
return false;
}
} catch(...){
std::cerr << "[info] [regex_rules.check] Error while matching whitelist regex: " << ele.first << std::endl;
}
}
return true;
}
};
#endif // REGEX_FILTER_HPP

161
backend/binsrc/classes/regex_rules.cpp Normal file
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@@ -0,0 +1,161 @@
#include <iostream>
#include <cstring>
#include <sstream>
#include "../utils.hpp"
#include <vector>
#include <hs.h>
using namespace std;
#ifndef REGEX_FILTER_HPP
#define REGEX_FILTER_HPP
enum FilterDirection{ CTOS, STOC };
struct decoded_regex {
string regex;
FilterDirection direction;
bool is_case_sensitive;
};
struct regex_ruleset {
hs_database_t* hs_db;
char** regexes;
};
decoded_regex decode_regex(string regex){
size_t arg_len = regex.size();
if (arg_len < 2 || arg_len%2 != 0){
cerr << "[warning] [decode_regex] invalid arg passed (" << regex << "), skipping..." << endl;
throw runtime_error( "Invalid expression len (too small)" );
}
if (regex[0] != '0' && regex[0] != '1'){
cerr << "[warning] [decode_regex] invalid is_case_sensitive (" << regex[0] << ") in '" << regex << "', must be '1' or '0', skipping..." << endl;
throw runtime_error( "Invalid is_case_sensitive" );
}
if (regex[1] != 'C' && regex[1] != 'S'){
cerr << "[warning] [decode_regex] invalid filter_direction (" << regex[1] << ") in '" << regex << "', must be 'C', 'S', skipping..." << endl;
throw runtime_error( "Invalid filter_direction" );
}
string hex(regex.c_str()+2), expr;
if (!unhexlify(hex, expr)){
cerr << "[warning] [decode_regex] invalid hex regex value (" << hex << "), skipping..." << endl;
throw runtime_error( "Invalid hex regex encoded value" );
}
decoded_regex ruleset{
regex: expr,
direction: regex[1] == 'C'? CTOS : STOC,
is_case_sensitive: regex[0] == '1'
};
return ruleset;
}
class RegexRules{
public:
regex_ruleset output_ruleset, input_ruleset;
private:
static inline u_int16_t glob_seq = 0;
u_int16_t version;
vector<pair<string, decoded_regex>> decoded_input_rules;
vector<pair<string, decoded_regex>> decoded_output_rules;
bool is_stream = true;
void free_dbs(){
if (output_ruleset.hs_db != nullptr){
hs_free_database(output_ruleset.hs_db);
}
if (input_ruleset.hs_db != nullptr){
hs_free_database(input_ruleset.hs_db);
}
}
void fill_ruleset(vector<pair<string, decoded_regex>> & decoded, regex_ruleset & ruleset){
size_t n_of_regex = decoded.size();
if (n_of_regex == 0){
return;
}
const char* regex_match_rules[n_of_regex];
unsigned int regex_array_ids[n_of_regex];
unsigned int regex_flags[n_of_regex];
for(int i = 0; i < n_of_regex; i++){
regex_match_rules[i] = decoded[i].second.regex.c_str();
regex_array_ids[i] = i;
regex_flags[i] = HS_FLAG_SINGLEMATCH | HS_FLAG_ALLOWEMPTY;
if (!decoded[i].second.is_case_sensitive){
regex_flags[i] |= HS_FLAG_CASELESS;
}
}
hs_database_t* rebuilt_db;
hs_compile_error_t *compile_err;
if (
hs_compile_multi(
regex_match_rules,
regex_flags,
regex_array_ids,
n_of_regex,
is_stream?HS_MODE_STREAM:HS_MODE_BLOCK,
nullptr,&rebuilt_db, &compile_err
) != HS_SUCCESS
) {
cerr << "[warning] [RegexRules.fill_ruleset] hs_db failed to compile: '" << compile_err->message << "' skipping..." << endl;
hs_free_compile_error(compile_err);
throw runtime_error( "Failed to compile hyperscan db" );
}
ruleset.hs_db = rebuilt_db;
}
public:
RegexRules(vector<string> raw_rules, bool is_stream){
this->is_stream = is_stream;
this->version = ++glob_seq; // 0 version is a invalid version (useful for some logics)
for(string ele : raw_rules){
try{
decoded_regex rule = decode_regex(ele);
if (rule.direction == FilterDirection::CTOS){
decoded_input_rules.push_back(make_pair(ele, rule));
}else{
decoded_output_rules.push_back(make_pair(ele, rule));
}
}catch(...){
throw current_exception();
}
}
fill_ruleset(decoded_input_rules, input_ruleset);
try{
fill_ruleset(decoded_output_rules, output_ruleset);
}catch(...){
free_dbs();
throw current_exception();
}
}
u_int16_t ver(){
return version;
}
RegexRules(bool is_stream){
vector<string> no_rules;
RegexRules(no_rules, is_stream);
}
bool stream_mode(){
return is_stream;
}
RegexRules(){
RegexRules(true);
}
~RegexRules(){
free_dbs();
}
};
#endif // REGEX_FILTER_HPP