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Python integration with c++ binary (not totally working yet)

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This commit is contained in:
DomySh
2022-07-18 18:52:14 +02:00
parent 02fe8f0064
commit 2a5be65feb
12 changed files with 594 additions and 866 deletions
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2
backend/app.py
View File

@@ -48,7 +48,7 @@ async def updater(): pass
@app.on_event("startup")
async def startup_event():
db.init()
await firewall.init(refresh_frontend)
await firewall.init()
await refresh_frontend()
if not JWT_SECRET(): db.put("secret", secrets.token_hex(32))

205
backend/modules/firegex.py
View File

@@ -1,12 +1,11 @@
from typing import List
from pypacker import interceptor
from pypacker.layer3 import ip, ip6
from pypacker.layer4 import tcp, udp
from typing import Dict, List, Set
from ipaddress import ip_interface
from modules.iptables import IPTables
import os, traceback
from modules.sqlite import Service
import re, os, asyncio
import traceback
from modules.sqlite import Regex
class FilterTypes:
INPUT = "FIREGEX-INPUT"
@@ -15,14 +14,13 @@ class FilterTypes:
QUEUE_BASE_NUM = 1000
class FiregexFilter():
def __init__(self, proto:str, port:int, ip_int:str, queue=None, target=None, id=None, func=None):
def __init__(self, proto:str, port:int, ip_int:str, queue=None, target=None, id=None):
self.target = target
self.id = int(id) if id else None
self.queue = queue
self.proto = proto
self.port = int(port)
self.ip_int = str(ip_int)
self.func = func
def __eq__(self, o: object) -> bool:
if isinstance(o, FiregexFilter):
@@ -35,16 +33,6 @@ class FiregexFilter():
def ipv4(self):
return ip_interface(self.ip_int).version == 4
def input_func(self):
def none(pkt): return True
def wrap(pkt): return self.func(pkt, True)
return wrap if self.func else none
def output_func(self):
def none(pkt): return True
def wrap(pkt): return self.func(pkt, False)
return wrap if self.func else none
class FiregexTables(IPTables):
def __init__(self, ipv6=False):
@@ -108,9 +96,9 @@ class FiregexTables(IPTables):
))
return res
def add(self, filter:FiregexFilter):
async def add(self, filter:FiregexFilter):
if filter in self.get(): return None
return FiregexInterceptor( iptables=self, filter=filter, n_threads=int(os.getenv("N_THREADS_NFQUEUE","1")))
return await FiregexInterceptor.start( iptables=self, filter=filter, n_queues=int(os.getenv("N_THREADS_NFQUEUE","1")))
def delete_all(self):
for filter_type in [FilterTypes.INPUT, FilterTypes.OUTPUT]:
@@ -120,52 +108,143 @@ class FiregexTables(IPTables):
for filter in self.get():
if filter.port == srv.port and filter.proto == srv.proto and ip_interface(filter.ip_int) == ip_interface(srv.ip_int):
self.delete_rule(filter.target, filter.id)
class RegexFilter:
def __init__(
self, regex,
is_case_sensitive=True,
is_blacklist=True,
input_mode=False,
output_mode=False,
blocked_packets=0,
id=None,
update_func = None
):
self.regex = regex
self.is_case_sensitive = is_case_sensitive
self.is_blacklist = is_blacklist
if input_mode == output_mode: input_mode = output_mode = True # (False, False) == (True, True)
self.input_mode = input_mode
self.output_mode = output_mode
self.blocked = blocked_packets
self.id = id
self.update_func = update_func
self.compiled_regex = self.compile()
@classmethod
def from_regex(cls, regex:Regex, update_func = None):
return cls(
id=regex.id, regex=regex.regex, is_case_sensitive=regex.is_case_sensitive,
is_blacklist=regex.is_blacklist, blocked_packets=regex.blocked_packets,
input_mode = regex.mode in ["C","B"], output_mode=regex.mode in ["S","B"],
update_func = update_func
)
def compile(self):
if isinstance(self.regex, str): self.regex = self.regex.encode()
if not isinstance(self.regex, bytes): raise Exception("Invalid Regex Paramether")
re.compile(self.regex) # raise re.error if it's invalid!
case_sensitive = "1" if self.is_case_sensitive else "0"
if self.input_mode:
yield case_sensitive + "C" + self.regex.hex() if self.is_blacklist else case_sensitive + "c"+ self.regex.hex()
if self.output_mode:
yield case_sensitive + "S" + self.regex.hex() if self.is_blacklist else case_sensitive + "s"+ self.regex.hex()
async def update(self):
if self.update_func:
if asyncio.iscoroutinefunction(self.update_func): await self.update_func(self)
else: self.update_func(self)
class FiregexInterceptor:
def __init__(self, iptables: FiregexTables, filter: FiregexFilter, n_threads:int = 1):
def __init__(self):
self.filter:FiregexFilter
self.ipv6:bool
self.filter_map_lock:asyncio.Lock
self.filter_map: Dict[str, RegexFilter]
self.regex_filters: Set[RegexFilter]
self.update_config_lock:asyncio.Lock
self.process:asyncio.subprocess.Process
self.n_queues:int
self.update_task: asyncio.Task
self.iptables:FiregexTables
@classmethod
async def start(cls, iptables: FiregexTables, filter: FiregexFilter, n_queues:int = 1):
self = cls()
self.filter = filter
self.n_queues = n_queues
self.iptables = iptables
self.ipv6 = self.filter.ipv6()
self.itor_input, codes = self._start_queue(filter.input_func(), n_threads)
iptables.add_input(queue_range=codes, proto=self.filter.proto, port=self.filter.port, ip_int=self.filter.ip_int)
self.itor_output, codes = self._start_queue(filter.output_func(), n_threads)
iptables.add_output(queue_range=codes, proto=self.filter.proto, port=self.filter.port, ip_int=self.filter.ip_int)
self.filter_map_lock = asyncio.Lock()
self.update_config_lock = asyncio.Lock()
input_range, output_range = await self._start_binary()
self.update_task = asyncio.create_task(self.update_blocked())
self.iptables.add_input(queue_range=input_range, proto=self.filter.proto, port=self.filter.port, ip_int=self.filter.ip_int)
self.iptables.add_output(queue_range=output_range, proto=self.filter.proto, port=self.filter.port, ip_int=self.filter.ip_int)
return self
async def _start_binary(self):
proxy_binary_path = os.path.join(os.path.dirname(os.path.abspath(__file__)),"./cppqueue")
self.process = await asyncio.create_subprocess_exec(
proxy_binary_path, str(self.n_queues),
stdout=asyncio.subprocess.PIPE, stdin=asyncio.subprocess.PIPE
)
line_fut = self.process.stdout.readuntil()
try:
line_fut = await asyncio.wait_for(line_fut, timeout=1)
except asyncio.TimeoutError:
self.process.kill()
raise Exception("Invalid binary output")
line = line_fut.decode()
if line.startswith("QUEUES "):
params = line.split()
return (int(params[2]), int(params[3])), (int(params[5]), int(params[6]))
else:
self.process.kill()
raise Exception("Invalid binary output")
def _start_queue(self,func,n_threads):
def func_wrap(ll_data, ll_proto_id, data, ctx, *args):
pkt_parsed = ip6.IP6(data) if self.ipv6 else ip.IP(data)
try:
pkt_data = None
if not pkt_parsed[tcp.TCP] is None:
pkt_data = pkt_parsed[tcp.TCP].body_bytes
elif not pkt_parsed[udp.UDP] is None:
pkt_data = pkt_parsed[udp.UDP].body_bytes
if pkt_data:
if func(pkt_data):
return data, interceptor.NF_ACCEPT
elif pkt_parsed[tcp.TCP]:
pkt_parsed[tcp.TCP].flags &= 0x00
pkt_parsed[tcp.TCP].flags |= tcp.TH_FIN | tcp.TH_ACK
pkt_parsed[tcp.TCP].body_bytes = b""
return pkt_parsed.bin(), interceptor.NF_ACCEPT
else: return b"", interceptor.NF_DROP
else: return data, interceptor.NF_ACCEPT
except Exception:
traceback.print_exc()
return data, interceptor.NF_ACCEPT
ictor = interceptor.Interceptor()
starts = QUEUE_BASE_NUM
while True:
if starts >= 65536:
raise Exception("Netfilter queue is full!")
queue_ids = list(range(starts,starts+n_threads))
try:
ictor.start(func_wrap, queue_ids=queue_ids)
break
except interceptor.UnableToBindException as e:
starts = e.queue_id + 1
return ictor, (starts, starts+n_threads-1)
async def update_blocked(self):
try:
while True:
line = (await self.process.stdout.readuntil()).decode()
if line.startswith("BLOCKED"):
regex_id = line.split()[1]
async with self.filter_map_lock:
if regex_id in self.filter_map:
self.filter_map[regex_id].blocked+=1
await self.filter_map[regex_id].update()
except asyncio.CancelledError: pass
except asyncio.IncompleteReadError: pass
except Exception:
traceback.print_exc()
def stop(self):
self.itor_input.stop()
self.itor_output.stop()
async def stop(self):
self.update_task.cancel()
self.process.kill()
async def _update_config(self, filters_codes):
async with self.update_config_lock:
self.process.stdin.write((" ".join(filters_codes)+"\n").encode())
await self.process.stdin.drain()
async def reload(self, filters:List[RegexFilter]):
async with self.filter_map_lock:
self.filter_map = self.compile_filters(filters)
filters_codes = self.get_filter_codes()
await self._update_config(filters_codes)
def get_filter_codes(self):
filters_codes = list(self.filter_map.keys())
filters_codes.sort(key=lambda a: self.filter_map[a].blocked, reverse=True)
return filters_codes
def compile_filters(self, filters:List[RegexFilter]):
res = {}
for filter_obj in filters:
try:
raw_filters = filter_obj.compile()
for filter in raw_filters:
res[filter] = filter_obj
except Exception: pass
return res

97
backend/modules/firewall.py
View File

@@ -1,6 +1,6 @@
import traceback, asyncio, pcre
import traceback, asyncio
from typing import Dict
from modules.firegex import FiregexFilter, FiregexTables
from modules.firegex import FiregexFilter, FiregexTables, RegexFilter
from modules.sqlite import Regex, SQLite, Service
class STATUS:
@@ -12,17 +12,8 @@ class FirewallManager:
self.db = db
self.proxy_table: Dict[str, ServiceManager] = {}
self.lock = asyncio.Lock()
self.updater_task = None
def init_updater(self, callback = None):
if not self.updater_task:
self.updater_task = asyncio.create_task(self._stats_updater(callback))
def close_updater(self):
if self.updater_task: self.updater_task.cancel()
async def close(self):
self.close_updater()
if self.updater_task: self.updater_task.cancel()
for key in list(self.proxy_table.keys()):
await self.remove(key)
@@ -33,8 +24,7 @@ class FirewallManager:
await self.proxy_table[srv_id].next(STATUS.STOP)
del self.proxy_table[srv_id]
async def init(self, callback = None):
self.init_updater(callback)
async def init(self):
await self.reload()
async def reload(self):
@@ -43,7 +33,6 @@ class FirewallManager:
srv = Service.from_dict(srv)
if srv.id in self.proxy_table:
continue
self.proxy_table[srv.id] = ServiceManager(srv, self.db)
await self.proxy_table[srv.id].next(srv.status)
@@ -71,42 +60,6 @@ class FirewallManager:
class ServiceNotFoundException(Exception): pass
class RegexFilter:
def __init__(
self, regex,
is_case_sensitive=True,
is_blacklist=True,
input_mode=False,
output_mode=False,
blocked_packets=0,
id=None
):
self.regex = regex
self.is_case_sensitive = is_case_sensitive
self.is_blacklist = is_blacklist
if input_mode == output_mode: input_mode = output_mode = True # (False, False) == (True, True)
self.input_mode = input_mode
self.output_mode = output_mode
self.blocked = blocked_packets
self.id = id
self.compiled_regex = self.compile()
@classmethod
def from_regex(cls, regex:Regex):
return cls(
id=regex.id, regex=regex.regex, is_case_sensitive=regex.is_case_sensitive,
is_blacklist=regex.is_blacklist, blocked_packets=regex.blocked_packets,
input_mode = regex.mode in ["C","B"], output_mode=regex.mode in ["S","B"]
)
def compile(self):
if isinstance(self.regex, str): self.regex = self.regex.encode()
if not isinstance(self.regex, bytes): raise Exception("Invalid Regex Paramether")
return pcre.compile(self.regex if self.is_case_sensitive else b"(?i)"+self.regex)
def check(self, data):
return True if self.compiled_regex.search(data) else False
class ServiceManager:
def __init__(self, srv: Service, db):
self.srv = srv
@@ -114,12 +67,10 @@ class ServiceManager:
self.firegextable = FiregexTables(self.srv.ipv6)
self.status = STATUS.STOP
self.filters: Dict[int, FiregexFilter] = {}
self._update_filters_from_db()
self.lock = asyncio.Lock()
self.interceptor = None
# TODO I don't like so much this method
def _update_filters_from_db(self):
async def _update_filters_from_db(self):
regexes = [
Regex.from_dict(ele) for ele in
self.db.query("SELECT * FROM regexes WHERE service_id = ? AND active=1;", self.srv.id)
@@ -127,17 +78,16 @@ class ServiceManager:
#Filter check
old_filters = set(self.filters.keys())
new_filters = set([f.id for f in regexes])
#remove old filters
for f in old_filters:
if not f in new_filters:
del self.filters[f]
#add new filters
for f in new_filters:
if not f in old_filters:
filter = [ele for ele in regexes if ele.id == f][0]
self.filters[f] = RegexFilter.from_regex(filter)
self.filters[f] = RegexFilter.from_regex(filter, self._stats_updater)
if self.interceptor: await self.interceptor.reload(self.filters.values())
def __update_status_db(self, status):
self.db.query("UPDATE services SET status = ? WHERE service_id = ?;", status, self.srv.id)
@@ -145,49 +95,36 @@ class ServiceManager:
async def next(self,to):
async with self.lock:
if (self.status, to) == (STATUS.ACTIVE, STATUS.STOP):
self.stop()
await self.stop()
self._set_status(to)
# PAUSE -> ACTIVE
elif (self.status, to) == (STATUS.STOP, STATUS.ACTIVE):
self.restart()
await self.restart()
def _stats_updater(self,filter:RegexFilter):
self.db.query("UPDATE regexes SET blocked_packets = ? WHERE regex_id = ?;", filter.blocked, filter.id)
def update_stats(self):
for ele in self.filters.values():
self._stats_updater(ele)
def _set_status(self,status):
self.status = status
self.__update_status_db(status)
def start(self):
async def start(self):
if not self.interceptor:
self.firegextable.delete_by_srv(self.srv)
def regex_filter(pkt, by_client):
try:
for filter in self.filters.values():
if (by_client and filter.input_mode) or (not by_client and filter.output_mode):
match = filter.check(pkt)
if (filter.is_blacklist and match) or (not filter.is_blacklist and not match):
filter.blocked+=1
return False
except IndexError: pass
return True
self.interceptor = self.firegextable.add(FiregexFilter(self.srv.proto,self.srv.port, self.srv.ip_int, func=regex_filter))
self.interceptor = await self.firegextable.add(FiregexFilter(self.srv.proto,self.srv.port, self.srv.ip_int))
await self._update_filters_from_db()
self._set_status(STATUS.ACTIVE)
def stop(self):
async def stop(self):
self.firegextable.delete_by_srv(self.srv)
if self.interceptor:
self.interceptor.stop()
await self.interceptor.stop()
self.interceptor = None
def restart(self):
self.stop()
self.start()
async def restart(self):
await self.stop()
await self.start()
async def update_filters(self):
async with self.lock:
self._update_filters_from_db()
await self._update_filters_from_db()

294
backend/nfqueue/classes/netfilter.hpp Normal file
View File

@@ -0,0 +1,294 @@
#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/nfqueue/classes/regex_filter.hpp Normal file
View File

@@ -0,0 +1,95 @@
#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

10
backend/nfqueue/go.mod
View File

@@ -1,10 +0,0 @@
module main
go 1.18
require github.com/DomySh/go-netfilter-queue v0.0.0-20220713124014-7261f0df2c15
require (
github.com/Jemmic/go-pcre2 v0.0.0-20190111114109-bd52ad5f7098 // indirect
github.com/google/gopacket v1.1.19 // indirect
)

18
backend/nfqueue/go.sum
View File

@@ -1,18 +0,0 @@
github.com/DomySh/go-netfilter-queue v0.0.0-20220713124014-7261f0df2c15 h1:6v9D8bG3oR0dJFMuEeEAg8Xwn436Ziv+P7QWS04wAG8=
github.com/DomySh/go-netfilter-queue v0.0.0-20220713124014-7261f0df2c15/go.mod h1:VdJ6kqHln0XlrhuxQM6eBjRIHCzvAMgcZDAtyD/GU5s=
github.com/Jemmic/go-pcre2 v0.0.0-20190111114109-bd52ad5f7098 h1:ZwFIi+5jGJWVrB2V4NvrEhIUy6uDkfnTtBsgj3HAImI=
github.com/Jemmic/go-pcre2 v0.0.0-20190111114109-bd52ad5f7098/go.mod h1:c+8WT1L7lfohb4xMaa3yAV7nlYNepqc2ZV09/CU8R/U=
github.com/google/gopacket v1.1.19 h1:ves8RnFZPGiFnTS0uPQStjwru6uO6h+nlr9j6fL7kF8=
github.com/google/gopacket v1.1.19/go.mod h1:iJ8V8n6KS+z2U1A8pUwu8bW5SyEMkXJB8Yo/Vo+TKTo=
golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
golang.org/x/lint v0.0.0-20200302205851-738671d3881b/go.mod h1:3xt1FjdF8hUf6vQPIChWIBhFzV8gjjsPE/fR3IyQdNY=
golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee/go.mod h1:QqPTAvyqsEbceGzBzNggFXnrqF1CaUcvgkdR5Ot7KZg=
golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
golang.org/x/tools v0.0.0-20200130002326-2f3ba24bd6e7/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28=
golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

264
backend/nfqueue/main.go
View File

@@ -1,264 +0,0 @@
package main
import (
"bufio"
"encoding/hex"
"fmt"
"log"
"os"
"os/user"
"strconv"
"strings"
"github.com/DomySh/go-netfilter-queue"
"github.com/Jemmic/go-pcre2"
"github.com/google/gopacket"
"github.com/google/gopacket/layers"
)
const QUEUE_BASE_NUM = 1000
const MAX_PACKET_IN_QUEUE = 100
type regex_pair struct {
regex string
matcher *pcre2.Matcher
}
type regex_filters struct {
input_whitelist []regex_pair
input_blacklist []regex_pair
output_whitelist []regex_pair
output_blacklist []regex_pair
regexes []*pcre2.Regexp
}
func NewRegexFilter() *regex_filters {
res := new(regex_filters)
res.input_blacklist = make([]regex_pair, 0)
res.input_whitelist = make([]regex_pair, 0)
res.output_blacklist = make([]regex_pair, 0)
res.output_whitelist = make([]regex_pair, 0)
res.regexes = make([]*pcre2.Regexp, 0)
return res
}
func (self *regex_filters) add(raw_regex string) {
filter_type := strings.ToLower(raw_regex[0:2])
decoded_regex, err := hex.DecodeString(raw_regex[2:])
if err != nil {
log.Printf("[add] Unable to decode regex '%s': %s", raw_regex, err)
return
}
regex, err := pcre2.Compile(string(decoded_regex), 0)
if err != nil {
log.Printf("[add] Unable to compile regex '%s': %s", string(decoded_regex), err)
return
}
self.regexes = append(self.regexes, regex)
if filter_type[0] == 'i' {
if filter_type[1] == '1' {
self.input_whitelist = append(self.input_whitelist, regex_pair{raw_regex, regex.NewMatcher()})
} else {
self.input_blacklist = append(self.input_blacklist, regex_pair{raw_regex, regex.NewMatcher()})
}
} else {
if filter_type[1] == '1' {
self.output_whitelist = append(self.output_whitelist, regex_pair{raw_regex, regex.NewMatcher()})
} else {
self.output_blacklist = append(self.output_blacklist, regex_pair{raw_regex, regex.NewMatcher()})
}
}
}
func (self *regex_filters) check(data []byte, is_input bool) bool {
if is_input {
for _, rgx := range self.input_blacklist {
if rgx.matcher.Match(data, 0) {
fmt.Printf("BLOCKED %s\n", rgx.regex)
return false
}
}
for _, rgx := range self.input_whitelist {
if !rgx.matcher.Match(data, 0) {
fmt.Printf("BLOCKED %s\n", rgx.regex)
return false
}
}
} else {
for _, rgx := range self.output_blacklist {
if rgx.matcher.Match(data, 0) {
fmt.Printf("BLOCKED %s\n", rgx.regex)
return false
}
}
for _, rgx := range self.output_whitelist {
if !rgx.matcher.Match(data, 0) {
fmt.Printf("BLOCKED %s\n", rgx.regex)
return false
}
}
}
return true
}
func (self *regex_filters) clear() {
for _, rgx := range self.input_whitelist {
rgx.matcher.Free()
}
for _, rgx := range self.input_blacklist {
rgx.matcher.Free()
}
for _, rgx := range self.output_whitelist {
rgx.matcher.Free()
}
for _, rgx := range self.output_blacklist {
rgx.matcher.Free()
}
for _, regex := range self.regexes {
regex.Free()
}
}
func handle_packets(packets <-chan netfilter.NFPacket, filter_table_channel chan regex_filters, is_input bool) {
filter_table := regex_filters{}
for true {
filter := filter_table
select {
case ft := <-filter_table_channel:
{
filter_table = ft
}
case p := <-packets:
{
p.SetVerdict(netfilter.NF_ACCEPT)
break
transport_layer := p.Packet.TransportLayer()
data := transport_layer.LayerPayload()
if len(data) > 0 {
if filter.check(data, is_input) {
p.SetVerdict(netfilter.NF_ACCEPT)
} else {
if transport_layer.LayerType() == layers.LayerTypeTCP {
*p.Packet.ApplicationLayer().(*gopacket.Payload) = []byte{}
transport_layer.(*layers.TCP).Payload = []byte{}
transport_layer.(*layers.TCP).FIN = true
transport_layer.(*layers.TCP).SYN = false
transport_layer.(*layers.TCP).RST = false
transport_layer.(*layers.TCP).ACK = true
transport_layer.(*layers.TCP).SetNetworkLayerForChecksum(p.Packet.NetworkLayer())
buffer := gopacket.NewSerializeBuffer()
options := gopacket.SerializeOptions{FixLengths: true, ComputeChecksums: true}
if err := gopacket.SerializePacket(buffer, options, p.Packet); err != nil {
p.SetVerdict(netfilter.NF_DROP)
}
p.SetVerdictWithPacket(netfilter.NF_ACCEPT, buffer.Bytes())
} else {
p.SetVerdict(netfilter.NF_DROP)
}
}
} else {
p.SetVerdict(netfilter.NF_ACCEPT)
}
}
}
}
}
func isRoot() bool {
currentUser, err := user.Current()
if err != nil {
log.Fatalf("[isRoot] Unable to get current user: %s", err)
}
return currentUser.Username == "root"
}
func create_queue_seq(num int) ([]*netfilter.NFQueue, int, int) {
var queue_list = make([]*netfilter.NFQueue, num)
var err error
starts := QUEUE_BASE_NUM
for queue_list[0] == nil {
if starts+num-1 >= 65536 {
log.Fatalf("Netfilter queue is full!")
}
for i := 0; i < len(queue_list); i++ {
queue_list[i], err = netfilter.NewNFQueue(uint16(starts+num-1-i), MAX_PACKET_IN_QUEUE, netfilter.NF_DEFAULT_PACKET_SIZE)
if err != nil {
for j := 0; j < i; j++ {
queue_list[j].Close()
queue_list[j] = nil
}
starts = starts + num - i
break
}
}
}
return queue_list, starts, starts + num - 1
}
func main() {
log.SetOutput(os.Stderr)
if !isRoot() {
log.Fatalf("[main] You must be root to run this program")
}
number_of_queues := 1
if len(os.Args) >= 2 {
var err error
number_of_queues, err = strconv.Atoi(os.Args[1])
if err != nil {
log.Fatalf("[main] Invalid number of queues: %s", err)
}
}
var filter_channels []chan regex_filters
// Start the queue list
queue_list, starts_input, end_input := create_queue_seq(number_of_queues)
for _, queue := range queue_list {
defer queue.Close()
ch := make(chan regex_filters)
filter_channels = append(filter_channels, ch)
go handle_packets(queue.GetPackets(), ch, true)
}
queue_list, starts_output, end_output := create_queue_seq(number_of_queues)
for _, queue := range queue_list {
defer queue.Close()
ch := make(chan regex_filters)
filter_channels = append(filter_channels, ch)
go handle_packets(queue.GetPackets(), ch, false)
}
fmt.Println("QUEUE INPUT", starts_input, end_input, "OUTPUT", starts_output, end_output)
//Reading for new configuration
reader := bufio.NewReader(os.Stdin)
old_filter_table := NewRegexFilter()
for true {
text, err := reader.ReadString('\n')
log.Printf("[main] Regex rule updating...")
if err != nil {
log.Fatalf("[main] Unable to read from stdin: %s", err)
}
text = strings.Trim(text, "\n")
regexes := strings.Split(text, " ")
new_filters := NewRegexFilter()
for _, regex := range regexes {
regex = strings.Trim(regex, " ")
if len(regex) < 2 {
continue
}
new_filters.add(regex)
}
for _, ch := range filter_channels {
ch <- *new_filters
}
old_filter_table.clear()
old_filter_table = new_filters
log.Printf("[main] Regex filter rules updated!")
}
}

437
backend/nfqueue/nfqueue.cpp
View File

@@ -1,421 +1,22 @@
#include <arpa/inet.h>
#include <type_traits>
#include <tins/tins.h>
#include <libmnl/libmnl.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nfnetlink.h>
#include <linux/types.h>
#include <linux/netfilter/nfnetlink_queue.h>
#include <libnetfilter_queue/libnetfilter_queue.h>
#include <linux/netfilter/nfnetlink_conntrack.h>
#include <stdexcept>
#include "classes/regex_filter.hpp"
#include "classes/netfilter.hpp"
#include "utils.hpp"
#include <iostream>
#include <cstring>
#include <cstdlib>
#include <cerrno>
#include <sstream>
#include <thread>
#include <mutex>
#include <jpcre2.hpp>
using namespace std;
using namespace Tins;
typedef jpcre2::select<char> jp;
mutex stdout_mutex;
bool unhexlify(string const &hex, string &newString) {
try{
int len = hex.length();
for(int i=0; i< len; i+=2)
{
std::string byte = hex.substr(i,2);
char chr = (char) (int)strtol(byte.c_str(), NULL, 16);
newString.push_back(chr);
}
return true;
}
catch (...){
return false;
}
}
typedef pair<string,jp::Regex> regex_rule_pair;
typedef 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 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){
cerr << "[warning] [regex_rules.add] invalid arg passed (" << arg << "), skipping..." << endl;
return -1;
}
if (arg[0] != '0' && arg[0] != '1'){
cerr << "[warning] [regex_rules.add] invalid is_case_sensitive (" << arg[0] << ") in '" << arg << "', must be '1' or '0', skipping..." << endl;
return -1;
}
if (arg[1] != 'C' && arg[1] != 'c' && arg[1] != 'S' && arg[1] != 's'){
cerr << "[warning] [regex_rules.add] invalid filter_type (" << arg[1] << ") in '" << arg << "', must be 'C', 'c', 'S' or 's', skipping..." << endl;
return -1;
}
string hex(arg+2), expr;
if (!unhexlify(hex, expr)){
cerr << "[warning] [regex_rules.add] invalid hex regex value (" << hex << "), skipping..." << endl;
return -1;
}
//Push regex
jp::Regex regex(expr,arg[0] == '1'?"gS":"giS");
if (regex){
cerr << "[info] [regex_rules.add] adding new regex filter: '" << expr << "'" << endl;
getByCode(arg[1])->push_back(make_pair(string(arg), regex));
} else {
cerr << "[warning] [regex_rules.add] compiling of '" << expr << "' regex failed, skipping..." << endl;
return -1;
}
return 0;
}
bool check(unsigned char* data, const size_t& bytes_transferred, const bool in_input){
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)){
unique_lock<mutex> lck(stdout_mutex);
cout << "BLOCKED " << ele.first << endl;
return false;
}
} catch(...){
cerr << "[info] [regex_rules.check] Error while matching blacklist regex: " << ele.first << endl;
}
}
for (regex_rule_pair ele:(in_input?input_whitelist:output_whitelist)){
try{
cerr << "[debug] [regex_rules.check] regex whitelist match " << ele.second.getPattern() << endl;
if(!ele.second.match(str_data)){
unique_lock<mutex> lck(stdout_mutex);
cout << "BLOCKED " << ele.first << endl;
return false;
}
} catch(...){
cerr << "[info] [regex_rules.check] Error while matching whitelist regex: " << ele.first << endl;
}
}
return true;
}
};
shared_ptr<regex_rules> regex_config;
typedef bool NetFilterQueueCallback(const uint8_t*,uint32_t);
PDU * find_transport_layer(PDU* pkt){
while(pkt != NULL){
if (pkt->pdu_type() == PDU::TCP || pkt->pdu_type() == 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 runtime_error( "mnl_socket_open" );}
if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
mnl_socket_close(nl);
throw runtime_error( "mnl_socket_bind" );
}
portid = mnl_socket_get_portid(nl);
buf = (char*) malloc(BUF_SIZE);
if (!buf) {
mnl_socket_close(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 std::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 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 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 \
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() == PDU::TCP){ \
((TCP *)transport_layer)->release_inner_pdu(); \
((TCP *)transport_layer)->set_flag(TCP::FIN,1); \
((TCP *)transport_layer)->set_flag(TCP::ACK,1); \
((TCP *)transport_layer)->set_flag(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 ){
IP packet = IP((uint8_t*)payload,plen);
PKT_HANDLE
}else{
IPv6 packet = 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:
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] == NULL){
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];
}
}
};
bool is_sudo(){
return getuid() == 0;
}
void config_updater (){
string line, data;
while (true){
getline(cin, line);
if (cin.eof()){
cerr << "[fatal] [upfdater] cin.eof()" << endl;
exit(EXIT_FAILURE);
}
if (cin.bad()){
cerr << "[fatal] [upfdater] cin.bad() != 0" << endl;
cerr << "[fatal] [upfdater] cin.bad()" << endl;
exit(EXIT_FAILURE);
}
cerr << "[info] [updater] Updating configuration with line " << line << endl;
@@ -423,7 +24,9 @@ void config_updater (){
regex_rules *regex_new_config = new regex_rules();
while(!config_stream.eof()){
config_stream >> data;
regex_new_config->add(data.c_str());
if (data != "" && data != "\n"){
regex_new_config->add(data.c_str());
}
}
regex_config.reset(regex_new_config);
cerr << "[info] [updater] Config update done" << endl;
@@ -456,21 +59,3 @@ int main(int argc, char *argv[])
config_updater();
}
/*
libpcre2-dev
libnetfilter-queue-dev
libtins-dev
libmnl-dev
c++ nfqueue.cpp -o nfqueue -pthread -lpcre2-8 -ltins -lnetfilter_queue -lmnl
WORKDIR /tmp/
RUN git clone --branch release https://github.com/jpcre2/jpcre2
WORKDIR /tmp/jpcre2
RUN ./configure; make; make install
WORKDIR /
*/

28
backend/nfqueue/utils.hpp Normal file
View File

@@ -0,0 +1,28 @@
#include <string>
#include <unistd.h>
#ifndef UTILS_HPP
#define UTILS_HPP
bool unhexlify(std::string const &hex, std::string &newString) {
try{
int len = hex.length();
for(int i=0; i< len; i+=2)
{
std::string byte = hex.substr(i,2);
char chr = (char) (int)strtol(byte.c_str(), NULL, 16);
newString.push_back(chr);
}
return true;
}
catch (...){
return false;
}
}
bool is_sudo(){
return getuid() == 0;
}
#endif