diff --git a/.history b/.history
new file mode 100644
index 0000000000000000000000000000000000000000..90ad8d3759f01d46a7d76c9225eb6dc1b4a901ec
--- /dev/null
+++ b/.history
@@ -0,0 +1,113 @@
+commit 9450db11a189b4099ca8c5d4ccc4f303e2ee2320
+Author: Recolic <root@recolic.net>
+Date: Sun Jun 30 16:02:28 2019 +0800
+
+ Update README.md
+
+commit abbf82bfeba26c28a470447d3311236817e96d42
+Author: Recolic Keghart <root@recolic.net>
+Date: Tue Jun 11 21:33:38 2019 +0800
+
+ remove packed struct
+
+commit afed693fefd78a73dfd97e1b3929d619720b860a
+Author: Recolic Keghart <root@recolic.net>
+Date: Tue Jun 11 21:33:30 2019 +0800
+
+ remove packed struct
+
+commit 65ee23e090436f761ceb30fbff53638207d150de
+Author: Recolic Keghart <root@recolic.net>
+Date: Tue Jun 11 21:30:19 2019 +0800
+
+ update cmake
+
+commit 9f58b2ad47bddfdd338217f88a9491327a2d5f62
+Author: Recolic Keghart <root@recolic.net>
+Date: Tue Jun 11 21:27:26 2019 +0800
+
+ Done. Dynamic connection tested. (UDP lost control packet not tested!)
+
+commit 0badf744588c7e19b3ffbc02b9d384fb3ca8c669
+Author: Recolic Keghart <root@recolic.net>
+Date: Tue Jun 11 02:52:51 2019 +0800
+
+ DO NOT BUILD: finished but not debugged
+
+commit 13c1c79f50f28f365cc6938462047de9f9e37d3d
+Author: Recolic Keghart <root@recolic.net>
+Date: Mon Jun 10 18:57:58 2019 +0800
+
+ update readme
+
+commit ae8ba24d6bdd5218bc3db1a9fe364b27b32b55ca
+Author: Recolic <root@recolic.net>
+Date: Mon Jun 10 18:52:33 2019 +0800
+
+ Create LICENSE
+
+commit 35225ec5403aa1a3b69b42c994c41954da096be6
+Author: Recolic <root@recolic.net>
+Date: Mon Jun 10 18:49:57 2019 +0800
+
+ Update README.md
+
+commit a51bf7957bdaaf8531c76f2750742eb40ba06002
+Author: Recolic Keghart <root@recolic.net>
+Date: Mon Jun 10 18:49:00 2019 +0800
+
+ finished
+
+commit 3d48635f4dafba301574e8162296cb08dde36b0a
+Author: Recolic Keghart <root@recolic.net>
+Date: Mon Jun 10 18:05:26 2019 +0800
+
+ bug fix
+
+commit 79da4564218eed98cecf2a9ec3866a7e0ca142e6
+Author: Recolic Keghart <root@recolic.net>
+Date: Mon Jun 10 14:40:12 2019 +0800
+
+ bug fix
+
+commit 0675b0afedb596c141f49017ee7faf922419e068
+Author: Recolic Keghart <root@recolic.net>
+Date: Mon Jun 10 13:26:20 2019 +0800
+
+ DO NOT BUILD: A failing version for TCP
+
+commit 58aa632ca4ddb281b92a3e1c311f7738471c805f
+Author: Recolic Keghart <root@recolic.net>
+Date: Mon Jun 10 12:57:38 2019 +0800
+
+ seems working. push to server before cleanup
+
+commit ba09af0f49fcbb5abaa1b89cf7a536ae8cfc90e7
+Author: Recolic Keghart <root@recolic.net>
+Date: Mon Jun 10 11:55:23 2019 +0800
+
+ bugfix
+
+commit a85df551ee45be323cad86109d41b022338b8b69
+Author: Recolic Keghart <root@recolic.net>
+Date: Mon Jun 10 02:14:35 2019 +0800
+
+ bugfix
+
+commit 0c6943999f34bdf8f7fb6ae3b42c437b1c9aefac
+Author: Recolic Keghart <root@recolic.net>
+Date: Mon Jun 10 01:56:48 2019 +0800
+
+ bugfix
+
+commit 956b8af2b912e6f3983a4c621ff74e27d2280a4b
+Author: Recolic Keghart <root@recolic.net>
+Date: Mon Jun 10 01:52:24 2019 +0800
+
+ init
+
+commit 8cf5faddaa33926c98905dfd0184c2b39f61c5f6
+Author: Recolic Keghart <root@recolic.net>
+Date: Mon Jun 10 01:50:11 2019 +0800
+
+ init
diff --git a/CMakeLists.txt b/CMakeLists.txt
index b298babe029a8c0bdec4ecbf56e4a6e71938cc69..ab5a12d235533eecf070ae2c687fc541169823ad 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,14 +1,19 @@
-cmake_minimum_required(VERSION 3.14)
+cmake_minimum_required(VERSION 3.0)
project(udp_forwarder_ng)
find_package(rlib)
+find_package(Threads)
set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_FLAGS_DEBUG "-g -DMALLOC_CHECK_=2")
+set(CMAKE_CXX_FLAGS_RELEASE "-O3")
include_directories(./lib)
include_directories(.)
-
-add_executable(udp_forwarder_ng main.cc Forwarder.hpp Crypto.hpp Dictionary.hpp)
+add_executable(udp_forwarder_ng main.cc Forwarder.hpp Crypto.hpp Config.hpp Util.hpp)
target_link_libraries(udp_forwarder_ng r)
-add_executable(crypto_test test/TestCrypto.cc Crypto.hpp Dictionary.hpp)
+target_link_libraries(udp_forwarder_ng Threads::Threads)
+add_executable(crypto_test test/TestCrypto.cc Crypto.hpp Config.hpp)
target_link_libraries(crypto_test r)
+
+install(TARGETS udp_forwarder_ng DESTINATION /usr/bin)
diff --git a/Dictionary.hpp b/Config.hpp
similarity index 96%
rename from Dictionary.hpp
rename to Config.hpp
index 3e2c5bb9211cdae568b38906e558a6cee9e9b917..543396dc228da8b1ec7f50fe9b9389db6c1d572a 100644
--- a/Dictionary.hpp
+++ b/Config.hpp
@@ -3,8 +3,19 @@
#include <string>
+// DGRAM packet usually smaller than 1400B.
+constexpr size_t DGRAM_BUFFER_SIZE = 20480; // 20KiB
+// epoll buffer size.
+constexpr size_t MAX_EVENTS = 16;
+
+// Change a connection on every n seconds,
+// to reset the GFW deep-packet-inspection process.
+// ( Only if server side is encrypted, so nothing happens
+// to the real openvpn server.
+constexpr size_t SERVER_ENCRYPT_CONNECTION_TIMEOUT_SECONDS = 60;
+
+// a random long string to fill the buffer.
const std::string crypto_dictionary = R"RSTR(
-
Optimizing C++/Code optimization/Faster operations
< Optimizing C++‎ | Code optimization
Jump to navigationJump to search
diff --git a/Crypto.hpp b/Crypto.hpp
index 6b34cf78cad326931a7c49142f98f642f307c529..28e3dae0636dce594a39aa2f60fdff2ed4d8e965 100644
--- a/Crypto.hpp
+++ b/Crypto.hpp
@@ -8,7 +8,7 @@
#include <string>
#include <numeric>
#include <limits>
-#include "Dictionary.hpp"
+#include "Config.hpp"
#if defined(__linux__)
# include <endian.h>
@@ -25,10 +25,12 @@
using std::string;
+// WARNING: should be thread-safe.
class Crypto {
public:
Crypto() = default;
void convertL2R(string &data, const string &lKey, const string &rKey) {
+ // If data is empty, maybe it's a bare control msg: a exception maybe thrown.
// If lKey is not null, decrypt the data.
// If rKey is not null, encrypt the data.
if(!lKey.empty()) {
@@ -85,6 +87,8 @@ private:
if(data.size() < 8)
throw std::runtime_error("Decrypt: Data length less than 8. ");
string nonce = data.substr(0, 8);
+ if(uint64FromBinStr(nonce) == 0)
+ throw std::runtime_error("Bad nonce: nonce is zero: ctl msg not fucked.");
string toDecrypt = data.substr(8);
block_decrypt(toDecrypt, key, nonce);
@@ -106,6 +110,7 @@ private:
size_t dict_current_index = 0;
struct {
+ // This rand is just QUICK and good enough. Maybe still good enough for multi-threading.
uint64_t x=123456789, y=362436069, z=521288629;
uint64_t get() {
uint64_t t;
@@ -118,7 +123,10 @@ private:
y = z;
z = t ^ x ^ y;
- return z;
+ if(z != 0) // nonce can not be zero. zero nonce means control message.
+ return z;
+ else
+ return get();
}
} xorshf_rand;
diff --git a/Forwarder.hpp b/Forwarder.hpp
index d6f2f9b29dcf7d89a6b16d344c9539348ffb076b..c106628b8987ec68a96dc60ba1e7cd268aa1ddad 100644
--- a/Forwarder.hpp
+++ b/Forwarder.hpp
@@ -9,12 +9,38 @@
#include <picosha2.h>
#include <rlib/sys/sio.hpp>
#include <sys/epoll.h>
-#include <rlib/stdio.hpp>
-#include "Crypto.hpp"
+#include <thread>
+#include <Crypto.hpp>
+#include <unordered_map>
+#include "Config.hpp"
+#include "Util.hpp"
using std::string;
using namespace std::literals;
+inline void epoll_add_fd(fd_t epollFd, fd_t fd) {
+ epoll_event event {
+ .events = EPOLLIN,
+ .data = {
+ .fd = fd,
+ }
+ };
+ auto ret1 = epoll_ctl(epollFd, EPOLL_CTL_ADD, fd, &event);
+ if(ret1 == -1)
+ throw std::runtime_error("epoll_ctl failed.");
+}
+inline void epoll_del_fd(fd_t epollFd, fd_t fd) {
+ epoll_event event {
+ .events = EPOLLIN,
+ .data = {
+ .fd = fd,
+ }
+ };
+ auto ret1 = epoll_ctl(epollFd, EPOLL_CTL_DEL, fd, &event); // Can be nullptr since linux 2.6.9
+ if(ret1 == -1)
+ throw std::runtime_error("epoll_ctl failed.");
+}
+
class Forwarder {
public:
Forwarder(string listenAddr, uint16_t listenPort, string serverAddr, uint16_t serverPort, string lPassword,
@@ -29,40 +55,50 @@ public:
rKey = "";
}
-private:
- auto setup_epoll(fd_t listenFd, fd_t serverFd) {
- auto epollFd = epoll_create1(NULL);
- if(epollFd == -1)
- throw std::runtime_error("Failed to create epoll fd.");
-
- // setup epoll.
- epoll_event eventL {
- .events = EPOLLIN,
- .data.fd = listenFd,
- }, eventS {
- .events = EPOLLIN,
- .data.fd = serverFd,
- };
- auto ret1 = epoll_ctl(epollFd, EPOLL_CTL_ADD, listenFd, &eventL);
- auto ret2 = epoll_ctl(epollFd, EPOLL_CTL_ADD, serverFd, &eventS);
- if(ret1 == -1 or ret2 == -1)
- throw std::runtime_error("epoll_ctl failed.");
- return epollFd;
- }
-
public:
[[noreturn]] void run() {
- // setup connections.
auto listenFd = rlib::quick_listen(listenAddr, listenPort, true);
- auto serverFd = rlib::quick_connect(serverAddr, serverPort, true);
- auto epollFd = setup_epoll(listenFd, serverFd);
+ rlib_defer([=]{close(listenFd);});
+
+ auto epollFd = epoll_create1(0);
+ if(epollFd == -1)
+ throw std::runtime_error("Failed to create epoll fd.");
+ epoll_add_fd(epollFd, listenFd);
- constexpr size_t MAX_EVENTS = 16;
epoll_event events[MAX_EVENTS];
- // DGRAM packet usually smaller than 1400B.
- constexpr size_t DGRAM_BUFFER_SIZE = 20480; // 20KiB
char buffer[DGRAM_BUFFER_SIZE];
+ // WARN: If you want to modify this program to work for both TCP and UDP, PLEASE use rlib::sockIO::recv instead of fixed buffer.
+
+ // Map from serverSession to clientSession.
+ // If I see a packet from client, throw it to server.
+ // If I see a packet from server, I have to determine which client to throw it.
+ // So I have to record the map between client and server, one-to-one.
+
+ std::unordered_map<clientInfo, fd_t, clientInfoHash> client2server;
+ std::unordered_map<fd_t, clientInfo> server2client;
+ std::unordered_map<fd_t, size_t> server2wallTime;
+ // If connection creation time is less than walltime, the connection timed out.
+
+ auto connForNewClient = [&, this](const clientInfo &info) {
+ if(info.isNull()) throw std::runtime_error("Invalid client info");
+ auto serverFd = rlib::quick_connect(serverAddr, serverPort, true);
+ rlog.verbose("creating new connection... {}", serverFd);
+ client2server[info] = serverFd; // May overwrite existing element on server timing out.
+ server2client.insert(std::make_pair(serverFd, info));
+ server2wallTime.insert(std::make_pair(serverFd, getWallTime()));
+ epoll_add_fd(epollFd, serverFd);
+ return serverFd;
+ };
+ auto eraseServerConn = [&](fd_t fd) {
+ server2client.erase(fd);
+ server2wallTime.erase(fd);
+ epoll_del_fd(epollFd, fd);
+ close(fd);
+ };
+
+ rlog.info("Forwarding server working...");
+ rlog.info("Listening {}:{}, with upstream server {}:{}.", listenAddr, listenPort, serverAddr, serverPort);
// Main loop!
while(true) {
@@ -71,31 +107,169 @@ public:
throw std::runtime_error("epoll_wait failed.");
for(auto cter = 0; cter < nfds; ++cter) {
- auto recvFd = events[cter].data.fd;
- auto recvSideIsListenSide = recvFd == listenFd;
- auto anotherFd = recvSideIsListenSide ? serverFd : listenFd;
- const auto &recvSideKey = recvSideIsListenSide ? lKey : rKey;
- const auto &sendSideKey = recvSideIsListenSide ? rKey : lKey;
+ const auto recvFd = events[cter].data.fd;
+ const auto recvSideIsClientSide = server2client.find(recvFd) == server2client.end(); // is not server
+ const auto &recvSideKey = recvSideIsClientSide ? lKey : rKey;
+ const auto &sendSideKey = recvSideIsClientSide ? rKey : lKey;
+ rlog.debug("woke up fd {}, isCLient={}", recvFd, recvSideIsClientSide);
try {
- auto size = recvfrom(recvFd, buffer, DGRAM_BUFFER_SIZE, NULL, NULL, NULL);
- if(size == -1) {
- throw std::runtime_error("ERR: recvfrom returns -1. "s + strerror(errno));
+ size_t size;
+ fd_t anotherFd;
+ sockaddr *sendtoAddr = nullptr;
+ socklen_t sendtoAddrLen = 0;
+ clientInfo clientSideInfo;
+ // Recv /////////////////////////////////////////////////////////////////////////////////////
+ if(recvSideIsClientSide) {
+ // Client to Server packet.
+ auto &info = clientSideInfo;
+ size = recvfrom(recvFd, buffer, DGRAM_BUFFER_SIZE, 0, (sockaddr *)&info.addr, &info.len);
+ if(size == -1)
+ throw std::runtime_error("ERR: recvfrom returns -1. "s + strerror(errno));
+ auto pos = client2server.find(info);
+ if(pos == client2server.end())
+ anotherFd = connForNewClient(info);
+ else
+ anotherFd = pos->second;
+ }
+ else {
+ // Server to Client packet.
+ size = recvfrom(recvFd, buffer, DGRAM_BUFFER_SIZE, 0, nullptr, nullptr);
+ if(size == -1)
+ throw std::runtime_error("ERR: recvfrom returns -1. "s + strerror(errno));
+ clientInfo &info = server2client.at(recvFd); // If server not found, drop the msg. (The server may just timed out)
+ sendtoAddr = (sockaddr *)&info.addr;
+ sendtoAddrLen = info.len;
+ anotherFd = listenFd;
+ clientSideInfo = info;
}
+ // received raw data.
string bufferStr (std::begin(buffer), std::begin(buffer) + size);
+
+ // Addon: ConnTimeout ///////////////////////////////////////////////////////////////////////////
+ // Recolic: The GFW use deep-packet-inspection to fuck my OpenVPN connection in about 10 minutes.
+ // What if I change a new connection in every 1 minute?
+ // Try it.
+
+ if(bufferStr.size() >= sizeof(uint64_t)) {
+ // Check control msg. Its nonce is zero.
+ if(*(uint64_t*)bufferStr.data() == 0) {
+ if(recvSideIsClientSide) {
+ // ctl msg from client. (conn change req)
+ uint16_t previous_port, new_port;
+ if(bufferStr.size() < sizeof(uint64_t) + 2*sizeof(previous_port))
+ throw std::runtime_error("ctl msg from client too short.");
+ std::memcpy(&previous_port, bufferStr.data()+sizeof(uint64_t), sizeof(previous_port));
+ std::memcpy(&new_port, bufferStr.data()+sizeof(uint64_t)+sizeof(previous_port), sizeof(previous_port));
+ previous_port = be16toh(previous_port);
+ new_port = be16toh(new_port);
+
+ // getsockname on UDP ONLY works for the local port. Ignore the addr!
+ auto iter = std::find_if(client2server.begin(), client2server.end(), [previous_port](const auto &kv){
+ // Known bug 1632: If there's two udp client with different addr and same port. it booms.
+ return kv.first.getPortNum() == previous_port;
+ });
+ if(iter == client2server.end())
+ throw std::runtime_error("ctl msg from client: change conn: prev conn not exist.");
+
+ auto clientSideInfoBackup = clientSideInfo;
+ clientSideInfo.setPortNum(new_port);
+ auto serverFd = iter->second;
+ rlog.debug("Client requested to change conn:", previous_port, new_port);
+ server2client[serverFd].setPortNum(new_port);
+ client2server[clientSideInfo] = serverFd; // Old record is not erased now.
+
+ // send ACK to client(recvFd). Should use previous port.
+ // The client will see the ACK from OLD connection and erase it.
+ string ackStr (sizeof(uint64_t), '\0');
+ auto ret = sendto(recvFd, ackStr.data(), ackStr.size(), 0, (sockaddr*)&clientSideInfoBackup.addr, clientSideInfoBackup.len);
+ if(ret == -1)
+ throw std::runtime_error("Failed to send CONN CHANGE ACK");
+
+ // remove the ctl prefix
+ bufferStr = bufferStr.substr(sizeof(uint64_t) + 2*sizeof(previous_port));
+ }
+ else {
+ // ACK ctl msg from server (conn change ack)
+ if(bufferStr.size() != sizeof(uint64_t))
+ throw std::runtime_error("wrong ack ctl from server");
+ rlog.verbose("REMOVEING FD", recvFd);
+ eraseServerConn(recvFd);
+ continue; // nothing todo with bare ACK.
+ }
+ }
+ }
+
+ // Encrypt/Decrypt ///////////////////////////////////////////////////////////////////////////////
crypto.convertL2R(bufferStr, recvSideKey, sendSideKey);
+ // Encrypt/Decrypt End. Continue ConnTimeout Addon ///////////////////////////////////////////////
+
+ auto prepareConnChangeReq = [&](fd_t prevFd, fd_t newFd) {
+ clientInfo previous, newOne;
+ newOne.len = previous.len = sizeof(previous.addr);
+ auto ret = getsockname(prevFd, (sockaddr*)&previous.addr, &previous.len) +
+ getsockname(newFd, (sockaddr*)&newOne.addr, &newOne.len);
+ if(ret != 0)
+ throw std::runtime_error("getsockname failed.");
+ auto previous_port = htobe16(previous.getPortNum()),
+ new_port = htobe16(newOne.getPortNum());
+ rlog.debug("COnnChangeReq (port num in BIG ENDIAN):", previous_port, new_port);
+
+ // Add control header.
+ bufferStr = string(sizeof(uint64_t) + sizeof(previous_port)*2, '\0') + bufferStr;
+ std::memcpy((char*)bufferStr.data()+sizeof(uint64_t), &previous_port, sizeof(previous_port));
+ std::memcpy((char*)bufferStr.data()+sizeof(uint64_t)+sizeof(previous_port), &new_port, sizeof(new_port));
+ };
+
+ if(recvSideIsClientSide && !sendSideKey.empty()) {
+ // Check server connection timeout.
+ // Only timeout the connection if server-side is encrypted. Or OpenVPN server will confuse.
+ // If the connection is timeout:
+ // 1. Create the new connection, reset timeout, update client2server and insert server2client.
+ // 2. Attach the control header onto the origin data packet, send it on the new connection.
+ // When received message from server, if server2client doesn't match client2server, meaning
+ // that this connection is already timed out.
+ // If the message is ACK control message, remove the old entry in server2client.
+ // Otherwise, resend the bare control header in previous step 2.
+ if(server2wallTime.at(anotherFd) < getWallTime()) {
+ // This connection timed out.
+ rlog.verbose("A Connection timed out, creating new conn...");
+ auto newConnFd = connForNewClient(clientSideInfo);
+ prepareConnChangeReq(anotherFd, newConnFd);
+ }
+ }
- size = sendto(anotherFd, bufferStr.data(), bufferStr.size(), NULL, NULL, NULL);
+ if(!recvSideIsClientSide) {
+ // server to client: I said to change conn but server still using old conn.
+ // Maybe my req lost. resend.
+ auto clientOwnerFd = client2server.at(server2client.at(recvFd));
+ if(clientOwnerFd != recvFd) {
+ // Client2server already modified, but not receiving ACK.
+ prepareConnChangeReq(recvFd, clientOwnerFd);
+ }
+ }
+
+ // Send /////////////////////////////////////////////////////////////////////////////////////
+ rlog.debug("sending on fd", anotherFd);
+ if(recvSideIsClientSide) {
+ // Client to Server packet.
+ size = send(anotherFd, bufferStr.data(), bufferStr.size(), 0);
+ }
+ else {
+ // Server to Client packet.
+ size = sendto(anotherFd, bufferStr.data(), bufferStr.size(), 0, sendtoAddr, sendtoAddrLen);
+ }
if(size == -1) {
- throw std::runtime_error("ERR: sendto returns -1. "s + strerror(errno));
+ throw std::runtime_error("sendto returns -1. "s + strerror(errno));
}
if(size != bufferStr.size()) {
- rlib::println("ERR: sendto not sent all data.");
+ rlog.warning("sendto not sent all data.");
}
+ // Done /////////////////////////////////////////////////////////////////////////////////////
}
catch(std::exception &e) {
- rlib::println(e.what());
+ rlog.error(e.what());
}
}
}
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000000000000000000000000000000000000..f288702d2fa16d3cdf0035b15a9fcbc552cd88e7
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,674 @@
+ GNU GENERAL PUBLIC LICENSE
+ Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+ Preamble
+
+ The GNU General Public License is a free, copyleft license for
+software and other kinds of works.
+
+ The licenses for most software and other practical works are designed
+to take away your freedom to share and change the works. By contrast,
+the GNU General Public License is intended to guarantee your freedom to
+share and change all versions of a program--to make sure it remains free
+software for all its users. We, the Free Software Foundation, use the
+GNU General Public License for most of our software; it applies also to
+any other work released this way by its authors. You can apply it to
+your programs, too.
+
+ When we speak of free software, we are referring to freedom, not
+price. Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+them if you wish), that you receive source code or can get it if you
+want it, that you can change the software or use pieces of it in new
+free programs, and that you know you can do these things.
+
+ To protect your rights, we need to prevent others from denying you
+these rights or asking you to surrender the rights. Therefore, you have
+certain responsibilities if you distribute copies of the software, or if
+you modify it: responsibilities to respect the freedom of others.
+
+ For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must pass on to the recipients the same
+freedoms that you received. You must make sure that they, too, receive
+or can get the source code. And you must show them these terms so they
+know their rights.
+
+ Developers that use the GNU GPL protect your rights with two steps:
+(1) assert copyright on the software, and (2) offer you this License
+giving you legal permission to copy, distribute and/or modify it.
+
+ For the developers' and authors' protection, the GPL clearly explains
+that there is no warranty for this free software. For both users' and
+authors' sake, the GPL requires that modified versions be marked as
+changed, so that their problems will not be attributed erroneously to
+authors of previous versions.
+
+ Some devices are designed to deny users access to install or run
+modified versions of the software inside them, although the manufacturer
+can do so. This is fundamentally incompatible with the aim of
+protecting users' freedom to change the software. The systematic
+pattern of such abuse occurs in the area of products for individuals to
+use, which is precisely where it is most unacceptable. Therefore, we
+have designed this version of the GPL to prohibit the practice for those
+products. If such problems arise substantially in other domains, we
+stand ready to extend this provision to those domains in future versions
+of the GPL, as needed to protect the freedom of users.
+
+ Finally, every program is threatened constantly by software patents.
+States should not allow patents to restrict development and use of
+software on general-purpose computers, but in those that do, we wish to
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+ END OF TERMS AND CONDITIONS
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+ How to Apply These Terms to Your New Programs
+
+ If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
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+
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+state the exclusion of warranty; and each file should have at least
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+
+ <one line to give the program's name and a brief idea of what it does.>
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+ This is free software, and you are welcome to redistribute it
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+The hypothetical commands `show w' and `show c' should show the appropriate
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+
+ The GNU General Public License does not permit incorporating your program
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+Public License instead of this License. But first, please read
+<https://www.gnu.org/licenses/why-not-lgpl.html>.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000000000000000000000000000000000000..382bf31d733f2959682cf3bddeefc15c03f19a4c
--- /dev/null
+++ b/README.md
@@ -0,0 +1,52 @@
+# UDP forwarder
+
+A simple **UNSAFE** tool to encrypt / hide your UDP packets. Trying to trick The Great Firewall deep learning VPN detection
+model. The packet can be easily decrypted if attacker checks the source code.
+
+This tool is usually used with OpenVPN, to avoid being `deep-learned` by the GFW. OpenVPN already encrypted the packets,
+so I needn't do it again.
+
+## NOTE
+
+DO NOT USE MASTER BRANCH. It's still under debugging. (the connection migration is not stable)
+
+## Design
+
+
+
+## Build
+
+```
+mkdir build && cd build
+cmake .. && make
+./udp_forwarder_ng [args ...]
+```
+
+## Common Deployment
+
+
+
+## Common mistake
+
+If you run OpenVPN and udp_forwarder on the same PC, you won't access the Internet successfully.
+If you did it, please think again and you'll realize how stupid you are.
+
+## Naive performance test
+
+Note: the connection setup procedure maybe a little slow, but it doesn't matter.
+
+- Latency
+
+with proxy: (encrypted OpenVPN + encrypted&obfs udp_forwarder_ng) 70.386ms
+
+without proxy: 0.475ms + 68.578ms = 69.053ms
+
+overhead (OpenVPN+Forwarder): 1.333ms
+
+## Known bug
+
+Every UDP Forwarder, will drop the first client2server packet. (Doesn't matter).
+
+Every UDP Forwarder, will drop
+
+I assume that every connection has a unique port. search for comment tag `1632`
diff --git a/Util.hpp b/Util.hpp
new file mode 100644
index 0000000000000000000000000000000000000000..530e3381d2ffb41e0cfcabcd4e625db395d11ba0
--- /dev/null
+++ b/Util.hpp
@@ -0,0 +1,149 @@
+//
+// Created by recolic on 19-6-10.
+//
+
+#ifndef UDP_FORWARDER_NG_CONNECTIONTIMEOUTCTL_HPP
+#define UDP_FORWARDER_NG_CONNECTIONTIMEOUTCTL_HPP
+
+
+#include <cstddef>
+#include <rlib/sys/fd.hpp>
+#include <ctime>
+#include <rlib/log.hpp>
+
+extern rlib::logger rlog;
+
+inline size_t getWallTime() {
+ auto seconds = static_cast<size_t>(std::time(nullptr));
+ return seconds / SERVER_ENCRYPT_CONNECTION_TIMEOUT_SECONDS;
+}
+
+
+inline char nibbleToHex(int nibble)
+{
+ const int ascii_zero = 48;
+ const int ascii_a = 65;
+
+ if((nibble >= 0) && (nibble <= 9))
+ {
+ return (char) (nibble + ascii_zero);
+ }
+ if((nibble >= 10) && (nibble <= 15))
+ {
+ return (char) (nibble - 10 + ascii_a);
+ }
+ return '?';
+}
+inline string char2str(char byteVal)
+{
+ int upp = (byteVal & 0xF0) >> 4;
+ int low = (byteVal & 0x0F);
+ return std::string() + nibbleToHex(upp) + nibbleToHex(low);
+}
+
+template <typename T>
+inline string printBinaryObj(const T &obj) {
+ string res = "[";
+ const char *p = (const char *)&obj;
+ for(auto i = 0; i < sizeof(T); ++i) {
+ res += char2str(p[i]) + ' ';
+ }
+ return res + "]";
+}
+
+struct clientInfo {
+ sockaddr_storage addr; socklen_t len;
+ bool operator==(const clientInfo &another) const {
+ return do_compare(another, true);
+ }
+ bool matchWildcard(const clientInfo &another) const {
+ return do_compare(another, false);
+ }
+ bool do_compare(const clientInfo &another, bool need_same_addr = true) const {
+ const auto *me = (const sockaddr_in*)&this->addr;
+ const auto *an = (const sockaddr_in*)&another.addr;
+
+ if(me->sin_family != an->sin_family)
+ return false;
+ if(me->sin_family == AF_INET) {
+ auto same_addr = std::memcmp(&me->sin_addr, &an->sin_addr, sizeof(me->sin_addr)) == 0;
+ auto same_port = me->sin_port == an->sin_port;
+ return need_same_addr ? same_addr && same_port : same_port;
+ }
+ else if(me->sin_family == AF_INET6) {
+ const auto *me = (const sockaddr_in6*)&this->addr;
+ const auto *an = (const sockaddr_in6*)&another.addr;
+ auto same_addr = std::memcmp(&me->sin6_addr, &an->sin6_addr, sizeof(me->sin6_addr)) == 0;
+ auto same_port = me->sin6_port == an->sin6_port;
+ return need_same_addr ? same_addr && same_port : same_port;
+ }
+ else
+ throw std::runtime_error("Invalid client info: sin_family is not AF_INET or AF_INET6");
+ }
+ bool isNull() const {
+ for(auto cter = 0; cter < sizeof(addr); ++cter) {
+ if(cter[(char *)&addr] != 0)
+ return false;
+ }
+ return true;
+ }
+ uint16_t getPortNum() const {
+ const auto *me = (const sockaddr_in*)&this->addr;
+ if(me->sin_family == AF_INET) {
+ return me->sin_port;
+
+ }
+ else if(me->sin_family == AF_INET6) {
+ const auto *me = (const sockaddr_in6*)&this->addr;
+ return me->sin6_port;
+ }
+ else
+ throw std::runtime_error("Invalid client info: sin_family is not AF_INET or AF_INET6: got " + std::to_string(me->sin_family));
+ }
+ void setPortNum(uint16_t port) {
+ auto *me = (sockaddr_in*)&this->addr;
+ if(me->sin_family == AF_INET) {
+ me->sin_port = port;
+ }
+ else if(me->sin_family == AF_INET6) {
+ auto *me = (sockaddr_in6*)&this->addr;
+ me->sin6_port = port;
+ }
+ else
+ throw std::runtime_error("Invalid client info: sin_family is not AF_INET or AF_INET6: got " + std::to_string(me->sin_family));
+ }
+};
+struct clientInfoHash {std::size_t operator()(const clientInfo &info) const {return *(std::size_t*)&info.addr;}}; // hash basing on port number and part of ip (v4/v6) address.
+
+//// Change connection to encrypted server in every 1 minute to avoid GFW deep-packet-inspect.
+//class ConnectionTimeoutCtl {
+//public:
+// ConnectionTimeoutCtl(size_t timeoutSeconds, bool serverSideIsEncrypted)
+// : timeoutSeconds(timeoutSeconds), serverSideIsEncrypted(serverSideIsEncrypted) {
+// // If server side is unencrypted, set timeout to +inf.
+// }
+//
+// bool encryptedMessageIsControlMessage() {
+// // Client side operation.
+// // 1. Return true if the message is control message (nonce=0)
+// // 2. if the message is control msg, deal with it.
+// }
+//
+// fd_t shouldChangeConnection() {
+// // Server side operation.
+// // 1. Return new fd ONLY if the connection should time out AND the new connection is ready.
+// // else return -1.
+// // 2. This function should send the control message, and update the client2server map.
+// }
+//
+//
+
+
+
+//private:
+// size_t timeoutSeconds;
+// bool serverSideIsEncrypted;
+//};
+
+
+#endif //UDP_FORWARDER_NG_CONNECTIONTIMEOUTCTL_HPP
diff --git a/main.cc b/main.cc
index bbe4c75e97b234f100a8f37cecce6fe324d0b03c..3043fe8b0a3e5600fe589770835a036481a7bc30 100644
--- a/main.cc
+++ b/main.cc
@@ -1,19 +1,41 @@
#include <iostream>
#include <rlib/stdio.hpp>
#include <rlib/opt.hpp>
+#include "Forwarder.hpp"
+
+rlib::logger rlog(std::cerr);
+
using namespace rlib::literals;
int main(int argc, char **argv) {
rlib::opt_parser args(argc, argv);
if(args.getBoolArg("--help", "-h")) {
- rlib::println("Usage: {} -l listenAddr -p listenPort -s serverAddr -P serverPort -lp LPassword -rp R(emote)Password"_rs.format(args.getSelf()));
+ rlib::println("Usage: {} -l listenAddr -p listenPort -s serverAddr -P serverPort [-lp LPassword] [-rp R(emote)Password] [--log=error/info/verbose/debug]"_rs.format(args.getSelf()));
+ rlib::println("Leave LPassword for empty if listenAddr is other UDP application.");
+ rlib::println("Leave RPassword for empty if serverAddr is other UDP application.");
+ return 0;
}
auto listenAddr = args.getValueArg("-l");
auto listenPort = args.getValueArg("-p").as<uint16_t>();
auto serverAddr = args.getValueArg("-s");
auto serverPort = args.getValueArg("-P").as<uint16_t>();
- auto lPassword = args.getValueArg("-lp");
- auto rPassword = args.getValueArg("-rp");
+ auto lPassword = args.getValueArg("-lp", false, "");
+ auto rPassword = args.getValueArg("-rp", false, "");
+
+ auto log_level = args.getValueArg("--log", false, "info");
+ if(log_level == "error")
+ rlog.set_log_level(rlib::log_level_t::ERROR);
+ else if(log_level == "info")
+ rlog.set_log_level(rlib::log_level_t::INFO);
+ else if(log_level == "verbose")
+ rlog.set_log_level(rlib::log_level_t::VERBOSE);
+ else if(log_level == "debug")
+ rlog.set_log_level(rlib::log_level_t::DEBUG);
+ else
+ throw std::runtime_error("Unknown log level: " + log_level);
+
+ Forwarder fwd(listenAddr, listenPort, serverAddr, serverPort, lPassword, rPassword);
+ fwd.run();
return 0;
}
\ No newline at end of file
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