🐞 fix(ftpserver): 修改被动模式端口号的分配方式

添加端口号区间，设置可重复绑定属性，使得端口号可控

filetransfer/ftpserver/fineftp-server/src/ftp_session.cpp

@@ -6,6 +6,7 @@
 #include <map>
 #include <functional>
 #include <fstream>
+#include <unistd.h>
 
 #include "filesystem.h"
 
@@ -13,6 +14,21 @@ namespace fineftp
 {
 
 const std::string DEVICEID_FILE_LOACLPATH = getenv("HOME") + std::string("/.connectivitycache/DeviceId");
+const int MAX_PORT_NUM = 6;
+const unsigned short INITIAL_PORT = 27193;
+
+std::queue<unsigned short> FtpSession::s_freePorts = FtpSession::initPortQueue();
+
+std::queue<unsigned short> FtpSession::initPortQueue()
+{
+    std::queue<unsigned short> freePorts;
+    for (int i = 0; i < MAX_PORT_NUM; i++) {
+        freePorts.push(INITIAL_PORT + i);
+    }
+
+    return freePorts;
+}
+
 
 FtpSession::FtpSession(asio::io_service &io_service, const UserDatabase &user_database,
                        const std::function<void()> &completion_handler)
@@ -313,39 +329,56 @@ void FtpSession::handleFtpCommandPASV(const std::string & /*param*/)
         }
     }
 
-    asio::ip::tcp::endpoint endpoint(asio::ip::tcp::v4(), 0);
-
-    {
-        asio::error_code ec;
-        data_acceptor_.open(endpoint.protocol(), ec);
-        if (ec) {
-            std::cerr << "Error opening data acceptor: " << ec.message() << std::endl;
-            sendFtpMessage(FtpReplyCode::SERVICE_NOT_AVAILABLE, "Failed to enter passive mode.");
-            return;
-        }
-    }
-    {
-        asio::error_code ec;
-        data_acceptor_.bind(endpoint);
-        if (ec) {
-            std::cerr << "Error binding data acceptor: " << ec.message() << std::endl;
-            sendFtpMessage(FtpReplyCode::SERVICE_NOT_AVAILABLE, "Failed to enter passive mode.");
-            return;
-        }
-    }
-    {
-        asio::error_code ec;
-        data_acceptor_.listen(asio::socket_base::max_connections, ec);
-        if (ec) {
-            std::cerr << "Error listening on data acceptor: " << ec.message() << std::endl;
-            sendFtpMessage(FtpReplyCode::SERVICE_NOT_AVAILABLE, "Failed to enter passive mode.");
-            return;
+    if (!s_freePorts.empty()) {
+        m_currentPort = s_freePorts.front();
+        s_freePorts.pop();
+        try {
+            asio::ip::tcp::endpoint endpoint(asio::ip::tcp::v4(), m_currentPort);
+            {
+                asio::error_code ec;
+                data_acceptor_.open(endpoint.protocol(), ec);
+                if (ec) {
+                    std::cerr << "Error opening data acceptor: " << ec.message() << std::endl;
+                    sendFtpMessage(FtpReplyCode::SERVICE_NOT_AVAILABLE, "Failed to enter passive mode.");
+                    return;
+                }
+            }
+            data_acceptor_.set_option(asio::ip::tcp::acceptor::reuse_address(true));
+            {
+                asio::error_code ec;
+                data_acceptor_.bind(endpoint);
+                if (ec) {
+                    std::cerr << "Error binding data acceptor: " << ec.message() << std::endl;
+                    sendFtpMessage(FtpReplyCode::SERVICE_NOT_AVAILABLE, "Failed to enter passive mode.");
+                    return;
+                }
+            }
+            {
+                asio::error_code ec;
+                data_acceptor_.listen(asio::socket_base::max_connections, ec);
+                if (ec) {
+                    std::cerr << "Error listening on data acceptor: " << ec.message() << std::endl;
+                    sendFtpMessage(FtpReplyCode::SERVICE_NOT_AVAILABLE, "Failed to enter passive mode.");
+                    return;
+                }
+            }
+        } catch (std::exception &_e) {
+#ifndef NDEBUG
+            std::cout << _e.what() << std::endl;
+#endif
+            s_freePorts.push(m_currentPort);
+            handleFtpCommandPASV("PASV");
         }
+    } else {
+#ifndef NDEBUG
+        std::cerr << "More than the maximum number of ports that can be allocated." << std::endl;
+#endif
+        return;
     }
 
     // Split address and port into bytes and get the port the OS chose for us
     auto ip_bytes = command_socket_.local_endpoint().address().to_v4().to_bytes();
-    auto port = data_acceptor_.local_endpoint().port();
+    // auto port = data_acceptor_.local_endpoint().port();
 
     std::ifstream file;
 
@@ -356,8 +389,8 @@ void FtpSession::handleFtpCommandPASV(const std::string & /*param*/)
         getline(file, deviceId);
         std::cout << deviceId << std::endl;
         if (!deviceId.empty()) {
-            std::string common = std::string("adb -s ") + deviceId + std::string(" reverse tcp:") + std::to_string(port)
-                                 + std::string(" tcp:") + std::to_string(port);
+            std::string common = std::string("adb -s ") + deviceId + std::string(" reverse tcp:")
+                                 + std::to_string(m_currentPort) + std::string(" tcp:") + std::to_string(m_currentPort);
             system(common.c_str());
         }
     }
@@ -369,9 +402,10 @@ void FtpSession::handleFtpCommandPASV(const std::string & /*param*/)
     for (size_t i = 0; i < 4; i++) {
         stream << static_cast<int>(ip_bytes[i]) << ",";
     }
-    stream << ((port >> 8) & 0xff) << "," << (port & 0xff) << ")";
+    stream << ((m_currentPort >> 8) & 0xff) << "," << (m_currentPort & 0xff) << ")";
 
     sendFtpMessage(FtpReplyCode::ENTERING_PASSIVE_MODE, "Entering passive mode " + stream.str());
+
     return;
 } // namespace fineftp
 
@@ -1053,7 +1087,8 @@ void FtpSession::addDataToBufferAndSend(std::shared_ptr<std::vector<char>> data,
 void FtpSession::writeDataToSocket(std::shared_ptr<asio::ip::tcp::socket> data_socket,
                                    std::function<void(void)> fetch_more)
 {
-    data_buffer_strand_.post([me = shared_from_this(), data_socket, fetch_more]() {
+    auto port = m_currentPort;
+    data_buffer_strand_.post([me = shared_from_this(), data_socket, fetch_more, port]() {
         auto data = me->data_buffer_.front();
 
         if (data) {
@@ -1078,6 +1113,9 @@ void FtpSession::writeDataToSocket(std::shared_ptr<asio::ip::tcp::socket> data_s
             // we got to the end of transmission
             me->data_buffer_.pop_front();
             me->sendFtpMessage(FtpReplyCode::CLOSING_DATA_CONNECTION, "Done");
+            s_freePorts.push(port);
+            data_socket->close();
+            // delete data_socket;
         }
     });
 }

filetransfer/ftpserver/fineftp-server/src/ftp_session.h

@@ -3,6 +3,7 @@
 #include <asio.hpp>
 
 #include <deque>
+#include <queue>
 #include <fstream>
 
 #include "ftp_message.h"
@@ -59,6 +60,8 @@ private:
 
     void handleFtpCommand(const std::string &command);
 
+    static std::queue<unsigned short> initPortQueue();
+
     ////////////////////////////////////////////////////////
     // FTP Commands
     ////////////////////////////////////////////////////////
@@ -199,5 +202,9 @@ private:
 
     // Current state
     std::string ftp_working_directory_;
+
+    unsigned short m_currentPort;
+
+    static std::queue<unsigned short> s_freePorts;
 };
 } // namespace fineftp