Add ability to redirect log output to custom streams (#75)

By default, log output will be printed to cout and cerr, but now custom streams can be provided to redirect them.

---------

Co-authored-by: Florian Reimold <[email protected]>

fineftp-server/include/fineftp/server.h

@@ -4,6 +4,7 @@
 #include <cstdint>
 #include <memory>
 #include <string>
+#include <iostream>
 
 // IWYU pragma: begin_exports
 #include <fineftp/permissions.h>
@@ -40,6 +41,25 @@ namespace fineftp
   class FtpServer
   {
   public:
+    /**
+     * @brief Creates an FTP Server instance that will listen on the the given control port and accept connections from the given network interface.
+     * 
+     * Instead of binding the server to a specific address, the server can
+     * listen on any interface by providing "0.0.0.0" as address.
+     * 
+     * Instead of using a predefined port, the operating system can choose a
+     * free port port. Use port=0, if that behaviour is desired. The chosen port
+     * can be determined by with getPort().
+     * 
+     * This constructor will accept streams for info and error log output.
+     * 
+     * @param address: The address to accept incoming connections from. Use "0.0.0.0" to accept connections from any address.
+     * @param port: The port to start the FTP server on. Use 0 to let the operating system choose a free port. Use 21 for using the default FTP port.
+     * @param output: Stream for info log output. Defaults to std::cout if constructors without that options are used.
+     * @param error: Stream for error log output. Defaults to std::cerr if constructors without that options are used.
+     */
+    FINEFTP_EXPORT FtpServer(const std::string& address, uint16_t port, std::ostream& output, std::ostream& error);
+
     /**
      * @brief Creates an FTP Server instance that will listen on the the given control port and accept connections from the given network interface.
      * 
@@ -50,6 +70,9 @@ namespace fineftp
      * free port port. Use port=0, if that behaviour is desired. The chosen port
      * can be determined by with getPort().
      * 
+     * Logs will be printed to std::cout and std::cerr. If you want to use a
+     * different output stream, use the other constructor.
+     * 
      * @param port: The port to start the FTP server on. Defaults to 21.
      * @param host: The host to accept incoming connections from.
      */
@@ -64,15 +87,18 @@ namespace fineftp
      * Instead of using a predefined port, the operating system can choose a
      * free port port. Use port=0, if that behaviour is desired. The chosen port
      * can be determined by with getPort().
-     *
+     * 
      * This constructor will create an FTP Server binding to IPv4 0.0.0.0 and
      * Thus accepting connections from any IPv4 address.
      * For security reasons it might be desirable to bind to a specific IP
      * address. Use FtpServer(const std::string&, uint16_t) for that purpose.
-     *
+     * 
+     * Logs will be printed to std::cout and std::cerr. If you want to use a
+     * different output stream, use the other constructor.
+     * 
      * @param port: The port to start the FTP server on. Defaults to 21.
      */
-    FINEFTP_EXPORT FtpServer(uint16_t port = 21);
+    FINEFTP_EXPORT explicit FtpServer(uint16_t port = 21);
 
     // Move
     FINEFTP_EXPORT FtpServer(FtpServer&&) noexcept;
@@ -103,11 +129,11 @@ namespace fineftp
      * @param password:         The user's password
      * @param local_root_path:  A path to any resource on the local filesystem that will be accessed by the user
      * @param permissions:      A bit-mask of what the user will be able to do.
-     * 
+     *
      * @return True if adding the user was successful (i.e. it didn't exit already).
      */
     FINEFTP_EXPORT bool addUser(const std::string& username, const std::string& password, const std::string& local_root_path, Permission permissions);
-    
+
     /**
      * @brief Adds the "anonymous" / "ftp" user that FTP clients use to access FTP servers without password
      * 
@@ -137,7 +163,7 @@ namespace fineftp
 
     /**
      * @brief Returns the number of currently open connections
-     *
+     * 
      * @return the number of open connections
      */
     FINEFTP_EXPORT int getOpenConnectionCount() const;

fineftp-server/src/filesystem.cpp

@@ -283,7 +283,7 @@ namespace Filesystem
     return can_open_dir;
   }
 
-  std::map<std::string, FileStatus> dirContent(const std::string& path)
+  std::map<std::string, FileStatus> dirContent(const std::string& path, std::ostream& error)
   {
     std::map<std::string, FileStatus> content;
 #ifdef WIN32
@@ -297,7 +297,7 @@ namespace Filesystem
     hFind = FindFirstFileW(w_find_file_path.c_str(), &ffd);
     if (hFind == INVALID_HANDLE_VALUE)
     {
-      std::cerr << "FindFirstFile Error" << std::endl;
+      error << "FindFirstFile Error" << std::endl;
       return content;
     }
 
@@ -312,7 +312,7 @@ namespace Filesystem
     struct dirent *dirp = nullptr;
     if(dp == nullptr)
     {
-        std::cerr << "Error opening directory: " << strerror(errno) << std::endl;
+        error << "Error opening directory: " << strerror(errno) << std::endl;
         return content;
     }
 

fineftp-server/src/filesystem.h

@@ -3,6 +3,7 @@
 #include <cstdint>
 #include <map>
 #include <string>
+#include <iostream>
 
 #include <sys/stat.h>
 
@@ -68,7 +69,7 @@ namespace fineftp
   #endif 
     };
 
-    std::map<std::string, FileStatus> dirContent(const std::string& path);
+    std::map<std::string, FileStatus> dirContent(const std::string& path, std::ostream& error);
 
     std::string cleanPath(const std::string& path, bool path_is_windows_path, char output_separator);
 

fineftp-server/src/ftp_session.cpp

@@ -1,9 +1,11 @@
 #include "ftp_session.h"
 
+#include <asio.hpp>
+
 #include <algorithm>
 #include <cassert> // assert
 #include <cctype>  // std::iscntrl, toupper
-#include <chrono>
+#include <chrono>   // IWYU pragma: keep (it is used for special preprocessor defines)
 #include <cstddef>
 #include <cstdio>
 #include <fstream>
@@ -28,6 +30,11 @@
 #include <sys/stat.h>
 
 #ifdef WIN32
+  #define WIN32_LEAN_AND_MEAN
+  #ifndef NOMINMAX
+    #define NOMINMAX
+  #endif
+  #include <windows.h>
   #include "win_str_convert.h"
 #else
   #include <unistd.h>
@@ -37,7 +44,7 @@
 namespace fineftp
 {
 
-  FtpSession::FtpSession(asio::io_service& io_service, const UserDatabase& user_database, const std::function<void()>& completion_handler)
+  FtpSession::FtpSession(asio::io_service& io_service, const UserDatabase& user_database, const std::function<void()>& completion_handler, std::ostream& output, std::ostream& error)
     : completion_handler_   (completion_handler)
     , user_database_        (user_database)
     , io_service_           (io_service)
@@ -49,13 +56,15 @@ namespace fineftp
     , data_acceptor_        (io_service)
     , data_socket_strand_   (io_service)
     , timer_                (io_service)
+    , output_(output)
+    , error_(error)
   {
   }
 
   FtpSession::~FtpSession()
   {
 #ifndef NDEBUG
-    std::cout << "Ftp Session shutting down" << std::endl;
+    output_ << "Ftp Session shutting down" << std::endl;
 #endif // !NDEBUG
 
     {
@@ -85,7 +94,7 @@ namespace fineftp
   {
     asio::error_code ec;
     command_socket_.set_option(asio::ip::tcp::no_delay(true), ec);
-    if (ec) std::cerr << "Unable to set socket option tcp::no_delay: " << ec.message() << std::endl;
+    if (ec) error_ << "Unable to set socket option tcp::no_delay: " << ec.message() << std::endl;
 
     command_strand_.post([me = shared_from_this()]() { me->readFtpCommand(); });
     sendFtpMessage(FtpMessage(FtpReplyCode::SERVICE_READY_FOR_NEW_USER, "Welcome to fineFTP Server"));
@@ -121,7 +130,7 @@ namespace fineftp
   void FtpSession::startSendingMessages()
   {
 #ifndef NDEBUG
-    std::cout << "FTP >> " << command_output_queue_.front() << std::endl;
+    output_ << "FTP >> " << command_output_queue_.front() << std::endl;
 #endif
 
     asio::async_write(command_socket_
@@ -150,7 +159,7 @@ namespace fineftp
                         }
                         else
                         {
-                          std::cerr << "Command write error for message " << me->command_output_queue_.front() << ec.message() << std::endl;
+                          me->error_ << "Command write error for message " << me->command_output_queue_.front() << ec.message() << std::endl;
                         }
                       }
                     ));
@@ -165,12 +174,12 @@ namespace fineftp
                           {
                             if (ec != asio::error::eof)
                             {
-                              std::cerr << "read_until error: " << ec.message() << std::endl;
+                              me->error_ << "read_until error: " << ec.message() << std::endl;
                             }
 #ifndef NDEBUG
                             else
                             {
-                              std::cout << "Control connection closed by client." << std::endl;
+                              me->output_ << "Control connection closed by client." << std::endl;
                             }
 #endif // !NDEBUG
                             // Close the data connection, if it is open
@@ -198,7 +207,7 @@ namespace fineftp
 
                           stream.ignore(2); // Remove the "\r\n"
 #ifndef NDEBUG
-                          std::cout << "FTP << " << packet_string << std::endl;
+                          me->output_ << "FTP << " << packet_string << std::endl;
 #endif
 
                           me->handleFtpCommand(packet_string);
@@ -412,7 +421,7 @@ namespace fineftp
       data_acceptor_.close(ec);
       if (ec)
       {
-        std::cerr << "Error closing data acceptor: " << ec.message() << std::endl;
+        error_ << "Error closing data acceptor: " << ec.message() << std::endl;
       }
     }
 
@@ -423,7 +432,7 @@ namespace fineftp
       data_acceptor_.open(endpoint.protocol(), ec);
       if (ec)
       {
-        std::cerr << "Error opening data acceptor: " << ec.message() << std::endl;
+        error_ << "Error opening data acceptor: " << ec.message() << std::endl;
         sendFtpMessage(FtpReplyCode::SERVICE_NOT_AVAILABLE, "Failed to enter passive mode.");
         return;
       }
@@ -433,7 +442,7 @@ namespace fineftp
       data_acceptor_.bind(endpoint, ec);
       if (ec)
       {
-        std::cerr << "Error binding data acceptor: " << ec.message() << std::endl;
+        error_ << "Error binding data acceptor: " << ec.message() << std::endl;
         sendFtpMessage(FtpReplyCode::SERVICE_NOT_AVAILABLE, "Failed to enter passive mode.");
         return;
       }
@@ -443,7 +452,7 @@ namespace fineftp
       data_acceptor_.listen(asio::socket_base::max_connections, ec);
       if (ec)
       {
-        std::cerr << "Error listening on data acceptor: " << ec.message() << std::endl;
+        error_ << "Error listening on data acceptor: " << ec.message() << std::endl;
         sendFtpMessage(FtpReplyCode::SERVICE_NOT_AVAILABLE, "Failed to enter passive mode.");
         return;
       }
@@ -1060,7 +1069,7 @@ namespace fineftp
         if (dir_status.canOpenDir())
         {
           sendFtpMessage(FtpReplyCode::FILE_STATUS_OK_OPENING_DATA_CONNECTION, "Sending directory listing");
-          sendDirectoryListing(Filesystem::dirContent(local_path));
+          sendDirectoryListing(Filesystem::dirContent(local_path, error_));
           return;
         }
         else
@@ -1108,7 +1117,7 @@ namespace fineftp
         if (dir_status.canOpenDir())
         {
           sendFtpMessage(FtpReplyCode::FILE_STATUS_OK_OPENING_DATA_CONNECTION, "Sending name list");
-          sendNameList(Filesystem::dirContent(local_path));
+          sendNameList(Filesystem::dirContent(local_path, error_));
           return;
         }
         else
@@ -1374,7 +1383,7 @@ namespace fineftp
 
                                 if (ec)
                                 {
-                                  std::cerr << "Data write error: " << ec.message() << std::endl;
+                                  me->error_ << "Data write error: " << ec.message() << std::endl;
                                   return;
                                 }
 
@@ -1415,7 +1424,7 @@ namespace fineftp
                                 {
                                   if (ec)
                                   {
-                                    std::cerr << "Data transfer aborted: " << ec.message() << std::endl;
+                                    me->error_ << "Data transfer aborted: " << ec.message() << std::endl;
                                     me->sendFtpMessage(FtpReplyCode::TRANSFER_ABORTED, "Data transfer aborted");
                                     return;
                                   }

fineftp-server/src/ftp_session.h

@@ -33,7 +33,7 @@ namespace fineftp
   // Public API
   ////////////////////////////////////////////////////////
   public:
-    FtpSession(asio::io_service& io_service, const UserDatabase& user_database, const std::function<void()>& completion_handler);
+    FtpSession(asio::io_service& io_service, const UserDatabase& user_database, const std::function<void()>& completion_handler, std::ostream& output, std::ostream& error);
 
     // Copy (disabled, as we are inheriting from shared_from_this)
     FtpSession(const FtpSession&)            = delete;
@@ -209,5 +209,8 @@ namespace fineftp
     std::deque<std::shared_ptr<std::vector<char>>> data_buffer_;
 
     asio::steady_timer                             timer_;
+
+    std::ostream& output_;  /* Normal output log */
+    std::ostream& error_;   /* Error output log */
   };
 }

fineftp-server/src/server.cpp

@@ -2,22 +2,27 @@
 
 #include "server_impl.h"
 
+#include <cassert> // assert
+#include <cstddef> // size_t
+#include <cstdint> // uint16_t
 #include <memory>
+#include <ostream>
 #include <string>
-#include <cstdint> // uint16_t
-#include <cstddef> // size_t
-#include <cassert> // assert
 
 #include <fineftp/permissions.h>
 
 namespace fineftp
 {
-  FtpServer::FtpServer(const std::string& address, uint16_t port)
-    : ftp_server_(std::make_unique<FtpServerImpl>(address, port))
+  FtpServer::FtpServer(const std::string& address, const uint16_t port, std::ostream& output, std::ostream& error)
+    : ftp_server_(std::make_unique<FtpServerImpl>(address, port, output, error))
+  {}
+
+  FtpServer::FtpServer(const std::string& address, const uint16_t port)
+    : FtpServer(address, port, std::cout, std::cerr)
   {}
 
-  FtpServer::FtpServer(uint16_t port)
-    : FtpServer(std::string("0.0.0.0"), port)
+  FtpServer::FtpServer(const uint16_t port)
+    : FtpServer(std::string("0.0.0.0"), port, std::cout, std::cerr)
   {}
 
   // Move