Allow --logfile option

src/main.cpp

@@ -26,6 +26,7 @@ using cpputils::make_unique_ref;
 using std::cout;
 using std::endl;
 using std::vector;
+using boost::none;
 
 //TODO Support files > 4GB
 //TODO Improve parallelity.
@@ -54,9 +55,12 @@ void runFilesystem(const ProgramOptions &options) {
     //TODO This daemonize causes error messages when initializing CryDevice to get lost.
     //     However, initializing CryDevice might (?) already spawn threads and we have to do daemonization before that
     //     because it doesn't fork threads. What to do?
-    //TODO Setup stdout/stderr as log files so we see the program output when detached
     if (!options.foreground()) {
-        cpputils::daemonize("cryfs");
+        cpputils::daemonize();
+        if (options.logFile() == none) {
+            // Setup logging to syslog.
+            cpputils::logging::setLogger(spdlog::syslog_logger("cryfs", "cryfs", LOG_PID));
+        }
     }
     auto blockStore = make_unique_ref<OnDiskBlockStore>(bf::path(options.baseDir()));
     CryDevice device(std::move(config), std::move(blockStore));
@@ -72,6 +76,10 @@ int main(int argc, char *argv[]) {
     showVersion();
     
     ProgramOptions options = program_options::Parser(argc, argv).parse();
+    //TODO Test that --logfile parameter works. Should be: file if specified, otherwise stderr if foreground, else syslog.
+    if (options.logFile() != none) {
+        cpputils::logging::setLogger(spdlog::create<spdlog::sinks::simple_file_sink<std::mutex>>("cryfs", *options.logFile()));
+    }
     runFilesystem(options);
     return 0;
 }

src/program_options/Parser.cpp

@@ -1,6 +1,7 @@
 #include "Parser.h"
 #include "utils.h"
 #include <iostream>
+#include <boost/optional.hpp>
 
 namespace po = boost::program_options;
 using namespace cryfs::program_options;
@@ -9,6 +10,8 @@ using std::vector;
 using std::cerr;
 using std::endl;
 using std::string;
+using boost::optional;
+using boost::none;
 
 Parser::Parser(int argc, char *argv[]) :_options(_argsToVector(argc, argv)) {}
 
@@ -28,8 +31,12 @@ ProgramOptions Parser::parse() const {
     string mountDir = vm["mount-dir"].as<string>();
     string configFile = vm["config"].as<string>();
     bool foreground = vm.count("foreground");
+    optional<string> logfile = none;
+    if (vm.count("logfile")) {
+        logfile = vm["logfile"].as<string>();
+    }
 
-    return ProgramOptions(baseDir, mountDir, configFile, foreground, options.second);
+    return ProgramOptions(baseDir, mountDir, configFile, foreground, logfile, options.second);
 }
 
 po::variables_map Parser::_parseOptionsOrShowHelp(const vector<char*> options) {
@@ -61,8 +68,9 @@ void Parser::_addAllowedOptions(po::options_description *desc) {
     po::options_description options("Allowed options");
     options.add_options()
             ("help,h", "show help message")
-            ("config,c", po::value<string>()->required(), "Config file")
+            ("config,c", po::value<string>()->required(), "Configuration file")
             ("foreground,f", "Run CryFS in foreground.")
+            ("logfile", po::value<string>(), "Specify the file to write log messages to. If this is not specified, log messages will go to stdout, or syslog if CryFS is running in the background.")
             ;
     desc->add(options);
 }

src/program_options/ProgramOptions.cpp

@@ -5,9 +5,12 @@
 using namespace cryfs::program_options;
 using std::string;
 using std::vector;
+using boost::optional;
 
-ProgramOptions::ProgramOptions(const string &baseDir, const string &mountDir, const std::string &configFile, bool foreground, const vector<char*> &fuseOptions)
-    :_baseDir(baseDir), _mountDir(new char[mountDir.size()+1]), _configFile(configFile), _foreground(foreground), _fuseOptions(fuseOptions) {
+ProgramOptions::ProgramOptions(const string &baseDir, const string &mountDir, const string &configFile,
+                               bool foreground, const optional<string> &logFile, const vector<char*> &fuseOptions)
+    :_baseDir(baseDir), _mountDir(new char[mountDir.size()+1]), _configFile(configFile), _foreground(foreground),
+     _logFile(logFile), _fuseOptions(fuseOptions) {
     std::memcpy(_mountDir, mountDir.c_str(), mountDir.size()+1);
     // Fuse needs the mountDir passed as first option (first option = position 1, since 0 is the executable name)
     ASSERT(_fuseOptions.size() >= 1, "There has to be one parameter at least for the executable name");
@@ -34,6 +37,10 @@ bool ProgramOptions::foreground() const {
     return _foreground;
 }
 
+const optional<string> ProgramOptions::logFile() const {
+    return _logFile;
+}
+
 const vector<char *> &ProgramOptions::fuseOptions() const {
     return _fuseOptions;
 }

src/program_options/ProgramOptions.h

@@ -4,18 +4,22 @@
 
 #include <vector>
 #include <string>
+#include <boost/optional.hpp>
 
 namespace cryfs {
     namespace program_options {
         class ProgramOptions final {
         public:
-            ProgramOptions(const std::string &baseDir, const std::string &mountDir, const std::string &configFile, bool foreground, const std::vector<char *> &fuseOptions);
+            ProgramOptions(const std::string &baseDir, const std::string &mountDir, const std::string &configFile,
+                           bool foreground, const boost::optional<std::string> &logFile,
+                           const std::vector<char *> &fuseOptions);
             ~ProgramOptions();
 
             const std::string &baseDir() const;
             std::string mountDir() const;
             const std::string &configFile() const;
             bool foreground() const;
+            const boost::optional<std::string> logFile() const;
             const std::vector<char *> &fuseOptions() const;
 
         private:
@@ -23,6 +27,7 @@ namespace cryfs {
             char *_mountDir;
             std::string _configFile;
             bool _foreground;
+            boost::optional<std::string> _logFile;
             std::vector<char *> _fuseOptions;
         };
     }