read webfuse specific command line arguments

CMakeLists.txt

@@ -20,6 +20,8 @@ add_library(webfuse_static STATIC
     src/webfuse/fuse.cpp
     src/webfuse/request_type.cpp
     src/webfuse/response_type.cpp
+    src/webfuse/util/commandline_args.cpp
+    src/webfuse/util/commandline_reader.cpp
     src/webfuse/filesystem.cpp
     src/webfuse/filesystem/status.cpp
     src/webfuse/filesystem/accessmode.cpp

src/webfuse/fuse.cpp

@@ -288,4 +288,17 @@ int fuse::run(int argc, char * argv[])
     return fuse_main(argc, argv, &operations, context);
 }
 
+void fuse::print_usage()
+{
+    struct fuse_operations operations;
+    memset(reinterpret_cast<void*>(&operations), 0, sizeof(operations));
+
+    int const argc = 2;
+    char progname[] = "webfuse";
+    char show_help[] = "--help";
+    char * argv[] = { progname, show_help, nullptr};
+    fuse_main(argc, argv, &operations, nullptr);
+}
+
+
 }

src/webfuse/fuse.hpp

@@ -16,6 +16,7 @@ public:
     fuse (fuse && other);
     fuse& operator=(fuse && other);
     int run(int argc, char * argv[]);
+    static void print_usage();
 private:
     class detail;
     detail * d;

src/webfuse/util/commandline_args.cpp

@@ -0,0 +1,56 @@
+#include "webfuse/util/commandline_args.hpp"
+#include <cstring>
+#include <stdexcept>
+
+namespace webfuse
+{
+
+commandline_args::commandline_args(char const * prog_name, int capacity)
+: capacity_(capacity)
+, argc(0)
+{
+    if (capacity < 1)
+    {
+        throw std::runtime_error("too few commandline args");
+    }
+
+    argv = new char*[capacity_ + 1];
+    argv[0] = nullptr;
+    push(prog_name);
+}
+
+commandline_args::~commandline_args()
+{
+    for(int i = 0; i < argc; i++)
+    {
+        free(argv[i]);
+    }
+    delete[] argv;
+}
+
+void commandline_args::push(char const * arg)
+{
+    if (argc < capacity_)
+    {
+        argv[argc] = strdup(arg);
+        argv[argc + 1] = nullptr;
+        argc++;
+    }
+    else
+    {
+        throw std::runtime_error("capacity exceeded");
+    }
+}
+
+int commandline_args::get_argc() const
+{
+    return argc;
+}
+
+char ** commandline_args::get_argv()
+{
+    return argv;
+}
+
+
+}

src/webfuse/util/commandline_args.hpp

@@ -0,0 +1,29 @@
+#ifndef WEBFUSE_COMMANDLINE_ARGS_HPP
+#define WEBFUSE_COMMANDLINE_ARGS_HPP
+
+namespace webfuse
+{
+
+class commandline_args
+{
+    commandline_args (commandline_args const &) = delete;
+    commandline_args& operator=(commandline_args const &) = delete;
+    commandline_args (commandline_args &&) = delete;
+    commandline_args& operator=(commandline_args &&) = delete;
+public:
+    commandline_args(char const * prog_name, int capacity);
+    ~commandline_args();
+
+    void push(char const * arg);
+    int get_argc() const;
+    char ** get_argv();
+
+private:
+    int capacity_;
+    int argc;
+    char ** argv;
+};
+
+}
+
+#endif

src/webfuse/util/commandline_reader.cpp

@@ -0,0 +1,30 @@
+#include "webfuse/util/commandline_reader.hpp"
+namespace webfuse
+{
+
+commandline_reader::commandline_reader(int argc, char * argv[])
+: current_(0)
+, argc_(argc)
+, argv_(argv)
+{
+
+}
+
+bool commandline_reader::next()
+{
+    if (current_ < argc_)
+    {
+        current_++;
+    }
+
+    bool const has_next = (current_ < argc_);
+    return has_next;
+}
+
+char const * commandline_reader::current() const
+{
+    return argv_[current_];
+}
+
+
+}

src/webfuse/util/commandline_reader.hpp

@@ -0,0 +1,22 @@
+#ifndef WEBFUSE_COMMANDLINE_READER_HPP
+#define WEBFUSE_COMMANDLINE_READER_HPP
+
+namespace webfuse
+{
+
+class commandline_reader
+{
+public:
+    commandline_reader(int argc, char * argv[]);
+    ~commandline_reader() = default;
+    bool next();
+    char const * current() const;
+private:
+    int current_;
+    int argc_;
+    char ** argv_;    
+};
+
+}
+
+#endif

src/webfuse/webfuse.cpp

@@ -3,17 +3,43 @@
 #include "webfuse/filesystem.hpp"
 #include "webfuse/ws/server.hpp"
 
+#include <iostream>
+
 namespace webfuse
 {
 
 int app::run(int argc, char * argv[]) // NOLINT(readability-convert-member-functions-to-static)
 {
-    ws_config config;
+    ws_config config(argc, argv);
+
+    switch (config.cmd)
+    {
+        case command::run:
+            {
                 ws_server server(config);
                 filesystem filesystem(server);
                 fuse fuse_fs(filesystem);
 
-    return fuse_fs.run(argc, argv);
+                config.exit_code = fuse_fs.run(config.args.get_argc(), config.args.get_argv());
+            }
+            break;
+        case command::show_help:
+            // fall-through
+        default:
+            {
+                fuse::print_usage();
+                std::cout << R"(
+WEBFUSE options:
+    --wf-port PORT      port number of websocket server (default: 8081)
+    --wf-vhost VHOST    name of the virtual host (default: localhost)
+    --wf-cert PATH      path of the server's public certificate (optional)
+    --wf-key  PATH      path of the server's private key (optional)
+)";
+            }
+            break;
+    }
+
+    return config.exit_code;
 }
 
 }

src/webfuse/ws/config.cpp

@@ -1,19 +1,99 @@
 #include "webfuse/ws/config.hpp"
+#include "webfuse/util/commandline_reader.hpp"
+
+#include <iostream>
 
 namespace
 {
 
 constexpr int const default_port = 8081;
+constexpr char const default_vhost_name[] = "localhost";
+
+void verify(webfuse::ws_config & config)
+{
+    if (config.cmd == webfuse::command::run)
+    {
+        if ((config.use_tls) && ((config.key_path.empty()) || (config.cert_path.empty())))
+        {
+            std::cerr << "error: use of TLS requires both, key ander certificate path" << std::endl;
+            config.cmd = webfuse::command::show_help;
+            config.exit_code = EXIT_FAILURE;
+        }
+    }
+}
+
+bool get_arg(webfuse::ws_config & config, webfuse::commandline_reader& reader, std::string & value, std::string const error_message)
+{
+    const bool has_next = reader.next();
+    if (has_next)
+    {
+        value = reader.current();
+    }
+    else
+    {
+        std::cerr << "error: " << error_message << std::endl;
+        config.cmd = webfuse::command::show_help;
+        config.exit_code = EXIT_FAILURE;
+    }
+
+    return has_next;
+}
 
 }
 
 namespace webfuse
 {
 
-ws_config::ws_config()
+ws_config::ws_config(int argc, char * argv[])
-: port(default_port)
+: exit_code(EXIT_SUCCESS)
+, args(argv[0], argc)
+, cmd(command::run)
+, port(default_port)
+, vhost_name(default_vhost_name)
+, use_tls(false)
 {
+    commandline_reader reader(argc, argv);
 
+    while ((exit_code == EXIT_SUCCESS) && (reader.next()))
+    {
+        std::string const arg = reader.current();
+        if ((arg == "-h") || (arg == "--help"))
+        {
+            cmd = command::show_help;
+        }
+        else if (arg == "--wf-port")
+        {
+            std::string value;
+            if (get_arg(*this, reader, value, "missing PORT"))
+            {
+                port = static_cast<uint16_t>(std::stoi(value));
+            }
+        }
+        else if (arg == "--wf-vhost")
+        {
+            get_arg(*this, reader, vhost_name, "missing VHOST");
+        }
+        else if (arg == "--wf-key")
+        {
+            if (get_arg(*this, reader, key_path, "missing KEY_PATH"))
+            {
+                use_tls = true;
+            }
+        }
+        else if (arg == "--wf-cert")
+        {
+            if (get_arg(*this, reader, cert_path, "missing CERT_PATH"))
+            {
+                use_tls = true;
+            }
+        }
+        else
+        {
+            args.push(arg.c_str());
+        }
+    }
+
+    verify(*this);
 }
 
 

src/webfuse/ws/config.hpp

@@ -1,17 +1,35 @@
 #ifndef WEBFUSE_WS_CONFIG_HPP
 #define WEBFUSE_WS_CONFIG_HPP
 
+#include <webfuse/util/commandline_args.hpp>
+
 #include <cinttypes>
+#include <string>
 
 namespace webfuse
 {
 
+enum class command
+{
+    run,
+    show_help
+};
+
 class ws_config
 {
 public:
-    ws_config();
+    ws_config(int argc, char * argv[]);
+
+    int exit_code;
+    commandline_args args;
+    command cmd;
 
     uint16_t port;
+    std::string vhost_name;
+
+    bool use_tls;
+    std::string cert_path;
+    std::string key_path;
 };
 
 }