Add unix domain socket support

examples/CMakeLists.txt

@@ -93,6 +93,10 @@ add_executable(example_file_upload example_file_upload.cpp)
 add_warnings_optimizations(example_file_upload)
 target_link_libraries(example_file_upload PUBLIC Crow::Crow)
 
+add_executable(example_unix_socket example_unix_socket.cpp)
+add_warnings_optimizations(example_unix_socket)
+target_link_libraries(example_unix_socket PUBLIC Crow::Crow)
+
 if(MSVC)
   add_executable(example_vs example_vs.cpp)
   add_warnings_optimizations(example_vs)

examples/example_unix_socket.cpp

@@ -0,0 +1,18 @@
+#include "crow.h"
+
+#include <sys/stat.h>
+
+int main()
+{
+    crow::SimpleApp app;
+
+    CROW_ROUTE(app, "/")
+    ([]() {
+        return "Hello, world!";
+    });
+
+    std::string local_socket_path = "example.sock";
+    unlink(local_socket_path.c_str());
+    app.local_socket_path(local_socket_path).run();
+
+}

include/crow.h

@@ -5,6 +5,7 @@
 #include "crow/TinySHA1.hpp"
 #include "crow/settings.h"
 #include "crow/socket_adaptors.h"
+#include "crow/socket_acceptors.h"
 #include "crow/json.h"
 #include "crow/mustache.h"
 #include "crow/logging.h"

include/crow/app.h

@@ -202,11 +202,12 @@ namespace crow
         using self_t = Crow;
 
         /// \brief The HTTP server
-        using server_t = Server<Crow, SocketAdaptor, Middlewares...>;
-
+        using server_t = Server<Crow, TCPAcceptor, SocketAdaptor, Middlewares...>;
+        /// \brief An HTTP server that runs on unix domain socket
+        using unix_server_t = Server<Crow, UnixSocketAcceptor, UnixSocketAdaptor, Middlewares...>;
 #ifdef CROW_ENABLE_SSL
         /// \brief An HTTP server that runs on SSL with an SSLAdaptor
-        using ssl_server_t = Server<Crow, SSLAdaptor, Middlewares...>;
+        using ssl_server_t = Server<Crow, TCPAcceptor, SSLAdaptor, Middlewares...>;
 #endif
         Crow()
         {}
@@ -344,6 +345,20 @@ namespace crow
             return bindaddr_;
         }
 
+        /// \brief Disable tcp/ip and use unix domain socket instead
+        self_t& local_socket_path(std::string path)
+        {
+            bindaddr_ = path;
+            use_unix_ = true;
+            return *this;
+        }
+
+        /// \brief Get the unix domain socket path
+        std::string local_socket_path()
+        {
+            return bindaddr_;
+        }
+
         /// \brief Run the server on multiple threads using all available threads
         self_t& multithreaded()
         {
@@ -502,7 +517,8 @@ namespace crow
 #ifdef CROW_ENABLE_SSL
             if (ssl_used_)
             {
-                ssl_server_ = std::move(std::unique_ptr<ssl_server_t>(new ssl_server_t(this, bindaddr_, port_, server_name_, &middlewares_, concurrency_, timeout_, &ssl_context_)));
+                TCPAcceptor::endpoint endpoint(asio::ip::address::from_string(bindaddr_), port_);
+                ssl_server_ = std::move(std::unique_ptr<ssl_server_t>(new ssl_server_t(this, endpoint, server_name_, &middlewares_, concurrency_, timeout_, &ssl_context_)));
                 ssl_server_->set_tick_function(tick_interval_, tick_function_);
                 ssl_server_->signal_clear();
                 for (auto snum : signals_)
@@ -515,14 +531,30 @@ namespace crow
             else
 #endif
             {
-                server_ = std::move(std::unique_ptr<server_t>(new server_t(this, bindaddr_, port_, server_name_, &middlewares_, concurrency_, timeout_, nullptr)));
-                server_->set_tick_function(tick_interval_, tick_function_);
-                for (auto snum : signals_)
+                if (use_unix_)
                 {
-                    server_->signal_add(snum);
+                    UnixSocketAcceptor::endpoint endpoint(bindaddr_);
+                    unix_server_ = std::move(std::unique_ptr<unix_server_t>(new unix_server_t(this, endpoint, server_name_, &middlewares_, concurrency_, timeout_, nullptr)));
+                    unix_server_->set_tick_function(tick_interval_, tick_function_);
+                    for (auto snum : signals_)
+                    {
+                        unix_server_->signal_add(snum);
+                    }
+                    notify_server_start();
+                    unix_server_->run();
+                }
+                else
+                {
+                    TCPAcceptor::endpoint endpoint(asio::ip::address::from_string(bindaddr_), port_);
+                    server_ = std::move(std::unique_ptr<server_t>(new server_t(this, endpoint, server_name_, &middlewares_, concurrency_, timeout_, nullptr)));
+                    server_->set_tick_function(tick_interval_, tick_function_);
+                    for (auto snum : signals_)
+                    {
+                        server_->signal_add(snum);
+                    }
+                    notify_server_start();
+                    server_->run();
                 }
-                notify_server_start();
-                server_->run();
             }
         }
 
@@ -556,6 +588,7 @@ namespace crow
                     websocket->close("Server Application Terminated");
                 }
                 if (server_) { server_->stop(); }
+                if (unix_server_) { unix_server_->stop(); }
             }
         }
 
@@ -696,6 +729,8 @@ namespace crow
             }
             if (server_)
                 server_->wait_for_start();
+            else if (unix_server_)
+                unix_server_->wait_for_start();
 #ifdef CROW_ENABLE_SSL
             else if (ssl_server_)
                 ssl_server_->wait_for_start();
@@ -735,6 +770,7 @@ namespace crow
         uint64_t max_payload_{UINT64_MAX};
         std::string server_name_ = std::string("Crow/") + VERSION;
         std::string bindaddr_ = "0.0.0.0";
+        bool use_unix_ = false;
         size_t res_stream_threshold_ = 1048576;
         Router router_;
         bool static_routes_added_{false};
@@ -756,6 +792,7 @@ namespace crow
 #endif
 
         std::unique_ptr<server_t> server_;
+        std::unique_ptr<unix_server_t> unix_server_;
 
         std::vector<int> signals_{SIGINT, SIGTERM};
 

include/crow/http_connection.h

@@ -145,7 +145,7 @@ namespace crow
             req_.middleware_container = static_cast<void*>(middlewares_);
             req_.io_service = &adaptor_.get_io_service();
 
-            req_.remote_ip_address = adaptor_.remote_endpoint().address().to_string();
+            req_.remote_ip_address = adaptor_.address();
 
             add_keep_alive_ = req_.keep_alive;
             close_connection_ = req_.close_connection;

include/crow/http_server.h

@@ -37,21 +37,20 @@ namespace crow // NOTE: Already documented in "crow/app.h"
     using error_code = asio::error_code;
 #endif
     using tcp = asio::ip::tcp;
+    using stream_protocol = asio::local::stream_protocol;
 
-    template<typename Handler, typename Adaptor = SocketAdaptor, typename... Middlewares>
+    template<typename Handler, typename Acceptor = TCPAcceptor, typename Adaptor = SocketAdaptor, typename... Middlewares>
     class Server
     {
     public:
-        Server(Handler* handler, std::string bindaddr, uint16_t port, std::string server_name = std::string("Crow/") + VERSION, std::tuple<Middlewares...>* middlewares = nullptr, uint16_t concurrency = 1, uint8_t timeout = 5, typename Adaptor::context* adaptor_ctx = nullptr):
-          acceptor_(io_service_, tcp::endpoint(asio::ip::address::from_string(bindaddr), port)),
+        Server(Handler* handler, typename Acceptor::endpoint endpoint, std::string server_name = std::string("Crow/") + VERSION, std::tuple<Middlewares...>* middlewares = nullptr, uint16_t concurrency = 1, uint8_t timeout = 5, typename Adaptor::context* adaptor_ctx = nullptr):
+          acceptor_(io_service_, endpoint),
           signals_(io_service_),
           tick_timer_(io_service_),
           handler_(handler),
           concurrency_(concurrency),
           timeout_(timeout),
           server_name_(server_name),
-          port_(port),
-          bindaddr_(bindaddr),
           task_queue_length_pool_(concurrency_ - 1),
           middlewares_(middlewares),
           adaptor_ctx_(adaptor_ctx)
@@ -150,11 +149,10 @@ namespace crow // NOTE: Already documented in "crow/app.h"
                   });
             }
 
-            port_ = acceptor_.local_endpoint().port();
+            port_ = acceptor_.port();
             handler_->port(port_);
 
-
-            CROW_LOG_INFO << server_name_ << " server is running at " << (handler_->ssl_used() ? "https://" : "http://") << bindaddr_ << ":" << acceptor_.local_endpoint().port() << " using " << concurrency_ << " threads";
+            CROW_LOG_INFO << server_name_ << " server is running at " << acceptor_.url_display(handler_->ssl_used()) << " using " << concurrency_ << " threads";
             CROW_LOG_INFO << "Call `app.loglevel(crow::LogLevel::Warning)` to hide Info level logs.";
 
             signals_.async_wait(
@@ -240,7 +238,7 @@ namespace crow // NOTE: Already documented in "crow/app.h"
                   is, handler_, server_name_, middlewares_,
                   get_cached_date_str_pool_[service_idx], *task_timer_pool_[service_idx], adaptor_ctx_, task_queue_length_pool_[service_idx]);
 
-                acceptor_.async_accept(
+                acceptor_.raw_acceptor().async_accept(
                   p->socket(),
                   [this, p, &is, service_idx](error_code ec) {
                       if (!ec)
@@ -273,7 +271,7 @@ namespace crow // NOTE: Already documented in "crow/app.h"
         asio::io_service io_service_;
         std::vector<detail::task_timer*> task_timer_pool_;
         std::vector<std::function<std::string()>> get_cached_date_str_pool_;
-        tcp::acceptor acceptor_;
+        Acceptor acceptor_;
         bool shutting_down_ = false;
         bool server_started_{false};
         std::condition_variable cv_started_;
@@ -288,6 +286,7 @@ namespace crow // NOTE: Already documented in "crow/app.h"
         std::string server_name_;
         uint16_t port_;
         std::string bindaddr_;
+        bool use_unix_;
         std::vector<std::atomic<unsigned int>> task_queue_length_pool_;
 
         std::chrono::milliseconds tick_interval_;

include/crow/routing.h

@@ -118,6 +118,11 @@ namespace crow // NOTE: Already documented in "crow/app.h"
             res = response(404);
             res.end();
         }
+        virtual void handle_upgrade(const request&, response& res, UnixSocketAdaptor&&)
+        {
+            res = response(404);
+            res.end();
+        }
 #ifdef CROW_ENABLE_SSL
         virtual void handle_upgrade(const request&, response& res, SSLAdaptor&&)
         {
@@ -463,6 +468,11 @@ namespace crow // NOTE: Already documented in "crow/app.h"
             max_payload_ = max_payload_override_ ? max_payload_ : app_->websocket_max_payload();
             new crow::websocket::Connection<SocketAdaptor, App>(req, std::move(adaptor), app_, max_payload_, open_handler_, message_handler_, close_handler_, error_handler_, accept_handler_);
         }
+        void handle_upgrade(const request& req, response&, UnixSocketAdaptor&& adaptor) override
+        {
+            max_payload_ = max_payload_override_ ? max_payload_ : app_->websocket_max_payload();
+            new crow::websocket::Connection<UnixSocketAdaptor, App>(req, std::move(adaptor), app_, max_payload_, open_handler_, message_handler_, close_handler_, error_handler_, accept_handler_);
+        }
 #ifdef CROW_ENABLE_SSL
         void handle_upgrade(const request& req, response&, SSLAdaptor&& adaptor) override
         {

include/crow/socket_acceptors.h

@@ -0,0 +1,54 @@
+#pragma once
+#ifndef ASIO_STANDALONE
+#define ASIO_STANDALONE
+#endif
+#include <asio.hpp>
+
+namespace crow
+{
+    using tcp = asio::ip::tcp;
+    using stream_protocol = asio::local::stream_protocol;
+
+    struct TCPAcceptor
+    {
+        using endpoint = tcp::endpoint;
+        tcp::acceptor acceptor_;
+        TCPAcceptor(asio::io_service& io_service, const endpoint& endpoint):
+          acceptor_(io_service, endpoint) {}
+
+        int16_t port() const
+        {
+            return acceptor_.local_endpoint().port();
+        }
+        std::string url_display(bool ssl_used) const
+        {
+            return (ssl_used ? "https://" : "http://") + acceptor_.local_endpoint().address().to_string() + ":" + std::to_string(acceptor_.local_endpoint().port());
+        }
+        tcp::acceptor& raw_acceptor()
+        {
+            return acceptor_;
+        }
+    };
+
+    struct UnixSocketAcceptor
+    {
+        using endpoint = stream_protocol::endpoint;
+        stream_protocol::acceptor acceptor_;
+        UnixSocketAcceptor(asio::io_service& io_service, const endpoint& endpoint):
+          acceptor_(io_service, endpoint, false) {}
+        // reuse addr must be false (https://github.com/chriskohlhoff/asio/issues/622)
+
+        int16_t port() const
+        {
+            return 0;
+        }
+        std::string url_display(bool) const
+        {
+            return acceptor_.local_endpoint().path();
+        }
+        stream_protocol::acceptor& raw_acceptor()
+        {
+            return acceptor_;
+        }
+    };
+} // namespace crow