Initial setup

CMakeLists.txt

@@ -1,7 +1,28 @@
-cmake_minimum_required(VERSION 3.0)
+cmake_minimum_required(VERSION 3.5)
+project(pica
+    VERSION 0.0.1
+    LANGUAGES CXX
+)
 
-project(pica)
+cmake_policy(SET CMP0076 NEW)
+
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+find_package(PkgConfig REQUIRED)
+pkg_check_modules(FCGI fcgi)
 
 add_executable(pica main.cpp)
+target_include_directories(pica PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})
+
+add_subdirectory(server)
+add_subdirectory(request)
+add_subdirectory(response)
+add_subdirectory(stream)
+
+target_link_libraries(pica
+    fcgi
+    fcgi++
+)
 
 install(TARGETS pica RUNTIME DESTINATION bin)

main.cpp

@@ -1,6 +1,27 @@
+#include <fcgiapp.h>
+
+#include <sys/stat.h>
+#include <sys/types.h>
+
 #include <iostream>
 
-int main(int argc, char **argv) {
-    std::cout << "Hello, world!" << std::endl;
-    return 0;
+#include "server/server.h"
+
+int main() {
+    const char* socketPath = "/run/pica/pica.sock";
+    int sockfd = FCGX_OpenSocket(socketPath, 1024);
+    if (sockfd < 0) {
+        std::cerr << "Error opening socket" << std::endl;
+        return 1;
+    }
+
+    if (chmod(socketPath, 0770) != 0) {
+        std::cerr << "Couldn't set socket permissions" << std::endl;
+        return 2;
+    }
+
+    FCGX_Init();
+
+    Server server;
+    server.run(sockfd);
 }

pica.kdev4

@@ -1,3 +0,0 @@
-[Project]
-Name=pica
-Manager=KDevCMakeManager

request/CMakeLists.txt

@@ -0,0 +1,9 @@
+set(HEADERS
+    request.h
+)
+
+set(SOURCES
+    request.cpp
+)
+
+target_sources(pica PRIVATE ${SOURCES})

request/request.cpp

@@ -0,0 +1,93 @@
+#include "request.h"
+
+constexpr static const char* GET("GET");
+
+constexpr static const char* REQUEST_METHOD("REQUEST_METHOD");
+constexpr static const char* SCRIPT_FILENAME("SCRIPT_FILENAME");
+constexpr static const char* SERVER_NAME("SERVER_NAME");
+
+Request::Request ():
+    state(State::initial),
+    raw()
+{}
+
+Request::~Request() {
+    terminate();
+}
+
+void Request::terminate() {
+    switch (state) {
+        case State::accepted:
+        case State::responded:
+            FCGX_Finish_r(&raw);
+            break;
+        default:
+            break;
+    }
+}
+
+bool Request::isGet() const {
+    if (state != State::accepted)
+        throw std::runtime_error("An attempt to read request type on a wrong request state");
+
+    std::string_view method(FCGX_GetParam(REQUEST_METHOD, raw.envp));
+    return method == GET;
+}
+
+bool Request::wait(int socketDescriptor) {
+    if (state != State::initial)
+        throw std::runtime_error("An attempt to wait for new incomming request on a wrong request state");
+
+    FCGX_Request* request = &raw;
+    FCGX_InitRequest(request, socketDescriptor, 0);
+    int rc = FCGX_Accept_r(request);
+
+    bool result = rc == 0;
+    if (result)
+        state = State::accepted;
+
+    return result;
+}
+
+OStream Request::getOutputStream() {
+    if (state != State::accepted)
+        throw std::runtime_error("An attempt to request output stream on a wrong request state");
+
+    return OStream(raw.out);
+}
+
+OStream Request::getErrorStream() {
+    if (state != State::accepted)
+        throw std::runtime_error("An attempt to request error stream on a wrong request state");
+
+    return OStream(raw.err);
+}
+
+std::string_view Request::getPath(const std::string& serverName) const {
+    if (state != State::accepted)
+        throw std::runtime_error("An attempt to request path on a wrong request state");
+
+    std::string_view path;
+    std::string_view scriptFileName(FCGX_GetParam(SCRIPT_FILENAME, raw.envp));
+    std::string::size_type snLocation = scriptFileName.find(serverName);
+    if (snLocation != std::string::npos) {
+        if (snLocation + serverName.size() < scriptFileName.size())
+            path = scriptFileName.substr(snLocation + serverName.size() + 1);
+    }
+
+    return path;
+}
+
+std::string Request::getServerName() const {
+    if (state != State::accepted)
+        throw std::runtime_error("An attempt to request server name on a wrong request state");
+
+    return FCGX_GetParam(SERVER_NAME, raw.envp);;
+}
+
+void Request::printEnvironment(std::ostream& out) {
+    char **envp = raw.envp;
+    for (int i = 0; envp[i] != nullptr; ++i) {
+        out << envp[i] << "</br>";
+    }
+}

request/request.h

@@ -0,0 +1,40 @@
+#pragma once
+
+#include <memory>
+#include <stdexcept>
+#include <string_view>
+
+#include <fcgiapp.h>
+
+#include "stream/ostream.h"
+
+class Request {
+public:
+    enum class State {
+        initial,
+        accepted,
+        responded
+    };
+
+    Request();
+    ~Request();
+    Request(const Request& other) = delete;
+    Request(Request&& other) = delete;
+    Request& operator = (const Request& other) = delete;
+    Request& operator = (Request&& other) = delete;
+
+    bool wait(int socketDescriptor);
+    void terminate();
+    bool isGet() const;
+
+    OStream getOutputStream();
+    OStream getErrorStream();
+
+    std::string_view getPath(const std::string& serverName) const;
+    std::string getServerName() const;
+    void printEnvironment(std::ostream& out);
+
+private:
+    State state;
+    FCGX_Request raw;
+};

response/CMakeLists.txt

@@ -0,0 +1,9 @@
+set(HEADERS
+    response.h
+)
+
+set(SOURCES
+    response.cpp
+)
+
+target_sources(pica PRIVATE ${SOURCES})

response/response.cpp

@@ -0,0 +1,42 @@
+#include "response.h"
+
+constexpr std::array<std::string_view, static_cast<uint8_t>(Response::Status::__size)> statusCodes = {
+    "Status: 200 OK",
+    "Status: 404 Not Found",
+    "Status: 405 Method Not Allowed",
+    "Status: 500 Internal Error"
+};
+
+constexpr std::array<std::string_view, static_cast<uint8_t>(Response::ContentType::__size)> contentTypes = {
+    "Content-type: text/html"
+};
+
+Response::Response():
+    status(Status::ok),
+    type(ContentType::text),
+    body()
+{}
+
+Response::Response(Status status):
+    status(status),
+    type(ContentType::text),
+    body()
+{}
+
+void Response::replyTo(Request& request) const {
+    // OStream out = status == Status::ok ?
+    //     request.getOutputStream() :
+    //     request.getErrorStream();
+    OStream out = request.getOutputStream();
+
+    out << statusCodes[static_cast<uint8_t>(status)];
+    if (!body.empty())
+        out << '\n'
+        << contentTypes[static_cast<uint8_t>(type)]
+        << '\n' << '\n'
+        << body;
+}
+
+void Response::setBody(const std::string& body) {
+    Response::body = body;
+}

response/response.h

@@ -0,0 +1,34 @@
+#pragma once
+
+#include <string>
+#include <array>
+#include <string_view>
+
+#include "request/request.h"
+#include "stream/ostream.h"
+
+class Response {
+public:
+    enum class Status {
+        ok,
+        notFound,
+        methodNotAllowed,
+        internalError,
+        __size
+    };
+
+    enum class ContentType {
+        text,
+        __size
+    };
+    Response();
+    Response(Status status);
+
+    void replyTo(Request& request) const;
+    void setBody(const std::string& body);
+
+private:
+    Status status;
+    ContentType type;
+    std::string body;
+};

server/CMakeLists.txt

@@ -0,0 +1,9 @@
+set(HEADERS
+    server.h
+)
+
+set(SOURCES
+    server.cpp
+)
+
+target_sources(pica PRIVATE ${SOURCES})

server/server.cpp

@@ -0,0 +1,78 @@
+#include "server.h"
+
+constexpr static const char* REQUEST_URI("REQUEST_URI");
+
+constexpr static const char* DOCUMENT_URI("DOCUMENT_URI");
+constexpr static const char* DOCUMENT_ROOT("DOCUMENT_ROOT");
+
+constexpr static const char* SCRIPT_NAME("SCRIPT_NAME");
+constexpr static const char* SCRIPT_FILENAME("SCRIPT_FILENAME");
+
+constexpr std::string_view info("info");
+constexpr std::string_view env("env");
+
+Server::Server():
+    terminating(false),
+    requestCount(0),
+    serverName(std::nullopt)
+{}
+
+Server::~Server() {}
+
+void Server::run(int socketDescriptor) {
+    while (!terminating) {
+        std::unique_ptr<Request> request = std::make_unique<Request>();
+        bool result = request->wait(socketDescriptor);
+        if (!result) {
+            std::cerr << "Error accepting a request" << std::endl;
+            return;
+        }
+        handleRequest(std::move(request));
+    }
+}
+
+void Server::handleRequest(std::unique_ptr<Request> request) {
+    ++requestCount;
+    if (!serverName) {
+        try {
+            serverName = request->getServerName();
+            std::cout << "received server name " << serverName.value() << std::endl;
+        } catch (...) {
+            std::cerr << "failed to read server name" << std::endl;
+            Response error(Response::Status::internalError);
+            error.replyTo(*request.get());
+            return;
+        }
+    }
+
+    if (!request->isGet()) {
+        static const Response methodNotAllowed(Response::Status::methodNotAllowed);
+        methodNotAllowed.replyTo(*request.get());
+        return;
+    }
+
+    try {
+        std::string_view sPath = request->getPath(serverName.value());
+
+        if (sPath == info) {
+            Response res;
+            res.setBody("Pica<br>\nVersion: 1.0.0<br>\nRequestsHandled: " + std::to_string(requestCount));
+            res.replyTo(*request.get());
+        } else if (sPath == env) {
+            std::ostringstream ss;
+            request->printEnvironment(ss);
+            Response res;
+            res.setBody(ss.str());
+            res.replyTo(*request.get());
+        } else {
+            Response notFound(Response::Status::notFound);
+            notFound.setBody(std::string("Path ") + sPath.data() + " was not found");
+            notFound.replyTo(*request.get());
+            std::cerr << "Not found: " << sPath.data() << std::endl;
+        }
+    } catch (const std::exception e) {
+        Response error(Response::Status::internalError);
+        error.setBody(e.what());
+        error.replyTo(*request.get());
+    }
+}

server/server.h

@@ -0,0 +1,35 @@
+#pragma once
+
+#include <iostream>
+#include <string>
+#include <sstream>
+#include <optional>
+#include <string_view>
+#include <vector>
+#include <memory>
+
+#include <fcgiapp.h>
+#include <fcgio.h>
+#include <stdint.h>
+
+#include "request/request.h"
+#include "response/response.h"
+
+class Server {
+public:
+    Server();
+    ~Server();
+
+    void run(int socketDescriptor);
+
+private:
+    void handleRequest(std::unique_ptr<Request> request);
+    void router(const std::vector<std::string_view>& path);
+    void printEnv(std::ostream& out, FCGX_Request& request);
+    std::string_view getPath(const FCGX_Request& request);
+
+private:
+    bool terminating;
+    uint64_t requestCount;
+    std::optional<std::string> serverName;
+};

stream/CMakeLists.txt

@@ -0,0 +1,11 @@
+set(HEADERS
+    stream.h
+    ostream.h
+)
+
+set(SOURCES
+    stream.cpp
+    ostream.cpp
+)
+
+target_sources(pica PRIVATE ${SOURCES})

stream/ostream.cpp

@@ -0,0 +1,9 @@
+#include "ostream.h"
+
+OStream::OStream(FCGX_Stream* _raw):
+    Stream(_raw),
+    std(&raw)
+{
+}
+
+OStream::~OStream() {}

stream/ostream.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#include <ios>
+
+#include "stream.h"
+
+class Request;
+
+class OStream : Stream {
+    friend class Request;
+private:
+    OStream(FCGX_Stream* raw);
+
+public:
+    ~OStream();
+
+    template <typename T>
+    OStream& operator << (const T& value) {
+        std << value;
+        return *this;
+    };
+private:
+    std::ostream std;
+};

stream/stream.cpp

@@ -0,0 +1,8 @@
+#include "stream.h"
+
+Stream::Stream(FCGX_Stream* raw):
+    raw(raw)
+{}
+
+Stream::~Stream() {
+}

stream/stream.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include <fcgio.h>
+
+class Stream {
+protected:
+    Stream(FCGX_Stream* raw);
+    Stream(const Stream& other) = delete;
+    Stream(Stream&& other) = delete;
+    Stream& operator = (const Stream& other) = delete;
+    Stream& operator = (Stream&& other) = delete;
+    virtual ~Stream();
+
+public:
+
+protected:
+    fcgi_streambuf raw;
+};