gem-graph-server/src/server.c

//=-------------------------------------------------------------------------=//
//  Server management module                                                 //
//                                                                           //
//  Copyright © 2021 The Gem-graph Project                                   //
//                                                                           //
//  This file is part of gem-graph.                                          //
//                                                                           //
//  This program is free software: you can redistribute it and/or modify     //
//  it under the terms of the GNU Affero General Public License as           //
//  published by the Free Software Foundation, either version 3 of the       //
//  License, or (at your option) any later version.                          //
//                                                                           //
//  This program is distributed in the hope that it will be useful,          //
//  but WITHOUT ANY WARRANTY; without even the implied warranty of           //
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the            //
//  GNU Affero General Public License for more details.                      //
//                                                                           //
//  You should have received a copy of the GNU Affero General Public License //
//  along with this program.  If not, see <https://www.gnu.org/licenses/>.   //
//=-------------------------------------------------------------------------=//

#include "../include/base.h"
#include "../include/cmds.h"

#include <sys/socket.h>
#include <arpa/inet.h>

static void *serverMain(void *server);

/* -------------------------------------------------------------------------- */

// -------------------------------------------------------------------------- //
// Scheduler init function                                                    //
// -------------------------------------------------------------------------- //
void ServerInit(Server_t *scheduler)
{
    scheduler->id = (pthread_t*) calloc(1, sizeof(pthread_t));
    pthread_create(scheduler->id, NULL, serverMain, scheduler);
}

// -------------------------------------------------------------------------- //
// Socket init function                                                       //
// -------------------------------------------------------------------------- //
static inline int createSocket(void)
{
    int newSocket;
    printLog("Create the socket\n");
    newSocket = socket(AF_INET, SOCK_STREAM, 0);
    return newSocket;
}

// -------------------------------------------------------------------------- //
// Soecket binding function                                                   //
// -------------------------------------------------------------------------- //
static inline int bindSocket(int newSocket)
{
    int effectiveSocket = -1;
    int clientPort = 90190;
    struct sockaddr_in remote = {0};

    // Internet address family
    remote.sin_family = AF_INET;

    // Any incoming interface
    remote.sin_addr.s_addr = htonl(INADDR_ANY);
    remote.sin_port = htons(clientPort); // Local port
    effectiveSocket = bind(newSocket,(struct sockaddr*)&remote,sizeof(remote));

    return effectiveSocket;
}

// -------------------------------------------------------------------------- //
// Server main function                                                       //
// -------------------------------------------------------------------------- //
static void *serverMain(void *server)
{
    Server_t *args;
    int socketDescriptor, effectiveSocket, clientRequestLength;
    struct sockaddr_in client;
    char clientRequest[255]= {0};
    char serverAnswer[255] = {0};
    char **argv = NULL;
    char *commandReturn;
    int tokenIndex;

    // Get args
    args = (Server_t*) server;
    printLog("Server #%lu online\n", *args->id);

    //Create socket
    socketDescriptor = createSocket();

    if (socketDescriptor < 0) {
        printLog("Could not create socket\n");
        return NULL;
    }
    printLog("Socket created\n");

    //Bind
    if( bindSocket(socketDescriptor) < 0) {
        //print the error serverAnswer
        printLog("Socket bind failed\n");
        return NULL;
    }

    printLog("Socket bind succeeded\n");

    //Listen
    listen(socketDescriptor, 3);

    //Accept and incoming connection
    while(!args->pleaseStop) {
        printLog("Waiting for incoming connections...\n");
        clientRequestLength = sizeof(struct sockaddr_in);

        //accept connection from an incoming client
        effectiveSocket = accept(socketDescriptor,(struct sockaddr *)&client,(socklen_t*)&clientRequestLength);

        if (effectiveSocket < 0) {
            printLog("Acceptation failed\n");
            return NULL;
        }

        printLog("Connection accepted\n");

        memset(clientRequest, '\0', sizeof(clientRequest));
        strcpy(serverAnswer,"Invalid command\0");

        //Receive REQUEST from client
        if (recv(effectiveSocket, clientRequest, 200, 0) < 0) {
            printLog("Reception failed");
            break;
        }

        printLog("Client request : %s\n",clientRequest);

        // get args in an array
        tokenIndex = 0;
        argv = (char**) realloc(argv, 1 * sizeof(char*));
        argv[0] = strtok(clientRequest, " ");
        while (argv[tokenIndex]) {
            tokenIndex++;
            argv = (char**) realloc(argv, (tokenIndex+1) * sizeof(char*));
            argv[tokenIndex] = strtok(NULL, " ");
        }

        // test first arg to find command in cmdList
        for (int i = 0; i < LEN(cmdList); i++) {
            if (strcmp(cmdList[i].name, argv[0]) == 0) {
                commandReturn = cmdList[i].execute(argv, args);
                strcpy(serverAnswer, commandReturn);
                free(commandReturn);
            }
        }

        // REPLY to client
        if (send(effectiveSocket, serverAnswer, strlen(serverAnswer), 0) < 0) {
            printLog("Send failed\n");
            return NULL;
        }

        close(effectiveSocket);
    }

    free(argv);
    printLog("Server #%lu offline\n", *args->id);

    return NULL;
}