SERVIDOR

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>



#define MAXBUFFER 512
#define PUERTO 4950

int main(int argc, char * argv[]){


    int sd, n_sd;
    struct sockaddr_in server,cliente;
    socklen_t longCliente = sizeof(cliente);
    char buffer[MAXBUFFER];

    if((sd=socket(PF_INET,SOCK_STREAM,0)) < 0){
        perror("socket");
        exit(1);
    }

    memset(&server,0,sizeof(server));
    server.sin_family = AF_INET;
    server.sin_port = htons(PUERTO);
    server.sin_addr.s_addr = INADDR_ANY;

    if(bind(sd,(struct sockaddr *)&server, sizeof(server)) < 0){
        perror("bind");
        exit(1);
    }

    if(listen(sd,5) < 0){
        perror("listen");
        exit(1);
    }

    while(1){

        printf("Esperando conexión...\n");

        n_sd = accept(sd,(struct sockaddr *)&cliente, &longCliente);
        if(n_sd < 0){
            perror("accept");
            close(sd);
            exit(1);
        }


            FILE * file = fopen("claves.txt","r");
            if(file == NULL){
                perror("fopen");
                close(n_sd);
                close(sd);
                exit(1);
            }

        uint32_t longBigEndian;

        if((read(n_sd,&longBigEndian,sizeof(uint32_t))) != sizeof(uint32_t)){
            perror("longBigEndian");
            fclose(file);
            close(n_sd);
            close(sd);
            exit(1);
        }

        int longitud = ntohl(longBigEndian);

        if((read(n_sd,buffer,longitud)) != longitud){
            perror("buffer");
            fclose(file);
            close(n_sd);
            close(sd);
            exit(1);
        }

        buffer[longitud] = '\0';

        char linea[MAXBUFFER];
        int encontrado = 0;
        char * user;
        char * pass;
        uint32_t cero = htonl(0);
        uint32_t m_uno = htonl(-1);

        while(fgets(linea,MAXBUFFER-1,file) != NULL){
            linea[strlen(linea)-1] = '\0';
            char * arroba = strstr(linea, "@");
            *arroba = '\0';
            user = linea;
            pass = arroba+1;

            if(strcmp(buffer,user) == 0){
                encontrado = 1;
                break;
            }
        }
        printf("%s\n",user);
        printf("%s\n",pass );
        if(encontrado == 1){
            int encontrado_pass = 0;
            if(write(n_sd,&cero,sizeof(uint32_t)) != sizeof(uint32_t)){
                perror("write");
                fclose(file);
                close(n_sd);
                close(sd);
                exit(1);
            }

            //Contraseña

            if((read(n_sd,&longBigEndian,sizeof(uint32_t))) != sizeof(uint32_t)){
                perror("longBigEndian");
                fclose(file);
                close(n_sd);
                close(sd);
                exit(1);
            }

            int longitud = ntohl(longBigEndian);

            if((read(n_sd,buffer,longitud)) != longitud){
                perror("buffer");
                fclose(file);
                close(n_sd);
                close(sd);
                exit(1);
            }

            if(strcmp(buffer,pass) == 0){
                encontrado_pass = 1;
            }

            if(encontrado_pass == 1){
                if(write(n_sd,&cero,sizeof(uint32_t)) != sizeof(uint32_t)){
                    perror("write");
                    fclose(file);
                    close(n_sd);
                    close(sd);
                    exit(1);
                }
            }else{

                if(write(n_sd,&m_uno,sizeof(uint32_t)) != sizeof(uint32_t)){
                    perror("write");
                    fclose(file);
                    close(n_sd);
                    close(sd);
                    exit(1);
                }
            }

        }else{

            if(write(n_sd,&m_uno,sizeof(uint32_t)) != sizeof(uint32_t)){
                perror("write");
                fclose(file);
                close(n_sd);
                close(sd);
                exit(1);
            }
        }
        fclose(file);
        close(n_sd);
    }

    close(sd);


return 0;

}