C chat with sockets and thread
sábado, junho 28th, 2008 I developed a chat server in the C language and Python language
The chat written in Python is posted here. Now I developed the chat using the C sockets and threads.
The code developed in C follows the same principles of the code in Python.
In C had to develop a double linked list to store the file descriptor of the socket, user name and nickname.
This code was developed to the discipline of Distributed Systems.
# # This program is free software; you can redistribute it and/or modify # #it under the terms of the GNU General Public License as published by # #the Free Software Foundation; version 2 of the License. # # 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 General Public License for more details. # # # #author: Marlon Petry # #Date: 2008/04/30 # #Function: Chat server in C sockets threads # # #include#include #include #include #include #include #include #include #include #include #include #include #include /* for FIONREAD (sigh) */ #include #include #include “listaDDE.h” #include #define MYPORT 5800 // the port users will be connecting to #define BACKLOG 10 // how many pending connections queue will hold #define MAXLINE 1024 #define NUM_THREADS 50 fd_set rmask; pthread_mutex_t mutexsum; pthread_mutex_t mutexLogin; int fd_max; int maxfds; int sockfd; fd_set read_fds; fd_set master; nodo *root = NULL; static int read_cnt; static char *read_ptr; static char read_buf[MAXLINE]; static void *sendMensagem(void *arg); void sigchld_handler(int s); static void *sendALL(char msg[],int soks); static void *sendMensagem(void *arg); static void *newClientConnect(int arg); void sigchld_handler(int s) { while(waitpid(-1, NULL, WNOHANG) > 0); } void *sendALL(char msg[],int soks) { nodo *aux = getFirst(); while(aux != NULL) { int soc =aux->socket; if(soc != soks) { if(write(soc, msg, strlen(msg)) == -1) perror(”send”); printf(”send %s %s\n”,msg,aux->nick); } aux = aux->prox; } } void *sendMensagem(void *arg) { char *buff; int fd = (*(int *) arg); int nbytes; char tmp[5000]; printf(”\nthread call %d”,fd); newClientConnect(fd); printf(”\n entry LOOP\n”); nodo *cliente = busca(fd); while(1) { buff = (char *) calloc( MAXLINE,sizeof(char)); if(FD_ISSET(fd,&master)) { nbytes = recv(fd,buff, MAXLINE -1 , 0); if(nbytes > 1) { if(!tmp) { perror(”alocation:”); exit(-1); } strcat(tmp, cliente->nick); strcat(tmp, ” >> “); strcat(tmp, buff); sendALL(tmp,fd); } else { if (nbytes == 0) { printf (”servidor: socket %d desligado\n”, fd); } else { perror (”recv”); } close (fd); // BYE!! FD_CLR( fd , &master); removi(getFirst(),fd); pthread_exit(NULL); } } free(buff); } } static void *newClientConnect(int arg) { int fd = arg; pthread_t tid; struct sockaddr_in their_addr; char welcome[] = “Welcome Chat SistDistribuidos 0.1 \n”; char msg1[] = “Login: “; char msg2[] = “NickName: “; char nome[100]; char nick[100]; int nbytes; socklen_t sin_size; pthread_mutex_lock (&mutexLogin); printf(”\naccept \n”); if (write(fd, welcome, sizeof welcome - 1) != sizeof welcome - 1) { perror(”write:”); exit(1); } printf(”write %s \n”,welcome); usleep(1000); if (write(fd, msg1, strlen(msg1)) != strlen(msg1)) { perror(”write:”); exit(1); } printf(”write %s \n”,msg1); usleep(1000); if ((nbytes = recv(fd, nome, 100,0)) < 0) { perror("read:"); exit(1); return; } nome[nbytes -1] = '\0'; printf("Read %d %s\n",strlen(nome),nome); usleep(1000); if (write(fd, msg2, sizeof msg2 - 1) != sizeof msg2 - 1) { perror("write:"); exit(1); } if ((nbytes =recv(fd, nick, 100,0)) < 0) { perror("read:"); exit(1); } nick[nbytes-1]='\0'; printf("Read %d %s\n",strlen(nick),nick); inseri(&root,fd,nome,nick, inet_ntoa(their_addr.sin_addr)); FD_SET(fd, &master); /* listen to this socket too */ printf("end welcome \n"); pthread_mutex_unlock (&mutexLogin); } int main(void) { // listen on sock_fd, new connection on new_fd int j,new_fd; struct timeval waitd; int nbytes; char buf[256]; int fd_max; //numero maximo de descritores struct sockaddr_in my_addr; // my address information struct sockaddr_in their_addr; // connector's address information socklen_t sin_size; struct sigaction sa; int yes=1; FD_ZERO(&master); FD_ZERO(&read_fds); pthread_mutex_init(&mutexsum, NULL); pthread_mutex_init(&mutexLogin,NULL); if ((sockfd = socket(PF_INET, SOCK_STREAM, 0)) == -1) { perror("socket"); exit(1); } if ( setsockopt ( sockfd , SOL_SOCKET , SO_REUSEADDR , &yes , sizeof ( int ) ) == -1 ) { perror ( " setsockopt " ); exit ( 1 ); } my_addr.sin_family = AF_INET; // host byte order my_addr.sin_port = htons(MYPORT); // short, network byte order my_addr.sin_addr.s_addr = INADDR_ANY; // automatically fill with my IP memset(my_addr.sin_zero, '\0', sizeof my_addr.sin_zero); if (bind(sockfd, (struct sockaddr *)&my_addr, sizeof my_addr) == -1) { perror("bind"); exit(1); } if (listen(sockfd, BACKLOG) == -1) { perror("listen"); exit(1); } FD_SET(sockfd, &master); fd_max = sockfd; int rc =0; int i = 0; int ret; int fd; waitd.tv_sec = 1; waitd.tv_usec = 0; while(1) { read_fds = master; if (select (fd_max+1, &read_fds, NULL, NULL, NULL)== -1) { perror ("select"); exit(1); } int addrlen = sizeof (their_addr); if (( new_fd = accept(sockfd,&their_addr,&addrlen)) == -1) { perror ("accept"); } else { FD_SET ( new_fd , &master); printf ("server : new connection %s socket %d\n", inet_ntoa (their_addr.sin_addr),new_fd); pthread_t tred; rc = pthread_create( &tred, NULL,sendMensagem, (void *) &new_fd); if (rc){ printf("ERROR; return code from pthread_create() is %d\n", rc); exit(-1); } } } pthread_mutex_destroy(&mutexsum); pthread_mutex_destroy(&mutexLogin); return 0; }
Header Double Linked List name ListaDDE.h
# #!/usr/bin/env python # # -*- coding: iso-8859-1 -*- # # This program is free software; you can redistribute it and/or modify # #it under the terms of the GNU General Public License as published by # #the Free Software Foundation; version 2 of the License. # # 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 General Public License for more details. # # # #author: Marlon Petry # # #include#include #include #define MAXBUFFER 2048 typedef struct cel { int socket; char nome[50]; char nick[50]; char host[50]; char buff[MAXBUFFER]; struct cel *ante; struct cel *prox; }nodo; nodo *getFirst(); nodo *getLast(); void inseri(nodo **root, int socket,char nome[],char nick[],char host[]); void removi(nodo *root, int socket); void print (nodo *ini);
Implementation Double Linked List without use global variable
# #!/usr/bin/env python # # -*- coding: iso-8859-1 -*- # # This program is free software; you can redistribute it and/or modify # #it under the terms of the GNU General Public License as published by # #the Free Software Foundation; version 2 of the License. # # 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 General Public License for more details. # # # #author: Marlon Petry # #Date: 2008/04/30 #include#include #include #include “listaDDE.h” nodo *first = NULL, *last = NULL; nodo *getFirst() { printf(”call getFirst()\n”); return first; } nodo *getLast() { return last; } void inseri(nodo **root, int socket, char nome[],char nick[],char host[]) { nodo *aux; //primeira inserção if(*root == NULL) { *root = (nodo *) malloc(sizeof (nodo)); if(*root == NULL) { perror(”erro de alocação\n”); } (*root)->socket = socket; strcpy((*root)->nome , nome); strcpy((*root)->nick , nick); strcpy((*root)->host , host); (*root)->prox = NULL; (*root)->ante = NULL; first = (*root); last = first; } else { aux = (nodo *) malloc(sizeof (nodo)); if(aux == NULL) { perror(”erro de alocação\n”); } aux->socket = socket; strcpy(aux->nome , nome); strcpy(aux->nick , nick); strcpy(aux->host , host); aux->ante =last; aux->prox = NULL; last->prox = aux; last = aux; *root = last; } } void removi(nodo *primeiro,int dado) { nodo *aux = primeiro; while(aux != NULL) { if(dado == aux->socket && aux == first) //Remove first element { if(aux->prox != NULL) { printf(”!= null\n”); aux->prox->ante = NULL; first = aux->prox; } else { printf(”null\n”); free(first); break; } } else if(dado == aux->socket && aux->prox == NULL) //remove last { aux->ante->prox = NULL; last = aux->ante; free(aux); break; } else if(dado == aux->socket && aux->prox != NULL && aux->ante !=NULL) //remove middle { aux->ante->prox = aux->prox; aux->prox->ante = aux->ante; free(aux); break; } aux = aux->prox; } } void print (nodo *ini) { nodo *p = first; while(p != NULL) { printf (”socket %d cliente %s\n”, p->socket,p->nome); p = p->prox; } } nodo *busca (int key) { nodo *p = getFirst(); int flag = 0; while(p != NULL) { if(p->socket == key) { return p; } p = p->prox; } return NULL; }
In order to compile this code together use the follow command
gcc -o chatserver server.c listaDDE.c -lpthread
Using
On the server
./chatserver
On the client
telnet ipServer 5800
Digg if you like it:
Development of a chat with the C sockets and Threads
