send information to forked process with threads - c

Question

I have 2 programs, a client and a server, the client can send data to the server, and I want to send all the new data received on the server from one client to the other connected clients with a thread, each connected client has a child process in the server that receives the data, here is an illustration of what I want to do.
server.c :
int main(int argc, char const *argv[]) {
Liste *ListeTache;
int sh_id;
int i,j;
size_t sizeMatrix = sizeof_dm(30,100,sizeof(char));
ListeTache=malloc(sizeof(Liste));
init_Liste(ListeTache);
key_t keyfile = ftok("keyFileIpc.txt",10);
if((sh_id = shmget(keyfile,sizeof(Liste),IPC_CREAT|0666)) == -1) {
perror("shmget");
exit(1);
}
if ((ListeTache = shmat(sh_id, NULL, 0)) == (void *) -1) {
perror("shmat");
exit(1);
}
init_Liste(ListeTache);
printSharedMem(ListeTache->s);
//creation de la socket pour le TCP
int sock = socket(AF_INET, SOCK_STREAM, 0);
if(sock == -1) {
perror("socket error\n");
exit(errno);
}
struct sockaddr_in sin = { 0 };
sin.sin_addr.s_addr = htonl(INADDR_ANY);
sin.sin_family = PF_INET;
sin.sin_port = htons(31470);
if(bind (sock, (struct sockaddr *) &sin, sizeof sin) == -1) {
perror("bind()");
exit(errno);
}
if(listen(sock, 3) == -1) {
perror("listen error\n");
exit(errno);
}
struct sockaddr_in csin = { 0 };
int idSock;
socklen_t lg = sizeof(struct sockaddr_in);
char msg[100];
do {
if ((idSock = accept(sock, (struct sockaddr *) &csin, &lg)) == -1) {
perror("accept error\n");
exit(errno);
}
if (!fork()) {
close(sock);
printSharedMem(ListeTache->s);
printf("i'm here\n");
// we send here the initial data
if(send(idSock, ListeTache, sizeof(Liste), 0) < 0) {
perror("send()");
exit(errno);
}
pthread_t idThread;
do {
if(recv(idSock, &paramsReq, sizeof(paramsReq), 0) < 0) {
perror("paramsReq :recv error\n");
exit(errno);
}
//if recv something from a client then i want to send the change to all the others here
}
else
{
close(idSock);
}
} while (1);
free(ListeTache);
ListeTache=NULL;
shmctl(sh_id, IPC_RMID, NULL);
return 0;
}
client.c
void *listenServ (void *arg) {
paramsListenServ params = *((paramsListenServ *) arg);
paramsRequest paramsReq;
do {
if(recv(params.sockId, &paramsReq, sizeof(paramsReq), 0) < 0) {
perror("recv error\n");
exit(errno);
}
printf("%s \n", paramsReq.requestType);
if (!strcmp(paramsReq.requestType, "addRequest")) {
strcpy(&params.s[paramsReq.taskToModify*100], paramsReq.taskText);
printSharedMemo(params.s);
}
else if (!strcmp(paramsReq.requestType, "swapRequest")) {
char firstTask[100];
strcpy(firstTask, &params.s[paramsReq.tasksToSwap.firstTask*100]);
strcpy(&params.s[paramsReq.tasksToSwap.firstTask*100], &params.s[paramsReq.tasksToSwap.secondTask*100]);
strcpy(&params.s[paramsReq.tasksToSwap.secondTask*100], firstTask);
printSharedMemo(params.s);
}
else if (!strcmp(paramsReq.requestType, "modifyRequest")) {
strcpy(&params.s[paramsReq.taskToModify*100], paramsReq.taskText);
printSharedMemo(params.s);
}
else if (!strcmp(paramsReq.requestType, "deleteRequest")) {
int i = paramsReq.taskToModify;
while (i < 29 && strlen(&params.s[i * 100]) != 0) {
strcpy(&params.s[i*100], &params.s[(i + 1)*100]);
i++;
}
strcpy(&params.s[(paramsReq.head - 1)*100], "");
printSharedMemo(params.s);
}
/*printf("Message reçu du serveur : %s\n", msg);
memset(msg,0, sizeof msg);*/
} while (1);
pthread_exit(NULL);
}
int main(int argc, char const *argv[]) {
//creation d'un socket ppour le TCP
int sock = socket(AF_INET, SOCK_STREAM, 0);
Liste *ListeTache;
ListeTache=malloc(sizeof(Liste));
init_Liste(ListeTache);
int j;
if(sock == -1) {
perror("socket()");
exit(errno);
}
//initialisation de la structure de donné
struct sockaddr_in sin = { 0 };
sin.sin_family = PF_INET;
sin.sin_addr.s_addr = inet_addr("127.0.0.1");
sin.sin_port = htons((short)31470);
//connect to the server
if(connect(sock,(struct sockaddr *) & sin, sizeof(struct sockaddr_in)) == -1) {
perror("connect()");
exit(errno);
}
// we receive the initial data
if(recv(sock,ListeTache,sizeof(Liste), 0) < 0) {
perror("main :recv error\n");
exit(errno);
}
printSharedMemo(ListeTache->s);
pthread_t idThread;
paramsListenServ params;
params.s=ListeTache->s;
params.sockId = sock;
// this thread listen to the send that is in the server
if(pthread_create(&idThread, NULL, listenServ, &params) != 0)
perror("pthread_create");
do {
//do changes
//we send the new data to the server
if(send(sock, &paramsReq, sizeof(paramsReq), 0) < 0) {
perror("send()");
exit(errno);
}
}
}
} while(1<=choice && choice<=4);
close(sock);
printf("La connexion avec le serveur a bien été fermée ! \n");
return 0;
}
My question is, if I use a thread and put it in a fork, how can the thread get the data sent from one client because the socket change from one client to another?