fork() Server in C doesnt respond to client - c

Question

I wrote a login server with fork in C using txt file as a database. I found a problem when im trying to use my client more than one time, that sometimes its bugs, and doesnt print anything in the console.
Here is the server code:
#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>
#include <arpa/inet.h>
FILE* fp;
int main() {
int server_socket;
socklen_t addr_size;
struct sockaddr_in server_address;
struct sockaddr_in client_address;
char buffor[1024], info[21], pass[21], decision[10];
pid_t childpid;
fp = fopen("baza.txt", "a+");
server_socket = socket(AF_INET, SOCK_STREAM,0);
if(server_socket < 0){
printf("Błąd tworzenia socketu.\n");
exit(EXIT_FAILURE);
}
printf("Utworzono socket\n");
memset(&server_address,'\0',sizeof(server_socket));
server_address.sin_family = AF_INET;
server_address.sin_port = htons(9002);
server_address.sin_addr.s_addr = inet_addr("127.0.0.1");
if ((bind(server_socket, (struct sockaddr*) &server_address, sizeof(server_address)))<0){
printf("Błąd przy przybijaniu gniazda");
exit(EXIT_FAILURE);
}
listen(server_socket, 20);
while(1){
rewind(fp);
int client_socket = accept(server_socket, (struct sockaddr*)&client_address, &addr_size);
printf("Połączenie od IP: %s i portu: %d\n",inet_ntoa(client_address.sin_addr),ntohs(client_address.sin_port));
if ((childpid = fork()) == 0){
bzero(&decision,sizeof(decision));
bzero(&buffor,sizeof(buffor));
bzero(&pass,sizeof(pass));
recv(client_socket,&decision,sizeof(decision),0);
FILE *local_fp = fdopen(fileno(fp),"a+");
int foundlog = 0;
int foundrej = 0;
char line[100];
if(strcmp(decision,"log")==0){
rewind(local_fp);
recv(client_socket,&buffor,sizeof(buffor),0);
strcat(buffor,"login");
while(fscanf(local_fp,"%100s",info)==1){
if(strcmp(info, buffor)==0){
send(client_socket,"Znaleziono login",strlen("znaleziono login"),0);
foundlog = 1;
}
}
if (foundlog==0){
send(client_socket,"Nie ma takiego loginu", strlen("Nie ma takiego loginu"),0);
exit(EXIT_FAILURE);
}
rewind(local_fp);
if (foundlog==1){
recv(client_socket,&pass,sizeof(pass),0);
strcat(buffor,"\t");
strcat(buffor,pass);
while(fgets(line,100,local_fp)!=NULL){
if(strstr(line,buffor)!=NULL){
send(client_socket,"Zalogowano",strlen("Zalogowano"),0);
foundlog=2;
}
}
}
if (foundlog==1){
send(client_socket,"Hasło nie pasuje do nazwy użytkownika",strlen("Hasło nie pasuje do nazwy użytkownika"),0);
exit(EXIT_FAILURE);
}
}
if(strcmp(decision,"rej")==0){
recv(client_socket,&buffor,sizeof(buffor),0);
strcat(buffor,"login");
while(fscanf(local_fp,"%100s",info)==1){
if(strcmp(info, buffor)==0){
send(client_socket,"Taki login już istnieje",strlen("Taki login już istnieje"),0);
exit(EXIT_FAILURE);
}
}
send(client_socket,"Podany login jest wolny",strlen("Podany login jest wolny"),0);
recv(client_socket,&pass,sizeof(pass),0);
strcat(buffor,"\t");
strcat(buffor,pass);
rewind(local_fp);
fprintf(local_fp,"%s\n",buffor);
send(client_socket,"Zarejestrowano nowego użytkownika",strlen("Zarejestrowano nowego użytkownika"),0);
}
fclose(local_fp);
close(client_socket);
}
close(client_socket);
}
fclose(fp);
return 0;
}
And client
#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>
#include <arpa/inet.h>
int main(){
int client_socket;
char login[20], info[20], ans[1024], pass[20];
client_socket = socket(AF_INET, SOCK_STREAM, 0);
struct sockaddr_in server_address;
server_address.sin_family = AF_INET;
server_address.sin_port = htons(9002);
server_address.sin_addr.s_addr = INADDR_ANY;
system("clear");
int status = connect(client_socket, (struct sockaddr *) &server_address, sizeof(server_address));
if (status == -1){
printf("Nie udało się połączyć do serwera\n");
exit(EXIT_FAILURE);
}
bzero(&login,sizeof(login));
bzero(&ans,sizeof(ans));
bzero(&info,sizeof(info));
printf("--------Witaj na serwerze--------\n");
printf("Wybierz operację\n");
printf("1. Rejestracja\n");
printf("2. Logowanie\n");
scanf("%s",info);
if((strcmp(info, "logowanie")) == 0 || (strcmp(info,"2")) == 0){
send(client_socket,"log",strlen("log"),0);
system("clear");
printf("Wybrano zalogowanie\n");
printf("Login: ");
scanf("%s",login);
if((send(client_socket,&login,sizeof(login),0))<0){
printf("Błąd przy wysyłaniu\n");
}
if((recv(client_socket,&ans,sizeof(ans),0))<0){
printf("Błąd przy odbieraniu\n");
}
printf("%s\n",ans);
bzero(&ans,sizeof(ans));
printf("Podaj hasło: ");
scanf("%s",pass);
send(client_socket,&pass,sizeof(pass),0);
recv(client_socket,&ans,sizeof(ans),0);
printf("Odpowiedź z serwera: %s\n",ans);
}
if((strcmp(info, "rejestracja")) == 0 || (strcmp(info,"1")) == 0){
send(client_socket,"rej",strlen("rej"),0);
system("clear");
printf("Wybrano tworzenie nowego użytkownika\n");
printf("Podaj swój login:");
scanf("%s",login);
if((send(client_socket,&login,sizeof(login),0))<0){
printf("Błąd przy wysyłaniu\n");
}
if((recv(client_socket,&ans,sizeof(ans),0))<0){
printf("Błąd przy odbieraniu\n");
}
printf("%s\n",ans);
printf("Podaj swoje hasło:");
scanf("%s",pass);
send(client_socket,&pass,sizeof(pass),0);
recv(client_socket,&ans,sizeof(ans),0);
printf("Odpowiedź z serwera: %s\n",ans);
}
return 0;
}
And output of the terminal
the database looks like this
macieklogin 123
kubalogin 123
kacperlogin 1234
I have tried rewriting the client and server but it didnt help at all