for a classwork i've to close all opened sockets after client sends "NEWPORT " and assign the "n-port" to a new socket, and from that moment i've to use the socket created for the new incoming connections, but when i try to connect to new one the perror function on client side says me "Connection refused".
Server code
#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<string.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<arpa/inet.h>
#define MAX_SIZE 512
void manage_connections(int fds,struct sockaddr_in serv_addr, struct sockaddr_in cl_addr, socklen_t cl_len);
int main(int argc, char* argv[]){
struct sockaddr_in serv_addr, cl_addr;
socklen_t cl_len;
int fds=0;
serv_addr.sin_family = AF_INET;
serv_addr.sin_port = htons(5200);
serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
fds = socket(AF_INET, SOCK_STREAM, 0);
if(fds<0){
perror("Socket error");
exit(-1);
}
if(bind(fds,(struct sockaddr*)&serv_addr, sizeof(serv_addr))<0){
perror("Bind error");
exit(-1);
}
if((listen(fds,5))<0){
perror("Listen error");
exit(-1);
}
manage_connections(fds,serv_addr, cl_addr, cl_len);
close(fds);
return 0;
}
void manage_connections(int fds,struct sockaddr_in serv_addr, struct sockaddr_in cl_addr, socklen_t cl_len){
char buffer[MAX_SIZE], cl_ip[MAX_SIZE], cl_port[MAX_SIZE], cmd_np[MAX_SIZE], cmd_np_n[MAX_SIZE], cmd_np_str[MAX_SIZE], nport[MAX_SIZE];
int i=0, port=0,fdc=0, nfds;
struct sockaddr_in nserv_addr;
while(1){
cl_len = sizeof(cl_addr);
fdc = accept(fds, (struct sockaddr*)&cl_addr, &cl_len);
if(fdc<0){
perror("Accept error");
exit(-1);
}
do{
for(i=0;i<MAX_SIZE;i++){
buffer[i]=0;
cl_ip[i]=0;
cl_port[i]=0;
cmd_np[i]=0;
cmd_np_n[i]=0;
cmd_np_str[i]=0;
nport[i]=0;
}
read(fdc,buffer, MAX_SIZE);
if(strcmp(buffer,"MYIP")==0){
strcat(cl_ip,inet_ntoa(cl_addr.sin_addr));
write(fdc,cl_ip,strlen(cl_ip));
} else if(strcmp(buffer,"MYPORT")==0){
sprintf(cl_port,"%d", (int)htons(cl_addr.sin_port));
write(fdc, cl_port, strlen(cl_port));
}else{
sscanf(buffer, "%s %d", cmd_np, &port);
sprintf(nport, "%d", port);
if(strcmp(cmd_np,"NEWPORT")==0){
strcat(cmd_np_str, "ACK ");
strcat(cmd_np_str, nport);
write(fdc, cmd_np_str,strlen(cmd_np_str));
close(fds);
close(fdc);
nserv_addr.sin_family=AF_INET;
nserv_addr.sin_port = htons(port);
nserv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
nfds = socket(AF_INET, SOCK_STREAM,0);
if(nfds<0){
perror("New socket error");
exit(-1);
}
if((bind(nfds,(struct sockaddr*)&nserv_addr,sizeof(nserv_addr)))<0){
perror("New bind error");
exit(-1);
}
if((listen(nfds,5))<0){
perror("New listen error");
exit(-1);
}
manage_connections(nfds,nserv_addr, cl_addr, cl_len);
}
}
}while(strcmp(cmd_np,"NEWPORT")!=0);
close(fdc);
}
}
Client code
#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<string.h>
#include<arpa/inet.h>
#include<sys/types.h>
#include<sys/socket.h>
#define MAX_SIZE 512
int main(int argc, char* argv[]){
struct sockaddr_in cl_addr;
int fdc=0,len=0, res_len=0,i=0;
char buffer[MAX_SIZE];
cl_addr.sin_family = AF_INET;
cl_addr.sin_port = htons(5200);
inet_aton("192.168.10.128",&cl_addr.sin_addr);
fdc = socket(AF_INET, SOCK_STREAM,0);
if(fdc<0){
perror("Accept error");
exit(-1);
}
if((connect(fdc, (struct sockaddr*)&cl_addr, sizeof(cl_addr)))<0){
perror("Connect error");
exit(-1);
}
while(1){
write(1, "Inserire uno tra i comandi MYIP, MYPORT, NEWPORT:\n", strlen("Inserire uno tra i comandi MYIP, MYPORT, NEWPORT:\n"));
len = read(1, buffer, MAX_SIZE);
buffer[len-1] = '\0';
write(fdc, buffer, strlen(buffer)+1);
for(i=0;i<MAX_SIZE;i++)
buffer[i]=0;
res_len = read(fdc,buffer,MAX_SIZE);
write(1,"\nResponso: ",strlen("\nResponso: "));
write(1, buffer, res_len);
write(1,"\n",strlen("\n"));
}
close(fdc);
return 0;
}
