C socket : connect error - invalid argument - c

Question

I made a simple Process-based parallel socket program.
My client code reaches the connect part and throws an Invalid argument error, and my server doesn't ouput anything. just cursor...
I split the terminal in two to run the code.
I run the code with:
gcc -o p-server p-server.c -Wall
./p-server
gcc -o p-client p-client.c -Wall
The output is
[C] Connecting...
[C] Can't connect to a Server: Invalid argument
p-server.c
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/types.h>
//#include <sys/wait.h>
#define BUFFSIZE 4096
#define SERVERPORT 7799
int main(void){
int i, j, s_sock, c_sock;
struct sockaddr_in server_addr, client_addr;
socklen_t c_addr_size;
char buf[BUFFSIZE] = {0};
char hello[] = "Hello~ I am Server!\n";
//int option = 1;
//setsockopt(s_sock, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
bzero(&server_addr, sizeof(server_addr));
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(SERVERPORT);
server_addr.sin_addr.s_addr = inet_addr("10.0.0.131");
s_sock = socket(AF_INET, SOCK_STREAM, 0);
if (bind(s_sock, (struct sockaddr *) &server_addr, sizeof(server_addr)) == -1) {
perror("[S] Can't bind a socket");
exit(1);
}
if(listen(s_sock, 5)) {
perror("[S] Can't listen");
exit(1);
}
c_addr_size = sizeof(client_addr);
for ( i=0; i<3; i++) {
if ((c_sock = accept(s_sock, (struct sockaddr *) &client_addr, sizeof(client_addr))) == -1 ){
perror("[S] Can't accept a connection");
exit(1);
}
printf("[S] Connected: client IP addr=%s port=%d\n", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));
//fork
switch(fork()){
case 0:
close(s_sock);
//1. say hello to client
if(send(c_sock, hello, sizeof(hello)+1, 0) == -1) {
perror("[S] Can't send message");
exit(1);
}
printf("[S] I said Hello to Client!\n");
//2. recv msg from client
if(recv(c_sock, buf, BUFFSIZE, 0) == -1) {
perror("[S] Can't receive message");
exit(1);
}
printf("[S] Client says: %s\n", buf);
exit(0);
}
close(c_sock);
}
/*
for(j=0; j<3; j++){
wait(&status);
printf("Patren waits %d\n"), wstatus;
}*/
}
p-client.c
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#define BUFFSIZE 4096
#define SERVERPORT 7799
int main(void){
int c_sock;
struct sockaddr_in server_addr;
socklen_t c_addr_size;
char buf[BUFFSIZE] = {0};
char hello[] = "Hi~I am Client!\n";
if((c_sock = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
perror("socket");
exit(1);
}
bzero(&server_addr, sizeof(server_addr));
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(SERVERPORT);
server_addr.sin_addr.s_addr = inet_addr("10.0.0.131");
printf("[C] Connecting...\n");
if (connect(c_sock, (struct sockaddr *) &server_addr, sizeof(server_addr) == -1)) {
perror("[C] Can't connect to a Server");
exit(1);
}
printf("[C] connected!\n");
//1. recv msg from server (maybe it's "hello")
if (recv(c_sock, buf, BUFFSIZE, 0) == -1) {
perror("[C] Can't receive message");
exit(1);
}
printf("[C] Server says: %s\n", buf);
//2. say hi to server
if(send(c_sock, hello, sizeof(hello)+1, 0) == -1) {
perror("[C] Can't send message");
exit(1);
}
printf("[C] I said Hi to Server!!\n");
printf("[C] I am going to sleep...\n");
sleep(10);
close(c_sock);
return 0;
}