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#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <unistd.h>
#include <stdbool.h>
#include <fcntl.h>
#include <stdlib.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <signal.h>
// int listen(int sockfd, int backlog);
#define __FAIL EXIT_FAILURE
#define BACKLOG 128
int sockfd = -1;
void INThandler () {
close(sockfd);
fprintf(stderr, " SIGINT\n");
exit(0);
}
size_t recv_message_loop (int newfd) {
size_t rlen = 1024;
int recv_ret;
size_t bytes_recieved = 0;
while(true) {
char recvmsg[rlen];
recv_ret = recv(newfd, recvmsg, rlen, 0);
bytes_recieved = bytes_recieved+recv_ret;
if (recv_ret < 1) {
break;
}
recvmsg[recv_ret] = '\0';
fprintf(stdout, "%s", recvmsg);
//fprintf(stdout, "loop");
memset(&recvmsg, 0, rlen);
}
if (recv_ret == -1) {
bytes_recieved = bytes_recieved + 1;
}
fprintf(stdout, "bytes recieved: %ld\n", bytes_recieved);
return bytes_recieved;
}
int main (void) {
// sockfd is at the top of the file!!!
int gai_result; // result from getaddrinfo
int bind_result = -1; // result from bind
struct addrinfo *res; // Pointer to linked list sent back by gai
struct addrinfo *p; // for linked list stuff
struct addrinfo hints; // Options we pass to gai
memset(&hints, 0, sizeof(hints)); // We set this struct to 0 and then give it all the options we want below
hints.ai_family = AF_INET;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_PASSIVE;
gai_result = getaddrinfo(NULL, "62000", &hints, &res); // NULL because we are going to listen
if (gai_result != 0) {
fprintf(stderr, "gai_result: %d\n", gai_result);
exit(__FAIL);
}
for (p = res ; p != NULL ; p = p->ai_next) { // Loop
sockfd = socket(p->ai_family, p->ai_socktype, p->ai_protocol); // Socket, get the family, socktype and protocol.
if (sockfd == -1) {
fprintf(stderr, "sockfd: %d\n", sockfd);
continue;
}
bind_result = bind(sockfd, p->ai_addr, p->ai_addrlen); // Bind to socket fd. pass our own address (ai_addr) and the length
if (bind_result != 0) {
fprintf(stderr, "bind_result: %d\n", bind_result);
close(sockfd);
continue;
}
}
if (sockfd == -1 || bind_result == -1) {
exit(__FAIL);
}
freeaddrinfo(res); // free the info because we dont need it anymore
listen(sockfd, BACKLOG); // Actually listen for connections with the sockfd
signal(SIGINT, INThandler);
while (1) {
fprintf(stdout, "Waiting for a connection...\n");
int newfd;
socklen_t addr_size; // Size of address
struct sockaddr_storage their_addr; // pass this struct to accept because it will hold their address
addr_size = sizeof(their_addr); // Check the size of their addr
newfd = accept(sockfd, (struct sockaddr *)&their_addr, &addr_size); // Actually accept. Pass the sockfd, cast their_addr to sockaddr and send the address to the function. Pass the addr_size address so we can handle the length.
fprintf(stdout, "Connection is being established...\n");
if (newfd == -1) {
exit(__FAIL);
}
char host_ip[NI_MAXHOST];
char port_port[NI_MAXSERV];
int gni;
gni = getnameinfo((struct sockaddr *)&their_addr, addr_size, host_ip, sizeof(host_ip), port_port, sizeof(port_port), NI_NUMERICSERV | NI_NUMERICHOST);
if (gni == 0) {
fprintf(stdout, "Client %s %s just connected!\n", host_ip, port_port);
}
char *msg = "Connected\n";
send(newfd, msg, 10, 0);
recv_message_loop(newfd);
close(newfd);
}
return 0;
}
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