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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>
#define __FAIL EXIT_FAILURE
#define BACKLOG 2
size_t bytes_recieved = 0;
void INThandler() {
fprintf(stderr, " SIGINT\n");
fprintf(stdout, "bytes recieved: %ld\n", bytes_recieved);
exit(0);
}
int main () {
int sockfd = -1; // socket fd
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_DGRAM;
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
fprintf(stdout, "Listening...\n");
struct sockaddr_storage from;
socklen_t fromlen = sizeof(struct sockaddr_storage);
size_t rlen = 1024;
int recv_ret;
signal(SIGINT, INThandler);
while(true) {
char recvmsg[rlen];
recv_ret = recvfrom(sockfd, recvmsg, rlen, 0, (struct sockaddr *)&from, &fromlen);
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);
}
return 0;
}
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