givemeSockets.c

/*
** listener.c -- a datagram sockets "server" demo
** From http://beej.us/guide/bgnet/examples/listener.c
*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>

#define MYPORT "4950"	// the port users will be connecting to

#define MAXBUFLEN 100

// get sockaddr, IPv4 or IPv6:
void *get_in_addr(struct sockaddr *sa)
{
	if (sa->sa_family == AF_INET) {
		return &(((struct sockaddr_in*)sa)->sin_addr);
	}

	return &(((struct sockaddr_in6*)sa)->sin6_addr);
}

int main(int argc, char *argv[])
{
  int sockfd[100000];
  struct addrinfo hints, *servinfo, *p;
  int rv;
  int numbytes;
  struct sockaddr_storage their_addr;
  struct sockaddr_in *the_addr;
  char buf[MAXBUFLEN];
  socklen_t addr_len;
  
  
  char s[INET6_ADDRSTRLEN];
  
  memset(&hints, 0, sizeof hints);
  hints.ai_family = AF_UNSPEC; // set to AF_INET to force IPv4
  hints.ai_socktype = SOCK_DGRAM;
  hints.ai_flags = AI_PASSIVE; // use my IP
  
  if ((rv = getaddrinfo(NULL, MYPORT, &hints, &servinfo)) != 0) {
    fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
    return 1;
  }
  
  
  int count=0;
  
  while(count<atoi(argv[1])){
    
    // loop through all the results and bind to the first we can
    for(p = servinfo; p != NULL; p = p->ai_next) {
      if ((sockfd[count] = socket(p->ai_family, p->ai_socktype,
				  p->ai_protocol)) == -1) {
	perror("listener: socket");
	continue;
      }
      
      /*
	if (bind(sockfd, p->ai_addr, p->ai_addrlen) == -1) {
	close(sockfd);
	perror("listener: bind");
	continue;
	}
      */
      break;
    }
    
    if (p == NULL) {
      fprintf(stderr, "listener: failed to bind socket\n");
      return 2;
    }
    
    count++;
  }
  
  freeaddrinfo(servinfo);
  
  printf("Done");
  count=0;
  while(count<atoi(argv[1])){
    close(sockfd[count]);
    count++;
  }
  return 0;
}