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ip.c

/*
 * ip.c
 *
 * Copyright (c) 2000 Dug Song <dugsong@monkey.org>
 *
 * $Id: ip.c,v 1.29 2005/01/25 21:30:40 dugsong Exp $
 */

#include "config.h"

#include <netinet/in.h>

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "dnet.h"

struct ip_handle {
      int   fd;
};

ip_t *
ip_open(void)
{
      ip_t *i;
      int n, len;

      if ((i = calloc(1, sizeof(*i))) == NULL)
            return (NULL);

      if ((i->fd = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) < 0)
            return (ip_close(i));
#ifdef IP_HDRINCL
      n = 1;
      if (setsockopt(i->fd, IPPROTO_IP, IP_HDRINCL, &n, sizeof(n)) < 0)
            return (ip_close(i));
#endif
#ifdef SO_SNDBUF
      len = sizeof(n);
      if (getsockopt(i->fd, SOL_SOCKET, SO_SNDBUF, &n, &len) < 0)
            return (ip_close(i));

      for (n += 128; n < 1048576; n += 128) {
            if (setsockopt(i->fd, SOL_SOCKET, SO_SNDBUF, &n, len) < 0) {
                  if (errno == ENOBUFS)
                        break;
                  return (ip_close(i));
            }
      }
#endif
#ifdef SO_BROADCAST
      n = 1;
      if (setsockopt(i->fd, SOL_SOCKET, SO_BROADCAST, &n, sizeof(n)) < 0)
            return (ip_close(i));
#endif
      return (i);
}

ssize_t
ip_send(ip_t *i, const void *buf, size_t len)
{
      struct ip_hdr *ip;
      struct sockaddr_in sin;

      ip = (struct ip_hdr *)buf;

      memset(&sin, 0, sizeof(sin));
#ifdef HAVE_SOCKADDR_SA_LEN       
      sin.sin_len = sizeof(sin);
#endif
      sin.sin_family = AF_INET;
      sin.sin_addr.s_addr = ip->ip_dst;
      
#ifdef HAVE_RAWIP_HOST_OFFLEN
      ip->ip_len = ntohs(ip->ip_len);
      ip->ip_off = ntohs(ip->ip_off);

      len = sendto(i->fd, buf, len, 0,
          (struct sockaddr *)&sin, sizeof(sin));
      
      ip->ip_len = htons(ip->ip_len);
      ip->ip_off = htons(ip->ip_off);

      return (len);
#else
      return (sendto(i->fd, buf, len, 0,
          (struct sockaddr *)&sin, sizeof(sin)));
#endif
}

ip_t *
ip_close(ip_t *i)
{
      if (i != NULL) {
            if (i->fd >= 0)
                  close(i->fd);
            free(i);
      }
      return (NULL);
}

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