net.c

wifi 无线网络路由协议OLSR linux下C代码

/*
 * The olsr.org Optimized Link-State Routing daemon(olsrd)
 * Copyright (c) 2004, Andreas T鴑nesen([e-mail])
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions 
 * are met:
 *
 * * Redistributions of source code must retain the above copyright 
 *   notice, this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright 
 *   notice, this list of conditions and the following disclaimer in 
 *   the documentation and/or other materials provided with the 
 *   distribution.
 * * Neither the name of olsr.org, olsrd nor the names of its 
 *   contributors may be used to endorse or promote products derived 
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * Visit http://www.olsr.org for more information.
 *
 * If you find this software useful feel free to make a donation
 * to the project. For more information see the website or contact
 * the copyright holders.
 *
 * $Id: net.c,v 1.38 2007/10/04 22:27:31 bernd67 Exp $
 */

#include "defs.h"
#include "net_os.h"
#include "parser.h" /* dnc: needed for call to packet_parser() */
#include "net.h"

#include <net/if.h>

#ifdef __NetBSD__
#include <sys/param.h>
#include <net/if_ether.h>
#endif

#ifdef __OpenBSD__
#include <netinet/if_ether.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <netinet/icmp_var.h>
#include <netinet/icmp6.h>
#include <netinet6/in6_var.h> /* For struct in6_ifreq */
#include <ifaddrs.h>
#include <sys/uio.h>
#endif

#ifdef __FreeBSD__
#include <ifaddrs.h>
#include <net/if_var.h>
#include <net/ethernet.h>
#include <netinet/in_var.h>
#ifndef FBSD_NO_80211
#include <net80211/ieee80211.h>
#include <net80211/ieee80211_ioctl.h>
#endif
#endif

#ifdef __MacOSX__
#include <ifaddrs.h>
#include <net/if_var.h>
#include <net/ethernet.h>
#include <netinet/in_var.h>
#endif

#include <net/if_dl.h>
#ifdef SPOOF
#include <libnet.h>
#endif /* SPOOF */

//#define	SIOCGIFGENERIC	_IOWR('i', 58, struct ifreq)	/* generic IF get op */
//#define SIOCGWAVELAN SIOCGIFGENERIC

#include <sys/sysctl.h>

static int ignore_redir;
static int send_redir;
static int gateway;

static int set_sysctl_int(char *name, int new)
{
  int old;
#if __MacOSX__ || __OpenBSD__
  size_t len = sizeof (old);
#else
  unsigned int len = sizeof (old);
#endif

#ifdef __OpenBSD__
  int mib[4];

  /* Set net.inet.ip.forwarding by default. */
  mib[0] = CTL_NET;
  mib[1] = PF_INET;
  mib[2] = IPPROTO_IP;
  mib[3] = IPCTL_FORWARDING;

  if (!strcmp(name, "net.inet6.ip6.forwarding"))
  {
    mib[1] = PF_INET6;
    mib[2] = IPPROTO_IPV6;
  }
  else if (!strcmp(name, "net.inet.icmp.rediraccept"))
  {
    mib[2] = IPPROTO_ICMP;
    mib[3] = ICMPCTL_REDIRACCEPT;
  }
  else if (!strcmp(name, "net.inet6.icmp6.rediraccept"))
  {
    mib[2] = IPPROTO_ICMPV6;
    mib[3] = ICMPV6CTL_REDIRACCEPT;
  }
  else if (!strcmp(name, "net.inet.ip.redirect"))
  {
    mib[3] = IPCTL_SENDREDIRECTS;
  }
  else if (!strcmp(name, "net.inet6.ip6.redirect"))
  {
    mib[1] = PF_INET6;
    mib[2] = IPPROTO_IPV6;
    mib[3] = IPCTL_SENDREDIRECTS;
  }

  if (sysctl(mib, 4, &old, &len, &new, sizeof (new)) < 0)
    return -1;
#else

  if (sysctlbyname(name, &old, &len, &new, sizeof (new)) < 0)
    return -1;
#endif

  return old;
}

int enable_ip_forwarding(int version)
{
  char *name;

  if (olsr_cnf->ip_version == AF_INET)
    name = "net.inet.ip.forwarding";

  else
    name = "net.inet6.ip6.forwarding";

  gateway = set_sysctl_int(name, 1);

  if (gateway < 0)
    {
      fprintf(stderr, "Cannot enable IP forwarding. Please enable IP forwarding manually. Continuing in 3 seconds...\n");
      sleep(3);
    }

  return 1;
}

int
disable_redirects_global(int version)
{
  char *name;

  // do not accept ICMP redirects

#ifdef __OpenBSD__
  if (olsr_cnf->ip_version == AF_INET)
    name = "net.inet.icmp.rediraccept";

  else
    name = "net.inet6.icmp6.rediraccept";

  ignore_redir = set_sysctl_int(name, 0);
#elif defined __FreeBSD__ || defined __MacOSX__
  if (olsr_cnf->ip_version == AF_INET)
  {
    name = "net.inet.icmp.drop_redirect";
    ignore_redir = set_sysctl_int(name, 1);
  }
  else
  {
    name = "net.inet6.icmp6.rediraccept";
    ignore_redir = set_sysctl_int(name, 0);
  }
#else
  if (olsr_cnf->ip_version == AF_INET)
    name = "net.inet.icmp.drop_redirect";

  else
    name = "net.inet6.icmp6.drop_redirect";

  ignore_redir = set_sysctl_int(name, 1);
#endif

  if (ignore_redir < 0)
    {
      fprintf(stderr, "Cannot disable incoming ICMP redirect messages. Please disable them manually. Continuing in 3 seconds...\n");
      sleep(3);
    }

  // do not send ICMP redirects

  if (olsr_cnf->ip_version == AF_INET)
    name = "net.inet.ip.redirect";

  else
    name = "net.inet6.ip6.redirect";

  send_redir = set_sysctl_int(name, 0);

  if (send_redir < 0)
    {
      fprintf(stderr, "Cannot disable outgoing ICMP redirect messages. Please disable them manually. Continuing in 3 seconds...\n");
      sleep(3);
    }

  return 1;
}

int disable_redirects(const char *if_name, struct interface *iface, int version)
{
  // this function gets called for each interface olsrd uses; however,
  // FreeBSD can only globally control ICMP redirects, and not on a
  // per-interface basis; hence, only disable ICMP redirects in the "global"
  // function
  return 1;
}

int deactivate_spoof(const char *if_name, struct interface *iface, int version)
{
  return 1;
}

int restore_settings(int version)
{
  char *name;

  // reset IP forwarding

  if (olsr_cnf->ip_version == AF_INET)
    name = "net.inet.ip.forwarding";

  else
    name = "net.inet6.ip6.forwarding";

  set_sysctl_int(name, gateway);

  // reset incoming ICMP redirects

#ifdef __OpenBSD__
  if (olsr_cnf->ip_version == AF_INET)
    name = "net.inet.icmp.rediraccept";
  else
    name = "net.inet6.icmp6.rediraccept";

#elif defined __FreeBSD__ || defined __MacOSX__
  if (olsr_cnf->ip_version == AF_INET)
    name = "net.inet.icmp.drop_redirect";

  else
    name = "net.inet6.icmp6.rediraccept";
#else
  if (olsr_cnf->ip_version == AF_INET)
    name = "net.inet.icmp.drop_redirect";

  else
    name = "net.inet6.icmp6.drop_redirect";
#endif

  set_sysctl_int(name, ignore_redir);

  // reset outgoing ICMP redirects

  if (olsr_cnf->ip_version == AF_INET)
    name = "net.inet.ip.redirect";

  else
    name = "net.inet6.ip6.redirect";

  set_sysctl_int(name, send_redir);

  return 1;
}


/**
 *Creates a nonblocking broadcast socket.
 *@param sa sockaddr struct. Used for bind(2).
 *@return the FD of the socket or -1 on error.
 */
int
gethemusocket(struct sockaddr_in *pin)
{
  int sock, on = 1;

  OLSR_PRINTF(1, "       Connecting to switch daemon port 10150...");


  if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) 
    {
      perror("hcsocket");
      syslog(LOG_ERR, "hcsocket: %m");
      return (-1);
    }

  if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0) 
    {
      perror("SO_REUSEADDR failed");
      close(sock);
      return (-1);
    }
  /* connect to PORT on HOST */
  if (connect(sock,(struct sockaddr *) pin, sizeof(*pin)) < 0) 
    {
      printf("FAILED\n");
      fprintf(stderr, "Error connecting %d - %s\n", errno, strerror(errno));
      printf("connection refused\n");
      close(sock);
      return (-1);
    }

  printf("OK\n");

  /* Keep TCP socket blocking */  
  return (sock);
}


int
getsocket(struct sockaddr *sa, int bufspace, char *int_name)
{
  struct sockaddr_in *sin = (struct sockaddr_in *)sa;
  int sock, on = 1;

  if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0) 
    {
      perror("socket");
      syslog(LOG_ERR, "socket: %m");
      return (-1);
    }

  if (setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &on, sizeof (on)) < 0)
    {
      perror("setsockopt");
      syslog(LOG_ERR, "setsockopt SO_BROADCAST: %m");
      close(sock);
      return (-1);
    }

  if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0) 
    {
      perror("SO_REUSEADDR failed");
      close(sock);
      return (-1);
    }

  if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &on, sizeof(on)) < 0) 
    {
      perror("SO_REUSEPORT failed");
      close(sock);
      return (-1);
    }

  if (setsockopt(sock, IPPROTO_IP, IP_RECVIF, &on, sizeof(on)) < 0) 
    {
      perror("IP_RECVIF failed");
      close(sock);
      return (-1);
    }

  for (on = bufspace; ; on -= 1024) 
    {
      if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
		     &on, sizeof (on)) == 0)
	break;
      if (on <= 8*1024) 
	{
	  perror("setsockopt");
	  syslog(LOG_ERR, "setsockopt SO_RCVBUF: %m");
	  break;
	}
    }

  if (bind(sock, (struct sockaddr *)sin, sizeof (*sin)) < 0) 
    {
      perror("bind");
      syslog(LOG_ERR, "bind: %m");
      close(sock);
      return (-1);
    }

  if (fcntl(sock, F_SETFL, O_NONBLOCK) == -1)
    syslog(LOG_ERR, "fcntl O_NONBLOCK: %m\n");

  return (sock);
}

int getsocket6(struct sockaddr_in6 *sin, int bufspace, char *int_name)
{
  int sock, on = 1;

  if ((sock = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 
    {
      perror("socket");
      syslog(LOG_ERR, "socket: %m");
      return (-1);
    }

  for (on = bufspace; ; on -= 1024) 
    {
      if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
		     &on, sizeof (on)) == 0)
	break;
      if (on <= 8*1024) 
	{
	  perror("setsockopt");
	  syslog(LOG_ERR, "setsockopt SO_RCVBUF: %m");
	  break;
	}
    }

  if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0) 
    {