main.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) 2005, 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: main.c,v 1.28 2007/08/02 10:20:25 bernd67 Exp $
 */

/* olsrd host-switch daemon */

#include "olsr_host_switch.h"
#include "link_rules.h"
#include "ohs_cmd.h"
#include <sys/types.h>
#include <sys/socket.h>
#include <errno.h>
#include <signal.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <time.h>

#ifdef WIN32
#undef errno
#define errno WSAGetLastError()
#undef strerror
#define strerror(x) StrError(x)
#define close(x) closesocket(x)
#else
#include <sys/wait.h>
#endif

static int srv_socket;

#define OHS_BUFSIZE 1500
static olsr_u8_t data_buffer[OHS_BUFSIZE];

struct ohs_connection *ohs_conns;

static int ip_version;
int ipsize;
static char ipv6_buf[100]; /* for address coversion */

olsr_u32_t logbits;

/* local functions */
static int
ohs_init_new_connection(int);

static int
ohs_route_data(struct ohs_connection *);

static int
ohs_init_connect_sockets(void);

static int
ohs_configure(void);

static void
ohs_listen_loop(void);

const char *
olsr_ip_to_string(const union olsr_ip_addr *addr)
{
  static int index = 0;
  static char buff[4][100];
  const char *ret;
  struct in_addr in;
  
  if(ip_version == AF_INET)
    {
      in.s_addr=addr->v4;
      ret = inet_ntoa(in);
    }
  else
    {
      /* IPv6 */
      ret = inet_ntop(AF_INET6, &addr->v6, ipv6_buf, sizeof(ipv6_buf));
    }

  strncpy(buff[index], ret, 100);

  ret = buff[index];

  index = (index + 1) & 3;

  return ret;
}


#ifdef WIN32
int __stdcall
ohs_close(unsigned long signal __attribute__((unused)))
#else
void
ohs_close(int signal __attribute__((unused)))
#endif
{
  printf("OHS: exit\n");

  close(srv_socket);

  exit(0);
}

struct ohs_connection *
get_client_by_addr(union olsr_ip_addr *adr)
{
  struct ohs_connection *oc = ohs_conns;

  while(oc)
    {
      if(COMP_IP(adr, &oc->ip_addr))
        return oc;
      oc = oc->next;
    }
  return NULL;
}


static int
ohs_init_new_connection(int s)
{
  struct ohs_connection *oc;
  olsr_u8_t new_addr[4];
  int i;

  if(logbits & LOG_CONNECT)
    printf("ohs_init_new_connection\n");

  /* Create new client node */
  oc = malloc(sizeof(struct ohs_connection));
  if(!oc)
    OHS_OUT_OF_MEMORY("New connection");

  memset(oc, 0, sizeof(oc));

  oc->socket = s;

  oc->links = NULL;
  oc->rx = 0;
  oc->tx = 0;
  oc->linkcnt = 0;

  // hack alert: WSAEventSelect makes sockets non-blocking, so the
  // recv() may return without having read anything on Windows; hence
  // re-try for 2 seconds on Windows; shouldn't harm Linux et al.

  /* Get "fake IP" */
  for (i = 0; i < 20; i++)
  {
    if (recv(oc->socket, new_addr, 4, 0) == 4)
      break;

#if defined WIN32
    Sleep(100);
#endif
  }

  if (i == 20)
  {
    printf("Failed to fetch IP address! (%s)\n", strerror(errno));
    return -1;
  }

  memcpy(&oc->ip_addr, new_addr, 4);
  oc->ip_addr.v4 = ntohl(oc->ip_addr.v4);
  if(logbits & LOG_CONNECT)
    printf("IP: %s\n", olsr_ip_to_string(&oc->ip_addr));

  if(get_client_by_addr(&oc->ip_addr))
    {
      if(logbits & LOG_CONNECT)
	printf("IP: %s DUPLICATE! Disconecting client!\n", olsr_ip_to_string(&oc->ip_addr));

      close(s);
      return -1;
    }

  /* Queue */
  oc->next = ohs_conns;
  ohs_conns = oc;

  return 1;
}

int
ohs_delete_connection(struct ohs_connection *oc)
{

  if(!oc)
    return -1;

  /* Close the socket */
  close(oc->socket);

  if(logbits & LOG_CONNECT)
    printf("Removing entry %s\n", olsr_ip_to_string(&oc->ip_addr));
  /* De-queue */
  if(oc == ohs_conns)
    {
      ohs_conns = ohs_conns->next;
    }
  else
    {
      struct ohs_connection *curr_entry, *prev_entry;
      curr_entry = ohs_conns->next;
      prev_entry = ohs_conns;
      
      while(curr_entry)
	{
	  if(curr_entry == oc)
	    {
	      prev_entry->next = curr_entry->next;
	      break;
	    }
	  prev_entry = curr_entry;
	  curr_entry = curr_entry->next;
	}
    }

  ohs_delete_all_related_links(oc);
  /* Free */
  free(oc);

  return 0;
}

static int
ohs_route_data(struct ohs_connection *oc)
{
  struct ohs_connection *ohs_cs;
  ssize_t len;
  int cnt = 0;

  oc->tx++;
  /* Read data */
  if((len = recv(oc->socket, data_buffer, OHS_BUFSIZE, 0)) <= 0)
    return -1;

  if(logbits & LOG_FORWARD)
    printf("Received %d bytes from %s\n", (int)len, olsr_ip_to_string(&oc->ip_addr));

  /* Loop trough clients */
  for(ohs_cs = ohs_conns; ohs_cs; ohs_cs = ohs_cs->next)
    {
      /* Check that the link is active open */
      if(ohs_check_link(oc, &ohs_cs->ip_addr) &&
	 oc->socket != ohs_cs->socket)
	{
	  ssize_t sent;

	  /* Send link addr */
	  if(send(ohs_cs->socket, oc->ip_addr.v6.s6_addr, ipsize, 0) != ipsize)
	    {
	      printf("Error sending link address!\n");
	    }
	  /* Send data */
	  if(logbits & LOG_FORWARD)
	    printf("Sending %d bytes %s=>%s\n", (int)len, 
		   olsr_ip_to_string(&oc->ip_addr),
		   olsr_ip_to_string(&ohs_cs->ip_addr));

	  if((sent = send(ohs_cs->socket, data_buffer, len, 0)) != len)
	    {
	      printf("Error sending(buf %d != sent %d)\n", (int)len, (int)sent);
	    }
	  ohs_cs->rx++;
	  cnt++;
	}
    }

  return cnt;
}

static int
ohs_init_connect_sockets(void)
{
  olsr_u32_t yes = 1;
  struct sockaddr_in sin;

  printf("Initiating socket TCP port %d\n", OHS_TCP_PORT);

  if((srv_socket = socket(AF_INET, SOCK_STREAM, 0)) < 0)
    {
      printf("Could not initialize socket(%d): %s\n", srv_socket, strerror(errno));
      exit(0);
    }

  if(setsockopt(srv_socket, SOL_SOCKET, SO_REUSEADDR, 
		(char *)&yes, sizeof(yes)) < 0) 
    {
      printf("SO_REUSEADDR failed for socket: %s\n", strerror(errno));
      close(srv_socket);
      exit(0);
    }

  /* complete the socket structure */
  memset(&sin, 0, sizeof(sin));
  sin.sin_family = AF_INET;
  sin.sin_addr.s_addr = INADDR_ANY;
  sin.sin_port = htons(OHS_TCP_PORT);
  
  /* bind the socket to the port number */
  if (bind(srv_socket, (struct sockaddr *) &sin, sizeof(sin)) == -1) 
    {
      printf("bind failed for socket: %s\n", strerror(errno));
      close(srv_socket);
      exit(0);
    }
  
  /* show that we are willing to listen */
  if (listen(srv_socket, 5) == -1) 
    {
      printf("listen failed for socket: %s\n", strerror(errno));
      close(srv_socket);
      exit(0);
    }
  return 1;
}


static int
ohs_configure(void)
{

  return 1;
}

static void accept_handler(void)
{
  struct sockaddr_in pin;
  socklen_t addrlen = sizeof(pin);
  int s;
	  
  memset(&pin, 0 , sizeof(pin));

  if((s = accept(srv_socket, (struct sockaddr *)&pin, &addrlen)) < 0)
    {
      printf("accept failed socket: %s\n", strerror(errno));
    }
  else
    {
      /* Create new node */
      ohs_init_new_connection(s);
    }
}

static void stdin_handler(void)
{
  ohs_parse_command();
}

static void read_handler(struct ohs_connection *con)
{
  if (ohs_route_data(con) < 0)
    ohs_delete_connection(con);
}

static void
ohs_listen_loop(void)
{
#if !defined WIN32
  int n;
  fd_set ibits;
  int fn_stdin = fileno(stdin);

  while(1)
    {
      int high;

      struct ohs_connection *ohs_cs;

      high = 0;
      FD_ZERO(&ibits);

      /* Add server socket */
      high = srv_socket;
      FD_SET(srv_socket, &ibits);

      if(fn_stdin > high) 
	high = fn_stdin;

      FD_SET(fn_stdin, &ibits);

      /* Add clients */
      for(ohs_cs = ohs_conns; ohs_cs; ohs_cs = ohs_cs->next)
	{
	  if(ohs_cs->socket > high)
	    high = ohs_cs->socket;
      
	  FD_SET(ohs_cs->socket, &ibits);
	}

      /* block */
      n = select(high + 1, &ibits, 0, 0, NULL);
      
      if(n == 0)
        continue;

      /* Did somethig go wrong? */
      if (n < 0) 
	{
	  if(errno == EINTR)
	    continue;
	  
	  printf("Error select: %s", strerror(errno));
          continue;
	}
      
      /* Check server socket */
      if(FD_ISSET(srv_socket, &ibits))
        accept_handler();

      /* Loop trough clients */
      ohs_cs = ohs_conns;
      while(ohs_cs)
	{
	  struct ohs_connection *ohs_tmp = ohs_cs;
	  ohs_cs = ohs_cs->next;

	  if(FD_ISSET(ohs_tmp->socket, &ibits))
            read_handler(ohs_tmp);
	}

      if(FD_ISSET(fn_stdin, &ibits))
        stdin_handler();

    }
#else
  HANDLE Objects[2];
  WSANETWORKEVENTS NetEvents;
  struct ohs_connection *Walker, *TmpWalker;
  unsigned int Res;

  Objects[0] = GetStdHandle(STD_INPUT_HANDLE);
  Objects[1] = WSACreateEvent();

  if (WSAEventSelect(srv_socket, Objects[1], FD_ACCEPT) == SOCKET_ERROR)
  {
    fprintf(stderr, "WSAEventSelect failed (1): %s\n", strerror(errno));
    return;
  }

  while (1)
  {
    for (Walker = ohs_conns; Walker != NULL; Walker = Walker->next)
    {
      if (WSAEventSelect(Walker->socket, Objects[1], FD_READ | FD_CLOSE) == SOCKET_ERROR)
      {
        fprintf(stderr, "WSAEventSelect failed (2): %s\n", strerror(errno));
        Sleep(1000);
        continue;
      }
    }

    Res = WaitForMultipleObjects(2, Objects, FALSE, INFINITE);

    if (Res == WAIT_FAILED)
    {
      fprintf(stderr, "WaitForMultipleObjects failed: %s\n", strerror(GetLastError()));
      Sleep(1000);
      continue;
    }

    if (Res == WAIT_OBJECT_0)
      stdin_handler();

    else if (Res == WAIT_OBJECT_0 + 1)
    {
      if (WSAEnumNetworkEvents(srv_socket, Objects[1], &NetEvents) == SOCKET_ERROR)
        fprintf(stderr, "WSAEnumNetworkEvents failed (1): %s\n", strerror(errno));

      else
      {
        if ((NetEvents.lNetworkEvents & FD_ACCEPT) != 0)
          accept_handler();
      }

      for (Walker = ohs_conns; Walker != NULL; Walker = TmpWalker)
      {
        TmpWalker = Walker->next;

        if (WSAEnumNetworkEvents(Walker->socket, Objects[1], &NetEvents) == SOCKET_ERROR)
          fprintf(stderr, "WSAEnumNetworkEvents failed (2): %s\n", strerror(errno));

        else
        {
          if ((NetEvents.lNetworkEvents & (FD_READ | FD_CLOSE)) != 0)
            read_handler(Walker);
        }
      }
    }
  }
  
#endif
}

int
main(void)
{

#ifdef WIN32
  WSADATA WsaData;

  if (WSAStartup(0x0202, &WsaData))
    {
      fprintf(stderr, "Could not initialize WinSock.\n");
      exit(EXIT_FAILURE);
    }

  SetConsoleCtrlHandler(ohs_close, OLSR_TRUE);

#else
  signal(SIGINT, ohs_close);  
  signal(SIGTERM, ohs_close);  

  /* Avoid zombie children */
  signal(SIGCHLD, SIG_IGN);
#endif

  printf("olsrd host-switch daemon version %s starting\n", OHS_VERSION);

  logbits = LOG_DEFAULT;
  ip_version = AF_INET;
  ipsize = 4;

  srand((unsigned int)time(NULL));

  ohs_set_olsrd_path(OHS_DEFAULT_OLSRD_PATH);

  ohs_init_connect_sockets();

  ohs_configure();

  printf("OHS command interpreter reading from STDIN\n");
  printf("\n> ");
  fflush(stdout);

  ohs_listen_loop();

  ohs_close(0);

  return 1;
}