quagga.c

wifi 无线网络路由协议OLSR linux下C代码

/***************************************************************************
 projekt              : olsrd-quagga
 file                 : quagga.c  
 usage                : communication with the zebra-daemon 
 copyright            : (C) 2006 by Immo 'FaUl' Wehrenberg
 e-mail               : [e-mail]
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License version 2 as     *
 *   published by the Free Software Foundation.                            *
 *                                                                         *
 ***************************************************************************/


#ifdef MY_DEBUG
#include <stdio.h>
#endif

#define HAVE_SOCKLEN_T

#include <stdint.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <quagga/zebra.h>
#include "quagga.h"

#include "olsr.h"
#include "log.h"
#include "defs.h"
#include "local_hna_set.h"
#include "routing_table.h"

#ifdef USE_UNIX_DOMAIN_SOCKET
#include <sys/un.h>
#define ZEBRA_SOCKET "/var/run/quagga/zserv.api"
#endif

#define ZAPI_MESSAGE_NEXTHOP  0x01
#define ZAPI_MESSAGE_IFINDEX  0x02
#define ZAPI_MESSAGE_DISTANCE 0x04
#define ZAPI_MESSAGE_METRIC   0x08

#define BUFSIZE 1024

#define STATUS_CONNECTED 1
#define OPTION_EXPORT 1

static struct {
  char status; // internal status
  char options; // internal options
  int sock; // Socket to zebra...
  char redistribute[ZEBRA_ROUTE_MAX];
  char distance;
  char flags;
  struct ipv4_route *v4_rt; // routes currently exportet to zebra
} zebra;


/* prototypes intern */
static unsigned char *try_read (ssize_t *);
static unsigned char* zebra_route_packet (struct ipv4_route r, ssize_t *);
static int parse_interface_add (unsigned char *, size_t);
static int parse_interface_delete (unsigned char *, size_t);
static int parse_interface_up (unsigned char *, size_t);
static int parse_interface_down (unsigned char *, size_t);
static int parse_interface_address_add (unsigned char *, size_t);
static int parse_interface_address_delete (unsigned char *, size_t);
static int parse_ipv4_route (unsigned char *, size_t, struct ipv4_route *);
static int ipv4_route_add (unsigned char *, size_t);
static int ipv4_route_delete (unsigned char *, size_t);
static int parse_ipv6_route_add (unsigned char*, size_t);
static void zebra_reconnect (void);
static void zebra_connect (void);

static uint32_t prefixlentomask (uint8_t);
static void free_ipv4_route (struct ipv4_route);
/* 
static void update_olsr_zebra_routes (struct ipv4_route*, struct ipv4_route*);
static struct ipv4_route *zebra_create_ipv4_route_table_entry (uint32_t,
							       uint32_t,
							       uint32_t);
static struct ipv4_route *zebra_create_ipv4_route_table (void);
static void zebra_free_ipv4_route_table (struct ipv4_route*);
*/

/*static uint8_t masktoprefixlen (uint32_t);*/


#ifdef MY_DEBUG
static void dump_ipv4_route (struct ipv4_route r, char *c) {
  int i = 0, x = 0;

  puts (c);
  printf("type: %d\n", r.type);
  puts("flags:");
  printf("  Internal: %s\n",r.flags&ZEBRA_FLAG_INTERNAL?"yes":"no");
  printf("  Selfroute %s\n",r.flags&ZEBRA_FLAG_SELFROUTE?"yes":"no");
  printf("  Blackhole %s\n",r.flags&ZEBRA_FLAG_BLACKHOLE?"yes":"no");
  printf("  IBGP: %s\n",r.flags&ZEBRA_FLAG_IBGP?"yes":"no");
  printf("  Selected: %s\n",r.flags&ZEBRA_FLAG_SELECTED?"yes":"no");
  printf("  Changed: %s\n",r.flags&ZEBRA_FLAG_CHANGED?"yes":"no");
  printf("  static: %s\n",r.flags&ZEBRA_FLAG_STATIC?"yes":"no");
  printf("  reject: %s\n",r.flags&ZEBRA_FLAG_REJECT?"yes":"no");
  puts("message:");
  printf("  nexthop: %s\n",r.message&ZAPI_MESSAGE_NEXTHOP?"yes":"no");
  printf("  ifindex: %s\n",r.message&ZAPI_MESSAGE_IFINDEX?"yes":"no");
  printf("  distance: %s\n",r.message&ZAPI_MESSAGE_DISTANCE?"yes":"no");
  printf("  metric: %s\n",r.message&ZAPI_MESSAGE_METRIC?"yes":"no");
  printf("Prefixlen: %d\n", r.prefixlen);
  printf("Prefix: %d", (unsigned char)r.prefix);
  c = (char*) &r.prefix;
  while (++i < (r.prefixlen/8 + (r.prefixlen % 8 ? 1 : 0)))
    printf(".%d",(unsigned char)*(c + i));
  while (i++ < 4)
    printf(".0");
  puts("");
  i=0;
  if (r.message&ZAPI_MESSAGE_NEXTHOP) {
    printf("nexthop-count: %d\n", r.nh_count);
    while (i++ < r.nh_count) {
      if (r.nexthops[i].type == ZEBRA_NEXTHOP_IPV4) {
	c = (unsigned char*) &r.nexthops[i].payload.v4;
	printf ("Nexthop %d: %d", i, (unsigned char) *c);
	while (++x < 4) {
	  printf (".%d", (unsigned char) c[x]);
	}
	puts("");
      }
    }
    i=0;
  }
  if (r.message&ZAPI_MESSAGE_IFINDEX) {
    
    printf("index-number: %d\n", r.ind_num);
    while (i++ < r.ind_num)
      printf("Index: %d: %d\n", i, r.index[i]);
    i=0;
    if (r.message&ZAPI_MESSAGE_DISTANCE)
      printf("Distance: %d\n",r.distance);
    if (r.message&ZAPI_MESSAGE_METRIC)
      printf("Metric: %d\n",r.metric);
    puts("\n");
  }
}
#endif

void *my_realloc (void *buf, size_t s, const char *c) {
  buf = realloc (buf, s);
  if (!buf) {
    OLSR_PRINTF (1, "(QUAGGA) OUT OF MEMORY: %s\n", strerror(errno));
    olsr_syslog(OLSR_LOG_ERR, "olsrd: out of memory!: %m\n");
    olsr_exit(c, EXIT_FAILURE);
  }
  return buf;
}

void init_zebra (void) {
  zebra_connect();
  if (!zebra.status&STATUS_CONNECTED)
    olsr_exit ("(QUAGGA) AIIIII, could not connect to zebra! is zebra running?", 
	       EXIT_FAILURE);
}

void zebra_cleanup (void) {
  int i;
  struct rt_entry *tmp;
  
  if (zebra.options & OPTION_EXPORT) {
    OLSR_FOR_ALL_RT_ENTRIES(tmp) {
      zebra_del_olsr_v4_route(tmp);
    } OLSR_FOR_ALL_RT_ENTRIES_END(tmp);
  }

  for (i = 0; i < ZEBRA_ROUTE_MAX; i++)
    if (zebra.redistribute[i]) zebra_disable_redistribute(i + 1);
}


static void zebra_reconnect (void) {
  struct rt_entry *tmp;
  int i;

  zebra_connect();
  if (!zebra.status & STATUS_CONNECTED) return; // try again next time

  if (zebra.options & OPTION_EXPORT) {
    OLSR_FOR_ALL_RT_ENTRIES(tmp) {
      zebra_add_olsr_v4_route (tmp);
    } OLSR_FOR_ALL_RT_ENTRIES_END(tmp);
  }  

  for (i = 0; i < ZEBRA_ROUTE_MAX; i++)
    if (zebra.redistribute[i]) zebra_redistribute(i + 1);
  /* Zebra sends us all routes of type it knows after 
     zebra_redistribute(type) */
}



/* Connect to the zebra-daemon, returns a socket */
static void zebra_connect (void) {
  
  int ret;

#ifndef USE_UNIX_DOMAIN_SOCKET
  struct sockaddr_in i;
  if (close (zebra.sock) < 0) olsr_exit ("(QUAGGA) Could not close socket!", EXIT_FAILURE);
  

  zebra.sock = socket (AF_INET,SOCK_STREAM, 0);
#else
  struct sockaddr_un i;
  if (close (zebra.sock) < 0) olsr_exit ("(QUAGGA) Could not close socket!", EXIT_FAILURE);

  zebra.sock = socket (AF_UNIX,SOCK_STREAM, 0);
#endif

  if (zebra.sock <0 )
    olsr_exit("(QUAGGA) Could not create socket!", EXIT_FAILURE);
  
  memset (&i, 0, sizeof i);
#ifndef USE_UNIX_DOMAIN_SOCKET
  i.sin_family = AF_INET;
  i.sin_port = htons (ZEBRA_PORT);
  i.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
#else
  i.sun_family = AF_UNIX;
  strcpy (i.sun_path, ZEBRA_SOCKET);
#endif

  ret = connect (zebra.sock, (struct sockaddr *)&i, sizeof i);
  if  (ret < 0) zebra.status &= ~STATUS_CONNECTED;
  else zebra.status |= STATUS_CONNECTED;
}

    
/* Sends a command to zebra, command is 
   the command defined in zebra.h, options is the packet-payload, 
   optlen the length, of the payload */
unsigned char zebra_send_command (unsigned char command, 
                                  unsigned char *options, int optlen) {

#ifdef ZEBRA_HEADER_MARKER
  char *p = olsr_malloc (optlen + 6, "zebra_send_command");
  uint16_t length = optlen + 6; /* length of option + command + packet_length +
				   marker + zserv-version */
  uint16_t cmd;
#else
  char *p = olsr_malloc (optlen + 3, "zebra_send_command");
  uint16_t length = optlen + 3;  // length of option + command + packet_length
#endif
  char *pnt = p;
  int ret;
  
  uint16_t len = htons(length);

  memcpy (p, &len, 2);

#ifdef ZEBRA_HEADER_MARKER
  p[2] = ZEBRA_HEADER_MARKER;
  p[3] = ZSERV_VERSION;
  cmd = htons (command);
  memcpy (p + 4, &cmd, 2);
  memcpy (p + 6, options, optlen);
#else
  p[2] = command;
  memcpy (p + 3, options, optlen);
#endif

  errno = 0;

  do {
    ret = write (zebra.sock, p, length);
    if (ret < 0) {
      if (errno == EINTR) {
	errno = 0;
	continue;
      }
      else {
	olsr_printf (1, "(QUAGGA) Disconnected from zebra\n");
	zebra.status &= ~STATUS_CONNECTED;
	free (pnt);
	return -1;
      }
    }
    p = p+ret;
  } while ((length -= ret));
  free (pnt);
  return 0;
}


/* Creates a Route-Packet-Payload, needs address, netmask, nexthop, 
   distance, and a pointer of an size_t */
static unsigned char* zebra_route_packet (struct ipv4_route r, 
                                          ssize_t *optlen) {

  int count;

  unsigned char *cmdopt, *t;
  *optlen = 4; // first: type, flags, message, prefixlen
  *optlen += r.prefixlen / 8 + (r.prefixlen % 8 ? 1 : 0); // + prefix
  if (r.message & ZAPI_MESSAGE_NEXTHOP) {
    if (r.nexthops->type == ZEBRA_NEXTHOP_IPV4 
	|| r.nexthops->type == ZEBRA_NEXTHOP_IPV4_IFINDEX){
      *optlen += (sizeof r.nexthops->payload.v4 
		  + sizeof r.nexthops->type) * r.nh_count + 1;
    }
    else if (r.nexthops->type == 0) 
      *optlen += 5;
  }
  if (r.message & ZAPI_MESSAGE_IFINDEX)
    *optlen += r.ind_num * sizeof *r.index + 1;
  if (r.message & ZAPI_MESSAGE_DISTANCE)
    (*optlen)++;
  if (r.message & ZAPI_MESSAGE_METRIC)
    *optlen += sizeof r.metric;

  cmdopt = olsr_malloc (*optlen, "zebra add_v4_route");

  t = cmdopt;
  *t++ = r.type; 
  *t++ = r.flags; 
  *t++ = r.message;
  *t++ = r.prefixlen;
  for (count = 0; count < r.prefixlen/8 + (r.prefixlen % 8 ? 1 : 0); count++) {
    *t++ = *((char*)&r.prefix + count); /* this is so sick!! */
  }

  if (r.message & ZAPI_MESSAGE_NEXTHOP) {
    *t++ = r.nh_count;
    *t++ = r.nexthops->type;
    if (r.nexthops->type == ZEBRA_NEXTHOP_IPV4 || 
	r.nexthops->type == ZEBRA_NEXTHOP_IPV4_IFINDEX) {
      for (count = 0; count != r.nh_count; count++) {
	memcpy (t, &r.nexthops[count].payload.v4, 
		sizeof r.nexthops->payload.v4);
	t += sizeof r.nexthops->payload.v4;
      }
    }
    else if (r.nexthops->type == 0) {
      *t++ = 0;
      *t++ = 0;
      *t++ = 0;
    }
  }
  if (r.message & ZAPI_MESSAGE_IFINDEX) {
    *t++ = r.ind_num;
    memcpy (t, r.index, sizeof *r.index * r.ind_num);
    t += sizeof r.index * r.ind_num;
  }
  if (r.message & ZAPI_MESSAGE_DISTANCE)
    *t++ = r.distance;
  if (r.message & ZAPI_MESSAGE_METRIC) {
    memcpy (t, &r.metric, sizeof r.metric);
    t += sizeof r.metric;
  }
  return cmdopt;
}


/* adds a route to zebra-daemon */
int zebra_add_v4_route (struct ipv4_route r) {
  
  unsigned char *cmdopt;
  ssize_t optlen;
  int retval;

  cmdopt = zebra_route_packet (r, &optlen);

  retval = zebra_send_command (ZEBRA_IPV4_ROUTE_ADD, cmdopt, optlen);
  free (cmdopt);
  return retval;
  
}

/* deletes a route from the zebra-daemon */
int zebra_delete_v4_route (struct ipv4_route r) {
  
  unsigned char *cmdopt;
  ssize_t optlen;
  int retval;

  cmdopt = zebra_route_packet (r, &optlen);
  
  retval = zebra_send_command (ZEBRA_IPV4_ROUTE_DELETE, cmdopt, optlen);
  free (cmdopt);

  return retval;
  
}


/* Check wether there is data from zebra aviable */
void zebra_check (void* foo __attribute__((unused))) {
  unsigned char *data, *f;
  ssize_t len, ret;

  if (!(zebra.status & STATUS_CONNECTED)) {
    zebra_reconnect();
    return;
  }
  data = try_read (&len);
  if (data) {
    f = data;
    do {
      ret = zebra_parse_packet (f, len);
      if (!ret) // something wired happened
	olsr_exit ("(QUAGGA) Zero message length??? ", EXIT_FAILURE);
      f += ret;
    } while ((f - data) < len);
    free (data);
  }
}


// tries to read a packet from zebra_socket
// if there is something to read - make sure to read whole packages
static unsigned char *try_read (ssize_t *len) {