自学教程：C++ IF_NAME函数代码示例

intif_setsockopt_bindtodevice(int *sd, interface_t *ifp){	int ret;	if (*sd < 0)		return -1;	/* -> inbound processing option	 * Specify the bound_dev_if.	 * why IP_ADD_MEMBERSHIP & IP_MULTICAST_IF doesnt set	 * sk->bound_dev_if themself ??? !!!	 * Needed for filter multicasted advert per interface.	 *	 * -- If you read this !!! and know the answer to the question	 *    please feel free to answer me ! :)	 */	ret = setsockopt(*sd, SOL_SOCKET, SO_BINDTODEVICE, IF_NAME(ifp), strlen(IF_NAME(ifp)) + 1);	if (ret < 0) {		log_message(LOG_INFO, "cant bind to device %s. errno=%d. (try to run it as root)",			    IF_NAME(ifp), errno);		close(*sd);		*sd = -1;	}	return *sd;}

/* Execute NSM event process. */intospf_nsm_event (struct thread *thread){  int event;  int next_state;  struct ospf_neighbor *nbr;  struct in_addr router_id;  int old_state;  struct ospf_interface *oi;  nbr = THREAD_ARG (thread);  event = THREAD_VAL (thread);  router_id = nbr->router_id;  old_state = nbr->state;  oi = nbr->oi ;    /* Call function. */  next_state = (*(NSM [nbr->state][event].func))(nbr);  /* When event is NSM_KillNbr or InactivityTimer, the neighbor is     deleted. */  if (event == NSM_KillNbr || event == NSM_InactivityTimer)    {      if (IS_DEBUG_OSPF (nsm, NSM_EVENTS))	zlog_debug ("NSM[%s:%s]: neighbor deleted",		   IF_NAME (oi), inet_ntoa (router_id));      /* Timers are canceled in ospf_nbr_free, moreover we cannot call         nsm_timer_set here because nbr is freed already!!!*/      /*nsm_timer_set (nbr);*/      return 0;    }  if (! next_state)    next_state = NSM [nbr->state][event].next_state;  if (IS_DEBUG_OSPF (nsm, NSM_EVENTS))    zlog_debug ("NSM[%s:%s]: %s (%s)", IF_NAME (oi),	       inet_ntoa (nbr->router_id),	       LOOKUP (ospf_nsm_state_msg, nbr->state),	       ospf_nsm_event_str [event]);    /* If state is changed. */  if (next_state != nbr->state)    nsm_change_state (nbr, next_state);  /* Make sure timer is set. */  nsm_timer_set (nbr);  return 0;}

static voidnsm_notice_state_change (struct ospf_neighbor *nbr, int next_state, int event){  /* Logging change of status. */  if (IS_DEBUG_OSPF (nsm, NSM_STATUS))    zlog_debug ("NSM[%s:%s]: State change %s -> %s (%s)",               IF_NAME (nbr->oi), inet_ntoa (nbr->router_id),               LOOKUP (ospf_nsm_state_msg, nbr->state),               LOOKUP (ospf_nsm_state_msg, next_state),               ospf_nsm_event_str [event]);  /* Optionally notify about adjacency changes */  if (CHECK_FLAG(nbr->oi->ospf->config, OSPF_LOG_ADJACENCY_CHANGES) &&      (CHECK_FLAG(nbr->oi->ospf->config, OSPF_LOG_ADJACENCY_DETAIL) ||       (next_state == NSM_Full) || (next_state < nbr->state)))    zlog_notice("AdjChg: Nbr %s on %s: %s -> %s (%s)",                inet_ntoa (nbr->router_id), IF_NAME (nbr->oi),                LOOKUP (ospf_nsm_state_msg, nbr->state),                LOOKUP (ospf_nsm_state_msg, next_state),                ospf_nsm_event_str [event]);  /* Advance in NSM */  if (next_state > nbr->state)    nbr->ts_last_progress = recent_relative_time ();  else /* regression in NSM */    {      nbr->ts_last_regress = recent_relative_time ();      nbr->last_regress_str = ospf_nsm_event_str [event];    }#ifdef HAVE_SNMP  /* Terminal state or regression */   if ((next_state == NSM_Full)       || (next_state == NSM_TwoWay)      || (next_state < nbr->state))    {      /* ospfVirtNbrStateChange */      if (nbr->oi->type == OSPF_IFTYPE_VIRTUALLINK)        ospfTrapVirtNbrStateChange(nbr);      /* ospfNbrStateChange trap  */      else	        /* To/From FULL, only managed by DR */        if (((next_state != NSM_Full) && (nbr->state != NSM_Full))             || (nbr->oi->state == ISM_DR))          ospfTrapNbrStateChange(nbr);    }#endif}

voidaddress_print(FILE *file, void *data){	ip_address_t *ipaddr = data;	char *broadcast = (char *) MALLOC(21);	char *addr_str = (char *) MALLOC(41);	if (IP_IS6(ipaddr)) {		inet_ntop(AF_INET6, &ipaddr->u.sin6_addr, addr_str, 41);	} else {		inet_ntop(AF_INET, &ipaddr->u.sin.sin_addr, addr_str, 41);	if (ipaddr->u.sin.sin_brd.s_addr)		snprintf(broadcast, 20, " brd %s",			 inet_ntop2(ipaddr->u.sin.sin_brd.s_addr));	}	fprintf(file, "     %s/%d%s dev %s scope %s%s%s/n"		, addr_str		, ipaddr->ifa.ifa_prefixlen		, broadcast		, IF_NAME(ipaddr->ifp)		, netlink_scope_n2a(ipaddr->ifa.ifa_scope)		, ipaddr->label ? " label " : ""		, ipaddr->label ? ipaddr->label : "");	FREE(broadcast);	FREE(addr_str);}

/* Delete specified OSPF neighbor from interface. */void ospf_nbr_delete(struct ospf_neighbor *nbr){	struct ospf_interface *oi;	struct route_node *rn;	struct prefix p;	oi = nbr->oi;	/* get appropriate prefix 'key' */	ospf_nbr_key(oi, nbr, &p);	rn = route_node_lookup(oi->nbrs, &p);	if (rn) {		/* If lookup for a NBR succeeds, the leaf route_node could		 * only exist because there is (or was) a nbr there.		 * If the nbr was deleted, the leaf route_node should have		 * lost its last refcount too, and be deleted.		 * Therefore a looked-up leaf route_node in nbrs table		 * should never have NULL info.		 */		assert(rn->info);		if (rn->info) {			rn->info = NULL;			route_unlock_node(rn);		} else			zlog_info("Can't find neighbor %s in the interface %s",				  inet_ntoa(nbr->src), IF_NAME(oi));		route_unlock_node(rn);	}	/* Free ospf_neighbor structure. */	ospf_nbr_free(nbr);}

voiddump_iproute(void *rt_data){	ip_route_t *route = rt_data;	char *log_msg = MALLOC(1024);	char *op = log_msg;	if (route->blackhole) {		strncat(log_msg, "blackhole ", 30);	}	if (route->dst)		op += snprintf(op, log_msg + 1024 - op, "%s/%d", ipaddresstos(NULL, route->dst), route->dmask);	if (route->gw)		op += snprintf(op, log_msg + 1024 - op, " gw %s", ipaddresstos(NULL, route->gw));	if (route->gw2)		op += snprintf(op, log_msg + 1024 - op, " or gw %s", ipaddresstos(NULL, route->gw2));	if (route->src)		op += snprintf(op, log_msg + 1024 - op, " src %s", ipaddresstos(NULL, route->src));	if (route->index)		op += snprintf(op, log_msg + 1024 - op, " dev %s",			 IF_NAME(if_get_by_ifindex(route->index)));	if (route->table)		op += snprintf(op, log_msg + 1024 - op, " table %d", route->table);	if (route->scope)		op += snprintf(op, log_msg + 1024 - op, " scope %s",			 netlink_scope_n2a(route->scope));	if (route->metric)		op += snprintf(op, log_msg + 1024 - op, " metric %d", route->metric);	log_message(LOG_INFO, "     %s", log_msg);	FREE(log_msg);}

static voidroute_print(FILE *file, void *data){	ip_route_t *route = data;	fprintf(file, "     ");	if (route->blackhole)		fprintf(file, "blackhole ");	if (route->dst)		fprintf(file, "%s/%d", ipaddresstos(NULL, route->dst), route->dmask);	if (route->gw)		fprintf(file, " gw %s", ipaddresstos(NULL, route->gw));	if (route->gw2)		fprintf(file, " or gw %s", ipaddresstos(NULL, route->gw2));	if (route->src)		fprintf(file, " src %s", ipaddresstos(NULL, route->src));	if (route->index)		fprintf(file, " dev %s", IF_NAME(if_get_by_ifindex(route->index)));	if (route->table)		fprintf(file, " table %d", route->table);	if (route->scope)		fprintf(file, " scope %s", netlink_scope_n2a(route->scope));	if (route->metric)		fprintf(file, " metric %d", route->metric);	fprintf(file, "/n");}

static voidaddress_print(FILE *file, void *data){	ip_address_t *ipaddr = data;	char broadcast[INET_ADDRSTRLEN + 5] = "";	/* allow for " brd " */	char addr_str[INET6_ADDRSTRLEN] = "";	if (IP_IS6(ipaddr)) {		inet_ntop(AF_INET6, &ipaddr->u.sin6_addr, addr_str, sizeof(addr_str));	} else {		inet_ntop(AF_INET, &ipaddr->u.sin.sin_addr, addr_str, sizeof(addr_str));	if (ipaddr->u.sin.sin_brd.s_addr)		snprintf(broadcast, sizeof(broadcast) - 1, " brd %s",			 inet_ntop2(ipaddr->u.sin.sin_brd.s_addr));	}	fprintf(file, "     %s/%d%s dev %s%s%s%s%s/n"		, addr_str		, ipaddr->ifa.ifa_prefixlen		, broadcast		, IF_NAME(ipaddr->ifp)		, IP_IS4(ipaddr) ? " scope " : ""		, IP_IS4(ipaddr) ? netlink_scope_n2a(ipaddr->ifa.ifa_scope) : ""		, ipaddr->label ? " label " : ""		, ipaddr->label ? ipaddr->label : "");}

/* Execute ISM event process. */intospf_ism_event (struct thread *thread){  int event;  int next_state;  struct ospf_interface *oi;  oi = THREAD_ARG (thread);  event = THREAD_VAL (thread);  /* Call function. */  next_state = (*(ISM [oi->state][event].func))(oi);  if (! next_state)    next_state = ISM [oi->state][event].next_state;  if (IS_DEBUG_OSPF (ism, ISM_EVENTS))    zlog (NULL, LOG_DEBUG, "ISM[%s]: %s (%s)", IF_NAME (oi),	  LOOKUP (ospf_ism_state_msg, oi->state),	  ospf_ism_event_str[event]);  /* If state is changed. */  if (next_state != oi->state)    ism_change_state (oi, next_state);  /* Make sure timer is set. */  ism_timer_set (oi);  return 0;}

static intnsm_kill_nbr (struct ospf_neighbor *nbr){  /* killing nbr_self is invalid */  if (nbr == nbr->oi->nbr_self)    {      assert (nbr != nbr->oi->nbr_self);      return 0;    }    if (nbr->oi->type == OSPF_IFTYPE_NBMA && nbr->nbr_nbma != NULL)    {      struct ospf_nbr_nbma *nbr_nbma = nbr->nbr_nbma;      nbr_nbma->nbr = NULL;      nbr_nbma->state_change = nbr->state_change;      nbr->nbr_nbma = NULL;      OSPF_POLL_TIMER_ON (nbr_nbma->t_poll, ospf_poll_timer,			  nbr_nbma->v_poll);      if (IS_DEBUG_OSPF (nsm, NSM_EVENTS))	zlog_debug ("NSM[%s:%s]: Down (PollIntervalTimer scheduled)",		   IF_NAME (nbr->oi), inet_ntoa (nbr->address.u.prefix4));      }  return 0;}

voiddump_iproute(void *rt_data){	ip_route_t *route = rt_data;	char *log_msg = MALLOC(1024);	char *tmp = MALLOC(INET6_ADDRSTRLEN + 30);	char *tmp_str;	if (route->blackhole) {		strncat(log_msg, "blackhole ", 30);	}	if (route->dst) {		tmp_str = ipaddresstos(route->dst);		snprintf(tmp, INET6_ADDRSTRLEN + 30, "%s/%d", tmp_str, route->dmask);		strncat(log_msg, tmp, INET6_ADDRSTRLEN + 30);		FREE(tmp_str);	}	if (route->gw) {		tmp_str = ipaddresstos(route->gw);		snprintf(tmp, INET6_ADDRSTRLEN + 30, " gw %s", tmp_str);		strncat(log_msg, tmp, INET6_ADDRSTRLEN + 30);		FREE(tmp_str);	}	if (route->gw2) {		tmp_str = ipaddresstos(route->gw2);		snprintf(tmp, INET6_ADDRSTRLEN + 30, " or gw %s", tmp_str);		strncat(log_msg, tmp, INET6_ADDRSTRLEN + 30);		FREE(tmp_str);	}	if (route->src) {		tmp_str = ipaddresstos(route->src);		snprintf(tmp, INET6_ADDRSTRLEN + 30, " src %s", tmp_str);		strncat(log_msg, tmp, INET6_ADDRSTRLEN + 30);		FREE(tmp_str);	}	if (route->index) {		snprintf(tmp, INET6_ADDRSTRLEN + 30, " dev %s",			 IF_NAME(if_get_by_ifindex(route->index)));		strncat(log_msg, tmp, INET6_ADDRSTRLEN + 30);	}	if (route->table) {		snprintf(tmp, INET6_ADDRSTRLEN + 30, " table %d", route->table);		strncat(log_msg, tmp, INET6_ADDRSTRLEN + 30);	}	if (route->scope) {		snprintf(tmp, INET6_ADDRSTRLEN + 30, " scope %s",			 netlink_scope_n2a(route->scope));		strncat(log_msg, tmp, INET6_ADDRSTRLEN + 30);	}	if (route->metric) {		snprintf(tmp, INET6_ADDRSTRLEN + 30, " metric %d", route->metric);		strncat(log_msg, tmp, INET6_ADDRSTRLEN + 30);	}	log_message(LOG_INFO, "     %s", log_msg);	FREE(tmp);	FREE(log_msg);}

static void vrrp_log_int_up(vrrp_t *vrrp){	if (IF_ISUP(vrrp->ifp))		log_message(LOG_INFO, "Kernel is reporting: interface %s UP",		       IF_NAME(vrrp->ifp));	if (!LIST_ISEMPTY(vrrp->track_ifp))		log_message(LOG_INFO, "Kernel is reporting: tracked interface are UP");}

static intism_ignore (struct ospf_interface *oi){  if (IS_DEBUG_OSPF (ism, ISM_EVENTS))    zlog (NULL, LOG_DEBUG, "ISM[%s]: ism_ignore called", IF_NAME (oi));  return 0;}

/* Log interface message */static void vrrp_log_int_down(vrrp_t *vrrp){	if (!IF_ISUP(vrrp->ifp))		log_message(LOG_INFO, "Kernel is reporting: interface %s DOWN",		       IF_NAME(vrrp->ifp));	if (!LIST_ISEMPTY(vrrp->track_ifp))		vrrp_log_tracked_down(vrrp->track_ifp);}

voidism_change_state (struct ospf_interface *oi, int state){  int old_state;  struct ospf_lsa *lsa;  /* Logging change of state. */  if (IS_DEBUG_OSPF (ism, ISM_STATUS))    zlog (NULL, LOG_DEBUG, "ISM[%s]: State change %s -> %s", IF_NAME (oi),	  LOOKUP (ospf_ism_state_msg, oi->state),	  LOOKUP (ospf_ism_state_msg, state));  old_state = oi->state;  oi->state = state;  oi->state_change++;  if (old_state == ISM_Down || state == ISM_Down)    ospf_check_abr_status (oi->ospf);  /* Originate router-LSA. */  if (oi->area)    {      if (state == ISM_Down)	{	  if (oi->area->act_ints > 0)	    oi->area->act_ints--;	}      else if (old_state == ISM_Down)	oi->area->act_ints++;      /* schedule router-LSA originate. */      ospf_router_lsa_timer_add (oi->area);    }  /* Originate network-LSA. */  if (old_state != ISM_DR && state == ISM_DR)    ospf_network_lsa_timer_add (oi);  else if (old_state == ISM_DR && state != ISM_DR)    {      /* Free self originated network LSA. */      lsa = oi->network_lsa_self;      if (lsa)	{	  ospf_lsa_flush_area (lsa, oi->area);	  OSPF_TIMER_OFF (oi->t_network_lsa_self);	}      ospf_lsa_unlock (oi->network_lsa_self);      oi->network_lsa_self = NULL;    }#ifdef HAVE_OPAQUE_LSA  ospf_opaque_ism_change (oi, old_state);#endif /* HAVE_OPAQUE_LSA */  /* Check area border status.  */  ospf_check_abr_status (oi->ospf);}

/* OSPF NSM functions. */intnsm_ignore (struct ospf_neighbor *nbr){  if (IS_DEBUG_OSPF (nsm, NSM_EVENTS))    zlog (NULL, LOG_DEBUG, "NSM[%s:%s]: nsm_ignore called",	  IF_NAME (nbr->oi), inet_ntoa (nbr->router_id));  return 0;}

voidroute_print(FILE *file, void *data){	ip_route_t *route = data;	char *msg = MALLOC(150);	char *tmp = MALLOC(30);	if (route->blackhole) {		strncat(msg, "blackhole ", 30);	}	if (route->dst) {		snprintf(tmp, 30, "%s/%d", ipaddresstos(route->dst),			route->dmask);		strncat(msg, tmp, 30);	}	if (route->gw) {		snprintf(tmp, 30, " gw %s", ipaddresstos(route->gw));		strncat(msg, tmp, 30);	}	if (route->gw2) {		snprintf(tmp, 30, " or gw %s", ipaddresstos(route->gw2));		strncat(msg, tmp, 30);	}	if (route->src) {		snprintf(tmp, 30, " src %s", ipaddresstos(route->src));		strncat(msg, tmp, 30);	}	if (route->index) {		snprintf(tmp, 30, " dev %s",		  IF_NAME(if_get_by_ifindex(route->index)));		strncat(msg, tmp, 30);	}	if (route->table) {		snprintf(tmp, 30, " table %d", route->table);		strncat(msg, tmp, 30);	}	if (route->scope) {		snprintf(tmp, 30, " scope %s",		  netlink_scope_n2a(route->scope));		strncat(msg, tmp, 30);	}	if (route->metric) {		snprintf(tmp, 30, " metric %d", route->metric);		strncat(msg, tmp, 30);	}	fprintf(file, "     %s/n", msg);	FREE(tmp);	FREE(msg);}

/* Log tracked interface down */voidvrrp_log_tracked_down(list l){	element e;	tracked_if *tip;	for (e = LIST_HEAD(l); e; ELEMENT_NEXT(e)) {		tip = ELEMENT_DATA(e);		if (!IF_ISUP(tip->ifp))			log_message(LOG_INFO, "Kernel is reporting: interface %s DOWN",			       IF_NAME(tip->ifp));	}}

static int ospf_wait_timer(struct thread *thread){	struct ospf_interface *oi;	oi = THREAD_ARG(thread);	oi->t_wait = NULL;	if (IS_DEBUG_OSPF(ism, ISM_TIMERS))		zlog(NULL, LOG_DEBUG, "ISM[%s]: Timer (Wait timer expire)",		     IF_NAME(oi));	OSPF_ISM_EVENT_SCHEDULE(oi, ISM_WaitTimer);	return 0;}

/* OSPF NSM Timer functions. */intospf_inactivity_timer (struct thread *thread){  struct ospf_neighbor *nbr;  nbr = THREAD_ARG (thread);  nbr->t_inactivity = NULL;  if (IS_DEBUG_OSPF (nsm, NSM_TIMERS))    zlog (NULL, LOG_DEBUG, "NSM[%s:%s]: Timer (Inactivity timer expire)",	  IF_NAME (nbr->oi), inet_ntoa (nbr->router_id));  OSPF_NSM_EVENT_SCHEDULE (nbr, NSM_InactivityTimer);  return 0;}

int ospf_hello_timer(struct thread *thread){	struct ospf_interface *oi;	oi = THREAD_ARG(thread);	oi->t_hello = NULL;	if (IS_DEBUG_OSPF(ism, ISM_TIMERS))		zlog(NULL, LOG_DEBUG, "ISM[%s]: Timer (Hello timer expire)",		     IF_NAME(oi));	/* Sending hello packet. */	ospf_hello_send(oi);	/* Hello timer set. */	OSPF_HELLO_TIMER_ON(oi);	return 0;}

static struct ospf_neighbor *ospf_nbr_add (struct ospf_interface *oi, struct ospf_header *ospfh,              struct prefix *p){  struct ospf_neighbor *nbr;    nbr = ospf_nbr_new (oi);  nbr->state = NSM_Down;  nbr->src = p->u.prefix4;  memcpy (&nbr->address, p, sizeof (struct prefix));  nbr->nbr_nbma = NULL;  if (oi->type == OSPF_IFTYPE_NBMA)    {      struct ospf_nbr_nbma *nbr_nbma;      struct listnode *node;      for (ALL_LIST_ELEMENTS_RO (oi->nbr_nbma, node, nbr_nbma))        {          if (IPV4_ADDR_SAME(&nbr_nbma->addr, &nbr->src))            {              nbr_nbma->nbr = nbr;              nbr->nbr_nbma = nbr_nbma;              if (nbr_nbma->t_poll)                OSPF_POLL_TIMER_OFF (nbr_nbma->t_poll);              nbr->state_change = nbr_nbma->state_change + 1;            }        }    }        /* New nbr, save the crypto sequence number if necessary */  if (ntohs (ospfh->auth_type) == OSPF_AUTH_CRYPTOGRAPHIC)    nbr->crypt_seqnum = ospfh->u.crypt.crypt_seqnum;    if (IS_DEBUG_OSPF_EVENT)    zlog_debug ("NSM[%s:%s]: start", IF_NAME (nbr->oi),               inet_ntoa (nbr->router_id));    return nbr;}

/* Send the gratuitous ARP message */static int send_arp(ip_address_t *ipaddress){	struct sockaddr_ll sll;	int len;	/* Build the dst device */	memset(&sll, 0, sizeof(sll));	sll.sll_family = AF_PACKET;	memcpy(sll.sll_addr, IF_HWADDR(ipaddress->ifp), ETH_ALEN);	sll.sll_halen = ETHERNET_HW_LEN;	sll.sll_ifindex = IF_INDEX(ipaddress->ifp);	/* Send packet */	len = sendto(garp_fd, garp_buffer, sizeof(arphdr_t) + ETHER_HDR_LEN		     , 0, (struct sockaddr *)&sll, sizeof(sll));	if (len < 0)		log_message(LOG_INFO, "Error sending gratuitous ARP on %s for %s",			    IF_NAME(ipaddress->ifp), inet_ntop2(ipaddress->u.sin.sin_addr.s_addr));	return len;}

voiddump_ipaddress(void *if_data){	ip_address_t *ipaddr = if_data;	char broadcast[INET_ADDRSTRLEN + 5] = "";	if (!IP_IS6(ipaddr) && ipaddr->u.sin.sin_brd.s_addr) {		snprintf(broadcast, 21, " brd %s",			 inet_ntop2(ipaddr->u.sin.sin_brd.s_addr));	}	log_message(LOG_INFO, "     %s/%d%s dev %s scope %s%s%s"			    , ipaddresstos(NULL, ipaddr)			    , ipaddr->ifa.ifa_prefixlen			    , broadcast			    , IF_NAME(ipaddr->ifp)			    , get_rttables_scope(ipaddr->ifa.ifa_scope)			    , ipaddr->label ? " label " : ""			    , ipaddr->label ? ipaddr->label : "");}

static intospf_db_desc_timer (struct thread *thread){  struct ospf_neighbor *nbr;  nbr = THREAD_ARG (thread);  nbr->t_db_desc = NULL;  if (IS_DEBUG_OSPF (nsm, NSM_TIMERS))    zlog (NULL, LOG_DEBUG, "NSM[%s:%s]: Timer (DD Retransmit timer expire)",	  IF_NAME (nbr->oi), inet_ntoa (nbr->src));  /* resent last send DD packet. */  assert (nbr->last_send);  ospf_db_desc_resend (nbr);  /* DD Retransmit timer set. */  OSPF_NSM_TIMER_ON (nbr->t_db_desc, ospf_db_desc_timer, nbr->v_db_desc);  return 0;}

voidnsm_change_state (struct ospf_neighbor *nbr, int state){  struct ospf_interface *oi = nbr->oi;  struct ospf_area *vl_area = NULL;  u_char old_state;  int x;  int force = 1;    /* Logging change of status. */  if (IS_DEBUG_OSPF (nsm, NSM_STATUS))    zlog_debug ("NSM[%s:%s]: State change %s -> %s",	       IF_NAME (nbr->oi), inet_ntoa (nbr->router_id),	       LOOKUP (ospf_nsm_state_msg, nbr->state),	       LOOKUP (ospf_nsm_state_msg, state));  /* Preserve old status. */  old_state = nbr->state;  /* Change to new status. */  nbr->state = state;  /* Statistics. */  nbr->state_change++;  if (oi->type == OSPF_IFTYPE_VIRTUALLINK)    vl_area = ospf_area_lookup_by_area_id (oi->ospf, oi->vl_data->vl_area_id);    /* One of the neighboring routers changes to/from the FULL state. */  if ((old_state != NSM_Full && state == NSM_Full) ||      (old_state == NSM_Full && state != NSM_Full))    {      if (state == NSM_Full)	{	  oi->full_nbrs++;	  oi->area->full_nbrs++;          ospf_check_abr_status (oi->ospf);	  if (oi->type == OSPF_IFTYPE_VIRTUALLINK && vl_area)            if (++vl_area->full_vls == 1)	      ospf_schedule_abr_task (oi->ospf);	  /* kevinm: refresh any redistributions */	  for (x = ZEBRA_ROUTE_SYSTEM; x < ZEBRA_ROUTE_MAX; x++)	    {	      if (x == ZEBRA_ROUTE_OSPF || x == ZEBRA_ROUTE_OSPF6)		continue;	      ospf_external_lsa_refresh_type (oi->ospf, x, force);	    }	}      else	{	  oi->full_nbrs--;	  oi->area->full_nbrs--;          ospf_check_abr_status (oi->ospf);	  if (oi->type == OSPF_IFTYPE_VIRTUALLINK && vl_area)	    if (vl_area->full_vls > 0)	      if (--vl_area->full_vls == 0)		ospf_schedule_abr_task (oi->ospf);           /* clear neighbor retransmit list */          if (!ospf_ls_retransmit_isempty (nbr))            ospf_ls_retransmit_clear (nbr);	}      zlog_info ("nsm_change_state(%s, %s -> %s): "		 "scheduling new router-LSA origination",		 inet_ntoa (nbr->router_id),		 LOOKUP(ospf_nsm_state_msg, old_state),		 LOOKUP(ospf_nsm_state_msg, state));      ospf_router_lsa_timer_add (oi->area);      if (oi->type == OSPF_IFTYPE_VIRTUALLINK)	{	  struct ospf_area *vl_area =	    ospf_area_lookup_by_area_id (oi->ospf, oi->vl_data->vl_area_id);	  	  if (vl_area)	    ospf_router_lsa_timer_add (vl_area);	}      /* Originate network-LSA. */      if (oi->state == ISM_DR)	{	  if (oi->network_lsa_self && oi->full_nbrs == 0)	    {	      ospf_lsa_flush_area (oi->network_lsa_self, oi->area);	      ospf_lsa_unlock (oi->network_lsa_self);	      oi->network_lsa_self = NULL;	      OSPF_TIMER_OFF (oi->t_network_lsa_self);	    }	  else	    ospf_network_lsa_timer_add (oi);	}    }//.........这里部分代码省略.........

static voidism_change_state (struct ospf_interface *oi, int state){  int old_state;  struct ospf_lsa *lsa;  /* Logging change of state. */  if (IS_DEBUG_OSPF (ism, ISM_STATUS))    zlog (NULL, LOG_DEBUG, "ISM[%s]: State change %s -> %s", IF_NAME (oi),	  LOOKUP (ospf_ism_state_msg, oi->state),	  LOOKUP (ospf_ism_state_msg, state));  old_state = oi->state;  oi->state = state;  oi->state_change++;#ifdef HAVE_SNMP  /* Terminal state or regression */   if ((state == ISM_DR) || (state == ISM_Backup) || (state == ISM_DROther) ||      (state == ISM_PointToPoint) || (state < old_state))    {      /* ospfVirtIfStateChange */      if (oi->type == OSPF_IFTYPE_VIRTUALLINK)        ospfTrapVirtIfStateChange (oi);      /* ospfIfStateChange */      else        ospfTrapIfStateChange (oi);    }#endif  /* Set multicast memberships appropriately for new state. */  ospf_if_set_multicast(oi);  if (old_state == ISM_Down || state == ISM_Down)    ospf_check_abr_status (oi->ospf);  /* Originate router-LSA. */  if (state == ISM_Down)    {      if (oi->area->act_ints > 0)        oi->area->act_ints--;    }  else if (old_state == ISM_Down)    oi->area->act_ints++;  /* schedule router-LSA originate. */  ospf_router_lsa_update_area (oi->area);  /* Originate network-LSA. */  if (old_state != ISM_DR && state == ISM_DR)    ospf_network_lsa_update (oi);  else if (old_state == ISM_DR && state != ISM_DR)    {      /* Free self originated network LSA. */      lsa = oi->network_lsa_self;      if (lsa)        ospf_lsa_flush_area (lsa, oi->area);      ospf_lsa_unlock (&oi->network_lsa_self);      oi->network_lsa_self = NULL;    }  ospf_opaque_ism_change (oi, old_state);  /* Check area border status.  */  ospf_check_abr_status (oi->ospf);}