proto.c 46 KB
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/*
 *	BIRD -- Protocols
 *
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 *	(c) 1998--2000 Martin Mares <mj@ucw.cz>
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 *
 *	Can be freely distributed and used under the terms of the GNU GPL.
 */

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#undef LOCAL_DEBUG
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#include "nest/bird.h"
#include "nest/protocol.h"
#include "lib/resource.h"
#include "lib/lists.h"
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#include "lib/event.h"
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#include "lib/timer.h"
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#include "lib/string.h"
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#include "conf/conf.h"
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#include "nest/route.h"
#include "nest/iface.h"
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#include "nest/cli.h"
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#include "filter/filter.h"
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pool *proto_pool;
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list  proto_list;
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static list protocol_list;
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struct protocol *class_to_protocol[PROTOCOL__MAX];
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#define PD(pr, msg, args...) do { if (pr->debug & D_STATES) { log(L_TRACE "%s: " msg, pr->name , ## args); } } while(0)

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static timer *proto_shutdown_timer;
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static timer *gr_wait_timer;

#define GRS_NONE	0
#define GRS_INIT	1
#define GRS_ACTIVE	2
#define GRS_DONE	3

static int graceful_restart_state;
static u32 graceful_restart_locks;
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static char *p_states[] = { "DOWN", "START", "UP", "STOP" };
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static char *c_states[] = { "DOWN", "START", "UP", "FLUSHING" };
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extern struct protocol proto_unix_iface;

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static void proto_shutdown_loop(timer *);
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static void proto_rethink_goal(struct proto *p);
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static char *proto_state_name(struct proto *p);
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static void channel_verify_limits(struct channel *c);
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static inline void channel_reset_limit(struct channel_limit *l);
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static inline int proto_is_done(struct proto *p)
{ return (p->proto_state == PS_DOWN) && (p->active_channels == 0); }
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static inline int channel_is_active(struct channel *c)
{ return (c->channel_state == CS_START) || (c->channel_state == CS_UP); }
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static void
proto_log_state_change(struct proto *p)
{
  if (p->debug & D_STATES)
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  {
    char *name = proto_state_name(p);
    if (name != p->last_state_name_announced)
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    {
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      p->last_state_name_announced = name;
      PD(p, "State changed to %s", proto_state_name(p));
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    }
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  }
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  else
    p->last_state_name_announced = NULL;
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}
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struct channel_config *
proto_cf_find_channel(struct proto_config *pc, uint net_type)
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{
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  struct channel_config *cc;

  WALK_LIST(cc, pc->channels)
    if (cc->net_type == net_type)
      return cc;

  return NULL;
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}

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/**
 * proto_find_channel_by_table - find channel connected to a routing table
 * @p: protocol instance
 * @t: routing table
 *
 * Returns pointer to channel or NULL
 */
struct channel *
proto_find_channel_by_table(struct proto *p, struct rtable *t)
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{
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  struct channel *c;
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  WALK_LIST(c, p->channels)
    if (c->table == t)
      return c;
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  return NULL;
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}

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/**
 * proto_find_channel_by_name - find channel by its name
 * @p: protocol instance
 * @n: channel name
 *
 * Returns pointer to channel or NULL
 */
struct channel *
proto_find_channel_by_name(struct proto *p, const char *n)
{
  struct channel *c;

  WALK_LIST(c, p->channels)
    if (!strcmp(c->name, n))
      return c;

  return NULL;
}

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/**
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 * proto_add_channel - connect protocol to a routing table
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 * @p: protocol instance
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 * @cf: channel configuration
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 *
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 * This function creates a channel between the protocol instance @p and the
 * routing table specified in the configuration @cf, making the protocol hear
 * all changes in the table and allowing the protocol to update routes in the
 * table.
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 *
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 * The channel is linked in the protocol channel list and when active also in
 * the table channel list. Channels are allocated from the global resource pool
 * (@proto_pool) and they are automatically freed when the protocol is removed.
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 */
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struct channel *
proto_add_channel(struct proto *p, struct channel_config *cf)
{
  struct channel *c = mb_allocz(proto_pool, cf->channel->channel_size);

  c->name = cf->name;
  c->channel = cf->channel;
  c->proto = p;
  c->table = cf->table->table;

  c->in_filter = cf->in_filter;
  c->out_filter = cf->out_filter;
  c->rx_limit = cf->rx_limit;
  c->in_limit = cf->in_limit;
  c->out_limit = cf->out_limit;

  c->net_type = cf->net_type;
  c->ra_mode = cf->ra_mode;
  c->preference = cf->preference;
  c->merge_limit = cf->merge_limit;
  c->in_keep_filtered = cf->in_keep_filtered;

  c->channel_state = CS_DOWN;
  c->export_state = ES_DOWN;
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  c->last_state_change = current_time();
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  c->last_tx_filter_change = current_time();
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  c->reloadable = 1;

  CALL(c->channel->init, c, cf);

  add_tail(&p->channels, &c->n);

  PD(p, "Channel %s connected to table %s", c->name, c->table->name);

  return c;
}

void
proto_remove_channel(struct proto *p, struct channel *c)
{
  ASSERT(c->channel_state == CS_DOWN);

  PD(p, "Channel %s removed", c->name);

  rem_node(&c->n);
  mb_free(c);
}


static void
proto_start_channels(struct proto *p)
{
  struct channel *c;
  WALK_LIST(c, p->channels)
    if (!c->disabled)
      channel_set_state(c, CS_UP);
}

static void
proto_pause_channels(struct proto *p)
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{
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  struct channel *c;
  WALK_LIST(c, p->channels)
    if (!c->disabled && channel_is_active(c))
      channel_set_state(c, CS_START);
}
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static void
proto_stop_channels(struct proto *p)
{
  struct channel *c;
  WALK_LIST(c, p->channels)
    if (!c->disabled && channel_is_active(c))
      channel_set_state(c, CS_FLUSHING);
}
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static void
proto_remove_channels(struct proto *p)
{
  struct channel *c;
  WALK_LIST_FIRST(c, p->channels)
    proto_remove_channel(p, c);
}

static void
channel_schedule_feed(struct channel *c, int initial)
{
  // DBG("%s: Scheduling meal\n", p->name);
  ASSERT(c->channel_state == CS_UP);
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  c->export_state = ES_FEEDING;
  c->refeeding = !initial;
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  ev_schedule(c->feed_event);
}

static void
channel_feed_loop(void *ptr)
{
  struct channel *c = ptr;

  if (c->export_state != ES_FEEDING)
    return;

  if (!c->feed_active)
    if (c->proto->feed_begin)
      c->proto->feed_begin(c, !c->refeeding);

  // DBG("Feeding protocol %s continued\n", p->name);
  if (!rt_feed_channel(c))
  {
    ev_schedule(c->feed_event);
    return;
  }

  // DBG("Feeding protocol %s finished\n", p->name);
  c->export_state = ES_READY;
  // proto_log_state_change(p);

  if (c->proto->feed_end)
    c->proto->feed_end(c);
}


static void
channel_start_export(struct channel *c)
{
  ASSERT(c->channel_state == CS_UP);
  ASSERT(c->export_state == ES_DOWN);

  channel_schedule_feed(c, 1);	/* Sets ES_FEEDING */
}

static void
channel_stop_export(struct channel *c)
{
  /* Need to abort feeding */
  if (c->export_state == ES_FEEDING)
    rt_feed_channel_abort(c);

  c->export_state = ES_DOWN;
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  c->stats.exp_routes = 0;
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}

static void
channel_do_start(struct channel *c)
{
  rt_lock_table(c->table);
  add_tail(&c->table->channels, &c->table_node);
  c->proto->active_channels++;

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  c->feed_event = ev_new_init(c->proto->pool, channel_feed_loop, c);
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  channel_reset_limit(&c->rx_limit);
  channel_reset_limit(&c->in_limit);
  channel_reset_limit(&c->out_limit);

  CALL(c->channel->start, c);
}

static void
channel_do_flush(struct channel *c)
{
  rt_schedule_prune(c->table);

  c->gr_wait = 0;
  if (c->gr_lock)
    channel_graceful_restart_unlock(c);

  CALL(c->channel->shutdown, c);
}

static void
channel_do_down(struct channel *c)
{
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  rem_node(&c->table_node);
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  rt_unlock_table(c->table);
  c->proto->active_channels--;

  if ((c->stats.imp_routes + c->stats.filt_routes) != 0)
    log(L_ERR "%s: Channel %s is down but still has some routes", c->proto->name, c->name);

  memset(&c->stats, 0, sizeof(struct proto_stats));

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  CALL(c->channel->cleanup, c);

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  /* Schedule protocol shutddown */
  if (proto_is_done(c->proto))
    ev_schedule(c->proto->event);
}

void
channel_set_state(struct channel *c, uint state)
{
  uint cs = c->channel_state;
  uint es = c->export_state;

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  DBG("%s reporting channel %s state transition %s -> %s\n", c->proto->name, c->name, c_states[cs], c_states[state]);
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  if (state == cs)
    return;

  c->channel_state = state;
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  c->last_state_change = current_time();
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  switch (state)
  {
  case CS_START:
    ASSERT(cs == CS_DOWN || cs == CS_UP);

    if (cs == CS_DOWN)
      channel_do_start(c);

    if (es != ES_DOWN)
      channel_stop_export(c);

    break;

  case CS_UP:
    ASSERT(cs == CS_DOWN || cs == CS_START);

    if (cs == CS_DOWN)
      channel_do_start(c);

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    if (!c->gr_wait && c->proto->rt_notify)
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      channel_start_export(c);

    break;

  case CS_FLUSHING:
    ASSERT(cs == CS_START || cs == CS_UP);

    if (es != ES_DOWN)
      channel_stop_export(c);

    channel_do_flush(c);
    break;

  case CS_DOWN:
    ASSERT(cs == CS_FLUSHING);

    channel_do_down(c);
    break;

  default:
    ASSERT(0);
  }
  // XXXX proto_log_state_change(c);
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}

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/**
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 * channel_request_feeding - request feeding routes to the channel
 * @c: given channel
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 *
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 * Sometimes it is needed to send again all routes to the channel. This is
 * called feeding and can be requested by this function. This would cause
 * channel export state transition to ES_FEEDING (during feeding) and when
 * completed, it will switch back to ES_READY. This function can be called
 * even when feeding is already running, in that case it is restarted.
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 */
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void
channel_request_feeding(struct channel *c)
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{
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  ASSERT(c->channel_state == CS_UP);
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  /* Do nothing if we are still waiting for feeding */
  if (c->export_state == ES_DOWN)
    return;
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  /* If we are already feeding, we want to restart it */
  if (c->export_state == ES_FEEDING)
  {
    /* Unless feeding is in initial state */
    if (!c->feed_active)
	return;

    rt_feed_channel_abort(c);
  }

  channel_reset_limit(&c->out_limit);

  /* Hack: reset exp_routes during refeed, and do not decrease it later */
  c->stats.exp_routes = 0;

  channel_schedule_feed(c, 0);	/* Sets ES_FEEDING */
  // proto_log_state_change(c);
}

static inline int
channel_reloadable(struct channel *c)
{
  return c->proto->reload_routes && c->reloadable;
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}

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static void
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channel_request_reload(struct channel *c)
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{
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  ASSERT(c->channel_state == CS_UP);
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  ASSERT(channel_reloadable(c));
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  c->proto->reload_routes(c);
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  /*
   * Should this be done before reload_routes() hook?
   * Perhaps, but routes are updated asynchronously.
   */
  channel_reset_limit(&c->rx_limit);
  channel_reset_limit(&c->in_limit);
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}

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const struct channel_class channel_basic = {
  .channel_size = sizeof(struct channel),
  .config_size = sizeof(struct channel_config)
};

void *
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channel_config_new(const struct channel_class *cc, const char *name, uint net_type, struct proto_config *proto)
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{
  struct channel_config *cf = NULL;
  struct rtable_config *tab = NULL;

  if (net_type)
  {
    if (!net_val_match(net_type, proto->protocol->channel_mask))
      cf_error("Unsupported channel type");

    if (proto->net_type && (net_type != proto->net_type))
      cf_error("Different channel type");

    tab = new_config->def_tables[net_type];
  }

  if (!cc)
    cc = &channel_basic;

  cf = cfg_allocz(cc->config_size);
  cf->name = name;
  cf->channel = cc;
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  cf->parent = proto;
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  cf->table = tab;
  cf->out_filter = FILTER_REJECT;

  cf->net_type = net_type;
  cf->ra_mode = RA_OPTIMAL;
  cf->preference = proto->protocol->preference;

  add_tail(&proto->channels, &cf->n);

  return cf;
}

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void *
channel_config_get(const struct channel_class *cc, const char *name, uint net_type, struct proto_config *proto)
{
  struct channel_config *cf;

  /* We are using name as token, so no strcmp() */
  WALK_LIST(cf, proto->channels)
    if (cf->name == name)
    {
      /* Allow to redefine channel only if inherited from template */
      if (cf->parent == proto)
	cf_error("Multiple %s channels", name);

      cf->parent = proto;
      return cf;
    }

  return channel_config_new(cc, name, net_type, proto);
}

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struct channel_config *
channel_copy_config(struct channel_config *src, struct proto_config *proto)
{
  struct channel_config *dst = cfg_alloc(src->channel->config_size);

  memcpy(dst, src, src->channel->config_size);
  add_tail(&proto->channels, &dst->n);
  CALL(src->channel->copy_config, dst, src);

  return dst;
}


static int reconfigure_type;  /* Hack to propagate type info to channel_reconfigure() */

int
channel_reconfigure(struct channel *c, struct channel_config *cf)
{
  /* FIXME: better handle these changes, also handle in_keep_filtered */
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  if ((c->table != cf->table->table) || (cf->ra_mode && (c->ra_mode != cf->ra_mode)))
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    return 0;

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  /* Note that filter_same() requires arguments in (new, old) order */
  int import_changed = !filter_same(cf->in_filter, c->in_filter);
  int export_changed = !filter_same(cf->out_filter, c->out_filter);
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  if (c->preference != cf->preference)
    import_changed = 1;

  if (c->merge_limit != cf->merge_limit)
    export_changed = 1;

  /* Reconfigure channel fields */
  c->in_filter = cf->in_filter;
  c->out_filter = cf->out_filter;
  c->rx_limit = cf->rx_limit;
  c->in_limit = cf->in_limit;
  c->out_limit = cf->out_limit;

  // c->ra_mode = cf->ra_mode;
  c->merge_limit = cf->merge_limit;
  c->preference = cf->preference;
  c->in_keep_filtered = cf->in_keep_filtered;

  channel_verify_limits(c);

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  if (export_changed)
    c->last_tx_filter_change = current_time();

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  /* Execute channel-specific reconfigure hook */
  if (c->channel->reconfigure && !c->channel->reconfigure(c, cf))
    return 0;
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  /* If the channel is not open, it has no routes and we cannot reload it anyways */
  if (c->channel_state != CS_UP)
    return 1;

  if (reconfigure_type == RECONFIG_SOFT)
  {
    if (import_changed)
      log(L_INFO "Channel %s.%s changed import", c->proto->name, c->name);

    if (export_changed)
      log(L_INFO "Channel %s.%s changed export", c->proto->name, c->name);

    return 1;
  }

  /* Route reload may be not supported */
  if (import_changed && !channel_reloadable(c))
    return 0;

  if (import_changed || export_changed)
    log(L_INFO "Reloading channel %s.%s", c->proto->name, c->name);

  if (import_changed)
    channel_request_reload(c);

  if (export_changed)
    channel_request_feeding(c);

  return 1;
}


int
proto_configure_channel(struct proto *p, struct channel **pc, struct channel_config *cf)
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{
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  struct channel *c = *pc;
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  if (!c && cf)
  {
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    /* We could add the channel, but currently it would just stay in down state
       until protocol is restarted, so it is better to force restart anyways. */
    log(L_INFO "Cannot add channel %s.%s", p->name, cf->name);
    return 0;
    // *pc = proto_add_channel(p, cf);
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  }
  else if (c && !cf)
  {
    if (c->channel_state != CS_DOWN)
    {
      log(L_INFO "Cannot remove channel %s.%s", c->proto->name, c->name);
      return 0;
    }

    proto_remove_channel(p, c);
    *pc = NULL;
  }
  else if (c && cf)
  {
    if (!channel_reconfigure(c, cf))
    {
      log(L_INFO "Cannot reconfigure channel %s.%s", c->proto->name, c->name);
      return 0;
    }
  }

  return 1;
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}

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static void
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proto_event(void *ptr)
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{
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  struct proto *p = ptr;

  if (p->do_start)
  {
    if_feed_baby(p);
    p->do_start = 0;
  }
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  if (p->do_stop)
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  {
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    if (p->proto == &proto_unix_iface)
      if_flush_ifaces(p);
    p->do_stop = 0;
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  }

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  if (proto_is_done(p))
  {
    if (p->proto->cleanup)
      p->proto->cleanup(p);

    p->active = 0;
    proto_log_state_change(p);
    proto_rethink_goal(p);
  }
}


/**
 * proto_new - create a new protocol instance
 * @c: protocol configuration
 *
 * When a new configuration has been read in, the core code starts
 * initializing all the protocol instances configured by calling their
 * init() hooks with the corresponding instance configuration. The initialization
 * code of the protocol is expected to create a new instance according to the
 * configuration by calling this function and then modifying the default settings
 * to values wanted by the protocol.
 */
void *
proto_new(struct proto_config *cf)
{
  struct proto *p = mb_allocz(proto_pool, cf->protocol->proto_size);

  p->cf = cf;
  p->debug = cf->debug;
  p->mrtdump = cf->mrtdump;
  p->name = cf->name;
  p->proto = cf->protocol;
  p->net_type = cf->net_type;
  p->disabled = cf->disabled;
  p->hash_key = random_u32();
  cf->proto = p;

  init_list(&p->channels);

  return p;
}

static struct proto *
proto_init(struct proto_config *c, node *n)
{
  struct protocol *pr = c->protocol;
  struct proto *p = pr->init(c);

  p->proto_state = PS_DOWN;
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  p->last_state_change = current_time();
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  p->vrf = c->vrf;
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  insert_node(&p->n, n);

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  p->event = ev_new_init(proto_pool, proto_event, p);
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  PD(p, "Initializing%s", p->disabled ? " [disabled]" : "");

  return p;
}

static void
proto_start(struct proto *p)
{
  /* Here we cannot use p->cf->name since it won't survive reconfiguration */
  p->pool = rp_new(proto_pool, p->proto->name);

  if (graceful_restart_state == GRS_INIT)
    p->gr_recovery = 1;
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}

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/**
 * proto_config_new - create a new protocol configuration
 * @pr: protocol the configuration will belong to
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 * @class: SYM_PROTO or SYM_TEMPLATE
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 *
 * Whenever the configuration file says that a new instance
 * of a routing protocol should be created, the parser calls
 * proto_config_new() to create a configuration entry for this
 * instance (a structure staring with the &proto_config header
 * containing all the generic items followed by protocol-specific
 * ones). Also, the configuration entry gets added to the list
 * of protocol instances kept in the configuration.
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 *
 * The function is also used to create protocol templates (when class
 * SYM_TEMPLATE is specified), the only difference is that templates
 * are not added to the list of protocol instances and therefore not
 * initialized during protos_commit()).
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 */
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void *
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proto_config_new(struct protocol *pr, int class)
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{
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  struct proto_config *cf = cfg_allocz(pr->config_size);
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  if (class == SYM_PROTO)
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    add_tail(&new_config->protos, &cf->n);

  cf->global = new_config;
  cf->protocol = pr;
  cf->name = pr->name;
  cf->class = class;
  cf->debug = new_config->proto_default_debug;
  cf->mrtdump = new_config->proto_default_mrtdump;

  init_list(&cf->channels);

  return cf;
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}

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/**
 * proto_copy_config - copy a protocol configuration
 * @dest: destination protocol configuration
 * @src: source protocol configuration
 *
 * Whenever a new instance of a routing protocol is created from the
 * template, proto_copy_config() is called to copy a content of
 * the source protocol configuration to the new protocol configuration.
 * Name, class and a node in protos list of @dest are kept intact.
 * copy_config() protocol hook is used to copy protocol-specific data.
 */
void
proto_copy_config(struct proto_config *dest, struct proto_config *src)
{
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  struct channel_config *cc;
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  node old_node;
  int old_class;
  char *old_name;

  if (dest->protocol != src->protocol)
    cf_error("Can't copy configuration from a different protocol type");

  if (dest->protocol->copy_config == NULL)
    cf_error("Inheriting configuration for %s is not supported", src->protocol->name);

  DBG("Copying configuration from %s to %s\n", src->name, dest->name);

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  /*
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   * Copy struct proto_config here. Keep original node, class and name.
   * protocol-specific config copy is handled by protocol copy_config() hook
   */

  old_node = dest->n;
  old_class = dest->class;
  old_name = dest->name;

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  memcpy(dest, src, src->protocol->config_size);
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  dest->n = old_node;
  dest->class = old_class;
  dest->name = old_name;
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  init_list(&dest->channels);
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  WALK_LIST(cc, src->channels)
    channel_copy_config(cc, dest);

  /* FIXME: allow for undefined copy_config */
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  dest->protocol->copy_config(dest, src);
}

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/**
 * protos_preconfig - pre-configuration processing
 * @c: new configuration
 *
 * This function calls the preconfig() hooks of all routing
 * protocols available to prepare them for reading of the new
 * configuration.
 */
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void
823
protos_preconfig(struct config *c)
824
{
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  struct protocol *p;

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  init_list(&c->protos);
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  DBG("Protocol preconfig:");
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  WALK_LIST(p, protocol_list)
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  {
    DBG(" %s", p->name);
    p->name_counter = 0;
    if (p->preconfig)
      p->preconfig(p, c);
  }
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  DBG("\n");
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}

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static int
proto_reconfigure(struct proto *p, struct proto_config *oc, struct proto_config *nc, int type)
{
  /* If the protocol is DOWN, we just restart it */
  if (p->proto_state == PS_DOWN)
    return 0;

  /* If there is a too big change in core attributes, ... */
  if ((nc->protocol != oc->protocol) ||
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      (nc->net_type != oc->net_type) ||
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      (nc->disabled != p->disabled) ||
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      (nc->vrf != oc->vrf))
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    return 0;

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  p->name = nc->name;
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  p->debug = nc->debug;
  p->mrtdump = nc->mrtdump;
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  reconfigure_type = type;
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  /* Execute protocol specific reconfigure hook */
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  if (!p->proto->reconfigure || !p->proto->reconfigure(p, nc))
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    return 0;

  DBG("\t%s: same\n", oc->name);
  PD(p, "Reconfigured");
  p->cf = nc;

  return 1;
}

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/**
 * protos_commit - commit new protocol configuration
 * @new: new configuration
 * @old: old configuration or %NULL if it's boot time config
 * @force_reconfig: force restart of all protocols (used for example
 * when the router ID changes)
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 * @type: type of reconfiguration (RECONFIG_SOFT or RECONFIG_HARD)
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 *
 * Scan differences between @old and @new configuration and adjust all
 * protocol instances to conform to the new configuration.
 *
 * When a protocol exists in the new configuration, but it doesn't in the
 * original one, it's immediately started. When a collision with the other
 * running protocol would arise, the new protocol will be temporarily stopped
 * by the locking mechanism.
 *
 * When a protocol exists in the old configuration, but it doesn't in the
 * new one, it's shut down and deleted after the shutdown completes.
 *
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 * When a protocol exists in both configurations, the core decides
 * whether it's possible to reconfigure it dynamically - it checks all
 * the core properties of the protocol (changes in filters are ignored
 * if type is RECONFIG_SOFT) and if they match, it asks the
 * reconfigure() hook of the protocol to see if the protocol is able
 * to switch to the new configuration.  If it isn't possible, the
 * protocol is shut down and a new instance is started with the new
 * configuration after the shutdown is completed.
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 */
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void
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protos_commit(struct config *new, struct config *old, int force_reconfig, int type)
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{
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  struct proto_config *oc, *nc;
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  struct symbol *sym;
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  struct proto *p;
  node *n;

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  DBG("protos_commit:\n");
  if (old)
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  {
    WALK_LIST(oc, old->protos)
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    {
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      p = oc->proto;
      sym = cf_find_symbol(new, oc->name);
      if (sym && sym->class == SYM_PROTO && !new->shutdown)
      {
	/* Found match, let's check if we can smoothly switch to new configuration */
	/* No need to check description */
	nc = sym->def;
	nc->proto = p;

	/* We will try to reconfigure protocol p */
	if (! force_reconfig && proto_reconfigure(p, oc, nc, type))
	  continue;

	/* Unsuccessful, we will restart it */
	if (!p->disabled && !nc->disabled)
	  log(L_INFO "Restarting protocol %s", p->name);
	else if (p->disabled && !nc->disabled)
	  log(L_INFO "Enabling protocol %s", p->name);
	else if (!p->disabled && nc->disabled)
	  log(L_INFO "Disabling protocol %s", p->name);

	p->down_code = nc->disabled ? PDC_CF_DISABLE : PDC_CF_RESTART;
	p->cf_new = nc;
      }
      else if (!new->shutdown)
      {
	log(L_INFO "Removing protocol %s", p->name);
	p->down_code = PDC_CF_REMOVE;
	p->cf_new = NULL;
      }
      else /* global shutdown */
      {
	p->down_code = PDC_CMD_SHUTDOWN;
	p->cf_new = NULL;
      }

      p->reconfiguring = 1;
      config_add_obstacle(old);
      proto_rethink_goal(p);
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    }
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  }

  struct proto *first_dev_proto = NULL;
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  n = NODE &(proto_list.head);
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  WALK_LIST(nc, new->protos)
    if (!nc->proto)
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    {
      /* Not a first-time configuration */
      if (old)
	log(L_INFO "Adding protocol %s", nc->name);

      p = proto_init(nc, n);
      n = NODE p;

      if (p->proto == &proto_unix_iface)
	first_dev_proto = p;
    }
    else
      n = NODE nc->proto;
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  DBG("Protocol start\n");
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  /* Start device protocol first */
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  if (first_dev_proto)
    proto_rethink_goal(first_dev_proto);
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  /* Determine router ID for the first time - it has to be here and not in
     global_commit() because it is postponed after start of device protocol */
  if (!config->router_id)
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  {
    config->router_id = if_choose_router_id(config->router_id_from, 0);
    if (!config->router_id)
      die("Cannot determine router ID, please configure it manually");
  }
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  /* Start all new protocols */
  WALK_LIST_DELSAFE(p, n, proto_list)
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    proto_rethink_goal(p);
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}

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static void
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proto_rethink_goal(struct proto *p)
994
{
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  struct protocol *q;
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  byte goal;
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  if (p->reconfiguring && !p->active)
  {
    struct proto_config *nc = p->cf_new;
    node *n = p->n.prev;
    DBG("%s has shut down for reconfiguration\n", p->name);
    p->cf->proto = NULL;
    config_del_obstacle(p->cf->global);
    proto_remove_channels(p);
    rem_node(&p->n);
    rfree(p->event);
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    mb_free(p->message);
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    mb_free(p);
    if (!nc)
      return;
    p = proto_init(nc, n);
  }
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  /* Determine what state we want to reach */
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  if (p->disabled || p->reconfiguring)
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    goal = PS_DOWN;
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  else
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    goal = PS_UP;
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  q = p->proto;
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  if (goal == PS_UP)
  {
    if (!p->active)
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    {
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      /* Going up */
      DBG("Kicking %s up\n", p->name);
      PD(p, "Starting");
      proto_start(p);
      proto_notify_state(p, (q->start ? q->start(p) : PS_UP));
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    }
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  }
  else
  {
    if (p->proto_state == PS_START || p->proto_state == PS_UP)
1036
    {
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      /* Going down */
      DBG("Kicking %s down\n", p->name);
      PD(p, "Shutting down");
      proto_notify_state(p, (q->shutdown ? q->shutdown(p) : PS_DOWN));
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    }
1042
  }
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}

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/**
 * DOC: Graceful restart recovery
 *
 * Graceful restart of a router is a process when the routing plane (e.g. BIRD)
 * restarts but both the forwarding plane (e.g kernel routing table) and routing
 * neighbors keep proper routes, and therefore uninterrupted packet forwarding
 * is maintained.
 *
 * BIRD implements graceful restart recovery by deferring export of routes to
 * protocols until routing tables are refilled with the expected content. After
 * start, protocols generate routes as usual, but routes are not propagated to
 * them, until protocols report that they generated all routes. After that,
 * graceful restart recovery is finished and the export (and the initial feed)
 * to protocols is enabled.
 *
 * When graceful restart recovery need is detected during initialization, then
 * enabled protocols are marked with @gr_recovery flag before start. Such
 * protocols then decide how to proceed with graceful restart, participation is
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 * voluntary. Protocols could lock the recovery for each channel by function
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 * channel_graceful_restart_lock() (state stored in @gr_lock flag), which means
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 * that they want to postpone the end of the recovery until they converge and
 * then unlock it. They also could set @gr_wait before advancing to %PS_UP,
 * which means that the core should defer route export to that channel until
 * the end of the recovery. This should be done by protocols that expect their
 * neigbors to keep the proper routes (kernel table, BGP sessions with BGP
 * graceful restart capability).
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 *
 * The graceful restart recovery is finished when either all graceful restart
 * locks are unlocked or when graceful restart wait timer fires.
 *
 */
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1078
static void graceful_restart_done(timer *t);
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/**
 * graceful_restart_recovery - request initial graceful restart recovery
 *
 * Called by the platform initialization code if the need for recovery
 * after graceful restart is detected during boot. Have to be called
 * before protos_commit().
 */
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void
graceful_restart_recovery(void)
{
  graceful_restart_state = GRS_INIT;
}

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/**
 * graceful_restart_init - initialize graceful restart
 *
 * When graceful restart recovery was requested, the function starts an active
 * phase of the recovery and initializes graceful restart wait timer. The
 * function have to be called after protos_commit().
 */
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void
graceful_restart_init(void)
{
  if (!graceful_restart_state)
    return;

  log(L_INFO "Graceful restart started");

  if (!graceful_restart_locks)
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  {
    graceful_restart_done(NULL);
    return;
  }
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  graceful_restart_state = GRS_ACTIVE;
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  gr_wait_timer = tm_new_init(proto_pool, graceful_restart_done, NULL, 0, 0);
  tm_start(gr_wait_timer, config->gr_wait S);
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}

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/**
 * graceful_restart_done - finalize graceful restart
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 * @t: unused
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 *
 * When there are no locks on graceful restart, the functions finalizes the
 * graceful restart recovery. Protocols postponing route export until the end of
 * the recovery are awakened and the export to them is enabled. All other
 * related state is cleared. The function is also called when the graceful
 * restart wait timer fires (but there are still some locks).
 */
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static void
1130
graceful_restart_done(timer *t UNUSED)
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{
  log(L_INFO "Graceful restart done");
  graceful_restart_state = GRS_DONE;

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  struct proto *p;
  WALK_LIST(p, proto_list)
  {
    if (!p->gr_recovery)
      continue;
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    struct channel *c;
    WALK_LIST(c, p->channels)
    {
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      /* Resume postponed export of routes */
1145
      if ((c->channel_state == CS_UP) && c->gr_wait && c->proto->rt_notify)
1146
	channel_start_export(c);
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      /* Cleanup */
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      c->gr_wait = 0;
      c->gr_lock = 0;
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    }

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    p->gr_recovery = 0;
  }

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  graceful_restart_locks = 0;
}

void
graceful_restart_show_status(void)
{
  if (graceful_restart_state != GRS_ACTIVE)
    return;

  cli_msg(-24, "Graceful restart recovery in progress");
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  cli_msg(-24, "  Waiting for %d channels to recover", graceful_restart_locks);
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  cli_msg(-24, "  Wait timer is %t/%u", tm_remains(gr_wait_timer), config->gr_wait);
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}

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/**
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 * channel_graceful_restart_lock - lock graceful restart by channel
 * @p: channel instance
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 *
 * This function allows a protocol to postpone the end of graceful restart
 * recovery until it converges. The lock is removed when the protocol calls
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 * channel_graceful_restart_unlock() or when the channel is closed.
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 *
 * The function have to be called during the initial phase of graceful restart
 * recovery and only for protocols that are part of graceful restart (i.e. their
 * @gr_recovery is set), which means it should be called from protocol start
 * hooks.
 */
1183
void
1184
channel_graceful_restart_lock(struct channel *c)
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{
  ASSERT(graceful_restart_state == GRS_INIT);
1187
  ASSERT(c->proto->gr_recovery);
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1189
  if (c->gr_lock)
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    return;

1192
  c->gr_lock = 1;
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  graceful_restart_locks++;
}

1196
/**
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 * channel_graceful_restart_unlock - unlock graceful restart by channel
 * @p: channel instance
1199
 *
1200
 * This function unlocks a lock from channel_graceful_restart_lock(). It is also
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 * automatically called when the lock holding protocol went down.
 */
1203
void
1204
channel_graceful_restart_unlock(struct channel *c)
1205
{
1206
  if (!c->gr_lock)
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    return;

1209
  c->gr_lock = 0;
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  graceful_restart_locks--;

  if ((graceful_restart_state == GRS_ACTIVE) && !graceful_restart_locks)
1213
    tm_start(gr_wait_timer, 0);
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}



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/**
 * protos_dump_all - dump status of all protocols
 *
 * This function dumps status of all existing protocol instances to the
 * debug output. It involves printing of general status information
 * such as protocol states, its position on the protocol lists
 * and also calling of a dump() hook of the protocol to print
 * the internals.
 */
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void
protos_dump_all(void)
{
  debug("Protocols:\n");

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  struct proto *p;
  WALK_LIST(p, proto_list)
  {
    debug("  protocol %s state %s\n", p->name, p_states[p->proto_state]);

    struct channel *c;
    WALK_LIST(c, p->channels)
1239
    {
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      debug("\tTABLE %s\n", c->table->name);
      if (c->in_filter)
	debug("\tInput filter: %s\n", filter_name(c->in_filter));
      if (c->out_filter)
	debug("\tOutput filter: %s\n", filter_name(c->out_filter));
1245
    }
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    if (p->proto->dump && (p->proto_state != PS_DOWN))
      p->proto->dump(p);
  }
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}

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/**
 * proto_build - make a single protocol available
 * @p: the protocol
 *
 * After the platform specific initialization code uses protos_build()
 * to add all the standard protocols, it should call proto_build() for
1258
 * all platform specific protocols to inform the core that they exist.
1259
 */
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void
proto_build(struct protocol *p)
{
  add_tail(&protocol_list, &p->n);
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  ASSERT(p->class);
  ASSERT(!class_to_protocol[p->class]);
  class_to_protocol[p->class] = p;
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}

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/* FIXME: convert this call to some protocol hook */
extern void bfd_init_all(void);

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/**
 * protos_build - build a protocol list
 *
 * This function is called during BIRD startup to insert
 * all standard protocols to the global protocol list. Insertion
 * of platform specific protocols (such as the kernel syncer)
 * is in the domain of competence of the platform dependent
 * startup code.
 */
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void
protos_build(void)
{
1284
  init_list(&proto_list);
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  init_list(&protocol_list);

1287
  proto_build(&proto_device);
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#ifdef CONFIG_RADV
  proto_build(&proto_radv);
#endif
1291
#ifdef CONFIG_RIP
1292
  proto_build(&proto_rip);
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#endif
#ifdef CONFIG_STATIC
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  proto_build(&proto_static);
Ondřej Filip's avatar
Ondřej Filip committed
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#endif
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#ifdef CONFIG_MRT
  proto_build(&proto_mrt);
#endif
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#ifdef CONFIG_OSPF
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  proto_build(&proto_ospf);
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#endif
#ifdef CONFIG_PIPE
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  proto_build(&proto_pipe);
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#endif
#ifdef CONFIG_BGP
1307
  proto_build(&proto_bgp);
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#endif
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#ifdef CONFIG_BFD
1310
  proto_build(&proto_bfd);
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  bfd_init_all();
#endif
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#ifdef CONFIG_BABEL
  proto_build(&proto_babel);
#endif
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#ifdef CONFIG_RPKI
  proto_build(&proto_rpki);
#endif
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1320
  proto_pool = rp_new(&root_pool, "Protocols");
1321
  proto_shutdown_timer = tm_new(proto_pool);
1322
  proto_shutdown_timer->hook = proto_shutdown_loop;
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}

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/* Temporary hack to propagate restart to BGP */
int proto_restart;
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1329
static void
1330
proto_shutdown_loop(timer *t UNUSED)
1331 1332 1333
{
  struct proto *p, *p_next;

1334
  WALK_LIST_DELSAFE(p, p_next, proto_list)
1335
    if (p->down_sched)
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    {
      proto_restart = (p->down_sched == PDS_RESTART);
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      p->disabled = 1;
      proto_rethink_goal(p);
      if (proto_restart)
      {
	p->disabled = 0;
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	proto_rethink_goal(p);
      }
1346
    }
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}

static inline void
proto_schedule_down(struct proto *p, byte restart, byte code)
{
  /* Does not work for other states (even PS_START) */
  ASSERT(p->proto_state == PS_UP);

  /* Scheduled restart may change to shutdown, but not otherwise */
  if (p->down_sched == PDS_DISABLE)
    return;

  p->down_sched = restart ? PDS_RESTART : PDS_DISABLE;
  p->down_code = code;
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  tm_start_max(proto_shutdown_timer, restart ? 250 MS : 0);
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}

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/**
 * proto_set_message - set administrative message to protocol
 * @p: protocol
 * @msg: message
 * @len: message length (-1 for NULL-terminated string)
 *
 * The function sets administrative message (string) related to protocol state
 * change. It is called by the nest code for manual enable/disable/restart
 * commands all routes to the protocol, and by protocol-specific code when the
 * protocol state change is initiated by the protocol. Using NULL message clears
 * the last message. The message string may be either NULL-terminated or with an
 * explicit length.
 */
void
proto_set_message(struct proto *p, char *msg, int len)
{
  mb_free(p->message);
  p->message = NULL;

  if (!msg || !len)
    return;

  if (len < 0)
    len = strlen(msg);

  if (!len)
    return;

  p->message = mb_alloc(proto_pool, len + 1);
  memcpy(p->message, msg, len);
  p->message[len] = 0;
}

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static const char *
1399
channel_limit_name(struct channel_limit *l)
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{
  const char *actions[] = {
    [PLA_WARN] = "warn",
    [PLA_BLOCK] = "block",
    [PLA_RESTART] = "restart",
    [PLA_DISABLE] = "disable",
  };

  return actions[l->action];
}

/**
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 * channel_notify_limit: notify about limit hit and take appropriate action
 * @c: channel
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 * @l: limit being hit
1415
 * @dir: limit direction (PLD_*)
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 * @rt_count: the number of routes
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 *
 * The function is called by the route processing core when limit @l
 * is breached. It activates the limit and tooks appropriate action
1420
 * according to @l->action.
1421
 */
1422
void
1423
channel_notify_limit(struct channel *c, struct channel_limit *l, int dir, u32 rt_count)
1424
{
1425 1426
  const char *dir_name[PLD_MAX] = { "receive", "import" , "export" };
  const byte dir_down[PLD_MAX] = { PDC_RX_LIMIT_HIT, PDC_IN_LIMIT_HIT, PDC_OUT_LIMIT_HIT };
1427
  struct proto *p = c->proto;
1428

1429 1430
  if (l->state == PLS_BLOCKED)
    return;
1431

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  /* For warning action, we want the log message every time we hit the limit */
  if (!l->state || ((l->action == PLA_WARN) && (rt_count == l->limit)))
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    log(L_WARN "Protocol %s hits route %s limit (%d), action: %s",
1435
	p->name, dir_name[dir], l->limit, channel_limit_name(l));
1436 1437

  switch (l->action)
1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453
  {
  case PLA_WARN:
    l->state = PLS_ACTIVE;
    break;

  case PLA_BLOCK:
    l->state = PLS_BLOCKED;
    break;

  case PLA_RESTART:
  case PLA_DISABLE:
    l->state = PLS_BLOCKED;
    if (p->proto_state == PS_UP)
      proto_schedule_down(p, l->action == PLA_RESTART, dir_down[dir]);
    break;
  }
1454 1455
}

1456 1457
static void
channel_verify_limits(struct channel *c)
1458
{
1459 1460
  struct channel_limit *l;
  u32 all_routes = c->stats.imp_routes + c->stats.filt_routes;
1461

1462 1463 1464
  l = &c->rx_limit;
  if (l->action && (all_routes > l->limit))
    channel_notify_limit(c, l, PLD_RX, all_routes);
1465

1466 1467 1468
  l = &c->in_limit;
  if (l->action && (c->stats.imp_routes > l->limit))
    channel_notify_limit(c, l, PLD_IN, c->stats.imp_routes);
1469

1470 1471 1472
  l = &c->out_limit;
  if (l->action && (c->stats.exp_routes > l->limit))
    channel_notify_limit(c, l, PLD_OUT, c->stats.exp_routes);
1473 1474
}

1475 1476
static inline void
channel_reset_limit(struct channel_limit *l)
1477
{
1478 1479
  if (l->action)
    l->state = PLS_INITIAL;
1480 1481
}

1482 1483
static inline void
proto_do_start(struct proto *p)
1484
{
1485 1486 1487
  p->active = 1;
  p->do_start = 1;
  ev_schedule(p->event);
1488 1489 1490
}

static void
1491
proto_do_up(struct proto *p)
1492
{
1493 1494 1495 1496 1497
  if (!p->main_source)
  {
    p->main_source = rt_get_source(p, 0);
    rt_lock_source(p->main_source);
  }
1498

1499
  proto_start_channels(p);
1500 1501
}

1502 1503
static inline void
proto_do_pause(struct proto *p)
1504
{
1505
  proto_pause_channels(p);
1506 1507 1508
}

static void
1509
proto_do_stop(struct proto *p)
1510
{
1511
  p->down_sched = 0;
1512
  p->gr_recovery = 0;
1513

1514 1515
  p->do_stop = 1;
  ev_schedule(p->event);
1516

1517 1518 1519 1520 1521
  if (p->main_source)
  {
    rt_unlock_source(p->main_source);
    p->main_source = NULL;
  }
1522

1523 1524
  proto_stop_channels(p);
}
1525

1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536
static void
proto_do_down(struct proto *p)
{
  p->down_code = 0;
  neigh_prune();
  rfree(p->pool);
  p->pool = NULL;

  /* Shutdown is finished in the protocol event */
  if (proto_is_done(p))
    ev_schedule(p->event);
1537 1538
}

1539

1540

1541 1542 1543 1544 1545 1546 1547 1548 1549 1550
/**
 * proto_notify_state - notify core about protocol state change
 * @p: protocol the state of which has changed
 * @ps: the new status
 *
 * Whenever a state of a protocol changes due to some event internal
 * to the protocol (i.e., not inside a start() or shutdown() hook),
 * it should immediately notify the core about the change by calling
 * proto_notify_state() which will write the new state to the &proto
 * structure and take all the actions necessary to adapt to the new
1551 1552 1553
 * state. State change to PS_DOWN immediately frees resources of protocol
 * and might execute start callback of protocol; therefore,
 * it should be used at tail positions of protocol callbacks.
1554
 */
1555
void
1556
proto_notify_state(struct proto *p, uint state)
1557
{
1558
  uint ps = p->proto_state;
1559

1560 1561
  DBG("%s reporting state transition %s -> %s\n", p->name, p_states[ps], p_states[state]);
  if (state == ps)
1562 1563
    return;

1564
  p->proto_state = state;
1565
  p->last_state_change = current_time();
1566

1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602
  switch (state)
  {
  case PS_START:
    ASSERT(ps == PS_DOWN || ps == PS_UP);

    if (ps == PS_DOWN)
      proto_do_start(p);
    else
      proto_do_pause(p);
    break;

  case PS_UP:
    ASSERT(ps == PS_DOWN || ps == PS_START);

    if (ps == PS_DOWN)
      proto_do_start(p);

    proto_do_up(p);
    break;

  case PS_STOP:
    ASSERT(ps == PS_START || ps == PS_UP);

    proto_do_stop(p);
    break;

  case PS_DOWN:
    if (