proto.c 45.7 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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#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->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++;

  c->feed_event = ev_new(c->proto->pool);
  c->feed_event->data = c;
  c->feed_event->hook = channel_feed_loop;

  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);
  // ASSERT(channel_reloadable(c));

  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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  /* 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)
  {
    *pc = proto_add_channel(p, cf);
  }
  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);

  p->event = ev_new(proto_pool);
  p->event->hook = proto_event;
  p->event->data = p;

  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);

786
  /*
787 788 789 790 791 792 793 794
   * 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;

795
  memcpy(dest, src, src->protocol->config_size);
796 797 798 799

  dest->n = old_node;
  dest->class = old_class;
  dest->name = old_name;
800
  init_list(&dest->channels);
801

802 803 804 805
  WALK_LIST(cc, src->channels)
    channel_copy_config(cc, dest);

  /* FIXME: allow for undefined copy_config */
806 807 808
  dest->protocol->copy_config(dest, src);
}

809 810 811 812 813 814 815 816
/**
 * 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.
 */
817
void
818
protos_preconfig(struct config *c)
819
{
820 821
  struct protocol *p;

822
  init_list(&c->protos);
823
  DBG("Protocol preconfig:");
824
  WALK_LIST(p, protocol_list)
825 826 827 828 829 830
  {
    DBG(" %s", p->name);
    p->name_counter = 0;
    if (p->preconfig)
      p->preconfig(p, c);
  }
831
  DBG("\n");
832 833
}

834 835 836 837 838 839 840 841 842
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) ||
843
      (nc->net_type != oc->net_type) ||
844
      (nc->disabled != p->disabled) ||
845
      (nc->vrf != oc->vrf))
846 847
    return 0;

848
  p->name = nc->name;
849 850
  p->debug = nc->debug;
  p->mrtdump = nc->mrtdump;
851
  reconfigure_type = type;
852 853

  /* Execute protocol specific reconfigure hook */
854
  if (!p->proto->reconfigure || !p->proto->reconfigure(p, nc))
855 856 857 858 859 860 861 862 863
    return 0;

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

  return 1;
}

864 865 866 867 868 869
/**
 * 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)
870
 * @type: type of reconfiguration (RECONFIG_SOFT or RECONFIG_HARD)
871 872 873 874 875 876 877 878 879 880 881 882
 *
 * 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.
 *
883 884 885 886 887 888 889 890
 * 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.
891
 */
892
void
893
protos_commit(struct config *new, struct config *old, int force_reconfig, int type)
894
{
895
  struct proto_config *oc, *nc;
896
  struct symbol *sym;
897 898 899
  struct proto *p;
  node *n;

900

901 902
  DBG("protos_commit:\n");
  if (old)
903 904
  {
    WALK_LIST(oc, old->protos)
905
    {
906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944
      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);
945
    }
946 947 948
  }

  struct proto *first_dev_proto = NULL;
949

950
  n = NODE &(proto_list.head);
951 952
  WALK_LIST(nc, new->protos)
    if (!nc->proto)
953 954 955 956 957 958 959 960 961 962 963 964 965
    {
      /* 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;
966 967

  DBG("Protocol start\n");
968 969

  /* Start device protocol first */
970 971
  if (first_dev_proto)
    proto_rethink_goal(first_dev_proto);
972

973 974 975
  /* 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)
976 977 978 979 980
  {
    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");
  }
981

982 983
  /* Start all new protocols */
  WALK_LIST_DELSAFE(p, n, proto_list)
984
    proto_rethink_goal(p);
985 986
}

987
static void
988
proto_rethink_goal(struct proto *p)
989
{
990
  struct protocol *q;
991
  byte goal;
992

993 994 995 996 997 998 999 1000 1001 1002
  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);
1003
    mb_free(p->message);
1004 1005 1006 1007 1008
    mb_free(p);
    if (!nc)
      return;
    p = proto_init(nc, n);
  }
1009 1010

  /* Determine what state we want to reach */
1011
  if (p->disabled || p->reconfiguring)
1012
    goal = PS_DOWN;
1013
  else
1014
    goal = PS_UP;
1015 1016

  q = p->proto;
1017 1018 1019
  if (goal == PS_UP)
  {
    if (!p->active)
1020
    {
1021 1022 1023 1024 1025
      /* 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));
1026
    }
1027 1028 1029 1030
  }
  else
  {
    if (p->proto_state == PS_START || p->proto_state == PS_UP)
1031
    {
1032 1033 1034 1035
      /* Going down */
      DBG("Kicking %s down\n", p->name);
      PD(p, "Shutting down");
      proto_notify_state(p, (q->shutdown ? q->shutdown(p) : PS_DOWN));
1036
    }
1037
  }
1038 1039
}

1040

1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058
/**
 * 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
1059
 * voluntary. Protocols could lock the recovery for each channel by function
1060
 * channel_graceful_restart_lock() (state stored in @gr_lock flag), which means
1061 1062 1063 1064 1065 1066
 * 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).
1067 1068 1069 1070 1071
 *
 * The graceful restart recovery is finished when either all graceful restart
 * locks are unlocked or when graceful restart wait timer fires.
 *
 */
1072

1073
static void graceful_restart_done(timer *t);
1074

1075 1076 1077 1078 1079 1080 1081
/**
 * 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().
 */
1082 1083 1084 1085 1086 1087
void
graceful_restart_recovery(void)
{
  graceful_restart_state = GRS_INIT;
}

1088 1089 1090 1091 1092 1093 1094
/**
 * 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().
 */
1095 1096 1097 1098 1099 1100 1101 1102 1103
void
graceful_restart_init(void)
{
  if (!graceful_restart_state)
    return;

  log(L_INFO "Graceful restart started");

  if (!graceful_restart_locks)
1104 1105 1106 1107
  {
    graceful_restart_done(NULL);
    return;
  }
1108 1109

  graceful_restart_state = GRS_ACTIVE;
1110 1111
  gr_wait_timer = tm_new_init(proto_pool, graceful_restart_done, NULL, 0, 0);
  tm_start(gr_wait_timer, config->gr_wait S);
1112 1113
}

1114 1115
/**
 * graceful_restart_done - finalize graceful restart
1116
 * @t: unused
1117 1118 1119 1120 1121 1122 1123
 *
 * 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).
 */
1124
static void
1125
graceful_restart_done(timer *t UNUSED)
1126 1127 1128 1129
{
  log(L_INFO "Graceful restart done");
  graceful_restart_state = GRS_DONE;

1130 1131 1132 1133 1134
  struct proto *p;
  WALK_LIST(p, proto_list)
  {
    if (!p->gr_recovery)
      continue;
1135

1136 1137 1138
    struct channel *c;
    WALK_LIST(c, p->channels)
    {
1139
      /* Resume postponed export of routes */
1140
      if ((c->channel_state == CS_UP) && c->gr_wait && c->proto->rt_notify)
1141
	channel_start_export(c);
1142 1143

      /* Cleanup */
1144 1145
      c->gr_wait = 0;
      c->gr_lock = 0;
1146 1147
    }

1148 1149 1150
    p->gr_recovery = 0;
  }

1151 1152 1153 1154 1155 1156 1157 1158 1159 1160
  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");
1161
  cli_msg(-24, "  Waiting for %d channels to recover", graceful_restart_locks);
1162
  cli_msg(-24, "  Wait timer is %t/%u", tm_remains(gr_wait_timer), config->gr_wait);
1163 1164
}

1165
/**
1166 1167
 * channel_graceful_restart_lock - lock graceful restart by channel
 * @p: channel instance
1168 1169 1170
 *
 * This function allows a protocol to postpone the end of graceful restart
 * recovery until it converges. The lock is removed when the protocol calls
1171
 * channel_graceful_restart_unlock() or when the channel is closed.
1172 1173 1174 1175 1176 1177
 *
 * 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.
 */
1178
void
1179
channel_graceful_restart_lock(struct channel *c)
1180 1181
{
  ASSERT(graceful_restart_state == GRS_INIT);
1182
  ASSERT(c->proto->gr_recovery);
1183

1184
  if (c->gr_lock)
1185 1186
    return;

1187
  c->gr_lock = 1;
1188 1189 1190
  graceful_restart_locks++;
}

1191
/**
1192 1193
 * channel_graceful_restart_unlock - unlock graceful restart by channel
 * @p: channel instance
1194
 *
1195
 * This function unlocks a lock from channel_graceful_restart_lock(). It is also
1196 1197
 * automatically called when the lock holding protocol went down.
 */
1198
void
1199
channel_graceful_restart_unlock(struct channel *c)
1200
{
1201
  if (!c->gr_lock)
1202 1203
    return;

1204
  c->gr_lock = 0;
1205 1206 1207
  graceful_restart_locks--;

  if ((graceful_restart_state == GRS_ACTIVE) && !graceful_restart_locks)
1208
    tm_start(gr_wait_timer, 0);
1209 1210 1211 1212
}



1213 1214 1215 1216 1217 1218 1219 1220 1221
/**
 * 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.
 */
1222 1223 1224 1225 1226
void
protos_dump_all(void)
{
  debug("Protocols:\n");

1227 1228 1229 1230 1231 1232 1233
  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)
1234
    {
1235 1236 1237 1238 1239
      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));
1240
    }
1241 1242 1243 1244

    if (p->proto->dump && (p->proto_state != PS_DOWN))
      p->proto->dump(p);
  }
1245 1246
}

1247 1248 1249 1250 1251 1252
/**
 * 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
1253
 * all platform specific protocols to inform the core that they exist.
1254
 */
1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265
void
proto_build(struct protocol *p)
{
  add_tail(&protocol_list, &p->n);
  if (p->attr_class)
    {
      ASSERT(!attr_class_to_protocol[p->attr_class]);
      attr_class_to_protocol[p->attr_class] = p;
    }
}

1266 1267 1268
/* FIXME: convert this call to some protocol hook */
extern void bfd_init_all(void);

1269 1270 1271 1272 1273 1274 1275 1276 1277
/**
 * 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.
 */
1278 1279 1280
void
protos_build(void)
{
1281
  init_list(&proto_list);
1282 1283
  init_list(&protocol_list);

1284
  proto_build(&proto_device);
1285 1286 1287
#ifdef CONFIG_RADV
  proto_build(&proto_radv);
#endif
1288
#ifdef CONFIG_RIP
1289
  proto_build(&proto_rip);
1290 1291
#endif
#ifdef CONFIG_STATIC
1292
  proto_build(&proto_static);
1293 1294
#endif
#ifdef CONFIG_OSPF
1295
  proto_build(&proto_ospf);
1296 1297
#endif
#ifdef CONFIG_PIPE
1298
  proto_build(&proto_pipe);
1299 1300
#endif
#ifdef CONFIG_BGP
1301
  proto_build(&proto_bgp);
1302
#endif
1303
#ifdef CONFIG_BFD
1304
  proto_build(&proto_bfd);
1305 1306
  bfd_init_all();
#endif
1307 1308 1309
#ifdef CONFIG_BABEL
  proto_build(&proto_babel);
#endif
1310 1311 1312
#ifdef CONFIG_RPKI
  proto_build(&proto_rpki);
#endif
1313

1314
  proto_pool = rp_new(&root_pool, "Protocols");
1315
  proto_shutdown_timer = tm_new(proto_pool);
1316
  proto_shutdown_timer->hook = proto_shutdown_loop;
1317 1318
}

1319

1320 1321
/* Temporary hack to propagate restart to BGP */
int proto_restart;
1322

1323
static void
1324
proto_shutdown_loop(timer *t UNUSED)
1325 1326 1327
{
  struct proto *p, *p_next;

1328
  WALK_LIST_DELSAFE(p, p_next, proto_list)
1329
    if (p->down_sched)
1330 1331
    {
      proto_restart = (p->down_sched == PDS_RESTART);
1332

1333 1334 1335 1336 1337
      p->disabled = 1;
      proto_rethink_goal(p);
      if (proto_restart)
      {
	p->disabled = 0;
1338 1339
	proto_rethink_goal(p);
      }
1340
    }
1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354
}

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;
1355
  tm_start_max(proto_shutdown_timer, restart ? 250 MS : 0);
1356 1357
}

1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390
/**
 * 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;
}

1391 1392

static const char *
1393
channel_limit_name(struct channel_limit *l)
1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405
{
  const char *actions[] = {
    [PLA_WARN] = "warn",
    [PLA_BLOCK] = "block",
    [PLA_RESTART] = "restart",
    [PLA_DISABLE] = "disable",
  };

  return actions[l->action];
}

/**
1406 1407
 * channel_notify_limit: notify about limit hit and take appropriate action
 * @c: channel
1408
 * @l: limit being hit
1409
 * @dir: limit direction (PLD_*)
1410
 * @rt_count: the number of routes
1411 1412 1413
 *
 * The function is called by the route processing core when limit @l
 * is breached. It activates the limit and tooks appropriate action
1414
 * according to @l->action.
1415
 */
1416
void
1417
channel_notify_limit(struct channel *c, struct channel_limit *l, int dir, u32 rt_count)
1418
{
1419 1420
  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 };
1421
  struct proto *p = c->proto;
1422

1423 1424
  if (l->state == PLS_BLOCKED)
    return;
1425

1426 1427
  /* 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)))
1428
    log(L_WARN "Protocol %s hits route %s limit (%d), action: %s",
1429
	p->name, dir_name[dir], l->limit, channel_limit_name(l));
1430 1431

  switch (l->action)
1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447
  {
  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;
  }
1448 1449
}

1450 1451
static void
channel_verify_limits(struct channel *c)
1452
{
1453 1454
  struct channel_limit *l;
  u32 all_routes = c->stats.imp_routes + c->stats.filt_routes;
1455

1456 1457 1458
  l = &c->rx_limit;
  if (l->action && (all_routes > l->limit))
    channel_notify_limit(c, l, PLD_RX, all_routes);
1459

1460 1461 1462
  l = &c->in_limit;
  if (l->action && (c->stats.imp_routes > l->limit))
    channel_notify_limit(c, l, PLD_IN, c->stats.imp_routes);
1463

1464 1465 1466
  l = &c->out_limit;
  if (l->action && (c->stats.exp_routes > l->limit))
    channel_notify_limit(c, l, PLD_OUT, c->stats.exp_routes);
1467 1468
}

1469 1470
static inline void
channel_reset_limit(struct channel_limit *l)
1471
{
1472 1473
  if (l->action)
    l->state = PLS_INITIAL;
1474 1475
}

1476 1477
static inline void
proto_do_start(struct proto *p)
1478
{
1479 1480 1481
  p->active = 1;
  p->do_start = 1;
  ev_schedule(p->event);
1482 1483 1484
}

static void
1485
proto_do_up(struct proto *p)
1486
{
1487 1488 1489 1490 1491
  if (!p->main_source)
  {
    p->main_source = rt_get_source(p, 0);
    rt_lock_source(p->main_source);
  }
1492

1493
  proto_start_channels(p);
1494 1495
}

1496 1497
static inline void
proto_do_pause(struct proto *p)
1498
{
1499
  proto_pause_channels(p);
1500 1501 1502
}

static void
1503
proto_do_stop(struct proto *p)
1504
{
1505
  p->down_sched = 0;
1506
  p->gr_recovery = 0;
1507

1508 1509
  p->do_stop = 1;
  ev_schedule(p->event);
1510

1511 1512 1513 1514 1515
  if (p->main_source)
  {
    rt_unlock_source(p->main_source);
    p->main_source = NULL;
  }
1516

1517 1518
  proto_stop_channels(p);
}
1519

1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530
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);
1531 1532
}

1533

1534

1535 1536 1537 1538 1539 1540 1541 1542 1543 1544
/**
 * 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
1545 1546 1547
 * 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.
1548
 */
1549
void
1550
proto_notify_state(struct proto *p, uint state)
1551
{
1552
  uint ps = p->proto_state;
1553

1554 1555
  DBG("%s reporting state transition %s -> %s\n", p->name, p_states[ps], p_states[state]);
  if (state == ps)
1556 1557
    return;

1558
  p->proto_state = state;
1559
  p->last_state_change = current_time();
1560

1561 1562 1563 1564 1565 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
  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 (ps != PS_STOP)
      proto_do_stop(p);

    proto_do_down(p);
    break;

  default:
    bug("%s: Invalid state %d", p->name, ps);
  }
1597 1598

  proto_log_state_change(p);
1599
}
1600

1601 1602 1603 1604 1605 1606 1607
/*
 *  CLI Commands
 */

static char *
proto_state_name(struct proto *p)
{
1608 1609 1610 1611 1612 1613 1614 1615
  switch (p->proto_state)
  {
  case PS_DOWN:		return p->active ? "flush" : "down";
  case PS_START:	return "start";
  case PS_UP:		return "up";
  case PS_STOP:		return "stop";
  default:		return "???";
  }
1616 1617
}