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bird/nest/proto.c
Ondrej Zajicek (work) f4a60a9bc4 Channels - explicit links between protocols and tables 
The patch adds support for channels, structures connecting protocols and
tables and handling most interactions between them. The documentation is
missing yet.
2016-02-01 10:28:50 +01:00

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/*
* BIRD -- Protocols
*
* (c) 1998--2000 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#undef LOCAL_DEBUG
#include "nest/bird.h"
#include "nest/protocol.h"
#include "lib/resource.h"
#include "lib/lists.h"
#include "lib/event.h"
#include "lib/string.h"
#include "conf/conf.h"
#include "nest/route.h"
#include "nest/iface.h"
#include "nest/cli.h"
#include "filter/filter.h"
pool *proto_pool;
list proto_list;
static list protocol_list;
#define PD(pr, msg, args...) do { if (pr->debug & D_STATES) { log(L_TRACE "%s: " msg, pr->name , ## args); } } while(0)
static timer *proto_shutdown_timer;
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;
static char *p_states[] = { "DOWN", "START", "UP", "STOP" };
extern struct protocol proto_unix_iface;
static void proto_shutdown_loop(struct timer *);
static void proto_rethink_goal(struct proto *p);
static char *proto_state_name(struct proto *p);
static void channel_verify_limits(struct channel *c);
static void channel_reset_limit(struct channel_limit *l);
static inline int proto_is_done(struct proto *p)
{ return (p->proto_state == PS_DOWN) && (p->active_channels == 0); }
static inline int channel_is_active(struct channel *c)
{ return (c->channel_state == CS_START) || (c->channel_state == CS_UP); }
static void
proto_log_state_change(struct proto *p)
{
if (p->debug & D_STATES)
{
char *name = proto_state_name(p);
if (name != p->last_state_name_announced)
{
p->last_state_name_announced = name;
PD(p, "State changed to %s", proto_state_name(p));
}
}
else
p->last_state_name_announced = NULL;
}
struct channel_config *
proto_cf_find_channel(struct proto_config *pc, uint net_type)
{
struct channel_config *cc;
WALK_LIST(cc, pc->channels)
if (cc->net_type == net_type)
return cc;
return NULL;
}
/**
* 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)
{
struct channel *c;
WALK_LIST(c, p->channels)
if (c->table == t)
return c;
return NULL;
}
/**
* proto_add_channel - connect protocol to a routing table
* @p: protocol instance
* @cf: channel configuration
*
* 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.
*
* 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.
*/
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;
c->last_state_change = now;
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)
{
struct channel *c;
WALK_LIST(c, p->channels)
if (!c->disabled && channel_is_active(c))
channel_set_state(c, CS_START);
}
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);
}
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);
c->export_state = ES_FEEDING;
c->refeeding = !initial;
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;
}
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)
{
rem2_node(&c->table_node);
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));
/* 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;
DBG("%s reporting state transition %s/%s -> */%s\n", p->name, c_states[cs], p_states[ops], p_states[ps]);
if (state == cs)
return;
c->channel_state = state;
c->last_state_change = now;
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);
if (!c->gr_wait)
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);
}
/**
* channel_request_feeding - request feeding routes to the channel
* @c: given channel
*
* 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.
*/
void
channel_request_feeding(struct channel *c)
{
ASSERT(c->channel_state == CS_UP);
/* Do nothing if we are still waiting for feeding */
if (c->export_state == ES_DOWN)
return;
/* 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;
}
static void
channel_request_reload(struct channel *c)
{
ASSERT(c->channel_state == CS_UP);
// ASSERT(channel_reloadable(c));
c->proto->reload_routes(c);
/*
* 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);
}
const struct channel_class channel_basic = {
.channel_size = sizeof(struct channel),
.config_size = sizeof(struct channel_config)
};
void *
channel_config_new(const struct channel_class *cc, uint net_type, struct proto_config *proto)
{
struct channel_config *cf = NULL;
struct rtable_config *tab = NULL;
const char *name = 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];
name = net_label[net_type];
}
if (!cc)
cc = &channel_basic;
cf = cfg_allocz(cc->config_size);
cf->name = name;
cf->channel = cc;
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;
}
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 */
if ((c->table != cf->table->table) || (c->ra_mode != cf->ra_mode))
return 0;
int import_changed = !filter_same(c->in_filter, cf->in_filter);
int export_changed = !filter_same(c->out_filter, cf->out_filter);
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);
CALL(c->channel->reconfigure, c, cf);
/* 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)
{
struct channel *c = *pc;
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;
}
static void
proto_event(void *ptr)
{
struct proto *p = ptr;
if (p->do_start)
{
if_feed_baby(p);
p->do_start = 0;
}
if (p->do_stop)
{
if (p->proto == &proto_unix_iface)
if_flush_ifaces(p);
p->do_stop = 0;
}
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;
p->last_state_change = now;
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;
}
/**
* proto_config_new - create a new protocol configuration
* @pr: protocol the configuration will belong to
* @class: SYM_PROTO or SYM_TEMPLATE
*
* 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.
*
* 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()).
*/
void *
proto_config_new(struct protocol *pr, int class)
{
struct proto_config *cf = cfg_allocz(pr->config_size);
if (class == SYM_PROTO)
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;
}
/**
* 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)
{
struct channel_config *cc;
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);
/*
* 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;
memcpy(dest, src, src->protocol->config_size);
dest->n = old_node;
dest->class = old_class;
dest->name = old_name;
init_list(&dest->channels);
WALK_LIST(cc, src->channels)
channel_copy_config(cc, dest);
/* FIXME: allow for undefined copy_config */
dest->protocol->copy_config(dest, src);
}
/**
* 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.
*/
void
protos_preconfig(struct config *c)
{
struct protocol *p;
init_list(&c->protos);
DBG("Protocol preconfig:");
WALK_LIST(p, protocol_list)
{
DBG(" %s", p->name);
p->name_counter = 0;
if (p->preconfig)
p->preconfig(p, c);
}
DBG("\n");
}
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) ||
(nc->net_type != oc->net_type) ||
(nc->disabled != p->disabled))
return 0;
p->name = nc->name;
p->debug = nc->debug;
p->mrtdump = nc->mrtdump;
reconfigure_type = type;
/* Execute protocol specific reconfigure hook */
if (!p->proto->reconfigure || !p->proto->reconfigure(p, nc))
return 0;
DBG("\t%s: same\n", oc->name);
PD(p, "Reconfigured");
p->cf = nc;
return 1;
}
/**
* 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)
* @type: type of reconfiguration (RECONFIG_SOFT or RECONFIG_HARD)
*
* 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.
*
* 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.
*/
void
protos_commit(struct config *new, struct config *old, int force_reconfig, int type)
{
struct proto_config *oc, *nc;
struct symbol *sym;
struct proto *p;
node *n;
DBG("protos_commit:\n");
if (old)
{
WALK_LIST(oc, old->protos)
{
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);
}
}
struct proto *first_dev_proto = NULL;
n = NODE &(proto_list.head);
WALK_LIST(nc, new->protos)
if (!nc->proto)
{
/* 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;
DBG("Protocol start\n");
/* Start device protocol first */
if (first_dev_proto)
proto_rethink_goal(first_dev_proto);
/* 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)
{
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");
}
/* Start all new protocols */
WALK_LIST_DELSAFE(p, n, proto_list)
proto_rethink_goal(p);
}
static void
proto_rethink_goal(struct proto *p)
{
struct protocol *q;
byte goal;
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);
mb_free(p);
if (!nc)
return;
p = proto_init(nc, n);
}
/* Determine what state we want to reach */
if (p->disabled || p->reconfiguring)
goal = PS_DOWN;
else
goal = PS_UP;
q = p->proto;
if (goal == PS_UP)
{
if (!p->active)
{
/* 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));
}
}
else
{
if (p->proto_state == PS_START || p->proto_state == PS_UP)
{
/* Going down */
DBG("Kicking %s down\n", p->name);
PD(p, "Shutting down");
proto_notify_state(p, (q->shutdown ? q->shutdown(p) : PS_DOWN));
}
}
}
/**
* 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
* voluntary. Protocols could lock the recovery for each channel by function
* channel_graceful_restart_lock() (starte stored in @gr_lock flag), which means
* 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).
*
* The graceful restart recovery is finished when either all graceful restart
* locks are unlocked or when graceful restart wait timer fires.
*
*/
static void graceful_restart_done(struct timer *t);
/**
* 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().
*/
void
graceful_restart_recovery(void)
{
graceful_restart_state = GRS_INIT;
}
/**
* 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().
*/
void
graceful_restart_init(void)
{
if (!graceful_restart_state)
return;
log(L_INFO "Graceful restart started");
if (!graceful_restart_locks)
{
graceful_restart_done(NULL);
return;
}
graceful_restart_state = GRS_ACTIVE;
gr_wait_timer = tm_new(proto_pool);
gr_wait_timer->hook = graceful_restart_done;
tm_start(gr_wait_timer, config->gr_wait);
}
/**
* graceful_restart_done - finalize graceful restart
*
* 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).
*/
static void
graceful_restart_done(struct timer *t UNUSED)
{
log(L_INFO "Graceful restart done");
graceful_restart_state = GRS_DONE;
struct proto *p;
WALK_LIST(p, proto_list)
{
if (!p->gr_recovery)
continue;
struct channel *c;
WALK_LIST(c, p->channels)
{
/* Resume postponed export of routes */
if ((c->channel_state == CS_UP) && c->gr_wait)
channel_start_export(c);
/* Cleanup */
c->gr_wait = 0;
c->gr_lock = 0;
}
p->gr_recovery = 0;
}
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");
cli_msg(-24, " Waiting for %d channels to recover", graceful_restart_locks);
cli_msg(-24, " Wait timer is %d/%d", tm_remains(gr_wait_timer), config->gr_wait);
}
/**
* channel_graceful_restart_lock - lock graceful restart by channel
* @p: channel instance
*
* This function allows a protocol to postpone the end of graceful restart
* recovery until it converges. The lock is removed when the protocol calls
* channel_graceful_restart_unlock() or when the channel is closed.
*
* 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.
*/
void
channel_graceful_restart_lock(struct channel *c)
{
ASSERT(graceful_restart_state == GRS_INIT);
ASSERT(c->proto->gr_recovery);
if (c->gr_lock)
return;
c->gr_lock = 1;
graceful_restart_locks++;
}
/**
* channel_graceful_restart_unlock - unlock graceful restart by channel
* @p: channel instance
*
* This function unlocks a lock from channel_graceful_restart_lock(). It is also
* automatically called when the lock holding protocol went down.
*/
void
channel_graceful_restart_unlock(struct channel *c)
{
if (!c->gr_lock)
return;
c->gr_lock = 0;
graceful_restart_locks--;
if ((graceful_restart_state == GRS_ACTIVE) && !graceful_restart_locks)
tm_start(gr_wait_timer, 0);
}
/**
* 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.
*/
void
protos_dump_all(void)
{
debug("Protocols:\n");
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)
{
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));
}
if (p->proto->dump && (p->proto_state != PS_DOWN))
p->proto->dump(p);
}
}
/**
* 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
* all platform specific protocols to inform the core that they exist.
*/
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;
}
}
/* FIXME: convert this call to some protocol hook */
extern void bfd_init_all(void);
/**
* 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.
*/
void
protos_build(void)
{
init_list(&proto_list);
init_list(&protocol_list);
proto_build(&proto_device);
#ifdef CONFIG_RADV
proto_build(&proto_radv);
#endif
#ifdef CONFIG_RIP
proto_build(&proto_rip);
#endif
#ifdef CONFIG_STATIC
proto_build(&proto_static);
#endif
#ifdef CONFIG_OSPF
proto_build(&proto_ospf);
#endif
#ifdef CONFIG_PIPE
proto_build(&proto_pipe);
#endif
#ifdef CONFIG_BGP
proto_build(&proto_bgp);
#endif
#ifdef CONFIG_BFD
proto_build(&proto_bfd);
bfd_init_all();
#endif
proto_pool = rp_new(&root_pool, "Protocols");
proto_shutdown_timer = tm_new(proto_pool);
proto_shutdown_timer->hook = proto_shutdown_loop;
}
/* Temporary hack to propagate restart to BGP */
int proto_restart;
static void
proto_shutdown_loop(struct timer *t UNUSED)
{
struct proto *p, *p_next;
WALK_LIST_DELSAFE(p, p_next, proto_list)
if (p->down_sched)
{
proto_restart = (p->down_sched == PDS_RESTART);
p->disabled = 1;
proto_rethink_goal(p);
if (proto_restart)
{
p->disabled = 0;
proto_rethink_goal(p);
}
}
}
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;
tm_start_max(proto_shutdown_timer, restart ? 2 : 0);
}
static const char *
channel_limit_name(struct channel_limit *l)
{
const char *actions[] = {
[PLA_WARN] = "warn",
[PLA_BLOCK] = "block",
[PLA_RESTART] = "restart",
[PLA_DISABLE] = "disable",
};
return actions[l->action];
}
/**
* channel_notify_limit: notify about limit hit and take appropriate action
* @c: channel
* @l: limit being hit
* @dir: limit direction (PLD_*)
* @rt_count: the number of routes
*
* The function is called by the route processing core when limit @l
* is breached. It activates the limit and tooks appropriate action
* according to @l->action.
*/
void
channel_notify_limit(struct channel *c, struct channel_limit *l, int dir, u32 rt_count)
{
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 };
struct proto *p = c->proto;
if (l->state == PLS_BLOCKED)
return;
/* 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)))
log(L_WARN "Protocol %s hits route %s limit (%d), action: %s",
p->name, dir_name[dir], l->limit, channel_limit_name(l));
switch (l->action)
{
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;
}
}
static void
channel_verify_limits(struct channel *c)
{
struct channel_limit *l;
u32 all_routes = c->stats.imp_routes + c->stats.filt_routes;
l = &c->rx_limit;
if (l->action && (all_routes > l->limit))
channel_notify_limit(c, l, PLD_RX, all_routes);
l = &c->in_limit;
if (l->action && (c->stats.imp_routes > l->limit))
channel_notify_limit(c, l, PLD_IN, c->stats.imp_routes);
l = &c->out_limit;
if (l->action && (c->stats.exp_routes > l->limit))
channel_notify_limit(c, l, PLD_OUT, c->stats.exp_routes);
}
static inline void
channel_reset_limit(struct channel_limit *l)
{
if (l->action)
l->state = PLS_INITIAL;
}
static inline void
proto_do_start(struct proto *p)
{
p->active = 1;
p->do_start = 1;
ev_schedule(p->event);
}
static void
proto_do_up(struct proto *p)
{
if (!p->main_source)
{
p->main_source = rt_get_source(p, 0);
rt_lock_source(p->main_source);
}
proto_start_channels(p);
}
static inline void
proto_do_pause(struct proto *p)
{
proto_pause_channels(p);
}
static void
proto_do_stop(struct proto *p)
{
p->down_sched = 0;
p->gr_recovery = 0;
p->do_stop = 1;
ev_schedule(p->event);
if (p->main_source)
{
rt_unlock_source(p->main_source);
p->main_source = NULL;
}
proto_stop_channels(p);
}
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);
}
/**
* 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
* 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.
*/
void
proto_notify_state(struct proto *p, uint state)
{
uint ps = p->proto_state;
DBG("%s reporting state transition %s -> %s\n", p->name, p_states[ps], p_states[state]);
if (state == ps)
return;
p->proto_state = state;
p->last_state_change = now;
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);
}
proto_log_state_change(p);
}
/*
* CLI Commands
*/
static char *
proto_state_name(struct proto *p)
{
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 "???";
}
}
static void
channel_show_stats(struct channel *c)
{
struct proto_stats *s = &c->stats;
if (c->in_keep_filtered)
cli_msg(-1006, " Routes: %u imported, %u filtered, %u exported",
s->imp_routes, s->filt_routes, s->exp_routes);
else
cli_msg(-1006, " Routes: %u imported, %u exported",
s->imp_routes, s->exp_routes);
cli_msg(-1006, " Route change stats: received rejected filtered ignored accepted");
cli_msg(-1006, " Import updates: %10u %10u %10u %10u %10u",
s->imp_updates_received, s->imp_updates_invalid,
s->imp_updates_filtered, s->imp_updates_ignored,
s->imp_updates_accepted);
cli_msg(-1006, " Import withdraws: %10u %10u --- %10u %10u",
s->imp_withdraws_received, s->imp_withdraws_invalid,
s->imp_withdraws_ignored, s->imp_withdraws_accepted);
cli_msg(-1006, " Export updates: %10u %10u %10u --- %10u",
s->exp_updates_received, s->exp_updates_rejected,
s->exp_updates_filtered, s->exp_updates_accepted);
cli_msg(-1006, " Export withdraws: %10u --- --- --- %10u",
s->exp_withdraws_received, s->exp_withdraws_accepted);
}
void
channel_show_limit(struct channel_limit *l, const char *dsc)
{
if (!l->action)
return;
cli_msg(-1006, " %-16s%d%s", dsc, l->limit, l->state ? " [HIT]" : "");
cli_msg(-1006, " Action: %s", channel_limit_name(l));
}
void
channel_show_info(struct channel *c)
{
cli_msg(-1006, " Channel %s", c->name);
cli_msg(-1006, " Table: %s", c->table->name);
cli_msg(-1006, " Preference: %d", c->preference);
cli_msg(-1006, " Input filter: %s", filter_name(c->in_filter));
cli_msg(-1006, " Output filter: %s", filter_name(c->out_filter));
if (graceful_restart_state == GRS_ACTIVE)
cli_msg(-1006, " GR recovery: %s%s",
c->gr_lock ? " pending" : "",
c->gr_wait ? " waiting" : "");
channel_show_limit(&c->rx_limit, "Receive limit:");
channel_show_limit(&c->in_limit, "Import limit:");
channel_show_limit(&c->out_limit, "Export limit:");
if (c->channel_state != CS_DOWN)
channel_show_stats(c);
}
void
proto_cmd_show(struct proto *p, uint verbose, int cnt)
{
byte buf[256], tbuf[TM_DATETIME_BUFFER_SIZE];
/* First protocol - show header */
if (!cnt)
cli_msg(-2002, "name proto table state since info");
buf[0] = 0;
if (p->proto->get_status)
p->proto->get_status(p, buf);
tm_format_datetime(tbuf, &config->tf_proto, p->last_state_change);
cli_msg(-1002, "%-8s %-8s %-8s %-5s %-10s %s",
p->name,
p->proto->name,
p->main_channel ? p->main_channel->table->name : "---",
proto_state_name(p),
tbuf,
buf);
if (verbose)
{
if (p->cf->dsc)
cli_msg(-1006, " Description: %s", p->cf->dsc);
if (p->cf->router_id)
cli_msg(-1006, " Router ID: %R", p->cf->router_id);
if (p->proto->show_proto_info)
p->proto->show_proto_info(p);
else
{
struct channel *c;
WALK_LIST(c, p->channels)
channel_show_info(c);
}
cli_msg(-1006, "");
}
}
void
proto_cmd_disable(struct proto *p, uint arg UNUSED, int cnt UNUSED)
{
if (p->disabled)
{
cli_msg(-8, "%s: already disabled", p->name);
return;
}
log(L_INFO "Disabling protocol %s", p->name);
p->disabled = 1;
p->down_code = PDC_CMD_DISABLE;
proto_rethink_goal(p);
cli_msg(-9, "%s: disabled", p->name);
}
void
proto_cmd_enable(struct proto *p, uint arg UNUSED, int cnt UNUSED)
{
if (!p->disabled)
{
cli_msg(-10, "%s: already enabled", p->name);
return;
}
log(L_INFO "Enabling protocol %s", p->name);
p->disabled = 0;
proto_rethink_goal(p);
cli_msg(-11, "%s: enabled", p->name);
}
void
proto_cmd_restart(struct proto *p, uint arg UNUSED, int cnt UNUSED)
{
if (p->disabled)
{
cli_msg(-8, "%s: already disabled", p->name);
return;
}
log(L_INFO "Restarting protocol %s", p->name);
p->disabled = 1;
p->down_code = PDC_CMD_RESTART;
proto_rethink_goal(p);
p->disabled = 0;
proto_rethink_goal(p);
cli_msg(-12, "%s: restarted", p->name);
}
void
proto_cmd_reload(struct proto *p, uint dir, int cnt UNUSED)
{
struct channel *c;
if (p->disabled)
{
cli_msg(-8, "%s: already disabled", p->name);
return;
}
/* If the protocol in not UP, it has no routes */
if (p->proto_state != PS_UP)
return;
/* All channels must support reload */
if (dir != CMD_RELOAD_OUT)
WALK_LIST(c, p->channels)
if (!channel_reloadable(c))
{
cli_msg(-8006, "%s: reload failed", p->name);
return;
}
log(L_INFO "Reloading protocol %s", p->name);
/* re-importing routes */
if (dir != CMD_RELOAD_OUT)
WALK_LIST(c, p->channels)
channel_request_reload(c);
/* re-exporting routes */
if (dir != CMD_RELOAD_IN)
WALK_LIST(c, p->channels)
channel_request_feeding(c);
cli_msg(-15, "%s: reloading", p->name);
}
void
proto_cmd_debug(struct proto *p, uint mask, int cnt UNUSED)
{
p->debug = mask;
}
void
proto_cmd_mrtdump(struct proto *p, uint mask, int cnt UNUSED)
{
p->mrtdump = mask;
}
static void
proto_apply_cmd_symbol(struct symbol *s, void (* cmd)(struct proto *, uint, int), uint arg)
{
if (s->class != SYM_PROTO)
{
cli_msg(9002, "%s is not a protocol", s->name);
return;
}
cmd(((struct proto_config *)s->def)->proto, arg, 0);
cli_msg(0, "");
}
static void
proto_apply_cmd_patt(char *patt, void (* cmd)(struct proto *, uint, int), uint arg)
{
struct proto *p;
int cnt = 0;
WALK_LIST(p, proto_list)
if (!patt || patmatch(patt, p->name))
cmd(p, arg, cnt++);
if (!cnt)
cli_msg(8003, "No protocols match");
else
cli_msg(0, "");
}
void
proto_apply_cmd(struct proto_spec ps, void (* cmd)(struct proto *, uint, int),
int restricted, uint arg)
{
if (restricted && cli_access_restricted())
return;
if (ps.patt)
proto_apply_cmd_patt(ps.ptr, cmd, arg);
else
proto_apply_cmd_symbol(ps.ptr, cmd, arg);
}
struct proto *
proto_get_named(struct symbol *sym, struct protocol *pr)
{
struct proto *p, *q;
if (sym)
{
if (sym->class != SYM_PROTO)
cf_error("%s: Not a protocol", sym->name);
p = ((struct proto_config *) sym->def)->proto;
if (!p || p->proto != pr)
cf_error("%s: Not a %s protocol", sym->name, pr->name);
}
else
{
p = NULL;
WALK_LIST(q, proto_list)
if ((q->proto == pr) && (q->proto_state != PS_DOWN))
{
if (p)
cf_error("There are multiple %s protocols running", pr->name);
p = q;
}
if (!p)
cf_error("There is no %s protocol running", pr->name);
}
return p;
}
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