bird/nest/proto.c

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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
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#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"
static pool *proto_pool;
static list protocol_list;
static list proto_list;
#define WALK_PROTO_LIST(p) do { \
node *nn; \
WALK_LIST(nn, proto_list) { \
struct proto *p = SKIP_BACK(struct proto, glob_node, nn);
#define WALK_PROTO_LIST_END } } while(0)
#define PD(pr, msg, args...) do { if (pr->debug & D_STATES) { log(L_TRACE "%s: " msg, pr->name , ## args); } } while(0)
list active_proto_list;
static list inactive_proto_list;
static list initial_proto_list;
static list flush_proto_list;
static event *proto_flush_event;
static char *p_states[] = { "DOWN", "START", "UP", "STOP" };
static char *c_states[] = { "HUNGRY", "FEEDING", "HAPPY", "FLUSHING" };
static void proto_flush_all(void *);
static void proto_rethink_goal(struct proto *p);
static char *proto_state_name(struct proto *p);
static void
proto_enqueue(list *l, struct proto *p)
{
add_tail(l, &p->n);
p->last_state_change = now;
}
static void
proto_relink(struct proto *p)
{
list *l;
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;
rem_node(&p->n);
switch (p->core_state)
{
case FS_HAPPY:
l = &active_proto_list;
break;
case FS_FLUSHING:
l = &flush_proto_list;
break;
default:
l = &inactive_proto_list;
}
proto_enqueue(l, p);
}
/**
* proto_new - create a new protocol instance
* @c: protocol configuration
* @size: size of protocol data structure (each protocol instance is represented by
* a structure starting with generic part [struct &proto] and continued
* with data specific to the protocol)
*
* When a new configuration has been read in, the core code starts
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* 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.
*/
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void *
proto_new(struct proto_config *c, unsigned size)
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{
struct protocol *pr = c->protocol;
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struct proto *p = mb_allocz(proto_pool, size);
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p->cf = c;
p->debug = c->debug;
p->name = c->name;
p->preference = c->preference;
p->disabled = c->disabled;
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p->proto = pr;
p->table = c->table->table;
p->in_filter = c->in_filter;
p->out_filter = c->out_filter;
p->min_scope = SCOPE_SITE;
p->hash_key = random_u32();
c->proto = p;
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return p;
}
static void
proto_init_instance(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);
p->attn = ev_new(p->pool);
p->attn->data = p;
rt_lock_table(p->table);
}
/**
* proto_add_announce_hook - connect protocol to a routing table
* @p: protocol instance
* @t: routing table to connect to
*
* This function creates a connection between the protocol instance @p
* and the routing table @t, making the protocol hear all changes in
* the table.
*
* Unless you want to listen to multiple routing tables (as the Pipe
* protocol does), you needn't to worry about this function since the
* connection to the protocol's primary routing table is initialized
* automatically by the core code.
*/
struct announce_hook *
proto_add_announce_hook(struct proto *p, struct rtable *t)
{
struct announce_hook *h;
if (!p->rt_notify)
return NULL;
DBG("Connecting protocol %s to table %s\n", p->name, t->name);
PD(p, "Connected to table %s", t->name);
h = mb_alloc(p->pool, sizeof(struct announce_hook));
h->table = t;
h->proto = p;
h->next = p->ahooks;
p->ahooks = h;
add_tail(&t->hooks, &h->n);
return h;
}
static void
proto_flush_hooks(struct proto *p)
{
struct announce_hook *h;
for(h=p->ahooks; h; h=h->next)
rem_node(&h->n);
p->ahooks = NULL;
}
/**
* proto_config_new - create a new protocol configuration
* @pr: protocol the configuration will belong to
* @size: size of the structure including generic data
*
* 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.
*/
void *
proto_config_new(struct protocol *pr, unsigned size)
{
struct proto_config *c = cfg_allocz(size);
add_tail(&new_config->protos, &c->n);
c->global = new_config;
c->protocol = pr;
c->name = pr->name;
c->out_filter = FILTER_REJECT;
c->table = c->global->master_rtc;
c->debug = new_config->proto_default_debug;
return c;
}
/**
* 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)
{
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struct protocol *p;
init_list(&c->protos);
DBG("Protocol preconfig:");
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WALK_LIST(p, protocol_list)
{
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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}
/**
* protos_postconfig - post-configuration processing
* @c: new configuration
*
* This function calls the postconfig() hooks of all protocol
* instances specified in configuration @c.
*/
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void
protos_postconfig(struct config *c)
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{
struct proto_config *x;
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struct protocol *p;
DBG("Protocol postconfig:");
WALK_LIST(x, c->protos)
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{
DBG(" %s", x->name);
p = x->protocol;
if (p->postconfig)
p->postconfig(x);
}
DBG("\n");
}
static struct proto *
proto_init(struct proto_config *c)
{
struct protocol *p = c->protocol;
struct proto *q = p->init(c);
q->proto_state = PS_DOWN;
q->core_state = FS_HUNGRY;
proto_enqueue(&initial_proto_list, q);
add_tail(&proto_list, &q->glob_node);
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PD(q, "Initializing%s", q->disabled ? " [disabled]" : "");
return q;
}
/**
* 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)
*
* 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 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)
{
struct proto_config *oc, *nc;
struct proto *p, *n;
DBG("protos_commit:\n");
if (old)
{
WALK_LIST(oc, old->protos)
{
struct proto *p = oc->proto;
struct symbol *sym = cf_find_symbol(oc->name);
if (sym && sym->class == SYM_PROTO && !new->shutdown)
{
/* Found match, let's check if we can smoothly switch to new configuration */
nc = sym->def;
if (!force_reconfig
&& nc->protocol == oc->protocol
&& nc->preference == oc->preference
&& nc->disabled == oc->disabled
&& nc->table->table == oc->table->table
&& filter_same(nc->in_filter, oc->in_filter)
&& filter_same(nc->out_filter, oc->out_filter)
&& p->proto_state != PS_DOWN)
{
/* Generic attributes match, try converting them and then ask the protocol */
p->debug = nc->debug;
if (p->proto->reconfigure && p->proto->reconfigure(p, nc))
{
DBG("\t%s: same\n", oc->name);
PD(p, "Reconfigured");
p->cf = nc;
p->name = nc->name;
p->in_filter = nc->in_filter;
p->out_filter = nc->out_filter;
nc->proto = p;
continue;
}
}
/* Unsuccessful, force reconfig */
DBG("\t%s: power cycling\n", oc->name);
PD(p, "Reconfiguration failed, restarting");
p->cf_new = nc;
nc->proto = p;
}
else
{
DBG("\t%s: deleting\n", oc->name);
PD(p, "Unconfigured");
p->cf_new = NULL;
}
p->reconfiguring = 1;
config_add_obstacle(old);
proto_rethink_goal(p);
}
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}
WALK_LIST(nc, new->protos)
if (!nc->proto)
{
DBG("\t%s: adding\n", nc->name);
proto_init(nc);
}
DBG("\tdone\n");
DBG("Protocol start\n");
WALK_LIST_DELSAFE(p, n, initial_proto_list)
proto_rethink_goal(p);
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}
static void
proto_rethink_goal(struct proto *p)
{
struct protocol *q;
if (p->reconfiguring && p->core_state == FS_HUNGRY && p->proto_state == PS_DOWN)
{
struct proto_config *nc = p->cf_new;
DBG("%s has shut down for reconfiguration\n", p->name);
config_del_obstacle(p->cf->global);
rem_node(&p->n);
rem_node(&p->glob_node);
mb_free(p);
if (!nc)
return;
p = proto_init(nc);
}
/* Determine what state we want to reach */
if (p->disabled || p->reconfiguring)
{
p->core_goal = FS_HUNGRY;
if (p->core_state == FS_HUNGRY && p->proto_state == PS_DOWN)
return;
}
else
{
p->core_goal = FS_HAPPY;
if (p->core_state == FS_HAPPY && p->proto_state == PS_UP)
return;
}
q = p->proto;
if (p->core_goal == FS_HAPPY) /* Going up */
{
if (p->core_state == FS_HUNGRY && p->proto_state == PS_DOWN)
{
DBG("Kicking %s up\n", p->name);
PD(p, "Starting");
proto_init_instance(p);
proto_notify_state(p, (q->start ? q->start(p) : PS_UP));
}
}
else /* Going down */
{
if (p->proto_state == PS_START || p->proto_state == PS_UP)
{
DBG("Kicking %s down\n", p->name);
PD(p, "Shutting down");
proto_notify_state(p, (q->shutdown ? q->shutdown(p) : PS_DOWN));
}
}
}
/**
* 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)
{
struct proto *p;
debug("Protocols:\n");
WALK_LIST(p, active_proto_list)
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{
debug(" protocol %s state %s/%s\n", p->name,
p_states[p->proto_state], c_states[p->core_state]);
if (p->in_filter)
debug("\tInput filter: %s\n", filter_name(p->in_filter));
if (p->out_filter != FILTER_REJECT)
debug("\tOutput filter: %s\n", filter_name(p->out_filter));
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if (p->disabled)
debug("\tDISABLED\n");
else if (p->proto->dump)
p->proto->dump(p);
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}
WALK_LIST(p, inactive_proto_list)
debug(" inactive %s: state %s/%s\n", p->name, p_states[p->proto_state], c_states[p->core_state]);
WALK_LIST(p, initial_proto_list)
debug(" initial %s\n", p->name);
WALK_LIST(p, flush_proto_list)
debug(" flushing %s\n", p->name);
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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
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* 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;
}
}
/**
* 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(&protocol_list);
init_list(&proto_list);
init_list(&active_proto_list);
init_list(&inactive_proto_list);
init_list(&initial_proto_list);
init_list(&flush_proto_list);
proto_build(&proto_device);
#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);
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#endif
#ifdef CONFIG_BGP
proto_build(&proto_bgp);
#endif
proto_pool = rp_new(&root_pool, "Protocols");
proto_flush_event = ev_new(proto_pool);
proto_flush_event->hook = proto_flush_all;
}
static void
proto_fell_down(struct proto *p)
{
DBG("Protocol %s down\n", p->name);
rt_unlock_table(p->table);
proto_rethink_goal(p);
}
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static void
proto_feed_more(void *P)
{
struct proto *p = P;
DBG("Feeding protocol %s continued\n", p->name);
if (p->core_state != FS_FEEDING)
return;
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if (rt_feed_baby(p))
{
p->core_state = FS_HAPPY;
proto_relink(p);
DBG("Protocol %s up and running\n", p->name);
}
else
{
p->attn->hook = proto_feed_more;
ev_schedule(p->attn); /* Will continue later... */
}
}
static void
proto_feed(void *P)
{
struct proto *p = P;
DBG("Feeding protocol %s\n", p->name);
proto_add_announce_hook(p, p->table);
if_feed_baby(p);
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proto_feed_more(P);
}
/**
* 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.
*/
void
proto_notify_state(struct proto *p, unsigned ps)
{
unsigned ops = p->proto_state;
unsigned cs = p->core_state;
DBG("%s reporting state transition %s/%s -> */%s\n", p->name, c_states[cs], p_states[ops], p_states[ps]);
if (ops == ps)
return;
switch (ps)
{
case PS_DOWN:
if (cs == FS_HUNGRY) /* Shutdown finished */
{
p->proto_state = ps;
proto_fell_down(p);
return; /* The protocol might have ceased to exist */
}
else if (cs == FS_FLUSHING) /* Still flushing... */
;
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else
{
if (cs == FS_FEEDING) /* Need to abort feeding */
rt_feed_baby_abort(p);
goto schedule_flush; /* Need to start flushing */
}
break;
case PS_START:
ASSERT(ops == PS_DOWN);
ASSERT(cs == FS_HUNGRY);
break;
case PS_UP:
ASSERT(ops == PS_DOWN || ops == PS_START);
ASSERT(cs == FS_HUNGRY);
DBG("%s: Scheduling meal\n", p->name);
cs = FS_FEEDING;
p->attn->hook = proto_feed;
ev_schedule(p->attn);
break;
case PS_STOP:
if (ops != PS_DOWN)
{
schedule_flush:
DBG("%s: Scheduling flush\n", p->name);
proto_flush_hooks(p);
cs = FS_FLUSHING;
ev_schedule(proto_flush_event);
}
break;
default:
bug("Invalid state transition for %s from %s/%s to */%s", p->name, c_states[cs], p_states[ops], p_states[ps]);
}
p->proto_state = ps;
p->core_state = cs;
proto_relink(p);
}
static void
proto_flush_all(void *unused UNUSED)
{
struct proto *p;
rt_prune_all();
neigh_prune();
while ((p = HEAD(flush_proto_list))->n.next)
{
DBG("Flushing protocol %s\n", p->name);
rfree(p->pool);
p->pool = NULL;
p->core_state = FS_HUNGRY;
proto_relink(p);
proto_fell_down(p);
}
}
/*
* CLI Commands
*/
static char *
proto_state_name(struct proto *p)
{
#define P(x,y) ((x << 4) | y)
switch (P(p->proto_state, p->core_state))
{
case P(PS_DOWN, FS_HUNGRY): return "down";
case P(PS_START, FS_HUNGRY): return "start";
case P(PS_UP, FS_HUNGRY):
case P(PS_UP, FS_FEEDING): return "feed";
case P(PS_STOP, FS_HUNGRY): return "stop";
case P(PS_UP, FS_HAPPY): return "up";
case P(PS_STOP, FS_FLUSHING):
case P(PS_DOWN, FS_FLUSHING): return "flush";
default: return "???";
}
#undef P
}
static void
proto_do_show(struct proto *p, int verbose)
{
byte buf[256], reltime[TM_RELTIME_BUFFER_SIZE];
buf[0] = 0;
if (p->proto->get_status)
p->proto->get_status(p, buf);
tm_format_reltime(reltime, p->last_state_change);
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cli_msg(-1002, "%-8s %-8s %-8s %-5s %-5s %s",
p->name,
p->proto->name,
p->table->name,
proto_state_name(p),
reltime,
buf);
if (verbose)
{
cli_msg(-1006, "\tPreference: %d", p->preference);
cli_msg(-1006, "\tInput filter: %s", filter_name(p->in_filter));
cli_msg(-1006, "\tOutput filter: %s", filter_name(p->out_filter));
}
}
void
proto_show(struct symbol *s, int verbose)
{
if (s && s->class != SYM_PROTO)
{
cli_msg(9002, "%s is not a protocol", s->name);
return;
}
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cli_msg(-2002, "name proto table state since info");
if (s)
proto_do_show(((struct proto_config *)s->def)->proto, verbose);
else
{
WALK_PROTO_LIST(p)
proto_do_show(p, verbose);
WALK_PROTO_LIST_END;
}
cli_msg(0, "");
}
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, active_proto_list)
if (q->proto == pr)
{
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;
}
void
proto_xxable(char *pattern, int xx)
{
int cnt = 0;
WALK_PROTO_LIST(p)
if (patmatch(pattern, p->name))
{
cnt++;
switch (xx)
{
case 0:
if (p->disabled)
cli_msg(-8, "%s: already disabled", p->name);
else
{
cli_msg(-9, "%s: disabled", p->name);
p->disabled = 1;
}
break;
case 1:
if (!p->disabled)
cli_msg(-10, "%s: already enabled", p->name);
else
{
cli_msg(-11, "%s: enabled", p->name);
p->disabled = 0;
}
break;
case 2:
if (p->disabled)
cli_msg(-8, "%s: already disabled", p->name);
else
{
p->disabled = 1;
proto_rethink_goal(p);
p->disabled = 0;
cli_msg(-12, "%s: restarted", p->name);
}
break;
default:
ASSERT(0);
}
proto_rethink_goal(p);
}
WALK_PROTO_LIST_END;
if (!cnt)
cli_msg(8003, "No protocols match");
else
cli_msg(0, "");
}
Added protocol debugging flags (protocol.h: D_xxx), parsing of them in configuration files and commands for manipulating them. Current debug message policy: o D_STATES, D_ROUTES and D_FILTERS are handled in generic code. o Other debug flags should be handled in the protocols and whenever the flag is set, the corresponding messages should be printed using calls to log(L_TRACE, ...), each message prefixed with the name of the protocol instance. These messages should cover the whole normal operation of the protocol and should be useful for an administrator trying to understand what does the protocol behave on his network or who is attempting to diagnose network problems. If your messages don't fit to the categories I've defined, feel free to add your own ones (by adding them to protocol.h and on two places in nest/config.Y), but please try to keep the categories as general as possible (i.e., not tied to your protocol). o Internal debug messages not interesting even to an experienced user should be printed by calling DBG() which is either void or a call to debug() depending on setting of the LOCAL_DEBUG symbol at the top of your source. o Dump functions (proto->dump etc.) should call debug() to print their messages. o If you are doing any internal consistency checks, use ASSERT or bug(). o Nobody shall ever call printf() or any other stdio functions. Also please try to log any protocol errors you encounter and tag them with the appropriate message category (usually L_REMOTE or L_AUTH). Always carefully check contents of any message field you receive and verify all IP addresses you work with (by calling ipa_classify() or by using the neighbour cache if you want to check direct connectedness as well).
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void
proto_debug(char *pattern, unsigned int mask)
{
int cnt = 0;
WALK_PROTO_LIST(p)
if (patmatch(pattern, p->name))
{
cnt++;
p->debug = mask;
}
WALK_PROTO_LIST_END;
if (!cnt)
cli_msg(8003, "No protocols match");
else
cli_msg(0, "");
}