Introduce a semaphore to protect intermediate state from different RTR

sessions to leak into the RDE via rtr_recalc. Only run rtr_recalc when
the last or only RTR session is done with the update. Run a new timer
along to ensure that the semaphore is not hold forever. The timeout
is currently a very generous 60sec, no RTR cache should be that slow.
OK tb@

diff --git a/usr.sbin/bgpd/bgpd.h b/usr.sbin/bgpd/bgpd.h
index 4cec43b..ecee4ef 100644 (file)
--- a/usr.sbin/bgpd/bgpd.h
+++ b/usr.sbin/bgpd/bgpd.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: bgpd.h,v 1.466 2023/03/28 12:06:15 claudio Exp $ */
+/*     $OpenBSD: bgpd.h,v 1.467 2023/03/28 12:15:23 claudio Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -1639,6 +1639,7 @@ static const char * const timernames[] = {
        "RTR RefreshTimer",
        "RTR RetryTimer",
        "RTR ExpireTimer",
+       "RTR ActiveTimer",
        ""
 };
 

diff --git a/usr.sbin/bgpd/rtr.c b/usr.sbin/bgpd/rtr.c
index 178679e..2c3b18c 100644 (file)
--- a/usr.sbin/bgpd/rtr.c
+++ b/usr.sbin/bgpd/rtr.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: rtr.c,v 1.12 2023/03/09 17:21:21 claudio Exp $ */
+/*     $OpenBSD: rtr.c,v 1.13 2023/03/28 12:15:23 claudio Exp $ */
 
 /*
  * Copyright (c) 2020 Claudio Jeker <claudio@openbsd.org>
@@ -40,6 +40,7 @@ static struct imsgbuf         *ibuf_main;
 static struct imsgbuf          *ibuf_rde;
 static struct bgpd_config      *conf, *nconf;
 static struct timer_head        expire_timer;
+static int                      rtr_recalc_semaphore;
 
 static void
 rtr_sighdlr(int sig)
@@ -58,6 +59,20 @@ rtr_sighdlr(int sig)
 
 #define EXPIRE_TIMEOUT 300
 
+void
+rtr_sem_acquire(int cnt)
+{
+       rtr_recalc_semaphore += cnt;
+}
+
+void
+rtr_sem_release(int cnt)
+{
+       rtr_recalc_semaphore -= cnt;
+       if (rtr_recalc_semaphore < 0)
+               fatalx("rtr recalc semaphore underflow");
+}
+
 /*
  * Every EXPIRE_TIMEOUT seconds traverse the static roa-set table and expire
  * all elements where the expires timestamp is smaller or equal to now.
@@ -542,6 +557,9 @@ rtr_recalc(void)
        struct aspa_set *aspa;
        struct aspa_prep ap = { 0 };
 
+       if (rtr_recalc_semaphore > 0)
+               return;
+
        RB_INIT(&rt);
        RB_INIT(&at);
 

diff --git a/usr.sbin/bgpd/rtr_proto.c b/usr.sbin/bgpd/rtr_proto.c
index c13d0ed..bfa74c4 100644 (file)
--- a/usr.sbin/bgpd/rtr_proto.c
+++ b/usr.sbin/bgpd/rtr_proto.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: rtr_proto.c,v 1.15 2023/03/17 11:14:10 claudio Exp $ */
+/*     $OpenBSD: rtr_proto.c,v 1.16 2023/03/28 12:15:23 claudio Exp $ */
 
 /*
  * Copyright (c) 2020 Claudio Jeker <claudio@openbsd.org>
@@ -40,6 +40,7 @@ struct rtr_header {
 #define RTR_DEFAULT_REFRESH    3600
 #define RTR_DEFAULT_RETRY      600
 #define RTR_DEFAULT_EXPIRE     7200
+#define RTR_DEFAULT_ACTIVE     60
 
 enum rtr_pdu_type {
        SERIAL_NOTIFY = 0,
@@ -99,6 +100,7 @@ enum rtr_event {
        RTR_EVNT_TIMER_REFRESH,
        RTR_EVNT_TIMER_RETRY,
        RTR_EVNT_TIMER_EXPIRE,
+       RTR_EVNT_TIMER_ACTIVE,
        RTR_EVNT_SEND_ERROR,
        RTR_EVNT_SERIAL_NOTIFY,
        RTR_EVNT_CACHE_RESPONSE,
@@ -116,6 +118,7 @@ static const char *rtr_eventnames[] = {
        "refresh timer expired",
        "retry timer expired",
        "expire timer expired",
+       "activity timer expired",
        "sent error",
        "serial notify received",
        "cache response received",
@@ -157,8 +160,10 @@ struct rtr_session {
        uint32_t                        refresh;
        uint32_t                        retry;
        uint32_t                        expire;
+       uint32_t                        active;
        int                             session_id;
        int                             fd;
+       int                             active_lock;
        enum rtr_state                  state;
        enum reconf_action              reconf_action;
        enum rtr_error                  last_sent_error;
@@ -1033,18 +1038,30 @@ rtr_fsm(struct rtr_session *rs, enum rtr_event event)
                rtr_reset_cache(rs);
                rtr_recalc();
                break;
+       case RTR_EVNT_TIMER_ACTIVE:
+               log_warnx("rtr %s: activity timer fired", log_rtr(rs));
+               rtr_sem_release(rs->active_lock);
+               rtr_recalc();
+               rs->active_lock = 0;
+               break;
        case RTR_EVNT_CACHE_RESPONSE:
                rs->state = RTR_STATE_ACTIVE;
                timer_stop(&rs->timers, Timer_Rtr_Refresh);
                timer_stop(&rs->timers, Timer_Rtr_Retry);
-               /* XXX start timer to limit active time */
+               timer_set(&rs->timers, Timer_Rtr_Active, rs->active);
+               /* prevent rtr_recalc from running while active */
+               rs->active_lock = 1;
+               rtr_sem_acquire(rs->active_lock);
                break;
        case RTR_EVNT_END_OF_DATA:
                /* start refresh and expire timers */
                timer_set(&rs->timers, Timer_Rtr_Refresh, rs->refresh);
                timer_set(&rs->timers, Timer_Rtr_Expire, rs->expire);
+               timer_stop(&rs->timers, Timer_Rtr_Active);
                rs->state = RTR_STATE_IDLE;
+               rtr_sem_release(rs->active_lock);
                rtr_recalc();
+               rs->active_lock = 0;
                break;
        case RTR_EVNT_CACHE_RESET:
                rtr_reset_cache(rs);
@@ -1164,6 +1181,9 @@ rtr_check_events(struct pollfd *pfds, size_t npfds)
                        case Timer_Rtr_Expire:
                                rtr_fsm(rs, RTR_EVNT_TIMER_EXPIRE);
                                break;
+                       case Timer_Rtr_Active:
+                               rtr_fsm(rs, RTR_EVNT_TIMER_ACTIVE);
+                               break;
                        default:
                                fatalx("King Bula lost in time");
                        }
@@ -1237,6 +1257,7 @@ rtr_new(uint32_t id, char *descr)
        rs->refresh = RTR_DEFAULT_REFRESH;
        rs->retry = RTR_DEFAULT_RETRY;
        rs->expire = RTR_DEFAULT_EXPIRE;
+       rs->active = RTR_DEFAULT_ACTIVE;
        rs->state = RTR_STATE_CLOSED;
        rs->reconf_action = RECONF_REINIT;
        rs->last_recv_error = NO_ERROR;

diff --git a/usr.sbin/bgpd/session.h b/usr.sbin/bgpd/session.h
index c9e6b21..65e96d6 100644 (file)
--- a/usr.sbin/bgpd/session.h
+++ b/usr.sbin/bgpd/session.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: session.h,v 1.161 2023/03/09 17:21:21 claudio Exp $ */
+/*     $OpenBSD: session.h,v 1.162 2023/03/28 12:15:23 claudio Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -201,6 +201,7 @@ enum Timer {
        Timer_Rtr_Refresh,
        Timer_Rtr_Retry,
        Timer_Rtr_Expire,
+       Timer_Rtr_Active,
        Timer_Max
 };
 
@@ -334,6 +335,8 @@ void                         rtr_shutdown(void);
 void                    rtr_show(struct rtr_session *, pid_t);
 
 /* rtr.c */
+void   rtr_sem_acquire(int);
+void   rtr_sem_release(int);
 void   rtr_roa_insert(struct roa_tree *, struct roa *);
 void   rtr_aspa_insert(struct aspa_tree *, struct aspa_set *);
 void   rtr_main(int, int);