pfsync_sendout() requires PF_LOCK()

[Alexandr Nedvedicky]

Hello,

this is yet another fall out from my experiments.  It has turned out my initial
change introduced some time ago [1] omits pfsyncintr() and pfsync_sendout().
Both functions call pfsync_sendout(), which currently requires protection
of PF_LOCK(). Without change below the test box was dying on ASSERT()
in pf_state_uref() at line 7529.

    7520 pf_state_unref(struct pf_state *s)
    7521 {
    7522         if ((s != NULL) && PF_REF_RELE(s->refcnt)) {
    7523                 /* never inserted or removed */
    7524 #if NPFSYNC > 0
    7525                 KASSERT((TAILQ_NEXT(s, sync_list) == NULL) ||
    7526                     ((TAILQ_NEXT(s, sync_list) == _Q_INVALID) &&
    7527                     (s->sync_state == PFSYNC_S_NONE)));
    7528 #endif  /* NPFSYNC */
    7529                 KASSERT((TAILQ_NEXT(s, entry_list) == NULL) ||
    7530                     (TAILQ_NEXT(s, entry_list) == _Q_INVALID));
    7531                 KASSERT((s->key[PF_SK_WIRE] == NULL) &&
    7532                     (s->key[PF_SK_STACK] == NULL));
    7533 
    7534                 pool_put(&pf_state_pl, s);
    7535         }
    7536 }

The assert was being triggered from various code paths. Most frequently
from pfsync_update_state(). Occurrence of pf_state_unref() at pf_test()
or timer thread were very rare.

OK?

thanks and
regards
sashan

[1] 
https://github.com/openbsd/src/commit/ddb22b9530d7ad1b4698803d7b6dcb21c96a3f7d#diff-9517dfce4e8db974781a4536fd38cfc1

--------8<---------------8<---------------8<------------------8<--------
diff --git a/sys/net/if_pfsync.c b/sys/net/if_pfsync.c
index 20a0136e838..e891832b3ab 100644
--- a/sys/net/if_pfsync.c
+++ b/sys/net/if_pfsync.c
@@ -1581,6 +1581,8 @@ pfsync_sendout(void)
        int offset;
        int q, count = 0;
 
+       PF_ASSERT_LOCKED();
+
        if (sc == NULL || sc->sc_len == PFSYNC_MINPKT)
                return;
 
@@ -2472,7 +2474,9 @@ void
 pfsync_timeout(void *arg)
 {
        NET_LOCK();
+       PF_LOCK();
        pfsync_sendout();
+       PF_UNLOCK();
        NET_UNLOCK();
 }
 
@@ -2480,7 +2484,9 @@ pfsync_timeout(void *arg)
 void
 pfsyncintr(void)
 {
+       PF_LOCK();
        pfsync_sendout();
+       PF_UNLOCK();
 }
 
 int