pf: make pf_purge_rule run fine with a main ruleset (1)

[Mike Belopuhov]

Hi,

Here's the first diff in a series of three to finish the "once"
feature.

This one was prompted by the discussion with Alexandr Nedvedicky
<alexandr ! nedvedicky at oracle ! com>.

Apart from some minor code reshuffling the big change is that we
start with a ruleset pointer assigned to pf_main_ruleset so that
pf_purge_rule doesn't get called with a NULL.

OK?

diff --git sys/net/pf.c sys/net/pf.c
index a180469..9832e47 100644
--- sys/net/pf.c
+++ sys/net/pf.c
@@ -3163,10 +3163,11 @@ pf_test_rule(struct pf_pdesc *pd, struct pf_rule **rm, 
struct pf_state **sm,
                }
                break;
 #endif /* INET6 */
        }
 
+       ruleset = &pf_main_ruleset;
        r = TAILQ_FIRST(pf_main_ruleset.rules.active.ptr);
        while (r != NULL) {
                r->evaluations++;
                PF_TEST_ATTRIB((pfi_kif_match(r->kif, pd->kif) == r->ifnot),
                        r->skip[PF_SKIP_IFP].ptr);
diff --git sys/net/pf_ioctl.c sys/net/pf_ioctl.c
index 56330d9..2868297 100644
--- sys/net/pf_ioctl.c
+++ sys/net/pf_ioctl.c
@@ -308,24 +308,19 @@ pf_rm_rule(struct pf_rulequeue *rulequeue, struct pf_rule 
*rule)
 }
 
 void
 pf_purge_rule(struct pf_ruleset *ruleset, struct pf_rule *rule)
 {
-       u_int32_t                nr;
+       u_int32_t        nr = 0;
 
-       if (ruleset == NULL || ruleset->anchor == NULL)
-               return;
+       KASSERT(ruleset != NULL && rule != NULL);
 
        pf_rm_rule(ruleset->rules.active.ptr, rule);
        ruleset->rules.active.rcount--;
-
-       nr = 0;
        TAILQ_FOREACH(rule, ruleset->rules.active.ptr, entries)
                rule->nr = nr++;
-
        ruleset->rules.active.ticket++;
-
        pf_calc_skip_steps(ruleset->rules.active.ptr);
        pf_remove_if_empty_ruleset(ruleset);
 }
 
 u_int16_t