hash: New HSH_CheckBans() convenience

This function is a thin wrapper around hsh_check_bans_locked() that
behaves just like BAN_CheckObject() used to before it got folded into
ban_check_object() in 5eeabe7.

It will allow evaluating bans outside of a lookup now that bans with
request criteria can be skipped (again) in BAN_CheckObject().

bin/varnishd/cache/cache_hash.c

@@ -276,6 +276,41 @@ hsh_testmagic(void *result)
 	fprintf(stderr, ">\n");
 }
 
+/*---------------------------------------------------------------------
+ */
+
+static int
+hsh_check_bans_locked(struct worker *wrk, struct objcore *oc, struct req *req)
+{
+	struct objhead *oh;
+
+	oh = oc->objhead;
+	Lck_AssertHeld(&oh->mtx);
+
+	return (BAN_CheckObject(wrk, oc, req) > 0);
+}
+
+void
+HSH_CheckBans(struct worker *wrk, struct objcore *oc)
+{
+	struct objhead *oh;
+
+	CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
+	CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
+	oh = oc->objhead;
+	CHECK_OBJ_NOTNULL(oh, OBJHEAD_MAGIC);
+
+	if (oc->flags & OC_F_DYING)
+		return;
+
+	Lck_Lock(&oh->mtx);
+	if (hsh_check_bans_locked(wrk, oc, NULL)) {
+		oc->flags |= OC_F_DYING;
+		EXP_Remove(oc, NULL);
+	}
+	Lck_Unlock(&oh->mtx);
+}
+
 /*---------------------------------------------------------------------
  * Insert an object which magically appears out of nowhere or, more likely,
  * comes off some persistent storage device.
@@ -451,7 +486,7 @@ HSH_Lookup(struct req *req, struct objcore **ocp, struct objcore **bocp)
 		if (oc->ttl <= 0.)
 			continue;
 
-		if (BAN_CheckObject(wrk, oc, req)) {
+		if (hsh_check_bans_locked(wrk, oc, req)) {
 			oc->flags |= OC_F_DYING;
 			EXP_Remove(oc, NULL);
 			continue;

bin/varnishd/cache/cache_objhead.h

@@ -86,3 +86,4 @@ unsigned HSH_Purge(struct worker *, struct objhead *, vtim_real ttl_now,
     vtim_dur ttl, vtim_dur grace, vtim_dur keep);
 struct objcore *HSH_Private(const struct worker *wrk);
 void HSH_Cancel(struct worker *, struct objcore *, struct boc *);
+void HSH_CheckBans(struct worker *, struct objcore *);