Session timer enhancement

include/nat64/mod/stateful/bib/db.h

@@ -96,7 +96,8 @@ int bib_find(struct bib *db, struct tuple *tuple,
 		struct bib_session *result);
 int bib_add_session(struct bib *db, struct session_entry *new,
 		struct collision_cb *cb);
-void bib_clean(struct bib *db, struct net *ns);
+void bib_clean(struct bib *db, struct net *ns, u64 *max_session_rm,
+		bool *pending_rm);
 
 /* These are used by userspace request handling. */
 

include/nat64/mod/stateful/bib/pkt_queue.h

@@ -146,7 +146,8 @@ void pktqueue_put_node(struct pktqueue_session *node);
  * outside.
  */
 unsigned int pktqueue_prepare_clean(struct pktqueue *queue,
-		struct list_head *probes);
+		struct list_head *probes, u64 *max_session_rm, u64 *sessions_rm,
+		bool *pending_rm);
 /**
  * Sends the ICMP errors contained in the @probe list.
  */

include/nat64/mod/stateful/global_timer.h

@@ -0,0 +1,13 @@
+#ifndef _JOOL_MOD_GLOBAL_TIMER_H
+#define _JOOL_MOD_GLOBAL_TIMER_H
+
+/**
+ * @file
+ * Timer used to trigger some of Jool's events. Always runs, as long as Jool
+ * is modprobed. At time of writing, this induces fragment expiration.
+ */
+
+int global_timer_init(void);
+void global_timer_destroy(void);
+
+#endif /* _JOOL_MOD_GLOBAL_TIMER_H */

include/nat64/mod/stateful/session_timer.h

@@ -0,0 +1,13 @@
+#ifndef _JOOL_MOD_SESSION_TIMER_H
+#define _JOOL_MOD_SESSION_TIMER_H
+
+/**
+ * @file
+ * Timer used to trigger some of Jool's events. Always runs, as long as Jool
+ * is modprobed. At time of writing, this induces session expiration.
+ */
+
+int session_timer_init(void);
+void session_timer_destroy(void);
+
+#endif /* _JOOL_MOD_SESSION_TIMER_H */

mod/stateful/Kbuild

@@ -56,7 +56,8 @@ jool += bib/db.o
 jool += bib/entry.o
 jool += bib/pkt_queue.o
 
-jool += timer.o
+jool += global_timer.o
+jool += session_timer.o
 jool += fragment_db.o
 jool += determine_incoming_tuple.o
 jool += filtering_and_updating.o

mod/stateful/bib/db.c

@@ -1972,38 +1972,63 @@ int bib_add_session(struct bib *db,
 
 static void __clean(struct expire_timer *expirer,
 		struct bib_table *table,
-		struct list_head *probes)
+		struct list_head *probes,
+		u64 *max_session_rm,
+		u64 *sessions_rm,
+		bool *pending_rm)
 {
 	struct tabled_session *session;
 	struct tabled_session *tmp;
 	struct collision_cb cb;
+	u64 session_cnt;
 
 	cb.cb = expirer->decide_fate_cb;
 	cb.arg = NULL;
 
+	log_debug("++ TOTAL Session count = %llu", table->session_count);
+
 	list_for_each_entry_safe(session, tmp, &expirer->sessions, list_hook) {
 		/*
 		 * "list" is sorted by expiration date,
 		 * so stop on the first unexpired session.
 		 */
 		if (time_before(jiffies, session->update_time + expirer->timeout))
 			break;
+
+		if (*pending_rm || *sessions_rm >= *max_session_rm) {
+			*pending_rm = 1;
+			log_debug("++ Session pending to rem");
+			break;
+		}
+		session_cnt = table->session_count;
 		decide_fate(&cb, table, session, probes);
-	}
+		*sessions_rm += session_cnt - table->session_count;
+	};
 }
 
-static void clean_table(struct bib_table *table, struct net *ns)
+static void clean_table(struct bib_table *table,
+		struct net *ns,
+		u64 *max_session_rm,
+		u64 *sessions_rm,
+		bool *pending_rm)
 {
 	LIST_HEAD(probes);
 	LIST_HEAD(icmps);
 
+	if (*pending_rm)
+		return;
+
 	spin_lock_bh(&table->lock);
-	__clean(&table->est_timer, table, &probes);
-	__clean(&table->trans_timer, table, &probes);
-	__clean(&table->syn4_timer, table, &probes);
+	__clean(&table->est_timer, table, &probes, max_session_rm, sessions_rm,
+			pending_rm);
+	__clean(&table->trans_timer, table, &probes, max_session_rm, sessions_rm,
+			pending_rm);
+	__clean(&table->syn4_timer, table, &probes, max_session_rm, sessions_rm,
+			pending_rm);
+
 	if (table->pkt_queue) {
-		table->pkt_count -= pktqueue_prepare_clean(table->pkt_queue,
-				&icmps);
+		table->pkt_count -= pktqueue_prepare_clean(table->pkt_queue, &icmps,
+				max_session_rm, sessions_rm, pending_rm);
 	}
 	spin_unlock_bh(&table->lock);
 
@@ -2014,11 +2039,16 @@ static void clean_table(struct bib_table *table, struct net *ns)
 /**
  * Forgets or downgrades (from EST to TRANS) old sessions.
  */
-void bib_clean(struct bib *db, struct net *ns)
-{
-	clean_table(&db->udp, ns);
-	clean_table(&db->tcp, ns);
-	clean_table(&db->icmp, ns);
+void bib_clean(struct bib *db,
+		struct net *ns,
+		u64 *max_session_rm,
+		bool *pending_rm)
+{
+	u64 sessions_rm = 0;
+	clean_table(&db->udp, ns, max_session_rm, &sessions_rm, pending_rm);
+	clean_table(&db->tcp, ns, max_session_rm, &sessions_rm, pending_rm);
+	clean_table(&db->icmp, ns, max_session_rm, &sessions_rm, pending_rm);
+	log_debug("+ Session total removed: %llu", sessions_rm);
 }
 
 static struct rb_node *find_starting_point(struct bib_table *table,

mod/stateful/bib/pkt_queue.c

@@ -197,7 +197,10 @@ void pktqueue_put_node(struct pktqueue_session *node)
  * @probes.
  */
 unsigned int pktqueue_prepare_clean(struct pktqueue *queue,
-		struct list_head *probes)
+		struct list_head *probes,
+		u64 *max_session_rm,
+		u64 *sessions_rm,
+		bool *pending_rm)
 {
 	struct pktqueue_session *node, *tmp;
 	const unsigned long TIMEOUT = get_timeout();
@@ -211,9 +214,15 @@ unsigned int pktqueue_prepare_clean(struct pktqueue *queue,
 		if (time_before(jiffies, node->update_time + TIMEOUT))
 			break;
 
+		if (*pending_rm || *sessions_rm >= *max_session_rm) {
+			*pending_rm = 1;
+			log_debug("++ Session pending to rem in pktqueue");
+			break;
+		}
 		rm(queue, node);
 		list_add(&node->list_hook, probes);
 		removed++;
+		(*sessions_rm)++;
 	}
 
 	return removed;

mod/stateful/timer.c → mod/stateful/global_timer.c

@@ -1,4 +1,4 @@
-#include "nat64/mod/stateful/timer.h"
+#include "nat64/mod/stateful/global_timer.h"
 
 #include "nat64/mod/common/xlator.h"
 #include "nat64/mod/stateful/fragment_db.h"
@@ -12,7 +12,6 @@ static struct timer_list timer;
 static int clean_state(struct xlator *jool, void *args)
 {
 	fragdb_clean(jool->nat64.frag);
-	bib_clean(jool->nat64.bib, jool->ns);
 	joold_clean(jool->nat64.joold, jool->nat64.bib);
 	return 0;
 }
@@ -26,7 +25,7 @@ static void timer_function(unsigned long arg)
 /**
  * This function should be always called *after* other init()s.
  */
-int timer_init(void)
+int global_timer_init(void)
 {
 	init_timer(&timer);
 	timer.function = timer_function;
@@ -39,7 +38,7 @@ int timer_init(void)
 /**
  * This function should be always called *before* other destroy()s.
  */
-void timer_destroy(void)
+void global_timer_destroy(void)
 {
 	del_timer_sync(&timer);
 }

mod/stateful/nf_hook.c

@@ -12,8 +12,9 @@
 #include "nat64/mod/common/xlator.h"
 #include "nat64/mod/common/nl/nl_handler.h"
 #include "nat64/mod/stateful/fragment_db.h"
+#include "nat64/mod/stateful/global_timer.h"
 #include "nat64/mod/stateful/joold.h"
-#include "nat64/mod/stateful/timer.h"
+#include "nat64/mod/stateful/session_timer.h"
 #include "nat64/mod/stateful/pool4/db.h"
 #include "nat64/mod/stateful/pool4/rfc6056.h"
 #include "nat64/mod/stateful/bib/db.h"
@@ -135,9 +136,12 @@ static int __init jool_init(void)
 	error = nlhandler_init();
 	if (error)
 		goto nlhandler_fail;
-	error = timer_init();
+	error = global_timer_init();
 	if (error)
-		goto timer_fail;
+		goto global_timer_fail;
+	error = session_timer_init();
+	if (error)
+		goto session_timer_fail;
 	error = logtime_init();
 	if (error)
 		goto logtime_fail;
@@ -161,8 +165,10 @@ static int __init jool_init(void)
 instance_fail:
 	logtime_destroy();
 logtime_fail:
-	timer_destroy();
-timer_fail:
+	session_timer_destroy();
+session_timer_fail:
+	global_timer_destroy();
+global_timer_fail:
 	nlhandler_destroy();
 nlhandler_fail:
 	xlator_destroy();
@@ -183,7 +189,8 @@ static void __exit jool_exit(void)
 	nf_unregister_hooks(nfho, ARRAY_SIZE(nfho));
 
 	logtime_destroy();
-	timer_destroy();
+	session_timer_destroy();
+	global_timer_destroy();
 	nlhandler_destroy();
 	xlator_destroy();
 	rfc6056_destroy();

mod/stateful/session_timer.c

@@ -0,0 +1,71 @@
+#include "nat64/mod/stateful/session_timer.h"
+
+#include "nat64/mod/common/xlator.h"
+#include "nat64/mod/stateful/bib/db.h"
+
+#define INITIAL_TIMER_PERIOD msecs_to_jiffies(2000)
+#define MAX_SESSIONS_RM 1024
+
+static struct timer_list timer;
+
+struct clean_params {
+	bool pend_rm;
+	u64 max_session_rm;
+};
+
+static struct clean_params sess_params;
+
+static int clean_state(struct xlator *jool, void *args)
+{
+	struct clean_params *params = args;
+	bib_clean(jool->nat64.bib, jool->ns, &params->max_session_rm,
+			&params->pend_rm);
+	return 0;
+}
+
+static void update_params(unsigned long arg)
+{
+	if (sess_params.pend_rm) {
+		timer.data = msecs_to_jiffies(jiffies_to_msecs(arg) / 2);
+		sess_params.max_session_rm <<= 1;
+		log_debug("+ Session timer NEW msecs and max_sess_rm: %u - %llu",
+				(jiffies_to_msecs(arg) / 2), sess_params.max_session_rm);
+	} else {
+		timer.data = INITIAL_TIMER_PERIOD;
+		sess_params.max_session_rm = MAX_SESSIONS_RM;
+		log_debug("+ Session timer RESET msecs and max_sess_rm: %u - %llu",
+				jiffies_to_msecs(INITIAL_TIMER_PERIOD),
+				sess_params.max_session_rm);
+	}
+	sess_params.pend_rm = 0;
+}
+
+static void timer_function(unsigned long arg)
+{
+	xlator_foreach(clean_state, &sess_params);
+	update_params(arg);
+	mod_timer(&timer, jiffies + timer.data);
+}
+
+/**
+ * This function should be always called *after* other init()s.
+ */
+int session_timer_init(void)
+{
+	init_timer(&timer);
+	timer.function = timer_function;
+	timer.expires = 0;
+	timer.data = 0;
+	sess_params.pend_rm = 0;
+	sess_params.max_session_rm = MAX_SESSIONS_RM;
+	mod_timer(&timer, jiffies + INITIAL_TIMER_PERIOD);
+	return 0;
+}
+
+/**
+ * This function should be always called *before* other destroy()s.
+ */
+void session_timer_destroy(void)
+{
+	del_timer_sync(&timer);
+}