From: bluhm <bluhm@openbsd.org>
Date: Wed, 29 Nov 2023 19:19:25 +0000 (+0000)
Subject: Run TCP syn cache timer without kernel lock.
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=0f086867d618d515cf1933bec70af3058575d4d3;p=openbsd

Run TCP syn cache timer without kernel lock.

As syn_cache_timer() uses syn cache mutex and exclusive net lock,
it does not need kernel lock.

OK mvs@
---

diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index 2a4aec3e8d8..0354ece8be2 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tcp_input.c,v 1.394 2023/11/27 20:37:15 bluhm Exp $	*/
+/*	$OpenBSD: tcp_input.c,v 1.395 2023/11/29 19:19:25 bluhm Exp $	*/
 /*	$NetBSD: tcp_input.c,v 1.23 1996/02/13 23:43:44 christos Exp $	*/
 
 /*
@@ -3360,7 +3360,7 @@ syn_cache_timer(void *arg)
 	 * than the keep alive timer would allow, expire it.
 	 */
 	sc->sc_rxttot += sc->sc_rxtcur;
-	if (sc->sc_rxttot >= tcptv_keep_init)
+	if (sc->sc_rxttot >= READ_ONCE(tcptv_keep_init))
 		goto dropit;
 
 	/* Advance the timer back-off. */
@@ -3867,7 +3867,8 @@ syn_cache_add(struct sockaddr *src, struct sockaddr *dst, struct tcphdr *th,
 		return (-1);
 	}
 	refcnt_init_trace(&sc->sc_refcnt, DT_REFCNT_IDX_SYNCACHE);
-	timeout_set_proc(&sc->sc_timer, syn_cache_timer, sc);
+	timeout_set_flags(&sc->sc_timer, syn_cache_timer, sc,
+	    KCLOCK_NONE, TIMEOUT_PROC | TIMEOUT_MPSAFE);
 
 	/*
 	 * Fill in the cache, and put the necessary IP and TCP
diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
index f5c88511626..b687d436dc5 100644
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tcp_var.h,v 1.172 2023/11/16 18:27:48 bluhm Exp $	*/
+/*	$OpenBSD: tcp_var.h,v 1.173 2023/11/29 19:19:25 bluhm Exp $	*/
 /*	$NetBSD: tcp_var.h,v 1.17 1996/02/13 23:44:24 christos Exp $	*/
 
 /*
@@ -686,7 +686,7 @@ extern	const struct pr_usrreqs tcp6_usrreqs;
 extern	struct pool tcpcb_pool;
 extern	struct inpcbtable tcbtable;	/* head of queue of active tcpcb's */
 extern	int tcp_do_rfc1323;	/* enabled/disabled? */
-extern	int tcptv_keep_init;	/* time to keep alive the initial SYN packet */
+extern	int tcptv_keep_init;	/* [N] time to keep alive initial SYN packet */
 extern	int tcp_mssdflt;	/* default maximum segment size */
 extern	int tcp_rst_ppslim;	/* maximum outgoing RST packet per second */
 extern	int tcp_ack_on_push;	/* ACK immediately on PUSH */