git: c2c8e360d8c0 - main - tcp: virtualise net.inet.tcp.msl sysctl.

The branch main has been updated by melifaro:

URL: https://cgit.FreeBSD.org/src/commit/?id=c2c8e360d8c0b8712158d334686d88f052aef819

commit c2c8e360d8c0b8712158d334686d88f052aef819
Author:     Alexander V. Chernikov <melifaro@FreeBSD.org>
AuthorDate: 2021-12-04 22:02:44 +0000
Commit:     Alexander V. Chernikov <melifaro@FreeBSD.org>
CommitDate: 2021-12-26 14:56:04 +0000

    tcp: virtualise net.inet.tcp.msl sysctl.
    
    VNET teardown waits 2*MSL (60 seconds by default) before expiring
     tcp PCBs. These PCBs holds references to nexthops, which, in turn,
     reference ifnets. This chain results in VNET interfaces being destroyed
     and moved to default VNET only after 60 seconds.
    Allow tcp_msl to be set in jail by virtualising net.inet.tcp.msl sysctl,
     permitting more predictable VNET tests outcomes.
    
    MFC after:      1 week
    Reviewed by:    glebius
    Differential Revision: https://reviews.freebsd.org/D33270
---
 sys/netinet/tcp_subr.c     | 5 +++--
 sys/netinet/tcp_timer.c    | 6 +++---
 sys/netinet/tcp_timer.h    | 3 ++-
 sys/netinet/tcp_timewait.c | 2 +-
 4 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c
index 232163fe9fe5..18de53294229 100644
--- a/sys/netinet/tcp_subr.c
+++ b/sys/netinet/tcp_subr.c
@@ -1506,19 +1506,20 @@ tcp_init(void)
 	COUNTER_ARRAY_ALLOC(V_tcps_states, TCP_NSTATES, M_WAITOK);
 	VNET_PCPUSTAT_ALLOC(tcpstat, M_WAITOK);
 
+	V_tcp_msl = TCPTV_MSL;
+
 	/* Skip initialization of globals for non-default instances. */
 	if (!IS_DEFAULT_VNET(curvnet))
 		return;
 
 	tcp_reass_global_init();
 
-	/* XXX virtualize those bellow? */
+	/* XXX virtualize those below? */
 	tcp_delacktime = TCPTV_DELACK;
 	tcp_keepinit = TCPTV_KEEP_INIT;
 	tcp_keepidle = TCPTV_KEEP_IDLE;
 	tcp_keepintvl = TCPTV_KEEPINTVL;
 	tcp_maxpersistidle = TCPTV_KEEP_IDLE;
-	tcp_msl = TCPTV_MSL;
 	tcp_rexmit_initial = TCPTV_RTOBASE;
 	if (tcp_rexmit_initial < 1)
 		tcp_rexmit_initial = 1;
diff --git a/sys/netinet/tcp_timer.c b/sys/netinet/tcp_timer.c
index 67e550b83bce..54ac67867fcb 100644
--- a/sys/netinet/tcp_timer.c
+++ b/sys/netinet/tcp_timer.c
@@ -117,10 +117,10 @@ SYSCTL_PROC(_net_inet_tcp, TCPCTL_DELACKTIME, delacktime,
     &tcp_delacktime, 0, sysctl_msec_to_ticks, "I",
     "Time before a delayed ACK is sent");
 
-int	tcp_msl;
+VNET_DEFINE(int, tcp_msl);
 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, msl,
-    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
-    &tcp_msl, 0, sysctl_msec_to_ticks, "I",
+    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_VNET,
+    &VNET_NAME(tcp_msl), 0, sysctl_msec_to_ticks, "I",
     "Maximum segment lifetime");
 
 int	tcp_rexmit_initial;
diff --git a/sys/netinet/tcp_timer.h b/sys/netinet/tcp_timer.h
index c5317d1a4155..c0382d68c13c 100644
--- a/sys/netinet/tcp_timer.h
+++ b/sys/netinet/tcp_timer.h
@@ -195,7 +195,6 @@ extern int tcp_maxpersistidle;
 extern int tcp_rexmit_initial;
 extern int tcp_rexmit_min;
 extern int tcp_rexmit_slop;
-extern int tcp_msl;
 extern int tcp_ttl;			/* time to live for TCP segs */
 extern int tcp_backoff[];
 extern int tcp_totbackoff;
@@ -212,6 +211,8 @@ VNET_DECLARE(int, tcp_pmtud_blackhole_mss);
 #define	V_tcp_pmtud_blackhole_mss	VNET(tcp_pmtud_blackhole_mss)
 VNET_DECLARE(int, tcp_v6pmtud_blackhole_mss);
 #define V_tcp_v6pmtud_blackhole_mss	VNET(tcp_v6pmtud_blackhole_mss)
+VNET_DECLARE(int, tcp_msl);
+#define V_tcp_msl			VNET(tcp_msl)
 
 void tcp_inpinfo_lock_del(struct inpcb *inp, struct tcpcb *tp);
 
diff --git a/sys/netinet/tcp_timewait.c b/sys/netinet/tcp_timewait.c
index 52f8002d8505..32b2e72c3484 100644
--- a/sys/netinet/tcp_timewait.c
+++ b/sys/netinet/tcp_timewait.c
@@ -765,7 +765,7 @@ tcp_tw_2msl_reset(struct tcptw *tw, int rearm)
 	TW_WLOCK(V_tw_lock);
 	if (rearm)
 		TAILQ_REMOVE(&V_twq_2msl, tw, tw_2msl);
-	tw->tw_time = ticks + 2 * tcp_msl;
+	tw->tw_time = ticks + 2 * V_tcp_msl;
 	TAILQ_INSERT_TAIL(&V_twq_2msl, tw, tw_2msl);
 	TW_WUNLOCK(V_tw_lock);
 }