Use shared netlock in soreceive(). The UDP and IP divert layer

provide locking of the PCB.  If that is possible, use shared instead
of exclusive netlock in soreceive().  The PCB mutex provides a per
socket lock against multiple soreceive() running in parallel.
Release and regrab both locks in sosleep_nsec().
OK mvs@

1 files changed, 21 insertions, 1 deletions

diff --git a/sys/netinet/ip_divert.c b/sys/netinet/ip_divert.c
index 361d00c4ea4..1cdad66c298 100644
--- a/sys/netinet/ip_divert.c
+++ b/sys/netinet/ip_divert.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: ip_divert.c,v 1.86 2022/09/03 22:43:38 mvs Exp $ */
+/*      $OpenBSD: ip_divert.c,v 1.87 2022/09/05 14:56:09 bluhm Exp $ */
 
 /*
  * Copyright (c) 2009 Michele Marchetto <michele@openbsd.org>
@@ -65,6 +65,8 @@ const struct sysctl_bounded_args divertctl_vars[] = {
 const struct pr_usrreqs divert_usrreqs = {
 	.pru_attach	= divert_attach,
 	.pru_detach	= divert_detach,
+	.pru_lock	= divert_lock,
+	.pru_unlock	= divert_unlock,
 	.pru_bind	= divert_bind,
 	.pru_shutdown	= divert_shutdown,
 	.pru_send	= divert_send,
@@ -288,6 +290,24 @@ divert_detach(struct socket *so)
 	return (0);
 }
 
+void
+divert_lock(struct socket *so)
+{
+	struct inpcb *inp = sotoinpcb(so);
+
+	NET_ASSERT_LOCKED();
+	mtx_enter(&inp->inp_mtx);
+}
+
+void
+divert_unlock(struct socket *so)
+{
+	struct inpcb *inp = sotoinpcb(so);
+
+	NET_ASSERT_LOCKED();
+	mtx_leave(&inp->inp_mtx);
+}
+
 int
 divert_bind(struct socket *so, struct mbuf *addr, struct proc *p)
 {