[src/trunk]: src/sys/net tun(4): Factor out setup/teardown into separate rout...

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/dd3aa666f3f7
branches:  trunk
changeset: 363497:dd3aa666f3f7
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sun Mar 13 21:32:07 2022 +0000

description:
tun(4): Factor out setup/teardown into separate routines.

- Reduce duplication.
- Plug softint leak on recycling tun.

(This recycling business seems kinda sketchy...)

diffstat:

 sys/net/if_tun.c |  86 ++++++++++++++++++++++++++++++++++++++-----------------
 1 files changed, 59 insertions(+), 27 deletions(-)

diffs (133 lines):

diff -r cd41309baa16 -r dd3aa666f3f7 sys/net/if_tun.c
--- a/sys/net/if_tun.c  Sun Mar 13 21:31:58 2022 +0000
+++ b/sys/net/if_tun.c  Sun Mar 13 21:32:07 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_tun.c,v 1.165 2022/03/13 21:31:47 riastradh Exp $   */
+/*     $NetBSD: if_tun.c,v 1.166 2022/03/13 21:32:07 riastradh Exp $   */
 
 /*
  * Copyright (c) 1988, Julian Onions <jpo%cs.nott.ac.uk@localhost>
@@ -19,7 +19,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_tun.c,v 1.165 2022/03/13 21:31:47 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_tun.c,v 1.166 2022/03/13 21:32:07 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -211,29 +211,73 @@
        return tp;
 }
 
+static void
+tun_init(struct tun_softc *tp, int unit)
+{
+
+       tp->tun_unit = unit;
+       mutex_init(&tp->tun_lock, MUTEX_DEFAULT, IPL_NET);
+       cv_init(&tp->tun_cv, "tunread");
+       selinit(&tp->tun_rsel);
+       selinit(&tp->tun_wsel);
+
+       tp->tun_osih = softint_establish(SOFTINT_CLOCK, tun_o_softintr, tp);
+       tp->tun_isih = softint_establish(SOFTINT_CLOCK, tun_i_softintr, tp);
+}
+
+static void
+tun_fini(struct tun_softc *tp)
+{
+
+       softint_disestablish(tp->tun_isih);
+       softint_disestablish(tp->tun_osih);
+
+       seldestroy(&tp->tun_wsel);
+       seldestroy(&tp->tun_rsel);
+       mutex_destroy(&tp->tun_lock);
+       cv_destroy(&tp->tun_cv);
+}
+
+static struct tun_softc *
+tun_alloc(int unit)
+{
+       struct tun_softc *tp;
+
+       tp = kmem_zalloc(sizeof(*tp), KM_SLEEP);
+       tun_init(tp, unit);
+
+       return tp;
+}
+
+static void
+tun_recycle(struct tun_softc *tp)
+{
+
+       memset(&tp->tun_if, 0, sizeof(struct ifnet)); /* XXX ??? */
+}
+
+static void
+tun_free(struct tun_softc *tp)
+{
+
+       tun_fini(tp);
+       kmem_free(tp, sizeof(*tp));
+}
+
 static int
 tun_clone_create(struct if_clone *ifc, int unit)
 {
        struct tun_softc *tp;
 
        if ((tp = tun_find_zunit(unit)) == NULL) {
-               tp = kmem_zalloc(sizeof(*tp), KM_SLEEP);
-
-               tp->tun_unit = unit;
-               mutex_init(&tp->tun_lock, MUTEX_DEFAULT, IPL_NET);
-               cv_init(&tp->tun_cv, "tunread");
-               selinit(&tp->tun_rsel);
-               selinit(&tp->tun_wsel);
+               tp = tun_alloc(unit);
        } else {
-               /* Revive tunnel instance; clear ifp part */
-               (void)memset(&tp->tun_if, 0, sizeof(struct ifnet));
+               tun_recycle(tp);
        }
 
        if_initname(&tp->tun_if, ifc->ifc_name, unit);
        tunattach0(tp);
        tp->tun_flags |= TUN_INITED;
-       tp->tun_osih = softint_establish(SOFTINT_CLOCK, tun_o_softintr, tp);
-       tp->tun_isih = softint_establish(SOFTINT_CLOCK, tun_i_softintr, tp);
 
        mutex_enter(&tun_softc_lock);
        LIST_INSERT_HEAD(&tun_softc_list, tp, tun_list);
@@ -301,13 +345,7 @@
        if_detach(ifp);
 
        if (!zombie) {
-               seldestroy(&tp->tun_rsel);
-               seldestroy(&tp->tun_wsel);
-               softint_disestablish(tp->tun_osih);
-               softint_disestablish(tp->tun_isih);
-               mutex_destroy(&tp->tun_lock);
-               cv_destroy(&tp->tun_cv);
-               kmem_free(tp, sizeof(*tp));
+               tun_free(tp);
        }
 
        return 0;
@@ -367,13 +405,7 @@
 
        if ((tp = tun_find_zunit(minor(dev))) != NULL) {
                /* interface was "destroyed" before the close */
-               seldestroy(&tp->tun_rsel);
-               seldestroy(&tp->tun_wsel);
-               softint_disestablish(tp->tun_osih);
-               softint_disestablish(tp->tun_isih);
-               mutex_destroy(&tp->tun_lock);
-               cv_destroy(&tp->tun_cv);
-               kmem_free(tp, sizeof(*tp));
+               tun_free(tp);
                return 0;
        }