[src/trunk]: src/sys/net l2tp(4) support when hashinit() cannot allocate requ...

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

details:   https://anonhg.NetBSD.org/src/rev/18a8dbaec3c3
branches:  trunk
changeset: 823109:18a8dbaec3c3
user:      knakahara <knakahara%NetBSD.org@localhost>
date:      Thu Apr 13 00:12:10 2017 +0000

description:
l2tp(4) support when hashinit() cannot allocate requried hash size.

pointed out by s-yamaguchi@IIJ

diffstat:

 sys/net/if_l2tp.c |  25 ++++++++++++-------------
 1 files changed, 12 insertions(+), 13 deletions(-)

diffs (104 lines):

diff -r 41361ed09c15 -r 18a8dbaec3c3 sys/net/if_l2tp.c
--- a/sys/net/if_l2tp.c Wed Apr 12 23:35:29 2017 +0000
+++ b/sys/net/if_l2tp.c Thu Apr 13 00:12:10 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_l2tp.c,v 1.8 2017/04/04 23:49:17 knakahara Exp $    */
+/*     $NetBSD: if_l2tp.c,v 1.9 2017/04/13 00:12:10 knakahara Exp $    */
 
 /*
  * Copyright (c) 2017 Internet Initiative Japan Inc.
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_l2tp.c,v 1.8 2017/04/04 23:49:17 knakahara Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_l2tp.c,v 1.9 2017/04/13 00:12:10 knakahara Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -110,6 +110,7 @@
 static struct {
        kmutex_t lock;
        struct pslist_head *lists;
+       u_long mask;
 } l2tp_hash __cacheline_aligned = {
        .lists = NULL,
 };
@@ -140,7 +141,7 @@
                    struct sockaddr *);
 static void    l2tp_delete_tunnel(struct ifnet *);
 
-static int     id_hash_func(uint32_t);
+static int     id_hash_func(uint32_t, u_long);
 
 static void    l2tp_variant_update(struct l2tp_softc *, struct l2tp_variant *);
 static int     l2tp_set_session(struct l2tp_softc *, uint32_t, uint32_t);
@@ -1002,24 +1003,22 @@
 }
 
 static int
-id_hash_func(uint32_t id)
+id_hash_func(uint32_t id, u_long mask)
 {
        uint32_t hash;
 
        hash = (id >> 16) ^ id;
        hash = (hash >> 4) ^ hash;
 
-       return hash & (L2TP_ID_HASH_SIZE - 1);
+       return hash & mask;
 }
 
 static void
 l2tp_hash_init(void)
 {
-       u_long mask;
 
        l2tp_hash.lists = hashinit(L2TP_ID_HASH_SIZE, HASH_PSLIST, true,
-           &mask);
-       KASSERT(mask == (L2TP_ID_HASH_SIZE - 1));
+           &l2tp_hash.mask);
 }
 
 static int
@@ -1029,19 +1028,19 @@
 
        mutex_enter(&l2tp_hash.lock);
 
-       for (i = 0; i < L2TP_ID_HASH_SIZE; i++) {
+       for (i = 0; i < l2tp_hash.mask + 1; i++) {
                if (PSLIST_WRITER_FIRST(&l2tp_hash.lists[i], struct l2tp_softc,
                        l2tp_hash) != NULL) {
                        mutex_exit(&l2tp_hash.lock);
                        return EBUSY;
                }
        }
-       for (i = 0; i < L2TP_ID_HASH_SIZE; i++)
+       for (i = 0; i < l2tp_hash.mask + 1; i++)
                PSLIST_DESTROY(&l2tp_hash.lists[i]);
 
        mutex_exit(&l2tp_hash.lock);
 
-       hashdone(l2tp_hash.lists, HASH_PSLIST, L2TP_ID_HASH_SIZE - 1);
+       hashdone(l2tp_hash.lists, HASH_PSLIST, l2tp_hash.mask);
 
        return 0;
 }
@@ -1075,7 +1074,7 @@
        l2tp_variant_update(sc, nvar);
        mutex_exit(&sc->l2tp_lock);
 
-       idx = id_hash_func(nvar->lv_my_sess_id);
+       idx = id_hash_func(nvar->lv_my_sess_id, l2tp_hash.mask);
        if ((ifp->if_flags & IFF_DEBUG) != 0)
                log(LOG_DEBUG, "%s: add hash entry: sess_id=%" PRIu32 ", idx=%" PRIu32 "\n",
                    sc->l2tp_ec.ec_if.if_xname, nvar->lv_my_sess_id, idx);
@@ -1124,7 +1123,7 @@
        int s;
        struct l2tp_softc *sc;
 
-       idx = id_hash_func(id);
+       idx = id_hash_func(id, l2tp_hash.mask);
 
        s = pserialize_read_enter();
        PSLIST_READER_FOREACH(sc, &l2tp_hash.lists[idx], struct l2tp_softc,