From 53c2e285f9703001e1bb48d04696c5f9d8f3aef7 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Thu, 13 Nov 2014 17:09:49 +0800 Subject: [PATCH] xfrm: Do not hash socket policies Back in 2003 when I added policy expiration, I half-heartedly did a clean-up and renamed xfrm_sk_policy_link/xfrm_sk_policy_unlink to __xfrm_policy_link/__xfrm_policy_unlink, because the latter could be reused for all policies. I never actually got around to using __xfrm_policy_link for non-socket policies. Later on hashing was added to all xfrm policies, including socket policies. In fact, we don't need hashing on socket policies at all since they're always looked up via a linked list. This patch restores xfrm_sk_policy_link/xfrm_sk_policy_unlink as wrappers around __xfrm_policy_link/__xfrm_policy_unlink so that it's obvious we're dealing with socket policies. This patch also removes hashing from __xfrm_policy_link as for now it's only used by socket policies which do not need to be hashed. Ironically this will in fact allow us to use this helper for non-socket policies which I shall do later. Signed-off-by: Herbert Xu Signed-off-by: Steffen Klassert --- include/net/netns/xfrm.h | 4 ++-- net/xfrm/xfrm_policy.c | 44 ++++++++++++++++++++++++---------------- 2 files changed, 28 insertions(+), 20 deletions(-) diff --git a/include/net/netns/xfrm.h b/include/net/netns/xfrm.h index 9da798256f0e..730d82ad6ee5 100644 --- a/include/net/netns/xfrm.h +++ b/include/net/netns/xfrm.h @@ -50,8 +50,8 @@ struct netns_xfrm { struct list_head policy_all; struct hlist_head *policy_byidx; unsigned int policy_idx_hmask; - struct hlist_head policy_inexact[XFRM_POLICY_MAX * 2]; - struct xfrm_policy_hash policy_bydst[XFRM_POLICY_MAX * 2]; + struct hlist_head policy_inexact[XFRM_POLICY_MAX]; + struct xfrm_policy_hash policy_bydst[XFRM_POLICY_MAX]; unsigned int policy_count[XFRM_POLICY_MAX * 2]; struct work_struct policy_hash_work; struct xfrm_policy_hthresh policy_hthresh; diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index dc653249e845..f4d3a125e49c 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -561,7 +561,7 @@ static void xfrm_hash_resize(struct work_struct *work) mutex_lock(&hash_resize_mutex); total = 0; - for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) { + for (dir = 0; dir < XFRM_POLICY_MAX; dir++) { if (xfrm_bydst_should_resize(net, dir, &total)) xfrm_bydst_resize(net, dir); } @@ -601,7 +601,7 @@ static void xfrm_hash_rebuild(struct work_struct *work) write_lock_bh(&net->xfrm.xfrm_policy_lock); /* reset the bydst and inexact table in all directions */ - for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) { + for (dir = 0; dir < XFRM_POLICY_MAX; dir++) { INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]); hmask = net->xfrm.policy_bydst[dir].hmask; odst = net->xfrm.policy_bydst[dir].table; @@ -1247,17 +1247,10 @@ out: static void __xfrm_policy_link(struct xfrm_policy *pol, int dir) { struct net *net = xp_net(pol); - struct hlist_head *chain = policy_hash_bysel(net, &pol->selector, - pol->family, dir); list_add(&pol->walk.all, &net->xfrm.policy_all); - hlist_add_head(&pol->bydst, chain); - hlist_add_head(&pol->byidx, net->xfrm.policy_byidx+idx_hash(net, pol->index)); net->xfrm.policy_count[dir]++; xfrm_pol_hold(pol); - - if (xfrm_bydst_should_resize(net, dir, NULL)) - schedule_work(&net->xfrm.policy_hash_work); } static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol, @@ -1265,17 +1258,31 @@ static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol, { struct net *net = xp_net(pol); - if (hlist_unhashed(&pol->bydst)) + if (list_empty(&pol->walk.all)) return NULL; - hlist_del_init(&pol->bydst); - hlist_del(&pol->byidx); - list_del(&pol->walk.all); + /* Socket policies are not hashed. */ + if (!hlist_unhashed(&pol->bydst)) { + hlist_del(&pol->bydst); + hlist_del(&pol->byidx); + } + + list_del_init(&pol->walk.all); net->xfrm.policy_count[dir]--; return pol; } +static void xfrm_sk_policy_link(struct xfrm_policy *pol, int dir) +{ + __xfrm_policy_link(pol, XFRM_POLICY_MAX + dir); +} + +static void xfrm_sk_policy_unlink(struct xfrm_policy *pol, int dir) +{ + __xfrm_policy_unlink(pol, XFRM_POLICY_MAX + dir); +} + int xfrm_policy_delete(struct xfrm_policy *pol, int dir) { struct net *net = xp_net(pol); @@ -1307,7 +1314,7 @@ int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol) if (pol) { pol->curlft.add_time = get_seconds(); pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir, 0); - __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir); + xfrm_sk_policy_link(pol, dir); } if (old_pol) { if (pol) @@ -1316,7 +1323,7 @@ int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol) /* Unlinking succeeds always. This is the only function * allowed to delete or replace socket policy. */ - __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir); + xfrm_sk_policy_unlink(old_pol, dir); } write_unlock_bh(&net->xfrm.xfrm_policy_lock); @@ -1349,7 +1356,7 @@ static struct xfrm_policy *clone_policy(const struct xfrm_policy *old, int dir) memcpy(newp->xfrm_vec, old->xfrm_vec, newp->xfrm_nr*sizeof(struct xfrm_tmpl)); write_lock_bh(&net->xfrm.xfrm_policy_lock); - __xfrm_policy_link(newp, XFRM_POLICY_MAX+dir); + xfrm_sk_policy_link(newp, dir); write_unlock_bh(&net->xfrm.xfrm_policy_lock); xfrm_pol_put(newp); } @@ -2965,10 +2972,11 @@ static int __net_init xfrm_policy_init(struct net *net) goto out_byidx; net->xfrm.policy_idx_hmask = hmask; - for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) { + for (dir = 0; dir < XFRM_POLICY_MAX; dir++) { struct xfrm_policy_hash *htab; net->xfrm.policy_count[dir] = 0; + net->xfrm.policy_count[XFRM_POLICY_MAX + dir] = 0; INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]); htab = &net->xfrm.policy_bydst[dir]; @@ -3020,7 +3028,7 @@ static void xfrm_policy_fini(struct net *net) WARN_ON(!list_empty(&net->xfrm.policy_all)); - for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) { + for (dir = 0; dir < XFRM_POLICY_MAX; dir++) { struct xfrm_policy_hash *htab; WARN_ON(!hlist_empty(&net->xfrm.policy_inexact[dir])); -- 2.39.5