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Message-Id: <20171031141054.9954-11-davem@davemloft.net>
Date: Tue, 31 Oct 2017 23:10:53 +0900
From: "David S. Miller" <davem@...emloft.net>
To: netdev@...r.kernel.org
Cc: "David S. Miller" <davem@...emloft.net>
Subject: [RFC v2 PATCH 10/11] xfrm: Stop using dst->next in bundle construction.
While building ipsec bundles, blocks of xfrm dsts are linked together
using dst->next from bottom to the top.
The only thing this is used for is initializing the pmtu values of the
xfrm stack, and for updating the mtu values at xfrm_bundle_ok() time.
The bundle pmtu entries must be processed in this order so that pmtu
values lower in the stack of routes can propagate up to the higher
ones.
Avoid using dst->next by simply maintaining an array of dst pointers
as we already do for the xfrm_state objects when building the bundle.
Signed-off-by: David S. Miller <davem@...emloft.net>
---
net/xfrm/xfrm_policy.c | 56 ++++++++++++++++++++++++++++----------------------
1 file changed, 32 insertions(+), 24 deletions(-)
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 7b80ee7486db..b815884deb16 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -54,7 +54,7 @@ static struct xfrm_policy_afinfo const __rcu *xfrm_policy_afinfo[AF_INET6 + 1]
static struct kmem_cache *xfrm_dst_cache __read_mostly;
static __read_mostly seqcount_t xfrm_policy_hash_generation;
-static void xfrm_init_pmtu(struct dst_entry *dst);
+static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr);
static int stale_bundle(struct dst_entry *dst);
static int xfrm_bundle_ok(struct xfrm_dst *xdst);
static void xfrm_policy_queue_process(struct timer_list *t);
@@ -1537,7 +1537,9 @@ static inline int xfrm_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
*/
static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
- struct xfrm_state **xfrm, int nx,
+ struct xfrm_state **xfrm,
+ struct xfrm_dst **bundle,
+ int nx,
const struct flowi *fl,
struct dst_entry *dst)
{
@@ -1572,6 +1574,7 @@ static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
goto put_states;
}
+ bundle[i] = xdst;
if (!xdst_prev)
xdst0 = xdst;
else
@@ -1615,7 +1618,6 @@ static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
dst1->input = dst_discard;
dst1->output = inner_mode->afinfo->output;
- dst1->next = &xdst_prev->u.dst;
xdst_prev = xdst;
header_len += xfrm[i]->props.header_len;
@@ -1633,7 +1635,7 @@ static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
goto free_dst;
xfrm_init_path(xdst0, dst, nfheader_len);
- xfrm_init_pmtu(&xdst_prev->u.dst);
+ xfrm_init_pmtu(bundle, nx);
for (xdst_prev = xdst0; xdst_prev != (struct xfrm_dst *)dst;
xdst_prev = (struct xfrm_dst *) xfrm_dst_child(&xdst_prev->u.dst)) {
@@ -1807,6 +1809,7 @@ xfrm_resolve_and_create_bundle(struct xfrm_policy **pols, int num_pols,
{
struct net *net = xp_net(pols[0]);
struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
+ struct xfrm_dst *bundle[XFRM_MAX_DEPTH];
struct xfrm_dst *xdst, *old;
struct dst_entry *dst;
int err;
@@ -1832,7 +1835,7 @@ xfrm_resolve_and_create_bundle(struct xfrm_policy **pols, int num_pols,
return ERR_PTR(err);
}
- dst = xfrm_bundle_create(pols[0], xfrm, err, fl, dst_orig);
+ dst = xfrm_bundle_create(pols[0], xfrm, bundle, err, fl, dst_orig);
if (IS_ERR(dst)) {
XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLEGENERROR);
return ERR_CAST(dst);
@@ -2593,12 +2596,14 @@ static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
return dst;
}
-static void xfrm_init_pmtu(struct dst_entry *dst)
+static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr)
{
- do {
- struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
+ while (nr--) {
+ struct xfrm_dst *xdst = bundle[nr];
u32 pmtu, route_mtu_cached;
+ struct dst_entry *dst;
+ dst = &xdst->u.dst;
pmtu = dst_mtu(xfrm_dst_child(dst));
xdst->child_mtu_cached = pmtu;
@@ -2611,7 +2616,7 @@ static void xfrm_init_pmtu(struct dst_entry *dst)
pmtu = route_mtu_cached;
dst_metric_set(dst, RTAX_MTU, pmtu);
- } while ((dst = dst->next));
+ }
}
/* Check that the bundle accepts the flow and its components are
@@ -2620,8 +2625,10 @@ static void xfrm_init_pmtu(struct dst_entry *dst)
static int xfrm_bundle_ok(struct xfrm_dst *first)
{
+ struct xfrm_dst *bundle[XFRM_MAX_DEPTH];
struct dst_entry *dst = &first->u.dst;
- struct xfrm_dst *last;
+ struct xfrm_dst *xdst;
+ int start_from, nr;
u32 mtu;
if (!dst_check(xfrm_dst_path(dst), ((struct xfrm_dst *)dst)->path_cookie) ||
@@ -2631,8 +2638,7 @@ static int xfrm_bundle_ok(struct xfrm_dst *first)
if (dst->flags & DST_XFRM_QUEUE)
return 1;
- last = NULL;
-
+ start_from = nr = 0;
do {
struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
@@ -2644,9 +2650,11 @@ static int xfrm_bundle_ok(struct xfrm_dst *first)
xdst->policy_genid != atomic_read(&xdst->pols[0]->genid))
return 0;
+ bundle[nr++] = xdst;
+
mtu = dst_mtu(xfrm_dst_child(dst));
if (xdst->child_mtu_cached != mtu) {
- last = xdst;
+ start_from = nr;
xdst->child_mtu_cached = mtu;
}
@@ -2654,30 +2662,30 @@ static int xfrm_bundle_ok(struct xfrm_dst *first)
return 0;
mtu = dst_mtu(xdst->route);
if (xdst->route_mtu_cached != mtu) {
- last = xdst;
+ start_from = nr;
xdst->route_mtu_cached = mtu;
}
dst = xfrm_dst_child(dst);
} while (dst->xfrm);
- if (likely(!last))
+ if (likely(!start_from))
return 1;
- mtu = last->child_mtu_cached;
- for (;;) {
- dst = &last->u.dst;
+ xdst = bundle[start_from - 1];
+ mtu = xdst->child_mtu_cached;
+ while (start_from--) {
+ dst = &xdst->u.dst;
mtu = xfrm_state_mtu(dst->xfrm, mtu);
- if (mtu > last->route_mtu_cached)
- mtu = last->route_mtu_cached;
+ if (mtu > xdst->route_mtu_cached)
+ mtu = xdst->route_mtu_cached;
dst_metric_set(dst, RTAX_MTU, mtu);
-
- if (last == first)
+ if (!start_from)
break;
- last = (struct xfrm_dst *)last->u.dst.next;
- last->child_mtu_cached = mtu;
+ xdst = bundle[start_from - 1];
+ xdst->child_mtu_cached = mtu;
}
return 1;
--
2.13.6
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