From: David Ahern <dsahern@kernel.org>
To: netdev@vger.kernel.org
Cc: davem@davemloft.net, kuba@kernel.org,
nikolay@cumulusnetworks.com, David Ahern <dsahern@gmail.com>
Subject: [PATCH net 3/5] nexthop: Expand nexthop_is_multipath in a few places
Date: Tue, 26 May 2020 09:01:12 -0600 [thread overview]
Message-ID: <20200526150114.41687-4-dsahern@kernel.org> (raw)
In-Reply-To: <20200526150114.41687-1-dsahern@kernel.org>
From: David Ahern <dsahern@gmail.com>
I got too fancy consolidating checks on multipath type. The result
is that path lookups can access 2 different nh_grp structs as exposed
by Nik's torture tests. Expand nexthop_is_multipath within nexthop.h to
avoid multiple, nh_grp dereferences and make decisions based on the
consistent struct.
Only 2 places left using nexthop_is_multipath are within IPv6, both
only check that the nexthop is a multipath for a branching decision
which are acceptable.
Fixes: 430a049190de ("nexthop: Add support for nexthop groups")
Signed-off-by: David Ahern <dsahern@gmail.com>
---
include/net/nexthop.h | 41 +++++++++++++++++++++++++----------------
1 file changed, 25 insertions(+), 16 deletions(-)
diff --git a/include/net/nexthop.h b/include/net/nexthop.h
index 8a343519ed7a..f09e8d7d9886 100644
--- a/include/net/nexthop.h
+++ b/include/net/nexthop.h
@@ -137,21 +137,20 @@ static inline unsigned int nexthop_num_path(const struct nexthop *nh)
{
unsigned int rc = 1;
- if (nexthop_is_multipath(nh)) {
+ if (nh->is_group) {
struct nh_group *nh_grp;
nh_grp = rcu_dereference_rtnl(nh->nh_grp);
- rc = nh_grp->num_nh;
+ if (nh_grp->mpath)
+ rc = nh_grp->num_nh;
}
return rc;
}
static inline
-struct nexthop *nexthop_mpath_select(const struct nexthop *nh, int nhsel)
+struct nexthop *nexthop_mpath_select(const struct nh_group *nhg, int nhsel)
{
- const struct nh_group *nhg = rcu_dereference_rtnl(nh->nh_grp);
-
/* for_nexthops macros in fib_semantics.c grabs a pointer to
* the nexthop before checking nhsel
*/
@@ -186,12 +185,14 @@ static inline bool nexthop_is_blackhole(const struct nexthop *nh)
{
const struct nh_info *nhi;
- if (nexthop_is_multipath(nh)) {
- if (nexthop_num_path(nh) > 1)
- return false;
- nh = nexthop_mpath_select(nh, 0);
- if (!nh)
+ if (nh->is_group) {
+ struct nh_group *nh_grp;
+
+ nh_grp = rcu_dereference_rtnl(nh->nh_grp);
+ if (nh_grp->num_nh > 1)
return false;
+
+ nh = nh_grp->nh_entries[0].nh;
}
nhi = rcu_dereference_rtnl(nh->nh_info);
@@ -217,10 +218,15 @@ struct fib_nh_common *nexthop_fib_nhc(struct nexthop *nh, int nhsel)
BUILD_BUG_ON(offsetof(struct fib_nh, nh_common) != 0);
BUILD_BUG_ON(offsetof(struct fib6_nh, nh_common) != 0);
- if (nexthop_is_multipath(nh)) {
- nh = nexthop_mpath_select(nh, nhsel);
- if (!nh)
- return NULL;
+ if (nh->is_group) {
+ struct nh_group *nh_grp;
+
+ nh_grp = rcu_dereference_rtnl(nh->nh_grp);
+ if (nh_grp->mpath) {
+ nh = nexthop_mpath_select(nh_grp, nhsel);
+ if (!nh)
+ return NULL;
+ }
}
nhi = rcu_dereference_rtnl(nh->nh_info);
@@ -264,8 +270,11 @@ static inline struct fib6_nh *nexthop_fib6_nh(struct nexthop *nh)
{
struct nh_info *nhi;
- if (nexthop_is_multipath(nh)) {
- nh = nexthop_mpath_select(nh, 0);
+ if (nh->is_group) {
+ struct nh_group *nh_grp;
+
+ nh_grp = rcu_dereference_rtnl(nh->nh_grp);
+ nh = nexthop_mpath_select(nh_grp, 0);
if (!nh)
return NULL;
}
--
2.21.1 (Apple Git-122.3)
next prev parent reply other threads:[~2020-05-26 15:01 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-26 15:01 [PATCH net 0/5] nexthops: Fix 2 fundamental flaws with nexthop groups David Ahern
2020-05-26 15:01 ` [PATCH net 1/5] nexthops: Move code from remove_nexthop_from_groups to remove_nh_grp_entry David Ahern
2020-05-26 15:07 ` Nikolay Aleksandrov
2020-05-26 15:01 ` [PATCH net 2/5] nexthops: don't modify published nexthop groups David Ahern
2020-05-26 15:01 ` David Ahern [this message]
2020-05-26 15:08 ` [PATCH net 3/5] nexthop: Expand nexthop_is_multipath in a few places Nikolay Aleksandrov
2020-05-26 15:01 ` [PATCH net 4/5] ipv4: Refactor nhc evaluation in fib_table_lookup David Ahern
2020-05-26 15:09 ` Nikolay Aleksandrov
2020-05-26 15:01 ` [PATCH net 5/5] ipv4: nexthop version of fib_info_nh_uses_dev David Ahern
2020-05-26 15:10 ` Nikolay Aleksandrov
2020-05-26 18:37 ` Jakub Kicinski
2020-05-26 18:39 ` David Ahern
2020-05-26 22:28 ` [PATCH net 0/5] nexthops: Fix 2 fundamental flaws with nexthop groups David Miller
2020-05-26 22:35 ` Nikolay Aleksandrov
2020-05-26 22:37 ` Nikolay Aleksandrov
2020-05-26 22:39 ` David Ahern
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