ipv6: Add a sysctl to control multipath hash fields
A subsequent patch will add a new multipath hash policy where the packet
fields used for multipath hash calculation are determined by user space.
This patch adds a sysctl that allows user space to set these fields.
The packet fields are represented using a bitmask and are common between
IPv4 and IPv6 to allow user space to use the same numbering across both
protocols. For example, to hash based on standard 5-tuple:
# sysctl -w net.ipv6.fib_multipath_hash_fields=0x0037
net.ipv6.fib_multipath_hash_fields = 0x0037
To avoid introducing holes in 'struct netns_sysctl_ipv6', move the
'bindv6only' field after the multipath hash fields.
The kernel rejects unknown fields, for example:
# sysctl -w net.ipv6.fib_multipath_hash_fields=0x1000
sysctl: setting key "net.ipv6.fib_multipath_hash_fields": Invalid argument
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 33d2d6a..2d650dc 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -32,6 +32,7 @@
#include <net/lwtunnel.h>
#include <net/fib_notifier.h>
+#include <net/ip_fib.h>
#include <net/ip6_fib.h>
#include <net/ip6_route.h>
@@ -2355,6 +2356,10 @@ static int __net_init fib6_net_init(struct net *net)
if (err)
return err;
+ /* Default to 3-tuple */
+ net->ipv6.sysctl.multipath_hash_fields =
+ FIB_MULTIPATH_HASH_FIELD_DEFAULT_MASK;
+
spin_lock_init(&net->ipv6.fib6_gc_lock);
rwlock_init(&net->ipv6.fib6_walker_lock);
INIT_LIST_HEAD(&net->ipv6.fib6_walkers);