path: root/net/ipv4/fib_semantics.c
diff options
authorNikolay Aleksandrov <nikolay@cumulusnetworks.com>2017-03-16 15:28:00 +0200
committerDavid S. Miller <davem@davemloft.net>2017-03-21 15:27:19 -0700
commitbf4e0a3db97eb882368fd82980b3b1fa0b5b9778 (patch)
treef1e5a3fd90d22fc603bc5a6780fc1c716684ad94 /net/ipv4/fib_semantics.c
parentnet/8021q: create device with all possible features in wanted_features (diff)
net: ipv4: add support for ECMP hash policy choice
This patch adds support for ECMP hash policy choice via a new sysctl called fib_multipath_hash_policy and also adds support for L4 hashes. The current values for fib_multipath_hash_policy are: 0 - layer 3 (default) 1 - layer 4 If there's an skb hash already set and it matches the chosen policy then it will be used instead of being calculated (currently only for L4). In L3 mode we always calculate the hash due to the ICMP error special case, the flow dissector's field consistentification should handle the address order thus we can remove the address reversals. If the skb is provided we always use it for the hash calculation, otherwise we fallback to fl4, that is if skb is NULL fl4 has to be set. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/fib_semantics.c')
1 files changed, 3 insertions, 8 deletions
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 317026a39cfa..da449ddb8cc1 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -57,7 +57,6 @@ static unsigned int fib_info_cnt;
static struct hlist_head fib_info_devhash[DEVINDEX_HASHSIZE];
-u32 fib_multipath_secret __read_mostly;
#define for_nexthops(fi) { \
int nhsel; const struct fib_nh *nh; \
@@ -576,9 +575,6 @@ static void fib_rebalance(struct fib_info *fi)
atomic_set(&nexthop_nh->nh_upper_bound, upper_bound);
} endfor_nexthops(fi);
- net_get_random_once(&fib_multipath_secret,
- sizeof(fib_multipath_secret));
static inline void fib_add_weight(struct fib_info *fi,
@@ -1641,7 +1637,7 @@ void fib_select_multipath(struct fib_result *res, int hash)
void fib_select_path(struct net *net, struct fib_result *res,
- struct flowi4 *fl4, int mp_hash)
+ struct flowi4 *fl4, const struct sk_buff *skb)
bool oif_check;
@@ -1650,10 +1646,9 @@ void fib_select_path(struct net *net, struct fib_result *res,
if (res->fi->fib_nhs > 1 && oif_check) {
- if (mp_hash < 0)
- mp_hash = get_hash_from_flowi4(fl4) >> 1;
+ int h = fib_multipath_hash(res->fi, fl4, skb);
- fib_select_multipath(res, mp_hash);
+ fib_select_multipath(res, h);