[PATCH 4.4 18/27] net: ipv4: Fix multipath selection with vrf

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

--

From: David Ahern 


[ Upstream commit 7a18c5b9fb31a999afc62b0e60978aa896fc89e9 ]

fib_select_path does not call fib_select_multipath if oif is set in the
flow struct. For VRF use cases oif is always set, so multipath route
selection is bypassed. Use the FLOWI_FLAG_SKIP_NH_OIF to skip the oif
check similar to what is done in fib_table_lookup.

Add saddr and proto to the flow struct for the fib lookup done by the
VRF driver to better match hash computation for a flow.

Fixes: 613d09b30f8b ("net: Use VRF device index for lookups on TX")
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman 
---
 drivers/net/vrf.c|2 ++
 net/ipv4/fib_semantics.c |9 +++--
 2 files changed, 9 insertions(+), 2 deletions(-)

--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -301,7 +301,9 @@ static netdev_tx_t vrf_process_v4_outbou
.flowi4_tos = RT_TOS(ip4h->tos),
.flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_L3MDEV_SRC |
FLOWI_FLAG_SKIP_NH_OIF,
+   .flowi4_proto = ip4h->protocol,
.daddr = ip4h->daddr,
+   .saddr = ip4h->saddr,
};
 
if (vrf_send_v4_prep(skb, , vrf_dev))
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -1588,8 +1588,13 @@ void fib_select_multipath(struct fib_res
 void fib_select_path(struct net *net, struct fib_result *res,
 struct flowi4 *fl4, int mp_hash)
 {
+   bool oif_check;
+
+   oif_check = (fl4->flowi4_oif == 0 ||
+fl4->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF);
+
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
-   if (res->fi->fib_nhs > 1 && fl4->flowi4_oif == 0) {
+   if (res->fi->fib_nhs > 1 && oif_check) {
if (mp_hash < 0)
mp_hash = get_hash_from_flowi4(fl4) >> 1;
 
@@ -1599,7 +1604,7 @@ void fib_select_path(struct net *net, st
 #endif
if (!res->prefixlen &&
res->table->tb_num_default > 1 &&
-   res->type == RTN_UNICAST && !fl4->flowi4_oif)
+   res->type == RTN_UNICAST && oif_check)
fib_select_default(fl4, res);
 
if (!fl4->saddr)

[PATCH 4.4 18/27] net: ipv4: Fix multipath selection with vrf

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

--

From: David Ahern 


[ Upstream commit 7a18c5b9fb31a999afc62b0e60978aa896fc89e9 ]

fib_select_path does not call fib_select_multipath if oif is set in the
flow struct. For VRF use cases oif is always set, so multipath route
selection is bypassed. Use the FLOWI_FLAG_SKIP_NH_OIF to skip the oif
check similar to what is done in fib_table_lookup.

Add saddr and proto to the flow struct for the fib lookup done by the
VRF driver to better match hash computation for a flow.

Fixes: 613d09b30f8b ("net: Use VRF device index for lookups on TX")
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman 
---
 drivers/net/vrf.c|2 ++
 net/ipv4/fib_semantics.c |9 +++--
 2 files changed, 9 insertions(+), 2 deletions(-)

--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -301,7 +301,9 @@ static netdev_tx_t vrf_process_v4_outbou
.flowi4_tos = RT_TOS(ip4h->tos),
.flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_L3MDEV_SRC |
FLOWI_FLAG_SKIP_NH_OIF,
+   .flowi4_proto = ip4h->protocol,
.daddr = ip4h->daddr,
+   .saddr = ip4h->saddr,
};
 
if (vrf_send_v4_prep(skb, , vrf_dev))
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -1588,8 +1588,13 @@ void fib_select_multipath(struct fib_res
 void fib_select_path(struct net *net, struct fib_result *res,
 struct flowi4 *fl4, int mp_hash)
 {
+   bool oif_check;
+
+   oif_check = (fl4->flowi4_oif == 0 ||
+fl4->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF);
+
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
-   if (res->fi->fib_nhs > 1 && fl4->flowi4_oif == 0) {
+   if (res->fi->fib_nhs > 1 && oif_check) {
if (mp_hash < 0)
mp_hash = get_hash_from_flowi4(fl4) >> 1;
 
@@ -1599,7 +1604,7 @@ void fib_select_path(struct net *net, st
 #endif
if (!res->prefixlen &&
res->table->tb_num_default > 1 &&
-   res->type == RTN_UNICAST && !fl4->flowi4_oif)
+   res->type == RTN_UNICAST && oif_check)
fib_select_default(fl4, res);
 
if (!fl4->saddr)