ipv4: 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.ipv4.fib_multipath_hash_fields=0x0037
net.ipv4.fib_multipath_hash_fields = 0x0037
The kernel rejects unknown fields, for example:
# sysctl -w net.ipv4.fib_multipath_hash_fields=0x1000
sysctl: setting key "net.ipv4.fib_multipath_hash_fields": Invalid argument
More fields can be added in the future, if needed.
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/include/net/ip_fib.h b/include/net/ip_fib.h
index a914f33..3ab2563 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -466,6 +466,49 @@ int fib_sync_up(struct net_device *dev, unsigned char nh_flags);
void fib_sync_mtu(struct net_device *dev, u32 orig_mtu);
void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig);
+/* Fields used for sysctl_fib_multipath_hash_fields.
+ * Common to IPv4 and IPv6.
+ *
+ * Add new fields at the end. This is user API.
+ */
+#define FIB_MULTIPATH_HASH_FIELD_SRC_IP BIT(0)
+#define FIB_MULTIPATH_HASH_FIELD_DST_IP BIT(1)
+#define FIB_MULTIPATH_HASH_FIELD_IP_PROTO BIT(2)
+#define FIB_MULTIPATH_HASH_FIELD_FLOWLABEL BIT(3)
+#define FIB_MULTIPATH_HASH_FIELD_SRC_PORT BIT(4)
+#define FIB_MULTIPATH_HASH_FIELD_DST_PORT BIT(5)
+#define FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP BIT(6)
+#define FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP BIT(7)
+#define FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO BIT(8)
+#define FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL BIT(9)
+#define FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT BIT(10)
+#define FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT BIT(11)
+
+#define FIB_MULTIPATH_HASH_FIELD_OUTER_MASK \
+ (FIB_MULTIPATH_HASH_FIELD_SRC_IP | \
+ FIB_MULTIPATH_HASH_FIELD_DST_IP | \
+ FIB_MULTIPATH_HASH_FIELD_IP_PROTO | \
+ FIB_MULTIPATH_HASH_FIELD_FLOWLABEL | \
+ FIB_MULTIPATH_HASH_FIELD_SRC_PORT | \
+ FIB_MULTIPATH_HASH_FIELD_DST_PORT)
+
+#define FIB_MULTIPATH_HASH_FIELD_INNER_MASK \
+ (FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP | \
+ FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP | \
+ FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO | \
+ FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL | \
+ FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT | \
+ FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT)
+
+#define FIB_MULTIPATH_HASH_FIELD_ALL_MASK \
+ (FIB_MULTIPATH_HASH_FIELD_OUTER_MASK | \
+ FIB_MULTIPATH_HASH_FIELD_INNER_MASK)
+
+#define FIB_MULTIPATH_HASH_FIELD_DEFAULT_MASK \
+ (FIB_MULTIPATH_HASH_FIELD_SRC_IP | \
+ FIB_MULTIPATH_HASH_FIELD_DST_IP | \
+ FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
+
#ifdef CONFIG_IP_ROUTE_MULTIPATH
int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
const struct sk_buff *skb, struct flow_keys *flkeys);
diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index f6af8d9..746c80c 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -210,6 +210,7 @@ struct netns_ipv4 {
#endif
#endif
#ifdef CONFIG_IP_ROUTE_MULTIPATH
+ u32 sysctl_fib_multipath_hash_fields;
u8 sysctl_fib_multipath_use_neigh;
u8 sysctl_fib_multipath_hash_policy;
#endif