datapath: Convert odp_flow_key to use Netlink attributes instead.

One of the goals for Open vSwitch is to decouple kernel and userspace
software, so that either one can be upgraded or rolled back independent of
the other.  To do this in full generality, it must be possible to change
the kernel's idea of the flow key separately from the userspace version.
In turn, that means that flow keys must become variable-length.  This
commit makes that change using Netlink attribute sequences.

This commit does not actually make userspace flexible enough to handle
changes in the kernel flow key structure, because userspace doesn't yet
have enough information to do that intelligently.  Upcoming commits will
fix that.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>

1 files changed, 26 insertions, 3 deletions

diff --git a/datapath/flow.h b/datapath/flow.h
index 07644827..f09f76c4 100644
--- a/datapath/flow.h
+++ b/datapath/flow.h
@@ -29,11 +29,26 @@ struct sw_flow_actions {
 	struct nlattr actions[];
 };
 
+struct sw_flow_key {
+	__be64	tun_id;     /* Encapsulating tunnel ID. */
+	__be32	nw_src;	    /* IP source address. */
+	__be32	nw_dst;	    /* IP destination address. */
+	u16	in_port;    /* Input switch port. */
+	__be16	dl_tci;	    /* 0 if no VLAN, VLAN_TAG_PRESENT set otherwise. */
+	__be16	dl_type;    /* Ethernet frame type. */
+	__be16	tp_src;	    /* TCP/UDP source port. */
+	__be16	tp_dst;	    /* TCP/UDP destination port. */
+	u8	dl_src[ETH_ALEN]; /* Ethernet source address. */
+	u8	dl_dst[ETH_ALEN]; /* Ethernet destination address. */
+	u8	nw_proto;   /* IP protocol or lower 8 bits of ARP opcode. */
+	u8	nw_tos;	    /* IP ToS (DSCP field, 6 bits). */
+};
+
 struct sw_flow {
 	struct rcu_head rcu;
 	struct tbl_node tbl_node;
 
-	struct odp_flow_key key;
+	struct sw_flow_key key;
 	struct sw_flow_actions __rcu *sf_acts;
 
 	atomic_t refcnt;
@@ -74,12 +89,20 @@ void flow_deferred_free_acts(struct sw_flow_actions *);
 void flow_hold(struct sw_flow *);
 void flow_put(struct sw_flow *);
 
-int flow_extract(struct sk_buff *, u16 in_port, struct odp_flow_key *, bool *is_frag);
+int flow_extract(struct sk_buff *, u16 in_port, struct sw_flow_key *, bool *is_frag);
 void flow_used(struct sw_flow *, struct sk_buff *);
 
-u32 flow_hash(const struct odp_flow_key *key);
+u32 flow_hash(const struct sw_flow_key *);
 int flow_cmp(const struct tbl_node *, void *target);
 
+/* By my calculations currently the longest valid nlattr-formatted flow key is
+ * 80 bytes long, so this leaves some safety margin.
+ */
+#define FLOW_BUFSIZE 96
+
+int flow_copy_from_user(struct sw_flow_key *, const struct nlattr __user *ukey, u32 key_len);
+int flow_copy_to_user(struct nlattr __user *ukey, const struct sw_flow_key *, u32 key_len);
+
 static inline struct sw_flow *flow_cast(const struct tbl_node *node)
 {
 	return container_of(node, struct sw_flow, tbl_node);