net/ipv6: move metrics from dst to rt6_info

Similar to IPv4, add fib metrics to the fib struct, which at the moment
is rt6_info. Will be moved to fib6_info in a later patch. Copy metrics
into dst by reference using refcount.

To make the transition:
- add dst_metrics to rt6_info. Default to dst_default_metrics if no
  metrics are passed during route add. No need for a separate pmtu
  entry; it can reference the MTU slot in fib6_metrics

- ip6_convert_metrics allocates memory in the FIB entry and uses
  ip_metrics_convert to copy from netlink attribute to metrics entry

- the convert metrics call is done in ip6_route_info_create simplifying
  the route add path
  + fib6_commit_metrics and fib6_copy_metrics and the temporary
    mx6_config are no longer needed

- add fib6_metric_set helper to change the value of a metric in the
  fib entry since dst_metric_set can no longer be used

- cow_metrics for IPv6 can drop to dst_cow_metrics_generic

- rt6_dst_from_metrics_check is no longer needed

- rt6_fill_node needs the FIB entry and dst as separate arguments to
  keep compatibility with existing output. Current dst address is
  renamed to dest.
  (to be consistent with IPv4 rt6_fill_node really should be split
  into 2 functions similar to fib_dump_info and rt_fill_info)

- rt6_fill_node no longer needs the temporary metrics variable

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 8 deletions

diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index f0a88370ba95..1f8dc9d12abb 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -94,11 +94,6 @@ struct fib6_gc_args {
 #define FIB6_SUBTREE(fn)	(rcu_dereference_protected((fn)->subtree, 1))
 #endif
 
-struct mx6_config {
-	const u32 *mx;
-	DECLARE_BITMAP(mx_valid, RTAX_MAX);
-};
-
 /*
  *	routing information
  *
@@ -176,7 +171,6 @@ struct rt6_info {
 	struct rt6_exception_bucket __rcu *rt6i_exception_bucket;
 
 	u32				rt6i_metric;
-	u32				rt6i_pmtu;
 	/* more non-fragment space at head required */
 	unsigned short			rt6i_nfheader_len;
 	u8				rt6i_protocol;
@@ -185,6 +179,8 @@ struct rt6_info {
 					should_flush:1,
 					unused:6;
 
+	struct dst_metrics		*fib6_metrics;
+#define fib6_pmtu		fib6_metrics->metrics[RTAX_MTU-1]
 	struct fib6_nh			fib6_nh;
 };
 
@@ -390,8 +386,7 @@ void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),
 		    void *arg);
 
 int fib6_add(struct fib6_node *root, struct rt6_info *rt,
-	     struct nl_info *info, struct mx6_config *mxc,
-	     struct netlink_ext_ack *extack);
+	     struct nl_info *info, struct netlink_ext_ack *extack);
 int fib6_del(struct rt6_info *rt, struct nl_info *info);
 
 void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info,
@@ -420,6 +415,12 @@ int fib6_tables_dump(struct net *net, struct notifier_block *nb);
 void fib6_update_sernum(struct net *net, struct rt6_info *rt);
 void fib6_update_sernum_upto_root(struct net *net, struct rt6_info *rt);
 
+void fib6_metric_set(struct rt6_info *f6i, int metric, u32 val);
+static inline bool fib6_metric_locked(struct rt6_info *f6i, int metric)
+{
+	return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric));
+}
+
 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 int fib6_rules_init(void);
 void fib6_rules_cleanup(void);