ipv4: Use accessors for fib_info nexthop data

Use helpers to access fib_nh and fib_nhs fields of a fib_info. Drop the
fib_dev macro which is an alias for the first nexthop. Replacements:

  fi->fib_dev    --> fib_info_nh(fi, 0)->fib_nh_dev
  fi->fib_nh     --> fib_info_nh(fi, 0)
  fi->fib_nh[i]  --> fib_info_nh(fi, i)
  fi->fib_nhs    --> fib_info_num_path(fi)

where fib_info_nh(fi, i) returns fi->fib_nh[nhsel] and fib_info_num_path
returns fi->fib_nhs.

Move the existing fib_info_nhc to nexthop.h and define the new ones
there. A later patch adds a check if a fib_info uses a nexthop object,
and defining the helpers in nexthop.h avoid circular header
dependencies.

After this all remaining open coded references to fi->fib_nhs and
fi->fib_nh are in:
- fib_create_info and helpers used to lookup an existing fib_info
  entry, and
- the netdev event functions fib_sync_down_dev and fib_sync_up.

The latter two will not be reused for nexthops, and the fib_create_info
will be updated to handle a nexthop in a fib_info.

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

2 files changed, 15 insertions, 6 deletions

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 70ba0302c8c9..42b1a806f6f5 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -153,7 +153,6 @@ struct fib_info {
 	bool			nh_updated;
 	struct rcu_head		rcu;
 	struct fib_nh		fib_nh[0];
-#define fib_dev		fib_nh[0].fib_nh_dev
 };
 
 
@@ -190,11 +189,6 @@ struct fib_result_nl {
 	int             err;
 };
 
-static inline struct fib_nh_common *fib_info_nhc(struct fib_info *fi, int nhsel)
-{
-	return &fi->fib_nh[nhsel].nh_common;
-}
-
 #ifdef CONFIG_IP_MULTIPLE_TABLES
 #define FIB_TABLE_HASHSZ 256
 #else
diff --git a/include/net/nexthop.h b/include/net/nexthop.h
index 6e1b8f53624c..e501d77b82c8 100644
--- a/include/net/nexthop.h
+++ b/include/net/nexthop.h
@@ -192,4 +192,19 @@ static inline bool nexthop_is_blackhole(const struct nexthop *nh)
 	nhi = rcu_dereference_rtnl(nh->nh_info);
 	return nhi->reject_nh;
 }
+
+static inline unsigned int fib_info_num_path(const struct fib_info *fi)
+{
+	return fi->fib_nhs;
+}
+
+static inline struct fib_nh_common *fib_info_nhc(struct fib_info *fi, int nhsel)
+{
+	return &fi->fib_nh[nhsel].nh_common;
+}
+
+static inline struct fib_nh *fib_info_nh(struct fib_info *fi, int nhsel)
+{
+	return &fi->fib_nh[nhsel];
+}
 #endif