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>

1 files changed, 7 insertions, 4 deletions

diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index c7cdb8d0d164..a4691360b395 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -43,6 +43,7 @@
 #include <net/sock.h>
 #include <net/arp.h>
 #include <net/ip_fib.h>
+#include <net/nexthop.h>
 #include <net/rtnetlink.h>
 #include <net/xfrm.h>
 #include <net/l3mdev.h>
@@ -234,7 +235,9 @@ static inline unsigned int __inet_dev_addr_type(struct net *net,
 	if (table) {
 		ret = RTN_UNICAST;
 		if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) {
-			if (!dev || dev == res.fi->fib_dev)
+			struct fib_nh *nh = fib_info_nh(res.fi, 0);
+
+			if (!dev || dev == nh->fib_nh_dev)
 				ret = res.type;
 		}
 	}
@@ -321,8 +324,8 @@ bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev)
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 	int ret;
 
-	for (ret = 0; ret < fi->fib_nhs; ret++) {
-		struct fib_nh *nh = &fi->fib_nh[ret];
+	for (ret = 0; ret < fib_info_num_path(fi); ret++) {
+		const struct fib_nh *nh = fib_info_nh(fi, ret);
 
 		if (nh->fib_nh_dev == dev) {
 			dev_match = true;
@@ -333,7 +336,7 @@ bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev)
 		}
 	}
 #else
-	if (fi->fib_nh[0].fib_nh_dev == dev)
+	if (fib_info_nh(fi, 0)->fib_nh_dev == dev)
 		dev_match = true;
 #endif