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, 16 insertions, 10 deletions

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index b53ecef89d59..5c8a4d21b8e0 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1469,7 +1469,7 @@ found:
 		}
 		if (fi->fib_flags & RTNH_F_DEAD)
 			continue;
-		for (nhsel = 0; nhsel < fi->fib_nhs; nhsel++) {
+		for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) {
 			struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel);
 
 			if (nhc->nhc_flags & RTNH_F_DEAD)
@@ -2717,14 +2717,18 @@ static void fib_route_seq_stop(struct seq_file *seq, void *v)
 	rcu_read_unlock();
 }
 
-static unsigned int fib_flag_trans(int type, __be32 mask, const struct fib_info *fi)
+static unsigned int fib_flag_trans(int type, __be32 mask, struct fib_info *fi)
 {
 	unsigned int flags = 0;
 
 	if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT)
 		flags = RTF_REJECT;
-	if (fi && fi->fib_nh->fib_nh_gw4)
-		flags |= RTF_GATEWAY;
+	if (fi) {
+		const struct fib_nh *nh = fib_info_nh(fi, 0);
+
+		if (nh->fib_nh_gw4)
+			flags |= RTF_GATEWAY;
+	}
 	if (mask == htonl(0xFFFFFFFF))
 		flags |= RTF_HOST;
 	flags |= RTF_UP;
@@ -2755,7 +2759,7 @@ static int fib_route_seq_show(struct seq_file *seq, void *v)
 	prefix = htonl(l->key);
 
 	hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
-		const struct fib_info *fi = fa->fa_info;
+		struct fib_info *fi = fa->fa_info;
 		__be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen);
 		unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi);
 
@@ -2768,26 +2772,28 @@ static int fib_route_seq_show(struct seq_file *seq, void *v)
 
 		seq_setwidth(seq, 127);
 
-		if (fi)
+		if (fi) {
+			struct fib_nh *nh = fib_info_nh(fi, 0);
+
 			seq_printf(seq,
 				   "%s\t%08X\t%08X\t%04X\t%d\t%u\t"
 				   "%d\t%08X\t%d\t%u\t%u",
-				   fi->fib_dev ? fi->fib_dev->name : "*",
+				   nh->fib_nh_dev ? nh->fib_nh_dev->name : "*",
 				   prefix,
-				   fi->fib_nh->fib_nh_gw4, flags, 0, 0,
+				   nh->fib_nh_gw4, flags, 0, 0,
 				   fi->fib_priority,
 				   mask,
 				   (fi->fib_advmss ?
 				    fi->fib_advmss + 40 : 0),
 				   fi->fib_window,
 				   fi->fib_rtt >> 3);
-		else
+		} else {
 			seq_printf(seq,
 				   "*\t%08X\t%08X\t%04X\t%d\t%u\t"
 				   "%d\t%08X\t%d\t%u\t%u",
 				   prefix, 0, flags, 0, 0, 0,
 				   mask, 0, 0, 0);
-
+		}
 		seq_pad(seq, '\n');
 	}