[IPV4]: Do fib_alias lookup walk directly in fib_semantic_match().

Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/fib_hash.c

@@ -256,33 +256,15 @@ fn_hash_lookup(struct fib_table *tb, const struct flowi *flp, struct fib_result
 
 		head = &fz->fz_hash[fn_hash(k, fz)];
 		hlist_for_each_entry(f, node, head, fn_hash) {
-			struct fib_alias *fa;
-
 			if (f->fn_key != k)
 				continue;
 
-			list_for_each_entry(fa, &f->fn_alias, fa_list) {
-				if (fa->fa_tos &&
-				    fa->fa_tos != flp->fl4_tos)
-					continue;
-				if (fa->fa_scope < flp->fl4_scope)
-					continue;
-
-				fa->fa_state |= FA_S_ACCESSED;
-
-				err = fib_semantic_match(fa->fa_type,
-							 fa->fa_info,
-							 flp, res);
-				if (err == 0) {
-					res->type = fa->fa_type;
-					res->scope = fa->fa_scope;
-					res->prefixlen = fz->fz_order;
+			err = fib_semantic_match(&f->fn_alias,
+						 flp, res,
+						 fz->fz_order);
+			if (err <= 0)
 				goto out;
 		}
-				if (err < 0)
-					goto out;
-			}
-		}
 	}
 	err = 1;
 out:

net/ipv4/fib_lookup.h

@@ -17,8 +17,9 @@ struct fib_alias {
 #define FA_S_ACCESSED	0x01
 
 /* Exported by fib_semantics.c */
-extern int fib_semantic_match(int type, struct fib_info *,
-			      const struct flowi *, struct fib_result *);
+extern int fib_semantic_match(struct list_head *head,
+			      const struct flowi *flp,
+			      struct fib_result *res, int prefixlen);
 extern void fib_release_info(struct fib_info *);
 extern struct fib_info *fib_create_info(const struct rtmsg *r,
 					struct kern_rta *rta,

net/ipv4/fib_semantics.c

@@ -760,18 +760,32 @@ fib_create_info(const struct rtmsg *r, struct kern_rta *rta,
 	return NULL;
 }
 
-int 
-fib_semantic_match(int type, struct fib_info *fi, const struct flowi *flp, struct fib_result *res)
+int fib_semantic_match(struct list_head *head, const struct flowi *flp,
+		       struct fib_result *res, int prefixlen)
 {
-	int err = fib_props[type].error;
+	struct fib_alias *fa;
+	int nh_sel = 0;
+
+	list_for_each_entry(fa, head, fa_list) {
+		int err;
+
+		if (fa->fa_tos &&
+		    fa->fa_tos != flp->fl4_tos)
+			continue;
+
+		if (fa->fa_scope < flp->fl4_scope)
+			continue;
+
+		fa->fa_state |= FA_S_ACCESSED;
 
+		err = fib_props[fa->fa_type].error;
 		if (err == 0) {
-		if (fi->fib_flags&RTNH_F_DEAD)
-			return 1;
+			struct fib_info *fi = fa->fa_info;
 
-		res->fi = fi;
+			if (fi->fib_flags & RTNH_F_DEAD)
+				continue;
 
-		switch (type) {
+			switch (fa->fa_type) {
 			case RTN_UNICAST:
 			case RTN_LOCAL:
 			case RTN_BROADCAST:
@@ -785,26 +799,34 @@ fib_semantic_match(int type, struct fib_info *fi, const struct flowi *flp, struc
 				}
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 				if (nhsel < fi->fib_nhs) {
-				res->nh_sel = nhsel;
-				atomic_inc(&fi->fib_clntref);
-				return 0;
+					nh_sel = nhsel;
+					goto out_fill_res;
 				}
 #else
 				if (nhsel < 1) {
-				atomic_inc(&fi->fib_clntref);
-				return 0;
+					goto out_fill_res;
 				}
 #endif
 				endfor_nexthops(fi);
-			res->fi = NULL;
-			return 1;
+				continue;
+
 			default:
-			res->fi = NULL;
 				printk(KERN_DEBUG "impossible 102\n");
 				return -EINVAL;
-		}
+			};
 		}
 		return err;
+	}
+	return 1;
+
+out_fill_res:
+	res->prefixlen = prefixlen;
+	res->nh_sel = nh_sel;
+	res->type = fa->fa_type;
+	res->scope = fa->fa_scope;
+	res->fi = fa->fa_info;
+	atomic_inc(&res->fi->fib_clntref);
+	return 0;
 }
 
 /* Find appropriate source address to this destination */