net/ipv4: Move device validation to helper

Move the device matching check in __fib_validate_source to a helper and
export it for use by netfilter modules. Code move only; no functional
change intended.

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

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 69c91d1..f7c109e 100644 (file)
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -373,6 +373,7 @@ static inline bool fib4_rules_early_flow_dissect(struct net *net,
 extern const struct nla_policy rtm_ipv4_policy[];
 void ip_fib_init(void);
 __be32 fib_compute_spec_dst(struct sk_buff *skb);
+bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev);
 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
                        u8 tos, int oif, struct net_device *dev,
                        struct in_device *idev, u32 *itag);

diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 2998b0e..222b968 100644 (file)
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -315,6 +315,32 @@ __be32 fib_compute_spec_dst(struct sk_buff *skb)
        return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
 }
 
+bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev)
+{
+       bool dev_match = false;
+       int ret;
+
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+       for (ret = 0; ret < fi->fib_nhs; ret++) {
+               struct fib_nh *nh = &fi->fib_nh[ret];
+
+               if (nh->nh_dev == dev) {
+                       dev_match = true;
+                       break;
+               } else if (l3mdev_master_ifindex_rcu(nh->nh_dev) == dev->ifindex) {
+                       dev_match = true;
+                       break;
+               }
+       }
+#else
+       if (fi->fib_nh[0].nh_dev == dev)
+               dev_match = true;
+#endif
+
+       return dev_match;
+}
+EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev);
+
 /* Given (packet source, input interface) and optional (dst, oif, tos):
  * - (main) check, that source is valid i.e. not broadcast or our local
  *   address.
@@ -361,24 +387,8 @@ static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
            (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
                goto e_inval;
        fib_combine_itag(itag, &res);
-       dev_match = false;
-
-#ifdef CONFIG_IP_ROUTE_MULTIPATH
-       for (ret = 0; ret < res.fi->fib_nhs; ret++) {
-               struct fib_nh *nh = &res.fi->fib_nh[ret];
 
-               if (nh->nh_dev == dev) {
-                       dev_match = true;
-                       break;
-               } else if (l3mdev_master_ifindex_rcu(nh->nh_dev) == dev->ifindex) {
-                       dev_match = true;
-                       break;
-               }
-       }
-#else
-       if (FIB_RES_DEV(res) == dev)
-               dev_match = true;
-#endif
+       dev_match = fib_info_nh_uses_dev(res.fi, dev);
        if (dev_match) {
                ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
                return ret;