neigh: Use neigh table index for neigh_packet_xmit

Remove a little bit of unnecessary work when transmitting a packet with
neigh_packet_xmit.  Use the neighbour table index not the address family
as a parameter.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 34 insertions, 24 deletions

diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index afb8237b0a8c..d48b8ec8b5f4 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -226,6 +226,7 @@ enum {
         NEIGH_ND_TABLE = 1,
         NEIGH_DN_TABLE = 2,
         NEIGH_NR_TABLES,
+        NEIGH_LINK_TABLE = NEIGH_NR_TABLES /* Pseudo table for neigh_xmit */
 };
 
 static inline int neigh_parms_family(struct neigh_parms *p)
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index cffaf00561e7..ad07990e943d 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -2391,22 +2391,15 @@ void __neigh_for_each_release(struct neigh_table *tbl,
 }
 EXPORT_SYMBOL(__neigh_for_each_release);
 
-int neigh_xmit(int family, struct net_device *dev,
+int neigh_xmit(int index, struct net_device *dev,
                const void *addr, struct sk_buff *skb)
 {
-        int err;
-        if (family == AF_PACKET) {
-                err = dev_hard_header(skb, dev, ntohs(skb->protocol),
-                                      addr, NULL, skb->len);
-                if (err < 0)
-                        goto out_kfree_skb;
-                err = dev_queue_xmit(skb);
-        } else {
+        int err = -EAFNOSUPPORT;
+        if (likely(index < NEIGH_NR_TABLES)) {
                 struct neigh_table *tbl;
                 struct neighbour *neigh;
 
-                err = -ENETDOWN;
-                tbl = neigh_find_table(family);
+                tbl = neigh_tables[index];
                 if (!tbl)
                         goto out;
                 neigh = __neigh_lookup_noref(tbl, addr, dev);
@@ -2417,6 +2410,13 @@ int neigh_xmit(int family, struct net_device *dev,
                         goto out_kfree_skb;
                 err = neigh->output(neigh, skb);
         }
+        else if (index == NEIGH_LINK_TABLE) {
+                err = dev_hard_header(skb, dev, ntohs(skb->protocol),
+                                      addr, NULL, skb->len);
+                if (err < 0)
+                        goto out_kfree_skb;
+                err = dev_queue_xmit(skb);
+        }
 out:
         return err;
 out_kfree_skb:
diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index e120074157de..0ad8f7141be2 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -28,9 +28,9 @@ struct mpls_route { /* next hop label forwarding entry */
         struct rcu_head         rt_rcu;
         u32                     rt_label[MAX_NEW_LABELS];
         u8                      rt_protocol; /* routing protocol that set this entry */
-        u8                      rt_labels:2,
-                                rt_via_alen:6;
-        unsigned short          rt_via_family;
+        u8                      rt_labels;
+        u8                      rt_via_alen;
+        u8                      rt_via_table;
         u8                      rt_via[0];
 };
 
@@ -201,7 +201,7 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
                 }
         }
 
-        err = neigh_xmit(rt->rt_via_family, out_dev, rt->rt_via, skb);
+        err = neigh_xmit(rt->rt_via_table, out_dev, rt->rt_via, skb);
         if (err)
                 net_dbg_ratelimited("%s: packet transmission failed: %d\n",
                                     __func__, err);
@@ -225,7 +225,7 @@ static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = {
 struct mpls_route_config {
         u32             rc_protocol;
         u32             rc_ifindex;
-        u16             rc_via_family;
+        u16             rc_via_table;
         u16             rc_via_alen;
         u8              rc_via[MAX_VIA_ALEN];
         u32             rc_label;
@@ -343,7 +343,7 @@ static int mpls_route_add(struct mpls_route_config *cfg)
                 goto errout;
 
         err = -EINVAL;
-        if ((cfg->rc_via_family == AF_PACKET) &&
+        if ((cfg->rc_via_table == NEIGH_LINK_TABLE) &&
             (dev->addr_len != cfg->rc_via_alen))
                 goto errout;
 
@@ -376,7 +376,7 @@ static int mpls_route_add(struct mpls_route_config *cfg)
                 rt->rt_label[i] = cfg->rc_output_label[i];
         rt->rt_protocol = cfg->rc_protocol;
         RCU_INIT_POINTER(rt->rt_dev, dev);
-        rt->rt_via_family = cfg->rc_via_family;
+        rt->rt_via_table = cfg->rc_via_table;
         memcpy(rt->rt_via, cfg->rc_via, cfg->rc_via_alen);
 
         mpls_route_update(net, index, NULL, rt, &cfg->rc_nlinfo);
@@ -448,15 +448,22 @@ static struct notifier_block mpls_dev_notifier = {
 };
 
 static int nla_put_via(struct sk_buff *skb,
-                       u16 family, const void *addr, int alen)
+                       u8 table, const void *addr, int alen)
 {
+        static const int table_to_family[NEIGH_NR_TABLES + 1] = {
+                AF_INET, AF_INET6, AF_DECnet, AF_PACKET,
+        };
         struct nlattr *nla;
         struct rtvia *via;
+        int family = AF_UNSPEC;
 
         nla = nla_reserve(skb, RTA_VIA, alen + 2);
         if (!nla)
                 return -EMSGSIZE;
 
+        if (table <= NEIGH_NR_TABLES)
+                family = table_to_family[table];
+
         via = nla_data(nla);
         via->rtvia_family = family;
         memcpy(via->rtvia_addr, addr, alen);
@@ -599,21 +606,23 @@ static int rtm_to_route_config(struct sk_buff *skb,  struct nlmsghdr *nlh,
                         struct rtvia *via = nla_data(nla);
                         if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr))
                                 goto errout;
-                        cfg->rc_via_family = via->rtvia_family;
                         cfg->rc_via_alen   = nla_len(nla) -
                                 offsetof(struct rtvia, rtvia_addr);
                         if (cfg->rc_via_alen > MAX_VIA_ALEN)
                                 goto errout;
 
                         /* Validate the address family */
-                        switch(cfg->rc_via_family) {
+                        switch(via->rtvia_family) {
                         case AF_PACKET:
+                                cfg->rc_via_table = NEIGH_LINK_TABLE;
                                 break;
                         case AF_INET:
+                                cfg->rc_via_table = NEIGH_ARP_TABLE;
                                 if (cfg->rc_via_alen != 4)
                                         goto errout;
                                 break;
                         case AF_INET6:
+                                cfg->rc_via_table = NEIGH_ND_TABLE;
                                 if (cfg->rc_via_alen != 16)
                                         goto errout;
                                 break;
@@ -686,7 +695,7 @@ static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
         if (rt->rt_labels &&
             nla_put_labels(skb, RTA_NEWDST, rt->rt_labels, rt->rt_label))
                 goto nla_put_failure;
-        if (nla_put_via(skb, rt->rt_via_family, rt->rt_via, rt->rt_via_alen))
+        if (nla_put_via(skb, rt->rt_via_table, rt->rt_via, rt->rt_via_alen))
                 goto nla_put_failure;
         dev = rtnl_dereference(rt->rt_dev);
         if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
@@ -799,7 +808,7 @@ static int resize_platform_label_table(struct net *net, size_t limit)
                         goto nort0;
                 RCU_INIT_POINTER(rt0->rt_dev, lo);
                 rt0->rt_protocol = RTPROT_KERNEL;
-                rt0->rt_via_family = AF_PACKET;
+                rt0->rt_via_table = NEIGH_LINK_TABLE;
                 memcpy(rt0->rt_via, lo->dev_addr, lo->addr_len);
         }
         if (limit > LABEL_IPV6_EXPLICIT_NULL) {
@@ -809,7 +818,7 @@ static int resize_platform_label_table(struct net *net, size_t limit)
                         goto nort2;
                 RCU_INIT_POINTER(rt2->rt_dev, lo);
                 rt2->rt_protocol = RTPROT_KERNEL;
-                rt2->rt_via_family = AF_PACKET;
+                rt2->rt_via_table = NEIGH_LINK_TABLE;
                 memcpy(rt2->rt_via, lo->dev_addr, lo->addr_len);
         }