Merge tag 'master-2014-12-08' of git://git.kernel.org/pub/scm/linux/kernel/git/linvil...

[karo-tx-linux.git] / net / bridge / br_input.c

diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 6fd5522df696ce744558a4db82803c34394eed6f..1f1de715197c19ab12f5333e9a518a317754f041 100644 (file)
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -16,6 +16,8 @@
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
 #include <linux/netfilter_bridge.h>
+#include <linux/neighbour.h>
+#include <net/arp.h>
 #include <linux/export.h>
 #include <linux/rculist.h>
 #include "br_private.h"
@@ -57,6 +59,60 @@ static int br_pass_frame_up(struct sk_buff *skb)
                       netif_receive_skb);
 }
 
+static void br_do_proxy_arp(struct sk_buff *skb, struct net_bridge *br,
+                           u16 vid)
+{
+       struct net_device *dev = br->dev;
+       struct neighbour *n;
+       struct arphdr *parp;
+       u8 *arpptr, *sha;
+       __be32 sip, tip;
+
+       if (dev->flags & IFF_NOARP)
+               return;
+
+       if (!pskb_may_pull(skb, arp_hdr_len(dev))) {
+               dev->stats.tx_dropped++;
+               return;
+       }
+       parp = arp_hdr(skb);
+
+       if (parp->ar_pro != htons(ETH_P_IP) ||
+           parp->ar_op != htons(ARPOP_REQUEST) ||
+           parp->ar_hln != dev->addr_len ||
+           parp->ar_pln != 4)
+               return;
+
+       arpptr = (u8 *)parp + sizeof(struct arphdr);
+       sha = arpptr;
+       arpptr += dev->addr_len;        /* sha */
+       memcpy(&sip, arpptr, sizeof(sip));
+       arpptr += sizeof(sip);
+       arpptr += dev->addr_len;        /* tha */
+       memcpy(&tip, arpptr, sizeof(tip));
+
+       if (ipv4_is_loopback(tip) ||
+           ipv4_is_multicast(tip))
+               return;
+
+       n = neigh_lookup(&arp_tbl, &tip, dev);
+       if (n) {
+               struct net_bridge_fdb_entry *f;
+
+               if (!(n->nud_state & NUD_VALID)) {
+                       neigh_release(n);
+                       return;
+               }
+
+               f = __br_fdb_get(br, n->ha, vid);
+               if (f)
+                       arp_send(ARPOP_REPLY, ETH_P_ARP, sip, skb->dev, tip,
+                                sha, n->ha, sha);
+
+               neigh_release(n);
+       }
+}
+
 /* note: already called with rcu_read_lock */
 int br_handle_frame_finish(struct sk_buff *skb)
 {
@@ -98,6 +154,10 @@ int br_handle_frame_finish(struct sk_buff *skb)
        dst = NULL;
 
        if (is_broadcast_ether_addr(dest)) {
+               if (p->flags & BR_PROXYARP &&
+                   skb->protocol == htons(ETH_P_ARP))
+                       br_do_proxy_arp(skb, br, vid);
+
                skb2 = skb;
                unicast = false;
        } else if (is_multicast_ether_addr(dest)) {