llc: add support for SO_BINDTODEVICE

Using bind(MAC address) with LLC sockets has O(n) complexity, where n
is the number of interfaces. To overcome this, we add support for
SO_BINDTODEVICE which drops the complexity to O(1).

Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c
index ac691fe0807680f043926538a9fd51b13ffef3e2..c4d1a1da813cdfccae6ead39c0a1fda255b471d1 100644 (file)
--- a/net/llc/af_llc.c
+++ b/net/llc/af_llc.c
@@ -259,7 +259,14 @@ static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
        if (!sock_flag(sk, SOCK_ZAPPED))
                goto out;
        rc = -ENODEV;
-       llc->dev = dev_getfirstbyhwtype(&init_net, addr->sllc_arphrd);
+       if (sk->sk_bound_dev_if) {
+               llc->dev = dev_get_by_index(&init_net, sk->sk_bound_dev_if);
+               if (llc->dev && addr->sllc_arphrd != llc->dev->type) {
+                       dev_put(llc->dev);
+                       llc->dev = NULL;
+               }
+       } else
+               llc->dev = dev_getfirstbyhwtype(&init_net, addr->sllc_arphrd);
        if (!llc->dev)
                goto out;
        rc = -EUSERS;
@@ -310,7 +317,25 @@ static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
                goto out;
        rc = -ENODEV;
        rtnl_lock();
-       llc->dev = dev_getbyhwaddr(&init_net, addr->sllc_arphrd, addr->sllc_mac);
+       if (sk->sk_bound_dev_if) {
+               llc->dev = dev_get_by_index(&init_net, sk->sk_bound_dev_if);
+               if (llc->dev) {
+                       if (!addr->sllc_arphrd)
+                               addr->sllc_arphrd = llc->dev->type;
+                       if (llc_mac_null(addr->sllc_mac))
+                               memcpy(addr->sllc_mac, llc->dev->dev_addr,
+                                      IFHWADDRLEN);
+                       if (addr->sllc_arphrd != llc->dev->type ||
+                           !llc_mac_match(addr->sllc_mac,
+                                          llc->dev->dev_addr)) {
+                               rc = -EINVAL;
+                               dev_put(llc->dev);
+                               llc->dev = NULL;
+                       }
+               }
+       } else
+               llc->dev = dev_getbyhwaddr(&init_net, addr->sllc_arphrd,
+                                          addr->sllc_mac);
        rtnl_unlock();
        if (!llc->dev)
                goto out;