diff --git a/Documentation/networking/af_xdp.rst b/Documentation/networking/af_xdp.rst index 7a4caaaf3a17..09b3943b3b71 100644 --- a/Documentation/networking/af_xdp.rst +++ b/Documentation/networking/af_xdp.rst @@ -378,6 +378,15 @@ start N bytes into the buffer leaving the first N bytes for the application to use. The final option is the flags field, but it will be dealt with in separate sections for each UMEM flag. +SO_BINDTODEVICE setsockopt +-------------------------- + +This is a generic SOL_SOCKET option that can be used to tie AF_XDP +socket to a particular network interface. It is useful when a socket +is created by a privileged process and passed to a non-privileged one. +Once the option is set, kernel will refuse attempts to bind that socket +to a different interface. Updating the value requires CAP_NET_RAW. + XDP_STATISTICS getsockopt ------------------------- diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 2bc0d6e3e124..d04a2345bc3f 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -613,6 +613,7 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) struct sock *sk = sock->sk; struct xdp_sock *xs = xdp_sk(sk); struct net_device *dev; + int bound_dev_if; u32 flags, qid; int err = 0; @@ -626,6 +627,10 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) XDP_USE_NEED_WAKEUP)) return -EINVAL; + bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); + if (bound_dev_if && bound_dev_if != sxdp->sxdp_ifindex) + return -EINVAL; + rtnl_lock(); mutex_lock(&xs->mutex); if (xs->state != XSK_READY) {