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// SPDX-License-Identifier: GPL-2.0
/* XDP sockets
*
* AF_XDP sockets allows a channel between XDP programs and userspace
* applications.
* Copyright(c) 2018 Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* Author(s): Björn Töpel <bjorn.topel@intel.com>
* Magnus Karlsson <magnus.karlsson@intel.com>
*/
#define pr_fmt(fmt) "AF_XDP: %s: " fmt, __func__
#include <linux/if_xdp.h>
#include <linux/init.h>
#include <linux/sched/mm.h>
#include <linux/sched/signal.h>
#include <linux/sched/task.h>
#include <linux/socket.h>
#include <linux/file.h>
#include <linux/uaccess.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <net/xdp_sock.h>
#include "xdp_umem.h"
static struct xdp_sock *xdp_sk(struct sock *sk)
{
return (struct xdp_sock *)sk;
}
static int xsk_release(struct socket *sock)
{
struct sock *sk = sock->sk;
struct net *net;
if (!sk)
return 0;
net = sock_net(sk);
local_bh_disable();
sock_prot_inuse_add(net, sk->sk_prot, -1);
local_bh_enable();
sock_orphan(sk);
sock->sk = NULL;
sk_refcnt_debug_release(sk);
sock_put(sk);
return 0;
}
static int xsk_setsockopt(struct socket *sock, int level, int optname,
char __user *optval, unsigned int optlen)
{
struct sock *sk = sock->sk;
struct xdp_sock *xs = xdp_sk(sk);
int err;
if (level != SOL_XDP)
return -ENOPROTOOPT;
switch (optname) {
case XDP_UMEM_REG:
{
struct xdp_umem_reg mr;
struct xdp_umem *umem;
if (xs->umem)
return -EBUSY;
if (copy_from_user(&mr, optval, sizeof(mr)))
return -EFAULT;
mutex_lock(&xs->mutex);
err = xdp_umem_create(&umem);
err = xdp_umem_reg(umem, &mr);
if (err) {
kfree(umem);
mutex_unlock(&xs->mutex);
return err;
}
/* Make sure umem is ready before it can be seen by others */
smp_wmb();
xs->umem = umem;
mutex_unlock(&xs->mutex);
return 0;
}
default:
break;
}
return -ENOPROTOOPT;
}
static struct proto xsk_proto = {
.name = "XDP",
.owner = THIS_MODULE,
.obj_size = sizeof(struct xdp_sock),
};
static const struct proto_ops xsk_proto_ops = {
.family = PF_XDP,
.owner = THIS_MODULE,
.release = xsk_release,
.bind = sock_no_bind,
.connect = sock_no_connect,
.socketpair = sock_no_socketpair,
.accept = sock_no_accept,
.getname = sock_no_getname,
.poll = sock_no_poll,
.ioctl = sock_no_ioctl,
.listen = sock_no_listen,
.shutdown = sock_no_shutdown,
.setsockopt = xsk_setsockopt,
.getsockopt = sock_no_getsockopt,
.sendmsg = sock_no_sendmsg,
.recvmsg = sock_no_recvmsg,
.mmap = sock_no_mmap,
.sendpage = sock_no_sendpage,
};
static void xsk_destruct(struct sock *sk)
{
struct xdp_sock *xs = xdp_sk(sk);
if (!sock_flag(sk, SOCK_DEAD))
return;
xdp_put_umem(xs->umem);
sk_refcnt_debug_dec(sk);
}
static int xsk_create(struct net *net, struct socket *sock, int protocol,
int kern)
{
struct sock *sk;
struct xdp_sock *xs;
if (!ns_capable(net->user_ns, CAP_NET_RAW))
return -EPERM;
if (sock->type != SOCK_RAW)
return -ESOCKTNOSUPPORT;
if (protocol)
return -EPROTONOSUPPORT;
sock->state = SS_UNCONNECTED;
sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern);
if (!sk)
return -ENOBUFS;
sock->ops = &xsk_proto_ops;
sock_init_data(sock, sk);
sk->sk_family = PF_XDP;
sk->sk_destruct = xsk_destruct;
sk_refcnt_debug_inc(sk);
xs = xdp_sk(sk);
mutex_init(&xs->mutex);
local_bh_disable();
sock_prot_inuse_add(net, &xsk_proto, 1);
local_bh_enable();
return 0;
}
static const struct net_proto_family xsk_family_ops = {
.family = PF_XDP,
.create = xsk_create,
.owner = THIS_MODULE,
};
static int __init xsk_init(void)
{
int err;
err = proto_register(&xsk_proto, 0 /* no slab */);
if (err)
goto out;
err = sock_register(&xsk_family_ops);
if (err)
goto out_proto;
return 0;
out_proto:
proto_unregister(&xsk_proto);
out:
return err;
}
fs_initcall(xsk_init);
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