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// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2019, Microsoft Corporation.
*
* Author:
* Haiyang Zhang <haiyangz@microsoft.com>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/bpf.h>
#include <linux/bpf_trace.h>
#include <linux/kernel.h>
#include <net/xdp.h>
#include <linux/mutex.h>
#include <linux/rtnetlink.h>
#include "hyperv_net.h"
u32 netvsc_run_xdp(struct net_device *ndev, struct netvsc_channel *nvchan,
struct xdp_buff *xdp)
{
void *data = nvchan->rsc.data[0];
u32 len = nvchan->rsc.len[0];
struct page *page = NULL;
struct bpf_prog *prog;
u32 act = XDP_PASS;
xdp->data_hard_start = NULL;
rcu_read_lock();
prog = rcu_dereference(nvchan->bpf_prog);
if (!prog)
goto out;
/* Ensure that the below memcpy() won't overflow the page buffer. */
if (len > ndev->mtu + ETH_HLEN) {
act = XDP_DROP;
goto out;
}
/* allocate page buffer for data */
page = alloc_page(GFP_ATOMIC);
if (!page) {
act = XDP_DROP;
goto out;
}
xdp_init_buff(xdp, PAGE_SIZE, &nvchan->xdp_rxq);
xdp_prepare_buff(xdp, page_address(page), NETVSC_XDP_HDRM, len, false);
memcpy(xdp->data, data, len);
act = bpf_prog_run_xdp(prog, xdp);
switch (act) {
case XDP_PASS:
case XDP_TX:
case XDP_DROP:
break;
case XDP_ABORTED:
trace_xdp_exception(ndev, prog, act);
break;
default:
bpf_warn_invalid_xdp_action(ndev, prog, act);
}
out:
rcu_read_unlock();
if (page && act != XDP_PASS && act != XDP_TX) {
__free_page(page);
xdp->data_hard_start = NULL;
}
return act;
}
unsigned int netvsc_xdp_fraglen(unsigned int len)
{
return SKB_DATA_ALIGN(len) +
SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
}
struct bpf_prog *netvsc_xdp_get(struct netvsc_device *nvdev)
{
return rtnl_dereference(nvdev->chan_table[0].bpf_prog);
}
int netvsc_xdp_set(struct net_device *dev, struct bpf_prog *prog,
struct netlink_ext_ack *extack,
struct netvsc_device *nvdev)
{
struct bpf_prog *old_prog;
int buf_max, i;
old_prog = netvsc_xdp_get(nvdev);
if (!old_prog && !prog)
return 0;
buf_max = NETVSC_XDP_HDRM + netvsc_xdp_fraglen(dev->mtu + ETH_HLEN);
if (prog && buf_max > PAGE_SIZE) {
netdev_err(dev, "XDP: mtu:%u too large, buf_max:%u\n",
dev->mtu, buf_max);
NL_SET_ERR_MSG_MOD(extack, "XDP: mtu too large");
return -EOPNOTSUPP;
}
if (prog && (dev->features & NETIF_F_LRO)) {
netdev_err(dev, "XDP: not support LRO\n");
NL_SET_ERR_MSG_MOD(extack, "XDP: not support LRO");
return -EOPNOTSUPP;
}
if (prog)
bpf_prog_add(prog, nvdev->num_chn - 1);
for (i = 0; i < nvdev->num_chn; i++)
rcu_assign_pointer(nvdev->chan_table[i].bpf_prog, prog);
if (old_prog)
for (i = 0; i < nvdev->num_chn; i++)
bpf_prog_put(old_prog);
return 0;
}
int netvsc_vf_setxdp(struct net_device *vf_netdev, struct bpf_prog *prog)
{
struct netdev_bpf xdp;
bpf_op_t ndo_bpf;
int ret;
ASSERT_RTNL();
if (!vf_netdev)
return 0;
ndo_bpf = vf_netdev->netdev_ops->ndo_bpf;
if (!ndo_bpf)
return 0;
memset(&xdp, 0, sizeof(xdp));
if (prog)
bpf_prog_inc(prog);
xdp.command = XDP_SETUP_PROG;
xdp.prog = prog;
ret = ndo_bpf(vf_netdev, &xdp);
if (ret && prog)
bpf_prog_put(prog);
return ret;
}
int netvsc_bpf(struct net_device *dev, struct netdev_bpf *bpf)
{
struct net_device_context *ndevctx = netdev_priv(dev);
struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
struct net_device *vf_netdev = rtnl_dereference(ndevctx->vf_netdev);
struct netlink_ext_ack *extack = bpf->extack;
int ret;
if (!nvdev || nvdev->destroy) {
return -ENODEV;
}
switch (bpf->command) {
case XDP_SETUP_PROG:
ret = netvsc_xdp_set(dev, bpf->prog, extack, nvdev);
if (ret)
return ret;
ret = netvsc_vf_setxdp(vf_netdev, bpf->prog);
if (ret) {
netdev_err(dev, "vf_setxdp failed:%d\n", ret);
NL_SET_ERR_MSG_MOD(extack, "vf_setxdp failed");
netvsc_xdp_set(dev, NULL, extack, nvdev);
}
return ret;
default:
return -EINVAL;
}
}
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