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Merge branch 'bpf_link-XDP' 

Andrii Nakryiko says:

====================
Following cgroup and netns examples, implement bpf_link support for XDP.

The semantics is described in patch #2. Program and link attachments are
mutually exclusive, in the sense that neither link can replace attached
program nor program can replace attached link. Link can't replace attached
link as well, as is the case for any other bpf_link implementation.

Patch #1 refactors existing BPF program-based attachment API and centralizes
high-level query/attach decisions in generic kernel code, while drivers are
kept simple and are instructed with low-level decisions about attaching and
detaching specific bpf_prog. This also makes QUERY command unnecessary, and
patch #8 removes support for it from all kernel drivers. If that's a bad idea,
we can drop that patch altogether.

With refactoring in patch #1, adding bpf_xdp_link is completely transparent to
drivers, they are still functioning at the level of "effective" bpf_prog, that
should be called in XDP data path.

Corresponding libbpf support for BPF XDP link is added in patch #5.

v3->v4:
- fix a compilation warning in one of drivers (Jakub);

v2->v3:
- fix build when CONFIG_BPF_SYSCALL=n (kernel test robot);

v1->v2:
- fix prog refcounting bug (David);
- split dev_change_xdp_fd() changes into 2 patches (David);
- add extack messages to all user-induced errors (David).
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Alexei Starovoitov 2020-07-25 20:37:02 -07:00
parent 2b9b305fcd e8407fdeb9
commit 47960ad614
39 changed files with 665 additions and 390 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/net/ethernet/amazon/ena/ena_netdev.c
View File

@ -576,15 +576,9 @@ static int ena_xdp_set(struct net_device *netdev, struct netdev_bpf *bpf)
*/
static int ena_xdp(struct net_device *netdev, struct netdev_bpf *bpf)
{
struct ena_adapter *adapter = netdev_priv(netdev);
switch (bpf->command) {
case XDP_SETUP_PROG:
return ena_xdp_set(netdev, bpf);
case XDP_QUERY_PROG:
bpf->prog_id = adapter->xdp_bpf_prog ?
adapter->xdp_bpf_prog->aux->id : 0;
break;
default:
return -EINVAL;
}

4
drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
View File

@ -330,10 +330,6 @@ int bnxt_xdp(struct net_device *dev, struct netdev_bpf *xdp)
case XDP_SETUP_PROG:
rc = bnxt_xdp_set(bp, xdp->prog);
break;
case XDP_QUERY_PROG:
xdp->prog_id = bp->xdp_prog ? bp->xdp_prog->aux->id : 0;
rc = 0;
break;
default:
rc = -EINVAL;
break;

3
drivers/net/ethernet/cavium/thunder/nicvf_main.c
View File

@ -1906,9 +1906,6 @@ static int nicvf_xdp(struct net_device *netdev, struct netdev_bpf *xdp)
switch (xdp->command) {
case XDP_SETUP_PROG:
return nicvf_xdp_setup(nic, xdp->prog);
case XDP_QUERY_PROG:
xdp->prog_id = nic->xdp_prog ? nic->xdp_prog->aux->id : 0;
return 0;
default:
return -EINVAL;
}

5
drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
View File

@ -2077,14 +2077,9 @@ out_err:
static int dpaa2_eth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
{
struct dpaa2_eth_priv *priv = netdev_priv(dev);
switch (xdp->command) {
case XDP_SETUP_PROG:
return setup_xdp(dev, xdp->prog);
case XDP_QUERY_PROG:
xdp->prog_id = priv->xdp_prog ? priv->xdp_prog->aux->id : 0;
break;
default:
return -EINVAL;
}

3
drivers/net/ethernet/intel/i40e/i40e_main.c
View File

@ -12923,9 +12923,6 @@ static int i40e_xdp(struct net_device *dev,
switch (xdp->command) {
case XDP_SETUP_PROG:
return i40e_xdp_setup(vsi, xdp->prog);
case XDP_QUERY_PROG:
xdp->prog_id = vsi->xdp_prog ? vsi->xdp_prog->aux->id : 0;
return 0;
case XDP_SETUP_XSK_UMEM:
return i40e_xsk_umem_setup(vsi, xdp->xsk.umem,
xdp->xsk.queue_id);

3
drivers/net/ethernet/intel/ice/ice_main.c
View File

@ -2292,9 +2292,6 @@ static int ice_xdp(struct net_device *dev, struct netdev_bpf *xdp)
switch (xdp->command) {
case XDP_SETUP_PROG:
return ice_xdp_setup_prog(vsi, xdp->prog, xdp->extack);
case XDP_QUERY_PROG:
xdp->prog_id = vsi->xdp_prog ? vsi->xdp_prog->aux->id : 0;
return 0;
case XDP_SETUP_XSK_UMEM:
return ice_xsk_umem_setup(vsi, xdp->xsk.umem,
xdp->xsk.queue_id);

4
drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
View File

@ -10190,10 +10190,6 @@ static int ixgbe_xdp(struct net_device *dev, struct netdev_bpf *xdp)
switch (xdp->command) {
case XDP_SETUP_PROG:
return ixgbe_xdp_setup(dev, xdp->prog);
case XDP_QUERY_PROG:
xdp->prog_id = adapter->xdp_prog ?
adapter->xdp_prog->aux->id : 0;
return 0;
case XDP_SETUP_XSK_UMEM:
return ixgbe_xsk_umem_setup(adapter, xdp->xsk.umem,
xdp->xsk.queue_id);

6
drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
View File

@ -4502,15 +4502,9 @@ static int ixgbevf_xdp_setup(struct net_device *dev, struct bpf_prog *prog)
static int ixgbevf_xdp(struct net_device *dev, struct netdev_bpf *xdp)
{
struct ixgbevf_adapter *adapter = netdev_priv(dev);
switch (xdp->command) {
case XDP_SETUP_PROG:
return ixgbevf_xdp_setup(dev, xdp->prog);
case XDP_QUERY_PROG:
xdp->prog_id = adapter->xdp_prog ?
adapter->xdp_prog->aux->id : 0;
return 0;
default:
return -EINVAL;
}

5
drivers/net/ethernet/marvell/mvneta.c
View File

@ -4442,14 +4442,9 @@ static int mvneta_xdp_setup(struct net_device *dev, struct bpf_prog *prog,
static int mvneta_xdp(struct net_device *dev, struct netdev_bpf *xdp)
{
struct mvneta_port *pp = netdev_priv(dev);
switch (xdp->command) {
case XDP_SETUP_PROG:
return mvneta_xdp_setup(dev, xdp->prog, xdp->extack);
case XDP_QUERY_PROG:
xdp->prog_id = pp->xdp_prog ? pp->xdp_prog->aux->id : 0;
return 0;
default:
return -EINVAL;
}

3
drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
View File

@ -4656,9 +4656,6 @@ static int mvpp2_xdp(struct net_device *dev, struct netdev_bpf *xdp)
switch (xdp->command) {
case XDP_SETUP_PROG:
return mvpp2_xdp_setup(port, xdp);
case XDP_QUERY_PROG:
xdp->prog_id = port->xdp_prog ? port->xdp_prog->aux->id : 0;
return 0;
default:
return -EINVAL;
}

24
drivers/net/ethernet/mellanox/mlx4/en_netdev.c
View File

@ -2802,35 +2802,11 @@ unlock_out:
return err;
}
static u32 mlx4_xdp_query(struct net_device *dev)
{
struct mlx4_en_priv *priv = netdev_priv(dev);
struct mlx4_en_dev *mdev = priv->mdev;
const struct bpf_prog *xdp_prog;
u32 prog_id = 0;
if (!priv->tx_ring_num[TX_XDP])
return prog_id;
mutex_lock(&mdev->state_lock);
xdp_prog = rcu_dereference_protected(
priv->rx_ring[0]->xdp_prog,
lockdep_is_held(&mdev->state_lock));
if (xdp_prog)
prog_id = xdp_prog->aux->id;
mutex_unlock(&mdev->state_lock);
return prog_id;
}
static int mlx4_xdp(struct net_device *dev, struct netdev_bpf *xdp)
{
switch (xdp->command) {
case XDP_SETUP_PROG:
return mlx4_xdp_set(dev, xdp->prog);
case XDP_QUERY_PROG:
xdp->prog_id = mlx4_xdp_query(dev);
return 0;
default:
return -EINVAL;
}

18
drivers/net/ethernet/mellanox/mlx5/core/en_main.c
View File

@ -4518,29 +4518,11 @@ unlock:
return err;
}
static u32 mlx5e_xdp_query(struct net_device *dev)
{
struct mlx5e_priv *priv = netdev_priv(dev);
const struct bpf_prog *xdp_prog;
u32 prog_id = 0;
mutex_lock(&priv->state_lock);
xdp_prog = priv->channels.params.xdp_prog;
if (xdp_prog)
prog_id = xdp_prog->aux->id;
mutex_unlock(&priv->state_lock);
return prog_id;
}
static int mlx5e_xdp(struct net_device *dev, struct netdev_bpf *xdp)
{
switch (xdp->command) {
case XDP_SETUP_PROG:
return mlx5e_xdp_set(dev, xdp->prog);
case XDP_QUERY_PROG:
xdp->prog_id = mlx5e_xdp_query(dev);
return 0;
case XDP_SETUP_XSK_UMEM:
return mlx5e_xsk_setup_umem(dev, xdp->xsk.umem,
xdp->xsk.queue_id);

4
drivers/net/ethernet/netronome/nfp/nfp_net_common.c
View File

@ -3614,10 +3614,6 @@ static int nfp_net_xdp(struct net_device *netdev, struct netdev_bpf *xdp)
return nfp_net_xdp_setup_drv(nn, xdp);
case XDP_SETUP_PROG_HW:
return nfp_net_xdp_setup_hw(nn, xdp);
case XDP_QUERY_PROG:
return xdp_attachment_query(&nn->xdp, xdp);
case XDP_QUERY_PROG_HW:
return xdp_attachment_query(&nn->xdp_hw, xdp);
default:
return nfp_app_bpf(nn->app, nn, xdp);
}

3
drivers/net/ethernet/qlogic/qede/qede_filter.c
View File

@ -1045,9 +1045,6 @@ int qede_xdp(struct net_device *dev, struct netdev_bpf *xdp)
switch (xdp->command) {
case XDP_SETUP_PROG:
return qede_xdp_set(edev, xdp->prog);
case XDP_QUERY_PROG:
xdp->prog_id = edev->xdp_prog ? edev->xdp_prog->aux->id : 0;
return 0;
default:
return -EINVAL;
}

5
drivers/net/ethernet/sfc/efx.c
View File

@ -653,15 +653,10 @@ static int efx_xdp_setup_prog(struct efx_nic *efx, struct bpf_prog *prog)
static int efx_xdp(struct net_device *dev, struct netdev_bpf *xdp)
{
struct efx_nic *efx = netdev_priv(dev);
struct bpf_prog *xdp_prog;
switch (xdp->command) {
case XDP_SETUP_PROG:
return efx_xdp_setup_prog(efx, xdp->prog);
case XDP_QUERY_PROG:
xdp_prog = rtnl_dereference(efx->xdp_prog);
xdp->prog_id = xdp_prog ? xdp_prog->aux->id : 0;
return 0;
default:
return -EINVAL;
}

3
drivers/net/ethernet/socionext/netsec.c
View File

@ -1811,9 +1811,6 @@ static int netsec_xdp(struct net_device *ndev, struct netdev_bpf *xdp)
switch (xdp->command) {
case XDP_SETUP_PROG:
return netsec_xdp_setup(priv, xdp->prog, xdp->extack);
case XDP_QUERY_PROG:
xdp->prog_id = priv->xdp_prog ? priv->xdp_prog->aux->id : 0;
return 0;
default:
return -EINVAL;
}

3
drivers/net/ethernet/ti/cpsw_priv.c
View File

@ -1286,9 +1286,6 @@ int cpsw_ndo_bpf(struct net_device *ndev, struct netdev_bpf *bpf)
case XDP_SETUP_PROG:
return cpsw_xdp_prog_setup(priv, bpf);
case XDP_QUERY_PROG:
return xdp_attachment_query(&priv->xdpi, bpf);
default:
return -EINVAL;
}

21
drivers/net/hyperv/netvsc_bpf.c
View File

@ -163,16 +163,6 @@ int netvsc_vf_setxdp(struct net_device *vf_netdev, struct bpf_prog *prog)
return ret;
}
static u32 netvsc_xdp_query(struct netvsc_device *nvdev)
{
struct bpf_prog *prog = netvsc_xdp_get(nvdev);
if (prog)
return prog->aux->id;
return 0;
}
int netvsc_bpf(struct net_device *dev, struct netdev_bpf *bpf)
{
struct net_device_context *ndevctx = netdev_priv(dev);
@ -182,12 +172,7 @@ int netvsc_bpf(struct net_device *dev, struct netdev_bpf *bpf)
int ret;
if (!nvdev || nvdev->destroy) {
if (bpf->command == XDP_QUERY_PROG) {
bpf->prog_id = 0;
return 0; /* Query must always succeed */
} else {
return -ENODEV;
}
return -ENODEV;
}
switch (bpf->command) {
@ -208,10 +193,6 @@ int netvsc_bpf(struct net_device *dev, struct netdev_bpf *bpf)
return ret;
case XDP_QUERY_PROG:
bpf->prog_id = netvsc_xdp_query(nvdev);
return 0;
default:
return -EINVAL;
}

4
drivers/net/netdevsim/bpf.c
View File

@ -551,10 +551,6 @@ int nsim_bpf(struct net_device *dev, struct netdev_bpf *bpf)
ASSERT_RTNL();
switch (bpf->command) {
case XDP_QUERY_PROG:
return xdp_attachment_query(&ns->xdp, bpf);
case XDP_QUERY_PROG_HW:
return xdp_attachment_query(&ns->xdp_hw, bpf);
case XDP_SETUP_PROG:
err = nsim_setup_prog_checks(ns, bpf);
if (err)

2
drivers/net/netdevsim/netdevsim.h
View File

@ -121,7 +121,7 @@ static inline void nsim_bpf_uninit(struct netdevsim *ns)
static inline int nsim_bpf(struct net_device *dev, struct netdev_bpf *bpf)
{
return bpf->command == XDP_QUERY_PROG ? 0 : -EOPNOTSUPP;
return -EOPNOTSUPP;
}
static inline int nsim_bpf_disable_tc(struct netdevsim *ns)

15
drivers/net/tun.c
View File

@ -1184,26 +1184,11 @@ static int tun_xdp_set(struct net_device *dev, struct bpf_prog *prog,
return 0;
}
static u32 tun_xdp_query(struct net_device *dev)
{
struct tun_struct *tun = netdev_priv(dev);
const struct bpf_prog *xdp_prog;
xdp_prog = rtnl_dereference(tun->xdp_prog);
if (xdp_prog)
return xdp_prog->aux->id;
return 0;
}
static int tun_xdp(struct net_device *dev, struct netdev_bpf *xdp)
{
switch (xdp->command) {
case XDP_SETUP_PROG:
return tun_xdp_set(dev, xdp->prog, xdp->extack);
case XDP_QUERY_PROG:
xdp->prog_id = tun_xdp_query(dev);
return 0;
default:
return -EINVAL;
}

15
drivers/net/veth.c
View File

@ -1198,26 +1198,11 @@ err:
return err;
}
static u32 veth_xdp_query(struct net_device *dev)
{
struct veth_priv *priv = netdev_priv(dev);
const struct bpf_prog *xdp_prog;
xdp_prog = priv->_xdp_prog;
if (xdp_prog)
return xdp_prog->aux->id;
return 0;
}
static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
{
switch (xdp->command) {
case XDP_SETUP_PROG:
return veth_xdp_set(dev, xdp->prog, xdp->extack);
case XDP_QUERY_PROG:
xdp->prog_id = veth_xdp_query(dev);
return 0;
default:
return -EINVAL;
}

17
drivers/net/virtio_net.c
View File

@ -2490,28 +2490,11 @@ err:
return err;
}
static u32 virtnet_xdp_query(struct net_device *dev)
{
struct virtnet_info *vi = netdev_priv(dev);
const struct bpf_prog *xdp_prog;
int i;
for (i = 0; i < vi->max_queue_pairs; i++) {
xdp_prog = rtnl_dereference(vi->rq[i].xdp_prog);
if (xdp_prog)
return xdp_prog->aux->id;
}
return 0;
}
static int virtnet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
{
switch (xdp->command) {
case XDP_SETUP_PROG:
return virtnet_xdp_set(dev, xdp->prog, xdp->extack);
case XDP_QUERY_PROG:
xdp->prog_id = virtnet_xdp_query(dev);
return 0;
default:
return -EINVAL;
}

21
drivers/net/xen-netfront.c
View File

@ -1480,32 +1480,11 @@ static int xennet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
return 0;
}
static u32 xennet_xdp_query(struct net_device *dev)
{
unsigned int num_queues = dev->real_num_tx_queues;
struct netfront_info *np = netdev_priv(dev);
const struct bpf_prog *xdp_prog;
struct netfront_queue *queue;
unsigned int i;
for (i = 0; i < num_queues; ++i) {
queue = &np->queues[i];
xdp_prog = rtnl_dereference(queue->xdp_prog);
if (xdp_prog)
return xdp_prog->aux->id;
}
return 0;
}
static int xennet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
{
switch (xdp->command) {
case XDP_SETUP_PROG:
return xennet_xdp_set(dev, xdp->prog, xdp->extack);
case XDP_QUERY_PROG:
xdp->prog_id = xennet_xdp_query(dev);
return 0;
default:
return -EINVAL;
}

81
include/linux/bpf.h
View File

@ -781,6 +781,32 @@ struct bpf_array_aux {
struct work_struct work;
};
struct bpf_link {
atomic64_t refcnt;
u32 id;
enum bpf_link_type type;
const struct bpf_link_ops *ops;
struct bpf_prog *prog;
struct work_struct work;
};
struct bpf_link_ops {
void (*release)(struct bpf_link *link);
void (*dealloc)(struct bpf_link *link);
int (*update_prog)(struct bpf_link *link, struct bpf_prog *new_prog,
struct bpf_prog *old_prog);
void (*show_fdinfo)(const struct bpf_link *link, struct seq_file *seq);
int (*fill_link_info)(const struct bpf_link *link,
struct bpf_link_info *info);
};
struct bpf_link_primer {
struct bpf_link *link;
struct file *file;
int fd;
u32 id;
};
struct bpf_struct_ops_value;
struct btf_type;
struct btf_member;
@ -1164,32 +1190,6 @@ static inline bool bpf_bypass_spec_v4(void)
int bpf_map_new_fd(struct bpf_map *map, int flags);
int bpf_prog_new_fd(struct bpf_prog *prog);
struct bpf_link {
atomic64_t refcnt;
u32 id;
enum bpf_link_type type;
const struct bpf_link_ops *ops;
struct bpf_prog *prog;
struct work_struct work;
};
struct bpf_link_primer {
struct bpf_link *link;
struct file *file;
int fd;
u32 id;
};
struct bpf_link_ops {
void (*release)(struct bpf_link *link);
void (*dealloc)(struct bpf_link *link);
int (*update_prog)(struct bpf_link *link, struct bpf_prog *new_prog,
struct bpf_prog *old_prog);
void (*show_fdinfo)(const struct bpf_link *link, struct seq_file *seq);
int (*fill_link_info)(const struct bpf_link *link,
struct bpf_link_info *info);
};
void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
const struct bpf_link_ops *ops, struct bpf_prog *prog);
int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer);
@ -1401,6 +1401,35 @@ static inline void __bpf_prog_uncharge(struct user_struct *user, u32 pages)
{
}
static inline void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
const struct bpf_link_ops *ops,
struct bpf_prog *prog)
{
}
static inline int bpf_link_prime(struct bpf_link *link,
struct bpf_link_primer *primer)
{
return -EOPNOTSUPP;
}
static inline int bpf_link_settle(struct bpf_link_primer *primer)
{
return -EOPNOTSUPP;
}
static inline void bpf_link_cleanup(struct bpf_link_primer *primer)
{
}
static inline void bpf_link_inc(struct bpf_link *link)
{
}
static inline void bpf_link_put(struct bpf_link *link)
{
}
static inline int bpf_obj_get_user(const char __user *pathname, int flags)
{
return -EOPNOTSUPP;

29
include/linux/netdevice.h
View File

@ -876,8 +876,6 @@ enum bpf_netdev_command {
*/
XDP_SETUP_PROG,
XDP_SETUP_PROG_HW,
XDP_QUERY_PROG,
XDP_QUERY_PROG_HW,
/* BPF program for offload callbacks, invoked at program load time. */
BPF_OFFLOAD_MAP_ALLOC,
BPF_OFFLOAD_MAP_FREE,
@ -888,6 +886,19 @@ struct bpf_prog_offload_ops;
struct netlink_ext_ack;
struct xdp_umem;
struct xdp_dev_bulk_queue;
struct bpf_xdp_link;
enum bpf_xdp_mode {
XDP_MODE_SKB = 0,
XDP_MODE_DRV = 1,
XDP_MODE_HW = 2,
__MAX_XDP_MODE
};
struct bpf_xdp_entity {
struct bpf_prog *prog;
struct bpf_xdp_link *link;
};
struct netdev_bpf {
enum bpf_netdev_command command;
@ -898,12 +909,6 @@ struct netdev_bpf {
struct bpf_prog *prog;
struct netlink_ext_ack *extack;
};
/* XDP_QUERY_PROG, XDP_QUERY_PROG_HW */
struct {
u32 prog_id;
/* flags with which program was installed */
u32 prog_flags;
};
/* BPF_OFFLOAD_MAP_ALLOC, BPF_OFFLOAD_MAP_FREE */
struct {
struct bpf_offloaded_map *offmap;
@ -2142,6 +2147,9 @@ struct net_device {
#endif
const struct udp_tunnel_nic_info *udp_tunnel_nic_info;
struct udp_tunnel_nic *udp_tunnel_nic;
/* protected by rtnl_lock */
struct bpf_xdp_entity xdp_state[__MAX_XDP_MODE];
};
#define to_net_dev(d) container_of(d, struct net_device, dev)
@ -3817,8 +3825,9 @@ struct sk_buff *dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
typedef int (*bpf_op_t)(struct net_device *dev, struct netdev_bpf *bpf);
int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
int fd, int expected_fd, u32 flags);
u32 __dev_xdp_query(struct net_device *dev, bpf_op_t xdp_op,
enum bpf_netdev_command cmd);
int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog);
u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode);
int xdp_umem_query(struct net_device *dev, u16 queue_id);
int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb);

2
include/net/xdp.h
View File

@ -240,8 +240,6 @@ struct xdp_attachment_info {
};
struct netdev_bpf;
int xdp_attachment_query(struct xdp_attachment_info *info,
struct netdev_bpf *bpf);
bool xdp_attachment_flags_ok(struct xdp_attachment_info *info,
struct netdev_bpf *bpf);
void xdp_attachment_setup(struct xdp_attachment_info *info,

10
include/uapi/linux/bpf.h
View File

@ -230,6 +230,7 @@ enum bpf_attach_type {
BPF_CGROUP_INET_SOCK_RELEASE,
BPF_XDP_CPUMAP,
BPF_SK_LOOKUP,
BPF_XDP,
__MAX_BPF_ATTACH_TYPE
};
@ -242,6 +243,7 @@ enum bpf_link_type {
BPF_LINK_TYPE_CGROUP = 3,
BPF_LINK_TYPE_ITER = 4,
BPF_LINK_TYPE_NETNS = 5,
BPF_LINK_TYPE_XDP = 6,
MAX_BPF_LINK_TYPE,
};
@ -614,7 +616,10 @@ union bpf_attr {
struct { /* struct used by BPF_LINK_CREATE command */
__u32 prog_fd; /* eBPF program to attach */
__u32 target_fd; /* object to attach to */
union {
__u32 target_fd; /* object to attach to */
__u32 target_ifindex; /* target ifindex */
};
__u32 attach_type; /* attach type */
__u32 flags; /* extra flags */
} link_create;
@ -4064,6 +4069,9 @@ struct bpf_link_info {
__u32 netns_ino;
__u32 attach_type;
} netns;
struct {
__u32 ifindex;
} xdp;
};
} __attribute__((aligned(8)));

5
kernel/bpf/syscall.c
View File

@ -2824,6 +2824,8 @@ attach_type_to_prog_type(enum bpf_attach_type attach_type)
return BPF_PROG_TYPE_TRACING;
case BPF_SK_LOOKUP:
return BPF_PROG_TYPE_SK_LOOKUP;
case BPF_XDP:
return BPF_PROG_TYPE_XDP;
default:
return BPF_PROG_TYPE_UNSPEC;
}
@ -3921,6 +3923,9 @@ static int link_create(union bpf_attr *attr)
case BPF_PROG_TYPE_SK_LOOKUP:
ret = netns_bpf_link_create(attr, prog);
break;
case BPF_PROG_TYPE_XDP:
ret = bpf_xdp_link_attach(attr, prog);
break;
default:
ret = -EINVAL;
}

544
net/core/dev.c
View File

@ -5468,10 +5468,6 @@ static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
}
break;
case XDP_QUERY_PROG:
xdp->prog_id = old ? old->aux->id : 0;
break;
default:
ret = -EINVAL;
break;
@ -8716,84 +8712,410 @@ int dev_change_proto_down_generic(struct net_device *dev, bool proto_down)
}
EXPORT_SYMBOL(dev_change_proto_down_generic);
u32 __dev_xdp_query(struct net_device *dev, bpf_op_t bpf_op,
enum bpf_netdev_command cmd)
struct bpf_xdp_link {
struct bpf_link link;
struct net_device *dev; /* protected by rtnl_lock, no refcnt held */
int flags;
};
static enum bpf_xdp_mode dev_xdp_mode(u32 flags)
{
struct netdev_bpf xdp;
if (!bpf_op)
return 0;
memset(&xdp, 0, sizeof(xdp));
xdp.command = cmd;
/* Query must always succeed. */
WARN_ON(bpf_op(dev, &xdp) < 0 && cmd == XDP_QUERY_PROG);
return xdp.prog_id;
if (flags & XDP_FLAGS_HW_MODE)
return XDP_MODE_HW;
if (flags & XDP_FLAGS_DRV_MODE)
return XDP_MODE_DRV;
return XDP_MODE_SKB;
}
static int dev_xdp_install(struct net_device *dev, bpf_op_t bpf_op,
struct netlink_ext_ack *extack, u32 flags,
struct bpf_prog *prog)
static bpf_op_t dev_xdp_bpf_op(struct net_device *dev, enum bpf_xdp_mode mode)
{
switch (mode) {
case XDP_MODE_SKB:
return generic_xdp_install;
case XDP_MODE_DRV:
case XDP_MODE_HW:
return dev->netdev_ops->ndo_bpf;
default:
return NULL;
};
}
static struct bpf_xdp_link *dev_xdp_link(struct net_device *dev,
enum bpf_xdp_mode mode)
{
return dev->xdp_state[mode].link;
}
static struct bpf_prog *dev_xdp_prog(struct net_device *dev,
enum bpf_xdp_mode mode)
{
struct bpf_xdp_link *link = dev_xdp_link(dev, mode);
if (link)
return link->link.prog;
return dev->xdp_state[mode].prog;
}
u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode)
{
struct bpf_prog *prog = dev_xdp_prog(dev, mode);
return prog ? prog->aux->id : 0;
}
static void dev_xdp_set_link(struct net_device *dev, enum bpf_xdp_mode mode,
struct bpf_xdp_link *link)
{
dev->xdp_state[mode].link = link;
dev->xdp_state[mode].prog = NULL;
}
static void dev_xdp_set_prog(struct net_device *dev, enum bpf_xdp_mode mode,
struct bpf_prog *prog)
{
dev->xdp_state[mode].link = NULL;
dev->xdp_state[mode].prog = prog;
}
static int dev_xdp_install(struct net_device *dev, enum bpf_xdp_mode mode,
bpf_op_t bpf_op, struct netlink_ext_ack *extack,
u32 flags, struct bpf_prog *prog)
{
bool non_hw = !(flags & XDP_FLAGS_HW_MODE);
struct bpf_prog *prev_prog = NULL;
struct netdev_bpf xdp;
int err;
if (non_hw) {
prev_prog = bpf_prog_by_id(__dev_xdp_query(dev, bpf_op,
XDP_QUERY_PROG));
if (IS_ERR(prev_prog))
prev_prog = NULL;
}
memset(&xdp, 0, sizeof(xdp));
if (flags & XDP_FLAGS_HW_MODE)
xdp.command = XDP_SETUP_PROG_HW;
else
xdp.command = XDP_SETUP_PROG;
xdp.command = mode == XDP_MODE_HW ? XDP_SETUP_PROG_HW : XDP_SETUP_PROG;
xdp.extack = extack;
xdp.flags = flags;
xdp.prog = prog;
/* Drivers assume refcnt is already incremented (i.e, prog pointer is
* "moved" into driver), so they don't increment it on their own, but
* they do decrement refcnt when program is detached or replaced.
* Given net_device also owns link/prog, we need to bump refcnt here
* to prevent drivers from underflowing it.
*/
if (prog)
bpf_prog_inc(prog);
err = bpf_op(dev, &xdp);
if (!err && non_hw)
bpf_prog_change_xdp(prev_prog, prog);
if (err) {
if (prog)
bpf_prog_put(prog);
return err;
}
if (prev_prog)
bpf_prog_put(prev_prog);
if (mode != XDP_MODE_HW)
bpf_prog_change_xdp(dev_xdp_prog(dev, mode), prog);
return err;
return 0;
}
static void dev_xdp_uninstall(struct net_device *dev)
{
struct netdev_bpf xdp;
bpf_op_t ndo_bpf;
struct bpf_xdp_link *link;
struct bpf_prog *prog;
enum bpf_xdp_mode mode;
bpf_op_t bpf_op;
/* Remove generic XDP */
WARN_ON(dev_xdp_install(dev, generic_xdp_install, NULL, 0, NULL));
ASSERT_RTNL();
/* Remove from the driver */
ndo_bpf = dev->netdev_ops->ndo_bpf;
if (!ndo_bpf)
return;
for (mode = XDP_MODE_SKB; mode < __MAX_XDP_MODE; mode++) {
prog = dev_xdp_prog(dev, mode);
if (!prog)
continue;
memset(&xdp, 0, sizeof(xdp));
xdp.command = XDP_QUERY_PROG;
WARN_ON(ndo_bpf(dev, &xdp));
if (xdp.prog_id)
WARN_ON(dev_xdp_install(dev, ndo_bpf, NULL, xdp.prog_flags,
NULL));
bpf_op = dev_xdp_bpf_op(dev, mode);
if (!bpf_op)
continue;
/* Remove HW offload */
memset(&xdp, 0, sizeof(xdp));
xdp.command = XDP_QUERY_PROG_HW;
if (!ndo_bpf(dev, &xdp) && xdp.prog_id)
WARN_ON(dev_xdp_install(dev, ndo_bpf, NULL, xdp.prog_flags,
NULL));
WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
/* auto-detach link from net device */
link = dev_xdp_link(dev, mode);
if (link)
link->dev = NULL;
else
bpf_prog_put(prog);
dev_xdp_set_link(dev, mode, NULL);
}
}
static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack,
struct bpf_xdp_link *link, struct bpf_prog *new_prog,
struct bpf_prog *old_prog, u32 flags)
{
struct bpf_prog *cur_prog;
enum bpf_xdp_mode mode;
bpf_op_t bpf_op;
int err;
ASSERT_RTNL();
/* either link or prog attachment, never both */
if (link && (new_prog || old_prog))
return -EINVAL;
/* link supports only XDP mode flags */
if (link && (flags & ~XDP_FLAGS_MODES)) {
NL_SET_ERR_MSG(extack, "Invalid XDP flags for BPF link attachment");
return -EINVAL;
}
/* just one XDP mode bit should be set, zero defaults to SKB mode */
if (hweight32(flags & XDP_FLAGS_MODES) > 1) {
NL_SET_ERR_MSG(extack, "Only one XDP mode flag can be set");
return -EINVAL;
}
/* old_prog != NULL implies XDP_FLAGS_REPLACE is set */
if (old_prog && !(flags & XDP_FLAGS_REPLACE)) {
NL_SET_ERR_MSG(extack, "XDP_FLAGS_REPLACE is not specified");
return -EINVAL;
}
mode = dev_xdp_mode(flags);
/* can't replace attached link */
if (dev_xdp_link(dev, mode)) {
NL_SET_ERR_MSG(extack, "Can't replace active BPF XDP link");
return -EBUSY;
}
cur_prog = dev_xdp_prog(dev, mode);
/* can't replace attached prog with link */
if (link && cur_prog) {
NL_SET_ERR_MSG(extack, "Can't replace active XDP program with BPF link");
return -EBUSY;
}
if ((flags & XDP_FLAGS_REPLACE) && cur_prog != old_prog) {
NL_SET_ERR_MSG(extack, "Active program does not match expected");
return -EEXIST;
}
if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && cur_prog) {
NL_SET_ERR_MSG(extack, "XDP program already attached");
return -EBUSY;
}
/* put effective new program into new_prog */
if (link)
new_prog = link->link.prog;
if (new_prog) {
bool offload = mode == XDP_MODE_HW;
enum bpf_xdp_mode other_mode = mode == XDP_MODE_SKB
? XDP_MODE_DRV : XDP_MODE_SKB;
if (!offload && dev_xdp_prog(dev, other_mode)) {
NL_SET_ERR_MSG(extack, "Native and generic XDP can't be active at the same time");
return -EEXIST;
}
if (!offload && bpf_prog_is_dev_bound(new_prog->aux)) {
NL_SET_ERR_MSG(extack, "Using device-bound program without HW_MODE flag is not supported");
return -EINVAL;
}
if (new_prog->expected_attach_type == BPF_XDP_DEVMAP) {
NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device");
return -EINVAL;
}
if (new_prog->expected_attach_type == BPF_XDP_CPUMAP) {
NL_SET_ERR_MSG(extack, "BPF_XDP_CPUMAP programs can not be attached to a device");
return -EINVAL;
}
}
/* don't call drivers if the effective program didn't change */
if (new_prog != cur_prog) {
bpf_op = dev_xdp_bpf_op(dev, mode);
if (!bpf_op) {
NL_SET_ERR_MSG(extack, "Underlying driver does not support XDP in native mode");
return -EOPNOTSUPP;
}
err = dev_xdp_install(dev, mode, bpf_op, extack, flags, new_prog);
if (err)
return err;
}
if (link)
dev_xdp_set_link(dev, mode, link);
else
dev_xdp_set_prog(dev, mode, new_prog);
if (cur_prog)
bpf_prog_put(cur_prog);
return 0;
}
static int dev_xdp_attach_link(struct net_device *dev,
struct netlink_ext_ack *extack,
struct bpf_xdp_link *link)
{
return dev_xdp_attach(dev, extack, link, NULL, NULL, link->flags);
}
static int dev_xdp_detach_link(struct net_device *dev,
struct netlink_ext_ack *extack,
struct bpf_xdp_link *link)
{
enum bpf_xdp_mode mode;
bpf_op_t bpf_op;
ASSERT_RTNL();
mode = dev_xdp_mode(link->flags);
if (dev_xdp_link(dev, mode) != link)
return -EINVAL;
bpf_op = dev_xdp_bpf_op(dev, mode);
WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
dev_xdp_set_link(dev, mode, NULL);
return 0;
}
static void bpf_xdp_link_release(struct bpf_link *link)
{
struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
rtnl_lock();
/* if racing with net_device's tear down, xdp_link->dev might be
* already NULL, in which case link was already auto-detached
*/
if (xdp_link->dev)
WARN_ON(dev_xdp_detach_link(xdp_link->dev, NULL, xdp_link));
rtnl_unlock();
}
static void bpf_xdp_link_dealloc(struct bpf_link *link)
{
struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
kfree(xdp_link);
}
static void bpf_xdp_link_show_fdinfo(const struct bpf_link *link,
struct seq_file *seq)
{
struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
u32 ifindex = 0;
rtnl_lock();
if (xdp_link->dev)
ifindex = xdp_link->dev->ifindex;
rtnl_unlock();
seq_printf(seq, "ifindex:\t%u\n", ifindex);
}
static int bpf_xdp_link_fill_link_info(const struct bpf_link *link,
struct bpf_link_info *info)
{
struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
u32 ifindex = 0;
rtnl_lock();
if (xdp_link->dev)
ifindex = xdp_link->dev->ifindex;
rtnl_unlock();
info->xdp.ifindex = ifindex;
return 0;
}
static int bpf_xdp_link_update(struct bpf_link *link, struct bpf_prog *new_prog,
struct bpf_prog *old_prog)
{
struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
enum bpf_xdp_mode mode;
bpf_op_t bpf_op;
int err = 0;
rtnl_lock();
/* link might have been auto-released already, so fail */
if (!xdp_link->dev) {
err = -ENOLINK;
goto out_unlock;
}
if (old_prog && link->prog != old_prog) {
err = -EPERM;
goto out_unlock;
}
old_prog = link->prog;
if (old_prog == new_prog) {
/* no-op, don't disturb drivers */
bpf_prog_put(new_prog);
goto out_unlock;
}
mode = dev_xdp_mode(xdp_link->flags);
bpf_op = dev_xdp_bpf_op(xdp_link->dev, mode);
err = dev_xdp_install(xdp_link->dev, mode, bpf_op, NULL,
xdp_link->flags, new_prog);
if (err)
goto out_unlock;
old_prog = xchg(&link->prog, new_prog);
bpf_prog_put(old_prog);
out_unlock:
rtnl_unlock();
return err;
}
static const struct bpf_link_ops bpf_xdp_link_lops = {
.release = bpf_xdp_link_release,
.dealloc = bpf_xdp_link_dealloc,
.show_fdinfo = bpf_xdp_link_show_fdinfo,
.fill_link_info = bpf_xdp_link_fill_link_info,
.update_prog = bpf_xdp_link_update,
};
int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
{
struct net *net = current->nsproxy->net_ns;
struct bpf_link_primer link_primer;
struct bpf_xdp_link *link;
struct net_device *dev;
int err, fd;
dev = dev_get_by_index(net, attr->link_create.target_ifindex);
if (!dev)
return -EINVAL;
link = kzalloc(sizeof(*link), GFP_USER);
if (!link) {
err = -ENOMEM;
goto out_put_dev;
}
bpf_link_init(&link->link, BPF_LINK_TYPE_XDP, &bpf_xdp_link_lops, prog);
link->dev = dev;
link->flags = attr->link_create.flags;
err = bpf_link_prime(&link->link, &link_primer);
if (err) {
kfree(link);
goto out_put_dev;
}
rtnl_lock();
err = dev_xdp_attach_link(dev, NULL, link);
rtnl_unlock();
if (err) {
bpf_link_cleanup(&link_primer);
goto out_put_dev;
}
fd = bpf_link_settle(&link_primer);
/* link itself doesn't hold dev's refcnt to not complicate shutdown */
dev_put(dev);
return fd;
out_put_dev:
dev_put(dev);
return err;
}
/**
@ -8809,96 +9131,36 @@ static void dev_xdp_uninstall(struct net_device *dev)
int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
int fd, int expected_fd, u32 flags)
{
const struct net_device_ops *ops = dev->netdev_ops;
enum bpf_netdev_command query;
u32 prog_id, expected_id = 0;
bpf_op_t bpf_op, bpf_chk;
struct bpf_prog *prog;
bool offload;
enum bpf_xdp_mode mode = dev_xdp_mode(flags);
struct bpf_prog *new_prog = NULL, *old_prog = NULL;
int err;
ASSERT_RTNL();
offload = flags & XDP_FLAGS_HW_MODE;
query = offload ? XDP_QUERY_PROG_HW : XDP_QUERY_PROG;
bpf_op = bpf_chk = ops->ndo_bpf;
if (!bpf_op && (flags & (XDP_FLAGS_DRV_MODE | XDP_FLAGS_HW_MODE))) {
NL_SET_ERR_MSG(extack, "underlying driver does not support XDP in native mode");
return -EOPNOTSUPP;
}
if (!bpf_op || (flags & XDP_FLAGS_SKB_MODE))
bpf_op = generic_xdp_install;
if (bpf_op == bpf_chk)
bpf_chk = generic_xdp_install;
prog_id = __dev_xdp_query(dev, bpf_op, query);
if (flags & XDP_FLAGS_REPLACE) {
if (expected_fd >= 0) {
prog = bpf_prog_get_type_dev(expected_fd,
BPF_PROG_TYPE_XDP,
bpf_op == ops->ndo_bpf);
if (IS_ERR(prog))
return PTR_ERR(prog);
expected_id = prog->aux->id;
bpf_prog_put(prog);
}
if (prog_id != expected_id) {
NL_SET_ERR_MSG(extack, "Active program does not match expected");
return -EEXIST;
}
}
if (fd >= 0) {
if (!offload && __dev_xdp_query(dev, bpf_chk, XDP_QUERY_PROG)) {
NL_SET_ERR_MSG(extack, "native and generic XDP can't be active at the same time");
return -EEXIST;
}
if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && prog_id) {
NL_SET_ERR_MSG(extack, "XDP program already attached");
return -EBUSY;
}
prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP,
bpf_op == ops->ndo_bpf);
if (IS_ERR(prog))
return PTR_ERR(prog);
if (!offload && bpf_prog_is_dev_bound(prog->aux)) {
NL_SET_ERR_MSG(extack, "using device-bound program without HW_MODE flag is not supported");
bpf_prog_put(prog);
return -EINVAL;
}
if (prog->expected_attach_type == BPF_XDP_DEVMAP) {
NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device");
bpf_prog_put(prog);
return -EINVAL;
}
if (prog->expected_attach_type == BPF_XDP_CPUMAP) {
NL_SET_ERR_MSG(extack,
"BPF_XDP_CPUMAP programs can not be attached to a device");
bpf_prog_put(prog);
return -EINVAL;
}
/* prog->aux->id may be 0 for orphaned device-bound progs */
if (prog->aux->id && prog->aux->id == prog_id) {
bpf_prog_put(prog);
return 0;
}
} else {
if (!prog_id)
return 0;
prog = NULL;
new_prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP,
mode != XDP_MODE_SKB);
if (IS_ERR(new_prog))
return PTR_ERR(new_prog);
}
err = dev_xdp_install(dev, bpf_op, extack, flags, prog);
if (err < 0 && prog)
bpf_prog_put(prog);
if (expected_fd >= 0) {
old_prog = bpf_prog_get_type_dev(expected_fd, BPF_PROG_TYPE_XDP,
mode != XDP_MODE_SKB);
if (IS_ERR(old_prog)) {
err = PTR_ERR(old_prog);
old_prog = NULL;
goto err_out;
}
}
err = dev_xdp_attach(dev, extack, NULL, new_prog, old_prog, flags);
err_out:
if (err && new_prog)
bpf_prog_put(new_prog);
if (old_prog)
bpf_prog_put(old_prog);
return err;
}

5
net/core/rtnetlink.c
View File

@ -1416,13 +1416,12 @@ static u32 rtnl_xdp_prog_skb(struct net_device *dev)
static u32 rtnl_xdp_prog_drv(struct net_device *dev)
{
return __dev_xdp_query(dev, dev->netdev_ops->ndo_bpf, XDP_QUERY_PROG);
return dev_xdp_prog_id(dev, XDP_MODE_DRV);
}
static u32 rtnl_xdp_prog_hw(struct net_device *dev)
{
return __dev_xdp_query(dev, dev->netdev_ops->ndo_bpf,
XDP_QUERY_PROG_HW);
return dev_xdp_prog_id(dev, XDP_MODE_HW);
}
static int rtnl_xdp_report_one(struct sk_buff *skb, struct net_device *dev,

9
net/core/xdp.c
View File

@ -400,15 +400,6 @@ void __xdp_release_frame(void *data, struct xdp_mem_info *mem)
}
EXPORT_SYMBOL_GPL(__xdp_release_frame);
int xdp_attachment_query(struct xdp_attachment_info *info,
struct netdev_bpf *bpf)
{
bpf->prog_id = info->prog ? info->prog->aux->id : 0;
bpf->prog_flags = info->prog ? info->flags : 0;
return 0;
}
EXPORT_SYMBOL_GPL(xdp_attachment_query);
bool xdp_attachment_flags_ok(struct xdp_attachment_info *info,
struct netdev_bpf *bpf)
{

10
tools/include/uapi/linux/bpf.h
View File

@ -230,6 +230,7 @@ enum bpf_attach_type {
BPF_CGROUP_INET_SOCK_RELEASE,
BPF_XDP_CPUMAP,
BPF_SK_LOOKUP,
BPF_XDP,
__MAX_BPF_ATTACH_TYPE
};
@ -242,6 +243,7 @@ enum bpf_link_type {
BPF_LINK_TYPE_CGROUP = 3,
BPF_LINK_TYPE_ITER = 4,
BPF_LINK_TYPE_NETNS = 5,
BPF_LINK_TYPE_XDP = 6,
MAX_BPF_LINK_TYPE,
};
@ -614,7 +616,10 @@ union bpf_attr {
struct { /* struct used by BPF_LINK_CREATE command */
__u32 prog_fd; /* eBPF program to attach */
__u32 target_fd; /* object to attach to */
union {
__u32 target_fd; /* object to attach to */
__u32 target_ifindex; /* target ifindex */
};
__u32 attach_type; /* attach type */
__u32 flags; /* extra flags */
} link_create;
@ -4064,6 +4069,9 @@ struct bpf_link_info {
__u32 netns_ino;
__u32 attach_type;
} netns;
struct {
__u32 ifindex;
} xdp;
};
} __attribute__((aligned(8)));

9
tools/lib/bpf/libbpf.c
View File

@ -6915,7 +6915,8 @@ static const struct bpf_sec_def section_defs[] = {
BPF_XDP_DEVMAP),
BPF_EAPROG_SEC("xdp_cpumap/", BPF_PROG_TYPE_XDP,
BPF_XDP_CPUMAP),
BPF_PROG_SEC("xdp", BPF_PROG_TYPE_XDP),
BPF_EAPROG_SEC("xdp", BPF_PROG_TYPE_XDP,
BPF_XDP),
BPF_PROG_SEC("perf_event", BPF_PROG_TYPE_PERF_EVENT),
BPF_PROG_SEC("lwt_in", BPF_PROG_TYPE_LWT_IN),
BPF_PROG_SEC("lwt_out", BPF_PROG_TYPE_LWT_OUT),
@ -8281,6 +8282,12 @@ bpf_program__attach_netns(struct bpf_program *prog, int netns_fd)
return bpf_program__attach_fd(prog, netns_fd, "netns");
}
struct bpf_link *bpf_program__attach_xdp(struct bpf_program *prog, int ifindex)
{
/* target_fd/target_ifindex use the same field in LINK_CREATE */
return bpf_program__attach_fd(prog, ifindex, "xdp");
}
struct bpf_link *
bpf_program__attach_iter(struct bpf_program *prog,
const struct bpf_iter_attach_opts *opts)

2
tools/lib/bpf/libbpf.h
View File

@ -257,6 +257,8 @@ LIBBPF_API struct bpf_link *
bpf_program__attach_cgroup(struct bpf_program *prog, int cgroup_fd);
LIBBPF_API struct bpf_link *
bpf_program__attach_netns(struct bpf_program *prog, int netns_fd);
LIBBPF_API struct bpf_link *
bpf_program__attach_xdp(struct bpf_program *prog, int ifindex);
struct bpf_map;

1
tools/lib/bpf/libbpf.map
View File

@ -286,6 +286,7 @@ LIBBPF_0.1.0 {
bpf_map__set_value_size;
bpf_map__type;
bpf_map__value_size;
bpf_program__attach_xdp;
bpf_program__autoload;
bpf_program__is_sk_lookup;
bpf_program__set_autoload;

2
tools/testing/selftests/bpf/prog_tests/section_names.c
View File

@ -35,7 +35,7 @@ static struct sec_name_test tests[] = {
{-EINVAL, 0},
},
{"raw_tp/", {0, BPF_PROG_TYPE_RAW_TRACEPOINT, 0}, {-EINVAL, 0} },
{"xdp", {0, BPF_PROG_TYPE_XDP, 0}, {-EINVAL, 0} },
{"xdp", {0, BPF_PROG_TYPE_XDP, BPF_XDP}, {0, BPF_XDP} },
{"perf_event", {0, BPF_PROG_TYPE_PERF_EVENT, 0}, {-EINVAL, 0} },
{"lwt_in", {0, BPF_PROG_TYPE_LWT_IN, 0}, {-EINVAL, 0} },
{"lwt_out", {0, BPF_PROG_TYPE_LWT_OUT, 0}, {-EINVAL, 0} },

137
tools/testing/selftests/bpf/prog_tests/xdp_link.c Normal file
View File

@ -0,0 +1,137 @@
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Facebook */
#include <uapi/linux/if_link.h>
#include <test_progs.h>
#include "test_xdp_link.skel.h"
#define IFINDEX_LO 1
void test_xdp_link(void)
{
__u32 duration = 0, id1, id2, id0 = 0, prog_fd1, prog_fd2, err;
DECLARE_LIBBPF_OPTS(bpf_xdp_set_link_opts, opts, .old_fd = -1);
struct test_xdp_link *skel1 = NULL, *skel2 = NULL;
struct bpf_link_info link_info;
struct bpf_prog_info prog_info;
struct bpf_link *link;
__u32 link_info_len = sizeof(link_info);
__u32 prog_info_len = sizeof(prog_info);
skel1 = test_xdp_link__open_and_load();
if (CHECK(!skel1, "skel_load", "skeleton open and load failed\n"))
goto cleanup;
prog_fd1 = bpf_program__fd(skel1->progs.xdp_handler);
skel2 = test_xdp_link__open_and_load();
if (CHECK(!skel2, "skel_load", "skeleton open and load failed\n"))
goto cleanup;
prog_fd2 = bpf_program__fd(skel2->progs.xdp_handler);
memset(&prog_info, 0, sizeof(prog_info));
err = bpf_obj_get_info_by_fd(prog_fd1, &prog_info, &prog_info_len);
if (CHECK(err, "fd_info1", "failed %d\n", -errno))
goto cleanup;
id1 = prog_info.id;
memset(&prog_info, 0, sizeof(prog_info));
err = bpf_obj_get_info_by_fd(prog_fd2, &prog_info, &prog_info_len);
if (CHECK(err, "fd_info2", "failed %d\n", -errno))
goto cleanup;
id2 = prog_info.id;
/* set initial prog attachment */
err = bpf_set_link_xdp_fd_opts(IFINDEX_LO, prog_fd1, XDP_FLAGS_REPLACE, &opts);
if (CHECK(err, "fd_attach", "initial prog attach failed: %d\n", err))
goto cleanup;
/* validate prog ID */
err = bpf_get_link_xdp_id(IFINDEX_LO, &id0, 0);
CHECK(err || id0 != id1, "id1_check",
"loaded prog id %u != id1 %u, err %d", id0, id1, err);
/* BPF link is not allowed to replace prog attachment */
link = bpf_program__attach_xdp(skel1->progs.xdp_handler, IFINDEX_LO);
if (CHECK(!IS_ERR(link), "link_attach_fail", "unexpected success\n")) {
bpf_link__destroy(link);
/* best-effort detach prog */
opts.old_fd = prog_fd1;
bpf_set_link_xdp_fd_opts(IFINDEX_LO, -1, XDP_FLAGS_REPLACE, &opts);
goto cleanup;
}
/* detach BPF program */
opts.old_fd = prog_fd1;
err = bpf_set_link_xdp_fd_opts(IFINDEX_LO, -1, XDP_FLAGS_REPLACE, &opts);
if (CHECK(err, "prog_detach", "failed %d\n", err))
goto cleanup;
/* now BPF link should attach successfully */
link = bpf_program__attach_xdp(skel1->progs.xdp_handler, IFINDEX_LO);
if (CHECK(IS_ERR(link), "link_attach", "failed: %ld\n", PTR_ERR(link)))
goto cleanup;
skel1->links.xdp_handler = link;
/* validate prog ID */
err = bpf_get_link_xdp_id(IFINDEX_LO, &id0, 0);
if (CHECK(err || id0 != id1, "id1_check",
"loaded prog id %u != id1 %u, err %d", id0, id1, err))
goto cleanup;
/* BPF prog attach is not allowed to replace BPF link */
opts.old_fd = prog_fd1;
err = bpf_set_link_xdp_fd_opts(IFINDEX_LO, prog_fd2, XDP_FLAGS_REPLACE, &opts);
if (CHECK(!err, "prog_attach_fail", "unexpected success\n"))
goto cleanup;
/* Can't force-update when BPF link is active */
err = bpf_set_link_xdp_fd(IFINDEX_LO, prog_fd2, 0);
if (CHECK(!err, "prog_update_fail", "unexpected success\n"))
goto cleanup;
/* Can't force-detach when BPF link is active */
err = bpf_set_link_xdp_fd(IFINDEX_LO, -1, 0);
if (CHECK(!err, "prog_detach_fail", "unexpected success\n"))
goto cleanup;
/* BPF link is not allowed to replace another BPF link */
link = bpf_program__attach_xdp(skel2->progs.xdp_handler, IFINDEX_LO);
if (CHECK(!IS_ERR(link), "link_attach_fail", "unexpected success\n")) {
bpf_link__destroy(link);
goto cleanup;
}
bpf_link__destroy(skel1->links.xdp_handler);
skel1->links.xdp_handler = NULL;
/* new link attach should succeed */
link = bpf_program__attach_xdp(skel2->progs.xdp_handler, IFINDEX_LO);
if (CHECK(IS_ERR(link), "link_attach", "failed: %ld\n", PTR_ERR(link)))
goto cleanup;
skel2->links.xdp_handler = link;
err = bpf_get_link_xdp_id(IFINDEX_LO, &id0, 0);
if (CHECK(err || id0 != id2, "id2_check",
"loaded prog id %u != id2 %u, err %d", id0, id1, err))
goto cleanup;
/* updating program under active BPF link works as expected */
err = bpf_link__update_program(link, skel1->progs.xdp_handler);
if (CHECK(err, "link_upd", "failed: %d\n", err))
goto cleanup;
memset(&link_info, 0, sizeof(link_info));
err = bpf_obj_get_info_by_fd(bpf_link__fd(link), &link_info, &link_info_len);
if (CHECK(err, "link_info", "failed: %d\n", err))
goto cleanup;
CHECK(link_info.type != BPF_LINK_TYPE_XDP, "link_type",
"got %u != exp %u\n", link_info.type, BPF_LINK_TYPE_XDP);
CHECK(link_info.prog_id != id1, "link_prog_id",
"got %u != exp %u\n", link_info.prog_id, id1);
CHECK(link_info.xdp.ifindex != IFINDEX_LO, "link_ifindex",
"got %u != exp %u\n", link_info.xdp.ifindex, IFINDEX_LO);
cleanup:
test_xdp_link__destroy(skel1);
test_xdp_link__destroy(skel2);
}

12
tools/testing/selftests/bpf/progs/test_xdp_link.c Normal file
View File

@ -0,0 +1,12 @@
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Facebook */
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
char LICENSE[] SEC("license") = "GPL";
SEC("xdp/handler")
int xdp_handler(struct xdp_md *xdp)
{
return 0;
}