xsk: don't allow umem replace at stack level

Currently drivers have to check if they already have a umem
installed for a given queue and return an error if so.  Make
better use of XDP_QUERY_XSK_UMEM and move this functionality
to the core.

We need to keep rtnl across the calls now.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Björn Töpel <bjorn.topel@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jakub Kicinski 2018-07-30 20:43:53 -07:00 committed by David S. Miller
parent f734607e81
commit 84c6b86875
2 changed files with 32 additions and 12 deletions

View file

@ -872,10 +872,10 @@ struct netdev_bpf {
struct {
struct bpf_offloaded_map *offmap;
};
/* XDP_SETUP_XSK_UMEM */
/* XDP_QUERY_XSK_UMEM, XDP_SETUP_XSK_UMEM */
struct {
struct xdp_umem *umem;
u16 queue_id;
struct xdp_umem *umem; /* out for query*/
u16 queue_id; /* in for query */
} xsk;
};
};
@ -3568,6 +3568,7 @@ int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
int fd, u32 flags);
u32 __dev_xdp_query(struct net_device *dev, bpf_op_t xdp_op,
enum bpf_netdev_command cmd);
int xdp_umem_query(struct net_device *dev, u16 queue_id);
int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb);
int dev_forward_skb(struct net_device *dev, struct sk_buff *skb);

View file

@ -11,6 +11,8 @@
#include <linux/slab.h>
#include <linux/bpf.h>
#include <linux/mm.h>
#include <linux/netdevice.h>
#include <linux/rtnetlink.h>
#include "xdp_umem.h"
#include "xsk_queue.h"
@ -40,6 +42,21 @@ void xdp_del_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs)
}
}
int xdp_umem_query(struct net_device *dev, u16 queue_id)
{
struct netdev_bpf bpf;
ASSERT_RTNL();
memset(&bpf, 0, sizeof(bpf));
bpf.command = XDP_QUERY_XSK_UMEM;
bpf.xsk.queue_id = queue_id;
if (!dev->netdev_ops->ndo_bpf)
return 0;
return dev->netdev_ops->ndo_bpf(dev, &bpf) ?: !!bpf.xsk.umem;
}
int xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev,
u32 queue_id, u16 flags)
{
@ -62,28 +79,30 @@ int xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev,
bpf.command = XDP_QUERY_XSK_UMEM;
rtnl_lock();
err = dev->netdev_ops->ndo_bpf(dev, &bpf);
rtnl_unlock();
if (err)
return force_zc ? -ENOTSUPP : 0;
err = xdp_umem_query(dev, queue_id);
if (err) {
err = err < 0 ? -ENOTSUPP : -EBUSY;
goto err_rtnl_unlock;
}
bpf.command = XDP_SETUP_XSK_UMEM;
bpf.xsk.umem = umem;
bpf.xsk.queue_id = queue_id;
rtnl_lock();
err = dev->netdev_ops->ndo_bpf(dev, &bpf);
rtnl_unlock();
if (err)
return force_zc ? err : 0; /* fail or fallback */
goto err_rtnl_unlock;
rtnl_unlock();
dev_hold(dev);
umem->dev = dev;
umem->queue_id = queue_id;
umem->zc = true;
return 0;
err_rtnl_unlock:
rtnl_unlock();
return force_zc ? err : 0; /* fail or fallback */
}
static void xdp_umem_clear_dev(struct xdp_umem *umem)