[PATCH net-next v2] net: refactor ->ndo_bpf calls into dev_xdp_propagate

From: Mina Almasry
Date: Thu Aug 22 2024 - 01:52:34 EST


When net devices propagate xdp configurations to slave devices,
we will need to perform a memory provider check to ensure we're
not binding xdp to a device using unreadable netmem.

Currently the ->ndo_bpf calls in a few places. Adding checks to all
these places would not be ideal.

Refactor all the ->ndo_bpf calls into one place where we can add this
check in the future.

Suggested-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Mina Almasry <almasrymina@xxxxxxxxxx>

---

v2:
- Don't refactor the calls in net/xdp/xsk_buff_pool.c and
kernel/bpf/offload.c (Jakub)
---
drivers/net/bonding/bond_main.c | 8 ++++----
drivers/net/hyperv/netvsc_bpf.c | 2 +-
include/linux/netdevice.h | 1 +
net/core/dev.c | 9 +++++++++
4 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index f9633a6f8571..73f9416c6c1b 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2258,7 +2258,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev,
goto err_sysfs_del;
}

- res = slave_dev->netdev_ops->ndo_bpf(slave_dev, &xdp);
+ res = dev_xdp_propagate(slave_dev, &xdp);
if (res < 0) {
/* ndo_bpf() sets extack error message */
slave_dbg(bond_dev, slave_dev, "Error %d calling ndo_bpf\n", res);
@@ -2394,7 +2394,7 @@ static int __bond_release_one(struct net_device *bond_dev,
.prog = NULL,
.extack = NULL,
};
- if (slave_dev->netdev_ops->ndo_bpf(slave_dev, &xdp))
+ if (dev_xdp_propagate(slave_dev, &xdp))
slave_warn(bond_dev, slave_dev, "failed to unload XDP program\n");
}

@@ -5584,7 +5584,7 @@ static int bond_xdp_set(struct net_device *dev, struct bpf_prog *prog,
goto err;
}

- err = slave_dev->netdev_ops->ndo_bpf(slave_dev, &xdp);
+ err = dev_xdp_propagate(slave_dev, &xdp);
if (err < 0) {
/* ndo_bpf() sets extack error message */
slave_err(dev, slave_dev, "Error %d calling ndo_bpf\n", err);
@@ -5616,7 +5616,7 @@ static int bond_xdp_set(struct net_device *dev, struct bpf_prog *prog,
if (slave == rollback_slave)
break;

- err_unwind = slave_dev->netdev_ops->ndo_bpf(slave_dev, &xdp);
+ err_unwind = dev_xdp_propagate(slave_dev, &xdp);
if (err_unwind < 0)
slave_err(dev, slave_dev,
"Error %d when unwinding XDP program change\n", err_unwind);
diff --git a/drivers/net/hyperv/netvsc_bpf.c b/drivers/net/hyperv/netvsc_bpf.c
index 4a9522689fa4..e01c5997a551 100644
--- a/drivers/net/hyperv/netvsc_bpf.c
+++ b/drivers/net/hyperv/netvsc_bpf.c
@@ -183,7 +183,7 @@ int netvsc_vf_setxdp(struct net_device *vf_netdev, struct bpf_prog *prog)
xdp.command = XDP_SETUP_PROG;
xdp.prog = prog;

- ret = vf_netdev->netdev_ops->ndo_bpf(vf_netdev, &xdp);
+ ret = dev_xdp_propagate(vf_netdev, &xdp);

if (ret && prog)
bpf_prog_put(prog);
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 614ec5d3d75b..f0ff269ce262 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3923,6 +3923,7 @@ struct sk_buff *dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,

int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog);
u8 dev_xdp_prog_count(struct net_device *dev);
+int dev_xdp_propagate(struct net_device *dev, struct netdev_bpf *bpf);
u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode);

int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb);
diff --git a/net/core/dev.c b/net/core/dev.c
index e7260889d4cb..165e9778d422 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -9369,6 +9369,15 @@ u8 dev_xdp_prog_count(struct net_device *dev)
}
EXPORT_SYMBOL_GPL(dev_xdp_prog_count);

+int dev_xdp_propagate(struct net_device *dev, struct netdev_bpf *bpf)
+{
+ if (!dev->netdev_ops->ndo_bpf)
+ return -EOPNOTSUPP;
+
+ return dev->netdev_ops->ndo_bpf(dev, bpf);
+}
+EXPORT_SYMBOL_GPL(dev_xdp_propagate);
+
u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode)
{
struct bpf_prog *prog = dev_xdp_prog(dev, mode);
--
2.46.0.295.g3b9ea8a38a-goog