Factor out the check and change logic from dev_change_xdp_fd(),
and export them for the following commit.
Signed-off-by: Toshiaki Makita <toshiaki.maki...@gmail.com>
---
include/linux/netdevice.h | 4 ++
net/core/dev.c | 111 +++++++++++++++++++++++++++++++++++++---------
2 files changed, 95 insertions(+), 20 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 3207e0b..c338a73 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3707,6 +3707,10 @@ struct sk_buff *dev_hard_start_xmit(struct sk_buff *skb,
struct net_device *dev,
struct netdev_queue *txq, int *ret);
typedef int (*bpf_op_t)(struct net_device *dev, struct netdev_bpf *bpf);
+int dev_check_xdp(struct net_device *dev, struct netlink_ext_ack *extack,
+ bool do_install, u32 *prog_id_p, u32 flags);
+int dev_change_xdp(struct net_device *dev, struct netlink_ext_ack *extack,
+ struct bpf_prog *prod, u32 flags);
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,
diff --git a/net/core/dev.c b/net/core/dev.c
index 8bc3dce..9965675 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -8317,23 +8317,24 @@ static void dev_xdp_uninstall(struct net_device *dev)
}
/**
- * dev_change_xdp_fd - set or clear a bpf program for a device rx path
+ * dev_check_xdp - check if xdp prog can be [un]installed
* @dev: device
* @extack: netlink extended ack
- * @fd: new program fd or negative value to clear
+ * @install: flag to install or uninstall
+ * @prog_id_p: pointer to a storage for program id
* @flags: xdp-related flags
*
- * Set or clear a bpf program for a device
+ * Check if xdp prog can be [un]installed
+ * If a program is already loaded, store the prog id to prog_id_p
*/
-int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
- int fd, u32 flags)
+int dev_check_xdp(struct net_device *dev, struct netlink_ext_ack *extack,
+ bool install, u32 *prog_id_p, u32 flags)
{
const struct net_device_ops *ops = dev->netdev_ops;
enum bpf_netdev_command query;
- struct bpf_prog *prog = NULL;
bpf_op_t bpf_op, bpf_chk;
bool offload;
- int err;
+ u32 prog_id;
ASSERT_RTNL();
@@ -8350,28 +8351,64 @@ int dev_change_xdp_fd(struct net_device *dev, struct
netlink_ext_ack *extack,
if (bpf_op == bpf_chk)
bpf_chk = generic_xdp_install;
- if (fd >= 0) {
- u32 prog_id;
-
+ if (install) {
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;
}
prog_id = __dev_xdp_query(dev, bpf_op, query);
+ if (prog_id_p)
+ *prog_id_p = prog_id;
if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && prog_id) {
NL_SET_ERR_MSG(extack, "XDP program already attached");
return -EBUSY;
}
+ } else {
+ prog_id = __dev_xdp_query(dev, bpf_op, query);
+ if (prog_id_p)
+ *prog_id_p = prog_id;
+ if (!prog_id)
+ return -ENOENT;
+ }
- prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP,
- bpf_op == ops->ndo_bpf);
- if (IS_ERR(prog))
- return PTR_ERR(prog);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dev_check_xdp);
+
+/**
+ * dev_change_xdp - set or clear a bpf program for a device rx path
+ * @dev: device
+ * @extack: netlink extended ack
+ * @prog: bpf progam
+ * @flags: xdp-related flags
+ *
+ * Set or clear a bpf program for a device.
+ * Caller must call dev_check_xdp before calling this function to
+ * check if xdp prog can be [un]installed.
+ */
+int dev_change_xdp(struct net_device *dev, struct netlink_ext_ack *extack,
+ struct bpf_prog *prog, u32 flags)
+{
+ const struct net_device_ops *ops = dev->netdev_ops;
+ enum bpf_netdev_command query;
+ bpf_op_t bpf_op;
+ bool offload;
+
+ ASSERT_RTNL();
+
+ offload = flags & XDP_FLAGS_HW_MODE;
+ query = offload ? XDP_QUERY_PROG_HW : XDP_QUERY_PROG;
+
+ bpf_op = ops->ndo_bpf;
+ if (!bpf_op || (flags & XDP_FLAGS_SKB_MODE))
+ bpf_op = generic_xdp_install;
+
+ if (prog) {
+ u32 prog_id = __dev_xdp_query(dev, bpf_op, query);
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;
}
@@ -8379,13 +8416,47 @@ int dev_change_xdp_fd(struct net_device *dev, struct
netlink_ext_ack *extack,
bpf_prog_put(prog);
return 0;
}
- } else {
- if (!__dev_xdp_query(dev, bpf_op, query))
- return 0;
}
- err = dev_xdp_install(dev, bpf_op, extack, flags, prog);
- if (err < 0 && prog)
+ return dev_xdp_install(dev, bpf_op, extack, flags, prog);
+}
+EXPORT_SYMBOL_GPL(dev_change_xdp);
+
+/**
+ * dev_change_xdp_fd - set or clear a bpf program for a device rx path
+ * @dev: device
+ * @extack: netlink extended ack
+ * @fd: new program fd or negative value to clear
+ * @flags: xdp-related flags
+ *
+ * Set or clear a bpf program for a device
+ */
+int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
+ int fd, u32 flags)
+{
+ struct bpf_prog *prog = NULL;
+ bool install = fd >= 0;
+ int err;
+
+ err = dev_check_xdp(dev, extack, install, NULL, flags);
+ if (err) {
+ if (!install && err == -ENOENT)
+ err = 0;
+ return err;
+ }
+
+ if (install) {
+ bool attach_drv;
+
+ attach_drv = dev->netdev_ops->ndo_bpf &&
+ !(flags & XDP_FLAGS_SKB_MODE);
+ prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP, attach_drv);
+ if (IS_ERR(prog))
+ return PTR_ERR(prog);
+ }
+
+ err = dev_change_xdp(dev, extack, prog, flags);
+ if (err && prog)
bpf_prog_put(prog);
return err;
--
1.8.3.1
