Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

[linux.git] / net / core / dev.c

diff --git a/net/core/dev.c b/net/core/dev.c
index 96cf83da0d66b2db07d5504c4c3aec7da735ea46..fca407b4a6ea178d9224949bc57f89a26c97c5c1 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6852,6 +6852,32 @@ int dev_change_proto_down(struct net_device *dev, bool proto_down)
 }
 EXPORT_SYMBOL(dev_change_proto_down);
 
+bool __dev_xdp_attached(struct net_device *dev, xdp_op_t xdp_op)
+{
+       struct netdev_xdp xdp;
+
+       memset(&xdp, 0, sizeof(xdp));
+       xdp.command = XDP_QUERY_PROG;
+
+       /* Query must always succeed. */
+       WARN_ON(xdp_op(dev, &xdp) < 0);
+       return xdp.prog_attached;
+}
+
+static int dev_xdp_install(struct net_device *dev, xdp_op_t xdp_op,
+                          struct netlink_ext_ack *extack,
+                          struct bpf_prog *prog)
+{
+       struct netdev_xdp xdp;
+
+       memset(&xdp, 0, sizeof(xdp));
+       xdp.command = XDP_SETUP_PROG;
+       xdp.extack = extack;
+       xdp.prog = prog;
+
+       return xdp_op(dev, &xdp);
+}
+
 /**
  *     dev_change_xdp_fd - set or clear a bpf program for a device rx path
  *     @dev: device
@@ -6864,41 +6890,34 @@ EXPORT_SYMBOL(dev_change_proto_down);
 int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
                      int fd, u32 flags)
 {
-       int (*xdp_op)(struct net_device *dev, struct netdev_xdp *xdp);
        const struct net_device_ops *ops = dev->netdev_ops;
        struct bpf_prog *prog = NULL;
-       struct netdev_xdp xdp;
+       xdp_op_t xdp_op, xdp_chk;
        int err;
 
        ASSERT_RTNL();
 
-       xdp_op = ops->ndo_xdp;
+       xdp_op = xdp_chk = ops->ndo_xdp;
+       if (!xdp_op && (flags & XDP_FLAGS_DRV_MODE))
+               return -EOPNOTSUPP;
        if (!xdp_op || (flags & XDP_FLAGS_SKB_MODE))
                xdp_op = generic_xdp_install;
+       if (xdp_op == xdp_chk)
+               xdp_chk = generic_xdp_install;
 
        if (fd >= 0) {
-               if (flags & XDP_FLAGS_UPDATE_IF_NOEXIST) {
-                       memset(&xdp, 0, sizeof(xdp));
-                       xdp.command = XDP_QUERY_PROG;
-
-                       err = xdp_op(dev, &xdp);
-                       if (err < 0)
-                               return err;
-                       if (xdp.prog_attached)
-                               return -EBUSY;
-               }
+               if (xdp_chk && __dev_xdp_attached(dev, xdp_chk))
+                       return -EEXIST;
+               if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) &&
+                   __dev_xdp_attached(dev, xdp_op))
+                       return -EBUSY;
 
                prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_XDP);
                if (IS_ERR(prog))
                        return PTR_ERR(prog);
        }
 
-       memset(&xdp, 0, sizeof(xdp));
-       xdp.command = XDP_SETUP_PROG;
-       xdp.extack = extack;
-       xdp.prog = prog;
-
-       err = xdp_op(dev, &xdp);
+       err = dev_xdp_install(dev, xdp_op, extack, prog);
        if (err < 0 && prog)
                bpf_prog_put(prog);