Subject: [PATCH bpf-next 02/16] net: Move handling of IFLA_XDP attribute out of do_setlink

From: David Ahern <[email-masked]>
Date: Mon, 20 Apr 2020 14:00:41 -0600

From: David Ahern <[email-masked]>

Later patch re-uses XDP attributes. Move processing of IFLA_XDP
to a helper. Code move only; no functional change intended.

Signed-off-by: David Ahern <[email-masked]>
---
 net/core/rtnetlink.c | 94 +++++++++++++++++++++++---------------------
 1 file changed, 49 insertions(+), 45 deletions(-)

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 709ebbf8ab5b..97e47c292333 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -2480,6 +2480,53 @@ static int do_set_master(struct net_device *dev, int ifindex,
 #define DO_SETLINK_MODIFIED	0x01
 /* notify flag means notify + modified. */
 #define DO_SETLINK_NOTIFY	0x03
+
+static int do_setlink_xdp(struct net_device *dev, struct nlattr *tb,
+			  int *status, struct netlink_ext_ack *extack)
+{
+	struct nlattr *xdp[IFLA_XDP_MAX + 1];
+	u32 xdp_flags = 0;
+	int err;
+
+	err = nla_parse_nested_deprecated(xdp, IFLA_XDP_MAX, tb,
+					  ifla_xdp_policy, NULL);
+	if (err < 0)
+		return err;
+
+	if (xdp[IFLA_XDP_ATTACHED] || xdp[IFLA_XDP_PROG_ID])
+		goto out_einval;
+
+	if (xdp[IFLA_XDP_FLAGS]) {
+		xdp_flags = nla_get_u32(xdp[IFLA_XDP_FLAGS]);
+		if (xdp_flags & ~XDP_FLAGS_MASK)
+			goto out_einval;
+		if (hweight32(xdp_flags & XDP_FLAGS_MODES) > 1)
+			goto out_einval;
+	}
+
+	if (xdp[IFLA_XDP_FD]) {
+		int expected_fd = -1;
+
+		if (xdp_flags & XDP_FLAGS_REPLACE) {
+			if (!xdp[IFLA_XDP_EXPECTED_FD])
+				goto out_einval;
+			expected_fd = nla_get_s32(xdp[IFLA_XDP_EXPECTED_FD]);
+		}
+
+		err = dev_change_xdp_fd(dev, extack,
+					nla_get_s32(xdp[IFLA_XDP_FD]),
+					expected_fd, xdp_flags);
+		if (err)
+			return err;
+
+		*status |= DO_SETLINK_NOTIFY;
+	}
+
+	return 0;
+out_einval:
+	return -EINVAL;
+}
+
 static int do_setlink(const struct sk_buff *skb,
 		      struct net_device *dev, struct ifinfomsg *ifm,
 		      struct netlink_ext_ack *extack,
@@ -2774,52 +2821,9 @@ static int do_setlink(const struct sk_buff *skb,
 	}
 
 	if (tb[IFLA_XDP]) {
-		struct nlattr *xdp[IFLA_XDP_MAX + 1];
-		u32 xdp_flags = 0;
-
-		err = nla_parse_nested_deprecated(xdp, IFLA_XDP_MAX,
-						  tb[IFLA_XDP],
-						  ifla_xdp_policy, NULL);
-		if (err < 0)
-			goto errout;
-
-		if (xdp[IFLA_XDP_ATTACHED] || xdp[IFLA_XDP_PROG_ID]) {
-			err = -EINVAL;
+		err = do_setlink_xdp(dev, tb[IFLA_XDP], &status, extack);
+		if (err)
 			goto errout;
-		}
-
-		if (xdp[IFLA_XDP_FLAGS]) {
-			xdp_flags = nla_get_u32(xdp[IFLA_XDP_FLAGS]);
-			if (xdp_flags & ~XDP_FLAGS_MASK) {
-				err = -EINVAL;
-				goto errout;
-			}
-			if (hweight32(xdp_flags & XDP_FLAGS_MODES) > 1) {
-				err = -EINVAL;
-				goto errout;
-			}
-		}
-
-		if (xdp[IFLA_XDP_FD]) {
-			int expected_fd = -1;
-
-			if (xdp_flags & XDP_FLAGS_REPLACE) {
-				if (!xdp[IFLA_XDP_EXPECTED_FD]) {
-					err = -EINVAL;
-					goto errout;
-				}
-				expected_fd =
-					nla_get_s32(xdp[IFLA_XDP_EXPECTED_FD]);
-			}
-
-			err = dev_change_xdp_fd(dev, extack,
-						nla_get_s32(xdp[IFLA_XDP_FD]),
-						expected_fd,
-						xdp_flags);
-			if (err)
-				goto errout;
-			status |= DO_SETLINK_NOTIFY;
-		}
 	}
 
 errout:
-- 
2.21.1 (Apple Git-122.3)