net/sched: cls_flower: rework TCA_FLOWER_KEY_ENC_FLAGS usage

This patch changes how TCA_FLOWER_KEY_ENC_FLAGS is used, so that
it is used with TCA_FLOWER_KEY_FLAGS_* flags, in the same way as
TCA_FLOWER_KEY_FLAGS is currently used.

Where TCA_FLOWER_KEY_FLAGS uses {key,mask}->control.flags, then
TCA_FLOWER_KEY_ENC_FLAGS now uses {key,mask}->enc_control.flags,
therefore {key,mask}->enc_flags is now unused.

As the generic fl_set_key_flags/fl_dump_key_flags() is used with
encap set to true, then fl_{set,dump}_key_enc_flags() is removed.

This breaks unreleased userspace API (net-next since 2024-06-04).

Signed-off-by: Asbjørn Sloth Tønnesen <[email protected]>
Tested-by: Davide Caratti <[email protected]>
Reviewed-by: Davide Caratti <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: Asbjørn Sloth Tønnesen

include/uapi/linux/pkt_cls.h

@@ -554,8 +554,8 @@ enum {
 	TCA_FLOWER_KEY_SPI,		/* be32 */
 	TCA_FLOWER_KEY_SPI_MASK,	/* be32 */
 
-	TCA_FLOWER_KEY_ENC_FLAGS,	/* u32 */
-	TCA_FLOWER_KEY_ENC_FLAGS_MASK,	/* u32 */
+	TCA_FLOWER_KEY_ENC_FLAGS,	/* be32 */
+	TCA_FLOWER_KEY_ENC_FLAGS_MASK,	/* be32 */
 
 	__TCA_FLOWER_MAX,
 };

net/sched/cls_flower.c

@@ -45,11 +45,11 @@
 		(TCA_FLOWER_KEY_FLAGS_IS_FRAGMENT | \
 		TCA_FLOWER_KEY_FLAGS_FRAG_IS_FIRST)
 
-#define TUNNEL_FLAGS_PRESENT (\
-	_BITUL(IP_TUNNEL_CSUM_BIT) |		\
-	_BITUL(IP_TUNNEL_DONT_FRAGMENT_BIT) |	\
-	_BITUL(IP_TUNNEL_OAM_BIT) |		\
-	_BITUL(IP_TUNNEL_CRIT_OPT_BIT))
+#define TCA_FLOWER_KEY_ENC_FLAGS_POLICY_MASK \
+		(TCA_FLOWER_KEY_FLAGS_TUNNEL_CSUM | \
+		TCA_FLOWER_KEY_FLAGS_TUNNEL_DONT_FRAGMENT | \
+		TCA_FLOWER_KEY_FLAGS_TUNNEL_OAM | \
+		TCA_FLOWER_KEY_FLAGS_TUNNEL_CRIT_OPT)
 
 struct fl_flow_key {
 	struct flow_dissector_key_meta meta;
@@ -745,10 +745,10 @@ static const struct nla_policy fl_policy[TCA_FLOWER_MAX + 1] = {
 	[TCA_FLOWER_KEY_SPI_MASK]	= { .type = NLA_U32 },
 	[TCA_FLOWER_L2_MISS]		= NLA_POLICY_MAX(NLA_U8, 1),
 	[TCA_FLOWER_KEY_CFM]		= { .type = NLA_NESTED },
-	[TCA_FLOWER_KEY_ENC_FLAGS]	= NLA_POLICY_MASK(NLA_U32,
-							  TUNNEL_FLAGS_PRESENT),
-	[TCA_FLOWER_KEY_ENC_FLAGS_MASK]	= NLA_POLICY_MASK(NLA_U32,
-							  TUNNEL_FLAGS_PRESENT),
+	[TCA_FLOWER_KEY_ENC_FLAGS]	= NLA_POLICY_MASK(NLA_BE32,
+							  TCA_FLOWER_KEY_ENC_FLAGS_POLICY_MASK),
+	[TCA_FLOWER_KEY_ENC_FLAGS_MASK]	= NLA_POLICY_MASK(NLA_BE32,
+							  TCA_FLOWER_KEY_ENC_FLAGS_POLICY_MASK),
 };
 
 static const struct nla_policy
@@ -1866,21 +1866,6 @@ static int fl_set_key_cfm(struct nlattr **tb,
 	return 0;
 }
 
-static int fl_set_key_enc_flags(struct nlattr **tb, u32 *flags_key,
-				u32 *flags_mask, struct netlink_ext_ack *extack)
-{
-	/* mask is mandatory for flags */
-	if (NL_REQ_ATTR_CHECK(extack, NULL, tb, TCA_FLOWER_KEY_ENC_FLAGS_MASK)) {
-		NL_SET_ERR_MSG(extack, "missing enc_flags mask");
-		return -EINVAL;
-	}
-
-	*flags_key = nla_get_u32(tb[TCA_FLOWER_KEY_ENC_FLAGS]);
-	*flags_mask = nla_get_u32(tb[TCA_FLOWER_KEY_ENC_FLAGS_MASK]);
-
-	return 0;
-}
-
 static int fl_set_key(struct net *net, struct nlattr **tb,
 		      struct fl_flow_key *key, struct fl_flow_key *mask,
 		      struct netlink_ext_ack *extack)
@@ -2123,8 +2108,8 @@ static int fl_set_key(struct net *net, struct nlattr **tb,
 	}
 
 	if (tb[TCA_FLOWER_KEY_ENC_FLAGS])
-		ret = fl_set_key_enc_flags(tb, &key->enc_flags.flags,
-					   &mask->enc_flags.flags, extack);
+		ret = fl_set_key_flags(tb, true, &key->enc_control.flags,
+				       &mask->enc_control.flags, extack);
 
 	return ret;
 }
@@ -3381,22 +3366,6 @@ static int fl_dump_key_cfm(struct sk_buff *skb,
 	return err;
 }
 
-static int fl_dump_key_enc_flags(struct sk_buff *skb,
-				 struct flow_dissector_key_enc_flags *key,
-				 struct flow_dissector_key_enc_flags *mask)
-{
-	if (!memchr_inv(mask, 0, sizeof(*mask)))
-		return 0;
-
-	if (nla_put_u32(skb, TCA_FLOWER_KEY_ENC_FLAGS, key->flags))
-		return -EMSGSIZE;
-
-	if (nla_put_u32(skb, TCA_FLOWER_KEY_ENC_FLAGS_MASK, mask->flags))
-		return -EMSGSIZE;
-
-	return 0;
-}
-
 static int fl_dump_key_options(struct sk_buff *skb, int enc_opt_type,
 			       struct flow_dissector_key_enc_opts *enc_opts)
 {
@@ -3699,7 +3668,8 @@ static int fl_dump_key(struct sk_buff *skb, struct net *net,
 	if (fl_dump_key_cfm(skb, &key->cfm, &mask->cfm))
 		goto nla_put_failure;
 
-	if (fl_dump_key_enc_flags(skb, &key->enc_flags, &mask->enc_flags))
+	if (fl_dump_key_flags(skb, true, key->enc_control.flags,
+			      mask->enc_control.flags))
 		goto nla_put_failure;
 
 	return 0;