Re: [PATCH net-next 2/3] net/sched: cls_flower: Add support for matching on flags

On 12/6/2016 2:40 PM, Jiri Pirko wrote:

Tue, Dec 06, 2016 at 01:32:58PM CET, ogerlitz@mellanox.com wrote:

quoted

Add UAPI to provide set of flags for matching, where the flags
provided from user-space are mapped to flow-dissector flags.

The 1st flag allows to match on whether the packet is an
IP fragment and corresponds to the FLOW_DIS_IS_FRAGMENT flag.

Signed-off-by: Or Gerlitz <redacted>
Reviewed-by: Paul Blakey <redacted>
---
include/uapi/linux/pkt_cls.h |  7 ++++
net/sched/cls_flower.c       | 83 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 90 insertions(+)

diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h
index 86786d4..f114277 100644
--- a/include/uapi/linux/pkt_cls.h
+++ b/include/uapi/linux/pkt_cls.h

@@ -457,11 +457,18 @@ enum {

	TCA_FLOWER_KEY_ENC_UDP_SRC_PORT_MASK,	/* be16 */
	TCA_FLOWER_KEY_ENC_UDP_DST_PORT,	/* be16 */
	TCA_FLOWER_KEY_ENC_UDP_DST_PORT_MASK,	/* be16 */
+
+	TCA_FLOWER_KEY_FLAGS,		/* be32 */
+	TCA_FLOWER_KEY_FLAGS_MASK,	/* be32 */
	__TCA_FLOWER_MAX,
};

#define TCA_FLOWER_MAX (__TCA_FLOWER_MAX - 1)

+enum {
+	TCA_FLOWER_KEY_FLAGS_IS_FRAGMENT = BIT(0),
+};
+
/* Match-all classifier */

enum {

diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index c5cea78..d9f4124 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c

@@ -383,6 +383,8 @@ static const struct nla_policy fl_policy[TCA_FLOWER_MAX + 1] = {

	[TCA_FLOWER_KEY_ENC_UDP_SRC_PORT_MASK]	= { .type = NLA_U16 },
	[TCA_FLOWER_KEY_ENC_UDP_DST_PORT]	= { .type = NLA_U16 },
	[TCA_FLOWER_KEY_ENC_UDP_DST_PORT_MASK]	= { .type = NLA_U16 },
+	[TCA_FLOWER_KEY_FLAGS]		= { .type = NLA_U32 },
+	[TCA_FLOWER_KEY_FLAGS_MASK]	= { .type = NLA_U32 },
};

static void fl_set_key_val(struct nlattr **tb,

@@ -417,6 +419,40 @@ static void fl_set_key_vlan(struct nlattr **tb,

	}
}

+static void set_flags(u32 flower_key, u32 flower_mask,

Use some prefix for helpers like this, or at least __

okay, will use fl_set_key_flags here

quoted

+		      u32 *dissector_key, u32 *dissector_mask,
+		      u32 flower_flag_bit, u32 dissector_flag_bit)
+{
+	if (flower_mask & flower_flag_bit) {
+		*dissector_mask |= dissector_flag_bit;
+		if (flower_key & flower_flag_bit)
+			*dissector_key |= dissector_flag_bit;
+	}
+}
+
+static void fl_set_key_flags(struct nlattr **tb,
+			     u32 *flags_key,
+			     u32 *flags_mask)
+{
+	u32 key, mask;
+
+	if (!tb[TCA_FLOWER_KEY_FLAGS])
+		return;
+
+	key = be32_to_cpu(nla_get_u32(tb[TCA_FLOWER_KEY_FLAGS]));
+
+	if (!tb[TCA_FLOWER_KEY_FLAGS_MASK])
+		mask = ~0;
+	else
+		mask = be32_to_cpu(nla_get_u32(tb[TCA_FLOWER_KEY_FLAGS_MASK]));
+
+	*flags_key  = 0;
+	*flags_mask = 0;
+
+	set_flags(key, mask, flags_key, flags_mask,
+		  TCA_FLOWER_KEY_FLAGS_IS_FRAGMENT, FLOW_DIS_IS_FRAGMENT);
+}
+
static int fl_set_key(struct net *net, struct nlattr **tb,
		      struct fl_flow_key *key, struct fl_flow_key *mask)
{

@@ -543,6 +579,8 @@ static int fl_set_key(struct net *net, struct nlattr **tb,

		       &mask->enc_tp.dst, TCA_FLOWER_KEY_ENC_UDP_DST_PORT_MASK,
		       sizeof(key->enc_tp.dst));

+	fl_set_key_flags(tb, &key->control.flags, &mask->control.flags);
+
	return 0;
}

@@ -877,6 +915,48 @@ static int fl_dump_key_vlan(struct sk_buff *skb,

	return 0;
}

+static void get_flags(u32 dissector_key, u32 dissector_mask,

Same here.

and fl_get_key_flags here

quoted

+		      u32 *flower_key, u32 *flower_mask,
+		      u32 flower_flag_bit, u32 dissector_flag_bit)
+{
+	if (dissector_mask & dissector_flag_bit) {
+		*flower_mask |= flower_flag_bit;
+		if (dissector_key & dissector_flag_bit)
+			*flower_key |= flower_flag_bit;
+	}
+}
+
+static int fl_dump_key_flags(struct sk_buff *skb,
+			     u32 flags_key,
+			     u32 flags_mask)

over-wrapped :)

okay,

quoted

+{
+	u32 key, mask;
+	__be32 _key, _mask;
+	int err;
+
+	if (!memchr_inv(&flags_mask, 0, sizeof(flags_mask)))
+		return 0;
+
+	key  = 0;

             ^ remove the extra space

okay

quoted

+	mask = 0;
+
+	get_flags(flags_key, flags_mask, &key, &mask,
+		  TCA_FLOWER_KEY_FLAGS_IS_FRAGMENT, FLOW_DIS_IS_FRAGMENT);
+
+	_key  = cpu_to_be32(key);

              ^ remove the extra space

NP

quoted

+	_mask = cpu_to_be32(mask);
+
+	err = nla_put(skb, TCA_FLOWER_KEY_FLAGS, 4, &_key);
+	if (err)
+		return err;
+
+	err = nla_put(skb, TCA_FLOWER_KEY_FLAGS_MASK, 4, &_mask);

Just return nla_put...

sure