[PATCH net-next v4 1/6] net: dcb: add new pcp selector to app object

Daniel Machon
2022-10-28T09:55:13Z

Add new PCP selector for the 8021Qaz APP managed object.

As the PCP selector is not part of the 8021Qaz standard, a new non-std
extension attribute DCB_ATTR_DCB_APP has been introduced. Also two
helper functions to translate between selector and app attribute type
has been added. The new selector has been given a value of 255, to
minimize the risk of future overlap of std- and non-std attributes.

The new DCB_ATTR_DCB_APP is sent alongside the ieee std attribute in the
app table. This means that the dcb_app struct can now both contain std-
and non-std app attributes. Currently there is no overlap between the
selector values of the two attributes.

The purpose of adding the PCP selector, is to be able to offload
PCP-based queue classification to the 8021Q Priority Code Point table,
see 6.9.3 of IEEE Std 802.1Q-2018.

PCP and DEI is encoded in the protocol field as 8*dei+pcp, so that a
mapping of PCP 2 and DEI 1 to priority 3 is encoded as {255, 10, 3}.

Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
---
include/uapi/linux/dcbnl.h | 6 ++++
net/dcb/dcbnl.c | 73 +++++++++++++++++++++++++++++++++++---
2 files changed, 75 insertions(+), 4 deletions(-)

diff --git a/include/uapi/linux/dcbnl.h b/include/uapi/linux/dcbnl.h
index a791a94013a6..dc7ef96207ca 100644
--- a/include/uapi/linux/dcbnl.h
+++ b/include/uapi/linux/dcbnl.h
@@ -218,6 +218,9 @@ struct cee_pfc {
#define IEEE_8021QAZ_APP_SEL_ANY 4
#define IEEE_8021QAZ_APP_SEL_DSCP 5

+/* Non-std selector values */
+#define DCB_APP_SEL_PCP 255
+
/* This structure contains the IEEE 802.1Qaz APP managed object. This
* object is also used for the CEE std as well.
*
@@ -247,6 +250,8 @@ struct dcb_app {
__u16 protocol;
};

+#define IEEE_8021QAZ_APP_SEL_MAX 255
+
/**
* struct dcb_peer_app_info - APP feature information sent by the peer
*
@@ -425,6 +430,7 @@ enum ieee_attrs {
enum ieee_attrs_app {
DCB_ATTR_IEEE_APP_UNSPEC,
DCB_ATTR_IEEE_APP,
+ DCB_ATTR_DCB_APP,
__DCB_ATTR_IEEE_APP_MAX
};
#define DCB_ATTR_IEEE_APP_MAX (__DCB_ATTR_IEEE_APP_MAX - 1)
diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
index dc4fb699b56c..68e033a459af 100644
--- a/net/dcb/dcbnl.c
+++ b/net/dcb/dcbnl.c
@@ -179,6 +179,57 @@ static const struct nla_policy dcbnl_featcfg_nest[DCB_FEATCFG_ATTR_MAX + 1] = {
static LIST_HEAD(dcb_app_list);
static DEFINE_SPINLOCK(dcb_lock);

+static enum ieee_attrs_app dcbnl_app_attr_type_get(u8 selector)
+{
+ switch (selector) {
+ case IEEE_8021QAZ_APP_SEL_ETHERTYPE:
+ case IEEE_8021QAZ_APP_SEL_STREAM:
+ case IEEE_8021QAZ_APP_SEL_DGRAM:
+ case IEEE_8021QAZ_APP_SEL_ANY:
+ case IEEE_8021QAZ_APP_SEL_DSCP:
+ return DCB_ATTR_IEEE_APP;
+ case DCB_APP_SEL_PCP:
+ return DCB_ATTR_DCB_APP;
+ default:
+ return DCB_ATTR_IEEE_APP_UNSPEC;
+ }
+}
+
+static bool dcbnl_app_attr_type_validate(enum ieee_attrs_app type)
+{
+ switch (type) {
+ case DCB_ATTR_IEEE_APP:
+ case DCB_ATTR_DCB_APP:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static bool dcbnl_app_selector_validate(enum ieee_attrs_app type, u32 selector)
+{
+ switch (selector) {
+ case IEEE_8021QAZ_APP_SEL_ETHERTYPE:
+ case IEEE_8021QAZ_APP_SEL_STREAM:
+ case IEEE_8021QAZ_APP_SEL_DGRAM:
+ case IEEE_8021QAZ_APP_SEL_ANY:
+ case IEEE_8021QAZ_APP_SEL_DSCP:
+ /* IEEE std selectors in IEEE std attribute */
+ if (type == DCB_ATTR_IEEE_APP)
+ return true;
+ else
+ return false;
+ case DCB_APP_SEL_PCP:
+ /* Non-std selectors in non-std attribute */
+ if (type == DCB_ATTR_DCB_APP)
+ return true;
+ else
+ return false;
+ default:
+ return false;
+ }
+}
+
static struct sk_buff *dcbnl_newmsg(int type, u8 cmd, u32 port, u32 seq,
u32 flags, struct nlmsghdr **nlhp)
{
@@ -1116,8 +1167,9 @@ static int dcbnl_ieee_fill(struct sk_buff *skb, struct net_device *netdev)
spin_lock_bh(&dcb_lock);
list_for_each_entry(itr, &dcb_app_list, list) {
if (itr->ifindex == netdev->ifindex) {
- err = nla_put(skb, DCB_ATTR_IEEE_APP, sizeof(itr->app),
- &itr->app);
+ enum ieee_attrs_app type =
+ dcbnl_app_attr_type_get(itr->app.selector);
+ err = nla_put(skb, type, sizeof(itr->app), &itr->app);
if (err) {
spin_unlock_bh(&dcb_lock);
return -EMSGSIZE;
@@ -1493,9 +1545,10 @@ static int dcbnl_ieee_set(struct net_device *netdev, struct nlmsghdr *nlh,
int rem;

nla_for_each_nested(attr, ieee[DCB_ATTR_IEEE_APP_TABLE], rem) {
+ enum ieee_attrs_app type = nla_type(attr);
struct dcb_app *app_data;

- if (nla_type(attr) != DCB_ATTR_IEEE_APP)
+ if (!dcbnl_app_attr_type_validate(type))
continue;

if (nla_len(attr) < sizeof(struct dcb_app)) {
@@ -1504,6 +1557,11 @@ static int dcbnl_ieee_set(struct net_device *netdev, struct nlmsghdr *nlh,
}

app_data = nla_data(attr);
+
+ if (!dcbnl_app_selector_validate(type,
+ app_data->selector))
+ return -EINVAL;
+
if (ops->ieee_setapp)
err = ops->ieee_setapp(netdev, app_data);
else
@@ -1554,11 +1612,18 @@ static int dcbnl_ieee_del(struct net_device *netdev, struct nlmsghdr *nlh,
int rem;

nla_for_each_nested(attr, ieee[DCB_ATTR_IEEE_APP_TABLE], rem) {
+ enum ieee_attrs_app type = nla_type(attr);
struct dcb_app *app_data;

- if (nla_type(attr) != DCB_ATTR_IEEE_APP)
+ if (!dcbnl_app_attr_type_validate(type))
continue;
+
app_data = nla_data(attr);
+
+ if (!dcbnl_app_selector_validate(type,
+ app_data->selector))
+ return -EINVAL;
+
if (ops->ieee_delapp)
err = ops->ieee_delapp(netdev, app_data);
else
--
2.34.1