dcbnl: Aggregated CEE GET operation

The following couple of patches add dcbnl an unsolicited notification of
the the DCB configuration for the CEE flavor of the DCBX protocol. This
is useful when the user-mode DCB client is not responsible for
conducting and resolving the DCBX negotiation (either because the DCBX
stack is embedded in the HW or the negotiation is handled by another
agent in the host), but still needs to get the negotiated parameters.
This functionality already exists for the IEEE flavor of the DCBX
protocol and these patches add it to the older CEE flavor.

The first patch extends the CEE attribute GET operation to include not
only the peer information, but also all the pertinent local
configuration (negotiated parameters). The second patch adds and export
a CEE specific notification routine.
Signed-off-by: Shmulik Ravid <shmulikr@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/dcbnl.h

@@ -333,18 +333,30 @@ enum ieee_attrs_app {
 #define DCB_ATTR_IEEE_APP_MAX (__DCB_ATTR_IEEE_APP_MAX - 1)
 
 /**
- * enum cee_attrs - CEE DCBX get attributes
+ * enum cee_attrs - CEE DCBX get attributes.
  *
  * @DCB_ATTR_CEE_UNSPEC: unspecified
  * @DCB_ATTR_CEE_PEER_PG: peer PG configuration - get only
  * @DCB_ATTR_CEE_PEER_PFC: peer PFC configuration - get only
- * @DCB_ATTR_CEE_PEER_APP: peer APP tlv - get only
+ * @DCB_ATTR_CEE_PEER_APP_TABLE: peer APP tlv - get only
+ * @DCB_ATTR_CEE_TX_PG: TX PG configuration (DCB_CMD_PGTX_GCFG)
+ * @DCB_ATTR_CEE_RX_PG: RX PG configuration (DCB_CMD_PGRX_GCFG)
+ * @DCB_ATTR_CEE_PFC: PFC configuration (DCB_CMD_PFC_GCFG)
+ * @DCB_ATTR_CEE_APP_TABLE: APP configuration (multi DCB_CMD_GAPP)
+ * @DCB_ATTR_CEE_FEAT: DCBX features flags (DCB_CMD_GFEATCFG)
+ *
+ * An aggregated collection of the cee std negotiated parameters.
  */
 enum cee_attrs {
 	DCB_ATTR_CEE_UNSPEC,
 	DCB_ATTR_CEE_PEER_PG,
 	DCB_ATTR_CEE_PEER_PFC,
 	DCB_ATTR_CEE_PEER_APP_TABLE,
+	DCB_ATTR_CEE_TX_PG,
+	DCB_ATTR_CEE_RX_PG,
+	DCB_ATTR_CEE_PFC,
+	DCB_ATTR_CEE_APP_TABLE,
+	DCB_ATTR_CEE_FEAT,
 	__DCB_ATTR_CEE_MAX
 };
 #define DCB_ATTR_CEE_MAX (__DCB_ATTR_CEE_MAX - 1)
@@ -357,6 +369,13 @@ enum peer_app_attr {
 };
 #define DCB_ATTR_CEE_PEER_APP_MAX (__DCB_ATTR_CEE_PEER_APP_MAX - 1)
 
+enum cee_attrs_app {
+	DCB_ATTR_CEE_APP_UNSPEC,
+	DCB_ATTR_CEE_APP,
+	__DCB_ATTR_CEE_APP_MAX
+};
+#define DCB_ATTR_CEE_APP_MAX (__DCB_ATTR_CEE_APP_MAX - 1)
+
 /**
  * enum dcbnl_pfc_attrs - DCB Priority Flow Control user priority nested attrs
  *

net/dcb/dcbnl.c

@@ -1642,6 +1642,60 @@ static int dcbnl_setfeatcfg(struct net_device *netdev, struct nlattr **tb,
 	return ret;
 }
 
+static int dcbnl_cee_pg_fill(struct sk_buff *skb, struct net_device *dev,
+			     int dir)
+{
+	u8 pgid, up_map, prio, tc_pct;
+	const struct dcbnl_rtnl_ops *ops = dev->dcbnl_ops;
+	int i = dir ? DCB_ATTR_CEE_TX_PG : DCB_ATTR_CEE_RX_PG;
+	struct nlattr *pg = nla_nest_start(skb, i);
+
+	if (!pg)
+		goto nla_put_failure;
+
+	for (i = DCB_PG_ATTR_TC_0; i <= DCB_PG_ATTR_TC_7; i++) {
+		struct nlattr *tc_nest = nla_nest_start(skb, i);
+
+		if (!tc_nest)
+			goto nla_put_failure;
+
+		pgid = DCB_ATTR_VALUE_UNDEFINED;
+		prio = DCB_ATTR_VALUE_UNDEFINED;
+		tc_pct = DCB_ATTR_VALUE_UNDEFINED;
+		up_map = DCB_ATTR_VALUE_UNDEFINED;
+
+		if (!dir)
+			ops->getpgtccfgrx(dev, i - DCB_PG_ATTR_TC_0,
+					  &prio, &pgid, &tc_pct, &up_map);
+		else
+			ops->getpgtccfgtx(dev, i - DCB_PG_ATTR_TC_0,
+					  &prio, &pgid, &tc_pct, &up_map);
+
+		NLA_PUT_U8(skb, DCB_TC_ATTR_PARAM_PGID, pgid);
+		NLA_PUT_U8(skb, DCB_TC_ATTR_PARAM_UP_MAPPING, up_map);
+		NLA_PUT_U8(skb, DCB_TC_ATTR_PARAM_STRICT_PRIO, prio);
+		NLA_PUT_U8(skb, DCB_TC_ATTR_PARAM_BW_PCT, tc_pct);
+		nla_nest_end(skb, tc_nest);
+	}
+
+	for (i = DCB_PG_ATTR_BW_ID_0; i <= DCB_PG_ATTR_BW_ID_7; i++) {
+		tc_pct = DCB_ATTR_VALUE_UNDEFINED;
+
+		if (!dir)
+			ops->getpgbwgcfgrx(dev, i - DCB_PG_ATTR_BW_ID_0,
+					   &tc_pct);
+		else
+			ops->getpgbwgcfgtx(dev, i - DCB_PG_ATTR_BW_ID_0,
+					   &tc_pct);
+		NLA_PUT_U8(skb, i, tc_pct);
+	}
+	nla_nest_end(skb, pg);
+	return 0;
+
+nla_put_failure:
+	return -EMSGSIZE;
+}
+
 /* Handle CEE DCBX GET commands. */
 static int dcbnl_cee_get(struct net_device *netdev, struct nlattr **tb,
 			 u32 pid, u32 seq, u16 flags)
@@ -1649,9 +1703,11 @@ static int dcbnl_cee_get(struct net_device *netdev, struct nlattr **tb,
 	struct sk_buff *skb;
 	struct nlmsghdr *nlh;
 	struct dcbmsg *dcb;
-	struct nlattr *cee;
+	struct nlattr *cee, *app;
+	struct dcb_app_type *itr;
 	const struct dcbnl_rtnl_ops *ops = netdev->dcbnl_ops;
-	int err;
+	int dcbx, i, err = -EMSGSIZE;
+	u8 value;
 
 	if (!ops)
 		return -EOPNOTSUPP;
@@ -1672,7 +1728,88 @@ static int dcbnl_cee_get(struct net_device *netdev, struct nlattr **tb,
 	if (!cee)
 		goto nla_put_failure;
 
-	/* get peer info if available */
+	/* local pg */
+	if (ops->getpgtccfgtx && ops->getpgbwgcfgtx) {
+		err = dcbnl_cee_pg_fill(skb, netdev, 1);
+		if (err)
+			goto nla_put_failure;
+	}
+
+	if (ops->getpgtccfgrx && ops->getpgbwgcfgrx) {
+		err = dcbnl_cee_pg_fill(skb, netdev, 0);
+		if (err)
+			goto nla_put_failure;
+	}
+
+	/* local pfc */
+	if (ops->getpfccfg) {
+		struct nlattr *pfc_nest = nla_nest_start(skb, DCB_ATTR_CEE_PFC);
+
+		if (!pfc_nest)
+			goto nla_put_failure;
+
+		for (i = DCB_PFC_UP_ATTR_0; i <= DCB_PFC_UP_ATTR_7; i++) {
+			ops->getpfccfg(netdev, i - DCB_PFC_UP_ATTR_0, &value);
+			NLA_PUT_U8(skb, i, value);
+		}
+		nla_nest_end(skb, pfc_nest);
+	}
+
+	/* local app */
+	spin_lock(&dcb_lock);
+	app = nla_nest_start(skb, DCB_ATTR_CEE_APP_TABLE);
+	if (!app)
+		goto nla_put_failure;
+
+	list_for_each_entry(itr, &dcb_app_list, list) {
+		if (strncmp(itr->name, netdev->name, IFNAMSIZ) == 0) {
+			struct nlattr *app_nest = nla_nest_start(skb,
+								 DCB_ATTR_APP);
+			if (!app_nest)
+				goto dcb_unlock;
+
+			err = nla_put_u8(skb, DCB_APP_ATTR_IDTYPE,
+					 itr->app.selector);
+			if (err)
+				goto dcb_unlock;
+
+			err = nla_put_u16(skb, DCB_APP_ATTR_ID,
+					  itr->app.protocol);
+			if (err)
+				goto dcb_unlock;
+
+			err = nla_put_u8(skb, DCB_APP_ATTR_PRIORITY,
+					 itr->app.priority);
+			if (err)
+				goto dcb_unlock;
+
+			nla_nest_end(skb, app_nest);
+		}
+	}
+	nla_nest_end(skb, app);
+
+	if (netdev->dcbnl_ops->getdcbx)
+		dcbx = netdev->dcbnl_ops->getdcbx(netdev);
+	else
+		dcbx = -EOPNOTSUPP;
+
+	spin_unlock(&dcb_lock);
+
+	/* features flags */
+	if (ops->getfeatcfg) {
+		struct nlattr *feat = nla_nest_start(skb, DCB_ATTR_CEE_FEAT);
+		if (!feat)
+			goto nla_put_failure;
+
+		for (i = DCB_FEATCFG_ATTR_ALL + 1; i <= DCB_FEATCFG_ATTR_MAX;
+		     i++)
+			if (!ops->getfeatcfg(netdev, i, &value))
+				NLA_PUT_U8(skb, i, value);
+
+		nla_nest_end(skb, feat);
+	}
+
+	/* peer info if available */
 	if (ops->cee_peer_getpg) {
 		struct cee_pg pg;
 		err = ops->cee_peer_getpg(netdev, &pg);
@@ -1695,16 +1832,24 @@ static int dcbnl_cee_get(struct net_device *netdev, struct nlattr **tb,
 		if (err)
 			goto nla_put_failure;
 	}
-
 	nla_nest_end(skb, cee);
-	nlmsg_end(skb, nlh);
 
+	/* DCBX state */
+	if (dcbx >= 0) {
+		err = nla_put_u8(skb, DCB_ATTR_DCBX, dcbx);
+		if (err)
+			goto nla_put_failure;
+	}
+	nlmsg_end(skb, nlh);
 	return rtnl_unicast(skb, &init_net, pid);
+
+dcb_unlock:
+	spin_unlock(&dcb_lock);
 nla_put_failure:
 	nlmsg_cancel(skb, nlh);
 nlmsg_failure:
-	kfree_skb(skb);
-	return -1;
+	nlmsg_free(skb);
+	return err;
 }
 
 static int dcb_doit(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)