dcbnl: adding DCBX feature flags get-set

Adding a pair of set-get routines to dcbnl for setting the negotiation
flags of the various DCB features. Conforms to the CEE flavor of DCBX
The user sets these flags (enable, advertise, willing) for each feature
to be used by the DCBX engine. The 'get' routine returns which of the
features is enabled after the negotiation.

This patch is dependent on the following patches:
[net-next-2.6 PATCH 1/3] dcbnl: add support for ieee8021Qaz attributes
[net-next-2.6 PATCH 2/3] dcbnl: add appliction tlv handlers
[net-next-2.6 PATCH 3/3] net_dcb: add application notifiers

Signed-off-by: Shmulik Ravid <shmulikr@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
index 8f83ad8..075af0a 100644
--- a/net/dcb/dcbnl.c
+++ b/net/dcb/dcbnl.c
@@ -69,6 +69,7 @@
 	[DCB_ATTR_APP]         = {.type = NLA_NESTED},
 	[DCB_ATTR_IEEE]	       = {.type = NLA_NESTED},
 	[DCB_ATTR_DCBX]        = {.type = NLA_U8},
+	[DCB_ATTR_FEATCFG]     = {.type = NLA_NESTED},
 };
 
 /* DCB priority flow control to User Priority nested attributes */
@@ -182,6 +183,14 @@
 	[DCB_ATTR_IEEE_APP]	    = {.len = sizeof(struct dcb_app)},
 };
 
+/* DCB number of traffic classes nested attributes. */
+static const struct nla_policy dcbnl_featcfg_nest[DCB_FEATCFG_ATTR_MAX + 1] = {
+	[DCB_FEATCFG_ATTR_ALL]      = {.type = NLA_FLAG},
+	[DCB_FEATCFG_ATTR_PG]       = {.type = NLA_U8},
+	[DCB_FEATCFG_ATTR_PFC]      = {.type = NLA_U8},
+	[DCB_FEATCFG_ATTR_APP]      = {.type = NLA_U8},
+};
+
 static LIST_HEAD(dcb_app_list);
 static DEFINE_SPINLOCK(dcb_lock);
 
@@ -1306,6 +1315,122 @@
 	return ret;
 }
 
+static int dcbnl_getfeatcfg(struct net_device *netdev, struct nlattr **tb,
+			    u32 pid, u32 seq, u16 flags)
+{
+	struct sk_buff *dcbnl_skb;
+	struct nlmsghdr *nlh;
+	struct dcbmsg *dcb;
+	struct nlattr *data[DCB_FEATCFG_ATTR_MAX + 1], *nest;
+	u8 value;
+	int ret = -EINVAL;
+	int i;
+	int getall = 0;
+
+	if (!tb[DCB_ATTR_FEATCFG] || !netdev->dcbnl_ops->getfeatcfg)
+		return ret;
+
+	ret = nla_parse_nested(data, DCB_FEATCFG_ATTR_MAX, tb[DCB_ATTR_FEATCFG],
+			       dcbnl_featcfg_nest);
+	if (ret) {
+		ret = -EINVAL;
+		goto err_out;
+	}
+
+	dcbnl_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!dcbnl_skb) {
+		ret = -EINVAL;
+		goto err_out;
+	}
+
+	nlh = NLMSG_NEW(dcbnl_skb, pid, seq, RTM_GETDCB, sizeof(*dcb), flags);
+
+	dcb = NLMSG_DATA(nlh);
+	dcb->dcb_family = AF_UNSPEC;
+	dcb->cmd = DCB_CMD_GFEATCFG;
+
+	nest = nla_nest_start(dcbnl_skb, DCB_ATTR_FEATCFG);
+	if (!nest) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	if (data[DCB_FEATCFG_ATTR_ALL])
+		getall = 1;
+
+	for (i = DCB_FEATCFG_ATTR_ALL+1; i <= DCB_FEATCFG_ATTR_MAX; i++) {
+		if (!getall && !data[i])
+			continue;
+
+		ret = netdev->dcbnl_ops->getfeatcfg(netdev, i, &value);
+		if (!ret) {
+			ret = nla_put_u8(dcbnl_skb, i, value);
+
+			if (ret) {
+				nla_nest_cancel(dcbnl_skb, nest);
+				ret = -EINVAL;
+				goto err;
+			}
+		} else
+			goto err;
+	}
+	nla_nest_end(dcbnl_skb, nest);
+
+	nlmsg_end(dcbnl_skb, nlh);
+
+	ret = rtnl_unicast(dcbnl_skb, &init_net, pid);
+	if (ret) {
+		ret = -EINVAL;
+		goto err_out;
+	}
+
+	return 0;
+nlmsg_failure:
+err:
+	kfree_skb(dcbnl_skb);
+err_out:
+	return ret;
+}
+
+static int dcbnl_setfeatcfg(struct net_device *netdev, struct nlattr **tb,
+			    u32 pid, u32 seq, u16 flags)
+{
+	struct nlattr *data[DCB_FEATCFG_ATTR_MAX + 1];
+	int ret = -EINVAL;
+	u8 value;
+	int i;
+
+	if (!tb[DCB_ATTR_FEATCFG] || !netdev->dcbnl_ops->setfeatcfg)
+		return ret;
+
+	ret = nla_parse_nested(data, DCB_FEATCFG_ATTR_MAX, tb[DCB_ATTR_FEATCFG],
+			       dcbnl_featcfg_nest);
+
+	if (ret) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	for (i = DCB_FEATCFG_ATTR_ALL+1; i <= DCB_FEATCFG_ATTR_MAX; i++) {
+		if (data[i] == NULL)
+			continue;
+
+		value = nla_get_u8(data[i]);
+
+		ret = netdev->dcbnl_ops->setfeatcfg(netdev, i, value);
+
+		if (ret)
+			goto operr;
+	}
+
+operr:
+	ret = dcbnl_reply(!!ret, RTM_SETDCB, DCB_CMD_SFEATCFG,
+			  DCB_ATTR_FEATCFG, pid, seq, flags);
+
+err:
+	return ret;
+}
+
 static int dcb_doit(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 {
 	struct net *net = sock_net(skb->sk);
@@ -1427,6 +1552,14 @@
 		ret = dcbnl_setdcbx(netdev, tb, pid, nlh->nlmsg_seq,
 				    nlh->nlmsg_flags);
 		goto out;
+	case DCB_CMD_GFEATCFG:
+		ret = dcbnl_getfeatcfg(netdev, tb, pid, nlh->nlmsg_seq,
+				       nlh->nlmsg_flags);
+		goto out;
+	case DCB_CMD_SFEATCFG:
+		ret = dcbnl_setfeatcfg(netdev, tb, pid, nlh->nlmsg_seq,
+				       nlh->nlmsg_flags);
+		goto out;
 	default:
 		goto errout;
 	}