DCB: Add interface to query # of TCs supported by device

Adds interface for Data Center Bridging (DCB) to query (and set if
supported) the number of traffic classes currently supported by the
device for the two (DCB) features: priority groups (PG) and priority
flow control (PFC).

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 132 insertions, 0 deletions

diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
index de61d64d102..5ff7e3c0c17 100644
--- a/net/dcb/dcbnl.c
+++ b/net/dcb/dcbnl.c
@@ -120,6 +120,13 @@ static struct nla_policy dcbnl_cap_nest[DCB_CAP_ATTR_MAX + 1] = {
 	[DCB_CAP_ATTR_BCN]     = {.type = NLA_U8},
 };
 
+/* DCB capabilities nested attributes. */
+static struct nla_policy dcbnl_numtcs_nest[DCB_NUMTCS_ATTR_MAX + 1] = {
+	[DCB_NUMTCS_ATTR_ALL]     = {.type = NLA_FLAG},
+	[DCB_NUMTCS_ATTR_PG]      = {.type = NLA_U8},
+	[DCB_NUMTCS_ATTR_PFC]     = {.type = NLA_U8},
+};
+
 /* standard netlink reply call */
 static int dcbnl_reply(u8 value, u8 event, u8 cmd, u8 attr, u32 pid,
                        u32 seq, u16 flags)
@@ -347,6 +354,123 @@ err_out:
 	return -EINVAL;
 }
 
+static int dcbnl_getnumtcs(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_NUMTCS_ATTR_MAX + 1], *nest;
+	u8 value;
+	int ret = -EINVAL;
+	int i;
+	int getall = 0;
+
+	if (!tb[DCB_ATTR_NUMTCS] || !netdev->dcbnl_ops->getnumtcs)
+		return ret;
+
+	ret = nla_parse_nested(data, DCB_NUMTCS_ATTR_MAX, tb[DCB_ATTR_NUMTCS],
+	                       dcbnl_numtcs_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_GNUMTCS;
+
+	nest = nla_nest_start(dcbnl_skb, DCB_ATTR_NUMTCS);
+	if (!nest) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	if (data[DCB_NUMTCS_ATTR_ALL])
+		getall = 1;
+
+	for (i = DCB_NUMTCS_ATTR_ALL+1; i <= DCB_NUMTCS_ATTR_MAX; i++) {
+		if (!getall && !data[i])
+			continue;
+
+		ret = netdev->dcbnl_ops->getnumtcs(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;
+	}
+
+	return 0;
+nlmsg_failure:
+err:
+	kfree(dcbnl_skb);
+err_out:
+	return ret;
+}
+
+static int dcbnl_setnumtcs(struct net_device *netdev, struct nlattr **tb,
+                           u32 pid, u32 seq, u16 flags)
+{
+	struct nlattr *data[DCB_NUMTCS_ATTR_MAX + 1];
+	int ret = -EINVAL;
+	u8 value;
+	int i;
+
+	if (!tb[DCB_ATTR_NUMTCS] || !netdev->dcbnl_ops->setstate)
+		return ret;
+
+	ret = nla_parse_nested(data, DCB_NUMTCS_ATTR_MAX, tb[DCB_ATTR_NUMTCS],
+	                       dcbnl_numtcs_nest);
+
+	if (ret) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	for (i = DCB_NUMTCS_ATTR_ALL+1; i <= DCB_NUMTCS_ATTR_MAX; i++) {
+		if (data[i] == NULL)
+			continue;
+
+		value = nla_get_u8(data[i]);
+
+		ret = netdev->dcbnl_ops->setnumtcs(netdev, i, value);
+
+		if (ret)
+			goto operr;
+	}
+
+operr:
+	ret = dcbnl_reply(!!ret, RTM_SETDCB, DCB_CMD_SNUMTCS,
+	                  DCB_ATTR_NUMTCS, pid, seq, flags);
+
+err:
+	return ret;
+}
+
 static int __dcbnl_pg_getcfg(struct net_device *netdev, struct nlattr **tb,
                              u32 pid, u32 seq, u16 flags, int dir)
 {
@@ -757,6 +881,14 @@ static int dcb_doit(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 		ret = dcbnl_getcap(netdev, tb, pid, nlh->nlmsg_seq,
 		                   nlh->nlmsg_flags);
 		goto out;
+	case DCB_CMD_GNUMTCS:
+		ret = dcbnl_getnumtcs(netdev, tb, pid, nlh->nlmsg_seq,
+		                      nlh->nlmsg_flags);
+		goto out;
+	case DCB_CMD_SNUMTCS:
+		ret = dcbnl_setnumtcs(netdev, tb, pid, nlh->nlmsg_seq,
+		                      nlh->nlmsg_flags);
+		goto out;
 	default:
 		goto errout;
 	}