DCB: Add interface to query for the DCB capabilities of an device.

Adds to the netlink interface for Data Center Bridging (DCB), allowing
the DCB capabilities supported by a device to be queried.

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, 82 insertions, 0 deletions

diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
index 516e8be83d72..de61d64d102d 100644
--- a/net/dcb/dcbnl.c
+++ b/net/dcb/dcbnl.c
@@ -61,6 +61,7 @@ static struct nla_policy dcbnl_rtnl_policy[DCB_ATTR_MAX + 1] = {
         [DCB_ATTR_PG_CFG]    = {.type = NLA_NESTED},
         [DCB_ATTR_SET_ALL]   = {.type = NLA_U8},
         [DCB_ATTR_PERM_HWADDR] = {.type = NLA_FLAG},
+        [DCB_ATTR_CAP]       = {.type = NLA_NESTED},
 };
 
 /* DCB priority flow control to User Priority nested attributes */
@@ -107,6 +108,17 @@ static struct nla_policy dcbnl_tc_param_nest[DCB_TC_ATTR_PARAM_MAX + 1] = {
         [DCB_TC_ATTR_PARAM_ALL]             = {.type = NLA_FLAG},
 };
 
+/* DCB capabilities nested attributes. */
+static struct nla_policy dcbnl_cap_nest[DCB_CAP_ATTR_MAX + 1] = {
+        [DCB_CAP_ATTR_ALL]     = {.type = NLA_FLAG},
+        [DCB_CAP_ATTR_PG]      = {.type = NLA_U8},
+        [DCB_CAP_ATTR_PFC]     = {.type = NLA_U8},
+        [DCB_CAP_ATTR_UP2TC]   = {.type = NLA_U8},
+        [DCB_CAP_ATTR_PG_TCS]  = {.type = NLA_U8},
+        [DCB_CAP_ATTR_PFC_TCS] = {.type = NLA_U8},
+        [DCB_CAP_ATTR_GSP]     = {.type = NLA_U8},
+        [DCB_CAP_ATTR_BCN]     = {.type = NLA_U8},
+};
 
 /* standard netlink reply call */
 static int dcbnl_reply(u8 value, u8 event, u8 cmd, u8 attr, u32 pid,
@@ -269,6 +281,72 @@ err_out:
         return -EINVAL;
 }
 
+static int dcbnl_getcap(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_CAP_ATTR_MAX + 1], *nest;
+        u8 value;
+        int ret = -EINVAL;
+        int i;
+        int getall = 0;
+
+        if (!tb[DCB_ATTR_CAP] || !netdev->dcbnl_ops->getcap)
+                return ret;
+
+        ret = nla_parse_nested(data, DCB_CAP_ATTR_MAX, tb[DCB_ATTR_CAP],
+                               dcbnl_cap_nest);
+        if (ret)
+                goto err_out;
+
+        dcbnl_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+        if (!dcbnl_skb)
+                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_GCAP;
+
+        nest = nla_nest_start(dcbnl_skb, DCB_ATTR_CAP);
+        if (!nest)
+                goto err;
+
+        if (data[DCB_CAP_ATTR_ALL])
+                getall = 1;
+
+        for (i = DCB_CAP_ATTR_ALL+1; i <= DCB_CAP_ATTR_MAX; i++) {
+                if (!getall && !data[i])
+                        continue;
+
+                if (!netdev->dcbnl_ops->getcap(netdev, i, &value)) {
+                        ret = nla_put_u8(dcbnl_skb, i, value);
+
+                        if (ret) {
+                                nla_nest_cancel(dcbnl_skb, nest);
+                                goto err;
+                        }
+                }
+        }
+        nla_nest_end(dcbnl_skb, nest);
+
+        nlmsg_end(dcbnl_skb, nlh);
+
+        ret = rtnl_unicast(dcbnl_skb, &init_net, pid);
+        if (ret)
+                goto err;
+
+        return 0;
+nlmsg_failure:
+err:
+        kfree(dcbnl_skb);
+err_out:
+        return -EINVAL;
+}
+
 static int __dcbnl_pg_getcfg(struct net_device *netdev, struct nlattr **tb,
                              u32 pid, u32 seq, u16 flags, int dir)
 {
@@ -675,6 +753,10 @@ static int dcb_doit(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
                 ret = dcbnl_pgrx_setcfg(netdev, tb, pid, nlh->nlmsg_seq,
                                         nlh->nlmsg_flags);
                 goto out;
+        case DCB_CMD_GCAP:
+                ret = dcbnl_getcap(netdev, tb, pid, nlh->nlmsg_seq,
+                                   nlh->nlmsg_flags);
+                goto out;
         default:
                 goto errout;
         }