cfg80211: add support to probe unexercised mesh link

Adding support to allow mesh HWMP to measure link metrics on unexercised
direct mesh path by sending some data frames to other mesh points which
are not currently selected as a primary traffic path but only 1 hop away.
The absence of the primary path to the chosen node makes it necessary to
apply some form of marking on a chosen packet stream so that the packets
can be properly steered to the selected node for testing, and not by the
regular mesh path lookup.

Tested-by: Pradeep Kumar Chitrapu <pradeepc@codeaurora.org>
Signed-off-by: Rajkumar Manoharan <rmanohar@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

3 files changed, 79 insertions, 0 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 5dfc4dba9e56..3aecdd3d5b07 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -13404,6 +13404,47 @@ static int nl80211_update_owe_info(struct sk_buff *skb, struct genl_info *info)
 	return rdev_update_owe_info(rdev, dev, &owe_info);
 }
 
+static int nl80211_probe_mesh_link(struct sk_buff *skb, struct genl_info *info)
+{
+	struct cfg80211_registered_device *rdev = info->user_ptr[0];
+	struct net_device *dev = info->user_ptr[1];
+	struct wireless_dev *wdev = dev->ieee80211_ptr;
+	struct station_info sinfo = {};
+	const u8 *buf;
+	size_t len;
+	u8 *dest;
+	int err;
+
+	if (!rdev->ops->probe_mesh_link || !rdev->ops->get_station)
+		return -EOPNOTSUPP;
+
+	if (!info->attrs[NL80211_ATTR_MAC] ||
+	    !info->attrs[NL80211_ATTR_FRAME]) {
+		GENL_SET_ERR_MSG(info, "Frame or MAC missing");
+		return -EINVAL;
+	}
+
+	if (wdev->iftype != NL80211_IFTYPE_MESH_POINT)
+		return -EOPNOTSUPP;
+
+	dest = nla_data(info->attrs[NL80211_ATTR_MAC]);
+	buf = nla_data(info->attrs[NL80211_ATTR_FRAME]);
+	len = nla_len(info->attrs[NL80211_ATTR_FRAME]);
+
+	if (len < sizeof(struct ethhdr))
+		return -EINVAL;
+
+	if (!ether_addr_equal(buf, dest) || is_multicast_ether_addr(buf) ||
+	    !ether_addr_equal(buf + ETH_ALEN, dev->dev_addr))
+		return -EINVAL;
+
+	err = rdev_get_station(rdev, dev, dest, &sinfo);
+	if (err)
+		return err;
+
+	return rdev_probe_mesh_link(rdev, dev, dest, buf, len);
+}
+
 #define NL80211_FLAG_NEED_WIPHY		0x01
 #define NL80211_FLAG_NEED_NETDEV	0x02
 #define NL80211_FLAG_NEED_RTNL		0x04
@@ -14241,6 +14282,13 @@ static const struct genl_ops nl80211_ops[] = {
 		.internal_flags = NL80211_FLAG_NEED_NETDEV_UP |
 				  NL80211_FLAG_NEED_RTNL,
 	},
+	{
+		.cmd = NL80211_CMD_PROBE_MESH_LINK,
+		.doit = nl80211_probe_mesh_link,
+		.flags = GENL_UNS_ADMIN_PERM,
+		.internal_flags = NL80211_FLAG_NEED_NETDEV_UP |
+				  NL80211_FLAG_NEED_RTNL,
+	},
 };
 
 static struct genl_family nl80211_fam __ro_after_init = {
diff --git a/net/wireless/rdev-ops.h b/net/wireless/rdev-ops.h
index 18437a9deb54..e853a4fe6f97 100644
--- a/net/wireless/rdev-ops.h
+++ b/net/wireless/rdev-ops.h
@@ -1286,4 +1286,17 @@ static inline int rdev_update_owe_info(struct cfg80211_registered_device *rdev,
 	return ret;
 }
 
+static inline int
+rdev_probe_mesh_link(struct cfg80211_registered_device *rdev,
+		     struct net_device *dev, const u8 *dest,
+		     const void *buf, size_t len)
+{
+	int ret;
+
+	trace_rdev_probe_mesh_link(&rdev->wiphy, dev, dest, buf, len);
+	ret = rdev->ops->probe_mesh_link(&rdev->wiphy, dev, buf, len);
+	trace_rdev_return_int(&rdev->wiphy, ret);
+	return ret;
+}
+
 #endif /* __CFG80211_RDEV_OPS */
diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index 488ef2ce8231..2abfff925aac 100644
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -3421,6 +3421,24 @@ TRACE_EVENT(cfg80211_update_owe_info_event,
 		      WIPHY_PR_ARG, NETDEV_PR_ARG, MAC_PR_ARG(peer))
 );
 
+TRACE_EVENT(rdev_probe_mesh_link,
+	TP_PROTO(struct wiphy *wiphy, struct net_device *netdev,
+		 const u8 *dest, const u8 *buf, size_t len),
+	TP_ARGS(wiphy, netdev, dest, buf, len),
+	TP_STRUCT__entry(
+		WIPHY_ENTRY
+		NETDEV_ENTRY
+		MAC_ENTRY(dest)
+	),
+	TP_fast_assign(
+		WIPHY_ASSIGN;
+		NETDEV_ASSIGN;
+		MAC_ASSIGN(dest, dest);
+	),
+	TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT ", " MAC_PR_FMT,
+		  WIPHY_PR_ARG, NETDEV_PR_ARG, MAC_PR_ARG(dest))
+);
+
 #endif /* !__RDEV_OPS_TRACE || TRACE_HEADER_MULTI_READ */
 
 #undef TRACE_INCLUDE_PATH