nl80211: add ability to report TX status for control port TX

This adds the necessary capabilities in nl80211 to allow drivers to
assign a cookie to control port TX frames (returned via extack in
the netlink ACK message of the command) and then later report the
frame's status.

Signed-off-by: Markus Theil <markus.theil@tu-ilmenau.de>
Link: https://lore.kernel.org/r/20200508144202.7678-2-markus.theil@tu-ilmenau.de
[use extack cookie instead of explicit message, recombine patches]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

3 files changed, 56 insertions, 11 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 84bfa147769a..7ea764865546 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -13866,6 +13866,7 @@ static int nl80211_external_auth(struct sk_buff *skb, struct genl_info *info)
 
 static int nl80211_tx_control_port(struct sk_buff *skb, struct genl_info *info)
 {
+	bool dont_wait_for_ack = info->attrs[NL80211_ATTR_DONT_WAIT_FOR_ACK];
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
 	struct net_device *dev = info->user_ptr[1];
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
@@ -13874,6 +13875,7 @@ static int nl80211_tx_control_port(struct sk_buff *skb, struct genl_info *info)
 	u8 *dest;
 	u16 proto;
 	bool noencrypt;
+	u64 cookie = 0;
 	int err;
 
 	if (!wiphy_ext_feature_isset(&rdev->wiphy,
@@ -13918,9 +13920,12 @@ static int nl80211_tx_control_port(struct sk_buff *skb, struct genl_info *info)
 	noencrypt =
 		nla_get_flag(info->attrs[NL80211_ATTR_CONTROL_PORT_NO_ENCRYPT]);
 
-	return rdev_tx_control_port(rdev, dev, buf, len,
-				    dest, cpu_to_be16(proto), noencrypt);
-
+	err = rdev_tx_control_port(rdev, dev, buf, len,
+				   dest, cpu_to_be16(proto), noencrypt,
+				   dont_wait_for_ack ? NULL : &cookie);
+	if (!err && !dont_wait_for_ack)
+		nl_set_extack_cookie_u64(info->extack, cookie);
+	return err;
  out:
 	wdev_unlock(wdev);
 	return err;
@@ -16294,8 +16299,9 @@ int nl80211_send_mgmt(struct cfg80211_registered_device *rdev,
 	return -ENOBUFS;
 }
 
-void cfg80211_mgmt_tx_status(struct wireless_dev *wdev, u64 cookie,
-			     const u8 *buf, size_t len, bool ack, gfp_t gfp)
+static void nl80211_frame_tx_status(struct wireless_dev *wdev, u64 cookie,
+				    const u8 *buf, size_t len, bool ack,
+				    gfp_t gfp, enum nl80211_commands command)
 {
 	struct wiphy *wiphy = wdev->wiphy;
 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
@@ -16303,13 +16309,16 @@ void cfg80211_mgmt_tx_status(struct wireless_dev *wdev, u64 cookie,
 	struct sk_buff *msg;
 	void *hdr;
 
-	trace_cfg80211_mgmt_tx_status(wdev, cookie, ack);
+	if (command == NL80211_CMD_FRAME_TX_STATUS)
+		trace_cfg80211_mgmt_tx_status(wdev, cookie, ack);
+	else
+		trace_cfg80211_control_port_tx_status(wdev, cookie, ack);
 
 	msg = nlmsg_new(100 + len, gfp);
 	if (!msg)
 		return;
 
-	hdr = nl80211hdr_put(msg, 0, 0, 0, NL80211_CMD_FRAME_TX_STATUS);
+	hdr = nl80211hdr_put(msg, 0, 0, 0, command);
 	if (!hdr) {
 		nlmsg_free(msg);
 		return;
@@ -16332,9 +16341,25 @@ void cfg80211_mgmt_tx_status(struct wireless_dev *wdev, u64 cookie,
 				NL80211_MCGRP_MLME, gfp);
 	return;
 
- nla_put_failure:
+nla_put_failure:
 	nlmsg_free(msg);
 }
+
+void cfg80211_control_port_tx_status(struct wireless_dev *wdev, u64 cookie,
+				     const u8 *buf, size_t len, bool ack,
+				     gfp_t gfp)
+{
+	nl80211_frame_tx_status(wdev, cookie, buf, len, ack, gfp,
+				NL80211_CMD_CONTROL_PORT_FRAME_TX_STATUS);
+}
+EXPORT_SYMBOL(cfg80211_control_port_tx_status);
+
+void cfg80211_mgmt_tx_status(struct wireless_dev *wdev, u64 cookie,
+			     const u8 *buf, size_t len, bool ack, gfp_t gfp)
+{
+	nl80211_frame_tx_status(wdev, cookie, buf, len, ack, gfp,
+				NL80211_CMD_FRAME_TX_STATUS);
+}
 EXPORT_SYMBOL(cfg80211_mgmt_tx_status);
 
 static int __nl80211_rx_control_port(struct net_device *dev,
diff --git a/net/wireless/rdev-ops.h b/net/wireless/rdev-ops.h
index df5142e86c4f..950d57494168 100644
--- a/net/wireless/rdev-ops.h
+++ b/net/wireless/rdev-ops.h
@@ -748,14 +748,17 @@ static inline int rdev_tx_control_port(struct cfg80211_registered_device *rdev,
 				       struct net_device *dev,
 				       const void *buf, size_t len,
 				       const u8 *dest, __be16 proto,
-				       const bool noencrypt)
+				       const bool noencrypt, u64 *cookie)
 {
 	int ret;
 	trace_rdev_tx_control_port(&rdev->wiphy, dev, buf, len,
 				   dest, proto, noencrypt);
 	ret = rdev->ops->tx_control_port(&rdev->wiphy, dev, buf, len,
-					 dest, proto, noencrypt);
-	trace_rdev_return_int(&rdev->wiphy, ret);
+					 dest, proto, noencrypt, cookie);
+	if (cookie)
+		trace_rdev_return_int_cookie(&rdev->wiphy, ret, *cookie);
+	else
+		trace_rdev_return_int(&rdev->wiphy, ret);
 	return ret;
 }
 
diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index f2ab44a2a3e4..b23cab016521 100644
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -2861,6 +2861,23 @@ TRACE_EVENT(cfg80211_mgmt_tx_status,
 		  WDEV_PR_ARG, __entry->cookie, BOOL_TO_STR(__entry->ack))
 );
 
+TRACE_EVENT(cfg80211_control_port_tx_status,
+	TP_PROTO(struct wireless_dev *wdev, u64 cookie, bool ack),
+	TP_ARGS(wdev, cookie, ack),
+	TP_STRUCT__entry(
+		WDEV_ENTRY
+		__field(u64, cookie)
+		__field(bool, ack)
+	),
+	TP_fast_assign(
+		WDEV_ASSIGN;
+		__entry->cookie = cookie;
+		__entry->ack = ack;
+	),
+	TP_printk(WDEV_PR_FMT", cookie: %llu, ack: %s",
+		  WDEV_PR_ARG, __entry->cookie, BOOL_TO_STR(__entry->ack))
+);
+
 TRACE_EVENT(cfg80211_rx_control_port,
 	TP_PROTO(struct net_device *netdev, struct sk_buff *skb,
 		 bool unencrypted),