cfg80211: introduce critical protocol indication from user-space

Some protocols need a more reliable connection to complete
successful in reasonable time. This patch adds a user-space
API to indicate the wireless driver that a critical protocol
is about to commence and when it is done, using nl80211 primitives
NL80211_CMD_CRIT_PROTOCOL_START and NL80211_CRIT_PROTOCOL_STOP.

There can be only on critical protocol session started per
registered cfg80211 device.

The driver can support this by implementing the cfg80211 callbacks
.crit_proto_start() and .crit_proto_stop(). Examples of protocols
that can benefit from this are DHCP, EAPOL, APIPA. Exactly how the
link can/should be made more reliable is up to the driver. Things
to consider are avoid scanning, no multi-channel operations, and
alter coexistence schemes.

Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index dff96d8cafcd..26b5b692c22b 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -2002,6 +2002,12 @@ struct cfg80211_update_ft_ies_params {
  * @update_ft_ies: Provide updated Fast BSS Transition information to the
  *      driver. If the SME is in the driver/firmware, this information can be
  *      used in building Authentication and Reassociation Request frames.
+ *
+ * @crit_proto_start: Indicates a critical protocol needs more link reliability
+ *      for a given duration (milliseconds). The protocol is provided so the
+ *      driver can take the most appropriate actions.
+ * @crit_proto_stop: Indicates critical protocol no longer needs increased link
+ *      reliability. This operation can not fail.
  */
 struct cfg80211_ops {
         int     (*suspend)(struct wiphy *wiphy, struct cfg80211_wowlan *wow);
@@ -2231,6 +2237,12 @@ struct cfg80211_ops {
                                          struct cfg80211_chan_def *chandef);
         int     (*update_ft_ies)(struct wiphy *wiphy, struct net_device *dev,
                                  struct cfg80211_update_ft_ies_params *ftie);
+        int     (*crit_proto_start)(struct wiphy *wiphy,
+                                    struct wireless_dev *wdev,
+                                    enum nl80211_crit_proto_id protocol,
+                                    u16 duration);
+        void    (*crit_proto_stop)(struct wiphy *wiphy,
+                                   struct wireless_dev *wdev);
 };
 
 /*
@@ -4137,6 +4149,17 @@ void cfg80211_report_wowlan_wakeup(struct wireless_dev *wdev,
                                    struct cfg80211_wowlan_wakeup *wakeup,
                                    gfp_t gfp);
 
+/**
+ * cfg80211_crit_proto_stopped() - indicate critical protocol stopped by driver.
+ *
+ * @wdev: the wireless device for which critical protocol is stopped.
+ *
+ * This function can be called by the driver to indicate it has reverted
+ * operation back to normal. One reason could be that the duration given
+ * by .crit_proto_start() has expired.
+ */
+void cfg80211_crit_proto_stopped(struct wireless_dev *wdev, gfp_t gfp);
+
 /* Logging, debugging and troubleshooting/diagnostic helpers. */
 
 /* wiphy_printk helpers, similar to dev_printk */