nl80211: add API to probe a client

When the AP SME in hostapd is used it wants to
probe the clients when they have been idle for
some time. Add explicit API to support this.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index ff39e4b..901a70d 100644 (file)
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -519,6 +519,14 @@
  *     If used as the command it must have an interface index and you can
  *     only unsubscribe from the event by closing the socket.
  *
+ * @NL80211_CMD_PROBE_CLIENT: Probe an associated station on an AP interface
+ *     by sending a null data frame to it and reporting when the frame is
+ *     acknowleged. This is used to allow timing out inactive clients. Uses
+ *     %NL80211_ATTR_IFINDEX and %NL80211_ATTR_MAC. The command returns a
+ *     direct reply with an %NL80211_ATTR_COOKIE that is later used to match
+ *     up the event with the request. The event includes the same data and
+ *     has %NL80211_ATTR_ACK set if the frame was ACKed.
+ *
  * @NL80211_CMD_MAX: highest used command number
  * @__NL80211_CMD_AFTER_LAST: internal use
  */
@@ -650,6 +658,8 @@ enum nl80211_commands {
 
        NL80211_CMD_UNEXPECTED_FRAME,
 
+       NL80211_CMD_PROBE_CLIENT,
+
        /* add new commands above here */
 
        /* used to define NL80211_CMD_MAX below */

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 86d207d..389e85e 100644 (file)
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1432,6 +1432,9 @@ struct cfg80211_gtk_rekey_data {
  *
  * @tdls_mgmt: Transmit a TDLS management frame.
  * @tdls_oper: Perform a high-level TDLS operation (e.g. TDLS link setup).
+ *
+ * @probe_client: probe an associated client, must return a cookie that it
+ *     later passes to cfg80211_probe_status().
  */
 struct cfg80211_ops {
        int     (*suspend)(struct wiphy *wiphy, struct cfg80211_wowlan *wow);
@@ -1621,6 +1624,9 @@ struct cfg80211_ops {
                             u16 status_code, const u8 *buf, size_t len);
        int     (*tdls_oper)(struct wiphy *wiphy, struct net_device *dev,
                             u8 *peer, enum nl80211_tdls_operation oper);
+
+       int     (*probe_client)(struct wiphy *wiphy, struct net_device *dev,
+                               const u8 *peer, u64 *cookie);
 };
 
 /*
@@ -3216,6 +3222,17 @@ void cfg80211_pmksa_candidate_notify(struct net_device *dev, int index,
 bool cfg80211_rx_spurious_frame(struct net_device *dev,
                                const u8 *addr, gfp_t gfp);
 
+/**
+ * cfg80211_probe_status - notify userspace about probe status
+ * @dev: the device the probe was sent on
+ * @addr: the address of the peer
+ * @cookie: the cookie filled in @probe_client previously
+ * @acked: indicates whether probe was acked or not
+ * @gfp: allocation flags
+ */
+void cfg80211_probe_status(struct net_device *dev, const u8 *addr,
+                          u64 cookie, bool acked, gfp_t gfp);
+
 /* Logging, debugging and troubleshooting/diagnostic helpers. */
 
 /* wiphy_printk helpers, similar to dev_printk */

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 2094c84..a8eda12 100644 (file)
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -890,6 +890,7 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
        }
        if (dev->wiphy.flags & WIPHY_FLAG_SUPPORTS_SCHED_SCAN)
                CMD(sched_scan_start, START_SCHED_SCAN);
+       CMD(probe_client, PROBE_CLIENT);
 
 #undef CMD
 
@@ -5853,6 +5854,59 @@ static int nl80211_register_unexpected_frame(struct sk_buff *skb,
        return 0;
 }
 
+static int nl80211_probe_client(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 sk_buff *msg;
+       void *hdr;
+       const u8 *addr;
+       u64 cookie;
+       int err;
+
+       if (wdev->iftype != NL80211_IFTYPE_AP &&
+           wdev->iftype != NL80211_IFTYPE_P2P_GO)
+               return -EOPNOTSUPP;
+
+       if (!info->attrs[NL80211_ATTR_MAC])
+               return -EINVAL;
+
+       if (!rdev->ops->probe_client)
+               return -EOPNOTSUPP;
+
+       msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+       if (!msg)
+               return -ENOMEM;
+
+       hdr = nl80211hdr_put(msg, info->snd_pid, info->snd_seq, 0,
+                            NL80211_CMD_PROBE_CLIENT);
+
+       if (IS_ERR(hdr)) {
+               err = PTR_ERR(hdr);
+               goto free_msg;
+       }
+
+       addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
+
+       err = rdev->ops->probe_client(&rdev->wiphy, dev, addr, &cookie);
+       if (err)
+               goto free_msg;
+
+       NLA_PUT_U64(msg, NL80211_ATTR_COOKIE, cookie);
+
+       genlmsg_end(msg, hdr);
+
+       return genlmsg_reply(msg, info);
+
+ nla_put_failure:
+       err = -ENOBUFS;
+ free_msg:
+       nlmsg_free(msg);
+       return err;
+}
+
 #define NL80211_FLAG_NEED_WIPHY                0x01
 #define NL80211_FLAG_NEED_NETDEV       0x02
 #define NL80211_FLAG_NEED_RTNL         0x04
@@ -6416,6 +6470,14 @@ static struct genl_ops nl80211_ops[] = {
                .internal_flags = NL80211_FLAG_NEED_NETDEV |
                                  NL80211_FLAG_NEED_RTNL,
        },
+       {
+               .cmd = NL80211_CMD_PROBE_CLIENT,
+               .doit = nl80211_probe_client,
+               .policy = nl80211_policy,
+               .flags = GENL_ADMIN_PERM,
+               .internal_flags = NL80211_FLAG_NEED_NETDEV |
+                                 NL80211_FLAG_NEED_RTNL,
+       },
 };
 
 static struct genl_multicast_group nl80211_mlme_mcgrp = {
@@ -7478,6 +7540,48 @@ nl80211_send_cqm_pktloss_notify(struct cfg80211_registered_device *rdev,
        nlmsg_free(msg);
 }
 
+void cfg80211_probe_status(struct net_device *dev, const u8 *addr,
+                          u64 cookie, bool acked, gfp_t gfp)
+{
+       struct wireless_dev *wdev = dev->ieee80211_ptr;
+       struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
+       struct sk_buff *msg;
+       void *hdr;
+       int err;
+
+       msg = nlmsg_new(NLMSG_GOODSIZE, gfp);
+       if (!msg)
+               return;
+
+       hdr = nl80211hdr_put(msg, 0, 0, 0, NL80211_CMD_PROBE_CLIENT);
+       if (!hdr) {
+               nlmsg_free(msg);
+               return;
+       }
+
+       NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, rdev->wiphy_idx);
+       NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, dev->ifindex);
+       NLA_PUT(msg, NL80211_ATTR_MAC, ETH_ALEN, addr);
+       NLA_PUT_U64(msg, NL80211_ATTR_COOKIE, cookie);
+       if (acked)
+               NLA_PUT_FLAG(msg, NL80211_ATTR_ACK);
+
+       err = genlmsg_end(msg, hdr);
+       if (err < 0) {
+               nlmsg_free(msg);
+               return;
+       }
+
+       genlmsg_multicast_netns(wiphy_net(&rdev->wiphy), msg, 0,
+                               nl80211_mlme_mcgrp.id, gfp);
+       return;
+
+ nla_put_failure:
+       genlmsg_cancel(msg, hdr);
+       nlmsg_free(msg);
+}
+EXPORT_SYMBOL(cfg80211_probe_status);
+
 static int nl80211_netlink_notify(struct notifier_block * nb,
                                  unsigned long state,
                                  void *_notify)