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>
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 3abcbba..afa2838 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1424,6 +1424,10 @@
}
CMD(start_p2p_device, START_P2P_DEVICE);
CMD(set_mcast_rate, SET_MCAST_RATE);
+ if (split) {
+ CMD(crit_proto_start, CRIT_PROTOCOL_START);
+ CMD(crit_proto_stop, CRIT_PROTOCOL_STOP);
+ }
#ifdef CONFIG_NL80211_TESTMODE
CMD(testmode_cmd, TESTMODE);
@@ -8216,6 +8220,64 @@
return rdev_update_ft_ies(rdev, dev, &ft_params);
}
+static int nl80211_crit_protocol_start(struct sk_buff *skb,
+ struct genl_info *info)
+{
+ struct cfg80211_registered_device *rdev = info->user_ptr[0];
+ struct wireless_dev *wdev = info->user_ptr[1];
+ enum nl80211_crit_proto_id proto = NL80211_CRIT_PROTO_UNSPEC;
+ u16 duration;
+ int ret;
+
+ if (!rdev->ops->crit_proto_start)
+ return -EOPNOTSUPP;
+
+ if (WARN_ON(!rdev->ops->crit_proto_stop))
+ return -EINVAL;
+
+ if (rdev->crit_proto_nlportid)
+ return -EBUSY;
+
+ /* determine protocol if provided */
+ if (info->attrs[NL80211_ATTR_CRIT_PROT_ID])
+ proto = nla_get_u16(info->attrs[NL80211_ATTR_CRIT_PROT_ID]);
+
+ if (proto >= NUM_NL80211_CRIT_PROTO)
+ return -EINVAL;
+
+ /* timeout must be provided */
+ if (!info->attrs[NL80211_ATTR_MAX_CRIT_PROT_DURATION])
+ return -EINVAL;
+
+ duration =
+ nla_get_u16(info->attrs[NL80211_ATTR_MAX_CRIT_PROT_DURATION]);
+
+ if (duration > NL80211_CRIT_PROTO_MAX_DURATION)
+ return -ERANGE;
+
+ ret = rdev_crit_proto_start(rdev, wdev, proto, duration);
+ if (!ret)
+ rdev->crit_proto_nlportid = info->snd_portid;
+
+ return ret;
+}
+
+static int nl80211_crit_protocol_stop(struct sk_buff *skb,
+ struct genl_info *info)
+{
+ struct cfg80211_registered_device *rdev = info->user_ptr[0];
+ struct wireless_dev *wdev = info->user_ptr[1];
+
+ if (!rdev->ops->crit_proto_stop)
+ return -EOPNOTSUPP;
+
+ if (rdev->crit_proto_nlportid) {
+ rdev->crit_proto_nlportid = 0;
+ rdev_crit_proto_stop(rdev, wdev);
+ }
+ return 0;
+}
+
#define NL80211_FLAG_NEED_WIPHY 0x01
#define NL80211_FLAG_NEED_NETDEV 0x02
#define NL80211_FLAG_NEED_RTNL 0x04
@@ -8905,6 +8967,22 @@
.internal_flags = NL80211_FLAG_NEED_NETDEV_UP |
NL80211_FLAG_NEED_RTNL,
},
+ {
+ .cmd = NL80211_CMD_CRIT_PROTOCOL_START,
+ .doit = nl80211_crit_protocol_start,
+ .policy = nl80211_policy,
+ .flags = GENL_ADMIN_PERM,
+ .internal_flags = NL80211_FLAG_NEED_WDEV_UP |
+ NL80211_FLAG_NEED_RTNL,
+ },
+ {
+ .cmd = NL80211_CMD_CRIT_PROTOCOL_STOP,
+ .doit = nl80211_crit_protocol_stop,
+ .policy = nl80211_policy,
+ .flags = GENL_ADMIN_PERM,
+ .internal_flags = NL80211_FLAG_NEED_WDEV_UP |
+ NL80211_FLAG_NEED_RTNL,
+ }
};
static struct genl_multicast_group nl80211_mlme_mcgrp = {
@@ -10650,6 +10728,45 @@
}
EXPORT_SYMBOL(cfg80211_ft_event);
+void cfg80211_crit_proto_stopped(struct wireless_dev *wdev, gfp_t gfp)
+{
+ struct cfg80211_registered_device *rdev;
+ struct sk_buff *msg;
+ void *hdr;
+ u32 nlportid;
+
+ rdev = wiphy_to_dev(wdev->wiphy);
+ if (!rdev->crit_proto_nlportid)
+ return;
+
+ nlportid = rdev->crit_proto_nlportid;
+ rdev->crit_proto_nlportid = 0;
+
+ msg = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp);
+ if (!msg)
+ return;
+
+ hdr = nl80211hdr_put(msg, 0, 0, 0, NL80211_CMD_CRIT_PROTOCOL_STOP);
+ if (!hdr)
+ goto nla_put_failure;
+
+ if (nla_put_u32(msg, NL80211_ATTR_WIPHY, rdev->wiphy_idx) ||
+ nla_put_u64(msg, NL80211_ATTR_WDEV, wdev_id(wdev)))
+ goto nla_put_failure;
+
+ genlmsg_end(msg, hdr);
+
+ genlmsg_unicast(wiphy_net(&rdev->wiphy), msg, nlportid);
+ return;
+
+ nla_put_failure:
+ if (hdr)
+ genlmsg_cancel(msg, hdr);
+ nlmsg_free(msg);
+
+}
+EXPORT_SYMBOL(cfg80211_crit_proto_stopped);
+
/* initialisation/exit functions */
int nl80211_init(void)