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@xxxxxxxxxxxx>
Reviewed-by: Franky (Zhenhui) Lin <frankyl@xxxxxxxxxxxx>
Signed-off-by: Arend van Spriel <arend@xxxxxxxxxxxx>
---
Hi Johannes,
I reworked the patch based on your comment in this V6. It
applies to the master branch on top of commit:
5253ffb mac80211: always pick a basic rate to tx RTS/CTS for pre-HT rates
Regards, Arend
Changelog:
----------
V6:
- added crit_proto_stopped event message.
- use nlportid as flag for critical protocol being active.
- return error when duration is over specified limit.
- remove logic from rdev_* inline wrappers.
- added more documentation.
- some renaming of identifiers.
V5:
- change return type for .crit_prot_stop() to void.
- correct limiting the duration.
V4:
- added cfg80211_crit_proto_stopped() for drivers to use.
- added back protocol identifier for drivers to use.
- reject starting critical protocol session when already started.
- critical protocol session tracked per registered device.
V3:
- remove protocol identifier.
- remove delayed work from cfg80211.
- guard maximum limit for duration.
- do .crit_proto_stop() upon netlink socket release.
V2:
- subject changed. Below previous subject is given for reference:
[RFC] cfg80211: configuration of Bluetooth coexistence mode
- introduced dedicated nl80211 API.
V1:
- initial proposal.
---
include/net/cfg80211.h | 27 ++++++++++
include/uapi/linux/nl80211.h | 40 +++++++++++++++
net/wireless/core.h | 3 ++
net/wireless/mlme.c | 5 ++
net/wireless/nl80211.c | 116 ++++++++++++++++++++++++++++++++++++++++++
net/wireless/rdev-ops.h | 24 ++++++++-
net/wireless/trace.h | 35 +++++++++++++
7 files changed, 249 insertions(+), 1 deletion(-)
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 57870b6..7afd1ad 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);
};
/*
@@ -2830,6 +2842,7 @@ struct cfg80211_cached_keys;
* @p2p_started: true if this is a P2P Device that has been started
* @cac_started: true if DFS channel availability check has been started
* @cac_start_time: timestamp (jiffies) when the dfs state was entered.
+ * @crit_proto_started: true if crit_proto_start() has been done.
*/
struct wireless_dev {
struct wiphy *wiphy;
@@ -2884,6 +2897,8 @@ struct wireless_dev {
bool cac_started;
unsigned long cac_start_time;
+ bool crit_proto_started;
+
#ifdef CONFIG_CFG80211_WEXT
/* wext data */
struct {
@@ -4126,6 +4141,18 @@ 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. This function must not be called
+ * in .crit_proto_stop() context.
+ */
+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 */
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 79da871..c68373b 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -639,6 +639,13 @@
* with the relevant Information Elements. This event is used to report
* received FT IEs (MDIE, FTIE, RSN IE, TIE, RICIE).
*
+ * @NL80211_CMD_CRIT_PROTOCOL_START: Indicates user-space will start running
+ * a critical protocol that needs more reliability in the connection to
+ * complete.
+ *
+ * @NL80211_CMD_CRIT_PROTOCOL_STOP: Indicates the connection reliability can
+ * return back to normal.
+ *
* @NL80211_CMD_MAX: highest used command number
* @__NL80211_CMD_AFTER_LAST: internal use
*/
@@ -798,6 +805,10 @@ enum nl80211_commands {
NL80211_CMD_UPDATE_FT_IES,
NL80211_CMD_FT_EVENT,
+ NL80211_CMD_CRIT_PROTOCOL_START,
+ NL80211_CMD_CRIT_PROTOCOL_STOP,
+ NL80211_CMD_CRIT_PROTOCOL_STOPPED_EVENT,
+
/* add new commands above here */
/* used to define NL80211_CMD_MAX below */
@@ -1414,6 +1425,11 @@ enum nl80211_commands {
* @NL80211_ATTR_IE_RIC: Resource Information Container Information
* Element
*
+ * @NL80211_ATTR_CRIT_PROT_ID: critical protocol identifier requiring increased
+ * reliability, see &enum nl80211_crit_proto_id (u16).
+ * @NL80211_ATTR_MAX_CRIT_PROT_DURATION: duration in milliseconds in which
+ * the connection should have increased reliability (u16).
+ *
* @NL80211_ATTR_MAX: highest attribute number currently defined
* @__NL80211_ATTR_AFTER_LAST: internal use
*/
@@ -1709,6 +1725,9 @@ enum nl80211_attrs {
NL80211_ATTR_MDID,
NL80211_ATTR_IE_RIC,
+ NL80211_ATTR_CRIT_PROT_ID,
+ NL80211_ATTR_MAX_CRIT_PROT_DURATION,
+
/* add attributes here, update the policy in nl80211.c */
__NL80211_ATTR_AFTER_LAST,
@@ -3682,4 +3701,25 @@ enum nl80211_protocol_features {
NL80211_PROTOCOL_FEATURE_SPLIT_WIPHY_DUMP = 1 << 0,
};
+/**
+ * enum nl80211_crit_proto_id - nl80211 critical protocol identifiers
+ *
+ * @NL80211_CRIT_PROTO_UNSPEC: protocol unspecified.
+ * @NL80211_CRIT_PROTO_DHCP: BOOTP or DHCPv6 protocol.
+ * @NL80211_CRIT_PROTO_EAPOL: EAPOL protocol.
+ * @NL80211_CRIT_PROTO_APIPA: APIPA protocol.
+ * @NUM_NL80211_CRIT_PROTO: must be kept last.
+ */
+enum nl80211_crit_proto_id {
+ NL80211_CRIT_PROTO_UNSPEC,
+ NL80211_CRIT_PROTO_DHCP,
+ NL80211_CRIT_PROTO_EAPOL,
+ NL80211_CRIT_PROTO_APIPA,
+ /* add other protocols before this one */
+ NUM_NL80211_CRIT_PROTO
+};
+
+/* maximum duration for critical protocol measures */
+#define NL80211_CRIT_PROTO_MAX_DURATION 5000 /* msec */
+
#endif /* __LINUX_NL80211_H */
diff --git a/net/wireless/core.h b/net/wireless/core.h
index d5d06fd..eac5308 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -88,6 +88,9 @@ struct cfg80211_registered_device {
struct delayed_work dfs_update_channels_wk;
+ /* netlink port which started critical protocol (0 means not started) */
+ u32 crit_proto_nlportid;
+
/* must be last because of the way we do wiphy_priv(),
* and it should at least be aligned to NETDEV_ALIGN */
struct wiphy wiphy __aligned(NETDEV_ALIGN);
diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
index 390198b..719c2f8 100644
--- a/net/wireless/mlme.c
+++ b/net/wireless/mlme.c
@@ -648,6 +648,11 @@ void cfg80211_mlme_unregister_socket(struct wireless_dev *wdev, u32 nlportid)
spin_unlock_bh(&wdev->mgmt_registrations_lock);
+ if (nlportid && rdev->crit_proto_nlportid == nlportid) {
+ rdev_crit_proto_stop(rdev, wdev);
+ rdev->crit_proto_nlportid = 0;
+ }
+
if (nlportid == wdev->ap_unexpected_nlportid)
wdev->ap_unexpected_nlportid = 0;
}
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index f924d45..533eccf 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1417,6 +1417,10 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
}
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);
@@ -8196,6 +8200,64 @@ static int nl80211_update_ft_ies(struct sk_buff *skb, struct genl_info *info)
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_stop(rdev, wdev);
+ rdev->crit_proto_nlportid = 0;
+ }
+ return 0;
+}
+
#define NL80211_FLAG_NEED_WIPHY 0x01
#define NL80211_FLAG_NEED_NETDEV 0x02
#define NL80211_FLAG_NEED_RTNL 0x04
@@ -8885,6 +8947,22 @@ static struct genl_ops nl80211_ops[] = {
.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 = {
@@ -10630,6 +10708,44 @@ void cfg80211_ft_event(struct net_device *netdev,
}
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);
+ WARN_ON(!rdev->crit_proto_nlportid);
+ 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_STOPPED_EVENT);
+ 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)
diff --git a/net/wireless/rdev-ops.h b/net/wireless/rdev-ops.h
index d77e1c1..9f15f0a 100644
--- a/net/wireless/rdev-ops.h
+++ b/net/wireless/rdev-ops.h
@@ -875,7 +875,7 @@ static inline void rdev_stop_p2p_device(struct cfg80211_registered_device *rdev,
trace_rdev_stop_p2p_device(&rdev->wiphy, wdev);
rdev->ops->stop_p2p_device(&rdev->wiphy, wdev);
trace_rdev_return_void(&rdev->wiphy);
-}
+}
static inline int rdev_set_mac_acl(struct cfg80211_registered_device *rdev,
struct net_device *dev,
@@ -901,4 +901,26 @@ static inline int rdev_update_ft_ies(struct cfg80211_registered_device *rdev,
return ret;
}
+static inline int rdev_crit_proto_start(struct cfg80211_registered_device *rdev,
+ struct wireless_dev *wdev,
+ enum nl80211_crit_proto_id protocol,
+ u16 duration)
+{
+ int ret;
+
+ trace_rdev_crit_proto_start(&rdev->wiphy, wdev, protocol, duration);
+ ret = rdev->ops->crit_proto_start(&rdev->wiphy, wdev,
+ protocol, duration);
+ trace_rdev_return_int(&rdev->wiphy, ret);
+ return ret;
+}
+
+static inline void rdev_crit_proto_stop(struct cfg80211_registered_device *rdev,
+ struct wireless_dev *wdev)
+{
+ trace_rdev_crit_proto_stop(&rdev->wiphy, wdev);
+ rdev->ops->crit_proto_stop(&rdev->wiphy, wdev);
+ trace_rdev_return_void(&rdev->wiphy);
+}
+
#endif /* __CFG80211_RDEV_OPS */
diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index ccadef2..499c982 100644
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -1805,6 +1805,41 @@ TRACE_EVENT(rdev_update_ft_ies,
WIPHY_PR_ARG, NETDEV_PR_ARG, __entry->md)
);
+TRACE_EVENT(rdev_crit_proto_start,
+ TP_PROTO(struct wiphy *wiphy, struct wireless_dev *wdev,
+ enum nl80211_crit_proto_id protocol, u16 duration),
+ TP_ARGS(wiphy, wdev, protocol, duration),
+ TP_STRUCT__entry(
+ WIPHY_ENTRY
+ WDEV_ENTRY
+ __field(u16, proto)
+ __field(u16, duration)
+ ),
+ TP_fast_assign(
+ WIPHY_ASSIGN;
+ WDEV_ASSIGN;
+ __entry->proto = protocol;
+ __entry->duration = duration;
+ ),
+ TP_printk(WIPHY_PR_FMT ", " WDEV_PR_FMT ", proto=%x, duration=%u",
+ WIPHY_PR_ARG, WDEV_PR_ARG, __entry->proto, __entry->duration)
+);
+
+TRACE_EVENT(rdev_crit_proto_stop,
+ TP_PROTO(struct wiphy *wiphy, struct wireless_dev *wdev),
+ TP_ARGS(wiphy, wdev),
+ TP_STRUCT__entry(
+ WIPHY_ENTRY
+ WDEV_ENTRY
+ ),
+ TP_fast_assign(
+ WIPHY_ASSIGN;
+ WDEV_ASSIGN;
+ ),
+ TP_printk(WIPHY_PR_FMT ", " WDEV_PR_FMT,
+ WIPHY_PR_ARG, WDEV_PR_ARG)
+);
+
/*************************************************************
* cfg80211 exported functions traces *
*************************************************************/
--
1.7.10.4
--
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