Allow to implement P2P find phase in the driver/firmware.
Offload scheme designed as follows:
- Driver provide methods start_p2p_find and stop_p2p_find in the cfg80211_ops;
- Driver indicate firmware or driver responds to the probe requests by setting
feature NL80211_FEATURE_P2P_PROBE_RESP_OFFLOAD
- wpa_supplicant analyses methods supported to discover p2p offload support;
- wpa_supplicant analyses feature flags to discover p2p probe response
offload support;
to perform p2p scan, wpa_supplicant:
- perform legacy scan, through driver's cfg80211_ops 'scan' method
- configure rx management filter to get probe-request and probe-response frames
- start p2p find via driver's cfg80211_ops start_p2p_find method
- driver start p2p find with hardware and notify wpa_supplicant with
cfg80211_p2p_find_notify_start()
- driver/firmware toggle search/listen states. Received probe-request and
probe-response frames passed to the wpa_supplicant via cfg80211_rx_mgmt
- when wpa_supplicant wants to stop p2p find, it calls driver's
cfg80211_ops stop_p2p_find method. Alternatively, driver/firmware may decide
to stop p2p find. In all cases, driver notifies wpa_supplicant using
cfg80211_p2p_find_notify_end()
All driver to user space communication done through nl80211 layer.
Offloaded P2P find does not support variations like progressive scan.
Signed-off-by: Vladimir Kondratiev <[email protected]>
---
include/net/cfg80211.h | 60 +++++++++++++++
include/uapi/linux/nl80211.h | 13 ++++
net/wireless/nl80211.c | 167 ++++++++++++++++++++++++++++++++++++++++++
net/wireless/rdev-ops.h | 19 +++++
net/wireless/trace.h | 34 +++++++++
5 files changed, 293 insertions(+)
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index bdba9b6..f7f11f2 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1780,6 +1780,34 @@ struct cfg80211_update_ft_ies_params {
};
/**
+ * struct cfg80211_p2p_find_params - parameters for P2P find
+ * @probe_ie: extra IE's for probe frames
+ * @probe_ie_len: length, bytes, of @probe_ie
+ * @probe_resp_ie: extra IE's for probe response frames
+ * @probe_resp_ie_len: length, bytes, of @probe_resp_ie
+ * Driver/firmware may add additional IE's as well as modify
+ * provided ones; typical IE's to be added are
+ * WLAN_EID_EXT_SUPP_RATES, WLAN_EID_DS_PARAMS,
+ * WLAN_EID_HT_CAPABILITY.
+ * @min_discoverable_interval: and
+ * @max_discoverable_interval: min/max for random multiplier of 100TU's
+ * for the listen state duration
+ * @n_channels: number of channels to operate on
+ * @channels: channels to operate on
+ */
+struct cfg80211_p2p_find_params {
+ const u8 *probe_ie;
+ size_t probe_ie_len;
+ const u8 *probe_resp_ie;
+ size_t probe_resp_ie_len;
+ u32 min_discoverable_interval;
+ u32 max_discoverable_interval;
+
+ int n_channels;
+ struct ieee80211_channel **channels;
+};
+
+/**
* struct cfg80211_ops - backend description for wireless configuration
*
* This struct is registered by fullmac card drivers and/or wireless stacks
@@ -1998,6 +2026,15 @@ struct cfg80211_update_ft_ies_params {
* advertise the support for MAC based ACL have to implement this callback.
*
* @start_radar_detection: Start radar detection in the driver.
+ *
+ * start_p2p_find: start P2P find phase
+ * Parameters include IEs for probe/probe-resp frames;
+ * and channels to operate on.
+ * Parameters are not retained after call, driver need to copy data if
+ * it need it later.
+ * P2P find can't run concurrently with ROC or scan, and driver should
+ * check this.
+ * stop_p2p_find: stop P2P find phase
*/
struct cfg80211_ops {
int (*suspend)(struct wiphy *wiphy, struct cfg80211_wowlan *wow);
@@ -2227,6 +2264,12 @@ 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 (*start_p2p_find)(struct wiphy *wiphy,
+ struct wireless_dev *wdev,
+ struct cfg80211_p2p_find_params *params);
+ void (*stop_p2p_find)(struct wiphy *wiphy,
+ struct wireless_dev *wdev);
};
/*
@@ -4122,6 +4165,23 @@ void cfg80211_report_wowlan_wakeup(struct wireless_dev *wdev,
struct cfg80211_wowlan_wakeup *wakeup,
gfp_t gfp);
+/**
+ * cfg80211_p2p_find_notify_start - report p2p find phase started
+ * @wdev: the wireless device reporting the event
+ * @gfp: allocation flags
+ */
+void cfg80211_p2p_find_notify_start(struct wireless_dev *wdev, gfp_t gfp);
+
+/**
+ * cfg80211_p2p_find_notify_end - report p2p find phase ended
+ * @wdev: the wireless device reporting the event
+ * @gfp: allocation flags
+ *
+ * p2p find phase may be ended either unsolicited or in response to
+ * ops->p2p_stop_find
+ */
+void cfg80211_p2p_find_notify_end(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..c8a8fe0 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -798,6 +798,9 @@ enum nl80211_commands {
NL80211_CMD_UPDATE_FT_IES,
NL80211_CMD_FT_EVENT,
+ NL80211_CMD_START_P2P_FIND,
+ NL80211_CMD_STOP_P2P_FIND,
+
/* add new commands above here */
/* used to define NL80211_CMD_MAX below */
@@ -1414,6 +1417,10 @@ enum nl80211_commands {
* @NL80211_ATTR_IE_RIC: Resource Information Container Information
* Element
*
+ * @NL80211_ATTR_MIN_DISCOVERABLE_INTERVAL:
+ * @NL80211_ATTR_MAX_DISCOVERABLE_INTERVAL: min/max discoverable interval
+ * for the p2p find, represented as u32
+ *
* @NL80211_ATTR_MAX: highest attribute number currently defined
* @__NL80211_ATTR_AFTER_LAST: internal use
*/
@@ -1709,6 +1716,9 @@ enum nl80211_attrs {
NL80211_ATTR_MDID,
NL80211_ATTR_IE_RIC,
+ NL80211_ATTR_MIN_DISCOVERABLE_INTERVAL,
+ NL80211_ATTR_MAX_DISCOVERABLE_INTERVAL,
+
/* add attributes here, update the policy in nl80211.c */
__NL80211_ATTR_AFTER_LAST,
@@ -3538,6 +3548,8 @@ enum nl80211_ap_sme_features {
* Peering Management entity which may be implemented by registering for
* beacons or NL80211_CMD_NEW_PEER_CANDIDATE events. The mesh beacon is
* still generated by the driver.
+ * @NL80211_FEATURE_P2P_PROBE_RESP_OFFLOAD: When in P2P find phase,
+ * the device responds to probe-requests in hardware.
*/
enum nl80211_feature_flags {
NL80211_FEATURE_SK_TX_STATUS = 1 << 0,
@@ -3557,6 +3569,7 @@ enum nl80211_feature_flags {
NL80211_FEATURE_ADVERTISE_CHAN_LIMITS = 1 << 14,
NL80211_FEATURE_FULL_AP_CLIENT_STATE = 1 << 15,
NL80211_FEATURE_USERSPACE_MPM = 1 << 16,
+ NL80211_FEATURE_P2P_PROBE_RESP_OFFLOAD = 1 << 17,
};
/**
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index f924d45..374a667 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -378,6 +378,8 @@ static const struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] = {
[NL80211_ATTR_MDID] = { .type = NLA_U16 },
[NL80211_ATTR_IE_RIC] = { .type = NLA_BINARY,
.len = IEEE80211_MAX_DATA_LEN },
+ [NL80211_ATTR_MIN_DISCOVERABLE_INTERVAL] = { .type = NLA_U32 },
+ [NL80211_ATTR_MAX_DISCOVERABLE_INTERVAL] = { .type = NLA_U32 },
};
/* policy for the key attributes */
@@ -1417,6 +1419,8 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
}
CMD(start_p2p_device, START_P2P_DEVICE);
CMD(set_mcast_rate, SET_MCAST_RATE);
+ CMD(start_p2p_find, START_P2P_FIND);
+ CMD(stop_p2p_find, STOP_P2P_FIND);
#ifdef CONFIG_NL80211_TESTMODE
CMD(testmode_cmd, TESTMODE);
@@ -8196,6 +8200,113 @@ 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_start_p2p_find(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];
+ struct wiphy *wiphy = &rdev->wiphy;
+ struct cfg80211_p2p_find_params params = {};
+ struct nlattr *attr_freq = info->attrs[NL80211_ATTR_SCAN_FREQUENCIES];
+ struct nlattr *attr;
+ int err, tmp, n_channels, i = 0;
+ struct ieee80211_channel **channels = NULL;
+
+ switch (wdev->iftype) {
+ case NL80211_IFTYPE_P2P_DEVICE:
+ case NL80211_IFTYPE_STATION:
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ if (!is_valid_ie_attr(info->attrs[NL80211_ATTR_IE]))
+ return -EINVAL;
+
+ if (!is_valid_ie_attr(info->attrs[NL80211_ATTR_IE_PROBE_RESP]))
+ return -EINVAL;
+
+ if (!rdev->ops->start_p2p_find || !rdev->ops->stop_p2p_find)
+ return -EOPNOTSUPP;
+
+ if (rdev->scan_req)
+ return -EBUSY;
+
+ if (attr_freq) {
+ n_channels = validate_scan_freqs(attr_freq);
+ if (!n_channels)
+ return -EINVAL;
+
+ channels = kzalloc(n_channels * sizeof(*channels), GFP_KERNEL);
+ if (!channels)
+ return -ENOMEM;
+
+ /* user specified, bail out if channel not found */
+ nla_for_each_nested(attr, attr_freq, tmp) {
+ struct ieee80211_channel *chan;
+
+ chan = ieee80211_get_channel(wiphy, nla_get_u32(attr));
+
+ if (!chan)
+ return -EINVAL;
+
+ /* ignore disabled channels */
+ if (chan->flags & IEEE80211_CHAN_DISABLED)
+ continue;
+
+ params.channels[i] = chan;
+ i++;
+ }
+ if (!i) {
+ err = -EINVAL;
+ goto out_free;
+ }
+
+ params.n_channels = i;
+ params.channels = channels;
+ }
+
+
+ attr = info->attrs[NL80211_ATTR_IE];
+ if (attr) {
+ params.probe_ie_len = nla_len(attr);
+ params.probe_ie = nla_data(attr);
+ }
+
+ attr = info->attrs[NL80211_ATTR_IE_PROBE_RESP];
+ if (attr) {
+ params.probe_resp_ie_len = nla_len(attr);
+ params.probe_resp_ie = nla_data(attr);
+ }
+
+ attr = info->attrs[NL80211_ATTR_MIN_DISCOVERABLE_INTERVAL];
+ if (attr)
+ params.min_discoverable_interval = nla_get_u32(attr);
+
+ attr = info->attrs[NL80211_ATTR_MAX_DISCOVERABLE_INTERVAL];
+ if (attr)
+ params.max_discoverable_interval = nla_get_u32(attr);
+
+ err = rdev_start_p2p_find(rdev, wdev, ¶ms);
+
+out_free:
+ kfree(channels);
+
+ return err;
+}
+
+static int nl80211_stop_p2p_find(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->start_p2p_find || !rdev->ops->stop_p2p_find)
+ return -EOPNOTSUPP;
+
+ rdev_stop_p2p_find(rdev, wdev);
+
+ return 0;
+}
+
#define NL80211_FLAG_NEED_WIPHY 0x01
#define NL80211_FLAG_NEED_NETDEV 0x02
#define NL80211_FLAG_NEED_RTNL 0x04
@@ -8873,6 +8984,22 @@ static struct genl_ops nl80211_ops[] = {
NL80211_FLAG_NEED_RTNL,
},
{
+ .cmd = NL80211_CMD_START_P2P_FIND,
+ .doit = nl80211_start_p2p_find,
+ .policy = nl80211_policy,
+ .flags = GENL_ADMIN_PERM,
+ .internal_flags = NL80211_FLAG_NEED_WDEV_UP |
+ NL80211_FLAG_NEED_RTNL,
+ },
+ {
+ .cmd = NL80211_CMD_STOP_P2P_FIND,
+ .doit = nl80211_stop_p2p_find,
+ .policy = nl80211_policy,
+ .flags = GENL_ADMIN_PERM,
+ .internal_flags = NL80211_FLAG_NEED_WDEV_UP |
+ NL80211_FLAG_NEED_RTNL,
+ },
+ {
.cmd = NL80211_CMD_GET_PROTOCOL_FEATURES,
.doit = nl80211_get_protocol_features,
.policy = nl80211_policy,
@@ -10547,6 +10674,46 @@ void cfg80211_tdls_oper_request(struct net_device *dev, const u8 *peer,
}
EXPORT_SYMBOL(cfg80211_tdls_oper_request);
+static
+void cfg80211_p2p_find_notify(struct wireless_dev *wdev, int cmd, gfp_t gfp)
+{
+ struct wiphy *wiphy = wdev->wiphy;
+ struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
+ struct sk_buff *msg;
+ void *hdr;
+
+ trace_cfg80211_p2p_find_notify(wdev, cmd);
+ msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+ if (!msg)
+ return;
+
+ hdr = nl80211hdr_put(msg, 0, 0, 0, cmd);
+ if (!hdr) {
+ nlmsg_free(msg);
+ return;
+ }
+
+ if (genlmsg_end(msg, hdr) < 0) {
+ nlmsg_free(msg);
+ return;
+ }
+
+ genlmsg_multicast_netns(wiphy_net(&rdev->wiphy), msg, 0,
+ nl80211_scan_mcgrp.id, GFP_KERNEL);
+}
+
+void cfg80211_p2p_find_notify_start(struct wireless_dev *wdev, gfp_t gfp)
+{
+ cfg80211_p2p_find_notify(wdev, NL80211_CMD_START_P2P_FIND, gfp);
+}
+EXPORT_SYMBOL(cfg80211_p2p_find_notify_start);
+
+void cfg80211_p2p_find_notify_end(struct wireless_dev *wdev, gfp_t gfp)
+{
+ cfg80211_p2p_find_notify(wdev, NL80211_CMD_STOP_P2P_FIND, gfp);
+}
+EXPORT_SYMBOL(cfg80211_p2p_find_notify_end);
+
static int nl80211_netlink_notify(struct notifier_block * nb,
unsigned long state,
void *_notify)
diff --git a/net/wireless/rdev-ops.h b/net/wireless/rdev-ops.h
index d77e1c1..5e43d50 100644
--- a/net/wireless/rdev-ops.h
+++ b/net/wireless/rdev-ops.h
@@ -901,4 +901,23 @@ static inline int rdev_update_ft_ies(struct cfg80211_registered_device *rdev,
return ret;
}
+static inline int rdev_start_p2p_find(struct cfg80211_registered_device *rdev,
+ struct wireless_dev *wdev,
+ struct cfg80211_p2p_find_params *params)
+{
+ int ret;
+ trace_rdev_start_p2p_find(&rdev->wiphy, wdev, params);
+ ret = rdev->ops->start_p2p_find(&rdev->wiphy, wdev, params);
+ trace_rdev_return_int(&rdev->wiphy, ret);
+ return ret;
+}
+
+static inline void rdev_stop_p2p_find(struct cfg80211_registered_device *rdev,
+ struct wireless_dev *wdev)
+{
+ trace_rdev_stop_p2p_find(&rdev->wiphy, wdev);
+ rdev->ops->stop_p2p_find(&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 23e063b..d2faecc 100644
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -1805,6 +1805,26 @@ TRACE_EVENT(rdev_update_ft_ies,
WIPHY_PR_ARG, NETDEV_PR_ARG, __entry->md)
);
+TRACE_EVENT(rdev_start_p2p_find,
+ TP_PROTO(struct wiphy *wiphy, struct wireless_dev *wdev,
+ struct cfg80211_p2p_find_params *params),
+ TP_ARGS(wiphy, wdev, params),
+ 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)
+);
+
+DEFINE_EVENT(wiphy_wdev_evt, rdev_stop_p2p_find,
+ TP_PROTO(struct wiphy *wiphy, struct wireless_dev *wdev),
+ TP_ARGS(wiphy, wdev)
+);
+
/*************************************************************
* cfg80211 exported functions traces *
*************************************************************/
@@ -2459,6 +2479,20 @@ TRACE_EVENT(cfg80211_ft_event,
WIPHY_PR_ARG, NETDEV_PR_ARG, MAC_PR_ARG(target_ap))
);
+TRACE_EVENT(cfg80211_p2p_find_notify,
+ TP_PROTO(struct wireless_dev *wdev, int cmd),
+ TP_ARGS(wdev, cmd),
+ TP_STRUCT__entry(
+ WDEV_ENTRY
+ __field(int, cmd)
+ ),
+ TP_fast_assign(
+ WDEV_ASSIGN;
+ __entry->cmd = cmd;
+ ),
+ TP_printk(WDEV_PR_FMT ", cmd: %d", WDEV_PR_ARG, __entry->cmd)
+);
+
#endif /* !__RDEV_OPS_TRACE || TRACE_HEADER_MULTI_READ */
#undef TRACE_INCLUDE_PATH
--
1.7.10.4
On Thursday, March 21, 2013 01:06:34 PM Vladimir Kondratiev wrote:
> Allow to implement P2P find phase in the driver/firmware.
>
> Offload scheme designed as follows:
>
> - Driver provide methods start_p2p_find and stop_p2p_find in the cfg80211_ops;
> - Driver indicate firmware or driver responds to the probe requests by setting
> feature NL80211_FEATURE_P2P_PROBE_RESP_OFFLOAD
> - wpa_supplicant analyses methods supported to discover p2p offload support;
> - wpa_supplicant analyses feature flags to discover p2p probe response
> offload support;
> to perform p2p scan, wpa_supplicant:
> - perform legacy scan, through driver's cfg80211_ops 'scan' method
> - configure rx management filter to get probe-request and probe-response frames
> - start p2p find via driver's cfg80211_ops start_p2p_find method
> - driver start p2p find with hardware and notify wpa_supplicant with
> cfg80211_p2p_find_notify_start()
> - driver/firmware toggle search/listen states. Received probe-request and
> probe-response frames passed to the wpa_supplicant via cfg80211_rx_mgmt
> - when wpa_supplicant wants to stop p2p find, it calls driver's
> cfg80211_ops stop_p2p_find method. Alternatively, driver/firmware may decide
> to stop p2p find. In all cases, driver notifies wpa_supplicant using
> cfg80211_p2p_find_notify_end()
>
> All driver to user space communication done through nl80211 layer.
>
> Offloaded P2P find does not support variations like progressive scan.
>
> Signed-off-by: Vladimir Kondratiev <[email protected]>
> ---
> include/net/cfg80211.h | 60 +++++++++++++++
> include/uapi/linux/nl80211.h | 13 ++++
> net/wireless/nl80211.c | 167 ++++++++++++++++++++++++++++++++++++++++++
> net/wireless/rdev-ops.h | 19 +++++
> net/wireless/trace.h | 34 +++++++++
> 5 files changed, 293 insertions(+)
>
Hi Johannes,
Could you please comment on this patch status? I was under impression
I did all as we discussed and it is going to be merged, but maybe I
missed something. I was on long vacation.
Do you want me to rebase and resend?
Thanks, Vladimir
On Thu, 2013-04-11 at 13:10 +0300, Vladimir Kondratiev wrote:
> > For the wiphy size limitation thing, you need to put this into
> >
> > if (split) {
> > CMD(...)
> > CMD(...)
> > }
> OK, so do I need to handle this 'if (split)' or you will do so?
Please do. I'll handle the conflict later.
> > I think we (Intel) would also require to use the P2P_DEVICE for this
> > call, so maybe we should document in the nl80211 command that if
> > P2P_DEVICE is supported, this command is only supported on the
> > _P2P_DEVICE and not on _STATION? Anyway that'd be my assumption
> right
> > now that it gets used on whichever is used for P2P Device
> functionality,
> > so that shouldn't change anything in the supplicant just clarify the
> API
> > a bit.
> I see now similar functionality called in _STATION mode. Do we need
> supplicant
> changes for this? What is the concept with iftype, when device
> becoming
> _P2P_DEVICE - when discovery started or just before group formation?
> I can't draw conclusion looking on other driver's code. Is there some
> guide?
Well, I'll have to elaborate a bit.
So right now, P2P-Device functionality is implemented over the station
interface (typically "wlan0"). This means that the P2P Device address is
always the same as the wlan0 interface address, which is one reason for
wanting to change it. Another is that internal handling, at least in our
driver, becomes quite a bit simpler when the P2P_DEVICE
"interface" (doesn't have a netdev) is exposed in this way.
There are some patches from David Spinadel for wpa_supplicant on the way
to make it create and use a P2P_DEVICE virtual interface (wdev) for use
for all P2P functionality. This interface can also be assigned a
separate MAC address, which is then the P2P Device address.
At that point, drivers that support P2P_DEVICE functionality should use
only that wdev for P2P-Device related functionality (discovery, GO
negotiation, ...)
> > Btw, do you have supplicant patches already?
> I had initial discussion with Jouni about this design; but no patches
> yet.
Ok, I'd be interested in this -- particularly because we're also (more
even) interested in offloading the extended listen phase for timing and
power consumption reasons.
> > Is there value in supporting this call w/o any frequencies set? It
> seems
> > to me that the driver would be confused if it got no channels at
> all?
>
> I assume no frequences is "all supported", as for scan. In this case,
> "all supported social channels"
Does that make much sense? For scan I think this makes more sense, but
as the social channels are pretty much fixed I'd say it doesn't? OTOH, I
guess they differ for 60 GHz...
Note that this also works differently -- for scan cfg80211 builds the
channel list while here you don't, so you need to be very careful in the
driver about this. For that reason I'd prefer cfg80211 to build the
list, or just reject an empty one.
Btw, since only social channels are used etc. should we really ignore
channels that aren't supported, rather than rejecting them?
> Like say that passing empty array is same as not passing array at all?
> I thought that if one passes array of frequencies, it says "use only
> this"
> like caller know what to do; and in this case I'd reject empty list.
Yeah, this makes some sense. The part I'm not sure about is not passing
anything, see above.
johannes
On Thu, 2013-03-21 at 13:06 +0200, Vladimir Kondratiev wrote:
> Allow to implement P2P find phase in the driver/firmware.
>
> Offload scheme designed as follows:
>
> - Driver provide methods start_p2p_find and stop_p2p_find in the cfg80211_ops;
> - Driver indicate firmware or driver responds to the probe requests by setting
> feature NL80211_FEATURE_P2P_PROBE_RESP_OFFLOAD
> - wpa_supplicant analyses methods supported to discover p2p offload support;
> - wpa_supplicant analyses feature flags to discover p2p probe response
> offload support;
> to perform p2p scan, wpa_supplicant:
> - perform legacy scan, through driver's cfg80211_ops 'scan' method
> - configure rx management filter to get probe-request and probe-response frames
> - start p2p find via driver's cfg80211_ops start_p2p_find method
> - driver start p2p find with hardware and notify wpa_supplicant with
> cfg80211_p2p_find_notify_start()
> - driver/firmware toggle search/listen states. Received probe-request and
> probe-response frames passed to the wpa_supplicant via cfg80211_rx_mgmt
> - when wpa_supplicant wants to stop p2p find, it calls driver's
> cfg80211_ops stop_p2p_find method. Alternatively, driver/firmware may decide
> to stop p2p find. In all cases, driver notifies wpa_supplicant using
> cfg80211_p2p_find_notify_end()
>
> All driver to user space communication done through nl80211 layer.
>
> Offloaded P2P find does not support variations like progressive scan.
Ok :)
I have a conceptual question: As I understand it, this is going to be
required, ie. the device might not support P2P Find using
remain-on-channel, if this offload is supported. Right?
> +/**
> + * cfg80211_p2p_find_notify_end - report p2p find phase ended
> + * @wdev: the wireless device reporting the event
> + * @gfp: allocation flags
> + *
> + * p2p find phase may be ended either unsolicited or in response to
> + * ops->p2p_stop_find
Does that mean if the p2p_stop_find operation is called, this must also
be called? I'm guessing so, but it'd be good to spell it out explicitly.
> + * @NL80211_ATTR_MIN_DISCOVERABLE_INTERVAL:
> + * @NL80211_ATTR_MAX_DISCOVERABLE_INTERVAL: min/max discoverable interval
> + * for the p2p find, represented as u32
Could you please also say here that it's a multiple of 100 TUs?
> @@ -1417,6 +1419,8 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
> }
> CMD(start_p2p_device, START_P2P_DEVICE);
> CMD(set_mcast_rate, SET_MCAST_RATE);
> + CMD(start_p2p_find, START_P2P_FIND);
> + CMD(stop_p2p_find, STOP_P2P_FIND);
For the wiphy size limitation thing, you need to put this into
if (split) {
CMD(...)
CMD(...)
}
There's another patch pending that would then conflict here, but I can
sort out that problem.
> +static int nl80211_start_p2p_find(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];
> + struct wiphy *wiphy = &rdev->wiphy;
> + struct cfg80211_p2p_find_params params = {};
> + struct nlattr *attr_freq = info->attrs[NL80211_ATTR_SCAN_FREQUENCIES];
> + struct nlattr *attr;
> + int err, tmp, n_channels, i = 0;
> + struct ieee80211_channel **channels = NULL;
> +
> + switch (wdev->iftype) {
> + case NL80211_IFTYPE_P2P_DEVICE:
> + case NL80211_IFTYPE_STATION:
I think we (Intel) would also require to use the P2P_DEVICE for this
call, so maybe we should document in the nl80211 command that if
P2P_DEVICE is supported, this command is only supported on the
_P2P_DEVICE and not on _STATION? Anyway that'd be my assumption right
now that it gets used on whichever is used for P2P Device functionality,
so that shouldn't change anything in the supplicant just clarify the API
a bit.
Btw, do you have supplicant patches already?
> + if (attr_freq) {
Is there value in supporting this call w/o any frequencies set? It seems
to me that the driver would be confused if it got no channels at all?
> + n_channels = validate_scan_freqs(attr_freq);
> + if (!n_channels)
> + return -EINVAL;
> +
> + channels = kzalloc(n_channels * sizeof(*channels), GFP_KERNEL);
> + if (!channels)
> + return -ENOMEM;
> +
> + /* user specified, bail out if channel not found */
> + nla_for_each_nested(attr, attr_freq, tmp) {
> + struct ieee80211_channel *chan;
> +
> + chan = ieee80211_get_channel(wiphy, nla_get_u32(attr));
> +
> + if (!chan)
> + return -EINVAL;
This leaks memory, no?
> + if (!i) {
> + err = -EINVAL;
> + goto out_free;
> + }
And here you refuse an empty channel list, but a not-present one still
got accepted above, I think you should change that (which also saves you
a level of indentation here :P)
> + 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)
> +);
I think it'd be worthwhile to trace a bit more data, like the timings
for example? Maybe not the IEs and channel list (those are tricky
anyway), but the easy ones?
johannes