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Commit 61fa713c authored by Holger Schurig's avatar Holger Schurig Committed by John W. Linville
Browse files

cfg80211: return channel noise via survey API 



This patch implements the NL80211_CMD_GET_SURVEY command and an get_survey()
ops that a driver can implement. The goal of this command is to allow a
drivers to report channel survey data (e.g. channel noise, channel
occupation).

For now, only the mechanism to report back channel noise has been
implemented.

In future, there will either be a survey-trigger command --- or the existing
scan-trigger command will be enhanced. This will allow user-space to
request survey for arbitrary channels.

Note: any driver that cannot report channel noise should not report
any value at all, e.g. made-up -92 dBm.

Signed-off-by: default avatarHolger Schurig <holgerschurig@gmail.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent a043897a

include/linux/nl80211.h

+34 −0
Original line number Diff line number Diff line
@@ -160,6 +160,11 @@ 
 * @NL80211_CMD_SCAN_ABORTED: scan was aborted, for unspecified reasons,

 *	partial scan results may be available

 *

 * @NL80211_CMD_GET_SURVEY: get survey resuls, e.g. channel occupation

 *      or noise level

 * @NL80211_CMD_NEW_SURVEY_RESULTS: survey data notification (as a reply to

 *	NL80211_CMD_GET_SURVEY and on the "scan" multicast group)

 *

 * @NL80211_CMD_REG_CHANGE: indicates to userspace the regulatory domain

 * 	has been changed and provides details of the request information

 * 	that caused the change such as who initiated the regulatory request
@@ -341,6 +346,9 @@ enum nl80211_commands { 


	NL80211_CMD_SET_WIPHY_NETNS,



	NL80211_CMD_GET_SURVEY,

	NL80211_CMD_NEW_SURVEY_RESULTS,



	/* add new commands above here */



	/* used to define NL80211_CMD_MAX below */
@@ -586,6 +594,10 @@ enum nl80211_commands { 
 *

 * @NL80211_ATTR_4ADDR: Use 4-address frames on a virtual interface

 *

 * @NL80211_ATTR_SURVEY_INFO: survey information about a channel, part of

 *      the survey response for %NL80211_CMD_GET_SURVEY, nested attribute

 *      containing info as possible, see &enum survey_info.

 *

 * @NL80211_ATTR_MAX: highest attribute number currently defined

 * @__NL80211_ATTR_AFTER_LAST: internal use

 */
@@ -718,6 +730,8 @@ enum nl80211_attrs { 


	NL80211_ATTR_4ADDR,



	NL80211_ATTR_SURVEY_INFO,



	/* add attributes here, update the policy in nl80211.c */



	__NL80211_ATTR_AFTER_LAST,
@@ -1120,6 +1134,26 @@ enum nl80211_reg_rule_flags { 
	NL80211_RRF_NO_IBSS		= 1<<8,

};



/**

 * enum nl80211_survey_info - survey information

 *

 * These attribute types are used with %NL80211_ATTR_SURVEY_INFO

 * when getting information about a survey.

 *

 * @__NL80211_SURVEY_INFO_INVALID: attribute number 0 is reserved

 * @NL80211_SURVEY_INFO_FREQUENCY: center frequency of channel

 * @NL80211_SURVEY_INFO_NOISE: noise level of channel (u8, dBm)

 */

enum nl80211_survey_info {

	__NL80211_SURVEY_INFO_INVALID,

	NL80211_SURVEY_INFO_FREQUENCY,

	NL80211_SURVEY_INFO_NOISE,



	/* keep last */

	__NL80211_SURVEY_INFO_AFTER_LAST,

	NL80211_SURVEY_INFO_MAX = __NL80211_SURVEY_INFO_AFTER_LAST - 1

};



/**

 * enum nl80211_mntr_flags - monitor configuration flags

 *

include/net/cfg80211.h

+34 −0
Original line number Diff line number Diff line
@@ -234,6 +234,35 @@ struct key_params { 
	u32 cipher;

};



/**

 * enum survey_info_flags - survey information flags

 *

 * Used by the driver to indicate which info in &struct survey_info

 * it has filled in during the get_survey().

 */

enum survey_info_flags {

	SURVEY_INFO_NOISE_DBM = 1<<0,

};



/**

 * struct survey_info - channel survey response

 *

 * Used by dump_survey() to report back per-channel survey information.

 *

 * @channel: the channel this survey record reports, mandatory

 * @filled: bitflag of flags from &enum survey_info_flags

 * @noise: channel noise in dBm. This and all following fields are

 *     optional

 *

 * This structure can later be expanded with things like

 * channel duty cycle etc.

 */

struct survey_info {

	struct ieee80211_channel *channel;

	u32 filled;

	s8 noise;

};



/**

 * struct beacon_parameters - beacon parameters

 *
@@ -944,6 +973,8 @@ struct cfg80211_bitrate_mask { 
 * @rfkill_poll: polls the hw rfkill line, use cfg80211 reporting

 *	functions to adjust rfkill hw state

 *

 * @dump_survey: get site survey information.

 *

 * @testmode_cmd: run a test mode command

 */

struct cfg80211_ops {
@@ -1063,6 +1094,9 @@ struct cfg80211_ops { 
				    const u8 *peer,

				    const struct cfg80211_bitrate_mask *mask);



	int	(*dump_survey)(struct wiphy *wiphy, struct net_device *netdev,

			int idx, struct survey_info *info);



	/* some temporary stuff to finish wext */

	int	(*set_power_mgmt)(struct wiphy *wiphy, struct net_device *dev,

				  bool enabled, int timeout);

net/wireless/nl80211.c

+105 −0
Original line number Diff line number Diff line
@@ -3245,6 +3245,106 @@ static int nl80211_dump_scan(struct sk_buff *skb, 
	return err;

}



static int nl80211_send_survey(struct sk_buff *msg, u32 pid, u32 seq,

				int flags, struct net_device *dev,

				struct survey_info *survey)

{

	void *hdr;

	struct nlattr *infoattr;



	/* Survey without a channel doesn't make sense */

	if (!survey->channel)

		return -EINVAL;



	hdr = nl80211hdr_put(msg, pid, seq, flags,

			     NL80211_CMD_NEW_SURVEY_RESULTS);

	if (!hdr)

		return -ENOMEM;



	NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, dev->ifindex);



	infoattr = nla_nest_start(msg, NL80211_ATTR_SURVEY_INFO);

	if (!infoattr)

		goto nla_put_failure;



	NLA_PUT_U32(msg, NL80211_SURVEY_INFO_FREQUENCY,

		    survey->channel->center_freq);

	if (survey->filled & SURVEY_INFO_NOISE_DBM)

		NLA_PUT_U8(msg, NL80211_SURVEY_INFO_NOISE,

			    survey->noise);



	nla_nest_end(msg, infoattr);



	return genlmsg_end(msg, hdr);



 nla_put_failure:

	genlmsg_cancel(msg, hdr);

	return -EMSGSIZE;

}



static int nl80211_dump_survey(struct sk_buff *skb,

			struct netlink_callback *cb)

{

	struct survey_info survey;

	struct cfg80211_registered_device *dev;

	struct net_device *netdev;

	int ifidx = cb->args[0];

	int survey_idx = cb->args[1];

	int res;



	if (!ifidx)

		ifidx = nl80211_get_ifidx(cb);

	if (ifidx < 0)

		return ifidx;

	cb->args[0] = ifidx;



	rtnl_lock();



	netdev = __dev_get_by_index(sock_net(skb->sk), ifidx);

	if (!netdev) {

		res = -ENODEV;

		goto out_rtnl;

	}



	dev = cfg80211_get_dev_from_ifindex(sock_net(skb->sk), ifidx);

	if (IS_ERR(dev)) {

		res = PTR_ERR(dev);

		goto out_rtnl;

	}



	if (!dev->ops->dump_survey) {

		res = -EOPNOTSUPP;

		goto out_err;

	}



	while (1) {

		res = dev->ops->dump_survey(&dev->wiphy, netdev, survey_idx,

					    &survey);

		if (res == -ENOENT)

			break;

		if (res)

			goto out_err;



		if (nl80211_send_survey(skb,

				NETLINK_CB(cb->skb).pid,

				cb->nlh->nlmsg_seq, NLM_F_MULTI,

				netdev,

				&survey) < 0)

			goto out;

		survey_idx++;

	}



 out:

	cb->args[1] = survey_idx;

	res = skb->len;

 out_err:

	cfg80211_unlock_rdev(dev);

 out_rtnl:

	rtnl_unlock();



	return res;

}



static bool nl80211_valid_auth_type(enum nl80211_auth_type auth_type)

{

	return auth_type <= NL80211_AUTHTYPE_MAX;
@@ -4322,6 +4422,11 @@ static struct genl_ops nl80211_ops[] = { 
		.policy = nl80211_policy,

		.flags = GENL_ADMIN_PERM,

	},

	{

		.cmd = NL80211_CMD_GET_SURVEY,

		.policy = nl80211_policy,

		.dumpit = nl80211_dump_survey,

	},

};

static struct genl_multicast_group nl80211_mlme_mcgrp = {

	.name = "mlme",