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: Holger Schurig <holgerschurig@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Holger Schurig 2009-11-11 12:25:40 +01:00 committed by John W. Linville
parent a043897a31
commit 61fa713c75
3 changed files with 173 additions and 0 deletions

View File

@ -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
*

View File

@ -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);

View File

@ -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",