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
driver to report back channel survey data (e.g. channel noise, channel
occupation) back to cfg80211 and thus via nl80211 to user-space.
In future, they will either be a survey-trigger command --- or the existing
scan-trigger command will be enhanced. However, the get_survey() operation
is usable even in absence of this: a driver can report the channel noise in
mBm with the implemented mechanism.
get_survey() is currently modelled like get_key(). I hope that's right.
struct survey_info is modelled like struct station_info. This allows different
drivers to fill in different fields.
Signed-off-by: Holger Schurig <holgerschurig@xxxxxxxxx>
---
v2: * channel is mandatory (by way of callback-parameter)
* switched to .dump operation, e.g. nl80211_dump_survey() is now
similar to nl80211_dump_stations() and nl80211_send_survey()
is similar to nl80211_send_station().
* this also means that the cfg80211_ops dump_survey() now carries
an idx. A possible implementation (sketched, not compile-tested)
for libertas could be:
int lbs_dump_survey(struct wiphy *wiphy, struct net_device *netdev,
int idx, struct survey_info *info)
{
struct lbs_private *priv = wiphy_priv(wiphy);
if (idx != 0)
return -ENOENT;
info->channel = priv->channel;
info->filled = SURVEY_INFO_NOISE_MBM;
info->noise = CAL_NF(...);
return 0;
}
but other drives would use idx to iterate over stored survey information and
return the according information.
Johannes, this is so far only compile-, sparse- and checkpatch.pl tested. I
haven't yet added code to libertas and "iw", but this will be done ASAP.
I also wonder if I should add code to mac80211_hwsim to just report
back something, so that we have a hardware independend guinea pig :-)
--- linux-wl.orig/include/linux/nl80211.h
+++ linux-wl/include/linux/nl80211.h
@@ -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 @@
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 */
@@ -584,6 +592,11 @@
* changed then the list changed and the dump should be repeated
* completely from scratch.
*
+ * @NL80211_ATTR_SURVEY_NOISE: noise from survey in mBm
+ * @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
*/
@@ -714,6 +727,9 @@
NL80211_ATTR_PID,
+ NL80211_ATTR_SURVEY_NOISE,
+ NL80211_ATTR_SURVEY_INFO,
+
/* add attributes here, update the policy in nl80211.c */
__NL80211_ATTR_AFTER_LAST,
--- linux-wl.orig/include/net/cfg80211.h
+++ linux-wl/include/net/cfg80211.h
@@ -233,6 +233,35 @@
};
/**
+ * 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_MBM = 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 mBm. 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;
+ s32 noise;
+};
+
+/**
* struct beacon_parameters - beacon parameters
*
* Used to configure the beacon for an interface.
@@ -941,6 +970,8 @@
* @rfkill_poll: polls the hw rfkill line, use cfg80211 reporting
* functions to adjust rfkill hw state
*
+ * @dump_survey: get site survey information about.
+ *
* @testmode_cmd: run a test mode command
*/
struct cfg80211_ops {
@@ -1060,6 +1091,9 @@
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);
--- linux-wl.orig/net/wireless/nl80211.c
+++ linux-wl/net/wireless/nl80211.c
@@ -3229,6 +3229,101 @@
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 *surveyattr;
+
+ hdr = nl80211hdr_put(msg, pid, seq, flags,
+ NL80211_CMD_NEW_SURVEY_RESULTS);
+ if (!hdr)
+ return -1;
+
+ NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, dev->ifindex);
+
+ surveyattr = nla_nest_start(msg, NL80211_ATTR_SURVEY_INFO);
+ if (!surveyattr)
+ goto nla_put_failure;
+
+ if (nl80211_msg_put_channel(msg, survey->channel))
+ goto nla_put_failure;
+
+ if (survey->filled & SURVEY_INFO_NOISE_MBM)
+ NLA_PUT_U32(msg, NL80211_ATTR_SURVEY_NOISE,
+ survey->noise);
+ nla_nest_end(msg, surveyattr);
+
+ 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 err;
+
+ if (!ifidx)
+ ifidx = nl80211_get_ifidx(cb);
+ if (ifidx < 0)
+ return ifidx;
+
+ rtnl_lock();
+
+ netdev = __dev_get_by_index(sock_net(skb->sk), ifidx);
+ if (!netdev) {
+ err = -ENODEV;
+ goto out_rtnl;
+ }
+
+ dev = cfg80211_get_dev_from_ifindex(sock_net(skb->sk), ifidx);
+ if (IS_ERR(dev)) {
+ err = PTR_ERR(dev);
+ goto out_rtnl;
+ }
+
+ if (!dev->ops->dump_survey) {
+ err = -EOPNOTSUPP;
+ goto out_err;
+ }
+
+ while (1) {
+ err = dev->ops->dump_survey(&dev->wiphy, netdev, survey_idx,
+ &survey);
+ if (err == -ENOENT)
+ break;
+ if (err)
+ 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;
+ err = skb->len;
+ out_err:
+ cfg80211_unlock_rdev(dev);
+ out_rtnl:
+ rtnl_unlock();
+
+ return err;
+}
+
static bool nl80211_valid_auth_type(enum nl80211_auth_type auth_type)
{
return auth_type <= NL80211_AUTHTYPE_MAX;
@@ -4306,6 +4401,11 @@
.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",
--
http://www.holgerschurig.de
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