From 61fa713c751683da915fa0c1aa502be85822c357 Mon Sep 17 00:00:00 2001 From: Holger Schurig Date: Wed, 11 Nov 2009 12:25:40 +0100 Subject: [PATCH] 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 Signed-off-by: John W. Linville --- include/linux/nl80211.h | 34 ++++++++++++++++ include/net/cfg80211.h | 34 ++++++++++++++++ net/wireless/nl80211.c | 105 ++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 173 insertions(+) diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h index d2f276de9abe..45db17f81aa3 100644 --- a/include/linux/nl80211.h +++ b/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 @@ 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, @@ -1121,6 +1135,26 @@ enum nl80211_reg_rule_flags { }; /** + * 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 * * Monitor configuration flags. diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index 0e4c51fc63e5..21710fc17eaf 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -235,6 +235,35 @@ struct key_params { }; /** + * 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 * * Used to configure the beacon for an interface. @@ -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); diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 4dc139cdba5c..5c8b3bfada4b 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -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", -- 2.11.0