Return-path: Received: from nick.hrz.tu-chemnitz.de ([134.109.228.11]:35784 "EHLO nick.hrz.tu-chemnitz.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752471Ab3FNMPi (ORCPT ); Fri, 14 Jun 2013 08:15:38 -0400 From: Simon Wunderlich To: Johannes Berg Cc: linux-wireless@vger.kernel.org, Simon Wunderlich , Mathias Kretschmer Subject: [PATCHv2 2/5] nl80211/cfg80211: add channel switch command Date: Fri, 14 Jun 2013 14:15:20 +0200 Message-Id: <1371212124-26264-3-git-send-email-siwu@hrz.tu-chemnitz.de> (sfid-20130614_141543_215151_BE386295) In-Reply-To: <1371212124-26264-1-git-send-email-siwu@hrz.tu-chemnitz.de> References: <1371212124-26264-1-git-send-email-siwu@hrz.tu-chemnitz.de> Sender: linux-wireless-owner@vger.kernel.org List-ID: To allow channel switch announcements within beacons, add the channel switch command to nl80211/cfg80211. This is implementation is intended for AP and (later) IBSS mode. Signed-off-by: Simon Wunderlich Signed-off-by: Mathias Kretschmer --- Changes to RFCv1: * accept and pass CSA IEs and after-change IEs * use parameter structure instead of individual parameters --- include/net/cfg80211.h | 26 ++++++++++ include/uapi/linux/nl80211.h | 29 +++++++++++ net/wireless/nl80211.c | 118 +++++++++++++++++++++++++++++++++++++++++- 3 files changed, 172 insertions(+), 1 deletion(-) diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index 3c3a563..0de5384 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -610,6 +610,29 @@ struct cfg80211_ap_settings { bool radar_required; }; +/* struct cfg80211_csa_settings - channel switch settings + * + * Used for channel switch + * + * @chandef: defines the channel to use after the switch + * @beacon_csa: beacon data while performing the switch + * @counter_offset_beacon: offset for the counter within the beacon (tail) + * @counter_offset_presp: offset for the counter within the probe response + * @beacon_after: beacon data to be used on the new channel + * @radar_required: whether radar detection is required on the new channel + * @block_tx: whether transmissions should be blocked while changing + * @count: number of beacons until switch + */ +struct cfg80211_csa_settings { + struct cfg80211_chan_def chandef; + struct cfg80211_beacon_data beacon_csa; + u16 counter_offset_beacon, counter_offset_presp; + struct cfg80211_beacon_data beacon_after; + bool radar_required; + bool block_tx; + u8 count; +}; + /** * enum station_parameters_apply_mask - station parameter values to apply * @STATION_PARAM_APPLY_UAPSD: apply new uAPSD parameters (uapsd_queues, max_sp) @@ -2278,6 +2301,9 @@ struct cfg80211_ops { u16 duration); void (*crit_proto_stop)(struct wiphy *wiphy, struct wireless_dev *wdev); + int (*channel_switch)(struct wiphy *wiphy, + struct net_device *dev, + struct cfg80211_csa_settings *params); }; /* diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h index ca6facf..ddf3b9e 100644 --- a/include/uapi/linux/nl80211.h +++ b/include/uapi/linux/nl80211.h @@ -648,6 +648,16 @@ * @NL80211_CMD_CRIT_PROTOCOL_STOP: Indicates the connection reliability can * return back to normal. * + * @NL80211_CMD_CHANNEL_SWITCH: Perform a channel switch by announcing the + * the new channel information (Channel Switch Announcement - CSA) + * in the beacon for some time (as defined in the + * %NL80211_ATTR_CH_SWITCH_COUNT parameter) and then change to the + * new channel. Userspace provides the new channel information (using + * %NL80211_ATTR_WIPHY_FREQ and the attributes determining channel + * width). %NL80211_ATTR_CH_SWITCH_BLOCK_TX may be supplied to inform + * other station that transmission must be blocked until the channel + * switch is complete. + * * @NL80211_CMD_MAX: highest used command number * @__NL80211_CMD_AFTER_LAST: internal use */ @@ -810,6 +820,7 @@ enum nl80211_commands { NL80211_CMD_CRIT_PROTOCOL_START, NL80211_CMD_CRIT_PROTOCOL_STOP, + NL80211_CMD_CHANNEL_SWITCH, /* add new commands above here */ /* used to define NL80211_CMD_MAX below */ @@ -1436,6 +1447,18 @@ enum nl80211_commands { * allowed to be used with the first @NL80211_CMD_SET_STATION command to * update a TDLS peer STA entry. * + * @NL80211_ATTR_CH_SWITCH_COUNT: u32 attribute specifying the number of TBTT's + * until the channel switch event. + * @NL80211_ATTR_CH_SWITCH_BLOCK_TX: flag attribute specifying that transmission + * must be blocked on the current channel (before the channel switch + * operation). + * @NL80211_ATTR_CSA_IES: Nested set of attributes containing the IE information + * for the time while performing a channel switch. + * @NL80211_ATTR_CSA_C_OFF_BEACON: Offset of the channel switch counter + * field in the beacons tail (%NL80211_ATTR_BEACON_TAIL). + * @NL80211_ATTR_CSA_C_OFF_PRESP: Offset of the channel switch counter + * field in the probe response (%NL80211_ATTR_PROBE_RESP). + * * @NL80211_ATTR_MAX: highest attribute number currently defined * @__NL80211_ATTR_AFTER_LAST: internal use */ @@ -1736,6 +1759,12 @@ enum nl80211_attrs { NL80211_ATTR_PEER_AID, + NL80211_ATTR_CH_SWITCH_COUNT, + NL80211_ATTR_CH_SWITCH_BLOCK_TX, + NL80211_ATTR_CSA_IES, + NL80211_ATTR_CSA_C_OFF_BEACON, + NL80211_ATTR_CSA_C_OFF_PRESP, + /* add attributes here, update the policy in nl80211.c */ __NL80211_ATTR_AFTER_LAST, diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 1c4f7da..d48a00d 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -349,6 +349,11 @@ static const struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] = { [NL80211_ATTR_IE_RIC] = { .type = NLA_BINARY, .len = IEEE80211_MAX_DATA_LEN }, [NL80211_ATTR_PEER_AID] = { .type = NLA_U16 }, + [NL80211_ATTR_CH_SWITCH_COUNT] = { .type = NLA_U32 }, + [NL80211_ATTR_CH_SWITCH_BLOCK_TX] = { .type = NLA_FLAG }, + [NL80211_ATTR_CSA_IES] = { .type = NLA_NESTED }, + [NL80211_ATTR_CSA_C_OFF_BEACON] = { .type = NLA_U16 }, + [NL80211_ATTR_CSA_C_OFF_PRESP] = { .type = NLA_U16 }, }; /* policy for the key attributes */ @@ -5540,6 +5545,109 @@ static int nl80211_start_radar_detection(struct sk_buff *skb, return err; } +static int nl80211_channel_switch(struct sk_buff *skb, + struct genl_info *info) +{ + struct cfg80211_registered_device *rdev = info->user_ptr[0]; + struct net_device *dev = info->user_ptr[1]; + struct wireless_dev *wdev = dev->ieee80211_ptr; + struct cfg80211_csa_settings params; + struct nlattr *csa_ies[NL80211_ATTR_MAX+1]; + u8 radar_detect_width = 0; + int err; + + if (!rdev->ops->channel_switch) + return -EOPNOTSUPP; + + /* may add IBSS support later */ + if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_AP && + dev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO) + return -EOPNOTSUPP; + + memset(¶ms, 0, sizeof(params)); + + if (!info->attrs[NL80211_ATTR_WIPHY_FREQ] || + !info->attrs[NL80211_ATTR_CH_SWITCH_COUNT]) + return -EINVAL; + + /* only important for AP, IBSS and mesh create IEs internally */ + if (!info->attrs[NL80211_ATTR_CSA_IES] || + !info->attrs[NL80211_ATTR_CSA_C_OFF_BEACON]) + return -EINVAL; + + /* useless if AP is not running */ + if (!wdev->beacon_interval) + return -EINVAL; + + params.count = nla_get_u32(info->attrs[NL80211_ATTR_CH_SWITCH_COUNT]); + + err = nl80211_parse_beacon(info->attrs, ¶ms.beacon_after); + if (err) + return err; + + err = nla_parse_nested(csa_ies, NL80211_ATTR_MAX, + info->attrs[NL80211_ATTR_CSA_IES], + nl80211_policy); + if (err) + return err; + + err = nl80211_parse_beacon(csa_ies, ¶ms.beacon_csa); + if (err) + return err; + + params.counter_offset_beacon = + nla_get_u16(info->attrs[NL80211_ATTR_CSA_C_OFF_BEACON]); + if (params.counter_offset_beacon > params.beacon_csa.tail_len) + return -EINVAL; + + /* sanity check - counter should be the same this should be the same */ + if (params.beacon_csa.tail[params.counter_offset_beacon] != + params.count) + return -EINVAL; + + if (info->attrs[NL80211_ATTR_CSA_C_OFF_PRESP]) { + params.counter_offset_presp = + nla_get_u16(info->attrs[NL80211_ATTR_CSA_C_OFF_PRESP]); + if (params.counter_offset_presp > + params.beacon_csa.probe_resp_len) + return -EINVAL; + + if (params.beacon_csa.probe_resp[params.counter_offset_presp] != + params.count) + return -EINVAL; + } + + err = nl80211_parse_chandef(rdev, info, ¶ms.chandef); + if (err) + return err; + + if (!cfg80211_reg_can_beacon(&rdev->wiphy, ¶ms.chandef)) + return -EINVAL; + + err = cfg80211_chandef_dfs_required(wdev->wiphy, ¶ms.chandef); + if (err < 0) + return err; + + if (err) + radar_detect_width = BIT(params.chandef.width); + else + radar_detect_width = 0; + + err = cfg80211_can_use_iftype_chan(rdev, wdev, wdev->iftype, + params.chandef.chan, + CHAN_MODE_SHARED, + radar_detect_width); + if (err) + return err; + + if (info->attrs[NL80211_ATTR_CH_SWITCH_BLOCK_TX]) + params.block_tx = true; + + err = rdev->ops->channel_switch(&rdev->wiphy, dev, ¶ms); + + return err; +} + static int nl80211_send_bss(struct sk_buff *msg, struct netlink_callback *cb, u32 seq, int flags, struct cfg80211_registered_device *rdev, @@ -8995,7 +9103,15 @@ static struct genl_ops nl80211_ops[] = { .flags = GENL_ADMIN_PERM, .internal_flags = NL80211_FLAG_NEED_WDEV_UP | NL80211_FLAG_NEED_RTNL, - } + }, + { + .cmd = NL80211_CMD_CHANNEL_SWITCH, + .doit = nl80211_channel_switch, + .policy = nl80211_policy, + .flags = GENL_ADMIN_PERM, + .internal_flags = NL80211_FLAG_NEED_NETDEV_UP | + NL80211_FLAG_NEED_RTNL, + }, }; static struct genl_multicast_group nl80211_mlme_mcgrp = { -- 1.7.10.4