Return-path: Received: from cora.hrz.tu-chemnitz.de ([134.109.228.40]:47978 "EHLO cora.hrz.tu-chemnitz.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751936Ab3GHNO1 (ORCPT ); Mon, 8 Jul 2013 09:14:27 -0400 From: Simon Wunderlich To: Johannes Berg Cc: linux-wireless@vger.kernel.org, Mathias Kretschmer , Simon Wunderlich Subject: [PATCHv3 1/5] nl80211/cfg80211: add channel switch command Date: Mon, 8 Jul 2013 15:14:06 +0200 Message-Id: <1373289250-12259-2-git-send-email-siwu@hrz.tu-chemnitz.de> (sfid-20130708_151442_636506_87F50EC9) In-Reply-To: <1373289250-12259-1-git-send-email-siwu@hrz.tu-chemnitz.de> References: <1373289250-12259-1-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 PATCHv2: * define csa_ies as static to save stack size * add wiphy flag and cmd for channel_switch * move NL80211_ATTR_CSA_C_OFF_BEACON into csa_ies Changes to RFCv1: * accept and pass CSA IEs and after-change IEs * use parameter structure instead of individual parameters --- include/net/cfg80211.h | 30 ++++++++++ include/uapi/linux/nl80211.h | 29 ++++++++++ net/wireless/nl80211.c | 126 +++++++++++++++++++++++++++++++++++++++++- 3 files changed, 184 insertions(+), 1 deletion(-) diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index 4940960..249ac42 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -639,6 +639,30 @@ struct cfg80211_ap_settings { }; /** + * 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) * @STATION_PARAM_APPLY_CAPABILITY: apply new capability @@ -2311,6 +2335,9 @@ 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); }; /* @@ -2376,6 +2403,8 @@ struct cfg80211_ops { * @WIPHY_FLAG_OFFCHAN_TX: Device supports direct off-channel TX. * @WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL: Device supports remain-on-channel call. * @WIPHY_FLAG_SUPPORTS_5_10_MHZ: Device supports 5 MHz and 10 MHz channels. + * @WIPHY_FLAG_HAS_CHANNEL_SWITCH_BEACON: Device supports channel switch in + * beaconing mode (AP, IBSS, Mesh, ...). */ enum wiphy_flags { WIPHY_FLAG_CUSTOM_REGULATORY = BIT(0), @@ -2400,6 +2429,7 @@ enum wiphy_flags { WIPHY_FLAG_OFFCHAN_TX = BIT(20), WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL = BIT(21), WIPHY_FLAG_SUPPORTS_5_10_MHZ = BIT(22), + WIPHY_FLAG_HAS_CHANNEL_SWITCH = BIT(23), }; /** diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h index de0ce80..4049cb8 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 be64cd4..4e86a56 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 */ @@ -1393,6 +1398,8 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, if (state->split) { CMD(crit_proto_start, CRIT_PROTOCOL_START); CMD(crit_proto_stop, CRIT_PROTOCOL_STOP); + if (dev->wiphy.flags & WIPHY_FLAG_HAS_CHANNEL_SWITCH) + CMD(channel_switch, CHANNEL_SWITCH); } #ifdef CONFIG_NL80211_TESTMODE @@ -5576,6 +5583,115 @@ 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; + /* csa_ies is defined static to avoid waste of stack size - this + * function is called under RTNL lock, so this should not be a problem. + */ + static struct nlattr *csa_ies[NL80211_ATTR_MAX+1]; + u8 radar_detect_width = 0; + int err; + + if (!rdev->ops->channel_switch || + !(rdev->wiphy.flags & WIPHY_FLAG_HAS_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]) + 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; + + if (!csa_ies[NL80211_ATTR_CSA_C_OFF_BEACON]) + return -EINVAL; + + params.counter_offset_beacon = + nla_get_u16(csa_ies[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 (csa_ies[NL80211_ATTR_CSA_C_OFF_PRESP]) { + params.counter_offset_presp = + nla_get_u16(csa_ies[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, @@ -9048,7 +9164,15 @@ 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