nl80211/cfg80211: add channel switch command

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 <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Simon Wunderlich 2013-07-11 16:09:05 +02:00 committed by Johannes Berg
parent 7cf1f14ecf
commit 16ef1fe272
5 changed files with 229 additions and 1 deletions

View File

@ -665,6 +665,30 @@ 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)
@ -2139,6 +2163,8 @@ struct cfg80211_update_ft_ies_params {
* @crit_proto_stop: Indicates critical protocol no longer needs increased link
* reliability. This operation can not fail.
* @set_coalesce: Set coalesce parameters.
*
* @channel_switch: initiate channel-switch procedure (with CSA)
*/
struct cfg80211_ops {
int (*suspend)(struct wiphy *wiphy, struct cfg80211_wowlan *wow);
@ -2376,6 +2402,10 @@ struct cfg80211_ops {
struct wireless_dev *wdev);
int (*set_coalesce)(struct wiphy *wiphy,
struct cfg80211_coalesce *coalesce);
int (*channel_switch)(struct wiphy *wiphy,
struct net_device *dev,
struct cfg80211_csa_settings *params);
};
/*
@ -2441,6 +2471,8 @@ 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: Device supports channel switch in
* beaconing mode (AP, IBSS, Mesh, ...).
*/
enum wiphy_flags {
WIPHY_FLAG_CUSTOM_REGULATORY = BIT(0),
@ -2465,6 +2497,7 @@ 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),
};
/**

View File

@ -676,6 +676,16 @@
* @NL80211_CMD_GET_COALESCE: Get currently supported coalesce rules.
* @NL80211_CMD_SET_COALESCE: Configure coalesce rules or clear existing rules.
*
* @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
*/
@ -841,6 +851,8 @@ enum nl80211_commands {
NL80211_CMD_GET_COALESCE,
NL80211_CMD_SET_COALESCE,
NL80211_CMD_CHANNEL_SWITCH,
/* add new commands above here */
/* used to define NL80211_CMD_MAX below */
@ -1469,6 +1481,18 @@ enum nl80211_commands {
*
* @NL80211_ATTR_COALESCE_RULE: Coalesce rule information.
*
* @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
*/
@ -1771,6 +1795,12 @@ enum nl80211_attrs {
NL80211_ATTR_COALESCE_RULE,
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,

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@ -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 */
@ -1422,6 +1427,8 @@ 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
@ -5613,6 +5620,111 @@ 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_attrs 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_attrs[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(&params, 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, &params.beacon_after);
if (err)
return err;
err = nla_parse_nested(csa_attrs, NL80211_ATTR_MAX,
info->attrs[NL80211_ATTR_CSA_IES],
nl80211_policy);
if (err)
return err;
err = nl80211_parse_beacon(csa_attrs, &params.beacon_csa);
if (err)
return err;
if (!csa_attrs[NL80211_ATTR_CSA_C_OFF_BEACON])
return -EINVAL;
params.counter_offset_beacon =
nla_get_u16(csa_attrs[NL80211_ATTR_CSA_C_OFF_BEACON]);
if (params.counter_offset_beacon >= params.beacon_csa.tail_len)
return -EINVAL;
/* sanity check - counters should be the same */
if (params.beacon_csa.tail[params.counter_offset_beacon] !=
params.count)
return -EINVAL;
if (csa_attrs[NL80211_ATTR_CSA_C_OFF_PRESP]) {
params.counter_offset_presp =
nla_get_u16(csa_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, &params.chandef);
if (err)
return err;
if (!cfg80211_reg_can_beacon(&rdev->wiphy, &params.chandef))
return -EINVAL;
err = cfg80211_chandef_dfs_required(wdev->wiphy, &params.chandef);
if (err < 0) {
return err;
} else if (err) {
radar_detect_width = BIT(params.chandef.width);
params.radar_required = true;
}
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;
return rdev_channel_switch(rdev, dev, &params);
}
static int nl80211_send_bss(struct sk_buff *msg, struct netlink_callback *cb,
u32 seq, int flags,
struct cfg80211_registered_device *rdev,
@ -9361,7 +9473,15 @@ static struct genl_ops nl80211_ops[] = {
.flags = GENL_ADMIN_PERM,
.internal_flags = NL80211_FLAG_NEED_WIPHY |
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 = {

View File

@ -923,4 +923,16 @@ static inline void rdev_crit_proto_stop(struct cfg80211_registered_device *rdev,
trace_rdev_return_void(&rdev->wiphy);
}
static inline int rdev_channel_switch(struct cfg80211_registered_device *rdev,
struct net_device *dev,
struct cfg80211_csa_settings *params)
{
int ret;
trace_rdev_channel_switch(&rdev->wiphy, dev, params);
ret = rdev->ops->channel_switch(&rdev->wiphy, dev, params);
trace_rdev_return_int(&rdev->wiphy, ret);
return ret;
}
#endif /* __CFG80211_RDEV_OPS */

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@ -1841,6 +1841,39 @@ TRACE_EVENT(rdev_crit_proto_stop,
WIPHY_PR_ARG, WDEV_PR_ARG)
);
TRACE_EVENT(rdev_channel_switch,
TP_PROTO(struct wiphy *wiphy, struct net_device *netdev,
struct cfg80211_csa_settings *params),
TP_ARGS(wiphy, netdev, params),
TP_STRUCT__entry(
WIPHY_ENTRY
NETDEV_ENTRY
CHAN_DEF_ENTRY
__field(u16, counter_offset_beacon)
__field(u16, counter_offset_presp)
__field(bool, radar_required)
__field(bool, block_tx)
__field(u8, count)
),
TP_fast_assign(
WIPHY_ASSIGN;
NETDEV_ASSIGN;
CHAN_DEF_ASSIGN(&params->chandef);
__entry->counter_offset_beacon = params->counter_offset_beacon;
__entry->counter_offset_presp = params->counter_offset_presp;
__entry->radar_required = params->radar_required;
__entry->block_tx = params->block_tx;
__entry->count = params->count;
),
TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT ", " CHAN_DEF_PR_FMT
", block_tx: %d, count: %u, radar_required: %d"
", counter offsets (beacon/presp): %u/%u",
WIPHY_PR_ARG, NETDEV_PR_ARG, CHAN_DEF_PR_ARG,
__entry->block_tx, __entry->count, __entry->radar_required,
__entry->counter_offset_beacon,
__entry->counter_offset_presp)
);
/*************************************************************
* cfg80211 exported functions traces *
*************************************************************/