On Fri, Feb 10, 2012 at 12:53 AM, Luis R. Rodriguez
<mcgrof@xxxxxxxxxxxxx> wrote:
> On Thu, Jan 26, 2012 at 4:38 AM, Victor Goldenshtein <victorg@xxxxxx> wrote:
>> Add new NL80211_CMD_AP_CHANNEL_SWITCH command which
>> triggers a channel switch process, this command also
>> notifies usermode about channel switch complete event.
>>
>> Signed-off-by: Victor Goldenshtein <victorg@xxxxxx>
>> ---
>> include/linux/nl80211.h | 23 +++++++++++++
>> include/net/cfg80211.h | 16 +++++++++
>> net/wireless/mlme.c | 11 ++++++
>> net/wireless/nl80211.c | 80 +++++++++++++++++++++++++++++++++++++++++++++++
>> net/wireless/nl80211.h | 4 ++
>> 5 files changed, 134 insertions(+), 0 deletions(-)
>>
>> diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
>> index b45ceb1..8a004fc 100644
>> --- a/include/linux/nl80211.h
>> +++ b/include/linux/nl80211.h
>> @@ -551,6 +551,15 @@
>> * radar interference is detected during this period the dfs master may
>> * initiate the tx.
>> *
>> + * @NL80211_CMD_AP_CHANNEL_SWITCH: Perform a channel switch in the driver (for
>> + * AP/GO).
>> + * %NL80211_ATTR_WIPHY_FREQ: new channel frequency.
>> + * %NL80211_ATTR_CH_SWITCH_BLOCK_TX: block tx on the current channel.
>> + * %NL80211_ATTR_CH_SWITCH_POST_BLOCK_TX: block tx on the target channel.
>
> This is left as optional. It would be good to explain why this is
> option and/or why userspace would set this
> NL80211_ATTR_CH_SWITCH_POST_BLOCK_TX flag or not.
>
>> diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
>> @@ -4072,6 +4075,39 @@ static int nl80211_dfs_en_tx(struct sk_buff *skb, struct genl_info *info)
>> return rdev->ops->dfs_en_tx(&rdev->wiphy, dev);
>> }
>>
>> +static int nl80211_ap_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];
>> + u32 freq = 0, count = 0, post_switch_block_tx = 0, block_tx = 0;
>
> Please use bool for flags.
>
ok.
>> +
>> + ASSERT_RDEV_LOCK(rdev);
>> +
>> + if (!rdev->ops->ap_channel_switch)
>> + return -EOPNOTSUPP;
>> +
>> + if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_AP &&
>> + dev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO)
>> + return -EOPNOTSUPP;
>
> If we want to restrict this command from userspace to only be able to
> issue a channel switch for DFS we need to consider some additional
> sanity checks here. It may be worth adding a small state machine to
> cfg80211 for the device and only allow certain of these commands for
> specific DFS states, if these commands are to be used only on DFS
> states. This would limit the stupidities that userspace can put
> cfg80211 into.
>
DFS implementation in driver has only one state - DFS_CAC_IN_PROGRESS,
so I"m not sure we need here a state machine but some sanity checks
will be added in the next RFC.
--
Thanks,
Victor.
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