On Fri, 2011-01-07 at 14:26 +0900, Bruno Randolf wrote:
> Extend channel to frequency mapping for 802.11j Japan 4.9GHz band, according to
> IEEE802.11 section 17.3.8.3.2 and Annex J. Because there are now overlapping
> channel numbers in the 2GHz and 5GHz band we can't map from channel to
> frequency without knowing the band. This is no problem as in most contexts we
> know the band. In places where we don't know the band (and WEXT compatibility)
> we assume the 2GHz band for channels below 14.
>
> This patch does not implement all channel to frequency mappings defined in
> 802.11, it's just an extension for 802.11j 20MHz channels. 5MHz and 10MHz
> channels as well as 802.11y channels have been omitted.
Reviewed-by: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
> Signed-off-by: Bruno Randolf <br1@xxxxxxxxxxx>
> ---
> include/net/cfg80211.h | 3 ++-
> net/mac80211/ibss.c | 3 ++-
> net/mac80211/mesh.c | 2 +-
> net/mac80211/mlme.c | 8 +++++---
> net/mac80211/scan.c | 3 ++-
> net/wireless/reg.c | 6 +++---
> net/wireless/util.c | 36 ++++++++++++++++++++++--------------
> net/wireless/wext-compat.c | 5 ++++-
> 8 files changed, 41 insertions(+), 25 deletions(-)
>
> diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
> index bcc9f44..cfaac36 100644
> --- a/include/net/cfg80211.h
> +++ b/include/net/cfg80211.h
> @@ -1788,8 +1788,9 @@ static inline void *wdev_priv(struct wireless_dev *wdev)
> /**
> * ieee80211_channel_to_frequency - convert channel number to frequency
> * @chan: channel number
> + * @band: band, necessary due to channel number overlap
> */
> -extern int ieee80211_channel_to_frequency(int chan);
> +extern int ieee80211_channel_to_frequency(int chan, enum ieee80211_band band);
>
> /**
> * ieee80211_frequency_to_channel - convert frequency to channel number
> diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
> index 53c7077..775fb63 100644
> --- a/net/mac80211/ibss.c
> +++ b/net/mac80211/ibss.c
> @@ -270,7 +270,8 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
> enum ieee80211_band band = rx_status->band;
>
> if (elems->ds_params && elems->ds_params_len == 1)
> - freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
> + freq = ieee80211_channel_to_frequency(elems->ds_params[0],
> + band);
> else
> freq = rx_status->freq;
>
> diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
> index ca3af46..1430cdc 100644
> --- a/net/mac80211/mesh.c
> +++ b/net/mac80211/mesh.c
> @@ -574,7 +574,7 @@ static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
> &elems);
>
> if (elems.ds_params && elems.ds_params_len == 1)
> - freq = ieee80211_channel_to_frequency(elems.ds_params[0]);
> + freq = ieee80211_channel_to_frequency(elems.ds_params[0], band);
> else
> freq = rx_status->freq;
>
> diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
> index 45fbb9e..33bd6d4 100644
> --- a/net/mac80211/mlme.c
> +++ b/net/mac80211/mlme.c
> @@ -176,7 +176,7 @@ static u32 ieee80211_enable_ht(struct ieee80211_sub_if_data *sdata,
>
> /* check that channel matches the right operating channel */
> if (local->hw.conf.channel->center_freq !=
> - ieee80211_channel_to_frequency(hti->control_chan))
> + ieee80211_channel_to_frequency(hti->control_chan, sband->band))
> enable_ht = false;
>
> if (enable_ht) {
> @@ -429,7 +429,8 @@ void ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
> container_of((void *)bss, struct cfg80211_bss, priv);
> struct ieee80211_channel *new_ch;
> struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
> - int new_freq = ieee80211_channel_to_frequency(sw_elem->new_ch_num);
> + int new_freq = ieee80211_channel_to_frequency(sw_elem->new_ch_num,
> + cbss->channel->band);
>
> ASSERT_MGD_MTX(ifmgd);
>
> @@ -1519,7 +1520,8 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
> }
>
> if (elems->ds_params && elems->ds_params_len == 1)
> - freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
> + freq = ieee80211_channel_to_frequency(elems->ds_params[0],
> + rx_status->band);
> else
> freq = rx_status->freq;
>
> diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
> index fb274db..1ef73be 100644
> --- a/net/mac80211/scan.c
> +++ b/net/mac80211/scan.c
> @@ -196,7 +196,8 @@ ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
> ieee802_11_parse_elems(elements, skb->len - baselen, &elems);
>
> if (elems.ds_params && elems.ds_params_len == 1)
> - freq = ieee80211_channel_to_frequency(elems.ds_params[0]);
> + freq = ieee80211_channel_to_frequency(elems.ds_params[0],
> + rx_status->band);
> else
> freq = rx_status->freq;
>
> diff --git a/net/wireless/reg.c b/net/wireless/reg.c
> index 37693b6..c565689 100644
> --- a/net/wireless/reg.c
> +++ b/net/wireless/reg.c
> @@ -1801,9 +1801,9 @@ void regulatory_hint_disconnect(void)
>
> static bool freq_is_chan_12_13_14(u16 freq)
> {
> - if (freq == ieee80211_channel_to_frequency(12) ||
> - freq == ieee80211_channel_to_frequency(13) ||
> - freq == ieee80211_channel_to_frequency(14))
> + if (freq == ieee80211_channel_to_frequency(12, IEEE80211_BAND_2GHZ) ||
> + freq == ieee80211_channel_to_frequency(13, IEEE80211_BAND_2GHZ) ||
> + freq == ieee80211_channel_to_frequency(14, IEEE80211_BAND_2GHZ))
> return true;
> return false;
> }
> diff --git a/net/wireless/util.c b/net/wireless/util.c
> index 7620ae2..4ed065d 100644
> --- a/net/wireless/util.c
> +++ b/net/wireless/util.c
> @@ -29,29 +29,37 @@ ieee80211_get_response_rate(struct ieee80211_supported_band *sband,
> }
> EXPORT_SYMBOL(ieee80211_get_response_rate);
>
> -int ieee80211_channel_to_frequency(int chan)
> +int ieee80211_channel_to_frequency(int chan, enum ieee80211_band band)
> {
> - if (chan < 14)
> - return 2407 + chan * 5;
> -
> - if (chan == 14)
> - return 2484;
> -
> - /* FIXME: 802.11j 17.3.8.3.2 */
> - return (chan + 1000) * 5;
> + /* see 802.11 17.3.8.3.2 and Annex J
> + * there are overlapping channel numbers in 5GHz and 2GHz bands */
> + if (band == IEEE80211_BAND_5GHZ) {
> + if (chan >= 182 && chan <= 196)
> + return 4000 + chan * 5;
> + else
> + return 5000 + chan * 5;
> + } else { /* IEEE80211_BAND_2GHZ */
> + if (chan == 14)
> + return 2484;
> + else if (chan < 14)
> + return 2407 + chan * 5;
> + else
> + return 0; /* not supported */
> + }
> }
> EXPORT_SYMBOL(ieee80211_channel_to_frequency);
>
> int ieee80211_frequency_to_channel(int freq)
> {
> + /* see 802.11 17.3.8.3.2 and Annex J */
> if (freq == 2484)
> return 14;
> -
> - if (freq < 2484)
> + else if (freq < 2484)
> return (freq - 2407) / 5;
> -
> - /* FIXME: 802.11j 17.3.8.3.2 */
> - return freq/5 - 1000;
> + else if (freq >= 4910 && freq <= 4980)
> + return (freq - 4000) / 5;
> + else
> + return (freq - 5000) / 5;
> }
> EXPORT_SYMBOL(ieee80211_frequency_to_channel);
>
> diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c
> index 3e5dbd4..7f1f4ec 100644
> --- a/net/wireless/wext-compat.c
> +++ b/net/wireless/wext-compat.c
> @@ -267,9 +267,12 @@ int cfg80211_wext_freq(struct wiphy *wiphy, struct iw_freq *freq)
> * -EINVAL for impossible things.
> */
> if (freq->e == 0) {
> + enum ieee80211_band band = IEEE80211_BAND_2GHZ;
> if (freq->m < 0)
> return 0;
> - return ieee80211_channel_to_frequency(freq->m);
> + if (freq->m > 14)
> + band = IEEE80211_BAND_5GHZ;
> + return ieee80211_channel_to_frequency(freq->m, band);
> } else {
> int i, div = 1000000;
> for (i = 0; i < freq->e; i++)
>
>
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