From e6b7cde4d3e155f118b81f1f62f86554c529083a Mon Sep 17 00:00:00 2001 From: Simon Wunderlich Date: Wed, 28 Aug 2013 13:41:29 +0200 Subject: mac80211: split off channel switch parsing function The channel switch parsing function can be re-used for the IBSS code, put the common part into an extra function. Signed-off-by: Simon Wunderlich Signed-off-by: Mathias Kretschmer [also move/rename chandef_downgrade] Signed-off-by: Johannes Berg --- net/mac80211/spectmgmt.c | 162 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 162 insertions(+) (limited to 'net/mac80211/spectmgmt.c') diff --git a/net/mac80211/spectmgmt.c b/net/mac80211/spectmgmt.c index 578eea3fc04d..921597e279a3 100644 --- a/net/mac80211/spectmgmt.c +++ b/net/mac80211/spectmgmt.c @@ -21,6 +21,168 @@ #include "sta_info.h" #include "wme.h" +int ieee80211_parse_ch_switch_ie(struct ieee80211_sub_if_data *sdata, + struct ieee802_11_elems *elems, bool beacon, + enum ieee80211_band current_band, + u32 sta_flags, u8 *bssid, u8 *count, u8 *mode, + struct cfg80211_chan_def *new_chandef) +{ + enum ieee80211_band new_band; + int new_freq; + u8 new_chan_no; + struct ieee80211_channel *new_chan; + struct cfg80211_chan_def new_vht_chandef = {}; + const struct ieee80211_sec_chan_offs_ie *sec_chan_offs; + const struct ieee80211_wide_bw_chansw_ie *wide_bw_chansw_ie; + const struct ieee80211_ht_operation *ht_oper; + int secondary_channel_offset = -1; + + sec_chan_offs = elems->sec_chan_offs; + wide_bw_chansw_ie = elems->wide_bw_chansw_ie; + ht_oper = elems->ht_operation; + + if (sta_flags & (IEEE80211_STA_DISABLE_HT | + IEEE80211_STA_DISABLE_40MHZ)) { + sec_chan_offs = NULL; + wide_bw_chansw_ie = NULL; + /* only used for bandwidth here */ + ht_oper = NULL; + } + + if (sta_flags & IEEE80211_STA_DISABLE_VHT) + wide_bw_chansw_ie = NULL; + + if (elems->ext_chansw_ie) { + if (!ieee80211_operating_class_to_band( + elems->ext_chansw_ie->new_operating_class, + &new_band)) { + sdata_info(sdata, + "cannot understand ECSA IE operating class %d, disconnecting\n", + elems->ext_chansw_ie->new_operating_class); + return -EINVAL; + } + new_chan_no = elems->ext_chansw_ie->new_ch_num; + *count = elems->ext_chansw_ie->count; + *mode = elems->ext_chansw_ie->mode; + } else if (elems->ch_switch_ie) { + new_band = current_band; + new_chan_no = elems->ch_switch_ie->new_ch_num; + *count = elems->ch_switch_ie->count; + *mode = elems->ch_switch_ie->mode; + } else { + /* nothing here we understand */ + return 1; + } + + new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band); + new_chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq); + if (!new_chan || new_chan->flags & IEEE80211_CHAN_DISABLED) { + sdata_info(sdata, + "BSS %pM switches to unsupported channel (%d MHz), disconnecting\n", + bssid, new_freq); + return -EINVAL; + } + + if (!beacon && sec_chan_offs) { + secondary_channel_offset = sec_chan_offs->sec_chan_offs; + } else if (beacon && ht_oper) { + secondary_channel_offset = + ht_oper->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET; + } else if (!(sta_flags & IEEE80211_STA_DISABLE_HT)) { + /* If it's not a beacon, HT is enabled and the IE not present, + * it's 20 MHz, 802.11-2012 8.5.2.6: + * This element [the Secondary Channel Offset Element] is + * present when switching to a 40 MHz channel. It may be + * present when switching to a 20 MHz channel (in which + * case the secondary channel offset is set to SCN). + */ + secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE; + } + + switch (secondary_channel_offset) { + default: + /* secondary_channel_offset was present but is invalid */ + case IEEE80211_HT_PARAM_CHA_SEC_NONE: + cfg80211_chandef_create(new_chandef, new_chan, + NL80211_CHAN_HT20); + break; + case IEEE80211_HT_PARAM_CHA_SEC_ABOVE: + cfg80211_chandef_create(new_chandef, new_chan, + NL80211_CHAN_HT40PLUS); + break; + case IEEE80211_HT_PARAM_CHA_SEC_BELOW: + cfg80211_chandef_create(new_chandef, new_chan, + NL80211_CHAN_HT40MINUS); + break; + case -1: + cfg80211_chandef_create(new_chandef, new_chan, + NL80211_CHAN_NO_HT); + /* keep width for 5/10 MHz channels */ + switch (sdata->vif.bss_conf.chandef.width) { + case NL80211_CHAN_WIDTH_5: + case NL80211_CHAN_WIDTH_10: + new_chandef->width = sdata->vif.bss_conf.chandef.width; + break; + default: + break; + } + break; + } + + if (wide_bw_chansw_ie) { + new_vht_chandef.chan = new_chan; + new_vht_chandef.center_freq1 = + ieee80211_channel_to_frequency( + wide_bw_chansw_ie->new_center_freq_seg0, + new_band); + + switch (wide_bw_chansw_ie->new_channel_width) { + default: + /* hmmm, ignore VHT and use HT if present */ + case IEEE80211_VHT_CHANWIDTH_USE_HT: + new_vht_chandef.chan = NULL; + break; + case IEEE80211_VHT_CHANWIDTH_80MHZ: + new_vht_chandef.width = NL80211_CHAN_WIDTH_80; + break; + case IEEE80211_VHT_CHANWIDTH_160MHZ: + new_vht_chandef.width = NL80211_CHAN_WIDTH_160; + break; + case IEEE80211_VHT_CHANWIDTH_80P80MHZ: + /* field is otherwise reserved */ + new_vht_chandef.center_freq2 = + ieee80211_channel_to_frequency( + wide_bw_chansw_ie->new_center_freq_seg1, + new_band); + new_vht_chandef.width = NL80211_CHAN_WIDTH_80P80; + break; + } + if (sta_flags & IEEE80211_STA_DISABLE_80P80MHZ && + new_vht_chandef.width == NL80211_CHAN_WIDTH_80P80) + ieee80211_chandef_downgrade(&new_vht_chandef); + if (sta_flags & IEEE80211_STA_DISABLE_160MHZ && + new_vht_chandef.width == NL80211_CHAN_WIDTH_160) + ieee80211_chandef_downgrade(&new_vht_chandef); + if (sta_flags & IEEE80211_STA_DISABLE_40MHZ && + new_vht_chandef.width > NL80211_CHAN_WIDTH_20) + ieee80211_chandef_downgrade(&new_vht_chandef); + } + + /* if VHT data is there validate & use it */ + if (new_vht_chandef.chan) { + if (!cfg80211_chandef_compatible(&new_vht_chandef, + new_chandef)) { + sdata_info(sdata, + "BSS %pM: CSA has inconsistent channel data, disconnecting\n", + bssid); + return -EINVAL; + } + *new_chandef = new_vht_chandef; + } + + return 0; +} + static void ieee80211_send_refuse_measurement_request(struct ieee80211_sub_if_data *sdata, struct ieee80211_msrment_ie *request_ie, const u8 *da, const u8 *bssid, -- cgit v1.2.3