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-rw-r--r--net/wireless/chan.c510
1 files changed, 510 insertions, 0 deletions
diff --git a/net/wireless/chan.c b/net/wireless/chan.c
new file mode 100644
index 0000000..fd556ac
--- /dev/null
+++ b/net/wireless/chan.c
@@ -0,0 +1,510 @@
+/*
+ * This file contains helper code to handle channel
+ * settings and keeping track of what is possible at
+ * any point in time.
+ *
+ * Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
+ */
+
+#include <linux/export.h>
+#include <net/cfg80211.h>
+#include "core.h"
+#include "rdev-ops.h"
+
+void cfg80211_chandef_create(struct cfg80211_chan_def *chandef,
+ struct ieee80211_channel *chan,
+ enum nl80211_channel_type chan_type)
+{
+ if (WARN_ON(!chan))
+ return;
+
+ chandef->chan = chan;
+ chandef->center_freq2 = 0;
+
+ switch (chan_type) {
+ case NL80211_CHAN_NO_HT:
+ chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
+ chandef->center_freq1 = chan->center_freq;
+ break;
+ case NL80211_CHAN_HT20:
+ chandef->width = NL80211_CHAN_WIDTH_20;
+ chandef->center_freq1 = chan->center_freq;
+ break;
+ case NL80211_CHAN_HT40PLUS:
+ chandef->width = NL80211_CHAN_WIDTH_40;
+ chandef->center_freq1 = chan->center_freq + 10;
+ break;
+ case NL80211_CHAN_HT40MINUS:
+ chandef->width = NL80211_CHAN_WIDTH_40;
+ chandef->center_freq1 = chan->center_freq - 10;
+ break;
+ default:
+ WARN_ON(1);
+ }
+}
+EXPORT_SYMBOL(cfg80211_chandef_create);
+
+bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)
+{
+ u32 control_freq;
+
+ if (!chandef->chan)
+ return false;
+
+ control_freq = chandef->chan->center_freq;
+
+ switch (chandef->width) {
+ case NL80211_CHAN_WIDTH_20:
+ case NL80211_CHAN_WIDTH_20_NOHT:
+ if (chandef->center_freq1 != control_freq)
+ return false;
+ if (chandef->center_freq2)
+ return false;
+ break;
+ case NL80211_CHAN_WIDTH_40:
+ if (chandef->center_freq1 != control_freq + 10 &&
+ chandef->center_freq1 != control_freq - 10)
+ return false;
+ if (chandef->center_freq2)
+ return false;
+ break;
+ case NL80211_CHAN_WIDTH_80P80:
+ if (chandef->center_freq1 != control_freq + 30 &&
+ chandef->center_freq1 != control_freq + 10 &&
+ chandef->center_freq1 != control_freq - 10 &&
+ chandef->center_freq1 != control_freq - 30)
+ return false;
+ if (!chandef->center_freq2)
+ return false;
+ /* adjacent is not allowed -- that's a 160 MHz channel */
+ if (chandef->center_freq1 - chandef->center_freq2 == 80 ||
+ chandef->center_freq2 - chandef->center_freq1 == 80)
+ return false;
+ break;
+ case NL80211_CHAN_WIDTH_80:
+ if (chandef->center_freq1 != control_freq + 30 &&
+ chandef->center_freq1 != control_freq + 10 &&
+ chandef->center_freq1 != control_freq - 10 &&
+ chandef->center_freq1 != control_freq - 30)
+ return false;
+ if (chandef->center_freq2)
+ return false;
+ break;
+ case NL80211_CHAN_WIDTH_160:
+ if (chandef->center_freq1 != control_freq + 70 &&
+ chandef->center_freq1 != control_freq + 50 &&
+ chandef->center_freq1 != control_freq + 30 &&
+ chandef->center_freq1 != control_freq + 10 &&
+ chandef->center_freq1 != control_freq - 10 &&
+ chandef->center_freq1 != control_freq - 30 &&
+ chandef->center_freq1 != control_freq - 50 &&
+ chandef->center_freq1 != control_freq - 70)
+ return false;
+ if (chandef->center_freq2)
+ return false;
+ break;
+ default:
+ return false;
+ }
+
+ return true;
+}
+EXPORT_SYMBOL(cfg80211_chandef_valid);
+
+static void chandef_primary_freqs(const struct cfg80211_chan_def *c,
+ int *pri40, int *pri80)
+{
+ int tmp;
+
+ switch (c->width) {
+ case NL80211_CHAN_WIDTH_40:
+ *pri40 = c->center_freq1;
+ *pri80 = 0;
+ break;
+ case NL80211_CHAN_WIDTH_80:
+ case NL80211_CHAN_WIDTH_80P80:
+ *pri80 = c->center_freq1;
+ /* n_P20 */
+ tmp = (30 + c->chan->center_freq - c->center_freq1)/20;
+ /* n_P40 */
+ tmp /= 2;
+ /* freq_P40 */
+ *pri40 = c->center_freq1 - 20 + 40 * tmp;
+ break;
+ case NL80211_CHAN_WIDTH_160:
+ /* n_P20 */
+ tmp = (70 + c->chan->center_freq - c->center_freq1)/20;
+ /* n_P40 */
+ tmp /= 2;
+ /* freq_P40 */
+ *pri40 = c->center_freq1 - 60 + 40 * tmp;
+ /* n_P80 */
+ tmp /= 2;
+ *pri80 = c->center_freq1 - 40 + 80 * tmp;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ }
+}
+
+static int cfg80211_chandef_get_width(const struct cfg80211_chan_def *c)
+{
+ int width;
+
+ switch (c->width) {
+ case NL80211_CHAN_WIDTH_20:
+ case NL80211_CHAN_WIDTH_20_NOHT:
+ width = 20;
+ break;
+ case NL80211_CHAN_WIDTH_40:
+ width = 40;
+ break;
+ case NL80211_CHAN_WIDTH_80P80:
+ case NL80211_CHAN_WIDTH_80:
+ width = 80;
+ break;
+ case NL80211_CHAN_WIDTH_160:
+ width = 160;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return -1;
+ }
+ return width;
+}
+
+const struct cfg80211_chan_def *
+cfg80211_chandef_compatible(const struct cfg80211_chan_def *c1,
+ const struct cfg80211_chan_def *c2)
+{
+ u32 c1_pri40, c1_pri80, c2_pri40, c2_pri80;
+
+ /* If they are identical, return */
+ if (cfg80211_chandef_identical(c1, c2))
+ return c1;
+
+ /* otherwise, must have same control channel */
+ if (c1->chan != c2->chan)
+ return NULL;
+
+ /*
+ * If they have the same width, but aren't identical,
+ * then they can't be compatible.
+ */
+ if (c1->width == c2->width)
+ return NULL;
+
+ if (c1->width == NL80211_CHAN_WIDTH_20_NOHT ||
+ c1->width == NL80211_CHAN_WIDTH_20)
+ return c2;
+
+ if (c2->width == NL80211_CHAN_WIDTH_20_NOHT ||
+ c2->width == NL80211_CHAN_WIDTH_20)
+ return c1;
+
+ chandef_primary_freqs(c1, &c1_pri40, &c1_pri80);
+ chandef_primary_freqs(c2, &c2_pri40, &c2_pri80);
+
+ if (c1_pri40 != c2_pri40)
+ return NULL;
+
+ WARN_ON(!c1_pri80 && !c2_pri80);
+ if (c1_pri80 && c2_pri80 && c1_pri80 != c2_pri80)
+ return NULL;
+
+ if (c1->width > c2->width)
+ return c1;
+ return c2;
+}
+EXPORT_SYMBOL(cfg80211_chandef_compatible);
+
+static void cfg80211_set_chans_dfs_state(struct wiphy *wiphy, u32 center_freq,
+ u32 bandwidth,
+ enum nl80211_dfs_state dfs_state)
+{
+ struct ieee80211_channel *c;
+ u32 freq;
+
+ for (freq = center_freq - bandwidth/2 + 10;
+ freq <= center_freq + bandwidth/2 - 10;
+ freq += 20) {
+ c = ieee80211_get_channel(wiphy, freq);
+ if (!c || !(c->flags & IEEE80211_CHAN_RADAR))
+ continue;
+
+ c->dfs_state = dfs_state;
+ c->dfs_state_entered = jiffies;
+ }
+}
+
+void cfg80211_set_dfs_state(struct wiphy *wiphy,
+ const struct cfg80211_chan_def *chandef,
+ enum nl80211_dfs_state dfs_state)
+{
+ int width;
+
+ if (WARN_ON(!cfg80211_chandef_valid(chandef)))
+ return;
+
+ width = cfg80211_chandef_get_width(chandef);
+ if (width < 0)
+ return;
+
+ cfg80211_set_chans_dfs_state(wiphy, chandef->center_freq1,
+ width, dfs_state);
+
+ if (!chandef->center_freq2)
+ return;
+ cfg80211_set_chans_dfs_state(wiphy, chandef->center_freq2,
+ width, dfs_state);
+}
+
+static int cfg80211_get_chans_dfs_required(struct wiphy *wiphy,
+ u32 center_freq,
+ u32 bandwidth)
+{
+ struct ieee80211_channel *c;
+ u32 freq;
+
+ for (freq = center_freq - bandwidth/2 + 10;
+ freq <= center_freq + bandwidth/2 - 10;
+ freq += 20) {
+ c = ieee80211_get_channel(wiphy, freq);
+ if (!c)
+ return -EINVAL;
+
+ if (c->flags & IEEE80211_CHAN_RADAR)
+ return 1;
+ }
+ return 0;
+}
+
+
+int cfg80211_chandef_dfs_required(struct wiphy *wiphy,
+ const struct cfg80211_chan_def *chandef)
+{
+ int width;
+ int r;
+
+ if (WARN_ON(!cfg80211_chandef_valid(chandef)))
+ return -EINVAL;
+
+ width = cfg80211_chandef_get_width(chandef);
+ if (width < 0)
+ return -EINVAL;
+
+ r = cfg80211_get_chans_dfs_required(wiphy, chandef->center_freq1,
+ width);
+ if (r)
+ return r;
+
+ if (!chandef->center_freq2)
+ return 0;
+
+ return cfg80211_get_chans_dfs_required(wiphy, chandef->center_freq2,
+ width);
+}
+
+static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
+ u32 center_freq, u32 bandwidth,
+ u32 prohibited_flags)
+{
+ struct ieee80211_channel *c;
+ u32 freq;
+
+ for (freq = center_freq - bandwidth/2 + 10;
+ freq <= center_freq + bandwidth/2 - 10;
+ freq += 20) {
+ c = ieee80211_get_channel(wiphy, freq);
+ if (!c)
+ return false;
+
+ /* check for radar flags */
+ if ((prohibited_flags & c->flags & IEEE80211_CHAN_RADAR) &&
+ (c->dfs_state != NL80211_DFS_AVAILABLE))
+ return false;
+
+ /* check for the other flags */
+ if (c->flags & prohibited_flags & ~IEEE80211_CHAN_RADAR)
+ return false;
+ }
+
+ return true;
+}
+
+bool cfg80211_chandef_usable(struct wiphy *wiphy,
+ const struct cfg80211_chan_def *chandef,
+ u32 prohibited_flags)
+{
+ struct ieee80211_sta_ht_cap *ht_cap;
+ struct ieee80211_sta_vht_cap *vht_cap;
+ u32 width, control_freq;
+
+ if (WARN_ON(!cfg80211_chandef_valid(chandef)))
+ return false;
+
+ ht_cap = &wiphy->bands[chandef->chan->band]->ht_cap;
+ vht_cap = &wiphy->bands[chandef->chan->band]->vht_cap;
+
+ control_freq = chandef->chan->center_freq;
+
+ switch (chandef->width) {
+ case NL80211_CHAN_WIDTH_20:
+ if (!ht_cap->ht_supported)
+ return false;
+ case NL80211_CHAN_WIDTH_20_NOHT:
+ width = 20;
+ break;
+ case NL80211_CHAN_WIDTH_40:
+ width = 40;
+ if (!ht_cap->ht_supported)
+ return false;
+ if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
+ ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
+ return false;
+ if (chandef->center_freq1 < control_freq &&
+ chandef->chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
+ return false;
+ if (chandef->center_freq1 > control_freq &&
+ chandef->chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
+ return false;
+ break;
+ case NL80211_CHAN_WIDTH_80P80:
+ if (!(vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ))
+ return false;
+ case NL80211_CHAN_WIDTH_80:
+ if (!vht_cap->vht_supported)
+ return false;
+ prohibited_flags |= IEEE80211_CHAN_NO_80MHZ;
+ width = 80;
+ break;
+ case NL80211_CHAN_WIDTH_160:
+ if (!vht_cap->vht_supported)
+ return false;
+ if (!(vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ))
+ return false;
+ prohibited_flags |= IEEE80211_CHAN_NO_160MHZ;
+ width = 160;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return false;
+ }
+
+ /*
+ * TODO: What if there are only certain 80/160/80+80 MHz channels
+ * allowed by the driver, or only certain combinations?
+ * For 40 MHz the driver can set the NO_HT40 flags, but for
+ * 80/160 MHz and in particular 80+80 MHz this isn't really
+ * feasible and we only have NO_80MHZ/NO_160MHZ so far but
+ * no way to cover 80+80 MHz or more complex restrictions.
+ * Note that such restrictions also need to be advertised to
+ * userspace, for example for P2P channel selection.
+ */
+
+ if (width > 20)
+ prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
+
+ if (!cfg80211_secondary_chans_ok(wiphy, chandef->center_freq1,
+ width, prohibited_flags))
+ return false;
+
+ if (!chandef->center_freq2)
+ return true;
+ return cfg80211_secondary_chans_ok(wiphy, chandef->center_freq2,
+ width, prohibited_flags);
+}
+EXPORT_SYMBOL(cfg80211_chandef_usable);
+
+bool cfg80211_reg_can_beacon(struct wiphy *wiphy,
+ struct cfg80211_chan_def *chandef)
+{
+ bool res;
+
+ trace_cfg80211_reg_can_beacon(wiphy, chandef);
+
+ res = cfg80211_chandef_usable(wiphy, chandef,
+ IEEE80211_CHAN_DISABLED |
+ IEEE80211_CHAN_PASSIVE_SCAN |
+ IEEE80211_CHAN_NO_IBSS |
+ IEEE80211_CHAN_RADAR);
+
+ trace_cfg80211_return_bool(res);
+ return res;
+}
+EXPORT_SYMBOL(cfg80211_reg_can_beacon);
+
+int cfg80211_set_monitor_channel(struct cfg80211_registered_device *rdev,
+ struct cfg80211_chan_def *chandef)
+{
+ if (!rdev->ops->set_monitor_channel)
+ return -EOPNOTSUPP;
+ if (!cfg80211_has_monitors_only(rdev))
+ return -EBUSY;
+
+ return rdev_set_monitor_channel(rdev, chandef);
+}
+
+void
+cfg80211_get_chan_state(struct wireless_dev *wdev,
+ struct ieee80211_channel **chan,
+ enum cfg80211_chan_mode *chanmode)
+{
+ *chan = NULL;
+ *chanmode = CHAN_MODE_UNDEFINED;
+
+ ASSERT_WDEV_LOCK(wdev);
+
+ if (wdev->netdev && !netif_running(wdev->netdev))
+ return;
+
+ switch (wdev->iftype) {
+ case NL80211_IFTYPE_ADHOC:
+ if (wdev->current_bss) {
+ *chan = wdev->current_bss->pub.channel;
+ *chanmode = wdev->ibss_fixed
+ ? CHAN_MODE_SHARED
+ : CHAN_MODE_EXCLUSIVE;
+ return;
+ }
+ case NL80211_IFTYPE_STATION:
+ case NL80211_IFTYPE_P2P_CLIENT:
+ if (wdev->current_bss) {
+ *chan = wdev->current_bss->pub.channel;
+ *chanmode = CHAN_MODE_SHARED;
+ return;
+ }
+ break;
+ case NL80211_IFTYPE_AP:
+ case NL80211_IFTYPE_P2P_GO:
+ if (wdev->cac_started) {
+ *chan = wdev->channel;
+ *chanmode = CHAN_MODE_SHARED;
+ } else if (wdev->beacon_interval) {
+ *chan = wdev->channel;
+ *chanmode = CHAN_MODE_SHARED;
+ }
+ return;
+ case NL80211_IFTYPE_MESH_POINT:
+ if (wdev->mesh_id_len) {
+ *chan = wdev->channel;
+ *chanmode = CHAN_MODE_SHARED;
+ }
+ return;
+ case NL80211_IFTYPE_MONITOR:
+ case NL80211_IFTYPE_AP_VLAN:
+ case NL80211_IFTYPE_WDS:
+ /* these interface types don't really have a channel */
+ return;
+ case NL80211_IFTYPE_P2P_DEVICE:
+ if (wdev->wiphy->features &
+ NL80211_FEATURE_P2P_DEVICE_NEEDS_CHANNEL)
+ *chanmode = CHAN_MODE_EXCLUSIVE;
+ return;
+ case NL80211_IFTYPE_UNSPECIFIED:
+ case NUM_NL80211_IFTYPES:
+ WARN_ON(1);
+ }
+
+ return;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-18 08:28:02 +0000