1 files changed, 153 insertions, 0 deletions

diff --git a/net/wireless/reg.c b/net/wireless/reg.c
new file mode 100644
index 000000000000..2b63c96dcf19
--- /dev/null
+++ b/net/wireless/reg.c
@@ -0,0 +1,153 @@
+/*
+ * Copyright 2002-2005, Instant802 Networks, Inc.
+ * Copyright 2005-2006, Devicescape Software, Inc.
+ * Copyright 2007       Johannes Berg <johannes@sipsolutions.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * This regulatory domain control implementation is highly incomplete, it
+ * only exists for the purpose of not regressing mac80211.
+ *
+ * For now, drivers can restrict the set of allowed channels by either
+ * not registering those channels or setting the IEEE80211_CHAN_DISABLED
+ * flag; that flag will only be *set* by this code, never *cleared.
+ *
+ * The usual implementation is for a driver to read a device EEPROM to
+ * determine which regulatory domain it should be operating under, then
+ * looking up the allowable channels in a driver-local table and finally
+ * registering those channels in the wiphy structure.
+ *
+ * Alternatively, drivers that trust the regulatory domain control here
+ * will register a complete set of capabilities and the control code
+ * will restrict the set by setting the IEEE80211_CHAN_* flags.
+ */
+#include <linux/kernel.h>
+#include <net/wireless.h>
+#include "core.h"
+
+static char *ieee80211_regdom = "US";
+module_param(ieee80211_regdom, charp, 0444);
+MODULE_PARM_DESC(ieee80211_regdom, "IEEE 802.11 regulatory domain code");
+
+struct ieee80211_channel_range {
+        short start_freq;
+        short end_freq;
+        int max_power;
+        int max_antenna_gain;
+        u32 flags;
+};
+
+struct ieee80211_regdomain {
+        const char *code;
+        const struct ieee80211_channel_range *ranges;
+        int n_ranges;
+};
+
+#define RANGE_PWR(_start, _end, _pwr, _ag, _flags)      \
+        { _start, _end, _pwr, _ag, _flags }
+
+
+/*
+ * Ideally, in the future, these definitions will be loaded from a
+ * userspace table via some daemon.
+ */
+static const struct ieee80211_channel_range ieee80211_US_channels[] = {
+        /* IEEE 802.11b/g, channels 1..11 */
+        RANGE_PWR(2412, 2462, 27, 6, 0),
+        /* IEEE 802.11a, channels 52..64 */
+        RANGE_PWR(5260, 5320, 23, 6, 0),
+        /* IEEE 802.11a, channels 149..165, outdoor */
+        RANGE_PWR(5745, 5825, 30, 6, 0),
+};
+
+static const struct ieee80211_channel_range ieee80211_JP_channels[] = {
+        /* IEEE 802.11b/g, channels 1..14 */
+        RANGE_PWR(2412, 2484, 20, 6, 0),
+        /* IEEE 802.11a, channels 34..48 */
+        RANGE_PWR(5170, 5240, 20, 6, IEEE80211_CHAN_PASSIVE_SCAN),
+        /* IEEE 802.11a, channels 52..64 */
+        RANGE_PWR(5260, 5320, 20, 6, IEEE80211_CHAN_NO_IBSS |
+                                     IEEE80211_CHAN_RADAR),
+};
+
+#define REGDOM(_code)                                                   \
+        {                                                               \
+                .code = __stringify(_code),                             \
+                .ranges = ieee80211_ ##_code## _channels,               \
+                .n_ranges = ARRAY_SIZE(ieee80211_ ##_code## _channels), \
+        }
+
+static const struct ieee80211_regdomain ieee80211_regdoms[] = {
+        REGDOM(US),
+        REGDOM(JP),
+};
+
+
+static const struct ieee80211_regdomain *get_regdom(void)
+{
+        static const struct ieee80211_channel_range
+        ieee80211_world_channels[] = {
+                /* IEEE 802.11b/g, channels 1..11 */
+                RANGE_PWR(2412, 2462, 27, 6, 0),
+        };
+        static const struct ieee80211_regdomain regdom_world = REGDOM(world);
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(ieee80211_regdoms); i++)
+                if (strcmp(ieee80211_regdom, ieee80211_regdoms[i].code) == 0)
+                        return &ieee80211_regdoms[i];
+
+        return &regdom_world;
+}
+
+
+static void handle_channel(struct ieee80211_channel *chan,
+                           const struct ieee80211_regdomain *rd)
+{
+        int i;
+        u32 flags = chan->orig_flags;
+        const struct ieee80211_channel_range *rg = NULL;
+
+        for (i = 0; i < rd->n_ranges; i++) {
+                if (rd->ranges[i].start_freq <= chan->center_freq &&
+                    chan->center_freq <= rd->ranges[i].end_freq) {
+                        rg = &rd->ranges[i];
+                        break;
+                }
+        }
+
+        if (!rg) {
+                /* not found */
+                flags |= IEEE80211_CHAN_DISABLED;
+                chan->flags = flags;
+                return;
+        }
+
+        chan->flags = flags;
+        chan->max_antenna_gain = min(chan->orig_mag,
+                                         rg->max_antenna_gain);
+        chan->max_power = min(chan->orig_mpwr, rg->max_power);
+}
+
+static void handle_band(struct ieee80211_supported_band *sband,
+                        const struct ieee80211_regdomain *rd)
+{
+        int i;
+
+        for (i = 0; i < sband->n_channels; i++)
+                handle_channel(&sband->channels[i], rd);
+}
+
+void wiphy_update_regulatory(struct wiphy *wiphy)
+{
+        enum ieee80211_band band;
+        const struct ieee80211_regdomain *rd = get_regdom();
+
+        for (band = 0; band < IEEE80211_NUM_BANDS; band++)
+                if (wiphy->bands[band])
+                        handle_band(wiphy->bands[band], rd);
+}