[PATCH] mac80211: regulatory domain cleanup

Currently, a function misnamed ieee80211_init_client() is used to handle
regulatory domain control. It is called from
ieee80211_register_hwmode(), which typically runs 2 or 3 times
(802.11a/b/g), but each time it iterates over all the modes.

This patch cleans this up and removes the confusion:
ieee80211_init_client was effectively renamed to
ieee80211_set_default_regdomain and is now run on a per-mode basis
(doesn't have to deal with netdevs). I also moved the regdomain handling
code into its own file and added some documentation.

Signed-off-by: Daniel Drake <dsd@gentoo.org>
Acked-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 157 insertions, 0 deletions

diff --git a/net/mac80211/regdomain.c b/net/mac80211/regdomain.c
new file mode 100644
index 000000000000..32e5dca6b6b9
--- /dev/null
+++ b/net/mac80211/regdomain.c
@@ -0,0 +1,157 @@
+/*
+ * Copyright 2002-2005, Instant802 Networks, Inc.
+ * Copyright 2005-2006, Devicescape Software, Inc.
+ *
+ * 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 known to be incomplete
+ * and confusing. mac80211 regulatory domain control will be significantly
+ * reworked in the not-too-distant future.
+ *
+ * For now, drivers wishing to control which channels are and aren't available
+ * are advised as follows:
+ *  - set the IEEE80211_HW_DEFAULT_REG_DOMAIN_CONFIGURED flag
+ *  - continue to include *ALL* possible channels in the modes registered
+ *    through ieee80211_register_hwmode()
+ *  - for each allowable ieee80211_channel structure registered in the above
+ *    call, set the flag member to some meaningful value such as
+ *    IEEE80211_CHAN_W_SCAN | IEEE80211_CHAN_W_ACTIVE_SCAN |
+ *    IEEE80211_CHAN_W_IBSS.
+ *  - leave flag as 0 for non-allowable channels
+ *
+ * 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, then performing
+ * the above.
+ */
+
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <net/mac80211.h>
+
+static int ieee80211_regdom = 0x10; /* FCC */
+module_param(ieee80211_regdom, int, 0444);
+MODULE_PARM_DESC(ieee80211_regdom, "IEEE 802.11 regulatory domain; 64=MKK");
+
+/*
+ * If firmware is upgraded by the vendor, additional channels can be used based
+ * on the new Japanese regulatory rules. This is indicated by setting
+ * ieee80211_japan_5ghz module parameter to one when loading the 80211 kernel
+ * module.
+ */
+static int ieee80211_japan_5ghz /* = 0 */;
+module_param(ieee80211_japan_5ghz, int, 0444);
+MODULE_PARM_DESC(ieee80211_japan_5ghz, "Vendor-updated firmware for 5 GHz");
+
+
+struct ieee80211_channel_range {
+        short start_freq;
+        short end_freq;
+        unsigned char power_level;
+        unsigned char antenna_max;
+};
+
+static const struct ieee80211_channel_range ieee80211_fcc_channels[] = {
+        { 2412, 2462, 27, 6 } /* IEEE 802.11b/g, channels 1..11 */,
+        { 5180, 5240, 17, 6 } /* IEEE 802.11a, channels 36..48 */,
+        { 5260, 5320, 23, 6 } /* IEEE 802.11a, channels 52..64 */,
+        { 5745, 5825, 30, 6 } /* IEEE 802.11a, channels 149..165, outdoor */,
+        { 0 }
+};
+
+static const struct ieee80211_channel_range ieee80211_mkk_channels[] = {
+        { 2412, 2472, 20, 6 } /* IEEE 802.11b/g, channels 1..13 */,
+        { 5170, 5240, 20, 6 } /* IEEE 802.11a, channels 34..48 */,
+        { 5260, 5320, 20, 6 } /* IEEE 802.11a, channels 52..64 */,
+        { 0 }
+};
+
+
+static const struct ieee80211_channel_range *channel_range =
+        ieee80211_fcc_channels;
+
+
+static void ieee80211_unmask_channel(int mode, struct ieee80211_channel *chan)
+{
+        int i;
+
+        chan->flag = 0;
+
+        if (ieee80211_regdom == 64 &&
+            (mode == MODE_ATHEROS_TURBO || mode == MODE_ATHEROS_TURBOG)) {
+                /* Do not allow Turbo modes in Japan. */
+                return;
+        }
+
+        for (i = 0; channel_range[i].start_freq; i++) {
+                const struct ieee80211_channel_range *r = &channel_range[i];
+                if (r->start_freq <= chan->freq && r->end_freq >= chan->freq) {
+                        if (ieee80211_regdom == 64 && !ieee80211_japan_5ghz &&
+                            chan->freq >= 5260 && chan->freq <= 5320) {
+                                /*
+                                 * Skip new channels in Japan since the
+                                 * firmware was not marked having been upgraded
+                                 * by the vendor.
+                                 */
+                                continue;
+                        }
+
+                        if (ieee80211_regdom == 0x10 &&
+                            (chan->freq == 5190 || chan->freq == 5210 ||
+                             chan->freq == 5230)) {
+                                    /* Skip MKK channels when in FCC domain. */
+                                    continue;
+                        }
+
+                        chan->flag |= IEEE80211_CHAN_W_SCAN |
+                                IEEE80211_CHAN_W_ACTIVE_SCAN |
+                                IEEE80211_CHAN_W_IBSS;
+                        chan->power_level = r->power_level;
+                        chan->antenna_max = r->antenna_max;
+
+                        if (ieee80211_regdom == 64 &&
+                            (chan->freq == 5170 || chan->freq == 5190 ||
+                             chan->freq == 5210 || chan->freq == 5230)) {
+                                /*
+                                 * New regulatory rules in Japan have backwards
+                                 * compatibility with old channels in 5.15-5.25
+                                 * GHz band, but the station is not allowed to
+                                 * use active scan on these old channels.
+                                 */
+                                chan->flag &= ~IEEE80211_CHAN_W_ACTIVE_SCAN;
+                        }
+
+                        if (ieee80211_regdom == 64 &&
+                            (chan->freq == 5260 || chan->freq == 5280 ||
+                             chan->freq == 5300 || chan->freq == 5320)) {
+                                /*
+                                 * IBSS is not allowed on 5.25-5.35 GHz band
+                                 * due to radar detection requirements.
+                                 */
+                                chan->flag &= ~IEEE80211_CHAN_W_IBSS;
+                        }
+
+                        break;
+                }
+        }
+}
+
+
+void ieee80211_set_default_regdomain(struct ieee80211_hw_mode *mode)
+{
+        int c;
+        for (c = 0; c < mode->num_channels; c++)
+                ieee80211_unmask_channel(mode->mode, &mode->channels[c]);
+}
+
+
+void ieee80211_regdomain_init(void)
+{
+        if (ieee80211_regdom == 0x40)
+                channel_range = ieee80211_mkk_channels;
+}
+