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linux/net/wireless/reg.c

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/*
* Copyright 2002-2005, Instant802 Networks, Inc.
* Copyright 2005-2006, Devicescape Software, Inc.
* Copyright 2007 Johannes Berg <johannes@sipsolutions.net>
* Copyright 2008 Luis R. Rodriguez <lrodriguz@atheros.com>
*
* 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.
*/
/**
* DOC: Wireless regulatory infrastructure
*
* 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.
*
* Another set of compliance enforcement is for drivers to use their
* own compliance limits which can be stored on the EEPROM. The host
* driver or firmware may ensure these are used.
*
* In addition to all this we provide an extra layer of regulatory
* conformance. For drivers which do not have any regulatory
* information CRDA provides the complete regulatory solution.
* For others it provides a community effort on further restrictions
* to enhance compliance.
*
* Note: When number of rules --> infinity we will not be able to
* index on alpha2 any more, instead we'll probably have to
* rely on some SHA1 checksum of the regdomain for example.
*
*/
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/random.h>
#include <linux/nl80211.h>
#include <linux/platform_device.h>
#include <net/wireless.h>
#include <net/cfg80211.h>
#include "core.h"
#include "reg.h"
/**
* struct regulatory_request - receipt of last regulatory request
*
* @wiphy: this is set if this request's initiator is
* %REGDOM_SET_BY_COUNTRY_IE or %REGDOM_SET_BY_DRIVER. This
* can be used by the wireless core to deal with conflicts
* and potentially inform users of which devices specifically
* cased the conflicts.
* @initiator: indicates who sent this request, could be any of
* of those set in reg_set_by, %REGDOM_SET_BY_*
* @alpha2: the ISO / IEC 3166 alpha2 country code of the requested
* regulatory domain. We have a few special codes:
* 00 - World regulatory domain
* 99 - built by driver but a specific alpha2 cannot be determined
* 98 - result of an intersection between two regulatory domains
* @intersect: indicates whether the wireless core should intersect
* the requested regulatory domain with the presently set regulatory
* domain.
* @country_ie_checksum: checksum of the last processed and accepted
* country IE
* @country_ie_env: lets us know if the AP is telling us we are outdoor,
* indoor, or if it doesn't matter
*/
struct regulatory_request {
struct wiphy *wiphy;
enum reg_set_by initiator;
char alpha2[2];
bool intersect;
u32 country_ie_checksum;
enum environment_cap country_ie_env;
};
/* Receipt of information from last regulatory request */
static struct regulatory_request *last_request;
/* To trigger userspace events */
static struct platform_device *reg_pdev;
/* Keep the ordering from large to small */
static u32 supported_bandwidths[] = {
MHZ_TO_KHZ(40),
MHZ_TO_KHZ(20),
};
/* Central wireless core regulatory domains, we only need two,
* the current one and a world regulatory domain in case we have no
* information to give us an alpha2 */
static const struct ieee80211_regdomain *cfg80211_regdomain;
/* We use this as a place for the rd structure built from the
* last parsed country IE to rest until CRDA gets back to us with
* what it thinks should apply for the same country */
static const struct ieee80211_regdomain *country_ie_regdomain;
/* We keep a static world regulatory domain in case of the absence of CRDA */
static const struct ieee80211_regdomain world_regdom = {
.n_reg_rules = 1,
.alpha2 = "00",
.reg_rules = {
REG_RULE(2412-10, 2462+10, 40, 6, 20,
NL80211_RRF_PASSIVE_SCAN |
NL80211_RRF_NO_IBSS),
}
};
static const struct ieee80211_regdomain *cfg80211_world_regdom =
&world_regdom;
#ifdef CONFIG_WIRELESS_OLD_REGULATORY
static char *ieee80211_regdom = "US";
module_param(ieee80211_regdom, charp, 0444);
MODULE_PARM_DESC(ieee80211_regdom, "IEEE 802.11 regulatory domain code");
/* We assume 40 MHz bandwidth for the old regulatory work.
* We make emphasis we are using the exact same frequencies
* as before */
static const struct ieee80211_regdomain us_regdom = {
.n_reg_rules = 6,
.alpha2 = "US",
.reg_rules = {
/* IEEE 802.11b/g, channels 1..11 */
REG_RULE(2412-10, 2462+10, 40, 6, 27, 0),
/* IEEE 802.11a, channel 36 */
REG_RULE(5180-10, 5180+10, 40, 6, 23, 0),
/* IEEE 802.11a, channel 40 */
REG_RULE(5200-10, 5200+10, 40, 6, 23, 0),
/* IEEE 802.11a, channel 44 */
REG_RULE(5220-10, 5220+10, 40, 6, 23, 0),
/* IEEE 802.11a, channels 48..64 */
REG_RULE(5240-10, 5320+10, 40, 6, 23, 0),
/* IEEE 802.11a, channels 149..165, outdoor */
REG_RULE(5745-10, 5825+10, 40, 6, 30, 0),
}
};
static const struct ieee80211_regdomain jp_regdom = {
.n_reg_rules = 3,
.alpha2 = "JP",
.reg_rules = {
/* IEEE 802.11b/g, channels 1..14 */
REG_RULE(2412-10, 2484+10, 40, 6, 20, 0),
/* IEEE 802.11a, channels 34..48 */
REG_RULE(5170-10, 5240+10, 40, 6, 20,
NL80211_RRF_PASSIVE_SCAN),
/* IEEE 802.11a, channels 52..64 */
REG_RULE(5260-10, 5320+10, 40, 6, 20,
NL80211_RRF_NO_IBSS |
NL80211_RRF_DFS),
}
};
static const struct ieee80211_regdomain eu_regdom = {
.n_reg_rules = 6,
/* This alpha2 is bogus, we leave it here just for stupid
* backward compatibility */
.alpha2 = "EU",
.reg_rules = {
/* IEEE 802.11b/g, channels 1..13 */
REG_RULE(2412-10, 2472+10, 40, 6, 20, 0),
/* IEEE 802.11a, channel 36 */
REG_RULE(5180-10, 5180+10, 40, 6, 23,
NL80211_RRF_PASSIVE_SCAN),
/* IEEE 802.11a, channel 40 */
REG_RULE(5200-10, 5200+10, 40, 6, 23,
NL80211_RRF_PASSIVE_SCAN),
/* IEEE 802.11a, channel 44 */
REG_RULE(5220-10, 5220+10, 40, 6, 23,
NL80211_RRF_PASSIVE_SCAN),
/* IEEE 802.11a, channels 48..64 */
REG_RULE(5240-10, 5320+10, 40, 6, 20,
NL80211_RRF_NO_IBSS |
NL80211_RRF_DFS),
/* IEEE 802.11a, channels 100..140 */
REG_RULE(5500-10, 5700+10, 40, 6, 30,
NL80211_RRF_NO_IBSS |
NL80211_RRF_DFS),
}
};
static const struct ieee80211_regdomain *static_regdom(char *alpha2)
{
if (alpha2[0] == 'U' && alpha2[1] == 'S')
return &us_regdom;
if (alpha2[0] == 'J' && alpha2[1] == 'P')
return &jp_regdom;
if (alpha2[0] == 'E' && alpha2[1] == 'U')
return &eu_regdom;
/* Default, as per the old rules */
return &us_regdom;
}
static bool is_old_static_regdom(const struct ieee80211_regdomain *rd)
{
if (rd == &us_regdom || rd == &jp_regdom || rd == &eu_regdom)
return true;
return false;
}
#else
static inline bool is_old_static_regdom(const struct ieee80211_regdomain *rd)
{
return false;
}
#endif
static void reset_regdomains(void)
{
/* avoid freeing static information or freeing something twice */
if (cfg80211_regdomain == cfg80211_world_regdom)
cfg80211_regdomain = NULL;
if (cfg80211_world_regdom == &world_regdom)
cfg80211_world_regdom = NULL;
if (cfg80211_regdomain == &world_regdom)
cfg80211_regdomain = NULL;
if (is_old_static_regdom(cfg80211_regdomain))
cfg80211_regdomain = NULL;
kfree(cfg80211_regdomain);
kfree(cfg80211_world_regdom);
cfg80211_world_regdom = &world_regdom;
cfg80211_regdomain = NULL;
}
/* Dynamic world regulatory domain requested by the wireless
* core upon initialization */
static void update_world_regdomain(const struct ieee80211_regdomain *rd)
{
BUG_ON(!last_request);
reset_regdomains();
cfg80211_world_regdom = rd;
cfg80211_regdomain = rd;
}
bool is_world_regdom(const char *alpha2)
{
if (!alpha2)
return false;
if (alpha2[0] == '0' && alpha2[1] == '0')
return true;
return false;
}
static bool is_alpha2_set(const char *alpha2)
{
if (!alpha2)
return false;
if (alpha2[0] != 0 && alpha2[1] != 0)
return true;
return false;
}
static bool is_alpha_upper(char letter)
{
/* ASCII A - Z */
if (letter >= 65 && letter <= 90)
return true;
return false;
}
static bool is_unknown_alpha2(const char *alpha2)
{
if (!alpha2)
return false;
/* Special case where regulatory domain was built by driver
* but a specific alpha2 cannot be determined */
if (alpha2[0] == '9' && alpha2[1] == '9')
return true;
return false;
}
static bool is_intersected_alpha2(const char *alpha2)
{
if (!alpha2)
return false;
/* Special case where regulatory domain is the
* result of an intersection between two regulatory domain
* structures */
if (alpha2[0] == '9' && alpha2[1] == '8')
return true;
return false;
}
static bool is_an_alpha2(const char *alpha2)
{
if (!alpha2)
return false;
if (is_alpha_upper(alpha2[0]) && is_alpha_upper(alpha2[1]))
return true;
return false;
}
static bool alpha2_equal(const char *alpha2_x, const char *alpha2_y)
{
if (!alpha2_x || !alpha2_y)
return false;
if (alpha2_x[0] == alpha2_y[0] &&
alpha2_x[1] == alpha2_y[1])
return true;
return false;
}
static bool regdom_changed(const char *alpha2)
{
if (!cfg80211_regdomain)
return true;
if (alpha2_equal(cfg80211_regdomain->alpha2, alpha2))
return false;
return true;
}
/**
* country_ie_integrity_changes - tells us if the country IE has changed
* @checksum: checksum of country IE of fields we are interested in
*
* If the country IE has not changed you can ignore it safely. This is
* useful to determine if two devices are seeing two different country IEs
* even on the same alpha2. Note that this will return false if no IE has
* been set on the wireless core yet.
*/
static bool country_ie_integrity_changes(u32 checksum)
{
/* If no IE has been set then the checksum doesn't change */
if (unlikely(!last_request->country_ie_checksum))
return false;
if (unlikely(last_request->country_ie_checksum != checksum))
return true;
return false;
}
/* This lets us keep regulatory code which is updated on a regulatory
* basis in userspace. */
static int call_crda(const char *alpha2)
{
char country_env[9 + 2] = "COUNTRY=";
char *envp[] = {
country_env,
NULL
};
if (!is_world_regdom((char *) alpha2))
printk(KERN_INFO "cfg80211: Calling CRDA for country: %c%c\n",
alpha2[0], alpha2[1]);
else
printk(KERN_INFO "cfg80211: Calling CRDA to update world "
"regulatory domain\n");
country_env[8] = alpha2[0];
country_env[9] = alpha2[1];
return kobject_uevent_env(&reg_pdev->dev.kobj, KOBJ_CHANGE, envp);
}
/* Used by nl80211 before kmalloc'ing our regulatory domain */
bool reg_is_valid_request(const char *alpha2)
{
if (!last_request)
return false;
return alpha2_equal(last_request->alpha2, alpha2);
}
/* Sanity check on a regulatory rule */
static bool is_valid_reg_rule(const struct ieee80211_reg_rule *rule)
{
const struct ieee80211_freq_range *freq_range = &rule->freq_range;
u32 freq_diff;
if (freq_range->start_freq_khz <= 0 || freq_range->end_freq_khz <= 0)
return false;
if (freq_range->start_freq_khz > freq_range->end_freq_khz)
return false;
freq_diff = freq_range->end_freq_khz - freq_range->start_freq_khz;
if (freq_diff <= 0 || freq_range->max_bandwidth_khz > freq_diff)
return false;
return true;
}
static bool is_valid_rd(const struct ieee80211_regdomain *rd)
{
const struct ieee80211_reg_rule *reg_rule = NULL;
unsigned int i;
if (!rd->n_reg_rules)
return false;
if (WARN_ON(rd->n_reg_rules > NL80211_MAX_SUPP_REG_RULES))
return false;
for (i = 0; i < rd->n_reg_rules; i++) {
reg_rule = &rd->reg_rules[i];
if (!is_valid_reg_rule(reg_rule))
return false;
}
return true;
}
/* Returns value in KHz */
static u32 freq_max_bandwidth(const struct ieee80211_freq_range *freq_range,
u32 freq)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(supported_bandwidths); i++) {
u32 start_freq_khz = freq - supported_bandwidths[i]/2;
u32 end_freq_khz = freq + supported_bandwidths[i]/2;
if (start_freq_khz >= freq_range->start_freq_khz &&
end_freq_khz <= freq_range->end_freq_khz)
return supported_bandwidths[i];
}
return 0;
}
/**
* freq_in_rule_band - tells us if a frequency is in a frequency band
* @freq_range: frequency rule we want to query
* @freq_khz: frequency we are inquiring about
*
* This lets us know if a specific frequency rule is or is not relevant to
* a specific frequency's band. Bands are device specific and artificial
* definitions (the "2.4 GHz band" and the "5 GHz band"), however it is
* safe for now to assume that a frequency rule should not be part of a
* frequency's band if the start freq or end freq are off by more than 2 GHz.
* This resolution can be lowered and should be considered as we add
* regulatory rule support for other "bands".
**/
static bool freq_in_rule_band(const struct ieee80211_freq_range *freq_range,
u32 freq_khz)
{
#define ONE_GHZ_IN_KHZ 1000000
if (abs(freq_khz - freq_range->start_freq_khz) <= (2 * ONE_GHZ_IN_KHZ))
return true;
if (abs(freq_khz - freq_range->end_freq_khz) <= (2 * ONE_GHZ_IN_KHZ))
return true;
return false;
#undef ONE_GHZ_IN_KHZ
}
/* Converts a country IE to a regulatory domain. A regulatory domain
* structure has a lot of information which the IE doesn't yet have,
* so for the other values we use upper max values as we will intersect
* with our userspace regulatory agent to get lower bounds. */
static struct ieee80211_regdomain *country_ie_2_rd(
u8 *country_ie,
u8 country_ie_len,
u32 *checksum)
{
struct ieee80211_regdomain *rd = NULL;
unsigned int i = 0;
char alpha2[2];
u32 flags = 0;
u32 num_rules = 0, size_of_regd = 0;
u8 *triplets_start = NULL;
u8 len_at_triplet = 0;
/* the last channel we have registered in a subband (triplet) */
int last_sub_max_channel = 0;
*checksum = 0xDEADBEEF;
/* Country IE requirements */
BUG_ON(country_ie_len < IEEE80211_COUNTRY_IE_MIN_LEN ||
country_ie_len & 0x01);
alpha2[0] = country_ie[0];
alpha2[1] = country_ie[1];
/*
* Third octet can be:
* 'I' - Indoor
* 'O' - Outdoor
*
* anything else we assume is no restrictions
*/
if (country_ie[2] == 'I')
flags = NL80211_RRF_NO_OUTDOOR;
else if (country_ie[2] == 'O')
flags = NL80211_RRF_NO_INDOOR;
country_ie += 3;
country_ie_len -= 3;
triplets_start = country_ie;
len_at_triplet = country_ie_len;
*checksum ^= ((flags ^ alpha2[0] ^ alpha2[1]) << 8);
/* We need to build a reg rule for each triplet, but first we must
* calculate the number of reg rules we will need. We will need one
* for each channel subband */
while (country_ie_len >= 3) {
int end_channel = 0;
struct ieee80211_country_ie_triplet *triplet =
(struct ieee80211_country_ie_triplet *) country_ie;
int cur_sub_max_channel = 0, cur_channel = 0;
if (triplet->ext.reg_extension_id >=
IEEE80211_COUNTRY_EXTENSION_ID) {
country_ie += 3;
country_ie_len -= 3;
continue;
}
/* 2 GHz */
if (triplet->chans.first_channel <= 14)
end_channel = triplet->chans.first_channel +
triplet->chans.num_channels;
else
/*
* 5 GHz -- For example in country IEs if the first
* channel given is 36 and the number of channels is 4
* then the individual channel numbers defined for the
* 5 GHz PHY by these parameters are: 36, 40, 44, and 48
* and not 36, 37, 38, 39.
*
* See: http://tinyurl.com/11d-clarification
*/
end_channel = triplet->chans.first_channel +
(4 * (triplet->chans.num_channels - 1));
cur_channel = triplet->chans.first_channel;
cur_sub_max_channel = end_channel;
/* Basic sanity check */
if (cur_sub_max_channel < cur_channel)
return NULL;
/* Do not allow overlapping channels. Also channels
* passed in each subband must be monotonically
* increasing */
if (last_sub_max_channel) {
if (cur_channel <= last_sub_max_channel)
return NULL;
if (cur_sub_max_channel <= last_sub_max_channel)
return NULL;
}
/* When dot11RegulatoryClassesRequired is supported
* we can throw ext triplets as part of this soup,
* for now we don't care when those change as we
* don't support them */
*checksum ^= ((cur_channel ^ cur_sub_max_channel) << 8) |
((cur_sub_max_channel ^ cur_sub_max_channel) << 16) |
((triplet->chans.max_power ^ cur_sub_max_channel) << 24);
last_sub_max_channel = cur_sub_max_channel;
country_ie += 3;
country_ie_len -= 3;
num_rules++;
/* Note: this is not a IEEE requirement but
* simply a memory requirement */
if (num_rules > NL80211_MAX_SUPP_REG_RULES)
return NULL;
}
country_ie = triplets_start;
country_ie_len = len_at_triplet;
size_of_regd = sizeof(struct ieee80211_regdomain) +
(num_rules * sizeof(struct ieee80211_reg_rule));
rd = kzalloc(size_of_regd, GFP_KERNEL);
if (!rd)
return NULL;
rd->n_reg_rules = num_rules;
rd->alpha2[0] = alpha2[0];
rd->alpha2[1] = alpha2[1];
/* This time around we fill in the rd */
while (country_ie_len >= 3) {
int end_channel = 0;
struct ieee80211_country_ie_triplet *triplet =
(struct ieee80211_country_ie_triplet *) country_ie;
struct ieee80211_reg_rule *reg_rule = NULL;
struct ieee80211_freq_range *freq_range = NULL;
struct ieee80211_power_rule *power_rule = NULL;
/* Must parse if dot11RegulatoryClassesRequired is true,
* we don't support this yet */
if (triplet->ext.reg_extension_id >=
IEEE80211_COUNTRY_EXTENSION_ID) {
country_ie += 3;
country_ie_len -= 3;
continue;
}
reg_rule = &rd->reg_rules[i];
freq_range = &reg_rule->freq_range;
power_rule = &reg_rule->power_rule;
reg_rule->flags = flags;
/* 2 GHz */
if (triplet->chans.first_channel <= 14)
end_channel = triplet->chans.first_channel +
triplet->chans.num_channels;
else
end_channel = triplet->chans.first_channel +
(4 * (triplet->chans.num_channels - 1));
/* The +10 is since the regulatory domain expects
* the actual band edge, not the center of freq for
* its start and end freqs, assuming 20 MHz bandwidth on
* the channels passed */
freq_range->start_freq_khz =
MHZ_TO_KHZ(ieee80211_channel_to_frequency(
triplet->chans.first_channel) - 10);
freq_range->end_freq_khz =
MHZ_TO_KHZ(ieee80211_channel_to_frequency(
end_channel) + 10);
/* Large arbitrary values, we intersect later */
/* Increment this if we ever support >= 40 MHz channels
* in IEEE 802.11 */
freq_range->max_bandwidth_khz = MHZ_TO_KHZ(40);
power_rule->max_antenna_gain = DBI_TO_MBI(100);
power_rule->max_eirp = DBM_TO_MBM(100);
country_ie += 3;
country_ie_len -= 3;
i++;
BUG_ON(i > NL80211_MAX_SUPP_REG_RULES);
}
return rd;
}
/* Helper for regdom_intersect(), this does the real
* mathematical intersection fun */
static int reg_rules_intersect(
const struct ieee80211_reg_rule *rule1,
const struct ieee80211_reg_rule *rule2,
struct ieee80211_reg_rule *intersected_rule)
{
const struct ieee80211_freq_range *freq_range1, *freq_range2;
struct ieee80211_freq_range *freq_range;
const struct ieee80211_power_rule *power_rule1, *power_rule2;
struct ieee80211_power_rule *power_rule;
u32 freq_diff;
freq_range1 = &rule1->freq_range;
freq_range2 = &rule2->freq_range;
freq_range = &intersected_rule->freq_range;
power_rule1 = &rule1->power_rule;
power_rule2 = &rule2->power_rule;
power_rule = &intersected_rule->power_rule;
freq_range->start_freq_khz = max(freq_range1->start_freq_khz,
freq_range2->start_freq_khz);
freq_range->end_freq_khz = min(freq_range1->end_freq_khz,
freq_range2->end_freq_khz);
freq_range->max_bandwidth_khz = min(freq_range1->max_bandwidth_khz,
freq_range2->max_bandwidth_khz);
freq_diff = freq_range->end_freq_khz - freq_range->start_freq_khz;
if (freq_range->max_bandwidth_khz > freq_diff)
freq_range->max_bandwidth_khz = freq_diff;
power_rule->max_eirp = min(power_rule1->max_eirp,
power_rule2->max_eirp);
power_rule->max_antenna_gain = min(power_rule1->max_antenna_gain,
power_rule2->max_antenna_gain);
intersected_rule->flags = (rule1->flags | rule2->flags);
if (!is_valid_reg_rule(intersected_rule))
return -EINVAL;
return 0;
}
/**
* regdom_intersect - do the intersection between two regulatory domains
* @rd1: first regulatory domain
* @rd2: second regulatory domain
*
* Use this function to get the intersection between two regulatory domains.
* Once completed we will mark the alpha2 for the rd as intersected, "98",
* as no one single alpha2 can represent this regulatory domain.
*
* Returns a pointer to the regulatory domain structure which will hold the
* resulting intersection of rules between rd1 and rd2. We will
* kzalloc() this structure for you.
*/
static struct ieee80211_regdomain *regdom_intersect(
const struct ieee80211_regdomain *rd1,
const struct ieee80211_regdomain *rd2)
{
int r, size_of_regd;
unsigned int x, y;
unsigned int num_rules = 0, rule_idx = 0;
const struct ieee80211_reg_rule *rule1, *rule2;
struct ieee80211_reg_rule *intersected_rule;
struct ieee80211_regdomain *rd;
/* This is just a dummy holder to help us count */
struct ieee80211_reg_rule irule;
/* Uses the stack temporarily for counter arithmetic */
intersected_rule = &irule;
memset(intersected_rule, 0, sizeof(struct ieee80211_reg_rule));
if (!rd1 || !rd2)
return NULL;
/* First we get a count of the rules we'll need, then we actually
* build them. This is to so we can malloc() and free() a
* regdomain once. The reason we use reg_rules_intersect() here
* is it will return -EINVAL if the rule computed makes no sense.
* All rules that do check out OK are valid. */
for (x = 0; x < rd1->n_reg_rules; x++) {
rule1 = &rd1->reg_rules[x];
for (y = 0; y < rd2->n_reg_rules; y++) {
rule2 = &rd2->reg_rules[y];
if (!reg_rules_intersect(rule1, rule2,
intersected_rule))
num_rules++;
memset(intersected_rule, 0,
sizeof(struct ieee80211_reg_rule));
}
}
if (!num_rules)
return NULL;
size_of_regd = sizeof(struct ieee80211_regdomain) +
((num_rules + 1) * sizeof(struct ieee80211_reg_rule));
rd = kzalloc(size_of_regd, GFP_KERNEL);
if (!rd)
return NULL;
for (x = 0; x < rd1->n_reg_rules; x++) {
rule1 = &rd1->reg_rules[x];
for (y = 0; y < rd2->n_reg_rules; y++) {
rule2 = &rd2->reg_rules[y];
/* This time around instead of using the stack lets
* write to the target rule directly saving ourselves
* a memcpy() */
intersected_rule = &rd->reg_rules[rule_idx];
r = reg_rules_intersect(rule1, rule2,
intersected_rule);
/* No need to memset here the intersected rule here as
* we're not using the stack anymore */
if (r)
continue;
rule_idx++;
}
}
if (rule_idx != num_rules) {
kfree(rd);
return NULL;
}
rd->n_reg_rules = num_rules;
rd->alpha2[0] = '9';
rd->alpha2[1] = '8';
return rd;
}
/* XXX: add support for the rest of enum nl80211_reg_rule_flags, we may
* want to just have the channel structure use these */
static u32 map_regdom_flags(u32 rd_flags)
{
u32 channel_flags = 0;
if (rd_flags & NL80211_RRF_PASSIVE_SCAN)
channel_flags |= IEEE80211_CHAN_PASSIVE_SCAN;
if (rd_flags & NL80211_RRF_NO_IBSS)
channel_flags |= IEEE80211_CHAN_NO_IBSS;
if (rd_flags & NL80211_RRF_DFS)
channel_flags |= IEEE80211_CHAN_RADAR;
return channel_flags;
}
/**
* freq_reg_info - get regulatory information for the given frequency
* @center_freq: Frequency in KHz for which we want regulatory information for
* @bandwidth: the bandwidth requirement you have in KHz, if you do not have one
* you can set this to 0. If this frequency is allowed we then set
* this value to the maximum allowed bandwidth.
* @reg_rule: the regulatory rule which we have for this frequency
*
* Use this function to get the regulatory rule for a specific frequency on
* a given wireless device. If the device has a specific regulatory domain
* it wants to follow we respect that unless a country IE has been received
* and processed already.
*
* Returns 0 if it was able to find a valid regulatory rule which does
* apply to the given center_freq otherwise it returns non-zero. It will
* also return -ERANGE if we determine the given center_freq does not even have
* a regulatory rule for a frequency range in the center_freq's band. See
* freq_in_rule_band() for our current definition of a band -- this is purely
* subjective and right now its 802.11 specific.
*/
static int freq_reg_info(u32 center_freq, u32 *bandwidth,
const struct ieee80211_reg_rule **reg_rule)
{
int i;
bool band_rule_found = false;
u32 max_bandwidth = 0;
if (!cfg80211_regdomain)
return -EINVAL;
for (i = 0; i < cfg80211_regdomain->n_reg_rules; i++) {
const struct ieee80211_reg_rule *rr;
const struct ieee80211_freq_range *fr = NULL;
const struct ieee80211_power_rule *pr = NULL;
rr = &cfg80211_regdomain->reg_rules[i];
fr = &rr->freq_range;
pr = &rr->power_rule;
/* We only need to know if one frequency rule was
* was in center_freq's band, that's enough, so lets
* not overwrite it once found */
if (!band_rule_found)
band_rule_found = freq_in_rule_band(fr, center_freq);
max_bandwidth = freq_max_bandwidth(fr, center_freq);
if (max_bandwidth && *bandwidth <= max_bandwidth) {
*reg_rule = rr;
*bandwidth = max_bandwidth;
break;
}
}
if (!band_rule_found)
return -ERANGE;
return !max_bandwidth;
}
static void handle_channel(struct wiphy *wiphy, enum ieee80211_band band,
unsigned int chan_idx)
{
int r;
u32 flags;
u32 max_bandwidth = 0;
const struct ieee80211_reg_rule *reg_rule = NULL;
const struct ieee80211_power_rule *power_rule = NULL;
struct ieee80211_supported_band *sband;
struct ieee80211_channel *chan;
sband = wiphy->bands[band];
BUG_ON(chan_idx >= sband->n_channels);
chan = &sband->channels[chan_idx];
flags = chan->orig_flags;
r = freq_reg_info(MHZ_TO_KHZ(chan->center_freq),
&max_bandwidth, &reg_rule);
if (r) {
/* This means no regulatory rule was found in the country IE
* with a frequency range on the center_freq's band, since
* IEEE-802.11 allows for a country IE to have a subset of the
* regulatory information provided in a country we ignore
* disabling the channel unless at least one reg rule was
* found on the center_freq's band. For details see this
* clarification:
*
* http://tinyurl.com/11d-clarification
*/
if (r == -ERANGE &&
last_request->initiator == REGDOM_SET_BY_COUNTRY_IE) {
#ifdef CONFIG_CFG80211_REG_DEBUG
printk(KERN_DEBUG "cfg80211: Leaving channel %d MHz "
"intact on %s - no rule found in band on "
"Country IE\n",
chan->center_freq, wiphy_name(wiphy));
#endif
} else {
/* In this case we know the country IE has at least one reg rule
* for the band so we respect its band definitions */
#ifdef CONFIG_CFG80211_REG_DEBUG
if (last_request->initiator == REGDOM_SET_BY_COUNTRY_IE)
printk(KERN_DEBUG "cfg80211: Disabling "
"channel %d MHz on %s due to "
"Country IE\n",
chan->center_freq, wiphy_name(wiphy));
#endif
flags |= IEEE80211_CHAN_DISABLED;
chan->flags = flags;
}
return;
}
power_rule = &reg_rule->power_rule;
chan->flags = flags | map_regdom_flags(reg_rule->flags);
chan->max_antenna_gain = min(chan->orig_mag,
(int) MBI_TO_DBI(power_rule->max_antenna_gain));
chan->max_bandwidth = KHZ_TO_MHZ(max_bandwidth);
if (chan->orig_mpwr)
chan->max_power = min(chan->orig_mpwr,
(int) MBM_TO_DBM(power_rule->max_eirp));
else
chan->max_power = (int) MBM_TO_DBM(power_rule->max_eirp);
}
static void handle_band(struct wiphy *wiphy, enum ieee80211_band band)
{
unsigned int i;
struct ieee80211_supported_band *sband;
BUG_ON(!wiphy->bands[band]);
sband = wiphy->bands[band];
for (i = 0; i < sband->n_channels; i++)
handle_channel(wiphy, band, i);
}
static bool ignore_reg_update(struct wiphy *wiphy, enum reg_set_by setby)
{
if (!last_request)
return true;
if (setby == REGDOM_SET_BY_CORE &&
wiphy->fw_handles_regulatory)
return true;
return false;
}
static void update_all_wiphy_regulatory(enum reg_set_by setby)
{
struct cfg80211_registered_device *drv;
list_for_each_entry(drv, &cfg80211_drv_list, list)
if (!ignore_reg_update(&drv->wiphy, setby))
wiphy_update_regulatory(&drv->wiphy, setby);
}
void wiphy_update_regulatory(struct wiphy *wiphy, enum reg_set_by setby)
{
enum ieee80211_band band;
for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
if (wiphy->bands[band])
handle_band(wiphy, band);
if (wiphy->reg_notifier)
wiphy->reg_notifier(wiphy, setby);
}
}
/* Return value which can be used by ignore_request() to indicate
* it has been determined we should intersect two regulatory domains */
#define REG_INTERSECT 1
/* This has the logic which determines when a new request
* should be ignored. */
static int ignore_request(struct wiphy *wiphy, enum reg_set_by set_by,
const char *alpha2)
{
/* All initial requests are respected */
if (!last_request)
return 0;
switch (set_by) {
case REGDOM_SET_BY_INIT:
return -EINVAL;
case REGDOM_SET_BY_CORE:
/*
* Always respect new wireless core hints, should only happen
* when updating the world regulatory domain at init.
*/
return 0;
case REGDOM_SET_BY_COUNTRY_IE:
if (unlikely(!is_an_alpha2(alpha2)))
return -EINVAL;
if (last_request->initiator == REGDOM_SET_BY_COUNTRY_IE) {
if (last_request->wiphy != wiphy) {
/*
* Two cards with two APs claiming different
* different Country IE alpha2s. We could
* intersect them, but that seems unlikely
* to be correct. Reject second one for now.
*/
if (!alpha2_equal(alpha2,
cfg80211_regdomain->alpha2))
return -EOPNOTSUPP;
return -EALREADY;
}
/* Two consecutive Country IE hints on the same wiphy.
* This should be picked up early by the driver/stack */
if (WARN_ON(!alpha2_equal(cfg80211_regdomain->alpha2,
alpha2)))
return 0;
return -EALREADY;
}
return REG_INTERSECT;
case REGDOM_SET_BY_DRIVER:
if (last_request->initiator == REGDOM_SET_BY_DRIVER)
return -EALREADY;
return 0;
case REGDOM_SET_BY_USER:
if (last_request->initiator == REGDOM_SET_BY_COUNTRY_IE)
return REG_INTERSECT;
/* If the user knows better the user should set the regdom
* to their country before the IE is picked up */
if (last_request->initiator == REGDOM_SET_BY_USER &&
last_request->intersect)
return -EOPNOTSUPP;
return 0;
}
return -EINVAL;
}
/* Caller must hold &cfg80211_drv_mutex */
int __regulatory_hint(struct wiphy *wiphy, enum reg_set_by set_by,
const char *alpha2,
u32 country_ie_checksum,
enum environment_cap env)
{
struct regulatory_request *request;
bool intersect = false;
int r = 0;
r = ignore_request(wiphy, set_by, alpha2);
if (r == REG_INTERSECT)
intersect = true;
else if (r)
return r;
request = kzalloc(sizeof(struct regulatory_request),
GFP_KERNEL);
if (!request)
return -ENOMEM;
request->alpha2[0] = alpha2[0];
request->alpha2[1] = alpha2[1];
request->initiator = set_by;
request->wiphy = wiphy;
request->intersect = intersect;
request->country_ie_checksum = country_ie_checksum;
request->country_ie_env = env;
kfree(last_request);
last_request = request;
/*
* Note: When CONFIG_WIRELESS_OLD_REGULATORY is enabled
* AND if CRDA is NOT present nothing will happen, if someone
* wants to bother with 11d with OLD_REG you can add a timer.
* If after x amount of time nothing happens you can call:
*
* return set_regdom(country_ie_regdomain);
*
* to intersect with the static rd
*/
return call_crda(alpha2);
}
void regulatory_hint(struct wiphy *wiphy, const char *alpha2)
{
BUG_ON(!alpha2);
mutex_lock(&cfg80211_drv_mutex);
__regulatory_hint(wiphy, REGDOM_SET_BY_DRIVER, alpha2, 0, ENVIRON_ANY);
mutex_unlock(&cfg80211_drv_mutex);
}
EXPORT_SYMBOL(regulatory_hint);
static bool reg_same_country_ie_hint(struct wiphy *wiphy,
u32 country_ie_checksum)
{
if (!last_request->wiphy)
return false;
if (likely(last_request->wiphy != wiphy))
return !country_ie_integrity_changes(country_ie_checksum);
/* We should not have let these through at this point, they
* should have been picked up earlier by the first alpha2 check
* on the device */
if (WARN_ON(!country_ie_integrity_changes(country_ie_checksum)))
return true;
return false;
}
void regulatory_hint_11d(struct wiphy *wiphy,
u8 *country_ie,
u8 country_ie_len)
{
struct ieee80211_regdomain *rd = NULL;
char alpha2[2];
u32 checksum = 0;
enum environment_cap env = ENVIRON_ANY;
if (!last_request)
return;
mutex_lock(&cfg80211_drv_mutex);
/* IE len must be evenly divisible by 2 */
if (country_ie_len & 0x01)
goto out;
if (country_ie_len < IEEE80211_COUNTRY_IE_MIN_LEN)
goto out;
/* Pending country IE processing, this can happen after we
* call CRDA and wait for a response if a beacon was received before
* we were able to process the last regulatory_hint_11d() call */
if (country_ie_regdomain)
goto out;
alpha2[0] = country_ie[0];
alpha2[1] = country_ie[1];
if (country_ie[2] == 'I')
env = ENVIRON_INDOOR;
else if (country_ie[2] == 'O')
env = ENVIRON_OUTDOOR;
/* We will run this for *every* beacon processed for the BSSID, so
* we optimize an early check to exit out early if we don't have to
* do anything */
if (likely(last_request->wiphy)) {
struct cfg80211_registered_device *drv_last_ie;
drv_last_ie = wiphy_to_dev(last_request->wiphy);
/* Lets keep this simple -- we trust the first AP
* after we intersect with CRDA */
if (likely(last_request->wiphy == wiphy)) {
/* Ignore IEs coming in on this wiphy with
* the same alpha2 and environment cap */
if (likely(alpha2_equal(drv_last_ie->country_ie_alpha2,
alpha2) &&
env == drv_last_ie->env)) {
goto out;
}
/* the wiphy moved on to another BSSID or the AP
* was reconfigured. XXX: We need to deal with the
* case where the user suspends and goes to goes
* to another country, and then gets IEs from an
* AP with different settings */
goto out;
} else {
/* Ignore IEs coming in on two separate wiphys with
* the same alpha2 and environment cap */
if (likely(alpha2_equal(drv_last_ie->country_ie_alpha2,
alpha2) &&
env == drv_last_ie->env)) {
goto out;
}
/* We could potentially intersect though */
goto out;
}
}
rd = country_ie_2_rd(country_ie, country_ie_len, &checksum);
if (!rd)
goto out;
/* This will not happen right now but we leave it here for the
* the future when we want to add suspend/resume support and having
* the user move to another country after doing so, or having the user
* move to another AP. Right now we just trust the first AP. This is why
* this is marked as likley(). If we hit this before we add this support
* we want to be informed of it as it would indicate a mistake in the
* current design */
if (likely(WARN_ON(reg_same_country_ie_hint(wiphy, checksum))))
goto out;
/* We keep this around for when CRDA comes back with a response so
* we can intersect with that */
country_ie_regdomain = rd;
__regulatory_hint(wiphy, REGDOM_SET_BY_COUNTRY_IE,
country_ie_regdomain->alpha2, checksum, env);
out:
mutex_unlock(&cfg80211_drv_mutex);
}
EXPORT_SYMBOL(regulatory_hint_11d);
static void print_rd_rules(const struct ieee80211_regdomain *rd)
{
unsigned int i;
const struct ieee80211_reg_rule *reg_rule = NULL;
const struct ieee80211_freq_range *freq_range = NULL;
const struct ieee80211_power_rule *power_rule = NULL;
printk(KERN_INFO "\t(start_freq - end_freq @ bandwidth), "
"(max_antenna_gain, max_eirp)\n");
for (i = 0; i < rd->n_reg_rules; i++) {
reg_rule = &rd->reg_rules[i];
freq_range = &reg_rule->freq_range;
power_rule = &reg_rule->power_rule;
/* There may not be documentation for max antenna gain
* in certain regions */
if (power_rule->max_antenna_gain)
printk(KERN_INFO "\t(%d KHz - %d KHz @ %d KHz), "
"(%d mBi, %d mBm)\n",
freq_range->start_freq_khz,
freq_range->end_freq_khz,
freq_range->max_bandwidth_khz,
power_rule->max_antenna_gain,
power_rule->max_eirp);
else
printk(KERN_INFO "\t(%d KHz - %d KHz @ %d KHz), "
"(N/A, %d mBm)\n",
freq_range->start_freq_khz,
freq_range->end_freq_khz,
freq_range->max_bandwidth_khz,
power_rule->max_eirp);
}
}
static void print_regdomain(const struct ieee80211_regdomain *rd)
{
if (is_intersected_alpha2(rd->alpha2)) {
struct wiphy *wiphy = NULL;
struct cfg80211_registered_device *drv;
if (last_request->initiator == REGDOM_SET_BY_COUNTRY_IE) {
if (last_request->wiphy) {
wiphy = last_request->wiphy;
drv = wiphy_to_dev(wiphy);
printk(KERN_INFO "cfg80211: Current regulatory "
"domain updated by AP to: %c%c\n",
drv->country_ie_alpha2[0],
drv->country_ie_alpha2[1]);
} else
printk(KERN_INFO "cfg80211: Current regulatory "
"domain intersected: \n");
} else
printk(KERN_INFO "cfg80211: Current regulatory "
"intersected: \n");
} else if (is_world_regdom(rd->alpha2))
printk(KERN_INFO "cfg80211: World regulatory "
"domain updated:\n");
else {
if (is_unknown_alpha2(rd->alpha2))
printk(KERN_INFO "cfg80211: Regulatory domain "
"changed to driver built-in settings "
"(unknown country)\n");
else
printk(KERN_INFO "cfg80211: Regulatory domain "
"changed to country: %c%c\n",
rd->alpha2[0], rd->alpha2[1]);
}
print_rd_rules(rd);
}
static void print_regdomain_info(const struct ieee80211_regdomain *rd)
{
printk(KERN_INFO "cfg80211: Regulatory domain: %c%c\n",
rd->alpha2[0], rd->alpha2[1]);
print_rd_rules(rd);
}
#ifdef CONFIG_CFG80211_REG_DEBUG
static void reg_country_ie_process_debug(
const struct ieee80211_regdomain *rd,
const struct ieee80211_regdomain *country_ie_regdomain,
const struct ieee80211_regdomain *intersected_rd)
{
printk(KERN_DEBUG "cfg80211: Received country IE:\n");
print_regdomain_info(country_ie_regdomain);
printk(KERN_DEBUG "cfg80211: CRDA thinks this should applied:\n");
print_regdomain_info(rd);
if (intersected_rd) {
printk(KERN_DEBUG "cfg80211: We intersect both of these "
"and get:\n");
print_regdomain_info(intersected_rd);
return;
}
printk(KERN_DEBUG "cfg80211: Intersection between both failed\n");
}
#else
static inline void reg_country_ie_process_debug(
const struct ieee80211_regdomain *rd,
const struct ieee80211_regdomain *country_ie_regdomain,
const struct ieee80211_regdomain *intersected_rd)
{
}
#endif
/* Takes ownership of rd only if it doesn't fail */
static int __set_regdom(const struct ieee80211_regdomain *rd)
{
const struct ieee80211_regdomain *intersected_rd = NULL;
struct cfg80211_registered_device *drv = NULL;
struct wiphy *wiphy = NULL;
/* Some basic sanity checks first */
if (is_world_regdom(rd->alpha2)) {
if (WARN_ON(!reg_is_valid_request(rd->alpha2)))
return -EINVAL;
update_world_regdomain(rd);
return 0;
}
if (!is_alpha2_set(rd->alpha2) && !is_an_alpha2(rd->alpha2) &&
!is_unknown_alpha2(rd->alpha2))
return -EINVAL;
if (!last_request)
return -EINVAL;
/* Lets only bother proceeding on the same alpha2 if the current
* rd is non static (it means CRDA was present and was used last)
* and the pending request came in from a country IE */
if (last_request->initiator != REGDOM_SET_BY_COUNTRY_IE) {
/* If someone else asked us to change the rd lets only bother
* checking if the alpha2 changes if CRDA was already called */
if (!is_old_static_regdom(cfg80211_regdomain) &&
!regdom_changed(rd->alpha2))
return -EINVAL;
}
wiphy = last_request->wiphy;
/* Now lets set the regulatory domain, update all driver channels
* and finally inform them of what we have done, in case they want
* to review or adjust their own settings based on their own
* internal EEPROM data */
if (WARN_ON(!reg_is_valid_request(rd->alpha2)))
return -EINVAL;
if (!is_valid_rd(rd)) {
printk(KERN_ERR "cfg80211: Invalid "
"regulatory domain detected:\n");
print_regdomain_info(rd);
return -EINVAL;
}
if (!last_request->intersect) {
reset_regdomains();
cfg80211_regdomain = rd;
return 0;
}
/* Intersection requires a bit more work */
if (last_request->initiator != REGDOM_SET_BY_COUNTRY_IE) {
intersected_rd = regdom_intersect(rd, cfg80211_regdomain);
if (!intersected_rd)
return -EINVAL;
/* We can trash what CRDA provided now */
kfree(rd);
rd = NULL;
reset_regdomains();
cfg80211_regdomain = intersected_rd;
return 0;
}
/*
* Country IE requests are handled a bit differently, we intersect
* the country IE rd with what CRDA believes that country should have
*/
BUG_ON(!country_ie_regdomain);
if (rd != country_ie_regdomain) {
/* Intersect what CRDA returned and our what we
* had built from the Country IE received */
intersected_rd = regdom_intersect(rd, country_ie_regdomain);
reg_country_ie_process_debug(rd, country_ie_regdomain,
intersected_rd);
kfree(country_ie_regdomain);
country_ie_regdomain = NULL;
} else {
/* This would happen when CRDA was not present and
* OLD_REGULATORY was enabled. We intersect our Country
* IE rd and what was set on cfg80211 originally */
intersected_rd = regdom_intersect(rd, cfg80211_regdomain);
}
if (!intersected_rd)
return -EINVAL;
drv = wiphy_to_dev(wiphy);
drv->country_ie_alpha2[0] = rd->alpha2[0];
drv->country_ie_alpha2[1] = rd->alpha2[1];
drv->env = last_request->country_ie_env;
BUG_ON(intersected_rd == rd);
kfree(rd);
rd = NULL;
reset_regdomains();
cfg80211_regdomain = intersected_rd;
return 0;
}
/* Use this call to set the current regulatory domain. Conflicts with
* multiple drivers can be ironed out later. Caller must've already
* kmalloc'd the rd structure. Caller must hold cfg80211_drv_mutex */
int set_regdom(const struct ieee80211_regdomain *rd)
{
int r;
/* Note that this doesn't update the wiphys, this is done below */
r = __set_regdom(rd);
if (r) {
kfree(rd);
return r;
}
/* This would make this whole thing pointless */
if (!last_request->intersect)
BUG_ON(rd != cfg80211_regdomain);
/* update all wiphys now with the new established regulatory domain */
update_all_wiphy_regulatory(last_request->initiator);
print_regdomain(cfg80211_regdomain);
return r;
}
/* Caller must hold cfg80211_drv_mutex */
void reg_device_remove(struct wiphy *wiphy)
{
if (!last_request || !last_request->wiphy)
return;
if (last_request->wiphy != wiphy)
return;
last_request->wiphy = NULL;
last_request->country_ie_env = ENVIRON_ANY;
}
int regulatory_init(void)
{
int err;
reg_pdev = platform_device_register_simple("regulatory", 0, NULL, 0);
if (IS_ERR(reg_pdev))
return PTR_ERR(reg_pdev);
#ifdef CONFIG_WIRELESS_OLD_REGULATORY
cfg80211_regdomain = static_regdom(ieee80211_regdom);
printk(KERN_INFO "cfg80211: Using static regulatory domain info\n");
print_regdomain_info(cfg80211_regdomain);
/* The old code still requests for a new regdomain and if
* you have CRDA you get it updated, otherwise you get
* stuck with the static values. We ignore "EU" code as
* that is not a valid ISO / IEC 3166 alpha2 */
if (ieee80211_regdom[0] != 'E' || ieee80211_regdom[1] != 'U')
err = __regulatory_hint(NULL, REGDOM_SET_BY_CORE,
ieee80211_regdom, 0, ENVIRON_ANY);
#else
cfg80211_regdomain = cfg80211_world_regdom;
err = __regulatory_hint(NULL, REGDOM_SET_BY_CORE, "00", 0, ENVIRON_ANY);
if (err)
printk(KERN_ERR "cfg80211: calling CRDA failed - "
"unable to update world regulatory domain, "
"using static definition\n");
#endif
return 0;
}
void regulatory_exit(void)
{
mutex_lock(&cfg80211_drv_mutex);
reset_regdomains();
kfree(country_ie_regdomain);
country_ie_regdomain = NULL;
kfree(last_request);
platform_device_unregister(reg_pdev);
mutex_unlock(&cfg80211_drv_mutex);
}
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