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linux/net/wireless/scan.c
Johannes Berg 9853a55ef1 cfg80211: limit scan results cache size 
It's possible to make scanning consume almost arbitrary amounts
of memory, e.g. by sending beacon frames with random BSSIDs at
high rates while somebody is scanning.

Limit the number of BSS table entries we're willing to cache to
1000, limiting maximum memory usage to maybe 4-5MB, but lower
in practice - that would be the case for having both full-sized
beacon and probe response frames for each entry; this seems not
possible in practice, so a limit of 1000 entries will likely be
closer to 0.5 MB.

Cc: stable@vger.kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-11-18 08:44:44 +01:00

1758 lines
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/*
* cfg80211 scan result handling
*
* Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
* Copyright 2013-2014 Intel Mobile Communications GmbH
* Copyright 2016 Intel Deutschland GmbH
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/wireless.h>
#include <linux/nl80211.h>
#include <linux/etherdevice.h>
#include <net/arp.h>
#include <net/cfg80211.h>
#include <net/cfg80211-wext.h>
#include <net/iw_handler.h>
#include "core.h"
#include "nl80211.h"
#include "wext-compat.h"
#include "rdev-ops.h"
/**
* DOC: BSS tree/list structure
*
* At the top level, the BSS list is kept in both a list in each
* registered device (@bss_list) as well as an RB-tree for faster
* lookup. In the RB-tree, entries can be looked up using their
* channel, MESHID, MESHCONF (for MBSSes) or channel, BSSID, SSID
* for other BSSes.
*
* Due to the possibility of hidden SSIDs, there's a second level
* structure, the "hidden_list" and "hidden_beacon_bss" pointer.
* The hidden_list connects all BSSes belonging to a single AP
* that has a hidden SSID, and connects beacon and probe response
* entries. For a probe response entry for a hidden SSID, the
* hidden_beacon_bss pointer points to the BSS struct holding the
* beacon's information.
*
* Reference counting is done for all these references except for
* the hidden_list, so that a beacon BSS struct that is otherwise
* not referenced has one reference for being on the bss_list and
* one for each probe response entry that points to it using the
* hidden_beacon_bss pointer. When a BSS struct that has such a
* pointer is get/put, the refcount update is also propagated to
* the referenced struct, this ensure that it cannot get removed
* while somebody is using the probe response version.
*
* Note that the hidden_beacon_bss pointer never changes, due to
* the reference counting. Therefore, no locking is needed for
* it.
*
* Also note that the hidden_beacon_bss pointer is only relevant
* if the driver uses something other than the IEs, e.g. private
* data stored stored in the BSS struct, since the beacon IEs are
* also linked into the probe response struct.
*/
/*
* Limit the number of BSS entries stored in mac80211. Each one is
* a bit over 4k at most, so this limits to roughly 4-5M of memory.
* If somebody wants to really attack this though, they'd likely
* use small beacons, and only one type of frame, limiting each of
* the entries to a much smaller size (in order to generate more
* entries in total, so overhead is bigger.)
*/
static int bss_entries_limit = 1000;
module_param(bss_entries_limit, int, 0644);
MODULE_PARM_DESC(bss_entries_limit,
"limit to number of scan BSS entries (per wiphy, default 1000)");
#define IEEE80211_SCAN_RESULT_EXPIRE (30 * HZ)
static void bss_free(struct cfg80211_internal_bss *bss)
{
struct cfg80211_bss_ies *ies;
if (WARN_ON(atomic_read(&bss->hold)))
return;
ies = (void *)rcu_access_pointer(bss->pub.beacon_ies);
if (ies && !bss->pub.hidden_beacon_bss)
kfree_rcu(ies, rcu_head);
ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies);
if (ies)
kfree_rcu(ies, rcu_head);
/*
* This happens when the module is removed, it doesn't
* really matter any more save for completeness
*/
if (!list_empty(&bss->hidden_list))
list_del(&bss->hidden_list);
kfree(bss);
}
static inline void bss_ref_get(struct cfg80211_registered_device *rdev,
struct cfg80211_internal_bss *bss)
{
lockdep_assert_held(&rdev->bss_lock);
bss->refcount++;
if (bss->pub.hidden_beacon_bss) {
bss = container_of(bss->pub.hidden_beacon_bss,
struct cfg80211_internal_bss,
pub);
bss->refcount++;
}
}
static inline void bss_ref_put(struct cfg80211_registered_device *rdev,
struct cfg80211_internal_bss *bss)
{
lockdep_assert_held(&rdev->bss_lock);
if (bss->pub.hidden_beacon_bss) {
struct cfg80211_internal_bss *hbss;
hbss = container_of(bss->pub.hidden_beacon_bss,
struct cfg80211_internal_bss,
pub);
hbss->refcount--;
if (hbss->refcount == 0)
bss_free(hbss);
}
bss->refcount--;
if (bss->refcount == 0)
bss_free(bss);
}
static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev,
struct cfg80211_internal_bss *bss)
{
lockdep_assert_held(&rdev->bss_lock);
if (!list_empty(&bss->hidden_list)) {
/*
* don't remove the beacon entry if it has
* probe responses associated with it
*/
if (!bss->pub.hidden_beacon_bss)
return false;
/*
* if it's a probe response entry break its
* link to the other entries in the group
*/
list_del_init(&bss->hidden_list);
}
list_del_init(&bss->list);
rb_erase(&bss->rbn, &rdev->bss_tree);
rdev->bss_entries--;
WARN_ONCE((rdev->bss_entries == 0) ^ list_empty(&rdev->bss_list),
"rdev bss entries[%d]/list[empty:%d] corruption\n",
rdev->bss_entries, list_empty(&rdev->bss_list));
bss_ref_put(rdev, bss);
return true;
}
static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev,
unsigned long expire_time)
{
struct cfg80211_internal_bss *bss, *tmp;
bool expired = false;
lockdep_assert_held(&rdev->bss_lock);
list_for_each_entry_safe(bss, tmp, &rdev->bss_list, list) {
if (atomic_read(&bss->hold))
continue;
if (!time_after(expire_time, bss->ts))
continue;
if (__cfg80211_unlink_bss(rdev, bss))
expired = true;
}
if (expired)
rdev->bss_generation++;
}
static bool cfg80211_bss_expire_oldest(struct cfg80211_registered_device *rdev)
{
struct cfg80211_internal_bss *bss, *oldest = NULL;
bool ret;
lockdep_assert_held(&rdev->bss_lock);
list_for_each_entry(bss, &rdev->bss_list, list) {
if (atomic_read(&bss->hold))
continue;
if (!list_empty(&bss->hidden_list) &&
!bss->pub.hidden_beacon_bss)
continue;
if (oldest && time_before(oldest->ts, bss->ts))
continue;
oldest = bss;
}
if (WARN_ON(!oldest))
return false;
/*
* The callers make sure to increase rdev->bss_generation if anything
* gets removed (and a new entry added), so there's no need to also do
* it here.
*/
ret = __cfg80211_unlink_bss(rdev, oldest);
WARN_ON(!ret);
return ret;
}
void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev,
bool send_message)
{
struct cfg80211_scan_request *request;
struct wireless_dev *wdev;
struct sk_buff *msg;
#ifdef CONFIG_CFG80211_WEXT
union iwreq_data wrqu;
#endif
ASSERT_RTNL();
if (rdev->scan_msg) {
nl80211_send_scan_result(rdev, rdev->scan_msg);
rdev->scan_msg = NULL;
return;
}
request = rdev->scan_req;
if (!request)
return;
wdev = request->wdev;
/*
* This must be before sending the other events!
* Otherwise, wpa_supplicant gets completely confused with
* wext events.
*/
if (wdev->netdev)
cfg80211_sme_scan_done(wdev->netdev);
if (!request->info.aborted &&
request->flags & NL80211_SCAN_FLAG_FLUSH) {
/* flush entries from previous scans */
spin_lock_bh(&rdev->bss_lock);
__cfg80211_bss_expire(rdev, request->scan_start);
spin_unlock_bh(&rdev->bss_lock);
}
msg = nl80211_build_scan_msg(rdev, wdev, request->info.aborted);
#ifdef CONFIG_CFG80211_WEXT
if (wdev->netdev && !request->info.aborted) {
memset(&wrqu, 0, sizeof(wrqu));
wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL);
}
#endif
if (wdev->netdev)
dev_put(wdev->netdev);
rdev->scan_req = NULL;
kfree(request);
if (!send_message)
rdev->scan_msg = msg;
else
nl80211_send_scan_result(rdev, msg);
}
void __cfg80211_scan_done(struct work_struct *wk)
{
struct cfg80211_registered_device *rdev;
rdev = container_of(wk, struct cfg80211_registered_device,
scan_done_wk);
rtnl_lock();
___cfg80211_scan_done(rdev, true);
rtnl_unlock();
}
void cfg80211_scan_done(struct cfg80211_scan_request *request,
struct cfg80211_scan_info *info)
{
trace_cfg80211_scan_done(request, info);
WARN_ON(request != wiphy_to_rdev(request->wiphy)->scan_req);
request->info = *info;
request->notified = true;
queue_work(cfg80211_wq, &wiphy_to_rdev(request->wiphy)->scan_done_wk);
}
EXPORT_SYMBOL(cfg80211_scan_done);
void __cfg80211_sched_scan_results(struct work_struct *wk)
{
struct cfg80211_registered_device *rdev;
struct cfg80211_sched_scan_request *request;
rdev = container_of(wk, struct cfg80211_registered_device,
sched_scan_results_wk);
rtnl_lock();
request = rtnl_dereference(rdev->sched_scan_req);
/* we don't have sched_scan_req anymore if the scan is stopping */
if (request) {
if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
/* flush entries from previous scans */
spin_lock_bh(&rdev->bss_lock);
__cfg80211_bss_expire(rdev, request->scan_start);
spin_unlock_bh(&rdev->bss_lock);
request->scan_start = jiffies;
}
nl80211_send_sched_scan_results(rdev, request->dev);
}
rtnl_unlock();
}
void cfg80211_sched_scan_results(struct wiphy *wiphy)
{
trace_cfg80211_sched_scan_results(wiphy);
/* ignore if we're not scanning */
if (rcu_access_pointer(wiphy_to_rdev(wiphy)->sched_scan_req))
queue_work(cfg80211_wq,
&wiphy_to_rdev(wiphy)->sched_scan_results_wk);
}
EXPORT_SYMBOL(cfg80211_sched_scan_results);
void cfg80211_sched_scan_stopped_rtnl(struct wiphy *wiphy)
{
struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
ASSERT_RTNL();
trace_cfg80211_sched_scan_stopped(wiphy);
__cfg80211_stop_sched_scan(rdev, true);
}
EXPORT_SYMBOL(cfg80211_sched_scan_stopped_rtnl);
void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
{
rtnl_lock();
cfg80211_sched_scan_stopped_rtnl(wiphy);
rtnl_unlock();
}
EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
bool driver_initiated)
{
struct cfg80211_sched_scan_request *sched_scan_req;
struct net_device *dev;
ASSERT_RTNL();
if (!rdev->sched_scan_req)
return -ENOENT;
sched_scan_req = rtnl_dereference(rdev->sched_scan_req);
dev = sched_scan_req->dev;
if (!driver_initiated) {
int err = rdev_sched_scan_stop(rdev, dev);
if (err)
return err;
}
nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
RCU_INIT_POINTER(rdev->sched_scan_req, NULL);
kfree_rcu(sched_scan_req, rcu_head);
return 0;
}
void cfg80211_bss_age(struct cfg80211_registered_device *rdev,
unsigned long age_secs)
{
struct cfg80211_internal_bss *bss;
unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
spin_lock_bh(&rdev->bss_lock);
list_for_each_entry(bss, &rdev->bss_list, list)
bss->ts -= age_jiffies;
spin_unlock_bh(&rdev->bss_lock);
}
void cfg80211_bss_expire(struct cfg80211_registered_device *rdev)
{
__cfg80211_bss_expire(rdev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
}
const u8 *cfg80211_find_ie_match(u8 eid, const u8 *ies, int len,
const u8 *match, int match_len,
int match_offset)
{
/* match_offset can't be smaller than 2, unless match_len is
* zero, in which case match_offset must be zero as well.
*/
if (WARN_ON((match_len && match_offset < 2) ||
(!match_len && match_offset)))
return NULL;
while (len >= 2 && len >= ies[1] + 2) {
if ((ies[0] == eid) &&
(ies[1] + 2 >= match_offset + match_len) &&
!memcmp(ies + match_offset, match, match_len))
return ies;
len -= ies[1] + 2;
ies += ies[1] + 2;
}
return NULL;
}
EXPORT_SYMBOL(cfg80211_find_ie_match);
const u8 *cfg80211_find_vendor_ie(unsigned int oui, int oui_type,
const u8 *ies, int len)
{
const u8 *ie;
u8 match[] = { oui >> 16, oui >> 8, oui, oui_type };
int match_len = (oui_type < 0) ? 3 : sizeof(match);
if (WARN_ON(oui_type > 0xff))
return NULL;
ie = cfg80211_find_ie_match(WLAN_EID_VENDOR_SPECIFIC, ies, len,
match, match_len, 2);
if (ie && (ie[1] < 4))
return NULL;
return ie;
}
EXPORT_SYMBOL(cfg80211_find_vendor_ie);
static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
const u8 *ssid, size_t ssid_len)
{
const struct cfg80211_bss_ies *ies;
const u8 *ssidie;
if (bssid && !ether_addr_equal(a->bssid, bssid))
return false;
if (!ssid)
return true;
ies = rcu_access_pointer(a->ies);
if (!ies)
return false;
ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
if (!ssidie)
return false;
if (ssidie[1] != ssid_len)
return false;
return memcmp(ssidie + 2, ssid, ssid_len) == 0;
}
/**
* enum bss_compare_mode - BSS compare mode
* @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
* @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
* @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
*/
enum bss_compare_mode {
BSS_CMP_REGULAR,
BSS_CMP_HIDE_ZLEN,
BSS_CMP_HIDE_NUL,
};
static int cmp_bss(struct cfg80211_bss *a,
struct cfg80211_bss *b,
enum bss_compare_mode mode)
{
const struct cfg80211_bss_ies *a_ies, *b_ies;
const u8 *ie1 = NULL;
const u8 *ie2 = NULL;
int i, r;
if (a->channel != b->channel)
return b->channel->center_freq - a->channel->center_freq;
a_ies = rcu_access_pointer(a->ies);
if (!a_ies)
return -1;
b_ies = rcu_access_pointer(b->ies);
if (!b_ies)
return 1;
if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
a_ies->data, a_ies->len);
if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
b_ies->data, b_ies->len);
if (ie1 && ie2) {
int mesh_id_cmp;
if (ie1[1] == ie2[1])
mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
else
mesh_id_cmp = ie2[1] - ie1[1];
ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
a_ies->data, a_ies->len);
ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
b_ies->data, b_ies->len);
if (ie1 && ie2) {
if (mesh_id_cmp)
return mesh_id_cmp;
if (ie1[1] != ie2[1])
return ie2[1] - ie1[1];
return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
}
}
r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
if (r)
return r;
ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
if (!ie1 && !ie2)
return 0;
/*
* Note that with "hide_ssid", the function returns a match if
* the already-present BSS ("b") is a hidden SSID beacon for
* the new BSS ("a").
*/
/* sort missing IE before (left of) present IE */
if (!ie1)
return -1;
if (!ie2)
return 1;
switch (mode) {
case BSS_CMP_HIDE_ZLEN:
/*
* In ZLEN mode we assume the BSS entry we're
* looking for has a zero-length SSID. So if
* the one we're looking at right now has that,
* return 0. Otherwise, return the difference
* in length, but since we're looking for the
* 0-length it's really equivalent to returning
* the length of the one we're looking at.
*
* No content comparison is needed as we assume
* the content length is zero.
*/
return ie2[1];
case BSS_CMP_REGULAR:
default:
/* sort by length first, then by contents */
if (ie1[1] != ie2[1])
return ie2[1] - ie1[1];
return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
case BSS_CMP_HIDE_NUL:
if (ie1[1] != ie2[1])
return ie2[1] - ie1[1];
/* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
for (i = 0; i < ie2[1]; i++)
if (ie2[i + 2])
return -1;
return 0;
}
}
static bool cfg80211_bss_type_match(u16 capability,
enum nl80211_band band,
enum ieee80211_bss_type bss_type)
{
bool ret = true;
u16 mask, val;
if (bss_type == IEEE80211_BSS_TYPE_ANY)
return ret;
if (band == NL80211_BAND_60GHZ) {
mask = WLAN_CAPABILITY_DMG_TYPE_MASK;
switch (bss_type) {
case IEEE80211_BSS_TYPE_ESS:
val = WLAN_CAPABILITY_DMG_TYPE_AP;
break;
case IEEE80211_BSS_TYPE_PBSS:
val = WLAN_CAPABILITY_DMG_TYPE_PBSS;
break;
case IEEE80211_BSS_TYPE_IBSS:
val = WLAN_CAPABILITY_DMG_TYPE_IBSS;
break;
default:
return false;
}
} else {
mask = WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS;
switch (bss_type) {
case IEEE80211_BSS_TYPE_ESS:
val = WLAN_CAPABILITY_ESS;
break;
case IEEE80211_BSS_TYPE_IBSS:
val = WLAN_CAPABILITY_IBSS;
break;
case IEEE80211_BSS_TYPE_MBSS:
val = 0;
break;
default:
return false;
}
}
ret = ((capability & mask) == val);
return ret;
}
/* Returned bss is reference counted and must be cleaned up appropriately. */
struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
struct ieee80211_channel *channel,
const u8 *bssid,
const u8 *ssid, size_t ssid_len,
enum ieee80211_bss_type bss_type,
enum ieee80211_privacy privacy)
{
struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
struct cfg80211_internal_bss *bss, *res = NULL;
unsigned long now = jiffies;
int bss_privacy;
trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, bss_type,
privacy);
spin_lock_bh(&rdev->bss_lock);
list_for_each_entry(bss, &rdev->bss_list, list) {
if (!cfg80211_bss_type_match(bss->pub.capability,
bss->pub.channel->band, bss_type))
continue;
bss_privacy = (bss->pub.capability & WLAN_CAPABILITY_PRIVACY);
if ((privacy == IEEE80211_PRIVACY_ON && !bss_privacy) ||
(privacy == IEEE80211_PRIVACY_OFF && bss_privacy))
continue;
if (channel && bss->pub.channel != channel)
continue;
if (!is_valid_ether_addr(bss->pub.bssid))
continue;
/* Don't get expired BSS structs */
if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
!atomic_read(&bss->hold))
continue;
if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
res = bss;
bss_ref_get(rdev, res);
break;
}
}
spin_unlock_bh(&rdev->bss_lock);
if (!res)
return NULL;
trace_cfg80211_return_bss(&res->pub);
return &res->pub;
}
EXPORT_SYMBOL(cfg80211_get_bss);
static void rb_insert_bss(struct cfg80211_registered_device *rdev,
struct cfg80211_internal_bss *bss)
{
struct rb_node **p = &rdev->bss_tree.rb_node;
struct rb_node *parent = NULL;
struct cfg80211_internal_bss *tbss;
int cmp;
while (*p) {
parent = *p;
tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
if (WARN_ON(!cmp)) {
/* will sort of leak this BSS */
return;
}
if (cmp < 0)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
rb_link_node(&bss->rbn, parent, p);
rb_insert_color(&bss->rbn, &rdev->bss_tree);
}
static struct cfg80211_internal_bss *
rb_find_bss(struct cfg80211_registered_device *rdev,
struct cfg80211_internal_bss *res,
enum bss_compare_mode mode)
{
struct rb_node *n = rdev->bss_tree.rb_node;
struct cfg80211_internal_bss *bss;
int r;
while (n) {
bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
r = cmp_bss(&res->pub, &bss->pub, mode);
if (r == 0)
return bss;
else if (r < 0)
n = n->rb_left;
else
n = n->rb_right;
}
return NULL;
}
static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev,
struct cfg80211_internal_bss *new)
{
const struct cfg80211_bss_ies *ies;
struct cfg80211_internal_bss *bss;
const u8 *ie;
int i, ssidlen;
u8 fold = 0;
u32 n_entries = 0;
ies = rcu_access_pointer(new->pub.beacon_ies);
if (WARN_ON(!ies))
return false;
ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
if (!ie) {
/* nothing to do */
return true;
}
ssidlen = ie[1];
for (i = 0; i < ssidlen; i++)
fold |= ie[2 + i];
if (fold) {
/* not a hidden SSID */
return true;
}
/* This is the bad part ... */
list_for_each_entry(bss, &rdev->bss_list, list) {
/*
* we're iterating all the entries anyway, so take the
* opportunity to validate the list length accounting
*/
n_entries++;
if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
continue;
if (bss->pub.channel != new->pub.channel)
continue;
if (bss->pub.scan_width != new->pub.scan_width)
continue;
if (rcu_access_pointer(bss->pub.beacon_ies))
continue;
ies = rcu_access_pointer(bss->pub.ies);
if (!ies)
continue;
ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
if (!ie)
continue;
if (ssidlen && ie[1] != ssidlen)
continue;
if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
continue;
if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
list_del(&bss->hidden_list);
/* combine them */
list_add(&bss->hidden_list, &new->hidden_list);
bss->pub.hidden_beacon_bss = &new->pub;
new->refcount += bss->refcount;
rcu_assign_pointer(bss->pub.beacon_ies,
new->pub.beacon_ies);
}
WARN_ONCE(n_entries != rdev->bss_entries,
"rdev bss entries[%d]/list[len:%d] corruption\n",
rdev->bss_entries, n_entries);
return true;
}
/* Returned bss is reference counted and must be cleaned up appropriately. */
static struct cfg80211_internal_bss *
cfg80211_bss_update(struct cfg80211_registered_device *rdev,
struct cfg80211_internal_bss *tmp,
bool signal_valid)
{
struct cfg80211_internal_bss *found = NULL;
if (WARN_ON(!tmp->pub.channel))
return NULL;
tmp->ts = jiffies;
spin_lock_bh(&rdev->bss_lock);
if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
spin_unlock_bh(&rdev->bss_lock);
return NULL;
}
found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR);
if (found) {
/* Update IEs */
if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
const struct cfg80211_bss_ies *old;
old = rcu_access_pointer(found->pub.proberesp_ies);
rcu_assign_pointer(found->pub.proberesp_ies,
tmp->pub.proberesp_ies);
/* Override possible earlier Beacon frame IEs */
rcu_assign_pointer(found->pub.ies,
tmp->pub.proberesp_ies);
if (old)
kfree_rcu((struct cfg80211_bss_ies *)old,
rcu_head);
} else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
const struct cfg80211_bss_ies *old;
struct cfg80211_internal_bss *bss;
if (found->pub.hidden_beacon_bss &&
!list_empty(&found->hidden_list)) {
const struct cfg80211_bss_ies *f;
/*
* The found BSS struct is one of the probe
* response members of a group, but we're
* receiving a beacon (beacon_ies in the tmp
* bss is used). This can only mean that the
* AP changed its beacon from not having an
* SSID to showing it, which is confusing so
* drop this information.
*/
f = rcu_access_pointer(tmp->pub.beacon_ies);
kfree_rcu((struct cfg80211_bss_ies *)f,
rcu_head);
goto drop;
}
old = rcu_access_pointer(found->pub.beacon_ies);
rcu_assign_pointer(found->pub.beacon_ies,
tmp->pub.beacon_ies);
/* Override IEs if they were from a beacon before */
if (old == rcu_access_pointer(found->pub.ies))
rcu_assign_pointer(found->pub.ies,
tmp->pub.beacon_ies);
/* Assign beacon IEs to all sub entries */
list_for_each_entry(bss, &found->hidden_list,
hidden_list) {
const struct cfg80211_bss_ies *ies;
ies = rcu_access_pointer(bss->pub.beacon_ies);
WARN_ON(ies != old);
rcu_assign_pointer(bss->pub.beacon_ies,
tmp->pub.beacon_ies);
}
if (old)
kfree_rcu((struct cfg80211_bss_ies *)old,
rcu_head);
}
found->pub.beacon_interval = tmp->pub.beacon_interval;
/*
* don't update the signal if beacon was heard on
* adjacent channel.
*/
if (signal_valid)
found->pub.signal = tmp->pub.signal;
found->pub.capability = tmp->pub.capability;
found->ts = tmp->ts;
found->ts_boottime = tmp->ts_boottime;
found->parent_tsf = tmp->parent_tsf;
ether_addr_copy(found->parent_bssid, tmp->parent_bssid);
} else {
struct cfg80211_internal_bss *new;
struct cfg80211_internal_bss *hidden;
struct cfg80211_bss_ies *ies;
/*
* create a copy -- the "res" variable that is passed in
* is allocated on the stack since it's not needed in the
* more common case of an update
*/
new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size,
GFP_ATOMIC);
if (!new) {
ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
if (ies)
kfree_rcu(ies, rcu_head);
ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
if (ies)
kfree_rcu(ies, rcu_head);
goto drop;
}
memcpy(new, tmp, sizeof(*new));
new->refcount = 1;
INIT_LIST_HEAD(&new->hidden_list);
if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN);
if (!hidden)
hidden = rb_find_bss(rdev, tmp,
BSS_CMP_HIDE_NUL);
if (hidden) {
new->pub.hidden_beacon_bss = &hidden->pub;
list_add(&new->hidden_list,
&hidden->hidden_list);
hidden->refcount++;
rcu_assign_pointer(new->pub.beacon_ies,
hidden->pub.beacon_ies);
}
} else {
/*
* Ok so we found a beacon, and don't have an entry. If
* it's a beacon with hidden SSID, we might be in for an
* expensive search for any probe responses that should
* be grouped with this beacon for updates ...
*/
if (!cfg80211_combine_bsses(rdev, new)) {
kfree(new);
goto drop;
}
}
if (rdev->bss_entries >= bss_entries_limit &&
!cfg80211_bss_expire_oldest(rdev)) {
kfree(new);
goto drop;
}
list_add_tail(&new->list, &rdev->bss_list);
rdev->bss_entries++;
rb_insert_bss(rdev, new);
found = new;
}
rdev->bss_generation++;
bss_ref_get(rdev, found);
spin_unlock_bh(&rdev->bss_lock);
return found;
drop:
spin_unlock_bh(&rdev->bss_lock);
return NULL;
}
static struct ieee80211_channel *
cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
struct ieee80211_channel *channel)
{
const u8 *tmp;
u32 freq;
int channel_number = -1;
tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
if (tmp && tmp[1] == 1) {
channel_number = tmp[2];
} else {
tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
channel_number = htop->primary_chan;
}
}
if (channel_number < 0)
return channel;
freq = ieee80211_channel_to_frequency(channel_number, channel->band);
channel = ieee80211_get_channel(wiphy, freq);
if (!channel)
return NULL;
if (channel->flags & IEEE80211_CHAN_DISABLED)
return NULL;
return channel;
}
/* Returned bss is reference counted and must be cleaned up appropriately. */
struct cfg80211_bss *
cfg80211_inform_bss_data(struct wiphy *wiphy,
struct cfg80211_inform_bss *data,
enum cfg80211_bss_frame_type ftype,
const u8 *bssid, u64 tsf, u16 capability,
u16 beacon_interval, const u8 *ie, size_t ielen,
gfp_t gfp)
{
struct cfg80211_bss_ies *ies;
struct ieee80211_channel *channel;
struct cfg80211_internal_bss tmp = {}, *res;
int bss_type;
bool signal_valid;
if (WARN_ON(!wiphy))
return NULL;
if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
(data->signal < 0 || data->signal > 100)))
return NULL;
channel = cfg80211_get_bss_channel(wiphy, ie, ielen, data->chan);
if (!channel)
return NULL;
memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
tmp.pub.channel = channel;
tmp.pub.scan_width = data->scan_width;
tmp.pub.signal = data->signal;
tmp.pub.beacon_interval = beacon_interval;
tmp.pub.capability = capability;
tmp.ts_boottime = data->boottime_ns;
/*
* If we do not know here whether the IEs are from a Beacon or Probe
* Response frame, we need to pick one of the options and only use it
* with the driver that does not provide the full Beacon/Probe Response
* frame. Use Beacon frame pointer to avoid indicating that this should
* override the IEs pointer should we have received an earlier
* indication of Probe Response data.
*/
ies = kzalloc(sizeof(*ies) + ielen, gfp);
if (!ies)
return NULL;
ies->len = ielen;
ies->tsf = tsf;
ies->from_beacon = false;
memcpy(ies->data, ie, ielen);
switch (ftype) {
case CFG80211_BSS_FTYPE_BEACON:
ies->from_beacon = true;
/* fall through to assign */
case CFG80211_BSS_FTYPE_UNKNOWN:
rcu_assign_pointer(tmp.pub.beacon_ies, ies);
break;
case CFG80211_BSS_FTYPE_PRESP:
rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
break;
}
rcu_assign_pointer(tmp.pub.ies, ies);
signal_valid = abs(data->chan->center_freq - channel->center_freq) <=
wiphy->max_adj_channel_rssi_comp;
res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
if (!res)
return NULL;
if (channel->band == NL80211_BAND_60GHZ) {
bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
regulatory_hint_found_beacon(wiphy, channel, gfp);
} else {
if (res->pub.capability & WLAN_CAPABILITY_ESS)
regulatory_hint_found_beacon(wiphy, channel, gfp);
}
trace_cfg80211_return_bss(&res->pub);
/* cfg80211_bss_update gives us a referenced result */
return &res->pub;
}
EXPORT_SYMBOL(cfg80211_inform_bss_data);
/* cfg80211_inform_bss_width_frame helper */
struct cfg80211_bss *
cfg80211_inform_bss_frame_data(struct wiphy *wiphy,
struct cfg80211_inform_bss *data,
struct ieee80211_mgmt *mgmt, size_t len,
gfp_t gfp)
{
struct cfg80211_internal_bss tmp = {}, *res;
struct cfg80211_bss_ies *ies;
struct ieee80211_channel *channel;
bool signal_valid;
size_t ielen = len - offsetof(struct ieee80211_mgmt,
u.probe_resp.variable);
int bss_type;
BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
offsetof(struct ieee80211_mgmt, u.beacon.variable));
trace_cfg80211_inform_bss_frame(wiphy, data, mgmt, len);
if (WARN_ON(!mgmt))
return NULL;
if (WARN_ON(!wiphy))
return NULL;
if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
(data->signal < 0 || data->signal > 100)))
return NULL;
if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
return NULL;
channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
ielen, data->chan);
if (!channel)
return NULL;
ies = kzalloc(sizeof(*ies) + ielen, gfp);
if (!ies)
return NULL;
ies->len = ielen;
ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control);
memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
if (ieee80211_is_probe_resp(mgmt->frame_control))
rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
else
rcu_assign_pointer(tmp.pub.beacon_ies, ies);
rcu_assign_pointer(tmp.pub.ies, ies);
memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
tmp.pub.channel = channel;
tmp.pub.scan_width = data->scan_width;
tmp.pub.signal = data->signal;
tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
tmp.ts_boottime = data->boottime_ns;
tmp.parent_tsf = data->parent_tsf;
ether_addr_copy(tmp.parent_bssid, data->parent_bssid);
signal_valid = abs(data->chan->center_freq - channel->center_freq) <=
wiphy->max_adj_channel_rssi_comp;
res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
if (!res)
return NULL;
if (channel->band == NL80211_BAND_60GHZ) {
bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
regulatory_hint_found_beacon(wiphy, channel, gfp);
} else {
if (res->pub.capability & WLAN_CAPABILITY_ESS)
regulatory_hint_found_beacon(wiphy, channel, gfp);
}
trace_cfg80211_return_bss(&res->pub);
/* cfg80211_bss_update gives us a referenced result */
return &res->pub;
}
EXPORT_SYMBOL(cfg80211_inform_bss_frame_data);
void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
{
struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
struct cfg80211_internal_bss *bss;
if (!pub)
return;
bss = container_of(pub, struct cfg80211_internal_bss, pub);
spin_lock_bh(&rdev->bss_lock);
bss_ref_get(rdev, bss);
spin_unlock_bh(&rdev->bss_lock);
}
EXPORT_SYMBOL(cfg80211_ref_bss);
void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
{
struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
struct cfg80211_internal_bss *bss;
if (!pub)
return;
bss = container_of(pub, struct cfg80211_internal_bss, pub);
spin_lock_bh(&rdev->bss_lock);
bss_ref_put(rdev, bss);
spin_unlock_bh(&rdev->bss_lock);
}
EXPORT_SYMBOL(cfg80211_put_bss);
void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
{
struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
struct cfg80211_internal_bss *bss;
if (WARN_ON(!pub))
return;
bss = container_of(pub, struct cfg80211_internal_bss, pub);
spin_lock_bh(&rdev->bss_lock);
if (!list_empty(&bss->list)) {
if (__cfg80211_unlink_bss(rdev, bss))
rdev->bss_generation++;
}
spin_unlock_bh(&rdev->bss_lock);
}
EXPORT_SYMBOL(cfg80211_unlink_bss);
#ifdef CONFIG_CFG80211_WEXT
static struct cfg80211_registered_device *
cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
{
struct cfg80211_registered_device *rdev;
struct net_device *dev;
ASSERT_RTNL();
dev = dev_get_by_index(net, ifindex);
if (!dev)
return ERR_PTR(-ENODEV);
if (dev->ieee80211_ptr)
rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy);
else
rdev = ERR_PTR(-ENODEV);
dev_put(dev);
return rdev;
}
int cfg80211_wext_siwscan(struct net_device *dev,
struct iw_request_info *info,
union iwreq_data *wrqu, char *extra)
{
struct cfg80211_registered_device *rdev;
struct wiphy *wiphy;
struct iw_scan_req *wreq = NULL;
struct cfg80211_scan_request *creq = NULL;
int i, err, n_channels = 0;
enum nl80211_band band;
if (!netif_running(dev))
return -ENETDOWN;
if (wrqu->data.length == sizeof(struct iw_scan_req))
wreq = (struct iw_scan_req *)extra;
rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
if (IS_ERR(rdev))
return PTR_ERR(rdev);
if (rdev->scan_req || rdev->scan_msg) {
err = -EBUSY;
goto out;
}
wiphy = &rdev->wiphy;
/* Determine number of channels, needed to allocate creq */
if (wreq && wreq->num_channels)
n_channels = wreq->num_channels;
else
n_channels = ieee80211_get_num_supported_channels(wiphy);
creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
n_channels * sizeof(void *),
GFP_ATOMIC);
if (!creq) {
err = -ENOMEM;
goto out;
}
creq->wiphy = wiphy;
creq->wdev = dev->ieee80211_ptr;
/* SSIDs come after channels */
creq->ssids = (void *)&creq->channels[n_channels];
creq->n_channels = n_channels;
creq->n_ssids = 1;
creq->scan_start = jiffies;
/* translate "Scan on frequencies" request */
i = 0;
for (band = 0; band < NUM_NL80211_BANDS; band++) {
int j;
if (!wiphy->bands[band])
continue;
for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
/* ignore disabled channels */
if (wiphy->bands[band]->channels[j].flags &
IEEE80211_CHAN_DISABLED)
continue;
/* If we have a wireless request structure and the
* wireless request specifies frequencies, then search
* for the matching hardware channel.
*/
if (wreq && wreq->num_channels) {
int k;
int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
for (k = 0; k < wreq->num_channels; k++) {
struct iw_freq *freq =
&wreq->channel_list[k];
int wext_freq =
cfg80211_wext_freq(freq);
if (wext_freq == wiphy_freq)
goto wext_freq_found;
}
goto wext_freq_not_found;
}
wext_freq_found:
creq->channels[i] = &wiphy->bands[band]->channels[j];
i++;
wext_freq_not_found: ;
}
}
/* No channels found? */
if (!i) {
err = -EINVAL;
goto out;
}
/* Set real number of channels specified in creq->channels[] */
creq->n_channels = i;
/* translate "Scan for SSID" request */
if (wreq) {
if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
err = -EINVAL;
goto out;
}
memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
creq->ssids[0].ssid_len = wreq->essid_len;
}
if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
creq->n_ssids = 0;
}
for (i = 0; i < NUM_NL80211_BANDS; i++)
if (wiphy->bands[i])
creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
eth_broadcast_addr(creq->bssid);
rdev->scan_req = creq;
err = rdev_scan(rdev, creq);
if (err) {
rdev->scan_req = NULL;
/* creq will be freed below */
} else {
nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
/* creq now owned by driver */
creq = NULL;
dev_hold(dev);
}
out:
kfree(creq);
return err;
}
EXPORT_WEXT_HANDLER(cfg80211_wext_siwscan);
static char *ieee80211_scan_add_ies(struct iw_request_info *info,
const struct cfg80211_bss_ies *ies,
char *current_ev, char *end_buf)
{
const u8 *pos, *end, *next;
struct iw_event iwe;
if (!ies)
return current_ev;
/*
* If needed, fragment the IEs buffer (at IE boundaries) into short
* enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
*/
pos = ies->data;
end = pos + ies->len;
while (end - pos > IW_GENERIC_IE_MAX) {
next = pos + 2 + pos[1];
while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
next = next + 2 + next[1];
memset(&iwe, 0, sizeof(iwe));
iwe.cmd = IWEVGENIE;
iwe.u.data.length = next - pos;
current_ev = iwe_stream_add_point_check(info, current_ev,
end_buf, &iwe,
(void *)pos);
if (IS_ERR(current_ev))
return current_ev;
pos = next;
}
if (end > pos) {
memset(&iwe, 0, sizeof(iwe));
iwe.cmd = IWEVGENIE;
iwe.u.data.length = end - pos;
current_ev = iwe_stream_add_point_check(info, current_ev,
end_buf, &iwe,
(void *)pos);
if (IS_ERR(current_ev))
return current_ev;
}
return current_ev;
}
static char *
ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
struct cfg80211_internal_bss *bss, char *current_ev,
char *end_buf)
{
const struct cfg80211_bss_ies *ies;
struct iw_event iwe;
const u8 *ie;
u8 buf[50];
u8 *cfg, *p, *tmp;
int rem, i, sig;
bool ismesh = false;
memset(&iwe, 0, sizeof(iwe));
iwe.cmd = SIOCGIWAP;
iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
IW_EV_ADDR_LEN);
if (IS_ERR(current_ev))
return current_ev;
memset(&iwe, 0, sizeof(iwe));
iwe.cmd = SIOCGIWFREQ;
iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
iwe.u.freq.e = 0;
current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
IW_EV_FREQ_LEN);
if (IS_ERR(current_ev))
return current_ev;
memset(&iwe, 0, sizeof(iwe));
iwe.cmd = SIOCGIWFREQ;
iwe.u.freq.m = bss->pub.channel->center_freq;
iwe.u.freq.e = 6;
current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
IW_EV_FREQ_LEN);
if (IS_ERR(current_ev))
return current_ev;
if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
memset(&iwe, 0, sizeof(iwe));
iwe.cmd = IWEVQUAL;
iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
IW_QUAL_NOISE_INVALID |
IW_QUAL_QUAL_UPDATED;
switch (wiphy->signal_type) {
case CFG80211_SIGNAL_TYPE_MBM:
sig = bss->pub.signal / 100;
iwe.u.qual.level = sig;
iwe.u.qual.updated |= IW_QUAL_DBM;
if (sig < -110) /* rather bad */
sig = -110;
else if (sig > -40) /* perfect */
sig = -40;
/* will give a range of 0 .. 70 */
iwe.u.qual.qual = sig + 110;
break;
case CFG80211_SIGNAL_TYPE_UNSPEC:
iwe.u.qual.level = bss->pub.signal;
/* will give range 0 .. 100 */
iwe.u.qual.qual = bss->pub.signal;
break;
default:
/* not reached */
break;
}
current_ev = iwe_stream_add_event_check(info, current_ev,
end_buf, &iwe,
IW_EV_QUAL_LEN);
if (IS_ERR(current_ev))
return current_ev;
}
memset(&iwe, 0, sizeof(iwe));
iwe.cmd = SIOCGIWENCODE;
if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
else
iwe.u.data.flags = IW_ENCODE_DISABLED;
iwe.u.data.length = 0;
current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
&iwe, "");
if (IS_ERR(current_ev))
return current_ev;
rcu_read_lock();
ies = rcu_dereference(bss->pub.ies);
rem = ies->len;
ie = ies->data;
while (rem >= 2) {
/* invalid data */
if (ie[1] > rem - 2)
break;
switch (ie[0]) {
case WLAN_EID_SSID:
memset(&iwe, 0, sizeof(iwe));
iwe.cmd = SIOCGIWESSID;
iwe.u.data.length = ie[1];
iwe.u.data.flags = 1;
current_ev = iwe_stream_add_point_check(info,
current_ev,
end_buf, &iwe,
(u8 *)ie + 2);
if (IS_ERR(current_ev))
goto unlock;
break;
case WLAN_EID_MESH_ID:
memset(&iwe, 0, sizeof(iwe));
iwe.cmd = SIOCGIWESSID;
iwe.u.data.length = ie[1];
iwe.u.data.flags = 1;
current_ev = iwe_stream_add_point_check(info,
current_ev,
end_buf, &iwe,
(u8 *)ie + 2);
if (IS_ERR(current_ev))
goto unlock;
break;
case WLAN_EID_MESH_CONFIG:
ismesh = true;
if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
break;
cfg = (u8 *)ie + 2;
memset(&iwe, 0, sizeof(iwe));
iwe.cmd = IWEVCUSTOM;
sprintf(buf, "Mesh Network Path Selection Protocol ID: "
"0x%02X", cfg[0]);
iwe.u.data.length = strlen(buf);
current_ev = iwe_stream_add_point_check(info,
current_ev,
end_buf,
&iwe, buf);
if (IS_ERR(current_ev))
goto unlock;
sprintf(buf, "Path Selection Metric ID: 0x%02X",
cfg[1]);
iwe.u.data.length = strlen(buf);
current_ev = iwe_stream_add_point_check(info,
current_ev,
end_buf,
&iwe, buf);
if (IS_ERR(current_ev))
goto unlock;
sprintf(buf, "Congestion Control Mode ID: 0x%02X",
cfg[2]);
iwe.u.data.length = strlen(buf);
current_ev = iwe_stream_add_point_check(info,
current_ev,
end_buf,
&iwe, buf);
if (IS_ERR(current_ev))
goto unlock;
sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
iwe.u.data.length = strlen(buf);
current_ev = iwe_stream_add_point_check(info,
current_ev,
end_buf,
&iwe, buf);
if (IS_ERR(current_ev))
goto unlock;
sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
iwe.u.data.length = strlen(buf);
current_ev = iwe_stream_add_point_check(info,
current_ev,
end_buf,
&iwe, buf);
if (IS_ERR(current_ev))
goto unlock;
sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
iwe.u.data.length = strlen(buf);
current_ev = iwe_stream_add_point_check(info,
current_ev,
end_buf,
&iwe, buf);
if (IS_ERR(current_ev))
goto unlock;
sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
iwe.u.data.length = strlen(buf);
current_ev = iwe_stream_add_point_check(info,
current_ev,
end_buf,
&iwe, buf);
if (IS_ERR(current_ev))
goto unlock;
break;
case WLAN_EID_SUPP_RATES:
case WLAN_EID_EXT_SUPP_RATES:
/* display all supported rates in readable format */
p = current_ev + iwe_stream_lcp_len(info);
memset(&iwe, 0, sizeof(iwe));
iwe.cmd = SIOCGIWRATE;
/* Those two flags are ignored... */
iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
for (i = 0; i < ie[1]; i++) {
iwe.u.bitrate.value =
((ie[i + 2] & 0x7f) * 500000);
tmp = p;
p = iwe_stream_add_value(info, current_ev, p,
end_buf, &iwe,
IW_EV_PARAM_LEN);
if (p == tmp) {
current_ev = ERR_PTR(-E2BIG);
goto unlock;
}
}
current_ev = p;
break;
}
rem -= ie[1] + 2;
ie += ie[1] + 2;
}
if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
ismesh) {
memset(&iwe, 0, sizeof(iwe));
iwe.cmd = SIOCGIWMODE;
if (ismesh)
iwe.u.mode = IW_MODE_MESH;
else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
iwe.u.mode = IW_MODE_MASTER;
else
iwe.u.mode = IW_MODE_ADHOC;
current_ev = iwe_stream_add_event_check(info, current_ev,
end_buf, &iwe,
IW_EV_UINT_LEN);
if (IS_ERR(current_ev))
goto unlock;
}
memset(&iwe, 0, sizeof(iwe));
iwe.cmd = IWEVCUSTOM;
sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
iwe.u.data.length = strlen(buf);
current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
&iwe, buf);
if (IS_ERR(current_ev))
goto unlock;
memset(&iwe, 0, sizeof(iwe));
iwe.cmd = IWEVCUSTOM;
sprintf(buf, " Last beacon: %ums ago",
elapsed_jiffies_msecs(bss->ts));
iwe.u.data.length = strlen(buf);
current_ev = iwe_stream_add_point_check(info, current_ev,
end_buf, &iwe, buf);
if (IS_ERR(current_ev))
goto unlock;
current_ev = ieee80211_scan_add_ies(info, ies, current_ev, end_buf);
unlock:
rcu_read_unlock();
return current_ev;
}
static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
struct iw_request_info *info,
char *buf, size_t len)
{
char *current_ev = buf;
char *end_buf = buf + len;
struct cfg80211_internal_bss *bss;
int err = 0;
spin_lock_bh(&rdev->bss_lock);
cfg80211_bss_expire(rdev);
list_for_each_entry(bss, &rdev->bss_list, list) {
if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
err = -E2BIG;
break;
}
current_ev = ieee80211_bss(&rdev->wiphy, info, bss,
current_ev, end_buf);
if (IS_ERR(current_ev)) {
err = PTR_ERR(current_ev);
break;
}
}
spin_unlock_bh(&rdev->bss_lock);
if (err)
return err;
return current_ev - buf;
}
int cfg80211_wext_giwscan(struct net_device *dev,
struct iw_request_info *info,
struct iw_point *data, char *extra)
{
struct cfg80211_registered_device *rdev;
int res;
if (!netif_running(dev))
return -ENETDOWN;
rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
if (IS_ERR(rdev))
return PTR_ERR(rdev);
if (rdev->scan_req || rdev->scan_msg)
return -EAGAIN;
res = ieee80211_scan_results(rdev, info, extra, data->length);
data->length = 0;
if (res >= 0) {
data->length = res;
res = 0;
}
return res;
}
EXPORT_WEXT_HANDLER(cfg80211_wext_giwscan);
#endif
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