linux/net/wireless/scan.c
Juuso Oikarinen 2b78ac9bfc cfg80211: fix BSS double-unlinking (continued)
This patch adds to the fix "fix BSS double-unlinking"
(commit 3207390a8b) by Johannes Berg.

It turns out, that the double-unlinking scenario can also occur if expired
BSS elements are removed whilst an interface is performing association.

To work around that, replace list_del with list_del_init also in the
"cfg80211_bss_expire" function, so that the check for whether the BSS still is
in the list works correctly in cfg80211_unlink_bss.

Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-03-28 15:42:02 -04:00

1129 lines
28 KiB
C

/*
* cfg80211 scan result handling
*
* Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
*/
#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/iw_handler.h>
#include "core.h"
#include "nl80211.h"
#include "wext-compat.h"
#define IEEE80211_SCAN_RESULT_EXPIRE (15 * HZ)
void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak)
{
struct cfg80211_scan_request *request;
struct net_device *dev;
#ifdef CONFIG_CFG80211_WEXT
union iwreq_data wrqu;
#endif
ASSERT_RDEV_LOCK(rdev);
request = rdev->scan_req;
if (!request)
return;
dev = request->dev;
/*
* This must be before sending the other events!
* Otherwise, wpa_supplicant gets completely confused with
* wext events.
*/
cfg80211_sme_scan_done(dev);
if (request->aborted)
nl80211_send_scan_aborted(rdev, dev);
else
nl80211_send_scan_done(rdev, dev);
#ifdef CONFIG_CFG80211_WEXT
if (!request->aborted) {
memset(&wrqu, 0, sizeof(wrqu));
wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
}
#endif
dev_put(dev);
rdev->scan_req = NULL;
/*
* OK. If this is invoked with "leak" then we can't
* free this ... but we've cleaned it up anyway. The
* driver failed to call the scan_done callback, so
* all bets are off, it might still be trying to use
* the scan request or not ... if it accesses the dev
* in there (it shouldn't anyway) then it may crash.
*/
if (!leak)
kfree(request);
}
void __cfg80211_scan_done(struct work_struct *wk)
{
struct cfg80211_registered_device *rdev;
rdev = container_of(wk, struct cfg80211_registered_device,
scan_done_wk);
cfg80211_lock_rdev(rdev);
___cfg80211_scan_done(rdev, false);
cfg80211_unlock_rdev(rdev);
}
void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
{
WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
request->aborted = aborted;
queue_work(cfg80211_wq, &wiphy_to_dev(request->wiphy)->scan_done_wk);
}
EXPORT_SYMBOL(cfg80211_scan_done);
static void bss_release(struct kref *ref)
{
struct cfg80211_internal_bss *bss;
bss = container_of(ref, struct cfg80211_internal_bss, ref);
if (bss->pub.free_priv)
bss->pub.free_priv(&bss->pub);
if (bss->beacon_ies_allocated)
kfree(bss->pub.beacon_ies);
if (bss->proberesp_ies_allocated)
kfree(bss->pub.proberesp_ies);
BUG_ON(atomic_read(&bss->hold));
kfree(bss);
}
/* must hold dev->bss_lock! */
void cfg80211_bss_age(struct cfg80211_registered_device *dev,
unsigned long age_secs)
{
struct cfg80211_internal_bss *bss;
unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
list_for_each_entry(bss, &dev->bss_list, list) {
bss->ts -= age_jiffies;
}
}
/* must hold dev->bss_lock! */
static void __cfg80211_unlink_bss(struct cfg80211_registered_device *dev,
struct cfg80211_internal_bss *bss)
{
list_del_init(&bss->list);
rb_erase(&bss->rbn, &dev->bss_tree);
kref_put(&bss->ref, bss_release);
}
/* must hold dev->bss_lock! */
void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
{
struct cfg80211_internal_bss *bss, *tmp;
bool expired = false;
list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
if (atomic_read(&bss->hold))
continue;
if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
continue;
__cfg80211_unlink_bss(dev, bss);
expired = true;
}
if (expired)
dev->bss_generation++;
}
const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
{
while (len > 2 && ies[0] != eid) {
len -= ies[1] + 2;
ies += ies[1] + 2;
}
if (len < 2)
return NULL;
if (len < 2 + ies[1])
return NULL;
return ies;
}
EXPORT_SYMBOL(cfg80211_find_ie);
static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
{
const u8 *ie1 = cfg80211_find_ie(num, ies1, len1);
const u8 *ie2 = cfg80211_find_ie(num, ies2, len2);
int r;
if (!ie1 && !ie2)
return 0;
if (!ie1 || !ie2)
return -1;
r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
if (r == 0 && ie1[1] != ie2[1])
return ie2[1] - ie1[1];
return r;
}
static bool is_bss(struct cfg80211_bss *a,
const u8 *bssid,
const u8 *ssid, size_t ssid_len)
{
const u8 *ssidie;
if (bssid && compare_ether_addr(a->bssid, bssid))
return false;
if (!ssid)
return true;
ssidie = cfg80211_find_ie(WLAN_EID_SSID,
a->information_elements,
a->len_information_elements);
if (!ssidie)
return false;
if (ssidie[1] != ssid_len)
return false;
return memcmp(ssidie + 2, ssid, ssid_len) == 0;
}
static bool is_mesh(struct cfg80211_bss *a,
const u8 *meshid, size_t meshidlen,
const u8 *meshcfg)
{
const u8 *ie;
if (!is_zero_ether_addr(a->bssid))
return false;
ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
a->information_elements,
a->len_information_elements);
if (!ie)
return false;
if (ie[1] != meshidlen)
return false;
if (memcmp(ie + 2, meshid, meshidlen))
return false;
ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
a->information_elements,
a->len_information_elements);
if (!ie)
return false;
if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
return false;
/*
* Ignore mesh capability (last two bytes of the IE) when
* comparing since that may differ between stations taking
* part in the same mesh.
*/
return memcmp(ie + 2, meshcfg,
sizeof(struct ieee80211_meshconf_ie) - 2) == 0;
}
static int cmp_bss(struct cfg80211_bss *a,
struct cfg80211_bss *b)
{
int r;
if (a->channel != b->channel)
return b->channel->center_freq - a->channel->center_freq;
r = memcmp(a->bssid, b->bssid, ETH_ALEN);
if (r)
return r;
if (is_zero_ether_addr(a->bssid)) {
r = cmp_ies(WLAN_EID_MESH_ID,
a->information_elements,
a->len_information_elements,
b->information_elements,
b->len_information_elements);
if (r)
return r;
return cmp_ies(WLAN_EID_MESH_CONFIG,
a->information_elements,
a->len_information_elements,
b->information_elements,
b->len_information_elements);
}
return cmp_ies(WLAN_EID_SSID,
a->information_elements,
a->len_information_elements,
b->information_elements,
b->len_information_elements);
}
struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
struct ieee80211_channel *channel,
const u8 *bssid,
const u8 *ssid, size_t ssid_len,
u16 capa_mask, u16 capa_val)
{
struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
struct cfg80211_internal_bss *bss, *res = NULL;
unsigned long now = jiffies;
spin_lock_bh(&dev->bss_lock);
list_for_each_entry(bss, &dev->bss_list, list) {
if ((bss->pub.capability & capa_mask) != capa_val)
continue;
if (channel && bss->pub.channel != channel)
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;
kref_get(&res->ref);
break;
}
}
spin_unlock_bh(&dev->bss_lock);
if (!res)
return NULL;
return &res->pub;
}
EXPORT_SYMBOL(cfg80211_get_bss);
struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
struct ieee80211_channel *channel,
const u8 *meshid, size_t meshidlen,
const u8 *meshcfg)
{
struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
struct cfg80211_internal_bss *bss, *res = NULL;
spin_lock_bh(&dev->bss_lock);
list_for_each_entry(bss, &dev->bss_list, list) {
if (channel && bss->pub.channel != channel)
continue;
if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
res = bss;
kref_get(&res->ref);
break;
}
}
spin_unlock_bh(&dev->bss_lock);
if (!res)
return NULL;
return &res->pub;
}
EXPORT_SYMBOL(cfg80211_get_mesh);
static void rb_insert_bss(struct cfg80211_registered_device *dev,
struct cfg80211_internal_bss *bss)
{
struct rb_node **p = &dev->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);
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, &dev->bss_tree);
}
static struct cfg80211_internal_bss *
rb_find_bss(struct cfg80211_registered_device *dev,
struct cfg80211_internal_bss *res)
{
struct rb_node *n = dev->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);
if (r == 0)
return bss;
else if (r < 0)
n = n->rb_left;
else
n = n->rb_right;
}
return NULL;
}
static struct cfg80211_internal_bss *
cfg80211_bss_update(struct cfg80211_registered_device *dev,
struct cfg80211_internal_bss *res)
{
struct cfg80211_internal_bss *found = NULL;
const u8 *meshid, *meshcfg;
/*
* The reference to "res" is donated to this function.
*/
if (WARN_ON(!res->pub.channel)) {
kref_put(&res->ref, bss_release);
return NULL;
}
res->ts = jiffies;
if (is_zero_ether_addr(res->pub.bssid)) {
/* must be mesh, verify */
meshid = cfg80211_find_ie(WLAN_EID_MESH_ID,
res->pub.information_elements,
res->pub.len_information_elements);
meshcfg = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
res->pub.information_elements,
res->pub.len_information_elements);
if (!meshid || !meshcfg ||
meshcfg[1] != sizeof(struct ieee80211_meshconf_ie)) {
/* bogus mesh */
kref_put(&res->ref, bss_release);
return NULL;
}
}
spin_lock_bh(&dev->bss_lock);
found = rb_find_bss(dev, res);
if (found) {
found->pub.beacon_interval = res->pub.beacon_interval;
found->pub.tsf = res->pub.tsf;
found->pub.signal = res->pub.signal;
found->pub.capability = res->pub.capability;
found->ts = res->ts;
/* Update IEs */
if (res->pub.proberesp_ies) {
size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
size_t ielen = res->pub.len_proberesp_ies;
if (found->pub.proberesp_ies &&
!found->proberesp_ies_allocated &&
ksize(found) >= used + ielen) {
memcpy(found->pub.proberesp_ies,
res->pub.proberesp_ies, ielen);
found->pub.len_proberesp_ies = ielen;
} else {
u8 *ies = found->pub.proberesp_ies;
if (found->proberesp_ies_allocated)
ies = krealloc(ies, ielen, GFP_ATOMIC);
else
ies = kmalloc(ielen, GFP_ATOMIC);
if (ies) {
memcpy(ies, res->pub.proberesp_ies,
ielen);
found->proberesp_ies_allocated = true;
found->pub.proberesp_ies = ies;
found->pub.len_proberesp_ies = ielen;
}
}
/* Override possible earlier Beacon frame IEs */
found->pub.information_elements =
found->pub.proberesp_ies;
found->pub.len_information_elements =
found->pub.len_proberesp_ies;
}
if (res->pub.beacon_ies) {
size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
size_t ielen = res->pub.len_beacon_ies;
bool information_elements_is_beacon_ies =
(found->pub.information_elements ==
found->pub.beacon_ies);
if (found->pub.beacon_ies &&
!found->beacon_ies_allocated &&
ksize(found) >= used + ielen) {
memcpy(found->pub.beacon_ies,
res->pub.beacon_ies, ielen);
found->pub.len_beacon_ies = ielen;
} else {
u8 *ies = found->pub.beacon_ies;
if (found->beacon_ies_allocated)
ies = krealloc(ies, ielen, GFP_ATOMIC);
else
ies = kmalloc(ielen, GFP_ATOMIC);
if (ies) {
memcpy(ies, res->pub.beacon_ies,
ielen);
found->beacon_ies_allocated = true;
found->pub.beacon_ies = ies;
found->pub.len_beacon_ies = ielen;
}
}
/* Override IEs if they were from a beacon before */
if (information_elements_is_beacon_ies) {
found->pub.information_elements =
found->pub.beacon_ies;
found->pub.len_information_elements =
found->pub.len_beacon_ies;
}
}
kref_put(&res->ref, bss_release);
} else {
/* this "consumes" the reference */
list_add_tail(&res->list, &dev->bss_list);
rb_insert_bss(dev, res);
found = res;
}
dev->bss_generation++;
spin_unlock_bh(&dev->bss_lock);
kref_get(&found->ref);
return found;
}
struct cfg80211_bss*
cfg80211_inform_bss(struct wiphy *wiphy,
struct ieee80211_channel *channel,
const u8 *bssid,
u64 timestamp, u16 capability, u16 beacon_interval,
const u8 *ie, size_t ielen,
s32 signal, gfp_t gfp)
{
struct cfg80211_internal_bss *res;
size_t privsz;
if (WARN_ON(!wiphy))
return NULL;
privsz = wiphy->bss_priv_size;
if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
(signal < 0 || signal > 100)))
return NULL;
res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
if (!res)
return NULL;
memcpy(res->pub.bssid, bssid, ETH_ALEN);
res->pub.channel = channel;
res->pub.signal = signal;
res->pub.tsf = timestamp;
res->pub.beacon_interval = beacon_interval;
res->pub.capability = capability;
/*
* Since 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 information_elements pointer should we have received an
* earlier indication of Probe Response data.
*
* The initial buffer for the IEs is allocated with the BSS entry and
* is located after the private area.
*/
res->pub.beacon_ies = (u8 *)res + sizeof(*res) + privsz;
memcpy(res->pub.beacon_ies, ie, ielen);
res->pub.len_beacon_ies = ielen;
res->pub.information_elements = res->pub.beacon_ies;
res->pub.len_information_elements = res->pub.len_beacon_ies;
kref_init(&res->ref);
res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
if (!res)
return NULL;
if (res->pub.capability & WLAN_CAPABILITY_ESS)
regulatory_hint_found_beacon(wiphy, channel, gfp);
/* cfg80211_bss_update gives us a referenced result */
return &res->pub;
}
EXPORT_SYMBOL(cfg80211_inform_bss);
struct cfg80211_bss *
cfg80211_inform_bss_frame(struct wiphy *wiphy,
struct ieee80211_channel *channel,
struct ieee80211_mgmt *mgmt, size_t len,
s32 signal, gfp_t gfp)
{
struct cfg80211_internal_bss *res;
size_t ielen = len - offsetof(struct ieee80211_mgmt,
u.probe_resp.variable);
size_t privsz;
if (WARN_ON(!mgmt))
return NULL;
if (WARN_ON(!wiphy))
return NULL;
if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
(signal < 0 || signal > 100)))
return NULL;
if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
return NULL;
privsz = wiphy->bss_priv_size;
res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
if (!res)
return NULL;
memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
res->pub.channel = channel;
res->pub.signal = signal;
res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
/*
* The initial buffer for the IEs is allocated with the BSS entry and
* is located after the private area.
*/
if (ieee80211_is_probe_resp(mgmt->frame_control)) {
res->pub.proberesp_ies = (u8 *) res + sizeof(*res) + privsz;
memcpy(res->pub.proberesp_ies, mgmt->u.probe_resp.variable,
ielen);
res->pub.len_proberesp_ies = ielen;
res->pub.information_elements = res->pub.proberesp_ies;
res->pub.len_information_elements = res->pub.len_proberesp_ies;
} else {
res->pub.beacon_ies = (u8 *) res + sizeof(*res) + privsz;
memcpy(res->pub.beacon_ies, mgmt->u.beacon.variable, ielen);
res->pub.len_beacon_ies = ielen;
res->pub.information_elements = res->pub.beacon_ies;
res->pub.len_information_elements = res->pub.len_beacon_ies;
}
kref_init(&res->ref);
res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
if (!res)
return NULL;
if (res->pub.capability & WLAN_CAPABILITY_ESS)
regulatory_hint_found_beacon(wiphy, channel, gfp);
/* cfg80211_bss_update gives us a referenced result */
return &res->pub;
}
EXPORT_SYMBOL(cfg80211_inform_bss_frame);
void cfg80211_put_bss(struct cfg80211_bss *pub)
{
struct cfg80211_internal_bss *bss;
if (!pub)
return;
bss = container_of(pub, struct cfg80211_internal_bss, pub);
kref_put(&bss->ref, bss_release);
}
EXPORT_SYMBOL(cfg80211_put_bss);
void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
{
struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
struct cfg80211_internal_bss *bss;
if (WARN_ON(!pub))
return;
bss = container_of(pub, struct cfg80211_internal_bss, pub);
spin_lock_bh(&dev->bss_lock);
if (!list_empty(&bss->list)) {
__cfg80211_unlink_bss(dev, bss);
dev->bss_generation++;
}
spin_unlock_bh(&dev->bss_lock);
}
EXPORT_SYMBOL(cfg80211_unlink_bss);
#ifdef CONFIG_CFG80211_WEXT
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 ieee80211_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) {
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 {
for (band = 0; band < IEEE80211_NUM_BANDS; band++)
if (wiphy->bands[band])
n_channels += wiphy->bands[band]->n_channels;
}
creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
n_channels * sizeof(void *),
GFP_ATOMIC);
if (!creq) {
err = -ENOMEM;
goto out;
}
creq->wiphy = wiphy;
creq->dev = dev;
/* SSIDs come after channels */
creq->ssids = (void *)&creq->channels[n_channels];
creq->n_channels = n_channels;
creq->n_ssids = 1;
/* translate "Scan on frequencies" request */
i = 0;
for (band = 0; band < IEEE80211_NUM_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++) {
int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
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;
}
rdev->scan_req = creq;
err = rdev->ops->scan(wiphy, dev, creq);
if (err) {
rdev->scan_req = NULL;
/* creq will be freed below */
} else {
nl80211_send_scan_start(rdev, dev);
/* creq now owned by driver */
creq = NULL;
dev_hold(dev);
}
out:
kfree(creq);
cfg80211_unlock_rdev(rdev);
return err;
}
EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
static void ieee80211_scan_add_ies(struct iw_request_info *info,
struct cfg80211_bss *bss,
char **current_ev, char *end_buf)
{
u8 *pos, *end, *next;
struct iw_event iwe;
if (!bss->information_elements ||
!bss->len_information_elements)
return;
/*
* If needed, fragment the IEs buffer (at IE boundaries) into short
* enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
*/
pos = bss->information_elements;
end = pos + bss->len_information_elements;
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(info, *current_ev,
end_buf, &iwe, pos);
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(info, *current_ev,
end_buf, &iwe, pos);
}
}
static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
{
unsigned long end = jiffies;
if (end >= start)
return jiffies_to_msecs(end - start);
return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
}
static char *
ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
struct cfg80211_internal_bss *bss, char *current_ev,
char *end_buf)
{
struct iw_event iwe;
u8 *buf, *cfg, *p;
u8 *ie = bss->pub.information_elements;
int rem = bss->pub.len_information_elements, 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(info, current_ev, end_buf, &iwe,
IW_EV_ADDR_LEN);
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(info, current_ev, end_buf, &iwe,
IW_EV_FREQ_LEN);
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(info, current_ev, end_buf, &iwe,
IW_EV_FREQ_LEN);
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(info, current_ev, end_buf,
&iwe, IW_EV_QUAL_LEN);
}
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(info, current_ev, end_buf,
&iwe, "");
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(info, current_ev, end_buf,
&iwe, ie + 2);
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(info, current_ev, end_buf,
&iwe, ie + 2);
break;
case WLAN_EID_MESH_CONFIG:
ismesh = true;
if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
break;
buf = kmalloc(50, GFP_ATOMIC);
if (!buf)
break;
cfg = 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(info, current_ev,
end_buf,
&iwe, buf);
sprintf(buf, "Path Selection Metric ID: 0x%02X",
cfg[1]);
iwe.u.data.length = strlen(buf);
current_ev = iwe_stream_add_point(info, current_ev,
end_buf,
&iwe, buf);
sprintf(buf, "Congestion Control Mode ID: 0x%02X",
cfg[2]);
iwe.u.data.length = strlen(buf);
current_ev = iwe_stream_add_point(info, current_ev,
end_buf,
&iwe, buf);
sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
iwe.u.data.length = strlen(buf);
current_ev = iwe_stream_add_point(info, current_ev,
end_buf,
&iwe, buf);
sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
iwe.u.data.length = strlen(buf);
current_ev = iwe_stream_add_point(info, current_ev,
end_buf,
&iwe, buf);
sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
iwe.u.data.length = strlen(buf);
current_ev = iwe_stream_add_point(info, current_ev,
end_buf,
&iwe, buf);
sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
iwe.u.data.length = strlen(buf);
current_ev = iwe_stream_add_point(info, current_ev,
end_buf,
&iwe, buf);
kfree(buf);
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);
p = iwe_stream_add_value(info, current_ev, p,
end_buf, &iwe, IW_EV_PARAM_LEN);
}
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(info, current_ev, end_buf,
&iwe, IW_EV_UINT_LEN);
}
buf = kmalloc(30, GFP_ATOMIC);
if (buf) {
memset(&iwe, 0, sizeof(iwe));
iwe.cmd = IWEVCUSTOM;
sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
iwe.u.data.length = strlen(buf);
current_ev = iwe_stream_add_point(info, current_ev, end_buf,
&iwe, buf);
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(info, current_ev,
end_buf, &iwe, buf);
kfree(buf);
}
ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
return current_ev;
}
static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
struct iw_request_info *info,
char *buf, size_t len)
{
char *current_ev = buf;
char *end_buf = buf + len;
struct cfg80211_internal_bss *bss;
spin_lock_bh(&dev->bss_lock);
cfg80211_bss_expire(dev);
list_for_each_entry(bss, &dev->bss_list, list) {
if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
spin_unlock_bh(&dev->bss_lock);
return -E2BIG;
}
current_ev = ieee80211_bss(&dev->wiphy, info, bss,
current_ev, end_buf);
}
spin_unlock_bh(&dev->bss_lock);
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) {
res = -EAGAIN;
goto out;
}
res = ieee80211_scan_results(rdev, info, extra, data->length);
data->length = 0;
if (res >= 0) {
data->length = res;
res = 0;
}
out:
cfg80211_unlock_rdev(rdev);
return res;
}
EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
#endif