More correct implementation of the same idea as in the
"cfg80211: merge in beacon ies of hidden bss" commit.
The patch implements linked list of aliases for bss (alias is a bss
with the same key information but with different ESSID).
Ie update rules when new beacon/proberesp is coming:
- Beacon updates target bss and aliases with empty beacon ies list.
- Probe response ies updates only target bss structure.
- Beacon ies of incoming probe response are filled with
beacon ies taken from an alias.
Signed-off-by: Dmitry Tarnyagin <dmitry.tarnyagin@xxxxxxxxxxxxxx>
---
net/wireless/core.h | 1 +
net/wireless/scan.c | 287 ++++++++++++++++++++++----------------------------
2 files changed, 127 insertions(+), 161 deletions(-)
diff --git a/net/wireless/core.h b/net/wireless/core.h
index 1c7d4df..9a08dcb 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -128,6 +128,7 @@ static inline void assert_cfg80211_lock(void)
struct cfg80211_internal_bss {
struct list_head list;
+ struct list_head list_aliases;
struct rb_node rbn;
unsigned long ts;
struct kref ref;
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 31119e3..bca8602 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -191,6 +191,8 @@ static void __cfg80211_unlink_bss(struct
cfg80211_registered_device *dev,
struct cfg80211_internal_bss *bss)
{
list_del_init(&bss->list);
+ if (!list_empty(&bss->list_aliases))
+ list_del_init(&bss->list_aliases);
rb_erase(&bss->rbn, &dev->bss_tree);
kref_put(&bss->ref, bss_release);
}
@@ -355,8 +357,8 @@ static bool is_mesh(struct cfg80211_bss *a,
sizeof(struct ieee80211_meshconf_ie) - 2) == 0;
}
-static int cmp_bss_core(struct cfg80211_bss *a,
- struct cfg80211_bss *b)
+static int cmp_bss_noessid(struct cfg80211_bss *a,
+ struct cfg80211_bss *b)
{
int r;
@@ -386,7 +388,7 @@ static int cmp_bss(struct cfg80211_bss *a,
{
int r;
- r = cmp_bss_core(a, b);
+ r = cmp_bss_noessid(a, b);
if (r)
return r;
@@ -397,52 +399,6 @@ static int cmp_bss(struct cfg80211_bss *a,
b->len_information_elements);
}
-static int cmp_hidden_bss(struct cfg80211_bss *a,
- struct cfg80211_bss *b)
-{
- const u8 *ie1;
- const u8 *ie2;
- int i;
- int r;
-
- r = cmp_bss_core(a, b);
- if (r)
- return r;
-
- ie1 = cfg80211_find_ie(WLAN_EID_SSID,
- a->information_elements,
- a->len_information_elements);
- ie2 = cfg80211_find_ie(WLAN_EID_SSID,
- b->information_elements,
- b->len_information_elements);
-
- /* Key comparator must use same algorithm in any rb-tree
- * search function (order is important), otherwise ordering
- * of items in the tree is broken and search gives incorrect
- * results. This code uses same order as cmp_ies() does. */
-
- /* sort missing IE before (left of) present IE */
- if (!ie1)
- return -1;
- if (!ie2)
- return 1;
-
- /* zero-size SSID is used as an indication of the hidden bss */
- if (!ie2[1])
- return 0;
-
- /* sort by length first, then by contents */
- if (ie1[1] != ie2[1])
- return ie2[1] - ie1[1];
-
- /* zeroed SSID ie is another indication of a hidden bss */
- for (i = 0; i < ie2[1]; i++)
- if (ie2[i + 2])
- return -1;
-
- return 0;
-}
-
struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
struct ieee80211_channel *channel,
const u8 *bssid,
@@ -559,7 +515,7 @@ rb_find_bss(struct cfg80211_registered_device *dev,
}
static struct cfg80211_internal_bss *
-rb_find_hidden_bss(struct cfg80211_registered_device *dev,
+rb_find_bss_alias(struct cfg80211_registered_device *dev,
struct cfg80211_internal_bss *res)
{
struct rb_node *n = dev->bss_tree.rb_node;
@@ -568,7 +524,7 @@ rb_find_hidden_bss(struct cfg80211_registered_device *dev,
while (n) {
bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
- r = cmp_hidden_bss(&res->pub, &bss->pub);
+ r = cmp_bss_noessid(&res->pub, &bss->pub);
if (r == 0)
return bss;
@@ -582,29 +538,120 @@ rb_find_hidden_bss(struct
cfg80211_registered_device *dev,
}
static void
-copy_hidden_ies(struct cfg80211_internal_bss *res,
- struct cfg80211_internal_bss *hidden)
+cfg80211_bss_update_bss(struct cfg80211_registered_device *dev,
+ struct cfg80211_internal_bss *prev,
+ struct cfg80211_internal_bss *res,
+ int force)
{
- if (unlikely(res->pub.beacon_ies))
- return;
- if (WARN_ON(!hidden->pub.beacon_ies))
- return;
+ prev->pub.beacon_interval = res->pub.beacon_interval;
+ prev->pub.tsf = res->pub.tsf;
+ prev->pub.signal = res->pub.signal;
+ prev->pub.capability = res->pub.capability;
+ prev->ts = res->ts;
+
+ /* Update IEs */
+ if (res->pub.proberesp_ies && (force || !prev->pub.proberesp_ies)) {
+ size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
+ size_t ielen = res->pub.len_proberesp_ies;
+
+ if (prev->pub.proberesp_ies &&
+ !prev->proberesp_ies_allocated &&
+ ksize(prev) >= used + ielen) {
+ memcpy(prev->pub.proberesp_ies,
+ res->pub.proberesp_ies, ielen);
+ prev->pub.len_proberesp_ies = ielen;
+ } else {
+ u8 *ies = prev->pub.proberesp_ies;
+
+ if (prev->proberesp_ies_allocated)
+ ies = krealloc(ies, ielen, GFP_ATOMIC);
+ else
+ ies = kmalloc(ielen, GFP_ATOMIC);
+
+ if (ies) {
+ memcpy(ies, res->pub.proberesp_ies,
+ ielen);
+ prev->proberesp_ies_allocated = true;
+ prev->pub.proberesp_ies = ies;
+ prev->pub.len_proberesp_ies = ielen;
+ }
+ }
- res->pub.beacon_ies = kmalloc(hidden->pub.len_beacon_ies, GFP_ATOMIC);
- if (unlikely(!res->pub.beacon_ies))
- return;
+ /* Override possible earlier Beacon frame IEs */
+ prev->pub.information_elements =
+ prev->pub.proberesp_ies;
+ prev->pub.len_information_elements =
+ prev->pub.len_proberesp_ies;
+ }
+ if (res->pub.beacon_ies && (force || !prev->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 =
+ (prev->pub.information_elements ==
+ prev->pub.beacon_ies);
+
+ if (prev->pub.beacon_ies &&
+ !prev->beacon_ies_allocated &&
+ ksize(prev) >= used + ielen) {
+ memcpy(prev->pub.beacon_ies,
+ res->pub.beacon_ies, ielen);
+ prev->pub.len_beacon_ies = ielen;
+ } else {
+ u8 *ies = prev->pub.beacon_ies;
+
+ if (prev->beacon_ies_allocated)
+ ies = krealloc(ies, ielen, GFP_ATOMIC);
+ else
+ ies = kmalloc(ielen, GFP_ATOMIC);
+
+ if (ies) {
+ memcpy(ies, res->pub.beacon_ies,
+ ielen);
+ prev->beacon_ies_allocated = true;
+ prev->pub.beacon_ies = ies;
+ prev->pub.len_beacon_ies = ielen;
+ }
+ }
+
+ /* Override IEs if they were from a beacon before */
+ if (information_elements_is_beacon_ies) {
+ prev->pub.information_elements =
+ prev->pub.beacon_ies;
+ prev->pub.len_information_elements =
+ prev->pub.len_beacon_ies;
+ }
+ }
+}
- res->beacon_ies_allocated = true;
- res->pub.len_beacon_ies = hidden->pub.len_beacon_ies;
- memcpy(res->pub.beacon_ies, hidden->pub.beacon_ies,
- res->pub.len_beacon_ies);
+static void
+cfg80211_bss_update_list(struct cfg80211_registered_device *dev,
+ struct cfg80211_internal_bss *prev,
+ struct cfg80211_internal_bss *res,
+ int force)
+{
+ struct cfg80211_internal_bss *bss;
+
+ cfg80211_bss_update_bss(dev, prev, res, force);
+ list_for_each_entry(bss, &prev->list_aliases, list_aliases)
+ cfg80211_bss_update_bss(dev, bss, res, force);
+}
+
+static void
+cfg80211_bss_insert(struct cfg80211_registered_device *dev,
+ struct cfg80211_internal_bss *alias,
+ struct cfg80211_internal_bss *res)
+{
+ list_add_tail(&res->list, &dev->bss_list);
+ if (alias)
+ list_add_tail(&alias->list_aliases, &res->list_aliases);
+ rb_insert_bss(dev, res);
}
static struct cfg80211_internal_bss *
cfg80211_bss_update(struct cfg80211_registered_device *dev,
struct cfg80211_internal_bss *res)
{
- struct cfg80211_internal_bss *found = NULL;
+ struct cfg80211_internal_bss *found = NULL, *alias;
/*
* The reference to "res" is donated to this function.
@@ -622,105 +669,21 @@ cfg80211_bss_update(struct
cfg80211_registered_device *dev,
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;
- }
- }
-
+ if (res->pub.beacon_ies)
+ cfg80211_bss_update_list(dev, found, res, 1);
+ else
+ cfg80211_bss_update_bss(dev, found, res, 1);
kref_put(&res->ref, bss_release);
} else {
- struct cfg80211_internal_bss *hidden;
-
- /* First check if the beacon is a probe response from
- * a hidden bss. If so, copy beacon ies (with nullified
- * ssid) into the probe response bss entry (with real ssid).
- * It is required basically for PSM implementation
- * (probe responses do not contain tim ie) */
-
- /* TODO: The code is not trying to update existing probe
- * response bss entries when beacon ies are
- * getting changed. */
- hidden = rb_find_hidden_bss(dev, res);
- if (hidden)
- copy_hidden_ies(res, hidden);
-
+ alias = rb_find_bss_alias(dev, res);
+ if (alias) {
+ if (res->pub.beacon_ies)
+ cfg80211_bss_update_list(dev, alias, res, 0);
+ else
+ cfg80211_bss_update_bss(dev, res, alias, 0);
+ }
/* this "consumes" the reference */
- list_add_tail(&res->list, &dev->bss_list);
- rb_insert_bss(dev, res);
+ cfg80211_bss_insert(dev, alias, res);
found = res;
}
@@ -761,6 +724,7 @@ cfg80211_inform_bss(struct wiphy *wiphy,
res->pub.tsf = timestamp;
res->pub.beacon_interval = beacon_interval;
res->pub.capability = capability;
+ INIT_LIST_HEAD(&res->list_aliases);
/*
* 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
@@ -828,6 +792,7 @@ cfg80211_inform_bss_frame(struct wiphy *wiphy,
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);
+ INIT_LIST_HEAD(&res->list_aliases);
/*
* The initial buffer for the IEs is allocated with the BSS entry and
* is located after the private area.
--
With best regards,
Dmitry Tarnyagin
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