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authorJohn W. Linville <linville@tuxdriver.com>2011-11-17 13:11:43 -0500
committerJohn W. Linville <linville@tuxdriver.com>2011-11-17 13:11:43 -0500
commite11c259f745889b55bc5596ca78271f2f5cf08d2 (patch)
tree5025f0bf9093e84d0643beb9097249c176dbbea7 /net/wireless/scan.c
parent8d26784cf0d04c1238e906efdd5de76439cb0a1e (diff)
parentb4487c2d0edaf1332d7a9f11b5661044955ef5e2 (diff)
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next into for-davem
Conflicts: include/net/bluetooth/bluetooth.h
Diffstat (limited to 'net/wireless/scan.c')
-rw-r--r--net/wireless/scan.c130
1 files changed, 122 insertions, 8 deletions
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 0fb14241040..31119e32e09 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -259,17 +259,20 @@ 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;
+ /* equal if both missing */
if (!ie1 && !ie2)
return 0;
- if (!ie1 || !ie2)
+ /* sort missing IE before (left of) present IE */
+ if (!ie1)
return -1;
+ if (!ie2)
+ return 1;
- r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
- if (r == 0 && ie1[1] != ie2[1])
+ /* sort by length first, then by contents */
+ if (ie1[1] != ie2[1])
return ie2[1] - ie1[1];
- return r;
+ return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
}
static bool is_bss(struct cfg80211_bss *a,
@@ -352,8 +355,8 @@ static bool is_mesh(struct cfg80211_bss *a,
sizeof(struct ieee80211_meshconf_ie) - 2) == 0;
}
-static int cmp_bss(struct cfg80211_bss *a,
- struct cfg80211_bss *b)
+static int cmp_bss_core(struct cfg80211_bss *a,
+ struct cfg80211_bss *b)
{
int r;
@@ -375,7 +378,15 @@ static int cmp_bss(struct cfg80211_bss *a,
b->len_information_elements);
}
- r = memcmp(a->bssid, b->bssid, ETH_ALEN);
+ return memcmp(a->bssid, b->bssid, ETH_ALEN);
+}
+
+static int cmp_bss(struct cfg80211_bss *a,
+ struct cfg80211_bss *b)
+{
+ int r;
+
+ r = cmp_bss_core(a, b);
if (r)
return r;
@@ -386,6 +397,52 @@ 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,
@@ -502,6 +559,48 @@ rb_find_bss(struct cfg80211_registered_device *dev,
}
static struct cfg80211_internal_bss *
+rb_find_hidden_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_hidden_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 void
+copy_hidden_ies(struct cfg80211_internal_bss *res,
+ struct cfg80211_internal_bss *hidden)
+{
+ if (unlikely(res->pub.beacon_ies))
+ return;
+ if (WARN_ON(!hidden->pub.beacon_ies))
+ return;
+
+ res->pub.beacon_ies = kmalloc(hidden->pub.len_beacon_ies, GFP_ATOMIC);
+ if (unlikely(!res->pub.beacon_ies))
+ return;
+
+ 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 struct cfg80211_internal_bss *
cfg80211_bss_update(struct cfg80211_registered_device *dev,
struct cfg80211_internal_bss *res)
{
@@ -604,6 +703,21 @@ cfg80211_bss_update(struct cfg80211_registered_device *dev,
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);
+
/* this "consumes" the reference */
list_add_tail(&res->list, &dev->bss_list);
rb_insert_bss(dev, res);