From: Johannes Berg <johannes.berg@xxxxxxxxx>
Instead of duplicating the rbtree functions, pass
an argument to the compare function. This removes
the code duplication for the two searches.
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
---
net/wireless/scan.c | 79 ++++++++++++-----------------------------------------
1 file changed, 17 insertions(+), 62 deletions(-)
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index ca367c5..72ef3b2 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -425,34 +425,13 @@ static int cmp_bss_core(struct cfg80211_bss *a, struct cfg80211_bss *b)
}
static int cmp_bss(struct cfg80211_bss *a,
- struct cfg80211_bss *b)
-{
- const struct cfg80211_bss_ies *a_ies, *b_ies;
- int r;
-
- r = cmp_bss_core(a, b);
- if (r)
- return r;
-
- a_ies = rcu_access_pointer(a->ies);
- if (!a_ies)
- return -1;
- b_ies = rcu_access_pointer(b->ies);
- if (!b_ies)
- return 1;
-
- return cmp_ies(WLAN_EID_SSID,
- a_ies->data, a_ies->len,
- b_ies->data, b_ies->len);
-}
-
-static int cmp_hidden_bss(struct cfg80211_bss *a, struct cfg80211_bss *b)
+ struct cfg80211_bss *b,
+ bool hide_ssid)
{
const struct cfg80211_bss_ies *a_ies, *b_ies;
const u8 *ie1;
const u8 *ie2;
- int i;
- int r;
+ int i, r;
r = cmp_bss_core(a, b);
if (r)
@@ -469,14 +448,9 @@ static int cmp_hidden_bss(struct cfg80211_bss *a, struct cfg80211_bss *b)
ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
/*
- * 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.
- *
- * Note that due to the differring behaviour with hidden SSIDs
- * this function only works when "b" is the tree element and
- * "a" is the key we're looking for.
+ * 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 */
@@ -485,14 +459,17 @@ static int cmp_hidden_bss(struct cfg80211_bss *a, struct cfg80211_bss *b)
if (!ie2)
return 1;
- /* zero-size SSID is used as an indication of the hidden bss */
- if (!ie2[1])
+ /* zero-length SSID is used as an indication of the hidden bss */
+ if (hide_ssid && !ie2[1])
return 0;
/* sort by length first, then by contents */
if (ie1[1] != ie2[1])
return ie2[1] - ie1[1];
+ if (!hide_ssid)
+ return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
+
/*
* zeroed SSID ie is another indication of a hidden bss;
* if it isn't zeroed just return the regular sort value
@@ -584,7 +561,7 @@ static void rb_insert_bss(struct cfg80211_registered_device *dev,
parent = *p;
tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
- cmp = cmp_bss(&bss->pub, &tbss->pub);
+ cmp = cmp_bss(&bss->pub, &tbss->pub, false);
if (WARN_ON(!cmp)) {
/* will sort of leak this BSS */
@@ -603,30 +580,8 @@ static void rb_insert_bss(struct cfg80211_registered_device *dev,
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 *
-rb_find_hidden_bss(struct cfg80211_registered_device *dev,
- struct cfg80211_internal_bss *res)
+ struct cfg80211_internal_bss *res,
+ bool hidden)
{
struct rb_node *n = dev->bss_tree.rb_node;
struct cfg80211_internal_bss *bss;
@@ -634,7 +589,7 @@ 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(&res->pub, &bss->pub, hidden);
if (r == 0)
return bss;
@@ -684,7 +639,7 @@ cfg80211_bss_update(struct cfg80211_registered_device *dev,
return NULL;
}
- found = rb_find_bss(dev, tmp);
+ found = rb_find_bss(dev, tmp, false);
if (found) {
found->pub.beacon_interval = tmp->pub.beacon_interval;
@@ -739,7 +694,7 @@ cfg80211_bss_update(struct cfg80211_registered_device *dev,
/* 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, tmp);
+ hidden = rb_find_bss(dev, tmp, true);
if (hidden)
copy_hidden_ies(tmp, hidden);
--
1.8.0
--
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