cfg80211: export cfg80211_find_ie
Johannes Berg [Tue, 26 Jan 2010 13:15:46 +0000 (14:15 +0100)]
This new function (previously a static function
called just "find_ie" can be used to find a
specific IE in a buffer of IEs.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

include/net/cfg80211.h
net/wireless/scan.c

index c5d16f2..a3f0a7e 100644 (file)
@@ -1658,6 +1658,22 @@ void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list,
  */
 unsigned int cfg80211_classify8021d(struct sk_buff *skb);
 
+/**
+ * cfg80211_find_ie - find information element in data
+ *
+ * @eid: element ID
+ * @ies: data consisting of IEs
+ * @len: length of data
+ *
+ * This function will return %NULL if the element ID could
+ * not be found or if the element is invalid (claims to be
+ * longer than the given data), or a pointer to the first byte
+ * of the requested element, that is the byte containing the
+ * element ID. There are no checks on the element length
+ * other than having to fit into the given data.
+ */
+const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len);
+
 /*
  * Regulatory helper functions for wiphys
  */
index 06b0231..978cac3 100644 (file)
@@ -143,9 +143,9 @@ void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
                dev->bss_generation++;
 }
 
-static u8 *find_ie(u8 num, u8 *ies, int len)
+const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
 {
-       while (len > 2 && ies[0] != num) {
+       while (len > 2 && ies[0] != eid) {
                len -= ies[1] + 2;
                ies += ies[1] + 2;
        }
@@ -155,11 +155,12 @@ static u8 *find_ie(u8 num, u8 *ies, int len)
                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 = find_ie(num, ies1, len1);
-       const u8 *ie2 = find_ie(num, ies2, len2);
+       const u8 *ie1 = cfg80211_find_ie(num, ies1, len1);
+       const u8 *ie2 = cfg80211_find_ie(num, ies2, len2);
        int r;
 
        if (!ie1 && !ie2)
@@ -185,9 +186,9 @@ static bool is_bss(struct cfg80211_bss *a,
        if (!ssid)
                return true;
 
-       ssidie = find_ie(WLAN_EID_SSID,
-                        a->information_elements,
-                        a->len_information_elements);
+       ssidie = cfg80211_find_ie(WLAN_EID_SSID,
+                                 a->information_elements,
+                                 a->len_information_elements);
        if (!ssidie)
                return false;
        if (ssidie[1] != ssid_len)
@@ -204,9 +205,9 @@ static bool is_mesh(struct cfg80211_bss *a,
        if (!is_zero_ether_addr(a->bssid))
                return false;
 
-       ie = find_ie(WLAN_EID_MESH_ID,
-                    a->information_elements,
-                    a->len_information_elements);
+       ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
+                             a->information_elements,
+                             a->len_information_elements);
        if (!ie)
                return false;
        if (ie[1] != meshidlen)
@@ -214,9 +215,9 @@ static bool is_mesh(struct cfg80211_bss *a,
        if (memcmp(ie + 2, meshid, meshidlen))
                return false;
 
-       ie = find_ie(WLAN_EID_MESH_CONFIG,
-                    a->information_elements,
-                    a->len_information_elements);
+       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))
@@ -395,11 +396,12 @@ cfg80211_bss_update(struct cfg80211_registered_device *dev,
 
        if (is_zero_ether_addr(res->pub.bssid)) {
                /* must be mesh, verify */
-               meshid = find_ie(WLAN_EID_MESH_ID, res->pub.information_elements,
-                                res->pub.len_information_elements);
-               meshcfg = find_ie(WLAN_EID_MESH_CONFIG,
-                                 res->pub.information_elements,
-                                 res->pub.len_information_elements);
+               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 */