2010-01-26 13:15:48

by Johannes Berg

[permalink] [raw]
Subject: [PATCH] cfg80211: export cfg80211_find_ie

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 <[email protected]>
---
include/net/cfg80211.h | 16 ++++++++++++++++
net/wireless/scan.c | 38 ++++++++++++++++++++------------------
2 files changed, 36 insertions(+), 18 deletions(-)

--- wireless-testing.orig/include/net/cfg80211.h 2010-01-26 08:40:45.000000000 +0100
+++ wireless-testing/include/net/cfg80211.h 2010-01-26 08:46:44.000000000 +0100
@@ -1669,6 +1669,22 @@ void ieee80211_amsdu_to_8023s(struct sk_
*/
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
*/
--- wireless-testing.orig/net/wireless/scan.c 2010-01-26 08:40:45.000000000 +0100
+++ wireless-testing/net/wireless/scan.c 2010-01-26 08:41:00.000000000 +0100
@@ -143,9 +143,9 @@ void cfg80211_bss_expire(struct cfg80211
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
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 *
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
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
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_regi

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 */




2010-01-26 13:22:04

by Holger Schurig

[permalink] [raw]
Subject: Re: [PATCH] cfg80211: export cfg80211_find_ie

AFAIK I wrote something similar for cfg80211-libertas, so this is handy.

--
http://www.holgerschurig.de