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authorJohannes Berg <johannes.berg@intel.com>2019-02-07 23:44:41 +0300
committerJohannes Berg <johannes.berg@intel.com>2019-02-08 15:51:46 +0300
commit0f3b07f027f87a38ebe5c436490095df762819be (patch)
treede50f59459836721da01ed32f43a678736275800 /net/wireless/scan.c
parent341203e78943236d4a8e4ca58d6a236195f0652e (diff)
downloadlinux-0f3b07f027f87a38ebe5c436490095df762819be.tar.xz
cfg80211: add and use strongly typed element iteration macros
Rather than always iterating elements from frames with pure u8 pointers, add a type "struct element" that encapsulates the id/datalen/data format of them. Then, add the element iteration macros * for_each_element * for_each_element_id * for_each_element_extid which take, as their first 'argument', such a structure and iterate through a given u8 array interpreting it as elements. While at it and since we'll need it, also add * for_each_subelement * for_each_subelement_id * for_each_subelement_extid which instead of taking data/length just take an outer element and use its data/datalen. Also add for_each_element_completed() to determine if any of the loops above completed, i.e. it was able to parse all of the elements successfully and no data remained. Use for_each_element_id() in cfg80211_find_ie_match() as the first user of this. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/wireless/scan.c')
-rw-r--r--net/wireless/scan.c14
1 files changed, 6 insertions, 8 deletions
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 5123667f4569..c7f64bb9c581 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -484,6 +484,8 @@ const u8 *cfg80211_find_ie_match(u8 eid, const u8 *ies, int len,
const u8 *match, int match_len,
int match_offset)
{
+ const struct element *elem;
+
/* match_offset can't be smaller than 2, unless match_len is
* zero, in which case match_offset must be zero as well.
*/
@@ -491,14 +493,10 @@ const u8 *cfg80211_find_ie_match(u8 eid, const u8 *ies, int len,
(!match_len && match_offset)))
return NULL;
- while (len >= 2 && len >= ies[1] + 2) {
- if ((ies[0] == eid) &&
- (ies[1] + 2 >= match_offset + match_len) &&
- !memcmp(ies + match_offset, match, match_len))
- return ies;
-
- len -= ies[1] + 2;
- ies += ies[1] + 2;
+ for_each_element_id(elem, eid, ies, len) {
+ if (elem->datalen >= match_offset - 2 + match_len &&
+ !memcmp(elem->data + match_offset - 2, match, match_len))
+ return (void *)elem;
}
return NULL;