diff options
author | Johannes Berg <johannes.berg@intel.com> | 2019-02-07 23:44:41 +0300 |
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committer | Johannes Berg <johannes.berg@intel.com> | 2019-02-08 15:51:46 +0300 |
commit | 0f3b07f027f87a38ebe5c436490095df762819be (patch) | |
tree | de50f59459836721da01ed32f43a678736275800 /net/wireless/scan.c | |
parent | 341203e78943236d4a8e4ca58d6a236195f0652e (diff) | |
download | linux-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.c | 14 |
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; |