cfg80211: add and use strongly typed element iteration macros

[GitHub/LineageOS/android_kernel_motorola_exynos9610.git] / include / linux / ieee80211.h

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 55a604ad459f6e105ac3856f3b298b053365277c..cf41820f279493ae215b36c8cccbabc6768b04d0 100644 (file)
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -2743,4 +2743,57 @@ static inline bool ieee80211_action_contains_tpc(struct sk_buff *skb)
        return true;
 }
 
+struct element {
+       u8 id;
+       u8 datalen;
+       u8 data[];
+};
+
+/* element iteration helpers */
+#define for_each_element(element, _data, _datalen)                     \
+       for (element = (void *)(_data);                                 \
+            (u8 *)(_data) + (_datalen) - (u8 *)element >=              \
+               sizeof(*element) &&                                     \
+            (u8 *)(_data) + (_datalen) - (u8 *)element >=              \
+               sizeof(*element) + element->datalen;                    \
+            element = (void *)(element->data + element->datalen))
+
+#define for_each_element_id(element, _id, data, datalen)               \
+       for_each_element(element, data, datalen)                        \
+               if (element->id == (_id))
+
+#define for_each_element_extid(element, extid, data, datalen)          \
+       for_each_element(element, data, datalen)                        \
+               if (element->id == WLAN_EID_EXTENSION &&                \
+                   element->datalen > 0 &&                             \
+                   element->data[0] == (extid))
+
+#define for_each_subelement(sub, element)                              \
+       for_each_element(sub, (element)->data, (element)->datalen)
+
+#define for_each_subelement_id(sub, id, element)                       \
+       for_each_element_id(sub, id, (element)->data, (element)->datalen)
+
+#define for_each_subelement_extid(sub, extid, element)                 \
+       for_each_element_extid(sub, extid, (element)->data, (element)->datalen)
+
+/**
+ * for_each_element_completed - determine if element parsing consumed all data
+ * @element: element pointer after for_each_element() or friends
+ * @data: same data pointer as passed to for_each_element() or friends
+ * @datalen: same data length as passed to for_each_element() or friends
+ *
+ * This function returns %true if all the data was parsed or considered
+ * while walking the elements. Only use this if your for_each_element()
+ * loop cannot be broken out of, otherwise it always returns %false.
+ *
+ * If some data was malformed, this returns %false since the last parsed
+ * element will not fill the whole remaining data.
+ */
+static inline bool for_each_element_completed(const struct element *element,
+                                             const void *data, size_t datalen)
+{
+       return (u8 *)element == (u8 *)data + datalen;
+}
+
 #endif /* LINUX_IEEE80211_H */