#define IEEE80211_MAX_AID_S1G 8191
#define IEEE80211_MAX_TIM_LEN 251
#define IEEE80211_MAX_MESH_PEERINGS 63
+
+/* S1G encoding types */
+#define IEEE80211_S1G_TIM_ENC_MODE_BLOCK 0
+#define IEEE80211_S1G_TIM_ENC_MODE_SINGLE 1
+#define IEEE80211_S1G_TIM_ENC_MODE_OLB 2
+
/* Maximum size for the MA-UNITDATA primitive, 802.11 standard section
6.2.1.1.2.
return 1024 * tu;
}
-/**
- * ieee80211_check_tim - check if AID bit is set in TIM
- * @tim: the TIM IE
- * @tim_len: length of the TIM IE
- * @aid: the AID to look for
- * Return: whether or not traffic is indicated in the TIM for the given AID
- */
-static inline bool ieee80211_check_tim(const struct ieee80211_tim_ie *tim,
- u8 tim_len, u16 aid)
+static inline bool __ieee80211_check_tim(const struct ieee80211_tim_ie *tim,
+ u8 tim_len, u16 aid)
{
u8 mask;
u8 index, indexn1, indexn2;
return !!(tim->virtual_map[index] & mask);
}
+struct s1g_tim_aid {
+ u16 aid;
+ u8 target_blk; /* Target block index */
+ u8 target_subblk; /* Target subblock index */
+ u8 target_subblk_bit; /* Target subblock bit */
+};
+
+struct s1g_tim_enc_block {
+ u8 enc_mode;
+ bool inverse;
+ const u8 *ptr;
+ u8 len;
+
+ /*
+ * For an OLB encoded block that spans multiple blocks, this
+ * is the offset into the span described by that encoded block.
+ */
+ u8 olb_blk_offset;
+};
+
+/*
+ * Helper routines to quickly extract the length of an encoded block. Validation
+ * is also performed to ensure the length extracted lies within the TIM.
+ */
+
+static inline int ieee80211_s1g_len_bitmap(const u8 *ptr, const u8 *end)
+{
+ u8 blkmap;
+ u8 n_subblks;
+
+ if (ptr >= end)
+ return -EINVAL;
+
+ blkmap = *ptr;
+ n_subblks = hweight8(blkmap);
+
+ if (ptr + 1 + n_subblks > end)
+ return -EINVAL;
+
+ return 1 + n_subblks;
+}
+
+static inline int ieee80211_s1g_len_single(const u8 *ptr, const u8 *end)
+{
+ return (ptr + 1 > end) ? -EINVAL : 1;
+}
+
+static inline int ieee80211_s1g_len_olb(const u8 *ptr, const u8 *end)
+{
+ if (ptr >= end)
+ return -EINVAL;
+
+ return (ptr + 1 + *ptr > end) ? -EINVAL : 1 + *ptr;
+}
+
+/*
+ * Enumerate all encoded blocks until we find the encoded block that describes
+ * our target AID. OLB is a special case as a single encoded block can describe
+ * multiple blocks as a single encoded block.
+ */
+static inline int ieee80211_s1g_find_target_block(struct s1g_tim_enc_block *enc,
+ const struct s1g_tim_aid *aid,
+ const u8 *ptr, const u8 *end)
+{
+ /* need at least block-control octet */
+ while (ptr + 1 <= end) {
+ u8 ctrl = *ptr++;
+ u8 mode = ctrl & 0x03;
+ bool contains, inverse = ctrl & BIT(2);
+ u8 span, blk_off = ctrl >> 3;
+ int len;
+
+ switch (mode) {
+ case IEEE80211_S1G_TIM_ENC_MODE_BLOCK:
+ len = ieee80211_s1g_len_bitmap(ptr, end);
+ contains = blk_off == aid->target_blk;
+ break;
+ case IEEE80211_S1G_TIM_ENC_MODE_SINGLE:
+ len = ieee80211_s1g_len_single(ptr, end);
+ contains = blk_off == aid->target_blk;
+ break;
+ case IEEE80211_S1G_TIM_ENC_MODE_OLB:
+ len = ieee80211_s1g_len_olb(ptr, end);
+ /*
+ * An OLB encoded block can describe more then one
+ * block, meaning an encoded OLB block can span more
+ * then a single block.
+ */
+ if (len > 0) {
+ /* Minus one for the length octet */
+ span = DIV_ROUND_UP(len - 1, 8);
+ /*
+ * Check if our target block lies within the
+ * block span described by this encoded block.
+ */
+ contains = (aid->target_blk >= blk_off) &&
+ (aid->target_blk < blk_off + span);
+ }
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ if (len < 0)
+ return len;
+
+ if (contains) {
+ enc->enc_mode = mode;
+ enc->inverse = inverse;
+ enc->ptr = ptr;
+ enc->len = (u8)len;
+ enc->olb_blk_offset = blk_off;
+ return 0;
+ }
+
+ ptr += len;
+ }
+
+ return -ENOENT;
+}
+
+static inline bool ieee80211_s1g_parse_bitmap(struct s1g_tim_enc_block *enc,
+ struct s1g_tim_aid *aid)
+{
+ const u8 *ptr = enc->ptr;
+ u8 blkmap = *ptr++;
+
+ /*
+ * If our block bitmap does not contain a set bit that corresponds
+ * to our AID, it could mean a variety of things depending on if
+ * the encoding mode is inverted or not.
+ *
+ * 1. If inverted, it means the entire subblock is present and hence
+ * our AID has been set.
+ * 2. If not inverted, it means our subblock is not present and hence
+ * it is all zero meaning our AID is not set.
+ */
+ if (!(blkmap & BIT(aid->target_subblk)))
+ return enc->inverse;
+
+ /*
+ * Increment ptr by the number of set subblocks that appear before our
+ * target subblock. If our target subblock is 0, do nothing as ptr
+ * already points to our target subblock.
+ */
+ if (aid->target_subblk)
+ ptr += hweight8(blkmap & GENMASK(aid->target_subblk - 1, 0));
+
+ return !!(*ptr & BIT(aid->target_subblk_bit)) ^ enc->inverse;
+}
+
+static inline bool ieee80211_s1g_parse_single(struct s1g_tim_enc_block *enc,
+ struct s1g_tim_aid *aid)
+{
+ /*
+ * Single AID mode describes, as the name suggests, a single AID
+ * within the block described by the encoded block. The octet
+ * contains the 6 LSBs of the AID described in the block. The other
+ * 2 bits are reserved. When inversed, every single AID described
+ * by the current block have buffered traffic except for the AID
+ * described in the single AID octet.
+ */
+ return ((*enc->ptr & 0x3f) == (aid->aid & 0x3f)) ^ enc->inverse;
+}
+
+static inline bool ieee80211_s1g_parse_olb(struct s1g_tim_enc_block *enc,
+ struct s1g_tim_aid *aid)
+{
+ const u8 *ptr = enc->ptr;
+ u8 blk_len = *ptr++;
+ /*
+ * Given an OLB encoded block that describes multiple blocks,
+ * calculate the offset into the span. Then calculate the
+ * subblock location normally.
+ */
+ u16 span_offset = aid->target_blk - enc->olb_blk_offset;
+ u16 subblk_idx = span_offset * 8 + aid->target_subblk;
+
+ if (subblk_idx >= blk_len)
+ return enc->inverse;
+
+ return !!(ptr[subblk_idx] & BIT(aid->target_subblk_bit)) ^ enc->inverse;
+}
+
+/*
+ * An S1G PVB has 3 non optional encoding types, each that can be inverted.
+ * An S1G PVB is constructed with zero or more encoded block subfields. Each
+ * encoded block represents a single "block" of AIDs (64), and each encoded
+ * block can contain one of the 3 encoding types alongside a single bit for
+ * whether the bits should be inverted.
+ *
+ * As the standard makes no guarantee about the ordering of encoded blocks,
+ * we must parse every encoded block in the worst case scenario given an
+ * AID that lies within the last block.
+ */
+static inline bool ieee80211_s1g_check_tim(const struct ieee80211_tim_ie *tim,
+ u8 tim_len, u16 aid)
+{
+ int err;
+ struct s1g_tim_aid target_aid;
+ struct s1g_tim_enc_block enc_blk;
+
+ if (tim_len < 3)
+ return false;
+
+ target_aid.aid = aid;
+ target_aid.target_blk = (aid >> 6) & 0x1f;
+ target_aid.target_subblk = (aid >> 3) & 0x7;
+ target_aid.target_subblk_bit = aid & 0x7;
+
+ /*
+ * Find our AIDs target encoded block and fill &enc_blk with the
+ * encoded blocks information. If no entry is found or an error
+ * occurs return false.
+ */
+ err = ieee80211_s1g_find_target_block(&enc_blk, &target_aid,
+ tim->virtual_map,
+ (const u8 *)tim + tim_len + 2);
+ if (err)
+ return false;
+
+ switch (enc_blk.enc_mode) {
+ case IEEE80211_S1G_TIM_ENC_MODE_BLOCK:
+ return ieee80211_s1g_parse_bitmap(&enc_blk, &target_aid);
+ case IEEE80211_S1G_TIM_ENC_MODE_SINGLE:
+ return ieee80211_s1g_parse_single(&enc_blk, &target_aid);
+ case IEEE80211_S1G_TIM_ENC_MODE_OLB:
+ return ieee80211_s1g_parse_olb(&enc_blk, &target_aid);
+ default:
+ return false;
+ }
+}
+
+/**
+ * ieee80211_check_tim - check if AID bit is set in TIM
+ * @tim: the TIM IE
+ * @tim_len: length of the TIM IE
+ * @aid: the AID to look for
+ * @s1g: whether the TIM is from an S1G PPDU
+ * Return: whether or not traffic is indicated in the TIM for the given AID
+ */
+static inline bool ieee80211_check_tim(const struct ieee80211_tim_ie *tim,
+ u8 tim_len, u16 aid, bool s1g)
+{
+ return s1g ? ieee80211_s1g_check_tim(tim, tim_len, aid) :
+ __ieee80211_check_tim(tim, tim_len, aid);
+}
+
/**
* ieee80211_get_tdls_action - get TDLS action code
* @skb: the skb containing the frame, length will not be checked
projects / users / hch / misc.git / commitdiff