ieee802154: add ieee802154_skb_dst_pan helper
This patch adds ieee802154_skb_dst_pan function to get the pointer
address of the destination pan id at skb mac pointer.
Signed-off-by: Alexander Aring <aar@pengutronix.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/include/linux/ieee802154.h b/include/linux/ieee802154.h
index acedbb6..91f4665 100644
--- a/include/linux/ieee802154.h
+++ b/include/linux/ieee802154.h
@@ -31,6 +31,8 @@
#define IEEE802154_MIN_PSDU_LEN 9
#define IEEE802154_FCS_LEN 2
#define IEEE802154_MAX_AUTH_TAG_LEN 16
+#define IEEE802154_FC_LEN 2
+#define IEEE802154_SEQ_LEN 1
/* General MAC frame format:
* 2 bytes: Frame Control
@@ -221,9 +223,14 @@
#define IEEE802154_FCTL_ACKREQ 0x0020
#define IEEE802154_FCTL_SECEN 0x0004
#define IEEE802154_FCTL_INTRA_PAN 0x0040
+#define IEEE802154_FCTL_DADDR 0x0c00
#define IEEE802154_FTYPE_DATA 0x0001
+#define IEEE802154_FCTL_ADDR_NONE 0x0000
+#define IEEE802154_FCTL_DADDR_SHORT 0x0800
+#define IEEE802154_FCTL_DADDR_EXTENDED 0x0c00
+
/*
* ieee802154_is_data - check if type is IEEE802154_FTYPE_DATA
* @fc: frame control bytes in little-endian byteorder
@@ -261,6 +268,15 @@
return fc & cpu_to_le16(IEEE802154_FCTL_INTRA_PAN);
}
+/*
+ * ieee802154_daddr_mode - get daddr mode from fc
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline __le16 ieee802154_daddr_mode(__le16 fc)
+{
+ return fc & cpu_to_le16(IEEE802154_FCTL_DADDR);
+}
+
/**
* ieee802154_is_valid_psdu_len - check if psdu len is valid
* available lengths:
diff --git a/include/net/mac802154.h b/include/net/mac802154.h
index e465c855..b3f7cd8 100644
--- a/include/net/mac802154.h
+++ b/include/net/mac802154.h
@@ -258,6 +258,35 @@
}
/**
+ * ieee802154_skb_dst_pan - get the pointer to destination pan field
+ * @fc: mac header frame control field
+ * @skb: skb where the destination pan pointer will be get from
+ */
+static inline unsigned char *ieee802154_skb_dst_pan(__le16 fc,
+ const struct sk_buff *skb)
+{
+ unsigned char *dst_pan;
+
+ switch (ieee802154_daddr_mode(fc)) {
+ case cpu_to_le16(IEEE802154_FCTL_ADDR_NONE):
+ dst_pan = NULL;
+ break;
+ case cpu_to_le16(IEEE802154_FCTL_DADDR_SHORT):
+ case cpu_to_le16(IEEE802154_FCTL_DADDR_EXTENDED):
+ dst_pan = skb_mac_header(skb) +
+ IEEE802154_FC_LEN +
+ IEEE802154_SEQ_LEN;
+ break;
+ default:
+ WARN_ONCE(1, "invalid addr mode detected");
+ dst_pan = NULL;
+ break;
+ }
+
+ return dst_pan;
+}
+
+/**
* ieee802154_be64_to_le64 - copies and convert be64 to le64
* @le64_dst: le64 destination pointer
* @be64_src: be64 source pointer
