ieee802154: add header structs with endiannes and operations
This patch provides a set of structures to represent 802.15.4 MAC
headers, and a set of operations to push/pull/peek these structs from
skbs. We cannot simply pointer-cast the skb MAC header pointer to these
structs, because 802.15.4 headers are wildly variable - depending on the
first three bytes, virtually all other fields of the header may be
present or not, and be present with different lengths.
The new header creation/parsing routines also support 802.15.4 security
headers, which are currently not supported by the mac802154
implementation of the protocol.
Signed-off-by: Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ieee802154_netdev.h b/include/net/ieee802154_netdev.h
index e4810d5..c3fc33a 100644
--- a/include/net/ieee802154_netdev.h
+++ b/include/net/ieee802154_netdev.h
@@ -28,6 +28,28 @@
#define IEEE802154_NETDEVICE_H
#include <net/af_ieee802154.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+
+struct ieee802154_sechdr {
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+ u8 level:3,
+ key_id_mode:2,
+ reserved:3;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+ u8 reserved:3,
+ key_id_mode:2,
+ level:3;
+#else
+#error "Please fix <asm/byteorder.h>"
+#endif
+ u8 key_id;
+ __le32 frame_counter;
+ union {
+ __le32 short_src;
+ __le64 extended_src;
+ };
+};
struct ieee802154_addr {
u8 mode;
@@ -38,6 +60,71 @@
};
};
+struct ieee802154_hdr_fc {
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+ u16 type:3,
+ security_enabled:1,
+ frame_pending:1,
+ ack_request:1,
+ intra_pan:1,
+ reserved:3,
+ dest_addr_mode:2,
+ version:2,
+ source_addr_mode:2;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+ u16 reserved:1,
+ intra_pan:1,
+ ack_request:1,
+ frame_pending:1,
+ security_enabled:1,
+ type:3,
+ source_addr_mode:2,
+ version:2,
+ dest_addr_mode:2,
+ reserved2:2;
+#else
+#error "Please fix <asm/byteorder.h>"
+#endif
+};
+
+struct ieee802154_hdr {
+ struct ieee802154_hdr_fc fc;
+ u8 seq;
+ struct ieee802154_addr source;
+ struct ieee802154_addr dest;
+ struct ieee802154_sechdr sec;
+};
+
+/* pushes hdr onto the skb. fields of hdr->fc that can be calculated from
+ * the contents of hdr will be, and the actual value of those bits in
+ * hdr->fc will be ignored. this includes the INTRA_PAN bit and the frame
+ * version, if SECEN is set.
+ */
+int ieee802154_hdr_push(struct sk_buff *skb, const struct ieee802154_hdr *hdr);
+
+/* pulls the entire 802.15.4 header off of the skb, including the security
+ * header, and performs pan id decompression
+ */
+int ieee802154_hdr_pull(struct sk_buff *skb, struct ieee802154_hdr *hdr);
+
+/* parses the frame control, sequence number of address fields in a given skb
+ * and stores them into hdr, performing pan id decompression and length checks
+ * to be suitable for use in header_ops.parse
+ */
+int ieee802154_hdr_peek_addrs(const struct sk_buff *skb,
+ struct ieee802154_hdr *hdr);
+
+static inline int ieee802154_hdr_length(struct sk_buff *skb)
+{
+ struct ieee802154_hdr hdr;
+ int len = ieee802154_hdr_pull(skb, &hdr);
+
+ if (len > 0)
+ skb_push(skb, len);
+
+ return len;
+}
+
static inline bool ieee802154_addr_equal(const struct ieee802154_addr *a1,
const struct ieee802154_addr *a2)
{