From c3a6114f31600b94ee10ebf62e4d493b401ade87 Mon Sep 17 00:00:00 2001 From: Phoebe Buckheister Date: Wed, 14 May 2014 17:43:06 +0200 Subject: ieee802154: add definitions for link-layer security and header functions When dealing with 802.15.4, one often has to know the maximum payload size for a given packet. This depends on many factors, one of which is whether or not a security header is present in the frame. These definitions and functions provide an easy way for any upper layer to calculate the maximum payload size for a packet. The first obvious user for this is 6lowpan, which duplicates this calculation and gets it partially wrong because it ignores security headers. Signed-off-by: Phoebe Buckheister Signed-off-by: David S. Miller --- include/net/ieee802154_netdev.h | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'include/net/ieee802154_netdev.h') diff --git a/include/net/ieee802154_netdev.h b/include/net/ieee802154_netdev.h index 5a719ca892f4..6e4d3e1071b5 100644 --- a/include/net/ieee802154_netdev.h +++ b/include/net/ieee802154_netdev.h @@ -27,6 +27,7 @@ #ifndef IEEE802154_NETDEVICE_H #define IEEE802154_NETDEVICE_H +#include #include #include #include @@ -114,6 +115,34 @@ int ieee802154_hdr_pull(struct sk_buff *skb, struct ieee802154_hdr *hdr); int ieee802154_hdr_peek_addrs(const struct sk_buff *skb, struct ieee802154_hdr *hdr); +/* parses the full 802.15.4 header 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(const struct sk_buff *skb, struct ieee802154_hdr *hdr); + +int ieee802154_max_payload(const struct ieee802154_hdr *hdr); + +static inline int +ieee802154_sechdr_authtag_len(const struct ieee802154_sechdr *sec) +{ + switch (sec->level) { + case IEEE802154_SCF_SECLEVEL_MIC32: + case IEEE802154_SCF_SECLEVEL_ENC_MIC32: + return 4; + case IEEE802154_SCF_SECLEVEL_MIC64: + case IEEE802154_SCF_SECLEVEL_ENC_MIC64: + return 8; + case IEEE802154_SCF_SECLEVEL_MIC128: + case IEEE802154_SCF_SECLEVEL_ENC_MIC128: + return 16; + case IEEE802154_SCF_SECLEVEL_NONE: + case IEEE802154_SCF_SECLEVEL_ENC: + default: + return 0; + } +} + static inline int ieee802154_hdr_length(struct sk_buff *skb) { struct ieee802154_hdr hdr; -- cgit v1.2.3