diff options
| author | Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de> | 2014-05-14 17:43:06 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-05-15 15:51:42 -0400 |
| commit | c3a6114f31600b94ee10ebf62e4d493b401ade87 (patch) | |
| tree | a854819cfede389764da13bcc0d7670e1f1e964f /include/net/ieee802154_netdev.h | |
| parent | 9dbccc30f3306114e1ca4a89da69be6d5f675782 (diff) | |
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 <phoebe.buckheister@itwm.fraunhofer.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/ieee802154_netdev.h')
| -rw-r--r-- | include/net/ieee802154_netdev.h | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/include/net/ieee802154_netdev.h b/include/net/ieee802154_netdev.h index 5a719ca892f..6e4d3e1071b 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 <net/ieee802154.h> #include <net/af_ieee802154.h> #include <linux/netdevice.h> #include <linux/skbuff.h> @@ -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; |