uint16_t ieee802154_compute_header_size(struct net_if *iface,
struct in6_addr *dst)
{
uint16_t hdr_len = sizeof(struct ieee802154_fcf_seq);
/** if dst is NULL, we'll consider it as a brodcast header */
if (!dst ||
net_is_ipv6_addr_mcast(dst) ||
net_is_ipv6_addr_unspecified(dst)) {
/* 4 dst pan/addr + 8 src addr */
hdr_len += IEEE802154_PAN_ID_LENGTH +
IEEE802154_SHORT_ADDR_LENGTH +
IEEE802154_EXT_ADDR_LENGTH;
} else {
struct net_nbr *nbr;
nbr = net_ipv6_nbr_lookup(iface, dst);
if (nbr) {
/* ToDo: handle short addresses */
/* dst pan/addr + src addr */
hdr_len += IEEE802154_PAN_ID_LENGTH +
(IEEE802154_EXT_ADDR_LENGTH * 2);
} else {
/* src pan/addr only */
hdr_len += IEEE802154_PAN_ID_LENGTH +
IEEE802154_EXT_ADDR_LENGTH;
}
}
/* Todo: handle security aux header */
NET_DBG("Computed size of %u", hdr_len);
return hdr_len;
}
static inline enum ieee802154_addressing_mode
get_dst_addr_mode(struct net_if *iface, struct in6_addr *dst,
struct net_nbr **nbr, bool *broadcast)
{
if (net_is_ipv6_addr_mcast(dst) ||
net_is_ipv6_addr_unspecified(dst)) {
*broadcast = true;
*nbr = NULL;
return IEEE802154_ADDR_MODE_SHORT;
}
*broadcast = false;
/* ToDo: Prefer short addr, when _associated_ to a PAN
* if associated:
* - Check if dst is known nb and has short addr
* - if so, return short.
*/
*nbr = net_ipv6_nbr_lookup(iface, dst);
if (!*nbr) {
return IEEE802154_ADDR_MODE_NONE;
}
return IEEE802154_ADDR_MODE_EXTENDED;
}
u16_t ieee802154_compute_header_size(struct net_if *iface,
struct in6_addr *dst)
{
u16_t hdr_len = sizeof(struct ieee802154_fcf_seq);
#ifdef CONFIG_NET_L2_IEEE802154_SECURITY
struct ieee802154_security_ctx *sec_ctx =
&((struct ieee802154_context *)net_if_l2_data(iface))->sec_ctx;
#endif
/** if dst is NULL, we'll consider it as a brodcast header */
if (!dst ||
net_is_ipv6_addr_mcast(dst) ||
net_is_ipv6_addr_unspecified(dst)) {
NET_DBG("Broadcast destination");
/* 4 dst pan/addr + 8 src addr */
hdr_len += IEEE802154_PAN_ID_LENGTH +
IEEE802154_SHORT_ADDR_LENGTH +
IEEE802154_EXT_ADDR_LENGTH;
if (IS_ENABLED(CONFIG_NET_L2_IEEE802154_SECURITY)) {
NET_DBG("Broadcast packet do not have security");
goto done;
}
} else {
struct net_nbr *nbr;
nbr = net_ipv6_nbr_lookup(iface, dst);
if (nbr) {
/* ToDo: handle short addresses */
/* dst pan/addr + src addr */
hdr_len += IEEE802154_PAN_ID_LENGTH +
(IEEE802154_EXT_ADDR_LENGTH * 2);
} else {
/* src pan/addr only */
hdr_len += IEEE802154_PAN_ID_LENGTH +
IEEE802154_EXT_ADDR_LENGTH;
}
}
#ifdef CONFIG_NET_L2_IEEE802154_SECURITY
if (sec_ctx->level == IEEE802154_SECURITY_LEVEL_NONE) {
goto done;
}
/* Compute aux-sec hdr size and add it to hdr_len */
hdr_len += IEEE802154_SECURITY_CF_LENGTH +
IEEE802154_SECURITY_FRAME_COUNTER_LENGTH;
switch (sec_ctx->key_mode) {
case IEEE802154_KEY_ID_MODE_IMPLICIT:
/* The only mode supported for now,
* generate_aux_securiy_hdr() will fail on other modes
*/
break;
case IEEE802154_KEY_ID_MODE_INDEX:
hdr_len += IEEE8021254_KEY_ID_FIELD_INDEX_LENGTH;
break;
case IEEE802154_KEY_ID_MODE_SRC_4_INDEX:
hdr_len += IEEE8021254_KEY_ID_FIELD_SRC_4_INDEX_LENGTH;
break;
case IEEE802154_KEY_ID_MODE_SRC_8_INDEX:
hdr_len += IEEE8021254_KEY_ID_FIELD_SRC_8_INDEX_LENGTH;
}
/* This is a _HACK_: as net pkt do not let the possibility to
* reserve tailroom - here for authentication tag - it reserves
* it in headroom so the payload won't occupy all the left space
* and then when it will come to finalize the data frame it will
* reduce the reserve space by the tag size, move the payload
* backward accordingly, and only then:
* run the encryption/authentication which will fill the tag
* space in the end.
*/
if (sec_ctx->level < IEEE802154_SECURITY_LEVEL_ENC) {
hdr_len += level_2_tag_size[sec_ctx->level];
} else {
hdr_len += level_2_tag_size[sec_ctx->level - 4];
}
#endif /* CONFIG_NET_L2_IEEE802154_SECURITY */
done:
NET_DBG("Computed size of %u", hdr_len);
return hdr_len;
}
