/*
* Copyright (c) 2015, SICS Swedish ICT.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of the Contiki operating system.
*
*/
/**
* \file
* IEEE 802.15.4e Information Element (IE) creation and parsing.
* \author
* Simon Duquennoy <simonduq@sics.se>
*/
#include <string.h>
#include "net/mac/frame802154e-ie.h"
#define DEBUG DEBUG_NONE
#include "net/net-debug.h"
/* c.f. IEEE 802.15.4e Table 4b */
enum ieee802154e_header_ie_id {
HEADER_IE_LE_CSL = 0x1a,
HEADER_IE_LE_RIT,
HEADER_IE_DSME_PAN_DESCRIPTOR,
HEADER_IE_RZ_TIME,
HEADER_IE_ACK_NACK_TIME_CORRECTION,
HEADER_IE_GACK,
HEADER_IE_LOW_LATENCY_NETWORK_INFO,
HEADER_IE_LIST_TERMINATION_1 = 0x7e,
HEADER_IE_LIST_TERMINATION_2 = 0x7f,
};
/* c.f. IEEE 802.15.4e Table 4c */
enum ieee802154e_payload_ie_id {
PAYLOAD_IE_ESDU = 0,
PAYLOAD_IE_MLME,
PAYLOAD_IE_LIST_TERMINATION = 0xf,
};
/* c.f. IEEE 802.15.4e Table 4d */
enum ieee802154e_mlme_short_subie_id {
MLME_SHORT_IE_TSCH_SYNCHRONIZATION = 0x1a,
MLME_SHORT_IE_TSCH_SLOFTRAME_AND_LINK,
MLME_SHORT_IE_TSCH_TIMESLOT,
MLME_SHORT_IE_TSCH_HOPPING_TIMING,
MLME_SHORT_IE_TSCH_EB_FILTER,
MLME_SHORT_IE_TSCH_MAC_METRICS_1,
MLME_SHORT_IE_TSCH_MAC_METRICS_2,
};
/* c.f. IEEE 802.15.4e Table 4e */
enum ieee802154e_mlme_long_subie_id {
MLME_LONG_IE_TSCH_CHANNEL_HOPPING_SEQUENCE = 0x9,
};
#define WRITE16(buf, val) \
do { ((uint8_t *)(buf))[0] = (val) & 0xff; \
((uint8_t *)(buf))[1] = ((val) >> 8) & 0xff; } while(0);
#define READ16(buf, var) \
(var) = ((uint8_t *)(buf))[0] | ((uint8_t *)(buf))[1] << 8
/* Create a header IE 2-byte descriptor */
static void
create_header_ie_descriptor(uint8_t *buf, uint8_t element_id, int ie_len)
{
uint16_t ie_desc;
/* Header IE descriptor: b0-6: len, b7-14: element id:, b15: type: 0 */
ie_desc = (ie_len & 0x7f) + ((element_id & 0xff) << 7);
WRITE16(buf, ie_desc);
}
/* Create a payload IE 2-byte descriptor */
static void
create_payload_ie_descriptor(uint8_t *buf, uint8_t group_id, int ie_len)
{
uint16_t ie_desc;
/* MLME Long IE descriptor: b0-10: len, b11-14: group id:, b15: type: 1 */
ie_desc = (ie_len & 0x07ff) + ((group_id & 0x0f) << 11) + (1 << 15);
WRITE16(buf, ie_desc);
}
/* Create a MLME short IE 2-byte descriptor */
static void
create_mlme_short_ie_descriptor(uint8_t *buf, uint8_t sub_id, int ie_len)
{
uint16_t ie_desc;
/* MLME Short IE descriptor: b0-7: len, b8-14: sub id:, b15: type: 0 */
ie_desc = (ie_len & 0xff) + ((sub_id & 0x7f) << 8);
WRITE16(buf, ie_desc);
}
/* Create a MLME long IE 2-byte descriptor */
static void
create_mlme_long_ie_descriptor(uint8_t *buf, uint8_t sub_id, int ie_len)
{
uint16_t ie_desc;
/* MLME Long IE descriptor: b0-10: len, b11-14: sub id:, b15: type: 1 */
ie_desc = (ie_len & 0x07ff) + ((sub_id & 0x0f) << 11) + (1 << 15);
WRITE16(buf, ie_desc);
}
/* Header IE. ACK/NACK time correction. Used in enhanced ACKs */
int
frame80215e_create_ie_header_ack_nack_time_correction(uint8_t *buf, int len,
struct ieee802154_ies *ies)
{
int ie_len = 2;
if(len >= 2 + ie_len && ies != NULL) {
int16_t drift_us;
uint16_t time_sync_field;
drift_us = ies->ie_time_correction;
time_sync_field = drift_us & 0x0fff;
if(ies->ie_is_nack) {
time_sync_field |= 0x8000;
}
WRITE16(buf+2, time_sync_field);
create_header_ie_descriptor(buf, HEADER_IE_ACK_NACK_TIME_CORRECTION, ie_len);
return 2 + ie_len;
} else {
return -1;
}
}
/* Header IE. List termination 1 (Signals the end of the Header IEs when
* followed by payload IEs) */
int
frame80215e_create_ie_header_list_termination_1(uint8_t *buf, int len,
struct ieee802154_ies *ies)
{
int ie_len = 0;
if(len >= 2 + ie_len && ies != NULL) {
create_header_ie_descriptor(buf, HEADER_IE_LIST_TERMINATION_1, 0);
return 2 + ie_len;
} else {
return -1;
}
}
/* Header IE. List termination 2 (Signals the end of the Header IEs when
* followed by an unformatted payload) */
int
frame80215e_create_ie_header_list_termination_2(uint8_t *buf, int len,
struct ieee802154_ies *ies)
{
int ie_len = 0;
if(len >= 2 + ie_len && ies != NULL) {
create_header_ie_descriptor(buf, HEADER_IE_LIST_TERMINATION_2, 0);
return 2 + ie_len;
} else {
return -1;
}
}
/* Payload IE. List termination */
int
frame80215e_create_ie_payload_list_termination(uint8_t *buf, int len,
struct ieee802154_ies *ies)
{
int ie_len = 0;
if(len >= 2 + ie_len && ies != NULL) {
create_payload_ie_descriptor(buf, PAYLOAD_IE_LIST_TERMINATION, 0);
return 2 + ie_len;
} else {
return -1;
}
}
/* Payload IE. MLME. Used to nest sub-IEs */
int
frame80215e_create_ie_mlme(uint8_t *buf, int len,
struct ieee802154_ies *ies)
{
int ie_len = 0;
if(len >= 2 + ie_len && ies != NULL) {
/* The length of the outer MLME IE is the total length of sub-IEs */
create_payload_ie_descriptor(buf, PAYLOAD_IE_MLME, ies->ie_mlme_len);
return 2 + ie_len;
} else {
return -1;
}
}
/* MLME sub-IE. TSCH synchronization. Used in EBs: ASN and join priority */
int
frame80215e_create_ie_tsch_synchronization(uint8_t *buf, int len,
struct ieee802154_ies *ies)
{
int ie_len = 6;
if(len >= 2 + ie_len && ies != NULL) {
buf[2] = ies->ie_asn.ls4b;
buf[3] = ies->ie_asn.ls4b >> 8;
buf[4] = ies->ie_asn.ls4b >> 16;
buf[5] = ies->ie_asn.ls4b >> 24;
buf[6] = ies->ie_asn.ms1b;
buf[7] = ies->ie_join_priority;
create_mlme_short_ie_descriptor(buf, MLME_SHORT_IE_TSCH_SYNCHRONIZATION, ie_len);
return 2 + ie_len;
} else {
return -1;
}
}
/* MLME sub-IE. TSCH slotframe and link. Used in EBs: initial schedule */
int
frame80215e_create_ie_tsch_slotframe_and_link(uint8_t *buf, int len,
struct ieee802154_ies *ies)
{
if(ies != NULL) {
int i;
int num_slotframes = ies->ie_tsch_slotframe_and_link.num_slotframes;
int num_links = ies->ie_tsch_slotframe_and_link.num_links;
int ie_len = 1 + num_slotframes * (4 + 5 * num_links);
if(num_slotframes > 1 || num_links > FRAME802154E_IE_MAX_LINKS
|| len < 2 + ie_len) {
/* We support only 0 or 1 slotframe in this IE and a predefined maximum number of links */
return -1;
}
/* Insert IE */
buf[2] = num_slotframes;
/* Insert slotframe */
if(num_slotframes == 1) {
buf[2 + 1] = ies->ie_tsch_slotframe_and_link.slotframe_handle;
WRITE16(buf + 2 + 2, ies->ie_tsch_slotframe_and_link.slotframe_size);
buf[2 + 4] = num_links;
/* Loop over links */
for(i = 0; i < num_links; i++) {
/* Insert links */
WRITE16(buf + 2 + 5 + i * 5, ies->ie_tsch_slotframe_and_link.links[i].timeslot);
WRITE16(buf + 2 + 5 + i * 5 + 2, ies->ie_tsch_slotframe_and_link.links[i].channel_offset);
buf[2 + 5 + i * 5 + 4] = ies->ie_tsch_slotframe_and_link.links[i].link_options;
}
}
create_mlme_short_ie_descriptor(buf, MLME_SHORT_IE_TSCH_SLOFTRAME_AND_LINK, ie_len);
return 2 + ie_len;
} else {
return -1;
}
}
/* MLME sub-IE. TSCH timeslot. Used in EBs: timeslot template (timing) */
int
frame80215e_create_ie_tsch_timeslot(uint8_t *buf, int len,
struct ieee802154_ies *ies)
{
int ie_len;
if(ies == NULL) {
return -1;
}
/* Only ID if ID == 0, else full timing description */
ie_len = ies->ie_tsch_timeslot_id == 0 ? 1 : 25;
if(len >= 2 + ie_len) {
buf[2] = ies->ie_tsch_timeslot_id;
if(ies->ie_tsch_timeslot_id != 0) {
int i;
for(i = 0; i < tsch_ts_elements_count; i++) {
WRITE16(buf + 3 + 2 * i, ies->ie_tsch_timeslot[i]);
}
}
create_mlme_short_ie_descriptor(buf, MLME_SHORT_IE_TSCH_TIMESLOT, ie_len);
return 2 + ie_len;
} else {
return -1;
}
}
/* MLME sub-IE. TSCH channel hopping sequence. Used in EBs: hopping sequence */
int
frame80215e_create_ie_tsch_channel_hopping_sequence(uint8_t *buf, int len,
struct ieee802154_ies *ies)
{
int ie_len;
if(ies == NULL || ies->ie_hopping_sequence_len > sizeof(ies->ie_hopping_sequence_list)) {
return -1;
}
ie_len = ies->ie_channel_hopping_sequence_id == 0 ? 1 : 12 + ies->ie_hopping_sequence_len;
if(len >= 2 + ie_len && ies != NULL) {
buf[2] = ies->ie_channel_hopping_sequence_id;
buf[3] = 0; /* channel page */
WRITE16(buf + 4, 0); /* number of channels */
WRITE16(buf + 6, 0); /* phy configuration */
WRITE16(buf + 8, 0);
/* Extended bitmap. Size: 0 */
WRITE16(buf + 10, ies->ie_hopping_sequence_len); /* sequence len */
memcpy(buf + 12, ies->ie_hopping_sequence_list, ies->ie_hopping_sequence_len); /* sequence list */
WRITE16(buf + 12 + ies->ie_hopping_sequence_len, 0); /* current hop */
create_mlme_long_ie_descriptor(buf, MLME_LONG_IE_TSCH_CHANNEL_HOPPING_SEQUENCE, ie_len);
return 2 + ie_len;
} else {
return -1;
}
}
/* Parse a header IE */
static int
frame802154e_parse_header_ie(const uint8_t *buf, int len,
uint8_t element_id, struct ieee802154_ies *ies)
{
switch(element_id) {
case HEADER_IE_ACK_NACK_TIME_CORRECTION:
if(len == 2) {
if(ies != NULL) {
/* If the originator was a time source neighbor, the receiver adjust
* its own clock by incorporating the received drift correction */
uint16_t time_sync_field = 0;
int16_t drift_us = 0;
/* Extract drift correction from Sync-IE, cast from 12 to 16-bit,
* and convert it to RTIMER ticks.
* See page 88 in IEEE Std 802.15.4e-2012. */
READ16(buf, time_sync_field);
/* First extract NACK */
ies->ie_is_nack = (time_sync_field & (uint16_t)0x8000) ? 1 : 0;
/* Then cast from 12 to 16 bit signed */
if(time_sync_field & 0x0800) { /* Negative integer */
drift_us = time_sync_field | 0xf000;
} else { /* Positive integer */
drift_us = time_sync_field & 0x0fff;
}
/* Convert to RTIMER ticks */
ies->ie_time_correction = drift_us;
}
return len;
}
break;
}
return -1;
}
/* Parse a MLME short IE */
static int
frame802154e_parse_mlme_short_ie(const uint8_t *buf, int len,
uint8_t sub_id, struct ieee802154_ies *ies)
{
switch(sub_id) {
case MLME_SHORT_IE_TSCH_SLOFTRAME_AND_LINK:
if(len >= 1) {
int i;
int num_slotframes = buf[0];
int num_links = buf[4];
if(num_slotframes == 0) {
return len;
}
if(num_slotframes <= 1 && num_links <= FRAME802154E_IE_MAX_LINKS
&& len == 1 + num_slotframes * (4 + 5 * num_links)) {
if(ies != NULL) {
/* We support only 0 or 1 slotframe in this IE and a predefined maximum number of links */
ies->ie_tsch_slotframe_and_link.num_slotframes = buf[0];
ies->ie_tsch_slotframe_and_link.slotframe_handle = buf[1];
READ16(buf + 2, ies->ie_tsch_slotframe_and_link.slotframe_size);
ies->ie_tsch_slotframe_and_link.num_links = buf[4];
for(i = 0; i < num_links; i++) {
READ16(buf + 5 + i * 5, ies->ie_tsch_slotframe_and_link.links[i].timeslot);
READ16(buf + 5 + i * 5 + 2, ies->ie_tsch_slotframe_and_link.links[i].channel_offset);
ies->ie_tsch_slotframe_and_link.links[i].link_options = buf[5 + i * 5 + 4];
}
}
return len;
}
}
break;
case MLME_SHORT_IE_TSCH_SYNCHRONIZATION:
if(len == 6) {
if(ies != NULL) {
ies->ie_asn.ls4b = (uint32_t)buf[0];
ies->ie_asn.ls4b |= (uint32_t)buf[1] << 8;
ies->ie_asn.ls4b |= (uint32_t)buf[2] << 16;
ies->ie_asn.ls4b |= (uint32_t)buf[3] << 24;
ies->ie_asn.ms1b = (uint8_t)buf[4];
ies->ie_join_priority = (uint8_t)buf[5];
}
return len;
}
break;
case MLME_SHORT_IE_TSCH_TIMESLOT:
if(len == 1 || len == 25) {
if(ies != NULL) {
ies->ie_tsch_timeslot_id = buf[0];
if(len == 25) {
int i;
for(i = 0; i < tsch_ts_elements_count; i++) {
READ16(buf+1+2*i, ies->ie_tsch_timeslot[i]);
}
}
}
return len;
}
break;
}
return -1;
}
/* Parse a MLME long IE */
static int
frame802154e_parse_mlme_long_ie(const uint8_t *buf, int len,
uint8_t sub_id, struct ieee802154_ies *ies)
{
switch(sub_id) {
case MLME_LONG_IE_TSCH_CHANNEL_HOPPING_SEQUENCE:
if(len > 0) {
if(ies != NULL) {
ies->ie_channel_hopping_sequence_id = buf[0];
if(len > 1) {
READ16(buf+8, ies->ie_hopping_sequence_len); /* sequence len */
if(ies->ie_hopping_sequence_len <= sizeof(ies->ie_hopping_sequence_list)
&& len == 12 + ies->ie_hopping_sequence_len) {
memcpy(ies->ie_hopping_sequence_list, buf+10, ies->ie_hopping_sequence_len); /* sequence list */
}
}
}
return len;
}
break;
}
return -1;
}
/* Parse all IEEE 802.15.4e Information Elements (IE) from a frame */
int
frame802154e_parse_information_elements(const uint8_t *buf, uint8_t buf_size,
struct ieee802154_ies *ies)
{
const uint8_t *start = buf;
uint16_t ie_desc;
uint8_t type;
uint8_t id;
uint16_t len = 0;
int nested_mlme_len = 0;
enum {PARSING_HEADER_IE, PARSING_PAYLOAD_IE, PARSING_MLME_SUBIE} parsing_state;
if(ies == NULL) {
return -1;
}
/* Always look for a header IE first (at least "list termination 1") */
parsing_state = PARSING_HEADER_IE;
ies->ie_payload_ie_offset = 0;
/* Loop over all IEs */
while(buf_size > 0) {
if(buf_size < 2) { /* Not enough space for IE descriptor */
return -1;
}
READ16(buf, ie_desc);
buf_size -= 2;
buf += 2;
type = ie_desc & 0x8000 ? 1 : 0; /* b15 */
PRINTF("frame802154e: ie type %u, current state %u\n", type, parsing_state);
switch(parsing_state) {
case PARSING_HEADER_IE:
if(type != 0) {
PRINTF("frame802154e: wrong type %04x\n", ie_desc);
return -1;
}
/* Header IE: 2 bytes descriptor, c.f. fig 48n in IEEE 802.15.4e */
len = ie_desc & 0x007f; /* b0-b6 */
id = (ie_desc & 0x7f80) >> 7; /* b7-b14 */
PRINTF("frame802154e: header ie len %u id %x\n", len, id);
switch(id) {
case HEADER_IE_LIST_TERMINATION_1:
if(len == 0) {
/* End of payload IE list, now expect payload IEs */
parsing_state = PARSING_PAYLOAD_IE;
ies->ie_payload_ie_offset = buf - start; /* Save IE header len */
PRINTF("frame802154e: list termination 1, look for payload IEs\n");
} else {
PRINTF("frame802154e: list termination 1, wrong len %u\n", len);
return -1;
}
break;
case HEADER_IE_LIST_TERMINATION_2:
/* End of IE parsing */
if(len == 0) {
ies->ie_payload_ie_offset = buf - start; /* Save IE header len */
PRINTF("frame802154e: list termination 2\n");
return buf + len - start;
} else {
PRINTF("frame802154e: list termination 2, wrong len %u\n", len);
return -1;
}
default:
if(len > buf_size || frame802154e_parse_header_ie(buf, len, id, ies) == -1) {
PRINTF("frame802154e: failed to parse\n");
return -1;
}
break;
}
break;
case PARSING_PAYLOAD_IE:
if(type != 1) {
PRINTF("frame802154e: wrong type %04x\n", ie_desc);
return -1;
}
/* Payload IE: 2 bytes descriptor, c.f. fig 48o in IEEE 802.15.4e */
len = ie_desc & 0x7ff; /* b0-b10 */
id = (ie_desc & 0x7800) >> 11; /* b11-b14 */
PRINTF("frame802154e: payload ie len %u id %x\n", len, id);
switch(id) {
case PAYLOAD_IE_MLME:
/* Now expect 'len' bytes of MLME sub-IEs */
parsing_state = PARSING_MLME_SUBIE;
nested_mlme_len = len;
len = 0; /* Reset len as we want to read subIEs and not jump over them */
PRINTF("frame802154e: entering MLME ie with len %u\n", nested_mlme_len);
break;
case PAYLOAD_IE_LIST_TERMINATION:
PRINTF("frame802154e: payload ie list termination %u\n", len);
return (len == 0) ? buf + len - start : -1;
default:
PRINTF("frame802154e: non-supported payload ie\n");
return -1;
}
break;
case PARSING_MLME_SUBIE:
/* MLME sub-IE: 2 bytes descriptor, c.f. fig 48q in IEEE 802.15.4e */
/* type == 0 means short sub-IE, type == 1 means long sub-IE */
if(type == 0) {
/* Short sub-IE, c.f. fig 48r in IEEE 802.15.4e */
len = ie_desc & 0x00ff; /* b0-b7 */
id = (ie_desc & 0x7f00) >> 8; /* b8-b14 */
PRINTF("frame802154e: short mlme ie len %u id %x\n", len, id);
if(len > buf_size || frame802154e_parse_mlme_short_ie(buf, len, id, ies) == -1) {
PRINTF("frame802154e: failed to parse ie\n");
return -1;
}
} else {
/* Long sub-IE, c.f. fig 48s in IEEE 802.15.4e */
len = ie_desc & 0x7ff; /* b0-b10 */
id = (ie_desc & 0x7800) >> 11; /* b11-b14 */
PRINTF("frame802154e: long mlme ie len %u id %x\n", len, id);
if(len > buf_size || frame802154e_parse_mlme_long_ie(buf, len, id, ies) == -1) {
PRINTF("frame802154e: failed to parse ie\n");
return -1;
}
}
/* Update remaining nested MLME len */
nested_mlme_len -= 2 + len;
if(nested_mlme_len < 0) {
PRINTF("frame802154e: found more sub-IEs than initially advertised\n");
/* We found more sub-IEs than initially advertised */
return -1;
}
if(nested_mlme_len == 0) {
PRINTF("frame802154e: end of MLME IE parsing\n");
/* End of IE parsing, look for another payload IE */
parsing_state = PARSING_PAYLOAD_IE;
}
break;
}
buf += len;
buf_size -= len;
}
if(parsing_state == PARSING_HEADER_IE) {
ies->ie_payload_ie_offset = buf - start; /* Save IE header len */
}
return buf - start;
}