Add TLV packet support

Guo Wenxue

2024-04-11 5b381c80976c76bb7e0d779f1ff878416c93db78

Add TLV packet support

Signed-off-by: Guo Wenxue <guowenxue@gmail.com>

 project/socketd/booster/packet.c

@@ -46,12 +46,13 @@
    return 0;
}

int packet_segmented_pack(pack_info_t *pack_info, char *pack_buf, int size)
int packet_segmented_pack(pack_info_t *pack_info, uint8_t *pack_buf, int size)
{
    char              strtime[TIME_LEN] = {'\0'};
    struct tm        *ptm;
    char             *buf = (char *)pack_buf;

    if( !pack_info || !pack_buf || size<=0 )
    if( !pack_info || !buf || size<=0 )
    {
        log_error("Invalid input arguments\n");
        return -1;
@@ -62,18 +63,19 @@
            ptm->tm_year+1900, ptm->tm_mon+1, ptm->tm_mday,
            ptm->tm_hour, ptm->tm_min, ptm->tm_sec);

    memset(pack_buf, 0, size);
    snprintf(pack_buf, size, "%s|%s|%.3f", pack_info->devid, strtime, pack_info->temper);
    memset(buf, 0, size);
    snprintf(buf, size, "%s|%s|%.3f", pack_info->devid, strtime, pack_info->temper);

    return strlen(pack_buf);
    return strlen(buf);
}

int packet_json_pack(pack_info_t *pack_info, char *pack_buf, int size)
int packet_json_pack(pack_info_t *pack_info, uint8_t *pack_buf, int size)
{
    char              strtime[TIME_LEN] = {'\0'};
    struct tm        *ptm;
    char             *buf = (char *)pack_buf;

    if( !pack_info || !pack_buf || size<=0 )
    if( !pack_info || !buf || size<=0 )
    {
        log_error("Invalid input arguments\n");
        return -1;
@@ -84,10 +86,122 @@
            ptm->tm_year+1900, ptm->tm_mon+1, ptm->tm_mday,
            ptm->tm_hour, ptm->tm_min, ptm->tm_sec);

    memset(pack_buf, 0, size);
    snprintf(pack_buf, size, "{\"devid\":\"%s\", \"time\":\"%s\",\"temperature\":\"%.3f\"}",
    memset(buf, 0, size);
    snprintf(buf, size, "{\"devid\":\"%s\", \"time\":\"%s\",\"temperature\":\"%.3f\"}",
            pack_info->devid, strtime, pack_info->temper);

    return strlen(pack_buf);
    return strlen(buf);
}

/*
 * The CRC-ITU-T, also known as CRC-16-ITU-T or CRC-16-V.41, uses the polynomial:
 *     0x1021:  x^16 + x^12 + x^5 + 1
 */

#define CRC16_ITU_T_POLY 0x1021   /* Define the CRC-ITU-T polynomial */
static uint16_t crc_itu_t(const uint8_t *data, size_t length)
{
    uint16_t          crc = 0xFFFF;
    size_t            i, j;

    for (i=0; i<length; i++)
    {
        crc ^= ((uint16_t)data[i] << 8);

        for(j=0; j<8; j++)
        {
            if (crc & 0x8000)
            {
                crc = (crc << 1) ^ CRC16_ITU_T_POLY;
            }
            else
            {
                crc <<= 1;
            }
        }
    }

    return crc;
}

uint16_t to_big_endian(uint16_t num)
{
    return (num << 8) | (num >> 8);
}

/* TLV(Tag Length Value) PDU(Protocal Data Unit) format:
 *
 * +-----------+-----------+------------+-------------+-------------+
 * | Header(2B)|  Tag(1B)  | Length(2B) |  Value(nB)  |  CRC16(2B)  |
 * +-----------+-----------+------------+-------------+-------------+
 *
 * Header(2B): 0xFE 0xFD
 *    Tag(1B): 0x01->temperature 0x02->Humidity 0x03->Noisy ...
 * Length(2B): Data value length
 *  Value(nB): Data value
 *  CRC16(2B): CRC from Header to Value
 */

int packet_tlv_pack(pack_info_t *pack_info, uint8_t *pack_buf, int size)
{
    struct tm          *ptm;
    int                 ofset = 0;
    uint16_t            crc;

    if( !pack_info || !pack_buf || size<TLV_MINSIZE )

    {
        log_error("Invalid input arguments\n");
        return -1;
    }

    /*+----------------------+
     *|    TLV Header(2B)    |
     *+----------------------+*/
    *(uint16_t *)pack_buf = to_big_endian(TLV_HEADER);
    ofset += 2;

    /*+----------------------+
     *|      TLV Tag(1B)     |
     *+----------------------+*/
    pack_buf[ofset++] = TAG_TEMPERATURE;

    /* Skip data length here, we will calculate it later */
    ofset += 2;

    /*+----------------------+
     *|  payload data value  |
     *+----------------------+*/

    /* 6 bytes sample time */
    ptm = &pack_info->sample_time;
    pack_buf[ofset++] = (uint8_t)(ptm->tm_year+1900-2000);
    pack_buf[ofset++] = (uint8_t)(ptm->tm_mon+1);
    pack_buf[ofset++] = (uint8_t)(ptm->tm_mday);
    pack_buf[ofset++] = (uint8_t)(ptm->tm_hour);
    pack_buf[ofset++] = (uint8_t)(ptm->tm_min);
    pack_buf[ofset++] = (uint8_t)(ptm->tm_sec);

    /* 8 bytes device SN */
    strncpy((char *)(pack_buf+ofset), pack_info->devid, DEVID_LEN);
    ofset += DEVID_LEN;

    /* 2 bytes temperature value */
    pack_buf[ofset++] = (int)pack_info->temper;  /* integer part */
    pack_buf[ofset++] = (((int)(pack_info->temper*100))%100); /* fractional part */

    /*+----------------------+
     *|    TLV Length(2B)    |
     *+----------------------+*/
    *(uint16_t *)(pack_buf+3) = (ofset-5);

    /*+----------------------+
     *|      TLV CRC(2B)     |
     *+----------------------+*/
    crc = crc_itu_t(pack_buf, ofset);
    *(uint16_t *)(pack_buf+ofset) = crc;
    ofset += 2;

    return ofset;
}


 project/socketd/booster/packet.h

@@ -18,18 +18,18 @@
#include <stdint.h>
#include <time.h>

#define DEVID_LEN          16
#define DEVID_LEN          8
#define TIME_LEN           32

typedef struct pack_info_s
{
    char          devid[DEVID_LEN];  /* device ID  */
    char          devid[DEVID_LEN+1];  /* device ID  */
    struct tm     sample_time;       /* sample time  */
    float         temper;            /* sample temperature */
} pack_info_t;

/* packet function pointer type */
typedef int (* pack_proc_t)(pack_info_t *pack_info, char *pack_buf, int size);
typedef int (* pack_proc_t)(pack_info_t *pack_info, uint8_t *pack_buf, int size);

/*  description: get device ID
 *   input args:
@@ -54,7 +54,7 @@
 *               $size     :  packet output buffer size
 * return value: <0: failure   >0: packet bytes
 */
extern int packet_segmented_pack(pack_info_t *pack_info, char *pack_buf, int size);
extern int packet_segmented_pack(pack_info_t *pack_info, uint8_t *pack_buf, int size);


/*  description: package a json string packet: {"devid":"xxx", "time":"xxx", "temperature":"xxx"}
@@ -64,7 +64,44 @@
 *               $size     :  packet output buffer size
 * return value: <0: failure   >0: packet bytes
 */
extern int packet_json_pack(pack_info_t *pack_info, char *pack_buf, int size);
extern int packet_json_pack(pack_info_t *pack_info, uint8_t *pack_buf, int size);


/* TLV(Tag Length Value) PDU(Protocal Data Unit) format:
 *
 * +-----------+-----------+------------+-------------+-------------+
 * | Header(2B)|  Tag(1B)  | Length(2B) |  Value(nB)  |  CRC16(2B)  |
 * +-----------+-----------+------------+-------------+-------------+
 *
 * Header(2B): 0xFE 0xED
 *    Tag(1B): 0x01->temperature 0x02->Humidity 0x03->Noisy ...
 * Length(2B): Data length
 *  Value(nB): Data value
 *  CRC16(2B): CRC from Header to Value
 */

/* TLV Header */
#define TLV_HEADER          0xFEED

/* TLV bytes without payload: Header(2B)+Tag(1B)+Length(2B)+CRC16(2B) */
#define TLV_MINSIZE         7

/* TVL Tag definition */
enum
{
    TAG_TEMPERATURE = 1,
    TAG_HUMIDITY,
    TAG_NOISY,
};

/*  description: package a TLV packet: 0xFD 0xFE
 *   input args:
 *               $pack_info:  packet data contains devid, time and temperature
 *               $pack_buf :  packet output buffer
 *               $size     :  packet output buffer size
 * return value: <0: failure   >0: packet bytes
 */

int packet_tlv_pack(pack_info_t *pack_info, uint8_t *pack_buf, int size);

#endif   /* ----- #ifndef _PACKET_H_  ----- */

 project/socketd/sock_client.c

@@ -166,10 +166,12 @@
            }
            log_info("DS18B20 sample termperature %.3f oC\n", pack_info.temper);

            get_devid(pack_info.devid, DEVID_LEN, 40);
            get_devid(pack_info.devid, sizeof(pack_info.devid), 88);
            get_time(&pack_info.sample_time);

            pack_bytes = pack_proc(&pack_info, pack_buf, sizeof(pack_buf));
            pack_bytes = pack_proc(&pack_info, (uint8_t *)pack_buf, sizeof(pack_buf));
            log_dump(LOG_LEVEL_DEBUG, NULL, pack_buf, pack_bytes);

            sample_flag = 1; /* set sample flag */
        }