Question: Does libCSP add any header or bits AFTER the message?

[hernaangq]

Good morning,

I am sending CSP messages from a node to another one via CAN and printing them. I can see there are some bits after the message, is this how it is suppose to work? The message I am sending is just the word "hello".

[moonlight83340]

Hi, what version and option are you using ?

[hernaangq]

Hello, The client is using 1.4 and server 1.6. what options do you mean?

[moonlight83340]

Sorry, I meant what flag are you using ? RDP, CRC32 for example.

[hernaangq]

/ WARNING! All changes made to this file will be lost! /

ifndef W_INCLUDE_CSP_CSP_AUTOCONFIG_H_WAF

define W_INCLUDE_CSP_CSP_AUTOCONFIG_H_WAF

define GIT_REV "7d03adb"

define CSP_FREERTOS 1

/ #undef CSP_POSIX / / #undef CSP_WINDOWS / / #undef CSP_MACOSX /

define CSP_DEBUG 1

define CSP_DEBUG_TIMESTAMP 0

define CSP_USE_RDP 1

define CSP_USE_RDP_FAST_CLOSE 0

define CSP_USE_CRC32 1

define CSP_USE_HMAC 0

define CSP_USE_XTEA 0

define CSP_USE_PROMISC 0

define CSP_USE_QOS 0

define CSP_USE_DEDUP 0

define CSP_USE_EXTERNAL_DEBUG 1

define CSP_LOG_LEVEL_DEBUG 1

define CSP_LOG_LEVEL_INFO 1

define CSP_LOG_LEVEL_WARN 1

define CSP_LOG_LEVEL_ERROR 1

/ #undef CSP_LITTLE_ENDIAN /

define CSP_BIG_ENDIAN 1

define LIBCSP_VERSION "1.6"

endif / W_INCLUDE_CSP_CSP_AUTOCONFIG_H_WAF /

I am using those in the client side.

[moonlight83340]

Sorry again, I meant thoses flags : https://github.com/libcsp/libcsp/blob/447cc38f2106a15290358dc8c128ad553a415568/examples/csp_client.c#L252

In csp_connect()``

[hernaangq]

no problem, thanks for taking the time to answer my question.

In the client side:

csp_conn_t * conn = csp_connect(CSP_PRIO_NORM, node, 5, 0, 0);

In the server side:

    csp_conn_t *conn;
    csp_packet_t *packet;
    csp_socket_t *sock = csp_socket(CSP_DEFAULT_CONNECTION_OPTIONS);

    if (sock == NULL)
    {
        debug_printf_safe(ERROR, "CSP SOCKET CREATION ERROR");
    }

    int error1 = csp_bind(sock, 5);
    if (error1 != CSP_ERR_NONE)
    {
        debug_printf_safe(ERROR, "CSP BIND ERROR");
    }

    int error2 = csp_listen(sock, CSP_NUM_BACKLOG_QUEUES);
    if (error2 != CSP_ERR_NONE)
    {
        debug_printf_safe(ERROR, "CSP LISTEN ERROR");
    }

    while (1)
    {

        conn = csp_accept(sock, 10000);

        if (conn == NULL)
        {
            continue;
        }

        while ((packet = csp_read(conn, 0)) != NULL)
        {
            if (packet == NULL)
                break;

            debug_printf_safe(INFO, "CSP PACKET RECEIVED");
            csp_buffer_free(packet);
        }

        csp_close(conn);

    }

[hernaangq]

this might help, Now I am sending "hello cube" and with a CAN byte reader I am getting the following results:

[yashi]

B9 E8 96 4C must be the CRC32. See https://crccalc.com/?crc=hello%20cube&method=CRC-32C&datatype=ascii&outtype=0

[hernaangq]

thank you so much, that was my first thought. I guess csp_read is the function that get rid of this CRC right?

[moonlight83340]

thank you so much, that was my first thought. I guess csp_read is the function that get rid of this CRC right?

In fact CRC is strip on the security check : https://github.com/libcsp/libcsp/blob/v1.4/src/csp_crc32.c#L124 https://github.com/libcsp/libcsp/blob/v1.4/src/csp_route.c#L89C7-L89C23 https://github.com/libcsp/libcsp/blob/v1.4/src/csp_route.c#L129C5-L129C19 It's done when a packet is received on the route.

[hernaangq]

    while (1)
    {

        conn = csp_accept(sock, 10000);

        if (conn == NULL)
        {
            continue;
        }

        while ((packet = csp_read(conn, 0)) != NULL)
        {
            if (packet == NULL)
                break;

            debug_printf_safe(INFO, "CSP PACKET RECEIVED");
            csp_buffer_free(packet);
        }

        csp_close(conn);

    }

So this code should strip de CRC automatically or should I add any code?

[moonlight83340]

    while (1)
    {

        conn = csp_accept(sock, 10000);

        if (conn == NULL)
        {
            continue;
        }

        while ((packet = csp_read(conn, 0)) != NULL)
        {
            if (packet == NULL)
                break;

            debug_printf_safe(INFO, "CSP PACKET RECEIVED");
            csp_buffer_free(packet);
        }

        csp_close(conn);

    }

So this code should strip de CRC automatically or should I add any code?

I'm curious about your client code, if you don't mind ? I think you should use CRC32 option flag to be automatically strip.

[hernaangq]

/* Prepare data */
    csp_packet_t * packet = csp_buffer_get(5);
    if (packet == NULL)
        return;

    /* Open connection */
    csp_conn_t * conn = csp_connect(CSP_PRIO_NORM, node, 5, 0, 0);
    if (conn == NULL) {
        csp_buffer_free(packet);
        return;
    }

    //packet->data[0] = 0x77;
    //packet->data[1] = 0x6F;
    //packet->data[2] = 0x72;
    //packet->data[3] = 0x6c;
    //packet->data[4] = 0x64;

    packet->data[0] = 0x68;
    packet->data[1] = 0x65;
    packet->data[2] = 0x6c;
    packet->data[3] = 0x6c;
    packet->data[4] = 0x6f;
    packet->data[5] = 0x20;
    packet->data[6] = 0x63;
    packet->data[7] = 0x75;
    packet->data[8] = 0x62;
    packet->data[9] = 0x65;

    packet->length = 10;

    //printf(" %u.\r\n", packet->data);
    printf("Sending: %s\n", (char *)packet->data);

    /* Try to send frame */
    if (!csp_send(conn, packet, 0))
        csp_buffer_free(packet);

    csp_close(conn);

Here you have it, how do I add that CRC32 option flag to be automatically strip?

[moonlight83340]

/* Prepare data */
  csp_packet_t * packet = csp_buffer_get(5);
  if (packet == NULL)
      return;

  /* Open connection */
  csp_conn_t * conn = csp_connect(CSP_PRIO_NORM, node, 5, 0, 0);
  if (conn == NULL) {
      csp_buffer_free(packet);
      return;
  }

  //packet->data[0] = 0x77;
  //packet->data[1] = 0x6F;
  //packet->data[2] = 0x72;
  //packet->data[3] = 0x6c;
  //packet->data[4] = 0x64;

  packet->data[0] = 0x68;
  packet->data[1] = 0x65;
  packet->data[2] = 0x6c;
  packet->data[3] = 0x6c;
  packet->data[4] = 0x6f;
  packet->data[5] = 0x20;
  packet->data[6] = 0x63;
  packet->data[7] = 0x75;
  packet->data[8] = 0x62;
  packet->data[9] = 0x65;

  packet->length = 10;

  //printf(" %u.\r\n", packet->data);
  printf("Sending: %s\n", (char *)packet->data);

  /* Try to send frame */
  if (!csp_send(conn, packet, 0))
      csp_buffer_free(packet);

  csp_close(conn);

Here you have it, how do I add that CRC32 option flag to be automatically strip?

Use this flag : CSP_O_CRC32 https://github.com/libcsp/libcsp/blob/v1.4/include/csp/csp_types.h#L159 csp_conn_t * conn = csp_connect(CSP_PRIO_NORM, node, 5, 0, CSP_O_CRC32);

[hernaangq]

@moonlight83340 Thank you so much, that was it.