<NME> unit-test-client.c
<BEF> /*
 * Copyright © Stéphane Raimbault <stephane.raimbault@gmail.com>
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include <errno.h>
#include <modbus.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "unit-test.h"

const int EXCEPTION_RC = 2;

enum {
    TCP,
    TCP_PI,
    RTU
};

int test_server(modbus_t *ctx, int use_backend);
int send_crafted_request(modbus_t *ctx,
                         int function,
                         uint8_t *req,
                         int req_size,
                         uint16_t max_value,
                         uint16_t bytes,
                         int backend_length,
                         int backend_offset);
int equal_dword(uint16_t *tab_reg, const uint32_t value);
int is_memory_equal(const void *s1, const void *s2, size_t size);

#define BUG_REPORT(_cond, _format, _args...) \
  printf("\nLine %d: assertion error for '%s': " _format "\n", __LINE__, #_cond, ##_args)

#define ASSERT_TRUE(_cond, _format, __args...) \
  {                                            \
    if (_cond) {                               \
      printf("OK\n");                          \
    } else {                                   \
      BUG_REPORT(_cond, _format, ##__args);    \
      goto close;                              \
    }                                          \
  };

int is_memory_equal(const void *s1, const void *s2, size_t size)
{
    return (memcmp(s1, s2, size) == 0);
}

int equal_dword(uint16_t *tab_reg, const uint32_t value)
{
    return ((tab_reg[0] == (value >> 16)) && (tab_reg[1] == (value & 0xFFFF)));
}

int main(int argc, char *argv[])
{
    const int NB_REPORT_SLAVE_ID = 10;
    uint8_t *tab_rp_bits = NULL;
    uint16_t *tab_rp_registers = NULL;
    uint16_t *tab_rp_registers_bad = NULL;
    modbus_t *ctx = NULL;
    int i;
    uint8_t value;
    int nb_points;
    int rc;
    float real;
    uint32_t old_response_to_sec;
    uint32_t old_response_to_usec;
    uint32_t new_response_to_sec;
    uint32_t new_response_to_usec;
    uint32_t old_byte_to_sec;
    uint32_t old_byte_to_usec;
    int use_backend;
    int success = FALSE;
    int old_slave;

    if (argc > 1) {
        if (strcmp(argv[1], "tcp") == 0) {
            use_backend = TCP;
        } else if (strcmp(argv[1], "tcppi") == 0) {
            use_backend = TCP_PI;
        } else if (strcmp(argv[1], "rtu") == 0) {
            use_backend = RTU;
        } else {
            printf("Usage:\n  %s [tcp|tcppi|rtu] - Modbus client for unit testing\n\n",
                   argv[0]);
            exit(1);
        }
    } else {
        /* By default */
        use_backend = TCP;
    }

    if (use_backend == TCP) {
        ctx = modbus_new_tcp("127.0.0.1", 1502);
    } else if (use_backend == TCP_PI) {
        ctx = modbus_new_tcp_pi("::1", "1502");
    } else {
        ctx = modbus_new_rtu("/dev/ttyUSB1", 115200, 'N', 8, 1);
    }
    if (ctx == NULL) {
        fprintf(stderr, "Unable to allocate libmodbus context\n");
        return -1;
    }
    modbus_set_debug(ctx, TRUE);
    modbus_set_error_recovery(
        ctx, MODBUS_ERROR_RECOVERY_LINK | MODBUS_ERROR_RECOVERY_PROTOCOL);

    if (use_backend == RTU) {
        modbus_set_slave(ctx, SERVER_ID);
    }

    modbus_get_response_timeout(ctx, &old_response_to_sec, &old_response_to_usec);
    if (modbus_connect(ctx) == -1) {
        fprintf(stderr, "Connection failed: %s\n", modbus_strerror(errno));
        modbus_free(ctx);
        return -1;
    }

    /* Allocate and initialize the memory to store the bits */
    nb_points = (UT_BITS_NB > UT_INPUT_BITS_NB) ? UT_BITS_NB : UT_INPUT_BITS_NB;
    tab_rp_bits = (uint8_t *) malloc(nb_points * sizeof(uint8_t));
    memset(tab_rp_bits, 0, nb_points * sizeof(uint8_t));

    /* Allocate and initialize the memory to store the registers */
    nb_points = (UT_REGISTERS_NB > UT_INPUT_REGISTERS_NB) ? UT_REGISTERS_NB
                                                          : UT_INPUT_REGISTERS_NB;
    tab_rp_registers = (uint16_t *) malloc(nb_points * sizeof(uint16_t));
    memset(tab_rp_registers, 0, nb_points * sizeof(uint16_t));

    printf("** UNIT TESTING **\n");

    printf("1/1 No response timeout modification on connect: ");
    modbus_get_response_timeout(ctx, &new_response_to_sec, &new_response_to_usec);
    ASSERT_TRUE(old_response_to_sec == new_response_to_sec &&
                    old_response_to_usec == new_response_to_usec,
                "");

    printf("\nTEST WRITE/READ:\n");

    /** COIL BITS **/

    /* Single */
    rc = modbus_write_bit(ctx, UT_BITS_ADDRESS, ON);
    printf("1/2 modbus_write_bit: ");
    ASSERT_TRUE(rc == 1, "");

    rc = modbus_read_bits(ctx, UT_BITS_ADDRESS, 1, tab_rp_bits);
    printf("2/2 modbus_read_bits: ");
    ASSERT_TRUE(rc == 1, "FAILED (nb points %d)\n", rc);
    ASSERT_TRUE(tab_rp_bits[0] == ON, "FAILED (%0X != %0X)\n", tab_rp_bits[0], ON);

    /* End single */

    /* Multiple bits */
    {
        uint8_t tab_value[UT_BITS_NB];

        modbus_set_bits_from_bytes(tab_value, 0, UT_BITS_NB, UT_BITS_TAB);
        rc = modbus_write_bits(ctx, UT_BITS_ADDRESS, UT_BITS_NB, tab_value);
        printf("1/2 modbus_write_bits: ");
        ASSERT_TRUE(rc == UT_BITS_NB, "");
    }

    rc = modbus_read_bits(ctx, UT_BITS_ADDRESS, UT_BITS_NB, tab_rp_bits);
    printf("2/2 modbus_read_bits: ");
    ASSERT_TRUE(rc == UT_BITS_NB, "FAILED (nb points %d)\n", rc);

    i = 0;
    nb_points = UT_BITS_NB;
    while (nb_points > 0) {
        int nb_bits = (nb_points > 8) ? 8 : nb_points;

        value = modbus_get_byte_from_bits(tab_rp_bits, i * 8, nb_bits);
        ASSERT_TRUE(
            value == UT_BITS_TAB[i], "FAILED (%0X != %0X)\n", value, UT_BITS_TAB[i]);

        nb_points -= nb_bits;
        i++;
    }
    printf("OK\n");
    /* End of multiple bits */

    /** DISCRETE INPUTS **/
    rc =
        modbus_read_input_bits(ctx, UT_INPUT_BITS_ADDRESS, UT_INPUT_BITS_NB, tab_rp_bits);
    printf("1/1 modbus_read_input_bits: ");
    ASSERT_TRUE(rc == UT_INPUT_BITS_NB, "FAILED (nb points %d)\n", rc);

    i = 0;
    nb_points = UT_INPUT_BITS_NB;
    while (nb_points > 0) {
        int nb_bits = (nb_points > 8) ? 8 : nb_points;
        value = modbus_get_byte_from_bits(tab_rp_bits, i * 8, nb_bits);
        ASSERT_TRUE(value == UT_INPUT_BITS_TAB[i],
                    "FAILED (%0X != %0X)\n",
                    value,
                    UT_INPUT_BITS_TAB[i]);

        nb_points -= nb_bits;
        i++;
    }
    printf("OK\n");

    /** HOLDING REGISTERS **/

    /* Single register */
    rc = modbus_write_register(ctx, UT_REGISTERS_ADDRESS, 0x1234);
    printf("1/2 modbus_write_register: ");
    ASSERT_TRUE(rc == 1, "");

    rc = modbus_read_registers(ctx, UT_REGISTERS_ADDRESS, 1, tab_rp_registers);
    printf("2/2 modbus_read_registers: ");
    ASSERT_TRUE(rc == 1, "FAILED (nb points %d)\n", rc);
    ASSERT_TRUE(tab_rp_registers[0] == 0x1234,
                "FAILED (%0X != %0X)\n",
                tab_rp_registers[0],
                0x1234);
    /* End of single register */

    /* Many registers */
    rc = modbus_write_registers(
        ctx, UT_REGISTERS_ADDRESS, UT_REGISTERS_NB, UT_REGISTERS_TAB);
    printf("1/5 modbus_write_registers: ");
    ASSERT_TRUE(rc == UT_REGISTERS_NB, "");

    rc = modbus_read_registers(
        ctx, UT_REGISTERS_ADDRESS, UT_REGISTERS_NB, tab_rp_registers);
    printf("2/5 modbus_read_registers: ");
    ASSERT_TRUE(rc == UT_REGISTERS_NB, "FAILED (nb points %d)\n", rc);

    for (i = 0; i < UT_REGISTERS_NB; i++) {
        ASSERT_TRUE(tab_rp_registers[i] == UT_REGISTERS_TAB[i],
                    "FAILED (%0X != %0X)\n",
                    tab_rp_registers[i],
                    UT_REGISTERS_TAB[i]);
    }

    rc = modbus_read_registers(ctx, UT_REGISTERS_ADDRESS, 0, tab_rp_registers);
    printf("3/5 modbus_read_registers (0): ");
    ASSERT_TRUE(rc == -1, "FAILED (nb_points %d)\n", rc);

    nb_points = (UT_REGISTERS_NB > UT_INPUT_REGISTERS_NB) ? UT_REGISTERS_NB
                                                          : UT_INPUT_REGISTERS_NB;
    memset(tab_rp_registers, 0, nb_points * sizeof(uint16_t));

    /* Write registers to zero from tab_rp_registers and store read registers
       into tab_rp_registers. So the read registers must set to 0, except the
       first one because there is an offset of 1 register on write. */
    rc = modbus_write_and_read_registers(ctx,
                                         UT_REGISTERS_ADDRESS + 1,
                                         UT_REGISTERS_NB - 1,
                                         tab_rp_registers,
                                         UT_REGISTERS_ADDRESS,
                                         UT_REGISTERS_NB,
                                         tab_rp_registers);
    printf("4/5 modbus_write_and_read_registers: ");
    ASSERT_TRUE(
        rc == UT_REGISTERS_NB, "FAILED (nb points %d != %d)\n", rc, UT_REGISTERS_NB);

    ASSERT_TRUE(tab_rp_registers[0] == UT_REGISTERS_TAB[0],
                "FAILED (%0X != %0X)\n",
                tab_rp_registers[0],
                UT_REGISTERS_TAB[0]);

    for (i = 1; i < UT_REGISTERS_NB; i++) {
        ASSERT_TRUE(
            tab_rp_registers[i] == 0, "FAILED (%0X != %0X)\n", tab_rp_registers[i], 0);
    }

    /* End of many registers */

    /** INPUT REGISTERS **/
    rc = modbus_read_input_registers(
        ctx, UT_INPUT_REGISTERS_ADDRESS, UT_INPUT_REGISTERS_NB, tab_rp_registers);
    printf("1/1 modbus_read_input_registers: ");
    ASSERT_TRUE(rc == UT_INPUT_REGISTERS_NB, "FAILED (nb points %d)\n", rc);

    for (i = 0; i < UT_INPUT_REGISTERS_NB; i++) {
        ASSERT_TRUE(tab_rp_registers[i] == UT_INPUT_REGISTERS_TAB[i],
                    "FAILED (%0X != %0X)\n",
                    tab_rp_registers[i],
                    UT_INPUT_REGISTERS_TAB[i]);
    }

    /* MASKS */
    printf("1/1 Write mask: ");
    rc = modbus_write_register(ctx, UT_REGISTERS_ADDRESS, 0x12);
    rc = modbus_mask_write_register(ctx, UT_REGISTERS_ADDRESS, 0xF2, 0x25);
    ASSERT_TRUE(rc != -1, "FAILED (%x == -1)\n", rc);
    rc = modbus_read_registers(ctx, UT_REGISTERS_ADDRESS, 1, tab_rp_registers);
    ASSERT_TRUE(
        tab_rp_registers[0] == 0x17, "FAILED (%0X != %0X)\n", tab_rp_registers[0], 0x17);

    printf("\nTEST FLOATS\n");
    /** FLOAT **/
    printf("1/4 Set/get float ABCD: ");
    modbus_set_float_abcd(UT_REAL, tab_rp_registers);
    ASSERT_TRUE(is_memory_equal(tab_rp_registers, UT_IREAL_ABCD_SET, 4),
                "FAILED Set float ABCD");
    real = modbus_get_float_abcd(UT_IREAL_ABCD_GET);
    ASSERT_TRUE(real == UT_REAL, "FAILED (%f != %f)\n", real, UT_REAL);

    printf("2/4 Set/get float DCBA: ");
    modbus_set_float_dcba(UT_REAL, tab_rp_registers);
    ASSERT_TRUE(is_memory_equal(tab_rp_registers, UT_IREAL_DCBA_SET, 4),
                "FAILED Set float DCBA");
    real = modbus_get_float_dcba(UT_IREAL_DCBA_GET);
    ASSERT_TRUE(real == UT_REAL, "FAILED (%f != %f)\n", real, UT_REAL);

    printf("3/4 Set/get float BADC: ");
    modbus_set_float_badc(UT_REAL, tab_rp_registers);
    ASSERT_TRUE(is_memory_equal(tab_rp_registers, UT_IREAL_BADC_SET, 4),
                "FAILED Set float BADC");
    real = modbus_get_float_badc(UT_IREAL_BADC_GET);
    ASSERT_TRUE(real == UT_REAL, "FAILED (%f != %f)\n", real, UT_REAL);

    printf("4/4 Set/get float CDAB: ");
    modbus_set_float_cdab(UT_REAL, tab_rp_registers);
    ASSERT_TRUE(is_memory_equal(tab_rp_registers, UT_IREAL_CDAB_SET, 4),
                "FAILED Set float CDAB");
    real = modbus_get_float_cdab(UT_IREAL_CDAB_GET);
    ASSERT_TRUE(real == UT_REAL, "FAILED (%f != %f)\n", real, UT_REAL);

    printf("\nAt this point, error messages doesn't mean the test has failed\n");

    /** ILLEGAL DATA ADDRESS **/
    printf("\nTEST ILLEGAL DATA ADDRESS:\n");

    /* The mapping begins at the defined addresses and ends at address +
     * nb_points so these addresses are not valid. */

    rc = modbus_read_bits(ctx, 0, 1, tab_rp_bits);
    printf("* modbus_read_bits (0): ");
    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");

    rc = modbus_read_bits(ctx, UT_BITS_ADDRESS, UT_BITS_NB + 1, tab_rp_bits);
    printf("* modbus_read_bits (max): ");
    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");

    rc = modbus_read_input_bits(ctx, 0, 1, tab_rp_bits);
    printf("* modbus_read_input_bits (0): ");
    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");

    rc = modbus_read_input_bits(
        ctx, UT_INPUT_BITS_ADDRESS, UT_INPUT_BITS_NB + 1, tab_rp_bits);
    printf("* modbus_read_input_bits (max): ");
    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");

    rc = modbus_read_registers(ctx, 0, 1, tab_rp_registers);
    printf("* modbus_read_registers (0): ");
    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");

    rc = modbus_read_registers(
        ctx, UT_REGISTERS_ADDRESS, UT_REGISTERS_NB_MAX + 1, tab_rp_registers);
    printf("* modbus_read_registers (max): ");
    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");

    rc = modbus_read_input_registers(ctx, 0, 1, tab_rp_registers);
    printf("* modbus_read_input_registers (0): ");
    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");

    rc = modbus_read_input_registers(
        ctx, UT_INPUT_REGISTERS_ADDRESS, UT_INPUT_REGISTERS_NB + 1, tab_rp_registers);
    printf("* modbus_read_input_registers (max): ");
    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");

    /** TOO MANY DATA **/
    printf("\nTEST TOO MANY DATA ERROR:\n");

    rc = modbus_read_bits(ctx, UT_BITS_ADDRESS, MODBUS_MAX_BITS + 1,
                          tab_rp_bits);
    printf("* modbus_read_bits: ");
    if (rc == -1 && errno == EMBMDATA) {

    rc = modbus_write_bits(ctx, 0, 1, tab_rp_bits);
    printf("* modbus_write_coils (0): ");
    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");
    }

    rc = modbus_read_input_bits(ctx, UT_INPUT_BITS_ADDRESS,
                                MODBUS_MAX_BITS + 1,
                                tab_rp_bits);
    printf("* modbus_read_input_bits: ");
    if (rc == -1 && errno == EMBMDATA) {
    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");

    rc = modbus_write_register(
        ctx, UT_REGISTERS_ADDRESS + UT_REGISTERS_NB_MAX, tab_rp_registers[0]);
    }

    rc = modbus_read_registers(ctx, UT_REGISTERS_ADDRESS,
                               MODBUS_MAX_REGISTERS + 1,
                               tab_rp_registers);
    printf("* modbus_read_registers: ");
    if (rc == -1 && errno == EMBMDATA) {
    rc = modbus_write_registers(ctx,
                                UT_REGISTERS_ADDRESS + UT_REGISTERS_NB_MAX,
                                UT_REGISTERS_NB,
                                tab_rp_registers);
    }

    rc = modbus_read_input_registers(ctx, UT_INPUT_REGISTERS_ADDRESS,
                                     MODBUS_MAX_REGISTERS + 1,
                                     tab_rp_registers);
    printf("* modbus_read_input_registers: ");
    if (rc == -1 && errno == EMBMDATA) {
    rc = modbus_mask_write_register(
        ctx, UT_REGISTERS_ADDRESS + UT_REGISTERS_NB_MAX, 0xF2, 0x25);
    printf("* modbus_mask_write_registers (max): ");
    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");
    }

    rc = modbus_write_bits(ctx, UT_BITS_ADDRESS,
                           MODBUS_MAX_BITS + 1,
                           tab_rp_bits);
    printf("* modbus_write_bits: ");
    if (rc == -1 && errno == EMBMDATA) {
                                         UT_REGISTERS_ADDRESS + UT_REGISTERS_NB_MAX,
                                         UT_REGISTERS_NB,
                                         tab_rp_registers,
                                         UT_REGISTERS_ADDRESS + UT_REGISTERS_NB_MAX,
    }

    rc = modbus_write_registers(ctx, UT_REGISTERS_ADDRESS,
                                MODBUS_MAX_REGISTERS + 1,
                                tab_rp_registers);
    printf("* modbus_write_registers: ");
    if (rc == -1 && errno == EMBMDATA) {

    rc = modbus_read_bits(ctx, UT_BITS_ADDRESS, MODBUS_MAX_READ_BITS + 1, tab_rp_bits);
    printf("* modbus_read_bits: ");
    ASSERT_TRUE(rc == -1 && errno == EMBMDATA, "");

    rc = modbus_read_input_bits(
        ctx, UT_INPUT_BITS_ADDRESS, MODBUS_MAX_READ_BITS + 1, tab_rp_bits);
    printf("* modbus_read_input_bits: ");
    ASSERT_TRUE(rc == -1 && errno == EMBMDATA, "");

    rc = modbus_read_registers(
        ctx, UT_REGISTERS_ADDRESS, MODBUS_MAX_READ_REGISTERS + 1, tab_rp_registers);
    printf("* modbus_read_registers: ");
    ASSERT_TRUE(rc == -1 && errno == EMBMDATA, "");

    rc = modbus_read_input_registers(
        ctx, UT_INPUT_REGISTERS_ADDRESS, MODBUS_MAX_READ_REGISTERS + 1, tab_rp_registers);
    printf("* modbus_read_input_registers: ");
    ASSERT_TRUE(rc == -1 && errno == EMBMDATA, "");

    rc = modbus_write_bits(ctx, UT_BITS_ADDRESS, MODBUS_MAX_WRITE_BITS + 1, tab_rp_bits);
    printf("* modbus_write_bits: ");
    ASSERT_TRUE(rc == -1 && errno == EMBMDATA, "");

    rc = modbus_write_registers(
        ctx, UT_REGISTERS_ADDRESS, MODBUS_MAX_WRITE_REGISTERS + 1, tab_rp_registers);
    printf("* modbus_write_registers: ");
    ASSERT_TRUE(rc == -1 && errno == EMBMDATA, "");

    /** SLAVE ADDRESS **/
    old_slave = modbus_get_slave(ctx);

    printf("\nTEST SLAVE ADDRESS:\n");

    printf("1/2 Not compliant slave address is refused: ");
    rc = modbus_set_slave(ctx, 248);
    ASSERT_TRUE(rc == -1, "Slave address of 248 shouldn't be allowed");

    printf("2/2 Not compliant slave address is allowed: ");
    modbus_enable_quirks(ctx, MODBUS_QUIRK_MAX_SLAVE);
    rc = modbus_set_slave(ctx, 248);
    ASSERT_TRUE(rc == 0, "Not compliant slave address should have been accepted");

    modbus_disable_quirks(ctx, MODBUS_QUIRK_MAX_SLAVE);
    rc = modbus_set_slave(ctx, old_slave);
    ASSERT_TRUE(rc == 0, "Uanble to restore slave value")

    /** SLAVE REPLY **/

    printf("\nTEST SLAVE REPLY:\n");
    modbus_set_slave(ctx, INVALID_SERVER_ID);
    rc = modbus_read_registers(
        ctx, UT_REGISTERS_ADDRESS, UT_REGISTERS_NB, tab_rp_registers);
    if (use_backend == RTU) {
        const int RAW_REQ_LENGTH = 6;
        uint8_t raw_req[] = {INVALID_SERVER_ID, 0x03, 0x00, 0x01, 0x01, 0x01};
        /* Too many points */
        uint8_t raw_invalid_req[] = {INVALID_SERVER_ID, 0x03, 0x00, 0x01, 0xFF, 0xFF};
        const int RAW_RSP_LENGTH = 7;
        uint8_t raw_rsp[] = {INVALID_SERVER_ID, 0x03, 0x04, 0, 0, 0, 0};
        uint8_t rsp[MODBUS_RTU_MAX_ADU_LENGTH];

        /* No response in RTU mode */
        printf("1-A/3 No response from slave %d: ", INVALID_SERVER_ID);
        ASSERT_TRUE(rc == -1 && errno == ETIMEDOUT, "");

        /* The slave raises a timeout on a confirmation to ignore because if an
         * indication for another slave is received, a confirmation must follow */

        /* Send a pair of indication/confirmation to the slave with a different
         * slave ID to simulate a communication on a RS485 bus. At first, the
         * slave will see the indication message then the confirmation, and it must
         * ignore both. */
        modbus_send_raw_request(ctx, raw_req, RAW_REQ_LENGTH * sizeof(uint8_t));
        modbus_send_raw_request(ctx, raw_rsp, RAW_RSP_LENGTH * sizeof(uint8_t));
        rc = modbus_receive_confirmation(ctx, rsp);

        printf("1-B/3 No response from slave %d on indication/confirmation messages: ",
               INVALID_SERVER_ID);
        ASSERT_TRUE(rc == -1 && errno == ETIMEDOUT, "");

        /* Send an INVALID request for another slave */
        modbus_send_raw_request(ctx, raw_invalid_req, RAW_REQ_LENGTH * sizeof(uint8_t));
        rc = modbus_receive_confirmation(ctx, rsp);

        printf("1-C/3 No response from slave %d with invalid request: ",
               INVALID_SERVER_ID);
        ASSERT_TRUE(rc == -1 && errno == ETIMEDOUT, "");

        rc = modbus_set_slave(ctx, MODBUS_BROADCAST_ADDRESS);
        ASSERT_TRUE(rc == 0, "Invalid broadcast address");

        rc = modbus_read_registers(
            ctx, UT_REGISTERS_ADDRESS, UT_REGISTERS_NB, tab_rp_registers);
        printf("2/3 No reply after a broadcast query: ");
        ASSERT_TRUE(rc == -1 && errno == ETIMEDOUT, "");
    } else {
        /* Response in TCP mode */
        printf("1/3 Response from slave %d: ", INVALID_SERVER_ID);
        ASSERT_TRUE(rc == UT_REGISTERS_NB, "");

        rc = modbus_set_slave(ctx, MODBUS_BROADCAST_ADDRESS);
        ASSERT_TRUE(rc == 0, "Invalid broacast address");

        rc = modbus_read_registers(
            ctx, UT_REGISTERS_ADDRESS, UT_REGISTERS_NB, tab_rp_registers);
        printf("2/3 Reply after a query with unit id == 0: ");
        ASSERT_TRUE(rc == UT_REGISTERS_NB, "");
    }

    /* Restore slave */
    modbus_set_slave(ctx, old_slave);

    printf("3/3 Response with an invalid TID or slave: ");
    rc = modbus_read_registers(
        ctx, UT_REGISTERS_ADDRESS_INVALID_TID_OR_SLAVE, 1, tab_rp_registers);
    ASSERT_TRUE(rc == -1, "");

    printf("1/2 Report slave ID truncated: \n");
    /* Set a marker to ensure limit is respected */
    tab_rp_bits[NB_REPORT_SLAVE_ID - 1] = 42;
    rc = modbus_report_slave_id(ctx, NB_REPORT_SLAVE_ID - 1, tab_rp_bits);
    /* Return the size required (response size) but respects the defined limit */
    ASSERT_TRUE(rc == NB_REPORT_SLAVE_ID && tab_rp_bits[NB_REPORT_SLAVE_ID - 1] == 42,
                "Return is rc %d (%d) and marker is %d (42)",
                rc,
                NB_REPORT_SLAVE_ID,
                tab_rp_bits[NB_REPORT_SLAVE_ID - 1]);

    printf("2/2 Report slave ID: \n");
    /* tab_rp_bits is used to store bytes */
    rc = modbus_report_slave_id(ctx, NB_REPORT_SLAVE_ID, tab_rp_bits);
    ASSERT_TRUE(rc == NB_REPORT_SLAVE_ID, "");

    /* Slave ID is an arbitrary number for libmodbus */
    ASSERT_TRUE(rc > 0, "");

    /* Run status indicator is ON */
    ASSERT_TRUE(rc > 1 && tab_rp_bits[1] == 0xFF, "");

    /* Print additional data as string */
    if (rc > 2) {
        printf("Additional data: ");
        for (i = 2; i < rc; i++) {
            printf("%c", tab_rp_bits[i]);
        }
        printf("\n");
    }

    /* Save original timeout */
    modbus_get_response_timeout(ctx, &old_response_to_sec, &old_response_to_usec);
    modbus_get_byte_timeout(ctx, &old_byte_to_sec, &old_byte_to_usec);

    rc = modbus_set_response_timeout(ctx, 0, 0);
    printf("1/6 Invalid response timeout (zero): ");
    ASSERT_TRUE(rc == -1 && errno == EINVAL, "");

    rc = modbus_set_response_timeout(ctx, 0, 1000000);
    printf("2/6 Invalid response timeout (too large us): ");
    ASSERT_TRUE(rc == -1 && errno == EINVAL, "");

    rc = modbus_set_byte_timeout(ctx, 0, 1000000);
    printf("3/6 Invalid byte timeout (too large us): ");
    ASSERT_TRUE(rc == -1 && errno == EINVAL, "");

    modbus_set_response_timeout(ctx, 0, 1);
    rc = modbus_read_registers(
        ctx, UT_REGISTERS_ADDRESS, UT_REGISTERS_NB, tab_rp_registers);
    printf("4/6 1us response timeout: ");
    if (rc == -1 && errno == ETIMEDOUT) {
        printf("OK\n");
    } else {
        printf("FAILED (can fail on some platforms)\n");
    }

    /* A wait and flush operation is done by the error recovery code of
     * libmodbus but after a sleep of current response timeout
     * so 0 can be too short!
     */
    usleep(old_response_to_sec * 1000000 + old_response_to_usec);
    modbus_flush(ctx);

    /* Trigger a special behaviour on server to wait for 0.5 second before
     * replying whereas allowed timeout is 0.2 second */
    modbus_set_response_timeout(ctx, 0, 200000);
    rc = modbus_read_registers(
        ctx, UT_REGISTERS_ADDRESS_SLEEP_500_MS, 1, tab_rp_registers);
    printf("5/6 Too short response timeout (0.2s < 0.5s): ");
    ASSERT_TRUE(rc == -1 && errno == ETIMEDOUT, "");

    /* Wait for reply (0.2 + 0.4 > 0.5 s) and flush before continue */
    usleep(400000);
    modbus_flush(ctx);

    modbus_set_response_timeout(ctx, 0, 600000);
    rc = modbus_read_registers(
        ctx, UT_REGISTERS_ADDRESS_SLEEP_500_MS, 1, tab_rp_registers);
    printf("6/6 Adequate response timeout (0.6s > 0.5s): ");
    ASSERT_TRUE(rc == 1, "");

    /* Disable the byte timeout.
       The full response must be available in the 600ms interval */
    modbus_set_byte_timeout(ctx, 0, 0);
    rc = modbus_read_registers(
        ctx, UT_REGISTERS_ADDRESS_SLEEP_500_MS, 1, tab_rp_registers);
    printf("7/7 Disable byte timeout: ");
    ASSERT_TRUE(rc == 1, "");

    /* Restore original response timeout */
    modbus_set_response_timeout(ctx, old_response_to_sec, old_response_to_usec);

    if (use_backend == TCP) {
        /* The test server is only able to test byte timeouts with the TCP
         * backend */

        /* Timeout of 3ms between bytes */
        modbus_set_byte_timeout(ctx, 0, 3000);
        rc = modbus_read_registers(
            ctx, UT_REGISTERS_ADDRESS_BYTE_SLEEP_5_MS, 1, tab_rp_registers);
        printf("1/2 Too small byte timeout (3ms < 5ms): ");
        ASSERT_TRUE(rc == -1 && errno == ETIMEDOUT, "");

        /* Wait remaining bytes before flushing */
        usleep(11 * 5000);
        modbus_flush(ctx);

        /* Timeout of 7ms between bytes */
        modbus_set_byte_timeout(ctx, 0, 7000);
        rc = modbus_read_registers(
            ctx, UT_REGISTERS_ADDRESS_BYTE_SLEEP_5_MS, 1, tab_rp_registers);
        printf("2/2 Adapted byte timeout (7ms > 5ms): ");
        ASSERT_TRUE(rc == 1, "");
    }

    /* Restore original byte timeout */
    modbus_set_byte_timeout(ctx, old_byte_to_sec, old_byte_to_usec);

    /** BAD RESPONSE **/
    printf("\nTEST BAD RESPONSE ERROR:\n");

    /* Allocate only the required space */
    tab_rp_registers_bad =
        (uint16_t *) malloc(UT_REGISTERS_NB_SPECIAL * sizeof(uint16_t));

    rc = modbus_read_registers(
        ctx, UT_REGISTERS_ADDRESS, UT_REGISTERS_NB_SPECIAL, tab_rp_registers_bad);
    printf("* modbus_read_registers: ");
    ASSERT_TRUE(rc == -1 && errno == EMBBADDATA, "");
    free(tab_rp_registers_bad);

    /** MANUAL EXCEPTION **/
    printf("\nTEST MANUAL EXCEPTION:\n");
    rc = modbus_read_registers(
        ctx, UT_REGISTERS_ADDRESS_SPECIAL, UT_REGISTERS_NB, tab_rp_registers);

    printf("* modbus_read_registers at special address: ");
    ASSERT_TRUE(rc == -1 && errno == EMBXSBUSY, "");

    /** Run a few tests to challenge the server code **/
    if (test_server(ctx, use_backend) == -1) {
        goto close;
    }

    modbus_close(ctx);
    modbus_free(ctx);
    ctx = NULL;

    /* Test init functions */
    printf("\nTEST INVALID INITIALIZATION:\n");
    ctx = modbus_new_rtu(NULL, 1, 'A', 0, 0);
    ASSERT_TRUE(ctx == NULL && errno == EINVAL, "");

    ctx = modbus_new_rtu("/dev/dummy", 0, 'A', 0, 0);
    ASSERT_TRUE(ctx == NULL && errno == EINVAL, "");

    printf("\nALL TESTS PASS WITH SUCCESS.\n");
    success = TRUE;

close:
    /* Free the memory */
    free(tab_rp_bits);
    free(tab_rp_registers);

    /* Close the connection */
    modbus_close(ctx);
    modbus_free(ctx);

    return (success) ? 0 : -1;
}

/* Send crafted requests to test server resilience
   and ensure proper exceptions are returned. */
int test_server(modbus_t *ctx, int use_backend)
{
    int rc;
    int i;
    /* Read requests */
    const int READ_RAW_REQ_LEN = 6;
    const int slave = (use_backend == RTU) ? SERVER_ID : MODBUS_TCP_SLAVE;
    uint8_t read_raw_req[] = {slave,
                              /* function, address, 5 values */
                              MODBUS_FC_READ_HOLDING_REGISTERS,
                              UT_REGISTERS_ADDRESS >> 8,
                              UT_REGISTERS_ADDRESS & 0xFF,
                              0x0,
                              0x05};
    /* Write and read registers request */
    const int RW_RAW_REQ_LEN = 13;
    uint8_t rw_raw_req[] = {slave,
                            /* function, addr to read, nb to read */
                            MODBUS_FC_WRITE_AND_READ_REGISTERS,
                            /* Read */
                            UT_REGISTERS_ADDRESS >> 8,
                            UT_REGISTERS_ADDRESS & 0xFF,
                            (MODBUS_MAX_WR_READ_REGISTERS + 1) >> 8,
                            (MODBUS_MAX_WR_READ_REGISTERS + 1) & 0xFF,
                            /* Write */
                            0,
                            0,
                            0,
                            1,
                            /* Write byte count */
                            1 * 2,
                            /* One data to write... */
                            0x12,
                            0x34};
    const int WRITE_RAW_REQ_LEN = 13;
    uint8_t write_raw_req[] = {slave,
                               /* function will be set in the loop */
                               MODBUS_FC_WRITE_MULTIPLE_REGISTERS,
                               /* Address */
                               UT_REGISTERS_ADDRESS >> 8,
                               UT_REGISTERS_ADDRESS & 0xFF,
                               /* 3 values, 6 bytes */
                               0x00,
                               0x03,
                               0x06,
                               /* Dummy data to write */
                               0x02,
                               0x2B,
                               0x00,
                               0x01,
                               0x00,
                               0x64};
    const int INVALID_FC = 0x42;
    const int INVALID_FC_REQ_LEN = 6;
    uint8_t invalid_fc_raw_req[] = {slave, 0x42, 0x00, 0x00, 0x00, 0x00};

    int req_length;
    uint8_t rsp[MODBUS_TCP_MAX_ADU_LENGTH];
    int tab_read_function[] = {MODBUS_FC_READ_COILS,
                               MODBUS_FC_READ_DISCRETE_INPUTS,
                               MODBUS_FC_READ_HOLDING_REGISTERS,
                               MODBUS_FC_READ_INPUT_REGISTERS};
    int tab_read_nb_max[] = {MODBUS_MAX_READ_BITS + 1,
                             MODBUS_MAX_READ_BITS + 1,
                             MODBUS_MAX_READ_REGISTERS + 1,
                             MODBUS_MAX_READ_REGISTERS + 1};
    int backend_length;
    int backend_offset;

    if (use_backend == RTU) {
        backend_length = 3;
        backend_offset = 1;
    } else {
        backend_length = 7;
        backend_offset = 7;
    }

    printf("\nTEST RAW REQUESTS:\n");

    uint32_t old_response_to_sec;
    uint32_t old_response_to_usec;

    /* This requests can generate flushes server side so we need a higher
     * response timeout than the server. The server uses the defined response
     * timeout to sleep before flushing.
     * The old timeouts are restored at the end.
     */
    modbus_get_response_timeout(ctx, &old_response_to_sec, &old_response_to_usec);
    modbus_set_response_timeout(ctx, 0, 600000);

    int old_s = modbus_get_socket(ctx);
    modbus_set_socket(ctx, -1);
    rc = modbus_receive(ctx, rsp);
    modbus_set_socket(ctx, old_s);
    printf("* modbus_receive with invalid socket: ");
    ASSERT_TRUE(rc == -1, "FAILED (%d)\n", rc);

    req_length = modbus_send_raw_request(ctx, read_raw_req, READ_RAW_REQ_LEN);
    printf("* modbus_send_raw_request: ");
    ASSERT_TRUE(req_length == (backend_length + 5), "FAILED (%d)\n", req_length);

    printf("* modbus_receive_confirmation: ");
    rc = modbus_receive_confirmation(ctx, rsp);
    ASSERT_TRUE(rc == (backend_length + 12), "FAILED (%d)\n", rc);

    /* Try to read more values than a response could hold for all data
       types. */
    for (i = 0; i < 4; i++) {
        rc = send_crafted_request(ctx,
                                  tab_read_function[i],
                                  read_raw_req,
                                  READ_RAW_REQ_LEN,
                                  tab_read_nb_max[i],
                                  0,
                                  backend_length,
                                  backend_offset);
        if (rc == -1)
            goto close;
    }

    rc = send_crafted_request(ctx,
                              MODBUS_FC_WRITE_AND_READ_REGISTERS,
                              rw_raw_req,
                              RW_RAW_REQ_LEN,
                              MODBUS_MAX_WR_READ_REGISTERS + 1,
                              0,
                              backend_length,
                              backend_offset);
    if (rc == -1)
        goto close;

    rc = send_crafted_request(ctx,
                              MODBUS_FC_WRITE_MULTIPLE_REGISTERS,
                              write_raw_req,
                              WRITE_RAW_REQ_LEN,
                              MODBUS_MAX_WRITE_REGISTERS + 1,
                              6,
                              backend_length,
                              backend_offset);
    if (rc == -1)
        goto close;

    rc = send_crafted_request(ctx,
                              MODBUS_FC_WRITE_MULTIPLE_COILS,
                              write_raw_req,
                              WRITE_RAW_REQ_LEN,
                              MODBUS_MAX_WRITE_BITS + 1,
                              6,
                              backend_length,
                              backend_offset);
    if (rc == -1)
        goto close;

    /* Modbus write multiple registers with large number of values but a set a
       small number of bytes in requests (not nb * 2 as usual). */
    rc = send_crafted_request(ctx,
                              MODBUS_FC_WRITE_MULTIPLE_REGISTERS,
                              write_raw_req,
                              WRITE_RAW_REQ_LEN,
                              MODBUS_MAX_WRITE_REGISTERS,
                              6,
                              backend_length,
                              backend_offset);
    if (rc == -1)
        goto close;

    rc = send_crafted_request(ctx,
                              MODBUS_FC_WRITE_MULTIPLE_COILS,
                              write_raw_req,
                              WRITE_RAW_REQ_LEN,
                              MODBUS_MAX_WRITE_BITS,
                              6,
                              backend_length,
                              backend_offset);
    if (rc == -1)
        goto close;

    /* Test invalid function code */
    modbus_send_raw_request(
        ctx, invalid_fc_raw_req, INVALID_FC_REQ_LEN * sizeof(uint8_t));
    rc = modbus_receive_confirmation(ctx, rsp);
    printf("Return an exception on unknown function code: ");
    ASSERT_TRUE(rc == (backend_length + EXCEPTION_RC) &&
                    rsp[backend_offset] == (0x80 + INVALID_FC),
                "")

    modbus_set_response_timeout(ctx, old_response_to_sec, old_response_to_usec);
    return 0;
close:
    modbus_set_response_timeout(ctx, old_response_to_sec, old_response_to_usec);
    return -1;
}

int send_crafted_request(modbus_t *ctx,
                         int function,
                         uint8_t *req,
                         int req_len,
                         uint16_t max_value,
                         uint16_t bytes,
                         int backend_length,
                         int backend_offset)
{
    uint8_t rsp[MODBUS_TCP_MAX_ADU_LENGTH];
    int j;

    for (j = 0; j < 2; j++) {
        int rc;

        req[1] = function;
        if (j == 0) {
            /* Try to read or write zero values on first iteration */
            req[4] = 0x00;
            req[5] = 0x00;
            if (bytes) {
                /* Write query */
                req[6] = 0x00;
            }
        } else {
            /* Try to read or write max values + 1 on second iteration */
            req[4] = (max_value >> 8) & 0xFF;
            req[5] = max_value & 0xFF;
            if (bytes) {
                /* Write query (nb values * 2 to convert in bytes for registers) */
                req[6] = bytes;
            }
        }

        modbus_send_raw_request(ctx, req, req_len * sizeof(uint8_t));
        if (j == 0) {
            printf(
                "* try function 0x%X: %s 0 values: ", function, bytes ? "write" : "read");
        } else {
            printf("* try function 0x%X: %s %d values: ",
                   function,
                   bytes ? "write" : "read",
                   max_value);
        }
        rc = modbus_receive_confirmation(ctx, rsp);
        ASSERT_TRUE(rc == (backend_length + EXCEPTION_RC) &&
                        rsp[backend_offset] == (0x80 + function) &&
                        rsp[backend_offset + 1] == MODBUS_EXCEPTION_ILLEGAL_DATA_VALUE,
                    "");
    }
    return 0;
close:
    return -1;
}

<MSG> Replace MODBUS_MAX_* by MODBUS_MAX_[READ|WRITE]_*

<DFF> @@ -372,7 +372,7 @@ int main(void)
     /** TOO MANY DATA **/
     printf("\nTEST TOO MANY DATA ERROR:\n");
 
-    rc = modbus_read_bits(ctx, UT_BITS_ADDRESS, MODBUS_MAX_BITS + 1,
+    rc = modbus_read_bits(ctx, UT_BITS_ADDRESS, MODBUS_MAX_READ_BITS + 1,
                           tab_rp_bits);
     printf("* modbus_read_bits: ");
     if (rc == -1 && errno == EMBMDATA) {
@@ -383,7 +383,7 @@ int main(void)
     }
 
     rc = modbus_read_input_bits(ctx, UT_INPUT_BITS_ADDRESS,
-                                MODBUS_MAX_BITS + 1,
+                                MODBUS_MAX_READ_BITS + 1,
                                 tab_rp_bits);
     printf("* modbus_read_input_bits: ");
     if (rc == -1 && errno == EMBMDATA) {
@@ -394,7 +394,7 @@ int main(void)
     }
 
     rc = modbus_read_registers(ctx, UT_REGISTERS_ADDRESS,
-                               MODBUS_MAX_REGISTERS + 1,
+                               MODBUS_MAX_READ_REGISTERS + 1,
                                tab_rp_registers);
     printf("* modbus_read_registers: ");
     if (rc == -1 && errno == EMBMDATA) {
@@ -405,7 +405,7 @@ int main(void)
     }
 
     rc = modbus_read_input_registers(ctx, UT_INPUT_REGISTERS_ADDRESS,
-                                     MODBUS_MAX_REGISTERS + 1,
+                                     MODBUS_MAX_READ_REGISTERS + 1,
                                      tab_rp_registers);
     printf("* modbus_read_input_registers: ");
     if (rc == -1 && errno == EMBMDATA) {
@@ -416,7 +416,7 @@ int main(void)
     }
 
     rc = modbus_write_bits(ctx, UT_BITS_ADDRESS,
-                           MODBUS_MAX_BITS + 1,
+                           MODBUS_MAX_WRITE_BITS + 1,
                            tab_rp_bits);
     printf("* modbus_write_bits: ");
     if (rc == -1 && errno == EMBMDATA) {
@@ -427,7 +427,7 @@ int main(void)
     }
 
     rc = modbus_write_registers(ctx, UT_REGISTERS_ADDRESS,
-                                MODBUS_MAX_REGISTERS + 1,
+                                MODBUS_MAX_WRITE_REGISTERS + 1,
                                 tab_rp_registers);
     printf("* modbus_write_registers: ");
     if (rc == -1 && errno == EMBMDATA) {

{'commit': 'diff --git a/src/modbus.c b/src/modbus.c\nindex f2b35d8..1d7b137 100644\n--- a/src/modbus.c\n+++ b/src/modbus.c\n@@ -1186,11 +1186,11 @@ int modbus_read_bits(modbus_t *ctx, int addr, int nb, uint8_t *data_dest)\n {\n     int rc;\n \n-    if (nb > MODBUS_MAX_BITS) {\n+    if (nb > MODBUS_MAX_READ_BITS) {\n         if (ctx->debug) {\n             fprintf(stderr,\n                     "ERROR Too many bits requested (%d > %d)\\n",\n-                    nb, MODBUS_MAX_BITS);\n+                    nb, MODBUS_MAX_READ_BITS);\n         }\n         errno = EMBMDATA;\n         return -1;\n@@ -1210,11 +1210,11 @@ int modbus_read_input_bits(modbus_t *ctx, int addr, int nb, uint8_t *data_dest)\n {\n     int rc;\n \n-    if (nb > MODBUS_MAX_BITS) {\n+    if (nb > MODBUS_MAX_READ_BITS) {\n         if (ctx->debug) {\n             fprintf(stderr,\n                     "ERROR Too many discrete inputs requested (%d > %d)\\n",\n-                    nb, MODBUS_MAX_BITS);\n+                    nb, MODBUS_MAX_READ_BITS);\n         }\n         errno = EMBMDATA;\n         return -1;\n@@ -1237,11 +1237,11 @@ static int read_registers(modbus_t *ctx, int function, int addr, int nb,\n     uint8_t req[MIN_REQ_LENGTH];\n     uint8_t rsp[MAX_MESSAGE_LENGTH];\n \n-    if (nb > MODBUS_MAX_REGISTERS) {\n+    if (nb > MODBUS_MAX_READ_REGISTERS) {\n         if (ctx->debug) {\n             fprintf(stderr,\n                     "ERROR Too many registers requested (%d > %d)\\n",\n-                    nb, MODBUS_MAX_REGISTERS);\n+                    nb, MODBUS_MAX_READ_REGISTERS);\n         }\n         errno = EMBMDATA;\n         return -1;\n@@ -1275,11 +1275,11 @@ int modbus_read_registers(modbus_t *ctx, int addr, int nb, uint16_t *data_dest)\n {\n     int status;\n \n-    if (nb > MODBUS_MAX_REGISTERS) {\n+    if (nb > MODBUS_MAX_READ_REGISTERS) {\n         if (ctx->debug) {\n             fprintf(stderr,\n                     "ERROR Too many registers requested (%d > %d)\\n",\n-                    nb, MODBUS_MAX_REGISTERS);\n+                    nb, MODBUS_MAX_READ_REGISTERS);\n         }\n         errno = EMBMDATA;\n         return -1;\n@@ -1296,10 +1296,10 @@ int modbus_read_input_registers(modbus_t *ctx, int addr, int nb,\n {\n     int status;\n \n-    if (nb > MODBUS_MAX_REGISTERS) {\n+    if (nb > MODBUS_MAX_READ_REGISTERS) {\n         fprintf(stderr,\n                 "ERROR Too many input registers requested (%d > %d)\\n",\n-                nb, MODBUS_MAX_REGISTERS);\n+                nb, MODBUS_MAX_READ_REGISTERS);\n         errno = EMBMDATA;\n         return -1;\n     }\n@@ -1365,10 +1365,10 @@ int modbus_write_bits(modbus_t *ctx, int addr, int nb, const uint8_t *data_src)\n \n     uint8_t req[MAX_MESSAGE_LENGTH];\n \n-    if (nb > MODBUS_MAX_BITS) {\n+    if (nb > MODBUS_MAX_WRITE_BITS) {\n         if (ctx->debug) {\n             fprintf(stderr, "ERROR Writing too many bits (%d > %d)\\n",\n-                    nb, MODBUS_MAX_BITS);\n+                    nb, MODBUS_MAX_WRITE_BITS);\n         }\n         errno = EMBMDATA;\n         return -1;\n@@ -1416,11 +1416,11 @@ int modbus_write_registers(modbus_t *ctx, int addr, int nb, const uint16_t *data\n \n     uint8_t req[MAX_MESSAGE_LENGTH];\n \n-    if (nb > MODBUS_MAX_REGISTERS) {\n+    if (nb > MODBUS_MAX_WRITE_REGISTERS) {\n         if (ctx->debug) {\n             fprintf(stderr,\n                     "ERROR Trying to write to too many registers (%d > %d)\\n",\n-                    nb, MODBUS_MAX_REGISTERS);\n+                    nb, MODBUS_MAX_WRITE_REGISTERS);\n         }\n         errno = EMBMDATA;\n         return -1;\ndiff --git a/src/modbus.h b/src/modbus.h\nindex 367d973..852b231 100644\n--- a/src/modbus.h\n+++ b/src/modbus.h\n@@ -78,14 +78,23 @@ MODBUS_BEGIN_DECLS\n #define MODBUS_MAX_ADU_LENGTH_TCP  260\n \n /* Modbus_Application_Protocol_V1_1b.pdf (chapter 6 section 1 page 12)\n- * Quantity of Coils (2 bytes): 1 to 2000 (0x7D0)\n+ * Quantity of Coils to read (2 bytes): 1 to 2000 (0x7D0)\n+ * (chapter 6 section 11 page 29)\n+ * Quantity of Coils to write (2 bytes): 1 to 1968 (0x7B0)\n  */\n-#define MODBUS_MAX_BITS              2000\n+#define MODBUS_MAX_READ_BITS              2000\n+#define MODBUS_MAX_WRITE_BITS             1968\n \n /* Modbus_Application_Protocol_V1_1b.pdf (chapter 6 section 3 page 15)\n- * Quantity of Registers (2 bytes): 1 to 125 (0x7D)\n+ * Quantity of Registers to read (2 bytes): 1 to 125 (0x7D)\n+ * (chapter 6 section 12 page 31)\n+ * Quantity of Registers to write (2 bytes) 1 to 123 (0x7B)\n+ * (chapter 6 section 17 page 38)\n+ * Quantity of Registers to write in R/W registers (2 bytes) 1 to 121 (0x79)\n  */\n-#define MODBUS_MAX_REGISTERS          125\n+#define MODBUS_MAX_READ_REGISTERS          125\n+#define MODBUS_MAX_WRITE_REGISTERS         123\n+#define MODBUS_MAX_RW_WRITE_REGISTERS      121\n \n /* Random number to avoid errno conflicts */\n #define MODBUS_ENOBASE 112345678\ndiff --git a/tests/bandwidth-client.c b/tests/bandwidth-client.c\nindex f1216e2..f562018 100644\n--- a/tests/bandwidth-client.c\n+++ b/tests/bandwidth-client.c\n@@ -62,16 +62,16 @@ int main(void)\n     }\n \n     /* Allocate and initialize the memory to store the status */\n-    tab_bit = (uint8_t *) malloc(MODBUS_MAX_BITS * sizeof(uint8_t));\n-    memset(tab_bit, 0, MODBUS_MAX_BITS * sizeof(uint8_t));\n+    tab_bit = (uint8_t *) malloc(MODBUS_MAX_READ_BITS * sizeof(uint8_t));\n+    memset(tab_bit, 0, MODBUS_MAX_READ_BITS * sizeof(uint8_t));\n \n     /* Allocate and initialize the memory to store the registers */\n-    tab_reg = (uint16_t *) malloc(MODBUS_MAX_REGISTERS * sizeof(uint16_t));\n-    memset(tab_reg, 0, MODBUS_MAX_REGISTERS * sizeof(uint16_t));\n+    tab_reg = (uint16_t *) malloc(MODBUS_MAX_READ_REGISTERS * sizeof(uint16_t));\n+    memset(tab_reg, 0, MODBUS_MAX_READ_REGISTERS * sizeof(uint16_t));\n \n     printf("READ BITS\\n\\n");\n \n-    nb_points = MODBUS_MAX_BITS;\n+    nb_points = MODBUS_MAX_READ_BITS;\n     start = gettime_ms();\n     for (i=0; i<NB_LOOPS; i++) {\n         rc = modbus_read_bits(ctx, 0, nb_points, tab_bit);\n@@ -108,7 +108,7 @@ int main(void)\n \n     printf("READ REGISTERS\\n\\n");\n \n-    nb_points = MODBUS_MAX_REGISTERS;\n+    nb_points = MODBUS_MAX_READ_REGISTERS;\n     start = gettime_ms();\n     for (i=0; i<NB_LOOPS; i++) {\n         rc = modbus_read_registers(ctx, 0, nb_points, tab_reg);\ndiff --git a/tests/bandwidth-server-many-up.c b/tests/bandwidth-server-many-up.c\nindex 0cce2ec..8b02085 100644\n--- a/tests/bandwidth-server-many-up.c\n+++ b/tests/bandwidth-server-many-up.c\n@@ -51,8 +51,8 @@ int main(void)\n \n     ctx = modbus_new_tcp("127.0.0.1", 1502);\n \n-    mb_mapping = modbus_mapping_new(MODBUS_MAX_BITS, 0,\n-                                    MODBUS_MAX_REGISTERS, 0);\n+    mb_mapping = modbus_mapping_new(MODBUS_MAX_READ_BITS, 0,\n+                                    MODBUS_MAX_READ_REGISTERS, 0);\n     if (mb_mapping == NULL) {\n         fprintf(stderr, "Failed to allocate the mapping: %s\\n",\n                 modbus_strerror(errno));\ndiff --git a/tests/bandwidth-server-one.c b/tests/bandwidth-server-one.c\nindex 7dad899..97471a2 100644\n--- a/tests/bandwidth-server-one.c\n+++ b/tests/bandwidth-server-one.c\n@@ -32,8 +32,8 @@ int main(void)\n \n     ctx = modbus_new_tcp("127.0.0.1", 1502);\n \n-    mb_mapping = modbus_mapping_new(MODBUS_MAX_BITS, 0,\n-                                    MODBUS_MAX_REGISTERS, 0);\n+    mb_mapping = modbus_mapping_new(MODBUS_MAX_READ_BITS, 0,\n+                                    MODBUS_MAX_READ_REGISTERS, 0);\n     if (mb_mapping == NULL) {\n         fprintf(stderr, "Failed to allocate the mapping: %s\\n",\n                 modbus_strerror(errno));\ndiff --git a/tests/unit-test-client.c b/tests/unit-test-client.c\nindex 4dd0ea0..5e7f0d3 100644\n--- a/tests/unit-test-client.c\n+++ b/tests/unit-test-client.c\n@@ -372,7 +372,7 @@ int main(void)\n     /** TOO MANY DATA **/\n     printf("\\nTEST TOO MANY DATA ERROR:\\n");\n \n-    rc = modbus_read_bits(ctx, UT_BITS_ADDRESS, MODBUS_MAX_BITS + 1,\n+    rc = modbus_read_bits(ctx, UT_BITS_ADDRESS, MODBUS_MAX_READ_BITS + 1,\n                           tab_rp_bits);\n     printf("* modbus_read_bits: ");\n     if (rc == -1 && errno == EMBMDATA) {\n@@ -383,7 +383,7 @@ int main(void)\n     }\n \n     rc = modbus_read_input_bits(ctx, UT_INPUT_BITS_ADDRESS,\n-                                MODBUS_MAX_BITS + 1,\n+                                MODBUS_MAX_READ_BITS + 1,\n                                 tab_rp_bits);\n     printf("* modbus_read_input_bits: ");\n     if (rc == -1 && errno == EMBMDATA) {\n@@ -394,7 +394,7 @@ int main(void)\n     }\n \n     rc = modbus_read_registers(ctx, UT_REGISTERS_ADDRESS,\n-                               MODBUS_MAX_REGISTERS + 1,\n+                               MODBUS_MAX_READ_REGISTERS + 1,\n                                tab_rp_registers);\n     printf("* modbus_read_registers: ");\n     if (rc == -1 && errno == EMBMDATA) {\n@@ -405,7 +405,7 @@ int main(void)\n     }\n \n     rc = modbus_read_input_registers(ctx, UT_INPUT_REGISTERS_ADDRESS,\n-                                     MODBUS_MAX_REGISTERS + 1,\n+                                     MODBUS_MAX_READ_REGISTERS + 1,\n                                      tab_rp_registers);\n     printf("* modbus_read_input_registers: ");\n     if (rc == -1 && errno == EMBMDATA) {\n@@ -416,7 +416,7 @@ int main(void)\n     }\n \n     rc = modbus_write_bits(ctx, UT_BITS_ADDRESS,\n-                           MODBUS_MAX_BITS + 1,\n+                           MODBUS_MAX_WRITE_BITS + 1,\n                            tab_rp_bits);\n     printf("* modbus_write_bits: ");\n     if (rc == -1 && errno == EMBMDATA) {\n@@ -427,7 +427,7 @@ int main(void)\n     }\n \n     rc = modbus_write_registers(ctx, UT_REGISTERS_ADDRESS,\n-                                MODBUS_MAX_REGISTERS + 1,\n+                                MODBUS_MAX_WRITE_REGISTERS + 1,\n                                 tab_rp_registers);\n     printf("* modbus_write_registers: ");\n     if (rc == -1 && errno == EMBMDATA) {\n', 'commit_subject': 'Replace MODBUS_MAX_* by MODBUS_MAX_[READ|WRITE]_*', 'repo_name': 'stephane/libmodbus', 'committer': {'name': 'Stéphane Raimbault', 'email': 'e6653fe7eaf151c38caf35761f7ffd50c65aa112@gmail.com', 'time_sec': '1281421607', 'tz_offset': '120', 'date': {'seconds': '1281421607'}}, 'commit_tree': '582a56a0fd83893b94bfc92607f0cb64b8d8340d', 'commit_message': 'Replace MODBUS_MAX_* by MODBUS_MAX_[READ|WRITE]_*\n', 'language_name': 'JavaScript', 'license': 'lgpl-2.1', 'hunks': '@@ -372,7 +372,7 @@ int main(void)\n     /** TOO MANY DATA **/\n     printf("\\nTEST TOO MANY DATA ERROR:\\n");\n \n-    rc = modbus_read_bits(ctx, UT_BITS_ADDRESS, MODBUS_MAX_BITS + 1,\n+    rc = modbus_read_bits(ctx, UT_BITS_ADDRESS, MODBUS_MAX_READ_BITS + 1,\n                           tab_rp_bits);\n     printf("* modbus_read_bits: ");\n     if (rc == -1 && errno == EMBMDATA) {\n@@ -383,7 +383,7 @@ int main(void)\n     }\n \n     rc = modbus_read_input_bits(ctx, UT_INPUT_BITS_ADDRESS,\n-                                MODBUS_MAX_BITS + 1,\n+                                MODBUS_MAX_READ_BITS + 1,\n                                 tab_rp_bits);\n     printf("* modbus_read_input_bits: ");\n     if (rc == -1 && errno == EMBMDATA) {\n@@ -394,7 +394,7 @@ int main(void)\n     }\n \n     rc = modbus_read_registers(ctx, UT_REGISTERS_ADDRESS,\n-                               MODBUS_MAX_REGISTERS + 1,\n+                               MODBUS_MAX_READ_REGISTERS + 1,\n                                tab_rp_registers);\n     printf("* modbus_read_registers: ");\n     if (rc == -1 && errno == EMBMDATA) {\n@@ -405,7 +405,7 @@ int main(void)\n     }\n \n     rc = modbus_read_input_registers(ctx, UT_INPUT_REGISTERS_ADDRESS,\n-                                     MODBUS_MAX_REGISTERS + 1,\n+                                     MODBUS_MAX_READ_REGISTERS + 1,\n                                      tab_rp_registers);\n     printf("* modbus_read_input_registers: ");\n     if (rc == -1 && errno == EMBMDATA) {\n@@ -416,7 +416,7 @@ int main(void)\n     }\n \n     rc = modbus_write_bits(ctx, UT_BITS_ADDRESS,\n-                           MODBUS_MAX_BITS + 1,\n+                           MODBUS_MAX_WRITE_BITS + 1,\n                            tab_rp_bits);\n     printf("* modbus_write_bits: ");\n     if (rc == -1 && errno == EMBMDATA) {\n@@ -427,7 +427,7 @@ int main(void)\n     }\n \n     rc = modbus_write_registers(ctx, UT_REGISTERS_ADDRESS,\n-                                MODBUS_MAX_REGISTERS + 1,\n+                                MODBUS_MAX_WRITE_REGISTERS + 1,\n                                 tab_rp_registers);\n     printf("* modbus_write_registers: ");\n     if (rc == -1 && errno == EMBMDATA) {\n', 'addition_count': 6, 'deletion_count': 6, 'src_file': 'a/tests/unit-test-client.c', 'tgt_file': 'b/tests/unit-test-client.c', 'file_extension': '.c', 'before_file': '/*\n * Copyright © Stéphane Raimbault <stephane.raimbault@gmail.com>\n *\n * SPDX-License-Identifier: BSD-3-Clause\n */\n\n#include <errno.h>\n#include <modbus.h>\n#include <stdio.h>\n#include <stdlib.h>\n#include <string.h>\n#include <unistd.h>\n\n#include "unit-test.h"\n\nconst int EXCEPTION_RC = 2;\n\nenum {\n    TCP,\n    TCP_PI,\n    RTU\n};\n\nint test_server(modbus_t *ctx, int use_backend);\nint send_crafted_request(modbus_t *ctx,\n                         int function,\n                         uint8_t *req,\n                         int req_size,\n                         uint16_t max_value,\n                         uint16_t bytes,\n                         int backend_length,\n                         int backend_offset);\nint equal_dword(uint16_t *tab_reg, const uint32_t value);\nint is_memory_equal(const void *s1, const void *s2, size_t size);\n\n#define BUG_REPORT(_cond, _format, _args...) \\\n  printf("\\nLine %d: assertion error for \'%s\': " _format "\\n", __LINE__, #_cond, ##_args)\n\n#define ASSERT_TRUE(_cond, _format, __args...) \\\n  {                                            \\\n    if (_cond) {                               \\\n      printf("OK\\n");                          \\\n    } else {                                   \\\n      BUG_REPORT(_cond, _format, ##__args);    \\\n      goto close;                              \\\n    }                                          \\\n  };\n\nint is_memory_equal(const void *s1, const void *s2, size_t size)\n{\n    return (memcmp(s1, s2, size) == 0);\n}\n\nint equal_dword(uint16_t *tab_reg, const uint32_t value)\n{\n    return ((tab_reg[0] == (value >> 16)) && (tab_reg[1] == (value & 0xFFFF)));\n}\n\nint main(int argc, char *argv[])\n{\n    const int NB_REPORT_SLAVE_ID = 10;\n    uint8_t *tab_rp_bits = NULL;\n    uint16_t *tab_rp_registers = NULL;\n    uint16_t *tab_rp_registers_bad = NULL;\n    modbus_t *ctx = NULL;\n    int i;\n    uint8_t value;\n    int nb_points;\n    int rc;\n    float real;\n    uint32_t old_response_to_sec;\n    uint32_t old_response_to_usec;\n    uint32_t new_response_to_sec;\n    uint32_t new_response_to_usec;\n    uint32_t old_byte_to_sec;\n    uint32_t old_byte_to_usec;\n    int use_backend;\n    int success = FALSE;\n    int old_slave;\n\n    if (argc > 1) {\n        if (strcmp(argv[1], "tcp") == 0) {\n            use_backend = TCP;\n        } else if (strcmp(argv[1], "tcppi") == 0) {\n            use_backend = TCP_PI;\n        } else if (strcmp(argv[1], "rtu") == 0) {\n            use_backend = RTU;\n        } else {\n            printf("Usage:\\n  %s [tcp|tcppi|rtu] - Modbus client for unit testing\\n\\n",\n                   argv[0]);\n            exit(1);\n        }\n    } else {\n        /* By default */\n        use_backend = TCP;\n    }\n\n    if (use_backend == TCP) {\n        ctx = modbus_new_tcp("127.0.0.1", 1502);\n    } else if (use_backend == TCP_PI) {\n        ctx = modbus_new_tcp_pi("::1", "1502");\n    } else {\n        ctx = modbus_new_rtu("/dev/ttyUSB1", 115200, \'N\', 8, 1);\n    }\n    if (ctx == NULL) {\n        fprintf(stderr, "Unable to allocate libmodbus context\\n");\n        return -1;\n    }\n    modbus_set_debug(ctx, TRUE);\n    modbus_set_error_recovery(\n        ctx, MODBUS_ERROR_RECOVERY_LINK | MODBUS_ERROR_RECOVERY_PROTOCOL);\n\n    if (use_backend == RTU) {\n        modbus_set_slave(ctx, SERVER_ID);\n    }\n\n    modbus_get_response_timeout(ctx, &old_response_to_sec, &old_response_to_usec);\n    if (modbus_connect(ctx) == -1) {\n        fprintf(stderr, "Connection failed: %s\\n", modbus_strerror(errno));\n        modbus_free(ctx);\n        return -1;\n    }\n\n    /* Allocate and initialize the memory to store the bits */\n    nb_points = (UT_BITS_NB > UT_INPUT_BITS_NB) ? UT_BITS_NB : UT_INPUT_BITS_NB;\n    tab_rp_bits = (uint8_t *) malloc(nb_points * sizeof(uint8_t));\n    memset(tab_rp_bits, 0, nb_points * sizeof(uint8_t));\n\n    /* Allocate and initialize the memory to store the registers */\n    nb_points = (UT_REGISTERS_NB > UT_INPUT_REGISTERS_NB) ? UT_REGISTERS_NB\n                                                          : UT_INPUT_REGISTERS_NB;\n    tab_rp_registers = (uint16_t *) malloc(nb_points * sizeof(uint16_t));\n    memset(tab_rp_registers, 0, nb_points * sizeof(uint16_t));\n\n    printf("** UNIT TESTING **\\n");\n\n    printf("1/1 No response timeout modification on connect: ");\n    modbus_get_response_timeout(ctx, &new_response_to_sec, &new_response_to_usec);\n    ASSERT_TRUE(old_response_to_sec == new_response_to_sec &&\n                    old_response_to_usec == new_response_to_usec,\n                "");\n\n    printf("\\nTEST WRITE/READ:\\n");\n\n    /** COIL BITS **/\n\n    /* Single */\n    rc = modbus_write_bit(ctx, UT_BITS_ADDRESS, ON);\n    printf("1/2 modbus_write_bit: ");\n    ASSERT_TRUE(rc == 1, "");\n\n    rc = modbus_read_bits(ctx, UT_BITS_ADDRESS, 1, tab_rp_bits);\n    printf("2/2 modbus_read_bits: ");\n    ASSERT_TRUE(rc == 1, "FAILED (nb points %d)\\n", rc);\n    ASSERT_TRUE(tab_rp_bits[0] == ON, "FAILED (%0X != %0X)\\n", tab_rp_bits[0], ON);\n\n    /* End single */\n\n    /* Multiple bits */\n    {\n        uint8_t tab_value[UT_BITS_NB];\n\n        modbus_set_bits_from_bytes(tab_value, 0, UT_BITS_NB, UT_BITS_TAB);\n        rc = modbus_write_bits(ctx, UT_BITS_ADDRESS, UT_BITS_NB, tab_value);\n        printf("1/2 modbus_write_bits: ");\n        ASSERT_TRUE(rc == UT_BITS_NB, "");\n    }\n\n    rc = modbus_read_bits(ctx, UT_BITS_ADDRESS, UT_BITS_NB, tab_rp_bits);\n    printf("2/2 modbus_read_bits: ");\n    ASSERT_TRUE(rc == UT_BITS_NB, "FAILED (nb points %d)\\n", rc);\n\n    i = 0;\n    nb_points = UT_BITS_NB;\n    while (nb_points > 0) {\n        int nb_bits = (nb_points > 8) ? 8 : nb_points;\n\n        value = modbus_get_byte_from_bits(tab_rp_bits, i * 8, nb_bits);\n        ASSERT_TRUE(\n            value == UT_BITS_TAB[i], "FAILED (%0X != %0X)\\n", value, UT_BITS_TAB[i]);\n\n        nb_points -= nb_bits;\n        i++;\n    }\n    printf("OK\\n");\n    /* End of multiple bits */\n\n    /** DISCRETE INPUTS **/\n    rc =\n        modbus_read_input_bits(ctx, UT_INPUT_BITS_ADDRESS, UT_INPUT_BITS_NB, tab_rp_bits);\n    printf("1/1 modbus_read_input_bits: ");\n    ASSERT_TRUE(rc == UT_INPUT_BITS_NB, "FAILED (nb points %d)\\n", rc);\n\n    i = 0;\n    nb_points = UT_INPUT_BITS_NB;\n    while (nb_points > 0) {\n        int nb_bits = (nb_points > 8) ? 8 : nb_points;\n        value = modbus_get_byte_from_bits(tab_rp_bits, i * 8, nb_bits);\n        ASSERT_TRUE(value == UT_INPUT_BITS_TAB[i],\n                    "FAILED (%0X != %0X)\\n",\n                    value,\n                    UT_INPUT_BITS_TAB[i]);\n\n        nb_points -= nb_bits;\n        i++;\n    }\n    printf("OK\\n");\n\n    /** HOLDING REGISTERS **/\n\n    /* Single register */\n    rc = modbus_write_register(ctx, UT_REGISTERS_ADDRESS, 0x1234);\n    printf("1/2 modbus_write_register: ");\n    ASSERT_TRUE(rc == 1, "");\n\n    rc = modbus_read_registers(ctx, UT_REGISTERS_ADDRESS, 1, tab_rp_registers);\n    printf("2/2 modbus_read_registers: ");\n    ASSERT_TRUE(rc == 1, "FAILED (nb points %d)\\n", rc);\n    ASSERT_TRUE(tab_rp_registers[0] == 0x1234,\n                "FAILED (%0X != %0X)\\n",\n                tab_rp_registers[0],\n                0x1234);\n    /* End of single register */\n\n    /* Many registers */\n    rc = modbus_write_registers(\n        ctx, UT_REGISTERS_ADDRESS, UT_REGISTERS_NB, UT_REGISTERS_TAB);\n    printf("1/5 modbus_write_registers: ");\n    ASSERT_TRUE(rc == UT_REGISTERS_NB, "");\n\n    rc = modbus_read_registers(\n        ctx, UT_REGISTERS_ADDRESS, UT_REGISTERS_NB, tab_rp_registers);\n    printf("2/5 modbus_read_registers: ");\n    ASSERT_TRUE(rc == UT_REGISTERS_NB, "FAILED (nb points %d)\\n", rc);\n\n    for (i = 0; i < UT_REGISTERS_NB; i++) {\n        ASSERT_TRUE(tab_rp_registers[i] == UT_REGISTERS_TAB[i],\n                    "FAILED (%0X != %0X)\\n",\n                    tab_rp_registers[i],\n                    UT_REGISTERS_TAB[i]);\n    }\n\n    rc = modbus_read_registers(ctx, UT_REGISTERS_ADDRESS, 0, tab_rp_registers);\n    printf("3/5 modbus_read_registers (0): ");\n    ASSERT_TRUE(rc == -1, "FAILED (nb_points %d)\\n", rc);\n\n    nb_points = (UT_REGISTERS_NB > UT_INPUT_REGISTERS_NB) ? UT_REGISTERS_NB\n                                                          : UT_INPUT_REGISTERS_NB;\n    memset(tab_rp_registers, 0, nb_points * sizeof(uint16_t));\n\n    /* Write registers to zero from tab_rp_registers and store read registers\n       into tab_rp_registers. So the read registers must set to 0, except the\n       first one because there is an offset of 1 register on write. */\n    rc = modbus_write_and_read_registers(ctx,\n                                         UT_REGISTERS_ADDRESS + 1,\n                                         UT_REGISTERS_NB - 1,\n                                         tab_rp_registers,\n                                         UT_REGISTERS_ADDRESS,\n                                         UT_REGISTERS_NB,\n                                         tab_rp_registers);\n    printf("4/5 modbus_write_and_read_registers: ");\n    ASSERT_TRUE(\n        rc == UT_REGISTERS_NB, "FAILED (nb points %d != %d)\\n", rc, UT_REGISTERS_NB);\n\n    ASSERT_TRUE(tab_rp_registers[0] == UT_REGISTERS_TAB[0],\n                "FAILED (%0X != %0X)\\n",\n                tab_rp_registers[0],\n                UT_REGISTERS_TAB[0]);\n\n    for (i = 1; i < UT_REGISTERS_NB; i++) {\n        ASSERT_TRUE(\n            tab_rp_registers[i] == 0, "FAILED (%0X != %0X)\\n", tab_rp_registers[i], 0);\n    }\n\n    /* End of many registers */\n\n    /** INPUT REGISTERS **/\n    rc = modbus_read_input_registers(\n        ctx, UT_INPUT_REGISTERS_ADDRESS, UT_INPUT_REGISTERS_NB, tab_rp_registers);\n    printf("1/1 modbus_read_input_registers: ");\n    ASSERT_TRUE(rc == UT_INPUT_REGISTERS_NB, "FAILED (nb points %d)\\n", rc);\n\n    for (i = 0; i < UT_INPUT_REGISTERS_NB; i++) {\n        ASSERT_TRUE(tab_rp_registers[i] == UT_INPUT_REGISTERS_TAB[i],\n                    "FAILED (%0X != %0X)\\n",\n                    tab_rp_registers[i],\n                    UT_INPUT_REGISTERS_TAB[i]);\n    }\n\n    /* MASKS */\n    printf("1/1 Write mask: ");\n    rc = modbus_write_register(ctx, UT_REGISTERS_ADDRESS, 0x12);\n    rc = modbus_mask_write_register(ctx, UT_REGISTERS_ADDRESS, 0xF2, 0x25);\n    ASSERT_TRUE(rc != -1, "FAILED (%x == -1)\\n", rc);\n    rc = modbus_read_registers(ctx, UT_REGISTERS_ADDRESS, 1, tab_rp_registers);\n    ASSERT_TRUE(\n        tab_rp_registers[0] == 0x17, "FAILED (%0X != %0X)\\n", tab_rp_registers[0], 0x17);\n\n    printf("\\nTEST FLOATS\\n");\n    /** FLOAT **/\n    printf("1/4 Set/get float ABCD: ");\n    modbus_set_float_abcd(UT_REAL, tab_rp_registers);\n    ASSERT_TRUE(is_memory_equal(tab_rp_registers, UT_IREAL_ABCD_SET, 4),\n                "FAILED Set float ABCD");\n    real = modbus_get_float_abcd(UT_IREAL_ABCD_GET);\n    ASSERT_TRUE(real == UT_REAL, "FAILED (%f != %f)\\n", real, UT_REAL);\n\n    printf("2/4 Set/get float DCBA: ");\n    modbus_set_float_dcba(UT_REAL, tab_rp_registers);\n    ASSERT_TRUE(is_memory_equal(tab_rp_registers, UT_IREAL_DCBA_SET, 4),\n                "FAILED Set float DCBA");\n    real = modbus_get_float_dcba(UT_IREAL_DCBA_GET);\n    ASSERT_TRUE(real == UT_REAL, "FAILED (%f != %f)\\n", real, UT_REAL);\n\n    printf("3/4 Set/get float BADC: ");\n    modbus_set_float_badc(UT_REAL, tab_rp_registers);\n    ASSERT_TRUE(is_memory_equal(tab_rp_registers, UT_IREAL_BADC_SET, 4),\n                "FAILED Set float BADC");\n    real = modbus_get_float_badc(UT_IREAL_BADC_GET);\n    ASSERT_TRUE(real == UT_REAL, "FAILED (%f != %f)\\n", real, UT_REAL);\n\n    printf("4/4 Set/get float CDAB: ");\n    modbus_set_float_cdab(UT_REAL, tab_rp_registers);\n    ASSERT_TRUE(is_memory_equal(tab_rp_registers, UT_IREAL_CDAB_SET, 4),\n                "FAILED Set float CDAB");\n    real = modbus_get_float_cdab(UT_IREAL_CDAB_GET);\n    ASSERT_TRUE(real == UT_REAL, "FAILED (%f != %f)\\n", real, UT_REAL);\n\n    printf("\\nAt this point, error messages doesn\'t mean the test has failed\\n");\n\n    /** ILLEGAL DATA ADDRESS **/\n    printf("\\nTEST ILLEGAL DATA ADDRESS:\\n");\n\n    /* The mapping begins at the defined addresses and ends at address +\n     * nb_points so these addresses are not valid. */\n\n    rc = modbus_read_bits(ctx, 0, 1, tab_rp_bits);\n    printf("* modbus_read_bits (0): ");\n    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");\n\n    rc = modbus_read_bits(ctx, UT_BITS_ADDRESS, UT_BITS_NB + 1, tab_rp_bits);\n    printf("* modbus_read_bits (max): ");\n    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");\n\n    rc = modbus_read_input_bits(ctx, 0, 1, tab_rp_bits);\n    printf("* modbus_read_input_bits (0): ");\n    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");\n\n    rc = modbus_read_input_bits(\n        ctx, UT_INPUT_BITS_ADDRESS, UT_INPUT_BITS_NB + 1, tab_rp_bits);\n    printf("* modbus_read_input_bits (max): ");\n    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");\n\n    rc = modbus_read_registers(ctx, 0, 1, tab_rp_registers);\n    printf("* modbus_read_registers (0): ");\n    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");\n\n    rc = modbus_read_registers(\n        ctx, UT_REGISTERS_ADDRESS, UT_REGISTERS_NB_MAX + 1, tab_rp_registers);\n    printf("* modbus_read_registers (max): ");\n    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");\n\n    rc = modbus_read_input_registers(ctx, 0, 1, tab_rp_registers);\n    printf("* modbus_read_input_registers (0): ");\n    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");\n\n    rc = modbus_read_input_registers(\n        ctx, UT_INPUT_REGISTERS_ADDRESS, UT_INPUT_REGISTERS_NB + 1, tab_rp_registers);\n    printf("* modbus_read_input_registers (max): ");\n    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");\n\n    /** TOO MANY DATA **/\n    printf("\\nTEST TOO MANY DATA ERROR:\\n");\n\n    rc = modbus_read_bits(ctx, UT_BITS_ADDRESS, MODBUS_MAX_BITS + 1,\n                          tab_rp_bits);\n    printf("* modbus_read_bits: ");\n    if (rc == -1 && errno == EMBMDATA) {\n\n    rc = modbus_write_bits(ctx, 0, 1, tab_rp_bits);\n    printf("* modbus_write_coils (0): ");\n    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");\n    }\n\n    rc = modbus_read_input_bits(ctx, UT_INPUT_BITS_ADDRESS,\n                                MODBUS_MAX_BITS + 1,\n                                tab_rp_bits);\n    printf("* modbus_read_input_bits: ");\n    if (rc == -1 && errno == EMBMDATA) {\n    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");\n\n    rc = modbus_write_register(\n        ctx, UT_REGISTERS_ADDRESS + UT_REGISTERS_NB_MAX, tab_rp_registers[0]);\n    }\n\n    rc = modbus_read_registers(ctx, UT_REGISTERS_ADDRESS,\n                               MODBUS_MAX_REGISTERS + 1,\n                               tab_rp_registers);\n    printf("* modbus_read_registers: ");\n    if (rc == -1 && errno == EMBMDATA) {\n    rc = modbus_write_registers(ctx,\n                                UT_REGISTERS_ADDRESS + UT_REGISTERS_NB_MAX,\n                                UT_REGISTERS_NB,\n                                tab_rp_registers);\n    }\n\n    rc = modbus_read_input_registers(ctx, UT_INPUT_REGISTERS_ADDRESS,\n                                     MODBUS_MAX_REGISTERS + 1,\n                                     tab_rp_registers);\n    printf("* modbus_read_input_registers: ");\n    if (rc == -1 && errno == EMBMDATA) {\n    rc = modbus_mask_write_register(\n        ctx, UT_REGISTERS_ADDRESS + UT_REGISTERS_NB_MAX, 0xF2, 0x25);\n    printf("* modbus_mask_write_registers (max): ");\n    ASSERT_TRUE(rc == -1 && errno == EMBXILADD, "");\n    }\n\n    rc = modbus_write_bits(ctx, UT_BITS_ADDRESS,\n                           MODBUS_MAX_BITS + 1,\n                           tab_rp_bits);\n    printf("* modbus_write_bits: ");\n    if (rc == -1 && errno == EMBMDATA) {\n                                         UT_REGISTERS_ADDRESS + UT_REGISTERS_NB_MAX,\n                                         UT_REGISTERS_NB,\n                                         tab_rp_registers,\n                                         UT_REGISTERS_ADDRESS + UT_REGISTERS_NB_MAX,\n    }\n\n    rc = modbus_write_registers(ctx, UT_REGISTERS_ADDRESS,\n                                MODBUS_MAX_REGISTERS + 1,\n                                tab_rp_registers);\n    printf("* modbus_write_registers: ");\n    if (rc == -1 && errno == EMBMDATA) {\n\n    rc = modbus_read_bits(ctx, UT_BITS_ADDRESS, MODBUS_MAX_READ_BITS + 1, tab_rp_bits);\n    printf("* modbus_read_bits: ");\n    ASSERT_TRUE(rc == -1 && errno == EMBMDATA, "");\n\n    rc = modbus_read_input_bits(\n        ctx, UT_INPUT_BITS_ADDRESS, MODBUS_MAX_READ_BITS + 1, tab_rp_bits);\n    printf("* modbus_read_input_bits: ");\n    ASSERT_TRUE(rc == -1 && errno == EMBMDATA, "");\n\n    rc = modbus_read_registers(\n        ctx, UT_REGISTERS_ADDRESS, MODBUS_MAX_READ_REGISTERS + 1, tab_rp_registers);\n    printf("* modbus_read_registers: ");\n    ASSERT_TRUE(rc == -1 && errno == EMBMDATA, "");\n\n    rc = modbus_read_input_registers(\n        ctx, UT_INPUT_REGISTERS_ADDRESS, MODBUS_MAX_READ_REGISTERS + 1, tab_rp_registers);\n    printf("* modbus_read_input_registers: ");\n    ASSERT_TRUE(rc == -1 && errno == EMBMDATA, "");\n\n    rc = modbus_write_bits(ctx, UT_BITS_ADDRESS, MODBUS_MAX_WRITE_BITS + 1, tab_rp_bits);\n    printf("* modbus_write_bits: ");\n    ASSERT_TRUE(rc == -1 && errno == EMBMDATA, "");\n\n    rc = modbus_write_registers(\n        ctx, UT_REGISTERS_ADDRESS, MODBUS_MAX_WRITE_REGISTERS + 1, tab_rp_registers);\n    printf("* modbus_write_registers: ");\n    ASSERT_TRUE(rc == -1 && errno == EMBMDATA, "");\n\n    /** SLAVE ADDRESS **/\n    old_slave = modbus_get_slave(ctx);\n\n    printf("\\nTEST SLAVE ADDRESS:\\n");\n\n    printf("1/2 Not compliant slave address is refused: ");\n    rc = modbus_set_slave(ctx, 248);\n    ASSERT_TRUE(rc == -1, "Slave address of 248 shouldn\'t be allowed");\n\n    printf("2/2 Not compliant slave address is allowed: ");\n    modbus_enable_quirks(ctx, MODBUS_QUIRK_MAX_SLAVE);\n    rc = modbus_set_slave(ctx, 248);\n    ASSERT_TRUE(rc == 0, "Not compliant slave address should have been accepted");\n\n    modbus_disable_quirks(ctx, MODBUS_QUIRK_MAX_SLAVE);\n    rc = modbus_set_slave(ctx, old_slave);\n    ASSERT_TRUE(rc == 0, "Uanble to restore slave value")\n\n    /** SLAVE REPLY **/\n\n    printf("\\nTEST SLAVE REPLY:\\n");\n    modbus_set_slave(ctx, INVALID_SERVER_ID);\n    rc = modbus_read_registers(\n        ctx, UT_REGISTERS_ADDRESS, UT_REGISTERS_NB, tab_rp_registers);\n    if (use_backend == RTU) {\n        const int RAW_REQ_LENGTH = 6;\n        uint8_t raw_req[] = {INVALID_SERVER_ID, 0x03, 0x00, 0x01, 0x01, 0x01};\n        /* Too many points */\n        uint8_t raw_invalid_req[] = {INVALID_SERVER_ID, 0x03, 0x00, 0x01, 0xFF, 0xFF};\n        const int RAW_RSP_LENGTH = 7;\n        uint8_t raw_rsp[] = {INVALID_SERVER_ID, 0x03, 0x04, 0, 0, 0, 0};\n        uint8_t rsp[MODBUS_RTU_MAX_ADU_LENGTH];\n\n        /* No response in RTU mode */\n        printf("1-A/3 No response from slave %d: ", INVALID_SERVER_ID);\n        ASSERT_TRUE(rc == -1 && errno == ETIMEDOUT, "");\n\n        /* The slave raises a timeout on a confirmation to ignore because if an\n         * indication for another slave is received, a confirmation must follow */\n\n        /* Send a pair of indication/confirmation to the slave with a different\n         * slave ID to simulate a communication on a RS485 bus. At first, the\n         * slave will see the indication message then the confirmation, and it must\n         * ignore both. */\n        modbus_send_raw_request(ctx, raw_req, RAW_REQ_LENGTH * sizeof(uint8_t));\n        modbus_send_raw_request(ctx, raw_rsp, RAW_RSP_LENGTH * sizeof(uint8_t));\n        rc = modbus_receive_confirmation(ctx, rsp);\n\n        printf("1-B/3 No response from slave %d on indication/confirmation messages: ",\n               INVALID_SERVER_ID);\n        ASSERT_TRUE(rc == -1 && errno == ETIMEDOUT, "");\n\n        /* Send an INVALID request for another slave */\n        modbus_send_raw_request(ctx, raw_invalid_req, RAW_REQ_LENGTH * sizeof(uint8_t));\n        rc = modbus_receive_confirmation(ctx, rsp);\n\n        printf("1-C/3 No response from slave %d with invalid request: ",\n               INVALID_SERVER_ID);\n        ASSERT_TRUE(rc == -1 && errno == ETIMEDOUT, "");\n\n        rc = modbus_set_slave(ctx, MODBUS_BROADCAST_ADDRESS);\n        ASSERT_TRUE(rc == 0, "Invalid broadcast address");\n\n        rc = modbus_read_registers(\n            ctx, UT_REGISTERS_ADDRESS, UT_REGISTERS_NB, tab_rp_registers);\n        printf("2/3 No reply after a broadcast query: ");\n        ASSERT_TRUE(rc == -1 && errno == ETIMEDOUT, "");\n    } else {\n        /* Response in TCP mode */\n        printf("1/3 Response from slave %d: ", INVALID_SERVER_ID);\n        ASSERT_TRUE(rc == UT_REGISTERS_NB, "");\n\n        rc = modbus_set_slave(ctx, MODBUS_BROADCAST_ADDRESS);\n        ASSERT_TRUE(rc == 0, "Invalid broacast address");\n\n        rc = modbus_read_registers(\n            ctx, UT_REGISTERS_ADDRESS, UT_REGISTERS_NB, tab_rp_registers);\n        printf("2/3 Reply after a query with unit id == 0: ");\n        ASSERT_TRUE(rc == UT_REGISTERS_NB, "");\n    }\n\n    /* Restore slave */\n    modbus_set_slave(ctx, old_slave);\n\n    printf("3/3 Response with an invalid TID or slave: ");\n    rc = modbus_read_registers(\n        ctx, UT_REGISTERS_ADDRESS_INVALID_TID_OR_SLAVE, 1, tab_rp_registers);\n    ASSERT_TRUE(rc == -1, "");\n\n    printf("1/2 Report slave ID truncated: \\n");\n    /* Set a marker to ensure limit is respected */\n    tab_rp_bits[NB_REPORT_SLAVE_ID - 1] = 42;\n    rc = modbus_report_slave_id(ctx, NB_REPORT_SLAVE_ID - 1, tab_rp_bits);\n    /* Return the size required (response size) but respects the defined limit */\n    ASSERT_TRUE(rc == NB_REPORT_SLAVE_ID && tab_rp_bits[NB_REPORT_SLAVE_ID - 1] == 42,\n                "Return is rc %d (%d) and marker is %d (42)",\n                rc,\n                NB_REPORT_SLAVE_ID,\n                tab_rp_bits[NB_REPORT_SLAVE_ID - 1]);\n\n    printf("2/2 Report slave ID: \\n");\n    /* tab_rp_bits is used to store bytes */\n    rc = modbus_report_slave_id(ctx, NB_REPORT_SLAVE_ID, tab_rp_bits);\n    ASSERT_TRUE(rc == NB_REPORT_SLAVE_ID, "");\n\n    /* Slave ID is an arbitrary number for libmodbus */\n    ASSERT_TRUE(rc > 0, "");\n\n    /* Run status indicator is ON */\n    ASSERT_TRUE(rc > 1 && tab_rp_bits[1] == 0xFF, "");\n\n    /* Print additional data as string */\n    if (rc > 2) {\n        printf("Additional data: ");\n        for (i = 2; i < rc; i++) {\n            printf("%c", tab_rp_bits[i]);\n        }\n        printf("\\n");\n    }\n\n    /* Save original timeout */\n    modbus_get_response_timeout(ctx, &old_response_to_sec, &old_response_to_usec);\n    modbus_get_byte_timeout(ctx, &old_byte_to_sec, &old_byte_to_usec);\n\n    rc = modbus_set_response_timeout(ctx, 0, 0);\n    printf("1/6 Invalid response timeout (zero): ");\n    ASSERT_TRUE(rc == -1 && errno == EINVAL, "");\n\n    rc = modbus_set_response_timeout(ctx, 0, 1000000);\n    printf("2/6 Invalid response timeout (too large us): ");\n    ASSERT_TRUE(rc == -1 && errno == EINVAL, "");\n\n    rc = modbus_set_byte_timeout(ctx, 0, 1000000);\n    printf("3/6 Invalid byte timeout (too large us): ");\n    ASSERT_TRUE(rc == -1 && errno == EINVAL, "");\n\n    modbus_set_response_timeout(ctx, 0, 1);\n    rc = modbus_read_registers(\n        ctx, UT_REGISTERS_ADDRESS, UT_REGISTERS_NB, tab_rp_registers);\n    printf("4/6 1us response timeout: ");\n    if (rc == -1 && errno == ETIMEDOUT) {\n        printf("OK\\n");\n    } else {\n        printf("FAILED (can fail on some platforms)\\n");\n    }\n\n    /* A wait and flush operation is done by the error recovery code of\n     * libmodbus but after a sleep of current response timeout\n     * so 0 can be too short!\n     */\n    usleep(old_response_to_sec * 1000000 + old_response_to_usec);\n    modbus_flush(ctx);\n\n    /* Trigger a special behaviour on server to wait for 0.5 second before\n     * replying whereas allowed timeout is 0.2 second */\n    modbus_set_response_timeout(ctx, 0, 200000);\n    rc = modbus_read_registers(\n        ctx, UT_REGISTERS_ADDRESS_SLEEP_500_MS, 1, tab_rp_registers);\n    printf("5/6 Too short response timeout (0.2s < 0.5s): ");\n    ASSERT_TRUE(rc == -1 && errno == ETIMEDOUT, "");\n\n    /* Wait for reply (0.2 + 0.4 > 0.5 s) and flush before continue */\n    usleep(400000);\n    modbus_flush(ctx);\n\n    modbus_set_response_timeout(ctx, 0, 600000);\n    rc = modbus_read_registers(\n        ctx, UT_REGISTERS_ADDRESS_SLEEP_500_MS, 1, tab_rp_registers);\n    printf("6/6 Adequate response timeout (0.6s > 0.5s): ");\n    ASSERT_TRUE(rc == 1, "");\n\n    /* Disable the byte timeout.\n       The full response must be available in the 600ms interval */\n    modbus_set_byte_timeout(ctx, 0, 0);\n    rc = modbus_read_registers(\n        ctx, UT_REGISTERS_ADDRESS_SLEEP_500_MS, 1, tab_rp_registers);\n    printf("7/7 Disable byte timeout: ");\n    ASSERT_TRUE(rc == 1, "");\n\n    /* Restore original response timeout */\n    modbus_set_response_timeout(ctx, old_response_to_sec, old_response_to_usec);\n\n    if (use_backend == TCP) {\n        /* The test server is only able to test byte timeouts with the TCP\n         * backend */\n\n        /* Timeout of 3ms between bytes */\n        modbus_set_byte_timeout(ctx, 0, 3000);\n        rc = modbus_read_registers(\n            ctx, UT_REGISTERS_ADDRESS_BYTE_SLEEP_5_MS, 1, tab_rp_registers);\n        printf("1/2 Too small byte timeout (3ms < 5ms): ");\n        ASSERT_TRUE(rc == -1 && errno == ETIMEDOUT, "");\n\n        /* Wait remaining bytes before flushing */\n        usleep(11 * 5000);\n        modbus_flush(ctx);\n\n        /* Timeout of 7ms between bytes */\n        modbus_set_byte_timeout(ctx, 0, 7000);\n        rc = modbus_read_registers(\n            ctx, UT_REGISTERS_ADDRESS_BYTE_SLEEP_5_MS, 1, tab_rp_registers);\n        printf("2/2 Adapted byte timeout (7ms > 5ms): ");\n        ASSERT_TRUE(rc == 1, "");\n    }\n\n    /* Restore original byte timeout */\n    modbus_set_byte_timeout(ctx, old_byte_to_sec, old_byte_to_usec);\n\n    /** BAD RESPONSE **/\n    printf("\\nTEST BAD RESPONSE ERROR:\\n");\n\n    /* Allocate only the required space */\n    tab_rp_registers_bad =\n        (uint16_t *) malloc(UT_REGISTERS_NB_SPECIAL * sizeof(uint16_t));\n\n    rc = modbus_read_registers(\n        ctx, UT_REGISTERS_ADDRESS, UT_REGISTERS_NB_SPECIAL, tab_rp_registers_bad);\n    printf("* modbus_read_registers: ");\n    ASSERT_TRUE(rc == -1 && errno == EMBBADDATA, "");\n    free(tab_rp_registers_bad);\n\n    /** MANUAL EXCEPTION **/\n    printf("\\nTEST MANUAL EXCEPTION:\\n");\n    rc = modbus_read_registers(\n        ctx, UT_REGISTERS_ADDRESS_SPECIAL, UT_REGISTERS_NB, tab_rp_registers);\n\n    printf("* modbus_read_registers at special address: ");\n    ASSERT_TRUE(rc == -1 && errno == EMBXSBUSY, "");\n\n    /** Run a few tests to challenge the server code **/\n    if (test_server(ctx, use_backend) == -1) {\n        goto close;\n    }\n\n    modbus_close(ctx);\n    modbus_free(ctx);\n    ctx = NULL;\n\n    /* Test init functions */\n    printf("\\nTEST INVALID INITIALIZATION:\\n");\n    ctx = modbus_new_rtu(NULL, 1, \'A\', 0, 0);\n    ASSERT_TRUE(ctx == NULL && errno == EINVAL, "");\n\n    ctx = modbus_new_rtu("/dev/dummy", 0, \'A\', 0, 0);\n    ASSERT_TRUE(ctx == NULL && errno == EINVAL, "");\n\n    printf("\\nALL TESTS PASS WITH SUCCESS.\\n");\n    success = TRUE;\n\nclose:\n    /* Free the memory */\n    free(tab_rp_bits);\n    free(tab_rp_registers);\n\n    /* Close the connection */\n    modbus_close(ctx);\n    modbus_free(ctx);\n\n    return (success) ? 0 : -1;\n}\n\n/* Send crafted requests to test server resilience\n   and ensure proper exceptions are returned. */\nint test_server(modbus_t *ctx, int use_backend)\n{\n    int rc;\n    int i;\n    /* Read requests */\n    const int READ_RAW_REQ_LEN = 6;\n    const int slave = (use_backend == RTU) ? SERVER_ID : MODBUS_TCP_SLAVE;\n    uint8_t read_raw_req[] = {slave,\n                              /* function, address, 5 values */\n                              MODBUS_FC_READ_HOLDING_REGISTERS,\n                              UT_REGISTERS_ADDRESS >> 8,\n                              UT_REGISTERS_ADDRESS & 0xFF,\n                              0x0,\n                              0x05};\n    /* Write and read registers request */\n    const int RW_RAW_REQ_LEN = 13;\n    uint8_t rw_raw_req[] = {slave,\n                            /* function, addr to read, nb to read */\n                            MODBUS_FC_WRITE_AND_READ_REGISTERS,\n                            /* Read */\n                            UT_REGISTERS_ADDRESS >> 8,\n                            UT_REGISTERS_ADDRESS & 0xFF,\n                            (MODBUS_MAX_WR_READ_REGISTERS + 1) >> 8,\n                            (MODBUS_MAX_WR_READ_REGISTERS + 1) & 0xFF,\n                            /* Write */\n                            0,\n                            0,\n                            0,\n                            1,\n                            /* Write byte count */\n                            1 * 2,\n                            /* One data to write... */\n                            0x12,\n                            0x34};\n    const int WRITE_RAW_REQ_LEN = 13;\n    uint8_t write_raw_req[] = {slave,\n                               /* function will be set in the loop */\n                               MODBUS_FC_WRITE_MULTIPLE_REGISTERS,\n                               /* Address */\n                               UT_REGISTERS_ADDRESS >> 8,\n                               UT_REGISTERS_ADDRESS & 0xFF,\n                               /* 3 values, 6 bytes */\n                               0x00,\n                               0x03,\n                               0x06,\n                               /* Dummy data to write */\n                               0x02,\n                               0x2B,\n                               0x00,\n                               0x01,\n                               0x00,\n                               0x64};\n    const int INVALID_FC = 0x42;\n    const int INVALID_FC_REQ_LEN = 6;\n    uint8_t invalid_fc_raw_req[] = {slave, 0x42, 0x00, 0x00, 0x00, 0x00};\n\n    int req_length;\n    uint8_t rsp[MODBUS_TCP_MAX_ADU_LENGTH];\n    int tab_read_function[] = {MODBUS_FC_READ_COILS,\n                               MODBUS_FC_READ_DISCRETE_INPUTS,\n                               MODBUS_FC_READ_HOLDING_REGISTERS,\n                               MODBUS_FC_READ_INPUT_REGISTERS};\n    int tab_read_nb_max[] = {MODBUS_MAX_READ_BITS + 1,\n                             MODBUS_MAX_READ_BITS + 1,\n                             MODBUS_MAX_READ_REGISTERS + 1,\n                             MODBUS_MAX_READ_REGISTERS + 1};\n    int backend_length;\n    int backend_offset;\n\n    if (use_backend == RTU) {\n        backend_length = 3;\n        backend_offset = 1;\n    } else {\n        backend_length = 7;\n        backend_offset = 7;\n    }\n\n    printf("\\nTEST RAW REQUESTS:\\n");\n\n    uint32_t old_response_to_sec;\n    uint32_t old_response_to_usec;\n\n    /* This requests can generate flushes server side so we need a higher\n     * response timeout than the server. The server uses the defined response\n     * timeout to sleep before flushing.\n     * The old timeouts are restored at the end.\n     */\n    modbus_get_response_timeout(ctx, &old_response_to_sec, &old_response_to_usec);\n    modbus_set_response_timeout(ctx, 0, 600000);\n\n    int old_s = modbus_get_socket(ctx);\n    modbus_set_socket(ctx, -1);\n    rc = modbus_receive(ctx, rsp);\n    modbus_set_socket(ctx, old_s);\n    printf("* modbus_receive with invalid socket: ");\n    ASSERT_TRUE(rc == -1, "FAILED (%d)\\n", rc);\n\n    req_length = modbus_send_raw_request(ctx, read_raw_req, READ_RAW_REQ_LEN);\n    printf("* modbus_send_raw_request: ");\n    ASSERT_TRUE(req_length == (backend_length + 5), "FAILED (%d)\\n", req_length);\n\n    printf("* modbus_receive_confirmation: ");\n    rc = modbus_receive_confirmation(ctx, rsp);\n    ASSERT_TRUE(rc == (backend_length + 12), "FAILED (%d)\\n", rc);\n\n    /* Try to read more values than a response could hold for all data\n       types. */\n    for (i = 0; i < 4; i++) {\n        rc = send_crafted_request(ctx,\n                                  tab_read_function[i],\n                                  read_raw_req,\n                                  READ_RAW_REQ_LEN,\n                                  tab_read_nb_max[i],\n                                  0,\n                                  backend_length,\n                                  backend_offset);\n        if (rc == -1)\n            goto close;\n    }\n\n    rc = send_crafted_request(ctx,\n                              MODBUS_FC_WRITE_AND_READ_REGISTERS,\n                              rw_raw_req,\n                              RW_RAW_REQ_LEN,\n                              MODBUS_MAX_WR_READ_REGISTERS + 1,\n                              0,\n                              backend_length,\n                              backend_offset);\n    if (rc == -1)\n        goto close;\n\n    rc = send_crafted_request(ctx,\n                              MODBUS_FC_WRITE_MULTIPLE_REGISTERS,\n                              write_raw_req,\n                              WRITE_RAW_REQ_LEN,\n                              MODBUS_MAX_WRITE_REGISTERS + 1,\n                              6,\n                              backend_length,\n                              backend_offset);\n    if (rc == -1)\n        goto close;\n\n    rc = send_crafted_request(ctx,\n                              MODBUS_FC_WRITE_MULTIPLE_COILS,\n                              write_raw_req,\n                              WRITE_RAW_REQ_LEN,\n                              MODBUS_MAX_WRITE_BITS + 1,\n                              6,\n                              backend_length,\n                              backend_offset);\n    if (rc == -1)\n        goto close;\n\n    /* Modbus write multiple registers with large number of values but a set a\n       small number of bytes in requests (not nb * 2 as usual). */\n    rc = send_crafted_request(ctx,\n                              MODBUS_FC_WRITE_MULTIPLE_REGISTERS,\n                              write_raw_req,\n                              WRITE_RAW_REQ_LEN,\n                              MODBUS_MAX_WRITE_REGISTERS,\n                              6,\n                              backend_length,\n                              backend_offset);\n    if (rc == -1)\n        goto close;\n\n    rc = send_crafted_request(ctx,\n                              MODBUS_FC_WRITE_MULTIPLE_COILS,\n                              write_raw_req,\n                              WRITE_RAW_REQ_LEN,\n                              MODBUS_MAX_WRITE_BITS,\n                              6,\n                              backend_length,\n                              backend_offset);\n    if (rc == -1)\n        goto close;\n\n    /* Test invalid function code */\n    modbus_send_raw_request(\n        ctx, invalid_fc_raw_req, INVALID_FC_REQ_LEN * sizeof(uint8_t));\n    rc = modbus_receive_confirmation(ctx, rsp);\n    printf("Return an exception on unknown function code: ");\n    ASSERT_TRUE(rc == (backend_length + EXCEPTION_RC) &&\n                    rsp[backend_offset] == (0x80 + INVALID_FC),\n                "")\n\n    modbus_set_response_timeout(ctx, old_response_to_sec, old_response_to_usec);\n    return 0;\nclose:\n    modbus_set_response_timeout(ctx, old_response_to_sec, old_response_to_usec);\n    return -1;\n}\n\nint send_crafted_request(modbus_t *ctx,\n                         int function,\n                         uint8_t *req,\n                         int req_len,\n                         uint16_t max_value,\n                         uint16_t bytes,\n                         int backend_length,\n                         int backend_offset)\n{\n    uint8_t rsp[MODBUS_TCP_MAX_ADU_LENGTH];\n    int j;\n\n    for (j = 0; j < 2; j++) {\n        int rc;\n\n        req[1] = function;\n        if (j == 0) {\n            /* Try to read or write zero values on first iteration */\n            req[4] = 0x00;\n            req[5] = 0x00;\n            if (bytes) {\n                /* Write query */\n                req[6] = 0x00;\n            }\n        } else {\n            /* Try to read or write max values + 1 on second iteration */\n            req[4] = (max_value >> 8) & 0xFF;\n            req[5] = max_value & 0xFF;\n            if (bytes) {\n                /* Write query (nb values * 2 to convert in bytes for registers) */\n                req[6] = bytes;\n            }\n        }\n\n        modbus_send_raw_request(ctx, req, req_len * sizeof(uint8_t));\n        if (j == 0) {\n            printf(\n                "* try function 0x%X: %s 0 values: ", function, bytes ? "write" : "read");\n        } else {\n            printf("* try function 0x%X: %s %d values: ",\n                   function,\n                   bytes ? "write" : "read",\n                   max_value);\n        }\n        rc = modbus_receive_confirmation(ctx, rsp);\n        ASSERT_TRUE(rc == (backend_length + EXCEPTION_RC) &&\n                        rsp[backend_offset] == (0x80 + function) &&\n                        rsp[backend_offset + 1] == MODBUS_EXCEPTION_ILLEGAL_DATA_VALUE,\n                    "");\n    }\n    return 0;\nclose:\n    return -1;\n}\n', 'message': 'Replace MODBUS_MAX_* by MODBUS_MAX_[READ|WRITE]_*\n', 'author_name': 'Stéphane Raimbault', 'lang': 'c'}