main_ppp_espidf.c

/*
 * Copyright 2019-2024 u-blox
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/** @brief This example demonstrates how to bring up a network
 * connection and then perform sockets operations using the native
 * IP stack of the ESP-IDF platform.
 *
 * For this example to run you must define U_CFG_PPP_ENABLE when
 * building ubxlib; you could do this by appending it to the
 * ESP-IDF CMake variable COMPILE_DEFINITIONS, which is applied
 * to all components (ubxlib is a component), in your top-level
 * CMakeLists.txt file with a line as follows:
 *
 * add_compile_definitions(U_CFG_PPP_ENABLE)
 *
 *...or by including it in the U_FLAGS environment variable that the
 * ubxlib ESP-IDF component looks for by executing a line in the
 * console where you are performing your build such as, for Windows:
 *
 * set U_FLAGS=-DU_CFG_PPP_ENABLE
 *
 * ..or for Linux:
 *
 * export U_FLAGS=-DU_CFG_PPP_ENABLE
 *
 * You must also bring in the right ESP-IDF components through menuconfig
 * by going to "Component Config" and making sure that the following are
 * ticked:
 *
 * - "ESP NETIF Adapter --> TCP/IP Stack Library (LwIP) --> LwIP"
 * - "LWIP --> Enable PAP support"
 * - if your network operator requires a user name and password along
 *   with the APN **AND** requires CHAP authentication, then also
 *   "LWIP --> Enable CHAP support".
 *
 * Alternatively, if you prefer to set things up manually, rather than
 * through menuconfig, then switch on the following in your sdkconfig
 * file:
 *
 * - CONFIG_LWIP_PPP_SUPPORT
 * - CONFIG_ESP_NETIF_TCPIP_LWIP
 * - CONFIG_LWIP_PPP_PAP_SUPPORT
 * - CONFIG_LWIP_PPP_CHAP_SUPPORT (if required)
 *
 * ...and, if you are minimising the components built into your main
 * application, you may need to add the ESP-IDF component "esp_netif"
 * to your component list.
 *
 * The choice of [cellular] module is made at build time, see the
 * README.md for instructions.
 */

// This example is only for the ESP-IDF platform
#ifdef __XTENSA__

// Bring in all of the ubxlib public header files
#include "ubxlib.h"

// Bring in the ESP-IDF CONFIG_ #defines
#include "sdkconfig.h"

#if defined(CONFIG_LWIP_PPP_SUPPORT) && defined(U_CFG_PPP_ENABLE)

// The BSD sockets interface of ESP-IDF
#include "unistd.h"
#include "sys/socket.h"
#include "netdb.h"
#include "arpa/inet.h"
#include "errno.h"

#ifndef U_PORT_TEST_FUNCTION
// The ESP-IDF network interface that allows us to connect PPP
# include "esp_event.h"
# include "esp_netif.h"
#endif

// Bring in the application settings
#include "u_cfg_app_platform_specific.h"

#ifndef U_CFG_DISABLE_TEST_AUTOMATION
// This purely for internal u-blox testing
# include "u_cfg_test_platform_specific.h"
#endif

/* ----------------------------------------------------------------
 * COMPILE-TIME MACROS
 * -------------------------------------------------------------- */

// Echo server URL and port number
#define MY_SERVER_NAME "ubxlib.com"
#define MY_SERVER_PORT 5055

// For u-blox internal testing only
#ifdef U_PORT_TEST_ASSERT
# define EXAMPLE_FINAL_STATE(x) U_PORT_TEST_ASSERT(x);
#else
# define EXAMPLE_FINAL_STATE(x)
#endif

#ifndef U_PORT_TEST_FUNCTION
# error if you are not using the unit test framework to run this code you must ensure that the platform clocks/RTOS are set up and either define U_PORT_TEST_FUNCTION yourself or replace it as necessary.
#endif

/* ----------------------------------------------------------------
 * TYPES
 * -------------------------------------------------------------- */

/* ----------------------------------------------------------------
 * VARIABLES
 * -------------------------------------------------------------- */

#ifdef U_CFG_TEST_CELL_MODULE_TYPE
// Set U_CFG_TEST_CELL_MODULE_TYPE to your module type,
// chosen from the values in cell/api/u_cell_module_type.h
//
// Note that the pin numbers are those of the MCU: if you
// are using an MCU inside a u-blox module the IO pin numbering
// for the module is likely different that from the MCU: check
// the data sheet for the module to determine the mapping.

// DEVICE i.e. module/chip configuration: in this case a cellular
// module connected via UART
static const uDeviceCfg_t gDeviceCfg = {
    .deviceType = U_DEVICE_TYPE_CELL,
    .deviceCfg = {
        .cfgCell = {
            .moduleType = U_CFG_TEST_CELL_MODULE_TYPE,
            .pSimPinCode = NULL, /* SIM pin */
            .pinEnablePower = U_CFG_APP_PIN_CELL_ENABLE_POWER,
            .pinPwrOn = U_CFG_APP_PIN_CELL_PWR_ON,
            .pinVInt = U_CFG_APP_PIN_CELL_VINT,
            .pinDtrPowerSaving = U_CFG_APP_PIN_CELL_DTR
        },
    },
    .transportType = U_DEVICE_TRANSPORT_TYPE_UART,
    .transportCfg = {
        .cfgUart = {
            .uart = U_CFG_APP_CELL_UART,
            .baudRate = U_CELL_UART_BAUD_RATE,
            .pinTxd = U_CFG_APP_PIN_CELL_TXD,
            .pinRxd = U_CFG_APP_PIN_CELL_RXD,
            .pinCts = U_CFG_APP_PIN_CELL_CTS,
            .pinRts = U_CFG_APP_PIN_CELL_RTS,
#ifdef U_CFG_APP_UART_PREFIX
            .pPrefix = U_PORT_STRINGIFY_QUOTED(U_CFG_APP_UART_PREFIX) // Relevant for Linux only
#else
            .pPrefix = NULL
#endif
        },
    },
};
// NETWORK configuration
static const uNetworkCfgCell_t gNetworkCfg = {
    .type = U_NETWORK_TYPE_CELL,
    .pApn = NULL, /* APN: NULL to accept default.  If using a Thingstream SIM enter "tsiot" here */
    .timeoutSeconds = 240 /* Connection timeout in seconds */
    // There are six additional fields here which we do NOT set,
    // we allow the compiler to set them to 0 and all will be fine.
    // The fields are:
    //
    // - "pKeepGoingCallback": you may set this field to a function
    //   of the form "bool keepGoingCallback(uDeviceHandle_t devHandle)",
    //   e.g.:
    //
    //   .pKeepGoingCallback = keepGoingCallback;
    //
    //   ...and your function will be called periodically during an
    //   abortable network operation such as connect/disconnect;
    //   if it returns true the operation will continue else it
    //   will be aborted, allowing you immediate control.  If this
    //   field is set, timeoutSeconds will be ignored.
    //
    // - "pUsername" and "pPassword": if you are required to set a
    //   user name and password to go with the APN value that you
    //   were given by your service provider, set them here.
    //
    // - "authenticationMode": if you MUST give a user name and
    //   password then you must populate this field with the
    //   authentication mode that should be used, see
    //   #uCellNetAuthenticationMode_t in u_cell_net.h, and noting
    //   that automatic authentication mode will NOT work with PPP.
    //   You ONLY NEED TO WORRY ABOUT THIS if you were given a user name
    //   name and password with the APN (which is thankfully not usual).
    //
    // - "pMccMnc": ONLY required if you wish to connect to a specific
    //   MCC/MNC rather than to the best available network; should point
    //   to the null-terminated string giving the MCC and MNC of the PLMN
    //   to use (for example "23410").
    //
    // - "pUartPpp": ONLY REQUIRED if U_CFG_PPP_ENABLE is defined AND
    //   you wish to run a PPP interface to the cellular module over a
    //   DIFFERENT serial port to that which was specified in the device
    //   configuration passed to uDeviceOpen().  This is useful if you
    //   are using the USB interface of a cellular module, which does not
    //   support the CMUX protocol that multiplexes PPP with AT.
};
#else
// No module available - set some dummy values to make test system happy
static const uDeviceCfg_t gDeviceCfg = {.deviceType = U_DEVICE_TYPE_NONE};
static const uNetworkCfgCell_t gNetworkCfg = {.type = U_NETWORK_TYPE_NONE};
#endif

/* ----------------------------------------------------------------
 * STATIC FUNCTIONS
 * -------------------------------------------------------------- */

/* ----------------------------------------------------------------
 * PUBLIC FUNCTIONS: THE EXAMPLE
 * -------------------------------------------------------------- */

// The entry point, main(): before this is called the system
// clocks must have been started and the RTOS must be running;
// we are in task space.
U_PORT_TEST_FUNCTION("[example]", "examplePppEspIdfSockets")
{
    uDeviceHandle_t devHandle = NULL;
    struct hostent *pHostEnt;
    struct sockaddr_in destinationAddress = {0};
    int32_t sock;
    const char message[] = "The quick brown espidf-fox jumps over the lazy dog.";
    size_t txSize = sizeof(message);
    char buffer[128];
    size_t rxSize = 0;
    int32_t returnCode;

#ifndef U_PORT_TEST_FUNCTION
    // ESP-IDF requires the application to initialise
    // its network interface and default event loop
    // This is under the switch #ifndef U_PORT_TEST_FUNCTION
    // only because, when we run this for internal
    // testing, the initialisation is done elsewhere

    // These must be called once only, and BEFORE the device
    // is opened
    esp_netif_init();
    esp_event_loop_create_default();
#endif

    // Initialise the APIs we will need
    uPortInit();
    uDeviceInit();

    // Open the device
    returnCode = uDeviceOpen(&gDeviceCfg, &devHandle);
    uPortLog("Opened device with return code %d.\n", returnCode);

    if (returnCode == 0) {
        // Bring up the network interface
        uPortLog("Bringing up the network...\n");
        if (uNetworkInterfaceUp(devHandle, U_NETWORK_TYPE_CELL,
                                &gNetworkCfg) == 0) {

            // ESP-IDF's IP stack is now connected to the
            // internet via the cellular module

            // Look up the IP address of the echo server
            // using the ESP-IDF platform's gethostbyname()
            errno = 0;
            pHostEnt = gethostbyname(MY_SERVER_NAME);
            if (pHostEnt != NULL) {
                uPortLog("Found %s at %s.\n", MY_SERVER_NAME,
                         inet_ntoa(*(struct in_addr *) pHostEnt->h_addr));

                // Call the native BSD sockets APIs of the
                // ESP-IDF platform to send data

                // You could equally use any of the ESP-IDF
                // native protocol entities (MQTT, HTTP, etc.)

                destinationAddress.sin_addr = *(struct in_addr *) pHostEnt->h_addr;
                destinationAddress.sin_family = pHostEnt->h_addrtype;
                destinationAddress.sin_port = htons(MY_SERVER_PORT);
                sock = socket(AF_INET, SOCK_STREAM, IPPROTO_IP);
                if (sock >= 0) {
                    if (connect(sock, (struct sockaddr *) &destinationAddress, sizeof(destinationAddress)) == 0) {
                        if (send(sock, message, txSize, 0) == txSize) {
                            uPortLog("Sent %d byte(s) to echo server.\n", txSize);
                            rxSize = recv(sock, buffer, sizeof(buffer), 0);
                            if (rxSize > 0) {
                                uPortLog("\nReceived echo back (%d byte(s)): %s\n", rxSize, buffer);
                            } else {
                                uPortLog("\nNo reply received!\n");
                            }
                        } else {
                            uPortLog("Unable to send to server (errno %d)!\n", errno);
                        }
                    } else {
                        uPortLog("Unable to connect to server (errno %d)!\n", errno);
                    }
                } else {
                    uPortLog("Unable to create socket (errno %d)!\n", errno);
                }

                // Close the socket
                uPortLog("Closing socket...\n");
                shutdown(sock, 0);
                close(sock);
            } else {
                uPortLog("Unable to find %s (errno %d)!\n", MY_SERVER_NAME, errno);
            }

            // When finished with the network layer
            uPortLog("Taking down network...\n");
            uNetworkInterfaceDown(devHandle, U_NETWORK_TYPE_CELL);
        } else {
            uPortLog("Unable to bring up the network!\n");
        }

        // Close the device
        // Note: we don't power the device down here in order
        // to speed up testing; you may prefer to power it off
        // by setting the second parameter to true.
        uDeviceClose(devHandle, false);

    } else {
        uPortLog("Unable to bring up the device!\n");
    }

    // Tidy up
    uDeviceDeinit();
    uPortDeinit();

    uPortLog("Done.\n");

#ifdef U_CFG_TEST_CELL_MODULE_TYPE
    // For u-blox internal testing only
    EXAMPLE_FINAL_STATE(rxSize == sizeof(message));
#endif
}

#endif // #if defined(CONFIG_LWIP_PPP_SUPPORT) && defined(U_CFG_PPP_ENABLE)
#endif // #ifdef __XTENSA__

// End of file