Hello,
I'm trying to implement a mqtt client with Lwip 2.0.2.
The Vivado version is 2018_1.
The Lwip is part of the BSP.
I used the code of this side as a template: http://www.nongnu.org/lwip/2_0_x/group__mqtt.html
#include <stdio.h>
#include "xparameters.h"
#include "netif/xadapter.h"
#include "platform_config.h"
#include "xil_printf.h"
#include "lwip/apps/mqtt.h"
#include "lwip/apps/mqtt_opts.h"
#include "lwip/err.h"
#include "lwip/ip_addr.h"
static void mqtt_pub_request_cb(void *arg, err_t result);
void example_publish(mqtt_client_t *client, void *arg);
static void mqtt_incoming_publish_cb(void *arg, const char *topic, u32_t tot_len);
static void mqtt_incoming_data_cb(void *arg, const u8_t *data, u16_t len, u8_t flags);
static void mqtt_sub_request_cb(void *arg, err_t result);
static void mqtt_connection_cb(mqtt_client_t *client, void *arg, mqtt_connection_status_t status);
void example_do_connect(mqtt_client_t *client);
/*
* -----------------------------------------------------------------
4. Using outgoing publish
* */
/* Called when publish is complete either with sucess or failure */
static void mqtt_pub_request_cb(void *arg, err_t result)
{
if(result != ERR_OK) {
printf("Publish result: %d\n", result);
}
}
void example_publish(mqtt_client_t *client, void *arg)
{
const char *pub_payload= "PubSubHubLubJub";
err_t err;
u8_t qos = 2; /* 0 1 or 2, see MQTT specification */
u8_t retain = 0; /* No don't retain such crappy payload... */
err = mqtt_publish(client, "pub_topic", pub_payload, strlen(pub_payload), qos, retain, mqtt_pub_request_cb, arg);
if(err != ERR_OK) {
printf("Publish err: %d\n", err);
}
}
/*-----------------------------------------------------------------
3. Implementing callbacks for incoming publish and data*/
/* The idea is to demultiplex topic and create some reference to be used in data callbacks
Example here uses a global variable, better would be to use a member in arg
If RAM and CPU budget allows it, the easiest implementation might be to just take a copy of
the topic string and use it in mqtt_incoming_data_cb
*/
static int inpub_id;
static void mqtt_incoming_publish_cb(void *arg, const char *topic, u32_t tot_len)
{
printf("Incoming publish at topic %s with total length %u\n", topic, (unsigned int)tot_len);
/* Decode topic string into a user defined reference */
if(strcmp(topic, "print_payload") == 0) {
inpub_id = 0;
} else if(topic[0] == 'A') {
/* All topics starting with 'A' might be handled at the same way */
inpub_id = 1;
} else {
/* For all other topics */
inpub_id = 2;
}
}
static void mqtt_incoming_data_cb(void *arg, const u8_t *data, u16_t len, u8_t flags)
{
printf("Incoming publish payload with length %d, flags %u\n", len, (unsigned int)flags);
if(flags & MQTT_DATA_FLAG_LAST) {
/* Last fragment of payload received (or whole part if payload fits receive buffer
See MQTT_VAR_HEADER_BUFFER_LEN) */
/* Call function or do action depending on reference, in this case inpub_id */
if(inpub_id == 0) {
/* Don't trust the publisher, check zero termination */
if(data[len-1] == 0) {
printf("mqtt_incoming_data_cb: %s\n", (const char *)data);
}
} else if(inpub_id == 1) {
/* Call an 'A' function... */
} else {
printf("mqtt_incoming_data_cb: Ignoring payload...\n");
}
} else {
/* Handle fragmented payload, store in buffer, write to file or whatever */
}
}
/*-----------------------------------------------------------------
2. Implementing the connection status callback*/
static void mqtt_sub_request_cb(void *arg, err_t result)
{
/* Just print the result code here for simplicity,
normal behaviour would be to take some action if subscribe fails like
notifying user, retry subscribe or disconnect from server */
printf("Subscribe result: %d\n", result);
}
static void mqtt_connection_cb(mqtt_client_t *client, void *arg, mqtt_connection_status_t status)
{
err_t err;
if(status == MQTT_CONNECT_ACCEPTED) {
printf("mqtt_connection_cb: Successfully connected\n");
/* Setup callback for incoming publish requests */
mqtt_set_inpub_callback(client, mqtt_incoming_publish_cb, mqtt_incoming_data_cb, arg);
/* Subscribe to a topic named "subtopic" with QoS level 1, call mqtt_sub_request_cb with result */
err = mqtt_subscribe(client, "subtopic", 1, mqtt_sub_request_cb, arg);
if(err != ERR_OK) {
printf("mqtt_subscribe return: %d\n", err);
}
} else {
printf("mqtt_connection_cb: Disconnected, reason: %d\n", status);
/* Its more nice to be connected, so try to reconnect */
example_do_connect(client);
}
}
void example_do_connect(mqtt_client_t *client)
{
struct mqtt_connect_client_info_t ci;
ip_addr_t serverIpAddr;
/* initliaze IP addresses to be used */
IP4_ADDR(&serverIpAddr, 192, 168, 1, 10);
//IP4_ADDR(&netmask, 255, 255, 255, 0);
//IP4_ADDR(&gw, 192, 168, 1, 1);
err_t err;
/* Setup an empty client info structure */
memset(&ci, 0, sizeof(ci));
/* Minimal amount of information required is client identifier, so set it here */
ci.client_id = "lwip_test";
/* Initiate client and connect to server, if this fails immediately an error code is returned
otherwise mqtt_connection_cb will be called with connection result after attempting
to establish a connection with the server.
For now MQTT version 3.1.1 is always used */
//err = mqtt_client_connect(client, ip_addr, MQTT_PORT, mqtt_connection_cb, 0, &ci);
err = mqtt_client_connect(client, &serverIpAddr, MQTT_PORT, mqtt_connection_cb, 0, &ci);
/* For now just print the result code if something goes wrong */
if(err != ERR_OK) {
printf("mqtt_connect return %d\n", err);
}
}
int main(){
mqtt_client_t static_client;
example_do_connect(&static_client);
return 0;
}The Sdk generates the following error:
Building target: TestMQTT02.elf
Invoking: ARM v7 gcc linker
arm-none-eabi-gcc -mcpu=cortex-a9 -mfpu=vfpv3 -mfloat-abi=hard -Wl,-build-id=none -specs=Xilinx.spec -Wl,-T -Wl,../src/lscript.ld -L../../TestMQTT_bsp/ps7_cortexa9_0/lib -o "TestMQTT02.elf" ./src/main.o -Wl,--start-group,-lxil,-lfreertos,-lgcc,-lc,--end-group -Wl,--start-group,-lxil,-llwip4,-lgcc,-lc,--end-group
./src/main.o: In function `example_publish':
workspaceSDK2018_1\TestMQTT02\Debug/../src/main.c:77: undefined reference to `mqtt_publish'
./src/main.o: In function `mqtt_connection_cb':
workspaceSDK2018_1\TestMQTT02\Debug/../src/main.c:153: undefined reference to `mqtt_set_inpub_callback'
workspaceSDK2018_1\TestMQTT02\Debug/../src/main.c:157: undefined reference to `mqtt_sub_unsub'
./src/main.o: In function `example_do_connect':
workspaceSDK2018_1\TestMQTT02\Debug/../src/main.c:193: undefined reference to `mqtt_client_connect'
collect2.exe: error: ld returned 1 exit status
make: *** [TestMQTT02.elf] Fehler 1
It seems like the Linker does not find the functions:
mqtt_publish
mqtt_set_inpub_callback
mqtt_sub_unsub
mqtt_client_connect
Does somebody has any idea, how to solve this issue?
Thx in advance
