How can I use lwIP tcp/ip stack with microcontroller stm32f4 (client)

Core: Cortex-M4

Microcontroller: stm32f407 (stm32f4 discovery board)

IP Stack: lwIP 1.4.1

I am using this microcontroller to control an automate and I want to send some information to a separate web server via a HTTP request in the form of:

" /* Include my libraries here */ #include "defines.h" #include "tm_stm32f4_delay.h" #include "tm_stm32f4_disco.h" #include "tm_stm32f4_usart.h" #include "tm_stm32f4_ethernet.h" #include "tm_stm32f4_watchdog.h" #include <stdio.h> #include <stdlib.h> #include <lwip/tcp.h> #include <tcp.h>

uint32_t tcp_send_packet(void); void tcpErrorHandler(void *arg, err_t err); err_t tcpSendCallback(void *arg, struct tcp_pcb *tpcb,u16_t len);

err_t connectCallback(void *arg, struct tcp_pcb *tpcb, err_t err);

struct tcp_pcb *testpcb;
first Function is tcp_new :

void tcp_setup(void) { uint32_t data = 0xdeadbeef; /* create an ip */ struct ip_addr ip; IP4_ADDR(&ip,192,168,1,4); //IP of my PHP server /* create the control block */ testpcb = tcp_new(); //testpcb is a global struct tcp_pcb // as defined by lwIP /* dummy data to pass to callbacks*/ tcp_arg(testpcb, &data); /* register callbacks with the pcb */ // tcp_recv(testpcb, tcpRecvCallback); tcp_sent(testpcb, tcpSendCallback); tcp_err(testpcb, tcpErrorHandler); /* now connect */
tcp_connect(testpcb, &ip, 21, connectCallback); TM_DISCO_LedOn(LED_ORANGE); }

My Callbacks :

void tcpErrorHandler(void *arg, err_t err){ TM_DISCO_LedOn(LED_BLUE); }

err_t tcpSendCallback(void *arg, struct tcp_pcb *tpcb,u16_t len) { TM_DISCO_LedOn(LED_RED); }

err_t connectCallback(void *arg, struct tcp_pcb *tpcb, err_t err) { TM_DISCO_LedOn(LED_RED);

tcp_send_packet(); return 0; }
my header :

uint32_t tcp_send_packet(void) { char *string = "SetR=01\r\n\r\n "; uint32_t len = strlen(string);

/* push to buffer */ tcp_write(testpcb, string, strlen(string), TCP_WRITE_FLAG_COPY); /* now send */ tcp_output(testpcb);

return 0; }

void lwip_init();
Main function :

int main(void) { /* Initialize system */ SystemInit(); lwip_init(); /* Initialize delay */ TM_DELAY_Init(); /* Initialize leds on board */ TM_DISCO_LedInit();

/* Initialize button */ TM_DISCO_ButtonInit();

while(1) {

tcp_setup(); } }
Clearly i'm forgetting something i just don't know what it is .( i'm using Keil arm)

thank you