lwip init network interfaces

Questions » lwip init network interfaces

Nickita Lebedev

9 years, 9 months ago.

Good day!

I want to make a client and connect it to netcat simple server.

1) Compilled lib with default settings and #define's (the only thing - i set some debug information on) 2) Linked lib to the project (works fine) 3) Set up virtual machine with ubuntu and made netcat working with

~$ sudo netcat -l -v 7

that means we are listening to port 7 (seven).

now I use ifconfig and get

inet addr:172.17.9.71 
Bcast:172.17.11.255 
Mask:255.255.252.0

fine for now.

4) ping and telnet work fine - I see that netcat is reachable by them .

my ifconfig stats are

inet addr:172.17.9.165 
Bcast:172.17.11.255 
Mask:255.255.252.0

5) Now I'm trying to connect to netcat server with my client, written by using lwip

output is :

LWIP_HAVE_LOOPIF = 0 
LWIP_HAVE_LOOPIF = 0 
tcp_bind: bind to port 55555 
tcp_connect to port 7 
netif_default =  -780756800 
 netif_is_up(netif_default) =  0 
 ip_route: No route to 172.17.9.71 
connect err =  -4 
netif_default =  -780756800 
 netif_is_up(netif_default) =  0 
 ip_route: No route to 172.17.9.71 
ip_output: No route to 172.17.9.71 
Assertion "mem_free: mem->used" failed at line 339 in ../../../../../lwip/src/core/mem.c

the full listing :

const char *helloworld = "hello world\n"; 



void hello_end(struct tcp_pcb *pcb, u8_t *state) 
{ 
 tcp_err(pcb, NULL); 
 tcp_recv(pcb, NULL); 
 tcp_sent(pcb, NULL); 
 tcp_poll(pcb, NULL, 0); 
 mem_free(state); 
} 
err_t hello_recv(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err) 
{ 
 u8_t *state = (u8_t *)arg; 
 u16_t len; 

 if (p == NULL) 
 if (*state == 255) /* close send */ 
 hello_end(pcb, state); 
 else /* close not yet send */ 
 *state |= 2; 
 else 
 { 
 len = p->tot_len; 
 pbuf_free(p); 
 tcp_recved(pcb, len); 
 } 

 return ERR_OK; 
} 

void hello_err(void *arg, err_t err) 
{ 
 mem_free(arg); 
} 

err_t hello_poll_close(void *arg, struct tcp_pcb *pcb) 
{ 
 u8_t *state = (u8_t *)arg; 

 if (tcp_close(pcb) == ERR_OK) 
 { 
 if ((*state & 2) == 2) /* close received */ 
 hello_end(pcb, state); 
 else /* close not yet received */ 
 *state = 255; 
 } 

 return ERR_OK; 
} 

err_t hello_connected(void *arg, struct tcp_pcb *pcb, err_t err) 
{ 
 tcp_write(pcb, helloworld, 12, 0); 
 return ERR_OK; 
} 

err_t hello_connect() { 

        lwip_init(); 
        u8_t *state; 
        err_t err; 
        struct tcp_pcb *pcb; 
        ip_addr_t ipaddr; 

          IP4_ADDR(&ipaddr, 172,17,9,71); 
          if ((state = mem_malloc(1)) == NULL)  { 
             return ERR_MEM; 
          } 
        
           *state = 1; 
           if ((pcb = tcp_new()) == NULL)  { 
           mem_free(state); 
           return ERR_MEM; 
          } 

          tcp_arg(pcb, state); 
          tcp_err(pcb, hello_err); 
          tcp_recv(pcb, hello_recv); 
          tcp_sent(pcb, NULL); 
          tcp_poll(pcb, hello_poll_close, 10); 





          tcp_bind(pcb,IPADDR_ANY, 55555); //Bind ourselvs to the port 55555 and my own adress 


          err = tcp_connect(pcb, &ipaddr, 7, hello_connected); 
          if (err != ERR_OK)  { 
             std::cout << "connect err =  " << (int)err << std::endl; 
            mem_free(state); 
             tcp_abort(pcb); 
        } 

          getchar(); 
          return ERR_OK; 
} 

int main(int argc, char** argv) { 

         err_t err =  hello_connect(); 
           if (err != ERR_OK)  { 
           std::cout << "2err =  " << err << std::endl; 
           } 
            std::cout << "End of Main" << std::endl; 
            return 0; 


        return 0; 
}

from here I started to think that the problem is that I didnt set up NETIF.

but I don't know HOW.

I think I don't want lwip to create tap0 by default

(it makes

tap0      Link encap:Ethernet  HWaddr 86:97:2c:64:b7:78   
          inet addr:192.168.1.1  Bcast:192.168.1.255  Mask:255.255.255.0 
          inet6 addr: fe80::8497:2cff:fe64:b778/64 Scope:Link 
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1 
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0 
          TX packets:33 errors:0 dropped:0 overruns:0 carrier:0 
          collisions:0 txqueuelen:500 
          RX bytes:0 (0.0 B)  TX bytes:6555 (6.4 KiB)

)

I want to bind my application to localhost or to eth1 - whatever... How can I do this? What do I do wrong in my application?

By the way - when I do

  char *eth = "eht1"; 
  netif_set_default(netif_find(eth));

In my Init function I get this output

LWIP_HAVE_LOOPIF = 0 
LWIP_HAVE_LOOPIF = 0 
tcpip_thread: PACKET 0x7f72acaa1988 
ip_input: packet not for us. 
tcp_bind: bind to port 55555 
tcp_connect to port 7 
netif_default =  0

and it falls on

 err = tcp_connect(pcb, &ipaddr, 7, hello_connected);

(not passing it...)

Can some 1 help?

Be the first to answer this question.

Nickita Lebedev

Important changes to forums and questions

9 years, 9 months ago.