Re: [lwip-users] Assertions when using DHCP when using LWIP 2.0

[Neerav Patel]

Hi again

I had a read through the pitfalls page, but still am a bit confused.

So what I have done is the following, in my own robot.c file, I have done the following:

static struct udp_pcb *robot_pcb = NULL;

static void

robot_receive( void *arg, struct udp_pcb *pcb, struct pbuf *p,

              ip_addr_t *rip, u16_t rport )

{

       printf( "We received a packet\n" );

       pbuf_free(p)

}

void robot_init (

   struct udp_pcb *pcb = udp_new();

   if( pcb != NULL )

   {

      udp_bind( pcb, IP_ADDR_ANY, 50000 );

      udp_recv( pcb, robot_receive, NULL );

      robot_pcb = pcb;

   }

In my main loop where I initialize dhcp_start etc.  I add robot_init(); and that is when I get:

Assertion "dhcp_create_msg: dhcp->p_out == NULL" failed at line 1774 in src/core/ipv4/dhcp.c

Assertion "dhcp_create_msg: dhcp->msg_out == NULL" failed at line 1775 in src/core/ipv4/dhcp.c

I havent received a packet yet, so it cant be the callback, it has to be the init code.  What would I need to change on the init code to allow this to work with lwip OS Mode.

Do I have to add a critical section when initializing?  I tried disabling interrupts but the problem still prints out.

Thanks for all the help, it has been very informative.

---

From: lwip-users <lwip-users-bounces+address@hidden> on behalf of Dirk Ziegelmeier <address@hidden>
Sent: January 23, 2017 7:23 PM
To: Mailing list for lwIP users
Subject: Re: [lwip-users] Assertions when using DHCP when using LWIP 2.0

 

And read this:

http://www.nongnu.org/lwip/2_0_0/pitfalls.html

lwIP: Common pitfalls - nongnu.org

www.nongnu.org

The most common source of lwIP problems is to have multiple execution contexts inside the lwIP code. lwIP can be used in two basic modes: Mainloop mode ("NO_SYS") (no ...

Dirk