[lwip-users] 2 Interfaces , PPP over Serial and Ethernet

[nkarakotas]

Hello,

 

I have system with an ethernet and a GSM modem on. The application involves uploading remotely through the PPP connection and ethernet usually to access the web application. I have a problem when running the two interfaces together. Separately they run ok. Initialy I bring up the ethernet and add it as the default interface. Then I connect to the ISP via PPP. Its all ok and it adds the interface pp.

I then try to netconn_gethostbyname(). I get a fault in the ip.c file at ip_route function:

 

It searches for the appropriate interface it finds pp which is up but doesn’t meet the following condition:

if (ip_addr_netcmp(dest, &(netif->ip_addr), &(netif->netmask))) {

}

 

Afterwards it iterates the list and the weird thing is that it doesn’t find em interface. Then netif –>next should be 0x0 but is 0xfffffff. This makes me think of some overflow or stack problem. I don’t really know where to look any help would be appreciated!

 

struct netif *

ip_route(ip_addr_t *dest)

{

  struct netif *netif;

 

  /* iterate through netifs */

  for(netif = netif_list; netif != NULL; netif = netif->next) {

    /* network mask matches? */

    if (netif_is_up(netif)) {

      if (ip_addr_netcmp(dest, &(netif->ip_addr), &(netif->netmask))) {

        /* return netif on which to forward IP packet */

        return netif;

      }

    }

  }

 

.....

 

 

}

 

Regards,

Nick