I'm having some trouble with pbuf_take and ip_frag and I was wondering if I'm using pbuf_take incorrectly.
Currently my netif_output calls pbuf_take as it places the packets on a queue to be sent later.
// netif_output pseudo-code
err_t netif_output(struct pbuf * p)
{
p = pbuf_take(p)
if (p) {
pbuf_ref(p);
queue(p);
return ERR_OK;
}
return ERR_MEM;
}
This seems to work fine until pbuf_take can't allocate the pbuf's nessecary to copy the referenced data.
When pbuf_take can't allocate the referenced data it frees the pbuf passed to it and returns NULL.
When ip_frag calls netif_output 'header' has a ref-count of 1. Then, netif_output tries to take the packet but fails, causing header to have a ref-count of 0 (though the rambuf still has a ref-count of 1). ip_frag does not check the return value of netif_output to see if it succeeded or not, it simply tries to free header (at line 357). Of coures at this point header has a ref-count of 0 and so pbuf_free asserts.
So, do I need to call pbuf_ref before calling pbuf_take or am I correct in calling it after? If I'm doing it correctly, how can I prevent this assertion from occuring?
Thanks,
Tom
_______________________________________________ lwip-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/lwip-users
