topic Re: Infinite Loop in IGMP_ipif_unbind in MQX Software Solutions

Infinite Loop in IGMP_ipif_unbind

tduncan — Fri, 20 Feb 2015 14:51:36 GMT

This is with MQX 4.0.1 on a MK60FN1M0VMD12. The best I can tell so far is the second time the Ethernet cable is unplugged it loops on this while (ipif->IGMP_MEMBER). The first time a cable is unplugged it breaks out on an error(RTCSERR_IGMP_INVALID_IP) returned from IGMP_leave_socket_all. The second time IGMP_leave_socket_all returns RTCS_OK but does not do anything and it continues to do this looping on while (ipif->IGMP_MEMBER). I am looking to find if I can see the problem but the first time through always returning an error make this loop not do much and I am thinking of taking it out or just forcing it to run IGMP_leave_socket_all on every member of the structure.

Re: Infinite Loop in IGMP_ipif_unbind

DavidS — Fri, 20 Feb 2015 16:55:34 GMT

Hi Tim,

Any chance you can re-test on MQX4.1.1? It has updates to RTCS that might fix your issue.

If not, MQX4.2 is due out end of April with many more updates to RTCS.

Regards,

David

Re: Re: Infinite Loop in IGMP_ipif_unbind

tduncan — Fri, 20 Feb 2015 19:36:24 GMT

Not anytime soon (deadlines and all). For now I have just put an exit case

if(loopbreak_m == ipif->IGMP_MEMBER && (memcmp(&loopbreak_i, &member->IGRP, sizeof(ip_mreq))==0))

return RTCSERR_IGMP_INVALID_IP;

loopbreak_m = ipif->IGMP_MEMBER;

loopbreak_i = member->IGRP;

Re: Infinite Loop in IGMP_ipif_unbind

joesavageketra — Tue, 24 Jan 2017 21:44:26 GMT

FYI, I have run into this same problem with MQX4.2. It happens when I bind a socket to a multicast group, then unplug the ethernet cable.

The call stack looks like this:

ipcfg_unbind
ipcfg_unbind_internal
ipcfg_unbind_internal_actual
DHCPCLNT_release
DHCPCLNT_release_internal
IPIF_unbind
IGMP_ipif_unbind <----- infinite loop in here

Similar to tduncan, I have put my own exit case in the while loop.

Re: Infinite Loop in IGMP_ipif_unbind

santiago — Wed, 21 Jun 2017 16:41:41 GMT

This problem is produced when remove the IP address from route tree. After, any call of IP_find_if() function returns error.

My solution is change the order of one line into IPIF_unbind() function. First, we call the IGMP_UNBIND function pointer, and after we remove the IP address.

I have obtained good results with this solution without need of a break variable.

void IPIF_unbind
(
IPIF_PARM_PTR parms
)
{ /* Body */

#if RTCSCFG_ENABLE_IP4

_ip_address mask;

// IP_route_remove_direct(parms->address, 0xFFFFFFFF, parms->ihandle); // move this line below

#if RTCSCFG_ENABLE_IGMP
if (parms->ihandle) {
((IP_IF_PTR)(parms->ihandle))->IGMP_UNBIND((IP_IF_PTR)parms->ihandle,
parms->address);
} /* Endif */
#endif

IP_route_remove_direct(parms->address, 0xFFFFFFFF, parms->ihandle); // this line was higher

IP_get_netmask(parms->ihandle, parms->address, &mask);

/* If mask is invalid do not try to remove direct route */
if (mask != 1)
{
IP_route_remove_direct(parms->address, mask, parms->ihandle);
}
RTCSCMD_complete(parms, RTCS_OK);

#else

RTCSCMD_complete(parms, RTCSERR_IP_IS_DISABLED);

#endif /* RTCSCFG_ENABLE_IP4 */

} /* Endbody */