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Stand G16
________________________________________________________________________
Hi,
i'm working on a realtime-audio application, which should be capeable to
receive RTP packets via multicast addresses.
App did work fine till i switched from 2.6.22 to kernel 2.6.24 (because of
hwmon support for VIA EPIA LT15000AG)
With kernel 2.6.22 i had no problems, i'm using almost identical .config
Also tried kernel 2.6.24-rc5, same problem.
Tried it on two different boards (VIA EPIA LT, VIA EPIA 5000, diff. NIC's,
cpu's mem, etc ..)
I'm using the same setsockopt with IP_ADD_MEMBERSHIP as before for all
interfaces.
But now my app does not receive multicast packets !
Strange thing is, as long as tcpdump is running, the app (and tcpdump) get the
multicast packets, but if i stopp tcpdump, my application at the same moment
gets no more multicast packets.
I can see with netstat -g the joined MC-address (if app is active)
multicast route is set up properly.
Closer look:
-------------
Right after reboot, receiving of mc-packets worked for just one time.
After one ADD_MEMBERSHIP/DROP_MEMBERSHIP cycle it won't work any longer.
If i deny tcpdump setting promiscous-mode (-p) i get no packets.
Looks like somehow the NIC won't be (re)set to promiscous mode.
My user code:
int join_multicast_group (int fd, const char *mc_address)
{
struct ip_mreqn imr;
log_message(DVA_LOG_INFO,"In join_mc_group: %s\n",mc_address);
if (inet_aton (mc_address, &imr.imr_multiaddr) == 0) {
log_message (DVA_LOG_ERROR, "join_mc:Bad IP address format: %s\n", mc_address);
return -1;
}
imr.imr_address.s_addr = INADDR_ANY;
imr.imr_ifindex = 0;
// Check if already member
if (setsockopt (fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &imr, sizeof (imr)) < 0)
{
if (errno == EADDRINUSE) // Address already joined for IP_ADD_MEMBERSHIP
log_message(DVA_LOG_INFO,"Already joined IP_ADD_MEMBERSHIP for %s.\n",
mc_address);
else
{
log_perror (DVA_LOG_ERROR, "getsockopt ip_add_membership");
return -1;
}
}
return 0;
}
and quite the same with DROP_MEMBERSHIP before i close the socket.
Robert Reither
Research & Development
AV Digital Audio- Videotechnik GmbH
Pottendorfer Strasse 25-27/4/1/1
A-1120 Wien/Austria
Commercial Register No.: FN 201615v
Commercial Court: Handelsgericht Wien
VAT-No.: ATU 50461904
Tel.: +43/1/3680368 43
email: [EMAIL PROTECTED]
Visit: <http://www.av-digital.at>
Robert Reither
Research & Development
AV Digital Audio- Videotechnik GmbH
Pottendorfer Strasse 25-27/4/1/1
A-1120 Wien/Austria
Commercial Register No.: FN 201615v
Commercial Court: Handelsgericht Wien
VAT-No.: ATU 50461904
Tel.: +43/1/3680368 43
email: [EMAIL PROTECTED]
Visit: <http://www.av-digital.at>
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