All of lore.kernel.org
 help / color / mirror / Atom feed
* ULOG and vlans
@ 2011-07-27 18:59 Stig
  2011-07-28 11:15 ` Patrick McHardy
  0 siblings, 1 reply; 5+ messages in thread
From: Stig @ 2011-07-27 18:59 UTC (permalink / raw)
  To: netfilter-devel

I'm using ULOG iptables target to capture packets for pmacct (a
netflow exporter).  I noticed when ulog gets a packet from a vlan
interface that the ulog header shows a mac_len of 18 bytes, but it
appears that the vlan tag has already been stripped from the packet
header:

(gdb) p/x *ulog_pkt
$7 = {
  mark = 0x0,
  timestamp_sec = 0x4e2f6077,
  timestamp_usec = 0x222f3,
  hook = 0x0,
  indev_name = {0x65, 0x74, 0x68, 0x31, 0x2e, 0x31, 0x30, 0x30, 0x0, 0x0, 0x0,
    0x0, 0x0, 0x0, 0x0, 0x0},
  outdev_name = {0x0, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x5, 0xf, 0x0,
    0x0, 0x5, 0xf, 0x0, 0x0},
  data_len = 0x40,
  prefix = {0x0, 0x0, 0x2, 0x0, 0x72, 0x60, 0x2f, 0x4e, 0xed, 0x6, 0x0, 0x0,
    0xa, 0x40, 0x80, 0xfd, 0x2, 0x0, 0x0, 0x0, 0x14, 0x0, 0x1, 0x0, 0xfe,
    0x80, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},
  mac_len = 0x12,
  mac = {0x0, 0xd, 0xb9, 0x15, 0x6d, 0x1, 0x0, 0xf, 0x30, 0x4, 0x35, 0x4f,
    0x8, 0x0, 0x45, 0x0, 0x0, 0x54, 0xff, 0x21, 0x12, 0x0, 0x0, 0x21, 0x12,
    0x0, 0x0, 0x40, 0x0, 0x0, 0x0, 0x14, 0x0, 0x2, 0x0, 0x72, 0x60, 0x2f,
    0x4e, 0xed, 0x6, 0x0, 0x0, 0xa, 0x40, 0x80, 0xfd, 0x3, 0x0, 0x0, 0x0,
    0x14, 0x0, 0x1, 0x0, 0xfe, 0x80, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x2, 0xd,
    0xb9, 0xff, 0xfe, 0x15, 0x6d, 0x1, 0x14, 0x0, 0x6, 0x0, 0xff, 0xff, 0xff,
    0xff, 0xff},
  payload = 0x941cc35
}


If the vlan has been remove, shouldn't the mac_len be reduced to 14?

This causes parsing problems of the ip header for pmacct because it
does the following:

  if (ulog_pkt->mac_len) {
     	memcpy(jumbo_container, ulog_pkt->mac, ulog_pkt->mac_len);
	memcpy(jumbo_container+ulog_pkt->mac_len, ulog_pkt->payload, hdr.caplen);
	hdr.caplen += ulog_pkt->mac_len;
	hdr.len += ulog_pkt->mac_len;


Obviously I can work around it, but I'm wondering if this is the
expected behavior for ulog with vlans?

stig

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2011-07-29 18:59 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-07-27 18:59 ULOG and vlans Stig
2011-07-28 11:15 ` Patrick McHardy
2011-07-28 17:00   ` Stig
2011-07-29 14:23     ` Patrick McHardy
2011-07-29 18:59       ` Stig

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.