Bugzilla Bug 196904

Needed for things like
http://sourceforge.net/projects/opennhrp/

Patch is accepted upstream.

Created an attachment (id=134212) [details]
ipgre_nbma-2.6.22.patch

Would be nice to get this backport into genpatches.

So have you tested this patch with a 2.6.22 kernel yourself? Can you confirm it
works? If so, we can put this into genpatches.

Yes I have tested. It applies, kernel compiles and it does what it is supposed
to do. To reproduce, create an gre tunnel in NBMA mode (omit the "remote" ip
addr), ping the tunnel ip from a remote machine and run tshark on recieving
computer. Look for the link layer source address (under Linux cooked capture).

On an unpatched kernel:
Linux cooked capture
    Packet type: Unicast to us (0)
    Link-layer address type: 778
    Link-layer address length: 0
    Source: <MISSING>
    Protocol: IP (0x0800)


Note that the Source is reported as <MISSING>

with a patched kernel:

Linux cooked capture
     Packet type: Sent by us (4)
     Link-layer address type: 778
     Link-layer address length: 4
     Source: C0A841EA
     Protocol: IP (0x0800)

Source is C0 a8 41 ea and the public ip (NMBA) address for the tunnel happens
to be 192.168.65.234.

(tcpdump will not display the linklayer source address but running strace will
show that rcvfrom actually gets the NMBA addess:

recvfrom(3, "E\0\0TR\27\0\0@\1\1\17\nA\t\1\nA\n\1\0\0,01<\2\37\312@"..., 80,
MSG_TRUNC, {sa_family=AF_PACKET, proto=0x800, if7, pkttype=PACKET_OUTGOING,
addr(4)={778, c0a841ea}, [16]) = 84)

So yes, it works!

Patch applies on a 2.6.23 kernel as well (and kerne compiles) but i havent set
up the gre tunnel on 2.6.23. Author of patch (Timo) claims it works on 2.6.23.
Do you want me to test it on 2.6.23 too?

Thanks for testing the patch with 2.6.22. Testing with 2.6.23 is not necessary,
we'll wait until the patch hits Linus' tree and then we'll backport it to
genpatches.

(In reply to comment #4)
> we'll wait until the patch hits Linus' tree and then we'll backport it to
> genpatches.

It is in Linus' tree
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=6a5f44d7a048c97b8bae8ce464c97b8fad61ff99

The patch has been committed to genpatches. We'll keep this bug open until the
next version of gentoo-sources has been released.

Please note that genpatches-2.6.23-2 has been released with this patch
included, gentoo-sources-2.6.23-r1 is using it.

also fixed in gentoo-sources-2.6.22-r10