Hello Christian. You are trying to use the offset. It's valid only after linking. See http://ace-host.stuart.id.au/russell/files/tc/doc/cls_u32.txt for details and examples. 2014-04-10 12:57 GMT+04:00 Christian Rößner <cr@xxxxxxx>: > Hi, > > this is my first post to this list. > > I try to match several RTPv2 codecs with tc u32 and I ended up with the following: > > tc filter add dev mydevice protocol ip parent 1:0 pref 3 u32 \ > match ip protocol 0x11 0xFF \ > match u16 0x8008 0xC07F at 28 \ > flowid 1:110 > > So far this works. It means (at least I hope so): > > - match UDP, > - match the first two bytes in the UDP payload, which are part of the RTP header > - first two bits say „version 2“ RTP > - last 7 bits encode the codec. In this example G.711 PCMA > > So now this code is just working for IPv4. And I would like to have a more generic one using nexthdr. So I tried: > > tc filter add dev mydevice protocol ip parent 1:0 pref 3 u32 \ > match ip protocol 0x11 0xFF \ > match u16 0x8008 0xC07F at nexthdr+4 \ > flowid 1:110 > > Problem with this is that it matches packets, but when doing a test call with VoIP I can see that it does not match RTP traffic but some wrong traffic. So I guess my „nexthdr+4“ is wrong. I thought that the nexthdr depends on the selector u16 and therefor needs to be 4. 4*16=64, which should be 8 bytes offset to UDP, which is the beginning of the payload, isn’t it? > > Can someone help me fixing this rule? Thanks in advance > > Kind regards > > -Christian Rößner > > -- > [*] sys4 AG > > http://sys4.de, +49 (89) 30 90 46 64 > Franziskanerstraße 15, 81669 München > > Sitz der Gesellschaft: München, Amtsgericht München: HRB 199263 > Vorstand: Patrick Ben Koetter, Marc Schiffbauer > Aufsichtsratsvorsitzender: Florian Kirstein > > -- > To unsubscribe from this list: send the line "unsubscribe lartc" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Anton. -- To unsubscribe from this list: send the line "unsubscribe lartc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
