Didier:
All the incidents I sent you were TCP irregular chain.
>> But the rohc packet has no data after the timestamp (0x08). So, a
>> call to the tcp_opt_sack routine returns the ptr having been advanced,
>> but no processing of the sack option is done, because the
>> discriminator value is 0.
>I'm afraid I don't understand you well. The irregular encoding of the
>timestamp option cannot be 0-byte length (it may encoded from 2 to 8 bytes).
>And, why the tcp_opt_sack routine >read some ROHC bytes? Did you mean the
>tcp_opt_ts routine instead?
I think the timestamp field is OK. We have an rohc_packet going into the
routine tcp_irregular_tcp. The routine processes the remaining data according
to the current option list.
The remaining data itself is done after the 10 bytes of timestamp, but the
option list continues. Below is the exact option list when this problem occurs:
0x01 0x01 0x08 0x01 0x01 0x05 0xff 0xff
0xff 0xff 0xff 0xff 0xff 0xff 0xff 0xff
So, after processing NO-OP's (0x01 0x01), then the 10 bytes of timestamp
(0x08). At that point, there is nothing in the remain_data. But the routine
sees the
0x01 0x05 in the option list and does a NO-OP and then, for 0x05, calls the
tcp_opt_sack routine. In the tcp_opt_sack_routine, the first byte of the
remain_data
is checked as discriminator. But this is really the end of remain_data and the
discriminator is 0. Then the ptr is advanced by one. When the ptr is
returned, the
length is actually advanced beyond the roch_packet, eventually causing an
assertion. I think either the call to tcp_opt_sack, or the routine itself
should check the
remain_data length before advancing the ptr. However, this should not happen
at all, if the option list is consistent with the rohc_packet. With this
packet, the
option list should just be
0x01 0x01 0x08 0x01 0xff 0xff 0xff 0xff
0xff 0xff 0xff 0xff 0xff 0xff 0xff 0xff
Thanks and kind regards,
TW
_______________________________________________
Mailing list: https://launchpad.net/~rohc
Post to : [email protected]
Unsubscribe : https://launchpad.net/~rohc
More help : https://help.launchpad.net/ListHelp
