I've run into what may be a problem with IP Fragmentation when combined with TCP Retransmit in lwip 1.1.1 (I'm not sure if this problem exists in 1.2).
It seems that ip_frag (via copy_from_pbuf) modifies the pbuf given to it. During normal operation this is fine; it causes problems when TCP tries to retransmit a segment that has already been fragmented. In that case the pbuf's len and payload pointers will be incorrect (thanks to the first call to ip_frag) and this can cause errors during the *second* call to ip_frag. I'm not quite sure what the correct solution is. Either a copy of the pbuf chain could be made (minus the payloads) or copy_from_pbuf could be modified so as not to change the state of the pbuf (or at least restore it once it's done). Thoughts? Thanks, Tom Hennen _______________________________________________ lwip-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/lwip-users
