Hi, I recently discovered netfilter_queue, and have a question about changing the packet size before accepting it. What happens when the accepted packet is now too large and would require splitting? I have tested the following situation. Computer A filters outgoing UDP packets toward a given port and multiple by 10 their payload before accepting them. An app sends a packet from A to computer B, which is reachable through a LAN. The MTU of the corresponding ethernet devices is 1500. I sent a packet with an initial payload of 200 bytes, which is correctly multiplied by 10 by my filter callback, and gives a single IP packet of more than 2000 bytes. On computer B, I see through tcpdump that a single packet arrives, with an erroneous IP header (total length is 1500, packet is marked as fragmented), but a correct UDP header (length is 2008 bytes). The 2000 bytes of UDP payload are correctly received by the socket on computer B. How would that happen? I have seen the discussion about what may happen to a packet that is larger (http://marc.info/?l=netfilter&m=133494380818412), is this the case here? Many thanks, -- BRAMERET Pierre-Antoine -- To unsubscribe from this list: send the line "unsubscribe netfilter" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
