• Gerrit Renker's avatar
    dccp: Allow to distinguish original and retransmitted packets · 59435444
    Gerrit Renker authored
    This patch allows the sender to distinguish original and retransmitted packets,
    which is in particular needed for the retransmission of DCCP-Requests:
     * the first Request uses ISS (generated in net/dccp/ip*.c), and sets GSS = ISS;
     * all retransmitted Requests use GSS' = GSS + 1, so that the n-th retransmitted
       Request has sequence number ISS + n (mod 48).
    
    To add generic support, the patch reorganises existing code so that:
     * icsk_retransmits == 0     for the original packet and
     * icsk_retransmits = n > 0  for the n-th retransmitted packet
    at the time dccp_transmit_skb() is called, via dccp_retransmit_skb().
     
    Thanks to Wei Yongjun for pointing this problem out.
    
    Further changes:
    ----------------
     * removed the `skb' argument from dccp_retransmit_skb(), since sk_send_head
       is used for all retransmissions (the exception is client-Acks in PARTOPEN
       state, but these do not use sk_send_head);
     * since sk_send_head always contains the original skb (via dccp_entail()),
       skb_cloned() never evaluated to true and thus pskb_copy() was never used.
    Signed-off-by: default avatarGerrit Renker <gerrit@erg.abdn.ac.uk>
    59435444
timer.c 7.77 KB