Commit 0ac82784 authored by Christian Vogt's avatar Christian Vogt Committed by Daniel Stenberg
Browse files

tftp_rx: handle resends 

Re-send ACK for block X in case we receive block X data again while
waiting for block X+1.

Based on an earlier patch by Marcin Adamski.
parent c277bd6c

lib/tftp.c

+14 −4
Original line number Diff line number Diff line
@@ -591,16 +591,26 @@ static CURLcode tftp_rx(tftp_state_data_t *state, tftp_event_t event) 
  case TFTP_EVENT_DATA:

    /* Is this the block we expect? */

    rblock = getrpacketblock(&state->rpacket);

    if(NEXT_BLOCKNUM(state->block) != rblock) {

      /* No, log it */

    if( NEXT_BLOCKNUM(state->block) == rblock ) {

      /* This is the expected block.  Reset counters and ACK it. */

      state->retries = 0;

    }

    else if( state->block == rblock ) {

      /* This is the last recently received block again. Log it and ACK it again. */

      infof(data,

            "Received last DATA packet block %d again.\n",

            rblock);

    }

    else {

      /* totally unexpected, just log it */

      infof(data,

            "Received unexpected DATA packet block %d, expecting block %d\n",

            rblock, NEXT_BLOCKNUM(state->block));

      break;

    }

    /* This is the expected block.  Reset counters and ACK it. */



    /* ACK this block. */

    state->block = (unsigned short)rblock;

    state->retries = 0;

    setpacketevent(&state->spacket, TFTP_EVENT_ACK);

    setpacketblock(&state->spacket, state->block);

    sbytes = sendto(state->sockfd, (void *)state->spacket.data,