implement random packet drop option, fix retransmission logic

[oweals/gnunet.git] / src / cadet / gnunet-service-cadet-new_channel.c

diff --git a/src/cadet/gnunet-service-cadet-new_channel.c b/src/cadet/gnunet-service-cadet-new_channel.c
index 29ad732b076b23e353a6907a0df773449f793283..a923f19dce778099f518faace365b6564de8616a 100644 (file)
--- a/src/cadet/gnunet-service-cadet-new_channel.c
+++ b/src/cadet/gnunet-service-cadet-new_channel.c
@@ -26,11 +26,18 @@
  *
  * TODO:
  * - Optimize ACKs by using 'mid_futures' properly!
+ * - calculate current RTT if possible, use that for initial retransmissions
+ *   (NOTE: needs us to learn which connection the tunnel uses for the message!)
  * - introduce shutdown so we can have half-closed channels, modify
  *   destroy to include MID to have FIN-ACK equivalents, etc.
  * - estimate max bandwidth using bursts and use to for CONGESTION CONTROL!
+ *   (and figure out how/where to use this!)
  * - check that '0xFFULL' really is sufficient for flow control!
+ *   (this is right now a big HACK!)
  * - revisit handling of 'unreliable' traffic!
+ *   (has not seen enough review)
+ * - revisit handling of 'unbuffered' traffic!
+ *   (has not seen enough review)
  * - revisit handling of 'out-of-order' option, especially in combination with/without 'reliable'.
  * - figure out flow control without ACKs (unreliable traffic!)
  */
@@ -861,9 +868,16 @@ send_ack_to_client (struct CadetChannel *ch,
   struct GNUNET_CADET_LocalAck *ack;
   struct CadetChannelClient *ccc;
 
+  ccc = (GNUNET_YES == to_owner) ? ch->owner : ch->dest;
+  if (NULL == ccc)
+  {
+    /* This can happen if we are just getting ACKs after
+       our local client already disconnected. */
+    GNUNET_assert (GNUNET_YES == ch->destroy);
+    return;
+  }
   env = GNUNET_MQ_msg (ack,
                        GNUNET_MESSAGE_TYPE_CADET_LOCAL_ACK);
-  ccc = (GNUNET_YES == to_owner) ? ch->owner : ch->dest;
   ack->ccn = ccc->ccn;
   LOG (GNUNET_ERROR_TYPE_DEBUG,
        "Sending CADET_LOCAL_ACK to %s (%s) at ccn %X (%u/%u pending)\n",
@@ -1176,6 +1190,8 @@ GCCH_handle_channel_plaintext_data (struct CadetChannel *ch,
                               1,
                               GNUNET_NO);
     GNUNET_MQ_discard (env);
+    if (GNUNET_YES == ch->reliable)
+      send_channel_data_ack (ch);
     return;
   }
 
@@ -1334,16 +1350,38 @@ GCCH_handle_channel_plaintext_data_ack (struct CadetChannel *ch,
     crmn = crm->next;
     if (ack->mid.mid == crm->data_message->mid.mid)
     {
+      LOG (GNUNET_ERROR_TYPE_DEBUG,
+           "Got DATA_ACK with base %u matching message %u on %s\n",
+           (unsigned int) mid_base,
+           ntohl (crm->data_message->mid.mid),
+           GCCH_2s (ch));
       handle_matching_ack (ch,
                            crm);
       found = GNUNET_YES;
       continue;
     }
     delta = (unsigned int) (ntohl (crm->data_message->mid.mid) - mid_base) - 1;
+    if (delta >= UINT_MAX - ch->max_pending_messages)
+    {
+      /* overflow, means crm was way in the past, so this ACK counts for it. */
+      LOG (GNUNET_ERROR_TYPE_DEBUG,
+           "Got DATA_ACK with base %u past %u on %s\n",
+           (unsigned int) mid_base,
+           ntohl (crm->data_message->mid.mid),
+           GCCH_2s (ch));
+      handle_matching_ack (ch,
+                           crm);
+      found = GNUNET_YES;
+      continue;
+    }
     if (delta >= 64)
       continue;
     if (0 != (mid_mask & (1LLU << delta)))
     {
+      LOG (GNUNET_ERROR_TYPE_DEBUG,
+           "Got DATA_ACK with mask for %u on %s\n",
+           ntohl (crm->data_message->mid.mid),
+           GCCH_2s (ch));
       handle_matching_ack (ch,
                            crm);
       found = GNUNET_YES;
@@ -1432,6 +1470,7 @@ cmp_crm_by_next_retry (void *cls,
   return GNUNET_NO;
 }
 
+
 /**
  * Function called once the tunnel has sent one of our messages.
  * If the message is unreliable, simply frees the `crm`. If the
@@ -1483,9 +1522,8 @@ data_sent_cb (void *cls)
        GCCH_2s (ch),
        GNUNET_STRINGS_relative_time_to_string (GNUNET_TIME_absolute_get_remaining (ch->head_sent->next_retry),
                                                GNUNET_YES));
-  if (crm == ch->head_sent)
+  if (NULL == ch->head_sent->qe)
   {
-    /* We are the new head, need to reschedule retry task */
     if (NULL != ch->retry_data_task)
       GNUNET_SCHEDULER_cancel (ch->retry_data_task);
     ch->retry_data_task
@@ -1683,7 +1721,7 @@ GCCH_handle_local_ack (struct CadetChannel *ch,
   }
 
   LOG (GNUNET_ERROR_TYPE_DEBUG,
-       "Got LOCAL ACK, passing payload message %u to %s-%X on %s\n",
+       "Got LOCAL_ACK, passing payload message %u to %s-%X on %s\n",
        ntohl (com->mid.mid),
        GSC_2s (ccc->c),
        ntohl (ccc->ccn.channel_of_client),