10 files changed, 199 insertions, 209 deletions

diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index c39bff706cfc..090bc39e8199 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -2,7 +2,7 @@
  *  net/dccp/ccids/ccid3.c
  *
  *  Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
- *  Copyright (c) 2005-6 Ian McDonald <imcdnzl@gmail.com>
+ *  Copyright (c) 2005-6 Ian McDonald <ian.mcdonald@jandi.co.nz>
  *
  *  An implementation of the DCCP protocol
  *
@@ -342,6 +342,8 @@ static int ccid3_hc_tx_send_packet(struct sock *sk,
                 new_packet->dccphtx_ccval =
                         DCCP_SKB_CB(skb)->dccpd_ccval =
                                 hctx->ccid3hctx_last_win_count;
+                timeval_add_usecs(&hctx->ccid3hctx_t_nom,
+                                  hctx->ccid3hctx_t_ipi);
         }
 out:
         return rc;
@@ -413,7 +415,8 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, int len)
         case TFRC_SSTATE_NO_FBACK:
         case TFRC_SSTATE_FBACK:
                 if (len > 0) {
-                        hctx->ccid3hctx_t_nom = now;
+                        timeval_sub_usecs(&hctx->ccid3hctx_t_nom,
+                                  hctx->ccid3hctx_t_ipi);
                         ccid3_calc_new_t_ipi(hctx);
                         ccid3_calc_new_delta(hctx);
                         timeval_add_usecs(&hctx->ccid3hctx_t_nom,
@@ -757,8 +760,7 @@ static void ccid3_hc_rx_send_feedback(struct sock *sk)
         }
 
         hcrx->ccid3hcrx_tstamp_last_feedback = now;
-        hcrx->ccid3hcrx_last_counter         = packet->dccphrx_ccval;
-        hcrx->ccid3hcrx_seqno_last_counter   = packet->dccphrx_seqno;
+        hcrx->ccid3hcrx_ccval_last_counter   = packet->dccphrx_ccval;
         hcrx->ccid3hcrx_bytes_recv           = 0;
 
         /* Convert to multiples of 10us */
@@ -782,7 +784,7 @@ static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb)
         if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN))
                 return 0;
 
-        DCCP_SKB_CB(skb)->dccpd_ccval = hcrx->ccid3hcrx_last_counter;
+        DCCP_SKB_CB(skb)->dccpd_ccval = hcrx->ccid3hcrx_ccval_last_counter;
 
         if (dccp_packet_without_ack(skb))
                 return 0;
@@ -854,6 +856,11 @@ static u32 ccid3_hc_rx_calc_first_li(struct sock *sk)
                 interval = 1;
         }
 found:
+        if (!tail) {
+                LIMIT_NETDEBUG(KERN_WARNING "%s: tail is null\n",
+                   __FUNCTION__);
+                return ~0;
+        }
         rtt = timeval_delta(&tstamp, &tail->dccphrx_tstamp) * 4 / interval;
         ccid3_pr_debug("%s, sk=%p, approximated RTT to %uus\n",
                        dccp_role(sk), sk, rtt);
@@ -864,9 +871,20 @@ found:
         delta = timeval_delta(&tstamp, &hcrx->ccid3hcrx_tstamp_last_feedback);
         x_recv = usecs_div(hcrx->ccid3hcrx_bytes_recv, delta);
 
+        if (x_recv == 0)
+                x_recv = hcrx->ccid3hcrx_x_recv;
+
         tmp1 = (u64)x_recv * (u64)rtt;
         do_div(tmp1,10000000);
         tmp2 = (u32)tmp1;
+
+        if (!tmp2) {
+                LIMIT_NETDEBUG(KERN_WARNING "tmp2 = 0 "
+                   "%s: x_recv = %u, rtt =%u\n",
+                   __FUNCTION__, x_recv, rtt);
+                return ~0;
+        }
+
         fval = (hcrx->ccid3hcrx_s * 100000) / tmp2;
         /* do not alter order above or you will get overflow on 32 bit */
         p = tfrc_calc_x_reverse_lookup(fval);
@@ -882,31 +900,101 @@ found:
 static void ccid3_hc_rx_update_li(struct sock *sk, u64 seq_loss, u8 win_loss)
 {
         struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
+        struct dccp_li_hist_entry *next, *head;
+        u64 seq_temp;
 
-        if (seq_loss != DCCP_MAX_SEQNO + 1 &&
-            list_empty(&hcrx->ccid3hcrx_li_hist)) {
-                struct dccp_li_hist_entry *li_tail;
+        if (list_empty(&hcrx->ccid3hcrx_li_hist)) {
+                if (!dccp_li_hist_interval_new(ccid3_li_hist,
+                   &hcrx->ccid3hcrx_li_hist, seq_loss, win_loss))
+                        return;
 
-                li_tail = dccp_li_hist_interval_new(ccid3_li_hist,
-                                                    &hcrx->ccid3hcrx_li_hist,
-                                                    seq_loss, win_loss);
-                if (li_tail == NULL)
+                next = (struct dccp_li_hist_entry *)
+                   hcrx->ccid3hcrx_li_hist.next;
+                next->dccplih_interval = ccid3_hc_rx_calc_first_li(sk);
+        } else {
+                struct dccp_li_hist_entry *entry;
+                struct list_head *tail;
+
+                head = (struct dccp_li_hist_entry *)
+                   hcrx->ccid3hcrx_li_hist.next;
+                /* FIXME win count check removed as was wrong */
+                /* should make this check with receive history */
+                /* and compare there as per section 10.2 of RFC4342 */
+
+                /* new loss event detected */
+                /* calculate last interval length */
+                seq_temp = dccp_delta_seqno(head->dccplih_seqno, seq_loss);
+                entry = dccp_li_hist_entry_new(ccid3_li_hist, SLAB_ATOMIC);
+
+                if (entry == NULL) {
+                        printk(KERN_CRIT "%s: out of memory\n",__FUNCTION__);
+                        dump_stack();
                         return;
-                li_tail->dccplih_interval = ccid3_hc_rx_calc_first_li(sk);
-        } else
-                    LIMIT_NETDEBUG(KERN_WARNING "%s: FIXME: find end of "
-                                   "interval\n", __FUNCTION__);
+                }
+
+                list_add(&entry->dccplih_node, &hcrx->ccid3hcrx_li_hist);
+
+                tail = hcrx->ccid3hcrx_li_hist.prev;
+                list_del(tail);
+                kmem_cache_free(ccid3_li_hist->dccplih_slab, tail);
+
+                /* Create the newest interval */
+                entry->dccplih_seqno = seq_loss;
+                entry->dccplih_interval = seq_temp;
+                entry->dccplih_win_count = win_loss;
+        }
 }
 
-static void ccid3_hc_rx_detect_loss(struct sock *sk)
+static int ccid3_hc_rx_detect_loss(struct sock *sk,
+                                    struct dccp_rx_hist_entry *packet)
 {
         struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
-        u8 win_loss;
-        const u64 seq_loss = dccp_rx_hist_detect_loss(&hcrx->ccid3hcrx_hist,
-                                                      &hcrx->ccid3hcrx_li_hist,
-                                                      &win_loss);
+        struct dccp_rx_hist_entry *rx_hist = dccp_rx_hist_head(&hcrx->ccid3hcrx_hist);
+        u64 seqno = packet->dccphrx_seqno;
+        u64 tmp_seqno;
+        int loss = 0;
+        u8 ccval;
+
+
+        tmp_seqno = hcrx->ccid3hcrx_seqno_nonloss;
+
+        if (!rx_hist ||
+           follows48(packet->dccphrx_seqno, hcrx->ccid3hcrx_seqno_nonloss)) {
+                hcrx->ccid3hcrx_seqno_nonloss = seqno;
+                hcrx->ccid3hcrx_ccval_nonloss = packet->dccphrx_ccval;
+                goto detect_out;
+        }
+
 
-        ccid3_hc_rx_update_li(sk, seq_loss, win_loss);
+        while (dccp_delta_seqno(hcrx->ccid3hcrx_seqno_nonloss, seqno)
+           > TFRC_RECV_NUM_LATE_LOSS) {
+                loss = 1;
+                ccid3_hc_rx_update_li(sk, hcrx->ccid3hcrx_seqno_nonloss,
+                   hcrx->ccid3hcrx_ccval_nonloss);
+                tmp_seqno = hcrx->ccid3hcrx_seqno_nonloss;
+                dccp_inc_seqno(&tmp_seqno);
+                hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno;
+                dccp_inc_seqno(&tmp_seqno);
+                while (dccp_rx_hist_find_entry(&hcrx->ccid3hcrx_hist,
+                   tmp_seqno, &ccval)) {
+                        hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno;
+                        hcrx->ccid3hcrx_ccval_nonloss = ccval;
+                        dccp_inc_seqno(&tmp_seqno);
+                }
+        }
+
+        /* FIXME - this code could be simplified with above while */
+        /* but works at moment */
+        if (follows48(packet->dccphrx_seqno, hcrx->ccid3hcrx_seqno_nonloss)) {
+                hcrx->ccid3hcrx_seqno_nonloss = seqno;
+                hcrx->ccid3hcrx_ccval_nonloss = packet->dccphrx_ccval;
+        }
+
+detect_out:
+        dccp_rx_hist_add_packet(ccid3_rx_hist, &hcrx->ccid3hcrx_hist,
+                   &hcrx->ccid3hcrx_li_hist, packet,
+                   hcrx->ccid3hcrx_seqno_nonloss);
+        return loss;
 }
 
 static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
@@ -916,8 +1004,8 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
         struct dccp_rx_hist_entry *packet;
         struct timeval now;
         u8 win_count;
-        u32 p_prev, r_sample, t_elapsed;
-        int ins;
+        u32 p_prev, rtt_prev, r_sample, t_elapsed;
+        int loss;
 
         BUG_ON(hcrx == NULL ||
                !(hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA ||
@@ -932,7 +1020,7 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
         case DCCP_PKT_DATAACK:
                 if (opt_recv->dccpor_timestamp_echo == 0)
                         break;
-                p_prev = hcrx->ccid3hcrx_rtt;
+                rtt_prev = hcrx->ccid3hcrx_rtt;
                 dccp_timestamp(sk, &now);
                 timeval_sub_usecs(&now, opt_recv->dccpor_timestamp_echo * 10);
                 r_sample = timeval_usecs(&now);
@@ -951,8 +1039,8 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
                         hcrx->ccid3hcrx_rtt = (hcrx->ccid3hcrx_rtt * 9) / 10 +
                                               r_sample / 10;
 
-                if (p_prev != hcrx->ccid3hcrx_rtt)
-                        ccid3_pr_debug("%s, New RTT=%luus, elapsed time=%u\n",
+                if (rtt_prev != hcrx->ccid3hcrx_rtt)
+                        ccid3_pr_debug("%s, New RTT=%uus, elapsed time=%u\n",
                                        dccp_role(sk), hcrx->ccid3hcrx_rtt,
                                        opt_recv->dccpor_elapsed_time);
                 break;
@@ -973,8 +1061,7 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
 
         win_count = packet->dccphrx_ccval;
 
-        ins = dccp_rx_hist_add_packet(ccid3_rx_hist, &hcrx->ccid3hcrx_hist,
-                                      &hcrx->ccid3hcrx_li_hist, packet);
+        loss = ccid3_hc_rx_detect_loss(sk, packet);
 
         if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK)
                 return;
@@ -991,7 +1078,7 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
         case TFRC_RSTATE_DATA:
                 hcrx->ccid3hcrx_bytes_recv += skb->len -
                                               dccp_hdr(skb)->dccph_doff * 4;
-                if (ins != 0)
+                if (loss)
                         break;
 
                 dccp_timestamp(sk, &now);
@@ -1012,7 +1099,6 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
         ccid3_pr_debug("%s, sk=%p(%s), data loss! Reacting...\n",
                        dccp_role(sk), sk, dccp_state_name(sk->sk_state));
 
-        ccid3_hc_rx_detect_loss(sk);
         p_prev = hcrx->ccid3hcrx_p;
         
         /* Calculate loss event rate */
@@ -1022,6 +1108,9 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
                 /* Scaling up by 1000000 as fixed decimal */
                 if (i_mean != 0)
                         hcrx->ccid3hcrx_p = 1000000 / i_mean;
+        } else {
+                printk(KERN_CRIT "%s: empty loss hist\n",__FUNCTION__);
+                dump_stack();
         }
 
         if (hcrx->ccid3hcrx_p > p_prev) {
@@ -1230,7 +1319,7 @@ static __exit void ccid3_module_exit(void)
 }
 module_exit(ccid3_module_exit);
 
-MODULE_AUTHOR("Ian McDonald <iam4@cs.waikato.ac.nz>, "
+MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>, "
               "Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
 MODULE_DESCRIPTION("DCCP TFRC CCID3 CCID");
 MODULE_LICENSE("GPL");
diff --git a/net/dccp/ccids/ccid3.h b/net/dccp/ccids/ccid3.h
index 5ade4f668b22..0a2cb7536d26 100644
--- a/net/dccp/ccids/ccid3.h
+++ b/net/dccp/ccids/ccid3.h
@@ -1,13 +1,13 @@
 /*
  *  net/dccp/ccids/ccid3.h
  *
- *  Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
+ *  Copyright (c) 2005-6 The University of Waikato, Hamilton, New Zealand.
  *
  *  An implementation of the DCCP protocol
  *
  *  This code has been developed by the University of Waikato WAND
  *  research group. For further information please see http://www.wand.net.nz/
- *  or e-mail Ian McDonald - iam4@cs.waikato.ac.nz
+ *  or e-mail Ian McDonald - ian.mcdonald@jandi.co.nz
  *
  *  This code also uses code from Lulea University, rereleased as GPL by its
  *  authors:
@@ -120,9 +120,10 @@ struct ccid3_hc_rx_sock {
 #define ccid3hcrx_x_recv        ccid3hcrx_tfrc.tfrcrx_x_recv
 #define ccid3hcrx_rtt           ccid3hcrx_tfrc.tfrcrx_rtt
 #define ccid3hcrx_p             ccid3hcrx_tfrc.tfrcrx_p
-        u64                     ccid3hcrx_seqno_last_counter:48,
+        u64                     ccid3hcrx_seqno_nonloss:48,
+                                ccid3hcrx_ccval_nonloss:4,
                                 ccid3hcrx_state:8,
-                                ccid3hcrx_last_counter:4;
+                                ccid3hcrx_ccval_last_counter:4;
         u32                     ccid3hcrx_bytes_recv;
         struct timeval          ccid3hcrx_tstamp_last_feedback;
         struct timeval          ccid3hcrx_tstamp_last_ack;
diff --git a/net/dccp/ccids/lib/loss_interval.c b/net/dccp/ccids/lib/loss_interval.c
index 5d7b7d864385..906c81ab9d4f 100644
--- a/net/dccp/ccids/lib/loss_interval.c
+++ b/net/dccp/ccids/lib/loss_interval.c
@@ -2,7 +2,7 @@
  *  net/dccp/ccids/lib/loss_interval.c
  *
  *  Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
- *  Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
+ *  Copyright (c) 2005-6 Ian McDonald <ian.mcdonald@jandi.co.nz>
  *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  *
  *  This program is free software; you can redistribute it and/or modify
@@ -12,6 +12,7 @@
  */
 
 #include <linux/module.h>
+#include <net/sock.h>
 
 #include "loss_interval.h"
 
@@ -90,13 +91,13 @@ u32 dccp_li_hist_calc_i_mean(struct list_head *list)
         u32 w_tot  = 0;
 
         list_for_each_entry_safe(li_entry, li_next, list, dccplih_node) {
-                if (i < DCCP_LI_HIST_IVAL_F_LENGTH) {
+                if (li_entry->dccplih_interval != ~0) {
                         i_tot0 += li_entry->dccplih_interval * dccp_li_hist_w[i];
                         w_tot  += dccp_li_hist_w[i];
+                        if (i != 0)
+                                i_tot1 += li_entry->dccplih_interval * dccp_li_hist_w[i - 1];
                 }
 
-                if (i != 0)
-                        i_tot1 += li_entry->dccplih_interval * dccp_li_hist_w[i - 1];
 
                 if (++i > DCCP_LI_HIST_IVAL_F_LENGTH)
                         break;
@@ -107,37 +108,36 @@ u32 dccp_li_hist_calc_i_mean(struct list_head *list)
 
         i_tot = max(i_tot0, i_tot1);
 
-        /* FIXME: Why do we do this? -Ian McDonald */
-        if (i_tot * 4 < w_tot)
-                i_tot = w_tot * 4;
+        if (!w_tot) {
+                LIMIT_NETDEBUG(KERN_WARNING "%s: w_tot = 0\n", __FUNCTION__);
+                return 1;
+        }
 
-        return i_tot * 4 / w_tot;
+        return i_tot / w_tot;
 }
 
 EXPORT_SYMBOL_GPL(dccp_li_hist_calc_i_mean);
 
-struct dccp_li_hist_entry *dccp_li_hist_interval_new(struct dccp_li_hist *hist,
-                                                     struct list_head *list,
-                                                     const u64 seq_loss,
-                                                     const u8 win_loss)
+int dccp_li_hist_interval_new(struct dccp_li_hist *hist,
+   struct list_head *list, const u64 seq_loss, const u8 win_loss)
 {
-        struct dccp_li_hist_entry *tail = NULL, *entry;
+        struct dccp_li_hist_entry *entry;
         int i;
 
-        for (i = 0; i <= DCCP_LI_HIST_IVAL_F_LENGTH; ++i) {
+        for (i = 0; i < DCCP_LI_HIST_IVAL_F_LENGTH; i++) {
                 entry = dccp_li_hist_entry_new(hist, SLAB_ATOMIC);
                 if (entry == NULL) {
                         dccp_li_hist_purge(hist, list);
-                        return NULL;
+                        dump_stack();
+                        return 0;
                 }
-                if (tail == NULL)
-                        tail = entry;
+                entry->dccplih_interval = ~0;
                 list_add(&entry->dccplih_node, list);
         }
 
         entry->dccplih_seqno     = seq_loss;
         entry->dccplih_win_count = win_loss;
-        return tail;
+        return 1;
 }
 
 EXPORT_SYMBOL_GPL(dccp_li_hist_interval_new);
diff --git a/net/dccp/ccids/lib/loss_interval.h b/net/dccp/ccids/lib/loss_interval.h
index 43bf78269d1d..0ae85f0340b2 100644
--- a/net/dccp/ccids/lib/loss_interval.h
+++ b/net/dccp/ccids/lib/loss_interval.h
@@ -4,7 +4,7 @@
  *  net/dccp/ccids/lib/loss_interval.h
  *
  *  Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
- *  Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
+ *  Copyright (c) 2005 Ian McDonald <ian.mcdonald@jandi.co.nz>
  *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  *
  *  This program is free software; you can redistribute it and/or modify it
@@ -52,9 +52,6 @@ extern void dccp_li_hist_purge(struct dccp_li_hist *hist,
 
 extern u32 dccp_li_hist_calc_i_mean(struct list_head *list);
 
-extern struct dccp_li_hist_entry *
-                        dccp_li_hist_interval_new(struct dccp_li_hist *hist,
-                                                  struct list_head *list,
-                                                  const u64 seq_loss,
-                                                  const u8 win_loss);
+extern int dccp_li_hist_interval_new(struct dccp_li_hist *hist,
+   struct list_head *list, const u64 seq_loss, const u8 win_loss);
 #endif /* _DCCP_LI_HIST_ */
diff --git a/net/dccp/ccids/lib/packet_history.c b/net/dccp/ccids/lib/packet_history.c
index ad98d6a322eb..b876c9c81c65 100644
--- a/net/dccp/ccids/lib/packet_history.c
+++ b/net/dccp/ccids/lib/packet_history.c
@@ -1,13 +1,13 @@
 /*
- *  net/dccp/packet_history.h
+ *  net/dccp/packet_history.c
  *
- *  Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
+ *  Copyright (c) 2005-6 The University of Waikato, Hamilton, New Zealand.
  *
  *  An implementation of the DCCP protocol
  *
  *  This code has been developed by the University of Waikato WAND
  *  research group. For further information please see http://www.wand.net.nz/
- *  or e-mail Ian McDonald - iam4@cs.waikato.ac.nz
+ *  or e-mail Ian McDonald - ian.mcdonald@jandi.co.nz
  *
  *  This code also uses code from Lulea University, rereleased as GPL by its
  *  authors:
@@ -112,64 +112,27 @@ struct dccp_rx_hist_entry *
 
 EXPORT_SYMBOL_GPL(dccp_rx_hist_find_data_packet);
 
-int dccp_rx_hist_add_packet(struct dccp_rx_hist *hist,
+void dccp_rx_hist_add_packet(struct dccp_rx_hist *hist,
                             struct list_head *rx_list,
                             struct list_head *li_list,
-                            struct dccp_rx_hist_entry *packet)
+                            struct dccp_rx_hist_entry *packet,
+                            u64 nonloss_seqno)
 {
-        struct dccp_rx_hist_entry *entry, *next, *iter;
+        struct dccp_rx_hist_entry *entry, *next;
         u8 num_later = 0;
 
-        iter = dccp_rx_hist_head(rx_list);
-        if (iter == NULL)
-                dccp_rx_hist_add_entry(rx_list, packet);
-        else {
-                const u64 seqno = packet->dccphrx_seqno;
-
-                if (after48(seqno, iter->dccphrx_seqno))
-                        dccp_rx_hist_add_entry(rx_list, packet);
-                else {
-                        if (dccp_rx_hist_entry_data_packet(iter))
-                                num_later = 1;
-
-                        list_for_each_entry_continue(iter, rx_list,
-                                                     dccphrx_node) {
-                                if (after48(seqno, iter->dccphrx_seqno)) {
-                                        dccp_rx_hist_add_entry(&iter->dccphrx_node,
-                                                               packet);
-                                        goto trim_history;
-                                }
-
-                                if (dccp_rx_hist_entry_data_packet(iter))
-                                        num_later++;
+        list_add(&packet->dccphrx_node, rx_list);
 
-                                if (num_later == TFRC_RECV_NUM_LATE_LOSS) {
-                                        dccp_rx_hist_entry_delete(hist, packet);
-                                        return 1;
-                                }
-                        }
-
-                        if (num_later < TFRC_RECV_NUM_LATE_LOSS)
-                                dccp_rx_hist_add_entry(rx_list, packet);
-                        /*
-                         * FIXME: else what? should we destroy the packet
-                         * like above?
-                         */
-                }
-        }
-
-trim_history:
-        /*
-         * Trim history (remove all packets after the NUM_LATE_LOSS + 1
-         * data packets)
-         */
         num_later = TFRC_RECV_NUM_LATE_LOSS + 1;
 
         if (!list_empty(li_list)) {
                 list_for_each_entry_safe(entry, next, rx_list, dccphrx_node) {
                         if (num_later == 0) {
-                                list_del_init(&entry->dccphrx_node);
-                                dccp_rx_hist_entry_delete(hist, entry);
+                                if (after48(nonloss_seqno,
+                                   entry->dccphrx_seqno)) {
+                                        list_del_init(&entry->dccphrx_node);
+                                        dccp_rx_hist_entry_delete(hist, entry);
+                                }
                         } else if (dccp_rx_hist_entry_data_packet(entry))
                                 --num_later;
                 }
@@ -217,94 +180,10 @@ trim_history:
                                 --num_later;
                 }
         }
-
-        return 0;
 }
 
 EXPORT_SYMBOL_GPL(dccp_rx_hist_add_packet);
 
-u64 dccp_rx_hist_detect_loss(struct list_head *rx_list,
-                             struct list_head *li_list, u8 *win_loss)
-{
-        struct dccp_rx_hist_entry *entry, *next, *packet;
-        struct dccp_rx_hist_entry *a_loss = NULL;
-        struct dccp_rx_hist_entry *b_loss = NULL;
-        u64 seq_loss = DCCP_MAX_SEQNO + 1;
-        u8 num_later = TFRC_RECV_NUM_LATE_LOSS;
-
-        list_for_each_entry_safe(entry, next, rx_list, dccphrx_node) {
-                if (num_later == 0) {
-                        b_loss = entry;
-                        break;
-                } else if (dccp_rx_hist_entry_data_packet(entry))
-                        --num_later;
-        }
-
-        if (b_loss == NULL)
-                goto out;
-
-        num_later = 1;
-        list_for_each_entry_safe_continue(entry, next, rx_list, dccphrx_node) {
-                if (num_later == 0) {
-                        a_loss = entry;
-                        break;
-                } else if (dccp_rx_hist_entry_data_packet(entry))
-                        --num_later;
-        }
-
-        if (a_loss == NULL) {
-                if (list_empty(li_list)) {
-                        /* no loss event have occured yet */
-                        LIMIT_NETDEBUG("%s: TODO: find a lost data packet by "
-                                       "comparing to initial seqno\n",
-                                       __FUNCTION__);
-                        goto out;
-                } else {
-                        LIMIT_NETDEBUG("%s: Less than 4 data pkts in history!",
-                                       __FUNCTION__);
-                        goto out;
-                }
-        }
-
-        /* Locate a lost data packet */
-        entry = packet = b_loss;
-        list_for_each_entry_safe_continue(entry, next, rx_list, dccphrx_node) {
-                u64 delta = dccp_delta_seqno(entry->dccphrx_seqno,
-                                             packet->dccphrx_seqno);
-
-                if (delta != 0) {
-                        if (dccp_rx_hist_entry_data_packet(packet))
-                                --delta;
-                        /*
-                         * FIXME: check this, probably this % usage is because
-                         * in earlier drafts the ndp count was just 8 bits
-                         * long, but now it cam be up to 24 bits long.
-                         */
-#if 0
-                        if (delta % DCCP_NDP_LIMIT !=
-                            (packet->dccphrx_ndp -
-                             entry->dccphrx_ndp) % DCCP_NDP_LIMIT)
-#endif
-                        if (delta != packet->dccphrx_ndp - entry->dccphrx_ndp) {
-                                seq_loss = entry->dccphrx_seqno;
-                                dccp_inc_seqno(&seq_loss);
-                        }
-                }
-                packet = entry;
-                if (packet == a_loss)
-                        break;
-        }
-out:
-        if (seq_loss != DCCP_MAX_SEQNO + 1)
-                *win_loss = a_loss->dccphrx_ccval;
-        else
-                *win_loss = 0; /* Paranoia */
-
-        return seq_loss;
-}
-
-EXPORT_SYMBOL_GPL(dccp_rx_hist_detect_loss);
-
 struct dccp_tx_hist *dccp_tx_hist_new(const char *name)
 {
         struct dccp_tx_hist *hist = kmalloc(sizeof(*hist), GFP_ATOMIC);
@@ -365,6 +244,25 @@ struct dccp_tx_hist_entry *
 
 EXPORT_SYMBOL_GPL(dccp_tx_hist_find_entry);
 
+int dccp_rx_hist_find_entry(const struct list_head *list, const u64 seq,
+   u8 *ccval)
+{
+        struct dccp_rx_hist_entry *packet = NULL, *entry;
+
+        list_for_each_entry(entry, list, dccphrx_node)
+                if (entry->dccphrx_seqno == seq) {
+                        packet = entry;
+                        break;
+                }
+
+        if (packet)
+                *ccval = packet->dccphrx_ccval;
+
+        return packet != NULL;
+}
+
+EXPORT_SYMBOL_GPL(dccp_rx_hist_find_entry);
+
 void dccp_tx_hist_purge_older(struct dccp_tx_hist *hist,
                               struct list_head *list,
                               struct dccp_tx_hist_entry *packet)
@@ -391,7 +289,7 @@ void dccp_tx_hist_purge(struct dccp_tx_hist *hist, struct list_head *list)
 
 EXPORT_SYMBOL_GPL(dccp_tx_hist_purge);
 
-MODULE_AUTHOR("Ian McDonald <iam4@cs.waikato.ac.nz>, "
+MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>, "
               "Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
 MODULE_DESCRIPTION("DCCP TFRC library");
 MODULE_LICENSE("GPL");
diff --git a/net/dccp/ccids/lib/packet_history.h b/net/dccp/ccids/lib/packet_history.h
index 673c209e4e85..067cf1c85a37 100644
--- a/net/dccp/ccids/lib/packet_history.h
+++ b/net/dccp/ccids/lib/packet_history.h
@@ -1,13 +1,13 @@
 /*
  *  net/dccp/packet_history.h
  *
- *  Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
+ *  Copyright (c) 2005-6 The University of Waikato, Hamilton, New Zealand.
  *
  *  An implementation of the DCCP protocol
  *
  *  This code has been developed by the University of Waikato WAND
  *  research group. For further information please see http://www.wand.net.nz/
- *  or e-mail Ian McDonald - iam4@cs.waikato.ac.nz
+ *  or e-mail Ian McDonald - ian.mcdonald@jandi.co.nz
  *
  *  This code also uses code from Lulea University, rereleased as GPL by its
  *  authors:
@@ -106,6 +106,8 @@ static inline void dccp_tx_hist_entry_delete(struct dccp_tx_hist *hist,
 extern struct dccp_tx_hist_entry *
                         dccp_tx_hist_find_entry(const struct list_head *list,
                                                 const u64 seq);
+extern int dccp_rx_hist_find_entry(const struct list_head *list, const u64 seq,
+   u8 *ccval);
 
 static inline void dccp_tx_hist_add_entry(struct list_head *list,
                                           struct dccp_tx_hist_entry *entry)
@@ -164,12 +166,6 @@ static inline void dccp_rx_hist_entry_delete(struct dccp_rx_hist *hist,
 extern void dccp_rx_hist_purge(struct dccp_rx_hist *hist,
                                struct list_head *list);
 
-static inline void dccp_rx_hist_add_entry(struct list_head *list,
-                                          struct dccp_rx_hist_entry *entry)
-{
-        list_add(&entry->dccphrx_node, list);
-}
-
 static inline struct dccp_rx_hist_entry *
                 dccp_rx_hist_head(struct list_head *list)
 {
@@ -188,10 +184,11 @@ static inline int
                entry->dccphrx_type == DCCP_PKT_DATAACK;
 }
 
-extern int dccp_rx_hist_add_packet(struct dccp_rx_hist *hist,
+extern void dccp_rx_hist_add_packet(struct dccp_rx_hist *hist,
                                    struct list_head *rx_list,
                                    struct list_head *li_list,
-                                   struct dccp_rx_hist_entry *packet);
+                                   struct dccp_rx_hist_entry *packet,
+                                   u64 nonloss_seqno);
 
 extern u64 dccp_rx_hist_detect_loss(struct list_head *rx_list,
                                     struct list_head *li_list, u8 *win_loss);
diff --git a/net/dccp/ccids/lib/tfrc.h b/net/dccp/ccids/lib/tfrc.h
index 130c4c40cfe3..45f30f59ea2a 100644
--- a/net/dccp/ccids/lib/tfrc.h
+++ b/net/dccp/ccids/lib/tfrc.h
@@ -4,7 +4,7 @@
  *  net/dccp/ccids/lib/tfrc.h
  *
  *  Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
- *  Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
+ *  Copyright (c) 2005 Ian McDonald <ian.mcdonald@jandi.co.nz>
  *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  *  Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
  *
diff --git a/net/dccp/ccids/lib/tfrc_equation.c b/net/dccp/ccids/lib/tfrc_equation.c
index 4fd2ebebf5a0..44076e0c6591 100644
--- a/net/dccp/ccids/lib/tfrc_equation.c
+++ b/net/dccp/ccids/lib/tfrc_equation.c
@@ -2,7 +2,7 @@
  *  net/dccp/ccids/lib/tfrc_equation.c
  *
  *  Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
- *  Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
+ *  Copyright (c) 2005 Ian McDonald <ian.mcdonald@jandi.co.nz>
  *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  *  Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
  *
diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index d00a2f4ee5dd..a5c5475724c0 100644
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -5,7 +5,7 @@
  *
  *  An implementation of the DCCP protocol
  *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
- *  Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
+ *  Copyright (c) 2005-6 Ian McDonald <ian.mcdonald@jandi.co.nz>
  *
  *      This program is free software; you can redistribute it and/or modify it
  *      under the terms of the GNU General Public License version 2 as
@@ -81,6 +81,14 @@ static inline u64 max48(const u64 seq1, const u64 seq2)
         return after48(seq1, seq2) ? seq1 : seq2;
 }
 
+/* is seq1 next seqno after seq2 */
+static inline int follows48(const u64 seq1, const u64 seq2)
+{
+        int diff = (seq1 & 0xFFFF) - (seq2 & 0xFFFF);
+
+        return diff==1;
+}
+
 enum {
         DCCP_MIB_NUM = 0,
         DCCP_MIB_ACTIVEOPENS,                   /* ActiveOpens */
diff --git a/net/dccp/options.c b/net/dccp/options.c
index daf72bb671f0..07a34696ac97 100644
--- a/net/dccp/options.c
+++ b/net/dccp/options.c
@@ -4,7 +4,7 @@
  *  An implementation of the DCCP protocol
  *  Copyright (c) 2005 Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
  *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
- *  Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
+ *  Copyright (c) 2005 Ian McDonald <ian.mcdonald@jandi.co.nz>
  *
  *      This program is free software; you can redistribute it and/or
  *      modify it under the terms of the GNU General Public License