[CCID3]: Move ccid3_hc_rx_detect_loss to packet_history.c

Renaming it to dccp_rx_hist_detect_loss.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 85 insertions, 0 deletions

diff --git a/net/dccp/ccids/lib/packet_history.c b/net/dccp/ccids/lib/packet_history.c
index e2576b45ac0b..d3f9d2053830 100644
--- a/net/dccp/ccids/lib/packet_history.c
+++ b/net/dccp/ccids/lib/packet_history.c
@@ -224,6 +224,88 @@ trim_history:
 
 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);
diff --git a/net/dccp/ccids/lib/packet_history.h b/net/dccp/ccids/lib/packet_history.h
index ebfcb8e2c676..fb90a91aa93d 100644
--- a/net/dccp/ccids/lib/packet_history.h
+++ b/net/dccp/ccids/lib/packet_history.h
@@ -193,4 +193,7 @@ extern int dccp_rx_hist_add_packet(struct dccp_rx_hist *hist,
                                    struct list_head *li_list,
                                    struct dccp_rx_hist_entry *packet);
 
+extern u64 dccp_rx_hist_detect_loss(struct list_head *rx_list,
+                                    struct list_head *li_list, u8 *win_loss);
+
 #endif /* _DCCP_PKT_HIST_ */