-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);
-