diff options
Diffstat (limited to 'net/dccp/ccids/lib/packet_history.c')
-rw-r--r-- | net/dccp/ccids/lib/packet_history.c | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/net/dccp/ccids/lib/packet_history.c b/net/dccp/ccids/lib/packet_history.c index e2576b45ac0..d3f9d205383 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); |