[CCID3]: Move ccid3_hc_rx_add_hist to packet_history.c

Renaming it to dccp_rx_hist_add_packet.

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

2 files changed, 122 insertions, 0 deletions

diff --git a/net/dccp/ccids/lib/packet_history.c b/net/dccp/ccids/lib/packet_history.c
index f252a9555e31..e2576b45ac0b 100644
--- a/net/dccp/ccids/lib/packet_history.c
+++ b/net/dccp/ccids/lib/packet_history.c
@@ -113,6 +113,117 @@ 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,
+                            struct list_head *rx_list,
+                            struct list_head *li_list,
+                            struct dccp_rx_hist_entry *packet)
+{
+        struct dccp_rx_hist_entry *entry, *next, *iter;
+        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++;
+
+                                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);
+                        } else if (dccp_rx_hist_entry_data_packet(entry))
+                                --num_later;
+                }
+        } else {
+                int step = 0;
+                u8 win_count = 0; /* Not needed, but lets shut up gcc */
+                int tmp;
+                /*
+                 * We have no loss interval history so we need at least one
+                 * rtt:s of data packets to approximate rtt.
+                 */
+                list_for_each_entry_safe(entry, next, rx_list, dccphrx_node) {
+                        if (num_later == 0) {
+                                switch (step) {
+                                case 0:
+                                        step = 1;
+                                        /* OK, find next data packet */
+                                        num_later = 1;
+                                        break;
+                                case 1:
+                                        step = 2;
+                                        /* OK, find next data packet */
+                                        num_later = 1;
+                                        win_count = entry->dccphrx_ccval;
+                                        break;
+                                case 2:
+                                        tmp = win_count - entry->dccphrx_ccval;
+                                        if (tmp < 0)
+                                                tmp += TFRC_WIN_COUNT_LIMIT;
+                                        if (tmp > TFRC_WIN_COUNT_PER_RTT + 1) {
+                                                /*
+                                                 * We have found a packet older
+                                                 * than one rtt remove the rest
+                                                 */
+                                                step = 3;
+                                        } else /* OK, find next data packet */
+                                                num_later = 1;
+                                        break;
+                                case 3:
+                                        list_del_init(&entry->dccphrx_node);
+                                        dccp_rx_hist_entry_delete(hist, entry);
+                                        break;
+                                }
+                        } else if (dccp_rx_hist_entry_data_packet(entry))
+                                --num_later;
+                }
+        }
+
+        return 0;
+}
+
+EXPORT_SYMBOL_GPL(dccp_rx_hist_add_packet);
+
 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 235828d822d9..ebfcb8e2c676 100644
--- a/net/dccp/ccids/lib/packet_history.h
+++ b/net/dccp/ccids/lib/packet_history.h
@@ -44,6 +44,12 @@
 
 #include "../../dccp.h"
 
+/* Number of later packets received before one is considered lost */
+#define TFRC_RECV_NUM_LATE_LOSS  3
+
+#define TFRC_WIN_COUNT_PER_RTT   4
+#define TFRC_WIN_COUNT_LIMIT    16
+
 struct dccp_tx_hist_entry {
         struct list_head dccphtx_node;
         u64              dccphtx_seqno:48,
@@ -182,4 +188,9 @@ static inline int
                entry->dccphrx_type == DCCP_PKT_DATAACK;
 }
 
+extern int 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);
+
 #endif /* _DCCP_PKT_HIST_ */