aboutsummaryrefslogtreecommitdiff
path: root/net/dccp/ccids/lib/loss_interval.h
diff options
context:
space:
mode:
authorGerrit Renker <gerrit@erg.abdn.ac.uk>2007-12-12 13:50:51 -0200
committerDavid S. Miller <davem@davemloft.net>2008-01-28 14:57:18 -0800
commit8a9c7e92e0ca97632126feee32ba2698b4eb6c8f (patch)
treeb569d6e39f3630f7a973814a925502035c63904b /net/dccp/ccids/lib/loss_interval.h
parent8995a238ef6869bc5c80240440bc58452c7af283 (diff)
[TFRC]: Ringbuffer to track loss interval history
A ringbuffer-based implementation of loss interval history is easier to maintain, allocate, and update. The `swap' routine to keep the RX history sorted is due to and was written by Arnaldo Carvalho de Melo, simplifying an earlier macro-based variant. Details: * access to the Loss Interval Records via macro wrappers (with safety checks); * simplified, on-demand allocation of entries (no extra memory consumption on lossless links); cache allocation is local to the module / exported as service; * provision of RFC-compliant algorithm to re-compute average loss interval; * provision of comprehensive, new loss detection algorithm - support for all cases of loss, including re-ordered/duplicate packets; - waiting for NDUPACK=3 packets to fill the hole; - updating loss records when a late-arriving packet fills a hole. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dccp/ccids/lib/loss_interval.h')
-rw-r--r--net/dccp/ccids/lib/loss_interval.h56
1 files changed, 55 insertions, 1 deletions
diff --git a/net/dccp/ccids/lib/loss_interval.h b/net/dccp/ccids/lib/loss_interval.h
index 27bee92dae1..5e3c5c54a49 100644
--- a/net/dccp/ccids/lib/loss_interval.h
+++ b/net/dccp/ccids/lib/loss_interval.h
@@ -3,6 +3,7 @@
/*
* net/dccp/ccids/lib/loss_interval.h
*
+ * Copyright (c) 2007 The University of Aberdeen, Scotland, UK
* Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand.
* Copyright (c) 2005-7 Ian McDonald <ian.mcdonald@jandi.co.nz>
* Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
@@ -12,11 +13,64 @@
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*/
-
#include <linux/ktime.h>
#include <linux/list.h>
+#include <linux/slab.h>
+
+/*
+ * Number of loss intervals (RFC 4342, 8.6.1). The history size is one more than
+ * NINTERVAL, since the `open' interval I_0 is always stored as the first entry.
+ */
+#define NINTERVAL 8
+#define LIH_SIZE (NINTERVAL + 1)
+
+/**
+ * tfrc_loss_interval - Loss history record for TFRC-based protocols
+ * @li_seqno: Highest received seqno before the start of loss
+ * @li_ccval: The CCVal belonging to @li_seqno
+ * @li_is_closed: Whether @li_seqno is older than 1 RTT
+ * @li_length: Loss interval sequence length
+ */
+struct tfrc_loss_interval {
+ u64 li_seqno:48,
+ li_ccval:4,
+ li_is_closed:1;
+ u32 li_length;
+};
+
+/**
+ * tfrc_loss_hist - Loss record database
+ * @ring: Circular queue managed in LIFO manner
+ * @counter: Current count of entries (can be more than %LIH_SIZE)
+ * @i_mean: Current Average Loss Interval [RFC 3448, 5.4]
+ */
+struct tfrc_loss_hist {
+ struct tfrc_loss_interval *ring[LIH_SIZE];
+ u8 counter;
+ u32 i_mean;
+};
+
+static inline void tfrc_lh_init(struct tfrc_loss_hist *lh)
+{
+ memset(lh, 0, sizeof(struct tfrc_loss_hist));
+}
+
+static inline u8 tfrc_lh_is_initialised(struct tfrc_loss_hist *lh)
+{
+ return lh->counter > 0;
+}
+
+static inline u8 tfrc_lh_length(struct tfrc_loss_hist *lh)
+{
+ return min(lh->counter, (u8)LIH_SIZE);
+}
extern void dccp_li_hist_purge(struct list_head *list);
+struct tfrc_rx_hist;
+extern int tfrc_lh_interval_add(struct tfrc_loss_hist *, struct tfrc_rx_hist *,
+ u32 (*first_li)(struct sock *), struct sock *);
+extern u8 tfrc_lh_update_i_mean(struct tfrc_loss_hist *lh, struct sk_buff *);
+extern void tfrc_lh_cleanup(struct tfrc_loss_hist *lh);
extern u32 dccp_li_hist_calc_i_mean(struct list_head *list);