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authorGerrit Renker <gerrit@erg.abdn.ac.uk>2008-09-04 07:30:19 +0200
committerGerrit Renker <gerrit@erg.abdn.ac.uk>2008-09-04 07:45:40 +0200
commit24b8d343215919c7a2ba18b9f89a0961e1459cad (patch)
tree2b97062dae6e80bb178a0cd0354aa71fe884ef30
parent8b67ad12b04ef7bdf5d2b4de24fe5a609b26cf12 (diff)
dccp tfrc: Receiver history initialisation routine
This patch 1) separates history allocation and initialisation, to facilitate early loss detection (implemented by a subsequent patch); 2) removes duplication by using the existing tfrc_rx_hist_purge() if the allocation fails. This is now possible, since the initialisation routine 3) zeroes out the entire history before using it. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
-rw-r--r--net/dccp/ccids/ccid3.c2
-rw-r--r--net/dccp/ccids/lib/packet_history.c52
-rw-r--r--net/dccp/ccids/lib/packet_history.h2
3 files changed, 32 insertions, 24 deletions
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index 5470a978be0..36f4992f3c3 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -766,7 +766,7 @@ static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk)
hcrx->state = TFRC_RSTATE_NO_DATA;
tfrc_lh_init(&hcrx->li_hist);
- return tfrc_rx_hist_alloc(&hcrx->hist);
+ return tfrc_rx_hist_init(&hcrx->hist, sk);
}
static void ccid3_hc_rx_exit(struct sock *sk)
diff --git a/net/dccp/ccids/lib/packet_history.c b/net/dccp/ccids/lib/packet_history.c
index 5c445086690..5b4e1cf8439 100644
--- a/net/dccp/ccids/lib/packet_history.c
+++ b/net/dccp/ccids/lib/packet_history.c
@@ -352,28 +352,6 @@ int tfrc_rx_handle_loss(struct tfrc_rx_hist *h,
}
EXPORT_SYMBOL_GPL(tfrc_rx_handle_loss);
-int tfrc_rx_hist_alloc(struct tfrc_rx_hist *h)
-{
- int i;
-
- for (i = 0; i <= TFRC_NDUPACK; i++) {
- h->ring[i] = kmem_cache_alloc(tfrc_rx_hist_slab, GFP_ATOMIC);
- if (h->ring[i] == NULL)
- goto out_free;
- }
-
- h->loss_count = h->loss_start = 0;
- return 0;
-
-out_free:
- while (i-- != 0) {
- kmem_cache_free(tfrc_rx_hist_slab, h->ring[i]);
- h->ring[i] = NULL;
- }
- return -ENOBUFS;
-}
-EXPORT_SYMBOL_GPL(tfrc_rx_hist_alloc);
-
void tfrc_rx_hist_purge(struct tfrc_rx_hist *h)
{
int i;
@@ -386,6 +364,36 @@ void tfrc_rx_hist_purge(struct tfrc_rx_hist *h)
}
EXPORT_SYMBOL_GPL(tfrc_rx_hist_purge);
+static int tfrc_rx_hist_alloc(struct tfrc_rx_hist *h)
+{
+ int i;
+
+ memset(h, 0, sizeof(*h));
+
+ for (i = 0; i <= TFRC_NDUPACK; i++) {
+ h->ring[i] = kmem_cache_alloc(tfrc_rx_hist_slab, GFP_ATOMIC);
+ if (h->ring[i] == NULL) {
+ tfrc_rx_hist_purge(h);
+ return -ENOBUFS;
+ }
+ }
+ return 0;
+}
+
+int tfrc_rx_hist_init(struct tfrc_rx_hist *h, struct sock *sk)
+{
+ if (tfrc_rx_hist_alloc(h))
+ return -ENOBUFS;
+ /*
+ * Initialise first entry with GSR to start loss detection as early as
+ * possible. Code using this must not use any other fields. The entry
+ * will be overwritten once the CCID updates its received packets.
+ */
+ tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno = dccp_sk(sk)->dccps_gsr;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(tfrc_rx_hist_init);
+
/**
* tfrc_rx_hist_rtt_last_s - reference entry to compute RTT samples against
*/
diff --git a/net/dccp/ccids/lib/packet_history.h b/net/dccp/ccids/lib/packet_history.h
index 221d8102da5..e9d8097947d 100644
--- a/net/dccp/ccids/lib/packet_history.h
+++ b/net/dccp/ccids/lib/packet_history.h
@@ -153,7 +153,7 @@ extern int tfrc_rx_handle_loss(struct tfrc_rx_hist *h,
struct sock *sk);
extern u32 tfrc_rx_hist_sample_rtt(struct tfrc_rx_hist *h,
const struct sk_buff *skb);
-extern int tfrc_rx_hist_alloc(struct tfrc_rx_hist *h);
+extern int tfrc_rx_hist_init(struct tfrc_rx_hist *h, struct sock *sk);
extern void tfrc_rx_hist_purge(struct tfrc_rx_hist *h);
#endif /* _DCCP_PKT_HIST_ */