From 24b8d343215919c7a2ba18b9f89a0961e1459cad Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Thu, 4 Sep 2008 07:30:19 +0200 Subject: 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 --- net/dccp/ccids/ccid3.c | 2 +- net/dccp/ccids/lib/packet_history.c | 52 +++++++++++++++++++++---------------- net/dccp/ccids/lib/packet_history.h | 2 +- 3 files changed, 32 insertions(+), 24 deletions(-) (limited to 'net/dccp') 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_ */ -- cgit v1.2.3