Commit 78ad713d authored by Gerrit Renker's avatar Gerrit Renker Committed by David S. Miller
Browse files

[DCCP] ccid3: Track RX/TX packet size `s' using moving-average

Problem:
parent 2a1fda6f
......@@ -159,6 +159,25 @@ static void ccid3_hc_tx_update_x(struct sock *sk)
ccid3_update_send_time(hctx);
}
/*
* Track the mean packet size `s' (cf. RFC 4342, 5.3 and RFC 3448, 4.1)
* @len: DCCP packet payload size in bytes
*/
static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hctx, int len)
{
if (unlikely(len == 0))
ccid3_pr_debug("Packet payload length is 0 - not updating\n");
else
hctx->ccid3hctx_s = hctx->ccid3hctx_s == 0 ? len :
(9 * hctx->ccid3hctx_s + len) / 10;
/*
* Note: We could do a potential optimisation here - when `s' changes,
* recalculate sending rate and consequently t_ipi, t_delta, and
* t_now. This is however non-standard, and the benefits are not
* clear, so it is currently left out.
*/
}
static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
{
struct sock *sk = (struct sock *)data;
......@@ -299,6 +318,10 @@ static int ccid3_hc_tx_send_packet(struct sock *sk,
hctx->ccid3hctx_t_last_win_count = now;
ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);
/* Set initial sending rate to 1 packet per second */
ccid3_hc_tx_update_s(hctx, len);
hctx->ccid3hctx_x = hctx->ccid3hctx_s;
/* First timeout, according to [RFC 3448, 4.2], is 1 second */
hctx->ccid3hctx_t_ipi = USEC_PER_SEC;
/* Initial delta: minimum of 0.5 sec and t_gran/2 */
......@@ -350,6 +373,8 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, int len)
unsigned long quarter_rtt;
struct dccp_tx_hist_entry *packet;
ccid3_hc_tx_update_s(hctx, len);
packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist);
if (unlikely(packet == NULL)) {
DCCP_WARN("packet doesn't exist in history!\n");
......@@ -594,17 +619,9 @@ static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk)
{
struct dccp_sock *dp = dccp_sk(sk);
struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid);
if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE &&
dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE)
hctx->ccid3hctx_s = dp->dccps_packet_size;
else
hctx->ccid3hctx_s = TFRC_STD_PACKET_SIZE;
/* Set transmission rate to 1 packet per second */
hctx->ccid3hctx_x = hctx->ccid3hctx_s;
hctx->ccid3hctx_s = 0;
hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT;
INIT_LIST_HEAD(&hctx->ccid3hctx_hist);
......@@ -658,6 +675,15 @@ static void ccid3_hc_rx_set_state(struct sock *sk,
hcrx->ccid3hcrx_state = state;
}
static inline void ccid3_hc_rx_update_s(struct ccid3_hc_rx_sock *hcrx, int len)
{
if (unlikely(len == 0)) /* don't update on empty packets (e.g. ACKs) */
ccid3_pr_debug("Packet payload length is 0 - not updating\n");
else
hcrx->ccid3hcrx_s = hcrx->ccid3hcrx_s == 0 ? len :
(9 * hcrx->ccid3hcrx_s + len) / 10;
}
static void ccid3_hc_rx_send_feedback(struct sock *sk)
{
struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
......@@ -934,7 +960,7 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
struct dccp_rx_hist_entry *packet;
struct timeval now;
u32 p_prev, rtt_prev, r_sample, t_elapsed;
int loss;
int loss, payload_size;
BUG_ON(hcrx == NULL);
......@@ -989,6 +1015,9 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK)
return;
payload_size = skb->len - dccp_hdr(skb)->dccph_doff * 4;
ccid3_hc_rx_update_s(hcrx, payload_size);
switch (hcrx->ccid3hcrx_state) {
case TFRC_RSTATE_NO_DATA:
ccid3_pr_debug("%s, sk=%p(%s), skb=%p, sending initial "
......@@ -999,8 +1028,7 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA);
return;
case TFRC_RSTATE_DATA:
hcrx->ccid3hcrx_bytes_recv += skb->len -
dccp_hdr(skb)->dccph_doff * 4;
hcrx->ccid3hcrx_bytes_recv += payload_size;
if (loss)
break;
......@@ -1040,22 +1068,16 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk)
{
struct dccp_sock *dp = dccp_sk(sk);
struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid);
ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE &&
dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE)
hcrx->ccid3hcrx_s = dp->dccps_packet_size;
else
hcrx->ccid3hcrx_s = TFRC_STD_PACKET_SIZE;
hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA;
INIT_LIST_HEAD(&hcrx->ccid3hcrx_hist);
INIT_LIST_HEAD(&hcrx->ccid3hcrx_li_hist);
dccp_timestamp(sk, &hcrx->ccid3hcrx_tstamp_last_ack);
hcrx->ccid3hcrx_tstamp_last_feedback = hcrx->ccid3hcrx_tstamp_last_ack;
hcrx->ccid3hcrx_s = 0;
hcrx->ccid3hcrx_rtt = 5000; /* XXX 5ms for now... */
return 0;
}
......
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