[TFRC_SSTATE_NO_SENT] = "NO_SENT",
[TFRC_SSTATE_NO_FBACK] = "NO_FBACK",
[TFRC_SSTATE_FBACK] = "FBACK",
- [TFRC_SSTATE_TERM] = "TERM",
};
return ccid3_state_names[state];
return scaled_div(w_init << 6, hc->tx_rtt);
}
-/*
- * Recalculate t_ipi and delta (should be called whenever X changes)
+/**
+ * ccid3_update_send_interval - Calculate new t_ipi = s / X_inst
+ * This respects the granularity of X_inst (64 * bytes/second).
*/
static void ccid3_update_send_interval(struct ccid3_hc_tx_sock *hc)
{
- /* Calculate new t_ipi = s / X_inst (X_inst is in 64 * bytes/second) */
hc->tx_t_ipi = scaled_div32(((u64)hc->tx_s) << 6, hc->tx_x);
- /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */
- hc->tx_delta = min_t(u32, hc->tx_t_ipi / 2, TFRC_OPSYS_HALF_TIME_GRAN);
-
- ccid3_pr_debug("t_ipi=%u, delta=%u, s=%u, X=%u\n", hc->tx_t_ipi,
- hc->tx_delta, hc->tx_s, (unsigned)(hc->tx_x >> 6));
+ ccid3_pr_debug("t_ipi=%u, s=%u, X=%u\n", hc->tx_t_ipi,
+ hc->tx_s, (unsigned)(hc->tx_x >> 6));
}
static u32 ccid3_hc_tx_idle_rtt(struct ccid3_hc_tx_sock *hc, ktime_t now)
ccid3_pr_debug("%s(%p, state=%s) - entry\n", dccp_role(sk), sk,
ccid3_tx_state_name(hc->tx_state));
+ /* Ignore and do not restart after leaving the established state */
+ if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
+ goto out;
+
+ /* Reset feedback state to "no feedback received" */
if (hc->tx_state == TFRC_SSTATE_FBACK)
ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);
- else if (hc->tx_state != TFRC_SSTATE_NO_FBACK)
- goto out;
/*
* Determine new allowed sending rate X as per draft rfc3448bis-00, 4.4
+ * RTO is 0 if and only if no feedback has been received yet.
*/
- if (hc->tx_t_rto == 0 || /* no feedback received yet */
- hc->tx_p == 0) {
+ if (hc->tx_t_rto == 0 || hc->tx_p == 0) {
/* halve send rate directly */
hc->tx_x = max(hc->tx_x / 2,
* Set new timeout for the nofeedback timer.
* See comments in packet_recv() regarding the value of t_RTO.
*/
- if (unlikely(hc->tx_t_rto == 0)) /* no feedback yet */
+ if (unlikely(hc->tx_t_rto == 0)) /* no feedback received yet */
t_nfb = TFRC_INITIAL_TIMEOUT;
else
t_nfb = max(hc->tx_t_rto, 2 * hc->tx_t_ipi);
sock_put(sk);
}
-/*
- * returns
- * > 0: delay (in msecs) that should pass before actually sending
- * = 0: can send immediately
- * < 0: error condition; do not send packet
+/**
+ * ccid3_hc_tx_send_packet - Delay-based dequeueing of TX packets
+ * @skb: next packet candidate to send on @sk
+ * This function uses the convention of ccid_packet_dequeue_eval() and
+ * returns a millisecond-delay value between 0 and t_mbi = 64000 msec.
*/
static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
{
if (unlikely(skb->len == 0))
return -EBADMSG;
- switch (hc->tx_state) {
- case TFRC_SSTATE_NO_SENT:
+ if (hc->tx_state == TFRC_SSTATE_NO_SENT) {
sk_reset_timer(sk, &hc->tx_no_feedback_timer, (jiffies +
usecs_to_jiffies(TFRC_INITIAL_TIMEOUT)));
hc->tx_last_win_count = 0;
ccid3_update_send_interval(hc);
ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);
- break;
- case TFRC_SSTATE_NO_FBACK:
- case TFRC_SSTATE_FBACK:
+
+ } else {
delay = ktime_us_delta(hc->tx_t_nom, now);
ccid3_pr_debug("delay=%ld\n", (long)delay);
/*
- * Scheduling of packet transmissions [RFC 3448, 4.6]
+ * Scheduling of packet transmissions (RFC 5348, 8.3)
*
* if (t_now > t_nom - delta)
* // send the packet now
* else
* // send the packet in (t_nom - t_now) milliseconds.
*/
- if (delay - (s64)hc->tx_delta >= 1000)
- return (u32)delay / 1000L;
+ if (delay >= TFRC_T_DELTA)
+ return (u32)delay / USEC_PER_MSEC;
ccid3_hc_tx_update_win_count(hc, now);
- break;
- case TFRC_SSTATE_TERM:
- DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk);
- return -EINVAL;
}
/* prepare to send now (add options etc.) */
/* set the nominal send time for the next following packet */
hc->tx_t_nom = ktime_add_us(hc->tx_t_nom, hc->tx_t_ipi);
- return 0;
+ return CCID_PACKET_SEND_AT_ONCE;
}
-static void ccid3_hc_tx_packet_sent(struct sock *sk, int more,
- unsigned int len)
+static void ccid3_hc_tx_packet_sent(struct sock *sk, unsigned int len)
{
struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk);
static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
{
struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk);
- struct ccid3_options_received *opt_recv;
+ struct tfrc_tx_hist_entry *acked;
ktime_t now;
unsigned long t_nfb;
- u32 pinv, r_sample;
+ u32 r_sample;
/* we are only interested in ACKs */
if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK ||
DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK))
return;
- /* ... and only in the established state */
- if (hc->tx_state != TFRC_SSTATE_FBACK &&
- hc->tx_state != TFRC_SSTATE_NO_FBACK)
- return;
-
- opt_recv = &hc->tx_options_received;
- now = ktime_get_real();
-
- /* Estimate RTT from history if ACK number is valid */
- r_sample = tfrc_tx_hist_rtt(hc->tx_hist,
- DCCP_SKB_CB(skb)->dccpd_ack_seq, now);
- if (r_sample == 0) {
- DCCP_WARN("%s(%p): %s with bogus ACK-%llu\n", dccp_role(sk), sk,
- dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type),
- (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq);
- return;
- }
-
- /* Update receive rate in units of 64 * bytes/second */
- hc->tx_x_recv = opt_recv->ccid3or_receive_rate;
- hc->tx_x_recv <<= 6;
-
- /* Update loss event rate (which is scaled by 1e6) */
- pinv = opt_recv->ccid3or_loss_event_rate;
- if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */
- hc->tx_p = 0;
- else /* can not exceed 100% */
- hc->tx_p = scaled_div(1, pinv);
/*
- * Validate new RTT sample and update moving average
+ * Locate the acknowledged packet in the TX history.
+ *
+ * Returning "entry not found" here can for instance happen when
+ * - the host has not sent out anything (e.g. a passive server),
+ * - the Ack is outdated (packet with higher Ack number was received),
+ * - it is a bogus Ack (for a packet not sent on this connection).
*/
- r_sample = dccp_sample_rtt(sk, r_sample);
+ acked = tfrc_tx_hist_find_entry(hc->tx_hist, dccp_hdr_ack_seq(skb));
+ if (acked == NULL)
+ return;
+ /* For the sake of RTT sampling, ignore/remove all older entries */
+ tfrc_tx_hist_purge(&acked->next);
+
+ /* Update the moving average for the RTT estimate (RFC 3448, 4.3) */
+ now = ktime_get_real();
+ r_sample = dccp_sample_rtt(sk, ktime_us_delta(now, acked->stamp));
hc->tx_rtt = tfrc_ewma(hc->tx_rtt, r_sample, 9);
+
/*
* Update allowed sending rate X as per draft rfc3448bis-00, 4.2/3
*/
sk->sk_write_space(sk);
/*
- * Update timeout interval for the nofeedback timer.
- * We use a configuration option to increase the lower bound.
- * This can help avoid triggering the nofeedback timer too
- * often ('spinning') on LANs with small RTTs.
+ * Update timeout interval for the nofeedback timer. In order to control
+ * rate halving on networks with very low RTTs (<= 1 ms), use per-route
+ * tunable RTAX_RTO_MIN value as the lower bound.
*/
- hc->tx_t_rto = max_t(u32, 4 * hc->tx_rtt, (CONFIG_IP_DCCP_CCID3_RTO *
- (USEC_PER_SEC / 1000)));
+ hc->tx_t_rto = max_t(u32, 4 * hc->tx_rtt,
+ USEC_PER_SEC/HZ * tcp_rto_min(sk));
/*
* Schedule no feedback timer to expire in
* max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi)
jiffies + usecs_to_jiffies(t_nfb));
}
-static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
- unsigned char len, u16 idx,
- unsigned char *value)
+static int ccid3_hc_tx_parse_options(struct sock *sk, u8 packet_type,
+ u8 option, u8 *optval, u8 optlen)
{
- int rc = 0;
- const struct dccp_sock *dp = dccp_sk(sk);
struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk);
- struct ccid3_options_received *opt_recv;
__be32 opt_val;
- opt_recv = &hc->tx_options_received;
-
- if (opt_recv->ccid3or_seqno != dp->dccps_gsr) {
- opt_recv->ccid3or_seqno = dp->dccps_gsr;
- opt_recv->ccid3or_loss_event_rate = ~0;
- opt_recv->ccid3or_loss_intervals_idx = 0;
- opt_recv->ccid3or_loss_intervals_len = 0;
- opt_recv->ccid3or_receive_rate = 0;
- }
-
switch (option) {
+ case TFRC_OPT_RECEIVE_RATE:
case TFRC_OPT_LOSS_EVENT_RATE:
- if (unlikely(len != 4)) {
- DCCP_WARN("%s(%p), invalid len %d "
- "for TFRC_OPT_LOSS_EVENT_RATE\n",
- dccp_role(sk), sk, len);
- rc = -EINVAL;
- } else {
- opt_val = get_unaligned((__be32 *)value);
- opt_recv->ccid3or_loss_event_rate = ntohl(opt_val);
- ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n",
- dccp_role(sk), sk,
- opt_recv->ccid3or_loss_event_rate);
+ /* Must be ignored on Data packets, cf. RFC 4342 8.3 and 8.5 */
+ if (packet_type == DCCP_PKT_DATA)
+ break;
+ if (unlikely(optlen != 4)) {
+ DCCP_WARN("%s(%p), invalid len %d for %u\n",
+ dccp_role(sk), sk, optlen, option);
+ return -EINVAL;
}
- break;
- case TFRC_OPT_LOSS_INTERVALS:
- opt_recv->ccid3or_loss_intervals_idx = idx;
- opt_recv->ccid3or_loss_intervals_len = len;
- ccid3_pr_debug("%s(%p), LOSS_INTERVALS=(%u, %u)\n",
- dccp_role(sk), sk,
- opt_recv->ccid3or_loss_intervals_idx,
- opt_recv->ccid3or_loss_intervals_len);
- break;
- case TFRC_OPT_RECEIVE_RATE:
- if (unlikely(len != 4)) {
- DCCP_WARN("%s(%p), invalid len %d "
- "for TFRC_OPT_RECEIVE_RATE\n",
- dccp_role(sk), sk, len);
- rc = -EINVAL;
- } else {
- opt_val = get_unaligned((__be32 *)value);
- opt_recv->ccid3or_receive_rate = ntohl(opt_val);
+ opt_val = ntohl(get_unaligned((__be32 *)optval));
+
+ if (option == TFRC_OPT_RECEIVE_RATE) {
+ /* Receive Rate is kept in units of 64 bytes/second */
+ hc->tx_x_recv = opt_val;
+ hc->tx_x_recv <<= 6;
+
ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n",
- dccp_role(sk), sk,
- opt_recv->ccid3or_receive_rate);
+ dccp_role(sk), sk, opt_val);
+ } else {
+ /* Update the fixpoint Loss Event Rate fraction */
+ hc->tx_p = tfrc_invert_loss_event_rate(opt_val);
+
+ ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n",
+ dccp_role(sk), sk, opt_val);
}
- break;
}
-
- return rc;
+ return 0;
}
static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk)
{
struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk);
- ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM);
sk_stop_timer(sk, &hc->tx_no_feedback_timer);
-
tfrc_tx_hist_purge(&hc->tx_hist);
}
static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info)
{
- struct ccid3_hc_tx_sock *hc;
-
- /* Listen socks doesn't have a private CCID block */
- if (sk->sk_state == DCCP_LISTEN)
- return;
-
- hc = ccid3_hc_tx_sk(sk);
- info->tcpi_rto = hc->tx_t_rto;
- info->tcpi_rtt = hc->tx_rtt;
+ info->tcpi_rto = ccid3_hc_tx_sk(sk)->tx_t_rto;
+ info->tcpi_rtt = ccid3_hc_tx_sk(sk)->tx_rtt;
}
static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len,
u32 __user *optval, int __user *optlen)
{
- const struct ccid3_hc_tx_sock *hc;
+ const struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk);
+ struct tfrc_tx_info tfrc;
const void *val;
- /* Listen socks doesn't have a private CCID block */
- if (sk->sk_state == DCCP_LISTEN)
- return -EINVAL;
-
- hc = ccid3_hc_tx_sk(sk);
switch (optname) {
case DCCP_SOCKOPT_CCID_TX_INFO:
- if (len < sizeof(hc->tx_tfrc))
+ if (len < sizeof(tfrc))
return -EINVAL;
- len = sizeof(hc->tx_tfrc);
- val = &hc->tx_tfrc;
+ tfrc.tfrctx_x = hc->tx_x;
+ tfrc.tfrctx_x_recv = hc->tx_x_recv;
+ tfrc.tfrctx_x_calc = hc->tx_x_calc;
+ tfrc.tfrctx_rtt = hc->tx_rtt;
+ tfrc.tfrctx_p = hc->tx_p;
+ tfrc.tfrctx_rto = hc->tx_t_rto;
+ tfrc.tfrctx_ipi = hc->tx_t_ipi;
+ len = sizeof(tfrc);
+ val = &tfrc;
break;
default:
return -ENOPROTOOPT;
static const char *const ccid3_rx_state_names[] = {
[TFRC_RSTATE_NO_DATA] = "NO_DATA",
[TFRC_RSTATE_DATA] = "DATA",
- [TFRC_RSTATE_TERM] = "TERM",
};
return ccid3_rx_state_names[state];
{
struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk);
struct dccp_sock *dp = dccp_sk(sk);
- ktime_t now;
+ ktime_t now = ktime_get_real();
s64 delta = 0;
- if (unlikely(hc->rx_state == TFRC_RSTATE_TERM))
- return;
-
- now = ktime_get_real();
-
switch (fbtype) {
case CCID3_FBACK_INITIAL:
hc->rx_x_recv = 0;
static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb)
{
- const struct ccid3_hc_rx_sock *hc;
+ const struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk);
__be32 x_recv, pinv;
if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN))
return 0;
- hc = ccid3_hc_rx_sk(sk);
-
if (dccp_packet_without_ack(skb))
return 0;
x_recv = scaled_div32(hc->rx_bytes_recv, delta);
if (x_recv == 0) { /* would also trigger divide-by-zero */
DCCP_WARN("X_recv==0\n");
- if ((x_recv = hc->rx_x_recv) == 0) {
+ if (hc->rx_x_recv == 0) {
DCCP_BUG("stored value of X_recv is zero");
return ~0U;
}
+ x_recv = hc->rx_x_recv;
}
fval = scaled_div(hc->rx_s, hc->rx_rtt);
{
struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk);
- ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM);
-
tfrc_rx_hist_purge(&hc->rx_hist);
tfrc_lh_cleanup(&hc->rx_li_hist);
}
static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info)
{
- const struct ccid3_hc_rx_sock *hc;
-
- /* Listen socks doesn't have a private CCID block */
- if (sk->sk_state == DCCP_LISTEN)
- return;
-
- hc = ccid3_hc_rx_sk(sk);
- info->tcpi_ca_state = hc->rx_state;
+ info->tcpi_ca_state = ccid3_hc_rx_sk(sk)->rx_state;
info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
- info->tcpi_rcv_rtt = hc->rx_rtt;
+ info->tcpi_rcv_rtt = ccid3_hc_rx_sk(sk)->rx_rtt;
}
static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len,
u32 __user *optval, int __user *optlen)
{
- const struct ccid3_hc_rx_sock *hc;
+ const struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk);
struct tfrc_rx_info rx_info;
const void *val;
- /* Listen socks doesn't have a private CCID block */
- if (sk->sk_state == DCCP_LISTEN)
- return -EINVAL;
-
- hc = ccid3_hc_rx_sk(sk);
switch (optname) {
case DCCP_SOCKOPT_CCID_RX_INFO:
if (len < sizeof(rx_info))
return -EINVAL;
rx_info.tfrcrx_x_recv = hc->rx_x_recv;
rx_info.tfrcrx_rtt = hc->rx_rtt;
- rx_info.tfrcrx_p = hc->rx_pinv == 0 ? ~0U :
- scaled_div(1, hc->rx_pinv);
+ rx_info.tfrcrx_p = tfrc_invert_loss_event_rate(hc->rx_pinv);
len = sizeof(rx_info);
val = &rx_info;
break;
git://bbs.cooldavid.org / net-next-2.6.git / blobdiff