* net/dccp/ccids/ccid3.c
*
* Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
- * Copyright (c) 2005-6 Ian McDonald <imcdnzl@gmail.com>
+ * Copyright (c) 2005-6 Ian McDonald <ian.mcdonald@jandi.co.nz>
*
* An implementation of the DCCP protocol
*
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
-#include <linux/config.h>
#include "../ccid.h"
#include "../dccp.h"
#include "lib/packet_history.h"
#include "lib/tfrc.h"
#include "ccid3.h"
-/*
- * Reason for maths here is to avoid 32 bit overflow when a is big.
- * With this we get close to the limit.
- */
-static inline u32 usecs_div(const u32 a, const u32 b)
-{
- const u32 div = a < (UINT_MAX / (USEC_PER_SEC / 10)) ? 10 :
- a < (UINT_MAX / (USEC_PER_SEC / 50)) ? 50 :
- a < (UINT_MAX / (USEC_PER_SEC / 100)) ? 100 :
- a < (UINT_MAX / (USEC_PER_SEC / 500)) ? 500 :
- a < (UINT_MAX / (USEC_PER_SEC / 1000)) ? 1000 :
- a < (UINT_MAX / (USEC_PER_SEC / 5000)) ? 5000 :
- a < (UINT_MAX / (USEC_PER_SEC / 10000)) ? 10000 :
- a < (UINT_MAX / (USEC_PER_SEC / 50000)) ? 50000 :
- 100000;
- const u32 tmp = a * (USEC_PER_SEC / div);
- return (b >= 2 * div) ? tmp / (b / div) : tmp;
-}
-
+#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
static int ccid3_debug;
-
-#ifdef CCID3_DEBUG
-#define ccid3_pr_debug(format, a...) \
- do { if (ccid3_debug) \
- printk(KERN_DEBUG "%s: " format, __FUNCTION__, ##a); \
- } while (0)
+#define ccid3_pr_debug(format, a...) DCCP_PR_DEBUG(ccid3_debug, format, ##a)
#else
#define ccid3_pr_debug(format, a...)
#endif
static struct dccp_rx_hist *ccid3_rx_hist;
static struct dccp_li_hist *ccid3_li_hist;
-static int ccid3_init(struct sock *sk)
-{
- return 0;
-}
-
-static void ccid3_exit(struct sock *sk)
-{
-}
-
-/* TFRC sender states */
-enum ccid3_hc_tx_states {
- TFRC_SSTATE_NO_SENT = 1,
- TFRC_SSTATE_NO_FBACK,
- TFRC_SSTATE_FBACK,
- TFRC_SSTATE_TERM,
-};
-
-#ifdef CCID3_DEBUG
+#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state)
{
static char *ccid3_state_names[] = {
}
#endif
-static inline void ccid3_hc_tx_set_state(struct sock *sk,
- enum ccid3_hc_tx_states state)
+static void ccid3_hc_tx_set_state(struct sock *sk,
+ enum ccid3_hc_tx_states state)
{
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
enum ccid3_hc_tx_states oldstate = hctx->ccid3hctx_state;
hctx->ccid3hctx_state = state;
}
-/* Calculate new t_ipi (inter packet interval) by t_ipi = s / X_inst */
-static inline void ccid3_calc_new_t_ipi(struct ccid3_hc_tx_sock *hctx)
+/*
+ * Recalculate scheduled nominal send time t_nom, inter-packet interval
+ * t_ipi, and delta value. Should be called after each change to X.
+ */
+static inline void ccid3_update_send_time(struct ccid3_hc_tx_sock *hctx)
{
- /*
- * If no feedback spec says t_ipi is 1 second (set elsewhere and then
- * doubles after every no feedback timer (separate function)
- */
- if (hctx->ccid3hctx_state != TFRC_SSTATE_NO_FBACK)
- hctx->ccid3hctx_t_ipi = usecs_div(hctx->ccid3hctx_s,
- hctx->ccid3hctx_x);
-}
+ timeval_sub_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi);
-/* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */
-static inline void ccid3_calc_new_delta(struct ccid3_hc_tx_sock *hctx)
-{
+ /* Calculate new t_ipi = s / X_inst (X_inst is in 64 * bytes/second) */
+ hctx->ccid3hctx_t_ipi = scaled_div(hctx->ccid3hctx_s,
+ hctx->ccid3hctx_x >> 6);
+
+ /* Update nominal send time with regard to the new t_ipi */
+ timeval_add_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi);
+
+ /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */
hctx->ccid3hctx_delta = min_t(u32, hctx->ccid3hctx_t_ipi / 2,
TFRC_OPSYS_HALF_TIME_GRAN);
}
-
/*
* Update X by
* If (p > 0)
- * x_calc = calcX(s, R, p);
+ * X_calc = calcX(s, R, p);
* X = max(min(X_calc, 2 * X_recv), s / t_mbi);
* Else
* If (now - tld >= R)
* X = max(min(2 * X, 2 * X_recv), s / R);
* tld = now;
- */
-static void ccid3_hc_tx_update_x(struct sock *sk)
+ *
+ * Note: X and X_recv are both stored in units of 64 * bytes/second, to support
+ * fine-grained resolution of sending rates. This requires scaling by 2^6
+ * throughout the code. Only X_calc is unscaled (in bytes/second).
+ *
+ * If X has changed, we also update the scheduled send time t_now,
+ * the inter-packet interval t_ipi, and the delta value.
+ */
+static void ccid3_hc_tx_update_x(struct sock *sk, struct timeval *now)
+
{
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
+ const __u64 old_x = hctx->ccid3hctx_x;
- /* To avoid large error in calcX */
- if (hctx->ccid3hctx_p >= TFRC_SMALLEST_P) {
- hctx->ccid3hctx_x_calc = tfrc_calc_x(hctx->ccid3hctx_s,
- hctx->ccid3hctx_rtt,
- hctx->ccid3hctx_p);
- hctx->ccid3hctx_x = max_t(u32, min_t(u32, hctx->ccid3hctx_x_calc,
- 2 * hctx->ccid3hctx_x_recv),
- (hctx->ccid3hctx_s /
- TFRC_MAX_BACK_OFF_TIME));
- } else {
- struct timeval now;
+ if (hctx->ccid3hctx_p > 0) {
- dccp_timestamp(sk, &now);
- if (timeval_delta(&now, &hctx->ccid3hctx_t_ld) >=
- hctx->ccid3hctx_rtt) {
- hctx->ccid3hctx_x = max_t(u32, min_t(u32, hctx->ccid3hctx_x_recv,
- hctx->ccid3hctx_x) * 2,
- usecs_div(hctx->ccid3hctx_s,
- hctx->ccid3hctx_rtt));
- hctx->ccid3hctx_t_ld = now;
- }
+ hctx->ccid3hctx_x = min(((__u64)hctx->ccid3hctx_x_calc) << 6,
+ hctx->ccid3hctx_x_recv * 2);
+ hctx->ccid3hctx_x = max(hctx->ccid3hctx_x,
+ (((__u64)hctx->ccid3hctx_s) << 6) /
+ TFRC_T_MBI);
+
+ } else if (timeval_delta(now, &hctx->ccid3hctx_t_ld) -
+ (suseconds_t)hctx->ccid3hctx_rtt >= 0) {
+
+ hctx->ccid3hctx_x =
+ max(2 * min(hctx->ccid3hctx_x, hctx->ccid3hctx_x_recv),
+ scaled_div(((__u64)hctx->ccid3hctx_s) << 6,
+ hctx->ccid3hctx_rtt));
+ hctx->ccid3hctx_t_ld = *now;
+ }
+
+ if (hctx->ccid3hctx_x != old_x)
+ 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.
+ */
+}
+
+/*
+ * Update Window Counter using the algorithm from [RFC 4342, 8.1].
+ * The algorithm is not applicable if RTT < 4 microseconds.
+ */
+static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hctx,
+ struct timeval *now)
+{
+ suseconds_t delta;
+ u32 quarter_rtts;
+
+ if (unlikely(hctx->ccid3hctx_rtt < 4)) /* avoid divide-by-zero */
+ return;
+
+ delta = timeval_delta(now, &hctx->ccid3hctx_t_last_win_count);
+ DCCP_BUG_ON(delta < 0);
+
+ quarter_rtts = (u32)delta / (hctx->ccid3hctx_rtt / 4);
+
+ if (quarter_rtts > 0) {
+ hctx->ccid3hctx_t_last_win_count = *now;
+ hctx->ccid3hctx_last_win_count += min_t(u32, quarter_rtts, 5);
+ hctx->ccid3hctx_last_win_count &= 0xF; /* mod 16 */
+
+ ccid3_pr_debug("now at %#X\n", hctx->ccid3hctx_last_win_count);
}
}
static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
{
struct sock *sk = (struct sock *)data;
- unsigned long next_tmout = 0;
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
+ unsigned long t_nfb = USEC_PER_SEC / 5;
bh_lock_sock(sk);
if (sock_owned_by_user(sk)) {
/* Try again later. */
/* XXX: set some sensible MIB */
- sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
- jiffies + HZ / 5);
- goto out;
+ goto restart_timer;
}
- ccid3_pr_debug("%s, sk=%p, state=%s\n", dccp_role(sk), sk,
+ ccid3_pr_debug("%s(%p, state=%s) - entry \n", dccp_role(sk), sk,
ccid3_tx_state_name(hctx->ccid3hctx_state));
-
+
switch (hctx->ccid3hctx_state) {
- case TFRC_SSTATE_TERM:
- goto out;
case TFRC_SSTATE_NO_FBACK:
- /* Halve send rate */
- hctx->ccid3hctx_x /= 2;
- if (hctx->ccid3hctx_x < (hctx->ccid3hctx_s /
- TFRC_MAX_BACK_OFF_TIME))
- hctx->ccid3hctx_x = (hctx->ccid3hctx_s /
- TFRC_MAX_BACK_OFF_TIME);
-
- ccid3_pr_debug("%s, sk=%p, state=%s, updated tx rate to %d "
- "bytes/s\n",
- dccp_role(sk), sk,
+ /* RFC 3448, 4.4: Halve send rate directly */
+ hctx->ccid3hctx_x = max(hctx->ccid3hctx_x / 2,
+ (((__u64)hctx->ccid3hctx_s) << 6) /
+ TFRC_T_MBI);
+
+ ccid3_pr_debug("%s(%p, state=%s), updated tx rate to %u "
+ "bytes/s\n", dccp_role(sk), sk,
ccid3_tx_state_name(hctx->ccid3hctx_state),
- hctx->ccid3hctx_x);
- next_tmout = max_t(u32, 2 * usecs_div(hctx->ccid3hctx_s,
- hctx->ccid3hctx_x),
- TFRC_INITIAL_TIMEOUT);
- /*
- * FIXME - not sure above calculation is correct. See section
- * 5 of CCID3 11 should adjust tx_t_ipi and double that to
- * achieve it really
- */
+ (unsigned)(hctx->ccid3hctx_x >> 6));
+ /* The value of R is still undefined and so we can not recompute
+ * the timout value. Keep initial value as per [RFC 4342, 5]. */
+ t_nfb = TFRC_INITIAL_TIMEOUT;
+ ccid3_update_send_time(hctx);
break;
case TFRC_SSTATE_FBACK:
/*
* Check if IDLE since last timeout and recv rate is less than
- * 4 packets per RTT
+ * 4 packets (in units of 64*bytes/sec) per RTT
*/
if (!hctx->ccid3hctx_idle ||
- (hctx->ccid3hctx_x_recv >=
- 4 * usecs_div(hctx->ccid3hctx_s, hctx->ccid3hctx_rtt))) {
- ccid3_pr_debug("%s, sk=%p, state=%s, not idle\n",
+ (hctx->ccid3hctx_x_recv >= 4 *
+ scaled_div(((__u64)hctx->ccid3hctx_s) << 6,
+ hctx->ccid3hctx_rtt))) {
+ struct timeval now;
+
+ ccid3_pr_debug("%s(%p, state=%s), not idle\n",
dccp_role(sk), sk,
- ccid3_tx_state_name(hctx->ccid3hctx_state));
- /* Halve sending rate */
+ ccid3_tx_state_name(hctx->ccid3hctx_state));
- /* If (X_calc > 2 * X_recv)
+ /*
+ * Modify the cached value of X_recv [RFC 3448, 4.4]
+ *
+ * If (p == 0 || X_calc > 2 * X_recv)
* X_recv = max(X_recv / 2, s / (2 * t_mbi));
* Else
* X_recv = X_calc / 4;
+ *
+ * Note that X_recv is scaled by 2^6 while X_calc is not
*/
- BUG_ON(hctx->ccid3hctx_p >= TFRC_SMALLEST_P &&
- hctx->ccid3hctx_x_calc == 0);
-
- /* check also if p is zero -> x_calc is infinity? */
- if (hctx->ccid3hctx_p < TFRC_SMALLEST_P ||
- hctx->ccid3hctx_x_calc > 2 * hctx->ccid3hctx_x_recv)
- hctx->ccid3hctx_x_recv = max_t(u32, hctx->ccid3hctx_x_recv / 2,
- hctx->ccid3hctx_s / (2 * TFRC_MAX_BACK_OFF_TIME));
- else
- hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc / 4;
-
- /* Update sending rate */
- ccid3_hc_tx_update_x(sk);
+ BUG_ON(hctx->ccid3hctx_p && !hctx->ccid3hctx_x_calc);
+
+ if (hctx->ccid3hctx_p == 0 ||
+ (hctx->ccid3hctx_x_calc >
+ (hctx->ccid3hctx_x_recv >> 5))) {
+
+ hctx->ccid3hctx_x_recv =
+ max(hctx->ccid3hctx_x_recv / 2,
+ (((__u64)hctx->ccid3hctx_s) << 6) /
+ (2 * TFRC_T_MBI));
+
+ if (hctx->ccid3hctx_p == 0)
+ dccp_timestamp(sk, &now);
+ } else {
+ hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc;
+ hctx->ccid3hctx_x_recv <<= 4;
+ }
+ /* Now recalculate X [RFC 3448, 4.3, step (4)] */
+ ccid3_hc_tx_update_x(sk, &now);
}
/*
* Schedule no feedback timer to expire in
- * max(4 * R, 2 * s / X)
+ * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi)
+ * See comments in packet_recv() regarding the value of t_RTO.
*/
- next_tmout = max_t(u32, hctx->ccid3hctx_t_rto,
- 2 * usecs_div(hctx->ccid3hctx_s,
- hctx->ccid3hctx_x));
+ t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
break;
- default:
- printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
- __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
- dump_stack();
+ case TFRC_SSTATE_NO_SENT:
+ DCCP_BUG("%s(%p) - Illegal state NO_SENT", dccp_role(sk), sk);
+ /* fall through */
+ case TFRC_SSTATE_TERM:
goto out;
}
- sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
- jiffies + max_t(u32, 1, usecs_to_jiffies(next_tmout)));
hctx->ccid3hctx_idle = 1;
+
+restart_timer:
+ sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
+ jiffies + usecs_to_jiffies(t_nfb));
out:
bh_unlock_sock(sk);
sock_put(sk);
}
-static int ccid3_hc_tx_send_packet(struct sock *sk,
- struct sk_buff *skb, int len)
+/*
+ * returns
+ * > 0: delay (in msecs) that should pass before actually sending
+ * = 0: can send immediately
+ * < 0: error condition; do not send packet
+ */
+static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
{
struct dccp_sock *dp = dccp_sk(sk);
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
- struct dccp_tx_hist_entry *new_packet;
struct timeval now;
- long delay;
- int rc = -ENOTCONN;
+ suseconds_t delay;
- BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM);
+ BUG_ON(hctx == NULL);
- /* Check if pure ACK or Terminating*/
/*
- * XXX: We only call this function for DATA and DATAACK, on, these
- * packets can have zero length, but why the comment about "pure ACK"?
+ * This function is called only for Data and DataAck packets. Sending
+ * zero-sized Data(Ack)s is theoretically possible, but for congestion
+ * control this case is pathological - ignore it.
*/
- if (unlikely(len == 0))
- goto out;
-
- /* See if last packet allocated was not sent */
- new_packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist);
- if (new_packet == NULL || new_packet->dccphtx_sent) {
- new_packet = dccp_tx_hist_entry_new(ccid3_tx_hist,
- SLAB_ATOMIC);
-
- rc = -ENOBUFS;
- if (unlikely(new_packet == NULL)) {
- LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, not enough "
- "mem to add to history, send refused\n",
- __FUNCTION__, dccp_role(sk), sk);
- goto out;
- }
-
- dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, new_packet);
- }
+ if (unlikely(skb->len == 0))
+ return -EBADMSG;
dccp_timestamp(sk, &now);
switch (hctx->ccid3hctx_state) {
case TFRC_SSTATE_NO_SENT:
- hctx->ccid3hctx_no_feedback_timer.function = ccid3_hc_tx_no_feedback_timer;
- hctx->ccid3hctx_no_feedback_timer.data = (unsigned long)sk;
sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
- jiffies + usecs_to_jiffies(TFRC_INITIAL_TIMEOUT));
+ (jiffies +
+ usecs_to_jiffies(TFRC_INITIAL_TIMEOUT)));
hctx->ccid3hctx_last_win_count = 0;
hctx->ccid3hctx_t_last_win_count = now;
ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);
- hctx->ccid3hctx_t_ipi = TFRC_INITIAL_IPI;
- /* Set nominal send time for initial packet */
+ /* Set initial sending rate X/s to 1pps (X is scaled by 2^6) */
+ ccid3_hc_tx_update_s(hctx, skb->len);
+ hctx->ccid3hctx_x = hctx->ccid3hctx_s;
+ hctx->ccid3hctx_x <<= 6;
+
+ /* 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 */
+ hctx->ccid3hctx_delta = TFRC_OPSYS_HALF_TIME_GRAN;
+
+ /* Set t_0 for initial packet */
hctx->ccid3hctx_t_nom = now;
- timeval_add_usecs(&hctx->ccid3hctx_t_nom,
- hctx->ccid3hctx_t_ipi);
- ccid3_calc_new_delta(hctx);
- rc = 0;
break;
case TFRC_SSTATE_NO_FBACK:
case TFRC_SSTATE_FBACK:
- delay = (timeval_delta(&now, &hctx->ccid3hctx_t_nom) -
- hctx->ccid3hctx_delta);
- delay /= -1000;
- /* divide by -1000 is to convert to ms and get sign right */
- rc = delay > 0 ? delay : 0;
- break;
- default:
- printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
- __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
- dump_stack();
- rc = -EINVAL;
+ delay = timeval_delta(&hctx->ccid3hctx_t_nom, &now);
+ /*
+ * Scheduling of packet transmissions [RFC 3448, 4.6]
+ *
+ * if (t_now > t_nom - delta)
+ * // send the packet now
+ * else
+ * // send the packet in (t_nom - t_now) milliseconds.
+ */
+ if (delay - (suseconds_t)hctx->ccid3hctx_delta >= 0)
+ return delay / 1000L;
+
+ ccid3_hc_tx_update_win_count(hctx, &now);
break;
+ case TFRC_SSTATE_TERM:
+ DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk);
+ return -EINVAL;
}
- /* Can we send? if so add options and add to packet history */
- if (rc == 0) {
- dp->dccps_hc_tx_insert_options = 1;
- new_packet->dccphtx_ccval =
- DCCP_SKB_CB(skb)->dccpd_ccval =
- hctx->ccid3hctx_last_win_count;
- }
-out:
- return rc;
+ /* prepare to send now (add options etc.) */
+ dp->dccps_hc_tx_insert_options = 1;
+ DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count;
+
+ /* set the nominal send time for the next following packet */
+ timeval_add_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi);
+
+ return 0;
}
-static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, int len)
+static void ccid3_hc_tx_packet_sent(struct sock *sk, int more,
+ unsigned int len)
{
- const struct dccp_sock *dp = dccp_sk(sk);
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
struct timeval now;
+ struct dccp_tx_hist_entry *packet;
- BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM);
-
- dccp_timestamp(sk, &now);
-
- /* check if we have sent a data packet */
- if (len > 0) {
- unsigned long quarter_rtt;
- struct dccp_tx_hist_entry *packet;
-
- packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist);
- if (unlikely(packet == NULL)) {
- LIMIT_NETDEBUG(KERN_WARNING "%s: packet doesn't "
- "exists in history!\n", __FUNCTION__);
- return;
- }
- if (unlikely(packet->dccphtx_sent)) {
- LIMIT_NETDEBUG(KERN_WARNING "%s: no unsent packet in "
- "history!\n", __FUNCTION__);
- return;
- }
- packet->dccphtx_tstamp = now;
- packet->dccphtx_seqno = dp->dccps_gss;
- /*
- * Check if win_count have changed
- * Algorithm in "8.1. Window Counter Valuer" in
- * draft-ietf-dccp-ccid3-11.txt
- */
- quarter_rtt = timeval_delta(&now, &hctx->ccid3hctx_t_last_win_count);
- if (likely(hctx->ccid3hctx_rtt > 8))
- quarter_rtt /= hctx->ccid3hctx_rtt / 4;
-
- if (quarter_rtt > 0) {
- hctx->ccid3hctx_t_last_win_count = now;
- hctx->ccid3hctx_last_win_count = (hctx->ccid3hctx_last_win_count +
- min_t(unsigned long, quarter_rtt, 5)) % 16;
- ccid3_pr_debug("%s, sk=%p, window changed from "
- "%u to %u!\n",
- dccp_role(sk), sk,
- packet->dccphtx_ccval,
- hctx->ccid3hctx_last_win_count);
- }
+ BUG_ON(hctx == NULL);
- hctx->ccid3hctx_idle = 0;
- packet->dccphtx_rtt = hctx->ccid3hctx_rtt;
- packet->dccphtx_sent = 1;
- } else
- ccid3_pr_debug("%s, sk=%p, seqno=%llu NOT inserted!\n",
- dccp_role(sk), sk, dp->dccps_gss);
+ ccid3_hc_tx_update_s(hctx, len);
- switch (hctx->ccid3hctx_state) {
- case TFRC_SSTATE_NO_SENT:
- /* if first wasn't pure ack */
- if (len != 0)
- printk(KERN_CRIT "%s: %s, First packet sent is noted "
- "as a data packet\n",
- __FUNCTION__, dccp_role(sk));
+ packet = dccp_tx_hist_entry_new(ccid3_tx_hist, GFP_ATOMIC);
+ if (unlikely(packet == NULL)) {
+ DCCP_CRIT("packet history - out of memory!");
return;
- case TFRC_SSTATE_NO_FBACK:
- case TFRC_SSTATE_FBACK:
- if (len > 0) {
- hctx->ccid3hctx_t_nom = now;
- ccid3_calc_new_t_ipi(hctx);
- ccid3_calc_new_delta(hctx);
- timeval_add_usecs(&hctx->ccid3hctx_t_nom,
- hctx->ccid3hctx_t_ipi);
- }
- break;
- default:
- printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
- __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
- dump_stack();
- break;
}
+ dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, packet);
+
+ dccp_timestamp(sk, &now);
+ packet->dccphtx_tstamp = now;
+ packet->dccphtx_seqno = dccp_sk(sk)->dccps_gss;
+ packet->dccphtx_rtt = hctx->ccid3hctx_rtt;
+ packet->dccphtx_sent = 1;
+ hctx->ccid3hctx_idle = 0;
}
static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
struct ccid3_options_received *opt_recv;
struct dccp_tx_hist_entry *packet;
struct timeval now;
- unsigned long next_tmout;
- u32 t_elapsed;
+ unsigned long t_nfb;
u32 pinv;
- u32 x_recv;
- u32 r_sample;
+ suseconds_t r_sample, t_elapsed;
- BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM);
+ BUG_ON(hctx == NULL);
/* we are only interested in ACKs */
if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK ||
opt_recv = &hctx->ccid3hctx_options_received;
- t_elapsed = dp->dccps_options_received.dccpor_elapsed_time * 10;
- x_recv = opt_recv->ccid3or_receive_rate;
- pinv = opt_recv->ccid3or_loss_event_rate;
-
switch (hctx->ccid3hctx_state) {
- case TFRC_SSTATE_NO_SENT:
- /* FIXME: what to do here? */
- return;
case TFRC_SSTATE_NO_FBACK:
case TFRC_SSTATE_FBACK:
- /* Calculate new round trip sample by
- * R_sample = (now - t_recvdata) - t_delay */
- /* get t_recvdata from history */
+ /* get packet from history to look up t_recvdata */
packet = dccp_tx_hist_find_entry(&hctx->ccid3hctx_hist,
- DCCP_SKB_CB(skb)->dccpd_ack_seq);
+ DCCP_SKB_CB(skb)->dccpd_ack_seq);
if (unlikely(packet == NULL)) {
- LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, seqno "
- "%llu(%s) does't exist in history!\n",
- __FUNCTION__, dccp_role(sk), sk,
+ DCCP_WARN("%s(%p), seqno %llu(%s) doesn't exist "
+ "in history!\n", dccp_role(sk), sk,
(unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq,
dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type));
return;
}
- /* Update RTT */
+ /* Update receive rate in units of 64 * bytes/second */
+ hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate;
+ hctx->ccid3hctx_x_recv <<= 6;
+
+ /* Update loss event rate */
+ pinv = opt_recv->ccid3or_loss_event_rate;
+ if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */
+ hctx->ccid3hctx_p = 0;
+ else /* can not exceed 100% */
+ hctx->ccid3hctx_p = 1000000 / pinv;
+
dccp_timestamp(sk, &now);
- r_sample = timeval_delta(&now, &packet->dccphtx_tstamp);
+
+ /*
+ * Calculate new round trip sample as per [RFC 3448, 4.3] by
+ * R_sample = (now - t_recvdata) - t_elapsed
+ */
+ r_sample = timeval_delta(&now, &packet->dccphtx_tstamp);
+ t_elapsed = dp->dccps_options_received.dccpor_elapsed_time * 10;
+
+ DCCP_BUG_ON(r_sample < 0);
if (unlikely(r_sample <= t_elapsed))
- LIMIT_NETDEBUG(KERN_WARNING "%s: r_sample=%uus, "
- "t_elapsed=%uus\n",
- __FUNCTION__, r_sample, t_elapsed);
+ DCCP_WARN("WARNING: r_sample=%dus <= t_elapsed=%dus\n",
+ (int)r_sample, (int)t_elapsed);
else
r_sample -= t_elapsed;
+ CCID3_RTT_SANITY_CHECK(r_sample);
- /* Update RTT estimate by
+ /* Update RTT estimate by
* If (No feedback recv)
* R = R_sample;
* Else
* q is a constant, RFC 3448 recomments 0.9
*/
if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
- ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
- hctx->ccid3hctx_rtt = r_sample;
- } else
- hctx->ccid3hctx_rtt = (hctx->ccid3hctx_rtt * 9) / 10 +
- r_sample / 10;
-
- ccid3_pr_debug("%s, sk=%p, New RTT estimate=%uus, "
- "r_sample=%us\n", dccp_role(sk), sk,
- hctx->ccid3hctx_rtt, r_sample);
-
- /* Update timeout interval */
- hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt,
- USEC_PER_SEC);
+ /*
+ * Larger Initial Windows [RFC 4342, sec. 5]
+ * We deviate in that we use `s' instead of `MSS'.
+ */
+ __u64 w_init = min(4 * hctx->ccid3hctx_s,
+ max(2 * hctx->ccid3hctx_s, 4380));
+ hctx->ccid3hctx_rtt = r_sample;
+ hctx->ccid3hctx_x = scaled_div(w_init << 6, r_sample);
+ hctx->ccid3hctx_t_ld = now;
- /* Update receive rate */
- hctx->ccid3hctx_x_recv = x_recv;/* X_recv in bytes per sec */
+ ccid3_update_send_time(hctx);
- /* Update loss event rate */
- if (pinv == ~0 || pinv == 0)
- hctx->ccid3hctx_p = 0;
- else {
- hctx->ccid3hctx_p = 1000000 / pinv;
+ ccid3_pr_debug("%s(%p), s=%u, w_init=%llu, "
+ "R_sample=%dus, X=%u\n", dccp_role(sk),
+ sk, hctx->ccid3hctx_s, w_init,
+ (int)r_sample,
+ (unsigned)(hctx->ccid3hctx_x >> 6));
- if (hctx->ccid3hctx_p < TFRC_SMALLEST_P) {
- hctx->ccid3hctx_p = TFRC_SMALLEST_P;
- ccid3_pr_debug("%s, sk=%p, Smallest p used!\n",
- dccp_role(sk), sk);
- }
+ ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
+ } else {
+ hctx->ccid3hctx_rtt = (9 * hctx->ccid3hctx_rtt +
+ (u32)r_sample) / 10;
+
+ /* Update sending rate (step 4 of [RFC 3448, 4.3]) */
+ if (hctx->ccid3hctx_p > 0)
+ hctx->ccid3hctx_x_calc =
+ tfrc_calc_x(hctx->ccid3hctx_s,
+ hctx->ccid3hctx_rtt,
+ hctx->ccid3hctx_p);
+ ccid3_hc_tx_update_x(sk, &now);
+
+ ccid3_pr_debug("%s(%p), RTT=%uus (sample=%dus), s=%u, "
+ "p=%u, X_calc=%u, X_recv=%u, X=%u\n",
+ dccp_role(sk),
+ sk, hctx->ccid3hctx_rtt, (int)r_sample,
+ hctx->ccid3hctx_s, hctx->ccid3hctx_p,
+ hctx->ccid3hctx_x_calc,
+ (unsigned)(hctx->ccid3hctx_x_recv >> 6),
+ (unsigned)(hctx->ccid3hctx_x >> 6));
}
/* unschedule no feedback timer */
sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
- /* Update sending rate */
- ccid3_hc_tx_update_x(sk);
-
- /* Update next send time */
- timeval_sub_usecs(&hctx->ccid3hctx_t_nom,
- hctx->ccid3hctx_t_ipi);
- ccid3_calc_new_t_ipi(hctx);
- timeval_add_usecs(&hctx->ccid3hctx_t_nom,
- hctx->ccid3hctx_t_ipi);
- ccid3_calc_new_delta(hctx);
-
/* remove all packets older than the one acked from history */
dccp_tx_hist_purge_older(ccid3_tx_hist,
&hctx->ccid3hctx_hist, packet);
/*
- * As we have calculated new ipi, delta, t_nom it is possible that
- * we now can send a packet, so wake up dccp_wait_for_ccids.
+ * As we have calculated new ipi, delta, t_nom it is possible
+ * that we now can send a packet, so wake up dccp_wait_for_ccid
*/
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.
+ */
+ hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt,
+ CONFIG_IP_DCCP_CCID3_RTO *
+ (USEC_PER_SEC/1000));
/*
* Schedule no feedback timer to expire in
- * max(4 * R, 2 * s / X)
+ * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi)
*/
- next_tmout = max(hctx->ccid3hctx_t_rto,
- 2 * usecs_div(hctx->ccid3hctx_s,
- hctx->ccid3hctx_x));
-
- ccid3_pr_debug("%s, sk=%p, Scheduled no feedback timer to "
+ t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
+
+ ccid3_pr_debug("%s(%p), Scheduled no feedback timer to "
"expire in %lu jiffies (%luus)\n",
- dccp_role(sk), sk,
- usecs_to_jiffies(next_tmout), next_tmout);
+ dccp_role(sk),
+ sk, usecs_to_jiffies(t_nfb), t_nfb);
- sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
- jiffies + max_t(u32, 1, usecs_to_jiffies(next_tmout)));
+ sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
+ jiffies + usecs_to_jiffies(t_nfb));
/* set idle flag */
- hctx->ccid3hctx_idle = 1;
+ hctx->ccid3hctx_idle = 1;
break;
- default:
- printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
- __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
- dump_stack();
+ case TFRC_SSTATE_NO_SENT:
+ /*
+ * XXX when implementing bidirectional rx/tx check this again
+ */
+ DCCP_WARN("Illegal ACK received - no packet sent\n");
+ /* fall through */
+ case TFRC_SSTATE_TERM: /* ignore feedback when closing */
break;
}
}
-static void ccid3_hc_tx_insert_options(struct sock *sk, struct sk_buff *skb)
-{
- const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
-
- BUG_ON(hctx == NULL);
-
- if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN))
- return;
-
- DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count;
-}
-
static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
unsigned char len, u16 idx,
unsigned char *value)
switch (option) {
case TFRC_OPT_LOSS_EVENT_RATE:
if (unlikely(len != 4)) {
- LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, invalid "
- "len for TFRC_OPT_LOSS_EVENT_RATE\n",
- __FUNCTION__, dccp_role(sk), sk);
+ DCCP_WARN("%s(%p), invalid len %d "
+ "for TFRC_OPT_LOSS_EVENT_RATE\n",
+ dccp_role(sk), sk, len);
rc = -EINVAL;
} else {
- opt_recv->ccid3or_loss_event_rate = ntohl(*(u32 *)value);
- ccid3_pr_debug("%s, sk=%p, LOSS_EVENT_RATE=%u\n",
+ opt_recv->ccid3or_loss_event_rate =
+ ntohl(*(__be32 *)value);
+ ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n",
dccp_role(sk), sk,
opt_recv->ccid3or_loss_event_rate);
}
case TFRC_OPT_LOSS_INTERVALS:
opt_recv->ccid3or_loss_intervals_idx = idx;
opt_recv->ccid3or_loss_intervals_len = len;
- ccid3_pr_debug("%s, sk=%p, LOSS_INTERVALS=(%u, %u)\n",
+ 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)) {
- LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, invalid "
- "len for TFRC_OPT_RECEIVE_RATE\n",
- __FUNCTION__, dccp_role(sk), sk);
+ DCCP_WARN("%s(%p), invalid len %d "
+ "for TFRC_OPT_RECEIVE_RATE\n",
+ dccp_role(sk), sk, len);
rc = -EINVAL;
} else {
- opt_recv->ccid3or_receive_rate = ntohl(*(u32 *)value);
- ccid3_pr_debug("%s, sk=%p, RECEIVE_RATE=%u\n",
+ opt_recv->ccid3or_receive_rate =
+ ntohl(*(__be32 *)value);
+ ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n",
dccp_role(sk), sk,
opt_recv->ccid3or_receive_rate);
}
return rc;
}
-static int ccid3_hc_tx_init(struct sock *sk)
+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;
-
- dp->dccps_hc_tx_ccid_private = kmalloc(sizeof(*hctx), gfp_any());
- if (dp->dccps_hc_tx_ccid_private == NULL)
- return -ENOMEM;
-
- hctx = ccid3_hc_tx_sk(sk);
- memset(hctx, 0, sizeof(*hctx));
-
- 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;
+ struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid);
- /* Set transmission rate to 1 packet per second */
- hctx->ccid3hctx_x = hctx->ccid3hctx_s;
- hctx->ccid3hctx_t_rto = USEC_PER_SEC;
+ hctx->ccid3hctx_s = 0;
+ hctx->ccid3hctx_rtt = 0;
hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT;
INIT_LIST_HEAD(&hctx->ccid3hctx_hist);
+
+ hctx->ccid3hctx_no_feedback_timer.function =
+ ccid3_hc_tx_no_feedback_timer;
+ hctx->ccid3hctx_no_feedback_timer.data = (unsigned long)sk;
init_timer(&hctx->ccid3hctx_no_feedback_timer);
return 0;
static void ccid3_hc_tx_exit(struct sock *sk)
{
- struct dccp_sock *dp = dccp_sk(sk);
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
BUG_ON(hctx == NULL);
/* Empty packet history */
dccp_tx_hist_purge(ccid3_tx_hist, &hctx->ccid3hctx_hist);
-
- kfree(dp->dccps_hc_tx_ccid_private);
- dp->dccps_hc_tx_ccid_private = NULL;
}
/*
* RX Half Connection methods
*/
-/* TFRC receiver states */
-enum ccid3_hc_rx_states {
- TFRC_RSTATE_NO_DATA = 1,
- TFRC_RSTATE_DATA,
- TFRC_RSTATE_TERM = 127,
-};
-
-#ifdef CCID3_DEBUG
+#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state)
{
static char *ccid3_rx_state_names[] = {
}
#endif
-static inline void ccid3_hc_rx_set_state(struct sock *sk,
- enum ccid3_hc_rx_states state)
+static void ccid3_hc_rx_set_state(struct sock *sk,
+ enum ccid3_hc_rx_states state)
{
struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
enum ccid3_hc_rx_states oldstate = hcrx->ccid3hcrx_state;
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);
struct dccp_sock *dp = dccp_sk(sk);
struct dccp_rx_hist_entry *packet;
struct timeval now;
+ suseconds_t delta;
- ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
+ ccid3_pr_debug("%s(%p) - entry \n", dccp_role(sk), sk);
dccp_timestamp(sk, &now);
case TFRC_RSTATE_NO_DATA:
hcrx->ccid3hcrx_x_recv = 0;
break;
- case TFRC_RSTATE_DATA: {
- const u32 delta = timeval_delta(&now,
- &hcrx->ccid3hcrx_tstamp_last_feedback);
- hcrx->ccid3hcrx_x_recv = usecs_div(hcrx->ccid3hcrx_bytes_recv,
- delta);
- }
+ case TFRC_RSTATE_DATA:
+ delta = timeval_delta(&now,
+ &hcrx->ccid3hcrx_tstamp_last_feedback);
+ DCCP_BUG_ON(delta < 0);
+ hcrx->ccid3hcrx_x_recv =
+ scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta);
break;
- default:
- printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
- __FUNCTION__, dccp_role(sk), sk, hcrx->ccid3hcrx_state);
- dump_stack();
+ case TFRC_RSTATE_TERM:
+ DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk);
return;
}
packet = dccp_rx_hist_find_data_packet(&hcrx->ccid3hcrx_hist);
if (unlikely(packet == NULL)) {
- LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, no data packet "
- "in history!\n",
- __FUNCTION__, dccp_role(sk), sk);
+ DCCP_WARN("%s(%p), no data packet in history!\n",
+ dccp_role(sk), sk);
return;
}
hcrx->ccid3hcrx_tstamp_last_feedback = now;
- hcrx->ccid3hcrx_last_counter = packet->dccphrx_ccval;
- hcrx->ccid3hcrx_seqno_last_counter = packet->dccphrx_seqno;
+ hcrx->ccid3hcrx_ccval_last_counter = packet->dccphrx_ccval;
hcrx->ccid3hcrx_bytes_recv = 0;
- /* Convert to multiples of 10us */
- hcrx->ccid3hcrx_elapsed_time =
- timeval_delta(&now, &packet->dccphrx_tstamp) / 10;
+ /* Elapsed time information [RFC 4340, 13.2] in units of 10 * usecs */
+ delta = timeval_delta(&now, &packet->dccphrx_tstamp);
+ DCCP_BUG_ON(delta < 0);
+ hcrx->ccid3hcrx_elapsed_time = delta / 10;
+
if (hcrx->ccid3hcrx_p == 0)
- hcrx->ccid3hcrx_pinv = ~0;
- else
+ hcrx->ccid3hcrx_pinv = ~0U; /* see RFC 4342, 8.5 */
+ else if (hcrx->ccid3hcrx_p > 1000000) {
+ DCCP_WARN("p (%u) > 100%%\n", hcrx->ccid3hcrx_p);
+ hcrx->ccid3hcrx_pinv = 1; /* use 100% in this case */
+ } else
hcrx->ccid3hcrx_pinv = 1000000 / hcrx->ccid3hcrx_p;
+
dp->dccps_hc_rx_insert_options = 1;
dccp_send_ack(sk);
}
-static void ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb)
+static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb)
{
const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
- u32 x_recv, pinv;
+ __be32 x_recv, pinv;
BUG_ON(hcrx == NULL);
if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN))
- return;
+ return 0;
- DCCP_SKB_CB(skb)->dccpd_ccval = hcrx->ccid3hcrx_last_counter;
+ DCCP_SKB_CB(skb)->dccpd_ccval = hcrx->ccid3hcrx_ccval_last_counter;
if (dccp_packet_without_ack(skb))
- return;
-
- if (hcrx->ccid3hcrx_elapsed_time != 0)
- dccp_insert_option_elapsed_time(sk, skb,
- hcrx->ccid3hcrx_elapsed_time);
- dccp_insert_option_timestamp(sk, skb);
+ return 0;
+
x_recv = htonl(hcrx->ccid3hcrx_x_recv);
pinv = htonl(hcrx->ccid3hcrx_pinv);
- dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE,
- &pinv, sizeof(pinv));
- dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE,
- &x_recv, sizeof(x_recv));
+
+ if ((hcrx->ccid3hcrx_elapsed_time != 0 &&
+ dccp_insert_option_elapsed_time(sk, skb,
+ hcrx->ccid3hcrx_elapsed_time)) ||
+ dccp_insert_option_timestamp(sk, skb) ||
+ dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE,
+ &pinv, sizeof(pinv)) ||
+ dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE,
+ &x_recv, sizeof(x_recv)))
+ return -1;
+
+ return 0;
}
/* calculate first loss interval
{
struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
struct dccp_rx_hist_entry *entry, *next, *tail = NULL;
- u32 rtt, delta, x_recv, fval, p, tmp2;
+ u32 x_recv, p;
+ suseconds_t rtt, delta;
struct timeval tstamp = { 0, };
int interval = 0;
int win_count = 0;
int step = 0;
- u64 tmp1;
+ u64 fval;
list_for_each_entry_safe(entry, next, &hcrx->ccid3hcrx_hist,
dccphrx_node) {
}
if (unlikely(step == 0)) {
- LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, packet history "
- "contains no data packets!\n",
- __FUNCTION__, dccp_role(sk), sk);
+ DCCP_WARN("%s(%p), packet history has no data packets!\n",
+ dccp_role(sk), sk);
return ~0;
}
if (unlikely(interval == 0)) {
- LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, Could not find a "
- "win_count interval > 0. Defaulting to 1\n",
- __FUNCTION__, dccp_role(sk), sk);
+ DCCP_WARN("%s(%p), Could not find a win_count interval > 0."
+ "Defaulting to 1\n", dccp_role(sk), sk);
interval = 1;
}
found:
- rtt = timeval_delta(&tstamp, &tail->dccphrx_tstamp) * 4 / interval;
- ccid3_pr_debug("%s, sk=%p, approximated RTT to %uus\n",
- dccp_role(sk), sk, rtt);
- if (rtt == 0)
- rtt = 1;
+ if (!tail) {
+ DCCP_CRIT("tail is null\n");
+ return ~0;
+ }
+
+ delta = timeval_delta(&tstamp, &tail->dccphrx_tstamp);
+ DCCP_BUG_ON(delta < 0);
+
+ rtt = delta * 4 / interval;
+ ccid3_pr_debug("%s(%p), approximated RTT to %dus\n",
+ dccp_role(sk), sk, (int)rtt);
+
+ /*
+ * Determine the length of the first loss interval via inverse lookup.
+ * Assume that X_recv can be computed by the throughput equation
+ * s
+ * X_recv = --------
+ * R * fval
+ * Find some p such that f(p) = fval; return 1/p [RFC 3448, 6.3.1].
+ */
+ if (rtt == 0) { /* would result in divide-by-zero */
+ DCCP_WARN("RTT==0\n");
+ return ~0;
+ }
dccp_timestamp(sk, &tstamp);
delta = timeval_delta(&tstamp, &hcrx->ccid3hcrx_tstamp_last_feedback);
- x_recv = usecs_div(hcrx->ccid3hcrx_bytes_recv, delta);
+ DCCP_BUG_ON(delta <= 0);
+
+ x_recv = scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta);
+ if (x_recv == 0) { /* would also trigger divide-by-zero */
+ DCCP_WARN("X_recv==0\n");
+ if ((x_recv = hcrx->ccid3hcrx_x_recv) == 0) {
+ DCCP_BUG("stored value of X_recv is zero");
+ return ~0;
+ }
+ }
- tmp1 = (u64)x_recv * (u64)rtt;
- do_div(tmp1,10000000);
- tmp2 = (u32)tmp1;
- fval = (hcrx->ccid3hcrx_s * 100000) / tmp2;
- /* do not alter order above or you will get overflow on 32 bit */
+ fval = scaled_div(hcrx->ccid3hcrx_s, rtt);
+ fval = scaled_div32(fval, x_recv);
p = tfrc_calc_x_reverse_lookup(fval);
- ccid3_pr_debug("%s, sk=%p, receive rate=%u bytes/s, implied "
+
+ ccid3_pr_debug("%s(%p), receive rate=%u bytes/s, implied "
"loss rate=%u\n", dccp_role(sk), sk, x_recv, p);
if (p == 0)
return ~0;
else
- return 1000000 / p;
+ return 1000000 / p;
}
static void ccid3_hc_rx_update_li(struct sock *sk, u64 seq_loss, u8 win_loss)
{
struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
+ struct dccp_li_hist_entry *head;
+ u64 seq_temp;
- if (seq_loss != DCCP_MAX_SEQNO + 1 &&
- list_empty(&hcrx->ccid3hcrx_li_hist)) {
- struct dccp_li_hist_entry *li_tail;
+ if (list_empty(&hcrx->ccid3hcrx_li_hist)) {
+ if (!dccp_li_hist_interval_new(ccid3_li_hist,
+ &hcrx->ccid3hcrx_li_hist, seq_loss, win_loss))
+ return;
- li_tail = dccp_li_hist_interval_new(ccid3_li_hist,
- &hcrx->ccid3hcrx_li_hist,
- seq_loss, win_loss);
- if (li_tail == NULL)
+ head = list_entry(hcrx->ccid3hcrx_li_hist.next,
+ struct dccp_li_hist_entry, dccplih_node);
+ head->dccplih_interval = ccid3_hc_rx_calc_first_li(sk);
+ } else {
+ struct dccp_li_hist_entry *entry;
+ struct list_head *tail;
+
+ head = list_entry(hcrx->ccid3hcrx_li_hist.next,
+ struct dccp_li_hist_entry, dccplih_node);
+ /* FIXME win count check removed as was wrong */
+ /* should make this check with receive history */
+ /* and compare there as per section 10.2 of RFC4342 */
+
+ /* new loss event detected */
+ /* calculate last interval length */
+ seq_temp = dccp_delta_seqno(head->dccplih_seqno, seq_loss);
+ entry = dccp_li_hist_entry_new(ccid3_li_hist, GFP_ATOMIC);
+
+ if (entry == NULL) {
+ DCCP_BUG("out of memory - can not allocate entry");
return;
- li_tail->dccplih_interval = ccid3_hc_rx_calc_first_li(sk);
- } else
- LIMIT_NETDEBUG(KERN_WARNING "%s: FIXME: find end of "
- "interval\n", __FUNCTION__);
+ }
+
+ list_add(&entry->dccplih_node, &hcrx->ccid3hcrx_li_hist);
+
+ tail = hcrx->ccid3hcrx_li_hist.prev;
+ list_del(tail);
+ kmem_cache_free(ccid3_li_hist->dccplih_slab, tail);
+
+ /* Create the newest interval */
+ entry->dccplih_seqno = seq_loss;
+ entry->dccplih_interval = seq_temp;
+ entry->dccplih_win_count = win_loss;
+ }
}
-static void ccid3_hc_rx_detect_loss(struct sock *sk)
+static int ccid3_hc_rx_detect_loss(struct sock *sk,
+ struct dccp_rx_hist_entry *packet)
{
struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
- u8 win_loss;
- const u64 seq_loss = dccp_rx_hist_detect_loss(&hcrx->ccid3hcrx_hist,
- &hcrx->ccid3hcrx_li_hist,
- &win_loss);
+ struct dccp_rx_hist_entry *rx_hist =
+ dccp_rx_hist_head(&hcrx->ccid3hcrx_hist);
+ u64 seqno = packet->dccphrx_seqno;
+ u64 tmp_seqno;
+ int loss = 0;
+ u8 ccval;
+
+
+ tmp_seqno = hcrx->ccid3hcrx_seqno_nonloss;
+
+ if (!rx_hist ||
+ follows48(packet->dccphrx_seqno, hcrx->ccid3hcrx_seqno_nonloss)) {
+ hcrx->ccid3hcrx_seqno_nonloss = seqno;
+ hcrx->ccid3hcrx_ccval_nonloss = packet->dccphrx_ccval;
+ goto detect_out;
+ }
+
+
+ while (dccp_delta_seqno(hcrx->ccid3hcrx_seqno_nonloss, seqno)
+ > TFRC_RECV_NUM_LATE_LOSS) {
+ loss = 1;
+ ccid3_hc_rx_update_li(sk, hcrx->ccid3hcrx_seqno_nonloss,
+ hcrx->ccid3hcrx_ccval_nonloss);
+ tmp_seqno = hcrx->ccid3hcrx_seqno_nonloss;
+ dccp_inc_seqno(&tmp_seqno);
+ hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno;
+ dccp_inc_seqno(&tmp_seqno);
+ while (dccp_rx_hist_find_entry(&hcrx->ccid3hcrx_hist,
+ tmp_seqno, &ccval)) {
+ hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno;
+ hcrx->ccid3hcrx_ccval_nonloss = ccval;
+ dccp_inc_seqno(&tmp_seqno);
+ }
+ }
+
+ /* FIXME - this code could be simplified with above while */
+ /* but works at moment */
+ if (follows48(packet->dccphrx_seqno, hcrx->ccid3hcrx_seqno_nonloss)) {
+ hcrx->ccid3hcrx_seqno_nonloss = seqno;
+ hcrx->ccid3hcrx_ccval_nonloss = packet->dccphrx_ccval;
+ }
- ccid3_hc_rx_update_li(sk, seq_loss, win_loss);
+detect_out:
+ dccp_rx_hist_add_packet(ccid3_rx_hist, &hcrx->ccid3hcrx_hist,
+ &hcrx->ccid3hcrx_li_hist, packet,
+ hcrx->ccid3hcrx_seqno_nonloss);
+ return loss;
}
static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
const struct dccp_options_received *opt_recv;
struct dccp_rx_hist_entry *packet;
struct timeval now;
- u8 win_count;
- u32 p_prev, r_sample, t_elapsed;
- int ins;
+ u32 p_prev, rtt_prev;
+ suseconds_t r_sample, t_elapsed;
+ int loss, payload_size;
- BUG_ON(hcrx == NULL ||
- !(hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA ||
- hcrx->ccid3hcrx_state == TFRC_RSTATE_DATA));
+ BUG_ON(hcrx == NULL);
opt_recv = &dccp_sk(sk)->dccps_options_received;
case DCCP_PKT_DATAACK:
if (opt_recv->dccpor_timestamp_echo == 0)
break;
- p_prev = hcrx->ccid3hcrx_rtt;
+ rtt_prev = hcrx->ccid3hcrx_rtt;
dccp_timestamp(sk, &now);
timeval_sub_usecs(&now, opt_recv->dccpor_timestamp_echo * 10);
r_sample = timeval_usecs(&now);
t_elapsed = opt_recv->dccpor_elapsed_time * 10;
+ DCCP_BUG_ON(r_sample < 0);
if (unlikely(r_sample <= t_elapsed))
- LIMIT_NETDEBUG(KERN_WARNING "%s: r_sample=%uus, "
- "t_elapsed=%uus\n",
- __FUNCTION__, r_sample, t_elapsed);
+ DCCP_WARN("r_sample=%ldus, t_elapsed=%ldus\n",
+ r_sample, t_elapsed);
else
r_sample -= t_elapsed;
+ CCID3_RTT_SANITY_CHECK(r_sample);
if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
hcrx->ccid3hcrx_rtt = r_sample;
hcrx->ccid3hcrx_rtt = (hcrx->ccid3hcrx_rtt * 9) / 10 +
r_sample / 10;
- if (p_prev != hcrx->ccid3hcrx_rtt)
- ccid3_pr_debug("%s, New RTT=%luus, elapsed time=%u\n",
- dccp_role(sk), hcrx->ccid3hcrx_rtt,
+ if (rtt_prev != hcrx->ccid3hcrx_rtt)
+ ccid3_pr_debug("%s(%p), New RTT=%uus, elapsed time=%u\n",
+ dccp_role(sk), sk, hcrx->ccid3hcrx_rtt,
opt_recv->dccpor_elapsed_time);
break;
case DCCP_PKT_DATA:
}
packet = dccp_rx_hist_entry_new(ccid3_rx_hist, sk, opt_recv->dccpor_ndp,
- skb, SLAB_ATOMIC);
+ skb, GFP_ATOMIC);
if (unlikely(packet == NULL)) {
- LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, Not enough mem to "
- "add rx packet to history, consider it lost!\n",
- __FUNCTION__, dccp_role(sk), sk);
+ DCCP_WARN("%s(%p), Not enough mem to add rx packet "
+ "to history, consider it lost!\n", dccp_role(sk), sk);
return;
}
- win_count = packet->dccphrx_ccval;
-
- ins = dccp_rx_hist_add_packet(ccid3_rx_hist, &hcrx->ccid3hcrx_hist,
- &hcrx->ccid3hcrx_li_hist, packet);
+ loss = ccid3_hc_rx_detect_loss(sk, packet);
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 "
- "feedback\n",
- dccp_role(sk), sk,
+ ccid3_pr_debug("%s(%p, state=%s), skb=%p, sending initial "
+ "feedback\n", dccp_role(sk), sk,
dccp_state_name(sk->sk_state), skb);
ccid3_hc_rx_send_feedback(sk);
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;
- if (ins != 0)
+ hcrx->ccid3hcrx_bytes_recv += payload_size;
+ if (loss)
break;
dccp_timestamp(sk, &now);
- if (timeval_delta(&now, &hcrx->ccid3hcrx_tstamp_last_ack) >=
- hcrx->ccid3hcrx_rtt) {
+ if ((timeval_delta(&now, &hcrx->ccid3hcrx_tstamp_last_ack) -
+ (suseconds_t)hcrx->ccid3hcrx_rtt) >= 0) {
hcrx->ccid3hcrx_tstamp_last_ack = now;
ccid3_hc_rx_send_feedback(sk);
}
return;
- default:
- printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
- __FUNCTION__, dccp_role(sk), sk, hcrx->ccid3hcrx_state);
- dump_stack();
+ case TFRC_RSTATE_TERM:
+ DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk);
return;
}
/* Dealing with packet loss */
- ccid3_pr_debug("%s, sk=%p(%s), data loss! Reacting...\n",
+ ccid3_pr_debug("%s(%p, state=%s), data loss! Reacting...\n",
dccp_role(sk), sk, dccp_state_name(sk->sk_state));
- ccid3_hc_rx_detect_loss(sk);
p_prev = hcrx->ccid3hcrx_p;
/* Calculate loss event rate */
/* Scaling up by 1000000 as fixed decimal */
if (i_mean != 0)
hcrx->ccid3hcrx_p = 1000000 / i_mean;
- }
+ } else
+ DCCP_BUG("empty loss history");
if (hcrx->ccid3hcrx_p > p_prev) {
ccid3_hc_rx_send_feedback(sk);
}
}
-static int ccid3_hc_rx_init(struct sock *sk)
+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;
-
- ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
+ struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid);
- dp->dccps_hc_rx_ccid_private = kmalloc(sizeof(*hcrx), gfp_any());
- if (dp->dccps_hc_rx_ccid_private == NULL)
- return -ENOMEM;
-
- hcrx = ccid3_hc_rx_sk(sk);
- memset(hcrx, 0, sizeof(*hcrx));
-
- 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;
+ ccid3_pr_debug("entry\n");
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_rtt = 5000; /* XXX 5ms for now... */
+ hcrx->ccid3hcrx_s = 0;
+ hcrx->ccid3hcrx_rtt = 0;
return 0;
}
static void ccid3_hc_rx_exit(struct sock *sk)
{
struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
- struct dccp_sock *dp = dccp_sk(sk);
BUG_ON(hcrx == NULL);
/* Empty loss interval history */
dccp_li_hist_purge(ccid3_li_hist, &hcrx->ccid3hcrx_li_hist);
-
- kfree(dp->dccps_hc_rx_ccid_private);
- dp->dccps_hc_rx_ccid_private = NULL;
}
static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info)
BUG_ON(hcrx == NULL);
- info->tcpi_ca_state = hcrx->ccid3hcrx_state;
- info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
- info->tcpi_rcv_rtt = hcrx->ccid3hcrx_rtt;
+ info->tcpi_ca_state = hcrx->ccid3hcrx_state;
+ info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
+ info->tcpi_rcv_rtt = hcrx->ccid3hcrx_rtt;
}
static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info)
return 0;
}
-static struct ccid ccid3 = {
- .ccid_id = 3,
+static struct ccid_operations ccid3 = {
+ .ccid_id = DCCPC_CCID3,
.ccid_name = "ccid3",
.ccid_owner = THIS_MODULE,
- .ccid_init = ccid3_init,
- .ccid_exit = ccid3_exit,
+ .ccid_hc_tx_obj_size = sizeof(struct ccid3_hc_tx_sock),
.ccid_hc_tx_init = ccid3_hc_tx_init,
.ccid_hc_tx_exit = ccid3_hc_tx_exit,
.ccid_hc_tx_send_packet = ccid3_hc_tx_send_packet,
.ccid_hc_tx_packet_sent = ccid3_hc_tx_packet_sent,
.ccid_hc_tx_packet_recv = ccid3_hc_tx_packet_recv,
- .ccid_hc_tx_insert_options = ccid3_hc_tx_insert_options,
.ccid_hc_tx_parse_options = ccid3_hc_tx_parse_options,
+ .ccid_hc_rx_obj_size = sizeof(struct ccid3_hc_rx_sock),
.ccid_hc_rx_init = ccid3_hc_rx_init,
.ccid_hc_rx_exit = ccid3_hc_rx_exit,
.ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options,
.ccid_hc_rx_getsockopt = ccid3_hc_rx_getsockopt,
.ccid_hc_tx_getsockopt = ccid3_hc_tx_getsockopt,
};
-
+
+#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
module_param(ccid3_debug, int, 0444);
MODULE_PARM_DESC(ccid3_debug, "Enable debug messages");
+#endif
static __init int ccid3_module_init(void)
{
goto out_free_tx;
rc = ccid_register(&ccid3);
- if (rc != 0)
+ if (rc != 0)
goto out_free_loss_interval_history;
out:
return rc;
static __exit void ccid3_module_exit(void)
{
-#ifdef CONFIG_IP_DCCP_UNLOAD_HACK
- /*
- * Hack to use while developing, so that we get rid of the control
- * sock, that is what keeps a refcount on dccp.ko -acme
- */
- extern void dccp_ctl_sock_exit(void);
-
- dccp_ctl_sock_exit();
-#endif
ccid_unregister(&ccid3);
if (ccid3_tx_hist != NULL) {
}
module_exit(ccid3_module_exit);
-MODULE_AUTHOR("Ian McDonald <iam4@cs.waikato.ac.nz>, "
+MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>, "
"Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
MODULE_DESCRIPTION("DCCP TFRC CCID3 CCID");
MODULE_LICENSE("GPL");
git://git.onelab.eu / linux-2.6.git / blobdiff