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authorGerrit Renker <gerrit@erg.abdn.ac.uk>2008-09-09 13:27:22 +0200
committerGerrit Renker <gerrit@erg.abdn.ac.uk>2008-09-09 13:27:22 +0200
commit410e27a49bb98bc7fa3ff5fc05cc313817b9f253 (patch)
tree88bb1fcf84f9ebfa4299c9a8dcd9e6330b358446 /net/dccp/ccids/ccid3.c
parent0a68a20cc3eafa73bb54097c28b921147d7d3685 (diff)
downloadlinux-410e27a49bb98bc7fa3ff5fc05cc313817b9f253.tar.bz2
This reverts "Merge branch 'dccp' of git://eden-feed.erg.abdn.ac.uk/dccp_exp"
as it accentally contained the wrong set of patches. These will be submitted separately. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Diffstat (limited to 'net/dccp/ccids/ccid3.c')
-rw-r--r--net/dccp/ccids/ccid3.c762
1 files changed, 461 insertions, 301 deletions
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index 06cfdad84a6a..3b8bd7ca6761 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -49,41 +49,75 @@ static int ccid3_debug;
/*
* Transmitter Half-Connection Routines
*/
-/* Oscillation Prevention/Reduction: recommended by rfc3448bis, on by default */
-static int do_osc_prev = true;
+#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
+static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state)
+{
+ static char *ccid3_state_names[] = {
+ [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];
+}
+#endif
+
+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;
+
+ ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
+ dccp_role(sk), sk, ccid3_tx_state_name(oldstate),
+ ccid3_tx_state_name(state));
+ WARN_ON(state == oldstate);
+ hctx->ccid3hctx_state = state;
+}
/*
* Compute the initial sending rate X_init in the manner of RFC 3390:
*
- * X_init = min(4 * MPS, max(2 * MPS, 4380 bytes)) / RTT
+ * X_init = min(4 * s, max(2 * s, 4380 bytes)) / RTT
*
+ * Note that RFC 3390 uses MSS, RFC 4342 refers to RFC 3390, and rfc3448bis
+ * (rev-02) clarifies the use of RFC 3390 with regard to the above formula.
* For consistency with other parts of the code, X_init is scaled by 2^6.
*/
static inline u64 rfc3390_initial_rate(struct sock *sk)
{
- const u32 mps = dccp_sk(sk)->dccps_mss_cache,
- w_init = clamp(4380U, 2 * mps, 4 * mps);
+ const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
+ const __u32 w_init = clamp_t(__u32, 4380U,
+ 2 * hctx->ccid3hctx_s, 4 * hctx->ccid3hctx_s);
- return scaled_div(w_init << 6, ccid3_hc_tx_sk(sk)->rtt);
+ return scaled_div(w_init << 6, hctx->ccid3hctx_rtt);
}
-/**
- * ccid3_update_send_interval - Calculate new t_ipi = s / X
- * This respects the granularity of X (64 * bytes/second) and enforces the
- * scaled minimum of s * 64 / t_mbi = `s' bytes/second as per RFC 3448/4342.
+/*
+ * Recalculate t_ipi and delta (should be called whenever X changes)
*/
static void ccid3_update_send_interval(struct ccid3_hc_tx_sock *hctx)
{
- if (unlikely(hctx->x <= hctx->s))
- hctx->x = hctx->s;
- hctx->t_ipi = scaled_div32(((u64)hctx->s) << 6, hctx->x);
+ /* Calculate new t_ipi = s / X_inst (X_inst is in 64 * bytes/second) */
+ hctx->ccid3hctx_t_ipi = scaled_div32(((u64)hctx->ccid3hctx_s) << 6,
+ hctx->ccid3hctx_x);
+
+ /* 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);
+
+ ccid3_pr_debug("t_ipi=%u, delta=%u, s=%u, X=%u\n",
+ hctx->ccid3hctx_t_ipi, hctx->ccid3hctx_delta,
+ hctx->ccid3hctx_s, (unsigned)(hctx->ccid3hctx_x >> 6));
+
}
static u32 ccid3_hc_tx_idle_rtt(struct ccid3_hc_tx_sock *hctx, ktime_t now)
{
- u32 delta = ktime_us_delta(now, hctx->t_last_win_count);
+ u32 delta = ktime_us_delta(now, hctx->ccid3hctx_t_last_win_count);
- return delta / hctx->rtt;
+ return delta / hctx->ccid3hctx_rtt;
}
/**
@@ -99,8 +133,8 @@ static u32 ccid3_hc_tx_idle_rtt(struct ccid3_hc_tx_sock *hctx, ktime_t now)
static void ccid3_hc_tx_update_x(struct sock *sk, ktime_t *stamp)
{
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
- u64 min_rate = 2 * hctx->x_recv;
- const u64 old_x = hctx->x;
+ __u64 min_rate = 2 * hctx->ccid3hctx_x_recv;
+ const __u64 old_x = hctx->ccid3hctx_x;
ktime_t now = stamp ? *stamp : ktime_get_real();
/*
@@ -111,44 +145,50 @@ static void ccid3_hc_tx_update_x(struct sock *sk, ktime_t *stamp)
*/
if (ccid3_hc_tx_idle_rtt(hctx, now) >= 2) {
min_rate = rfc3390_initial_rate(sk);
- min_rate = max(min_rate, 2 * hctx->x_recv);
+ min_rate = max(min_rate, 2 * hctx->ccid3hctx_x_recv);
}
- if (hctx->p > 0) {
+ if (hctx->ccid3hctx_p > 0) {
- hctx->x = min(((u64)hctx->x_calc) << 6, min_rate);
+ hctx->ccid3hctx_x = min(((__u64)hctx->ccid3hctx_x_calc) << 6,
+ min_rate);
+ hctx->ccid3hctx_x = max(hctx->ccid3hctx_x,
+ (((__u64)hctx->ccid3hctx_s) << 6) /
+ TFRC_T_MBI);
- } else if (ktime_us_delta(now, hctx->t_ld) - (s64)hctx->rtt >= 0) {
+ } else if (ktime_us_delta(now, hctx->ccid3hctx_t_ld)
+ - (s64)hctx->ccid3hctx_rtt >= 0) {
- hctx->x = min(2 * hctx->x, min_rate);
- hctx->x = max(hctx->x,
- scaled_div(((u64)hctx->s) << 6, hctx->rtt));
- hctx->t_ld = now;
+ hctx->ccid3hctx_x = min(2 * hctx->ccid3hctx_x, min_rate);
+ hctx->ccid3hctx_x = max(hctx->ccid3hctx_x,
+ scaled_div(((__u64)hctx->ccid3hctx_s) << 6,
+ hctx->ccid3hctx_rtt));
+ hctx->ccid3hctx_t_ld = now;
}
- if (hctx->x != old_x) {
+ if (hctx->ccid3hctx_x != old_x) {
ccid3_pr_debug("X_prev=%u, X_now=%u, X_calc=%u, "
"X_recv=%u\n", (unsigned)(old_x >> 6),
- (unsigned)(hctx->x >> 6), hctx->x_calc,
- (unsigned)(hctx->x_recv >> 6));
+ (unsigned)(hctx->ccid3hctx_x >> 6),
+ hctx->ccid3hctx_x_calc,
+ (unsigned)(hctx->ccid3hctx_x_recv >> 6));
ccid3_update_send_interval(hctx);
}
}
/*
- * ccid3_hc_tx_measure_packet_size - Measuring the packet size `s' (sec 4.1)
- * @new_len: DCCP payload size in bytes (not used by all methods)
+ * Track the mean packet size `s' (cf. RFC 4342, 5.3 and RFC 3448, 4.1)
+ * @len: DCCP packet payload size in bytes
*/
-static u32 ccid3_hc_tx_measure_packet_size(struct sock *sk, const u16 new_len)
+static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hctx, int len)
{
-#if defined(CONFIG_IP_DCCP_CCID3_MEASURE_S_AS_AVG)
- return tfrc_ewma(ccid3_hc_tx_sk(sk)->s, new_len, 9);
-#elif defined(CONFIG_IP_DCCP_CCID3_MEASURE_S_AS_MAX)
- return max(ccid3_hc_tx_sk(sk)->s, new_len);
-#else /* CONFIG_IP_DCCP_CCID3_MEASURE_S_AS_MPS */
- return dccp_sk(sk)->dccps_mss_cache;
-#endif
+ const u16 old_s = hctx->ccid3hctx_s;
+
+ hctx->ccid3hctx_s = tfrc_ewma(hctx->ccid3hctx_s, len, 9);
+
+ if (hctx->ccid3hctx_s != old_s)
+ ccid3_update_send_interval(hctx);
}
/*
@@ -158,13 +198,13 @@ static u32 ccid3_hc_tx_measure_packet_size(struct sock *sk, const u16 new_len)
static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hctx,
ktime_t now)
{
- u32 delta = ktime_us_delta(now, hctx->t_last_win_count),
- quarter_rtts = (4 * delta) / hctx->rtt;
+ u32 delta = ktime_us_delta(now, hctx->ccid3hctx_t_last_win_count),
+ quarter_rtts = (4 * delta) / hctx->ccid3hctx_rtt;
if (quarter_rtts > 0) {
- hctx->t_last_win_count = now;
- hctx->last_win_count += min(quarter_rtts, 5U);
- hctx->last_win_count &= 0xF; /* mod 16 */
+ hctx->ccid3hctx_t_last_win_count = now;
+ hctx->ccid3hctx_last_win_count += min(quarter_rtts, 5U);
+ hctx->ccid3hctx_last_win_count &= 0xF; /* mod 16 */
}
}
@@ -181,26 +221,25 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
goto restart_timer;
}
- ccid3_pr_debug("%s(%p) entry with%s feedback\n", dccp_role(sk), sk,
- hctx->feedback ? "" : "out");
+ ccid3_pr_debug("%s(%p, state=%s) - entry \n", dccp_role(sk), sk,
+ ccid3_tx_state_name(hctx->ccid3hctx_state));
- /* Ignore and do not restart after leaving the established state */
- if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
+ if (hctx->ccid3hctx_state == TFRC_SSTATE_FBACK)
+ ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);
+ else if (hctx->ccid3hctx_state != TFRC_SSTATE_NO_FBACK)
goto out;
- /* Reset feedback state to "no feedback received" */
- hctx->feedback = false;
-
/*
* 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 (hctx->t_rto == 0 || hctx->p == 0) {
+ if (hctx->ccid3hctx_t_rto == 0 || /* no feedback received yet */
+ hctx->ccid3hctx_p == 0) {
/* halve send rate directly */
- hctx->x /= 2;
+ hctx->ccid3hctx_x = max(hctx->ccid3hctx_x / 2,
+ (((__u64)hctx->ccid3hctx_s) << 6) /
+ TFRC_T_MBI);
ccid3_update_send_interval(hctx);
-
} else {
/*
* Modify the cached value of X_recv
@@ -212,41 +251,44 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
*
* Note that X_recv is scaled by 2^6 while X_calc is not
*/
- BUG_ON(hctx->p && !hctx->x_calc);
+ BUG_ON(hctx->ccid3hctx_p && !hctx->ccid3hctx_x_calc);
- if (hctx->x_calc > (hctx->x_recv >> 5))
- hctx->x_recv /= 2;
+ if (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));
else {
- hctx->x_recv = hctx->x_calc;
- hctx->x_recv <<= 4;
+ hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc;
+ hctx->ccid3hctx_x_recv <<= 4;
}
ccid3_hc_tx_update_x(sk, NULL);
}
ccid3_pr_debug("Reduced X to %llu/64 bytes/sec\n",
- (unsigned long long)hctx->x);
+ (unsigned long long)hctx->ccid3hctx_x);
/*
* Set new timeout for the nofeedback timer.
* See comments in packet_recv() regarding the value of t_RTO.
*/
- if (unlikely(hctx->t_rto == 0)) /* no feedback received yet */
+ if (unlikely(hctx->ccid3hctx_t_rto == 0)) /* no feedback yet */
t_nfb = TFRC_INITIAL_TIMEOUT;
else
- t_nfb = max(hctx->t_rto, 2 * hctx->t_ipi);
+ t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
restart_timer:
- sk_reset_timer(sk, &hctx->no_feedback_timer,
+ sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
jiffies + usecs_to_jiffies(t_nfb));
out:
bh_unlock_sock(sk);
sock_put(sk);
}
-/**
- * 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.
+/*
+ * 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)
{
@@ -263,14 +305,18 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
if (unlikely(skb->len == 0))
return -EBADMSG;
- if (hctx->s == 0) {
- sk_reset_timer(sk, &hctx->no_feedback_timer, (jiffies +
+ switch (hctx->ccid3hctx_state) {
+ case TFRC_SSTATE_NO_SENT:
+ sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
+ (jiffies +
usecs_to_jiffies(TFRC_INITIAL_TIMEOUT)));
- hctx->last_win_count = 0;
- hctx->t_last_win_count = now;
+ hctx->ccid3hctx_last_win_count = 0;
+ hctx->ccid3hctx_t_last_win_count = now;
/* Set t_0 for initial packet */
- hctx->t_nom = now;
+ hctx->ccid3hctx_t_nom = now;
+
+ hctx->ccid3hctx_s = skb->len;
/*
* Use initial RTT sample when available: recommended by erratum
@@ -279,9 +325,9 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
*/
if (dp->dccps_syn_rtt) {
ccid3_pr_debug("SYN RTT = %uus\n", dp->dccps_syn_rtt);
- hctx->rtt = dp->dccps_syn_rtt;
- hctx->x = rfc3390_initial_rate(sk);
- hctx->t_ld = now;
+ hctx->ccid3hctx_rtt = dp->dccps_syn_rtt;
+ hctx->ccid3hctx_x = rfc3390_initial_rate(sk);
+ hctx->ccid3hctx_t_ld = now;
} else {
/*
* Sender does not have RTT sample:
@@ -289,20 +335,17 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
* is needed in several parts (e.g. window counter);
* - set sending rate X_pps = 1pps as per RFC 3448, 4.2.
*/
- hctx->rtt = DCCP_FALLBACK_RTT;
- hctx->x = dp->dccps_mss_cache;
- hctx->x <<= 6;
+ hctx->ccid3hctx_rtt = DCCP_FALLBACK_RTT;
+ hctx->ccid3hctx_x = hctx->ccid3hctx_s;
+ hctx->ccid3hctx_x <<= 6;
}
-
- /* Compute t_ipi = s / X */
- hctx->s = ccid3_hc_tx_measure_packet_size(sk, skb->len);
ccid3_update_send_interval(hctx);
- /* Seed value for Oscillation Prevention (sec. 4.5) */
- hctx->r_sqmean = tfrc_scaled_sqrt(hctx->rtt);
-
- } else {
- delay = ktime_us_delta(hctx->t_nom, now);
+ ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);
+ break;
+ case TFRC_SSTATE_NO_FBACK:
+ case TFRC_SSTATE_FBACK:
+ delay = ktime_us_delta(hctx->ccid3hctx_t_nom, now);
ccid3_pr_debug("delay=%ld\n", (long)delay);
/*
* Scheduling of packet transmissions [RFC 3448, 4.6]
@@ -312,80 +355,99 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
* else
* // send the packet in (t_nom - t_now) milliseconds.
*/
- if (delay >= TFRC_T_DELTA)
- return (u32)delay / USEC_PER_MSEC;
+ if (delay - (s64)hctx->ccid3hctx_delta >= 1000)
+ return (u32)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;
}
/* prepare to send now (add options etc.) */
dp->dccps_hc_tx_insert_options = 1;
- DCCP_SKB_CB(skb)->dccpd_ccval = hctx->last_win_count;
+ DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count;
/* set the nominal send time for the next following packet */
- hctx->t_nom = ktime_add_us(hctx->t_nom, hctx->t_ipi);
- return CCID_PACKET_SEND_AT_ONCE;
+ hctx->ccid3hctx_t_nom = ktime_add_us(hctx->ccid3hctx_t_nom,
+ hctx->ccid3hctx_t_ipi);
+ return 0;
}
-static void ccid3_hc_tx_packet_sent(struct sock *sk, unsigned int len)
+static void ccid3_hc_tx_packet_sent(struct sock *sk, int more,
+ unsigned int len)
{
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
- /* Changes to s will become effective the next time X is computed */
- hctx->s = ccid3_hc_tx_measure_packet_size(sk, len);
+ ccid3_hc_tx_update_s(hctx, len);
- if (tfrc_tx_hist_add(&hctx->hist, dccp_sk(sk)->dccps_gss))
+ if (tfrc_tx_hist_add(&hctx->ccid3hctx_hist, dccp_sk(sk)->dccps_gss))
DCCP_CRIT("packet history - out of memory!");
}
static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
{
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
- struct tfrc_tx_hist_entry *acked;
+ struct ccid3_options_received *opt_recv;
ktime_t now;
unsigned long t_nfb;
- u32 r_sample;
+ u32 pinv, 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;
- /*
- * 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).
- */
- acked = tfrc_tx_hist_find_entry(hctx->hist, dccp_hdr_ack_seq(skb));
- if (acked == NULL)
+ /* ... and only in the established state */
+ if (hctx->ccid3hctx_state != TFRC_SSTATE_FBACK &&
+ hctx->ccid3hctx_state != TFRC_SSTATE_NO_FBACK)
+ return;
+
+ opt_recv = &hctx->ccid3hctx_options_received;
+ now = ktime_get_real();
+
+ /* Estimate RTT from history if ACK number is valid */
+ r_sample = tfrc_tx_hist_rtt(hctx->ccid3hctx_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;
- /* 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));
- hctx->rtt = tfrc_ewma(hctx->rtt, r_sample, 9);
+ /* 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 (which is scaled by 1e6) */
+ 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 = scaled_div(1, pinv);
+ /*
+ * Validate new RTT sample and update moving average
+ */
+ r_sample = dccp_sample_rtt(sk, r_sample);
+ hctx->ccid3hctx_rtt = tfrc_ewma(hctx->ccid3hctx_rtt, r_sample, 9);
/*
* Update allowed sending rate X as per draft rfc3448bis-00, 4.2/3
*/
- if (!hctx->feedback) {
- hctx->feedback = true;
+ if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
+ ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
- if (hctx->t_rto == 0) {
+ if (hctx->ccid3hctx_t_rto == 0) {
/*
* Initial feedback packet: Larger Initial Windows (4.2)
*/
- hctx->x = rfc3390_initial_rate(sk);
- hctx->t_ld = now;
+ hctx->ccid3hctx_x = rfc3390_initial_rate(sk);
+ hctx->ccid3hctx_t_ld = now;
ccid3_update_send_interval(hctx);
goto done_computing_x;
- } else if (hctx->p == 0) {
+ } else if (hctx->ccid3hctx_p == 0) {
/*
* First feedback after nofeedback timer expiry (4.3)
*/
@@ -394,52 +456,25 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
}
/* Update sending rate (step 4 of [RFC 3448, 4.3]) */
- if (hctx->p > 0)
- hctx->x_calc = tfrc_calc_x(hctx->s, hctx->rtt, hctx->p);
+ 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);
done_computing_x:
ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, "
"p=%u, X_calc=%u, X_recv=%u, X=%u\n",
- dccp_role(sk), sk, hctx->rtt, r_sample,
- hctx->s, hctx->p, hctx->x_calc,
- (unsigned)(hctx->x_recv >> 6),
- (unsigned)(hctx->x >> 6));
- /*
- * Oscillation Reduction (RFC 3448, 4.5) - modifying t_ipi according to
- * RTT changes, multiplying by X/X_inst = sqrt(R_sample)/R_sqmean. This
- * can be useful if few connections share a link, avoiding that buffer
- * fill levels (RTT) oscillate as a result of frequent adjustments to X.
- * A useful presentation with background information is in
- * Joerg Widmer, "Equation-Based Congestion Control",
- * MSc Thesis, University of Mannheim, Germany, 2000
- * (sec. 3.6.4), who calls this ISM ("Inter-packet Space Modulation").
- */
- if (do_osc_prev) {
- r_sample = tfrc_scaled_sqrt(r_sample);
- /*
- * The modulation can work in both ways: increase/decrease t_ipi
- * according to long-term increases/decreases of the RTT. The
- * former is a useful measure, since it works against queue
- * build-up. The latter temporarily increases the sending rate,
- * so that buffers fill up more quickly. This in turn causes
- * the RTT to increase, so that either later reduction becomes
- * necessary or the RTT stays at a very high level. Decreasing
- * t_ipi is therefore not supported.
- * Furthermore, during the initial slow-start phase the RTT
- * naturally increases, where using the algorithm would cause
- * delays. Hence it is disabled during the initial slow-start.
- */
- if (r_sample > hctx->r_sqmean && hctx->p > 0)
- hctx->t_ipi = div_u64((u64)hctx->t_ipi * (u64)r_sample,
- hctx->r_sqmean);
- hctx->t_ipi = min_t(u32, hctx->t_ipi, TFRC_T_MBI);
- /* update R_sqmean _after_ computing the modulation factor */
- hctx->r_sqmean = tfrc_ewma(hctx->r_sqmean, r_sample, 9);
- }
+ dccp_role(sk),
+ sk, hctx->ccid3hctx_rtt, 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->no_feedback_timer);
+ sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
/*
* As we have calculated new ipi, delta, t_nom it is possible
@@ -453,66 +488,95 @@ done_computing_x:
* This can help avoid triggering the nofeedback timer too
* often ('spinning') on LANs with small RTTs.
*/
- hctx->t_rto = max_t(u32, 4 * hctx->rtt, (CONFIG_IP_DCCP_CCID3_RTO *
- (USEC_PER_SEC / 1000)));
+ 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(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi)
*/
- t_nfb = max(hctx->t_rto, 2 * hctx->t_ipi);
+ 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(t_nfb), t_nfb);
+ dccp_role(sk),
+ sk, usecs_to_jiffies(t_nfb), t_nfb);
- sk_reset_timer(sk, &hctx->no_feedback_timer,
+ sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
jiffies + usecs_to_jiffies(t_nfb));
}
-static int ccid3_hc_tx_parse_options(struct sock *sk, u8 packet_type,
- u8 option, u8 *optval, u8 optlen)
+static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
+ unsigned char len, u16 idx,
+ unsigned char *value)
{
+ int rc = 0;
+ const struct dccp_sock *dp = dccp_sk(sk);
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
+ struct ccid3_options_received *opt_recv;
__be32 opt_val;
- switch (option) {
- case TFRC_OPT_RECEIVE_RATE:
- case TFRC_OPT_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;
- }
- opt_val = ntohl(get_unaligned((__be32 *)optval));
+ opt_recv = &hctx->ccid3hctx_options_received;
- if (option == TFRC_OPT_RECEIVE_RATE) {
- /* Receive Rate is kept in units of 64 bytes/second */
- hctx->x_recv = opt_val;
- hctx->x_recv <<= 6;
+ 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;
+ }
- ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n",
- dccp_role(sk), sk, opt_val);
+ switch (option) {
+ 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 {
- /* Update the fixpoint Loss Event Rate fraction */
- hctx->p = tfrc_invert_loss_event_rate(opt_val);
-
+ 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_val);
+ dccp_role(sk), sk,
+ opt_recv->ccid3or_loss_event_rate);
}
+ 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);
+ ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n",
+ dccp_role(sk), sk,
+ opt_recv->ccid3or_receive_rate);
+ }
+ break;
}
- return 0;
+
+ return rc;
}
static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk)
{
struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid);
- hctx->hist = NULL;
- setup_timer(&hctx->no_feedback_timer,
- ccid3_hc_tx_no_feedback_timer, (unsigned long)sk);
+ hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT;
+ hctx->ccid3hctx_hist = NULL;
+ setup_timer(&hctx->ccid3hctx_no_feedback_timer,
+ ccid3_hc_tx_no_feedback_timer, (unsigned long)sk);
+
return 0;
}
@@ -520,36 +584,42 @@ static void ccid3_hc_tx_exit(struct sock *sk)
{
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
- sk_stop_timer(sk, &hctx->no_feedback_timer);
- tfrc_tx_hist_purge(&hctx->hist);
+ ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM);
+ sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
+
+ tfrc_tx_hist_purge(&hctx->ccid3hctx_hist);
}
static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info)
{
- info->tcpi_rto = ccid3_hc_tx_sk(sk)->t_rto;
- info->tcpi_rtt = ccid3_hc_tx_sk(sk)->rtt;
+ struct ccid3_hc_tx_sock *hctx;
+
+ /* Listen socks doesn't have a private CCID block */
+ if (sk->sk_state == DCCP_LISTEN)
+ return;
+
+ hctx = ccid3_hc_tx_sk(sk);
+ info->tcpi_rto = hctx->ccid3hctx_t_rto;
+ info->tcpi_rtt = hctx->ccid3hctx_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 *hctx = ccid3_hc_tx_sk(sk);
- struct tfrc_tx_info tfrc;
+ const struct ccid3_hc_tx_sock *hctx;
const void *val;
+ /* Listen socks doesn't have a private CCID block */
+ if (sk->sk_state == DCCP_LISTEN)
+ return -EINVAL;
+
+ hctx = ccid3_hc_tx_sk(sk);
switch (optname) {
case DCCP_SOCKOPT_CCID_TX_INFO:
- if (len < sizeof(tfrc))
+ if (len < sizeof(hctx->ccid3hctx_tfrc))
return -EINVAL;
- tfrc.tfrctx_x = hctx->x;
- tfrc.tfrctx_x_recv = hctx->x_recv;
- tfrc.tfrctx_x_calc = hctx->x_calc;
- tfrc.tfrctx_rtt = hctx->rtt;
- tfrc.tfrctx_p = hctx->p;
- tfrc.tfrctx_rto = hctx->t_rto;
- tfrc.tfrctx_ipi = hctx->t_ipi;
- len = sizeof(tfrc);
- val = &tfrc;
+ len = sizeof(hctx->ccid3hctx_tfrc);
+ val = &hctx->ccid3hctx_tfrc;
break;
default:
return -ENOPROTOOPT;
@@ -564,82 +634,112 @@ static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len,
/*
* Receiver Half-Connection Routines
*/
+
+/* CCID3 feedback types */
+enum ccid3_fback_type {
+ CCID3_FBACK_NONE = 0,
+ CCID3_FBACK_INITIAL,
+ CCID3_FBACK_PERIODIC,
+ CCID3_FBACK_PARAM_CHANGE
+};
+
+#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[] = {
+ [TFRC_RSTATE_NO_DATA] = "NO_DATA",
+ [TFRC_RSTATE_DATA] = "DATA",
+ [TFRC_RSTATE_TERM] = "TERM",
+ };
+
+ return ccid3_rx_state_names[state];
+}
+#endif
+
+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;
+
+ ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
+ dccp_role(sk), sk, ccid3_rx_state_name(oldstate),
+ ccid3_rx_state_name(state));
+ WARN_ON(state == oldstate);
+ hcrx->ccid3hcrx_state = state;
+}
+
static void ccid3_hc_rx_send_feedback(struct sock *sk,
const struct sk_buff *skb,
enum ccid3_fback_type fbtype)
{
struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
+ struct dccp_sock *dp = dccp_sk(sk);
+ ktime_t now;
+ s64 delta = 0;
+
+ if (unlikely(hcrx->ccid3hcrx_state == TFRC_RSTATE_TERM))
+ return;
+
+ now = ktime_get_real();
switch (fbtype) {
case CCID3_FBACK_INITIAL:
- hcrx->x_recv = 0;
- hcrx->p_inverse = ~0U; /* see RFC 4342, 8.5 */
+ hcrx->ccid3hcrx_x_recv = 0;
+ hcrx->ccid3hcrx_pinv = ~0U; /* see RFC 4342, 8.5 */
break;
case CCID3_FBACK_PARAM_CHANGE:
- if (unlikely(hcrx->feedback == CCID3_FBACK_NONE)) {
- /*
- * rfc3448bis-06, 6.3.1: First packet(s) lost or marked
- * FIXME: in rfc3448bis the receiver returns X_recv=0
- * here as it normally would in the first feedback packet.
- * However this is not possible yet, since the code still
- * uses RFC 3448, i.e.
- * If (p > 0)
- * Calculate X_calc using the TCP throughput equation.
- * X = max(min(X_calc, 2*X_recv), s/t_mbi);
- * would bring X down to s/t_mbi. That is why we return
- * X_recv according to rfc3448bis-06 for the moment.
- */
- u32 s = tfrc_rx_hist_packet_size(&hcrx->hist),
- rtt = tfrc_rx_hist_rtt(&hcrx->hist);
-
- hcrx->x_recv = scaled_div32(s, 2 * rtt);
- break;
- }
/*
* When parameters change (new loss or p > p_prev), we do not
* have a reliable estimate for R_m of [RFC 3448, 6.2] and so
- * always check whether at least RTT time units were covered.
+ * need to reuse the previous value of X_recv. However, when
+ * X_recv was 0 (due to early loss), this would kill X down to
+ * s/t_mbi (i.e. one packet in 64 seconds).
+ * To avoid such drastic reduction, we approximate X_recv as
+ * the number of bytes since last feedback.
+ * This is a safe fallback, since X is bounded above by X_calc.
*/
- hcrx->x_recv = tfrc_rx_hist_x_recv(&hcrx->hist, hcrx->x_recv);
- break;
+ if (hcrx->ccid3hcrx_x_recv > 0)
+ break;
+ /* fall through */
case CCID3_FBACK_PERIODIC:
- /*
- * Step (2) of rfc3448bis-06, 6.2:
- * - if no data packets have been received, just restart timer
- * - if data packets have been received, re-compute X_recv
- */
- if (hcrx->hist.bytes_recvd == 0)
- goto prepare_for_next_time;
- hcrx->x_recv = tfrc_rx_hist_x_recv(&hcrx->hist, hcrx->x_recv);
+ delta = ktime_us_delta(now, hcrx->ccid3hcrx_tstamp_last_feedback);
+ if (delta <= 0)
+ DCCP_BUG("delta (%ld) <= 0", (long)delta);
+ else
+ hcrx->ccid3hcrx_x_recv =
+ scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta);
break;
default:
return;
}
- ccid3_pr_debug("X_recv=%u, 1/p=%u\n", hcrx->x_recv, hcrx->p_inverse);
+ ccid3_pr_debug("Interval %ldusec, X_recv=%u, 1/p=%u\n", (long)delta,
+ hcrx->ccid3hcrx_x_recv, hcrx->ccid3hcrx_pinv);
- dccp_sk(sk)->dccps_hc_rx_insert_options = 1;
- dccp_send_ack(sk);
+ hcrx->ccid3hcrx_tstamp_last_feedback = now;
+ hcrx->ccid3hcrx_last_counter = dccp_hdr(skb)->dccph_ccval;
+ hcrx->ccid3hcrx_bytes_recv = 0;
-prepare_for_next_time:
- tfrc_rx_hist_restart_byte_counter(&hcrx->hist);
- hcrx->last_counter = dccp_hdr(skb)->dccph_ccval;
- hcrx->feedback = fbtype;
+ dp->dccps_hc_rx_insert_options = 1;
+ dccp_send_ack(sk);
}
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);
+ const struct ccid3_hc_rx_sock *hcrx;
__be32 x_recv, pinv;
if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN))
return 0;
+ hcrx = ccid3_hc_rx_sk(sk);
+
if (dccp_packet_without_ack(skb))
return 0;
- x_recv = htonl(hcrx->x_recv);
- pinv = htonl(hcrx->p_inverse);
+ x_recv = htonl(hcrx->ccid3hcrx_x_recv);
+ pinv = htonl(hcrx->ccid3hcrx_pinv);
if (dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE,
&pinv, sizeof(pinv)) ||
@@ -662,95 +762,171 @@ static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb)
static u32 ccid3_first_li(struct sock *sk)
{
struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
- u32 s = tfrc_rx_hist_packet_size(&hcrx->hist),
- rtt = tfrc_rx_hist_rtt(&hcrx->hist), x_recv, p;
+ u32 x_recv, p, delta;
u64 fval;
- /*
- * rfc3448bis-06, 6.3.1: First data packet(s) are marked or lost. Set p
- * to give the equivalent of X_target = s/(2*R). Thus fval = 2 and so p
- * is about 20.64%. This yields an interval length of 4.84 (rounded up).
- */
- if (unlikely(hcrx->feedback == CCID3_FBACK_NONE))
- return 5;
+ if (hcrx->ccid3hcrx_rtt == 0) {
+ DCCP_WARN("No RTT estimate available, using fallback RTT\n");
+ hcrx->ccid3hcrx_rtt = DCCP_FALLBACK_RTT;
+ }
- x_recv = tfrc_rx_hist_x_recv(&hcrx->hist, hcrx->x_recv);
- if (x_recv == 0)
- goto failed;
+ delta = ktime_to_us(net_timedelta(hcrx->ccid3hcrx_tstamp_last_feedback));
+ 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 ~0U;
+ }
+ }
- fval = scaled_div32(scaled_div(s, rtt), x_recv);
+ fval = scaled_div(hcrx->ccid3hcrx_s, hcrx->ccid3hcrx_rtt);
+ fval = scaled_div32(fval, x_recv);
p = tfrc_calc_x_reverse_lookup(fval);
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 scaled_div(1, p);
-failed:
- return UINT_MAX;
+ return p == 0 ? ~0U : scaled_div(1, p);
}
static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
{
struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
+ enum ccid3_fback_type do_feedback = CCID3_FBACK_NONE;
const u64 ndp = dccp_sk(sk)->dccps_options_received.dccpor_ndp;
const bool is_data_packet = dccp_data_packet(skb);
+ if (unlikely(hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)) {
+ if (is_data_packet) {
+ const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4;
+ do_feedback = CCID3_FBACK_INITIAL;
+ ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA);
+ hcrx->ccid3hcrx_s = payload;
+ /*
+ * Not necessary to update ccid3hcrx_bytes_recv here,
+ * since X_recv = 0 for the first feedback packet (cf.
+ * RFC 3448, 6.3) -- gerrit
+ */
+ }
+ goto update_records;
+ }
+
+ if (tfrc_rx_hist_duplicate(&hcrx->ccid3hcrx_hist, skb))
+ return; /* done receiving */
+
+ if (is_data_packet) {
+ const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4;
+ /*
+ * Update moving-average of s and the sum of received payload bytes
+ */
+ hcrx->ccid3hcrx_s = tfrc_ewma(hcrx->ccid3hcrx_s, payload, 9);
+ hcrx->ccid3hcrx_bytes_recv += payload;
+ }
+
/*
* Perform loss detection and handle pending losses
*/
- if (tfrc_rx_congestion_event(&hcrx->hist, &hcrx->li_hist,
- skb, ndp, ccid3_first_li, sk))
- ccid3_hc_rx_send_feedback(sk, skb, CCID3_FBACK_PARAM_CHANGE);
+ if (tfrc_rx_handle_loss(&hcrx->ccid3hcrx_hist, &hcrx->ccid3hcrx_li_hist,
+ skb, ndp, ccid3_first_li, sk)) {
+ do_feedback = CCID3_FBACK_PARAM_CHANGE;
+ goto done_receiving;
+ }
+
+ if (tfrc_rx_hist_loss_pending(&hcrx->ccid3hcrx_hist))
+ return; /* done receiving */
+
/*
- * Feedback for first non-empty data packet (RFC 3448, 6.3)
+ * Handle data packets: RTT sampling and monitoring p
*/
- else if (unlikely(hcrx->feedback == CCID3_FBACK_NONE && is_data_packet))
- ccid3_hc_rx_send_feedback(sk, skb, CCID3_FBACK_INITIAL);
+ if (unlikely(!is_data_packet))
+ goto update_records;
+
+ if (!tfrc_lh_is_initialised(&hcrx->ccid3hcrx_li_hist)) {
+ const u32 sample = tfrc_rx_hist_sample_rtt(&hcrx->ccid3hcrx_hist, skb);
+ /*
+ * Empty loss history: no loss so far, hence p stays 0.
+ * Sample RTT values, since an RTT estimate is required for the
+ * computation of p when the first loss occurs; RFC 3448, 6.3.1.
+ */
+ if (sample != 0)
+ hcrx->ccid3hcrx_rtt = tfrc_ewma(hcrx->ccid3hcrx_rtt, sample, 9);
+
+ } else if (tfrc_lh_update_i_mean(&hcrx->ccid3hcrx_li_hist, skb)) {
+ /*
+ * Step (3) of [RFC 3448, 6.1]: Recompute I_mean and, if I_mean
+ * has decreased (resp. p has increased), send feedback now.
+ */
+ do_feedback = CCID3_FBACK_PARAM_CHANGE;
+ }
+
/*
* Check if the periodic once-per-RTT feedback is due; RFC 4342, 10.3
*/
- else if (!tfrc_rx_hist_loss_pending(&hcrx->hist) && is_data_packet &&
- SUB16(dccp_hdr(skb)->dccph_ccval, hcrx->last_counter) > 3)
- ccid3_hc_rx_send_feedback(sk, skb, CCID3_FBACK_PERIODIC);
+ if (SUB16(dccp_hdr(skb)->dccph_ccval, hcrx->ccid3hcrx_last_counter) > 3)
+ do_feedback = CCID3_FBACK_PERIODIC;
+
+update_records:
+ tfrc_rx_hist_add_packet(&hcrx->ccid3hcrx_hist, skb, ndp);
+
+done_receiving:
+ if (do_feedback)
+ ccid3_hc_rx_send_feedback(sk, skb, do_feedback);
}
static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk)
{
struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid);
- tfrc_lh_init(&hcrx->li_hist);
- return tfrc_rx_hist_init(&hcrx->hist, sk);
+ hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA;
+ tfrc_lh_init(&hcrx->ccid3hcrx_li_hist);
+ return tfrc_rx_hist_alloc(&hcrx->ccid3hcrx_hist);
}
static void ccid3_hc_rx_exit(struct sock *sk)
{
struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
- tfrc_rx_hist_purge(&hcrx->hist);
- tfrc_lh_cleanup(&hcrx->li_hist);
+ ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM);
+
+ tfrc_rx_hist_purge(&hcrx->ccid3hcrx_hist);
+ tfrc_lh_cleanup(&hcrx->ccid3hcrx_li_hist);
}
static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info)
{
+ const struct ccid3_hc_rx_sock *hcrx;
+
+ /* Listen socks doesn't have a private CCID block */
+ if (sk->sk_state == DCCP_LISTEN)
+ return;
+
+ hcrx = ccid3_hc_rx_sk(sk);
+ info->tcpi_ca_state = hcrx->ccid3hcrx_state;
info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
- info->tcpi_rcv_rtt = tfrc_rx_hist_rtt(&ccid3_hc_rx_sk(sk)->hist);
+ info->tcpi_rcv_rtt = hcrx->ccid3hcrx_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 *hcrx = ccid3_hc_rx_sk(sk);
+ const struct ccid3_hc_rx_sock *hcrx;
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;
+
+ hcrx = 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 = hcrx->x_recv;
- rx_info.tfrcrx_rtt = tfrc_rx_hist_rtt(&hcrx->hist);
- rx_info.tfrcrx_p = tfrc_invert_loss_event_rate(hcrx->p_inverse);
+ rx_info.tfrcrx_x_recv = hcrx->ccid3hcrx_x_recv;
+ rx_info.tfrcrx_rtt = hcrx->ccid3hcrx_rtt;
+ rx_info.tfrcrx_p = hcrx->ccid3hcrx_pinv == 0 ? ~0U :
+ scaled_div(1, hcrx->ccid3hcrx_pinv);
len = sizeof(rx_info);
val = &rx_info;
break;
@@ -786,9 +962,6 @@ static struct ccid_operations ccid3 = {
.ccid_hc_tx_getsockopt = ccid3_hc_tx_getsockopt,
};
-module_param(do_osc_prev, bool, 0644);
-MODULE_PARM_DESC(do_osc_prev, "Use Oscillation Prevention (RFC 3448, 4.5)");
-
#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
module_param(ccid3_debug, bool, 0644);
MODULE_PARM_DESC(ccid3_debug, "Enable debug messages");
@@ -796,19 +969,6 @@ MODULE_PARM_DESC(ccid3_debug, "Enable debug messages");
static __init int ccid3_module_init(void)
{
- struct timespec tp;
-
- /*
- * Without a fine-grained clock resolution, RTTs/X_recv are not sampled
- * correctly and feedback is sent either too early or too late.
- */
- hrtimer_get_res(CLOCK_MONOTONIC, &tp);
- if (tp.tv_sec || tp.tv_nsec > DCCP_TIME_RESOLUTION * NSEC_PER_USEC) {
- printk(KERN_ERR "%s: Timer too coarse (%ld usec), need %u-usec"
- " resolution - check your clocksource.\n", __func__,
- tp.tv_nsec/NSEC_PER_USEC, DCCP_TIME_RESOLUTION);
- return -ESOCKTNOSUPPORT;
- }
return ccid_register(&ccid3);
}
module_init(ccid3_module_init);