diff options
Diffstat (limited to 'net/dccp/ccids/ccid3.c')
-rw-r--r-- | net/dccp/ccids/ccid3.c | 762 |
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); |