diff options
Diffstat (limited to 'net/dccp/ccids')
| -rw-r--r-- | net/dccp/ccids/Kconfig | 55 | ||||
| -rw-r--r-- | net/dccp/ccids/ccid2.c | 794 | ||||
| -rw-r--r-- | net/dccp/ccids/ccid2.h | 121 | ||||
| -rw-r--r-- | net/dccp/ccids/ccid3.c | 866 | ||||
| -rw-r--r-- | net/dccp/ccids/ccid3.h | 148 | ||||
| -rw-r--r-- | net/dccp/ccids/lib/loss_interval.c | 184 | ||||
| -rw-r--r-- | net/dccp/ccids/lib/loss_interval.h | 69 | ||||
| -rw-r--r-- | net/dccp/ccids/lib/packet_history.c | 439 | ||||
| -rw-r--r-- | net/dccp/ccids/lib/packet_history.h | 142 | ||||
| -rw-r--r-- | net/dccp/ccids/lib/tfrc.c | 46 | ||||
| -rw-r--r-- | net/dccp/ccids/lib/tfrc.h | 73 | ||||
| -rw-r--r-- | net/dccp/ccids/lib/tfrc_equation.c | 702 |
12 files changed, 0 insertions, 3639 deletions
diff --git a/net/dccp/ccids/Kconfig b/net/dccp/ccids/Kconfig deleted file mode 100644 index e3d388c33d25..000000000000 --- a/net/dccp/ccids/Kconfig +++ /dev/null @@ -1,55 +0,0 @@ -# SPDX-License-Identifier: GPL-2.0-only -menu "DCCP CCIDs Configuration" - -config IP_DCCP_CCID2_DEBUG - bool "CCID-2 debugging messages" - help - Enable CCID-2 specific debugging messages. - - The debugging output can additionally be toggled by setting the - ccid2_debug parameter to 0 or 1. - - If in doubt, say N. - -config IP_DCCP_CCID3 - bool "CCID-3 (TCP-Friendly)" - default IP_DCCP = y || IP_DCCP = m - help - CCID-3 denotes TCP-Friendly Rate Control (TFRC), an equation-based - rate-controlled congestion control mechanism. TFRC is designed to - be reasonably fair when competing for bandwidth with TCP-like flows, - where a flow is "reasonably fair" if its sending rate is generally - within a factor of two of the sending rate of a TCP flow under the - same conditions. However, TFRC has a much lower variation of - throughput over time compared with TCP, which makes CCID-3 more - suitable than CCID-2 for applications such streaming media where a - relatively smooth sending rate is of importance. - - CCID-3 is further described in RFC 4342, - https://www.ietf.org/rfc/rfc4342.txt - - The TFRC congestion control algorithms were initially described in - RFC 5348. - - This text was extracted from RFC 4340 (sec. 10.2), - https://www.ietf.org/rfc/rfc4340.txt - - If in doubt, say N. - -config IP_DCCP_CCID3_DEBUG - bool "CCID-3 debugging messages" - depends on IP_DCCP_CCID3 - help - Enable CCID-3 specific debugging messages. - - The debugging output can additionally be toggled by setting the - ccid3_debug parameter to 0 or 1. - - If in doubt, say N. - -config IP_DCCP_TFRC_LIB - def_bool y if IP_DCCP_CCID3 - -config IP_DCCP_TFRC_DEBUG - def_bool y if IP_DCCP_CCID3_DEBUG -endmenu diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c deleted file mode 100644 index d6b30700af67..000000000000 --- a/net/dccp/ccids/ccid2.c +++ /dev/null @@ -1,794 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * Copyright (c) 2005, 2006 Andrea Bittau <a.bittau@cs.ucl.ac.uk> - * - * Changes to meet Linux coding standards, and DCCP infrastructure fixes. - * - * Copyright (c) 2006 Arnaldo Carvalho de Melo <acme@conectiva.com.br> - */ - -/* - * This implementation should follow RFC 4341 - */ -#include <linux/slab.h> -#include "../feat.h" -#include "ccid2.h" - - -#ifdef CONFIG_IP_DCCP_CCID2_DEBUG -static bool ccid2_debug; -#define ccid2_pr_debug(format, a...) DCCP_PR_DEBUG(ccid2_debug, format, ##a) -#else -#define ccid2_pr_debug(format, a...) -#endif - -static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hc) -{ - struct ccid2_seq *seqp; - int i; - - /* check if we have space to preserve the pointer to the buffer */ - if (hc->tx_seqbufc >= (sizeof(hc->tx_seqbuf) / - sizeof(struct ccid2_seq *))) - return -ENOMEM; - - /* allocate buffer and initialize linked list */ - seqp = kmalloc_array(CCID2_SEQBUF_LEN, sizeof(struct ccid2_seq), - gfp_any()); - if (seqp == NULL) - return -ENOMEM; - - for (i = 0; i < (CCID2_SEQBUF_LEN - 1); i++) { - seqp[i].ccid2s_next = &seqp[i + 1]; - seqp[i + 1].ccid2s_prev = &seqp[i]; - } - seqp[CCID2_SEQBUF_LEN - 1].ccid2s_next = seqp; - seqp->ccid2s_prev = &seqp[CCID2_SEQBUF_LEN - 1]; - - /* This is the first allocation. Initiate the head and tail. */ - if (hc->tx_seqbufc == 0) - hc->tx_seqh = hc->tx_seqt = seqp; - else { - /* link the existing list with the one we just created */ - hc->tx_seqh->ccid2s_next = seqp; - seqp->ccid2s_prev = hc->tx_seqh; - - hc->tx_seqt->ccid2s_prev = &seqp[CCID2_SEQBUF_LEN - 1]; - seqp[CCID2_SEQBUF_LEN - 1].ccid2s_next = hc->tx_seqt; - } - - /* store the original pointer to the buffer so we can free it */ - hc->tx_seqbuf[hc->tx_seqbufc] = seqp; - hc->tx_seqbufc++; - - return 0; -} - -static int ccid2_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) -{ - if (ccid2_cwnd_network_limited(ccid2_hc_tx_sk(sk))) - return CCID_PACKET_WILL_DEQUEUE_LATER; - return CCID_PACKET_SEND_AT_ONCE; -} - -static void ccid2_change_l_ack_ratio(struct sock *sk, u32 val) -{ - u32 max_ratio = DIV_ROUND_UP(ccid2_hc_tx_sk(sk)->tx_cwnd, 2); - - /* - * Ensure that Ack Ratio does not exceed ceil(cwnd/2), which is (2) from - * RFC 4341, 6.1.2. We ignore the statement that Ack Ratio 2 is always - * acceptable since this causes starvation/deadlock whenever cwnd < 2. - * The same problem arises when Ack Ratio is 0 (ie. Ack Ratio disabled). - */ - if (val == 0 || val > max_ratio) { - DCCP_WARN("Limiting Ack Ratio (%u) to %u\n", val, max_ratio); - val = max_ratio; - } - dccp_feat_signal_nn_change(sk, DCCPF_ACK_RATIO, - min_t(u32, val, DCCPF_ACK_RATIO_MAX)); -} - -static void ccid2_check_l_ack_ratio(struct sock *sk) -{ - struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); - - /* - * After a loss, idle period, application limited period, or RTO we - * need to check that the ack ratio is still less than the congestion - * window. Otherwise, we will send an entire congestion window of - * packets and got no response because we haven't sent ack ratio - * packets yet. - * If the ack ratio does need to be reduced, we reduce it to half of - * the congestion window (or 1 if that's zero) instead of to the - * congestion window. This prevents problems if one ack is lost. - */ - if (dccp_feat_nn_get(sk, DCCPF_ACK_RATIO) > hc->tx_cwnd) - ccid2_change_l_ack_ratio(sk, hc->tx_cwnd/2 ? : 1U); -} - -static void ccid2_change_l_seq_window(struct sock *sk, u64 val) -{ - dccp_feat_signal_nn_change(sk, DCCPF_SEQUENCE_WINDOW, - clamp_val(val, DCCPF_SEQ_WMIN, - DCCPF_SEQ_WMAX)); -} - -static void dccp_tasklet_schedule(struct sock *sk) -{ - struct tasklet_struct *t = &dccp_sk(sk)->dccps_xmitlet; - - if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) { - sock_hold(sk); - __tasklet_schedule(t); - } -} - -static void ccid2_hc_tx_rto_expire(struct timer_list *t) -{ - struct ccid2_hc_tx_sock *hc = from_timer(hc, t, tx_rtotimer); - struct sock *sk = hc->sk; - const bool sender_was_blocked = ccid2_cwnd_network_limited(hc); - - bh_lock_sock(sk); - if (sock_owned_by_user(sk)) { - sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + HZ / 5); - goto out; - } - - ccid2_pr_debug("RTO_EXPIRE\n"); - - if (sk->sk_state == DCCP_CLOSED) - goto out; - - /* back-off timer */ - hc->tx_rto <<= 1; - if (hc->tx_rto > DCCP_RTO_MAX) - hc->tx_rto = DCCP_RTO_MAX; - - /* adjust pipe, cwnd etc */ - hc->tx_ssthresh = hc->tx_cwnd / 2; - if (hc->tx_ssthresh < 2) - hc->tx_ssthresh = 2; - hc->tx_cwnd = 1; - hc->tx_pipe = 0; - - /* clear state about stuff we sent */ - hc->tx_seqt = hc->tx_seqh; - hc->tx_packets_acked = 0; - - /* clear ack ratio state. */ - hc->tx_rpseq = 0; - hc->tx_rpdupack = -1; - ccid2_change_l_ack_ratio(sk, 1); - - /* if we were blocked before, we may now send cwnd=1 packet */ - if (sender_was_blocked) - dccp_tasklet_schedule(sk); - /* restart backed-off timer */ - sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + hc->tx_rto); -out: - bh_unlock_sock(sk); - sock_put(sk); -} - -/* - * Congestion window validation (RFC 2861). - */ -static bool ccid2_do_cwv = true; -module_param(ccid2_do_cwv, bool, 0644); -MODULE_PARM_DESC(ccid2_do_cwv, "Perform RFC2861 Congestion Window Validation"); - -/** - * ccid2_update_used_window - Track how much of cwnd is actually used - * @hc: socket to update window - * @new_wnd: new window values to add into the filter - * - * This is done in addition to CWV. The sender needs to have an idea of how many - * packets may be in flight, to set the local Sequence Window value accordingly - * (RFC 4340, 7.5.2). The CWV mechanism is exploited to keep track of the - * maximum-used window. We use an EWMA low-pass filter to filter out noise. - */ -static void ccid2_update_used_window(struct ccid2_hc_tx_sock *hc, u32 new_wnd) -{ - hc->tx_expected_wnd = (3 * hc->tx_expected_wnd + new_wnd) / 4; -} - -/* This borrows the code of tcp_cwnd_application_limited() */ -static void ccid2_cwnd_application_limited(struct sock *sk, const u32 now) -{ - struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); - /* don't reduce cwnd below the initial window (IW) */ - u32 init_win = rfc3390_bytes_to_packets(dccp_sk(sk)->dccps_mss_cache), - win_used = max(hc->tx_cwnd_used, init_win); - - if (win_used < hc->tx_cwnd) { - hc->tx_ssthresh = max(hc->tx_ssthresh, - (hc->tx_cwnd >> 1) + (hc->tx_cwnd >> 2)); - hc->tx_cwnd = (hc->tx_cwnd + win_used) >> 1; - } - hc->tx_cwnd_used = 0; - hc->tx_cwnd_stamp = now; - - ccid2_check_l_ack_ratio(sk); -} - -/* This borrows the code of tcp_cwnd_restart() */ -static void ccid2_cwnd_restart(struct sock *sk, const u32 now) -{ - struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); - u32 cwnd = hc->tx_cwnd, restart_cwnd, - iwnd = rfc3390_bytes_to_packets(dccp_sk(sk)->dccps_mss_cache); - s32 delta = now - hc->tx_lsndtime; - - hc->tx_ssthresh = max(hc->tx_ssthresh, (cwnd >> 1) + (cwnd >> 2)); - - /* don't reduce cwnd below the initial window (IW) */ - restart_cwnd = min(cwnd, iwnd); - - while ((delta -= hc->tx_rto) >= 0 && cwnd > restart_cwnd) - cwnd >>= 1; - hc->tx_cwnd = max(cwnd, restart_cwnd); - hc->tx_cwnd_stamp = now; - hc->tx_cwnd_used = 0; - - ccid2_check_l_ack_ratio(sk); -} - -static void ccid2_hc_tx_packet_sent(struct sock *sk, unsigned int len) -{ - struct dccp_sock *dp = dccp_sk(sk); - struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); - const u32 now = ccid2_jiffies32; - struct ccid2_seq *next; - - /* slow-start after idle periods (RFC 2581, RFC 2861) */ - if (ccid2_do_cwv && !hc->tx_pipe && - (s32)(now - hc->tx_lsndtime) >= hc->tx_rto) - ccid2_cwnd_restart(sk, now); - - hc->tx_lsndtime = now; - hc->tx_pipe += 1; - - /* see whether cwnd was fully used (RFC 2861), update expected window */ - if (ccid2_cwnd_network_limited(hc)) { - ccid2_update_used_window(hc, hc->tx_cwnd); - hc->tx_cwnd_used = 0; - hc->tx_cwnd_stamp = now; - } else { - if (hc->tx_pipe > hc->tx_cwnd_used) - hc->tx_cwnd_used = hc->tx_pipe; - - ccid2_update_used_window(hc, hc->tx_cwnd_used); - - if (ccid2_do_cwv && (s32)(now - hc->tx_cwnd_stamp) >= hc->tx_rto) - ccid2_cwnd_application_limited(sk, now); - } - - hc->tx_seqh->ccid2s_seq = dp->dccps_gss; - hc->tx_seqh->ccid2s_acked = 0; - hc->tx_seqh->ccid2s_sent = now; - - next = hc->tx_seqh->ccid2s_next; - /* check if we need to alloc more space */ - if (next == hc->tx_seqt) { - if (ccid2_hc_tx_alloc_seq(hc)) { - DCCP_CRIT("packet history - out of memory!"); - /* FIXME: find a more graceful way to bail out */ - return; - } - next = hc->tx_seqh->ccid2s_next; - BUG_ON(next == hc->tx_seqt); - } - hc->tx_seqh = next; - - ccid2_pr_debug("cwnd=%d pipe=%d\n", hc->tx_cwnd, hc->tx_pipe); - - /* - * FIXME: The code below is broken and the variables have been removed - * from the socket struct. The `ackloss' variable was always set to 0, - * and with arsent there are several problems: - * (i) it doesn't just count the number of Acks, but all sent packets; - * (ii) it is expressed in # of packets, not # of windows, so the - * comparison below uses the wrong formula: Appendix A of RFC 4341 - * comes up with the number K = cwnd / (R^2 - R) of consecutive windows - * of data with no lost or marked Ack packets. If arsent were the # of - * consecutive Acks received without loss, then Ack Ratio needs to be - * decreased by 1 when - * arsent >= K * cwnd / R = cwnd^2 / (R^3 - R^2) - * where cwnd / R is the number of Acks received per window of data - * (cf. RFC 4341, App. A). The problems are that - * - arsent counts other packets as well; - * - the comparison uses a formula different from RFC 4341; - * - computing a cubic/quadratic equation each time is too complicated. - * Hence a different algorithm is needed. - */ -#if 0 - /* Ack Ratio. Need to maintain a concept of how many windows we sent */ - hc->tx_arsent++; - /* We had an ack loss in this window... */ - if (hc->tx_ackloss) { - if (hc->tx_arsent >= hc->tx_cwnd) { - hc->tx_arsent = 0; - hc->tx_ackloss = 0; - } - } else { - /* No acks lost up to now... */ - /* decrease ack ratio if enough packets were sent */ - if (dp->dccps_l_ack_ratio > 1) { - /* XXX don't calculate denominator each time */ - int denom = dp->dccps_l_ack_ratio * dp->dccps_l_ack_ratio - - dp->dccps_l_ack_ratio; - - denom = hc->tx_cwnd * hc->tx_cwnd / denom; - - if (hc->tx_arsent >= denom) { - ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio - 1); - hc->tx_arsent = 0; - } - } else { - /* we can't increase ack ratio further [1] */ - hc->tx_arsent = 0; /* or maybe set it to cwnd*/ - } - } -#endif - - sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + hc->tx_rto); - -#ifdef CONFIG_IP_DCCP_CCID2_DEBUG - do { - struct ccid2_seq *seqp = hc->tx_seqt; - - while (seqp != hc->tx_seqh) { - ccid2_pr_debug("out seq=%llu acked=%d time=%u\n", - (unsigned long long)seqp->ccid2s_seq, - seqp->ccid2s_acked, seqp->ccid2s_sent); - seqp = seqp->ccid2s_next; - } - } while (0); - ccid2_pr_debug("=========\n"); -#endif -} - -/** - * ccid2_rtt_estimator - Sample RTT and compute RTO using RFC2988 algorithm - * @sk: socket to perform estimator on - * @mrtt: measured RTT - * - * This code is almost identical with TCP's tcp_rtt_estimator(), since - * - it has a higher sampling frequency (recommended by RFC 1323), - * - the RTO does not collapse into RTT due to RTTVAR going towards zero, - * - it is simple (cf. more complex proposals such as Eifel timer or research - * which suggests that the gain should be set according to window size), - * - in tests it was found to work well with CCID2 [gerrit]. - */ -static void ccid2_rtt_estimator(struct sock *sk, const long mrtt) -{ - struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); - long m = mrtt ? : 1; - - if (hc->tx_srtt == 0) { - /* First measurement m */ - hc->tx_srtt = m << 3; - hc->tx_mdev = m << 1; - - hc->tx_mdev_max = max(hc->tx_mdev, tcp_rto_min(sk)); - hc->tx_rttvar = hc->tx_mdev_max; - - hc->tx_rtt_seq = dccp_sk(sk)->dccps_gss; - } else { - /* Update scaled SRTT as SRTT += 1/8 * (m - SRTT) */ - m -= (hc->tx_srtt >> 3); - hc->tx_srtt += m; - - /* Similarly, update scaled mdev with regard to |m| */ - if (m < 0) { - m = -m; - m -= (hc->tx_mdev >> 2); - /* - * This neutralises RTO increase when RTT < SRTT - mdev - * (see P. Sarolahti, A. Kuznetsov,"Congestion Control - * in Linux TCP", USENIX 2002, pp. 49-62). - */ - if (m > 0) - m >>= 3; - } else { - m -= (hc->tx_mdev >> 2); - } - hc->tx_mdev += m; - - if (hc->tx_mdev > hc->tx_mdev_max) { - hc->tx_mdev_max = hc->tx_mdev; - if (hc->tx_mdev_max > hc->tx_rttvar) - hc->tx_rttvar = hc->tx_mdev_max; - } - - /* - * Decay RTTVAR at most once per flight, exploiting that - * 1) pipe <= cwnd <= Sequence_Window = W (RFC 4340, 7.5.2) - * 2) AWL = GSS-W+1 <= GAR <= GSS (RFC 4340, 7.5.1) - * GAR is a useful bound for FlightSize = pipe. - * AWL is probably too low here, as it over-estimates pipe. - */ - if (after48(dccp_sk(sk)->dccps_gar, hc->tx_rtt_seq)) { - if (hc->tx_mdev_max < hc->tx_rttvar) - hc->tx_rttvar -= (hc->tx_rttvar - - hc->tx_mdev_max) >> 2; - hc->tx_rtt_seq = dccp_sk(sk)->dccps_gss; - hc->tx_mdev_max = tcp_rto_min(sk); - } - } - - /* - * Set RTO from SRTT and RTTVAR - * As in TCP, 4 * RTTVAR >= TCP_RTO_MIN, giving a minimum RTO of 200 ms. - * This agrees with RFC 4341, 5: - * "Because DCCP does not retransmit data, DCCP does not require - * TCP's recommended minimum timeout of one second". - */ - hc->tx_rto = (hc->tx_srtt >> 3) + hc->tx_rttvar; - - if (hc->tx_rto > DCCP_RTO_MAX) - hc->tx_rto = DCCP_RTO_MAX; -} - -static void ccid2_new_ack(struct sock *sk, struct ccid2_seq *seqp, - unsigned int *maxincr) -{ - struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); - struct dccp_sock *dp = dccp_sk(sk); - int r_seq_used = hc->tx_cwnd / dp->dccps_l_ack_ratio; - - if (hc->tx_cwnd < dp->dccps_l_seq_win && - r_seq_used < dp->dccps_r_seq_win) { - if (hc->tx_cwnd < hc->tx_ssthresh) { - if (*maxincr > 0 && ++hc->tx_packets_acked >= 2) { - hc->tx_cwnd += 1; - *maxincr -= 1; - hc->tx_packets_acked = 0; - } - } else if (++hc->tx_packets_acked >= hc->tx_cwnd) { - hc->tx_cwnd += 1; - hc->tx_packets_acked = 0; - } - } - - /* - * Adjust the local sequence window and the ack ratio to allow about - * 5 times the number of packets in the network (RFC 4340 7.5.2) - */ - if (r_seq_used * CCID2_WIN_CHANGE_FACTOR >= dp->dccps_r_seq_win) - ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio * 2); - else if (r_seq_used * CCID2_WIN_CHANGE_FACTOR < dp->dccps_r_seq_win/2) - ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio / 2 ? : 1U); - - if (hc->tx_cwnd * CCID2_WIN_CHANGE_FACTOR >= dp->dccps_l_seq_win) - ccid2_change_l_seq_window(sk, dp->dccps_l_seq_win * 2); - else if (hc->tx_cwnd * CCID2_WIN_CHANGE_FACTOR < dp->dccps_l_seq_win/2) - ccid2_change_l_seq_window(sk, dp->dccps_l_seq_win / 2); - - /* - * FIXME: RTT is sampled several times per acknowledgment (for each - * entry in the Ack Vector), instead of once per Ack (as in TCP SACK). - * This causes the RTT to be over-estimated, since the older entries - * in the Ack Vector have earlier sending times. - * The cleanest solution is to not use the ccid2s_sent field at all - * and instead use DCCP timestamps: requires changes in other places. - */ - ccid2_rtt_estimator(sk, ccid2_jiffies32 - seqp->ccid2s_sent); -} - -static void ccid2_congestion_event(struct sock *sk, struct ccid2_seq *seqp) -{ - struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); - - if ((s32)(seqp->ccid2s_sent - hc->tx_last_cong) < 0) { - ccid2_pr_debug("Multiple losses in an RTT---treating as one\n"); - return; - } - - hc->tx_last_cong = ccid2_jiffies32; - - hc->tx_cwnd = hc->tx_cwnd / 2 ? : 1U; - hc->tx_ssthresh = max(hc->tx_cwnd, 2U); - - ccid2_check_l_ack_ratio(sk); -} - -static int ccid2_hc_tx_parse_options(struct sock *sk, u8 packet_type, - u8 option, u8 *optval, u8 optlen) -{ - struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); - - switch (option) { - case DCCPO_ACK_VECTOR_0: - case DCCPO_ACK_VECTOR_1: - return dccp_ackvec_parsed_add(&hc->tx_av_chunks, optval, optlen, - option - DCCPO_ACK_VECTOR_0); - } - return 0; -} - -static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) -{ - struct dccp_sock *dp = dccp_sk(sk); - struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); - const bool sender_was_blocked = ccid2_cwnd_network_limited(hc); - struct dccp_ackvec_parsed *avp; - u64 ackno, seqno; - struct ccid2_seq *seqp; - int done = 0; - unsigned int maxincr = 0; - - /* check reverse path congestion */ - seqno = DCCP_SKB_CB(skb)->dccpd_seq; - - /* XXX this whole "algorithm" is broken. Need to fix it to keep track - * of the seqnos of the dupacks so that rpseq and rpdupack are correct - * -sorbo. - */ - /* need to bootstrap */ - if (hc->tx_rpdupack == -1) { - hc->tx_rpdupack = 0; - hc->tx_rpseq = seqno; - } else { - /* check if packet is consecutive */ - if (dccp_delta_seqno(hc->tx_rpseq, seqno) == 1) - hc->tx_rpseq = seqno; - /* it's a later packet */ - else if (after48(seqno, hc->tx_rpseq)) { - hc->tx_rpdupack++; - - /* check if we got enough dupacks */ - if (hc->tx_rpdupack >= NUMDUPACK) { - hc->tx_rpdupack = -1; /* XXX lame */ - hc->tx_rpseq = 0; -#ifdef __CCID2_COPES_GRACEFULLY_WITH_ACK_CONGESTION_CONTROL__ - /* - * FIXME: Ack Congestion Control is broken; in - * the current state instabilities occurred with - * Ack Ratios greater than 1; causing hang-ups - * and long RTO timeouts. This needs to be fixed - * before opening up dynamic changes. -- gerrit - */ - ccid2_change_l_ack_ratio(sk, 2 * dp->dccps_l_ack_ratio); -#endif - } - } - } - - /* check forward path congestion */ - if (dccp_packet_without_ack(skb)) - return; - - /* still didn't send out new data packets */ - if (hc->tx_seqh == hc->tx_seqt) - goto done; - - ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq; - if (after48(ackno, hc->tx_high_ack)) - hc->tx_high_ack = ackno; - - seqp = hc->tx_seqt; - while (before48(seqp->ccid2s_seq, ackno)) { - seqp = seqp->ccid2s_next; - if (seqp == hc->tx_seqh) { - seqp = hc->tx_seqh->ccid2s_prev; - break; - } - } - - /* - * In slow-start, cwnd can increase up to a maximum of Ack Ratio/2 - * packets per acknowledgement. Rounding up avoids that cwnd is not - * advanced when Ack Ratio is 1 and gives a slight edge otherwise. - */ - if (hc->tx_cwnd < hc->tx_ssthresh) - maxincr = DIV_ROUND_UP(dp->dccps_l_ack_ratio, 2); - - /* go through all ack vectors */ - list_for_each_entry(avp, &hc->tx_av_chunks, node) { - /* go through this ack vector */ - for (; avp->len--; avp->vec++) { - u64 ackno_end_rl = SUB48(ackno, - dccp_ackvec_runlen(avp->vec)); - - ccid2_pr_debug("ackvec %llu |%u,%u|\n", - (unsigned long long)ackno, - dccp_ackvec_state(avp->vec) >> 6, - dccp_ackvec_runlen(avp->vec)); - /* if the seqno we are analyzing is larger than the - * current ackno, then move towards the tail of our - * seqnos. - */ - while (after48(seqp->ccid2s_seq, ackno)) { - if (seqp == hc->tx_seqt) { - done = 1; - break; - } - seqp = seqp->ccid2s_prev; - } - if (done) - break; - - /* check all seqnos in the range of the vector - * run length - */ - while (between48(seqp->ccid2s_seq,ackno_end_rl,ackno)) { - const u8 state = dccp_ackvec_state(avp->vec); - - /* new packet received or marked */ - if (state != DCCPAV_NOT_RECEIVED && - !seqp->ccid2s_acked) { - if (state == DCCPAV_ECN_MARKED) - ccid2_congestion_event(sk, - seqp); - else - ccid2_new_ack(sk, seqp, - &maxincr); - - seqp->ccid2s_acked = 1; - ccid2_pr_debug("Got ack for %llu\n", - (unsigned long long)seqp->ccid2s_seq); - hc->tx_pipe--; - } - if (seqp == hc->tx_seqt) { - done = 1; - break; - } - seqp = seqp->ccid2s_prev; - } - if (done) - break; - - ackno = SUB48(ackno_end_rl, 1); - } - if (done) - break; - } - - /* The state about what is acked should be correct now - * Check for NUMDUPACK - */ - seqp = hc->tx_seqt; - while (before48(seqp->ccid2s_seq, hc->tx_high_ack)) { - seqp = seqp->ccid2s_next; - if (seqp == hc->tx_seqh) { - seqp = hc->tx_seqh->ccid2s_prev; - break; - } - } - done = 0; - while (1) { - if (seqp->ccid2s_acked) { - done++; - if (done == NUMDUPACK) - break; - } - if (seqp == hc->tx_seqt) - break; - seqp = seqp->ccid2s_prev; - } - - /* If there are at least 3 acknowledgements, anything unacknowledged - * below the last sequence number is considered lost - */ - if (done == NUMDUPACK) { - struct ccid2_seq *last_acked = seqp; - - /* check for lost packets */ - while (1) { - if (!seqp->ccid2s_acked) { - ccid2_pr_debug("Packet lost: %llu\n", - (unsigned long long)seqp->ccid2s_seq); - /* XXX need to traverse from tail -> head in - * order to detect multiple congestion events in - * one ack vector. - */ - ccid2_congestion_event(sk, seqp); - hc->tx_pipe--; - } - if (seqp == hc->tx_seqt) - break; - seqp = seqp->ccid2s_prev; - } - - hc->tx_seqt = last_acked; - } - - /* trim acked packets in tail */ - while (hc->tx_seqt != hc->tx_seqh) { - if (!hc->tx_seqt->ccid2s_acked) - break; - - hc->tx_seqt = hc->tx_seqt->ccid2s_next; - } - - /* restart RTO timer if not all outstanding data has been acked */ - if (hc->tx_pipe == 0) - sk_stop_timer(sk, &hc->tx_rtotimer); - else - sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + hc->tx_rto); -done: - /* check if incoming Acks allow pending packets to be sent */ - if (sender_was_blocked && !ccid2_cwnd_network_limited(hc)) - dccp_tasklet_schedule(sk); - dccp_ackvec_parsed_cleanup(&hc->tx_av_chunks); -} - -static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk) -{ - struct ccid2_hc_tx_sock *hc = ccid_priv(ccid); - struct dccp_sock *dp = dccp_sk(sk); - u32 max_ratio; - - /* RFC 4341, 5: initialise ssthresh to arbitrarily high (max) value */ - hc->tx_ssthresh = ~0U; - - /* Use larger initial windows (RFC 4341, section 5). */ - hc->tx_cwnd = rfc3390_bytes_to_packets(dp->dccps_mss_cache); - hc->tx_expected_wnd = hc->tx_cwnd; - - /* Make sure that Ack Ratio is enabled and within bounds. */ - max_ratio = DIV_ROUND_UP(hc->tx_cwnd, 2); - if (dp->dccps_l_ack_ratio == 0 || dp->dccps_l_ack_ratio > max_ratio) - dp->dccps_l_ack_ratio = max_ratio; - - /* XXX init ~ to window size... */ - if (ccid2_hc_tx_alloc_seq(hc)) - return -ENOMEM; - - hc->tx_rto = DCCP_TIMEOUT_INIT; - hc->tx_rpdupack = -1; - hc->tx_last_cong = hc->tx_lsndtime = hc->tx_cwnd_stamp = ccid2_jiffies32; - hc->tx_cwnd_used = 0; - hc->sk = sk; - timer_setup(&hc->tx_rtotimer, ccid2_hc_tx_rto_expire, 0); - INIT_LIST_HEAD(&hc->tx_av_chunks); - return 0; -} - -static void ccid2_hc_tx_exit(struct sock *sk) -{ - struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); - int i; - - sk_stop_timer(sk, &hc->tx_rtotimer); - - for (i = 0; i < hc->tx_seqbufc; i++) - kfree(hc->tx_seqbuf[i]); - hc->tx_seqbufc = 0; - dccp_ackvec_parsed_cleanup(&hc->tx_av_chunks); -} - -static void ccid2_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) -{ - struct ccid2_hc_rx_sock *hc = ccid2_hc_rx_sk(sk); - - if (!dccp_data_packet(skb)) - return; - - if (++hc->rx_num_data_pkts >= dccp_sk(sk)->dccps_r_ack_ratio) { - dccp_send_ack(sk); - hc->rx_num_data_pkts = 0; - } -} - -struct ccid_operations ccid2_ops = { - .ccid_id = DCCPC_CCID2, - .ccid_name = "TCP-like", - .ccid_hc_tx_obj_size = sizeof(struct ccid2_hc_tx_sock), - .ccid_hc_tx_init = ccid2_hc_tx_init, - .ccid_hc_tx_exit = ccid2_hc_tx_exit, - .ccid_hc_tx_send_packet = ccid2_hc_tx_send_packet, - .ccid_hc_tx_packet_sent = ccid2_hc_tx_packet_sent, - .ccid_hc_tx_parse_options = ccid2_hc_tx_parse_options, - .ccid_hc_tx_packet_recv = ccid2_hc_tx_packet_recv, - .ccid_hc_rx_obj_size = sizeof(struct ccid2_hc_rx_sock), - .ccid_hc_rx_packet_recv = ccid2_hc_rx_packet_recv, -}; - -#ifdef CONFIG_IP_DCCP_CCID2_DEBUG -module_param(ccid2_debug, bool, 0644); -MODULE_PARM_DESC(ccid2_debug, "Enable CCID-2 debug messages"); -#endif diff --git a/net/dccp/ccids/ccid2.h b/net/dccp/ccids/ccid2.h deleted file mode 100644 index 330c7b4ec001..000000000000 --- a/net/dccp/ccids/ccid2.h +++ /dev/null @@ -1,121 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -/* - * Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk> - */ -#ifndef _DCCP_CCID2_H_ -#define _DCCP_CCID2_H_ - -#include <linux/timer.h> -#include <linux/types.h> -#include "../ccid.h" -#include "../dccp.h" - -/* - * CCID-2 timestamping faces the same issues as TCP timestamping. - * Hence we reuse/share as much of the code as possible. - */ -#define ccid2_jiffies32 ((u32)jiffies) - -/* NUMDUPACK parameter from RFC 4341, p. 6 */ -#define NUMDUPACK 3 - -struct ccid2_seq { - u64 ccid2s_seq; - u32 ccid2s_sent; - int ccid2s_acked; - struct ccid2_seq *ccid2s_prev; - struct ccid2_seq *ccid2s_next; -}; - -#define CCID2_SEQBUF_LEN 1024 -#define CCID2_SEQBUF_MAX 128 - -/* - * Multiple of congestion window to keep the sequence window at - * (RFC 4340 7.5.2) - */ -#define CCID2_WIN_CHANGE_FACTOR 5 - -/** - * struct ccid2_hc_tx_sock - CCID2 TX half connection - * @tx_{cwnd,ssthresh,pipe}: as per RFC 4341, section 5 - * @tx_packets_acked: Ack counter for deriving cwnd growth (RFC 3465) - * @tx_srtt: smoothed RTT estimate, scaled by 2^3 - * @tx_mdev: smoothed RTT variation, scaled by 2^2 - * @tx_mdev_max: maximum of @mdev during one flight - * @tx_rttvar: moving average/maximum of @mdev_max - * @tx_rto: RTO value deriving from SRTT and RTTVAR (RFC 2988) - * @tx_rtt_seq: to decay RTTVAR at most once per flight - * @tx_cwnd_used: actually used cwnd, W_used of RFC 2861 - * @tx_expected_wnd: moving average of @tx_cwnd_used - * @tx_cwnd_stamp: to track idle periods in CWV - * @tx_lsndtime: last time (in jiffies) a data packet was sent - * @tx_rpseq: last consecutive seqno - * @tx_rpdupack: dupacks since rpseq - * @tx_av_chunks: list of Ack Vectors received on current skb - */ -struct ccid2_hc_tx_sock { - u32 tx_cwnd; - u32 tx_ssthresh; - u32 tx_pipe; - u32 tx_packets_acked; - struct ccid2_seq *tx_seqbuf[CCID2_SEQBUF_MAX]; - int tx_seqbufc; - struct ccid2_seq *tx_seqh; - struct ccid2_seq *tx_seqt; - - /* RTT measurement: variables/principles are the same as in TCP */ - u32 tx_srtt, - tx_mdev, - tx_mdev_max, - tx_rttvar, - tx_rto; - u64 tx_rtt_seq:48; - struct timer_list tx_rtotimer; - struct sock *sk; - - /* Congestion Window validation (optional, RFC 2861) */ - u32 tx_cwnd_used, - tx_expected_wnd, - tx_cwnd_stamp, - tx_lsndtime; - - u64 tx_rpseq; - int tx_rpdupack; - u32 tx_last_cong; - u64 tx_high_ack; - struct list_head tx_av_chunks; -}; - -static inline bool ccid2_cwnd_network_limited(struct ccid2_hc_tx_sock *hc) -{ - return hc->tx_pipe >= hc->tx_cwnd; -} - -/* - * Convert RFC 3390 larger initial window into an equivalent number of packets. - * This is based on the numbers specified in RFC 5681, 3.1. - */ -static inline u32 rfc3390_bytes_to_packets(const u32 smss) -{ - return smss <= 1095 ? 4 : (smss > 2190 ? 2 : 3); -} - -/** - * struct ccid2_hc_rx_sock - Receiving end of CCID-2 half-connection - * @rx_num_data_pkts: number of data packets received since last feedback - */ -struct ccid2_hc_rx_sock { - u32 rx_num_data_pkts; -}; - -static inline struct ccid2_hc_tx_sock *ccid2_hc_tx_sk(const struct sock *sk) -{ - return ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid); -} - -static inline struct ccid2_hc_rx_sock *ccid2_hc_rx_sk(const struct sock *sk) -{ - return ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid); -} -#endif /* _DCCP_CCID2_H_ */ diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c deleted file mode 100644 index f349d16dd8f6..000000000000 --- a/net/dccp/ccids/ccid3.c +++ /dev/null @@ -1,866 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * Copyright (c) 2007 The University of Aberdeen, Scotland, UK - * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand. - * Copyright (c) 2005-7 Ian McDonald <ian.mcdonald@jandi.co.nz> - * - * An implementation of the DCCP protocol - * - * This code has been developed by the University of Waikato WAND - * research group. For further information please see https://www.wand.net.nz/ - * - * This code also uses code from Lulea University, rereleased as GPL by its - * authors: - * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon - * - * Changes to meet Linux coding standards, to make it meet latest ccid3 draft - * and to make it work as a loadable module in the DCCP stack written by - * Arnaldo Carvalho de Melo <acme@conectiva.com.br>. - * - * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br> - */ -#include "../dccp.h" -#include "ccid3.h" - -#include <linux/unaligned.h> - -#ifdef CONFIG_IP_DCCP_CCID3_DEBUG -static bool ccid3_debug; -#define ccid3_pr_debug(format, a...) DCCP_PR_DEBUG(ccid3_debug, format, ##a) -#else -#define ccid3_pr_debug(format, a...) -#endif - -/* - * Transmitter Half-Connection Routines - */ -#ifdef CONFIG_IP_DCCP_CCID3_DEBUG -static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state) -{ - static const char *const ccid3_state_names[] = { - [TFRC_SSTATE_NO_SENT] = "NO_SENT", - [TFRC_SSTATE_NO_FBACK] = "NO_FBACK", - [TFRC_SSTATE_FBACK] = "FBACK", - }; - - 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 *hc = ccid3_hc_tx_sk(sk); - enum ccid3_hc_tx_states oldstate = hc->tx_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); - hc->tx_state = state; -} - -/* - * Compute the initial sending rate X_init in the manner of RFC 3390: - * - * 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 struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); - const __u32 w_init = clamp_t(__u32, 4380U, 2 * hc->tx_s, 4 * hc->tx_s); - - return scaled_div(w_init << 6, hc->tx_rtt); -} - -/** - * ccid3_update_send_interval - Calculate new t_ipi = s / X_inst - * @hc: socket to have the send interval updated - * - * This respects the granularity of X_inst (64 * bytes/second). - */ -static void ccid3_update_send_interval(struct ccid3_hc_tx_sock *hc) -{ - hc->tx_t_ipi = scaled_div32(((u64)hc->tx_s) << 6, hc->tx_x); - - DCCP_BUG_ON(hc->tx_t_ipi == 0); - ccid3_pr_debug("t_ipi=%u, s=%u, X=%u\n", hc->tx_t_ipi, - hc->tx_s, (unsigned int)(hc->tx_x >> 6)); -} - -static u32 ccid3_hc_tx_idle_rtt(struct ccid3_hc_tx_sock *hc, ktime_t now) -{ - u32 delta = ktime_us_delta(now, hc->tx_t_last_win_count); - - return delta / hc->tx_rtt; -} - -/** - * ccid3_hc_tx_update_x - Update allowed sending rate X - * @sk: socket to be updated - * @stamp: most recent time if available - can be left NULL. - * - * This function tracks draft rfc3448bis, check there for latest details. - * - * 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). - * - */ -static void ccid3_hc_tx_update_x(struct sock *sk, ktime_t *stamp) -{ - struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); - __u64 min_rate = 2 * hc->tx_x_recv; - const __u64 old_x = hc->tx_x; - ktime_t now = stamp ? *stamp : ktime_get_real(); - - /* - * Handle IDLE periods: do not reduce below RFC3390 initial sending rate - * when idling [RFC 4342, 5.1]. Definition of idling is from rfc3448bis: - * a sender is idle if it has not sent anything over a 2-RTT-period. - * For consistency with X and X_recv, min_rate is also scaled by 2^6. - */ - if (ccid3_hc_tx_idle_rtt(hc, now) >= 2) { - min_rate = rfc3390_initial_rate(sk); - min_rate = max(min_rate, 2 * hc->tx_x_recv); - } - - if (hc->tx_p > 0) { - - hc->tx_x = min(((__u64)hc->tx_x_calc) << 6, min_rate); - hc->tx_x = max(hc->tx_x, (((__u64)hc->tx_s) << 6) / TFRC_T_MBI); - - } else if (ktime_us_delta(now, hc->tx_t_ld) - (s64)hc->tx_rtt >= 0) { - - hc->tx_x = min(2 * hc->tx_x, min_rate); - hc->tx_x = max(hc->tx_x, - scaled_div(((__u64)hc->tx_s) << 6, hc->tx_rtt)); - hc->tx_t_ld = now; - } - - if (hc->tx_x != old_x) { - ccid3_pr_debug("X_prev=%u, X_now=%u, X_calc=%u, " - "X_recv=%u\n", (unsigned int)(old_x >> 6), - (unsigned int)(hc->tx_x >> 6), hc->tx_x_calc, - (unsigned int)(hc->tx_x_recv >> 6)); - - ccid3_update_send_interval(hc); - } -} - -/** - * ccid3_hc_tx_update_s - Track the mean packet size `s' - * @hc: socket to be updated - * @len: DCCP packet payload size in bytes - * - * cf. RFC 4342, 5.3 and RFC 3448, 4.1 - */ -static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hc, int len) -{ - const u16 old_s = hc->tx_s; - - hc->tx_s = tfrc_ewma(hc->tx_s, len, 9); - - if (hc->tx_s != old_s) - ccid3_update_send_interval(hc); -} - -/* - * Update Window Counter using the algorithm from [RFC 4342, 8.1]. - * As elsewhere, RTT > 0 is assumed by using dccp_sample_rtt(). - */ -static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hc, - ktime_t now) -{ - u32 delta = ktime_us_delta(now, hc->tx_t_last_win_count), - quarter_rtts = (4 * delta) / hc->tx_rtt; - - if (quarter_rtts > 0) { - hc->tx_t_last_win_count = now; - hc->tx_last_win_count += min(quarter_rtts, 5U); - hc->tx_last_win_count &= 0xF; /* mod 16 */ - } -} - -static void ccid3_hc_tx_no_feedback_timer(struct timer_list *t) -{ - struct ccid3_hc_tx_sock *hc = from_timer(hc, t, tx_no_feedback_timer); - struct sock *sk = hc->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 */ - goto restart_timer; - } - - ccid3_pr_debug("%s(%p, state=%s) - entry\n", dccp_role(sk), sk, - ccid3_tx_state_name(hc->tx_state)); - - /* Ignore and do not restart after leaving the established state */ - if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN)) - goto out; - - /* Reset feedback state to "no feedback received" */ - if (hc->tx_state == TFRC_SSTATE_FBACK) - ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); - - /* - * Determine new allowed sending rate X as per draft rfc3448bis-00, 4.4 - * RTO is 0 if and only if no feedback has been received yet. - */ - if (hc->tx_t_rto == 0 || hc->tx_p == 0) { - - /* halve send rate directly */ - hc->tx_x = max(hc->tx_x / 2, - (((__u64)hc->tx_s) << 6) / TFRC_T_MBI); - ccid3_update_send_interval(hc); - } else { - /* - * Modify the cached value of X_recv - * - * If (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 - */ - if (hc->tx_x_calc > (hc->tx_x_recv >> 5)) - hc->tx_x_recv = - max(hc->tx_x_recv / 2, - (((__u64)hc->tx_s) << 6) / (2*TFRC_T_MBI)); - else { - hc->tx_x_recv = hc->tx_x_calc; - hc->tx_x_recv <<= 4; - } - ccid3_hc_tx_update_x(sk, NULL); - } - ccid3_pr_debug("Reduced X to %llu/64 bytes/sec\n", - (unsigned long long)hc->tx_x); - - /* - * Set new timeout for the nofeedback timer. - * See comments in packet_recv() regarding the value of t_RTO. - */ - if (unlikely(hc->tx_t_rto == 0)) /* no feedback received yet */ - t_nfb = TFRC_INITIAL_TIMEOUT; - else - t_nfb = max(hc->tx_t_rto, 2 * hc->tx_t_ipi); - -restart_timer: - sk_reset_timer(sk, &hc->tx_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 - * @sk: socket to send packet from - * @skb: next packet candidate to send on @sk - * - * This function uses the convention of ccid_packet_dequeue_eval() and - * returns a millisecond-delay value between 0 and t_mbi = 64000 msec. - */ -static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) -{ - struct dccp_sock *dp = dccp_sk(sk); - struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); - ktime_t now = ktime_get_real(); - s64 delay; - - /* - * 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(skb->len == 0)) - return -EBADMSG; - - if (hc->tx_state == TFRC_SSTATE_NO_SENT) { - sk_reset_timer(sk, &hc->tx_no_feedback_timer, (jiffies + - usecs_to_jiffies(TFRC_INITIAL_TIMEOUT))); - hc->tx_last_win_count = 0; - hc->tx_t_last_win_count = now; - - /* Set t_0 for initial packet */ - hc->tx_t_nom = now; - - hc->tx_s = skb->len; - - /* - * Use initial RTT sample when available: recommended by erratum - * to RFC 4342. This implements the initialisation procedure of - * draft rfc3448bis, section 4.2. Remember, X is scaled by 2^6. - */ - if (dp->dccps_syn_rtt) { - ccid3_pr_debug("SYN RTT = %uus\n", dp->dccps_syn_rtt); - hc->tx_rtt = dp->dccps_syn_rtt; - hc->tx_x = rfc3390_initial_rate(sk); - hc->tx_t_ld = now; - } else { - /* - * Sender does not have RTT sample: - * - set fallback RTT (RFC 4340, 3.4) since a RTT value - * is needed in several parts (e.g. window counter); - * - set sending rate X_pps = 1pps as per RFC 3448, 4.2. - */ - hc->tx_rtt = DCCP_FALLBACK_RTT; - hc->tx_x = hc->tx_s; - hc->tx_x <<= 6; - } - ccid3_update_send_interval(hc); - - ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); - - } else { - delay = ktime_us_delta(hc->tx_t_nom, now); - ccid3_pr_debug("delay=%ld\n", (long)delay); - /* - * Scheduling of packet transmissions (RFC 5348, 8.3) - * - * if (t_now > t_nom - delta) - * // send the packet now - * else - * // send the packet in (t_nom - t_now) milliseconds. - */ - if (delay >= TFRC_T_DELTA) - return (u32)delay / USEC_PER_MSEC; - - ccid3_hc_tx_update_win_count(hc, now); - } - - /* prepare to send now (add options etc.) */ - dp->dccps_hc_tx_insert_options = 1; - DCCP_SKB_CB(skb)->dccpd_ccval = hc->tx_last_win_count; - - /* set the nominal send time for the next following packet */ - hc->tx_t_nom = ktime_add_us(hc->tx_t_nom, hc->tx_t_ipi); - return CCID_PACKET_SEND_AT_ONCE; -} - -static void ccid3_hc_tx_packet_sent(struct sock *sk, unsigned int len) -{ - struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); - - ccid3_hc_tx_update_s(hc, len); - - if (tfrc_tx_hist_add(&hc->tx_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 *hc = ccid3_hc_tx_sk(sk); - struct tfrc_tx_hist_entry *acked; - ktime_t now; - unsigned long t_nfb; - u32 r_sample; - - /* we are only interested in ACKs */ - if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK || - DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK)) - return; - /* - * 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(hc->tx_hist, dccp_hdr_ack_seq(skb)); - if (acked == NULL) - return; - /* For the sake of RTT sampling, ignore/remove all older entries */ - tfrc_tx_hist_purge(&acked->next); - - /* Update the moving average for the RTT estimate (RFC 3448, 4.3) */ - now = ktime_get_real(); - r_sample = dccp_sample_rtt(sk, ktime_us_delta(now, acked->stamp)); - hc->tx_rtt = tfrc_ewma(hc->tx_rtt, r_sample, 9); - - /* - * Update allowed sending rate X as per draft rfc3448bis-00, 4.2/3 - */ - if (hc->tx_state == TFRC_SSTATE_NO_FBACK) { - ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK); - - if (hc->tx_t_rto == 0) { - /* - * Initial feedback packet: Larger Initial Windows (4.2) - */ - hc->tx_x = rfc3390_initial_rate(sk); - hc->tx_t_ld = now; - - ccid3_update_send_interval(hc); - - goto done_computing_x; - } else if (hc->tx_p == 0) { - /* - * First feedback after nofeedback timer expiry (4.3) - */ - goto done_computing_x; - } - } - - /* Update sending rate (step 4 of [RFC 3448, 4.3]) */ - if (hc->tx_p > 0) - hc->tx_x_calc = tfrc_calc_x(hc->tx_s, hc->tx_rtt, hc->tx_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, hc->tx_rtt, r_sample, - hc->tx_s, hc->tx_p, hc->tx_x_calc, - (unsigned int)(hc->tx_x_recv >> 6), - (unsigned int)(hc->tx_x >> 6)); - - /* unschedule no feedback timer */ - sk_stop_timer(sk, &hc->tx_no_feedback_timer); - - /* - * 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. In order to control - * rate halving on networks with very low RTTs (<= 1 ms), use per-route - * tunable RTAX_RTO_MIN value as the lower bound. - */ - hc->tx_t_rto = max_t(u32, 4 * hc->tx_rtt, - USEC_PER_SEC/HZ * tcp_rto_min(sk)); - /* - * Schedule no feedback timer to expire in - * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi) - */ - t_nfb = max(hc->tx_t_rto, 2 * hc->tx_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); - - sk_reset_timer(sk, &hc->tx_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) -{ - struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); - __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)); - - if (option == TFRC_OPT_RECEIVE_RATE) { - /* Receive Rate is kept in units of 64 bytes/second */ - hc->tx_x_recv = opt_val; - hc->tx_x_recv <<= 6; - - ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n", - dccp_role(sk), sk, opt_val); - } else { - /* Update the fixpoint Loss Event Rate fraction */ - hc->tx_p = tfrc_invert_loss_event_rate(opt_val); - - ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n", - dccp_role(sk), sk, opt_val); - } - } - return 0; -} - -static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk) -{ - struct ccid3_hc_tx_sock *hc = ccid_priv(ccid); - - hc->tx_state = TFRC_SSTATE_NO_SENT; - hc->tx_hist = NULL; - hc->sk = sk; - timer_setup(&hc->tx_no_feedback_timer, - ccid3_hc_tx_no_feedback_timer, 0); - return 0; -} - -static void ccid3_hc_tx_exit(struct sock *sk) -{ - struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); - - sk_stop_timer(sk, &hc->tx_no_feedback_timer); - tfrc_tx_hist_purge(&hc->tx_hist); -} - -static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info) -{ - info->tcpi_rto = ccid3_hc_tx_sk(sk)->tx_t_rto; - info->tcpi_rtt = ccid3_hc_tx_sk(sk)->tx_rtt; -} - -static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len, - u32 __user *optval, int __user *optlen) -{ - const struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); - struct tfrc_tx_info tfrc; - const void *val; - - switch (optname) { - case DCCP_SOCKOPT_CCID_TX_INFO: - if (len < sizeof(tfrc)) - return -EINVAL; - memset(&tfrc, 0, sizeof(tfrc)); - tfrc.tfrctx_x = hc->tx_x; - tfrc.tfrctx_x_recv = hc->tx_x_recv; - tfrc.tfrctx_x_calc = hc->tx_x_calc; - tfrc.tfrctx_rtt = hc->tx_rtt; - tfrc.tfrctx_p = hc->tx_p; - tfrc.tfrctx_rto = hc->tx_t_rto; - tfrc.tfrctx_ipi = hc->tx_t_ipi; - len = sizeof(tfrc); - val = &tfrc; - break; - default: - return -ENOPROTOOPT; - } - - if (put_user(len, optlen) || copy_to_user(optval, val, len)) - return -EFAULT; - - return 0; -} - -/* - * 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 const char *const ccid3_rx_state_names[] = { - [TFRC_RSTATE_NO_DATA] = "NO_DATA", - [TFRC_RSTATE_DATA] = "DATA", - }; - - 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 *hc = ccid3_hc_rx_sk(sk); - enum ccid3_hc_rx_states oldstate = hc->rx_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); - hc->rx_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 *hc = ccid3_hc_rx_sk(sk); - struct dccp_sock *dp = dccp_sk(sk); - ktime_t now = ktime_get(); - s64 delta = 0; - - switch (fbtype) { - case CCID3_FBACK_INITIAL: - hc->rx_x_recv = 0; - hc->rx_pinv = ~0U; /* see RFC 4342, 8.5 */ - break; - case CCID3_FBACK_PARAM_CHANGE: - /* - * 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 - * 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. - */ - if (hc->rx_x_recv > 0) - break; - fallthrough; - case CCID3_FBACK_PERIODIC: - delta = ktime_us_delta(now, hc->rx_tstamp_last_feedback); - if (delta <= 0) - delta = 1; - hc->rx_x_recv = scaled_div32(hc->rx_bytes_recv, delta); - break; - default: - return; - } - - ccid3_pr_debug("Interval %lldusec, X_recv=%u, 1/p=%u\n", delta, - hc->rx_x_recv, hc->rx_pinv); - - hc->rx_tstamp_last_feedback = now; - hc->rx_last_counter = dccp_hdr(skb)->dccph_ccval; - hc->rx_bytes_recv = 0; - - 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 *hc = ccid3_hc_rx_sk(sk); - __be32 x_recv, pinv; - - if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN)) - return 0; - - if (dccp_packet_without_ack(skb)) - return 0; - - x_recv = htonl(hc->rx_x_recv); - pinv = htonl(hc->rx_pinv); - - if (dccp_insert_option(skb, TFRC_OPT_LOSS_EVENT_RATE, - &pinv, sizeof(pinv)) || - dccp_insert_option(skb, TFRC_OPT_RECEIVE_RATE, - &x_recv, sizeof(x_recv))) - return -1; - - return 0; -} - -/** - * ccid3_first_li - Implements [RFC 5348, 6.3.1] - * @sk: socket to calculate loss interval for - * - * 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 (scaled). - */ -static u32 ccid3_first_li(struct sock *sk) -{ - struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); - u32 x_recv, p; - s64 delta; - u64 fval; - - if (hc->rx_rtt == 0) { - DCCP_WARN("No RTT estimate available, using fallback RTT\n"); - hc->rx_rtt = DCCP_FALLBACK_RTT; - } - - delta = ktime_us_delta(ktime_get(), hc->rx_tstamp_last_feedback); - if (delta <= 0) - delta = 1; - x_recv = scaled_div32(hc->rx_bytes_recv, delta); - if (x_recv == 0) { /* would also trigger divide-by-zero */ - DCCP_WARN("X_recv==0\n"); - if (hc->rx_x_recv == 0) { - DCCP_BUG("stored value of X_recv is zero"); - return ~0U; - } - x_recv = hc->rx_x_recv; - } - - fval = scaled_div(hc->rx_s, hc->rx_rtt); - 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); - - 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 *hc = 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(hc->rx_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); - hc->rx_s = payload; - /* - * Not necessary to update rx_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(&hc->rx_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 - */ - hc->rx_s = tfrc_ewma(hc->rx_s, payload, 9); - hc->rx_bytes_recv += payload; - } - - /* - * Perform loss detection and handle pending losses - */ - if (tfrc_rx_handle_loss(&hc->rx_hist, &hc->rx_li_hist, - skb, ndp, ccid3_first_li, sk)) { - do_feedback = CCID3_FBACK_PARAM_CHANGE; - goto done_receiving; - } - - if (tfrc_rx_hist_loss_pending(&hc->rx_hist)) - return; /* done receiving */ - - /* - * Handle data packets: RTT sampling and monitoring p - */ - if (unlikely(!is_data_packet)) - goto update_records; - - if (!tfrc_lh_is_initialised(&hc->rx_li_hist)) { - const u32 sample = tfrc_rx_hist_sample_rtt(&hc->rx_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) - hc->rx_rtt = tfrc_ewma(hc->rx_rtt, sample, 9); - - } else if (tfrc_lh_update_i_mean(&hc->rx_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 - */ - if (SUB16(dccp_hdr(skb)->dccph_ccval, hc->rx_last_counter) > 3) - do_feedback = CCID3_FBACK_PERIODIC; - -update_records: - tfrc_rx_hist_add_packet(&hc->rx_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 *hc = ccid_priv(ccid); - - hc->rx_state = TFRC_RSTATE_NO_DATA; - tfrc_lh_init(&hc->rx_li_hist); - return tfrc_rx_hist_alloc(&hc->rx_hist); -} - -static void ccid3_hc_rx_exit(struct sock *sk) -{ - struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); - - tfrc_rx_hist_purge(&hc->rx_hist); - tfrc_lh_cleanup(&hc->rx_li_hist); -} - -static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info) -{ - info->tcpi_ca_state = ccid3_hc_rx_sk(sk)->rx_state; - info->tcpi_options |= TCPI_OPT_TIMESTAMPS; - info->tcpi_rcv_rtt = ccid3_hc_rx_sk(sk)->rx_rtt; -} - -static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len, - u32 __user *optval, int __user *optlen) -{ - const struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); - struct tfrc_rx_info rx_info; - const void *val; - - switch (optname) { - case DCCP_SOCKOPT_CCID_RX_INFO: - if (len < sizeof(rx_info)) - return -EINVAL; - rx_info.tfrcrx_x_recv = hc->rx_x_recv; - rx_info.tfrcrx_rtt = hc->rx_rtt; - rx_info.tfrcrx_p = tfrc_invert_loss_event_rate(hc->rx_pinv); - len = sizeof(rx_info); - val = &rx_info; - break; - default: - return -ENOPROTOOPT; - } - - if (put_user(len, optlen) || copy_to_user(optval, val, len)) - return -EFAULT; - - return 0; -} - -struct ccid_operations ccid3_ops = { - .ccid_id = DCCPC_CCID3, - .ccid_name = "TCP-Friendly Rate Control", - .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_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_packet_recv = ccid3_hc_rx_packet_recv, - .ccid_hc_rx_get_info = ccid3_hc_rx_get_info, - .ccid_hc_tx_get_info = ccid3_hc_tx_get_info, - .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, bool, 0644); -MODULE_PARM_DESC(ccid3_debug, "Enable CCID-3 debug messages"); -#endif diff --git a/net/dccp/ccids/ccid3.h b/net/dccp/ccids/ccid3.h deleted file mode 100644 index 02e0fc9f6334..000000000000 --- a/net/dccp/ccids/ccid3.h +++ /dev/null @@ -1,148 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -/* - * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand. - * Copyright (c) 2007 The University of Aberdeen, Scotland, UK - * - * An implementation of the DCCP protocol - * - * This code has been developed by the University of Waikato WAND - * research group. For further information please see https://www.wand.net.nz/ - * or e-mail Ian McDonald - ian.mcdonald@jandi.co.nz - * - * This code also uses code from Lulea University, rereleased as GPL by its - * authors: - * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon - * - * Changes to meet Linux coding standards, to make it meet latest ccid3 draft - * and to make it work as a loadable module in the DCCP stack written by - * Arnaldo Carvalho de Melo <acme@conectiva.com.br>. - * - * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br> - */ -#ifndef _DCCP_CCID3_H_ -#define _DCCP_CCID3_H_ - -#include <linux/ktime.h> -#include <linux/list.h> -#include <linux/types.h> -#include <linux/tfrc.h> -#include "lib/tfrc.h" -#include "../ccid.h" - -/* Two seconds as per RFC 5348, 4.2 */ -#define TFRC_INITIAL_TIMEOUT (2 * USEC_PER_SEC) - -/* Parameter t_mbi from [RFC 3448, 4.3]: backoff interval in seconds */ -#define TFRC_T_MBI 64 - -/* - * The t_delta parameter (RFC 5348, 8.3): delays of less than %USEC_PER_MSEC are - * rounded down to 0, since sk_reset_timer() here uses millisecond granularity. - * Hence we can use a constant t_delta = %USEC_PER_MSEC when HZ >= 500. A coarse - * resolution of HZ < 500 means that the error is below one timer tick (t_gran) - * when using the constant t_delta = t_gran / 2 = %USEC_PER_SEC / (2 * HZ). - */ -#if (HZ >= 500) -# define TFRC_T_DELTA USEC_PER_MSEC -#else -# define TFRC_T_DELTA (USEC_PER_SEC / (2 * HZ)) -#endif - -enum ccid3_options { - TFRC_OPT_LOSS_EVENT_RATE = 192, - TFRC_OPT_LOSS_INTERVALS = 193, - TFRC_OPT_RECEIVE_RATE = 194, -}; - -/* TFRC sender states */ -enum ccid3_hc_tx_states { - TFRC_SSTATE_NO_SENT = 1, - TFRC_SSTATE_NO_FBACK, - TFRC_SSTATE_FBACK, -}; - -/** - * struct ccid3_hc_tx_sock - CCID3 sender half-connection socket - * @tx_x: Current sending rate in 64 * bytes per second - * @tx_x_recv: Receive rate in 64 * bytes per second - * @tx_x_calc: Calculated rate in bytes per second - * @tx_rtt: Estimate of current round trip time in usecs - * @tx_p: Current loss event rate (0-1) scaled by 1000000 - * @tx_s: Packet size in bytes - * @tx_t_rto: Nofeedback Timer setting in usecs - * @tx_t_ipi: Interpacket (send) interval (RFC 3448, 4.6) in usecs - * @tx_state: Sender state, one of %ccid3_hc_tx_states - * @tx_last_win_count: Last window counter sent - * @tx_t_last_win_count: Timestamp of earliest packet - * with last_win_count value sent - * @tx_no_feedback_timer: Handle to no feedback timer - * @tx_t_ld: Time last doubled during slow start - * @tx_t_nom: Nominal send time of next packet - * @tx_hist: Packet history - */ -struct ccid3_hc_tx_sock { - u64 tx_x; - u64 tx_x_recv; - u32 tx_x_calc; - u32 tx_rtt; - u32 tx_p; - u32 tx_t_rto; - u32 tx_t_ipi; - u16 tx_s; - enum ccid3_hc_tx_states tx_state:8; - u8 tx_last_win_count; - ktime_t tx_t_last_win_count; - struct timer_list tx_no_feedback_timer; - struct sock *sk; - ktime_t tx_t_ld; - ktime_t tx_t_nom; - struct tfrc_tx_hist_entry *tx_hist; -}; - -static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk) -{ - struct ccid3_hc_tx_sock *hctx = ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid); - BUG_ON(hctx == NULL); - return hctx; -} - -/* TFRC receiver states */ -enum ccid3_hc_rx_states { - TFRC_RSTATE_NO_DATA = 1, - TFRC_RSTATE_DATA, -}; - -/** - * struct ccid3_hc_rx_sock - CCID3 receiver half-connection socket - * @rx_last_counter: Tracks window counter (RFC 4342, 8.1) - * @rx_state: Receiver state, one of %ccid3_hc_rx_states - * @rx_bytes_recv: Total sum of DCCP payload bytes - * @rx_x_recv: Receiver estimate of send rate (RFC 3448, sec. 4.3) - * @rx_rtt: Receiver estimate of RTT - * @rx_tstamp_last_feedback: Time at which last feedback was sent - * @rx_hist: Packet history (loss detection + RTT sampling) - * @rx_li_hist: Loss Interval database - * @rx_s: Received packet size in bytes - * @rx_pinv: Inverse of Loss Event Rate (RFC 4342, sec. 8.5) - */ -struct ccid3_hc_rx_sock { - u8 rx_last_counter:4; - enum ccid3_hc_rx_states rx_state:8; - u32 rx_bytes_recv; - u32 rx_x_recv; - u32 rx_rtt; - ktime_t rx_tstamp_last_feedback; - struct tfrc_rx_hist rx_hist; - struct tfrc_loss_hist rx_li_hist; - u16 rx_s; -#define rx_pinv rx_li_hist.i_mean -}; - -static inline struct ccid3_hc_rx_sock *ccid3_hc_rx_sk(const struct sock *sk) -{ - struct ccid3_hc_rx_sock *hcrx = ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid); - BUG_ON(hcrx == NULL); - return hcrx; -} - -#endif /* _DCCP_CCID3_H_ */ diff --git a/net/dccp/ccids/lib/loss_interval.c b/net/dccp/ccids/lib/loss_interval.c deleted file mode 100644 index da95319842bb..000000000000 --- a/net/dccp/ccids/lib/loss_interval.c +++ /dev/null @@ -1,184 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * Copyright (c) 2007 The University of Aberdeen, Scotland, UK - * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand. - * Copyright (c) 2005-7 Ian McDonald <ian.mcdonald@jandi.co.nz> - * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br> - */ -#include <net/sock.h> -#include "tfrc.h" - -static struct kmem_cache *tfrc_lh_slab __read_mostly; -/* Loss Interval weights from [RFC 3448, 5.4], scaled by 10 */ -static const int tfrc_lh_weights[NINTERVAL] = { 10, 10, 10, 10, 8, 6, 4, 2 }; - -/* implements LIFO semantics on the array */ -static inline u8 LIH_INDEX(const u8 ctr) -{ - return LIH_SIZE - 1 - (ctr % LIH_SIZE); -} - -/* the `counter' index always points at the next entry to be populated */ -static inline struct tfrc_loss_interval *tfrc_lh_peek(struct tfrc_loss_hist *lh) -{ - return lh->counter ? lh->ring[LIH_INDEX(lh->counter - 1)] : NULL; -} - -/* given i with 0 <= i <= k, return I_i as per the rfc3448bis notation */ -static inline u32 tfrc_lh_get_interval(struct tfrc_loss_hist *lh, const u8 i) -{ - BUG_ON(i >= lh->counter); - return lh->ring[LIH_INDEX(lh->counter - i - 1)]->li_length; -} - -/* - * On-demand allocation and de-allocation of entries - */ -static struct tfrc_loss_interval *tfrc_lh_demand_next(struct tfrc_loss_hist *lh) -{ - if (lh->ring[LIH_INDEX(lh->counter)] == NULL) - lh->ring[LIH_INDEX(lh->counter)] = kmem_cache_alloc(tfrc_lh_slab, - GFP_ATOMIC); - return lh->ring[LIH_INDEX(lh->counter)]; -} - -void tfrc_lh_cleanup(struct tfrc_loss_hist *lh) -{ - if (!tfrc_lh_is_initialised(lh)) - return; - - for (lh->counter = 0; lh->counter < LIH_SIZE; lh->counter++) - if (lh->ring[LIH_INDEX(lh->counter)] != NULL) { - kmem_cache_free(tfrc_lh_slab, - lh->ring[LIH_INDEX(lh->counter)]); - lh->ring[LIH_INDEX(lh->counter)] = NULL; - } -} - -static void tfrc_lh_calc_i_mean(struct tfrc_loss_hist *lh) -{ - u32 i_i, i_tot0 = 0, i_tot1 = 0, w_tot = 0; - int i, k = tfrc_lh_length(lh) - 1; /* k is as in rfc3448bis, 5.4 */ - - if (k <= 0) - return; - - for (i = 0; i <= k; i++) { - i_i = tfrc_lh_get_interval(lh, i); - - if (i < k) { - i_tot0 += i_i * tfrc_lh_weights[i]; - w_tot += tfrc_lh_weights[i]; - } - if (i > 0) - i_tot1 += i_i * tfrc_lh_weights[i-1]; - } - - lh->i_mean = max(i_tot0, i_tot1) / w_tot; -} - -/** - * tfrc_lh_update_i_mean - Update the `open' loss interval I_0 - * @lh: histogram to update - * @skb: received socket triggering loss interval update - * - * For recomputing p: returns `true' if p > p_prev <=> 1/p < 1/p_prev - */ -u8 tfrc_lh_update_i_mean(struct tfrc_loss_hist *lh, struct sk_buff *skb) -{ - struct tfrc_loss_interval *cur = tfrc_lh_peek(lh); - u32 old_i_mean = lh->i_mean; - s64 len; - - if (cur == NULL) /* not initialised */ - return 0; - - len = dccp_delta_seqno(cur->li_seqno, DCCP_SKB_CB(skb)->dccpd_seq) + 1; - - if (len - (s64)cur->li_length <= 0) /* duplicate or reordered */ - return 0; - - if (SUB16(dccp_hdr(skb)->dccph_ccval, cur->li_ccval) > 4) - /* - * Implements RFC 4342, 10.2: - * If a packet S (skb) exists whose seqno comes `after' the one - * starting the current loss interval (cur) and if the modulo-16 - * distance from C(cur) to C(S) is greater than 4, consider all - * subsequent packets as belonging to a new loss interval. This - * test is necessary since CCVal may wrap between intervals. - */ - cur->li_is_closed = 1; - - if (tfrc_lh_length(lh) == 1) /* due to RFC 3448, 6.3.1 */ - return 0; - - cur->li_length = len; - tfrc_lh_calc_i_mean(lh); - - return lh->i_mean < old_i_mean; -} - -/* Determine if `new_loss' does begin a new loss interval [RFC 4342, 10.2] */ -static inline u8 tfrc_lh_is_new_loss(struct tfrc_loss_interval *cur, - struct tfrc_rx_hist_entry *new_loss) -{ - return dccp_delta_seqno(cur->li_seqno, new_loss->tfrchrx_seqno) > 0 && - (cur->li_is_closed || SUB16(new_loss->tfrchrx_ccval, cur->li_ccval) > 4); -} - -/** - * tfrc_lh_interval_add - Insert new record into the Loss Interval database - * @lh: Loss Interval database - * @rh: Receive history containing a fresh loss event - * @calc_first_li: Caller-dependent routine to compute length of first interval - * @sk: Used by @calc_first_li in caller-specific way (subtyping) - * - * Updates I_mean and returns 1 if a new interval has in fact been added to @lh. - */ -int tfrc_lh_interval_add(struct tfrc_loss_hist *lh, struct tfrc_rx_hist *rh, - u32 (*calc_first_li)(struct sock *), struct sock *sk) -{ - struct tfrc_loss_interval *cur = tfrc_lh_peek(lh), *new; - - if (cur != NULL && !tfrc_lh_is_new_loss(cur, tfrc_rx_hist_loss_prev(rh))) - return 0; - - new = tfrc_lh_demand_next(lh); - if (unlikely(new == NULL)) { - DCCP_CRIT("Cannot allocate/add loss record."); - return 0; - } - - new->li_seqno = tfrc_rx_hist_loss_prev(rh)->tfrchrx_seqno; - new->li_ccval = tfrc_rx_hist_loss_prev(rh)->tfrchrx_ccval; - new->li_is_closed = 0; - - if (++lh->counter == 1) - lh->i_mean = new->li_length = (*calc_first_li)(sk); - else { - cur->li_length = dccp_delta_seqno(cur->li_seqno, new->li_seqno); - new->li_length = dccp_delta_seqno(new->li_seqno, - tfrc_rx_hist_last_rcv(rh)->tfrchrx_seqno) + 1; - if (lh->counter > (2*LIH_SIZE)) - lh->counter -= LIH_SIZE; - - tfrc_lh_calc_i_mean(lh); - } - return 1; -} - -int __init tfrc_li_init(void) -{ - tfrc_lh_slab = kmem_cache_create("tfrc_li_hist", - sizeof(struct tfrc_loss_interval), 0, - SLAB_HWCACHE_ALIGN, NULL); - return tfrc_lh_slab == NULL ? -ENOBUFS : 0; -} - -void tfrc_li_exit(void) -{ - if (tfrc_lh_slab != NULL) { - kmem_cache_destroy(tfrc_lh_slab); - tfrc_lh_slab = NULL; - } -} diff --git a/net/dccp/ccids/lib/loss_interval.h b/net/dccp/ccids/lib/loss_interval.h deleted file mode 100644 index c3d95f85e43b..000000000000 --- a/net/dccp/ccids/lib/loss_interval.h +++ /dev/null @@ -1,69 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -#ifndef _DCCP_LI_HIST_ -#define _DCCP_LI_HIST_ -/* - * Copyright (c) 2007 The University of Aberdeen, Scotland, UK - * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand. - * Copyright (c) 2005-7 Ian McDonald <ian.mcdonald@jandi.co.nz> - * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br> - */ -#include <linux/ktime.h> -#include <linux/list.h> -#include <linux/slab.h> - -/* - * Number of loss intervals (RFC 4342, 8.6.1). The history size is one more than - * NINTERVAL, since the `open' interval I_0 is always stored as the first entry. - */ -#define NINTERVAL 8 -#define LIH_SIZE (NINTERVAL + 1) - -/** - * tfrc_loss_interval - Loss history record for TFRC-based protocols - * @li_seqno: Highest received seqno before the start of loss - * @li_ccval: The CCVal belonging to @li_seqno - * @li_is_closed: Whether @li_seqno is older than 1 RTT - * @li_length: Loss interval sequence length - */ -struct tfrc_loss_interval { - u64 li_seqno:48, - li_ccval:4, - li_is_closed:1; - u32 li_length; -}; - -/** - * tfrc_loss_hist - Loss record database - * @ring: Circular queue managed in LIFO manner - * @counter: Current count of entries (can be more than %LIH_SIZE) - * @i_mean: Current Average Loss Interval [RFC 3448, 5.4] - */ -struct tfrc_loss_hist { - struct tfrc_loss_interval *ring[LIH_SIZE]; - u8 counter; - u32 i_mean; -}; - -static inline void tfrc_lh_init(struct tfrc_loss_hist *lh) -{ - memset(lh, 0, sizeof(struct tfrc_loss_hist)); -} - -static inline u8 tfrc_lh_is_initialised(struct tfrc_loss_hist *lh) -{ - return lh->counter > 0; -} - -static inline u8 tfrc_lh_length(struct tfrc_loss_hist *lh) -{ - return min(lh->counter, (u8)LIH_SIZE); -} - -struct tfrc_rx_hist; - -int tfrc_lh_interval_add(struct tfrc_loss_hist *, struct tfrc_rx_hist *, - u32 (*first_li)(struct sock *), struct sock *); -u8 tfrc_lh_update_i_mean(struct tfrc_loss_hist *lh, struct sk_buff *); -void tfrc_lh_cleanup(struct tfrc_loss_hist *lh); - -#endif /* _DCCP_LI_HIST_ */ diff --git a/net/dccp/ccids/lib/packet_history.c b/net/dccp/ccids/lib/packet_history.c deleted file mode 100644 index 0cdda3c66fb5..000000000000 --- a/net/dccp/ccids/lib/packet_history.c +++ /dev/null @@ -1,439 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * Copyright (c) 2007 The University of Aberdeen, Scotland, UK - * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand. - * - * An implementation of the DCCP protocol - * - * This code has been developed by the University of Waikato WAND - * research group. For further information please see https://www.wand.net.nz/ - * or e-mail Ian McDonald - ian.mcdonald@jandi.co.nz - * - * This code also uses code from Lulea University, rereleased as GPL by its - * authors: - * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon - * - * Changes to meet Linux coding standards, to make it meet latest ccid3 draft - * and to make it work as a loadable module in the DCCP stack written by - * Arnaldo Carvalho de Melo <acme@conectiva.com.br>. - * - * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br> - */ - -#include <linux/string.h> -#include <linux/slab.h> -#include "packet_history.h" -#include "../../dccp.h" - -/* - * Transmitter History Routines - */ -static struct kmem_cache *tfrc_tx_hist_slab; - -int __init tfrc_tx_packet_history_init(void) -{ - tfrc_tx_hist_slab = kmem_cache_create("tfrc_tx_hist", - sizeof(struct tfrc_tx_hist_entry), - 0, SLAB_HWCACHE_ALIGN, NULL); - return tfrc_tx_hist_slab == NULL ? -ENOBUFS : 0; -} - -void tfrc_tx_packet_history_exit(void) -{ - if (tfrc_tx_hist_slab != NULL) { - kmem_cache_destroy(tfrc_tx_hist_slab); - tfrc_tx_hist_slab = NULL; - } -} - -int tfrc_tx_hist_add(struct tfrc_tx_hist_entry **headp, u64 seqno) -{ - struct tfrc_tx_hist_entry *entry = kmem_cache_alloc(tfrc_tx_hist_slab, gfp_any()); - - if (entry == NULL) - return -ENOBUFS; - entry->seqno = seqno; - entry->stamp = ktime_get_real(); - entry->next = *headp; - *headp = entry; - return 0; -} - -void tfrc_tx_hist_purge(struct tfrc_tx_hist_entry **headp) -{ - struct tfrc_tx_hist_entry *head = *headp; - - while (head != NULL) { - struct tfrc_tx_hist_entry *next = head->next; - - kmem_cache_free(tfrc_tx_hist_slab, head); - head = next; - } - - *headp = NULL; -} - -/* - * Receiver History Routines - */ -static struct kmem_cache *tfrc_rx_hist_slab; - -int __init tfrc_rx_packet_history_init(void) -{ - tfrc_rx_hist_slab = kmem_cache_create("tfrc_rxh_cache", - sizeof(struct tfrc_rx_hist_entry), - 0, SLAB_HWCACHE_ALIGN, NULL); - return tfrc_rx_hist_slab == NULL ? -ENOBUFS : 0; -} - -void tfrc_rx_packet_history_exit(void) -{ - if (tfrc_rx_hist_slab != NULL) { - kmem_cache_destroy(tfrc_rx_hist_slab); - tfrc_rx_hist_slab = NULL; - } -} - -static inline void tfrc_rx_hist_entry_from_skb(struct tfrc_rx_hist_entry *entry, - const struct sk_buff *skb, - const u64 ndp) -{ - const struct dccp_hdr *dh = dccp_hdr(skb); - - entry->tfrchrx_seqno = DCCP_SKB_CB(skb)->dccpd_seq; - entry->tfrchrx_ccval = dh->dccph_ccval; - entry->tfrchrx_type = dh->dccph_type; - entry->tfrchrx_ndp = ndp; - entry->tfrchrx_tstamp = ktime_get_real(); -} - -void tfrc_rx_hist_add_packet(struct tfrc_rx_hist *h, - const struct sk_buff *skb, - const u64 ndp) -{ - struct tfrc_rx_hist_entry *entry = tfrc_rx_hist_last_rcv(h); - - tfrc_rx_hist_entry_from_skb(entry, skb, ndp); -} - -/* has the packet contained in skb been seen before? */ -int tfrc_rx_hist_duplicate(struct tfrc_rx_hist *h, struct sk_buff *skb) -{ - const u64 seq = DCCP_SKB_CB(skb)->dccpd_seq; - int i; - - if (dccp_delta_seqno(tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno, seq) <= 0) - return 1; - - for (i = 1; i <= h->loss_count; i++) - if (tfrc_rx_hist_entry(h, i)->tfrchrx_seqno == seq) - return 1; - - return 0; -} - -static void tfrc_rx_hist_swap(struct tfrc_rx_hist *h, const u8 a, const u8 b) -{ - const u8 idx_a = tfrc_rx_hist_index(h, a), - idx_b = tfrc_rx_hist_index(h, b); - - swap(h->ring[idx_a], h->ring[idx_b]); -} - -/* - * Private helper functions for loss detection. - * - * In the descriptions, `Si' refers to the sequence number of entry number i, - * whose NDP count is `Ni' (lower case is used for variables). - * Note: All __xxx_loss functions expect that a test against duplicates has been - * performed already: the seqno of the skb must not be less than the seqno - * of loss_prev; and it must not equal that of any valid history entry. - */ -static void __do_track_loss(struct tfrc_rx_hist *h, struct sk_buff *skb, u64 n1) -{ - u64 s0 = tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno, - s1 = DCCP_SKB_CB(skb)->dccpd_seq; - - if (!dccp_loss_free(s0, s1, n1)) { /* gap between S0 and S1 */ - h->loss_count = 1; - tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 1), skb, n1); - } -} - -static void __one_after_loss(struct tfrc_rx_hist *h, struct sk_buff *skb, u32 n2) -{ - u64 s0 = tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno, - s1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_seqno, - s2 = DCCP_SKB_CB(skb)->dccpd_seq; - - if (likely(dccp_delta_seqno(s1, s2) > 0)) { /* S1 < S2 */ - h->loss_count = 2; - tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 2), skb, n2); - return; - } - - /* S0 < S2 < S1 */ - - if (dccp_loss_free(s0, s2, n2)) { - u64 n1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_ndp; - - if (dccp_loss_free(s2, s1, n1)) { - /* hole is filled: S0, S2, and S1 are consecutive */ - h->loss_count = 0; - h->loss_start = tfrc_rx_hist_index(h, 1); - } else - /* gap between S2 and S1: just update loss_prev */ - tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_loss_prev(h), skb, n2); - - } else { /* gap between S0 and S2 */ - /* - * Reorder history to insert S2 between S0 and S1 - */ - tfrc_rx_hist_swap(h, 0, 3); - h->loss_start = tfrc_rx_hist_index(h, 3); - tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 1), skb, n2); - h->loss_count = 2; - } -} - -/* return 1 if a new loss event has been identified */ -static int __two_after_loss(struct tfrc_rx_hist *h, struct sk_buff *skb, u32 n3) -{ - u64 s0 = tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno, - s1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_seqno, - s2 = tfrc_rx_hist_entry(h, 2)->tfrchrx_seqno, - s3 = DCCP_SKB_CB(skb)->dccpd_seq; - - if (likely(dccp_delta_seqno(s2, s3) > 0)) { /* S2 < S3 */ - h->loss_count = 3; - tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 3), skb, n3); - return 1; - } - - /* S3 < S2 */ - - if (dccp_delta_seqno(s1, s3) > 0) { /* S1 < S3 < S2 */ - /* - * Reorder history to insert S3 between S1 and S2 - */ - tfrc_rx_hist_swap(h, 2, 3); - tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 2), skb, n3); - h->loss_count = 3; - return 1; - } - - /* S0 < S3 < S1 */ - - if (dccp_loss_free(s0, s3, n3)) { - u64 n1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_ndp; - - if (dccp_loss_free(s3, s1, n1)) { - /* hole between S0 and S1 filled by S3 */ - u64 n2 = tfrc_rx_hist_entry(h, 2)->tfrchrx_ndp; - - if (dccp_loss_free(s1, s2, n2)) { - /* entire hole filled by S0, S3, S1, S2 */ - h->loss_start = tfrc_rx_hist_index(h, 2); - h->loss_count = 0; - } else { - /* gap remains between S1 and S2 */ - h->loss_start = tfrc_rx_hist_index(h, 1); - h->loss_count = 1; - } - - } else /* gap exists between S3 and S1, loss_count stays at 2 */ - tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_loss_prev(h), skb, n3); - - return 0; - } - - /* - * The remaining case: S0 < S3 < S1 < S2; gap between S0 and S3 - * Reorder history to insert S3 between S0 and S1. - */ - tfrc_rx_hist_swap(h, 0, 3); - h->loss_start = tfrc_rx_hist_index(h, 3); - tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 1), skb, n3); - h->loss_count = 3; - - return 1; -} - -/* recycle RX history records to continue loss detection if necessary */ -static void __three_after_loss(struct tfrc_rx_hist *h) -{ - /* - * At this stage we know already that there is a gap between S0 and S1 - * (since S0 was the highest sequence number received before detecting - * the loss). To recycle the loss record, it is thus only necessary to - * check for other possible gaps between S1/S2 and between S2/S3. - */ - u64 s1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_seqno, - s2 = tfrc_rx_hist_entry(h, 2)->tfrchrx_seqno, - s3 = tfrc_rx_hist_entry(h, 3)->tfrchrx_seqno; - u64 n2 = tfrc_rx_hist_entry(h, 2)->tfrchrx_ndp, - n3 = tfrc_rx_hist_entry(h, 3)->tfrchrx_ndp; - - if (dccp_loss_free(s1, s2, n2)) { - - if (dccp_loss_free(s2, s3, n3)) { - /* no gap between S2 and S3: entire hole is filled */ - h->loss_start = tfrc_rx_hist_index(h, 3); - h->loss_count = 0; - } else { - /* gap between S2 and S3 */ - h->loss_start = tfrc_rx_hist_index(h, 2); - h->loss_count = 1; - } - - } else { /* gap between S1 and S2 */ - h->loss_start = tfrc_rx_hist_index(h, 1); - h->loss_count = 2; - } -} - -/** - * tfrc_rx_handle_loss - Loss detection and further processing - * @h: The non-empty RX history object - * @lh: Loss Intervals database to update - * @skb: Currently received packet - * @ndp: The NDP count belonging to @skb - * @calc_first_li: Caller-dependent computation of first loss interval in @lh - * @sk: Used by @calc_first_li (see tfrc_lh_interval_add) - * - * Chooses action according to pending loss, updates LI database when a new - * loss was detected, and does required post-processing. Returns 1 when caller - * should send feedback, 0 otherwise. - * Since it also takes care of reordering during loss detection and updates the - * records accordingly, the caller should not perform any more RX history - * operations when loss_count is greater than 0 after calling this function. - */ -int tfrc_rx_handle_loss(struct tfrc_rx_hist *h, - struct tfrc_loss_hist *lh, - struct sk_buff *skb, const u64 ndp, - u32 (*calc_first_li)(struct sock *), struct sock *sk) -{ - int is_new_loss = 0; - - if (h->loss_count == 0) { - __do_track_loss(h, skb, ndp); - } else if (h->loss_count == 1) { - __one_after_loss(h, skb, ndp); - } else if (h->loss_count != 2) { - DCCP_BUG("invalid loss_count %d", h->loss_count); - } else if (__two_after_loss(h, skb, ndp)) { - /* - * Update Loss Interval database and recycle RX records - */ - is_new_loss = tfrc_lh_interval_add(lh, h, calc_first_li, sk); - __three_after_loss(h); - } - return is_new_loss; -} - -int tfrc_rx_hist_alloc(struct tfrc_rx_hist *h) -{ - int i; - - for (i = 0; i <= TFRC_NDUPACK; i++) { - h->ring[i] = kmem_cache_alloc(tfrc_rx_hist_slab, GFP_ATOMIC); - if (h->ring[i] == NULL) - goto out_free; - } - - h->loss_count = h->loss_start = 0; - return 0; - -out_free: - while (i-- != 0) { - kmem_cache_free(tfrc_rx_hist_slab, h->ring[i]); - h->ring[i] = NULL; - } - return -ENOBUFS; -} - -void tfrc_rx_hist_purge(struct tfrc_rx_hist *h) -{ - int i; - - for (i = 0; i <= TFRC_NDUPACK; ++i) - if (h->ring[i] != NULL) { - kmem_cache_free(tfrc_rx_hist_slab, h->ring[i]); - h->ring[i] = NULL; - } -} - -/** - * tfrc_rx_hist_rtt_last_s - reference entry to compute RTT samples against - * @h: The non-empty RX history object - */ -static inline struct tfrc_rx_hist_entry * - tfrc_rx_hist_rtt_last_s(const struct tfrc_rx_hist *h) -{ - return h->ring[0]; -} - -/** - * tfrc_rx_hist_rtt_prev_s - previously suitable (wrt rtt_last_s) RTT-sampling entry - * @h: The non-empty RX history object - */ -static inline struct tfrc_rx_hist_entry * - tfrc_rx_hist_rtt_prev_s(const struct tfrc_rx_hist *h) -{ - return h->ring[h->rtt_sample_prev]; -} - -/** - * tfrc_rx_hist_sample_rtt - Sample RTT from timestamp / CCVal - * @h: receive histogram - * @skb: packet containing timestamp. - * - * Based on ideas presented in RFC 4342, 8.1. Returns 0 if it was not able - * to compute a sample with given data - calling function should check this. - */ -u32 tfrc_rx_hist_sample_rtt(struct tfrc_rx_hist *h, const struct sk_buff *skb) -{ - u32 sample = 0, - delta_v = SUB16(dccp_hdr(skb)->dccph_ccval, - tfrc_rx_hist_rtt_last_s(h)->tfrchrx_ccval); - - if (delta_v < 1 || delta_v > 4) { /* unsuitable CCVal delta */ - if (h->rtt_sample_prev == 2) { /* previous candidate stored */ - sample = SUB16(tfrc_rx_hist_rtt_prev_s(h)->tfrchrx_ccval, - tfrc_rx_hist_rtt_last_s(h)->tfrchrx_ccval); - if (sample) - sample = 4 / sample * - ktime_us_delta(tfrc_rx_hist_rtt_prev_s(h)->tfrchrx_tstamp, - tfrc_rx_hist_rtt_last_s(h)->tfrchrx_tstamp); - else /* - * FIXME: This condition is in principle not - * possible but occurs when CCID is used for - * two-way data traffic. I have tried to trace - * it, but the cause does not seem to be here. - */ - DCCP_BUG("please report to dccp@vger.kernel.org" - " => prev = %u, last = %u", - tfrc_rx_hist_rtt_prev_s(h)->tfrchrx_ccval, - tfrc_rx_hist_rtt_last_s(h)->tfrchrx_ccval); - } else if (delta_v < 1) { - h->rtt_sample_prev = 1; - goto keep_ref_for_next_time; - } - - } else if (delta_v == 4) /* optimal match */ - sample = ktime_to_us(net_timedelta(tfrc_rx_hist_rtt_last_s(h)->tfrchrx_tstamp)); - else { /* suboptimal match */ - h->rtt_sample_prev = 2; - goto keep_ref_for_next_time; - } - - if (unlikely(sample > DCCP_SANE_RTT_MAX)) { - DCCP_WARN("RTT sample %u too large, using max\n", sample); - sample = DCCP_SANE_RTT_MAX; - } - - h->rtt_sample_prev = 0; /* use current entry as next reference */ -keep_ref_for_next_time: - - return sample; -} diff --git a/net/dccp/ccids/lib/packet_history.h b/net/dccp/ccids/lib/packet_history.h deleted file mode 100644 index 159cc9326eab..000000000000 --- a/net/dccp/ccids/lib/packet_history.h +++ /dev/null @@ -1,142 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -/* - * Packet RX/TX history data structures and routines for TFRC-based protocols. - * - * Copyright (c) 2007 The University of Aberdeen, Scotland, UK - * Copyright (c) 2005-6 The University of Waikato, Hamilton, New Zealand. - * - * This code has been developed by the University of Waikato WAND - * research group. For further information please see https://www.wand.net.nz/ - * or e-mail Ian McDonald - ian.mcdonald@jandi.co.nz - * - * This code also uses code from Lulea University, rereleased as GPL by its - * authors: - * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon - * - * Changes to meet Linux coding standards, to make it meet latest ccid3 draft - * and to make it work as a loadable module in the DCCP stack written by - * Arnaldo Carvalho de Melo <acme@conectiva.com.br>. - * - * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br> - */ - -#ifndef _DCCP_PKT_HIST_ -#define _DCCP_PKT_HIST_ - -#include <linux/list.h> -#include <linux/slab.h> -#include "tfrc.h" - -/** - * tfrc_tx_hist_entry - Simple singly-linked TX history list - * @next: next oldest entry (LIFO order) - * @seqno: sequence number of this entry - * @stamp: send time of packet with sequence number @seqno - */ -struct tfrc_tx_hist_entry { - struct tfrc_tx_hist_entry *next; - u64 seqno; - ktime_t stamp; -}; - -static inline struct tfrc_tx_hist_entry * - tfrc_tx_hist_find_entry(struct tfrc_tx_hist_entry *head, u64 seqno) -{ - while (head != NULL && head->seqno != seqno) - head = head->next; - return head; -} - -int tfrc_tx_hist_add(struct tfrc_tx_hist_entry **headp, u64 seqno); -void tfrc_tx_hist_purge(struct tfrc_tx_hist_entry **headp); - -/* Subtraction a-b modulo-16, respects circular wrap-around */ -#define SUB16(a, b) (((a) + 16 - (b)) & 0xF) - -/* Number of packets to wait after a missing packet (RFC 4342, 6.1) */ -#define TFRC_NDUPACK 3 - -/** - * tfrc_rx_hist_entry - Store information about a single received packet - * @tfrchrx_seqno: DCCP packet sequence number - * @tfrchrx_ccval: window counter value of packet (RFC 4342, 8.1) - * @tfrchrx_ndp: the NDP count (if any) of the packet - * @tfrchrx_tstamp: actual receive time of packet - */ -struct tfrc_rx_hist_entry { - u64 tfrchrx_seqno:48, - tfrchrx_ccval:4, - tfrchrx_type:4; - u64 tfrchrx_ndp:48; - ktime_t tfrchrx_tstamp; -}; - -/** - * tfrc_rx_hist - RX history structure for TFRC-based protocols - * @ring: Packet history for RTT sampling and loss detection - * @loss_count: Number of entries in circular history - * @loss_start: Movable index (for loss detection) - * @rtt_sample_prev: Used during RTT sampling, points to candidate entry - */ -struct tfrc_rx_hist { - struct tfrc_rx_hist_entry *ring[TFRC_NDUPACK + 1]; - u8 loss_count:2, - loss_start:2; -#define rtt_sample_prev loss_start -}; - -/** - * tfrc_rx_hist_index - index to reach n-th entry after loss_start - */ -static inline u8 tfrc_rx_hist_index(const struct tfrc_rx_hist *h, const u8 n) -{ - return (h->loss_start + n) & TFRC_NDUPACK; -} - -/** - * tfrc_rx_hist_last_rcv - entry with highest-received-seqno so far - */ -static inline struct tfrc_rx_hist_entry * - tfrc_rx_hist_last_rcv(const struct tfrc_rx_hist *h) -{ - return h->ring[tfrc_rx_hist_index(h, h->loss_count)]; -} - -/** - * tfrc_rx_hist_entry - return the n-th history entry after loss_start - */ -static inline struct tfrc_rx_hist_entry * - tfrc_rx_hist_entry(const struct tfrc_rx_hist *h, const u8 n) -{ - return h->ring[tfrc_rx_hist_index(h, n)]; -} - -/** - * tfrc_rx_hist_loss_prev - entry with highest-received-seqno before loss was detected - */ -static inline struct tfrc_rx_hist_entry * - tfrc_rx_hist_loss_prev(const struct tfrc_rx_hist *h) -{ - return h->ring[h->loss_start]; -} - -/* indicate whether previously a packet was detected missing */ -static inline bool tfrc_rx_hist_loss_pending(const struct tfrc_rx_hist *h) -{ - return h->loss_count > 0; -} - -void tfrc_rx_hist_add_packet(struct tfrc_rx_hist *h, const struct sk_buff *skb, - const u64 ndp); - -int tfrc_rx_hist_duplicate(struct tfrc_rx_hist *h, struct sk_buff *skb); - -struct tfrc_loss_hist; -int tfrc_rx_handle_loss(struct tfrc_rx_hist *h, struct tfrc_loss_hist *lh, - struct sk_buff *skb, const u64 ndp, - u32 (*first_li)(struct sock *sk), struct sock *sk); -u32 tfrc_rx_hist_sample_rtt(struct tfrc_rx_hist *h, const struct sk_buff *skb); -int tfrc_rx_hist_alloc(struct tfrc_rx_hist *h); -void tfrc_rx_hist_purge(struct tfrc_rx_hist *h); - -#endif /* _DCCP_PKT_HIST_ */ diff --git a/net/dccp/ccids/lib/tfrc.c b/net/dccp/ccids/lib/tfrc.c deleted file mode 100644 index d7f265e1f50c..000000000000 --- a/net/dccp/ccids/lib/tfrc.c +++ /dev/null @@ -1,46 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * TFRC library initialisation - * - * Copyright (c) 2007 The University of Aberdeen, Scotland, UK - * Copyright (c) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> - */ -#include <linux/moduleparam.h> -#include "tfrc.h" - -#ifdef CONFIG_IP_DCCP_TFRC_DEBUG -bool tfrc_debug; -module_param(tfrc_debug, bool, 0644); -MODULE_PARM_DESC(tfrc_debug, "Enable TFRC debug messages"); -#endif - -int __init tfrc_lib_init(void) -{ - int rc = tfrc_li_init(); - - if (rc) - goto out; - - rc = tfrc_tx_packet_history_init(); - if (rc) - goto out_free_loss_intervals; - - rc = tfrc_rx_packet_history_init(); - if (rc) - goto out_free_tx_history; - return 0; - -out_free_tx_history: - tfrc_tx_packet_history_exit(); -out_free_loss_intervals: - tfrc_li_exit(); -out: - return rc; -} - -void tfrc_lib_exit(void) -{ - tfrc_rx_packet_history_exit(); - tfrc_tx_packet_history_exit(); - tfrc_li_exit(); -} diff --git a/net/dccp/ccids/lib/tfrc.h b/net/dccp/ccids/lib/tfrc.h deleted file mode 100644 index 0a63e8750cc5..000000000000 --- a/net/dccp/ccids/lib/tfrc.h +++ /dev/null @@ -1,73 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -#ifndef _TFRC_H_ -#define _TFRC_H_ -/* - * Copyright (c) 2007 The University of Aberdeen, Scotland, UK - * Copyright (c) 2005-6 The University of Waikato, Hamilton, New Zealand. - * Copyright (c) 2005-6 Ian McDonald <ian.mcdonald@jandi.co.nz> - * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br> - * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon - */ -#include <linux/types.h> -#include <linux/math64.h> -#include "../../dccp.h" - -/* internal includes that this library exports: */ -#include "loss_interval.h" -#include "packet_history.h" - -#ifdef CONFIG_IP_DCCP_TFRC_DEBUG -extern bool tfrc_debug; -#define tfrc_pr_debug(format, a...) DCCP_PR_DEBUG(tfrc_debug, format, ##a) -#else -#define tfrc_pr_debug(format, a...) -#endif - -/* integer-arithmetic divisions of type (a * 1000000)/b */ -static inline u64 scaled_div(u64 a, u64 b) -{ - BUG_ON(b == 0); - return div64_u64(a * 1000000, b); -} - -static inline u32 scaled_div32(u64 a, u64 b) -{ - u64 result = scaled_div(a, b); - - if (result > UINT_MAX) { - DCCP_CRIT("Overflow: %llu/%llu > UINT_MAX", - (unsigned long long)a, (unsigned long long)b); - return UINT_MAX; - } - return result; -} - -/** - * tfrc_ewma - Exponentially weighted moving average - * @weight: Weight to be used as damping factor, in units of 1/10 - */ -static inline u32 tfrc_ewma(const u32 avg, const u32 newval, const u8 weight) -{ - return avg ? (weight * avg + (10 - weight) * newval) / 10 : newval; -} - -u32 tfrc_calc_x(u16 s, u32 R, u32 p); -u32 tfrc_calc_x_reverse_lookup(u32 fvalue); -u32 tfrc_invert_loss_event_rate(u32 loss_event_rate); - -int tfrc_tx_packet_history_init(void); -void tfrc_tx_packet_history_exit(void); -int tfrc_rx_packet_history_init(void); -void tfrc_rx_packet_history_exit(void); - -int tfrc_li_init(void); -void tfrc_li_exit(void); - -#ifdef CONFIG_IP_DCCP_TFRC_LIB -int tfrc_lib_init(void); -void tfrc_lib_exit(void); -#else -#define tfrc_lib_init() (0) -#define tfrc_lib_exit() -#endif -#endif /* _TFRC_H_ */ diff --git a/net/dccp/ccids/lib/tfrc_equation.c b/net/dccp/ccids/lib/tfrc_equation.c deleted file mode 100644 index 92a8c6bea316..000000000000 --- a/net/dccp/ccids/lib/tfrc_equation.c +++ /dev/null @@ -1,702 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand. - * Copyright (c) 2005 Ian McDonald <ian.mcdonald@jandi.co.nz> - * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br> - * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon - */ - -#include <linux/module.h> -#include "../../dccp.h" -#include "tfrc.h" - -#define TFRC_CALC_X_ARRSIZE 500 -#define TFRC_CALC_X_SPLIT 50000 /* 0.05 * 1000000, details below */ -#define TFRC_SMALLEST_P (TFRC_CALC_X_SPLIT/TFRC_CALC_X_ARRSIZE) - -/* - TFRC TCP Reno Throughput Equation Lookup Table for f(p) - - The following two-column lookup table implements a part of the TCP throughput - equation from [RFC 3448, sec. 3.1]: - - s - X_calc = -------------------------------------------------------------- - R * sqrt(2*b*p/3) + (3 * t_RTO * sqrt(3*b*p/8) * (p + 32*p^3)) - - Where: - X is the transmit rate in bytes/second - s is the packet size in bytes - R is the round trip time in seconds - p is the loss event rate, between 0 and 1.0, of the number of loss - events as a fraction of the number of packets transmitted - t_RTO is the TCP retransmission timeout value in seconds - b is the number of packets acknowledged by a single TCP ACK - - We can assume that b = 1 and t_RTO is 4 * R. The equation now becomes: - - s - X_calc = ------------------------------------------------------- - R * sqrt(p*2/3) + (12 * R * sqrt(p*3/8) * (p + 32*p^3)) - - which we can break down into: - - s - X_calc = --------- - R * f(p) - - where f(p) is given for 0 < p <= 1 by: - - f(p) = sqrt(2*p/3) + 12 * sqrt(3*p/8) * (p + 32*p^3) - - Since this is kernel code, floating-point arithmetic is avoided in favour of - integer arithmetic. This means that nearly all fractional parameters are - scaled by 1000000: - * the parameters p and R - * the return result f(p) - The lookup table therefore actually tabulates the following function g(q): - - g(q) = 1000000 * f(q/1000000) - - Hence, when p <= 1, q must be less than or equal to 1000000. To achieve finer - granularity for the practically more relevant case of small values of p (up to - 5%), the second column is used; the first one ranges up to 100%. This split - corresponds to the value of q = TFRC_CALC_X_SPLIT. At the same time this also - determines the smallest resolution possible with this lookup table: - - TFRC_SMALLEST_P = TFRC_CALC_X_SPLIT / TFRC_CALC_X_ARRSIZE - - The entire table is generated by: - for(i=0; i < TFRC_CALC_X_ARRSIZE; i++) { - lookup[i][0] = g((i+1) * 1000000/TFRC_CALC_X_ARRSIZE); - lookup[i][1] = g((i+1) * TFRC_CALC_X_SPLIT/TFRC_CALC_X_ARRSIZE); - } - - With the given configuration, we have, with M = TFRC_CALC_X_ARRSIZE-1, - lookup[0][0] = g(1000000/(M+1)) = 1000000 * f(0.2%) - lookup[M][0] = g(1000000) = 1000000 * f(100%) - lookup[0][1] = g(TFRC_SMALLEST_P) = 1000000 * f(0.01%) - lookup[M][1] = g(TFRC_CALC_X_SPLIT) = 1000000 * f(5%) - - In summary, the two columns represent f(p) for the following ranges: - * The first column is for 0.002 <= p <= 1.0 - * The second column is for 0.0001 <= p <= 0.05 - Where the columns overlap, the second (finer-grained) is given preference, - i.e. the first column is used only for p >= 0.05. - */ -static const u32 tfrc_calc_x_lookup[TFRC_CALC_X_ARRSIZE][2] = { - { 37172, 8172 }, - { 53499, 11567 }, - { 66664, 14180 }, - { 78298, 16388 }, - { 89021, 18339 }, - { 99147, 20108 }, - { 108858, 21738 }, - { 118273, 23260 }, - { 127474, 24693 }, - { 136520, 26052 }, - { 145456, 27348 }, - { 154316, 28589 }, - { 163130, 29783 }, - { 171919, 30935 }, - { 180704, 32049 }, - { 189502, 33130 }, - { 198328, 34180 }, - { 207194, 35202 }, - { 216114, 36198 }, - { 225097, 37172 }, - { 234153, 38123 }, - { 243294, 39055 }, - { 252527, 39968 }, - { 261861, 40864 }, - { 271305, 41743 }, - { 280866, 42607 }, - { 290553, 43457 }, - { 300372, 44293 }, - { 310333, 45117 }, - { 320441, 45929 }, - { 330705, 46729 }, - { 341131, 47518 }, - { 351728, 48297 }, - { 362501, 49066 }, - { 373460, 49826 }, - { 384609, 50577 }, - { 395958, 51320 }, - { 407513, 52054 }, - { 419281, 52780 }, - { 431270, 53499 }, - { 443487, 54211 }, - { 455940, 54916 }, - { 468635, 55614 }, - { 481581, 56306 }, - { 494785, 56991 }, - { 508254, 57671 }, - { 521996, 58345 }, - { 536019, 59014 }, - { 550331, 59677 }, - { 564939, 60335 }, - { 579851, 60988 }, - { 595075, 61636 }, - { 610619, 62279 }, - { 626491, 62918 }, - { 642700, 63553 }, - { 659253, 64183 }, - { 676158, 64809 }, - { 693424, 65431 }, - { 711060, 66050 }, - { 729073, 66664 }, - { 747472, 67275 }, - { 766266, 67882 }, - { 785464, 68486 }, - { 805073, 69087 }, - { 825103, 69684 }, - { 845562, 70278 }, - { 866460, 70868 }, - { 887805, 71456 }, - { 909606, 72041 }, - { 931873, 72623 }, - { 954614, 73202 }, - { 977839, 73778 }, - { 1001557, 74352 }, - { 1025777, 74923 }, - { 1050508, 75492 }, - { 1075761, 76058 }, - { 1101544, 76621 }, - { 1127867, 77183 }, - { 1154739, 77741 }, - { 1182172, 78298 }, - { 1210173, 78852 }, - { 1238753, 79405 }, - { 1267922, 79955 }, - { 1297689, 80503 }, - { 1328066, 81049 }, - { 1359060, 81593 }, - { 1390684, 82135 }, - { 1422947, 82675 }, - { 1455859, 83213 }, - { 1489430, 83750 }, - { 1523671, 84284 }, - { 1558593, 84817 }, - { 1594205, 85348 }, - { 1630518, 85878 }, - { 1667543, 86406 }, - { 1705290, 86932 }, - { 1743770, 87457 }, - { 1782994, 87980 }, - { 1822973, 88501 }, - { 1863717, 89021 }, - { 1905237, 89540 }, - { 1947545, 90057 }, - { 1990650, 90573 }, - { 2034566, 91087 }, - { 2079301, 91600 }, - { 2124869, 92111 }, - { 2171279, 92622 }, - { 2218543, 93131 }, - { 2266673, 93639 }, - { 2315680, 94145 }, - { 2365575, 94650 }, - { 2416371, 95154 }, - { 2468077, 95657 }, - { 2520707, 96159 }, - { 2574271, 96660 }, - { 2628782, 97159 }, - { 2684250, 97658 }, - { 2740689, 98155 }, - { 2798110, 98651 }, - { 2856524, 99147 }, - { 2915944, 99641 }, - { 2976382, 100134 }, - { 3037850, 100626 }, - { 3100360, 101117 }, - { 3163924, 101608 }, - { 3228554, 102097 }, - { 3294263, 102586 }, - { 3361063, 103073 }, - { 3428966, 103560 }, - { 3497984, 104045 }, - { 3568131, 104530 }, - { 3639419, 105014 }, - { 3711860, 105498 }, - { 3785467, 105980 }, - { 3860253, 106462 }, - { 3936229, 106942 }, - { 4013410, 107422 }, - { 4091808, 107902 }, - { 4171435, 108380 }, - { 4252306, 108858 }, - { 4334431, 109335 }, - { 4417825, 109811 }, - { 4502501, 110287 }, - { 4588472, 110762 }, - { 4675750, 111236 }, - { 4764349, 111709 }, - { 4854283, 112182 }, - { 4945564, 112654 }, - { 5038206, 113126 }, - { 5132223, 113597 }, - { 5227627, 114067 }, - { 5324432, 114537 }, - { 5422652, 115006 }, - { 5522299, 115474 }, - { 5623389, 115942 }, - { 5725934, 116409 }, - { 5829948, 116876 }, - { 5935446, 117342 }, - { 6042439, 117808 }, - { 6150943, 118273 }, - { 6260972, 118738 }, - { 6372538, 119202 }, - { 6485657, 119665 }, - { 6600342, 120128 }, - { 6716607, 120591 }, - { 6834467, 121053 }, - { 6953935, 121514 }, - { 7075025, 121976 }, - { 7197752, 122436 }, - { 7322131, 122896 }, - { 7448175, 123356 }, - { 7575898, 123815 }, - { 7705316, 124274 }, - { 7836442, 124733 }, - { 7969291, 125191 }, - { 8103877, 125648 }, - { 8240216, 126105 }, - { 8378321, 126562 }, - { 8518208, 127018 }, - { 8659890, 127474 }, - { 8803384, 127930 }, - { 8948702, 128385 }, - { 9095861, 128840 }, - { 9244875, 129294 }, - { 9395760, 129748 }, - { 9548529, 130202 }, - { 9703198, 130655 }, - { 9859782, 131108 }, - { 10018296, 131561 }, - { 10178755, 132014 }, - { 10341174, 132466 }, - { 10505569, 132917 }, - { 10671954, 133369 }, - { 10840345, 133820 }, - { 11010757, 134271 }, - { 11183206, 134721 }, - { 11357706, 135171 }, - { 11534274, 135621 }, - { 11712924, 136071 }, - { 11893673, 136520 }, - { 12076536, 136969 }, - { 12261527, 137418 }, - { 12448664, 137867 }, - { 12637961, 138315 }, - { 12829435, 138763 }, - { 13023101, 139211 }, - { 13218974, 139658 }, - { 13417071, 140106 }, - { 13617407, 140553 }, - { 13819999, 140999 }, - { 14024862, 141446 }, - { 14232012, 141892 }, - { 14441465, 142339 }, - { 14653238, 142785 }, - { 14867346, 143230 }, - { 15083805, 143676 }, - { 15302632, 144121 }, - { 15523842, 144566 }, - { 15747453, 145011 }, - { 15973479, 145456 }, - { 16201939, 145900 }, - { 16432847, 146345 }, - { 16666221, 146789 }, - { 16902076, 147233 }, - { 17140429, 147677 }, - { 17381297, 148121 }, - 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{ 204107760, 259518 }, - { 205581862, 259986 }, - { 207063630, 260454 }, - { 208553088, 260923 }, - { 210050262, 261392 }, - { 211555174, 261861 }, - { 213067849, 262331 }, - { 214588312, 262800 }, - { 216116586, 263270 }, - { 217652696, 263741 }, - { 219196666, 264211 }, - { 220748520, 264682 }, - { 222308282, 265153 }, - { 223875978, 265625 }, - { 225451630, 266097 }, - { 227035265, 266569 }, - { 228626905, 267041 }, - { 230226576, 267514 }, - { 231834302, 267986 }, - { 233450107, 268460 }, - { 235074016, 268933 }, - { 236706054, 269407 }, - { 238346244, 269881 }, - { 239994613, 270355 }, - { 241651183, 270830 }, - { 243315981, 271305 } -}; - -/* return largest index i such that fval <= lookup[i][small] */ -static inline u32 tfrc_binsearch(u32 fval, u8 small) -{ - u32 try, low = 0, high = TFRC_CALC_X_ARRSIZE - 1; - - while (low < high) { - try = (low + high) / 2; - if (fval <= tfrc_calc_x_lookup[try][small]) - high = try; - else - low = try + 1; - } - return high; -} - -/** - * tfrc_calc_x - Calculate the send rate as per section 3.1 of RFC3448 - * @s: packet size in bytes - * @R: RTT scaled by 1000000 (i.e., microseconds) - * @p: loss ratio estimate scaled by 1000000 - * - * Returns X_calc in bytes per second (not scaled). - */ -u32 tfrc_calc_x(u16 s, u32 R, u32 p) -{ - u16 index; - u32 f; - u64 result; - - /* check against invalid parameters and divide-by-zero */ - BUG_ON(p > 1000000); /* p must not exceed 100% */ - BUG_ON(p == 0); /* f(0) = 0, divide by zero */ - if (R == 0) { /* possible divide by zero */ - DCCP_CRIT("WARNING: RTT is 0, returning maximum X_calc."); - return ~0U; - } - - if (p <= TFRC_CALC_X_SPLIT) { /* 0.0000 < p <= 0.05 */ - if (p < TFRC_SMALLEST_P) { /* 0.0000 < p < 0.0001 */ - DCCP_WARN("Value of p (%d) below resolution. " - "Substituting %d\n", p, TFRC_SMALLEST_P); - index = 0; - } else /* 0.0001 <= p <= 0.05 */ - index = p/TFRC_SMALLEST_P - 1; - - f = tfrc_calc_x_lookup[index][1]; - - } else { /* 0.05 < p <= 1.00 */ - index = p/(1000000/TFRC_CALC_X_ARRSIZE) - 1; - - f = tfrc_calc_x_lookup[index][0]; - } - - /* - * Compute X = s/(R*f(p)) in bytes per second. - * Since f(p) and R are both scaled by 1000000, we need to multiply by - * 1000000^2. To avoid overflow, the result is computed in two stages. - * This works under almost all reasonable operational conditions, for a - * wide range of parameters. Yet, should some strange combination of - * parameters result in overflow, the use of scaled_div32 will catch - * this and return UINT_MAX - which is a logically adequate consequence. - */ - result = scaled_div(s, R); - return scaled_div32(result, f); -} - -/** - * tfrc_calc_x_reverse_lookup - try to find p given f(p) - * @fvalue: function value to match, scaled by 1000000 - * - * Returns closest match for p, also scaled by 1000000 - */ -u32 tfrc_calc_x_reverse_lookup(u32 fvalue) -{ - int index; - - if (fvalue == 0) /* f(p) = 0 whenever p = 0 */ - return 0; - - /* Error cases. */ - if (fvalue < tfrc_calc_x_lookup[0][1]) { - DCCP_WARN("fvalue %u smaller than resolution\n", fvalue); - return TFRC_SMALLEST_P; - } - if (fvalue > tfrc_calc_x_lookup[TFRC_CALC_X_ARRSIZE - 1][0]) { - DCCP_WARN("fvalue %u exceeds bounds!\n", fvalue); - return 1000000; - } - - if (fvalue <= tfrc_calc_x_lookup[TFRC_CALC_X_ARRSIZE - 1][1]) { - index = tfrc_binsearch(fvalue, 1); - return (index + 1) * TFRC_CALC_X_SPLIT / TFRC_CALC_X_ARRSIZE; - } - - /* else ... it must be in the coarse-grained column */ - index = tfrc_binsearch(fvalue, 0); - return (index + 1) * 1000000 / TFRC_CALC_X_ARRSIZE; -} - -/** - * tfrc_invert_loss_event_rate - Compute p so that 10^6 corresponds to 100% - * @loss_event_rate: loss event rate to invert - * When @loss_event_rate is large, there is a chance that p is truncated to 0. - * To avoid re-entering slow-start in that case, we set p = TFRC_SMALLEST_P > 0. - */ -u32 tfrc_invert_loss_event_rate(u32 loss_event_rate) -{ - if (loss_event_rate == UINT_MAX) /* see RFC 4342, 8.5 */ - return 0; - if (unlikely(loss_event_rate == 0)) /* map 1/0 into 100% */ - return 1000000; - return max_t(u32, scaled_div(1, loss_event_rate), TFRC_SMALLEST_P); -} |