diff options
Diffstat (limited to 'net/dccp/ccids/ccid2.c')
| -rw-r--r-- | net/dccp/ccids/ccid2.c | 794 |
1 files changed, 0 insertions, 794 deletions
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 |