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Diffstat (limited to 'net/dccp/ccids/lib/loss_interval.c')
| -rw-r--r-- | net/dccp/ccids/lib/loss_interval.c | 184 |
1 files changed, 0 insertions, 184 deletions
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; - } -} |