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Diffstat (limited to 'net/dccp/ccids/lib/packet_history.c')
-rw-r--r--net/dccp/ccids/lib/packet_history.c439
1 files changed, 0 insertions, 439 deletions
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;
-}
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