[DCCP] loss_interval: Move ccid3_hc_rx_update_li to loss_interval (cc0a910b) · Commits · 戴 / test

net/dccp/ccids/ccid3.c

+9 −170

Original line number	Diff line number	Diff line
		@@ -819,167 +819,6 @@ static int ccid3_hc_rx_insert_options(struct sock sk, struct sk_buff skb)
		return 0;
		}

		/* calculate first loss interval
		*
		* returns estimated loss interval in usecs */

		static u32 ccid3_hc_rx_calc_first_li(struct sock *sk,
		struct list_head *hist_list,
		struct timeval *last_feedback,
		u16 s, u32 bytes_recv,
		u32 previous_x_recv)
		{
		struct dccp_rx_hist_entry entry, next, *tail = NULL;
		u32 x_recv, p;
		suseconds_t rtt, delta;
		struct timeval tstamp = { 0, 0 };
		int interval = 0;
		int win_count = 0;
		int step = 0;
		u64 fval;

		list_for_each_entry_safe(entry, next, hist_list, dccphrx_node) {
		if (dccp_rx_hist_entry_data_packet(entry)) {
		tail = entry;

		switch (step) {
		case 0:
		tstamp = entry->dccphrx_tstamp;
		win_count = entry->dccphrx_ccval;
		step = 1;
		break;
		case 1:
		interval = win_count - entry->dccphrx_ccval;
		if (interval < 0)
		interval += TFRC_WIN_COUNT_LIMIT;
		if (interval > 4)
		goto found;
		break;
		}
		}
		}

		if (unlikely(step == 0)) {
		DCCP_WARN("%s(%p), packet history has no data packets!\n",
		dccp_role(sk), sk);
		return ~0;
		}

		if (unlikely(interval == 0)) {
		DCCP_WARN("%s(%p), Could not find a win_count interval > 0."
		"Defaulting to 1\n", dccp_role(sk), sk);
		interval = 1;
		}
		found:
		if (!tail) {
		DCCP_CRIT("tail is null\n");
		return ~0;
		}

		delta = timeval_delta(&tstamp, &tail->dccphrx_tstamp);
		DCCP_BUG_ON(delta < 0);

		rtt = delta * 4 / interval;
		ccid3_pr_debug("%s(%p), approximated RTT to %dus\n",
		dccp_role(sk), sk, (int)rtt);

		/*
		* 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 [RFC 3448, 6.3.1].
		*/
		if (rtt == 0) { /* would result in divide-by-zero */
		DCCP_WARN("RTT==0\n");
		return ~0;
		}

		dccp_timestamp(sk, &tstamp);
		delta = timeval_delta(&tstamp, last_feedback);
		DCCP_BUG_ON(delta <= 0);

		x_recv = scaled_div32(bytes_recv, delta);
		if (x_recv == 0) { /* would also trigger divide-by-zero */
		DCCP_WARN("X_recv==0\n");
		if (previous_x_recv == 0) {
		DCCP_BUG("stored value of X_recv is zero");
		return ~0;
		}
		x_recv = previous_x_recv;
		}

		fval = scaled_div(s, rtt);
		fval = scaled_div32(fval, x_recv);
		p = tfrc_calc_x_reverse_lookup(fval);

		ccid3_pr_debug("%s(%p), receive rate=%u bytes/s, implied "
		"loss rate=%u\n", dccp_role(sk), sk, x_recv, p);

		if (p == 0)
		return ~0;
		else
		return 1000000 / p;
		}

		static void ccid3_hc_rx_update_li(struct sock *sk,
		struct dccp_li_hist *li_hist,
		struct list_head *li_hist_list,
		struct list_head *hist_list,
		struct timeval *last_feedback,
		u16 s, u32 bytes_recv,
		u32 previous_x_recv,
		u64 seq_loss, u8 win_loss)
		{
		struct dccp_li_hist_entry *head;
		u64 seq_temp;

		if (list_empty(li_hist_list)) {
		if (!dccp_li_hist_interval_new(li_hist, li_hist_list,
		seq_loss, win_loss))
		return;

		head = list_entry(li_hist_list->next, struct dccp_li_hist_entry,
		dccplih_node);
		head->dccplih_interval =
		ccid3_hc_rx_calc_first_li(sk, hist_list,
		last_feedback, s,
		bytes_recv,
		previous_x_recv);
		} else {
		struct dccp_li_hist_entry *entry;
		struct list_head *tail;

		head = list_entry(li_hist_list->next, struct dccp_li_hist_entry,
		dccplih_node);
		/* FIXME win count check removed as was wrong */
		/* should make this check with receive history */
		/* and compare there as per section 10.2 of RFC4342 */

		/* new loss event detected */
		/* calculate last interval length */
		seq_temp = dccp_delta_seqno(head->dccplih_seqno, seq_loss);
		entry = dccp_li_hist_entry_new(li_hist, GFP_ATOMIC);

		if (entry == NULL) {
		DCCP_BUG("out of memory - can not allocate entry");
		return;
		}

		list_add(&entry->dccplih_node, li_hist_list);

		tail = li_hist_list->prev;
		list_del(tail);
		kmem_cache_free(li_hist->dccplih_slab, tail);

		/* Create the newest interval */
		entry->dccplih_seqno = seq_loss;
		entry->dccplih_interval = seq_temp;
		entry->dccplih_win_count = win_loss;
		}
		}

		static int ccid3_hc_rx_detect_loss(struct sock *sk,
		struct dccp_rx_hist_entry *packet)
		{
		@@ -1005,7 +844,7 @@ static int ccid3_hc_rx_detect_loss(struct sock *sk,
		while (dccp_delta_seqno(hcrx->ccid3hcrx_seqno_nonloss, seqno)
		> TFRC_RECV_NUM_LATE_LOSS) {
		loss = 1;
		ccid3_hc_rx_update_li(sk, ccid3_li_hist,
		dccp_li_update_li(sk, ccid3_li_hist,
		&hcrx->ccid3hcrx_li_hist,
		&hcrx->ccid3hcrx_hist,
		&hcrx->ccid3hcrx_tstamp_last_feedback,

net/dccp/ccids/lib/loss_interval.c

+160 −0

Original line number	Diff line number	Diff line
		@@ -15,6 +15,8 @@
		#include <net/sock.h>
		#include "../../dccp.h"
		#include "loss_interval.h"
		#include "packet_history.h"
		#include "tfrc.h"

		struct dccp_li_hist dccp_li_hist_new(const char name)
		{
		@@ -141,3 +143,161 @@ int dccp_li_hist_interval_new(struct dccp_li_hist *hist,
		}

		EXPORT_SYMBOL_GPL(dccp_li_hist_interval_new);

		/* calculate first loss interval
		*
		* returns estimated loss interval in usecs */
		static u32 dccp_li_calc_first_li(struct sock *sk,
		struct list_head *hist_list,
		struct timeval *last_feedback,
		u16 s, u32 bytes_recv,
		u32 previous_x_recv)
		{
		struct dccp_rx_hist_entry entry, next, *tail = NULL;
		u32 x_recv, p;
		suseconds_t rtt, delta;
		struct timeval tstamp = { 0, 0 };
		int interval = 0;
		int win_count = 0;
		int step = 0;
		u64 fval;

		list_for_each_entry_safe(entry, next, hist_list, dccphrx_node) {
		if (dccp_rx_hist_entry_data_packet(entry)) {
		tail = entry;

		switch (step) {
		case 0:
		tstamp = entry->dccphrx_tstamp;
		win_count = entry->dccphrx_ccval;
		step = 1;
		break;
		case 1:
		interval = win_count - entry->dccphrx_ccval;
		if (interval < 0)
		interval += TFRC_WIN_COUNT_LIMIT;
		if (interval > 4)
		goto found;
		break;
		}
		}
		}

		if (unlikely(step == 0)) {
		DCCP_WARN("%s(%p), packet history has no data packets!\n",
		dccp_role(sk), sk);
		return ~0;
		}

		if (unlikely(interval == 0)) {
		DCCP_WARN("%s(%p), Could not find a win_count interval > 0."
		"Defaulting to 1\n", dccp_role(sk), sk);
		interval = 1;
		}
		found:
		if (!tail) {
		DCCP_CRIT("tail is null\n");
		return ~0;
		}

		delta = timeval_delta(&tstamp, &tail->dccphrx_tstamp);
		DCCP_BUG_ON(delta < 0);

		rtt = delta * 4 / interval;
		dccp_pr_debug("%s(%p), approximated RTT to %dus\n",
		dccp_role(sk), sk, (int)rtt);

		/*
		* 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 [RFC 3448, 6.3.1].
		*/
		if (rtt == 0) { /* would result in divide-by-zero */
		DCCP_WARN("RTT==0\n");
		return ~0;
		}

		dccp_timestamp(sk, &tstamp);
		delta = timeval_delta(&tstamp, last_feedback);
		DCCP_BUG_ON(delta <= 0);

		x_recv = scaled_div32(bytes_recv, delta);
		if (x_recv == 0) { /* would also trigger divide-by-zero */
		DCCP_WARN("X_recv==0\n");
		if (previous_x_recv == 0) {
		DCCP_BUG("stored value of X_recv is zero");
		return ~0;
		}
		x_recv = previous_x_recv;
		}

		fval = scaled_div(s, rtt);
		fval = scaled_div32(fval, x_recv);
		p = tfrc_calc_x_reverse_lookup(fval);

		dccp_pr_debug("%s(%p), receive rate=%u bytes/s, implied "
		"loss rate=%u\n", dccp_role(sk), sk, x_recv, p);

		if (p == 0)
		return ~0;
		else
		return 1000000 / p;
		}

		void dccp_li_update_li(struct sock sk, struct dccp_li_hist li_hist,
		struct list_head *li_hist_list,
		struct list_head *hist_list,
		struct timeval *last_feedback, u16 s, u32 bytes_recv,
		u32 previous_x_recv, u64 seq_loss, u8 win_loss)
		{
		struct dccp_li_hist_entry *head;
		u64 seq_temp;

		if (list_empty(li_hist_list)) {
		if (!dccp_li_hist_interval_new(li_hist, li_hist_list,
		seq_loss, win_loss))
		return;

		head = list_entry(li_hist_list->next, struct dccp_li_hist_entry,
		dccplih_node);
		head->dccplih_interval = dccp_li_calc_first_li(sk, hist_list,
		last_feedback,
		s, bytes_recv,
		previous_x_recv);
		} else {
		struct dccp_li_hist_entry *entry;
		struct list_head *tail;

		head = list_entry(li_hist_list->next, struct dccp_li_hist_entry,
		dccplih_node);
		/* FIXME win count check removed as was wrong */
		/* should make this check with receive history */
		/* and compare there as per section 10.2 of RFC4342 */

		/* new loss event detected */
		/* calculate last interval length */
		seq_temp = dccp_delta_seqno(head->dccplih_seqno, seq_loss);
		entry = dccp_li_hist_entry_new(li_hist, GFP_ATOMIC);

		if (entry == NULL) {
		DCCP_BUG("out of memory - can not allocate entry");
		return;
		}

		list_add(&entry->dccplih_node, li_hist_list);

		tail = li_hist_list->prev;
		list_del(tail);
		kmem_cache_free(li_hist->dccplih_slab, tail);

		/* Create the newest interval */
		entry->dccplih_seqno = seq_loss;
		entry->dccplih_interval = seq_temp;
		entry->dccplih_win_count = win_loss;
		}
		}

		EXPORT_SYMBOL_GPL(dccp_li_update_li);

net/dccp/ccids/lib/loss_interval.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -54,4 +54,11 @@ extern u32 dccp_li_hist_calc_i_mean(struct list_head *list);

		extern int dccp_li_hist_interval_new(struct dccp_li_hist *hist,
		struct list_head *list, const u64 seq_loss, const u8 win_loss);

		extern void dccp_li_update_li(struct sock sk, struct dccp_li_hist li_hist,
		struct list_head *li_hist_list,
		struct list_head *hist_list,
		struct timeval *last_feedback, u16 s,
		u32 bytes_recv, u32 previous_x_recv,
		u64 seq_loss, u8 win_loss);
		#endif /* _DCCP_LI_HIST_ */

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