/*
* net/dccp/ccids/ccid3.h
*
- * Copyright (c) 2005-6 The University of Waikato, Hamilton, New Zealand.
+ * 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
*
#ifndef _DCCP_CCID3_H_
#define _DCCP_CCID3_H_
+#include <linux/ktime.h>
#include <linux/list.h>
-#include <linux/time.h>
#include <linux/types.h>
#include <linux/tfrc.h>
+#include "lib/tfrc.h"
#include "../ccid.h"
/* Two seconds as per RFC 3448 4.2 */
#define TFRC_INITIAL_TIMEOUT (2 * USEC_PER_SEC)
-/* In usecs - half the scheduling granularity as per RFC3448 4.6 */
-#define TFRC_OPSYS_HALF_TIME_GRAN (USEC_PER_SEC / (2 * HZ))
-
/* Parameter t_mbi from [RFC 3448, 4.3]: backoff interval in seconds */
#define TFRC_T_MBI 64
+/*
+ * The t_delta parameter (RFC 3448, 4.6): 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))
+#warning Coarse CONFIG_HZ resolution -- higher value recommended for TFRC.
+#endif
+
enum ccid3_options {
TFRC_OPT_LOSS_EVENT_RATE = 192,
TFRC_OPT_LOSS_INTERVALS = 193,
};
struct ccid3_options_received {
- u64 ccid3or_seqno:48,
- ccid3or_loss_intervals_idx:16;
- u16 ccid3or_loss_intervals_len;
u32 ccid3or_loss_event_rate;
u32 ccid3or_receive_rate;
};
/** struct ccid3_hc_tx_sock - CCID3 sender half-connection socket
*
- * @ccid3hctx_x - Current sending rate in 64 * bytes per second
- * @ccid3hctx_x_recv - Receive rate in 64 * bytes per second
- * @ccid3hctx_x_calc - Calculated rate in bytes per second
- * @ccid3hctx_rtt - Estimate of current round trip time in usecs
- * @ccid3hctx_p - Current loss event rate (0-1) scaled by 1000000
- * @ccid3hctx_s - Packet size in bytes
- * @ccid3hctx_t_rto - Nofeedback Timer setting in usecs
- * @ccid3hctx_t_ipi - Interpacket (send) interval (RFC 3448, 4.6) in usecs
- * @ccid3hctx_state - Sender state, one of %ccid3_hc_tx_states
- * @ccid3hctx_last_win_count - Last window counter sent
- * @ccid3hctx_t_last_win_count - Timestamp of earliest packet
- * with last_win_count value sent
- * @ccid3hctx_no_feedback_timer - Handle to no feedback timer
- * @ccid3hctx_idle - Flag indicating that sender is idling
- * @ccid3hctx_t_ld - Time last doubled during slow start
- * @ccid3hctx_t_nom - Nominal send time of next packet
- * @ccid3hctx_delta - Send timer delta (RFC 3448, 4.6) in usecs
- * @ccid3hctx_hist - Packet history
- * @ccid3hctx_options_received - Parsed set of retrieved options
+ * @x - Current sending rate in 64 * bytes per second
+ * @x_recv - Receive rate in 64 * bytes per second
+ * @x_calc - Calculated rate in bytes per second
+ * @rtt - Estimate of current round trip time in usecs
+ * @p - Current loss event rate (0-1) scaled by 1000000
+ * @s - Packet size in bytes
+ * @t_rto - Nofeedback Timer setting in usecs
+ * @t_ipi - Interpacket (send) interval (RFC 3448, 4.6) in usecs
+ * @state - Sender state, one of %ccid3_hc_tx_states
+ * @last_win_count - Last window counter sent
+ * @t_last_win_count - Timestamp of earliest packet with
+ * last_win_count value sent
+ * @no_feedback_timer - Handle to no feedback timer
+ * @t_ld - Time last doubled during slow start
+ * @t_nom - Nominal send time of next packet
+ * @hist - Packet history
+ * @options_received - Parsed set of retrieved options
*/
struct ccid3_hc_tx_sock {
- struct tfrc_tx_info ccid3hctx_tfrc;
-#define ccid3hctx_x ccid3hctx_tfrc.tfrctx_x
-#define ccid3hctx_x_recv ccid3hctx_tfrc.tfrctx_x_recv
-#define ccid3hctx_x_calc ccid3hctx_tfrc.tfrctx_x_calc
-#define ccid3hctx_rtt ccid3hctx_tfrc.tfrctx_rtt
-#define ccid3hctx_p ccid3hctx_tfrc.tfrctx_p
-#define ccid3hctx_t_rto ccid3hctx_tfrc.tfrctx_rto
-#define ccid3hctx_t_ipi ccid3hctx_tfrc.tfrctx_ipi
- u16 ccid3hctx_s;
- enum ccid3_hc_tx_states ccid3hctx_state:8;
- u8 ccid3hctx_last_win_count;
- u8 ccid3hctx_idle;
- struct timeval ccid3hctx_t_last_win_count;
- struct timer_list ccid3hctx_no_feedback_timer;
- struct timeval ccid3hctx_t_ld;
- struct timeval ccid3hctx_t_nom;
- u32 ccid3hctx_delta;
- struct list_head ccid3hctx_hist;
- struct ccid3_options_received ccid3hctx_options_received;
+ u64 x;
+ u64 x_recv;
+ u32 x_calc;
+ u32 rtt;
+ u32 p;
+ u32 t_rto;
+ u32 t_ipi;
+ u16 s;
+ enum ccid3_hc_tx_states state:8;
+ u8 last_win_count;
+ ktime_t t_last_win_count;
+ struct timer_list no_feedback_timer;
+ ktime_t t_ld;
+ ktime_t t_nom;
+ struct tfrc_tx_hist_entry *hist;
+ struct ccid3_options_received options_received;
};
+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,
/** struct ccid3_hc_rx_sock - CCID3 receiver half-connection socket
*
- * @ccid3hcrx_x_recv - Receiver estimate of send rate (RFC 3448 4.3)
- * @ccid3hcrx_rtt - Receiver estimate of rtt (non-standard)
- * @ccid3hcrx_p - current loss event rate (RFC 3448 5.4)
- * @ccid3hcrx_seqno_nonloss - Last received non-loss sequence number
- * @ccid3hcrx_ccval_nonloss - Last received non-loss Window CCVal
- * @ccid3hcrx_ccval_last_counter - Tracks window counter (RFC 4342, 8.1)
- * @ccid3hcrx_state - receiver state, one of %ccid3_hc_rx_states
- * @ccid3hcrx_bytes_recv - Total sum of DCCP payload bytes
- * @ccid3hcrx_tstamp_last_feedback - Time at which last feedback was sent
- * @ccid3hcrx_tstamp_last_ack - Time at which last feedback was sent
- * @ccid3hcrx_hist - Packet history
- * @ccid3hcrx_li_hist - Loss Interval History
- * @ccid3hcrx_s - Received packet size in bytes
- * @ccid3hcrx_pinv - Inverse of Loss Event Rate (RFC 4342, sec. 8.5)
- * @ccid3hcrx_elapsed_time - Time since packet reception
+ * @x_recv - Receiver estimate of send rate (RFC 3448 4.3)
+ * @rtt - Receiver estimate of rtt (non-standard)
+ * @p - Current loss event rate (RFC 3448 5.4)
+ * @last_counter - Tracks window counter (RFC 4342, 8.1)
+ * @state - Receiver state, one of %ccid3_hc_rx_states
+ * @bytes_recv - Total sum of DCCP payload bytes
+ * @x_recv - Receiver estimate of send rate (RFC 3448, sec. 4.3)
+ * @rtt - Receiver estimate of RTT
+ * @tstamp_last_feedback - Time at which last feedback was sent
+ * @tstamp_last_ack - Time at which last feedback was sent
+ * @hist - Packet history (loss detection + RTT sampling)
+ * @li_hist - Loss Interval database
+ * @s - Received packet size in bytes
+ * @p_inverse - Inverse of Loss Event Rate (RFC 4342, sec. 8.5)
*/
struct ccid3_hc_rx_sock {
- struct tfrc_rx_info ccid3hcrx_tfrc;
-#define ccid3hcrx_x_recv ccid3hcrx_tfrc.tfrcrx_x_recv
-#define ccid3hcrx_rtt ccid3hcrx_tfrc.tfrcrx_rtt
-#define ccid3hcrx_p ccid3hcrx_tfrc.tfrcrx_p
- u64 ccid3hcrx_seqno_nonloss:48,
- ccid3hcrx_ccval_nonloss:4,
- ccid3hcrx_ccval_last_counter:4;
- enum ccid3_hc_rx_states ccid3hcrx_state:8;
- u32 ccid3hcrx_bytes_recv;
- struct timeval ccid3hcrx_tstamp_last_feedback;
- struct timeval ccid3hcrx_tstamp_last_ack;
- struct list_head ccid3hcrx_hist;
- struct list_head ccid3hcrx_li_hist;
- u16 ccid3hcrx_s;
- u32 ccid3hcrx_pinv;
- u32 ccid3hcrx_elapsed_time;
+ u8 last_counter:4;
+ enum ccid3_hc_rx_states state:8;
+ u32 bytes_recv;
+ u32 x_recv;
+ u32 rtt;
+ ktime_t tstamp_last_feedback;
+ struct tfrc_rx_hist hist;
+ struct tfrc_loss_hist li_hist;
+ u16 s;
+#define p_inverse li_hist.i_mean
};
-static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk)
-{
- return ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid);
-}
-
static inline struct ccid3_hc_rx_sock *ccid3_hc_rx_sk(const struct sock *sk)
{
- return ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid);
+ 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_ */