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dccp ccid-3: Remove duplicate RX states

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The only state information that the CCID-3 receiver keeps is whether initial 
feedback has been sent or not. Further, this overlaps with use of feedback:

 * state == TFRC_RSTATE_NO_DATA as long as no feedback has been sent;
 * state == TFRC_RSTATE_DATA    as soon as the first feedback has been sent.

This patch reduces the duplication, by memorising the type of the last feedback.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
This commit is contained in:
Gerrit Renker 2008-09-04 07:30:19 +02:00
parent 34a081be8e
commit 2f3e3bbad9
2 changed files with 13 additions and 48 deletions
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47
net/dccp/ccids/ccid3.c
View file

@ -528,40 +528,6 @@ static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len,
/*
* Receiver Half-Connection Routines
*/
/* CCID3 feedback types */
enum ccid3_fback_type {
CCID3_FBACK_NONE = 0,
CCID3_FBACK_INITIAL,
CCID3_FBACK_PERIODIC,
CCID3_FBACK_PARAM_CHANGE
};
#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state)
{
static char *ccid3_rx_state_names[] = {
[TFRC_RSTATE_NO_DATA] = "NO_DATA",
[TFRC_RSTATE_DATA] = "DATA",
};
return ccid3_rx_state_names[state];
}
#endif
static void ccid3_hc_rx_set_state(struct sock *sk,
enum ccid3_hc_rx_states state)
{
struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
enum ccid3_hc_rx_states oldstate = hcrx->state;
ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
dccp_role(sk), sk, ccid3_rx_state_name(oldstate),
ccid3_rx_state_name(state));
WARN_ON(state == oldstate);
hcrx->state = state;
}
static void ccid3_hc_rx_send_feedback(struct sock *sk,
const struct sk_buff *skb,
enum ccid3_fback_type fbtype)
@ -577,7 +543,7 @@ static void ccid3_hc_rx_send_feedback(struct sock *sk,
hcrx->p_inverse = ~0U; /* see RFC 4342, 8.5 */
break;
case CCID3_FBACK_PARAM_CHANGE:
if (unlikely(hcrx->state == TFRC_RSTATE_NO_DATA)) {
if (unlikely(hcrx->feedback == CCID3_FBACK_NONE)) {
/*
* rfc3448bis-06, 6.3.1: First packet(s) lost or marked
* FIXME: in rfc3448bis the receiver returns X_recv=0
@ -626,6 +592,7 @@ static void ccid3_hc_rx_send_feedback(struct sock *sk,
hcrx->tstamp_last_feedback = now;
hcrx->last_counter = dccp_hdr(skb)->dccph_ccval;
hcrx->hist.bytes_recvd = 0;
hcrx->feedback = fbtype;
dp->dccps_hc_rx_insert_options = 1;
dccp_send_ack(sk);
@ -675,7 +642,7 @@ static u32 ccid3_first_li(struct sock *sk)
* to give the equivalent of X_target = s/(2*R). Thus fval = 2 and so p
* is about 20.64%. This yields an interval length of 4.84 (rounded up).
*/
if (unlikely(hcrx->state == TFRC_RSTATE_NO_DATA))
if (unlikely(hcrx->feedback == CCID3_FBACK_NONE))
return 5;
if (hcrx->rtt == 0) {
@ -719,11 +686,9 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
goto done_receiving;
}
if (unlikely(hcrx->state == TFRC_RSTATE_NO_DATA)) {
if (is_data_packet) {
if (unlikely(hcrx->feedback == CCID3_FBACK_NONE)) {
if (is_data_packet)
do_feedback = CCID3_FBACK_INITIAL;
ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA);
}
goto update_records;
}
@ -764,7 +729,6 @@ static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk)
{
struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid);
hcrx->state = TFRC_RSTATE_NO_DATA;
tfrc_lh_init(&hcrx->li_hist);
return tfrc_rx_hist_init(&hcrx->hist, sk);
}
@ -779,7 +743,6 @@ static void ccid3_hc_rx_exit(struct sock *sk)
static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info)
{
info->tcpi_ca_state = ccid3_hc_rx_sk(sk)->state;
info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
info->tcpi_rcv_rtt = ccid3_hc_rx_sk(sk)->rtt;
}

14
net/dccp/ccids/ccid3.h
View file

@ -114,16 +114,18 @@ static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk)
return hctx;
}
/* TFRC receiver states */
enum ccid3_hc_rx_states {
TFRC_RSTATE_NO_DATA = 1,
TFRC_RSTATE_DATA,
enum ccid3_fback_type {
CCID3_FBACK_NONE = 0,
CCID3_FBACK_INITIAL,
CCID3_FBACK_PERIODIC,
CCID3_FBACK_PARAM_CHANGE
};
/** struct ccid3_hc_rx_sock - CCID3 receiver half-connection socket
*
* @last_counter - Tracks window counter (RFC 4342, 8.1)
* @state - Receiver state, one of %ccid3_hc_rx_states
* @feedback - The type of the feedback last sent
* @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
@ -133,7 +135,7 @@ enum ccid3_hc_rx_states {
*/
struct ccid3_hc_rx_sock {
u8 last_counter:4;
enum ccid3_hc_rx_states state:8;
enum ccid3_fback_type feedback:4;
u32 x_recv;
u32 rtt;
ktime_t tstamp_last_feedback;