2007/9/20, Tommi Saviranta <wnd@xxxxxx>: > (Yup, it is less than 40 KiB.) > > > Signed-off-by: Tommi Saviranta <wnd@xxxxxx> > > --- > diff --git a/net/dccp/ccids/ccid4.c b/net/dccp/ccids/ccid4.c > new file mode 100644 > index 0000000..7610c6e > --- /dev/null > +++ b/net/dccp/ccids/ccid4.c > @@ -0,0 +1,984 @@ > +/* > + * net/dccp/ccids/ccid4.c > + * > + * 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@xxxxxxxxxxx> > + * > + * An implementation of the DCCP protocol > + * > + * This code has been developed by the University of Waikato WAND > + * research group. For further information please see http://www.wand.net.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 ccid4 draft > + * and to make it work as a loadable module in the DCCP stack written by > + * Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxx>. > + * > + * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxx> > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program; if not, write to the Free Software > + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. > + */ > +#include "../dccp.h" > +#include "ccid4.h" > + > +#ifdef CONFIG_IP_DCCP_CCID4_DEBUG > +static int ccid4_debug; > +#define ccid4_pr_debug(format, a...) DCCP_PR_DEBUG(ccid4_debug, format, ##a) > +#else > +#define ccid4_pr_debug(format, a...) > +#endif > + > +DECLARE_TFRC_TX_CACHE(ccid4_tx_hist); > + > +/* > + * Transmitter Half-Connection Routines > + */ > +#ifdef CONFIG_IP_DCCP_CCID4_DEBUG > +static const char *ccid4_tx_state_name(enum ccid4_hc_tx_states state) > +{ > + static char *ccid4_state_names[] = { > + [TFRC_SSTATE_NO_SENT] = "NO_SENT", > + [TFRC_SSTATE_NO_FBACK] = "NO_FBACK", > + [TFRC_SSTATE_FBACK] = "FBACK", > + [TFRC_SSTATE_TERM] = "TERM", > + }; > + > + return ccid4_state_names[state]; > +} > +#endif > + > +static void ccid4_hc_tx_set_state(struct sock *sk, > + enum ccid4_hc_tx_states state) > +{ > + struct ccid4_hc_tx_sock *hctx = ccid4_hc_tx_sk(sk); > + enum ccid4_hc_tx_states oldstate = hctx->ccid4hctx_state; > + > + ccid4_pr_debug("%s(%p) %-8.8s -> %s\n", > + dccp_role(sk), sk, ccid4_tx_state_name(oldstate), > + ccid4_tx_state_name(state)); > + WARN_ON(state == oldstate); > + hctx->ccid4hctx_state = state; > +} > + > +/* > + * Compute the initial sending rate X_init in the manner of RFC 3390: > + * > + * X_init = min(4 * s, max(2 * s, 4380 bytes)) / RTT > + * > + * Note that RFC 3390 uses MSS, RFC 4342 refers to RFC 3390, and rfc3448bis > + * (rev-02) clarifies the use of RFC 3390 with regard to the above formula. > + * For consistency with other parts of the code, X_init is scaled by 2^6. > + */ > +static inline u64 rfc3390_initial_rate(struct sock *sk) > +{ > + const struct ccid4_hc_tx_sock *hctx = ccid4_hc_tx_sk(sk); > + const __u32 w_init = min_t(__u32, 4 * hctx->ccid4hctx_s, > + max_t(__u32, 2 * hctx->ccid4hctx_s, 4380)); > + > + return scaled_div(w_init << 6, hctx->ccid4hctx_rtt); > +} > + > +/* > + * Recalculate t_ipi and delta (should be called whenever X changes) > + */ > +static inline void ccid4_update_send_interval(struct ccid4_hc_tx_sock *hctx) > +{ > + /* Calculate new t_ipi = s / X_inst (X_inst is in 64 * bytes/second) */ > + hctx->ccid4hctx_t_ipi = scaled_div32(((u64)hctx->ccid4hctx_s) << 6, > + hctx->ccid4hctx_x); > + > + /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */ > + hctx->ccid4hctx_delta = min_t(u32, hctx->ccid4hctx_t_ipi / 2, > + TFRC_OPSYS_HALF_TIME_GRAN); > + > + ccid4_pr_debug("t_ipi=%u, delta=%u, s=%u, X=%u\n", > + hctx->ccid4hctx_t_ipi, hctx->ccid4hctx_delta, > + hctx->ccid4hctx_s, (unsigned)(hctx->ccid4hctx_x >> 6)); > + > +} > + > +static u32 ccid4_hc_tx_idle_rtt(struct ccid4_hc_tx_sock *hctx, ktime_t now) > +{ > + u32 delta = ktime_us_delta(now, hctx->ccid4hctx_t_last_win_count); > + > + return delta/hctx->ccid4hctx_rtt; > +} > + > +/** > + * ccid4_hc_tx_update_x - Update allowed sending rate X > + * @stamp: most recent time if available - can be left NULL. > + * This function tracks draft rfc3448bis, check there for latest details. > + * > + * Note: X and X_recv are both stored in units of 64 * bytes/second, to support > + * fine-grained resolution of sending rates. This requires scaling by 2^6 > + * throughout the code. Only X_calc is unscaled (in bytes/second). > + * > + */ > +static void ccid4_hc_tx_update_x(struct sock *sk, ktime_t *stamp) > + > +{ > + struct ccid4_hc_tx_sock *hctx = ccid4_hc_tx_sk(sk); > + __u64 min_rate = 2 * hctx->ccid4hctx_x_recv; > + const __u64 old_x = hctx->ccid4hctx_x; > + ktime_t now = stamp? *stamp : ktime_get_real(); > + > + /* > + * Handle IDLE periods: do not reduce below RFC3390 initial sending rate > + * when idling [RFC 4342, 5.1]. Definition of idling is from rfc3448bis: > + * a sender is idle if it has not sent anything over a 2-RTT-period. > + * For consistency with X and X_recv, min_rate is also scaled by 2^6. > + */ > + if (ccid4_hc_tx_idle_rtt(hctx, now) >= 2) { > + min_rate = rfc3390_initial_rate(sk); > + min_rate = max(min_rate, 2 * hctx->ccid4hctx_x_recv); > + } > + > + if (hctx->ccid4hctx_p > 0) { > + > + hctx->ccid4hctx_x = min(((__u64)hctx->ccid4hctx_x_calc) << 6, > + min_rate); > + hctx->ccid4hctx_x = max(hctx->ccid4hctx_x, > + (((__u64)hctx->ccid4hctx_s) << 6) / > + TFRC_T_MBI); > + > + } else if (ktime_us_delta(now, hctx->ccid4hctx_t_ld) > + - (s64)hctx->ccid4hctx_rtt >= 0) { > + > + hctx->ccid4hctx_x = > + max(min(2 * hctx->ccid4hctx_x, min_rate), > + scaled_div(((__u64)hctx->ccid4hctx_s) << 6, > + hctx->ccid4hctx_rtt)); > + hctx->ccid4hctx_t_ld = now; > + } > + > + if (hctx->ccid4hctx_x != old_x) { > + ccid4_pr_debug("X_prev=%u, X_now=%u, X_calc=%u, " > + "X_recv=%u\n", (unsigned)(old_x >> 6), > + (unsigned)(hctx->ccid4hctx_x >> 6), > + hctx->ccid4hctx_x_calc, > + (unsigned)(hctx->ccid4hctx_x_recv >> 6)); > + > + ccid4_update_send_interval(hctx); > + } > +} > + > +/* > + * Track the mean packet size `s' (cf. RFC 4342, 5.3 and RFC 3448, 4.1) > + * @len: DCCP packet payload size in bytes > + */ > +static inline void ccid4_hc_tx_update_s(struct ccid4_hc_tx_sock *hctx, int len) > +{ > + const u16 old_s = hctx->ccid4hctx_s; > + > + hctx->ccid4hctx_s = tfrc_ewma(hctx->ccid4hctx_s, len, 9); > + > + if (hctx->ccid4hctx_s != old_s) > + ccid4_update_send_interval(hctx); > +} > + > +/* > + * Update Window Counter using the algorithm from [RFC 4342, 8.1]. > + * The algorithm is not applicable if RTT < 4 microseconds. > + */ > +static inline void ccid4_hc_tx_update_win_count(struct ccid4_hc_tx_sock *hctx, > + ktime_t now) > +{ > + u32 quarter_rtts; > + > + if (unlikely(hctx->ccid4hctx_rtt < 4)) /* avoid divide-by-zero */ > + return; > + > + quarter_rtts = ktime_us_delta(now, hctx->ccid4hctx_t_last_win_count); > + quarter_rtts /= hctx->ccid4hctx_rtt / 4; > + > + if (quarter_rtts > 0) { > + hctx->ccid4hctx_t_last_win_count = now; > + hctx->ccid4hctx_last_win_count += min_t(u32, quarter_rtts, 5); > + hctx->ccid4hctx_last_win_count &= 0xF; /* mod 16 */ > + } > +} > + > +static void ccid4_hc_tx_no_feedback_timer(unsigned long data) > +{ > + struct sock *sk = (struct sock *)data; > + struct ccid4_hc_tx_sock *hctx = ccid4_hc_tx_sk(sk); > + unsigned long t_nfb = USEC_PER_SEC / 5; > + > + bh_lock_sock(sk); > + if (sock_owned_by_user(sk)) { > + /* Try again later. */ > + /* XXX: set some sensible MIB */ > + goto restart_timer; > + } > + > + ccid4_pr_debug("%s(%p, state=%s) - entry \n", dccp_role(sk), sk, > + ccid4_tx_state_name(hctx->ccid4hctx_state)); > + > + if (hctx->ccid4hctx_state == TFRC_SSTATE_FBACK) > + ccid4_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); > + else if (hctx->ccid4hctx_state != TFRC_SSTATE_NO_FBACK) > + goto out; > + > + /* > + * Determine new allowed sending rate X as per draft rfc3448bis, 4.4 > + */ > + if (hctx->ccid4hctx_t_rto == 0 || /* no feedback received yet */ > + hctx->ccid4hctx_p == 0 ) { > + > + /* halve send rate directly */ > + hctx->ccid4hctx_x = max(hctx->ccid4hctx_x / 2, > + (((__u64)hctx->ccid4hctx_s) << 6) / > + TFRC_T_MBI); > + ccid4_update_send_interval(hctx); > + } else { > + /* > + * Modify the cached value of X_recv > + * > + * If (X_calc > 2 * X_recv) > + * X_recv = max(X_recv / 2, s / (2 * t_mbi)); > + * Else > + * X_recv = X_calc / 4; > + * > + * Note that X_recv is scaled by 2^6 while X_calc is not > + */ > + BUG_ON(hctx->ccid4hctx_p && !hctx->ccid4hctx_x_calc); > + > + if (hctx->ccid4hctx_x_calc > (hctx->ccid4hctx_x_recv >> 5)) > + hctx->ccid4hctx_x_recv = > + max(hctx->ccid4hctx_x_recv / 2, > + (((__u64)hctx->ccid4hctx_s) << 6) / > + (2 * TFRC_T_MBI)); > + else { > + hctx->ccid4hctx_x_recv = hctx->ccid4hctx_x_calc; > + hctx->ccid4hctx_x_recv <<= 4; > + } > + ccid4_hc_tx_update_x(sk, NULL); > + } > + ccid4_pr_debug("Reduced X to %llu/64 bytes/sec\n", > + (unsigned long long)hctx->ccid4hctx_x); > + > + /* > + * Set new timeout for the nofeedback timer. > + * See comments in packet_recv() regarding the value of t_RTO. > + */ > + if (unlikely(hctx->ccid4hctx_t_rto == 0)) /* no feedback yet */ > + t_nfb = TFRC_INITIAL_TIMEOUT; > + else > + t_nfb = max(hctx->ccid4hctx_t_rto, 2 * hctx->ccid4hctx_t_ipi); > + > +restart_timer: > + sk_reset_timer(sk, &hctx->ccid4hctx_no_feedback_timer, > + jiffies + usecs_to_jiffies(t_nfb)); > +out: > + bh_unlock_sock(sk); > + sock_put(sk); > +} > + > +/* > + * returns > + * > 0: delay (in msecs) that should pass before actually sending > + * = 0: can send immediately > + * < 0: error condition; do not send packet > + */ > +static int ccid4_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) > +{ > + struct dccp_sock *dp = dccp_sk(sk); > + struct ccid4_hc_tx_sock *hctx = ccid4_hc_tx_sk(sk); > + ktime_t now = ktime_get_real(); > + s64 delay; > + > + /* > + * This function is called only for Data and DataAck packets. Sending > + * zero-sized Data(Ack)s is theoretically possible, but for congestion > + * control this case is pathological - ignore it. > + */ > + if (unlikely(skb->len == 0)) > + return -EBADMSG; > + > + switch (hctx->ccid4hctx_state) { > + case TFRC_SSTATE_NO_SENT: > + sk_reset_timer(sk, &hctx->ccid4hctx_no_feedback_timer, > + (jiffies + > + usecs_to_jiffies(TFRC_INITIAL_TIMEOUT))); > + hctx->ccid4hctx_last_win_count = 0; > + hctx->ccid4hctx_t_last_win_count = now; > + > + /* Set t_0 for initial packet */ > + hctx->ccid4hctx_t_nom = now; > + > + hctx->ccid4hctx_s = skb->len; > + > + /* > + * Use initial RTT sample when available: recommended by erratum > + * to RFC 4342. This implements the initialisation procedure of > + * draft rfc3448bis, section 4.2. Remember, X is scaled by 2^6. > + */ > + if (dp->dccps_syn_rtt) { > + ccid4_pr_debug("SYN RTT = %uus\n", dp->dccps_syn_rtt); > + hctx->ccid4hctx_rtt = dp->dccps_syn_rtt; > + hctx->ccid4hctx_x = rfc3390_initial_rate(sk); > + hctx->ccid4hctx_t_ld = now; > + } else { > + /* Sender does not have RTT sample: X_pps = 1 pkt/sec */ > + hctx->ccid4hctx_x = hctx->ccid4hctx_s; > + hctx->ccid4hctx_x <<= 6; > + } > + ccid4_update_send_interval(hctx); > + > + ccid4_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); > + break; > + case TFRC_SSTATE_NO_FBACK: > + case TFRC_SSTATE_FBACK: > + delay = ktime_us_delta(hctx->ccid4hctx_t_nom, now); > + ccid4_pr_debug("delay=%ld\n", (long)delay); > + /* > + * Scheduling of packet transmissions [RFC 3448, 4.6] > + * > + * if (t_now > t_nom - delta) > + * // send the packet now > + * else > + * // send the packet in (t_nom - t_now) milliseconds. > + */ > + if (delay - (s64)hctx->ccid4hctx_delta >= 1000) > + return (u32)delay / 1000L; > + > + ccid4_hc_tx_update_win_count(hctx, now); > + break; > + case TFRC_SSTATE_TERM: > + DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk); > + return -EINVAL; > + } > + > + /* prepare to send now (add options etc.) */ > + dp->dccps_hc_tx_insert_options = 1; > + DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid4hctx_last_win_count; > + > + /* set the nominal send time for the next following packet */ > + hctx->ccid4hctx_t_nom = ktime_add_us(hctx->ccid4hctx_t_nom, > + hctx->ccid4hctx_t_ipi); > + return 0; > +} > + > +static void ccid4_hc_tx_packet_sent(struct sock *sk, int more, > + unsigned int len) > +{ > + struct ccid4_hc_tx_sock *hctx = ccid4_hc_tx_sk(sk); > + > + ccid4_hc_tx_update_s(hctx, len); > + > + if (tfrc_tx_hist_add(&hctx->ccid4hctx_hist, dccp_sk(sk)->dccps_gss)) > + DCCP_CRIT("packet history - out of memory!"); > +} > + > +static void ccid4_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) > +{ > + struct ccid4_hc_tx_sock *hctx = ccid4_hc_tx_sk(sk); > + struct ccid4_options_received *opt_recv; > + ktime_t t_send, now; > + unsigned long t_nfb; > + u32 pinv, r_sample; > + > + /* we are only interested in ACKs */ > + if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK || > + DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK)) > + return; > + > + /* ... and only in the established state */ > + switch (hctx->ccid4hctx_state) { > + case TFRC_SSTATE_NO_FBACK: /* fall through */ > + case TFRC_SSTATE_FBACK: break; > + default: return; > + } > + > + /* estimate RTT from history if ACK number is valid */ > + if (! tfrc_tx_hist_when(&t_send, &hctx->ccid4hctx_hist, > + DCCP_SKB_CB(skb)->dccpd_ack_seq)) { > + DCCP_WARN("%s(%p): %s with bogus ACK-%llu\n", dccp_role(sk), sk, > + dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type), > + (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq); > + return; > + } > + > + opt_recv = &hctx->ccid4hctx_options_received; > + > + /* Update receive rate in units of 64 * bytes/second */ > + hctx->ccid4hctx_x_recv = opt_recv->ccid4or_receive_rate; > + hctx->ccid4hctx_x_recv <<= 6; > + > + /* Update loss event rate (scaled by 1e6), cf. RFC 4342, 8.5 */ > + pinv = opt_recv->ccid4or_loss_event_rate; > + hctx->ccid4hctx_p = (pinv == ~0U || pinv == 0)? 0 : scaled_div(1, pinv); > + > + /* > + * Calculate new RTT sample and update moving average > + */ > + now = ktime_get_real(); > + r_sample = dccp_sample_rtt(sk, ktime_us_delta(now, t_send)); > + hctx->ccid4hctx_rtt = tfrc_ewma(hctx->ccid4hctx_rtt, r_sample, 9); > + > + /* > + * Update allowed sending rate X as per draft rfc3448bis, 4.2/4.3 > + */ > + if (hctx->ccid4hctx_state == TFRC_SSTATE_NO_FBACK) { > + > + ccid4_hc_tx_set_state(sk, TFRC_SSTATE_FBACK); > + > + if (hctx->ccid4hctx_t_rto == 0) { > + /* > + * Initial feedback packet: Larger Initial Windows (4.2) > + */ > + hctx->ccid4hctx_x = rfc3390_initial_rate(sk); > + hctx->ccid4hctx_t_ld = now; > + > + ccid4_update_send_interval(hctx); > + > + goto done_computing_x; > + > + } else if (hctx->ccid4hctx_p == 0) { > + /* > + * First feedback after nofeedback timer expiry (4.3) > + */ > + goto done_computing_x; > + } > + } > + /* perform step (4) of draft rfc3448bis, section 4.3 */ > + if (hctx->ccid4hctx_p > 0) > + hctx->ccid4hctx_x_calc = tfrc_calc_x(hctx->ccid4hctx_s, > + hctx->ccid4hctx_rtt, > + hctx->ccid4hctx_p); > + ccid4_hc_tx_update_x(sk, &now); > + > +done_computing_x: > + ccid4_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, p=%u, X_calc=%u, " > + "X_recv=%u, X=%u\n", dccp_role(sk), sk, > + hctx->ccid4hctx_rtt, r_sample, hctx->ccid4hctx_s, > + hctx->ccid4hctx_p, hctx->ccid4hctx_x_calc, > + (unsigned)(hctx->ccid4hctx_x_recv >> 6), > + (unsigned)(hctx->ccid4hctx_x >> 6)); > + > + /* unschedule no feedback timer */ > + sk_stop_timer(sk, &hctx->ccid4hctx_no_feedback_timer); > + > + /* > + * As we have calculated new ipi, delta, t_nom it is possible > + * that we now can send a packet, so wake up dccp_wait_for_ccid > + */ > + sk->sk_write_space(sk); > + > + /* > + * Update timeout interval for the nofeedback timer. > + * We use a configuration option to increase the lower bound. > + * This can help avoid triggering the nofeedback timer too > + * often ('spinning') on LANs with small RTTs. > + */ > + hctx->ccid4hctx_t_rto = max_t(u32, 4 * hctx->ccid4hctx_rtt, > + CONFIG_IP_DCCP_CCID4_RTO * > + (USEC_PER_SEC/1000)); > + /* > + * Schedule no feedback timer to expire in > + * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi) > + */ > + t_nfb = max(hctx->ccid4hctx_t_rto, 2 * hctx->ccid4hctx_t_ipi); > + > + sk_reset_timer(sk, &hctx->ccid4hctx_no_feedback_timer, > + jiffies + usecs_to_jiffies(t_nfb)); > + > + ccid4_pr_debug("Scheduled no feedback timer to expire in %lu jiffies" > + "(%luus)\n", usecs_to_jiffies(t_nfb), t_nfb); > +} > + > +static int ccid4_hc_tx_parse_options(struct sock *sk, unsigned char option, > + unsigned char len, u16 idx, > + unsigned char *value) > +{ > + int rc = 0; > + const struct dccp_sock *dp = dccp_sk(sk); > + struct ccid4_hc_tx_sock *hctx = ccid4_hc_tx_sk(sk); > + struct ccid4_options_received *opt_recv; > + u32 opt_val; > + > + opt_recv = &hctx->ccid4hctx_options_received; > + > + if (opt_recv->ccid4or_seqno != dp->dccps_gsr) { > + opt_recv->ccid4or_seqno = dp->dccps_gsr; > + opt_recv->ccid4or_loss_event_rate = ~0; > + opt_recv->ccid4or_loss_intervals_idx = 0; > + opt_recv->ccid4or_loss_intervals_len = 0; > + opt_recv->ccid4or_receive_rate = 0; > + } > + > + switch (option) { > + case TFRC_OPT_LOSS_EVENT_RATE: > + if (unlikely(len != 4)) { > + DCCP_WARN("%s(%p), invalid len %d " > + "for TFRC_OPT_LOSS_EVENT_RATE\n", > + dccp_role(sk), sk, len); > + rc = -EINVAL; > + } else { > + opt_val = get_unaligned((u32 *)value); > + opt_recv->ccid4or_loss_event_rate = ntohl(opt_val); > + ccid4_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n", > + dccp_role(sk), sk, > + opt_recv->ccid4or_loss_event_rate); > + } > + break; > + case TFRC_OPT_LOSS_INTERVALS: > + opt_recv->ccid4or_loss_intervals_idx = idx; > + opt_recv->ccid4or_loss_intervals_len = len; > + ccid4_pr_debug("%s(%p), LOSS_INTERVALS=(%u, %u)\n", > + dccp_role(sk), sk, > + opt_recv->ccid4or_loss_intervals_idx, > + opt_recv->ccid4or_loss_intervals_len); > + break; > + case TFRC_OPT_RECEIVE_RATE: > + if (unlikely(len != 4)) { > + DCCP_WARN("%s(%p), invalid len %d " > + "for TFRC_OPT_RECEIVE_RATE\n", > + dccp_role(sk), sk, len); > + rc = -EINVAL; > + } else { > + opt_val = get_unaligned((u32 *)value); > + opt_recv->ccid4or_receive_rate = ntohl(opt_val); > + ccid4_pr_debug("%s(%p), RECEIVE_RATE=%u\n", > + dccp_role(sk), sk, > + opt_recv->ccid4or_receive_rate); > + } > + break; > + } > + > + return rc; > +} > + > +static int ccid4_hc_tx_init(struct ccid *ccid, struct sock *sk) > +{ > + struct ccid4_hc_tx_sock *hctx = ccid_priv(ccid); > + > + hctx->ccid4hctx_state = TFRC_SSTATE_NO_SENT; > + tfrc_tx_hist_init(&hctx->ccid4hctx_hist, ccid4_tx_hist); > + > + hctx->ccid4hctx_no_feedback_timer.function = > + ccid4_hc_tx_no_feedback_timer; > + hctx->ccid4hctx_no_feedback_timer.data = (unsigned long)sk; > + init_timer(&hctx->ccid4hctx_no_feedback_timer); > + > + return 0; > +} > + > +static void ccid4_hc_tx_exit(struct sock *sk) > +{ > + struct ccid4_hc_tx_sock *hctx = ccid4_hc_tx_sk(sk); > + > + ccid4_hc_tx_set_state(sk, TFRC_SSTATE_TERM); > + sk_stop_timer(sk, &hctx->ccid4hctx_no_feedback_timer); > + > + /* Empty packet history */ > + tfrc_tx_hist_cleanup(&hctx->ccid4hctx_hist); > +} > + > +static void ccid4_hc_tx_get_info(struct sock *sk, struct tcp_info *info) > +{ > + const struct ccid4_hc_tx_sock *hctx = ccid4_hc_tx_sk(sk); > + > + /* Listen socks doesn't have a private CCID block */ > + if (sk->sk_state == DCCP_LISTEN) > + return; > + > + info->tcpi_rto = hctx->ccid4hctx_t_rto; > + info->tcpi_rtt = hctx->ccid4hctx_rtt; > +} > + > +static int ccid4_hc_tx_getsockopt(struct sock *sk, const int optname, int len, > + u32 __user *optval, int __user *optlen) > +{ > + const struct ccid4_hc_tx_sock *hctx = ccid4_hc_tx_sk(sk); > + const void *val; > + > + /* Listen socks doesn't have a private CCID block */ > + if (sk->sk_state == DCCP_LISTEN) > + return -EINVAL; > + > + switch (optname) { > + case DCCP_SOCKOPT_CCID_TX_INFO: > + if (len < sizeof(hctx->ccid4hctx_tfrc)) > + return -EINVAL; > + len = sizeof(hctx->ccid4hctx_tfrc); > + val = &hctx->ccid4hctx_tfrc; > + break; > + default: > + return -ENOPROTOOPT; > + } > + > + if (put_user(len, optlen) || copy_to_user(optval, val, len)) > + return -EFAULT; > + > + return 0; > +} > + > +/* > + * Receiver Half-Connection Routines > + */ > +#ifdef CONFIG_IP_DCCP_CCID4_DEBUG > +static const char *ccid4_rx_state_name(enum ccid4_hc_rx_states state) > +{ > + static char *ccid4_rx_state_names[] = { > + [TFRC_RSTATE_NO_DATA] = "NO_DATA", > + [TFRC_RSTATE_DATA] = "DATA", > + [TFRC_RSTATE_TERM] = "TERM", > + }; > + > + return ccid4_rx_state_names[state]; > +} > +#endif > + > +static void ccid4_hc_rx_set_state(struct sock *sk, > + enum ccid4_hc_rx_states state) > +{ > + struct ccid4_hc_rx_sock *hcrx = ccid4_hc_rx_sk(sk); > + enum ccid4_hc_rx_states oldstate = hcrx->ccid4hcrx_state; > + > + ccid4_pr_debug("%s(%p) %-8.8s -> %s\n", > + dccp_role(sk), sk, ccid4_rx_state_name(oldstate), > + ccid4_rx_state_name(state)); > + WARN_ON(state == oldstate); > + hcrx->ccid4hcrx_state = state; > +} > + > +static inline void ccid4_hc_rx_update_s(struct ccid4_hc_rx_sock *hcrx, int len) > +{ > + if (likely(len > 0)) /* don't update on empty packets (e.g. ACKs) */ > + hcrx->ccid4hcrx_s = tfrc_ewma(hcrx->ccid4hcrx_s, len, 9); > +} > + > +static void ccid4_hc_rx_send_feedback(struct sock *sk, struct sk_buff *skb, > + enum ccid4_fback_type fbtype) > +{ > + struct ccid4_hc_rx_sock *hcrx = ccid4_hc_rx_sk(sk); > + struct dccp_sock *dp = dccp_sk(sk); > + ktime_t now = ktime_get_real(); > + s64 delta = 0; > + > + if (unlikely(hcrx->ccid4hcrx_state == TFRC_RSTATE_TERM)) > + return; > + > + switch (fbtype) { > + case FBACK_INITIAL: > + hcrx->ccid4hcrx_x_recv = 0; > + hcrx->ccid4hcrx_pinv = ~0U; /* see RFC 4342, 8.5 */ > + break; > + case FBACK_PARAM_CHANGE: > + /* > + * When parameters change (new loss or p > p_prev), we do not > + * have a reliable estimate for R_m of [RFC 3448, 6.2] and so > + * need to reuse the previous value of X_recv. However, when > + * X_recv was 0 (due to early loss), this would kill X down to > + * s/t_mbi (i.e. one packet in 64 seconds). > + * To avoid such drastic reduction, we approximate X_recv as > + * the number of bytes since last feedback. > + * This is a safe fallback, since X is bounded above by X_calc. > + */ > + if (hcrx->ccid4hcrx_x_recv > 0) > + break; > + /* fall through */ > + case FBACK_PERIODIC: > + delta = ktime_us_delta(now, hcrx->ccid4hcrx_last_feedback); > + if (delta <= 0) > + DCCP_BUG("delta (%ld) <= 0", (long)delta); > + else > + hcrx->ccid4hcrx_x_recv = > + scaled_div32(hcrx->ccid4hcrx_bytes_recv, delta); > + break; > + default: > + return; > + } > + ccid4_pr_debug("Interval %ldusec, X_recv=%u, 1/p=%u\n", (long)delta, > + hcrx->ccid4hcrx_x_recv, hcrx->ccid4hcrx_pinv); > + > + hcrx->ccid4hcrx_last_feedback = now; > + hcrx->ccid4hcrx_last_counter = dccp_hdr(skb)->dccph_ccval; > + hcrx->ccid4hcrx_bytes_recv = 0; > + > + dp->dccps_hc_rx_insert_options = 1; > + dccp_send_ack(sk); > +} > + > +static int ccid4_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb) > +{ > + const struct ccid4_hc_rx_sock *hcrx = ccid4_hc_rx_sk(sk); > + __be32 x_recv, pinv; > + > + if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN)) > + return 0; > + > + if (dccp_packet_without_ack(skb)) > + return 0; > + > + x_recv = htonl(hcrx->ccid4hcrx_x_recv); > + pinv = htonl(hcrx->ccid4hcrx_pinv); > + > + if (dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE, > + &pinv, sizeof(pinv)) || > + dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE, > + &x_recv, sizeof(x_recv))) > + return -1; > + > + return 0; > +} > + > +/** ccid4_first_li - Implements [RFC 3448, 6.3.1] > + * > + * 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 (scaled). > + */ > +static u32 ccid4_first_li(struct sock *sk) > +{ > + struct ccid4_hc_rx_sock *hcrx = ccid4_hc_rx_sk(sk); > + u32 x_recv, p, delta; > + u64 fval; > + > + if (hcrx->ccid4hcrx_rtt == 0) { > + DCCP_WARN("No RTT estimate available, using fallback RTT\n"); > + hcrx->ccid4hcrx_rtt = DCCP_FALLBACK_RTT; > + } > + > + delta = ktime_to_us(net_timedelta(hcrx->ccid4hcrx_last_feedback)); > + x_recv = scaled_div32(hcrx->ccid4hcrx_bytes_recv, delta); > + if (x_recv == 0) { /* would also trigger divide-by-zero */ > + DCCP_WARN("X_recv==0\n"); > + if ((x_recv = hcrx->ccid4hcrx_x_recv) == 0) { > + DCCP_BUG("stored value of X_recv is zero"); > + return ~0U; > + } > + } > + > + fval = scaled_div(hcrx->ccid4hcrx_s, hcrx->ccid4hcrx_rtt); > + fval = scaled_div32(fval, x_recv); > + p = tfrc_calc_x_reverse_lookup(fval); > + > + ccid4_pr_debug("%s(%p), receive rate=%u bytes/s, implied " > + "loss rate=%u\n", dccp_role(sk), sk, x_recv, p); > + > + return p == 0? ~0U : scaled_div(1, p); > +} > + > +static void ccid4_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) > +{ > + struct ccid4_hc_rx_sock *hcrx = ccid4_hc_rx_sk(sk); > + enum ccid4_fback_type do_feedback = FBACK_NONE; > + u32 sample, ndp = dccp_sk(sk)->dccps_options_received.dccpor_ndp, > + payload_size = skb->len - dccp_hdr(skb)->dccph_doff * 4; > + u8 is_data_packet = dccp_data_packet(skb); > + > + spin_lock(&hcrx->ccid4hcrx_hist.lock); > + > + if (unlikely(hcrx->ccid4hcrx_state == TFRC_RSTATE_NO_DATA)) { > + if (is_data_packet) { > + do_feedback = FBACK_INITIAL; > + ccid4_hc_rx_set_state(sk, TFRC_RSTATE_DATA); > + ccid4_hc_rx_update_s(hcrx, payload_size); > + } > + goto update_records; > + } > + > + if (tfrc_rx_duplicate(&hcrx->ccid4hcrx_hist, skb)) > + goto done_receiving; > + > + if (is_data_packet) { > + ccid4_hc_rx_update_s(hcrx, payload_size); > + hcrx->ccid4hcrx_bytes_recv += payload_size; > + } > + > + /* > + * Handle pending losses and otherwise check for new loss > + */ > + if (tfrc_rx_loss_pending(&hcrx->ccid4hcrx_hist) && > + tfrc_rx_handle_loss(&hcrx->ccid4hcrx_hist, > + &hcrx->ccid4hcrx_li_hist, > + skb, ndp, ccid4_first_li, sk) ) { > + do_feedback = FBACK_PARAM_CHANGE; > + goto done_receiving; > + } > + > + if (tfrc_rx_new_loss_indicated(&hcrx->ccid4hcrx_hist, skb, ndp)) > + goto update_records; > + > + /* > + * Handle data packets: RTT sampling and monitoring p > + */ > + if (unlikely(!is_data_packet)) > + goto update_records; > + > + if (! tfrc_lh_is_initialised(&hcrx->ccid4hcrx_li_hist)) { > + /* > + * Empty loss history: no loss so far, hence p stays 0. > + * Sample RTT values, since an RTT estimate is required for the > + * computation of p when the first loss occurs; RFC 3448, 6.3.1. > + */ > + sample = tfrc_rx_sample_rtt(&hcrx->ccid4hcrx_hist, skb); > + if (sample != 0) > + hcrx->ccid4hcrx_rtt = > + tfrc_ewma(hcrx->ccid4hcrx_rtt, sample, 9); > + > + } else if (tfrc_lh_update_i_mean(&hcrx->ccid4hcrx_li_hist, skb)) > + /* > + * Step (3) of [RFC 3448, 6.1]: Recompute I_mean and, if I_mean > + * has decreased (resp. p has increased), send feedback now. > + */ > + do_feedback = FBACK_PARAM_CHANGE; > + > + /* check if the periodic once-per-RTT feedback is due; RFC 4342, 10.3 */ > + if (SUB16(dccp_hdr(skb)->dccph_ccval, hcrx->ccid4hcrx_last_counter) > 3) > + do_feedback = FBACK_PERIODIC; > + > +update_records: > + tfrc_rx_hist_update(&hcrx->ccid4hcrx_hist, skb, ndp); > + > +done_receiving: > + spin_unlock(&hcrx->ccid4hcrx_hist.lock); > + > + if (do_feedback) > + ccid4_hc_rx_send_feedback(sk, skb, do_feedback); > +} > + > +static int ccid4_hc_rx_init(struct ccid *ccid, struct sock *sk) > +{ > + struct ccid4_hc_rx_sock *hcrx = ccid_priv(ccid); > + > + ccid4_pr_debug("entry\n"); > + > + tfrc_lh_init(&hcrx->ccid4hcrx_li_hist); > + hcrx->ccid4hcrx_state = TFRC_RSTATE_NO_DATA; > + > + return tfrc_rx_hist_init(&hcrx->ccid4hcrx_hist); > +} > + > +static void ccid4_hc_rx_exit(struct sock *sk) > +{ > + struct ccid4_hc_rx_sock *hcrx = ccid4_hc_rx_sk(sk); > + > + ccid4_hc_rx_set_state(sk, TFRC_RSTATE_TERM); > + > + tfrc_rx_hist_cleanup(&hcrx->ccid4hcrx_hist); > + tfrc_lh_cleanup(&hcrx->ccid4hcrx_li_hist); > +} > + > +static void ccid4_hc_rx_get_info(struct sock *sk, struct tcp_info *info) > +{ > + const struct ccid4_hc_rx_sock *hcrx = ccid4_hc_rx_sk(sk); > + > + /* Listen socks doesn't have a private CCID block */ > + if (sk->sk_state == DCCP_LISTEN) > + return; > + > + info->tcpi_ca_state = hcrx->ccid4hcrx_state; > + info->tcpi_options |= TCPI_OPT_TIMESTAMPS; > + info->tcpi_rcv_rtt = hcrx->ccid4hcrx_rtt; > +} > + > +static int ccid4_hc_rx_getsockopt(struct sock *sk, const int optname, int len, > + u32 __user *optval, int __user *optlen) > +{ > + const struct ccid4_hc_rx_sock *hcrx = ccid4_hc_rx_sk(sk); > + const void *val; > + struct tfrc_rx_info rx_info; > + > + /* Listen socks don't have a private CCID block */ > + if (sk->sk_state == DCCP_LISTEN) > + return -EINVAL; > + > + switch (optname) { > + case DCCP_SOCKOPT_CCID_RX_INFO: > + if (len < sizeof(rx_info)) > + return -EINVAL; > + len = sizeof(rx_info); > + val = &rx_info; > + rx_info.tfrcrx_x_recv = hcrx->ccid4hcrx_x_recv; > + rx_info.tfrcrx_rtt = hcrx->ccid4hcrx_rtt; > + rx_info.tfrcrx_p = hcrx->ccid4hcrx_pinv == 0? ~0U > + : scaled_div(1, hcrx->ccid4hcrx_pinv); > + break; > + default: > + return -ENOPROTOOPT; > + } > + > + if (put_user(len, optlen) || copy_to_user(optval, val, len)) > + return -EFAULT; > + > + return 0; > +} > + > +static struct ccid_operations ccid4 = { > + .ccid_id = DCCPC_CCID4, > + .ccid_name = "ccid4", > + .ccid_owner = THIS_MODULE, > + .ccid_hc_tx_obj_size = sizeof(struct ccid4_hc_tx_sock), > + .ccid_hc_tx_init = ccid4_hc_tx_init, > + .ccid_hc_tx_exit = ccid4_hc_tx_exit, > + .ccid_hc_tx_send_packet = ccid4_hc_tx_send_packet, > + .ccid_hc_tx_packet_sent = ccid4_hc_tx_packet_sent, > + .ccid_hc_tx_packet_recv = ccid4_hc_tx_packet_recv, > + .ccid_hc_tx_parse_options = ccid4_hc_tx_parse_options, > + .ccid_hc_rx_obj_size = sizeof(struct ccid4_hc_rx_sock), > + .ccid_hc_rx_init = ccid4_hc_rx_init, > + .ccid_hc_rx_exit = ccid4_hc_rx_exit, > + .ccid_hc_rx_insert_options = ccid4_hc_rx_insert_options, > + .ccid_hc_rx_packet_recv = ccid4_hc_rx_packet_recv, > + .ccid_hc_rx_get_info = ccid4_hc_rx_get_info, > + .ccid_hc_tx_get_info = ccid4_hc_tx_get_info, > + .ccid_hc_rx_getsockopt = ccid4_hc_rx_getsockopt, > + .ccid_hc_tx_getsockopt = ccid4_hc_tx_getsockopt, > +}; > + > +#ifdef CONFIG_IP_DCCP_CCID4_DEBUG > +module_param(ccid4_debug, bool, 0444); > +MODULE_PARM_DESC(ccid4_debug, "Enable debug messages"); > +#endif > + > +static __init int ccid4_module_init(void) > +{ > + int rc = -ENOBUFS; > + > + if (tfrc_tx_cache_init(&ccid4_tx_hist, "ccid4")) > + goto out; > + > + rc = ccid_register(&ccid4); > + if (rc != 0) > + tfrc_tx_cache_cleanup(ccid4_tx_hist); > +out: > + return rc; > +} > +module_init(ccid4_module_init); > + > +static __exit void ccid4_module_exit(void) > +{ > + ccid_unregister(&ccid4); > + > + if (ccid4_tx_hist != NULL) > + tfrc_tx_cache_cleanup(ccid4_tx_hist); > +} > +module_exit(ccid4_module_exit); > + > +MODULE_AUTHOR("Ian McDonald <ian.mcdonald@xxxxxxxxxxx>, " > + "Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("DCCP TFRC CCID4 CCID"); > +MODULE_LICENSE("GPL"); > +MODULE_ALIAS("net-dccp-ccid-4"); > diff --git a/net/dccp/ccids/ccid4.h b/net/dccp/ccids/ccid4.h > new file mode 100644 > index 0000000..d233f6d > --- /dev/null > +++ b/net/dccp/ccids/ccid4.h > @@ -0,0 +1,177 @@ > +#ifndef _DCCP_CCID4_H_ > +#define _DCCP_CCID4_H_ > +/* > + * net/dccp/ccids/ccid4.h > + * > + * 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 http://www.wand.net.nz/ > + * or e-mail Ian McDonald - ian.mcdonald@xxxxxxxxxxx > + * > + * 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 ccid4 draft > + * and to make it work as a loadable module in the DCCP stack written by > + * Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxx>. > + * > + * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxx> > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program; if not, write to the Free Software > + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. > + */ > +#include <linux/ktime.h> > +#include <linux/list.h> > +#include <linux/types.h> > +#include <linux/tfrc.h> > +#include <asm/unaligned.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 > + > +enum ccid4_options { > + TFRC_OPT_LOSS_EVENT_RATE = 192, > + TFRC_OPT_LOSS_INTERVALS = 193, > + TFRC_OPT_RECEIVE_RATE = 194, > +}; > + > +struct ccid4_options_received { > + u64 ccid4or_seqno:48, > + ccid4or_loss_intervals_idx:16; > + u16 ccid4or_loss_intervals_len; > + u32 ccid4or_loss_event_rate; > + u32 ccid4or_receive_rate; > +}; > + > +/* TFRC sender states */ > +enum ccid4_hc_tx_states { > + TFRC_SSTATE_NO_SENT = 1, > + TFRC_SSTATE_NO_FBACK, > + TFRC_SSTATE_FBACK, > + TFRC_SSTATE_TERM, > +}; > + > +/** struct ccid4_hc_tx_sock - CCID4 sender half-connection socket > + * > + * @ccid4hctx_x - Current sending rate in 64 * bytes per second > + * @ccid4hctx_x_recv - Receive rate in 64 * bytes per second > + * @ccid4hctx_x_calc - Calculated rate in bytes per second > + * @ccid4hctx_rtt - Estimate of current round trip time in usecs > + * @ccid4hctx_p - Current loss event rate (0-1) scaled by 1000000 > + * @ccid4hctx_s - Packet size in bytes > + * @ccid4hctx_t_rto - Nofeedback Timer setting in usecs > + * @ccid4hctx_t_ipi - Interpacket (send) interval (RFC 3448, 4.6) in usecs > + * @ccid4hctx_state - Sender state, one of %ccid4_hc_tx_states > + * @ccid4hctx_last_win_count - Last window counter sent > + * @ccid4hctx_t_last_win_count - Timestamp of earliest packet > + * with last_win_count value sent > + * @ccid4hctx_no_feedback_timer - Handle to no feedback timer > + * @ccid4hctx_t_ld - Time last doubled during slow start > + * @ccid4hctx_t_nom - Nominal send time of next packet > + * @ccid4hctx_delta - Send timer delta (RFC 3448, 4.6) in usecs > + * @ccid4hctx_hist - Packet history > + * @ccid4hctx_options_received - Parsed set of retrieved options > + */ > +struct ccid4_hc_tx_sock { > + struct tfrc_tx_info ccid4hctx_tfrc; > +#define ccid4hctx_x ccid4hctx_tfrc.tfrctx_x > +#define ccid4hctx_x_recv ccid4hctx_tfrc.tfrctx_x_recv > +#define ccid4hctx_x_calc ccid4hctx_tfrc.tfrctx_x_calc > +#define ccid4hctx_rtt ccid4hctx_tfrc.tfrctx_rtt > +#define ccid4hctx_p ccid4hctx_tfrc.tfrctx_p > +#define ccid4hctx_t_rto ccid4hctx_tfrc.tfrctx_rto > +#define ccid4hctx_t_ipi ccid4hctx_tfrc.tfrctx_ipi > + u16 ccid4hctx_s; > + enum ccid4_hc_tx_states ccid4hctx_state:8; > + u8 ccid4hctx_last_win_count; > + ktime_t ccid4hctx_t_last_win_count; > + struct timer_list ccid4hctx_no_feedback_timer; > + ktime_t ccid4hctx_t_ld; > + ktime_t ccid4hctx_t_nom; > + u32 ccid4hctx_delta; > + struct tfrc_tx_hist_head ccid4hctx_hist; > + struct ccid4_options_received ccid4hctx_options_received; > +}; > + > +static inline struct ccid4_hc_tx_sock *ccid4_hc_tx_sk(const struct sock *sk) > +{ > + void *ccid4_tx_priv = ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid); > + > + BUG_ON(ccid4_tx_priv == NULL); > + return ccid4_tx_priv; > +} > + > +/* CCID4 receiver states */ > +enum ccid4_hc_rx_states { > + TFRC_RSTATE_NO_DATA = 1, > + TFRC_RSTATE_DATA, > + TFRC_RSTATE_TERM = 127, > +}; > + > +/* CCID4 feedback types */ > +enum ccid4_fback_type { > + FBACK_NONE = 0, > + FBACK_INITIAL, > + FBACK_PERIODIC, > + FBACK_PARAM_CHANGE > +}; > + > +/** struct ccid4_hc_rx_sock - CCID4 receiver half-connection socket > + * > + * @ccid4hcrx_last_counter - Tracks window counter (RFC 4342, 8.1) > + * @ccid4hcrx_state - Receiver state, one of %ccid4_hc_rx_states > + * @ccid4hcrx_bytes_recv - Total sum of DCCP payload bytes > + * @ccid4hcrx_x_recv - Receiver estimate of send rate (RFC 3448, sec. 4.3) > + * @ccid4hcrx_rtt - Receiver estimate of RTT > + * @ccid4hcrx_last_feedback - Time at which last feedback was sent > + * @ccid4hcrx_hist - Packet history, exported by TFRC module > + * @ccid4hcrx_li_hist - Loss Interval database, exported by TFRC module > + * @ccid4hcrx_s - Received packet size in bytes > + * @ccid4hcrx_pinv - Inverse of Loss Event Rate (RFC 4342, sec. 8.5) > + */ > +struct ccid4_hc_rx_sock { > + u8 ccid4hcrx_last_counter:4; > + enum ccid4_hc_rx_states ccid4hcrx_state:8; > + u32 ccid4hcrx_bytes_recv; > + u32 ccid4hcrx_x_recv; > + u32 ccid4hcrx_rtt; > + ktime_t ccid4hcrx_last_feedback; > + struct tfrc_rx_hist ccid4hcrx_hist; > + struct tfrc_loss_hist ccid4hcrx_li_hist; > + u16 ccid4hcrx_s; > +#define ccid4hcrx_pinv ccid4hcrx_li_hist.i_mean > +}; > + > +static inline struct ccid4_hc_rx_sock *ccid4_hc_rx_sk(const struct sock *sk) > +{ > + void *ccid4_rx_priv = ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid); > + > + BUG_ON(ccid4_rx_priv == NULL); > + return ccid4_rx_priv; > +} > + > +#endif /* _DCCP_CCID4_H_ */ > - > To unsubscribe from this list: send the line "unsubscribe dccp" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Signed-off-by: Leandro Sales <leandro@xxxxxxxxxxxxxxxxxxxx> - To unsubscribe from this list: send the line "unsubscribe dccp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
