diff options
Diffstat (limited to 'net/dccp/ccids/ccid3.c')
| -rw-r--r-- | net/dccp/ccids/ccid3.c | 1582 |
1 files changed, 591 insertions, 991 deletions
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index aa68e0ab274..119c04317d4 100644 --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c @@ -1,8 +1,7 @@ /* - * net/dccp/ccids/ccid3.c - * - * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand. - * Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz> + * 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@jandi.co.nz> * * An implementation of the DCCP protocol * @@ -33,1109 +32,806 @@ * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ - -#include <linux/config.h> -#include "../ccid.h" #include "../dccp.h" -#include "lib/packet_history.h" -#include "lib/loss_interval.h" -#include "lib/tfrc.h" #include "ccid3.h" -/* - * Reason for maths here is to avoid 32 bit overflow when a is big. - * With this we get close to the limit. - */ -static inline u32 usecs_div(const u32 a, const u32 b) -{ - const u32 div = a < (UINT_MAX / (USEC_PER_SEC / 10)) ? 10 : - a < (UINT_MAX / (USEC_PER_SEC / 50)) ? 50 : - a < (UINT_MAX / (USEC_PER_SEC / 100)) ? 100 : - a < (UINT_MAX / (USEC_PER_SEC / 500)) ? 500 : - a < (UINT_MAX / (USEC_PER_SEC / 1000)) ? 1000 : - a < (UINT_MAX / (USEC_PER_SEC / 5000)) ? 5000 : - a < (UINT_MAX / (USEC_PER_SEC / 10000)) ? 10000 : - a < (UINT_MAX / (USEC_PER_SEC / 50000)) ? 50000 : - 100000; - const u32 tmp = a * (USEC_PER_SEC / div); - return (b >= 2 * div) ? tmp / (b / div) : tmp; -} +#include <asm/unaligned.h> -static int ccid3_debug; - -#ifdef CCID3_DEBUG -#define ccid3_pr_debug(format, a...) \ - do { if (ccid3_debug) \ - printk(KERN_DEBUG "%s: " format, __FUNCTION__, ##a); \ - } while (0) +#ifdef CONFIG_IP_DCCP_CCID3_DEBUG +static bool ccid3_debug; +#define ccid3_pr_debug(format, a...) DCCP_PR_DEBUG(ccid3_debug, format, ##a) #else #define ccid3_pr_debug(format, a...) #endif -static struct dccp_tx_hist *ccid3_tx_hist; -static struct dccp_rx_hist *ccid3_rx_hist; -static struct dccp_li_hist *ccid3_li_hist; - -static int ccid3_init(struct sock *sk) -{ - return 0; -} - -static void ccid3_exit(struct sock *sk) -{ -} - -/* TFRC sender states */ -enum ccid3_hc_tx_states { - TFRC_SSTATE_NO_SENT = 1, - TFRC_SSTATE_NO_FBACK, - TFRC_SSTATE_FBACK, - TFRC_SSTATE_TERM, -}; - -#ifdef CCID3_DEBUG +/* + * Transmitter Half-Connection Routines + */ +#ifdef CONFIG_IP_DCCP_CCID3_DEBUG static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state) { - static char *ccid3_state_names[] = { + static const char *const ccid3_state_names[] = { [TFRC_SSTATE_NO_SENT] = "NO_SENT", [TFRC_SSTATE_NO_FBACK] = "NO_FBACK", [TFRC_SSTATE_FBACK] = "FBACK", - [TFRC_SSTATE_TERM] = "TERM", }; return ccid3_state_names[state]; } #endif -static inline void ccid3_hc_tx_set_state(struct sock *sk, - enum ccid3_hc_tx_states state) +static void ccid3_hc_tx_set_state(struct sock *sk, + enum ccid3_hc_tx_states state) { - struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); - enum ccid3_hc_tx_states oldstate = hctx->ccid3hctx_state; + struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); + enum ccid3_hc_tx_states oldstate = hc->tx_state; ccid3_pr_debug("%s(%p) %-8.8s -> %s\n", dccp_role(sk), sk, ccid3_tx_state_name(oldstate), ccid3_tx_state_name(state)); WARN_ON(state == oldstate); - hctx->ccid3hctx_state = state; + hc->tx_state = state; } -/* Calculate new t_ipi (inter packet interval) by t_ipi = s / X_inst */ -static inline void ccid3_calc_new_t_ipi(struct ccid3_hc_tx_sock *hctx) +/* + * 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 ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); + const __u32 w_init = clamp_t(__u32, 4380U, 2 * hc->tx_s, 4 * hc->tx_s); + + return scaled_div(w_init << 6, hc->tx_rtt); +} + +/** + * ccid3_update_send_interval - Calculate new t_ipi = s / X_inst + * This respects the granularity of X_inst (64 * bytes/second). + */ +static void ccid3_update_send_interval(struct ccid3_hc_tx_sock *hc) +{ + hc->tx_t_ipi = scaled_div32(((u64)hc->tx_s) << 6, hc->tx_x); + + DCCP_BUG_ON(hc->tx_t_ipi == 0); + ccid3_pr_debug("t_ipi=%u, s=%u, X=%u\n", hc->tx_t_ipi, + hc->tx_s, (unsigned int)(hc->tx_x >> 6)); +} + +static u32 ccid3_hc_tx_idle_rtt(struct ccid3_hc_tx_sock *hc, ktime_t now) +{ + u32 delta = ktime_us_delta(now, hc->tx_t_last_win_count); + + return delta / hc->tx_rtt; +} + +/** + * ccid3_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 ccid3_hc_tx_update_x(struct sock *sk, ktime_t *stamp) { + struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); + __u64 min_rate = 2 * hc->tx_x_recv; + const __u64 old_x = hc->tx_x; + ktime_t now = stamp ? *stamp : ktime_get_real(); + /* - * If no feedback spec says t_ipi is 1 second (set elsewhere and then - * doubles after every no feedback timer (separate function) + * 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 (hctx->ccid3hctx_state != TFRC_SSTATE_NO_FBACK) - hctx->ccid3hctx_t_ipi = usecs_div(hctx->ccid3hctx_s, - hctx->ccid3hctx_x); + if (ccid3_hc_tx_idle_rtt(hc, now) >= 2) { + min_rate = rfc3390_initial_rate(sk); + min_rate = max(min_rate, 2 * hc->tx_x_recv); + } + + if (hc->tx_p > 0) { + + hc->tx_x = min(((__u64)hc->tx_x_calc) << 6, min_rate); + hc->tx_x = max(hc->tx_x, (((__u64)hc->tx_s) << 6) / TFRC_T_MBI); + + } else if (ktime_us_delta(now, hc->tx_t_ld) - (s64)hc->tx_rtt >= 0) { + + hc->tx_x = min(2 * hc->tx_x, min_rate); + hc->tx_x = max(hc->tx_x, + scaled_div(((__u64)hc->tx_s) << 6, hc->tx_rtt)); + hc->tx_t_ld = now; + } + + if (hc->tx_x != old_x) { + ccid3_pr_debug("X_prev=%u, X_now=%u, X_calc=%u, " + "X_recv=%u\n", (unsigned int)(old_x >> 6), + (unsigned int)(hc->tx_x >> 6), hc->tx_x_calc, + (unsigned int)(hc->tx_x_recv >> 6)); + + ccid3_update_send_interval(hc); + } } -/* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */ -static inline void ccid3_calc_new_delta(struct ccid3_hc_tx_sock *hctx) +/** + * ccid3_hc_tx_update_s - Track the mean packet size `s' + * @len: DCCP packet payload size in bytes + * + * cf. RFC 4342, 5.3 and RFC 3448, 4.1 + */ +static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hc, int len) { - hctx->ccid3hctx_delta = min_t(u32, hctx->ccid3hctx_t_ipi / 2, - TFRC_OPSYS_HALF_TIME_GRAN); + const u16 old_s = hc->tx_s; + + hc->tx_s = tfrc_ewma(hc->tx_s, len, 9); + + if (hc->tx_s != old_s) + ccid3_update_send_interval(hc); } /* - * Update X by - * If (p > 0) - * x_calc = calcX(s, R, p); - * X = max(min(X_calc, 2 * X_recv), s / t_mbi); - * Else - * If (now - tld >= R) - * X = max(min(2 * X, 2 * X_recv), s / R); - * tld = now; - */ -static void ccid3_hc_tx_update_x(struct sock *sk) + * Update Window Counter using the algorithm from [RFC 4342, 8.1]. + * As elsewhere, RTT > 0 is assumed by using dccp_sample_rtt(). + */ +static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hc, + ktime_t now) { - struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); - - /* To avoid large error in calcX */ - if (hctx->ccid3hctx_p >= TFRC_SMALLEST_P) { - hctx->ccid3hctx_x_calc = tfrc_calc_x(hctx->ccid3hctx_s, - hctx->ccid3hctx_rtt, - hctx->ccid3hctx_p); - hctx->ccid3hctx_x = max_t(u32, min_t(u32, hctx->ccid3hctx_x_calc, - 2 * hctx->ccid3hctx_x_recv), - (hctx->ccid3hctx_s / - TFRC_MAX_BACK_OFF_TIME)); - } else { - struct timeval now; - - dccp_timestamp(sk, &now); - if (timeval_delta(&now, &hctx->ccid3hctx_t_ld) >= - hctx->ccid3hctx_rtt) { - hctx->ccid3hctx_x = max_t(u32, min_t(u32, hctx->ccid3hctx_x_recv, - hctx->ccid3hctx_x) * 2, - usecs_div(hctx->ccid3hctx_s, - hctx->ccid3hctx_rtt)); - hctx->ccid3hctx_t_ld = now; - } + u32 delta = ktime_us_delta(now, hc->tx_t_last_win_count), + quarter_rtts = (4 * delta) / hc->tx_rtt; + + if (quarter_rtts > 0) { + hc->tx_t_last_win_count = now; + hc->tx_last_win_count += min(quarter_rtts, 5U); + hc->tx_last_win_count &= 0xF; /* mod 16 */ } } static void ccid3_hc_tx_no_feedback_timer(unsigned long data) { struct sock *sk = (struct sock *)data; - unsigned long next_tmout = 0; - struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); + struct ccid3_hc_tx_sock *hc = ccid3_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 */ - sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, - jiffies + HZ / 5); - goto out; + goto restart_timer; } - ccid3_pr_debug("%s, sk=%p, state=%s\n", dccp_role(sk), sk, - ccid3_tx_state_name(hctx->ccid3hctx_state)); - - switch (hctx->ccid3hctx_state) { - case TFRC_SSTATE_TERM: + ccid3_pr_debug("%s(%p, state=%s) - entry\n", dccp_role(sk), sk, + ccid3_tx_state_name(hc->tx_state)); + + /* Ignore and do not restart after leaving the established state */ + if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN)) goto out; - case TFRC_SSTATE_NO_FBACK: - /* Halve send rate */ - hctx->ccid3hctx_x /= 2; - if (hctx->ccid3hctx_x < (hctx->ccid3hctx_s / - TFRC_MAX_BACK_OFF_TIME)) - hctx->ccid3hctx_x = (hctx->ccid3hctx_s / - TFRC_MAX_BACK_OFF_TIME); - - ccid3_pr_debug("%s, sk=%p, state=%s, updated tx rate to %d " - "bytes/s\n", - dccp_role(sk), sk, - ccid3_tx_state_name(hctx->ccid3hctx_state), - hctx->ccid3hctx_x); - next_tmout = max_t(u32, 2 * usecs_div(hctx->ccid3hctx_s, - hctx->ccid3hctx_x), - TFRC_INITIAL_TIMEOUT); - /* - * FIXME - not sure above calculation is correct. See section - * 5 of CCID3 11 should adjust tx_t_ipi and double that to - * achieve it really - */ - break; - case TFRC_SSTATE_FBACK: + + /* Reset feedback state to "no feedback received" */ + if (hc->tx_state == TFRC_SSTATE_FBACK) + ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); + + /* + * Determine new allowed sending rate X as per draft rfc3448bis-00, 4.4 + * RTO is 0 if and only if no feedback has been received yet. + */ + if (hc->tx_t_rto == 0 || hc->tx_p == 0) { + + /* halve send rate directly */ + hc->tx_x = max(hc->tx_x / 2, + (((__u64)hc->tx_s) << 6) / TFRC_T_MBI); + ccid3_update_send_interval(hc); + } else { /* - * Check if IDLE since last timeout and recv rate is less than - * 4 packets per RTT + * 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 */ - if (!hctx->ccid3hctx_idle || - (hctx->ccid3hctx_x_recv >= - 4 * usecs_div(hctx->ccid3hctx_s, hctx->ccid3hctx_rtt))) { - ccid3_pr_debug("%s, sk=%p, state=%s, not idle\n", - dccp_role(sk), sk, - ccid3_tx_state_name(hctx->ccid3hctx_state)); - /* Halve sending rate */ - - /* If (X_calc > 2 * X_recv) - * X_recv = max(X_recv / 2, s / (2 * t_mbi)); - * Else - * X_recv = X_calc / 4; - */ - BUG_ON(hctx->ccid3hctx_p >= TFRC_SMALLEST_P && - hctx->ccid3hctx_x_calc == 0); - - /* check also if p is zero -> x_calc is infinity? */ - if (hctx->ccid3hctx_p < TFRC_SMALLEST_P || - hctx->ccid3hctx_x_calc > 2 * hctx->ccid3hctx_x_recv) - hctx->ccid3hctx_x_recv = max_t(u32, hctx->ccid3hctx_x_recv / 2, - hctx->ccid3hctx_s / (2 * TFRC_MAX_BACK_OFF_TIME)); - else - hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc / 4; - - /* Update sending rate */ - ccid3_hc_tx_update_x(sk); + if (hc->tx_x_calc > (hc->tx_x_recv >> 5)) + hc->tx_x_recv = + max(hc->tx_x_recv / 2, + (((__u64)hc->tx_s) << 6) / (2*TFRC_T_MBI)); + else { + hc->tx_x_recv = hc->tx_x_calc; + hc->tx_x_recv <<= 4; } - /* - * Schedule no feedback timer to expire in - * max(4 * R, 2 * s / X) - */ - next_tmout = max_t(u32, hctx->ccid3hctx_t_rto, - 2 * usecs_div(hctx->ccid3hctx_s, - hctx->ccid3hctx_x)); - break; - default: - printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n", - __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state); - dump_stack(); - goto out; + ccid3_hc_tx_update_x(sk, NULL); } + ccid3_pr_debug("Reduced X to %llu/64 bytes/sec\n", + (unsigned long long)hc->tx_x); + + /* + * Set new timeout for the nofeedback timer. + * See comments in packet_recv() regarding the value of t_RTO. + */ + if (unlikely(hc->tx_t_rto == 0)) /* no feedback received yet */ + t_nfb = TFRC_INITIAL_TIMEOUT; + else + t_nfb = max(hc->tx_t_rto, 2 * hc->tx_t_ipi); - sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, - jiffies + max_t(u32, 1, usecs_to_jiffies(next_tmout))); - hctx->ccid3hctx_idle = 1; +restart_timer: + sk_reset_timer(sk, &hc->tx_no_feedback_timer, + jiffies + usecs_to_jiffies(t_nfb)); out: bh_unlock_sock(sk); sock_put(sk); } -static int ccid3_hc_tx_send_packet(struct sock *sk, - struct sk_buff *skb, int len) +/** + * ccid3_hc_tx_send_packet - Delay-based dequeueing of TX packets + * @skb: next packet candidate to send on @sk + * + * This function uses the convention of ccid_packet_dequeue_eval() and + * returns a millisecond-delay value between 0 and t_mbi = 64000 msec. + */ +static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) { struct dccp_sock *dp = dccp_sk(sk); - struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); - struct dccp_tx_hist_entry *new_packet; - struct timeval now; - long delay; - int rc = -ENOTCONN; + struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); + ktime_t now = ktime_get_real(); + s64 delay; - BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM); - - /* Check if pure ACK or Terminating*/ /* - * XXX: We only call this function for DATA and DATAACK, on, these - * packets can have zero length, but why the comment about "pure ACK"? + * 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(len == 0)) - goto out; + if (unlikely(skb->len == 0)) + return -EBADMSG; - /* See if last packet allocated was not sent */ - new_packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist); - if (new_packet == NULL || new_packet->dccphtx_sent) { - new_packet = dccp_tx_hist_entry_new(ccid3_tx_hist, - SLAB_ATOMIC); - - rc = -ENOBUFS; - if (unlikely(new_packet == NULL)) { - LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, not enough " - "mem to add to history, send refused\n", - __FUNCTION__, dccp_role(sk), sk); - goto out; - } + if (hc->tx_state == TFRC_SSTATE_NO_SENT) { + sk_reset_timer(sk, &hc->tx_no_feedback_timer, (jiffies + + usecs_to_jiffies(TFRC_INITIAL_TIMEOUT))); + hc->tx_last_win_count = 0; + hc->tx_t_last_win_count = now; - dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, new_packet); - } + /* Set t_0 for initial packet */ + hc->tx_t_nom = now; - dccp_timestamp(sk, &now); + hc->tx_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) { + ccid3_pr_debug("SYN RTT = %uus\n", dp->dccps_syn_rtt); + hc->tx_rtt = dp->dccps_syn_rtt; + hc->tx_x = rfc3390_initial_rate(sk); + hc->tx_t_ld = now; + } else { + /* + * Sender does not have RTT sample: + * - set fallback RTT (RFC 4340, 3.4) since a RTT value + * is needed in several parts (e.g. window counter); + * - set sending rate X_pps = 1pps as per RFC 3448, 4.2. + */ + hc->tx_rtt = DCCP_FALLBACK_RTT; + hc->tx_x = hc->tx_s; + hc->tx_x <<= 6; + } + ccid3_update_send_interval(hc); - switch (hctx->ccid3hctx_state) { - case TFRC_SSTATE_NO_SENT: - hctx->ccid3hctx_no_feedback_timer.function = ccid3_hc_tx_no_feedback_timer; - hctx->ccid3hctx_no_feedback_timer.data = (unsigned long)sk; - sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, - jiffies + usecs_to_jiffies(TFRC_INITIAL_TIMEOUT)); - hctx->ccid3hctx_last_win_count = 0; - hctx->ccid3hctx_t_last_win_count = now; ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); - hctx->ccid3hctx_t_ipi = TFRC_INITIAL_IPI; - - /* Set nominal send time for initial packet */ - hctx->ccid3hctx_t_nom = now; - timeval_add_usecs(&hctx->ccid3hctx_t_nom, - hctx->ccid3hctx_t_ipi); - ccid3_calc_new_delta(hctx); - rc = 0; - break; - case TFRC_SSTATE_NO_FBACK: - case TFRC_SSTATE_FBACK: - delay = (timeval_delta(&now, &hctx->ccid3hctx_t_nom) - - hctx->ccid3hctx_delta); - delay /= -1000; - /* divide by -1000 is to convert to ms and get sign right */ - rc = delay > 0 ? delay : 0; - break; - default: - printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n", - __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state); - dump_stack(); - rc = -EINVAL; - break; - } - /* Can we send? if so add options and add to packet history */ - if (rc == 0) { - dp->dccps_hc_tx_insert_options = 1; - new_packet->dccphtx_ccval = - DCCP_SKB_CB(skb)->dccpd_ccval = - hctx->ccid3hctx_last_win_count; - } -out: - return rc; -} + } else { + delay = ktime_us_delta(hc->tx_t_nom, now); + ccid3_pr_debug("delay=%ld\n", (long)delay); + /* + * Scheduling of packet transmissions (RFC 5348, 8.3) + * + * if (t_now > t_nom - delta) + * // send the packet now + * else + * // send the packet in (t_nom - t_now) milliseconds. + */ + if (delay >= TFRC_T_DELTA) + return (u32)delay / USEC_PER_MSEC; -static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, int len) -{ - const struct dccp_sock *dp = dccp_sk(sk); - struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); - struct timeval now; + ccid3_hc_tx_update_win_count(hc, now); + } - BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM); + /* prepare to send now (add options etc.) */ + dp->dccps_hc_tx_insert_options = 1; + DCCP_SKB_CB(skb)->dccpd_ccval = hc->tx_last_win_count; - dccp_timestamp(sk, &now); + /* set the nominal send time for the next following packet */ + hc->tx_t_nom = ktime_add_us(hc->tx_t_nom, hc->tx_t_ipi); + return CCID_PACKET_SEND_AT_ONCE; +} - /* check if we have sent a data packet */ - if (len > 0) { - unsigned long quarter_rtt; - struct dccp_tx_hist_entry *packet; +static void ccid3_hc_tx_packet_sent(struct sock *sk, unsigned int len) +{ + struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); - packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist); - if (unlikely(packet == NULL)) { - LIMIT_NETDEBUG(KERN_WARNING "%s: packet doesn't " - "exists in history!\n", __FUNCTION__); - return; - } - if (unlikely(packet->dccphtx_sent)) { - LIMIT_NETDEBUG(KERN_WARNING "%s: no unsent packet in " - "history!\n", __FUNCTION__); - return; - } - packet->dccphtx_tstamp = now; - packet->dccphtx_seqno = dp->dccps_gss; - /* - * Check if win_count have changed - * Algorithm in "8.1. Window Counter Valuer" in - * draft-ietf-dccp-ccid3-11.txt - */ - quarter_rtt = timeval_delta(&now, &hctx->ccid3hctx_t_last_win_count); - if (likely(hctx->ccid3hctx_rtt > 8)) - quarter_rtt /= hctx->ccid3hctx_rtt / 4; - - if (quarter_rtt > 0) { - hctx->ccid3hctx_t_last_win_count = now; - hctx->ccid3hctx_last_win_count = (hctx->ccid3hctx_last_win_count + - min_t(unsigned long, quarter_rtt, 5)) % 16; - ccid3_pr_debug("%s, sk=%p, window changed from " - "%u to %u!\n", - dccp_role(sk), sk, - packet->dccphtx_ccval, - hctx->ccid3hctx_last_win_count); - } + ccid3_hc_tx_update_s(hc, len); - hctx->ccid3hctx_idle = 0; - packet->dccphtx_rtt = hctx->ccid3hctx_rtt; - packet->dccphtx_sent = 1; - } else - ccid3_pr_debug("%s, sk=%p, seqno=%llu NOT inserted!\n", - dccp_role(sk), sk, dp->dccps_gss); - - switch (hctx->ccid3hctx_state) { - case TFRC_SSTATE_NO_SENT: - /* if first wasn't pure ack */ - if (len != 0) - printk(KERN_CRIT "%s: %s, First packet sent is noted " - "as a data packet\n", - __FUNCTION__, dccp_role(sk)); - return; - case TFRC_SSTATE_NO_FBACK: - case TFRC_SSTATE_FBACK: - if (len > 0) { - hctx->ccid3hctx_t_nom = now; - ccid3_calc_new_t_ipi(hctx); - ccid3_calc_new_delta(hctx); - timeval_add_usecs(&hctx->ccid3hctx_t_nom, - hctx->ccid3hctx_t_ipi); - } - break; - default: - printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n", - __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state); - dump_stack(); - break; - } + if (tfrc_tx_hist_add(&hc->tx_hist, dccp_sk(sk)->dccps_gss)) + DCCP_CRIT("packet history - out of memory!"); } static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) { - const struct dccp_sock *dp = dccp_sk(sk); - struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); - struct ccid3_options_received *opt_recv; - struct dccp_tx_hist_entry *packet; - struct timeval now; - unsigned long next_tmout; - u32 t_elapsed; - u32 pinv; - u32 x_recv; + struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); + struct tfrc_tx_hist_entry *acked; + ktime_t now; + unsigned long t_nfb; u32 r_sample; - BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM); - /* 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; + /* + * Locate the acknowledged packet in the TX history. + * + * Returning "entry not found" here can for instance happen when + * - the host has not sent out anything (e.g. a passive server), + * - the Ack is outdated (packet with higher Ack number was received), + * - it is a bogus Ack (for a packet not sent on this connection). + */ + acked = tfrc_tx_hist_find_entry(hc->tx_hist, dccp_hdr_ack_seq(skb)); + if (acked == NULL) + return; + /* For the sake of RTT sampling, ignore/remove all older entries */ + tfrc_tx_hist_purge(&acked->next); - opt_recv = &hctx->ccid3hctx_options_received; + /* Update the moving average for the RTT estimate (RFC 3448, 4.3) */ + now = ktime_get_real(); + r_sample = dccp_sample_rtt(sk, ktime_us_delta(now, acked->stamp)); + hc->tx_rtt = tfrc_ewma(hc->tx_rtt, r_sample, 9); - t_elapsed = dp->dccps_options_received.dccpor_elapsed_time * 10; - x_recv = opt_recv->ccid3or_receive_rate; - pinv = opt_recv->ccid3or_loss_event_rate; + /* + * Update allowed sending rate X as per draft rfc3448bis-00, 4.2/3 + */ + if (hc->tx_state == TFRC_SSTATE_NO_FBACK) { + ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK); - switch (hctx->ccid3hctx_state) { - case TFRC_SSTATE_NO_SENT: - /* FIXME: what to do here? */ - return; - case TFRC_SSTATE_NO_FBACK: - case TFRC_SSTATE_FBACK: - /* Calculate new round trip sample by - * R_sample = (now - t_recvdata) - t_delay */ - /* get t_recvdata from history */ - packet = dccp_tx_hist_find_entry(&hctx->ccid3hctx_hist, - DCCP_SKB_CB(skb)->dccpd_ack_seq); - if (unlikely(packet == NULL)) { - LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, seqno " - "%llu(%s) does't exist in history!\n", - __FUNCTION__, dccp_role(sk), sk, - (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq, - dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type)); - return; - } + if (hc->tx_t_rto == 0) { + /* + * Initial feedback packet: Larger Initial Windows (4.2) + */ + hc->tx_x = rfc3390_initial_rate(sk); + hc->tx_t_ld = now; - /* Update RTT */ - dccp_timestamp(sk, &now); - r_sample = timeval_delta(&now, &packet->dccphtx_tstamp); - if (unlikely(r_sample <= t_elapsed)) - LIMIT_NETDEBUG(KERN_WARNING "%s: r_sample=%uus, " - "t_elapsed=%uus\n", - __FUNCTION__, r_sample, t_elapsed); - else - r_sample -= t_elapsed; + ccid3_update_send_interval(hc); - /* Update RTT estimate by - * If (No feedback recv) - * R = R_sample; - * Else - * R = q * R + (1 - q) * R_sample; - * - * q is a constant, RFC 3448 recomments 0.9 - */ - if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) { - ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK); - hctx->ccid3hctx_rtt = r_sample; - } else - hctx->ccid3hctx_rtt = (hctx->ccid3hctx_rtt * 9) / 10 + - r_sample / 10; - - ccid3_pr_debug("%s, sk=%p, New RTT estimate=%uus, " - "r_sample=%us\n", dccp_role(sk), sk, - hctx->ccid3hctx_rtt, r_sample); - - /* Update timeout interval */ - hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt, - USEC_PER_SEC); - - /* Update receive rate */ - hctx->ccid3hctx_x_recv = x_recv;/* X_recv in bytes per sec */ - - /* Update loss event rate */ - if (pinv == ~0 || pinv == 0) - hctx->ccid3hctx_p = 0; - else { - hctx->ccid3hctx_p = 1000000 / pinv; - - if (hctx->ccid3hctx_p < TFRC_SMALLEST_P) { - hctx->ccid3hctx_p = TFRC_SMALLEST_P; - ccid3_pr_debug("%s, sk=%p, Smallest p used!\n", - dccp_role(sk), sk); - } + goto done_computing_x; + } else if (hc->tx_p == 0) { + /* + * First feedback after nofeedback timer expiry (4.3) + */ + goto done_computing_x; } + } - /* unschedule no feedback timer */ - sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer); - - /* Update sending rate */ - ccid3_hc_tx_update_x(sk); + /* Update sending rate (step 4 of [RFC 3448, 4.3]) */ + if (hc->tx_p > 0) + hc->tx_x_calc = tfrc_calc_x(hc->tx_s, hc->tx_rtt, hc->tx_p); + ccid3_hc_tx_update_x(sk, &now); - /* Update next send time */ - timeval_sub_usecs(&hctx->ccid3hctx_t_nom, - hctx->ccid3hctx_t_ipi); - ccid3_calc_new_t_ipi(hctx); - timeval_add_usecs(&hctx->ccid3hctx_t_nom, - hctx->ccid3hctx_t_ipi); - ccid3_calc_new_delta(hctx); +done_computing_x: + ccid3_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, hc->tx_rtt, r_sample, + hc->tx_s, hc->tx_p, hc->tx_x_calc, + (unsigned int)(hc->tx_x_recv >> 6), + (unsigned int)(hc->tx_x >> 6)); - /* remove all packets older than the one acked from history */ - dccp_tx_hist_purge_older(ccid3_tx_hist, - &hctx->ccid3hctx_hist, packet); - /* - * 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_ccids. - */ - sk->sk_write_space(sk); + /* unschedule no feedback timer */ + sk_stop_timer(sk, &hc->tx_no_feedback_timer); - /* - * Schedule no feedback timer to expire in - * max(4 * R, 2 * s / X) - */ - next_tmout = max(hctx->ccid3hctx_t_rto, - 2 * usecs_div(hctx->ccid3hctx_s, - hctx->ccid3hctx_x)); - - ccid3_pr_debug("%s, sk=%p, Scheduled no feedback timer to " - "expire in %lu jiffies (%luus)\n", - dccp_role(sk), sk, - usecs_to_jiffies(next_tmout), next_tmout); - - sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, - jiffies + max_t(u32, 1, usecs_to_jiffies(next_tmout))); - - /* set idle flag */ - hctx->ccid3hctx_idle = 1; - break; - default: - printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n", - __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state); - dump_stack(); - break; - } -} - -static void ccid3_hc_tx_insert_options(struct sock *sk, struct sk_buff *skb) -{ - const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); + /* + * 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); - BUG_ON(hctx == NULL); + /* + * Update timeout interval for the nofeedback timer. In order to control + * rate halving on networks with very low RTTs (<= 1 ms), use per-route + * tunable RTAX_RTO_MIN value as the lower bound. + */ + hc->tx_t_rto = max_t(u32, 4 * hc->tx_rtt, + USEC_PER_SEC/HZ * tcp_rto_min(sk)); + /* + * Schedule no feedback timer to expire in + * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi) + */ + t_nfb = max(hc->tx_t_rto, 2 * hc->tx_t_ipi); - if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN)) - return; + ccid3_pr_debug("%s(%p), Scheduled no feedback timer to " + "expire in %lu jiffies (%luus)\n", + dccp_role(sk), sk, usecs_to_jiffies(t_nfb), t_nfb); - DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count; + sk_reset_timer(sk, &hc->tx_no_feedback_timer, + jiffies + usecs_to_jiffies(t_nfb)); } -static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option, - unsigned char len, u16 idx, - unsigned char *value) +static int ccid3_hc_tx_parse_options(struct sock *sk, u8 packet_type, + u8 option, u8 *optval, u8 optlen) { - int rc = 0; - const struct dccp_sock *dp = dccp_sk(sk); - struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); - struct ccid3_options_received *opt_recv; - - BUG_ON(hctx == NULL); - - opt_recv = &hctx->ccid3hctx_options_received; - - if (opt_recv->ccid3or_seqno != dp->dccps_gsr) { - opt_recv->ccid3or_seqno = dp->dccps_gsr; - opt_recv->ccid3or_loss_event_rate = ~0; - opt_recv->ccid3or_loss_intervals_idx = 0; - opt_recv->ccid3or_loss_intervals_len = 0; - opt_recv->ccid3or_receive_rate = 0; - } + struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); + __be32 opt_val; switch (option) { + case TFRC_OPT_RECEIVE_RATE: case TFRC_OPT_LOSS_EVENT_RATE: - if (unlikely(len != 4)) { - LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, invalid " - "len for TFRC_OPT_LOSS_EVENT_RATE\n", - __FUNCTION__, dccp_role(sk), sk); - rc = -EINVAL; - } else { - opt_recv->ccid3or_loss_event_rate = ntohl(*(u32 *)value); - ccid3_pr_debug("%s, sk=%p, LOSS_EVENT_RATE=%u\n", - dccp_role(sk), sk, - opt_recv->ccid3or_loss_event_rate); + /* Must be ignored on Data packets, cf. RFC 4342 8.3 and 8.5 */ + if (packet_type == DCCP_PKT_DATA) + break; + if (unlikely(optlen != 4)) { + DCCP_WARN("%s(%p), invalid len %d for %u\n", + dccp_role(sk), sk, optlen, option); + return -EINVAL; } - break; - case TFRC_OPT_LOSS_INTERVALS: - opt_recv->ccid3or_loss_intervals_idx = idx; - opt_recv->ccid3or_loss_intervals_len = len; - ccid3_pr_debug("%s, sk=%p, LOSS_INTERVALS=(%u, %u)\n", - dccp_role(sk), sk, - opt_recv->ccid3or_loss_intervals_idx, - opt_recv->ccid3or_loss_intervals_len); - break; - case TFRC_OPT_RECEIVE_RATE: - if (unlikely(len != 4)) { - LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, invalid " - "len for TFRC_OPT_RECEIVE_RATE\n", - __FUNCTION__, dccp_role(sk), sk); - rc = -EINVAL; + opt_val = ntohl(get_unaligned((__be32 *)optval)); + + if (option == TFRC_OPT_RECEIVE_RATE) { + /* Receive Rate is kept in units of 64 bytes/second */ + hc->tx_x_recv = opt_val; + hc->tx_x_recv <<= 6; + + ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n", + dccp_role(sk), sk, opt_val); } else { - opt_recv->ccid3or_receive_rate = ntohl(*(u32 *)value); - ccid3_pr_debug("%s, sk=%p, RECEIVE_RATE=%u\n", - dccp_role(sk), sk, - opt_recv->ccid3or_receive_rate); + /* Update the fixpoint Loss Event Rate fraction */ + hc->tx_p = tfrc_invert_loss_event_rate(opt_val); + + ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n", + dccp_role(sk), sk, opt_val); } - break; } - - return rc; + return 0; } -static int ccid3_hc_tx_init(struct sock *sk) +static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk) { - struct dccp_sock *dp = dccp_sk(sk); - struct ccid3_hc_tx_sock *hctx; - - dp->dccps_hc_tx_ccid_private = kmalloc(sizeof(*hctx), gfp_any()); - if (dp->dccps_hc_tx_ccid_private == NULL) - return -ENOMEM; - - hctx = ccid3_hc_tx_sk(sk); - memset(hctx, 0, sizeof(*hctx)); - - if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE && - dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE) - hctx->ccid3hctx_s = dp->dccps_packet_size; - else - hctx->ccid3hctx_s = TFRC_STD_PACKET_SIZE; - - /* Set transmission rate to 1 packet per second */ - hctx->ccid3hctx_x = hctx->ccid3hctx_s; - hctx->ccid3hctx_t_rto = USEC_PER_SEC; - hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT; - INIT_LIST_HEAD(&hctx->ccid3hctx_hist); - init_timer(&hctx->ccid3hctx_no_feedback_timer); + struct ccid3_hc_tx_sock *hc = ccid_priv(ccid); + hc->tx_state = TFRC_SSTATE_NO_SENT; + hc->tx_hist = NULL; + setup_timer(&hc->tx_no_feedback_timer, + ccid3_hc_tx_no_feedback_timer, (unsigned long)sk); return 0; } static void ccid3_hc_tx_exit(struct sock *sk) { - struct dccp_sock *dp = dccp_sk(sk); - struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); + struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); - BUG_ON(hctx == NULL); + sk_stop_timer(sk, &hc->tx_no_feedback_timer); + tfrc_tx_hist_purge(&hc->tx_hist); +} - ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM); - sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer); +static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info) +{ + info->tcpi_rto = ccid3_hc_tx_sk(sk)->tx_t_rto; + info->tcpi_rtt = ccid3_hc_tx_sk(sk)->tx_rtt; +} + +static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len, + u32 __user *optval, int __user *optlen) +{ + const struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); + struct tfrc_tx_info tfrc; + const void *val; + + switch (optname) { + case DCCP_SOCKOPT_CCID_TX_INFO: + if (len < sizeof(tfrc)) + return -EINVAL; + memset(&tfrc, 0, sizeof(tfrc)); + tfrc.tfrctx_x = hc->tx_x; + tfrc.tfrctx_x_recv = hc->tx_x_recv; + tfrc.tfrctx_x_calc = hc->tx_x_calc; + tfrc.tfrctx_rtt = hc->tx_rtt; + tfrc.tfrctx_p = hc->tx_p; + tfrc.tfrctx_rto = hc->tx_t_rto; + tfrc.tfrctx_ipi = hc->tx_t_ipi; + len = sizeof(tfrc); + val = &tfrc; + break; + default: + return -ENOPROTOOPT; + } - /* Empty packet history */ - dccp_tx_hist_purge(ccid3_tx_hist, &hctx->ccid3hctx_hist); + if (put_user(len, optlen) || copy_to_user(optval, val, len)) + return -EFAULT; - kfree(dp->dccps_hc_tx_ccid_private); - dp->dccps_hc_tx_ccid_private = NULL; + return 0; } /* - * RX Half Connection methods + * Receiver Half-Connection Routines */ -/* TFRC receiver states */ -enum ccid3_hc_rx_states { - TFRC_RSTATE_NO_DATA = 1, - TFRC_RSTATE_DATA, - TFRC_RSTATE_TERM = 127, +/* CCID3 feedback types */ +enum ccid3_fback_type { + CCID3_FBACK_NONE = 0, + CCID3_FBACK_INITIAL, + CCID3_FBACK_PERIODIC, + CCID3_FBACK_PARAM_CHANGE }; -#ifdef CCID3_DEBUG +#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[] = { + static const char *const ccid3_rx_state_names[] = { [TFRC_RSTATE_NO_DATA] = "NO_DATA", [TFRC_RSTATE_DATA] = "DATA", - [TFRC_RSTATE_TERM] = "TERM", }; return ccid3_rx_state_names[state]; } #endif -static inline void ccid3_hc_rx_set_state(struct sock *sk, - enum ccid3_hc_rx_states state) +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->ccid3hcrx_state; + struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); + enum ccid3_hc_rx_states oldstate = hc->rx_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->ccid3hcrx_state = state; + hc->rx_state = state; } -static void ccid3_hc_rx_send_feedback(struct sock *sk) +static void ccid3_hc_rx_send_feedback(struct sock *sk, + const struct sk_buff *skb, + enum ccid3_fback_type fbtype) { - struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); + struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); struct dccp_sock *dp = dccp_sk(sk); - struct dccp_rx_hist_entry *packet; - struct timeval now; - - ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk); + ktime_t now = ktime_get_real(); + s64 delta = 0; - dccp_timestamp(sk, &now); - - switch (hcrx->ccid3hcrx_state) { - case TFRC_RSTATE_NO_DATA: - hcrx->ccid3hcrx_x_recv = 0; + switch (fbtype) { + case CCID3_FBACK_INITIAL: + hc->rx_x_recv = 0; + hc->rx_pinv = ~0U; /* see RFC 4342, 8.5 */ break; - case TFRC_RSTATE_DATA: { - const u32 delta = timeval_delta(&now, - &hcrx->ccid3hcrx_tstamp_last_feedback); - hcrx->ccid3hcrx_x_recv = usecs_div(hcrx->ccid3hcrx_bytes_recv, - delta); - } + case CCID3_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 (hc->rx_x_recv > 0) + break; + /* fall through */ + case CCID3_FBACK_PERIODIC: + delta = ktime_us_delta(now, hc->rx_tstamp_last_feedback); + if (delta <= 0) + DCCP_BUG("delta (%ld) <= 0", (long)delta); + else + hc->rx_x_recv = scaled_div32(hc->rx_bytes_recv, delta); break; default: - printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n", - __FUNCTION__, dccp_role(sk), sk, hcrx->ccid3hcrx_state); - dump_stack(); return; } - packet = dccp_rx_hist_find_data_packet(&hcrx->ccid3hcrx_hist); - if (unlikely(packet == NULL)) { - LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, no data packet " - "in history!\n", - __FUNCTION__, dccp_role(sk), sk); - return; - } + ccid3_pr_debug("Interval %ldusec, X_recv=%u, 1/p=%u\n", (long)delta, + hc->rx_x_recv, hc->rx_pinv); - hcrx->ccid3hcrx_tstamp_last_feedback = now; - hcrx->ccid3hcrx_last_counter = packet->dccphrx_ccval; - hcrx->ccid3hcrx_seqno_last_counter = packet->dccphrx_seqno; - hcrx->ccid3hcrx_bytes_recv = 0; + hc->rx_tstamp_last_feedback = now; + hc->rx_last_counter = dccp_hdr(skb)->dccph_ccval; + hc->rx_bytes_recv = 0; - /* Convert to multiples of 10us */ - hcrx->ccid3hcrx_elapsed_time = - timeval_delta(&now, &packet->dccphrx_tstamp) / 10; - if (hcrx->ccid3hcrx_p == 0) - hcrx->ccid3hcrx_pinv = ~0; - else - hcrx->ccid3hcrx_pinv = 1000000 / hcrx->ccid3hcrx_p; dp->dccps_hc_rx_insert_options = 1; dccp_send_ack(sk); } -static void ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb) +static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb) { - const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); - u32 x_recv, pinv; - - BUG_ON(hcrx == NULL); + const struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); + __be32 x_recv, pinv; if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN)) - return; - - DCCP_SKB_CB(skb)->dccpd_ccval = hcrx->ccid3hcrx_last_counter; + return 0; if (dccp_packet_without_ack(skb)) - return; - - if (hcrx->ccid3hcrx_elapsed_time != 0) - dccp_insert_option_elapsed_time(sk, skb, - hcrx->ccid3hcrx_elapsed_time); - dccp_insert_option_timestamp(sk, skb); - x_recv = htonl(hcrx->ccid3hcrx_x_recv); - pinv = htonl(hcrx->ccid3hcrx_pinv); - 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 0; + + x_recv = htonl(hc->rx_x_recv); + pinv = htonl(hc->rx_pinv); + + if (dccp_insert_option(skb, TFRC_OPT_LOSS_EVENT_RATE, + &pinv, sizeof(pinv)) || + dccp_insert_option(skb, TFRC_OPT_RECEIVE_RATE, + &x_recv, sizeof(x_recv))) + return -1; + + return 0; } -/* calculate first loss interval +/** + * ccid3_first_li - Implements [RFC 5348, 6.3.1] * - * returns estimated loss interval in usecs */ - -static u32 ccid3_hc_rx_calc_first_li(struct sock *sk) + * 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 ccid3_first_li(struct sock *sk) { - struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); - struct dccp_rx_hist_entry *entry, *next, *tail = NULL; - u32 rtt, delta, x_recv, fval, p, tmp2; - struct timeval tstamp = { 0, }; - int interval = 0; - int win_count = 0; - int step = 0; - u64 tmp1; - - list_for_each_entry_safe(entry, next, &hcrx->ccid3hcrx_hist, - 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; - } - } - } + struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); + u32 x_recv, p, delta; + u64 fval; - if (unlikely(step == 0)) { - LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, packet history " - "contains no data packets!\n", - __FUNCTION__, dccp_role(sk), sk); - return ~0; + if (hc->rx_rtt == 0) { + DCCP_WARN("No RTT estimate available, using fallback RTT\n"); + hc->rx_rtt = DCCP_FALLBACK_RTT; } - if (unlikely(interval == 0)) { - LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, Could not find a " - "win_count interval > 0. Defaulting to 1\n", - __FUNCTION__, dccp_role(sk), sk); - interval = 1; + delta = ktime_to_us(net_timedelta(hc->rx_tstamp_last_feedback)); + x_recv = scaled_div32(hc->rx_bytes_recv, delta); + if (x_recv == 0) { /* would also trigger divide-by-zero */ + DCCP_WARN("X_recv==0\n"); + if (hc->rx_x_recv == 0) { + DCCP_BUG("stored value of X_recv is zero"); + return ~0U; + } + x_recv = hc->rx_x_recv; } -found: - rtt = timeval_delta(&tstamp, &tail->dccphrx_tstamp) * 4 / interval; - ccid3_pr_debug("%s, sk=%p, approximated RTT to %uus\n", - dccp_role(sk), sk, rtt); - if (rtt == 0) - rtt = 1; - - dccp_timestamp(sk, &tstamp); - delta = timeval_delta(&tstamp, &hcrx->ccid3hcrx_tstamp_last_feedback); - x_recv = usecs_div(hcrx->ccid3hcrx_bytes_recv, delta); - - tmp1 = (u64)x_recv * (u64)rtt; - do_div(tmp1,10000000); - tmp2 = (u32)tmp1; - fval = (hcrx->ccid3hcrx_s * 100000) / tmp2; - /* do not alter order above or you will get overflow on 32 bit */ - p = tfrc_calc_x_reverse_lookup(fval); - ccid3_pr_debug("%s, sk=%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, u64 seq_loss, u8 win_loss) -{ - struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); - - if (seq_loss != DCCP_MAX_SEQNO + 1 && - list_empty(&hcrx->ccid3hcrx_li_hist)) { - struct dccp_li_hist_entry *li_tail; - - li_tail = dccp_li_hist_interval_new(ccid3_li_hist, - &hcrx->ccid3hcrx_li_hist, - seq_loss, win_loss); - if (li_tail == NULL) - return; - li_tail->dccplih_interval = ccid3_hc_rx_calc_first_li(sk); - } else - LIMIT_NETDEBUG(KERN_WARNING "%s: FIXME: find end of " - "interval\n", __FUNCTION__); -} + fval = scaled_div(hc->rx_s, hc->rx_rtt); + fval = scaled_div32(fval, x_recv); + p = tfrc_calc_x_reverse_lookup(fval); -static void ccid3_hc_rx_detect_loss(struct sock *sk) -{ - struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); - u8 win_loss; - const u64 seq_loss = dccp_rx_hist_detect_loss(&hcrx->ccid3hcrx_hist, - &hcrx->ccid3hcrx_li_hist, - &win_loss); + ccid3_pr_debug("%s(%p), receive rate=%u bytes/s, implied " + "loss rate=%u\n", dccp_role(sk), sk, x_recv, p); - ccid3_hc_rx_update_li(sk, seq_loss, win_loss); + return p == 0 ? ~0U : scaled_div(1, p); } static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) { - struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); - const struct dccp_options_received *opt_recv; - struct dccp_rx_hist_entry *packet; - struct timeval now; - u8 win_count; - u32 p_prev, r_sample, t_elapsed; - int ins; - - BUG_ON(hcrx == NULL || - !(hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA || - hcrx->ccid3hcrx_state == TFRC_RSTATE_DATA)); - - opt_recv = &dccp_sk(sk)->dccps_options_received; - - switch (DCCP_SKB_CB(skb)->dccpd_type) { - case DCCP_PKT_ACK: - if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA) - return; - case DCCP_PKT_DATAACK: - if (opt_recv->dccpor_timestamp_echo == 0) - break; - p_prev = hcrx->ccid3hcrx_rtt; - dccp_timestamp(sk, &now); - timeval_sub_usecs(&now, opt_recv->dccpor_timestamp_echo * 10); - r_sample = timeval_usecs(&now); - t_elapsed = opt_recv->dccpor_elapsed_time * 10; - - if (unlikely(r_sample <= t_elapsed)) - LIMIT_NETDEBUG(KERN_WARNING "%s: r_sample=%uus, " - "t_elapsed=%uus\n", - __FUNCTION__, r_sample, t_elapsed); - else - r_sample -= t_elapsed; + struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); + enum ccid3_fback_type do_feedback = CCID3_FBACK_NONE; + const u64 ndp = dccp_sk(sk)->dccps_options_received.dccpor_ndp; + const bool is_data_packet = dccp_data_packet(skb); + + if (unlikely(hc->rx_state == TFRC_RSTATE_NO_DATA)) { + if (is_data_packet) { + const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; + do_feedback = CCID3_FBACK_INITIAL; + ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA); + hc->rx_s = payload; + /* + * Not necessary to update rx_bytes_recv here, + * since X_recv = 0 for the first feedback packet (cf. + * RFC 3448, 6.3) -- gerrit + */ + } + goto update_records; + } - if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA) - hcrx->ccid3hcrx_rtt = r_sample; - else - hcrx->ccid3hcrx_rtt = (hcrx->ccid3hcrx_rtt * 9) / 10 + - r_sample / 10; + if (tfrc_rx_hist_duplicate(&hc->rx_hist, skb)) + return; /* done receiving */ - if (p_prev != hcrx->ccid3hcrx_rtt) - ccid3_pr_debug("%s, New RTT=%luus, elapsed time=%u\n", - dccp_role(sk), hcrx->ccid3hcrx_rtt, - opt_recv->dccpor_elapsed_time); - break; - case DCCP_PKT_DATA: - break; - default: /* We're not interested in other packet types, move along */ - return; + if (is_data_packet) { + const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; + /* + * Update moving-average of s and the sum of received payload bytes + */ + hc->rx_s = tfrc_ewma(hc->rx_s, payload, 9); + hc->rx_bytes_recv += payload; } - packet = dccp_rx_hist_entry_new(ccid3_rx_hist, sk, opt_recv->dccpor_ndp, - skb, SLAB_ATOMIC); - if (unlikely(packet == NULL)) { - LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, Not enough mem to " - "add rx packet to history, consider it lost!\n", - __FUNCTION__, dccp_role(sk), sk); - return; + /* + * Perform loss detection and handle pending losses + */ + if (tfrc_rx_handle_loss(&hc->rx_hist, &hc->rx_li_hist, + skb, ndp, ccid3_first_li, sk)) { + do_feedback = CCID3_FBACK_PARAM_CHANGE; + goto done_receiving; } - win_count = packet->dccphrx_ccval; + if (tfrc_rx_hist_loss_pending(&hc->rx_hist)) + return; /* done receiving */ - ins = dccp_rx_hist_add_packet(ccid3_rx_hist, &hcrx->ccid3hcrx_hist, - &hcrx->ccid3hcrx_li_hist, packet); - - if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK) - return; + /* + * Handle data packets: RTT sampling and monitoring p + */ + if (unlikely(!is_data_packet)) + goto update_records; - switch (hcrx->ccid3hcrx_state) { - case TFRC_RSTATE_NO_DATA: - ccid3_pr_debug("%s, sk=%p(%s), skb=%p, sending initial " - "feedback\n", - dccp_role(sk), sk, - dccp_state_name(sk->sk_state), skb); - ccid3_hc_rx_send_feedback(sk); - ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA); - return; - case TFRC_RSTATE_DATA: - hcrx->ccid3hcrx_bytes_recv += skb->len - - dccp_hdr(skb)->dccph_doff * 4; - if (ins != 0) - break; + if (!tfrc_lh_is_initialised(&hc->rx_li_hist)) { + const u32 sample = tfrc_rx_hist_sample_rtt(&hc->rx_hist, skb); + /* + * 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. + */ + if (sample != 0) + hc->rx_rtt = tfrc_ewma(hc->rx_rtt, sample, 9); - dccp_timestamp(sk, &now); - if (timeval_delta(&now, &hcrx->ccid3hcrx_tstamp_last_ack) >= - hcrx->ccid3hcrx_rtt) { - hcrx->ccid3hcrx_tstamp_last_ack = now; - ccid3_hc_rx_send_feedback(sk); - } - return; - default: - printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n", - __FUNCTION__, dccp_role(sk), sk, hcrx->ccid3hcrx_state); - dump_stack(); - return; + } else if (tfrc_lh_update_i_mean(&hc->rx_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 = CCID3_FBACK_PARAM_CHANGE; } - /* Dealing with packet loss */ - ccid3_pr_debug("%s, sk=%p(%s), data loss! Reacting...\n", - dccp_role(sk), sk, dccp_state_name(sk->sk_state)); + /* + * Check if the periodic once-per-RTT feedback is due; RFC 4342, 10.3 + */ + if (SUB16(dccp_hdr(skb)->dccph_ccval, hc->rx_last_counter) > 3) + do_feedback = CCID3_FBACK_PERIODIC; - ccid3_hc_rx_detect_loss(sk); - p_prev = hcrx->ccid3hcrx_p; - - /* Calculate loss event rate */ - if (!list_empty(&hcrx->ccid3hcrx_li_hist)) - /* Scaling up by 1000000 as fixed decimal */ - hcrx->ccid3hcrx_p = 1000000 / dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist); +update_records: + tfrc_rx_hist_add_packet(&hc->rx_hist, skb, ndp); - if (hcrx->ccid3hcrx_p > p_prev) { - ccid3_hc_rx_send_feedback(sk); - return; - } +done_receiving: + if (do_feedback) + ccid3_hc_rx_send_feedback(sk, skb, do_feedback); } -static int ccid3_hc_rx_init(struct sock *sk) +static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk) { - struct dccp_sock *dp = dccp_sk(sk); - struct ccid3_hc_rx_sock *hcrx; - - ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk); - - dp->dccps_hc_rx_ccid_private = kmalloc(sizeof(*hcrx), gfp_any()); - if (dp->dccps_hc_rx_ccid_private == NULL) - return -ENOMEM; + struct ccid3_hc_rx_sock *hc = ccid_priv(ccid); - hcrx = ccid3_hc_rx_sk(sk); - memset(hcrx, 0, sizeof(*hcrx)); - - if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE && - dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE) - hcrx->ccid3hcrx_s = dp->dccps_packet_size; - else - hcrx->ccid3hcrx_s = TFRC_STD_PACKET_SIZE; - - hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA; - INIT_LIST_HEAD(&hcrx->ccid3hcrx_hist); - INIT_LIST_HEAD(&hcrx->ccid3hcrx_li_hist); - dccp_timestamp(sk, &hcrx->ccid3hcrx_tstamp_last_ack); - hcrx->ccid3hcrx_tstamp_last_feedback = hcrx->ccid3hcrx_tstamp_last_ack; - hcrx->ccid3hcrx_rtt = 5000; /* XXX 5ms for now... */ - return 0; + hc->rx_state = TFRC_RSTATE_NO_DATA; + tfrc_lh_init(&hc->rx_li_hist); + return tfrc_rx_hist_alloc(&hc->rx_hist); } static void ccid3_hc_rx_exit(struct sock *sk) { - struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); - struct dccp_sock *dp = dccp_sk(sk); - - BUG_ON(hcrx == NULL); - - ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM); - - /* Empty packet history */ - dccp_rx_hist_purge(ccid3_rx_hist, &hcrx->ccid3hcrx_hist); + struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); - /* Empty loss interval history */ - dccp_li_hist_purge(ccid3_li_hist, &hcrx->ccid3hcrx_li_hist); - - kfree(dp->dccps_hc_rx_ccid_private); - dp->dccps_hc_rx_ccid_private = NULL; + tfrc_rx_hist_purge(&hc->rx_hist); + tfrc_lh_cleanup(&hc->rx_li_hist); } static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info) { - const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); - - /* Listen socks doesn't have a private CCID block */ - if (sk->sk_state == DCCP_LISTEN) - return; - - BUG_ON(hcrx == NULL); - - info->tcpi_ca_state = hcrx->ccid3hcrx_state; - info->tcpi_options |= TCPI_OPT_TIMESTAMPS; - info->tcpi_rcv_rtt = hcrx->ccid3hcrx_rtt; -} - -static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info) -{ - const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); - - /* Listen socks doesn't have a private CCID block */ - if (sk->sk_state == DCCP_LISTEN) - return; - - BUG_ON(hctx == NULL); - - info->tcpi_rto = hctx->ccid3hctx_t_rto; - info->tcpi_rtt = hctx->ccid3hctx_rtt; + info->tcpi_ca_state = ccid3_hc_rx_sk(sk)->rx_state; + info->tcpi_options |= TCPI_OPT_TIMESTAMPS; + info->tcpi_rcv_rtt = ccid3_hc_rx_sk(sk)->rx_rtt; } static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len, u32 __user *optval, int __user *optlen) { - const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); + const struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); + struct tfrc_rx_info rx_info; 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_RX_INFO: - if (len < sizeof(hcrx->ccid3hcrx_tfrc)) + if (len < sizeof(rx_info)) return -EINVAL; - len = sizeof(hcrx->ccid3hcrx_tfrc); - val = &hcrx->ccid3hcrx_tfrc; + rx_info.tfrcrx_x_recv = hc->rx_x_recv; + rx_info.tfrcrx_rtt = hc->rx_rtt; + rx_info.tfrcrx_p = tfrc_invert_loss_event_rate(hc->rx_pinv); + len = sizeof(rx_info); + val = &rx_info; break; default: return -ENOPROTOOPT; @@ -1147,46 +843,17 @@ static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len, return 0; } -static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len, - u32 __user *optval, int __user *optlen) -{ - const struct ccid3_hc_tx_sock *hctx = ccid3_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->ccid3hctx_tfrc)) - return -EINVAL; - len = sizeof(hctx->ccid3hctx_tfrc); - val = &hctx->ccid3hctx_tfrc; - break; - default: - return -ENOPROTOOPT; - } - - if (put_user(len, optlen) || copy_to_user(optval, val, len)) - return -EFAULT; - - return 0; -} - -static struct ccid ccid3 = { - .ccid_id = 3, - .ccid_name = "ccid3", - .ccid_owner = THIS_MODULE, - .ccid_init = ccid3_init, - .ccid_exit = ccid3_exit, +struct ccid_operations ccid3_ops = { + .ccid_id = DCCPC_CCID3, + .ccid_name = "TCP-Friendly Rate Control", + .ccid_hc_tx_obj_size = sizeof(struct ccid3_hc_tx_sock), .ccid_hc_tx_init = ccid3_hc_tx_init, .ccid_hc_tx_exit = ccid3_hc_tx_exit, .ccid_hc_tx_send_packet = ccid3_hc_tx_send_packet, .ccid_hc_tx_packet_sent = ccid3_hc_tx_packet_sent, .ccid_hc_tx_packet_recv = ccid3_hc_tx_packet_recv, - .ccid_hc_tx_insert_options = ccid3_hc_tx_insert_options, .ccid_hc_tx_parse_options = ccid3_hc_tx_parse_options, + .ccid_hc_rx_obj_size = sizeof(struct ccid3_hc_rx_sock), .ccid_hc_rx_init = ccid3_hc_rx_init, .ccid_hc_rx_exit = ccid3_hc_rx_exit, .ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options, @@ -1196,75 +863,8 @@ static struct ccid ccid3 = { .ccid_hc_rx_getsockopt = ccid3_hc_rx_getsockopt, .ccid_hc_tx_getsockopt = ccid3_hc_tx_getsockopt, }; - -module_param(ccid3_debug, int, 0444); -MODULE_PARM_DESC(ccid3_debug, "Enable debug messages"); - -static __init int ccid3_module_init(void) -{ - int rc = -ENOBUFS; - - ccid3_rx_hist = dccp_rx_hist_new("ccid3"); - if (ccid3_rx_hist == NULL) - goto out; - - ccid3_tx_hist = dccp_tx_hist_new("ccid3"); - if (ccid3_tx_hist == NULL) - goto out_free_rx; - - ccid3_li_hist = dccp_li_hist_new("ccid3"); - if (ccid3_li_hist == NULL) - goto out_free_tx; - - rc = ccid_register(&ccid3); - if (rc != 0) - goto out_free_loss_interval_history; -out: - return rc; - -out_free_loss_interval_history: - dccp_li_hist_delete(ccid3_li_hist); - ccid3_li_hist = NULL; -out_free_tx: - dccp_tx_hist_delete(ccid3_tx_hist); - ccid3_tx_hist = NULL; -out_free_rx: - dccp_rx_hist_delete(ccid3_rx_hist); - ccid3_rx_hist = NULL; - goto out; -} -module_init(ccid3_module_init); -static __exit void ccid3_module_exit(void) -{ -#ifdef CONFIG_IP_DCCP_UNLOAD_HACK - /* - * Hack to use while developing, so that we get rid of the control - * sock, that is what keeps a refcount on dccp.ko -acme - */ - extern void dccp_ctl_sock_exit(void); - - dccp_ctl_sock_exit(); +#ifdef CONFIG_IP_DCCP_CCID3_DEBUG +module_param(ccid3_debug, bool, 0644); +MODULE_PARM_DESC(ccid3_debug, "Enable CCID-3 debug messages"); #endif - ccid_unregister(&ccid3); - - if (ccid3_tx_hist != NULL) { - dccp_tx_hist_delete(ccid3_tx_hist); - ccid3_tx_hist = NULL; - } - if (ccid3_rx_hist != NULL) { - dccp_rx_hist_delete(ccid3_rx_hist); - ccid3_rx_hist = NULL; - } - if (ccid3_li_hist != NULL) { - dccp_li_hist_delete(ccid3_li_hist); - ccid3_li_hist = NULL; - } -} -module_exit(ccid3_module_exit); - -MODULE_AUTHOR("Ian McDonald <iam4@cs.waikato.ac.nz>, " - "Arnaldo Carvalho de Melo <acme@ghostprotocols.net>"); -MODULE_DESCRIPTION("DCCP TFRC CCID3 CCID"); -MODULE_LICENSE("GPL"); -MODULE_ALIAS("net-dccp-ccid-3"); |