diff options
Diffstat (limited to 'net/dccp/ccids/ccid3.c')
| -rw-r--r-- | net/dccp/ccids/ccid3.c | 322 |
1 files changed, 160 insertions, 162 deletions
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index 746f79d..d7d9ce7 100644 --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c @@ -33,7 +33,6 @@ * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ - #include "../ccid.h" #include "../dccp.h" #include "lib/packet_history.h" @@ -52,6 +51,9 @@ static struct dccp_tx_hist *ccid3_tx_hist; static struct dccp_rx_hist *ccid3_rx_hist; static struct dccp_li_hist *ccid3_li_hist; +/* + * Transmitter Half-Connection Routines + */ #ifdef CONFIG_IP_DCCP_CCID3_DEBUG static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state) { @@ -80,23 +82,37 @@ static void ccid3_hc_tx_set_state(struct sock *sk, } /* - * Recalculate scheduled nominal send time t_nom, inter-packet interval - * t_ipi, and delta value. Should be called after each change to X. + * Compute the initial sending rate X_init according to RFC 3390: + * w_init = min(4 * MSS, max(2 * MSS, 4380 bytes)) + * X_init = w_init / RTT + * For consistency with other parts of the code, X_init is scaled by 2^6. */ -static inline void ccid3_update_send_time(struct ccid3_hc_tx_sock *hctx) +static inline u64 rfc3390_initial_rate(struct sock *sk) { - timeval_sub_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi); + const struct dccp_sock *dp = dccp_sk(sk); + const __u32 w_init = min(4 * dp->dccps_mss_cache, + max(2 * dp->dccps_mss_cache, 4380U)); - /* Calculate new t_ipi = s / X_inst (X_inst is in 64 * bytes/second) */ - hctx->ccid3hctx_t_ipi = scaled_div(hctx->ccid3hctx_s, - hctx->ccid3hctx_x >> 6); + return scaled_div(w_init << 6, ccid3_hc_tx_sk(sk)->ccid3hctx_rtt); +} - /* Update nominal send time with regard to the new t_ipi */ - timeval_add_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi); +/* + * Recalculate t_ipi and delta (should be called whenever X changes) + */ +static inline void ccid3_update_send_interval(struct ccid3_hc_tx_sock *hctx) +{ + /* Calculate new t_ipi = s / X_inst (X_inst is in 64 * bytes/second) */ + hctx->ccid3hctx_t_ipi = scaled_div32(((u64)hctx->ccid3hctx_s) << 6, + hctx->ccid3hctx_x); /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */ hctx->ccid3hctx_delta = min_t(u32, hctx->ccid3hctx_t_ipi / 2, TFRC_OPSYS_HALF_TIME_GRAN); + + ccid3_pr_debug("t_ipi=%u, delta=%u, s=%u, X=%u\n", + hctx->ccid3hctx_t_ipi, hctx->ccid3hctx_delta, + hctx->ccid3hctx_s, (unsigned)(hctx->ccid3hctx_x >> 6)); + } /* * Update X by @@ -112,19 +128,28 @@ static inline void ccid3_update_send_time(struct ccid3_hc_tx_sock *hctx) * fine-grained resolution of sending rates. This requires scaling by 2^6 * throughout the code. Only X_calc is unscaled (in bytes/second). * - * If X has changed, we also update the scheduled send time t_now, - * the inter-packet interval t_ipi, and the delta value. */ static void ccid3_hc_tx_update_x(struct sock *sk, struct timeval *now) { struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); + __u64 min_rate = 2 * hctx->ccid3hctx_x_recv; const __u64 old_x = hctx->ccid3hctx_x; + /* + * Handle IDLE periods: do not reduce below RFC3390 initial sending rate + * when idling [RFC 4342, 5.1]. See also draft-ietf-dccp-rfc3448bis. + * For consistency with X and X_recv, min_rate is also scaled by 2^6. + */ + if (unlikely(hctx->ccid3hctx_idle)) { + min_rate = rfc3390_initial_rate(sk); + min_rate = max(min_rate, 2 * hctx->ccid3hctx_x_recv); + } + if (hctx->ccid3hctx_p > 0) { hctx->ccid3hctx_x = min(((__u64)hctx->ccid3hctx_x_calc) << 6, - hctx->ccid3hctx_x_recv * 2); + min_rate); hctx->ccid3hctx_x = max(hctx->ccid3hctx_x, (((__u64)hctx->ccid3hctx_s) << 6) / TFRC_T_MBI); @@ -133,14 +158,21 @@ static void ccid3_hc_tx_update_x(struct sock *sk, struct timeval *now) (suseconds_t)hctx->ccid3hctx_rtt >= 0) { hctx->ccid3hctx_x = - max(2 * min(hctx->ccid3hctx_x, hctx->ccid3hctx_x_recv), + max(min(2 * hctx->ccid3hctx_x, min_rate), scaled_div(((__u64)hctx->ccid3hctx_s) << 6, hctx->ccid3hctx_rtt)); hctx->ccid3hctx_t_ld = *now; } - if (hctx->ccid3hctx_x != old_x) - ccid3_update_send_time(hctx); + if (hctx->ccid3hctx_x != old_x) { + ccid3_pr_debug("X_prev=%u, X_now=%u, X_calc=%u, " + "X_recv=%u\n", (unsigned)(old_x >> 6), + (unsigned)(hctx->ccid3hctx_x >> 6), + hctx->ccid3hctx_x_calc, + (unsigned)(hctx->ccid3hctx_x_recv >> 6)); + + ccid3_update_send_interval(hctx); + } } /* @@ -149,17 +181,12 @@ static void ccid3_hc_tx_update_x(struct sock *sk, struct timeval *now) */ static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hctx, int len) { - if (unlikely(len == 0)) - ccid3_pr_debug("Packet payload length is 0 - not updating\n"); - else - hctx->ccid3hctx_s = hctx->ccid3hctx_s == 0 ? len : - (9 * hctx->ccid3hctx_s + len) / 10; - /* - * Note: We could do a potential optimisation here - when `s' changes, - * recalculate sending rate and consequently t_ipi, t_delta, and - * t_now. This is however non-standard, and the benefits are not - * clear, so it is currently left out. - */ + const u16 old_s = hctx->ccid3hctx_s; + + hctx->ccid3hctx_s = old_s == 0 ? len : (9 * old_s + len) / 10; + + if (hctx->ccid3hctx_s != old_s) + ccid3_update_send_interval(hctx); } /* @@ -193,6 +220,7 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data) { struct sock *sk = (struct sock *)data; struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); + struct timeval now; unsigned long t_nfb = USEC_PER_SEC / 5; bh_lock_sock(sk); @@ -205,6 +233,8 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data) ccid3_pr_debug("%s(%p, state=%s) - entry \n", dccp_role(sk), sk, ccid3_tx_state_name(hctx->ccid3hctx_state)); + hctx->ccid3hctx_idle = 1; + switch (hctx->ccid3hctx_state) { case TFRC_SSTATE_NO_FBACK: /* RFC 3448, 4.4: Halve send rate directly */ @@ -219,53 +249,37 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data) /* The value of R is still undefined and so we can not recompute * the timout value. Keep initial value as per [RFC 4342, 5]. */ t_nfb = TFRC_INITIAL_TIMEOUT; - ccid3_update_send_time(hctx); + ccid3_update_send_interval(hctx); break; case TFRC_SSTATE_FBACK: /* - * Check if IDLE since last timeout and recv rate is less than - * 4 packets (in units of 64*bytes/sec) per RTT + * Modify the cached value of X_recv [RFC 3448, 4.4] + * + * If (p == 0 || 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 * - scaled_div(((__u64)hctx->ccid3hctx_s) << 6, - hctx->ccid3hctx_rtt))) { - struct timeval now; + BUG_ON(hctx->ccid3hctx_p && !hctx->ccid3hctx_x_calc); - ccid3_pr_debug("%s(%p, state=%s), not idle\n", - dccp_role(sk), sk, - ccid3_tx_state_name(hctx->ccid3hctx_state)); + if (hctx->ccid3hctx_p == 0 || + (hctx->ccid3hctx_x_calc > (hctx->ccid3hctx_x_recv >> 5))) { - /* - * Modify the cached value of X_recv [RFC 3448, 4.4] - * - * If (p == 0 || 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->ccid3hctx_p && !hctx->ccid3hctx_x_calc); - - if (hctx->ccid3hctx_p == 0 || - (hctx->ccid3hctx_x_calc > - (hctx->ccid3hctx_x_recv >> 5))) { - - hctx->ccid3hctx_x_recv = - max(hctx->ccid3hctx_x_recv / 2, - (((__u64)hctx->ccid3hctx_s) << 6) / - (2 * TFRC_T_MBI)); - - if (hctx->ccid3hctx_p == 0) - dccp_timestamp(sk, &now); - } else { - hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc; - hctx->ccid3hctx_x_recv <<= 4; - } - /* Now recalculate X [RFC 3448, 4.3, step (4)] */ - ccid3_hc_tx_update_x(sk, &now); + hctx->ccid3hctx_x_recv = + max(hctx->ccid3hctx_x_recv / 2, + (((__u64)hctx->ccid3hctx_s) << 6) / + (2 * TFRC_T_MBI)); + + if (hctx->ccid3hctx_p == 0) + dccp_timestamp(sk, &now); + } else { + hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc; + hctx->ccid3hctx_x_recv <<= 4; } + /* Now recalculate X [RFC 3448, 4.3, step (4)] */ + ccid3_hc_tx_update_x(sk, &now); /* * Schedule no feedback timer to expire in * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi) @@ -280,8 +294,6 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data) goto out; } - hctx->ccid3hctx_idle = 1; - restart_timer: sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, jiffies + usecs_to_jiffies(t_nfb)); @@ -322,24 +334,35 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) 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); - - /* Set initial sending rate X/s to 1pps (X is scaled by 2^6) */ - ccid3_hc_tx_update_s(hctx, skb->len); - hctx->ccid3hctx_x = hctx->ccid3hctx_s; - hctx->ccid3hctx_x <<= 6; - - /* First timeout, according to [RFC 3448, 4.2], is 1 second */ - hctx->ccid3hctx_t_ipi = USEC_PER_SEC; - /* Initial delta: minimum of 0.5 sec and t_gran/2 */ - hctx->ccid3hctx_delta = TFRC_OPSYS_HALF_TIME_GRAN; /* Set t_0 for initial packet */ hctx->ccid3hctx_t_nom = now; + + hctx->ccid3hctx_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); + hctx->ccid3hctx_rtt = dp->dccps_syn_rtt; + hctx->ccid3hctx_x = rfc3390_initial_rate(sk); + hctx->ccid3hctx_t_ld = now; + } else { + /* Sender does not have RTT sample: X = MSS/second */ + hctx->ccid3hctx_x = dp->dccps_mss_cache; + hctx->ccid3hctx_x <<= 6; + } + ccid3_update_send_interval(hctx); + + ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); break; case TFRC_SSTATE_NO_FBACK: case TFRC_SSTATE_FBACK: delay = timeval_delta(&hctx->ccid3hctx_t_nom, &now); + ccid3_pr_debug("delay=%ld\n", (long)delay); /* * Scheduling of packet transmissions [RFC 3448, 4.6] * @@ -361,6 +384,7 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) /* prepare to send now (add options etc.) */ dp->dccps_hc_tx_insert_options = 1; DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count; + hctx->ccid3hctx_idle = 0; /* set the nominal send time for the next following packet */ timeval_add_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi); @@ -391,7 +415,6 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, packet->dccphtx_seqno = dccp_sk(sk)->dccps_gss; packet->dccphtx_rtt = hctx->ccid3hctx_rtt; packet->dccphtx_sent = 1; - hctx->ccid3hctx_idle = 0; } static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) @@ -402,8 +425,7 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) struct dccp_tx_hist_entry *packet; struct timeval now; unsigned long t_nfb; - u32 pinv; - suseconds_t r_sample, t_elapsed; + u32 pinv, r_sample; BUG_ON(hctx == NULL); @@ -445,18 +467,10 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) * Calculate new round trip sample as per [RFC 3448, 4.3] by * R_sample = (now - t_recvdata) - t_elapsed */ - r_sample = timeval_delta(&now, &packet->dccphtx_tstamp); - t_elapsed = dp->dccps_options_received.dccpor_elapsed_time * 10; - - DCCP_BUG_ON(r_sample < 0); - if (unlikely(r_sample <= t_elapsed)) - DCCP_WARN("WARNING: r_sample=%dus <= t_elapsed=%dus\n", - (int)r_sample, (int)t_elapsed); - else - r_sample -= t_elapsed; - CCID3_RTT_SANITY_CHECK(r_sample); + r_sample = dccp_sample_rtt(sk, &now, &packet->dccphtx_tstamp); - /* Update RTT estimate by + /* + * Update RTT estimate by * If (No feedback recv) * R = R_sample; * Else @@ -467,27 +481,23 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) { /* * Larger Initial Windows [RFC 4342, sec. 5] - * We deviate in that we use `s' instead of `MSS'. */ - __u64 w_init = min(4 * hctx->ccid3hctx_s, - max(2 * hctx->ccid3hctx_s, 4380)); hctx->ccid3hctx_rtt = r_sample; - hctx->ccid3hctx_x = scaled_div(w_init << 6, r_sample); + hctx->ccid3hctx_x = rfc3390_initial_rate(sk); hctx->ccid3hctx_t_ld = now; - ccid3_update_send_time(hctx); + ccid3_update_send_interval(hctx); - ccid3_pr_debug("%s(%p), s=%u, w_init=%llu, " - "R_sample=%dus, X=%u\n", dccp_role(sk), + ccid3_pr_debug("%s(%p), s=%u, MSS=%u, " + "R_sample=%uus, X=%u\n", dccp_role(sk), sk, hctx->ccid3hctx_s, - (unsigned long long)w_init, - (int)r_sample, + dp->dccps_mss_cache, r_sample, (unsigned)(hctx->ccid3hctx_x >> 6)); ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK); } else { hctx->ccid3hctx_rtt = (9 * hctx->ccid3hctx_rtt + - (u32)r_sample) / 10; + r_sample) / 10; /* Update sending rate (step 4 of [RFC 3448, 4.3]) */ if (hctx->ccid3hctx_p > 0) @@ -497,10 +507,10 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) hctx->ccid3hctx_p); ccid3_hc_tx_update_x(sk, &now); - ccid3_pr_debug("%s(%p), RTT=%uus (sample=%dus), s=%u, " + 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, hctx->ccid3hctx_rtt, (int)r_sample, + sk, hctx->ccid3hctx_rtt, r_sample, hctx->ccid3hctx_s, hctx->ccid3hctx_p, hctx->ccid3hctx_x_calc, (unsigned)(hctx->ccid3hctx_x_recv >> 6), @@ -644,10 +654,50 @@ static void ccid3_hc_tx_exit(struct sock *sk) dccp_tx_hist_purge(ccid3_tx_hist, &hctx->ccid3hctx_hist); } +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; +} + +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; +} + /* - * RX Half Connection methods + * Receiver Half-Connection Routines */ - #ifdef CONFIG_IP_DCCP_CCID3_DEBUG static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state) { @@ -977,8 +1027,7 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) const struct dccp_options_received *opt_recv; struct dccp_rx_hist_entry *packet; struct timeval now; - u32 p_prev, rtt_prev; - suseconds_t r_sample, t_elapsed; + u32 p_prev, r_sample, rtt_prev; int loss, payload_size; BUG_ON(hcrx == NULL); @@ -994,17 +1043,7 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) break; rtt_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; - - DCCP_BUG_ON(r_sample < 0); - if (unlikely(r_sample <= t_elapsed)) - DCCP_WARN("r_sample=%ldus, t_elapsed=%ldus\n", - (long)r_sample, (long)t_elapsed); - else - r_sample -= t_elapsed; - CCID3_RTT_SANITY_CHECK(r_sample); + r_sample = dccp_sample_rtt(sk, &now, NULL); if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA) hcrx->ccid3hcrx_rtt = r_sample; @@ -1132,20 +1171,6 @@ static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info) 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; -} - static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len, u32 __user *optval, int __user *optlen) { @@ -1173,33 +1198,6 @@ 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_operations ccid3 = { .ccid_id = DCCPC_CCID3, .ccid_name = "ccid3", |
