/* FIXME: Is this still necessary (11.3) - currently nowhere used by DCCP. */ void dccp_send_delayed_ack(struct sock *sk) { struct inet_connection_sock *icsk = inet_csk(sk); /* * FIXME: tune this timer. elapsed time fixes the skew, so no problem * with using 2s, and active senders also piggyback the ACK into a * DATAACK packet, so this is really for quiescent senders. */ unsigned long timeout = jiffies + 2 * HZ; /* Use new timeout only if there wasn't a older one earlier. */ if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) { /* If delack timer was blocked or is about to expire, * send ACK now. * * FIXME: check the "about to expire" part */ if (icsk->icsk_ack.blocked) { dccp_send_ack(sk); return; } if (!time_before(timeout, icsk->icsk_ack.timeout)) timeout = icsk->icsk_ack.timeout; } icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER; icsk->icsk_ack.timeout = timeout; sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout); }
void dccp_write_xmit(struct sock *sk, int block) { struct dccp_sock *dp = dccp_sk(sk); struct sk_buff *skb; while ((skb = skb_peek(&sk->sk_write_queue))) { int err = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb); if (err > 0) { if (!block) { sk_reset_timer(sk, &dp->dccps_xmit_timer, msecs_to_jiffies(err)+jiffies); break; } else err = dccp_wait_for_ccid(sk, skb, err); if (err && err != -EINTR) DCCP_BUG("err=%d after dccp_wait_for_ccid", err); } skb_dequeue(&sk->sk_write_queue); if (err == 0) { struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); const int len = skb->len; if (sk->sk_state == DCCP_PARTOPEN) { const u32 cur_mps = dp->dccps_mss_cache - DCCP_FEATNEG_OVERHEAD; /* * See 8.1.5 - Handshake Completion. * * For robustness we resend Confirm options until the client has * entered OPEN. During the initial feature negotiation, the MPS * is smaller than usual, reduced by the Change/Confirm options. */ if (!list_empty(&dp->dccps_featneg) && len > cur_mps) { DCCP_WARN("Payload too large (%d) for featneg.\n", len); dccp_send_ack(sk); dccp_feat_list_purge(&dp->dccps_featneg); } inet_csk_schedule_ack(sk); inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, inet_csk(sk)->icsk_rto, DCCP_RTO_MAX); dcb->dccpd_type = DCCP_PKT_DATAACK; } else if (dccp_ack_pending(sk)) dcb->dccpd_type = DCCP_PKT_DATAACK; else dcb->dccpd_type = DCCP_PKT_DATA; err = dccp_transmit_skb(sk, skb); ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, 0, len); if (err) DCCP_BUG("err=%d after ccid_hc_tx_packet_sent", err); } else { dccp_pr_debug("packet discarded due to err=%d\n", err); kfree_skb(skb); } } }
/** * dccp_xmit_packet - Send data packet under control of CCID * Transmits next-queued payload and informs CCID to account for the packet. */ static void dccp_xmit_packet(struct sock *sk) { int err, len; struct dccp_sock *dp = dccp_sk(sk); struct sk_buff *skb = dccp_qpolicy_pop(sk); if (unlikely(skb == NULL)) return; len = skb->len; if (sk->sk_state == DCCP_PARTOPEN) { const u32 cur_mps = dp->dccps_mss_cache - DCCP_FEATNEG_OVERHEAD; /* * See 8.1.5 - Handshake Completion. * * For robustness we resend Confirm options until the client has * entered OPEN. During the initial feature negotiation, the MPS * is smaller than usual, reduced by the Change/Confirm options. */ if (!list_empty(&dp->dccps_featneg) && len > cur_mps) { DCCP_WARN("Payload too large (%d) for featneg.\n", len); dccp_send_ack(sk); dccp_feat_list_purge(&dp->dccps_featneg); } inet_csk_schedule_ack(sk); inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, inet_csk(sk)->icsk_rto, DCCP_RTO_MAX); DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_DATAACK; } else if (dccp_ack_pending(sk)) { DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_DATAACK; } else { DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_DATA; } err = dccp_transmit_skb(sk, skb); if (err) dccp_pr_debug("transmit_skb() returned err=%d\n", err); /* * Register this one as sent even if an error occurred. To the remote * end a local packet drop is indistinguishable from network loss, i.e. * any local drop will eventually be reported via receiver feedback. */ ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, len); /* * If the CCID needs to transfer additional header options out-of-band * (e.g. Ack Vectors or feature-negotiation options), it activates this * flag to schedule a Sync. The Sync will automatically incorporate all * currently pending header options, thus clearing the backlog. */ if (dp->dccps_sync_scheduled) dccp_send_sync(sk, dp->dccps_gsr, DCCP_PKT_SYNC); }
void dccp_write_xmit(struct sock *sk, int block) { struct dccp_sock *dp = dccp_sk(sk); struct sk_buff *skb; while ((skb = skb_peek(&sk->sk_write_queue))) { int err = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb); if (err > 0) { if (!block) { sk_reset_timer(sk, &dp->dccps_xmit_timer, msecs_to_jiffies(err)+jiffies); break; } else err = dccp_wait_for_ccid(sk, skb, err); if (err && err != -EINTR) DCCP_BUG("err=%d after dccp_wait_for_ccid", err); } skb_dequeue(&sk->sk_write_queue); if (err == 0) { struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); const int len = skb->len; if (sk->sk_state == DCCP_PARTOPEN) { const u32 cur_mps = dp->dccps_mss_cache - DCCP_FEATNEG_OVERHEAD; if (!list_empty(&dp->dccps_featneg) && len > cur_mps) { DCCP_WARN("Payload too large (%d) for featneg.\n", len); dccp_send_ack(sk); dccp_feat_list_purge(&dp->dccps_featneg); } inet_csk_schedule_ack(sk); inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, inet_csk(sk)->icsk_rto, DCCP_RTO_MAX); dcb->dccpd_type = DCCP_PKT_DATAACK; } else if (dccp_ack_pending(sk)) dcb->dccpd_type = DCCP_PKT_DATAACK; else dcb->dccpd_type = DCCP_PKT_DATA; err = dccp_transmit_skb(sk, skb); ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, 0, len); if (err) DCCP_BUG("err=%d after ccid_hc_tx_packet_sent", err); } else { dccp_pr_debug("packet discarded due to err=%d\n", err); kfree_skb(skb); } } }
void dccp_send_delayed_ack(struct sock *sk) { struct inet_connection_sock *icsk = inet_csk(sk); unsigned long timeout = jiffies + 2 * HZ; if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) { if (icsk->icsk_ack.blocked) { dccp_send_ack(sk); return; } if (!time_before(timeout, icsk->icsk_ack.timeout)) timeout = icsk->icsk_ack.timeout; } icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER; icsk->icsk_ack.timeout = timeout; sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout); }
static int dccp_rcv_request_sent_state_process(struct sock *sk, struct sk_buff *skb, const struct dccp_hdr *dh, const unsigned len) { /* * Step 4: Prepare sequence numbers in REQUEST * If S.state == REQUEST, * If (P.type == Response or P.type == Reset) * and S.AWL <= P.ackno <= S.AWH, * / * Set sequence number variables corresponding to the * other endpoint, so P will pass the tests in Step 6 * / * Set S.GSR, S.ISR, S.SWL, S.SWH * / * Response processing continues in Step 10; Reset * processing continues in Step 9 * / */ if (dh->dccph_type == DCCP_PKT_RESPONSE) { const struct inet_connection_sock *icsk = inet_csk(sk); struct dccp_sock *dp = dccp_sk(sk); /* Stop the REQUEST timer */ inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS); BUG_TRAP(sk->sk_send_head != NULL); __kfree_skb(sk->sk_send_head); sk->sk_send_head = NULL; if (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq, dp->dccps_awl, dp->dccps_awh)) { dccp_pr_debug("invalid ackno: S.AWL=%llu, " "P.ackno=%llu, S.AWH=%llu \n", (unsigned long long)dp->dccps_awl, (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq, (unsigned long long)dp->dccps_awh); goto out_invalid_packet; } if (dccp_parse_options(sk, skb)) goto out_invalid_packet; if (dccp_msk(sk)->dccpms_send_ack_vector && dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_ACKVEC_STATE_RECEIVED)) goto out_invalid_packet; /* FIXME: change error code */ dp->dccps_isr = DCCP_SKB_CB(skb)->dccpd_seq; dccp_update_gsr(sk, dp->dccps_isr); /* * SWL and AWL are initially adjusted so that they are not less than * the initial Sequence Numbers received and sent, respectively: * SWL := max(GSR + 1 - floor(W/4), ISR), * AWL := max(GSS - W' + 1, ISS). * These adjustments MUST be applied only at the beginning of the * connection. * * AWL was adjusted in dccp_v4_connect -acme */ dccp_set_seqno(&dp->dccps_swl, max48(dp->dccps_swl, dp->dccps_isr)); dccp_sync_mss(sk, icsk->icsk_pmtu_cookie); /* * Step 10: Process REQUEST state (second part) * If S.state == REQUEST, * / * If we get here, P is a valid Response from the * server (see Step 4), and we should move to * PARTOPEN state. PARTOPEN means send an Ack, * don't send Data packets, retransmit Acks * periodically, and always include any Init Cookie * from the Response * / * S.state := PARTOPEN * Set PARTOPEN timer * Continue with S.state == PARTOPEN * / * Step 12 will send the Ack completing the * three-way handshake * / */ dccp_set_state(sk, DCCP_PARTOPEN); /* Make sure socket is routed, for correct metrics. */ icsk->icsk_af_ops->rebuild_header(sk); if (!sock_flag(sk, SOCK_DEAD)) { sk->sk_state_change(sk); sk_wake_async(sk, 0, POLL_OUT); } if (sk->sk_write_pending || icsk->icsk_ack.pingpong || icsk->icsk_accept_queue.rskq_defer_accept) { /* Save one ACK. Data will be ready after * several ticks, if write_pending is set. * * It may be deleted, but with this feature tcpdumps * look so _wonderfully_ clever, that I was not able * to stand against the temptation 8) --ANK */ /* * OK, in DCCP we can as well do a similar trick, its * even in the draft, but there is no need for us to * schedule an ack here, as dccp_sendmsg does this for * us, also stated in the draft. -acme */ __kfree_skb(skb); return 0; } dccp_send_ack(sk); return -1; } out_invalid_packet: /* dccp_v4_do_rcv will send a reset */ DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR; return 1; }