X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=net%2Fdccp%2Foutput.c;h=45b91853f5aee3d452d5795da832b9e1f04651ed;hb=82279e6bd7643da1b3fbda42555c3238c7b00d38;hp=a988fe9ffcbafdf74b6e90b24f4e8b8caa57591d;hpb=e430426654c6a99fb1977bae71d4844e876c4a52;p=karo-tx-linux.git diff --git a/net/dccp/output.c b/net/dccp/output.c index a988fe9ffcba..45b91853f5ae 100644 --- a/net/dccp/output.c +++ b/net/dccp/output.c @@ -209,108 +209,150 @@ void dccp_write_space(struct sock *sk) } /** - * dccp_wait_for_ccid - Wait for ccid to tell us we can send a packet + * dccp_wait_for_ccid - Await CCID send permission * @sk: socket to wait for - * @skb: current skb to pass on for waiting - * @delay: sleep timeout in milliseconds (> 0) - * This function is called by default when the socket is closed, and - * when a non-zero linger time is set on the socket. For consistency + * @delay: timeout in jiffies + * This is used by CCIDs which need to delay the send time in process context. */ -static int dccp_wait_for_ccid(struct sock *sk, struct sk_buff *skb, int delay) +static int dccp_wait_for_ccid(struct sock *sk, unsigned long delay) { - struct dccp_sock *dp = dccp_sk(sk); DEFINE_WAIT(wait); - unsigned long jiffdelay; - int rc; + long remaining; + + prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); + sk->sk_write_pending++; + release_sock(sk); + + remaining = schedule_timeout(delay); + + lock_sock(sk); + sk->sk_write_pending--; + finish_wait(sk_sleep(sk), &wait); + + if (signal_pending(current) || sk->sk_err) + return -1; + return remaining; +} + +/** + * 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 = skb_dequeue(&sk->sk_write_queue); - do { - dccp_pr_debug("delayed send by %d msec\n", delay); - jiffdelay = msecs_to_jiffies(delay); + if (unlikely(skb == NULL)) + return; + len = skb->len; - prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); + 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); + } - sk->sk_write_pending++; - release_sock(sk); - schedule_timeout(jiffdelay); - lock_sock(sk); - sk->sk_write_pending--; + 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 (sk->sk_err) - goto do_error; - if (signal_pending(current)) - goto do_interrupted; +/** + * dccp_flush_write_queue - Drain queue at end of connection + * Since dccp_sendmsg queues packets without waiting for them to be sent, it may + * happen that the TX queue is not empty at the end of a connection. We give the + * HC-sender CCID a grace period of up to @time_budget jiffies. If this function + * returns with a non-empty write queue, it will be purged later. + */ +void dccp_flush_write_queue(struct sock *sk, long *time_budget) +{ + struct dccp_sock *dp = dccp_sk(sk); + struct sk_buff *skb; + long delay, rc; + while (*time_budget > 0 && (skb = skb_peek(&sk->sk_write_queue))) { rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb); - } while ((delay = rc) > 0); -out: - finish_wait(sk_sleep(sk), &wait); - return rc; - -do_error: - rc = -EPIPE; - goto out; -do_interrupted: - rc = -EINTR; - goto out; + + switch (ccid_packet_dequeue_eval(rc)) { + case CCID_PACKET_WILL_DEQUEUE_LATER: + /* + * If the CCID determines when to send, the next sending + * time is unknown or the CCID may not even send again + * (e.g. remote host crashes or lost Ack packets). + */ + DCCP_WARN("CCID did not manage to send all packets\n"); + return; + case CCID_PACKET_DELAY: + delay = msecs_to_jiffies(rc); + if (delay > *time_budget) + return; + rc = dccp_wait_for_ccid(sk, delay); + if (rc < 0) + return; + *time_budget -= (delay - rc); + /* check again if we can send now */ + break; + case CCID_PACKET_SEND_AT_ONCE: + dccp_xmit_packet(sk); + break; + case CCID_PACKET_ERR: + skb_dequeue(&sk->sk_write_queue); + kfree_skb(skb); + dccp_pr_debug("packet discarded due to err=%ld\n", rc); + } + } } -void dccp_write_xmit(struct sock *sk, int block) +void dccp_write_xmit(struct sock *sk) { 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); - } + int rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb); - 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, 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); + switch (ccid_packet_dequeue_eval(rc)) { + case CCID_PACKET_WILL_DEQUEUE_LATER: + return; + case CCID_PACKET_DELAY: + sk_reset_timer(sk, &dp->dccps_xmit_timer, + jiffies + msecs_to_jiffies(rc)); + return; + case CCID_PACKET_SEND_AT_ONCE: + dccp_xmit_packet(sk); + break; + case CCID_PACKET_ERR: + skb_dequeue(&sk->sk_write_queue); kfree_skb(skb); + dccp_pr_debug("packet discarded due to err=%d\n", rc); } } } @@ -622,7 +664,6 @@ void dccp_send_close(struct sock *sk, const int active) DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_CLOSE; if (active) { - dccp_write_xmit(sk, 1); dccp_skb_entail(sk, skb); dccp_transmit_skb(sk, skb_clone(skb, prio)); /*