summaryrefslogtreecommitdiff
path: root/net/dccp/output.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/dccp/output.c')
-rw-r--r--net/dccp/output.c708
1 files changed, 0 insertions, 708 deletions
diff --git a/net/dccp/output.c b/net/dccp/output.c
deleted file mode 100644
index 39cf3430177a..000000000000
--- a/net/dccp/output.c
+++ /dev/null
@@ -1,708 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * net/dccp/output.c
- *
- * An implementation of the DCCP protocol
- * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
- */
-
-#include <linux/dccp.h>
-#include <linux/kernel.h>
-#include <linux/skbuff.h>
-#include <linux/slab.h>
-#include <linux/sched/signal.h>
-
-#include <net/inet_sock.h>
-#include <net/sock.h>
-
-#include "ackvec.h"
-#include "ccid.h"
-#include "dccp.h"
-
-static inline void dccp_event_ack_sent(struct sock *sk)
-{
- inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
-}
-
-/* enqueue @skb on sk_send_head for retransmission, return clone to send now */
-static struct sk_buff *dccp_skb_entail(struct sock *sk, struct sk_buff *skb)
-{
- skb_set_owner_w(skb, sk);
- WARN_ON(sk->sk_send_head);
- sk->sk_send_head = skb;
- return skb_clone(sk->sk_send_head, gfp_any());
-}
-
-/*
- * All SKB's seen here are completely headerless. It is our
- * job to build the DCCP header, and pass the packet down to
- * IP so it can do the same plus pass the packet off to the
- * device.
- */
-static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
-{
- if (likely(skb != NULL)) {
- struct inet_sock *inet = inet_sk(sk);
- const struct inet_connection_sock *icsk = inet_csk(sk);
- struct dccp_sock *dp = dccp_sk(sk);
- struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
- struct dccp_hdr *dh;
- /* XXX For now we're using only 48 bits sequence numbers */
- const u32 dccp_header_size = sizeof(*dh) +
- sizeof(struct dccp_hdr_ext) +
- dccp_packet_hdr_len(dcb->dccpd_type);
- int err, set_ack = 1;
- u64 ackno = dp->dccps_gsr;
- /*
- * Increment GSS here already in case the option code needs it.
- * Update GSS for real only if option processing below succeeds.
- */
- dcb->dccpd_seq = ADD48(dp->dccps_gss, 1);
-
- switch (dcb->dccpd_type) {
- case DCCP_PKT_DATA:
- set_ack = 0;
- fallthrough;
- case DCCP_PKT_DATAACK:
- case DCCP_PKT_RESET:
- break;
-
- case DCCP_PKT_REQUEST:
- set_ack = 0;
- /* Use ISS on the first (non-retransmitted) Request. */
- if (icsk->icsk_retransmits == 0)
- dcb->dccpd_seq = dp->dccps_iss;
- fallthrough;
-
- case DCCP_PKT_SYNC:
- case DCCP_PKT_SYNCACK:
- ackno = dcb->dccpd_ack_seq;
- fallthrough;
- default:
- /*
- * Set owner/destructor: some skbs are allocated via
- * alloc_skb (e.g. when retransmission may happen).
- * Only Data, DataAck, and Reset packets should come
- * through here with skb->sk set.
- */
- WARN_ON(skb->sk);
- skb_set_owner_w(skb, sk);
- break;
- }
-
- if (dccp_insert_options(sk, skb)) {
- kfree_skb(skb);
- return -EPROTO;
- }
-
-
- /* Build DCCP header and checksum it. */
- dh = dccp_zeroed_hdr(skb, dccp_header_size);
- dh->dccph_type = dcb->dccpd_type;
- dh->dccph_sport = inet->inet_sport;
- dh->dccph_dport = inet->inet_dport;
- dh->dccph_doff = (dccp_header_size + dcb->dccpd_opt_len) / 4;
- dh->dccph_ccval = dcb->dccpd_ccval;
- dh->dccph_cscov = dp->dccps_pcslen;
- /* XXX For now we're using only 48 bits sequence numbers */
- dh->dccph_x = 1;
-
- dccp_update_gss(sk, dcb->dccpd_seq);
- dccp_hdr_set_seq(dh, dp->dccps_gss);
- if (set_ack)
- dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), ackno);
-
- switch (dcb->dccpd_type) {
- case DCCP_PKT_REQUEST:
- dccp_hdr_request(skb)->dccph_req_service =
- dp->dccps_service;
- /*
- * Limit Ack window to ISS <= P.ackno <= GSS, so that
- * only Responses to Requests we sent are considered.
- */
- dp->dccps_awl = dp->dccps_iss;
- break;
- case DCCP_PKT_RESET:
- dccp_hdr_reset(skb)->dccph_reset_code =
- dcb->dccpd_reset_code;
- break;
- }
-
- icsk->icsk_af_ops->send_check(sk, skb);
-
- if (set_ack)
- dccp_event_ack_sent(sk);
-
- DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
-
- err = icsk->icsk_af_ops->queue_xmit(sk, skb, &inet->cork.fl);
- return net_xmit_eval(err);
- }
- return -ENOBUFS;
-}
-
-/**
- * dccp_determine_ccmps - Find out about CCID-specific packet-size limits
- * @dp: socket to find packet size limits of
- *
- * We only consider the HC-sender CCID for setting the CCMPS (RFC 4340, 14.),
- * since the RX CCID is restricted to feedback packets (Acks), which are small
- * in comparison with the data traffic. A value of 0 means "no current CCMPS".
- */
-static u32 dccp_determine_ccmps(const struct dccp_sock *dp)
-{
- const struct ccid *tx_ccid = dp->dccps_hc_tx_ccid;
-
- if (tx_ccid == NULL || tx_ccid->ccid_ops == NULL)
- return 0;
- return tx_ccid->ccid_ops->ccid_ccmps;
-}
-
-unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu)
-{
- struct inet_connection_sock *icsk = inet_csk(sk);
- struct dccp_sock *dp = dccp_sk(sk);
- u32 ccmps = dccp_determine_ccmps(dp);
- u32 cur_mps = ccmps ? min(pmtu, ccmps) : pmtu;
-
- /* Account for header lengths and IPv4/v6 option overhead */
- cur_mps -= (icsk->icsk_af_ops->net_header_len + icsk->icsk_ext_hdr_len +
- sizeof(struct dccp_hdr) + sizeof(struct dccp_hdr_ext));
-
- /*
- * Leave enough headroom for common DCCP header options.
- * This only considers options which may appear on DCCP-Data packets, as
- * per table 3 in RFC 4340, 5.8. When running out of space for other
- * options (eg. Ack Vector which can take up to 255 bytes), it is better
- * to schedule a separate Ack. Thus we leave headroom for the following:
- * - 1 byte for Slow Receiver (11.6)
- * - 6 bytes for Timestamp (13.1)
- * - 10 bytes for Timestamp Echo (13.3)
- * - 8 bytes for NDP count (7.7, when activated)
- * - 6 bytes for Data Checksum (9.3)
- * - %DCCPAV_MIN_OPTLEN bytes for Ack Vector size (11.4, when enabled)
- */
- cur_mps -= roundup(1 + 6 + 10 + dp->dccps_send_ndp_count * 8 + 6 +
- (dp->dccps_hc_rx_ackvec ? DCCPAV_MIN_OPTLEN : 0), 4);
-
- /* And store cached results */
- icsk->icsk_pmtu_cookie = pmtu;
- WRITE_ONCE(dp->dccps_mss_cache, cur_mps);
-
- return cur_mps;
-}
-
-EXPORT_SYMBOL_GPL(dccp_sync_mss);
-
-void dccp_write_space(struct sock *sk)
-{
- struct socket_wq *wq;
-
- rcu_read_lock();
- wq = rcu_dereference(sk->sk_wq);
- if (skwq_has_sleeper(wq))
- wake_up_interruptible(&wq->wait);
- /* Should agree with poll, otherwise some programs break */
- if (sock_writeable(sk))
- sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
-
- rcu_read_unlock();
-}
-
-/**
- * dccp_wait_for_ccid - Await CCID send permission
- * @sk: socket to wait for
- * @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, unsigned long delay)
-{
- DEFINE_WAIT(wait);
- 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
- * @sk: socket to send data packet on
- *
- * 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);
-}
-
-/**
- * dccp_flush_write_queue - Drain queue at end of connection
- * @sk: socket to be drained
- * @time_budget: time allowed to drain the queue
- *
- * 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);
-
- 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)
-{
- struct dccp_sock *dp = dccp_sk(sk);
- struct sk_buff *skb;
-
- while ((skb = dccp_qpolicy_top(sk))) {
- int rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb);
-
- 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:
- dccp_qpolicy_drop(sk, skb);
- dccp_pr_debug("packet discarded due to err=%d\n", rc);
- }
- }
-}
-
-/**
- * dccp_retransmit_skb - Retransmit Request, Close, or CloseReq packets
- * @sk: socket to perform retransmit on
- *
- * There are only four retransmittable packet types in DCCP:
- * - Request in client-REQUEST state (sec. 8.1.1),
- * - CloseReq in server-CLOSEREQ state (sec. 8.3),
- * - Close in node-CLOSING state (sec. 8.3),
- * - Acks in client-PARTOPEN state (sec. 8.1.5, handled by dccp_delack_timer()).
- * This function expects sk->sk_send_head to contain the original skb.
- */
-int dccp_retransmit_skb(struct sock *sk)
-{
- WARN_ON(sk->sk_send_head == NULL);
-
- if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk) != 0)
- return -EHOSTUNREACH; /* Routing failure or similar. */
-
- /* this count is used to distinguish original and retransmitted skb */
- inet_csk(sk)->icsk_retransmits++;
-
- return dccp_transmit_skb(sk, skb_clone(sk->sk_send_head, GFP_ATOMIC));
-}
-
-struct sk_buff *dccp_make_response(const struct sock *sk, struct dst_entry *dst,
- struct request_sock *req)
-{
- struct dccp_hdr *dh;
- struct dccp_request_sock *dreq;
- const u32 dccp_header_size = sizeof(struct dccp_hdr) +
- sizeof(struct dccp_hdr_ext) +
- sizeof(struct dccp_hdr_response);
- struct sk_buff *skb;
-
- /* sk is marked const to clearly express we dont hold socket lock.
- * sock_wmalloc() will atomically change sk->sk_wmem_alloc,
- * it is safe to promote sk to non const.
- */
- skb = sock_wmalloc((struct sock *)sk, MAX_DCCP_HEADER, 1,
- GFP_ATOMIC);
- if (!skb)
- return NULL;
-
- skb_reserve(skb, MAX_DCCP_HEADER);
-
- skb_dst_set(skb, dst_clone(dst));
-
- dreq = dccp_rsk(req);
- if (inet_rsk(req)->acked) /* increase GSS upon retransmission */
- dccp_inc_seqno(&dreq->dreq_gss);
- DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE;
- DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_gss;
-
- /* Resolve feature dependencies resulting from choice of CCID */
- if (dccp_feat_server_ccid_dependencies(dreq))
- goto response_failed;
-
- if (dccp_insert_options_rsk(dreq, skb))
- goto response_failed;
-
- /* Build and checksum header */
- dh = dccp_zeroed_hdr(skb, dccp_header_size);
-
- dh->dccph_sport = htons(inet_rsk(req)->ir_num);
- dh->dccph_dport = inet_rsk(req)->ir_rmt_port;
- dh->dccph_doff = (dccp_header_size +
- DCCP_SKB_CB(skb)->dccpd_opt_len) / 4;
- dh->dccph_type = DCCP_PKT_RESPONSE;
- dh->dccph_x = 1;
- dccp_hdr_set_seq(dh, dreq->dreq_gss);
- dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_gsr);
- dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service;
-
- dccp_csum_outgoing(skb);
-
- /* We use `acked' to remember that a Response was already sent. */
- inet_rsk(req)->acked = 1;
- DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
- return skb;
-response_failed:
- kfree_skb(skb);
- return NULL;
-}
-
-EXPORT_SYMBOL_GPL(dccp_make_response);
-
-/* answer offending packet in @rcv_skb with Reset from control socket @ctl */
-struct sk_buff *dccp_ctl_make_reset(struct sock *sk, struct sk_buff *rcv_skb)
-{
- struct dccp_hdr *rxdh = dccp_hdr(rcv_skb), *dh;
- struct dccp_skb_cb *dcb = DCCP_SKB_CB(rcv_skb);
- const u32 dccp_hdr_reset_len = sizeof(struct dccp_hdr) +
- sizeof(struct dccp_hdr_ext) +
- sizeof(struct dccp_hdr_reset);
- struct dccp_hdr_reset *dhr;
- struct sk_buff *skb;
-
- skb = alloc_skb(sk->sk_prot->max_header, GFP_ATOMIC);
- if (skb == NULL)
- return NULL;
-
- skb_reserve(skb, sk->sk_prot->max_header);
-
- /* Swap the send and the receive. */
- dh = dccp_zeroed_hdr(skb, dccp_hdr_reset_len);
- dh->dccph_type = DCCP_PKT_RESET;
- dh->dccph_sport = rxdh->dccph_dport;
- dh->dccph_dport = rxdh->dccph_sport;
- dh->dccph_doff = dccp_hdr_reset_len / 4;
- dh->dccph_x = 1;
-
- dhr = dccp_hdr_reset(skb);
- dhr->dccph_reset_code = dcb->dccpd_reset_code;
-
- switch (dcb->dccpd_reset_code) {
- case DCCP_RESET_CODE_PACKET_ERROR:
- dhr->dccph_reset_data[0] = rxdh->dccph_type;
- break;
- case DCCP_RESET_CODE_OPTION_ERROR:
- case DCCP_RESET_CODE_MANDATORY_ERROR:
- memcpy(dhr->dccph_reset_data, dcb->dccpd_reset_data, 3);
- break;
- }
- /*
- * From RFC 4340, 8.3.1:
- * If P.ackno exists, set R.seqno := P.ackno + 1.
- * Else set R.seqno := 0.
- */
- if (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
- dccp_hdr_set_seq(dh, ADD48(dcb->dccpd_ack_seq, 1));
- dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dcb->dccpd_seq);
-
- dccp_csum_outgoing(skb);
- return skb;
-}
-
-EXPORT_SYMBOL_GPL(dccp_ctl_make_reset);
-
-/* send Reset on established socket, to close or abort the connection */
-int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code)
-{
- struct sk_buff *skb;
- /*
- * FIXME: what if rebuild_header fails?
- * Should we be doing a rebuild_header here?
- */
- int err = inet_csk(sk)->icsk_af_ops->rebuild_header(sk);
-
- if (err != 0)
- return err;
-
- skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, GFP_ATOMIC);
- if (skb == NULL)
- return -ENOBUFS;
-
- /* Reserve space for headers and prepare control bits. */
- skb_reserve(skb, sk->sk_prot->max_header);
- DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESET;
- DCCP_SKB_CB(skb)->dccpd_reset_code = code;
-
- return dccp_transmit_skb(sk, skb);
-}
-
-/*
- * Do all connect socket setups that can be done AF independent.
- */
-int dccp_connect(struct sock *sk)
-{
- struct sk_buff *skb;
- struct dccp_sock *dp = dccp_sk(sk);
- struct dst_entry *dst = __sk_dst_get(sk);
- struct inet_connection_sock *icsk = inet_csk(sk);
-
- sk->sk_err = 0;
- sock_reset_flag(sk, SOCK_DONE);
-
- dccp_sync_mss(sk, dst_mtu(dst));
-
- /* do not connect if feature negotiation setup fails */
- if (dccp_feat_finalise_settings(dccp_sk(sk)))
- return -EPROTO;
-
- /* Initialise GAR as per 8.5; AWL/AWH are set in dccp_transmit_skb() */
- dp->dccps_gar = dp->dccps_iss;
-
- skb = alloc_skb(sk->sk_prot->max_header, sk->sk_allocation);
- if (unlikely(skb == NULL))
- return -ENOBUFS;
-
- /* Reserve space for headers. */
- skb_reserve(skb, sk->sk_prot->max_header);
-
- DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_REQUEST;
-
- dccp_transmit_skb(sk, dccp_skb_entail(sk, skb));
- DCCP_INC_STATS(DCCP_MIB_ACTIVEOPENS);
-
- /* Timer for repeating the REQUEST until an answer. */
- icsk->icsk_retransmits = 0;
- inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
- icsk->icsk_rto, DCCP_RTO_MAX);
- return 0;
-}
-
-EXPORT_SYMBOL_GPL(dccp_connect);
-
-void dccp_send_ack(struct sock *sk)
-{
- /* If we have been reset, we may not send again. */
- if (sk->sk_state != DCCP_CLOSED) {
- struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header,
- GFP_ATOMIC);
-
- if (skb == NULL) {
- inet_csk_schedule_ack(sk);
- inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN;
- inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
- TCP_DELACK_MAX,
- DCCP_RTO_MAX);
- return;
- }
-
- /* Reserve space for headers */
- skb_reserve(skb, sk->sk_prot->max_header);
- DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_ACK;
- dccp_transmit_skb(sk, skb);
- }
-}
-
-EXPORT_SYMBOL_GPL(dccp_send_ack);
-
-#if 0
-/* 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_delack_timeout(icsk)))
- timeout = icsk_delack_timeout(icsk);
- }
- icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER;
- sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout);
-}
-#endif
-
-void dccp_send_sync(struct sock *sk, const u64 ackno,
- const enum dccp_pkt_type pkt_type)
-{
- /*
- * We are not putting this on the write queue, so
- * dccp_transmit_skb() will set the ownership to this
- * sock.
- */
- struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, GFP_ATOMIC);
-
- if (skb == NULL) {
- /* FIXME: how to make sure the sync is sent? */
- DCCP_CRIT("could not send %s", dccp_packet_name(pkt_type));
- return;
- }
-
- /* Reserve space for headers and prepare control bits. */
- skb_reserve(skb, sk->sk_prot->max_header);
- DCCP_SKB_CB(skb)->dccpd_type = pkt_type;
- DCCP_SKB_CB(skb)->dccpd_ack_seq = ackno;
-
- /*
- * Clear the flag in case the Sync was scheduled for out-of-band data,
- * such as carrying a long Ack Vector.
- */
- dccp_sk(sk)->dccps_sync_scheduled = 0;
-
- dccp_transmit_skb(sk, skb);
-}
-
-EXPORT_SYMBOL_GPL(dccp_send_sync);
-
-/*
- * Send a DCCP_PKT_CLOSE/CLOSEREQ. The caller locks the socket for us. This
- * cannot be allowed to fail queueing a DCCP_PKT_CLOSE/CLOSEREQ frame under
- * any circumstances.
- */
-void dccp_send_close(struct sock *sk, const int active)
-{
- struct dccp_sock *dp = dccp_sk(sk);
- struct sk_buff *skb;
- const gfp_t prio = active ? GFP_KERNEL : GFP_ATOMIC;
-
- skb = alloc_skb(sk->sk_prot->max_header, prio);
- if (skb == NULL)
- return;
-
- /* Reserve space for headers and prepare control bits. */
- skb_reserve(skb, sk->sk_prot->max_header);
- if (dp->dccps_role == DCCP_ROLE_SERVER && !dp->dccps_server_timewait)
- DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_CLOSEREQ;
- else
- DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_CLOSE;
-
- if (active) {
- skb = dccp_skb_entail(sk, skb);
- /*
- * Retransmission timer for active-close: RFC 4340, 8.3 requires
- * to retransmit the Close/CloseReq until the CLOSING/CLOSEREQ
- * state can be left. The initial timeout is 2 RTTs.
- * Since RTT measurement is done by the CCIDs, there is no easy
- * way to get an RTT sample. The fallback RTT from RFC 4340, 3.4
- * is too low (200ms); we use a high value to avoid unnecessary
- * retransmissions when the link RTT is > 0.2 seconds.
- * FIXME: Let main module sample RTTs and use that instead.
- */
- inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
- DCCP_TIMEOUT_INIT, DCCP_RTO_MAX);
- }
- dccp_transmit_skb(sk, skb);
-}
generated by cgit (git 2.34.1) at 2025-05-30 08:50:55 +0000