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-rw-r--r--net/rxrpc/ar-ack.c1250
1 files changed, 1250 insertions, 0 deletions
diff --git a/net/rxrpc/ar-ack.c b/net/rxrpc/ar-ack.c
new file mode 100644
index 000000000000..8f7764eca96c
--- /dev/null
+++ b/net/rxrpc/ar-ack.c
@@ -0,0 +1,1250 @@
+/* Management of Tx window, Tx resend, ACKs and out-of-sequence reception
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/circ_buf.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/udp.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+static unsigned rxrpc_ack_defer = 1;
+
+static const char *rxrpc_acks[] = {
+ "---", "REQ", "DUP", "OOS", "WIN", "MEM", "PNG", "PNR", "DLY", "IDL",
+ "-?-"
+};
+
+static const s8 rxrpc_ack_priority[] = {
+ [0] = 0,
+ [RXRPC_ACK_DELAY] = 1,
+ [RXRPC_ACK_REQUESTED] = 2,
+ [RXRPC_ACK_IDLE] = 3,
+ [RXRPC_ACK_PING_RESPONSE] = 4,
+ [RXRPC_ACK_DUPLICATE] = 5,
+ [RXRPC_ACK_OUT_OF_SEQUENCE] = 6,
+ [RXRPC_ACK_EXCEEDS_WINDOW] = 7,
+ [RXRPC_ACK_NOSPACE] = 8,
+};
+
+/*
+ * propose an ACK be sent
+ */
+void __rxrpc_propose_ACK(struct rxrpc_call *call, uint8_t ack_reason,
+ __be32 serial, bool immediate)
+{
+ unsigned long expiry;
+ s8 prior = rxrpc_ack_priority[ack_reason];
+
+ ASSERTCMP(prior, >, 0);
+
+ _enter("{%d},%s,%%%x,%u",
+ call->debug_id, rxrpc_acks[ack_reason], ntohl(serial),
+ immediate);
+
+ if (prior < rxrpc_ack_priority[call->ackr_reason]) {
+ if (immediate)
+ goto cancel_timer;
+ return;
+ }
+
+ /* update DELAY, IDLE, REQUESTED and PING_RESPONSE ACK serial
+ * numbers */
+ if (prior == rxrpc_ack_priority[call->ackr_reason]) {
+ if (prior <= 4)
+ call->ackr_serial = serial;
+ if (immediate)
+ goto cancel_timer;
+ return;
+ }
+
+ call->ackr_reason = ack_reason;
+ call->ackr_serial = serial;
+
+ switch (ack_reason) {
+ case RXRPC_ACK_DELAY:
+ _debug("run delay timer");
+ call->ack_timer.expires = jiffies + rxrpc_ack_timeout * HZ;
+ add_timer(&call->ack_timer);
+ return;
+
+ case RXRPC_ACK_IDLE:
+ if (!immediate) {
+ _debug("run defer timer");
+ expiry = 1;
+ goto run_timer;
+ }
+ goto cancel_timer;
+
+ case RXRPC_ACK_REQUESTED:
+ if (!rxrpc_ack_defer)
+ goto cancel_timer;
+ if (!immediate || serial == cpu_to_be32(1)) {
+ _debug("run defer timer");
+ expiry = rxrpc_ack_defer;
+ goto run_timer;
+ }
+
+ default:
+ _debug("immediate ACK");
+ goto cancel_timer;
+ }
+
+run_timer:
+ expiry += jiffies;
+ if (!timer_pending(&call->ack_timer) ||
+ time_after(call->ack_timer.expires, expiry))
+ mod_timer(&call->ack_timer, expiry);
+ return;
+
+cancel_timer:
+ _debug("cancel timer %%%u", ntohl(serial));
+ try_to_del_timer_sync(&call->ack_timer);
+ read_lock_bh(&call->state_lock);
+ if (call->state <= RXRPC_CALL_COMPLETE &&
+ !test_and_set_bit(RXRPC_CALL_ACK, &call->events))
+ schedule_work(&call->processor);
+ read_unlock_bh(&call->state_lock);
+}
+
+/*
+ * propose an ACK be sent, locking the call structure
+ */
+void rxrpc_propose_ACK(struct rxrpc_call *call, uint8_t ack_reason,
+ __be32 serial, bool immediate)
+{
+ s8 prior = rxrpc_ack_priority[ack_reason];
+
+ if (prior > rxrpc_ack_priority[call->ackr_reason]) {
+ spin_lock_bh(&call->lock);
+ __rxrpc_propose_ACK(call, ack_reason, serial, immediate);
+ spin_unlock_bh(&call->lock);
+ }
+}
+
+/*
+ * set the resend timer
+ */
+static void rxrpc_set_resend(struct rxrpc_call *call, u8 resend,
+ unsigned long resend_at)
+{
+ read_lock_bh(&call->state_lock);
+ if (call->state >= RXRPC_CALL_COMPLETE)
+ resend = 0;
+
+ if (resend & 1) {
+ _debug("SET RESEND");
+ set_bit(RXRPC_CALL_RESEND, &call->events);
+ }
+
+ if (resend & 2) {
+ _debug("MODIFY RESEND TIMER");
+ set_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
+ mod_timer(&call->resend_timer, resend_at);
+ } else {
+ _debug("KILL RESEND TIMER");
+ del_timer_sync(&call->resend_timer);
+ clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events);
+ clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
+ }
+ read_unlock_bh(&call->state_lock);
+}
+
+/*
+ * resend packets
+ */
+static void rxrpc_resend(struct rxrpc_call *call)
+{
+ struct rxrpc_skb_priv *sp;
+ struct rxrpc_header *hdr;
+ struct sk_buff *txb;
+ unsigned long *p_txb, resend_at;
+ int loop, stop;
+ u8 resend;
+
+ _enter("{%d,%d,%d,%d},",
+ call->acks_hard, call->acks_unacked,
+ atomic_read(&call->sequence),
+ CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz));
+
+ stop = 0;
+ resend = 0;
+ resend_at = 0;
+
+ for (loop = call->acks_tail;
+ loop != call->acks_head || stop;
+ loop = (loop + 1) & (call->acks_winsz - 1)
+ ) {
+ p_txb = call->acks_window + loop;
+ smp_read_barrier_depends();
+ if (*p_txb & 1)
+ continue;
+
+ txb = (struct sk_buff *) *p_txb;
+ sp = rxrpc_skb(txb);
+
+ if (sp->need_resend) {
+ sp->need_resend = 0;
+
+ /* each Tx packet has a new serial number */
+ sp->hdr.serial =
+ htonl(atomic_inc_return(&call->conn->serial));
+
+ hdr = (struct rxrpc_header *) txb->head;
+ hdr->serial = sp->hdr.serial;
+
+ _proto("Tx DATA %%%u { #%d }",
+ ntohl(sp->hdr.serial), ntohl(sp->hdr.seq));
+ if (rxrpc_send_packet(call->conn->trans, txb) < 0) {
+ stop = 0;
+ sp->resend_at = jiffies + 3;
+ } else {
+ sp->resend_at =
+ jiffies + rxrpc_resend_timeout * HZ;
+ }
+ }
+
+ if (time_after_eq(jiffies + 1, sp->resend_at)) {
+ sp->need_resend = 1;
+ resend |= 1;
+ } else if (resend & 2) {
+ if (time_before(sp->resend_at, resend_at))
+ resend_at = sp->resend_at;
+ } else {
+ resend_at = sp->resend_at;
+ resend |= 2;
+ }
+ }
+
+ rxrpc_set_resend(call, resend, resend_at);
+ _leave("");
+}
+
+/*
+ * handle resend timer expiry
+ */
+static void rxrpc_resend_timer(struct rxrpc_call *call)
+{
+ struct rxrpc_skb_priv *sp;
+ struct sk_buff *txb;
+ unsigned long *p_txb, resend_at;
+ int loop;
+ u8 resend;
+
+ _enter("%d,%d,%d",
+ call->acks_tail, call->acks_unacked, call->acks_head);
+
+ resend = 0;
+ resend_at = 0;
+
+ for (loop = call->acks_unacked;
+ loop != call->acks_head;
+ loop = (loop + 1) & (call->acks_winsz - 1)
+ ) {
+ p_txb = call->acks_window + loop;
+ smp_read_barrier_depends();
+ txb = (struct sk_buff *) (*p_txb & ~1);
+ sp = rxrpc_skb(txb);
+
+ ASSERT(!(*p_txb & 1));
+
+ if (sp->need_resend) {
+ ;
+ } else if (time_after_eq(jiffies + 1, sp->resend_at)) {
+ sp->need_resend = 1;
+ resend |= 1;
+ } else if (resend & 2) {
+ if (time_before(sp->resend_at, resend_at))
+ resend_at = sp->resend_at;
+ } else {
+ resend_at = sp->resend_at;
+ resend |= 2;
+ }
+ }
+
+ rxrpc_set_resend(call, resend, resend_at);
+ _leave("");
+}
+
+/*
+ * process soft ACKs of our transmitted packets
+ * - these indicate packets the peer has or has not received, but hasn't yet
+ * given to the consumer, and so can still be discarded and re-requested
+ */
+static int rxrpc_process_soft_ACKs(struct rxrpc_call *call,
+ struct rxrpc_ackpacket *ack,
+ struct sk_buff *skb)
+{
+ struct rxrpc_skb_priv *sp;
+ struct sk_buff *txb;
+ unsigned long *p_txb, resend_at;
+ int loop;
+ u8 sacks[RXRPC_MAXACKS], resend;
+
+ _enter("{%d,%d},{%d},",
+ call->acks_hard,
+ CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz),
+ ack->nAcks);
+
+ if (skb_copy_bits(skb, 0, sacks, ack->nAcks) < 0)
+ goto protocol_error;
+
+ resend = 0;
+ resend_at = 0;
+ for (loop = 0; loop < ack->nAcks; loop++) {
+ p_txb = call->acks_window;
+ p_txb += (call->acks_tail + loop) & (call->acks_winsz - 1);
+ smp_read_barrier_depends();
+ txb = (struct sk_buff *) (*p_txb & ~1);
+ sp = rxrpc_skb(txb);
+
+ switch (sacks[loop]) {
+ case RXRPC_ACK_TYPE_ACK:
+ sp->need_resend = 0;
+ *p_txb |= 1;
+ break;
+ case RXRPC_ACK_TYPE_NACK:
+ sp->need_resend = 1;
+ *p_txb &= ~1;
+ resend = 1;
+ break;
+ default:
+ _debug("Unsupported ACK type %d", sacks[loop]);
+ goto protocol_error;
+ }
+ }
+
+ smp_mb();
+ call->acks_unacked = (call->acks_tail + loop) & (call->acks_winsz - 1);
+
+ /* anything not explicitly ACK'd is implicitly NACK'd, but may just not
+ * have been received or processed yet by the far end */
+ for (loop = call->acks_unacked;
+ loop != call->acks_head;
+ loop = (loop + 1) & (call->acks_winsz - 1)
+ ) {
+ p_txb = call->acks_window + loop;
+ smp_read_barrier_depends();
+ txb = (struct sk_buff *) (*p_txb & ~1);
+ sp = rxrpc_skb(txb);
+
+ if (*p_txb & 1) {
+ /* packet must have been discarded */
+ sp->need_resend = 1;
+ *p_txb &= ~1;
+ resend |= 1;
+ } else if (sp->need_resend) {
+ ;
+ } else if (time_after_eq(jiffies + 1, sp->resend_at)) {
+ sp->need_resend = 1;
+ resend |= 1;
+ } else if (resend & 2) {
+ if (time_before(sp->resend_at, resend_at))
+ resend_at = sp->resend_at;
+ } else {
+ resend_at = sp->resend_at;
+ resend |= 2;
+ }
+ }
+
+ rxrpc_set_resend(call, resend, resend_at);
+ _leave(" = 0");
+ return 0;
+
+protocol_error:
+ _leave(" = -EPROTO");
+ return -EPROTO;
+}
+
+/*
+ * discard hard-ACK'd packets from the Tx window
+ */
+static void rxrpc_rotate_tx_window(struct rxrpc_call *call, u32 hard)
+{
+ struct rxrpc_skb_priv *sp;
+ unsigned long _skb;
+ int tail = call->acks_tail, old_tail;
+ int win = CIRC_CNT(call->acks_head, tail, call->acks_winsz);
+
+ _enter("{%u,%u},%u", call->acks_hard, win, hard);
+
+ ASSERTCMP(hard - call->acks_hard, <=, win);
+
+ while (call->acks_hard < hard) {
+ smp_read_barrier_depends();
+ _skb = call->acks_window[tail] & ~1;
+ sp = rxrpc_skb((struct sk_buff *) _skb);
+ rxrpc_free_skb((struct sk_buff *) _skb);
+ old_tail = tail;
+ tail = (tail + 1) & (call->acks_winsz - 1);
+ call->acks_tail = tail;
+ if (call->acks_unacked == old_tail)
+ call->acks_unacked = tail;
+ call->acks_hard++;
+ }
+
+ wake_up(&call->tx_waitq);
+}
+
+/*
+ * clear the Tx window in the event of a failure
+ */
+static void rxrpc_clear_tx_window(struct rxrpc_call *call)
+{
+ rxrpc_rotate_tx_window(call, atomic_read(&call->sequence));
+}
+
+/*
+ * drain the out of sequence received packet queue into the packet Rx queue
+ */
+static int rxrpc_drain_rx_oos_queue(struct rxrpc_call *call)
+{
+ struct rxrpc_skb_priv *sp;
+ struct sk_buff *skb;
+ bool terminal;
+ int ret;
+
+ _enter("{%d,%d}", call->rx_data_post, call->rx_first_oos);
+
+ spin_lock_bh(&call->lock);
+
+ ret = -ECONNRESET;
+ if (test_bit(RXRPC_CALL_RELEASED, &call->flags))
+ goto socket_unavailable;
+
+ skb = skb_dequeue(&call->rx_oos_queue);
+ if (skb) {
+ sp = rxrpc_skb(skb);
+
+ _debug("drain OOS packet %d [%d]",
+ ntohl(sp->hdr.seq), call->rx_first_oos);
+
+ if (ntohl(sp->hdr.seq) != call->rx_first_oos) {
+ skb_queue_head(&call->rx_oos_queue, skb);
+ call->rx_first_oos = ntohl(rxrpc_skb(skb)->hdr.seq);
+ _debug("requeue %p {%u}", skb, call->rx_first_oos);
+ } else {
+ skb->mark = RXRPC_SKB_MARK_DATA;
+ terminal = ((sp->hdr.flags & RXRPC_LAST_PACKET) &&
+ !(sp->hdr.flags & RXRPC_CLIENT_INITIATED));
+ ret = rxrpc_queue_rcv_skb(call, skb, true, terminal);
+ BUG_ON(ret < 0);
+ _debug("drain #%u", call->rx_data_post);
+ call->rx_data_post++;
+
+ /* find out what the next packet is */
+ skb = skb_peek(&call->rx_oos_queue);
+ if (skb)
+ call->rx_first_oos =
+ ntohl(rxrpc_skb(skb)->hdr.seq);
+ else
+ call->rx_first_oos = 0;
+ _debug("peek %p {%u}", skb, call->rx_first_oos);
+ }
+ }
+
+ ret = 0;
+socket_unavailable:
+ spin_unlock_bh(&call->lock);
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * insert an out of sequence packet into the buffer
+ */
+static void rxrpc_insert_oos_packet(struct rxrpc_call *call,
+ struct sk_buff *skb)
+{
+ struct rxrpc_skb_priv *sp, *psp;
+ struct sk_buff *p;
+ u32 seq;
+
+ sp = rxrpc_skb(skb);
+ seq = ntohl(sp->hdr.seq);
+ _enter(",,{%u}", seq);
+
+ skb->destructor = rxrpc_packet_destructor;
+ ASSERTCMP(sp->call, ==, NULL);
+ sp->call = call;
+ rxrpc_get_call(call);
+
+ /* insert into the buffer in sequence order */
+ spin_lock_bh(&call->lock);
+
+ skb_queue_walk(&call->rx_oos_queue, p) {
+ psp = rxrpc_skb(p);
+ if (ntohl(psp->hdr.seq) > seq) {
+ _debug("insert oos #%u before #%u",
+ seq, ntohl(psp->hdr.seq));
+ skb_insert(p, skb, &call->rx_oos_queue);
+ goto inserted;
+ }
+ }
+
+ _debug("append oos #%u", seq);
+ skb_queue_tail(&call->rx_oos_queue, skb);
+inserted:
+
+ /* we might now have a new front to the queue */
+ if (call->rx_first_oos == 0 || seq < call->rx_first_oos)
+ call->rx_first_oos = seq;
+
+ read_lock(&call->state_lock);
+ if (call->state < RXRPC_CALL_COMPLETE &&
+ call->rx_data_post == call->rx_first_oos) {
+ _debug("drain rx oos now");
+ set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events);
+ }
+ read_unlock(&call->state_lock);
+
+ spin_unlock_bh(&call->lock);
+ _leave(" [stored #%u]", call->rx_first_oos);
+}
+
+/*
+ * clear the Tx window on final ACK reception
+ */
+static void rxrpc_zap_tx_window(struct rxrpc_call *call)
+{
+ struct rxrpc_skb_priv *sp;
+ struct sk_buff *skb;
+ unsigned long _skb, *acks_window;
+ uint8_t winsz = call->acks_winsz;
+ int tail;
+
+ acks_window = call->acks_window;
+ call->acks_window = NULL;
+
+ while (CIRC_CNT(call->acks_head, call->acks_tail, winsz) > 0) {
+ tail = call->acks_tail;
+ smp_read_barrier_depends();
+ _skb = acks_window[tail] & ~1;
+ smp_mb();
+ call->acks_tail = (call->acks_tail + 1) & (winsz - 1);
+
+ skb = (struct sk_buff *) _skb;
+ sp = rxrpc_skb(skb);
+ _debug("+++ clear Tx %u", ntohl(sp->hdr.seq));
+ rxrpc_free_skb(skb);
+ }
+
+ kfree(acks_window);
+}
+
+/*
+ * process packets in the reception queue
+ */
+static int rxrpc_process_rx_queue(struct rxrpc_call *call,
+ u32 *_abort_code)
+{
+ struct rxrpc_ackpacket ack;
+ struct rxrpc_skb_priv *sp;
+ struct sk_buff *skb;
+ bool post_ACK;
+ int latest;
+ u32 hard, tx;
+
+ _enter("");
+
+process_further:
+ skb = skb_dequeue(&call->rx_queue);
+ if (!skb)
+ return -EAGAIN;
+
+ _net("deferred skb %p", skb);
+
+ sp = rxrpc_skb(skb);
+
+ _debug("process %s [st %d]", rxrpc_pkts[sp->hdr.type], call->state);
+
+ post_ACK = false;
+
+ switch (sp->hdr.type) {
+ /* data packets that wind up here have been received out of
+ * order, need security processing or are jumbo packets */
+ case RXRPC_PACKET_TYPE_DATA:
+ _proto("OOSQ DATA %%%u { #%u }",
+ ntohl(sp->hdr.serial), ntohl(sp->hdr.seq));
+
+ /* secured packets must be verified and possibly decrypted */
+ if (rxrpc_verify_packet(call, skb, _abort_code) < 0)
+ goto protocol_error;
+
+ rxrpc_insert_oos_packet(call, skb);
+ goto process_further;
+
+ /* partial ACK to process */
+ case RXRPC_PACKET_TYPE_ACK:
+ if (skb_copy_bits(skb, 0, &ack, sizeof(ack)) < 0) {
+ _debug("extraction failure");
+ goto protocol_error;
+ }
+ if (!skb_pull(skb, sizeof(ack)))
+ BUG();
+
+ latest = ntohl(sp->hdr.serial);
+ hard = ntohl(ack.firstPacket);
+ tx = atomic_read(&call->sequence);
+
+ _proto("Rx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }",
+ latest,
+ ntohs(ack.maxSkew),
+ hard,
+ ntohl(ack.previousPacket),
+ ntohl(ack.serial),
+ rxrpc_acks[ack.reason],
+ ack.nAcks);
+
+ if (ack.reason == RXRPC_ACK_PING) {
+ _proto("Rx ACK %%%u PING Request", latest);
+ rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE,
+ sp->hdr.serial, true);
+ }
+
+ /* discard any out-of-order or duplicate ACKs */
+ if (latest - call->acks_latest <= 0) {
+ _debug("discard ACK %d <= %d",
+ latest, call->acks_latest);
+ goto discard;
+ }
+ call->acks_latest = latest;
+
+ if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
+ call->state != RXRPC_CALL_CLIENT_AWAIT_REPLY &&
+ call->state != RXRPC_CALL_SERVER_SEND_REPLY &&
+ call->state != RXRPC_CALL_SERVER_AWAIT_ACK)
+ goto discard;
+
+ _debug("Tx=%d H=%u S=%d", tx, call->acks_hard, call->state);
+
+ if (hard > 0) {
+ if (hard - 1 > tx) {
+ _debug("hard-ACK'd packet %d not transmitted"
+ " (%d top)",
+ hard - 1, tx);
+ goto protocol_error;
+ }
+
+ if ((call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY ||
+ call->state == RXRPC_CALL_SERVER_AWAIT_ACK) &&
+ hard > tx)
+ goto all_acked;
+
+ smp_rmb();
+ rxrpc_rotate_tx_window(call, hard - 1);
+ }
+
+ if (ack.nAcks > 0) {
+ if (hard - 1 + ack.nAcks > tx) {
+ _debug("soft-ACK'd packet %d+%d not"
+ " transmitted (%d top)",
+ hard - 1, ack.nAcks, tx);
+ goto protocol_error;
+ }
+
+ if (rxrpc_process_soft_ACKs(call, &ack, skb) < 0)
+ goto protocol_error;
+ }
+ goto discard;
+
+ /* complete ACK to process */
+ case RXRPC_PACKET_TYPE_ACKALL:
+ goto all_acked;
+
+ /* abort and busy are handled elsewhere */
+ case RXRPC_PACKET_TYPE_BUSY:
+ case RXRPC_PACKET_TYPE_ABORT:
+ BUG();
+
+ /* connection level events - also handled elsewhere */
+ case RXRPC_PACKET_TYPE_CHALLENGE:
+ case RXRPC_PACKET_TYPE_RESPONSE:
+ case RXRPC_PACKET_TYPE_DEBUG:
+ BUG();
+ }
+
+ /* if we've had a hard ACK that covers all the packets we've sent, then
+ * that ends that phase of the operation */
+all_acked:
+ write_lock_bh(&call->state_lock);
+ _debug("ack all %d", call->state);
+
+ switch (call->state) {
+ case RXRPC_CALL_CLIENT_AWAIT_REPLY:
+ call->state = RXRPC_CALL_CLIENT_RECV_REPLY;
+ break;
+ case RXRPC_CALL_SERVER_AWAIT_ACK:
+ _debug("srv complete");
+ call->state = RXRPC_CALL_COMPLETE;
+ post_ACK = true;
+ break;
+ case RXRPC_CALL_CLIENT_SEND_REQUEST:
+ case RXRPC_CALL_SERVER_RECV_REQUEST:
+ goto protocol_error_unlock; /* can't occur yet */
+ default:
+ write_unlock_bh(&call->state_lock);
+ goto discard; /* assume packet left over from earlier phase */
+ }
+
+ write_unlock_bh(&call->state_lock);
+
+ /* if all the packets we sent are hard-ACK'd, then we can discard
+ * whatever we've got left */
+ _debug("clear Tx %d",
+ CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz));
+
+ del_timer_sync(&call->resend_timer);
+ clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
+ clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events);
+
+ if (call->acks_window)
+ rxrpc_zap_tx_window(call);
+
+ if (post_ACK) {
+ /* post the final ACK message for userspace to pick up */
+ _debug("post ACK");
+ skb->mark = RXRPC_SKB_MARK_FINAL_ACK;
+ sp->call = call;
+ rxrpc_get_call(call);
+ spin_lock_bh(&call->lock);
+ if (rxrpc_queue_rcv_skb(call, skb, true, true) < 0)
+ BUG();
+ spin_unlock_bh(&call->lock);
+ goto process_further;
+ }
+
+discard:
+ rxrpc_free_skb(skb);
+ goto process_further;
+
+protocol_error_unlock:
+ write_unlock_bh(&call->state_lock);
+protocol_error:
+ rxrpc_free_skb(skb);
+ _leave(" = -EPROTO");
+ return -EPROTO;
+}
+
+/*
+ * post a message to the socket Rx queue for recvmsg() to pick up
+ */
+static int rxrpc_post_message(struct rxrpc_call *call, u32 mark, u32 error,
+ bool fatal)
+{
+ struct rxrpc_skb_priv *sp;
+ struct sk_buff *skb;
+ int ret;
+
+ _enter("{%d,%lx},%u,%u,%d",
+ call->debug_id, call->flags, mark, error, fatal);
+
+ /* remove timers and things for fatal messages */
+ if (fatal) {
+ del_timer_sync(&call->resend_timer);
+ del_timer_sync(&call->ack_timer);
+ clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
+ }
+
+ if (mark != RXRPC_SKB_MARK_NEW_CALL &&
+ !test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
+ _leave("[no userid]");
+ return 0;
+ }
+
+ if (!test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags)) {
+ skb = alloc_skb(0, GFP_NOFS);
+ if (!skb)
+ return -ENOMEM;
+
+ rxrpc_new_skb(skb);
+
+ skb->mark = mark;
+
+ sp = rxrpc_skb(skb);
+ memset(sp, 0, sizeof(*sp));
+ sp->error = error;
+ sp->call = call;
+ rxrpc_get_call(call);
+
+ spin_lock_bh(&call->lock);
+ ret = rxrpc_queue_rcv_skb(call, skb, true, fatal);
+ spin_unlock_bh(&call->lock);
+ if (ret < 0)
+ BUG();
+ }
+
+ return 0;
+}
+
+/*
+ * handle background processing of incoming call packets and ACK / abort
+ * generation
+ */
+void rxrpc_process_call(struct work_struct *work)
+{
+ struct rxrpc_call *call =
+ container_of(work, struct rxrpc_call, processor);
+ struct rxrpc_ackpacket ack;
+ struct rxrpc_ackinfo ackinfo;
+ struct rxrpc_header hdr;
+ struct msghdr msg;
+ struct kvec iov[5];
+ unsigned long bits;
+ __be32 data;
+ size_t len;
+ int genbit, loop, nbit, ioc, ret;
+ u32 abort_code = RX_PROTOCOL_ERROR;
+ u8 *acks = NULL;
+
+ //printk("\n--------------------\n");
+ _enter("{%d,%s,%lx} [%lu]",
+ call->debug_id, rxrpc_call_states[call->state], call->events,
+ (jiffies - call->creation_jif) / (HZ / 10));
+
+ if (test_and_set_bit(RXRPC_CALL_PROC_BUSY, &call->flags)) {
+ _debug("XXXXXXXXXXXXX RUNNING ON MULTIPLE CPUS XXXXXXXXXXXXX");
+ return;
+ }
+
+ /* there's a good chance we're going to have to send a message, so set
+ * one up in advance */
+ msg.msg_name = &call->conn->trans->peer->srx.transport.sin;
+ msg.msg_namelen = sizeof(call->conn->trans->peer->srx.transport.sin);
+ msg.msg_control = NULL;
+ msg.msg_controllen = 0;
+ msg.msg_flags = 0;
+
+ hdr.epoch = call->conn->epoch;
+ hdr.cid = call->cid;
+ hdr.callNumber = call->call_id;
+ hdr.seq = 0;
+ hdr.type = RXRPC_PACKET_TYPE_ACK;
+ hdr.flags = call->conn->out_clientflag;
+ hdr.userStatus = 0;
+ hdr.securityIndex = call->conn->security_ix;
+ hdr._rsvd = 0;
+ hdr.serviceId = call->conn->service_id;
+
+ memset(iov, 0, sizeof(iov));
+ iov[0].iov_base = &hdr;
+ iov[0].iov_len = sizeof(hdr);
+
+ /* deal with events of a final nature */
+ if (test_bit(RXRPC_CALL_RELEASE, &call->events)) {
+ rxrpc_release_call(call);
+ clear_bit(RXRPC_CALL_RELEASE, &call->events);
+ }
+
+ if (test_bit(RXRPC_CALL_RCVD_ERROR, &call->events)) {
+ int error;
+
+ clear_bit(RXRPC_CALL_CONN_ABORT, &call->events);
+ clear_bit(RXRPC_CALL_REJECT_BUSY, &call->events);
+ clear_bit(RXRPC_CALL_ABORT, &call->events);
+
+ error = call->conn->trans->peer->net_error;
+ _debug("post net error %d", error);
+
+ if (rxrpc_post_message(call, RXRPC_SKB_MARK_NET_ERROR,
+ error, true) < 0)
+ goto no_mem;
+ clear_bit(RXRPC_CALL_RCVD_ERROR, &call->events);
+ goto kill_ACKs;
+ }
+
+ if (test_bit(RXRPC_CALL_CONN_ABORT, &call->events)) {
+ ASSERTCMP(call->state, >, RXRPC_CALL_COMPLETE);
+
+ clear_bit(RXRPC_CALL_REJECT_BUSY, &call->events);
+ clear_bit(RXRPC_CALL_ABORT, &call->events);
+
+ _debug("post conn abort");
+
+ if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR,
+ call->conn->error, true) < 0)
+ goto no_mem;
+ clear_bit(RXRPC_CALL_CONN_ABORT, &call->events);
+ goto kill_ACKs;
+ }
+
+ if (test_bit(RXRPC_CALL_REJECT_BUSY, &call->events)) {
+ hdr.type = RXRPC_PACKET_TYPE_BUSY;
+ genbit = RXRPC_CALL_REJECT_BUSY;
+ goto send_message;
+ }
+
+ if (test_bit(RXRPC_CALL_ABORT, &call->events)) {
+ ASSERTCMP(call->state, >, RXRPC_CALL_COMPLETE);
+
+ if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR,
+ ECONNABORTED, true) < 0)
+ goto no_mem;
+ hdr.type = RXRPC_PACKET_TYPE_ABORT;
+ data = htonl(call->abort_code);
+ iov[1].iov_base = &data;
+ iov[1].iov_len = sizeof(data);
+ genbit = RXRPC_CALL_ABORT;
+ goto send_message;
+ }
+
+ if (test_bit(RXRPC_CALL_ACK_FINAL, &call->events)) {
+ hdr.type = RXRPC_PACKET_TYPE_ACKALL;
+ genbit = RXRPC_CALL_ACK_FINAL;
+ goto send_message;
+ }
+
+ if (call->events & ((1 << RXRPC_CALL_RCVD_BUSY) |
+ (1 << RXRPC_CALL_RCVD_ABORT))
+ ) {
+ u32 mark;
+
+ if (test_bit(RXRPC_CALL_RCVD_ABORT, &call->events))
+ mark = RXRPC_SKB_MARK_REMOTE_ABORT;
+ else
+ mark = RXRPC_SKB_MARK_BUSY;
+
+ _debug("post abort/busy");
+ rxrpc_clear_tx_window(call);
+ if (rxrpc_post_message(call, mark, ECONNABORTED, true) < 0)
+ goto no_mem;
+
+ clear_bit(RXRPC_CALL_RCVD_BUSY, &call->events);
+ clear_bit(RXRPC_CALL_RCVD_ABORT, &call->events);
+ goto kill_ACKs;
+ }
+
+ if (test_and_clear_bit(RXRPC_CALL_RCVD_ACKALL, &call->events)) {
+ _debug("do implicit ackall");
+ rxrpc_clear_tx_window(call);
+ }
+
+ if (test_bit(RXRPC_CALL_LIFE_TIMER, &call->events)) {
+ write_lock_bh(&call->state_lock);
+ if (call->state <= RXRPC_CALL_COMPLETE) {
+ call->state = RXRPC_CALL_LOCALLY_ABORTED;
+ call->abort_code = RX_CALL_TIMEOUT;
+ set_bit(RXRPC_CALL_ABORT, &call->events);
+ }
+ write_unlock_bh(&call->state_lock);
+
+ _debug("post timeout");
+ if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR,
+ ETIME, true) < 0)
+ goto no_mem;
+
+ clear_bit(RXRPC_CALL_LIFE_TIMER, &call->events);
+ goto kill_ACKs;
+ }
+
+ /* deal with assorted inbound messages */
+ if (!skb_queue_empty(&call->rx_queue)) {
+ switch (rxrpc_process_rx_queue(call, &abort_code)) {
+ case 0:
+ case -EAGAIN:
+ break;
+ case -ENOMEM:
+ goto no_mem;
+ case -EKEYEXPIRED:
+ case -EKEYREJECTED:
+ case -EPROTO:
+ rxrpc_abort_call(call, abort_code);
+ goto kill_ACKs;
+ }
+ }
+
+ /* handle resending */
+ if (test_and_clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events))
+ rxrpc_resend_timer(call);
+ if (test_and_clear_bit(RXRPC_CALL_RESEND, &call->events))
+ rxrpc_resend(call);
+
+ /* consider sending an ordinary ACK */
+ if (test_bit(RXRPC_CALL_ACK, &call->events)) {
+ __be32 pad;
+
+ _debug("send ACK: window: %d - %d { %lx }",
+ call->rx_data_eaten, call->ackr_win_top,
+ call->ackr_window[0]);
+
+ if (call->state > RXRPC_CALL_SERVER_ACK_REQUEST &&
+ call->ackr_reason != RXRPC_ACK_PING_RESPONSE) {
+ /* ACK by sending reply DATA packet in this state */
+ clear_bit(RXRPC_CALL_ACK, &call->events);
+ goto maybe_reschedule;
+ }
+
+ genbit = RXRPC_CALL_ACK;
+
+ acks = kzalloc(call->ackr_win_top - call->rx_data_eaten,
+ GFP_NOFS);
+ if (!acks)
+ goto no_mem;
+
+ //hdr.flags = RXRPC_SLOW_START_OK;
+ ack.bufferSpace = htons(8);
+ ack.maxSkew = 0;
+ ack.serial = 0;
+ ack.reason = 0;
+
+ ackinfo.rxMTU = htonl(5692);
+// ackinfo.rxMTU = htonl(call->conn->trans->peer->maxdata);
+ ackinfo.maxMTU = htonl(call->conn->trans->peer->maxdata);
+ ackinfo.rwind = htonl(32);
+ ackinfo.jumbo_max = htonl(4);
+
+ spin_lock_bh(&call->lock);
+ ack.reason = call->ackr_reason;
+ ack.serial = call->ackr_serial;
+ ack.previousPacket = call->ackr_prev_seq;
+ ack.firstPacket = htonl(call->rx_data_eaten + 1);
+
+ ack.nAcks = 0;
+ for (loop = 0; loop < RXRPC_ACKR_WINDOW_ASZ; loop++) {
+ nbit = loop * BITS_PER_LONG;
+ for (bits = call->ackr_window[loop]; bits; bits >>= 1
+ ) {
+ _debug("- l=%d n=%d b=%lx", loop, nbit, bits);
+ if (bits & 1) {
+ acks[nbit] = RXRPC_ACK_TYPE_ACK;
+ ack.nAcks = nbit + 1;
+ }
+ nbit++;
+ }
+ }
+ call->ackr_reason = 0;
+ spin_unlock_bh(&call->lock);
+
+ pad = 0;
+
+ iov[1].iov_base = &ack;
+ iov[1].iov_len = sizeof(ack);
+ iov[2].iov_base = acks;
+ iov[2].iov_len = ack.nAcks;
+ iov[3].iov_base = &pad;
+ iov[3].iov_len = 3;
+ iov[4].iov_base = &ackinfo;
+ iov[4].iov_len = sizeof(ackinfo);
+
+ switch (ack.reason) {
+ case RXRPC_ACK_REQUESTED:
+ case RXRPC_ACK_DUPLICATE:
+ case RXRPC_ACK_OUT_OF_SEQUENCE:
+ case RXRPC_ACK_EXCEEDS_WINDOW:
+ case RXRPC_ACK_NOSPACE:
+ case RXRPC_ACK_PING:
+ case RXRPC_ACK_PING_RESPONSE:
+ goto send_ACK_with_skew;
+ case RXRPC_ACK_DELAY:
+ case RXRPC_ACK_IDLE:
+ goto send_ACK;
+ }
+ }
+
+ /* handle completion of security negotiations on an incoming
+ * connection */
+ if (test_and_clear_bit(RXRPC_CALL_SECURED, &call->events)) {
+ _debug("secured");
+ spin_lock_bh(&call->lock);
+
+ if (call->state == RXRPC_CALL_SERVER_SECURING) {
+ _debug("securing");
+ write_lock(&call->conn->lock);
+ if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
+ !test_bit(RXRPC_CALL_RELEASE, &call->events)) {
+ _debug("not released");
+ call->state = RXRPC_CALL_SERVER_ACCEPTING;
+ list_move_tail(&call->accept_link,
+ &call->socket->acceptq);
+ }
+ write_unlock(&call->conn->lock);
+ read_lock(&call->state_lock);
+ if (call->state < RXRPC_CALL_COMPLETE)
+ set_bit(RXRPC_CALL_POST_ACCEPT, &call->events);
+ read_unlock(&call->state_lock);
+ }
+
+ spin_unlock_bh(&call->lock);
+ if (!test_bit(RXRPC_CALL_POST_ACCEPT, &call->events))
+ goto maybe_reschedule;
+ }
+
+ /* post a notification of an acceptable connection to the app */
+ if (test_bit(RXRPC_CALL_POST_ACCEPT, &call->events)) {
+ _debug("post accept");
+ if (rxrpc_post_message(call, RXRPC_SKB_MARK_NEW_CALL,
+ 0, false) < 0)
+ goto no_mem;
+ clear_bit(RXRPC_CALL_POST_ACCEPT, &call->events);
+ goto maybe_reschedule;
+ }
+
+ /* handle incoming call acceptance */
+ if (test_and_clear_bit(RXRPC_CALL_ACCEPTED, &call->events)) {
+ _debug("accepted");
+ ASSERTCMP(call->rx_data_post, ==, 0);
+ call->rx_data_post = 1;
+ read_lock_bh(&call->state_lock);
+ if (call->state < RXRPC_CALL_COMPLETE)
+ set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events);
+ read_unlock_bh(&call->state_lock);
+ }
+
+ /* drain the out of sequence received packet queue into the packet Rx
+ * queue */
+ if (test_and_clear_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events)) {
+ while (call->rx_data_post == call->rx_first_oos)
+ if (rxrpc_drain_rx_oos_queue(call) < 0)
+ break;
+ goto maybe_reschedule;
+ }
+
+ /* other events may have been raised since we started checking */
+ goto maybe_reschedule;
+
+send_ACK_with_skew:
+ ack.maxSkew = htons(atomic_read(&call->conn->hi_serial) -
+ ntohl(ack.serial));
+send_ACK:
+ hdr.serial = htonl(atomic_inc_return(&call->conn->serial));
+ _proto("Tx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }",
+ ntohl(hdr.serial),
+ ntohs(ack.maxSkew),
+ ntohl(ack.firstPacket),
+ ntohl(ack.previousPacket),
+ ntohl(ack.serial),
+ rxrpc_acks[ack.reason],
+ ack.nAcks);
+
+ del_timer_sync(&call->ack_timer);
+ if (ack.nAcks > 0)
+ set_bit(RXRPC_CALL_TX_SOFT_ACK, &call->flags);
+ goto send_message_2;
+
+send_message:
+ _debug("send message");
+
+ hdr.serial = htonl(atomic_inc_return(&call->conn->serial));
+ _proto("Tx %s %%%u", rxrpc_pkts[hdr.type], ntohl(hdr.serial));
+send_message_2:
+
+ len = iov[0].iov_len;
+ ioc = 1;
+ if (iov[4].iov_len) {
+ ioc = 5;
+ len += iov[4].iov_len;
+ len += iov[3].iov_len;
+ len += iov[2].iov_len;
+ len += iov[1].iov_len;
+ } else if (iov[3].iov_len) {
+ ioc = 4;
+ len += iov[3].iov_len;
+ len += iov[2].iov_len;
+ len += iov[1].iov_len;
+ } else if (iov[2].iov_len) {
+ ioc = 3;
+ len += iov[2].iov_len;
+ len += iov[1].iov_len;
+ } else if (iov[1].iov_len) {
+ ioc = 2;
+ len += iov[1].iov_len;
+ }
+
+ ret = kernel_sendmsg(call->conn->trans->local->socket,
+ &msg, iov, ioc, len);
+ if (ret < 0) {
+ _debug("sendmsg failed: %d", ret);
+ read_lock_bh(&call->state_lock);
+ if (call->state < RXRPC_CALL_DEAD)
+ schedule_work(&call->processor);
+ read_unlock_bh(&call->state_lock);
+ goto error;
+ }
+
+ switch (genbit) {
+ case RXRPC_CALL_ABORT:
+ clear_bit(genbit, &call->events);
+ clear_bit(RXRPC_CALL_RCVD_ABORT, &call->events);
+ goto kill_ACKs;
+
+ case RXRPC_CALL_ACK_FINAL:
+ write_lock_bh(&call->state_lock);
+ if (call->state == RXRPC_CALL_CLIENT_FINAL_ACK)
+ call->state = RXRPC_CALL_COMPLETE;
+ write_unlock_bh(&call->state_lock);
+ goto kill_ACKs;
+
+ default:
+ clear_bit(genbit, &call->events);
+ switch (call->state) {
+ case RXRPC_CALL_CLIENT_AWAIT_REPLY:
+ case RXRPC_CALL_CLIENT_RECV_REPLY:
+ case RXRPC_CALL_SERVER_RECV_REQUEST:
+ case RXRPC_CALL_SERVER_ACK_REQUEST:
+ _debug("start ACK timer");
+ rxrpc_propose_ACK(call, RXRPC_ACK_DELAY,
+ call->ackr_serial, false);
+ default:
+ break;
+ }
+ goto maybe_reschedule;
+ }
+
+kill_ACKs:
+ del_timer_sync(&call->ack_timer);
+ if (test_and_clear_bit(RXRPC_CALL_ACK_FINAL, &call->events))
+ rxrpc_put_call(call);
+ clear_bit(RXRPC_CALL_ACK, &call->events);
+
+maybe_reschedule:
+ if (call->events || !skb_queue_empty(&call->rx_queue)) {
+ read_lock_bh(&call->state_lock);
+ if (call->state < RXRPC_CALL_DEAD)
+ schedule_work(&call->processor);
+ read_unlock_bh(&call->state_lock);
+ }
+
+ /* don't leave aborted connections on the accept queue */
+ if (call->state >= RXRPC_CALL_COMPLETE &&
+ !list_empty(&call->accept_link)) {
+ _debug("X unlinking once-pending call %p { e=%lx f=%lx c=%x }",
+ call, call->events, call->flags,
+ ntohl(call->conn->cid));
+
+ read_lock_bh(&call->state_lock);
+ if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
+ !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
+ schedule_work(&call->processor);
+ read_unlock_bh(&call->state_lock);
+ }
+
+error:
+ clear_bit(RXRPC_CALL_PROC_BUSY, &call->flags);
+ kfree(acks);
+
+ /* because we don't want two CPUs both processing the work item for one
+ * call at the same time, we use a flag to note when it's busy; however
+ * this means there's a race between clearing the flag and setting the
+ * work pending bit and the work item being processed again */
+ if (call->events && !work_pending(&call->processor)) {
+ _debug("jumpstart %x", ntohl(call->conn->cid));
+ schedule_work(&call->processor);
+ }
+
+ _leave("");
+ return;
+
+no_mem:
+ _debug("out of memory");
+ goto maybe_reschedule;
+}

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