[Feature] add GA346 baseline version
Change-Id: Ic62933698569507dcf98240cdf5d9931ae34348f
diff --git a/src/kernel/linux/v4.19/net/rxrpc/input.c b/src/kernel/linux/v4.19/net/rxrpc/input.c
new file mode 100644
index 0000000..7965600
--- /dev/null
+++ b/src/kernel/linux/v4.19/net/rxrpc/input.c
@@ -0,0 +1,1423 @@
+/* RxRPC packet reception
+ *
+ * Copyright (C) 2007, 2016 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.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/errqueue.h>
+#include <linux/udp.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/icmp.h>
+#include <linux/gfp.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <net/ip.h>
+#include <net/udp.h>
+#include <net/net_namespace.h>
+#include "ar-internal.h"
+
+static void rxrpc_proto_abort(const char *why,
+ struct rxrpc_call *call, rxrpc_seq_t seq)
+{
+ if (rxrpc_abort_call(why, call, seq, RX_PROTOCOL_ERROR, -EBADMSG)) {
+ set_bit(RXRPC_CALL_EV_ABORT, &call->events);
+ rxrpc_queue_call(call);
+ }
+}
+
+/*
+ * Do TCP-style congestion management [RFC 5681].
+ */
+static void rxrpc_congestion_management(struct rxrpc_call *call,
+ struct sk_buff *skb,
+ struct rxrpc_ack_summary *summary,
+ rxrpc_serial_t acked_serial)
+{
+ enum rxrpc_congest_change change = rxrpc_cong_no_change;
+ unsigned int cumulative_acks = call->cong_cumul_acks;
+ unsigned int cwnd = call->cong_cwnd;
+ bool resend = false;
+
+ summary->flight_size =
+ (call->tx_top - call->tx_hard_ack) - summary->nr_acks;
+
+ if (test_and_clear_bit(RXRPC_CALL_RETRANS_TIMEOUT, &call->flags)) {
+ summary->retrans_timeo = true;
+ call->cong_ssthresh = max_t(unsigned int,
+ summary->flight_size / 2, 2);
+ cwnd = 1;
+ if (cwnd >= call->cong_ssthresh &&
+ call->cong_mode == RXRPC_CALL_SLOW_START) {
+ call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
+ call->cong_tstamp = skb->tstamp;
+ cumulative_acks = 0;
+ }
+ }
+
+ cumulative_acks += summary->nr_new_acks;
+ cumulative_acks += summary->nr_rot_new_acks;
+ if (cumulative_acks > 255)
+ cumulative_acks = 255;
+
+ summary->mode = call->cong_mode;
+ summary->cwnd = call->cong_cwnd;
+ summary->ssthresh = call->cong_ssthresh;
+ summary->cumulative_acks = cumulative_acks;
+ summary->dup_acks = call->cong_dup_acks;
+
+ switch (call->cong_mode) {
+ case RXRPC_CALL_SLOW_START:
+ if (summary->nr_nacks > 0)
+ goto packet_loss_detected;
+ if (summary->cumulative_acks > 0)
+ cwnd += 1;
+ if (cwnd >= call->cong_ssthresh) {
+ call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
+ call->cong_tstamp = skb->tstamp;
+ }
+ goto out;
+
+ case RXRPC_CALL_CONGEST_AVOIDANCE:
+ if (summary->nr_nacks > 0)
+ goto packet_loss_detected;
+
+ /* We analyse the number of packets that get ACK'd per RTT
+ * period and increase the window if we managed to fill it.
+ */
+ if (call->peer->rtt_usage == 0)
+ goto out;
+ if (ktime_before(skb->tstamp,
+ ktime_add_ns(call->cong_tstamp,
+ call->peer->rtt)))
+ goto out_no_clear_ca;
+ change = rxrpc_cong_rtt_window_end;
+ call->cong_tstamp = skb->tstamp;
+ if (cumulative_acks >= cwnd)
+ cwnd++;
+ goto out;
+
+ case RXRPC_CALL_PACKET_LOSS:
+ if (summary->nr_nacks == 0)
+ goto resume_normality;
+
+ if (summary->new_low_nack) {
+ change = rxrpc_cong_new_low_nack;
+ call->cong_dup_acks = 1;
+ if (call->cong_extra > 1)
+ call->cong_extra = 1;
+ goto send_extra_data;
+ }
+
+ call->cong_dup_acks++;
+ if (call->cong_dup_acks < 3)
+ goto send_extra_data;
+
+ change = rxrpc_cong_begin_retransmission;
+ call->cong_mode = RXRPC_CALL_FAST_RETRANSMIT;
+ call->cong_ssthresh = max_t(unsigned int,
+ summary->flight_size / 2, 2);
+ cwnd = call->cong_ssthresh + 3;
+ call->cong_extra = 0;
+ call->cong_dup_acks = 0;
+ resend = true;
+ goto out;
+
+ case RXRPC_CALL_FAST_RETRANSMIT:
+ if (!summary->new_low_nack) {
+ if (summary->nr_new_acks == 0)
+ cwnd += 1;
+ call->cong_dup_acks++;
+ if (call->cong_dup_acks == 2) {
+ change = rxrpc_cong_retransmit_again;
+ call->cong_dup_acks = 0;
+ resend = true;
+ }
+ } else {
+ change = rxrpc_cong_progress;
+ cwnd = call->cong_ssthresh;
+ if (summary->nr_nacks == 0)
+ goto resume_normality;
+ }
+ goto out;
+
+ default:
+ BUG();
+ goto out;
+ }
+
+resume_normality:
+ change = rxrpc_cong_cleared_nacks;
+ call->cong_dup_acks = 0;
+ call->cong_extra = 0;
+ call->cong_tstamp = skb->tstamp;
+ if (cwnd < call->cong_ssthresh)
+ call->cong_mode = RXRPC_CALL_SLOW_START;
+ else
+ call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
+out:
+ cumulative_acks = 0;
+out_no_clear_ca:
+ if (cwnd >= RXRPC_RXTX_BUFF_SIZE - 1)
+ cwnd = RXRPC_RXTX_BUFF_SIZE - 1;
+ call->cong_cwnd = cwnd;
+ call->cong_cumul_acks = cumulative_acks;
+ trace_rxrpc_congest(call, summary, acked_serial, change);
+ if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
+ rxrpc_queue_call(call);
+ return;
+
+packet_loss_detected:
+ change = rxrpc_cong_saw_nack;
+ call->cong_mode = RXRPC_CALL_PACKET_LOSS;
+ call->cong_dup_acks = 0;
+ goto send_extra_data;
+
+send_extra_data:
+ /* Send some previously unsent DATA if we have some to advance the ACK
+ * state.
+ */
+ if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] &
+ RXRPC_TX_ANNO_LAST ||
+ summary->nr_acks != call->tx_top - call->tx_hard_ack) {
+ call->cong_extra++;
+ wake_up(&call->waitq);
+ }
+ goto out_no_clear_ca;
+}
+
+/*
+ * Ping the other end to fill our RTT cache and to retrieve the rwind
+ * and MTU parameters.
+ */
+static void rxrpc_send_ping(struct rxrpc_call *call, struct sk_buff *skb,
+ int skew)
+{
+ struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+ ktime_t now = skb->tstamp;
+
+ if (call->peer->rtt_usage < 3 ||
+ ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), now))
+ rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial,
+ true, true,
+ rxrpc_propose_ack_ping_for_params);
+}
+
+/*
+ * Apply a hard ACK by advancing the Tx window.
+ */
+static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to,
+ struct rxrpc_ack_summary *summary)
+{
+ struct sk_buff *skb, *list = NULL;
+ bool rot_last = false;
+ int ix;
+ u8 annotation;
+
+ if (call->acks_lowest_nak == call->tx_hard_ack) {
+ call->acks_lowest_nak = to;
+ } else if (before_eq(call->acks_lowest_nak, to)) {
+ summary->new_low_nack = true;
+ call->acks_lowest_nak = to;
+ }
+
+ spin_lock(&call->lock);
+
+ while (before(call->tx_hard_ack, to)) {
+ call->tx_hard_ack++;
+ ix = call->tx_hard_ack & RXRPC_RXTX_BUFF_MASK;
+ skb = call->rxtx_buffer[ix];
+ annotation = call->rxtx_annotations[ix];
+ rxrpc_see_skb(skb, rxrpc_skb_tx_rotated);
+ call->rxtx_buffer[ix] = NULL;
+ call->rxtx_annotations[ix] = 0;
+ skb->next = list;
+ list = skb;
+
+ if (annotation & RXRPC_TX_ANNO_LAST) {
+ set_bit(RXRPC_CALL_TX_LAST, &call->flags);
+ rot_last = true;
+ }
+ if ((annotation & RXRPC_TX_ANNO_MASK) != RXRPC_TX_ANNO_ACK)
+ summary->nr_rot_new_acks++;
+ }
+
+ spin_unlock(&call->lock);
+
+ trace_rxrpc_transmit(call, (rot_last ?
+ rxrpc_transmit_rotate_last :
+ rxrpc_transmit_rotate));
+ wake_up(&call->waitq);
+
+ while (list) {
+ skb = list;
+ list = skb->next;
+ skb->next = NULL;
+ rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
+ }
+
+ return rot_last;
+}
+
+/*
+ * End the transmission phase of a call.
+ *
+ * This occurs when we get an ACKALL packet, the first DATA packet of a reply,
+ * or a final ACK packet.
+ */
+static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun,
+ const char *abort_why)
+{
+ unsigned int state;
+
+ ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags));
+
+ write_lock(&call->state_lock);
+
+ state = call->state;
+ switch (state) {
+ case RXRPC_CALL_CLIENT_SEND_REQUEST:
+ case RXRPC_CALL_CLIENT_AWAIT_REPLY:
+ if (reply_begun)
+ call->state = state = RXRPC_CALL_CLIENT_RECV_REPLY;
+ else
+ call->state = state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
+ break;
+
+ case RXRPC_CALL_SERVER_AWAIT_ACK:
+ __rxrpc_call_completed(call);
+ rxrpc_notify_socket(call);
+ state = call->state;
+ break;
+
+ default:
+ goto bad_state;
+ }
+
+ write_unlock(&call->state_lock);
+ if (state == RXRPC_CALL_CLIENT_AWAIT_REPLY)
+ trace_rxrpc_transmit(call, rxrpc_transmit_await_reply);
+ else
+ trace_rxrpc_transmit(call, rxrpc_transmit_end);
+ _leave(" = ok");
+ return true;
+
+bad_state:
+ write_unlock(&call->state_lock);
+ kdebug("end_tx %s", rxrpc_call_states[call->state]);
+ rxrpc_proto_abort(abort_why, call, call->tx_top);
+ return false;
+}
+
+/*
+ * Begin the reply reception phase of a call.
+ */
+static bool rxrpc_receiving_reply(struct rxrpc_call *call)
+{
+ struct rxrpc_ack_summary summary = { 0 };
+ unsigned long now, timo;
+ rxrpc_seq_t top = READ_ONCE(call->tx_top);
+
+ if (call->ackr_reason) {
+ spin_lock_bh(&call->lock);
+ call->ackr_reason = 0;
+ spin_unlock_bh(&call->lock);
+ now = jiffies;
+ timo = now + MAX_JIFFY_OFFSET;
+ WRITE_ONCE(call->resend_at, timo);
+ WRITE_ONCE(call->ack_at, timo);
+ trace_rxrpc_timer(call, rxrpc_timer_init_for_reply, now);
+ }
+
+ if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) {
+ if (!rxrpc_rotate_tx_window(call, top, &summary)) {
+ rxrpc_proto_abort("TXL", call, top);
+ return false;
+ }
+ }
+ if (!rxrpc_end_tx_phase(call, true, "ETD"))
+ return false;
+ call->tx_phase = false;
+ return true;
+}
+
+/*
+ * Scan a jumbo packet to validate its structure and to work out how many
+ * subpackets it contains.
+ *
+ * A jumbo packet is a collection of consecutive packets glued together with
+ * little headers between that indicate how to change the initial header for
+ * each subpacket.
+ *
+ * RXRPC_JUMBO_PACKET must be set on all but the last subpacket - and all but
+ * the last are RXRPC_JUMBO_DATALEN in size. The last subpacket may be of any
+ * size.
+ */
+static bool rxrpc_validate_jumbo(struct sk_buff *skb)
+{
+ struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+ unsigned int offset = sizeof(struct rxrpc_wire_header);
+ unsigned int len = skb->len;
+ int nr_jumbo = 1;
+ u8 flags = sp->hdr.flags;
+
+ do {
+ nr_jumbo++;
+ if (len - offset < RXRPC_JUMBO_SUBPKTLEN)
+ goto protocol_error;
+ if (flags & RXRPC_LAST_PACKET)
+ goto protocol_error;
+ offset += RXRPC_JUMBO_DATALEN;
+ if (skb_copy_bits(skb, offset, &flags, 1) < 0)
+ goto protocol_error;
+ offset += sizeof(struct rxrpc_jumbo_header);
+ } while (flags & RXRPC_JUMBO_PACKET);
+
+ sp->nr_jumbo = nr_jumbo;
+ return true;
+
+protocol_error:
+ return false;
+}
+
+/*
+ * Handle reception of a duplicate packet.
+ *
+ * We have to take care to avoid an attack here whereby we're given a series of
+ * jumbograms, each with a sequence number one before the preceding one and
+ * filled up to maximum UDP size. If they never send us the first packet in
+ * the sequence, they can cause us to have to hold on to around 2MiB of kernel
+ * space until the call times out.
+ *
+ * We limit the space usage by only accepting three duplicate jumbo packets per
+ * call. After that, we tell the other side we're no longer accepting jumbos
+ * (that information is encoded in the ACK packet).
+ */
+static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq,
+ u8 annotation, bool *_jumbo_bad)
+{
+ /* Discard normal packets that are duplicates. */
+ if (annotation == 0)
+ return;
+
+ /* Skip jumbo subpackets that are duplicates. When we've had three or
+ * more partially duplicate jumbo packets, we refuse to take any more
+ * jumbos for this call.
+ */
+ if (!*_jumbo_bad) {
+ call->nr_jumbo_bad++;
+ *_jumbo_bad = true;
+ }
+}
+
+/*
+ * Process a DATA packet, adding the packet to the Rx ring.
+ */
+static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb,
+ u16 skew)
+{
+ struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+ enum rxrpc_call_state state;
+ unsigned int offset = sizeof(struct rxrpc_wire_header);
+ unsigned int ix;
+ rxrpc_serial_t serial = sp->hdr.serial, ack_serial = 0;
+ rxrpc_seq_t seq = sp->hdr.seq, hard_ack;
+ bool immediate_ack = false, jumbo_bad = false, queued;
+ u16 len;
+ u8 ack = 0, flags, annotation = 0;
+
+ _enter("{%u,%u},{%u,%u}",
+ call->rx_hard_ack, call->rx_top, skb->len, seq);
+
+ _proto("Rx DATA %%%u { #%u f=%02x }",
+ sp->hdr.serial, seq, sp->hdr.flags);
+
+ state = READ_ONCE(call->state);
+ if (state >= RXRPC_CALL_COMPLETE)
+ return;
+
+ if (call->state == RXRPC_CALL_SERVER_RECV_REQUEST) {
+ unsigned long timo = READ_ONCE(call->next_req_timo);
+ unsigned long now, expect_req_by;
+
+ if (timo) {
+ now = jiffies;
+ expect_req_by = now + timo;
+ WRITE_ONCE(call->expect_req_by, expect_req_by);
+ rxrpc_reduce_call_timer(call, expect_req_by, now,
+ rxrpc_timer_set_for_idle);
+ }
+ }
+
+ spin_lock(&call->input_lock);
+
+ /* Received data implicitly ACKs all of the request packets we sent
+ * when we're acting as a client.
+ */
+ if ((state == RXRPC_CALL_CLIENT_SEND_REQUEST ||
+ state == RXRPC_CALL_CLIENT_AWAIT_REPLY) &&
+ !rxrpc_receiving_reply(call))
+ goto unlock;
+
+ call->ackr_prev_seq = seq;
+
+ hard_ack = READ_ONCE(call->rx_hard_ack);
+ if (after(seq, hard_ack + call->rx_winsize)) {
+ ack = RXRPC_ACK_EXCEEDS_WINDOW;
+ ack_serial = serial;
+ goto ack;
+ }
+
+ flags = sp->hdr.flags;
+ if (flags & RXRPC_JUMBO_PACKET) {
+ if (call->nr_jumbo_bad > 3) {
+ ack = RXRPC_ACK_NOSPACE;
+ ack_serial = serial;
+ goto ack;
+ }
+ annotation = 1;
+ }
+
+next_subpacket:
+ queued = false;
+ ix = seq & RXRPC_RXTX_BUFF_MASK;
+ len = skb->len;
+ if (flags & RXRPC_JUMBO_PACKET)
+ len = RXRPC_JUMBO_DATALEN;
+
+ if (flags & RXRPC_LAST_PACKET) {
+ if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
+ seq != call->rx_top) {
+ rxrpc_proto_abort("LSN", call, seq);
+ goto unlock;
+ }
+ } else {
+ if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
+ after_eq(seq, call->rx_top)) {
+ rxrpc_proto_abort("LSA", call, seq);
+ goto unlock;
+ }
+ }
+
+ trace_rxrpc_rx_data(call->debug_id, seq, serial, flags, annotation);
+ if (before_eq(seq, hard_ack)) {
+ ack = RXRPC_ACK_DUPLICATE;
+ ack_serial = serial;
+ goto skip;
+ }
+
+ if (flags & RXRPC_REQUEST_ACK && !ack) {
+ ack = RXRPC_ACK_REQUESTED;
+ ack_serial = serial;
+ }
+
+ if (call->rxtx_buffer[ix]) {
+ rxrpc_input_dup_data(call, seq, annotation, &jumbo_bad);
+ if (ack != RXRPC_ACK_DUPLICATE) {
+ ack = RXRPC_ACK_DUPLICATE;
+ ack_serial = serial;
+ }
+ immediate_ack = true;
+ goto skip;
+ }
+
+ /* Queue the packet. We use a couple of memory barriers here as need
+ * to make sure that rx_top is perceived to be set after the buffer
+ * pointer and that the buffer pointer is set after the annotation and
+ * the skb data.
+ *
+ * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window()
+ * and also rxrpc_fill_out_ack().
+ */
+ rxrpc_get_skb(skb, rxrpc_skb_rx_got);
+ call->rxtx_annotations[ix] = annotation;
+ smp_wmb();
+ call->rxtx_buffer[ix] = skb;
+ if (after(seq, call->rx_top)) {
+ smp_store_release(&call->rx_top, seq);
+ } else if (before(seq, call->rx_top)) {
+ /* Send an immediate ACK if we fill in a hole */
+ if (!ack) {
+ ack = RXRPC_ACK_DELAY;
+ ack_serial = serial;
+ }
+ immediate_ack = true;
+ }
+ if (flags & RXRPC_LAST_PACKET) {
+ set_bit(RXRPC_CALL_RX_LAST, &call->flags);
+ trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq);
+ } else {
+ trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq);
+ }
+ queued = true;
+
+ if (after_eq(seq, call->rx_expect_next)) {
+ if (after(seq, call->rx_expect_next)) {
+ _net("OOS %u > %u", seq, call->rx_expect_next);
+ ack = RXRPC_ACK_OUT_OF_SEQUENCE;
+ ack_serial = serial;
+ }
+ call->rx_expect_next = seq + 1;
+ }
+
+skip:
+ offset += len;
+ if (flags & RXRPC_JUMBO_PACKET) {
+ if (skb_copy_bits(skb, offset, &flags, 1) < 0) {
+ rxrpc_proto_abort("XJF", call, seq);
+ goto unlock;
+ }
+ offset += sizeof(struct rxrpc_jumbo_header);
+ seq++;
+ serial++;
+ annotation++;
+ if (flags & RXRPC_JUMBO_PACKET)
+ annotation |= RXRPC_RX_ANNO_JLAST;
+ if (after(seq, hard_ack + call->rx_winsize)) {
+ ack = RXRPC_ACK_EXCEEDS_WINDOW;
+ ack_serial = serial;
+ if (!jumbo_bad) {
+ call->nr_jumbo_bad++;
+ jumbo_bad = true;
+ }
+ goto ack;
+ }
+
+ _proto("Rx DATA Jumbo %%%u", serial);
+ goto next_subpacket;
+ }
+
+ if (queued && flags & RXRPC_LAST_PACKET && !ack) {
+ ack = RXRPC_ACK_DELAY;
+ ack_serial = serial;
+ }
+
+ack:
+ if (ack)
+ rxrpc_propose_ACK(call, ack, skew, ack_serial,
+ immediate_ack, true,
+ rxrpc_propose_ack_input_data);
+ else
+ rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, skew, serial,
+ false, true,
+ rxrpc_propose_ack_input_data);
+
+ if (sp->hdr.seq == READ_ONCE(call->rx_hard_ack) + 1) {
+ trace_rxrpc_notify_socket(call->debug_id, serial);
+ rxrpc_notify_socket(call);
+ }
+
+unlock:
+ spin_unlock(&call->input_lock);
+ _leave(" [queued]");
+}
+
+/*
+ * Process a requested ACK.
+ */
+static void rxrpc_input_requested_ack(struct rxrpc_call *call,
+ ktime_t resp_time,
+ rxrpc_serial_t orig_serial,
+ rxrpc_serial_t ack_serial)
+{
+ struct rxrpc_skb_priv *sp;
+ struct sk_buff *skb;
+ ktime_t sent_at;
+ int ix;
+
+ for (ix = 0; ix < RXRPC_RXTX_BUFF_SIZE; ix++) {
+ skb = call->rxtx_buffer[ix];
+ if (!skb)
+ continue;
+
+ sent_at = skb->tstamp;
+ smp_rmb(); /* Read timestamp before serial. */
+ sp = rxrpc_skb(skb);
+ if (sp->hdr.serial != orig_serial)
+ continue;
+ goto found;
+ }
+
+ return;
+
+found:
+ rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_requested_ack,
+ orig_serial, ack_serial, sent_at, resp_time);
+}
+
+/*
+ * Process the response to a ping that we sent to find out if we lost an ACK.
+ *
+ * If we got back a ping response that indicates a lower tx_top than what we
+ * had at the time of the ping transmission, we adjudge all the DATA packets
+ * sent between the response tx_top and the ping-time tx_top to have been lost.
+ */
+static void rxrpc_input_check_for_lost_ack(struct rxrpc_call *call)
+{
+ rxrpc_seq_t top, bottom, seq;
+ bool resend = false;
+
+ spin_lock_bh(&call->lock);
+
+ bottom = call->tx_hard_ack + 1;
+ top = call->acks_lost_top;
+ if (before(bottom, top)) {
+ for (seq = bottom; before_eq(seq, top); seq++) {
+ int ix = seq & RXRPC_RXTX_BUFF_MASK;
+ u8 annotation = call->rxtx_annotations[ix];
+ u8 anno_type = annotation & RXRPC_TX_ANNO_MASK;
+
+ if (anno_type != RXRPC_TX_ANNO_UNACK)
+ continue;
+ annotation &= ~RXRPC_TX_ANNO_MASK;
+ annotation |= RXRPC_TX_ANNO_RETRANS;
+ call->rxtx_annotations[ix] = annotation;
+ resend = true;
+ }
+ }
+
+ spin_unlock_bh(&call->lock);
+
+ if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
+ rxrpc_queue_call(call);
+}
+
+/*
+ * Process a ping response.
+ */
+static void rxrpc_input_ping_response(struct rxrpc_call *call,
+ ktime_t resp_time,
+ rxrpc_serial_t orig_serial,
+ rxrpc_serial_t ack_serial)
+{
+ rxrpc_serial_t ping_serial;
+ ktime_t ping_time;
+
+ ping_time = call->ping_time;
+ smp_rmb();
+ ping_serial = READ_ONCE(call->ping_serial);
+
+ if (orig_serial == call->acks_lost_ping)
+ rxrpc_input_check_for_lost_ack(call);
+
+ if (before(orig_serial, ping_serial) ||
+ !test_and_clear_bit(RXRPC_CALL_PINGING, &call->flags))
+ return;
+ if (after(orig_serial, ping_serial))
+ return;
+
+ rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_ping_response,
+ orig_serial, ack_serial, ping_time, resp_time);
+}
+
+/*
+ * Process the extra information that may be appended to an ACK packet
+ */
+static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb,
+ struct rxrpc_ackinfo *ackinfo)
+{
+ struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+ struct rxrpc_peer *peer;
+ unsigned int mtu;
+ bool wake = false;
+ u32 rwind = ntohl(ackinfo->rwind);
+
+ _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }",
+ sp->hdr.serial,
+ ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU),
+ rwind, ntohl(ackinfo->jumbo_max));
+
+ if (call->tx_winsize != rwind) {
+ if (rwind > RXRPC_RXTX_BUFF_SIZE - 1)
+ rwind = RXRPC_RXTX_BUFF_SIZE - 1;
+ if (rwind > call->tx_winsize)
+ wake = true;
+ trace_rxrpc_rx_rwind_change(call, sp->hdr.serial,
+ ntohl(ackinfo->rwind), wake);
+ call->tx_winsize = rwind;
+ }
+
+ if (call->cong_ssthresh > rwind)
+ call->cong_ssthresh = rwind;
+
+ mtu = min(ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU));
+
+ peer = call->peer;
+ if (mtu < peer->maxdata) {
+ spin_lock_bh(&peer->lock);
+ peer->maxdata = mtu;
+ peer->mtu = mtu + peer->hdrsize;
+ spin_unlock_bh(&peer->lock);
+ _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata);
+ }
+
+ if (wake)
+ wake_up(&call->waitq);
+}
+
+/*
+ * Process individual soft ACKs.
+ *
+ * Each ACK in the array corresponds to one packet and can be either an ACK or
+ * a NAK. If we get find an explicitly NAK'd packet we resend immediately;
+ * packets that lie beyond the end of the ACK list are scheduled for resend by
+ * the timer on the basis that the peer might just not have processed them at
+ * the time the ACK was sent.
+ */
+static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks,
+ rxrpc_seq_t seq, int nr_acks,
+ struct rxrpc_ack_summary *summary)
+{
+ int ix;
+ u8 annotation, anno_type;
+
+ for (; nr_acks > 0; nr_acks--, seq++) {
+ ix = seq & RXRPC_RXTX_BUFF_MASK;
+ annotation = call->rxtx_annotations[ix];
+ anno_type = annotation & RXRPC_TX_ANNO_MASK;
+ annotation &= ~RXRPC_TX_ANNO_MASK;
+ switch (*acks++) {
+ case RXRPC_ACK_TYPE_ACK:
+ summary->nr_acks++;
+ if (anno_type == RXRPC_TX_ANNO_ACK)
+ continue;
+ summary->nr_new_acks++;
+ call->rxtx_annotations[ix] =
+ RXRPC_TX_ANNO_ACK | annotation;
+ break;
+ case RXRPC_ACK_TYPE_NACK:
+ if (!summary->nr_nacks &&
+ call->acks_lowest_nak != seq) {
+ call->acks_lowest_nak = seq;
+ summary->new_low_nack = true;
+ }
+ summary->nr_nacks++;
+ if (anno_type == RXRPC_TX_ANNO_NAK)
+ continue;
+ summary->nr_new_nacks++;
+ if (anno_type == RXRPC_TX_ANNO_RETRANS)
+ continue;
+ call->rxtx_annotations[ix] =
+ RXRPC_TX_ANNO_NAK | annotation;
+ break;
+ default:
+ return rxrpc_proto_abort("SFT", call, 0);
+ }
+ }
+}
+
+/*
+ * Process an ACK packet.
+ *
+ * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet
+ * in the ACK array. Anything before that is hard-ACK'd and may be discarded.
+ *
+ * A hard-ACK means that a packet has been processed and may be discarded; a
+ * soft-ACK means that the packet may be discarded and retransmission
+ * requested. A phase is complete when all packets are hard-ACK'd.
+ */
+static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb,
+ u16 skew)
+{
+ struct rxrpc_ack_summary summary = { 0 };
+ struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+ union {
+ struct rxrpc_ackpacket ack;
+ struct rxrpc_ackinfo info;
+ u8 acks[RXRPC_MAXACKS];
+ } buf;
+ rxrpc_serial_t acked_serial;
+ rxrpc_seq_t first_soft_ack, hard_ack;
+ int nr_acks, offset, ioffset;
+
+ _enter("");
+
+ offset = sizeof(struct rxrpc_wire_header);
+ if (skb_copy_bits(skb, offset, &buf.ack, sizeof(buf.ack)) < 0) {
+ _debug("extraction failure");
+ return rxrpc_proto_abort("XAK", call, 0);
+ }
+ offset += sizeof(buf.ack);
+
+ acked_serial = ntohl(buf.ack.serial);
+ first_soft_ack = ntohl(buf.ack.firstPacket);
+ hard_ack = first_soft_ack - 1;
+ nr_acks = buf.ack.nAcks;
+ summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ?
+ buf.ack.reason : RXRPC_ACK__INVALID);
+
+ trace_rxrpc_rx_ack(call, sp->hdr.serial, acked_serial,
+ first_soft_ack, ntohl(buf.ack.previousPacket),
+ summary.ack_reason, nr_acks);
+
+ if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE)
+ rxrpc_input_ping_response(call, skb->tstamp, acked_serial,
+ sp->hdr.serial);
+ if (buf.ack.reason == RXRPC_ACK_REQUESTED)
+ rxrpc_input_requested_ack(call, skb->tstamp, acked_serial,
+ sp->hdr.serial);
+
+ if (buf.ack.reason == RXRPC_ACK_PING) {
+ _proto("Rx ACK %%%u PING Request", sp->hdr.serial);
+ rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE,
+ skew, sp->hdr.serial, true, true,
+ rxrpc_propose_ack_respond_to_ping);
+ } else if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
+ rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED,
+ skew, sp->hdr.serial, true, true,
+ rxrpc_propose_ack_respond_to_ack);
+ }
+
+ /* Discard any out-of-order or duplicate ACKs. */
+ if (before_eq(sp->hdr.serial, call->acks_latest))
+ return;
+
+ buf.info.rxMTU = 0;
+ ioffset = offset + nr_acks + 3;
+ if (skb->len >= ioffset + sizeof(buf.info) &&
+ skb_copy_bits(skb, ioffset, &buf.info, sizeof(buf.info)) < 0)
+ return rxrpc_proto_abort("XAI", call, 0);
+
+ spin_lock(&call->input_lock);
+
+ /* Discard any out-of-order or duplicate ACKs. */
+ if (before_eq(sp->hdr.serial, call->acks_latest))
+ goto out;
+ call->acks_latest_ts = skb->tstamp;
+ call->acks_latest = sp->hdr.serial;
+
+ /* Parse rwind and mtu sizes if provided. */
+ if (buf.info.rxMTU)
+ rxrpc_input_ackinfo(call, skb, &buf.info);
+
+ if (first_soft_ack == 0) {
+ rxrpc_proto_abort("AK0", call, 0);
+ goto out;
+ }
+
+ /* Ignore ACKs unless we are or have just been transmitting. */
+ switch (READ_ONCE(call->state)) {
+ case RXRPC_CALL_CLIENT_SEND_REQUEST:
+ case RXRPC_CALL_CLIENT_AWAIT_REPLY:
+ case RXRPC_CALL_SERVER_SEND_REPLY:
+ case RXRPC_CALL_SERVER_AWAIT_ACK:
+ break;
+ default:
+ goto out;
+ }
+
+ if (before(hard_ack, call->tx_hard_ack) ||
+ after(hard_ack, call->tx_top)) {
+ rxrpc_proto_abort("AKW", call, 0);
+ goto out;
+ }
+ if (nr_acks > call->tx_top - hard_ack) {
+ rxrpc_proto_abort("AKN", call, 0);
+ goto out;
+ }
+
+ if (after(hard_ack, call->tx_hard_ack)) {
+ if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) {
+ rxrpc_end_tx_phase(call, false, "ETA");
+ goto out;
+ }
+ }
+
+ if (nr_acks > 0) {
+ if (skb_copy_bits(skb, offset, buf.acks, nr_acks) < 0) {
+ rxrpc_proto_abort("XSA", call, 0);
+ goto out;
+ }
+ rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks,
+ &summary);
+ }
+
+ if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] &
+ RXRPC_TX_ANNO_LAST &&
+ summary.nr_acks == call->tx_top - hard_ack &&
+ rxrpc_is_client_call(call))
+ rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial,
+ false, true,
+ rxrpc_propose_ack_ping_for_lost_reply);
+
+ rxrpc_congestion_management(call, skb, &summary, acked_serial);
+out:
+ spin_unlock(&call->input_lock);
+}
+
+/*
+ * Process an ACKALL packet.
+ */
+static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb)
+{
+ struct rxrpc_ack_summary summary = { 0 };
+ struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+ _proto("Rx ACKALL %%%u", sp->hdr.serial);
+
+ spin_lock(&call->input_lock);
+
+ if (rxrpc_rotate_tx_window(call, call->tx_top, &summary))
+ rxrpc_end_tx_phase(call, false, "ETL");
+
+ spin_unlock(&call->input_lock);
+}
+
+/*
+ * Process an ABORT packet directed at a call.
+ */
+static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb)
+{
+ struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+ __be32 wtmp;
+ u32 abort_code = RX_CALL_DEAD;
+
+ _enter("");
+
+ if (skb->len >= 4 &&
+ skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
+ &wtmp, sizeof(wtmp)) >= 0)
+ abort_code = ntohl(wtmp);
+
+ trace_rxrpc_rx_abort(call, sp->hdr.serial, abort_code);
+
+ _proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code);
+
+ if (rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
+ abort_code, -ECONNABORTED))
+ rxrpc_notify_socket(call);
+}
+
+/*
+ * Process an incoming call packet.
+ */
+static void rxrpc_input_call_packet(struct rxrpc_call *call,
+ struct sk_buff *skb, u16 skew)
+{
+ struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+ unsigned long timo;
+
+ _enter("%p,%p", call, skb);
+
+ timo = READ_ONCE(call->next_rx_timo);
+ if (timo) {
+ unsigned long now = jiffies, expect_rx_by;
+
+ expect_rx_by = now + timo;
+ WRITE_ONCE(call->expect_rx_by, expect_rx_by);
+ rxrpc_reduce_call_timer(call, expect_rx_by, now,
+ rxrpc_timer_set_for_normal);
+ }
+
+ switch (sp->hdr.type) {
+ case RXRPC_PACKET_TYPE_DATA:
+ rxrpc_input_data(call, skb, skew);
+ break;
+
+ case RXRPC_PACKET_TYPE_ACK:
+ rxrpc_input_ack(call, skb, skew);
+ break;
+
+ case RXRPC_PACKET_TYPE_BUSY:
+ _proto("Rx BUSY %%%u", sp->hdr.serial);
+
+ /* Just ignore BUSY packets from the server; the retry and
+ * lifespan timers will take care of business. BUSY packets
+ * from the client don't make sense.
+ */
+ break;
+
+ case RXRPC_PACKET_TYPE_ABORT:
+ rxrpc_input_abort(call, skb);
+ break;
+
+ case RXRPC_PACKET_TYPE_ACKALL:
+ rxrpc_input_ackall(call, skb);
+ break;
+
+ default:
+ break;
+ }
+
+ _leave("");
+}
+
+/*
+ * Handle a new service call on a channel implicitly completing the preceding
+ * call on that channel. This does not apply to client conns.
+ *
+ * TODO: If callNumber > call_id + 1, renegotiate security.
+ */
+static void rxrpc_input_implicit_end_call(struct rxrpc_sock *rx,
+ struct rxrpc_connection *conn,
+ struct rxrpc_call *call)
+{
+ switch (READ_ONCE(call->state)) {
+ case RXRPC_CALL_SERVER_AWAIT_ACK:
+ rxrpc_call_completed(call);
+ /* Fall through */
+ case RXRPC_CALL_COMPLETE:
+ break;
+ default:
+ if (rxrpc_abort_call("IMP", call, 0, RX_CALL_DEAD, -ESHUTDOWN)) {
+ set_bit(RXRPC_CALL_EV_ABORT, &call->events);
+ rxrpc_queue_call(call);
+ }
+ trace_rxrpc_improper_term(call);
+ break;
+ }
+
+ spin_lock(&rx->incoming_lock);
+ __rxrpc_disconnect_call(conn, call);
+ spin_unlock(&rx->incoming_lock);
+ rxrpc_notify_socket(call);
+}
+
+/*
+ * post connection-level events to the connection
+ * - this includes challenges, responses, some aborts and call terminal packet
+ * retransmission.
+ */
+static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
+ struct sk_buff *skb)
+{
+ _enter("%p,%p", conn, skb);
+
+ skb_queue_tail(&conn->rx_queue, skb);
+ rxrpc_queue_conn(conn);
+}
+
+/*
+ * post endpoint-level events to the local endpoint
+ * - this includes debug and version messages
+ */
+static void rxrpc_post_packet_to_local(struct rxrpc_local *local,
+ struct sk_buff *skb)
+{
+ _enter("%p,%p", local, skb);
+
+ if (rxrpc_get_local_maybe(local)) {
+ skb_queue_tail(&local->event_queue, skb);
+ rxrpc_queue_local(local);
+ } else {
+ rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
+ }
+}
+
+/*
+ * put a packet up for transport-level abort
+ */
+static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
+{
+ CHECK_SLAB_OKAY(&local->usage);
+
+ if (rxrpc_get_local_maybe(local)) {
+ skb_queue_tail(&local->reject_queue, skb);
+ rxrpc_queue_local(local);
+ } else {
+ rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
+ }
+}
+
+/*
+ * Extract the wire header from a packet and translate the byte order.
+ */
+static noinline
+int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb)
+{
+ struct rxrpc_wire_header whdr;
+
+ /* dig out the RxRPC connection details */
+ if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0) {
+ trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
+ tracepoint_string("bad_hdr"));
+ return -EBADMSG;
+ }
+
+ memset(sp, 0, sizeof(*sp));
+ sp->hdr.epoch = ntohl(whdr.epoch);
+ sp->hdr.cid = ntohl(whdr.cid);
+ sp->hdr.callNumber = ntohl(whdr.callNumber);
+ sp->hdr.seq = ntohl(whdr.seq);
+ sp->hdr.serial = ntohl(whdr.serial);
+ sp->hdr.flags = whdr.flags;
+ sp->hdr.type = whdr.type;
+ sp->hdr.userStatus = whdr.userStatus;
+ sp->hdr.securityIndex = whdr.securityIndex;
+ sp->hdr._rsvd = ntohs(whdr._rsvd);
+ sp->hdr.serviceId = ntohs(whdr.serviceId);
+ return 0;
+}
+
+/*
+ * handle data received on the local endpoint
+ * - may be called in interrupt context
+ *
+ * [!] Note that as this is called from the encap_rcv hook, the socket is not
+ * held locked by the caller and nothing prevents sk_user_data on the UDP from
+ * being cleared in the middle of processing this function.
+ *
+ * Called with the RCU read lock held from the IP layer via UDP.
+ */
+int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb)
+{
+ struct rxrpc_local *local = rcu_dereference_sk_user_data(udp_sk);
+ struct rxrpc_connection *conn;
+ struct rxrpc_channel *chan;
+ struct rxrpc_call *call = NULL;
+ struct rxrpc_skb_priv *sp;
+ struct rxrpc_peer *peer = NULL;
+ struct rxrpc_sock *rx = NULL;
+ unsigned int channel;
+ int skew = 0;
+
+ _enter("%p", udp_sk);
+
+ if (unlikely(!local)) {
+ kfree_skb(skb);
+ return 0;
+ }
+ if (skb->tstamp == 0)
+ skb->tstamp = ktime_get_real();
+
+ rxrpc_new_skb(skb, rxrpc_skb_rx_received);
+
+ skb_pull(skb, sizeof(struct udphdr));
+
+ /* The UDP protocol already released all skb resources;
+ * we are free to add our own data there.
+ */
+ sp = rxrpc_skb(skb);
+
+ /* dig out the RxRPC connection details */
+ if (rxrpc_extract_header(sp, skb) < 0)
+ goto bad_message;
+
+ if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
+ static int lose;
+ if ((lose++ & 7) == 7) {
+ trace_rxrpc_rx_lose(sp);
+ rxrpc_free_skb(skb, rxrpc_skb_rx_lost);
+ return 0;
+ }
+ }
+
+ if (skb->tstamp == 0)
+ skb->tstamp = ktime_get_real();
+ trace_rxrpc_rx_packet(sp);
+
+ switch (sp->hdr.type) {
+ case RXRPC_PACKET_TYPE_VERSION:
+ if (rxrpc_to_client(sp))
+ goto discard;
+ rxrpc_post_packet_to_local(local, skb);
+ goto out;
+
+ case RXRPC_PACKET_TYPE_BUSY:
+ if (rxrpc_to_server(sp))
+ goto discard;
+ /* Fall through */
+ case RXRPC_PACKET_TYPE_ACK:
+ case RXRPC_PACKET_TYPE_ACKALL:
+ if (sp->hdr.callNumber == 0)
+ goto bad_message;
+ /* Fall through */
+ case RXRPC_PACKET_TYPE_ABORT:
+ break;
+
+ case RXRPC_PACKET_TYPE_DATA:
+ if (sp->hdr.callNumber == 0 ||
+ sp->hdr.seq == 0)
+ goto bad_message;
+ if (sp->hdr.flags & RXRPC_JUMBO_PACKET &&
+ !rxrpc_validate_jumbo(skb))
+ goto bad_message;
+ break;
+
+ case RXRPC_PACKET_TYPE_CHALLENGE:
+ if (rxrpc_to_server(sp))
+ goto discard;
+ break;
+ case RXRPC_PACKET_TYPE_RESPONSE:
+ if (rxrpc_to_client(sp))
+ goto discard;
+ break;
+
+ /* Packet types 9-11 should just be ignored. */
+ case RXRPC_PACKET_TYPE_PARAMS:
+ case RXRPC_PACKET_TYPE_10:
+ case RXRPC_PACKET_TYPE_11:
+ goto discard;
+
+ default:
+ _proto("Rx Bad Packet Type %u", sp->hdr.type);
+ goto bad_message;
+ }
+
+ if (sp->hdr.serviceId == 0)
+ goto bad_message;
+
+ if (rxrpc_to_server(sp)) {
+ /* Weed out packets to services we're not offering. Packets
+ * that would begin a call are explicitly rejected and the rest
+ * are just discarded.
+ */
+ rx = rcu_dereference(local->service);
+ if (!rx || (sp->hdr.serviceId != rx->srx.srx_service &&
+ sp->hdr.serviceId != rx->second_service)) {
+ if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
+ sp->hdr.seq == 1)
+ goto unsupported_service;
+ goto discard;
+ }
+ }
+
+ conn = rxrpc_find_connection_rcu(local, skb, &peer);
+ if (conn) {
+ if (sp->hdr.securityIndex != conn->security_ix)
+ goto wrong_security;
+
+ if (sp->hdr.serviceId != conn->service_id) {
+ int old_id;
+
+ if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags))
+ goto reupgrade;
+ old_id = cmpxchg(&conn->service_id, conn->params.service_id,
+ sp->hdr.serviceId);
+
+ if (old_id != conn->params.service_id &&
+ old_id != sp->hdr.serviceId)
+ goto reupgrade;
+ }
+
+ if (sp->hdr.callNumber == 0) {
+ /* Connection-level packet */
+ _debug("CONN %p {%d}", conn, conn->debug_id);
+ rxrpc_post_packet_to_conn(conn, skb);
+ goto out;
+ }
+
+ /* Note the serial number skew here */
+ skew = (int)sp->hdr.serial - (int)conn->hi_serial;
+ if (skew >= 0) {
+ if (skew > 0)
+ conn->hi_serial = sp->hdr.serial;
+ } else {
+ skew = -skew;
+ skew = min(skew, 65535);
+ }
+
+ /* Call-bound packets are routed by connection channel. */
+ channel = sp->hdr.cid & RXRPC_CHANNELMASK;
+ chan = &conn->channels[channel];
+
+ /* Ignore really old calls */
+ if (sp->hdr.callNumber < chan->last_call)
+ goto discard;
+
+ if (sp->hdr.callNumber == chan->last_call) {
+ if (chan->call ||
+ sp->hdr.type == RXRPC_PACKET_TYPE_ABORT)
+ goto discard;
+
+ /* For the previous service call, if completed
+ * successfully, we discard all further packets.
+ */
+ if (rxrpc_conn_is_service(conn) &&
+ chan->last_type == RXRPC_PACKET_TYPE_ACK)
+ goto discard;
+
+ /* But otherwise we need to retransmit the final packet
+ * from data cached in the connection record.
+ */
+ if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA)
+ trace_rxrpc_rx_data(chan->call_debug_id,
+ sp->hdr.seq,
+ sp->hdr.serial,
+ sp->hdr.flags, 0);
+ rxrpc_post_packet_to_conn(conn, skb);
+ goto out;
+ }
+
+ call = rcu_dereference(chan->call);
+
+ if (sp->hdr.callNumber > chan->call_id) {
+ if (rxrpc_to_client(sp))
+ goto reject_packet;
+ if (call)
+ rxrpc_input_implicit_end_call(rx, conn, call);
+ call = NULL;
+ }
+
+ if (call) {
+ if (sp->hdr.serviceId != call->service_id)
+ call->service_id = sp->hdr.serviceId;
+ if ((int)sp->hdr.serial - (int)call->rx_serial > 0)
+ call->rx_serial = sp->hdr.serial;
+ if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags))
+ set_bit(RXRPC_CALL_RX_HEARD, &call->flags);
+ }
+ }
+
+ if (!call || atomic_read(&call->usage) == 0) {
+ if (rxrpc_to_client(sp) ||
+ sp->hdr.type != RXRPC_PACKET_TYPE_DATA)
+ goto bad_message;
+ if (sp->hdr.seq != 1)
+ goto discard;
+ call = rxrpc_new_incoming_call(local, rx, skb);
+ if (!call)
+ goto reject_packet;
+ rxrpc_send_ping(call, skb, skew);
+ mutex_unlock(&call->user_mutex);
+ }
+
+ rxrpc_input_call_packet(call, skb, skew);
+ goto discard;
+
+discard:
+ rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
+out:
+ trace_rxrpc_rx_done(0, 0);
+ return 0;
+
+wrong_security:
+ trace_rxrpc_abort(0, "SEC", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
+ RXKADINCONSISTENCY, EBADMSG);
+ skb->priority = RXKADINCONSISTENCY;
+ goto post_abort;
+
+unsupported_service:
+ trace_rxrpc_abort(0, "INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
+ RX_INVALID_OPERATION, EOPNOTSUPP);
+ skb->priority = RX_INVALID_OPERATION;
+ goto post_abort;
+
+reupgrade:
+ trace_rxrpc_abort(0, "UPG", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
+ RX_PROTOCOL_ERROR, EBADMSG);
+ goto protocol_error;
+
+bad_message:
+ trace_rxrpc_abort(0, "BAD", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
+ RX_PROTOCOL_ERROR, EBADMSG);
+protocol_error:
+ skb->priority = RX_PROTOCOL_ERROR;
+post_abort:
+ skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
+reject_packet:
+ trace_rxrpc_rx_done(skb->mark, skb->priority);
+ rxrpc_reject_packet(local, skb);
+ _leave(" [badmsg]");
+ return 0;
+}