rxrpc: Rename files matching ar-*.c to git rid of the "ar-" prefix

Rename files matching net/rxrpc/ar-*.c to get rid of the "ar-" prefix.
This will aid splitting those files by making easier to come up with new
names.

Note that the not all files are simply renamed from ar-X.c to X.c.  The
following exceptions are made:

 (*) ar-call.c -> call_object.c
     ar-ack.c -> call_event.c

     call_object.c is going to contain the core of the call object
     handling.  Call event handling is all going to be in call_event.c.

 (*) ar-accept.c -> call_accept.c

     Incoming call handling is going to be here.

 (*) ar-connection.c -> conn_object.c
     ar-connevent.c -> conn_event.c

     The former file is going to have the basic connection object handling,
     but there will likely be some differentiation between client
     connections and service connections in additional files later.  The
     latter file will have all the connection-level event handling.

 (*) ar-local.c -> local_object.c

     This will have the local endpoint object handling code.  The local
     endpoint event handling code will later be split out into
     local_event.c.

 (*) ar-peer.c -> peer_object.c

     This will have the peer endpoint object handling code.  Peer event
     handling code will be placed in peer_event.c (for the moment, there is
     none).

 (*) ar-error.c -> peer_event.c

     This will become the peer event handling code, though for the moment
     it's actually driven from the local endpoint's perspective.

Note that I haven't renamed ar-transport.c to transport_object.c as the
intention is to delete it when the rxrpc_transport struct is excised.

The only file that actually has its contents changed is net/rxrpc/Makefile.

net/rxrpc/ar-internal.h will need its section marker comments updating, but
I'll do that in a separate patch to make it easier for git to follow the
history across the rename.  I may also want to rename ar-internal.h at some
point - but that would mean updating all the #includes and I'd rather do
that in a separate step.

Signed-off-by: David Howells <dhowells@redhat.com.

1 files changed, 800 insertions, 0 deletions

diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
new file mode 100644
index 000000000000..e0815a033999
--- /dev/null
+++ b/net/rxrpc/input.c
@@ -0,0 +1,800 @@
+/* RxRPC packet 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.
+ */
+
+#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"
+
+/*
+ * queue a packet for recvmsg to pass to userspace
+ * - the caller must hold a lock on call->lock
+ * - must not be called with interrupts disabled (sk_filter() disables BH's)
+ * - eats the packet whether successful or not
+ * - there must be just one reference to the packet, which the caller passes to
+ *   this function
+ */
+int rxrpc_queue_rcv_skb(struct rxrpc_call *call, struct sk_buff *skb,
+			bool force, bool terminal)
+{
+	struct rxrpc_skb_priv *sp;
+	struct rxrpc_sock *rx = call->socket;
+	struct sock *sk;
+	int ret;
+
+	_enter(",,%d,%d", force, terminal);
+
+	ASSERT(!irqs_disabled());
+
+	sp = rxrpc_skb(skb);
+	ASSERTCMP(sp->call, ==, call);
+
+	/* if we've already posted the terminal message for a call, then we
+	 * don't post any more */
+	if (test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags)) {
+		_debug("already terminated");
+		ASSERTCMP(call->state, >=, RXRPC_CALL_COMPLETE);
+		skb->destructor = NULL;
+		sp->call = NULL;
+		rxrpc_put_call(call);
+		rxrpc_free_skb(skb);
+		return 0;
+	}
+
+	sk = &rx->sk;
+
+	if (!force) {
+		/* cast skb->rcvbuf to unsigned...  It's pointless, but
+		 * reduces number of warnings when compiling with -W
+		 * --ANK */
+//		ret = -ENOBUFS;
+//		if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
+//		    (unsigned int) sk->sk_rcvbuf)
+//			goto out;
+
+		ret = sk_filter(sk, skb);
+		if (ret < 0)
+			goto out;
+	}
+
+	spin_lock_bh(&sk->sk_receive_queue.lock);
+	if (!test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags) &&
+	    !test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
+	    call->socket->sk.sk_state != RXRPC_CLOSE) {
+		skb->destructor = rxrpc_packet_destructor;
+		skb->dev = NULL;
+		skb->sk = sk;
+		atomic_add(skb->truesize, &sk->sk_rmem_alloc);
+
+		if (terminal) {
+			_debug("<<<< TERMINAL MESSAGE >>>>");
+			set_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags);
+		}
+
+		/* allow interception by a kernel service */
+		if (rx->interceptor) {
+			rx->interceptor(sk, call->user_call_ID, skb);
+			spin_unlock_bh(&sk->sk_receive_queue.lock);
+		} else {
+			_net("post skb %p", skb);
+			__skb_queue_tail(&sk->sk_receive_queue, skb);
+			spin_unlock_bh(&sk->sk_receive_queue.lock);
+
+			if (!sock_flag(sk, SOCK_DEAD))
+				sk->sk_data_ready(sk);
+		}
+		skb = NULL;
+	} else {
+		spin_unlock_bh(&sk->sk_receive_queue.lock);
+	}
+	ret = 0;
+
+out:
+	/* release the socket buffer */
+	if (skb) {
+		skb->destructor = NULL;
+		sp->call = NULL;
+		rxrpc_put_call(call);
+		rxrpc_free_skb(skb);
+	}
+
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * process a DATA packet, posting the packet to the appropriate queue
+ * - eats the packet if successful
+ */
+static int rxrpc_fast_process_data(struct rxrpc_call *call,
+				   struct sk_buff *skb, u32 seq)
+{
+	struct rxrpc_skb_priv *sp;
+	bool terminal;
+	int ret, ackbit, ack;
+
+	_enter("{%u,%u},,{%u}", call->rx_data_post, call->rx_first_oos, seq);
+
+	sp = rxrpc_skb(skb);
+	ASSERTCMP(sp->call, ==, NULL);
+
+	spin_lock(&call->lock);
+
+	if (call->state > RXRPC_CALL_COMPLETE)
+		goto discard;
+
+	ASSERTCMP(call->rx_data_expect, >=, call->rx_data_post);
+	ASSERTCMP(call->rx_data_post, >=, call->rx_data_recv);
+	ASSERTCMP(call->rx_data_recv, >=, call->rx_data_eaten);
+
+	if (seq < call->rx_data_post) {
+		_debug("dup #%u [-%u]", seq, call->rx_data_post);
+		ack = RXRPC_ACK_DUPLICATE;
+		ret = -ENOBUFS;
+		goto discard_and_ack;
+	}
+
+	/* we may already have the packet in the out of sequence queue */
+	ackbit = seq - (call->rx_data_eaten + 1);
+	ASSERTCMP(ackbit, >=, 0);
+	if (__test_and_set_bit(ackbit, call->ackr_window)) {
+		_debug("dup oos #%u [%u,%u]",
+		       seq, call->rx_data_eaten, call->rx_data_post);
+		ack = RXRPC_ACK_DUPLICATE;
+		goto discard_and_ack;
+	}
+
+	if (seq >= call->ackr_win_top) {
+		_debug("exceed #%u [%u]", seq, call->ackr_win_top);
+		__clear_bit(ackbit, call->ackr_window);
+		ack = RXRPC_ACK_EXCEEDS_WINDOW;
+		goto discard_and_ack;
+	}
+
+	if (seq == call->rx_data_expect) {
+		clear_bit(RXRPC_CALL_EXPECT_OOS, &call->flags);
+		call->rx_data_expect++;
+	} else if (seq > call->rx_data_expect) {
+		_debug("oos #%u [%u]", seq, call->rx_data_expect);
+		call->rx_data_expect = seq + 1;
+		if (test_and_set_bit(RXRPC_CALL_EXPECT_OOS, &call->flags)) {
+			ack = RXRPC_ACK_OUT_OF_SEQUENCE;
+			goto enqueue_and_ack;
+		}
+		goto enqueue_packet;
+	}
+
+	if (seq != call->rx_data_post) {
+		_debug("ahead #%u [%u]", seq, call->rx_data_post);
+		goto enqueue_packet;
+	}
+
+	if (test_bit(RXRPC_CALL_RCVD_LAST, &call->flags))
+		goto protocol_error;
+
+	/* if the packet need security things doing to it, then it goes down
+	 * the slow path */
+	if (call->conn->security_ix)
+		goto enqueue_packet;
+
+	sp->call = call;
+	rxrpc_get_call(call);
+	terminal = ((sp->hdr.flags & RXRPC_LAST_PACKET) &&
+		    !(sp->hdr.flags & RXRPC_CLIENT_INITIATED));
+	ret = rxrpc_queue_rcv_skb(call, skb, false, terminal);
+	if (ret < 0) {
+		if (ret == -ENOMEM || ret == -ENOBUFS) {
+			__clear_bit(ackbit, call->ackr_window);
+			ack = RXRPC_ACK_NOSPACE;
+			goto discard_and_ack;
+		}
+		goto out;
+	}
+
+	skb = NULL;
+
+	_debug("post #%u", seq);
+	ASSERTCMP(call->rx_data_post, ==, seq);
+	call->rx_data_post++;
+
+	if (sp->hdr.flags & RXRPC_LAST_PACKET)
+		set_bit(RXRPC_CALL_RCVD_LAST, &call->flags);
+
+	/* if we've reached an out of sequence packet then we need to drain
+	 * that queue into the socket Rx queue now */
+	if (call->rx_data_post == call->rx_first_oos) {
+		_debug("drain rx oos now");
+		read_lock(&call->state_lock);
+		if (call->state < RXRPC_CALL_COMPLETE &&
+		    !test_and_set_bit(RXRPC_CALL_EV_DRAIN_RX_OOS, &call->events))
+			rxrpc_queue_call(call);
+		read_unlock(&call->state_lock);
+	}
+
+	spin_unlock(&call->lock);
+	atomic_inc(&call->ackr_not_idle);
+	rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, sp->hdr.serial, false);
+	_leave(" = 0 [posted]");
+	return 0;
+
+protocol_error:
+	ret = -EBADMSG;
+out:
+	spin_unlock(&call->lock);
+	_leave(" = %d", ret);
+	return ret;
+
+discard_and_ack:
+	_debug("discard and ACK packet %p", skb);
+	__rxrpc_propose_ACK(call, ack, sp->hdr.serial, true);
+discard:
+	spin_unlock(&call->lock);
+	rxrpc_free_skb(skb);
+	_leave(" = 0 [discarded]");
+	return 0;
+
+enqueue_and_ack:
+	__rxrpc_propose_ACK(call, ack, sp->hdr.serial, true);
+enqueue_packet:
+	_net("defer skb %p", skb);
+	spin_unlock(&call->lock);
+	skb_queue_tail(&call->rx_queue, skb);
+	atomic_inc(&call->ackr_not_idle);
+	read_lock(&call->state_lock);
+	if (call->state < RXRPC_CALL_DEAD)
+		rxrpc_queue_call(call);
+	read_unlock(&call->state_lock);
+	_leave(" = 0 [queued]");
+	return 0;
+}
+
+/*
+ * assume an implicit ACKALL of the transmission phase of a client socket upon
+ * reception of the first reply packet
+ */
+static void rxrpc_assume_implicit_ackall(struct rxrpc_call *call, u32 serial)
+{
+	write_lock_bh(&call->state_lock);
+
+	switch (call->state) {
+	case RXRPC_CALL_CLIENT_AWAIT_REPLY:
+		call->state = RXRPC_CALL_CLIENT_RECV_REPLY;
+		call->acks_latest = serial;
+
+		_debug("implicit ACKALL %%%u", call->acks_latest);
+		set_bit(RXRPC_CALL_EV_RCVD_ACKALL, &call->events);
+		write_unlock_bh(&call->state_lock);
+
+		if (try_to_del_timer_sync(&call->resend_timer) >= 0) {
+			clear_bit(RXRPC_CALL_EV_RESEND_TIMER, &call->events);
+			clear_bit(RXRPC_CALL_EV_RESEND, &call->events);
+			clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
+		}
+		break;
+
+	default:
+		write_unlock_bh(&call->state_lock);
+		break;
+	}
+}
+
+/*
+ * post an incoming packet to the nominated call to deal with
+ * - must get rid of the sk_buff, either by freeing it or by queuing it
+ */
+void rxrpc_fast_process_packet(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	__be32 wtmp;
+	u32 hi_serial, abort_code;
+
+	_enter("%p,%p", call, skb);
+
+	ASSERT(!irqs_disabled());
+
+#if 0 // INJECT RX ERROR
+	if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA) {
+		static int skip = 0;
+		if (++skip == 3) {
+			printk("DROPPED 3RD PACKET!!!!!!!!!!!!!\n");
+			skip = 0;
+			goto free_packet;
+		}
+	}
+#endif
+
+	/* track the latest serial number on this connection for ACK packet
+	 * information */
+	hi_serial = atomic_read(&call->conn->hi_serial);
+	while (sp->hdr.serial > hi_serial)
+		hi_serial = atomic_cmpxchg(&call->conn->hi_serial, hi_serial,
+					   sp->hdr.serial);
+
+	/* request ACK generation for any ACK or DATA packet that requests
+	 * it */
+	if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
+		_proto("ACK Requested on %%%u", sp->hdr.serial);
+		rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED, sp->hdr.serial, false);
+	}
+
+	switch (sp->hdr.type) {
+	case RXRPC_PACKET_TYPE_ABORT:
+		_debug("abort");
+
+		if (skb_copy_bits(skb, 0, &wtmp, sizeof(wtmp)) < 0)
+			goto protocol_error;
+
+		abort_code = ntohl(wtmp);
+		_proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code);
+
+		write_lock_bh(&call->state_lock);
+		if (call->state < RXRPC_CALL_COMPLETE) {
+			call->state = RXRPC_CALL_REMOTELY_ABORTED;
+			call->remote_abort = abort_code;
+			set_bit(RXRPC_CALL_EV_RCVD_ABORT, &call->events);
+			rxrpc_queue_call(call);
+		}
+		goto free_packet_unlock;
+
+	case RXRPC_PACKET_TYPE_BUSY:
+		_proto("Rx BUSY %%%u", sp->hdr.serial);
+
+		if (call->conn->out_clientflag)
+			goto protocol_error;
+
+		write_lock_bh(&call->state_lock);
+		switch (call->state) {
+		case RXRPC_CALL_CLIENT_SEND_REQUEST:
+			call->state = RXRPC_CALL_SERVER_BUSY;
+			set_bit(RXRPC_CALL_EV_RCVD_BUSY, &call->events);
+			rxrpc_queue_call(call);
+		case RXRPC_CALL_SERVER_BUSY:
+			goto free_packet_unlock;
+		default:
+			goto protocol_error_locked;
+		}
+
+	default:
+		_proto("Rx %s %%%u", rxrpc_pkts[sp->hdr.type], sp->hdr.serial);
+		goto protocol_error;
+
+	case RXRPC_PACKET_TYPE_DATA:
+		_proto("Rx DATA %%%u { #%u }", sp->hdr.serial, sp->hdr.seq);
+
+		if (sp->hdr.seq == 0)
+			goto protocol_error;
+
+		call->ackr_prev_seq = sp->hdr.seq;
+
+		/* received data implicitly ACKs all of the request packets we
+		 * sent when we're acting as a client */
+		if (call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY)
+			rxrpc_assume_implicit_ackall(call, sp->hdr.serial);
+
+		switch (rxrpc_fast_process_data(call, skb, sp->hdr.seq)) {
+		case 0:
+			skb = NULL;
+			goto done;
+
+		default:
+			BUG();
+
+			/* data packet received beyond the last packet */
+		case -EBADMSG:
+			goto protocol_error;
+		}
+
+	case RXRPC_PACKET_TYPE_ACKALL:
+	case RXRPC_PACKET_TYPE_ACK:
+		/* ACK processing is done in process context */
+		read_lock_bh(&call->state_lock);
+		if (call->state < RXRPC_CALL_DEAD) {
+			skb_queue_tail(&call->rx_queue, skb);
+			rxrpc_queue_call(call);
+			skb = NULL;
+		}
+		read_unlock_bh(&call->state_lock);
+		goto free_packet;
+	}
+
+protocol_error:
+	_debug("protocol error");
+	write_lock_bh(&call->state_lock);
+protocol_error_locked:
+	if (call->state <= RXRPC_CALL_COMPLETE) {
+		call->state = RXRPC_CALL_LOCALLY_ABORTED;
+		call->local_abort = RX_PROTOCOL_ERROR;
+		set_bit(RXRPC_CALL_EV_ABORT, &call->events);
+		rxrpc_queue_call(call);
+	}
+free_packet_unlock:
+	write_unlock_bh(&call->state_lock);
+free_packet:
+	rxrpc_free_skb(skb);
+done:
+	_leave("");
+}
+
+/*
+ * split up a jumbo data packet
+ */
+static void rxrpc_process_jumbo_packet(struct rxrpc_call *call,
+				       struct sk_buff *jumbo)
+{
+	struct rxrpc_jumbo_header jhdr;
+	struct rxrpc_skb_priv *sp;
+	struct sk_buff *part;
+
+	_enter(",{%u,%u}", jumbo->data_len, jumbo->len);
+
+	sp = rxrpc_skb(jumbo);
+
+	do {
+		sp->hdr.flags &= ~RXRPC_JUMBO_PACKET;
+
+		/* make a clone to represent the first subpacket in what's left
+		 * of the jumbo packet */
+		part = skb_clone(jumbo, GFP_ATOMIC);
+		if (!part) {
+			/* simply ditch the tail in the event of ENOMEM */
+			pskb_trim(jumbo, RXRPC_JUMBO_DATALEN);
+			break;
+		}
+		rxrpc_new_skb(part);
+
+		pskb_trim(part, RXRPC_JUMBO_DATALEN);
+
+		if (!pskb_pull(jumbo, RXRPC_JUMBO_DATALEN))
+			goto protocol_error;
+
+		if (skb_copy_bits(jumbo, 0, &jhdr, sizeof(jhdr)) < 0)
+			goto protocol_error;
+		if (!pskb_pull(jumbo, sizeof(jhdr)))
+			BUG();
+
+		sp->hdr.seq	+= 1;
+		sp->hdr.serial	+= 1;
+		sp->hdr.flags	= jhdr.flags;
+		sp->hdr._rsvd	= jhdr._rsvd;
+
+		_proto("Rx DATA Jumbo %%%u", sp->hdr.serial - 1);
+
+		rxrpc_fast_process_packet(call, part);
+		part = NULL;
+
+	} while (sp->hdr.flags & RXRPC_JUMBO_PACKET);
+
+	rxrpc_fast_process_packet(call, jumbo);
+	_leave("");
+	return;
+
+protocol_error:
+	_debug("protocol error");
+	rxrpc_free_skb(part);
+	rxrpc_free_skb(jumbo);
+	write_lock_bh(&call->state_lock);
+	if (call->state <= RXRPC_CALL_COMPLETE) {
+		call->state = RXRPC_CALL_LOCALLY_ABORTED;
+		call->local_abort = RX_PROTOCOL_ERROR;
+		set_bit(RXRPC_CALL_EV_ABORT, &call->events);
+		rxrpc_queue_call(call);
+	}
+	write_unlock_bh(&call->state_lock);
+	_leave("");
+}
+
+/*
+ * post an incoming packet to the appropriate call/socket to deal with
+ * - must get rid of the sk_buff, either by freeing it or by queuing it
+ */
+static void rxrpc_post_packet_to_call(struct rxrpc_call *call,
+				      struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp;
+
+	_enter("%p,%p", call, skb);
+
+	sp = rxrpc_skb(skb);
+
+	_debug("extant call [%d]", call->state);
+
+	read_lock(&call->state_lock);
+	switch (call->state) {
+	case RXRPC_CALL_LOCALLY_ABORTED:
+		if (!test_and_set_bit(RXRPC_CALL_EV_ABORT, &call->events)) {
+			rxrpc_queue_call(call);
+			goto free_unlock;
+		}
+	case RXRPC_CALL_REMOTELY_ABORTED:
+	case RXRPC_CALL_NETWORK_ERROR:
+	case RXRPC_CALL_DEAD:
+		goto dead_call;
+	case RXRPC_CALL_COMPLETE:
+	case RXRPC_CALL_CLIENT_FINAL_ACK:
+		/* complete server call */
+		if (call->conn->in_clientflag)
+			goto dead_call;
+		/* resend last packet of a completed call */
+		_debug("final ack again");
+		rxrpc_get_call(call);
+		set_bit(RXRPC_CALL_EV_ACK_FINAL, &call->events);
+		rxrpc_queue_call(call);
+		goto free_unlock;
+	default:
+		break;
+	}
+
+	read_unlock(&call->state_lock);
+	rxrpc_get_call(call);
+
+	if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
+	    sp->hdr.flags & RXRPC_JUMBO_PACKET)
+		rxrpc_process_jumbo_packet(call, skb);
+	else
+		rxrpc_fast_process_packet(call, skb);
+
+	rxrpc_put_call(call);
+	goto done;
+
+dead_call:
+	if (sp->hdr.type != RXRPC_PACKET_TYPE_ABORT) {
+		skb->priority = RX_CALL_DEAD;
+		rxrpc_reject_packet(call->conn->trans->local, skb);
+		goto unlock;
+	}
+free_unlock:
+	rxrpc_free_skb(skb);
+unlock:
+	read_unlock(&call->state_lock);
+done:
+	_leave("");
+}
+
+/*
+ * post connection-level events to the connection
+ * - this includes challenges, responses and some aborts
+ */
+static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
+				      struct sk_buff *skb)
+{
+	_enter("%p,%p", conn, skb);
+
+	atomic_inc(&conn->usage);
+	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);
+
+	atomic_inc(&local->usage);
+	skb_queue_tail(&local->event_queue, skb);
+	rxrpc_queue_work(&local->event_processor);
+}
+
+/*
+ * 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)
+		return -EBADMSG;
+	if (!pskb_pull(skb, sizeof(whdr)))
+		BUG();
+
+	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;
+}
+
+static struct rxrpc_connection *rxrpc_conn_from_local(struct rxrpc_local *local,
+					       struct sk_buff *skb,
+					       struct rxrpc_skb_priv *sp)
+{
+	struct rxrpc_peer *peer;
+	struct rxrpc_transport *trans;
+	struct rxrpc_connection *conn;
+
+	peer = rxrpc_find_peer(local, ip_hdr(skb)->saddr,
+				udp_hdr(skb)->source);
+	if (IS_ERR(peer))
+		goto cant_find_conn;
+
+	trans = rxrpc_find_transport(local, peer);
+	rxrpc_put_peer(peer);
+	if (!trans)
+		goto cant_find_conn;
+
+	conn = rxrpc_find_connection(trans, &sp->hdr);
+	rxrpc_put_transport(trans);
+	if (!conn)
+		goto cant_find_conn;
+
+	return conn;
+cant_find_conn:
+	return NULL;
+}
+
+/*
+ * handle data received on the local endpoint
+ * - may be called in interrupt context
+ */
+void rxrpc_data_ready(struct sock *sk)
+{
+	struct rxrpc_skb_priv *sp;
+	struct rxrpc_local *local;
+	struct sk_buff *skb;
+	int ret;
+
+	_enter("%p", sk);
+
+	ASSERT(!irqs_disabled());
+
+	read_lock_bh(&rxrpc_local_lock);
+	local = sk->sk_user_data;
+	if (local && atomic_read(&local->usage) > 0)
+		rxrpc_get_local(local);
+	else
+		local = NULL;
+	read_unlock_bh(&rxrpc_local_lock);
+	if (!local) {
+		_leave(" [local dead]");
+		return;
+	}
+
+	skb = skb_recv_datagram(sk, 0, 1, &ret);
+	if (!skb) {
+		rxrpc_put_local(local);
+		if (ret == -EAGAIN)
+			return;
+		_debug("UDP socket error %d", ret);
+		return;
+	}
+
+	rxrpc_new_skb(skb);
+
+	_net("recv skb %p", skb);
+
+	/* we'll probably need to checksum it (didn't call sock_recvmsg) */
+	if (skb_checksum_complete(skb)) {
+		rxrpc_free_skb(skb);
+		rxrpc_put_local(local);
+		__UDP_INC_STATS(&init_net, UDP_MIB_INERRORS, 0);
+		_leave(" [CSUM failed]");
+		return;
+	}
+
+	__UDP_INC_STATS(&init_net, UDP_MIB_INDATAGRAMS, 0);
+
+	/* The socket buffer we have is owned by UDP, with UDP's data all over
+	 * it, but we really want our own data there.
+	 */
+	skb_orphan(skb);
+	sp = rxrpc_skb(skb);
+
+	_net("Rx UDP packet from %08x:%04hu",
+	     ntohl(ip_hdr(skb)->saddr), ntohs(udp_hdr(skb)->source));
+
+	/* dig out the RxRPC connection details */
+	if (rxrpc_extract_header(sp, skb) < 0)
+		goto bad_message;
+
+	_net("Rx RxRPC %s ep=%x call=%x:%x",
+	     sp->hdr.flags & RXRPC_CLIENT_INITIATED ? "ToServer" : "ToClient",
+	     sp->hdr.epoch, sp->hdr.cid, sp->hdr.callNumber);
+
+	if (sp->hdr.type >= RXRPC_N_PACKET_TYPES ||
+	    !((RXRPC_SUPPORTED_PACKET_TYPES >> sp->hdr.type) & 1)) {
+		_proto("Rx Bad Packet Type %u", sp->hdr.type);
+		goto bad_message;
+	}
+
+	if (sp->hdr.type == RXRPC_PACKET_TYPE_VERSION) {
+		rxrpc_post_packet_to_local(local, skb);
+		goto out;
+	}
+
+	if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
+	    (sp->hdr.callNumber == 0 || sp->hdr.seq == 0))
+		goto bad_message;
+
+	if (sp->hdr.callNumber == 0) {
+		/* This is a connection-level packet. These should be
+		 * fairly rare, so the extra overhead of looking them up the
+		 * old-fashioned way doesn't really hurt */
+		struct rxrpc_connection *conn;
+
+		conn = rxrpc_conn_from_local(local, skb, sp);
+		if (!conn)
+			goto cant_route_call;
+
+		_debug("CONN %p {%d}", conn, conn->debug_id);
+		rxrpc_post_packet_to_conn(conn, skb);
+		rxrpc_put_connection(conn);
+	} else {
+		struct rxrpc_call *call;
+
+		call = rxrpc_find_call_hash(&sp->hdr, local,
+					    AF_INET, &ip_hdr(skb)->saddr);
+		if (call)
+			rxrpc_post_packet_to_call(call, skb);
+		else
+			goto cant_route_call;
+	}
+
+out:
+	rxrpc_put_local(local);
+	return;
+
+cant_route_call:
+	_debug("can't route call");
+	if (sp->hdr.flags & RXRPC_CLIENT_INITIATED &&
+	    sp->hdr.type == RXRPC_PACKET_TYPE_DATA) {
+		if (sp->hdr.seq == 1) {
+			_debug("first packet");
+			skb_queue_tail(&local->accept_queue, skb);
+			rxrpc_queue_work(&local->acceptor);
+			rxrpc_put_local(local);
+			_leave(" [incoming]");
+			return;
+		}
+		skb->priority = RX_INVALID_OPERATION;
+	} else {
+		skb->priority = RX_CALL_DEAD;
+	}
+
+	if (sp->hdr.type != RXRPC_PACKET_TYPE_ABORT) {
+		_debug("reject type %d",sp->hdr.type);
+		rxrpc_reject_packet(local, skb);
+	}
+	rxrpc_put_local(local);
+	_leave(" [no call]");
+	return;
+
+bad_message:
+	skb->priority = RX_PROTOCOL_ERROR;
+	rxrpc_reject_packet(local, skb);
+	rxrpc_put_local(local);
+	_leave(" [badmsg]");
+}