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, 305 insertions, 0 deletions

diff --git a/net/rxrpc/peer_object.c b/net/rxrpc/peer_object.c
new file mode 100644
index 000000000000..0b54cda3d8e5
--- /dev/null
+++ b/net/rxrpc/peer_object.c
@@ -0,0 +1,305 @@
+/* RxRPC remote transport endpoint management
+ *
+ * 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/udp.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/icmp.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <net/ip.h>
+#include <net/route.h>
+#include "ar-internal.h"
+
+static LIST_HEAD(rxrpc_peers);
+static DEFINE_RWLOCK(rxrpc_peer_lock);
+static DECLARE_WAIT_QUEUE_HEAD(rxrpc_peer_wq);
+
+static void rxrpc_destroy_peer(struct work_struct *work);
+
+/*
+ * assess the MTU size for the network interface through which this peer is
+ * reached
+ */
+static void rxrpc_assess_MTU_size(struct rxrpc_peer *peer)
+{
+	struct rtable *rt;
+	struct flowi4 fl4;
+
+	peer->if_mtu = 1500;
+
+	rt = ip_route_output_ports(&init_net, &fl4, NULL,
+				   peer->srx.transport.sin.sin_addr.s_addr, 0,
+				   htons(7000), htons(7001),
+				   IPPROTO_UDP, 0, 0);
+	if (IS_ERR(rt)) {
+		_leave(" [route err %ld]", PTR_ERR(rt));
+		return;
+	}
+
+	peer->if_mtu = dst_mtu(&rt->dst);
+	dst_release(&rt->dst);
+
+	_leave(" [if_mtu %u]", peer->if_mtu);
+}
+
+/*
+ * allocate a new peer
+ */
+static struct rxrpc_peer *rxrpc_alloc_peer(struct sockaddr_rxrpc *srx,
+					   gfp_t gfp)
+{
+	struct rxrpc_peer *peer;
+
+	_enter("");
+
+	peer = kzalloc(sizeof(struct rxrpc_peer), gfp);
+	if (peer) {
+		INIT_WORK(&peer->destroyer, &rxrpc_destroy_peer);
+		INIT_LIST_HEAD(&peer->link);
+		INIT_LIST_HEAD(&peer->error_targets);
+		spin_lock_init(&peer->lock);
+		atomic_set(&peer->usage, 1);
+		peer->debug_id = atomic_inc_return(&rxrpc_debug_id);
+		memcpy(&peer->srx, srx, sizeof(*srx));
+
+		rxrpc_assess_MTU_size(peer);
+		peer->mtu = peer->if_mtu;
+
+		if (srx->transport.family == AF_INET) {
+			peer->hdrsize = sizeof(struct iphdr);
+			switch (srx->transport_type) {
+			case SOCK_DGRAM:
+				peer->hdrsize += sizeof(struct udphdr);
+				break;
+			default:
+				BUG();
+				break;
+			}
+		} else {
+			BUG();
+		}
+
+		peer->hdrsize += sizeof(struct rxrpc_wire_header);
+		peer->maxdata = peer->mtu - peer->hdrsize;
+	}
+
+	_leave(" = %p", peer);
+	return peer;
+}
+
+/*
+ * obtain a remote transport endpoint for the specified address
+ */
+struct rxrpc_peer *rxrpc_get_peer(struct sockaddr_rxrpc *srx, gfp_t gfp)
+{
+	struct rxrpc_peer *peer, *candidate;
+	const char *new = "old";
+	int usage;
+
+	_enter("{%d,%d,%pI4+%hu}",
+	       srx->transport_type,
+	       srx->transport_len,
+	       &srx->transport.sin.sin_addr,
+	       ntohs(srx->transport.sin.sin_port));
+
+	/* search the peer list first */
+	read_lock_bh(&rxrpc_peer_lock);
+	list_for_each_entry(peer, &rxrpc_peers, link) {
+		_debug("check PEER %d { u=%d t=%d l=%d }",
+		       peer->debug_id,
+		       atomic_read(&peer->usage),
+		       peer->srx.transport_type,
+		       peer->srx.transport_len);
+
+		if (atomic_read(&peer->usage) > 0 &&
+		    peer->srx.transport_type == srx->transport_type &&
+		    peer->srx.transport_len == srx->transport_len &&
+		    memcmp(&peer->srx.transport,
+			   &srx->transport,
+			   srx->transport_len) == 0)
+			goto found_extant_peer;
+	}
+	read_unlock_bh(&rxrpc_peer_lock);
+
+	/* not yet present - create a candidate for a new record and then
+	 * redo the search */
+	candidate = rxrpc_alloc_peer(srx, gfp);
+	if (!candidate) {
+		_leave(" = -ENOMEM");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	write_lock_bh(&rxrpc_peer_lock);
+
+	list_for_each_entry(peer, &rxrpc_peers, link) {
+		if (atomic_read(&peer->usage) > 0 &&
+		    peer->srx.transport_type == srx->transport_type &&
+		    peer->srx.transport_len == srx->transport_len &&
+		    memcmp(&peer->srx.transport,
+			   &srx->transport,
+			   srx->transport_len) == 0)
+			goto found_extant_second;
+	}
+
+	/* we can now add the new candidate to the list */
+	peer = candidate;
+	candidate = NULL;
+	usage = atomic_read(&peer->usage);
+
+	list_add_tail(&peer->link, &rxrpc_peers);
+	write_unlock_bh(&rxrpc_peer_lock);
+	new = "new";
+
+success:
+	_net("PEER %s %d {%d,%u,%pI4+%hu}",
+	     new,
+	     peer->debug_id,
+	     peer->srx.transport_type,
+	     peer->srx.transport.family,
+	     &peer->srx.transport.sin.sin_addr,
+	     ntohs(peer->srx.transport.sin.sin_port));
+
+	_leave(" = %p {u=%d}", peer, usage);
+	return peer;
+
+	/* we found the peer in the list immediately */
+found_extant_peer:
+	usage = atomic_inc_return(&peer->usage);
+	read_unlock_bh(&rxrpc_peer_lock);
+	goto success;
+
+	/* we found the peer on the second time through the list */
+found_extant_second:
+	usage = atomic_inc_return(&peer->usage);
+	write_unlock_bh(&rxrpc_peer_lock);
+	kfree(candidate);
+	goto success;
+}
+
+/*
+ * find the peer associated with a packet
+ */
+struct rxrpc_peer *rxrpc_find_peer(struct rxrpc_local *local,
+				   __be32 addr, __be16 port)
+{
+	struct rxrpc_peer *peer;
+
+	_enter("");
+
+	/* search the peer list */
+	read_lock_bh(&rxrpc_peer_lock);
+
+	if (local->srx.transport.family == AF_INET &&
+	    local->srx.transport_type == SOCK_DGRAM
+	    ) {
+		list_for_each_entry(peer, &rxrpc_peers, link) {
+			if (atomic_read(&peer->usage) > 0 &&
+			    peer->srx.transport_type == SOCK_DGRAM &&
+			    peer->srx.transport.family == AF_INET &&
+			    peer->srx.transport.sin.sin_port == port &&
+			    peer->srx.transport.sin.sin_addr.s_addr == addr)
+				goto found_UDP_peer;
+		}
+
+		goto new_UDP_peer;
+	}
+
+	read_unlock_bh(&rxrpc_peer_lock);
+	_leave(" = -EAFNOSUPPORT");
+	return ERR_PTR(-EAFNOSUPPORT);
+
+found_UDP_peer:
+	_net("Rx UDP DGRAM from peer %d", peer->debug_id);
+	atomic_inc(&peer->usage);
+	read_unlock_bh(&rxrpc_peer_lock);
+	_leave(" = %p", peer);
+	return peer;
+
+new_UDP_peer:
+	_net("Rx UDP DGRAM from NEW peer");
+	read_unlock_bh(&rxrpc_peer_lock);
+	_leave(" = -EBUSY [new]");
+	return ERR_PTR(-EBUSY);
+}
+
+/*
+ * release a remote transport endpoint
+ */
+void rxrpc_put_peer(struct rxrpc_peer *peer)
+{
+	_enter("%p{u=%d}", peer, atomic_read(&peer->usage));
+
+	ASSERTCMP(atomic_read(&peer->usage), >, 0);
+
+	if (likely(!atomic_dec_and_test(&peer->usage))) {
+		_leave(" [in use]");
+		return;
+	}
+
+	rxrpc_queue_work(&peer->destroyer);
+	_leave("");
+}
+
+/*
+ * destroy a remote transport endpoint
+ */
+static void rxrpc_destroy_peer(struct work_struct *work)
+{
+	struct rxrpc_peer *peer =
+		container_of(work, struct rxrpc_peer, destroyer);
+
+	_enter("%p{%d}", peer, atomic_read(&peer->usage));
+
+	write_lock_bh(&rxrpc_peer_lock);
+	list_del(&peer->link);
+	write_unlock_bh(&rxrpc_peer_lock);
+
+	_net("DESTROY PEER %d", peer->debug_id);
+	kfree(peer);
+
+	if (list_empty(&rxrpc_peers))
+		wake_up_all(&rxrpc_peer_wq);
+	_leave("");
+}
+
+/*
+ * preemptively destroy all the peer records from a transport endpoint rather
+ * than waiting for them to time out
+ */
+void __exit rxrpc_destroy_all_peers(void)
+{
+	DECLARE_WAITQUEUE(myself,current);
+
+	_enter("");
+
+	/* we simply have to wait for them to go away */
+	if (!list_empty(&rxrpc_peers)) {
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		add_wait_queue(&rxrpc_peer_wq, &myself);
+
+		while (!list_empty(&rxrpc_peers)) {
+			schedule();
+			set_current_state(TASK_UNINTERRUPTIBLE);
+		}
+
+		remove_wait_queue(&rxrpc_peer_wq, &myself);
+		set_current_state(TASK_RUNNING);
+	}
+
+	_leave("");
+}