rxrpc: Split service connection code out into its own file

Split the service-specific connection code out into into its own file.  The
client-specific code has already been split out.  This will leave just the
common code in the original file.

Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/net/rxrpc/conn_service.c b/net/rxrpc/conn_service.c
new file mode 100644
index 0000000..cdcac50
--- /dev/null
+++ b/net/rxrpc/conn_service.c
@@ -0,0 +1,145 @@
+/* Service connection management
+ *
+ * Copyright (C) 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 Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/slab.h>
+#include "ar-internal.h"
+
+/*
+ * get a record of an incoming connection
+ */
+struct rxrpc_connection *rxrpc_incoming_connection(struct rxrpc_local *local,
+						   struct rxrpc_peer *peer,
+						   struct sk_buff *skb)
+{
+	struct rxrpc_connection *conn, *candidate = NULL;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rb_node *p, **pp;
+	const char *new = "old";
+	u32 epoch, cid;
+
+	_enter("");
+
+	ASSERT(sp->hdr.flags & RXRPC_CLIENT_INITIATED);
+
+	epoch = sp->hdr.epoch;
+	cid = sp->hdr.cid & RXRPC_CIDMASK;
+
+	/* search the connection list first */
+	read_lock_bh(&peer->conn_lock);
+
+	p = peer->service_conns.rb_node;
+	while (p) {
+		conn = rb_entry(p, struct rxrpc_connection, service_node);
+
+		_debug("maybe %x", conn->proto.cid);
+
+		if (epoch < conn->proto.epoch)
+			p = p->rb_left;
+		else if (epoch > conn->proto.epoch)
+			p = p->rb_right;
+		else if (cid < conn->proto.cid)
+			p = p->rb_left;
+		else if (cid > conn->proto.cid)
+			p = p->rb_right;
+		else
+			goto found_extant_connection;
+	}
+	read_unlock_bh(&peer->conn_lock);
+
+	/* not yet present - create a candidate for a new record and then
+	 * redo the search */
+	candidate = rxrpc_alloc_connection(GFP_NOIO);
+	if (!candidate) {
+		_leave(" = -ENOMEM");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	candidate->proto.local		= local;
+	candidate->proto.epoch		= sp->hdr.epoch;
+	candidate->proto.cid		= sp->hdr.cid & RXRPC_CIDMASK;
+	candidate->proto.in_clientflag	= RXRPC_CLIENT_INITIATED;
+	candidate->params.local		= local;
+	candidate->params.peer		= peer;
+	candidate->params.service_id	= sp->hdr.serviceId;
+	candidate->security_ix		= sp->hdr.securityIndex;
+	candidate->out_clientflag	= 0;
+	candidate->state		= RXRPC_CONN_SERVICE;
+	if (candidate->params.service_id)
+		candidate->state	= RXRPC_CONN_SERVICE_UNSECURED;
+
+	write_lock_bh(&peer->conn_lock);
+
+	pp = &peer->service_conns.rb_node;
+	p = NULL;
+	while (*pp) {
+		p = *pp;
+		conn = rb_entry(p, struct rxrpc_connection, service_node);
+
+		if (epoch < conn->proto.epoch)
+			pp = &(*pp)->rb_left;
+		else if (epoch > conn->proto.epoch)
+			pp = &(*pp)->rb_right;
+		else if (cid < conn->proto.cid)
+			pp = &(*pp)->rb_left;
+		else if (cid > conn->proto.cid)
+			pp = &(*pp)->rb_right;
+		else
+			goto found_extant_second;
+	}
+
+	/* we can now add the new candidate to the list */
+	conn = candidate;
+	candidate = NULL;
+	rb_link_node(&conn->service_node, p, pp);
+	rb_insert_color(&conn->service_node, &peer->service_conns);
+	rxrpc_get_peer(peer);
+	rxrpc_get_local(local);
+
+	write_unlock_bh(&peer->conn_lock);
+
+	write_lock(&rxrpc_connection_lock);
+	list_add_tail(&conn->link, &rxrpc_connections);
+	write_unlock(&rxrpc_connection_lock);
+
+	new = "new";
+
+success:
+	_net("CONNECTION %s %d {%x}", new, conn->debug_id, conn->proto.cid);
+
+	_leave(" = %p {u=%d}", conn, atomic_read(&conn->usage));
+	return conn;
+
+	/* we found the connection in the list immediately */
+found_extant_connection:
+	if (sp->hdr.securityIndex != conn->security_ix) {
+		read_unlock_bh(&peer->conn_lock);
+		goto security_mismatch;
+	}
+	rxrpc_get_connection(conn);
+	read_unlock_bh(&peer->conn_lock);
+	goto success;
+
+	/* we found the connection on the second time through the list */
+found_extant_second:
+	if (sp->hdr.securityIndex != conn->security_ix) {
+		write_unlock_bh(&peer->conn_lock);
+		goto security_mismatch;
+	}
+	rxrpc_get_connection(conn);
+	write_unlock_bh(&peer->conn_lock);
+	kfree(candidate);
+	goto success;
+
+security_mismatch:
+	kfree(candidate);
+	_leave(" = -EKEYREJECTED");
+	return ERR_PTR(-EKEYREJECTED);
+}