Merge branch 'rprpc-2nd-rewrite-part-1'

David Howells says:

====================
RxRPC: 2nd rewrite part 1

Okay, I'm in the process of rewriting the RxRPC rewrite.  The primary aim of
this second rewrite is to strictly control the number of active connections we
know about and to get rid of connections we don't need much more quickly.

On top of this, there are fixes to the protocol handling which will all occur
in later parts.

Here's the first set of patches from the second go, aimed at net-next.  These
are all fixes and cleanups preparatory to the main event.

Notable parts of this set include:

 (1) A fix for the AFS filesystem to wait for outstanding calls to complete
     before closing the RxRPC socket.

 (2) Differentiation of local and remote abort codes.  At a future point
     userspace will get to see this via control message data on recvmsg().

 (3) Absorb the rxkad module into the af_rxrpc module to prevent a dependency
     loop.

 (4) Create a null security module and unconditionalise calls into the
     security module that's in force (there will always be a security module
     applied to a connection, even if it's just the null one).
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

20 files changed, 374 insertions, 326 deletions

diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index b506428..63cd9f9 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -65,6 +65,12 @@ static void afs_async_workfn(struct work_struct *work)
 	call->async_workfn(call);
 }
 
+static int afs_wait_atomic_t(atomic_t *p)
+{
+	schedule();
+	return 0;
+}
+
 /*
  * open an RxRPC socket and bind it to be a server for callback notifications
  * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
@@ -126,13 +132,16 @@ void afs_close_socket(void)
 {
 	_enter("");
 
+	wait_on_atomic_t(&afs_outstanding_calls, afs_wait_atomic_t,
+			 TASK_UNINTERRUPTIBLE);
+	_debug("no outstanding calls");
+
 	sock_release(afs_socket);
 
 	_debug("dework");
 	destroy_workqueue(afs_async_calls);
 
 	ASSERTCMP(atomic_read(&afs_outstanding_skbs), ==, 0);
-	ASSERTCMP(atomic_read(&afs_outstanding_calls), ==, 0);
 	_leave("");
 }
 
@@ -178,8 +187,6 @@ static void afs_free_call(struct afs_call *call)
 {
 	_debug("DONE %p{%s} [%d]",
 	       call, call->type->name, atomic_read(&afs_outstanding_calls));
-	if (atomic_dec_return(&afs_outstanding_calls) == -1)
-		BUG();
 
 	ASSERTCMP(call->rxcall, ==, NULL);
 	ASSERT(!work_pending(&call->async_work));
@@ -188,6 +195,9 @@ static void afs_free_call(struct afs_call *call)
 
 	kfree(call->request);
 	kfree(call);
+
+	if (atomic_dec_and_test(&afs_outstanding_calls))
+		wake_up_atomic_t(&afs_outstanding_calls);
 }
 
 /*
@@ -420,9 +430,11 @@ error_kill_call:
 }
 
 /*
- * handles intercepted messages that were arriving in the socket's Rx queue
- * - called with the socket receive queue lock held to ensure message ordering
- * - called with softirqs disabled
+ * Handles intercepted messages that were arriving in the socket's Rx queue.
+ *
+ * Called from the AF_RXRPC call processor in waitqueue process context.  For
+ * each call, it is guaranteed this will be called in order of packet to be
+ * delivered.
  */
 static void afs_rx_interceptor(struct sock *sk, unsigned long user_call_ID,
 			       struct sk_buff *skb)
@@ -513,6 +525,12 @@ static void afs_deliver_to_call(struct afs_call *call)
 			call->state = AFS_CALL_ABORTED;
 			_debug("Rcv ABORT %u -> %d", abort_code, call->error);
 			break;
+		case RXRPC_SKB_MARK_LOCAL_ABORT:
+			abort_code = rxrpc_kernel_get_abort_code(skb);
+			call->error = call->type->abort_to_error(abort_code);
+			call->state = AFS_CALL_ABORTED;
+			_debug("Loc ABORT %u -> %d", abort_code, call->error);
+			break;
 		case RXRPC_SKB_MARK_NET_ERROR:
 			call->error = -rxrpc_kernel_get_error_number(skb);
 			call->state = AFS_CALL_ERROR;
diff --git a/include/net/af_rxrpc.h b/include/net/af_rxrpc.h
index e797d45..ac1bc3c 100644
--- a/include/net/af_rxrpc.h
+++ b/include/net/af_rxrpc.h
@@ -12,6 +12,7 @@
 #ifndef _NET_RXRPC_H
 #define _NET_RXRPC_H
 
+#include <linux/skbuff.h>
 #include <linux/rxrpc.h>
 
 struct rxrpc_call;
@@ -19,11 +20,12 @@ struct rxrpc_call;
 /*
  * the mark applied to socket buffers that may be intercepted
  */
-enum {
+enum rxrpc_skb_mark {
 	RXRPC_SKB_MARK_DATA,		/* data message */
 	RXRPC_SKB_MARK_FINAL_ACK,	/* final ACK received message */
 	RXRPC_SKB_MARK_BUSY,		/* server busy message */
 	RXRPC_SKB_MARK_REMOTE_ABORT,	/* remote abort message */
+	RXRPC_SKB_MARK_LOCAL_ABORT,	/* local abort message */
 	RXRPC_SKB_MARK_NET_ERROR,	/* network error message */
 	RXRPC_SKB_MARK_LOCAL_ERROR,	/* local error message */
 	RXRPC_SKB_MARK_NEW_CALL,	/* local error message */
diff --git a/include/rxrpc/packet.h b/include/rxrpc/packet.h
index 9ebab3a..b201744 100644
--- a/include/rxrpc/packet.h
+++ b/include/rxrpc/packet.h
@@ -68,8 +68,6 @@ struct rxrpc_wire_header {
 
 } __packed;
 
-extern const char *rxrpc_pkts[];
-
 #define RXRPC_SUPPORTED_PACKET_TYPES (			\
 		(1 << RXRPC_PACKET_TYPE_DATA) |		\
 		(1 << RXRPC_PACKET_TYPE_ACK) |		\
diff --git a/net/rxrpc/Kconfig b/net/rxrpc/Kconfig
index 23dcef1..784c531 100644
--- a/net/rxrpc/Kconfig
+++ b/net/rxrpc/Kconfig
@@ -30,7 +30,7 @@ config AF_RXRPC_DEBUG
 
 
 config RXKAD
-	tristate "RxRPC Kerberos security"
+	bool "RxRPC Kerberos security"
 	depends on AF_RXRPC
 	select CRYPTO
 	select CRYPTO_MANAGER
diff --git a/net/rxrpc/Makefile b/net/rxrpc/Makefile
index ec126f9..e05a06e 100644
--- a/net/rxrpc/Makefile
+++ b/net/rxrpc/Makefile
@@ -18,11 +18,12 @@ af-rxrpc-y := \
 	ar-recvmsg.o \
 	ar-security.o \
 	ar-skbuff.o \
-	ar-transport.o
+	ar-transport.o \
+	insecure.o \
+	misc.o
 
 af-rxrpc-$(CONFIG_PROC_FS) += ar-proc.o
+af-rxrpc-$(CONFIG_RXKAD) += rxkad.o
 af-rxrpc-$(CONFIG_SYSCTL) += sysctl.o
 
 obj-$(CONFIG_AF_RXRPC) += af-rxrpc.o
-
-obj-$(CONFIG_RXKAD) += rxkad.o
diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
index 9d935fa..e45e94c 100644
--- a/net/rxrpc/af_rxrpc.c
+++ b/net/rxrpc/af_rxrpc.c
@@ -806,6 +806,12 @@ static int __init af_rxrpc_init(void)
 		goto error_work_queue;
 	}
 
+	ret = rxrpc_init_security();
+	if (ret < 0) {
+		printk(KERN_CRIT "RxRPC: Cannot initialise security\n");
+		goto error_security;
+	}
+
 	ret = proto_register(&rxrpc_proto, 1);
 	if (ret < 0) {
 		printk(KERN_CRIT "RxRPC: Cannot register protocol\n");
@@ -853,6 +859,8 @@ error_sock:
 	proto_unregister(&rxrpc_proto);
 error_proto:
 	destroy_workqueue(rxrpc_workqueue);
+error_security:
+	rxrpc_exit_security();
 error_work_queue:
 	kmem_cache_destroy(rxrpc_call_jar);
 error_call_jar:
@@ -883,6 +891,7 @@ static void __exit af_rxrpc_exit(void)
 	remove_proc_entry("rxrpc_conns", init_net.proc_net);
 	remove_proc_entry("rxrpc_calls", init_net.proc_net);
 	destroy_workqueue(rxrpc_workqueue);
+	rxrpc_exit_security();
 	kmem_cache_destroy(rxrpc_call_jar);
 	_leave("");
 }
diff --git a/net/rxrpc/ar-accept.c b/net/rxrpc/ar-accept.c
index 277731a..e7a7f05 100644
--- a/net/rxrpc/ar-accept.c
+++ b/net/rxrpc/ar-accept.c
@@ -108,7 +108,7 @@ static int rxrpc_accept_incoming_call(struct rxrpc_local *local,
 		goto error;
 	}
 
-	conn = rxrpc_incoming_connection(trans, &sp->hdr, GFP_NOIO);
+	conn = rxrpc_incoming_connection(trans, &sp->hdr);
 	rxrpc_put_transport(trans);
 	if (IS_ERR(conn)) {
 		_debug("no conn");
@@ -116,7 +116,7 @@ static int rxrpc_accept_incoming_call(struct rxrpc_local *local,
 		goto error;
 	}
 
-	call = rxrpc_incoming_call(rx, conn, &sp->hdr, GFP_NOIO);
+	call = rxrpc_incoming_call(rx, conn, &sp->hdr);
 	rxrpc_put_connection(conn);
 	if (IS_ERR(call)) {
 		_debug("no call");
diff --git a/net/rxrpc/ar-ack.c b/net/rxrpc/ar-ack.c
index 16d9670..374478e 100644
--- a/net/rxrpc/ar-ack.c
+++ b/net/rxrpc/ar-ack.c
@@ -20,74 +20,6 @@
 #include "ar-internal.h"
 
 /*
- * How long to wait before scheduling ACK generation after seeing a
- * packet with RXRPC_REQUEST_ACK set (in jiffies).
- */
-unsigned int rxrpc_requested_ack_delay = 1;
-
-/*
- * How long to wait before scheduling an ACK with subtype DELAY (in jiffies).
- *
- * We use this when we've received new data packets.  If those packets aren't
- * all consumed within this time we will send a DELAY ACK if an ACK was not
- * requested to let the sender know it doesn't need to resend.
- */
-unsigned int rxrpc_soft_ack_delay = 1 * HZ;
-
-/*
- * How long to wait before scheduling an ACK with subtype IDLE (in jiffies).
- *
- * We use this when we've consumed some previously soft-ACK'd packets when
- * further packets aren't immediately received to decide when to send an IDLE
- * ACK let the other end know that it can free up its Tx buffer space.
- */
-unsigned int rxrpc_idle_ack_delay = 0.5 * HZ;
-
-/*
- * Receive window size in packets.  This indicates the maximum number of
- * unconsumed received packets we're willing to retain in memory.  Once this
- * limit is hit, we should generate an EXCEEDS_WINDOW ACK and discard further
- * packets.
- */
-unsigned int rxrpc_rx_window_size = 32;
-
-/*
- * Maximum Rx MTU size.  This indicates to the sender the size of jumbo packet
- * made by gluing normal packets together that we're willing to handle.
- */
-unsigned int rxrpc_rx_mtu = 5692;
-
-/*
- * The maximum number of fragments in a received jumbo packet that we tell the
- * sender that we're willing to handle.
- */
-unsigned int rxrpc_rx_jumbo_max = 4;
-
-static const char *rxrpc_acks(u8 reason)
-{
-	static const char *const str[] = {
-		"---", "REQ", "DUP", "OOS", "WIN", "MEM", "PNG", "PNR", "DLY",
-		"IDL", "-?-"
-	};
-
-	if (reason >= ARRAY_SIZE(str))
-		reason = ARRAY_SIZE(str) - 1;
-	return str[reason];
-}
-
-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, u8 ack_reason,
@@ -426,7 +358,7 @@ static void rxrpc_rotate_tx_window(struct rxrpc_call *call, u32 hard)
 	int tail = call->acks_tail, old_tail;
 	int win = CIRC_CNT(call->acks_head, tail, call->acks_winsz);
 
-	kenter("{%u,%u},%u", call->acks_hard, win, hard);
+	_enter("{%u,%u},%u", call->acks_hard, win, hard);
 
 	ASSERTCMP(hard - call->acks_hard, <=, win);
 
@@ -656,7 +588,8 @@ process_further:
 		_proto("OOSQ DATA %%%u { #%u }", sp->hdr.serial, sp->hdr.seq);
 
 		/* secured packets must be verified and possibly decrypted */
-		if (rxrpc_verify_packet(call, skb, _abort_code) < 0)
+		if (call->conn->security->verify_packet(call, skb,
+							_abort_code) < 0)
 			goto protocol_error;
 
 		rxrpc_insert_oos_packet(call, skb);
@@ -901,8 +834,8 @@ void rxrpc_process_call(struct work_struct *work)
 
 	/* 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_name	= &call->conn->trans->peer->srx.transport;
+	msg.msg_namelen	= call->conn->trans->peer->srx.transport_len;
 	msg.msg_control	= NULL;
 	msg.msg_controllen = 0;
 	msg.msg_flags	= 0;
@@ -973,7 +906,7 @@ void rxrpc_process_call(struct work_struct *work)
 				       ECONNABORTED, true) < 0)
 			goto no_mem;
 		whdr.type = RXRPC_PACKET_TYPE_ABORT;
-		data = htonl(call->abort_code);
+		data = htonl(call->local_abort);
 		iov[1].iov_base = &data;
 		iov[1].iov_len = sizeof(data);
 		genbit = RXRPC_CALL_EV_ABORT;
@@ -1036,7 +969,7 @@ void rxrpc_process_call(struct work_struct *work)
 		write_lock_bh(&call->state_lock);
 		if (call->state <= RXRPC_CALL_COMPLETE) {
 			call->state = RXRPC_CALL_LOCALLY_ABORTED;
-			call->abort_code = RX_CALL_TIMEOUT;
+			call->local_abort = RX_CALL_TIMEOUT;
 			set_bit(RXRPC_CALL_EV_ABORT, &call->events);
 		}
 		write_unlock_bh(&call->state_lock);
diff --git a/net/rxrpc/ar-call.c b/net/rxrpc/ar-call.c
index 7c8d300..571a41f 100644
--- a/net/rxrpc/ar-call.c
+++ b/net/rxrpc/ar-call.c
@@ -411,18 +411,17 @@ found_extant_second:
  */
 struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *rx,
 				       struct rxrpc_connection *conn,
-				       struct rxrpc_host_header *hdr,
-				       gfp_t gfp)
+				       struct rxrpc_host_header *hdr)
 {
 	struct rxrpc_call *call, *candidate;
 	struct rb_node **p, *parent;
 	u32 call_id;
 
-	_enter(",%d,,%x", conn->debug_id, gfp);
+	_enter(",%d", conn->debug_id);
 
 	ASSERT(rx != NULL);
 
-	candidate = rxrpc_alloc_call(gfp);
+	candidate = rxrpc_alloc_call(GFP_NOIO);
 	if (!candidate)
 		return ERR_PTR(-EBUSY);
 
@@ -682,7 +681,7 @@ void rxrpc_release_call(struct rxrpc_call *call)
 	    call->state != RXRPC_CALL_CLIENT_FINAL_ACK) {
 		_debug("+++ ABORTING STATE %d +++\n", call->state);
 		call->state = RXRPC_CALL_LOCALLY_ABORTED;
-		call->abort_code = RX_CALL_DEAD;
+		call->local_abort = RX_CALL_DEAD;
 		set_bit(RXRPC_CALL_EV_ABORT, &call->events);
 		rxrpc_queue_call(call);
 	}
@@ -758,7 +757,7 @@ static void rxrpc_mark_call_released(struct rxrpc_call *call)
 		if (call->state < RXRPC_CALL_COMPLETE) {
 			_debug("abort call %p", call);
 			call->state = RXRPC_CALL_LOCALLY_ABORTED;
-			call->abort_code = RX_CALL_DEAD;
+			call->local_abort = RX_CALL_DEAD;
 			if (!test_and_set_bit(RXRPC_CALL_EV_ABORT, &call->events))
 				sched = true;
 		}
diff --git a/net/rxrpc/ar-connection.c b/net/rxrpc/ar-connection.c
index 9942da1..97f4fae 100644
--- a/net/rxrpc/ar-connection.c
+++ b/net/rxrpc/ar-connection.c
@@ -207,6 +207,7 @@ static struct rxrpc_connection *rxrpc_alloc_connection(gfp_t gfp)
 		INIT_LIST_HEAD(&conn->bundle_link);
 		conn->calls = RB_ROOT;
 		skb_queue_head_init(&conn->rx_queue);
+		conn->security = &rxrpc_no_security;
 		rwlock_init(&conn->lock);
 		spin_lock_init(&conn->state_lock);
 		atomic_set(&conn->usage, 1);
@@ -564,8 +565,7 @@ int rxrpc_connect_call(struct rxrpc_sock *rx,
 		     candidate->debug_id, candidate->trans->debug_id);
 
 		rxrpc_assign_connection_id(candidate);
-		if (candidate->security)
-			candidate->security->prime_packet_security(candidate);
+		candidate->security->prime_packet_security(candidate);
 
 		/* leave the candidate lurking in zombie mode attached to the
 		 * bundle until we're ready for it */
@@ -619,8 +619,7 @@ interrupted:
  */
 struct rxrpc_connection *
 rxrpc_incoming_connection(struct rxrpc_transport *trans,
-			  struct rxrpc_host_header *hdr,
-			  gfp_t gfp)
+			  struct rxrpc_host_header *hdr)
 {
 	struct rxrpc_connection *conn, *candidate = NULL;
 	struct rb_node *p, **pp;
@@ -659,7 +658,7 @@ rxrpc_incoming_connection(struct rxrpc_transport *trans,
 
 	/* not yet present - create a candidate for a new record and then
 	 * redo the search */
-	candidate = rxrpc_alloc_connection(gfp);
+	candidate = rxrpc_alloc_connection(GFP_NOIO);
 	if (!candidate) {
 		_leave(" = -ENOMEM");
 		return ERR_PTR(-ENOMEM);
@@ -831,7 +830,10 @@ static void rxrpc_destroy_connection(struct rxrpc_connection *conn)
 	ASSERT(RB_EMPTY_ROOT(&conn->calls));
 	rxrpc_purge_queue(&conn->rx_queue);
 
-	rxrpc_clear_conn_security(conn);
+	conn->security->clear(conn);
+	key_put(conn->key);
+	key_put(conn->server_key);
+
 	rxrpc_put_transport(conn->trans);
 	kfree(conn);
 	_leave("");
diff --git a/net/rxrpc/ar-connevent.c b/net/rxrpc/ar-connevent.c
index 1bdaaed..5f95639 100644
--- a/net/rxrpc/ar-connevent.c
+++ b/net/rxrpc/ar-connevent.c
@@ -40,11 +40,13 @@ static void rxrpc_abort_calls(struct rxrpc_connection *conn, int state,
 		write_lock(&call->state_lock);
 		if (call->state <= RXRPC_CALL_COMPLETE) {
 			call->state = state;
-			call->abort_code = abort_code;
-			if (state == RXRPC_CALL_LOCALLY_ABORTED)
+			if (state == RXRPC_CALL_LOCALLY_ABORTED) {
+				call->local_abort = conn->local_abort;
 				set_bit(RXRPC_CALL_EV_CONN_ABORT, &call->events);
-			else
+			} else {
+				call->remote_abort = conn->remote_abort;
 				set_bit(RXRPC_CALL_EV_RCVD_ABORT, &call->events);
+			}
 			rxrpc_queue_call(call);
 		}
 		write_unlock(&call->state_lock);
@@ -84,8 +86,8 @@ static int rxrpc_abort_connection(struct rxrpc_connection *conn,
 
 	rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, abort_code);
 
-	msg.msg_name	= &conn->trans->peer->srx.transport.sin;
-	msg.msg_namelen	= sizeof(conn->trans->peer->srx.transport.sin);
+	msg.msg_name	= &conn->trans->peer->srx.transport;
+	msg.msg_namelen	= conn->trans->peer->srx.transport_len;
 	msg.msg_control	= NULL;
 	msg.msg_controllen = 0;
 	msg.msg_flags	= 0;
@@ -101,7 +103,7 @@ static int rxrpc_abort_connection(struct rxrpc_connection *conn,
 	whdr._rsvd	= 0;
 	whdr.serviceId	= htons(conn->service_id);
 
-	word = htonl(abort_code);
+	word		= htonl(conn->local_abort);
 
 	iov[0].iov_base	= &whdr;
 	iov[0].iov_len	= sizeof(whdr);
@@ -112,7 +114,7 @@ static int rxrpc_abort_connection(struct rxrpc_connection *conn,
 
 	serial = atomic_inc_return(&conn->serial);
 	whdr.serial = htonl(serial);
-	_proto("Tx CONN ABORT %%%u { %d }", serial, abort_code);
+	_proto("Tx CONN ABORT %%%u { %d }", serial, conn->local_abort);
 
 	ret = kernel_sendmsg(conn->trans->local->socket, &msg, iov, 2, len);
 	if (ret < 0) {
@@ -172,15 +174,10 @@ static int rxrpc_process_event(struct rxrpc_connection *conn,
 		return -ECONNABORTED;
 
 	case RXRPC_PACKET_TYPE_CHALLENGE:
-		if (conn->security)
-			return conn->security->respond_to_challenge(
-				conn, skb, _abort_code);
-		return -EPROTO;
+		return conn->security->respond_to_challenge(conn, skb,
+							    _abort_code);
 
 	case RXRPC_PACKET_TYPE_RESPONSE:
-		if (!conn->security)
-			return -EPROTO;
-
 		ret = conn->security->verify_response(conn, skb, _abort_code);
 		if (ret < 0)
 			return ret;
@@ -236,8 +233,6 @@ static void rxrpc_secure_connection(struct rxrpc_connection *conn)
 		}
 	}
 
-	ASSERT(conn->security != NULL);
-
 	if (conn->security->issue_challenge(conn) < 0) {
 		abort_code = RX_CALL_DEAD;
 		ret = -ENOMEM;
diff --git a/net/rxrpc/ar-input.c b/net/rxrpc/ar-input.c
index 4824a82..01e0381 100644
--- a/net/rxrpc/ar-input.c
+++ b/net/rxrpc/ar-input.c
@@ -25,12 +25,6 @@
 #include <net/net_namespace.h>
 #include "ar-internal.h"
 
-const char *rxrpc_pkts[] = {
-	"?00",
-	"DATA", "ACK", "BUSY", "ABORT", "ACKALL", "CHALL", "RESP", "DEBUG",
-	"?09", "?10", "?11", "?12", "VERSION", "?14", "?15"
-};
-
 /*
  * queue a packet for recvmsg to pass to userspace
  * - the caller must hold a lock on call->lock
@@ -199,7 +193,7 @@ static int rxrpc_fast_process_data(struct rxrpc_call *call,
 
 	/* if the packet need security things doing to it, then it goes down
 	 * the slow path */
-	if (call->conn->security)
+	if (call->conn->security_ix)
 		goto enqueue_packet;
 
 	sp->call = call;
@@ -355,7 +349,7 @@ void rxrpc_fast_process_packet(struct rxrpc_call *call, struct sk_buff *skb)
 		write_lock_bh(&call->state_lock);
 		if (call->state < RXRPC_CALL_COMPLETE) {
 			call->state = RXRPC_CALL_REMOTELY_ABORTED;
-			call->abort_code = abort_code;
+			call->remote_abort = abort_code;
 			set_bit(RXRPC_CALL_EV_RCVD_ABORT, &call->events);
 			rxrpc_queue_call(call);
 		}
@@ -428,7 +422,7 @@ protocol_error:
 protocol_error_locked:
 	if (call->state <= RXRPC_CALL_COMPLETE) {
 		call->state = RXRPC_CALL_LOCALLY_ABORTED;
-		call->abort_code = RX_PROTOCOL_ERROR;
+		call->local_abort = RX_PROTOCOL_ERROR;
 		set_bit(RXRPC_CALL_EV_ABORT, &call->events);
 		rxrpc_queue_call(call);
 	}
@@ -500,7 +494,7 @@ protocol_error:
 	write_lock_bh(&call->state_lock);
 	if (call->state <= RXRPC_CALL_COMPLETE) {
 		call->state = RXRPC_CALL_LOCALLY_ABORTED;
-		call->abort_code = RX_PROTOCOL_ERROR;
+		call->local_abort = RX_PROTOCOL_ERROR;
 		set_bit(RXRPC_CALL_EV_ABORT, &call->events);
 		rxrpc_queue_call(call);
 	}
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index cd6cdbe..f0b807a 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -9,6 +9,7 @@
  * 2 of the License, or (at your option) any later version.
  */
 
+#include <net/sock.h>
 #include <rxrpc/packet.h>
 
 #if 0
@@ -124,11 +125,15 @@ enum rxrpc_command {
  * RxRPC security module interface
  */
 struct rxrpc_security {
-	struct module		*owner;		/* providing module */
-	struct list_head	link;		/* link in master list */
 	const char		*name;		/* name of this service */
 	u8			security_index;	/* security type provided */
 
+	/* Initialise a security service */
+	int (*init)(void);
+
+	/* Clean up a security service */
+	void (*exit)(void);
+
 	/* initialise a connection's security */
 	int (*init_connection_security)(struct rxrpc_connection *);
 
@@ -268,7 +273,7 @@ struct rxrpc_connection {
 	struct rb_root		calls;		/* calls on this connection */
 	struct sk_buff_head	rx_queue;	/* received conn-level packets */
 	struct rxrpc_call	*channels[RXRPC_MAXCALLS]; /* channels (active calls) */
-	struct rxrpc_security	*security;	/* applied security module */
+	const struct rxrpc_security *security;	/* applied security module */
 	struct key		*key;		/* security for this connection (client) */
 	struct key		*server_key;	/* security for this service */
 	struct crypto_skcipher	*cipher;	/* encryption handle */
@@ -289,7 +294,9 @@ struct rxrpc_connection {
 		RXRPC_CONN_LOCALLY_ABORTED,	/* - conn aborted locally */
 		RXRPC_CONN_NETWORK_ERROR,	/* - conn terminated by network error */
 	} state;
-	int			error;		/* error code for local abort */
+	u32			local_abort;	/* local abort code */
+	u32			remote_abort;	/* remote abort code */
+	int			error;		/* local error incurred */
 	int			debug_id;	/* debug ID for printks */
 	unsigned int		call_counter;	/* call ID counter */
 	atomic_t		serial;		/* packet serial number counter */
@@ -399,7 +406,9 @@ struct rxrpc_call {
 	rwlock_t		state_lock;	/* lock for state transition */
 	atomic_t		usage;
 	atomic_t		sequence;	/* Tx data packet sequence counter */
-	u32			abort_code;	/* local/remote abort code */
+	u32			local_abort;	/* local abort code */
+	u32			remote_abort;	/* remote abort code */
+	int			error;		/* local error incurred */
 	enum rxrpc_call_state	state : 8;	/* current state of call */
 	int			debug_id;	/* debug ID for printks */
 	u8			channel;	/* connection channel occupied by this call */
@@ -453,7 +462,7 @@ static inline void rxrpc_abort_call(struct rxrpc_call *call, u32 abort_code)
 {
 	write_lock_bh(&call->state_lock);
 	if (call->state < RXRPC_CALL_COMPLETE) {
-		call->abort_code = abort_code;
+		call->local_abort = abort_code;
 		call->state = RXRPC_CALL_LOCALLY_ABORTED;
 		set_bit(RXRPC_CALL_EV_ABORT, &call->events);
 	}
@@ -478,13 +487,6 @@ int rxrpc_reject_call(struct rxrpc_sock *);
 /*
  * ar-ack.c
  */
-extern unsigned int rxrpc_requested_ack_delay;
-extern unsigned int rxrpc_soft_ack_delay;
-extern unsigned int rxrpc_idle_ack_delay;
-extern unsigned int rxrpc_rx_window_size;
-extern unsigned int rxrpc_rx_mtu;
-extern unsigned int rxrpc_rx_jumbo_max;
-
 void __rxrpc_propose_ACK(struct rxrpc_call *, u8, u32, bool);
 void rxrpc_propose_ACK(struct rxrpc_call *, u8, u32, bool);
 void rxrpc_process_call(struct work_struct *);
@@ -506,7 +508,7 @@ struct rxrpc_call *rxrpc_get_client_call(struct rxrpc_sock *,
 					 unsigned long, int, gfp_t);
 struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *,
 				       struct rxrpc_connection *,
-				       struct rxrpc_host_header *, gfp_t);
+				       struct rxrpc_host_header *);
 struct rxrpc_call *rxrpc_find_server_call(struct rxrpc_sock *, unsigned long);
 void rxrpc_release_call(struct rxrpc_call *);
 void rxrpc_release_calls_on_socket(struct rxrpc_sock *);
@@ -531,8 +533,7 @@ void __exit rxrpc_destroy_all_connections(void);
 struct rxrpc_connection *rxrpc_find_connection(struct rxrpc_transport *,
 					       struct rxrpc_host_header *);
 extern struct rxrpc_connection *
-rxrpc_incoming_connection(struct rxrpc_transport *, struct rxrpc_host_header *,
-			  gfp_t);
+rxrpc_incoming_connection(struct rxrpc_transport *, struct rxrpc_host_header *);
 
 /*
  * ar-connevent.c
@@ -550,8 +551,6 @@ void rxrpc_UDP_error_handler(struct work_struct *);
 /*
  * ar-input.c
  */
-extern const char *rxrpc_pkts[];
-
 void rxrpc_data_ready(struct sock *);
 int rxrpc_queue_rcv_skb(struct rxrpc_call *, struct sk_buff *, bool, bool);
 void rxrpc_fast_process_packet(struct rxrpc_call *, struct sk_buff *);
@@ -610,14 +609,10 @@ int rxrpc_recvmsg(struct socket *, struct msghdr *, size_t, int);
 /*
  * ar-security.c
  */
-int rxrpc_register_security(struct rxrpc_security *);
-void rxrpc_unregister_security(struct rxrpc_security *);
+int __init rxrpc_init_security(void);
+void rxrpc_exit_security(void);
 int rxrpc_init_client_conn_security(struct rxrpc_connection *);
 int rxrpc_init_server_conn_security(struct rxrpc_connection *);
-int rxrpc_secure_packet(const struct rxrpc_call *, struct sk_buff *, size_t,
-			void *);
-int rxrpc_verify_packet(const struct rxrpc_call *, struct sk_buff *, u32 *);
-void rxrpc_clear_conn_security(struct rxrpc_connection *);
 
 /*
  * ar-skbuff.c
@@ -637,6 +632,33 @@ struct rxrpc_transport *rxrpc_find_transport(struct rxrpc_local *,
 					     struct rxrpc_peer *);
 
 /*
+ * insecure.c
+ */
+extern const struct rxrpc_security rxrpc_no_security;
+
+/*
+ * misc.c
+ */
+extern unsigned int rxrpc_requested_ack_delay;
+extern unsigned int rxrpc_soft_ack_delay;
+extern unsigned int rxrpc_idle_ack_delay;
+extern unsigned int rxrpc_rx_window_size;
+extern unsigned int rxrpc_rx_mtu;
+extern unsigned int rxrpc_rx_jumbo_max;
+
+extern const char *const rxrpc_pkts[];
+extern const s8 rxrpc_ack_priority[];
+
+extern const char *rxrpc_acks(u8 reason);
+
+/*
+ * rxkad.c
+ */
+#ifdef CONFIG_RXKAD
+extern const struct rxrpc_security rxkad;
+#endif
+
+/*
  * sysctl.c
  */
 #ifdef CONFIG_SYSCTL
diff --git a/net/rxrpc/ar-output.c b/net/rxrpc/ar-output.c
index d36fb6e..51cb100 100644
--- a/net/rxrpc/ar-output.c
+++ b/net/rxrpc/ar-output.c
@@ -110,7 +110,7 @@ static void rxrpc_send_abort(struct rxrpc_call *call, u32 abort_code)
 
 	if (call->state <= RXRPC_CALL_COMPLETE) {
 		call->state = RXRPC_CALL_LOCALLY_ABORTED;
-		call->abort_code = abort_code;
+		call->local_abort = abort_code;
 		set_bit(RXRPC_CALL_EV_ABORT, &call->events);
 		del_timer_sync(&call->resend_timer);
 		del_timer_sync(&call->ack_timer);
@@ -663,7 +663,7 @@ static int rxrpc_send_data(struct rxrpc_sock *rx,
 			size_t pad;
 
 			/* pad out if we're using security */
-			if (conn->security) {
+			if (conn->security_ix) {
 				pad = conn->security_size + skb->mark;
 				pad = conn->size_align - pad;
 				pad &= conn->size_align - 1;
@@ -695,7 +695,7 @@ static int rxrpc_send_data(struct rxrpc_sock *rx,
 			if (more && seq & 1)
 				sp->hdr.flags |= RXRPC_REQUEST_ACK;
 
-			ret = rxrpc_secure_packet(
+			ret = conn->security->secure_packet(
 				call, skb, skb->mark,
 				skb->head + sizeof(struct rxrpc_wire_header));
 			if (ret < 0)
diff --git a/net/rxrpc/ar-proc.c b/net/rxrpc/ar-proc.c
index 525b2ba..225163b 100644
--- a/net/rxrpc/ar-proc.c
+++ b/net/rxrpc/ar-proc.c
@@ -80,7 +80,7 @@ static int rxrpc_call_seq_show(struct seq_file *seq, void *v)
 		   call->conn->in_clientflag ? "Svc" : "Clt",
 		   atomic_read(&call->usage),
 		   rxrpc_call_states[call->state],
-		   call->abort_code,
+		   call->remote_abort ?: call->local_abort,
 		   call->user_call_ID);
 
 	return 0;
diff --git a/net/rxrpc/ar-recvmsg.c b/net/rxrpc/ar-recvmsg.c
index 64facba..160f092 100644
--- a/net/rxrpc/ar-recvmsg.c
+++ b/net/rxrpc/ar-recvmsg.c
@@ -288,7 +288,11 @@ receive_non_data_message:
 		ret = put_cmsg(msg, SOL_RXRPC, RXRPC_BUSY, 0, &abort_code);
 		break;
 	case RXRPC_SKB_MARK_REMOTE_ABORT:
-		abort_code = call->abort_code;
+		abort_code = call->remote_abort;
+		ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ABORT, 4, &abort_code);
+		break;
+	case RXRPC_SKB_MARK_LOCAL_ABORT:
+		abort_code = call->local_abort;
 		ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ABORT, 4, &abort_code);
 		break;
 	case RXRPC_SKB_MARK_NET_ERROR:
@@ -303,6 +307,7 @@ receive_non_data_message:
 			       &abort_code);
 		break;
 	default:
+		pr_err("RxRPC: Unknown packet mark %u\n", skb->mark);
 		BUG();
 		break;
 	}
@@ -401,9 +406,14 @@ u32 rxrpc_kernel_get_abort_code(struct sk_buff *skb)
 {
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 
-	ASSERTCMP(skb->mark, ==, RXRPC_SKB_MARK_REMOTE_ABORT);
-
-	return sp->call->abort_code;
+	switch (skb->mark) {
+	case RXRPC_SKB_MARK_REMOTE_ABORT:
+		return sp->call->remote_abort;
+	case RXRPC_SKB_MARK_LOCAL_ABORT:
+		return sp->call->local_abort;
+	default:
+		BUG();
+	}
 }
 
 EXPORT_SYMBOL(rxrpc_kernel_get_abort_code);
diff --git a/net/rxrpc/ar-security.c b/net/rxrpc/ar-security.c
index ceff639..d223253 100644
--- a/net/rxrpc/ar-security.c
+++ b/net/rxrpc/ar-security.c
@@ -22,109 +22,60 @@
 static LIST_HEAD(rxrpc_security_methods);
 static DECLARE_RWSEM(rxrpc_security_sem);
 
-/*
- * get an RxRPC security module
- */
-static struct rxrpc_security *rxrpc_security_get(struct rxrpc_security *sec)
-{
-	return try_module_get(sec->owner) ? sec : NULL;
-}
-
-/*
- * release an RxRPC security module
- */
-static void rxrpc_security_put(struct rxrpc_security *sec)
+static const struct rxrpc_security *rxrpc_security_types[] = {
+	[RXRPC_SECURITY_NONE]	= &rxrpc_no_security,
+#ifdef CONFIG_RXKAD
+	[RXRPC_SECURITY_RXKAD]	= &rxkad,
+#endif
+};
+
+int __init rxrpc_init_security(void)
 {
-	module_put(sec->owner);
-}
-
-/*
- * look up an rxrpc security module
- */
-static struct rxrpc_security *rxrpc_security_lookup(u8 security_index)
-{
-	struct rxrpc_security *sec = NULL;
-
-	_enter("");
+	int i, ret;
 
-	down_read(&rxrpc_security_sem);
-
-	list_for_each_entry(sec, &rxrpc_security_methods, link) {
-		if (sec->security_index == security_index) {
-			if (unlikely(!rxrpc_security_get(sec)))
-				break;
-			goto out;
+	for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++) {
+		if (rxrpc_security_types[i]) {
+			ret = rxrpc_security_types[i]->init();
+			if (ret < 0)
+				goto failed;
 		}
 	}
 
-	sec = NULL;
-out:
-	up_read(&rxrpc_security_sem);
-	_leave(" = %p [%s]", sec, sec ? sec->name : "");
-	return sec;
+	return 0;
+
+failed:
+	for (i--; i >= 0; i--)
+		if (rxrpc_security_types[i])
+			rxrpc_security_types[i]->exit();
+	return ret;
 }
 
-/**
- * rxrpc_register_security - register an RxRPC security handler
- * @sec: security module
- *
- * register an RxRPC security handler for use by RxRPC
- */
-int rxrpc_register_security(struct rxrpc_security *sec)
+void rxrpc_exit_security(void)
 {
-	struct rxrpc_security *psec;
-	int ret;
+	int i;
 
-	_enter("");
-	down_write(&rxrpc_security_sem);
-
-	ret = -EEXIST;
-	list_for_each_entry(psec, &rxrpc_security_methods, link) {
-		if (psec->security_index == sec->security_index)
-			goto out;
-	}
-
-	list_add(&sec->link, &rxrpc_security_methods);
-
-	printk(KERN_NOTICE "RxRPC: Registered security type %d '%s'\n",
-	       sec->security_index, sec->name);
-	ret = 0;
-
-out:
-	up_write(&rxrpc_security_sem);
-	_leave(" = %d", ret);
-	return ret;
+	for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++)
+		if (rxrpc_security_types[i])
+			rxrpc_security_types[i]->exit();
 }
 
-EXPORT_SYMBOL_GPL(rxrpc_register_security);
-
-/**
- * rxrpc_unregister_security - unregister an RxRPC security handler
- * @sec: security module
- *
- * unregister an RxRPC security handler
+/*
+ * look up an rxrpc security module
  */
-void rxrpc_unregister_security(struct rxrpc_security *sec)
+static const struct rxrpc_security *rxrpc_security_lookup(u8 security_index)
 {
-
-	_enter("");
-	down_write(&rxrpc_security_sem);
-	list_del_init(&sec->link);
-	up_write(&rxrpc_security_sem);
-
-	printk(KERN_NOTICE "RxRPC: Unregistered security type %d '%s'\n",
-	       sec->security_index, sec->name);
+	if (security_index >= ARRAY_SIZE(rxrpc_security_types))
+		return NULL;
+	return rxrpc_security_types[security_index];
 }
 
-EXPORT_SYMBOL_GPL(rxrpc_unregister_security);
-
 /*
  * initialise the security on a client connection
  */
 int rxrpc_init_client_conn_security(struct rxrpc_connection *conn)
 {
+	const struct rxrpc_security *sec;
 	struct rxrpc_key_token *token;
-	struct rxrpc_security *sec;
 	struct key *key = conn->key;
 	int ret;
 
@@ -148,8 +99,7 @@ int rxrpc_init_client_conn_security(struct rxrpc_connection *conn)
 
 	ret = conn->security->init_connection_security(conn);
 	if (ret < 0) {
-		rxrpc_security_put(conn->security);
-		conn->security = NULL;
+		conn->security = &rxrpc_no_security;
 		return ret;
 	}
 
@@ -162,7 +112,7 @@ int rxrpc_init_client_conn_security(struct rxrpc_connection *conn)
  */
 int rxrpc_init_server_conn_security(struct rxrpc_connection *conn)
 {
-	struct rxrpc_security *sec;
+	const struct rxrpc_security *sec;
 	struct rxrpc_local *local = conn->trans->local;
 	struct rxrpc_sock *rx;
 	struct key *key;
@@ -188,14 +138,12 @@ int rxrpc_init_server_conn_security(struct rxrpc_connection *conn)
 
 	/* the service appears to have died */
 	read_unlock_bh(&local->services_lock);
-	rxrpc_security_put(sec);
 	_leave(" = -ENOENT");
 	return -ENOENT;
 
 found_service:
 	if (!rx->securities) {
 		read_unlock_bh(&local->services_lock);
-		rxrpc_security_put(sec);
 		_leave(" = -ENOKEY");
 		return -ENOKEY;
 	}
@@ -205,7 +153,6 @@ found_service:
 			      &key_type_rxrpc_s, kdesc);
 	if (IS_ERR(kref)) {
 		read_unlock_bh(&local->services_lock);
-		rxrpc_security_put(sec);
 		_leave(" = %ld [search]", PTR_ERR(kref));
 		return PTR_ERR(kref);
 	}
@@ -219,46 +166,3 @@ found_service:
 	_leave(" = 0");
 	return 0;
 }
-
-/*
- * secure a packet prior to transmission
- */
-int rxrpc_secure_packet(const struct rxrpc_call *call,
-			struct sk_buff *skb,
-			size_t data_size,
-			void *sechdr)
-{
-	if (call->conn->security)
-		return call->conn->security->secure_packet(
-			call, skb, data_size, sechdr);
-	return 0;
-}
-
-/*
- * secure a packet prior to transmission
- */
-int rxrpc_verify_packet(const struct rxrpc_call *call, struct sk_buff *skb,
-			u32 *_abort_code)
-{
-	if (call->conn->security)
-		return call->conn->security->verify_packet(
-			call, skb, _abort_code);
-	return 0;
-}
-
-/*
- * clear connection security
- */
-void rxrpc_clear_conn_security(struct rxrpc_connection *conn)
-{
-	_enter("{%d}", conn->debug_id);
-
-	if (conn->security) {
-		conn->security->clear(conn);
-		rxrpc_security_put(conn->security);
-		conn->security = NULL;
-	}
-
-	key_put(conn->key);
-	key_put(conn->server_key);
-}
diff --git a/net/rxrpc/insecure.c b/net/rxrpc/insecure.c
new file mode 100644
index 0000000..e571403
--- /dev/null
+++ b/net/rxrpc/insecure.c
@@ -0,0 +1,83 @@
+/* Null security operations.
+ *
+ * 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 <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+static int none_init_connection_security(struct rxrpc_connection *conn)
+{
+	return 0;
+}
+
+static void none_prime_packet_security(struct rxrpc_connection *conn)
+{
+}
+
+static int none_secure_packet(const struct rxrpc_call *call,
+			       struct sk_buff *skb,
+			       size_t data_size,
+			       void *sechdr)
+{
+	return 0;
+}
+
+static int none_verify_packet(const struct rxrpc_call *call,
+			       struct sk_buff *skb,
+			       u32 *_abort_code)
+{
+	return 0;
+}
+
+static int none_respond_to_challenge(struct rxrpc_connection *conn,
+				      struct sk_buff *skb,
+				      u32 *_abort_code)
+{
+	*_abort_code = RX_PROTOCOL_ERROR;
+	return -EPROTO;
+}
+
+static int none_verify_response(struct rxrpc_connection *conn,
+				 struct sk_buff *skb,
+				 u32 *_abort_code)
+{
+	*_abort_code = RX_PROTOCOL_ERROR;
+	return -EPROTO;
+}
+
+static void none_clear(struct rxrpc_connection *conn)
+{
+}
+
+static int none_init(void)
+{
+	return 0;
+}
+
+static void none_exit(void)
+{
+}
+
+/*
+ * RxRPC Kerberos-based security
+ */
+const struct rxrpc_security rxrpc_no_security = {
+	.name				= "none",
+	.security_index			= RXRPC_SECURITY_NONE,
+	.init				= none_init,
+	.exit				= none_exit,
+	.init_connection_security	= none_init_connection_security,
+	.prime_packet_security		= none_prime_packet_security,
+	.secure_packet			= none_secure_packet,
+	.verify_packet			= none_verify_packet,
+	.respond_to_challenge		= none_respond_to_challenge,
+	.verify_response		= none_verify_response,
+	.clear				= none_clear,
+};
diff --git a/net/rxrpc/misc.c b/net/rxrpc/misc.c
new file mode 100644
index 0000000..1afe987
--- /dev/null
+++ b/net/rxrpc/misc.c
@@ -0,0 +1,89 @@
+/* Miscellaneous bits
+ *
+ * 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/kernel.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+/*
+ * How long to wait before scheduling ACK generation after seeing a
+ * packet with RXRPC_REQUEST_ACK set (in jiffies).
+ */
+unsigned int rxrpc_requested_ack_delay = 1;
+
+/*
+ * How long to wait before scheduling an ACK with subtype DELAY (in jiffies).
+ *
+ * We use this when we've received new data packets.  If those packets aren't
+ * all consumed within this time we will send a DELAY ACK if an ACK was not
+ * requested to let the sender know it doesn't need to resend.
+ */
+unsigned int rxrpc_soft_ack_delay = 1 * HZ;
+
+/*
+ * How long to wait before scheduling an ACK with subtype IDLE (in jiffies).
+ *
+ * We use this when we've consumed some previously soft-ACK'd packets when
+ * further packets aren't immediately received to decide when to send an IDLE
+ * ACK let the other end know that it can free up its Tx buffer space.
+ */
+unsigned int rxrpc_idle_ack_delay = 0.5 * HZ;
+
+/*
+ * Receive window size in packets.  This indicates the maximum number of
+ * unconsumed received packets we're willing to retain in memory.  Once this
+ * limit is hit, we should generate an EXCEEDS_WINDOW ACK and discard further
+ * packets.
+ */
+unsigned int rxrpc_rx_window_size = 32;
+
+/*
+ * Maximum Rx MTU size.  This indicates to the sender the size of jumbo packet
+ * made by gluing normal packets together that we're willing to handle.
+ */
+unsigned int rxrpc_rx_mtu = 5692;
+
+/*
+ * The maximum number of fragments in a received jumbo packet that we tell the
+ * sender that we're willing to handle.
+ */
+unsigned int rxrpc_rx_jumbo_max = 4;
+
+const char *const rxrpc_pkts[] = {
+	"?00",
+	"DATA", "ACK", "BUSY", "ABORT", "ACKALL", "CHALL", "RESP", "DEBUG",
+	"?09", "?10", "?11", "?12", "VERSION", "?14", "?15"
+};
+
+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,
+};
+
+const char *rxrpc_acks(u8 reason)
+{
+	static const char *const str[] = {
+		"---", "REQ", "DUP", "OOS", "WIN", "MEM", "PNG", "PNR", "DLY",
+		"IDL", "-?-"
+	};
+
+	if (reason >= ARRAY_SIZE(str))
+		reason = ARRAY_SIZE(str) - 1;
+	return str[reason];
+}
diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c
index f0aeb81..6b726a0 100644
--- a/net/rxrpc/rxkad.c
+++ b/net/rxrpc/rxkad.c
@@ -20,7 +20,6 @@
 #include <net/sock.h>
 #include <net/af_rxrpc.h>
 #include <keys/rxrpc-type.h>
-#define rxrpc_debug rxkad_debug
 #include "ar-internal.h"
 
 #define RXKAD_VERSION			2
@@ -31,10 +30,6 @@
 #define REALM_SZ			40	/* size of principal's auth domain */
 #define SNAME_SZ			40	/* size of service name */
 
-unsigned int rxrpc_debug;
-module_param_named(debug, rxrpc_debug, uint, S_IWUSR | S_IRUGO);
-MODULE_PARM_DESC(debug, "rxkad debugging mask");
-
 struct rxkad_level1_hdr {
 	__be32	data_size;	/* true data size (excluding padding) */
 };
@@ -44,10 +39,6 @@ struct rxkad_level2_hdr {
 	__be32	checksum;	/* decrypted data checksum */
 };
 
-MODULE_DESCRIPTION("RxRPC network protocol type-2 security (Kerberos 4)");
-MODULE_AUTHOR("Red Hat, Inc.");
-MODULE_LICENSE("GPL");
-
 /*
  * this holds a pinned cipher so that keventd doesn't get called by the cipher
  * alloc routine, but since we have it to hand, we use it to decrypt RESPONSE
@@ -1164,12 +1155,35 @@ static void rxkad_clear(struct rxrpc_connection *conn)
 }
 
 /*
+ * Initialise the rxkad security service.
+ */
+static int rxkad_init(void)
+{
+	/* pin the cipher we need so that the crypto layer doesn't invoke
+	 * keventd to go get it */
+	rxkad_ci = crypto_alloc_skcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(rxkad_ci))
+		return PTR_ERR(rxkad_ci);
+	return 0;
+}
+
+/*
+ * Clean up the rxkad security service.
+ */
+static void rxkad_exit(void)
+{
+	if (rxkad_ci)
+		crypto_free_skcipher(rxkad_ci);
+}
+
+/*
  * RxRPC Kerberos-based security
  */
-static struct rxrpc_security rxkad = {
-	.owner				= THIS_MODULE,
+const struct rxrpc_security rxkad = {
 	.name				= "rxkad",
 	.security_index			= RXRPC_SECURITY_RXKAD,
+	.init				= rxkad_init,
+	.exit				= rxkad_exit,
 	.init_connection_security	= rxkad_init_connection_security,
 	.prime_packet_security		= rxkad_prime_packet_security,
 	.secure_packet			= rxkad_secure_packet,
@@ -1179,28 +1193,3 @@ static struct rxrpc_security rxkad = {
 	.verify_response		= rxkad_verify_response,
 	.clear				= rxkad_clear,
 };
-
-static __init int rxkad_init(void)
-{
-	_enter("");
-
-	/* pin the cipher we need so that the crypto layer doesn't invoke
-	 * keventd to go get it */
-	rxkad_ci = crypto_alloc_skcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC);
-	if (IS_ERR(rxkad_ci))
-		return PTR_ERR(rxkad_ci);
-
-	return rxrpc_register_security(&rxkad);
-}
-
-module_init(rxkad_init);
-
-static __exit void rxkad_exit(void)
-{
-	_enter("");
-
-	rxrpc_unregister_security(&rxkad);
-	crypto_free_skcipher(rxkad_ci);
-}
-
-module_exit(rxkad_exit);