[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both

Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve
answers to AFS clients.  KerberosIV security is fully supported.  The patches
and some example test programs can be found in:

	http://people.redhat.com/~dhowells/rxrpc/

This will eventually replace the old implementation of kernel-only RxRPC
currently resident in net/rxrpc/.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 754 insertions, 0 deletions

diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
new file mode 100644
index 000000000000..bfa8822e2286
--- /dev/null
+++ b/net/rxrpc/af_rxrpc.c
@@ -0,0 +1,754 @@
+/* AF_RXRPC implementation
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+MODULE_DESCRIPTION("RxRPC network protocol");
+MODULE_AUTHOR("Red Hat, Inc.");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NETPROTO(PF_RXRPC);
+
+unsigned rxrpc_debug; // = RXRPC_DEBUG_KPROTO;
+module_param_named(debug, rxrpc_debug, uint, S_IWUSR | S_IRUGO);
+MODULE_PARM_DESC(rxrpc_debug, "RxRPC debugging mask");
+
+static int sysctl_rxrpc_max_qlen __read_mostly = 10;
+
+static struct proto rxrpc_proto;
+static const struct proto_ops rxrpc_rpc_ops;
+
+/* local epoch for detecting local-end reset */
+__be32 rxrpc_epoch;
+
+/* current debugging ID */
+atomic_t rxrpc_debug_id;
+
+/* count of skbs currently in use */
+atomic_t rxrpc_n_skbs;
+
+static void rxrpc_sock_destructor(struct sock *);
+
+/*
+ * see if an RxRPC socket is currently writable
+ */
+static inline int rxrpc_writable(struct sock *sk)
+{
+        return atomic_read(&sk->sk_wmem_alloc) < (size_t) sk->sk_sndbuf;
+}
+
+/*
+ * wait for write bufferage to become available
+ */
+static void rxrpc_write_space(struct sock *sk)
+{
+        _enter("%p", sk);
+        read_lock(&sk->sk_callback_lock);
+        if (rxrpc_writable(sk)) {
+                if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
+                        wake_up_interruptible(sk->sk_sleep);
+                sk_wake_async(sk, 2, POLL_OUT);
+        }
+        read_unlock(&sk->sk_callback_lock);
+}
+
+/*
+ * validate an RxRPC address
+ */
+static int rxrpc_validate_address(struct rxrpc_sock *rx,
+                                  struct sockaddr_rxrpc *srx,
+                                  int len)
+{
+        if (len < sizeof(struct sockaddr_rxrpc))
+                return -EINVAL;
+
+        if (srx->srx_family != AF_RXRPC)
+                return -EAFNOSUPPORT;
+
+        if (srx->transport_type != SOCK_DGRAM)
+                return -ESOCKTNOSUPPORT;
+
+        len -= offsetof(struct sockaddr_rxrpc, transport);
+        if (srx->transport_len < sizeof(sa_family_t) ||
+            srx->transport_len > len)
+                return -EINVAL;
+
+        if (srx->transport.family != rx->proto)
+                return -EAFNOSUPPORT;
+
+        switch (srx->transport.family) {
+        case AF_INET:
+                _debug("INET: %x @ %u.%u.%u.%u",
+                       ntohs(srx->transport.sin.sin_port),
+                       NIPQUAD(srx->transport.sin.sin_addr));
+                if (srx->transport_len > 8)
+                        memset((void *)&srx->transport + 8, 0,
+                               srx->transport_len - 8);
+                break;
+
+        case AF_INET6:
+        default:
+                return -EAFNOSUPPORT;
+        }
+
+        return 0;
+}
+
+/*
+ * bind a local address to an RxRPC socket
+ */
+static int rxrpc_bind(struct socket *sock, struct sockaddr *saddr, int len)
+{
+        struct sockaddr_rxrpc *srx = (struct sockaddr_rxrpc *) saddr;
+        struct sock *sk = sock->sk;
+        struct rxrpc_local *local;
+        struct rxrpc_sock *rx = rxrpc_sk(sk), *prx;
+        __be16 service_id;
+        int ret;
+
+        _enter("%p,%p,%d", rx, saddr, len);
+
+        ret = rxrpc_validate_address(rx, srx, len);
+        if (ret < 0)
+                goto error;
+
+        lock_sock(&rx->sk);
+
+        if (rx->sk.sk_state != RXRPC_UNCONNECTED) {
+                ret = -EINVAL;
+                goto error_unlock;
+        }
+
+        memcpy(&rx->srx, srx, sizeof(rx->srx));
+
+        /* find a local transport endpoint if we don't have one already */
+        local = rxrpc_lookup_local(&rx->srx);
+        if (IS_ERR(local)) {
+                ret = PTR_ERR(local);
+                goto error_unlock;
+        }
+
+        rx->local = local;
+        if (srx->srx_service) {
+                service_id = htons(srx->srx_service);
+                write_lock_bh(&local->services_lock);
+                list_for_each_entry(prx, &local->services, listen_link) {
+                        if (prx->service_id == service_id)
+                                goto service_in_use;
+                }
+
+                rx->service_id = service_id;
+                list_add_tail(&rx->listen_link, &local->services);
+                write_unlock_bh(&local->services_lock);
+
+                rx->sk.sk_state = RXRPC_SERVER_BOUND;
+        } else {
+                rx->sk.sk_state = RXRPC_CLIENT_BOUND;
+        }
+
+        release_sock(&rx->sk);
+        _leave(" = 0");
+        return 0;
+
+service_in_use:
+        ret = -EADDRINUSE;
+        write_unlock_bh(&local->services_lock);
+error_unlock:
+        release_sock(&rx->sk);
+error:
+        _leave(" = %d", ret);
+        return ret;
+}
+
+/*
+ * set the number of pending calls permitted on a listening socket
+ */
+static int rxrpc_listen(struct socket *sock, int backlog)
+{
+        struct sock *sk = sock->sk;
+        struct rxrpc_sock *rx = rxrpc_sk(sk);
+        int ret;
+
+        _enter("%p,%d", rx, backlog);
+
+        lock_sock(&rx->sk);
+
+        switch (rx->sk.sk_state) {
+        case RXRPC_UNCONNECTED:
+                ret = -EADDRNOTAVAIL;
+                break;
+        case RXRPC_CLIENT_BOUND:
+        case RXRPC_CLIENT_CONNECTED:
+        default:
+                ret = -EBUSY;
+                break;
+        case RXRPC_SERVER_BOUND:
+                ASSERT(rx->local != NULL);
+                sk->sk_max_ack_backlog = backlog;
+                rx->sk.sk_state = RXRPC_SERVER_LISTENING;
+                ret = 0;
+                break;
+        }
+
+        release_sock(&rx->sk);
+        _leave(" = %d", ret);
+        return ret;
+}
+
+/*
+ * find a transport by address
+ */
+static struct rxrpc_transport *rxrpc_name_to_transport(struct socket *sock,
+                                                       struct sockaddr *addr,
+                                                       int addr_len, int flags)
+{
+        struct sockaddr_rxrpc *srx = (struct sockaddr_rxrpc *) addr;
+        struct rxrpc_transport *trans;
+        struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+        struct rxrpc_peer *peer;
+
+        _enter("%p,%p,%d,%d", rx, addr, addr_len, flags);
+
+        ASSERT(rx->local != NULL);
+        ASSERT(rx->sk.sk_state > RXRPC_UNCONNECTED);
+
+        if (rx->srx.transport_type != srx->transport_type)
+                return ERR_PTR(-ESOCKTNOSUPPORT);
+        if (rx->srx.transport.family != srx->transport.family)
+                return ERR_PTR(-EAFNOSUPPORT);
+
+        /* find a remote transport endpoint from the local one */
+        peer = rxrpc_get_peer(srx, GFP_KERNEL);
+        if (IS_ERR(peer))
+                return ERR_PTR(PTR_ERR(peer));
+
+        /* find a transport */
+        trans = rxrpc_get_transport(rx->local, peer, GFP_KERNEL);
+        rxrpc_put_peer(peer);
+        _leave(" = %p", trans);
+        return trans;
+}
+
+/*
+ * connect an RxRPC socket
+ * - this just targets it at a specific destination; no actual connection
+ *   negotiation takes place
+ */
+static int rxrpc_connect(struct socket *sock, struct sockaddr *addr,
+                         int addr_len, int flags)
+{
+        struct sockaddr_rxrpc *srx = (struct sockaddr_rxrpc *) addr;
+        struct sock *sk = sock->sk;
+        struct rxrpc_transport *trans;
+        struct rxrpc_local *local;
+        struct rxrpc_sock *rx = rxrpc_sk(sk);
+        int ret;
+
+        _enter("%p,%p,%d,%d", rx, addr, addr_len, flags);
+
+        ret = rxrpc_validate_address(rx, srx, addr_len);
+        if (ret < 0) {
+                _leave(" = %d [bad addr]", ret);
+                return ret;
+        }
+
+        lock_sock(&rx->sk);
+
+        switch (rx->sk.sk_state) {
+        case RXRPC_UNCONNECTED:
+                /* find a local transport endpoint if we don't have one already */
+                ASSERTCMP(rx->local, ==, NULL);
+                rx->srx.srx_family = AF_RXRPC;
+                rx->srx.srx_service = 0;
+                rx->srx.transport_type = srx->transport_type;
+                rx->srx.transport_len = sizeof(sa_family_t);
+                rx->srx.transport.family = srx->transport.family;
+                local = rxrpc_lookup_local(&rx->srx);
+                if (IS_ERR(local)) {
+                        release_sock(&rx->sk);
+                        return PTR_ERR(local);
+                }
+                rx->local = local;
+                rx->sk.sk_state = RXRPC_CLIENT_BOUND;
+        case RXRPC_CLIENT_BOUND:
+                break;
+        case RXRPC_CLIENT_CONNECTED:
+                release_sock(&rx->sk);
+                return -EISCONN;
+        default:
+                release_sock(&rx->sk);
+                return -EBUSY; /* server sockets can't connect as well */
+        }
+
+        trans = rxrpc_name_to_transport(sock, addr, addr_len, flags);
+        if (IS_ERR(trans)) {
+                release_sock(&rx->sk);
+                _leave(" = %ld", PTR_ERR(trans));
+                return PTR_ERR(trans);
+        }
+
+        rx->trans = trans;
+        rx->service_id = htons(srx->srx_service);
+        rx->sk.sk_state = RXRPC_CLIENT_CONNECTED;
+
+        release_sock(&rx->sk);
+        return 0;
+}
+
+/*
+ * send a message through an RxRPC socket
+ * - in a client this does a number of things:
+ *   - finds/sets up a connection for the security specified (if any)
+ *   - initiates a call (ID in control data)
+ *   - ends the request phase of a call (if MSG_MORE is not set)
+ *   - sends a call data packet
+ *   - may send an abort (abort code in control data)
+ */
+static int rxrpc_sendmsg(struct kiocb *iocb, struct socket *sock,
+                         struct msghdr *m, size_t len)
+{
+        struct rxrpc_transport *trans;
+        struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+        int ret;
+
+        _enter(",{%d},,%zu", rx->sk.sk_state, len);
+
+        if (m->msg_flags & MSG_OOB)
+                return -EOPNOTSUPP;
+
+        if (m->msg_name) {
+                ret = rxrpc_validate_address(rx, m->msg_name, m->msg_namelen);
+                if (ret < 0) {
+                        _leave(" = %d [bad addr]", ret);
+                        return ret;
+                }
+        }
+
+        trans = NULL;
+        lock_sock(&rx->sk);
+
+        if (m->msg_name) {
+                ret = -EISCONN;
+                trans = rxrpc_name_to_transport(sock, m->msg_name,
+                                                m->msg_namelen, 0);
+                if (IS_ERR(trans)) {
+                        ret = PTR_ERR(trans);
+                        trans = NULL;
+                        goto out;
+                }
+        } else {
+                trans = rx->trans;
+                if (trans)
+                        atomic_inc(&trans->usage);
+        }
+
+        switch (rx->sk.sk_state) {
+        case RXRPC_SERVER_LISTENING:
+                if (!m->msg_name) {
+                        ret = rxrpc_server_sendmsg(iocb, rx, m, len);
+                        break;
+                }
+        case RXRPC_SERVER_BOUND:
+        case RXRPC_CLIENT_BOUND:
+                if (!m->msg_name) {
+                        ret = -ENOTCONN;
+                        break;
+                }
+        case RXRPC_CLIENT_CONNECTED:
+                ret = rxrpc_client_sendmsg(iocb, rx, trans, m, len);
+                break;
+        default:
+                ret = -ENOTCONN;
+                break;
+        }
+
+out:
+        release_sock(&rx->sk);
+        if (trans)
+                rxrpc_put_transport(trans);
+        _leave(" = %d", ret);
+        return ret;
+}
+
+/*
+ * set RxRPC socket options
+ */
+static int rxrpc_setsockopt(struct socket *sock, int level, int optname,
+                            char __user *optval, int optlen)
+{
+        struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+        unsigned min_sec_level;
+        int ret;
+
+        _enter(",%d,%d,,%d", level, optname, optlen);
+
+        lock_sock(&rx->sk);
+        ret = -EOPNOTSUPP;
+
+        if (level == SOL_RXRPC) {
+                switch (optname) {
+                case RXRPC_EXCLUSIVE_CONNECTION:
+                        ret = -EINVAL;
+                        if (optlen != 0)
+                                goto error;
+                        ret = -EISCONN;
+                        if (rx->sk.sk_state != RXRPC_UNCONNECTED)
+                                goto error;
+                        set_bit(RXRPC_SOCK_EXCLUSIVE_CONN, &rx->flags);
+                        goto success;
+
+                case RXRPC_SECURITY_KEY:
+                        ret = -EINVAL;
+                        if (rx->key)
+                                goto error;
+                        ret = -EISCONN;
+                        if (rx->sk.sk_state != RXRPC_UNCONNECTED)
+                                goto error;
+                        ret = rxrpc_request_key(rx, optval, optlen);
+                        goto error;
+
+                case RXRPC_SECURITY_KEYRING:
+                        ret = -EINVAL;
+                        if (rx->key)
+                                goto error;
+                        ret = -EISCONN;
+                        if (rx->sk.sk_state != RXRPC_UNCONNECTED)
+                                goto error;
+                        ret = rxrpc_server_keyring(rx, optval, optlen);
+                        goto error;
+
+                case RXRPC_MIN_SECURITY_LEVEL:
+                        ret = -EINVAL;
+                        if (optlen != sizeof(unsigned))
+                                goto error;
+                        ret = -EISCONN;
+                        if (rx->sk.sk_state != RXRPC_UNCONNECTED)
+                                goto error;
+                        ret = get_user(min_sec_level,
+                                       (unsigned __user *) optval);
+                        if (ret < 0)
+                                goto error;
+                        ret = -EINVAL;
+                        if (min_sec_level > RXRPC_SECURITY_MAX)
+                                goto error;
+                        rx->min_sec_level = min_sec_level;
+                        goto success;
+
+                default:
+                        break;
+                }
+        }
+
+success:
+        ret = 0;
+error:
+        release_sock(&rx->sk);
+        return ret;
+}
+
+/*
+ * permit an RxRPC socket to be polled
+ */
+static unsigned int rxrpc_poll(struct file *file, struct socket *sock,
+                               poll_table *wait)
+{
+        unsigned int mask;
+        struct sock *sk = sock->sk;
+
+        poll_wait(file, sk->sk_sleep, wait);
+        mask = 0;
+
+        /* the socket is readable if there are any messages waiting on the Rx
+         * queue */
+        if (!skb_queue_empty(&sk->sk_receive_queue))
+                mask |= POLLIN | POLLRDNORM;
+
+        /* the socket is writable if there is space to add new data to the
+         * socket; there is no guarantee that any particular call in progress
+         * on the socket may have space in the Tx ACK window */
+        if (rxrpc_writable(sk))
+                mask |= POLLOUT | POLLWRNORM;
+
+        return mask;
+}
+
+/*
+ * create an RxRPC socket
+ */
+static int rxrpc_create(struct socket *sock, int protocol)
+{
+        struct rxrpc_sock *rx;
+        struct sock *sk;
+
+        _enter("%p,%d", sock, protocol);
+
+        /* we support transport protocol UDP only */
+        if (protocol != PF_INET)
+                return -EPROTONOSUPPORT;
+
+        if (sock->type != SOCK_DGRAM)
+                return -ESOCKTNOSUPPORT;
+
+        sock->ops = &rxrpc_rpc_ops;
+        sock->state = SS_UNCONNECTED;
+
+        sk = sk_alloc(PF_RXRPC, GFP_KERNEL, &rxrpc_proto, 1);
+        if (!sk)
+                return -ENOMEM;
+
+        sock_init_data(sock, sk);
+        sk->sk_state            = RXRPC_UNCONNECTED;
+        sk->sk_write_space      = rxrpc_write_space;
+        sk->sk_max_ack_backlog  = sysctl_rxrpc_max_qlen;
+        sk->sk_destruct         = rxrpc_sock_destructor;
+
+        rx = rxrpc_sk(sk);
+        rx->proto = protocol;
+        rx->calls = RB_ROOT;
+
+        INIT_LIST_HEAD(&rx->listen_link);
+        INIT_LIST_HEAD(&rx->secureq);
+        INIT_LIST_HEAD(&rx->acceptq);
+        rwlock_init(&rx->call_lock);
+        memset(&rx->srx, 0, sizeof(rx->srx));
+
+        _leave(" = 0 [%p]", rx);
+        return 0;
+}
+
+/*
+ * RxRPC socket destructor
+ */
+static void rxrpc_sock_destructor(struct sock *sk)
+{
+        _enter("%p", sk);
+
+        rxrpc_purge_queue(&sk->sk_receive_queue);
+
+        BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
+        BUG_TRAP(sk_unhashed(sk));
+        BUG_TRAP(!sk->sk_socket);
+
+        if (!sock_flag(sk, SOCK_DEAD)) {
+                printk("Attempt to release alive rxrpc socket: %p\n", sk);
+                return;
+        }
+}
+
+/*
+ * release an RxRPC socket
+ */
+static int rxrpc_release_sock(struct sock *sk)
+{
+        struct rxrpc_sock *rx = rxrpc_sk(sk);
+
+        _enter("%p{%d,%d}", sk, sk->sk_state, atomic_read(&sk->sk_refcnt));
+
+        /* declare the socket closed for business */
+        sock_orphan(sk);
+        sk->sk_shutdown = SHUTDOWN_MASK;
+
+        spin_lock_bh(&sk->sk_receive_queue.lock);
+        sk->sk_state = RXRPC_CLOSE;
+        spin_unlock_bh(&sk->sk_receive_queue.lock);
+
+        ASSERTCMP(rx->listen_link.next, !=, LIST_POISON1);
+
+        if (!list_empty(&rx->listen_link)) {
+                write_lock_bh(&rx->local->services_lock);
+                list_del(&rx->listen_link);
+                write_unlock_bh(&rx->local->services_lock);
+        }
+
+        /* try to flush out this socket */
+        rxrpc_release_calls_on_socket(rx);
+        flush_scheduled_work();
+        rxrpc_purge_queue(&sk->sk_receive_queue);
+
+        if (rx->conn) {
+                rxrpc_put_connection(rx->conn);
+                rx->conn = NULL;
+        }
+
+        if (rx->bundle) {
+                rxrpc_put_bundle(rx->trans, rx->bundle);
+                rx->bundle = NULL;
+        }
+        if (rx->trans) {
+                rxrpc_put_transport(rx->trans);
+                rx->trans = NULL;
+        }
+        if (rx->local) {
+                rxrpc_put_local(rx->local);
+                rx->local = NULL;
+        }
+
+        key_put(rx->key);
+        rx->key = NULL;
+        key_put(rx->securities);
+        rx->securities = NULL;
+        sock_put(sk);
+
+        _leave(" = 0");
+        return 0;
+}
+
+/*
+ * release an RxRPC BSD socket on close() or equivalent
+ */
+static int rxrpc_release(struct socket *sock)
+{
+        struct sock *sk = sock->sk;
+
+        _enter("%p{%p}", sock, sk);
+
+        if (!sk)
+                return 0;
+
+        sock->sk = NULL;
+
+        return rxrpc_release_sock(sk);
+}
+
+/*
+ * RxRPC network protocol
+ */
+static const struct proto_ops rxrpc_rpc_ops = {
+        .family         = PF_UNIX,
+        .owner          = THIS_MODULE,
+        .release        = rxrpc_release,
+        .bind           = rxrpc_bind,
+        .connect        = rxrpc_connect,
+        .socketpair     = sock_no_socketpair,
+        .accept         = sock_no_accept,
+        .getname        = sock_no_getname,
+        .poll           = rxrpc_poll,
+        .ioctl          = sock_no_ioctl,
+        .listen         = rxrpc_listen,
+        .shutdown       = sock_no_shutdown,
+        .setsockopt     = rxrpc_setsockopt,
+        .getsockopt     = sock_no_getsockopt,
+        .sendmsg        = rxrpc_sendmsg,
+        .recvmsg        = rxrpc_recvmsg,
+        .mmap           = sock_no_mmap,
+        .sendpage       = sock_no_sendpage,
+};
+
+static struct proto rxrpc_proto = {
+        .name           = "RXRPC",
+        .owner          = THIS_MODULE,
+        .obj_size       = sizeof(struct rxrpc_sock),
+        .max_header     = sizeof(struct rxrpc_header),
+};
+
+static struct net_proto_family rxrpc_family_ops = {
+        .family = PF_RXRPC,
+        .create = rxrpc_create,
+        .owner  = THIS_MODULE,
+};
+
+/*
+ * initialise and register the RxRPC protocol
+ */
+static int __init af_rxrpc_init(void)
+{
+        struct sk_buff *dummy_skb;
+        int ret = -1;
+
+        BUILD_BUG_ON(sizeof(struct rxrpc_skb_priv) > sizeof(dummy_skb->cb));
+
+        rxrpc_epoch = htonl(xtime.tv_sec);
+
+        rxrpc_call_jar = kmem_cache_create(
+                "rxrpc_call_jar", sizeof(struct rxrpc_call), 0,
+                SLAB_HWCACHE_ALIGN, NULL, NULL);
+        if (!rxrpc_call_jar) {
+                printk(KERN_NOTICE "RxRPC: Failed to allocate call jar\n");
+                ret = -ENOMEM;
+                goto error_call_jar;
+        }
+
+        ret = proto_register(&rxrpc_proto, 1);
+        if (ret < 0) {
+                printk(KERN_CRIT "RxRPC: Cannot register protocol\n");
+                goto error_proto;
+        }
+
+        ret = sock_register(&rxrpc_family_ops);
+        if (ret < 0) {
+                printk(KERN_CRIT "RxRPC: Cannot register socket family\n");
+                goto error_sock;
+        }
+
+        ret = register_key_type(&key_type_rxrpc);
+        if (ret < 0) {
+                printk(KERN_CRIT "RxRPC: Cannot register client key type\n");
+                goto error_key_type;
+        }
+
+        ret = register_key_type(&key_type_rxrpc_s);
+        if (ret < 0) {
+                printk(KERN_CRIT "RxRPC: Cannot register server key type\n");
+                goto error_key_type_s;
+        }
+
+#ifdef CONFIG_PROC_FS
+        proc_net_fops_create("rxrpc_calls", 0, &rxrpc_call_seq_fops);
+        proc_net_fops_create("rxrpc_conns", 0, &rxrpc_connection_seq_fops);
+#endif
+        return 0;
+
+error_key_type_s:
+        unregister_key_type(&key_type_rxrpc);
+error_key_type:
+        sock_unregister(PF_RXRPC);
+error_sock:
+        proto_unregister(&rxrpc_proto);
+error_proto:
+        kmem_cache_destroy(rxrpc_call_jar);
+error_call_jar:
+        return ret;
+}
+
+/*
+ * unregister the RxRPC protocol
+ */
+static void __exit af_rxrpc_exit(void)
+{
+        _enter("");
+        unregister_key_type(&key_type_rxrpc_s);
+        unregister_key_type(&key_type_rxrpc);
+        sock_unregister(PF_RXRPC);
+        proto_unregister(&rxrpc_proto);
+        rxrpc_destroy_all_calls();
+        rxrpc_destroy_all_connections();
+        rxrpc_destroy_all_transports();
+        rxrpc_destroy_all_peers();
+        rxrpc_destroy_all_locals();
+
+        ASSERTCMP(atomic_read(&rxrpc_n_skbs), ==, 0);
+
+        _debug("flush scheduled work");
+        flush_scheduled_work();
+        proc_net_remove("rxrpc_conns");
+        proc_net_remove("rxrpc_calls");
+        kmem_cache_destroy(rxrpc_call_jar);
+        _leave("");
+}
+
+module_init(af_rxrpc_init);
+module_exit(af_rxrpc_exit);