af_rxrpc.c

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/* AF_RXRPC implementation
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 *
 * 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/slab.h>
#include <linux/skbuff.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>
#include <linux/key-type.h>
#include <net/net_namespace.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 int rxrpc_debug; // = RXRPC_DEBUG_KPROTO;
module_param_named(debug, rxrpc_debug, uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(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;

struct workqueue_struct *rxrpc_workqueue;

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);
    rcu_read_lock();
    if (rxrpc_writable(sk)) {
        struct socket_wq *wq = rcu_dereference(sk->sk_wq);

        if (wq_has_sleeper(wq))
            wake_up_interruptible(&wq->wait);
        sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
    }
    rcu_read_unlock();
}

/*
 * 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 @ %pI4",
               ntohs(srx->transport.sin.sin_port),
               &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,
                               gfp_t gfp)
{
    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);
    if (IS_ERR(peer))
        return ERR_CAST(peer);

    /* find a transport */
    trans = rxrpc_get_transport(rx->local, peer, gfp);
    rxrpc_put_peer(peer);
    _leave(" = %p", trans);
    return trans;
}

struct rxrpc_call *rxrpc_kernel_begin_call(struct socket *sock,
                       struct sockaddr_rxrpc *srx,
                       struct key *key,
                       unsigned long user_call_ID,
                       gfp_t gfp)
{
    struct rxrpc_conn_bundle *bundle;
    struct rxrpc_transport *trans;
    struct rxrpc_call *call;
    struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
    __be16 service_id;

    _enter(",,%x,%lx", key_serial(key), user_call_ID);

    lock_sock(&rx->sk);

    if (srx) {
        trans = rxrpc_name_to_transport(sock, (struct sockaddr *) srx,
                        sizeof(*srx), 0, gfp);
        if (IS_ERR(trans)) {
            call = ERR_CAST(trans);
            trans = NULL;
            goto out_notrans;
        }
    } else {
        trans = rx->trans;
        if (!trans) {
            call = ERR_PTR(-ENOTCONN);
            goto out_notrans;
        }
        atomic_inc(&trans->usage);
    }

    service_id = rx->service_id;
    if (srx)
        service_id = htons(srx->srx_service);

    if (!key)
        key = rx->key;
    if (key && !key->payload.data)
        key = NULL; /* a no-security key */

    bundle = rxrpc_get_bundle(rx, trans, key, service_id, gfp);
    if (IS_ERR(bundle)) {
        call = ERR_CAST(bundle);
        goto out;
    }

    call = rxrpc_get_client_call(rx, trans, bundle, user_call_ID, true,
                     gfp);
    rxrpc_put_bundle(trans, bundle);
out:
    rxrpc_put_transport(trans);
out_notrans:
    release_sock(&rx->sk);
    _leave(" = %p", call);
    return call;
}

EXPORT_SYMBOL(rxrpc_kernel_begin_call);

void rxrpc_kernel_end_call(struct rxrpc_call *call)
{
    _enter("%d{%d}", call->debug_id, atomic_read(&call->usage));
    rxrpc_remove_user_ID(call->socket, call);
    rxrpc_put_call(call);
}

EXPORT_SYMBOL(rxrpc_kernel_end_call);

void rxrpc_kernel_intercept_rx_messages(struct socket *sock,
                    rxrpc_interceptor_t interceptor)
{
    struct rxrpc_sock *rx = rxrpc_sk(sock->sk);

    _enter("");
    rx->interceptor = interceptor;
}

EXPORT_SYMBOL(rxrpc_kernel_intercept_rx_messages);

/*
 * 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,
                    GFP_KERNEL);
    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, GFP_KERNEL);
        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, unsigned int optlen)
{
    struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
    unsigned int 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 int))
                goto error;
            ret = -EISCONN;
            if (rx->sk.sk_state != RXRPC_UNCONNECTED)
                goto error;
            ret = get_user(min_sec_level,
                       (unsigned int __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;

    sock_poll_wait(file, sk_sleep(sk), 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 net *net, struct socket *sock, int protocol,
            int kern)
{
    struct rxrpc_sock *rx;
    struct sock *sk;

    _enter("%p,%d", sock, protocol);

    if (!net_eq(net, &init_net))
        return -EAFNOSUPPORT;

    /* 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(net, PF_RXRPC, GFP_KERNEL, &rxrpc_proto);
    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);

    WARN_ON(atomic_read(&sk->sk_wmem_alloc));
    WARN_ON(!sk_unhashed(sk));
    WARN_ON(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_workqueue(rxrpc_workqueue);
    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 const 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(get_seconds());

    ret = -ENOMEM;
    rxrpc_call_jar = kmem_cache_create(
        "rxrpc_call_jar", sizeof(struct rxrpc_call), 0,
        SLAB_HWCACHE_ALIGN, NULL);
    if (!rxrpc_call_jar) {
        printk(KERN_NOTICE "RxRPC: Failed to allocate call jar\n");
        goto error_call_jar;
    }

    rxrpc_workqueue = alloc_workqueue("krxrpcd", 0, 1);
    if (!rxrpc_workqueue) {
        printk(KERN_NOTICE "RxRPC: Failed to allocate work queue\n");
        goto error_work_queue;
    }

    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(&init_net, "rxrpc_calls", 0, &rxrpc_call_seq_fops);
    proc_net_fops_create(&init_net, "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:
    destroy_workqueue(rxrpc_workqueue);
error_work_queue:
    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_workqueue(rxrpc_workqueue);
    proc_net_remove(&init_net, "rxrpc_conns");
    proc_net_remove(&init_net, "rxrpc_calls");
    destroy_workqueue(rxrpc_workqueue);
    kmem_cache_destroy(rxrpc_call_jar);
    _leave("");
}

module_init(af_rxrpc_init);
module_exit(af_rxrpc_exit);