/* 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 <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 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);
        read_lock(&sk->sk_callback_lock);
        if (rxrpc_writable(sk)) {
                if (sk_has_sleeper(sk))
                        wake_up_interruptible(sk->sk_sleep);
                sk_wake_async(sk, SOCK_WAKE_SPACE, 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 @ %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;
}

/**
 * rxrpc_kernel_begin_call - Allow a kernel service to begin a call
 * @sock: The socket on which to make the call
 * @srx: The address of the peer to contact (defaults to socket setting)
 * @key: The security context to use (defaults to socket setting)
 * @user_call_ID: The ID to use
 *
 * Allow a kernel service to begin a call on the nominated socket.  This just
 * sets up all the internal tracking structures and allocates connection and
 * call IDs as appropriate.  The call to be used is returned.
 *
 * The default socket destination address and security may be overridden by
 * supplying @srx and @key.
 */
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);

/**
 * rxrpc_kernel_end_call - Allow a kernel service to end a call it was using
 * @call: The call to end
 *
 * Allow a kernel service to end a call it was using.  The call must be
 * complete before this is called (the call should be aborted if necessary).
 */
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);

/**
 * rxrpc_kernel_intercept_rx_messages - Intercept received RxRPC messages
 * @sock: The socket to intercept received messages on
 * @interceptor: The function to pass the messages to
 *
 * Allow a kernel service to intercept messages heading for the Rx queue on an
 * RxRPC socket.  They get passed to the specified function instead.
 * @interceptor should free the socket buffers it is given.  @interceptor is
 * called with the socket receive queue spinlock held and softirqs disabled -
 * this ensures that the messages will be delivered in the right order.
 */
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 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;

        sock_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 net *net, struct socket *sock, int protocol)
{
        struct rxrpc_sock *rx;
        struct sock *sk;

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

        if (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 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 = create_workqueue("krxrpcd");
        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);