Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * net/tipc/eth_media.c: Ethernet bearer support for TIPC

 *

 * Copyright (c) 2001-2007, Ericsson AB

 * Copyright (c) 2005-2007, Wind River Systems

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. Neither the names of the copyright holders nor the names of its

 *    contributors may be used to endorse or promote products derived from

 *    this software without specific prior written permission.

 *

 * Alternatively, this software may be distributed under the terms of the

 * GNU General Public License ("GPL") version 2 as published by the Free

 * Software Foundation.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

 * POSSIBILITY OF SUCH DAMAGE.

 */

#include <net/tipc/tipc.h>

#include <net/tipc/tipc_bearer.h>

#include <net/tipc/tipc_msg.h>

#include <linux/netdevice.h>

#include <net/net_namespace.h>

#define MAX_ETH_BEARERS         2

#define ETH_LINK_PRIORITY       TIPC_DEF_LINK_PRI

#define ETH_LINK_TOLERANCE      TIPC_DEF_LINK_TOL

#define ETH_LINK_WINDOW         TIPC_DEF_LINK_WIN

/**

 * struct eth_bearer - Ethernet bearer data structure

 * @bearer: ptr to associated "generic" bearer structure

 * @dev: ptr to associated Ethernet network device

 * @tipc_packet_type: used in binding TIPC to Ethernet driver

 */

struct eth_bearer {

        struct tipc_bearer *bearer;

        struct net_device *dev;

        struct packet_type tipc_packet_type;

};

static struct eth_bearer eth_bearers[MAX_ETH_BEARERS];

static int eth_started = 0;

static struct notifier_block notifier;

/**

 * send_msg - send a TIPC message out over an Ethernet interface

 */

static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr,

                    struct tipc_media_addr *dest)

{

        struct sk_buff *clone;

        struct net_device *dev;

        clone = skb_clone(buf, GFP_ATOMIC);

        if (clone) {

                skb_reset_network_header(clone);

                dev = ((struct eth_bearer *)(tb_ptr->usr_handle))->dev;

                clone->dev = dev;

                dev_hard_header(clone, dev, ETH_P_TIPC,

                                 &dest->dev_addr.eth_addr,

                                 dev->dev_addr, clone->len);

                dev_queue_xmit(clone);

        }

        return TIPC_OK;

}

/**

 * recv_msg - handle incoming TIPC message from an Ethernet interface

 *

 * Accept only packets explicitly sent to this node, or broadcast packets;

 * ignores packets sent using Ethernet multicast, and traffic sent to other

 * nodes (which can happen if interface is running in promiscuous mode).

 * Routine truncates any Ethernet padding/CRC appended to the message,

 * and ensures message size matches actual length

 */

static int recv_msg(struct sk_buff *buf, struct net_device *dev,

                    struct packet_type *pt, struct net_device *orig_dev)

{

        struct eth_bearer *eb_ptr = (struct eth_bearer *)pt->af_packet_priv;

        u32 size;

        if (dev->nd_net != &init_net) {

                kfree_skb(buf);

                return 0;

        }

        if (likely(eb_ptr->bearer)) {

                if (likely(buf->pkt_type <= PACKET_BROADCAST)) {

                        size = msg_size((struct tipc_msg *)buf->data);

                        skb_trim(buf, size);

                        if (likely(buf->len == size)) {

                                buf->next = NULL;

                                tipc_recv_msg(buf, eb_ptr->bearer);

                                return TIPC_OK;

                        }

                }

        }

        kfree_skb(buf);

        return TIPC_OK;

}

/**

 * enable_bearer - attach TIPC bearer to an Ethernet interface

 */

static int enable_bearer(struct tipc_bearer *tb_ptr)

{

        struct net_device *dev = NULL;

        struct net_device *pdev = NULL;

        struct eth_bearer *eb_ptr = &eth_bearers[0];

        struct eth_bearer *stop = &eth_bearers[MAX_ETH_BEARERS];

        char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1;

        /* Find device with specified name */

        for_each_netdev(&init_net, pdev){

                if (!strncmp(pdev->name, driver_name, IFNAMSIZ)) {

                        dev = pdev;

                        break;

                }

        }

        if (!dev)

                return -ENODEV;

        /* Find Ethernet bearer for device (or create one) */

        for (;(eb_ptr != stop) && eb_ptr->dev && (eb_ptr->dev != dev); eb_ptr++);

        if (eb_ptr == stop)

                return -EDQUOT;

        if (!eb_ptr->dev) {

                eb_ptr->dev = dev;

                eb_ptr->tipc_packet_type.type = htons(ETH_P_TIPC);

                eb_ptr->tipc_packet_type.dev = dev;

                eb_ptr->tipc_packet_type.func = recv_msg;

                eb_ptr->tipc_packet_type.af_packet_priv = eb_ptr;

                INIT_LIST_HEAD(&(eb_ptr->tipc_packet_type.list));

                dev_hold(dev);

                dev_add_pack(&eb_ptr->tipc_packet_type);

        }

        /* Associate TIPC bearer with Ethernet bearer */

        eb_ptr->bearer = tb_ptr;

        tb_ptr->usr_handle = (void *)eb_ptr;

        tb_ptr->mtu = dev->mtu;

        tb_ptr->blocked = 0;

        tb_ptr->addr.type = htonl(TIPC_MEDIA_TYPE_ETH);

        memcpy(&tb_ptr->addr.dev_addr, &dev->dev_addr, ETH_ALEN);

        return 0;

}

/**

 * disable_bearer - detach TIPC bearer from an Ethernet interface

 *

 * We really should do dev_remove_pack() here, but this function can not be

 * called at tasklet level. => Use eth_bearer->bearer as a flag to throw away

 * incoming buffers, & postpone dev_remove_pack() to eth_media_stop() on exit.

 */

static void disable_bearer(struct tipc_bearer *tb_ptr)

{

        ((struct eth_bearer *)tb_ptr->usr_handle)->bearer = NULL;

}

/**

 * recv_notification - handle device updates from OS

 *

 * Change the state of the Ethernet bearer (if any) associated with the

 * specified device.

 */

static int recv_notification(struct notifier_block *nb, unsigned long evt,

                             void *dv)

{

        struct net_device *dev = (struct net_device *)dv;

        struct eth_bearer *eb_ptr = &eth_bearers[0];

        struct eth_bearer *stop = &eth_bearers[MAX_ETH_BEARERS];

        if (dev->nd_net != &init_net)

                return NOTIFY_DONE;

        while ((eb_ptr->dev != dev)) {

                if (++eb_ptr == stop)

                        return NOTIFY_DONE;     /* couldn't find device */

        }

        if (!eb_ptr->bearer)

                return NOTIFY_DONE;             /* bearer had been disabled */

        eb_ptr->bearer->mtu = dev->mtu;

        switch (evt) {

        case NETDEV_CHANGE:

                if (netif_carrier_ok(dev))

                        tipc_continue(eb_ptr->bearer);

                else

                        tipc_block_bearer(eb_ptr->bearer->name);

                break;

        case NETDEV_UP:

                tipc_continue(eb_ptr->bearer);

                break;

        case NETDEV_DOWN:

                tipc_block_bearer(eb_ptr->bearer->name);

                break;

        case NETDEV_CHANGEMTU:

        case NETDEV_CHANGEADDR:

                tipc_block_bearer(eb_ptr->bearer->name);

                tipc_continue(eb_ptr->bearer);

                break;

        case NETDEV_UNREGISTER:

        case NETDEV_CHANGENAME:

                tipc_disable_bearer(eb_ptr->bearer->name);

                break;

        }

        return NOTIFY_OK;

}

/**

 * eth_addr2str - convert Ethernet address to string

 */

static char *eth_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size)

{

        unchar *addr = (unchar *)&a->dev_addr;

        DECLARE_MAC_BUF(mac);

        if (str_size < 18)

                *str_buf = '\0';

        else

                sprintf(str_buf, "%s", print_mac(mac, addr));

        return str_buf;

}

/**

 * tipc_eth_media_start - activate Ethernet bearer support

 *

 * Register Ethernet media type with TIPC bearer code.  Also register

 * with OS for notifications about device state changes.

 */

int tipc_eth_media_start(void)

{

        struct tipc_media_addr bcast_addr;

        int res;

        if (eth_started)

                return -EINVAL;

        bcast_addr.type = htonl(TIPC_MEDIA_TYPE_ETH);

        memset(&bcast_addr.dev_addr, 0xff, ETH_ALEN);

        memset(eth_bearers, 0, sizeof(eth_bearers));

        res = tipc_register_media(TIPC_MEDIA_TYPE_ETH, "eth",

                                  enable_bearer, disable_bearer, send_msg,

                                  eth_addr2str, &bcast_addr, ETH_LINK_PRIORITY,

                                  ETH_LINK_TOLERANCE, ETH_LINK_WINDOW);

        if (res)

                return res;

        notifier.notifier_call = &recv_notification;

        notifier.priority = 0;

        res = register_netdevice_notifier(&notifier);

        if (!res)

                eth_started = 1;

        return res;

}

/**

 * tipc_eth_media_stop - deactivate Ethernet bearer support

 */

void tipc_eth_media_stop(void)

{

        int i;

        if (!eth_started)

                return;

        unregister_netdevice_notifier(&notifier);

        for (i = 0; i < MAX_ETH_BEARERS ; i++) {

                if (eth_bearers[i].bearer) {

                        eth_bearers[i].bearer->blocked = 1;

                        eth_bearers[i].bearer = NULL;

                }

                if (eth_bearers[i].dev) {

                        dev_remove_pack(&eth_bearers[i].tipc_packet_type);

                        dev_put(eth_bearers[i].dev);

                }

        }

        memset(&eth_bearers, 0, sizeof(eth_bearers));

        eth_started = 0;

}