/*
* net/tipc/eth_media.c: Ethernet bearer support for TIPC
*
* Copyright (c) 2001-2006, Ericsson AB
* Copyright (c) 2005, 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 <linux/version.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) {
clone->nh.raw = clone->data;
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
*
* 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 (likely(eb_ptr->bearer)) {
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);
} else {
kfree_skb(buf);
}
} else {
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 = dev_base;
struct eth_bearer *eb_ptr = ð_bearers[0];
struct eth_bearer *stop = ð_bearers[MAX_ETH_BEARERS];
char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1;
/* Find device with specified name */
while (dev && dev->name &&
(memcmp(dev->name, driver_name, strlen(dev->name)))) {
dev = dev->next;
}
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 = __constant_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 = 0;
}
/**
* 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 = ð_bearers[0];
struct eth_bearer *stop = ð_bearers[MAX_ETH_BEARERS];
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;
if (str_size < 18)
*str_buf = '\0';
else
sprintf(str_buf, "%02x:%02x:%02x:%02x:%02x:%02x",
addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
return str_buf;
}
/**
* 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 eth_media_start(void)
{
struct tipc_media_addr bcast_addr;
int res;
if (eth_started)
return -EINVAL;
memset(&bcast_addr, 0xff, sizeof(bcast_addr));
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(¬ifier);
if (!res)
eth_started = 1;
return res;
}
/**
* eth_media_stop - deactivate Ethernet bearer support
*/
void eth_media_stop(void)
{
int i;
if (!eth_started)
return;
unregister_netdevice_notifier(¬ifier);
for (i = 0; i < MAX_ETH_BEARERS ; i++) {
if (eth_bearers[i].bearer) {
eth_bearers[i].bearer->blocked = 1;
eth_bearers[i].bearer = 0;
}
if (eth_bearers[i].dev) {
dev_remove_pack(ð_bearers[i].tipc_packet_type);
dev_put(eth_bearers[i].dev);
}
}
memset(ð_bearers, 0, sizeof(eth_bearers));
eth_started = 0;
}
