linux/net/tipc/eth_media.c
Allan Stephens e3ec9c7d5e tipc: remove zeroing assignments to static global variables
Cleans up TIPC's source code to eliminate the needless initialization
of static variables to zero.

These changes are purely cosmetic and do not alter the operation of TIPC
in any way.

Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-01 13:57:57 -08:00

323 lines
8.7 KiB
C

/*
* 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 "core.h"
#include "bearer.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;
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;
int delta;
clone = skb_clone(buf, GFP_ATOMIC);
if (!clone)
return 0;
dev = ((struct eth_bearer *)(tb_ptr->usr_handle))->dev;
delta = dev->hard_header_len - skb_headroom(buf);
if ((delta > 0) &&
pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
kfree_skb(clone);
return 0;
}
skb_reset_network_header(clone);
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 0;
}
/**
* 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).
*/
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;
if (!net_eq(dev_net(dev), &init_net)) {
kfree_skb(buf);
return 0;
}
if (likely(eb_ptr->bearer)) {
if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
buf->next = NULL;
tipc_recv_msg(buf, eb_ptr->bearer);
return 0;
}
}
kfree_skb(buf);
return 0;
}
/**
* 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;
int pending_dev = 0;
/* Find unused Ethernet bearer structure */
while (eb_ptr->dev) {
if (!eb_ptr->bearer)
pending_dev++;
if (++eb_ptr == stop)
return pending_dev ? -EAGAIN : -EDQUOT;
}
/* 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) */
while ((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 (!net_eq(dev_net(dev), &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;
if (str_size < 18)
*str_buf = '\0';
else
sprintf(str_buf, "%pM", 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;
}