linux/net/tipc/eth_media.c
Ying Xue 6798158348 tipc: correct return value of recv_msg routine
Currently, rcv_msg() always returns zero on a packet delivery upcall
from net_device.

To make its behavior more compliant with the way this API should be
used, we change this to let it return NET_RX_SUCCESS (which is zero
anyway) when it is able to handle the packet, and NET_RX_DROP otherwise.
The latter does not imply any functional change, it only enables the
driver to keep more accurate statistics about the fate of delivered
packets.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-18 13:20:43 -04:00

377 lines
11 KiB
C

/*
* net/tipc/eth_media.c: Ethernet bearer support for TIPC
*
* Copyright (c) 2001-2007, Ericsson AB
* Copyright (c) 2005-2008, 2011-2013, 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_MEDIA MAX_BEARERS
#define ETH_ADDR_OFFSET 4 /* message header offset of MAC address */
/**
* struct eth_media - 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
* @setup: work item used when enabling bearer
* @cleanup: work item used when disabling bearer
*/
struct eth_media {
struct tipc_bearer *bearer;
struct net_device *dev;
struct packet_type tipc_packet_type;
struct work_struct setup;
struct work_struct cleanup;
};
static struct tipc_media eth_media_info;
static struct eth_media eth_media_array[MAX_ETH_MEDIA];
static int eth_started;
static int recv_notification(struct notifier_block *nb, unsigned long evt,
void *dv);
/*
* Network device notifier info
*/
static struct notifier_block notifier = {
.notifier_call = recv_notification,
.priority = 0
};
/**
* eth_media_addr_set - initialize Ethernet media address structure
*
* Media-dependent "value" field stores MAC address in first 6 bytes
* and zeroes out the remaining bytes.
*/
static void eth_media_addr_set(const struct tipc_bearer *tb_ptr,
struct tipc_media_addr *a, char *mac)
{
memcpy(a->value, mac, ETH_ALEN);
memset(a->value + ETH_ALEN, 0, sizeof(a->value) - ETH_ALEN);
a->media_id = TIPC_MEDIA_TYPE_ETH;
a->broadcast = !memcmp(mac, tb_ptr->bcast_addr.value, ETH_ALEN);
}
/**
* 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_media *)(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;
clone->protocol = htons(ETH_P_TIPC);
dev_hard_header(clone, dev, ETH_P_TIPC, dest->value,
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_media *eb_ptr = (struct eth_media *)pt->af_packet_priv;
if (!net_eq(dev_net(dev), &init_net)) {
kfree_skb(buf);
return NET_RX_DROP;
}
if (likely(eb_ptr->bearer)) {
if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
buf->next = NULL;
tipc_recv_msg(buf, eb_ptr->bearer);
return NET_RX_SUCCESS;
}
}
kfree_skb(buf);
return NET_RX_DROP;
}
/**
* setup_media - setup association between Ethernet bearer and interface
*/
static void setup_media(struct work_struct *work)
{
struct eth_media *eb_ptr =
container_of(work, struct eth_media, setup);
dev_add_pack(&eb_ptr->tipc_packet_type);
}
/**
* enable_media - attach TIPC bearer to an Ethernet interface
*/
static int enable_media(struct tipc_bearer *tb_ptr)
{
struct net_device *dev;
struct eth_media *eb_ptr = &eth_media_array[0];
struct eth_media *stop = &eth_media_array[MAX_ETH_MEDIA];
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 */
dev = dev_get_by_name(&init_net, driver_name);
if (!dev)
return -ENODEV;
/* Create Ethernet bearer for device */
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));
INIT_WORK(&eb_ptr->setup, setup_media);
schedule_work(&eb_ptr->setup);
/* Associate TIPC bearer with Ethernet bearer */
eb_ptr->bearer = tb_ptr;
tb_ptr->usr_handle = (void *)eb_ptr;
memset(tb_ptr->bcast_addr.value, 0, sizeof(tb_ptr->bcast_addr.value));
memcpy(tb_ptr->bcast_addr.value, dev->broadcast, ETH_ALEN);
tb_ptr->bcast_addr.media_id = TIPC_MEDIA_TYPE_ETH;
tb_ptr->bcast_addr.broadcast = 1;
tb_ptr->mtu = dev->mtu;
tb_ptr->blocked = 0;
eth_media_addr_set(tb_ptr, &tb_ptr->addr, (char *)dev->dev_addr);
return 0;
}
/**
* cleanup_media - break association between Ethernet bearer and interface
*
* This routine must be invoked from a work queue because it can sleep.
*/
static void cleanup_media(struct work_struct *work)
{
struct eth_media *eb_ptr =
container_of(work, struct eth_media, cleanup);
dev_remove_pack(&eb_ptr->tipc_packet_type);
dev_put(eb_ptr->dev);
eb_ptr->dev = NULL;
}
/**
* disable_media - detach TIPC bearer from an Ethernet interface
*
* Mark Ethernet bearer as inactive so that incoming buffers are thrown away,
* then get worker thread to complete bearer cleanup. (Can't do cleanup
* here because cleanup code needs to sleep and caller holds spinlocks.)
*/
static void disable_media(struct tipc_bearer *tb_ptr)
{
struct eth_media *eb_ptr = (struct eth_media *)tb_ptr->usr_handle;
eb_ptr->bearer = NULL;
INIT_WORK(&eb_ptr->cleanup, cleanup_media);
schedule_work(&eb_ptr->cleanup);
}
/**
* 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 *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct eth_media *eb_ptr = &eth_media_array[0];
struct eth_media *stop = &eth_media_array[MAX_ETH_MEDIA];
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);
break;
case NETDEV_UP:
tipc_continue(eb_ptr->bearer);
break;
case NETDEV_DOWN:
tipc_block_bearer(eb_ptr->bearer);
break;
case NETDEV_CHANGEMTU:
case NETDEV_CHANGEADDR:
tipc_block_bearer(eb_ptr->bearer);
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 int eth_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size)
{
if (str_size < 18) /* 18 = strlen("aa:bb:cc:dd:ee:ff\0") */
return 1;
sprintf(str_buf, "%pM", a->value);
return 0;
}
/**
* eth_str2addr - convert Ethernet address format to message header format
*/
static int eth_addr2msg(struct tipc_media_addr *a, char *msg_area)
{
memset(msg_area, 0, TIPC_MEDIA_ADDR_SIZE);
msg_area[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_ETH;
memcpy(msg_area + ETH_ADDR_OFFSET, a->value, ETH_ALEN);
return 0;
}
/**
* eth_str2addr - convert message header address format to Ethernet format
*/
static int eth_msg2addr(const struct tipc_bearer *tb_ptr,
struct tipc_media_addr *a, char *msg_area)
{
if (msg_area[TIPC_MEDIA_TYPE_OFFSET] != TIPC_MEDIA_TYPE_ETH)
return 1;
eth_media_addr_set(tb_ptr, a, msg_area + ETH_ADDR_OFFSET);
return 0;
}
/*
* Ethernet media registration info
*/
static struct tipc_media eth_media_info = {
.send_msg = send_msg,
.enable_media = enable_media,
.disable_media = disable_media,
.addr2str = eth_addr2str,
.addr2msg = eth_addr2msg,
.msg2addr = eth_msg2addr,
.priority = TIPC_DEF_LINK_PRI,
.tolerance = TIPC_DEF_LINK_TOL,
.window = TIPC_DEF_LINK_WIN,
.type_id = TIPC_MEDIA_TYPE_ETH,
.name = "eth"
};
/**
* 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)
{
int res;
if (eth_started)
return -EINVAL;
res = tipc_register_media(&eth_media_info);
if (res)
return res;
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)
{
if (!eth_started)
return;
flush_scheduled_work();
unregister_netdevice_notifier(&notifier);
eth_started = 0;
}