linux/drivers/net/wan/lapbether.c

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/*
* "LAPB via ethernet" driver release 001
*
* This code REQUIRES 2.1.15 or higher/ NET3.038
*
* This module:
* This module 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.
*
* This is a "pseudo" network driver to allow LAPB over Ethernet.
*
* This driver can use any ethernet destination address, and can be
* limited to accept frames from one dedicated ethernet card only.
*
* History
* LAPBETH 001 Jonathan Naylor Cloned from bpqether.c
* 2000-10-29 Henner Eisen lapb_data_indication() return status.
* 2000-11-14 Henner Eisen dev_hold/put, NETDEV_GOING_DOWN support
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/net.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <asm/uaccess.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/stat.h>
#include <linux/module.h>
#include <linux/lapb.h>
#include <linux/init.h>
#include <net/x25device.h>
static const u8 bcast_addr[6] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
/* If this number is made larger, check that the temporary string buffer
* in lapbeth_new_device is large enough to store the probe device name.*/
#define MAXLAPBDEV 100
struct lapbethdev {
struct list_head node;
struct net_device *ethdev; /* link to ethernet device */
struct net_device *axdev; /* lapbeth device (lapb#) */
};
static LIST_HEAD(lapbeth_devices);
/* ------------------------------------------------------------------------ */
/*
* Get the LAPB device for the ethernet device
*/
static struct lapbethdev *lapbeth_get_x25_dev(struct net_device *dev)
{
struct lapbethdev *lapbeth;
list_for_each_entry_rcu(lapbeth, &lapbeth_devices, node) {
if (lapbeth->ethdev == dev)
return lapbeth;
}
return NULL;
}
static __inline__ int dev_is_ethdev(struct net_device *dev)
{
return dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5);
}
/* ------------------------------------------------------------------------ */
/*
* Receive a LAPB frame via an ethernet interface.
*/
static int lapbeth_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *ptype, struct net_device *orig_dev)
{
int len, err;
struct lapbethdev *lapbeth;
if (dev_net(dev) != &init_net)
goto drop;
if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
return NET_RX_DROP;
if (!pskb_may_pull(skb, 2))
goto drop;
rcu_read_lock();
lapbeth = lapbeth_get_x25_dev(dev);
if (!lapbeth)
goto drop_unlock;
if (!netif_running(lapbeth->axdev))
goto drop_unlock;
len = skb->data[0] + skb->data[1] * 256;
dev->stats.rx_packets++;
dev->stats.rx_bytes += len;
skb_pull(skb, 2); /* Remove the length bytes */
skb_trim(skb, len); /* Set the length of the data */
if ((err = lapb_data_received(lapbeth->axdev, skb)) != LAPB_OK) {
printk(KERN_DEBUG "lapbether: lapb_data_received err - %d\n", err);
goto drop_unlock;
}
out:
rcu_read_unlock();
return 0;
drop_unlock:
kfree_skb(skb);
goto out;
drop:
kfree_skb(skb);
return 0;
}
static int lapbeth_data_indication(struct net_device *dev, struct sk_buff *skb)
{
unsigned char *ptr;
skb_push(skb, 1);
if (skb_cow(skb, 1))
return NET_RX_DROP;
ptr = skb->data;
*ptr = X25_IFACE_DATA;
skb->protocol = x25_type_trans(skb, dev);
return netif_rx(skb);
}
/*
* Send a LAPB frame via an ethernet interface
*/
static netdev_tx_t lapbeth_xmit(struct sk_buff *skb,
struct net_device *dev)
{
int err;
/*
* Just to be *really* sure not to send anything if the interface
* is down, the ethernet device may have gone.
*/
if (!netif_running(dev))
goto drop;
switch (skb->data[0]) {
case X25_IFACE_DATA:
break;
case X25_IFACE_CONNECT:
if ((err = lapb_connect_request(dev)) != LAPB_OK)
pr_err("lapb_connect_request error: %d\n", err);
goto drop;
case X25_IFACE_DISCONNECT:
if ((err = lapb_disconnect_request(dev)) != LAPB_OK)
pr_err("lapb_disconnect_request err: %d\n", err);
/* Fall thru */
default:
goto drop;
}
skb_pull(skb, 1);
if ((err = lapb_data_request(dev, skb)) != LAPB_OK) {
pr_err("lapb_data_request error - %d\n", err);
goto drop;
}
out:
return NETDEV_TX_OK;
drop:
kfree_skb(skb);
goto out;
}
static void lapbeth_data_transmit(struct net_device *ndev, struct sk_buff *skb)
{
struct lapbethdev *lapbeth = netdev_priv(ndev);
unsigned char *ptr;
struct net_device *dev;
int size = skb->len;
skb->protocol = htons(ETH_P_X25);
ptr = skb_push(skb, 2);
*ptr++ = size % 256;
*ptr++ = size / 256;
ndev->stats.tx_packets++;
ndev->stats.tx_bytes += size;
skb->dev = dev = lapbeth->ethdev;
dev_hard_header(skb, dev, ETH_P_DEC, bcast_addr, NULL, 0);
dev_queue_xmit(skb);
}
static void lapbeth_connected(struct net_device *dev, int reason)
{
unsigned char *ptr;
struct sk_buff *skb = dev_alloc_skb(1);
if (!skb) {
pr_err("out of memory\n");
return;
}
ptr = skb_put(skb, 1);
*ptr = X25_IFACE_CONNECT;
skb->protocol = x25_type_trans(skb, dev);
netif_rx(skb);
}
static void lapbeth_disconnected(struct net_device *dev, int reason)
{
unsigned char *ptr;
struct sk_buff *skb = dev_alloc_skb(1);
if (!skb) {
pr_err("out of memory\n");
return;
}
ptr = skb_put(skb, 1);
*ptr = X25_IFACE_DISCONNECT;
skb->protocol = x25_type_trans(skb, dev);
netif_rx(skb);
}
/*
* Set AX.25 callsign
*/
static int lapbeth_set_mac_address(struct net_device *dev, void *addr)
{
struct sockaddr *sa = addr;
memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
return 0;
}
static const struct lapb_register_struct lapbeth_callbacks = {
.connect_confirmation = lapbeth_connected,
.connect_indication = lapbeth_connected,
.disconnect_confirmation = lapbeth_disconnected,
.disconnect_indication = lapbeth_disconnected,
.data_indication = lapbeth_data_indication,
.data_transmit = lapbeth_data_transmit,
};
/*
* open/close a device
*/
static int lapbeth_open(struct net_device *dev)
{
int err;
if ((err = lapb_register(dev, &lapbeth_callbacks)) != LAPB_OK) {
pr_err("lapb_register error: %d\n", err);
return -ENODEV;
}
netif_start_queue(dev);
return 0;
}
static int lapbeth_close(struct net_device *dev)
{
int err;
netif_stop_queue(dev);
if ((err = lapb_unregister(dev)) != LAPB_OK)
pr_err("lapb_unregister error: %d\n", err);
return 0;
}
/* ------------------------------------------------------------------------ */
static const struct net_device_ops lapbeth_netdev_ops = {
.ndo_open = lapbeth_open,
.ndo_stop = lapbeth_close,
.ndo_start_xmit = lapbeth_xmit,
.ndo_set_mac_address = lapbeth_set_mac_address,
};
static void lapbeth_setup(struct net_device *dev)
{
dev->netdev_ops = &lapbeth_netdev_ops;
dev->destructor = free_netdev;
dev->type = ARPHRD_X25;
dev->hard_header_len = 3;
dev->mtu = 1000;
dev->addr_len = 0;
}
/*
* Setup a new device.
*/
static int lapbeth_new_device(struct net_device *dev)
{
struct net_device *ndev;
struct lapbethdev *lapbeth;
int rc = -ENOMEM;
ASSERT_RTNL();
ndev = alloc_netdev(sizeof(*lapbeth), "lapb%d", NET_NAME_UNKNOWN,
lapbeth_setup);
if (!ndev)
goto out;
lapbeth = netdev_priv(ndev);
lapbeth->axdev = ndev;
dev_hold(dev);
lapbeth->ethdev = dev;
rc = -EIO;
if (register_netdevice(ndev))
goto fail;
list_add_rcu(&lapbeth->node, &lapbeth_devices);
rc = 0;
out:
return rc;
fail:
dev_put(dev);
free_netdev(ndev);
kfree(lapbeth);
goto out;
}
/*
* Free a lapb network device.
*/
static void lapbeth_free_device(struct lapbethdev *lapbeth)
{
dev_put(lapbeth->ethdev);
list_del_rcu(&lapbeth->node);
unregister_netdevice(lapbeth->axdev);
}
/*
* Handle device status changes.
*
* Called from notifier with RTNL held.
*/
static int lapbeth_device_event(struct notifier_block *this,
unsigned long event, void *ptr)
{
struct lapbethdev *lapbeth;
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
if (dev_net(dev) != &init_net)
return NOTIFY_DONE;
if (!dev_is_ethdev(dev))
return NOTIFY_DONE;
switch (event) {
case NETDEV_UP:
/* New ethernet device -> new LAPB interface */
if (lapbeth_get_x25_dev(dev) == NULL)
lapbeth_new_device(dev);
break;
case NETDEV_DOWN:
/* ethernet device closed -> close LAPB interface */
lapbeth = lapbeth_get_x25_dev(dev);
if (lapbeth)
dev_close(lapbeth->axdev);
break;
case NETDEV_UNREGISTER:
/* ethernet device disappears -> remove LAPB interface */
lapbeth = lapbeth_get_x25_dev(dev);
if (lapbeth)
lapbeth_free_device(lapbeth);
break;
}
return NOTIFY_DONE;
}
/* ------------------------------------------------------------------------ */
static struct packet_type lapbeth_packet_type __read_mostly = {
.type = cpu_to_be16(ETH_P_DEC),
.func = lapbeth_rcv,
};
static struct notifier_block lapbeth_dev_notifier = {
.notifier_call = lapbeth_device_event,
};
static const char banner[] __initconst =
KERN_INFO "LAPB Ethernet driver version 0.02\n";
static int __init lapbeth_init_driver(void)
{
dev_add_pack(&lapbeth_packet_type);
register_netdevice_notifier(&lapbeth_dev_notifier);
printk(banner);
return 0;
}
module_init(lapbeth_init_driver);
static void __exit lapbeth_cleanup_driver(void)
{
struct lapbethdev *lapbeth;
struct list_head *entry, *tmp;
dev_remove_pack(&lapbeth_packet_type);
unregister_netdevice_notifier(&lapbeth_dev_notifier);
rtnl_lock();
list_for_each_safe(entry, tmp, &lapbeth_devices) {
lapbeth = list_entry(entry, struct lapbethdev, node);
dev_put(lapbeth->ethdev);
unregister_netdevice(lapbeth->axdev);
}
rtnl_unlock();
}
module_exit(lapbeth_cleanup_driver);
MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
MODULE_DESCRIPTION("The unofficial LAPB over Ethernet driver");
MODULE_LICENSE("GPL");