original development tree for Linux kernel GTP module; now long in mainline.
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linux-gtp/net/phonet/pn_dev.c

452 lines
10 KiB

/*
* File: pn_dev.c
*
* Phonet network device
*
* Copyright (C) 2008 Nokia Corporation.
*
* Contact: Remi Denis-Courmont <remi.denis-courmont@nokia.com>
* Original author: Sakari Ailus <sakari.ailus@nokia.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*/
#include <linux/kernel.h>
#include <linux/net.h>
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/phonet.h>
#include <linux/proc_fs.h>
#include <linux/if_arp.h>
#include <net/sock.h>
#include <net/netns/generic.h>
#include <net/phonet/pn_dev.h>
struct phonet_routes {
struct mutex lock;
struct net_device *table[64];
};
struct phonet_net {
struct phonet_device_list pndevs;
struct phonet_routes routes;
};
int phonet_net_id __read_mostly;
static struct phonet_net *phonet_pernet(struct net *net)
{
BUG_ON(!net);
return net_generic(net, phonet_net_id);
}
struct phonet_device_list *phonet_device_list(struct net *net)
{
struct phonet_net *pnn = phonet_pernet(net);
return &pnn->pndevs;
}
/* Allocate new Phonet device. */
static struct phonet_device *__phonet_device_alloc(struct net_device *dev)
{
struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
struct phonet_device *pnd = kmalloc(sizeof(*pnd), GFP_ATOMIC);
if (pnd == NULL)
return NULL;
pnd->netdev = dev;
bitmap_zero(pnd->addrs, 64);
BUG_ON(!mutex_is_locked(&pndevs->lock));
list_add_rcu(&pnd->list, &pndevs->list);
return pnd;
}
static struct phonet_device *__phonet_get(struct net_device *dev)
{
struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
struct phonet_device *pnd;
BUG_ON(!mutex_is_locked(&pndevs->lock));
list_for_each_entry(pnd, &pndevs->list, list) {
if (pnd->netdev == dev)
return pnd;
}
return NULL;
}
static struct phonet_device *__phonet_get_rcu(struct net_device *dev)
{
struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
struct phonet_device *pnd;
list_for_each_entry_rcu(pnd, &pndevs->list, list) {
if (pnd->netdev == dev)
return pnd;
}
return NULL;
}
static void phonet_device_destroy(struct net_device *dev)
{
struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
struct phonet_device *pnd;
ASSERT_RTNL();
mutex_lock(&pndevs->lock);
pnd = __phonet_get(dev);
if (pnd)
list_del_rcu(&pnd->list);
mutex_unlock(&pndevs->lock);
if (pnd) {
u8 addr;
for_each_set_bit(addr, pnd->addrs, 64)
phonet_address_notify(RTM_DELADDR, dev, addr);
kfree(pnd);
}
}
struct net_device *phonet_device_get(struct net *net)
{
struct phonet_device_list *pndevs = phonet_device_list(net);
struct phonet_device *pnd;
struct net_device *dev = NULL;
rcu_read_lock();
list_for_each_entry_rcu(pnd, &pndevs->list, list) {
dev = pnd->netdev;
BUG_ON(!dev);
if ((dev->reg_state == NETREG_REGISTERED) &&
((pnd->netdev->flags & IFF_UP)) == IFF_UP)
break;
dev = NULL;
}
if (dev)
dev_hold(dev);
rcu_read_unlock();
return dev;
}
int phonet_address_add(struct net_device *dev, u8 addr)
{
struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
struct phonet_device *pnd;
int err = 0;
mutex_lock(&pndevs->lock);
/* Find or create Phonet-specific device data */
pnd = __phonet_get(dev);
if (pnd == NULL)
pnd = __phonet_device_alloc(dev);
if (unlikely(pnd == NULL))
err = -ENOMEM;
else if (test_and_set_bit(addr >> 2, pnd->addrs))
err = -EEXIST;
mutex_unlock(&pndevs->lock);
return err;
}
int phonet_address_del(struct net_device *dev, u8 addr)
{
struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
struct phonet_device *pnd;
int err = 0;
mutex_lock(&pndevs->lock);
pnd = __phonet_get(dev);
if (!pnd || !test_and_clear_bit(addr >> 2, pnd->addrs)) {
err = -EADDRNOTAVAIL;
pnd = NULL;
} else if (bitmap_empty(pnd->addrs, 64))
list_del_rcu(&pnd->list);
else
pnd = NULL;
mutex_unlock(&pndevs->lock);
if (pnd) {
synchronize_rcu();
kfree(pnd);
}
return err;
}
/* Gets a source address toward a destination, through a interface. */
u8 phonet_address_get(struct net_device *dev, u8 daddr)
{
struct phonet_device *pnd;
u8 saddr;
rcu_read_lock();
pnd = __phonet_get_rcu(dev);
if (pnd) {
BUG_ON(bitmap_empty(pnd->addrs, 64));
/* Use same source address as destination, if possible */
if (test_bit(daddr >> 2, pnd->addrs))
saddr = daddr;
else
saddr = find_first_bit(pnd->addrs, 64) << 2;
} else
saddr = PN_NO_ADDR;
rcu_read_unlock();
if (saddr == PN_NO_ADDR) {
/* Fallback to another device */
struct net_device *def_dev;
def_dev = phonet_device_get(dev_net(dev));
if (def_dev) {
if (def_dev != dev)
saddr = phonet_address_get(def_dev, daddr);
dev_put(def_dev);
}
}
return saddr;
}
int phonet_address_lookup(struct net *net, u8 addr)
{
struct phonet_device_list *pndevs = phonet_device_list(net);
struct phonet_device *pnd;
int err = -EADDRNOTAVAIL;
rcu_read_lock();
list_for_each_entry_rcu(pnd, &pndevs->list, list) {
/* Don't allow unregistering devices! */
if ((pnd->netdev->reg_state != NETREG_REGISTERED) ||
((pnd->netdev->flags & IFF_UP)) != IFF_UP)
continue;
if (test_bit(addr >> 2, pnd->addrs)) {
err = 0;
goto found;
}
}
found:
rcu_read_unlock();
return err;
}
/* automatically configure a Phonet device, if supported */
static int phonet_device_autoconf(struct net_device *dev)
{
struct if_phonet_req req;
int ret;
if (!dev->netdev_ops->ndo_do_ioctl)
return -EOPNOTSUPP;
ret = dev->netdev_ops->ndo_do_ioctl(dev, (struct ifreq *)&req,
SIOCPNGAUTOCONF);
if (ret < 0)
return ret;
ASSERT_RTNL();
ret = phonet_address_add(dev, req.ifr_phonet_autoconf.device);
if (ret)
return ret;
phonet_address_notify(RTM_NEWADDR, dev,
req.ifr_phonet_autoconf.device);
return 0;
}
static void phonet_route_autodel(struct net_device *dev)
{
struct phonet_net *pnn = phonet_pernet(dev_net(dev));
unsigned i;
DECLARE_BITMAP(deleted, 64);
/* Remove left-over Phonet routes */
bitmap_zero(deleted, 64);
mutex_lock(&pnn->routes.lock);
for (i = 0; i < 64; i++)
if (dev == pnn->routes.table[i]) {
rcu_assign_pointer(pnn->routes.table[i], NULL);
set_bit(i, deleted);
}
mutex_unlock(&pnn->routes.lock);
if (bitmap_empty(deleted, 64))
return; /* short-circuit RCU */
synchronize_rcu();
for (i = find_first_bit(deleted, 64); i < 64;
i = find_next_bit(deleted, 64, i + 1)) {
rtm_phonet_notify(RTM_DELROUTE, dev, i);
dev_put(dev);
}
}
/* notify Phonet of device events */
static int phonet_device_notify(struct notifier_block *me, unsigned long what,
void *arg)
{
struct net_device *dev = arg;
switch (what) {
case NETDEV_REGISTER:
if (dev->type == ARPHRD_PHONET)
phonet_device_autoconf(dev);
break;
case NETDEV_UNREGISTER:
phonet_device_destroy(dev);
phonet_route_autodel(dev);
break;
}
return 0;
}
static struct notifier_block phonet_device_notifier = {
.notifier_call = phonet_device_notify,
.priority = 0,
};
/* Per-namespace Phonet devices handling */
static int __net_init phonet_init_net(struct net *net)
{
struct phonet_net *pnn = phonet_pernet(net);
if (!proc_net_fops_create(net, "phonet", 0, &pn_sock_seq_fops))
return -ENOMEM;
INIT_LIST_HEAD(&pnn->pndevs.list);
mutex_init(&pnn->pndevs.lock);
mutex_init(&pnn->routes.lock);
return 0;
}
static void __net_exit phonet_exit_net(struct net *net)
{
struct phonet_net *pnn = phonet_pernet(net);
struct net_device *dev;
unsigned i;
rtnl_lock();
for_each_netdev(net, dev)
phonet_device_destroy(dev);
for (i = 0; i < 64; i++) {
dev = pnn->routes.table[i];
if (dev) {
rtm_phonet_notify(RTM_DELROUTE, dev, i);
dev_put(dev);
}
}
rtnl_unlock();
proc_net_remove(net, "phonet");
}
static struct pernet_operations phonet_net_ops = {
.init = phonet_init_net,
.exit = phonet_exit_net,
.id = &phonet_net_id,
.size = sizeof(struct phonet_net),
};
/* Initialize Phonet devices list */
int __init phonet_device_init(void)
{
int err = register_pernet_device(&phonet_net_ops);
if (err)
return err;
register_netdevice_notifier(&phonet_device_notifier);
err = phonet_netlink_register();
if (err)
phonet_device_exit();
return err;
}
void phonet_device_exit(void)
{
rtnl_unregister_all(PF_PHONET);
unregister_netdevice_notifier(&phonet_device_notifier);
unregister_pernet_device(&phonet_net_ops);
}
int phonet_route_add(struct net_device *dev, u8 daddr)
{
struct phonet_net *pnn = phonet_pernet(dev_net(dev));
struct phonet_routes *routes = &pnn->routes;
int err = -EEXIST;
daddr = daddr >> 2;
mutex_lock(&routes->lock);
if (routes->table[daddr] == NULL) {
rcu_assign_pointer(routes->table[daddr], dev);
dev_hold(dev);
err = 0;
}
mutex_unlock(&routes->lock);
return err;
}
int phonet_route_del(struct net_device *dev, u8 daddr)
{
struct phonet_net *pnn = phonet_pernet(dev_net(dev));
struct phonet_routes *routes = &pnn->routes;
daddr = daddr >> 2;
mutex_lock(&routes->lock);
if (dev == routes->table[daddr])
rcu_assign_pointer(routes->table[daddr], NULL);
else
dev = NULL;
mutex_unlock(&routes->lock);
if (!dev)
return -ENOENT;
synchronize_rcu();
dev_put(dev);
return 0;
}
struct net_device *phonet_route_get(struct net *net, u8 daddr)
{
struct phonet_net *pnn = phonet_pernet(net);
struct phonet_routes *routes = &pnn->routes;
struct net_device *dev;
ASSERT_RTNL(); /* no need to hold the device */
daddr >>= 2;
rcu_read_lock();
dev = rcu_dereference(routes->table[daddr]);
rcu_read_unlock();
return dev;
}
struct net_device *phonet_route_output(struct net *net, u8 daddr)
{
struct phonet_net *pnn = phonet_pernet(net);
struct phonet_routes *routes = &pnn->routes;
struct net_device *dev;
daddr >>= 2;
rcu_read_lock();
dev = rcu_dereference(routes->table[daddr]);
if (dev)
dev_hold(dev);
rcu_read_unlock();
if (!dev)
dev = phonet_device_get(net); /* Default route */
return dev;
}