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![Yajun Deng](/assets/img/avatar_default.png)
The 'if (dev)' statement already move into dev_{put , hold}, so remove redundant if statements. Signed-off-by: Yajun Deng <yajun.deng@linux.dev> Signed-off-by: David S. Miller <davem@davemloft.net>
419 lines
9.5 KiB
C
419 lines
9.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* File: pn_dev.c
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*
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* Phonet network device
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*
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* Copyright (C) 2008 Nokia Corporation.
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*
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* Authors: Sakari Ailus <sakari.ailus@nokia.com>
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* Rémi Denis-Courmont
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*/
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#include <linux/kernel.h>
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#include <linux/net.h>
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#include <linux/slab.h>
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#include <linux/netdevice.h>
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#include <linux/phonet.h>
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#include <linux/proc_fs.h>
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#include <linux/if_arp.h>
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#include <net/sock.h>
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#include <net/netns/generic.h>
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#include <net/phonet/pn_dev.h>
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struct phonet_routes {
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struct mutex lock;
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struct net_device __rcu *table[64];
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};
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struct phonet_net {
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struct phonet_device_list pndevs;
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struct phonet_routes routes;
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};
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static unsigned int phonet_net_id __read_mostly;
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static struct phonet_net *phonet_pernet(struct net *net)
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{
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return net_generic(net, phonet_net_id);
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}
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struct phonet_device_list *phonet_device_list(struct net *net)
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{
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struct phonet_net *pnn = phonet_pernet(net);
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return &pnn->pndevs;
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}
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/* Allocate new Phonet device. */
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static struct phonet_device *__phonet_device_alloc(struct net_device *dev)
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{
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struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
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struct phonet_device *pnd = kmalloc(sizeof(*pnd), GFP_ATOMIC);
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if (pnd == NULL)
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return NULL;
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pnd->netdev = dev;
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bitmap_zero(pnd->addrs, 64);
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BUG_ON(!mutex_is_locked(&pndevs->lock));
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list_add_rcu(&pnd->list, &pndevs->list);
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return pnd;
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}
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static struct phonet_device *__phonet_get(struct net_device *dev)
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{
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struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
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struct phonet_device *pnd;
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BUG_ON(!mutex_is_locked(&pndevs->lock));
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list_for_each_entry(pnd, &pndevs->list, list) {
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if (pnd->netdev == dev)
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return pnd;
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}
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return NULL;
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}
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static struct phonet_device *__phonet_get_rcu(struct net_device *dev)
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{
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struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
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struct phonet_device *pnd;
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list_for_each_entry_rcu(pnd, &pndevs->list, list) {
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if (pnd->netdev == dev)
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return pnd;
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}
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return NULL;
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}
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static void phonet_device_destroy(struct net_device *dev)
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{
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struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
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struct phonet_device *pnd;
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ASSERT_RTNL();
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mutex_lock(&pndevs->lock);
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pnd = __phonet_get(dev);
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if (pnd)
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list_del_rcu(&pnd->list);
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mutex_unlock(&pndevs->lock);
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if (pnd) {
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u8 addr;
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for_each_set_bit(addr, pnd->addrs, 64)
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phonet_address_notify(RTM_DELADDR, dev, addr);
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kfree(pnd);
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}
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}
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struct net_device *phonet_device_get(struct net *net)
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{
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struct phonet_device_list *pndevs = phonet_device_list(net);
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struct phonet_device *pnd;
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struct net_device *dev = NULL;
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rcu_read_lock();
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list_for_each_entry_rcu(pnd, &pndevs->list, list) {
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dev = pnd->netdev;
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BUG_ON(!dev);
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if ((dev->reg_state == NETREG_REGISTERED) &&
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((pnd->netdev->flags & IFF_UP)) == IFF_UP)
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break;
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dev = NULL;
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}
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dev_hold(dev);
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rcu_read_unlock();
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return dev;
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}
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int phonet_address_add(struct net_device *dev, u8 addr)
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{
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struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
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struct phonet_device *pnd;
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int err = 0;
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mutex_lock(&pndevs->lock);
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/* Find or create Phonet-specific device data */
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pnd = __phonet_get(dev);
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if (pnd == NULL)
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pnd = __phonet_device_alloc(dev);
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if (unlikely(pnd == NULL))
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err = -ENOMEM;
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else if (test_and_set_bit(addr >> 2, pnd->addrs))
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err = -EEXIST;
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mutex_unlock(&pndevs->lock);
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return err;
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}
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int phonet_address_del(struct net_device *dev, u8 addr)
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{
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struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
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struct phonet_device *pnd;
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int err = 0;
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mutex_lock(&pndevs->lock);
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pnd = __phonet_get(dev);
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if (!pnd || !test_and_clear_bit(addr >> 2, pnd->addrs)) {
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err = -EADDRNOTAVAIL;
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pnd = NULL;
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} else if (bitmap_empty(pnd->addrs, 64))
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list_del_rcu(&pnd->list);
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else
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pnd = NULL;
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mutex_unlock(&pndevs->lock);
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if (pnd)
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kfree_rcu(pnd, rcu);
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return err;
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}
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/* Gets a source address toward a destination, through a interface. */
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u8 phonet_address_get(struct net_device *dev, u8 daddr)
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{
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struct phonet_device *pnd;
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u8 saddr;
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rcu_read_lock();
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pnd = __phonet_get_rcu(dev);
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if (pnd) {
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BUG_ON(bitmap_empty(pnd->addrs, 64));
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/* Use same source address as destination, if possible */
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if (test_bit(daddr >> 2, pnd->addrs))
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saddr = daddr;
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else
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saddr = find_first_bit(pnd->addrs, 64) << 2;
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} else
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saddr = PN_NO_ADDR;
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rcu_read_unlock();
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if (saddr == PN_NO_ADDR) {
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/* Fallback to another device */
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struct net_device *def_dev;
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def_dev = phonet_device_get(dev_net(dev));
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if (def_dev) {
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if (def_dev != dev)
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saddr = phonet_address_get(def_dev, daddr);
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dev_put(def_dev);
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}
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}
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return saddr;
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}
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int phonet_address_lookup(struct net *net, u8 addr)
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{
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struct phonet_device_list *pndevs = phonet_device_list(net);
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struct phonet_device *pnd;
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int err = -EADDRNOTAVAIL;
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rcu_read_lock();
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list_for_each_entry_rcu(pnd, &pndevs->list, list) {
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/* Don't allow unregistering devices! */
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if ((pnd->netdev->reg_state != NETREG_REGISTERED) ||
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((pnd->netdev->flags & IFF_UP)) != IFF_UP)
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continue;
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if (test_bit(addr >> 2, pnd->addrs)) {
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err = 0;
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goto found;
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}
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}
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found:
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rcu_read_unlock();
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return err;
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}
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/* automatically configure a Phonet device, if supported */
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static int phonet_device_autoconf(struct net_device *dev)
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{
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struct if_phonet_req req;
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int ret;
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if (!dev->netdev_ops->ndo_siocdevprivate)
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return -EOPNOTSUPP;
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ret = dev->netdev_ops->ndo_siocdevprivate(dev, (struct ifreq *)&req,
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NULL, SIOCPNGAUTOCONF);
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if (ret < 0)
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return ret;
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ASSERT_RTNL();
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ret = phonet_address_add(dev, req.ifr_phonet_autoconf.device);
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if (ret)
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return ret;
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phonet_address_notify(RTM_NEWADDR, dev,
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req.ifr_phonet_autoconf.device);
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return 0;
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}
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static void phonet_route_autodel(struct net_device *dev)
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{
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struct phonet_net *pnn = phonet_pernet(dev_net(dev));
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unsigned int i;
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DECLARE_BITMAP(deleted, 64);
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/* Remove left-over Phonet routes */
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bitmap_zero(deleted, 64);
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mutex_lock(&pnn->routes.lock);
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for (i = 0; i < 64; i++)
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if (rcu_access_pointer(pnn->routes.table[i]) == dev) {
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RCU_INIT_POINTER(pnn->routes.table[i], NULL);
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set_bit(i, deleted);
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}
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mutex_unlock(&pnn->routes.lock);
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if (bitmap_empty(deleted, 64))
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return; /* short-circuit RCU */
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synchronize_rcu();
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for_each_set_bit(i, deleted, 64) {
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rtm_phonet_notify(RTM_DELROUTE, dev, i);
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dev_put(dev);
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}
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}
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/* notify Phonet of device events */
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static int phonet_device_notify(struct notifier_block *me, unsigned long what,
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void *ptr)
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{
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struct net_device *dev = netdev_notifier_info_to_dev(ptr);
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switch (what) {
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case NETDEV_REGISTER:
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if (dev->type == ARPHRD_PHONET)
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phonet_device_autoconf(dev);
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break;
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case NETDEV_UNREGISTER:
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phonet_device_destroy(dev);
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phonet_route_autodel(dev);
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break;
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}
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return 0;
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}
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static struct notifier_block phonet_device_notifier = {
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.notifier_call = phonet_device_notify,
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.priority = 0,
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};
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/* Per-namespace Phonet devices handling */
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static int __net_init phonet_init_net(struct net *net)
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{
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struct phonet_net *pnn = phonet_pernet(net);
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if (!proc_create_net("phonet", 0, net->proc_net, &pn_sock_seq_ops,
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sizeof(struct seq_net_private)))
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return -ENOMEM;
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INIT_LIST_HEAD(&pnn->pndevs.list);
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mutex_init(&pnn->pndevs.lock);
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mutex_init(&pnn->routes.lock);
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return 0;
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}
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static void __net_exit phonet_exit_net(struct net *net)
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{
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struct phonet_net *pnn = phonet_pernet(net);
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remove_proc_entry("phonet", net->proc_net);
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WARN_ON_ONCE(!list_empty(&pnn->pndevs.list));
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}
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static struct pernet_operations phonet_net_ops = {
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.init = phonet_init_net,
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.exit = phonet_exit_net,
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.id = &phonet_net_id,
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.size = sizeof(struct phonet_net),
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};
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/* Initialize Phonet devices list */
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int __init phonet_device_init(void)
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{
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int err = register_pernet_subsys(&phonet_net_ops);
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if (err)
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return err;
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proc_create_net("pnresource", 0, init_net.proc_net, &pn_res_seq_ops,
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sizeof(struct seq_net_private));
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register_netdevice_notifier(&phonet_device_notifier);
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err = phonet_netlink_register();
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if (err)
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phonet_device_exit();
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return err;
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}
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void phonet_device_exit(void)
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{
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rtnl_unregister_all(PF_PHONET);
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unregister_netdevice_notifier(&phonet_device_notifier);
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unregister_pernet_subsys(&phonet_net_ops);
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remove_proc_entry("pnresource", init_net.proc_net);
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}
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int phonet_route_add(struct net_device *dev, u8 daddr)
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{
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struct phonet_net *pnn = phonet_pernet(dev_net(dev));
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struct phonet_routes *routes = &pnn->routes;
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int err = -EEXIST;
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daddr = daddr >> 2;
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mutex_lock(&routes->lock);
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if (routes->table[daddr] == NULL) {
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rcu_assign_pointer(routes->table[daddr], dev);
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dev_hold(dev);
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err = 0;
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}
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mutex_unlock(&routes->lock);
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return err;
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}
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int phonet_route_del(struct net_device *dev, u8 daddr)
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{
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struct phonet_net *pnn = phonet_pernet(dev_net(dev));
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struct phonet_routes *routes = &pnn->routes;
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daddr = daddr >> 2;
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mutex_lock(&routes->lock);
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if (rcu_access_pointer(routes->table[daddr]) == dev)
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RCU_INIT_POINTER(routes->table[daddr], NULL);
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else
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dev = NULL;
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mutex_unlock(&routes->lock);
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if (!dev)
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return -ENOENT;
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synchronize_rcu();
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dev_put(dev);
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return 0;
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}
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struct net_device *phonet_route_get_rcu(struct net *net, u8 daddr)
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{
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struct phonet_net *pnn = phonet_pernet(net);
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struct phonet_routes *routes = &pnn->routes;
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struct net_device *dev;
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daddr >>= 2;
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dev = rcu_dereference(routes->table[daddr]);
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return dev;
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}
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struct net_device *phonet_route_output(struct net *net, u8 daddr)
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{
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struct phonet_net *pnn = phonet_pernet(net);
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struct phonet_routes *routes = &pnn->routes;
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struct net_device *dev;
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daddr >>= 2;
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rcu_read_lock();
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dev = rcu_dereference(routes->table[daddr]);
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dev_hold(dev);
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rcu_read_unlock();
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if (!dev)
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dev = phonet_device_get(net); /* Default route */
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return dev;
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}
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