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![Xie He](/assets/img/avatar_default.png)
According to the X.25 documentation, there was a plan to implement X.25-over-802.2-LLC. It never finished but left various code stubs in the X.25 code. At this time it is unlikely that it would ever finish so it may be better to remove those code stubs. Also change the documentation to make it clear that this is not a ongoing plan anymore. Change words like "will" to "could", "would", etc. Cc: Martin Schiller <ms@dev.tdt.de> Signed-off-by: Xie He <xie.he.0141@gmail.com> Link: https://lore.kernel.org/r/20201209033346.83742-1-xie.he.0141@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
213 lines
4.4 KiB
C
213 lines
4.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* X.25 Packet Layer release 002
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*
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* This is ALPHA test software. This code may break your machine,
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* randomly fail to work with new releases, misbehave and/or generally
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* screw up. It might even work.
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*
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* This code REQUIRES 2.1.15 or higher
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*
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* History
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* X.25 001 Jonathan Naylor Started coding.
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*/
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#include <linux/if_arp.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <net/x25.h>
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LIST_HEAD(x25_route_list);
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DEFINE_RWLOCK(x25_route_list_lock);
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/*
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* Add a new route.
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*/
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static int x25_add_route(struct x25_address *address, unsigned int sigdigits,
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struct net_device *dev)
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{
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struct x25_route *rt;
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struct list_head *entry;
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int rc = -EINVAL;
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write_lock_bh(&x25_route_list_lock);
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list_for_each(entry, &x25_route_list) {
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rt = list_entry(entry, struct x25_route, node);
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if (!memcmp(&rt->address, address, sigdigits) &&
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rt->sigdigits == sigdigits)
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goto out;
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}
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rt = kmalloc(sizeof(*rt), GFP_ATOMIC);
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rc = -ENOMEM;
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if (!rt)
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goto out;
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strcpy(rt->address.x25_addr, "000000000000000");
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memcpy(rt->address.x25_addr, address->x25_addr, sigdigits);
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rt->sigdigits = sigdigits;
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rt->dev = dev;
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refcount_set(&rt->refcnt, 1);
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list_add(&rt->node, &x25_route_list);
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rc = 0;
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out:
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write_unlock_bh(&x25_route_list_lock);
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return rc;
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}
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/**
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* __x25_remove_route - remove route from x25_route_list
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* @rt: route to remove
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*
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* Remove route from x25_route_list. If it was there.
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* Caller must hold x25_route_list_lock.
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*/
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static void __x25_remove_route(struct x25_route *rt)
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{
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if (rt->node.next) {
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list_del(&rt->node);
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x25_route_put(rt);
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}
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}
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static int x25_del_route(struct x25_address *address, unsigned int sigdigits,
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struct net_device *dev)
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{
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struct x25_route *rt;
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struct list_head *entry;
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int rc = -EINVAL;
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write_lock_bh(&x25_route_list_lock);
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list_for_each(entry, &x25_route_list) {
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rt = list_entry(entry, struct x25_route, node);
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if (!memcmp(&rt->address, address, sigdigits) &&
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rt->sigdigits == sigdigits && rt->dev == dev) {
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__x25_remove_route(rt);
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rc = 0;
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break;
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}
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}
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write_unlock_bh(&x25_route_list_lock);
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return rc;
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}
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/*
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* A device has been removed, remove its routes.
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*/
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void x25_route_device_down(struct net_device *dev)
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{
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struct x25_route *rt;
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struct list_head *entry, *tmp;
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write_lock_bh(&x25_route_list_lock);
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list_for_each_safe(entry, tmp, &x25_route_list) {
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rt = list_entry(entry, struct x25_route, node);
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if (rt->dev == dev)
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__x25_remove_route(rt);
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}
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write_unlock_bh(&x25_route_list_lock);
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}
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/*
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* Check that the device given is a valid X.25 interface that is "up".
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*/
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struct net_device *x25_dev_get(char *devname)
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{
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struct net_device *dev = dev_get_by_name(&init_net, devname);
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if (dev && (!(dev->flags & IFF_UP) || dev->type != ARPHRD_X25)) {
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dev_put(dev);
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dev = NULL;
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}
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return dev;
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}
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/**
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* x25_get_route - Find a route given an X.25 address.
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* @addr: - address to find a route for
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*
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* Find a route given an X.25 address.
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*/
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struct x25_route *x25_get_route(struct x25_address *addr)
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{
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struct x25_route *rt, *use = NULL;
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struct list_head *entry;
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read_lock_bh(&x25_route_list_lock);
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list_for_each(entry, &x25_route_list) {
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rt = list_entry(entry, struct x25_route, node);
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if (!memcmp(&rt->address, addr, rt->sigdigits)) {
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if (!use)
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use = rt;
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else if (rt->sigdigits > use->sigdigits)
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use = rt;
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}
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}
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if (use)
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x25_route_hold(use);
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read_unlock_bh(&x25_route_list_lock);
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return use;
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}
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/*
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* Handle the ioctls that control the routing functions.
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*/
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int x25_route_ioctl(unsigned int cmd, void __user *arg)
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{
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struct x25_route_struct rt;
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struct net_device *dev;
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int rc = -EINVAL;
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if (cmd != SIOCADDRT && cmd != SIOCDELRT)
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goto out;
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rc = -EFAULT;
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if (copy_from_user(&rt, arg, sizeof(rt)))
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goto out;
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rc = -EINVAL;
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if (rt.sigdigits > 15)
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goto out;
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dev = x25_dev_get(rt.device);
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if (!dev)
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goto out;
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if (cmd == SIOCADDRT)
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rc = x25_add_route(&rt.address, rt.sigdigits, dev);
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else
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rc = x25_del_route(&rt.address, rt.sigdigits, dev);
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dev_put(dev);
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out:
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return rc;
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}
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/*
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* Release all memory associated with X.25 routing structures.
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*/
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void __exit x25_route_free(void)
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{
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struct x25_route *rt;
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struct list_head *entry, *tmp;
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write_lock_bh(&x25_route_list_lock);
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list_for_each_safe(entry, tmp, &x25_route_list) {
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rt = list_entry(entry, struct x25_route, node);
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__x25_remove_route(rt);
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}
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write_unlock_bh(&x25_route_list_lock);
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}
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