// SPDX-License-Identifier: GPL-2.0-or-later /* * X.25 Packet Layer release 002 * * This is ALPHA test software. This code may break your machine, * randomly fail to work with new releases, misbehave and/or generally * screw up. It might even work. * * This code REQUIRES 2.1.15 or higher * * History * X.25 001 Jonathan Naylor Started coding. */ #include <linux/if_arp.h> #include <linux/init.h> #include <linux/slab.h> #include <net/x25.h> LIST_HEAD(x25_route_list); DEFINE_RWLOCK(x25_route_list_lock); /* * Add a new route. */ static int x25_add_route(struct x25_address *address, unsigned int sigdigits, struct net_device *dev) { struct x25_route *rt; struct list_head *entry; int rc = -EINVAL; write_lock_bh(&x25_route_list_lock); list_for_each(entry, &x25_route_list) { rt = list_entry(entry, struct x25_route, node); if (!memcmp(&rt->address, address, sigdigits) && rt->sigdigits == sigdigits) goto out; } rt = kmalloc(sizeof(*rt), GFP_ATOMIC); rc = -ENOMEM; if (!rt) goto out; strcpy(rt->address.x25_addr, "000000000000000"); memcpy(rt->address.x25_addr, address->x25_addr, sigdigits); rt->sigdigits = sigdigits; rt->dev = dev; refcount_set(&rt->refcnt, 1); list_add(&rt->node, &x25_route_list); rc = 0; out: write_unlock_bh(&x25_route_list_lock); return rc; } /** * __x25_remove_route - remove route from x25_route_list * @rt: route to remove * * Remove route from x25_route_list. If it was there. * Caller must hold x25_route_list_lock. */ static void __x25_remove_route(struct x25_route *rt) { if (rt->node.next) { list_del(&rt->node); x25_route_put(rt); } } static int x25_del_route(struct x25_address *address, unsigned int sigdigits, struct net_device *dev) { struct x25_route *rt; struct list_head *entry; int rc = -EINVAL; write_lock_bh(&x25_route_list_lock); list_for_each(entry, &x25_route_list) { rt = list_entry(entry, struct x25_route, node); if (!memcmp(&rt->address, address, sigdigits) && rt->sigdigits == sigdigits && rt->dev == dev) { __x25_remove_route(rt); rc = 0; break; } } write_unlock_bh(&x25_route_list_lock); return rc; } /* * A device has been removed, remove its routes. */ void x25_route_device_down(struct net_device *dev) { struct x25_route *rt; struct list_head *entry, *tmp; write_lock_bh(&x25_route_list_lock); list_for_each_safe(entry, tmp, &x25_route_list) { rt = list_entry(entry, struct x25_route, node); if (rt->dev == dev) __x25_remove_route(rt); } write_unlock_bh(&x25_route_list_lock); /* Remove any related forwarding */ x25_clear_forward_by_dev(dev); } /* * Check that the device given is a valid X.25 interface that is "up". */ struct net_device *x25_dev_get(char *devname) { struct net_device *dev = dev_get_by_name(&init_net, devname); if (dev && (!(dev->flags & IFF_UP) || (dev->type != ARPHRD_X25 #if IS_ENABLED(CONFIG_LLC) && dev->type != ARPHRD_ETHER #endif ))){ dev_put(dev); dev = NULL; } return dev; } /** * x25_get_route - Find a route given an X.25 address. * @addr: - address to find a route for * * Find a route given an X.25 address. */ struct x25_route *x25_get_route(struct x25_address *addr) { struct x25_route *rt, *use = NULL; struct list_head *entry; read_lock_bh(&x25_route_list_lock); list_for_each(entry, &x25_route_list) { rt = list_entry(entry, struct x25_route, node); if (!memcmp(&rt->address, addr, rt->sigdigits)) { if (!use) use = rt; else if (rt->sigdigits > use->sigdigits) use = rt; } } if (use) x25_route_hold(use); read_unlock_bh(&x25_route_list_lock); return use; } /* * Handle the ioctls that control the routing functions. */ int x25_route_ioctl(unsigned int cmd, void __user *arg) { struct x25_route_struct rt; struct net_device *dev; int rc = -EINVAL; if (cmd != SIOCADDRT && cmd != SIOCDELRT) goto out; rc = -EFAULT; if (copy_from_user(&rt, arg, sizeof(rt))) goto out; rc = -EINVAL; if (rt.sigdigits > 15) goto out; dev = x25_dev_get(rt.device); if (!dev) goto out; if (cmd == SIOCADDRT) rc = x25_add_route(&rt.address, rt.sigdigits, dev); else rc = x25_del_route(&rt.address, rt.sigdigits, dev); dev_put(dev); out: return rc; } /* * Release all memory associated with X.25 routing structures. */ void __exit x25_route_free(void) { struct x25_route *rt; struct list_head *entry, *tmp; write_lock_bh(&x25_route_list_lock); list_for_each_safe(entry, tmp, &x25_route_list) { rt = list_entry(entry, struct x25_route, node); __x25_remove_route(rt); } write_unlock_bh(&x25_route_list_lock); }