1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * X.25 Packet Layer release 002 4 * 5 * This is ALPHA test software. This code may break your machine, 6 * randomly fail to work with new releases, misbehave and/or generally 7 * screw up. It might even work. 8 * 9 * This code REQUIRES 2.1.15 or higher 10 * 11 * History 12 * X.25 001 Jonathan Naylor Started coding. 13 */ 14 15 #include <linux/if_arp.h> 16 #include <linux/init.h> 17 #include <linux/slab.h> 18 #include <net/x25.h> 19 20 LIST_HEAD(x25_route_list); 21 DEFINE_RWLOCK(x25_route_list_lock); 22 23 /* 24 * Add a new route. 25 */ 26 static int x25_add_route(struct x25_address *address, unsigned int sigdigits, 27 struct net_device *dev) 28 { 29 struct x25_route *rt; 30 int rc = -EINVAL; 31 32 write_lock_bh(&x25_route_list_lock); 33 34 list_for_each_entry(rt, &x25_route_list, node) { 35 if (!memcmp(&rt->address, address, sigdigits) && 36 rt->sigdigits == sigdigits) 37 goto out; 38 } 39 40 rt = kmalloc(sizeof(*rt), GFP_ATOMIC); 41 rc = -ENOMEM; 42 if (!rt) 43 goto out; 44 45 strcpy(rt->address.x25_addr, "000000000000000"); 46 memcpy(rt->address.x25_addr, address->x25_addr, sigdigits); 47 48 rt->sigdigits = sigdigits; 49 rt->dev = dev; 50 refcount_set(&rt->refcnt, 1); 51 52 list_add(&rt->node, &x25_route_list); 53 rc = 0; 54 out: 55 write_unlock_bh(&x25_route_list_lock); 56 return rc; 57 } 58 59 /** 60 * __x25_remove_route - remove route from x25_route_list 61 * @rt: route to remove 62 * 63 * Remove route from x25_route_list. If it was there. 64 * Caller must hold x25_route_list_lock. 65 */ 66 static void __x25_remove_route(struct x25_route *rt) 67 { 68 if (rt->node.next) { 69 list_del(&rt->node); 70 x25_route_put(rt); 71 } 72 } 73 74 static int x25_del_route(struct x25_address *address, unsigned int sigdigits, 75 struct net_device *dev) 76 { 77 struct x25_route *rt; 78 int rc = -EINVAL; 79 80 write_lock_bh(&x25_route_list_lock); 81 82 list_for_each_entry(rt, &x25_route_list, node) { 83 if (!memcmp(&rt->address, address, sigdigits) && 84 rt->sigdigits == sigdigits && rt->dev == dev) { 85 __x25_remove_route(rt); 86 rc = 0; 87 break; 88 } 89 } 90 91 write_unlock_bh(&x25_route_list_lock); 92 return rc; 93 } 94 95 /* 96 * A device has been removed, remove its routes. 97 */ 98 void x25_route_device_down(struct net_device *dev) 99 { 100 struct x25_route *rt; 101 struct list_head *entry, *tmp; 102 103 write_lock_bh(&x25_route_list_lock); 104 105 list_for_each_safe(entry, tmp, &x25_route_list) { 106 rt = list_entry(entry, struct x25_route, node); 107 108 if (rt->dev == dev) 109 __x25_remove_route(rt); 110 } 111 write_unlock_bh(&x25_route_list_lock); 112 } 113 114 /* 115 * Check that the device given is a valid X.25 interface that is "up". 116 */ 117 struct net_device *x25_dev_get(char *devname) 118 { 119 struct net_device *dev = dev_get_by_name(&init_net, devname); 120 121 if (dev && (!(dev->flags & IFF_UP) || dev->type != ARPHRD_X25)) { 122 dev_put(dev); 123 dev = NULL; 124 } 125 126 return dev; 127 } 128 129 /** 130 * x25_get_route - Find a route given an X.25 address. 131 * @addr: - address to find a route for 132 * 133 * Find a route given an X.25 address. 134 */ 135 struct x25_route *x25_get_route(struct x25_address *addr) 136 { 137 struct x25_route *rt, *use = NULL; 138 139 read_lock_bh(&x25_route_list_lock); 140 141 list_for_each_entry(rt, &x25_route_list, node) { 142 if (!memcmp(&rt->address, addr, rt->sigdigits)) { 143 if (!use) 144 use = rt; 145 else if (rt->sigdigits > use->sigdigits) 146 use = rt; 147 } 148 } 149 150 if (use) 151 x25_route_hold(use); 152 153 read_unlock_bh(&x25_route_list_lock); 154 return use; 155 } 156 157 /* 158 * Handle the ioctls that control the routing functions. 159 */ 160 int x25_route_ioctl(unsigned int cmd, void __user *arg) 161 { 162 struct x25_route_struct rt; 163 struct net_device *dev; 164 int rc = -EINVAL; 165 166 if (cmd != SIOCADDRT && cmd != SIOCDELRT) 167 goto out; 168 169 rc = -EFAULT; 170 if (copy_from_user(&rt, arg, sizeof(rt))) 171 goto out; 172 173 rc = -EINVAL; 174 if (rt.sigdigits > 15) 175 goto out; 176 177 dev = x25_dev_get(rt.device); 178 if (!dev) 179 goto out; 180 181 if (cmd == SIOCADDRT) 182 rc = x25_add_route(&rt.address, rt.sigdigits, dev); 183 else 184 rc = x25_del_route(&rt.address, rt.sigdigits, dev); 185 dev_put(dev); 186 out: 187 return rc; 188 } 189 190 /* 191 * Release all memory associated with X.25 routing structures. 192 */ 193 void __exit x25_route_free(void) 194 { 195 struct x25_route *rt; 196 struct list_head *entry, *tmp; 197 198 write_lock_bh(&x25_route_list_lock); 199 list_for_each_safe(entry, tmp, &x25_route_list) { 200 rt = list_entry(entry, struct x25_route, node); 201 __x25_remove_route(rt); 202 } 203 write_unlock_bh(&x25_route_list_lock); 204 } 205