1 /* 2 * X.25 Packet Layer release 002 3 * 4 * This is ALPHA test software. This code may break your machine, 5 * randomly fail to work with new releases, misbehave and/or generally 6 * screw up. It might even work. 7 * 8 * This code REQUIRES 2.1.15 or higher 9 * 10 * This module: 11 * This module is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU General Public License 13 * as published by the Free Software Foundation; either version 14 * 2 of the License, or (at your option) any later version. 15 * 16 * History 17 * X.25 001 Jonathan Naylor Started coding. 18 */ 19 20 #include <linux/if_arp.h> 21 #include <linux/init.h> 22 #include <linux/slab.h> 23 #include <net/x25.h> 24 25 LIST_HEAD(x25_route_list); 26 DEFINE_RWLOCK(x25_route_list_lock); 27 28 /* 29 * Add a new route. 30 */ 31 static int x25_add_route(struct x25_address *address, unsigned int sigdigits, 32 struct net_device *dev) 33 { 34 struct x25_route *rt; 35 struct list_head *entry; 36 int rc = -EINVAL; 37 38 write_lock_bh(&x25_route_list_lock); 39 40 list_for_each(entry, &x25_route_list) { 41 rt = list_entry(entry, struct x25_route, node); 42 43 if (!memcmp(&rt->address, address, sigdigits) && 44 rt->sigdigits == sigdigits) 45 goto out; 46 } 47 48 rt = kmalloc(sizeof(*rt), GFP_ATOMIC); 49 rc = -ENOMEM; 50 if (!rt) 51 goto out; 52 53 strcpy(rt->address.x25_addr, "000000000000000"); 54 memcpy(rt->address.x25_addr, address->x25_addr, sigdigits); 55 56 rt->sigdigits = sigdigits; 57 rt->dev = dev; 58 atomic_set(&rt->refcnt, 1); 59 60 list_add(&rt->node, &x25_route_list); 61 rc = 0; 62 out: 63 write_unlock_bh(&x25_route_list_lock); 64 return rc; 65 } 66 67 /** 68 * __x25_remove_route - remove route from x25_route_list 69 * @rt: route to remove 70 * 71 * Remove route from x25_route_list. If it was there. 72 * Caller must hold x25_route_list_lock. 73 */ 74 static void __x25_remove_route(struct x25_route *rt) 75 { 76 if (rt->node.next) { 77 list_del(&rt->node); 78 x25_route_put(rt); 79 } 80 } 81 82 static int x25_del_route(struct x25_address *address, unsigned int sigdigits, 83 struct net_device *dev) 84 { 85 struct x25_route *rt; 86 struct list_head *entry; 87 int rc = -EINVAL; 88 89 write_lock_bh(&x25_route_list_lock); 90 91 list_for_each(entry, &x25_route_list) { 92 rt = list_entry(entry, struct x25_route, node); 93 94 if (!memcmp(&rt->address, address, sigdigits) && 95 rt->sigdigits == sigdigits && rt->dev == dev) { 96 __x25_remove_route(rt); 97 rc = 0; 98 break; 99 } 100 } 101 102 write_unlock_bh(&x25_route_list_lock); 103 return rc; 104 } 105 106 /* 107 * A device has been removed, remove its routes. 108 */ 109 void x25_route_device_down(struct net_device *dev) 110 { 111 struct x25_route *rt; 112 struct list_head *entry, *tmp; 113 114 write_lock_bh(&x25_route_list_lock); 115 116 list_for_each_safe(entry, tmp, &x25_route_list) { 117 rt = list_entry(entry, struct x25_route, node); 118 119 if (rt->dev == dev) 120 __x25_remove_route(rt); 121 } 122 write_unlock_bh(&x25_route_list_lock); 123 124 /* Remove any related forwarding */ 125 x25_clear_forward_by_dev(dev); 126 } 127 128 /* 129 * Check that the device given is a valid X.25 interface that is "up". 130 */ 131 struct net_device *x25_dev_get(char *devname) 132 { 133 struct net_device *dev = dev_get_by_name(&init_net, devname); 134 135 if (dev && 136 (!(dev->flags & IFF_UP) || (dev->type != ARPHRD_X25 137 #if IS_ENABLED(CONFIG_LLC) 138 && dev->type != ARPHRD_ETHER 139 #endif 140 ))){ 141 dev_put(dev); 142 dev = NULL; 143 } 144 145 return dev; 146 } 147 148 /** 149 * x25_get_route - Find a route given an X.25 address. 150 * @addr - address to find a route for 151 * 152 * Find a route given an X.25 address. 153 */ 154 struct x25_route *x25_get_route(struct x25_address *addr) 155 { 156 struct x25_route *rt, *use = NULL; 157 struct list_head *entry; 158 159 read_lock_bh(&x25_route_list_lock); 160 161 list_for_each(entry, &x25_route_list) { 162 rt = list_entry(entry, struct x25_route, node); 163 164 if (!memcmp(&rt->address, addr, rt->sigdigits)) { 165 if (!use) 166 use = rt; 167 else if (rt->sigdigits > use->sigdigits) 168 use = rt; 169 } 170 } 171 172 if (use) 173 x25_route_hold(use); 174 175 read_unlock_bh(&x25_route_list_lock); 176 return use; 177 } 178 179 /* 180 * Handle the ioctls that control the routing functions. 181 */ 182 int x25_route_ioctl(unsigned int cmd, void __user *arg) 183 { 184 struct x25_route_struct rt; 185 struct net_device *dev; 186 int rc = -EINVAL; 187 188 if (cmd != SIOCADDRT && cmd != SIOCDELRT) 189 goto out; 190 191 rc = -EFAULT; 192 if (copy_from_user(&rt, arg, sizeof(rt))) 193 goto out; 194 195 rc = -EINVAL; 196 if (rt.sigdigits > 15) 197 goto out; 198 199 dev = x25_dev_get(rt.device); 200 if (!dev) 201 goto out; 202 203 if (cmd == SIOCADDRT) 204 rc = x25_add_route(&rt.address, rt.sigdigits, dev); 205 else 206 rc = x25_del_route(&rt.address, rt.sigdigits, dev); 207 dev_put(dev); 208 out: 209 return rc; 210 } 211 212 /* 213 * Release all memory associated with X.25 routing structures. 214 */ 215 void __exit x25_route_free(void) 216 { 217 struct x25_route *rt; 218 struct list_head *entry, *tmp; 219 220 write_lock_bh(&x25_route_list_lock); 221 list_for_each_safe(entry, tmp, &x25_route_list) { 222 rt = list_entry(entry, struct x25_route, node); 223 __x25_remove_route(rt); 224 } 225 write_unlock_bh(&x25_route_list_lock); 226 } 227