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