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 struct list_head x25_route_list = LIST_HEAD_INIT(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 } 123 124 /* 125 * Check that the device given is a valid X.25 interface that is "up". 126 */ 127 struct net_device *x25_dev_get(char *devname) 128 { 129 struct net_device *dev = dev_get_by_name(devname); 130 131 if (dev && 132 (!(dev->flags & IFF_UP) || (dev->type != ARPHRD_X25 133 #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE) 134 && dev->type != ARPHRD_ETHER 135 #endif 136 ))) 137 dev_put(dev); 138 139 return dev; 140 } 141 142 /** 143 * x25_get_route - Find a route given an X.25 address. 144 * @addr - address to find a route for 145 * 146 * Find a route given an X.25 address. 147 */ 148 struct x25_route *x25_get_route(struct x25_address *addr) 149 { 150 struct x25_route *rt, *use = NULL; 151 struct list_head *entry; 152 153 read_lock_bh(&x25_route_list_lock); 154 155 list_for_each(entry, &x25_route_list) { 156 rt = list_entry(entry, struct x25_route, node); 157 158 if (!memcmp(&rt->address, addr, rt->sigdigits)) { 159 if (!use) 160 use = rt; 161 else if (rt->sigdigits > use->sigdigits) 162 use = rt; 163 } 164 } 165 166 if (use) 167 x25_route_hold(use); 168 169 read_unlock_bh(&x25_route_list_lock); 170 return use; 171 } 172 173 /* 174 * Handle the ioctls that control the routing functions. 175 */ 176 int x25_route_ioctl(unsigned int cmd, void __user *arg) 177 { 178 struct x25_route_struct rt; 179 struct net_device *dev; 180 int rc = -EINVAL; 181 182 if (cmd != SIOCADDRT && cmd != SIOCDELRT) 183 goto out; 184 185 rc = -EFAULT; 186 if (copy_from_user(&rt, arg, sizeof(rt))) 187 goto out; 188 189 rc = -EINVAL; 190 if (rt.sigdigits < 0 || rt.sigdigits > 15) 191 goto out; 192 193 dev = x25_dev_get(rt.device); 194 if (!dev) 195 goto out; 196 197 if (cmd == SIOCADDRT) 198 rc = x25_add_route(&rt.address, rt.sigdigits, dev); 199 else 200 rc = x25_del_route(&rt.address, rt.sigdigits, dev); 201 dev_put(dev); 202 out: 203 return rc; 204 } 205 206 /* 207 * Release all memory associated with X.25 routing structures. 208 */ 209 void __exit x25_route_free(void) 210 { 211 struct x25_route *rt; 212 struct list_head *entry, *tmp; 213 214 write_lock_bh(&x25_route_list_lock); 215 list_for_each_safe(entry, tmp, &x25_route_list) { 216 rt = list_entry(entry, struct x25_route, node); 217 __x25_remove_route(rt); 218 } 219 write_unlock_bh(&x25_route_list_lock); 220 } 221