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