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 */
x25_add_route(struct x25_address * address,unsigned int sigdigits,struct net_device * dev)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 */
__x25_remove_route(struct x25_route * rt)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
x25_del_route(struct x25_address * address,unsigned int sigdigits,struct net_device * dev)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 */
x25_route_device_down(struct net_device * dev)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 /* Remove any related forwarding */
120 x25_clear_forward_by_dev(dev);
121 }
122
123 /*
124 * Check that the device given is a valid X.25 interface that is "up".
125 */
x25_dev_get(char * devname)126 struct net_device *x25_dev_get(char *devname)
127 {
128 struct net_device *dev = dev_get_by_name(&init_net, devname);
129
130 if (dev &&
131 (!(dev->flags & IFF_UP) || (dev->type != ARPHRD_X25
132 #if IS_ENABLED(CONFIG_LLC)
133 && dev->type != ARPHRD_ETHER
134 #endif
135 ))){
136 dev_put(dev);
137 dev = NULL;
138 }
139
140 return dev;
141 }
142
143 /**
144 * x25_get_route - Find a route given an X.25 address.
145 * @addr - address to find a route for
146 *
147 * Find a route given an X.25 address.
148 */
x25_get_route(struct x25_address * addr)149 struct x25_route *x25_get_route(struct x25_address *addr)
150 {
151 struct x25_route *rt, *use = NULL;
152 struct list_head *entry;
153
154 read_lock_bh(&x25_route_list_lock);
155
156 list_for_each(entry, &x25_route_list) {
157 rt = list_entry(entry, struct x25_route, node);
158
159 if (!memcmp(&rt->address, addr, rt->sigdigits)) {
160 if (!use)
161 use = rt;
162 else if (rt->sigdigits > use->sigdigits)
163 use = rt;
164 }
165 }
166
167 if (use)
168 x25_route_hold(use);
169
170 read_unlock_bh(&x25_route_list_lock);
171 return use;
172 }
173
174 /*
175 * Handle the ioctls that control the routing functions.
176 */
x25_route_ioctl(unsigned int cmd,void __user * arg)177 int x25_route_ioctl(unsigned int cmd, void __user *arg)
178 {
179 struct x25_route_struct rt;
180 struct net_device *dev;
181 int rc = -EINVAL;
182
183 if (cmd != SIOCADDRT && cmd != SIOCDELRT)
184 goto out;
185
186 rc = -EFAULT;
187 if (copy_from_user(&rt, arg, sizeof(rt)))
188 goto out;
189
190 rc = -EINVAL;
191 if (rt.sigdigits > 15)
192 goto out;
193
194 dev = x25_dev_get(rt.device);
195 if (!dev)
196 goto out;
197
198 if (cmd == SIOCADDRT)
199 rc = x25_add_route(&rt.address, rt.sigdigits, dev);
200 else
201 rc = x25_del_route(&rt.address, rt.sigdigits, dev);
202 dev_put(dev);
203 out:
204 return rc;
205 }
206
207 /*
208 * Release all memory associated with X.25 routing structures.
209 */
x25_route_free(void)210 void __exit x25_route_free(void)
211 {
212 struct x25_route *rt;
213 struct list_head *entry, *tmp;
214
215 write_lock_bh(&x25_route_list_lock);
216 list_for_each_safe(entry, tmp, &x25_route_list) {
217 rt = list_entry(entry, struct x25_route, node);
218 __x25_remove_route(rt);
219 }
220 write_unlock_bh(&x25_route_list_lock);
221 }
222