xref: /openbmc/linux/net/x25/x25_route.c (revision bc831fac)
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 	int rc = -EINVAL;
31 
32 	write_lock_bh(&x25_route_list_lock);
33 
34 	list_for_each_entry(rt, &x25_route_list, node) {
35 		if (!memcmp(&rt->address, address, sigdigits) &&
36 		    rt->sigdigits == sigdigits)
37 			goto out;
38 	}
39 
40 	rt = kmalloc(sizeof(*rt), GFP_ATOMIC);
41 	rc = -ENOMEM;
42 	if (!rt)
43 		goto out;
44 
45 	strcpy(rt->address.x25_addr, "000000000000000");
46 	memcpy(rt->address.x25_addr, address->x25_addr, sigdigits);
47 
48 	rt->sigdigits = sigdigits;
49 	rt->dev       = dev;
50 	refcount_set(&rt->refcnt, 1);
51 
52 	list_add(&rt->node, &x25_route_list);
53 	rc = 0;
54 out:
55 	write_unlock_bh(&x25_route_list_lock);
56 	return rc;
57 }
58 
59 /**
60  * __x25_remove_route - remove route from x25_route_list
61  * @rt: route to remove
62  *
63  * Remove route from x25_route_list. If it was there.
64  * Caller must hold x25_route_list_lock.
65  */
__x25_remove_route(struct x25_route * rt)66 static void __x25_remove_route(struct x25_route *rt)
67 {
68 	if (rt->node.next) {
69 		list_del(&rt->node);
70 		x25_route_put(rt);
71 	}
72 }
73 
x25_del_route(struct x25_address * address,unsigned int sigdigits,struct net_device * dev)74 static int x25_del_route(struct x25_address *address, unsigned int sigdigits,
75 			 struct net_device *dev)
76 {
77 	struct x25_route *rt;
78 	int rc = -EINVAL;
79 
80 	write_lock_bh(&x25_route_list_lock);
81 
82 	list_for_each_entry(rt, &x25_route_list, node) {
83 		if (!memcmp(&rt->address, address, sigdigits) &&
84 		    rt->sigdigits == sigdigits && rt->dev == dev) {
85 			__x25_remove_route(rt);
86 			rc = 0;
87 			break;
88 		}
89 	}
90 
91 	write_unlock_bh(&x25_route_list_lock);
92 	return rc;
93 }
94 
95 /*
96  *	A device has been removed, remove its routes.
97  */
x25_route_device_down(struct net_device * dev)98 void x25_route_device_down(struct net_device *dev)
99 {
100 	struct x25_route *rt;
101 	struct list_head *entry, *tmp;
102 
103 	write_lock_bh(&x25_route_list_lock);
104 
105 	list_for_each_safe(entry, tmp, &x25_route_list) {
106 		rt = list_entry(entry, struct x25_route, node);
107 
108 		if (rt->dev == dev)
109 			__x25_remove_route(rt);
110 	}
111 	write_unlock_bh(&x25_route_list_lock);
112 }
113 
114 /*
115  *	Check that the device given is a valid X.25 interface that is "up".
116  */
x25_dev_get(char * devname)117 struct net_device *x25_dev_get(char *devname)
118 {
119 	struct net_device *dev = dev_get_by_name(&init_net, devname);
120 
121 	if (dev && (!(dev->flags & IFF_UP) || dev->type != ARPHRD_X25)) {
122 		dev_put(dev);
123 		dev = NULL;
124 	}
125 
126 	return dev;
127 }
128 
129 /**
130  * 	x25_get_route -	Find a route given an X.25 address.
131  *	@addr: - address to find a route for
132  *
133  * 	Find a route given an X.25 address.
134  */
x25_get_route(struct x25_address * addr)135 struct x25_route *x25_get_route(struct x25_address *addr)
136 {
137 	struct x25_route *rt, *use = NULL;
138 
139 	read_lock_bh(&x25_route_list_lock);
140 
141 	list_for_each_entry(rt, &x25_route_list, node) {
142 		if (!memcmp(&rt->address, addr, rt->sigdigits)) {
143 			if (!use)
144 				use = rt;
145 			else if (rt->sigdigits > use->sigdigits)
146 				use = rt;
147 		}
148 	}
149 
150 	if (use)
151 		x25_route_hold(use);
152 
153 	read_unlock_bh(&x25_route_list_lock);
154 	return use;
155 }
156 
157 /*
158  *	Handle the ioctls that control the routing functions.
159  */
x25_route_ioctl(unsigned int cmd,void __user * arg)160 int x25_route_ioctl(unsigned int cmd, void __user *arg)
161 {
162 	struct x25_route_struct rt;
163 	struct net_device *dev;
164 	int rc = -EINVAL;
165 
166 	if (cmd != SIOCADDRT && cmd != SIOCDELRT)
167 		goto out;
168 
169 	rc = -EFAULT;
170 	if (copy_from_user(&rt, arg, sizeof(rt)))
171 		goto out;
172 
173 	rc = -EINVAL;
174 	if (rt.sigdigits > 15)
175 		goto out;
176 
177 	dev = x25_dev_get(rt.device);
178 	if (!dev)
179 		goto out;
180 
181 	if (cmd == SIOCADDRT)
182 		rc = x25_add_route(&rt.address, rt.sigdigits, dev);
183 	else
184 		rc = x25_del_route(&rt.address, rt.sigdigits, dev);
185 	dev_put(dev);
186 out:
187 	return rc;
188 }
189 
190 /*
191  *	Release all memory associated with X.25 routing structures.
192  */
x25_route_free(void)193 void __exit x25_route_free(void)
194 {
195 	struct x25_route *rt;
196 	struct list_head *entry, *tmp;
197 
198 	write_lock_bh(&x25_route_list_lock);
199 	list_for_each_safe(entry, tmp, &x25_route_list) {
200 		rt = list_entry(entry, struct x25_route, node);
201 		__x25_remove_route(rt);
202 	}
203 	write_unlock_bh(&x25_route_list_lock);
204 }
205