xref: /openbmc/linux/net/ax25/ax25_dev.c (revision 1da177e4)
1 /*
2  * This program is free software; you can redistribute it and/or modify
3  * it under the terms of the GNU General Public License as published by
4  * the Free Software Foundation; either version 2 of the License, or
5  * (at your option) any later version.
6  *
7  * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
8  */
9 #include <linux/config.h>
10 #include <linux/errno.h>
11 #include <linux/types.h>
12 #include <linux/socket.h>
13 #include <linux/in.h>
14 #include <linux/kernel.h>
15 #include <linux/sched.h>
16 #include <linux/timer.h>
17 #include <linux/string.h>
18 #include <linux/sockios.h>
19 #include <linux/net.h>
20 #include <linux/spinlock.h>
21 #include <net/ax25.h>
22 #include <linux/inet.h>
23 #include <linux/netdevice.h>
24 #include <linux/if_arp.h>
25 #include <linux/skbuff.h>
26 #include <net/sock.h>
27 #include <asm/uaccess.h>
28 #include <asm/system.h>
29 #include <linux/fcntl.h>
30 #include <linux/mm.h>
31 #include <linux/interrupt.h>
32 #include <linux/init.h>
33 
34 ax25_dev *ax25_dev_list;
35 DEFINE_SPINLOCK(ax25_dev_lock);
36 
37 ax25_dev *ax25_addr_ax25dev(ax25_address *addr)
38 {
39 	ax25_dev *ax25_dev, *res = NULL;
40 
41 	spin_lock_bh(&ax25_dev_lock);
42 	for (ax25_dev = ax25_dev_list; ax25_dev != NULL; ax25_dev = ax25_dev->next)
43 		if (ax25cmp(addr, (ax25_address *)ax25_dev->dev->dev_addr) == 0) {
44 			res = ax25_dev;
45 		}
46 	spin_unlock_bh(&ax25_dev_lock);
47 
48 	return res;
49 }
50 
51 /*
52  *	This is called when an interface is brought up. These are
53  *	reasonable defaults.
54  */
55 void ax25_dev_device_up(struct net_device *dev)
56 {
57 	ax25_dev *ax25_dev;
58 
59 	if ((ax25_dev = kmalloc(sizeof(*ax25_dev), GFP_ATOMIC)) == NULL) {
60 		printk(KERN_ERR "AX.25: ax25_dev_device_up - out of memory\n");
61 		return;
62 	}
63 
64 	ax25_unregister_sysctl();
65 
66 	memset(ax25_dev, 0x00, sizeof(*ax25_dev));
67 
68 	dev->ax25_ptr     = ax25_dev;
69 	ax25_dev->dev     = dev;
70 	dev_hold(dev);
71 	ax25_dev->forward = NULL;
72 
73 	ax25_dev->values[AX25_VALUES_IPDEFMODE] = AX25_DEF_IPDEFMODE;
74 	ax25_dev->values[AX25_VALUES_AXDEFMODE] = AX25_DEF_AXDEFMODE;
75 	ax25_dev->values[AX25_VALUES_BACKOFF]   = AX25_DEF_BACKOFF;
76 	ax25_dev->values[AX25_VALUES_CONMODE]   = AX25_DEF_CONMODE;
77 	ax25_dev->values[AX25_VALUES_WINDOW]    = AX25_DEF_WINDOW;
78 	ax25_dev->values[AX25_VALUES_EWINDOW]   = AX25_DEF_EWINDOW;
79 	ax25_dev->values[AX25_VALUES_T1]        = AX25_DEF_T1;
80 	ax25_dev->values[AX25_VALUES_T2]        = AX25_DEF_T2;
81 	ax25_dev->values[AX25_VALUES_T3]        = AX25_DEF_T3;
82 	ax25_dev->values[AX25_VALUES_IDLE]	= AX25_DEF_IDLE;
83 	ax25_dev->values[AX25_VALUES_N2]        = AX25_DEF_N2;
84 	ax25_dev->values[AX25_VALUES_PACLEN]	= AX25_DEF_PACLEN;
85 	ax25_dev->values[AX25_VALUES_PROTOCOL]  = AX25_DEF_PROTOCOL;
86 	ax25_dev->values[AX25_VALUES_DS_TIMEOUT]= AX25_DEF_DS_TIMEOUT;
87 
88 #if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
89 	init_timer(&ax25_dev->dama.slave_timer);
90 #endif
91 
92 	spin_lock_bh(&ax25_dev_lock);
93 	ax25_dev->next = ax25_dev_list;
94 	ax25_dev_list  = ax25_dev;
95 	spin_unlock_bh(&ax25_dev_lock);
96 
97 	ax25_register_sysctl();
98 }
99 
100 void ax25_dev_device_down(struct net_device *dev)
101 {
102 	ax25_dev *s, *ax25_dev;
103 
104 	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
105 		return;
106 
107 	ax25_unregister_sysctl();
108 
109 	spin_lock_bh(&ax25_dev_lock);
110 
111 #ifdef CONFIG_AX25_DAMA_SLAVE
112 	ax25_ds_del_timer(ax25_dev);
113 #endif
114 
115 	/*
116 	 *	Remove any packet forwarding that points to this device.
117 	 */
118 	for (s = ax25_dev_list; s != NULL; s = s->next)
119 		if (s->forward == dev)
120 			s->forward = NULL;
121 
122 	if ((s = ax25_dev_list) == ax25_dev) {
123 		ax25_dev_list = s->next;
124 		spin_unlock_bh(&ax25_dev_lock);
125 		dev_put(dev);
126 		kfree(ax25_dev);
127 		ax25_register_sysctl();
128 		return;
129 	}
130 
131 	while (s != NULL && s->next != NULL) {
132 		if (s->next == ax25_dev) {
133 			s->next = ax25_dev->next;
134 			spin_unlock_bh(&ax25_dev_lock);
135 			dev_put(dev);
136 			kfree(ax25_dev);
137 			ax25_register_sysctl();
138 			return;
139 		}
140 
141 		s = s->next;
142 	}
143 	spin_unlock_bh(&ax25_dev_lock);
144 	dev->ax25_ptr = NULL;
145 
146 	ax25_register_sysctl();
147 }
148 
149 int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd)
150 {
151 	ax25_dev *ax25_dev, *fwd_dev;
152 
153 	if ((ax25_dev = ax25_addr_ax25dev(&fwd->port_from)) == NULL)
154 		return -EINVAL;
155 
156 	switch (cmd) {
157 	case SIOCAX25ADDFWD:
158 		if ((fwd_dev = ax25_addr_ax25dev(&fwd->port_to)) == NULL)
159 			return -EINVAL;
160 		if (ax25_dev->forward != NULL)
161 			return -EINVAL;
162 		ax25_dev->forward = fwd_dev->dev;
163 		break;
164 
165 	case SIOCAX25DELFWD:
166 		if (ax25_dev->forward == NULL)
167 			return -EINVAL;
168 		ax25_dev->forward = NULL;
169 		break;
170 
171 	default:
172 		return -EINVAL;
173 	}
174 
175 	return 0;
176 }
177 
178 struct net_device *ax25_fwd_dev(struct net_device *dev)
179 {
180 	ax25_dev *ax25_dev;
181 
182 	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
183 		return dev;
184 
185 	if (ax25_dev->forward == NULL)
186 		return dev;
187 
188 	return ax25_dev->forward;
189 }
190 
191 /*
192  *	Free all memory associated with device structures.
193  */
194 void __exit ax25_dev_free(void)
195 {
196 	ax25_dev *s, *ax25_dev;
197 
198 	spin_lock_bh(&ax25_dev_lock);
199 	ax25_dev = ax25_dev_list;
200 	while (ax25_dev != NULL) {
201 		s        = ax25_dev;
202 		dev_put(ax25_dev->dev);
203 		ax25_dev = ax25_dev->next;
204 		kfree(s);
205 	}
206 	ax25_dev_list = NULL;
207 	spin_unlock_bh(&ax25_dev_lock);
208 }
209