xref: /openbmc/linux/net/ax25/ax25_dev.c (revision 22246614)
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/errno.h>
10 #include <linux/types.h>
11 #include <linux/socket.h>
12 #include <linux/in.h>
13 #include <linux/kernel.h>
14 #include <linux/timer.h>
15 #include <linux/string.h>
16 #include <linux/sockios.h>
17 #include <linux/net.h>
18 #include <linux/spinlock.h>
19 #include <net/ax25.h>
20 #include <linux/inet.h>
21 #include <linux/netdevice.h>
22 #include <linux/if_arp.h>
23 #include <linux/skbuff.h>
24 #include <net/sock.h>
25 #include <asm/uaccess.h>
26 #include <asm/system.h>
27 #include <linux/fcntl.h>
28 #include <linux/mm.h>
29 #include <linux/interrupt.h>
30 #include <linux/init.h>
31 
32 ax25_dev *ax25_dev_list;
33 DEFINE_SPINLOCK(ax25_dev_lock);
34 
35 ax25_dev *ax25_addr_ax25dev(ax25_address *addr)
36 {
37 	ax25_dev *ax25_dev, *res = NULL;
38 
39 	spin_lock_bh(&ax25_dev_lock);
40 	for (ax25_dev = ax25_dev_list; ax25_dev != NULL; ax25_dev = ax25_dev->next)
41 		if (ax25cmp(addr, (ax25_address *)ax25_dev->dev->dev_addr) == 0) {
42 			res = ax25_dev;
43 		}
44 	spin_unlock_bh(&ax25_dev_lock);
45 
46 	return res;
47 }
48 
49 /*
50  *	This is called when an interface is brought up. These are
51  *	reasonable defaults.
52  */
53 void ax25_dev_device_up(struct net_device *dev)
54 {
55 	ax25_dev *ax25_dev;
56 
57 	if ((ax25_dev = kzalloc(sizeof(*ax25_dev), GFP_ATOMIC)) == NULL) {
58 		printk(KERN_ERR "AX.25: ax25_dev_device_up - out of memory\n");
59 		return;
60 	}
61 
62 	ax25_unregister_sysctl();
63 
64 	dev->ax25_ptr     = ax25_dev;
65 	ax25_dev->dev     = dev;
66 	dev_hold(dev);
67 	ax25_dev->forward = NULL;
68 
69 	ax25_dev->values[AX25_VALUES_IPDEFMODE] = AX25_DEF_IPDEFMODE;
70 	ax25_dev->values[AX25_VALUES_AXDEFMODE] = AX25_DEF_AXDEFMODE;
71 	ax25_dev->values[AX25_VALUES_BACKOFF]   = AX25_DEF_BACKOFF;
72 	ax25_dev->values[AX25_VALUES_CONMODE]   = AX25_DEF_CONMODE;
73 	ax25_dev->values[AX25_VALUES_WINDOW]    = AX25_DEF_WINDOW;
74 	ax25_dev->values[AX25_VALUES_EWINDOW]   = AX25_DEF_EWINDOW;
75 	ax25_dev->values[AX25_VALUES_T1]        = AX25_DEF_T1;
76 	ax25_dev->values[AX25_VALUES_T2]        = AX25_DEF_T2;
77 	ax25_dev->values[AX25_VALUES_T3]        = AX25_DEF_T3;
78 	ax25_dev->values[AX25_VALUES_IDLE]	= AX25_DEF_IDLE;
79 	ax25_dev->values[AX25_VALUES_N2]        = AX25_DEF_N2;
80 	ax25_dev->values[AX25_VALUES_PACLEN]	= AX25_DEF_PACLEN;
81 	ax25_dev->values[AX25_VALUES_PROTOCOL]  = AX25_DEF_PROTOCOL;
82 	ax25_dev->values[AX25_VALUES_DS_TIMEOUT]= AX25_DEF_DS_TIMEOUT;
83 
84 #if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
85 	ax25_ds_setup_timer(ax25_dev);
86 #endif
87 
88 	spin_lock_bh(&ax25_dev_lock);
89 	ax25_dev->next = ax25_dev_list;
90 	ax25_dev_list  = ax25_dev;
91 	spin_unlock_bh(&ax25_dev_lock);
92 
93 	ax25_register_sysctl();
94 }
95 
96 void ax25_dev_device_down(struct net_device *dev)
97 {
98 	ax25_dev *s, *ax25_dev;
99 
100 	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
101 		return;
102 
103 	ax25_unregister_sysctl();
104 
105 	spin_lock_bh(&ax25_dev_lock);
106 
107 #ifdef CONFIG_AX25_DAMA_SLAVE
108 	ax25_ds_del_timer(ax25_dev);
109 #endif
110 
111 	/*
112 	 *	Remove any packet forwarding that points to this device.
113 	 */
114 	for (s = ax25_dev_list; s != NULL; s = s->next)
115 		if (s->forward == dev)
116 			s->forward = NULL;
117 
118 	if ((s = ax25_dev_list) == ax25_dev) {
119 		ax25_dev_list = s->next;
120 		spin_unlock_bh(&ax25_dev_lock);
121 		dev_put(dev);
122 		kfree(ax25_dev);
123 		ax25_register_sysctl();
124 		return;
125 	}
126 
127 	while (s != NULL && s->next != NULL) {
128 		if (s->next == ax25_dev) {
129 			s->next = ax25_dev->next;
130 			spin_unlock_bh(&ax25_dev_lock);
131 			dev_put(dev);
132 			kfree(ax25_dev);
133 			ax25_register_sysctl();
134 			return;
135 		}
136 
137 		s = s->next;
138 	}
139 	spin_unlock_bh(&ax25_dev_lock);
140 	dev->ax25_ptr = NULL;
141 
142 	ax25_register_sysctl();
143 }
144 
145 int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd)
146 {
147 	ax25_dev *ax25_dev, *fwd_dev;
148 
149 	if ((ax25_dev = ax25_addr_ax25dev(&fwd->port_from)) == NULL)
150 		return -EINVAL;
151 
152 	switch (cmd) {
153 	case SIOCAX25ADDFWD:
154 		if ((fwd_dev = ax25_addr_ax25dev(&fwd->port_to)) == NULL)
155 			return -EINVAL;
156 		if (ax25_dev->forward != NULL)
157 			return -EINVAL;
158 		ax25_dev->forward = fwd_dev->dev;
159 		break;
160 
161 	case SIOCAX25DELFWD:
162 		if (ax25_dev->forward == NULL)
163 			return -EINVAL;
164 		ax25_dev->forward = NULL;
165 		break;
166 
167 	default:
168 		return -EINVAL;
169 	}
170 
171 	return 0;
172 }
173 
174 struct net_device *ax25_fwd_dev(struct net_device *dev)
175 {
176 	ax25_dev *ax25_dev;
177 
178 	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
179 		return dev;
180 
181 	if (ax25_dev->forward == NULL)
182 		return dev;
183 
184 	return ax25_dev->forward;
185 }
186 
187 /*
188  *	Free all memory associated with device structures.
189  */
190 void __exit ax25_dev_free(void)
191 {
192 	ax25_dev *s, *ax25_dev;
193 
194 	spin_lock_bh(&ax25_dev_lock);
195 	ax25_dev = ax25_dev_list;
196 	while (ax25_dev != NULL) {
197 		s        = ax25_dev;
198 		dev_put(ax25_dev->dev);
199 		ax25_dev = ax25_dev->next;
200 		kfree(s);
201 	}
202 	ax25_dev_list = NULL;
203 	spin_unlock_bh(&ax25_dev_lock);
204 }
205