xref: /openbmc/linux/net/ax25/ax25_dev.c (revision f3539c12)
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/slab.h>
13 #include <linux/in.h>
14 #include <linux/kernel.h>
15 #include <linux/timer.h>
16 #include <linux/string.h>
17 #include <linux/sockios.h>
18 #include <linux/net.h>
19 #include <linux/spinlock.h>
20 #include <net/ax25.h>
21 #include <linux/inet.h>
22 #include <linux/netdevice.h>
23 #include <linux/if_arp.h>
24 #include <linux/skbuff.h>
25 #include <net/sock.h>
26 #include <asm/uaccess.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 	dev->ax25_ptr     = ax25_dev;
63 	ax25_dev->dev     = dev;
64 	dev_hold(dev);
65 	ax25_dev->forward = NULL;
66 
67 	ax25_dev->values[AX25_VALUES_IPDEFMODE] = AX25_DEF_IPDEFMODE;
68 	ax25_dev->values[AX25_VALUES_AXDEFMODE] = AX25_DEF_AXDEFMODE;
69 	ax25_dev->values[AX25_VALUES_BACKOFF]   = AX25_DEF_BACKOFF;
70 	ax25_dev->values[AX25_VALUES_CONMODE]   = AX25_DEF_CONMODE;
71 	ax25_dev->values[AX25_VALUES_WINDOW]    = AX25_DEF_WINDOW;
72 	ax25_dev->values[AX25_VALUES_EWINDOW]   = AX25_DEF_EWINDOW;
73 	ax25_dev->values[AX25_VALUES_T1]        = AX25_DEF_T1;
74 	ax25_dev->values[AX25_VALUES_T2]        = AX25_DEF_T2;
75 	ax25_dev->values[AX25_VALUES_T3]        = AX25_DEF_T3;
76 	ax25_dev->values[AX25_VALUES_IDLE]	= AX25_DEF_IDLE;
77 	ax25_dev->values[AX25_VALUES_N2]        = AX25_DEF_N2;
78 	ax25_dev->values[AX25_VALUES_PACLEN]	= AX25_DEF_PACLEN;
79 	ax25_dev->values[AX25_VALUES_PROTOCOL]  = AX25_DEF_PROTOCOL;
80 	ax25_dev->values[AX25_VALUES_DS_TIMEOUT]= AX25_DEF_DS_TIMEOUT;
81 
82 #if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
83 	ax25_ds_setup_timer(ax25_dev);
84 #endif
85 
86 	spin_lock_bh(&ax25_dev_lock);
87 	ax25_dev->next = ax25_dev_list;
88 	ax25_dev_list  = ax25_dev;
89 	spin_unlock_bh(&ax25_dev_lock);
90 
91 	ax25_register_dev_sysctl(ax25_dev);
92 }
93 
94 void ax25_dev_device_down(struct net_device *dev)
95 {
96 	ax25_dev *s, *ax25_dev;
97 
98 	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
99 		return;
100 
101 	ax25_unregister_dev_sysctl(ax25_dev);
102 
103 	spin_lock_bh(&ax25_dev_lock);
104 
105 #ifdef CONFIG_AX25_DAMA_SLAVE
106 	ax25_ds_del_timer(ax25_dev);
107 #endif
108 
109 	/*
110 	 *	Remove any packet forwarding that points to this device.
111 	 */
112 	for (s = ax25_dev_list; s != NULL; s = s->next)
113 		if (s->forward == dev)
114 			s->forward = NULL;
115 
116 	if ((s = ax25_dev_list) == ax25_dev) {
117 		ax25_dev_list = s->next;
118 		spin_unlock_bh(&ax25_dev_lock);
119 		dev_put(dev);
120 		kfree(ax25_dev);
121 		return;
122 	}
123 
124 	while (s != NULL && s->next != NULL) {
125 		if (s->next == ax25_dev) {
126 			s->next = ax25_dev->next;
127 			spin_unlock_bh(&ax25_dev_lock);
128 			dev_put(dev);
129 			kfree(ax25_dev);
130 			return;
131 		}
132 
133 		s = s->next;
134 	}
135 	spin_unlock_bh(&ax25_dev_lock);
136 	dev->ax25_ptr = NULL;
137 }
138 
139 int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd)
140 {
141 	ax25_dev *ax25_dev, *fwd_dev;
142 
143 	if ((ax25_dev = ax25_addr_ax25dev(&fwd->port_from)) == NULL)
144 		return -EINVAL;
145 
146 	switch (cmd) {
147 	case SIOCAX25ADDFWD:
148 		if ((fwd_dev = ax25_addr_ax25dev(&fwd->port_to)) == NULL)
149 			return -EINVAL;
150 		if (ax25_dev->forward != NULL)
151 			return -EINVAL;
152 		ax25_dev->forward = fwd_dev->dev;
153 		break;
154 
155 	case SIOCAX25DELFWD:
156 		if (ax25_dev->forward == NULL)
157 			return -EINVAL;
158 		ax25_dev->forward = NULL;
159 		break;
160 
161 	default:
162 		return -EINVAL;
163 	}
164 
165 	return 0;
166 }
167 
168 struct net_device *ax25_fwd_dev(struct net_device *dev)
169 {
170 	ax25_dev *ax25_dev;
171 
172 	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
173 		return dev;
174 
175 	if (ax25_dev->forward == NULL)
176 		return dev;
177 
178 	return ax25_dev->forward;
179 }
180 
181 /*
182  *	Free all memory associated with device structures.
183  */
184 void __exit ax25_dev_free(void)
185 {
186 	ax25_dev *s, *ax25_dev;
187 
188 	spin_lock_bh(&ax25_dev_lock);
189 	ax25_dev = ax25_dev_list;
190 	while (ax25_dev != NULL) {
191 		s        = ax25_dev;
192 		dev_put(ax25_dev->dev);
193 		ax25_dev = ax25_dev->next;
194 		kfree(s);
195 	}
196 	ax25_dev_list = NULL;
197 	spin_unlock_bh(&ax25_dev_lock);
198 }
199