1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *
4  * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
5  */
6 #include <linux/errno.h>
7 #include <linux/types.h>
8 #include <linux/socket.h>
9 #include <linux/slab.h>
10 #include <linux/in.h>
11 #include <linux/kernel.h>
12 #include <linux/timer.h>
13 #include <linux/string.h>
14 #include <linux/sockios.h>
15 #include <linux/net.h>
16 #include <linux/spinlock.h>
17 #include <net/ax25.h>
18 #include <linux/inet.h>
19 #include <linux/netdevice.h>
20 #include <linux/if_arp.h>
21 #include <linux/skbuff.h>
22 #include <net/sock.h>
23 #include <linux/uaccess.h>
24 #include <linux/fcntl.h>
25 #include <linux/mm.h>
26 #include <linux/interrupt.h>
27 #include <linux/init.h>
28 
29 ax25_dev *ax25_dev_list;
30 DEFINE_SPINLOCK(ax25_dev_lock);
31 
ax25_addr_ax25dev(ax25_address * addr)32 ax25_dev *ax25_addr_ax25dev(ax25_address *addr)
33 {
34 	ax25_dev *ax25_dev, *res = NULL;
35 
36 	spin_lock_bh(&ax25_dev_lock);
37 	for (ax25_dev = ax25_dev_list; ax25_dev != NULL; ax25_dev = ax25_dev->next)
38 		if (ax25cmp(addr, (ax25_address *)ax25_dev->dev->dev_addr) == 0) {
39 			res = ax25_dev;
40 		}
41 	spin_unlock_bh(&ax25_dev_lock);
42 
43 	return res;
44 }
45 
46 /*
47  *	This is called when an interface is brought up. These are
48  *	reasonable defaults.
49  */
ax25_dev_device_up(struct net_device * dev)50 void ax25_dev_device_up(struct net_device *dev)
51 {
52 	ax25_dev *ax25_dev;
53 
54 	if ((ax25_dev = kzalloc(sizeof(*ax25_dev), GFP_ATOMIC)) == NULL) {
55 		printk(KERN_ERR "AX.25: ax25_dev_device_up - out of memory\n");
56 		return;
57 	}
58 
59 	dev->ax25_ptr     = ax25_dev;
60 	ax25_dev->dev     = dev;
61 	dev_hold(dev);
62 	ax25_dev->forward = NULL;
63 
64 	ax25_dev->values[AX25_VALUES_IPDEFMODE] = AX25_DEF_IPDEFMODE;
65 	ax25_dev->values[AX25_VALUES_AXDEFMODE] = AX25_DEF_AXDEFMODE;
66 	ax25_dev->values[AX25_VALUES_BACKOFF]   = AX25_DEF_BACKOFF;
67 	ax25_dev->values[AX25_VALUES_CONMODE]   = AX25_DEF_CONMODE;
68 	ax25_dev->values[AX25_VALUES_WINDOW]    = AX25_DEF_WINDOW;
69 	ax25_dev->values[AX25_VALUES_EWINDOW]   = AX25_DEF_EWINDOW;
70 	ax25_dev->values[AX25_VALUES_T1]        = AX25_DEF_T1;
71 	ax25_dev->values[AX25_VALUES_T2]        = AX25_DEF_T2;
72 	ax25_dev->values[AX25_VALUES_T3]        = AX25_DEF_T3;
73 	ax25_dev->values[AX25_VALUES_IDLE]	= AX25_DEF_IDLE;
74 	ax25_dev->values[AX25_VALUES_N2]        = AX25_DEF_N2;
75 	ax25_dev->values[AX25_VALUES_PACLEN]	= AX25_DEF_PACLEN;
76 	ax25_dev->values[AX25_VALUES_PROTOCOL]  = AX25_DEF_PROTOCOL;
77 	ax25_dev->values[AX25_VALUES_DS_TIMEOUT]= AX25_DEF_DS_TIMEOUT;
78 
79 #if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
80 	ax25_ds_setup_timer(ax25_dev);
81 #endif
82 
83 	spin_lock_bh(&ax25_dev_lock);
84 	ax25_dev->next = ax25_dev_list;
85 	ax25_dev_list  = ax25_dev;
86 	spin_unlock_bh(&ax25_dev_lock);
87 
88 	ax25_register_dev_sysctl(ax25_dev);
89 }
90 
ax25_dev_device_down(struct net_device * dev)91 void ax25_dev_device_down(struct net_device *dev)
92 {
93 	ax25_dev *s, *ax25_dev;
94 
95 	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
96 		return;
97 
98 	ax25_unregister_dev_sysctl(ax25_dev);
99 
100 	spin_lock_bh(&ax25_dev_lock);
101 
102 #ifdef CONFIG_AX25_DAMA_SLAVE
103 	ax25_ds_del_timer(ax25_dev);
104 #endif
105 
106 	/*
107 	 *	Remove any packet forwarding that points to this device.
108 	 */
109 	for (s = ax25_dev_list; s != NULL; s = s->next)
110 		if (s->forward == dev)
111 			s->forward = NULL;
112 
113 	if ((s = ax25_dev_list) == ax25_dev) {
114 		ax25_dev_list = s->next;
115 		spin_unlock_bh(&ax25_dev_lock);
116 		dev->ax25_ptr = NULL;
117 		dev_put(dev);
118 		kfree(ax25_dev);
119 		return;
120 	}
121 
122 	while (s != NULL && s->next != NULL) {
123 		if (s->next == ax25_dev) {
124 			s->next = ax25_dev->next;
125 			spin_unlock_bh(&ax25_dev_lock);
126 			dev->ax25_ptr = NULL;
127 			dev_put(dev);
128 			kfree(ax25_dev);
129 			return;
130 		}
131 
132 		s = s->next;
133 	}
134 	spin_unlock_bh(&ax25_dev_lock);
135 	dev->ax25_ptr = NULL;
136 }
137 
ax25_fwd_ioctl(unsigned int cmd,struct ax25_fwd_struct * fwd)138 int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd)
139 {
140 	ax25_dev *ax25_dev, *fwd_dev;
141 
142 	if ((ax25_dev = ax25_addr_ax25dev(&fwd->port_from)) == NULL)
143 		return -EINVAL;
144 
145 	switch (cmd) {
146 	case SIOCAX25ADDFWD:
147 		if ((fwd_dev = ax25_addr_ax25dev(&fwd->port_to)) == NULL)
148 			return -EINVAL;
149 		if (ax25_dev->forward != NULL)
150 			return -EINVAL;
151 		ax25_dev->forward = fwd_dev->dev;
152 		break;
153 
154 	case SIOCAX25DELFWD:
155 		if (ax25_dev->forward == NULL)
156 			return -EINVAL;
157 		ax25_dev->forward = NULL;
158 		break;
159 
160 	default:
161 		return -EINVAL;
162 	}
163 
164 	return 0;
165 }
166 
ax25_fwd_dev(struct net_device * dev)167 struct net_device *ax25_fwd_dev(struct net_device *dev)
168 {
169 	ax25_dev *ax25_dev;
170 
171 	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
172 		return dev;
173 
174 	if (ax25_dev->forward == NULL)
175 		return dev;
176 
177 	return ax25_dev->forward;
178 }
179 
180 /*
181  *	Free all memory associated with device structures.
182  */
ax25_dev_free(void)183 void __exit ax25_dev_free(void)
184 {
185 	ax25_dev *s, *ax25_dev;
186 
187 	spin_lock_bh(&ax25_dev_lock);
188 	ax25_dev = ax25_dev_list;
189 	while (ax25_dev != NULL) {
190 		s        = ax25_dev;
191 		dev_put(ax25_dev->dev);
192 		ax25_dev = ax25_dev->next;
193 		kfree(s);
194 	}
195 	ax25_dev_list = NULL;
196 	spin_unlock_bh(&ax25_dev_lock);
197 }
198