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/list.h>
26 #include <linux/mm.h>
27 #include <linux/interrupt.h>
28 #include <linux/init.h>
29
30 static LIST_HEAD(ax25_dev_list);
31 DEFINE_SPINLOCK(ax25_dev_lock);
32
ax25_addr_ax25dev(ax25_address * addr)33 ax25_dev *ax25_addr_ax25dev(ax25_address *addr)
34 {
35 ax25_dev *ax25_dev, *res = NULL;
36
37 spin_lock_bh(&ax25_dev_lock);
38 list_for_each_entry(ax25_dev, &ax25_dev_list, list)
39 if (ax25cmp(addr, (const ax25_address *)ax25_dev->dev->dev_addr) == 0) {
40 res = ax25_dev;
41 ax25_dev_hold(ax25_dev);
42 break;
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 */
ax25_dev_device_up(struct net_device * dev)53 void ax25_dev_device_up(struct net_device *dev)
54 {
55 ax25_dev *ax25_dev;
56
57 ax25_dev = kzalloc(sizeof(*ax25_dev), GFP_KERNEL);
58 if (!ax25_dev) {
59 printk(KERN_ERR "AX.25: ax25_dev_device_up - out of memory\n");
60 return;
61 }
62
63 refcount_set(&ax25_dev->refcount, 1);
64 ax25_dev->dev = dev;
65 netdev_hold(dev, &ax25_dev->dev_tracker, GFP_KERNEL);
66 ax25_dev->forward = NULL;
67 ax25_dev->device_up = true;
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 list_add(&ax25_dev->list, &ax25_dev_list);
90 dev->ax25_ptr = ax25_dev;
91 spin_unlock_bh(&ax25_dev_lock);
92
93 ax25_register_dev_sysctl(ax25_dev);
94 }
95
ax25_dev_device_down(struct net_device * dev)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_dev_sysctl(ax25_dev);
104
105 spin_lock_bh(&ax25_dev_lock);
106
107 #ifdef CONFIG_AX25_DAMA_SLAVE
108 timer_shutdown_sync(&ax25_dev->dama.slave_timer);
109 #endif
110
111 /*
112 * Remove any packet forwarding that points to this device.
113 */
114 list_for_each_entry(s, &ax25_dev_list, list)
115 if (s->forward == dev)
116 s->forward = NULL;
117
118 list_for_each_entry(s, &ax25_dev_list, list) {
119 if (s == ax25_dev) {
120 list_del(&s->list);
121 break;
122 }
123 }
124
125 dev->ax25_ptr = NULL;
126 spin_unlock_bh(&ax25_dev_lock);
127 netdev_put(dev, &ax25_dev->dev_tracker);
128 ax25_dev_put(ax25_dev);
129 }
130
ax25_fwd_ioctl(unsigned int cmd,struct ax25_fwd_struct * fwd)131 int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd)
132 {
133 ax25_dev *ax25_dev, *fwd_dev;
134
135 if ((ax25_dev = ax25_addr_ax25dev(&fwd->port_from)) == NULL)
136 return -EINVAL;
137
138 switch (cmd) {
139 case SIOCAX25ADDFWD:
140 fwd_dev = ax25_addr_ax25dev(&fwd->port_to);
141 if (!fwd_dev) {
142 ax25_dev_put(ax25_dev);
143 return -EINVAL;
144 }
145 if (ax25_dev->forward) {
146 ax25_dev_put(fwd_dev);
147 ax25_dev_put(ax25_dev);
148 return -EINVAL;
149 }
150 ax25_dev->forward = fwd_dev->dev;
151 ax25_dev_put(fwd_dev);
152 ax25_dev_put(ax25_dev);
153 break;
154
155 case SIOCAX25DELFWD:
156 if (!ax25_dev->forward) {
157 ax25_dev_put(ax25_dev);
158 return -EINVAL;
159 }
160 ax25_dev->forward = NULL;
161 ax25_dev_put(ax25_dev);
162 break;
163
164 default:
165 ax25_dev_put(ax25_dev);
166 return -EINVAL;
167 }
168
169 return 0;
170 }
171
ax25_fwd_dev(struct net_device * dev)172 struct net_device *ax25_fwd_dev(struct net_device *dev)
173 {
174 ax25_dev *ax25_dev;
175
176 if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
177 return dev;
178
179 if (ax25_dev->forward == NULL)
180 return dev;
181
182 return ax25_dev->forward;
183 }
184
185 /*
186 * Free all memory associated with device structures.
187 */
ax25_dev_free(void)188 void __exit ax25_dev_free(void)
189 {
190 ax25_dev *s, *n;
191
192 spin_lock_bh(&ax25_dev_lock);
193 list_for_each_entry_safe(s, n, &ax25_dev_list, list) {
194 netdev_put(s->dev, &s->dev_tracker);
195 list_del(&s->list);
196 ax25_dev_put(s);
197 }
198 spin_unlock_bh(&ax25_dev_lock);
199 }
200