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, (const ax25_address *)ax25_dev->dev->dev_addr) == 0) {
39 res = ax25_dev;
40 ax25_dev_hold(ax25_dev);
41 }
42 spin_unlock_bh(&ax25_dev_lock);
43
44 return res;
45 }
46
47 /*
48 * This is called when an interface is brought up. These are
49 * reasonable defaults.
50 */
ax25_dev_device_up(struct net_device * dev)51 void ax25_dev_device_up(struct net_device *dev)
52 {
53 ax25_dev *ax25_dev;
54
55 if ((ax25_dev = kzalloc(sizeof(*ax25_dev), GFP_ATOMIC)) == NULL) {
56 printk(KERN_ERR "AX.25: ax25_dev_device_up - out of memory\n");
57 return;
58 }
59
60 refcount_set(&ax25_dev->refcount, 1);
61 dev->ax25_ptr = ax25_dev;
62 ax25_dev->dev = dev;
63 dev_hold_track(dev, &ax25_dev->dev_tracker, GFP_ATOMIC);
64 ax25_dev->forward = NULL;
65 ax25_dev->device_up = true;
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 ax25_dev_hold(ax25_dev);
91
92 ax25_register_dev_sysctl(ax25_dev);
93 }
94
ax25_dev_device_down(struct net_device * dev)95 void ax25_dev_device_down(struct net_device *dev)
96 {
97 ax25_dev *s, *ax25_dev;
98
99 if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
100 return;
101
102 ax25_unregister_dev_sysctl(ax25_dev);
103
104 spin_lock_bh(&ax25_dev_lock);
105
106 #ifdef CONFIG_AX25_DAMA_SLAVE
107 ax25_ds_del_timer(ax25_dev);
108 #endif
109
110 /*
111 * Remove any packet forwarding that points to this device.
112 */
113 for (s = ax25_dev_list; s != NULL; s = s->next)
114 if (s->forward == dev)
115 s->forward = NULL;
116
117 if ((s = ax25_dev_list) == ax25_dev) {
118 ax25_dev_list = s->next;
119 goto unlock_put;
120 }
121
122 while (s != NULL && s->next != NULL) {
123 if (s->next == ax25_dev) {
124 s->next = ax25_dev->next;
125 goto unlock_put;
126 }
127
128 s = s->next;
129 }
130 spin_unlock_bh(&ax25_dev_lock);
131 dev->ax25_ptr = NULL;
132 ax25_dev_put(ax25_dev);
133 return;
134
135 unlock_put:
136 spin_unlock_bh(&ax25_dev_lock);
137 ax25_dev_put(ax25_dev);
138 dev->ax25_ptr = NULL;
139 dev_put_track(dev, &ax25_dev->dev_tracker);
140 ax25_dev_put(ax25_dev);
141 }
142
ax25_fwd_ioctl(unsigned int cmd,struct ax25_fwd_struct * fwd)143 int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd)
144 {
145 ax25_dev *ax25_dev, *fwd_dev;
146
147 if ((ax25_dev = ax25_addr_ax25dev(&fwd->port_from)) == NULL)
148 return -EINVAL;
149
150 switch (cmd) {
151 case SIOCAX25ADDFWD:
152 fwd_dev = ax25_addr_ax25dev(&fwd->port_to);
153 if (!fwd_dev) {
154 ax25_dev_put(ax25_dev);
155 return -EINVAL;
156 }
157 if (ax25_dev->forward) {
158 ax25_dev_put(fwd_dev);
159 ax25_dev_put(ax25_dev);
160 return -EINVAL;
161 }
162 ax25_dev->forward = fwd_dev->dev;
163 ax25_dev_put(fwd_dev);
164 ax25_dev_put(ax25_dev);
165 break;
166
167 case SIOCAX25DELFWD:
168 if (!ax25_dev->forward) {
169 ax25_dev_put(ax25_dev);
170 return -EINVAL;
171 }
172 ax25_dev->forward = NULL;
173 ax25_dev_put(ax25_dev);
174 break;
175
176 default:
177 ax25_dev_put(ax25_dev);
178 return -EINVAL;
179 }
180
181 return 0;
182 }
183
ax25_fwd_dev(struct net_device * dev)184 struct net_device *ax25_fwd_dev(struct net_device *dev)
185 {
186 ax25_dev *ax25_dev;
187
188 if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
189 return dev;
190
191 if (ax25_dev->forward == NULL)
192 return dev;
193
194 return ax25_dev->forward;
195 }
196
197 /*
198 * Free all memory associated with device structures.
199 */
ax25_dev_free(void)200 void __exit ax25_dev_free(void)
201 {
202 ax25_dev *s, *ax25_dev;
203
204 spin_lock_bh(&ax25_dev_lock);
205 ax25_dev = ax25_dev_list;
206 while (ax25_dev != NULL) {
207 s = ax25_dev;
208 dev_put_track(ax25_dev->dev, &ax25_dev->dev_tracker);
209 ax25_dev = ax25_dev->next;
210 kfree(s);
211 }
212 ax25_dev_list = NULL;
213 spin_unlock_bh(&ax25_dev_lock);
214 }
215