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_obj(*ax25_dev);
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
83 #ifdef CONFIG_AX25_DAMA_SLAVE
84 ax25_dev->values[AX25_VALUES_DS_TIMEOUT]= AX25_DEF_DS_TIMEOUT;
85
86 ax25_ds_setup_timer(ax25_dev);
87 #endif
88
89 spin_lock_bh(&ax25_dev_lock);
90 list_add(&ax25_dev->list, &ax25_dev_list);
91 rcu_assign_pointer(dev->ax25_ptr, ax25_dev);
92 spin_unlock_bh(&ax25_dev_lock);
93
94 ax25_register_dev_sysctl(ax25_dev);
95 }
96
ax25_dev_device_down(struct net_device * dev)97 void ax25_dev_device_down(struct net_device *dev)
98 {
99 ax25_dev *s, *ax25_dev;
100
101 if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
102 return;
103
104 ax25_unregister_dev_sysctl(ax25_dev);
105
106 spin_lock_bh(&ax25_dev_lock);
107
108 #ifdef CONFIG_AX25_DAMA_SLAVE
109 timer_shutdown_sync(&ax25_dev->dama.slave_timer);
110 #endif
111
112 /*
113 * Remove any packet forwarding that points to this device.
114 */
115 list_for_each_entry(s, &ax25_dev_list, list)
116 if (s->forward == dev)
117 s->forward = NULL;
118
119 list_for_each_entry(s, &ax25_dev_list, list) {
120 if (s == ax25_dev) {
121 list_del(&s->list);
122 break;
123 }
124 }
125
126 RCU_INIT_POINTER(dev->ax25_ptr, NULL);
127 spin_unlock_bh(&ax25_dev_lock);
128 netdev_put(dev, &ax25_dev->dev_tracker);
129 ax25_dev_put(ax25_dev);
130 }
131
ax25_fwd_ioctl(unsigned int cmd,struct ax25_fwd_struct * fwd)132 int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd)
133 {
134 ax25_dev *ax25_dev, *fwd_dev;
135
136 if ((ax25_dev = ax25_addr_ax25dev(&fwd->port_from)) == NULL)
137 return -EINVAL;
138
139 switch (cmd) {
140 case SIOCAX25ADDFWD:
141 fwd_dev = ax25_addr_ax25dev(&fwd->port_to);
142 if (!fwd_dev) {
143 ax25_dev_put(ax25_dev);
144 return -EINVAL;
145 }
146 if (ax25_dev->forward) {
147 ax25_dev_put(fwd_dev);
148 ax25_dev_put(ax25_dev);
149 return -EINVAL;
150 }
151 ax25_dev->forward = fwd_dev->dev;
152 ax25_dev_put(fwd_dev);
153 ax25_dev_put(ax25_dev);
154 break;
155
156 case SIOCAX25DELFWD:
157 if (!ax25_dev->forward) {
158 ax25_dev_put(ax25_dev);
159 return -EINVAL;
160 }
161 ax25_dev->forward = NULL;
162 ax25_dev_put(ax25_dev);
163 break;
164
165 default:
166 ax25_dev_put(ax25_dev);
167 return -EINVAL;
168 }
169
170 return 0;
171 }
172
ax25_fwd_dev(struct net_device * dev)173 struct net_device *ax25_fwd_dev(struct net_device *dev)
174 {
175 ax25_dev *ax25_dev;
176
177 if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
178 return dev;
179
180 if (ax25_dev->forward == NULL)
181 return dev;
182
183 return ax25_dev->forward;
184 }
185
186 /*
187 * Free all memory associated with device structures.
188 */
ax25_dev_free(void)189 void __exit ax25_dev_free(void)
190 {
191 ax25_dev *s, *n;
192
193 spin_lock_bh(&ax25_dev_lock);
194 list_for_each_entry_safe(s, n, &ax25_dev_list, list) {
195 netdev_put(s->dev, &s->dev_tracker);
196 list_del(&s->list);
197 ax25_dev_put(s);
198 }
199 spin_unlock_bh(&ax25_dev_lock);
200 }
201