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
30static LIST_HEAD(ax25_dev_list);
31DEFINE_SPINLOCK(ax25_dev_lock);
32
33ax25_dev *ax25_addr_ax25dev(ax25_address *addr)
34{
35 ax25_dev *ax25_dev, *res = NULL;
36
37 spin_lock_bh(lock: &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(lock: &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 */
53void 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(r: &ax25_dev->refcount, n: 1);
64 ax25_dev->dev = dev;
65 netdev_hold(dev, tracker: &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#endif
86
87#if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
88 ax25_ds_setup_timer(ax25_dev);
89#endif
90
91 spin_lock_bh(lock: &ax25_dev_lock);
92 list_add(new: &ax25_dev->list, head: &ax25_dev_list);
93 rcu_assign_pointer(dev->ax25_ptr, ax25_dev);
94 spin_unlock_bh(lock: &ax25_dev_lock);
95
96 ax25_register_dev_sysctl(ax25_dev);
97}
98
99void ax25_dev_device_down(struct net_device *dev)
100{
101 ax25_dev *s, *ax25_dev;
102
103 if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
104 return;
105
106 ax25_unregister_dev_sysctl(ax25_dev);
107
108 spin_lock_bh(lock: &ax25_dev_lock);
109
110#ifdef CONFIG_AX25_DAMA_SLAVE
111 timer_shutdown_sync(timer: &ax25_dev->dama.slave_timer);
112#endif
113
114 /*
115 * Remove any packet forwarding that points to this device.
116 */
117 list_for_each_entry(s, &ax25_dev_list, list)
118 if (s->forward == dev)
119 s->forward = NULL;
120
121 list_for_each_entry(s, &ax25_dev_list, list) {
122 if (s == ax25_dev) {
123 list_del(entry: &s->list);
124 break;
125 }
126 }
127
128 RCU_INIT_POINTER(dev->ax25_ptr, NULL);
129 spin_unlock_bh(lock: &ax25_dev_lock);
130 netdev_put(dev, tracker: &ax25_dev->dev_tracker);
131 ax25_dev_put(ax25_dev);
132}
133
134int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd)
135{
136 ax25_dev *ax25_dev, *fwd_dev;
137
138 if ((ax25_dev = ax25_addr_ax25dev(addr: &fwd->port_from)) == NULL)
139 return -EINVAL;
140
141 switch (cmd) {
142 case SIOCAX25ADDFWD:
143 fwd_dev = ax25_addr_ax25dev(addr: &fwd->port_to);
144 if (!fwd_dev) {
145 ax25_dev_put(ax25_dev);
146 return -EINVAL;
147 }
148 if (ax25_dev->forward) {
149 ax25_dev_put(ax25_dev: fwd_dev);
150 ax25_dev_put(ax25_dev);
151 return -EINVAL;
152 }
153 ax25_dev->forward = fwd_dev->dev;
154 ax25_dev_put(ax25_dev: fwd_dev);
155 ax25_dev_put(ax25_dev);
156 break;
157
158 case SIOCAX25DELFWD:
159 if (!ax25_dev->forward) {
160 ax25_dev_put(ax25_dev);
161 return -EINVAL;
162 }
163 ax25_dev->forward = NULL;
164 ax25_dev_put(ax25_dev);
165 break;
166
167 default:
168 ax25_dev_put(ax25_dev);
169 return -EINVAL;
170 }
171
172 return 0;
173}
174
175struct net_device *ax25_fwd_dev(struct net_device *dev)
176{
177 ax25_dev *ax25_dev;
178
179 if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
180 return dev;
181
182 if (ax25_dev->forward == NULL)
183 return dev;
184
185 return ax25_dev->forward;
186}
187
188/*
189 * Free all memory associated with device structures.
190 */
191void __exit ax25_dev_free(void)
192{
193 ax25_dev *s, *n;
194
195 spin_lock_bh(lock: &ax25_dev_lock);
196 list_for_each_entry_safe(s, n, &ax25_dev_list, list) {
197 netdev_put(dev: s->dev, tracker: &s->dev_tracker);
198 list_del(entry: &s->list);
199 ax25_dev_put(ax25_dev: s);
200 }
201 spin_unlock_bh(lock: &ax25_dev_lock);
202}
203

source code of linux/net/ax25/ax25_dev.c