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
29ax25_dev *ax25_dev_list;
30DEFINE_SPINLOCK(ax25_dev_lock);
31
32ax25_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 */
51void ax25_dev_device_up(struct net_device *dev)
52{
53	ax25_dev *ax25_dev;
54
55	ax25_dev = kzalloc(sizeof(*ax25_dev), GFP_KERNEL);
56	if (!ax25_dev) {
57		printk(KERN_ERR "AX.25: ax25_dev_device_up - out of memory\n");
58		return;
59	}
60
61	refcount_set(&ax25_dev->refcount, 1);
62	dev->ax25_ptr     = ax25_dev;
63	ax25_dev->dev     = dev;
64	netdev_hold(dev, &ax25_dev->dev_tracker, GFP_KERNEL);
65	ax25_dev->forward = NULL;
66	ax25_dev->device_up = true;
67
68	ax25_dev->values[AX25_VALUES_IPDEFMODE] = AX25_DEF_IPDEFMODE;
69	ax25_dev->values[AX25_VALUES_AXDEFMODE] = AX25_DEF_AXDEFMODE;
70	ax25_dev->values[AX25_VALUES_BACKOFF]   = AX25_DEF_BACKOFF;
71	ax25_dev->values[AX25_VALUES_CONMODE]   = AX25_DEF_CONMODE;
72	ax25_dev->values[AX25_VALUES_WINDOW]    = AX25_DEF_WINDOW;
73	ax25_dev->values[AX25_VALUES_EWINDOW]   = AX25_DEF_EWINDOW;
74	ax25_dev->values[AX25_VALUES_T1]        = AX25_DEF_T1;
75	ax25_dev->values[AX25_VALUES_T2]        = AX25_DEF_T2;
76	ax25_dev->values[AX25_VALUES_T3]        = AX25_DEF_T3;
77	ax25_dev->values[AX25_VALUES_IDLE]	= AX25_DEF_IDLE;
78	ax25_dev->values[AX25_VALUES_N2]        = AX25_DEF_N2;
79	ax25_dev->values[AX25_VALUES_PACLEN]	= AX25_DEF_PACLEN;
80	ax25_dev->values[AX25_VALUES_PROTOCOL]  = AX25_DEF_PROTOCOL;
81	ax25_dev->values[AX25_VALUES_DS_TIMEOUT]= AX25_DEF_DS_TIMEOUT;
82
83#if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
84	ax25_ds_setup_timer(ax25_dev);
85#endif
86
87	spin_lock_bh(&ax25_dev_lock);
88	ax25_dev->next = ax25_dev_list;
89	ax25_dev_list  = ax25_dev;
90	spin_unlock_bh(&ax25_dev_lock);
91	ax25_dev_hold(ax25_dev);
92
93	ax25_register_dev_sysctl(ax25_dev);
94}
95
96void 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	for (s = ax25_dev_list; s != NULL; s = s->next)
115		if (s->forward == dev)
116			s->forward = NULL;
117
118	if ((s = ax25_dev_list) == ax25_dev) {
119		ax25_dev_list = s->next;
120		goto unlock_put;
121	}
122
123	while (s != NULL && s->next != NULL) {
124		if (s->next == ax25_dev) {
125			s->next = ax25_dev->next;
126			goto unlock_put;
127		}
128
129		s = s->next;
130	}
131	spin_unlock_bh(&ax25_dev_lock);
132	dev->ax25_ptr = NULL;
133	ax25_dev_put(ax25_dev);
134	return;
135
136unlock_put:
137	spin_unlock_bh(&ax25_dev_lock);
138	ax25_dev_put(ax25_dev);
139	dev->ax25_ptr = NULL;
140	netdev_put(dev, &ax25_dev->dev_tracker);
141	ax25_dev_put(ax25_dev);
142}
143
144int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd)
145{
146	ax25_dev *ax25_dev, *fwd_dev;
147
148	if ((ax25_dev = ax25_addr_ax25dev(&fwd->port_from)) == NULL)
149		return -EINVAL;
150
151	switch (cmd) {
152	case SIOCAX25ADDFWD:
153		fwd_dev = ax25_addr_ax25dev(&fwd->port_to);
154		if (!fwd_dev) {
155			ax25_dev_put(ax25_dev);
156			return -EINVAL;
157		}
158		if (ax25_dev->forward) {
159			ax25_dev_put(fwd_dev);
160			ax25_dev_put(ax25_dev);
161			return -EINVAL;
162		}
163		ax25_dev->forward = fwd_dev->dev;
164		ax25_dev_put(fwd_dev);
165		ax25_dev_put(ax25_dev);
166		break;
167
168	case SIOCAX25DELFWD:
169		if (!ax25_dev->forward) {
170			ax25_dev_put(ax25_dev);
171			return -EINVAL;
172		}
173		ax25_dev->forward = NULL;
174		ax25_dev_put(ax25_dev);
175		break;
176
177	default:
178		ax25_dev_put(ax25_dev);
179		return -EINVAL;
180	}
181
182	return 0;
183}
184
185struct net_device *ax25_fwd_dev(struct net_device *dev)
186{
187	ax25_dev *ax25_dev;
188
189	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
190		return dev;
191
192	if (ax25_dev->forward == NULL)
193		return dev;
194
195	return ax25_dev->forward;
196}
197
198/*
199 *	Free all memory associated with device structures.
200 */
201void __exit ax25_dev_free(void)
202{
203	ax25_dev *s, *ax25_dev;
204
205	spin_lock_bh(&ax25_dev_lock);
206	ax25_dev = ax25_dev_list;
207	while (ax25_dev != NULL) {
208		s        = ax25_dev;
209		netdev_put(ax25_dev->dev, &ax25_dev->dev_tracker);
210		ax25_dev = ax25_dev->next;
211		kfree(s);
212	}
213	ax25_dev_list = NULL;
214	spin_unlock_bh(&ax25_dev_lock);
215}
216