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/in.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/spinlock.h>
13 #include <linux/timer.h>
14 #include <linux/string.h>
15 #include <linux/sockios.h>
16 #include <linux/net.h>
17 #include <linux/slab.h>
18 #include <net/ax25.h>
19 #include <linux/inet.h>
20 #include <linux/netdevice.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
28 static struct ax25_protocol *protocol_list;
29 static DEFINE_RWLOCK(protocol_list_lock);
30
31 static HLIST_HEAD(ax25_linkfail_list);
32 static DEFINE_SPINLOCK(linkfail_lock);
33
34 static struct listen_struct {
35 struct listen_struct *next;
36 ax25_address callsign;
37 struct net_device *dev;
38 } *listen_list = NULL;
39 static DEFINE_SPINLOCK(listen_lock);
40
41 /*
42 * Do not register the internal protocols AX25_P_TEXT, AX25_P_SEGMENT,
43 * AX25_P_IP or AX25_P_ARP ...
44 */
45 void ax25_register_pid(struct ax25_protocol *ap)
46 {
47 write_lock_bh(&protocol_list_lock);
48 ap->next = protocol_list;
49 protocol_list = ap;
50 write_unlock_bh(&protocol_list_lock);
51 }
52
53 EXPORT_SYMBOL_GPL(ax25_register_pid);
54
55 void ax25_protocol_release(unsigned int pid)
56 {
57 struct ax25_protocol *protocol;
58
59 write_lock_bh(&protocol_list_lock);
60 protocol = protocol_list;
61 if (protocol == NULL)
62 goto out;
63
64 if (protocol->pid == pid) {
65 protocol_list = protocol->next;
66 goto out;
67 }
68
69 while (protocol != NULL && protocol->next != NULL) {
70 if (protocol->next->pid == pid) {
71 protocol->next = protocol->next->next;
72 goto out;
73 }
74
75 protocol = protocol->next;
76 }
77 out:
78 write_unlock_bh(&protocol_list_lock);
79 }
80
81 EXPORT_SYMBOL(ax25_protocol_release);
82
83 void ax25_linkfail_register(struct ax25_linkfail *lf)
84 {
85 spin_lock_bh(&linkfail_lock);
86 hlist_add_head(&lf->lf_node, &ax25_linkfail_list);
87 spin_unlock_bh(&linkfail_lock);
88 }
89
90 EXPORT_SYMBOL(ax25_linkfail_register);
91
92 void ax25_linkfail_release(struct ax25_linkfail *lf)
93 {
94 spin_lock_bh(&linkfail_lock);
95 hlist_del_init(&lf->lf_node);
96 spin_unlock_bh(&linkfail_lock);
97 }
98
99 EXPORT_SYMBOL(ax25_linkfail_release);
100
101 int ax25_listen_register(const ax25_address *callsign, struct net_device *dev)
102 {
103 struct listen_struct *listen;
104
105 if (ax25_listen_mine(callsign, dev))
106 return 0;
107
108 if ((listen = kmalloc(sizeof(*listen), GFP_ATOMIC)) == NULL)
109 return -ENOMEM;
110
111 listen->callsign = *callsign;
112 listen->dev = dev;
113
114 spin_lock_bh(&listen_lock);
115 listen->next = listen_list;
116 listen_list = listen;
117 spin_unlock_bh(&listen_lock);
118
119 return 0;
120 }
121
122 EXPORT_SYMBOL(ax25_listen_register);
123
124 void ax25_listen_release(const ax25_address *callsign, struct net_device *dev)
125 {
126 struct listen_struct *s, *listen;
127
128 spin_lock_bh(&listen_lock);
129 listen = listen_list;
130 if (listen == NULL) {
131 spin_unlock_bh(&listen_lock);
132 return;
133 }
134
135 if (ax25cmp(&listen->callsign, callsign) == 0 && listen->dev == dev) {
136 listen_list = listen->next;
137 spin_unlock_bh(&listen_lock);
138 kfree(listen);
139 return;
140 }
141
142 while (listen != NULL && listen->next != NULL) {
143 if (ax25cmp(&listen->next->callsign, callsign) == 0 && listen->next->dev == dev) {
144 s = listen->next;
145 listen->next = listen->next->next;
146 spin_unlock_bh(&listen_lock);
147 kfree(s);
148 return;
149 }
150
151 listen = listen->next;
152 }
153 spin_unlock_bh(&listen_lock);
154 }
155
156 EXPORT_SYMBOL(ax25_listen_release);
157
158 int (*ax25_protocol_function(unsigned int pid))(struct sk_buff *, ax25_cb *)
159 {
160 int (*res)(struct sk_buff *, ax25_cb *) = NULL;
161 struct ax25_protocol *protocol;
162
163 read_lock(&protocol_list_lock);
164 for (protocol = protocol_list; protocol != NULL; protocol = protocol->next)
165 if (protocol->pid == pid) {
166 res = protocol->func;
167 break;
168 }
169 read_unlock(&protocol_list_lock);
170
171 return res;
172 }
173
174 int ax25_listen_mine(const ax25_address *callsign, struct net_device *dev)
175 {
176 struct listen_struct *listen;
177
178 spin_lock_bh(&listen_lock);
179 for (listen = listen_list; listen != NULL; listen = listen->next)
180 if (ax25cmp(&listen->callsign, callsign) == 0 &&
181 (listen->dev == dev || listen->dev == NULL)) {
182 spin_unlock_bh(&listen_lock);
183 return 1;
184 }
185 spin_unlock_bh(&listen_lock);
186
187 return 0;
188 }
189
190 void ax25_link_failed(ax25_cb *ax25, int reason)
191 {
192 struct ax25_linkfail *lf;
193
194 spin_lock_bh(&linkfail_lock);
195 hlist_for_each_entry(lf, &ax25_linkfail_list, lf_node)
196 lf->func(ax25, reason);
197 spin_unlock_bh(&linkfail_lock);
198 }
199
200 int ax25_protocol_is_registered(unsigned int pid)
201 {
202 struct ax25_protocol *protocol;
203 int res = 0;
204
205 read_lock_bh(&protocol_list_lock);
206 for (protocol = protocol_list; protocol != NULL; protocol = protocol->next)
207 if (protocol->pid == pid) {
208 res = 1;
209 break;
210 }
211 read_unlock_bh(&protocol_list_lock);
212
213 return res;
214 }
215
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