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(lock: &linkfail_lock); |
86 | hlist_add_head(n: &lf->lf_node, h: &ax25_linkfail_list); |
87 | spin_unlock_bh(lock: &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(lock: &linkfail_lock); |
95 | hlist_del_init(n: &lf->lf_node); |
96 | spin_unlock_bh(lock: &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(size: sizeof(*listen), GFP_ATOMIC)) == NULL) |
109 | return -ENOMEM; |
110 | |
111 | listen->callsign = *callsign; |
112 | listen->dev = dev; |
113 | |
114 | spin_lock_bh(lock: &listen_lock); |
115 | listen->next = listen_list; |
116 | listen_list = listen; |
117 | spin_unlock_bh(lock: &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(lock: &listen_lock); |
129 | listen = listen_list; |
130 | if (listen == NULL) { |
131 | spin_unlock_bh(lock: &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(lock: &listen_lock); |
138 | kfree(objp: 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(lock: &listen_lock); |
147 | kfree(objp: s); |
148 | return; |
149 | } |
150 | |
151 | listen = listen->next; |
152 | } |
153 | spin_unlock_bh(lock: &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(lock: &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(lock: &listen_lock); |
183 | return 1; |
184 | } |
185 | spin_unlock_bh(lock: &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(lock: &linkfail_lock); |
195 | hlist_for_each_entry(lf, &ax25_linkfail_list, lf_node) |
196 | lf->func(ax25, reason); |
197 | spin_unlock_bh(lock: &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 | |