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/jiffies.h> |
12 | #include <linux/timer.h> |
13 | #include <linux/string.h> |
14 | #include <linux/sockios.h> |
15 | #include <linux/net.h> |
16 | #include <linux/slab.h> |
17 | #include <net/ax25.h> |
18 | #include <linux/inet.h> |
19 | #include <linux/netdevice.h> |
20 | #include <linux/skbuff.h> |
21 | #include <net/sock.h> |
22 | #include <linux/fcntl.h> |
23 | #include <linux/mm.h> |
24 | #include <linux/interrupt.h> |
25 | #include <net/rose.h> |
26 | |
27 | static void rose_ftimer_expiry(struct timer_list *); |
28 | static void rose_t0timer_expiry(struct timer_list *); |
29 | |
30 | static void rose_transmit_restart_confirmation(struct rose_neigh *neigh); |
31 | static void rose_transmit_restart_request(struct rose_neigh *neigh); |
32 | |
33 | void rose_start_ftimer(struct rose_neigh *neigh) |
34 | { |
35 | del_timer(timer: &neigh->ftimer); |
36 | |
37 | neigh->ftimer.function = rose_ftimer_expiry; |
38 | neigh->ftimer.expires = |
39 | jiffies + msecs_to_jiffies(m: sysctl_rose_link_fail_timeout); |
40 | |
41 | add_timer(timer: &neigh->ftimer); |
42 | } |
43 | |
44 | static void rose_start_t0timer(struct rose_neigh *neigh) |
45 | { |
46 | del_timer(timer: &neigh->t0timer); |
47 | |
48 | neigh->t0timer.function = rose_t0timer_expiry; |
49 | neigh->t0timer.expires = |
50 | jiffies + msecs_to_jiffies(m: sysctl_rose_restart_request_timeout); |
51 | |
52 | add_timer(timer: &neigh->t0timer); |
53 | } |
54 | |
55 | void rose_stop_ftimer(struct rose_neigh *neigh) |
56 | { |
57 | del_timer(timer: &neigh->ftimer); |
58 | } |
59 | |
60 | void rose_stop_t0timer(struct rose_neigh *neigh) |
61 | { |
62 | del_timer(timer: &neigh->t0timer); |
63 | } |
64 | |
65 | int rose_ftimer_running(struct rose_neigh *neigh) |
66 | { |
67 | return timer_pending(timer: &neigh->ftimer); |
68 | } |
69 | |
70 | static int rose_t0timer_running(struct rose_neigh *neigh) |
71 | { |
72 | return timer_pending(timer: &neigh->t0timer); |
73 | } |
74 | |
75 | static void rose_ftimer_expiry(struct timer_list *t) |
76 | { |
77 | } |
78 | |
79 | static void rose_t0timer_expiry(struct timer_list *t) |
80 | { |
81 | struct rose_neigh *neigh = from_timer(neigh, t, t0timer); |
82 | |
83 | rose_transmit_restart_request(neigh); |
84 | |
85 | neigh->dce_mode = 0; |
86 | |
87 | rose_start_t0timer(neigh); |
88 | } |
89 | |
90 | /* |
91 | * Interface to ax25_send_frame. Changes my level 2 callsign depending |
92 | * on whether we have a global ROSE callsign or use the default port |
93 | * callsign. |
94 | */ |
95 | static int rose_send_frame(struct sk_buff *skb, struct rose_neigh *neigh) |
96 | { |
97 | const ax25_address *rose_call; |
98 | ax25_cb *ax25s; |
99 | |
100 | if (ax25cmp(&rose_callsign, &null_ax25_address) == 0) |
101 | rose_call = (const ax25_address *)neigh->dev->dev_addr; |
102 | else |
103 | rose_call = &rose_callsign; |
104 | |
105 | ax25s = neigh->ax25; |
106 | neigh->ax25 = ax25_send_frame(skb, 260, rose_call, &neigh->callsign, neigh->digipeat, neigh->dev); |
107 | if (ax25s) |
108 | ax25_cb_put(ax25: ax25s); |
109 | |
110 | return neigh->ax25 != NULL; |
111 | } |
112 | |
113 | /* |
114 | * Interface to ax25_link_up. Changes my level 2 callsign depending |
115 | * on whether we have a global ROSE callsign or use the default port |
116 | * callsign. |
117 | */ |
118 | static int rose_link_up(struct rose_neigh *neigh) |
119 | { |
120 | const ax25_address *rose_call; |
121 | ax25_cb *ax25s; |
122 | |
123 | if (ax25cmp(&rose_callsign, &null_ax25_address) == 0) |
124 | rose_call = (const ax25_address *)neigh->dev->dev_addr; |
125 | else |
126 | rose_call = &rose_callsign; |
127 | |
128 | ax25s = neigh->ax25; |
129 | neigh->ax25 = ax25_find_cb(rose_call, &neigh->callsign, neigh->digipeat, neigh->dev); |
130 | if (ax25s) |
131 | ax25_cb_put(ax25: ax25s); |
132 | |
133 | return neigh->ax25 != NULL; |
134 | } |
135 | |
136 | /* |
137 | * This handles all restart and diagnostic frames. |
138 | */ |
139 | void rose_link_rx_restart(struct sk_buff *skb, struct rose_neigh *neigh, unsigned short frametype) |
140 | { |
141 | struct sk_buff *skbn; |
142 | |
143 | switch (frametype) { |
144 | case ROSE_RESTART_REQUEST: |
145 | rose_stop_t0timer(neigh); |
146 | neigh->restarted = 1; |
147 | neigh->dce_mode = (skb->data[3] == ROSE_DTE_ORIGINATED); |
148 | rose_transmit_restart_confirmation(neigh); |
149 | break; |
150 | |
151 | case ROSE_RESTART_CONFIRMATION: |
152 | rose_stop_t0timer(neigh); |
153 | neigh->restarted = 1; |
154 | break; |
155 | |
156 | case ROSE_DIAGNOSTIC: |
157 | pr_warn("ROSE: received diagnostic #%d - %3ph\n" , skb->data[3], |
158 | skb->data + 4); |
159 | break; |
160 | |
161 | default: |
162 | printk(KERN_WARNING "ROSE: received unknown %02X with LCI 000\n" , frametype); |
163 | break; |
164 | } |
165 | |
166 | if (neigh->restarted) { |
167 | while ((skbn = skb_dequeue(list: &neigh->queue)) != NULL) |
168 | if (!rose_send_frame(skb: skbn, neigh)) |
169 | kfree_skb(skb: skbn); |
170 | } |
171 | } |
172 | |
173 | /* |
174 | * This routine is called when a Restart Request is needed |
175 | */ |
176 | static void rose_transmit_restart_request(struct rose_neigh *neigh) |
177 | { |
178 | struct sk_buff *skb; |
179 | unsigned char *dptr; |
180 | int len; |
181 | |
182 | len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3; |
183 | |
184 | if ((skb = alloc_skb(size: len, GFP_ATOMIC)) == NULL) |
185 | return; |
186 | |
187 | skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN); |
188 | |
189 | dptr = skb_put(skb, ROSE_MIN_LEN + 3); |
190 | |
191 | *dptr++ = AX25_P_ROSE; |
192 | *dptr++ = ROSE_GFI; |
193 | *dptr++ = 0x00; |
194 | *dptr++ = ROSE_RESTART_REQUEST; |
195 | *dptr++ = ROSE_DTE_ORIGINATED; |
196 | *dptr++ = 0; |
197 | |
198 | if (!rose_send_frame(skb, neigh)) |
199 | kfree_skb(skb); |
200 | } |
201 | |
202 | /* |
203 | * This routine is called when a Restart Confirmation is needed |
204 | */ |
205 | static void rose_transmit_restart_confirmation(struct rose_neigh *neigh) |
206 | { |
207 | struct sk_buff *skb; |
208 | unsigned char *dptr; |
209 | int len; |
210 | |
211 | len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 1; |
212 | |
213 | if ((skb = alloc_skb(size: len, GFP_ATOMIC)) == NULL) |
214 | return; |
215 | |
216 | skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN); |
217 | |
218 | dptr = skb_put(skb, ROSE_MIN_LEN + 1); |
219 | |
220 | *dptr++ = AX25_P_ROSE; |
221 | *dptr++ = ROSE_GFI; |
222 | *dptr++ = 0x00; |
223 | *dptr++ = ROSE_RESTART_CONFIRMATION; |
224 | |
225 | if (!rose_send_frame(skb, neigh)) |
226 | kfree_skb(skb); |
227 | } |
228 | |
229 | /* |
230 | * This routine is called when a Clear Request is needed outside of the context |
231 | * of a connected socket. |
232 | */ |
233 | void rose_transmit_clear_request(struct rose_neigh *neigh, unsigned int lci, unsigned char cause, unsigned char diagnostic) |
234 | { |
235 | struct sk_buff *skb; |
236 | unsigned char *dptr; |
237 | int len; |
238 | |
239 | if (!neigh->dev) |
240 | return; |
241 | |
242 | len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3; |
243 | |
244 | if ((skb = alloc_skb(size: len, GFP_ATOMIC)) == NULL) |
245 | return; |
246 | |
247 | skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN); |
248 | |
249 | dptr = skb_put(skb, ROSE_MIN_LEN + 3); |
250 | |
251 | *dptr++ = AX25_P_ROSE; |
252 | *dptr++ = ((lci >> 8) & 0x0F) | ROSE_GFI; |
253 | *dptr++ = ((lci >> 0) & 0xFF); |
254 | *dptr++ = ROSE_CLEAR_REQUEST; |
255 | *dptr++ = cause; |
256 | *dptr++ = diagnostic; |
257 | |
258 | if (!rose_send_frame(skb, neigh)) |
259 | kfree_skb(skb); |
260 | } |
261 | |
262 | void rose_transmit_link(struct sk_buff *skb, struct rose_neigh *neigh) |
263 | { |
264 | unsigned char *dptr; |
265 | |
266 | if (neigh->loopback) { |
267 | rose_loopback_queue(skb, neigh); |
268 | return; |
269 | } |
270 | |
271 | if (!rose_link_up(neigh)) |
272 | neigh->restarted = 0; |
273 | |
274 | dptr = skb_push(skb, len: 1); |
275 | *dptr++ = AX25_P_ROSE; |
276 | |
277 | if (neigh->restarted) { |
278 | if (!rose_send_frame(skb, neigh)) |
279 | kfree_skb(skb); |
280 | } else { |
281 | skb_queue_tail(list: &neigh->queue, newsk: skb); |
282 | |
283 | if (!rose_t0timer_running(neigh)) { |
284 | rose_transmit_restart_request(neigh); |
285 | neigh->dce_mode = 0; |
286 | rose_start_t0timer(neigh); |
287 | } |
288 | } |
289 | } |
290 | |