xref: /linux/include/net/ax25.h (revision 23c48a124b469cee2eb0c75e6d22d366d1caa118)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  *	Declarations of AX.25 type objects.
4  *
5  *	Alan Cox (GW4PTS) 	10/11/93
6  */
7 #ifndef _AX25_H
8 #define _AX25_H
9 
10 #include <linux/ax25.h>
11 #include <linux/spinlock.h>
12 #include <linux/timer.h>
13 #include <linux/list.h>
14 #include <linux/slab.h>
15 #include <linux/refcount.h>
16 #include <net/neighbour.h>
17 #include <net/sock.h>
18 #include <linux/seq_file.h>
19 
20 #define	AX25_T1CLAMPLO  		1
21 #define	AX25_T1CLAMPHI 			(30 * HZ)
22 
23 #define	AX25_BPQ_HEADER_LEN		16
24 #define	AX25_KISS_HEADER_LEN		1
25 
26 #define	AX25_HEADER_LEN			17
27 #define	AX25_ADDR_LEN			7
28 #define	AX25_DIGI_HEADER_LEN		(AX25_MAX_DIGIS * AX25_ADDR_LEN)
29 #define	AX25_MAX_HEADER_LEN		(AX25_HEADER_LEN + AX25_DIGI_HEADER_LEN)
30 
31 /* AX.25 Protocol IDs */
32 #define AX25_P_ROSE			0x01
33 #define AX25_P_VJCOMP			0x06	/* Compressed TCP/IP packet   */
34 						/* Van Jacobsen (RFC 1144)    */
35 #define AX25_P_VJUNCOMP			0x07	/* Uncompressed TCP/IP packet */
36 						/* Van Jacobsen (RFC 1144)    */
37 #define	AX25_P_SEGMENT			0x08	/* Segmentation fragment      */
38 #define AX25_P_TEXNET			0xc3	/* TEXTNET datagram protocol  */
39 #define AX25_P_LQ			0xc4	/* Link Quality Protocol      */
40 #define AX25_P_ATALK			0xca	/* Appletalk                  */
41 #define AX25_P_ATALK_ARP		0xcb	/* Appletalk ARP              */
42 #define AX25_P_IP			0xcc	/* ARPA Internet Protocol     */
43 #define AX25_P_ARP			0xcd	/* ARPA Address Resolution    */
44 #define AX25_P_FLEXNET			0xce	/* FlexNet                    */
45 #define AX25_P_NETROM 			0xcf	/* NET/ROM                    */
46 #define AX25_P_TEXT 			0xF0	/* No layer 3 protocol impl.  */
47 
48 /* AX.25 Segment control values */
49 #define	AX25_SEG_REM			0x7F
50 #define	AX25_SEG_FIRST			0x80
51 
52 #define AX25_CBIT			0x80	/* Command/Response bit */
53 #define AX25_EBIT			0x01	/* HDLC Address Extension bit */
54 #define AX25_HBIT			0x80	/* Has been repeated bit */
55 
56 #define AX25_SSSID_SPARE		0x60	/* Unused bits in SSID for standard AX.25 */
57 #define AX25_ESSID_SPARE		0x20	/* Unused bits in SSID for extended AX.25 */
58 #define AX25_DAMA_FLAG			0x20	/* Well, it is *NOT* unused! (dl1bke 951121 */
59 
60 #define	AX25_COND_ACK_PENDING		0x01
61 #define	AX25_COND_REJECT		0x02
62 #define	AX25_COND_PEER_RX_BUSY		0x04
63 #define	AX25_COND_OWN_RX_BUSY		0x08
64 #define	AX25_COND_DAMA_MODE		0x10
65 
66 #ifndef _LINUX_NETDEVICE_H
67 #include <linux/netdevice.h>
68 #endif
69 
70 /* Upper sub-layer (LAPB) definitions */
71 
72 /* Control field templates */
73 #define	AX25_I			0x00	/* Information frames */
74 #define	AX25_S			0x01	/* Supervisory frames */
75 #define	AX25_RR			0x01	/* Receiver ready */
76 #define	AX25_RNR		0x05	/* Receiver not ready */
77 #define	AX25_REJ		0x09	/* Reject */
78 #define	AX25_U			0x03	/* Unnumbered frames */
79 #define	AX25_SABM		0x2f	/* Set Asynchronous Balanced Mode */
80 #define	AX25_SABME		0x6f	/* Set Asynchronous Balanced Mode Extended */
81 #define	AX25_DISC		0x43	/* Disconnect */
82 #define	AX25_DM			0x0f	/* Disconnected mode */
83 #define	AX25_UA			0x63	/* Unnumbered acknowledge */
84 #define	AX25_FRMR		0x87	/* Frame reject */
85 #define	AX25_UI			0x03	/* Unnumbered information */
86 #define	AX25_XID		0xaf	/* Exchange information */
87 #define	AX25_TEST		0xe3	/* Test */
88 
89 #define	AX25_PF			0x10	/* Poll/final bit for standard AX.25 */
90 #define	AX25_EPF		0x01	/* Poll/final bit for extended AX.25 */
91 
92 #define AX25_ILLEGAL		0x100	/* Impossible to be a real frame type */
93 
94 #define	AX25_POLLOFF		0
95 #define	AX25_POLLON		1
96 
97 /* AX25 L2 C-bit */
98 #define AX25_COMMAND		1
99 #define AX25_RESPONSE		2
100 
101 /* Define Link State constants. */
102 
103 enum {
104 	AX25_STATE_0,			/* Listening */
105 	AX25_STATE_1,			/* SABM sent */
106 	AX25_STATE_2,			/* DISC sent */
107 	AX25_STATE_3,			/* Established */
108 	AX25_STATE_4			/* Recovery */
109 };
110 
111 #define AX25_MODULUS 		8	/*  Standard AX.25 modulus */
112 #define	AX25_EMODULUS		128	/*  Extended AX.25 modulus */
113 
114 enum {
115 	AX25_PROTO_STD_SIMPLEX,
116 	AX25_PROTO_STD_DUPLEX,
117 #ifdef CONFIG_AX25_DAMA_SLAVE
118 	AX25_PROTO_DAMA_SLAVE,
119 #ifdef CONFIG_AX25_DAMA_MASTER
120 	AX25_PROTO_DAMA_MASTER,
121 #define AX25_PROTO_MAX AX25_PROTO_DAMA_MASTER
122 #endif
123 #endif
124 	__AX25_PROTO_MAX,
125 	AX25_PROTO_MAX = __AX25_PROTO_MAX -1
126 };
127 
128 enum {
129 	AX25_VALUES_IPDEFMODE,	/* 0=DG 1=VC */
130 	AX25_VALUES_AXDEFMODE,	/* 0=Normal 1=Extended Seq Nos */
131 	AX25_VALUES_BACKOFF,	/* 0=None 1=Linear 2=Exponential */
132 	AX25_VALUES_CONMODE,	/* Allow connected modes - 0=No 1=no "PID text" 2=all PIDs */
133 	AX25_VALUES_WINDOW,	/* Default window size for standard AX.25 */
134 	AX25_VALUES_EWINDOW,	/* Default window size for extended AX.25 */
135 	AX25_VALUES_T1,		/* Default T1 timeout value */
136 	AX25_VALUES_T2,		/* Default T2 timeout value */
137 	AX25_VALUES_T3,		/* Default T3 timeout value */
138 	AX25_VALUES_IDLE,	/* Connected mode idle timer */
139 	AX25_VALUES_N2,		/* Default N2 value */
140 	AX25_VALUES_PACLEN,	/* AX.25 MTU */
141 	AX25_VALUES_PROTOCOL,	/* Std AX.25, DAMA Slave, DAMA Master */
142 	AX25_VALUES_DS_TIMEOUT,	/* DAMA Slave timeout */
143 	AX25_MAX_VALUES		/* THIS MUST REMAIN THE LAST ENTRY OF THIS LIST */
144 };
145 
146 #define	AX25_DEF_IPDEFMODE	0			/* Datagram */
147 #define	AX25_DEF_AXDEFMODE	0			/* Normal */
148 #define	AX25_DEF_BACKOFF	1			/* Linear backoff */
149 #define	AX25_DEF_CONMODE	2			/* Connected mode allowed */
150 #define	AX25_DEF_WINDOW		2			/* Window=2 */
151 #define	AX25_DEF_EWINDOW	32			/* Module-128 Window=32 */
152 #define	AX25_DEF_T1		10000			/* T1=10s */
153 #define	AX25_DEF_T2		3000			/* T2=3s  */
154 #define	AX25_DEF_T3		300000			/* T3=300s */
155 #define	AX25_DEF_N2		10			/* N2=10 */
156 #define AX25_DEF_IDLE		0			/* Idle=None */
157 #define AX25_DEF_PACLEN		256			/* Paclen=256 */
158 #define	AX25_DEF_PROTOCOL	AX25_PROTO_STD_SIMPLEX	/* Standard AX.25 */
159 #define AX25_DEF_DS_TIMEOUT	180000			/* DAMA timeout 3 minutes */
160 
161 typedef struct ax25_uid_assoc {
162 	struct hlist_node	uid_node;
163 	refcount_t		refcount;
164 	kuid_t			uid;
165 	ax25_address		call;
166 } ax25_uid_assoc;
167 
168 #define ax25_uid_for_each(__ax25, list) \
169 	hlist_for_each_entry(__ax25, list, uid_node)
170 
171 #define ax25_uid_hold(ax25) \
172 	refcount_inc(&((ax25)->refcount))
173 
174 static inline void ax25_uid_put(ax25_uid_assoc *assoc)
175 {
176 	if (refcount_dec_and_test(&assoc->refcount)) {
177 		kfree(assoc);
178 	}
179 }
180 
181 typedef struct {
182 	ax25_address		calls[AX25_MAX_DIGIS];
183 	unsigned char		repeated[AX25_MAX_DIGIS];
184 	unsigned char		ndigi;
185 	signed char		lastrepeat;
186 } ax25_digi;
187 
188 typedef struct ax25_route {
189 	struct ax25_route	*next;
190 	ax25_address		callsign;
191 	struct net_device	*dev;
192 	ax25_digi		*digipeat;
193 	char			ip_mode;
194 } ax25_route;
195 
196 void __ax25_put_route(ax25_route *ax25_rt);
197 
198 extern rwlock_t ax25_route_lock;
199 
200 static inline void ax25_route_lock_use(void)
201 {
202 	read_lock(&ax25_route_lock);
203 }
204 
205 static inline void ax25_route_lock_unuse(void)
206 {
207 	read_unlock(&ax25_route_lock);
208 }
209 
210 typedef struct {
211 	char			slave;			/* slave_mode?   */
212 	struct timer_list	slave_timer;		/* timeout timer */
213 	unsigned short		slave_timeout;		/* when? */
214 } ax25_dama_info;
215 
216 struct ctl_table;
217 
218 typedef struct ax25_dev {
219 	struct ax25_dev		*next;
220 
221 	struct net_device	*dev;
222 	netdevice_tracker	dev_tracker;
223 
224 	struct net_device	*forward;
225 	struct ctl_table_header *sysheader;
226 	int			values[AX25_MAX_VALUES];
227 #if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
228 	ax25_dama_info		dama;
229 #endif
230 	refcount_t		refcount;
231 	bool device_up;
232 } ax25_dev;
233 
234 typedef struct ax25_cb {
235 	struct hlist_node	ax25_node;
236 	ax25_address		source_addr, dest_addr;
237 	ax25_digi		*digipeat;
238 	ax25_dev		*ax25_dev;
239 	netdevice_tracker	dev_tracker;
240 	unsigned char		iamdigi;
241 	unsigned char		state, modulus, pidincl;
242 	unsigned short		vs, vr, va;
243 	unsigned char		condition, backoff;
244 	unsigned char		n2, n2count;
245 	struct timer_list	t1timer, t2timer, t3timer, idletimer;
246 	unsigned long		t1, t2, t3, idle, rtt;
247 	unsigned short		paclen, fragno, fraglen;
248 	struct sk_buff_head	write_queue;
249 	struct sk_buff_head	reseq_queue;
250 	struct sk_buff_head	ack_queue;
251 	struct sk_buff_head	frag_queue;
252 	unsigned char		window;
253 	struct timer_list	timer, dtimer;
254 	struct sock		*sk;		/* Backlink to socket */
255 	refcount_t		refcount;
256 } ax25_cb;
257 
258 struct ax25_sock {
259 	struct sock		sk;
260 	struct ax25_cb		*cb;
261 };
262 
263 static inline struct ax25_sock *ax25_sk(const struct sock *sk)
264 {
265 	return (struct ax25_sock *) sk;
266 }
267 
268 static inline struct ax25_cb *sk_to_ax25(const struct sock *sk)
269 {
270 	return ax25_sk(sk)->cb;
271 }
272 
273 #define ax25_for_each(__ax25, list) \
274 	hlist_for_each_entry(__ax25, list, ax25_node)
275 
276 #define ax25_cb_hold(__ax25) \
277 	refcount_inc(&((__ax25)->refcount))
278 
279 static __inline__ void ax25_cb_put(ax25_cb *ax25)
280 {
281 	if (refcount_dec_and_test(&ax25->refcount)) {
282 		kfree(ax25->digipeat);
283 		kfree(ax25);
284 	}
285 }
286 
287 static inline void ax25_dev_hold(ax25_dev *ax25_dev)
288 {
289 	refcount_inc(&ax25_dev->refcount);
290 }
291 
292 static inline void ax25_dev_put(ax25_dev *ax25_dev)
293 {
294 	if (refcount_dec_and_test(&ax25_dev->refcount)) {
295 		kfree(ax25_dev);
296 	}
297 }
298 static inline __be16 ax25_type_trans(struct sk_buff *skb, struct net_device *dev)
299 {
300 	skb->dev      = dev;
301 	skb_reset_mac_header(skb);
302 	skb->pkt_type = PACKET_HOST;
303 	return htons(ETH_P_AX25);
304 }
305 
306 /* af_ax25.c */
307 extern struct hlist_head ax25_list;
308 extern spinlock_t ax25_list_lock;
309 void ax25_cb_add(ax25_cb *);
310 struct sock *ax25_find_listener(ax25_address *, int, struct net_device *, int);
311 struct sock *ax25_get_socket(ax25_address *, ax25_address *, int);
312 ax25_cb *ax25_find_cb(const ax25_address *, ax25_address *, ax25_digi *,
313 		      struct net_device *);
314 void ax25_send_to_raw(ax25_address *, struct sk_buff *, int);
315 void ax25_destroy_socket(ax25_cb *);
316 ax25_cb * __must_check ax25_create_cb(void);
317 void ax25_fillin_cb(ax25_cb *, ax25_dev *);
318 struct sock *ax25_make_new(struct sock *, struct ax25_dev *);
319 
320 /* ax25_addr.c */
321 extern const ax25_address ax25_bcast;
322 extern const ax25_address ax25_defaddr;
323 extern const ax25_address null_ax25_address;
324 char *ax2asc(char *buf, const ax25_address *);
325 void asc2ax(ax25_address *addr, const char *callsign);
326 int ax25cmp(const ax25_address *, const ax25_address *);
327 int ax25digicmp(const ax25_digi *, const ax25_digi *);
328 const unsigned char *ax25_addr_parse(const unsigned char *, int,
329 	ax25_address *, ax25_address *, ax25_digi *, int *, int *);
330 int ax25_addr_build(unsigned char *, const ax25_address *,
331 		    const ax25_address *, const ax25_digi *, int, int);
332 int ax25_addr_size(const ax25_digi *);
333 void ax25_digi_invert(const ax25_digi *, ax25_digi *);
334 
335 /* ax25_dev.c */
336 extern ax25_dev *ax25_dev_list;
337 extern spinlock_t ax25_dev_lock;
338 
339 #if IS_ENABLED(CONFIG_AX25)
340 static inline ax25_dev *ax25_dev_ax25dev(struct net_device *dev)
341 {
342 	return dev->ax25_ptr;
343 }
344 #endif
345 
346 ax25_dev *ax25_addr_ax25dev(ax25_address *);
347 void ax25_dev_device_up(struct net_device *);
348 void ax25_dev_device_down(struct net_device *);
349 int ax25_fwd_ioctl(unsigned int, struct ax25_fwd_struct *);
350 struct net_device *ax25_fwd_dev(struct net_device *);
351 void ax25_dev_free(void);
352 
353 /* ax25_ds_in.c */
354 int ax25_ds_frame_in(ax25_cb *, struct sk_buff *, int);
355 
356 /* ax25_ds_subr.c */
357 void ax25_ds_nr_error_recovery(ax25_cb *);
358 void ax25_ds_enquiry_response(ax25_cb *);
359 void ax25_ds_establish_data_link(ax25_cb *);
360 void ax25_dev_dama_off(ax25_dev *);
361 void ax25_dama_on(ax25_cb *);
362 void ax25_dama_off(ax25_cb *);
363 
364 /* ax25_ds_timer.c */
365 void ax25_ds_setup_timer(ax25_dev *);
366 void ax25_ds_set_timer(ax25_dev *);
367 void ax25_ds_del_timer(ax25_dev *);
368 void ax25_ds_timer(ax25_cb *);
369 void ax25_ds_t1_timeout(ax25_cb *);
370 void ax25_ds_heartbeat_expiry(ax25_cb *);
371 void ax25_ds_t3timer_expiry(ax25_cb *);
372 void ax25_ds_idletimer_expiry(ax25_cb *);
373 
374 /* ax25_iface.c */
375 
376 struct ax25_protocol {
377 	struct ax25_protocol *next;
378 	unsigned int pid;
379 	int (*func)(struct sk_buff *, ax25_cb *);
380 };
381 
382 void ax25_register_pid(struct ax25_protocol *ap);
383 void ax25_protocol_release(unsigned int);
384 
385 struct ax25_linkfail {
386 	struct hlist_node lf_node;
387 	void (*func)(ax25_cb *, int);
388 };
389 
390 void ax25_linkfail_register(struct ax25_linkfail *lf);
391 void ax25_linkfail_release(struct ax25_linkfail *lf);
392 int __must_check ax25_listen_register(const ax25_address *,
393 				      struct net_device *);
394 void ax25_listen_release(const ax25_address *, struct net_device *);
395 int(*ax25_protocol_function(unsigned int))(struct sk_buff *, ax25_cb *);
396 int ax25_listen_mine(const ax25_address *, struct net_device *);
397 void ax25_link_failed(ax25_cb *, int);
398 int ax25_protocol_is_registered(unsigned int);
399 
400 /* ax25_in.c */
401 int ax25_rx_iframe(ax25_cb *, struct sk_buff *);
402 int ax25_kiss_rcv(struct sk_buff *, struct net_device *, struct packet_type *,
403 		  struct net_device *);
404 
405 /* ax25_ip.c */
406 netdev_tx_t ax25_ip_xmit(struct sk_buff *skb);
407 extern const struct header_ops ax25_header_ops;
408 
409 /* ax25_out.c */
410 ax25_cb *ax25_send_frame(struct sk_buff *, int, const ax25_address *,
411 			 ax25_address *, ax25_digi *, struct net_device *);
412 void ax25_output(ax25_cb *, int, struct sk_buff *);
413 void ax25_kick(ax25_cb *);
414 void ax25_transmit_buffer(ax25_cb *, struct sk_buff *, int);
415 void ax25_queue_xmit(struct sk_buff *skb, struct net_device *dev);
416 int ax25_check_iframes_acked(ax25_cb *, unsigned short);
417 
418 /* ax25_route.c */
419 void ax25_rt_device_down(struct net_device *);
420 int ax25_rt_ioctl(unsigned int, void __user *);
421 extern const struct seq_operations ax25_rt_seqops;
422 ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev);
423 int ax25_rt_autobind(ax25_cb *, ax25_address *);
424 struct sk_buff *ax25_rt_build_path(struct sk_buff *, ax25_address *,
425 				   ax25_address *, ax25_digi *);
426 void ax25_rt_free(void);
427 
428 /* ax25_std_in.c */
429 int ax25_std_frame_in(ax25_cb *, struct sk_buff *, int);
430 
431 /* ax25_std_subr.c */
432 void ax25_std_nr_error_recovery(ax25_cb *);
433 void ax25_std_establish_data_link(ax25_cb *);
434 void ax25_std_transmit_enquiry(ax25_cb *);
435 void ax25_std_enquiry_response(ax25_cb *);
436 void ax25_std_timeout_response(ax25_cb *);
437 
438 /* ax25_std_timer.c */
439 void ax25_std_heartbeat_expiry(ax25_cb *);
440 void ax25_std_t1timer_expiry(ax25_cb *);
441 void ax25_std_t2timer_expiry(ax25_cb *);
442 void ax25_std_t3timer_expiry(ax25_cb *);
443 void ax25_std_idletimer_expiry(ax25_cb *);
444 
445 /* ax25_subr.c */
446 void ax25_clear_queues(ax25_cb *);
447 void ax25_frames_acked(ax25_cb *, unsigned short);
448 void ax25_requeue_frames(ax25_cb *);
449 int ax25_validate_nr(ax25_cb *, unsigned short);
450 int ax25_decode(ax25_cb *, struct sk_buff *, int *, int *, int *);
451 void ax25_send_control(ax25_cb *, int, int, int);
452 void ax25_return_dm(struct net_device *, ax25_address *, ax25_address *,
453 		    ax25_digi *);
454 void ax25_calculate_t1(ax25_cb *);
455 void ax25_calculate_rtt(ax25_cb *);
456 void ax25_disconnect(ax25_cb *, int);
457 
458 /* ax25_timer.c */
459 void ax25_setup_timers(ax25_cb *);
460 void ax25_start_heartbeat(ax25_cb *);
461 void ax25_start_t1timer(ax25_cb *);
462 void ax25_start_t2timer(ax25_cb *);
463 void ax25_start_t3timer(ax25_cb *);
464 void ax25_start_idletimer(ax25_cb *);
465 void ax25_stop_heartbeat(ax25_cb *);
466 void ax25_stop_t1timer(ax25_cb *);
467 void ax25_stop_t2timer(ax25_cb *);
468 void ax25_stop_t3timer(ax25_cb *);
469 void ax25_stop_idletimer(ax25_cb *);
470 int ax25_t1timer_running(ax25_cb *);
471 unsigned long ax25_display_timer(struct timer_list *);
472 
473 /* ax25_uid.c */
474 extern int  ax25_uid_policy;
475 ax25_uid_assoc *ax25_findbyuid(kuid_t);
476 int __must_check ax25_uid_ioctl(int, struct sockaddr_ax25 *);
477 extern const struct seq_operations ax25_uid_seqops;
478 void ax25_uid_free(void);
479 
480 /* sysctl_net_ax25.c */
481 #ifdef CONFIG_SYSCTL
482 int ax25_register_dev_sysctl(ax25_dev *ax25_dev);
483 void ax25_unregister_dev_sysctl(ax25_dev *ax25_dev);
484 #else
485 static inline int ax25_register_dev_sysctl(ax25_dev *ax25_dev) { return 0; }
486 static inline void ax25_unregister_dev_sysctl(ax25_dev *ax25_dev) {}
487 #endif /* CONFIG_SYSCTL */
488 
489 #endif
490