xref: /linux/include/net/ax25.h (revision bf070bb0e6c62ba3075db0a666763ba52c677102)
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 
19 #define	AX25_T1CLAMPLO  		1
20 #define	AX25_T1CLAMPHI 			(30 * HZ)
21 
22 #define	AX25_BPQ_HEADER_LEN		16
23 #define	AX25_KISS_HEADER_LEN		1
24 
25 #define	AX25_HEADER_LEN			17
26 #define	AX25_ADDR_LEN			7
27 #define	AX25_DIGI_HEADER_LEN		(AX25_MAX_DIGIS * AX25_ADDR_LEN)
28 #define	AX25_MAX_HEADER_LEN		(AX25_HEADER_LEN + AX25_DIGI_HEADER_LEN)
29 
30 /* AX.25 Protocol IDs */
31 #define AX25_P_ROSE			0x01
32 #define AX25_P_VJCOMP			0x06	/* Compressed TCP/IP packet   */
33 						/* Van Jacobsen (RFC 1144)    */
34 #define AX25_P_VJUNCOMP			0x07	/* Uncompressed TCP/IP packet */
35 						/* Van Jacobsen (RFC 1144)    */
36 #define	AX25_P_SEGMENT			0x08	/* Segmentation fragment      */
37 #define AX25_P_TEXNET			0xc3	/* TEXTNET datagram protocol  */
38 #define AX25_P_LQ			0xc4	/* Link Quality Protocol      */
39 #define AX25_P_ATALK			0xca	/* Appletalk                  */
40 #define AX25_P_ATALK_ARP		0xcb	/* Appletalk ARP              */
41 #define AX25_P_IP			0xcc	/* ARPA Internet Protocol     */
42 #define AX25_P_ARP			0xcd	/* ARPA Address Resolution    */
43 #define AX25_P_FLEXNET			0xce	/* FlexNet                    */
44 #define AX25_P_NETROM 			0xcf	/* NET/ROM                    */
45 #define AX25_P_TEXT 			0xF0	/* No layer 3 protocol impl.  */
46 
47 /* AX.25 Segment control values */
48 #define	AX25_SEG_REM			0x7F
49 #define	AX25_SEG_FIRST			0x80
50 
51 #define AX25_CBIT			0x80	/* Command/Response bit */
52 #define AX25_EBIT			0x01	/* HDLC Address Extension bit */
53 #define AX25_HBIT			0x80	/* Has been repeated bit */
54 
55 #define AX25_SSSID_SPARE		0x60	/* Unused bits in SSID for standard AX.25 */
56 #define AX25_ESSID_SPARE		0x20	/* Unused bits in SSID for extended AX.25 */
57 #define AX25_DAMA_FLAG			0x20	/* Well, it is *NOT* unused! (dl1bke 951121 */
58 
59 #define	AX25_COND_ACK_PENDING		0x01
60 #define	AX25_COND_REJECT		0x02
61 #define	AX25_COND_PEER_RX_BUSY		0x04
62 #define	AX25_COND_OWN_RX_BUSY		0x08
63 #define	AX25_COND_DAMA_MODE		0x10
64 
65 #ifndef _LINUX_NETDEVICE_H
66 #include <linux/netdevice.h>
67 #endif
68 
69 /* Upper sub-layer (LAPB) definitions */
70 
71 /* Control field templates */
72 #define	AX25_I			0x00	/* Information frames */
73 #define	AX25_S			0x01	/* Supervisory frames */
74 #define	AX25_RR			0x01	/* Receiver ready */
75 #define	AX25_RNR		0x05	/* Receiver not ready */
76 #define	AX25_REJ		0x09	/* Reject */
77 #define	AX25_U			0x03	/* Unnumbered frames */
78 #define	AX25_SABM		0x2f	/* Set Asynchronous Balanced Mode */
79 #define	AX25_SABME		0x6f	/* Set Asynchronous Balanced Mode Extended */
80 #define	AX25_DISC		0x43	/* Disconnect */
81 #define	AX25_DM			0x0f	/* Disconnected mode */
82 #define	AX25_UA			0x63	/* Unnumbered acknowledge */
83 #define	AX25_FRMR		0x87	/* Frame reject */
84 #define	AX25_UI			0x03	/* Unnumbered information */
85 #define	AX25_XID		0xaf	/* Exchange information */
86 #define	AX25_TEST		0xe3	/* Test */
87 
88 #define	AX25_PF			0x10	/* Poll/final bit for standard AX.25 */
89 #define	AX25_EPF		0x01	/* Poll/final bit for extended AX.25 */
90 
91 #define AX25_ILLEGAL		0x100	/* Impossible to be a real frame type */
92 
93 #define	AX25_POLLOFF		0
94 #define	AX25_POLLON		1
95 
96 /* AX25 L2 C-bit */
97 #define AX25_COMMAND		1
98 #define AX25_RESPONSE		2
99 
100 /* Define Link State constants. */
101 
102 enum {
103 	AX25_STATE_0,			/* Listening */
104 	AX25_STATE_1,			/* SABM sent */
105 	AX25_STATE_2,			/* DISC sent */
106 	AX25_STATE_3,			/* Established */
107 	AX25_STATE_4			/* Recovery */
108 };
109 
110 #define AX25_MODULUS 		8	/*  Standard AX.25 modulus */
111 #define	AX25_EMODULUS		128	/*  Extended AX.25 modulus */
112 
113 enum {
114 	AX25_PROTO_STD_SIMPLEX,
115 	AX25_PROTO_STD_DUPLEX,
116 #ifdef CONFIG_AX25_DAMA_SLAVE
117 	AX25_PROTO_DAMA_SLAVE,
118 #ifdef CONFIG_AX25_DAMA_MASTER
119 	AX25_PROTO_DAMA_MASTER,
120 #define AX25_PROTO_MAX AX25_PROTO_DAMA_MASTER
121 #endif
122 #endif
123 	__AX25_PROTO_MAX,
124 	AX25_PROTO_MAX = __AX25_PROTO_MAX -1
125 };
126 
127 enum {
128 	AX25_VALUES_IPDEFMODE,	/* 0=DG 1=VC */
129 	AX25_VALUES_AXDEFMODE,	/* 0=Normal 1=Extended Seq Nos */
130 	AX25_VALUES_BACKOFF,	/* 0=None 1=Linear 2=Exponential */
131 	AX25_VALUES_CONMODE,	/* Allow connected modes - 0=No 1=no "PID text" 2=all PIDs */
132 	AX25_VALUES_WINDOW,	/* Default window size for standard AX.25 */
133 	AX25_VALUES_EWINDOW,	/* Default window size for extended AX.25 */
134 	AX25_VALUES_T1,		/* Default T1 timeout value */
135 	AX25_VALUES_T2,		/* Default T2 timeout value */
136 	AX25_VALUES_T3,		/* Default T3 timeout value */
137 	AX25_VALUES_IDLE,	/* Connected mode idle timer */
138 	AX25_VALUES_N2,		/* Default N2 value */
139 	AX25_VALUES_PACLEN,	/* AX.25 MTU */
140 	AX25_VALUES_PROTOCOL,	/* Std AX.25, DAMA Slave, DAMA Master */
141 	AX25_VALUES_DS_TIMEOUT,	/* DAMA Slave timeout */
142 	AX25_MAX_VALUES		/* THIS MUST REMAIN THE LAST ENTRY OF THIS LIST */
143 };
144 
145 #define	AX25_DEF_IPDEFMODE	0			/* Datagram */
146 #define	AX25_DEF_AXDEFMODE	0			/* Normal */
147 #define	AX25_DEF_BACKOFF	1			/* Linear backoff */
148 #define	AX25_DEF_CONMODE	2			/* Connected mode allowed */
149 #define	AX25_DEF_WINDOW		2			/* Window=2 */
150 #define	AX25_DEF_EWINDOW	32			/* Module-128 Window=32 */
151 #define	AX25_DEF_T1		10000			/* T1=10s */
152 #define	AX25_DEF_T2		3000			/* T2=3s  */
153 #define	AX25_DEF_T3		300000			/* T3=300s */
154 #define	AX25_DEF_N2		10			/* N2=10 */
155 #define AX25_DEF_IDLE		0			/* Idle=None */
156 #define AX25_DEF_PACLEN		256			/* Paclen=256 */
157 #define	AX25_DEF_PROTOCOL	AX25_PROTO_STD_SIMPLEX	/* Standard AX.25 */
158 #define AX25_DEF_DS_TIMEOUT	180000			/* DAMA timeout 3 minutes */
159 
160 typedef struct ax25_uid_assoc {
161 	struct hlist_node	uid_node;
162 	refcount_t		refcount;
163 	kuid_t			uid;
164 	ax25_address		call;
165 } ax25_uid_assoc;
166 
167 #define ax25_uid_for_each(__ax25, list) \
168 	hlist_for_each_entry(__ax25, list, uid_node)
169 
170 #define ax25_uid_hold(ax25) \
171 	refcount_inc(&((ax25)->refcount))
172 
173 static inline void ax25_uid_put(ax25_uid_assoc *assoc)
174 {
175 	if (refcount_dec_and_test(&assoc->refcount)) {
176 		kfree(assoc);
177 	}
178 }
179 
180 typedef struct {
181 	ax25_address		calls[AX25_MAX_DIGIS];
182 	unsigned char		repeated[AX25_MAX_DIGIS];
183 	unsigned char		ndigi;
184 	signed char		lastrepeat;
185 } ax25_digi;
186 
187 typedef struct ax25_route {
188 	struct ax25_route	*next;
189 	refcount_t		refcount;
190 	ax25_address		callsign;
191 	struct net_device	*dev;
192 	ax25_digi		*digipeat;
193 	char			ip_mode;
194 } ax25_route;
195 
196 static inline void ax25_hold_route(ax25_route *ax25_rt)
197 {
198 	refcount_inc(&ax25_rt->refcount);
199 }
200 
201 void __ax25_put_route(ax25_route *ax25_rt);
202 
203 static inline void ax25_put_route(ax25_route *ax25_rt)
204 {
205 	if (refcount_dec_and_test(&ax25_rt->refcount))
206 		__ax25_put_route(ax25_rt);
207 }
208 
209 typedef struct {
210 	char			slave;			/* slave_mode?   */
211 	struct timer_list	slave_timer;		/* timeout timer */
212 	unsigned short		slave_timeout;		/* when? */
213 } ax25_dama_info;
214 
215 struct ctl_table;
216 
217 typedef struct ax25_dev {
218 	struct ax25_dev		*next;
219 	struct net_device	*dev;
220 	struct net_device	*forward;
221 	struct ctl_table_header *sysheader;
222 	int			values[AX25_MAX_VALUES];
223 #if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
224 	ax25_dama_info		dama;
225 #endif
226 } ax25_dev;
227 
228 typedef struct ax25_cb {
229 	struct hlist_node	ax25_node;
230 	ax25_address		source_addr, dest_addr;
231 	ax25_digi		*digipeat;
232 	ax25_dev		*ax25_dev;
233 	unsigned char		iamdigi;
234 	unsigned char		state, modulus, pidincl;
235 	unsigned short		vs, vr, va;
236 	unsigned char		condition, backoff;
237 	unsigned char		n2, n2count;
238 	struct timer_list	t1timer, t2timer, t3timer, idletimer;
239 	unsigned long		t1, t2, t3, idle, rtt;
240 	unsigned short		paclen, fragno, fraglen;
241 	struct sk_buff_head	write_queue;
242 	struct sk_buff_head	reseq_queue;
243 	struct sk_buff_head	ack_queue;
244 	struct sk_buff_head	frag_queue;
245 	unsigned char		window;
246 	struct timer_list	timer, dtimer;
247 	struct sock		*sk;		/* Backlink to socket */
248 	refcount_t		refcount;
249 } ax25_cb;
250 
251 struct ax25_sock {
252 	struct sock		sk;
253 	struct ax25_cb		*cb;
254 };
255 
256 static inline struct ax25_sock *ax25_sk(const struct sock *sk)
257 {
258 	return (struct ax25_sock *) sk;
259 }
260 
261 static inline struct ax25_cb *sk_to_ax25(const struct sock *sk)
262 {
263 	return ax25_sk(sk)->cb;
264 }
265 
266 #define ax25_for_each(__ax25, list) \
267 	hlist_for_each_entry(__ax25, list, ax25_node)
268 
269 #define ax25_cb_hold(__ax25) \
270 	refcount_inc(&((__ax25)->refcount))
271 
272 static __inline__ void ax25_cb_put(ax25_cb *ax25)
273 {
274 	if (refcount_dec_and_test(&ax25->refcount)) {
275 		kfree(ax25->digipeat);
276 		kfree(ax25);
277 	}
278 }
279 
280 static inline __be16 ax25_type_trans(struct sk_buff *skb, struct net_device *dev)
281 {
282 	skb->dev      = dev;
283 	skb_reset_mac_header(skb);
284 	skb->pkt_type = PACKET_HOST;
285 	return htons(ETH_P_AX25);
286 }
287 
288 /* af_ax25.c */
289 extern struct hlist_head ax25_list;
290 extern spinlock_t ax25_list_lock;
291 void ax25_cb_add(ax25_cb *);
292 struct sock *ax25_find_listener(ax25_address *, int, struct net_device *, int);
293 struct sock *ax25_get_socket(ax25_address *, ax25_address *, int);
294 ax25_cb *ax25_find_cb(ax25_address *, ax25_address *, ax25_digi *,
295 		      struct net_device *);
296 void ax25_send_to_raw(ax25_address *, struct sk_buff *, int);
297 void ax25_destroy_socket(ax25_cb *);
298 ax25_cb * __must_check ax25_create_cb(void);
299 void ax25_fillin_cb(ax25_cb *, ax25_dev *);
300 struct sock *ax25_make_new(struct sock *, struct ax25_dev *);
301 
302 /* ax25_addr.c */
303 extern const ax25_address ax25_bcast;
304 extern const ax25_address ax25_defaddr;
305 extern const ax25_address null_ax25_address;
306 char *ax2asc(char *buf, const ax25_address *);
307 void asc2ax(ax25_address *addr, const char *callsign);
308 int ax25cmp(const ax25_address *, const ax25_address *);
309 int ax25digicmp(const ax25_digi *, const ax25_digi *);
310 const unsigned char *ax25_addr_parse(const unsigned char *, int,
311 	ax25_address *, ax25_address *, ax25_digi *, int *, int *);
312 int ax25_addr_build(unsigned char *, const ax25_address *,
313 		    const ax25_address *, const ax25_digi *, int, int);
314 int ax25_addr_size(const ax25_digi *);
315 void ax25_digi_invert(const ax25_digi *, ax25_digi *);
316 
317 /* ax25_dev.c */
318 extern ax25_dev *ax25_dev_list;
319 extern spinlock_t ax25_dev_lock;
320 
321 static inline ax25_dev *ax25_dev_ax25dev(struct net_device *dev)
322 {
323 	return dev->ax25_ptr;
324 }
325 
326 ax25_dev *ax25_addr_ax25dev(ax25_address *);
327 void ax25_dev_device_up(struct net_device *);
328 void ax25_dev_device_down(struct net_device *);
329 int ax25_fwd_ioctl(unsigned int, struct ax25_fwd_struct *);
330 struct net_device *ax25_fwd_dev(struct net_device *);
331 void ax25_dev_free(void);
332 
333 /* ax25_ds_in.c */
334 int ax25_ds_frame_in(ax25_cb *, struct sk_buff *, int);
335 
336 /* ax25_ds_subr.c */
337 void ax25_ds_nr_error_recovery(ax25_cb *);
338 void ax25_ds_enquiry_response(ax25_cb *);
339 void ax25_ds_establish_data_link(ax25_cb *);
340 void ax25_dev_dama_off(ax25_dev *);
341 void ax25_dama_on(ax25_cb *);
342 void ax25_dama_off(ax25_cb *);
343 
344 /* ax25_ds_timer.c */
345 void ax25_ds_setup_timer(ax25_dev *);
346 void ax25_ds_set_timer(ax25_dev *);
347 void ax25_ds_del_timer(ax25_dev *);
348 void ax25_ds_timer(ax25_cb *);
349 void ax25_ds_t1_timeout(ax25_cb *);
350 void ax25_ds_heartbeat_expiry(ax25_cb *);
351 void ax25_ds_t3timer_expiry(ax25_cb *);
352 void ax25_ds_idletimer_expiry(ax25_cb *);
353 
354 /* ax25_iface.c */
355 
356 struct ax25_protocol {
357 	struct ax25_protocol *next;
358 	unsigned int pid;
359 	int (*func)(struct sk_buff *, ax25_cb *);
360 };
361 
362 void ax25_register_pid(struct ax25_protocol *ap);
363 void ax25_protocol_release(unsigned int);
364 
365 struct ax25_linkfail {
366 	struct hlist_node lf_node;
367 	void (*func)(ax25_cb *, int);
368 };
369 
370 void ax25_linkfail_register(struct ax25_linkfail *lf);
371 void ax25_linkfail_release(struct ax25_linkfail *lf);
372 int __must_check ax25_listen_register(ax25_address *, struct net_device *);
373 void ax25_listen_release(ax25_address *, struct net_device *);
374 int(*ax25_protocol_function(unsigned int))(struct sk_buff *, ax25_cb *);
375 int ax25_listen_mine(ax25_address *, struct net_device *);
376 void ax25_link_failed(ax25_cb *, int);
377 int ax25_protocol_is_registered(unsigned int);
378 
379 /* ax25_in.c */
380 int ax25_rx_iframe(ax25_cb *, struct sk_buff *);
381 int ax25_kiss_rcv(struct sk_buff *, struct net_device *, struct packet_type *,
382 		  struct net_device *);
383 
384 /* ax25_ip.c */
385 netdev_tx_t ax25_ip_xmit(struct sk_buff *skb);
386 extern const struct header_ops ax25_header_ops;
387 
388 /* ax25_out.c */
389 ax25_cb *ax25_send_frame(struct sk_buff *, int, ax25_address *, ax25_address *,
390 			 ax25_digi *, struct net_device *);
391 void ax25_output(ax25_cb *, int, struct sk_buff *);
392 void ax25_kick(ax25_cb *);
393 void ax25_transmit_buffer(ax25_cb *, struct sk_buff *, int);
394 void ax25_queue_xmit(struct sk_buff *skb, struct net_device *dev);
395 int ax25_check_iframes_acked(ax25_cb *, unsigned short);
396 
397 /* ax25_route.c */
398 void ax25_rt_device_down(struct net_device *);
399 int ax25_rt_ioctl(unsigned int, void __user *);
400 extern const struct file_operations ax25_route_fops;
401 ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev);
402 int ax25_rt_autobind(ax25_cb *, ax25_address *);
403 struct sk_buff *ax25_rt_build_path(struct sk_buff *, ax25_address *,
404 				   ax25_address *, ax25_digi *);
405 void ax25_rt_free(void);
406 
407 /* ax25_std_in.c */
408 int ax25_std_frame_in(ax25_cb *, struct sk_buff *, int);
409 
410 /* ax25_std_subr.c */
411 void ax25_std_nr_error_recovery(ax25_cb *);
412 void ax25_std_establish_data_link(ax25_cb *);
413 void ax25_std_transmit_enquiry(ax25_cb *);
414 void ax25_std_enquiry_response(ax25_cb *);
415 void ax25_std_timeout_response(ax25_cb *);
416 
417 /* ax25_std_timer.c */
418 void ax25_std_heartbeat_expiry(ax25_cb *);
419 void ax25_std_t1timer_expiry(ax25_cb *);
420 void ax25_std_t2timer_expiry(ax25_cb *);
421 void ax25_std_t3timer_expiry(ax25_cb *);
422 void ax25_std_idletimer_expiry(ax25_cb *);
423 
424 /* ax25_subr.c */
425 void ax25_clear_queues(ax25_cb *);
426 void ax25_frames_acked(ax25_cb *, unsigned short);
427 void ax25_requeue_frames(ax25_cb *);
428 int ax25_validate_nr(ax25_cb *, unsigned short);
429 int ax25_decode(ax25_cb *, struct sk_buff *, int *, int *, int *);
430 void ax25_send_control(ax25_cb *, int, int, int);
431 void ax25_return_dm(struct net_device *, ax25_address *, ax25_address *,
432 		    ax25_digi *);
433 void ax25_calculate_t1(ax25_cb *);
434 void ax25_calculate_rtt(ax25_cb *);
435 void ax25_disconnect(ax25_cb *, int);
436 
437 /* ax25_timer.c */
438 void ax25_setup_timers(ax25_cb *);
439 void ax25_start_heartbeat(ax25_cb *);
440 void ax25_start_t1timer(ax25_cb *);
441 void ax25_start_t2timer(ax25_cb *);
442 void ax25_start_t3timer(ax25_cb *);
443 void ax25_start_idletimer(ax25_cb *);
444 void ax25_stop_heartbeat(ax25_cb *);
445 void ax25_stop_t1timer(ax25_cb *);
446 void ax25_stop_t2timer(ax25_cb *);
447 void ax25_stop_t3timer(ax25_cb *);
448 void ax25_stop_idletimer(ax25_cb *);
449 int ax25_t1timer_running(ax25_cb *);
450 unsigned long ax25_display_timer(struct timer_list *);
451 
452 /* ax25_uid.c */
453 extern int  ax25_uid_policy;
454 ax25_uid_assoc *ax25_findbyuid(kuid_t);
455 int __must_check ax25_uid_ioctl(int, struct sockaddr_ax25 *);
456 extern const struct file_operations ax25_uid_fops;
457 void ax25_uid_free(void);
458 
459 /* sysctl_net_ax25.c */
460 #ifdef CONFIG_SYSCTL
461 int ax25_register_dev_sysctl(ax25_dev *ax25_dev);
462 void ax25_unregister_dev_sysctl(ax25_dev *ax25_dev);
463 #else
464 static inline int ax25_register_dev_sysctl(ax25_dev *ax25_dev) { return 0; }
465 static inline void ax25_unregister_dev_sysctl(ax25_dev *ax25_dev) {}
466 #endif /* CONFIG_SYSCTL */
467 
468 #endif
469