xref: /linux/include/net/ax25.h (revision c717993dd76a1049093af5c262e751d901b8da10)
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  	refcount_t		refcount;
191  	ax25_address		callsign;
192  	struct net_device	*dev;
193  	ax25_digi		*digipeat;
194  	char			ip_mode;
195  } ax25_route;
196  
197  static inline void ax25_hold_route(ax25_route *ax25_rt)
198  {
199  	refcount_inc(&ax25_rt->refcount);
200  }
201  
202  void __ax25_put_route(ax25_route *ax25_rt);
203  
204  extern rwlock_t ax25_route_lock;
205  
206  static inline void ax25_route_lock_use(void)
207  {
208  	read_lock(&ax25_route_lock);
209  }
210  
211  static inline void ax25_route_lock_unuse(void)
212  {
213  	read_unlock(&ax25_route_lock);
214  }
215  
216  static inline void ax25_put_route(ax25_route *ax25_rt)
217  {
218  	if (refcount_dec_and_test(&ax25_rt->refcount))
219  		__ax25_put_route(ax25_rt);
220  }
221  
222  typedef struct {
223  	char			slave;			/* slave_mode?   */
224  	struct timer_list	slave_timer;		/* timeout timer */
225  	unsigned short		slave_timeout;		/* when? */
226  } ax25_dama_info;
227  
228  struct ctl_table;
229  
230  typedef struct ax25_dev {
231  	struct ax25_dev		*next;
232  
233  	struct net_device	*dev;
234  	netdevice_tracker	dev_tracker;
235  
236  	struct net_device	*forward;
237  	struct ctl_table_header *sysheader;
238  	int			values[AX25_MAX_VALUES];
239  #if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
240  	ax25_dama_info		dama;
241  #endif
242  } ax25_dev;
243  
244  typedef struct ax25_cb {
245  	struct hlist_node	ax25_node;
246  	ax25_address		source_addr, dest_addr;
247  	ax25_digi		*digipeat;
248  	ax25_dev		*ax25_dev;
249  	unsigned char		iamdigi;
250  	unsigned char		state, modulus, pidincl;
251  	unsigned short		vs, vr, va;
252  	unsigned char		condition, backoff;
253  	unsigned char		n2, n2count;
254  	struct timer_list	t1timer, t2timer, t3timer, idletimer;
255  	unsigned long		t1, t2, t3, idle, rtt;
256  	unsigned short		paclen, fragno, fraglen;
257  	struct sk_buff_head	write_queue;
258  	struct sk_buff_head	reseq_queue;
259  	struct sk_buff_head	ack_queue;
260  	struct sk_buff_head	frag_queue;
261  	unsigned char		window;
262  	struct timer_list	timer, dtimer;
263  	struct sock		*sk;		/* Backlink to socket */
264  	refcount_t		refcount;
265  } ax25_cb;
266  
267  struct ax25_sock {
268  	struct sock		sk;
269  	struct ax25_cb		*cb;
270  };
271  
272  static inline struct ax25_sock *ax25_sk(const struct sock *sk)
273  {
274  	return (struct ax25_sock *) sk;
275  }
276  
277  static inline struct ax25_cb *sk_to_ax25(const struct sock *sk)
278  {
279  	return ax25_sk(sk)->cb;
280  }
281  
282  #define ax25_for_each(__ax25, list) \
283  	hlist_for_each_entry(__ax25, list, ax25_node)
284  
285  #define ax25_cb_hold(__ax25) \
286  	refcount_inc(&((__ax25)->refcount))
287  
288  static __inline__ void ax25_cb_put(ax25_cb *ax25)
289  {
290  	if (refcount_dec_and_test(&ax25->refcount)) {
291  		kfree(ax25->digipeat);
292  		kfree(ax25);
293  	}
294  }
295  
296  static inline __be16 ax25_type_trans(struct sk_buff *skb, struct net_device *dev)
297  {
298  	skb->dev      = dev;
299  	skb_reset_mac_header(skb);
300  	skb->pkt_type = PACKET_HOST;
301  	return htons(ETH_P_AX25);
302  }
303  
304  /* af_ax25.c */
305  extern struct hlist_head ax25_list;
306  extern spinlock_t ax25_list_lock;
307  void ax25_cb_add(ax25_cb *);
308  struct sock *ax25_find_listener(ax25_address *, int, struct net_device *, int);
309  struct sock *ax25_get_socket(ax25_address *, ax25_address *, int);
310  ax25_cb *ax25_find_cb(const ax25_address *, ax25_address *, ax25_digi *,
311  		      struct net_device *);
312  void ax25_send_to_raw(ax25_address *, struct sk_buff *, int);
313  void ax25_destroy_socket(ax25_cb *);
314  ax25_cb * __must_check ax25_create_cb(void);
315  void ax25_fillin_cb(ax25_cb *, ax25_dev *);
316  struct sock *ax25_make_new(struct sock *, struct ax25_dev *);
317  
318  /* ax25_addr.c */
319  extern const ax25_address ax25_bcast;
320  extern const ax25_address ax25_defaddr;
321  extern const ax25_address null_ax25_address;
322  char *ax2asc(char *buf, const ax25_address *);
323  void asc2ax(ax25_address *addr, const char *callsign);
324  int ax25cmp(const ax25_address *, const ax25_address *);
325  int ax25digicmp(const ax25_digi *, const ax25_digi *);
326  const unsigned char *ax25_addr_parse(const unsigned char *, int,
327  	ax25_address *, ax25_address *, ax25_digi *, int *, int *);
328  int ax25_addr_build(unsigned char *, const ax25_address *,
329  		    const ax25_address *, const ax25_digi *, int, int);
330  int ax25_addr_size(const ax25_digi *);
331  void ax25_digi_invert(const ax25_digi *, ax25_digi *);
332  
333  /* ax25_dev.c */
334  extern ax25_dev *ax25_dev_list;
335  extern spinlock_t ax25_dev_lock;
336  
337  #if IS_ENABLED(CONFIG_AX25)
338  static inline ax25_dev *ax25_dev_ax25dev(struct net_device *dev)
339  {
340  	return dev->ax25_ptr;
341  }
342  #endif
343  
344  ax25_dev *ax25_addr_ax25dev(ax25_address *);
345  void ax25_dev_device_up(struct net_device *);
346  void ax25_dev_device_down(struct net_device *);
347  int ax25_fwd_ioctl(unsigned int, struct ax25_fwd_struct *);
348  struct net_device *ax25_fwd_dev(struct net_device *);
349  void ax25_dev_free(void);
350  
351  /* ax25_ds_in.c */
352  int ax25_ds_frame_in(ax25_cb *, struct sk_buff *, int);
353  
354  /* ax25_ds_subr.c */
355  void ax25_ds_nr_error_recovery(ax25_cb *);
356  void ax25_ds_enquiry_response(ax25_cb *);
357  void ax25_ds_establish_data_link(ax25_cb *);
358  void ax25_dev_dama_off(ax25_dev *);
359  void ax25_dama_on(ax25_cb *);
360  void ax25_dama_off(ax25_cb *);
361  
362  /* ax25_ds_timer.c */
363  void ax25_ds_setup_timer(ax25_dev *);
364  void ax25_ds_set_timer(ax25_dev *);
365  void ax25_ds_del_timer(ax25_dev *);
366  void ax25_ds_timer(ax25_cb *);
367  void ax25_ds_t1_timeout(ax25_cb *);
368  void ax25_ds_heartbeat_expiry(ax25_cb *);
369  void ax25_ds_t3timer_expiry(ax25_cb *);
370  void ax25_ds_idletimer_expiry(ax25_cb *);
371  
372  /* ax25_iface.c */
373  
374  struct ax25_protocol {
375  	struct ax25_protocol *next;
376  	unsigned int pid;
377  	int (*func)(struct sk_buff *, ax25_cb *);
378  };
379  
380  void ax25_register_pid(struct ax25_protocol *ap);
381  void ax25_protocol_release(unsigned int);
382  
383  struct ax25_linkfail {
384  	struct hlist_node lf_node;
385  	void (*func)(ax25_cb *, int);
386  };
387  
388  void ax25_linkfail_register(struct ax25_linkfail *lf);
389  void ax25_linkfail_release(struct ax25_linkfail *lf);
390  int __must_check ax25_listen_register(const ax25_address *,
391  				      struct net_device *);
392  void ax25_listen_release(const ax25_address *, struct net_device *);
393  int(*ax25_protocol_function(unsigned int))(struct sk_buff *, ax25_cb *);
394  int ax25_listen_mine(const ax25_address *, struct net_device *);
395  void ax25_link_failed(ax25_cb *, int);
396  int ax25_protocol_is_registered(unsigned int);
397  
398  /* ax25_in.c */
399  int ax25_rx_iframe(ax25_cb *, struct sk_buff *);
400  int ax25_kiss_rcv(struct sk_buff *, struct net_device *, struct packet_type *,
401  		  struct net_device *);
402  
403  /* ax25_ip.c */
404  netdev_tx_t ax25_ip_xmit(struct sk_buff *skb);
405  extern const struct header_ops ax25_header_ops;
406  
407  /* ax25_out.c */
408  ax25_cb *ax25_send_frame(struct sk_buff *, int, const ax25_address *,
409  			 ax25_address *, ax25_digi *, struct net_device *);
410  void ax25_output(ax25_cb *, int, struct sk_buff *);
411  void ax25_kick(ax25_cb *);
412  void ax25_transmit_buffer(ax25_cb *, struct sk_buff *, int);
413  void ax25_queue_xmit(struct sk_buff *skb, struct net_device *dev);
414  int ax25_check_iframes_acked(ax25_cb *, unsigned short);
415  
416  /* ax25_route.c */
417  void ax25_rt_device_down(struct net_device *);
418  int ax25_rt_ioctl(unsigned int, void __user *);
419  extern const struct seq_operations ax25_rt_seqops;
420  ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev);
421  int ax25_rt_autobind(ax25_cb *, ax25_address *);
422  struct sk_buff *ax25_rt_build_path(struct sk_buff *, ax25_address *,
423  				   ax25_address *, ax25_digi *);
424  void ax25_rt_free(void);
425  
426  /* ax25_std_in.c */
427  int ax25_std_frame_in(ax25_cb *, struct sk_buff *, int);
428  
429  /* ax25_std_subr.c */
430  void ax25_std_nr_error_recovery(ax25_cb *);
431  void ax25_std_establish_data_link(ax25_cb *);
432  void ax25_std_transmit_enquiry(ax25_cb *);
433  void ax25_std_enquiry_response(ax25_cb *);
434  void ax25_std_timeout_response(ax25_cb *);
435  
436  /* ax25_std_timer.c */
437  void ax25_std_heartbeat_expiry(ax25_cb *);
438  void ax25_std_t1timer_expiry(ax25_cb *);
439  void ax25_std_t2timer_expiry(ax25_cb *);
440  void ax25_std_t3timer_expiry(ax25_cb *);
441  void ax25_std_idletimer_expiry(ax25_cb *);
442  
443  /* ax25_subr.c */
444  void ax25_clear_queues(ax25_cb *);
445  void ax25_frames_acked(ax25_cb *, unsigned short);
446  void ax25_requeue_frames(ax25_cb *);
447  int ax25_validate_nr(ax25_cb *, unsigned short);
448  int ax25_decode(ax25_cb *, struct sk_buff *, int *, int *, int *);
449  void ax25_send_control(ax25_cb *, int, int, int);
450  void ax25_return_dm(struct net_device *, ax25_address *, ax25_address *,
451  		    ax25_digi *);
452  void ax25_calculate_t1(ax25_cb *);
453  void ax25_calculate_rtt(ax25_cb *);
454  void ax25_disconnect(ax25_cb *, int);
455  
456  /* ax25_timer.c */
457  void ax25_setup_timers(ax25_cb *);
458  void ax25_start_heartbeat(ax25_cb *);
459  void ax25_start_t1timer(ax25_cb *);
460  void ax25_start_t2timer(ax25_cb *);
461  void ax25_start_t3timer(ax25_cb *);
462  void ax25_start_idletimer(ax25_cb *);
463  void ax25_stop_heartbeat(ax25_cb *);
464  void ax25_stop_t1timer(ax25_cb *);
465  void ax25_stop_t2timer(ax25_cb *);
466  void ax25_stop_t3timer(ax25_cb *);
467  void ax25_stop_idletimer(ax25_cb *);
468  int ax25_t1timer_running(ax25_cb *);
469  unsigned long ax25_display_timer(struct timer_list *);
470  
471  /* ax25_uid.c */
472  extern int  ax25_uid_policy;
473  ax25_uid_assoc *ax25_findbyuid(kuid_t);
474  int __must_check ax25_uid_ioctl(int, struct sockaddr_ax25 *);
475  extern const struct seq_operations ax25_uid_seqops;
476  void ax25_uid_free(void);
477  
478  /* sysctl_net_ax25.c */
479  #ifdef CONFIG_SYSCTL
480  int ax25_register_dev_sysctl(ax25_dev *ax25_dev);
481  void ax25_unregister_dev_sysctl(ax25_dev *ax25_dev);
482  #else
483  static inline int ax25_register_dev_sysctl(ax25_dev *ax25_dev) { return 0; }
484  static inline void ax25_unregister_dev_sysctl(ax25_dev *ax25_dev) {}
485  #endif /* CONFIG_SYSCTL */
486  
487  #endif
488