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  
ax25_uid_put(ax25_uid_assoc * assoc)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  
ax25_route_lock_use(void)200  static inline void ax25_route_lock_use(void)
201  {
202  	read_lock(&ax25_route_lock);
203  }
204  
ax25_route_lock_unuse(void)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  #define ax25_sk(ptr) container_of_const(ptr, struct ax25_sock, sk)
264  
sk_to_ax25(const struct sock * sk)265  static inline struct ax25_cb *sk_to_ax25(const struct sock *sk)
266  {
267  	return ax25_sk(sk)->cb;
268  }
269  
270  #define ax25_for_each(__ax25, list) \
271  	hlist_for_each_entry(__ax25, list, ax25_node)
272  
273  #define ax25_cb_hold(__ax25) \
274  	refcount_inc(&((__ax25)->refcount))
275  
ax25_cb_put(ax25_cb * ax25)276  static __inline__ void ax25_cb_put(ax25_cb *ax25)
277  {
278  	if (refcount_dec_and_test(&ax25->refcount)) {
279  		kfree(ax25->digipeat);
280  		kfree(ax25);
281  	}
282  }
283  
ax25_dev_hold(ax25_dev * ax25_dev)284  static inline void ax25_dev_hold(ax25_dev *ax25_dev)
285  {
286  	refcount_inc(&ax25_dev->refcount);
287  }
288  
ax25_dev_put(ax25_dev * ax25_dev)289  static inline void ax25_dev_put(ax25_dev *ax25_dev)
290  {
291  	if (refcount_dec_and_test(&ax25_dev->refcount)) {
292  		kfree(ax25_dev);
293  	}
294  }
ax25_type_trans(struct sk_buff * skb,struct net_device * dev)295  static inline __be16 ax25_type_trans(struct sk_buff *skb, struct net_device *dev)
296  {
297  	skb->dev      = dev;
298  	skb_reset_mac_header(skb);
299  	skb->pkt_type = PACKET_HOST;
300  	return htons(ETH_P_AX25);
301  }
302  
303  /* af_ax25.c */
304  extern struct hlist_head ax25_list;
305  extern spinlock_t ax25_list_lock;
306  void ax25_cb_add(ax25_cb *);
307  struct sock *ax25_find_listener(ax25_address *, int, struct net_device *, int);
308  struct sock *ax25_get_socket(ax25_address *, ax25_address *, int);
309  ax25_cb *ax25_find_cb(const ax25_address *, ax25_address *, ax25_digi *,
310  		      struct net_device *);
311  void ax25_send_to_raw(ax25_address *, struct sk_buff *, int);
312  void ax25_destroy_socket(ax25_cb *);
313  ax25_cb * __must_check ax25_create_cb(void);
314  void ax25_fillin_cb(ax25_cb *, ax25_dev *);
315  struct sock *ax25_make_new(struct sock *, struct ax25_dev *);
316  
317  /* ax25_addr.c */
318  extern const ax25_address ax25_bcast;
319  extern const ax25_address ax25_defaddr;
320  extern const ax25_address null_ax25_address;
321  char *ax2asc(char *buf, const ax25_address *);
322  void asc2ax(ax25_address *addr, const char *callsign);
323  int ax25cmp(const ax25_address *, const ax25_address *);
324  int ax25digicmp(const ax25_digi *, const ax25_digi *);
325  const unsigned char *ax25_addr_parse(const unsigned char *, int,
326  	ax25_address *, ax25_address *, ax25_digi *, int *, int *);
327  int ax25_addr_build(unsigned char *, const ax25_address *,
328  		    const ax25_address *, const ax25_digi *, int, int);
329  int ax25_addr_size(const ax25_digi *);
330  void ax25_digi_invert(const ax25_digi *, ax25_digi *);
331  
332  /* ax25_dev.c */
333  extern ax25_dev *ax25_dev_list;
334  extern spinlock_t ax25_dev_lock;
335  
336  #if IS_ENABLED(CONFIG_AX25)
ax25_dev_ax25dev(struct net_device * dev)337  static inline ax25_dev *ax25_dev_ax25dev(struct net_device *dev)
338  {
339  	return dev->ax25_ptr;
340  }
341  #endif
342  
343  ax25_dev *ax25_addr_ax25dev(ax25_address *);
344  void ax25_dev_device_up(struct net_device *);
345  void ax25_dev_device_down(struct net_device *);
346  int ax25_fwd_ioctl(unsigned int, struct ax25_fwd_struct *);
347  struct net_device *ax25_fwd_dev(struct net_device *);
348  void ax25_dev_free(void);
349  
350  /* ax25_ds_in.c */
351  int ax25_ds_frame_in(ax25_cb *, struct sk_buff *, int);
352  
353  /* ax25_ds_subr.c */
354  void ax25_ds_nr_error_recovery(ax25_cb *);
355  void ax25_ds_enquiry_response(ax25_cb *);
356  void ax25_ds_establish_data_link(ax25_cb *);
357  void ax25_dev_dama_off(ax25_dev *);
358  void ax25_dama_on(ax25_cb *);
359  void ax25_dama_off(ax25_cb *);
360  
361  /* ax25_ds_timer.c */
362  void ax25_ds_setup_timer(ax25_dev *);
363  void ax25_ds_set_timer(ax25_dev *);
364  void ax25_ds_del_timer(ax25_dev *);
365  void ax25_ds_timer(ax25_cb *);
366  void ax25_ds_t1_timeout(ax25_cb *);
367  void ax25_ds_heartbeat_expiry(ax25_cb *);
368  void ax25_ds_t3timer_expiry(ax25_cb *);
369  void ax25_ds_idletimer_expiry(ax25_cb *);
370  
371  /* ax25_iface.c */
372  
373  struct ax25_protocol {
374  	struct ax25_protocol *next;
375  	unsigned int pid;
376  	int (*func)(struct sk_buff *, ax25_cb *);
377  };
378  
379  void ax25_register_pid(struct ax25_protocol *ap);
380  void ax25_protocol_release(unsigned int);
381  
382  struct ax25_linkfail {
383  	struct hlist_node lf_node;
384  	void (*func)(ax25_cb *, int);
385  };
386  
387  void ax25_linkfail_register(struct ax25_linkfail *lf);
388  void ax25_linkfail_release(struct ax25_linkfail *lf);
389  int __must_check ax25_listen_register(const ax25_address *,
390  				      struct net_device *);
391  void ax25_listen_release(const ax25_address *, struct net_device *);
392  int(*ax25_protocol_function(unsigned int))(struct sk_buff *, ax25_cb *);
393  int ax25_listen_mine(const ax25_address *, struct net_device *);
394  void ax25_link_failed(ax25_cb *, int);
395  int ax25_protocol_is_registered(unsigned int);
396  
397  /* ax25_in.c */
398  int ax25_rx_iframe(ax25_cb *, struct sk_buff *);
399  int ax25_kiss_rcv(struct sk_buff *, struct net_device *, struct packet_type *,
400  		  struct net_device *);
401  
402  /* ax25_ip.c */
403  netdev_tx_t ax25_ip_xmit(struct sk_buff *skb);
404  extern const struct header_ops ax25_header_ops;
405  
406  /* ax25_out.c */
407  ax25_cb *ax25_send_frame(struct sk_buff *, int, const ax25_address *,
408  			 ax25_address *, ax25_digi *, struct net_device *);
409  void ax25_output(ax25_cb *, int, struct sk_buff *);
410  void ax25_kick(ax25_cb *);
411  void ax25_transmit_buffer(ax25_cb *, struct sk_buff *, int);
412  void ax25_queue_xmit(struct sk_buff *skb, struct net_device *dev);
413  int ax25_check_iframes_acked(ax25_cb *, unsigned short);
414  
415  /* ax25_route.c */
416  void ax25_rt_device_down(struct net_device *);
417  int ax25_rt_ioctl(unsigned int, void __user *);
418  extern const struct seq_operations ax25_rt_seqops;
419  ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev);
420  int ax25_rt_autobind(ax25_cb *, ax25_address *);
421  struct sk_buff *ax25_rt_build_path(struct sk_buff *, ax25_address *,
422  				   ax25_address *, ax25_digi *);
423  void ax25_rt_free(void);
424  
425  /* ax25_std_in.c */
426  int ax25_std_frame_in(ax25_cb *, struct sk_buff *, int);
427  
428  /* ax25_std_subr.c */
429  void ax25_std_nr_error_recovery(ax25_cb *);
430  void ax25_std_establish_data_link(ax25_cb *);
431  void ax25_std_transmit_enquiry(ax25_cb *);
432  void ax25_std_enquiry_response(ax25_cb *);
433  void ax25_std_timeout_response(ax25_cb *);
434  
435  /* ax25_std_timer.c */
436  void ax25_std_heartbeat_expiry(ax25_cb *);
437  void ax25_std_t1timer_expiry(ax25_cb *);
438  void ax25_std_t2timer_expiry(ax25_cb *);
439  void ax25_std_t3timer_expiry(ax25_cb *);
440  void ax25_std_idletimer_expiry(ax25_cb *);
441  
442  /* ax25_subr.c */
443  void ax25_clear_queues(ax25_cb *);
444  void ax25_frames_acked(ax25_cb *, unsigned short);
445  void ax25_requeue_frames(ax25_cb *);
446  int ax25_validate_nr(ax25_cb *, unsigned short);
447  int ax25_decode(ax25_cb *, struct sk_buff *, int *, int *, int *);
448  void ax25_send_control(ax25_cb *, int, int, int);
449  void ax25_return_dm(struct net_device *, ax25_address *, ax25_address *,
450  		    ax25_digi *);
451  void ax25_calculate_t1(ax25_cb *);
452  void ax25_calculate_rtt(ax25_cb *);
453  void ax25_disconnect(ax25_cb *, int);
454  
455  /* ax25_timer.c */
456  void ax25_setup_timers(ax25_cb *);
457  void ax25_start_heartbeat(ax25_cb *);
458  void ax25_start_t1timer(ax25_cb *);
459  void ax25_start_t2timer(ax25_cb *);
460  void ax25_start_t3timer(ax25_cb *);
461  void ax25_start_idletimer(ax25_cb *);
462  void ax25_stop_heartbeat(ax25_cb *);
463  void ax25_stop_t1timer(ax25_cb *);
464  void ax25_stop_t2timer(ax25_cb *);
465  void ax25_stop_t3timer(ax25_cb *);
466  void ax25_stop_idletimer(ax25_cb *);
467  int ax25_t1timer_running(ax25_cb *);
468  unsigned long ax25_display_timer(struct timer_list *);
469  
470  /* ax25_uid.c */
471  extern int  ax25_uid_policy;
472  ax25_uid_assoc *ax25_findbyuid(kuid_t);
473  int __must_check ax25_uid_ioctl(int, struct sockaddr_ax25 *);
474  extern const struct seq_operations ax25_uid_seqops;
475  void ax25_uid_free(void);
476  
477  /* sysctl_net_ax25.c */
478  #ifdef CONFIG_SYSCTL
479  int ax25_register_dev_sysctl(ax25_dev *ax25_dev);
480  void ax25_unregister_dev_sysctl(ax25_dev *ax25_dev);
481  #else
ax25_register_dev_sysctl(ax25_dev * ax25_dev)482  static inline int ax25_register_dev_sysctl(ax25_dev *ax25_dev) { return 0; }
ax25_unregister_dev_sysctl(ax25_dev * ax25_dev)483  static inline void ax25_unregister_dev_sysctl(ax25_dev *ax25_dev) {}
484  #endif /* CONFIG_SYSCTL */
485  
486  #endif
487