1  /* SPDX-License-Identifier: GPL-2.0 */
2  #ifndef _LAPB_H
3  #define _LAPB_H
4  #include <linux/lapb.h>
5  #include <linux/refcount.h>
6  
7  #define	LAPB_HEADER_LEN	20		/* LAPB over Ethernet + a bit more */
8  
9  #define	LAPB_ACK_PENDING_CONDITION	0x01
10  #define	LAPB_REJECT_CONDITION		0x02
11  #define	LAPB_PEER_RX_BUSY_CONDITION	0x04
12  
13  /* Control field templates */
14  #define	LAPB_I		0x00	/* Information frames */
15  #define	LAPB_S		0x01	/* Supervisory frames */
16  #define	LAPB_U		0x03	/* Unnumbered frames */
17  
18  #define	LAPB_RR		0x01	/* Receiver ready */
19  #define	LAPB_RNR	0x05	/* Receiver not ready */
20  #define	LAPB_REJ	0x09	/* Reject */
21  
22  #define	LAPB_SABM	0x2F	/* Set Asynchronous Balanced Mode */
23  #define	LAPB_SABME	0x6F	/* Set Asynchronous Balanced Mode Extended */
24  #define	LAPB_DISC	0x43	/* Disconnect */
25  #define	LAPB_DM		0x0F	/* Disconnected mode */
26  #define	LAPB_UA		0x63	/* Unnumbered acknowledge */
27  #define	LAPB_FRMR	0x87	/* Frame reject */
28  
29  #define LAPB_ILLEGAL	0x100	/* Impossible to be a real frame type */
30  
31  #define	LAPB_SPF	0x10	/* Poll/final bit for standard LAPB */
32  #define	LAPB_EPF	0x01	/* Poll/final bit for extended LAPB */
33  
34  #define	LAPB_FRMR_W	0x01	/* Control field invalid	*/
35  #define	LAPB_FRMR_X	0x02	/* I field invalid		*/
36  #define	LAPB_FRMR_Y	0x04	/* I field too long		*/
37  #define	LAPB_FRMR_Z	0x08	/* Invalid N(R)			*/
38  
39  #define	LAPB_POLLOFF	0
40  #define	LAPB_POLLON	1
41  
42  /* LAPB C-bit */
43  #define LAPB_COMMAND	1
44  #define LAPB_RESPONSE	2
45  
46  #define	LAPB_ADDR_A	0x03
47  #define	LAPB_ADDR_B	0x01
48  #define	LAPB_ADDR_C	0x0F
49  #define	LAPB_ADDR_D	0x07
50  
51  /* Define Link State constants. */
52  enum {
53  	LAPB_STATE_0,	/* Disconnected State		*/
54  	LAPB_STATE_1,	/* Awaiting Connection State	*/
55  	LAPB_STATE_2,	/* Awaiting Disconnection State	*/
56  	LAPB_STATE_3,	/* Data Transfer State		*/
57  	LAPB_STATE_4	/* Frame Reject State		*/
58  };
59  
60  #define	LAPB_DEFAULT_MODE		(LAPB_STANDARD | LAPB_SLP | LAPB_DTE)
61  #define	LAPB_DEFAULT_WINDOW		7		/* Window=7 */
62  #define	LAPB_DEFAULT_T1			(5 * HZ)	/* T1=5s    */
63  #define	LAPB_DEFAULT_T2			(1 * HZ)	/* T2=1s    */
64  #define	LAPB_DEFAULT_N2			20		/* N2=20    */
65  
66  #define	LAPB_SMODULUS	8
67  #define	LAPB_EMODULUS	128
68  
69  /*
70   *	Information about the current frame.
71   */
72  struct lapb_frame {
73  	unsigned short		type;		/* Parsed type		*/
74  	unsigned short		nr, ns;		/* N(R), N(S)		*/
75  	unsigned char		cr;		/* Command/Response	*/
76  	unsigned char		pf;		/* Poll/Final		*/
77  	unsigned char		control[2];	/* Original control data*/
78  };
79  
80  /*
81   *	The per LAPB connection control structure.
82   */
83  struct lapb_cb {
84  	struct list_head	node;
85  	struct net_device	*dev;
86  
87  	/* Link status fields */
88  	unsigned int		mode;
89  	unsigned char		state;
90  	unsigned short		vs, vr, va;
91  	unsigned char		condition;
92  	unsigned short		n2, n2count;
93  	unsigned short		t1, t2;
94  	struct timer_list	t1timer, t2timer;
95  	bool			t1timer_running, t2timer_running;
96  
97  	/* Internal control information */
98  	struct sk_buff_head	write_queue;
99  	struct sk_buff_head	ack_queue;
100  	unsigned char		window;
101  	const struct lapb_register_struct *callbacks;
102  
103  	/* FRMR control information */
104  	struct lapb_frame	frmr_data;
105  	unsigned char		frmr_type;
106  
107  	spinlock_t		lock;
108  	refcount_t		refcnt;
109  };
110  
111  /* lapb_iface.c */
112  void lapb_connect_confirmation(struct lapb_cb *lapb, int);
113  void lapb_connect_indication(struct lapb_cb *lapb, int);
114  void lapb_disconnect_confirmation(struct lapb_cb *lapb, int);
115  void lapb_disconnect_indication(struct lapb_cb *lapb, int);
116  int lapb_data_indication(struct lapb_cb *lapb, struct sk_buff *);
117  int lapb_data_transmit(struct lapb_cb *lapb, struct sk_buff *);
118  
119  /* lapb_in.c */
120  void lapb_data_input(struct lapb_cb *lapb, struct sk_buff *);
121  
122  /* lapb_out.c */
123  void lapb_kick(struct lapb_cb *lapb);
124  void lapb_transmit_buffer(struct lapb_cb *lapb, struct sk_buff *, int);
125  void lapb_establish_data_link(struct lapb_cb *lapb);
126  void lapb_enquiry_response(struct lapb_cb *lapb);
127  void lapb_timeout_response(struct lapb_cb *lapb);
128  void lapb_check_iframes_acked(struct lapb_cb *lapb, unsigned short);
129  void lapb_check_need_response(struct lapb_cb *lapb, int, int);
130  
131  /* lapb_subr.c */
132  void lapb_clear_queues(struct lapb_cb *lapb);
133  void lapb_frames_acked(struct lapb_cb *lapb, unsigned short);
134  void lapb_requeue_frames(struct lapb_cb *lapb);
135  int lapb_validate_nr(struct lapb_cb *lapb, unsigned short);
136  int lapb_decode(struct lapb_cb *lapb, struct sk_buff *, struct lapb_frame *);
137  void lapb_send_control(struct lapb_cb *lapb, int, int, int);
138  void lapb_transmit_frmr(struct lapb_cb *lapb);
139  
140  /* lapb_timer.c */
141  void lapb_start_t1timer(struct lapb_cb *lapb);
142  void lapb_start_t2timer(struct lapb_cb *lapb);
143  void lapb_stop_t1timer(struct lapb_cb *lapb);
144  void lapb_stop_t2timer(struct lapb_cb *lapb);
145  int lapb_t1timer_running(struct lapb_cb *lapb);
146  
147  /*
148   * Debug levels.
149   *	0 = Off
150   *	1 = State Changes
151   *	2 = Packets I/O and State Changes
152   *	3 = Hex dumps, Packets I/O and State Changes.
153   */
154  #define	LAPB_DEBUG	0
155  
156  #define lapb_dbg(level, fmt, ...)			\
157  do {							\
158  	if (level < LAPB_DEBUG)				\
159  		pr_debug(fmt, ##__VA_ARGS__);		\
160  } while (0)
161  
162  #endif
163