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. */
52enum {
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 */
72struct 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 */
83struct 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 */
112void lapb_connect_confirmation(struct lapb_cb *lapb, int);
113void lapb_connect_indication(struct lapb_cb *lapb, int);
114void lapb_disconnect_confirmation(struct lapb_cb *lapb, int);
115void lapb_disconnect_indication(struct lapb_cb *lapb, int);
116int lapb_data_indication(struct lapb_cb *lapb, struct sk_buff *);
117int lapb_data_transmit(struct lapb_cb *lapb, struct sk_buff *);
118
119/* lapb_in.c */
120void lapb_data_input(struct lapb_cb *lapb, struct sk_buff *);
121
122/* lapb_out.c */
123void lapb_kick(struct lapb_cb *lapb);
124void lapb_transmit_buffer(struct lapb_cb *lapb, struct sk_buff *, int);
125void lapb_establish_data_link(struct lapb_cb *lapb);
126void lapb_enquiry_response(struct lapb_cb *lapb);
127void lapb_timeout_response(struct lapb_cb *lapb);
128void lapb_check_iframes_acked(struct lapb_cb *lapb, unsigned short);
129void lapb_check_need_response(struct lapb_cb *lapb, int, int);
130
131/* lapb_subr.c */
132void lapb_clear_queues(struct lapb_cb *lapb);
133void lapb_frames_acked(struct lapb_cb *lapb, unsigned short);
134void lapb_requeue_frames(struct lapb_cb *lapb);
135int lapb_validate_nr(struct lapb_cb *lapb, unsigned short);
136int lapb_decode(struct lapb_cb *lapb, struct sk_buff *, struct lapb_frame *);
137void lapb_send_control(struct lapb_cb *lapb, int, int, int);
138void lapb_transmit_frmr(struct lapb_cb *lapb);
139
140/* lapb_timer.c */
141void lapb_start_t1timer(struct lapb_cb *lapb);
142void lapb_start_t2timer(struct lapb_cb *lapb);
143void lapb_stop_t1timer(struct lapb_cb *lapb);
144void lapb_stop_t2timer(struct lapb_cb *lapb);
145int 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, ...)			\
157do {							\
158	if (level < LAPB_DEBUG)				\
159		pr_debug(fmt, ##__VA_ARGS__);		\
160} while (0)
161
162#endif
163