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
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