xref: /original-bsd/sys/netccitt/hdlc.h (revision a1c2194a)
1 /*-
2  * Copyright (c) University of British Columbia, 1984
3  * Copyright (c) 1991 The Regents of the University of California.
4  * All rights reserved.
5  *
6  * This code is derived from software contributed to Berkeley by the
7  * Laboratory for Computation Vision and the Computer Science Department
8  * of the University of British Columbia.
9  *
10  * %sccs.include.redist.c%
11  *
12  *	@(#)hdlc.h	7.4 (Berkeley) 05/06/91
13  */
14 
15 #ifndef ORDER4
16 #define FALSE   0
17 #define TRUE    1
18 typedef u_char octet;
19 typedef char    bool;
20 
21 /*
22  *  HDLC Packet format definitions
23  *  This will eventually have to be rewritten without reference
24  *  to bit fields, to be compliant with ANSI C and alignment safe.
25  */
26 
27 #if BYTE_ORDER == BIG_ENDIAN
28 #define ORDER4(a, b, c, d) a , b , c , d
29 #define ORDER5(a, b, c, d, e) a , b , c , d , e
30 #endif
31 
32 #if BYTE_ORDER == LITTLE_ENDIAN
33 #define ORDER4(a, b, c, d) d , c , b , a
34 #define ORDER5(a, b, c, d, e) e , d , c , b , a
35 #endif
36 #endif
37 
38 #define MAX_INFO_LEN    4096+3+4
39 #define ADDRESS_A       3	/* B'00000011' */
40 #define ADDRESS_B       1	/* B'00000001' */
41 
42 struct Hdlc_iframe {
43 	octet	address;
44 	octet	ORDER4(nr:3, pf:1, ns:3, hdlc_0:1);
45 	octet    i_field[MAX_INFO_LEN];
46 };
47 
48 struct Hdlc_sframe {
49 	octet	address;
50 	octet	ORDER4(nr:3, pf:1, s2:2, hdlc_01:2);
51 };
52 
53 struct	Hdlc_uframe {
54 	octet	address;
55 	octet	ORDER4(m3:3, pf:1, m2:2, hdlc_11:2);
56 };
57 
58 struct	Frmr_frame {
59 	octet	address;
60 	octet	control;
61 	octet	frmr_control;
62 	octet	ORDER4(frmr_nr:3, frmr_f1_0:1, frmr_ns:3, frmr_f2_0:1);
63 	octet	ORDER5(frmr_0000:4, frmr_z:1, frmr_y:1, frmr_x:1, frmr_w:1);
64 };
65 
66 #define HDHEADERLN	2
67 #define MINFRLN		2		/* Minimum frame length. */
68 
69 struct	Hdlc_frame {
70 	octet	address;
71 	octet	control;
72 	octet	info[3];	/* min for FRMR */
73 };
74 
75 #define SABM_CONTROL 057	/* B'00101111' */
76 #define UA_CONTROL   0143	/* B'01100011' */
77 #define DISC_CONTROL 0103	/* B'01000011' */
78 #define DM_CONTROL   017	/* B'00001111' */
79 #define FRMR_CONTROL 0207	/* B'10000111' */
80 #define RR_CONTROL   01		/* B'00000001' */
81 #define RNR_CONTROL  05		/* B'00000101' */
82 #define REJ_CONTROL  011	/* B'00001001' */
83 
84 #define POLLOFF  0
85 #define POLLON   1
86 
87 /* Define Link State constants. */
88 
89 #define INIT		0
90 #define DM_SENT		1
91 #define SABM_SENT	2
92 #define ABM		3
93 #define WAIT_SABM	4
94 #define WAIT_UA		5
95 #define DISC_SENT	6
96 #define DISCONNECTED	7
97 #define MAXSTATE	8
98 
99 /* The following constants are used in a switch statement to process
100    frames read from the communications line. */
101 
102 #define SABM     0 * MAXSTATE
103 #define DM       1 * MAXSTATE
104 #define DISC     2 * MAXSTATE
105 #define UA       3 * MAXSTATE
106 #define FRMR     4 * MAXSTATE
107 #define RR       5 * MAXSTATE
108 #define RNR      6 * MAXSTATE
109 #define REJ      7 * MAXSTATE
110 #define IFRAME   8 * MAXSTATE
111 #define ILLEGAL  9 * MAXSTATE
112 
113 #define T1	(3 * PR_SLOWHZ)		/*  IFRAME TIMEOUT - 3 seconds */
114 #define T3	(T1 / 2)		/*  RR generate timeout - 1.5 seconds */
115 #define N2	10
116 #define MODULUS 8
117 #define MAX_WINDOW_SIZE 7
118 
119 #define Z  0
120 #define Y  1
121 #define X  2
122 #define W  3
123 #define A  4
124 
125 #define TX 0
126 #define RX 1
127 
128 bool	range_check ();
129 bool	valid_nr ();
130 struct	mbuf *hd_remove ();
131