cnmagic.c revision 1.1.2.3 1 1.1.2.3 bouyer /* $NetBSD: cnmagic.c,v 1.1.2.3 2001/01/05 17:36:36 bouyer Exp $ */
2 1.1.2.2 bouyer
3 1.1.2.2 bouyer /*
4 1.1.2.2 bouyer * Copyright (c) 2000 Eduardo Horvath
5 1.1.2.2 bouyer * All rights reserved.
6 1.1.2.2 bouyer *
7 1.1.2.2 bouyer * Redistribution and use in source and binary forms, with or without
8 1.1.2.2 bouyer * modification, are permitted provided that the following conditions
9 1.1.2.2 bouyer * are met:
10 1.1.2.2 bouyer * 1. Redistributions of source code must retain the above copyright
11 1.1.2.2 bouyer * notice, this list of conditions and the following disclaimer.
12 1.1.2.2 bouyer * 2. Redistributions in binary form must reproduce the above copyright
13 1.1.2.2 bouyer * notice, this list of conditions and the following disclaimer in the
14 1.1.2.2 bouyer * documentation and/or other materials provided with the distribution.
15 1.1.2.2 bouyer * 3. All advertising materials mentioning features or use of this software
16 1.1.2.2 bouyer * must display the following acknowledgement:
17 1.1.2.2 bouyer * This product includes software developed by Eduardo Horvath.
18 1.1.2.2 bouyer * 4. The name of the author may not be used to endorse or promote products
19 1.1.2.2 bouyer * derived from this software without specific prior written permission
20 1.1.2.2 bouyer *
21 1.1.2.2 bouyer * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 1.1.2.2 bouyer * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 1.1.2.2 bouyer * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 1.1.2.2 bouyer * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 1.1.2.2 bouyer * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 1.1.2.2 bouyer * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 1.1.2.2 bouyer * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 1.1.2.2 bouyer * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 1.1.2.2 bouyer * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30 1.1.2.2 bouyer * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 1.1.2.2 bouyer */
32 1.1.2.2 bouyer
33 1.1.2.2 bouyer #include <sys/param.h>
34 1.1.2.2 bouyer #include <sys/systm.h>
35 1.1.2.3 bouyer #include <sys/kernel.h>
36 1.1.2.2 bouyer
37 1.1.2.2 bouyer #define ENCODE_STATE(c, n) (short)(((c)&0x1ff)|(((n)&0x7f)<<9))
38 1.1.2.2 bouyer
39 1.1.2.2 bouyer static unsigned short cn_magic[CNS_LEN];
40 1.1.2.2 bouyer
41 1.1.2.2 bouyer /*
42 1.1.2.2 bouyer * Initialize a cnm_state_t.
43 1.1.2.2 bouyer */
44 1.1.2.2 bouyer void
45 1.1.2.2 bouyer cn_init_magic(cnm_state_t *cnm) {
46 1.1.2.2 bouyer cnm->cnm_state = 0;
47 1.1.2.2 bouyer cnm->cnm_magic = cn_magic;
48 1.1.2.2 bouyer }
49 1.1.2.2 bouyer
50 1.1.2.2 bouyer /*
51 1.1.2.2 bouyer * Destroy a cnm_state_t.
52 1.1.2.2 bouyer */
53 1.1.2.2 bouyer void
54 1.1.2.2 bouyer cn_destroy_magic(cnm_state_t *cnm) {
55 1.1.2.2 bouyer cnm->cnm_state = 0;
56 1.1.2.2 bouyer cnm->cnm_magic = NULL;
57 1.1.2.2 bouyer }
58 1.1.2.2 bouyer
59 1.1.2.2 bouyer /*
60 1.1.2.2 bouyer * Translate a magic string to a state
61 1.1.2.2 bouyer * machine table.
62 1.1.2.2 bouyer */
63 1.1.2.2 bouyer int
64 1.1.2.2 bouyer cn_set_magic(char *magic)
65 1.1.2.2 bouyer {
66 1.1.2.2 bouyer unsigned int i, c, n;
67 1.1.2.2 bouyer unsigned short m[CNS_LEN];
68 1.1.2.2 bouyer
69 1.1.2.2 bouyer for (i=0; i<CNS_LEN; i++) {
70 1.1.2.2 bouyer c = (*magic++)&0xff;
71 1.1.2.2 bouyer n = *magic ? i+1 : CNS_TERM;
72 1.1.2.2 bouyer switch (c) {
73 1.1.2.2 bouyer case 0:
74 1.1.2.2 bouyer /* End of string */
75 1.1.2.2 bouyer if (i == 0) {
76 1.1.2.2 bouyer /* empty string? */
77 1.1.2.2 bouyer cn_magic[0] = 0;
78 1.1.2.2 bouyer #ifdef DEBUG
79 1.1.2.2 bouyer printf("cn_set_magic(): empty!\n");
80 1.1.2.2 bouyer #endif
81 1.1.2.2 bouyer return (0);
82 1.1.2.2 bouyer }
83 1.1.2.2 bouyer do {
84 1.1.2.2 bouyer cn_magic[i] = m[i];
85 1.1.2.2 bouyer } while (i--);
86 1.1.2.2 bouyer return(0);
87 1.1.2.2 bouyer case 0x27:
88 1.1.2.2 bouyer /* Escape sequence */
89 1.1.2.2 bouyer c = (*magic++)&0xff;
90 1.1.2.2 bouyer n = *magic ? i+1 : CNS_TERM;
91 1.1.2.2 bouyer switch (c) {
92 1.1.2.2 bouyer case 0x27:
93 1.1.2.2 bouyer break;
94 1.1.2.2 bouyer case 0x01:
95 1.1.2.2 bouyer /* BREAK */
96 1.1.2.2 bouyer c = CNC_BREAK;
97 1.1.2.2 bouyer break;
98 1.1.2.2 bouyer case 0x02:
99 1.1.2.2 bouyer /* NUL */
100 1.1.2.2 bouyer c = 0;
101 1.1.2.2 bouyer break;
102 1.1.2.2 bouyer }
103 1.1.2.2 bouyer /* FALLTHROUGH */
104 1.1.2.2 bouyer default:
105 1.1.2.2 bouyer /* Transition to the next state. */
106 1.1.2.2 bouyer #ifdef DEBUG
107 1.1.2.3 bouyer if (!cold)
108 1.1.2.3 bouyer printf("mag %d %x:%x\n", i, c, n);
109 1.1.2.2 bouyer #endif
110 1.1.2.2 bouyer m[i] = ENCODE_STATE(c, n);
111 1.1.2.2 bouyer break;
112 1.1.2.2 bouyer }
113 1.1.2.2 bouyer }
114 1.1.2.2 bouyer return (EINVAL);
115 1.1.2.2 bouyer }
116 1.1.2.2 bouyer
117 1.1.2.2 bouyer /*
118 1.1.2.2 bouyer * Translatea state machine table back to
119 1.1.2.2 bouyer * a magic string.
120 1.1.2.2 bouyer */
121 1.1.2.2 bouyer int
122 1.1.2.2 bouyer cn_get_magic(char *magic, int maglen) {
123 1.1.2.2 bouyer unsigned int i, c;
124 1.1.2.2 bouyer
125 1.1.2.2 bouyer for (i=0; i<CNS_LEN; i++) {
126 1.1.2.2 bouyer c = cn_magic[i];
127 1.1.2.2 bouyer /* Translate a character */
128 1.1.2.2 bouyer switch (CNS_MAGIC_VAL(c)) {
129 1.1.2.2 bouyer case CNC_BREAK:
130 1.1.2.2 bouyer *magic++ = 0x27;
131 1.1.2.2 bouyer *magic++ = 0x01;
132 1.1.2.2 bouyer break;
133 1.1.2.2 bouyer case 0:
134 1.1.2.2 bouyer *magic++ = 0x27;
135 1.1.2.2 bouyer *magic++ = 0x02;
136 1.1.2.2 bouyer break;
137 1.1.2.2 bouyer case 0x27:
138 1.1.2.2 bouyer *magic++ = 0x27;
139 1.1.2.2 bouyer *magic++ = 0x27;
140 1.1.2.2 bouyer break;
141 1.1.2.2 bouyer default:
142 1.1.2.2 bouyer *magic++ = (c&0x0ff);
143 1.1.2.2 bouyer break;
144 1.1.2.2 bouyer }
145 1.1.2.2 bouyer /* Now go to the next state */
146 1.1.2.2 bouyer i = CNS_MAGIC_NEXT(c);
147 1.1.2.2 bouyer if (i == CNS_TERM || i == 0) {
148 1.1.2.2 bouyer /* Either termination state or empty machine */
149 1.1.2.2 bouyer *magic++ = 0;
150 1.1.2.2 bouyer return (0);
151 1.1.2.2 bouyer }
152 1.1.2.2 bouyer }
153 1.1.2.2 bouyer return (EINVAL);
154 1.1.2.2 bouyer }
155 1.1.2.2 bouyer
156