cnmagic.c revision 1.1.2.2
1 1.1.2.2 bouyer /* $NetBSD: cnmagic.c,v 1.1.2.2 2000/11/22 16:05:14 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 1.1.2.2 bouyer 36 1.1.2.2 bouyer #define ENCODE_STATE(c, n) (short)(((c)&0x1ff)|(((n)&0x7f)<<9)) 37 1.1.2.2 bouyer 38 1.1.2.2 bouyer static unsigned short cn_magic[CNS_LEN]; 39 1.1.2.2 bouyer 40 1.1.2.2 bouyer /* 41 1.1.2.2 bouyer * Initialize a cnm_state_t. 42 1.1.2.2 bouyer */ 43 1.1.2.2 bouyer void 44 1.1.2.2 bouyer cn_init_magic(cnm_state_t *cnm) { 45 1.1.2.2 bouyer cnm->cnm_state = 0; 46 1.1.2.2 bouyer cnm->cnm_magic = cn_magic; 47 1.1.2.2 bouyer } 48 1.1.2.2 bouyer 49 1.1.2.2 bouyer /* 50 1.1.2.2 bouyer * Destroy a cnm_state_t. 51 1.1.2.2 bouyer */ 52 1.1.2.2 bouyer void 53 1.1.2.2 bouyer cn_destroy_magic(cnm_state_t *cnm) { 54 1.1.2.2 bouyer cnm->cnm_state = 0; 55 1.1.2.2 bouyer cnm->cnm_magic = NULL; 56 1.1.2.2 bouyer } 57 1.1.2.2 bouyer 58 1.1.2.2 bouyer /* 59 1.1.2.2 bouyer * Translate a magic string to a state 60 1.1.2.2 bouyer * machine table. 61 1.1.2.2 bouyer */ 62 1.1.2.2 bouyer int 63 1.1.2.2 bouyer cn_set_magic(char *magic) 64 1.1.2.2 bouyer { 65 1.1.2.2 bouyer unsigned int i, c, n; 66 1.1.2.2 bouyer unsigned short m[CNS_LEN]; 67 1.1.2.2 bouyer 68 1.1.2.2 bouyer for (i=0; i<CNS_LEN; i++) { 69 1.1.2.2 bouyer c = (*magic++)&0xff; 70 1.1.2.2 bouyer n = *magic ? i+1 : CNS_TERM; 71 1.1.2.2 bouyer switch (c) { 72 1.1.2.2 bouyer case 0: 73 1.1.2.2 bouyer /* End of string */ 74 1.1.2.2 bouyer if (i == 0) { 75 1.1.2.2 bouyer /* empty string? */ 76 1.1.2.2 bouyer cn_magic[0] = 0; 77 1.1.2.2 bouyer #ifdef DEBUG 78 1.1.2.2 bouyer printf("cn_set_magic(): empty!\n"); 79 1.1.2.2 bouyer #endif 80 1.1.2.2 bouyer return (0); 81 1.1.2.2 bouyer } 82 1.1.2.2 bouyer do { 83 1.1.2.2 bouyer cn_magic[i] = m[i]; 84 1.1.2.2 bouyer } while (i--); 85 1.1.2.2 bouyer return(0); 86 1.1.2.2 bouyer case 0x27: 87 1.1.2.2 bouyer /* Escape sequence */ 88 1.1.2.2 bouyer c = (*magic++)&0xff; 89 1.1.2.2 bouyer n = *magic ? i+1 : CNS_TERM; 90 1.1.2.2 bouyer switch (c) { 91 1.1.2.2 bouyer case 0x27: 92 1.1.2.2 bouyer break; 93 1.1.2.2 bouyer case 0x01: 94 1.1.2.2 bouyer /* BREAK */ 95 1.1.2.2 bouyer c = CNC_BREAK; 96 1.1.2.2 bouyer break; 97 1.1.2.2 bouyer case 0x02: 98 1.1.2.2 bouyer /* NUL */ 99 1.1.2.2 bouyer c = 0; 100 1.1.2.2 bouyer break; 101 1.1.2.2 bouyer } 102 1.1.2.2 bouyer /* FALLTHROUGH */ 103 1.1.2.2 bouyer default: 104 1.1.2.2 bouyer /* Transition to the next state. */ 105 1.1.2.2 bouyer #ifdef DEBUG 106 1.1.2.2 bouyer printf("mag %d %x:%x\n", i, c, n); 107 1.1.2.2 bouyer #endif 108 1.1.2.2 bouyer m[i] = ENCODE_STATE(c, n); 109 1.1.2.2 bouyer break; 110 1.1.2.2 bouyer } 111 1.1.2.2 bouyer } 112 1.1.2.2 bouyer return (EINVAL); 113 1.1.2.2 bouyer } 114 1.1.2.2 bouyer 115 1.1.2.2 bouyer /* 116 1.1.2.2 bouyer * Translatea state machine table back to 117 1.1.2.2 bouyer * a magic string. 118 1.1.2.2 bouyer */ 119 1.1.2.2 bouyer int 120 1.1.2.2 bouyer cn_get_magic(char *magic, int maglen) { 121 1.1.2.2 bouyer unsigned int i, c; 122 1.1.2.2 bouyer 123 1.1.2.2 bouyer for (i=0; i<CNS_LEN; i++) { 124 1.1.2.2 bouyer c = cn_magic[i]; 125 1.1.2.2 bouyer /* Translate a character */ 126 1.1.2.2 bouyer switch (CNS_MAGIC_VAL(c)) { 127 1.1.2.2 bouyer case CNC_BREAK: 128 1.1.2.2 bouyer *magic++ = 0x27; 129 1.1.2.2 bouyer *magic++ = 0x01; 130 1.1.2.2 bouyer break; 131 1.1.2.2 bouyer case 0: 132 1.1.2.2 bouyer *magic++ = 0x27; 133 1.1.2.2 bouyer *magic++ = 0x02; 134 1.1.2.2 bouyer break; 135 1.1.2.2 bouyer case 0x27: 136 1.1.2.2 bouyer *magic++ = 0x27; 137 1.1.2.2 bouyer *magic++ = 0x27; 138 1.1.2.2 bouyer break; 139 1.1.2.2 bouyer default: 140 1.1.2.2 bouyer *magic++ = (c&0x0ff); 141 1.1.2.2 bouyer break; 142 1.1.2.2 bouyer } 143 1.1.2.2 bouyer /* Now go to the next state */ 144 1.1.2.2 bouyer i = CNS_MAGIC_NEXT(c); 145 1.1.2.2 bouyer if (i == CNS_TERM || i == 0) { 146 1.1.2.2 bouyer /* Either termination state or empty machine */ 147 1.1.2.2 bouyer *magic++ = 0; 148 1.1.2.2 bouyer return (0); 149 1.1.2.2 bouyer } 150 1.1.2.2 bouyer } 151 1.1.2.2 bouyer return (EINVAL); 152 1.1.2.2 bouyer } 153 1.1.2.2 bouyer 154
Indexes created Wed Oct 22 13:09:56 GMT 2025