1 /* $NetBSD: sir.c,v 1.6 2013/05/27 16:23:20 kiyohara Exp $ */ 2 3 /* 4 * Copyright (c) 2001 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Lennart Augustsson (lennart (at) augustsson.net) and Tommy Bohlin 9 * (tommy (at) gatespace.com). 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 /* 34 * Framing originally written by Tommy Bohlin. 35 */ 36 37 #include <sys/cdefs.h> 38 __KERNEL_RCSID(0, "$NetBSD: sir.c,v 1.6 2013/05/27 16:23:20 kiyohara Exp $"); 39 40 #include <sys/param.h> 41 #include <sys/conf.h> 42 #include <sys/systm.h> 43 44 #include <dev/ir/sir.h> 45 46 /* 47 * CRC computation table 48 */ 49 const uint16_t irda_fcstab[] = { 50 0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf, 51 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7, 52 0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e, 53 0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876, 54 0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd, 55 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5, 56 0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c, 57 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974, 58 0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb, 59 0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3, 60 0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a, 61 0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72, 62 0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9, 63 0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1, 64 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738, 65 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70, 66 0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7, 67 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff, 68 0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036, 69 0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e, 70 0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5, 71 0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd, 72 0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134, 73 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c, 74 0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3, 75 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb, 76 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232, 77 0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a, 78 0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1, 79 0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9, 80 0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330, 81 0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78 82 }; 83 84 #define MAX_IRDA_FRAME 5000 /* XXX what is it? */ 85 86 #define PUTC(c) if (p < end) *p++ = (c) 87 #define PUTESC(c) \ 88 if (c == SIR_BOF || c == SIR_EOF || c == SIR_CE) { \ 89 PUTC(SIR_CE); \ 90 PUTC(SIR_ESC_BIT^c); \ 91 } else { \ 92 PUTC(c); \ 93 } 94 95 #define CHUNK 512 96 97 int 98 irda_sir_frame(uint8_t *obuf, u_int maxlen, struct uio *uio, u_int ebofs) 99 { 100 uint8_t ibuf[CHUNK]; 101 uint8_t *p, *end, *cp; 102 size_t n; 103 int error; 104 int i; 105 int c; 106 uint16_t ofcs; 107 108 p = obuf; 109 end = p + maxlen; 110 111 for (i = 0; i < ebofs; i++) 112 PUTC(SIR_EXTRA_BOF); 113 PUTC(SIR_BOF); 114 115 ofcs = INITFCS; 116 while (uio->uio_resid > 0) { 117 n = uio->uio_resid; 118 if (n > CHUNK) 119 n = CHUNK; 120 error = uiomove(ibuf, n, uio); 121 if (error) 122 return (-error); 123 124 cp = ibuf; 125 while (n-- > 0) { 126 c = *cp++; 127 ofcs = updateFCS(ofcs, c); 128 PUTESC(c); 129 } 130 } 131 132 ofcs = ~ofcs; 133 c = ofcs & 0xff; 134 PUTESC(c); 135 c = (ofcs >> 8) & 0xff; 136 PUTESC(c); 137 PUTC(SIR_EOF); 138 139 if (p < end) 140 return (p - obuf); 141 else 142 return (-EINVAL); 143 } 144 145 void 146 deframe_init(struct framestate *fstate, uint8_t *buf, size_t buflen) 147 { 148 149 fstate->buffer = buf; 150 fstate->buflen = buflen; 151 152 deframe_clear(fstate); 153 } 154 155 void 156 deframe_clear(struct framestate *fstate) 157 { 158 159 fstate->bufindex = 0; 160 fstate->fsmstate = FSTATE_END_OF_FRAME; 161 fstate->escaped = 0; 162 } 163 164 enum frameresult 165 deframe_process(struct framestate *fstate, uint8_t const **bptr, size_t *blen) 166 { 167 uint8_t const *cptr; 168 size_t ibuflen, obufindex, obuflen; 169 enum framefsmstate fsmstate; 170 enum frameresult result; 171 172 cptr = *bptr; 173 fsmstate = fstate->fsmstate; 174 obufindex = fstate->bufindex; 175 obuflen = fstate->buflen; 176 ibuflen = *blen; 177 178 while (ibuflen-- > 0) { 179 uint8_t chr; 180 181 chr = *cptr++; 182 183 if (fstate->escaped) { 184 fstate->escaped = 0; 185 chr ^= SIR_ESC_BIT; 186 } else if (chr == SIR_CE) { 187 fstate->escaped = 1; 188 continue; 189 } 190 191 switch (fsmstate) { 192 case FSTATE_IN_DATA: 193 if (chr == SIR_EOF) { 194 fsmstate = FSTATE_IN_END; 195 fstate->state_index = 1; 196 goto state_in_end; 197 } 198 if (obufindex >= obuflen) { 199 result = FR_BUFFEROVERRUN; 200 fsmstate = FSTATE_END_OF_FRAME; 201 goto complete; 202 } 203 fstate->buffer[obufindex++] = chr; 204 break; 205 206 state_in_end: 207 /* FALLTHROUGH */ 208 209 case FSTATE_IN_END: 210 if (--fstate->state_index == 0) { 211 uint32_t crc; 212 const size_t fcslen = 2; 213 214 fsmstate = FSTATE_END_OF_FRAME; 215 216 if (obufindex < fcslen) { 217 result = FR_FRAMEMALFORMED; 218 goto complete; 219 } 220 221 crc = crc_ccitt_16(INITFCS, fstate->buffer, 222 obufindex); 223 224 /* Remove check bytes from buffer length */ 225 obufindex -= fcslen; 226 227 if (crc == GOODFCS) 228 result = FR_FRAMEOK; 229 else 230 result = FR_FRAMEBADFCS; 231 232 goto complete; 233 } 234 break; 235 236 case FSTATE_END_OF_FRAME: 237 if (chr != SIR_BOF) 238 break; 239 240 fsmstate = FSTATE_START_OF_FRAME; 241 fstate->state_index = 1; 242 /* FALLTHROUGH */ 243 case FSTATE_START_OF_FRAME: 244 if (--fstate->state_index == 0) { 245 fsmstate = FSTATE_IN_DATA; 246 obufindex = 0; 247 } 248 break; 249 } 250 } 251 252 result = (fsmstate == FSTATE_END_OF_FRAME) ? FR_IDLE : FR_INPROGRESS; 253 254 complete: 255 fstate->bufindex = obufindex; 256 fstate->fsmstate = fsmstate; 257 *blen = ibuflen; 258 259 return result; 260 } 261 262 uint32_t 263 crc_ccitt_16(uint32_t crcinit, uint8_t const *buf, size_t blen) 264 { 265 266 while (blen-- > 0) { 267 uint8_t chr; 268 chr = *buf++; 269 crcinit = updateFCS(crcinit, chr); 270 } 271 return crcinit; 272 } 273
Indexes created Mon Sep 22 05:09:51 GMT 2025