| 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@augustsson.net) and Tommy Bohlin |
| 9 | * (tommy@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 | |