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sir.c revision 1.5.34.1
      1  1.5.34.1      yamt /*	$NetBSD: sir.c,v 1.5.34.1 2014/05/22 11:40:22 yamt Exp $	*/
      2       1.1  augustss 
      3       1.1  augustss /*
      4       1.1  augustss  * Copyright (c) 2001 The NetBSD Foundation, Inc.
      5       1.1  augustss  * All rights reserved.
      6       1.1  augustss  *
      7       1.1  augustss  * This code is derived from software contributed to The NetBSD Foundation
      8       1.1  augustss  * by Lennart Augustsson (lennart (at) augustsson.net) and Tommy Bohlin
      9       1.1  augustss  * (tommy (at) gatespace.com).
     10       1.1  augustss  *
     11       1.1  augustss  * Redistribution and use in source and binary forms, with or without
     12       1.1  augustss  * modification, are permitted provided that the following conditions
     13       1.1  augustss  * are met:
     14       1.1  augustss  * 1. Redistributions of source code must retain the above copyright
     15       1.1  augustss  *    notice, this list of conditions and the following disclaimer.
     16       1.1  augustss  * 2. Redistributions in binary form must reproduce the above copyright
     17       1.1  augustss  *    notice, this list of conditions and the following disclaimer in the
     18       1.1  augustss  *    documentation and/or other materials provided with the distribution.
     19       1.1  augustss  *
     20       1.1  augustss  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     21       1.1  augustss  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     22       1.1  augustss  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     23       1.1  augustss  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     24       1.1  augustss  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     25       1.1  augustss  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     26       1.1  augustss  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     27       1.1  augustss  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     28       1.1  augustss  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     29       1.1  augustss  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     30       1.1  augustss  * POSSIBILITY OF SUCH DAMAGE.
     31       1.1  augustss  */
     32       1.1  augustss 
     33       1.1  augustss /*
     34       1.1  augustss  * Framing originally written by Tommy Bohlin.
     35       1.1  augustss  */
     36       1.3     lukem 
     37       1.3     lukem #include <sys/cdefs.h>
     38  1.5.34.1      yamt __KERNEL_RCSID(0, "$NetBSD: sir.c,v 1.5.34.1 2014/05/22 11:40:22 yamt Exp $");
     39       1.1  augustss 
     40       1.1  augustss #include <sys/param.h>
     41       1.1  augustss #include <sys/conf.h>
     42       1.1  augustss #include <sys/systm.h>
     43       1.1  augustss 
     44       1.1  augustss #include <dev/ir/sir.h>
     45       1.1  augustss 
     46       1.1  augustss /*
     47       1.1  augustss  * CRC computation table
     48       1.1  augustss  */
     49  1.5.34.1      yamt const uint16_t irda_fcstab[] = {
     50       1.1  augustss 	0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
     51       1.1  augustss 	0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
     52       1.1  augustss 	0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
     53       1.1  augustss 	0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
     54       1.1  augustss 	0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
     55       1.1  augustss 	0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
     56       1.1  augustss 	0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
     57       1.1  augustss 	0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
     58       1.1  augustss 	0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
     59       1.1  augustss 	0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
     60       1.1  augustss 	0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
     61       1.1  augustss 	0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
     62       1.1  augustss 	0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
     63       1.1  augustss 	0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
     64       1.1  augustss 	0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
     65       1.1  augustss 	0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
     66       1.1  augustss 	0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
     67       1.1  augustss 	0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
     68       1.1  augustss 	0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
     69       1.1  augustss 	0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
     70       1.1  augustss 	0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
     71       1.1  augustss 	0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
     72       1.1  augustss 	0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
     73       1.1  augustss 	0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
     74       1.1  augustss 	0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
     75       1.1  augustss 	0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
     76       1.1  augustss 	0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
     77       1.1  augustss 	0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
     78       1.1  augustss 	0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
     79       1.1  augustss 	0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
     80       1.1  augustss 	0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
     81       1.1  augustss 	0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
     82       1.1  augustss };
     83       1.1  augustss 
     84       1.1  augustss #define MAX_IRDA_FRAME 5000	/* XXX what is it? */
     85       1.1  augustss 
     86       1.1  augustss #define PUTC(c) if (p < end) *p++ = (c)
     87       1.1  augustss #define PUTESC(c) \
     88       1.1  augustss 	if (c == SIR_BOF || c == SIR_EOF || c == SIR_CE) { \
     89       1.1  augustss 		PUTC(SIR_CE); \
     90       1.1  augustss 		PUTC(SIR_ESC_BIT^c); \
     91       1.1  augustss 	} else { \
     92       1.1  augustss 		PUTC(c); \
     93       1.1  augustss 	}
     94       1.1  augustss 
     95       1.2  augustss #define CHUNK 512
     96       1.2  augustss 
     97       1.1  augustss int
     98  1.5.34.1      yamt irda_sir_frame(uint8_t *obuf, u_int maxlen, struct uio *uio, u_int ebofs)
     99       1.1  augustss {
    100  1.5.34.1      yamt 	uint8_t ibuf[CHUNK];
    101  1.5.34.1      yamt 	uint8_t *p, *end, *cp;
    102       1.1  augustss 	size_t n;
    103       1.1  augustss 	int error;
    104       1.1  augustss 	int i;
    105       1.1  augustss 	int c;
    106  1.5.34.1      yamt 	uint16_t ofcs;
    107       1.1  augustss 
    108       1.2  augustss 	p = obuf;
    109       1.2  augustss 	end = p + maxlen;
    110       1.1  augustss 
    111       1.1  augustss 	for (i = 0; i < ebofs; i++)
    112       1.1  augustss 		PUTC(SIR_EXTRA_BOF);
    113       1.1  augustss 	PUTC(SIR_BOF);
    114       1.1  augustss 
    115       1.1  augustss 	ofcs = INITFCS;
    116       1.2  augustss 	while (uio->uio_resid > 0) {
    117       1.2  augustss 		n = uio->uio_resid;
    118       1.2  augustss 		if (n > CHUNK)
    119       1.2  augustss 			n = CHUNK;
    120       1.2  augustss 		error = uiomove(ibuf, n, uio);
    121       1.2  augustss 		if (error)
    122       1.2  augustss 			return (-error);
    123       1.2  augustss 
    124       1.2  augustss 		cp = ibuf;
    125       1.2  augustss 		while (n-- > 0) {
    126       1.2  augustss 			c = *cp++;
    127       1.2  augustss 			ofcs = updateFCS(ofcs, c);
    128       1.2  augustss 			PUTESC(c);
    129       1.2  augustss 		}
    130       1.1  augustss 	}
    131       1.1  augustss 
    132       1.1  augustss 	ofcs = ~ofcs;
    133       1.1  augustss 	c = ofcs & 0xff;
    134       1.1  augustss 	PUTESC(c);
    135       1.1  augustss 	c = (ofcs >> 8) & 0xff;
    136       1.1  augustss 	PUTESC(c);
    137       1.1  augustss 	PUTC(SIR_EOF);
    138       1.1  augustss 
    139       1.1  augustss 	if (p < end)
    140       1.1  augustss 		return (p - obuf);
    141       1.1  augustss 	else
    142       1.1  augustss 		return (-EINVAL);
    143       1.1  augustss }
    144  1.5.34.1      yamt 
    145  1.5.34.1      yamt void
    146  1.5.34.1      yamt deframe_init(struct framestate *fstate, uint8_t *buf, size_t buflen)
    147  1.5.34.1      yamt {
    148  1.5.34.1      yamt 
    149  1.5.34.1      yamt 	fstate->buffer = buf;
    150  1.5.34.1      yamt 	fstate->buflen = buflen;
    151  1.5.34.1      yamt 
    152  1.5.34.1      yamt 	deframe_clear(fstate);
    153  1.5.34.1      yamt }
    154  1.5.34.1      yamt 
    155  1.5.34.1      yamt void
    156  1.5.34.1      yamt deframe_clear(struct framestate *fstate)
    157  1.5.34.1      yamt {
    158  1.5.34.1      yamt 
    159  1.5.34.1      yamt 	fstate->bufindex = 0;
    160  1.5.34.1      yamt 	fstate->fsmstate = FSTATE_END_OF_FRAME;
    161  1.5.34.1      yamt 	fstate->escaped = 0;
    162  1.5.34.1      yamt }
    163  1.5.34.1      yamt 
    164  1.5.34.1      yamt enum frameresult
    165  1.5.34.1      yamt deframe_process(struct framestate *fstate, uint8_t const **bptr, size_t *blen)
    166  1.5.34.1      yamt {
    167  1.5.34.1      yamt 	uint8_t const *cptr;
    168  1.5.34.1      yamt 	size_t ibuflen, obufindex, obuflen;
    169  1.5.34.1      yamt 	enum framefsmstate fsmstate;
    170  1.5.34.1      yamt 	enum frameresult result;
    171  1.5.34.1      yamt 
    172  1.5.34.1      yamt 	cptr = *bptr;
    173  1.5.34.1      yamt 	fsmstate = fstate->fsmstate;
    174  1.5.34.1      yamt 	obufindex = fstate->bufindex;
    175  1.5.34.1      yamt 	obuflen = fstate->buflen;
    176  1.5.34.1      yamt 	ibuflen = *blen;
    177  1.5.34.1      yamt 
    178  1.5.34.1      yamt 	while (ibuflen-- > 0) {
    179  1.5.34.1      yamt 		uint8_t chr;
    180  1.5.34.1      yamt 
    181  1.5.34.1      yamt 		chr = *cptr++;
    182  1.5.34.1      yamt 
    183  1.5.34.1      yamt 		if (fstate->escaped) {
    184  1.5.34.1      yamt 			fstate->escaped = 0;
    185  1.5.34.1      yamt 			chr ^= SIR_ESC_BIT;
    186  1.5.34.1      yamt 		} else if (chr == SIR_CE) {
    187  1.5.34.1      yamt 			fstate->escaped = 1;
    188  1.5.34.1      yamt 			continue;
    189  1.5.34.1      yamt 		}
    190  1.5.34.1      yamt 
    191  1.5.34.1      yamt 		switch (fsmstate) {
    192  1.5.34.1      yamt 		case FSTATE_IN_DATA:
    193  1.5.34.1      yamt 			if (chr == SIR_EOF) {
    194  1.5.34.1      yamt 				fsmstate = FSTATE_IN_END;
    195  1.5.34.1      yamt 				fstate->state_index = 1;
    196  1.5.34.1      yamt 				goto state_in_end;
    197  1.5.34.1      yamt 			}
    198  1.5.34.1      yamt 			if (obufindex >= obuflen) {
    199  1.5.34.1      yamt 				result = FR_BUFFEROVERRUN;
    200  1.5.34.1      yamt 				fsmstate = FSTATE_END_OF_FRAME;
    201  1.5.34.1      yamt 				goto complete;
    202  1.5.34.1      yamt 			}
    203  1.5.34.1      yamt 			fstate->buffer[obufindex++] = chr;
    204  1.5.34.1      yamt 			break;
    205  1.5.34.1      yamt 
    206  1.5.34.1      yamt 		state_in_end:
    207  1.5.34.1      yamt 			/* FALLTHROUGH */
    208  1.5.34.1      yamt 
    209  1.5.34.1      yamt 		case FSTATE_IN_END:
    210  1.5.34.1      yamt 			if (--fstate->state_index == 0) {
    211  1.5.34.1      yamt 				uint32_t crc;
    212  1.5.34.1      yamt 				const size_t fcslen = 2;
    213  1.5.34.1      yamt 
    214  1.5.34.1      yamt 				fsmstate = FSTATE_END_OF_FRAME;
    215  1.5.34.1      yamt 
    216  1.5.34.1      yamt 				if (obufindex < fcslen) {
    217  1.5.34.1      yamt 					result = FR_FRAMEMALFORMED;
    218  1.5.34.1      yamt 					goto complete;
    219  1.5.34.1      yamt 				}
    220  1.5.34.1      yamt 
    221  1.5.34.1      yamt 				crc = crc_ccitt_16(INITFCS, fstate->buffer,
    222  1.5.34.1      yamt 				    obufindex);
    223  1.5.34.1      yamt 
    224  1.5.34.1      yamt 				/* Remove check bytes from buffer length */
    225  1.5.34.1      yamt 				obufindex -= fcslen;
    226  1.5.34.1      yamt 
    227  1.5.34.1      yamt 				if (crc == GOODFCS)
    228  1.5.34.1      yamt 					result = FR_FRAMEOK;
    229  1.5.34.1      yamt 				else
    230  1.5.34.1      yamt 					result = FR_FRAMEBADFCS;
    231  1.5.34.1      yamt 
    232  1.5.34.1      yamt 				goto complete;
    233  1.5.34.1      yamt 			}
    234  1.5.34.1      yamt 			break;
    235  1.5.34.1      yamt 
    236  1.5.34.1      yamt 		case FSTATE_END_OF_FRAME:
    237  1.5.34.1      yamt 			if (chr != SIR_BOF)
    238  1.5.34.1      yamt 				break;
    239  1.5.34.1      yamt 
    240  1.5.34.1      yamt 			fsmstate = FSTATE_START_OF_FRAME;
    241  1.5.34.1      yamt 			fstate->state_index = 1;
    242  1.5.34.1      yamt 			/* FALLTHROUGH */
    243  1.5.34.1      yamt 		case FSTATE_START_OF_FRAME:
    244  1.5.34.1      yamt 			if (--fstate->state_index == 0) {
    245  1.5.34.1      yamt 				fsmstate = FSTATE_IN_DATA;
    246  1.5.34.1      yamt 				obufindex = 0;
    247  1.5.34.1      yamt 			}
    248  1.5.34.1      yamt 			break;
    249  1.5.34.1      yamt 		}
    250  1.5.34.1      yamt 	}
    251  1.5.34.1      yamt 
    252  1.5.34.1      yamt 	result = (fsmstate == FSTATE_END_OF_FRAME) ? FR_IDLE : FR_INPROGRESS;
    253  1.5.34.1      yamt 
    254  1.5.34.1      yamt  complete:
    255  1.5.34.1      yamt 	fstate->bufindex = obufindex;
    256  1.5.34.1      yamt 	fstate->fsmstate = fsmstate;
    257  1.5.34.1      yamt 	*blen = ibuflen;
    258  1.5.34.1      yamt 
    259  1.5.34.1      yamt 	return result;
    260  1.5.34.1      yamt }
    261  1.5.34.1      yamt 
    262  1.5.34.1      yamt uint32_t
    263  1.5.34.1      yamt crc_ccitt_16(uint32_t crcinit, uint8_t const *buf, size_t blen)
    264  1.5.34.1      yamt {
    265  1.5.34.1      yamt 
    266  1.5.34.1      yamt 	while (blen-- > 0) {
    267  1.5.34.1      yamt 		uint8_t chr;
    268  1.5.34.1      yamt 		chr = *buf++;
    269  1.5.34.1      yamt 		crcinit = updateFCS(crcinit, chr);
    270  1.5.34.1      yamt 	}
    271  1.5.34.1      yamt 	return crcinit;
    272  1.5.34.1      yamt }
    273