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
irda_sir_frame(uint8_t * obuf,u_int maxlen,struct uio * uio,u_int ebofs)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
deframe_init(struct framestate * fstate,uint8_t * buf,size_t buflen)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
deframe_clear(struct framestate * fstate)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
deframe_process(struct framestate * fstate,uint8_t const ** bptr,size_t * blen)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
crc_ccitt_16(uint32_t crcinit,uint8_t const * buf,size_t blen)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