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 | |