|
5
|
1 /*
|
|
|
2 * SpanDSP - a series of DSP components for telephony
|
|
|
3 *
|
|
|
4 * hdlc.c
|
|
|
5 *
|
|
|
6 * Written by Steve Underwood <steveu@coppice.org>
|
|
|
7 *
|
|
|
8 * Copyright (C) 2003 Steve Underwood
|
|
|
9 *
|
|
|
10 * All rights reserved.
|
|
|
11 *
|
|
|
12 * This program is free software; you can redistribute it and/or modify
|
|
|
13 * it under the terms of the GNU General Public License version 2, as
|
|
|
14 * published by the Free Software Foundation.
|
|
|
15 *
|
|
|
16 * This program is distributed in the hope that it will be useful,
|
|
|
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
|
19 * GNU General Public License for more details.
|
|
|
20 *
|
|
|
21 * You should have received a copy of the GNU General Public License
|
|
|
22 * along with this program; if not, write to the Free Software
|
|
|
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
|
24 *
|
|
|
25 * $Id: hdlc.c,v 1.44 2006/11/28 16:59:56 steveu Exp $
|
|
|
26 */
|
|
|
27
|
|
|
28 /*! \file */
|
|
|
29
|
|
|
30 #ifdef HAVE_CONFIG_H
|
|
|
31 #include <config.h>
|
|
|
32 #endif
|
|
|
33
|
|
|
34 #include <inttypes.h>
|
|
|
35 #include <stdio.h>
|
|
|
36 #include <string.h>
|
|
|
37
|
|
|
38 #include "spandsp/telephony.h"
|
|
|
39 #include "spandsp/power_meter.h"
|
|
|
40 #include "spandsp/async.h"
|
|
|
41 #include "spandsp/hdlc.h"
|
|
|
42 #include "spandsp/fsk.h"
|
|
|
43 #include "spandsp/bit_operations.h"
|
|
|
44
|
|
|
45 #include "spandsp/timing.h"
|
|
|
46
|
|
|
47 static const uint32_t crc_itu32_table[] =
|
|
|
48 {
|
|
|
49 0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA,
|
|
|
50 0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3,
|
|
|
51 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988,
|
|
|
52 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91,
|
|
|
53 0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE,
|
|
|
54 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,
|
|
|
55 0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC,
|
|
|
56 0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5,
|
|
|
57 0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172,
|
|
|
58 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B,
|
|
|
59 0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940,
|
|
|
60 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,
|
|
|
61 0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116,
|
|
|
62 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F,
|
|
|
63 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924,
|
|
|
64 0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D,
|
|
|
65 0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A,
|
|
|
66 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,
|
|
|
67 0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818,
|
|
|
68 0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01,
|
|
|
69 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E,
|
|
|
70 0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457,
|
|
|
71 0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C,
|
|
|
72 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,
|
|
|
73 0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2,
|
|
|
74 0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB,
|
|
|
75 0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0,
|
|
|
76 0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9,
|
|
|
77 0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086,
|
|
|
78 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
|
|
|
79 0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4,
|
|
|
80 0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD,
|
|
|
81 0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A,
|
|
|
82 0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683,
|
|
|
83 0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8,
|
|
|
84 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,
|
|
|
85 0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE,
|
|
|
86 0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7,
|
|
|
87 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC,
|
|
|
88 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5,
|
|
|
89 0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252,
|
|
|
90 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,
|
|
|
91 0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60,
|
|
|
92 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79,
|
|
|
93 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236,
|
|
|
94 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F,
|
|
|
95 0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04,
|
|
|
96 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,
|
|
|
97 0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A,
|
|
|
98 0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713,
|
|
|
99 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38,
|
|
|
100 0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21,
|
|
|
101 0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E,
|
|
|
102 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,
|
|
|
103 0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C,
|
|
|
104 0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45,
|
|
|
105 0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2,
|
|
|
106 0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB,
|
|
|
107 0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0,
|
|
|
108 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,
|
|
|
109 0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6,
|
|
|
110 0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF,
|
|
|
111 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94,
|
|
|
112 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D
|
|
|
113 };
|
|
|
114
|
|
|
115 uint32_t crc_itu32_calc(const uint8_t *buf, int len, uint32_t crc)
|
|
|
116 {
|
|
|
117 int i;
|
|
|
118
|
|
|
119 for (i = 0; i < len; i++)
|
|
|
120 crc = ((crc >> 8) & 0x00FFFFFF) ^ crc_itu32_table[(crc ^ buf[i]) & 0xFF];
|
|
|
121 return crc;
|
|
|
122 }
|
|
|
123 /*- End of function --------------------------------------------------------*/
|
|
|
124
|
|
|
125 int crc_itu32_append(uint8_t *buf, int len)
|
|
|
126 {
|
|
|
127 uint32_t crc;
|
|
|
128 int new_len;
|
|
|
129 int i;
|
|
|
130
|
|
|
131 crc = 0xFFFFFFFF;
|
|
|
132 new_len = len + 4;
|
|
|
133 for (i = 0; i < len; i++)
|
|
|
134 crc = ((crc >> 8) & 0x00FFFFFF) ^ crc_itu32_table[(crc ^ buf[i]) & 0xFF];
|
|
|
135 crc ^= 0xFFFFFFFF;
|
|
|
136 buf[i++] = (uint8_t) crc;
|
|
|
137 buf[i++] = (uint8_t) (crc >> 8);
|
|
|
138 buf[i++] = (uint8_t) (crc >> 16);
|
|
|
139 buf[i++] = (uint8_t) (crc >> 24);
|
|
|
140 return new_len;
|
|
|
141 }
|
|
|
142 /*- End of function --------------------------------------------------------*/
|
|
|
143
|
|
|
144 int crc_itu32_check(const uint8_t *buf, int len)
|
|
|
145 {
|
|
|
146 uint32_t crc;
|
|
|
147 int i;
|
|
|
148
|
|
|
149 crc = 0xFFFFFFFF;
|
|
|
150 for (i = 0; i < len; i++)
|
|
|
151 crc = ((crc >> 8) & 0x00FFFFFF) ^ crc_itu32_table[(crc ^ buf[i]) & 0xFF];
|
|
|
152 return (crc == 0xDEBB20E3);
|
|
|
153 }
|
|
|
154 /*- End of function --------------------------------------------------------*/
|
|
|
155
|
|
|
156 static const uint16_t crc_itu16_table[] =
|
|
|
157 {
|
|
|
158 0x0000, 0x1189, 0x2312, 0x329B, 0x4624, 0x57AD, 0x6536, 0x74BF,
|
|
|
159 0x8C48, 0x9DC1, 0xAF5A, 0xBED3, 0xCA6C, 0xDBE5, 0xE97E, 0xF8F7,
|
|
|
160 0x1081, 0x0108, 0x3393, 0x221A, 0x56A5, 0x472C, 0x75B7, 0x643E,
|
|
|
161 0x9CC9, 0x8D40, 0xBFDB, 0xAE52, 0xDAED, 0xCB64, 0xF9FF, 0xE876,
|
|
|
162 0x2102, 0x308B, 0x0210, 0x1399, 0x6726, 0x76AF, 0x4434, 0x55BD,
|
|
|
163 0xAD4A, 0xBCC3, 0x8E58, 0x9FD1, 0xEB6E, 0xFAE7, 0xC87C, 0xD9F5,
|
|
|
164 0x3183, 0x200A, 0x1291, 0x0318, 0x77A7, 0x662E, 0x54B5, 0x453C,
|
|
|
165 0xBDCB, 0xAC42, 0x9ED9, 0x8F50, 0xFBEF, 0xEA66, 0xD8FD, 0xC974,
|
|
|
166 0x4204, 0x538D, 0x6116, 0x709F, 0x0420, 0x15A9, 0x2732, 0x36BB,
|
|
|
167 0xCE4C, 0xDFC5, 0xED5E, 0xFCD7, 0x8868, 0x99E1, 0xAB7A, 0xBAF3,
|
|
|
168 0x5285, 0x430C, 0x7197, 0x601E, 0x14A1, 0x0528, 0x37B3, 0x263A,
|
|
|
169 0xDECD, 0xCF44, 0xFDDF, 0xEC56, 0x98E9, 0x8960, 0xBBFB, 0xAA72,
|
|
|
170 0x6306, 0x728F, 0x4014, 0x519D, 0x2522, 0x34AB, 0x0630, 0x17B9,
|
|
|
171 0xEF4E, 0xFEC7, 0xCC5C, 0xDDD5, 0xA96A, 0xB8E3, 0x8A78, 0x9BF1,
|
|
|
172 0x7387, 0x620E, 0x5095, 0x411C, 0x35A3, 0x242A, 0x16B1, 0x0738,
|
|
|
173 0xFFCF, 0xEE46, 0xDCDD, 0xCD54, 0xB9EB, 0xA862, 0x9AF9, 0x8B70,
|
|
|
174 0x8408, 0x9581, 0xA71A, 0xB693, 0xC22C, 0xD3A5, 0xE13E, 0xF0B7,
|
|
|
175 0x0840, 0x19C9, 0x2B52, 0x3ADB, 0x4E64, 0x5FED, 0x6D76, 0x7CFF,
|
|
|
176 0x9489, 0x8500, 0xB79B, 0xA612, 0xD2AD, 0xC324, 0xF1BF, 0xE036,
|
|
|
177 0x18C1, 0x0948, 0x3BD3, 0x2A5A, 0x5EE5, 0x4F6C, 0x7DF7, 0x6C7E,
|
|
|
178 0xA50A, 0xB483, 0x8618, 0x9791, 0xE32E, 0xF2A7, 0xC03C, 0xD1B5,
|
|
|
179 0x2942, 0x38CB, 0x0A50, 0x1BD9, 0x6F66, 0x7EEF, 0x4C74, 0x5DFD,
|
|
|
180 0xB58B, 0xA402, 0x9699, 0x8710, 0xF3AF, 0xE226, 0xD0BD, 0xC134,
|
|
|
181 0x39C3, 0x284A, 0x1AD1, 0x0B58, 0x7FE7, 0x6E6E, 0x5CF5, 0x4D7C,
|
|
|
182 0xC60C, 0xD785, 0xE51E, 0xF497, 0x8028, 0x91A1, 0xA33A, 0xB2B3,
|
|
|
183 0x4A44, 0x5BCD, 0x6956, 0x78DF, 0x0C60, 0x1DE9, 0x2F72, 0x3EFB,
|
|
|
184 0xD68D, 0xC704, 0xF59F, 0xE416, 0x90A9, 0x8120, 0xB3BB, 0xA232,
|
|
|
185 0x5AC5, 0x4B4C, 0x79D7, 0x685E, 0x1CE1, 0x0D68, 0x3FF3, 0x2E7A,
|
|
|
186 0xE70E, 0xF687, 0xC41C, 0xD595, 0xA12A, 0xB0A3, 0x8238, 0x93B1,
|
|
|
187 0x6B46, 0x7ACF, 0x4854, 0x59DD, 0x2D62, 0x3CEB, 0x0E70, 0x1FF9,
|
|
|
188 0xF78F, 0xE606, 0xD49D, 0xC514, 0xB1AB, 0xA022, 0x92B9, 0x8330,
|
|
|
189 0x7BC7, 0x6A4E, 0x58D5, 0x495C, 0x3DE3, 0x2C6A, 0x1EF1, 0x0F78
|
|
|
190 };
|
|
|
191
|
|
|
192 uint16_t crc_itu16_calc(const uint8_t *buf, int len, uint16_t crc)
|
|
|
193 {
|
|
|
194 int i;
|
|
|
195
|
|
|
196 for (i = 0; i < len; i++)
|
|
|
197 crc = (crc >> 8) ^ crc_itu16_table[(crc ^ buf[i]) & 0xFF];
|
|
|
198 return crc;
|
|
|
199 }
|
|
|
200 /*- End of function --------------------------------------------------------*/
|
|
|
201
|
|
|
202 int crc_itu16_append(uint8_t *buf, int len)
|
|
|
203 {
|
|
|
204 uint16_t crc;
|
|
|
205 int new_len;
|
|
|
206 int i;
|
|
|
207
|
|
|
208 crc = 0xFFFF;
|
|
|
209 new_len = len + 2;
|
|
|
210 for (i = 0; i < len; i++)
|
|
|
211 crc = (crc >> 8) ^ crc_itu16_table[(crc ^ buf[i]) & 0xFF];
|
|
|
212 crc ^= 0xFFFF;
|
|
|
213 buf[i++] = (uint8_t) crc;
|
|
|
214 buf[i++] = (uint8_t) (crc >> 8);
|
|
|
215 return new_len;
|
|
|
216 }
|
|
|
217 /*- End of function --------------------------------------------------------*/
|
|
|
218
|
|
|
219 int crc_itu16_check(const uint8_t *buf, int len)
|
|
|
220 {
|
|
|
221 uint16_t crc;
|
|
|
222 int i;
|
|
|
223
|
|
|
224 crc = 0xFFFF;
|
|
|
225 for (i = 0; i < len; i++)
|
|
|
226 crc = (crc >> 8) ^ crc_itu16_table[(crc ^ buf[i]) & 0xFF];
|
|
|
227 return (crc & 0xFFFF) == 0xF0B8;
|
|
|
228 }
|
|
|
229 /*- End of function --------------------------------------------------------*/
|
|
|
230
|
|
|
231 static void rx_special_condition(hdlc_rx_state_t *s, int condition)
|
|
|
232 {
|
|
|
233 /* Special conditions */
|
|
|
234 switch (condition)
|
|
|
235 {
|
|
|
236 case PUTBIT_CARRIER_UP:
|
|
|
237 case PUTBIT_TRAINING_SUCCEEDED:
|
|
|
238 /* Reset the HDLC receiver. */
|
|
|
239 s->len = 0;
|
|
|
240 s->num_bits = 0;
|
|
|
241 s->flags_seen = 0;
|
|
|
242 s->framing_ok_announced = FALSE;
|
|
|
243 /* Fall through */
|
|
|
244 case PUTBIT_CARRIER_DOWN:
|
|
|
245 case PUTBIT_TRAINING_FAILED:
|
|
|
246 case PUTBIT_END_OF_DATA:
|
|
|
247 s->frame_handler(s->user_data, TRUE, NULL, condition);
|
|
|
248 break;
|
|
|
249 default:
|
|
|
250 //printf("Eh!\n");
|
|
|
251 break;
|
|
|
252 }
|
|
|
253 }
|
|
|
254 /*- End of function --------------------------------------------------------*/
|
|
|
255
|
|
|
256 static void rx_flag_or_abort(hdlc_rx_state_t *s)
|
|
|
257 {
|
|
|
258 if ((s->raw_bit_stream & 0x8000))
|
|
|
259 {
|
|
|
260 /* Hit HDLC abort */
|
|
|
261 s->rx_aborts++;
|
|
|
262 s->frame_handler(s->user_data, TRUE, NULL, PUTBIT_ABORT);
|
|
|
263 if (s->flags_seen < s->framing_ok_threshold)
|
|
|
264 s->flags_seen = 0;
|
|
|
265 }
|
|
|
266 else
|
|
|
267 {
|
|
|
268 /* Hit HDLC flag */
|
|
|
269 if (s->flags_seen >= s->framing_ok_threshold)
|
|
|
270 {
|
|
|
271 /* Announce framing OK between frames. */
|
|
|
272 if (!s->framing_ok_announced)
|
|
|
273 {
|
|
|
274 s->frame_handler(s->user_data, TRUE, NULL, PUTBIT_FRAMING_OK);
|
|
|
275 s->framing_ok_announced = TRUE;
|
|
|
276 }
|
|
|
277 /* We may have a frame, or we may have back to back flags */
|
|
|
278 if (s->len)
|
|
|
279 {
|
|
|
280 if (s->len >= s->crc_bytes && s->len <= (int) sizeof(s->buffer))
|
|
|
281 {
|
|
|
282 if ((s->crc_bytes == 2 && crc_itu16_check(s->buffer, s->len))
|
|
|
283 ||
|
|
|
284 (s->crc_bytes != 2 && crc_itu32_check(s->buffer, s->len)))
|
|
|
285 {
|
|
|
286 s->rx_frames++;
|
|
|
287 s->rx_bytes += s->len - s->crc_bytes;
|
|
|
288 s->frame_handler(s->user_data,
|
|
|
289 TRUE,
|
|
|
290 s->buffer,
|
|
|
291 s->len - s->crc_bytes);
|
|
|
292 }
|
|
|
293 else
|
|
|
294 {
|
|
|
295 s->rx_crc_errors++;
|
|
|
296 if (s->report_bad_frames)
|
|
|
297 {
|
|
|
298 s->frame_handler(s->user_data,
|
|
|
299 FALSE,
|
|
|
300 s->buffer,
|
|
|
301 s->len - s->crc_bytes);
|
|
|
302 }
|
|
|
303 }
|
|
|
304 s->framing_ok_announced = FALSE;
|
|
|
305 }
|
|
|
306 else
|
|
|
307 {
|
|
|
308 /* Frame too short or too long */
|
|
|
309 if (s->report_bad_frames)
|
|
|
310 {
|
|
|
311 s->frame_handler(s->user_data,
|
|
|
312 FALSE,
|
|
|
313 s->buffer,
|
|
|
314 s->len - s->crc_bytes);
|
|
|
315 }
|
|
|
316 s->rx_length_errors++;
|
|
|
317 }
|
|
|
318 }
|
|
|
319 }
|
|
|
320 else
|
|
|
321 {
|
|
|
322 /* Check the flags are back-to-back when testing for valid preamble. This
|
|
|
323 greatly reduces the chances of false preamble detection, and anything
|
|
|
324 which doesn't send them back-to-back is badly broken. */
|
|
|
325 if (s->flags_seen && s->num_bits != 7)
|
|
|
326 s->flags_seen = 0;
|
|
|
327 if (++s->flags_seen == s->framing_ok_threshold && !s->framing_ok_announced)
|
|
|
328 {
|
|
|
329 s->frame_handler(s->user_data, TRUE, NULL, PUTBIT_FRAMING_OK);
|
|
|
330 s->framing_ok_announced = TRUE;
|
|
|
331 }
|
|
|
332 }
|
|
|
333 }
|
|
|
334 s->len = 0;
|
|
|
335 s->num_bits = 0;
|
|
|
336 }
|
|
|
337 /*- End of function --------------------------------------------------------*/
|
|
|
338
|
|
|
339 void hdlc_rx_put_bit(hdlc_rx_state_t *s, int new_bit)
|
|
|
340 {
|
|
|
341 if (new_bit < 0)
|
|
|
342 {
|
|
|
343 rx_special_condition(s, new_bit);
|
|
|
344 return;
|
|
|
345 }
|
|
|
346 s->raw_bit_stream = (s->raw_bit_stream << 1) | ((new_bit << 8) & 0x100);
|
|
|
347 if ((s->raw_bit_stream & 0x3F00) == 0x3E00)
|
|
|
348 {
|
|
|
349 if ((s->raw_bit_stream & 0x4000))
|
|
|
350 {
|
|
|
351 rx_flag_or_abort(s);
|
|
|
352 }
|
|
|
353 else
|
|
|
354 {
|
|
|
355 if (s->flags_seen < s->framing_ok_threshold)
|
|
|
356 s->num_bits++;
|
|
|
357 }
|
|
|
358 }
|
|
|
359 else
|
|
|
360 {
|
|
|
361 s->num_bits++;
|
|
|
362 if (s->flags_seen >= s->framing_ok_threshold)
|
|
|
363 {
|
|
|
364 s->byte_in_progress = (s->byte_in_progress | (s->raw_bit_stream & 0x100)) >> 1;
|
|
|
365 if (s->num_bits == 8)
|
|
|
366 {
|
|
|
367 /* Ensure we do not overflow our buffer */
|
|
|
368 if (s->len < (int) sizeof(s->buffer))
|
|
|
369 s->buffer[s->len++] = (uint8_t) s->byte_in_progress;
|
|
|
370 else
|
|
|
371 s->len = (int) sizeof(s->buffer) + 1;
|
|
|
372 s->num_bits = 0;
|
|
|
373 }
|
|
|
374 }
|
|
|
375 }
|
|
|
376 }
|
|
|
377 /*- End of function --------------------------------------------------------*/
|
|
|
378
|
|
|
379 void hdlc_rx_put_byte(hdlc_rx_state_t *s, int new_byte)
|
|
|
380 {
|
|
|
381 int i;
|
|
|
382
|
|
|
383 if (new_byte < 0)
|
|
|
384 {
|
|
|
385 rx_special_condition(s, new_byte);
|
|
|
386 return;
|
|
|
387 }
|
|
|
388 s->raw_bit_stream |= new_byte;
|
|
|
389
|
|
|
390 i = 0;
|
|
|
391 if (s->flags_seen < s->framing_ok_threshold)
|
|
|
392 {
|
|
|
393 for ( ; i < 8; i++)
|
|
|
394 {
|
|
|
395 s->raw_bit_stream <<= 1;
|
|
|
396 if ((s->raw_bit_stream & 0x7F00) == 0x7E00)
|
|
|
397 {
|
|
|
398 rx_flag_or_abort(s);
|
|
|
399 if (s->flags_seen >= s->framing_ok_threshold)
|
|
|
400 {
|
|
|
401 i++;
|
|
|
402 break;
|
|
|
403 }
|
|
|
404 }
|
|
|
405 else
|
|
|
406 {
|
|
|
407 s->num_bits++;
|
|
|
408 }
|
|
|
409 }
|
|
|
410 }
|
|
|
411 for ( ; i < 8; i++)
|
|
|
412 {
|
|
|
413 s->raw_bit_stream <<= 1;
|
|
|
414 if ((s->raw_bit_stream & 0x3F00) == 0x3E00)
|
|
|
415 {
|
|
|
416 if ((s->raw_bit_stream & 0x4000))
|
|
|
417 rx_flag_or_abort(s);
|
|
|
418 }
|
|
|
419 else
|
|
|
420 {
|
|
|
421 s->byte_in_progress = (s->byte_in_progress | (s->raw_bit_stream & 0x100)) >> 1;
|
|
|
422 if (++s->num_bits == 8)
|
|
|
423 {
|
|
|
424 /* Ensure we do not overflow our buffer */
|
|
|
425 if (s->len < (int) sizeof(s->buffer))
|
|
|
426 s->buffer[s->len++] = (uint8_t) s->byte_in_progress;
|
|
|
427 else
|
|
|
428 s->len = (int) sizeof(s->buffer) + 1;
|
|
|
429 s->num_bits = 0;
|
|
|
430 }
|
|
|
431 }
|
|
|
432 }
|
|
|
433 }
|
|
|
434 /*- End of function --------------------------------------------------------*/
|
|
|
435
|
|
|
436 int hdlc_tx_frame(hdlc_tx_state_t *s, const uint8_t *frame, int len)
|
|
|
437 {
|
|
|
438 if (len <= 0)
|
|
|
439 {
|
|
|
440 s->tx_end = TRUE;
|
|
|
441 return 0;
|
|
|
442 }
|
|
|
443 if (s->len + len > s->max_frame_len)
|
|
|
444 return -1;
|
|
|
445 if (s->progressive)
|
|
|
446 {
|
|
|
447 /* Only lock out if we are in the CRC section. */
|
|
|
448 if (s->pos >= HDLC_MAXFRAME_LEN)
|
|
|
449 return -1;
|
|
|
450 }
|
|
|
451 else
|
|
|
452 {
|
|
|
453 /* Lock out if there is anything in the buffer. */
|
|
|
454 if (s->len)
|
|
|
455 return -1;
|
|
|
456 }
|
|
|
457 memcpy(s->buffer + s->len, frame, len);
|
|
|
458 if (s->crc_bytes == 2)
|
|
|
459 s->crc = crc_itu16_calc(frame, len, (uint16_t) s->crc);
|
|
|
460 else
|
|
|
461 s->crc = crc_itu32_calc(frame, len, s->crc);
|
|
|
462 if (s->progressive)
|
|
|
463 s->len += len;
|
|
|
464 else
|
|
|
465 s->len = len;
|
|
|
466 s->tx_end = FALSE;
|
|
|
467 return 0;
|
|
|
468 }
|
|
|
469 /*- End of function --------------------------------------------------------*/
|
|
|
470
|
|
|
471 int hdlc_tx_preamble(hdlc_tx_state_t *s, int len)
|
|
|
472 {
|
|
|
473 /* Some HDLC applications require the ability to force a period of HDLC
|
|
|
474 flag words. */
|
|
|
475 if (s->pos)
|
|
|
476 return -1;
|
|
|
477 if (len < 0)
|
|
|
478 s->flag_octets += -len;
|
|
|
479 else
|
|
|
480 s->flag_octets = len;
|
|
|
481 s->report_flag_underflow = TRUE;
|
|
|
482 s->tx_end = FALSE;
|
|
|
483 return 0;
|
|
|
484 }
|
|
|
485 /*- End of function --------------------------------------------------------*/
|
|
|
486
|
|
|
487 int hdlc_tx_corrupt_frame(hdlc_tx_state_t *s)
|
|
|
488 {
|
|
|
489 if (s->len <= 0)
|
|
|
490 return -1;
|
|
|
491 s->crc ^= 0xFFFF;
|
|
|
492 s->buffer[HDLC_MAXFRAME_LEN] ^= 0xFF;
|
|
|
493 s->buffer[HDLC_MAXFRAME_LEN + 1] ^= 0xFF;
|
|
|
494 s->buffer[HDLC_MAXFRAME_LEN + 2] ^= 0xFF;
|
|
|
495 s->buffer[HDLC_MAXFRAME_LEN + 3] ^= 0xFF;
|
|
|
496 return 0;
|
|
|
497 }
|
|
|
498 /*- End of function --------------------------------------------------------*/
|
|
|
499
|
|
|
500 int hdlc_tx_get_byte(hdlc_tx_state_t *s)
|
|
|
501 {
|
|
|
502 int i;
|
|
|
503 int byte_in_progress;
|
|
|
504 int txbyte;
|
|
|
505
|
|
|
506 if (s->flag_octets > 0)
|
|
|
507 {
|
|
|
508 /* We are in a timed flag section (preamble, inter frame gap, etc.) */
|
|
|
509 if (--s->flag_octets <= 0 && s->report_flag_underflow)
|
|
|
510 {
|
|
|
511 if (s->len == 0)
|
|
|
512 {
|
|
|
513 /* The timed preamble has finished, there is nothing else queued to go,
|
|
|
514 and we have been told to report this underflow. */
|
|
|
515 if (s->underflow_handler)
|
|
|
516 s->underflow_handler(s->user_data);
|
|
|
517 }
|
|
|
518 s->report_flag_underflow = FALSE;
|
|
|
519 }
|
|
|
520 return s->idle_octet;
|
|
|
521 }
|
|
|
522 if (s->len)
|
|
|
523 {
|
|
|
524 if (s->num_bits >= 8)
|
|
|
525 {
|
|
|
526 s->num_bits -= 8;
|
|
|
527 return (s->octets_in_progress >> s->num_bits) & 0xFF;
|
|
|
528 }
|
|
|
529 if (s->pos >= s->len)
|
|
|
530 {
|
|
|
531 if (s->pos == s->len)
|
|
|
532 {
|
|
|
533 s->crc ^= 0xFFFFFFFF;
|
|
|
534 s->buffer[HDLC_MAXFRAME_LEN] = (uint8_t) s->crc;
|
|
|
535 s->buffer[HDLC_MAXFRAME_LEN + 1] = (uint8_t) (s->crc >> 8);
|
|
|
536 if (s->crc_bytes == 4)
|
|
|
537 {
|
|
|
538 s->buffer[HDLC_MAXFRAME_LEN + 2] = (uint8_t) (s->crc >> 16);
|
|
|
539 s->buffer[HDLC_MAXFRAME_LEN + 3] = (uint8_t) (s->crc >> 24);
|
|
|
540 }
|
|
|
541 s->pos = HDLC_MAXFRAME_LEN;
|
|
|
542 }
|
|
|
543 else if (s->pos == HDLC_MAXFRAME_LEN + s->crc_bytes)
|
|
|
544 {
|
|
|
545 /* Finish off the current byte with some flag bits. If we are at the
|
|
|
546 start of a byte we need a at least one whole byte of flag to ensure
|
|
|
547 we cannot end up with back to back frames, and no flag octet at all */
|
|
|
548 txbyte = (uint8_t) ((s->octets_in_progress << (8 - s->num_bits)) | (0x7E >> s->num_bits));
|
|
|
549 /* Create a rotated octet of flag for idling... */
|
|
|
550 s->idle_octet = (0x7E7E >> s->num_bits) & 0xFF;
|
|
|
551 /* ...and the partial flag octet needed to start off the next message. */
|
|
|
552 s->octets_in_progress = s->idle_octet >> (8 - s->num_bits);
|
|
|
553 s->flag_octets = s->inter_frame_flags - 1;
|
|
|
554 s->len = 0;
|
|
|
555 s->pos = 0;
|
|
|
556 if (s->crc_bytes == 2)
|
|
|
557 s->crc = 0xFFFF;
|
|
|
558 else
|
|
|
559 s->crc = 0xFFFFFFFF;
|
|
|
560 /* Report the underflow now. If there is a timed preamble still in progress, loading the
|
|
|
561 next frame right now will be harmless. */
|
|
|
562 s->report_flag_underflow = FALSE;
|
|
|
563 if (s->underflow_handler)
|
|
|
564 s->underflow_handler(s->user_data);
|
|
|
565 /* Make sure we finish off with at least one flag octet, if the underflow report did not result
|
|
|
566 in a new frame being sent. */
|
|
|
567 if (s->len == 0 && s->flag_octets < 2)
|
|
|
568 s->flag_octets = 2;
|
|
|
569 return txbyte;
|
|
|
570 }
|
|
|
571 }
|
|
|
572 byte_in_progress = s->buffer[s->pos++];
|
|
|
573 i = bottom_bit(byte_in_progress | 0x100);
|
|
|
574 s->octets_in_progress <<= i;
|
|
|
575 byte_in_progress >>= i;
|
|
|
576 for ( ; i < 8; i++)
|
|
|
577 {
|
|
|
578 s->octets_in_progress = (s->octets_in_progress << 1) | (byte_in_progress & 0x01);
|
|
|
579 byte_in_progress >>= 1;
|
|
|
580 if ((s->octets_in_progress & 0x1F) == 0x1F)
|
|
|
581 {
|
|
|
582 /* There are 5 ones - stuff */
|
|
|
583 s->octets_in_progress <<= 1;
|
|
|
584 s->num_bits++;
|
|
|
585 }
|
|
|
586 }
|
|
|
587 /* An input byte will generate between 8 and 10 output bits */
|
|
|
588 return (s->octets_in_progress >> s->num_bits) & 0xFF;
|
|
|
589 }
|
|
|
590 /* Untimed idling on flags */
|
|
|
591 if (s->tx_end)
|
|
|
592 {
|
|
|
593 s->tx_end = FALSE;
|
|
|
594 return PUTBIT_END_OF_DATA;
|
|
|
595 }
|
|
|
596 return s->idle_octet;
|
|
|
597 }
|
|
|
598 /*- End of function --------------------------------------------------------*/
|
|
|
599
|
|
|
600 int hdlc_tx_get_bit(hdlc_tx_state_t *s)
|
|
|
601 {
|
|
|
602 int txbit;
|
|
|
603
|
|
|
604 if (s->bits == 0)
|
|
|
605 {
|
|
|
606 if ((s->byte = hdlc_tx_get_byte(s)) < 0)
|
|
|
607 return s->byte;
|
|
|
608 s->bits = 8;
|
|
|
609 }
|
|
|
610 s->bits--;
|
|
|
611 txbit = (s->byte >> s->bits) & 0x01;
|
|
|
612 return txbit;
|
|
|
613 }
|
|
|
614 /*- End of function --------------------------------------------------------*/
|
|
|
615
|
|
|
616 hdlc_rx_state_t *hdlc_rx_init(hdlc_rx_state_t *s,
|
|
|
617 int crc32,
|
|
|
618 int report_bad_frames,
|
|
|
619 int framing_ok_threshold,
|
|
|
620 hdlc_frame_handler_t handler,
|
|
|
621 void *user_data)
|
|
|
622 {
|
|
|
623 memset(s, 0, sizeof(*s));
|
|
|
624 s->frame_handler = handler;
|
|
|
625 s->user_data = user_data;
|
|
|
626 s->crc_bytes = (crc32) ? 4 : 2;
|
|
|
627 s->report_bad_frames = report_bad_frames;
|
|
|
628 s->framing_ok_threshold = (framing_ok_threshold < 1) ? 1 : framing_ok_threshold;
|
|
|
629 return s;
|
|
|
630 }
|
|
|
631 /*- End of function --------------------------------------------------------*/
|
|
|
632
|
|
|
633 int hdlc_rx_get_stats(hdlc_rx_state_t *s,
|
|
|
634 hdlc_rx_stats_t *t)
|
|
|
635 {
|
|
|
636 t->bytes = s->rx_bytes;
|
|
|
637 t->good_frames = s->rx_frames;
|
|
|
638 t->crc_errors = s->rx_crc_errors;
|
|
|
639 t->length_errors = s->rx_length_errors;
|
|
|
640 t->aborts = s->rx_aborts;
|
|
|
641 return 0;
|
|
|
642 }
|
|
|
643 /*- End of function --------------------------------------------------------*/
|
|
|
644
|
|
|
645 void hdlc_tx_set_max_frame_len(hdlc_tx_state_t *s, int max_len)
|
|
|
646 {
|
|
|
647 s->max_frame_len = (max_len <= HDLC_MAXFRAME_LEN) ? max_len : HDLC_MAXFRAME_LEN;
|
|
|
648 }
|
|
|
649 /*- End of function --------------------------------------------------------*/
|
|
|
650
|
|
|
651 hdlc_tx_state_t *hdlc_tx_init(hdlc_tx_state_t *s,
|
|
|
652 int crc32,
|
|
|
653 int inter_frame_flags,
|
|
|
654 int progressive,
|
|
|
655 hdlc_underflow_handler_t handler,
|
|
|
656 void *user_data)
|
|
|
657 {
|
|
|
658 memset(s, 0, sizeof(*s));
|
|
|
659 s->idle_octet = 0x7E;
|
|
|
660 s->underflow_handler = handler;
|
|
|
661 s->user_data = user_data;
|
|
|
662 s->inter_frame_flags = (inter_frame_flags < 1) ? 1 : inter_frame_flags;
|
|
|
663 if (crc32)
|
|
|
664 {
|
|
|
665 s->crc_bytes = 4;
|
|
|
666 s->crc = 0xFFFFFFFF;
|
|
|
667 }
|
|
|
668 else
|
|
|
669 {
|
|
|
670 s->crc_bytes = 2;
|
|
|
671 s->crc = 0xFFFF;
|
|
|
672 }
|
|
|
673 s->progressive = progressive;
|
|
|
674 s->max_frame_len = HDLC_MAXFRAME_LEN;
|
|
|
675 return s;
|
|
|
676 }
|
|
|
677 /*- End of function --------------------------------------------------------*/
|
|
|
678 /*- End of file ------------------------------------------------------------*/
|
