1

/*

     2

  This file is part of Beremiz, a Integrated Development Environment for

     3

  programming IEC 61131-3 automates supporting plcopen standard and CanFestival.

     4

     5

  See COPYING.runtime

     6

     7

  Copyright (C) 2018: Sergey Surkov <surkov.sv@summatechnology.ru>

     8

  Copyright (C) 2018: Andrey Skvortsov <andrej.skvortzov@gmail.com>

     9

    10

*/

    11

    12

#ifndef HAVE_RETAIN

    13

#include <stdio.h>

    14

#include <stdint.h>

    15

#include <unistd.h>

    16

#include "iec_types.h"

    17

    18

int GetRetainSize(void);

    19

    20

/* Retain buffer.  */

    21

FILE *retain_buffer;

    22

const char rb_file[]      = "retain_buffer_file";

    23

const char rb_file_bckp[] = "retain_buffer_file.bak";

    24

    25

    26

/* Retain header struct.  */

    27

struct retain_info_t {

    28

	uint32_t retain_size;

    29

	uint32_t hash_size;

    30

	uint8_t* hash;

    31

	uint32_t header_offset;

    32

	uint32_t header_crc;

    33

};

    34

    35

/* Init retain info structure.  */

    36

struct retain_info_t retain_info;

    37

    38

/* CRC lookup table and initial state.  */

    39

static const uint32_t crc32_table[256] = {

    40

	0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3,

    41

	0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91,

    42

	0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,

    43

	0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5,

    44

	0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172, 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B,

    45

	0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,

    46

	0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F,

    47

	0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D,

    48

	0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,

    49

	0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01,

    50

	0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457,

    51

	0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,

    52

	0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB,

    53

	0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9,

    54

	0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,

    55

	0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD,

    56

	0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683,

    57

	0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,

    58

	0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7,

    59

	0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5,

    60

	0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,

    61

	0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79,

    62

	0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F,

    63

	0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,

    64

	0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713,

    65

	0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21,

    66

	0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,

    67

	0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45,

    68

	0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB,

    69

	0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,

    70

	0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF,

    71

	0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D,

    72

};

    73

uint32_t retain_crc;

    74

    75

    76

/* Calculate CRC32 for len bytes from pointer buf with init starting value.  */

    77

uint32_t GenerateCRC32Sum(const void* buf, unsigned int len, uint32_t init)

    78

{

    79

	uint32_t crc = ~init;

    80

	unsigned char* current = (unsigned char*) buf;

    81

	while (len--)

    82

		crc = crc32_table[(crc ^ *current++) & 0xFF] ^ (crc >> 8);

    83

	return ~crc;

    84

}

    85

    86

/* Calc CRC32 for retain file byte by byte.  */

    87

int CheckFileCRC(FILE* file_buffer)

    88

{

    89

	/* Set the magic constant for one-pass CRC calc according to ZIP CRC32.  */

    90

	const uint32_t magic_number = 0x2144df1c;

    91

    92

	/* CRC initial state.  */

    93

	uint32_t calc_crc32 = 0;

    94

	char data_block = 0;

    95

    96

	while(!feof(file_buffer)){

    97

		if (fread(&data_block, sizeof(data_block), 1, file_buffer))

    98

			calc_crc32 = GenerateCRC32Sum(&data_block, sizeof(data_block), calc_crc32);

    99

	}

   100

   101

	/* Compare crc result with a magic number.  */

   102

	return (calc_crc32 == magic_number) ? 1 : 0;

   103

}

   104

   105

/* Compare current hash with hash from file byte by byte.  */

   106

int CheckFilehash(void)

   107

{

   108

	unsigned int k;

   109

	int offset = sizeof(retain_info.retain_size);

   110

   111

	rewind(retain_buffer);

   112

	fseek(retain_buffer, offset , SEEK_SET);

   113

   114

	uint32_t size;

   115

	fread(&size, sizeof(size), 1, retain_buffer);

   116

	if (size != retain_info.hash_size)

   117

		return 0;

   118

   119

	for(k = 0; k < retain_info.hash_size; k++){

   120

		uint8_t file_digit;

   121

		fread(&file_digit, sizeof(file_digit), 1, retain_buffer);

   122

		if (file_digit != *(retain_info.hash+k))

   123

			return 0;

   124

	}

   125

   126

	return 1;

   127

}

   128

   129

void InitRetain(void)

   130

{

   131

	unsigned int i;

   132

   133

	/* Get retain size in bytes */

   134

	retain_info.retain_size = GetRetainSize();

   135

   136

	/* Hash stored in retain file as array of char in hex digits

   137

	   (that's why we divide strlen in two).  */

   138

	retain_info.hash_size = PLC_ID ? strlen(PLC_ID)/2 : 0;

   139

	//retain_info.hash_size = 0;

   140

	retain_info.hash = malloc(retain_info.hash_size);

   141

   142

	/* Transform hash string into byte sequence.  */

   143

	for (i = 0; i < retain_info.hash_size; i++) {

   144

		int byte = 0;

   145

		sscanf((PLC_ID + i*2), "%02X", &byte);

   146

		retain_info.hash[i] = byte;

   147

	}

   148

   149

	/* Calc header offset.  */

   150

	retain_info.header_offset = sizeof(retain_info.retain_size) + \

   151

		sizeof(retain_info.hash_size) + \

   152

		retain_info.hash_size;

   153

   154

	/*  Set header CRC initial state.  */

   155

	retain_info.header_crc = 0;

   156

   157

	/* Calc crc for header.  */

   158

	retain_info.header_crc = GenerateCRC32Sum(

   159

		&retain_info.retain_size,

   160

		sizeof(retain_info.retain_size),

   161

		retain_info.header_crc);

   162

   163

	retain_info.header_crc = GenerateCRC32Sum(

   164

		&retain_info.hash_size,

   165

		sizeof(retain_info.hash_size),

   166

		retain_info.header_crc);

   167

   168

	retain_info.header_crc = GenerateCRC32Sum(

   169

		retain_info.hash,

   170

		retain_info.hash_size,

   171

		retain_info.header_crc);

   172

}

   173

   174

void CleanupRetain(void)

   175

{

   176

	/* Free hash memory.  */

   177

	free(retain_info.hash);

   178

}

   179

   180

int CheckRetainFile(const char * file)

   181

{

   182

	retain_buffer = fopen(file, "rb");

   183

	if (retain_buffer) {

   184

		/* Check CRC32 and hash.  */

   185

		if (CheckFileCRC(retain_buffer))

   186

			if (CheckFilehash())

   187

				return 1;

   188

		fclose(retain_buffer);

   189

		retain_buffer = NULL;

   190

	}

   191

	return 0;

   192

}

   193

   194

int CheckRetainBuffer(void)

   195

{

   196

	retain_buffer = NULL;

   197

	if (!retain_info.retain_size)

   198

		return 1;

   199

   200

	/* Check latest retain file.  */

   201

	if (CheckRetainFile(rb_file))

   202

		return 1;

   203

   204

	/* Check if we have backup.  */

   205

	if (CheckRetainFile(rb_file_bckp))

   206

		return 1;

   207

   208

	/* We don't have any valid retain buffer - nothing to remind.  */

   209

	return 0;

   210

}

   211

   212

#ifndef FILE_RETAIN_SAVE_PERIOD_S

   213

#define FILE_RETAIN_SAVE_PERIOD_S 1.0

   214

#endif

   215

   216

static double CalcDiffSeconds(IEC_TIME* t1, IEC_TIME *t2)

   217

{

   218

	IEC_TIME dt ={

   219

		t1->tv_sec  - t2->tv_sec,

   220

		t1->tv_nsec - t2->tv_nsec

   221

	};

   222

   223

	if ((dt.tv_nsec < -1000000000) || ((dt.tv_sec > 0) && (dt.tv_nsec < 0))){

   224

		dt.tv_sec--;

   225

		dt.tv_nsec += 1000000000;

   226

	}

   227

	if ((dt.tv_nsec > +1000000000) || ((dt.tv_sec < 0) && (dt.tv_nsec > 0))){

   228

		dt.tv_sec++;

   229

		dt.tv_nsec -= 1000000000;

   230

	}

   231

	return dt.tv_sec + 1e-9*dt.tv_nsec;

   232

}

   233

   234

   235

int RetainSaveNeeded(void)

   236

{

   237

	int ret = 0;

   238

	static IEC_TIME last_save;

   239

	IEC_TIME now;

   240

	double diff_s;

   241

   242

	/* no retain */

   243

	if (!retain_info.retain_size)

   244

		return 0;

   245

   246

	/* periodic retain flush to avoid high I/O load */

   247

	PLC_GetTime(&now);

   248

   249

	diff_s = CalcDiffSeconds(&now, &last_save);

   250

   251

	if ((diff_s > FILE_RETAIN_SAVE_PERIOD_S) || ForceSaveRetainReq()) {

   252

		ret = 1;

   253

		last_save = now;

   254

	}

   255

	return ret;

   256

}

   257

   258

void ValidateRetainBuffer(void)

   259

{

   260

	if (!retain_buffer)

   261

		return;

   262

   263

	/* Add retain data CRC to the end of buffer file.  */

   264

	fseek(retain_buffer, 0, SEEK_END);

   265

	fwrite(&retain_crc, sizeof(retain_crc), 1, retain_buffer);

   266

   267

	/* Sync file buffer and close file.  */

   268

#ifdef __WIN32

   269

	fflush(retain_buffer);

   270

#else

   271

	fsync(fileno(retain_buffer));

   272

#endif

   273

   274

	fclose(retain_buffer);

   275

	retain_buffer = NULL;

   276

}

   277

   278

void InValidateRetainBuffer(void)

   279

{

   280

	if (!RetainSaveNeeded())

   281

		return;

   282

   283

	/* Rename old retain file into *.bak if it exists.  */

   284

	rename(rb_file, rb_file_bckp);

   285

   286

	/* Set file CRC initial value.  */

   287

	retain_crc = retain_info.header_crc;

   288

   289

	/* Create new retain file.  */

   290

	retain_buffer = fopen(rb_file, "wb+");

   291

	if (!retain_buffer) {

   292

		fprintf(stderr, "Failed to create retain file : %s\n", rb_file);

   293

		return;

   294

	}

   295

   296

	/* Write header to the new file.  */

   297

	fwrite(&retain_info.retain_size,

   298

		sizeof(retain_info.retain_size), 1, retain_buffer);

   299

	fwrite(&retain_info.hash_size,

   300

		sizeof(retain_info.hash_size),   1, retain_buffer);

   301

	fwrite(retain_info.hash ,

   302

		sizeof(char), retain_info.hash_size, retain_buffer);

   303

}

   304

   305

void Retain(unsigned int offset, unsigned int count, void *p)

   306

{

   307

	if (!retain_buffer)

   308

		return;

   309

   310

	/* Generate CRC 32 for each data block.  */

   311

	retain_crc = GenerateCRC32Sum(p, count, retain_crc);

   312

   313

	/* Save current var in file.  */

   314

	fseek(retain_buffer, retain_info.header_offset+offset, SEEK_SET);

   315

	fwrite(p, count, 1, retain_buffer);

   316

}

   317

   318

void Remind(unsigned int offset, unsigned int count, void *p)

   319

{

   320

	/* Remind variable from file.  */

   321

	fseek(retain_buffer, retain_info.header_offset+offset, SEEK_SET);

   322

	fread((void *)p, count, 1, retain_buffer);

   323

}

   324

#endif // !HAVE_RETAIN