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 /* Retain header struct.  */

    26 struct retain_info_t {

    27     uint32_t retain_size;

    28     uint32_t hash_size;

    29     uint8_t *hash;

    30     uint32_t header_offset;

    31     uint32_t header_crc;

    32 };

    33 

    34 /* Init retain info structure.  */

    35 struct retain_info_t retain_info;

    36 

    37 /* CRC lookup table and initial state.  */

    38 static const uint32_t crc32_table[256] = {

    39     0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F,

    40         0xE963A535, 0x9E6495A3,

    41     0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD,

    42         0xE7B82D07, 0x90BF1D91,

    43     0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB,

    44         0xF4D4B551, 0x83D385C7,

    45     0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9,

    46         0xFA0F3D63, 0x8D080DF5,

    47     0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172, 0x3C03E4D1, 0x4B04D447,

    48         0xD20D85FD, 0xA50AB56B,

    49     0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75,

    50         0xDCD60DCF, 0xABD13D59,

    51     0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423,

    52         0xCFBA9599, 0xB8BDA50F,

    53     0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11,

    54         0xC1611DAB, 0xB6662D3D,

    55     0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F,

    56         0x9FBFE4A5, 0xE8B8D433,

    57     0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D,

    58         0x91646C97, 0xE6635C01,

    59     0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, 0x1B01A57B,

    60         0x8208F4C1, 0xF50FC457,

    61     0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49,

    62         0x8CD37CF3, 0xFBD44C65,

    63     0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7,

    64         0xA4D1C46D, 0xD3D6F4FB,

    65     0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5,

    66         0xAA0A4C5F, 0xDD0D7CC9,

    67     0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3,

    68         0xB966D409, 0xCE61E49F,

    69     0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81,

    70         0xB7BD5C3B, 0xC0BA6CAD,

    71     0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF,

    72         0x04DB2615, 0x73DC1683,

    73     0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D,

    74         0x0A00AE27, 0x7D079EB1,

    75     0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB,

    76         0x196C3671, 0x6E6B06E7,

    77     0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9,

    78         0x17B7BE43, 0x60B08ED5,

    79     0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767,

    80         0x3FB506DD, 0x48B2364B,

    81     0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55,

    82         0x316E8EEF, 0x4669BE79,

    83     0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703,

    84         0x220216B9, 0x5505262F,

    85     0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31,

    86         0x2CD99E8B, 0x5BDEAE1D,

    87     0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F,

    88         0x72076785, 0x05005713,

    89     0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D,

    90         0x7CDCEFB7, 0x0BDBDF21,

    91     0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B,

    92         0x6FB077E1, 0x18B74777,

    93     0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69,

    94         0x616BFFD3, 0x166CCF45,

    95     0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7,

    96         0x4969474D, 0x3E6E77DB,

    97     0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5,

    98         0x47B2CF7F, 0x30B5FFE9,

    99     0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693,

   100         0x54DE5729, 0x23D967BF,

   101     0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1,

   102         0x5A05DF1B, 0x2D02EF8D,

   103 };

   104 

   105 uint32_t retain_crc;

   106 

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

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

   109 {

   110     uint32_t crc = ~init;

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

   112     while (len--)

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

   114     return ~crc;

   115 }

   116 

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

   118 int CheckFileCRC(FILE * file_buffer)

   119 {

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

   121     const uint32_t magic_number = 0x2144df1c;

   122 

   123     /* CRC initial state.  */

   124     uint32_t calc_crc32 = 0;

   125     char data_block = 0;

   126 

   127     while (!feof(file_buffer)) {

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

   129             calc_crc32 =

   130                 GenerateCRC32Sum(&data_block, sizeof(char), calc_crc32);

   131     }

   132 

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

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

   135 }

   136 

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

   138 int CheckFilehash(void)

   139 {

   140     int k, ret;

   141     int offset = sizeof(retain_info.retain_size);

   142 

   143     rewind(retain_buffer);

   144     fseek(retain_buffer, offset, SEEK_SET);

   145 

   146     uint32_t size;

   147     ret = fread(&size, sizeof(size), 1, retain_buffer);

   148     if (size != retain_info.hash_size)

   149         return 0;

   150 

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

   152         uint8_t file_digit;

   153         ret = fread(&file_digit, sizeof(char), 1, retain_buffer);

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

   155             return 0;

   156     }

   157 

   158     return 1;

   159 }

   160 

   161 void InitRetain(void)

   162 {

   163     int i;

   164 

   165     /* Get retain size in bytes */

   166     retain_info.retain_size = GetRetainSize();

   167 

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

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

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

   171     //retain_info.hash_size = 0;

   172     retain_info.hash = malloc(retain_info.hash_size);

   173 

   174     /* Transform hash string into byte sequence.  */

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

   176         int byte = 0;

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

   178         retain_info.hash[i] = byte;

   179     }

   180 

   181     /* Calc header offset.  */

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

   183         sizeof(retain_info.hash_size) + retain_info.hash_size;

   184 

   185     /*  Set header CRC initial state.  */

   186     retain_info.header_crc = 0;

   187 

   188     /* Calc crc for header.  */

   189     retain_info.header_crc = GenerateCRC32Sum(&retain_info.retain_size,

   190                                               sizeof(retain_info.retain_size),

   191                                               retain_info.header_crc);

   192 

   193     retain_info.header_crc = GenerateCRC32Sum(&retain_info.hash_size,

   194                                               sizeof(retain_info.hash_size),

   195                                               retain_info.header_crc);

   196 

   197     retain_info.header_crc = GenerateCRC32Sum(retain_info.hash,

   198                                               retain_info.hash_size,

   199                                               retain_info.header_crc);

   200 }

   201 

   202 void CleanupRetain(void)

   203 {

   204     /* Free hash memory.  */

   205     free(retain_info.hash);

   206 }

   207 

   208 int CheckRetainFile(const char *file)

   209 {

   210     retain_buffer = fopen(file, "rb");

   211     if (retain_buffer) {

   212         /* Check CRC32 and hash.  */

   213         if (CheckFileCRC(retain_buffer))

   214             if (CheckFilehash())

   215                 return 1;

   216         fclose(retain_buffer);

   217         retain_buffer = NULL;

   218     }

   219     return 0;

   220 }

   221 

   222 int CheckRetainBuffer(void)

   223 {

   224     retain_buffer = NULL;

   225     if (!retain_info.retain_size)

   226         return 1;

   227 

   228     /* Check latest retain file.  */

   229     if (CheckRetainFile(rb_file))

   230         return 1;

   231 

   232     /* Check if we have backup.  */

   233     if (CheckRetainFile(rb_file_bckp))

   234         return 1;

   235 

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

   237     return 0;

   238 }

   239 

   240 #ifndef FILE_RETAIN_SAVE_PERIOD_S

   241 #define FILE_RETAIN_SAVE_PERIOD_S 1.0

   242 #endif

   243 

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

   245 {

   246     IEC_TIME dt = {

   247         t1->tv_sec - t2->tv_sec,

   248         t1->tv_nsec - t2->tv_nsec

   249     };

   250 

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

   252         dt.tv_sec--;

   253         dt.tv_nsec += 1000000000;

   254     }

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

   256         dt.tv_sec++;

   257         dt.tv_nsec -= 1000000000;

   258     }

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

   260 }

   261 

   262 int RetainSaveNeeded(void)

   263 {

   264     int ret = 0;

   265     static IEC_TIME last_save;

   266     IEC_TIME now;

   267     double diff_s;

   268 

   269     /* no retain */

   270     if (!retain_info.retain_size)

   271         return 0;

   272 

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

   274     PLC_GetTime(&now);

   275 

   276     diff_s = CalcDiffSeconds(&now, &last_save);

   277 

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

   279         ret = 1;

   280         last_save = now;

   281     }

   282     return ret;

   283 }

   284 

   285 void ValidateRetainBuffer(void)

   286 {

   287     if (!retain_buffer)

   288         return;

   289 

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

   291     fseek(retain_buffer, 0, SEEK_END);

   292     fwrite(&retain_crc, sizeof(uint32_t), 1, retain_buffer);

   293 

   294     /* Sync file buffer and close file.  */

   295 #ifdef __WIN32

   296     fflush(retain_buffer);

   297 #else

   298     fsync(fileno(retain_buffer));

   299 #endif

   300 

   301     fclose(retain_buffer);

   302     retain_buffer = NULL;

   303 }

   304 

   305 void InValidateRetainBuffer(void)

   306 {

   307     if (!RetainSaveNeeded())

   308         return;

   309 

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

   311     rename(rb_file, rb_file_bckp);

   312 

   313     /* Set file CRC initial value.  */

   314     retain_crc = retain_info.header_crc;

   315 

   316     /* Create new retain file.  */

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

   318     if (!retain_buffer) {

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

   320         return;

   321     }

   322 

   323     /* Write header to the new file.  */

   324     fwrite(&retain_info.retain_size,

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

   326     fwrite(&retain_info.hash_size,

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

   328     fwrite(retain_info.hash,

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

   330 }

   331 

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

   333 {

   334     if (!retain_buffer)

   335         return;

   336 

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

   338     retain_crc = GenerateCRC32Sum(p, count, retain_crc);

   339 

   340     /* Save current var in file.  */

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

   342     fwrite(p, count, 1, retain_buffer);

   343 }

   344 

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

   346 {

   347     int ret;

   348     /* Remind variable from file.  */

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

   350     ret = fread((void *)p, count, 1, retain_buffer);

   351 }

   352 #endif                          // !HAVE_RETAIN