Add 6th lab

CMakeLists.txt

@@ -17,4 +17,5 @@ define_lab(lab2)
 define_lab(lab3)
 define_lab(lab4)
 define_lab(lab5)
+define_lab(lab6)
 define_lab(lab7)

lab6/.execme

@@ -0,0 +1,77 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+IFS=$'\n\t'
+
+function assert() {
+  local checksum_prg="./lab6_check-$1.c_run"
+  local input=$2
+  local expected=$3
+  local got
+  echo "Testing $1 on string \`"$input"'..."
+  got=$($checksum_prg -q <(printf "%s" "$input"))
+  if diff -q <(echo "$got") <(echo "$expected") > /dev/null; then
+    echo "OK!"
+  else
+    echo "Assertion failed!"
+    echo "Expected: $expected"
+    echo "Got: $got"
+  fi
+}
+
+function run_bench() {
+  local checksum_prg="./lab6_check-$1.c_run"
+
+  echo "Benchmarking $1 with file $2..."
+  $checksum_prg -b "$2"
+}
+
+pushd "$1" > /dev/null
+
+# Checked with https://www.scadacore.com/tools/programming-calculators/online-checksum-calculator/
+
+assert xor "123456789" "0x31"
+assert xor "444444444444444444444444444" "0x34"
+assert xor "4444444444444444444444444444" "0x00"
+assert xor "444444444444444444444444444\n" "0x06"
+assert xor "Test string" "0x03"
+assert xor "Try not to laugh1!%&<>z" "0x0d"
+
+# Checked with https://gchq.github.io/CyberChef/#recipe=Fletcher-16_Checksum()
+
+assert fletcher "44" "0x9c68"
+assert fletcher "Test string" "0x6e5b"
+assert fletcher "4444444444444444444444444444" "0xcab5"
+assert fletcher "444444444444444444444444444\n" "0x3f4c"
+assert fletcher "Try not to laugh1!%&<>z" "0x137c"
+assert fletcher "123456789" "0x1ede"
+
+# Checked with https://emn178.github.io/online-tools/crc16.html
+
+assert crc "123456789" "0xbb3d"
+assert crc "4444444444444444444444444444" "0x5d9d"
+assert crc "Test string" "0x5e4c"
+assert crc "Try not to laugh1!%&<>z" "0x6579"
+assert crc "tEsTTa" "0x0763"
+
+# Big file tests
+
+head -c 128M </dev/urandom >bigfile.bin
+
+run_bench xor bigfile.bin
+run_bench fletcher bigfile.bin
+run_bench crc bigfile.bin
+
+echo "Create & check checksum..."
+head -c 16385 <(yes 4) > testfile.bin
+head -c 32766 <(yes KRIPER2004) >> testfile.bin
+./lab6_create-csum.c_run testfile.bin testfile.bin.crc8maxim
+echo "This should be OK..."
+./lab6_check-csum.c_run testfile.bin testfile.bin.crc8maxim
+
+echo "Spoiling the file..."
+sed 's/4KRIP/HELLO/' testfile.bin > testfile_broken.bin
+echo "This should NOT be OK..."
+./lab6_check-csum.c_run testfile_broken.bin testfile.bin.crc8maxim
+
+popd > /dev/null

lab6/CMakeLists.txt

@@ -0,0 +1,38 @@
+cmake_minimum_required(VERSION 3.16)
+set(CMAKE_C_STANDARD 11)
+
+# Lab name
+set(LAB_NAME "lab6")
+
+# Lab tasks
+list(APPEND SOURCE_FILES
+        check-xor.c
+        check-fletcher.c
+        check-crc.c
+        create-csum.c
+        check-csum.c
+        )
+list(APPEND NON_COMPILABLE_SRC
+        .execme
+        )
+
+### Here goes the template
+
+project("${LAB_NAME}" C)
+
+add_custom_target("${LAB_NAME}")
+
+foreach (file IN LISTS SOURCE_FILES)
+    add_executable("${LAB_NAME}_${file}_run" "${file}")
+    add_dependencies("${LAB_NAME}" "${LAB_NAME}_${file}_run")
+endforeach ()
+
+foreach (file IN LISTS NON_COMPILABLE_SRC)
+    add_custom_command(
+            TARGET "${LAB_NAME}" POST_BUILD
+            DEPENDS "${file}"
+            COMMAND ${CMAKE_COMMAND} -E copy
+            "${CMAKE_CURRENT_SOURCE_DIR}/${file}"
+            "${CMAKE_CURRENT_BINARY_DIR}/${file}"
+    )
+endforeach ()

lab6/README.md

@@ -0,0 +1,3 @@
+# Лабораторная работа №6
+
+## Задание 1

lab6/check-crc.c

@@ -0,0 +1,109 @@
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/time.h>
+
+#define USAGE_STRING "Usage: %s [-q] [-b] [--] [file [file...]]\n"
+#define MAX(a,b) ((a)>(b)?(a):(b))
+#define STR_EQ(a, b) (!strcmp((a),(b)))
+#define FATAL(fmt, ...) do {\
+  fprintf(stderr,fmt,##__VA_ARGS__);\
+  exit(1);\
+} while (0)
+#define WARNING(fmt, ...) fprintf(stderr,fmt,##__VA_ARGS__)
+
+static const uint16_t crc16_tab[256] = {
+    0x0000, 0xc0c1, 0xc181, 0x0140, 0xc301, 0x03c0, 0x0280, 0xc241,
+    0xc601, 0x06c0, 0x0780, 0xc741, 0x0500, 0xc5c1, 0xc481, 0x0440,
+    0xcc01, 0x0cc0, 0x0d80, 0xcd41, 0x0f00, 0xcfc1, 0xce81, 0x0e40,
+    0x0a00, 0xcac1, 0xcb81, 0x0b40, 0xc901, 0x09c0, 0x0880, 0xc841,
+    0xd801, 0x18c0, 0x1980, 0xd941, 0x1b00, 0xdbc1, 0xda81, 0x1a40,
+    0x1e00, 0xdec1, 0xdf81, 0x1f40, 0xdd01, 0x1dc0, 0x1c80, 0xdc41,
+    0x1400, 0xd4c1, 0xd581, 0x1540, 0xd701, 0x17c0, 0x1680, 0xd641,
+    0xd201, 0x12c0, 0x1380, 0xd341, 0x1100, 0xd1c1, 0xd081, 0x1040,
+    0xf001, 0x30c0, 0x3180, 0xf141, 0x3300, 0xf3c1, 0xf281, 0x3240,
+    0x3600, 0xf6c1, 0xf781, 0x3740, 0xf501, 0x35c0, 0x3480, 0xf441,
+    0x3c00, 0xfcc1, 0xfd81, 0x3d40, 0xff01, 0x3fc0, 0x3e80, 0xfe41,
+    0xfa01, 0x3ac0, 0x3b80, 0xfb41, 0x3900, 0xf9c1, 0xf881, 0x3840,
+    0x2800, 0xe8c1, 0xe981, 0x2940, 0xeb01, 0x2bc0, 0x2a80, 0xea41,
+    0xee01, 0x2ec0, 0x2f80, 0xef41, 0x2d00, 0xedc1, 0xec81, 0x2c40,
+    0xe401, 0x24c0, 0x2580, 0xe541, 0x2700, 0xe7c1, 0xe681, 0x2640,
+    0x2200, 0xe2c1, 0xe381, 0x2340, 0xe101, 0x21c0, 0x2080, 0xe041,
+    0xa001, 0x60c0, 0x6180, 0xa141, 0x6300, 0xa3c1, 0xa281, 0x6240,
+    0x6600, 0xa6c1, 0xa781, 0x6740, 0xa501, 0x65c0, 0x6480, 0xa441,
+    0x6c00, 0xacc1, 0xad81, 0x6d40, 0xaf01, 0x6fc0, 0x6e80, 0xae41,
+    0xaa01, 0x6ac0, 0x6b80, 0xab41, 0x6900, 0xa9c1, 0xa881, 0x6840,
+    0x7800, 0xb8c1, 0xb981, 0x7940, 0xbb01, 0x7bc0, 0x7a80, 0xba41,
+    0xbe01, 0x7ec0, 0x7f80, 0xbf41, 0x7d00, 0xbdc1, 0xbc81, 0x7c40,
+    0xb401, 0x74c0, 0x7580, 0xb541, 0x7700, 0xb7c1, 0xb681, 0x7640,
+    0x7200, 0xb2c1, 0xb381, 0x7340, 0xb101, 0x71c0, 0x7080, 0xb041,
+    0x5000, 0x90c1, 0x9181, 0x5140, 0x9301, 0x53c0, 0x5280, 0x9241,
+    0x9601, 0x56c0, 0x5780, 0x9741, 0x5500, 0x95c1, 0x9481, 0x5440,
+    0x9c01, 0x5cc0, 0x5d80, 0x9d41, 0x5f00, 0x9fc1, 0x9e81, 0x5e40,
+    0x5a00, 0x9ac1, 0x9b81, 0x5b40, 0x9901, 0x59c0, 0x5880, 0x9841,
+    0x8801, 0x48c0, 0x4980, 0x8941, 0x4b00, 0x8bc1, 0x8a81, 0x4a40,
+    0x4e00, 0x8ec1, 0x8f81, 0x4f40, 0x8d01, 0x4dc0, 0x4c80, 0x8c41,
+    0x4400, 0x84c1, 0x8581, 0x4540, 0x8701, 0x47c0, 0x4680, 0x8641,
+    0x8201, 0x42c0, 0x4380, 0x8341, 0x4100, 0x81c1, 0x8081, 0x4040
+};
+
+bool flag_end = false;
+bool quiet_mode = false;
+bool benchmark = false;
+
+int main(int argc, char *argv[]) {
+  if (argc == 1) {
+    FATAL(USAGE_STRING, argv[0]);
+  }
+
+  for (int i = 1; i < argc; ++i) {
+    if (!flag_end) {
+      if (argv[i][0] != '-') {
+        flag_end = true;
+      }
+      else if (STR_EQ(argv[i], "--")) {
+        flag_end = true;
+        continue;
+      } else {
+        switch (argv[i][1]) {
+          case 'q':
+            quiet_mode = true;
+            break;
+          case 'b':
+            benchmark = true;
+            break;
+          default:
+            FATAL(USAGE_STRING, argv[0]);
+        }
+        continue;
+      }
+    }
+    FILE *f = fopen(argv[i], "rb");
+    if (f == NULL) {
+      perror("fopen()");
+      FATAL("Could not open %s\n", argv[i]);
+    }
+    struct timeval t0, t1;
+    int c;
+    uint16_t s = 0;
+    gettimeofday(&t0, NULL);
+    while ((c = fgetc(f)) != EOF) {
+      s = crc16_tab[(s ^ (uint8_t) c) & 0xFF] ^ (s >> 8);
+    }
+    gettimeofday(&t1, NULL);
+
+    if (quiet_mode) {
+      printf("0x%04x\n", s);
+    } else {
+      printf("%s: checksum 0x%04x\n", argv[i], s);
+    }
+    if (benchmark) {
+      struct timeval result;
+      timersub(&t1, &t0, &result);
+      printf("CRC execution time: %ld.%06lds\n", result.tv_sec, result.tv_usec);
+    }
+    fclose(f);
+  }
+}

lab6/check-csum.c

@@ -0,0 +1,68 @@
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "crc8.h"
+
+#define USAGE_STRING "Usage: %s <input_file> <checksum_file>\n"
+#define MAX(a,b) ((a)>(b)?(a):(b))
+#define STR_EQ(a, b) (!strcmp((a),(b)))
+#define WARNING(fmt, ...) fprintf(stderr,fmt,##__VA_ARGS__)
+#define FATAL(fmt, ...) do {\
+  WARNING(fmt,##__VA_ARGS__);\
+  exit(1);\
+} while (0)
+
+int main(int argc, char *argv[]) {
+  if (argc != 3) {
+    FATAL(USAGE_STRING, argv[0]);
+  }
+
+  FILE *f = fopen(argv[1], "rb");
+  if (f == NULL) {
+    perror("fopen()");
+    FATAL("Could not open %s\n", argv[1]);
+  }
+
+  FILE *csfile = fopen(argv[2], "rb");
+  if (csfile == NULL) {
+    perror("fopen()");
+    FATAL("Could not open %s\n", argv[2]);
+  }
+
+  int rsize = 0;
+  uint8_t buf[4096] = {0};
+  int blocks_read = 0;
+  uint8_t s;
+  uint8_t block_cs;
+
+  while ((rsize = fread(buf, 1, 4096, f)) == 4096) {
+    s = 0;
+    for (int i = 0; i < 4096; ++i) {
+      CRC8_MAXIM_ITER(s, buf[i]);
+    }
+    if (!fread(&block_cs, 1, 1, csfile)) {
+      FATAL("Unexpected end of checksum file\n");
+    }
+    if (s != block_cs) {
+      WARNING("Checksum mismatch at 4K-block #%d: got 0x%02x, expected 0x%02x\n", blocks_read, s, block_cs);
+    }
+    ++blocks_read;
+  }
+  if (rsize > 0) {
+    s = 0;
+    for (int i = 0; i < rsize; ++i) {
+      CRC8_MAXIM_ITER(s, buf[i]);
+    }
+    if (!fread(&block_cs, 1, 1, csfile)) {
+      FATAL("Unexpected end of checksum file\n");
+    }
+    if (s != block_cs) {
+      WARNING("Checksum mismatch at 4K-block #%d: got 0x%02x, expected 0x%02x\n", blocks_read, s, block_cs);
+    }
+  }
+
+  fclose(f);
+  fclose(csfile);
+}

lab6/check-fletcher.c

@@ -0,0 +1,77 @@
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/time.h>
+
+#define USAGE_STRING "Usage: %s [-q] [-b] [--] [file [file...]]\n"
+#define MAX(a,b) ((a)>(b)?(a):(b))
+#define STR_EQ(a, b) (!strcmp((a),(b)))
+#define FATAL(fmt, ...) do {\
+  fprintf(stderr,fmt,##__VA_ARGS__);\
+  exit(1);\
+} while (0)
+#define WARNING(fmt, ...) fprintf(stderr,fmt,##__VA_ARGS__)
+
+bool flag_end = false;
+bool quiet_mode = false;
+bool benchmark = false;
+
+int main(int argc, char *argv[]) {
+  if (argc == 1) {
+    FATAL(USAGE_STRING, argv[0]);
+  }
+
+  for (int i = 1; i < argc; ++i) {
+    if (!flag_end) {
+      if (argv[i][0] != '-') {
+        flag_end = true;
+      }
+      else if (STR_EQ(argv[i], "--")) {
+        flag_end = true;
+        continue;
+      } else {
+        switch (argv[i][1]) {
+          case 'q':
+            quiet_mode = true;
+            break;
+          case 'b':
+            benchmark = true;
+            break;
+          default:
+            FATAL(USAGE_STRING, argv[0]);
+        }
+        continue;
+      }
+    }
+    FILE *f = fopen(argv[i], "rb");
+    if (f == NULL) {
+      perror("fopen()");
+      FATAL("Could not open %s\n", argv[i]);
+    }
+    struct timeval t0, t1;
+    int c;
+    uint16_t s1 = 0, s2 = 0, s;
+    gettimeofday(&t0, NULL);
+    while ((c = fgetc(f)) != EOF) {
+      s1 = (s1 + (uint8_t) c) % 255;
+      s2 = (s2 + s1) % 255;
+    }
+    s = (s2 << 8) | s1;
+    gettimeofday(&t1, NULL);
+
+    if (quiet_mode) {
+      printf("0x%04x\n", s);
+    } else {
+      printf("%s: checksum 0x%04x\n", argv[i], s);
+    }
+
+    if (benchmark) {
+      struct timeval result;
+      timersub(&t1, &t0, &result);
+      printf("Fletcher execution time: %ld.%06lds\n", result.tv_sec, result.tv_usec);
+    }
+    fclose(f);
+  }
+}

lab6/check-xor.c

@@ -0,0 +1,74 @@
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/time.h>
+
+#define USAGE_STRING "Usage: %s [-q] [-b] [--] [file [file...]]\n"
+#define MAX(a,b) ((a)>(b)?(a):(b))
+#define STR_EQ(a, b) (!strcmp((a),(b)))
+#define FATAL(fmt, ...) do {\
+  fprintf(stderr,fmt,##__VA_ARGS__);\
+  exit(1);\
+} while (0)
+#define WARNING(fmt, ...) fprintf(stderr,fmt,##__VA_ARGS__)
+
+bool flag_end = false;
+bool quiet_mode = false;
+bool benchmark = false;
+
+int main(int argc, char *argv[]) {
+  if (argc == 1) {
+    FATAL(USAGE_STRING, argv[0]);
+  }
+
+  for (int i = 1; i < argc; ++i) {
+    if (!flag_end) {
+      if (argv[i][0] != '-') {
+        flag_end = true;
+      }
+      else if (STR_EQ(argv[i], "--")) {
+        flag_end = true;
+        continue;
+      } else {
+        switch (argv[i][1]) {
+          case 'q':
+            quiet_mode = true;
+            break;
+          case 'b':
+            benchmark = true;
+            break;
+          default:
+            FATAL(USAGE_STRING, argv[0]);
+        }
+        continue;
+      }
+    }
+    FILE *f = fopen(argv[i], "rb");
+    if (f == NULL) {
+      perror("fopen()");
+      FATAL("Could not open %s\n", argv[i]);
+    }
+    struct timeval t0, t1;
+    int c;
+    uint8_t s = 0;
+    gettimeofday(&t0, NULL);
+    while ((c = fgetc(f)) != EOF) {
+      s ^= (uint8_t) c;
+    }
+    gettimeofday(&t1, NULL);
+
+    if (quiet_mode) {
+      printf("0x%02x\n", s);
+    } else {
+      printf("%s: checksum 0x%02x\n", argv[i], s);
+    }
+    if (benchmark) {
+      struct timeval result;
+      timersub(&t1, &t0, &result);
+      printf("XOR execution time: %ld.%06lds\n", result.tv_sec, result.tv_usec);
+    }
+    fclose(f);
+  }
+}

lab6/crc8.h

@@ -0,0 +1,42 @@
+#pragma once
+#include <stdint.h>
+
+static const uint8_t crc8_maxim_table[256] = {
+    0x00, 0x31, 0x62, 0x53, 0xC4, 0xF5, 0xA6, 0x97,
+    0xB9, 0x88, 0xDB, 0xEA, 0x7D, 0x4C, 0x1F, 0x2E,
+    0x43, 0x72, 0x21, 0x10, 0x87, 0xB6, 0xE5, 0xD4,
+    0xFA, 0xCB, 0x98, 0xA9, 0x3E, 0x0F, 0x5C, 0x6D,
+    0x86, 0xB7, 0xE4, 0xD5, 0x42, 0x73, 0x20, 0x11,
+    0x3F, 0x0E, 0x5D, 0x6C, 0xFB, 0xCA, 0x99, 0xA8,
+    0xC5, 0xF4, 0xA7, 0x96, 0x01, 0x30, 0x63, 0x52,
+    0x7C, 0x4D, 0x1E, 0x2F, 0xB8, 0x89, 0xDA, 0xEB,
+    0x3D, 0x0C, 0x5F, 0x6E, 0xF9, 0xC8, 0x9B, 0xAA,
+    0x84, 0xB5, 0xE6, 0xD7, 0x40, 0x71, 0x22, 0x13,
+    0x7E, 0x4F, 0x1C, 0x2D, 0xBA, 0x8B, 0xD8, 0xE9,
+    0xC7, 0xF6, 0xA5, 0x94, 0x03, 0x32, 0x61, 0x50,
+    0xBB, 0x8A, 0xD9, 0xE8, 0x7F, 0x4E, 0x1D, 0x2C,
+    0x02, 0x33, 0x60, 0x51, 0xC6, 0xF7, 0xA4, 0x95,
+    0xF8, 0xC9, 0x9A, 0xAB, 0x3C, 0x0D, 0x5E, 0x6F,
+    0x41, 0x70, 0x23, 0x12, 0x85, 0xB4, 0xE7, 0xD6,
+    0x7A, 0x4B, 0x18, 0x29, 0xBE, 0x8F, 0xDC, 0xED,
+    0xC3, 0xF2, 0xA1, 0x90, 0x07, 0x36, 0x65, 0x54,
+    0x39, 0x08, 0x5B, 0x6A, 0xFD, 0xCC, 0x9F, 0xAE,
+    0x80, 0xB1, 0xE2, 0xD3, 0x44, 0x75, 0x26, 0x17,
+    0xFC, 0xCD, 0x9E, 0xAF, 0x38, 0x09, 0x5A, 0x6B,
+    0x45, 0x74, 0x27, 0x16, 0x81, 0xB0, 0xE3, 0xD2,
+    0xBF, 0x8E, 0xDD, 0xEC, 0x7B, 0x4A, 0x19, 0x28,
+    0x06, 0x37, 0x64, 0x55, 0xC2, 0xF3, 0xA0, 0x91,
+    0x47, 0x76, 0x25, 0x14, 0x83, 0xB2, 0xE1, 0xD0,
+    0xFE, 0xCF, 0x9C, 0xAD, 0x3A, 0x0B, 0x58, 0x69,
+    0x04, 0x35, 0x66, 0x57, 0xC0, 0xF1, 0xA2, 0x93,
+    0xBD, 0x8C, 0xDF, 0xEE, 0x79, 0x48, 0x1B, 0x2A,
+    0xC1, 0xF0, 0xA3, 0x92, 0x05, 0x34, 0x67, 0x56,
+    0x78, 0x49, 0x1A, 0x2B, 0xBC, 0x8D, 0xDE, 0xEF,
+    0x82, 0xB3, 0xE0, 0xD1, 0x46, 0x77, 0x24, 0x15,
+    0x3B, 0x0A, 0x59, 0x68, 0xFF, 0xCE, 0x9D, 0xAC
+};
+
+#define CRC8_MAXIM_ITER(crc, chr) \
+  do { \
+    (crc) = crc8_maxim_table[(crc) ^ (chr)]; \
+  } while (0)

lab6/create-csum.c

@@ -0,0 +1,55 @@
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "crc8.h"
+
+#define USAGE_STRING "Usage: %s <input_file> <output_file>\n"
+#define MAX(a,b) ((a)>(b)?(a):(b))
+#define STR_EQ(a, b) (!strcmp((a),(b)))
+#define FATAL(fmt, ...) do {\
+  fprintf(stderr,fmt,##__VA_ARGS__);\
+  exit(1);\
+} while (0)
+#define WARNING(fmt, ...) fprintf(stderr,fmt,##__VA_ARGS__)
+
+int main(int argc, char *argv[]) {
+  if (argc != 3) {
+    FATAL(USAGE_STRING, argv[0]);
+  }
+
+  FILE *f = fopen(argv[1], "rb");
+  if (f == NULL) {
+    perror("fopen()");
+    FATAL("Could not open %s\n", argv[1]);
+  }
+
+  FILE *fw = fopen(argv[2], "wb");
+  if (fw == NULL) {
+    perror("fopen()");
+    FATAL("Could not open %s\n", argv[2]);
+  }
+
+  int rsize = 0;
+  uint8_t buf[4096] = {0};
+  uint8_t s;
+
+  while ((rsize = fread(buf, 1, 4096, f)) == 4096) {
+    s = 0;
+    for (int i = 0; i < 4096; ++i) {
+      CRC8_MAXIM_ITER(s, buf[i]);
+    }
+    fwrite(&s, 1, 1, fw);
+  }
+  if (rsize > 0) {
+    s = 0;
+    for (int i = 0; i < rsize; ++i) {
+      CRC8_MAXIM_ITER(s, buf[i]);
+    }
+    fwrite(&s, 1, 1, fw);
+  }
+
+  fclose(f);
+  fclose(fw);
+}