[WIP] First part of the CRC, currently not working

client/include/crc32.h

@@ -3,7 +3,7 @@
 
 #include <stdint.h>
 #include <stdlib.h>
-
+#include "fraction.h"
 extern const uint32_t crc32_tab[];
 /*
  * A function that calculates the CRC-32 based on the table above is
@@ -12,5 +12,4 @@ extern const uint32_t crc32_tab[];
  * in sys/libkern.h, where it can be inlined.
  */
 uint32_t crc32(const void *buf, size_t size);
-
 #endif // CRC32_H

client/include/fraction.h

@@ -22,9 +22,10 @@ typedef struct {
 } fraction_t;
 
 int download_fraction(int sfd, char *url, fraction_t *fraction);
-int fraction_parse(char *data, size_t size, fraction_t *fraction); 
+int fraction_parse(char *data, size_t size, fraction_t *fraction);
 int check_magic(uint32_t data);
 void print_fraction(fraction_t fraction);
 void fraction_free(fraction_t *fraction);
 int compare_fractions(const void* a, const void* b);
+void check_fractions(fraction_t *fraction, size_t size);
 #endif

client/src/crc32.c

@@ -1,4 +1,5 @@
 #include "../include/crc32.h"
+#include "../include/fraction.h"
 
 const uint32_t crc32_tab[] = {
     0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
@@ -54,3 +55,4 @@ uint32_t crc32(const void *buf, size_t size) {
     crc = crc32_tab[(crc ^ *p++) & 0xFF] ^ (crc >> 8);
   return crc ^ ~0U;
 }
+

client/src/fraction.c

@@ -1,6 +1,6 @@
 #include "../include/fraction.h"
 #include <stdint.h>
-
+#include "../include/crc32.h"
 
 // Change the return type to int to indicate success or failure
 int download_fraction(int sfd, char *url, fraction_t *fraction) {
@@ -109,9 +109,52 @@ void print_fraction(fraction_t fraction) {
   printf("\n\n");
 }
 
+uint32_t calc_crc(fraction_t *frac){
+
+    uint8_t buffer[sizeof(frac->magic) + sizeof(frac->index) + sizeof(frac->iv) + strlen(frac->data)];
+    size_t offset = 0;
+
+    memcpy(buffer + offset, &frac->magic, sizeof(frac->magic));
+    offset += sizeof(frac->magic);
+
+    memcpy(buffer + offset, &frac->index, sizeof(frac->index));
+    offset += sizeof(frac->index);
+
+    memcpy(buffer + offset, frac->iv, sizeof(frac->iv));
+    offset += sizeof(frac->iv);
+
+    memcpy(buffer + offset, frac->data, strlen(frac->data));
+    offset += strlen(frac->data);
+
+    uint32_t calculated_crc = crc32(buffer, offset);
+
+    if (calculated_crc == frac->crc) {
+        printf("Checksum correcto\n");
+    } else {
+        printf("Checksum incorrecto\n");
+        printf("Checksum generado: %08X\n", calculated_crc);
+        printf("Checksum que deberia ser: %08X\n", frac->crc);
+    }
+
+  return calculated_crc == frac->crc;
+}
+
+void check_fractions(fraction_t *fraction, size_t size){
+
+  for(size_t i = 0; i < size; i++){
+    if(calc_crc(&fraction[i])){
+      puts("checksum is correct");
+    } else{
+      puts("Checksum incorrect");
+    }
+  }
+}
+
 void fraction_free(fraction_t *fraction) {
   free(fraction->data);
   fraction->magic = 0;
   fraction->index = 0;
   fraction->crc = 0;
 }
+
+

client/src/main.c

@@ -15,7 +15,7 @@ int main(void) {
   struct addrinfo hints, *ainfo;
   int sfd; // socket file descriptor
   http_res_t http_fraction_res, http_post_res;
-
+  size_t size = 0;
   /* Setup socket and initiate connection with the server */
   setup_hints(&hints);
 
@@ -76,6 +76,7 @@ int main(void) {
   qsort(fractions, lines_read, sizeof(fraction_t), compare_fractions);
   for (int i = 0; i < lines_read; i++) {
     print_fraction(fractions[i]);
+    size++;
   }
 
   /* Notify the server that we successfully downloaded the fractions */
@@ -88,6 +89,9 @@ int main(void) {
     goto cleanup_socket;
   }
 
+  check_fractions(fractions,size);
+
+
   /* Cleanup */
   http_free(&http_fraction_res);
   http_free(&http_post_res);
@@ -103,6 +107,9 @@ int main(void) {
   close(sfd);
   return EXIT_SUCCESS;
 
+
+
+
 cleanup_socket:
   close(sfd);
   return EXIT_FAILURE;