crc64-iso.c

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <linux/if_alg.h>
#include <string.h>

#define BUFFER_SIZE 4096
#define SECTOR 4096

int main (int argc, char **argv) {

    int desc[2] = { -1, -1 };

    struct sockaddr_alg sock = {
        .salg_family = AF_ALG,
        .salg_type   = "hash",
        .salg_name   = "crc64-iso"
    };

    if ((desc[0] = socket(AF_ALG, SOCK_SEQPACKET, 0)) == -1 ) {
        perror("socket");
        return -1;
    }

    if( bind(desc[0], (struct sockaddr *) &sock, sizeof(sock)) != 0 ) {
        perror("bind");
        return -1;
    }

    if( (desc[1] = accept(desc[0], NULL, 0)) == -1 )
        return -1;

    if (argc != 2 || strlen(argv[1]) == 0) {
        printf("Please specify filename\n");
        return -1; // empty string
    }

    FILE* file;
    unsigned char *buffer;
    if(posix_memalign((void *)&buffer, SECTOR, BUFFER_SIZE)) {
        perror("posix_memalign failed");
        return -1;
    }

    file = fopen(argv[1], "rb");
    if(file == NULL)
    {
        printf("An error occured while opening file: %s\n", argv[1]);
        free(buffer);
        return -1;
    }

    while(!feof(file))
    {
        unsigned int count = fread(buffer, sizeof(char), BUFFER_SIZE, file);
        if(ferror(file))
        {
            printf("An error occurred while accessing the file: %s\n", argv[1]);
            fclose(file);
            free(buffer);
            return -1;
        }

        if (send(desc[1], buffer, count, MSG_MORE) != count) {
            free(buffer);
            return -1;
        }
    }

    long int crc64 = 0x0000000000000000;
    if(read(desc[1], &crc64, 8) != 8) {
        free(buffer);
        return -1;
    }

    printf("0x%llx\n", crc64);
    free(buffer);
    return 0;
}