kernel mem reader

kmem_reader.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <mach/mach_traps.h>
#include <mach/mach_init.h>
#include <mach/mach_error.h>

void hexToBytes(const char* hex, uint8_t** buffer, size_t* bytes) {
    *bytes = strlen(hex) / 2;
    *buffer = (uint8_t*) malloc(*bytes);
    size_t i;
    for(i = 0; i < *bytes; i++) {
        uint32_t byte;
        sscanf(hex, "%02x", &byte);
        (*buffer)[i] = byte;
        hex += 2;
    }
}

void bytesToHex(const uint8_t* buffer, size_t bytes, int base_addr) {
    size_t i;
    char *p_text;
    p_text = malloc(17);
    while(bytes > 0) {
        memset(p_text, 0, 17);
        printf("0x%x: ", base_addr);
        for(i=0;i<16 && bytes>0;i++)
        {
            if(isalnum(*buffer))
                p_text[i] = *buffer;
            else
                p_text[i]='.';
            printf("%02x ", *buffer);
            buffer++;
            bytes--;
        }
        printf("\t%s", p_text);
        printf("\n");
        base_addr+=16;
    }
}
int main(int argc, char* argv[])
{
    FILE *fp;
    pointer_t buf;
    unsigned int sz, bytes, i;
    static mach_port_t kernel_task;

    vm_address_t addr = 0x80002000;
    bytes = 2048;

    if(argc<2)
    {
        fprintf(stderr, "usage: %s addr [bytes]\n", argv[0]);
        return 0;
    }
    else if(argc==3)
        sscanf(argv[2], "%d", &bytes);
    sscanf(argv[1], "%x", &addr);

    printf("addr:%x bytes:%d\n", (uint32_t) addr, bytes);

    kern_return_t error = task_for_pid(mach_task_self(), 0, &kernel_task);
    printf("-> %x [%d - %s]\n",  kernel_task, error, mach_error_string(error));

    fp= fopen("/tmp/gotu", "w");
    for(i=0;i<bytes;i+=16)
    {
        vm_read(kernel_task, addr+i, 16, &buf, &sz);
        bytesToHex(buf, sz, addr+i);
        fwrite((void *)buf, 1, sz, fp);
    }
    fclose(fp);
}