/****************************
    file: count.c

    Written by Keith Oxenrider October 25, 1998

    For use on the web as a cgi program.  Is activated by
    calling the program as an image, i.e., IMG SRC="/cgi-bin/count.cgi?countdatafile".
    to increment counter without having a visible display, invoke as follows:
        IMG SRC="/cgi-bin/count.cgi?countdatafile" HEIGHT="0" WIDTH="0"

    If the last character in the input string is an '!'
       then the counter will not be incremented, just displayed.

    The program will automagically create a new count file if the
    filename selected does not exist.

    There is a companion program called 'view_counts' that is used
    to look at all the counter stored along with the last access time.

    Modified to include date/time stamp on 3/1/1999.
    Security fix on 11/18/2003 to eliminate directory transversals.


****************************/

#include <ctype.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#define TRUE 1
#define FALSE 0
#define MAXLINELENGTH 1024

/* hardcoded path to directory that contains data files */
#ifdef WIN32
    char m_strPath[] = "countdata\\";
#else /* presumed *nix */
    char m_strPath[] = "countdata/";
#endif

char *digits[] ={
   "0xff","0xff","0xff","0xc3","0x99","0x99","0x99","0x99",
   "0x99","0x99","0x99","0x99","0xc3","0xff","0xff","0xff",
   "0xff","0xff","0xff","0xcf","0xc7","0xcf","0xcf","0xcf",
   "0xcf","0xcf","0xcf","0xcf","0xcf","0xff","0xff","0xff",
   "0xff","0xff","0xff","0xc3","0x99","0x9f","0x9f","0xcf",
   "0xe7","0xf3","0xf9","0xf9","0x81","0xff","0xff","0xff",
   "0xff","0xff","0xff","0xc3","0x99","0x9f","0x9f","0xc7",
   "0x9f","0x9f","0x9f","0x99","0xc3","0xff","0xff","0xff",
   "0xff","0xff","0xff","0xcf","0xcf","0xc7","0xc7","0xcb",
   "0xcb","0xcd","0x81","0xcf","0x87","0xff","0xff","0xff",
   "0xff","0xff","0xff","0x81","0xf9","0xf9","0xf9","0xc1",
   "0x9f","0x9f","0x9f","0x99","0xc3","0xff","0xff","0xff",
   "0xff","0xff","0xff","0xc7","0xf3","0xf9","0xf9","0xc1",
   "0x99","0x99","0x99","0x99","0xc3","0xff","0xff","0xff",
   "0xff","0xff","0xff","0x81","0x99","0x9f","0x9f","0xcf",
   "0xcf","0xe7","0xe7","0xf3","0xf3","0xff","0xff","0xff",
   "0xff","0xff","0xff","0xc3","0x99","0x99","0x99","0xc3",
   "0x99","0x99","0x99","0x99","0xc3","0xff","0xff","0xff",
   "0xff","0xff","0xff","0xc3","0x99","0x99","0x99","0x99",
   "0x83","0x9f","0x9f","0xcf","0xe3","0xff","0xff","0xff"
};

/* this will display all zeros in the event that an error is found
   if you get all zeros, there is a bug either in the code or in the 
   parameters given */
void dumpDigits(const char * number){
    int len = strlen(number);
    char cc[] = "0";
    int  x, y, c;

    printf ("Content-type: image/x-xbitmap\n\n");

    printf ("#define count_width %d\n", len * 8);
    printf ("#define count_height 16\n");
    printf ("static char count_bits[] = {\n");

    for (x=0; x<16; x++){
        for (y=0; y<len; y++){
            cc[0] = number[y];
            c = atoi(cc);
            printf(digits[((c*16)+x)]);
            if (y<len-1) printf(", ");
        }
        if (x==15) 
            printf("};");
        printf(",\n");
    }
    printf("\n");
    exit(0);
}

/************************
 *
 *  main()
 *
 ************************/

int main () {
    unsigned long count;
    FILE *fin = NULL;
    char numb[MAXLINELENGTH], *input;
    int len, i, write, wipe;
    char filename[MAXLINELENGTH];
    struct tm *time_date;
    time_t timer;

    input = getenv("QUERY_STRING");

    if (input == NULL){/* no file for counts */
        dumpDigits("0000000000");
        return 0;
    }

    len = strlen(input);
    /*if input is too high, something is wrong, exit*/
    if (len >= MAXLINELENGTH){
        dumpDigits("0000000000");
        return 0;
    }

   /*check for invalid characters (thanks infamous42md!)*/
    for (i=0; i<len; i++){
        /*only allow alpha characters, could add numeric if you want*/
        if (!isalpha(input[i])){
            if (input[i] != '!'){
                dumpDigits("0000000000");
                return 0;
            }
        }
    }

   /*check for write flag on end of filename and set accordingly*/
    write = TRUE;
    if (input[len-1] == '!'){
        write = FALSE;
        input[len-1] = '\0';
    }

    strncpy(filename, m_strPath, MAXLINELENGTH);
    strncat(filename, input, MAXLINELENGTH);

    numb[0] = '\0';

    /*open the file that holds numeric counter value*/
    if ((fin = fopen(filename, "r")) == NULL)
        strcpy(numb, "0");
    else{
        fgets(numb, MAXLINELENGTH, fin);
        fclose(fin);
    }

    i = 0; /* stick a NULL after what is supposed to be the count */
    while (numb[i] != ' ' && numb[i] != '\0')
        i++;
    numb[i] = '\0';

    len = strlen(numb);

    /* if contents of counter file are not recognizable input, set counter to zero */
    wipe = FALSE;
    for (i=0; i<len; i++){
        if (!isdigit(numb[i]))
            wipe = TRUE;
        if (i>10) /* hard-coded for 10 digits, must change if you want more */
            wipe = TRUE;
        if (wipe){
            strcpy(numb, "0");
            break;
        }
    }

    count = atol(numb);

    if (count >= LONG_MAX)/*if the value rolls over, reset to zero*/
        count = 0;

    if (write){/* write new counter data to file */
        count++;
        fin = fopen(filename, "w");
        if (fin){
            fprintf(fin, "%ld", count);
            /* get the time and format to look nice*/
            time(&timer);
            time_date = localtime(&timer);
            fprintf(fin, " %02d/%02d/%d %02d:%02d:%02d", time_date->tm_mon +1, time_date->tm_mday, time_date->tm_year+1900, time_date->tm_hour, time_date->tm_min, time_date->tm_sec);
            fclose(fin);
        }else{
            dumpDigits("0000000000");
        }
    }

    sprintf(numb, "%ld", count);
    dumpDigits(numb);

    /* should never get here, exit is called from dumpDigits() */
    return 1;

}/* end main */