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/*
 * (c) Copyright 1990 Conor P. Cahill (uunet!virtech!cpcahil).
 * You may copy, distribute, and use this software as long as this
 * copyright statement is not removed.
 */

#include <stdio.h>
#include "malloc.h"
#include "debug.h"

#ifndef lint
static
char rcs_hdr[] = "$Id: mlc_chk.c,v 1.2 2006-07-25 10:09:34 rt Exp $";
#endif

extern struct mlist   malloc_start;
extern struct mlist * malloc_end;
extern char     * malloc_data_start;
extern char     * malloc_data_end;

/*
 * Function:    malloc_in_arena()
 *
 * Purpose: to verify address is within malloc arena.
 *
 * Arguments:   ptr - pointer to verify
 *
 * Returns: TRUE    - if pointer is within malloc area
 *      FALSE   - otherwise
 *
 * Narrative:
 *   IF pointer is >= malloc area start AND <= malloc area end
 *      return TRUE
 *   ELSE
 *      return FALSE
 *
 * Mod History:
 *   90/01/24   cpcahil     Initial revision.
 */
int
malloc_in_arena(ptr)
    char    * ptr;
{
    extern char * malloc_data_start;
    extern char * malloc_data_end;
    int       rtn = 0;

    if( ptr >= malloc_data_start && ptr <= malloc_data_end )
    {
        rtn = 1;
    }

    return(rtn);
}

/*
 * Function:    malloc_check_str()
 *
 * Arguments:   func    - name of function calling this routine
 *      str - pointer to area to check
 *
 * Purpose: to verify that if str is within the malloc arena, the data
 *      it points to does not extend beyond the applicable region.
 *
 * Returns: Nothing of any use (function is void).
 *
 * Narrative:
 *   IF pointer is within malloc arena
 *      determin length of string
 *      call malloc_verify() to verify data is withing applicable region
 *   return
 *
 * Mod History:
 *   90/01/24   cpcahil     Initial revision.
 *   90/01/29   cpcahil     Added code to ignore recursive calls.
 */
void
malloc_check_str(func,str)
    char        * func;
    char        * str;
{
    static int    layers;
    register char   * s;

    if( (layers++ == 0) &&  malloc_in_arena(str) )
    {
        for( s=str; *s; s++)
        {
        }

        malloc_verify(func,str,s-str+1);
    }

    layers--;
}

/*
 * Function:    malloc_check_strn()
 *
 * Arguments:   func    - name of function calling this routine
 *      str - pointer to area to check
 *      len     - max length of string
 *
 * Purpose: to verify that if str is within the malloc arena, the data
 *      it points to does not extend beyond the applicable region.
 *
 * Returns: Nothing of any use (function is void).
 *
 * Narrative:
 *   IF pointer is within malloc arena
 *      determin length of string
 *      call malloc_verify() to verify data is withing applicable region
 *   return
 *
 * Mod History:
 *   90/01/24   cpcahil     Initial revision.
 *   90/01/29   cpcahil     Added code to ignore recursive calls.
 *   90/08/29   cpcahil     added length (for strn* functions)
 */
void
malloc_check_strn(func,str,len)
    char        * func;
    char        * str;
    int       len;
{
    register int      i;<--- The scope of the variable 'i' can be reduced
    static int    layers;
    register char   * s;

    if( (layers++ == 0) &&  malloc_in_arena(str) )
    {
        for( s=str,i=0; (i < len) && *s; s++)
        {
        }

        malloc_verify(func,str,s-str+1);
    }

    layers--;
}

/*
 * Function:    malloc_check_data()
 *
 * Arguments:   func    - name of function calling this routine
 *      ptr - pointer to area to check
 *      len     - length to verify
 *
 * Purpose: to verify that if ptr is within the malloc arena, the data
 *      it points to does not extend beyond the applicable region.
 *
 * Returns: Nothing of any use (function is void).
 *
 * Narrative:
 *   IF pointer is within malloc arena
 *      call malloc_verify() to verify data is withing applicable region
 *   return
 *
 * Mod History:
 *   90/01/24   cpcahil     Initial revision.
 *   90/01/29   cpcahil     Added code to ignore recursive calls.
 */
void
malloc_check_data(func,ptr,len)
    char        * func;
    char        * ptr;
    int       len;
{
    static int    layers;

    if( layers++ == 0 )
    {
        DEBUG3(40,"malloc_check_data(%s,0x%x,%d) called...",
            func,ptr,len);
        if( malloc_in_arena(ptr) )
        {
            DEBUG0(10,"pointer in malloc arena, verifying...");
            malloc_verify(func,ptr,len);
        }
    }

    layers--;
}

/*
 * Function:    malloc_verify()
 *
 * Arguments:   func    - name of function calling the malloc check routines
 *      ptr - pointer to area to check
 *      len     - length to verify
 *
 * Purpose: to verify that the data ptr points to does not extend beyond
 *      the applicable malloc region.  This function is only called
 *      if it has been determined that ptr points into the malloc arena.
 *
 * Returns: Nothing of any use (function is void).
 *
 * Narrative:
 *
 * Mod History:
 *   90/01/24   cpcahil     Initial revision.
 */
void
malloc_verify(func,ptr,len)
    char        * func;
    char        * ptr;
    int       len;
{
    extern struct mlist * malloc_end;
    extern int        malloc_errno;
    extern struct mlist       malloc_start;
    struct mlist        * mptr;

    DEBUG3(40,"malloc_verify(%s,0x%x,%d) called...", func,ptr,len);
    /*
     * Find the malloc block that includes this pointer
     */
    mptr = &malloc_start;
    while( mptr &&
        ! (((char *)mptr < ptr) && ((mptr->data+mptr->s.size) > ptr) ) )
    {
        mptr = mptr->next;
    }

    /*
     * if ptr was not in a malloc block, it must be part of
     *    some direct sbrk() stuff, so just return.
     */
    if( ! mptr )
    {
        DEBUG1(10,"ptr (0x%x) not found in malloc search", ptr);
        return;
    }

    /*
      * Now we have a valid malloc block that contains the indicated
     * pointer.  We must verify that it is withing the requested block
     * size (as opposed to the real block size which is rounded up to
     * allow for correct alignment).
     */

    DEBUG4(60,"Checking  0x%x-0x%x, 0x%x-0x%x",
            ptr, ptr+len, mptr->data, mptr->data+mptr->r_size);

    if( (ptr < mptr->data) || ((ptr+len) > (mptr->data+mptr->r_size)) )
    {
        DEBUG4(0,"pointer not within region 0x%x-0x%x, 0x%x-0x%x",
            ptr, ptr+len, mptr->data, mptr->data+mptr->r_size);

        malloc_errno = M_CODE_OUTOF_BOUNDS;
        malloc_warning(func);
    }

    return;
}