path: root/source/aparser/parser.c

#include <stdio.h>
#include <stdlib.h>
#include <malloc.h> 
#include <unistd.h>
#include "parser.h"

char *tab_depth(int depth)
{
	static pstring spaces;
	memset(spaces, ' ', depth * 4);
	spaces[depth * 4] = 0;
	return spaces;
}

/****************************************************************************
expand a pointer to be a particular size
****************************************************************************/
void *Realloc(void *p,size_t size)
{
  void *ret=NULL;

  if (size == 0) {
    if (p) free(p);
    DEBUG(5,("Realloc asked for 0 bytes\n"));
    return NULL;
  }

  if (!p)
    ret = (void *)malloc(size);
  else
    ret = (void *)realloc(p,size);

  if (!ret)
    DEBUG(0,("Memory allocation error: failed to expand to %d bytes\n",(int)size));

  return(ret);
}

/*******************************************************************
 Attempt, if needed, to grow a data buffer.
 Also depends on the data stream mode (io).
 ********************************************************************/

BOOL prs_grow(prs_struct *ps, uint32 extra_space)
{
	uint32 new_size;
	char *new_data;

	if(ps->data_offset + extra_space <= ps->buffer_size)
		return True;

	/*
	 * We cannot grow the buffer if we're not reading
	 * into the prs_struct, or if we don't own the memory.
	 */

	if(UNMARSHALLING(ps) || !ps->is_dynamic) {
		DEBUG(0,("prs_grow: Buffer overflow - unable to expand buffer by %u bytes.\n",
				(unsigned int)extra_space));
		return False;
	}
	
	/*
	 * Decide how much extra space we really need.
	 */

	extra_space -= (ps->buffer_size - ps->data_offset);
	if(ps->buffer_size == 0) {
		/*
		 * Ensure we have at least a PDU's length, or extra_space, whichever
		 * is greater.
		 */

		new_size = MAX(MAX_PDU_FRAG_LEN,extra_space);

		if((new_data = malloc(new_size)) == NULL) {
			DEBUG(0,("prs_grow: Malloc failure for size %u.\n", (unsigned int)new_size));
			return False;
		}
		memset(new_data, '\0', new_size );
	} else {
		/*
		 * If the current buffer size is bigger than the space needed, just 
		 * double it, else add extra_space.
		 */
		new_size = MAX(ps->buffer_size*2, ps->buffer_size + extra_space);		

		if ((new_data = Realloc(ps->data_p, new_size)) == NULL) {
			DEBUG(0,("prs_grow: Realloc failure for size %u.\n",
				(unsigned int)new_size));
			return False;
		}
	}
	ps->buffer_size = new_size;
	ps->data_p = new_data;

	return True;
}


/*******************************************************************
 Ensure we can read/write to a given offset.
 ********************************************************************/

char *prs_mem_get(prs_struct *ps, uint32 extra_size)
{
	if(UNMARSHALLING(ps)) {
		/*
		 * If reading, ensure that we can read the requested size item.
		 */
		if (ps->data_offset + extra_size > ps->buffer_size) {
			DEBUG(0,("prs_mem_get: reading data of size %u would overrun buffer.\n",
					(unsigned int)extra_size ));
			return NULL;
		}
	} else {
		/*
		 * Writing - grow the buffer if needed.
		 */
		if(!prs_grow(ps, extra_size))
			return False;
	}
	return &ps->data_p[ps->data_offset];
}


/*******************************************************************
 Stream a uint32.
 ********************************************************************/

BOOL prs_uint32(char *name, prs_struct *ps, int depth, uint32 *data32)
{
	char *q = prs_mem_get(ps, sizeof(uint32));
	if (q == NULL)
		return False;

	DBG_RW_IVAL(name, depth, ps->data_offset, ps->io, ps->bigendian_data, q, *data32)
	ps->data_offset += sizeof(uint32);

	return True;
}

/*******************************************************************
 Initialise a parse structure - malloc the data if requested.
 ********************************************************************/

BOOL prs_init(prs_struct *ps, uint32 size, uint8 align, BOOL io)
{
	ZERO_STRUCTP(ps);
	ps->io = io;
	ps->bigendian_data = False;
	ps->align = align;
	ps->is_dynamic = False;
	ps->data_offset = 0;
	ps->buffer_size = 0;
	ps->data_p = NULL;

	if (size != 0) {
		ps->buffer_size = size;
		if((ps->data_p = (char *)malloc((size_t)size)) == NULL) {
			DEBUG(0,("prs_init: malloc fail for %u bytes.\n", (unsigned int)size));
			return False;
		}
		ps->is_dynamic = True; /* We own this memory. */
	}

	return True;
}

/*******************************************************************
 debug output for parsing info.

 XXXX side-effect of this function is to increase the debug depth XXXX

 ********************************************************************/
void prs_debug(prs_struct *ps, int depth, char *desc, char *fn_name)
{
	DEBUG(5+depth, ("%s%06x %s %s\n", tab_depth(depth), ps->data_offset, fn_name, desc));
}

/*******************************************************************
 Align a the data_len to a multiple of align bytes - filling with
 zeros.
 ********************************************************************/

BOOL prs_align(prs_struct *ps)
{
	uint32 mod = ps->data_offset & (ps->align-1);

	if (ps->align != 0 && mod != 0) {
		uint32 extra_space = (ps->align - mod);
		if(!prs_grow(ps, extra_space))
			return False;
		memset(&ps->data_p[ps->data_offset], '\0', (size_t)extra_space);
		ps->data_offset += extra_space;
	}

	return True;
}

/*******************************************************************
 Reads or writes an NTTIME structure.
********************************************************************/

BOOL smb_io_time(char *desc, NTTIME *nttime, prs_struct *ps, int depth)
{
	if (nttime == NULL)
		return False;

	prs_debug(ps, depth, desc, "smb_io_time");
	depth++;

	if(!prs_align(ps))
		return False;
	
	if(!prs_uint32("low ", ps, depth, &nttime->low)) /* low part */
		return False;
	if(!prs_uint32("high", ps, depth, &nttime->high)) /* high part */
		return False;

	return True;
}


/*******************************************************************
 Reads or writes a UNISTR2 structure.
 XXXX NOTE: UNISTR2 structures need NOT be null-terminated.
   the uni_str_len member tells you how long the string is;
   the uni_max_len member tells you how large the buffer is.
********************************************************************/

BOOL smb_io_unistr2(char *desc, UNISTR2 *uni2, uint32 buffer, prs_struct *ps, int depth)
{
	if (uni2 == NULL)
		return False;

	if (buffer) {

		prs_debug(ps, depth, desc, "smb_io_unistr2");
		depth++;

		if(!prs_align(ps))
			return False;
		
		if(!prs_uint32("uni_max_len", ps, depth, &uni2->uni_max_len))
			return False;
		if(!prs_uint32("undoc      ", ps, depth, &uni2->undoc))
			return False;
		if(!prs_uint32("uni_str_len", ps, depth, &uni2->uni_str_len))
			return False;

		/* oops! XXXX maybe issue a warning that this is happening... */
		if (uni2->uni_max_len > MAX_UNISTRLEN)
			uni2->uni_max_len = MAX_UNISTRLEN;
		if (uni2->uni_str_len > MAX_UNISTRLEN)
			uni2->uni_str_len = MAX_UNISTRLEN;

		/* buffer advanced by indicated length of string
		   NOT by searching for null-termination */
		if(!prs_unistr2(True, "buffer     ", ps, depth, uni2))
			return False;

	} else {

		prs_debug(ps, depth, desc, "smb_io_unistr2 - NULL");
		depth++;
		memset((char *)uni2, '\0', sizeof(*uni2));

	}

	return True;
}

/******************************************************************
 Stream a unicode string, length/buffer specified separately,
 in uint16 chars. We use DBG_RW_PCVAL, not DBG_RW_PSVAL here
 as the unicode string is already in little-endian format.
 ********************************************************************/

BOOL prs_unistr2(BOOL charmode, char *name, prs_struct *ps, int depth, UNISTR2 *str)
{
	char *p = (char *)str->buffer;
	char *q = prs_mem_get(ps, str->uni_str_len * sizeof(uint16));
	if (q == NULL)
		return False;

	/* If we're using big-endian, reverse to get little-endian. */
	if(ps->bigendian_data)
		DBG_RW_PSVAL(charmode, name, depth, ps->data_offset, ps->io, ps->bigendian_data, q, p, str->uni_str_len)
	else
		DBG_RW_PCVAL(charmode, name, depth, ps->data_offset, ps->io, q, p, str->uni_str_len * 2)
	ps->data_offset += (str->uni_str_len * sizeof(uint16));

	return True;
}

void print_asc(int level, unsigned char *buf,int len)
{
	int i;
	for (i=0;i<len;i++)
		DEBUG(level,("%c", isprint(buf[i])?buf[i]:'.'));
}

/*******************************************************************
 read from a socket into memory.
 ********************************************************************/
BOOL prs_read(prs_struct *ps, int fd, size_t len, int timeout)
{
	BOOL ok;
	size_t prev_size = ps->buffer_size;
	if (!prs_grow(ps, len))
	{
		return False;
	}

	if (timeout > 0)
	{
		ok = (read(fd, &ps->data_p[prev_size], len) == len);
	}
	else 
	{
		ok = (read(fd, &ps->data_p[prev_size], len) == len);
	}
	return ok;
}

void dump_data(int level,char *buf1,int len)
{
  unsigned char *buf = (unsigned char *)buf1;
  int i=0;
  if (len<=0) return;

  DEBUG(level,("[%03X] ",i));
  for (i=0;i<len;) {
    DEBUG(level,("%02X ",(int)buf[i]));
    i++;
    if (i%8 == 0) DEBUG(level,(" "));
    if (i%16 == 0) {      
      print_asc(level,&buf[i-16],8); DEBUG(level,(" "));
      print_asc(level,&buf[i-8],8); DEBUG(level,("\n"));
      if (i<len) DEBUG(level,("[%03X] ",i));
    }
  }
  if (i%16) {
    int n;

    n = 16 - (i%16);
    DEBUG(level,(" "));
    if (n>8) DEBUG(level,(" "));
    while (n--) DEBUG(level,("   "));

    n = MIN(8,i%16);
    print_asc(level,&buf[i-(i%16)],n); DEBUG(level,(" "));
    n = (i%16) - n;
    if (n>0) print_asc(level,&buf[i-n],n); 
    DEBUG(level,("\n"));    
  }
}

/*******************************************************************
 Stream a uint64_struct
 ********************************************************************/
BOOL prs_uint64(char *desc, prs_struct *ps, int depth, UINT64_S *data64)
{
	prs_debug(ps, depth, desc, "prs_uint64");
	return prs_uint32("low", ps, depth+1, &data64->low) &&
		prs_uint32("high", ps, depth+1, &data64->high);
}



/*******************************************************************
reads or writes a BUFFER5 structure.
the buf_len member tells you how large the buffer is.
********************************************************************/
BOOL smb_io_buffer5(char *desc, BUFFER5 *buf5, prs_struct *ps, int depth)
{
	prs_debug(ps, depth, desc, "smb_io_buffer5");
	depth++;

	if (buf5 == NULL) return False;

	prs_align(ps);
	prs_uint32("buf_len", ps, depth, &(buf5->buf_len));

	/* reading: alloc the buffer first */
	if ( ps->io )
	{
		buf5->buffer=(uint16 *)malloc( sizeof(uint16)*buf5->buf_len );
	}
	
	prs_uint16s(True, "buffer", ps, depth, buf5->buffer, buf5->buf_len);

	return True;
}

/******************************************************************
 Stream an array of uint16s. Length is number of uint16s.
 ********************************************************************/

BOOL prs_uint16s(BOOL charmode, char *name, prs_struct *ps, int depth, uint16 *data16s, int len)
{
	char *q = prs_mem_get(ps, len * sizeof(uint16));
	if (q == NULL)
		return False;

	DBG_RW_PSVAL(charmode, name, depth, ps->data_offset, ps->io, ps->bigendian_data, q, data16s, len)
	ps->data_offset += (len * sizeof(uint16));

	return True;
}