/*
   Unix SMB/CIFS implementation.

   libndr interface

   Copyright (C) Andrew Tridgell 2003
   Copyright (C) Jelmer Vernooij 2005-2008

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/*
  this provides the core routines for NDR parsing functions

  see http://www.opengroup.org/onlinepubs/9629399/chap14.htm for details
  of NDR encoding rules
*/

#include "includes.h"
#include "librpc/ndr/libndr.h"
#include "../lib/util/dlinklist.h"

#define NDR_BASE_MARSHALL_SIZE 1024

/* this guid indicates NDR encoding in a protocol tower */
const struct ndr_syntax_id ndr_transfer_syntax_ndr = {
  { 0x8a885d04, 0x1ceb, 0x11c9, {0x9f, 0xe8}, {0x08,0x00,0x2b,0x10,0x48,0x60} },
  2
};

const struct ndr_syntax_id ndr_transfer_syntax_ndr64 = {
  { 0x71710533, 0xbeba, 0x4937, {0x83, 0x19}, {0xb5,0xdb,0xef,0x9c,0xcc,0x36} },
  1
};

const struct ndr_syntax_id ndr_syntax_id_null = {
  { 0, 0, 0, { 0, 0 }, { 0, 0, 0, 0, 0, 0 } },
  0
};

/*
  work out the number of bytes needed to align on a n byte boundary
*/
_PUBLIC_ size_t ndr_align_size(uint32_t offset, size_t n)
{
	if ((offset & (n-1)) == 0) return 0;
	return n - (offset & (n-1));
}

/*
  initialise a ndr parse structure from a data blob
*/
_PUBLIC_ struct ndr_pull *ndr_pull_init_blob(const DATA_BLOB *blob, TALLOC_CTX *mem_ctx)
{
	struct ndr_pull *ndr;

	ndr = talloc_zero(mem_ctx, struct ndr_pull);
	if (!ndr) return NULL;
	ndr->current_mem_ctx = mem_ctx;

	ndr->data = blob->data;
	ndr->data_size = blob->length;

	return ndr;
}

_PUBLIC_ enum ndr_err_code ndr_pull_append(struct ndr_pull *ndr, DATA_BLOB *blob)
{
	enum ndr_err_code ndr_err;
	DATA_BLOB b;
	uint32_t append = 0;
	bool ok;

	if (blob->length == 0) {
		return NDR_ERR_SUCCESS;
	}

	ndr_err = ndr_token_retrieve(&ndr->array_size_list, ndr, &append);
	if (ndr_err == NDR_ERR_TOKEN) {
		append = 0;
		ndr_err = NDR_ERR_SUCCESS;
	}
	NDR_CHECK(ndr_err);

	if (ndr->data_size == 0) {
		ndr->data = NULL;
		append = UINT32_MAX;
	}

	if (append == UINT32_MAX) {
		/*
		 * append == UINT32_MAX means that
		 * ndr->data is either NULL or a valid
		 * talloc child of ndr, which means
		 * we can use data_blob_append() without
		 * data_blob_talloc() of the existing callers data
		 */
		b = data_blob_const(ndr->data, ndr->data_size);
	} else {
		b = data_blob_talloc(ndr, ndr->data, ndr->data_size);
		if (b.data == NULL) {
			return ndr_pull_error(ndr, NDR_ERR_ALLOC, "%s", __location__);
		}
	}

	ok = data_blob_append(ndr, &b, blob->data, blob->length);
	if (!ok) {
		return ndr_pull_error(ndr, NDR_ERR_ALLOC, "%s", __location__);
	}

	ndr->data = b.data;
	ndr->data_size = b.length;

	return ndr_token_store(ndr, &ndr->array_size_list, ndr, UINT32_MAX);
}

_PUBLIC_ enum ndr_err_code ndr_pull_pop(struct ndr_pull *ndr)
{
	uint32_t skip = 0;
	uint32_t append = 0;

	if (ndr->relative_base_offset != 0) {
		return ndr_pull_error(ndr, NDR_ERR_RELATIVE,
				      "%s", __location__);
	}
	if (ndr->relative_highest_offset != 0) {
		return ndr_pull_error(ndr, NDR_ERR_RELATIVE,
				      "%s", __location__);
	}
	if (ndr->relative_list != NULL) {
		return ndr_pull_error(ndr, NDR_ERR_RELATIVE,
				      "%s", __location__);
	}
	if (ndr->relative_base_list != NULL) {
		return ndr_pull_error(ndr, NDR_ERR_RELATIVE,
				      "%s", __location__);
	}

	/*
	 * we need to keep up to 7 bytes
	 * in order to get the aligment right.
	 */
	skip = ndr->offset & 0xFFFFFFF8;

	if (skip == 0) {
		return NDR_ERR_SUCCESS;
	}

	ndr->offset -= skip;
	ndr->data_size -= skip;

	append = ndr_token_peek(&ndr->array_size_list, ndr);
	if (append != UINT32_MAX) {
		/*
		 * here we assume, that ndr->data is not a
		 * talloc child of ndr.
		 */
		ndr->data += skip;
		return NDR_ERR_SUCCESS;
	}

	memmove(ndr->data, ndr->data + skip, ndr->data_size);

	ndr->data = talloc_realloc(ndr, ndr->data, uint8_t, ndr->data_size);
	if (ndr->data_size != 0 && ndr->data == NULL) {
		return ndr_pull_error(ndr, NDR_ERR_ALLOC, "%s", __location__);
	}

	return NDR_ERR_SUCCESS;
}

/*
  advance by 'size' bytes
*/
_PUBLIC_ enum ndr_err_code ndr_pull_advance(struct ndr_pull *ndr, uint32_t size)
{
	ndr->offset += size;
	if (ndr->offset > ndr->data_size) {
		return ndr_pull_error(ndr, NDR_ERR_BUFSIZE, 
				      "ndr_pull_advance by %u failed",
				      size);
	}
	return NDR_ERR_SUCCESS;
}

/*
  set the parse offset to 'ofs'
*/
static enum ndr_err_code ndr_pull_set_offset(struct ndr_pull *ndr, uint32_t ofs)
{
	ndr->offset = ofs;
	if (ndr->offset > ndr->data_size) {
		return ndr_pull_error(ndr, NDR_ERR_BUFSIZE, 
				      "ndr_pull_set_offset %u failed",
				      ofs);
	}
	return NDR_ERR_SUCCESS;
}

/* create a ndr_push structure, ready for some marshalling */
_PUBLIC_ struct ndr_push *ndr_push_init_ctx(TALLOC_CTX *mem_ctx)
{
	struct ndr_push *ndr;

	ndr = talloc_zero(mem_ctx, struct ndr_push);
	if (!ndr) {
		return NULL;
	}

	ndr->flags = 0;
	ndr->alloc_size = NDR_BASE_MARSHALL_SIZE;
	ndr->data = talloc_array(ndr, uint8_t, ndr->alloc_size);
	if (!ndr->data) {
		talloc_free(ndr);
		return NULL;
	}

	return ndr;
}

/* return a DATA_BLOB structure for the current ndr_push marshalled data */
_PUBLIC_ DATA_BLOB ndr_push_blob(struct ndr_push *ndr)
{
	DATA_BLOB blob;
	blob = data_blob_const(ndr->data, ndr->offset);
	if (ndr->alloc_size > ndr->offset) {
		ndr->data[ndr->offset] = 0;
	}
	return blob;
}


/*
  expand the available space in the buffer to ndr->offset + extra_size
*/
_PUBLIC_ enum ndr_err_code ndr_push_expand(struct ndr_push *ndr, uint32_t extra_size)
{
	uint32_t size = extra_size + ndr->offset;

	if (size < ndr->offset) {
		/* extra_size overflowed the offset */
		return ndr_push_error(ndr, NDR_ERR_BUFSIZE, "Overflow in push_expand to %u",
				      size);
	}

	if (ndr->fixed_buf_size) {
		if (ndr->alloc_size >= size) {
			return NDR_ERR_SUCCESS;
		}
		return ndr_push_error(ndr,
				      NDR_ERR_BUFSIZE,
				      "Overflow of fixed buffer in "
				      "push_expand to %u",
				      size);
	}
	
	if (ndr->alloc_size > size) {
		return NDR_ERR_SUCCESS;
	}

	ndr->alloc_size += NDR_BASE_MARSHALL_SIZE;
	if (size+1 > ndr->alloc_size) {
		ndr->alloc_size = size+1;
	}
	ndr->data = talloc_realloc(ndr, ndr->data, uint8_t, ndr->alloc_size);
	if (!ndr->data) {
		return ndr_push_error(ndr, NDR_ERR_ALLOC, "Failed to push_expand to %u",
				      ndr->alloc_size);
	}

	return NDR_ERR_SUCCESS;
}

_PUBLIC_ void ndr_print_debugc_helper(struct ndr_print *ndr, const char *format, ...)
{
	va_list ap;
	char *s = NULL;
	uint32_t i;
	int ret;
	int dbgc_class;

	va_start(ap, format);
	ret = vasprintf(&s, format, ap);
	va_end(ap);

	if (ret == -1) {
		return;
	}

	dbgc_class = *(int *)ndr->private_data;

	if (ndr->no_newline) {
		DEBUGADDC(dbgc_class, 1,("%s", s));
		free(s);
		return;
	}

	for (i=0;i<ndr->depth;i++) {
		DEBUGADDC(dbgc_class, 1,("    "));
	}

	DEBUGADDC(dbgc_class, 1,("%s\n", s));
	free(s);
}

_PUBLIC_ void ndr_print_debug_helper(struct ndr_print *ndr, const char *format, ...) 
{
	va_list ap;
	char *s = NULL;
	uint32_t i;
	int ret;

	va_start(ap, format);
	ret = vasprintf(&s, format, ap);
	va_end(ap);

	if (ret == -1) {
		return;
	}

	if (ndr->no_newline) {
		DEBUGADD(1,("%s", s));
		free(s);
		return;
	}

	for (i=0;i<ndr->depth;i++) {
		DEBUGADD(1,("    "));
	}

	DEBUGADD(1,("%s\n", s));
	free(s);
}

_PUBLIC_ void ndr_print_printf_helper(struct ndr_print *ndr, const char *format, ...) 
{
	va_list ap;
	uint32_t i;

	if (!ndr->no_newline) {
		for (i=0;i<ndr->depth;i++) {
			printf("    ");
		}
	}

	va_start(ap, format);
	vprintf(format, ap);
	va_end(ap);
	if (!ndr->no_newline) {
		printf("\n");
	}
}

_PUBLIC_ void ndr_print_string_helper(struct ndr_print *ndr, const char *format, ...)
{
	va_list ap;
	uint32_t i;

	if (!ndr->no_newline) {
		for (i=0;i<ndr->depth;i++) {
			ndr->private_data = talloc_asprintf_append_buffer(
				(char *)ndr->private_data, "    ");
		}
	}

	va_start(ap, format);
	ndr->private_data = talloc_vasprintf_append_buffer((char *)ndr->private_data, 
						    format, ap);
	va_end(ap);
	if (!ndr->no_newline) {
		ndr->private_data = talloc_asprintf_append_buffer((char *)ndr->private_data,
								  "\n");
	}
}

/*
  a useful helper function for printing idl structures via DEBUGC()
*/
_PUBLIC_ void ndr_print_debugc(int dbgc_class, ndr_print_fn_t fn, const char *name, void *ptr)
{
	struct ndr_print *ndr;

	DEBUGC(dbgc_class, 1,(" "));

	ndr = talloc_zero(NULL, struct ndr_print);
	if (!ndr) return;
	ndr->private_data = &dbgc_class;
	ndr->print = ndr_print_debugc_helper;
	ndr->depth = 1;
	ndr->flags = 0;
	fn(ndr, name, ptr);
	talloc_free(ndr);
}

/*
  a useful helper function for printing idl structures via DEBUG()
*/
_PUBLIC_ void ndr_print_debug(ndr_print_fn_t fn, const char *name, void *ptr)
{
	struct ndr_print *ndr;

	DEBUG(1,(" "));

	ndr = talloc_zero(NULL, struct ndr_print);
	if (!ndr) return;
	ndr->print = ndr_print_debug_helper;
	ndr->depth = 1;
	ndr->flags = 0;
	fn(ndr, name, ptr);
	talloc_free(ndr);
}

/*
  a useful helper function for printing idl unions via DEBUG()
*/
_PUBLIC_ void ndr_print_union_debug(ndr_print_fn_t fn, const char *name, uint32_t level, void *ptr)
{
	struct ndr_print *ndr;

	DEBUG(1,(" "));

	ndr = talloc_zero(NULL, struct ndr_print);
	if (!ndr) return;
	ndr->print = ndr_print_debug_helper;
	ndr->depth = 1;
	ndr->flags = 0;
	ndr_print_set_switch_value(ndr, ptr, level);
	fn(ndr, name, ptr);
	talloc_free(ndr);
}

/*
  a useful helper function for printing idl function calls via DEBUG()
*/
_PUBLIC_ void ndr_print_function_debug(ndr_print_function_t fn, const char *name, int flags, void *ptr)
{
	struct ndr_print *ndr;

	DEBUG(1,(" "));

	ndr = talloc_zero(NULL, struct ndr_print);
	if (!ndr) return;
	ndr->print = ndr_print_debug_helper;
	ndr->depth = 1;
	ndr->flags = 0;

	fn(ndr, name, flags, ptr);
	talloc_free(ndr);
}

/*
  a useful helper function for printing idl structures to a string
*/
_PUBLIC_ char *ndr_print_struct_string(TALLOC_CTX *mem_ctx, ndr_print_fn_t fn, const char *name, void *ptr)
{
	struct ndr_print *ndr;
	char *ret = NULL;

	ndr = talloc_zero(mem_ctx, struct ndr_print);
	if (!ndr) return NULL;
	ndr->private_data = talloc_strdup(ndr, "");
	if (!ndr->private_data) {
		goto failed;
	}
	ndr->print = ndr_print_string_helper;
	ndr->depth = 1;
	ndr->flags = 0;

	fn(ndr, name, ptr);
	ret = talloc_steal(mem_ctx, (char *)ndr->private_data);
failed:
	talloc_free(ndr);
	return ret;
}

/*
  a useful helper function for printing idl unions to a string
*/
_PUBLIC_ char *ndr_print_union_string(TALLOC_CTX *mem_ctx, ndr_print_fn_t fn, const char *name, uint32_t level, void *ptr)
{
	struct ndr_print *ndr;
	char *ret = NULL;

	ndr = talloc_zero(mem_ctx, struct ndr_print);
	if (!ndr) return NULL;
	ndr->private_data = talloc_strdup(ndr, "");
	if (!ndr->private_data) {
		goto failed;
	}
	ndr->print = ndr_print_string_helper;
	ndr->depth = 1;
	ndr->flags = 0;
	ndr_print_set_switch_value(ndr, ptr, level);
	fn(ndr, name, ptr);
	ret = talloc_steal(mem_ctx, (char *)ndr->private_data);
failed:
	talloc_free(ndr);
	return ret;
}

/*
  a useful helper function for printing idl function calls to a string
*/
_PUBLIC_ char *ndr_print_function_string(TALLOC_CTX *mem_ctx,
				ndr_print_function_t fn, const char *name, 
				int flags, void *ptr)
{
	struct ndr_print *ndr;
	char *ret = NULL;

	ndr = talloc_zero(mem_ctx, struct ndr_print);
	if (!ndr) return NULL;
	ndr->private_data = talloc_strdup(ndr, "");
	if (!ndr->private_data) {
		goto failed;
	}
	ndr->print = ndr_print_string_helper;
	ndr->depth = 1;
	ndr->flags = 0;
	fn(ndr, name, flags, ptr);
	ret = talloc_steal(mem_ctx, (char *)ndr->private_data);
failed:
	talloc_free(ndr);
	return ret;
}

_PUBLIC_ void ndr_set_flags(uint32_t *pflags, uint32_t new_flags)
{
	/* the big/little endian flags are inter-dependent */
	if (new_flags & LIBNDR_FLAG_LITTLE_ENDIAN) {
		(*pflags) &= ~LIBNDR_FLAG_BIGENDIAN;
		(*pflags) &= ~LIBNDR_FLAG_NDR64;
	}
	if (new_flags & LIBNDR_FLAG_BIGENDIAN) {
		(*pflags) &= ~LIBNDR_FLAG_LITTLE_ENDIAN;
		(*pflags) &= ~LIBNDR_FLAG_NDR64;
	}
	if (new_flags & LIBNDR_ALIGN_FLAGS) {
		/* Ensure we only have the passed-in
		   align flag set in the new_flags,
		   remove any old align flag. */
		(*pflags) &= ~LIBNDR_ALIGN_FLAGS;
	}
	if (new_flags & LIBNDR_FLAG_NO_RELATIVE_REVERSE) {
		(*pflags) &= ~LIBNDR_FLAG_RELATIVE_REVERSE;
	}
	(*pflags) |= new_flags;
}

/*
  return and possibly log an NDR error
*/
_PUBLIC_ enum ndr_err_code ndr_pull_error(struct ndr_pull *ndr,
				 enum ndr_err_code ndr_err,
				 const char *format, ...)
{
	char *s=NULL;
	va_list ap;
	int ret;

	if (ndr->flags & LIBNDR_FLAG_INCOMPLETE_BUFFER) {
		switch (ndr_err) {
		case NDR_ERR_BUFSIZE:
			return NDR_ERR_INCOMPLETE_BUFFER;
		default:
			break;
		}
	}

	va_start(ap, format);
	ret = vasprintf(&s, format, ap);
	va_end(ap);

	if (ret == -1) {
		return NDR_ERR_ALLOC;
	}

	DEBUG(1,("ndr_pull_error(%u): %s\n", ndr_err, s));

	free(s);

	return ndr_err;
}

/*
  return and possibly log an NDR error
*/
_PUBLIC_ enum ndr_err_code ndr_push_error(struct ndr_push *ndr,
				 enum ndr_err_code ndr_err,
				 const char *format, ...) 
{
	char *s=NULL;
	va_list ap;
	int ret;

	va_start(ap, format);
	ret = vasprintf(&s, format, ap);
	va_end(ap);

	if (ret == -1) {
		return NDR_ERR_ALLOC;
	}

	DEBUG(1,("ndr_push_error(%u): %s\n", ndr_err, s));

	free(s);

	return ndr_err;
}

/*
  handle subcontext buffers, which in midl land are user-marshalled, but
  we use magic in pidl to make them easier to cope with
*/
_PUBLIC_ enum ndr_err_code ndr_pull_subcontext_start(struct ndr_pull *ndr,
				   struct ndr_pull **_subndr,
				   size_t header_size,
				   ssize_t size_is)
{
	struct ndr_pull *subndr;
	uint32_t r_content_size;
	bool force_le = false;
	bool force_be = false;

	switch (header_size) {
	case 0: {
		uint32_t content_size = ndr->data_size - ndr->offset;
		if (size_is >= 0) {
			content_size = size_is;
		}
		r_content_size = content_size;
		break;
	}

	case 2: {
		uint16_t content_size;
		NDR_CHECK(ndr_pull_uint16(ndr, NDR_SCALARS, &content_size));
		if (size_is >= 0 && size_is != content_size) {
			return ndr_pull_error(ndr, NDR_ERR_SUBCONTEXT, "Bad subcontext (PULL) size_is(%d) (0x%04x) mismatch content_size %d (0x%04x)",
						(int)size_is, (int)size_is,
						(int)content_size,
						(int)content_size);
		}
		r_content_size = content_size;
		break;
	}

	case 4: {
		uint32_t content_size;
		NDR_CHECK(ndr_pull_uint3264(ndr, NDR_SCALARS, &content_size));
		if (size_is >= 0 && size_is != content_size) {
			return ndr_pull_error(ndr, NDR_ERR_SUBCONTEXT, "Bad subcontext (PULL) size_is(%d) (0x%08x) mismatch content_size %d (0x%08x)",
						(int)size_is, (int)size_is,
						(int)content_size,
						(int)content_size);
		}
		r_content_size = content_size;
		break;
	}
	case 0xFFFFFC01: {
		/*
		 * Common Type Header for the Serialization Stream
		 * See [MS-RPCE] 2.2.6 Type Serialization Version 1
		 */
		uint8_t version;
		uint8_t drep;
		uint16_t hdrlen;
		uint32_t filler;
		uint32_t content_size;
		uint32_t reserved;

		/* version */
		NDR_CHECK(ndr_pull_uint8(ndr, NDR_SCALARS, &version));

		if (version != 1) {
			return ndr_pull_error(ndr, NDR_ERR_SUBCONTEXT,
					      "Bad subcontext (PULL) Common Type Header version %d != 1",
					      (int)version);
		}

		/*
		 * 0x10 little endian
		 * 0x00 big endian
		 */
		NDR_CHECK(ndr_pull_uint8(ndr, NDR_SCALARS, &drep));
		if (drep == 0x10) {
			force_le = true;
		} else if (drep == 0x00) {
			force_be = true;
		} else {
			return ndr_pull_error(ndr, NDR_ERR_SUBCONTEXT,
					      "Bad subcontext (PULL) Common Type Header invalid drep 0x%02X",
					      (unsigned int)drep);
		}

		/* length of the "Private Header for Constructed Type" */
		NDR_CHECK(ndr_pull_uint16(ndr, NDR_SCALARS, &hdrlen));
		if (hdrlen != 8) {
			return ndr_pull_error(ndr, NDR_ERR_SUBCONTEXT,
					      "Bad subcontext (PULL) Common Type Header length %d != 8",
					      (int)hdrlen);
		}

		/* filler should be ignored */
		NDR_CHECK(ndr_pull_uint32(ndr, NDR_SCALARS, &filler));

		/*
		 * Private Header for Constructed Type
		 */
		/* length - will be updated latter */
		NDR_CHECK(ndr_pull_uint32(ndr, NDR_SCALARS, &content_size));
		if (size_is >= 0 && size_is != content_size) {
			return ndr_pull_error(ndr, NDR_ERR_SUBCONTEXT, "Bad subcontext (PULL) size_is(%d) mismatch content_size %d",
					      (int)size_is, (int)content_size);
		}
		/* the content size must be a multiple of 8 */
		if ((content_size % 8) != 0) {
			return ndr_pull_error(ndr, NDR_ERR_SUBCONTEXT,
					      "Bad subcontext (PULL) size_is(%d) not padded to 8 content_size %d",
					      (int)size_is, (int)content_size);
		}
		r_content_size = content_size;

		/* reserved */
		NDR_CHECK(ndr_pull_uint32(ndr, NDR_SCALARS, &reserved));
		break;
	}
	case 0xFFFFFFFF:
		/*
		 * a shallow copy like subcontext
		 * useful for DCERPC pipe chunks.
		 */
		subndr = talloc_zero(ndr, struct ndr_pull);
		NDR_ERR_HAVE_NO_MEMORY(subndr);

		subndr->flags		= ndr->flags;
		subndr->current_mem_ctx	= ndr->current_mem_ctx;
		subndr->data		= ndr->data;
		subndr->offset		= ndr->offset;
		subndr->data_size	= ndr->data_size;

		*_subndr = subndr;
		return NDR_ERR_SUCCESS;

	default:
		return ndr_pull_error(ndr, NDR_ERR_SUBCONTEXT, "Bad subcontext (PULL) header_size %d", 
				      (int)header_size);
	}

	NDR_PULL_NEED_BYTES(ndr, r_content_size);

	subndr = talloc_zero(ndr, struct ndr_pull);
	NDR_ERR_HAVE_NO_MEMORY(subndr);
	subndr->flags		= ndr->flags & ~LIBNDR_FLAG_NDR64;
	subndr->current_mem_ctx	= ndr->current_mem_ctx;

	subndr->data = ndr->data + ndr->offset;
	subndr->offset = 0;
	subndr->data_size = r_content_size;

	if (force_le) {
		ndr_set_flags(&ndr->flags, LIBNDR_FLAG_LITTLE_ENDIAN);
	} else if (force_be) {
		ndr_set_flags(&ndr->flags, LIBNDR_FLAG_BIGENDIAN);
	}

	*_subndr = subndr;
	return NDR_ERR_SUCCESS;
}

_PUBLIC_ enum ndr_err_code ndr_pull_subcontext_end(struct ndr_pull *ndr,
				 struct ndr_pull *subndr,
				 size_t header_size,
				 ssize_t size_is)
{
	uint32_t advance;
	uint32_t highest_ofs;

	if (header_size == 0xFFFFFFFF) {
		advance = subndr->offset - ndr->offset;
	} else if (size_is >= 0) {
		advance = size_is;
	} else if (header_size > 0) {
		advance = subndr->data_size;
	} else {
		advance = subndr->offset;
	}

	if (subndr->offset > ndr->relative_highest_offset) {
		highest_ofs = subndr->offset;
	} else {
		highest_ofs = subndr->relative_highest_offset;
	}
	if (!(subndr->flags & LIBNDR_FLAG_SUBCONTEXT_NO_UNREAD_BYTES)) {
		/*
		 * avoid an error unless SUBCONTEXT_NO_UNREAD_BYTES is specified
		 */
		highest_ofs = advance;
	}
	if (highest_ofs < advance) {
		return ndr_pull_error(subndr, NDR_ERR_UNREAD_BYTES,
				      "not all bytes consumed ofs[%u] advance[%u]",
				      highest_ofs, advance);
	}

	NDR_CHECK(ndr_pull_advance(ndr, advance));
	return NDR_ERR_SUCCESS;
}

_PUBLIC_ enum ndr_err_code ndr_push_subcontext_start(struct ndr_push *ndr,
				   struct ndr_push **_subndr,
				   size_t header_size,
				   ssize_t size_is)
{
	struct ndr_push *subndr;

	subndr = ndr_push_init_ctx(ndr);
	NDR_ERR_HAVE_NO_MEMORY(subndr);
	subndr->flags	= ndr->flags & ~LIBNDR_FLAG_NDR64;

	if (size_is > 0) {
		NDR_CHECK(ndr_push_zero(subndr, size_is));
		subndr->offset = 0;
		subndr->relative_end_offset = size_is;
	}

	*_subndr = subndr;
	return NDR_ERR_SUCCESS;
}

/*
  push a subcontext header 
*/
_PUBLIC_ enum ndr_err_code ndr_push_subcontext_end(struct ndr_push *ndr,
				 struct ndr_push *subndr,
				 size_t header_size,
				 ssize_t size_is)
{
	ssize_t padding_len;

	if (size_is >= 0) {
		padding_len = size_is - subndr->offset;
		if (padding_len < 0) {
			return ndr_push_error(ndr, NDR_ERR_SUBCONTEXT, "Bad subcontext (PUSH) content_size %d is larger than size_is(%d)",
					      (int)subndr->offset, (int)size_is);
		}
		subndr->offset = size_is;
	}

	switch (header_size) {
	case 0: 
		break;

	case 2: 
		NDR_CHECK(ndr_push_uint16(ndr, NDR_SCALARS, subndr->offset));
		break;

	case 4: 
		NDR_CHECK(ndr_push_uint3264(ndr, NDR_SCALARS, subndr->offset));
		break;

	case 0xFFFFFC01:
		/*
		 * Common Type Header for the Serialization Stream
		 * See [MS-RPCE] 2.2.6 Type Serialization Version 1
		 */
		padding_len = NDR_ROUND(subndr->offset, 8) - subndr->offset;
		if (padding_len > 0) {
			NDR_CHECK(ndr_push_zero(subndr, padding_len));
		}

		/* version */
		NDR_CHECK(ndr_push_uint8(ndr, NDR_SCALARS, 1));

		/*
		 * 0x10 little endian
		 * 0x00 big endian
		 */
		NDR_CHECK(ndr_push_uint8(ndr, NDR_SCALARS, NDR_BE(ndr)?0x00:0x10));

		/* length of the "Private Header for Constructed Type" */
		NDR_CHECK(ndr_push_uint16(ndr, NDR_SCALARS, 8));

		/* filler */
		NDR_CHECK(ndr_push_uint32(ndr, NDR_SCALARS, 0xCCCCCCCC));

		/*
		 * Private Header for Constructed Type
		 */
		/* length - will be updated latter */
		NDR_CHECK(ndr_push_uint32(ndr, NDR_SCALARS, subndr->offset));

		/* reserved */
		NDR_CHECK(ndr_push_uint32(ndr, NDR_SCALARS, 0));
		break;

	default:
		return ndr_push_error(ndr, NDR_ERR_SUBCONTEXT, "Bad subcontext header size %d", 
				      (int)header_size);
	}

	NDR_CHECK(ndr_push_bytes(ndr, subndr->data, subndr->offset));
	return NDR_ERR_SUCCESS;
}

/*
  store a token in the ndr context, for later retrieval
*/
_PUBLIC_ enum ndr_err_code ndr_token_store(TALLOC_CTX *mem_ctx,
			 struct ndr_token_list **list, 
			 const void *key, 
			 uint32_t value)
{
	struct ndr_token_list *tok;
	tok = talloc(mem_ctx, struct ndr_token_list);
	NDR_ERR_HAVE_NO_MEMORY(tok);
	tok->key = key;
	tok->value = value;
	DLIST_ADD((*list), tok);
	return NDR_ERR_SUCCESS;
}

/*
  retrieve a token from a ndr context, using cmp_fn to match the tokens
*/
_PUBLIC_ enum ndr_err_code ndr_token_retrieve_cmp_fn(struct ndr_token_list **list, const void *key, uint32_t *v,
				   comparison_fn_t _cmp_fn, bool _remove_tok)
{
	struct ndr_token_list *tok;
	for (tok=*list;tok;tok=tok->next) {
		if (_cmp_fn && _cmp_fn(tok->key,key)==0) goto found;
		else if (!_cmp_fn && tok->key == key) goto found;
	}
	return NDR_ERR_TOKEN;
found:
	*v = tok->value;
	if (_remove_tok) {
		DLIST_REMOVE((*list), tok);
		talloc_free(tok);
	}
	return NDR_ERR_SUCCESS;
}

/*
  retrieve a token from a ndr context
*/
_PUBLIC_ enum ndr_err_code ndr_token_retrieve(struct ndr_token_list **list, const void *key, uint32_t *v)
{
	return ndr_token_retrieve_cmp_fn(list, key, v, NULL, true);
}

/*
  peek at but don't removed a token from a ndr context
*/
_PUBLIC_ uint32_t ndr_token_peek(struct ndr_token_list **list, const void *key)
{
	struct ndr_token_list *tok;
	for (tok = *list; tok; tok = tok->next) {
		if (tok->key == key) {
			return tok->value;
		}
	}
	return 0;
}

/*
  pull an array size field and add it to the array_size_list token list
*/
_PUBLIC_ enum ndr_err_code ndr_pull_array_size(struct ndr_pull *ndr, const void *p)
{
	uint32_t size;
	NDR_CHECK(ndr_pull_uint3264(ndr, NDR_SCALARS, &size));
	return ndr_token_store(ndr, &ndr->array_size_list, p, size);
}

/*
  get the stored array size field
*/
_PUBLIC_ uint32_t ndr_get_array_size(struct ndr_pull *ndr, const void *p)
{
	return ndr_token_peek(&ndr->array_size_list, p);
}

/*
  check the stored array size field
*/
_PUBLIC_ enum ndr_err_code ndr_check_array_size(struct ndr_pull *ndr, void *p, uint32_t size)
{
	uint32_t stored;
	stored = ndr_token_peek(&ndr->array_size_list, p);
	if (stored != size) {
		return ndr_pull_error(ndr, NDR_ERR_ARRAY_SIZE, 
				      "Bad array size - got %u expected %u\n",
				      stored, size);
	}
	return NDR_ERR_SUCCESS;
}

/*
  pull an array length field and add it to the array_length_list token list
*/
_PUBLIC_ enum ndr_err_code ndr_pull_array_length(struct ndr_pull *ndr, const void *p)
{
	uint32_t length, offset;
	NDR_CHECK(ndr_pull_uint3264(ndr, NDR_SCALARS, &offset));
	if (offset != 0) {
		return ndr_pull_error(ndr, NDR_ERR_ARRAY_SIZE, 
				      "non-zero array offset %u\n", offset);
	}
	NDR_CHECK(ndr_pull_uint3264(ndr, NDR_SCALARS, &length));
	return ndr_token_store(ndr, &ndr->array_length_list, p, length);
}

/*
  get the stored array length field
*/
_PUBLIC_ uint32_t ndr_get_array_length(struct ndr_pull *ndr, const void *p)
{
	return ndr_token_peek(&ndr->array_length_list, p);
}

/*
  check the stored array length field
*/
_PUBLIC_ enum ndr_err_code ndr_check_array_length(struct ndr_pull *ndr, void *p, uint32_t length)
{
	uint32_t stored;
	stored = ndr_token_peek(&ndr->array_length_list, p);
	if (stored != length) {
		return ndr_pull_error(ndr, NDR_ERR_ARRAY_SIZE, 
				      "Bad array length - got %u expected %u\n",
				      stored, length);
	}
	return NDR_ERR_SUCCESS;
}

_PUBLIC_ enum ndr_err_code ndr_push_pipe_chunk_trailer(struct ndr_push *ndr, int ndr_flags, uint32_t count)
{
	if (ndr->flags & LIBNDR_FLAG_NDR64) {
		int64_t tmp = 0 - (int64_t)count;
		uint64_t ncount = tmp;

		NDR_CHECK(ndr_push_hyper(ndr, ndr_flags, ncount));
	}

	return NDR_ERR_SUCCESS;
}

_PUBLIC_ enum ndr_err_code ndr_check_pipe_chunk_trailer(struct ndr_pull *ndr, int ndr_flags, uint32_t count)
{
	if (ndr->flags & LIBNDR_FLAG_NDR64) {
		int64_t tmp = 0 - (int64_t)count;
		uint64_t ncount1 = tmp;
		uint64_t ncount2;

		NDR_CHECK(ndr_pull_hyper(ndr, ndr_flags, &ncount2));
		if (ncount1 == ncount2) {
			return NDR_ERR_SUCCESS;
		}

		return ndr_pull_error(ndr, NDR_ERR_ARRAY_SIZE,
			"Bad pipe trailer[%lld should be %lld] size was %lu\"",
			(unsigned long long)ncount2,
			(unsigned long long)ncount1,
			(unsigned long)count);
	}

	return NDR_ERR_SUCCESS;
}

/*
  store a switch value
 */
_PUBLIC_ enum ndr_err_code ndr_push_set_switch_value(struct ndr_push *ndr, const void *p, uint32_t val)
{
	return ndr_token_store(ndr, &ndr->switch_list, p, val);
}

_PUBLIC_ enum ndr_err_code ndr_pull_set_switch_value(struct ndr_pull *ndr, const void *p, uint32_t val)
{
	return ndr_token_store(ndr, &ndr->switch_list, p, val);
}

_PUBLIC_ enum ndr_err_code ndr_print_set_switch_value(struct ndr_print *ndr, const void *p, uint32_t val)
{
	return ndr_token_store(ndr, &ndr->switch_list, p, val);
}

/*
  retrieve a switch value
 */
_PUBLIC_ uint32_t ndr_push_get_switch_value(struct ndr_push *ndr, const void *p)
{
	return ndr_token_peek(&ndr->switch_list, p);
}

_PUBLIC_ uint32_t ndr_pull_get_switch_value(struct ndr_pull *ndr, const void *p)
{
	return ndr_token_peek(&ndr->switch_list, p);
}

_PUBLIC_ uint32_t ndr_print_get_switch_value(struct ndr_print *ndr, const void *p)
{
	return ndr_token_peek(&ndr->switch_list, p);
}

/* retrieve a switch value and remove it from the list */
_PUBLIC_ uint32_t ndr_pull_steal_switch_value(struct ndr_pull *ndr, const void *p)
{
	enum ndr_err_code status;
	uint32_t v;

	status = ndr_token_retrieve(&ndr->switch_list, p, &v);
	if (!NDR_ERR_CODE_IS_SUCCESS(status)) {
		return 0;
	}

	return v;
}

/*
  pull a struct from a blob using NDR
*/
_PUBLIC_ enum ndr_err_code ndr_pull_struct_blob(const DATA_BLOB *blob, TALLOC_CTX *mem_ctx, void *p,
			      ndr_pull_flags_fn_t fn)
{
	struct ndr_pull *ndr;
	ndr = ndr_pull_init_blob(blob, mem_ctx);
	NDR_ERR_HAVE_NO_MEMORY(ndr);
	NDR_CHECK_FREE(fn(ndr, NDR_SCALARS|NDR_BUFFERS, p));
	talloc_free(ndr);
	return NDR_ERR_SUCCESS;
}

/*
  pull a struct from a blob using NDR - failing if all bytes are not consumed
*/
_PUBLIC_ enum ndr_err_code ndr_pull_struct_blob_all(const DATA_BLOB *blob, TALLOC_CTX *mem_ctx, 
						    void *p, ndr_pull_flags_fn_t fn)
{
	struct ndr_pull *ndr;
	uint32_t highest_ofs;
	ndr = ndr_pull_init_blob(blob, mem_ctx);
	NDR_ERR_HAVE_NO_MEMORY(ndr);
	NDR_CHECK_FREE(fn(ndr, NDR_SCALARS|NDR_BUFFERS, p));
	if (ndr->offset > ndr->relative_highest_offset) {
		highest_ofs = ndr->offset;
	} else {
		highest_ofs = ndr->relative_highest_offset;
	}
	if (highest_ofs < ndr->data_size) {
		enum ndr_err_code ret;
		ret = ndr_pull_error(ndr, NDR_ERR_UNREAD_BYTES,
				     "not all bytes consumed ofs[%u] size[%u]",
				     highest_ofs, ndr->data_size);
		talloc_free(ndr);
		return ret;
	}
	talloc_free(ndr);
	return NDR_ERR_SUCCESS;
}

/*
  pull a struct from a blob using NDR - failing if all bytes are not consumed

  This only works for structures with NO allocated memory, like
  objectSID and GUID.  This helps because we parse these a lot.
*/
_PUBLIC_ enum ndr_err_code ndr_pull_struct_blob_all_noalloc(const DATA_BLOB *blob,
							    void *p, ndr_pull_flags_fn_t fn)
{
	/*
	 * We init this structure on the stack here, to avoid a
	 * talloc() as otherwise this call to the fn() is assured not
	 * to be doing any allocation, eg SIDs and GUIDs.
	 *
	 * This allows us to keep the safety of the PIDL-generated
	 * code without the talloc() overhead.
	 */
	struct ndr_pull ndr = {
		.data = blob->data,
		.data_size = blob->length,
		.current_mem_ctx = (void *)-1
	};
	uint32_t highest_ofs;
	NDR_CHECK(fn(&ndr, NDR_SCALARS|NDR_BUFFERS, p));
	if (ndr.offset > ndr.relative_highest_offset) {
		highest_ofs = ndr.offset;
	} else {
		highest_ofs = ndr.relative_highest_offset;
	}
	if (highest_ofs < ndr.data_size) {
		enum ndr_err_code ret;
		ret = ndr_pull_error(&ndr, NDR_ERR_UNREAD_BYTES,
				     "not all bytes consumed ofs[%u] size[%u]",
				     highest_ofs, ndr.data_size);
		return ret;
	}
	return NDR_ERR_SUCCESS;
}

/*
  pull a union from a blob using NDR, given the union discriminator
*/
_PUBLIC_ enum ndr_err_code ndr_pull_union_blob(const DATA_BLOB *blob, TALLOC_CTX *mem_ctx, 
					       void *p,
			     uint32_t level, ndr_pull_flags_fn_t fn)
{
	struct ndr_pull *ndr;
	ndr = ndr_pull_init_blob(blob, mem_ctx);
	NDR_ERR_HAVE_NO_MEMORY(ndr);
	NDR_CHECK_FREE(ndr_pull_set_switch_value(ndr, p, level));
	NDR_CHECK_FREE(fn(ndr, NDR_SCALARS|NDR_BUFFERS, p));
	talloc_free(ndr);
	return NDR_ERR_SUCCESS;
}

/*
  pull a union from a blob using NDR, given the union discriminator,
  failing if all bytes are not consumed
*/
_PUBLIC_ enum ndr_err_code ndr_pull_union_blob_all(const DATA_BLOB *blob, TALLOC_CTX *mem_ctx, 
						   void *p,
			     uint32_t level, ndr_pull_flags_fn_t fn)
{
	struct ndr_pull *ndr;
	uint32_t highest_ofs;
	ndr = ndr_pull_init_blob(blob, mem_ctx);
	NDR_ERR_HAVE_NO_MEMORY(ndr);
	NDR_CHECK_FREE(ndr_pull_set_switch_value(ndr, p, level));
	NDR_CHECK_FREE(fn(ndr, NDR_SCALARS|NDR_BUFFERS, p));
	if (ndr->offset > ndr->relative_highest_offset) {
		highest_ofs = ndr->offset;
	} else {
		highest_ofs = ndr->relative_highest_offset;
	}
	if (highest_ofs < ndr->data_size) {
		enum ndr_err_code ret;
		ret = ndr_pull_error(ndr, NDR_ERR_UNREAD_BYTES,
				     "not all bytes consumed ofs[%u] size[%u]",
				     highest_ofs, ndr->data_size);
		talloc_free(ndr);
		return ret;
	}
	talloc_free(ndr);
	return NDR_ERR_SUCCESS;
}

/*
  push a struct to a blob using NDR
*/
_PUBLIC_ enum ndr_err_code ndr_push_struct_blob(DATA_BLOB *blob, TALLOC_CTX *mem_ctx, const void *p, ndr_push_flags_fn_t fn)
{
	struct ndr_push *ndr;
	ndr = ndr_push_init_ctx(mem_ctx);
	NDR_ERR_HAVE_NO_MEMORY(ndr);

	NDR_CHECK(fn(ndr, NDR_SCALARS|NDR_BUFFERS, p));

	*blob = ndr_push_blob(ndr);
	talloc_steal(mem_ctx, blob->data);
	talloc_free(ndr);

	return NDR_ERR_SUCCESS;
}

/* 
  push a struct into a provided blob using NDR. 
 
  We error because we want to have the performance issue (extra
  talloc() calls) show up as an error, not just slower code.  This is
  used for things like GUIDs, which we expect to be a fixed size, and
  SIDs that we can pre-calculate the size for.
*/
_PUBLIC_ enum ndr_err_code ndr_push_struct_into_fixed_blob(
	DATA_BLOB *blob, const void *p, ndr_push_flags_fn_t fn)
{
	struct ndr_push ndr = {
		.data = blob->data,
		.alloc_size = blob->length,
		.fixed_buf_size = true
	};

	NDR_CHECK(fn(&ndr, NDR_SCALARS|NDR_BUFFERS, p));

	if (ndr.offset != blob->length) {
		return ndr_push_error(&ndr, NDR_ERR_BUFSIZE,
				      "buffer was either to large or small "
				      "ofs[%u] size[%zu]",
				      ndr.offset, blob->length);
	}

	return NDR_ERR_SUCCESS;
}

/*
  push a union to a blob using NDR
*/
_PUBLIC_ enum ndr_err_code ndr_push_union_blob(DATA_BLOB *blob, TALLOC_CTX *mem_ctx, void *p,
			     uint32_t level, ndr_push_flags_fn_t fn)
{
	struct ndr_push *ndr;
	ndr = ndr_push_init_ctx(mem_ctx);
	NDR_ERR_HAVE_NO_MEMORY(ndr);

	NDR_CHECK(ndr_push_set_switch_value(ndr, p, level));
	NDR_CHECK(fn(ndr, NDR_SCALARS|NDR_BUFFERS, p));

	*blob = ndr_push_blob(ndr);
	talloc_steal(mem_ctx, blob->data);
	talloc_free(ndr);

	return NDR_ERR_SUCCESS;
}

/*
  generic ndr_size_*() handler for structures
*/
_PUBLIC_ size_t ndr_size_struct(const void *p, int flags, ndr_push_flags_fn_t push)
{
	struct ndr_push *ndr;
	enum ndr_err_code status;
	size_t ret;

	/* avoid recursion */
	if (flags & LIBNDR_FLAG_NO_NDR_SIZE) return 0;

	ndr = ndr_push_init_ctx(NULL);
	if (!ndr) return 0;
	ndr->flags |= flags | LIBNDR_FLAG_NO_NDR_SIZE;
	status = push(ndr, NDR_SCALARS|NDR_BUFFERS, discard_const(p));
	if (!NDR_ERR_CODE_IS_SUCCESS(status)) {
		talloc_free(ndr);
		return 0;
	}
	ret = ndr->offset;
	talloc_free(ndr);
	return ret;
}

/*
  generic ndr_size_*() handler for unions
*/
_PUBLIC_ size_t ndr_size_union(const void *p, int flags, uint32_t level, ndr_push_flags_fn_t push)
{
	struct ndr_push *ndr;
	enum ndr_err_code status;
	size_t ret;

	/* avoid recursion */
	if (flags & LIBNDR_FLAG_NO_NDR_SIZE) return 0;

	ndr = ndr_push_init_ctx(NULL);
	if (!ndr) return 0;
	ndr->flags |= flags | LIBNDR_FLAG_NO_NDR_SIZE;

	status = ndr_push_set_switch_value(ndr, p, level);
	if (!NDR_ERR_CODE_IS_SUCCESS(status)) {
		talloc_free(ndr);
		return 0;
	}
	status = push(ndr, NDR_SCALARS|NDR_BUFFERS, p);
	if (!NDR_ERR_CODE_IS_SUCCESS(status)) {
		talloc_free(ndr);
		return 0;
	}
	ret = ndr->offset;
	talloc_free(ndr);
	return ret;
}

/*
  get the current base for relative pointers for the push
*/
_PUBLIC_ uint32_t ndr_push_get_relative_base_offset(struct ndr_push *ndr)
{
	return ndr->relative_base_offset;
}

/*
  restore the old base for relative pointers for the push
*/
_PUBLIC_ void ndr_push_restore_relative_base_offset(struct ndr_push *ndr, uint32_t offset)
{
	ndr->relative_base_offset = offset;
}

/*
  setup the current base for relative pointers for the push
  called in the NDR_SCALAR stage
*/
_PUBLIC_ enum ndr_err_code ndr_push_setup_relative_base_offset1(struct ndr_push *ndr, const void *p, uint32_t offset)
{
	ndr->relative_base_offset = offset;
	return ndr_token_store(ndr, &ndr->relative_base_list, p, offset);
}

/*
  setup the current base for relative pointers for the push
  called in the NDR_BUFFERS stage
*/
_PUBLIC_ enum ndr_err_code ndr_push_setup_relative_base_offset2(struct ndr_push *ndr, const void *p)
{
	return ndr_token_retrieve(&ndr->relative_base_list, p, &ndr->relative_base_offset);
}

/*
  push a relative object - stage1
  this is called during SCALARS processing
*/
_PUBLIC_ enum ndr_err_code ndr_push_relative_ptr1(struct ndr_push *ndr, const void *p)
{
	if (p == NULL) {
		NDR_CHECK(ndr_push_uint32(ndr, NDR_SCALARS, 0));
		return NDR_ERR_SUCCESS;
	}
	NDR_CHECK(ndr_push_align(ndr, 4));
	NDR_CHECK(ndr_token_store(ndr, &ndr->relative_list, p, ndr->offset));
	return ndr_push_uint32(ndr, NDR_SCALARS, 0xFFFFFFFF);
}

/*
  push a short relative object - stage1
  this is called during SCALARS processing
*/
_PUBLIC_ enum ndr_err_code ndr_push_short_relative_ptr1(struct ndr_push *ndr, const void *p)
{
	if (p == NULL) {
		NDR_CHECK(ndr_push_uint16(ndr, NDR_SCALARS, 0));
		return NDR_ERR_SUCCESS;
	}
	NDR_CHECK(ndr_push_align(ndr, 2));
	NDR_CHECK(ndr_token_store(ndr, &ndr->relative_list, p, ndr->offset));
	return ndr_push_uint16(ndr, NDR_SCALARS, 0xFFFF);
}
/*
  push a relative object - stage2
  this is called during buffers processing
*/
static enum ndr_err_code ndr_push_relative_ptr2(struct ndr_push *ndr, const void *p)
{
	uint32_t save_offset;
	uint32_t ptr_offset = 0xFFFFFFFF;
	if (p == NULL) {
		return NDR_ERR_SUCCESS;
	}
	save_offset = ndr->offset;
	NDR_CHECK(ndr_token_retrieve(&ndr->relative_list, p, &ptr_offset));
	if (ptr_offset > ndr->offset) {
		return ndr_push_error(ndr, NDR_ERR_BUFSIZE, 
				      "ndr_push_relative_ptr2 ptr_offset(%u) > ndr->offset(%u)",
				      ptr_offset, ndr->offset);
	}
	ndr->offset = ptr_offset;
	if (save_offset < ndr->relative_base_offset) {
		return ndr_push_error(ndr, NDR_ERR_BUFSIZE, 
				      "ndr_push_relative_ptr2 save_offset(%u) < ndr->relative_base_offset(%u)",
				      save_offset, ndr->relative_base_offset);
	}	
	NDR_CHECK(ndr_push_uint32(ndr, NDR_SCALARS, save_offset - ndr->relative_base_offset));
	ndr->offset = save_offset;
	return NDR_ERR_SUCCESS;
}
/*
  push a short relative object - stage2
  this is called during buffers processing
*/
_PUBLIC_ enum ndr_err_code ndr_push_short_relative_ptr2(struct ndr_push *ndr, const void *p)
{
	uint32_t save_offset;
	uint32_t ptr_offset = 0xFFFF;
	uint32_t relative_offset;
	size_t pad;
	size_t align = 1;

	if (p == NULL) {
		return NDR_ERR_SUCCESS;
	}

	if (ndr->offset < ndr->relative_base_offset) {
		return ndr_push_error(ndr, NDR_ERR_BUFSIZE,
				      "ndr_push_relative_ptr2 ndr->offset(%u) < ndr->relative_base_offset(%u)",
				      ndr->offset, ndr->relative_base_offset);
	}

	relative_offset = ndr->offset - ndr->relative_base_offset;

	if (ndr->flags & LIBNDR_FLAG_NOALIGN) {
		align = 1;
	} else if (ndr->flags & LIBNDR_FLAG_ALIGN2) {
		align = 2;
	} else if (ndr->flags & LIBNDR_FLAG_ALIGN4) {
		align = 4;
	} else if (ndr->flags & LIBNDR_FLAG_ALIGN8) {
		align = 8;
	}

	pad = ndr_align_size(relative_offset, align);
	if (pad != 0) {
		NDR_CHECK(ndr_push_zero(ndr, pad));
	}

	relative_offset = ndr->offset - ndr->relative_base_offset;
	if (relative_offset > UINT16_MAX) {
		return ndr_push_error(ndr, NDR_ERR_BUFSIZE,
				      "ndr_push_relative_ptr2 relative_offset(%u) > UINT16_MAX",
				      relative_offset);
	}

	save_offset = ndr->offset;
	NDR_CHECK(ndr_token_retrieve(&ndr->relative_list, p, &ptr_offset));
	if (ptr_offset > ndr->offset) {
		return ndr_push_error(ndr, NDR_ERR_BUFSIZE,
				      "ndr_push_short_relative_ptr2 ptr_offset(%u) > ndr->offset(%u)",
				      ptr_offset, ndr->offset);
	}
	ndr->offset = ptr_offset;
	NDR_CHECK(ndr_push_uint16(ndr, NDR_SCALARS, relative_offset));
	ndr->offset = save_offset;
	return NDR_ERR_SUCCESS;
}

/*
  push a relative object - stage2 start
  this is called during buffers processing
*/
_PUBLIC_ enum ndr_err_code ndr_push_relative_ptr2_start(struct ndr_push *ndr, const void *p)
{
	if (p == NULL) {
		return NDR_ERR_SUCCESS;
	}
	if (!(ndr->flags & LIBNDR_FLAG_RELATIVE_REVERSE)) {
		uint32_t relative_offset;
		size_t pad;
		size_t align = 1;

		if (ndr->offset < ndr->relative_base_offset) {
			return ndr_push_error(ndr, NDR_ERR_BUFSIZE,
				      "ndr_push_relative_ptr2_start ndr->offset(%u) < ndr->relative_base_offset(%u)",
				      ndr->offset, ndr->relative_base_offset);
		}

		relative_offset = ndr->offset - ndr->relative_base_offset;

		if (ndr->flags & LIBNDR_FLAG_NOALIGN) {
			align = 1;
		} else if (ndr->flags & LIBNDR_FLAG_ALIGN2) {
			align = 2;
		} else if (ndr->flags & LIBNDR_FLAG_ALIGN4) {
			align = 4;
		} else if (ndr->flags & LIBNDR_FLAG_ALIGN8) {
			align = 8;
		}

		pad = ndr_align_size(relative_offset, align);
		if (pad) {
			NDR_CHECK(ndr_push_zero(ndr, pad));
		}

		return ndr_push_relative_ptr2(ndr, p);
	}
	if (ndr->relative_end_offset == -1) {
		return ndr_push_error(ndr, NDR_ERR_RELATIVE,
			      "ndr_push_relative_ptr2_start RELATIVE_REVERSE flag set and relative_end_offset %d",
			      ndr->relative_end_offset);
	}
	NDR_CHECK(ndr_token_store(ndr, &ndr->relative_begin_list, p, ndr->offset));
	return NDR_ERR_SUCCESS;
}

/*
  push a relative object - stage2 end
  this is called during buffers processing
*/
_PUBLIC_ enum ndr_err_code ndr_push_relative_ptr2_end(struct ndr_push *ndr, const void *p)
{
	uint32_t begin_offset = 0xFFFFFFFF;
	ssize_t len;
	uint32_t correct_offset = 0;
	uint32_t align = 1;
	uint32_t pad = 0;

	if (p == NULL) {
		return NDR_ERR_SUCCESS;
	}

	if (!(ndr->flags & LIBNDR_FLAG_RELATIVE_REVERSE)) {
		return NDR_ERR_SUCCESS;
	}

	if (ndr->flags & LIBNDR_FLAG_NO_NDR_SIZE) {
		/* better say more than calculation a too small buffer */
		NDR_PUSH_ALIGN(ndr, 8);
		return NDR_ERR_SUCCESS;
	}

	if (ndr->relative_end_offset < ndr->offset) {
		return ndr_push_error(ndr, NDR_ERR_RELATIVE,
				      "ndr_push_relative_ptr2_end:"
				      "relative_end_offset %u < offset %u",
				      ndr->relative_end_offset, ndr->offset);
	}

	NDR_CHECK(ndr_token_retrieve(&ndr->relative_begin_list, p, &begin_offset));

	/* we have marshalled a buffer, see how long it was */
	len = ndr->offset - begin_offset;

	if (len < 0) {
		return ndr_push_error(ndr, NDR_ERR_RELATIVE,
				      "ndr_push_relative_ptr2_end:"
				      "offset %u - begin_offset %u < 0",
				      ndr->offset, begin_offset);
	}

	if (ndr->relative_end_offset < len) {
		return ndr_push_error(ndr, NDR_ERR_RELATIVE,
				      "ndr_push_relative_ptr2_end:"
				      "relative_end_offset %u < len %lld",
				      ndr->offset, (long long)len);
	}

	/* the reversed offset is at the end of the main buffer */
	correct_offset = ndr->relative_end_offset - len;

	if (ndr->flags & LIBNDR_FLAG_NOALIGN) {
		align = 1;
	} else if (ndr->flags & LIBNDR_FLAG_ALIGN2) {
		align = 2;
	} else if (ndr->flags & LIBNDR_FLAG_ALIGN4) {
		align = 4;
	} else if (ndr->flags & LIBNDR_FLAG_ALIGN8) {
		align = 8;
	}

	pad = ndr_align_size(correct_offset, align);
	if (pad) {
		correct_offset += pad;
		correct_offset -= align;
	}

	if (correct_offset < begin_offset) {
		return ndr_push_error(ndr, NDR_ERR_RELATIVE,
				      "ndr_push_relative_ptr2_end: "
				      "correct_offset %u < begin_offset %u",
				      correct_offset, begin_offset);
	}

	if (len > 0) {
		uint32_t clear_size = correct_offset - begin_offset;

		clear_size = MIN(clear_size, len);

		/* now move the marshalled buffer to the end of the main buffer */
		memmove(ndr->data + correct_offset, ndr->data + begin_offset, len);

		if (clear_size) {
			/* and wipe out old buffer within the main buffer */
			memset(ndr->data + begin_offset, '\0', clear_size);
		}
	}

	/* and set the end offset for the next buffer */
	ndr->relative_end_offset = correct_offset;

	/* finally write the offset to the main buffer */
	ndr->offset = correct_offset;
	NDR_CHECK(ndr_push_relative_ptr2(ndr, p));

	/* restore to where we were in the main buffer */
	ndr->offset = begin_offset;

	return NDR_ERR_SUCCESS;
}

/*
  get the current base for relative pointers for the pull
*/
_PUBLIC_ uint32_t ndr_pull_get_relative_base_offset(struct ndr_pull *ndr)
{
	return ndr->relative_base_offset;
}

/*
  restore the old base for relative pointers for the pull
*/
_PUBLIC_ void ndr_pull_restore_relative_base_offset(struct ndr_pull *ndr, uint32_t offset)
{
	ndr->relative_base_offset = offset;
}

/*
  setup the current base for relative pointers for the pull
  called in the NDR_SCALAR stage
*/
_PUBLIC_ enum ndr_err_code ndr_pull_setup_relative_base_offset1(struct ndr_pull *ndr, const void *p, uint32_t offset)
{
	ndr->relative_base_offset = offset;
	return ndr_token_store(ndr, &ndr->relative_base_list, p, offset);
}

/*
  setup the current base for relative pointers for the pull
  called in the NDR_BUFFERS stage
*/
_PUBLIC_ enum ndr_err_code ndr_pull_setup_relative_base_offset2(struct ndr_pull *ndr, const void *p)
{
	return ndr_token_retrieve(&ndr->relative_base_list, p, &ndr->relative_base_offset);
}

/*
  pull a relative object - stage1
  called during SCALARS processing
*/
_PUBLIC_ enum ndr_err_code ndr_pull_relative_ptr1(struct ndr_pull *ndr, const void *p, uint32_t rel_offset)
{
	rel_offset += ndr->relative_base_offset;
	if (rel_offset > ndr->data_size) {
		return ndr_pull_error(ndr, NDR_ERR_BUFSIZE, 
				      "ndr_pull_relative_ptr1 rel_offset(%u) > ndr->data_size(%u)",
				      rel_offset, ndr->data_size);
	}
	return ndr_token_store(ndr, &ndr->relative_list, p, rel_offset);
}

/*
  pull a relative object - stage2
  called during BUFFERS processing
*/
_PUBLIC_ enum ndr_err_code ndr_pull_relative_ptr2(struct ndr_pull *ndr, const void *p)
{
	uint32_t rel_offset;
	NDR_CHECK(ndr_token_retrieve(&ndr->relative_list, p, &rel_offset));
	return ndr_pull_set_offset(ndr, rel_offset);
}

const static struct {
	enum ndr_err_code err;
	const char *string;
} ndr_err_code_strings[] = {
	{ NDR_ERR_SUCCESS, "Success" },
	{ NDR_ERR_ARRAY_SIZE, "Bad Array Size" },
	{ NDR_ERR_BAD_SWITCH, "Bad Switch" },
	{ NDR_ERR_OFFSET, "Offset Error" },
	{ NDR_ERR_RELATIVE, "Relative Pointer Error" },
	{ NDR_ERR_CHARCNV, "Character Conversion Error" },
	{ NDR_ERR_LENGTH, "Length Error" },
	{ NDR_ERR_SUBCONTEXT, "Subcontext Error" },
	{ NDR_ERR_COMPRESSION, "Compression Error" },
	{ NDR_ERR_STRING, "String Error" },
	{ NDR_ERR_VALIDATE, "Validate Error" },
	{ NDR_ERR_BUFSIZE, "Buffer Size Error" },
	{ NDR_ERR_ALLOC, "Allocation Error" },
	{ NDR_ERR_RANGE, "Range Error" },
	{ NDR_ERR_TOKEN, "Token Error" },
	{ NDR_ERR_IPV4ADDRESS, "IPv4 Address Error" },
	{ NDR_ERR_INVALID_POINTER, "Invalid Pointer" },
	{ NDR_ERR_UNREAD_BYTES, "Unread Bytes" },
	{ NDR_ERR_NDR64, "NDR64 assertion error" },
	{ NDR_ERR_INCOMPLETE_BUFFER, "Incomplete Buffer" },
	{ 0, NULL }
};

_PUBLIC_ const char *ndr_map_error2string(enum ndr_err_code ndr_err)
{
	int i;
	for (i = 0; ndr_err_code_strings[i].string != NULL; i++) {
		if (ndr_err_code_strings[i].err == ndr_err)
			return ndr_err_code_strings[i].string;
	}
	return "Unknown error";
}