/* getdelim.c --- Implementation of replacement getdelim function.
 * Copyright (C) 1994, 1996-1998, 2001, 2003, 2005-2012 Free Software
 * Foundation, Inc.
 *
 * This file is part of GnuTLS.
 *
 * The gnutls library is free software; you can redistribute it
 * and/or modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 */

/* Ported from glibc by Simon Josefsson. */

#include <gnutls_int.h>
#include <gnutls_errors.h>
#include <gnutls/xssl.h>
#include <xssl.h>

#ifndef SSIZE_MAX
#define SSIZE_MAX ((ssize_t) (SIZE_MAX / 2))
#endif

/**
 * xssl_get_delim:
 * @sb: is a #xssl_t structure.
 * @lineptr: a pointer.
 * @n: The size of @lineptr.
 * @delimiter: The delimiter to stop reading at.
 *
 * Read up to (and including) a @delimiter from &sb into *LINEPTR (and
 * NUL-terminate it).  @lineptr is a pointer returned from gnutls_malloc() 
 * (or %NULL), pointing to @n characters of space.  It is realloc'ed as
 * necessary.  
 *
 * Only fatal errors are returned by this function.
 *
 * Returns the number of characters read (not including
 * the null terminator), or a negative error code on error. 
 *
 * Since: 3.1.7
 **/
ssize_t
xssl_getdelim(xssl_t sbuf, char **lineptr, size_t * n, int delimiter)
{
	ssize_t result;
	size_t cur_len = 0;

	if (lineptr == NULL || n == NULL || sbuf == NULL) {
		return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
	}

	if (*lineptr == NULL || *n == 0) {
		char *new_lineptr;
		*n = 120;
		new_lineptr = (char *) gnutls_realloc_fast(*lineptr, *n);
		if (new_lineptr == NULL) {
			result = gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);
			goto fail;
		}
		*lineptr = new_lineptr;
	}

	for (;;) {
		char c;

		result = xssl_read(sbuf, &c, 1);
		if (result < 0) {
			gnutls_assert();
			break;
		}

		/* Make enough space for len+1 (for final NUL) bytes.  */
		if (cur_len + 1 >= *n) {
			size_t needed_max =
			    SSIZE_MAX <
			    SIZE_MAX ? (size_t) SSIZE_MAX + 1 : SIZE_MAX;
			size_t needed = 2 * *n + 1;	/* Be generous. */
			char *new_lineptr;

			if (needed_max < needed)
				needed = needed_max;
			if (cur_len + 1 >= needed) {
				result =
				    gnutls_assert_val
				    (GNUTLS_E_LARGE_PACKET);
				goto fail;
			}

			new_lineptr =
			    (char *) gnutls_realloc_fast(*lineptr, needed);
			if (new_lineptr == NULL) {
				result =
				    gnutls_assert_val
				    (GNUTLS_E_MEMORY_ERROR);
				goto fail;
			}

			*lineptr = new_lineptr;
			*n = needed;
		}

		(*lineptr)[cur_len] = c;
		cur_len++;

		if (c == delimiter)
			break;
	}
	(*lineptr)[cur_len] = '\0';

	if (cur_len != 0)
		result = cur_len;

      fail:

	return result;
}