streams.c

/*
   +----------------------------------------------------------------------+
   | PHP Version 7                                                        |
   +----------------------------------------------------------------------+
   | Copyright (c) 1997-2018 The PHP Group                                |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | http://www.php.net/license/3_01.txt                                  |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | Authors: Wez Furlong <wez@thebrainroom.com>                          |
   | Borrowed code from:                                                  |
   |          Rasmus Lerdorf <rasmus@lerdorf.on.ca>                       |
   |          Jim Winstead <jimw@php.net>                                 |
   +----------------------------------------------------------------------+
 */

/* $Id$ */

#define _GNU_SOURCE
#include "php.h"
#include "php_globals.h"
#include "php_network.h"
#include "php_open_temporary_file.h"
#include "ext/standard/file.h"
#include "ext/standard/basic_functions.h" /* for BG(mmap_file) (not strictly required) */
#include "ext/standard/php_string.h" /* for php_memnstr, used by php_stream_get_record() */
#include <stddef.h>
#include <fcntl.h>
#include "php_streams_int.h"

/* {{{ resource and registration code */
/* Global wrapper hash, copied to FG(stream_wrappers) on registration of volatile wrapper */
static HashTable url_stream_wrappers_hash;
static int le_stream = FAILURE; /* true global */
static int le_pstream = FAILURE; /* true global */
static int le_stream_filter = FAILURE; /* true global */

PHPAPI int php_file_le_stream(void)
{
	return le_stream;
}

PHPAPI int php_file_le_pstream(void)
{
	return le_pstream;
}

PHPAPI int php_file_le_stream_filter(void)
{
	return le_stream_filter;
}

PHPAPI HashTable *_php_stream_get_url_stream_wrappers_hash(void)
{
	return (FG(stream_wrappers) ? FG(stream_wrappers) : &url_stream_wrappers_hash);
}

PHPAPI HashTable *php_stream_get_url_stream_wrappers_hash_global(void)
{
	return &url_stream_wrappers_hash;
}

static int forget_persistent_resource_id_numbers(zval *el)
{
	php_stream *stream;
	zend_resource *rsrc = Z_RES_P(el);

	if (rsrc->type != le_pstream) {
		return 0;
	}

	stream = (php_stream*)rsrc->ptr;

#if STREAM_DEBUG
fprintf(stderr, "forget_persistent: %s:%p\n", stream->ops->label, stream);
#endif

	stream->res = NULL;

	if (stream->ctx) {
		zend_list_delete(stream->ctx);
		stream->ctx = NULL;
	}

	return 0;
}

PHP_RSHUTDOWN_FUNCTION(streams)
{
	zend_hash_apply(&EG(persistent_list), forget_persistent_resource_id_numbers);
	return SUCCESS;
}

PHPAPI php_stream *php_stream_encloses(php_stream *enclosing, php_stream *enclosed)
{
	php_stream *orig = enclosed->enclosing_stream;

	php_stream_auto_cleanup(enclosed);
	enclosed->enclosing_stream = enclosing;
	return orig;
}

PHPAPI int php_stream_from_persistent_id(const char *persistent_id, php_stream **stream)
{
	zend_resource *le;

	if ((le = zend_hash_str_find_ptr(&EG(persistent_list), persistent_id, strlen(persistent_id))) != NULL) {
		if (le->type == le_pstream) {
			if (stream) {
				zend_resource *regentry = NULL;

				/* see if this persistent resource already has been loaded to the
				 * regular list; allowing the same resource in several entries in the
				 * regular list causes trouble (see bug #54623) */
				*stream = (php_stream*)le->ptr;
				ZEND_HASH_FOREACH_PTR(&EG(regular_list), regentry) {
					if (regentry->ptr == le->ptr) {
						GC_REFCOUNT(regentry)++;
						(*stream)->res = regentry;
						return PHP_STREAM_PERSISTENT_SUCCESS;
					}
				} ZEND_HASH_FOREACH_END();
				GC_REFCOUNT(le)++;
				(*stream)->res = zend_register_resource(*stream, le_pstream);
			}
			return PHP_STREAM_PERSISTENT_SUCCESS;
		}
		return PHP_STREAM_PERSISTENT_FAILURE;
	}
	return PHP_STREAM_PERSISTENT_NOT_EXIST;
}

/* }}} */

static zend_llist *php_get_wrapper_errors_list(php_stream_wrapper *wrapper)
{
    if (!FG(wrapper_errors)) {
        return NULL;
    } else {
        return (zend_llist*) zend_hash_str_find_ptr(FG(wrapper_errors), (const char*)&wrapper, sizeof(wrapper));
    }
}

/* {{{ wrapper error reporting */
void php_stream_display_wrapper_errors(php_stream_wrapper *wrapper, const char *path, const char *caption)
{
	char *tmp = estrdup(path);
	char *msg;
	int free_msg = 0;

	if (wrapper) {
		zend_llist *err_list = php_get_wrapper_errors_list(wrapper);
		if (err_list) {
			size_t l = 0;
			int brlen;
			int i;
			int count = (int)zend_llist_count(err_list);
			const char *br;
			const char **err_buf_p;
			zend_llist_position pos;

			if (PG(html_errors)) {
				brlen = 7;
				br = "<br />\n";
			} else {
				brlen = 1;
				br = "\n";
			}

			for (err_buf_p = zend_llist_get_first_ex(err_list, &pos), i = 0;
					err_buf_p;
					err_buf_p = zend_llist_get_next_ex(err_list, &pos), i++) {
				l += strlen(*err_buf_p);
				if (i < count - 1) {
					l += brlen;
				}
			}
			msg = emalloc(l + 1);
			msg[0] = '\0';
			for (err_buf_p = zend_llist_get_first_ex(err_list, &pos), i = 0;
					err_buf_p;
					err_buf_p = zend_llist_get_next_ex(err_list, &pos), i++) {
				strcat(msg, *err_buf_p);
				if (i < count - 1) {
					strcat(msg, br);
				}
			}

			free_msg = 1;
		} else {
			if (wrapper == &php_plain_files_wrapper) {
				msg = strerror(errno); /* TODO: not ts on linux */
			} else {
				msg = "operation failed";
			}
		}
	} else {
		msg = "no suitable wrapper could be found";
	}

	php_strip_url_passwd(tmp);
	php_error_docref1(NULL, tmp, E_WARNING, "%s: %s", caption, msg);
	efree(tmp);
	if (free_msg) {
		efree(msg);
	}
}

void php_stream_tidy_wrapper_error_log(php_stream_wrapper *wrapper)
{
	if (wrapper && FG(wrapper_errors)) {
		zend_hash_str_del(FG(wrapper_errors), (const char*)&wrapper, sizeof(wrapper));
	}
}

static void wrapper_error_dtor(void *error)
{
	efree(*(char**)error);
}

static void wrapper_list_dtor(zval *item) {
	zend_llist *list = (zend_llist*)Z_PTR_P(item);
	zend_llist_destroy(list);
	efree(list);
}

PHPAPI void php_stream_wrapper_log_error(php_stream_wrapper *wrapper, int options, const char *fmt, ...)
{
	va_list args;
	char *buffer = NULL;

	va_start(args, fmt);
	vspprintf(&buffer, 0, fmt, args);
	va_end(args);

	if (options & REPORT_ERRORS || wrapper == NULL) {
		php_error_docref(NULL, E_WARNING, "%s", buffer);
		efree(buffer);
	} else {
		zend_llist *list = NULL;
		if (!FG(wrapper_errors)) {
			ALLOC_HASHTABLE(FG(wrapper_errors));
			zend_hash_init(FG(wrapper_errors), 8, NULL, wrapper_list_dtor, 0);
		} else {
			list = zend_hash_str_find_ptr(FG(wrapper_errors), (const char*)&wrapper, sizeof(wrapper));
		}

		if (!list) {
			zend_llist new_list;
			zend_llist_init(&new_list, sizeof(buffer), wrapper_error_dtor, 0);
			list = zend_hash_str_update_mem(FG(wrapper_errors), (const char*)&wrapper,
					sizeof(wrapper), &new_list, sizeof(new_list));
		}

		/* append to linked list */
		zend_llist_add_element(list, &buffer);
	}
}


/* }}} */

/* allocate a new stream for a particular ops */
PHPAPI php_stream *_php_stream_alloc(php_stream_ops *ops, void *abstract, const char *persistent_id, const char *mode STREAMS_DC) /* {{{ */
{
	php_stream *ret;

	ret = (php_stream*) pemalloc_rel_orig(sizeof(php_stream), persistent_id ? 1 : 0);

	memset(ret, 0, sizeof(php_stream));

	ret->readfilters.stream = ret;
	ret->writefilters.stream = ret;

#if STREAM_DEBUG
fprintf(stderr, "stream_alloc: %s:%p persistent=%s\n", ops->label, ret, persistent_id);
#endif

	ret->ops = ops;
	ret->abstract = abstract;
	ret->is_persistent = persistent_id ? 1 : 0;
	ret->chunk_size = FG(def_chunk_size);

#if ZEND_DEBUG
	ret->open_filename = __zend_orig_filename ? __zend_orig_filename : __zend_filename;
	ret->open_lineno = __zend_orig_lineno ? __zend_orig_lineno : __zend_lineno;
#endif

	if (FG(auto_detect_line_endings)) {
		ret->flags |= PHP_STREAM_FLAG_DETECT_EOL;
	}

	if (persistent_id) {
		zval tmp;

		ZVAL_NEW_PERSISTENT_RES(&tmp, -1, ret, le_pstream);

		if (NULL == zend_hash_str_update(&EG(persistent_list), persistent_id,
					strlen(persistent_id), &tmp)) {
			pefree(ret, 1);
			return NULL;
		}
	}

	ret->res = zend_register_resource(ret, persistent_id ? le_pstream : le_stream);
	strlcpy(ret->mode, mode, sizeof(ret->mode));

	ret->wrapper          = NULL;
	ret->wrapperthis      = NULL;
	ZVAL_UNDEF(&ret->wrapperdata);
	ret->stdiocast        = NULL;
	ret->orig_path        = NULL;
	ret->ctx              = NULL;
	ret->readbuf          = NULL;
	ret->enclosing_stream = NULL;

	return ret;
}
/* }}} */

PHPAPI int _php_stream_free_enclosed(php_stream *stream_enclosed, int close_options) /* {{{ */
{
	return php_stream_free(stream_enclosed,
		close_options | PHP_STREAM_FREE_IGNORE_ENCLOSING);
}
/* }}} */

#if STREAM_DEBUG
static const char *_php_stream_pretty_free_options(int close_options, char *out)
{
	if (close_options & PHP_STREAM_FREE_CALL_DTOR)
		strcat(out, "CALL_DTOR, ");
	if (close_options & PHP_STREAM_FREE_RELEASE_STREAM)
		strcat(out, "RELEASE_STREAM, ");
	if (close_options & PHP_STREAM_FREE_PRESERVE_HANDLE)
		strcat(out, "PREVERSE_HANDLE, ");
	if (close_options & PHP_STREAM_FREE_RSRC_DTOR)
		strcat(out, "RSRC_DTOR, ");
	if (close_options & PHP_STREAM_FREE_PERSISTENT)
		strcat(out, "PERSISTENT, ");
	if (close_options & PHP_STREAM_FREE_IGNORE_ENCLOSING)
		strcat(out, "IGNORE_ENCLOSING, ");
	if (out[0] != '\0')
		out[strlen(out) - 2] = '\0';
	return out;
}
#endif

static int _php_stream_free_persistent(zval *zv, void *pStream)
{
	zend_resource *le = Z_RES_P(zv);
	return le->ptr == pStream;
}


PHPAPI int _php_stream_free(php_stream *stream, int close_options) /* {{{ */
{
	int ret = 1;
	int preserve_handle = close_options & PHP_STREAM_FREE_PRESERVE_HANDLE ? 1 : 0;
	int release_cast = 1;
	php_stream_context *context = NULL;

	/* on an resource list destruction, the context, another resource, may have
	 * already been freed (if it was created after the stream resource), so
	 * don't reference it */
	if (EG(active)) {
		context = PHP_STREAM_CONTEXT(stream);
	}

	if (stream->flags & PHP_STREAM_FLAG_NO_CLOSE) {
		preserve_handle = 1;
	}

#if STREAM_DEBUG
	{
		char out[200] = "";
		fprintf(stderr, "stream_free: %s:%p[%s] in_free=%d opts=%s\n",
			stream->ops->label, stream, stream->orig_path, stream->in_free, _php_stream_pretty_free_options(close_options, out));
	}

#endif

	if (stream->in_free) {
		/* hopefully called recursively from the enclosing stream; the pointer was NULLed below */
		if ((stream->in_free == 1) && (close_options & PHP_STREAM_FREE_IGNORE_ENCLOSING) && (stream->enclosing_stream == NULL)) {
			close_options |= PHP_STREAM_FREE_RSRC_DTOR; /* restore flag */
		} else {
			return 1; /* recursion protection */
		}
	}

	stream->in_free++;

	/* force correct order on enclosing/enclosed stream destruction (only from resource
	 * destructor as in when reverse destroying the resource list) */
	if ((close_options & PHP_STREAM_FREE_RSRC_DTOR) &&
			!(close_options & PHP_STREAM_FREE_IGNORE_ENCLOSING) &&
			(close_options & (PHP_STREAM_FREE_CALL_DTOR | PHP_STREAM_FREE_RELEASE_STREAM)) && /* always? */
			(stream->enclosing_stream != NULL)) {
		php_stream *enclosing_stream = stream->enclosing_stream;
		stream->enclosing_stream = NULL;
		/* we force PHP_STREAM_CALL_DTOR because that's from where the
		 * enclosing stream can free this stream. We remove rsrc_dtor because
		 * we want the enclosing stream to be deleted from the resource list */
		return php_stream_free(enclosing_stream,
			(close_options | PHP_STREAM_FREE_CALL_DTOR) & ~PHP_STREAM_FREE_RSRC_DTOR);
	}

	/* if we are releasing the stream only (and preserving the underlying handle),
	 * we need to do things a little differently.
	 * We are only ever called like this when the stream is cast to a FILE*
	 * for include (or other similar) purposes.
	 * */
	if (preserve_handle) {
		if (stream->fclose_stdiocast == PHP_STREAM_FCLOSE_FOPENCOOKIE) {
			/* If the stream was fopencookied, we must NOT touch anything
			 * here, as the cookied stream relies on it all.
			 * Instead, mark the stream as OK to auto-clean */
			php_stream_auto_cleanup(stream);
			stream->in_free--;
			return 0;
		}
		/* otherwise, make sure that we don't close the FILE* from a cast */
		release_cast = 0;
	}

#if STREAM_DEBUG
fprintf(stderr, "stream_free: %s:%p[%s] preserve_handle=%d release_cast=%d remove_rsrc=%d\n",
		stream->ops->label, stream, stream->orig_path, preserve_handle, release_cast,
		(close_options & PHP_STREAM_FREE_RSRC_DTOR) == 0);
#endif

	if (stream->flags & PHP_STREAM_FLAG_WAS_WRITTEN) {
		/* make sure everything is saved */
		_php_stream_flush(stream, 1);
	}

	/* If not called from the resource dtor, remove the stream from the resource list. */
	if ((close_options & PHP_STREAM_FREE_RSRC_DTOR) == 0 && stream->res) {
		/* Close resource, but keep it in resource list */
		zend_list_close(stream->res);
		if ((close_options & PHP_STREAM_FREE_KEEP_RSRC) == 0) {
			/* Completely delete zend_resource, if not referenced */
			zend_list_delete(stream->res);
			stream->res = NULL;
		}
	}

	if (close_options & PHP_STREAM_FREE_CALL_DTOR) {
		if (release_cast && stream->fclose_stdiocast == PHP_STREAM_FCLOSE_FOPENCOOKIE) {
			/* calling fclose on an fopencookied stream will ultimately
				call this very same function.  If we were called via fclose,
				the cookie_closer unsets the fclose_stdiocast flags, so
				we can be sure that we only reach here when PHP code calls
				php_stream_free.
				Lets let the cookie code clean it all up.
			 */
			stream->in_free = 0;
			return fclose(stream->stdiocast);
		}

		ret = stream->ops->close(stream, preserve_handle ? 0 : 1);
		stream->abstract = NULL;

		/* tidy up any FILE* that might have been fdopened */
		if (release_cast && stream->fclose_stdiocast == PHP_STREAM_FCLOSE_FDOPEN && stream->stdiocast) {
			fclose(stream->stdiocast);
			stream->stdiocast = NULL;
			stream->fclose_stdiocast = PHP_STREAM_FCLOSE_NONE;
		}
	}

	if (close_options & PHP_STREAM_FREE_RELEASE_STREAM) {
		while (stream->readfilters.head) {
			php_stream_filter_remove(stream->readfilters.head, 1);
		}
		while (stream->writefilters.head) {
			php_stream_filter_remove(stream->writefilters.head, 1);
		}

		if (stream->wrapper && stream->wrapper->wops && stream->wrapper->wops->stream_closer) {
			stream->wrapper->wops->stream_closer(stream->wrapper, stream);
			stream->wrapper = NULL;
		}

		if (Z_TYPE(stream->wrapperdata) != IS_UNDEF) {
			zval_ptr_dtor(&stream->wrapperdata);
			ZVAL_UNDEF(&stream->wrapperdata);
		}

		if (stream->readbuf) {
			pefree(stream->readbuf, stream->is_persistent);
			stream->readbuf = NULL;
		}

		if (stream->is_persistent && (close_options & PHP_STREAM_FREE_PERSISTENT)) {
			/* we don't work with *stream but need its value for comparison */
			zend_hash_apply_with_argument(&EG(persistent_list), _php_stream_free_persistent, stream);
		}
#if ZEND_DEBUG
		if ((close_options & PHP_STREAM_FREE_RSRC_DTOR) && (stream->__exposed == 0) && (EG(error_reporting) & E_WARNING)) {
			/* it leaked: Lets deliberately NOT pefree it so that the memory manager shows it
			 * as leaked; it will log a warning, but lets help it out and display what kind
			 * of stream it was. */
			if (!CG(unclean_shutdown)) {
				char *leakinfo;
				spprintf(&leakinfo, 0, __FILE__ "(%d) : Stream of type '%s' %p (path:%s) was not closed\n", __LINE__, stream->ops->label, stream, stream->orig_path);

				if (stream->orig_path) {
					pefree(stream->orig_path, stream->is_persistent);
					stream->orig_path = NULL;
				}

# if defined(PHP_WIN32)
				OutputDebugString(leakinfo);
# else
				fprintf(stderr, "%s", leakinfo);
# endif
				efree(leakinfo);
			}
		} else {
			if (stream->orig_path) {
				pefree(stream->orig_path, stream->is_persistent);
				stream->orig_path = NULL;
			}

			pefree(stream, stream->is_persistent);
		}
#else
		if (stream->orig_path) {
			pefree(stream->orig_path, stream->is_persistent);
			stream->orig_path = NULL;
		}

		pefree(stream, stream->is_persistent);
#endif
	}

	if (context) {
		zend_list_delete(context->res);
	}

	return ret;
}
/* }}} */

/* {{{ generic stream operations */

PHPAPI void _php_stream_fill_read_buffer(php_stream *stream, size_t size)
{
	/* allocate/fill the buffer */

	if (stream->readfilters.head) {
		char *chunk_buf;
		int err_flag = 0;
		php_stream_bucket_brigade brig_in = { NULL, NULL }, brig_out = { NULL, NULL };
		php_stream_bucket_brigade *brig_inp = &brig_in, *brig_outp = &brig_out, *brig_swap;

		/* Invalidate the existing cache, otherwise reads can fail, see note in
		   main/streams/filter.c::_php_stream_filter_append */
		stream->writepos = stream->readpos = 0;

		/* allocate a buffer for reading chunks */
		chunk_buf = emalloc(stream->chunk_size);

		while (!stream->eof && !err_flag && (stream->writepos - stream->readpos < (zend_off_t)size)) {
			size_t justread = 0;
			int flags;
			php_stream_bucket *bucket;
			php_stream_filter_status_t status = PSFS_ERR_FATAL;
			php_stream_filter *filter;

			/* read a chunk into a bucket */
			justread = stream->ops->read(stream, chunk_buf, stream->chunk_size);
			if (justread && justread != (size_t)-1) {
				bucket = php_stream_bucket_new(stream, chunk_buf, justread, 0, 0);

				/* after this call, bucket is owned by the brigade */
				php_stream_bucket_append(brig_inp, bucket);

				flags = PSFS_FLAG_NORMAL;
			} else {
				flags = stream->eof ? PSFS_FLAG_FLUSH_CLOSE : PSFS_FLAG_FLUSH_INC;
			}

			/* wind the handle... */
			for (filter = stream->readfilters.head; filter; filter = filter->next) {
				status = filter->fops->filter(stream, filter, brig_inp, brig_outp, NULL, flags);

				if (status != PSFS_PASS_ON) {
					break;
				}

				/* brig_out becomes brig_in.
				 * brig_in will always be empty here, as the filter MUST attach any un-consumed buckets
				 * to its own brigade */
				brig_swap = brig_inp;
				brig_inp = brig_outp;
				brig_outp = brig_swap;
				memset(brig_outp, 0, sizeof(*brig_outp));
			}

			switch (status) {
				case PSFS_PASS_ON:
					/* we get here when the last filter in the chain has data to pass on.
					 * in this situation, we are passing the brig_in brigade into the
					 * stream read buffer */
					while (brig_inp->head) {
						bucket = brig_inp->head;
						/* grow buffer to hold this bucket
						 * TODO: this can fail for persistent streams */
						if (stream->readbuflen - stream->writepos < bucket->buflen) {
							stream->readbuflen += bucket->buflen;
							stream->readbuf = perealloc(stream->readbuf, stream->readbuflen,
									stream->is_persistent);
						}
						memcpy(stream->readbuf + stream->writepos, bucket->buf, bucket->buflen);
						stream->writepos += bucket->buflen;

						php_stream_bucket_unlink(bucket);
						php_stream_bucket_delref(bucket);
					}
					break;

				case PSFS_FEED_ME:
					/* when a filter needs feeding, there is no brig_out to deal with.
					 * we simply continue the loop; if the caller needs more data,
					 * we will read again, otherwise out job is done here */
					if (justread == 0) {
						/* there is no data */
						err_flag = 1;
						break;
					}
					continue;

				case PSFS_ERR_FATAL:
					/* some fatal error. Theoretically, the stream is borked, so all
					 * further reads should fail. */
					err_flag = 1;
					break;
			}

			if (justread == 0 || justread == (size_t)-1) {
				break;
			}
		}

		efree(chunk_buf);

	} else {
		/* is there enough data in the buffer ? */
		if (stream->writepos - stream->readpos < (zend_off_t)size) {
			size_t justread = 0;

			/* reduce buffer memory consumption if possible, to avoid a realloc */
			if (stream->readbuf && stream->readbuflen - stream->writepos < stream->chunk_size) {
				memmove(stream->readbuf, stream->readbuf + stream->readpos, stream->readbuflen - stream->readpos);
				stream->writepos -= stream->readpos;
				stream->readpos = 0;
			}

			/* grow the buffer if required
			 * TODO: this can fail for persistent streams */
			if (stream->readbuflen - stream->writepos < stream->chunk_size) {
				stream->readbuflen += stream->chunk_size;
				stream->readbuf = perealloc(stream->readbuf, stream->readbuflen,
						stream->is_persistent);
			}

			justread = stream->ops->read(stream, (char*)stream->readbuf + stream->writepos,
					stream->readbuflen - stream->writepos
					);

			if (justread != (size_t)-1) {
				stream->writepos += justread;
			}
		}
	}
}

PHPAPI size_t _php_stream_read(php_stream *stream, char *buf, size_t size)
{
	size_t toread = 0, didread = 0;

	while (size > 0) {

		/* take from the read buffer first.
		 * It is possible that a buffered stream was switched to non-buffered, so we
		 * drain the remainder of the buffer before using the "raw" read mode for
		 * the excess */
		if (stream->writepos > stream->readpos) {

			toread = stream->writepos - stream->readpos;
			if (toread > size) {
				toread = size;
			}

			memcpy(buf, stream->readbuf + stream->readpos, toread);
			stream->readpos += toread;
			size -= toread;
			buf += toread;
			didread += toread;
		}

		/* ignore eof here; the underlying state might have changed */
		if (size == 0) {
			break;
		}

		if (!stream->readfilters.head && (stream->flags & PHP_STREAM_FLAG_NO_BUFFER || stream->chunk_size == 1)) {
			toread = stream->ops->read(stream, buf, size);
			if (toread == (size_t) -1) {
				/* e.g. underlying read(2) returned -1 */
				break;
			}
		} else {
			php_stream_fill_read_buffer(stream, size);

			toread = stream->writepos - stream->readpos;
			if (toread > size) {
				toread = size;
			}

			if (toread > 0) {
				memcpy(buf, stream->readbuf + stream->readpos, toread);
				stream->readpos += toread;
			}
		}
		if (toread > 0) {
			didread += toread;
			buf += toread;
			size -= toread;
		} else {
			/* EOF, or temporary end of data (for non-blocking mode). */
			break;
		}

		/* just break anyway, to avoid greedy read */
		if (stream->wrapper != &php_plain_files_wrapper) {
			break;
		}
	}

	if (didread > 0) {
		stream->position += didread;
	}

	return didread;
}

PHPAPI int _php_stream_eof(php_stream *stream)
{
	/* if there is data in the buffer, it's not EOF */
	if (stream->writepos - stream->readpos > 0) {
		return 0;
	}

	/* use the configured timeout when checking eof */
	if (!stream->eof && PHP_STREAM_OPTION_RETURN_ERR ==
		   	php_stream_set_option(stream, PHP_STREAM_OPTION_CHECK_LIVENESS,
		   	0, NULL)) {
		stream->eof = 1;
	}

	return stream->eof;
}

PHPAPI int _php_stream_putc(php_stream *stream, int c)
{
	unsigned char buf = c;

	if (php_stream_write(stream, (char*)&buf, 1) > 0) {
		return 1;
	}
	return EOF;
}

PHPAPI int _php_stream_getc(php_stream *stream)
{
	char buf;

	if (php_stream_read(stream, &buf, 1) > 0) {
		return buf & 0xff;
	}
	return EOF;
}

PHPAPI int _php_stream_puts(php_stream *stream, const char *buf)
{
	size_t len;
	char newline[2] = "\n"; /* is this OK for Win? */
	len = strlen(buf);

	if (len > 0 && php_stream_write(stream, buf, len) && php_stream_write(stream, newline, 1)) {
		return 1;
	}
	return 0;
}

PHPAPI int _php_stream_stat(php_stream *stream, php_stream_statbuf *ssb)
{
	memset(ssb, 0, sizeof(*ssb));

	/* if the stream was wrapped, allow the wrapper to stat it */
	if (stream->wrapper && stream->wrapper->wops->stream_stat != NULL) {
		return stream->wrapper->wops->stream_stat(stream->wrapper, stream, ssb);
	}

	/* if the stream doesn't directly support stat-ing, return with failure.
	 * We could try and emulate this by casting to a FD and fstat-ing it,
	 * but since the fd might not represent the actual underlying content
	 * this would give bogus results. */
	if (stream->ops->stat == NULL) {
		return -1;
	}

	return (stream->ops->stat)(stream, ssb);
}

PHPAPI const char *php_stream_locate_eol(php_stream *stream, zend_string *buf)
{
	size_t avail;
	const char *cr, *lf, *eol = NULL;
	const char *readptr;

	if (!buf) {
		readptr = (char*)stream->readbuf + stream->readpos;
		avail = stream->writepos - stream->readpos;
	} else {
		readptr = ZSTR_VAL(buf);
		avail = ZSTR_LEN(buf);
	}

	/* Look for EOL */
	if (stream->flags & PHP_STREAM_FLAG_DETECT_EOL) {
		cr = memchr(readptr, '\r', avail);
		lf = memchr(readptr, '\n', avail);

		if (cr && lf != cr + 1 && !(lf && lf < cr)) {
			/* mac */
			stream->flags ^= PHP_STREAM_FLAG_DETECT_EOL;
			stream->flags |= PHP_STREAM_FLAG_EOL_MAC;
			eol = cr;
		} else if ((cr && lf && cr == lf - 1) || (lf)) {
			/* dos or unix endings */
			stream->flags ^= PHP_STREAM_FLAG_DETECT_EOL;
			eol = lf;
		}
	} else if (stream->flags & PHP_STREAM_FLAG_EOL_MAC) {
		eol = memchr(readptr, '\r', avail);
	} else {
		/* unix (and dos) line endings */
		eol = memchr(readptr, '\n', avail);
	}

	return eol;
}

/* If buf == NULL, the buffer will be allocated automatically and will be of an
 * appropriate length to hold the line, regardless of the line length, memory
 * permitting */
PHPAPI char *_php_stream_get_line(php_stream *stream, char *buf, size_t maxlen,
		size_t *returned_len)
{
	size_t avail = 0;
	size_t current_buf_size = 0;
	size_t total_copied = 0;
	int grow_mode = 0;
	char *bufstart = buf;

	if (buf == NULL) {
		grow_mode = 1;
	} else if (maxlen == 0) {
		return NULL;
	}

	/*
	 * If the underlying stream operations block when no new data is readable,
	 * we need to take extra precautions.
	 *
	 * If there is buffered data available, we check for a EOL. If it exists,
	 * we pass the data immediately back to the caller. This saves a call
	 * to the read implementation and will not block where blocking
	 * is not necessary at all.
	 *
	 * If the stream buffer contains more data than the caller requested,
	 * we can also avoid that costly step and simply return that data.
	 */

	for (;;) {
		avail = stream->writepos - stream->readpos;

		if (avail > 0) {
			size_t cpysz = 0;
			char *readptr;
			const char *eol;
			int done = 0;

			readptr = (char*)stream->readbuf + stream->readpos;
			eol = php_stream_locate_eol(stream, NULL);

			if (eol) {
				cpysz = eol - readptr + 1;
				done = 1;
			} else {
				cpysz = avail;
			}

			if (grow_mode) {
				/* allow room for a NUL. If this realloc is really a realloc
				 * (ie: second time around), we get an extra byte. In most
				 * cases, with the default chunk size of 8K, we will only
				 * incur that overhead once.  When people have lines longer
				 * than 8K, we waste 1 byte per additional 8K or so.
				 * That seems acceptable to me, to avoid making this code
				 * hard to follow */
				bufstart = erealloc(bufstart, current_buf_size + cpysz + 1);
				current_buf_size += cpysz + 1;
				buf = bufstart + total_copied;
			} else {
				if (cpysz >= maxlen - 1) {
					cpysz = maxlen - 1;
					done = 1;
				}
			}

			memcpy(buf, readptr, cpysz);

			stream->position += cpysz;
			stream->readpos += cpysz;
			buf += cpysz;
			maxlen -= cpysz;
			total_copied += cpysz;

			if (done) {
				break;
			}
		} else if (stream->eof) {
			break;
		} else {
			/* XXX: Should be fine to always read chunk_size */
			size_t toread;

			if (grow_mode) {
				toread = stream->chunk_size;
			} else {
				toread = maxlen - 1;
				if (toread > stream->chunk_size) {
					toread = stream->chunk_size;
				}
			}

			php_stream_fill_read_buffer(stream, toread);

			if (stream->writepos - stream->readpos == 0) {
				break;
			}
		}
	}

	if (total_copied == 0) {
		if (grow_mode) {
			assert(bufstart == NULL);
		}
		return NULL;
	}

	buf[0] = '\0';
	if (returned_len) {
		*returned_len = total_copied;
	}

	return bufstart;
}

#define STREAM_BUFFERED_AMOUNT(stream) \
	((size_t)(((stream)->writepos) - (stream)->readpos))

static const char *_php_stream_search_delim(php_stream *stream,
											size_t maxlen,
											size_t skiplen,
											const char *delim, /* non-empty! */
											size_t delim_len)
{
	size_t	seek_len;

	/* set the maximum number of bytes we're allowed to read from buffer */
	seek_len = MIN(STREAM_BUFFERED_AMOUNT(stream), maxlen);
	if (seek_len <= skiplen) {
		return NULL;
	}

	if (delim_len == 1) {
		return memchr(&stream->readbuf[stream->readpos + skiplen],
			delim[0], seek_len - skiplen);