streams.c

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/*
   +----------------------------------------------------------------------+
   | Copyright (c) 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:           |
   | https://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>                                 |
   +----------------------------------------------------------------------+
 */
 
#ifndef _GNU_SOURCE
# define _GNU_SOURCE
#endif
#include "php.h"
#include "php_globals.h"
#include "php_memory_streams.h"
#include "php_network.h"
#include "php_open_temporary_file.h"
#include "ext/standard/file.h"
#include "ext/standard/basic_functions.h" /* for BG(CurrentStatFile) */
#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)
{
    zval *el;
 
    ZEND_HASH_FOREACH_VAL(&EG(persistent_list), el) {
        forget_persistent_resource_id_numbers(el);
    } ZEND_HASH_FOREACH_END();
    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_ADDREF(regentry);
                        (*stream)->res = regentry;
                        return PHP_STREAM_PERSISTENT_SUCCESS;
                    }
                } ZEND_HASH_FOREACH_END();
                GC_ADDREF(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 */
static void php_stream_display_wrapper_errors(php_stream_wrapper *wrapper, const char *path, const char *caption)
{
    char *tmp;
    char *msg;
    int free_msg = 0;
 
    if (EG(exception)) {
        /* Don't emit additional warnings if an exception has already been thrown. */
        return;
    }
 
    tmp = estrdup(path);
    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);
    }
}
 
static 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(const 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(const 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) {
        if (NULL == zend_register_persistent_resource(persistent_id, strlen(persistent_id), ret, le_pstream)) {
            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, "PRESERVE_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;
 
    /* During shutdown resources may be released before other resources still holding them.
     * When only resources are referenced this is not a problem, because they are refcounted
     * and will only be fully freed once the refcount drops to zero. However, if php_stream*
     * is held directly, we don't have this guarantee. To avoid use-after-free we ignore all
     * stream free operations in shutdown unless they come from the resource list destruction,
     * or by freeing an enclosed stream (in which case resource list destruction will not have
     * freed it). */
    if ((EG(flags) & EG_FLAGS_IN_RESOURCE_SHUTDOWN) &&
            !(close_options & (PHP_STREAM_FREE_RSRC_DTOR|PHP_STREAM_FREE_IGNORE_ENCLOSING))) {
        return 1;
    }
 
    context = PHP_STREAM_CONTEXT(stream);
 
    if ((stream->flags & PHP_STREAM_FLAG_NO_CLOSE) ||
            ((stream->flags & PHP_STREAM_FLAG_NO_RSCR_DTOR_CLOSE) && (close_options & PHP_STREAM_FREE_RSRC_DTOR))) {
        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. */
        return php_stream_free(enclosing_stream,
            (close_options | PHP_STREAM_FREE_CALL_DTOR | PHP_STREAM_FREE_KEEP_RSRC) & ~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 || stream->writefilters.head) {
        /* 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.
                Let's 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) {
            if (stream->readfilters.head->res != NULL) {
                zend_list_close(stream->readfilters.head->res);
            }
            php_stream_filter_remove(stream->readfilters.head, 1);
        }
        while (stream->writefilters.head) {
            if (stream->writefilters.head->res != NULL) {
                zend_list_close(stream->writefilters.head->res);
            }
            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 (stream->orig_path) {
            pefree(stream->orig_path, stream->is_persistent);
            stream->orig_path = NULL;
        }
 
        pefree(stream, stream->is_persistent);
    }
 
    if (context) {
        zend_list_delete(context->res);
    }
 
    return ret;
}
/* }}} */
 
/* {{{ generic stream operations */
 
PHPAPI zend_result _php_stream_fill_read_buffer(php_stream *stream, size_t size)
{
    /* allocate/fill the buffer */
 
    zend_result retval;
    bool old_eof = stream->eof;
 
    if (stream->readfilters.head) {
        size_t to_read_now = MIN(size, stream->chunk_size);
        char *chunk_buf;
        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;
 
        /* allocate a buffer for reading chunks */
        chunk_buf = emalloc(stream->chunk_size);
 
        while (!stream->eof && (stream->writepos - stream->readpos < (zend_off_t)to_read_now)) {
            ssize_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 < 0 && stream->writepos == stream->readpos) {
                efree(chunk_buf);
                retval = FAILURE;
                goto out_check_eof;
            } else if (justread > 0) {
                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 = stream->eof ? PSFS_FLAG_FLUSH_CLOSE : 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;
                        /* reduce buffer memory consumption if possible, to avoid a realloc */
                        if (stream->readbuf && stream->readbuflen - stream->writepos < bucket->buflen) {
                            if (stream->writepos > stream->readpos) {
                                memmove(stream->readbuf, stream->readbuf + stream->readpos, stream->writepos - stream->readpos);
                            }
                            stream->writepos -= stream->readpos;
                            stream->readpos = 0;
                        }
                        /* grow buffer to hold this bucket */
                        if (stream->readbuflen - stream->writepos < bucket->buflen) {
                            stream->readbuflen += bucket->buflen;
                            stream->readbuf = perealloc(stream->readbuf, stream->readbuflen,
                                    stream->is_persistent);
                        }
                        if (bucket->buflen) {
                            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 */
                    break;
 
                case PSFS_ERR_FATAL:
                    /* some fatal error. Theoretically, the stream is borked, so all
                     * further reads should fail. */
                    stream->eof = 1;
                    /* free all data left in brigades */
                    while ((bucket = brig_inp->head)) {
                        /* Remove unconsumed buckets from the input brigade */
                        php_stream_bucket_unlink(bucket);
                        php_stream_bucket_delref(bucket);
                    }
                    while ((bucket = brig_outp->head)) {
                        /* Remove unconsumed buckets from the output brigade */
                        php_stream_bucket_unlink(bucket);
                        php_stream_bucket_delref(bucket);
                    }
                    efree(chunk_buf);
                    retval = FAILURE;
                    goto out_is_eof;
            }
 
            if (justread <= 0) {
                break;
            }
        }
 
        efree(chunk_buf);
        return SUCCESS;
    } else {
        /* is there enough data in the buffer ? */
        if (stream->writepos - stream->readpos < (zend_off_t)size) {
            ssize_t justread = 0;
 
            /* reduce buffer memory consumption if possible, to avoid a realloc */
            if (stream->readbuf && stream->readbuflen - stream->writepos < stream->chunk_size) {
                if (stream->writepos > stream->readpos) {
                    memmove(stream->readbuf, stream->readbuf + stream->readpos, stream->writepos - 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 < 0) {
                retval = FAILURE;
                goto out_check_eof;
            }
            stream->writepos += justread;
            retval = SUCCESS;
            goto out_check_eof;
        }
        return SUCCESS;
    }
 
out_check_eof:
    if (old_eof != stream->eof) {
out_is_eof:
        php_stream_notify_completed(PHP_STREAM_CONTEXT(stream));
    }
    return retval;
}
 
PHPAPI ssize_t _php_stream_read(php_stream *stream, char *buf, size_t size)
{
    ssize_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;
            stream->has_buffered_data = 1;
        }
 
        /* 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 < 0) {
                /* Report an error if the read failed and we did not read any data
                 * before that. Otherwise return the data we did read. */
                if (didread == 0) {
                    return toread;
                }
                break;
            }
        } else {
            if (php_stream_fill_read_buffer(stream, size) != SUCCESS) {
                if (didread == 0) {
                    return -1;
                }
                break;
            }
 
            toread = stream->writepos - stream->readpos;
            if ((size_t) 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;
            stream->has_buffered_data = 1;
        } else {
            /* EOF, or temporary end of data (for non-blocking mode). */
            break;
        }
 
        /* just break anyway, to avoid greedy read for file://, php://memory, and php://temp */
        if ((stream->wrapper != &php_plain_files_wrapper) &&
            (stream->ops != &php_stream_memory_ops) &&
            (stream->ops != &php_stream_temp_ops)) {
            break;
        }
    }
 
    if (didread > 0) {
        stream->position += didread;
        stream->has_buffered_data = 0;
    }
 
    return didread;
}
 
/* Like php_stream_read(), but reading into a zend_string buffer. This has some similarity
 * to the copy_to_mem() operation, but only performs a single direct read. */
PHPAPI zend_string *php_stream_read_to_str(php_stream *stream, size_t len)
{
    zend_string *str = zend_string_alloc(len, 0);
    ssize_t read = php_stream_read(stream, ZSTR_VAL(str), len);
    if (read < 0) {
        zend_string_efree(str);
        return NULL;
    }
 
    ZSTR_LEN(str) = read;
    ZSTR_VAL(str)[read] = 0;
 
    if ((size_t) read < len / 2) {
        return zend_string_truncate(str, read, 0);
    }
    return str;
}
 
PHPAPI bool _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 bool _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) > 0 && php_stream_write(stream, newline, 1) > 0) {
        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 an 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);
    } else {
        return php_memnstr((char*)&stream->readbuf[stream->readpos + skiplen],
                delim, delim_len,
                (char*)&stream->readbuf[stream->readpos + seek_len]);
    }
}
 
PHPAPI zend_string *php_stream_get_record(php_stream *stream, size_t maxlen, const char *delim, size_t delim_len)
{
    zend_string  *ret_buf;               /* returned buffer */
    const char *found_delim = NULL;
    size_t  buffered_len,
            tent_ret_len;           /* tentative returned length */
    bool    has_delim = delim_len > 0;
 
    if (maxlen == 0) {
        return NULL;
    }
 
    if (has_delim) {
        found_delim = _php_stream_search_delim(
            stream, maxlen, 0, delim, delim_len);
    }
 
    buffered_len = STREAM_BUFFERED_AMOUNT(stream);
    /* try to read up to maxlen length bytes while we don't find the delim */
    while (!found_delim && buffered_len < maxlen) {
        size_t  just_read,
                to_read_now;
 
        to_read_now = MIN(maxlen - buffered_len, stream->chunk_size);
 
        php_stream_fill_read_buffer(stream, buffered_len + to_read_now);
 
        just_read = STREAM_BUFFERED_AMOUNT(stream) - buffered_len;
 
        /* Assume the stream is temporarily or permanently out of data */
        if (just_read == 0) {
            break;
        }
 
        if (has_delim) {
            /* search for delimiter, but skip buffered_len (the number of bytes
             * buffered before this loop iteration), as they have already been
             * searched for the delimiter.
             * The left part of the delimiter may still remain in the buffer,
             * so subtract up to <delim_len - 1> from buffered_len, which is
             * the amount of data we skip on this search  as an optimization
             */
            found_delim = _php_stream_search_delim(
                stream, maxlen,
                buffered_len >= (delim_len - 1)
                        ? buffered_len - (delim_len - 1)
                        : 0,
                delim, delim_len);
            if (found_delim) {
                break;
            }
        }
        buffered_len += just_read;
    }
 
    if (has_delim && found_delim) {
        tent_ret_len = found_delim - (char*)&stream->readbuf[stream->readpos];
    } else if (!has_delim && STREAM_BUFFERED_AMOUNT(stream) >= maxlen) {
        tent_ret_len = maxlen;
    } else {
        /* return with error if the delimiter string (if any) was not found, we
         * could not completely fill the read buffer with maxlen bytes and we
         * don't know we've reached end of file. Added with non-blocking streams
         * in mind, where this situation is frequent */
        if (STREAM_BUFFERED_AMOUNT(stream) < maxlen && !stream->eof) {
            return NULL;
        } else if (STREAM_BUFFERED_AMOUNT(stream) == 0 && stream->eof) {
            /* refuse to return an empty string just because by accident
             * we knew of EOF in a read that returned no data */
            return NULL;
        } else {
            tent_ret_len = MIN(STREAM_BUFFERED_AMOUNT(stream), maxlen);
        }
    }
 
    ret_buf = zend_string_alloc(tent_ret_len, 0);
    /* php_stream_read will not call ops->read here because the necessary
     * data is guaranteed to be buffered */
    ZSTR_LEN(ret_buf) = php_stream_read(stream, ZSTR_VAL(ret_buf), tent_ret_len);
 
    if (found_delim) {
        stream->readpos += delim_len;
        stream->position += delim_len;
    }
    ZSTR_VAL(ret_buf)[ZSTR_LEN(ret_buf)] = '\0';
    return ret_buf;
}
 
/* Writes a buffer directly to a stream, using multiple of the chunk size */
static ssize_t _php_stream_write_buffer(php_stream *stream, const char *buf, size_t count)
{
    ssize_t didwrite = 0;
    ssize_t retval;
 
    /* if we have a seekable stream we need to ensure that data is written at the
     * current stream->position. This means invalidating the read buffer and then
     * performing a low-level seek */
    if (stream->ops->seek && (stream->flags & PHP_STREAM_FLAG_NO_SEEK) == 0 && stream->readpos != stream->writepos) {
        stream->readpos = stream->writepos = 0;
 
        stream->ops->seek(stream, stream->position, SEEK_SET, &stream->position);
    }
 
    bool old_eof = stream->eof;
 
    /* See GH-13071: userspace stream is subject to the memory limit. */
    size_t chunk_size = count;
    if (php_stream_is(stream, PHP_STREAM_IS_USERSPACE)) {
        /* If the stream is unbuffered, we can only write one byte at a time. */
        chunk_size = stream->chunk_size;
    }
 
    while (count > 0) {
        ssize_t justwrote = stream->ops->write(stream, buf, MIN(chunk_size, count));
        if (justwrote <= 0) {
            /* If we already successfully wrote some bytes and a write error occurred
             * later, report the successfully written bytes. */
            if (didwrite == 0) {
                retval = justwrote;
                goto out;
            }
            retval = didwrite;
            goto out;
        }
 
        buf += justwrote;
        count -= justwrote;
        didwrite += justwrote;
        stream->position += justwrote;
    }
 
    retval = didwrite;
 
out:
    if (old_eof != stream->eof) {
        php_stream_notify_completed(PHP_STREAM_CONTEXT(stream));
    }
    return retval;
}
 
/* push some data through the write filter chain.
 * buf may be NULL, if flags are set to indicate a flush.
 * This may trigger a real write to the stream.
 * Returns the number of bytes consumed from buf by the first filter in the chain.
 * */
static ssize_t _php_stream_write_filtered(php_stream *stream, const char *buf, size_t count, int flags)
{
    size_t consumed = 0;
    php_stream_bucket *bucket;
    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;
    php_stream_filter_status_t status = PSFS_ERR_FATAL;
    php_stream_filter *filter;
 
    if (buf) {
        bucket = php_stream_bucket_new(stream, (char *)buf, count, 0, 0);
        php_stream_bucket_append(&brig_in, bucket);
    }
 
    for (filter = stream->writefilters.head; filter; filter = filter->next) {
        /* for our return value, we are interested in the number of bytes consumed from
         * the first filter in the chain */
        status = filter->fops->filter(stream, filter, brig_inp, brig_outp,
                filter == stream->writefilters.head ? &consumed : 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:
            /* filter chain generated some output; push it through to the
             * underlying stream */
            while (brig_inp->head) {
                bucket = brig_inp->head;
                if (_php_stream_write_buffer(stream, bucket->buf, bucket->buflen) < 0) {
                    consumed = (ssize_t) -1;
                }
 
                /* Potential error situation - eg: no space on device. Perhaps we should keep this brigade
                 * hanging around and try to write it later.
                 * At the moment, we just drop it on the floor
                 * */
 
                php_stream_bucket_unlink(bucket);
                php_stream_bucket_delref(bucket);
            }
            break;
        case PSFS_FEED_ME:
            /* need more data before we can push data through to the stream */
            break;
 
        case PSFS_ERR_FATAL:
            /* some fatal error.  Theoretically, the stream is borked, so all
             * further writes should fail. */
            return (ssize_t) -1;
    }
 
    return consumed;
}
 
PHPAPI int _php_stream_flush(php_stream *stream, int closing)
{
    int ret = 0;
 
    if (stream->writefilters.head) {
        _php_stream_write_filtered(stream, NULL, 0, closing ? PSFS_FLAG_FLUSH_CLOSE : PSFS_FLAG_FLUSH_INC );
    }
 
    stream->flags &= ~PHP_STREAM_FLAG_WAS_WRITTEN;
 
    if (stream->ops->flush) {
        ret = stream->ops->flush(stream);
    }
 
    return ret;
}
 
PHPAPI ssize_t _php_stream_write(php_stream *stream, const char *buf, size_t count)
{
    ssize_t bytes;
 
    if (count == 0) {
        return 0;
    }
 
    ZEND_ASSERT(buf != NULL);
    if (stream->ops->write == NULL) {
        php_error_docref(NULL, E_NOTICE, "Stream is not writable");
        return (ssize_t) -1;
    }
 
    if (stream->writefilters.head) {
        bytes = _php_stream_write_filtered(stream, buf, count, PSFS_FLAG_NORMAL);
    } else {
        bytes = _php_stream_write_buffer(stream, buf, count);
    }
 
    if (bytes) {
        stream->flags |= PHP_STREAM_FLAG_WAS_WRITTEN;
    }
 
    return bytes;
}
 
PHPAPI ssize_t _php_stream_printf(php_stream *stream, const char *fmt, ...)
{
    ssize_t count;
    char *buf;
    va_list ap;
 
    va_start(ap, fmt);
    count = vspprintf(&buf, 0, fmt, ap);
    va_end(ap);
 
    if (!buf) {
        return -1; /* error condition */
    }
 
    count = php_stream_write(stream, buf, count);
    efree(buf);
 
    return count;
}
 
PHPAPI zend_off_t _php_stream_tell(php_stream *stream)
{
    return stream->position;
}
 
PHPAPI int _php_stream_seek(php_stream *stream, zend_off_t offset, int whence)
{
    if (stream->fclose_stdiocast == PHP_STREAM_FCLOSE_FOPENCOOKIE) {
        /* flush can call seek internally so we need to prevent an infinite loop */
        if (!stream->fclose_stdiocast_flush_in_progress) {
            stream->fclose_stdiocast_flush_in_progress = 1;
            /* flush to commit data written to the fopencookie FILE* */
            fflush(stream->stdiocast);
            stream->fclose_stdiocast_flush_in_progress = 0;
        }
    }
 
    /* handle the case where we are in the buffer */
    if ((stream->flags & PHP_STREAM_FLAG_NO_BUFFER) == 0) {
        switch(whence) {
            case SEEK_CUR:
                if (offset > 0 && offset <= stream->writepos - stream->readpos) {
                    stream->readpos += offset; /* if offset = ..., then readpos = writepos */
                    stream->position += offset;
                    stream->eof = 0;
                    return 0;
                }
                break;
            case SEEK_SET:
                if (offset > stream->position &&
                        offset <= stream->position + stream->writepos - stream->readpos) {
                    stream->readpos += offset - stream->position;
                    stream->position = offset;
                    stream->eof = 0;
                    return 0;
                }
                break;
        }
    }
 
 
    if (stream->ops->seek && (stream->flags & PHP_STREAM_FLAG_NO_SEEK) == 0) {
        int ret;
 
        if (stream->writefilters.head) {
            _php_stream_flush(stream, 0);
        }
 
        switch(whence) {
            case SEEK_CUR:
                ZEND_ASSERT(stream->position >= 0);
                if (UNEXPECTED(offset > ZEND_LONG_MAX - stream->position)) {
                    offset = ZEND_LONG_MAX;
                } else {
                    offset = stream->position + offset;
                }
                whence = SEEK_SET;
                break;
            case SEEK_SET:
                if (offset < 0) {
                    return -1;
                }
        }
        ret = stream->ops->seek(stream, offset, whence, &stream->position);
 
        if (((stream->flags & PHP_STREAM_FLAG_NO_SEEK) == 0) || ret == 0) {
            if (ret == 0) {
                stream->eof = 0;
            }
 
            /* invalidate the buffer contents */
            stream->readpos = stream->writepos = 0;
 
            return ret;
        }
        /* else the stream has decided that it can't support seeking after all;
         * fall through to attempt emulation */
    }
 
    /* emulate forward moving seeks with reads */
    if (whence == SEEK_CUR && offset >= 0) {
        char tmp[1024];
        ssize_t didread;
        while (offset > 0) {
            if ((didread = php_stream_read(stream, tmp, MIN(offset, sizeof(tmp)))) <= 0) {
                return -1;
            }
            offset -= didread;
        }
        stream->eof = 0;
        return 0;
    }
 
    php_error_docref(NULL, E_WARNING, "Stream does not support seeking");
 
    return -1;
}
 
PHPAPI int _php_stream_set_option(php_stream *stream, int option, int value, void *ptrparam)
{
    int ret = PHP_STREAM_OPTION_RETURN_NOTIMPL;
 
    if (stream->ops->set_option) {
        ret = stream->ops->set_option(stream, option, value, ptrparam);
    }
 
    if (ret == PHP_STREAM_OPTION_RETURN_NOTIMPL) {
        switch(option) {
            case PHP_STREAM_OPTION_SET_CHUNK_SIZE:
                /* XXX chunk size itself is of size_t, that might be ok or not for a particular case*/
                ret = stream->chunk_size > INT_MAX ? INT_MAX : (int)stream->chunk_size;
                stream->chunk_size = value;
                return ret;
 
            case PHP_STREAM_OPTION_READ_BUFFER:
                /* try to match the buffer mode as best we can */
                if (value == PHP_STREAM_BUFFER_NONE) {
                    stream->flags |= PHP_STREAM_FLAG_NO_BUFFER;
                } else if (stream->flags & PHP_STREAM_FLAG_NO_BUFFER) {
                    stream->flags ^= PHP_STREAM_FLAG_NO_BUFFER;
                }
                ret = PHP_STREAM_OPTION_RETURN_OK;
                break;
 
            default:
                ;
        }
    }
 
    return ret;
}
 
PHPAPI int _php_stream_sync(php_stream *stream, bool data_only)
{
    int op = PHP_STREAM_SYNC_FSYNC;
    if (data_only) {
        op = PHP_STREAM_SYNC_FDSYNC;
    }
    return php_stream_set_option(stream, PHP_STREAM_OPTION_SYNC_API, op, NULL);
}
 
PHPAPI int _php_stream_truncate_set_size(php_stream *stream, size_t newsize)
{
    return php_stream_set_option(stream, PHP_STREAM_OPTION_TRUNCATE_API, PHP_STREAM_TRUNCATE_SET_SIZE, &newsize);
}
 
PHPAPI ssize_t _php_stream_passthru(php_stream * stream STREAMS_DC)
{
    size_t bcount = 0;
    char buf[8192];
    ssize_t b;
 
    if (php_stream_mmap_possible(stream)) {
        char *p;
        size_t mapped;
 
        p = php_stream_mmap_range(stream, php_stream_tell(stream), PHP_STREAM_MMAP_ALL, PHP_STREAM_MAP_MODE_SHARED_READONLY, &mapped);
 
        if (p) {
            do {
                /* output functions return int, so pass in int max */
                if (0 < (b = PHPWRITE(p + bcount, MIN(mapped - bcount, INT_MAX)))) {
                    bcount += b;
                }
            } while (b > 0 && mapped > bcount);
 
            php_stream_mmap_unmap_ex(stream, mapped);
 
            return bcount;
        }
    }
 
    while ((b = php_stream_read(stream, buf, sizeof(buf))) > 0) {
        PHPWRITE(buf, b);
        bcount += b;
    }
 
    if (b < 0 && bcount == 0) {
        return b;
    }
 
    return bcount;
}
 
 
PHPAPI zend_string *_php_stream_copy_to_mem(php_stream *src, size_t maxlen, int persistent STREAMS_DC)
{
    ssize_t ret = 0;
    char *ptr;
    size_t len = 0, buflen;
    int step = CHUNK_SIZE;
    int min_room = CHUNK_SIZE / 4;
    php_stream_statbuf ssbuf;
    zend_string *result;
 
    if (maxlen == 0) {
        return ZSTR_EMPTY_ALLOC();
    }
 
    if (maxlen == PHP_STREAM_COPY_ALL) {
        maxlen = 0;
    }
 
    if (maxlen > 0 && maxlen < 4 * CHUNK_SIZE) {
        result = zend_string_alloc(maxlen, persistent);
        ptr = ZSTR_VAL(result);
        while ((len < maxlen) && !php_stream_eof(src)) {
            ret = php_stream_read(src, ptr, maxlen - len);
            if (ret <= 0) {
                // TODO: Propagate error?
                break;
            }
            len += ret;
            ptr += ret;
        }
        if (len) {
            ZSTR_LEN(result) = len;
            ZSTR_VAL(result)[len] = '\0';
 
            /* Only truncate if the savings are large enough */
            if (len < maxlen / 2) {
                result = zend_string_truncate(result, len, persistent);
            }
        } else {
            zend_string_free(result);
            result = NULL;
        }
        return result;
    }
 
    /* avoid many reallocs by allocating a good-sized chunk to begin with, if
     * we can.  Note that the stream may be filtered, in which case the stat
     * result may be inaccurate, as the filter may inflate or deflate the
     * number of bytes that we can read.  In order to avoid an upsize followed
     * by a downsize of the buffer, overestimate by the step size (which is
     * 8K).  */
    if (php_stream_stat(src, &ssbuf) == 0 && ssbuf.sb.st_size > 0) {
        buflen = MAX(ssbuf.sb.st_size - src->position, 0) + step;
        if (maxlen > 0 && buflen > maxlen) {
            buflen = maxlen;
        }
    } else {
        buflen = step;
    }
 
    result = zend_string_alloc(buflen, persistent);
    ptr = ZSTR_VAL(result);
 
    // TODO: Propagate error?
    while ((ret = php_stream_read(src, ptr, buflen - len)) > 0) {
        len += ret;
        if (len + min_room >= buflen) {
            if (maxlen == len) {
                break;
            }
            if (maxlen > 0 && buflen + step > maxlen) {
                buflen = maxlen;
            } else {
                buflen += step;
            }
            result = zend_string_extend(result, buflen, persistent);
            ptr = ZSTR_VAL(result) + len;
        } else {
            ptr += ret;
        }
    }
    if (len) {
        result = zend_string_truncate(result, len, persistent);
        ZSTR_VAL(result)[len] = '\0';
    } else {
        zend_string_free(result);
        result = NULL;
    }
 
    return result;
}
 
/* Returns SUCCESS/FAILURE and sets *len to the number of bytes moved */
PHPAPI zend_result _php_stream_copy_to_stream_ex(php_stream *src, php_stream *dest, size_t maxlen, size_t *len STREAMS_DC)
{
    char buf[CHUNK_SIZE];
    size_t haveread = 0;
    size_t towrite;
    size_t dummy;
 
    if (!len) {
        len = &dummy;
    }
 
    if (maxlen == 0) {
        *len = 0;
        return SUCCESS;
    }
 
#ifdef HAVE_COPY_FILE_RANGE
    if (php_stream_is(src, PHP_STREAM_IS_STDIO) &&
            php_stream_is(dest, PHP_STREAM_IS_STDIO) &&
            src->writepos == src->readpos) {
        /* both php_stream instances are backed by a file descriptor, are not filtered and the
         * read buffer is empty: we can use copy_file_range() */
        int src_fd, dest_fd, dest_open_flags = 0;
 
        /* copy_file_range does not work with O_APPEND */
        if (php_stream_cast(src, PHP_STREAM_AS_FD, (void*)&src_fd, 0) == SUCCESS &&
                php_stream_cast(dest, PHP_STREAM_AS_FD, (void*)&dest_fd, 0) == SUCCESS &&
                /* get dest open flags to check if the stream is open in append mode */
                php_stream_parse_fopen_modes(dest->mode, &dest_open_flags) == SUCCESS &&
                !(dest_open_flags & O_APPEND)) {
 
            /* clamp to INT_MAX to avoid EOVERFLOW */
            const size_t cfr_max = MIN(maxlen, (size_t)SSIZE_MAX);
 
            /* copy_file_range() is a Linux-specific system call which allows efficient copying
             * between two file descriptors, eliminating the need to transfer data from the kernel
             * to userspace and back. For networking file systems like NFS and Ceph, it even
             * eliminates copying data to the client, and local filesystems like Btrfs and XFS can
             * create shared extents. */
            ssize_t result = copy_file_range(src_fd, NULL, dest_fd, NULL, cfr_max, 0);
            if (result > 0) {
                size_t nbytes = (size_t)result;
                haveread += nbytes;
 
                src->position += nbytes;
                dest->position += nbytes;
 
                if ((maxlen != PHP_STREAM_COPY_ALL && nbytes == maxlen) || php_stream_eof(src)) {
                    /* the whole request was satisfied or end-of-file reached - done */
                    *len = haveread;
                    return SUCCESS;
                }
 
                /* there may be more data; continue copying using the fallback code below */
            } else if (result == 0) {
                /* end of file */
                *len = haveread;
                return SUCCESS;
            } else if (result < 0) {
                switch (errno) {
                    case EINVAL:
                        /* some formal error, e.g. overlapping file ranges */
                        break;
 
                    case EXDEV:
                        /* pre Linux 5.3 error */
                        break;
 
                    case ENOSYS:
                        /* not implemented by this Linux kernel */
                        break;
 
                    case EIO:
                        /* Some filesystems will cause failures if the max length is greater than the file length
                         * in certain circumstances and configuration. In those cases the errno is EIO and we will
                         * fall back to other methods. We cannot use stat to determine the file length upfront because
                         * that is prone to races and outdated caching. */
                        break;
 
                    default:
                        /* unexpected I/O error - give up, no fallback */
                        *len = haveread;
                        return FAILURE;
                }
 
                /* fall back to classic copying */
            }
        }
    }
#endif // HAVE_COPY_FILE_RANGE
 
    if (maxlen == PHP_STREAM_COPY_ALL) {
        maxlen = 0;
    }
 
    if (php_stream_mmap_possible(src)) {
        char *p;
 
        do {
            /* We must not modify maxlen here, because otherwise the file copy fallback below can fail */
            size_t chunk_size, must_read, mapped;
            if (maxlen == 0) {
                /* Unlimited read */
                must_read = chunk_size = PHP_STREAM_MMAP_MAX;
            } else {
                must_read = maxlen - haveread;
                if (must_read >= PHP_STREAM_MMAP_MAX) {
                    chunk_size = PHP_STREAM_MMAP_MAX;
                } else {
                    /* In case the length we still have to read from the file could be smaller than the file size,
                     * chunk_size must not get bigger the size we're trying to read. */
                    chunk_size = must_read;
                }
            }
 
            p = php_stream_mmap_range(src, php_stream_tell(src), chunk_size, PHP_STREAM_MAP_MODE_SHARED_READONLY, &mapped);
 
            if (p) {
                ssize_t didwrite;
 
                if (php_stream_seek(src, mapped, SEEK_CUR) != 0) {
                    php_stream_mmap_unmap(src);
                    break;
                }
 
                didwrite = php_stream_write(dest, p, mapped);
                if (didwrite < 0) {
                    *len = haveread;
                    php_stream_mmap_unmap(src);
                    return FAILURE;
                }
 
                php_stream_mmap_unmap(src);
 
                *len = haveread += didwrite;
 
                /* we've got at least 1 byte to read
                 * less than 1 is an error
                 * AND read bytes match written */
                if (mapped == 0 || mapped != didwrite) {
                    return FAILURE;
                }
                if (mapped < chunk_size) {
                    return SUCCESS;
                }
                /* If we're not reading as much as possible, so a bounded read */
                if (maxlen != 0) {
                    must_read -= mapped;
                    if (must_read == 0) {
                        return SUCCESS;
                    }
                }
            }
        } while (p);
    }
 
    while(1) {
        size_t readchunk = sizeof(buf);
        ssize_t didread;
        char *writeptr;
 
        if (maxlen && (maxlen - haveread) < readchunk) {
            readchunk = maxlen - haveread;
        }
 
        didread = php_stream_read(src, buf, readchunk);
        if (didread <= 0) {
            *len = haveread;
            return didread < 0 ? FAILURE : SUCCESS;
        }
 
        towrite = didread;
        writeptr = buf;
        haveread += didread;
 
        while (towrite) {
            ssize_t didwrite = php_stream_write(dest, writeptr, towrite);
            if (didwrite <= 0) {
                *len = haveread - (didread - towrite);
                return FAILURE;
            }
 
            towrite -= didwrite;
            writeptr += didwrite;
        }
 
        if (maxlen && maxlen == haveread) {
            break;
        }
    }
 
    *len = haveread;
    return SUCCESS;
}
 
/* Returns the number of bytes moved.
 * Returns 1 when source len is 0.
 * Deprecated in favor of php_stream_copy_to_stream_ex() */
ZEND_ATTRIBUTE_DEPRECATED
PHPAPI size_t _php_stream_copy_to_stream(php_stream *src, php_stream *dest, size_t maxlen STREAMS_DC)
{
    size_t len;
    zend_result ret = _php_stream_copy_to_stream_ex(src, dest, maxlen, &len STREAMS_REL_CC);
    if (ret == SUCCESS && len == 0 && maxlen != 0) {
        return 1;
    }
    return len;
}
/* }}} */
 
/* {{{ wrapper init and registration */
 
static void stream_resource_regular_dtor(zend_resource *rsrc)
{
    php_stream *stream = (php_stream*)rsrc->ptr;
    /* set the return value for pclose */
    FG(pclose_ret) = php_stream_free(stream, PHP_STREAM_FREE_CLOSE | PHP_STREAM_FREE_RSRC_DTOR);
}
 
static void stream_resource_persistent_dtor(zend_resource *rsrc)
{
    php_stream *stream = (php_stream*)rsrc->ptr;
    FG(pclose_ret) = php_stream_free(stream, PHP_STREAM_FREE_CLOSE | PHP_STREAM_FREE_RSRC_DTOR);
}
 
void php_shutdown_stream_hashes(void)
{
    FG(user_stream_current_filename) = NULL;
    if (FG(stream_wrappers)) {
        zend_hash_destroy(FG(stream_wrappers));
        efree(FG(stream_wrappers));
        FG(stream_wrappers) = NULL;
    }
 
    if (FG(stream_filters)) {
        zend_hash_destroy(FG(stream_filters));
        efree(FG(stream_filters));
        FG(stream_filters) = NULL;
    }
 
    if (FG(wrapper_errors)) {
        zend_hash_destroy(FG(wrapper_errors));
        efree(FG(wrapper_errors));
        FG(wrapper_errors) = NULL;
    }
}
 
int php_init_stream_wrappers(int module_number)
{
    le_stream = zend_register_list_destructors_ex(stream_resource_regular_dtor, NULL, "stream", module_number);
    le_pstream = zend_register_list_destructors_ex(NULL, stream_resource_persistent_dtor, "persistent stream", module_number);
 
    /* Filters are cleaned up by the streams they're attached to */
    le_stream_filter = zend_register_list_destructors_ex(NULL, NULL, "stream filter", module_number);
 
    zend_hash_init(&url_stream_wrappers_hash, 8, NULL, NULL, 1);
    zend_hash_init(php_get_stream_filters_hash_global(), 8, NULL, NULL, 1);
    zend_hash_init(php_stream_xport_get_hash(), 8, NULL, NULL, 1);
 
    return (php_stream_xport_register("tcp", php_stream_generic_socket_factory) == SUCCESS
            &&
            php_stream_xport_register("udp", php_stream_generic_socket_factory) == SUCCESS
#if defined(AF_UNIX) && !(defined(PHP_WIN32) || defined(__riscos__))
            &&
            php_stream_xport_register("unix", php_stream_generic_socket_factory) == SUCCESS
            &&
            php_stream_xport_register("udg", php_stream_generic_socket_factory) == SUCCESS
#endif
        ) ? SUCCESS : FAILURE;
}
 
void php_shutdown_stream_wrappers(int module_number)
{
    zend_hash_destroy(&url_stream_wrappers_hash);
    zend_hash_destroy(php_get_stream_filters_hash_global());
    zend_hash_destroy(php_stream_xport_get_hash());
}
 
/* Validate protocol scheme names during registration
 * Must conform to /^[a-zA-Z0-9+.-]+$/
 */
static inline zend_result php_stream_wrapper_scheme_validate(const char *protocol, unsigned int protocol_len)
{
    unsigned int i;
 
    for(i = 0; i < protocol_len; i++) {
        if (!isalnum((int)protocol[i]) &&
            protocol[i] != '+' &&
            protocol[i] != '-' &&
            protocol[i] != '.') {
            return FAILURE;
        }
    }
 
    return SUCCESS;
}
 
/* API for registering GLOBAL wrappers */
PHPAPI zend_result php_register_url_stream_wrapper(const char *protocol, const php_stream_wrapper *wrapper)
{
    size_t protocol_len = strlen(protocol);
    zend_result ret;
    zend_string *str;
 
    if (php_stream_wrapper_scheme_validate(protocol, protocol_len) == FAILURE) {
        return FAILURE;
    }
 
    str = zend_string_init_interned(protocol, protocol_len, 1);
    ret = zend_hash_add_ptr(&url_stream_wrappers_hash, str, (void*)wrapper) ? SUCCESS : FAILURE;
    zend_string_release_ex(str, 1);
    return ret;
}
 
PHPAPI zend_result php_unregister_url_stream_wrapper(const char *protocol)
{
    return zend_hash_str_del(&url_stream_wrappers_hash, protocol, strlen(protocol));
}
 
static void clone_wrapper_hash(void)
{
    ALLOC_HASHTABLE(FG(stream_wrappers));
    zend_hash_init(FG(stream_wrappers), zend_hash_num_elements(&url_stream_wrappers_hash), NULL, NULL, 0);
    zend_hash_copy(FG(stream_wrappers), &url_stream_wrappers_hash, NULL);
}
 
/* API for registering VOLATILE wrappers */
PHPAPI zend_result php_register_url_stream_wrapper_volatile(zend_string *protocol, php_stream_wrapper *wrapper)
{
    if (php_stream_wrapper_scheme_validate(ZSTR_VAL(protocol), ZSTR_LEN(protocol)) == FAILURE) {
        return FAILURE;
    }
 
    if (!FG(stream_wrappers)) {
        clone_wrapper_hash();
    }
 
    return zend_hash_add_ptr(FG(stream_wrappers), protocol, wrapper) ? SUCCESS : FAILURE;
}
 
PHPAPI zend_result php_unregister_url_stream_wrapper_volatile(zend_string *protocol)
{
    if (!FG(stream_wrappers)) {
        clone_wrapper_hash();
    }
 
    return zend_hash_del(FG(stream_wrappers), protocol);
}
/* }}} */
 
/* {{{ php_stream_locate_url_wrapper */
PHPAPI php_stream_wrapper *php_stream_locate_url_wrapper(const char *path, const char **path_for_open, int options)
{
    HashTable *wrapper_hash = (FG(stream_wrappers) ? FG(stream_wrappers) : &url_stream_wrappers_hash);
    php_stream_wrapper *wrapper = NULL;
    const char *p, *protocol = NULL;
    size_t n = 0;
 
    if (path_for_open) {
        *path_for_open = (char*)path;
    }
 
    if (options & IGNORE_URL) {
        return (php_stream_wrapper*)((options & STREAM_LOCATE_WRAPPERS_ONLY) ? NULL : &php_plain_files_wrapper);
    }
 
    for (p = path; isalnum((int)*p) || *p == '+' || *p == '-' || *p == '.'; p++) {
        n++;
    }
 
    if ((*p == ':') && (n > 1) && (!strncmp("//", p+1, 2) || (n == 4 && !memcmp("data:", path, 5)))) {
        protocol = path;
    }
 
    if (protocol) {
        if (NULL == (wrapper = zend_hash_str_find_ptr(wrapper_hash, protocol, n))) {
            char *tmp = estrndup(protocol, n);
 
            zend_str_tolower(tmp, n);
            if (NULL == (wrapper = zend_hash_str_find_ptr(wrapper_hash, tmp, n))) {
                char wrapper_name[32];
 
                if (n >= sizeof(wrapper_name)) {
                    n = sizeof(wrapper_name) - 1;
                }
                PHP_STRLCPY(wrapper_name, protocol, sizeof(wrapper_name), n);
 
                php_error_docref(NULL, E_WARNING, "Unable to find the wrapper \"%s\" - did you forget to enable it when you configured PHP?", wrapper_name);
 
                wrapper = NULL;
                protocol = NULL;
            }
            efree(tmp);
        }
    }
    /* TODO: curl based streams probably support file:// properly */
    if (!protocol || !strncasecmp(protocol, "file", n)) {
        /* fall back on regular file access */
        php_stream_wrapper *plain_files_wrapper = (php_stream_wrapper*)&php_plain_files_wrapper;
 
        if (protocol) {
            int localhost = 0;
 
            if (!strncasecmp(path, "file://localhost/", 17)) {
                localhost = 1;
            }
 
#ifdef PHP_WIN32
            if (localhost == 0 && path[n+3] != '\0' && path[n+3] != '/' && path[n+4] != ':') {
#else
            if (localhost == 0 && path[n+3] != '\0' && path[n+3] != '/') {
#endif
                if (options & REPORT_ERRORS) {
                    php_error_docref(NULL, E_WARNING, "Remote host file access not supported, %s", path);
                }
                return NULL;
            }
 
            if (path_for_open) {
                /* skip past protocol and :/, but handle windows correctly */
                *path_for_open = (char*)path + n + 1;
                if (localhost == 1) {
                    (*path_for_open) += 11;
                }
                while (*(++*path_for_open)=='/') {
                    /* intentionally empty */
                }
#ifdef PHP_WIN32
                if (*(*path_for_open + 1) != ':')
#endif
                    (*path_for_open)--;
            }
        }
 
        if (options & STREAM_LOCATE_WRAPPERS_ONLY) {
            return NULL;
        }
 
        if (FG(stream_wrappers)) {
        /* The file:// wrapper may have been disabled/overridden */
 
            if (wrapper) {
                /* It was found so go ahead and provide it */
                return wrapper;
            }
 
            /* Check again, the original check might have not known the protocol name */
            if ((wrapper = zend_hash_find_ex_ptr(wrapper_hash, ZSTR_KNOWN(ZEND_STR_FILE), 1)) != NULL) {
                return wrapper;
            }
 
            if (options & REPORT_ERRORS) {
                php_error_docref(NULL, E_WARNING, "file:// wrapper is disabled in the server configuration");
            }
            return NULL;
        }
 
        return plain_files_wrapper;
    }
 
    if (wrapper && wrapper->is_url &&
        (options & STREAM_DISABLE_URL_PROTECTION) == 0 &&
        (!PG(allow_url_fopen) ||
         (((options & STREAM_OPEN_FOR_INCLUDE) ||
           PG(in_user_include)) && !PG(allow_url_include)))) {
        if (options & REPORT_ERRORS) {
            /* protocol[n] probably isn't '\0' */
            if (!PG(allow_url_fopen)) {
                php_error_docref(NULL, E_WARNING, "%.*s:// wrapper is disabled in the server configuration by allow_url_fopen=0", (int)n, protocol);
            } else {
                php_error_docref(NULL, E_WARNING, "%.*s:// wrapper is disabled in the server configuration by allow_url_include=0", (int)n, protocol);
            }
        }
        return NULL;
    }
 
    return wrapper;
}
/* }}} */
 
/* {{{ _php_stream_mkdir */
PHPAPI int _php_stream_mkdir(const char *path, int mode, int options, php_stream_context *context)
{
    php_stream_wrapper *wrapper = NULL;
 
    wrapper = php_stream_locate_url_wrapper(path, NULL, 0);
    if (!wrapper || !wrapper->wops || !wrapper->wops->stream_mkdir) {
        return 0;
    }
 
    return wrapper->wops->stream_mkdir(wrapper, path, mode, options, context);
}
/* }}} */
 
/* {{{ _php_stream_rmdir */
PHPAPI int _php_stream_rmdir(const char *path, int options, php_stream_context *context)
{
    php_stream_wrapper *wrapper = NULL;
 
    wrapper = php_stream_locate_url_wrapper(path, NULL, 0);
    if (!wrapper || !wrapper->wops || !wrapper->wops->stream_rmdir) {
        return 0;
    }
 
    return wrapper->wops->stream_rmdir(wrapper, path, options, context);
}
/* }}} */
 
/* {{{ _php_stream_stat_path */
PHPAPI int _php_stream_stat_path(const char *path, int flags, php_stream_statbuf *ssb, php_stream_context *context)
{
    php_stream_wrapper *wrapper = NULL;
    const char *path_to_open = path;
 
    memset(ssb, 0, sizeof(*ssb));
 
    wrapper = php_stream_locate_url_wrapper(path, &path_to_open, 0);
    if (wrapper && wrapper->wops->url_stat) {
        return wrapper->wops->url_stat(wrapper, path_to_open, flags, ssb, context);
    }
    return -1;
}
/* }}} */
 
/* {{{ php_stream_opendir */
PHPAPI php_stream *_php_stream_opendir(const char *path, int options,
        php_stream_context *context STREAMS_DC)
{
    php_stream *stream = NULL;
    php_stream_wrapper *wrapper = NULL;
    const char *path_to_open;
 
    if (!path || !*path) {
        return NULL;
    }
 
    path_to_open = path;
 
    wrapper = php_stream_locate_url_wrapper(path, &path_to_open, options);
 
    if (wrapper && wrapper->wops->dir_opener) {
        stream = wrapper->wops->dir_opener(wrapper,
                path_to_open, "r", options & ~REPORT_ERRORS, NULL,
                context STREAMS_REL_CC);
 
        if (stream) {
            stream->wrapper = wrapper;
            stream->flags |= PHP_STREAM_FLAG_NO_BUFFER | PHP_STREAM_FLAG_IS_DIR;
        }
    } else if (wrapper) {
        php_stream_wrapper_log_error(wrapper, options & ~REPORT_ERRORS, "not implemented");
    }
    if (stream == NULL && (options & REPORT_ERRORS)) {
        php_stream_display_wrapper_errors(wrapper, path, "Failed to open directory");
    }
    php_stream_tidy_wrapper_error_log(wrapper);
 
    return stream;
}
/* }}} */
 
/* {{{ _php_stream_readdir */
PHPAPI php_stream_dirent *_php_stream_readdir(php_stream *dirstream, php_stream_dirent *ent)
{
 
    if (sizeof(php_stream_dirent) == php_stream_read(dirstream, (char*)ent, sizeof(php_stream_dirent))) {
        return ent;
    }
 
    return NULL;
}
/* }}} */
 
/* {{{ php_stream_open_wrapper_ex */
PHPAPI php_stream *_php_stream_open_wrapper_ex(const char *path, const char *mode, int options,
        zend_string **opened_path, php_stream_context *context STREAMS_DC)
{
    php_stream *stream = NULL;
    php_stream_wrapper *wrapper = NULL;
    const char *path_to_open;
    int persistent = options & STREAM_OPEN_PERSISTENT;
    zend_string *path_str = NULL;
    zend_string *resolved_path = NULL;
    char *copy_of_path = NULL;
 
    if (opened_path) {
        if (options & STREAM_OPEN_FOR_ZEND_STREAM) {
            path_str = *opened_path;
        }
        *opened_path = NULL;
    }
 
    if (!path || !*path) {
        zend_value_error("Path must not be empty");
        return NULL;
    }
 
    if (options & USE_PATH) {
        if (path_str) {
            resolved_path = zend_resolve_path(path_str);
        } else {
            resolved_path = php_resolve_path(path, strlen(path), PG(include_path));
        }
        if (resolved_path) {
            path = ZSTR_VAL(resolved_path);
            /* we've found this file, don't re-check include_path or run realpath */
            options |= STREAM_ASSUME_REALPATH;
            options &= ~USE_PATH;
        }
        if (EG(exception)) {
            if (resolved_path) {
                zend_string_release_ex(resolved_path, false);
            }
            return NULL;
        }
    }
 
    path_to_open = path;
 
    wrapper = php_stream_locate_url_wrapper(path, &path_to_open, options);
    if ((options & STREAM_USE_URL) && (!wrapper || !wrapper->is_url)) {
        php_error_docref(NULL, E_WARNING, "This function may only be used against URLs");
        if (resolved_path) {
            zend_string_release_ex(resolved_path, 0);
        }
        return NULL;
    }
 
    if (wrapper) {
        if (!wrapper->wops->stream_opener) {
            php_stream_wrapper_log_error(wrapper, options & ~REPORT_ERRORS,
                    "wrapper does not support stream open");
        } else {
            stream = wrapper->wops->stream_opener(wrapper,
                path_to_open, mode, options & ~REPORT_ERRORS,
                opened_path, context STREAMS_REL_CC);
        }
 
        /* if the caller asked for a persistent stream but the wrapper did not
         * return one, force an error here */
        if (stream && (options & STREAM_OPEN_PERSISTENT) && !stream->is_persistent) {
            php_stream_wrapper_log_error(wrapper, options & ~REPORT_ERRORS,
                    "wrapper does not support persistent streams");
            php_stream_close(stream);
            stream = NULL;
        }
 
        if (stream) {
            stream->wrapper = wrapper;
        }
    }
 
    if (stream) {
        if (opened_path && !*opened_path && resolved_path) {
            *opened_path = resolved_path;
            resolved_path = NULL;
        }
        if (stream->orig_path) {
            pefree(stream->orig_path, persistent);
        }
        copy_of_path = pestrdup(path, persistent);
        stream->orig_path = copy_of_path;
#if ZEND_DEBUG
        stream->open_filename = __zend_orig_filename ? __zend_orig_filename : __zend_filename;
        stream->open_lineno = __zend_orig_lineno ? __zend_orig_lineno : __zend_lineno;
#endif
    }
 
    if (stream != NULL && (options & STREAM_MUST_SEEK)) {
        php_stream *newstream;
 
        switch(php_stream_make_seekable_rel(stream, &newstream,
                    (options & STREAM_WILL_CAST)
                        ? PHP_STREAM_PREFER_STDIO : PHP_STREAM_NO_PREFERENCE)) {
            case PHP_STREAM_UNCHANGED:
                if (resolved_path) {
                    zend_string_release_ex(resolved_path, 0);
                }
                return stream;
            case PHP_STREAM_RELEASED:
                if (newstream->orig_path) {
                    pefree(newstream->orig_path, persistent);
                }
                newstream->orig_path = pestrdup(path, persistent);
                if (resolved_path) {
                    zend_string_release_ex(resolved_path, 0);
                }
                return newstream;
            default:
                php_stream_close(stream);
                stream = NULL;
                if (options & REPORT_ERRORS) {
                    char *tmp = estrdup(path);
                    php_strip_url_passwd(tmp);
                    php_error_docref1(NULL, tmp, E_WARNING, "could not make seekable - %s",
                            tmp);
                    efree(tmp);
 
                    options &= ~REPORT_ERRORS;
                }
        }
    }
 
    if (stream && stream->ops->seek && (stream->flags & PHP_STREAM_FLAG_NO_SEEK) == 0 && strchr(mode, 'a') && stream->position == 0) {
        zend_off_t newpos = 0;
 
        /* if opened for append, we need to revise our idea of the initial file position */
        if (0 == stream->ops->seek(stream, 0, SEEK_CUR, &newpos)) {
            stream->position = newpos;
        }
    }
 
    if (stream == NULL && (options & REPORT_ERRORS)) {
        php_stream_display_wrapper_errors(wrapper, path, "Failed to open stream");
        if (opened_path && *opened_path) {
            zend_string_release_ex(*opened_path, 0);
            *opened_path = NULL;
        }
    }
    php_stream_tidy_wrapper_error_log(wrapper);
#if ZEND_DEBUG
    if (stream == NULL && copy_of_path != NULL) {
        pefree(copy_of_path, persistent);
    }
#endif
    if (resolved_path) {
        zend_string_release_ex(resolved_path, 0);
    }
    return stream;
}
/* }}} */
 
/* {{{ context API */
PHPAPI php_stream_context *php_stream_context_set(php_stream *stream, php_stream_context *context)
{
    php_stream_context *oldcontext = PHP_STREAM_CONTEXT(stream);
 
    if (context) {
        stream->ctx = context->res;
        GC_ADDREF(context->res);
    } else {
        stream->ctx = NULL;
    }
    if (oldcontext) {
        zend_list_delete(oldcontext->res);
    }
 
    return oldcontext;
}
 
PHPAPI void php_stream_notification_notify(php_stream_context *context, int notifycode, int severity,
        char *xmsg, int xcode, size_t bytes_sofar, size_t bytes_max, void * ptr)
{
    if (context && context->notifier)
        context->notifier->func(context, notifycode, severity, xmsg, xcode, bytes_sofar, bytes_max, ptr);
}
 
PHPAPI void php_stream_context_free(php_stream_context *context)
{
    if (Z_TYPE(context->options) != IS_UNDEF) {
        zval_ptr_dtor(&context->options);
        ZVAL_UNDEF(&context->options);
    }
    if (context->notifier) {
        php_stream_notification_free(context->notifier);
        context->notifier = NULL;
    }
    efree(context);
}
 
PHPAPI php_stream_context *php_stream_context_alloc(void)
{
    php_stream_context *context;
 
    context = ecalloc(1, sizeof(php_stream_context));
    array_init(&context->options);
 
    context->res = zend_register_resource(context, php_le_stream_context());
    return context;
}
 
PHPAPI php_stream_notifier *php_stream_notification_alloc(void)
{
    return ecalloc(1, sizeof(php_stream_notifier));
}
 
PHPAPI void php_stream_notification_free(php_stream_notifier *notifier)
{
    if (notifier->dtor) {
        notifier->dtor(notifier);
    }
    efree(notifier);
}
 
PHPAPI zval *php_stream_context_get_option(php_stream_context *context,
        const char *wrappername, const char *optionname)
{
    zval *wrapperhash;
 
    if (NULL == (wrapperhash = zend_hash_str_find(Z_ARRVAL(context->options), wrappername, strlen(wrappername)))) {
        return NULL;
    }
    return zend_hash_str_find(Z_ARRVAL_P(wrapperhash), optionname, strlen(optionname));
}
 
PHPAPI void php_stream_context_set_option(php_stream_context *context,
        const char *wrappername, const char *optionname, zval *optionvalue)
{
    zval *wrapperhash;
    zval category;
 
    SEPARATE_ARRAY(&context->options);
    wrapperhash = zend_hash_str_find(Z_ARRVAL(context->options), wrappername, strlen(wrappername));
    if (NULL == wrapperhash) {
        array_init(&category);
        wrapperhash = zend_hash_str_update(Z_ARRVAL(context->options), (char*)wrappername, strlen(wrappername), &category);
    }
    ZVAL_DEREF(optionvalue);
    Z_TRY_ADDREF_P(optionvalue);
    SEPARATE_ARRAY(wrapperhash);
    zend_hash_str_update(Z_ARRVAL_P(wrapperhash), optionname, strlen(optionname), optionvalue);
}
/* }}} */
 
/* {{{ php_stream_dirent_alphasort */
PHPAPI int php_stream_dirent_alphasort(const zend_string **a, const zend_string **b)
{
    return strcoll(ZSTR_VAL(*a), ZSTR_VAL(*b));
}
/* }}} */
 
/* {{{ php_stream_dirent_alphasortr */
PHPAPI int php_stream_dirent_alphasortr(const zend_string **a, const zend_string **b)
{
    return strcoll(ZSTR_VAL(*b), ZSTR_VAL(*a));
}
/* }}} */
 
/* {{{ php_stream_scandir */
PHPAPI int _php_stream_scandir(const char *dirname, zend_string **namelist[], int flags, php_stream_context *context,
              int (*compare) (const zend_string **a, const zend_string **b))
{
    php_stream *stream;
    php_stream_dirent sdp;
    zend_string **vector = NULL;
    unsigned int vector_size = 0;
    unsigned int nfiles = 0;
 
    if (!namelist) {
        return -1;
    }
 
    stream = php_stream_opendir(dirname, REPORT_ERRORS, context);
    if (!stream) {
        return -1;
    }
 
    while (php_stream_readdir(stream, &sdp)) {
        if (nfiles == vector_size) {
            if (vector_size == 0) {
                vector_size = 10;
            } else {
                if(vector_size*2 < vector_size) {
                    goto overflow;
                }
                vector_size *= 2;
            }
            vector = (zend_string **) safe_erealloc(vector, vector_size, sizeof(zend_string *), 0);
        }
 
        vector[nfiles] = zend_string_init(sdp.d_name, strlen(sdp.d_name), 0);
 
        if(vector_size < 10 || nfiles + 1 == 0) {
            goto overflow;
        }
        nfiles++;
    }
    php_stream_closedir(stream);
 
    *namelist = vector;
 
    if (nfiles > 0 && compare) {
        qsort(*namelist, nfiles, sizeof(zend_string *), (int(*)(const void *, const void *))compare);
    }
    return nfiles;
 
overflow:
    php_stream_closedir(stream);
    for (unsigned int i = 0; i < nfiles; i++) {
        zend_string_efree(vector[i]);
    }
    efree(vector);
    return -1;
}
/* }}} */