/src/php-src/main/streams/streams.c

Source
/*
   +----------------------------------------------------------------------+
   | Copyright © The PHP Group and Contributors.                          |
   +----------------------------------------------------------------------+
   | This source file is subject to the Modified BSD License that is      |
   | bundled with this package in the file LICENSE, and is available      |
   | through the World Wide Web at <https://www.php.net/license/>.        |
   |                                                                      |
   | SPDX-License-Identifier: BSD-3-Clause                                |
   +----------------------------------------------------------------------+
   | 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 "ext/uri/php_uri.h"
#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 = -1; /* true global */
static int le_pstream = -1; /* true global */
static int le_stream_filter = -1; /* 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->flags |= PHP_STREAM_FLAG_NO_FCLOSE;
  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;
}

/* }}} */

/* 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->error_list) {
      zend_llist_destroy(stream->error_list);
      pefree(stream->error_list, stream->is_persistent);
    }

    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 */

          /* Filter could have added buckets anyway, but signalled that it did not return any. Discard them. */
          while ((bucket = brig_outp->head)) {
            php_stream_bucket_unlink(bucket);
            php_stream_bucket_delref(bucket);
          }
          break;

        case PSFS_ERR_FATAL:
          /* some fatal error. Theoretically, the stream is borked, so all
           * further reads should fail. */
          stream->eof = 1;
          stream->fatal_error = 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 *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) {
    const char *cr = memchr(readptr, '\r', avail);
    const char *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;
        }
      }

      if (php_stream_fill_read_buffer(stream, toread) == FAILURE && stream->fatal_error) {
        if (grow_mode) {
          efree(bufstart);
        }
        return NULL;
      }

      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(
  const 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);

    if (php_stream_fill_read_buffer(stream, buffered_len + to_read_now) == FAILURE && stream->fatal_error) {
      return NULL;
    }

    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;
  php_stream_filter_status_t status = PSFS_ERR_FATAL;

  if (buf) {
    bucket = php_stream_bucket_new(stream, (char *)buf, count, 0, 0);
    php_stream_bucket_append(&brig_in, bucket);
  }

  for (php_stream_filter *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 */
    php_stream_bucket_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_ERR_FATAL:
      /* some fatal error.  Theoretically, the stream is borked, so all
       * further writes should fail. */
      consumed = (ssize_t) -1;
      ZEND_FALLTHROUGH;

    case PSFS_FEED_ME:
      /* need more data before we can push data through to the stream */
      /* Filter could have added buckets anyway, but signalled that it did not return any. Discard them. */
      while (brig_inp->head) {
        bucket = brig_inp->head;
        php_stream_bucket_unlink(bucket);
        php_stream_bucket_delref(bucket);
      }
      break;
  }

  return consumed;
}

PHPAPI int _php_stream_flush(php_stream *stream, int closing)
{
  int ret = 0;

  if (stream->writefilters.head && stream->ops->write) {
    _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_stream_notice(stream, NotWritable, "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(const php_stream *stream)
{
  return stream->position;
}

static bool php_stream_are_filters_seekable(php_stream_filter *filter, bool is_start_seeking, int chain_type)
{
  while (filter) {
    php_stream_filter_seekable_t seekable = (chain_type == PHP_STREAM_FILTER_READ) ?
        filter->read_seekable : filter->write_seekable;
    if (seekable == PSFS_SEEKABLE_NEVER) {
      php_error_docref(NULL, E_WARNING, "Stream filter %s is never seekable", filter->fops->label);
      return false;
    }
    if (!is_start_seeking && seekable == PSFS_SEEKABLE_START) {
      php_error_docref(NULL, E_WARNING, "Stream filter %s is seekable only to start position", filter->fops->label);
      return false;
    }
    filter = filter->next;
  }
  return true;
}

static zend_result php_stream_filters_seek(php_stream *stream, php_stream_filter *filter,
    bool is_start_seeking, zend_off_t offset, int whence, int chain_type)
{
  while (filter) {
    php_stream_filter_seekable_t seekable = (chain_type == PHP_STREAM_FILTER_READ) ?
        filter->read_seekable : filter->write_seekable;
    if (((seekable == PSFS_SEEKABLE_START && is_start_seeking) ||
        seekable == PSFS_SEEKABLE_CHECK) &&
        filter->fops->seek(stream, filter, offset, whence) == FAILURE) {
      php_error_docref(NULL, E_WARNING, "Stream filter seeking for %s failed", filter->fops->label);
      return FAILURE;
    }
    filter = filter->next;
  }
  return SUCCESS;
}

static zend_result php_stream_filters_seek_all(php_stream *stream, bool is_start_seeking,
    zend_off_t offset, int whence)
{
  if (php_stream_filters_seek(stream, stream->writefilters.head, is_start_seeking,
      offset, whence, PHP_STREAM_FILTER_WRITE) == FAILURE) {
    return FAILURE;
  }
  if (php_stream_filters_seek(stream, stream->readfilters.head, is_start_seeking,
      offset, whence, PHP_STREAM_FILTER_READ) == FAILURE) {
    return FAILURE;
  }

  return SUCCESS;
}



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;
    }
  }

  bool is_start_seeking = whence == SEEK_SET && offset == 0;

  if (stream->writefilters.head) {
    _php_stream_flush(stream, 0);
    if (!php_stream_are_filters_seekable(stream->writefilters.head, is_start_seeking,
        PHP_STREAM_FILTER_WRITE)) {
      return -1;
    }
  }
  if (stream->readfilters.head && !php_stream_are_filters_seekable(
      stream->readfilters.head, is_start_seeking, PHP_STREAM_FILTER_READ)) {
    return -1;
  }

  /* 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;
          stream->fatal_error = 0;
          return php_stream_filters_seek_all(stream, is_start_seeking, offset, whence) == SUCCESS ? 0 : -1;
        }
        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;
          stream->fatal_error = 0;
          return php_stream_filters_seek_all(stream, is_start_seeking, offset, whence) == SUCCESS ? 0 : -1;
        }
        break;
    }
  }


  if (stream->ops->seek && (stream->flags & PHP_STREAM_FLAG_NO_SEEK) == 0) {
    int ret;
    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;
        stream->fatal_error = 0;
      }

      /* invalidate the buffer contents */
      stream->readpos = stream->writepos = 0;

      return php_stream_filters_seek_all(stream, is_start_seeking, offset, whence) == SUCCESS ? ret : -1;
    }
    /* 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;
    stream->fatal_error = 0;
    return 0;
  }

  php_stream_warn(stream, SeekNotSupported,
      "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, bool persistent STREAMS_DC)
{
  ssize_t ret = 0;
  char *ptr;
  size_t len = 0, buflen;
  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 CHUNK_SIZE 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) + CHUNK_SIZE;
    if (maxlen > 0 && buflen > maxlen) {
      buflen = maxlen;
    }
  } else {
    buflen = CHUNK_SIZE;
  }

  result = zend_string_alloc(buflen, persistent);
  ptr = ZSTR_VAL(result);

  const int min_room = CHUNK_SIZE / 4;
  // 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 + CHUNK_SIZE > maxlen) {
        buflen = maxlen;
      } else {
        buflen += CHUNK_SIZE;
      }
      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_logged_errors)) {
    zend_hash_destroy(FG(wrapper_logged_errors));
    efree(FG(wrapper_logged_errors));
    FG(wrapper_logged_errors) = NULL;
  }

  php_stream_error_state_cleanup();
}

zend_result 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, size_t protocol_len)
{
  for (size_t i = 0; i < protocol_len; i++) {
    if (!isalnum((unsigned char)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)
{
  const 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((unsigned char)*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) {
      bool localhost = false;

      if (!strncasecmp(path, "file://localhost/", 17)) {
        localhost = true;
      }

#ifdef PHP_WIN32
      if (!localhost && path[n+3] != '\0' && path[n+3] != '/' && path[n+4] != ':')  {
#else
      if (!localhost && path[n+3] != '\0' && path[n+3] != '/') {
#endif
        if (options & REPORT_ERRORS) {
          php_stream_wrapper_warn(plain_files_wrapper, NULL, options,
              ProtocolUnsupported,
              "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) {
          (*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_stream_wrapper_warn(plain_files_wrapper, NULL, options,
          Disabled,
          "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_warn(wrapper, context, options & ~REPORT_ERRORS,
        NoOpener, "not implemented");
  }
  if (stream == NULL && (options & REPORT_ERRORS)) {
    php_stream_display_wrapper_errors(wrapper, context, PHP_STREAM_EC(OpenFailed),
        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;

  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)) {
    if (wrapper) {
      php_stream_wrapper_warn(wrapper, context, options,
          ProtocolUnsupported,
          "This function may only be used against URLs");
    } else {
      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;
  }

  /* wrapper name needs to be stored as wrapper can be removed in opener (user stream) */
  char *wrapper_name = pestrdup(PHP_STREAM_ERROR_WRAPPER_NAME(wrapper), persistent);
  if (wrapper) {
    if (!wrapper->wops->stream_opener) {
      php_stream_wrapper_log_warn(wrapper, context, options & ~REPORT_ERRORS,
          NoOpener,
          "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 && persistent && !stream->is_persistent) {
      php_stream_wrapper_log_warn(wrapper, context, options & ~REPORT_ERRORS,
          PersistentNotSupported,
          "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);
    }
    stream->orig_path = pestrdup(path, persistent);
#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->ctx == NULL && context != NULL && !persistent) {
      php_stream_context_set(stream, context);
    }
  }

  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);
        }
        pefree(wrapper_name, persistent);
        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);
        }
        pefree(wrapper_name, persistent);
        return newstream;
      default:
        php_stream_close(stream);
        stream = NULL;
        if (options & REPORT_ERRORS) {
          char *tmp = estrdup(path);
          php_strip_url_passwd(tmp);
          php_stream_wrapper_warn_param(wrapper, context, options,
              SeekNotSupported, tmp,
              "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_name_errors(wrapper_name, context, PHP_STREAM_EC(OpenFailed),
        path, "Failed to open stream");
    if (opened_path && *opened_path) {
      zend_string_release_ex(*opened_path, 0);
      *opened_path = NULL;
    }
  }
  php_stream_tidy_wrapper_name_error_log(wrapper_name);
  pefree(wrapper_name, persistent);
  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(const 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);
}

void php_stream_context_unset_option(php_stream_context *context,
  const char *wrappername, const char *optionname)
{
  zval *wrapperhash;

  wrapperhash = zend_hash_str_find(Z_ARRVAL(context->options), wrappername, strlen(wrappername));
  if (NULL == wrapperhash) {
    return;
  }
  SEPARATE_ARRAY(&context->options);
  SEPARATE_ARRAY(wrapperhash);
  zend_hash_str_del(Z_ARRVAL_P(wrapperhash), optionname, strlen(optionname));
}
/* }}} */

PHPAPI const struct php_uri_parser *php_stream_context_get_uri_parser(const char *wrappername, php_stream_context *context)
{
  if (context == NULL) {
    return php_uri_get_parser(NULL);
  }

  zval *uri_parser_name = php_stream_context_get_option(context, wrappername, "uri_parser_class");
  if (uri_parser_name == NULL || Z_TYPE_P(uri_parser_name) == IS_NULL) {
    return php_uri_get_parser(NULL);
  }

  if (Z_TYPE_P(uri_parser_name) != IS_STRING) {
    return NULL;
  }

  return php_uri_get_parser(Z_STR_P(uri_parser_name));
}

/* {{{ 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;
}
/* }}} */

Coverage Report

Created: 2026-06-02 06:36