php_libxml.h

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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: Shane Caraveo <shane@php.net>                               |
   |          Wez Furlong <wez@thebrainroom.com>                          |
   +----------------------------------------------------------------------+
*/
 
#ifndef PHP_LIBXML_H
#define PHP_LIBXML_H
 
#ifdef HAVE_LIBXML
extern zend_module_entry libxml_module_entry;
#define libxml_module_ptr &libxml_module_entry
 
#include "php_version.h"
#define PHP_LIBXML_VERSION PHP_VERSION
 
#ifdef PHP_WIN32
#   define PHP_LIBXML_API __declspec(dllexport)
#elif defined(__GNUC__) && __GNUC__ >= 4
#   define PHP_LIBXML_API __attribute__ ((visibility("default")))
#else
#   define PHP_LIBXML_API
#endif
 
#include "zend_smart_str.h"
#include <libxml/tree.h>
#include <libxml/parser.h>
 
#define LIBXML_SAVE_NOEMPTYTAG 1<<2
 
#define LIBXML_NS_TAG_HOOK 1
 
ZEND_BEGIN_MODULE_GLOBALS(libxml)
    zval stream_context;
    smart_str error_buffer;
    zend_llist *error_list;
    zend_fcall_info_cache entity_loader_callback;
    bool entity_loader_disabled;
ZEND_END_MODULE_GLOBALS(libxml)
 
typedef struct _libxml_doc_props {
    HashTable *classmap;
    bool formatoutput;
    bool validateonparse;
    bool resolveexternals;
    bool preservewhitespace;
    bool substituteentities;
    bool stricterror;
    bool recover;
} libxml_doc_props;
 
/* Modification tracking: when the object changes, we increment its counter.
 * When this counter no longer matches the counter at the time of caching,
 * we know that the object has changed and we have to update the cache. */
typedef struct {
    size_t modification_nr;
} php_libxml_cache_tag;
 
typedef struct php_libxml_private_data_header {
    void (*dtor)(struct php_libxml_private_data_header *);
    void (*ns_hook)(struct php_libxml_private_data_header *, xmlNodePtr);
    /* extra fields */
} php_libxml_private_data_header;

typedef struct php_libxml_document_handlers {
    zend_string *(*dump_node_to_str)(xmlDocPtr doc, xmlNodePtr node, bool format, const char *encoding);
    zend_string *(*dump_doc_to_str)(xmlDocPtr doc, int options, const char *encoding);
    zend_long (*dump_node_to_file)(const char *filename, xmlDocPtr doc, xmlNodePtr node, bool format, const char *encoding);
    zend_long (*dump_doc_to_file)(const char *filename, xmlDocPtr doc, bool format, const char *encoding);
} php_libxml_document_handlers;

typedef enum _php_libxml_class_type {
    PHP_LIBXML_CLASS_UNSET = 0,
    PHP_LIBXML_CLASS_LEGACY = 1,
    PHP_LIBXML_CLASS_MODERN = 2,
} php_libxml_class_type;
 
typedef enum php_libxml_quirks_mode {
    PHP_LIBXML_NO_QUIRKS = 0,
    PHP_LIBXML_QUIRKS,
    PHP_LIBXML_LIMITED_QUIRKS,
} php_libxml_quirks_mode;
 
typedef struct _php_libxml_ref_obj {
    void *ptr;
    libxml_doc_props *doc_props;
    php_libxml_cache_tag cache_tag;
    php_libxml_private_data_header *private_data;
    const php_libxml_document_handlers *handlers;
    unsigned int refcount;
    php_libxml_class_type class_type : 8;
    php_libxml_quirks_mode quirks_mode : 8;
} php_libxml_ref_obj;
 
typedef struct _php_libxml_node_ptr {
    xmlNodePtr node;
    unsigned int refcount;
    void *_private;
} php_libxml_node_ptr;
 
typedef struct _php_libxml_node_object {
    php_libxml_node_ptr *node;
    php_libxml_ref_obj *document;
    zend_object  std;
} php_libxml_node_object;
 
 
static inline php_libxml_node_object *php_libxml_node_fetch_object(zend_object *obj) {
    return (php_libxml_node_object *)((char*)(obj) - obj->handlers->offset);
}
 
static zend_always_inline void php_libxml_invalidate_cache_tag(php_libxml_cache_tag *cache_tag)
{
#if SIZEOF_SIZE_T == 8
    /* If one operation happens every nanosecond, then it would still require 584 years to overflow
     * the counter. So we'll just assume this never happens. */
    cache_tag->modification_nr++;
#else
    size_t new_modification_nr = cache_tag->modification_nr + 1;
    if (EXPECTED(new_modification_nr > 0)) { /* unsigned overflow; checking after addition results in one less instruction */
        cache_tag->modification_nr = new_modification_nr;
    }
#endif
}
 
static zend_always_inline bool php_libxml_is_cache_tag_stale(const php_libxml_cache_tag *object_tag, const php_libxml_cache_tag *cache_tag)
{
    ZEND_ASSERT(object_tag != NULL);
    ZEND_ASSERT(cache_tag != NULL);
    /* See overflow comment in php_libxml_invalidate_node_list_cache(). */
#if SIZEOF_SIZE_T == 8
    return cache_tag->modification_nr != object_tag->modification_nr;
#else
    return cache_tag->modification_nr != object_tag->modification_nr || UNEXPECTED(object_tag->modification_nr == SIZE_MAX);
#endif
}
 
static zend_always_inline void php_libxml_invalidate_node_list_cache(php_libxml_ref_obj *doc_ptr)
{
    if (doc_ptr) {
        php_libxml_invalidate_cache_tag(&doc_ptr->cache_tag);
    }
}
 
static zend_always_inline void php_libxml_invalidate_node_list_cache_from_doc(xmlDocPtr docp)
{
    if (docp && docp->_private) { /* docp is NULL for detached nodes */
        php_libxml_node_ptr *node_private = (php_libxml_node_ptr *) docp->_private;
        php_libxml_node_object *object_private = (php_libxml_node_object *) node_private->_private;
        if (object_private) {
            php_libxml_invalidate_node_list_cache(object_private->document);
        }
    }
}
 
#define Z_LIBXML_NODE_P(zv) php_libxml_node_fetch_object(Z_OBJ_P((zv)))
 
typedef void * (*php_libxml_export_node) (zval *object);
 
typedef enum {
    PHP_LIBXML_ERROR = 0,
    PHP_LIBXML_CTX_ERROR = 1,
    PHP_LIBXML_CTX_WARNING = 2,
} php_libxml_error_level;
 
PHP_LIBXML_API int php_libxml_increment_node_ptr(php_libxml_node_object *object, xmlNodePtr node, void *private_data);
PHP_LIBXML_API int php_libxml_decrement_node_ptr(php_libxml_node_object *object);
PHP_LIBXML_API int php_libxml_decrement_node_ptr_ref(php_libxml_node_ptr *ptr);
PHP_LIBXML_API int php_libxml_increment_doc_ref(php_libxml_node_object *object, xmlDocPtr docp);
PHP_LIBXML_API int php_libxml_decrement_doc_ref_directly(php_libxml_ref_obj *document);
PHP_LIBXML_API int php_libxml_decrement_doc_ref(php_libxml_node_object *object);
PHP_LIBXML_API xmlNodePtr php_libxml_import_node(zval *object);
PHP_LIBXML_API zval *php_libxml_register_export(zend_class_entry *ce, php_libxml_export_node export_function);
/* When an explicit freeing of node and children is required */
PHP_LIBXML_API void php_libxml_node_free_list(xmlNodePtr node);
PHP_LIBXML_API void php_libxml_node_free_resource(xmlNodePtr node);
/* When object dtor is called as node may still be referenced */
PHP_LIBXML_API void php_libxml_node_decrement_resource(php_libxml_node_object *object);
PHP_LIBXML_API void php_libxml_error_handler(void *ctx, const char *msg, ...);
PHP_LIBXML_API void php_libxml_ctx_warning(void *ctx, const char *msg, ...);
PHP_LIBXML_API void php_libxml_pretend_ctx_error_ex(const char *file, int line, int column, const char *msg,...);
PHP_LIBXML_API void php_libxml_ctx_error(void *ctx, const char *msg, ...);
PHP_LIBXML_API void php_libxml_error_handler_va(php_libxml_error_level error_type, void *ctx, const char *msg, va_list args);
PHP_LIBXML_API int php_libxml_xmlCheckUTF8(const unsigned char *s);
PHP_LIBXML_API void php_libxml_switch_context(zval *context, zval *oldcontext);
PHP_LIBXML_API void php_libxml_issue_error(int level, const char *msg);
PHP_LIBXML_API bool php_libxml_disable_entity_loader(bool disable);
PHP_LIBXML_API void php_libxml_set_old_ns(xmlDocPtr doc, xmlNsPtr ns);
PHP_LIBXML_API php_stream_context *php_libxml_get_stream_context(void);
PHP_LIBXML_API bool php_libxml_uses_internal_errors(void);
 
PHP_LIBXML_API xmlChar *php_libxml_attr_value(const xmlAttr *attr, bool *free);
 
PHP_LIBXML_API zend_string *php_libxml_sniff_charset_from_string(const char *start, const char *end);
PHP_LIBXML_API zend_string *php_libxml_sniff_charset_from_stream(const php_stream *s);
 
/* Init/shutdown functions*/
PHP_LIBXML_API void php_libxml_initialize(void);
PHP_LIBXML_API void php_libxml_shutdown(void);
 
#define LIBXML(v) ZEND_MODULE_GLOBALS_ACCESSOR(libxml, v)
 
#if defined(ZTS) && defined(COMPILE_DL_LIBXML)
ZEND_TSRMLS_CACHE_EXTERN()
#endif
 
/* Other extension may override the global state options, these global options
 * are copied initially to ctxt->options. Set the options to a known good value.
 * See libxml2 globals.c and parserInternals.c.
 * The unique_name argument allows multiple sanitizes and restores within the
 * same function, even nested is necessary. */
# define PHP_LIBXML_SANITIZE_GLOBALS(unique_name) \
    ZEND_DIAGNOSTIC_IGNORED_START("-Wdeprecated-declarations") \
    int xml_old_loadsubset_##unique_name = xmlLoadExtDtdDefaultValue; \
    xmlLoadExtDtdDefaultValue = 0; \
    int xml_old_validate_##unique_name = xmlDoValidityCheckingDefaultValue; \
    xmlDoValidityCheckingDefaultValue = 0; \
    int xml_old_pedantic_##unique_name = xmlPedanticParserDefault(0); \
    int xml_old_substitute_##unique_name = xmlSubstituteEntitiesDefault(0); \
    int xml_old_linenrs_##unique_name = xmlLineNumbersDefault(0); \
    int xml_old_blanks_##unique_name = xmlKeepBlanksDefault(1); \
    ZEND_DIAGNOSTIC_IGNORED_END
 
# define PHP_LIBXML_RESTORE_GLOBALS(unique_name) \
    ZEND_DIAGNOSTIC_IGNORED_START("-Wdeprecated-declarations") \
    xmlLoadExtDtdDefaultValue = xml_old_loadsubset_##unique_name; \
    xmlDoValidityCheckingDefaultValue = xml_old_validate_##unique_name; \
    (void) xmlPedanticParserDefault(xml_old_pedantic_##unique_name); \
    (void) xmlSubstituteEntitiesDefault(xml_old_substitute_##unique_name); \
    (void) xmlLineNumbersDefault(xml_old_linenrs_##unique_name); \
    (void) xmlKeepBlanksDefault(xml_old_blanks_##unique_name); \
    ZEND_DIAGNOSTIC_IGNORED_END
 
/* Alternative for above, working directly on the context and not setting globals.
 * Generally faster because no locking is involved, and this has the advantage that it sets the options to a known good value. */
static zend_always_inline void php_libxml_sanitize_parse_ctxt_options(xmlParserCtxtPtr ctxt)
{
    ZEND_DIAGNOSTIC_IGNORED_START("-Wdeprecated-declarations") \
    ctxt->loadsubset = 0;
    ctxt->validate = 0;
    ctxt->pedantic = 0;
    ctxt->replaceEntities = 0;
    ctxt->linenumbers = 0;
    ctxt->keepBlanks = 1;
    ctxt->options = 0;
    ZEND_DIAGNOSTIC_IGNORED_END
}
#endif
 
#define phpext_libxml_ptr libxml_module_ptr
 
#endif /* PHP_LIBXML_H */