1 /*
2 +----------------------------------------------------------------------+
3 | Copyright (c) The PHP Group |
4 +----------------------------------------------------------------------+
5 | This source file is subject to version 3.01 of the PHP license, |
6 | that is bundled with this package in the file LICENSE, and is |
7 | available through the world-wide-web at the following url: |
8 | https://www.php.net/license/3_01.txt |
9 | If you did not receive a copy of the PHP license and are unable to |
10 | obtain it through the world-wide-web, please send a note to |
11 | license@php.net so we can mail you a copy immediately. |
12 +----------------------------------------------------------------------+
13 | Authors: Niels Dossche <nielsdos@php.net> |
14 +----------------------------------------------------------------------+
15 */
16
17 #ifdef HAVE_CONFIG_H
18 #include <config.h>
19 #endif
20
21 #include "php.h"
22 #if defined(HAVE_LIBXML) && defined(HAVE_DOM)
23 #include "php_dom.h"
24 #include "html5_serializer.h"
25 #include "namespace_compat.h"
26 #include "serialize_common.h"
27 #include <lexbor/encoding/encoding.h>
28
29 /* This file implements the HTML 5 serialization algorithm.
30 * https://html.spec.whatwg.org/multipage/parsing.html#serialising-html-fragments (Date 2023-12-14)
31 */
32
33 #define TRY(x) do { if (UNEXPECTED((x) != SUCCESS)) { return FAILURE; } } while (0)
34
dom_html5_serialize_doctype(dom_html5_serialize_context * ctx,const xmlDtd * dtd)35 static zend_result dom_html5_serialize_doctype(dom_html5_serialize_context *ctx, const xmlDtd *dtd)
36 {
37 TRY(ctx->write_string_len(ctx->application_data, "<!DOCTYPE ", strlen("<!DOCTYPE ")));
38 TRY(ctx->write_string(ctx->application_data, (const char *) dtd->name));
39 return ctx->write_string_len(ctx->application_data, ">", strlen(">"));
40 }
41
dom_html5_serialize_comment(dom_html5_serialize_context * ctx,const xmlNode * node)42 static zend_result dom_html5_serialize_comment(dom_html5_serialize_context *ctx, const xmlNode *node)
43 {
44 TRY(ctx->write_string_len(ctx->application_data, "<!--", strlen("<!--")));
45 if (node->content) {
46 TRY(ctx->write_string(ctx->application_data, (const char*) node->content));
47 }
48 return ctx->write_string_len(ctx->application_data, "-->", strlen("-->"));
49 }
50
dom_html5_serialize_processing_instruction(dom_html5_serialize_context * ctx,const xmlNode * node)51 static zend_result dom_html5_serialize_processing_instruction(dom_html5_serialize_context *ctx, const xmlNode *node)
52 {
53 TRY(ctx->write_string_len(ctx->application_data, "<?", strlen("<?")));
54 TRY(ctx->write_string(ctx->application_data, (const char *) node->name));
55 TRY(ctx->write_string_len(ctx->application_data, " ", strlen(" ")));
56 if (node->content) {
57 TRY(ctx->write_string(ctx->application_data, (const char *) node->content));
58 }
59 return ctx->write_string_len(ctx->application_data, ">", strlen(">"));
60 }
61
dom_html5_serialize_entity_ref(dom_html5_serialize_context * ctx,const xmlNode * node)62 static zend_result dom_html5_serialize_entity_ref(dom_html5_serialize_context *ctx, const xmlNode *node)
63 {
64 TRY(ctx->write_string_len(ctx->application_data, "&", strlen("&")));
65 TRY(ctx->write_string(ctx->application_data, (const char *) node->name));
66 return ctx->write_string_len(ctx->application_data, ";", strlen(";"));
67 }
68
69 /* https://html.spec.whatwg.org/multipage/parsing.html#escapingString */
dom_html5_escape_string(dom_html5_serialize_context * ctx,const char * content,bool attribute_mode)70 static zend_result dom_html5_escape_string(dom_html5_serialize_context *ctx, const char *content, bool attribute_mode)
71 {
72 const char *last_output = content;
73
74 /* Note: uses UTF-8 internally, so <C2 A0> indicates a non-breaking space */
75 const char *mask = attribute_mode ? "&\xC2\"" : "&\xC2<>";
76
77 while (true) {
78 size_t chunk_length = strcspn(content, mask);
79
80 content += chunk_length;
81 if (*content == '\0') {
82 break;
83 }
84
85 switch (*content) {
86 /* Step 1 */
87 case '&': {
88 TRY(ctx->write_string_len(ctx->application_data, last_output, content - last_output));
89 TRY(ctx->write_string_len(ctx->application_data, "&", strlen("&")));
90 last_output = content + 1;
91 break;
92 }
93
94 /* Step 2 (non-breaking space) (note: uses UTF-8 internally) */
95 case '\xC2': {
96 if (content[1] == '\xA0') {
97 TRY(ctx->write_string_len(ctx->application_data, last_output, content - last_output));
98 TRY(ctx->write_string_len(ctx->application_data, " ", strlen(" ")));
99 content++; /* Consume A0 too */
100 last_output = content + 1;
101 }
102 break;
103 }
104
105 /* Step 3 */
106 case '"': {
107 TRY(ctx->write_string_len(ctx->application_data, last_output, content - last_output));
108 TRY(ctx->write_string_len(ctx->application_data, """, strlen(""")));
109 last_output = content + 1;
110 break;
111 }
112
113 /* Step 4 */
114 case '<': {
115 TRY(ctx->write_string_len(ctx->application_data, last_output, content - last_output));
116 TRY(ctx->write_string_len(ctx->application_data, "<", strlen("<")));
117 last_output = content + 1;
118 break;
119 }
120 case '>': {
121 TRY(ctx->write_string_len(ctx->application_data, last_output, content - last_output));
122 TRY(ctx->write_string_len(ctx->application_data, ">", strlen(">")));
123 last_output = content + 1;
124 break;
125 }
126 }
127
128 content++;
129 }
130
131 return ctx->write_string_len(ctx->application_data, last_output, content - last_output);
132 }
133
dom_html5_serialize_text_node(dom_html5_serialize_context * ctx,const xmlNode * node)134 static zend_result dom_html5_serialize_text_node(dom_html5_serialize_context *ctx, const xmlNode *node)
135 {
136 if (!node->content) {
137 return SUCCESS;
138 }
139
140 const xmlNode *parent = node->parent;
141 if (parent != NULL && parent->type == XML_ELEMENT_NODE && php_dom_ns_is_fast(parent, php_dom_ns_is_html_magic_token)) {
142 size_t name_length = strlen((const char *) parent->name);
143 /* Spec tells us to only emit noscript content as-is if scripting is enabled.
144 * However, the user agent (PHP) does not support (JS) scripting.
145 * Furthermore, if actually consumed by a browser then we should err on the safe side and not emit the content as-is. */
146 if (dom_local_name_compare_ex(parent, "style", strlen("style"), name_length)
147 || dom_local_name_compare_ex(parent, "script", strlen("script"), name_length)
148 || dom_local_name_compare_ex(parent, "xmp", strlen("xmp"), name_length)
149 || dom_local_name_compare_ex(parent, "iframe", strlen("iframe"), name_length)
150 || dom_local_name_compare_ex(parent, "noembed", strlen("noembed"), name_length)
151 || dom_local_name_compare_ex(parent, "noframes", strlen("noframes"), name_length)
152 || dom_local_name_compare_ex(parent, "plaintext", strlen("plaintext"), name_length)) {
153 return ctx->write_string(ctx->application_data, (const char *) node->content);
154 }
155 }
156
157 return dom_html5_escape_string(ctx, (const char *) node->content, false);
158 }
159
dom_html5_serialize_element_tag_name(dom_html5_serialize_context * ctx,const xmlNode * node)160 static zend_result dom_html5_serialize_element_tag_name(dom_html5_serialize_context *ctx, const xmlNode *node)
161 {
162 /* Note: it is not the serializer's responsibility to care about uppercase/lowercase (see createElement() note) */
163 if (node->ns != NULL && node->ns->prefix != NULL
164 && !(php_dom_ns_is_fast(node, php_dom_ns_is_html_magic_token) || php_dom_ns_is_fast(node, php_dom_ns_is_mathml_magic_token) || php_dom_ns_is_fast(node, php_dom_ns_is_svg_magic_token))) {
165 TRY(ctx->write_string(ctx->application_data, (const char *) node->ns->prefix));
166 TRY(ctx->write_string_len(ctx->application_data, ":", strlen(":")));
167 }
168 return ctx->write_string(ctx->application_data, (const char *) node->name);
169 }
170
dom_html5_serialize_element_start(dom_html5_serialize_context * ctx,const xmlNode * node)171 static zend_result dom_html5_serialize_element_start(dom_html5_serialize_context *ctx, const xmlNode *node)
172 {
173 TRY(ctx->write_string_len(ctx->application_data, "<", strlen("<")));
174 TRY(dom_html5_serialize_element_tag_name(ctx, node));
175
176 /* We don't support the "is" value during element creation, so no handling here. */
177
178 for (const xmlAttr *attr = node->properties; attr; attr = attr->next) {
179 TRY(ctx->write_string_len(ctx->application_data, " ", strlen(" ")));
180 if (attr->ns == NULL) {
181 TRY(ctx->write_string(ctx->application_data, (const char *) attr->name));
182 } else {
183 if (php_dom_ns_is_fast((const xmlNode *) attr, php_dom_ns_is_xml_magic_token)) {
184 TRY(ctx->write_string_len(ctx->application_data, "xml:", strlen("xml:")));
185 TRY(ctx->write_string(ctx->application_data, (const char *) attr->name));
186 } else if (php_dom_ns_is_fast((const xmlNode *) attr, php_dom_ns_is_xmlns_magic_token)) {
187 /* Compatibility for real attributes */
188 if (strcmp((const char *) attr->name, "xmlns") == 0) {
189 TRY(ctx->write_string_len(ctx->application_data, "xmlns", strlen("xmlns")));
190 } else {
191 TRY(ctx->write_string_len(ctx->application_data, "xmlns:", strlen("xmlns:")));
192 TRY(ctx->write_string(ctx->application_data, (const char *) attr->name));
193 }
194 } else if (php_dom_ns_is_fast((const xmlNode *) attr, php_dom_ns_is_xlink_magic_token)) {
195 TRY(ctx->write_string_len(ctx->application_data, "xlink:", strlen("xlink:")));
196 TRY(ctx->write_string(ctx->application_data, (const char *) attr->name));
197 } else if (attr->ns->prefix == NULL) {
198 TRY(ctx->write_string(ctx->application_data, (const char *) attr->name));
199 } else {
200 TRY(ctx->write_string(ctx->application_data, (const char *) attr->ns->prefix));
201 TRY(ctx->write_string_len(ctx->application_data, ":", strlen(":")));
202 TRY(ctx->write_string(ctx->application_data, (const char *) attr->name));
203 }
204 }
205
206 TRY(ctx->write_string_len(ctx->application_data, "=\"", strlen("=\"")));
207
208 for (xmlNodePtr child = attr->children; child != NULL; child = child->next) {
209 if (child->type == XML_TEXT_NODE) {
210 if (child->content != NULL) {
211 TRY(dom_html5_escape_string(ctx, (const char *) child->content, true));
212 }
213 } else if (child->type == XML_ENTITY_REF_NODE) {
214 TRY(ctx->write_string_len(ctx->application_data, "&", strlen("&")));
215 TRY(dom_html5_escape_string(ctx, (const char *) child->name, true));
216 TRY(ctx->write_string_len(ctx->application_data, ";", strlen(";")));
217 }
218 }
219
220 TRY(ctx->write_string_len(ctx->application_data, "\"", strlen("\"")));
221 }
222
223 return ctx->write_string_len(ctx->application_data, ">", strlen(">"));
224
225 /* Note: "continue on to the next child if the element is void" is handled in the iteration and dom_html5_serialize_element_end() */
226 }
227
228 /* https://html.spec.whatwg.org/multipage/syntax.html#void-elements
229 * https://html.spec.whatwg.org/multipage/parsing.html#serializes-as-void */
dom_html5_serializes_as_void(const xmlNode * node)230 static bool dom_html5_serializes_as_void(const xmlNode *node)
231 {
232 if (php_dom_ns_is_fast(node, php_dom_ns_is_html_magic_token)) {
233 size_t name_length = strlen((const char *) node->name);
234 if (/* These are the void elements from https://html.spec.whatwg.org/multipage/syntax.html#void-elements */
235 dom_local_name_compare_ex(node, "area", strlen("area"), name_length)
236 || dom_local_name_compare_ex(node, "base", strlen("base"), name_length)
237 || dom_local_name_compare_ex(node, "br", strlen("br"), name_length)
238 || dom_local_name_compare_ex(node, "col", strlen("col"), name_length)
239 || dom_local_name_compare_ex(node, "embed", strlen("embed"), name_length)
240 || dom_local_name_compare_ex(node, "hr", strlen("hr"), name_length)
241 || dom_local_name_compare_ex(node, "img", strlen("img"), name_length)
242 || dom_local_name_compare_ex(node, "input", strlen("input"), name_length)
243 || dom_local_name_compare_ex(node, "link", strlen("link"), name_length)
244 || dom_local_name_compare_ex(node, "meta", strlen("meta"), name_length)
245 || dom_local_name_compare_ex(node, "source", strlen("source"), name_length)
246 || dom_local_name_compare_ex(node, "track", strlen("track"), name_length)
247 || dom_local_name_compare_ex(node, "wbr", strlen("wbr"), name_length)
248 /* These are the additional names from https://html.spec.whatwg.org/multipage/parsing.html#serializes-as-void */
249 || dom_local_name_compare_ex(node, "basefont", strlen("basefont"), name_length)
250 || dom_local_name_compare_ex(node, "bgsound", strlen("bgsound"), name_length)
251 || dom_local_name_compare_ex(node, "frame", strlen("frame"), name_length)
252 || dom_local_name_compare_ex(node, "keygen", strlen("keygen"), name_length)
253 || dom_local_name_compare_ex(node, "param", strlen("param"), name_length)) {
254 return true;
255 }
256 }
257 return false;
258 }
259
dom_html5_serialize_element_end(dom_html5_serialize_context * ctx,const xmlNode * node)260 static zend_result dom_html5_serialize_element_end(dom_html5_serialize_context *ctx, const xmlNode *node)
261 {
262 if (!dom_html5_serializes_as_void(node)) {
263 TRY(ctx->write_string_len(ctx->application_data, "</", strlen("</")));
264 TRY(dom_html5_serialize_element_tag_name(ctx, node));
265 return ctx->write_string_len(ctx->application_data, ">", strlen(">"));
266 }
267 return SUCCESS;
268 }
269
270 /* https://html.spec.whatwg.org/multipage/parsing.html#html-fragment-serialisation-algorithm */
dom_html5_serialize_node(dom_html5_serialize_context * ctx,const xmlNode * node,const xmlNode * bound)271 static zend_result dom_html5_serialize_node(dom_html5_serialize_context *ctx, const xmlNode *node, const xmlNode *bound)
272 {
273 while (node != NULL) {
274 switch (node->type) {
275 case XML_DTD_NODE: {
276 TRY(dom_html5_serialize_doctype(ctx, (const xmlDtd *) node));
277 break;
278 }
279
280 case XML_CDATA_SECTION_NODE:
281 case XML_TEXT_NODE: {
282 TRY(dom_html5_serialize_text_node(ctx, node));
283 break;
284 }
285
286 case XML_PI_NODE: {
287 TRY(dom_html5_serialize_processing_instruction(ctx, node));
288 break;
289 }
290
291 case XML_COMMENT_NODE: {
292 TRY(dom_html5_serialize_comment(ctx, node));
293 break;
294 }
295
296 case XML_ELEMENT_NODE: {
297 TRY(dom_html5_serialize_element_start(ctx, node));
298 const xmlNode *children = node->children;
299 if (php_dom_ns_is_fast(node, php_dom_ns_is_html_magic_token) && xmlStrEqual(node->name, BAD_CAST "template")) {
300 children = php_dom_retrieve_templated_content(ctx->private_data, node);
301 }
302 if (children) {
303 if (!dom_html5_serializes_as_void(node)) {
304 node = children;
305 continue;
306 }
307 } else {
308 /* Not descended, so wouldn't put the closing tag as it's normally only done when going back upwards. */
309 TRY(dom_html5_serialize_element_end(ctx, node));
310 }
311 break;
312 }
313
314 case XML_DOCUMENT_FRAG_NODE: {
315 if (node->children) {
316 node = node->children;
317 continue;
318 }
319 break;
320 }
321
322 /* Only exists for compatibility with XML and old DOM. */
323 case XML_ENTITY_REF_NODE: {
324 TRY(dom_html5_serialize_entity_ref(ctx, node));
325 break;
326 }
327
328 default:
329 break;
330 }
331
332 if (node->next) {
333 node = node->next;
334 } else {
335 /* Go upwards, until we find a parent node with a next sibling, or until we hit the bound. */
336 do {
337 node = node->parent;
338 if (node == bound) {
339 return SUCCESS;
340 }
341 if (node->type == XML_ELEMENT_NODE) {
342 TRY(dom_html5_serialize_element_end(ctx, node));
343 }
344 } while (node->next == NULL);
345 node = node->next;
346 }
347 }
348
349 return SUCCESS;
350 }
351
352 /* Note: this serializes the _children_, excluding the node itself! */
dom_html5_serialize(dom_html5_serialize_context * ctx,const xmlNode * node)353 zend_result dom_html5_serialize(dom_html5_serialize_context *ctx, const xmlNode *node)
354 {
355 /* Step 1. Note that this algorithm serializes children. Only elements, documents, and fragments can have children. */
356 if (node->type != XML_ELEMENT_NODE
357 && node->type != XML_DOCUMENT_FRAG_NODE
358 && node->type != XML_DOCUMENT_NODE
359 && node->type != XML_HTML_DOCUMENT_NODE) {
360 return SUCCESS;
361 }
362 if (node->type == XML_ELEMENT_NODE && dom_html5_serializes_as_void(node)) {
363 return SUCCESS;
364 }
365
366 /* Step 2 not needed because we're not using a string to store the serialized data */
367
368 /* Step 3. If the node is a template element, then let the node instead be the template element's template contents (a DocumentFragment node). */
369 xmlNodePtr children = php_dom_retrieve_templated_content(ctx->private_data, node);
370 if (!children) {
371 children = node->children;
372 }
373
374 /* Step 4 */
375 return dom_html5_serialize_node(ctx, children, node);
376 }
377
378 /* Variant on the above that is equivalent to the "outer HTML". */
dom_html5_serialize_outer(dom_html5_serialize_context * ctx,const xmlNode * node)379 zend_result dom_html5_serialize_outer(dom_html5_serialize_context *ctx, const xmlNode *node)
380 {
381 if (node->type == XML_DOCUMENT_NODE || node->type == XML_HTML_DOCUMENT_NODE || node->type == XML_DOCUMENT_FRAG_NODE) {
382 node = node->children;
383 if (!node) {
384 return SUCCESS;
385 }
386 return dom_html5_serialize_node(ctx, node, node->parent);
387 } else {
388 xmlNodePtr old_next = node->next;
389 ((xmlNodePtr) node)->next = NULL;
390 zend_result result = dom_html5_serialize_node(ctx, node, node->parent);
391 ((xmlNodePtr) node)->next = old_next;
392 return result;
393 }
394 }
395
396 #endif /* HAVE_LIBXML && HAVE_DOM */
397
