1 /*
2  * xlink.c : implementation of the hyperlinks detection module
3  *           This version supports both XML XLinks and HTML simple links
4  *
5  * See Copyright for the status of this software.
6  *
7  * daniel@veillard.com
8  */
9 
10 
11 #define IN_LIBXML
12 #include "libxml.h"
13 
14 #ifdef LIBXML_XPTR_ENABLED
15 #include <string.h> /* for memset() only */
16 #ifdef HAVE_CTYPE_H
17 #include <ctype.h>
18 #endif
19 #ifdef HAVE_STDLIB_H
20 #include <stdlib.h>
21 #endif
22 #ifdef HAVE_SYS_STAT_H
23 #include <sys/stat.h>
24 #endif
25 #ifdef HAVE_FCNTL_H
26 #include <fcntl.h>
27 #endif
28 #ifdef HAVE_UNISTD_H
29 #include <unistd.h>
30 #endif
31 #ifdef HAVE_ZLIB_H
32 #include <zlib.h>
33 #endif
34 
35 #include <libxml/xmlmemory.h>
36 #include <libxml/tree.h>
37 #include <libxml/parser.h>
38 #include <libxml/valid.h>
39 #include <libxml/xlink.h>
40 #include <libxml/globals.h>
41 
42 #define XLINK_NAMESPACE (BAD_CAST "http://www.w3.org/1999/xlink/namespace/")
43 #define XHTML_NAMESPACE (BAD_CAST "http://www.w3.org/1999/xhtml/")
44 
45 /****************************************************************
46  *								*
47  *           Default setting and related functions		*
48  *								*
49  ****************************************************************/
50 
51 static xlinkHandlerPtr xlinkDefaultHandler = NULL;
52 static xlinkNodeDetectFunc	xlinkDefaultDetect = NULL;
53 
54 /**
55  * xlinkGetDefaultHandler:
56  *
57  * Get the default xlink handler.
58  *
59  * Returns the current xlinkHandlerPtr value.
60  */
61 xlinkHandlerPtr
xlinkGetDefaultHandler(void)62 xlinkGetDefaultHandler(void) {
63     return(xlinkDefaultHandler);
64 }
65 
66 
67 /**
68  * xlinkSetDefaultHandler:
69  * @handler:  the new value for the xlink handler block
70  *
71  * Set the default xlink handlers
72  */
73 void
xlinkSetDefaultHandler(xlinkHandlerPtr handler)74 xlinkSetDefaultHandler(xlinkHandlerPtr handler) {
75     xlinkDefaultHandler = handler;
76 }
77 
78 /**
79  * xlinkGetDefaultDetect:
80  *
81  * Get the default xlink detection routine
82  *
83  * Returns the current function or NULL;
84  */
85 xlinkNodeDetectFunc
xlinkGetDefaultDetect(void)86 xlinkGetDefaultDetect	(void) {
87     return(xlinkDefaultDetect);
88 }
89 
90 /**
91  * xlinkSetDefaultDetect:
92  * @func: pointer to the new detection routine.
93  *
94  * Set the default xlink detection routine
95  */
96 void
xlinkSetDefaultDetect(xlinkNodeDetectFunc func)97 xlinkSetDefaultDetect	(xlinkNodeDetectFunc func) {
98     xlinkDefaultDetect = func;
99 }
100 
101 /****************************************************************
102  *								*
103  *                  The detection routines			*
104  *								*
105  ****************************************************************/
106 
107 
108 /**
109  * xlinkIsLink:
110  * @doc:  the document containing the node
111  * @node:  the node pointer itself
112  *
113  * Check whether the given node carries the attributes needed
114  * to be a link element (or is one of the linking elements issued
115  * from the (X)HTML DtDs).
116  * This routine don't try to do full checking of the link validity
117  * but tries to detect and return the appropriate link type.
118  *
119  * Returns the xlinkType of the node (XLINK_TYPE_NONE if there is no
120  *         link detected.
121  */
122 xlinkType
xlinkIsLink(xmlDocPtr doc,xmlNodePtr node)123 xlinkIsLink	(xmlDocPtr doc, xmlNodePtr node) {
124     xmlChar *type = NULL, *role = NULL;
125     xlinkType ret = XLINK_TYPE_NONE;
126 
127     if (node == NULL) return(XLINK_TYPE_NONE);
128     if (doc == NULL) doc = node->doc;
129     if ((doc != NULL) && (doc->type == XML_HTML_DOCUMENT_NODE)) {
130         /*
131 	 * This is an HTML document.
132 	 */
133     } else if ((node->ns != NULL) &&
134                (xmlStrEqual(node->ns->href, XHTML_NAMESPACE))) {
135 	/*
136 	 * !!!! We really need an IS_XHTML_ELEMENT function from HTMLtree.h @@@
137 	 */
138         /*
139 	 * This is an XHTML element within an XML document
140 	 * Check whether it's one of the element able to carry links
141 	 * and in that case if it holds the attributes.
142 	 */
143     }
144 
145     /*
146      * We don't prevent a-priori having XML Linking constructs on
147      * XHTML elements
148      */
149     type = xmlGetNsProp(node, BAD_CAST"type", XLINK_NAMESPACE);
150     if (type != NULL) {
151 	if (xmlStrEqual(type, BAD_CAST "simple")) {
152             ret = XLINK_TYPE_SIMPLE;
153 	} else if (xmlStrEqual(type, BAD_CAST "extended")) {
154 	    role = xmlGetNsProp(node, BAD_CAST "role", XLINK_NAMESPACE);
155 	    if (role != NULL) {
156 		xmlNsPtr xlink;
157 		xlink = xmlSearchNs(doc, node, XLINK_NAMESPACE);
158 		if (xlink == NULL) {
159 		    /* Humm, fallback method */
160 		    if (xmlStrEqual(role, BAD_CAST"xlink:external-linkset"))
161 			ret = XLINK_TYPE_EXTENDED_SET;
162 		} else {
163 		    xmlChar buf[200];
164 		    snprintf((char *) buf, sizeof(buf), "%s:external-linkset",
165 			     (char *) xlink->prefix);
166                     buf[sizeof(buf) - 1] = 0;
167 		    if (xmlStrEqual(role, buf))
168 			ret = XLINK_TYPE_EXTENDED_SET;
169 
170 		}
171 
172 	    }
173 	    ret = XLINK_TYPE_EXTENDED;
174 	}
175     }
176 
177     if (type != NULL) xmlFree(type);
178     if (role != NULL) xmlFree(role);
179     return(ret);
180 }
181 #endif /* LIBXML_XPTR_ENABLED */
182 #define bottom_xlink
183 #include "elfgcchack.h"
184