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30 
31 #include "XmlDocSource.h"
32 #include "AlwaysAssert.hpp"
33 #include <libxml/tree.h>
34 #include <libxml/xmlschemas.h>
35 #include <libxml/parser.h>
36 #include <libxml/xinclude.h>
37 #include <libxml/uri.h>
38 #include <memory>
39 #include <stdexcept>
40 
41 using std::string;
42 using xml_unique_ptr = std::unique_ptr<xmlChar, decltype(xmlFree)>;
43 
CXmlDocSource(_xmlDoc * pDoc,bool bValidateWithSchema,_xmlNode * pRootNode)44 CXmlDocSource::CXmlDocSource(_xmlDoc *pDoc, bool bValidateWithSchema, _xmlNode *pRootNode)
45     : _pDoc(pDoc), _pRootNode(pRootNode), _strRootElementType(""), _strRootElementName(""),
46       _strNameAttributeName(""), _bValidateWithSchema(bValidateWithSchema)
47 {
48 }
49 
CXmlDocSource(_xmlDoc * pDoc,bool bValidateWithSchema,const string & strRootElementType,const string & strRootElementName,const string & strNameAttributeName)50 CXmlDocSource::CXmlDocSource(_xmlDoc *pDoc, bool bValidateWithSchema,
51                              const string &strRootElementType, const string &strRootElementName,
52                              const string &strNameAttributeName)
53     : _pDoc(pDoc), _pRootNode(xmlDocGetRootElement(pDoc)), _strRootElementType(strRootElementType),
54       _strRootElementName(strRootElementName), _strNameAttributeName(strNameAttributeName),
55       _bValidateWithSchema(bValidateWithSchema)
56 {
57 }
58 
~CXmlDocSource()59 CXmlDocSource::~CXmlDocSource()
60 {
61     if (_pDoc) {
62         // Free XML doc
63         xmlFreeDoc(_pDoc);
64         _pDoc = NULL;
65     }
66 }
67 
getRootElement(CXmlElement & xmlRootElement) const68 void CXmlDocSource::getRootElement(CXmlElement &xmlRootElement) const
69 {
70     xmlRootElement.setXmlElement(_pRootNode);
71 }
72 
getRootElementName() const73 string CXmlDocSource::getRootElementName() const
74 {
75     return (const char *)_pRootNode->name;
76 }
77 
getRootElementAttributeString(const string & strAttributeName) const78 string CXmlDocSource::getRootElementAttributeString(const string &strAttributeName) const
79 {
80     CXmlElement topMostElement(_pRootNode);
81 
82     string attribute;
83     topMostElement.getAttribute(strAttributeName, attribute);
84     return attribute;
85 }
86 
setSchemaBaseUri(const string & uri)87 void CXmlDocSource::setSchemaBaseUri(const string &uri)
88 {
89     _schemaBaseUri = uri;
90 }
91 
getSchemaBaseUri()92 string CXmlDocSource::getSchemaBaseUri()
93 {
94     return _schemaBaseUri;
95 }
96 
getSchemaUri() const97 string CXmlDocSource::getSchemaUri() const
98 {
99     // Adding a trailing '/' is a bit dirty but works fine on both Linux and
100     // Windows in order to make sure that libxml2's URI handling methods
101     // interpret the base URI as a folder.
102     return mkUri(_schemaBaseUri + "/", getRootElementName() + ".xsd");
103 }
104 
getDoc() const105 _xmlDoc *CXmlDocSource::getDoc() const
106 {
107     return _pDoc;
108 }
109 
isParsable() const110 bool CXmlDocSource::isParsable() const
111 {
112     // Check that the doc has been created
113     return _pDoc != NULL;
114 }
115 
populate(CXmlSerializingContext & serializingContext)116 bool CXmlDocSource::populate(CXmlSerializingContext &serializingContext)
117 {
118     // Check that the doc has been created
119     if (!_pDoc) {
120 
121         serializingContext.setError("Could not parse document ");
122 
123         return false;
124     }
125 
126     // Validate if necessary
127     if (_bValidateWithSchema) {
128         if (!isInstanceDocumentValid()) {
129 
130             serializingContext.setError("Document is not valid");
131 
132             return false;
133         }
134     }
135 
136     // Check Root element type
137     if (getRootElementName() != _strRootElementType) {
138 
139         serializingContext.setError("Error: Wrong XML structure document ");
140         serializingContext.appendLineToError("Root Element " + getRootElementName() +
141                                              " mismatches expected type " + _strRootElementType);
142 
143         return false;
144     }
145 
146     if (!_strNameAttributeName.empty()) {
147 
148         string strRootElementNameCheck = getRootElementAttributeString(_strNameAttributeName);
149 
150         // Check Root element name attribute (if any)
151         if (!_strRootElementName.empty() && strRootElementNameCheck != _strRootElementName) {
152 
153             serializingContext.setError("Error: Wrong XML structure document ");
154             serializingContext.appendLineToError(
155                 _strRootElementType + " element " + _strRootElementName + " mismatches expected " +
156                 _strRootElementType + " type " + strRootElementNameCheck);
157 
158             return false;
159         }
160     }
161 
162     return true;
163 }
164 
isInstanceDocumentValid()165 bool CXmlDocSource::isInstanceDocumentValid()
166 {
167 #ifdef LIBXML_SCHEMAS_ENABLED
168     string schemaUri = getSchemaUri();
169 
170     xmlDocPtr pSchemaDoc = xmlReadFile(schemaUri.c_str(), NULL, XML_PARSE_NONET);
171 
172     if (!pSchemaDoc) {
173         // Unable to load Schema
174         return false;
175     }
176 
177     xmlSchemaParserCtxtPtr pParserCtxt = xmlSchemaNewDocParserCtxt(pSchemaDoc);
178 
179     if (!pParserCtxt) {
180 
181         // Unable to create schema context
182         xmlFreeDoc(pSchemaDoc);
183         return false;
184     }
185 
186     // Get Schema
187     xmlSchemaPtr pSchema = xmlSchemaParse(pParserCtxt);
188 
189     if (!pSchema) {
190 
191         // Invalid Schema
192         xmlSchemaFreeParserCtxt(pParserCtxt);
193         xmlFreeDoc(pSchemaDoc);
194         return false;
195     }
196     xmlSchemaValidCtxtPtr pValidationCtxt = xmlSchemaNewValidCtxt(pSchema);
197 
198     if (!pValidationCtxt) {
199 
200         // Unable to create validation context
201         xmlSchemaFree(pSchema);
202         xmlSchemaFreeParserCtxt(pParserCtxt);
203         xmlFreeDoc(pSchemaDoc);
204         return false;
205     }
206 
207     bool isDocValid = xmlSchemaValidateDoc(pValidationCtxt, _pDoc) == 0;
208 
209     xmlSchemaFreeValidCtxt(pValidationCtxt);
210     xmlSchemaFree(pSchema);
211     xmlSchemaFreeParserCtxt(pParserCtxt);
212     xmlFreeDoc(pSchemaDoc);
213 
214     return isDocValid;
215 #else
216     return true;
217 #endif
218 }
219 
mkUri(const std::string & base,const std::string & relative)220 std::string CXmlDocSource::mkUri(const std::string &base, const std::string &relative)
221 {
222     xml_unique_ptr baseUri(xmlPathToURI((const xmlChar *)base.c_str()), xmlFree);
223     xml_unique_ptr relativeUri(xmlPathToURI((const xmlChar *)relative.c_str()), xmlFree);
224     /* return null pointer if baseUri or relativeUri are null pointer  */
225     xml_unique_ptr xmlUri(xmlBuildURI(relativeUri.get(), baseUri.get()), xmlFree);
226 
227     ALWAYS_ASSERT(xmlUri != nullptr, "unable to make URI from: \"" << base << "\" and \""
228                                                                    << relative << "\"");
229 
230     return (const char *)xmlUri.get();
231 }
232 
mkXmlDoc(const string & source,bool fromFile,bool xincludes,CXmlSerializingContext & serializingContext)233 _xmlDoc *CXmlDocSource::mkXmlDoc(const string &source, bool fromFile, bool xincludes,
234                                  CXmlSerializingContext &serializingContext)
235 {
236     _xmlDoc *doc = NULL;
237     if (fromFile) {
238         doc = xmlReadFile(source.c_str(), NULL, 0);
239     } else {
240         doc = xmlReadMemory(source.c_str(), (int)source.size(), "", NULL, 0);
241     }
242 
243     if (doc == NULL) {
244         string errorMsg = "libxml failed to read";
245         if (fromFile) {
246             errorMsg += " \"" + source + "\"";
247         }
248         serializingContext.appendLineToError(errorMsg);
249 
250         return NULL;
251     }
252 
253     if (xincludes and (xmlXIncludeProcess(doc) < 0)) {
254         serializingContext.appendLineToError("libxml failed to resolve XIncludes");
255 
256         xmlFreeDoc(doc);
257         doc = NULL;
258     }
259 
260     return doc;
261 }
262