1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
|
/*
* contrib/xml2/xslt_proc.c
*
* XSLT processing functions (requiring libxslt)
*
* John Gray, for Torchbox 2003-04-01
*/
#include "postgres.h"
#include "fmgr.h"
#include "utils/builtins.h"
#include "utils/xml.h"
#ifdef USE_LIBXSLT
/* libxml includes */
#include <libxml/xpath.h>
#include <libxml/tree.h>
#include <libxml/xmlmemory.h>
/* libxslt includes */
#include <libxslt/xslt.h>
#include <libxslt/xsltInternals.h>
#include <libxslt/security.h>
#include <libxslt/transform.h>
#include <libxslt/xsltutils.h>
#endif /* USE_LIBXSLT */
#ifdef USE_LIBXSLT
/* declarations to come from xpath.c */
extern PgXmlErrorContext *pgxml_parser_init(PgXmlStrictness strictness);
/* local defs */
static const char **parse_params(text *paramstr);
#endif /* USE_LIBXSLT */
PG_FUNCTION_INFO_V1(xslt_process);
Datum
xslt_process(PG_FUNCTION_ARGS)
{
#ifdef USE_LIBXSLT
text *doct = PG_GETARG_TEXT_PP(0);
text *ssheet = PG_GETARG_TEXT_PP(1);
text *result;
text *paramstr;
const char **params;
PgXmlErrorContext *xmlerrcxt;
volatile xsltStylesheetPtr stylesheet = NULL;
volatile xmlDocPtr doctree = NULL;
volatile xmlDocPtr restree = NULL;
volatile xsltSecurityPrefsPtr xslt_sec_prefs = NULL;
volatile xsltTransformContextPtr xslt_ctxt = NULL;
volatile int resstat = -1;
xmlChar *resstr = NULL;
int reslen = 0;
if (fcinfo->nargs == 3)
{
paramstr = PG_GETARG_TEXT_PP(2);
params = parse_params(paramstr);
}
else
{
/* No parameters */
params = (const char **) palloc(sizeof(char *));
params[0] = NULL;
}
/* Setup parser */
xmlerrcxt = pgxml_parser_init(PG_XML_STRICTNESS_LEGACY);
PG_TRY();
{
xmlDocPtr ssdoc;
bool xslt_sec_prefs_error;
/* Parse document */
doctree = xmlReadMemory((char *) VARDATA_ANY(doct),
VARSIZE_ANY_EXHDR(doct), NULL, NULL,
XML_PARSE_NOENT);
if (doctree == NULL)
xml_ereport(xmlerrcxt, ERROR, ERRCODE_INVALID_XML_DOCUMENT,
"error parsing XML document");
/* Same for stylesheet */
ssdoc = xmlReadMemory((char *) VARDATA_ANY(ssheet),
VARSIZE_ANY_EXHDR(ssheet), NULL, NULL,
XML_PARSE_NOENT);
if (ssdoc == NULL)
xml_ereport(xmlerrcxt, ERROR, ERRCODE_INVALID_XML_DOCUMENT,
"error parsing stylesheet as XML document");
/* After this call we need not free ssdoc separately */
stylesheet = xsltParseStylesheetDoc(ssdoc);
if (stylesheet == NULL)
xml_ereport(xmlerrcxt, ERROR, ERRCODE_INVALID_ARGUMENT_FOR_XQUERY,
"failed to parse stylesheet");
xslt_ctxt = xsltNewTransformContext(stylesheet, doctree);
xslt_sec_prefs_error = false;
if ((xslt_sec_prefs = xsltNewSecurityPrefs()) == NULL)
xslt_sec_prefs_error = true;
if (xsltSetSecurityPrefs(xslt_sec_prefs, XSLT_SECPREF_READ_FILE,
xsltSecurityForbid) != 0)
xslt_sec_prefs_error = true;
if (xsltSetSecurityPrefs(xslt_sec_prefs, XSLT_SECPREF_WRITE_FILE,
xsltSecurityForbid) != 0)
xslt_sec_prefs_error = true;
if (xsltSetSecurityPrefs(xslt_sec_prefs, XSLT_SECPREF_CREATE_DIRECTORY,
xsltSecurityForbid) != 0)
xslt_sec_prefs_error = true;
if (xsltSetSecurityPrefs(xslt_sec_prefs, XSLT_SECPREF_READ_NETWORK,
xsltSecurityForbid) != 0)
xslt_sec_prefs_error = true;
if (xsltSetSecurityPrefs(xslt_sec_prefs, XSLT_SECPREF_WRITE_NETWORK,
xsltSecurityForbid) != 0)
xslt_sec_prefs_error = true;
if (xsltSetCtxtSecurityPrefs(xslt_sec_prefs, xslt_ctxt) != 0)
xslt_sec_prefs_error = true;
if (xslt_sec_prefs_error)
ereport(ERROR,
(errmsg("could not set libxslt security preferences")));
restree = xsltApplyStylesheetUser(stylesheet, doctree, params,
NULL, NULL, xslt_ctxt);
if (restree == NULL)
xml_ereport(xmlerrcxt, ERROR, ERRCODE_INVALID_ARGUMENT_FOR_XQUERY,
"failed to apply stylesheet");
resstat = xsltSaveResultToString(&resstr, &reslen, restree, stylesheet);
}
PG_CATCH();
{
if (restree != NULL)
xmlFreeDoc(restree);
if (xslt_ctxt != NULL)
xsltFreeTransformContext(xslt_ctxt);
if (xslt_sec_prefs != NULL)
xsltFreeSecurityPrefs(xslt_sec_prefs);
if (stylesheet != NULL)
xsltFreeStylesheet(stylesheet);
if (doctree != NULL)
xmlFreeDoc(doctree);
xsltCleanupGlobals();
pg_xml_done(xmlerrcxt, true);
PG_RE_THROW();
}
PG_END_TRY();
xmlFreeDoc(restree);
xsltFreeTransformContext(xslt_ctxt);
xsltFreeSecurityPrefs(xslt_sec_prefs);
xsltFreeStylesheet(stylesheet);
xmlFreeDoc(doctree);
xsltCleanupGlobals();
pg_xml_done(xmlerrcxt, false);
/* XXX this is pretty dubious, really ought to throw error instead */
if (resstat < 0)
PG_RETURN_NULL();
result = cstring_to_text_with_len((char *) resstr, reslen);
if (resstr)
xmlFree(resstr);
PG_RETURN_TEXT_P(result);
#else /* !USE_LIBXSLT */
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("xslt_process() is not available without libxslt")));
PG_RETURN_NULL();
#endif /* USE_LIBXSLT */
}
#ifdef USE_LIBXSLT
static const char **
parse_params(text *paramstr)
{
char *pos;
char *pstr;
char *nvsep = "=";
char *itsep = ",";
const char **params;
int max_params;
int nparams;
pstr = text_to_cstring(paramstr);
max_params = 20; /* must be even! */
params = (const char **) palloc((max_params + 1) * sizeof(char *));
nparams = 0;
pos = pstr;
while (*pos != '\0')
{
if (nparams >= max_params)
{
max_params *= 2;
params = (const char **) repalloc(params,
(max_params + 1) * sizeof(char *));
}
params[nparams++] = pos;
pos = strstr(pos, nvsep);
if (pos != NULL)
{
*pos = '\0';
pos++;
}
else
{
/* No equal sign, so ignore this "parameter" */
nparams--;
break;
}
/* since max_params is even, we still have nparams < max_params */
params[nparams++] = pos;
pos = strstr(pos, itsep);
if (pos != NULL)
{
*pos = '\0';
pos++;
}
else
break;
}
/* Add the terminator marker; we left room for it in the palloc's */
params[nparams] = NULL;
return params;
}
#endif /* USE_LIBXSLT */
|
