1 /*
2 * Copyright 2017-2021 the Pacemaker project contributors
3 *
4 * The version control history for this file may have further details.
5 *
6 * This source code is licensed under the GNU Lesser General Public License
7 * version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY.
8 */
9
10 #ifndef PCMK__XML_INTERNAL__H
11 # define PCMK__XML_INTERNAL__H
12
13 /*
14 * Internal-only wrappers for and extensions to libxml2 (libxslt)
15 */
16
17 # include <stdlib.h>
18 # include <stdio.h>
19 # include <string.h>
20
21 # include <crm/crm.h> /* transitively imports qblog.h */
22
23
24 /*!
25 * \brief Base for directing lib{xml2,xslt} log into standard libqb backend
26 *
27 * This macro implements the core of what can be needed for directing
28 * libxml2 or libxslt error messaging into standard, preconfigured
29 * libqb-backed log stream.
30 *
31 * It's a bit unfortunate that libxml2 (and more sparsely, also libxslt)
32 * emits a single message by chunks (location is emitted separatedly from
33 * the message itself), so we have to take the effort to combine these
34 * chunks back to single message. Whether to do this or not is driven
35 * with \p dechunk toggle.
36 *
37 * The form of a macro was chosen for implicit deriving of __FILE__, etc.
38 * and also because static dechunking buffer should be differentiated per
39 * library (here we assume different functions referring to this macro
40 * will not ever be using both at once), preferably also per-library
41 * context of use to avoid clashes altogether.
42 *
43 * Note that we cannot use qb_logt, because callsite data have to be known
44 * at the moment of compilation, which it is not always the case -- xml_log
45 * (and unfortunately there's no clear explanation of the fail to compile).
46 *
47 * Also note that there's no explicit guard against said libraries producing
48 * never-newline-terminated chunks (which would just keep consuming memory),
49 * as it's quite improbable. Termination of the program in between the
50 * same-message chunks will raise a flag with valgrind and the likes, though.
51 *
52 * And lastly, regarding how dechunking combines with other non-message
53 * parameters -- for \p priority, most important running specification
54 * wins (possibly elevated to LOG_ERR in case of nonconformance with the
55 * newline-termination "protocol"), \p dechunk is expected to always be
56 * on once it was at the start, and the rest (\p postemit and \p prefix)
57 * are picked directly from the last chunk entry finalizing the message
58 * (also reasonable to always have it the same with all related entries).
59 *
60 * \param[in] priority Syslog priority for the message to be logged
61 * \param[in] dechunk Whether to dechunk new-line terminated message
62 * \param[in] postemit Code to be executed once message is sent out
63 * \param[in] prefix How to prefix the message or NULL for raw passing
64 * \param[in] fmt Format string as with printf-like functions
65 * \param[in] ap Variable argument list to supplement \p fmt format string
66 */
67 #define PCMK__XML_LOG_BASE(priority, dechunk, postemit, prefix, fmt, ap) \
68 do { \
69 if (!(dechunk) && (prefix) == NULL) { /* quick pass */ \
70 qb_log_from_external_source_va(__func__, __FILE__, (fmt), \
71 (priority), __LINE__, 0, (ap)); \
72 (void) (postemit); \
73 } else { \
74 int CXLB_len = 0; \
75 char *CXLB_buf = NULL; \
76 static int CXLB_buffer_len = 0; \
77 static char *CXLB_buffer = NULL; \
78 static uint8_t CXLB_priority = 0; \
79 \
80 CXLB_len = vasprintf(&CXLB_buf, (fmt), (ap)); \
81 \
82 if (CXLB_len <= 0 || CXLB_buf[CXLB_len - 1] == '\n' || !(dechunk)) { \
83 if (CXLB_len < 0) { \
84 CXLB_buf = (char *) "LOG CORRUPTION HAZARD"; /*we don't modify*/\
85 CXLB_priority = QB_MIN(CXLB_priority, LOG_ERR); \
86 } else if (CXLB_len > 0 /* && (dechunk) */ \
87 && CXLB_buf[CXLB_len - 1] == '\n') { \
88 CXLB_buf[CXLB_len - 1] = '\0'; \
89 } \
90 if (CXLB_buffer) { \
91 qb_log_from_external_source(__func__, __FILE__, "%s%s%s", \
92 CXLB_priority, __LINE__, 0, \
93 (prefix) != NULL ? (prefix) : "", \
94 CXLB_buffer, CXLB_buf); \
95 free(CXLB_buffer); \
96 } else { \
97 qb_log_from_external_source(__func__, __FILE__, "%s%s", \
98 (priority), __LINE__, 0, \
99 (prefix) != NULL ? (prefix) : "", \
100 CXLB_buf); \
101 } \
102 if (CXLB_len < 0) { \
103 CXLB_buf = NULL; /* restore temporary override */ \
104 } \
105 CXLB_buffer = NULL; \
106 CXLB_buffer_len = 0; \
107 (void) (postemit); \
108 \
109 } else if (CXLB_buffer == NULL) { \
110 CXLB_buffer_len = CXLB_len; \
111 CXLB_buffer = CXLB_buf; \
112 CXLB_buf = NULL; \
113 CXLB_priority = (priority); /* remember as a running severest */ \
114 \
115 } else { \
116 CXLB_buffer = realloc(CXLB_buffer, 1 + CXLB_buffer_len + CXLB_len); \
117 memcpy(CXLB_buffer + CXLB_buffer_len, CXLB_buf, CXLB_len); \
118 CXLB_buffer_len += CXLB_len; \
119 CXLB_buffer[CXLB_buffer_len] = '\0'; \
120 CXLB_priority = QB_MIN(CXLB_priority, (priority)); /* severest? */ \
121 } \
122 free(CXLB_buf); \
123 } \
124 } while (0)
125
126 /* XML search strings for guest, remote and pacemaker_remote nodes */
127
128 /* search string to find CIB resources entries for cluster nodes */
129 #define PCMK__XP_MEMBER_NODE_CONFIG \
130 "//" XML_TAG_CIB "/" XML_CIB_TAG_CONFIGURATION "/" XML_CIB_TAG_NODES \
131 "/" XML_CIB_TAG_NODE "[not(@type) or @type='member']"
132
133 /* search string to find CIB resources entries for guest nodes */
134 #define PCMK__XP_GUEST_NODE_CONFIG \
135 "//" XML_TAG_CIB "//" XML_CIB_TAG_CONFIGURATION "//" XML_CIB_TAG_RESOURCE \
136 "//" XML_TAG_META_SETS "//" XML_CIB_TAG_NVPAIR \
137 "[@name='" XML_RSC_ATTR_REMOTE_NODE "']"
138
139 /* search string to find CIB resources entries for remote nodes */
140 #define PCMK__XP_REMOTE_NODE_CONFIG \
141 "//" XML_TAG_CIB "//" XML_CIB_TAG_CONFIGURATION "//" XML_CIB_TAG_RESOURCE \
142 "[@type='remote'][@provider='pacemaker']"
143
144 /* search string to find CIB node status entries for pacemaker_remote nodes */
145 #define PCMK__XP_REMOTE_NODE_STATUS \
146 "//" XML_TAG_CIB "//" XML_CIB_TAG_STATUS "//" XML_CIB_TAG_STATE \
147 "[@" XML_NODE_IS_REMOTE "='true']"
148
149 enum pcmk__xml_artefact_ns {
150 pcmk__xml_artefact_ns_legacy_rng = 1,
151 pcmk__xml_artefact_ns_legacy_xslt,
152 pcmk__xml_artefact_ns_base_rng,
153 pcmk__xml_artefact_ns_base_xslt,
154 };
155
156 void pcmk__strip_xml_text(xmlNode *xml);
157 const char *pcmk__xe_add_last_written(xmlNode *xe);
158
159 xmlNode *pcmk__xe_match(xmlNode *parent, const char *node_name,
160 const char *attr_n, const char *attr_v);
161
162 void pcmk__xe_remove_matching_attrs(xmlNode *element,
163 bool (*match)(xmlAttrPtr, void *),
164 void *user_data);
165
166 /*!
167 * \internal
168 * \brief Get the root directory to scan XML artefacts of given kind for
169 *
170 * \param[in] ns governs the hierarchy nesting against the inherent root dir
171 *
172 * \return root directory to scan XML artefacts of given kind for
173 */
174 char *
175 pcmk__xml_artefact_root(enum pcmk__xml_artefact_ns ns);
176
177 /*!
178 * \internal
179 * \brief Get the fully unwrapped path to particular XML artifact (RNG/XSLT)
180 *
181 * \param[in] ns denotes path forming details (parent dir, suffix)
182 * \param[in] filespec symbolic file specification to be combined with
183 * #artefact_ns to form the final path
184 * \return unwrapped path to particular XML artifact (RNG/XSLT)
185 */
186 char *pcmk__xml_artefact_path(enum pcmk__xml_artefact_ns ns,
187 const char *filespec);
188
189 /*!
190 * \internal
191 * \brief Return first non-text child node of an XML node
192 *
193 * \param[in] parent XML node to check
194 *
195 * \return First non-text child node of \p parent (or NULL if none)
196 */
197 static inline xmlNode *
pcmk__xml_first_child(const xmlNode * parent)198 pcmk__xml_first_child(const xmlNode *parent)
199 {
200 xmlNode *child = (parent? parent->children : NULL);
201
202 while (child && (child->type == XML_TEXT_NODE)) {
203 child = child->next;
204 }
205 return child;
206 }
207
208 /*!
209 * \internal
210 * \brief Return next non-text sibling node of an XML node
211 *
212 * \param[in] child XML node to check
213 *
214 * \return Next non-text sibling of \p child (or NULL if none)
215 */
216 static inline xmlNode *
pcmk__xml_next(const xmlNode * child)217 pcmk__xml_next(const xmlNode *child)
218 {
219 xmlNode *next = (child? child->next : NULL);
220
221 while (next && (next->type == XML_TEXT_NODE)) {
222 next = next->next;
223 }
224 return next;
225 }
226
227 /*!
228 * \internal
229 * \brief Return first non-text child element of an XML node
230 *
231 * \param[in] parent XML node to check
232 *
233 * \return First child element of \p parent (or NULL if none)
234 */
235 static inline xmlNode *
pcmk__xe_first_child(const xmlNode * parent)236 pcmk__xe_first_child(const xmlNode *parent)
237 {
238 xmlNode *child = (parent? parent->children : NULL);
239
240 while (child && (child->type != XML_ELEMENT_NODE)) {
241 child = child->next;
242 }
243 return child;
244 }
245
246 /*!
247 * \internal
248 * \brief Return next non-text sibling element of an XML element
249 *
250 * \param[in] child XML element to check
251 *
252 * \return Next sibling element of \p child (or NULL if none)
253 */
254 static inline xmlNode *
pcmk__xe_next(const xmlNode * child)255 pcmk__xe_next(const xmlNode *child)
256 {
257 xmlNode *next = child? child->next : NULL;
258
259 while (next && (next->type != XML_ELEMENT_NODE)) {
260 next = next->next;
261 }
262 return next;
263 }
264
265 /*!
266 * \internal
267 * \brief Like pcmk__xe_set_props, but takes a va_list instead of
268 * arguments directly.
269 */
270 void
271 pcmk__xe_set_propv(xmlNodePtr node, va_list pairs);
272
273 /*!
274 * \internal
275 * \brief Add a NULL-terminated list of name/value pairs to the given
276 * XML node as properties.
277 *
278 * \param[in,out] node XML node to add properties to
279 * \param[in] ... NULL-terminated list of name/value pairs
280 */
281 void
282 pcmk__xe_set_props(xmlNodePtr node, ...)
283 G_GNUC_NULL_TERMINATED;
284
285 /*!
286 * \internal
287 * \brief Get first attribute of an XML element
288 *
289 * \param[in] xe XML element to check
290 *
291 * \return First attribute of \p xe (or NULL if \p xe is NULL or has none)
292 */
293 static inline xmlAttr *
pcmk__xe_first_attr(const xmlNode * xe)294 pcmk__xe_first_attr(const xmlNode *xe)
295 {
296 return (xe == NULL)? NULL : xe->properties;
297 }
298
299 /*!
300 * \internal
301 * \brief Extract the ID attribute from an XML element
302 *
303 * \param[in] xpath String to search
304 * \param[in] node Node to get the ID for
305 *
306 * \return ID attribute of \p node in xpath string \p xpath
307 */
308 char *
309 pcmk__xpath_node_id(const char *xpath, const char *node);
310
311 #endif // PCMK__XML_INTERNAL__H
312