Page MenuHomeClusterLabs Projects
Files F4525570

xml_internal.h
No OneTemporary
Actions

xml_internal.h
View Options

/*
* Copyright 2017-2024 the Pacemaker project contributors
*
* The version control history for this file may have further details.
*
* This source code is licensed under the GNU Lesser General Public License
* version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY.
*/
#ifndef PCMK__XML_INTERNAL__H
# define PCMK__XML_INTERNAL__H
/*
* Internal-only wrappers for and extensions to libxml2 (libxslt)
*/
# include <stdlib.h>
# include <stdio.h>
# include <string.h>
# include <crm/crm.h> /* transitively imports qblog.h */
# include <crm/common/output_internal.h>
# include <libxml/relaxng.h>
/*!
* \brief Base for directing lib{xml2,xslt} log into standard libqb backend
*
* This macro implements the core of what can be needed for directing
* libxml2 or libxslt error messaging into standard, preconfigured
* libqb-backed log stream.
*
* It's a bit unfortunate that libxml2 (and more sparsely, also libxslt)
* emits a single message by chunks (location is emitted separatedly from
* the message itself), so we have to take the effort to combine these
* chunks back to single message. Whether to do this or not is driven
* with \p dechunk toggle.
*
* The form of a macro was chosen for implicit deriving of __FILE__, etc.
* and also because static dechunking buffer should be differentiated per
* library (here we assume different functions referring to this macro
* will not ever be using both at once), preferably also per-library
* context of use to avoid clashes altogether.
*
* Note that we cannot use qb_logt, because callsite data have to be known
* at the moment of compilation, which it is not always the case -- xml_log
* (and unfortunately there's no clear explanation of the fail to compile).
*
* Also note that there's no explicit guard against said libraries producing
* never-newline-terminated chunks (which would just keep consuming memory),
* as it's quite improbable. Termination of the program in between the
* same-message chunks will raise a flag with valgrind and the likes, though.
*
* And lastly, regarding how dechunking combines with other non-message
* parameters -- for \p priority, most important running specification
* wins (possibly elevated to LOG_ERR in case of nonconformance with the
* newline-termination "protocol"), \p dechunk is expected to always be
* on once it was at the start, and the rest (\p postemit and \p prefix)
* are picked directly from the last chunk entry finalizing the message
* (also reasonable to always have it the same with all related entries).
*
* \param[in] priority Syslog priority for the message to be logged
* \param[in] dechunk Whether to dechunk new-line terminated message
* \param[in] postemit Code to be executed once message is sent out
* \param[in] prefix How to prefix the message or NULL for raw passing
* \param[in] fmt Format string as with printf-like functions
* \param[in] ap Variable argument list to supplement \p fmt format string
*/
#define PCMK__XML_LOG_BASE(priority, dechunk, postemit, prefix, fmt, ap) \
do { \
if (!(dechunk) && (prefix) == NULL) { /* quick pass */ \
qb_log_from_external_source_va(__func__, __FILE__, (fmt), \
(priority), __LINE__, 0, (ap)); \
(void) (postemit); \
} else { \
int CXLB_len = 0; \
char *CXLB_buf = NULL; \
static int CXLB_buffer_len = 0; \
static char *CXLB_buffer = NULL; \
static uint8_t CXLB_priority = 0; \
\
CXLB_len = vasprintf(&CXLB_buf, (fmt), (ap)); \
\
if (CXLB_len <= 0 || CXLB_buf[CXLB_len - 1] == '\n' || !(dechunk)) { \
if (CXLB_len < 0) { \
CXLB_buf = (char *) "LOG CORRUPTION HAZARD"; /*we don't modify*/\
CXLB_priority = QB_MIN(CXLB_priority, LOG_ERR); \
} else if (CXLB_len > 0 /* && (dechunk) */ \
&& CXLB_buf[CXLB_len - 1] == '\n') { \
CXLB_buf[CXLB_len - 1] = '\0'; \
} \
if (CXLB_buffer) { \
qb_log_from_external_source(__func__, __FILE__, "%s%s%s", \
CXLB_priority, __LINE__, 0, \
(prefix) != NULL ? (prefix) : "", \
CXLB_buffer, CXLB_buf); \
free(CXLB_buffer); \
} else { \
qb_log_from_external_source(__func__, __FILE__, "%s%s", \
(priority), __LINE__, 0, \
(prefix) != NULL ? (prefix) : "", \
CXLB_buf); \
} \
if (CXLB_len < 0) { \
CXLB_buf = NULL; /* restore temporary override */ \
} \
CXLB_buffer = NULL; \
CXLB_buffer_len = 0; \
(void) (postemit); \
\
} else if (CXLB_buffer == NULL) { \
CXLB_buffer_len = CXLB_len; \
CXLB_buffer = CXLB_buf; \
CXLB_buf = NULL; \
CXLB_priority = (priority); /* remember as a running severest */ \
\
} else { \
CXLB_buffer = realloc(CXLB_buffer, 1 + CXLB_buffer_len + CXLB_len); \
memcpy(CXLB_buffer + CXLB_buffer_len, CXLB_buf, CXLB_len); \
CXLB_buffer_len += CXLB_len; \
CXLB_buffer[CXLB_buffer_len] = '\0'; \
CXLB_priority = QB_MIN(CXLB_priority, (priority)); /* severest? */ \
} \
free(CXLB_buf); \
} \
} while (0)
/*
* \enum pcmk__xml_fmt_options
* \brief Bit flags to control format in XML logs and dumps
*/
enum pcmk__xml_fmt_options {
//! Exclude certain XML attributes (for calculating digests)
pcmk__xml_fmt_filtered = (1 << 0),
//! Include indentation and newlines
pcmk__xml_fmt_pretty = (1 << 1),
//! Include the opening tag of an XML element, and include XML comments
pcmk__xml_fmt_open = (1 << 3),
//! Include the children of an XML element
pcmk__xml_fmt_children = (1 << 4),
//! Include the closing tag of an XML element
pcmk__xml_fmt_close = (1 << 5),
//! Include XML text nodes
pcmk__xml_fmt_text = (1 << 6),
// @COMPAT Remove when v1 patchsets are removed
//! Log a created XML subtree
pcmk__xml_fmt_diff_plus = (1 << 7),
// @COMPAT Remove when v1 patchsets are removed
//! Log a removed XML subtree
pcmk__xml_fmt_diff_minus = (1 << 8),
// @COMPAT Remove when v1 patchsets are removed
//! Log a minimal version of an XML diff (only showing the changes)
pcmk__xml_fmt_diff_short = (1 << 9),
};
int pcmk__xml_show(pcmk__output_t *out, const char *prefix, const xmlNode *data,
int depth, uint32_t options);
int pcmk__xml_show_changes(pcmk__output_t *out, const xmlNode *xml);
/* XML search strings for guest, remote and pacemaker_remote nodes */
/* search string to find CIB resources entries for cluster nodes */
#define PCMK__XP_MEMBER_NODE_CONFIG \
"//" PCMK_XE_CIB "/" PCMK_XE_CONFIGURATION "/" PCMK_XE_NODES \
"/" PCMK_XE_NODE "[not(@type) or @type='member']"
/* search string to find CIB resources entries for guest nodes */
#define PCMK__XP_GUEST_NODE_CONFIG \
"//" PCMK_XE_CIB "//" PCMK_XE_CONFIGURATION "//" PCMK_XE_PRIMITIVE \
"//" PCMK_XE_META_ATTRIBUTES "//" PCMK_XE_NVPAIR \
"[@name='" PCMK_META_REMOTE_NODE "']"
/* search string to find CIB resources entries for remote nodes */
#define PCMK__XP_REMOTE_NODE_CONFIG \
"//" PCMK_XE_CIB "//" PCMK_XE_CONFIGURATION "//" PCMK_XE_PRIMITIVE \
"[@type='remote'][@provider='pacemaker']"
/* search string to find CIB node status entries for pacemaker_remote nodes */
#define PCMK__XP_REMOTE_NODE_STATUS \
"//" PCMK_XE_CIB "//" PCMK_XE_STATUS "//" PCMK__XE_NODE_STATE \
"[@" PCMK_XA_REMOTE_NODE "='true']"
/*!
* \internal
* \brief Serialize XML (using libxml) into provided descriptor
*
* \param[in] fd File descriptor to (piece-wise) write to
* \param[in] cur XML subtree to proceed
*
* \return a standard Pacemaker return code
*/
int pcmk__xml2fd(int fd, xmlNode *cur);
enum pcmk__xml_artefact_ns {
pcmk__xml_artefact_ns_legacy_rng = 1,
pcmk__xml_artefact_ns_legacy_xslt,
pcmk__xml_artefact_ns_base_rng,
pcmk__xml_artefact_ns_base_xslt,
};
void pcmk__strip_xml_text(xmlNode *xml);
const char *pcmk__xe_add_last_written(xmlNode *xe);
xmlNode *pcmk__xe_match(const xmlNode *parent, const char *node_name,
const char *attr_n, const char *attr_v);
void pcmk__xe_remove_matching_attrs(xmlNode *element,
bool (*match)(xmlAttrPtr, void *),
void *user_data);
GString *pcmk__element_xpath(const xmlNode *xml);
/*!
* \internal
* \brief Get the root directory to scan XML artefacts of given kind for
*
* \param[in] ns governs the hierarchy nesting against the inherent root dir
*
* \return root directory to scan XML artefacts of given kind for
*/
char *
pcmk__xml_artefact_root(enum pcmk__xml_artefact_ns ns);
/*!
* \internal
* \brief Get the fully unwrapped path to particular XML artifact (RNG/XSLT)
*
* \param[in] ns denotes path forming details (parent dir, suffix)
* \param[in] filespec symbolic file specification to be combined with
* #artefact_ns to form the final path
* \return unwrapped path to particular XML artifact (RNG/XSLT)
*/
char *pcmk__xml_artefact_path(enum pcmk__xml_artefact_ns ns,
const char *filespec);
/*!
* \internal
* \brief Check whether an XML element is of a particular type
*
* \param[in] xml XML element to compare
* \param[in] name XML element name to compare
*
* \return \c true if \p xml is of type \p name, otherwise \c false
*/
static inline bool
pcmk__xe_is(const xmlNode *xml, const char *name)
{
return (xml != NULL) && (xml->name != NULL) && (name != NULL)
&& (strcmp((const char *) xml->name, name) == 0);
}
/*!
* \internal
* \brief Return first non-text child node of an XML node
*
* \param[in] parent XML node to check
*
* \return First non-text child node of \p parent (or NULL if none)
*/
static inline xmlNode *
pcmk__xml_first_child(const xmlNode *parent)
{
xmlNode *child = (parent? parent->children : NULL);
while (child && (child->type == XML_TEXT_NODE)) {
child = child->next;
}
return child;
}
/*!
* \internal
* \brief Return next non-text sibling node of an XML node
*
* \param[in] child XML node to check
*
* \return Next non-text sibling of \p child (or NULL if none)
*/
static inline xmlNode *
pcmk__xml_next(const xmlNode *child)
{
xmlNode *next = (child? child->next : NULL);
while (next && (next->type == XML_TEXT_NODE)) {
next = next->next;
}
return next;
}
/*!
* \internal
* \brief Return first non-text child element of an XML node
*
* \param[in] parent XML node to check
*
* \return First child element of \p parent (or NULL if none)
*/
static inline xmlNode *
pcmk__xe_first_child(const xmlNode *parent)
{
xmlNode *child = (parent? parent->children : NULL);
while (child && (child->type != XML_ELEMENT_NODE)) {
child = child->next;
}
return child;
}
/*!
* \internal
* \brief Return next non-text sibling element of an XML element
*
* \param[in] child XML element to check
*
* \return Next sibling element of \p child (or NULL if none)
*/
static inline xmlNode *
pcmk__xe_next(const xmlNode *child)
{
xmlNode *next = child? child->next : NULL;
while (next && (next->type != XML_ELEMENT_NODE)) {
next = next->next;
}
return next;
}
/*!
* \internal
* \brief Like pcmk__xe_set_props, but takes a va_list instead of
* arguments directly.
*
* \param[in,out] node XML to add attributes to
* \param[in] pairs NULL-terminated list of name/value pairs to add
*/
void
pcmk__xe_set_propv(xmlNodePtr node, va_list pairs);
/*!
* \internal
* \brief Add a NULL-terminated list of name/value pairs to the given
* XML node as properties.
*
* \param[in,out] node XML node to add properties to
* \param[in] ... NULL-terminated list of name/value pairs
*
* \note A NULL name terminates the arguments; a NULL value will be skipped.
*/
void
pcmk__xe_set_props(xmlNodePtr node, ...)
G_GNUC_NULL_TERMINATED;
/*!
* \internal
* \brief Get first attribute of an XML element
*
* \param[in] xe XML element to check
*
* \return First attribute of \p xe (or NULL if \p xe is NULL or has none)
*/
static inline xmlAttr *
pcmk__xe_first_attr(const xmlNode *xe)
{
return (xe == NULL)? NULL : xe->properties;
}
/*!
* \internal
* \brief Extract the ID attribute from an XML element
*
* \param[in] xpath String to search
* \param[in] node Node to get the ID for
*
* \return ID attribute of \p node in xpath string \p xpath
*/
char *
pcmk__xpath_node_id(const char *xpath, const char *node);
/* internal XML-related utilities */
enum xml_private_flags {
pcmk__xf_none = 0x0000,
pcmk__xf_dirty = 0x0001,
pcmk__xf_deleted = 0x0002,
pcmk__xf_created = 0x0004,
pcmk__xf_modified = 0x0008,
pcmk__xf_tracking = 0x0010,
pcmk__xf_processed = 0x0020,
pcmk__xf_skip = 0x0040,
pcmk__xf_moved = 0x0080,
pcmk__xf_acl_enabled = 0x0100,
pcmk__xf_acl_read = 0x0200,
pcmk__xf_acl_write = 0x0400,
pcmk__xf_acl_deny = 0x0800,
pcmk__xf_acl_create = 0x1000,
pcmk__xf_acl_denied = 0x2000,
pcmk__xf_lazy = 0x4000,
};
void pcmk__set_xml_doc_flag(xmlNode *xml, enum xml_private_flags flag);
/*!
* \internal
* \brief Iterate over child elements of \p xml
*
* This function iterates over the children of \p xml, performing the
* callback function \p handler on each node. If the callback returns
* a value other than pcmk_rc_ok, the iteration stops and the value is
* returned. It is therefore possible that not all children will be
* visited.
*
* \param[in,out] xml The starting XML node. Can be NULL.
* \param[in] child_element_name The name that the node must match in order
* for \p handler to be run. If NULL, all
* child elements will match.
* \param[in] handler The callback function.
* \param[in,out] userdata User data to pass to the callback function.
* Can be NULL.
*
* \return Standard Pacemaker return code
*/
int
pcmk__xe_foreach_child(xmlNode *xml, const char *child_element_name,
int (*handler)(xmlNode *xml, void *userdata),
void *userdata);
static inline const char *
pcmk__xml_attr_value(const xmlAttr *attr)
{
return ((attr == NULL) || (attr->children == NULL))? NULL
: (const char *) attr->children->content;
}
gboolean pcmk__validate_xml(xmlNode *xml_blob, const char *validation,
xmlRelaxNGValidityErrorFunc error_handler,
void *error_handler_context);
void pcmk__log_known_schemas(void);
const char *pcmk__remote_schema_dir(void);
void pcmk__sort_schemas(void);
#endif // PCMK__XML_INTERNAL__H

File Metadata

Mime Type
text/x-c
Expires
Thu, Jun 26, 7:17 PM (1 d, 4 h)
Storage Engine
blob
Storage Format
Raw Data
Storage Handle
1959524
Default Alt Text
xml_internal.h (17 KB)

Event Timeline