/* * Copyright 2017-2020 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 # include # include # include /* transitively imports qblog.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_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(xmlNode *parent, const char *node_name, const char *attr_n, const char *attr_v); /*! * \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 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; } #endif // PCMK__XML_INTERNAL__H