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/*
* Copyright 2015-2022 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.
*/
#include <crm_internal.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <md5.h>
#include <crm/crm.h>
#include <crm/msg_xml.h>
#include <crm/common/xml.h>
#include "crmcommon_private.h"
#define BEST_EFFORT_STATUS 0
/*!
* \internal
* \brief Dump XML in a format used with v1 digests
*
* \param[in] xml Root of XML to dump
*
* \return Newly allocated buffer containing dumped XML
*/
static GString *
dump_xml_for_digest(xmlNodePtr xml)
{
GString *buffer = g_string_sized_new(1024);
/* for compatibility with the old result which is used for v1 digests */
g_string_append_c(buffer, ' ');
pcmk__xml2text(xml, 0, buffer, 0);
g_string_append_c(buffer, '\n');
return buffer;
}
/*!
* \brief Calculate and return v1 digest of XML tree
*
* \param[in] input Root of XML to digest
* \param[in] sort Whether to sort the XML before calculating digest
* \param[in] ignored Not used
*
* \return Newly allocated string containing digest
* \note Example return value: "c048eae664dba840e1d2060f00299e9d"
*/
static char *
calculate_xml_digest_v1(xmlNode *input, gboolean sort, gboolean ignored)
{
char *digest = NULL;
GString *buffer = NULL;
xmlNode *copy = NULL;
if (sort) {
crm_trace("Sorting xml...");
copy = sorted_xml(input, NULL, TRUE);
crm_trace("Done");
input = copy;
}
buffer = dump_xml_for_digest(input);
CRM_CHECK(buffer->len > 0, free_xml(copy);
g_string_free(buffer, TRUE);
return NULL);
digest = crm_md5sum((const char *) buffer->str);
crm_log_xml_trace(input, "digest:source");
g_string_free(buffer, TRUE);
free_xml(copy);
return digest;
}
/*!
* \brief Calculate and return v2 digest of XML tree
*
* \param[in] source Root of XML to digest
* \param[in] do_filter Whether to filter certain XML attributes
*
* \return Newly allocated string containing digest
*/
static char *
calculate_xml_digest_v2(xmlNode *source, gboolean do_filter)
{
char *digest = NULL;
GString *buffer = g_string_sized_new(1024);
static struct qb_log_callsite *digest_cs = NULL;
crm_trace("Begin digest %s", do_filter?"filtered":"");
pcmk__xml2text(source, (do_filter? xml_log_option_filtered : 0), buffer, 0);
CRM_ASSERT(buffer != NULL);
digest = crm_md5sum((const char *) buffer->str);
if (digest_cs == NULL) {
digest_cs = qb_log_callsite_get(__func__, __FILE__, "cib-digest", LOG_TRACE, __LINE__,
crm_trace_nonlog);
}
if (digest_cs && digest_cs->targets) {
char *trace_file = crm_strdup_printf("%s/digest-%s",
pcmk__get_tmpdir(), digest);
crm_trace("Saving %s.%s.%s to %s",
crm_element_value(source, XML_ATTR_GENERATION_ADMIN),
crm_element_value(source, XML_ATTR_GENERATION),
crm_element_value(source, XML_ATTR_NUMUPDATES), trace_file);
save_xml_to_file(source, "digest input", trace_file);
free(trace_file);
}
g_string_free(buffer, TRUE);
crm_trace("End digest");
return digest;
}
/*!
* \brief Calculate and return digest of XML tree, suitable for storing on disk
*
* \param[in] input Root of XML to digest
*
* \return Newly allocated string containing digest
*/
char *
calculate_on_disk_digest(xmlNode *input)
{
/* Always use the v1 format for on-disk digests
* a) it's a compatibility nightmare
* b) we only use this once at startup, all other
* invocations are in a separate child process
*/
return calculate_xml_digest_v1(input, FALSE, FALSE);
}
/*!
* \brief Calculate and return digest of XML operation
*
* \param[in] input Root of XML to digest
* \param[in] version Unused
*
* \return Newly allocated string containing digest
*/
char *
calculate_operation_digest(xmlNode *input, const char *version)
{
/* We still need the sorting for operation digests */
return calculate_xml_digest_v1(input, TRUE, FALSE);
}
/*!
* \brief Calculate and return digest of XML tree
*
* \param[in] input Root of XML to digest
* \param[in] sort Whether to sort XML before calculating digest
* \param[in] do_filter Whether to filter certain XML attributes
* \param[in] version CRM feature set version (used to select v1/v2 digest)
*
* \return Newly allocated string containing digest
*/
char *
calculate_xml_versioned_digest(xmlNode *input, gboolean sort,
gboolean do_filter, const char *version)
{
/*
* @COMPAT digests (on-disk or in diffs/patchsets) created <1.1.4;
* removing this affects even full-restart upgrades from old versions
*
* The sorting associated with v1 digest creation accounted for 23% of
* the CIB manager's CPU usage on the server. v2 drops this.
*
* The filtering accounts for an additional 2.5% and we may want to
* remove it in future.
*
* v2 also uses the xmlBuffer contents directly to avoid additional copying
*/
if (version == NULL || compare_version("3.0.5", version) > 0) {
crm_trace("Using v1 digest algorithm for %s",
pcmk__s(version, "unknown feature set"));
return calculate_xml_digest_v1(input, sort, do_filter);
}
crm_trace("Using v2 digest algorithm for %s",
pcmk__s(version, "unknown feature set"));
return calculate_xml_digest_v2(input, do_filter);
}
/*!
* \internal
* \brief Check whether calculated digest of given XML matches expected digest
*
* \param[in] input Root of XML tree to digest
* \param[in] expected Expected digest in on-disk format
*
* \return true if digests match, false on mismatch or error
*/
bool
pcmk__verify_digest(xmlNode *input, const char *expected)
{
char *calculated = NULL;
bool passed;
if (input != NULL) {
calculated = calculate_on_disk_digest(input);
if (calculated == NULL) {
crm_perror(LOG_ERR, "Could not calculate digest for comparison");
return false;
}
}
passed = pcmk__str_eq(expected, calculated, pcmk__str_casei);
if (passed) {
crm_trace("Digest comparison passed: %s", calculated);
} else {
crm_err("Digest comparison failed: expected %s, calculated %s",
expected, calculated);
}
free(calculated);
return passed;
}
/*!
* \internal
* \brief Check whether an XML attribute should be excluded from CIB digests
*
* \param[in] name XML attribute name
*
* \return true if XML attribute should be excluded from CIB digest calculation
*/
bool
pcmk__xa_filterable(const char *name)
{
static const char *filter[] = {
XML_ATTR_ORIGIN,
XML_CIB_ATTR_WRITTEN,
XML_ATTR_UPDATE_ORIG,
XML_ATTR_UPDATE_CLIENT,
XML_ATTR_UPDATE_USER,
};
for (int i = 0; i < PCMK__NELEM(filter); i++) {
if (strcmp(name, filter[i]) == 0) {
return true;
}
}
return false;
}
char *
crm_md5sum(const char *buffer)
{
int lpc = 0, len = 0;
char *digest = NULL;
unsigned char raw_digest[MD5_DIGEST_SIZE];
if (buffer == NULL) {
buffer = "";
}
len = strlen(buffer);
crm_trace("Beginning digest of %d bytes", len);
digest = malloc(2 * MD5_DIGEST_SIZE + 1);
if (digest) {
md5_buffer(buffer, len, raw_digest);
for (lpc = 0; lpc < MD5_DIGEST_SIZE; lpc++) {
sprintf(digest + (2 * lpc), "%02x", raw_digest[lpc]);
}
digest[(2 * MD5_DIGEST_SIZE)] = 0;
crm_trace("Digest %s.", digest);
} else {
crm_err("Could not create digest");
}
return digest;
}

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