nvpair.c

Go to the documentation of this file.

/*
 * Copyright 2004-2025 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 <stdint.h>         // UINT32_MAX
#include <inttypes.h>       // PRIu32
#include <sys/types.h>
#include <string.h>
#include <ctype.h>
#include <glib.h>           // gchar, gint, etc.
#include <libxml/tree.h>
 
#include <crm/crm.h>
#include <crm/common/xml.h>
#include <crm/common/xml_internal.h>
#include "crmcommon_private.h"
 
/*
 * This file isolates handling of various kinds of name/value pairs:
 *
 * - pcmk_nvpair_t data type
 * - name=value strings
 * - XML nvpair elements (<nvpair id=ID name=NAME value=VALUE>)
 * - Instance attributes and meta-attributes (for resources and actions)
 */
 
// pcmk_nvpair_t handling
 
static pcmk_nvpair_t *
pcmk__new_nvpair(const char *name, const char *value)
{
    pcmk_nvpair_t *nvpair = NULL;
 
    pcmk__assert(name);
 
    nvpair = pcmk__assert_alloc(1, sizeof(pcmk_nvpair_t));
 
    nvpair->name = pcmk__str_copy(name);
    nvpair->value = pcmk__str_copy(value);
    return nvpair;
}
 
static void
pcmk__free_nvpair(gpointer data)
{
    if (data) {
        pcmk_nvpair_t *nvpair = data;
 
        free(nvpair->name);
        free(nvpair->value);
        free(nvpair);
    }
}
 
GSList *
pcmk_prepend_nvpair(GSList *nvpairs, const char *name, const char *value)
{
    return g_slist_prepend(nvpairs, pcmk__new_nvpair(name, value));
}
 
void
pcmk_free_nvpairs(GSList *nvpairs)
{
    g_slist_free_full(nvpairs, pcmk__free_nvpair);
}
 
 
// name=value string handling
 
int
pcmk__scan_nvpair(const gchar *input, gchar **name, gchar **value)
{
    gchar **nvpair = NULL;
    int rc = pcmk_rc_ok;
 
    pcmk__assert(input != NULL);
    pcmk__assert((name != NULL) && (*name == NULL));
    pcmk__assert((value != NULL) && (*value == NULL));
 
    nvpair = g_strsplit(input, "=", 2);
 
    /* Check whether nvpair is well-formed (short-circuits if input was split
     * into fewer than 2 tokens)
     */
    if (pcmk__str_empty(nvpair[0]) || pcmk__str_empty(nvpair[1])) {
        rc = pcmk_rc_bad_nvpair;
        goto done;
    }
 
    *name = nvpair[0];
    *value = nvpair[1];
    pcmk__trim((char *) *value);
 
    // name and value took ownership
    nvpair[0] = NULL;
    nvpair[1] = NULL;
 
done:
    g_strfreev(nvpair);
    return rc;
}
 
char *
pcmk__format_nvpair(const char *name, const char *value, const char *units)
{
    return crm_strdup_printf("%s=\"%s%s\"", name, value, units ? units : "");
}
 
void
hash2smartfield(gpointer key, gpointer value, gpointer user_data)
{
    /* @TODO Generate PCMK__XE_PARAM nodes for all keys that aren't valid XML
     * attribute names (not just those that start with digits), or possibly for
     * all keys to simplify parsing.
     *
     * Consider either deprecating as public API or exposing PCMK__XE_PARAM.
     * PCMK__XE_PARAM is currently private because it doesn't appear in any
     * output that Pacemaker generates.
     */
    const char *name = key;
    const char *s_value = value;
 
    xmlNode *xml_node = user_data;
 
    if (isdigit(name[0])) {
        xmlNode *tmp = pcmk__xe_create(xml_node, PCMK__XE_PARAM);
 
        crm_xml_add(tmp, PCMK_XA_NAME, name);
        crm_xml_add(tmp, PCMK_XA_VALUE, s_value);
 
    } else if (crm_element_value(xml_node, name) == NULL) {
        crm_xml_add(xml_node, name, s_value);
        crm_trace("dumped: %s=%s", name, s_value);
 
    } else {
        crm_trace("duplicate: %s=%s", name, s_value);
    }
}
 
void
hash2field(gpointer key, gpointer value, gpointer user_data)
{
    const char *name = key;
    const char *s_value = value;
 
    xmlNode *xml_node = user_data;
 
    if (crm_element_value(xml_node, name) == NULL) {
        crm_xml_add(xml_node, name, s_value);
 
    } else {
        crm_trace("duplicate: %s=%s", name, s_value);
    }
}
 
void
hash2metafield(gpointer key, gpointer value, gpointer user_data)
{
    char *crm_name = NULL;
 
    if (key == NULL || value == NULL) {
        return;
    }
 
    /* Filter out cluster-generated attributes that contain a '#' or ':'
     * (like fail-count and last-failure).
     */
    for (crm_name = key; *crm_name; ++crm_name) {
        if ((*crm_name == '#') || (*crm_name == ':')) {
            return;
        }
    }
 
    crm_name = crm_meta_name(key);
    hash2field(crm_name, value, user_data);
    free(crm_name);
}
 
// nvpair handling
 
xmlNode *
crm_create_nvpair_xml(xmlNode *parent, const char *id, const char *name,
                      const char *value)
{
    xmlNode *nvp;
 
    /* id can be NULL so we auto-generate one, and name can be NULL if this
     * will be used to delete a name/value pair by ID, but both can't be NULL
     */
    CRM_CHECK(id || name, return NULL);
 
    nvp = pcmk__xe_create(parent, PCMK_XE_NVPAIR);
 
    if (id) {
        crm_xml_add(nvp, PCMK_XA_ID, id);
    } else {
        pcmk__xe_set_id(nvp, "%s-%s",
                        pcmk__s(pcmk__xe_id(parent), PCMK_XE_NVPAIR), name);
    }
    crm_xml_add(nvp, PCMK_XA_NAME, name);
    crm_xml_add(nvp, PCMK_XA_VALUE, value);
    return nvp;
}
 
GHashTable *
xml2list(const xmlNode *parent)
{
    xmlNode *child = NULL;
    xmlAttrPtr pIter = NULL;
    xmlNode *nvpair_list = NULL;
    GHashTable *nvpair_hash = pcmk__strkey_table(free, free);
 
    CRM_CHECK(parent != NULL, return nvpair_hash);
 
    nvpair_list = pcmk__xe_first_child(parent, PCMK__XE_ATTRIBUTES, NULL, NULL);
    if (nvpair_list == NULL) {
        crm_trace("No attributes in %s", parent->name);
        crm_log_xml_trace(parent, "No attributes for resource op");
    }
 
    crm_log_xml_trace(nvpair_list, "Unpacking");
 
    for (pIter = pcmk__xe_first_attr(nvpair_list); pIter != NULL;
         pIter = pIter->next) {
 
        const char *p_name = (const char *)pIter->name;
        const char *p_value = pcmk__xml_attr_value(pIter);
 
        crm_trace("Added %s=%s", p_name, p_value);
 
        pcmk__insert_dup(nvpair_hash, p_name, p_value);
    }
 
    for (child = pcmk__xe_first_child(nvpair_list, PCMK__XE_PARAM, NULL, NULL);
         child != NULL; child = pcmk__xe_next(child, PCMK__XE_PARAM)) {
 
        const char *key = crm_element_value(child, PCMK_XA_NAME);
        const char *value = crm_element_value(child, PCMK_XA_VALUE);
 
        crm_trace("Added %s=%s", key, value);
        if (key != NULL && value != NULL) {
            pcmk__insert_dup(nvpair_hash, key, value);
        }
    }
 
    return nvpair_hash;
}
 
static int
unpack_nvpair(xmlNode *nvpair, void *userdata)
{
    pcmk__nvpair_unpack_t *unpack_data = userdata;
 
    const char *name = NULL;
    const char *value = NULL;
    const char *old_value = NULL;
    const xmlNode *ref_nvpair = pcmk__xe_resolve_idref(nvpair, NULL);
 
    if (ref_nvpair == NULL) {
        /* Not possible with schema validation enabled (error already
         * logged)
         */
        return pcmk_rc_ok;
    }
 
    name = crm_element_value(ref_nvpair, PCMK_XA_NAME);
    value = crm_element_value(ref_nvpair, PCMK_XA_VALUE);
    if ((name == NULL) || (value == NULL)) {
        return pcmk_rc_ok; // Not possible with schema validation enabled
    }
 
    old_value = g_hash_table_lookup(unpack_data->values, name);
 
    if (pcmk__str_eq(value, "#default", pcmk__str_casei)) {
        // @COMPAT Deprecated since 2.1.8
        pcmk__config_warn("Support for setting meta-attributes (such as "
                          "%s) to the explicit value '#default' is "
                          "deprecated and will be removed in a future "
                          "release", name);
        if (old_value != NULL) {
            g_hash_table_remove(unpack_data->values, name);
        }
 
    } else if ((old_value == NULL) || unpack_data->overwrite) {
        crm_trace("Setting %s=\"%s\" (was %s)",
                  name, value, pcmk__s(old_value, "unset"));
        pcmk__insert_dup(unpack_data->values, name, value);
    }
    return pcmk_rc_ok;
}
 
void
pcmk__unpack_nvpair_block(gpointer data, gpointer user_data)
{
    xmlNode *pair = data;
    pcmk__nvpair_unpack_t *unpack_data = user_data;
 
    xmlNode *rule_xml = NULL;
 
    pcmk__assert((pair != NULL) && (unpack_data != NULL)
                 && (unpack_data->values != NULL));
 
    rule_xml = pcmk__xe_first_child(pair, PCMK_XE_RULE, NULL, NULL);
    if ((rule_xml != NULL)
        && (pcmk_evaluate_rule(rule_xml, &(unpack_data->rule_input),
                               unpack_data->next_change) != pcmk_rc_ok)) {
        return;
    }
 
    crm_trace("Adding name/value pairs from %s %s overwrite",
              pcmk__xe_id(pair), (unpack_data->overwrite? "with" : "without"));
    if (pcmk__xe_is(pair->children, PCMK__XE_ATTRIBUTES)) {
        pair = pair->children;
    }
    pcmk__xe_foreach_child(pair, PCMK_XE_NVPAIR, unpack_nvpair, unpack_data);
}
 
void
pcmk_unpack_nvpair_blocks(const xmlNode *xml, const char *element_name,
                          const char *first_id,
                          const pcmk_rule_input_t *rule_input,
                          GHashTable *values, crm_time_t *next_change)
{
    GList *blocks = pcmk__xe_dereference_children(xml, element_name);
 
    if (blocks != NULL) {
        pcmk__nvpair_unpack_t data = {
            .values = values,
            .first_id = first_id,
            .rule_input = {
                .now = NULL,
            },
            .overwrite = false,
            .next_change = next_change,
        };
 
        if (rule_input != NULL) {
            data.rule_input = *rule_input;
        }
        blocks = g_list_sort_with_data(blocks, pcmk__cmp_nvpair_blocks, &data);
        g_list_foreach(blocks, pcmk__unpack_nvpair_block, &data);
        g_list_free(blocks);
    }
}
 
 
// Meta-attribute handling
 
char *
crm_meta_name(const char *attr_name)
{
    char *env_name = NULL;
 
    pcmk__assert(!pcmk__str_empty(attr_name));
 
    env_name = crm_strdup_printf(CRM_META "_%s", attr_name);
    for (char *c = env_name; *c != '\0'; ++c) {
        if (*c == '-') {
            *c = '_';
        }
    }
    return env_name;
}
 
const char *
crm_meta_value(GHashTable *meta, const char *attr_name)
{
    if ((meta != NULL) && (attr_name != NULL)) {
        char *key = crm_meta_name(attr_name);
        const char *value = g_hash_table_lookup(meta, key);
 
        free(key);
        return value;
    }
    return NULL;
}
 
gint
pcmk__cmp_nvpair_blocks(gconstpointer a, gconstpointer b, gpointer user_data)
{
    const xmlNode *pair_a = a;
    const xmlNode *pair_b = b;
    const pcmk__nvpair_unpack_t *unpack_data = user_data;
 
    int score_a = 0;
    int score_b = 0;
    int rc = pcmk_rc_ok;
 
    /* If we're overwriting values, we want to process blocks from
     * lowest priority to highest, so higher-priority values overwrite
     * lower-priority ones. If we're not overwriting values, we want to process
     * from highest priority to lowest.
     */
    const gint a_is_higher = ((unpack_data != NULL)
                              && unpack_data->overwrite)? 1 : -1;
    const gint b_is_higher = -a_is_higher;
 
    /* NULL values have lowest priority, regardless of the other's score
     * (it won't be possible in practice anyway, this is just a failsafe)
     */
    if (a == NULL) {
        return (b == NULL)? 0 : b_is_higher;
 
    } else if (b == NULL) {
        return a_is_higher;
    }
 
    /* A particular XML ID can be specified as having highest priority
     * regardless of score (schema validation, if enabled, prevents two blocks
     * from having the same ID, so we can ignore handling that case
     * specifically)
     */
    if ((unpack_data != NULL) && (unpack_data->first_id != NULL)) {
        if (pcmk__str_eq(pcmk__xe_id(pair_a), unpack_data->first_id,
                         pcmk__str_none)) {
            return a_is_higher;
 
        } else if (pcmk__str_eq(pcmk__xe_id(pair_b), unpack_data->first_id,
                                pcmk__str_none)) {
            return b_is_higher;
        }
    }
 
    // Otherwise, check the scores
 
    rc = pcmk__xe_get_score(pair_a, PCMK_XA_SCORE, &score_a, 0);
    if (rc != pcmk_rc_ok) { // Not possible with schema validation enabled
        pcmk__config_warn("Using 0 as %s score because '%s' "
                          "is not a valid score: %s",
                          pcmk__xe_id(pair_a),
                          crm_element_value(pair_a, PCMK_XA_SCORE),
                          pcmk_rc_str(rc));
    }
 
    rc = pcmk__xe_get_score(pair_b, PCMK_XA_SCORE, &score_b, 0);
    if (rc != pcmk_rc_ok) { // Not possible with schema validation enabled
        pcmk__config_warn("Using 0 as %s score because '%s' "
                          "is not a valid score: %s",
                          pcmk__xe_id(pair_b),
                          crm_element_value(pair_b, PCMK_XA_SCORE),
                          pcmk_rc_str(rc));
    }
 
    if (score_a < score_b) {
        return b_is_higher;
 
    } else if (score_a > score_b) {
        return a_is_higher;
    }
    return 0;
}
 
// Deprecated functions kept only for backward API compatibility
// LCOV_EXCL_START
 
#include <crm/common/nvpair_compat.h>
 
static gint
pcmk__compare_nvpair(gconstpointer a, gconstpointer b)
{
    int rc = 0;
    const pcmk_nvpair_t *pair_a = a;
    const pcmk_nvpair_t *pair_b = b;
 
    pcmk__assert((pair_a != NULL) && (pair_a->name != NULL)
                 && (pair_b != NULL) && (pair_b->name != NULL));
 
    rc = strcmp(pair_a->name, pair_b->name);
    if (rc < 0) {
        return -1;
    } else if (rc > 0) {
        return 1;
    }
    return 0;
}
 
GSList *
pcmk_sort_nvpairs(GSList *list)
{
    return g_slist_sort(list, pcmk__compare_nvpair);
}
 
GSList *
pcmk_xml_attrs2nvpairs(const xmlNode *xml)
{
    GSList *result = NULL;
 
    for (xmlAttrPtr iter = pcmk__xe_first_attr(xml); iter != NULL;
         iter = iter->next) {
 
        result = pcmk_prepend_nvpair(result,
                                     (const char *) iter->name,
                                     (const char *) pcmk__xml_attr_value(iter));
    }
    return result;
}
 
static void
pcmk__nvpair_add_xml_attr(gpointer data, gpointer user_data)
{
    pcmk_nvpair_t *pair = data;
    xmlNode *parent = user_data;
 
    crm_xml_add(parent, pair->name, pair->value);
}
 
void
pcmk_nvpairs2xml_attrs(GSList *list, xmlNode *xml)
{
    g_slist_foreach(list, pcmk__nvpair_add_xml_attr, xml);
}
 
void
hash2nvpair(gpointer key, gpointer value, gpointer user_data)
{
    const char *name = key;
    const char *s_value = value;
    xmlNode *xml_node = user_data;
 
    crm_create_nvpair_xml(xml_node, name, name, s_value);
    crm_trace("dumped: name=%s value=%s", name, s_value);
}
 
// LCOV_EXCL_STOP
// End deprecated API