ipc_attrd.c

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/*
 * Copyright 2011-2025 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 <libxml/xmlstring.h>               // xmlChar
 
#include <crm/crm.h>
#include <crm/common/attrs_internal.h>
#include <crm/common/ipc.h>
#include <crm/common/ipc_attrd_internal.h>
#include <crm/common/xml.h>
#include "crmcommon_private.h"
 
static void
set_pairs_data(pcmk__attrd_api_reply_t *data, xmlNode *msg_data)
{
    const char *name = NULL;
    pcmk__attrd_query_pair_t *pair;
 
    name = crm_element_value(msg_data, PCMK__XA_ATTR_NAME);
 
    for (xmlNode *node = pcmk__xe_first_child(msg_data, PCMK_XE_NODE, NULL,
                                              NULL);
         node != NULL; node = pcmk__xe_next(node, PCMK_XE_NODE)) {
 
        pair = pcmk__assert_alloc(1, sizeof(pcmk__attrd_query_pair_t));
 
        pair->node = crm_element_value(node, PCMK__XA_ATTR_HOST);
        pair->name = name;
        pair->value = crm_element_value(node, PCMK__XA_ATTR_VALUE);
        data->data.pairs = g_list_prepend(data->data.pairs, pair);
    }
}
 
static bool
reply_expected(pcmk_ipc_api_t *api, const xmlNode *request)
{
    const char *command = crm_element_value(request, PCMK_XA_TASK);
 
    return pcmk__str_any_of(command,
                            PCMK__ATTRD_CMD_CLEAR_FAILURE,
                            PCMK__ATTRD_CMD_QUERY,
                            PCMK__ATTRD_CMD_REFRESH,
                            PCMK__ATTRD_CMD_UPDATE,
                            PCMK__ATTRD_CMD_UPDATE_BOTH,
                            PCMK__ATTRD_CMD_UPDATE_DELAY,
                            NULL);
}
 
static bool
dispatch(pcmk_ipc_api_t *api, xmlNode *reply)
{
    const char *value = NULL;
    crm_exit_t status = CRM_EX_OK;
 
    pcmk__attrd_api_reply_t reply_data = {
        pcmk__attrd_reply_unknown
    };
 
    if (pcmk__xe_is(reply, PCMK__XE_ACK)) {
        return false;
    }
 
    /* Do some basic validation of the reply */
    value = crm_element_value(reply, PCMK__XA_T);
    if (pcmk__str_empty(value)
        || !pcmk__str_eq(value, PCMK__VALUE_ATTRD, pcmk__str_none)) {
        crm_info("Unrecognizable message from attribute manager: "
                 "message type '%s' not '" PCMK__VALUE_ATTRD "'",
                 pcmk__s(value, ""));
        status = CRM_EX_PROTOCOL;
        goto done;
    }
 
    value = crm_element_value(reply, PCMK__XA_SUBT);
 
    /* Only the query command gets a reply for now. NULL counts as query for
     * backward compatibility with attribute managers <2.1.3 that didn't set it.
     */
    if (pcmk__str_eq(value, PCMK__ATTRD_CMD_QUERY, pcmk__str_null_matches)) {
        if (!xmlHasProp(reply, (const xmlChar *) PCMK__XA_ATTR_NAME)) {
            status = ENXIO; // Most likely, the attribute doesn't exist
            goto done;
        }
        reply_data.reply_type = pcmk__attrd_reply_query;
        set_pairs_data(&reply_data, reply);
 
    } else {
        crm_info("Unrecognizable message from attribute manager: "
                 "message subtype '%s' unknown", pcmk__s(value, ""));
        status = CRM_EX_PROTOCOL;
        goto done;
    }
 
done:
    pcmk__call_ipc_callback(api, pcmk_ipc_event_reply, status, &reply_data);
 
    /* Free any reply data that was allocated */
    if (reply_data.data.pairs) {
        g_list_free_full(reply_data.data.pairs, free);
    }
 
    return false;
}
 
pcmk__ipc_methods_t *
pcmk__attrd_api_methods(void)
{
    pcmk__ipc_methods_t *cmds = calloc(1, sizeof(pcmk__ipc_methods_t));
 
    if (cmds != NULL) {
        cmds->new_data = NULL;
        cmds->free_data = NULL;
        cmds->post_connect = NULL;
        cmds->reply_expected = reply_expected;
        cmds->dispatch = dispatch;
    }
    return cmds;
}
 
static xmlNode *
create_attrd_op(const char *user_name)
{
    xmlNode *attrd_op = pcmk__xe_create(NULL, __func__);
 
    crm_xml_add(attrd_op, PCMK__XA_T, PCMK__VALUE_ATTRD);
    crm_xml_add(attrd_op, PCMK__XA_SRC, pcmk__s(crm_system_name, "unknown"));
    crm_xml_add(attrd_op, PCMK__XA_ATTR_USER, user_name);
 
    return attrd_op;
}
 
static int
connect_and_send_attrd_request(pcmk_ipc_api_t *api, const xmlNode *request)
{
    static const int max_retries = 5;
    int remaining_attempts = max_retries;
    int rc = pcmk_rc_ok;
    bool created_api = false;
    enum pcmk_ipc_dispatch dispatch = pcmk_ipc_dispatch_sync;
 
    if (api == NULL) {
        rc = pcmk_new_ipc_api(&api, pcmk_ipc_attrd);
        if (rc != pcmk_rc_ok) {
            return rc;
        }
        created_api = true;
    } else {
        dispatch = api->dispatch_type;
    }
 
    // If attrd is killed and is being restarted we will temporarily get
    // ECONNREFUSED on connect if it is already dead or ENOTCONN if it died
    // after we connected to it. We should wait a bit and retry in those cases.
    do {
        if (rc == ENOTCONN || rc == ECONNREFUSED) {
            sleep(max_retries - remaining_attempts);
        }
        rc = pcmk__connect_ipc(api, dispatch, remaining_attempts);
        if (rc == pcmk_rc_ok) {
            rc = pcmk__send_ipc_request(api, request);
        }
        remaining_attempts--;
    } while ((rc == ENOTCONN || rc == ECONNREFUSED) && remaining_attempts >= 0);
 
    if (created_api) {
        pcmk_free_ipc_api(api);
    }
    return rc;
}
 
int
pcmk__attrd_api_clear_failures(pcmk_ipc_api_t *api, const char *node,
                               const char *resource, const char *operation,
                               const char *interval_spec, const char *user_name,
                               uint32_t options)
{
    int rc = pcmk_rc_ok;
    xmlNode *request = create_attrd_op(user_name);
    const char *interval_desc = NULL;
    const char *op_desc = NULL;
    const char *target = pcmk__node_attr_target(node);
 
    if (target != NULL) {
        node = target;
    }
 
    if (operation) {
        interval_desc = pcmk__s(interval_spec, "nonrecurring");
        op_desc = operation;
    } else {
        interval_desc = "all";
        op_desc = "operations";
    }
    crm_debug("Asking %s to clear failure of %s %s for %s on %s",
              pcmk_ipc_name(api, true), interval_desc, op_desc,
              pcmk__s(resource, "all resources"), pcmk__s(node, "all nodes"));
 
    crm_xml_add(request, PCMK_XA_TASK, PCMK__ATTRD_CMD_CLEAR_FAILURE);
    crm_xml_add(request, PCMK__XA_ATTR_HOST, node);
    crm_xml_add(request, PCMK__XA_ATTR_RESOURCE, resource);
    crm_xml_add(request, PCMK__XA_ATTR_CLEAR_OPERATION, operation);
    crm_xml_add(request, PCMK__XA_ATTR_CLEAR_INTERVAL, interval_spec);
    crm_xml_add_int(request, PCMK__XA_ATTR_IS_REMOTE,
                    pcmk_is_set(options, pcmk__node_attr_remote));
 
    rc = connect_and_send_attrd_request(api, request);
 
    pcmk__xml_free(request);
    return rc;
}
 
int
pcmk__attrd_api_delete(pcmk_ipc_api_t *api, const char *node, const char *name,
                       uint32_t options)
{
    const char *target = NULL;
 
    if (name == NULL) {
        return EINVAL;
    }
 
    target = pcmk__node_attr_target(node);
 
    if (target != NULL) {
        node = target;
    }
 
    /* Make sure the right update option is set. */
    options &= ~pcmk__node_attr_delay;
    options |= pcmk__node_attr_value;
 
    return pcmk__attrd_api_update(api, node, name, NULL, NULL, NULL, NULL, options);
}
 
int
pcmk__attrd_api_purge(pcmk_ipc_api_t *api, const char *node, bool reap)
{
    int rc = pcmk_rc_ok;
    xmlNode *request = NULL;
    const char *target = pcmk__node_attr_target(node);
 
    if (target != NULL) {
        node = target;
    }
 
    crm_debug("Asking %s to purge transient attributes%s for %s",
              pcmk_ipc_name(api, true),
              (reap? " and node cache entries" : ""),
              pcmk__s(node, "local node"));
 
    request = create_attrd_op(NULL);
 
    crm_xml_add(request, PCMK_XA_TASK, PCMK__ATTRD_CMD_PEER_REMOVE);
    pcmk__xe_set_bool_attr(request, PCMK__XA_REAP, reap);
    crm_xml_add(request, PCMK__XA_ATTR_HOST, node);
 
    rc = connect_and_send_attrd_request(api, request);
 
    pcmk__xml_free(request);
    return rc;
}
 
int
pcmk__attrd_api_query(pcmk_ipc_api_t *api, const char *node, const char *name,
                      uint32_t options)
{
    int rc = pcmk_rc_ok;
    xmlNode *request = NULL;
    const char *target = NULL;
 
    if (name == NULL) {
        return EINVAL;
    }
 
    if (pcmk_is_set(options, pcmk__node_attr_query_all)) {
        node = NULL;
    } else {
        target = pcmk__node_attr_target(node);
 
        if (target != NULL) {
            node = target;
        } else if (node == NULL) {
            node = "localhost";
        }
    }
 
    crm_debug("Querying %s for value of '%s'%s%s",
              pcmk_ipc_name(api, true), name,
              ((node == NULL)? "" : " on "), pcmk__s(node, ""));
 
    request = create_attrd_op(NULL);
 
    crm_xml_add(request, PCMK__XA_ATTR_NAME, name);
    crm_xml_add(request, PCMK_XA_TASK, PCMK__ATTRD_CMD_QUERY);
    crm_xml_add(request, PCMK__XA_ATTR_HOST, node);
 
    rc = connect_and_send_attrd_request(api, request);
    pcmk__xml_free(request);
    return rc;
}
 
int
pcmk__attrd_api_refresh(pcmk_ipc_api_t *api, const char *node)
{
    int rc = pcmk_rc_ok;
    xmlNode *request = NULL;
    const char *target = pcmk__node_attr_target(node);
 
    if (target != NULL) {
        node = target;
    }
 
    crm_debug("Asking %s to write all transient attributes for %s to CIB",
              pcmk_ipc_name(api, true), pcmk__s(node, "local node"));
 
    request = create_attrd_op(NULL);
 
    crm_xml_add(request, PCMK_XA_TASK, PCMK__ATTRD_CMD_REFRESH);
    crm_xml_add(request, PCMK__XA_ATTR_HOST, node);
 
    rc = connect_and_send_attrd_request(api, request);
 
    pcmk__xml_free(request);
    return rc;
}
 
static void
add_op_attr(xmlNode *op, uint32_t options)
{
    if (pcmk_all_flags_set(options, pcmk__node_attr_value | pcmk__node_attr_delay)) {
        crm_xml_add(op, PCMK_XA_TASK, PCMK__ATTRD_CMD_UPDATE_BOTH);
    } else if (pcmk_is_set(options, pcmk__node_attr_value)) {
        crm_xml_add(op, PCMK_XA_TASK, PCMK__ATTRD_CMD_UPDATE);
    } else if (pcmk_is_set(options, pcmk__node_attr_delay)) {
        crm_xml_add(op, PCMK_XA_TASK, PCMK__ATTRD_CMD_UPDATE_DELAY);
    }
}
 
static void
populate_update_op(xmlNode *op, const char *node, const char *name, const char *value,
                   const char *dampen, const char *set, uint32_t options)
{
    if (pcmk_is_set(options, pcmk__node_attr_pattern)) {
        crm_xml_add(op, PCMK__XA_ATTR_REGEX, name);
    } else {
        crm_xml_add(op, PCMK__XA_ATTR_NAME, name);
    }
 
    if (pcmk_is_set(options, pcmk__node_attr_utilization)) {
        crm_xml_add(op, PCMK__XA_ATTR_SET_TYPE, PCMK_XE_UTILIZATION);
    } else {
        crm_xml_add(op, PCMK__XA_ATTR_SET_TYPE, PCMK_XE_INSTANCE_ATTRIBUTES);
    }
 
    add_op_attr(op, options);
 
    crm_xml_add(op, PCMK__XA_ATTR_VALUE, value);
    crm_xml_add(op, PCMK__XA_ATTR_DAMPENING, dampen);
    crm_xml_add(op, PCMK__XA_ATTR_HOST, node);
    crm_xml_add(op, PCMK__XA_ATTR_SET, set);
    crm_xml_add_int(op, PCMK__XA_ATTR_IS_REMOTE,
                    pcmk_is_set(options, pcmk__node_attr_remote));
    crm_xml_add_int(op, PCMK__XA_ATTR_IS_PRIVATE,
                    pcmk_is_set(options, pcmk__node_attr_private));
 
    if (pcmk_is_set(options, pcmk__node_attr_sync_local)) {
        crm_xml_add(op, PCMK__XA_ATTR_SYNC_POINT, PCMK__VALUE_LOCAL);
    } else if (pcmk_is_set(options, pcmk__node_attr_sync_cluster)) {
        crm_xml_add(op, PCMK__XA_ATTR_SYNC_POINT, PCMK__VALUE_CLUSTER);
    }
}
 
int
pcmk__attrd_api_update(pcmk_ipc_api_t *api, const char *node, const char *name,
                       const char *value, const char *dampen, const char *set,
                       const char *user_name, uint32_t options)
{
    int rc = pcmk_rc_ok;
    xmlNode *request = NULL;
    const char *target = NULL;
 
    if (name == NULL) {
        return EINVAL;
    }
 
    target = pcmk__node_attr_target(node);
 
    if (target != NULL) {
        node = target;
    }
 
    crm_debug("Asking %s to update '%s' to '%s' for %s",
              pcmk_ipc_name(api, true), name, pcmk__s(value, "(null)"),
              pcmk__s(node, "local node"));
 
    request = create_attrd_op(user_name);
    populate_update_op(request, node, name, value, dampen, set, options);
 
    rc = connect_and_send_attrd_request(api, request);
 
    pcmk__xml_free(request);
    return rc;
}
 
int
pcmk__attrd_api_update_list(pcmk_ipc_api_t *api, GList *attrs, const char *dampen,
                            const char *set, const char *user_name,
                            uint32_t options)
{
    int rc = pcmk_rc_ok;
    xmlNode *request = NULL;
 
    if (attrs == NULL) {
        return EINVAL;
    }
 
    /* There are two different ways of handling a list of attributes:
     *
     * (1) For messages originating from some command line tool, we have to send
     *     them one at a time.  In this loop, we just call pcmk__attrd_api_update
     *     for each, letting it deal with creating the API object if it doesn't
     *     already exist.
     *
     *     The reason we can't use a single message in this case is that we can't
     *     trust that the server supports it.  Remote nodes could be involved
     *     here, and there's no guarantee that a newer client running on a remote
     *     node is talking to (or proxied through) a cluster node with a newer
     *     attrd.  We also can't just try sending a single message and then falling
     *     back on multiple.  There's no handshake with the attrd server to
     *     determine its version.  And then we would need to do that fallback in the
     *     dispatch function for this to work for all connection types (mainloop in
     *     particular), and at that point we won't know what the original message
     *     was in order to break it apart and resend as individual messages.
     *
     * (2) For messages between daemons, we can be assured that the local attrd
     *     will support the new message and that it can send to the other attrds
     *     as one request or split up according to the minimum supported version.
     */
    for (GList *iter = attrs; iter != NULL; iter = iter->next) {
        pcmk__attrd_query_pair_t *pair = (pcmk__attrd_query_pair_t *) iter->data;
 
        if (pcmk__is_daemon) {
            const char *target = NULL;
            xmlNode *child = NULL;
 
            /* First time through this loop - create the basic request. */
            if (request == NULL) {
                request = create_attrd_op(user_name);
                add_op_attr(request, options);
            }
 
            /* Add a child node for this operation.  We add the task to the top
             * level XML node so attrd_ipc_dispatch doesn't need changes.  And
             * then we also add the task to each child node in populate_update_op
             * so attrd_client_update knows what form of update is taking place.
             */
            child = pcmk__xe_create(request, PCMK_XE_OP);
            target = pcmk__node_attr_target(pair->node);
 
            if (target != NULL) {
                pair->node = target;
            }
 
            populate_update_op(child, pair->node, pair->name, pair->value, dampen,
                               set, options);
        } else {
            rc = pcmk__attrd_api_update(api, pair->node, pair->name, pair->value,
                                        dampen, set, user_name, options);
        }
    }
 
    /* If we were doing multiple attributes at once, we still need to send the
     * request.  Do that now, creating and destroying the API object if needed.
     */
    if (pcmk__is_daemon) {
        rc = connect_and_send_attrd_request(api, request);
        pcmk__xml_free(request);
    }
 
    return rc;
}