attrd_corosync.c
No OneTemporary
Actions

Size

20 KB

Referenced Files

None

Subscribers

None

attrd_corosync.c
View Options

	/*
	* Copyright 2013-2024 the Pacemaker project contributors
	*
	* The version control history for this file may have further details.
	*
	* This source code is licensed under the GNU General Public License version 2
	* or later (GPLv2+) WITHOUT ANY WARRANTY.
	*/

	#include <crm_internal.h>

	#include <errno.h>
	#include <stdbool.h>
	#include <stdint.h>
	#include <stdlib.h>

	#include <crm/cluster.h>
	#include <crm/cluster/internal.h>
	#include <crm/common/logging.h>
	#include <crm/common/results.h>
	#include <crm/common/strings_internal.h>
	#include <crm/common/xml.h>

	#include "pacemaker-attrd.h"

	static xmlNode *
	attrd_confirmation(int callid)
	{
	xmlNode *node = pcmk__xe_create(NULL, __func__);

	crm_xml_add(node, PCMK__XA_T, PCMK__VALUE_ATTRD);
	crm_xml_add(node, PCMK__XA_SRC, pcmk__cluster_local_node_name());
	crm_xml_add(node, PCMK_XA_TASK, PCMK__ATTRD_CMD_CONFIRM);
	crm_xml_add_int(node, PCMK__XA_CALL_ID, callid);

	return node;
	}

	static void
	attrd_peer_message(pcmk__node_status_t peer, xmlNode xml)
	{
	const char *election_op = crm_element_value(xml, PCMK__XA_CRM_TASK);

	if (election_op) {
	attrd_handle_election_op(peer, xml);
	return;
	}

	if (attrd_shutting_down(false)) {
	/* If we're shutting down, we want to continue responding to election
	* ops as long as we're a cluster member (because our vote may be
	* needed). Ignore all other messages.
	*/
	return;

	} else {
	pcmk__request_t request = {
	.ipc_client = NULL,
	.ipc_id = 0,
	.ipc_flags = 0,
	.peer = peer->name,
	.xml = xml,
	.call_options = 0,
	.result = PCMK__UNKNOWN_RESULT,
	};

	request.op = crm_element_value_copy(request.xml, PCMK_XA_TASK);
	CRM_CHECK(request.op != NULL, return);

	attrd_handle_request(&request);

	/* Having finished handling the request, check to see if the originating
	* peer requested confirmation. If so, send that confirmation back now.
	*/
	if (pcmk__xe_attr_is_true(xml, PCMK__XA_CONFIRM) &&
	!pcmk__str_eq(request.op, PCMK__ATTRD_CMD_CONFIRM, pcmk__str_none)) {
	int callid = 0;
	xmlNode *reply = NULL;

	/* Add the confirmation ID for the message we are confirming to the
	* response so the originating peer knows what they're a confirmation
	* for.
	*/
	crm_element_value_int(xml, PCMK__XA_CALL_ID, &callid);
	reply = attrd_confirmation(callid);

	/* And then send the confirmation back to the originating peer. This
	* ends up right back in this same function (attrd_peer_message) on the
	* peer where it will have to do something with a PCMK__XA_CONFIRM type
	* message.
	*/
	crm_debug("Sending %s a confirmation", peer->name);
	attrd_send_message(peer, reply, false);
	pcmk__xml_free(reply);
	}

	pcmk__reset_request(&request);
	}
	}

	static void
	attrd_cpg_dispatch(cpg_handle_t handle,
	const struct cpg_name *groupName,
	uint32_t nodeid, uint32_t pid, void *msg, size_t msg_len)
	{
	xmlNode *xml = NULL;
	const char *from = NULL;
	char *data = pcmk__cpg_message_data(handle, nodeid, pid, msg, &from);

	if(data == NULL) {
	return;
	}

	xml = pcmk__xml_parse(data);

	if (xml == NULL) {
	crm_err("Bad message received from %s[%u]: '%.120s'",
	from, nodeid, data);
	} else {
	attrd_peer_message(pcmk__get_node(nodeid, from, NULL,
	pcmk__node_search_cluster_member),
	xml);
	}

	pcmk__xml_free(xml);
	free(data);
	}

	static void
	attrd_cpg_destroy(gpointer unused)
	{
	if (attrd_shutting_down(false)) {
	crm_info("Disconnected from Corosync process group");

	} else {
	crm_crit("Lost connection to Corosync process group, shutting down");
	attrd_exit_status = CRM_EX_DISCONNECT;
	attrd_shutdown(0);
	}
	}

	/*!
	* \internal
	* \brief Broadcast an update for a single attribute value
	*
	* \param[in] a Attribute to broadcast
	* \param[in] v Attribute value to broadcast
	*/
	void
	attrd_broadcast_value(const attribute_t a, const attribute_value_t v)
	{
	xmlNode *op = pcmk__xe_create(NULL, PCMK_XE_OP);

	crm_xml_add(op, PCMK_XA_TASK, PCMK__ATTRD_CMD_UPDATE);
	attrd_add_value_xml(op, a, v, false);
	attrd_send_message(NULL, op, false);
	pcmk__xml_free(op);
	}

	#define state_text(state) pcmk__s((state), "in unknown state")

	static void
	attrd_peer_change_cb(enum pcmk__node_update kind, pcmk__node_status_t *peer,
	const void *data)
	{
	bool gone = false;
	bool is_remote = pcmk_is_set(peer->flags, pcmk__node_status_remote);

	switch (kind) {
	case pcmk__node_update_name:
	crm_debug("%s node %s is now %s",
	(is_remote? "Remote" : "Cluster"),
	peer->name, state_text(peer->state));
	break;

	case pcmk__node_update_processes:
	if (!pcmk_is_set(peer->processes, crm_get_cluster_proc())) {
	gone = true;
	}
	crm_debug("Node %s is %s a peer",
	peer->name, (gone? "no longer" : "now"));
	break;

	case pcmk__node_update_state:
	crm_debug("%s node %s is now %s (was %s)",
	(is_remote? "Remote" : "Cluster"),
	peer->name, state_text(peer->state), state_text(data));
	if (pcmk__str_eq(peer->state, PCMK_VALUE_MEMBER, pcmk__str_none)) {
	/* If we're the writer, send new peers a list of all attributes
	* (unless it's a remote node, which doesn't run its own attrd)
	*/
	if (attrd_election_won()
	&& !pcmk_is_set(peer->flags, pcmk__node_status_remote)) {
	attrd_peer_sync(peer);
	}
	} else {
	// Remove all attribute values associated with lost nodes
	attrd_peer_remove(peer->name, false, "loss");
	gone = true;
	}
	break;
	}

	// Remove votes from cluster nodes that leave, in case election in progress
	if (gone && !is_remote) {
	attrd_remove_voter(peer);
	attrd_remove_peer_protocol_ver(peer->name);
	attrd_do_not_expect_from_peer(peer->name);
	}
	}

	#define readable_value(rv_v) pcmk__s((rv_v)->current, "(unset)")

	#define readable_peer(p) \
	(((p) == NULL)? "all peers" : pcmk__s((p)->name, "unknown peer"))

	static void
	update_attr_on_host(attribute_t a, const pcmk__node_status_t peer,
	const xmlNode xml, const char attr, const char *value,
	const char *host, bool filter)
	{
	int is_remote = 0;
	bool changed = false;
	attribute_value_t *v = NULL;
	const char *prev_xml_id = NULL;
	const char *node_xml_id = crm_element_value(xml, PCMK__XA_ATTR_HOST_ID);

	// Create entry for value if not already existing
	v = g_hash_table_lookup(a->values, host);
	if (v == NULL) {
	v = pcmk__assert_alloc(1, sizeof(attribute_value_t));

	v->nodename = pcmk__str_copy(host);
	g_hash_table_replace(a->values, v->nodename, v);
	}

	/* If update doesn't contain the node XML ID, fall back to any previously
	* known value (for logging)
	*/
	prev_xml_id = attrd_get_node_xml_id(v->nodename);
	if (node_xml_id == NULL) {
	node_xml_id = prev_xml_id;
	}

	// If value is for a Pacemaker Remote node, remember that
	crm_element_value_int(xml, PCMK__XA_ATTR_IS_REMOTE, &is_remote);
	if (is_remote) {
	attrd_set_value_flags(v, attrd_value_remote);
	pcmk__assert(pcmk__cluster_lookup_remote_node(host) != NULL);
	}

	// Check whether the value changed
	changed = !pcmk__str_eq(v->current, value, pcmk__str_casei);

	if (changed && filter
	&& pcmk__str_eq(host, attrd_cluster->priv->node_name,
	pcmk__str_casei)) {
	/* Broadcast the local value for an attribute that differs from the
	* value provided in a peer's attribute synchronization response. This
	* ensures a node's values for itself take precedence and all peers are
	* kept in sync.
	*/
	v = g_hash_table_lookup(a->values, attrd_cluster->priv->node_name);
	crm_notice("%s[%s]: local value '%s' takes priority over '%s' from %s",
	attr, host, readable_value(v), value, peer->name);
	attrd_broadcast_value(a, v);

	} else if (changed) {
	crm_notice("Setting %s[%s]%s%s: %s -> %s "
	QB_XS " from %s with %s write delay and node XML ID %s",
	attr, host, a->set_type ? " in " : "",
	pcmk__s(a->set_type, ""), readable_value(v),
	pcmk__s(value, "(unset)"), peer->name,
	(a->timeout_ms == 0)? "no" : pcmk__readable_interval(a->timeout_ms),
	pcmk__s(node_xml_id, "unknown"));
	pcmk__str_update(&v->current, value);
	attrd_set_attr_flags(a, attrd_attr_changed);

	if (pcmk__str_eq(host, attrd_cluster->priv->node_name, pcmk__str_casei)
	&& pcmk__str_eq(attr, PCMK__NODE_ATTR_SHUTDOWN, pcmk__str_none)) {

	if (!pcmk__str_eq(value, "0", pcmk__str_null_matches)) {
	attrd_set_requesting_shutdown();

	} else {
	attrd_clear_requesting_shutdown();
	}
	}

	// Write out new value or start dampening timer
	if (a->timeout_ms && a->timer) {
	crm_trace("Delaying write of %s %s for dampening",
	attr, pcmk__readable_interval(a->timeout_ms));
	mainloop_timer_start(a->timer);
	} else {
	attrd_write_or_elect_attribute(a);
	}

	} else {
	int is_force_write = 0;

	crm_element_value_int(xml, PCMK__XA_ATTRD_IS_FORCE_WRITE,
	&is_force_write);

	if (is_force_write == 1 && a->timeout_ms && a->timer) {
	/* Save forced writing and set change flag. */
	/* The actual attribute is written by Writer after election. */
	crm_trace("%s[%s] from %s is unchanged (%s), forcing write",
	attr, host, peer->name, pcmk__s(value, "unset"));
	attrd_set_attr_flags(a, attrd_attr_force_write);
	} else {
	crm_trace("%s[%s] from %s is unchanged (%s)",
	attr, host, peer->name, pcmk__s(value, "unset"));
	}
	}

	// This allows us to later detect local values that peer doesn't know about
	attrd_set_value_flags(v, attrd_value_from_peer);

	// Remember node's XML ID if we're just learning it
	if ((node_xml_id != NULL)
	&& !pcmk__str_eq(node_xml_id, prev_xml_id, pcmk__str_none)) {
	crm_trace("Learned %s[%s] node XML ID is %s (was %s)",
	a->id, v->nodename, node_xml_id,
	pcmk__s(prev_xml_id, "unknown"));
	attrd_set_node_xml_id(v->nodename, node_xml_id);
	if (attrd_election_won()) {
	// In case we couldn't write a value missing the XML ID before
	attrd_write_attributes(attrd_write_changed);
	}
	}
	}

	static void
	attrd_peer_update_one(const pcmk__node_status_t peer, xmlNode xml,
	bool filter)
	{
	attribute_t *a = NULL;
	const char *attr = crm_element_value(xml, PCMK__XA_ATTR_NAME);
	const char *value = crm_element_value(xml, PCMK__XA_ATTR_VALUE);
	const char *host = crm_element_value(xml, PCMK__XA_ATTR_HOST);

	if (attr == NULL) {
	crm_warn("Could not update attribute: peer did not specify name");
	return;
	}

	a = attrd_populate_attribute(xml, attr);
	if (a == NULL) {
	return;
	}

	if (host == NULL) {
	// If no host was specified, update all hosts
	GHashTableIter vIter;

	crm_debug("Setting %s for all hosts to %s", attr, value);
	pcmk__xe_remove_attr(xml, PCMK__XA_ATTR_HOST_ID);
	g_hash_table_iter_init(&vIter, a->values);

	while (g_hash_table_iter_next(&vIter, (gpointer *) & host, NULL)) {
	update_attr_on_host(a, peer, xml, attr, value, host, filter);
	}

	} else {
	// Update attribute value for the given host
	update_attr_on_host(a, peer, xml, attr, value, host, filter);
	}

	/* If this is a message from some attrd instance broadcasting its protocol
	* version, check to see if it's a new minimum version.
	*/
	if (pcmk__str_eq(attr, CRM_ATTR_PROTOCOL, pcmk__str_none)) {
	attrd_update_minimum_protocol_ver(peer->name, value);
	}
	}

	static void
	broadcast_unseen_local_values(void)
	{
	GHashTableIter aIter;
	GHashTableIter vIter;
	attribute_t *a = NULL;
	attribute_value_t *v = NULL;
	xmlNode *sync = NULL;

	g_hash_table_iter_init(&aIter, attributes);
	while (g_hash_table_iter_next(&aIter, NULL, (gpointer *) & a)) {

	g_hash_table_iter_init(&vIter, a->values);
	while (g_hash_table_iter_next(&vIter, NULL, (gpointer *) & v)) {

	if (!pcmk_is_set(v->flags, attrd_value_from_peer)
	&& pcmk__str_eq(v->nodename, attrd_cluster->priv->node_name,
	pcmk__str_casei)) {
	crm_trace("* %s[%s]='%s' is local-only",
	a->id, v->nodename, readable_value(v));
	if (sync == NULL) {
	sync = pcmk__xe_create(NULL, __func__);
	crm_xml_add(sync, PCMK_XA_TASK, PCMK__ATTRD_CMD_SYNC_RESPONSE);
	}
	attrd_add_value_xml(sync, a, v, a->timeout_ms && a->timer);
	}
	}
	}

	if (sync != NULL) {
	crm_debug("Broadcasting local-only values");
	attrd_send_message(NULL, sync, false);
	pcmk__xml_free(sync);
	}
	}

	int
	attrd_cluster_connect(void)
	{
	int rc = pcmk_rc_ok;

	attrd_cluster = pcmk_cluster_new();

	pcmk_cluster_set_destroy_fn(attrd_cluster, attrd_cpg_destroy);
	pcmk_cpg_set_deliver_fn(attrd_cluster, attrd_cpg_dispatch);
	pcmk_cpg_set_confchg_fn(attrd_cluster, pcmk__cpg_confchg_cb);

	pcmk__cluster_set_status_callback(&attrd_peer_change_cb);

	rc = pcmk_cluster_connect(attrd_cluster);
	rc = pcmk_rc2legacy(rc);
	if (rc != pcmk_ok) {
	crm_err("Cluster connection failed");
	return rc;
	}
	return pcmk_ok;
	}

	void
	attrd_peer_clear_failure(pcmk__request_t *request)
	{
	xmlNode *xml = request->xml;
	const char *rsc = crm_element_value(xml, PCMK__XA_ATTR_RESOURCE);
	const char *host = crm_element_value(xml, PCMK__XA_ATTR_HOST);
	const char *op = crm_element_value(xml, PCMK__XA_ATTR_CLEAR_OPERATION);
	const char *interval_spec = crm_element_value(xml,
	PCMK__XA_ATTR_CLEAR_INTERVAL);
	guint interval_ms = 0U;
	char *attr = NULL;
	GHashTableIter iter;
	regex_t regex;

	pcmk__node_status_t *peer =
	pcmk__get_node(0, request->peer, NULL,
	pcmk__node_search_cluster_member);

	pcmk_parse_interval_spec(interval_spec, &interval_ms);

	if (attrd_failure_regex(&regex, rsc, op, interval_ms) != pcmk_ok) {
	crm_info("Ignoring invalid request to clear failures for %s",
	pcmk__s(rsc, "all resources"));
	return;
	}

	crm_xml_add(xml, PCMK_XA_TASK, PCMK__ATTRD_CMD_UPDATE);

	/* Make sure value is not set, so we delete */
	pcmk__xe_remove_attr(xml, PCMK__XA_ATTR_VALUE);

	g_hash_table_iter_init(&iter, attributes);
	while (g_hash_table_iter_next(&iter, (gpointer *) &attr, NULL)) {
	if (regexec(&regex, attr, 0, NULL, 0) == 0) {
	crm_trace("Matched %s when clearing %s",
	attr, pcmk__s(rsc, "all resources"));
	crm_xml_add(xml, PCMK__XA_ATTR_NAME, attr);
	attrd_peer_update(peer, xml, host, false);
	}
	}
	regfree(&regex);
	}

	/*!
	* \internal
	* \brief Load attributes from a peer sync response
	*
	* \param[in] peer Peer that sent sync response
	* \param[in] peer_won Whether peer is the attribute writer
	* \param[in,out] xml Request XML
	*/
	void
	attrd_peer_sync_response(const pcmk__node_status_t *peer, bool peer_won,
	xmlNode *xml)
	{
	crm_info("Processing " PCMK__ATTRD_CMD_SYNC_RESPONSE " from %s",
	peer->name);

	if (peer_won) {
	/* Initialize the "seen" flag for all attributes to cleared, so we can
	* detect attributes that local node has but the writer doesn't.
	*/
	attrd_clear_value_seen();
	}

	// Process each attribute update in the sync response
	for (xmlNode *child = pcmk__xe_first_child(xml, NULL, NULL, NULL);
	child != NULL; child = pcmk__xe_next(child, NULL)) {

	attrd_peer_update(peer, child,
	crm_element_value(child, PCMK__XA_ATTR_HOST), true);
	}

	if (peer_won) {
	/* If any attributes are still not marked as seen, the writer doesn't
	* know about them, so send all peers an update with them.
	*/
	broadcast_unseen_local_values();
	}
	}

	/*!
	* \internal
	* \brief Remove all attributes and optionally peer cache entries for a node
	*
	* \param[in] host Name of node to purge
	* \param[in] uncache If true, remove node from peer caches
	* \param[in] source Who requested removal (only used for logging)
	*/
	void
	attrd_peer_remove(const char host, bool uncache, const char source)
	{
	attribute_t *a = NULL;
	GHashTableIter aIter;

	CRM_CHECK(host != NULL, return);
	crm_notice("Removing all %s attributes for node %s "
	QB_XS " %s reaping node from cache",
	host, source, (uncache? "and" : "without"));

	g_hash_table_iter_init(&aIter, attributes);
	while (g_hash_table_iter_next(&aIter, NULL, (gpointer *) & a)) {
	if(g_hash_table_remove(a->values, host)) {
	crm_debug("Removed %s[%s] for peer %s", a->id, host, source);
	}
	}

	if (uncache) {
	pcmk__purge_node_from_cache(host, 0);
	attrd_forget_node_xml_id(host);
	}
	}

	/*!
	* \internal
	* \brief Send all known attributes and values to a peer
	*
	* \param[in] peer Peer to send sync to (if NULL, broadcast to all peers)
	*/
	void
	attrd_peer_sync(pcmk__node_status_t *peer)
	{
	GHashTableIter aIter;
	GHashTableIter vIter;

	attribute_t *a = NULL;
	attribute_value_t *v = NULL;
	xmlNode *sync = pcmk__xe_create(NULL, __func__);

	crm_xml_add(sync, PCMK_XA_TASK, PCMK__ATTRD_CMD_SYNC_RESPONSE);

	g_hash_table_iter_init(&aIter, attributes);
	while (g_hash_table_iter_next(&aIter, NULL, (gpointer *) & a)) {
	g_hash_table_iter_init(&vIter, a->values);
	while (g_hash_table_iter_next(&vIter, NULL, (gpointer *) & v)) {
	crm_debug("Syncing %s[%s]='%s' to %s",
	a->id, v->nodename, readable_value(v),
	readable_peer(peer));
	attrd_add_value_xml(sync, a, v, false);
	}
	}

	crm_debug("Syncing values to %s", readable_peer(peer));
	attrd_send_message(peer, sync, false);
	pcmk__xml_free(sync);
	}

	void
	attrd_peer_update(const pcmk__node_status_t peer, xmlNode xml,
	const char *host, bool filter)
	{
	bool handle_sync_point = false;

	CRM_CHECK((peer != NULL) && (xml != NULL), return);
	if (xml->children != NULL) {
	for (xmlNode *child = pcmk__xe_first_child(xml, PCMK_XE_OP, NULL, NULL);
	child != NULL; child = pcmk__xe_next(child, PCMK_XE_OP)) {

	pcmk__xe_copy_attrs(child, xml, pcmk__xaf_no_overwrite);
	attrd_peer_update_one(peer, child, filter);

	if (attrd_request_has_sync_point(child)) {
	handle_sync_point = true;
	}
	}

	} else {
	attrd_peer_update_one(peer, xml, filter);

	if (attrd_request_has_sync_point(xml)) {
	handle_sync_point = true;
	}
	}

	/* If the update XML specified that the client wanted to wait for a sync
	* point, process that now.
	*/
	if (handle_sync_point) {
	crm_trace("Hit local sync point for attribute update");
	attrd_ack_waitlist_clients(attrd_sync_point_local, xml);
	}
	}

File Metadata

Mime Type: text/x-c
Expires: Thu, Jun 26, 8:15 PM (19 h, 16 m)
Storage Engine: blob
Storage Format: Raw Data
Storage Handle: 1953851
Default Alt Text: attrd_corosync.c (20 KB)

attrd_corosync.cNo OneTemporaryActions

attrd_corosync.cView Options

File Metadata

Event Timeline

attrd_corosync.c
No OneTemporary
Actions

attrd_corosync.c
View Options