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Diffstat (limited to 'lib/common/messages.c')
| -rw-r--r-- | lib/common/messages.c | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/lib/common/messages.c b/lib/common/messages.c new file mode 100644 index 0000000..2c01eed --- /dev/null +++ b/lib/common/messages.c @@ -0,0 +1,291 @@ +/* + * Copyright 2004-2022 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 <sys/types.h> + +#include <glib.h> +#include <libxml/tree.h> + +#include <crm/msg_xml.h> +#include <crm/common/xml_internal.h> + +/*! + * \brief Create a Pacemaker request (for IPC or cluster layer) + * + * \param[in] task What to set as the request's task + * \param[in] msg_data What to add as the request's data contents + * \param[in] host_to What to set as the request's destination host + * \param[in] sys_to What to set as the request's destination system + * \param[in] sys_from If not NULL, set as request's origin system + * \param[in] uuid_from If not NULL, use in request's origin system + * \param[in] origin Name of function that called this one + * + * \return XML of new request + * + * \note One of sys_from or uuid_from must be non-NULL + * \note This function should not be called directly, but via the + * create_request() wrapper. + * \note The caller is responsible for freeing the result using free_xml(). + */ +xmlNode * +create_request_adv(const char *task, xmlNode *msg_data, + const char *host_to, const char *sys_to, + const char *sys_from, const char *uuid_from, + const char *origin) +{ + static uint ref_counter = 0; + + char *true_from = NULL; + xmlNode *request = NULL; + char *reference = crm_strdup_printf("%s-%s-%lld-%u", + (task? task : "_empty_"), + (sys_from? sys_from : "_empty_"), + (long long) time(NULL), ref_counter++); + + if (uuid_from != NULL) { + true_from = crm_strdup_printf("%s_%s", uuid_from, + (sys_from? sys_from : "none")); + } else if (sys_from != NULL) { + true_from = strdup(sys_from); + } else { + crm_err("Cannot create IPC request: No originating system specified"); + } + + // host_from will get set for us if necessary by the controller when routed + request = create_xml_node(NULL, __func__); + crm_xml_add(request, F_CRM_ORIGIN, origin); + crm_xml_add(request, F_TYPE, T_CRM); + crm_xml_add(request, F_CRM_VERSION, CRM_FEATURE_SET); + crm_xml_add(request, F_CRM_MSG_TYPE, XML_ATTR_REQUEST); + crm_xml_add(request, F_CRM_REFERENCE, reference); + crm_xml_add(request, F_CRM_TASK, task); + crm_xml_add(request, F_CRM_SYS_TO, sys_to); + crm_xml_add(request, F_CRM_SYS_FROM, true_from); + + /* HOSTTO will be ignored if it is to the DC anyway. */ + if (host_to != NULL && strlen(host_to) > 0) { + crm_xml_add(request, F_CRM_HOST_TO, host_to); + } + + if (msg_data != NULL) { + add_message_xml(request, F_CRM_DATA, msg_data); + } + free(reference); + free(true_from); + + return request; +} + +/*! + * \brief Create a Pacemaker reply (for IPC or cluster layer) + * + * \param[in] original_request XML of request this is a reply to + * \param[in] xml_response_data XML to copy as data section of reply + * \param[in] origin Name of function that called this one + * + * \return XML of new reply + * + * \note This function should not be called directly, but via the + * create_reply() wrapper. + * \note The caller is responsible for freeing the result using free_xml(). + */ +xmlNode * +create_reply_adv(const xmlNode *original_request, xmlNode *xml_response_data, + const char *origin) +{ + xmlNode *reply = NULL; + + const char *host_from = crm_element_value(original_request, F_CRM_HOST_FROM); + const char *sys_from = crm_element_value(original_request, F_CRM_SYS_FROM); + const char *sys_to = crm_element_value(original_request, F_CRM_SYS_TO); + const char *type = crm_element_value(original_request, F_CRM_MSG_TYPE); + const char *operation = crm_element_value(original_request, F_CRM_TASK); + const char *crm_msg_reference = crm_element_value(original_request, F_CRM_REFERENCE); + + if (type == NULL) { + crm_err("Cannot create new_message, no message type in original message"); + CRM_ASSERT(type != NULL); + return NULL; +#if 0 + } else if (strcasecmp(XML_ATTR_REQUEST, type) != 0) { + crm_err("Cannot create new_message, original message was not a request"); + return NULL; +#endif + } + reply = create_xml_node(NULL, __func__); + if (reply == NULL) { + crm_err("Cannot create new_message, malloc failed"); + return NULL; + } + + crm_xml_add(reply, F_CRM_ORIGIN, origin); + crm_xml_add(reply, F_TYPE, T_CRM); + crm_xml_add(reply, F_CRM_VERSION, CRM_FEATURE_SET); + crm_xml_add(reply, F_CRM_MSG_TYPE, XML_ATTR_RESPONSE); + crm_xml_add(reply, F_CRM_REFERENCE, crm_msg_reference); + crm_xml_add(reply, F_CRM_TASK, operation); + + /* since this is a reply, we reverse the from and to */ + crm_xml_add(reply, F_CRM_SYS_TO, sys_from); + crm_xml_add(reply, F_CRM_SYS_FROM, sys_to); + + /* HOSTTO will be ignored if it is to the DC anyway. */ + if (host_from != NULL && strlen(host_from) > 0) { + crm_xml_add(reply, F_CRM_HOST_TO, host_from); + } + + if (xml_response_data != NULL) { + add_message_xml(reply, F_CRM_DATA, xml_response_data); + } + + return reply; +} + +xmlNode * +get_message_xml(const xmlNode *msg, const char *field) +{ + return pcmk__xml_first_child(first_named_child(msg, field)); +} + +gboolean +add_message_xml(xmlNode *msg, const char *field, xmlNode *xml) +{ + xmlNode *holder = create_xml_node(msg, field); + + add_node_copy(holder, xml); + return TRUE; +} + +/*! + * \brief Get name to be used as identifier for cluster messages + * + * \param[in] name Actual system name to check + * + * \return Non-NULL cluster message identifier corresponding to name + * + * \note The Pacemaker daemons were renamed in version 2.0.0, but the old names + * must continue to be used as the identifier for cluster messages, so + * that mixed-version clusters are possible during a rolling upgrade. + */ +const char * +pcmk__message_name(const char *name) +{ + if (name == NULL) { + return "unknown"; + + } else if (!strcmp(name, "pacemaker-attrd")) { + return "attrd"; + + } else if (!strcmp(name, "pacemaker-based")) { + return CRM_SYSTEM_CIB; + + } else if (!strcmp(name, "pacemaker-controld")) { + return CRM_SYSTEM_CRMD; + + } else if (!strcmp(name, "pacemaker-execd")) { + return CRM_SYSTEM_LRMD; + + } else if (!strcmp(name, "pacemaker-fenced")) { + return "stonith-ng"; + + } else if (!strcmp(name, "pacemaker-schedulerd")) { + return CRM_SYSTEM_PENGINE; + + } else { + return name; + } +} + +/*! + * \internal + * \brief Register handlers for server commands + * + * \param[in] handlers Array of handler functions for supported server commands + * (the final entry must have a NULL command name, and if + * it has a handler it will be used as the default handler + * for unrecognized commands) + * + * \return Newly created hash table with commands and handlers + * \note The caller is responsible for freeing the return value with + * g_hash_table_destroy(). + */ +GHashTable * +pcmk__register_handlers(const pcmk__server_command_t handlers[]) +{ + GHashTable *commands = g_hash_table_new(g_str_hash, g_str_equal); + + if (handlers != NULL) { + int i; + + for (i = 0; handlers[i].command != NULL; ++i) { + g_hash_table_insert(commands, (gpointer) handlers[i].command, + handlers[i].handler); + } + if (handlers[i].handler != NULL) { + // g_str_hash() can't handle NULL, so use empty string for default + g_hash_table_insert(commands, (gpointer) "", handlers[i].handler); + } + } + return commands; +} + +/*! + * \internal + * \brief Process an incoming request + * + * \param[in,out] request Request to process + * \param[in] handlers Command table created by pcmk__register_handlers() + * + * \return XML to send as reply (or NULL if no reply is needed) + */ +xmlNode * +pcmk__process_request(pcmk__request_t *request, GHashTable *handlers) +{ + xmlNode *(*handler)(pcmk__request_t *request) = NULL; + + CRM_CHECK((request != NULL) && (request->op != NULL) && (handlers != NULL), + return NULL); + + if (pcmk_is_set(request->flags, pcmk__request_sync) + && (request->ipc_client != NULL)) { + CRM_CHECK(request->ipc_client->request_id == request->ipc_id, + return NULL); + } + + handler = g_hash_table_lookup(handlers, request->op); + if (handler == NULL) { + handler = g_hash_table_lookup(handlers, ""); // Default handler + if (handler == NULL) { + crm_info("Ignoring %s request from %s %s with no handler", + request->op, pcmk__request_origin_type(request), + pcmk__request_origin(request)); + return NULL; + } + } + + return (*handler)(request); +} + +/*! + * \internal + * \brief Free memory used within a request (but not the request itself) + * + * \param[in,out] request Request to reset + */ +void +pcmk__reset_request(pcmk__request_t *request) +{ + free(request->op); + request->op = NULL; + + pcmk__reset_result(&(request->result)); +} |