ClusterLabs · clumens · Apr 6, 2026 · Jan 26, 2026 · Jan 26, 2026 · Apr 1, 2026
diff --git a/daemons/attrd/attrd_ipc.c b/daemons/attrd/attrd_ipc.c
@@ -596,8 +596,7 @@ attrd_ipc_dispatch(qb_ipcs_connection_t * c, void *data, size_t size)
 
     if (xml == NULL) {
         pcmk__debug("Unrecognizable IPC data from PID %d", pcmk__client_pid(c));
-        pcmk__ipc_send_ack(client, id, flags, PCMK__XE_ACK, NULL,
-                           CRM_EX_PROTOCOL);
+        pcmk__ipc_send_ack(client, id, flags, NULL, CRM_EX_PROTOCOL);
         return 0;
 
     } else {

diff --git a/daemons/attrd/attrd_sync.c b/daemons/attrd/attrd_sync.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 2022-2025 the Pacemaker project contributors
+ * Copyright 2022-2026 the Pacemaker project contributors
  *
  * The version control history for this file may have further details.
  *
@@ -382,8 +382,7 @@ confirmation_timeout_cb(gpointer data)
                         client->id);
             pcmk__ipc_send_ack(client, action->ipc_id,
                                action->flags|crm_ipc_client_response,
-                               PCMK__XE_ACK, ATTRD_PROTOCOL_VERSION,
-                               CRM_EX_TIMEOUT);
+                               ATTRD_PROTOCOL_VERSION, CRM_EX_TIMEOUT);
 
             g_hash_table_iter_remove(&iter);
             pcmk__trace("%u requests now in expected confirmations table",

diff --git a/daemons/attrd/pacemaker-attrd.h b/daemons/attrd/pacemaker-attrd.h
@@ -53,9 +53,9 @@
 #define ATTRD_SUPPORTS_MULTI_MESSAGE(x) ((x) >= 4)
 #define ATTRD_SUPPORTS_CONFIRMATION(x)  ((x) >= 5)
 
-#define attrd_send_ack(client, id, flags)                       \
-    pcmk__ipc_send_ack((client), (id), (flags), PCMK__XE_ACK,   \
-                       ATTRD_PROTOCOL_VERSION, CRM_EX_INDETERMINATE)
+#define attrd_send_ack(client, id, flags)                               \
+    pcmk__ipc_send_ack((client), (id), (flags), ATTRD_PROTOCOL_VERSION, \
+                       CRM_EX_INDETERMINATE)
 
 void attrd_init_mainloop(void);
 void attrd_run_mainloop(void);

diff --git a/daemons/based/based_ipc.c b/daemons/based/based_ipc.c
@@ -122,8 +122,7 @@ dispatch_common(qb_ipcs_connection_t *c, void *data, bool privileged)
 
     if (msg == NULL) {
         pcmk__debug("Unrecognizable IPC data from PID %d", pcmk__client_pid(c));
-        pcmk__ipc_send_ack(client, id, flags, PCMK__XE_NACK, NULL,
-                           CRM_EX_PROTOCOL);
+        pcmk__ipc_send_ack(client, id, flags, NULL, CRM_EX_PROTOCOL);
         return 0;
     }
 
@@ -200,7 +199,7 @@ dispatch_common(qb_ipcs_connection_t *c, void *data, bool privileged)
             status = CRM_EX_INVALID_PARAM;
         }
 
-        pcmk__ipc_send_ack(client, id, flags, PCMK__XE_ACK, NULL, status);
+        pcmk__ipc_send_ack(client, id, flags, NULL, status);
         return 0;
     }
 

diff --git a/daemons/controld/controld_control.c b/daemons/controld/controld_control.c
@@ -403,12 +403,10 @@ dispatch_controller_ipc(qb_ipcs_connection_t * c, void *data, size_t size)
     }
 
     if (msg == NULL) {
-        pcmk__ipc_send_ack(client, id, flags, PCMK__XE_ACK, NULL,
-                           CRM_EX_PROTOCOL);
+        pcmk__ipc_send_ack(client, id, flags, NULL, CRM_EX_PROTOCOL);
         return 0;
     }
-    pcmk__ipc_send_ack(client, id, flags, PCMK__XE_ACK, NULL,
-                       CRM_EX_INDETERMINATE);
+    pcmk__ipc_send_ack(client, id, flags, NULL, CRM_EX_INDETERMINATE);
 
     pcmk__assert(client->user != NULL);
     pcmk__update_acl_user(msg, PCMK__XA_CRM_USER, client->user);

diff --git a/daemons/execd/execd_ipc.c b/daemons/execd/execd_ipc.c
@@ -170,7 +170,7 @@ execd_ipc_dispatch(qb_ipcs_connection_t *c, void *data, size_t size)
 
     if ((msg == NULL) || execd_invalid_msg(msg)) {
         pcmk__debug("Unrecognizable IPC data from PID %d", pcmk__client_pid(c));
-        pcmk__ipc_send_ack(client, id, flags, PCMK__XE_NACK, NULL, CRM_EX_PROTOCOL);
+        pcmk__ipc_send_ack(client, id, flags, NULL, CRM_EX_PROTOCOL);
     } else {
         pcmk__request_t request = {
             .ipc_client     = client,

diff --git a/daemons/execd/execd_messages.c b/daemons/execd/execd_messages.c
@@ -395,7 +395,7 @@ static xmlNode *
 handle_unknown_request(pcmk__request_t *request)
 {
     pcmk__ipc_send_ack(request->ipc_client, request->ipc_id, request->ipc_flags,
-                       PCMK__XE_NACK, NULL, CRM_EX_PROTOCOL);
+                       NULL, CRM_EX_PROTOCOL);
 
     pcmk__format_result(&request->result, CRM_EX_PROTOCOL, PCMK_EXEC_INVALID,
                         "Unknown request type '%s' (bug?)",

diff --git a/daemons/execd/remoted_tls.c b/daemons/execd/remoted_tls.c
@@ -127,16 +127,9 @@ lrmd_remote_client_msg(gpointer data)
 
     msg = pcmk__remote_message_xml(client->remote);
 
-    if (msg == NULL) {
+    if ((msg == NULL) || execd_invalid_msg(msg)) {
         pcmk__debug("Unrecognizable IPC data from PID %d", client->pid);
-    } else if (execd_invalid_msg(msg)) {
-        int id = 0;
 
-        pcmk__debug("Unrecognizable IPC data from PID %d", client->pid);
-
-        pcmk__xe_get_int(msg, PCMK__XA_LRMD_REMOTE_MSG_ID, &id);
-        pcmk__ipc_send_ack(client, id, crm_ipc_client_response, PCMK__XE_NACK,
-                           NULL, CRM_EX_PROTOCOL);
     } else {
         pcmk__request_t request = {
             .ipc_client     = client,

diff --git a/daemons/fenced/fenced_commands.c b/daemons/fenced/fenced_commands.c
@@ -3418,8 +3418,7 @@ handle_notify_request(pcmk__request_t *request)
     pcmk__set_result(&request->result, CRM_EX_OK, PCMK_EXEC_DONE, NULL);
     pcmk__set_request_flags(request, pcmk__request_reuse_options);
 
-    return pcmk__ipc_create_ack(request->ipc_flags, PCMK__XE_ACK, NULL,
-                                CRM_EX_OK);
+    return pcmk__ipc_create_ack(request->ipc_flags, NULL, CRM_EX_OK);
 }
 
 // STONITH_OP_RELAY

diff --git a/daemons/fenced/fenced_ipc.c b/daemons/fenced/fenced_ipc.c
@@ -137,7 +137,7 @@ fenced_ipc_dispatch(qb_ipcs_connection_t *c, void *data, size_t size)
 
     if (msg == NULL) {
         pcmk__debug("Unrecognizable IPC data from PID %d", pcmk__client_pid(c));
-        pcmk__ipc_send_ack(client, id, flags, PCMK__XE_NACK, NULL, CRM_EX_PROTOCOL);
+        pcmk__ipc_send_ack(client, id, flags, NULL, CRM_EX_PROTOCOL);
         return 0;
     }
 

diff --git a/daemons/pacemakerd/pcmkd_ipc.c b/daemons/pacemakerd/pcmkd_ipc.c
@@ -149,8 +149,7 @@ pacemakerd_ipc_dispatch(qb_ipcs_connection_t *c, void *data, size_t size)
 
     if (msg == NULL) {
         pcmk__debug("Unrecognizable IPC data from PID %d", pcmk__client_pid(c));
-        pcmk__ipc_send_ack(client, id, flags, PCMK__XE_ACK, NULL,
-                           CRM_EX_PROTOCOL);
+        pcmk__ipc_send_ack(client, id, flags, NULL, CRM_EX_PROTOCOL);
         return 0;
 
     } else {

diff --git a/daemons/pacemakerd/pcmkd_messages.c b/daemons/pacemakerd/pcmkd_messages.c
@@ -34,7 +34,7 @@ handle_node_cache_request(pcmk__request_t *request)
                 pcmk__client_name(request->ipc_client));
 
     pcmk__ipc_send_ack(request->ipc_client, request->ipc_id, request->ipc_flags,
-                       PCMK__XE_ACK, NULL, CRM_EX_OK);
+                       NULL, CRM_EX_OK);
     return NULL;
 }
 
@@ -55,7 +55,7 @@ handle_ping_request(pcmk__request_t *request)
                 pcmk__s(pcmk__xe_get(msg, PCMK_XA_ORIGIN), ""));
 
     pcmk__ipc_send_ack(request->ipc_client, request->ipc_id, request->ipc_flags,
-                       PCMK__XE_ACK, NULL, CRM_EX_INDETERMINATE);
+                       NULL, CRM_EX_INDETERMINATE);
 
     ping = pcmk__xe_create(NULL, PCMK__XE_PING_RESPONSE);
     value = pcmk__xe_get(msg, PCMK__XA_CRM_SYS_TO);
@@ -114,7 +114,7 @@ handle_shutdown_request(pcmk__request_t *request)
                                 pcmk__client_privileged);
 
     pcmk__ipc_send_ack(request->ipc_client, request->ipc_id, request->ipc_flags,
-                       PCMK__XE_ACK, NULL, CRM_EX_INDETERMINATE);
+                       NULL, CRM_EX_INDETERMINATE);
 
     shutdown = pcmk__xe_create(NULL, PCMK__XE_SHUTDOWN);
 
@@ -152,7 +152,7 @@ static xmlNode *
 handle_unknown_request(pcmk__request_t *request)
 {
     pcmk__ipc_send_ack(request->ipc_client, request->ipc_id, request->ipc_flags,
-                       PCMK__XE_ACK, NULL, CRM_EX_PROTOCOL);
+                       NULL, CRM_EX_PROTOCOL);
 
     pcmk__format_result(&request->result, CRM_EX_PROTOCOL, PCMK_EXEC_INVALID,
                         "Unknown request type '%s' (bug?)",

diff --git a/daemons/schedulerd/schedulerd_ipc.c b/daemons/schedulerd/schedulerd_ipc.c
@@ -104,22 +104,19 @@ schedulerd_ipc_dispatch(qb_ipcs_connection_t *c, void *data, size_t size)
 
     if (msg == NULL) {
         pcmk__debug("Unrecognizable IPC data from PID %d", pcmk__client_pid(c));
-        pcmk__ipc_send_ack(client, id, flags, PCMK__XE_ACK, NULL,
-                           CRM_EX_PROTOCOL);
+        pcmk__ipc_send_ack(client, id, flags, NULL, CRM_EX_PROTOCOL);
         return 0;
     }
 
     sys_to = pcmk__xe_get(msg, PCMK__XA_CRM_SYS_TO);
 
     if (pcmk__str_eq(pcmk__xe_get(msg, PCMK__XA_SUBT), PCMK__VALUE_RESPONSE,
                      pcmk__str_none)) {
-        pcmk__ipc_send_ack(client, id, flags, PCMK__XE_ACK, NULL,
-                           CRM_EX_INDETERMINATE);
+        pcmk__ipc_send_ack(client, id, flags, NULL, CRM_EX_INDETERMINATE);
         pcmk__info("Ignoring IPC reply from %s", pcmk__client_name(client));
 
     } else if (!pcmk__str_eq(sys_to, CRM_SYSTEM_PENGINE, pcmk__str_none)) {
-        pcmk__ipc_send_ack(client, id, flags, PCMK__XE_ACK, NULL,
-                           CRM_EX_INDETERMINATE);
+        pcmk__ipc_send_ack(client, id, flags, NULL, CRM_EX_INDETERMINATE);
         pcmk__info("Ignoring invalid IPC message: to '%s' not "
                    CRM_SYSTEM_PENGINE, pcmk__s(sys_to, ""));
 

diff --git a/daemons/schedulerd/schedulerd_messages.c b/daemons/schedulerd/schedulerd_messages.c
@@ -79,7 +79,7 @@ handle_pecalc_request(pcmk__request_t *request)
     pcmk_scheduler_t *scheduler = init_scheduler();
 
     pcmk__ipc_send_ack(request->ipc_client, request->ipc_id, request->ipc_flags,
-                       PCMK__XE_ACK, NULL, CRM_EX_INDETERMINATE);
+                       NULL, CRM_EX_INDETERMINATE);
 
     digest = pcmk__digest_xml(xml_data, false);
     converted = pcmk__xml_copy(NULL, xml_data);
@@ -187,7 +187,7 @@ static xmlNode *
 handle_unknown_request(pcmk__request_t *request)
 {
     pcmk__ipc_send_ack(request->ipc_client, request->ipc_id, request->ipc_flags,
-                       PCMK__XE_ACK, NULL, CRM_EX_PROTOCOL);
+                       NULL, CRM_EX_PROTOCOL);
 
     pcmk__format_result(&request->result, CRM_EX_PROTOCOL, PCMK_EXEC_INVALID,
                         "Unknown request type '%s' (bug?)",
@@ -199,7 +199,7 @@ static xmlNode *
 handle_hello_request(pcmk__request_t *request)
 {
     pcmk__ipc_send_ack(request->ipc_client, request->ipc_id, request->ipc_flags,
-                       PCMK__XE_ACK, NULL, CRM_EX_INDETERMINATE);
+                       NULL, CRM_EX_INDETERMINATE);
 
     pcmk__trace("Received IPC hello from %s",
                 pcmk__client_name(request->ipc_client));

diff --git a/include/crm/common/ipc_internal.h b/include/crm/common/ipc_internal.h
@@ -216,15 +216,15 @@ void pcmk__drop_all_clients(qb_ipcs_service_t *s);
 void pcmk__set_client_queue_max(pcmk__client_t *client, const char *qmax);
 
 xmlNode *pcmk__ipc_create_ack_as(const char *function, int line, uint32_t flags,
-                                 const char *tag, const char *ver, crm_exit_t status);
-#define pcmk__ipc_create_ack(flags, tag, ver, st) \
-    pcmk__ipc_create_ack_as(__func__, __LINE__, (flags), (tag), (ver), (st))
+                                 const char *ver, crm_exit_t status);
+#define pcmk__ipc_create_ack(flags, ver, st) \
+    pcmk__ipc_create_ack_as(__func__, __LINE__, (flags), (ver), (st))
 
 int pcmk__ipc_send_ack_as(const char *function, int line, pcmk__client_t *c,
-                          uint32_t request, uint32_t flags, const char *tag,
-                          const char *ver, crm_exit_t status);
-#define pcmk__ipc_send_ack(c, req, flags, tag, ver, st) \
-    pcmk__ipc_send_ack_as(__func__, __LINE__, (c), (req), (flags), (tag), (ver), (st))
+                          uint32_t request, uint32_t flags, const char *ver,
+                          crm_exit_t status);
+#define pcmk__ipc_send_ack(c, req, flags, ver, st) \
+    pcmk__ipc_send_ack_as(__func__, __LINE__, (c), (req), (flags), (ver), (st))
 
 int pcmk__ipc_prepare_iov(uint32_t request, const GString *message,
                           uint16_t index, struct iovec **result, ssize_t *bytes);

diff --git a/lib/cib/cib_native.c b/lib/cib/cib_native.c
@@ -34,6 +34,20 @@ typedef struct {
     mainloop_io_t *source;
 } cib_native_opaque_t;
 
+static bool
+ack_is_failure(const xmlNode *reply)
+{
+    int status = 0;
+
+    pcmk__xe_get_int(reply, PCMK_XA_STATUS, &status);
+    if (status != CRM_EX_OK) {
+        pcmk__err("Received error response from based: %s", crm_exit_str(status));
+        return true;
+    }
+
+    return false;
+}
+
 static int
 cib_native_perform_op_delegate(cib_t *cib, const char *op, const char *host,
                                const char *section, xmlNode *data,
@@ -90,6 +104,15 @@ cib_native_perform_op_delegate(cib_t *cib, const char *op, const char *host,
         goto done;
     }
 
+    /* The only reason we can receive an ACK here is if dispatch_common ->
+     * pcmk__client_data2xml processed something that's not valid XML.
+     * dispatch_common does not return ACK, unlike other daemons.
+     */
+    if (pcmk__xe_is(op_reply, PCMK__XE_ACK) && ack_is_failure(op_reply)) {
+        rc = -EPROTO;
+        goto done;
+    }
+
     pcmk__log_xml_trace(op_reply, "Reply");
 
     if (!(call_options & cib_sync_call)) {
@@ -321,6 +344,15 @@ cib_native_signon(cib_t *cib, const char *name, enum cib_conn_type type)
             goto done;
         }
 
+        /* The only reason we can receive an ACK here is if dispatch_common ->
+         * pcmk__client_data2xml processed something that's not valid XML.
+         * dispatch_common does not return ACK, unlike other daemons.
+         */
+        if (pcmk__xe_is(reply, PCMK__XE_ACK) && ack_is_failure(reply)) {
+            rc = -EPROTO;
+            goto done;
+        }
+
         msg_type = pcmk__xe_get(reply, PCMK__XA_CIB_OP);
 
         pcmk__log_xml_trace(reply, "reg-reply");
@@ -386,6 +418,10 @@ cib_native_register_notification(cib_t *cib, const char *callback, int enabled)
         pcmk__xe_set(notify_msg, PCMK__XA_CIB_OP, PCMK__VALUE_CIB_NOTIFY);
         pcmk__xe_set(notify_msg, PCMK__XA_CIB_NOTIFY_TYPE, callback);
         pcmk__xe_set_int(notify_msg, PCMK__XA_CIB_NOTIFY_ACTIVATE, enabled);
+
+        /* We don't care about the reply here, so there's no need to check
+         * if we got an ACK in response.
+         */
         rc = crm_ipc_send(native->ipc, notify_msg, crm_ipc_client_response,
                           1000 * cib->call_timeout, NULL);
         if (rc <= 0) {

diff --git a/lib/cib/cib_remote.c b/lib/cib/cib_remote.c
@@ -48,6 +48,20 @@ typedef struct {
     int timeout_sec;
 } cib_remote_opaque_t;
 
+static bool
+ack_is_failure(const xmlNode *reply)
+{
+    int status = 0;
+
+    pcmk__xe_get_int(reply, PCMK_XA_STATUS, &status);
+    if (status != CRM_EX_OK) {
+        pcmk__err("Received error response from based: %s", crm_exit_str(status));
+        return true;
+    }
+
+    return false;
+}
+
 static int
 cib_remote_perform_op(cib_t *cib, const char *op, const char *host,
                       const char *section, xmlNode *data,
@@ -151,11 +165,22 @@ cib_remote_perform_op(cib_t *cib, const char *op, const char *host,
     if (rc == ENOTCONN) {
         pcmk__err("Disconnected while waiting for reply");
         return -ENOTCONN;
-    } else if (op_reply == NULL) {
+    }
+
+    if (op_reply == NULL) {
         pcmk__err("No reply message - empty");
         return -ENOMSG;
     }
 
+    /* The only reason we can receive an ACK here is if dispatch_common ->
+     * pcmk__client_data2xml processed something that's not valid XML.
+     * dispatch_common does not return ACK, unlike other daemons.
+     */
+    if (pcmk__xe_is(op_reply, PCMK__XE_ACK) && ack_is_failure(op_reply)) {
+        pcmk__xml_free(op_reply);
+        return -EPROTO;
+    }
+
     pcmk__trace("Synchronous reply received");
 
     /* Start processing the reply... */
@@ -432,6 +457,15 @@ cib_tls_signon(cib_t *cib, pcmk__remote_t *connection, gboolean event_channel)
         goto done;
     }
 
+    /* The only reason we can receive an ACK here is if dispatch_common ->
+     * pcmk__client_data2xml processed something that's not valid XML.
+     * dispatch_common does not return ACK, unlike other daemons.
+     */
+    if (pcmk__xe_is(answer, PCMK__XE_ACK) && ack_is_failure(answer)) {
+        rc = -EPROTO;
+        goto done;
+    }
+
     pcmk__log_xml_trace(answer, "reg-reply");
 
     /* grab the token */