ctdb-event: Add event daemon client code

Signed-off-by: Amitay Isaacs <amitay@gmail.com>
Reviewed-by: Martin Schwenke <martin@meltin.net>

2 files changed, 406 insertions, 0 deletions

diff --git a/ctdb/event/event.h b/ctdb/event/event.h
new file mode 100644
index 00000000000..13617c001df
--- /dev/null
+++ b/ctdb/event/event.h
@@ -0,0 +1,55 @@
+/*
+   CTDB event daemon client
+
+   Copyright (C) Amitay Isaacs  2018
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __CTDB_EVENT_H__
+#define __CTDB_EVENT_H__
+
+#include "event/event_protocol.h"
+
+struct ctdb_event_context;
+
+int ctdb_event_init(TALLOC_CTX *mem_ctx,
+		    struct tevent_context *ev,
+		    struct ctdb_event_context **result);
+
+struct tevent_req *ctdb_event_run_send(TALLOC_CTX *mem_ctx,
+				       struct tevent_context *ev,
+				       struct ctdb_event_context *eclient,
+				       struct ctdb_event_request_run *run);
+bool ctdb_event_run_recv(struct tevent_req *req, int *perr, int *result);
+
+struct tevent_req *ctdb_event_status_send(
+				TALLOC_CTX *mem_ctx,
+				struct tevent_context *ev,
+				struct ctdb_event_context *eclient,
+				struct ctdb_event_request_status *status);
+bool ctdb_event_status_recv(struct tevent_req *req,
+			    int *perr,
+			    int *result,
+			    TALLOC_CTX *mem_ctx,
+			    struct ctdb_event_reply_status **status);
+
+struct tevent_req *ctdb_event_script_send(
+				TALLOC_CTX *mem_ctx,
+				struct tevent_context *ev,
+				struct ctdb_event_context *eclient,
+				struct ctdb_event_request_script *script);
+bool ctdb_event_script_recv(struct tevent_req *req, int *perr, int *result);
+
+#endif /* __CTDB_EVENT_H__ */
diff --git a/ctdb/event/event_client.c b/ctdb/event/event_client.c
new file mode 100644
index 00000000000..d0bee0d0841
--- /dev/null
+++ b/ctdb/event/event_client.c
@@ -0,0 +1,351 @@
+/*
+   CTDB event daemon client
+
+   Copyright (C) Amitay Isaacs  2018
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "replace.h"
+
+#include <talloc.h>
+#include <tevent.h>
+
+#include "lib/util/debug.h"
+#include "lib/util/tevent_unix.h"
+
+#include "common/logging.h"
+#include "common/path.h"
+#include "common/sock_client.h"
+
+#include "event/event_protocol_api.h"
+#include "event/event.h"
+
+struct ctdb_event_context {
+	char *socket;
+	struct sock_client_context *sockc;
+};
+
+struct event_request {
+	struct ctdb_event_header header;
+	struct ctdb_event_request *request;
+};
+
+struct event_reply {
+	struct ctdb_event_header header;
+	struct ctdb_event_reply *reply;
+};
+
+static int event_request_push(void *request_data,
+			      uint32_t reqid,
+			      TALLOC_CTX *mem_ctx,
+			      uint8_t **buf,
+			      size_t *buflen,
+			      void *private_data)
+{
+	struct event_request *r = (struct event_request *)request_data;
+	int ret;
+
+	r->header.reqid = reqid;
+
+	*buflen = ctdb_event_request_len(&r->header, r->request);
+	*buf = talloc_size(mem_ctx, *buflen);
+	if (*buf == NULL) {
+		return ENOMEM;
+	}
+
+	ret = ctdb_event_request_push(&r->header, r->request, *buf, buflen);
+	if (ret != 0) {
+		talloc_free(*buf);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int event_reply_pull(uint8_t *buf,
+			    size_t buflen,
+			    TALLOC_CTX *mem_ctx,
+			    void **reply_data,
+			    void *private_data)
+{
+	struct event_reply *r;
+	int ret;
+
+	r = talloc_zero(mem_ctx, struct event_reply);
+	if (r == NULL) {
+		return ENOMEM;
+	}
+
+	ret = ctdb_event_reply_pull(buf, buflen, &r->header, r, &r->reply);
+	if (ret != 0) {
+		talloc_free(r);
+		return ret;
+	}
+
+	*reply_data = r;
+
+	return 0;
+}
+
+static int event_reply_reqid(uint8_t *buf,
+			     size_t buflen,
+			     uint32_t *reqid,
+			     void *private_data)
+{
+	struct ctdb_event_header header;
+	int ret;
+
+	ret = ctdb_event_header_extract(buf, buflen, &header);
+	if (ret != 0) {
+		return ret;
+	}
+
+	*reqid = header.reqid;
+	return 0;
+}
+
+struct sock_client_proto_funcs event_proto_funcs = {
+	.request_push = event_request_push,
+	.reply_pull = event_reply_pull,
+	.reply_reqid = event_reply_reqid,
+};
+
+int ctdb_event_init(TALLOC_CTX *mem_ctx,
+		    struct tevent_context *ev,
+		    struct ctdb_event_context **result)
+{
+	struct ctdb_event_context *eclient;
+	int ret;
+
+	eclient = talloc_zero(mem_ctx, struct ctdb_event_context);
+	if (eclient == NULL) {
+		return ENOMEM;
+	}
+
+	eclient->socket = path_socket(eclient, "eventd");
+	if (eclient->socket == NULL) {
+		talloc_free(eclient);
+		return ENOMEM;
+	}
+
+	ret = sock_client_setup(eclient,
+				ev,
+				eclient->socket,
+				&event_proto_funcs,
+				eclient,
+				&eclient->sockc);
+	if (ret != 0) {
+		talloc_free(eclient);
+		return ret;
+	}
+
+	*result = eclient;
+	return 0;
+}
+
+/*
+ * Handle request and reply
+ */
+
+struct ctdb_event_msg_state {
+	struct event_request e_request;
+	struct event_reply *e_reply;
+};
+
+static void ctdb_event_msg_done(struct tevent_req *subreq);
+
+static struct tevent_req *ctdb_event_msg_send(
+				TALLOC_CTX *mem_ctx,
+				struct tevent_context *ev,
+				struct ctdb_event_context *eclient,
+				struct ctdb_event_request *request)
+{
+	struct tevent_req *req, *subreq;
+	struct ctdb_event_msg_state *state;
+
+	req = tevent_req_create(mem_ctx, &state, struct ctdb_event_msg_state);
+	if (req == NULL) {
+		return NULL;
+	}
+
+	state->e_request.request = request;
+
+	subreq = sock_client_msg_send(mem_ctx,
+				      ev,
+				      eclient->sockc,
+				      tevent_timeval_zero(),
+				      &state->e_request);
+	if (tevent_req_nomem(subreq, req)) {
+		return tevent_req_post(req, ev);
+	}
+	tevent_req_set_callback(subreq, ctdb_event_msg_done, req);
+
+	return req;
+}
+
+static void ctdb_event_msg_done(struct tevent_req *subreq)
+{
+	struct tevent_req *req = tevent_req_callback_data(
+		subreq, struct tevent_req);
+	struct ctdb_event_msg_state *state = tevent_req_data(
+		req, struct ctdb_event_msg_state);
+	int ret = 0;
+	bool ok;
+
+	ok = sock_client_msg_recv(subreq, &ret, state, &state->e_reply);
+	TALLOC_FREE(subreq);
+	if (!ok) {
+		tevent_req_error(req, ret);
+		return;
+	}
+
+	tevent_req_done(req);
+}
+
+static bool ctdb_event_msg_recv(struct tevent_req *req,
+				int *perr,
+				TALLOC_CTX *mem_ctx,
+				struct ctdb_event_reply **reply)
+{
+	struct ctdb_event_msg_state *state = tevent_req_data(
+		req, struct ctdb_event_msg_state);
+	int ret = 0;
+
+	if (tevent_req_is_unix_error(req, &ret)) {
+		if (perr != NULL) {
+			*perr = ret;
+		}
+		return false;
+	}
+
+	*reply = talloc_steal(mem_ctx, state->e_reply->reply);
+
+	return true;
+}
+
+/*
+ * API functions
+ */
+
+struct tevent_req *ctdb_event_run_send(TALLOC_CTX *mem_ctx,
+				       struct tevent_context *ev,
+				       struct ctdb_event_context *eclient,
+				       struct ctdb_event_request_run *run)
+{
+	struct ctdb_event_request request;
+
+	request.cmd = CTDB_EVENT_CMD_RUN;
+	request.data.run = run;
+
+	return ctdb_event_msg_send(mem_ctx, ev, eclient, &request);
+}
+
+bool ctdb_event_run_recv(struct tevent_req *req, int *perr, int *result)
+{
+	struct ctdb_event_reply *reply = NULL;
+	bool ok;
+
+	ok = ctdb_event_msg_recv(req, perr, req, &reply);
+	if (!ok) {
+		return false;
+	}
+
+	if (reply->cmd != CTDB_EVENT_CMD_RUN) {
+		*result = EPROTO;
+	} else {
+		*result = reply->result;
+	}
+
+	talloc_free(reply);
+	return true;
+}
+
+struct tevent_req *ctdb_event_status_send(
+				TALLOC_CTX *mem_ctx,
+				struct tevent_context *ev,
+				struct ctdb_event_context *eclient,
+				struct ctdb_event_request_status *status)
+{
+	struct ctdb_event_request request;
+
+	request.cmd = CTDB_EVENT_CMD_STATUS;
+	request.data.status = status;
+
+	return ctdb_event_msg_send(mem_ctx, ev, eclient, &request);
+}
+
+bool ctdb_event_status_recv(struct tevent_req *req,
+			    int *perr,
+			    int *result,
+			    TALLOC_CTX *mem_ctx,
+			    struct ctdb_event_reply_status **status)
+{
+	struct ctdb_event_reply *reply = NULL;
+	bool ok;
+
+	ok = ctdb_event_msg_recv(req, perr, req, &reply);
+	if (!ok) {
+		return false;
+	}
+
+	if (reply->cmd != CTDB_EVENT_CMD_STATUS) {
+		*result = EPROTO;
+	} else {
+		*result = reply->result;
+	}
+
+	if (reply->result == 0) {
+		*status = talloc_steal(mem_ctx, reply->data.status);
+	} else {
+		*status = NULL;
+	}
+
+	talloc_free(reply);
+	return true;
+}
+
+struct tevent_req *ctdb_event_script_send(
+				TALLOC_CTX *mem_ctx,
+				struct tevent_context *ev,
+				struct ctdb_event_context *eclient,
+				struct ctdb_event_request_script *script)
+{
+	struct ctdb_event_request request;
+
+	request.cmd = CTDB_EVENT_CMD_SCRIPT;
+	request.data.script = script;
+
+	return ctdb_event_msg_send(mem_ctx, ev, eclient, &request);
+}
+
+bool ctdb_event_script_recv(struct tevent_req *req, int *perr, int *result)
+{
+	struct ctdb_event_reply *reply = NULL;
+	bool ok;
+
+	ok = ctdb_event_msg_recv(req, perr, req, &reply);
+	if (!ok) {
+		return false;
+	}
+
+	if (reply->cmd != CTDB_EVENT_CMD_SCRIPT) {
+		*result = EPROTO;
+	} else {
+		*result = reply->result;
+	}
+
+	talloc_free(reply);
+	return true;
+}