ctdb-protocol: Add a generic packet header

This will avoid duplication when new daemons (and new client-server
protocols) are created out of the main ctdb daemon.

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

3 files changed, 103 insertions, 0 deletions

diff --git a/ctdb/protocol/protocol.h b/ctdb/protocol/protocol.h
index 67a66c715c1..ad757d8c27d 100644
--- a/ctdb/protocol/protocol.h
+++ b/ctdb/protocol/protocol.h
@@ -1008,6 +1008,15 @@ struct ctdb_g_lock_list {
 };
 
 /*
+ * Generic packet header
+ */
+
+struct sock_packet_header {
+	uint32_t length;
+	uint32_t reqid;
+};
+
+/*
  * Eventd protocol
  */
 
diff --git a/ctdb/protocol/protocol_api.h b/ctdb/protocol/protocol_api.h
index 522b009b151..22fc4483205 100644
--- a/ctdb/protocol/protocol_api.h
+++ b/ctdb/protocol/protocol_api.h
@@ -677,6 +677,19 @@ int ctdb_event_reply_pull(uint8_t *buf, size_t buflen,
 int ctdb_allocate_pkt(TALLOC_CTX *mem_ctx, size_t datalen,
 		      uint8_t **buf, size_t *buflen);
 
+/* From protocol/protocol_sock.c */
+
+size_t sock_packet_header_len(struct sock_packet_header *in);
+void sock_packet_header_push(struct sock_packet_header *in, uint8_t *buf,
+			     size_t *npush);
+int sock_packet_header_pull(uint8_t *buf, size_t buflen,
+			    struct sock_packet_header *out, size_t *npull);
+
+void sock_packet_header_set_reqid(struct sock_packet_header *h,
+				  uint32_t reqid);
+void sock_packet_header_set_length(struct sock_packet_header *h,
+				   uint32_t length);
+
 /* From protocol/protocol_util.c */
 
 const char *ctdb_runstate_to_string(enum ctdb_runstate runstate);
diff --git a/ctdb/protocol/protocol_sock.c b/ctdb/protocol/protocol_sock.c
new file mode 100644
index 00000000000..e32f08767e7
--- /dev/null
+++ b/ctdb/protocol/protocol_sock.c
@@ -0,0 +1,81 @@
+/*
+   CTDB generic sock packet marshalling
+
+   Copyright (C) Amitay Isaacs  2017
+
+   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 "system/network.h"
+
+#include <talloc.h>
+
+#include "protocol.h"
+#include "protocol_private.h"
+#include "protocol_api.h"
+
+size_t sock_packet_header_len(struct sock_packet_header *in)
+{
+	return ctdb_uint32_len(&in->length) +
+		ctdb_uint32_len(&in->reqid);
+}
+
+void sock_packet_header_push(struct sock_packet_header *in, uint8_t *buf,
+			     size_t *npush)
+{
+	size_t offset = 0, np;
+
+	ctdb_uint32_push(&in->length, buf+offset, &np);
+	offset += np;
+
+	ctdb_uint32_push(&in->reqid, buf+offset, &np);
+	offset += np;
+
+	*npush = offset;
+}
+
+int sock_packet_header_pull(uint8_t *buf, size_t buflen,
+			    struct sock_packet_header *out, size_t *npull)
+{
+	size_t offset = 0, np;
+	int ret;
+
+	ret = ctdb_uint32_pull(buf+offset, buflen-offset, &out->length, &np);
+	if (ret != 0) {
+		return ret;
+	}
+	offset += np;
+
+	ret = ctdb_uint32_pull(buf+offset, buflen-offset, &out->reqid, &np);
+	if (ret != 0) {
+		return ret;
+	}
+	offset += np;
+
+	*npull = offset;
+	return 0;
+}
+
+void sock_packet_header_set_reqid(struct sock_packet_header *h,
+				  uint32_t reqid)
+{
+	h->reqid = reqid;
+}
+
+void sock_packet_header_set_length(struct sock_packet_header *h,
+				   uint32_t length)
+{
+	h->length = length;
+}