ctdb-protocol: Return required buffer size in push functions

If the buffer size provided is not sufficient, then return the required
buffer length.

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

8 files changed, 96 insertions, 55 deletions

diff --git a/ctdb/client/client_call.c b/ctdb/client/client_call.c
index d1a6c2164f6..088ba67a503 100644
--- a/ctdb/client/client_call.c
+++ b/ctdb/client/client_call.c
@@ -98,7 +98,7 @@ struct tevent_req *ctdb_client_call_send(TALLOC_CTX *mem_ctx,
 		return tevent_req_post(req, ev);
 	}
 
-	ret = ctdb_req_call_push(&h, request, buf, buflen);
+	ret = ctdb_req_call_push(&h, request, buf, &buflen);
 	if (ret != 0) {
 		tevent_req_error(req, ret);
 		return tevent_req_post(req, ev);
diff --git a/ctdb/client/client_control.c b/ctdb/client/client_control.c
index ecbdb2dd6a4..1755eccf65d 100644
--- a/ctdb/client/client_control.c
+++ b/ctdb/client/client_control.c
@@ -105,7 +105,7 @@ struct tevent_req *ctdb_client_control_send(TALLOC_CTX *mem_ctx,
 		return tevent_req_post(req, ev);
 	}
 
-	ret = ctdb_req_control_push(&h, request, buf, buflen);
+	ret = ctdb_req_control_push(&h, request, buf, &buflen);
 	if (ret != 0) {
 		tevent_req_error(req, ret);
 		return tevent_req_post(req, ev);
diff --git a/ctdb/client/client_message.c b/ctdb/client/client_message.c
index 9fb60a89ee1..03fcfc6690f 100644
--- a/ctdb/client/client_message.c
+++ b/ctdb/client/client_message.c
@@ -92,7 +92,7 @@ struct tevent_req *ctdb_client_message_send(TALLOC_CTX *mem_ctx,
 		return tevent_req_post(req, ev);
 	}
 
-	ret = ctdb_req_message_push(&h, message, buf, buflen);
+	ret = ctdb_req_message_push(&h, message, buf, &buflen);
 	if (ret != 0) {
 		tevent_req_error(req, ret);
 		return tevent_req_post(req, ev);
diff --git a/ctdb/protocol/protocol_api.h b/ctdb/protocol/protocol_api.h
index 78cc6212787..0f781ccce7a 100644
--- a/ctdb/protocol/protocol_api.h
+++ b/ctdb/protocol/protocol_api.h
@@ -90,7 +90,7 @@ size_t ctdb_req_call_len(struct ctdb_req_header *h,
 
 int ctdb_req_call_push(struct ctdb_req_header *h,
 		       struct ctdb_req_call *c,
-		       uint8_t *buf, size_t buflen);
+		       uint8_t *buf, size_t *buflen);
 
 int ctdb_req_call_pull(uint8_t *buf, size_t buflen,
 		       struct ctdb_req_header *h,
@@ -102,7 +102,7 @@ size_t ctdb_reply_call_len(struct ctdb_req_header *h,
 
 int ctdb_reply_call_push(struct ctdb_req_header *h,
 			 struct ctdb_reply_call *c,
-			 uint8_t *buf, size_t buflen);
+			 uint8_t *buf, size_t *buflen);
 
 int ctdb_reply_call_pull(uint8_t *buf, size_t buflen,
 			 struct ctdb_req_header *h,
@@ -114,7 +114,7 @@ size_t ctdb_reply_error_len(struct ctdb_req_header *h,
 
 int ctdb_reply_error_push(struct ctdb_req_header *h,
 			  struct ctdb_reply_error *c,
-			  uint8_t *buf, size_t buflen);
+			  uint8_t *buf, size_t *buflen);
 
 int ctdb_reply_error_pull(uint8_t *buf, size_t buflen,
 			  struct ctdb_req_header *h,
@@ -126,7 +126,7 @@ size_t ctdb_req_dmaster_len(struct ctdb_req_header *h,
 
 int ctdb_req_dmaster_push(struct ctdb_req_header *h,
 			  struct ctdb_req_dmaster *c,
-			  uint8_t *buf, size_t buflen);
+			  uint8_t *buf, size_t *buflen);
 
 int ctdb_req_dmaster_pull(uint8_t *buf, size_t buflen,
 			  struct ctdb_req_header *h,
@@ -138,7 +138,7 @@ size_t ctdb_reply_dmaster_len(struct ctdb_req_header *h,
 
 int ctdb_reply_dmaster_push(struct ctdb_req_header *h,
 			    struct ctdb_reply_dmaster *c,
-			    uint8_t *buf, size_t buflen);
+			    uint8_t *buf, size_t *buflen);
 
 int ctdb_reply_dmaster_pull(uint8_t *buf, size_t buflen,
 			    struct ctdb_req_header *h,
@@ -152,7 +152,7 @@ size_t ctdb_req_control_len(struct ctdb_req_header *h,
 
 int ctdb_req_control_push(struct ctdb_req_header *h,
 			  struct ctdb_req_control *c,
-			  uint8_t *buf, size_t buflen);
+			  uint8_t *buf, size_t *buflen);
 
 int ctdb_req_control_pull(uint8_t *buf, size_t buflen,
 			  struct ctdb_req_header *h,
@@ -164,7 +164,7 @@ size_t ctdb_reply_control_len(struct ctdb_req_header *h,
 
 int ctdb_reply_control_push(struct ctdb_req_header *h,
 			    struct ctdb_reply_control *c,
-			    uint8_t *buf, size_t buflen);
+			    uint8_t *buf, size_t *buflen);
 
 int ctdb_reply_control_pull(uint8_t *buf, size_t buflen, uint32_t opcode,
 			    struct ctdb_req_header *h,
@@ -654,7 +654,7 @@ size_t ctdb_req_message_len(struct ctdb_req_header *h,
 
 int ctdb_req_message_push(struct ctdb_req_header *h,
 			  struct ctdb_req_message *c,
-			  uint8_t *buf, size_t buflen);
+			  uint8_t *buf, size_t *buflen);
 
 int ctdb_req_message_pull(uint8_t *buf, size_t buflen,
 			  struct ctdb_req_header *h,
@@ -666,7 +666,7 @@ size_t ctdb_req_message_data_len(struct ctdb_req_header *h,
 
 int ctdb_req_message_data_push(struct ctdb_req_header *h,
 			       struct ctdb_req_message_data *c,
-			       uint8_t *buf, size_t buflen);
+			       uint8_t *buf, size_t *buflen);
 
 int ctdb_req_message_data_pull(uint8_t *buf, size_t buflen,
 			       struct ctdb_req_header *h,
diff --git a/ctdb/protocol/protocol_call.c b/ctdb/protocol/protocol_call.c
index 441bf6048a2..a2b24cf0843 100644
--- a/ctdb/protocol/protocol_call.c
+++ b/ctdb/protocol/protocol_call.c
@@ -78,7 +78,7 @@ size_t ctdb_req_call_len(struct ctdb_req_header *h, struct ctdb_req_call *c)
 }
 
 int ctdb_req_call_push(struct ctdb_req_header *h, struct ctdb_req_call *c,
-		       uint8_t *buf, size_t buflen)
+		       uint8_t *buf, size_t *buflen)
 {
 	struct ctdb_req_call_wire *wire =
 		(struct ctdb_req_call_wire *)buf;
@@ -89,11 +89,12 @@ int ctdb_req_call_push(struct ctdb_req_header *h, struct ctdb_req_call *c,
 	}
 
 	length = ctdb_req_call_len(h, c);
-	if (buflen < length) {
+	if (*buflen < length) {
+		*buflen = length;
 		return EMSGSIZE;
 	}
 
-	h->length = buflen;
+	h->length = *buflen;
 	ctdb_req_header_push(h, (uint8_t *)&wire->hdr);
 
 	wire->flags = c->flags;
@@ -160,18 +161,19 @@ size_t ctdb_reply_call_len(struct ctdb_req_header *h,
 }
 
 int ctdb_reply_call_push(struct ctdb_req_header *h, struct ctdb_reply_call *c,
-			 uint8_t *buf, size_t buflen)
+			 uint8_t *buf, size_t *buflen)
 {
 	struct ctdb_reply_call_wire *wire =
 		(struct ctdb_reply_call_wire *)buf;
 	size_t length;
 
 	length = ctdb_reply_call_len(h, c);
-	if (buflen < length) {
+	if (*buflen < length) {
+		*buflen = length;
 		return EMSGSIZE;
 	}
 
-	h->length = buflen;
+	h->length = *buflen;
 	ctdb_req_header_push(h, (uint8_t *)&wire->hdr);
 
 	wire->status = c->status;
@@ -224,18 +226,19 @@ size_t ctdb_reply_error_len(struct ctdb_req_header *h,
 }
 
 int ctdb_reply_error_push(struct ctdb_req_header *h, struct ctdb_reply_error *c,
-			  uint8_t *buf, size_t buflen)
+			  uint8_t *buf, size_t *buflen)
 {
 	struct ctdb_reply_error_wire *wire =
 		(struct ctdb_reply_error_wire *)buf;
 	size_t length;
 
 	length = ctdb_reply_error_len(h, c);
-	if (buflen < length) {
+	if (*buflen < length) {
+		*buflen = length;
 		return EMSGSIZE;
 	}
 
-	h->length = buflen;
+	h->length = *buflen;
 	ctdb_req_header_push(h, (uint8_t *)&wire->hdr);
 
 	wire->status = c->status;
@@ -288,18 +291,19 @@ size_t ctdb_req_dmaster_len(struct ctdb_req_header *h,
 }
 
 int ctdb_req_dmaster_push(struct ctdb_req_header *h, struct ctdb_req_dmaster *c,
-			  uint8_t *buf, size_t buflen)
+			  uint8_t *buf, size_t *buflen)
 {
 	struct ctdb_req_dmaster_wire *wire =
 		(struct ctdb_req_dmaster_wire *)buf;
 	size_t length;
 
 	length = ctdb_req_dmaster_len(h, c);
-	if (buflen < length) {
+	if (*buflen < length) {
+		*buflen = length;
 		return EMSGSIZE;
 	}
 
-	h->length = buflen;
+	h->length = *buflen;
 	ctdb_req_header_push(h, (uint8_t *)&wire->hdr);
 
 	wire->db_id = c->db_id;
@@ -365,18 +369,19 @@ size_t ctdb_reply_dmaster_len(struct ctdb_req_header *h,
 
 int ctdb_reply_dmaster_push(struct ctdb_req_header *h,
 			    struct ctdb_reply_dmaster *c,
-			    uint8_t *buf, size_t buflen)
+			    uint8_t *buf, size_t *buflen)
 {
 	struct ctdb_reply_dmaster_wire *wire =
 		(struct ctdb_reply_dmaster_wire *)buf;
 	size_t length;
 
 	length = ctdb_reply_dmaster_len(h, c);
-	if (buflen < length) {
+	if (*buflen < length) {
+		*buflen = length;
 		return EMSGSIZE;
 	}
 
-	h->length = buflen;
+	h->length = *buflen;
 	ctdb_req_header_push(h, (uint8_t *)&wire->hdr);
 
 	wire->db_id = c->db_id;
diff --git a/ctdb/protocol/protocol_control.c b/ctdb/protocol/protocol_control.c
index 83ddfbee4fc..fc2e6da0277 100644
--- a/ctdb/protocol/protocol_control.c
+++ b/ctdb/protocol/protocol_control.c
@@ -1899,18 +1899,19 @@ size_t ctdb_req_control_len(struct ctdb_req_header *h,
 
 int ctdb_req_control_push(struct ctdb_req_header *h,
 			  struct ctdb_req_control *request,
-			  uint8_t *buf, size_t buflen)
+			  uint8_t *buf, size_t *buflen)
 {
 	struct ctdb_req_control_wire *wire =
 		(struct ctdb_req_control_wire *)buf;
 	size_t length;
 
 	length = ctdb_req_control_len(h, request);
-	if (buflen < length) {
+	if (*buflen < length) {
+		*buflen = length;
 		return EMSGSIZE;
 	}
 
-	h->length = buflen;
+	h->length = *buflen;
 	ctdb_req_header_push(h, (uint8_t *)&wire->hdr);
 
 	wire->opcode = request->opcode;
@@ -1976,18 +1977,19 @@ size_t ctdb_reply_control_len(struct ctdb_req_header *h,
 
 int ctdb_reply_control_push(struct ctdb_req_header *h,
 			    struct ctdb_reply_control *reply,
-			    uint8_t *buf, size_t buflen)
+			    uint8_t *buf, size_t *buflen)
 {
 	struct ctdb_reply_control_wire *wire =
 		(struct ctdb_reply_control_wire *)buf;
 	size_t length;
 
 	length = ctdb_reply_control_len(h, reply);
-	if (buflen < length) {
+	if (*buflen < length) {
+		*buflen = length;
 		return EMSGSIZE;
 	}
 
-	h->length = buflen;
+	h->length = *buflen;
 	ctdb_req_header_push(h, (uint8_t *)&wire->hdr);
 
 	wire->status = reply->status;
diff --git a/ctdb/protocol/protocol_message.c b/ctdb/protocol/protocol_message.c
index 2b45a63d7a2..291ebe6f679 100644
--- a/ctdb/protocol/protocol_message.c
+++ b/ctdb/protocol/protocol_message.c
@@ -289,18 +289,19 @@ size_t ctdb_req_message_len(struct ctdb_req_header *h,
 
 int ctdb_req_message_push(struct ctdb_req_header *h,
 			  struct ctdb_req_message *message,
-			  uint8_t *buf, size_t buflen)
+			  uint8_t *buf, size_t *buflen)
 {
 	struct ctdb_req_message_wire *wire =
 		(struct ctdb_req_message_wire *)buf;
 	size_t length;
 
 	length = ctdb_req_message_len(h, message);
-	if (buflen < length) {
+	if (*buflen < length) {
+		*buflen = length;
 		return EMSGSIZE;
 	}
 
-	h->length = buflen;
+	h->length = *buflen;
 	ctdb_req_header_push(h, (uint8_t *)&wire->hdr);
 
 	wire->srvid = message->srvid;
@@ -350,18 +351,19 @@ size_t ctdb_req_message_data_len(struct ctdb_req_header *h,
 
 int ctdb_req_message_data_push(struct ctdb_req_header *h,
 			       struct ctdb_req_message_data *message,
-			       uint8_t *buf, size_t buflen)
+			       uint8_t *buf, size_t *buflen)
 {
 	struct ctdb_req_message_wire *wire =
 		(struct ctdb_req_message_wire *)buf;
 	size_t length;
 
 	length = ctdb_req_message_data_len(h, message);
-	if (buflen < length) {
+	if (*buflen < length) {
+		*buflen = length;
 		return EMSGSIZE;
 	}
 
-	h->length = buflen;
+	h->length = *buflen;
 	ctdb_req_header_push(h, (uint8_t *)&wire->hdr);
 
 	wire->srvid = message->srvid;
diff --git a/ctdb/tests/src/protocol_client_test.c b/ctdb/tests/src/protocol_client_test.c
index c03ad3bdac2..16ec8452ea2 100644
--- a/ctdb/tests/src/protocol_client_test.c
+++ b/ctdb/tests/src/protocol_client_test.c
@@ -1977,7 +1977,7 @@ static void test_req_call_test(void)
 {
 	TALLOC_CTX *mem_ctx;
 	uint8_t *pkt;
-	size_t datalen, pkt_len;
+	size_t datalen, pkt_len, len;
 	int ret;
 	struct ctdb_req_header h, h2;
 	struct ctdb_req_call c, c2;
@@ -1997,7 +1997,11 @@ static void test_req_call_test(void)
 	assert(ret == 0);
 	assert(pkt != NULL);
 	assert(pkt_len >= datalen);
-	ret = ctdb_req_call_push(&h, &c, pkt, pkt_len);
+	len = 0;
+	ret = ctdb_req_call_push(&h, &c, pkt, &len);
+	assert(ret == EMSGSIZE);
+	assert(len == datalen);
+	ret = ctdb_req_call_push(&h, &c, pkt, &pkt_len);
 	assert(ret == 0);
 	ret = ctdb_req_call_pull(pkt, pkt_len, &h2, mem_ctx, &c2);
 	assert(ret == 0);
@@ -2012,7 +2016,7 @@ static void test_reply_call_test(void)
 {
 	TALLOC_CTX *mem_ctx;
 	uint8_t *pkt;
-	size_t datalen, pkt_len;
+	size_t datalen, pkt_len, len;
 	int ret;
 	struct ctdb_req_header h, h2;
 	struct ctdb_reply_call c, c2;
@@ -2032,7 +2036,11 @@ static void test_reply_call_test(void)
 	assert(ret == 0);
 	assert(pkt != NULL);
 	assert(pkt_len >= datalen);
-	ret = ctdb_reply_call_push(&h, &c, pkt, pkt_len);
+	len = 0;
+	ret = ctdb_reply_call_push(&h, &c, pkt, &len);
+	assert(ret == EMSGSIZE);
+	assert(len == datalen);
+	ret = ctdb_reply_call_push(&h, &c, pkt, &pkt_len);
 	assert(ret == 0);
 	ret = ctdb_reply_call_pull(pkt, pkt_len, &h2, mem_ctx, &c2);
 	assert(ret == 0);
@@ -2047,7 +2055,7 @@ static void test_reply_error_test(void)
 {
 	TALLOC_CTX *mem_ctx;
 	uint8_t *pkt;
-	size_t datalen, pkt_len;
+	size_t datalen, pkt_len, len;
 	int ret;
 	struct ctdb_req_header h, h2;
 	struct ctdb_reply_error c, c2;
@@ -2067,7 +2075,11 @@ static void test_reply_error_test(void)
 	assert(ret == 0);
 	assert(pkt != NULL);
 	assert(pkt_len >= datalen);
-	ret = ctdb_reply_error_push(&h, &c, pkt, pkt_len);
+	len = 0;
+	ret = ctdb_reply_error_push(&h, &c, pkt, &len);
+	assert(ret == EMSGSIZE);
+	assert(len == datalen);
+	ret = ctdb_reply_error_push(&h, &c, pkt, &pkt_len);
 	assert(ret == 0);
 	ret = ctdb_reply_error_pull(pkt, pkt_len, &h2, mem_ctx, &c2);
 	assert(ret == 0);
@@ -2082,7 +2094,7 @@ static void test_req_dmaster_test(void)
 {
 	TALLOC_CTX *mem_ctx;
 	uint8_t *pkt;
-	size_t datalen, pkt_len;
+	size_t datalen, pkt_len, len;
 	int ret;
 	struct ctdb_req_header h, h2;
 	struct ctdb_req_dmaster c, c2;
@@ -2102,7 +2114,11 @@ static void test_req_dmaster_test(void)
 	assert(ret == 0);
 	assert(pkt != NULL);
 	assert(pkt_len >= datalen);
-	ret = ctdb_req_dmaster_push(&h, &c, pkt, pkt_len);
+	len = 0;
+	ret = ctdb_req_dmaster_push(&h, &c, pkt, &len);
+	assert(ret == EMSGSIZE);
+	assert(len == datalen);
+	ret = ctdb_req_dmaster_push(&h, &c, pkt, &pkt_len);
 	assert(ret == 0);
 	ret = ctdb_req_dmaster_pull(pkt, pkt_len, &h2, mem_ctx, &c2);
 	assert(ret == 0);
@@ -2117,7 +2133,7 @@ static void test_reply_dmaster_test(void)
 {
 	TALLOC_CTX *mem_ctx;
 	uint8_t *pkt;
-	size_t datalen, pkt_len;
+	size_t datalen, pkt_len, len;
 	int ret;
 	struct ctdb_req_header h, h2;
 	struct ctdb_reply_dmaster c, c2;
@@ -2137,7 +2153,11 @@ static void test_reply_dmaster_test(void)
 	assert(ret == 0);
 	assert(pkt != NULL);
 	assert(pkt_len >= datalen);
-	ret = ctdb_reply_dmaster_push(&h, &c, pkt, pkt_len);
+	len = 0;
+	ret = ctdb_reply_dmaster_push(&h, &c, pkt, &len);
+	assert(ret == EMSGSIZE);
+	assert(len == datalen);
+	ret = ctdb_reply_dmaster_push(&h, &c, pkt, &pkt_len);
 	assert(ret == 0);
 	ret = ctdb_reply_dmaster_pull(pkt, pkt_len, &h2, mem_ctx, &c2);
 	assert(ret == 0);
@@ -2214,7 +2234,7 @@ static void test_req_control_test(void)
 {
 	TALLOC_CTX *mem_ctx;
 	uint8_t *pkt;
-	size_t datalen, pkt_len;
+	size_t datalen, pkt_len, len;
 	int ret;
 	struct ctdb_req_header h, h2;
 	struct ctdb_req_control c, c2;
@@ -2238,7 +2258,11 @@ static void test_req_control_test(void)
 		assert(ret == 0);
 		assert(pkt != NULL);
 		assert(pkt_len >= datalen);
-		ret = ctdb_req_control_push(&h, &c, pkt, pkt_len);
+		len = 0;
+		ret = ctdb_req_control_push(&h, &c, pkt, &len);
+		assert(ret == EMSGSIZE);
+		assert(len == datalen);
+		ret = ctdb_req_control_push(&h, &c, pkt, &pkt_len);
 		assert(ret == 0);
 		ret = ctdb_req_control_pull(pkt, pkt_len, &h2, mem_ctx, &c2);
 		assert(ret == 0);
@@ -2257,7 +2281,7 @@ static void test_reply_control_test(void)
 {
 	TALLOC_CTX *mem_ctx;
 	uint8_t *pkt;
-	size_t datalen, pkt_len;
+	size_t datalen, pkt_len, len;
 	int ret;
 	struct ctdb_req_header h, h2;
 	struct ctdb_reply_control c, c2;
@@ -2281,7 +2305,11 @@ static void test_reply_control_test(void)
 		assert(ret == 0);
 		assert(pkt != NULL);
 		assert(pkt_len >= datalen);
-		ret = ctdb_reply_control_push(&h, &c, pkt, pkt_len);
+		len = 0;
+		ret = ctdb_reply_control_push(&h, &c, pkt, &len);
+		assert(ret == EMSGSIZE);
+		assert(len == datalen);
+		ret = ctdb_reply_control_push(&h, &c, pkt, &pkt_len);
 		assert(ret == 0);
 		ret = ctdb_reply_control_pull(pkt, pkt_len, opcode, &h2, mem_ctx, &c2);
 		assert(ret == 0);
@@ -2300,7 +2328,7 @@ static void test_req_message_test(void)
 {
 	TALLOC_CTX *mem_ctx;
 	uint8_t *pkt;
-	size_t datalen, pkt_len;
+	size_t datalen, pkt_len, len;
 	int ret;
 	struct ctdb_req_header h, h2;
 	struct ctdb_req_message_data c, c2;
@@ -2320,7 +2348,11 @@ static void test_req_message_test(void)
 	assert(ret == 0);
 	assert(pkt != NULL);
 	assert(pkt_len >= datalen);
-	ret = ctdb_req_message_data_push(&h, &c, pkt, pkt_len);
+	len = 0;
+	ret = ctdb_req_message_data_push(&h, &c, pkt, &len);
+	assert(ret == EMSGSIZE);
+	assert(len == datalen);
+	ret = ctdb_req_message_data_push(&h, &c, pkt, &pkt_len);
 	assert(ret == 0);
 	ret = ctdb_req_message_data_pull(pkt, pkt_len, &h2, mem_ctx, &c2);
 	assert(ret == 0);