From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Wed, 25 Jul 2012 21:39:12 +0000 (-0400)
Subject: Fix: relayd metadata size
X-Git-Tag: v2.1.0-rc1~44
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=f64161251bd649abe5b6a473531adfa3af9bd6b6;p=lttng-tools.git

Fix: relayd metadata size

Trying to see better how the metadata size was handled, I ended up doing
a couple of modifications to the size value sent by the sender: given
that this header contains a size value that should cover both the
metadata packet header size, and the following payload size (this is how
kernel splice sent behaves), I modified kernel/UST mmap to do the same.

I therefore changed the recently updated recv_metadata payload size
calculation to match the encoded size, which should hopefully work for
all kernel splice/mmap and UST mmap cases.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: David Goulet <dgoulet@efficios.com>
---

diff --git a/src/bin/lttng-relayd/main.c b/src/bin/lttng-relayd/main.c
index f0663d10d..1ef6881c0 100644
--- a/src/bin/lttng-relayd/main.c
+++ b/src/bin/lttng-relayd/main.c
@@ -1070,13 +1070,14 @@ int relay_recv_metadata(struct lttcomm_relayd_hdr *recv_hdr,
 		goto end;
 	}
 
-	data_size = be64toh(recv_hdr->data_size);
-	payload_size = data_size;
-	/*
-	 * Add 8 bytes (uint64_t) to the data size which is the value of the
-	 * stream_id and the payload size.
-	 */
-	data_size +=  sizeof(uint64_t);
+	data_size = payload_size = be64toh(recv_hdr->data_size);
+	if (data_size < sizeof(struct lttcomm_relayd_metadata_payload)) {
+		ERR("Incorrect data size");
+		ret = -1;
+		goto end;
+	}
+	payload_size -= sizeof(struct lttcomm_relayd_metadata_payload);
+
 	if (data_buffer_size < data_size) {
 		data_buffer = realloc(data_buffer, data_size);
 		if (!data_buffer) {
diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c
index 551d8579a..22bf10020 100644
--- a/src/common/kernel-consumer/kernel-consumer.c
+++ b/src/common/kernel-consumer/kernel-consumer.c
@@ -81,6 +81,8 @@ ssize_t lttng_kconsumer_on_read_subbuffer_mmap(
 
 	/* Handle stream on the relayd if the output is on the network */
 	if (relayd) {
+		unsigned long netlen = len;
+
 		/*
 		 * Lock the control socket for the complete duration of the function
 		 * since from this point on we will use the socket.
@@ -88,9 +90,10 @@ ssize_t lttng_kconsumer_on_read_subbuffer_mmap(
 		if (stream->metadata_flag) {
 			/* Metadata requires the control socket. */
 			pthread_mutex_lock(&relayd->ctrl_sock_mutex);
+			netlen += sizeof(stream->relayd_stream_id);
 		}
 
-		ret = consumer_handle_stream_before_relayd(stream, len);
+		ret = consumer_handle_stream_before_relayd(stream, netlen);
 		if (ret >= 0) {
 			/* Use the returned socket. */
 			outfd = ret;
diff --git a/src/common/ust-consumer/ust-consumer.c b/src/common/ust-consumer/ust-consumer.c
index a57bf1598..7ce03ad87 100644
--- a/src/common/ust-consumer/ust-consumer.c
+++ b/src/common/ust-consumer/ust-consumer.c
@@ -81,12 +81,15 @@ ssize_t lttng_ustconsumer_on_read_subbuffer_mmap(
 
 	/* Handle stream on the relayd if the output is on the network */
 	if (relayd) {
+		unsigned long netlen = len;
+
 		if (stream->metadata_flag) {
 			/* Only lock if metadata since we use the control socket. */
 			pthread_mutex_lock(&relayd->ctrl_sock_mutex);
+			netlen += sizeof(stream->relayd_stream_id);
 		}
 
-		ret = consumer_handle_stream_before_relayd(stream, len);
+		ret = consumer_handle_stream_before_relayd(stream, netlen);
 		if (ret >= 0) {
 			outfd = ret;