From: David Goulet <dgoulet@efficios.com>
Date: Wed, 25 Jul 2012 20:59:30 +0000 (-0400)
Subject: Fix: Off by uint64_t in the metadata transfer
X-Git-Tag: v2.1.0-rc1~46
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=87c1611dab332f28b4b72c6ed96cb2a2ef31d5f7;ds=sidebyside

Fix: Off by uint64_t in the metadata transfer

This patch also adds a couple of debug output along with this fix.

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 abefba865..f0663d10d 100644
--- a/src/bin/lttng-relayd/main.c
+++ b/src/bin/lttng-relayd/main.c
@@ -1071,7 +1071,12 @@ int relay_recv_metadata(struct lttcomm_relayd_hdr *recv_hdr,
 	}
 
 	data_size = be64toh(recv_hdr->data_size);
-	payload_size = data_size - sizeof(uint64_t);
+	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);
 	if (data_buffer_size < data_size) {
 		data_buffer = realloc(data_buffer, data_size);
 		if (!data_buffer) {
@@ -1083,7 +1088,8 @@ int relay_recv_metadata(struct lttcomm_relayd_hdr *recv_hdr,
 	}
 	memset(data_buffer, 0, data_size);
 	DBG2("Relay receiving metadata, waiting for %lu bytes", data_size);
-	ret = cmd->sock->ops->recvmsg(cmd->sock, data_buffer, data_size, MSG_WAITALL);
+	ret = cmd->sock->ops->recvmsg(cmd->sock, data_buffer, data_size,
+			MSG_WAITALL);
 	if (ret < 0 || ret != data_size) {
 		ret = -1;
 		ERR("Relay didn't receive the whole metadata");
@@ -1103,7 +1109,7 @@ int relay_recv_metadata(struct lttcomm_relayd_hdr *recv_hdr,
 		ret = write(metadata_stream->fd, metadata_struct->payload,
 				payload_size);
 	} while (ret < 0 && errno == EINTR);
-	if (ret < (payload_size)) {
+	if (ret < payload_size) {
 		ERR("Relay error writing metadata on file");
 		ret = -1;
 		goto end_unlock;
@@ -1234,6 +1240,7 @@ int relay_process_data(struct relay_command *cmd, struct lttng_ht *streams_ht)
 	}
 	memset(data_buffer, 0, data_size);
 
+	DBG3("Receiving data of size %u for stream id %zu", data_size, stream_id);
 	ret = cmd->sock->ops->recvmsg(cmd->sock, data_buffer, data_size, MSG_WAITALL);
 	if (ret <= 0) {
 		ret = -1;
@@ -1377,6 +1384,7 @@ void *relay_thread_worker(void *data)
 
 		/* Infinite blocking call, waiting for transmission */
 	restart:
+		DBG3("Relayd worker thread polling...");
 		ret = lttng_poll_wait(&events, -1);
 		if (ret < 0) {
 			/*
diff --git a/src/common/ust-consumer/ust-consumer.c b/src/common/ust-consumer/ust-consumer.c
index 4cd697212..a57bf1598 100644
--- a/src/common/ust-consumer/ust-consumer.c
+++ b/src/common/ust-consumer/ust-consumer.c
@@ -63,7 +63,8 @@ ssize_t lttng_ustconsumer_on_read_subbuffer_mmap(
 	if (stream->net_seq_idx != -1) {
 		relayd = consumer_find_relayd(stream->net_seq_idx);
 		if (relayd == NULL) {
-			ERR("Cannot find relay for network stream\n");
+			ERR("UST consumer mmap(), unable to find relay for index %d",
+					stream->net_seq_idx);
 			goto end;
 		}
 	}