From: David Goulet <dgoulet@efficios.com>
Date: Wed, 19 Dec 2012 22:51:25 +0000 (-0500)
Subject: Fix: handle shutdown on recv reply in relayd
X-Git-Tag: v2.1.0~14
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=20275fe8f99ff582686a0defbd88de971c98450c;p=lttng-tools.git

Fix: handle shutdown on recv reply in relayd

Print a meaningful error when the recvmsg for the reply gets an orderly
shutdown or an error.

Return a negative value each time since this means that we have to stop
everything for that socket and clean up.

Signed-off-by: David Goulet <dgoulet@efficios.com>
---

diff --git a/src/common/relayd/relayd.c b/src/common/relayd/relayd.c
index c883ea5d7..63a55c227 100644
--- a/src/common/relayd/relayd.c
+++ b/src/common/relayd/relayd.c
@@ -90,8 +90,16 @@ static int recv_reply(struct lttcomm_sock *sock, void *data, size_t size)
 	DBG3("Relayd waiting for reply of size %ld", size);
 
 	ret = sock->ops->recvmsg(sock, data, size, 0);
-	if (ret < 0) {
-		ret = -errno;
+	if (ret <= 0 || ret != size) {
+		if (ret == 0) {
+			/* Orderly shutdown. */
+			DBG("Socket %d has performed an orderly shutdown", sock->fd);
+		} else {
+			DBG("Receiving reply failed on sock %d for size %lu with ret %d",
+					sock->fd, size, ret);
+		}
+		/* Always return -1 here and the caller can use errno. */
+		ret = -1;
 		goto error;
 	}
 
@@ -103,8 +111,8 @@ error:
  * Send a RELAYD_CREATE_SESSION command to the relayd with the given socket and
  * set session_id of the relayd if we have a successful reply from the relayd.
  *
- * On success, return 0 else a negative value being a lttng_error_code returned
- * from the relayd.
+ * On success, return 0 else a negative value which is either an errno error or
+ * a lttng error code from the relayd.
  */
 int relayd_create_session(struct lttcomm_sock *sock, uint64_t *session_id)
 {
@@ -122,7 +130,7 @@ int relayd_create_session(struct lttcomm_sock *sock, uint64_t *session_id)
 		goto error;
 	}
 
-	/* Recevie response */
+	/* Receive response */
 	ret = recv_reply(sock, (void *) &reply, sizeof(reply));
 	if (ret < 0) {
 		goto error;
@@ -228,7 +236,7 @@ int relayd_version_check(struct lttcomm_sock *sock, uint32_t major,
 		goto error;
 	}
 
-	/* Recevie response */
+	/* Receive response */
 	ret = recv_reply(sock, (void *) &msg, sizeof(msg));
 	if (ret < 0) {
 		goto error;
@@ -389,7 +397,7 @@ int relayd_send_close_stream(struct lttcomm_sock *sock, uint64_t stream_id,
 		goto error;
 	}
 
-	/* Recevie response */
+	/* Receive response */
 	ret = recv_reply(sock, (void *) &reply, sizeof(reply));
 	if (ret < 0) {
 		goto error;
@@ -439,7 +447,7 @@ int relayd_data_pending(struct lttcomm_sock *sock, uint64_t stream_id,
 		goto error;
 	}
 
-	/* Recevie response */
+	/* Receive response */
 	ret = recv_reply(sock, (void *) &reply, sizeof(reply));
 	if (ret < 0) {
 		goto error;
@@ -485,7 +493,7 @@ int relayd_quiescent_control(struct lttcomm_sock *sock,
 		goto error;
 	}
 
-	/* Recevie response */
+	/* Receive response */
 	ret = recv_reply(sock, (void *) &reply, sizeof(reply));
 	if (ret < 0) {
 		goto error;
@@ -529,7 +537,7 @@ int relayd_begin_data_pending(struct lttcomm_sock *sock, uint64_t id)
 		goto error;
 	}
 
-	/* Recevie response */
+	/* Receive response */
 	ret = recv_reply(sock, (void *) &reply, sizeof(reply));
 	if (ret < 0) {
 		goto error;
@@ -576,7 +584,7 @@ int relayd_end_data_pending(struct lttcomm_sock *sock, uint64_t id,
 		goto error;
 	}
 
-	/* Recevie response */
+	/* Receive response */
 	ret = recv_reply(sock, (void *) &reply, sizeof(reply));
 	if (ret < 0) {
 		goto error;