Fix: channel and stream leak in consumerd

[lttng-tools.git] / src / common / ust-consumer / ust-consumer.c

diff --git a/src/common/ust-consumer/ust-consumer.c b/src/common/ust-consumer/ust-consumer.c
index 780a601f67e74b70b3632a6d489067d82e1359ef..f783d4058c550033983045c93cbeddcc363028d3 100644 (file)
--- a/src/common/ust-consumer/ust-consumer.c
+++ b/src/common/ust-consumer/ust-consumer.c
@@ -394,7 +394,7 @@ static int send_sessiond_channel(int sock,
                struct lttng_consumer_channel *channel,
                struct lttng_consumer_local_data *ctx, int *relayd_error)
 {
-       int ret;
+       int ret, ret_code = LTTNG_OK;
        struct lttng_consumer_stream *stream;
 
        assert(channel);
@@ -403,18 +403,6 @@ static int send_sessiond_channel(int sock,
 
        DBG("UST consumer sending channel %s to sessiond", channel->name);
 
-       /* Send channel to sessiond. */
-       ret = ustctl_send_channel_to_sessiond(sock, channel->uchan);
-       if (ret < 0) {
-               goto error;
-       }
-
-       ret = ustctl_channel_close_wakeup_fd(channel->uchan);
-       if (ret < 0) {
-               goto error;
-       }
-
-       /* The channel was sent successfully to the sessiond at this point. */
        cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
                /* Try to send the stream to the relayd if one is available. */
                ret = send_stream_to_relayd(stream);
@@ -426,9 +414,33 @@ static int send_sessiond_channel(int sock,
                        if (relayd_error) {
                                *relayd_error = 1;
                        }
-                       goto error;
+                       ret_code = LTTNG_ERR_RELAYD_CONNECT_FAIL;
                }
+       }
 
+       /* Inform sessiond that we are about to send channel and streams. */
+       ret = consumer_send_status_msg(sock, ret_code);
+       if (ret < 0 || ret_code != LTTNG_OK) {
+               /*
+                * Either the session daemon is not responding or the relayd died so we
+                * stop now.
+                */
+               goto error;
+       }
+
+       /* Send channel to sessiond. */
+       ret = ustctl_send_channel_to_sessiond(sock, channel->uchan);
+       if (ret < 0) {
+               goto error;
+       }
+
+       ret = ustctl_channel_close_wakeup_fd(channel->uchan);
+       if (ret < 0) {
+               goto error;
+       }
+
+       /* The channel was sent successfully to the sessiond at this point. */
+       cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
                /* Send stream to session daemon. */
                ret = send_sessiond_stream(sock, stream);
                if (ret < 0) {
@@ -447,6 +459,9 @@ static int send_sessiond_channel(int sock,
        return 0;
 
 error:
+       if (ret_code != LTTNG_OK) {
+               ret = -1;
+       }
        return ret;
 }
 
@@ -677,7 +692,7 @@ static int setup_metadata(struct lttng_consumer_local_data *ctx, uint64_t key)
        if (!metadata) {
                ERR("UST consumer push metadata %" PRIu64 " not found", key);
                ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
-               goto error;
+               goto error_find;
        }
 
        /*
@@ -709,9 +724,17 @@ static int setup_metadata(struct lttng_consumer_local_data *ctx, uint64_t key)
        /* List MUST be empty after or else it could be reused. */
        assert(cds_list_empty(&metadata->streams.head));
 
-       ret = 0;
+       return 0;
 
 error:
+       /*
+        * Delete metadata channel on error. At this point, the metadata stream can
+        * NOT be monitored by the metadata thread thus having the guarantee that
+        * the stream is still in the local stream list of the channel. This call
+        * will make sure to clean that list.
+        */
+       consumer_del_channel(metadata);
+error_find:
        return ret;
 }
 
@@ -1007,13 +1030,6 @@ int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
                        goto end_msg_sessiond;
                }
 
-               /* Inform sessiond that we are about to send channel and streams. */
-               ret = consumer_send_status_msg(sock, LTTNG_OK);
-               if (ret < 0) {
-                       /* Somehow, the session daemon is not responding anymore. */
-                       goto error_fatal;
-               }
-
                /* Send everything to sessiond. */
                ret = send_sessiond_channel(sock, channel, ctx, &relayd_err);
                if (ret < 0) {
@@ -1021,10 +1037,10 @@ int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
                                /*
                                 * We were unable to send to the relayd the stream so avoid
                                 * sending back a fatal error to the thread since this is OK
-                                * and the consumer can continue its work.
+                                * and the consumer can continue its work. The above call
+                                * has sent the error status message to the sessiond.
                                 */
-                               ret_code = LTTNG_ERR_RELAYD_CONNECT_FAIL;
-                               goto end_msg_sessiond;
+                               goto end_nosignal;
                        }
                        /*
                         * The communicaton was broken hence there is a bad state between
@@ -1544,7 +1560,13 @@ int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data *ctx,
 
        ret_code = lttng_ustconsumer_recv_metadata(ctx->consumer_metadata_socket,
                        key, offset, len, channel);
-       (void) consumer_send_status_msg(ctx->consumer_metadata_socket, ret_code);
+       if (ret_code >= 0) {
+               /*
+                * Only send the status msg if the sessiond is alive meaning a positive
+                * ret code.
+                */
+               (void) consumer_send_status_msg(ctx->consumer_metadata_socket, ret_code);
+       }
        ret = 0;
 
 end: