Fix: Relayd and sessiond version check

[lttng-tools.git] / src / bin / lttng-relayd / main.c

diff --git a/src/bin/lttng-relayd/main.c b/src/bin/lttng-relayd/main.c
index a00fb3c48ab258459de880d3a4720ef9dfd9b0ed..bd19a323715309697ba3b3ff61c6d29a615ad379 100644 (file)
--- a/src/bin/lttng-relayd/main.c
+++ b/src/bin/lttng-relayd/main.c
@@ -1281,7 +1281,7 @@ int relay_send_version(struct lttcomm_relayd_hdr *recv_hdr,
                struct relay_command *cmd)
 {
        int ret;
-       struct lttcomm_relayd_version reply;
+       struct lttcomm_relayd_version reply, msg;
        struct relay_session *session;
 
        if (cmd->session == NULL) {
@@ -1299,6 +1299,21 @@ int relay_send_version(struct lttcomm_relayd_hdr *recv_hdr,
        }
        session->version_check_done = 1;
 
+       /* Get version from the other side. */
+       ret = cmd->sock->ops->recvmsg(cmd->sock, &msg, sizeof(msg), MSG_WAITALL);
+       if (ret < 0 || ret != sizeof(msg)) {
+               ret = -1;
+               ERR("Relay failed to receive the version values.");
+               goto end;
+       }
+
+       /*
+        * For now, we just ignore the received version but after 2.1 stable
+        * release, a check must be done to see if we either adapt to the other
+        * side version (which MUST be lower than us) or keep the latest data
+        * structure considering that the other side will adapt.
+        */
+
        ret = sscanf(VERSION, "%u.%u", &reply.major, &reply.minor);
        if (ret < 2) {
                ERR("Error in scanning version");