oob/tcp: add cross version compatibility support

Since we intend to provide cross version compatibility
between versions with the same major and minor, use
MAJOR.MINOR.0 instead of orte_version_string
(e.g. MAJOR.MINOR.RELEASEGREEK).

Open MPI 4.0.0 has already been released, so in order to make
it compatible with future 4.0.x releases, we have to use 4.0.0
as the version string, that is why we use MAJOR.MINOR.0 instead
of MAJOR.MINOR

Signed-off-by: Gilles Gouaillardet <gilles@rist.or.jp>

orte/mca/oob/tcp/oob_tcp_connection.c

@@ -14,8 +14,8 @@
  * Copyright (c) 2009-2018 Cisco Systems, Inc.  All rights reserved
  * Copyright (c) 2011      Oak Ridge National Labs.  All rights reserved.
  * Copyright (c) 2013-2017 Intel, Inc.  All rights reserved.
- * Copyright (c) 2014-2015 Research Organization for Information Science
- *                         and Technology (RIST). All rights reserved.
+ * Copyright (c) 2014-2018 Research Organization for Information Science
+ *                         and Technology (RIST).  All rights reserved.
  * Copyright (c) 2016      Mellanox Technologies Ltd. All rights reserved.
  * $COPYRIGHT$
  *
@@ -83,6 +83,11 @@
 #include "oob_tcp_common.h"
 #include "oob_tcp_connection.h"
 
+#define OOB_TCP_STR_EXPAND(tok) #tok
+#define OOB_TCP_STR(tok) OOB_TCP_STR_EXPAND(tok)
+
+static char * oob_tcp_version_string = OOB_TCP_STR(ORTE_MAJOR_VERSION) "." OOB_TCP_STR(ORTE_MINOR_VERSION) ".0";
+
 static void tcp_peer_event_init(mca_oob_tcp_peer_t* peer);
 static int  tcp_peer_send_connect_ack(mca_oob_tcp_peer_t* peer);
 static int tcp_peer_send_connect_nack(int sd, orte_process_name_t name);
@@ -417,7 +422,7 @@ static int tcp_peer_send_connect_ack(mca_oob_tcp_peer_t* peer)
     memset(hdr.routed, 0, ORTE_MAX_RTD_SIZE+1);
 
     /* payload size */
-    sdsize = sizeof(ack_flag) + strlen(orte_version_string) + 1;
+    sdsize = sizeof(ack_flag) + strlen(oob_tcp_version_string) + 1;
     hdr.nbytes = sdsize;
     MCA_OOB_TCP_HDR_HTON(&hdr);
 
@@ -433,8 +438,8 @@ static int tcp_peer_send_connect_ack(mca_oob_tcp_peer_t* peer)
     offset += sizeof(hdr);
     memcpy(msg + offset, &ack_flag, sizeof(ack_flag));
     offset += sizeof(ack_flag);
-    memcpy(msg + offset, orte_version_string, strlen(orte_version_string));
-    offset += strlen(orte_version_string)+1;
+    memcpy(msg + offset, oob_tcp_version_string, strlen(oob_tcp_version_string));
+    offset += strlen(oob_tcp_version_string)+1;
 
     /* send it */
     if (ORTE_SUCCESS != tcp_peer_send_blocking(peer->sd, msg, sdsize)) {
@@ -905,12 +910,12 @@ int mca_oob_tcp_peer_recv_connect_ack(mca_oob_tcp_peer_t* pr,
     /* check that this is from a matching version */
     version = (char*)((char*)msg + offset);
     offset += strlen(version) + 1;
-    if (0 != strcmp(version, orte_version_string)) {
+    if (0 != strcmp(version, oob_tcp_version_string)) {
         opal_show_help("help-oob-tcp.txt", "version mismatch",
                        true,
                        opal_process_info.nodename,
                        ORTE_NAME_PRINT(ORTE_PROC_MY_NAME),
-                       orte_version_string,
+                       oob_tcp_version_string,
                        opal_fd_get_peer_name(peer->sd),
                        ORTE_NAME_PRINT(&(peer->name)),
                        version);