Correctly check the sa_family and cast the data correctly before passing it to inet_nop, and don't be quite as fancy with the pointer arithmetic as the combination was causing us to segfault every time this debug message was called.

Signed-off-by: Ralph Castain <rhc@open-mpi.org>

opal/mca/btl/tcp/btl_tcp_proc.c

@@ -11,7 +11,7 @@
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
  * Copyright (c) 2008-2010 Oracle and/or its affiliates.  All rights reserved
- * Copyright (c) 2013-2015 Intel, Inc. All rights reserved
+ * Copyright (c) 2013-2017 Intel, Inc.  All rights reserved.
  * Copyright (c) 2014-2016 Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
  * Copyright (c) 2015-2016 Los Alamos National Security, LLC. All rights
@@ -828,24 +828,27 @@ void mca_btl_tcp_proc_accept(mca_btl_tcp_proc_t* btl_proc, struct sockaddr* addr
     /* No further use of this socket. Close it */
     CLOSE_THE_SOCKET(sd);
     {
-        size_t len = 1024;
-        char* addr_str = (char*)malloc(len);
-        if( NULL != addr_str ) {
-            memset(addr_str, 0, len);
-            for (size_t i = 0; i < btl_proc->proc_endpoint_count; i++) {
-                mca_btl_base_endpoint_t* btl_endpoint = btl_proc->proc_endpoints[i];
-                if (btl_endpoint->endpoint_addr->addr_family != addr->sa_family) {
-                    continue;
-                }
-
-                if (addr_str[0] != '\0') {
-                    strncat(addr_str, ", ", len);
-                    len -= 2;
-                }
-                strncat(addr_str, inet_ntop(AF_INET6, (void*)(struct in6_addr*)&btl_endpoint->endpoint_addr->addr_inet,
-                                            addr_str + 1024 - len, INET6_ADDRSTRLEN), len);
-                len = 1024 - strlen(addr_str);
+        char *addr_str=NULL, *tmp, pnet[1024];
+        for (size_t i = 0; i < btl_proc->proc_endpoint_count; i++) {
+            mca_btl_base_endpoint_t* btl_endpoint = btl_proc->proc_endpoints[i];
+            if (btl_endpoint->endpoint_addr->addr_family != addr->sa_family) {
+                continue;
             }
+            if (AF_INET == addr->sa_family) {
+                inet_ntop(AF_INET, (void*)(struct in_addr*)&btl_endpoint->endpoint_addr->addr_inet, pnet, 1024);
+            } else if (AF_INET6 == addr->sa_family) {
+                inet_ntop(AF_INET6, (void*)(struct in6_addr*)&btl_endpoint->endpoint_addr->addr_inet, pnet, 1024);
+            } else {
+                /* unrecognized family */
+                continue;
+            }
+            if (NULL == addr_str) {
+                (void)asprintf(&tmp, "\n\t%s", pnet);
+            } else {
+                (void)asprintf(&tmp, "%s\n\t%s", addr_str, pnet);
+                free(addr_str);
+            }
+            addr_str = tmp;
         }
         opal_show_help("help-mpi-btl-tcp.txt", "dropped inbound connection",
                        true, opal_process_info.nodename,
@@ -853,8 +856,10 @@ void mca_btl_tcp_proc_accept(mca_btl_tcp_proc_t* btl_proc, struct sockaddr* addr
                        btl_proc->proc_opal->proc_hostname,
                        OPAL_NAME_PRINT(btl_proc->proc_opal->proc_name),
                        opal_net_get_hostname((struct sockaddr*)addr),
-                       addr_str);
-        free(addr_str);
+                       (NULL == addr_str) ? "NONE" : addr_str);
+        if (NULL != addr_str) {
+            free(addr_str);
+        }
     }
     OPAL_THREAD_UNLOCK(&btl_proc->proc_lock);
 }