This commit looks much bigger than it is. There are only 2

substantive changes in this commit; the rest are minor style changes:

 1. Change an OBJ_NEW(opal_list_item_t) to OBJ_NEW(opal_if_t).  This
    was causing memory corruption in the BSD code paths.
 1. Move some local variables from the top of opal_if_init() to inside
    the non-BSD code paths so that we avoid bunches of warnings about
    unused variables when compiling on BSD.  In doing so, I indented
    the whole non-BSD section one level deeper, making the commit look
    huge. 

I also added a few {} around 1-line blocks, added some spaces, broke a
few lines, re-formatted a few comments, ...etc.  Trivial stuff.

This commit was SVN r23501.

opal/util/if.c

@@ -147,13 +147,7 @@ static int prefix (uint32_t netmask)
 static int opal_ifinit(void) 
 {
 #ifndef __WINDOWS__
-
+    int flag;
-    int sd;
-    int lastlen, num, rem;
-    char *ptr;
-    struct ifconf ifconf;
-    int ifc_len;
-    bool successful_locate = false;
 
     if (already_done) {
         return OPAL_SUCCESS;
@@ -162,8 +156,8 @@ static int opal_ifinit(void)
 
     mca_base_param_reg_int_name("opal", "if_do_not_resolve",
                                 "If nonzero, do not attempt to resolve interfaces",
-                                false, false, (int)false, &sd);
+                                false, false, (int)false, &flag);
-    do_not_resolve = OPAL_INT_TO_BOOL(sd);
+    do_not_resolve = OPAL_INT_TO_BOOL(flag);
 
     OBJ_CONSTRUCT(&opal_if_list, opal_list_t);
 
@@ -214,7 +208,7 @@ static int opal_ifinit(void)
 
             sin_addr = (struct sockaddr_in *) cur_ifaddrs->ifa_addr;
 
-            intf = OBJ_NEW(opal_list_item_t);
+            intf = OBJ_NEW(opal_if_t);
             if (NULL == intf) {
                 opal_output(0, "opal_ifinit: unable to allocate %lu bytes\n",
                             sizeof(opal_if_t));
@@ -230,43 +224,32 @@ static int opal_ifinit(void)
             ((struct sockaddr_in*) &intf->if_addr)->sin_family = AF_INET;
             ((struct sockaddr_in*) &intf->if_addr)->sin_len =  cur_ifaddrs->ifa_addr->sa_len;
 
-            /* since every scope != 0 is ignored, we just set the scope to 0 */
-            /* There's no scope_id in the non-ipv6 stuff 
-	    ((struct sockaddr_in6*) &intf->if_addr)->sin6_scope_id = 0; 
-	    */
-
-            /*
-             * hardcoded netmask, adrian says that's ok
-             */
-	    /* Non-NetBSD uses intf->if_mask = prefix(((struct sockaddr_in*) &ifr->ifr_addr)->sin_addr.s_addr); */
-            /* intf->if_mask = 64; */
 	    intf->if_mask = prefix( sin_addr->sin_addr.s_addr);
             intf->if_flags = cur_ifaddrs->ifa_flags;
 
-            /*
-             * FIXME: figure out how to gain access to the kernel index
-             * (or create our own), getifaddrs() does not contain such
-             * data
-             */
             intf->if_kernel_index = 
                 (uint16_t) if_nametoindex(cur_ifaddrs->ifa_name);
 
             opal_list_append(&opal_if_list, &(intf->super));
         }   /*  of for loop over ifaddrs list */
-
     }
+    /* End of various flavors of BSD */
 #else
-    /* create the internet socket to test off */
+    /* Beginning of !(various flavors of BSD) */
-/*
+    {
-   Change AF_INET to AF_UNSPEC (or AF_INET6) and everything will fail.
+        int sd;
+        int lastlen, num, rem;
+        char *ptr;
+        struct ifconf ifconf;
+        int ifc_len;
+        bool successful_locate = false;
 
-   Note that Linux does not support AF_INET6 here, but *BSD (and OSX)
+        /* Create the internet socket to test with.  Must use AF_INET;
-   probably would.
+           using AF_UNSPEC or AF_INET6 will cause everything to
-
+           fail. */
-   ifconf would be replaced by lifconf, SIOCG* by SIOCGL*.
-*/
         if ((sd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
-        opal_output(0, "opal_ifinit: socket() failed with errno=%d\n", errno);
+            opal_output(0, "opal_ifinit: socket() failed with errno=%d\n", 
+                        errno);
             return OPAL_ERROR;
         }
 
@@ -316,8 +299,9 @@ static int opal_ifinit(void)
                     return OPAL_ERROR;
                 }
             } else {
-            /* if ifc_len is 0 or different than what we set it to at
+                /* if ifc_len is 0 or different than what we set it to
-               call to ioctl, try again with a bigger buffer.  else stop */
+                   at call to ioctl, try again with a bigger buffer.
+                   else stop */
                 if (ifconf.ifc_len == lastlen && ifconf.ifc_len > 0) {
                     /* we didn't expand.  we're done */
                     successful_locate = true;
@@ -326,8 +310,8 @@ static int opal_ifinit(void)
                 lastlen = ifconf.ifc_len;
             }
             
-        /* Yes, we overflowed (or had an EINVAL on the ioctl).  Loop
+            /* Yes, we overflowed (or had an EINVAL on the ioctl).
-           back around and try again with a bigger buffer */
+               Loop back around and try again with a bigger buffer */
             free(ifconf.ifc_req);
             ifc_len = (ifc_len == 0) ? 1 : ifc_len * 2;
         } while (ifc_len < MAX_IFCONF_SIZE);
@@ -382,17 +366,20 @@ static int opal_ifinit(void)
                 opal_output(0, "opal_ifinit: ioctl(SIOCGIFFLAGS) failed with errno=%d", errno);
                 continue;
             }
-        if ((ifr->ifr_flags & IFF_UP) == 0) 
+            if ((ifr->ifr_flags & IFF_UP) == 0) {
                 continue;
+            }
 #ifdef IFF_SLAVE
             /* Is this a slave to a load balancer or bonded channel?
                If so, don't use it -- pick up the master instead */
-        if ((ifr->ifr_flags & IFF_SLAVE) != 0)
+            if ((ifr->ifr_flags & IFF_SLAVE) != 0) {
                 continue;
+            }
 #endif
 #if 0
-        if ((ifr->ifr_flags & IFF_LOOPBACK) != 0)
+            if ((ifr->ifr_flags & IFF_LOOPBACK) != 0) {
                 continue;
+            }
 #endif
             
             /* copy entry over into our data structure */
@@ -419,7 +406,8 @@ static int opal_ifinit(void)
 #endif
 #endif /* SIOCGIFINDEX */
             
-        /* This call returns IPv4 addresses only. Use SIOCGLIFADDR instead */
+            /* This call returns IPv4 addresses only. Use SIOCGLIFADDR
+               instead */
             if (ioctl(sd, SIOCGIFADDR, ifr) < 0) {
                 opal_output(0, "opal_ifinit: ioctl(SIOCGIFADDR) failed with errno=%d", errno);
                 break;
@@ -443,10 +431,9 @@ static int opal_ifinit(void)
         }
         free(ifconf.ifc_req);
         close(sd);
-
+    }        
 #endif /* anything other than {Net,Open,Free}BSD and DragonFly */
 
-
 #if OPAL_WANT_IPV6
 #ifdef __linux__ /* Linux does not have SIOCGL*, so parse
                      /proc/net/if_inet6 instead */
@@ -639,7 +626,6 @@ static int opal_ifinit(void)
                 (uint16_t) if_nametoindex(cur_ifaddrs->ifa_name);
             opal_list_append(&opal_if_list, &(intf->super));
         }   /*  of for loop over ifaddrs list */
-
     }
 #endif  /* bsd,  macosx */
 
@@ -1382,8 +1368,9 @@ bool opal_ifisloopback(int if_index)
 {
     opal_if_t* intf;
     int rc = opal_ifinit();
-    if(rc != OPAL_SUCCESS)
+    if (rc != OPAL_SUCCESS) {
         return rc;
+    }
     
     for (intf =  (opal_if_t*)opal_list_get_first(&opal_if_list);
         intf != (opal_if_t*)opal_list_get_end(&opal_if_list);