From 6452eb4960a542328615730b6a11d24a1281a457 Mon Sep 17 00:00:00 2001
From: Jeffrey Hutzelman <jhutz@cmu.edu>
Date: Sun, 25 Nov 2012 04:55:43 -0500
Subject: Introduce usable flag on other-realm servers

Introduce a new per-realm-server 'usable' flag, which indicates the entry has
been fully initialized and can be used.  Routines which select a server or
attempt to find one based on its address should ignore servers on which the
usable flag is not set.

This will allow the introduction of features which require recording servers
which are not yet usable, such as asynchronous server name resolution.
---
 server/realm.c   | 23 ++++++++++++++++++-----
 server/zserver.h |  1 +
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/server/realm.c b/server/realm.c
index bda371b..431893e 100644
--- a/server/realm.c
+++ b/server/realm.c
@@ -83,9 +83,12 @@ realm_get_idx_by_addr(ZRealm *realm,
     int b;
 
     /* loop through the realms */
-    for (srvr = realm->srvrs, b = 0; b < realm->count; b++, srvr++)
+    for (srvr = realm->srvrs, b = 0; b < realm->count; b++, srvr++) {
+	if (!srvr->usable)
+	    continue;
 	if (srvr->addr.sin_addr.s_addr == who->sin_addr.s_addr)
 	    return(b);
+    }
 
     return 0;
 }
@@ -102,15 +105,21 @@ realm_next_idx_by_idx(realm, idx)
     srvr = realm->srvrs; a = idx;
     while (a > 0) { a--; srvr++; }
 
-    for (srvr, b = idx; b < realm->count; b++, srvr++)
+    for (srvr, b = idx; b < realm->count; b++, srvr++) {
+	if (!srvr->usable)
+	    continue;
 	if (!srvr->dontsend)
 	    return(b);
+    }
 
     /* recycle */
     if (idx != 0)
-	for (srvr = realm->srvrs, b = 0; b < idx; b++, srvr++)
+	for (srvr = realm->srvrs, b = 0; b < idx; b++, srvr++) {
+	    if (!srvr->usable)
+		continue;
 	    if (!srvr->dontsend)
-	    return(b);
+		return(b);
+	}
 
     return 0;
 }
@@ -315,9 +324,12 @@ realm_which_realm(struct sockaddr_in *who)
     /* loop through the realms */
     for (realm = otherrealms, a = 0; a < nrealms; a++, realm++)
 	/* loop through the addresses for the realm */
-	for (srvr = realm->srvrs, b = 0; b < realm->count; b++, srvr++)
+	for (srvr = realm->srvrs, b = 0; b < realm->count; b++, srvr++) {
+	    if (!srvr->usable)
+		continue;
 	    if (srvr->addr.sin_addr.s_addr == who->sin_addr.s_addr)
 		return(realm);
+	}
 
     return 0;
 }
@@ -550,6 +562,7 @@ realm_init(void)
 	    /* use the server port */
 	    srvr->addr.sin_port = srv_addr.sin_port;
 	    srvr->addr.sin_family = AF_INET;
+	    srvr->usable = 1;
 	    srvr->dontsend = nosend[jj];
 	}
 	client = (Client *) malloc(sizeof(Client));
diff --git a/server/zserver.h b/server/zserver.h
index 20c229d..b61cc06 100644
--- a/server/zserver.h
+++ b/server/zserver.h
@@ -113,6 +113,7 @@ struct _Destlist {
 
 struct _ZRealm_server {
     struct sockaddr_in addr;		/* server's address */
+    unsigned int usable :1;             /* set once entry is usable */
     unsigned int dontsend :1;		/* private server, do not send */
 };
 
-- 
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