Much more useful handling of backup domain controllers in winbindd. Honour

the "password server" smb.conf parameter when choosing a DC to connect to.

Due to the origin of the code in cm_get_dc_name() it wouldn't try
additional DCs if the first DC didn't work.  This would wedge winbindd if you
had "password server = foo1, foo2" and foo1 was down.

diff --git a/source/nsswitch/winbindd_cm.c b/source/nsswitch/winbindd_cm.c
index 5d6c758e10743f672812b82e68af509bf72803d5..611a4c92216b930d36bd2f3bcce969cd1cb5b9ee 100644 (file)
--- a/source/nsswitch/winbindd_cm.c
+++ b/source/nsswitch/winbindd_cm.c
@@ -92,7 +92,7 @@ static BOOL cm_get_dc_name(char *domain, fstring srv_name)
        static struct get_dc_name_cache *get_dc_name_cache;
        struct get_dc_name_cache *dcc;
        struct in_addr *ip_list, dc_ip;
-       int count, i;
+       int count, i = 0;
 
        /* Check the cache for previous lookups */
 
@@ -147,38 +147,64 @@ static BOOL cm_get_dc_name(char *domain, fstring srv_name)
                DEBUG(3, ("Could not look up dc's for domain %s\n", domain));
                return False;
        }
+
+       /* Pick a nice close server */
+          
+       if (strequal(lp_passwordserver(), "*")) {
                
-       /* Firstly choose a PDC/BDC who has the same network address as any
-          of our interfaces. */
-       
-       for (i = 0; i < count; i++) {
-               if(is_local_net(ip_list[i]))
-                       goto got_ip;
-       }
+               /* Look for DC on local net */
+
+               for (i = 0; i < count; i++) {
+                       if (is_local_net(ip_list[i]) &&
+                           name_status_find(domain, 0x1c, 0x20,
+                                            ip_list[i], srv_name)) {
+                               dc_ip = ip_list[i];
+                               goto done;
+                       }
+                       zero_ip(&ip_list[i]);
+               }
+
+               /* Look for other DCs */
+
+               for (i = 0; i < count; i++) {
+                       if (!is_zero_ip(ip_list[i]) &&
+                           name_status_find(domain, 0x1c, 0x20,
+                                            ip_list[i], srv_name)) {
+                               dc_ip = ip_list[i];
+                               goto done;
+                       }
+               }
+
+               /* No-one to talk to )-: */
 
-       if (count == 0) {
-               DEBUG(3, ("No domain controllers for domain %s\n", domain));
                return False;
        }
-       
-       i = (sys_random() % count);
-       
- got_ip:
-       dc_ip = ip_list[i];
-       SAFE_FREE(ip_list);
-               
-       /* We really should be doing a GETDC call here rather than a node
-          status lookup. */
 
-       if (!name_status_find(domain, 0x1c, 0x20, dc_ip, srv_name)) {
-               DEBUG(3, ("Error looking up DC name for %s in domain %s\n", inet_ntoa(dc_ip), domain));
-               return False;
+       /* Return first DC that we can contact */
+
+       for (i = 0; i < count; i++) {
+               if (name_status_find(domain, 0x1c, 0x20, ip_list[i],
+                                    srv_name)) {
+                       dc_ip = ip_list[i];
+                       goto done;
+               }
        }
 
+       return False;           /* Boo-hoo */
+       
+ done:
+       /* We have the netbios name and IP address of a domain controller.
+          Ideally we should sent a SAMLOGON request to determine whether
+          the DC is alive and kicking.  If we can catch a dead DC before
+          performing a cli_connect() we can avoid a 30-second timeout. */
+
        /* We have a name so make the cache entry positive now */
 
        fstrcpy(dcc->srv_name, srv_name);
 
+       DEBUG(3, ("Returning DC %s (%s) for domain %s\n", srv_name,
+                 inet_ntoa(dc_ip), domain));
+
        return True;
 }
 
@@ -239,14 +265,14 @@ static BOOL cm_open_connection(char *domain, char *pipe_name,
        fstrcpy(new_conn->pipe_name, pipe_name);
        
        /* Look for a domain controller for this domain.  Negative results
-               are cached so don't bother applying the caching for this
-               function just yet.  */
+          are cached so don't bother applying the caching for this
+          function just yet.  */
 
        if (!cm_get_dc_name(domain, new_conn->controller))
                goto done;
 
        /* Return false if we have tried to look up this domain and netbios
-               name before and failed. */
+          name before and failed. */
 
        for (occ = open_connection_cache; occ; occ = occ->next) {