Cleanup of DC enumeration in get_dcs()

This is a fix for a few small inefficiencies/bugs in the get_dcs() path.

* because the third add_one_dc_unique() loop was outside the ADS check all DCs
  returned from the non-sitename lookup were being tacked onto the dc_name_ip
  list twice.
* add_one_dc_unique() now checks if the given IP address already exists before
  adding it to the list, making the returned list actually unique
* added more thorough doxygen comment headers
(This used to be commit cb2d488e1dbd90953c496c5e25d648977884f7e3)

diff --git a/source3/lib/util_sock.c b/source3/lib/util_sock.c
index 7356b3ec357f4857ac8e144fce1fadfc0b746168..e20768ed89242c0aade9714f5639f784807110e5 100644 (file)
--- a/source3/lib/util_sock.c
+++ b/source3/lib/util_sock.c
@@ -1379,11 +1379,22 @@ int open_socket_out(int type,
        return res;
 }
 
-/****************************************************************************
- Create an outgoing TCP socket to any of the addrs. This is for
- simultaneous connects to port 445 and 139 of a host or even a variety
- of DC's all of which are equivalent for our purposes.
-**************************************************************************/
+/*******************************************************************
+ Create an outgoing TCP socket to the first addr that connects.
+
+ This is for simultaneous connection attempts to port 445 and 139 of a host
+ or for simultatneous connection attempts to multiple DCs at once.  We return
+ a socket fd of the first successful connection.
+
+ @param[in] addrs list of Internet addresses and ports to connect to
+ @param[in] num_addrs number of address/port pairs in the addrs list
+ @param[in] timeout time after which we stop waiting for a socket connection
+            to succeed, given in milliseconds
+ @param[out] fd_index the entry in addrs which we successfully connected to
+ @param[out] fd fd of the open and connected socket
+ @return true on a successful connection, false if all connection attempts
+         failed or we timed out
+*******************************************************************/
 
 bool open_any_socket_out(struct sockaddr_storage *addrs, int num_addrs,
                         int timeout, int *fd_index, int *fd)

diff --git a/source3/libsmb/conncache.c b/source3/libsmb/conncache.c
index 05344f4071d344f3ba06829efc6478d7732024dd..b440d610485b830912c9d90792deef1c4a43e53f 100644 (file)
--- a/source3/libsmb/conncache.c
+++ b/source3/libsmb/conncache.c
@@ -177,7 +177,7 @@ void delete_negative_conn_cache(const char *domain, const char *server)
 
 
 /**
- * Add an entry to the failed conneciton cache
+ * Add an entry to the failed connection cache
  *
  * @param[in] domain
  * @param[in] server may be a FQDN or an IP addr in printable form

diff --git a/source3/winbindd/winbindd_cm.c b/source3/winbindd/winbindd_cm.c
index 71f1a56519660a6088fc83492eff992e9e65ac73..ce851649ba7c3608e570ccc18eeb8d2803bdab8c 100644 (file)
--- a/source3/winbindd/winbindd_cm.c
+++ b/source3/winbindd/winbindd_cm.c
@@ -1010,15 +1010,37 @@ static NTSTATUS cm_prepare_connection(const struct winbindd_domain *domain,
        return result;
 }
 
+/*******************************************************************
+ Add a dcname and sockaddr_storage pair to the end of a dc_name_ip
+ array.
+
+ Keeps the list unique by not adding duplicate entries.
+
+ @param[in] mem_ctx talloc memory context to allocate from
+ @param[in] domain_name domain of the DC
+ @param[in] dcname name of the DC to add to the list
+ @param[in] pss Internet address and port pair to add to the list
+ @param[in,out] dcs array of dc_name_ip structures to add to
+ @param[in,out] num_dcs number of dcs returned in the dcs array
+ @return true if the list was added to, false otherwise
+*******************************************************************/
+
 static bool add_one_dc_unique(TALLOC_CTX *mem_ctx, const char *domain_name,
                              const char *dcname, struct sockaddr_storage *pss,
                              struct dc_name_ip **dcs, int *num)
 {
+       int i = 0;
+
        if (!NT_STATUS_IS_OK(check_negative_conn_cache(domain_name, dcname))) {
                DEBUG(10, ("DC %s was in the negative conn cache\n", dcname));
                return False;
        }
 
+       /* Make sure there's no duplicates in the list */
+       for (i=0; i<*num; i++)
+               if (addr_equal(&(*dcs)[i].ss, pss))
+                       return False;
+
        *dcs = TALLOC_REALLOC_ARRAY(mem_ctx, *dcs, struct dc_name_ip, (*num)+1);
 
        if (*dcs == NULL)
@@ -1151,8 +1173,15 @@ static bool dcip_to_name(TALLOC_CTX *mem_ctx,
 }
 
 /*******************************************************************
- Retreive a list of IP address for domain controllers.  Fill in 
- the dcs[]  with results.
+ Retrieve a list of IP addresses for domain controllers.
+
+ The array is sorted in the preferred connection order.
+
+ @param[in] mem_ctx talloc memory context to allocate from
+ @param[in] domain domain to retrieve DCs for
+ @param[out] dcs array of dcs that will be returned
+ @param[out] num_dcs number of dcs returned in the dcs array
+ @return always true
 *******************************************************************/
 
 static bool get_dcs(TALLOC_CTX *mem_ctx, struct winbindd_domain *domain,
@@ -1168,9 +1197,11 @@ static bool get_dcs(TALLOC_CTX *mem_ctx, struct winbindd_domain *domain,
 
        is_our_domain = strequal(domain->name, lp_workgroup());
 
+       /* If not our domain, get the preferred DC, by asking our primary DC */
        if ( !is_our_domain
                && get_dc_name_via_netlogon(domain, dcname, &ss)
-               && add_one_dc_unique(mem_ctx, domain->name, dcname, &ss, dcs, num_dcs) )
+               && add_one_dc_unique(mem_ctx, domain->name, dcname, &ss, dcs,
+                      num_dcs) )
        {
                char addr[INET6_ADDRSTRLEN];
                print_sockaddr(addr, sizeof(addr), &ss);
@@ -1197,8 +1228,13 @@ static bool get_dcs(TALLOC_CTX *mem_ctx, struct winbindd_domain *domain,
                if (sitename) {
 
                        /* Do the site-specific AD dns lookup first. */
-                       get_sorted_dc_list(domain->alt_name, sitename, &ip_list, &iplist_size, True);
+                       get_sorted_dc_list(domain->alt_name, sitename, &ip_list,
+                              &iplist_size, True);
 
+                       /* Add ips to the DC array.  We don't look up the name
+                          of the DC in this function, but we fill in the char*
+                          of the ip now to make the failed connection cache
+                          work */
                        for ( i=0; i<iplist_size; i++ ) {
                                char addr[INET6_ADDRSTRLEN];
                                print_sockaddr(addr, sizeof(addr),
@@ -1216,8 +1252,9 @@ static bool get_dcs(TALLOC_CTX *mem_ctx, struct winbindd_domain *domain,
                        iplist_size = 0;
                }
 
-               /* Now we add DCs from the main AD dns lookup. */
-               get_sorted_dc_list(domain->alt_name, NULL, &ip_list, &iplist_size, True);
+               /* Now we add DCs from the main AD DNS lookup. */
+               get_sorted_dc_list(domain->alt_name, NULL, &ip_list,
+                       &iplist_size, True);
 
                for ( i=0; i<iplist_size; i++ ) {
                        char addr[INET6_ADDRSTRLEN];
@@ -1230,33 +1267,46 @@ static bool get_dcs(TALLOC_CTX *mem_ctx, struct winbindd_domain *domain,
                                        dcs,
                                        num_dcs);
                }
-        }
 
-       /* try standard netbios queries if no ADS */
-
-       if (iplist_size==0) {
-               get_sorted_dc_list(domain->name, NULL, &ip_list, &iplist_size, False);
-       }
+               SAFE_FREE(ip_list);
+               iplist_size = 0;
+        }
 
-       /* FIXME!! this is where we should re-insert the GETDC requests --jerry */
+       /* Try standard netbios queries if no ADS */
+       if (*num_dcs == 0) {
+               get_sorted_dc_list(domain->name, NULL, &ip_list, &iplist_size,
+                      False);
 
-       /* now add to the dc array.  We'll wait until the last minute 
-          to look up the name of the DC.  But we fill in the char* for 
-          the ip now in to make the failed connection cache work */
+               for ( i=0; i<iplist_size; i++ ) {
+                       char addr[INET6_ADDRSTRLEN];
+                       print_sockaddr(addr, sizeof(addr),
+                                       &ip_list[i].ss);
+                       add_one_dc_unique(mem_ctx,
+                                       domain->name,
+                                       addr,
+                                       &ip_list[i].ss,
+                                       dcs,
+                                       num_dcs);
+               }
 
-       for ( i=0; i<iplist_size; i++ ) {
-               char addr[INET6_ADDRSTRLEN];
-               print_sockaddr(addr, sizeof(addr),
-                               &ip_list[i].ss);
-               add_one_dc_unique(mem_ctx, domain->name, addr,
-                       &ip_list[i].ss, dcs, num_dcs);
+               SAFE_FREE(ip_list);
+               iplist_size = 0;
        }
 
-       SAFE_FREE( ip_list );
-
        return True;
 }
 
+/*******************************************************************
+ Find and make a connection to a DC in the given domain.
+
+ @param[in] mem_ctx talloc memory context to allocate from
+ @param[in] domain domain to find a dc in
+ @param[out] dcname NetBIOS or FQDN of DC that's connected to
+ @param[out] pss DC Internet address and port
+ @param[out] fd fd of the open socket connected to the newly found dc
+ @return true when a DC connection is made, false otherwise
+*******************************************************************/
+
 static bool find_new_dc(TALLOC_CTX *mem_ctx,
                        struct winbindd_domain *domain,
                        fstring dcname, struct sockaddr_storage *pss, int *fd)