RIP BOOL. Convert BOOL -> bool. I found a few interesting
[nivanova/samba-autobuild/.git] / source3 / libads / dns.c
index 937cd9213f9845d014d861cf3844261ebce2b112..7959e910a8de0aefaed79e7efc81fb66d5dc747c 100644 (file)
@@ -5,7 +5,7 @@
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2 of the License, or
+   the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.
    
    This program is distributed in the hope that it will be useful,
@@ -14,8 +14,7 @@
    GNU General Public License for more details.
    
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 #include "includes.h"
@@ -46,7 +45,9 @@
 #  define T_A          ns_t_a
 #endif
 #  define T_SRV        ns_t_srv
+#if !defined(T_NS)     /* AIX 5.3 already defines T_NS */
 #  define T_NS                 ns_t_ns
+#endif
 #else
 #  ifdef HFIXEDSZ
 #    define NS_HFIXEDSZ HFIXEDSZ
@@ -64,7 +65,7 @@
 /*********************************************************************
 *********************************************************************/
 
-static BOOL ads_dns_parse_query( TALLOC_CTX *ctx, uint8 *start, uint8 *end,
+static bool ads_dns_parse_query( TALLOC_CTX *ctx, uint8 *start, uint8 *end,
                           uint8 **ptr, struct dns_query *q )
 {
        uint8 *p = *ptr;
@@ -102,7 +103,7 @@ static BOOL ads_dns_parse_query( TALLOC_CTX *ctx, uint8 *start, uint8 *end,
 /*********************************************************************
 *********************************************************************/
 
-static BOOL ads_dns_parse_rr( TALLOC_CTX *ctx, uint8 *start, uint8 *end,
+static bool ads_dns_parse_rr( TALLOC_CTX *ctx, uint8 *start, uint8 *end,
                        uint8 **ptr, struct dns_rr *rr )
 {
        uint8 *p = *ptr;
@@ -156,7 +157,7 @@ static BOOL ads_dns_parse_rr( TALLOC_CTX *ctx, uint8 *start, uint8 *end,
 /*********************************************************************
 *********************************************************************/
 
-static BOOL ads_dns_parse_rr_srv( TALLOC_CTX *ctx, uint8 *start, uint8 *end,
+static bool ads_dns_parse_rr_srv( TALLOC_CTX *ctx, uint8 *start, uint8 *end,
                        uint8 **ptr, struct dns_rr_srv *srv )
 {
        struct dns_rr rr;
@@ -201,7 +202,7 @@ static BOOL ads_dns_parse_rr_srv( TALLOC_CTX *ctx, uint8 *start, uint8 *end,
 /*********************************************************************
 *********************************************************************/
 
-static BOOL ads_dns_parse_rr_ns( TALLOC_CTX *ctx, uint8 *start, uint8 *end,
+static bool ads_dns_parse_rr_ns( TALLOC_CTX *ctx, uint8 *start, uint8 *end,
                        uint8 **ptr, struct dns_rr_ns *nsrec )
 {
        struct dns_rr rr;
@@ -268,35 +269,76 @@ static int dnssrvcmp( struct dns_rr_srv *a, struct dns_rr_srv *b )
  Simple wrapper for a DNS query
 *********************************************************************/
 
+#define DNS_FAILED_WAITTIME          30
+
 static NTSTATUS dns_send_req( TALLOC_CTX *ctx, const char *name, int q_type, 
                               uint8 **buf, int *resp_length )
 {
        uint8 *buffer = NULL;
        size_t buf_len;
        int resp_len = NS_PACKETSZ;     
-       
+       static time_t last_dns_check = 0;
+       static NTSTATUS last_dns_status = NT_STATUS_OK; 
+       time_t now = time(NULL);
+
+       /* Try to prevent bursts of DNS lookups if the server is down */
+
+       /* Protect against large clock changes */
+
+       if ( last_dns_check > now )
+               last_dns_check = 0;
+
+       /* IF we had a DNS timeout or a bad server and we are still 
+          in the 30 second cache window, just return the previous 
+          status and save the network timeout. */
+
+       if ( (NT_STATUS_EQUAL(last_dns_status,NT_STATUS_IO_TIMEOUT) ||
+             NT_STATUS_EQUAL(last_dns_status,NT_STATUS_CONNECTION_REFUSED)) &&
+            (last_dns_check+DNS_FAILED_WAITTIME) > now ) 
+       {
+               DEBUG(10,("last_dns_check: Returning cached status (%s)\n",
+                         nt_errstr(last_dns_status) ));
+               return last_dns_status;
+       }
+
+       /* Send the Query */
        do {
                if ( buffer )
                        TALLOC_FREE( buffer );
                
                buf_len = resp_len * sizeof(uint8);
 
-               if ( (buffer = TALLOC_ARRAY(ctx, uint8, buf_len)) == NULL ) {
-                       DEBUG(0,("ads_dns_lookup_srv: talloc() failed!\n"));
-                       return NT_STATUS_NO_MEMORY;
+               if (buf_len) {                  
+                       if ( (buffer = TALLOC_ARRAY(ctx, uint8, buf_len)) == NULL ) {
+                               DEBUG(0,("ads_dns_lookup_srv: talloc() failed!\n"));
+                               last_dns_status = NT_STATUS_NO_MEMORY;
+                               last_dns_check = time(NULL);
+                               return last_dns_status; 
+                       }
                }
 
                if ( (resp_len = res_query(name, C_IN, q_type, buffer, buf_len)) < 0 ) {
-                       DEBUG(1,("ads_dns_lookup_srv: Failed to resolve %s (%s)\n", name, strerror(errno)));
+                       DEBUG(3,("ads_dns_lookup_srv: Failed to resolve %s (%s)\n", name, strerror(errno)));
                        TALLOC_FREE( buffer );
-                       return NT_STATUS_UNSUCCESSFUL;
+                       last_dns_status = NT_STATUS_UNSUCCESSFUL;
+                       
+                       if (errno == ETIMEDOUT) {
+                               last_dns_status = NT_STATUS_IO_TIMEOUT;                         
+                       }
+                       if (errno == ECONNREFUSED) {
+                               last_dns_status = NT_STATUS_CONNECTION_REFUSED;                         
+                       }
+                       last_dns_check = time(NULL);
+                       return last_dns_status;
                }
        } while ( buf_len < resp_len && resp_len < MAX_DNS_PACKET_SIZE );
        
        *buf = buffer;
        *resp_length = resp_len;
 
-       return NT_STATUS_OK;
+       last_dns_check = time(NULL);
+       last_dns_status = NT_STATUS_OK; 
+       return last_dns_status;
 }
 
 /*********************************************************************
@@ -323,7 +365,7 @@ static NTSTATUS ads_dns_lookup_srv( TALLOC_CTX *ctx, const char *name, struct dn
 
        status = dns_send_req( ctx, name, T_SRV, &buffer, &resp_len );
        if ( !NT_STATUS_IS_OK(status) ) {
-               DEBUG(0,("ads_dns_lookup_srv: Failed to send DNS query (%s)\n",
+               DEBUG(3,("ads_dns_lookup_srv: Failed to send DNS query (%s)\n",
                        nt_errstr(status)));
                return status;
        }
@@ -343,10 +385,14 @@ static NTSTATUS ads_dns_lookup_srv( TALLOC_CTX *ctx, const char *name, struct dn
        DEBUG(4,("ads_dns_lookup_srv: %d records returned in the answer section.\n", 
                answer_count));
                
-       if ( (dcs = TALLOC_ZERO_ARRAY(ctx, struct dns_rr_srv, answer_count)) == NULL ) {
-               DEBUG(0,("ads_dns_lookup_srv: talloc() failure for %d char*'s\n", 
-                       answer_count));
-               return NT_STATUS_NO_MEMORY;
+       if (answer_count) {
+               if ( (dcs = TALLOC_ZERO_ARRAY(ctx, struct dns_rr_srv, answer_count)) == NULL ) {
+                       DEBUG(0,("ads_dns_lookup_srv: talloc() failure for %d char*'s\n", 
+                               answer_count));
+                       return NT_STATUS_NO_MEMORY;
+               }
+       } else {
+               dcs = NULL;
        }
 
        /* now skip the header */
@@ -471,7 +517,7 @@ NTSTATUS ads_dns_lookup_ns( TALLOC_CTX *ctx, const char *dnsdomain, struct dns_r
           
        status = dns_send_req( ctx, dnsdomain, T_NS, &buffer, &resp_len );
        if ( !NT_STATUS_IS_OK(status) ) {
-               DEBUG(0,("ads_dns_lookup_ns: Failed to send DNS query (%s)\n",
+               DEBUG(3,("ads_dns_lookup_ns: Failed to send DNS query (%s)\n",
                        nt_errstr(status)));
                return status;
        }
@@ -491,10 +537,14 @@ NTSTATUS ads_dns_lookup_ns( TALLOC_CTX *ctx, const char *dnsdomain, struct dns_r
        DEBUG(4,("ads_dns_lookup_ns: %d records returned in the answer section.\n", 
                answer_count));
                
-       if ( (nsarray = TALLOC_ARRAY(ctx, struct dns_rr_ns, answer_count)) == NULL ) {
-               DEBUG(0,("ads_dns_lookup_ns: talloc() failure for %d char*'s\n", 
-                       answer_count));
-               return NT_STATUS_NO_MEMORY;
+       if (answer_count) {
+               if ( (nsarray = TALLOC_ARRAY(ctx, struct dns_rr_ns, answer_count)) == NULL ) {
+                       DEBUG(0,("ads_dns_lookup_ns: talloc() failure for %d char*'s\n", 
+                               answer_count));
+                       return NT_STATUS_NO_MEMORY;
+               }
+       } else {
+               nsarray = NULL;
        }
 
        /* now skip the header */
@@ -569,33 +619,56 @@ NTSTATUS ads_dns_lookup_ns( TALLOC_CTX *ctx, const char *dnsdomain, struct dns_r
  Store and fetch the AD client sitename.
 ****************************************************************************/
 
-#define SITENAME_KEY   "AD_SITENAME"
+#define SITENAME_KEY   "AD_SITENAME/DOMAIN/%s"
+
+static char *sitename_key(const char *realm)
+{
+       char *keystr;
+       
+       if (asprintf(&keystr, SITENAME_KEY, strupper_static(realm)) == -1) {
+               return NULL;
+       }
+
+       return keystr;
+}
+
 
 /****************************************************************************
  Store the AD client sitename.
  We store indefinately as every new CLDAP query will re-write this.
 ****************************************************************************/
 
-BOOL sitename_store(const char *sitename)
+bool sitename_store(const char *realm, const char *sitename)
 {
        time_t expire;
-       BOOL ret = False;
-       
-       if ( !sitename || (sitename && !*sitename)) {
-               DEBUG(2,("sitename_store: deleting empty sitename!\n"));
-               return gencache_del(SITENAME_KEY);
-       }
-       
+       bool ret = False;
+       char *key;
+
        if (!gencache_init()) {
                return False;
        }
+
+       if (!realm || (strlen(realm) == 0)) {
+               DEBUG(0,("sitename_store: no realm\n"));
+               return False;
+       }
        
+       key = sitename_key(realm);
+
+       if (!sitename || (sitename && !*sitename)) {
+               DEBUG(5,("sitename_store: deleting empty sitename!\n"));
+               ret = gencache_del(key);
+               SAFE_FREE(key);
+               return ret;
+       }
+
        expire = get_time_t_max(); /* Store indefinately. */
        
-       DEBUG(10,("sitename_store: sitename = [%s], expire = [%u]\n",
-               sitename, (unsigned int)expire ));
+       DEBUG(10,("sitename_store: realm = [%s], sitename = [%s], expire = [%u]\n",
+               realm, sitename, (unsigned int)expire ));
 
-       ret = gencache_set( SITENAME_KEY, sitename, expire );
+       ret = gencache_set( key, sitename, expire );
+       SAFE_FREE(key);
        return ret;
 }
 
@@ -604,43 +677,86 @@ BOOL sitename_store(const char *sitename)
  Caller must free.
 ****************************************************************************/
 
-static char *sitename_fetch(void)
+char *sitename_fetch(const char *realm)
 {
        char *sitename = NULL;
        time_t timeout;
-       BOOL ret = False;
+       bool ret = False;
+       const char *query_realm;
+       char *key;
        
        if (!gencache_init()) {
                return False;
        }
-       
-       ret = gencache_get( SITENAME_KEY, &sitename, &timeout );
+
+       if (!realm || (strlen(realm) == 0)) {
+               query_realm = lp_realm(); 
+       } else {
+               query_realm = realm;
+       }
+
+       key = sitename_key(query_realm);
+
+       ret = gencache_get( key, &sitename, &timeout );
+       SAFE_FREE(key);
        if ( !ret ) {
-               DEBUG(5,("sitename_fetch: No stored sitename\n"));
+               DEBUG(5,("sitename_fetch: No stored sitename for %s\n",
+                       query_realm));
        } else {
-               DEBUG(5,("sitename_fetch: Returning sitename \"%s\"\n",
-                       sitename ));
+               DEBUG(5,("sitename_fetch: Returning sitename for %s: \"%s\"\n",
+                       query_realm, sitename ));
        }
        return sitename;
 }
 
+/****************************************************************************
+ Did the sitename change ?
+****************************************************************************/
+
+bool stored_sitename_changed(const char *realm, const char *sitename)
+{
+       bool ret = False;
+
+       char *new_sitename;
+
+       if (!realm || (strlen(realm) == 0)) {
+               DEBUG(0,("stored_sitename_changed: no realm\n"));
+               return False;
+       }
+
+       new_sitename = sitename_fetch(realm);
+
+       if (sitename && new_sitename && !strequal(sitename, new_sitename)) {
+               ret = True;
+       } else if ((sitename && !new_sitename) ||
+                       (!sitename && new_sitename)) {
+               ret = True;
+       }
+       SAFE_FREE(new_sitename);
+       return ret;
+}
+
 /********************************************************************
  Query with optional sitename.
 ********************************************************************/
 
-NTSTATUS ads_dns_query_dcs_internal(TALLOC_CTX *ctx,
-                               const char *domain,
-                               const char *sitename,
-                               struct dns_rr_srv **dclist,
-                               int *numdcs )
+static NTSTATUS ads_dns_query_internal(TALLOC_CTX *ctx,
+                                      const char *servicename,
+                                      const char *dc_pdc_gc_domains,
+                                      const char *realm,
+                                      const char *sitename,
+                                      struct dns_rr_srv **dclist,
+                                      int *numdcs )
 {
        char *name;
        if (sitename) {
-               name = talloc_asprintf(ctx, "_ldap._tcp.%s._sites.dc._msdcs.%s",
-                               sitename, domain );
-       } else {
-               name = talloc_asprintf(ctx, "_ldap._tcp.dc._msdcs.%s", domain );
-       }
+               name = talloc_asprintf(ctx, "%s._tcp.%s._sites.%s._msdcs.%s",
+                                      servicename, sitename,
+                                      dc_pdc_gc_domains, realm);
+       } else {
+               name = talloc_asprintf(ctx, "%s._tcp.%s._msdcs.%s",
+                               servicename, dc_pdc_gc_domains, realm);
+       }
        if (!name) {
                return NT_STATUS_NO_MEMORY;
        }
@@ -648,22 +764,138 @@ NTSTATUS ads_dns_query_dcs_internal(TALLOC_CTX *ctx,
 }
 
 /********************************************************************
- Query for AD DC's. Transparently use sitename.
+ Query for AD DC's.
 ********************************************************************/
 
 NTSTATUS ads_dns_query_dcs(TALLOC_CTX *ctx,
-                       const char *domain,
-                       struct dns_rr_srv **dclist,
-                       int *numdcs )
+                          const char *realm,
+                          const char *sitename,
+                          struct dns_rr_srv **dclist,
+                          int *numdcs )
+{
+       NTSTATUS status;
+
+       status = ads_dns_query_internal(ctx, "_ldap", "dc", realm, sitename,
+                                       dclist, numdcs);
+
+       if (NT_STATUS_EQUAL(status, NT_STATUS_IO_TIMEOUT) ||
+           NT_STATUS_EQUAL(status, NT_STATUS_CONNECTION_REFUSED)) {
+               return status;
+       }
+
+       if (sitename &&
+           ((!NT_STATUS_IS_OK(status)) ||
+            (NT_STATUS_IS_OK(status) && (numdcs == 0)))) {
+               /* Sitename DNS query may have failed. Try without. */
+               status = ads_dns_query_internal(ctx, "_ldap", "dc", realm,
+                                               NULL, dclist, numdcs);
+       }
+       return status;
+}
+
+/********************************************************************
+ Query for AD GC's.
+********************************************************************/
+
+NTSTATUS ads_dns_query_gcs(TALLOC_CTX *ctx,
+                          const char *realm,
+                          const char *sitename,
+                          struct dns_rr_srv **dclist,
+                          int *numdcs )
+{
+       NTSTATUS status;
+
+       status = ads_dns_query_internal(ctx, "_ldap", "gc", realm, sitename,
+                                       dclist, numdcs);
+
+       if (NT_STATUS_EQUAL(status, NT_STATUS_IO_TIMEOUT) ||
+           NT_STATUS_EQUAL(status, NT_STATUS_CONNECTION_REFUSED)) {
+               return status;
+       }
+
+       if (sitename &&
+           ((!NT_STATUS_IS_OK(status)) ||
+            (NT_STATUS_IS_OK(status) && (numdcs == 0)))) {
+               /* Sitename DNS query may have failed. Try without. */
+               status = ads_dns_query_internal(ctx, "_ldap", "gc", realm,
+                                               NULL, dclist, numdcs);
+       }
+       return status;
+}
+
+/********************************************************************
+ Query for AD KDC's.
+ Even if our underlying kerberos libraries are UDP only, this
+ is pretty safe as it's unlikely that a KDC supports TCP and not UDP.
+********************************************************************/
+
+NTSTATUS ads_dns_query_kdcs(TALLOC_CTX *ctx,
+                           const char *dns_forest_name,
+                           const char *sitename,
+                           struct dns_rr_srv **dclist,
+                           int *numdcs )
 {
        NTSTATUS status;
-       char *sitename = sitename_fetch();
 
-       status = ads_dns_query_dcs_internal(ctx, domain, sitename, dclist, numdcs);
-       if (sitename && !NT_STATUS_IS_OK(status)) {
+       status = ads_dns_query_internal(ctx, "_kerberos", "dc",
+                                       dns_forest_name, sitename, dclist,
+                                       numdcs);
+
+       if (NT_STATUS_EQUAL(status, NT_STATUS_IO_TIMEOUT) ||
+           NT_STATUS_EQUAL(status, NT_STATUS_CONNECTION_REFUSED)) {
+               return status;
+       }
+
+       if (sitename &&
+           ((!NT_STATUS_IS_OK(status)) ||
+            (NT_STATUS_IS_OK(status) && (numdcs == 0)))) {
                /* Sitename DNS query may have failed. Try without. */
-               status = ads_dns_query_dcs_internal(ctx, domain, NULL, dclist, numdcs);
+               status = ads_dns_query_internal(ctx, "_kerberos", "dc",
+                                               dns_forest_name, NULL,
+                                               dclist, numdcs);
        }
-       SAFE_FREE(sitename);
        return status;
 }
+
+/********************************************************************
+ Query for AD PDC. Sitename is obsolete here.
+********************************************************************/
+
+NTSTATUS ads_dns_query_pdc(TALLOC_CTX *ctx,
+                          const char *dns_domain_name,
+                          struct dns_rr_srv **dclist,
+                          int *numdcs )
+{
+       return ads_dns_query_internal(ctx, "_ldap", "pdc", dns_domain_name,
+                                     NULL, dclist, numdcs);
+}
+
+/********************************************************************
+ Query for AD DC by guid. Sitename is obsolete here.
+********************************************************************/
+
+NTSTATUS ads_dns_query_dcs_guid(TALLOC_CTX *ctx,
+                               const char *dns_forest_name,
+                               const struct GUID *domain_guid,
+                               struct dns_rr_srv **dclist,
+                               int *numdcs )
+{
+       /*_ldap._tcp.DomainGuid.domains._msdcs.DnsForestName */
+
+       const char *domains;
+       const char *guid_string;
+
+       guid_string = GUID_string(ctx, domain_guid);
+       if (!guid_string) {
+               return NT_STATUS_NO_MEMORY;
+       }
+
+       /* little hack */
+       domains = talloc_asprintf(ctx, "%s.domains", guid_string);
+       if (!domains) {
+               return NT_STATUS_NO_MEMORY;
+       }
+
+       return ads_dns_query_internal(ctx, "_ldap", domains, dns_forest_name,
+                                     NULL, dclist, numdcs);
+}