libsmb: No need to call dns_lookup_list_async() in discover_dc_dns()

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

diff --git a/source3/libsmb/dsgetdcname.c b/source3/libsmb/dsgetdcname.c
index aa23213bb5ae95a724e2ef4c19ee2d54eb5552de..ae90e07de77750e81aef65671e7a5f8de08bc99c 100644 (file)
--- a/source3/libsmb/dsgetdcname.c
+++ b/source3/libsmb/dsgetdcname.c
@@ -513,11 +513,6 @@ static NTSTATUS discover_dc_dns(TALLOC_CTX *mem_ctx,
        size_t numdcs = 0;
        struct ip_service_name *dclist = NULL;
        size_t ret_count = 0;
-       size_t num_dns_lookups = 0;
-       const char **dns_lookups = NULL;
-       size_t num_lookups_ret = 0;
-       struct samba_sockaddr *dns_addrs_ret = NULL;
-       char **dns_lookups_ret = NULL;
        char *query = NULL;
 
        if (flags & DS_PDC_REQUIRED) {
@@ -577,16 +572,6 @@ static NTSTATUS discover_dc_dns(TALLOC_CTX *mem_ctx,
        for (i = 0; i < numdcs; i++) {
                size_t j;
 
-               if (dcs[i].num_ips == 0) {
-                       /*
-                        * No addresses returned in the SRV
-                        * reply, we must look this up via
-                        * DNS.
-                        */
-                       num_dns_lookups++;
-                       continue;
-               }
-
                dclist[ret_count].hostname =
                        talloc_move(dclist, &dcs[i].hostname);
 
@@ -628,134 +613,16 @@ static NTSTATUS discover_dc_dns(TALLOC_CTX *mem_ctx,
                ret_count++;
        }
 
-       /*
-        * Now, create an array of hostnames we
-        * will asynchronously look up in DNS.
-        */
-       dns_lookups = talloc_zero_array(mem_ctx,
-                                       const char *,
-                                       num_dns_lookups);
-       if (dns_lookups == NULL) {
-               TALLOC_FREE(dcs);
-               TALLOC_FREE(dclist);
-               return NT_STATUS_NO_MEMORY;
-       }
-
-       num_dns_lookups = 0;
-       for (i = 0; i < numdcs; i++) {
-               if (dcs[i].num_ips != 0) {
-                       /*
-                        * We already got an address
-                        * for this via SRV return.
-                        */
-                       continue;
-               }
-               dns_lookups[num_dns_lookups] =
-                       talloc_strdup(mem_ctx, dcs[i].hostname);
-               if (dns_lookups[num_dns_lookups] == NULL) {
-                       TALLOC_FREE(dcs);
-                       TALLOC_FREE(dclist);
-                       TALLOC_FREE(dns_lookups);
-               }
-               num_dns_lookups++;
-       }
+       TALLOC_FREE(dcs);
 
-       status = dns_lookup_list_async(mem_ctx,
-                                      num_dns_lookups,
-                                      dns_lookups,
-                                      &num_lookups_ret,
-                                      &dns_addrs_ret,
-                                      &dns_lookups_ret);
-       if (!NT_STATUS_IS_OK(status)) {
-               TALLOC_FREE(dcs);
+       if (ret_count == 0) {
                TALLOC_FREE(dclist);
-               TALLOC_FREE(dns_lookups);
-               return status;
-       }
-
-       /*
-        * Remember, if we timed out or some
-        * addresses didn't look up then
-        * num_dns_lookups > num_lookups_ret,
-        * so there isn't a one to one correspondence.
-        *
-        * The order of the requests is preserved
-        * in the replies, but there may be requests
-        * for which there are no replies if we
-        * timed out.
-        *
-        * For example this means for looking up
-        * names:
-        *     NAME1
-        *     NAME2
-        *     NAME3
-        *
-        * The replies might look like:
-        *     NAME1 -> IPv4
-        *     NAME1 -> IPv4
-        *     NAME1 -> IPv6
-        *     NAME1 -> IPv6
-        *     NAME3 -> IPv6
-        *
-        * But they will never be in the order:
-        *
-        *     NAME2
-        *     NAME3
-        *     NAME1
-        *
-        * Also in dns_lookup_list_async()
-        * we arrange the requests/replies in
-        * the order IPv4 followed by IPv6, so in
-        * the replies, we can always pick the first
-        * reply - we know it will be IPv4 if there
-        * is an IPv4 for that name.
-        *
-        * Here ret_count is the index into the
-        * next entry in dclist we must fill (may
-        * be zero).
-        */
-
-       for (i = 0; i < num_lookups_ret; i++) {
-               dclist[ret_count].hostname =
-                       talloc_move(mem_ctx, &dns_lookups_ret[i]);
-               dclist[ret_count].sa = dns_addrs_ret[i];
-               /*
-                * Is this a duplicate name return.
-                * Remember we can look up both A and
-                * AAAA records which can return multiple
-                * addresses and the order of names
-                * is preserved.
-                */
-               if (ret_count > 0) {
-                       if (strcmp(dclist[ret_count-1].hostname,
-                                  dclist[ret_count].hostname) == 0) {
-                               /*
-                                * Same name. Keep the first address
-                                * which is IPv4 by preference.
-                                */
-                               continue;
-                       }
-               }
-               ret_count++;
-
-               if (ret_count == numdcs) {
-                       /* We've filled the return array. */
-                       break;
-               }
-       }
-
-       if (ret_count > 0) {
-               TALLOC_FREE(dcs);
-               TALLOC_FREE(dns_lookups);
-               *returned_dclist = dclist;
-               *return_count = ret_count;
-               return NT_STATUS_OK;
+               return NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND;
        }
 
-       TALLOC_FREE(dcs);
-       TALLOC_FREE(dclist);
-       TALLOC_FREE(dns_lookups);
-       return NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND;
+       *returned_dclist = dclist;
+       *return_count = ret_count;
+       return NT_STATUS_OK;
 }
 
 /****************************************************************