s4:kdc: flatten samba_kdc_lookup_client dollar fallback

There is a single linear successful path through the 'num_comp == 1'
and various NULL checks, but it is written in a branchy fashion as if
you could skip some portion.

git diff -b is probably useful.

Signed-off-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Reviewed-by: Jennifer Sutton <jennifersutton@catalyst.net.nz>

diff --git a/source4/kdc/db-glue.c b/source4/kdc/db-glue.c
index 0ce276aee18247c0354da1cd8ac330961a6973a0..522d9ff5b082223eb19325e0015cfa7e61031710 100644 (file)
--- a/source4/kdc/db-glue.c
+++ b/source4/kdc/db-glue.c
@@ -3418,12 +3418,17 @@ static krb5_error_code samba_kdc_lookup_client(krb5_context context,
        nt_status = sam_get_results_principal(kdc_db_ctx->samdb,
                                              mem_ctx, principal_string, attrs, dsdb_flags,
                                              realm_dn, msg);
+
        if (NT_STATUS_EQUAL(nt_status, NT_STATUS_NO_SUCH_USER)) {
+               /* we will try again with a '$' appended */
                krb5_principal fallback_principal = NULL;
                unsigned int num_comp;
                char *fallback_realm = NULL;
                char *fallback_account = NULL;
+               char *with_dollar = NULL;
+               char *fallback_string = NULL;
                krb5_error_code ret;
+               size_t len;
 
                ret = krb5_parse_name(context, principal_string,
                                      &fallback_principal);
@@ -3433,6 +3438,11 @@ static krb5_error_code samba_kdc_lookup_client(krb5_context context,
                }
 
                num_comp = krb5_princ_size(context, fallback_principal);
+               if (num_comp != 1) {
+                       krb5_free_principal(context, fallback_principal);
+                       return SDB_ERR_NOENTRY;
+               }
+
                fallback_realm = smb_krb5_principal_get_realm(
                        mem_ctx, context, fallback_principal);
                if (fallback_realm == NULL) {
@@ -3440,68 +3450,62 @@ static krb5_error_code samba_kdc_lookup_client(krb5_context context,
                        return ENOMEM;
                }
 
-               if (num_comp == 1) {
-                       size_t len;
-
-                       ret = smb_krb5_principal_get_comp_string(mem_ctx,
-                                                                context, fallback_principal, 0, &fallback_account);
-                       if (ret) {
-                               krb5_free_principal(context, fallback_principal);
-                               TALLOC_FREE(fallback_realm);
-                               return ret;
-                       }
-
-                       len = strlen(fallback_account);
-                       if (len >= 2 && fallback_account[len - 1] == '$') {
-                               TALLOC_FREE(fallback_account);
-                       }
+               ret = smb_krb5_principal_get_comp_string(mem_ctx,
+                                                        context, fallback_principal, 0, &fallback_account);
+               if (ret != 0) {
+                       krb5_free_principal(context, fallback_principal);
+                       TALLOC_FREE(fallback_realm);
+                       return ret;
                }
-               krb5_free_principal(context, fallback_principal);
-               fallback_principal = NULL;
-
-               if (fallback_account != NULL) {
-                       char *with_dollar;
 
-                       with_dollar = talloc_asprintf(mem_ctx, "%s$",
-                                                    fallback_account);
+               len = strlen(fallback_account);
+               if (len >= 2 && fallback_account[len - 1] == '$') {
+                       /* there is already a $, so no fallback */
                        TALLOC_FREE(fallback_account);
-                       if (with_dollar == NULL) {
-                               TALLOC_FREE(fallback_realm);
-                               return ENOMEM;
-                       }
-
-                       ret = smb_krb5_make_principal(context,
-                                                     &fallback_principal,
-                                                     fallback_realm,
-                                                     with_dollar, NULL);
-                       TALLOC_FREE(with_dollar);
-                       if (ret != 0) {
-                               TALLOC_FREE(fallback_realm);
-                               return ret;
-                       }
+                       TALLOC_FREE(fallback_realm);
+                       krb5_free_principal(context, fallback_principal);
+                       return SDB_ERR_NOENTRY;
                }
-               TALLOC_FREE(fallback_realm);
 
-               if (fallback_principal != NULL) {
-                       char *fallback_string = NULL;
+               krb5_free_principal(context, fallback_principal);
+               fallback_principal = NULL;
 
-                       ret = krb5_unparse_name(context,
-                                               fallback_principal,
-                                               &fallback_string);
-                       if (ret != 0) {
-                               krb5_free_principal(context, fallback_principal);
-                               return ret;
-                       }
+               with_dollar = talloc_asprintf(mem_ctx, "%s$",
+                                             fallback_account);
+               TALLOC_FREE(fallback_account);
+               if (with_dollar == NULL) {
+                       TALLOC_FREE(fallback_realm);
+                       return ENOMEM;
+               }
 
-                       nt_status = sam_get_results_principal(kdc_db_ctx->samdb,
-                                                             mem_ctx,
-                                                             fallback_string,
-                                                             attrs, dsdb_flags,
-                                                             realm_dn, msg);
-                       SAFE_FREE(fallback_string);
+               ret = smb_krb5_make_principal(context,
+                                             &fallback_principal,
+                                             fallback_realm,
+                                             with_dollar, NULL);
+               TALLOC_FREE(with_dollar);
+               TALLOC_FREE(fallback_realm);
+               if (ret != 0) {
+                       return ret;
+               }
+               if (fallback_principal == NULL) {
+                       return ENOMEM;
                }
+
+               ret = krb5_unparse_name(context,
+                                       fallback_principal,
+                                       &fallback_string);
                krb5_free_principal(context, fallback_principal);
                fallback_principal = NULL;
+               if (ret != 0) {
+                       return ret;
+               }
+
+               nt_status = sam_get_results_principal(kdc_db_ctx->samdb,
+                                                     mem_ctx,
+                                                     fallback_string,
+                                                     attrs, dsdb_flags,
+                                                     realm_dn, msg);
+               SAFE_FREE(fallback_string);
        }
        TALLOC_FREE(principal_string);