sdap: Skip exact duplicates when extending maps

When extending map with entry that already
exists in the map in the exacty same form,
then there is no need to fail.

We should only fail if we try to
change purpose of already used sysdb
attribute.

Resolves:
https://fedorahosted.org/sssd/ticket/3120

Signed-off-by: Lukas Slebodnik <lslebodn@redhat.com>

Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>
Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>

1 files changed, 32 insertions, 10 deletions

diff --git a/src/providers/ldap/sdap.c b/src/providers/ldap/sdap.c
index 97b8f126d..dc7d5e0ca 100644
--- a/src/providers/ldap/sdap.c
+++ b/src/providers/ldap/sdap.c
@@ -122,19 +122,30 @@ static errno_t split_extra_attr(TALLOC_CTX *mem_ctx,
     return EOK;
 }
 
-static bool is_sysdb_duplicate(struct sdap_attr_map *map,
-                               int num_entries,
-                               const char *sysdb_attr)
+enum duplicate_t {
+    NOT_FOUND = 0,
+    ALREADY_IN_MAP, /* nothing to add */
+    CONFLICT_WITH_MAP /* attempt to redefine attribute */
+};
+
+static enum duplicate_t check_duplicate(struct sdap_attr_map *map,
+                                        int num_entries,
+                                        const char *sysdb_attr,
+                                        const char *ldap_attr)
 {
     int i;
 
     for (i = 0; i < num_entries; i++) {
         if (strcmp(map[i].sys_name, sysdb_attr) == 0) {
-            return true;
+            if (strcmp(map[i].name, ldap_attr) == 0) {
+                return ALREADY_IN_MAP;
+            } else {
+                return CONFLICT_WITH_MAP;
+            }
         }
     }
 
-    return false;
+    return NOT_FOUND;
 }
 
 int sdap_extend_map(TALLOC_CTX *memctx,
@@ -167,14 +178,20 @@ int sdap_extend_map(TALLOC_CTX *memctx,
         return ENOMEM;
     }
 
-    for (i = 0; extra_attrs[i]; i++) {
-        ret = split_extra_attr(map, extra_attrs[i], &sysdb_attr, &ldap_attr);
+    for (i = 0; *extra_attrs != NULL; extra_attrs++) {
+        ret = split_extra_attr(map, *extra_attrs, &sysdb_attr, &ldap_attr);
         if (ret != EOK) {
-            DEBUG(SSSDBG_MINOR_FAILURE, "Cannot split %s\n", extra_attrs[i]);
+            DEBUG(SSSDBG_MINOR_FAILURE, "Cannot split %s\n", *extra_attrs);
             continue;
         }
 
-        if (is_sysdb_duplicate(map, num_entries, sysdb_attr)) {
+        ret = check_duplicate(map, num_entries, sysdb_attr, ldap_attr);
+        if (ret == ALREADY_IN_MAP) {
+            DEBUG(SSSDBG_TRACE_FUNC,
+                  "Attribute %s (%s in LDAP) is already in map.\n",
+                  sysdb_attr, ldap_attr);
+            continue;
+        } else if (ret == CONFLICT_WITH_MAP) {
             DEBUG(SSSDBG_FATAL_FAILURE,
                   "Attribute %s (%s in LDAP) is already used by SSSD, please "
                   "choose a different cache name\n", sysdb_attr, ldap_attr);
@@ -193,9 +210,14 @@ int sdap_extend_map(TALLOC_CTX *memctx,
             map[num_entries+i].def_name == NULL) {
             return ENOMEM;
         }
-        DEBUG(SSSDBG_TRACE_FUNC, "Extending map with %s\n", extra_attrs[i]);
+        DEBUG(SSSDBG_TRACE_FUNC, "Extending map with %s\n", *extra_attrs);
+
+        /* index must be incremented only for appended entry. */
+        i++;
     }
 
+    nextra = i;
+
     /* Sentinel */
     memset(&map[num_entries+nextra], 0, sizeof(struct sdap_attr_map));