NEX-14547 Get UNIX group info. from AD/LDAP with partial RFC2307 schema
NEX-13132 smbd dumping core in nss_ldap.so.1`getbymember
Reviewed by: Matt Barden <matt.barden@nexenta.com>
Reviewed by: Evan Layton <evan.layton@nexenta.com>

@@ -18,10 +18,11 @@
  *
  * CDDL HEADER END
  */
 /*
  * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright 2017 Nexenta Systems, Inc.  All rights reserved.
  */
 
 #include <stdio.h>
 #include <sys/types.h>
 #include <stdlib.h>

@@ -225,11 +226,12 @@
                 return (NULL);
 
         if ((rdns = ldap_explode_dn(dn, 0)) == NULL)
                 return (NULL);
 
-        for (nRdn = 0; rdns[nRdn] != NULL; nRdn++);
+        for (nRdn = 0; rdns[nRdn] != NULL; nRdn++)
+                ;
 
         if ((mapped_rdns = (char **)calloc(nRdn, sizeof (char *))) == NULL) {
                 ldap_value_free(rdns);
                 return (NULL);
         }

@@ -4228,12 +4230,91 @@
         (void) __ns_ldap_freeResult(&result);
         result = NULL;
         return (NS_LDAP_SUCCESS);
 }
 
+#define _P_UID  "uid"
+static const char *dn2uid_attrs[] = {
+        _P_CN,
+        _P_UID,
+        (char *)NULL
+};
 
 /*ARGSUSED*/
+int
+__ns_ldap_dn2uid(const char *dn,
+                char **userID,
+                const ns_cred_t *cred,  /* cred is ignored */
+                ns_ldap_error_t **errorp)
+{
+        ns_ldap_result_t        *result = NULL;
+        char            *filter, *userdata;
+        char            errstr[MAXERROR];
+        char            **value;
+        int             rc = 0;
+        size_t          len;
+
+        *errorp = NULL;
+        *userID = NULL;
+        if ((dn == NULL) || (dn[0] == '\0'))
+                return (NS_LDAP_INVALID_PARAM);
+
+        len = strlen(UIDDNFILTER) + strlen(dn) + 1;
+        filter = (char *)malloc(len);
+        if (filter == NULL) {
+                return (NS_LDAP_MEMORY);
+        }
+        (void) snprintf(filter, len, UIDDNFILTER, dn);
+
+        len = strlen(UIDDNFILTER_SSD) + strlen(dn) + 1;
+        userdata = (char *)malloc(len);
+        if (userdata == NULL) {
+                return (NS_LDAP_MEMORY);
+        }
+        (void) snprintf(userdata, len, UIDDNFILTER_SSD, dn);
+
+        /*
+         * Unlike uid2dn, we DO want attribute mapping, so that
+         * "uid" is mapped to/from samAccountName, for example.
+         */
+        rc = __ns_ldap_list("passwd", filter,
+            __s_api_merge_SSD_filter,
+            dn2uid_attrs, cred, 0,
+            &result, errorp, NULL,
+            userdata);
+        free(filter);
+        filter = NULL;
+        free(userdata);
+        userdata = NULL;
+        if (rc != NS_LDAP_SUCCESS)
+                goto out;
+
+        if (result->entries_count > 1) {
+                (void) sprintf(errstr,
+                    gettext("Too many entries are returned for %s"), dn);
+                MKERROR(LOG_WARNING, *errorp, NS_LDAP_INTERNAL, strdup(errstr),
+                    NULL);
+                rc = NS_LDAP_INTERNAL;
+                goto out;
+        }
+
+        value = __ns_ldap_getAttr(result->entry, _P_UID);
+        if (value == NULL || value[0] == NULL) {
+                rc = NS_LDAP_NOTFOUND;
+                goto out;
+        }
+
+        *userID = strdup(value[0]);
+        rc = NS_LDAP_SUCCESS;
+
+out:
+        (void) __ns_ldap_freeResult(&result);
+        result = NULL;
+        return (rc);
+}
+
+/*ARGSUSED*/
 int
 __ns_ldap_host2dn(const char *host,
                 const char *domain,
                 char **hostDN,
                 const ns_cred_t *cred,  /* cred is ignored */