diff --git a/Makefile b/Makefile
index 8b1b7b4..4c38b79 100644
--- a/Makefile
+++ b/Makefile
@@ -8,7 +8,7 @@ SHARE	:= -g $(PIC)
 
 pam_client: pam_client.c
 	$(CC) $(CFLAGS) $(SHARE) -c pam_client.c -o pam_client.o
-	$(LD_D)  -o pam_client.so pam_client.o  -lc -lpam
+	$(LD_D)  -o pam_client.so pam_client.o  -lc -lpam -lldap
 
 clean: pam_client.so pam_client.o
 	$(RM) pam_client.o
diff --git a/pam_client.c b/pam_client.c
index f6efc63..e7f1b39 100644
--- a/pam_client.c
+++ b/pam_client.c
@@ -22,14 +22,222 @@
 #include <unistd.h>
 #include <sys/types.h>
 #include <ctype.h>
+#include <syslog.h>
+#include <ldap.h>
 
 #include <asm/unistd.h>
 
-
+#define PAM_LDAP_PATH_CONF "/etc/ldap.conf"
 #define PAM_SM_AUTH
 #define MAX_V 30
 #define WAITTIME 30
 
+typedef struct pam_config
+{
+  /* file name read from */
+  char *configFile;
+  /* space delimited list of servers */
+  char *host;
+  /* port, expected to be common to all servers */
+  int port;
+  int version;
+  /* bind dn/pw for "anonymous" authentication */
+  char *binddn;
+  char *bindpw;
+
+} pam_config_t;
+
+static int
+_alloc_config (pam_config_t ** presult)
+{
+  pam_config_t *result;
+
+  if (*presult == NULL)
+  {
+    *presult = (pam_config_t *) calloc (1, sizeof (*result));
+    if (*presult == NULL)
+      return PAM_BUF_ERR;
+  }
+
+  result = *presult;
+  result->configFile = NULL;
+  result->host = NULL;
+  result->port = 0;
+  result->binddn = NULL;
+  result->bindpw = NULL;
+  result->version = LDAP_VERSION3;
+  return PAM_SUCCESS;
+}
+
+static int
+_read_config (const char *configFile, pam_config_t ** presult)
+{
+  /* this is the same configuration file as nss_ldap */
+  FILE *fp;
+  char b[BUFSIZ];
+  pam_config_t *result;
+
+  if (_alloc_config (presult) != PAM_SUCCESS)
+  {
+    return PAM_BUF_ERR;
+  }
+
+  result = *presult;
+
+  /* configuration file location is configurable; default /etc/ldap.conf */
+  if (configFile == NULL)
+  {
+    configFile = PAM_LDAP_PATH_CONF;
+    result->configFile = NULL;
+  }
+  else
+  {
+    result->configFile = strdup (configFile);
+    if (result->configFile == NULL)
+      return PAM_BUF_ERR;
+  }
+
+  fp = fopen (configFile, "r");
+
+  if (fp == NULL)
+  {
+    return PAM_SERVICE_ERR;
+  }
+
+
+  while (fgets (b, sizeof (b), fp) != NULL)
+  {
+    char *k, *v;
+    int len;
+
+    if (*b == '\n' || *b == '#')
+      continue;
+
+    k = b;
+    v = k;
+    while (*v != '\0' && *v != ' ' && *v != '\t')
+      v++;
+
+    if (*v == '\0')
+      continue;
+
+    *(v++) = '\0';
+
+    /* skip all whitespaces between keyword and value */
+    while (*v == ' ' || *v == '\t')
+      v++;
+
+    /* kick off all whitespaces and newline at the end of value */
+    len = strlen (v) - 1;
+    while (v[len] == ' ' || v[len] == '\t' || v[len] == '\n')
+      --len;
+    v[len + 1] = '\0';
+
+    if (!strcasecmp (k, "host"))
+    {
+      result->host = strdup (v);
+    }
+    else if (!strcasecmp (k, "binddn"))
+    {
+      result->binddn = strdup (v);
+    }
+    else if (!strcasecmp (k, "bindpw"))
+    {
+      result->bindpw = strdup (v);
+    }
+    else if (!strcasecmp (k, "port"))
+    {
+      result->port = atoi (v);
+    }
+    else if (!strcasecmp (k, "ldap_version"))
+    {
+      result->version = atoi (v);
+    }
+  }
+
+  if (result->host == NULL || result->binddn == NULL ||
+      result->bindpw == NULL)
+  {
+      /* 
+       * According to PAM Documentation, such an error in a config file
+       * SHOULD be logged at LOG_ALERT level
+       */
+      syslog (LOG_ALERT, "pam_ldap: missing \"host\" in file \"%s\"",
+              configFile);
+      return PAM_SERVICE_ERR;
+  }
+
+  if (result->port == 0)
+  {
+    result->port = LDAP_PORT;
+  }
+
+  fclose (fp);
+
+  /* can't use _pam_overwrite because it only goes to end of string, 
+   * not the buffer
+   */
+  memset (b, 0, BUFSIZ);
+  return PAM_SUCCESS;
+}
+
+static void
+_release_config (pam_config_t ** pconfig)
+{
+  pam_config_t *c; 
+  c = *pconfig;
+  if (c == NULL)
+    return;
+
+  if (c->configFile != NULL)
+    free (c->configFile);
+
+  if (c->host != NULL)
+    free (c->host);
+
+  if (c->binddn != NULL)
+    free (c->binddn);
+  if (c->bindpw != NULL)
+    free (c->bindpw);
+}
+
+static int
+_check_ldap (int retry_count)
+{
+  int result;
+  struct berval userpw;
+  struct berval *servcred;
+  char buf[BUFSIZ];
+  LDAP *ld;
+  pam_config_t * config= NULL;
+  if(_read_config(NULL,&config) != PAM_SUCCESS) {
+    if(config)
+      _release_config(&config);
+    return PAM_SERVICE_ERR;
+  }
+
+  snprintf(buf,BUFSIZ,"ldap://%s:%d",config->host,config->port);
+  if(ldap_initialize(&ld,buf) == LDAP_SUCCESS &&
+     ldap_set_option(ld,LDAP_OPT_PROTOCOL_VERSION,
+                     &config->version) == LDAP_SUCCESS ) {
+    userpw.bv_val = config->bindpw;
+    userpw.bv_len = (userpw.bv_val != 0) ? strlen (userpw.bv_val) : 0;
+    for(;retry_count;retry_count--) {
+      if (ldap_sasl_bind_s(ld,config->binddn,LDAP_SASL_SIMPLE,
+                           &userpw, NULL, NULL,&servcred) == LDAP_SUCCESS)  {
+        result = PAM_SUCCESS;
+        break;
+      }
+      else {
+        result = PAM_TRY_AGAIN;
+      }
+      sleep(1);
+    }
+  }
+  _release_config(&config);
+  return result;
+}
+
 int file_exists(const char *fname) {
   return access(fname, 0) != -1;
 }
@@ -47,13 +255,15 @@ PAM_EXTERN int pam_sm_authenticate(pam_handle_t * pamh, int flags
 
  // wait for client daemon
  if (file_exists(boot_client) || file_exists(default_client)) {
-	 for(i=0;i<WAITTIME;i++) {
-	     if(file_exists(started_client) || 
-	     	file_exists(started_local)) {
-	     	break;
-	     }
-	     sleep(1);
-	 }
+   for(i=0;i<WAITTIME;i++) {
+       if(file_exists(started_client) || 
+          file_exists(started_local)) {
+            if(_check_ldap(WAITTIME-i)==PAM_SUCCESS)
+                return PAM_SUCCESS;
+            break;
+       }
+       sleep(1);
+   }
  }
  // break auth if not exists ldap.conf
  if (!file_exists(ldap_conf)) {