diff -up vsftpd-3.0.2/parseconf.c.lookup vsftpd-3.0.2/parseconf.c

--- vsftpd-3.0.2/parseconf.c.lookup	2014-04-17 10:01:50.862951491 +0200

+++ vsftpd-3.0.2/parseconf.c	2014-04-17 10:02:42.343955443 +0200

@@ -91,6 +91,7 @@ parseconf_bool_array[] =

   { "mdtm_write", &tunable_mdtm_write },

   { "lock_upload_files", &tunable_lock_upload_files },

   { "pasv_addr_resolve", &tunable_pasv_addr_resolve },

+  { "reverse_lookup_enable", &tunable_reverse_lookup_enable },

   { "userlist_log", &tunable_userlist_log },

   { "debug_ssl", &tunable_debug_ssl },

   { "require_cert", &tunable_require_cert },

diff -up vsftpd-3.0.2/sysdeputil.c.lookup vsftpd-3.0.2/sysdeputil.c

--- vsftpd-3.0.2/sysdeputil.c.lookup	2014-04-17 09:57:02.111933144 +0200

+++ vsftpd-3.0.2/sysdeputil.c	2014-04-17 10:01:31.069950498 +0200

@@ -354,12 +354,16 @@ vsf_sysdep_check_auth(struct mystr* p_us

     return 0;

   }

 #ifdef PAM_RHOST

-  sin.sin_addr.s_addr = inet_addr(str_getbuf(p_remote_host));

-  host = gethostbyaddr((char*)&sin.sin_addr.s_addr,sizeof(struct in_addr),AF_INET);

-  if (host != (struct hostent*)0)

-    retval = pam_set_item(s_pamh, PAM_RHOST, host->h_name);

-  else

+  if (tunable_reverse_lookup_enable) {

+    sin.sin_addr.s_addr = inet_addr(str_getbuf(p_remote_host));

+    host = gethostbyaddr((char*)&sin.sin_addr.s_addr,sizeof(struct in_addr),AF_INET);

+    if (host != (struct hostent*)0)

+      retval = pam_set_item(s_pamh, PAM_RHOST, host->h_name);

+    else

+      retval = pam_set_item(s_pamh, PAM_RHOST, str_getbuf(p_remote_host));

+  } else {

     retval = pam_set_item(s_pamh, PAM_RHOST, str_getbuf(p_remote_host));

+  }

   if (retval != PAM_SUCCESS)

   {

     (void) pam_end(s_pamh, retval);

diff -up vsftpd-3.0.2/tunables.c.lookup vsftpd-3.0.2/tunables.c

--- vsftpd-3.0.2/tunables.c.lookup	2014-04-17 10:03:22.766958324 +0200

+++ vsftpd-3.0.2/tunables.c	2014-04-17 10:04:52.004964675 +0200

@@ -72,6 +72,7 @@ int tunable_force_anon_data_ssl;

 int tunable_mdtm_write;

 int tunable_lock_upload_files;

 int tunable_pasv_addr_resolve;

+int tunable_reverse_lookup_enable;

 int tunable_userlist_log;

 int tunable_debug_ssl;

 int tunable_require_cert;

@@ -213,6 +214,7 @@ tunables_load_defaults()

   tunable_mdtm_write = 1;

   tunable_lock_upload_files = 1;

   tunable_pasv_addr_resolve = 0;

+  tunable_reverse_lookup_enable = 1;

   tunable_userlist_log = 0;

   tunable_debug_ssl = 0;

   tunable_require_cert = 0;

diff -up vsftpd-3.0.2/tunables.h.lookup vsftpd-3.0.2/tunables.h

--- vsftpd-3.0.2/tunables.h.lookup	2014-04-17 10:03:27.405958676 +0200

+++ vsftpd-3.0.2/tunables.h	2014-04-17 10:04:22.763963824 +0200

@@ -73,6 +73,7 @@ extern int tunable_force_anon_data_ssl;

 extern int tunable_mdtm_write;                /* Allow MDTM to set timestamps */

 extern int tunable_lock_upload_files;         /* Lock uploading files */

 extern int tunable_pasv_addr_resolve;         /* DNS resolve pasv_addr */

+extern int tunable_reverse_lookup_enable;     /* Get hostname before pam auth */

 extern int tunable_userlist_log;              /* Log every failed login attempt */

 extern int tunable_debug_ssl;                 /* Verbose SSL logging */

 extern int tunable_require_cert;              /* SSL client cert required */

diff -up vsftpd-3.0.2/vsftpd.conf.5.lookup vsftpd-3.0.2/vsftpd.conf.5

--- vsftpd-3.0.2/vsftpd.conf.5.lookup	2014-04-17 10:05:30.956969003 +0200

+++ vsftpd-3.0.2/vsftpd.conf.5	2014-04-17 10:06:36.586971828 +0200

@@ -425,6 +425,15 @@ http://scarybeastsecurity.blogspot.com/2

 Default: YES

 .TP

+.B reverse_lookup_enable

+Set to YES if you want vsftpd to transform the ip address into the hostname,

+before pam authentication. This is useful if you use pam_access including the

+hostname. If you want vsftpd to run on the environment where the reverse lookup

+for some hostname is available and the name server doesn't respond for a while,

+you should set this to NO to avoid a performance issue.

+

+Default: YES

+.TP

 .B run_as_launching_user

 Set to YES if you want vsftpd to run as the user which launched vsftpd. This is

 useful where root access is not available. MASSIVE WARNING! Do NOT enable this