Implement optional mailbox-independent locking for pop3d and imap4d.

* lib/manlock.c: New file.
* lib/Makefile.am (libmuaux_a_SOURCES): Add manlock.c.
* lib/muaux.h (manlock_mandatory_locking)
(manlock_lock_dir): New externs.
(manlock_open_mailbox, manlock_lock)
(manlock_touchlock, manlock_unlock): New protos.

* libmailutils/base/amd.c (amd_cleanup): Remove unbalanced
call to mu_locker_unlock.
* libmailutils/base/locker.c (mu_locker_create): Bugfixes.

* imap4d/imap4d.c (imap4d_cfg_param): Add mandatory-locking
construct.
(main): Call manlock_cfg_init.
* imap4d/select.c (imap4d_select0): Use mandatory locking if
the mailbox is to be opened r/w.

* imap4d/rename.c (imap4d_rename): Note FIXME!

* imap4d/bye.c: Call manlock_unlock after closing the mailbox.
* imap4d/close.c: Likewise.
* imap4d/sync.c (imap4d_sync): Call manlock_touchlock.

* pop3d/lock.c: Remove.
* pop3d/Makefile.am (pop3d_SOURCES): Remove lock.c
* pop3d/extra.c (pop3d_abquit): Unlock mailbox.
* pop3d/pop3d.c (pop3d_cfg_param): Add mandatory-locking
construct.
(main): Call manlock_cfg_init.
(pop3d_mainloop): Call manlock_touchlock.
* pop3d/pop3d.h (pop3d_lock)
(pop3d_touchlock, pop3d_unlock): Remove.
* pop3d/quit.c (pop3d_quit): Unlock the mailbox.
* pop3d/user.c (pop3d_begin_session): Use manlock_open_mailbox.

@@ -60,6 +60,7 @@ imap4d_bye0 (int reason, struct imap4d_command *command)
 	  imap4d_enter_critical ();
 	  mu_mailbox_flush (mbox, 0);
 	  mu_mailbox_close (mbox);
+	  manlock_unlock (mbox);
 	  mu_mailbox_destroy (&mbox);
 	  imap4d_leave_critical ();
 	}

@@ -50,6 +50,7 @@ imap4d_close0 (struct imap4d_command *command, imap4d_tokbuf_t tok,
       mu_diag_funcall (MU_DIAG_ERROR, "mu_mailbox_close", NULL, status);
       msg = "closing mailbox failed";
     }
+  manlock_unlock (mbox);
   mu_mailbox_destroy (&mbox);
 
   if (msg)

@@ -284,6 +284,7 @@ static struct mu_cfg_param imap4d_cfg_param[] = {
     N_("Use only encrypted ident responses.") },
   { "id-fields", MU_CFG_LIST_OF(mu_cfg_string), &imap4d_id_list, 0, NULL,
     N_("List of fields to return in response to ID command.") },
+  { "mandatory-locking", mu_cfg_section },
   { ".server", mu_cfg_section, NULL, 0, NULL,
     N_("Server configuration.") },
   { "transcript", mu_cfg_bool, &imap4d_transcript, 0, NULL,
@@ -556,6 +557,7 @@ main (int argc, char **argv)
   mu_gocs_register ("gsasl", mu_gsasl_module_init);
 #endif
   mu_tcpwrapper_cfg_init ();
+  manlock_cfg_init ();
   mu_acl_cfg_init ();
   mu_m_server_cfg_init ();
   

@@ -131,7 +131,8 @@ imap4d_rename (struct imap4d_command *command, imap4d_tokbuf_t tok)
      exist.  */
   if (stat (newname, &newst) == 0)
     {
-      if (!S_ISDIR(newst.st_mode))
+      /* FIXME: What if it's a maildir?!? */
+      if (!S_ISDIR (newst.st_mode))
 	{
 	  free (newname);
 	  return io_completion_response (command, RESP_NO,

@@ -30,7 +30,7 @@ imap4d_select (struct imap4d_command *command, imap4d_tokbuf_t tok)
 			 MU_STREAM_RDWR);
 }
 
-/* This code is share with EXAMINE.  */
+/* This code is shared with EXAMINE.  */
 int
 imap4d_select0 (struct imap4d_command *command, const char *mboxname,
 		int flags)
@@ -49,6 +49,7 @@ imap4d_select0 (struct imap4d_command *command, const char *mboxname,
       imap4d_enter_critical ();
       mu_mailbox_sync (mbox);
       mu_mailbox_close (mbox);
+      manlock_unlock (mbox);
       imap4d_leave_critical ();
       mu_mailbox_destroy (&mbox);
       /* Destroy the old uid table.  */
@@ -62,8 +63,31 @@ imap4d_select0 (struct imap4d_command *command, const char *mboxname,
   if (!mailbox_name)
     return io_completion_response (command, RESP_NO, "Couldn't open mailbox");
 
-  if ((status = mu_mailbox_create_default (&mbox, mailbox_name)) == 0
-      && (status = mu_mailbox_open (mbox, flags)) == 0)
+  if (flags & MU_STREAM_RDWR)
+    {
+      status = manlock_open_mailbox (&mbox, mailbox_name, 1, flags);
+    }
+  else
+    {
+      status = mu_mailbox_create_default (&mbox, mailbox_name);
+      if (status)
+	mu_diag_funcall (MU_DIAG_ERROR, "mu_mailbox_create_default",
+			 mailbox_name,
+			 status);
+      else
+	{
+	  status = mu_mailbox_open (mbox, flags);
+	  if (status)
+	    {
+	      mu_diag_funcall (MU_DIAG_ERROR, "mu_mailbox_open",
+			       mailbox_name,
+			       status);
+	      mu_mailbox_destroy (&mbox);
+	    }
+	}
+    }
+  
+  if (status == 0)
     {
       select_flags = flags;
       state = STATE_SEL;

@@ -187,6 +187,7 @@ imap4d_set_observer (mu_mailbox_t mbox)
 int
 imap4d_sync (void)
 {
+  manlock_touchlock (mbox);
   /* If mbox --> NULL, it means to free all the resources.
      It may be because of close or before select/examine a new mailbox.
      If it was a close we do not send any notification.  */

@@ -23,6 +23,7 @@ libmuaux_a_SOURCES += \
  argp_base.c\
  daemon.c\
  mailcap.c\
+ manlock.c\
  mu_dbm.c\
  signal.c\
  strexit.c\

+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 1999-2011 Free Software Foundation, Inc.
+
+   GNU Mailutils is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   GNU Mailutils is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+#include <stdlib.h>
+#include <string.h>
+#include <mailutils/types.h>
+#include <mailutils/errno.h>
+#include <mailutils/diag.h>
+#include <mailutils/locker.h>
+#include <mailutils/mailbox.h>
+#include <mailutils/util.h>
+#include <mailutils/url.h>
+#include <mailutils/stream.h>
+#include <mailutils/registrar.h>
+#include <mailutils/nls.h>
+#include <mailutils/cfg.h>
+#include "muaux.h"
+
+/* This file implements mandatory locking for pop3d and imap4d.  Mandatory
+   locking applies to all mailbox formats.  It is enabled by the following
+   configuration clause:
+
+   mandatory-locking {
+     enable yes;
+   }
+
+   If the underlying mailbox mechanism does not provide a locker (as is
+   the case, e.g., for maildir or MH mailboxes), a new locker object is
+   created and attached to the mailbox.  This new locker complies with
+   the "logging" configuration settings.  The name of the corresponding
+   lock file is created based on the mailbox URL.  It is created in
+   a "lock directory", which is configured by `lock-directory' clause in
+   the `mandatory-locking' block.  
+   For example, a lock file for "/var/spool/mail/g/r/gray" would
+   be "/var/lock/subsys/mail/%2Fvar%2Fspool%2Fmail%2Fg%2Fr%2Fgray.lock".
+*/
+
+int manlock_mandatory_locking;
+char *manlock_lock_dir = "/var/lock/subsys/mail";
+
+static char *
+make_locker_file_name (const char *urlstr)
+{
+  char *fname;
+  char *buf;
+  size_t size;
+  const char *p;
+  char *q;
+  static const char escapable_chars[] = "/%";
+  static const char xchr[] = "0123456789ABCDEF";
+	  
+  for (p = urlstr, size = 0; *p; p++, size++)
+    {
+      if (strchr (escapable_chars, *p))
+	size += 2;
+    }
+  
+  buf = malloc (size + 1);
+  if (!buf)
+    {
+      mu_diag_funcall (MU_DIAG_ERROR, "malloc", NULL, errno);
+      return NULL;
+    }
+	  
+  for (p = urlstr, q = buf; *p; p++)
+    {
+      if (strchr (escapable_chars, *p))
+	{
+	  unsigned char c = *p;
+	  *q++ = '%';
+	  *q++ = xchr[c >> 4];
+	  *q++ = xchr[c & 0xf];
+	}
+      else
+	*q++ = *p;
+    }
+  *q = 0;
+  
+  fname = mu_make_file_name_suf (manlock_lock_dir, buf, NULL);
+  if (!fname)
+    mu_diag_funcall (MU_DIAG_ERROR, "mu_make_file_name_suf", buf, errno);
+  free (buf);
+  return fname;
+}
+
+static int
+mailbox_open_and_lock (mu_mailbox_t mbox, int flags)
+{
+  mu_url_t url;
+  int status;
+  const char *urlstr;
+  mu_locker_t lock;
+  
+  mu_mailbox_get_url (mbox, &url);
+  urlstr = mu_url_to_string (url);
+  
+  status = mu_mailbox_get_locker (mbox, &lock);
+  if (status)
+    {
+      mu_diag_funcall (MU_DIAG_ERROR, "mu_mailbox_get_locker", urlstr, status);
+      return MU_ERR_FAILURE;
+    }
+
+  if (!lock && manlock_mandatory_locking && manlock_lock_dir)
+    {
+      char *fname = NULL;
+      int res;
+
+      if (mu_registrar_test_local_url (url, &res) == 0 && res)
+	{
+	  const char *path;
+	  status = mu_url_sget_path (url, &path);
+	  if (status == 0)
+	    fname = make_locker_file_name (path);
+	}
+      if (!fname)
+	fname = make_locker_file_name (urlstr);
+
+      if (!fname)
+	return MU_ERR_FAILURE;
+	  
+      status = mu_locker_create (&lock, fname, 0);
+      if (status)
+	{
+	  mu_diag_funcall (MU_DIAG_ERROR, "mu_locker_create", fname, status);
+	  free (fname);
+	  return MU_ERR_FAILURE;
+	}
+      mu_mailbox_set_locker (mbox, lock);
+    }
+
+  if ((status = mu_mailbox_open (mbox, flags)) != 0)
+    {
+      mu_diag_funcall (MU_DIAG_ERROR, "mu_mailbox_open", urlstr, status);
+      return MU_ERR_FAILURE;
+    }
+  return manlock_lock (mbox);
+}
+
+int
+manlock_open_mailbox (mu_mailbox_t *pmbox, const char *mailbox_name, int def,
+		      int flags)
+{
+  mu_mailbox_t mbox;
+  int status;
+
+  status = (def ? mu_mailbox_create_default : mu_mailbox_create)
+               (&mbox, mailbox_name);
+  if (status)
+    {
+      mu_diag_funcall (MU_DIAG_ERROR, "mu_mailbox_create", mailbox_name,
+		       status);
+      return 1;
+    }
+
+  status = mailbox_open_and_lock (mbox, flags);
+  
+  if (status == 0)
+    *pmbox = mbox;
+  else
+    mu_mailbox_destroy (&mbox);
+  
+  return status;
+}
+
+
+struct mu_cfg_param manlock_param[] = {
+  { "enable", mu_cfg_bool, &manlock_mandatory_locking, 0, NULL,
+    N_("Enable mandatory locking.") },
+  { "lock-directory", mu_cfg_string, &manlock_lock_dir, 0, NULL,
+    N_("Set directory for mandatory lock files.") },
+  { NULL }
+};
+
+void
+manlock_cfg_init ()
+{
+  struct mu_cfg_section *section;
+  mu_create_canned_section ("mandatory-locking", &section);
+  mu_cfg_section_add_params (section, manlock_param);
+}
+
+
+
+  
+
+int
+manlock_lock (mu_mailbox_t mbox)
+{
+  mu_url_t url = NULL;
+  mu_locker_t lock = NULL;
+  const char *name;
+  int status;
+
+  if (!manlock_mandatory_locking)
+    return 0;
+  mu_mailbox_get_url (mbox, &url);
+  name = mu_url_to_string (url);
+  mu_mailbox_get_locker (mbox, &lock);  
+  mu_locker_mod_flags (lock, MU_LOCKER_PID, mu_locker_set_bit);
+  if ((status = mu_locker_lock (lock)))
+    {
+      mu_diag_output (MU_DIAG_NOTICE, _("locking mailbox `%s' failed: %s"),
+	      name ? name : "?", mu_strerror(status));
+      return status;
+    }
+  return 0;
+}
+
+int
+manlock_touchlock (mu_mailbox_t mbox)
+{
+  if (manlock_mandatory_locking)
+    {
+      mu_locker_t lock = NULL;
+      mu_mailbox_get_locker (mbox, &lock);
+      mu_locker_touchlock (lock);
+    }
+  return 0;
+}
+
+int
+manlock_unlock (mu_mailbox_t mbox)
+{
+  if (manlock_mandatory_locking)
+    {
+      mu_locker_t lock = NULL;
+      mu_mailbox_get_locker (mbox, &lock);
+      mu_locker_unlock (lock);
+    }
+  return 0;
+}

@@ -18,3 +18,14 @@ int mu_switch_to_privs (uid_t uid, gid_t gid, mu_list_t retain_groups);
 void mu_set_signals (RETSIGTYPE (*handler) (int signo), int *sigv, int sigc);
 const char *mu_strexit (int code);
 
+extern int manlock_mandatory_locking;
+extern char *manlock_lock_dir;
+
+int manlock_open_mailbox (mu_mailbox_t *pmbox, const char *mailbox_name,
+			  int def, int flags);
+int manlock_lock (mu_mailbox_t mbox);
+int manlock_touchlock (mu_mailbox_t mbox);
+int manlock_unlock (mu_mailbox_t mbox);
+
+void manlock_cfg_init (void);
+

@@ -1361,7 +1361,6 @@ amd_cleanup (void *arg)
 {
   mu_mailbox_t mailbox = arg;
   mu_monitor_unlock (mailbox->monitor);
-  mu_locker_unlock (mailbox->locker);
 }
 
 int

@@ -453,26 +453,28 @@ mu_locker_create (mu_locker_t *plocker, const char *fname, int flags)
 	  /* Try the directory part.  If it unrolls successfully (i.e.
 	     all its components exist), tuck the filename part back in
 	     the resulting path and use it as the lock filename. */
-	  char *p, *tmp = strdup (fname);
+	  char *p, *new_name, *tmp = strdup (fname);
 	  if (!tmp)
 	    return ENOMEM;
-	  p = strchr (tmp, '/');
+	  p = strrchr (tmp, '/');
 	  if (!p)
 	    filename = tmp;
 	  else
 	    {
+	      *p = 0;
 	      err = mu_unroll_symlink (tmp, &filename);
-	      free (tmp);
 	      if (err)
-		return err;
-	      tmp = realloc (filename, strlen (filename) + strlen (p) + 1);
-	      if (!tmp)
 		{
+		  free (tmp);
+		  return err;
+		}
+
+	      new_name = mu_make_file_name_suf (filename, p + 1, NULL);
+	      free (tmp);
 	      free (filename);
+	      if (!new_name)
 		return ENOMEM;
-		}
-	      strcat (tmp, p);
-	      filename = tmp;
+	      filename = new_name;
 	    }
 	}
       else

@@ -32,7 +32,6 @@ pop3d_SOURCES =\
  expire.c\
  extra.c\
  list.c\
- lock.c\
  logindelay.c\
  noop.c\
  pop3d.c\

@@ -49,9 +49,9 @@ pop3d_abquit (int reason)
   /* Unlock spool */
   if (state != AUTHORIZATION)
     {
-      pop3d_unlock ();
       mu_mailbox_flush (mbox, 0);
       mu_mailbox_close (mbox);
+      manlock_unlock (mbox);
       mu_mailbox_destroy (&mbox);
     }
 

-/* GNU Mailutils -- a suite of utilities for electronic mail
-   Copyright (C) 1999, 2000, 2001, 2002, 2005, 2007, 2008, 2009, 2010,
-   2011 Free Software Foundation, Inc.
-
-   GNU Mailutils is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 3, or (at your option)
-   any later version.
-
-   GNU Mailutils is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>. */
-
-#include "pop3d.h"
-
-int
-pop3d_lock ()
-{
-  mu_url_t url = NULL;
-  mu_locker_t lock = NULL;
-  const char *name;
-  int status;
-
-  mu_mailbox_get_url (mbox, &url);
-  name = mu_url_to_string (url);
-  mu_mailbox_get_locker (mbox, &lock);
-  mu_locker_mod_flags (lock, MU_LOCKER_PID, mu_locker_set_bit);
-  if ((status = mu_locker_lock (lock)))
-    {
-      mu_diag_output (MU_DIAG_NOTICE, _("locking mailbox `%s' failed: %s"),
-	      name ? name : "?", mu_strerror(status));
-      return ERR_MBOX_LOCK;
-    }
-  return 0;
-}
-
-int
-pop3d_touchlock ()
-{
-  mu_locker_t lock = NULL;
-  mu_mailbox_get_locker (mbox, &lock);
-  mu_locker_touchlock (lock);
-  return 0;
-}
-
-int
-pop3d_unlock ()
-{
-  mu_locker_t lock = NULL;
-  mu_mailbox_get_locker (mbox, &lock);
-  mu_locker_unlock (lock);
-  return 0;
-}

@@ -118,6 +118,7 @@ static struct mu_cfg_param pop3d_cfg_param[] = {
 #endif
   { "output-buffer-size", mu_cfg_size, &pop3d_output_bufsize, 0, NULL,
     N_("Size of the output buffer.") },
+  { "mandatory-locking", mu_cfg_section },
   { ".server", mu_cfg_section, NULL, 0, NULL,
     N_("Server configuration.") },
   { "transcript", mu_cfg_bool, &pop3d_transcript, 0, NULL,
@@ -269,7 +270,7 @@ pop3d_mainloop (int ifd, int ofd)
 	}
 
       /* Refresh the Lock.  */
-      pop3d_touchlock ();
+      manlock_touchlock (mbox);
 
       if ((handler = pop3d_find_command (cmd)) != NULL)
 	status = handler (arg);
@@ -320,6 +321,7 @@ main (int argc, char **argv)
   mu_gocs_register ("tls", mu_tls_module_init);
 #endif /* WITH_TLS */
   mu_tcpwrapper_cfg_init ();
+  manlock_cfg_init ();
   mu_acl_cfg_init ();
   mu_m_server_cfg_init ();
   

@@ -220,7 +220,6 @@ void pop3d_send_payload (mu_stream_t stream, mu_stream_t linestr,
 extern void pop3d_bye           (void);
 extern int pop3d_abquit         (int);
 extern char *pop3d_apopuser     (const char *);
-extern int pop3d_lock           (void);
 extern void process_cleanup     (void);
 
 extern void pop3d_parse_command (char *cmd, char **pcmd, char **parg);
@@ -232,8 +231,6 @@ extern RETSIGTYPE pop3d_child_signal  (int);
 extern int pop3d_stls           (char *);
 extern void enable_stls (void);
 #endif /* WITH_TLS */
-extern int pop3d_touchlock      (void);
-extern int pop3d_unlock         (void);
 extern void pop3d_outf          (const char *fmt, ...) MU_PRINTFLIKE(1,2);
 
 extern void pop3d_setio         (int, int);

@@ -34,13 +34,13 @@ pop3d_quit (char *arg)
 
   if (state == TRANSACTION)
     {
-      pop3d_unlock ();
       pop3d_fix_mark ();
 
       if (mu_mailbox_flush (mbox, 1) != 0)
 	err = ERR_FILE;
       if (mu_mailbox_close (mbox) != 0) 
 	err = ERR_FILE;
+      manlock_unlock (mbox);
       mu_mailbox_destroy (&mbox);
       mu_diag_output (MU_DIAG_INFO, _("session ended for user: %s"), username);
     }

@@ -22,7 +22,8 @@ struct mu_auth_data *auth_data;
 int
 pop3d_begin_session ()
 {
-  int status;
+  mu_url_t url = NULL;
+  size_t total = 0;
 
   mu_diag_output (MU_DIAG_INFO, _("POP3 login: user `%s', source %s"),
 		  auth_data->name, auth_data->source);
@@ -40,19 +41,9 @@ pop3d_begin_session ()
   if (auth_data->change_uid)
     setuid (auth_data->uid);
   
-  if ((status = mu_mailbox_create (&mbox, auth_data->mailbox)) != 0
-      || (status = mu_mailbox_open (mbox, MU_STREAM_CREAT | MU_STREAM_RDWR)) != 0)
-    {
-      mu_mailbox_destroy (&mbox);
-      state = AUTHORIZATION;
-      mu_auth_data_destroy (&auth_data);
-      return ERR_MBOX_LOCK;
-    }
-  
-  if (pop3d_lock ())
+  if (manlock_open_mailbox (&mbox, auth_data->mailbox, 0,
+			    MU_STREAM_CREAT | MU_STREAM_RDWR))
     {
-      mu_mailbox_close (mbox);
-      mu_mailbox_destroy (&mbox); 
       mu_auth_data_destroy (&auth_data);
       state = AUTHORIZATION;
       return ERR_MBOX_LOCK;
@@ -70,10 +61,7 @@ pop3d_begin_session ()
 
   deliver_pending_bulletins ();
   
-  /* mailbox name */
-  {
-    mu_url_t url = NULL;
-    size_t total = 0;
+  /* log mailbox stats */
   mu_mailbox_get_url (mbox, &url);
   mu_mailbox_messages_count (mbox, &total);
   mu_diag_output (MU_DIAG_INFO,
@@ -81,7 +69,6 @@ pop3d_begin_session ()
 		      "user `%s' logged in with mailbox `%s' (%s messages)",
 		      (unsigned long) total),
 	    username, mu_url_to_string (url), mu_umaxtostr (0, total));
-  }
 
   return OK;
 }