Version 1.0v1.0

* mockmta.c: Implement logging. Write pidfile, if requested.
New options: -P, -?, -v.
Various bugfixes.
* .gitignore: Update
* COPYING: New file.
* Makefile.am: Distribute COPYING; install mockmail.1
* README: New file.
* configure.ac: Organizational changes.
* mockmta.1: New file.

1 files changed, 375 insertions, 161 deletions

diff --git a/mockmta.c b/mockmta.c
index d2737fd..342f3dc 100644
--- a/mockmta.c
+++ b/mockmta.c
@@ -1,75 +1,18 @@
-/*
-  NAME
-    mockmta - mock MTA server for use in test suites
-
-  SYNOPSIS
-    mockmta [-d] [-c CERT] [-a CA] [-k KEY] [-p PORT] [-t SEC] MAILBOX
-
-  DESCRIPTION
-    Starts a mock MTA, which behaves almost identically to the real one,
-    except that it listens on localhost only and delivers all messages
-    to the given MAILBOX file.
-
-    No attempts are made to interpret the data supplied during the STMP
-    transaction, such as domain names, email addresses, etc, neither is
-    the material supplied in the DATA command verified to be a valid
-    email message.  Except for being written to MAILBOX, these data are
-    ignored.
-
-    Mockmta can work both as a foreground process and as a standalone
-    daemon.  The foreground mode can be used with GNU pies as follows:
-
-       component sm {
-           mode inetd;
-           socket inet://0.0.0.0:25;
-           command "/usr/bin/mockmta /var/spool/mail/dropmail";
-       }
-
-    When run as a daemon, mockmta starts listening on localhost port
-    PORT (default 25).
-    
-    To support TLS, the program must be compiled with the GnuTLS library.
-       
-    To enable the STARTTLS ESMTP command, supply the names of the certificate
-    (-c CERT) and certificate key (-k KEY) files.
-
-  OPTIONS
-    -a CA     Name of certificate authority file.
-    -c CERT   Name of the certificate file.
-    -d        Daemon mode.
-    -f        Remain in foreground (implies -d).
-    -k KEY    Name of the certificate key file.
-    -p PORT   Listen on this port.
-    -t SEC    Set SMTP timeout.
-
-  EXIT CODES
-    0   Success.
-    1   Failure (see stderr for details).
-    2   Timed out waiting for I/O.
-    3   Command line usage error.
-
-  BUGS
-    At most 32 RCPT commands are allowed.
-    
-  AUTHOR
-    Sergey Poznyakoff <gray@gnu.org>
-    
-  LICENSE
-    Copyright (C) 2020-2021 Free Software Foundation, Inc.
-
-    Mockmta 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.
-
-    Mockmta 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/>.
-
+/* mockmta - mock MTA server for use in test suites
+ * Copyright (C) 2020-2021 Sergey Poznyakoff
+ *
+ * Mockmta 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.
+ *
+ * Mockmta 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>
@@ -88,20 +31,20 @@
 #include <netinet/in.h>
 #include <pthread.h>
 #include <signal.h>
-#include <paths.h>
+#ifdef HAVE_PATHS_H
+# include <paths.h>
+#endif
+#ifndef _PATH_DEVNULL
+# define _PATH_DEVNULL "/dev/null"
+#endif
 
 char *progname;
 char *mailbox_name;
 int daemon_opt;
 int smtp_timeout = 5*60;
 int port = 25;
-
-int msgid = 1;
-pthread_mutex_t msgid_mutex = PTHREAD_MUTEX_INITIALIZER;
-
-#ifndef _PATH_DEVNULL
-# define _PATH_DEVNULL "/dev/null"
-#endif
+int log_level = LOG_INFO;
+char *pidfile;
 
 enum
   {
@@ -120,72 +63,193 @@ enum
     EX_USAGE
   };
 
+
+#define SID_ABC "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
+#define SID_ABC_LEN (sizeof (SID_ABC) - 1)
+#define SID_ABC_LEN_SQR (SID_ABC_LEN * SID_ABC_LEN)
+
+#define SID_BUF_LEN 9
+
+/*
+ * Generate (almost) unique session ID.  The idea borrowed from Sendmail
+ * queue ID.
+ */
+int
+generate_sid (char *sidbuf)
+{
+  static int init;
+  static unsigned int seqno = 0;
+  static pthread_mutex_t sid_mutex = PTHREAD_MUTEX_INITIALIZER;
+  static char abc[] = SID_ABC;
+  
+  struct timeval t;
+  struct tm *tm;
+  unsigned int n;
+  char *p;
+
+  gettimeofday (&t, NULL);
+
+  pthread_mutex_lock (&sid_mutex);
+  if (!init)
+    {
+      seqno = getpid () + t.tv_sec + t.tv_usec;
+      init = 1;
+    }
+  
+  n = seqno++ % SID_ABC_LEN_SQR;
+  pthread_mutex_unlock (&sid_mutex);
+  
+  tm = gmtime (&t.tv_sec);
+  sidbuf[0] = abc[tm->tm_year % SID_ABC_LEN];
+  sidbuf[1] = abc[tm->tm_mon];
+  sidbuf[2] = abc[tm->tm_mday];
+  sidbuf[3] = abc[tm->tm_hour];
+  sidbuf[4] = abc[tm->tm_min % SID_ABC_LEN];
+  sidbuf[5] = abc[tm->tm_sec % SID_ABC_LEN];
+  sidbuf[6] = abc[n / SID_ABC_LEN];
+  sidbuf[7] = abc[n % SID_ABC_LEN];
+  sidbuf[8] = 0;
+
+  p = strdup (sidbuf);
+  if (!p)
+    return errno;
+  return 0;
+}
+
+static void (*logger) (int, char const *fmt, ...);
+
+static pthread_key_t sdat_key;
+static pthread_once_t sdat_key_once = PTHREAD_ONCE_INIT;
+
+struct session_data
+{
+  char sid[SID_BUF_LEN];
+  int nomem;
+  char *fmtbuf;
+  size_t fmtsize;
+};
+
+static void
+sdat_free (void *f)
+{
+  free (f);
+}
+
+static void
+make_sdat_key (void)
+{
+  pthread_key_create (&sdat_key, sdat_free);
+}
+
+static struct session_data *
+priv_get_session_data (void)
+{
+  struct session_data *sdat;
+  pthread_once (&sdat_key_once, make_sdat_key);
+  if ((sdat = pthread_getspecific (sdat_key)) == NULL)
+    {
+      sdat = calloc (1, sizeof(*sdat));
+      if (sdat == NULL)
+	logger (LOG_CRIT, "out of memory");
+      pthread_setspecific (sdat_key, sdat);
+    }
+  return sdat;
+}
+
+static void nomemory (void);
+
 static void
-terror_stderr (char const *fmt, ...)
+log_stderr (int prio, char const *fmt, ...)
 {
   va_list ap;
   int m;
-  static char *fmtbuf = NULL;
-  static size_t fmtsize = 0;
   int ec = errno;
   char const *es = NULL;
   size_t len;
+  struct session_data *sd = priv_get_session_data ();
 
-  for (m = 0; fmt[m += strcspn (fmt + m, "%")]; )
-    {
-      m++;
-      if (fmt[m] == 'm')
-	break;
-    }      
-
-  len = strlen (fmt) + 1;
-  if (fmt[m])
-    {
-      es = strerror (ec);
-      len += strlen (es) - 2;
-    }
-  if (len > fmtsize)
+  if (prio > log_level)
+    return;
+  
+  if (!sd->nomem)
     {
-      fmtsize = len;
-      fmtbuf = realloc (fmtbuf, fmtsize);
-      if (!fmtbuf)
+      for (m = 0; fmt[m += strcspn (fmt + m, "%")]; )
 	{
-	  perror ("realloc");
-	  exit (EX_FAILURE);
+	  m++;
+	  if (fmt[m] == 'm')
+	    break;
+	}      
+      
+      len = strlen (fmt) + 1;
+      if (fmt[m])
+	{
+	  es = strerror (ec);
+	  len += strlen (es) - 2;
 	}
-    }
 
-  if (es)
-    {
-      memcpy (fmtbuf, fmt, m - 1);
-      memcpy (fmtbuf + m - 1, es, strlen (es) + 1);
-      strcat (fmtbuf, fmt + m + 1);
-    }
-  else
-    strcpy (fmtbuf, fmt);
+      if (es)
+	{
+	  if (len > sd->fmtsize)
+	    {
+	      sd->fmtsize = len;
+	      sd->fmtbuf = realloc (sd->fmtbuf, sd->fmtsize);
+	      if (!sd->fmtbuf)
+		nomemory ();
+	    }
+
+	  memcpy (sd->fmtbuf, fmt, m - 1);
+	  memcpy (sd->fmtbuf + m - 1, es, strlen (es) + 1);
+	  strcat (sd->fmtbuf, fmt + m + 1);
 
+	  fmt = sd->fmtbuf;
+	}
+    }
+  
   va_start (ap, fmt);
   fprintf (stderr, "%s: ", progname);
-  vfprintf (stderr, fmtbuf, ap);
+  if (sd->sid[0])
+    fprintf (stderr, "%s: ", sd->sid);
+  vfprintf (stderr, fmt, ap);
   fputc ('\n', stderr);
   va_end (ap);
 }
 
 static void
-terror_syslog (char const *fmt, ...)
+log_syslog (int prio, char const *fmt, ...)
 {
   va_list ap;
+  struct session_data *sd = priv_get_session_data ();
+
+  if (prio > log_level)
+    return;
+
+  if (!sd->nomem && sd->sid[0])
+    {
+      size_t len = strlen (sd->sid) + 2 + strlen (fmt) + 1;
+      if (len > sd->fmtsize)
+	{
+	  sd->fmtsize = len;
+	  sd->fmtbuf = realloc (sd->fmtbuf, sd->fmtsize);
+	  if (!sd->fmtbuf)
+	    nomemory ();
+	}
+      snprintf (sd->fmtbuf, sd->fmtsize, "%s: %s", sd->sid, fmt);
+      fmt = sd->fmtbuf;
+    }
+
   va_start (ap, fmt);
-  vsyslog (LOG_ERR, fmt, ap);
+  vsyslog (prio, fmt, ap);
   va_end (ap);
 }
 
-static void (*terror) (char const *fmt, ...) = terror_stderr;
-  
+static void (*logger) (int, char const *fmt, ...) = log_stderr;
+
 static void
 nomemory (void)
 {
-  terror ("out of memory");
+  struct session_data *sd = priv_get_session_data ();
+  sd->nomem = 1;
+  logger (LOG_CRIT, "out of memory");
   exit (EX_FAILURE);
 }
 
@@ -682,7 +746,7 @@ tls_init (void)
 						   GNUTLS_X509_FMT_PEM);
       if (rc < 0)
 	{
-	  terror ("%s: %s", tls_cafile, gnutls_strerror (rc));
+	  logger (LOG_ERR, "%s: %s", tls_cafile, gnutls_strerror (rc));
 	  return -1;
 	}
     }
@@ -692,7 +756,8 @@ tls_init (void)
 					     GNUTLS_X509_FMT_PEM);
   if (rc < 0)
     {
-      terror ("error reading certificate files: %s", gnutls_strerror (rc));
+      logger (LOG_ERR, "error reading certificate files: %s",
+	      gnutls_strerror (rc));
       return -1;
     }
   
@@ -761,7 +826,8 @@ iotls_create (int in, int out)
 }
 #else
 static inline int set_tls_opt (int c) {
-  terror ("option -%c not supported: program compiled without support for TLS",
+  logger (LOG_ERR,
+	  "option -%c not supported: program compiled without support for TLS",
 	  c);
   return 1;
 }
@@ -854,11 +920,21 @@ enum smtp_state
 
 #define MAX_RCPT 32
 
+static char *state_str[] = {
+  [STATE_ERR] = "error",
+  [STATE_INIT] = "init",
+  [STATE_EHLO] = "ehlo",
+  [STATE_MAIL] = "mail",
+  [STATE_RCPT] = "rcpt",
+  [STATE_DATA] = "data",
+  [STATE_QUIT] = "quit"
+};
+
 struct smtp
 {
   enum smtp_state state;
   struct iobase *iob;
-  unsigned sid;
+  char sid[SID_BUF_LEN];
   char buf[IOBUFSIZE];
   char *arg;
   int capa_mask;
@@ -866,7 +942,7 @@ struct smtp
   char *sender;
   char *rcpt[MAX_RCPT];
   int nrcpt;
-  int tempfd;
+  int delivered;
 };
 
 enum
@@ -884,8 +960,6 @@ static char const *capa_str[] = {
 };
 
 #define CAPA_MASK(n) (1<<(n))
-
-
 
 struct smtp *
 smtp_create (int ifd, int ofd)
@@ -902,11 +976,7 @@ smtp_create (int ifd, int ofd)
   smtp->helo = NULL;
   smtp->sender = NULL;
   smtp->nrcpt = 0;
-
-  pthread_mutex_lock (&msgid_mutex);
-  smtp->sid = msgid++;
-  pthread_mutex_unlock (&msgid_mutex);
-
+  generate_sid (smtp->sid);
   return smtp;
 }
 
@@ -937,10 +1007,11 @@ smtp_io_send (struct smtp *smtp, int code, char *fmt, ...)
   smtp_timer_enqueue (pthread_self (), SMTP_OUT);  
   if (iobase_writeln (smtp->iob, buf, n) < 0)
     {
-      terror ("iobase_writeln: %s", iobase_strerror (smtp->iob));
+      logger (LOG_ERR, "iobase_writeln: %s", iobase_strerror (smtp->iob));
       pthread_exit (NULL);
     }
   smtp_timer_dequeue (pthread_self ());  
+  logger (LOG_DEBUG, "S: %.*s", n-2, buf);
 }
 
 static void
@@ -958,10 +1029,11 @@ smtp_io_mlsend (struct smtp *smtp, int code, char const **av)
       smtp_timer_enqueue (pthread_self (), SMTP_OUT);      
       if (iobase_writeln (smtp->iob, buf, n) < 0)
 	{
-	  terror ("iobase_writeln: %s", iobase_strerror (smtp->iob));
+	  logger (LOG_ERR, "iobase_writeln: %s", iobase_strerror (smtp->iob));
 	  pthread_exit (NULL);
 	}
       smtp_timer_dequeue (pthread_self ());      
+      logger (LOG_DEBUG, "S: %.*s", n-2, buf);
     }      
 }
 
@@ -996,7 +1068,6 @@ void
 smtp_end (struct smtp *smtp)
 {
   smtp_io_send (smtp, 221, "Bye");
-  smtp_reset (smtp, STATE_INIT);
 }
 
 void
@@ -1237,7 +1308,7 @@ mailbox_append (FILE *tf)
   fd = open (mailbox_name, O_CREAT|O_WRONLY|O_APPEND, 0600);
   if (fd == -1)
     {
-      terror ("can't open %s: %s", mailbox_name, strerror (errno));
+      logger (LOG_ERR, "can't open %s: %s", mailbox_name, strerror (errno));
       return -1;
     }
   lk.l_type = F_WRLCK;
@@ -1246,7 +1317,7 @@ mailbox_append (FILE *tf)
   lk.l_len = 0;
   if (fcntl (fd, F_SETLKW, &lk)) /* FIXME: ttl */
     {
-      terror ("can't lock %s: %s", mailbox_name, strerror (errno));
+      logger (LOG_ERR, "can't lock %s: %s", mailbox_name, strerror (errno));
       close (fd);
       return -1;
     }
@@ -1256,7 +1327,7 @@ mailbox_append (FILE *tf)
   fp = fdopen (fd, "a");
   if (!fp)
     {
-      terror ("fdopen: %s", strerror (errno));
+      logger (LOG_ERR, "fdopen: %s", strerror (errno));
       close (fd);
       return -1;
     }
@@ -1276,7 +1347,7 @@ mailbox_append (FILE *tf)
   lk.l_start = 0;
   lk.l_len = 0;
   if (fcntl (fd, F_SETLK, &lk))
-    terror ("can't unlock %s: %m", mailbox_name);
+    logger (LOG_ERR, "can't unlock %s: %m", mailbox_name);
   fclose (fp);
 
   return res;
@@ -1302,7 +1373,7 @@ smtp_data (struct smtp *smtp)
   fd = mkstemp (template);
   if (fd == -1)
     {
-      terror ("can't create temporary: %m");
+      logger (LOG_ERR, "can't create temporary: %m");
       smtp_io_send (smtp, 451, "Local filesystem error");
       return -1;
     }
@@ -1310,7 +1381,7 @@ smtp_data (struct smtp *smtp)
   fp = fdopen (fd, "w+");
   if (!fp)
     {
-      terror ("fdopen: %m");
+      logger (LOG_ERR, "fdopen: %m");
       smtp_io_send (smtp, 451, "Local filesystem error");
       close (fd);
       return -1;
@@ -1335,9 +1406,10 @@ smtp_data (struct smtp *smtp)
 	{
 	  smtp->state = STATE_QUIT;
 	  if (smtp->iob->iob_eof)
-	    terror ("unexpected end of file");
+	    logger (LOG_ERR, "unexpected end of file");
 	  else
-	    terror ("read error: %s", strerror (smtp->iob->iob_errno));
+	    logger (LOG_ERR, "read error: %s",
+		    strerror (smtp->iob->iob_errno));
 	  res = 1;
 	  break;
 	}
@@ -1353,7 +1425,7 @@ smtp_data (struct smtp *smtp)
 	}
       else
 	{
-	  terror ("line too long");
+	  logger (LOG_ERR, "line too long");
 	  break;
 	}
 
@@ -1388,10 +1460,18 @@ smtp_data (struct smtp *smtp)
   
   pthread_cleanup_pop (1);
 
+  if (smtp->nrcpt > 1)
+    logger (LOG_INFO, "%s => %s (%d recipients) delivered",
+	    smtp->sender, smtp->rcpt[0], smtp->nrcpt);
+  else
+    logger (LOG_INFO, "%s => %s delivered",
+	    smtp->sender, smtp->rcpt[0]);
+    
   if (res)
     smtp_io_send (smtp, 451, "Local filesystem error");
   else
-    smtp_io_send (smtp, 250, "%x Message accepted for delivery", smtp->sid);
+    smtp_io_send (smtp, 250, "%s Message accepted for delivery", smtp->sid);
+  smtp->delivered++;
   
   return res;
 }
@@ -1453,6 +1533,7 @@ do_smtp (struct smtp *smtp)
 {
   struct smtp_transition *trans;
 
+  logger (LOG_DEBUG, "session started");
   smtp_io_send (smtp, 220, "Ready");
   while (smtp->state != STATE_QUIT)
     {
@@ -1463,6 +1544,7 @@ do_smtp (struct smtp *smtp)
       if (n <= 0)
 	break;
       smtp->buf[--n] = 0;
+      logger (LOG_DEBUG, "C: %s", smtp->buf);
       i = strcspn (smtp->buf, " \t");
       if (smtp->buf[i])
 	{
@@ -1497,6 +1579,9 @@ do_smtp (struct smtp *smtp)
 
       smtp->state = new_state;
     }
+  if (!smtp->delivered)
+    logger (LOG_NOTICE, "session ended without delivery");
+  logger (LOG_DEBUG, "session finished");
   smtp_end (smtp);
 }
 
@@ -1611,14 +1696,17 @@ thr_watcher (void *ptr)
 
 	default:
 	  /* Should not happen */
-	  terror ("unexpected error from pthread_cond_timedwait: %m");
+	  logger (LOG_ERR, "unexpected error from pthread_cond_timedwait: %m");
 	  exit (EX_FAILURE);
 	}
 
-      /* Thread I/O timed out.  Terminate the thread. */
-      pthread_cancel (timer->tid);
-      smtp_timer_unlink (timer);
-      free (timer);
+      if (timer == smtp_timer_head)
+	{
+	  /* Thread I/O timed out.  Terminate the thread. */
+	  pthread_cancel (timer->tid);
+	  smtp_timer_unlink (timer);
+	  free (timer);
+	}
     }
   pthread_mutex_unlock (&smtp_timer_mutex);
   return NULL;
@@ -1634,7 +1722,7 @@ mta_open (int port)
   fd = socket (PF_INET, SOCK_STREAM, 0);
   if (fd < 0)
     {
-      terror ("socket: %m");
+      logger (LOG_ERR, "socket: %m");
       exit (EX_FAILURE);
     }
 
@@ -1648,7 +1736,7 @@ mta_open (int port)
   if (bind (fd, (struct sockaddr *) &address, sizeof (address)) < 0)
     {
       close (fd);
-      terror ("bind: %m");
+      logger (LOG_ERR, "bind: %m");
       exit (EX_FAILURE);
     }
   
@@ -1661,12 +1749,17 @@ static void
 smtp_cleanup (void *ptr)
 {
   struct smtp *smtp = ptr;
+  if (smtp->state != STATE_QUIT)
+    logger (LOG_NOTICE, "session timed out (%s)", state_str[smtp->state]);
   smtp_free (smtp);
 }
 
 void *
 thr_smtp (void *ptr)
 {
+  struct smtp *smtp = ptr;
+  struct session_data *sd = priv_get_session_data ();
+  memcpy (sd->sid, smtp->sid, sizeof (sd->sid));
   pthread_cleanup_push (smtp_cleanup, ptr);
   do_smtp (ptr);
   pthread_cleanup_pop (1);
@@ -1689,6 +1782,8 @@ thr_smtp_stdio (void *ptr)
   return NULL;
 }
 
+#define MAX_HOST_NAME 256
+
 void *
 thr_mta_listener (void *ptr)
 {
@@ -1708,7 +1803,7 @@ thr_mta_listener (void *ptr)
       
       if ((sfd = accept (fd, (struct sockaddr *) &remote_addr, &len)) < 0)
 	{
-	  terror ("accept: %m");
+	  logger (LOG_ERR, "accept: %m");
 	  exit (EX_FAILURE);
 	}
 
@@ -1731,6 +1826,86 @@ signull(int sig)
 {
 }
 
+static void
+set_log_level (char const *arg)
+{
+  static char *logstr[] = {
+    [LOG_EMERG]   = "emerg",
+    [LOG_ALERT]   = "alert",
+    [LOG_CRIT]    = "crit",
+    [LOG_ERR]     = "err",
+    [LOG_WARNING] = "warning",
+    [LOG_NOTICE]  = "notice",
+    [LOG_INFO]    = "info",
+    [LOG_DEBUG]   = "debug",
+    NULL
+  };
+  int i;
+
+  for (i = 0; logstr[i]; i++)
+    if (strcmp (logstr[i], arg) == 0)
+      {
+	log_level = i;
+	return;
+      }
+
+  logger (LOG_CRIT, "invalid log level: %s", arg);
+  exit (EX_USAGE);
+}
+
+static char usage_help[] = "Usage: mockmta [OPTIONS] MAILBOX";
+static char prog_descr[] = "Simple MTA for testing purposes";
+static char *opthelp[] = {
+#ifdef WITH_TLS  
+  "-a CA      name of certificate authority file",
+  "-c CERT    name of the certificate file",
+#endif  
+  "-d         daemon mode",
+  "-f         remain in foreground (implies -d)",
+#ifdef WITH_TLS  
+  "-k KEY     name of the certificate key file",
+#endif  
+  "-l LEVEL   log events at the specified, or more important, loglevels",
+  "-P FILE    write PID to FILE (with -d or -f)",
+  "-p PORT    listen on this port",
+  "-t SEC     set SMTP timeout",
+  "-v         print program version and exit",
+  "-?         print this help summary and exit",
+  NULL
+};
+
+static void
+usage (FILE *fp)
+{
+  int i;
+
+  fprintf (fp, "%s\n", usage_help);
+  fprintf (fp, "%s\n", prog_descr);
+  fprintf (fp, "\nOPTIONS are:\n\n");
+  for (i = 0; opthelp[i]; i++)
+    fprintf (fp, "    %s\n", opthelp[i]);
+  fputc ('\n', fp);
+  fprintf (fp, "Report bugs to <%s>\n", PACKAGE_BUGREPORT);
+  fprintf (fp, "%s home page: <%s>\n", PACKAGE_NAME, PACKAGE_URL);
+}
+
+static int copyright_year = 2021;
+
+static void
+version (void)
+{
+  printf ("%s (%s) %s\n", progname, PACKAGE_NAME, PACKAGE_VERSION);
+  printf ("Copyright (C) %d Sergey Poznyakoff\n", copyright_year);
+  printf ("\
+License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>\nThis is free software: you are free to change and redistribute it.\n\
+There is NO WARRANTY, to the extent permitted by law.\n\
+");
+#ifdef WITH_TLS
+  printf ("\n");
+  printf ("Using GnuTLS %s\n", gnutls_check_version (NULL));
+#endif
+}
+
 int
 main (int argc, char **argv)
 {
@@ -1744,7 +1919,7 @@ main (int argc, char **argv)
   
   progname = argv[0];
   
-  while ((c = getopt (argc, argv, "a:dc:fk:p:t:")) != EOF)
+  while ((c = getopt (argc, argv, "a:dc:fk:l:P:p:t:v?")) != EOF)
     {
       switch (c)
 	{
@@ -1756,6 +1931,14 @@ main (int argc, char **argv)
 	  daemon_opt = 1;
 	  foreground = 1;
 	  break;
+
+	case 'l':
+	  set_log_level (optarg);
+	  break;
+
+	case 'P':
+	  pidfile = optarg;
+	  break;
 	  
 	case 'p':
 	  port = atoi (optarg);
@@ -1765,14 +1948,26 @@ main (int argc, char **argv)
 	  smtp_timeout = atoi (optarg);
 	  if (smtp_timeout <= 0)
 	    {
-	      terror ("invalid timeout value");
+	      logger (LOG_ERR, "invalid timeout value");
 	      exit (EX_USAGE);
 	    }
 	  break;
+
+	case 'v':
+	  version ();
+	  exit (EX_OK);
 	  
 	default:
-	  if (set_tls_opt (c))
-	    exit (EX_USAGE);
+	  if (optopt == '?')
+	    {
+	      usage (stdout);
+	      exit (EX_OK);
+	    }
+	  else if (set_tls_opt (c))
+	    {
+	      usage (stderr);
+	      exit (EX_USAGE);
+	    }
 	}
     }
 
@@ -1781,7 +1976,7 @@ main (int argc, char **argv)
 
   if (argc != 1)
     {
-      terror ("bad number of arguments");
+      usage (stderr);
       exit (EX_USAGE);
     }
 
@@ -1809,8 +2004,6 @@ main (int argc, char **argv)
   sigaddset (&sigs, SIGCHLD);
   pthread_sigmask (SIG_BLOCK, &sigs, NULL);
 
-  pthread_create (&tid, NULL, thr_watcher, NULL);
-  
   if (daemon_opt)
     {
       fd = mta_open (port);
@@ -1820,7 +2013,7 @@ main (int argc, char **argv)
 	  switch (fork ())
 	    {
 	    case -1:
-	      terror ("daemon: %m");
+	      logger (LOG_ERR, "daemon: %m");
 	      exit (EX_FAILURE);
 	      
 	    case 0:
@@ -1832,7 +2025,7 @@ main (int argc, char **argv)
 	  
 	  if (setsid () == -1)
 	    {
-	      terror ("setsid: %m");
+	      logger (LOG_ERR, "setsid: %m");
 	      exit (EX_FAILURE);
 	    }
 
@@ -1847,13 +2040,31 @@ main (int argc, char **argv)
       
 	  /* Set up logging */
 	  openlog (progname, LOG_PID, LOG_MAIL);
-	  terror = terror_syslog;
+	  logger = log_syslog;
+
+	  if (pidfile)
+	    {
+	      FILE *fp = fopen (pidfile, "w");
+	      if (fp)
+		{
+		  fprintf (fp, "%lu\n", (unsigned long) getpid());
+		  fclose (fp);
+		}
+	      else
+		{
+		  logger (LOG_ERR, "can't open pidfile %s for writing: %m",
+			  pidfile);
+		  pidfile = NULL;
+		}
+	    }
 	}
       
+      pthread_create (&tid, NULL, thr_watcher, NULL);
       pthread_create (&tid, NULL, thr_mta_listener, &fd);      
     }
   else
     {
+      pthread_create (&tid, NULL, thr_watcher, NULL);
       pthread_create (&tid, NULL, thr_smtp_stdio, smtp_create (0, 1));
       pthread_detach (tid);
     }
@@ -1867,6 +2078,9 @@ main (int argc, char **argv)
   
   /* Wait for signal to arrive */
   sigwait (&sigs, &i);
-  
+
+  if (pidfile)
+    unlink (pidfile);
+
   exit (EX_OK);
 }