Moved 1.9 branch to trunk

1 files changed, 1686 insertions, 0 deletions

diff --git a/agent/gpg-agent.c b/agent/gpg-agent.c
new file mode 100644
index 000000000..24e0b588b
--- /dev/null
+++ b/agent/gpg-agent.c
@@ -0,0 +1,1686 @@
+/* gpg-agent.c  -  The GnuPG Agent
+ *	Copyright (C) 2000, 2001, 2002, 2003, 2004,
+ *                    2005 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+ * USA.
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <stdarg.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <time.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#ifndef HAVE_W32_SYSTEM
+#include <sys/socket.h>
+#include <sys/un.h>
+#endif /*HAVE_W32_SYSTEM*/
+#include <unistd.h>
+#include <signal.h>
+#include <pth.h>
+
+#define JNLIB_NEED_LOG_LOGV
+#include "agent.h"
+#include <assuan.h> /* Malloc hooks */
+
+#include "i18n.h"
+#include "sysutils.h"
+#ifdef HAVE_W32_SYSTEM
+#include "../jnlib/w32-afunix.h"
+#endif
+#include "setenv.h"
+
+
+enum cmd_and_opt_values 
+{ aNull = 0,
+  oCsh		  = 'c',
+  oQuiet	  = 'q',
+  oSh		  = 's',
+  oVerbose	  = 'v',
+
+  oNoVerbose = 500,
+  aGPGConfList,
+  oOptions,
+  oDebug,
+  oDebugAll,
+  oDebugLevel,
+  oDebugWait,
+  oNoGreeting,
+  oNoOptions,
+  oHomedir,
+  oNoDetach,
+  oNoGrab,
+  oLogFile,
+  oServer,
+  oDaemon,
+  oBatch,
+
+  oPinentryProgram,
+  oDisplay,
+  oTTYname,
+  oTTYtype,
+  oLCctype,
+  oLCmessages,
+  oScdaemonProgram,
+  oDefCacheTTL,
+  oDefCacheTTLSSH,
+  oMaxCacheTTL,
+  oMaxCacheTTLSSH,
+  oUseStandardSocket,
+  oNoUseStandardSocket,
+
+  oIgnoreCacheForSigning,
+  oAllowMarkTrusted,
+  oAllowPresetPassphrase,
+  oKeepTTY,
+  oKeepDISPLAY,
+  oSSHSupport,
+  oDisableScdaemon,
+  oWriteEnvFile
+};
+
+
+
+static ARGPARSE_OPTS opts[] = {
+
+  { aGPGConfList, "gpgconf-list", 256, "@" },
+  
+  { 301, NULL, 0, N_("@Options:\n ") },
+
+  { oServer,   "server",     0, N_("run in server mode (foreground)") },
+  { oDaemon,   "daemon",     0, N_("run in daemon mode (background)") },
+  { oVerbose, "verbose",     0, N_("verbose") },
+  { oQuiet,	"quiet",     0, N_("be somewhat more quiet") },
+  { oSh,	"sh",        0, N_("sh-style command output") },
+  { oCsh,	"csh",       0, N_("csh-style command output") },
+  { oOptions, "options"  , 2, N_("|FILE|read options from FILE")},
+  { oDebug,	"debug"     ,4|16, "@"},
+  { oDebugAll, "debug-all"     ,0, "@"},
+  { oDebugLevel, "debug-level" ,2, "@"},
+  { oDebugWait,"debug-wait",1, "@"},
+  { oNoDetach, "no-detach" ,0, N_("do not detach from the console")},
+  { oNoGrab, "no-grab"     ,0, N_("do not grab keyboard and mouse")},
+  { oLogFile, "log-file"   ,2, N_("use a log file for the server")},
+  { oUseStandardSocket, "use-standard-socket", 0,
+                      N_("use a standard location for the socket")},
+  { oNoUseStandardSocket, "no-use-standard-socket", 0, "@"},
+
+  { oPinentryProgram, "pinentry-program", 2 ,
+                               N_("|PGM|use PGM as the PIN-Entry program") },
+  { oScdaemonProgram, "scdaemon-program", 2 ,
+                               N_("|PGM|use PGM as the SCdaemon program") },
+  { oDisableScdaemon, "disable-scdaemon", 0, N_("do not use the SCdaemon") },
+
+  { oDisplay,    "display",     2, "@" },
+  { oTTYname,    "ttyname",     2, "@" },
+  { oTTYtype,    "ttytype",     2, "@" },
+  { oLCctype,    "lc-ctype",    2, "@" },
+  { oLCmessages, "lc-messages", 2, "@" },
+  { oKeepTTY, "keep-tty", 0,  N_("ignore requests to change the TTY")},
+  { oKeepDISPLAY, "keep-display",
+                          0, N_("ignore requests to change the X display")},
+
+  { oDefCacheTTL, "default-cache-ttl", 4,
+                               N_("|N|expire cached PINs after N seconds")},
+  { oDefCacheTTLSSH, "default-cache-ttl-ssh", 4, "@" },
+  { oMaxCacheTTL, "max-cache-ttl", 4, "@" },
+  { oMaxCacheTTLSSH, "max-cache-ttl-ssh", 4, "@" },
+  { oIgnoreCacheForSigning, "ignore-cache-for-signing", 0,
+                               N_("do not use the PIN cache when signing")},
+  { oAllowMarkTrusted, "allow-mark-trusted", 0,
+                             N_("allow clients to mark keys as \"trusted\"")},
+  { oAllowPresetPassphrase, "allow-preset-passphrase", 0,
+                             N_("allow presetting passphrase")},
+  { oSSHSupport, "enable-ssh-support", 0, N_("enable ssh-agent emulation") },
+  { oWriteEnvFile, "write-env-file", 2|8,
+            N_("|FILE|write environment settings also to FILE")},
+  {0}
+};
+
+
+#define DEFAULT_CACHE_TTL     (10*60)  /* 10 minutes */
+#define DEFAULT_CACHE_TTL_SSH (30*60)  /* 30 minutes */
+#define MAX_CACHE_TTL         (120*60) /* 2 hours */
+
+
+/* flag to indicate that a shutdown was requested */
+static int shutdown_pending;
+
+
+/* It is possible that we are currently running under setuid permissions */
+static int maybe_setuid = 1;
+
+/* Name of the communication socket used for native gpg-agent requests.  */
+static char *socket_name;
+
+/* Name of the communication socket used for ssh-agent-emulation.  */
+static char *socket_name_ssh;
+
+/* Default values for options passed to the pinentry. */
+static char *default_display;
+static char *default_ttyname;
+static char *default_ttytype;
+static char *default_lc_ctype;
+static char *default_lc_messages;
+
+/* Name of a config file, which will be reread on a HUP if it is not NULL. */
+static char *config_filename;
+
+/* Helper to implement --debug-level */
+static const char *debug_level;
+
+/* Keep track of the current log file so that we can avoid updating
+   the log file after a SIGHUP if it didn't changed. Malloced. */
+static char *current_logfile;
+
+/* The handle_tick() function may test whether a parent is still
+   running.  We record the PID of the parent here or -1 if it should be
+   watched. */
+static pid_t parent_pid = (pid_t)(-1);
+
+
+/*
+   Local prototypes. 
+ */
+
+static char *create_socket_name (int use_standard_socket,
+                                 char *standard_name, char *template);
+static int create_server_socket (int is_standard_name, const char *name);
+static void create_directories (void);
+
+static void handle_connections (int listen_fd, int listen_fd_ssh);
+static int check_for_running_agent (int);
+
+/* Pth wrapper function definitions. */
+GCRY_THREAD_OPTION_PTH_IMPL;
+
+
+
+
+/*
+   Functions. 
+ */
+
+
+static const char *
+my_strusage (int level)
+{
+  const char *p;
+  switch (level)
+    {
+    case 11: p = "gpg-agent (GnuPG)";
+      break;
+    case 13: p = VERSION; break;
+    case 17: p = PRINTABLE_OS_NAME; break;
+    case 19: p = _("Please report bugs to <" PACKAGE_BUGREPORT ">.\n");
+      break;
+    case 1:
+    case 40: p =  _("Usage: gpg-agent [options] (-h for help)");
+      break;
+    case 41: p =  _("Syntax: gpg-agent [options] [command [args]]\n"
+                    "Secret key management for GnuPG\n");
+    break;
+    
+    default: p = NULL;
+    }
+  return p;
+}
+
+
+
+static void
+i18n_init (void)
+{
+#ifdef USE_SIMPLE_GETTEXT
+    set_gettext_file( PACKAGE_GT );
+#else
+#ifdef ENABLE_NLS
+    setlocale (LC_ALL, "");
+    bindtextdomain (PACKAGE_GT, LOCALEDIR);
+    textdomain (PACKAGE_GT);
+#endif
+#endif
+}
+
+
+
+/* Used by gcry for logging */
+static void
+my_gcry_logger (void *dummy, int level, const char *fmt, va_list arg_ptr)
+{
+  /* translate the log levels */
+  switch (level)
+    {
+    case GCRY_LOG_CONT: level = JNLIB_LOG_CONT; break;
+    case GCRY_LOG_INFO: level = JNLIB_LOG_INFO; break;
+    case GCRY_LOG_WARN: level = JNLIB_LOG_WARN; break;
+    case GCRY_LOG_ERROR:level = JNLIB_LOG_ERROR; break;
+    case GCRY_LOG_FATAL:level = JNLIB_LOG_FATAL; break;
+    case GCRY_LOG_BUG:  level = JNLIB_LOG_BUG; break;
+    case GCRY_LOG_DEBUG:level = JNLIB_LOG_DEBUG; break;
+    default:            level = JNLIB_LOG_ERROR; break;  
+    }
+  log_logv (level, fmt, arg_ptr);
+}
+
+
+/* Setup the debugging.  With the global variable DEBUG_LEVEL set to NULL
+   only the active debug flags are propagated to the subsystems.  With
+   DEBUG_LEVEL set, a specific set of debug flags is set; thus overriding
+   all flags already set. Note that we don't fail here, because it is
+   important to keep gpg-agent running even after re-reading the
+   options due to a SIGHUP. */
+static void
+set_debug (void)
+{
+  if (!debug_level)
+    ;
+  else if (!strcmp (debug_level, "none"))
+    opt.debug = 0;
+  else if (!strcmp (debug_level, "basic"))
+    opt.debug = DBG_ASSUAN_VALUE;
+  else if (!strcmp (debug_level, "advanced"))
+    opt.debug = DBG_ASSUAN_VALUE|DBG_COMMAND_VALUE;
+  else if (!strcmp (debug_level, "expert"))
+    opt.debug = (DBG_ASSUAN_VALUE|DBG_COMMAND_VALUE
+                 |DBG_CACHE_VALUE);
+  else if (!strcmp (debug_level, "guru"))
+    opt.debug = ~0;
+  else
+    {
+      log_error (_("invalid debug-level `%s' given\n"), debug_level);
+      opt.debug = 0; /* Reset debugging, so that prior debug
+                        statements won't have an undesired effect. */
+    }
+
+  if (opt.debug && !opt.verbose)
+    opt.verbose = 1;
+  if (opt.debug && opt.quiet)
+    opt.quiet = 0;
+
+  if (opt.debug & DBG_MPI_VALUE)
+    gcry_control (GCRYCTL_SET_DEBUG_FLAGS, 2);
+  if (opt.debug & DBG_CRYPTO_VALUE )
+    gcry_control (GCRYCTL_SET_DEBUG_FLAGS, 1);
+  gcry_control (GCRYCTL_SET_VERBOSITY, (int)opt.verbose);
+}
+ 
+
+/* Helper for cleanup to remove one socket with NAME.  */
+static void
+remove_socket (char *name)
+{
+  if (name && *name)
+    {
+      char *p;
+
+      remove (name);
+      p = strrchr (name, '/');
+      if (p)
+	{
+	  *p = 0;
+	  rmdir (name);
+	  *p = '/';
+	}
+      *name = 0;
+    }
+}  
+
+static void
+cleanup (void)
+{
+  remove_socket (socket_name);
+  remove_socket (socket_name_ssh);
+}
+
+
+
+/* Handle options which are allowed to be reset after program start.
+   Return true when the current option in PARGS could be handled and
+   false if not.  As a special feature, passing a value of NULL for
+   PARGS, resets the options to the default.  REREAD should be set
+   true if it is not the initial option parsing. */
+static int
+parse_rereadable_options (ARGPARSE_ARGS *pargs, int reread)
+{
+  if (!pargs)
+    { /* reset mode */
+      opt.quiet = 0;
+      opt.verbose = 0;
+      opt.debug = 0;
+      opt.no_grab = 0;
+      opt.pinentry_program = NULL;
+      opt.scdaemon_program = NULL;
+      opt.def_cache_ttl = DEFAULT_CACHE_TTL;
+      opt.def_cache_ttl_ssh = DEFAULT_CACHE_TTL_SSH;
+      opt.max_cache_ttl = MAX_CACHE_TTL;
+      opt.max_cache_ttl_ssh = MAX_CACHE_TTL;
+      opt.ignore_cache_for_signing = 0;
+      opt.allow_mark_trusted = 0;
+      opt.disable_scdaemon = 0;
+      return 1;
+    }
+
+  switch (pargs->r_opt)
+    {
+    case oQuiet: opt.quiet = 1; break;
+    case oVerbose: opt.verbose++; break;
+
+    case oDebug: opt.debug |= pargs->r.ret_ulong; break;
+    case oDebugAll: opt.debug = ~0; break;
+    case oDebugLevel: debug_level = pargs->r.ret_str; break;
+
+    case oLogFile:
+      if (!reread)
+        return 0; /* not handeld */
+      if (!current_logfile || !pargs->r.ret_str
+          || strcmp (current_logfile, pargs->r.ret_str))
+        {
+          log_set_file (pargs->r.ret_str);
+          xfree (current_logfile);
+          current_logfile = xtrystrdup (pargs->r.ret_str);
+        }
+      break;
+
+    case oNoGrab: opt.no_grab = 1; break;
+      
+    case oPinentryProgram: opt.pinentry_program = pargs->r.ret_str; break;
+    case oScdaemonProgram: opt.scdaemon_program = pargs->r.ret_str; break;
+    case oDisableScdaemon: opt.disable_scdaemon = 1; break;
+
+    case oDefCacheTTL: opt.def_cache_ttl = pargs->r.ret_ulong; break;
+    case oDefCacheTTLSSH: opt.def_cache_ttl_ssh = pargs->r.ret_ulong; break;
+    case oMaxCacheTTL: opt.max_cache_ttl = pargs->r.ret_ulong; break;
+    case oMaxCacheTTLSSH: opt.max_cache_ttl_ssh = pargs->r.ret_ulong; break;
+      
+    case oIgnoreCacheForSigning: opt.ignore_cache_for_signing = 1; break;
+
+    case oAllowMarkTrusted: opt.allow_mark_trusted = 1; break;
+
+    case oAllowPresetPassphrase: opt.allow_preset_passphrase = 1; break;
+
+    default:
+      return 0; /* not handled */
+    }
+
+  return 1; /* handled */
+}
+
+
+int
+main (int argc, char **argv )
+{
+  ARGPARSE_ARGS pargs;
+  int orig_argc;
+  int may_coredump;
+  char **orig_argv;
+  FILE *configfp = NULL;
+  char *configname = NULL;
+  const char *shell;
+  unsigned configlineno;
+  int parse_debug = 0;
+  int default_config =1;
+  int greeting = 0;
+  int nogreeting = 0;
+  int pipe_server = 0;
+  int is_daemon = 0;
+  int nodetach = 0;
+  int csh_style = 0;
+  char *logfile = NULL;
+  int debug_wait = 0;
+  int gpgconf_list = 0;
+  int standard_socket = 0;
+  gpg_error_t err;
+  const char *env_file_name = NULL;
+
+  set_strusage (my_strusage);
+  gcry_control (GCRYCTL_SUSPEND_SECMEM_WARN);
+  /* Please note that we may running SUID(ROOT), so be very CAREFUL
+     when adding any stuff between here and the call to INIT_SECMEM()
+     somewhere after the option parsing */
+  log_set_prefix ("gpg-agent", JNLIB_LOG_WITH_PREFIX|JNLIB_LOG_WITH_PID); 
+
+  /* Try to auto set the character set.  */
+  set_native_charset (NULL); 
+
+  i18n_init ();
+
+  /* Libgcrypt requires us to register the threading model first.
+     Note that this will also do the pth_init. */
+  err = gcry_control (GCRYCTL_SET_THREAD_CBS, &gcry_threads_pth);
+  if (err)
+    {
+      log_fatal ("can't register GNU Pth with Libgcrypt: %s\n",
+                 gpg_strerror (err));
+    }
+
+
+  /* Check that the libraries are suitable.  Do it here because
+     the option parsing may need services of the library. */
+  if (!gcry_check_version (NEED_LIBGCRYPT_VERSION) )
+    {
+      log_fatal( _("libgcrypt is too old (need %s, have %s)\n"),
+                 NEED_LIBGCRYPT_VERSION, gcry_check_version (NULL) );
+    }
+
+  assuan_set_malloc_hooks (gcry_malloc, gcry_realloc, gcry_free);
+  assuan_set_assuan_log_stream (log_get_stream ());
+  assuan_set_assuan_log_prefix (log_get_prefix (NULL));
+
+  gcry_set_log_handler (my_gcry_logger, NULL);
+  gcry_control (GCRYCTL_USE_SECURE_RNDPOOL);
+
+  may_coredump = disable_core_dumps ();
+
+  /* Set default options.  */
+  parse_rereadable_options (NULL, 0); /* Reset them to default values. */
+#ifdef HAVE_W32_SYSTEM
+  standard_socket = 1;  /* Under Windows we always use a standard
+                           socket.  */
+#endif
+  
+  shell = getenv ("SHELL");
+  if (shell && strlen (shell) >= 3 && !strcmp (shell+strlen (shell)-3, "csh") )
+    csh_style = 1;
+
+  opt.homedir = default_homedir ();
+
+  /* Record some of the original environment strings. */
+  opt.startup_display = getenv ("DISPLAY");
+  if (opt.startup_display)
+    opt.startup_display = xstrdup (opt.startup_display);
+  opt.startup_ttyname = ttyname (0);
+  if (opt.startup_ttyname)
+    opt.startup_ttyname = xstrdup (opt.startup_ttyname);
+  opt.startup_ttytype = getenv ("TERM");
+  if (opt.startup_ttytype)
+    opt.startup_ttytype = xstrdup (opt.startup_ttytype);
+  /* Fixme: Better use the locale function here.  */
+  opt.startup_lc_ctype = getenv ("LC_CTYPE");
+  if (opt.startup_lc_ctype) 
+    opt.startup_lc_ctype = xstrdup (opt.startup_lc_ctype);
+  opt.startup_lc_messages = getenv ("LC_MESSAGES");
+  if (opt.startup_lc_messages)
+    opt.startup_lc_messages = xstrdup (opt.startup_lc_messages);
+
+  /* Check whether we have a config file on the commandline */
+  orig_argc = argc;
+  orig_argv = argv;
+  pargs.argc = &argc;
+  pargs.argv = &argv;
+  pargs.flags= 1|(1<<6);  /* do not remove the args, ignore version */
+  while (arg_parse( &pargs, opts))
+    {
+      if (pargs.r_opt == oDebug || pargs.r_opt == oDebugAll)
+        parse_debug++;
+      else if (pargs.r_opt == oOptions)
+        { /* yes there is one, so we do not try the default one, but
+	     read the option file when it is encountered at the
+	     commandline */
+          default_config = 0;
+	}
+	else if (pargs.r_opt == oNoOptions)
+          default_config = 0; /* --no-options */
+	else if (pargs.r_opt == oHomedir)
+          opt.homedir = pargs.r.ret_str;
+    }
+
+  /* initialize the secure memory. */
+  gcry_control (GCRYCTL_INIT_SECMEM, 16384, 0);
+  maybe_setuid = 0;
+
+  /* 
+     Now we are now working under our real uid 
+  */
+
+  if (default_config)
+    configname = make_filename (opt.homedir, "gpg-agent.conf", NULL );
+  
+  argc = orig_argc;
+  argv = orig_argv;
+  pargs.argc = &argc;
+  pargs.argv = &argv;
+  pargs.flags=  1;  /* do not remove the args */
+ next_pass:
+  if (configname)
+    {
+      configlineno = 0;
+      configfp = fopen (configname, "r");
+      if (!configfp)
+        {
+          if (default_config)
+            {
+              if( parse_debug )
+                log_info (_("NOTE: no default option file `%s'\n"),
+                          configname );
+	    }
+          else
+            {
+              log_error (_("option file `%s': %s\n"),
+                         configname, strerror(errno) );
+              exit(2);
+	    }
+          xfree (configname); 
+          configname = NULL;
+	}
+      if (parse_debug && configname )
+        log_info (_("reading options from `%s'\n"), configname );
+      default_config = 0;
+    }
+
+  while (optfile_parse( configfp, configname, &configlineno, &pargs, opts) )
+    {
+      if (parse_rereadable_options (&pargs, 0))
+        continue; /* Already handled */
+      switch (pargs.r_opt)
+        {
+        case aGPGConfList: gpgconf_list = 1; break;
+        case oBatch: opt.batch=1; break;
+
+        case oDebugWait: debug_wait = pargs.r.ret_int; break;
+
+        case oOptions:
+          /* config files may not be nested (silently ignore them) */
+          if (!configfp)
+            {
+		xfree(configname);
+		configname = xstrdup(pargs.r.ret_str);
+		goto next_pass;
+	    }
+          break;
+        case oNoGreeting: nogreeting = 1; break;
+        case oNoVerbose: opt.verbose = 0; break;
+        case oNoOptions: break; /* no-options */
+        case oHomedir: opt.homedir = pargs.r.ret_str; break;
+        case oNoDetach: nodetach = 1; break;
+        case oLogFile: logfile = pargs.r.ret_str; break;
+        case oCsh: csh_style = 1; break;
+        case oSh: csh_style = 0; break;
+        case oServer: pipe_server = 1; break;
+        case oDaemon: is_daemon = 1; break;
+
+        case oDisplay: default_display = xstrdup (pargs.r.ret_str); break;
+        case oTTYname: default_ttyname = xstrdup (pargs.r.ret_str); break;
+        case oTTYtype: default_ttytype = xstrdup (pargs.r.ret_str); break;
+        case oLCctype: default_lc_ctype = xstrdup (pargs.r.ret_str); break;
+        case oLCmessages: default_lc_messages = xstrdup (pargs.r.ret_str);
+          break;
+
+        case oUseStandardSocket: standard_socket = 1; break;
+        case oNoUseStandardSocket: standard_socket = 0; break;
+
+        case oKeepTTY: opt.keep_tty = 1; break;
+        case oKeepDISPLAY: opt.keep_display = 1; break;
+
+	case oSSHSupport:  opt.ssh_support = 1; break;
+        case oWriteEnvFile:
+          if (pargs.r_type)
+            env_file_name = pargs.r.ret_str;
+          else
+            env_file_name = make_filename ("~/.gpg-agent-info", NULL);
+          break;
+
+        default : pargs.err = configfp? 1:2; break;
+	}
+    }
+  if (configfp)
+    {
+      fclose( configfp );
+      configfp = NULL;
+      /* Keep a copy of the name so that it can be read on SIGHUP. */
+      config_filename = configname;
+      configname = NULL;
+      goto next_pass;
+    }
+  xfree (configname);
+  configname = NULL;
+  if (log_get_errorcount(0))
+    exit(2);
+  if (nogreeting )
+    greeting = 0;
+
+  if (greeting)
+    {
+      fprintf (stderr, "%s %s; %s\n",
+                 strusage(11), strusage(13), strusage(14) );
+      fprintf (stderr, "%s\n", strusage(15) );
+    }
+#ifdef IS_DEVELOPMENT_VERSION
+  /* We don't want to print it here because gpg-agent is useful of its
+     own and quite matured.  */
+  /*log_info ("NOTE: this is a development version!\n");*/
+#endif
+
+  set_debug ();
+  
+  if (atexit (cleanup))
+    {
+      log_error ("atexit failed\n");
+      cleanup ();
+      exit (1);
+    }
+
+  initialize_module_query ();
+  initialize_module_call_scd ();
+  
+  /* Try to create missing directories. */
+  create_directories ();
+
+  if (debug_wait && pipe_server)
+    {
+      log_debug ("waiting for debugger - my pid is %u .....\n",
+                 (unsigned int)getpid());
+      sleep (debug_wait);
+      log_debug ("... okay\n");
+    }
+  
+  if (gpgconf_list)
+    {
+      char *filename;
+
+      /* List options and default values in the GPG Conf format.  */
+
+      /* The following list is taken from gnupg/tools/gpgconf-comp.c.  */
+      /* Option flags.  YOU MUST NOT CHANGE THE NUMBERS OF THE EXISTING
+         FLAGS, AS THEY ARE PART OF THE EXTERNAL INTERFACE.  */
+#define GC_OPT_FLAG_NONE	0UL
+      /* The RUNTIME flag for an option indicates that the option can be
+         changed at runtime.  */
+#define GC_OPT_FLAG_RUNTIME	(1UL << 3)
+      /* The DEFAULT flag for an option indicates that the option has a
+         default value.  */
+#define GC_OPT_FLAG_DEFAULT	(1UL << 4)
+      /* The DEF_DESC flag for an option indicates that the option has a
+         default, which is described by the value of the default field.  */
+#define GC_OPT_FLAG_DEF_DESC	(1UL << 5)
+      /* The NO_ARG_DESC flag for an option indicates that the argument has
+         a default, which is described by the value of the ARGDEF field.  */
+#define GC_OPT_FLAG_NO_ARG_DESC	(1UL << 6)
+
+      filename = make_filename (opt.homedir, "gpg-agent.conf", NULL );
+      printf ("gpgconf-gpg-agent.conf:%lu:\"%s\n",
+              GC_OPT_FLAG_DEFAULT, filename);
+      xfree (filename);
+
+      printf ("verbose:%lu:\n"
+              "quiet:%lu:\n"
+              "debug-level:%lu:\"none:\n"
+              "log-file:%lu:\n",
+              GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME,
+              GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME,
+              GC_OPT_FLAG_DEFAULT|GC_OPT_FLAG_RUNTIME,
+              GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME );
+      printf ("default-cache-ttl:%lu:%d:\n",
+              GC_OPT_FLAG_DEFAULT|GC_OPT_FLAG_RUNTIME, DEFAULT_CACHE_TTL );
+      printf ("no-grab:%lu:\n", 
+              GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME);
+      printf ("ignore-cache-for-signing:%lu:\n",
+              GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME);
+      printf ("allow-mark-trusted:%lu:\n",
+              GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME);
+      printf ("disable-scdaemon:%lu:\n",
+              GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME);
+
+      agent_exit (0);
+    }
+
+  /* If this has been called without any options, we merely check
+     whether an agent is already running.  We do this here so that we
+     don't clobber a logfile but print it directly to stderr. */
+  if (!pipe_server && !is_daemon)
+    {
+      log_set_prefix (NULL, JNLIB_LOG_WITH_PREFIX); 
+      check_for_running_agent (0);
+      agent_exit (0);
+    }
+  
+#ifdef ENABLE_NLS
+  /* gpg-agent usually does not output any messages because it runs in
+     the background.  For log files it is acceptable to have messages
+     always encoded in utf-8.  We switch here to utf-8, so that
+     commands like --help still give native messages.  It is far
+     easier to switch only once instead of for every message and it
+     actually helps when more then one thread is active (avoids an
+     extra copy step). */
+    bind_textdomain_codeset (PACKAGE_GT, "UTF-8");
+#endif
+
+  /* Now start with logging to a file if this is desired. */
+  if (logfile)
+    {
+      log_set_file (logfile);
+      log_set_prefix (NULL, (JNLIB_LOG_WITH_PREFIX
+                             |JNLIB_LOG_WITH_TIME
+                             |JNLIB_LOG_WITH_PID));
+      current_logfile = xstrdup (logfile);
+    }
+
+  /* Make sure that we have a default ttyname. */
+  if (!default_ttyname && ttyname (1))
+    default_ttyname = xstrdup (ttyname (1));
+  if (!default_ttytype && getenv ("TERM"))
+    default_ttytype = xstrdup (getenv ("TERM"));
+
+
+  if (pipe_server)
+    { /* this is the simple pipe based server */
+      start_command_handler (-1, -1);
+    }
+  else if (!is_daemon)
+    ; /* NOTREACHED */
+  else
+    { /* Regular server mode */
+      int fd;
+      int fd_ssh;
+      pid_t pid;
+
+      /* Remove the DISPLAY variable so that a pinentry does not
+         default to a specific display.  There is still a default
+         display when gpg-agent was started using --display or a
+         client requested this using an OPTION command.  Note, that we
+         don't do this when running in reverse daemon mode (i.e. when
+         exec the program given as arguments). */
+#ifndef HAVE_W32_SYSTEM
+      if (!opt.keep_display && !argc)
+        unsetenv ("DISPLAY");
+#endif
+
+
+      /* Create the sockets.  */
+      socket_name = create_socket_name (standard_socket,
+                                        "S.gpg-agent",
+                                        "/tmp/gpg-XXXXXX/S.gpg-agent");
+      if (opt.ssh_support)
+	socket_name_ssh = create_socket_name (standard_socket, 
+                                            "S.gpg-agent.ssh",
+                                            "/tmp/gpg-XXXXXX/S.gpg-agent.ssh");
+
+      fd = create_server_socket (standard_socket, socket_name);
+      if (opt.ssh_support)
+	fd_ssh = create_server_socket (standard_socket, socket_name_ssh);
+      else
+	fd_ssh = -1;
+
+      /* If we are going to exec a program in the parent, we record
+         the PID, so that the child may check whether the program is
+         still alive. */
+      if (argc)
+        parent_pid = getpid ();
+
+      fflush (NULL);
+#ifdef HAVE_W32_SYSTEM
+      pid = getpid ();
+      printf ("set GPG_AGENT_INFO=%s;%lu;1\n", socket_name, (ulong)pid);
+#else /*!HAVE_W32_SYSTEM*/
+      pid = fork ();
+      if (pid == (pid_t)-1) 
+        {
+          log_fatal ("fork failed: %s\n", strerror (errno) );
+          exit (1);
+        }
+      else if (pid) 
+        { /* We are the parent */
+          char *infostr, *infostr_ssh_sock, *infostr_ssh_pid;
+          
+          close (fd);
+          
+          /* Create the info string: <name>:<pid>:<protocol_version> */
+          if (asprintf (&infostr, "GPG_AGENT_INFO=%s:%lu:1",
+                        socket_name, (ulong)pid ) < 0)
+            {
+              log_error ("out of core\n");
+              kill (pid, SIGTERM);
+              exit (1);
+            }
+	  if (opt.ssh_support)
+	    {
+	      if (asprintf (&infostr_ssh_sock, "SSH_AUTH_SOCK=%s",
+			    socket_name_ssh) < 0)
+		{
+		  log_error ("out of core\n");
+		  kill (pid, SIGTERM);
+		  exit (1);
+		}
+	      if (asprintf (&infostr_ssh_pid, "SSH_AGENT_PID=%u",
+			    pid) < 0)
+		{
+		  log_error ("out of core\n");
+		  kill (pid, SIGTERM);
+		  exit (1);
+		}
+	    }
+
+          *socket_name = 0; /* Don't let cleanup() remove the socket -
+                               the child should do this from now on */
+	  if (opt.ssh_support)
+	    *socket_name_ssh = 0;
+
+          if (env_file_name)
+            {
+              FILE *fp;
+              
+              fp = fopen (env_file_name, "w");
+              if (!fp)
+                log_error (_("error creating `%s': %s\n"),
+                             env_file_name, strerror (errno));
+              else
+                {
+                  fputs (infostr, fp);
+                  putc ('\n', fp);
+                  if (opt.ssh_support)
+                    {
+                      fputs (infostr_ssh_sock, fp);
+                      putc ('\n', fp);
+                      fputs (infostr_ssh_pid, fp);
+                      putc ('\n', fp);
+                    }
+                  fclose (fp);
+                }
+            }
+
+
+          if (argc) 
+            { /* Run the program given on the commandline.  */
+              if (putenv (infostr))
+                {
+                  log_error ("failed to set environment: %s\n",
+                             strerror (errno) );
+                  kill (pid, SIGTERM );
+                  exit (1);
+                }
+              if (opt.ssh_support && putenv (infostr_ssh_sock))
+                {
+                  log_error ("failed to set environment: %s\n",
+                             strerror (errno) );
+                  kill (pid, SIGTERM );
+                  exit (1);
+                }
+              if (opt.ssh_support && putenv (infostr_ssh_pid))
+                {
+                  log_error ("failed to set environment: %s\n",
+                             strerror (errno) );
+                  kill (pid, SIGTERM );
+                  exit (1);
+                }
+              execvp (argv[0], argv);
+              log_error ("failed to run the command: %s\n", strerror (errno));
+              kill (pid, SIGTERM);
+              exit (1);
+            }
+          else
+            {
+              /* Print the environment string, so that the caller can use
+                 shell's eval to set it */
+              if (csh_style)
+                {
+                  *strchr (infostr, '=') = ' ';
+                  printf ("setenv %s\n", infostr);
+		  if (opt.ssh_support)
+		    {
+		      *strchr (infostr_ssh_sock, '=') = ' ';
+		      printf ("setenv %s\n", infostr_ssh_sock);
+		      *strchr (infostr_ssh_pid, '=') = ' ';
+		      printf ("setenv %s\n", infostr_ssh_pid);
+		    }
+                }
+              else
+                {
+                  printf ( "%s; export GPG_AGENT_INFO;\n", infostr);
+		  if (opt.ssh_support)
+		    {
+		      printf ("%s; export SSH_AUTH_SOCK;\n", infostr_ssh_sock);
+		      printf ("%s; export SSH_AGENT_PID;\n", infostr_ssh_pid);
+		    }
+                }
+              free (infostr); /* (Note that a vanilla free is here correct.) */
+	      if (opt.ssh_support)
+		{
+		  free (infostr_ssh_sock);
+		  free (infostr_ssh_pid);
+		}
+              exit (0); 
+            }
+          /*NOTREACHED*/
+        } /* End parent */
+
+      /* 
+         This is the child
+       */
+
+      /* Detach from tty and put process into a new session */
+      if (!nodetach )
+        { 
+          int i;
+          unsigned int oldflags;
+
+          /* Close stdin, stdout and stderr unless it is the log stream */
+          for (i=0; i <= 2; i++) 
+            {
+              if (!log_test_fd (i) && i != fd )
+                close (i);
+            }
+          if (setsid() == -1)
+            {
+              log_error ("setsid() failed: %s\n", strerror(errno) );
+              cleanup ();
+              exit (1);
+            }
+
+          log_get_prefix (&oldflags);
+          log_set_prefix (NULL, oldflags | JNLIB_LOG_RUN_DETACHED);
+          opt.running_detached = 1;
+        }
+
+      if (chdir("/"))
+        {
+          log_error ("chdir to / failed: %s\n", strerror (errno));
+          exit (1);
+        }
+
+      {
+        struct sigaction sa;
+        
+        sa.sa_handler = SIG_IGN;
+        sigemptyset (&sa.sa_mask);
+        sa.sa_flags = 0;
+        sigaction (SIGPIPE, &sa, NULL);
+      }
+#endif /*!HAVE_W32_SYSTEM*/
+
+      handle_connections (fd, opt.ssh_support ? fd_ssh : -1);
+      close (fd);
+    }
+  
+  return 0;
+}
+
+void
+agent_exit (int rc)
+{
+  /*FIXME: update_random_seed_file();*/
+#if 1
+  /* at this time a bit annoying */
+  if (opt.debug & DBG_MEMSTAT_VALUE)
+    {
+      gcry_control( GCRYCTL_DUMP_MEMORY_STATS );
+      gcry_control( GCRYCTL_DUMP_RANDOM_STATS );
+    }
+  if (opt.debug)
+    gcry_control (GCRYCTL_DUMP_SECMEM_STATS );
+#endif
+  gcry_control (GCRYCTL_TERM_SECMEM );
+  rc = rc? rc : log_get_errorcount(0)? 2 : 0;
+  exit (rc);
+}
+
+
+void
+agent_init_default_ctrl (struct server_control_s *ctrl)
+{
+  ctrl->connection_fd = -1;
+
+  /* Note we ignore malloc errors because we can't do much about it
+     and the request will fail anyway shortly after this
+     initialization. */
+  if (ctrl->display)
+    free (ctrl->display);
+  ctrl->display = default_display? strdup (default_display) : NULL;
+
+  if (ctrl->ttyname)
+    free (ctrl->ttyname);
+  ctrl->ttyname = default_ttyname? strdup (default_ttyname) : NULL;
+
+  if (ctrl->ttytype)
+    free (ctrl->ttytype);
+  ctrl->ttytype = default_ttytype? strdup (default_ttytype) : NULL;
+
+  if (ctrl->lc_ctype)
+    free (ctrl->lc_ctype);
+  ctrl->lc_ctype = default_lc_ctype? strdup (default_lc_ctype) : NULL;
+
+  if (ctrl->lc_messages)
+    free (ctrl->lc_messages);
+  ctrl->lc_messages = default_lc_messages? strdup (default_lc_messages) : NULL;
+}
+
+
+/* Reread parts of the configuration.  Note, that this function is
+   obviously not thread-safe and should only be called from the PTH
+   signal handler. 
+
+   Fixme: Due to the way the argument parsing works, we create a
+   memory leak here for all string type arguments.  There is currently
+   no clean way to tell whether the memory for the argument has been
+   allocated or points into the process' original arguments.  Unless
+   we have a mechanism to tell this, we need to live on with this. */
+static void
+reread_configuration (void)
+{
+  ARGPARSE_ARGS pargs;
+  FILE *fp;
+  unsigned int configlineno = 0;
+  int dummy;
+
+  if (!config_filename)
+    return; /* No config file. */
+
+  fp = fopen (config_filename, "r");
+  if (!fp)
+    {
+      log_error (_("option file `%s': %s\n"),
+                 config_filename, strerror(errno) );
+      return;
+    }
+
+  parse_rereadable_options (NULL, 1); /* Start from the default values. */
+
+  memset (&pargs, 0, sizeof pargs);
+  dummy = 0;
+  pargs.argc = &dummy;
+  pargs.flags = 1;  /* do not remove the args */
+  while (optfile_parse (fp, config_filename, &configlineno, &pargs, opts) )
+    {
+      if (pargs.r_opt < -1)
+        pargs.err = 1; /* Print a warning. */
+      else /* Try to parse this option - ignore unchangeable ones. */
+        parse_rereadable_options (&pargs, 1);
+    }
+  fclose (fp);
+  set_debug ();
+}
+
+
+
+
+/* Create a name for the socket.  With USE_STANDARD_SOCKET given as
+   true using STANDARD_NAME in the home directory or if given has
+   false from the mkdir type name TEMPLATE.  In the latter case a
+   unique name in a unique new directory will be created.  In both
+   cases check for valid characters as well as against a maximum
+   allowed length for a unix domain socket is done.  The function
+   terminates the process in case of an error.  Retunrs: Pointer to an
+   allcoated string with the absolute name of the socket used.  */
+static char *
+create_socket_name (int use_standard_socket,
+		    char *standard_name, char *template)
+{
+  char *name, *p;
+
+  if (use_standard_socket)
+    name = make_filename (opt.homedir, standard_name, NULL);
+  else
+    {
+      name = xstrdup (template);
+      p = strrchr (name, '/');
+      if (!p)
+	BUG ();
+      *p = 0;
+      if (!mkdtemp (name))
+	{
+	  log_error (_("can't create directory `%s': %s\n"),
+		     name, strerror (errno));
+	  agent_exit (2);
+	}
+      *p = '/';
+    }
+
+  if (strchr (name, PATHSEP_C))
+    {
+      log_error (("`%s' are not allowed in the socket name\n"), PATHSEP_S);
+      agent_exit (2);
+    }
+  if (strlen (name) + 1 >= DIMof (struct sockaddr_un, sun_path) )
+    {
+      log_error (_("name of socket too long\n"));
+      agent_exit (2);
+    }
+  return name;
+}
+
+
+
+/* Create a Unix domain socket with NAME.  IS_STANDARD_NAME indicates
+   whether a non-random socket is used.  Returns the filedescriptor or
+   terminates the process in case of an error. */
+static int
+create_server_socket (int is_standard_name, const char *name)
+{
+  struct sockaddr_un *serv_addr;
+  socklen_t len;
+  int fd;
+  int rc;
+
+#ifdef HAVE_W32_SYSTEM
+  fd = _w32_sock_new (AF_UNIX, SOCK_STREAM, 0);
+#else
+  fd = socket (AF_UNIX, SOCK_STREAM, 0);
+#endif
+  if (fd == -1)
+    {
+      log_error (_("can't create socket: %s\n"), strerror (errno));
+      agent_exit (2);
+    }
+
+  serv_addr = xmalloc (sizeof (*serv_addr)); 
+  memset (serv_addr, 0, sizeof *serv_addr);
+  serv_addr->sun_family = AF_UNIX;
+  assert (strlen (name) + 1 < sizeof (serv_addr->sun_path));
+  strcpy (serv_addr->sun_path, name);
+  len = (offsetof (struct sockaddr_un, sun_path)
+	 + strlen (serv_addr->sun_path) + 1);
+
+#ifdef HAVE_W32_SYSTEM
+  rc = _w32_sock_bind (fd, (struct sockaddr*) serv_addr, len);
+  if (is_standard_name && rc == -1 )
+    {
+      remove (name);
+      rc = bind (fd, (struct sockaddr*) serv_addr, len);
+    }
+#else
+  rc = bind (fd, (struct sockaddr*) serv_addr, len);
+  if (is_standard_name && rc == -1 && errno == EADDRINUSE)
+    {
+      remove (name);
+      rc = bind (fd, (struct sockaddr*) serv_addr, len);
+    }
+#endif
+  if (rc == -1)
+    {
+      log_error (_("error binding socket to `%s': %s\n"),
+		 serv_addr->sun_path, strerror (errno));
+      close (fd);
+      agent_exit (2);
+    }
+
+  if (listen (fd, 5 ) == -1)
+    {
+      log_error (_("listen() failed: %s\n"), strerror (errno));
+      close (fd);
+      agent_exit (2);
+    }
+          
+  if (opt.verbose)
+    log_info (_("listening on socket `%s'\n"), serv_addr->sun_path);
+
+  return fd;
+}
+
+
+/* Check that the directory for storing the private keys exists and
+   create it if not.  This function won't fail as it is only a
+   convenience function and not strictly necessary.  */
+static void
+create_private_keys_directory (const char *home)
+{
+  char *fname;
+  struct stat statbuf;
+
+  fname = make_filename (home, GNUPG_PRIVATE_KEYS_DIR, NULL);
+  if (stat (fname, &statbuf) && errno == ENOENT)
+    {
+#ifdef HAVE_W32_SYSTEM  /*FIXME: Setup proper permissions.  */
+      if (!CreateDirectory (fname, NULL))
+        log_error (_("can't create directory `%s': %s\n"),
+                   fname, w32_strerror (-1) );
+#else
+      if (mkdir (fname, S_IRUSR|S_IWUSR|S_IXUSR ))
+        log_error (_("can't create directory `%s': %s\n"),
+                   fname, strerror (errno) );
+#endif
+      else if (!opt.quiet)
+        log_info (_("directory `%s' created\n"), fname);
+    }
+  xfree (fname);
+}
+
+/* Create the directory only if the supplied directory name is the
+   same as the default one.  This way we avoid to create arbitrary
+   directories when a non-default home directory is used.  To cope
+   with HOME, we compare only the suffix if we see that the default
+   homedir does start with a tilde.  We don't stop here in case of
+   problems because other functions will throw an error anyway.*/
+static void
+create_directories (void)
+{
+  struct stat statbuf;
+  const char *defhome = GNUPG_DEFAULT_HOMEDIR;
+  char *home;
+
+  home = make_filename (opt.homedir, NULL);
+  if ( stat (home, &statbuf) )
+    {
+      if (errno == ENOENT)
+        {
+          if ( (*defhome == '~'
+                && (strlen (home) >= strlen (defhome+1)
+                    && !strcmp (home + strlen(home)
+                                - strlen (defhome+1), defhome+1)))
+               || (*defhome != '~' && !strcmp (home, defhome) )
+               )
+            {
+#ifdef HAVE_W32_SYSTEM
+              if (!CreateDirectory (home, NULL))
+                log_error (_("can't create directory `%s': %s\n"),
+                           home, w32_strerror (-1) );
+#else
+              if (mkdir (home, S_IRUSR|S_IWUSR|S_IXUSR ))
+                log_error (_("can't create directory `%s': %s\n"),
+                           home, strerror (errno) );
+#endif
+              else 
+                {
+                  if (!opt.quiet)
+                    log_info (_("directory `%s' created\n"), home);
+                  create_private_keys_directory (home);
+                }
+            }
+        }
+      else
+        log_error (_("stat() failed for `%s': %s\n"), home, strerror (errno));
+    }
+  else if ( !S_ISDIR(statbuf.st_mode))
+    {
+      log_error (_("can't use `%s' as home directory\n"), home);
+    }
+  else /* exists and is a directory. */
+    {
+      create_private_keys_directory (home);
+    }
+  xfree (home);
+}
+
+
+
+/* This is the worker for the ticker.  It is called every few seconds
+   and may only do fast operations. */
+static void
+handle_tick (void)
+{
+  /* Check whether the scdaemon has died and cleanup in this case. */
+  agent_scd_check_aliveness ();
+
+  /* If we are running as a child of another process, check whether
+     the parent is still alive and shutdown if not. */
+#ifndef HAVE_W32_SYSTEM
+  if (parent_pid != (pid_t)(-1))
+    {
+      if (kill (parent_pid, 0))
+        {
+          shutdown_pending = 2;
+          log_info ("parent process died - shutting down\n");
+          log_info ("%s %s stopped\n", strusage(11), strusage(13) );
+          cleanup ();
+          agent_exit (0);
+        }
+    }
+#endif /*HAVE_W32_SYSTEM*/
+}
+
+
+static void
+handle_signal (int signo)
+{
+  switch (signo)
+    {
+#ifndef HAVE_W32_SYSTEM
+    case SIGHUP:
+      log_info ("SIGHUP received - "
+                "re-reading configuration and flushing cache\n");
+      agent_flush_cache ();
+      reread_configuration ();
+      agent_reload_trustlist ();
+      break;
+      
+    case SIGUSR1:
+      log_info ("SIGUSR1 received - printing internal information:\n");
+      pth_ctrl (PTH_CTRL_DUMPSTATE, log_get_stream ());
+      agent_query_dump_state ();
+      agent_scd_dump_state ();
+      break;
+      
+    case SIGUSR2:
+      if (opt.verbose)
+        log_info ("SIGUSR2 received - checking smartcard status\n");
+      break;
+
+    case SIGTERM:
+      if (!shutdown_pending)
+        log_info ("SIGTERM received - shutting down ...\n");
+      else
+        log_info ("SIGTERM received - still %ld running threads\n",
+                  pth_ctrl( PTH_CTRL_GETTHREADS ));
+      shutdown_pending++;
+      if (shutdown_pending > 2)
+        {
+          log_info ("shutdown forced\n");
+          log_info ("%s %s stopped\n", strusage(11), strusage(13) );
+          cleanup ();
+          agent_exit (0);
+	}
+      break;
+        
+    case SIGINT:
+      log_info ("SIGINT received - immediate shutdown\n");
+      log_info( "%s %s stopped\n", strusage(11), strusage(13));
+      cleanup ();
+      agent_exit (0);
+      break;
+#endif
+    default:
+      log_info ("signal %d received - no action defined\n", signo);
+    }
+}
+
+
+/* This is the standard connection thread's main function.  */
+static void *
+start_connection_thread (void *arg)
+{
+  int fd = (int)arg;
+
+  if (opt.verbose)
+    log_info (_("handler 0x%lx for fd %d started\n"), 
+              (long)pth_self (), fd);
+
+  /* FIXME: Move this housekeeping into a ticker function.  Calling it
+     for each connection should work but won't work anymore if our
+     clients start to keep connections. */
+  agent_trustlist_housekeeping ();
+
+  start_command_handler (-1, fd);
+  if (opt.verbose)
+    log_info (_("handler 0x%lx for fd %d terminated\n"), 
+              (long)pth_self (), fd);
+  
+  return NULL;
+}
+
+
+/* This is the ssh connection thread's main function.  */
+static void *
+start_connection_thread_ssh (void *arg)
+{
+  int fd = (int)arg;
+
+  if (opt.verbose)
+    log_info (_("ssh handler 0x%lx for fd %d started\n"),
+              (long)pth_self (), fd);
+
+  agent_trustlist_housekeeping ();
+
+  start_command_handler_ssh (fd);
+  if (opt.verbose)
+    log_info (_("ssh handler 0x%lx for fd %d terminated\n"),
+              (long)pth_self (), fd);
+  
+  return NULL;
+}
+
+
+/* Connection handler loop.  Wait for coecntion requests and spawn a
+   thread after accepting a connection.  */
+static void
+handle_connections (int listen_fd, int listen_fd_ssh)
+{
+  pth_attr_t tattr;
+  pth_event_t ev, time_ev;
+  sigset_t sigs;
+  int signo;
+  struct sockaddr_un paddr;
+  socklen_t plen;
+  fd_set fdset, read_fdset;
+  int ret;
+  int fd;
+
+  tattr = pth_attr_new();
+  pth_attr_set (tattr, PTH_ATTR_JOINABLE, 0);
+  pth_attr_set (tattr, PTH_ATTR_STACK_SIZE, 256*1024);
+
+#ifndef HAVE_W32_SYSTEM /* fixme */
+  /* Make sure that the signals we are going to handle are not blocked
+     and create an event object for them. */
+  sigemptyset (&sigs );
+  sigaddset (&sigs, SIGHUP);
+  sigaddset (&sigs, SIGUSR1);
+  sigaddset (&sigs, SIGUSR2);
+  sigaddset (&sigs, SIGINT);
+  sigaddset (&sigs, SIGTERM);
+  pth_sigmask (SIG_UNBLOCK, &sigs, NULL);
+  ev = pth_event (PTH_EVENT_SIGS, &sigs, &signo);
+#else
+  ev = NULL;
+#endif
+  time_ev = NULL;
+
+  FD_ZERO (&fdset);
+  FD_SET (listen_fd, &fdset);
+  if (listen_fd_ssh != -1)
+    FD_SET (listen_fd_ssh, &fdset);
+
+  for (;;)
+    {
+      sigset_t oldsigs;
+
+      if (shutdown_pending)
+        {
+          if (pth_ctrl (PTH_CTRL_GETTHREADS) == 1)
+            break; /* ready */
+
+          /* Do not accept anymore connections and wait for existing
+             connections to terminate */
+          signo = 0;
+          pth_wait (ev);
+          if (pth_event_occurred (ev) && signo)
+            handle_signal (signo);
+          continue;
+	}
+
+      /* Create a timeout event if needed. */
+      if (!time_ev)
+        time_ev = pth_event (PTH_EVENT_TIME, pth_timeout (2, 0));
+
+      /* POSIX says that fd_set should be implemented as a structure,
+         thus a simple assignment is fine to copy the entire set.  */
+      read_fdset = fdset;
+
+      if (time_ev)
+        pth_event_concat (ev, time_ev, NULL);
+      ret = pth_select_ev (FD_SETSIZE, &read_fdset, NULL, NULL, NULL, ev);
+      if (time_ev)
+        pth_event_isolate (time_ev);
+
+      if (ret == -1)
+	{
+          if (pth_event_occurred (ev)
+              || (time_ev && pth_event_occurred (time_ev)))
+            {
+              if (pth_event_occurred (ev))
+                handle_signal (signo);
+              if (time_ev && pth_event_occurred (time_ev))
+                {
+                  pth_event_free (time_ev, PTH_FREE_ALL);
+                  time_ev = NULL;
+                  handle_tick ();
+                }
+              continue;
+            }
+          log_error (_("pth_select failed: %s - waiting 1s\n"),
+                     strerror (errno));
+          pth_sleep (1);
+	  continue;
+	}
+
+      if (pth_event_occurred (ev))
+        {
+          handle_signal (signo);
+        }
+
+      if (time_ev && pth_event_occurred (time_ev))
+        {
+          pth_event_free (time_ev, PTH_FREE_ALL);
+          time_ev = NULL;
+          handle_tick ();
+        }
+
+      
+      /* We now might create new threads and because we don't want any
+         signals - we are handling here - to be delivered to a new
+         thread. Thus we need to block those signals. */
+      pth_sigmask (SIG_BLOCK, &sigs, &oldsigs);
+
+      if (FD_ISSET (listen_fd, &read_fdset))
+	{
+          plen = sizeof paddr;
+	  fd = pth_accept (listen_fd, (struct sockaddr *)&paddr, &plen);
+	  if (fd == -1)
+	    {
+	      log_error ("accept failed: %s\n", strerror (errno));
+	    }
+          else 
+            {
+              char threadname[50];
+              snprintf (threadname, sizeof threadname-1,
+                        "conn fd=%d (gpg)", fd);
+              threadname[sizeof threadname -1] = 0;
+              pth_attr_set (tattr, PTH_ATTR_NAME, threadname);
+              if (!pth_spawn (tattr, start_connection_thread, (void*)fd))
+                {
+                  log_error ("error spawning connection handler: %s\n",
+                             strerror (errno) );
+                  close (fd);
+                }
+            }
+          fd = -1;
+	}
+
+      if (listen_fd_ssh != -1 && FD_ISSET (listen_fd_ssh, &read_fdset))
+	{
+          plen = sizeof paddr;
+	  fd = pth_accept (listen_fd_ssh, (struct sockaddr *)&paddr, &plen);
+	  if (fd == -1)
+	    {
+	      log_error ("accept failed for ssh: %s\n", strerror (errno));
+	    }
+          else
+            {
+              char threadname[50];
+              snprintf (threadname, sizeof threadname-1,
+                        "conn fd=%d (ssh)", fd);
+              threadname[sizeof threadname -1] = 0;
+              pth_attr_set (tattr, PTH_ATTR_NAME, threadname);
+
+              if (!pth_spawn (tattr, start_connection_thread_ssh, (void*)fd))
+                {
+                  log_error ("error spawning ssh connection handler: %s\n",
+                             strerror (errno) );
+                  close (fd);
+                }
+            }
+          fd = -1;
+	}
+
+      /* Restore the signal mask. */
+      pth_sigmask (SIG_SETMASK, &oldsigs, NULL);
+
+    }
+
+  pth_event_free (ev, PTH_FREE_ALL);
+  if (time_ev)
+    pth_event_free (time_ev, PTH_FREE_ALL);
+  cleanup ();
+  log_info (_("%s %s stopped\n"), strusage(11), strusage(13));
+}
+
+
+/* Figure out whether an agent is available and running. Prints an
+   error if not.  Usually started with MODE 0. */
+static int
+check_for_running_agent (int mode)
+{
+  int rc;
+  char *infostr, *p;
+  assuan_context_t ctx;
+  int prot, pid;
+
+  if (!mode)
+    {
+      infostr = getenv ("GPG_AGENT_INFO");
+      if (!infostr || !*infostr)
+        {
+          if (!check_for_running_agent (1))
+            return 0; /* Okay, its running on the standard socket. */
+          log_error (_("no gpg-agent running in this session\n"));
+          return -1;
+        }
+
+      infostr = xstrdup (infostr);
+      if ( !(p = strchr (infostr, PATHSEP_C)) || p == infostr)
+        {
+          xfree (infostr);
+          if (!check_for_running_agent (1))
+            return 0; /* Okay, its running on the standard socket. */
+          log_error (_("malformed GPG_AGENT_INFO environment variable\n"));
+          return -1;
+        }
+
+      *p++ = 0;
+      pid = atoi (p);
+      while (*p && *p != PATHSEP_C)
+        p++;
+      prot = *p? atoi (p+1) : 0;
+      if (prot != 1)
+        {
+          xfree (infostr);
+          log_error (_("gpg-agent protocol version %d is not supported\n"),
+                     prot);
+          if (!check_for_running_agent (1))
+            return 0; /* Okay, its running on the standard socket. */
+          return -1;
+        }
+    }
+  else /* MODE != 0 */
+    {
+      infostr = make_filename (opt.homedir, "S.gpg-agent", NULL);
+      pid = (pid_t)(-1);
+    }
+
+
+  rc = assuan_socket_connect (&ctx, infostr, pid);
+  xfree (infostr);
+  if (rc)
+    {
+      if (!mode && !check_for_running_agent (1))
+        return 0; /* Okay, its running on the standard socket. */
+
+      if (!mode)
+        log_error ("can't connect to the agent: %s\n", assuan_strerror (rc));
+      return -1;
+    }
+
+  if (!opt.quiet)
+    log_info ("gpg-agent running and available\n");
+
+  assuan_disconnect (ctx);
+  return 0;
+}