Address persistence and a system-wide server (Issue #128, Issue #148)

- _papplMainloopRunServer now chooses a default spool directory and state file
  based on the base name of the printer application, and those files go in
  persistent locations.
- _papplMainloopConnect now tries connecting to a root server if the per-user
  server cannot be found, before starting a per-user server.
- _papplMainloopGetServerPath now takes a UID argument.

CHANGES.md

@@ -6,6 +6,10 @@ Changes in v1.1b1
 
 - Added `PAPPL_SOPTIONS_NO_TLS` option to disable TLS support.
 - Added Wi-Fi callbacks to support configuration over IPP-USB (Issue #45)
+- `papplMainLoop` now uses a persistent location for state and spool files by
+  default (Issue #128)
+- `papplMainLoop` now supports clients talking to a system-wide server running
+  as root (Issue #148)
 
 
 Changes in v1.0.3

config.h.in

@@ -13,6 +13,14 @@
 #define PAPPL_VERSION_MINOR 0
 
 
+// Location of PAPPL state and spool data (when run as root)
+#define PAPPL_LOCALSTATEDIR	"/usr/local/var"
+
+
+// Location of PAPPL domain socket (when run as root)
+#define PAPPL_RUNSTATEDIR	"/usr/local/var/run"
+
+
 // Location of CUPS config files
 #define CUPS_SERVERROOT		"/etc/cups"
 

configure

@@ -5070,6 +5070,65 @@ then :
 fi
 
 
+if test "$localstatedir" = "\${prefix}/var"
+then :
+
+    if test "$host_os_name" = darwin
+then :
+
+
+printf "%s\n" "#define PAPPL_LOCALSTATEDIR \"/Library\"" >>confdefs.h
+
+
+else $as_nop
+
+
+printf "%s\n" "#define PAPPL_LOCALSTATEDIR \"$prefix/var\"" >>confdefs.h
+
+
+fi
+
+else $as_nop
+
+
+printf "%s\n" "#define PAPPL_LOCALSTATEDIR \"$localstatedir\"" >>confdefs.h
+
+
+fi
+
+if test "$runstatedir" = "\${localstatedir}/run"
+then :
+
+    if test "$host_os_name" = darwin
+then :
+
+
+printf "%s\n" "#define PAPPL_RUNSTATEDIR \"/private/var/run\"" >>confdefs.h
+
+
+elif test "$localstatedir" = "\${prefix}/var"
+then :
+
+
+printf "%s\n" "#define PAPPL_RUNSTATEDIR \"$prefix/var/run\"" >>confdefs.h
+
+
+else $as_nop
+
+
+printf "%s\n" "#define PAPPL_RUNSTATEDIR \"$localstatedir/run\"" >>confdefs.h
+
+
+fi
+
+else $as_nop
+
+
+printf "%s\n" "#define PAPPL_RUNSTATEDIR \"$runstatedir\"" >>confdefs.h
+
+
+fi
+
 
 ac_config_files="$ac_config_files Makedefs pappl/pappl.pc"
 

configure.ac

@@ -476,6 +476,29 @@ AC_ARG_WITH([ldflags], AS_HELP_STRING([--with-ldflags=...], [Specify additional
     LDFLAGS="$withval $LDFLAGS"
 ])
 
+dnl State and run directories for root servers...
+AS_IF([test "$localstatedir" = "\${prefix}/var"], [
+    AS_IF([test "$host_os_name" = darwin], [
+        AC_DEFINE_UNQUOTED([PAPPL_LOCALSTATEDIR], ["/Library"], [Location of PAPPL state and spool data (when run as root)])
+    ], [
+        AC_DEFINE_UNQUOTED([PAPPL_LOCALSTATEDIR], ["$prefix/var"], [Location of PAPPL state and spool data (when run as root)])
+    ])
+], [
+    AC_DEFINE_UNQUOTED([PAPPL_LOCALSTATEDIR], ["$localstatedir"], [Location of PAPPL state and spool data (when run as root)])
+])
+
+AS_IF([test "$runstatedir" = "\${localstatedir}/run"], [
+    AS_IF([test "$host_os_name" = darwin], [
+        AC_DEFINE_UNQUOTED([PAPPL_RUNSTATEDIR], ["/private/var/run"], [Location of PAPPL domain socket (when run as root)])
+    ], [test "$localstatedir" = "\${prefix}/var"], [
+        AC_DEFINE_UNQUOTED([PAPPL_RUNSTATEDIR], ["$prefix/var/run"], [Location of PAPPL domain socket (when run as root)])
+    ], [
+        AC_DEFINE_UNQUOTED([PAPPL_RUNSTATEDIR], ["$localstatedir/run"], [Location of PAPPL domain socket (when run as root)])
+    ])
+], [
+    AC_DEFINE_UNQUOTED([PAPPL_RUNSTATEDIR], ["$runstatedir"], [Location of PAPPL domain socket (when run as root)])
+])
+
 
 dnl Generate the Makefile and pkg-config file...
 AC_CONFIG_FILES([Makedefs pappl/pappl.pc])

pappl/mainloop-private.h

@@ -59,7 +59,7 @@ extern void	_papplMainloopAddPrinterURI(ipp_t *request, const char *printer_name
 extern http_t	*_papplMainloopConnect(const char *base_name, bool auto_start) _PAPPL_PRIVATE;
 extern http_t	*_papplMainloopConnectURI(const char *base_name, const char *printer_uri, char  *resource, size_t rsize) _PAPPL_PRIVATE;
 extern char	*_papplMainloopGetDefaultPrinter(http_t *http, char *buffer, size_t bufsize) _PAPPL_PRIVATE;
-extern char	*_papplMainloopGetServerPath(const char *base_name, char *buffer, size_t bufsize) _PAPPL_PRIVATE;
+extern char	*_papplMainloopGetServerPath(const char *base_name, uid_t uid, char *buffer, size_t bufsize) _PAPPL_PRIVATE;
 
 
 //

pappl/mainloop-subcommands.c

@@ -519,15 +519,35 @@ _papplMainloopRunServer(
   pappl_system_t	*system;	// System object
   char			sockname[1024],	// Socket filename
 			statename[1024];// State filename
+  const char		*home = getenv("HOME");
+					// Home directory
+  const char		*snap_common = getenv("SNAP_COMMON");
+					// Common data directory for snaps
+  const char		*tmpdir = getenv("TMPDIR");
+					// Temporary directory
+  const char		*xdg_config_home = getenv("XDG_CONFIG_HOME");
+					// Freedesktop per-user config directory
+
 
+  // Make sure we know the temporary directory...
+#ifdef __APPLE__
+  if (!tmpdir)
+    tmpdir = "/private/tmp";
+#else
+  if (!tmpdir)
+    tmpdir = "/tmp";
+#endif // __APPLE__
 
   // Create the system object...
   if (system_cb)
   {
+    // Developer-supplied system object...
     system = (system_cb)(num_options, options, data);
   }
   else
   {
+    // Default system object...
+    char	spoolname[1024];	// Default spool directory
     const char	*directory = cupsGetOption("spool-directory", num_options, options),
 					// Spool directory
 		*logfile = cupsGetOption("log-file", num_options, options),
@@ -567,6 +587,39 @@ _papplMainloopRunServer(
       }
     }
 
+    // Make sure we have a spool directory...
+    if (!directory)
+    {
+      if (snap_common)
+      {
+	// Running inside a snap (https://snapcraft.io), so use the snap's common
+	// data directory...
+	snprintf(spoolname, sizeof(spoolname), "%s/%s.d", snap_common, base_name);
+      }
+      else if (!getuid())
+      {
+	// Running as root, so put the state file in the local state directory
+#ifdef __APPLE__
+	snprintf(spoolname, sizeof(spoolname), PAPPL_LOCALSTATEDIR "/Caches/%s", base_name);
+
+#else
+	if (access(PAPPL_LOCALSTATEDIR "/spool", X_OK) && errno == ENOENT)
+	  mkdir(PAPPL_LOCALSTATEDIR "/spool", 0777);
+					// Make sure base directory exists
+
+	snprintf(spoolname, sizeof(spoolname), PAPPL_LOCALSTATEDIR "/spool/%s", base_name);
+#endif // __APPLE__
+      }
+      else
+      {
+	// As a last resort, put the state in the temporary directory (where it
+	// will be lost on the nest reboot/logout...
+	snprintf(spoolname, sizeof(spoolname), "%s/%s%d.d", tmpdir, base_name, (int)getuid());
+      }
+
+      directory = spoolname;
+    }
+
     // Create the system object...
     system = papplSystemCreate(PAPPL_SOPTIONS_MULTI_QUEUE | PAPPL_SOPTIONS_WEB_INTERFACE, base_name, port, "_print,_universal", directory, logfile, loglevel, cupsGetOption("auth-service", num_options, options), false);
 
@@ -605,25 +658,60 @@ _papplMainloopRunServer(
     papplSystemSetPrinterDrivers(system, num_drivers, drivers, autoadd_cb, /* create_cb */NULL, driver_cb, data);
 
   // Listen for connections...
-  papplSystemAddListeners(system, _papplMainloopGetServerPath(base_name, sockname, sizeof(sockname)));
+  papplSystemAddListeners(system, _papplMainloopGetServerPath(base_name, getuid(), sockname, sizeof(sockname)));
 
   // Finish initialization...
   if (!system->save_cb)
   {
-    const char	*tmpdir = getenv("TMPDIR");
-					// Temporary directory
-
     // Register a callback for saving state information, then load any
     // previous state...
+    if (snap_common)
+    {
+      // Running inside a snap (https://snapcraft.io), so use the snap's common
+      // data directory...
+      snprintf(statename, sizeof(statename), "%s/%s.state", snap_common, base_name);
+    }
+    else if (!getuid())
+    {
+      // Running as root, so put the state file in the local state directory
 #ifdef __APPLE__
-    if (!tmpdir)
-      tmpdir = "/private/tmp";
+      snprintf(statename, sizeof(statename), PAPPL_LOCALSTATEDIR "/Application Support/%s.state", base_name);
+
 #else
-    if (!tmpdir)
-      tmpdir = "/tmp";
+      if (access(PAPPL_LOCALSTATEDIR "/lib", X_OK) && errno == ENOENT)
+        mkdir(PAPPL_LOCALSTATEDIR "/lib", 0777);
+					// Make sure base directory exists
+
+      snprintf(statename, sizeof(statename), PAPPL_LOCALSTATEDIR "/lib/%s.state", base_name);
 #endif // __APPLE__
+    }
+    else if (xdg_config_home)
+    {
+      // Use Freedesktop per-user config directory
+      snprintf(statename, sizeof(statename), "%s/%s.state", xdg_config_home, base_name);
+    }
+    else if (home)
+    {
+#ifdef __APPLE__
+      // Put the state in "~/Library/Application Support"
+      snprintf(statename, sizeof(statename), "%s/Library/Application Support/%s.state", home, base_name);
+
+#else
+      // Put the state under a ".config" directory in the home directory
+      snprintf(statename, sizeof(statename), "%s/.config", home);
+      if (access(statename, X_OK) && errno == ENOENT)
+        mkdir(statename, 0777);			// Make ~/.config as needed
+
+      snprintf(statename, sizeof(statename), "%s/.config/%s.state", home, base_name);
+#endif // __APPL__
+    }
+    else
+    {
+      // As a last resort, put the state in the temporary directory (where it
+      // will be lost on the nest reboot/logout...
+      snprintf(statename, sizeof(statename), "%s/%s%d.state", tmpdir, base_name, (int)getuid());
+    }
 
-    snprintf(statename, sizeof(statename), "%s/%s%d.state", tmpdir, base_name, (int)getuid());
     papplSystemLoadState(system, statename);
     papplSystemSetSaveCallback(system, (pappl_save_cb_t)papplSystemSaveState, (void *)statename);
   }

pappl/mainloop-support.c

@@ -317,7 +317,13 @@ _papplMainloopConnect(
 
 
   // See if the server is running...
-  http = httpConnect2(_papplMainloopGetServerPath(base_name, sockname, sizeof(sockname)), 0, NULL, AF_UNSPEC, HTTP_ENCRYPTION_IF_REQUESTED, 1, 30000, NULL);
+  http = httpConnect2(_papplMainloopGetServerPath(base_name, getuid(), sockname, sizeof(sockname)), 0, NULL, AF_UNSPEC, HTTP_ENCRYPTION_IF_REQUESTED, 1, 30000, NULL);
+
+  if (!http && getuid())
+  {
+    // Try root server...
+    http = httpConnect2(_papplMainloopGetServerPath(base_name, 0, sockname, sizeof(sockname)), 0, NULL, AF_UNSPEC, HTTP_ENCRYPTION_IF_REQUESTED, 1, 30000, NULL);
+  }
 
   if (!http && auto_start)
   {
@@ -346,6 +352,8 @@ _papplMainloopConnect(
     posix_spawnattr_destroy(&server_attrs);
 
     // Wait for it to start...
+    _papplMainloopGetServerPath(base_name, getuid(), sockname, sizeof(sockname));
+
     do
     {
       usleep(250000);
@@ -449,22 +457,33 @@ _papplMainloopGetDefaultPrinter(
 char *					// O - Socket filename
 _papplMainloopGetServerPath(
     const char *base_name,		// I - Base name
+    uid_t      uid,			// I - UID for server
     char       *buffer,			// I - Buffer for filename
     size_t     bufsize)			// I - Size of buffer
 {
-  const char	*tmpdir = getenv("TMPDIR");
+  if (uid)
+  {
+    // Per-user server...
+    const char	*tmpdir = getenv("TMPDIR");
 					// Temporary directory
 
 #ifdef __APPLE__
-  if (!tmpdir)
-    tmpdir = "/private/tmp";
+    if (!tmpdir)
+      tmpdir = "/private/tmp";
 #else
-  if (!tmpdir)
-    tmpdir = "/tmp";
+    if (!tmpdir)
+      tmpdir = "/tmp";
 #endif // __APPLE__
 
-  snprintf(buffer, bufsize, "%s/%s%d.sock", tmpdir, base_name, (int)getuid());
-  _PAPPL_DEBUG("Creating domain socket as '%s'.\n", buffer);
+    snprintf(buffer, bufsize, "%s/%s%d.sock", tmpdir, base_name, (int)uid);
+  }
+  else
+  {
+    // System server running as root
+    snprintf(buffer, bufsize, PAPPL_RUNSTATEDIR "/%s.sock", base_name);
+  }
+
+  _PAPPL_DEBUG("Using domain socket '%s'.\n", buffer);
 
   return (buffer);
 }

xcode/config.h

@@ -13,6 +13,14 @@
 #define PAPPL_VERSION_MINOR	1
 
 
+// Location of PAPPL state and spool data (when run as root)
+#define PAPPL_LOCALSTATEDIR	"/Library"
+
+
+// Location of PAPPL domain socket (when run as root)
+#define PAPPL_RUNSTATEDIR	"/private/var/run"
+
+
 // Location of CUPS config files
 #define CUPS_SERVERROOT		"/private/etc/cups"