common: Split up socket setup from flatpak-run into multiple files

flatpak-run is large enough to be getting unwieldy, so separate it out
into various smaller modules.

A side benefit of these is that they'll be easier to reuse in other
projects, like Steam's pressure-vessel tool.

Signed-off-by: Simon McVittie <smcv@collabora.com>

1 files changed, 127 insertions, 0 deletions

diff --git a/common/flatpak-run-cups.c b/common/flatpak-run-cups.c
new file mode 100644
index 00000000..c355e0f8
--- /dev/null
+++ b/common/flatpak-run-cups.c
@@ -0,0 +1,127 @@
+/* vi:set et sw=2 sts=2 cin cino=t0,f0,(0,{s,>2s,n-s,^-s,e-s:
+ * Copyright © 2014-2019 Red Hat, Inc
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors:
+ *       Alexander Larsson <alexl@redhat.com>
+ */
+
+#include "config.h"
+#include "flatpak-run-cups-private.h"
+
+#include "flatpak-utils-private.h"
+
+static gboolean
+flatpak_run_cups_check_server_is_socket (const char *server)
+{
+  if (g_str_has_prefix (server, "/") && strstr (server, ":") == NULL)
+    return TRUE;
+
+  return FALSE;
+}
+
+/* Try to find a default server from a cups confguration file */
+static char *
+flatpak_run_get_cups_server_name_config (const char *path)
+{
+  g_autoptr(GFile) file = g_file_new_for_path (path);
+  g_autoptr(GError) my_error = NULL;
+  g_autoptr(GFileInputStream) input_stream = NULL;
+  g_autoptr(GDataInputStream) data_stream = NULL;
+  size_t len;
+
+  input_stream = g_file_read (file, NULL, &my_error);
+  if (my_error)
+    {
+      g_info ("CUPS configuration file '%s': %s", path, my_error->message);
+      return NULL;
+    }
+
+  data_stream = g_data_input_stream_new (G_INPUT_STREAM (input_stream));
+
+  while (TRUE)
+    {
+      g_autofree char *line = g_data_input_stream_read_line (data_stream, &len, NULL, NULL);
+      if (line == NULL)
+        break;
+
+      g_strchug (line);
+
+      if ((*line  == '\0') || (*line == '#'))
+        continue;
+
+      g_auto(GStrv) tokens = g_strsplit (line, " ", 2);
+
+      if ((tokens[0] != NULL) && (tokens[1] != NULL))
+        {
+          if (strcmp ("ServerName", tokens[0]) == 0)
+            {
+              g_strchug (tokens[1]);
+
+              if (flatpak_run_cups_check_server_is_socket (tokens[1]))
+                return g_strdup (tokens[1]);
+            }
+        }
+    }
+
+    return NULL;
+}
+
+static char *
+flatpak_run_get_cups_server_name (void)
+{
+  g_autofree char * cups_server = NULL;
+  g_autofree char * cups_config_path = NULL;
+
+  /* TODO
+   * we don't currently support cups servers located on the network, if such
+   * server is detected, we simply ignore it and in the worst case we fallback
+   * to the default socket
+   */
+  cups_server = g_strdup (g_getenv ("CUPS_SERVER"));
+  if (cups_server && flatpak_run_cups_check_server_is_socket (cups_server))
+    return g_steal_pointer (&cups_server);
+  g_clear_pointer (&cups_server, g_free);
+
+  cups_config_path = g_build_filename (g_get_home_dir (), ".cups/client.conf", NULL);
+  cups_server = flatpak_run_get_cups_server_name_config (cups_config_path);
+  if (cups_server && flatpak_run_cups_check_server_is_socket (cups_server))
+    return g_steal_pointer (&cups_server);
+  g_clear_pointer (&cups_server, g_free);
+
+  cups_server = flatpak_run_get_cups_server_name_config ("/etc/cups/client.conf");
+  if (cups_server && flatpak_run_cups_check_server_is_socket (cups_server))
+    return g_steal_pointer (&cups_server);
+
+  // Fallback to default socket
+  return g_strdup ("/var/run/cups/cups.sock");
+}
+
+void
+flatpak_run_add_cups_args (FlatpakBwrap *bwrap)
+{
+  g_autofree char * sandbox_server_name = g_strdup ("/var/run/cups/cups.sock");
+  g_autofree char * cups_server_name = flatpak_run_get_cups_server_name ();
+
+  if (!g_file_test (cups_server_name, G_FILE_TEST_EXISTS))
+    {
+      g_info ("Could not find CUPS server");
+      return;
+    }
+
+  flatpak_bwrap_add_args (bwrap,
+                          "--ro-bind", cups_server_name, sandbox_server_name,
+                          NULL);
+}