old WiP: inetd-style listeningwip-inetd

2 files changed, 125 insertions, 16 deletions

diff --git a/dbus/dbus-server-unix.c b/dbus/dbus-server-unix.c
index 70ad9654..20e2dd8d 100644
--- a/dbus/dbus-server-unix.c
+++ b/dbus/dbus-server-unix.c
@@ -179,7 +179,33 @@ _dbus_server_listen_platform_specific (DBusAddressEntry *entry,
       dbus_free (fds);
 
       return DBUS_SERVER_LISTEN_OK;
-	}
+    }
+  else if (strcmp (method, "inetd") == 0)
+    {
+      int fd;
+      DBusString address;
+
+      fd = _dbus_listen_inetd (error);
+
+      if (fd < 0)
+        {
+          _DBUS_ASSERT_ERROR_IS_SET (error);
+          return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
+        }
+
+      _dbus_string_init_const (&address, "inetd:");
+
+      *server_p = _dbus_server_new_for_socket (&fd, 1, &address, NULL);
+
+      if (*server_p == NULL)
+        {
+          _dbus_close_socket (fd, NULL);
+          dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
+          return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
+        }
+
+      return DBUS_SERVER_LISTEN_OK;
+    }
 #ifdef DBUS_ENABLE_LAUNCHD
   else if (strcmp (method, "launchd") == 0)
     {
diff --git a/dbus/dbus-sysdeps-unix.c b/dbus/dbus-sysdeps-unix.c
index e9ea2535..58cd50e8 100644
--- a/dbus/dbus-sysdeps-unix.c
+++ b/dbus/dbus-sysdeps-unix.c
@@ -1028,6 +1028,102 @@ _dbus_listen_unix_socket (const char     *path,
   return listen_fd;
 }
 
+static dbus_bool_t
+check_socket_is_listening_stream (int        fd,
+                                  DBusError *error)
+{
+  /* We use systemd utility functions here: they're meant to be portable
+   * to non-Linux Unixes */
+  r = sd_is_socket (fd, AF_UNSPEC, SOCK_STREAM, 1);
+
+  if (r < 0)
+    {
+      dbus_set_error (error, _dbus_error_from_errno (-r),
+                      "Failed to verify passed socket type: %s",
+                      _dbus_strerror (-r));
+      return FALSE;
+    }
+
+  if (!r)
+    {
+      dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS,
+                      "Passed socket has wrong type.");
+      return FALSE;
+    }
+
+  return TRUE;
+}
+
+/**
+ * Acquires the socket that is our stdin and stdout. Reopens stdin and stdout
+ * from/to /dev/null, sets the socket to be nonblocking and close on exec,
+ * and returns the socket's new fd.
+ *
+ * @returns a socket fd, or -1 on error
+ */
+int
+_dbus_listen_inetd (DBusError *error)
+{
+  int fd = -1, nullfd = -1;
+
+  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
+
+  if (!check_socket_is_listening_stream (STDIN_FILENO, error))
+    return -1;
+
+  if (!check_socket_is_listening_stream (STDOUT_FILENO, error))
+    return -1;
+
+  nullfd = open ("/dev/null", O_RDWR);
+
+  if (nullfd == -1)
+    {
+      dbus_set_error (error, DBUS_ERROR_FAILED, "Failed to open /dev/null");
+      goto fail;
+    }
+
+  fd = _dbus_dup (STDIN_FILENO, error);
+
+  if (fd < 0)
+    goto fail;
+
+  if (dup2 (fd, STDIN_FILENO))
+    {
+      dbus_set_error (error, DBUS_ERROR_FAILED,
+                      "Failed to dup /dev/null to replace stdin");
+      goto fail;
+    }
+
+  if (dup2 (fd, STDOUT_FILENO))
+    {
+      dbus_set_error (error, DBUS_ERROR_FAILED,
+                      "Failed to dup /dev/null to replace stdout");
+      goto fail;
+    }
+
+  _dbus_close (nullfd, NULL);
+  nullfd = -1;
+
+  if (!_dbus_set_local_creds (fd, TRUE))
+    {
+      dbus_set_error (error, _dbus_error_from_errno (errno),
+                      "Failed to enable LOCAL_CREDS on inetd socket: %s",
+                      _dbus_strerror (errno));
+      goto fail;
+    }
+
+  return fd;
+
+fail:
+  if (fd >= 0)
+    _dbus_close (fd, NULL);
+
+  if (nullfd >= 0)
+    _dbus_close (nullfd, NULL);
+
+  return -1;
+}
+
 /**
  * Acquires one or more sockets passed in from systemd. The sockets
  * are set to be nonblocking.
@@ -1066,21 +1162,8 @@ _dbus_listen_systemd_sockets (int       **fds,
 
   for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + n; fd ++)
     {
-      r = sd_is_socket (fd, AF_UNSPEC, SOCK_STREAM, 1);
-      if (r < 0)
-        {
-          dbus_set_error (error, _dbus_error_from_errno (-r),
-                          "Failed to verify systemd socket type: %s",
-                          _dbus_strerror (-r));
-          return -1;
-        }
-
-      if (!r)
-        {
-          dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS,
-                          "Passed socket has wrong type.");
-          return -1;
-        }
+      if (!check_socket_is_listening_stream (fd, error))
+        return -1;
     }
 
   /* OK, the file descriptors are all good, so let's take posession of