Bug 97927

Comment on attachment 126778 [details] [review]
patch against the master branch, #1e43857

Review of attachment 126778 [details] [review]:
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::: configure.ac
@@ +144,4 @@
>  
>  # For best security, assume that all non-Windows platforms can do
>  # credentials-passing.
> +AS_IF([test "$dbus_win" = yes || test "$dbus_darwin" = yes],

If Darwin/OS X supports AF_UNIX credentials-passing (SCM_CREDENTIALS or getpeereid() or one of the various other ways we know about), then it should force <auth>EXTERNAL</auth> just like Linux does. That mechanism is by far the best one available to us.

If Darwin/OS X supports AF_UNIX credentials-passing but not by one of the code paths we know about, please contribute code to add a Darwin code path to dbus-sysdeps-unix instead of disabling this. That should be a separate commit.

If Darwin/OS X does not support AF_UNIX credentials passing at all, then not using <auth>EXTERNAL</auth> should be a separate commit, and the comment just above here also needs changing.

@@ +201,5 @@
>  AC_ARG_WITH(system-socket, AS_HELP_STRING([--with-system-socket=[filename]],[UNIX domain socket for systemwide daemon]))
>  AC_ARG_WITH(console-auth-dir, AS_HELP_STRING([--with-console-auth-dir=[dirname]],[directory to check for console ownerhip]))
>  AC_ARG_WITH(console-owner-file, AS_HELP_STRING([--with-console-owner-file=[filename]],[file whose owner determines current console owner]))
> +AC_ARG_WITH(launchd-agent-dir, AS_HELP_STRING([--with-launchd-agent-dir=[dirname]],[directory to put the launchd agent (session bus) (default: /Library/LaunchAgents)]))
> +AC_ARG_WITH(launchd-daemon-dir, AS_HELP_STRING([--with-launchd-daemon-dir=[dirname]],[directory to put the launchd daemon (system bus) (default: /Library/LaunchDaemons)]))

These are "underquoted". Please use one level of [] per level of () (wrap both the arguments of AC_ARG_WITH in one more [] than you have). AC_ARG_WITH([test_user]), below, is in the correct form.

(I know this is not consistently correct across all of configure.ac; I'm applying the rule that new code is held to higher standards than current code.)

You can use

AC_ARG_WITH([launchd_agent_dir], [help], [], [with_launchd_agent_dir=/Library/LaunchAgents])

to set a default if --with-launchd-agent-dir is not given (look at the AC_ARG_WITH([valgrind]) to see an example of setting a default like that).

I don't see any uses of $with_launchd_agent_dir at all? Please don't add options that don't actually do anything.

I don't see any uses of $LAUNCHD_DAEMON_DIR either, other than the message at the end.

@@ +1145,5 @@
>  
>  AC_SUBST(LAUNCHD_AGENT_DIR)
>  
> +#### Directory to place launchd daemon file
> +if test "x$with_launchd_daemon_dir" = "x"; then

Should be

AS_IF([test ...], [L_D_D=...], [L_D_D=...])

but if you set a default in the AC_ARG_WITH call and use AC_SUBST([LAUNCHD_DAEMON_DIR], [$with_launchd_daemon_dir]) then you won't need this block at all.

@@ +1867,4 @@
>  bus/messagebus
>  bus/messagebus-config
>  bus/org.freedesktop.dbus-session.plist
> +bus/org.freedesktop.dbus-system.plist

You haven't provided this file. The build will fail.

::: dbus/dbus-bus.c
@@ +520,5 @@
>    _DBUS_UNLOCK (bus);
> +#ifdef DBUS_ENABLE_LAUNCHD
> +  _dbus_verbose ("internal_bus_get(type=%d,private=%d) : found and registered connection to %s",
> +         type, private, address);
> +#endif

Is this extra verbosity really particularly useful?

If it is, enable it unconditionally. _dbus_verbose() compiles to nothing unless you ./configure --enable-verbose anyway.

If it isn't, remove it.

::: dbus/dbus-server-unix.c
@@ +266,3 @@
>            _dbus_set_bad_address (error, "launchd", "env", NULL);
>            return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
> +#endif

"#if 0" is never a good sign. If code is unnecessary or unwanted, remove it.

@@ +281,5 @@
> +            {
> +              _DBUS_ASSERT_ERROR_IS_SET(error);
> +              return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
> +            }
> +#endif

"#if 0" is never a good sign. If code is unnecessary or unwanted, remove it.

If you are deliberately ignoring an error, you need to free it; otherwise the memory is leaked.

@@ +286,2 @@
>          }
> +      // try a hardcoded traditional address as a fallback

You seem to be changing this function so that

    dbus-daemon --address=launchd:

is equivalent to

    dbus-daemon --address=unix:tmpdir=$DBUS_SESSION_SOCKET_DIR

but that makes no sense. If --address=launchd: is valid, you don't need to transform it. If it is invalid, it is correct for dbus-daemon --address=launchd: to exit unsuccessfully.

It is fine to have address strings that are defined to be incorrect/invalid. dbus-daemon --address=unix: isn't allowed either.

I don't think any of your changes to this function are actually necessary?

::: dbus/dbus-sysdeps-unix.c
@@ +3928,4 @@
>  
>    _DBUS_ASSERT_ERROR_IS_CLEAR (error);
>  
> +  const char *fromEnv = getenv (launchd_env_var);

I don't understand why you look for the same information in either this process's environment or the launchd environment? Surely one of them is correct, and the other isn't?

Use _dbus_getenv() so that you aren't deliberately bypassing the safety check that prevents trusting our environment when running setuid.

Our coding style is to use variable_names_like_this, not variableNamesLikeThis.

@@ +4136,5 @@
> +      return TRUE;
> +    }
> +// dbus can function without launchd like it does on other Unix versions, even when
> +// it will use launchd by default (on Mac). So there is no need to disable the
> +// non-launchd code path below.

If you are deliberately ignoring a non-null error, you need to free it; otherwise it's a memory leak.

Please use /* */ C-style comments, not // C++-style.

@@ +4137,5 @@
> +    }
> +// dbus can function without launchd like it does on other Unix versions, even when
> +// it will use launchd by default (on Mac). So there is no need to disable the
> +// non-launchd code path below.
> +#endif

Can't you just delete all this launchd-specific code, and fall through to the global default, which is normally "autolaunch:", but in configure.ac you changed it so it would be "launchd:env=DBUS_LAUNCHD_SESSION_BUS_SOCKET"?

(In reply to René J.V. Bertin from comment #0)
> patch against the master branch, #1e43857

Please use "git format-patch" to attach a complete patch with a description (<http://chris.beams.io/posts/git-commit/>).

> 1- being able to launch a session daemon when logged in remotely to OS
> X/macOS, i.e. when launchd cannot be used. In that case the OS is used as a
> traditional Unix, typically with X11 providing remote display, and there are
> no technical reasons why DBus wouldn't support this mode of operation
> ("shouldn't" may be a different thing).

If this is something you want, then you might want to make the default session bus connect address be

launchd:env=whatever,autolaunch:

so that the D-Bus client library will:

* first look for $DBUS_SESSION_BUS_ADDRESS, and if that is set, use it unconditionally (and if it fails, connecting will just fail - this is intended); if it is unset, continue
* then try launchd:env=whatever; if that succeeds, use it; if it fails, continue
* then try X11 autolaunch; if *that* succeeds, use it; if it fails, continue
* fail to connect

> Given the context the exact value of that entry is without importance. On
> Linux it would be set to "autolaunch:"; in the attached patch I set it to
> "launchd:env=DBUS_LAUNCHD_SESSION_BUS_SOCKET" because that appears to be an
> existing convention.

As far as I can see, if you set DBUS_SESSION_BUS_CONNECT_ADDRESS correctly, and delete the weird launchd-specific code so that it *is* important (in particular so it actually gets used), then everything will work better with less code. I like fixing bugs by deleting code.

> - should the org.freedesktop.dbus-system.plist launchd profile provided by
> my patch be installed by default or should it be optional or an operation to
> be done manually? Note that installing it doesn't load profile.

Sorry, I don't use or develop on a Mac. You will need to ask other Mac people what is most appropriate here, and bring us a consensus. For example, consider talking to the maintainers of dbus in Homebrew and/or Fink.

> - should _dbus_lookup_launchd_socket() indeed check the value of
> DBUS_LAUNCHD_SESSION_BUS_SOCKET in the environment, and if so should that
> value have priority over the value obtained from launchctl? The intention I
> had with the addition was to give a similar mechanism to override the
> "default" session bus as can be achieved on Linux by overriding
> DBUS_SESSION_BUS_ADDRESS.

I'm not sure why you wouldn't do this by overriding DBUS_SESSION_BUS_ADDRESS, exactly the same as you'd do on Linux?

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