[PATCHES] symbol visibility
Hi,
while looking through the TODO list for 0.7 [1], I decided that I should
contribute a bit, especially as it was me, that complained about the
long list of exported symbols by libnm-glib and libnm-util.
So I went ahead and studied the docs a bit.
There are basically two approaches, how to trim down the list of
exported symbols:
a) GCC's visibility support [2]
GCC extension, mostly used by C++ libraries
b) ld linker/version scripts [3]
b.1) either directly via LDFLAGS -Wl,--version-script
b.2) or indirectly via libtools -export-symbols $FILE or
-export-symbols-regex, which will create a version script on the fly.
Before trying to evaluate which approach is best, I analyzed the list of
exported symbols (see attached *.symbols files) and checked which
symbols are not part of the public API (see attached *.diff files).
There are basically 5 ways
GCC visibility
1.) Use -fvisibility=default (all symbols are exported by default) and
augment all function declarations, which shall not be exported with
__attribute__ ((visibility("hidden")))
Does not work, as we have autogenerated files, where we cannot add the
visibility attribute.
2.) Use -fvisibility=hidden (all symbols are hidden by default) and
augment all function declarations, which shall be exported with
__attribute__ ((visibility("default"))).
Lots of code changes in the header files. To be manageable we'd have to
define a macro like DLLEXPORT. All installed header files would either
have to define such a macro or we would have to create a new header file
(like visibility.h) which contains this macro and all other header files
include that. Imho quite cumbersome
libtool
3.) -export-symbols-regex:
as you can see from the attached symbols and diff files, we can't use a
common prefix like nm_.*. We'd have to rename private function to
something like _nm_* -> looks of code changes.
4.) -export-symbols $FILE
List all exported symbols in a separate file and pass it to libtool.
I chatted with libtool's upstream a bit, and he recommended though, to
directly use a ld version script. as this provides the most flexibility,
5.) LDFLAGS = -Wl,--version-script=$FILE
That's the way I implemented it in the patch. I listed each exported
symbol explicitely (although the version script syntax would allow
regexes). See patch 0001 and 0002 for the details.
Imho this is the nicest and cleanest approaches which requires the least
changes.
I generated the version scripts automatically (by using objdump and
grepping for the symbols in the installed header files, dropping all
symbols which are not part of the public API), so a careful review would
be very appreciated.
NOTE: I didn't enable symbol versioning as I didn't see the need for it
yet, I only used the version script to control the list of exported symbols
After applying 0001 and 0002, the test-crypto binary will no longer
build, as it uses private symbols from libnm-util. I simply removed it
in patch 0003. An alternative would be, to add crypto.c and
crypto_(gnutls|nss).c to test_crypto_SOURCES.
If someone has a need for this binary, I could change that.
Comments and feedback welcome.
Michael
P.S: As I have svn commit access now, I could commit those patches
myself, if you ack the changes.
[1] http://live.gnome.org/NetworkManager07Release
[2] http://gcc.gnu.org/wiki/Visibility
[3]
http://www.redhat.com/docs/manuals/enterprise/RHEL-4-Manual/gnu-linker/version.html
--
Why is it that all of the instruments seeking intelligent life in the
universe are pointed away from Earth?
From d452ca3f3f2a9ea6fda182498128b16ea2467990 Mon Sep 17 00:00:00 2001
From: Michael Biebl <[EMAIL PROTECTED]>
Date: Wed, 13 Aug 2008 02:42:02 +0200
Subject: [PATCH] symbol visibility
Use a ld version script for libnm-util, libnm_glib and libnm_glib_vpn to
control the list of exported symbols.
---
libnm-glib/Makefile.am |5 -
libnm-util/Makefile.am |5 +++--
2 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/libnm-glib/Makefile.am b/libnm-glib/Makefile.am
index d3c73b6..a8b4aca 100644
--- a/libnm-glib/Makefile.am
+++ b/libnm-glib/Makefile.am
@@ -91,6 +91,8 @@ libnm_glib_la_LIBADD = \
$(GCONF_LIBS) \
$(GNOME_KEYRING_LIBS)
+libnm_glib_la_LDFLAGS = -Wl,--version-script=$(srcdir)/libnm_glib.ver
+
noinst_PROGRAMS = libnm-glib-test
libnm_glib_test_SOURCES = libnm-glib-test.c
@@ -101,6 +103,7 @@ libnm_glib_test_LDADD = libnm_glib.la $(top_builddir)/libnm-util/libnm-util.la $
libnm_glib_vpn_la_SOURCES = nm-vpn-plugin.c nm-vpn-plugin-ui-interface.c
libnm_glib_vpn_la_CFLAGS = $(GLIB_CFLAGS) $(DBUS_CFLAGS)
libnm_glib_vpn_la_LIBADD = $(top_builddir)/libnm-util/libnm-util.la $(GLIB_LIBS) $(DBUS_LIBS)
+libnm_glib_vpn_la_LDFLAGS = -Wl,--version-script=$(srcdir)/libnm_glib_vpn.ver
nm-client-bindings.h: $(top_srcdir)/introspection/nm-manager-client.xml
@@ -153,7 +156,7 @@ pkgconfig_DATA = libnm_glib.pc libnm_glib_vpn.pc
DISTCLEANFILES = libnm_glib.pc lib
Re: vpn connection failure
On Tue, 2008-08-12 at 17:40 -0400, Dan Williams wrote: > On Tue, 2008-08-12 at 17:27 -0400, Eric Beversluis wrote: > > I'm trying to get VPN to work on my Ubuntu 7.04 installation with > > NetworkManager Applet 0.6.4. I'm using the same IP address, user name > > and password that works on a vpn connection on my Windows box, but here > > I keep getting this error message: > > > > "VPN Connection Failure > > Could not start VPN connection due to a connection error. > > VPN Connection failed." > > > > I can't seem to find anything on the NetworkManager page or elsewhere > > that gives any instructions on configuring the VPN connection. Can > > anyone help with this? (PS--there is no firewall running on the box > > right now and still no connection.) > > Which VPN plugin? openvpn, vpnc, or pptp? Also, if openvpn, what > version of openvpn are you using? > > Dan I don't see anywhere in the config window where it tells me. I think I have a pptp plugin. On the connection page, the only connection type option is Windows pptp, which is what I want to use. Just today I tried the openvpn plugin (no idea which version). But the openvpn plugin didn't make any difference in the behavior or the config options. I don't find anywhere on the NetworkManager help page that tells me anything about plugins, as I don't find anything that guides me through the various config possibilities that appear on the VPN config dialog. Am I missing a source of info somewhere? Thanks. EB ___ NetworkManager-list mailing list NetworkManager-list@gnome.org http://mail.gnome.org/mailman/listinfo/networkmanager-list
Re: vpn connection failure
On Tue, 2008-08-12 at 17:27 -0400, Eric Beversluis wrote: > I'm trying to get VPN to work on my Ubuntu 7.04 installation with > NetworkManager Applet 0.6.4. I'm using the same IP address, user name > and password that works on a vpn connection on my Windows box, but here > I keep getting this error message: > > "VPN Connection Failure > Could not start VPN connection due to a connection error. > VPN Connection failed." > > I can't seem to find anything on the NetworkManager page or elsewhere > that gives any instructions on configuring the VPN connection. Can > anyone help with this? (PS--there is no firewall running on the box > right now and still no connection.) Which VPN plugin? openvpn, vpnc, or pptp? Also, if openvpn, what version of openvpn are you using? Dan ___ NetworkManager-list mailing list NetworkManager-list@gnome.org http://mail.gnome.org/mailman/listinfo/networkmanager-list
vpn connection failure
I'm trying to get VPN to work on my Ubuntu 7.04 installation with NetworkManager Applet 0.6.4. I'm using the same IP address, user name and password that works on a vpn connection on my Windows box, but here I keep getting this error message: "VPN Connection Failure Could not start VPN connection due to a connection error. VPN Connection failed." I can't seem to find anything on the NetworkManager page or elsewhere that gives any instructions on configuring the VPN connection. Can anyone help with this? (PS--there is no firewall running on the box right now and still no connection.) Thanks. ___ NetworkManager-list mailing list NetworkManager-list@gnome.org http://mail.gnome.org/mailman/listinfo/networkmanager-list
Recent NM API changes
Hi,
Two API changes recently...
1) The OpenVPN plugin has had some key name changes:
proto -> proto-tcp
dev -> tap-dev
shared-key -> static-key
shared-key-direction -> static-key-direction
2) The vpn-properties setting was merged with the vpn setting. The vpn
setting's 'data' member (analogous to the vpn-properties setting's
'data' member) is type "a{ss}", i.e. all VPN-service-specific property
values are now strings, instead of variants. This change was made to
allow system settings plugins that cannot easily represent typed data to
save out vpn specific properties. In reality, most properties for the
openvpn, pptp, and vpnc plugins were already strings. Since the VPN
plugins already needed to know what type the value was, it's quite easy
for them to handle the conversion.
3) In libnm-util, the NMSettingVPNProperties class has been removed, as
it was merged with NMSettingVPN as described above.
I've updated the gnome applet to convert the VPN settings to the new
format.
Dan
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Re: wha is ipv4 prefix?? (why not netmask)
On Fri, Aug 8, 2008 at 5:56 PM, Dan Williams <[EMAIL PROTECTED]> wrote: > On Thu, 2008-08-07 at 19:11 -0400, Nathaniel McCallum wrote: >> Derek Atkins wrote: >> > Miguel Angel Cañedo <[EMAIL PROTECTED]> writes: >> > >> > >> >> I was pulling my hair trying to set static ipv4 settings. >> >> Until I realized that NM 0.7 asks for PREFIX instead of NETMASK >> >> >> >> Now, my netmask should be 255.255.0.0 >> >> How do I transalte that into the Prefix? >> >> >> > >> > /16 ? >> > >> I also thought the wording was less-than-clear. > > We should really be accepting a netmask in that field and autoconverting > to a prefix when you hit tab or move out of the field. There are quite > a few rough edges to the connection editor that we do need to fix up. One less rough edge, I renamed the column header to "Netmask" (from "Prefix") and the column now accepts both prefix length and netmask. Tambet ___ NetworkManager-list mailing list NetworkManager-list@gnome.org http://mail.gnome.org/mailman/listinfo/networkmanager-list
