38263 2010-04-28 07:42:08 -0700 [Gtk] DNS prefetching trying to resolve empty host names, spamming syslog 2011-05-12 06:12:46 -0700 1 1 1 Unclassified WebKit Page Loading 528+ (Nightly build) PC Linux RESOLVED FIXED P2 Normal --- 0 mike webkit-unassigned gustavo svillar xan.lopez oldest_to_newest 218393 0 mike 2010-04-28 07:42:08 -0700 WebKitGTK+ v1.2.0 (Ubuntu lucid libwebkit-1.0-2 1.2.0-1) Webkit is causing programs that embed it to spam syslog with this sort of thing: > Apr 29 00:17:01 localhost epiphany-browser: gethostby*.getanswer: asked for "", got "." > Apr 29 00:18:07 localhost epiphany-browser: last message repeated 527 times > Apr 29 00:19:08 localhost epiphany-browser: last message repeated 1178 times > Apr 29 00:20:09 localhost epiphany-browser: last message repeated 1300 times > Apr 29 00:21:18 localhost epiphany-browser: last message repeated 1341 times > Apr 29 00:22:27 localhost epiphany-browser: last message repeated 715 times > Apr 29 00:23:27 localhost epiphany-browser: last message repeated 1307 times > Apr 29 00:24:27 localhost epiphany-browser: last message repeated 863 times > Apr 29 00:25:27 localhost epiphany-browser: last message repeated 989 times > Apr 29 00:26:27 localhost epiphany-browser: last message repeated 534 times It looks like the DNS prefetching code is causing null/empty host names to be resolved, which explains the syslog entry. A typical stack trace is below. Note the call to g_resolver_lookup_by_name_async at the top with an empty hostname param. I'm not sure where the best place to guard against this is, perhaps both GIO and Soup should be ignoring/erroring when invoked to resolve an empty host name, but libwebkitgtk probably shouldn't be attempting to prefetch links without a valid URI host part anyway. #0 IA__g_resolver_lookup_by_name_async (resolver=0x20ef780, hostname=0x39cace0 "", cancellable=0x0, callback=0x7fac17c2a2a0, user_data=0x3516450) at /build/buildd/glib2.0-2.24.0/gio/gresolver.c:299 #1 0x00007fac17c2a18d in soup_address_resolve_async () from /usr/lib/libsoup-2.4.so.1 #2 0x00007fac1904ee49 in WebCore::prefetchDNS (hostname=<value optimised out>) at ../WebCore/platform/network/soup/DNSSoup.cpp:44 #3 0x00007fac18d11670 in WebCore::Chrome::mouseDidMoveOverElement ( this=0x7fabfd8e63c0, result=..., modifierFlags=27303232) at ../WebCore/page/Chrome.cpp:340 #4 0x00007fac18d2bd46 in WebCore::EventHandler::mouseMoved ( this=<value optimised out>, event=...) at ../WebCore/page/EventHandler.cpp:1332 #5 0x00007fac19084055 in webkit_web_view_motion_event ( widget=<value optimised out>, event=0x7fabe5c9a350) at ../WebKit/gtk/webkit/webkitwebview.cpp:654 #6 0x00007fac17fab0b8 in _gtk_marshal_BOOLEAN__BOXED (closure=0x1a09d40, return_value=0x7fffad3488b0, n_param_values=<value optimised out>, param_values=0x429a320, invocation_hint=<value optimised out>, marshal_data=0x7fac19083ff0) at /build/buildd/gtk+2.0-2.20.0/gtk/gtkmarshalers.c:84 #7 0x00007fac16d925de in IA__g_closure_invoke (closure=0x1a09d40, return_value=0x7fffad3488b0, n_param_values=2, param_values=0x429a320, ---Type <return> to continue, or q <return> to quit--- invocation_hint=0x7fffad348870) at /build/buildd/glib2.0-2.24.0/gobject/gclosure.c:767 #8 0x00007fac16da61dd in signal_emit_unlocked_R (node=0x1a09db0, detail=<value optimised out>, instance=<value optimised out>, emission_return=<value optimised out>, instance_and_params=<value optimised out>) at /build/buildd/glib2.0-2.24.0/gobject/gsignal.c:3286 #9 0x00007fac16da78b9 in IA__g_signal_emit_valist (instance=0x7fabe5e2c810, signal_id=<value optimised out>, detail=0, var_args=0x7fffad348a60) at /build/buildd/glib2.0-2.24.0/gobject/gsignal.c:2991 #10 0x00007fac16da8033 in IA__g_signal_emit (instance=0x20ef780, signal_id=60599520, detail=0) at /build/buildd/glib2.0-2.24.0/gobject/gsignal.c:3038 #11 0x00007fac180c1e9f in gtk_widget_event_internal (widget=0x7fabe5e2c810, event=0x7fabe5c9a350) at /build/buildd/gtk+2.0-2.20.0/gtk/gtkwidget.c:4951 #12 0x00007fac17fa3583 in IA__gtk_propagate_event (widget=0x7fabe5e2c810, event=0x7fabe5c9a350) at /build/buildd/gtk+2.0-2.20.0/gtk/gtkmain.c:2447 #13 0x00007fac17fa465b in IA__gtk_main_do_event (event=0x7fabe5c9a350) at /build/buildd/gtk+2.0-2.20.0/gtk/gtkmain.c:1647 #14 0x00007fac179c580c in gdk_event_dispatch (source=<value optimised out>, callback=<value optimised out>, user_data=<value optimised out>) at /build/buildd/gtk+2.0-2.20.0/gdk/x11/gdkevents-x11.c:2372 #15 0x00007fac166dd8c2 in g_main_dispatch (context=0x1a06310) ---Type <return> to continue, or q <return> to quit--- at /build/buildd/glib2.0-2.24.0/glib/gmain.c:1960 #16 IA__g_main_context_dispatch (context=0x1a06310) at /build/buildd/glib2.0-2.24.0/glib/gmain.c:2513 #17 0x00007fac166e1748 in g_main_context_iterate (context=0x1a06310, block=<value optimised out>, dispatch=<value optimised out>, self=<value optimised out>) at /build/buildd/glib2.0-2.24.0/glib/gmain.c:2591 #18 0x00007fac166e1c55 in IA__g_main_loop_run (loop=0x1ab9fb0) at /build/buildd/glib2.0-2.24.0/glib/gmain.c:2799 #19 0x00007fac17fa4af7 in IA__gtk_main () at /build/buildd/gtk+2.0-2.20.0/gtk/gtkmain.c:1219 #20 0x0000000000435423 in main (argc=1, argv=0x7fffad349fd8) at /build/buildd/epiphany-browser-2.30.2/src/ephy-main.c:741 218473 1 ap 2010-04-28 10:52:10 -0700 We have the following in DNSCFNet.cpp (used in CFNetwork-based ports): if (hostname.isEmpty()) return; 219321 2 54769 mike 2010-04-29 18:39:39 -0700 Created attachment 54769 Check hostname is non-empty before DNS prefetch Per Alexey's suggestion, this adds an empty check on the hostname string before calling Soup to prefetch. This patch fixes the problem for me. 299364 3 svillar 2010-10-26 03:07:33 -0700 (In reply to comment #2) > Created an attachment (id=54769) [details] > Check hostname is non-empty before DNS prefetch > > Per Alexey's suggestion, this adds an empty check on the hostname string before calling Soup to prefetch. > > This patch fixes the problem for me. Michael could you please include the proper changelog to the patch? There is some infor here http://webkit.org/coding/contributing.html. And do not forget to set the review flag to "?". Adding Xan to the Cc BTW 382771 4 gustavo 2011-04-09 05:14:36 -0700 Is this now obsolete? After 56128 the way this is done is completely different for the GTK+ port, and I was unable to identify at a glance if we would still be able to suffer from the same problem. Can the URL passed to prepareForURL lack a host? 402454 5 mike 2011-05-11 17:18:45 -0700 I'm not getting the syslog spam any more with webkit 1.4, soup 2.34 and glib 2.28, but I guess that's not to say the problem isn't still there. Gustavo, bug #56128 doesn't seem relevant? 402458 6 gustavo 2011-05-11 17:24:37 -0700 (In reply to comment #5) > Gustavo, bug #56128 doesn't seem relevant? I meant revision 56128: http://trac.webkit.org/changeset/56128 402538 7 mike 2011-05-11 18:37:13 -0700 (In reply to comment #6) > > I meant revision 56128: http://trac.webkit.org/changeset/56128 Oh, of course, thanks. Well, that revision uses soup_session_prepare_for_uri() for the DNS prefetching, and that function (in libsoup git master anyway) does a null check on the host, so this can probably be resolved as invalid or wontfix now. 402555 8 mike 2011-05-11 19:19:43 -0700 One note, possibly for another bug: Since HTMLAnchorElement::parseMappedAttribute calls ResourceHandle::prepareForURL, whenever an anchor element's href attribute is changed (which I assume also happens when the element is first parsed), loading a page will cause every anchor's href to be prefetched. This doesn't strike me as being very desirable, but I guess that is a WebKit issue in general. 402799 9 gustavo 2011-05-12 06:12:46 -0700 Well, fixed, just by a different patch, then =) 54769 2010-04-29 18:39:39 -0700 2010-06-11 11:46:50 -0700 Check hostname is non-empty before DNS prefetch webkit-empty-hostname.patch text/plain 467 mike LS0tIFdlYkNvcmUvcGxhdGZvcm0vbmV0d29yay9zb3VwL0ROU1NvdXAuY3BwLW9yaWcJMjAxMC0w NC0yOSAwMToyNjowNi4wNDg3MjU0MTkgKzEwMDAKKysrIFdlYkNvcmUvcGxhdGZvcm0vbmV0d29y ay9zb3VwL0ROU1NvdXAuY3BwCTIwMTAtMDQtMjkgMTQ6Mjg6NTUuNzMxNDcxMDI1ICsxMDAwCkBA IC0zNiw2ICszNiw4IEBACiB2b2lkIHByZWZldGNoRE5TKGNvbnN0IFN0cmluZyYgaG9zdG5hbWUp CiB7CiAjaWZkZWYgSEFWRV9MSUJTT1VQXzJfMjlfOTAKKyAgICBpZiAoaG9zdG5hbWUuaXNFbXB0 eSgpKQorICAgICAgICByZXR1cm47CiAgICAgU3RyaW5nIHVyaSA9ICJodHRwOi8vIitob3N0bmFt ZTsKICAgICBHT3duUHRyPFNvdXBVUkk+IHNvdXBVUkkoc291cF91cmlfbmV3KHVyaS51dGY4KCku ZGF0YSgpKSk7CiAgICAgLy8gV2UgbWF5IGdldCBpbnZhbGlkIGhvc3RuYW1lcywgc28gTlVMTC1j aGVjayBoZXJlLgo=