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| author | Thomas Haller <thaller@redhat.com> | 2014-04-03 16:09:51 (GMT) |
|---|---|---|
| committer | Thomas Haller <thaller@redhat.com> | 2014-04-04 14:31:36 (GMT) |
| commit | 5206c050504f8676a24854519b9c351470fb7cc6 (patch) | |
| tree | 0b48e1cab8dc2da96fef0096cc042ce3e4ef90c0 /lib/route | |
| parent | 34bfce62150d07cf9894f2d9cbd0c989a203ea52 (diff) | |
| download | libnl-5206c050504f8676a24854519b9c351470fb7cc6.zip libnl-5206c050504f8676a24854519b9c351470fb7cc6.tar.gz libnl-5206c050504f8676a24854519b9c351470fb7cc6.tar.bz2 | |
route/addr: only sent IFA_FLAGS when needed to workaround picky older kernels
Older kernels don't accept receiving unknown netlink attributes.
See net/core/rtnetlink.c, rtnetlink_rcv_msg(). This was fixed by kernel
commit 661d2967b3f1b34eeaa7e212e7b9bbe8ee072b59.
As a workaround, only set the additional attributes, when the user
provided flags that makes this necessary and useful.
https://github.com/thom311/libnl/issues/56
https://bugzilla.redhat.com/show_bug.cgi?id=1063885
Based-on-patch-by: Pavel Kankovsky <peak@argo.troja.mff.cuni.cz>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Thomas Haller <thaller@redhat.com>
Diffstat (limited to 'lib/route')
| -rw-r--r-- | lib/route/addr.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/lib/route/addr.c b/lib/route/addr.c index 97905f0..e6e91d2 100644 --- a/lib/route/addr.c +++ b/lib/route/addr.c @@ -598,7 +598,19 @@ static int build_addr_msg(struct rtnl_addr *tmpl, int cmd, int flags, NLA_PUT(msg, IFA_CACHEINFO, sizeof(ca), &ca); } - NLA_PUT_U32(msg, IFA_FLAGS, tmpl->a_flags); + if (tmpl->a_flags & ~0xFF) { + /* only set the IFA_FLAGS attribute, if they actually contain additional + * flags that are not already set to am.ifa_flags. + * + * Older kernels refuse RTM_NEWADDR and RTM_NEWROUTE messages with EINVAL + * if they contain unknown netlink attributes. See net/core/rtnetlink.c, which + * was fixed by kernel commit 661d2967b3f1b34eeaa7e212e7b9bbe8ee072b59. + * + * With this workaround, libnl will function correctly with older kernels, + * unless there is a new libnl user that wants to set these flags. In this + * case it's up to the user to workaround this issue. */ + NLA_PUT_U32(msg, IFA_FLAGS, tmpl->a_flags); + } *result = msg; return 0; |