On Tue, 19 Feb 2013 23:45:25 +0200 Denys Fedoryshchenko <de...@visp.net.lb> wrote:
> Hi > > I tried recently to write my own tool based on amazing libmnl (which > makes understanding of netlink - easy), written > by Pablo Neira Ayuso, to manage QoS in Linux and faced problem, which i > think probably > a bug in handling netlink messages in kernel. > > For example if i send message, RTM_NEWTCLASS, after attribute > TCA_OPTIONS i have nested attributes, > for example in HTB: TCA_HTB_PARMS, TCA_HTB_RTAB, TCA_HTB_CTAB. > libmnl, if i use nested attribute, adding a bit to it, by OR - > NLA_F_NESTED(1 << 15). > If i remove this flag - everything works fine. And here is the case, > iproute2 tools > just update length of TCA_OPTIONS, without setting flag, and it works > because of that fine too. > > So there is basically 3 solutions: > 1)New function in libmnl to do nested attributes without setting by OR > flag > 2)AND-ing attribute type in kernel to ignore nested flag > 3)Keeping as is, who cares? > Several legacy netlink interfaces don't use NESTED flag. These are by now enshrined in ABI and can't change. In code, that uses libmnl, I just manually clear the flag as needed and document why. This could be added to libmnl. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
