Patrick McHardy wrote: > Patrick McHardy wrote: > >>I took on Ben's challenge to increase the number of possible routing tables, >>these are the resulting patches. >> >>The table IDs are changed to 32 bit values and are contained in a new netlink >>routing attribute. For compatibility rtm_table in struct rtmsg can still be >>used to access the first 255 tables and contains the low 8 bit of the table >>ID in case of dumps. Unfortunately there are no invalid values for rtm_table, >>so the best userspace can do in case of a new iproute version that tries to >>access tables > 255 on an old kernel is to use RTM_UNSPEC (0) for rtm_table, >>which will make the kernel allocate an empty table instead of silently adding >>routes to a more or less random table. The iproute patch will follow shortly. > > > Actually that last part wasn't entirely true. The last couple of > releases of the kernel include the inet_check_attr function, > which (unwillingly) breaks with the tradition of ignoring > unknown attributes and signals an error on receiving the RTA_TABLE > attribute. So the iproute patch only includes the RTA_TABLE > attribute when the table ID is > 255, in which case rtm_table > is set to RT_TABLE_UNSPEC. Old kernels will still have the > behaviour I described above. The patch has been tested to > behave as expected on both patched and unpatched kernels.
That wasn't entirely true either, its not inet_check_attr but rtnetlink_rcv_message that aborts, and it does this on all kernels. Somehow I thought unknown attributes were usually ignored .. anyway, this is a good thing in this case as it will avoid unexpected behaviour and simply return an error on kernels where this feature is not available. - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
