On 25/09/2019 17:09, Luigi Rizzo wrote: > As others have commented changing the ABI is a no-go. > However the command structure can be extended: > - define a new type, say DN_LINK64, and a new struct dn_link64 with a > 64-bit bw field; > - modify the kernel to accept the new type in addition to DN_LINK to > set link speed, > and reply with DN_LINK64 for links whose bandwidth cannot be > represented on 31 bits > (these must come from a userland that understands the new format, so > it is reasonable > to reply to queries with those) > - modify the ipfw libraries to, likewise, understand DN_LINK64 on > queries, and issue > DN_LINK64 when bw requests do not fit on 31 bits (on failure). > > An alternate, hack-ish approach would be to encode high speeds with > coarse granularity, > say speed 0x7fnnnnnn with n = 0.. 0xffffe representing speed in > Mbits/s (so that would give > you up to 16 Pbit/s) and reserve 0x7fffffff for the pre-existing > "2Gbit/s - 1" to avoid breaking > former userland that may pick that value.
Luigi, and everyone who commented, thank you very much for your suggestions. (Un)fortunately, my work decided to use a workaround rather than extending dummynet, so I won't be working on that. Sorry. I am cross-referencing this thread with an oldish bug for the same issue, just in case: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=194453 -- Andriy Gapon _______________________________________________ freebsd-net@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
