On 1/24/21 8:53 AM, Luca Boccassi wrote: > Since NETLINK_GET_STRICT_CHK was enabled, the kernel rejects commands > that pass a prefix length, eg: > > ip route get `1.0.0.0/1 > Error: ipv4: Invalid values in header for route get request. > ip route get 0.0.0.0/0 > Error: ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4
Those are not the best responses from the kernel for the mask setting. I should have been clearer about src and dst masks. > > Since there's no point in setting a rtm_dst_len that we know is going > to be rejected, just force it to the right value if it's passed on > the command line. > > Bug-Debian: https://bugs.debian.org/944730 > Reported-By: Clément 'wxcafé' Hertling <wxc...@wxcafe.net> > Signed-off-by: Luca Boccassi <bl...@debian.org> > --- > As mentioned by David on: > > https://www.spinics.net/lists/netdev/msg624125.html > > ip/iproute.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/ip/iproute.c b/ip/iproute.c > index ebb5f160..3646d531 100644 > --- a/ip/iproute.c > +++ b/ip/iproute.c > @@ -2069,7 +2069,12 @@ static int iproute_get(int argc, char **argv) > if (addr.bytelen) > addattr_l(&req.n, sizeof(req), > RTA_DST, &addr.data, addr.bytelen); > - req.r.rtm_dst_len = addr.bitlen; > + if (req.r.rtm_family == AF_INET) > + req.r.rtm_dst_len = 32; > + else if (req.r.rtm_family == AF_INET6) > + req.r.rtm_dst_len = 128; > + else > + req.r.rtm_dst_len = addr.bitlen; > address_found = true; > } > argc--; argv++; > Since the kernel used to blindly ignore the mask, having iproute2 fix it up seems acceptable. I think it would be good to educate the user about invalid settings as well - get them to fix scripts and mind set.
