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 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. Print a warning to stderr to notify users. Bug-Debian: https://bugs.debian.org/944730 Reported-By: Clément 'wxcafé' Hertling <wxc...@wxcafe.net> Signed-off-by: Luca Boccassi <bl...@debian.org> --- v2: added a warning ip/iproute.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/ip/iproute.c b/ip/iproute.c index ebb5f160..8d4d2ff8 100644 --- a/ip/iproute.c +++ b/ip/iproute.c @@ -2069,7 +2069,18 @@ 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 && addr.bitlen != 32) { + fprintf(stderr, + "Warning: /%u as prefix is invalid, only /32 (or none) is supported.\n", + addr.bitlen); + req.r.rtm_dst_len = 32; + } else if (req.r.rtm_family == AF_INET6 && addr.bitlen != 128) { + fprintf(stderr, + "Warning: /%u as prefix is invalid, only /128 (or none) is supported.\n", + addr.bitlen); + req.r.rtm_dst_len = 128; + } else + req.r.rtm_dst_len = addr.bitlen; address_found = true; } argc--; argv++; -- 2.29.2
