From: Luca Boccassi Date: Sun, 24 Jan 2021 17:36:58 +0000 (+0000) Subject: iproute: force rtm_dst_len to 32/128 X-Git-Tag: v5.11.0~15 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5a37254b71249bfb73d44d6278d767a6b127a2f9;p=thirdparty%2Fiproute2.git iproute: force rtm_dst_len to 32/128 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 Signed-off-by: Luca Boccassi Signed-off-by: Stephen Hemminger --- diff --git a/ip/iproute.c b/ip/iproute.c index ebb5f160f..8d4d2ff87 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++;