From 269bfff9bf4b2349248bb48ff61009cf1c5a4aec Mon Sep 17 00:00:00 2001 From: "Ondrej Zajicek (work)" Date: Wed, 16 Mar 2022 19:50:16 +0100 Subject: [PATCH] Lib: Allow use of 240.0.0.0/4 as a private range There were several requests to allow use of 240.0.0.0/4 as a private range, and Linux kernel already allows such routes, so perhaps we can allow that too. Thanks to Vincent Bernat and others for suggestion and patches. --- lib/ip.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/lib/ip.c b/lib/ip.c index fcc72caf..4c5fa47f 100644 --- a/lib/ip.c +++ b/lib/ip.c @@ -85,25 +85,29 @@ ip4_classify(ip4_addr ad) u32 a = _I(ad); u32 b = a >> 24U; - if (b && b <= 0xdf) + if (b < 0xe0) { - if (b == 0x7f) + if (b == 0x00) /* 0.0.0.0/8 This network */ + return IADDR_INVALID; + + if (b == 0x7f) /* 127.0.0.0/8 Loopback address */ return IADDR_HOST | SCOPE_HOST; - else if ((b == 0x0a) || - ((a & 0xffff0000) == 0xc0a80000) || - ((a & 0xfff00000) == 0xac100000)) + + if ((b == 0x0a) || /* 10.0.0.0/8 Private range */ + ((a & 0xffff0000) == 0xc0a80000) || /* 192.168.0.0/16 Private range */ + ((a & 0xfff00000) == 0xac100000)) /* 172.16.0.0/12 Private range */ return IADDR_HOST | SCOPE_SITE; - else - return IADDR_HOST | SCOPE_UNIVERSE; + + return IADDR_HOST | SCOPE_UNIVERSE; } - if (b >= 0xe0 && b <= 0xef) + if (b < 0xf0) /* 224.0.0.0/4 Multicast address */ return IADDR_MULTICAST | SCOPE_UNIVERSE; - if (a == 0xffffffff) + if (a == 0xffffffff) /* 255.255.255.255 Broadcast address */ return IADDR_BROADCAST | SCOPE_LINK; - return IADDR_INVALID; + return IADDR_HOST | SCOPE_SITE; /* 240.0.0.0/4 Reserved / private */ } int