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.
This commit is contained in:
Ondrej Zajicek (work) 2022-03-16 19:50:16 +01:00
parent c3828879a3
commit 269bfff9bf

View file

@ -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