linux/include
Dave Taht 96125bf998 Allow 0.0.0.0/8 as a valid address range
The longstanding prohibition against using 0.0.0.0/8 dates back
to two issues with the early internet.

There was an interoperability problem with BSD 4.2 in 1984, fixed in
BSD 4.3 in 1986. BSD 4.2 has long since been retired.

Secondly, addresses of the form 0.x.y.z were initially defined only as
a source address in an ICMP datagram, indicating "node number x.y.z on
this IPv4 network", by nodes that know their address on their local
network, but do not yet know their network prefix, in RFC0792 (page
19).  This usage of 0.x.y.z was later repealed in RFC1122 (section
3.2.2.7), because the original ICMP-based mechanism for learning the
network prefix was unworkable on many networks such as Ethernet (which
have longer addresses that would not fit into the 24 "node number"
bits).  Modern networks use reverse ARP (RFC0903) or BOOTP (RFC0951)
or DHCP (RFC2131) to find their full 32-bit address and CIDR netmask
(and other parameters such as default gateways). 0.x.y.z has had
16,777,215 addresses in 0.0.0.0/8 space left unused and reserved for
future use, since 1989.

This patch allows for these 16m new IPv4 addresses to appear within
a box or on the wire. Layer 2 switches don't care.

0.0.0.0/32 is still prohibited, of course.

Signed-off-by: Dave Taht <dave.taht@gmail.com>
Signed-off-by: John Gilmore <gnu@toad.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-26 13:19:46 -07:00
..
acpi treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
asm-generic treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
clocksource treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
crypto treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
drm treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
dt-bindings Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-06-22 08:59:24 -04:00
keys treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
kvm treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
linux Allow 0.0.0.0/8 as a valid address range 2019-06-26 13:19:46 -07:00
math-emu math-emu: Use statement expressions to fix Wshift-count-overflow warning 2019-05-31 15:23:25 +08:00
media treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
memory treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
misc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2019-06-25 01:32:59 +02:00
pcmcia treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
ras
rdma SPDX update for 5.2-rc4 2019-06-08 12:52:42 -07:00
scsi treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 335 2019-06-05 17:37:06 +02:00
soc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
sound treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
target
trace page_pool: add tracepoints for page_pool with details need by XDP 2019-06-19 11:23:13 -04:00
uapi Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2019-06-25 01:32:59 +02:00
video treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
xen