2574c86ce6
Backport net: Allow class-e address assignment via ifconfig ioctl While most distributions long ago switched to the iproute2 suite of utilities, which allow class-e (240.0.0.0/4) address assignment, distributions relying on busybox, toybox and other forms of ifconfig cannot assign class-e addresses without this kernel patch. While CIDR has been obsolete for 2 decades, and a survey of all the open source code in the world shows the IN_whatever macros are also obsolete... rather than obsolete CIDR from this ioctl entirely, this patch merely enables class-e assignment, sanely. https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git/commit/?id=65cab850f0eeaa9180bd2e10a231964f33743edf Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
80 lines
2.7 KiB
Diff
80 lines
2.7 KiB
Diff
From 46bf067870156abd61fe24d14c2486d15b8b502c Mon Sep 17 00:00:00 2001
|
|
From: Dave Taht <dave@taht.net>
|
|
Date: Fri, 14 Dec 2018 18:38:40 +0000
|
|
Subject: [PATCH 1/1] Allow class-e address assignment in ifconfig and early
|
|
boot
|
|
|
|
While the linux kernel became mostly "class-e clean" a decade ago,
|
|
and most distributions long ago switched to the iproute2 suite
|
|
of utilities, which allow class-e (240.0.0.0/4) address assignment,
|
|
distributions relying on busybox, toybox and other forms of
|
|
ifconfig cannot assign class-e addresses without this kernel patch.
|
|
|
|
With this patch, also, a boot command line on these addresses is feasible:
|
|
(ip=248.0.1.2::248.0.1.1:255.255.255.0).
|
|
|
|
While CIDR has been obsolete for 2 decades, and a survey of all the
|
|
userspace open source code in the world shows most IN_whatever macros
|
|
are also obsolete... rather than obsolete CIDR from this ioctl entirely,
|
|
this patch merely enables class-e assignment, sanely.
|
|
|
|
H/T to Vince Fuller and his original patch here:
|
|
https://lkml.org/lkml/2008/1/7/370
|
|
|
|
Signed-off-by: Dave Taht <dave.taht@gmail.com>
|
|
Reviewed-by: John Gilmore <gnu@toad.com>
|
|
---
|
|
include/uapi/linux/in.h | 8 ++++++--
|
|
net/ipv4/devinet.c | 4 +++-
|
|
net/ipv4/ipconfig.c | 2 ++
|
|
3 files changed, 11 insertions(+), 3 deletions(-)
|
|
|
|
--- a/include/uapi/linux/in.h
|
|
+++ b/include/uapi/linux/in.h
|
|
@@ -268,8 +268,12 @@ struct sockaddr_in {
|
|
#define IN_MULTICAST(a) IN_CLASSD(a)
|
|
#define IN_MULTICAST_NET 0xF0000000
|
|
|
|
-#define IN_EXPERIMENTAL(a) ((((long int) (a)) & 0xf0000000) == 0xf0000000)
|
|
-#define IN_BADCLASS(a) IN_EXPERIMENTAL((a))
|
|
+#define IN_BADCLASS(a) ((((long int) (a) ) == 0xffffffff)
|
|
+#define IN_EXPERIMENTAL(a) IN_BADCLASS((a))
|
|
+
|
|
+#define IN_CLASSE(a) ((((long int) (a)) & 0xf0000000) == 0xf0000000)
|
|
+#define IN_CLASSE_NET 0xffffffff
|
|
+#define IN_CLASSE_NSHIFT 0
|
|
|
|
/* Address to accept any incoming messages. */
|
|
#define INADDR_ANY ((unsigned long int) 0x00000000)
|
|
--- a/net/ipv4/devinet.c
|
|
+++ b/net/ipv4/devinet.c
|
|
@@ -941,7 +941,7 @@ static int inet_abc_len(__be32 addr)
|
|
{
|
|
int rc = -1; /* Something else, probably a multicast. */
|
|
|
|
- if (ipv4_is_zeronet(addr))
|
|
+ if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
|
|
rc = 0;
|
|
else {
|
|
__u32 haddr = ntohl(addr);
|
|
@@ -952,6 +952,8 @@ static int inet_abc_len(__be32 addr)
|
|
rc = 16;
|
|
else if (IN_CLASSC(haddr))
|
|
rc = 24;
|
|
+ else if (IN_CLASSE(haddr))
|
|
+ rc = 32;
|
|
}
|
|
|
|
return rc;
|
|
--- a/net/ipv4/ipconfig.c
|
|
+++ b/net/ipv4/ipconfig.c
|
|
@@ -429,6 +429,8 @@ static int __init ic_defaults(void)
|
|
ic_netmask = htonl(IN_CLASSB_NET);
|
|
else if (IN_CLASSC(ntohl(ic_myaddr)))
|
|
ic_netmask = htonl(IN_CLASSC_NET);
|
|
+ else if (IN_CLASSE(ntohl(ic_myaddr)))
|
|
+ ic_netmask = htonl(IN_CLASSE_NET);
|
|
else {
|
|
pr_err("IP-Config: Unable to guess netmask for address %pI4\n",
|
|
&ic_myaddr);
|