/branches/18.06.1/target/linux/generic/backport-4.14/095-Allow-class-e-address-assignment-via-ifconfig-ioctl.patch |
@@ -0,0 +1,79 @@ |
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) ) == (long int)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 |
@@ -921,7 +921,7 @@ 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); |
@@ -932,6 +932,8 @@ 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 |
@@ -457,6 +457,8 @@ 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); |