From: Dave Taht <dave.taht@xxxxxxxxx>
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.
Signed-off-by: Dave Taht <dave.taht@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
---
include/uapi/linux/in.h | 10 +++++++---
net/ipv4/devinet.c | 5 +++--
net/ipv4/ipconfig.c | 2 ++
3 files changed, 12 insertions(+), 5 deletions(-)
diff --git a/include/uapi/linux/in.h b/include/uapi/linux/in.h
index eaf94919291a..550b234be4a1 100644
--- a/include/uapi/linux/in.h
+++ b/include/uapi/linux/in.h
@@ -264,10 +264,14 @@ struct sockaddr_in {
#define IN_CLASSD(a) ((((long int) (a)) & 0xf0000000) == 0xe0000000)
#define IN_MULTICAST(a) IN_CLASSD(a)
-#define IN_MULTICAST_NET 0xF0000000
+#define IN_MULTICAST_NET 0xe0000000
-#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)
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index f08f984ebc56..32335ed0e9fe 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -898,17 +898,18 @@ 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);
-
if (IN_CLASSA(haddr))
rc = 8;
else if (IN_CLASSB(haddr))
rc = 16;
else if (IN_CLASSC(haddr))
rc = 24;
+ else if (IN_CLASSE(haddr))
+ rc = 32;
}
return rc;
diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c
index d278b06459ac..ecf19f7ab5fd 100644
--- a/net/ipv4/ipconfig.c
+++ b/net/ipv4/ipconfig.c
@@ -455,6 +455,8 @@ 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);
--
2.20.1
