[IPV4]: Enable use of 240/4 address space.

This short patch modifies the IPv4 networking to enable use of the
240.0.0.0/4 (aka "class-E") address space as propsed in the internet
draft draft-fuller-240space-00.txt.

Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 12 insertions, 11 deletions

diff --git a/include/linux/in.h b/include/linux/in.h
index 27d8a5ae9f75..70c6df882694 100644
--- a/include/linux/in.h
+++ b/include/linux/in.h
@@ -262,9 +262,10 @@ static inline bool ipv4_is_local_multicast(__be32 addr)
         return (addr & htonl(0xffffff00)) == htonl(0xe0000000);
 }
 
-static inline bool ipv4_is_badclass(__be32 addr)
+static inline bool ipv4_is_lbcast(__be32 addr)
 {
-        return (addr & htonl(0xf0000000)) == htonl(0xf0000000);
+        /* limited broadcast */
+        return addr == INADDR_BROADCAST;
 }
 
 static inline bool ipv4_is_zeronet(__be32 addr)
diff --git a/include/net/addrconf.h b/include/net/addrconf.h
index 8b1509bfc695..496503c03846 100644
--- a/include/net/addrconf.h
+++ b/include/net/addrconf.h
@@ -262,7 +262,7 @@ static inline int ipv6_isatap_eui64(u8 *eui, __be32 addr)
                   ipv4_is_private_172(addr) || ipv4_is_test_192(addr) ||
                   ipv4_is_anycast_6to4(addr) || ipv4_is_private_192(addr) ||
                   ipv4_is_test_198(addr) || ipv4_is_multicast(addr) ||
-                  ipv4_is_badclass(addr)) ? 0x00 : 0x02;
+                  ipv4_is_lbcast(addr)) ? 0x00 : 0x02;
         eui[1] = 0;
         eui[2] = 0x5E;
         eui[3] = 0xFE;
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index d18fdb102360..eebccdbdbaca 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -2266,7 +2266,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 
                                         while (ipv4_is_loopback(s) ||
                                                ipv4_is_multicast(s) ||
-                                               ipv4_is_badclass(s) ||
+                                               ipv4_is_lbcast(s) ||
                                                ipv4_is_zeronet(s) ||
                                                ipv4_is_local_multicast(s)) {
                                                 t = random32() % (imx - imn) + imn;
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 62bd791c204e..8987046d97f3 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -176,7 +176,7 @@ static inline unsigned __inet_dev_addr_type(struct net *net,
         unsigned ret = RTN_BROADCAST;
         struct fib_table *local_table;
 
-        if (ipv4_is_zeronet(addr) || ipv4_is_badclass(addr))
+        if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
                 return RTN_BROADCAST;
         if (ipv4_is_multicast(addr))
                 return RTN_MULTICAST;
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index fc0145385e80..f80c761ea0bb 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1154,7 +1154,7 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
                 return;
 
         if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev)
-            || ipv4_is_multicast(new_gw) || ipv4_is_badclass(new_gw)
+            || ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw)
             || ipv4_is_zeronet(new_gw))
                 goto reject_redirect;
 
@@ -1634,7 +1634,7 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
         if (in_dev == NULL)
                 return -EINVAL;
 
-        if (ipv4_is_multicast(saddr) || ipv4_is_badclass(saddr) ||
+        if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
             ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
                 goto e_inval;
 
@@ -1891,7 +1891,7 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
            by fib_lookup.
          */
 
-        if (ipv4_is_multicast(saddr) || ipv4_is_badclass(saddr) ||
+        if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
             ipv4_is_loopback(saddr))
                 goto martian_source;
 
@@ -1904,7 +1904,7 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
         if (ipv4_is_zeronet(saddr))
                 goto martian_source;
 
-        if (ipv4_is_badclass(daddr) || ipv4_is_zeronet(daddr) ||
+        if (ipv4_is_lbcast(daddr) || ipv4_is_zeronet(daddr) ||
             ipv4_is_loopback(daddr))
                 goto martian_destination;
 
@@ -2125,7 +2125,7 @@ static inline int __mkroute_output(struct rtable **result,
                 res->type = RTN_BROADCAST;
         else if (ipv4_is_multicast(fl->fl4_dst))
                 res->type = RTN_MULTICAST;
-        else if (ipv4_is_badclass(fl->fl4_dst) || ipv4_is_zeronet(fl->fl4_dst))
+        else if (ipv4_is_lbcast(fl->fl4_dst) || ipv4_is_zeronet(fl->fl4_dst))
                 return -EINVAL;
 
         if (dev_out->flags & IFF_LOOPBACK)
@@ -2276,7 +2276,7 @@ static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
         if (oldflp->fl4_src) {
                 err = -EINVAL;
                 if (ipv4_is_multicast(oldflp->fl4_src) ||
-                    ipv4_is_badclass(oldflp->fl4_src) ||
+                    ipv4_is_lbcast(oldflp->fl4_src) ||
                     ipv4_is_zeronet(oldflp->fl4_src))
                         goto out;