liberalize interpretation of in_broadcast to avoid responding

to most UDP broadcasts

SCCS-vsn: sys/netinet/in.c 7.3

diff --git a/usr/src/sys/netinet/in.c b/usr/src/sys/netinet/in.c
index 5085f9e..b6e6f07 100644 (file)
--- a/usr/src/sys/netinet/in.c
+++ b/usr/src/sys/netinet/in.c
@@ -3,7 +3,7 @@
  * All rights reserved.  The Berkeley software License Agreement
  * specifies the terms and conditions for redistribution.
  *
  * All rights reserved.  The Berkeley software License Agreement
  * specifies the terms and conditions for redistribution.
  *

- *     @(#)in.c        7.2 (Berkeley) %G%
+ *     @(#)in.c        7.3 (Berkeley) %G%

  */
 
 #include "param.h"
  */
 
 #include "param.h"


@@ -374,7 +374,6 @@ in_ifinit(ifp, ia, sin)
                ia->ia_netbroadcast.s_addr =
                    htonl(ia->ia_net | (INADDR_BROADCAST &~ ia->ia_netmask));
        }
                ia->ia_netbroadcast.s_addr =
                    htonl(ia->ia_net | (INADDR_BROADCAST &~ ia->ia_netmask));
        }

-       splx(s);

        /*
         * Add route for the network.
         */
        /*
         * Add route for the network.
         */


@@ -390,6 +389,7 @@ in_ifinit(ifp, ia, sin)
                    (int)SIOCADDRT, RTF_UP);
        }
        ia->ia_flags |= IFA_ROUTE;
                    (int)SIOCADDRT, RTF_UP);
        }
        ia->ia_flags |= IFA_ROUTE;

+       splx(s);

        return (0);
 }
 
        return (0);
 }
 


@@ -409,21 +409,30 @@ in_iaonnetof(net)
 }
 
 /*
 }
 
 /*

- * Return 1 if the address is a local broadcast address.
+ * Return 1 if the address might be a local broadcast address.

  */
 in_broadcast(in)
        struct in_addr in;
 {
        register struct in_ifaddr *ia;
  */
 in_broadcast(in)
        struct in_addr in;
 {
        register struct in_ifaddr *ia;

+       u_long t;

 
        /*
         * Look through the list of addresses for a match
         * with a broadcast address.
         */
        for (ia = in_ifaddr; ia; ia = ia->ia_next)
 
        /*
         * Look through the list of addresses for a match
         * with a broadcast address.
         */
        for (ia = in_ifaddr; ia; ia = ia->ia_next)

-           if (((struct sockaddr_in *)&ia->ia_broadaddr)->sin_addr.s_addr ==
-               in.s_addr && (ia->ia_ifp->if_flags & IFF_BROADCAST))
+           if (ia->ia_ifp->if_flags & IFF_BROADCAST) {
+               if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr == in.s_addr)

                     return (1);
                     return (1);

+               /*
+                * Check for old-style (host 0) broadcast.
+                */
+               if ((t = ntohl(in.s_addr)) == ia->ia_subnet || t == ia->ia_net)
+                   return (1);
+       }
+       if (in.s_addr == INADDR_BROADCAST || in.s_addr == INADDR_ANY)
+               return (1);

        return (0);
 }
 #endif
        return (0);
 }
 #endif