ifconfig(8) diff to properly resolve netmasks

[Vladimir Kirillov]

Hello t...@!

This diff prevents setting bogus netmasks, which are retrieved via
gethostbyname()

i.e.:

root ~ 0 # grep mynet /etc/networks
mynet                   255.255.0.0
root ~ 0 # ifconfig vether0 inet 10.0.0.100 netmask mynet
root ~ 0 # ifconfig vether0
vether0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        lladdr 00:bd:2d:ce:3f:01
        priority: 0
        groups: vether
        media: Ethernet autoselect
        status: active
        inet 10.0.0.100 netmask 0x43d74184 broadcast 190.40.190.127

now:

root src/sbin/ifconfig 0 # obj/ifconfig vether0 inet 10.0.0.100 netmask mynet 
root src/sbin/ifconfig 0 # obj/ifconfig vether0                                 
 
vether0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        lladdr 00:bd:2d:ce:3f:01
        priority: 0
        groups: vether
        media: Ethernet autoselect
        status: active
        inet 10.0.0.100 netmask 0xffff0000 broadcast 10.0.255.255

Index: ifconfig.c
===================================================================
RCS file: /cvs/src/sbin/ifconfig/ifconfig.c,v
retrieving revision 1.226
diff -u -p -r1.226 ifconfig.c
--- ifconfig.c  14 Dec 2009 17:22:58 -0000      1.226
+++ ifconfig.c  19 Dec 2009 13:39:51 -0000
@@ -4438,10 +4438,10 @@ in_getaddr(const char *s, int which)
                in_getprefix(p, MASK);
                memcpy(&sin->sin_addr, &tsin.sin_addr, sizeof(sin->sin_addr));
        } else if (inet_aton(s, &sin->sin_addr) == 0) {
-               if ((hp = gethostbyname(s)))
-                       memcpy(&sin->sin_addr, hp->h_addr, hp->h_length);
-               else if ((np = getnetbyname(s)))
+               if (which == MASK && (np = getnetbyname(s)))
                        sin->sin_addr = inet_makeaddr(np->n_net, INADDR_ANY);
+               else if ((hp = gethostbyname2(s, AF_INET)))
+                       memcpy(&sin->sin_addr, hp->h_addr, hp->h_length);
                else
                        errx(1, "%s: bad value", s);
        }