Bug#327031: ifdown routine only works on Linux

[Petter Reinholdtsen]

[Robert Millan]
> It seems on kFreeBSD, some interfaces are "phantom" ones.  They
> exist, and are detected by the numif assignment in ifdown.c, but
> their ifr_name component only contains trash (on my system, there
> are 2 normal interfaces, and 8 "phantom" ones).

Are these interfaces up?  Perhaps this patch solve the problem, by
limiting the 'ifconfig down' to the interfaces currently up?

Index: src/ifdown.c
===================================================================
--- src/ifdown.c        (revisjon 70)
+++ src/ifdown.c        (arbeidskopi)
@@ -61,10 +61,12 @@
                                continue;
                        if (strchr(ifr[i].ifr_name, ':') != NULL)
                                continue;
-                       ifr[i].ifr_flags &= ~(IFF_UP);
-                       if (ioctl(fd, SIOCSIFFLAGS, &ifr[i]) < 0) {
-                               fprintf(stderr, "ifdown: shutdown ");
-                               perror(ifr[i].ifr_name);
+                       if (ifr[i].ifr_flags & IFF_UP) {
+                               ifr[i].ifr_flags &= ~(IFF_UP);
+                               if (ioctl(fd, SIOCSIFFLAGS, &ifr[i]) < 0) {
+                                       fprintf(stderr, "ifdown: shutdown ");
+                                       perror(ifr[i].ifr_name);
+                               }
                        }
                }
        }

The patch is completely untested, and written based on the info I
found in one of the stevens books.