use Net::IP;
+require "sys/ioctl.ph";
+use Socket qw(IPPROTO_IP);
+
+use constant IFF_UP => 1;
+use constant IFNAMSIZ => 16;
+
# host network related utility functions
our $ipv4_reverse_mask = [
return $cidr_obj->overlaps($ip_obj) == $Net::IP::IP_B_IN_A_OVERLAP;
}
+# struct ifreq { // FOR SIOCGIFFLAGS:
+# char ifrn_name[IFNAMSIZ]
+# short ifru_flags
+# };
+my $STRUCT_IFREQ_SIOCGIFFLAGS = 'Z' . IFNAMSIZ . 's1';
+sub get_active_interfaces {
+ # Use the interface name list from /proc/net/dev
+ open my $fh, '<', '/proc/net/dev'
+ or die "failed to open /proc/net/dev: $!\n";
+ # And filter by IFF_UP flag fetched via a PF_INET6 socket ioctl:
+ socket my $sock, PF_INET6, SOCK_DGRAM, &IPPROTO_IP
+ or die "failed to open socket\n";
+
+ my $ifaces = [];
+ while(defined(my $line = <$fh>)) {
+ next if $line !~ /^\s*([^:\s]+):/;
+ my $ifname = $1;
+ my $ifreq = pack($STRUCT_IFREQ_SIOCGIFFLAGS, $1, 0);
+ if (!defined(ioctl($sock, &SIOCGIFFLAGS, $ifreq))) {
+ warn "failed to get interface flags for: $ifname\n";
+ next;
+ }
+ my ($name, $flags) = unpack($STRUCT_IFREQ_SIOCGIFFLAGS, $ifreq);
+ push @$ifaces, $1 if ($flags & IFF_UP);
+ }
+ close $fh;
+ close $sock;
+ return $ifaces;
+}
+
1;