4e3819cf |
1 | #! /bin/perl |
2 | |
3 | use Socket; |
4 | |
5 | # --- Read the network interface to steal --- |
6 | |
7 | $netif = shift; |
8 | |
9 | # --- Start a child if so requested --- |
10 | |
11 | if (@ARGV) { |
12 | socketpair(ONE, TOTHER, PF_UNIX, SOCK_STREAM, 0) |
13 | or die "socketpair: $!"; |
14 | $kid = fork(); |
15 | defined $kid or die "fork: $!"; |
16 | if ($kid) { |
17 | close ONE; |
18 | open STDIN, ">&TOTHER" or die "dup stdin: $!"; |
19 | open STDOUT, ">&TOTHER" or die "dup stdout: $!"; |
20 | close TOTHER; |
21 | exec @ARGV; |
22 | die "exec: $!"; |
23 | } |
24 | close TOTHER; |
25 | open STDIN, ">&ONE" or die "dup stdin: $!"; |
26 | open STDOUT, ">&ONE" or die "dup stdout: $!"; |
27 | close ONE; |
28 | } |
29 | |
30 | # --- Now start work on this --- |
31 | |
32 | open NETIF, "+> $netif" or die "open($netif): $!"; |
33 | |
34 | for (;;) { |
35 | $rfd = ''; |
36 | vec($rfd, fileno(STDIN), 1) = 1; |
37 | vec($rfd, fileno(NETIF), 1) = 1; |
38 | select($rfd, undef, undef, undef) or die "select: $!"; |
39 | |
40 | if (vec($rfd, fileno(NETIF), 1)) { |
41 | sysread(NETIF, $pkt, 65536); |
42 | $pkt = pack("n", length($pkt)) . $pkt; |
43 | syswrite(STDOUT, $pkt, length($pkt)); |
44 | } |
45 | if (vec($rfd, fileno(STDIN), 1)) { |
46 | sysread(STDIN, $clen, 2) or die "tunnel has vanished: $!"; |
47 | $len = unpack("n", $clen); |
48 | sysread(STDIN, $pkt, $len); |
49 | syswrite(NETIF, $pkt, length($pkt)); |
50 | } |
51 | } |