On Fri, Jul 25, 2014 at 4:33 AM, Corinna Vinschen <vinschen@xxxxxxxxxx> wrote: > > [...] or the ncat tool from http://nmap.org/ as used on > Fedora, both of which provide -U for AF_UNIX sockets. > ncat has a different problem: it doesn't handle FD closures properly. Grab yourself a decent-sized (a MB or two) data file and try this (this is on Fedora 20): $ ncat -l 127.0.0.1 1234 <testdata & $ ncat 127.0.0.1 1234 >testcopy This will transfer the full file then hang indefinitely waiting for stdin to close: ^C $ ls -l testdata testcopy -rw-r--r-- 1 dtucker dtucker 5485744 Jul 26 00:45 testcopy -rwxr-xr-x 1 dtucker dtucker 5485744 Jul 26 00:43 testdata If you try to work around this by redirecting stdin to /dev/null it'll exit after one pass through the copy loop even though the TCP stream it's writing hasn't been completely written: $ ncat -l 127.0.0.1 1234 <testdata & $ ncat 127.0.0.1 1234 >testcopy </dev/null $ ls -l testdata testcopy -rw-r--r-- 1 dtucker dtucker 16384 Jul 26 00:48 testcopy -rwxr-xr-x 1 dtucker dtucker 5485744 Jul 26 00:43 testdata A had a look around and it seems their abstraction layer doesn't allow them to do this. They have --send-only and --recv-only which seem like hacks around the problem, but no other nc implementation either needs or understands them. Damien suggested shipping OpenBSD's nc in contrib and I made fun of him for it, but he may have been right (as usual :-) -- Darren Tucker (dtucker at zip.com.au) GPG key 8FF4FA69 / D9A3 86E9 7EEE AF4B B2D4 37C9 C982 80C7 8FF4 FA69 Good judgement comes with experience. Unfortunately, the experience usually comes from bad judgement. _______________________________________________ openssh-unix-dev mailing list openssh-unix-dev@xxxxxxxxxxx https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev
