Initial working code

README.md

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+# Endlessh: an SSH tarpit
+
+Endlessh is an SSH tarpit that *very* slowly sends a randomized SSH
+banner. It keeps clients locked up for hours or even days at at time.
+The idea is that you put your real SSH server on another port and let
+the script kiddies themselves stuck in this tarpit instead of bothering
+real server.
+
+Since the tarpit is in the banner before any cryptographic exchange
+occurs, this program doesn't depend on any cryptographic libraries. It's
+a simple, single-threaded, standalone C program. It uses `poll()` to
+trap multiple clients at a time.
+
+### Usage
+
+Usage information is printed with `-h`.
+
+```
+Usage: endlessh [-vh] [-d MSECS] [-m LIMIT] [-p PORT]
+  -d INT    Message millisecond delay [10000]
+  -h        Print this help message and exit
+  -m INT    Maximum number of clients [4096]
+  -p INT    Listening port [2222]
+  -v        Print diagnostics to standard output (repeatable)
+```
+
+The purpose of limiting the number of clients (`-m`) is to avoid tying
+up too many system resources with the tarpit. Clients beyond this limit
+are left in the accept queue, not rejected instantly.