Add unix domain socket support to redbean

2025-05-22 21:32:31 +00:00 · 2022-06-22 03:04:25 -07:00 · 2022-06-22 03:04:25 -07:00 · fc097ac275
commit fc097ac275
parent 4b23985b7f
25 changed files with 594 additions and 172 deletions
--- a/tool/net/demo/unix-unix.lua
+++ b/tool/net/demo/unix-unix.lua
@ -0,0 +1,89 @@
+-- UNIX Domain Sockets Example
+
+-- So we can detect that child died.
+died = false
+function OnSigchld(sig)
+   died = true
+   unix.wait() -- Prevent it from becoming a zombie
+end
+assert(unix.sigaction(unix.SIGCHLD, OnSigchld))
+
+-- So keyboard interurpts only go to subprocess.
+oldint = assert(unix.sigaction(unix.SIGINT, unix.SIG_IGN))
+oldquit = assert(unix.sigaction(unix.SIGQUIT, unix.SIG_IGN))
+
+-- UNIX domain sockets need a file
+tmpdir = os.getenv('TMPDIR') or '/tmp'
+unixpath = '%s/redbean-unix.sock.%d' % {tmpdir, unix.getpid()}
+
+-- Create child process which is the server.
+child = assert(unix.fork())
+if child == 0 then
+   server = assert(unix.socket(unix.AF_UNIX, unix.SOCK_STREAM))
+   assert(unix.setsockopt(server, unix.SOL_SOCKET, unix.SO_RCVTIMEO, 2))
+   assert(unix.bind(server, unixpath))
+   assert(unix.listen(server))
+   client = assert(unix.accept(server))
+   data = assert(unix.read(client))
+   assert(data == 'ping!')
+   assert(assert(unix.write(client, 'pong!')) == 5)
+   assert(unix.close(client))
+   unix.exit(0)
+end
+
+-- Wait for the child to create the the socket file.
+function FileExists(path)
+   st, err = unix.stat(path)
+   return not err
+end
+expobackoff = 1
+while not died do
+   if FileExists(unixpath) then
+      break
+   else
+      expobackoff = expobackoff << 1
+      unix.nanosleep(expobackoff // 1000000000,
+                     expobackoff % 1000000000)
+   end
+end
+
+-- Now connect to the socket.
+if not died then
+   client = assert(unix.socket(unix.AF_UNIX, unix.SOCK_STREAM))
+   assert(unix.connect(client, unixpath))
+   assert(assert(unix.write(client, 'ping!')) == 5)
+   data = assert(unix.read(client))
+   assert(data == 'pong!')
+   itworked = true
+else
+   itworked = false
+end
+
+-- Wait for client to terminate. We don't check error here because if
+-- the child already died and the signal handler reaped it, then this
+-- returns a ECHILD error which is fine.
+unix.wait()
+assert(itworked)
+
+-- Now clean up the socket file.
+unix.unlink(unixpath)
+
+SetStatus(200)
+SetHeader('Connection', 'close') -- be lazy and let _Exit() clean up signal handlers
+SetHeader('Content-Type', 'text/html; charset=utf-8')
+Write('<!doctype html>\r\n')
+Write('<title>redbean unix domain sockets example</title>\r\n')
+Write('<h1>\r\n')
+Write('<img style="vertical-align:middle" src="data:image/png;base64,\r\n')
+Write(EncodeBase64(LoadAsset('/redbean.png')))
+Write('">\r\n')
+Write('redbean unix domain sockets example\r\n')
+Write('</h1>\r\n')
+Write([[
+  <p>
+    <strong>It worked!</strong> We successfully sent a ping
+    pong via UNIX local sockets. Please check out the source
+    code to this example inside your redbean at unix-unix.lua.
+  </p>
+]])
+Write('</h1>\r\n')