Explain the prefix stuff a bit more

[saartuer.git] / tuerd

diff --git a/tuerd b/tuerd
index a283f26d9221c47feae5b31758b7dc0181cb84ca..f03d5dbc69d17d382a1757b8b2fc44851fe668f1 100755 (executable)
--- a/tuerd
+++ b/tuerd
@@ -1,15 +1,21 @@
 #!/usr/bin/python3
-import time, socket, os, stat
+import time, socket, os, stat, atexit, errno, struct, pwd
+from libtuer import log
 from datetime import datetime
 import RPi.GPIO as GPIO
+SO_PEERCRED = 17 # DO - NOT - TOUCH
 GPIO.setmode(GPIO.BOARD)
+atexit.register(GPIO.cleanup)
 
-# ******** definitions *********
-# logging function
-# TODO: loglevel, log like a real daemon
-def log (what):
-       print (datetime.now(),what)
+#tmp
+def recv_timeout(conn, size, time):
+       (r, w, x) = select.select([conn], [], [], time)
+       if len(r):
+               assert r[0] == conn
+               return conn.recv(size)
+       return None
 
+# ******** definitions *********
 # send to client for information but don't care if it arrives
 def waynesend (conn, what):
        try:
@@ -23,6 +29,15 @@ def doNothing (conn):
        waynesend(conn,b"0")
        pass
 
+# delete a file, don't care if it did not exist in the first place
+def forcerm(name):
+       try:
+               os.unlink (name)
+       except OSError as e:
+               # only ignore error if it was "file didn't exist"
+               if e.errno != errno.ENOENT:
+                       raise
+
 # commands: on a pin do a series of timed on/off switches
 class Pinoutput:
        # name is for logging and also used for mapping command names to instances of this class
@@ -37,9 +52,10 @@ class Pinoutput:
        def __call__ (self, conn):
                for (value,delay) in self.todo:
                        GPIO.output(self.pin, value)
-                       log ("%s: Pin %d set to %s." % (self.name,self.pin,str(value)))
+                       # log ("%s: Pin %d set to %s." % (self.name,self.pin,str(value)))
                        time.sleep(delay)
                # notify success
+               log 
                waynesend(conn,b"1")
 
 # ******** configuration *********
@@ -60,10 +76,7 @@ for pin in pinlist:
 # create socket
 sock = socket.socket (socket.AF_UNIX, socket.SOCK_STREAM)
 # delete old socket file and don't bitch around if it's not there
-try:
-       os.unlink (socketname)
-except OSError:
-       pass
+forcerm(socketname)
 # bind socket to file name
 sock.bind (socketname)
 # allow only users in the tuergroup to write to the socket
@@ -72,22 +85,31 @@ os.chmod (socketname, stat.S_IRUSR | stat.S_IWUSR | stat.S_IRGRP | stat.S_IWGRP)
 # listen to the people, but not too many at once
 sock.listen(1)
 
+# shutdown handling
+def shutdown():
+       log("Shutting down")
+       sock.close()
+       forcerm(socketname)
+atexit.register(shutdown)
+
 # main loop
 # FIXME: DoS by opening socket but not sending data, because this loop is single threaded; maybe settimeout helps a bit.
 while True:
        # accept connections
        conn, addr = sock.accept()
-       # TODO: use addr to determine the client for logging
-       # get some data from the client (enough to hold any valid command)
-       data = conn.recv (32)
-       # log the command
-       log("received command: %s" % str(data))
-       # lookup the command, if it's not in the dict, use the doNothing function instead
-       # and execute the looked up command or doNothing with the connection, so it can respond to the client
-       pindict.get(data,doNothing)(conn)
-       # close connection cleanly
-       conn.close()
-
-# FIXME will this be executed after receiving a terminating signal?
-GPIO.cleanup()
+       try:
+               # get peer information
+               (pid, uid, gid) = (struct.unpack('3i', conn.getsockopt(socket.SOL_SOCKET, SO_PEERCRED, struct.calcsize('3i'))))
+               # get some data from the client (enough to hold any valid command)
+               data = conn.recv (32)
+               # log the command
+               log("received command from %s (uid %d): %s" % (pwd.getpwuid(uid).pw_name,uid, str(data)))
+               # lookup the command, if it's not in the dict, use the doNothing function instead
+               # and execute the looked up command or doNothing with the connection, so it can respond to the client
+               pindict.get(data,doNothing)(conn)
+               log("done")
+               # close connection cleanly
+               conn.close()
+       except Exception as e:
+               log("Something went wrong: %s\n...continuing." % str(e))