massive simplification of command shortcuts

[saartuer.git] / tuerd

diff --git a/tuerd b/tuerd
index 7cc15d6cf0ce5c98f44ca356ff0ca00398005624..f03d5dbc69d17d382a1757b8b2fc44851fe668f1 100755 (executable)
--- a/tuerd
+++ b/tuerd
@@ -1,73 +1,115 @@
 #!/usr/bin/python3
 #!/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
 from datetime import datetime
 import RPi.GPIO as GPIO

+SO_PEERCRED = 17 # DO - NOT - TOUCH

 GPIO.setmode(GPIO.BOARD)
 GPIO.setmode(GPIO.BOARD)

-
-def log (what):
-       print (datetime.now(),what)
-
+atexit.register(GPIO.cleanup)
+
+#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:
                conn.send(what)
        except:
                log("Couldn't send %s" % str(what))
 
 def waynesend (conn, what):
        try:
                conn.send(what)
        except:
                log("Couldn't send %s" % str(what))
 

+# for command not found: do nothing with the pins and send a "0" to the client
+def doNothing (conn):
+       log ("doing nothing")
+       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:
 class Pinoutput:

-       # actionsanddelays is a list of pairs: (bool to send, delay in seconds to wait afterwards)
+       # name is for logging and also used for mapping command names to instances of this class
+       # actionsanddelays is a list of pairs: (bool to set on pin, delay in seconds to wait afterwards)

        def __init__ (self, name, pinnumber, actionsanddelays):
                self.name = name
                self.pin = pinnumber
                self.todo = actionsanddelays
                GPIO.setup(pinnumber, GPIO.OUT)
                log ("Pin %d set to be an output pin for %s." % (pinnumber,name))
        def __init__ (self, name, pinnumber, actionsanddelays):
                self.name = name
                self.pin = pinnumber
                self.todo = actionsanddelays
                GPIO.setup(pinnumber, GPIO.OUT)
                log ("Pin %d set to be an output pin for %s." % (pinnumber,name))

-       
+       # actually send the signal to the pins

        def __call__ (self, conn):
                for (value,delay) in self.todo:
                        GPIO.output(self.pin, value)
        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)
                        time.sleep(delay)

+               # notify success
+               log 

                waynesend(conn,b"1")
 
                waynesend(conn,b"1")
 

-tuergroupid = 1005
+# ******** configuration *********

 
 

+tuergroupid = 1005
+socketname = "/run/tuer.sock"

 pinlist = [Pinoutput("open", 12, [(True, 0.3), (False, 5.0)]),
        Pinoutput("close", 16, [(True, 0.3), (False, 5.0)]),
 pinlist = [Pinoutput("open", 12, [(True, 0.3), (False, 5.0)]),
        Pinoutput("close", 16, [(True, 0.3), (False, 5.0)]),

-       Pinoutput("buzz", 22, [(True, 2.0), (False, 5.0)])]
-
-socketname = "/run/tuer.sock"
+       Pinoutput("buzz", 22, [(True, 2.0), (False, 0.1)])]

 
 
 
 

-def doNothing (conn):
-       log ("doing nothing")
-       waynesend(conn,b"0")
-       pass
+# ******** main *********
+# convert list of pin objects to dictionary for command lookup
+pindict = {}
+for pin in pinlist:
+       pindict[pin.name.encode()] = pin

 
 

+# create socket

 sock = socket.socket (socket.AF_UNIX, socket.SOCK_STREAM)
 sock = socket.socket (socket.AF_UNIX, socket.SOCK_STREAM)

-
-try:
-       os.unlink (socketname)
-except OSError:
-       pass
-
+# delete old socket file and don't bitch around if it's not there
+forcerm(socketname)
+# bind socket to file name

 sock.bind (socketname)
 sock.bind (socketname)

-
+# allow only users in the tuergroup to write to the socket

 os.chown (socketname, 0, tuergroupid)
 os.chmod (socketname, stat.S_IRUSR | stat.S_IWUSR | stat.S_IRGRP | stat.S_IWGRP)
 os.chown (socketname, 0, tuergroupid)
 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)
 
 sock.listen(1)
 

-pindict = {}
-for pin in pinlist:
-       pindict[pin.name.encode()] = pin
+# 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:
 while True:

+       # accept connections

        conn, addr = sock.accept()
        conn, addr = sock.accept()

-       data = conn.recv (128)
-       log("received command: %s" % str(data))
-       pindict.get(data,doNothing)(conn)
-       conn.close()
-
-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))