update README

- Adds the --log-sensitive option.
- Tag with [SENSITIVE] in the logs.
- Avoid formatting within logging calls.

README.md

@@ -5,12 +5,12 @@ tunnelmon -- Monitor and manage autoSSH tunnels
 
 `tunnelmon` [-h]
 
-`tunnelmon` [-c] [-n] [-u] [-l LEVEL] [-g FILE]
+`tunnelmon` [-c] [-n] [-u] [-l LEVEL] [-g FILE] [-s]
 
 
 ## DESCRIPTION
 
-`tunnelmon` is an autossh tunnel monitor. It gives a user interface to monitor existing SSH tunnel, and tunnels managed with autossh. 
+`tunnelmon` is an autossh tunnel monitor. It gives a user interface to monitor existing SSH tunnel, and tunnels managed with autossh.
 
 It can print the current state of your tunnels or display them in an interactive text-based interface.
 
@@ -22,8 +22,10 @@ It can print the current state of your tunnels or display them in an interactive
 ## INSTALLATION
 
 `tunnelmon` targets Linux operating systems, and depends on:
-* `openssh-client`
+* `openssh-client`,
-* `python` version 3.8 at least.
+* `python` version 3.8 at least, you may also need to install the following python modules (for example via `pip`, but you may use any other package management system going along with your installation):
+  * `psutils`
+  * `curses`
 
 You may also want to install the recommend packages:
 * `autossh`
@@ -53,6 +55,9 @@ Called without option,`tunnelmon` will print the current state of the autossh tu
   Log messages are written to the given FILE. Useful to debug the interactive interface.
   If not set, asking for the curses interface automatically set logging to the "tunnelmon.log" file.
 
+* `-s`, `--log-sensitive`:
+  Allow sensitive information (hostnames, IPs, PIDs, etc.) into the logs.
+
 
 ## INTERACTIVE INTERFACE
 
@@ -62,7 +67,7 @@ Keyboard commands:
 * `R`: Reload the selected autossh instance (i.e. send a `SIGUSR1`, which is interpreted as a reload command by autossh).
 * `C`: Close the selected tunnel (i.e. send a `SIGTERM`).
 * `N`: Show the network connections related to each tunnel instances.
-* `Q`: Quit tunnelmon.
+* `Q`: Quit Tunnelmon.
 
 
 ## DISPLAY

tunnelmon.py

@@ -36,6 +36,7 @@ import re
 import collections
 import itertools
 
+log_sensitive = False
 
 class Tunnel:
     def __init__(self, ssh_pid=None, in_port=None, via_host=None, target_host=None, out_port=None, forward=None):
@@ -162,16 +163,22 @@ class TunnelsParser:
         return self.tunnels[pid]
 
     def parse(self, cmd):
-        cmdline = " ".join(cmd)
+        try:
+            cmdline = " ".join(cmd)
+        except TypeError:
+            cmdline = cmd
 
-        logging.debug('autossh cmd line: %s', cmdline)
+        if log_sensitive:
-        logging.debug('forwarding regexp: %s', self.re_forwarding)
+            logging.debug("[SENSITIVE] autossh cmd line: %s", cmdline)
+        logging.debug("forwarding regexp: %s" % self.re_forwarding)
         match = self.re_forwarding.findall(cmdline)
-        logging.debug(match)
+        if log_sensitive:
+            logging.debug("[SENSITIVE] match: %s", match)
         if match:
             assert len(match) == 1
             forward, in_port, target_host, out_port = match[0]
-            logging.debug("matches: %s", match)
+            if log_sensitive:
+                logging.debug("[SENSITIVE] matches: %s", match)
         else:
             raise ValueError("is not a ssh tunnel")
 
@@ -181,7 +188,8 @@ class TunnelsParser:
         # FIXME this is an ugly hack
         i = 1
         while i < len(cmd):
-            logging.debug("ici: %i %s", i, cmd[i])
+            if log_sensitive:
+                logging.debug("[SENSITIVE] here: %i %s", i, cmd[i])
             if cmd[i][0] == '-':
                 if cmd[i][1] in '46AaCfGgKkMNnqsTtVvXxYy':
                     # flag without argument
@@ -211,12 +219,14 @@ class TunnelsParser:
                 pass
             else:
                 if process['name'] == 'ssh':
-                    logging.debug(process)
+                    if log_sensitive:
+                        logging.debug("[SENSITIVE] process: %s ", process)
                     try:
                         in_port, via_host, target_host, out_port, forward = self.parse(cmd)
                     except ValueError:
                         continue
-                    logging.debug("%s %s %s %s %s", in_port, via_host, target_host, out_port, forward)
+                    if log_sensitive:
+                        logging.debug("[SENSITIVE] parsed: %s %s %s %s %s", in_port, via_host, target_host, out_port, forward)
 
                     # Check if this ssh tunnel is managed by autossh.
                     parent = psutil.Process(process['ppid'])
@@ -230,17 +240,20 @@ class TunnelsParser:
                         self.tunnels[pid] = RawTunnel(pid, in_port, via_host, target_host, out_port, forward)
 
                     for c in process['connections']:
-                        logging.debug(c)
+                        if log_sensitive:
+                            logging.debug("[SENSITIVE] connection: %s", c)
                         laddr, lport = c.laddr
                         if c.raddr:
                             raddr, rport = c.raddr
                         else:
                             raddr, rport = (None, None)
                         connection = Connection(laddr, lport, raddr, rport, c.status, c.family)
-                        logging.debug(connection)
+                        if log_sensitive:
+                            logging.debug("[SENSITIVE] connection: %s", connection)
                         self.tunnels[pid].connections.append(connection)
 
-        logging.debug(self.tunnels)
+        if log_sensitive:
+            logging.debug("[SENSITIVE] %s", self.tunnels)
 
     def __repr__(self):
         reps = [self.header]
@@ -260,7 +273,7 @@ class CursesMonitor:
     def __init__(self, scr):
         # hide cursor
         curses.curs_set(0)
-        
+
         # curses screen
         self.scr = scr
 
@@ -341,14 +354,14 @@ class CursesMonitor:
 
     def do_Q(self):
         """Quit"""
-        logging.debug("Waited: %s" % self.log_ticks)
+        logging.debug("Waited: %s", self.log_ticks)
         self.log_ticks = ""
         logging.debug("Key pushed: Q")
         return False
 
     def do_R(self):
         """Reload autossh tunnel"""
-        logging.debug("Waited: %s" % self.log_ticks)
+        logging.debug("Waited: %s", self.log_ticks)
         self.log_ticks = ""
         logging.debug("Key pushed: R")
         # if a pid is selected
@@ -356,7 +369,8 @@ class CursesMonitor:
             # send the SIGUSR1 signal
             if type(self.tp.get_tunnel(self.cur_line)) == AutoTunnel:
                 # autossh performs a reload of existing tunnels that it manages
-                logging.debug("SIGUSR1 on PID: %i" % self.cur_pid)
+                if log_sensitive:
+                    logging.debug("[SENSITIVE] SIGUSR1 on PID: %i", self.cur_pid)
                 os.kill(self.cur_pid, signal.SIGUSR1)
             else:
                 logging.debug("Cannot reload a RAW tunnel")
@@ -364,7 +378,7 @@ class CursesMonitor:
 
     def do_C(self):
         """Close tunnel"""
-        logging.debug("Waited: %s" % self.log_ticks)
+        logging.debug("Waited: %s", self.log_ticks)
         self.log_ticks = ""
         logging.debug("Key pushed: C")
         if self.cur_pid != -1:
@@ -374,17 +388,21 @@ class CursesMonitor:
 
             tunnel = self.tp.get_tunnel(self.cur_line)
             if type(tunnel) == AutoTunnel:
-                logging.debug("SIGKILL on autossh PID: %i" % self.cur_pid)
+                if log_sensitive:
+                    logging.debug("[SENSITIVE] SIGKILL on autossh PID: %i", self.cur_pid)
                 try:
                     os.kill(self.cur_pid, signal.SIGKILL)
                 except OSError:
-                    logging.error("No such process: %i" % self.cur_pid)
+                    if log_sensitive:
+                        logging.error("[SENSITIVE] No such process: %i", self.cur_pid)
 
-            logging.debug("SIGKILL on ssh PID: %i" % tunnel.ssh_pid)
+            if log_sensitive:
+                logging.debug("[SENSITIVE] SIGKILL on ssh PID: %i", tunnel.ssh_pid)
             try:
                 os.kill(tunnel.ssh_pid, signal.SIGKILL)
             except OSError:
-                logging.error("No such process: %i" % tunnel.ssh_pid)
+                if log_sensitive:
+                    logging.error("[SENSITIVE] No such process: %i", tunnel.ssh_pid)
         self.cur_line -= 1
         self.cur_pid = -1
         # FIXME update cur_pid or get rid of it everywhere
@@ -392,7 +410,7 @@ class CursesMonitor:
 
     def do_N(self):
         """Show connections"""
-        logging.debug("Waited: %s" % self.log_ticks)
+        logging.debug("Waited: %s", self.log_ticks)
         self.log_ticks = ""
         logging.debug("Key pushed: N")
         self.show_connections = not self.show_connections
@@ -400,7 +418,7 @@ class CursesMonitor:
 
     def do_258(self):
         """Move down"""
-        logging.debug("Waited: %s" % self.log_ticks)
+        logging.debug("Waited: %s", self.log_ticks)
         self.log_ticks = ""
         logging.debug("Key pushed: down")
         # if not the end of the list
@@ -415,7 +433,7 @@ class CursesMonitor:
 
     def do_259(self):
         """Move up"""
-        logging.debug("Waited: %s" % self.log_ticks)
+        logging.debug("Waited: %s", self.log_ticks)
         self.log_ticks = ""
         logging.debug("Key pushed: up")
         if self.cur_line > -1:
@@ -454,10 +472,11 @@ class CursesMonitor:
 
                 state = "%s" % self.tp
                 if state != self.last_state:
-                    logging.debug("Waited: %s" % self.log_ticks)
+                    logging.debug("Waited: %s", self.log_ticks)
                     self.log_ticks = ""
-                    logging.debug("----- Time of screen update: %s -----" % time.time())
+                    logging.debug("----- Time of screen update: %s -----", time.time())
-                    logging.debug("State of tunnels:\n%s" % self.tp)
+                    if log_sensitive:
+                        logging.debug("[SENSITIVE] State of tunnels:\n%s", self.tp)
                     self.last_state = state
                 else:
                     self.log_ticks += "."
@@ -476,12 +495,12 @@ class CursesMonitor:
             # Call the do_* handler.
             fch = "do_%s" % ch.capitalize()
             fkc = "do_%i" % kc
-            logging.debug("key func: %s / %s" % (fch, fkc))
+            logging.debug("key func: %s / %s", fch, fkc)
             if fch in dir(self):
                 notquit = eval("self."+fch+"()")
             elif fkc in dir(self):
                 notquit = eval("self."+fkc+"()")
-            logging.debug("notquit = %s" % notquit)
+            logging.debug("notquit = %s", notquit)
 
             # update the display
             self.display()
@@ -492,15 +511,15 @@ class CursesMonitor:
         # end of the loop
 
     def format(self):
-        """Prepare formating strings to pad with spaces up to the tolumn header width."""
+        """Prepare formating strings to pad with spaces up to the column header width."""
         reps = [self.tp.tunnels[t].repr_tunnel() for t in self.tp.tunnels]
         tuns = [t.split() for t in reps]
         tuns.append(self.header)
         cols = itertools.zip_longest(*tuns, fillvalue='')
         widths = [max(len(s) for s in col) for col in cols]
-        logging.debug(widths)
+        logging.debug("Columns widths: %s", widths)
         fmt = ['{{: <{}}}'.format(w) for w in widths]
-        logging.debug(fmt)
+        logging.debug("Columns formats: %s", fmt)
         return fmt
 
     def display(self):
@@ -721,6 +740,10 @@ if __name__ == "__main__":
                       help="Log to this file, default to standard output. \
             If you use the curses interface, you may want to set this to actually see logs.")
 
+    parser.add_option("-s", "--log-sensitive",
+                      action="store_true", default=False,
+                      help="Do log sensitive informations (like hostnames, IPs and PIDs).")
+
     parser.add_option('-f', '--config-file', default=None, metavar='FILE',
                       help="Use this configuration file (default: '~/.tunnelmon.conf')")
 
@@ -732,7 +755,7 @@ if __name__ == "__main__":
         logfile = asked_for.log_file
         logging.basicConfig(filename=logfile, level=LOG_LEVELS[asked_for.log_level])
         logging.debug(logmsg)
-        logging.debug("Log in %s" % logfile)
+        logging.debug("Log in %s", logfile)
     else:
         if asked_for.curses:
             logging.warning("It's a bad idea to log to stdout while in the curses interface.")
@@ -740,7 +763,11 @@ if __name__ == "__main__":
         logging.debug(logmsg)
         logging.debug("Log to stdout")
 
-    logging.debug("Asked for: %s", asked_for)
+    logging.debug("Asked for: %s" % asked_for)
+
+    if asked_for.log_sensitive:
+        logging.debug("Asked for logging sensitive information.")
+        log_sensitive = True
 
     # unfortunately, asked_for class has no __len__ method in python 2.4.3 (bug?)
     # if len(asked_for) > 1:
@@ -810,7 +837,8 @@ if __name__ == "__main__":
         tp = TunnelsParser()
         tp.update()
         # do not call update() but only get connections
-        logging.debug("UID: %i.", os.geteuid())
+        if log_sensitive:
+            logging.debug("[SENSITIVE] UID: %i", os.geteuid())
         # if os.geteuid() == 0:
         for t in tp.tunnels:
             for c in tp.tunnels[t].connections: