def send_packet(packet, user, to_server):
"""Takes packet, user object and whether to send to server (as though from user) or vice versa.
Simulates that kind of packet having been recived and passes it on as normal,
ie. a packet still goes through the whole list of plugins.
"""
packets = handle_packet(packet, user, to_server)
try:
out_bytestr = "".join([pack(packet, to_server) for packet in packets])
except: # Undefined exception inherited from packet_decoder
logging.exception(
"Bad packet object while packing generated packet %s %s: %s", "from" if to_server else "to", user, packet
)
raise # Will be caught as a failure of the plugin sending it.
fd = user.srv_sock if to_server else user.user_sock
write_buf = send_buffers.get(fd, "")
write_buf += out_bytestr
send_buffers[fd] = write_buf
def main():
global listener, ticks
listener = socket()
listener.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
listener.bind(LISTEN_ADDR)
listener.listen(128)
listener.setblocking(0)
logging.basicConfig(filename=LOG_FILE, level=LOG_LEVEL, format=LOG_FORMAT)
if DEBUG:
debug_handler = logging.StreamHandler() # defaults to stderr
debug_handler.setFormatter(logging.Formatter(LOG_FORMAT))
debug_handler.setLevel(logging.DEBUG)
logging.root.addHandler(debug_handler)
logging.info("Starting up")
if PASSTHROUGH:
passthrough_log = open(PASSTHROUGH_LOG_FILE, "w")
import helpers # Hax before import does important hax
helpers.active_users = active_users
helpers.send_packet = send_packet
from plugins import plugins as _plugins # Lazy import prevents circular references
global plugins
plugins = _plugins
for plugin in plugins[:]: # Note that x[:] is a copy of x
try:
logging.debug("Loading plugin: %s", plugin)
if hasattr(plugin, "on_start"):
plugin.on_start()
except:
logging.exception("Error initialising plugin %s", plugin)
plugins.remove(plugin)
if not DEBUG:
print "proxy: Daemonising..."
daemonise()
sys.stdout.close()
sys.stderr.close()
logging.debug("Started up")
def add_tick(sig, frame):
global ticks
ticks += 1
signal.signal(signal.SIGALRM, add_tick)
signal.setitimer(signal.ITIMER_REAL, TICK_INTERVAL, TICK_INTERVAL)
try:
while 1:
while ticks:
handle_tick()
ticks -= 1
try:
r, w, x = select(conn_map.keys() + [listener], send_buffers.keys(), [])
except select_error, ex:
ex_errno, ex_msg = ex.args
if ex_errno == errno.EINTR:
continue # This lets us handle any tick that may have been queued and retry
raise
dead = [] # Keeps track of fds in r, w that get dropped, so we know when not to bother.
for fd in w:
if fd in dead:
logging.debug("fd already down - skipping")
continue
buf = send_buffers[fd]
try:
n = fd.send(buf[:MAX_SEND])
except socket_error, ex:
if ex.errno == errno.EINTR:
n = 0
elif ex.errno in (errno.ECONNRESET, errno.EPIPE, errno.ENETDOWN, errno.ENETUNREACH, errno.ENOBUFS):
# These are all socket failure conditions, drop the connection
user = user_map[fd]
if (
ex.errno == errno.ECONNRESET and fd in usersocks
): # User CONNRESET is ok, means user closed program or lost conn. Server CONNRESET is NOT.
logging.info("Connection from %s closed by connection reset", user)
else:
logging.warning(
"Dropping connection for %s due to send error to %s",
user,
"user" if fd in user_socks else "server",
exc_info=1,
)
dead += [fd, conn_map[fd]]
drop_connection(user)
continue
else:
raise
assert n <= len(buf)
if n < len(buf):
send_buffers[fd] = buf[n:]
else:
del send_buffers[fd]
for fd in r:
if fd in dead:
logging.debug("fd already down - skipping")
continue
if fd is listener:
new_connection()
continue
buf = read_buffers[fd]
to_server = fd in user_socks
user = user_map[fd]
logging.debug("Buffer before read: length %d", len(buf))
try:
read = fd.recv(MAX_RECV)
except socket_error, ex:
if ex.errno == errno.EINTR:
continue
if ex.errno in (errno.ECONNRESET, errno.ETIMEDOUT, errno.ENOBUFS, errno.ENOMEM):
# These are all socket failure conditions, drop the connection
logging.warning(
"Dropping connection for %s due to recv error from %s",
user,
"user" if to_server else "server",
exc_info=1,
)
dead += [fd, conn_map[fd]]
drop_connection(user)
continue
if not read:
# Empty read means EOF
if to_server:
logging.info("Connection from %s closed", user)
else:
logging.info("Server connection for %s closed", user)
dead += [fd, conn_map[fd]]
drop_connection(user)
continue
# logging.debug("Read %s server for %s: %s", "to" if to_server else "from", user, repr(read))
buf += read
logging.debug("Buffer after read: length %d", len(buf))
# Decode as many packets as we can
while 1:
if PASSTHROUGH:
if not buf:
break
out_bytestr = buf
logging.info("Passing through %s", repr(buf))
passthrough_log.write(buf)
passthrough_log.flush()
buf = ""
else:
try:
packet, buf = unpack(buf, to_server)
except: # Undefined exception inherited from packet_decoder
logging.exception(
"Bad packet %s %s:\n%s", "from" if to_server else "to", user, hexdump(buf)
)
logging.warning(
"Dropping connection for %s due to bad packet from %s",
user,
"user" if to_server else "server",
)
dead += [fd, conn_map[fd]]
drop_connection(user)
break
if packet is None:
# Couldn't decode, need more read first - we're done here.
break
# logging.debug("%s server for %s: %s", "to" if to_server else "from", user, packet)
packets = handle_packet(packet, user, to_server)
packed = []
for packet in packets:
try:
packed.append(pack(packet, to_server))
except: # Undefined exception inherited from packet_decoder
logging.warning(
"Bad packet object while packing packet %s %s: %s",
"from" if to_server else "to",
user,
packet,
exc_info=1,
)
out_bytestr = "".join(packed)
# Append resulting bytestr to write buffer, to be sent later.
send_fd = conn_map[fd]
write_buf = send_buffers.get(send_fd, "")
write_buf += out_bytestr
send_buffers[send_fd] = write_buf
if fd not in dead:
logging.debug("Buffer after decode: length %d", len(buf))
read_buffers[fd] = buf
