extern/sshuttle
1
1
Fork 0
mirror of https://github.com/sshuttle/sshuttle.git synced 2025-05-09 10:34:33 +02:00
Code Issues Packages Projects Releases Wiki Activity

dns: trim DNS channel handlers after a response, or after a timeout.

Browse Source 
This avoids memory/socket leaks.
This commit is contained in:
Avery Pennarun 2011-01-26 02:34:12 -08:00
parent 4c5185dc55
commit b570778894
2 changed files with 25 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
client.py
View File

@ -1,4 +1,4 @@
import struct, socket, select, errno, re, signal import struct, socket, select, errno, re, signal, time
import compat.ssubprocess as ssubprocess import compat.ssubprocess as ssubprocess
import helpers, ssnet, ssh, ssyslog import helpers, ssnet, ssh, ssyslog
from ssnet import SockWrapper, Handler, Proxy, Mux, MuxWrapper from ssnet import SockWrapper, Handler, Proxy, Mux, MuxWrapper
@ -293,22 +293,27 @@ def _main(listener, fw, ssh_cmd, remotename, python, latency_control,
handlers.append(Proxy(SockWrapper(sock, sock), outwrap)) handlers.append(Proxy(SockWrapper(sock, sock), outwrap))
handlers.append(Handler([listener], onaccept)) handlers.append(Handler([listener], onaccept))
dnspeers = {} dnsreqs = {}
def dns_done(chan, data): def dns_done(chan, data):
peer = dnspeers.get(chan) peer,timeout = dnsreqs.get(chan)
debug1('dns_done: channel=%r peer=%r\n' % (chan, peer)) debug3('dns_done: channel=%r peer=%r\n' % (chan, peer))
if peer: if peer:
del dnspeers[chan] del dnsreqs[chan]
debug1('doing sendto %r\n' % (peer,)) debug3('doing sendto %r\n' % (peer,))
dnslistener.sendto(data, peer) dnslistener.sendto(data, peer)
def ondns(): def ondns():
pkt,peer = dnslistener.recvfrom(4096) pkt,peer = dnslistener.recvfrom(4096)
now = time.time()
if pkt: if pkt:
debug1('Got DNS request from %r: %d bytes\n' % (peer, len(pkt))) debug1('DNS request from %r: %d bytes\n' % (peer, len(pkt)))
chan = mux.next_channel() chan = mux.next_channel()
dnspeers[chan] = peer dnsreqs[chan] = peer,now+30
mux.send(chan, ssnet.CMD_DNS_REQ, pkt) mux.send(chan, ssnet.CMD_DNS_REQ, pkt)
mux.channels[chan] = lambda cmd,data: dns_done(chan,data) mux.channels[chan] = lambda cmd,data: dns_done(chan,data)
for chan,(peer,timeout) in dnsreqs.items():
if timeout < now:
del dnsreqs[chan]
debug3('Remaining DNS requests: %d\n' % len(dnsreqs))
if dnslistener: if dnslistener:
handlers.append(Handler([dnslistener], ondns)) handlers.append(Handler([dnslistener], ondns))

15
server.py
View File

@ -1,4 +1,4 @@
import re, struct, socket, select, traceback import re, struct, socket, select, traceback, time
if not globals().get('skip_imports'): if not globals().get('skip_imports'):
import ssnet, helpers, hostwatch import ssnet, helpers, hostwatch
import compat.ssubprocess as ssubprocess import compat.ssubprocess as ssubprocess
@ -111,6 +111,7 @@ class DnsProxy(Handler):
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
Handler.__init__(self, [sock]) Handler.__init__(self, [sock])
self.sock = sock self.sock = sock
self.timeout = time.time()+30
self.mux = mux self.mux = mux
self.chan = chan self.chan = chan
self.sock.setsockopt(socket.SOL_IP, socket.IP_TTL, 42) self.sock.setsockopt(socket.SOL_IP, socket.IP_TTL, 42)
@ -119,8 +120,9 @@ class DnsProxy(Handler):
def callback(self): def callback(self):
data = self.sock.recv(4096) data = self.sock.recv(4096)
debug2('dns response: %d bytes\n' % len(data)) debug2('DNS response: %d bytes\n' % len(data))
self.mux.send(self.chan, ssnet.CMD_DNS_RESPONSE, data) self.mux.send(self.chan, ssnet.CMD_DNS_RESPONSE, data)
self.ok = False
def main(): def main():
@ -184,7 +186,7 @@ def main():
dnshandlers = {} dnshandlers = {}
def dns_req(channel, data): def dns_req(channel, data):
debug1('got dns request!\n') debug2('Incoming DNS request.\n')
h = DnsProxy(mux, channel, data) h = DnsProxy(mux, channel, data)
handlers.append(h) handlers.append(h)
dnshandlers[channel] = h dnshandlers[channel] = h
@ -201,3 +203,10 @@ def main():
if latency_control: if latency_control:
mux.check_fullness() mux.check_fullness()
mux.callback() mux.callback()
if dnshandlers:
now = time.time()
for channel,h in dnshandlers.items():
if h.timeout < now or not h.ok:
del dnshandlers[channel]
h.ok = False