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-rw-r--r--paramiko/proxy.py33
1 files changed, 27 insertions, 6 deletions
diff --git a/paramiko/proxy.py b/paramiko/proxy.py
index 218b76e..3f5c8bb 100644
--- a/paramiko/proxy.py
+++ b/paramiko/proxy.py
@@ -20,10 +20,13 @@
L{ProxyCommand}.
"""
+from datetime import datetime
import os
from shlex import split as shlsplit
import signal
from subprocess import Popen, PIPE
+from select import select
+import socket
from paramiko.ssh_exception import ProxyCommandFailure
@@ -48,6 +51,8 @@ class ProxyCommand(object):
"""
self.cmd = shlsplit(command_line)
self.process = Popen(self.cmd, stdin=PIPE, stdout=PIPE, stderr=PIPE)
+ self.timeout = None
+ self.buffer = []
def send(self, content):
"""
@@ -64,7 +69,7 @@ class ProxyCommand(object):
# died and we can't proceed. The best option here is to
# raise an exception informing the user that the informed
# ProxyCommand is not working.
- raise BadProxyCommand(' '.join(self.cmd), e.strerror)
+ raise ProxyCommandFailure(' '.join(self.cmd), e.strerror)
return len(content)
def recv(self, size):
@@ -78,14 +83,30 @@ class ProxyCommand(object):
@rtype: int
"""
try:
- return os.read(self.process.stdout.fileno(), size)
+ start = datetime.now()
+ while len(self.buffer) < size:
+ if self.timeout is not None:
+ elapsed = (datetime.now() - start).microseconds
+ timeout = self.timeout * 1000 * 1000 # to microseconds
+ if elapsed >= timeout:
+ raise socket.timeout()
+ r, w, x = select([self.process.stdout], [], [], 0.0)
+ if r and r[0] == self.process.stdout:
+ b = os.read(self.process.stdout.fileno(), 1)
+ # Store in class-level buffer for persistence across
+ # timeouts; this makes us act more like a real socket
+ # (where timeouts don't actually drop data.)
+ self.buffer.append(b)
+ result = ''.join(self.buffer)
+ self.buffer = []
+ return result
+ except socket.timeout:
+ raise # socket.timeout is a subclass of IOError
except IOError, e:
- raise BadProxyCommand(' '.join(self.cmd), e.strerror)
+ raise ProxyCommandFailure(' '.join(self.cmd), e.strerror)
def close(self):
os.kill(self.process.pid, signal.SIGTERM)
def settimeout(self, timeout):
- # Timeouts are meaningless for this implementation, but are part of the
- # spec, so must be present.
- pass
+ self.timeout = timeout