def flush(self):
"""
May raise exceptions.TcpDisconnect
"""
if hasattr(self.o, "flush"):
try:
self.o.flush()
except (socket.error, IOError) as v:
raise exceptions.TcpDisconnect(str(v))
def safe_read(self, length):
"""
Like .read, but is guaranteed to either return length bytes, or
raise an exception.
"""
result = self.read(length)
if length != -1 and len(result) != length:
if not result:
raise exceptions.TcpDisconnect()
else:
raise exceptions.TcpReadIncomplete(
"Expected %s bytes, got %s" % (length, len(result)))
return result
def read(self, length):
"""
If length is -1, we read until connection closes.
"""
result = b''
start = time.time()
while length == -1 or length > 0:
if length == -1 or length > self.BLOCKSIZE:
rlen = self.BLOCKSIZE
else:
rlen = length
try:
data = self.o.read(rlen)
except SSL.ZeroReturnError:
# TLS connection was shut down cleanly
break
except (SSL.WantWriteError, SSL.WantReadError):
# From the OpenSSL docs:
# If the underlying BIO is non-blocking, SSL_read() will also return when the
# underlying BIO could not satisfy the needs of SSL_read() to continue the
# operation. In this case a call to SSL_get_error with the return value of
# SSL_read() will yield SSL_ERROR_WANT_READ or SSL_ERROR_WANT_WRITE.
# 300 is OpenSSL default timeout
timeout = self.o.gettimeout() or 300
if (time.time() - start) < timeout:
time.sleep(0.1)
continue
else:
raise exceptions.TcpTimeout()
except socket.timeout:
raise exceptions.TcpTimeout()
except OSError as e:
raise exceptions.TcpDisconnect(str(e))
except SSL.SysCallError as e:
if e.args == (-1, 'Unexpected EOF'):
break
raise exceptions.TlsException(str(e))
except SSL.Error as e:
raise exceptions.TlsException(str(e))
self.first_byte_timestamp = self.first_byte_timestamp or time.time(
)
if not data:
break
result += data
if length != -1:
length -= len(data)
self.add_log(result)
return result
def write(self, v):
"""
May raise exceptions.TcpDisconnect
"""
if v:
self.first_byte_timestamp = self.first_byte_timestamp or time.time()
try:
if hasattr(self.o, "sendall"):
self.add_log(v)
return self.o.sendall(v)
else:
r = self.o.write(v)
self.add_log(v[:r])
return r
except (SSL.Error, socket.error) as e:
raise exceptions.TcpDisconnect(str(e))
