# A transport class. With two implementations.
# One for socket and one for shared memory.
#
+import logging
from cffi import FFI
import cffi
+logger = logging.getLogger('vpp_papi.transport')
+logger.addHandler(logging.NullHandler())
+
ffi = FFI()
ffi.cdef("""
typedef void (*vac_callback_t)(unsigned char * data, int len);
void vac_rx_suspend (void);
void vac_rx_resume (void);
void vac_set_error_handler(vac_error_callback_t);
- """)
+void vac_mem_init (size_t size);
+""")
vpp_object = None
-# Barfs on failure, no need to check success.
-vpp_api = ffi.dlopen('libvppapiclient.so')
+# allow file to be imported so it can be mocked in tests.
+# If the shared library fails, VppTransport cannot be initialized.
+try:
+ vpp_api = ffi.dlopen('libvppapiclient.so')
+except OSError:
+ vpp_api = None
@ffi.callback("void(unsigned char *, int)")
vpp_object.logger.warning("VPP API client:: %s", ffi.string(msg, msg_len))
+class VppTransportShmemIOError(IOError):
+ """ exception communicating with vpp over shared memory """
+
+ def __init__(self, rv, descr):
+ self.rv = rv
+ self.desc = descr
+
+ super(VppTransportShmemIOError, self).__init__(rv, descr)
+
+
class VppTransport:
+ VppTransportShmemIOError = VppTransportShmemIOError
+
def __init__(self, parent, read_timeout, server_address):
self.connected = False
self.read_timeout = read_timeout
global vpp_object
vpp_object = parent
+ vpp_api.vac_mem_init(0)
+
# Register error handler
vpp_api.vac_set_error_handler(vac_error_handler)
self.connected = True
if not pfx:
pfx = ffi.NULL
- return vpp_api.vac_connect(name, pfx, msg_handler, rx_qlen)
+ return vpp_api.vac_connect(name.encode('ascii'), pfx, msg_handler, rx_qlen)
def disconnect(self):
self.connected = False
def resume(self):
vpp_api.vac_rx_resume()
- def get_callback(self, async):
- return vac_callback_sync if not async else vac_callback_async
+ def get_callback(self, do_async):
+ return vac_callback_sync if not do_async else vac_callback_async
def get_msg_index(self, name):
- return vpp_api.vac_get_msg_index(name)
+ return vpp_api.vac_get_msg_index(name.encode('ascii'))
def msg_table_max_index(self):
return vpp_api.vac_msg_table_max_index()
def _write_new_cffi(self, buf):
"""Send a binary-packed message to VPP."""
if not self.connected:
- raise IOError(1, 'Not connected')
+ raise VppTransportShmemIOError(1, 'Not connected')
return vpp_api.vac_write(ffi.from_buffer(buf), len(buf))
def _write_legacy_cffi(self, buf):
"""Send a binary-packed message to VPP."""
if not self.connected:
- raise IOError(1, 'Not connected')
+ raise VppTransportShmemIOError(1, 'Not connected')
return vpp_api.vac_write(bytes(buf), len(buf))
- def read(self):
+ def read(self, timeout=None):
if not self.connected:
- raise IOError(1, 'Not connected')
+ raise VppTransportShmemIOError(1, 'Not connected')
+ if timeout is None:
+ timeout = self.read_timeout
mem = ffi.new("char **")
size = ffi.new("int *")
- rv = vpp_api.vac_read(mem, size, self.read_timeout)
+ rv = vpp_api.vac_read(mem, size, timeout)
if rv:
- raise IOError(rv, 'vac_read failed')
+ strerror = 'vac_read failed. It is likely that VPP died.'
+ raise VppTransportShmemIOError(rv, strerror)
msg = bytes(ffi.buffer(mem[0], size[0]))
vpp_api.vac_free(mem[0])
return msg