2 # A transport class. With two implementations.
3 # One for socket and one for shared memory.
11 typedef void (*vac_callback_t)(unsigned char * data, int len);
12 typedef void (*vac_error_callback_t)(void *, unsigned char *, int);
13 int vac_connect(char * name, char * chroot_prefix, vac_callback_t cb,
15 int vac_disconnect(void);
16 int vac_read(char **data, int *l, unsigned short timeout);
17 int vac_write(char *data, int len);
18 void vac_free(void * msg);
20 int vac_get_msg_index(unsigned char * name);
21 int vac_msg_table_size(void);
22 int vac_msg_table_max_index(void);
24 void vac_rx_suspend (void);
25 void vac_rx_resume (void);
26 void vac_set_error_handler(vac_error_callback_t);
31 # Barfs on failure, no need to check success.
32 vpp_api = ffi.dlopen('libvppapiclient.so')
35 @ffi.callback("void(unsigned char *, int)")
36 def vac_callback_sync(data, len):
37 vpp_object.msg_handler_sync(ffi.buffer(data, len))
40 @ffi.callback("void(unsigned char *, int)")
41 def vac_callback_async(data, len):
42 vpp_object.msg_handler_async(ffi.buffer(data, len))
45 @ffi.callback("void(void *, unsigned char *, int)")
46 def vac_error_handler(arg, msg, msg_len):
47 vpp_object.logger.warning("VPP API client:: %s", ffi.string(msg, msg_len))
50 class VppTransportShmemIOError(IOError):
51 """ exception communicating with vpp over shared memory """
53 def __init__(self, rv, descr):
57 super(VppTransportShmemIOError, self).__init__(rv, descr)
60 class VppTransport(object):
61 VppTransportShmemIOError = VppTransportShmemIOError
63 def __init__(self, parent, read_timeout, server_address):
64 self.connected = False
65 self.read_timeout = read_timeout
70 # Register error handler
71 vpp_api.vac_set_error_handler(vac_error_handler)
74 # from_buffer supported from 1.8.0
75 (major, minor, patch) = [int(s) for s in
76 cffi.__version__.split('.', 3)]
77 if major >= 1 and minor >= 8:
78 self.write = self._write_new_cffi
80 self.write = self._write_legacy_cffi
82 def connect(self, name, pfx, msg_handler, rx_qlen):
86 return vpp_api.vac_connect(name.encode('ascii'), pfx, msg_handler, rx_qlen)
89 self.connected = False
90 return vpp_api.vac_disconnect()
93 vpp_api.vac_rx_suspend()
96 vpp_api.vac_rx_resume()
98 def get_callback(self, do_async):
99 return vac_callback_sync if not do_async else vac_callback_async
101 def get_msg_index(self, name):
102 return vpp_api.vac_get_msg_index(name.encode('ascii'))
104 def msg_table_max_index(self):
105 return vpp_api.vac_msg_table_max_index()
107 def _write_new_cffi(self, buf):
108 """Send a binary-packed message to VPP."""
109 if not self.connected:
110 raise VppTransportShmemIOError(1, 'Not connected')
111 return vpp_api.vac_write(ffi.from_buffer(buf), len(buf))
113 def _write_legacy_cffi(self, buf):
114 """Send a binary-packed message to VPP."""
115 if not self.connected:
116 raise VppTransportShmemIOError(1, 'Not connected')
117 return vpp_api.vac_write(bytes(buf), len(buf))
120 if not self.connected:
121 raise VppTransportShmemIOError(1, 'Not connected')
122 mem = ffi.new("char **")
123 size = ffi.new("int *")
124 rv = vpp_api.vac_read(mem, size, self.read_timeout)
126 strerror = 'vac_read failed. It is likely that VPP died.'
127 raise VppTransportShmemIOError(rv, strerror)
128 msg = bytes(ffi.buffer(mem[0], size[0]))
129 vpp_api.vac_free(mem[0])