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);
27 void vac_mem_init (size_t size);
32 # allow file to be imported so it can be mocked in tests.
33 # If the shared library fails, VppTransport cannot be initialized.
35 vpp_api = ffi.dlopen('libvppapiclient.so')
40 @ffi.callback("void(unsigned char *, int)")
41 def vac_callback_sync(data, len):
42 vpp_object.msg_handler_sync(ffi.buffer(data, len))
45 @ffi.callback("void(unsigned char *, int)")
46 def vac_callback_async(data, len):
47 vpp_object.msg_handler_async(ffi.buffer(data, len))
50 @ffi.callback("void(void *, unsigned char *, int)")
51 def vac_error_handler(arg, msg, msg_len):
52 vpp_object.logger.warning("VPP API client:: %s", ffi.string(msg, msg_len))
55 class VppTransportShmemIOError(IOError):
56 """ exception communicating with vpp over shared memory """
58 def __init__(self, rv, descr):
62 super(VppTransportShmemIOError, self).__init__(rv, descr)
65 class VppTransport(object):
66 VppTransportShmemIOError = VppTransportShmemIOError
68 def __init__(self, parent, read_timeout, server_address):
69 self.connected = False
70 self.read_timeout = read_timeout
75 vpp_api.vac_mem_init(0)
77 # Register error handler
78 vpp_api.vac_set_error_handler(vac_error_handler)
81 # from_buffer supported from 1.8.0
82 (major, minor, patch) = [int(s) for s in
83 cffi.__version__.split('.', 3)]
84 if major >= 1 and minor >= 8:
85 self.write = self._write_new_cffi
87 self.write = self._write_legacy_cffi
89 def connect(self, name, pfx, msg_handler, rx_qlen):
93 return vpp_api.vac_connect(name.encode('ascii'), pfx, msg_handler, rx_qlen)
96 self.connected = False
97 return vpp_api.vac_disconnect()
100 vpp_api.vac_rx_suspend()
103 vpp_api.vac_rx_resume()
105 def get_callback(self, do_async):
106 return vac_callback_sync if not do_async else vac_callback_async
108 def get_msg_index(self, name):
109 return vpp_api.vac_get_msg_index(name.encode('ascii'))
111 def msg_table_max_index(self):
112 return vpp_api.vac_msg_table_max_index()
114 def _write_new_cffi(self, buf):
115 """Send a binary-packed message to VPP."""
116 if not self.connected:
117 raise VppTransportShmemIOError(1, 'Not connected')
118 return vpp_api.vac_write(ffi.from_buffer(buf), len(buf))
120 def _write_legacy_cffi(self, buf):
121 """Send a binary-packed message to VPP."""
122 if not self.connected:
123 raise VppTransportShmemIOError(1, 'Not connected')
124 return vpp_api.vac_write(bytes(buf), len(buf))
126 def read(self, timeout=None):
127 if not self.connected:
128 raise VppTransportShmemIOError(1, 'Not connected')
130 timeout = self.read_timeout
131 mem = ffi.new("char **")
132 size = ffi.new("int *")
133 rv = vpp_api.vac_read(mem, size, timeout)
135 strerror = 'vac_read failed. It is likely that VPP died.'
136 raise VppTransportShmemIOError(rv, strerror)
137 msg = bytes(ffi.buffer(mem[0], size[0]))
138 vpp_api.vac_free(mem[0])