bpo-40291: Add support for CAN_J1939 sockets (GH-19538)

Add support for CAN_J1939 sockets that wrap SAE J1939 protocol
functionality provided by Linux 5.4+ kernels.
This commit is contained in:
karl ding 2020-04-29 15:31:19 -07:00 committed by GitHub
parent fd33cdbd05
commit 360371f79c
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GPG Key ID: 4AEE18F83AFDEB23
8 changed files with 197 additions and 5 deletions

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@ -118,6 +118,10 @@ created. Socket addresses are represented as follows:
- :const:`CAN_ISOTP` protocol require a tuple ``(interface, rx_addr, tx_addr)``
where both additional parameters are unsigned long integer that represent a
CAN identifier (standard or extended).
- :const:`CAN_J1939` protocol require a tuple ``(interface, name, pgn, addr)``
where additional parameters are 64-bit unsigned integer representing the
ECU name, a 32-bit unsigned integer representing the Parameter Group Number
(PGN), and an 8-bit integer representing the address.
- A string or a tuple ``(id, unit)`` is used for the :const:`SYSPROTO_CONTROL`
protocol of the :const:`PF_SYSTEM` family. The string is the name of a
@ -428,6 +432,15 @@ Constants
.. versionadded:: 3.7
.. data:: CAN_J1939
CAN_J1939, in the CAN protocol family, is the SAE J1939 protocol.
J1939 constants, documented in the Linux documentation.
.. availability:: Linux >= 5.4.
.. versionadded:: 3.9
.. data:: AF_PACKET
PF_PACKET
@ -544,7 +557,8 @@ The following functions all create :ref:`socket objects <socket-objects>`.
default), :const:`SOCK_DGRAM`, :const:`SOCK_RAW` or perhaps one of the other
``SOCK_`` constants. The protocol number is usually zero and may be omitted
or in the case where the address family is :const:`AF_CAN` the protocol
should be one of :const:`CAN_RAW`, :const:`CAN_BCM` or :const:`CAN_ISOTP`.
should be one of :const:`CAN_RAW`, :const:`CAN_BCM`, :const:`CAN_ISOTP` or
:const:`CAN_J1939`.
If *fileno* is specified, the values for *family*, *type*, and *proto* are
auto-detected from the specified file descriptor. Auto-detection can be
@ -588,6 +602,9 @@ The following functions all create :ref:`socket objects <socket-objects>`.
``SOCK_NONBLOCK``, but ``sock.type`` will be set to
``socket.SOCK_STREAM``.
.. versionchanged:: 3.9
The CAN_J1939 protocol was added.
.. function:: socketpair([family[, type[, proto]]])
Build a pair of connected socket objects using the given address family, socket

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@ -80,6 +80,16 @@ def _have_socket_can_isotp():
s.close()
return True
def _have_socket_can_j1939():
"""Check whether CAN J1939 sockets are supported on this host."""
try:
s = socket.socket(socket.PF_CAN, socket.SOCK_DGRAM, socket.CAN_J1939)
except (AttributeError, OSError):
return False
else:
s.close()
return True
def _have_socket_rds():
"""Check whether RDS sockets are supported on this host."""
try:
@ -143,6 +153,8 @@ def socket_setdefaulttimeout(timeout):
HAVE_SOCKET_CAN_ISOTP = _have_socket_can_isotp()
HAVE_SOCKET_CAN_J1939 = _have_socket_can_j1939()
HAVE_SOCKET_RDS = _have_socket_rds()
HAVE_SOCKET_ALG = _have_socket_alg()
@ -2117,6 +2129,68 @@ def testBind(self):
raise
@unittest.skipUnless(HAVE_SOCKET_CAN_J1939, 'CAN J1939 required for this test.')
class J1939Test(unittest.TestCase):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.interface = "vcan0"
@unittest.skipUnless(hasattr(socket, "CAN_J1939"),
'socket.CAN_J1939 required for this test.')
def testJ1939Constants(self):
socket.CAN_J1939
socket.J1939_MAX_UNICAST_ADDR
socket.J1939_IDLE_ADDR
socket.J1939_NO_ADDR
socket.J1939_NO_NAME
socket.J1939_PGN_REQUEST
socket.J1939_PGN_ADDRESS_CLAIMED
socket.J1939_PGN_ADDRESS_COMMANDED
socket.J1939_PGN_PDU1_MAX
socket.J1939_PGN_MAX
socket.J1939_NO_PGN
# J1939 socket options
socket.SO_J1939_FILTER
socket.SO_J1939_PROMISC
socket.SO_J1939_SEND_PRIO
socket.SO_J1939_ERRQUEUE
socket.SCM_J1939_DEST_ADDR
socket.SCM_J1939_DEST_NAME
socket.SCM_J1939_PRIO
socket.SCM_J1939_ERRQUEUE
socket.J1939_NLA_PAD
socket.J1939_NLA_BYTES_ACKED
socket.J1939_EE_INFO_NONE
socket.J1939_EE_INFO_TX_ABORT
socket.J1939_FILTER_MAX
@unittest.skipUnless(hasattr(socket, "CAN_J1939"),
'socket.CAN_J1939 required for this test.')
def testCreateJ1939Socket(self):
with socket.socket(socket.PF_CAN, socket.SOCK_DGRAM, socket.CAN_J1939) as s:
pass
def testBind(self):
try:
with socket.socket(socket.PF_CAN, socket.SOCK_DGRAM, socket.CAN_J1939) as s:
addr = self.interface, socket.J1939_NO_NAME, socket.J1939_NO_PGN, socket.J1939_NO_ADDR
s.bind(addr)
self.assertEqual(s.getsockname(), addr)
except OSError as e:
if e.errno == errno.ENODEV:
self.skipTest('network interface `%s` does not exist' %
self.interface)
else:
raise
@unittest.skipUnless(HAVE_SOCKET_RDS, 'RDS sockets required for this test.')
class BasicRDSTest(unittest.TestCase):

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@ -0,0 +1 @@
Add support for CAN_J1939 sockets (available on Linux 5.4+)

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@ -1556,6 +1556,16 @@ makesockaddr(SOCKET_T sockfd, struct sockaddr *addr, size_t addrlen, int proto)
a->can_addr.tp.tx_id);
}
#endif /* CAN_ISOTP */
#ifdef CAN_J1939
case CAN_J1939:
{
return Py_BuildValue("O&KkB", PyUnicode_DecodeFSDefault,
ifname,
a->can_addr.j1939.name,
a->can_addr.j1939.pgn,
a->can_addr.j1939.addr);
}
#endif /* CAN_J1939 */
default:
{
return Py_BuildValue("(O&)", PyUnicode_DecodeFSDefault,
@ -2237,6 +2247,55 @@ getsockaddrarg(PySocketSockObject *s, PyObject *args,
return 1;
}
#endif /* CAN_ISOTP */
#ifdef CAN_J1939
case CAN_J1939:
{
PyObject *interfaceName;
struct ifreq ifr;
Py_ssize_t len;
uint64_t j1939_name;
uint32_t j1939_pgn;
uint8_t j1939_addr;
struct sockaddr_can *addr = &addrbuf->can;
if (!PyArg_ParseTuple(args, "O&KkB", PyUnicode_FSConverter,
&interfaceName,
&j1939_name,
&j1939_pgn,
&j1939_addr))
return 0;
len = PyBytes_GET_SIZE(interfaceName);
if (len == 0) {
ifr.ifr_ifindex = 0;
} else if ((size_t)len < sizeof(ifr.ifr_name)) {
strncpy(ifr.ifr_name, PyBytes_AS_STRING(interfaceName), sizeof(ifr.ifr_name));
ifr.ifr_name[(sizeof(ifr.ifr_name))-1] = '\0';
if (ioctl(s->sock_fd, SIOCGIFINDEX, &ifr) < 0) {
s->errorhandler();
Py_DECREF(interfaceName);
return 0;
}
} else {
PyErr_SetString(PyExc_OSError,
"AF_CAN interface name too long");
Py_DECREF(interfaceName);
return 0;
}
addr->can_family = AF_CAN;
addr->can_ifindex = ifr.ifr_ifindex;
addr->can_addr.j1939.name = j1939_name;
addr->can_addr.j1939.pgn = j1939_pgn;
addr->can_addr.j1939.addr = j1939_addr;
*len_ret = sizeof(*addr);
Py_DECREF(interfaceName);
return 1;
}
#endif /* CAN_J1939 */
default:
PyErr_Format(PyExc_OSError,
"%s(): unsupported CAN protocol", caller);
@ -7687,6 +7746,9 @@ PyInit__socket(void)
#ifdef CAN_ISOTP
PyModule_AddIntMacro(m, CAN_ISOTP);
#endif
#ifdef CAN_J1939
PyModule_AddIntMacro(m, CAN_J1939);
#endif
#endif
#ifdef HAVE_LINUX_CAN_RAW_H
PyModule_AddIntMacro(m, CAN_RAW_FILTER);
@ -7734,6 +7796,37 @@ PyInit__socket(void)
PyModule_AddIntConstant(m, "CAN_BCM_CAN_FD_FRAME", CAN_FD_FRAME);
#endif
#endif
#ifdef HAVE_LINUX_CAN_J1939_H
PyModule_AddIntMacro(m, J1939_MAX_UNICAST_ADDR);
PyModule_AddIntMacro(m, J1939_IDLE_ADDR);
PyModule_AddIntMacro(m, J1939_NO_ADDR);
PyModule_AddIntMacro(m, J1939_NO_NAME);
PyModule_AddIntMacro(m, J1939_PGN_REQUEST);
PyModule_AddIntMacro(m, J1939_PGN_ADDRESS_CLAIMED);
PyModule_AddIntMacro(m, J1939_PGN_ADDRESS_COMMANDED);
PyModule_AddIntMacro(m, J1939_PGN_PDU1_MAX);
PyModule_AddIntMacro(m, J1939_PGN_MAX);
PyModule_AddIntMacro(m, J1939_NO_PGN);
/* J1939 socket options */
PyModule_AddIntMacro(m, SO_J1939_FILTER);
PyModule_AddIntMacro(m, SO_J1939_PROMISC);
PyModule_AddIntMacro(m, SO_J1939_SEND_PRIO);
PyModule_AddIntMacro(m, SO_J1939_ERRQUEUE);
PyModule_AddIntMacro(m, SCM_J1939_DEST_ADDR);
PyModule_AddIntMacro(m, SCM_J1939_DEST_NAME);
PyModule_AddIntMacro(m, SCM_J1939_PRIO);
PyModule_AddIntMacro(m, SCM_J1939_ERRQUEUE);
PyModule_AddIntMacro(m, J1939_NLA_PAD);
PyModule_AddIntMacro(m, J1939_NLA_BYTES_ACKED);
PyModule_AddIntMacro(m, J1939_EE_INFO_NONE);
PyModule_AddIntMacro(m, J1939_EE_INFO_TX_ABORT);
PyModule_AddIntMacro(m, J1939_FILTER_MAX);
#endif
#ifdef SOL_RDS
PyModule_AddIntMacro(m, SOL_RDS);
#endif

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@ -144,6 +144,10 @@ typedef int socklen_t;
#include <linux/can/bcm.h>
#endif
#ifdef HAVE_LINUX_CAN_J1939_H
#include <linux/can/j1939.h>
#endif
#ifdef HAVE_SYS_SYS_DOMAIN_H
#include <sys/sys_domain.h>
#endif

4
configure vendored
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@ -8282,8 +8282,8 @@ fi
done
# On Linux, can.h and can/raw.h require sys/socket.h
for ac_header in linux/can.h linux/can/raw.h linux/can/bcm.h
# On Linux, can.h, can/bcm.h, can/j1939.h, can/raw.h require sys/socket.h
for ac_header in linux/can.h linux/can/bcm.h linux/can/j1939.h linux/can/raw.h
do :
as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
ac_fn_c_check_header_compile "$LINENO" "$ac_header" "$as_ac_Header" "

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@ -2236,8 +2236,8 @@ AC_CHECK_HEADERS(linux/vm_sockets.h,,,[
#endif
])
# On Linux, can.h and can/raw.h require sys/socket.h
AC_CHECK_HEADERS(linux/can.h linux/can/raw.h linux/can/bcm.h,,,[
# On Linux, can.h, can/bcm.h, can/j1939.h, can/raw.h require sys/socket.h
AC_CHECK_HEADERS(linux/can.h linux/can/bcm.h linux/can/j1939.h linux/can/raw.h,,,[
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif

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@ -622,6 +622,9 @@
/* Define to 1 if you have the <linux/can.h> header file. */
#undef HAVE_LINUX_CAN_H
/* Define to 1 if you have the <linux/can/j1939.h> header file. */
#undef HAVE_LINUX_CAN_J1939_H
/* Define if compiling using Linux 3.6 or later. */
#undef HAVE_LINUX_CAN_RAW_FD_FRAMES