The socket module now has the socket.send_fds() and socket.recv.fds() functions.
Contributed by Joannah Nanjekye, Shinya Okano (original patch)
and Victor Stinner.
Co-Authored-By: Victor Stinner <vstinner@redhat.com>
Expose the CAN_BCM SocketCAN constants used in the bcm_msg_head struct
flags (provided by <linux/can/bcm.h>) under the socket library.
This adds the following constants with a CAN_BCM prefix:
* SETTIMER
* STARTTIMER
* TX_COUNTEVT
* TX_ANNOUNCE
* TX_CP_CAN_ID
* RX_FILTER_ID
* RX_CHECK_DLC
* RX_NO_AUTOTIMER
* RX_ANNOUNCE_RESUME
* TX_RESET_MULTI_IDX
* RX_RTR_FRAME
* CAN_FD_FRAME
The CAN_FD_FRAME flag was introduced in the 4.8 kernel, while the other
ones were present since SocketCAN drivers were mainlined in 2.6.25. As
such, it is probably unnecessary to guard against these constants being
missing.
At the moment you can definitely use UDPLITE sockets on Linux systems, but it would be good if this support were formalized such that you can detect support at runtime easily.
At the moment, to make and use a UDPLITE socket requires something like the following code:
```
>>> import socket
>>> a = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, 136)
>>> b = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, 136)
>>> a.bind(('localhost', 44444))
>>> b.sendto(b'test'*256, ('localhost', 44444))
>>> b.setsockopt(136, 10, 16)
>>> b.sendto(b'test'*256, ('localhost', 44444))
>>> b.setsockopt(136, 10, 32)
>>> b.sendto(b'test'*256, ('localhost', 44444))
>>> b.setsockopt(136, 10, 64)
>>> b.sendto(b'test'*256, ('localhost', 44444))
```
If you look at this through Wireshark, you can see that the packets are different in that the checksums and checksum coverages change.
With the pull request that I am submitting momentarily, you could do the following code instead:
```
>>> import socket
>>> a = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDPLITE)
>>> b = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDPLITE)
>>> a.bind(('localhost', 44444))
>>> b.sendto(b'test'*256, ('localhost', 44444))
>>> b.set_send_checksum_coverage(16)
>>> b.sendto(b'test'*256, ('localhost', 44444))
>>> b.set_send_checksum_coverage(32)
>>> b.sendto(b'test'*256, ('localhost', 44444))
>>> b.set_send_checksum_coverage(64)
>>> b.sendto(b'test'*256, ('localhost', 44444))
```
One can also detect support for UDPLITE just by checking
```
>>> hasattr(socket, 'IPPROTO_UDPLITE')
```
https://bugs.python.org/issue37345
It turns out doing socket.listen(0) does not equal to "choose a
reasonable default". It actually means "set backlog to 0".
As such set backlog=None as the default for socket.create_server.
Fixes the following BB failures:
https://github.com/python/cpython/pull/11784#issuecomment-481036369
Ref. BPO-1756, GH-11784.
Fix socket(fileno=fd) by auto-detecting the socket's family, type,
and proto from the file descriptor. The auto-detection can be overruled
by passing in family, type, and proto explicitly.
Without the fix, all socket except for TCP/IP over IPv4 are basically broken:
>>> s = socket.create_connection(('www.python.org', 443))
>>> s
<socket.socket fd=3, family=AddressFamily.AF_INET6, type=SocketKind.SOCK_STREAM, proto=6, laddr=('2003:58:bc4a:3b00:56ee:75ff:fe47:ca7b', 59730, 0, 0), raddr=('2a04:4e42:1b::223', 443, 0, 0)>
>>> socket.socket(fileno=s.fileno())
<socket.socket fd=3, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('2003:58:bc4a:3b00::%2550471192', 59730, 0, 2550471192), raddr=('2a04:4e42:1b:0:700c:e70b:ff7f:0%2550471192', 443, 0, 2550471192)>
Signed-off-by: Christian Heimes <christian@python.org>
* bpo-27584: New addition of vSockets to the python socket module
Support for AF_VSOCK on Linux only
* bpo-27584: Fixes for V2
Fixed syntax and naming problems.
Fixed #ifdef AF_VSOCK checking
Restored original aclocal.m4
* bpo-27584: Fixes for V3
Added checking for fcntl and thread modules.
* bpo-27584: Fixes for V4
Fixed white space error
* bpo-27584: Fixes for V5
Added back comma in (CID, port).
* bpo-27584: Fixes for V6
Added news file.
socket.rst now reflects first Linux introduction of AF_VSOCK.
Fixed get_cid in test_socket.py.
Replaced PyLong_FromLong with PyLong_FromUnsignedLong in socketmodule.c
Got rid of extra AF_VSOCK #define.
Added sockaddr_vm to sock_addr.
* bpo-27584: Fixes for V7
Minor cleanup.
* bpo-27584: Fixes for V8
Put back #undef AF_VSOCK as it is necessary when vm_sockets.h is not installed.
* Added support for CAN_ISOTP protocol
* Added unit tests for CAN ISOTP
* Updated documentation for ISO-TP protocol
* Removed trailing whitespace in documentation
* Added blurb NEWS.d file
* updated Misc/ACKS
* Fixed broken unit test that was using isotp const outside of skippable section
* Removed dependecy over third party project
* Added implementation for getsockname + unit tests
* Missing newline at end of ACKS file
* Accidentally inserted a type in ACKS file
* Followed tiran changes review #1 recommendations
* Added spaces after comma