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 is now allowed to add new fields at the end of the PyTypeObject struct without having to allocate a dedicated compatibility flag in tp_flags.
This will reduce the risk of running out of bits in the 32-bit tp_flags value.
Add Clang Memory Sanitizer build instrumentation to work around
false positives from the socket and time modules as well as skipping
a couple test_faulthandler tests.
The length check for AF_ALG salg_name and salg_type had a off-by-one
error. The code assumed that both values are not necessarily NULL
terminated. However the Kernel code for alg_bind() ensures that the last
byte of both strings are NULL terminated.
Signed-off-by: Christian Heimes <christian@python.org>
Fix invalid function cast warnings with gcc 8
for method conventions different from METH_NOARGS, METH_O and
METH_VARARGS excluding Argument Clinic generated code.
METH_NOARGS functions need only a single argument but they are cast
into a PyCFunction, which takes two arguments. This triggers an
invalid function cast warning in gcc8 due to the argument mismatch.
Fix this by adding a dummy unused argument.
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>
* Fix compilation of the socket module on NetBSD 8.
* Fix the assertion failure or reading arbitrary data when parse
a AF_BLUETOOTH address on NetBSD and DragonFly BSD.
* Fix other potential errors and make the code more reliable.
Fix timeout rounding in time.sleep(), threading.Lock.acquire() and
socket.socket.settimeout() to round correctly negative timeouts between -1.0 and
0.0. The functions now block waiting for events as expected. Previously, the
call was incorrectly non-blocking.
* 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
sock_addr_t is used to define the minimum size of any socket address on
the stack. Let's make sure that an AF_ALG address always fits. Coverity
complains because in theory, AF_ALG might be larger than any of the other
structs. In practice it already fits.
Closes Coverity CID 1398948, 1398949, 1398950
Signed-off-by: Christian Heimes <christian@python.org>