This also
- merges basic/linux and shared/linux,
- moves BPF_JUMP_A() to basic/missing_bpf.h,
- copies from usrspace kernel headers directory generated by 'make headers',
rather than copying from kernel tree,
- copies const.h into our tree to reduce change in ethtool.h,
- copies auto_fs.h into our tree to reduce change in auto_dev-ioctl.h.
Builds with kernels headers < 4.14 fail with:
../src/shared/loop-util.c: In function ‘loop_configure_fallback’:
../src/shared/loop-util.c:237:31: error: ‘LOOP_SET_BLOCK_SIZE’ undeclared (first use in this function); did you mean ‘LOOP_SET_DIRECT_IO’?
if (ioctl(fd, LOOP_SET_BLOCK_SIZE, (unsigned long) c->block_size) < 0)
^~~~~~~~~~~~~~~~~~~
LOOP_SET_DIRECT_IO
Fixes: https://github.com/systemd/systemd/issues/33341
Signed-off-by: Raphaël Mélotte <raphael.melotte@mind.be>
Besides internal comparisons, the inode number of pidfds
might be interesting directly to users, too. In the future
this field should also be exposed, so that it can serve as
a unique identifier of a process (but only for display,
as there's no method to map this back to a pid or pidfd).
Also, make sure the NUL byte iovec becomes an exported constant too.
This is better than the previous situation where this was a macro
resolving to a compount expression, since the lifetime of the expression
is limited to its invoking scope. By turning this into a proper variable
the lifetime becomes unbounded, which makes it easier to use in various
scenarios, such as "if" blocks.
When looking at how dlopen for various libs is implemented, I found that the
macros hide too much. I find it much easier to see what is going on if 'extern'
and '= NULL' are written explicitly. After all, we don't hide those for other
definitions, e.g. our style guide says that static variables should be
initialized with '= NULL'. With that change, it's much more obvious what is
a variable declaration and what is a variable initialization.
- add missing assertions,
- use GREEDY_REALLOC() at one more place,
- etc.
Before:
```
$ sudo time valgrind --leak-check=full ./systemd-hwdb update
==112572== Memcheck, a memory error detector
==112572== Copyright (C) 2002-2024, and GNU GPL'd, by Julian Seward et al.
==112572== Using Valgrind-3.23.0 and LibVEX; rerun with -h for copyright info
==112572== Command: ./systemd-hwdb update
==112572==
==112572==
==112572== HEAP SUMMARY:
==112572== in use at exit: 0 bytes in 0 blocks
==112572== total heap usage: 1,320,113 allocs, 1,320,113 frees, 70,614,501 bytes allocated
==112572==
==112572== All heap blocks were freed -- no leaks are possible
==112572==
==112572== For lists of detected and suppressed errors, rerun with: -s
==112572== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
21.94user 0.19system 0:22.23elapsed 99%CPU (0avgtext+0avgdata 229876maxresident)k
0inputs+25264outputs (0major+57275minor)pagefaults 0swaps
```
After:
```
$ sudo time valgrind --leak-check=full ./systemd-hwdb update
[sudo] password for watanabe:
==114732== Memcheck, a memory error detector
==114732== Copyright (C) 2002-2024, and GNU GPL'd, by Julian Seward et al.
==114732== Using Valgrind-3.23.0 and LibVEX; rerun with -h for copyright info
==114732== Command: ./systemd-hwdb update
==114732==
==114732==
==114732== HEAP SUMMARY:
==114732== in use at exit: 0 bytes in 0 blocks
==114732== total heap usage: 1,276,406 allocs, 1,276,406 frees, 68,500,491 bytes allocated
==114732==
==114732== All heap blocks were freed -- no leaks are possible
==114732==
==114732== For lists of detected and suppressed errors, rerun with: -s
==114732== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
21.91user 0.24system 0:22.26elapsed 99%CPU (0avgtext+0avgdata 233584maxresident)k
0inputs+25168outputs (0major+58237minor)pagefaults 0swaps
```
This allows us to reserve a bunch of capacity ahead of time,
improving the performance of hwdb significantly thanks to not
having to reallocate so many times.
Before:
```
$ sudo time valgrind --leak-check=full ./systemd-hwdb update
==113297== Memcheck, a memory error detector
==113297== Copyright (C) 2002-2024, and GNU GPL'd, by Julian Seward et al.
==113297== Using Valgrind-3.23.0 and LibVEX; rerun with -h for copyright info
==113297== Command: ./systemd-hwdb update
==113297==
==113297==
==113297== HEAP SUMMARY:
==113297== in use at exit: 0 bytes in 0 blocks
==113297== total heap usage: 1,412,640 allocs, 1,412,640 frees, 117,920,009,195 bytes allocated
==113297==
==113297== All heap blocks were freed -- no leaks are possible
==113297==
==113297== For lists of detected and suppressed errors, rerun with: -s
==113297== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
132.44user 21.15system 2:35.61elapsed 98%CPU (0avgtext+0avgdata 228560maxresident)k
0inputs+25296outputs (0major+6886930minor)pagefaults 0swaps
```
After:
```
$ sudo time valgrind --leak-check=full ./systemd-hwdb update
==112572== Memcheck, a memory error detector
==112572== Copyright (C) 2002-2024, and GNU GPL'd, by Julian Seward et al.
==112572== Using Valgrind-3.23.0 and LibVEX; rerun with -h for copyright info
==112572== Command: ./systemd-hwdb update
==112572==
==112572==
==112572== HEAP SUMMARY:
==112572== in use at exit: 0 bytes in 0 blocks
==112572== total heap usage: 1,320,113 allocs, 1,320,113 frees, 70,614,501 bytes allocated
==112572==
==112572== All heap blocks were freed -- no leaks are possible
==112572==
==112572== For lists of detected and suppressed errors, rerun with: -s
==112572== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
21.94user 0.19system 0:22.23elapsed 99%CPU (0avgtext+0avgdata 229876maxresident)k
0inputs+25264outputs (0major+57275minor)pagefaults 0swaps
```
Co-authored-by: Yu Watanabe <watanabe.yu+github@gmail.com>
Multipath TCP (MPTCP), standardized in RFC8684 [1], is a TCP extension
that enables a TCP connection to use different paths. It allows a device
to make use of multiple interfaces at once to send and receive TCP
packets over a single MPTCP connection. MPTCP can aggregate the
bandwidth of multiple interfaces or prefer the one with the lowest
latency, it also allows a fail-over if one path is down, and the traffic
is seamlessly re-injected on other paths.
To benefit from MPTCP, both the client and the server have to support
it. Multipath TCP is a backward-compatible TCP extension that is enabled
by default on recent Linux distributions (Debian, Ubuntu, Redhat, ...).
Multipath TCP is included in the Linux kernel since version 5.6 [2]. To
use it on Linux, an application must explicitly enable it when creating
the socket:
int sd = socket(AF_INET(6), SOCK_STREAM, IPPROTO_MPTCP);
No need to change anything else in the application.
This patch allows MPTCP protocol in the Socket unit configuration. So
now, a <unit>.socket can contain this to use MPTCP instead of TCP:
[Socket]
SocketProtocol=mptcp
MPTCP support has been allowed similarly to what has been already done
to allow SCTP: just one line in core/socket.c, a very simple addition
thanks to the flexible architecture already in place.
On top of that, IPPROTO_MPTCP has also been added in the list of allowed
protocols in two other places, and in the doc. It has also been added to
the missing_network.h file, for systems with an old libc -- note that it
was also required to include <netinet/in.h> in this file to avoid
redefinition errors.
Link: https://www.rfc-editor.org/rfc/rfc8684.html [1]
Link: https://www.mptcp.dev [2]
Currently the check also succeeds if the input path starts with a dot, whereas
we only want it to succeed for "." and "./". Tighten the check and add a test.
