I find myself wanting to check this data with a quick command, and
browsing through /sys/ manually getting binary data sucks. Hence let's
do add a nice little analysis tool.
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]
Previously, we did not set lifetime for redirect route, and redirect
routes were removed only when received a RA from the target address.
Thus, routes that redirect on-link addresses were never removed.
RFCs mention nothing about the lifetime of redirection. But the previous
implementation does not pass the IPv6 Core Conformance Tests.
This makes
- remember all received RAs and manage them by the sender address
(previously, remembered only one with the highest preference),
- then use the router lifetime as one for redirect route,
- remove redirect route also when the router corresponds to the sender
address is dropped (previously, considered only target address).
Note, even if we recieve a new RA, we do not update existing redirect
routes. The lifetime of the redirect route is updated only when a new
Redirect message is received.
Closes#32527.
CPUQuota= can deal with float percentages perfectly fine these days
(up to two places after the dot), so let's take that into account
when serializing the value to the transient unit file so we don't lose
precision when specifying e.g. "CPUQuota=0.5%".
A unit with StandardOutput=journal (the default) will get its stdout/stderr sockets
disconnected when journald stops, as the file descriptors on journald's side are
not preserved (it works on restart, as the FD Store keeps them open during restarts).
Set FileDescriptorStorePreserve=yes so that the journal FD's stay open during a soft
reboot, and applications don't get broken stdout/stderr.
It seems this introduced a regression in the CentOS CI;
14:25:58 FAILED TASKS:14:25:58 -------------
14:25:58 TEST-03-JOBS
14:25:58 TEST-52-HONORFIRSTSHUTDOWN
14:25:58 TEST-63-PATH
Revert for now.
This reverts commit da3c6fc553.
When DynamicUser= is enabled, we need LD_PRELOAD to be configured
correctly as the tests will load systemd's nss module which will complain
when built with sanitizers if the sanitizer libraries were not loaded
first.
This makes output a bit shorter and nicer. For us, shorter output is generally
better.
Also, drop unnecessary UINT64_C macros. The left operand is always uint64_t,
and C upcasting rules mean that it doesn't matter if the right operand is
narrower or signed, the operation is always done on the wider unsigned type.
The virtio-scsi driver is available in the KVM/cloud kernel
packages provided by distributions whereas the megasas2 driver is
not. Let's switch to virtio-scsi so we can switch back to the KVM/cloud
kernel packages.
PID1 may invoke a helper process, e.g. sd-close, during the test.
So, processes other than networkd and PID1 may be shown.
```
testtap99: tap pi multi_queue vnet_hdr persist filter
Attached to processes:systemd-network(2852)(sd-close)(2863)systemd(1)
```
Closes#33055.
