For similar reasons as the recent addition of a limit on sessions.
Note that we don't enforce a limit on inhibitors per-user currently, but
there's an implicit one, since each inhibitor takes up one fd, and fds are
limited via RLIMIT_NOFILE, and the limit on the number of processes per user.
If we have a lot of simultaneous sessions we really shouldn't send the full
list of active sessions with each PropertyChanged message for user and seat
objects, as that can become quite substantial data, we probably shouldn't dump
on the bus on each login and logout.
Note that the global list of sessions doesn't send out changes like this
either, it only supports requesting the session list with ListSessions().
If cients want to get notified about sessions coming and going they should
subscribe to SessionNew and SessionRemoved signals, and clients generally do
that already.
This is kind of an API break, but then again the fact that this was included
was never documented.
Let's make sure we process session and inhibitor pipe fds (that signal
sessions/inhibtors going away) at a higher priority
than new bus calls that might create new sessions or inhibitors. This helps
ensuring that the number of open sessions stays minimal.
We really should put limits on all resources we manage, hence add one to the
number of concurrent sessions, too. This was previously unbounded, hence set a
relatively high limit of 8K by default.
Note that most PAM setups will actually invoke pam_systemd prefixed with "-",
so that the return code of pam_systemd is ignored, and the login attempt
succeeds anyway. On systems like this the session will be created but is not
tracked by systemd.
When ACL support is enabled, systemd-tmpfiles-setup service sets the following
ACL entries to the volatile system journal:
$ getfacl /run/log/journal/*/system.journal
getfacl: Removing leading '/' from absolute path names
# file: run/log/journal/xxx/system.journal
# owner: root
# group: systemd-journal
user::rwx
group::r--
group🛞r-x
group:adm:r-x
mask::r-x
other::---
This patch makes sure that the exec bit is not set anymore for the volatile
system journals.
Commit 82501b3fc added an early break when a terminal node is found to
incorrect place -- before setting c. This caused trie to be built that
does not correspond to what it points to in buffer, causing incorrect
deduplications:
# cat /etc/udev/rules.d/99-bug.rules
ENV{FOO}=="0"
ENV{xx0}=="BAR"
ENV{BAZ}=="00"
# udevadm test
* RULE /etc/udev/rules.d/99-bug.rules:1, token: 0, count: 2, label: ''
M ENV match 'FOO' '0'(plain)
* RULE /etc/udev/rules.d/99-bug.rules:2, token: 2, count: 2, label: ''
M ENV match 'xx0' 'BAR'(plain)
* RULE /etc/udev/rules.d/99-bug.rules:3, token: 4, count: 2, label: ''
M ENV match 'BAZ' 'x0'(plain)
* END
The addition of "xx0" following "0" will cause a trie like this to be
created:
c=\0
c=0 "0"
c=0 "xx0" <-- note the c is incorrect here, causing "00" to be
c=O "FOO" deduplicated to it
c=R "BAR"
This in effect caused the usb_modeswitch rule for Huawei modems to never
match and this never be switched to serial mode from mass storage.
The previous implementation traversed the various config directories,
walking the preset files and parsing each line to determine if a service
should be enabled or disabled. It did this for every service which
resulted in many more file operations than neccessary.
This approach parses each of the preset entries into an array which is
then used to check if each service should be enabled or disabled.
networkd: add support to set route table
1. add support to configure the table id.
if id is less than 256 we can fit this in the header of route as
netlink property is a char. But in kernel this proepty is a
unsigned 32. Hence if greater that 256 add this as RTA_TABLE
attribute.
2. we are not setting the address family now. Now set this property.
Introduce
1. sd_rtnl_message_route_set_table to set table ID
2. sd_rtnl_message_route_set_family to set family
Both required to configure route properties.
This is essentially a revert of f38e0cce75 (which
removed the documentation of DUIDType on purpose). The description is heavily
updated for the new semantics.
This addresses #3127 § 4.
Separate fields are replaced with a struct.
Second second duid type field is removed. The first field was used to carry
the result of DUIDType= configuration, and the second was either a copy of
this, or contained the type extracted from DuidRawData. The semantics are changed
so that the type specified in DUIDType is always used. DUIDRawData= no longer
overrides the type setting.
The networkd code is now more constrained than the sd-dhcp code:
DUIDRawData cannot have 0 length, length 0 is treated the same as unsetting.
Likewise, it is not possible to set a DUIDType=0. If it ever becomes necessary
to set type=0 or a zero-length duid, the code can be changed to support that.
Nevertheless, I think that's unlikely.
This addresses #3127 § 1 and 3.
v2:
- rename DUID.duid, DUID.duid_len to DUID.raw_data, DUID.raw_data_len
Both versions of the code are changed to allow the caller to override
DUID using simple rules: duid type and value may be specified, in
which case the caller is responsible to providing the contents,
or just duid type may be specified as DUID_TYPE_EN, in which case we
we fill in the values. In the future more support for other types may
be added, e.g. DUID_TYPE_LLT.
There still remains and ugly discrepancy between dhcp4 and dhcp6 code:
dhcp6 has sd_dhcp6_client_set_duid and sd_dhcp6_client_set_iaid and
requires client->state to be DHCP6_STATE_STOPPED, while dhcp4 has
sd_dhcp_client_set_iaid_duid and will reconfigure the client if it
is not stopped. This commit doesn't touch that part.
This addresses #3127 § 2.
After all it is used in more than one place and is not that short.
Also tweak the test a bit:
- do not check that duid_len > 0, because we want to allow unknown
duid types, and there might be some which are fine with 0 length data,
(also assert should not be called from library code),
- always check that duid_len <= MAX_DUID_LEN, because we could overwrite
available buffer space otherwise.
Lennart Poettering