This patch changes busctl capture to generate pcapng format
instead of the legacy pcap format files. It includes basic
meta-data in the file and still uses microsecond time
resolution. In future, more things can be added such as
high resolution timestams, statistics, etc.
PCAP Next Generation capture file format is what tshark uses
and is in process of being standardized in IETF. It is also
readable with libpcap.
$ capinfos /tmp/new.pcapng
File name: /tmp/new.pcapng
File type: Wireshark/... - pcapng
File encapsulation: D-Bus
File timestamp precision: microseconds (6)
Packet size limit: file hdr: (not set)
Packet size limit: inferred: 4096 bytes
Number of packets: 22
File size: 21kB
Data size: 20kB
Capture duration: 0.005694 seconds
First packet time: 2021-12-11 11:57:42.788374
Last packet time: 2021-12-11 11:57:42.794068
Data byte rate: 3,671kBps
Data bit rate: 29Mbps
Average packet size: 950.27 bytes
Average packet rate: 3,863 packets/s
SHA256: b85ed8b094af60c64aa6d9db4a91404e841736d36b9e662d707db9e4096148f1
RIPEMD160: 81f9bac7ec0ec5cd1d55ede136a5c90413894e3a
SHA1: 8400822ef724b934d6000f5b7604b9e6e91be011
Strict time order: True
Capture oper-sys: Linux 5.14.0-0.bpo.2-amd64
Capture application: systemd 250 (250-rc2-33-gdc79ae2+)
Number of interfaces in file: 1
Interface #0 info:
Encapsulation = D-Bus (146 - dbus)
Capture length = 4096
Time precision = microseconds (6)
Time ticks per second = 1000000
Number of stat entries = 0
Number of packets = 22
systemd-analyze critical-chain accepts an optional unit argument,
however currently there's no shell-completion for it
This change provides unit name completion for both bash and zsh.
Closes: #20927
Allows to pass a portable profile when doing offline analysis of
units. Especially useful for analyzing portable images, since a
lot of the security-relevant settings in those cases come from
the profiles, but they are not shipped in the portable images.
When using "capture : true" in custom_target()s the mode of the source
file is not preserved when the generated file is not installed and so
needs to be tweaked manually. Switch from output capture to creating the
target file and copy the permissions from the input file.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
This introduces `ExitType=main|cgroup` for services.
Similar to how `Type` specifies the launch of a service, `ExitType` is
concerned with how systemd determines that a service exited.
- If set to `main` (the current behavior), the service manager will consider
the unit stopped when the main process exits.
- The `cgroup` exit type is meant for applications whose forking model is not
known ahead of time and which might not have a specific main process.
The service will stay running as long as at least one process in the cgroup
is running. This is intended for transient or automatically generated
services, such as graphical applications inside of a desktop environment.
Motivation for this is #16805. The original PR (#18782) was reverted (#20073)
after realizing that the exit status of "the last process in the cgroup" can't
reliably be known (#19385)
This version instead uses the main process exit status if there is one and just
listens to the cgroup empty event otherwise.
The advantages of a service with `ExitType=cgroup` over scopes are:
- Integrated logging / stdout redirection
- Avoids the race / synchronisation issue between launch and scope creation
- More extensive use of drop-ins and thus distro-level configuration:
by moving from scopes to services we can have drop ins that will affect
properties that can only be set during service creation,
like `OOMPolicy` and security-related properties
- It makes systemd-xdg-autostart-generator usable by fixing [1], as obviously
only services can be used in the generator, not scopes.
[1] https://bugs.kde.org/show_bug.cgi?id=433299
This is supposed to be used by package/image builders such as mkosi to
speed up building, since it allows us to suppress sync() inside a
container.
This does what Debian's eatmydata tool does, but for a container, and
via seccomp (instead of LD_PRELOAD).
This option has coredumpctl look at all journals instead of only the
local ones. This allows coredumpctl to show information about remote
coredumps if the coredumps are made available in /var/lib/systemd/coredump
and the corresponding journals are made available in /var/log/journal.
This is already possible using the --directory option but --all makes it
more user friendly since users don't have to enter the journal directory
anymore as long as it's available under /var/log/journal.
The new option --json= works with the 'security' verb and takes in one of three format flags.
These are off which is the default, pretty and short which use JSON format flags for output.
When set to true, it generates a JSON formatted output of the security analysis table. The
format is a JSON array with objects containing the following fields: set which indicates if
the id has been set or not, name which is what is used to refer to the id, json_field
which is the equivalent JSON formatted id name only used for JSON outputs, description which
is an outline of the id state, and exposure which is an unsigned integer in the range 0.0..10.0,
where a higher value corresponds to a higher security threat. The JSON version of the table is
printed on the standard output file.
Example Run:
The unit file testfile.service was created to test the --json= option
maanya-goenka@debian:~/systemd (json-security)$ cat <<EOF >testfile.service
> [Service]
> ExecStart = echo hello
> PrivateNetwork = yes
> PrivateMounts = yes
> PrivateDevices = yes
> EOF
Both the JSON output and the security analysis table below have been truncated to increase readability.
1. Testing for when --json=off
maanya-goenka@debian:~/systemd (json-security)$ sudo build/systemd-analyze security --json=off --root= --offline=true
testfile.service --no-pager
/usr/lib/systemd/system/plymouth-start.service:15: Unit configured to use KillMode=none. This is unsafe, as it disables systemd's
process lifecycle management for the service. Please update your service to use a safer KillMode=, such as 'mixed' or 'control-group'.
Support for KillMode=none is deprecated and will eventually be removed.
/usr/lib/systemd/system/dbus.socket:5: ListenStream= references a path below legacy directory /var/run/, updating
/var/run/dbus/system_bus_socket → /run/dbus/system_bus_socket; please update the unit file accordingly.
/usr/lib/systemd/system/gdm.service:30: Standard output type syslog is obsolete, automatically updating to journal. Please update your
unit file, and consider removing the setting altogether.
/home/maanya-goenka/systemd/foo.service:2: Unknown key name 'foo' in section 'Unit', ignoring.
NAME DESCRIPTION EXPOSURE
✓ PrivateNetwork= Service has no access to the host's network
✗ User=/DynamicUser= Service runs as root user 0.4
✗ CapabilityBoundingSet=~CAP_SET(UID|GID|PCAP) Service may change UID/GID identities/capabilities 0.3
✗ CapabilityBoundingSet=~CAP_NET_ADMIN Service has administrator privileges 0.3
→ Overall exposure level for testfile.service: 8.3 EXPOSED 🙁
2. Testing for when --json=pretty
maanya-goenka@debian:~/systemd (json-security)$ sudo build/systemd-analyze security --json=pretty --root= --offline=true
testfile.service
/usr/lib/systemd/system/plymouth-start.service:15: Unit configured to use KillMode=none. This is unsafe, as it disables systemd's
process lifecycle management for the service. Please update your service to use a safer KillMode=, such as 'mixed' or 'control-group'.
Support for KillMode=none is deprecated and will eventually be removed.
/usr/lib/systemd/system/dbus.socket:5: ListenStream= references a path below legacy directory /var/run/, updating
/var/run/dbus/system_bus_socket → /run/dbus/system_bus_socket; please update the unit file accordingly.
/usr/lib/systemd/system/gdm.service:30: Standard output type syslog is obsolete, automatically updating to journal. Please update your
unit file, and consider removing the setting altogether.
/home/maanya-goenka/systemd/foo.service:2: Unknown key name 'foo' in section 'Unit', ignoring.
[
{
"set" : true,
"name" : "PrivateNetwork=",
"json-field" : "PrivateNetwork",
"description" : "Service has no access to the host's network",
"exposure" : null
},
{
"set" : false,
"name" : "User=/DynamicUser=",
"json-field" : "UserOrDynamicUser",
"decsription" : "Service runs as root user",
"exposure" : "0.4"
},
{
"set" : false,
"name" : "CapabilityBoundingSet=~CAP_SET(UID|GID|PCAP)",
"json_field" : "CapabilityBoundingSet_CAP_SET_UID_GID_PCAP",
"description" : "Service may change UID/GID identities/capabilities",
"exposure" : "0.3"
},
{
"set" : false,
"name" : "CapabilityBoundingSet=~CAP_NET_ADMIN",
"json_field" : "CapabilityBoundingSet_CAP_NET_ADMIN",
"description" : "Service has administrator privileges",
"exposure" : "0.3"
},
...
]
3. Testing for when --json=short
maanya-goenka@debian:~/systemd (json-security)$ sudo build/systemd-analyze security --json=short --root= --offline=true
testfile.service
/usr/lib/systemd/system/plymouth-start.service:15: Unit configured to use KillMode=none. This is unsafe, as it disables systemd's
process lifecycle management for the service. Please update your service to use a safer KillMode=, such as 'mixed' or 'control-group'.
Support for KillMode=none is deprecated and will eventually be removed.
/usr/lib/systemd/system/dbus.socket:5: ListenStream= references a path below legacy directory /var/run/, updating
/var/run/dbus/system_bus_socket → /run/dbus/system_bus_socket; please update the unit file accordingly.
/usr/lib/systemd/system/gdm.service:30: Standard output type syslog is obsolete, automatically updating to journal. Please update your
unit file, and consider removing the setting altogether.
/home/maanya-goenka/systemd/foo.service:2: Unknown key name 'foo' in section 'Unit', ignoring.
[{"set":true,"name":"PrivateNetwork=", "json_field":"PrivateNetwork", "description":"Service has no access to the host's network","exposure":null}, ...]
