Similarly to "setup" vs. "set up", "fallback" is a noun, and "fall back"
is the verb. (This is pretty clear when we construct a sentence in the
present continous: "we are falling back" not "we are fallbacking").
Fixed below systemd codesonar warning.
isprint() is invoked here with an argument of signed
type char, but only has defined behavior for int arguments that are
either representable as unsigned char or equal to the value
of macro EOF(-1).
As per codesonar report, in a number of libc implementations, isprint()
function implemented using lookup tables (arrays): passing in a
negative value can result in a read underrun.
When the kernel does not provide a modalias, we generate our own for usb devices.
For some reason, we generated the expected usb:vXXXXpYYYY string, suffixed by "*".
It was added that way already in 796b06c21b, but I
think that was a mistake, and Kay was thinking about the match pattern instead
of the matched string.
For example, for a qemu device:
old: "usb:v0627p0001*"
new: "usb:v0627p0001:QEMU USB Tablet"
On the match side, all hwdb files in the wild seem to be using match patterns
with "*" at the end. So we can add more stuff to our generated modalias with
impunity.
This will allow more obvious and more certain matches on USB devices. In
principle the vendor+product id should be unique, but it's only 8 digits, and
there's a high chance of people getting this wrong. And matching the wrong
device would be quite problematic. By including the name in the match string we
make a mismatch much less likely.
E.g. udevadm test prints "Invalid inotify descriptor." which is
meaningless without any context. I think it should be OK to call udev_watch_end()
from a cleanup path without any warning (even at debug level).
There is no reason to consider this wrong. In fact one could argue that +=
is more appropriate, because we always add to options, and not replace previous
assignments. If we output a debug message, we implicitly ask people to "fix" this,
and we shouldn't.
Also, all our rules use += right now.
Let's add a catalog entry explaining further details.
Most importantly though: talk to PID 1 directly, via the private D-Bus
socket, so that this actually works correctly during early boot, where
D-Bus is not around.
All devices behind a SPI controller have the same udev ID_PATH property.
This is a problem for predicable network names for CAN controllers.
CAN controllers, in contrast to Ethernet controllers, don't have a MAC
Address, so there's no way to tell two CAN controllers on the same SPI
host controller apart:
$ udevadm info /sys/class/net/can0
P: /devices/platform/soc/fe204000.spi/spi_master/spi0/spi0.1/net/can0
L: 0
E: DEVPATH=/devices/platform/soc/fe204000.spi/spi_master/spi0/spi0.1/net/can0
E: INTERFACE=can0
E: IFINDEX=3
E: SUBSYSTEM=net
E: USEC_INITIALIZED=11187199
E: ID_PATH=platform-fe204000.spi
E: ID_PATH_TAG=platform-fe204000_spi
E: SYSTEMD_ALIAS=/sys/subsystem/net/devices/can0
E: TAGS=:systemd:
$ udevadm info /sys/class/net/can1
P: /devices/platform/soc/fe204000.spi/spi_master/spi0/spi0.0/net/can1
L: 0
E: DEVPATH=/devices/platform/soc/fe204000.spi/spi_master/spi0/spi0.0/net/can1
E: INTERFACE=can1
E: IFINDEX=4
E: SUBSYSTEM=net
E: USEC_INITIALIZED=11192211
E: ID_PATH=platform-fe204000.spi
E: ID_PATH_TAG=platform-fe204000_spi
E: SYSTEMD_ALIAS=/sys/subsystem/net/devices/can1
E: TAGS=:systemd:
With this the chip select number is added to the ID_PATH, to make
predictable network names possible.
$ sudo udevadm info /sys/class/net/can0
P: /devices/platform/soc/fe204000.spi/spi_master/spi0/spi0.1/net/can0
L: 0
E: DEVPATH=/devices/platform/soc/fe204000.spi/spi_master/spi0/spi0.1/net/can0
E: INTERFACE=can0
E: IFINDEX=3
E: SUBSYSTEM=net
E: USEC_INITIALIZED=11187199
E: ID_PATH=platform-fe204000.spi-cs-1
E: ID_PATH_TAG=platform-fe204000_spi-cs-1
E: SYSTEMD_ALIAS=/sys/subsystem/net/devices/can0
E: TAGS=:systemd:
$ sudo udevadm info /sys/class/net/can1
P: /devices/platform/soc/fe204000.spi/spi_master/spi0/spi0.0/net/can1
L: 0
E: DEVPATH=/devices/platform/soc/fe204000.spi/spi_master/spi0/spi0.0/net/can1
E: INTERFACE=can1
E: IFINDEX=4
E: SUBSYSTEM=net
E: USEC_INITIALIZED=11192211
E: ID_PATH=platform-fe204000.spi-cs-0
E: ID_PATH_TAG=platform-fe204000_spi-cs-0
E: SYSTEMD_ALIAS=/sys/subsystem/net/devices/can1
E: TAGS=:systemd:
Prompted by the discussion on #16110, let's migrate more code to
fd_wait_for_event().
This only leaves 7 places where we call into poll()/poll() directly in
our entire codebase. (one of which is fd_wait_for_event() itself)
poll() sets POLLNVAL inside of the poll structures if an invalid fd is
passed. So far we generally didn't check for that, thus not taking
notice of the error. Given that this specific kind of error is generally
indication of a programming error, and given that our code is embedded
into our projects via NSS or because people link against our library,
let's explicitly check for this and convert it to EBADF.
(I ran into a busy loop because of this missing check when some of my
test code accidentally closed an fd it shouldn't close, so this is a
real thing)
On systemd systems we generally don't need to chdir() to root, we don't
need to setup /dev/ ourselves (as PID 1 does that during earliest boot),
and we don't need to set the OOM adjustment values, as that's done via
unit files.
Hence, drop this. if people want to use udev from other init systems
they should do this on their own, I am very sure it's a good thing to do
it from outside of udevd, so that fewer privileges are required by udevd. In
particular the dev_setup() stuff is something that people who build
their own non-systemd distros want to set up themselves anyway, in
particular as they already have to mount devtmpfs themselves anyway.
Note that this only drops stuff that isn't really necessary for testing
stuff, i.e. process properties and settings that don't matter if you
quickly want to invoke udev from a terminal session to test something.
To make Driver= in [Match] section work in containers.
Note that ID_NET_DRIVER= property in udev database is set with the
result of the ethtool. So, this should not change anything for
non-container cases.
Closes#15678.
This is a follow-up for 9f83091e3c.
Instead of reading the mtime off the configuration files after reading,
let's do so before reading, but with the fd we read the data from. This
is not only cleaner (as it allows us to save one stat()), but also has
the benefit that we'll detect changes that happen while we read the
files.
This also reworks unit file drop-ins to use the common code for
determining drop-in mtime, instead of reading system clock for that.
Since the separate binaries contain mostly the same code,
this almost halves the size of the installation.
before:
398K /bin/udevadm
391K /lib/systemd/systemd-udevd
after:
431K /bin/udevadm
0 /lib/systemd/systemd-udevd -> ../../bin/udevadm
Fixes: #14200
if someone implements https://systemd.io/BLOCK_DEVICE_LOCKING/ then we
shouldn't loudly complain about that.
This reverts back to the original behaviour from
3ebdb81ef088afd3b4c72b516beb5610f8c93a0d: when the lock is taken we
silently skip processing the device and sending out the messages for it.
ATA devices should use the ATA ids like port number and (possibly)
master/slave or multiplier id, not the generic SCSI ID.
Currently only port number is included in the link. With this patch
the link would be able to support more cases, which are a) when the
device is behind a port multiplexer b) the distinction between master
and slave (distinguished by target id).
I tried to verify scenario a) with this patch, but I failed to find a
machine with PMP SATA devices attached. But the link below
https://github.com/systemd/systemd/issues/3943
could show what's the difference. Here is my test for scenario b)
Current version:
linux-ql21:~ # ll /sys/class/block/sd[ab]
lrwxrwxrwx 1 root root 0 May 8 20:46 /sys/class/block/sda ->
../../devices/pci0000:00/0000:00:01.1/ata4/host3/target3:0:0/3:0:0:0/block/sda
lrwxrwxrwx 1 root root 0 May 8 20:46 /sys/class/block/sdb ->
../../devices/pci0000:00/0000:00:01.1/ata4/host3/target3:0:1/3:0:1:0/block/sdb
linux-ql21:~ # ll /dev/disk/by-path/pci-0000\:00\:01.1-ata-1
lrwxrwxrwx 1 root root 9 May 8 20:44
/dev/disk/by-path/pci-0000:00:01.1-ata-1 -> ../../sdb
linux-ql21:~ # udevadm info /sys/class/block/sda |grep by-path
S: disk/by-path/pci-0000:00:01.1-ata-1
E: DEVLINKS=/dev/disk/by-id/ata-VBOX_HARDDISK_VB3649e885-3e0cdd64
/dev/disk/by-id/scsi-0ATA_VBOX_HARDDISK_VB3649e885-3e0cdd64
/dev/disk/by-id/scsi-1ATA_VBOX_HARDDISK_VB3649e885-3e0cdd64
/dev/disk/by-path/pci-0000:00:01.1-ata-1
/dev/disk/by-id/scsi-SATA_VBOX_HARDDISK_VB3649e885-3e0cdd64
linux-ql21:~ # udevadm info /sys/class/block/sdb |grep by-path
S: disk/by-path/pci-0000:00:01.1-ata-1
E: DEVLINKS=/dev/disk/by-id/ata-VBOX_HARDDISK_VBc53b2498-d84ae8de
/dev/disk/by-id/scsi-SATA_VBOX_HARDDISK_VBc53b2498-d84ae8de
/dev/disk/by-id/scsi-1ATA_VBOX_HARDDISK_VBc53b2498-d84ae8de
/dev/disk/by-id/scsi-0ATA_VBOX_HARDDISK_VBc53b2498-d84ae8de
/dev/disk/by-path/pci-0000:00:01.1-ata-1
After patch applied:
linux-ql21:~ # ll /sys/class/block/sd[ab]
lrwxrwxrwx 1 root root 0 May 8 21:07 /sys/class/block/sda ->
../../devices/pci0000:00/0000:00:01.1/ata4/host3/target3:0:0/3:0:0:0/block/sda
lrwxrwxrwx 1 root root 0 May 8 21:07 /sys/class/block/sdb ->
../../devices/pci0000:00/0000:00:01.1/ata4/host3/target3:0:1/3:0:1:0/block/sdb
linux-ql21:~ # ll /dev/disk/by-path/pci-0000\:00\:01.1-ata-*
lrwxrwxrwx 1 root root 9 May 8 21:07
/dev/disk/by-path/pci-0000:00:01.1-ata-1.0 -> ../../sda
lrwxrwxrwx 1 root root 9 May 8 21:07
/dev/disk/by-path/pci-0000:00:01.1-ata-1.1 -> ../../sdb
linux-ql21:~ # udevadm info /sys/class/block/sda |grep by-path
S: disk/by-path/pci-0000:00:01.1-ata-1.0
E: DEVLINKS=/dev/disk/by-id/scsi-1ATA_VBOX_HARDDISK_VB3649e885-3e0cdd64
/dev/disk/by-id/scsi-0ATA_VBOX_HARDDISK_VB3649e885-3e0cdd64
/dev/disk/by-id/ata-VBOX_HARDDISK_VB3649e885-3e0cdd64
/dev/disk/by-path/pci-0000:00:01.1-ata-1.0
/dev/disk/by-id/scsi-SATA_VBOX_HARDDISK_VB3649e885-3e0cdd64
linux-ql21:~ # udevadm info /sys/class/block/sdb |grep by-path
S: disk/by-path/pci-0000:00:01.1-ata-1.1
E: DEVLINKS=/dev/disk/by-id/scsi-0ATA_VBOX_HARDDISK_VBc53b2498-d84ae8de
/dev/disk/by-id/ata-VBOX_HARDDISK_VBc53b2498-d84ae8de
/dev/disk/by-id/scsi-1ATA_VBOX_HARDDISK_VBc53b2498-d84ae8de
/dev/disk/by-id/scsi-SATA_VBOX_HARDDISK_VBc53b2498-d84ae8de
/dev/disk/by-path/pci-0000:00:01.1-ata-1.1
Changelog:
v5: add another parameter compat_link in handle_scsi()
v4: comment for ID_PATH_ATA_COMPAT
get string length with pointer difference
(suggested by Franck Bui<fbui@suse.com>)
v3: creating compatible link from env
variables type change
v2: remove udev rules modification for compatible link
setup a test scenario of master/slave ATA devices
v1: initial patch
And do not use it in the IMPORT{cmdline} udev code. Wherever we expose
direct interfaces to check the kernel cmdline, let's not consult our
systemd-specific EFI variable, but strictly use the actual kernel
variable, because that's what we claim we do. i.e. it's fine to use the
EFI variable for our own settings, but for the generic APIs to the
kernel cmdline we should not use it.
Specifically, this applies to IMPORT{cmdline} and
ConditionKernelCommandLine=. In the latter case we weren#t checking the
EFI variable anyway, hence let's do the same for the udev case, too.
Fixes: #15739
This is a security feature, and we thus shouldn't derive the random MACs
from a potentially guessable source. MAC addresses are after all facing
to the outside, and can be interacted with from untrusted environments.
Hence, let's generate them the same way as we generate UUIDs: from
getrandom() or /dev/urandom, and optionally with RDRAND if that's
supported.
RDRAND should be fine, since this is not cryptographic key material, but
ultimately public information. We just want to make sure conflicts are
not likely.
Previously we'd generate the MACs via rand(), which means given the
short seed they are a little bit too guessable, making collisions too
likely. See #14355 in particular.
Fixes: #14355
(Note that #14355 was already fixed by
a0f11d1d11, but I think we should do
better even, and not rely on rand() and uninitialized random pools)
When setting flow control attributes of an interface we first acquire
the current settings and then add in the new settings before applying
them again. This only works on interfaces that implement the ethtool
ioctls. on others we'll see an ugly "Could not set flow control of"
message, simply because we issue the SIOCETHTOOL ioctl once, for getting
the data. In particular we'll get it for the "lo" interface all the
time, which sucks hard. Let's get rid of it.
