5430f7f2bc
We finally got the OK from all contributors with non-trivial commits to relicense systemd from GPL2+ to LGPL2.1+. Some udev bits continue to be GPL2+ for now, but we are looking into relicensing them too, to allow free copy/paste of all code within systemd. The bits that used to be MIT continue to be MIT. The big benefit of the relicensing is that closed source code may now link against libsystemd-login.so and friends.
109 lines
3.6 KiB
C
109 lines
3.6 KiB
C
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
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#ifndef foosdshutdownhfoo
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#define foosdshutdownhfoo
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/***
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This file is part of systemd.
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Copyright 2010 Lennart Poettering
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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/* Interface for scheduling and cancelling timed shutdowns. */
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#include <inttypes.h>
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typedef enum sd_shutdown_mode {
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SD_SHUTDOWN_NONE = 0,
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SD_SHUTDOWN_REBOOT = 'r',
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SD_SHUTDOWN_POWEROFF = 'P',
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SD_SHUTDOWN_HALT = 'H',
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SD_SHUTDOWN_KEXEC = 'K'
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} sd_shutdown_mode_t;
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/* Calculate the size of the message as "offsetof(struct
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* sd_shutdown_command, wall_message) +
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* strlen(command.wall_message)" */
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__attribute__((packed)) struct sd_shutdown_command {
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/* Microseconds after the epoch 1970 UTC */
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uint64_t usec;
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/* H, P, r, i.e. the switches usually passed to
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* /usr/bin/shutdown to select whether to halt, power-off or
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* reboot the machine */
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sd_shutdown_mode_t mode:8;
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/* If non-zero, don't actually shut down, just pretend */
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unsigned dry_run:1;
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/* If non-zero, send our wall message */
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unsigned warn_wall:1;
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/* The wall message to send around. Leave empty for the
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* default wall message */
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char wall_message[];
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};
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/* The scheme is very simple:
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*
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* To schedule a shutdown, simply fill in and send a single
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* AF_UNIX/SOCK_DGRAM datagram with the structure above suffixed with
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* the wall message to the socket /run/systemd/shutdownd (leave an
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* empty wall message for the default shutdown message). To calculate
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* the size of the message use "offsetof(struct sd_shutdown_command,
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* wall_message) + strlen(command.wall_message)".
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*
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* To cancel a shutdown, do the same, but send an fully zeroed out
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* structure.
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*
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* To be notified about scheduled shutdowns, create an inotify watch
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* on /run/shutdown/. Whenever a file called "scheduled" appears a
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* shutdown is scheduled. If it is removed it is canceled. It is
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* replaced the scheduled shutdown has been changed. The file contains
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* a simple environment-like block, that contains information about
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* the scheduled shutdown:
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*
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* USEC=
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* encodes the time for the shutdown in usecs since the epoch UTC,
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* formatted as numeric string.
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*
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* WARN_WALL=
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* is 1 if a wall message shall be sent
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*
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* DRY_RUN=
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* is 1 if a dry run shutdown is scheduled
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*
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* MODE=
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* is the shutdown mode, one of "poweroff", "reboot", "halt", "kexec"
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*
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* WALL_MESSAGE=
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* is the wall message to use, with all special characters escape in C style.
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*
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* Note that some fields might be missing if they do not apply.
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*
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* Note that the file is first written to a temporary file and then
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* renamed, in order to provide atomic properties for readers: if the
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* file exists under the name "scheduled" it is guaranteed to be fully
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* written. A reader should ignore all files in that directory by any
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* other name.
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*
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* Scheduled shutdowns are only accepted from privileged processes,
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* but the directory may be watched and the file in it read by
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* anybody.
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*/
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#endif
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