priod: PoC skeleton

This commit is contained in:
Přemysl Eric Janouch 2017-07-05 03:09:23 +02:00
parent cca674789b
commit 5b334e4111
Signed by: p
GPG Key ID: B715679E3A361BE6
3 changed files with 347 additions and 5 deletions

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@ -48,6 +48,9 @@ target_link_libraries (input-switch ${project_libraries})
add_executable (fancontrol-ng fancontrol-ng.c) add_executable (fancontrol-ng fancontrol-ng.c)
target_link_libraries (fancontrol-ng ${project_libraries}) target_link_libraries (fancontrol-ng ${project_libraries})
add_executable (priod priod.c)
target_link_libraries (priod ${project_libraries})
if (WITH_GDM) if (WITH_GDM)
include_directories (${gdm_INCLUDE_DIRS}) include_directories (${gdm_INCLUDE_DIRS})
add_executable (gdm-switch-user gdm-switch-user.c) add_executable (gdm-switch-user gdm-switch-user.c)
@ -75,11 +78,13 @@ install (FILES ${PROJECT_BINARY_DIR}/fancontrol-ng.service
install (FILES fancontrol-ng.conf.example install (FILES fancontrol-ng.conf.example
DESTINATION ${CMAKE_INSTALL_DATADIR}/fancontrol-ng) DESTINATION ${CMAKE_INSTALL_DATADIR}/fancontrol-ng)
# TODO: priod is also going to need a systemd unit file
if (WITH_GDM) if (WITH_GDM)
install (TARGETS gdm-switch-user DESTINATION ${CMAKE_INSTALL_BINDIR}) install (TARGETS gdm-switch-user DESTINATION ${CMAKE_INSTALL_BINDIR})
endif (WITH_GDM) endif (WITH_GDM)
install (TARGETS wmstatus brightness input-switch fancontrol-ng siprandom install (TARGETS wmstatus brightness input-switch fancontrol-ng priod siprandom
DESTINATION ${CMAKE_INSTALL_BINDIR}) DESTINATION ${CMAKE_INSTALL_BINDIR})
install (PROGRAMS shellify DESTINATION ${CMAKE_INSTALL_BINDIR}) install (PROGRAMS shellify DESTINATION ${CMAKE_INSTALL_BINDIR})
install (FILES LICENSE DESTINATION ${CMAKE_INSTALL_DOCDIR}) install (FILES LICENSE DESTINATION ${CMAKE_INSTALL_DOCDIR})

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@ -5,14 +5,16 @@ desktop-tools
'desktop-tools' is a collection of tools to run my desktop that might be useful 'desktop-tools' is a collection of tools to run my desktop that might be useful
to other people as well: to other people as well:
- 'wmstatus' does literally everything my dwm doesn't but I'd like it to. It - 'wmstatus' does literally everything my i3 doesn't but I'd like it to. It
includes PulseAudio volume management and hand-written NUT and MPD clients, includes PulseAudio volume management and hand-written NUT and MPD clients,
all in the name of liberation from GPL-licensed software of course. all in the name of liberation from GPL-licensed software of course
- 'brightness' allows me to change the brightness of w/e display device I have. - 'brightness' allows me to change the brightness of w/e display device I have
- 'input-switch' likewise switches the input source of external displays. - 'input-switch' likewise switches the input source of external displays
- 'fancontrol-ng' is a clone of fancontrol that can handle errors on resume - 'fancontrol-ng' is a clone of fancontrol that can handle errors on resume
from suspend instead of setting fans to maximum speed and quitting; from suspend instead of setting fans to maximum speed and quitting;
in general it doesn't handle everything the original does in general it doesn't handle everything the original does
- 'priod' sets CPU, I/O and OOM killer priorities for new processes according
to configuration
- 'shellify' is a simple script that sets up a shell for commands like vgdb - 'shellify' is a simple script that sets up a shell for commands like vgdb
and nmcli that are painfully lacking it and nmcli that are painfully lacking it
- 'gdm-switch-user' tells the running GDM daemon, if any, to show the switch - 'gdm-switch-user' tells the running GDM daemon, if any, to show the switch

335
priod.c Normal file
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@ -0,0 +1,335 @@
/*
* priod.c: process reprioritizing daemon
*
* Thanks to http://netsplit.com/the-proc-connector-and-socket-filters
*
* Copyright (c) 2017, Přemysl Janouch <p.janouch@gmail.com>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
#define _GNU_SOURCE
#define LIBERTY_WANT_POLLER
#include "config.h"
#undef PROGRAM_NAME
#define PROGRAM_NAME "priod"
#include "liberty/liberty.c"
#include <linux/cn_proc.h>
#include <linux/netlink.h>
#include <linux/connector.h>
#include <sys/resource.h>
#include <sys/syscall.h>
// --- Main program ------------------------------------------------------------
struct app_context
{
struct poller poller; ///< Poller
bool polling; ///< The event loop is running
int proc_fd; ///< Proc connector FD
struct poller_fd proc_event; ///< Proc connector read event
};
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
static void
log_message_custom (void *user_data, const char *quote, const char *fmt,
va_list ap)
{
(void) user_data;
FILE *stream = stdout;
// TODO: sd-daemon.h log level prefixes?
fputs (quote, stream);
vfprintf (stream, fmt, ap);
fputs ("\n", stream);
}
// --- Signals -----------------------------------------------------------------
static int g_signal_pipe[2]; ///< A pipe used to signal... signals
static void
sigterm_handler (int signum)
{
(void) signum;
int original_errno = errno;
if (write (g_signal_pipe[1], "", 1) == -1)
soft_assert (errno == EAGAIN);
errno = original_errno;
}
static void
setup_signal_handlers (void)
{
if (pipe (g_signal_pipe) == -1)
exit_fatal ("%s: %s", "pipe", strerror (errno));
set_cloexec (g_signal_pipe[0]);
set_cloexec (g_signal_pipe[1]);
// So that the pipe cannot overflow; it would make write() block within
// the signal handler, which is something we really don't want to happen.
// The same holds true for read().
set_blocking (g_signal_pipe[0], false);
set_blocking (g_signal_pipe[1], false);
(void) signal (SIGPIPE, SIG_IGN);
struct sigaction sa;
sa.sa_flags = SA_RESTART;
sa.sa_handler = sigterm_handler;
sigemptyset (&sa.sa_mask);
if (sigaction (SIGINT, &sa, NULL) == -1
|| sigaction (SIGTERM, &sa, NULL) == -1)
exit_fatal ("sigaction: %s", strerror (errno));
}
// --- Main program ------------------------------------------------------------
// IO priorities are a sort-of-private kernel API with no proper headers
enum
{
IOPRIO_CLASS_NONE,
IOPRIO_CLASS_RT,
IOPRIO_CLASS_BE,
IOPRIO_CLASS_IDLE,
};
enum
{
IOPRIO_WHO_PROCESS = 1,
IOPRIO_WHO_PGRP,
IOPRIO_WHO_USER,
};
#define IOPRIO_CLASS_SHIFT 13
static void
on_exec_name (struct app_context *ctx, int pid, const char *name)
{
print_status ("exec %d %s", pid, name);
if (true)
return;
setpriority (PRIO_PROCESS, pid, 0 /* TODO -20..20 */);
// TODO: this is per thread, and there's an inherent race condition;
// keep going through /proc/%d/task and reprioritize all threads;
// stop trying after N-th try
syscall (SYS_ioprio_set, IOPRIO_WHO_PROCESS,
IOPRIO_CLASS_BE << IOPRIO_CLASS_SHIFT | 0 /* TODO 0..7 */);
char *path = xstrdup_printf ("/proc/%d/oom_score_adj", pid);
struct error *e = NULL;
// TODO: figure out the contents
if (!write_file (path, "", 0, &e))
{
print_error ("%s", e->message);
error_free (e);
}
free (path);
}
static void
on_exec (struct app_context *ctx, int pid)
{
char *path = xstrdup_printf ("/proc/%d/cmdline", pid);
struct str cmdline;
str_init (&cmdline);
struct error *e = NULL;
if (read_file (path, &cmdline, &e))
on_exec_name (ctx, pid, cmdline.str);
else
{
print_debug ("%s", e->message);
error_free (e);
}
free (path);
str_free (&cmdline);
}
static void
on_netlink_message (struct app_context *ctx, struct nlmsghdr *mh)
{
if (mh->nlmsg_type == NLMSG_ERROR
|| mh->nlmsg_type == NLMSG_NOOP)
return;
struct cn_msg *m = NLMSG_DATA (mh);
if (m->id.idx != CN_IDX_PROC
|| m->id.val != CN_VAL_PROC)
return;
struct proc_event *e = (struct proc_event *) m->data;
if (e->what == PROC_EVENT_EXEC)
on_exec (ctx, e->event_data.exit.process_tgid);
}
static void
on_event (const struct pollfd *pfd, struct app_context *ctx)
{
char buf[4096];
struct sockaddr_nl addr;
while (true)
{
socklen_t addr_len = sizeof addr;
ssize_t len = recvfrom (pfd->fd, buf, sizeof buf, 0,
(struct sockaddr *) &addr, &addr_len);
if (len == 0)
exit_fatal ("socket closed");
if (len < 0 && errno == EAGAIN)
return;
if (len < 0)
exit_fatal ("recvfrom: %s", strerror (errno));
// Make sure it comes from the kernel
if (addr.nl_pid)
continue;
for (struct nlmsghdr *mh = (struct nlmsghdr *) buf;
NLMSG_OK (mh, len); mh = NLMSG_NEXT (mh, len))
on_netlink_message (ctx, mh);
}
}
static void
on_signal_pipe_readable (const struct pollfd *fd, struct app_context *ctx)
{
char id = 0;
(void) read (fd->fd, &id, 1);
ctx->polling = false;
}
static const char *
parse_program_arguments (int argc, char **argv)
{
static const struct opt opts[] =
{
{ 'd', "debug", NULL, 0, "run in debug mode" },
{ 'h', "help", NULL, 0, "display this help and exit" },
{ 'V', "version", NULL, 0, "output version information and exit" },
{ 0, NULL, NULL, 0, NULL }
};
struct opt_handler oh;
opt_handler_init (&oh, argc, argv, opts, "CONFIG", "Fan controller.");
int c;
while ((c = opt_handler_get (&oh)) != -1)
switch (c)
{
case 'd':
g_debug_mode = true;
break;
case 'h':
opt_handler_usage (&oh, stdout);
exit (EXIT_SUCCESS);
case 'V':
printf (PROGRAM_NAME " " PROGRAM_VERSION "\n");
exit (EXIT_SUCCESS);
default:
print_error ("wrong options");
opt_handler_usage (&oh, stderr);
exit (EXIT_FAILURE);
}
argc -= optind;
argv += optind;
if (argc != 1)
{
opt_handler_usage (&oh, stderr);
exit (EXIT_FAILURE);
}
opt_handler_free (&oh);
return argv[0];
}
int
main (int argc, char *argv[])
{
g_log_message_real = log_message_custom;
const char *config_path = parse_program_arguments (argc, argv);
struct app_context ctx;
memset (&ctx, 0, sizeof ctx);
poller_init (&ctx.poller);
setup_signal_handlers ();
struct poller_fd signal_event;
poller_fd_init (&signal_event, &ctx.poller, g_signal_pipe[0]);
signal_event.dispatcher = (poller_fd_fn) on_signal_pipe_readable;
signal_event.user_data = &ctx;
poller_fd_set (&signal_event, POLLIN);
// TODO: load configuration so that we know what to do with the events
ctx.proc_fd = socket (PF_NETLINK,
SOCK_DGRAM | SOCK_NONBLOCK | SOCK_CLOEXEC, NETLINK_CONNECTOR);
if (ctx.proc_fd < 0)
exit_fatal ("cannot make a proc connector: %s", strerror (errno));
struct sockaddr_nl addr = { .nl_family = AF_NETLINK, .nl_pid = getpid (),
.nl_groups = CN_IDX_PROC };
if (bind (ctx.proc_fd, (struct sockaddr *) &addr, sizeof addr) < 0)
exit_fatal ("cannot make a proc connector: %s", strerror (errno));
struct
{
// Beware of padding between fields, shouldn't be any on x86-64
union { struct nlmsghdr netlink; char align[NLMSG_HDRLEN]; };
struct cn_msg connector;
enum proc_cn_mcast_op op;
}
subscription =
{
.netlink.nlmsg_len = sizeof subscription,
.netlink.nlmsg_type = NLMSG_DONE,
.netlink.nlmsg_pid = getpid (),
.connector.id.idx = CN_IDX_PROC,
.connector.id.val = CN_VAL_PROC,
.connector.len = sizeof subscription.op,
.op = PROC_CN_MCAST_LISTEN,
};
if (write (ctx.proc_fd, &subscription, sizeof subscription) < 0)
exit_fatal ("failed to subscribe for events: %s", strerror (errno));
poller_fd_init (&ctx.proc_event, &ctx.poller, ctx.proc_fd);
ctx.proc_event.dispatcher = (poller_fd_fn) on_event;
ctx.proc_event.user_data = &ctx;
poller_fd_set (&ctx.proc_event, POLLIN);
ctx.polling = true;
while (ctx.polling)
poller_run (&ctx.poller);
poller_free (&ctx.poller);
xclose (ctx.proc_fd);
return EXIT_SUCCESS;
}