init: add re-exec capability

This will allow the re-execution of the init process after upgrading
OpenRC.
This commit is contained in:
William Hubbs 2017-04-12 17:56:30 -05:00
parent 6f88ee4ec6
commit 05738bfce1
3 changed files with 37 additions and 6 deletions

View File

@ -19,11 +19,13 @@
.Op Fl H , -halt
.Op Fl k , -kexec
.Op Fl p , -poweroff
.Op Fl R , -reexec
.Op Fl r , -reboot
.Sh DESCRIPTION
.Nm
is the utility that communicates with openrc-init(8) to bring down the
system. The following options affect how the system is brought down:
system or instruct openrc-init to re-execute itself. It supports the
following options:
.Bl -tag -width "poweroff"
.It Fl H , -halt
Stop all services, kill all remaining processes and halt the system.
@ -32,6 +34,9 @@ Stop all services, kill all processes and boot directly into a new
kernel loaded via kexec(8).
.It Fl p , -poweroff
Stop all services, kill all processes and power off the system.
.It Fl R , -reexec
instruct openrc-init to re-exec itself. This should be used after an
upgrade of OpenRC if you are using openrc-init as your init process.
.It Fl r , -reboot
Stop all services, kill all processes and reboot the system.
.El

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@ -20,6 +20,7 @@
#include <errno.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@ -79,6 +80,12 @@ static void init(const char *default_runlevel)
waitpid(pid, NULL, 0);
}
static void handle_reexec(char *my_name)
{
execl(my_name, my_name, "reexec", NULL);
return;
}
static void handle_shutdown(const char *runlevel, int cmd)
{
pid_t pid;
@ -123,10 +130,11 @@ static void signal_handler(int sig)
int main(int argc, char **argv)
{
char *default_runlevel = NULL;
char *default_runlevel;
char buf[2048];
int count;
FILE *fifo;
bool reexec = false;
struct sigaction sa;
if (getpid() != 1)
@ -134,16 +142,22 @@ int main(int argc, char **argv)
if (argc > 1)
default_runlevel = argv[1];
else
default_runlevel = NULL;
if (default_runlevel && strcmp(default_runlevel, "reexec") == 0)
reexec = true;
printf("OpenRC init version %s starting\n", VERSION);
init(default_runlevel);
if (! reexec)
init(default_runlevel);
memset(&sa, 0, sizeof(sa));
sa.sa_handler = signal_handler;
sigaction(SIGCHLD, &sa, NULL);
sigaction(SIGINT, &sa, NULL);
reboot(RB_DISABLE_CAD);
if (mkfifo(RC_INIT_FIFO, 0600) == -1)
if (mkfifo(RC_INIT_FIFO, 0600) == -1 && errno != EEXIST)
perror("mkfifo");
for (;;) {
@ -166,6 +180,8 @@ int main(int argc, char **argv)
handle_shutdown("shutdown", RB_POWER_OFF);
else if (strcmp(buf, "reboot") == 0)
handle_shutdown("reboot", RB_AUTOBOOT);
else if (strcmp(buf, "reexec") == 0)
handle_reexec(argv[0]);
}
return 0;
}

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@ -35,11 +35,12 @@
const char *applet = NULL;
const char *extraopts = NULL;
const char *getoptstring = "kpr" getoptstring_COMMON;
const char *getoptstring = "HkpRr" getoptstring_COMMON;
const struct option longopts[] = {
{ "halt", no_argument, NULL, 'H'},
{ "kexec", no_argument, NULL, 'k'},
{ "poweroff", no_argument, NULL, 'p'},
{ "reexec", no_argument, NULL, 'R'},
{ "reboot", no_argument, NULL, 'r'},
longopts_COMMON
};
@ -47,11 +48,13 @@ const char * const longopts_help[] = {
"halt the system",
"reboot the system using kexec",
"power off the system",
"re-execute init (use after upgrading)",
"reboot the system",
longopts_help_COMMON
};
const char *usagestring = NULL;
const char *exclusive = "Select one of --halt, --kexec, --poweroff or --reboot";
const char *exclusive = "Select one of "
"--halt, --kexec, --poweroff, --reexec or --reboot";
static void send_cmd(const char *cmd)
{
@ -79,6 +82,7 @@ int main(int argc, char **argv)
bool do_kexec = false;
bool do_poweroff = false;
bool do_reboot = false;
bool do_reexec = false;
applet = basename_c(argv[0]);
if (geteuid() != 0)
@ -99,6 +103,10 @@ if (geteuid() != 0)
do_poweroff = true;
cmd_count++;
break;
case 'R':
do_reexec = true;
cmd_count++;
break;
case 'r':
do_reboot = true;
cmd_count++;
@ -118,5 +126,7 @@ if (geteuid() != 0)
send_cmd("poweroff");
else if (do_reboot)
send_cmd("reboot");
else if (do_reexec)
send_cmd("reexec");
return 0;
}