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/* initctl.c
Source file for initctl (init(8) control tool).
Copyright (C) 2000 Richard Gooch
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
Richard Gooch may be reached by email at rgooch@atnf.csiro.au
The postal address is:
Richard Gooch, c/o ATNF, P. O. Box 76, Epping, N.S.W., 2121, Australia.
*/
/*
This tool will send control messages to init(8). For example, it may
request init(8) to start a service and will wait for that service to be
available. If the service is already available, init(8) will not start it
again.
This tool may also be used to inspect the list of currently available
services.
Written by Richard Gooch 28-FEB-2000
Updated by Richard Gooch 11-OCT-2000: Added provide support.
Last updated by Richard Gooch 6-NOV-2000: Renamed to initctl.c
*/
#include <unistd.h>
#include <stdio.h>
#include <limits.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include "simpleinit.h"
static void signal_handler (int sig);
static int caught_signal = 0;
int main (int argc, char **argv)
{
int fd, nbytes;
struct sigaction sa;
sigset_t ss;
char *ptr;
long buffer[COMMAND_SIZE / sizeof (long) + 1];
struct command_struct *command = (struct command_struct *) buffer;
sigemptyset (&ss);
sigaddset (&ss, SIG_PRESENT);
sigaddset (&ss, SIG_NOT_PRESENT);
sigaddset (&ss, SIG_FAILED);
sigprocmask (SIG_BLOCK, &ss, NULL);
sigemptyset (&sa.sa_mask);
sa.sa_flags = 0;
sa.sa_handler = signal_handler;
sigaction (SIG_PRESENT, &sa, NULL);
sigaction (SIG_NOT_PRESENT, &sa, NULL);
sigaction (SIG_FAILED, &sa, NULL);
command->pid = getpid ();
command->ppid = getppid ();
if ( ( ptr = strrchr (argv[0], '/') ) == NULL ) ptr = argv[0];
else ++ptr;
/* First generate command number by looking at invocation name */
if (strcmp (ptr, "display-services") == 0)
command->command = COMMAND_DUMP_LIST;
else if (strcmp (ptr, "need") == 0) command->command = COMMAND_NEED;
else if (strcmp (ptr, "provide") == 0) command->command = COMMAND_PROVIDE;
else command->command = COMMAND_TEST;
/* Now check for switches */
if ( (argc > 1) && (argv[1][0] == '-') )
{
switch (argv[1][1])
{
case 'n':
command->command = COMMAND_NEED;
break;
case 'r':
command->command = COMMAND_ROLLBACK;
break;
case 'd':
command->command = COMMAND_DUMP_LIST;
break;
case 'p':
command->command = COMMAND_PROVIDE;
break;
default:
fprintf (stderr, "Illegal switch: \"%s\"\n", argv[1]);
exit (1);
/*break;*/
}
--argc;
++argv;
}
switch (command->command)
{
case COMMAND_NEED:
case COMMAND_PROVIDE:
if (argc < 2)
{
fprintf (stderr, "Usage:\tneed|provide programme\n");
exit (1);
}
/* Fall through */
case COMMAND_ROLLBACK:
if (argc > 1) strcpy (command->name, argv[1]);
else command->name[0] = '\0';
break;
case COMMAND_DUMP_LIST:
if (tmpnam (command->name) == NULL)
{
fprintf (stderr, "Unable to create a unique filename\t%s\n",
ERRSTRING);
exit (1);
}
if (mkfifo (command->name, S_IRUSR) != 0)
{
fprintf (stderr, "Unable to create FIFO: \"%s\"\t%s\n",
command->name, ERRSTRING);
exit (1);
}
break;
}
if ( ( fd = open ("/dev/initctl", O_WRONLY, 0) ) < 0 )
{
fprintf (stderr, "Error opening\t%s\n", ERRSTRING);
exit (1);
}
if (write (fd, buffer, COMMAND_SIZE) < COMMAND_SIZE)
{
fprintf (stderr, "Error writing\t%s\n", ERRSTRING);
exit (1);
}
close (fd);
if (command->command != COMMAND_DUMP_LIST)
{
sigemptyset (&ss);
while (caught_signal == 0) sigsuspend (&ss);
switch (command->command)
{
case COMMAND_PROVIDE:
switch (caught_signal)
{
case SIG_PRESENT:
return 1;
case SIG_NOT_PRESENT:
return 0;
case SIG_NOT_CHILD:
fprintf (stderr, "Error\n");
return 2;
default:
return 3;
}
break;
default:
switch (caught_signal)
{
case SIG_PRESENT:
return 0;
case SIG_NOT_PRESENT:
return 2;
case SIG_FAILED:
return 1;
default:
return 3;
}
break;
}
return 3;
}
/* Read back the data and display it */
if ( ( fd = open (command->name, O_RDONLY, 0) ) < 0 )
{
fprintf (stderr, "Error opening:\"%s\"\t%s\n",
command->name, ERRSTRING);
exit (1);
}
unlink (command->name);
fflush (stdout);
while ( ( nbytes = read (fd, buffer, COMMAND_SIZE) ) > 0 )
write (1, buffer, nbytes);
close (fd);
return (0);
} /* End Function main */
static void signal_handler (int sig)
{
caught_signal = sig;
} /* End Function signal_handler */
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