glibc/login/programs/utmpd.c
Ulrich Drepper fb19a1ec9e Update.
1999-01-04  Philip Blundell  <philb@gnu.org>

	* sysdeps/unix/sysv/linux/arm/register-dump.h: Correct widths of
	register values.
	* sysdeps/unix/sysv/linux/arm/sigcontextinfo.h: New file.

	* csu/version.c (banner): Update date.
	* elf/sprof.c: Likewise.
	* login/programs/utmpd.c: Likewise.
	* nss/getent.c: Likewise.
	* posix/getconf.c: Likewise.
	* Rules: Likewise.  Remove rules to generate obsolete empty.{c,o*}.
1999-01-04 17:21:50 +00:00

420 lines
9.8 KiB
C

/* Copyright (C) 1997, 1998, 1999 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Mark Kettenis <kettenis@phys.uva.nl>, 1997.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <libintl.h>
#include <locale.h>
#include <pwd.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include <sys/param.h>
#include <sys/select.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/un.h>
#include <syslog.h>
#include <unistd.h>
#include "utmpd.h"
#include "utmpd-private.h"
#ifndef DEFAULT_USER
#define DEFAULT_USER "daemon"
#endif
/* Get libc version number. */
#include <version.h>
#define PACKAGE _libc_intl_domainname
/* Long options. */
static const struct option long_options[] =
{
{ "debug", no_argument, NULL, 'd' },
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, 'V' },
{ NULL, 0, NULL, 0}
};
/* The UTMP database. */
utmp_database *utmp_db;
/* The socket for read only requests. */
int ro_sock = -1;
/* The socket for read/write requests. */
int rw_sock = -1;
/* Prototypes for the local functions. */
static void usage (int status) __attribute__ ((noreturn));
static void drop_priviliges (void);
static int make_socket (const char *name);
static void handle_requests (void) __attribute__ ((noreturn));
static void termination_handler (int signum);
static int check_pid (const char *file);
static int write_pid (const char *file);
int
main (int argc, char *argv[])
{
mode_t mask;
int debug;
int do_help;
int do_version;
int opt;
/* Set locale via LC_ALL. */
setlocale (LC_ALL, "");
/* Set the text message domain. */
textdomain (PACKAGE);
/* Initialize local variables. */
debug = 0;
do_help = 0;
do_version = 0;
while ((opt = getopt_long (argc, argv, "dhV", long_options, NULL)) != -1)
switch (opt)
{
case '\0': /* Long option. */
break;
case 'h':
do_help = 1;
break;
case 'd':
debug = 1;
break;
case 'V':
do_version = 1;
break;
default:
usage (EXIT_FAILURE);
}
/* Version information is reequested. */
if (do_version)
{
printf ("utmpd (GNU %s) %s\n", PACKAGE, VERSION);
printf (_("\
Copyright (C) %s Free Software Foundation, Inc.\n\
This is free software; see the source for copying conditions. There is NO\n\
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
"), "1999");
printf (_("Written by %s.\n"), "Mark Kettenis");
exit (EXIT_SUCCESS);
}
/* Help is requested. */
if (do_help)
usage (EXIT_SUCCESS);
signal (SIGINT, termination_handler);
signal (SIGQUIT, termination_handler);
signal (SIGTERM, termination_handler);
/* Check if we are already running. */
if (check_pid (_PATH_UTMPDPID))
error (EXIT_FAILURE, 0, _("already running"));
/* Cleanup files created by a previous `bind'. */
unlink (_PATH_UTMPD_RO);
unlink (_PATH_UTMPD_RW);
/* Open UTMP database. */
utmp_db = open_database (_PATH_UTMP "x", _PATH_UTMP);
if (utmp_db == NULL)
exit (EXIT_FAILURE);
/* Create sockets, with the right permissions. */
mask = umask (S_IXUSR | S_IXGRP | S_IXOTH);
ro_sock = make_socket (_PATH_UTMPD_RO);
umask (S_IXUSR | S_IRWXG | S_IRWXO);
rw_sock = make_socket (_PATH_UTMPD_RW);
umask (mask);
/* Set the sockets up to accept connections. */
if (listen (ro_sock, MAX_CONNECTIONS) < 0
|| listen (rw_sock, MAX_CONNECTIONS) < 0)
error (EXIT_FAILURE, errno,
_("cannot enable socket to accept connections"));
/* Behave like a daemon. */
if (!debug)
{
openlog ("utmpd", LOG_CONS | LOG_ODELAY, LOG_DAEMON);
if (daemon (0, 0) < 0)
error (EXIT_FAILURE, errno, _("cannot auto-background"));
forked = 1;
if (write_pid (_PATH_UTMPDPID) < 0)
warning (errno, "%s", _PATH_UTMPDPID);
/* Ignore job control signals. */
signal (SIGTTOU, SIG_IGN);
signal (SIGTTIN, SIG_IGN);
signal (SIGTSTP, SIG_IGN);
}
/* Drop priviliges. */
drop_priviliges ();
/* Handle incoming requests. */
handle_requests ();
}
/* Display usage information and exit. */
static void
usage (int status)
{
if (status != EXIT_SUCCESS)
fprintf (stderr, _("Try `%s --help' for more information.\n"),
program_invocation_name);
else
{
printf (_("\
Usage: %s [OPTION]...\n\
-d, --debug do not fork and display messages on the current tty\n\
-h, --help display this help and exit\n\
-V, --version output version information and exit\n"),
program_invocation_name);
fputs (_("\
Report bugs using the `glibcbug' script to <bugs@gnu.org>.\n"),
stdout);
}
exit (status);
}
/* Drop priviliges. */
static void
drop_priviliges (void)
{
struct passwd *pw;
pw = getpwnam (DEFAULT_USER);
if (pw)
{
seteuid (pw->pw_uid);
setegid (pw->pw_gid);
}
}
/* Make a socket in the file namespace using the filename NAME as the
socket's address. */
static int
make_socket (const char *name)
{
struct sockaddr_un addr;
size_t size;
int sock;
/* Create the socket. */
sock = socket (PF_UNIX, SOCK_STREAM, 0);
if (sock < 0)
error (EXIT_FAILURE, errno, _("cannot create socket"));
/* Bind a name to the socket. */
addr.sun_family = AF_UNIX;
strcpy (addr.sun_path, name);
/* The size of the address is the offset of the start
of the filename, plus its length, plus one for the
terminating null byte. */
size = (offsetof (struct sockaddr_un, sun_path)
+ strlen (addr.sun_path));
if (bind (sock, (struct sockaddr *) &addr, size) < 0)
error (EXIT_FAILURE, errno, "%s", name);
return sock;
}
/* Hanlde incoming requests. */
static
void handle_requests (void)
{
client_connection *connection;
fd_set active_read_fd_set;
fd_set active_write_fd_set;
fd_set read_fd_set;
fd_set write_fd_set;
int fd;
int maxfd; /* Highest used fd to optimize select/loop. */
/* Initialize the set of active sockets. */
FD_ZERO (&active_read_fd_set);
FD_ZERO (&active_write_fd_set);
FD_SET (rw_sock, &active_read_fd_set);
FD_SET (ro_sock, &active_read_fd_set);
maxfd = MAX (rw_sock, ro_sock);
while (1)
{
/* Block until input arrives on one or more active sockets. */
read_fd_set = active_read_fd_set;
write_fd_set = active_write_fd_set;
if (select (maxfd + 1, &read_fd_set, &write_fd_set, NULL, NULL) < 0)
error (EXIT_FAILURE, errno, _("cannot get input on sockets"));
/* Service all the sockets with input pending. */
for (fd = 0; fd <= maxfd; ++fd)
{
if (FD_ISSET (fd, &read_fd_set))
{
if (fd == ro_sock || fd == rw_sock)
{
int access = ((fd == rw_sock) ? (R_OK | W_OK) : R_OK);
connection = accept_connection (fd, access);
if (connection == NULL)
error (0, errno, _("cannot accept connection"));
FD_SET (connection->sock, &active_read_fd_set);
maxfd = MAX (maxfd, connection->sock);
}
else
{
connection = find_connection (fd);
if (connection == NULL)
error (EXIT_FAILURE, 0, _("cannot find connection"));
if (read_data (connection) < 0)
{
close_connection (connection);
FD_CLR (fd, &active_read_fd_set);
FD_CLR (fd, &active_write_fd_set);
}
if (connection->write_ptr > connection->write_base)
FD_SET (fd, &active_write_fd_set);
}
}
if (FD_ISSET (fd, &write_fd_set) &&
fd != rw_sock && fd != ro_sock)
{
connection = find_connection (fd);
if (connection == NULL)
error (EXIT_FAILURE, 0, _("cannot find connection"));
if (write_data (connection) < 0)
{
close_connection (connection);
FD_CLR (fd, &active_read_fd_set);
FD_CLR (fd, &active_write_fd_set);
}
if (connection->write_ptr == connection->write_base)
FD_CLR (fd, &active_write_fd_set);
}
}
/* Check if maxfd can be lowered. */
for (; maxfd >= 0; --maxfd)
{
if (FD_ISSET (maxfd, &active_read_fd_set)
|| FD_ISSET (maxfd, &active_write_fd_set))
break;
}
}
}
/* Cleanup. */
static void
termination_handler (int signum)
{
/* Close sockets. */
close (ro_sock);
close (rw_sock);
/* Restore user id. */
seteuid (getuid ());
/* Clean up the files created by `bind'. */
unlink (_PATH_UTMPD_RO);
unlink (_PATH_UTMPD_RW);
if (utmp_db)
close_database (utmp_db);
/* Clean up pid file. */
unlink (_PATH_UTMPDPID);
exit (EXIT_SUCCESS);
}
/* Returns 1 if the process in pid file FILE is running, 0 if not. */
static int
check_pid (const char *file)
{
FILE *fp;
fp = fopen (_PATH_UTMPDPID, "r");
if (fp)
{
pid_t pid;
fscanf (fp, "%d", &pid);
fclose (fp);
if (kill (pid, 0) == 0)
return 1;
}
return 0;
}
/* Write the current process id to the file FILE. Returns 0 if
successful, -1 if not. */
static int
write_pid (const char *file)
{
FILE *fp;
fp = fopen (_PATH_UTMPDPID, "w");
if (fp == NULL)
return -1;
fprintf (fp, "%d\n", getpid ());
if (ferror (fp))
return -1;
fclose (fp);
return 0;
}