| Current Path : /compat/linux/proc/self/root/usr/src/sbin/init/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : //compat/linux/proc/self/root/usr/src/sbin/init/init.c |
/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Donn Seeley at Berkeley Software Design, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1991, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)init.c 8.1 (Berkeley) 7/15/93";
#endif
static const char rcsid[] =
"$FreeBSD: release/9.1.0/sbin/init/init.c 233944 2012-04-06 11:09:49Z ed $";
#endif /* not lint */
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/sysctl.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <sys/uio.h>
#include <db.h>
#include <errno.h>
#include <fcntl.h>
#include <kenv.h>
#include <libutil.h>
#include <paths.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <time.h>
#include <ttyent.h>
#include <unistd.h>
#include <utmpx.h>
#include <sys/reboot.h>
#include <err.h>
#include <stdarg.h>
#ifdef SECURE
#include <pwd.h>
#endif
#ifdef LOGIN_CAP
#include <login_cap.h>
#endif
#include "pathnames.h"
/*
* Sleep times; used to prevent thrashing.
*/
#define GETTY_SPACING 5 /* N secs minimum getty spacing */
#define GETTY_SLEEP 30 /* sleep N secs after spacing problem */
#define GETTY_NSPACE 3 /* max. spacing count to bring reaction */
#define WINDOW_WAIT 3 /* wait N secs after starting window */
#define STALL_TIMEOUT 30 /* wait N secs after warning */
#define DEATH_WATCH 10 /* wait N secs for procs to die */
#define DEATH_SCRIPT 120 /* wait for 2min for /etc/rc.shutdown */
#define RESOURCE_RC "daemon"
#define RESOURCE_WINDOW "default"
#define RESOURCE_GETTY "default"
static void handle(sig_t, ...);
static void delset(sigset_t *, ...);
static void stall(const char *, ...) __printflike(1, 2);
static void warning(const char *, ...) __printflike(1, 2);
static void emergency(const char *, ...) __printflike(1, 2);
static void disaster(int);
static void badsys(int);
static int runshutdown(void);
static char *strk(char *);
/*
* We really need a recursive typedef...
* The following at least guarantees that the return type of (*state_t)()
* is sufficiently wide to hold a function pointer.
*/
typedef long (*state_func_t)(void);
typedef state_func_t (*state_t)(void);
static state_func_t single_user(void);
static state_func_t runcom(void);
static state_func_t read_ttys(void);
static state_func_t multi_user(void);
static state_func_t clean_ttys(void);
static state_func_t catatonia(void);
static state_func_t death(void);
static state_func_t death_single(void);
static state_func_t run_script(const char *);
enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT;
#define FALSE 0
#define TRUE 1
int Reboot = FALSE;
int howto = RB_AUTOBOOT;
int devfs;
static void transition(state_t);
static state_t requested_transition;
static state_t current_state = death_single;
static void setctty(const char *);
static const char *get_shell(void);
static void write_stderr(const char *message);
typedef struct init_session {
int se_index; /* index of entry in ttys file */
pid_t se_process; /* controlling process */
time_t se_started; /* used to avoid thrashing */
int se_flags; /* status of session */
#define SE_SHUTDOWN 0x1 /* session won't be restarted */
#define SE_PRESENT 0x2 /* session is in /etc/ttys */
int se_nspace; /* spacing count */
char *se_device; /* filename of port */
char *se_getty; /* what to run on that port */
char *se_getty_argv_space; /* pre-parsed argument array space */
char **se_getty_argv; /* pre-parsed argument array */
char *se_window; /* window system (started only once) */
char *se_window_argv_space; /* pre-parsed argument array space */
char **se_window_argv; /* pre-parsed argument array */
char *se_type; /* default terminal type */
struct init_session *se_prev;
struct init_session *se_next;
} session_t;
static void free_session(session_t *);
static session_t *new_session(session_t *, int, struct ttyent *);
static session_t *sessions;
static char **construct_argv(char *);
static void start_window_system(session_t *);
static void collect_child(pid_t);
static pid_t start_getty(session_t *);
static void transition_handler(int);
static void alrm_handler(int);
static void setsecuritylevel(int);
static int getsecuritylevel(void);
static int setupargv(session_t *, struct ttyent *);
#ifdef LOGIN_CAP
static void setprocresources(const char *);
#endif
static int clang;
static void clear_session_logs(session_t *);
static int start_session_db(void);
static void add_session(session_t *);
static void del_session(session_t *);
static session_t *find_session(pid_t);
static DB *session_db;
/*
* The mother of all processes.
*/
int
main(int argc, char *argv[])
{
state_t initial_transition = runcom;
char kenv_value[PATH_MAX];
int c;
struct sigaction sa;
sigset_t mask;
/* Dispose of random users. */
if (getuid() != 0)
errx(1, "%s", strerror(EPERM));
/* System V users like to reexec init. */
if (getpid() != 1) {
#ifdef COMPAT_SYSV_INIT
/* So give them what they want */
if (argc > 1) {
if (strlen(argv[1]) == 1) {
char runlevel = *argv[1];
int sig;
switch (runlevel) {
case '0': /* halt + poweroff */
sig = SIGUSR2;
break;
case '1': /* single-user */
sig = SIGTERM;
break;
case '6': /* reboot */
sig = SIGINT;
break;
case 'c': /* block further logins */
sig = SIGTSTP;
break;
case 'q': /* rescan /etc/ttys */
sig = SIGHUP;
break;
default:
goto invalid;
}
kill(1, sig);
_exit(0);
} else
invalid:
errx(1, "invalid run-level ``%s''", argv[1]);
} else
#endif
errx(1, "already running");
}
/*
* Note that this does NOT open a file...
* Does 'init' deserve its own facility number?
*/
openlog("init", LOG_CONS|LOG_ODELAY, LOG_AUTH);
/*
* Create an initial session.
*/
if (setsid() < 0)
warning("initial setsid() failed: %m");
/*
* Establish an initial user so that programs running
* single user do not freak out and die (like passwd).
*/
if (setlogin("root") < 0)
warning("setlogin() failed: %m");
/*
* This code assumes that we always get arguments through flags,
* never through bits set in some random machine register.
*/
while ((c = getopt(argc, argv, "dsf")) != -1)
switch (c) {
case 'd':
devfs = 1;
break;
case 's':
initial_transition = single_user;
break;
case 'f':
runcom_mode = FASTBOOT;
break;
default:
warning("unrecognized flag '-%c'", c);
break;
}
if (optind != argc)
warning("ignoring excess arguments");
/*
* We catch or block signals rather than ignore them,
* so that they get reset on exec.
*/
handle(badsys, SIGSYS, 0);
handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGXCPU,
SIGXFSZ, 0);
handle(transition_handler, SIGHUP, SIGINT, SIGTERM, SIGTSTP, SIGUSR1,
SIGUSR2, 0);
handle(alrm_handler, SIGALRM, 0);
sigfillset(&mask);
delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS,
SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGTERM, SIGTSTP, SIGALRM,
SIGUSR1, SIGUSR2, 0);
sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
sigemptyset(&sa.sa_mask);
sa.sa_flags = 0;
sa.sa_handler = SIG_IGN;
sigaction(SIGTTIN, &sa, (struct sigaction *)0);
sigaction(SIGTTOU, &sa, (struct sigaction *)0);
/*
* Paranoia.
*/
close(0);
close(1);
close(2);
if (kenv(KENV_GET, "init_script", kenv_value, sizeof(kenv_value)) > 0) {
state_func_t next_transition;
if ((next_transition = run_script(kenv_value)) != 0)
initial_transition = (state_t) next_transition;
}
if (kenv(KENV_GET, "init_chroot", kenv_value, sizeof(kenv_value)) > 0) {
if (chdir(kenv_value) != 0 || chroot(".") != 0)
warning("Can't chroot to %s: %m", kenv_value);
}
/*
* Additional check if devfs needs to be mounted:
* If "/" and "/dev" have the same device number,
* then it hasn't been mounted yet.
*/
if (!devfs) {
struct stat stst;
dev_t root_devno;
stat("/", &stst);
root_devno = stst.st_dev;
if (stat("/dev", &stst) != 0)
warning("Can't stat /dev: %m");
else if (stst.st_dev == root_devno)
devfs++;
}
if (devfs) {
struct iovec iov[4];
char *s;
int i;
char _fstype[] = "fstype";
char _devfs[] = "devfs";
char _fspath[] = "fspath";
char _path_dev[]= _PATH_DEV;
iov[0].iov_base = _fstype;
iov[0].iov_len = sizeof(_fstype);
iov[1].iov_base = _devfs;
iov[1].iov_len = sizeof(_devfs);
iov[2].iov_base = _fspath;
iov[2].iov_len = sizeof(_fspath);
/*
* Try to avoid the trailing slash in _PATH_DEV.
* Be *very* defensive.
*/
s = strdup(_PATH_DEV);
if (s != NULL) {
i = strlen(s);
if (i > 0 && s[i - 1] == '/')
s[i - 1] = '\0';
iov[3].iov_base = s;
iov[3].iov_len = strlen(s) + 1;
} else {
iov[3].iov_base = _path_dev;
iov[3].iov_len = sizeof(_path_dev);
}
nmount(iov, 4, 0);
if (s != NULL)
free(s);
}
/*
* Start the state machine.
*/
transition(initial_transition);
/*
* Should never reach here.
*/
return 1;
}
/*
* Associate a function with a signal handler.
*/
static void
handle(sig_t handler, ...)
{
int sig;
struct sigaction sa;
sigset_t mask_everything;
va_list ap;
va_start(ap, handler);
sa.sa_handler = handler;
sigfillset(&mask_everything);
while ((sig = va_arg(ap, int)) != 0) {
sa.sa_mask = mask_everything;
/* XXX SA_RESTART? */
sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0;
sigaction(sig, &sa, (struct sigaction *) 0);
}
va_end(ap);
}
/*
* Delete a set of signals from a mask.
*/
static void
delset(sigset_t *maskp, ...)
{
int sig;
va_list ap;
va_start(ap, maskp);
while ((sig = va_arg(ap, int)) != 0)
sigdelset(maskp, sig);
va_end(ap);
}
/*
* Log a message and sleep for a while (to give someone an opportunity
* to read it and to save log or hardcopy output if the problem is chronic).
* NB: should send a message to the session logger to avoid blocking.
*/
static void
stall(const char *message, ...)
{
va_list ap;
va_start(ap, message);
vsyslog(LOG_ALERT, message, ap);
va_end(ap);
sleep(STALL_TIMEOUT);
}
/*
* Like stall(), but doesn't sleep.
* If cpp had variadic macros, the two functions could be #defines for another.
* NB: should send a message to the session logger to avoid blocking.
*/
static void
warning(const char *message, ...)
{
va_list ap;
va_start(ap, message);
vsyslog(LOG_ALERT, message, ap);
va_end(ap);
}
/*
* Log an emergency message.
* NB: should send a message to the session logger to avoid blocking.
*/
static void
emergency(const char *message, ...)
{
va_list ap;
va_start(ap, message);
vsyslog(LOG_EMERG, message, ap);
va_end(ap);
}
/*
* Catch a SIGSYS signal.
*
* These may arise if a system does not support sysctl.
* We tolerate up to 25 of these, then throw in the towel.
*/
static void
badsys(int sig)
{
static int badcount = 0;
if (badcount++ < 25)
return;
disaster(sig);
}
/*
* Catch an unexpected signal.
*/
static void
disaster(int sig)
{
emergency("fatal signal: %s",
(unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal");
sleep(STALL_TIMEOUT);
_exit(sig); /* reboot */
}
/*
* Get the security level of the kernel.
*/
static int
getsecuritylevel(void)
{
#ifdef KERN_SECURELVL
int name[2], curlevel;
size_t len;
name[0] = CTL_KERN;
name[1] = KERN_SECURELVL;
len = sizeof curlevel;
if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) {
emergency("cannot get kernel security level: %s",
strerror(errno));
return (-1);
}
return (curlevel);
#else
return (-1);
#endif
}
/*
* Set the security level of the kernel.
*/
static void
setsecuritylevel(int newlevel)
{
#ifdef KERN_SECURELVL
int name[2], curlevel;
curlevel = getsecuritylevel();
if (newlevel == curlevel)
return;
name[0] = CTL_KERN;
name[1] = KERN_SECURELVL;
if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) {
emergency(
"cannot change kernel security level from %d to %d: %s",
curlevel, newlevel, strerror(errno));
return;
}
#ifdef SECURE
warning("kernel security level changed from %d to %d",
curlevel, newlevel);
#endif
#endif
}
/*
* Change states in the finite state machine.
* The initial state is passed as an argument.
*/
static void
transition(state_t s)
{
current_state = s;
for (;;)
current_state = (state_t) (*current_state)();
}
/*
* Close out the accounting files for a login session.
* NB: should send a message to the session logger to avoid blocking.
*/
static void
clear_session_logs(session_t *sp __unused)
{
/*
* XXX: Use getutxline() and call pututxline() for each entry.
* Is this safe to do this here? Is it really required anyway?
*/
}
/*
* Start a session and allocate a controlling terminal.
* Only called by children of init after forking.
*/
static void
setctty(const char *name)
{
int fd;
revoke(name);
if ((fd = open(name, O_RDWR)) == -1) {
stall("can't open %s: %m", name);
_exit(1);
}
if (login_tty(fd) == -1) {
stall("can't get %s for controlling terminal: %m", name);
_exit(1);
}
}
static const char *
get_shell(void)
{
static char kenv_value[PATH_MAX];
if (kenv(KENV_GET, "init_shell", kenv_value, sizeof(kenv_value)) > 0)
return kenv_value;
else
return _PATH_BSHELL;
}
static void
write_stderr(const char *message)
{
write(STDERR_FILENO, message, strlen(message));
}
/*
* Bring the system up single user.
*/
static state_func_t
single_user(void)
{
pid_t pid, wpid;
int status;
sigset_t mask;
const char *shell;
char *argv[2];
#ifdef SECURE
struct ttyent *typ;
struct passwd *pp;
static const char banner[] =
"Enter root password, or ^D to go multi-user\n";
char *clear, *password;
#endif
#ifdef DEBUGSHELL
char altshell[128];
#endif
if (Reboot) {
/* Instead of going single user, let's reboot the machine */
sync();
alarm(2);
pause();
reboot(howto);
_exit(0);
}
shell = get_shell();
if ((pid = fork()) == 0) {
/*
* Start the single user session.
*/
setctty(_PATH_CONSOLE);
#ifdef SECURE
/*
* Check the root password.
* We don't care if the console is 'on' by default;
* it's the only tty that can be 'off' and 'secure'.
*/
typ = getttynam("console");
pp = getpwnam("root");
if (typ && (typ->ty_status & TTY_SECURE) == 0 &&
pp && *pp->pw_passwd) {
write_stderr(banner);
for (;;) {
clear = getpass("Password:");
if (clear == 0 || *clear == '\0')
_exit(0);
password = crypt(clear, pp->pw_passwd);
bzero(clear, _PASSWORD_LEN);
if (strcmp(password, pp->pw_passwd) == 0)
break;
warning("single-user login failed\n");
}
}
endttyent();
endpwent();
#endif /* SECURE */
#ifdef DEBUGSHELL
{
char *cp = altshell;
int num;
#define SHREQUEST "Enter full pathname of shell or RETURN for "
write_stderr(SHREQUEST);
write_stderr(shell);
write_stderr(": ");
while ((num = read(STDIN_FILENO, cp, 1)) != -1 &&
num != 0 && *cp != '\n' && cp < &altshell[127])
cp++;
*cp = '\0';
if (altshell[0] != '\0')
shell = altshell;
}
#endif /* DEBUGSHELL */
/*
* Unblock signals.
* We catch all the interesting ones,
* and those are reset to SIG_DFL on exec.
*/
sigemptyset(&mask);
sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
/*
* Fire off a shell.
* If the default one doesn't work, try the Bourne shell.
*/
char name[] = "-sh";
argv[0] = name;
argv[1] = 0;
execv(shell, argv);
emergency("can't exec %s for single user: %m", shell);
execv(_PATH_BSHELL, argv);
emergency("can't exec %s for single user: %m", _PATH_BSHELL);
sleep(STALL_TIMEOUT);
_exit(1);
}
if (pid == -1) {
/*
* We are seriously hosed. Do our best.
*/
emergency("can't fork single-user shell, trying again");
while (waitpid(-1, (int *) 0, WNOHANG) > 0)
continue;
return (state_func_t) single_user;
}
requested_transition = 0;
do {
if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
collect_child(wpid);
if (wpid == -1) {
if (errno == EINTR)
continue;
warning("wait for single-user shell failed: %m; restarting");
return (state_func_t) single_user;
}
if (wpid == pid && WIFSTOPPED(status)) {
warning("init: shell stopped, restarting\n");
kill(pid, SIGCONT);
wpid = -1;
}
} while (wpid != pid && !requested_transition);
if (requested_transition)
return (state_func_t) requested_transition;
if (!WIFEXITED(status)) {
if (WTERMSIG(status) == SIGKILL) {
/*
* reboot(8) killed shell?
*/
warning("single user shell terminated.");
sleep(STALL_TIMEOUT);
_exit(0);
} else {
warning("single user shell terminated, restarting");
return (state_func_t) single_user;
}
}
runcom_mode = FASTBOOT;
return (state_func_t) runcom;
}
/*
* Run the system startup script.
*/
static state_func_t
runcom(void)
{
struct utmpx utx;
state_func_t next_transition;
if ((next_transition = run_script(_PATH_RUNCOM)) != 0)
return next_transition;
runcom_mode = AUTOBOOT; /* the default */
/* NB: should send a message to the session logger to avoid blocking. */
utx.ut_type = BOOT_TIME;
gettimeofday(&utx.ut_tv, NULL);
pututxline(&utx);
return (state_func_t) read_ttys;
}
/*
* Run a shell script.
* Returns 0 on success, otherwise the next transition to enter:
* - single_user if fork/execv/waitpid failed, or if the script
* terminated with a signal or exit code != 0.
* - death_single if a SIGTERM was delivered to init(8).
*/
static state_func_t
run_script(const char *script)
{
pid_t pid, wpid;
int status;
char *argv[4];
const char *shell;
struct sigaction sa;
shell = get_shell();
if ((pid = fork()) == 0) {
sigemptyset(&sa.sa_mask);
sa.sa_flags = 0;
sa.sa_handler = SIG_IGN;
sigaction(SIGTSTP, &sa, (struct sigaction *)0);
sigaction(SIGHUP, &sa, (struct sigaction *)0);
setctty(_PATH_CONSOLE);
char _sh[] = "sh";
char _autoboot[] = "autoboot";
argv[0] = _sh;
argv[1] = __DECONST(char *, script);
argv[2] = runcom_mode == AUTOBOOT ? _autoboot : 0;
argv[3] = 0;
sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0);
#ifdef LOGIN_CAP
setprocresources(RESOURCE_RC);
#endif
execv(shell, argv);
stall("can't exec %s for %s: %m", shell, script);
_exit(1); /* force single user mode */
}
if (pid == -1) {
emergency("can't fork for %s on %s: %m", shell, script);
while (waitpid(-1, (int *) 0, WNOHANG) > 0)
continue;
sleep(STALL_TIMEOUT);
return (state_func_t) single_user;
}
/*
* Copied from single_user(). This is a bit paranoid.
*/
requested_transition = 0;
do {
if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
collect_child(wpid);
if (wpid == -1) {
if (requested_transition == death_single)
return (state_func_t) death_single;
if (errno == EINTR)
continue;
warning("wait for %s on %s failed: %m; going to "
"single user mode", shell, script);
return (state_func_t) single_user;
}
if (wpid == pid && WIFSTOPPED(status)) {
warning("init: %s on %s stopped, restarting\n",
shell, script);
kill(pid, SIGCONT);
wpid = -1;
}
} while (wpid != pid);
if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
requested_transition == catatonia) {
/* /etc/rc executed /sbin/reboot; wait for the end quietly */
sigset_t s;
sigfillset(&s);
for (;;)
sigsuspend(&s);
}
if (!WIFEXITED(status)) {
warning("%s on %s terminated abnormally, going to single "
"user mode", shell, script);
return (state_func_t) single_user;
}
if (WEXITSTATUS(status))
return (state_func_t) single_user;
return (state_func_t) 0;
}
/*
* Open the session database.
*
* NB: We could pass in the size here; is it necessary?
*/
static int
start_session_db(void)
{
if (session_db && (*session_db->close)(session_db))
emergency("session database close: %s", strerror(errno));
if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == 0) {
emergency("session database open: %s", strerror(errno));
return (1);
}
return (0);
}
/*
* Add a new login session.
*/
static void
add_session(session_t *sp)
{
DBT key;
DBT data;
key.data = &sp->se_process;
key.size = sizeof sp->se_process;
data.data = &sp;
data.size = sizeof sp;
if ((*session_db->put)(session_db, &key, &data, 0))
emergency("insert %d: %s", sp->se_process, strerror(errno));
}
/*
* Delete an old login session.
*/
static void
del_session(session_t *sp)
{
DBT key;
key.data = &sp->se_process;
key.size = sizeof sp->se_process;
if ((*session_db->del)(session_db, &key, 0))
emergency("delete %d: %s", sp->se_process, strerror(errno));
}
/*
* Look up a login session by pid.
*/
static session_t *
find_session(pid_t pid)
{
DBT key;
DBT data;
session_t *ret;
key.data = &pid;
key.size = sizeof pid;
if ((*session_db->get)(session_db, &key, &data, 0) != 0)
return 0;
bcopy(data.data, (char *)&ret, sizeof(ret));
return ret;
}
/*
* Construct an argument vector from a command line.
*/
static char **
construct_argv(char *command)
{
int argc = 0;
char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1)
* sizeof (char *));
if ((argv[argc++] = strk(command)) == 0) {
free(argv);
return (NULL);
}
while ((argv[argc++] = strk((char *) 0)) != NULL)
continue;
return argv;
}
/*
* Deallocate a session descriptor.
*/
static void
free_session(session_t *sp)
{
free(sp->se_device);
if (sp->se_getty) {
free(sp->se_getty);
free(sp->se_getty_argv_space);
free(sp->se_getty_argv);
}
if (sp->se_window) {
free(sp->se_window);
free(sp->se_window_argv_space);
free(sp->se_window_argv);
}
if (sp->se_type)
free(sp->se_type);
free(sp);
}
/*
* Allocate a new session descriptor.
* Mark it SE_PRESENT.
*/
static session_t *
new_session(session_t *sprev, int session_index, struct ttyent *typ)
{
session_t *sp;
int fd;
if ((typ->ty_status & TTY_ON) == 0 ||
typ->ty_name == 0 ||
typ->ty_getty == 0)
return 0;
sp = (session_t *) calloc(1, sizeof (session_t));
sp->se_index = session_index;
sp->se_flags |= SE_PRESENT;
sp->se_device = malloc(sizeof(_PATH_DEV) + strlen(typ->ty_name));
sprintf(sp->se_device, "%s%s", _PATH_DEV, typ->ty_name);
/*
* Attempt to open the device, if we get "device not configured"
* then don't add the device to the session list.
*/
if ((fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0)) < 0) {
if (errno == ENXIO) {
free_session(sp);
return (0);
}
} else
close(fd);
if (setupargv(sp, typ) == 0) {
free_session(sp);
return (0);
}
sp->se_next = 0;
if (sprev == 0) {
sessions = sp;
sp->se_prev = 0;
} else {
sprev->se_next = sp;
sp->se_prev = sprev;
}
return sp;
}
/*
* Calculate getty and if useful window argv vectors.
*/
static int
setupargv(session_t *sp, struct ttyent *typ)
{
if (sp->se_getty) {
free(sp->se_getty);
free(sp->se_getty_argv_space);
free(sp->se_getty_argv);
}
sp->se_getty = malloc(strlen(typ->ty_getty) + strlen(typ->ty_name) + 2);
sprintf(sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name);
sp->se_getty_argv_space = strdup(sp->se_getty);
sp->se_getty_argv = construct_argv(sp->se_getty_argv_space);
if (sp->se_getty_argv == 0) {
warning("can't parse getty for port %s", sp->se_device);
free(sp->se_getty);
free(sp->se_getty_argv_space);
sp->se_getty = sp->se_getty_argv_space = 0;
return (0);
}
if (sp->se_window) {
free(sp->se_window);
free(sp->se_window_argv_space);
free(sp->se_window_argv);
}
sp->se_window = sp->se_window_argv_space = 0;
sp->se_window_argv = 0;
if (typ->ty_window) {
sp->se_window = strdup(typ->ty_window);
sp->se_window_argv_space = strdup(sp->se_window);
sp->se_window_argv = construct_argv(sp->se_window_argv_space);
if (sp->se_window_argv == 0) {
warning("can't parse window for port %s",
sp->se_device);
free(sp->se_window_argv_space);
free(sp->se_window);
sp->se_window = sp->se_window_argv_space = 0;
return (0);
}
}
if (sp->se_type)
free(sp->se_type);
sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0;
return (1);
}
/*
* Walk the list of ttys and create sessions for each active line.
*/
static state_func_t
read_ttys(void)
{
int session_index = 0;
session_t *sp, *snext;
struct ttyent *typ;
/*
* Destroy any previous session state.
* There shouldn't be any, but just in case...
*/
for (sp = sessions; sp; sp = snext) {
if (sp->se_process)
clear_session_logs(sp);
snext = sp->se_next;
free_session(sp);
}
sessions = 0;
if (start_session_db())
return (state_func_t) single_user;
/*
* Allocate a session entry for each active port.
* Note that sp starts at 0.
*/
while ((typ = getttyent()) != NULL)
if ((snext = new_session(sp, ++session_index, typ)) != NULL)
sp = snext;
endttyent();
return (state_func_t) multi_user;
}
/*
* Start a window system running.
*/
static void
start_window_system(session_t *sp)
{
pid_t pid;
sigset_t mask;
char term[64], *env[2];
int status;
if ((pid = fork()) == -1) {
emergency("can't fork for window system on port %s: %m",
sp->se_device);
/* hope that getty fails and we can try again */
return;
}
if (pid) {
waitpid(-1, &status, 0);
return;
}
/* reparent window process to the init to not make a zombie on exit */
if ((pid = fork()) == -1) {
emergency("can't fork for window system on port %s: %m",
sp->se_device);
_exit(1);
}
if (pid)
_exit(0);
sigemptyset(&mask);
sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
if (setsid() < 0)
emergency("setsid failed (window) %m");
#ifdef LOGIN_CAP
setprocresources(RESOURCE_WINDOW);
#endif
if (sp->se_type) {
/* Don't use malloc after fork */
strcpy(term, "TERM=");
strncat(term, sp->se_type, sizeof(term) - 6);
env[0] = term;
env[1] = 0;
}
else
env[0] = 0;
execve(sp->se_window_argv[0], sp->se_window_argv, env);
stall("can't exec window system '%s' for port %s: %m",
sp->se_window_argv[0], sp->se_device);
_exit(1);
}
/*
* Start a login session running.
*/
static pid_t
start_getty(session_t *sp)
{
pid_t pid;
sigset_t mask;
time_t current_time = time((time_t *) 0);
int too_quick = 0;
char term[64], *env[2];
if (current_time >= sp->se_started &&
current_time - sp->se_started < GETTY_SPACING) {
if (++sp->se_nspace > GETTY_NSPACE) {
sp->se_nspace = 0;
too_quick = 1;
}
} else
sp->se_nspace = 0;
/*
* fork(), not vfork() -- we can't afford to block.
*/
if ((pid = fork()) == -1) {
emergency("can't fork for getty on port %s: %m", sp->se_device);
return -1;
}
if (pid)
return pid;
if (too_quick) {
warning("getty repeating too quickly on port %s, sleeping %d secs",
sp->se_device, GETTY_SLEEP);
sleep((unsigned) GETTY_SLEEP);
}
if (sp->se_window) {
start_window_system(sp);
sleep(WINDOW_WAIT);
}
sigemptyset(&mask);
sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
#ifdef LOGIN_CAP
setprocresources(RESOURCE_GETTY);
#endif
if (sp->se_type) {
/* Don't use malloc after fork */
strcpy(term, "TERM=");
strncat(term, sp->se_type, sizeof(term) - 6);
env[0] = term;
env[1] = 0;
} else
env[0] = 0;
execve(sp->se_getty_argv[0], sp->se_getty_argv, env);
stall("can't exec getty '%s' for port %s: %m",
sp->se_getty_argv[0], sp->se_device);
_exit(1);
}
/*
* Collect exit status for a child.
* If an exiting login, start a new login running.
*/
static void
collect_child(pid_t pid)
{
session_t *sp, *sprev, *snext;
if (! sessions)
return;
if (! (sp = find_session(pid)))
return;
clear_session_logs(sp);
del_session(sp);
sp->se_process = 0;
if (sp->se_flags & SE_SHUTDOWN) {
if ((sprev = sp->se_prev) != NULL)
sprev->se_next = sp->se_next;
else
sessions = sp->se_next;
if ((snext = sp->se_next) != NULL)
snext->se_prev = sp->se_prev;
free_session(sp);
return;
}
if ((pid = start_getty(sp)) == -1) {
/* serious trouble */
requested_transition = clean_ttys;
return;
}
sp->se_process = pid;
sp->se_started = time((time_t *) 0);
add_session(sp);
}
/*
* Catch a signal and request a state transition.
*/
static void
transition_handler(int sig)
{
switch (sig) {
case SIGHUP:
if (current_state == read_ttys || current_state == multi_user ||
current_state == clean_ttys || current_state == catatonia)
requested_transition = clean_ttys;
break;
case SIGUSR2:
howto = RB_POWEROFF;
case SIGUSR1:
howto |= RB_HALT;
case SIGINT:
Reboot = TRUE;
case SIGTERM:
if (current_state == read_ttys || current_state == multi_user ||
current_state == clean_ttys || current_state == catatonia)
requested_transition = death;
else
requested_transition = death_single;
break;
case SIGTSTP:
if (current_state == runcom || current_state == read_ttys ||
current_state == clean_ttys ||
current_state == multi_user || current_state == catatonia)
requested_transition = catatonia;
break;
default:
requested_transition = 0;
break;
}
}
/*
* Take the system multiuser.
*/
static state_func_t
multi_user(void)
{
pid_t pid;
session_t *sp;
requested_transition = 0;
/*
* If the administrator has not set the security level to -1
* to indicate that the kernel should not run multiuser in secure
* mode, and the run script has not set a higher level of security
* than level 1, then put the kernel into secure mode.
*/
if (getsecuritylevel() == 0)
setsecuritylevel(1);
for (sp = sessions; sp; sp = sp->se_next) {
if (sp->se_process)
continue;
if ((pid = start_getty(sp)) == -1) {
/* serious trouble */
requested_transition = clean_ttys;
break;
}
sp->se_process = pid;
sp->se_started = time((time_t *) 0);
add_session(sp);
}
while (!requested_transition)
if ((pid = waitpid(-1, (int *) 0, 0)) != -1)
collect_child(pid);
return (state_func_t) requested_transition;
}
/*
* This is an (n*2)+(n^2) algorithm. We hope it isn't run often...
*/
static state_func_t
clean_ttys(void)
{
session_t *sp, *sprev;
struct ttyent *typ;
int session_index = 0;
int devlen;
char *old_getty, *old_window, *old_type;
/*
* mark all sessions for death, (!SE_PRESENT)
* as we find or create new ones they'll be marked as keepers,
* we'll later nuke all the ones not found in /etc/ttys
*/
for (sp = sessions; sp != NULL; sp = sp->se_next)
sp->se_flags &= ~SE_PRESENT;
devlen = sizeof(_PATH_DEV) - 1;
while ((typ = getttyent()) != NULL) {
++session_index;
for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next)
if (strcmp(typ->ty_name, sp->se_device + devlen) == 0)
break;
if (sp) {
/* we want this one to live */
sp->se_flags |= SE_PRESENT;
if (sp->se_index != session_index) {
warning("port %s changed utmp index from %d to %d",
sp->se_device, sp->se_index,
session_index);
sp->se_index = session_index;
}
if ((typ->ty_status & TTY_ON) == 0 ||
typ->ty_getty == 0) {
sp->se_flags |= SE_SHUTDOWN;
kill(sp->se_process, SIGHUP);
continue;
}
sp->se_flags &= ~SE_SHUTDOWN;
old_getty = sp->se_getty ? strdup(sp->se_getty) : 0;
old_window = sp->se_window ? strdup(sp->se_window) : 0;
old_type = sp->se_type ? strdup(sp->se_type) : 0;
if (setupargv(sp, typ) == 0) {
warning("can't parse getty for port %s",
sp->se_device);
sp->se_flags |= SE_SHUTDOWN;
kill(sp->se_process, SIGHUP);
}
else if ( !old_getty
|| (!old_type && sp->se_type)
|| (old_type && !sp->se_type)
|| (!old_window && sp->se_window)
|| (old_window && !sp->se_window)
|| (strcmp(old_getty, sp->se_getty) != 0)
|| (old_window && strcmp(old_window, sp->se_window) != 0)
|| (old_type && strcmp(old_type, sp->se_type) != 0)
) {
/* Don't set SE_SHUTDOWN here */
sp->se_nspace = 0;
sp->se_started = 0;
kill(sp->se_process, SIGHUP);
}
if (old_getty)
free(old_getty);
if (old_window)
free(old_window);
if (old_type)
free(old_type);
continue;
}
new_session(sprev, session_index, typ);
}
endttyent();
/*
* sweep through and kill all deleted sessions
* ones who's /etc/ttys line was deleted (SE_PRESENT unset)
*/
for (sp = sessions; sp != NULL; sp = sp->se_next) {
if ((sp->se_flags & SE_PRESENT) == 0) {
sp->se_flags |= SE_SHUTDOWN;
kill(sp->se_process, SIGHUP);
}
}
return (state_func_t) multi_user;
}
/*
* Block further logins.
*/
static state_func_t
catatonia(void)
{
session_t *sp;
for (sp = sessions; sp; sp = sp->se_next)
sp->se_flags |= SE_SHUTDOWN;
return (state_func_t) multi_user;
}
/*
* Note SIGALRM.
*/
static void
alrm_handler(int sig)
{
(void)sig;
clang = 1;
}
/*
* Bring the system down to single user.
*/
static state_func_t
death(void)
{
struct utmpx utx;
session_t *sp;
/* NB: should send a message to the session logger to avoid blocking. */
utx.ut_type = SHUTDOWN_TIME;
gettimeofday(&utx.ut_tv, NULL);
pututxline(&utx);
/*
* Also revoke the TTY here. Because runshutdown() may reopen
* the TTY whose getty we're killing here, there is no guarantee
* runshutdown() will perform the initial open() call, causing
* the terminal attributes to be misconfigured.
*/
for (sp = sessions; sp; sp = sp->se_next) {
sp->se_flags |= SE_SHUTDOWN;
kill(sp->se_process, SIGHUP);
revoke(sp->se_device);
}
/* Try to run the rc.shutdown script within a period of time */
runshutdown();
return (state_func_t) death_single;
}
/*
* Do what is necessary to reinitialize single user mode or reboot
* from an incomplete state.
*/
static state_func_t
death_single(void)
{
int i;
pid_t pid;
static const int death_sigs[2] = { SIGTERM, SIGKILL };
revoke(_PATH_CONSOLE);
for (i = 0; i < 2; ++i) {
if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH)
return (state_func_t) single_user;
clang = 0;
alarm(DEATH_WATCH);
do
if ((pid = waitpid(-1, (int *)0, 0)) != -1)
collect_child(pid);
while (clang == 0 && errno != ECHILD);
if (errno == ECHILD)
return (state_func_t) single_user;
}
warning("some processes would not die; ps axl advised");
return (state_func_t) single_user;
}
/*
* Run the system shutdown script.
*
* Exit codes: XXX I should document more
* -2 shutdown script terminated abnormally
* -1 fatal error - can't run script
* 0 good.
* >0 some error (exit code)
*/
static int
runshutdown(void)
{
pid_t pid, wpid;
int status;
int shutdowntimeout;
size_t len;
char *argv[4];
const char *shell;
struct sigaction sa;
struct stat sb;
/*
* rc.shutdown is optional, so to prevent any unnecessary
* complaints from the shell we simply don't run it if the
* file does not exist. If the stat() here fails for other
* reasons, we'll let the shell complain.
*/
if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT)
return 0;
shell = get_shell();
if ((pid = fork()) == 0) {
sigemptyset(&sa.sa_mask);
sa.sa_flags = 0;
sa.sa_handler = SIG_IGN;
sigaction(SIGTSTP, &sa, (struct sigaction *)0);
sigaction(SIGHUP, &sa, (struct sigaction *)0);
setctty(_PATH_CONSOLE);
char _sh[] = "sh";
char _reboot[] = "reboot";
char _single[] = "single";
char _path_rundown[] = _PATH_RUNDOWN;
argv[0] = _sh;
argv[1] = _path_rundown;
argv[2] = Reboot ? _reboot : _single;
argv[3] = 0;
sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0);
#ifdef LOGIN_CAP
setprocresources(RESOURCE_RC);
#endif
execv(shell, argv);
warning("can't exec %s for %s: %m", shell, _PATH_RUNDOWN);
_exit(1); /* force single user mode */
}
if (pid == -1) {
emergency("can't fork for %s on %s: %m", shell, _PATH_RUNDOWN);
while (waitpid(-1, (int *) 0, WNOHANG) > 0)
continue;
sleep(STALL_TIMEOUT);
return -1;
}
len = sizeof(shutdowntimeout);
if (sysctlbyname("kern.init_shutdown_timeout", &shutdowntimeout, &len,
NULL, 0) == -1 || shutdowntimeout < 2)
shutdowntimeout = DEATH_SCRIPT;
alarm(shutdowntimeout);
clang = 0;
/*
* Copied from single_user(). This is a bit paranoid.
* Use the same ALRM handler.
*/
do {
if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
collect_child(wpid);
if (clang == 1) {
/* we were waiting for the sub-shell */
kill(wpid, SIGTERM);
warning("timeout expired for %s on %s: %m; going to "
"single user mode", shell, _PATH_RUNDOWN);
return -1;
}
if (wpid == -1) {
if (errno == EINTR)
continue;
warning("wait for %s on %s failed: %m; going to "
"single user mode", shell, _PATH_RUNDOWN);
return -1;
}
if (wpid == pid && WIFSTOPPED(status)) {
warning("init: %s on %s stopped, restarting\n",
shell, _PATH_RUNDOWN);
kill(pid, SIGCONT);
wpid = -1;
}
} while (wpid != pid && !clang);
/* Turn off the alarm */
alarm(0);
if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
requested_transition == catatonia) {
/*
* /etc/rc.shutdown executed /sbin/reboot;
* wait for the end quietly
*/
sigset_t s;
sigfillset(&s);
for (;;)
sigsuspend(&s);
}
if (!WIFEXITED(status)) {
warning("%s on %s terminated abnormally, going to "
"single user mode", shell, _PATH_RUNDOWN);
return -2;
}
if ((status = WEXITSTATUS(status)) != 0)
warning("%s returned status %d", _PATH_RUNDOWN, status);
return status;
}
static char *
strk(char *p)
{
static char *t;
char *q;
int c;
if (p)
t = p;
if (!t)
return 0;
c = *t;
while (c == ' ' || c == '\t' )
c = *++t;
if (!c) {
t = 0;
return 0;
}
q = t;
if (c == '\'') {
c = *++t;
q = t;
while (c && c != '\'')
c = *++t;
if (!c) /* unterminated string */
q = t = 0;
else
*t++ = 0;
} else {
while (c && c != ' ' && c != '\t' )
c = *++t;
*t++ = 0;
if (!c)
t = 0;
}
return q;
}
#ifdef LOGIN_CAP
static void
setprocresources(const char *cname)
{
login_cap_t *lc;
if ((lc = login_getclassbyname(cname, NULL)) != NULL) {
setusercontext(lc, (struct passwd*)NULL, 0,
LOGIN_SETPRIORITY | LOGIN_SETRESOURCES);
login_close(lc);
}
}
#endif