OpenBSD-4.6/sbin/init/init.c
/* $OpenBSD: init.c,v 1.40 2007/09/03 14:26:54 deraadt Exp $ */
/* $NetBSD: init.c,v 1.22 1996/05/15 23:29:33 jtc Exp $ */
/*-
* 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.
* 3. 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 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 8.2 (Berkeley) 4/28/95";
#else
static char rcsid[] = "$OpenBSD: init.c,v 1.40 2007/09/03 14:26:54 deraadt Exp $";
#endif
#endif /* not lint */
#include <sys/param.h>
#include <sys/sysctl.h>
#include <sys/wait.h>
#include <sys/reboot.h>
#include <db.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <time.h>
#include <ttyent.h>
#include <unistd.h>
#include <util.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 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 */
/*
* User-based resource limits.
*/
#define RESOURCE_RC "daemon"
#define RESOURCE_WINDOW "default"
#define RESOURCE_GETTY "default"
#ifndef DEFAULT_STATE
#define DEFAULT_STATE runcom
#endif
void handle(sig_t, ...);
void delset(sigset_t *, ...);
void stall(char *, ...);
void warning(char *, ...);
void emergency(char *, ...);
void disaster(int);
void badsys(int);
/*
* 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);
state_func_t single_user(void);
state_func_t runcom(void);
state_func_t read_ttys(void);
state_func_t multi_user(void);
state_func_t clean_ttys(void);
state_func_t catatonia(void);
state_func_t death(void);
state_func_t hard_death(void);
state_func_t nice_death(void);
enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT;
void transition(state_t);
state_t requested_transition = DEFAULT_STATE;
void setctty(char *);
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 */
#define SE_DEVEXISTS 0x4 /* open does not result in ENODEV */
char *se_device; /* filename of port */
char *se_getty; /* what to run on that port */
char **se_getty_argv; /* pre-parsed argument array */
char *se_window; /* window system (started only once) */
char **se_window_argv; /* pre-parsed argument array */
struct init_session *se_prev;
struct init_session *se_next;
} session_t;
void free_session(session_t *);
session_t *new_session(session_t *, int, struct ttyent *);
session_t *sessions;
char **construct_argv(char *);
void start_window_system(session_t *);
void collect_child(pid_t);
pid_t start_getty(session_t *);
void transition_handler(int);
void alrm_handler(int);
void setsecuritylevel(int);
int getsecuritylevel(void);
int setupargv(session_t *, struct ttyent *);
int clang;
#ifdef LOGIN_CAP
void setprocresources(char *);
#else
#define setprocresources(p)
#endif
void clear_session_logs(session_t *);
int start_session_db(void);
void add_session(session_t *);
void del_session(session_t *);
session_t *find_session(pid_t);
DB *session_db;
/*
* The mother of all processes.
*/
int
main(int argc, char *argv[])
{
int c;
struct sigaction sa;
sigset_t mask;
/* Dispose of random users. */
if (getuid() != 0) {
(void)fprintf(stderr, "init: %s\n", strerror(EPERM));
exit (1);
}
/* System V users like to reexec init. */
if (getpid() != 1) {
(void)fprintf(stderr, "init: already running\n");
exit (1);
}
/*
* 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, "sf")) != -1)
switch (c) {
case 's':
requested_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, SIGTERM, SIGTSTP, SIGUSR1,
SIGUSR2, 0);
handle(alrm_handler, SIGALRM, 0);
sigfillset(&mask);
delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS,
SIGXCPU, SIGXFSZ, SIGHUP, SIGTERM, SIGUSR1, SIGUSR2,
SIGTSTP, SIGALRM, 0);
sigprocmask(SIG_SETMASK, &mask, NULL);
memset(&sa, 0, sizeof sa);
sigemptyset(&sa.sa_mask);
sa.sa_flags = 0;
sa.sa_handler = SIG_IGN;
(void) sigaction(SIGTTIN, &sa, NULL);
(void) sigaction(SIGTTOU, &sa, NULL);
/*
* Paranoia.
*/
close(STDIN_FILENO);
close(STDOUT_FILENO);
close(STDERR_FILENO);
/*
* Start the state machine.
*/
transition(requested_transition);
/*
* Should never reach here.
*/
exit(1);
}
/*
* Associate a function with a signal handler.
*/
void
handle(sig_t handler, ...)
{
int sig;
struct sigaction sa;
sigset_t mask_everything;
va_list ap;
va_start(ap, handler);
memset(&sa, 0, sizeof sa);
sa.sa_handler = handler;
sigfillset(&mask_everything);
while ((sig = va_arg(ap, int))) {
sa.sa_mask = mask_everything;
/* XXX SA_RESTART? */
sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0;
sigaction(sig, &sa, NULL);
}
va_end(ap);
}
/*
* Delete a set of signals from a mask.
*/
void
delset(sigset_t *maskp, ...)
{
int sig;
va_list ap;
va_start(ap, maskp);
while ((sig = va_arg(ap, int)))
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.
*/
void
stall(char *message, ...)
{
va_list ap;
va_start(ap, message);
vsyslog(LOG_ALERT, message, ap);
va_end(ap);
closelog();
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.
*/
void
warning(char *message, ...)
{
va_list ap;
va_start(ap, message);
vsyslog(LOG_ALERT, message, ap);
va_end(ap);
closelog();
}
/*
* Log an emergency message.
* NB: should send a message to the session logger to avoid blocking.
*/
void
emergency(char *message, ...)
{
struct syslog_data sdata = SYSLOG_DATA_INIT;
va_list ap;
va_start(ap, message);
vsyslog_r(LOG_EMERG, &sdata, 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.
*/
void
badsys(int sig)
{
static int badcount = 0;
if (badcount++ < 25)
return;
disaster(sig);
}
/*
* Catch an unexpected signal.
*/
void
disaster(int sig)
{
emergency("fatal signal: %s", strsignal(sig));
sleep(STALL_TIMEOUT);
_exit(sig); /* reboot */
}
/*
* Get the security level of the kernel.
*/
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.
*/
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.
*/
void
transition(state_t s)
{
for (;;)
s = (state_t) (*s)();
}
/*
* Close out the accounting files for a login session.
* NB: should send a message to the session logger to avoid blocking.
*/
void
clear_session_logs(session_t *sp)
{
char *line = sp->se_device + sizeof(_PATH_DEV) - 1;
if (logout(line))
logwtmp(line, "", "");
}
/*
* Start a session and allocate a controlling terminal.
* Only called by children of init after forking.
*/
void
setctty(char *name)
{
int fd;
(void) revoke(name);
sleep(2); /* leave DTR low */
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);
}
}
/*
* Bring the system up single user.
*/
state_func_t
single_user(void)
{
pid_t pid, wpid;
int status;
sigset_t mask;
char shell[MAXPATHLEN]; /* Allocate space here */
char name[MAXPATHLEN]; /* Name (argv[0]) of 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
/* Init shell and name */
strlcpy(shell, _PATH_BSHELL, sizeof shell);
strlcpy(name, "-sh", sizeof name);
/*
* If the kernel is in secure mode, downgrade it to insecure mode.
*/
if (getsecuritylevel() > 0)
setsecuritylevel(0);
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_FILENO, banner, sizeof banner - 1);
for (;;) {
clear = getpass("Password:");
if (clear == 0 || *clear == '\0')
_exit(0);
password = crypt(clear, pp->pw_passwd);
memset(clear, 0, _PASSWORD_LEN);
if (strcmp(password, pp->pw_passwd) == 0)
break;
warning("single-user login failed\n");
}
}
endttyent();
endpwent();
#endif /* SECURE */
#ifdef DEBUGSHELL
{
char altshell[128], *cp = altshell;
int num;
#define SHREQUEST \
"Enter pathname of shell or RETURN for sh: "
(void)write(STDERR_FILENO,
SHREQUEST, sizeof(SHREQUEST) - 1);
while ((num = read(STDIN_FILENO, cp, 1)) != -1 &&
num != 0 && *cp != '\n' && cp < &altshell[127])
cp++;
*cp = '\0';
/* Copy in alternate shell */
if (altshell[0] != '\0'){
char *p;
/* Binary to exec */
strlcpy(shell, altshell, sizeof shell);
/* argv[0] */
p = strrchr(altshell, '/');
if(p == NULL) p = altshell;
else p++;
name[0] = '-';
strlcpy(&name[1], p, sizeof name -1);
}
}
#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, NULL);
/*
* Fire off a shell.
* If the default one doesn't work, try the Bourne shell.
*/
argv[0] = name;
argv[1] = NULL;
setenv("PATH", _PATH_STDPATH, 1);
execv(shell, argv);
emergency("can't exec %s for single user: %m", shell);
argv[0] = "-sh";
argv[1] = NULL;
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, NULL, 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.
*/
state_func_t
runcom(void)
{
pid_t pid, wpid;
int status;
char *argv[4];
struct sigaction sa;
if ((pid = fork()) == 0) {
memset(&sa, 0, sizeof sa);
sigemptyset(&sa.sa_mask);
sa.sa_flags = 0;
sa.sa_handler = SIG_IGN;
(void) sigaction(SIGTSTP, &sa, NULL);
(void) sigaction(SIGHUP, &sa, NULL);
setctty(_PATH_CONSOLE);
argv[0] = "sh";
argv[1] = _PATH_RUNCOM;
argv[2] = runcom_mode == AUTOBOOT ? "autoboot" : 0;
argv[3] = 0;
sigprocmask(SIG_SETMASK, &sa.sa_mask, NULL);
setprocresources(RESOURCE_RC);
execv(_PATH_BSHELL, argv);
stall("can't exec %s for %s: %m", _PATH_BSHELL, _PATH_RUNCOM);
_exit(1); /* force single user mode */
}
if (pid == -1) {
emergency("can't fork for %s on %s: %m",
_PATH_BSHELL, _PATH_RUNCOM);
while (waitpid(-1, NULL, WNOHANG) > 0)
continue;
sleep(STALL_TIMEOUT);
return (state_func_t) single_user;
}
/*
* Copied from single_user(). This is a bit paranoid.
*/
do {
if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
collect_child(wpid);
if (wpid == -1) {
if (errno == EINTR)
continue;
warning("wait for %s on %s failed: %m; going to single user mode",
_PATH_BSHELL, _PATH_RUNCOM);
return (state_func_t) single_user;
}
if (wpid == pid && WIFSTOPPED(status)) {
warning("init: %s on %s stopped, restarting\n",
_PATH_BSHELL, _PATH_RUNCOM);
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",
_PATH_BSHELL, _PATH_RUNCOM);
return (state_func_t) single_user;
}
if (WEXITSTATUS(status))
return (state_func_t) single_user;
runcom_mode = AUTOBOOT; /* the default */
/* NB: should send a message to the session logger to avoid blocking. */
logwtmp("~", "reboot", "");
return (state_func_t) read_ttys;
}
/*
* Open the session database.
*
* NB: We could pass in the size here; is it necessary?
*/
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.
*/
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.
*/
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.
*/
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);
memcpy(&ret, data.data, sizeof(ret));
return (ret);
}
/*
* Construct an argument vector from a command line.
*/
char **
construct_argv(char *command)
{
int argc = 0;
char **argv = (char **) calloc((strlen(command) + 1) / 2 + 1,
sizeof (char *));
static const char separators[] = " \t";
if (argv == NULL)
return (0);
if ((argv[argc++] = strtok(command, separators)) == 0) {
free(argv);
return (0);
}
while ((argv[argc++] = strtok(NULL, separators)))
continue;
return (argv);
}
/*
* Deallocate a session descriptor.
*/
void
free_session(session_t *sp)
{
free(sp->se_device);
if (sp->se_getty) {
free(sp->se_getty);
free(sp->se_getty_argv);
}
if (sp->se_window) {
free(sp->se_window);
free(sp->se_window_argv);
}
free(sp);
}
/*
* Allocate a new session descriptor.
*/
session_t *
new_session(session_t *sprev, int session_index, struct ttyent *typ)
{
session_t *sp;
if ((typ->ty_status & TTY_ON) == 0 ||
typ->ty_name == 0 ||
typ->ty_getty == 0)
return (0);
sp = (session_t *) malloc(sizeof (session_t));
memset(sp, 0, sizeof *sp);
sp->se_flags = SE_PRESENT;
sp->se_index = session_index;
if (asprintf(&sp->se_device, "%s%s", _PATH_DEV, typ->ty_name) == -1)
err(1, "asprintf");
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.
*/
int
setupargv(session_t *sp, struct ttyent *typ)
{
if (sp->se_getty) {
free(sp->se_getty);
free(sp->se_getty_argv);
}
if (asprintf(&sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name) == -1)
err(1, "asprintf");
sp->se_getty_argv = construct_argv(sp->se_getty);
if (sp->se_getty_argv == 0) {
warning("can't parse getty for port %s", sp->se_device);
free(sp->se_getty);
sp->se_getty = 0;
return (0);
}
if (typ->ty_window) {
if (sp->se_window)
free(sp->se_window);
sp->se_window = strdup(typ->ty_window);
if (sp->se_window == NULL) {
warning("can't allocate window");
return (0);
}
sp->se_window_argv = construct_argv(sp->se_window);
if (sp->se_window_argv == NULL) {
warning("can't parse window for port %s",
sp->se_device);
free(sp->se_window);
sp->se_window = NULL;
return (0);
}
}
return (1);
}
/*
* Walk the list of ttys and create sessions for each active line.
*/
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()))
if ((snext = new_session(sp, ++session_index, typ)))
sp = snext;
endttyent();
return (state_func_t) multi_user;
}
/*
* Start a window system running.
*/
void
start_window_system(session_t *sp)
{
pid_t pid;
sigset_t mask;
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)
return;
sigemptyset(&mask);
sigprocmask(SIG_SETMASK, &mask, NULL);
if (setsid() < 0)
emergency("setsid failed (window) %m");
setprocresources(RESOURCE_WINDOW);
execv(sp->se_window_argv[0], sp->se_window_argv);
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.
* For first open, man-handle tty directly to determine if it
* really exists. It is not efficient to spawn gettys on devices
* that do not exist.
*/
pid_t
start_getty(session_t *sp)
{
pid_t pid;
sigset_t mask;
time_t current_time = time(NULL);
int p[2], new = 1;
if (sp->se_flags & SE_DEVEXISTS)
new = 0;
if (new) {
if (pipe(p) == -1)
return (-1);
}
/*
* 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) {
if (new) {
char c;
close(p[1]);
if (read(p[0], &c, 1) != 1) {
close(p[0]);
return (-1);
}
close(p[0]);
if (c == '1')
sp->se_flags |= SE_DEVEXISTS;
else
sp->se_flags |= SE_SHUTDOWN;
}
return (pid);
}
if (new) {
int fd;
close(p[0]);
fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0666);
if (fd == -1 && (errno == ENXIO || errno == ENOENT ||
errno == EISDIR)) {
(void)write(p[1], "0", 1);
close(p[1]);
_exit(1);
}
(void)write(p[1], "1", 1);
close(p[1]);
close(fd);
sleep(1);
}
if (current_time > sp->se_started &&
current_time - sp->se_started < GETTY_SPACING) {
warning("getty repeating too quickly on port %s, sleeping",
sp->se_device);
sleep((unsigned) GETTY_SLEEP);
}
if (sp->se_window) {
start_window_system(sp);
sleep(WINDOW_WAIT);
}
sigemptyset(&mask);
sigprocmask(SIG_SETMASK, &mask, NULL);
setprocresources(RESOURCE_GETTY);
execv(sp->se_getty_argv[0], sp->se_getty_argv);
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.
*/
void
collect_child(pid_t pid)
{
session_t *sp, *sprev, *snext;
if (sessions == NULL)
return;
if ((sp = find_session(pid)) == NULL)
return;
clear_session_logs(sp);
login_fbtab(sp->se_device + sizeof(_PATH_DEV) - 1, 0, 0);
del_session(sp);
sp->se_process = 0;
if (sp->se_flags & SE_SHUTDOWN) {
if ((sprev = sp->se_prev))
sprev->se_next = sp->se_next;
else
sessions = sp->se_next;
if ((snext = sp->se_next))
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(NULL);
add_session(sp);
}
/*
* Catch a signal and request a state transition.
*/
void
transition_handler(int sig)
{
switch (sig) {
case SIGHUP:
requested_transition = clean_ttys;
break;
case SIGTERM:
requested_transition = death;
break;
case SIGUSR1:
requested_transition = nice_death;
break;
case SIGUSR2:
requested_transition = hard_death;
break;
case SIGTSTP:
requested_transition = catatonia;
break;
default:
requested_transition = 0;
break;
}
}
/*
* Take the system multiuser.
*/
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(NULL);
add_session(sp);
}
while (!requested_transition)
if ((pid = waitpid(-1, NULL, 0)) != -1)
collect_child(pid);
return (state_func_t) requested_transition;
}
/*
* This is an n-squared algorithm. We hope it isn't run often...
*/
state_func_t
clean_ttys(void)
{
session_t *sp, *sprev;
struct ttyent *typ;
int session_index = 0;
int devlen;
for (sp = sessions; sp; sp = sp->se_next)
sp->se_flags &= ~SE_PRESENT;
devlen = sizeof(_PATH_DEV) - 1;
while ((typ = getttyent())) {
++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) {
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;
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);
}
continue;
}
new_session(sprev, session_index, typ);
}
endttyent();
for (sp = sessions; sp; 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.
*/
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.
*/
void
alrm_handler(int sig)
{
clang = 1;
}
int death_howto = RB_HALT;
/*
* Bring the system down nicely, then we must powerdown because something
* is very wrong.
*/
state_func_t
hard_death(void)
{
death_howto |= RB_POWERDOWN;
return nice_death();
}
/*
* Bring the system down to single user nicely, after run the shutdown script.
*/
state_func_t
nice_death(void)
{
session_t *sp;
int i;
pid_t pid;
static const int death_sigs[3] = { SIGHUP, SIGTERM, SIGKILL };
int status;
for (sp = sessions; sp; sp = sp->se_next) {
sp->se_flags &= ~SE_PRESENT;
sp->se_flags |= SE_SHUTDOWN;
kill(sp->se_process, SIGHUP);
}
/* terminate the accounting process */
acct(NULL);
/* NB: should send a message to the session logger to avoid blocking. */
logwtmp("~", "shutdown", "");
if (access(_PATH_RUNCOM, R_OK) != -1) {
pid_t pid;
struct sigaction sa;
switch ((pid = fork())) {
case -1:
break;
case 0:
memset(&sa, 0, sizeof sa);
sigemptyset(&sa.sa_mask);
sa.sa_flags = 0;
sa.sa_handler = SIG_IGN;
(void) sigaction(SIGTSTP, &sa, NULL);
(void) sigaction(SIGHUP, &sa, NULL);
setctty(_PATH_CONSOLE);
sigprocmask(SIG_SETMASK, &sa.sa_mask, NULL);
execl(_PATH_BSHELL, "sh", _PATH_RUNCOM, "shutdown",
(char *)NULL);
stall("can't exec %s for %s %s: %m", _PATH_BSHELL,
_PATH_RUNCOM, "shutdown");
_exit(1);
default:
waitpid(pid, &status, 0);
if (WIFEXITED(status) && WEXITSTATUS(status) == 2)
death_howto |= RB_POWERDOWN;
}
}
for (i = 0; i < 3; ++i) {
if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH)
goto die;
clang = 0;
alarm(DEATH_WATCH);
do {
if ((pid = waitpid(-1, NULL, 0)) != -1)
collect_child(pid);
} while (clang == 0 && errno != ECHILD);
if (errno == ECHILD)
goto die;
}
warning("some processes would not die; ps axl advised");
die:
reboot(death_howto);
/* ... and if that fails.. oh well */
return (state_func_t) single_user;
}
/*
* Bring the system down to single user.
*/
state_func_t
death(void)
{
session_t *sp;
int i;
pid_t pid;
static const int death_sigs[3] = { SIGHUP, SIGTERM, SIGKILL };
/* terminate the accounting process */
acct(NULL);
for (sp = sessions; sp; sp = sp->se_next)
sp->se_flags |= SE_SHUTDOWN;
/* NB: should send a message to the session logger to avoid blocking. */
logwtmp("~", "shutdown", "");
for (i = 0; i < 3; ++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, NULL, 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;
}
#ifdef LOGIN_CAP
void
setprocresources(char *class)
{
login_cap_t *lc;
if ((lc = login_getclass(class)) != NULL) {
setusercontext(lc, NULL, 0,
LOGIN_SETPRIORITY|LOGIN_SETRESOURCES|LOGIN_SETUMASK);
login_close(lc);
}
}
#endif