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/* $NetBSD: init.c,v 1.109 2021/10/11 20:23:25 jmcneill 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.
*/
#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1991, 1993\
The Regents of the University of California. All rights reserved.");
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)init.c 8.2 (Berkeley) 4/28/95";
#else
__RCSID("$NetBSD: init.c,v 1.109 2021/10/11 20:23:25 jmcneill Exp $");
#endif
#endif /* not lint */
#include <sys/param.h>
#include <sys/sysctl.h>
#include <sys/wait.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/mount.h>
#include <machine/cpu.h>
#include <db.h>
#include <errno.h>
#include <fcntl.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 <util.h>
#include <paths.h>
#include <err.h>
#ifdef SUPPORT_UTMP
#include <utmp.h>
#endif
#ifdef SUPPORT_UTMPX
#include <utmpx.h>
#endif
#include <stdarg.h>
#ifdef SECURE
#include <pwd.h>
#endif
#include "pathnames.h"
#define XSTR(x) #x
#define STR(x) XSTR(x)
/*
* 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 5 /* N retries before 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 */
static const struct timespec dtrtime = {.tv_sec = 0, .tv_nsec = 250000};
#if defined(RESCUEDIR)
#define INIT_BSHELL RESCUEDIR "/sh"
#define INIT_MOUNT_MFS RESCUEDIR "/mount_mfs"
#define INIT_PATH RESCUEDIR ":" _PATH_STDPATH
#else
#define INIT_BSHELL _PATH_BSHELL
#define INIT_MOUNT_MFS "/sbin/mount_mfs"
#define INIT_PATH _PATH_STDPATH
#endif
static void handle(sig_t, ...);
static void delset(sigset_t *, ...);
static void stall(const char *, ...) __sysloglike(1, 2);
static void warning(const char *, ...) __sysloglike(1, 2);
static void emergency(const char *, ...) __sysloglike(1, 2);
__dead static void disaster(int);
static 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);
#define DEATH 'd'
#define SINGLE_USER 's'
#define RUNCOM 'r'
#define READ_TTYS 't'
#define MULTI_USER 'm'
#define CLEAN_TTYS 'T'
#define CATATONIA 'c'
static state_func_t single_user(void);
#ifndef LETS_GET_SMALL
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);
#endif
static enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT;
static void transition(state_t);
static void setctty(const char *);
typedef struct init_session {
int se_index; /* index of entry in ttys file */
pid_t se_process; /* controlling process */
struct timeval se_started; /* used to avoid thrashing */
int se_nspace; /* spacing count */
int se_flags; /* status of session */
#define SE_SHUTDOWN 0x1 /* session won't be restarted */
#define SE_PRESENT 0x2 /* session is in /etc/ttys */
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;
static void collect_child(pid_t, int);
static int clang;
static void transition_handler(int);
static void alrm_handler(int);
static int has_securelevel(void);
static int securelevel_present;
#ifndef LETS_GET_SMALL
static int do_setttyent(void);
static void start_window_system(session_t *);
static char **construct_argv(char *);
static int setupargv(session_t *, struct ttyent *);
static pid_t start_getty(session_t *);
static void free_session(session_t *);
static session_t *new_session(session_t *, int, struct ttyent *);
static session_t *sessions;
static void setsecuritylevel(int);
static int getsecuritylevel(void);
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;
static state_t requested_transition = runcom;
static void clear_session_logs(session_t *, int);
static state_func_t runetcrc(int);
#ifdef SUPPORT_UTMPX
static struct timeval boot_time;
static state_t current_state = death;
static void session_utmpx(const session_t *, int);
static void make_utmpx(const char *, const char *, int, pid_t,
const struct timeval *, int);
static char get_runlevel(const state_t);
static void utmpx_set_runlevel(char, char);
#endif
#ifdef CHROOT
static int did_multiuser_chroot = 0;
static char rootdir[PATH_MAX];
static int shouldchroot(void);
static int createsysctlnode(void);
#endif /* CHROOT */
#else /* LETS_GET_SMALL */
static state_t requested_transition = single_user;
#endif /* !LETS_GET_SMALL */
#ifdef MFS_DEV_IF_NO_CONSOLE
static int mfs_dev(void);
#endif
/*
* The mother of all processes.
*/
int
main(int argc, char **argv)
{
struct sigaction sa;
sigset_t mask;
#ifndef LETS_GET_SMALL
int c;
#ifdef SUPPORT_UTMPX
(void)gettimeofday(&boot_time, NULL);
#endif /* SUPPORT_UTMPX */
/* Dispose of random users. */
if (getuid() != 0) {
errno = EPERM;
err(1, NULL);
}
/* System V users like to reexec init. */
if (getpid() != 1)
errx(1, "already running");
#endif
/*
* Create an initial session.
*/
if (setsid() < 0)
warn("initial setsid() failed");
/*
* Establish an initial user so that programs running
* single user do not freak out and die (like passwd).
*/
if (setlogin("root") < 0)
warn("setlogin() failed");
#ifdef MFS_DEV_IF_NO_CONSOLE
if (mfs_dev() == -1)
requested_transition = single_user;
#endif
#ifndef LETS_GET_SMALL
/*
* Note that this does NOT open a file...
* Does 'init' deserve its own facility number?
*/
openlog("init", LOG_CONS, LOG_AUTH);
#endif /* LETS_GET_SMALL */
#ifndef LETS_GET_SMALL
/*
* 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");
#else /* LETS_GET_SMALL */
requested_transition = single_user;
#endif /* LETS_GET_SMALL */
/*
* 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, 0);
handle(alrm_handler, SIGALRM, 0);
(void)sigfillset(&mask);
delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS,
SIGXCPU, SIGXFSZ, SIGHUP, SIGTERM, SIGTSTP, SIGALRM, 0);
(void)sigprocmask(SIG_SETMASK, &mask, NULL);
(void)sigemptyset(&sa.sa_mask);
sa.sa_flags = 0;
sa.sa_handler = SIG_IGN;
(void)sigaction(SIGTTIN, &sa, NULL);
(void)sigaction(SIGTTOU, &sa, NULL);
/*
* Paranoia.
*/
(void)close(0);
(void)close(1);
(void)close(2);
#if !defined(LETS_GET_SMALL) && defined(CHROOT)
/* Create "init.root" sysctl node. */
(void)createsysctlnode();
#endif /* !LETS_GET_SMALL && CHROOT*/
/*
* Securelevel might not be supported by the kernel. Query for it, and
* set a variable indicating whether we should attempt anything with it
* or not.
*/
securelevel_present = has_securelevel();
/*
* Start the state machine.
*/
transition(requested_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;
(void)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;
(void)sigaction(sig, &sa, NULL);
}
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)
(void)sigdelset(maskp, sig);
va_end(ap);
}
#if 0 /* Enable to get error messages from init ! */
#define vsyslog(level, fmt, ap) print_console(level, fmt, ap)
#define closelog()
static void
print_console(int level, const char *message, va_list ap)
{
/*
* XXX: syslog seems to just plain not work in console-only
* XXX: situation... that should be fixed. Let's leave this
* XXX: note + code here in case someone gets in trouble and
* XXX: wants to debug. -- Jachym Holecek <freza@liberouter.org>
*/
char errbuf[1024];
int fd, len;
/* We can't do anything on errors, anyway... */
fd = open(_PATH_CONSOLE, O_WRONLY);
if (fd == -1)
return ;
/* %m will get lost... */
len = vsnprintf(errbuf, sizeof(errbuf), message, ap);
(void)write(fd, (void *)errbuf, len);
(void)close(fd);
}
#endif
/*
* 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);
closelog();
(void)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);
closelog();
}
/*
* 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);
closelog();
}
/*
* 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", strsignal(sig));
(void)sleep(STALL_TIMEOUT);
_exit(sig); /* reboot */
}
/*
* Check if securelevel is present.
*/
static int
has_securelevel(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) {
/* If it doesn't exist, it's okay. */
if (errno == ENOENT)
return 0;
}
return 1;
#else
return 0;
#endif
}
/*
* Get the security level of the kernel.
*/
static int
getsecuritylevel(void)
{
#ifdef KERN_SECURELVL
int name[2], curlevel;
size_t len;
if (!securelevel_present)
return -1;
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: %m");
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;
if (!securelevel_present)
return;
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: %m", curlevel, newlevel);
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)
{
if (s == NULL)
return;
for (;;) {
#ifdef SUPPORT_UTMPX
#ifndef LETS_GET_SMALL
utmpx_set_runlevel(get_runlevel(current_state),
get_runlevel(s));
current_state = s;
#endif
#endif
s = (state_t)(*s)();
}
}
#ifndef LETS_GET_SMALL
/*
* 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, int status)
{
#if defined(SUPPORT_UTMP) || defined(SUPPORT_UTMPX)
char *line = sp->se_device + sizeof(_PATH_DEV) - 1;
#endif
#ifdef SUPPORT_UTMPX
if (logoutx(line, status, DEAD_PROCESS))
logwtmpx(line, "", "", status, DEAD_PROCESS);
#endif
#ifdef SUPPORT_UTMP
if (logout(line))
logwtmp(line, "", "");
#endif
}
#endif
/*
* Start a session and allocate a controlling terminal.
* Only called by children of init after forking.
*/
static void
setctty(const char *name)
{
int fd;
(void)revoke(name);
(void)nanosleep(&dtrtime, NULL); /* leave DTR low for a bit */
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(2);
}
}
/*
* Bring the system up single user.
*/
static state_func_t
single_user(void)
{
pid_t pid, wpid;
int status;
int from_securitylevel;
sigset_t mask;
struct sigaction sa, satstp, sahup;
#ifdef ALTSHELL
const char *shell = INIT_BSHELL;
#endif
const char *argv[2];
#ifdef SECURE
struct ttyent *typ;
struct passwd *pp;
char *clear, *password;
#endif
#ifdef ALTSHELL
char altshell[128];
#endif /* ALTSHELL */
#if !defined(LETS_GET_SMALL) && defined(CHROOT)
/* Clear previous idea, just in case. */
did_multiuser_chroot = 0;
#endif /* !LETS_GET_SMALL && CHROOT */
/*
* If the kernel is in secure mode, downgrade it to insecure mode.
*/
from_securitylevel = getsecuritylevel();
if (from_securitylevel > 0)
setsecuritylevel(0);
(void)sigemptyset(&sa.sa_mask);
sa.sa_flags = 0;
sa.sa_handler = SIG_IGN;
(void)sigaction(SIGTSTP, &sa, &satstp);
(void)sigaction(SIGHUP, &sa, &sahup);
if ((pid = fork()) == 0) {
/*
* Start the single user session.
*/
if (access(_PATH_CONSTTY, F_OK) == 0)
setctty(_PATH_CONSTTY);
else
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 && (from_securitylevel >=2 || (typ->ty_status
& TTY_SECURE) == 0) && pp && *pp->pw_passwd != '\0') {
(void)fprintf(stderr,
"Enter root password, or ^D to go multi-user\n");
for (;;) {
clear = getpass("Password:");
if (clear == 0 || *clear == '\0')
_exit(0);
password = crypt(clear, pp->pw_passwd);
(void)memset(clear, 0, _PASSWORD_LEN);
if (strcmp(password, pp->pw_passwd) == 0)
break;
warning("single-user login failed");
}
}
(void)endttyent();
endpwent();
#endif /* SECURE */
#ifdef ALTSHELL
(void)fprintf(stderr,
"Enter pathname of shell or RETURN for %s: ", shell);
if (fgets(altshell, sizeof(altshell), stdin) == NULL) {
altshell[0] = '\0';
} else {
/* nuke \n */
char *p;
if ((p = strchr(altshell, '\n')) != NULL)
*p = '\0';
}
if (altshell[0])
shell = altshell;
#endif /* ALTSHELL */
/*
* Unblock signals.
* We catch all the interesting ones,
* and those are reset to SIG_DFL on exec.
*/
(void)sigemptyset(&mask);
(void)sigprocmask(SIG_SETMASK, &mask, NULL);
/*
* Fire off a shell.
* If the default one doesn't work, try the Bourne shell.
*/
argv[0] = "-sh";
argv[1] = 0;
(void)setenv("PATH", INIT_PATH, 1);
#ifdef ALTSHELL
if (altshell[0])
argv[0] = altshell;
(void)execv(shell, __UNCONST(argv));
emergency("can't exec `%s' for single user: %m", shell);
argv[0] = "-sh";
#endif /* ALTSHELL */
(void)execv(INIT_BSHELL, __UNCONST(argv));
emergency("can't exec `%s' for single user: %m", INIT_BSHELL);
(void)sleep(STALL_TIMEOUT);
_exit(3);
}
if (pid == -1) {
/*
* We are seriously hosed. Do our best.
*/
emergency("can't fork single-user shell: %m, trying again");
while (waitpid(-1, NULL, WNOHANG) > 0)
continue;
(void)sigaction(SIGTSTP, &satstp, NULL);
(void)sigaction(SIGHUP, &sahup, NULL);
return (state_func_t)single_user;
}
requested_transition = 0;
do {
if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
collect_child(wpid, status);
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("shell stopped, restarting");
(void)kill(pid, SIGCONT);
wpid = -1;
}
} while (wpid != pid && !requested_transition);
if (requested_transition) {
(void)sigaction(SIGTSTP, &satstp, NULL);
(void)sigaction(SIGHUP, &sahup, NULL);
return (state_func_t)requested_transition;
}
if (WIFSIGNALED(status)) {
if (WTERMSIG(status) == SIGKILL) {
/* executed /sbin/reboot; wait for the end quietly */
sigset_t s;
(void)sigfillset(&s);
for (;;)
(void)sigsuspend(&s);
} else {
warning("single user shell terminated (%x), restarting",
status);
(void)sigaction(SIGTSTP, &satstp, NULL);
(void)sigaction(SIGHUP, &sahup, NULL);
return (state_func_t)single_user;
}
}
runcom_mode = FASTBOOT;
(void)sigaction(SIGTSTP, &satstp, NULL);
(void)sigaction(SIGHUP, &sahup, NULL);
#ifndef LETS_GET_SMALL
return (state_func_t)runcom;
#else /* LETS_GET_SMALL */
return (state_func_t)single_user;
#endif /* LETS_GET_SMALL */
}
#ifndef LETS_GET_SMALL
/* ARGSUSED */
static state_func_t
runetcrc(int trychroot)
{
pid_t pid, wpid;
int status;
const char *argv[4];
struct sigaction sa;
switch ((pid = fork())) {
case 0:
(void)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;
(void)sigprocmask(SIG_SETMASK, &sa.sa_mask, NULL);
#ifdef CHROOT
if (trychroot)
if (chroot(rootdir) != 0) {
warning("failed to chroot to `%s': %m",
rootdir);
_exit(4); /* force single user mode */
}
#endif /* CHROOT */
(void)execv(INIT_BSHELL, __UNCONST(argv));
stall("can't exec `%s' for `%s': %m", INIT_BSHELL, _PATH_RUNCOM);
_exit(5); /* force single user mode */
/*NOTREACHED*/
case -1:
emergency("can't fork for `%s' on `%s': %m", INIT_BSHELL,
_PATH_RUNCOM);
while (waitpid(-1, NULL, WNOHANG) > 0)
continue;
(void)sleep(STALL_TIMEOUT);
return (state_func_t)single_user;
default:
break;
}
/*
* Copied from single_user(). This is a bit paranoid.
*/
do {
if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
collect_child(wpid, status);
if (wpid == -1) {
if (errno == EINTR)
continue;
warning("wait for `%s' on `%s' failed: %m; going to "
"single user mode", INIT_BSHELL, _PATH_RUNCOM);
return (state_func_t)single_user;
}
if (wpid == pid && WIFSTOPPED(status)) {
warning("`%s' on `%s' stopped, restarting",
INIT_BSHELL, _PATH_RUNCOM);
(void)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;
(void)sigfillset(&s);
for (;;)
(void)sigsuspend(&s);
}
if (!WIFEXITED(status)) {
warning("`%s' on `%s' terminated abnormally, going to "
"single user mode", INIT_BSHELL, _PATH_RUNCOM);
return (state_func_t)single_user;
}
if (WEXITSTATUS(status))
return (state_func_t)single_user;
return (state_func_t)read_ttys;
}
/*
* Run the system startup script.
*/
static state_func_t
runcom(void)
{
state_func_t next_step;
/* Run /etc/rc and choose next state depending on the result. */
next_step = runetcrc(0);
if (next_step != (state_func_t)read_ttys)
return (state_func_t)next_step;
#ifdef CHROOT
/*
* If init.root sysctl does not point to "/", we'll chroot and run
* The Real(tm) /etc/rc now. Global variable rootdir will tell us
* where to go.
*/
if (shouldchroot()) {
next_step = runetcrc(1);
if (next_step != (state_func_t)read_ttys)
return (state_func_t)next_step;
did_multiuser_chroot = 1;
} else {
did_multiuser_chroot = 0;
}
#endif /* CHROOT */
/*
* Regardless of whether in chroot or not, we booted successfully.
* It's time to spawn gettys (ie. next_step's value at this point).
*/
runcom_mode = AUTOBOOT; /* the default */
/* NB: should send a message to the session logger to avoid blocking. */
#ifdef SUPPORT_UTMPX
logwtmpx("~", "reboot", "", 0, INIT_PROCESS);
#endif
#ifdef SUPPORT_UTMP
logwtmp("~", "reboot", "");
#endif
return (state_func_t)read_ttys;
}
/*
* 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: %m");
if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == 0) {
emergency("session database open: %m");
return 1;
}
return 0;
}
/*
* Add a new login session.
*/
static void
add_session(session_t *sp)
{
DBT key;
DBT data;
if (session_db == NULL)
return;
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: %m", sp->se_process);
#ifdef SUPPORT_UTMPX
session_utmpx(sp, 1);
#endif
}
/*
* 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: %m", sp->se_process);
#ifdef SUPPORT_UTMPX
session_utmpx(sp, 0);
#endif
}
/*
* Look up a login session by pid.
*/
static session_t *
find_session(pid_t pid)
{
DBT key;
DBT data;
session_t *ret;
if (session_db == NULL)
return NULL;
key.data = &pid;
key.size = sizeof pid;
if ((*session_db->get)(session_db, &key, &data, 0) != 0)
return 0;
(void)memmove(&ret, data.data, sizeof(ret));
return ret;
}
/*
* Construct an argument vector from a command line.
*/
static char **
construct_argv(char *command)
{
int argc = 0;
char **argv = malloc(((strlen(command) + 1) / 2 + 1) * sizeof (char *));
static const char separators[] = " \t";
if (argv == NULL)
return NULL;
if ((argv[argc++] = strtok(command, separators)) == 0) {
free(argv);
return NULL;
}
while ((argv[argc++] = strtok(NULL, separators)) != 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);
}
if (sp->se_window) {
free(sp->se_window);
free(sp->se_window_argv);
}
free(sp);
}
/*
* Allocate a new session descriptor.
*/
static 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 == NULL ||
typ->ty_getty == NULL)
return NULL;
sp = malloc(sizeof (session_t));
if (sp == NULL)
return NULL;
(void)memset(sp, 0, sizeof *sp);
sp->se_flags = SE_PRESENT;
sp->se_index = session_index;
(void)asprintf(&sp->se_device, "%s%s", _PATH_DEV, typ->ty_name);
if (!sp->se_device) {
free(sp);
return NULL;
}
if (setupargv(sp, typ) == 0) {
free_session(sp);
return NULL;
}
sp->se_next = NULL;
if (sprev == NULL) {
sessions = sp;
sp->se_prev = NULL;
} 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);
}
(void)asprintf(&sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name);
if (!sp->se_getty)
return 0;
sp->se_getty_argv = construct_argv(sp->se_getty);
if (sp->se_getty_argv == NULL) {
warning("can't parse getty for port `%s'", sp->se_device);
free(sp->se_getty);
sp->se_getty = NULL;
return 0;
}
if (typ->ty_window) {
if (sp->se_window)
free(sp->se_window);
sp->se_window = strdup(typ->ty_window);
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.
*/
static state_func_t
read_ttys(void)
{
int session_index = 0;
session_t *sp, *snext;
struct ttyent *typ;
#ifdef SUPPORT_UTMPX
if (sessions == NULL) {
struct stat st;
make_utmpx("", BOOT_MSG, BOOT_TIME, 0, &boot_time, 0);
/*
* If wtmpx is not empty, pick the down time from there
*/
if (stat(_PATH_WTMPX, &st) != -1 && st.st_size != 0) {
struct timeval down_time;
TIMESPEC_TO_TIMEVAL(&down_time,
st.st_atime > st.st_mtime ?
&st.st_atimespec : &st.st_mtimespec);
make_utmpx("", DOWN_MSG, DOWN_TIME, 0, &down_time, 0);
}
}
#endif
/*
* Destroy any previous session state.
* There shouldn't be any, but just in case...
*/
for (sp = sessions; sp; sp = snext) {
#ifndef LETS_GET_SMALL
if (sp->se_process)
clear_session_logs(sp, 0);
#endif
snext = sp->se_next;
free_session(sp);
}
sessions = NULL;
if (start_session_db()) {
warning("start_session_db failed, death");
#ifdef CHROOT
/* If /etc/rc ran in chroot, we want to kill any survivors. */
if (did_multiuser_chroot)
return (state_func_t)death;
else
#endif /* CHROOT */
return (state_func_t)single_user;
}
(void)do_setttyent();
/*
* 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;
(void)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;
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;
(void)sigemptyset(&mask);
(void)sigprocmask(SIG_SETMASK, &mask, NULL);
if (setsid() < 0)
emergency("setsid failed (window): %m");
(void)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(6);
}
/*
* Start a login session running.
*/
static pid_t
start_getty(session_t *sp)
{
pid_t pid;
sigset_t mask;
time_t current_time = time(NULL);
bool do_sleep = false;
if (current_time >= sp->se_started.tv_sec &&
current_time - sp->se_started.tv_sec < GETTY_SPACING) {
if (++sp->se_nspace > GETTY_NSPACE) {
sp->se_nspace = 0;
do_sleep = true;
}
} 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;
#ifdef CHROOT
/* If /etc/rc did proceed inside chroot, we have to try as well. */
if (did_multiuser_chroot)
if (chroot(rootdir) != 0) {
stall("can't chroot getty `%s' inside `%s': %m",
sp->se_getty_argv[0], rootdir);
_exit(7);
}
#endif /* CHROOT */
if (do_sleep) {
warning("getty repeating too quickly on port `%s', sleeping",
sp->se_device);
(void)sleep(GETTY_SLEEP);
}
if (sp->se_window) {
start_window_system(sp);
(void)sleep(WINDOW_WAIT);
}
(void)sigemptyset(&mask);
(void)sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
(void)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(8);
/*NOTREACHED*/
}
#ifdef SUPPORT_UTMPX
static void
session_utmpx(const session_t *sp, int add)
{
const char *name = sp->se_getty ? sp->se_getty :
(sp->se_window ? sp->se_window : "");
const char *line = sp->se_device + sizeof(_PATH_DEV) - 1;
make_utmpx(name, line, add ? LOGIN_PROCESS : DEAD_PROCESS,
sp->se_process, &sp->se_started, sp->se_index);
}
static void
make_utmpx(const char *name, const char *line, int type, pid_t pid,
const struct timeval *tv, int session)
{
struct utmpx ut;
const char *eline;
(void)memset(&ut, 0, sizeof(ut));
(void)strlcpy(ut.ut_name, name, sizeof(ut.ut_name));
ut.ut_type = type;
(void)strlcpy(ut.ut_line, line, sizeof(ut.ut_line));
ut.ut_pid = pid;
if (tv)
ut.ut_tv = *tv;
else
(void)gettimeofday(&ut.ut_tv, NULL);
ut.ut_session = session;
eline = line + strlen(line);
if ((size_t)(eline - line) >= sizeof(ut.ut_id))
line = eline - sizeof(ut.ut_id);
(void)strncpy(ut.ut_id, line, sizeof(ut.ut_id));
if (pututxline(&ut) == NULL)
warning("can't add utmpx record for `%s': %m", ut.ut_line);
endutxent();
}
static char
get_runlevel(const state_t s)
{
if (s == (state_t)single_user)
return SINGLE_USER;
if (s == (state_t)runcom)
return RUNCOM;
if (s == (state_t)read_ttys)
return READ_TTYS;
if (s == (state_t)multi_user)
return MULTI_USER;
if (s == (state_t)clean_ttys)
return CLEAN_TTYS;
if (s == (state_t)catatonia)
return CATATONIA;
return DEATH;
}
static void
utmpx_set_runlevel(char old, char new)
{
struct utmpx ut;
/*
* Don't record any transitions until we did the first transition
* to read ttys, which is when we are guaranteed to have a read-write
* /var. Perhaps use a different variable for this?
*/
if (sessions == NULL)
return;
(void)memset(&ut, 0, sizeof(ut));
(void)snprintf(ut.ut_line, sizeof(ut.ut_line), RUNLVL_MSG, new);
ut.ut_type = RUN_LVL;
(void)gettimeofday(&ut.ut_tv, NULL);
ut.ut_exit.e_exit = old;
ut.ut_exit.e_termination = new;
if (pututxline(&ut) == NULL)
warning("can't add utmpx record for `runlevel': %m");
endutxent();
}
#endif /* SUPPORT_UTMPX */
#endif /* LETS_GET_SMALL */
/*
* Collect exit status for a child.
* If an exiting login, start a new login running.
*/
static void
collect_child(pid_t pid, int status)
{
#ifndef LETS_GET_SMALL
session_t *sp, *sprev, *snext;
if (! sessions)
return;
if ((sp = find_session(pid)) == NULL)
return;
clear_session_logs(sp, status);
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;
(void)gettimeofday(&sp->se_started, NULL);
add_session(sp);
#endif /* LETS_GET_SMALL */
}
/*
* Catch a signal and request a state transition.
*/
static void
transition_handler(int sig)
{
switch (sig) {
#ifndef LETS_GET_SMALL
case SIGHUP:
requested_transition = clean_ttys;
break;
case SIGTERM:
requested_transition = death;
break;
case SIGTSTP:
requested_transition = catatonia;
break;
#endif /* LETS_GET_SMALL */
default:
requested_transition = 0;
break;
}
}
#ifndef LETS_GET_SMALL
/*
* Take the system multiuser.
*/
static state_func_t
multi_user(void)
{
pid_t pid;
int status;
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;
(void)gettimeofday(&sp->se_started, NULL);
add_session(sp);
}
while (!requested_transition)
if ((pid = waitpid(-1, &status, 0)) != -1)
collect_child(pid, status);
return (state_func_t)requested_transition;
}
/*
* This is an n-squared 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;
for (sp = sessions; sp; sp = sp->se_next)
sp->se_flags &= ~SE_PRESENT;
(void)do_setttyent();
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) {
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;
if (sp->se_process != 0)
(void)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;
if (sp->se_process != 0)
(void)kill(sp->se_process, SIGHUP);
} else {
sp->se_nspace = 0;
}
continue;
}
(void)new_session(sprev, session_index, typ);
}
(void)endttyent();
for (sp = sessions; sp; sp = sp->se_next)
if ((sp->se_flags & SE_PRESENT) == 0) {
sp->se_flags |= SE_SHUTDOWN;
if (sp->se_process != 0)
(void)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;
}
#endif /* LETS_GET_SMALL */
/*
* Note SIGALRM.
*/
static void
/*ARGSUSED*/
alrm_handler(int sig)
{
clang = 1;
}
#ifndef LETS_GET_SMALL
/*
* Bring the system down to single user.
*/
static state_func_t
death(void)
{
session_t *sp;
int i, status;
pid_t pid;
static const int death_sigs[3] = { SIGHUP, SIGTERM, SIGKILL };
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. */
#ifdef SUPPORT_UTMPX
logwtmpx("~", "shutdown", "", 0, INIT_PROCESS);
#endif
#ifdef SUPPORT_UTMP
logwtmp("~", "shutdown", "");
#endif
for (i = 0; i < 3; ++i) {
if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH)
return (state_func_t)single_user;
clang = 0;
(void)alarm(DEATH_WATCH);
do
if ((pid = waitpid(-1, &status, 0)) != -1)
collect_child(pid, status);
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;
}
#endif /* LETS_GET_SMALL */
#ifdef MFS_DEV_IF_NO_CONSOLE
static int
mfs_dev(void)
{
/*
* We cannot print errors so we bail out silently...
*/
pid_t pid;
int status;
/* If we have /dev/console, assume all is OK */
if (access(_PATH_CONSOLE, F_OK) == 0)
return 0;
#if 0 /* Useful for testing MAKEDEV */
/* Mount an mfs over /mnt so we can create a console entry */
switch ((pid = fork())) {
case 0:
(void)execl(INIT_MOUNT_MFS, "mount_mfs",
"-b", "4096", "-f", "512",
"-s", 64, "-n", 10,
"-p", "0755",
"swap", "/mnt", NULL);
_exit(9);
/*NOTREACHED*/
case -1:
return(-1);
default:
if (waitpid(pid, &status, 0) == -1)
return(-1);
if (status != 0)
return(-1);
break;
}
{
dev_t dev;
#ifdef CPU_CONSDEV
static int name[2] = { CTL_MACHDEP, CPU_CONSDEV };
size_t olen;
olen = sizeof(dev);
if (sysctl(name, sizeof(name) / sizeof(name[0]), &dev, &olen,
NULL, 0) == -1)
#endif
dev = makedev(0, 0);
/* Make a console for us, so we can see things happening */
if (mknod("/mnt/console", 0666 | S_IFCHR, dev) == -1)
return(-1);
(void)freopen("/mnt/console", "a", stderr);
}
#endif
/* Run the makedev script to create devices */
switch ((pid = fork())) {
case 0:
(void)dup2(2, 1); /* Give the script stdout */
if (chdir("/dev") == 0)
(void)execl(INIT_BSHELL, "sh",
access("./MAKEDEV", X_OK) == 0
? "./MAKEDEV" : "/etc/MAKEDEV",
"-MM", "init", NULL);
_exit(10);
/* NOTREACHED */
case -1:
break;
default:
if (waitpid(pid, &status, 0) == -1)
break;
if (status != 0)
warn("MAKEDEV exit status %d", status);
/*
* If /dev/console got created, then return 0
* regardless of MAKEDEV exit status.
*/
if (access(_PATH_CONSOLE, F_OK) == 0)
return 0;
_exit(11);
}
warn("Unable to run MAKEDEV");
_exit(12);
}
#endif
#ifndef LETS_GET_SMALL
static int
do_setttyent(void)
{
(void)endttyent();
#ifdef CHROOT
if (did_multiuser_chroot) {
char path[PATH_MAX];
(void)snprintf(path, sizeof(path), "%s/%s", rootdir, _PATH_TTYS);
return setttyentpath(path);
} else
#endif /* CHROOT */
return setttyent();
}
#endif
#if !defined(LETS_GET_SMALL) && defined(CHROOT)
static int
createsysctlnode(void)
{
struct sysctlnode node;
int mib[2];
size_t len;
/*
* Create top-level dynamic sysctl node. Its child nodes will only
* be readable by the superuser, since regular mortals should not
* care ("Sssh, it's a secret!").
*/
len = sizeof(struct sysctlnode);
mib[0] = CTL_CREATE;
(void)memset(&node, 0, len);
node.sysctl_flags = SYSCTL_VERSION | CTLFLAG_READWRITE |
CTLFLAG_PRIVATE | CTLTYPE_NODE;
node.sysctl_num = CTL_CREATE;
(void)snprintf(node.sysctl_name, SYSCTL_NAMELEN, "init");
if (sysctl(&mib[0], 1, &node, &len, &node, len) == -1) {
warning("could not create init node: %m");
return -1;
}
/*
* Create second level dynamic node capable of holding pathname.
* Provide "/" as the default value.
*/
len = sizeof(struct sysctlnode);
mib[0] = node.sysctl_num;
mib[1] = CTL_CREATE;
(void)memset(&node, 0, len);
node.sysctl_flags = SYSCTL_VERSION | CTLFLAG_READWRITE |
CTLTYPE_STRING | CTLFLAG_OWNDATA;
node.sysctl_size = _POSIX_PATH_MAX;
node.sysctl_data = __UNCONST("/");
node.sysctl_num = CTL_CREATE;
(void)snprintf(node.sysctl_name, SYSCTL_NAMELEN, "root");
if (sysctl(&mib[0], 2, NULL, NULL, &node, len) == -1) {
warning("could not create init.root node: %m");
return -1;
}
return 0;
}
static int
shouldchroot(void)
{
struct sysctlnode node;
size_t len, cnt;
int mib;
len = sizeof(struct sysctlnode);
if (sysctlbyname("init.root", rootdir, &len, NULL, 0) == -1) {
warning("could not read init.root: %m");
/* Child killed our node. Recreate it. */
if (errno == ENOENT) {
/* Destroy whatever is left, recreate from scratch. */
if (sysctlnametomib("init", &mib, &cnt) != -1) {
(void)memset(&node, 0, sizeof(node));
node.sysctl_flags = SYSCTL_VERSION;
node.sysctl_num = mib;
mib = CTL_DESTROY;
(void)sysctl(&mib, 1, NULL, NULL, &node,
sizeof(node));
}
(void)createsysctlnode();
}
/* We certainly won't chroot. */
return 0;
}
if (rootdir[len] != '\0' || strlen(rootdir) != len - 1) {
warning("init.root is not a string");
return 0;
}
if (strcmp(rootdir, "/") == 0)
return 0;
return 1;
}
#endif /* !LETS_GET_SMALL && CHROOT */
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