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NetBSD/sbin/init/init.c

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/* $NetBSD: init.c,v 1.69 2005/03/15 23:43:50 xtraeme 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\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
__RCSID("$NetBSD: init.c,v 1.69 2005/03/15 23:43:50 xtraeme 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 <sys/sysctl.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>
#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 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 */
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
int main(int, char *[]);
void handle(sig_t, ...);
void delset(sigset_t *, ...);
void stall(const char *, ...)
__attribute__((__format__(__printf__,1,2)));
void warning(const char *, ...)
__attribute__((__format__(__printf__,1,2)));
void emergency(const char *, ...)
__attribute__((__format__(__printf__,1,2)));
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);
enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT;
void transition(state_t);
#ifndef LETS_GET_SMALL
state_t requested_transition = runcom;
#else /* LETS_GET_SMALL */
state_t requested_transition = single_user;
#endif /* LETS_GET_SMALL */
void setctty(const 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 */
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, int);
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;
#ifndef LETS_GET_SMALL
void clear_session_logs(session_t *, int);
#endif
int start_session_db(void);
void add_session(session_t *);
void del_session(session_t *);
session_t *find_session(pid_t);
DB *session_db;
#ifdef MFS_DEV_IF_NO_CONSOLE
#define NINODE 1024
#define FSSIZE ((8192 /* boot area */ \
+ 2 * 8192 /* two copies of superblock */ \
+ 4096 /* cylinder group info */ \
+ NINODE * (128 + 18) /* inode and directory entry */ \
+ mfile[0].len /* size of MAKEDEV file */ \
+ 2 * 4096) / 512) /* some slack */
struct mappedfile {
const char *path;
char *buf;
int len;
} mfile[] = {
{ "/dev/MAKEDEV", NULL, 0 },
{ "/dev/MAKEDEV.local", NULL, 0 }
};
static int mfs_dev(void);
static void mapfile(struct mappedfile *);
static void writefile(struct mappedfile *);
#endif
/*
* The mother of all processes.
*/
int
main(int argc, char **argv)
{
struct sigaction sa;
sigset_t mask;
#ifndef LETS_GET_SMALL
int c;
/* 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);
/*
* Start the state machine.
*/
transition(requested_transition);
/*
* Should never reach here.
*/
return 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);
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.
*/
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);
}
/*
* 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(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.
*/
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.
*/
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.
*/
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));
(void)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: %m");
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: %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.
*/
void
transition(state_t s)
{
if (s == NULL)
return;
for (;;)
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.
*/
void
clear_session_logs(session_t *sp, int status)
{
char *line = sp->se_device + sizeof(_PATH_DEV) - 1;
#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.
*/
void
setctty(const char *name)
{
int fd;
(void) revoke(name);
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(1);
}
}
/*
* Bring the system up single user.
*/
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
char *argv[2];
#ifdef SECURE
struct ttyent *typ;
struct passwd *pp;
char *clear, *password;
#endif
#ifdef ALTSHELL
char altshell[128];
#endif /* ALTSHELL */
/*
* 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\n");
}
}
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;
setenv("PATH", INIT_PATH, 1);
#ifdef ALTSHELL
if (altshell[0])
argv[0] = altshell;
(void)execv(shell, argv);
emergency("can't exec %s for single user: %m", shell);
argv[0] = "-sh";
#endif /* ALTSHELL */
(void)execv(INIT_BSHELL, argv);
emergency("can't exec %s for single user: %m", INIT_BSHELL);
(void)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;
(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("init: shell stopped, restarting\n");
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, restarting");
(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
/*
* Run the system startup script.
*/
state_func_t
runcom(void)
{
pid_t pid, wpid;
int status;
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);
(void)execv(INIT_BSHELL, argv);
stall("can't exec %s for %s: %m", INIT_BSHELL, _PATH_RUNCOM);
_exit(1); /* 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("init: %s on %s stopped, restarting\n",
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;
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?
*/
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.
*/
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);
}
/*
* 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: %m", sp->se_process);
}
/*
* Look up a login session by pid.
*/
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.
*/
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[argc++] = strtok(command, separators)) == 0)
return (NULL);
while ((argv[argc++] = strtok(NULL, separators)) != NULL)
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 == NULL ||
typ->ty_getty == NULL)
return (NULL);
sp = malloc(sizeof (session_t));
if (sp == NULL)
return NULL;
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)
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.
*/
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.
*/
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) {
#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())
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.
*/
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");
(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(1);
}
/*
* Start a login session running.
*/
pid_t
start_getty(session_t *sp)
{
pid_t pid;
sigset_t mask;
time_t current_time = time(NULL);
/*
* 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 (current_time > sp->se_started &&
current_time - sp->se_started < GETTY_SPACING) {
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(1);
/*NOTREACHED*/
}
#endif /* LETS_GET_SMALL */
/*
* Collect exit status for a child.
* If an exiting login, start a new login running.
*/
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;
sp->se_started = time(NULL);
add_session(sp);
#endif /* LETS_GET_SMALL */
}
/*
* Catch a signal and request a state transition.
*/
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.
*/
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;
sp->se_started = time(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...
*/
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()) != 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);
}
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;
if (sp->se_process != 0)
(void)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;
}
#endif /* LETS_GET_SMALL */
/*
* Note SIGALRM.
*/
void
/*ARGSUSED*/
alrm_handler(int sig)
{
clang = 1;
}
#ifndef LETS_GET_SMALL
/*
* Bring the system down to single user.
*/
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;
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 void
mapfile(struct mappedfile *mf)
{
int fd;
struct stat st;
if (lstat(mf->path, &st) == -1)
return;
if ((st.st_mode & S_IFMT) == S_IFLNK) {
mf->buf = malloc(st.st_size + 1);
mf->buf[st.st_size] = 0;
if (readlink(mf->path, mf->buf, st.st_size) != st.st_size)
return;
mf->len = -1;
return;
}
if ((fd = open(mf->path, O_RDONLY)) == -1)
return;
mf->buf = mmap(0, (size_t)st.st_size, PROT_READ,
MAP_FILE|MAP_SHARED, fd, (off_t)0);
(void)close(fd);
if (mf->buf == MAP_FAILED)
return;
mf->len = st.st_size;
}
static void
writefile(struct mappedfile *mf)
{
int fd;
if (mf->len == -1) {
symlink(mf->buf, mf->path);
free(mf->buf);
return;
}
if (mf->len == 0)
return;
fd = open(mf->path, O_WRONLY | O_CREAT | O_TRUNC, 0755);
if (fd == -1)
return;
(void)write(fd, mf->buf, mf->len);
(void)munmap(mf->buf, mf->len);
(void)close(fd);
}
static int
mfs_dev(void)
{
/*
* We cannot print errors so we bail out silently...
*/
pid_t pid;
int status;
dev_t dev;
char *fs_size;
#ifdef CPU_CONSDEV
static int name[2] = { CTL_MACHDEP, CPU_CONSDEV };
size_t olen;
#endif
/* If we have /dev/console, assume all is OK */
if (access(_PATH_CONSOLE, F_OK) != -1)
return(0);
/* Grab the contents of MAKEDEV */
mapfile(&mfile[0]);
/* Grab the contents of MAKEDEV.local */
mapfile(&mfile[1]);
/* Mount an mfs over /dev so we can create devices */
switch ((pid = fork())) {
case 0:
asprintf(&fs_size, "%d", FSSIZE);
(void)execl(INIT_MOUNT_MFS, "mount_mfs",
"-b", "4096", "-f", "512",
"-s", fs_size, "-n", STR(NINODE),
"-p", "0755",
"swap", "/dev", NULL);
_exit(1);
/*NOTREACHED*/
case -1:
return(-1);
default:
if (waitpid(pid, &status, 0) == -1)
return(-1);
if (status != 0)
return(-1);
break;
}
#ifdef CPU_CONSDEV
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(_PATH_CONSOLE, 0666 | S_IFCHR, dev) == -1)
return(-1);
(void)freopen(_PATH_CONSOLE, "a", stderr);
warnx("Creating mfs /dev (%d blocks, %d inodes)", FSSIZE, NINODE);
/* Create a MAKEDEV script in the mfs /dev */
writefile(&mfile[0]);
/* Create a MAKEDEV.local script in the mfs /dev */
writefile(&mfile[1]);
/* Run the makedev script to create devices */
switch ((pid = fork())) {
case 0:
dup2(2, 1); /* Give the script stdout */
if (chdir("/dev") == 0)
(void)execl(INIT_BSHELL, "sh",
mfile[0].len ? "./MAKEDEV" : "/etc/MAKEDEV",
"init", NULL);
_exit(1);
case -1:
break;
default:
if (waitpid(pid, &status, 0) == -1)
break;
if (status != 0) {
errno = EINVAL;
break;
}
return 0;
}
warn("Unable to run MAKEDEV");
return (-1);
}
#endif
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