003 File Manager
Current Path:
/usr/src/sbin/init
usr
/
src
/
sbin
/
init
/
📁
..
📄
Makefile
(674 B)
📄
Makefile.depend
(304 B)
📄
NOTES
(4.63 KB)
📄
init.8
(11.72 KB)
📄
init.c
(44.34 KB)
📄
pathnames.h
(2.03 KB)
📄
ttys.aarch64
(2.05 KB)
📄
ttys.amd64
(2.04 KB)
📄
ttys.arm
(2.04 KB)
📄
ttys.i386
(2.04 KB)
📄
ttys.mips
(1.47 KB)
📄
ttys.powerpc
(2.04 KB)
📄
ttys.riscv
(2.13 KB)
Editing: init.c
/*- * SPDX-License-Identifier: BSD-3-Clause * * 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 const char copyright[] = "@(#) Copyright (c) 1991, 1993\n\ The Regents of the University of California. All rights reserved.\n"; #endif /* not lint */ #ifndef lint #if 0 static char sccsid[] = "@(#)init.c 8.1 (Berkeley) 7/15/93"; #endif static const char rcsid[] = "$FreeBSD$"; #endif /* not lint */ #include <sys/param.h> #include <sys/ioctl.h> #include <sys/mman.h> #include <sys/mount.h> #include <sys/sysctl.h> #include <sys/wait.h> #include <sys/stat.h> #include <sys/uio.h> #include <db.h> #include <errno.h> #include <fcntl.h> #include <kenv.h> #include <libutil.h> #include <paths.h> #include <signal.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <syslog.h> #include <time.h> #include <ttyent.h> #include <unistd.h> #include <sys/reboot.h> #include <err.h> #include <stdarg.h> #ifdef SECURE #include <pwd.h> #endif #ifdef LOGIN_CAP #include <login_cap.h> #endif #include "mntopts.h" #include "pathnames.h" /* * Sleep times; used to prevent thrashing. */ #define GETTY_SPACING 5 /* N secs minimum getty spacing */ #define GETTY_SLEEP 30 /* sleep N secs after spacing problem */ #define GETTY_NSPACE 3 /* max. spacing count to bring reaction */ #define WINDOW_WAIT 3 /* wait N secs after starting window */ #define STALL_TIMEOUT 30 /* wait N secs after warning */ #define DEATH_WATCH 10 /* wait N secs for procs to die */ #define DEATH_SCRIPT 120 /* wait for 2min for /etc/rc.shutdown */ #define RESOURCE_RC "daemon" #define RESOURCE_WINDOW "default" #define RESOURCE_GETTY "default" static void handle(sig_t, ...); static void delset(sigset_t *, ...); static void stall(const char *, ...) __printflike(1, 2); static void warning(const char *, ...) __printflike(1, 2); static void emergency(const char *, ...) __printflike(1, 2); static void disaster(int); static void revoke_ttys(void); static int runshutdown(void); static char *strk(char *); /* * We really need a recursive typedef... * The following at least guarantees that the return type of (*state_t)() * is sufficiently wide to hold a function pointer. */ typedef long (*state_func_t)(void); typedef state_func_t (*state_t)(void); static state_func_t single_user(void); static state_func_t runcom(void); static state_func_t read_ttys(void); static state_func_t multi_user(void); static state_func_t clean_ttys(void); static state_func_t catatonia(void); static state_func_t death(void); static state_func_t death_single(void); static state_func_t reroot(void); static state_func_t reroot_phase_two(void); static state_func_t run_script(const char *); static enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT; #define FALSE 0 #define TRUE 1 static int Reboot = FALSE; static int howto = RB_AUTOBOOT; static int devfs; static char *init_path_argv0; static void transition(state_t); static state_t requested_transition; static state_t current_state = death_single; static void execute_script(char *argv[]); static void open_console(void); static const char *get_shell(void); static void replace_init(char *path); static void write_stderr(const char *message); typedef struct init_session { 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_IFEXISTS 0x4 /* session defined as "onifexists" */ #define SE_IFCONSOLE 0x8 /* session defined as "onifconsole" */ int se_nspace; /* spacing count */ char *se_device; /* filename of port */ char *se_getty; /* what to run on that port */ char *se_getty_argv_space; /* pre-parsed argument array space */ char **se_getty_argv; /* pre-parsed argument array */ char *se_window; /* window system (started only once) */ char *se_window_argv_space; /* pre-parsed argument array space */ char **se_window_argv; /* pre-parsed argument array */ char *se_type; /* default terminal type */ struct init_session *se_prev; struct init_session *se_next; } session_t; static void free_session(session_t *); static session_t *new_session(session_t *, struct ttyent *); static session_t *sessions; static char **construct_argv(char *); static void start_window_system(session_t *); static void collect_child(pid_t); static pid_t start_getty(session_t *); static void transition_handler(int); static void alrm_handler(int); static void setsecuritylevel(int); static int getsecuritylevel(void); static int setupargv(session_t *, struct ttyent *); #ifdef LOGIN_CAP static void setprocresources(const char *); #endif static int clang; static int start_session_db(void); static void add_session(session_t *); static void del_session(session_t *); static session_t *find_session(pid_t); static DB *session_db; /* * The mother of all processes. */ int main(int argc, char *argv[]) { state_t initial_transition = runcom; char kenv_value[PATH_MAX]; int c, error; struct sigaction sa; sigset_t mask; /* Dispose of random users. */ if (getuid() != 0) errx(1, "%s", strerror(EPERM)); /* System V users like to reexec init. */ if (getpid() != 1) { #ifdef COMPAT_SYSV_INIT /* So give them what they want */ if (argc > 1) { if (strlen(argv[1]) == 1) { char runlevel = *argv[1]; int sig; switch (runlevel) { case '0': /* halt + poweroff */ sig = SIGUSR2; break; case '1': /* single-user */ sig = SIGTERM; break; case '6': /* reboot */ sig = SIGINT; break; case 'c': /* block further logins */ sig = SIGTSTP; break; case 'q': /* rescan /etc/ttys */ sig = SIGHUP; break; case 'r': /* remount root */ sig = SIGEMT; break; default: goto invalid; } kill(1, sig); _exit(0); } else invalid: errx(1, "invalid run-level ``%s''", argv[1]); } else #endif errx(1, "already running"); } init_path_argv0 = strdup(argv[0]); if (init_path_argv0 == NULL) err(1, "strdup"); /* * Note that this does NOT open a file... * Does 'init' deserve its own facility number? */ openlog("init", LOG_CONS, LOG_AUTH); /* * Create an initial session. */ if (setsid() < 0 && (errno != EPERM || getsid(0) != 1)) 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, "dsfr")) != -1) switch (c) { case 'd': devfs = 1; break; case 's': initial_transition = single_user; break; case 'f': runcom_mode = FASTBOOT; break; case 'r': initial_transition = reroot_phase_two; 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(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS, SIGXCPU, SIGXFSZ, 0); handle(transition_handler, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP, SIGUSR1, SIGUSR2, SIGWINCH, 0); handle(alrm_handler, SIGALRM, 0); sigfillset(&mask); delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS, SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP, SIGALRM, SIGUSR1, SIGUSR2, SIGWINCH, 0); sigprocmask(SIG_SETMASK, &mask, NULL); sigemptyset(&sa.sa_mask); sa.sa_flags = 0; sa.sa_handler = SIG_IGN; sigaction(SIGTTIN, &sa, NULL); sigaction(SIGTTOU, &sa, NULL); /* * Paranoia. */ close(0); close(1); close(2); if (kenv(KENV_GET, "init_exec", kenv_value, sizeof(kenv_value)) > 0) { replace_init(kenv_value); _exit(0); /* reboot */ } if (kenv(KENV_GET, "init_script", kenv_value, sizeof(kenv_value)) > 0) { state_func_t next_transition; if ((next_transition = run_script(kenv_value)) != NULL) initial_transition = (state_t) next_transition; } if (kenv(KENV_GET, "init_chroot", kenv_value, sizeof(kenv_value)) > 0) { if (chdir(kenv_value) != 0 || chroot(".") != 0) warning("Can't chroot to %s: %m", kenv_value); } /* * Additional check if devfs needs to be mounted: * If "/" and "/dev" have the same device number, * then it hasn't been mounted yet. */ if (!devfs) { struct stat stst; dev_t root_devno; stat("/", &stst); root_devno = stst.st_dev; if (stat("/dev", &stst) != 0) warning("Can't stat /dev: %m"); else if (stst.st_dev == root_devno) devfs++; } if (devfs) { struct iovec iov[4]; char *s; int i; char _fstype[] = "fstype"; char _devfs[] = "devfs"; char _fspath[] = "fspath"; char _path_dev[]= _PATH_DEV; iov[0].iov_base = _fstype; iov[0].iov_len = sizeof(_fstype); iov[1].iov_base = _devfs; iov[1].iov_len = sizeof(_devfs); iov[2].iov_base = _fspath; iov[2].iov_len = sizeof(_fspath); /* * Try to avoid the trailing slash in _PATH_DEV. * Be *very* defensive. */ s = strdup(_PATH_DEV); if (s != NULL) { i = strlen(s); if (i > 0 && s[i - 1] == '/') s[i - 1] = '\0'; iov[3].iov_base = s; iov[3].iov_len = strlen(s) + 1; } else { iov[3].iov_base = _path_dev; iov[3].iov_len = sizeof(_path_dev); } nmount(iov, 4, 0); if (s != NULL) free(s); } if (initial_transition != reroot_phase_two) { /* * Unmount reroot leftovers. This runs after init(8) * gets reexecuted after reroot_phase_two() is done. */ error = unmount(_PATH_REROOT, MNT_FORCE); if (error != 0 && errno != EINVAL) warning("Cannot unmount %s: %m", _PATH_REROOT); } /* * Start the state machine. */ transition(initial_transition); /* * Should never reach here. */ return 1; } /* * Associate a function with a signal handler. */ static void handle(sig_t handler, ...) { int sig; struct sigaction sa; sigset_t mask_everything; va_list ap; va_start(ap, handler); sa.sa_handler = handler; sigfillset(&mask_everything); while ((sig = va_arg(ap, int)) != 0) { sa.sa_mask = mask_everything; /* XXX SA_RESTART? */ sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0; sigaction(sig, &sa, 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) sigdelset(maskp, sig); va_end(ap); } /* * Log a message and sleep for a while (to give someone an opportunity * to read it and to save log or hardcopy output if the problem is chronic). * NB: should send a message to the session logger to avoid blocking. */ static void stall(const char *message, ...) { va_list ap; va_start(ap, message); vsyslog(LOG_ALERT, message, ap); va_end(ap); sleep(STALL_TIMEOUT); } /* * Like stall(), but doesn't sleep. * If cpp had variadic macros, the two functions could be #defines for another. * NB: should send a message to the session logger to avoid blocking. */ static void warning(const char *message, ...) { va_list ap; va_start(ap, message); vsyslog(LOG_ALERT, message, ap); va_end(ap); } /* * Log an emergency message. * NB: should send a message to the session logger to avoid blocking. */ static void emergency(const char *message, ...) { va_list ap; va_start(ap, message); vsyslog(LOG_EMERG, message, ap); va_end(ap); } /* * Catch an unexpected signal. */ static void disaster(int sig) { emergency("fatal signal: %s", (unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal"); sleep(STALL_TIMEOUT); _exit(sig); /* reboot */ } /* * Get the security level of the kernel. */ static int getsecuritylevel(void) { #ifdef KERN_SECURELVL int name[2], curlevel; size_t len; name[0] = CTL_KERN; name[1] = KERN_SECURELVL; len = sizeof curlevel; if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) { emergency("cannot get kernel security level: %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; 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) { current_state = s; for (;;) current_state = (state_t) (*current_state)(); } /* * Start a session and allocate a controlling terminal. * Only called by children of init after forking. */ static void open_console(void) { int fd; /* * Try to open /dev/console. Open the device with O_NONBLOCK to * prevent potential blocking on a carrier. */ revoke(_PATH_CONSOLE); if ((fd = open(_PATH_CONSOLE, O_RDWR | O_NONBLOCK)) != -1) { (void)fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK); if (login_tty(fd) == 0) return; close(fd); } /* No luck. Log output to file if possible. */ if ((fd = open(_PATH_DEVNULL, O_RDWR)) == -1) { stall("cannot open null device."); _exit(1); } if (fd != STDIN_FILENO) { dup2(fd, STDIN_FILENO); close(fd); } fd = open(_PATH_INITLOG, O_WRONLY | O_APPEND | O_CREAT, 0644); if (fd == -1) dup2(STDIN_FILENO, STDOUT_FILENO); else if (fd != STDOUT_FILENO) { dup2(fd, STDOUT_FILENO); close(fd); } dup2(STDOUT_FILENO, STDERR_FILENO); } static const char * get_shell(void) { static char kenv_value[PATH_MAX]; if (kenv(KENV_GET, "init_shell", kenv_value, sizeof(kenv_value)) > 0) return kenv_value; else return _PATH_BSHELL; } static void write_stderr(const char *message) { write(STDERR_FILENO, message, strlen(message)); } static int read_file(const char *path, void **bufp, size_t *bufsizep) { struct stat sb; size_t bufsize; void *buf; ssize_t nbytes; int error, fd; fd = open(path, O_RDONLY); if (fd < 0) { emergency("%s: %m", path); return (-1); } error = fstat(fd, &sb); if (error != 0) { emergency("fstat: %m"); close(fd); return (error); } bufsize = sb.st_size; buf = malloc(bufsize); if (buf == NULL) { emergency("malloc: %m"); close(fd); return (error); } nbytes = read(fd, buf, bufsize); if (nbytes != (ssize_t)bufsize) { emergency("read: %m"); close(fd); free(buf); return (error); } error = close(fd); if (error != 0) { emergency("close: %m"); free(buf); return (error); } *bufp = buf; *bufsizep = bufsize; return (0); } static int create_file(const char *path, const void *buf, size_t bufsize) { ssize_t nbytes; int error, fd; fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0700); if (fd < 0) { emergency("%s: %m", path); return (-1); } nbytes = write(fd, buf, bufsize); if (nbytes != (ssize_t)bufsize) { emergency("write: %m"); close(fd); return (-1); } error = close(fd); if (error != 0) { emergency("close: %m"); return (-1); } return (0); } static int mount_tmpfs(const char *fspath) { struct iovec *iov; char errmsg[255]; int error, iovlen; iov = NULL; iovlen = 0; memset(errmsg, 0, sizeof(errmsg)); build_iovec(&iov, &iovlen, "fstype", __DECONST(void *, "tmpfs"), (size_t)-1); build_iovec(&iov, &iovlen, "fspath", __DECONST(void *, fspath), (size_t)-1); build_iovec(&iov, &iovlen, "errmsg", errmsg, sizeof(errmsg)); error = nmount(iov, iovlen, 0); if (error != 0) { if (*errmsg != '\0') { emergency("cannot mount tmpfs on %s: %s: %m", fspath, errmsg); } else { emergency("cannot mount tmpfs on %s: %m", fspath); } return (error); } return (0); } static state_func_t reroot(void) { void *buf; size_t bufsize; int error; buf = NULL; bufsize = 0; revoke_ttys(); runshutdown(); /* * Make sure nobody can interfere with our scheme. * Ignore ESRCH, which can apparently happen when * there are no processes to kill. */ error = kill(-1, SIGKILL); if (error != 0 && errno != ESRCH) { emergency("kill(2) failed: %m"); goto out; } /* * Copy the init binary into tmpfs, so that we can unmount * the old rootfs without committing suicide. */ error = read_file(init_path_argv0, &buf, &bufsize); if (error != 0) goto out; error = mount_tmpfs(_PATH_REROOT); if (error != 0) goto out; error = create_file(_PATH_REROOT_INIT, buf, bufsize); if (error != 0) goto out; /* * Execute the temporary init. */ execl(_PATH_REROOT_INIT, _PATH_REROOT_INIT, "-r", NULL); emergency("cannot exec %s: %m", _PATH_REROOT_INIT); out: emergency("reroot failed; going to single user mode"); free(buf); return (state_func_t) single_user; } static state_func_t reroot_phase_two(void) { char init_path[PATH_MAX], *path, *path_component; size_t init_path_len; int nbytes, error; /* * Ask the kernel to mount the new rootfs. */ error = reboot(RB_REROOT); if (error != 0) { emergency("RB_REBOOT failed: %m"); goto out; } /* * Figure out where the destination init(8) binary is. Note that * the path could be different than what we've started with. Use * the value from kenv, if set, or the one from sysctl otherwise. * The latter defaults to a hardcoded value, but can be overridden * by a build time option. */ nbytes = kenv(KENV_GET, "init_path", init_path, sizeof(init_path)); if (nbytes <= 0) { init_path_len = sizeof(init_path); error = sysctlbyname("kern.init_path", init_path, &init_path_len, NULL, 0); if (error != 0) { emergency("failed to retrieve kern.init_path: %m"); goto out; } } /* * Repeat the init search logic from sys/kern/init_path.c */ path_component = init_path; while ((path = strsep(&path_component, ":")) != NULL) { /* * Execute init(8) from the new rootfs. */ execl(path, path, NULL); } emergency("cannot exec init from %s: %m", init_path); out: emergency("reroot failed; going to single user mode"); return (state_func_t) single_user; } /* * Bring the system up single user. */ static state_func_t single_user(void) { pid_t pid, wpid; int status; sigset_t mask; const char *shell; char *argv[2]; struct timeval tv, tn; #ifdef SECURE struct ttyent *typ; struct passwd *pp; static const char banner[] = "Enter root password, or ^D to go multi-user\n"; char *clear, *password; #endif #ifdef DEBUGSHELL char altshell[128]; #endif if (Reboot) { /* Instead of going single user, let's reboot the machine */ sync(); if (reboot(howto) == -1) { emergency("reboot(%#x) failed, %m", howto); _exit(1); /* panic and reboot */ } warning("reboot(%#x) returned", howto); _exit(0); /* panic as well */ } shell = get_shell(); if ((pid = fork()) == 0) { /* * Start the single user session. */ open_console(); #ifdef SECURE /* * Check the root password. * We don't care if the console is 'on' by default; * it's the only tty that can be 'off' and 'secure'. */ typ = getttynam("console"); pp = getpwnam("root"); if (typ && (typ->ty_status & TTY_SECURE) == 0 && pp && *pp->pw_passwd) { write_stderr(banner); for (;;) { clear = getpass("Password:"); if (clear == NULL || *clear == '\0') _exit(0); password = crypt(clear, pp->pw_passwd); bzero(clear, _PASSWORD_LEN); if (password != NULL && strcmp(password, pp->pw_passwd) == 0) break; warning("single-user login failed\n"); } } endttyent(); endpwent(); #endif /* SECURE */ #ifdef DEBUGSHELL { char *cp = altshell; int num; #define SHREQUEST "Enter full pathname of shell or RETURN for " write_stderr(SHREQUEST); write_stderr(shell); write_stderr(": "); while ((num = read(STDIN_FILENO, cp, 1)) != -1 && num != 0 && *cp != '\n' && cp < &altshell[127]) cp++; *cp = '\0'; if (altshell[0] != '\0') shell = altshell; } #endif /* DEBUGSHELL */ /* * Unblock signals. * We catch all the interesting ones, * and those are reset to SIG_DFL on exec. */ sigemptyset(&mask); sigprocmask(SIG_SETMASK, &mask, NULL); /* * Fire off a shell. * If the default one doesn't work, try the Bourne shell. */ char name[] = "-sh"; argv[0] = name; argv[1] = NULL; execv(shell, argv); emergency("can't exec %s for single user: %m", shell); execv(_PATH_BSHELL, argv); emergency("can't exec %s for single user: %m", _PATH_BSHELL); sleep(STALL_TIMEOUT); _exit(1); } if (pid == -1) { /* * We are seriously hosed. Do our best. */ emergency("can't fork single-user shell, trying again"); while (waitpid(-1, (int *) 0, WNOHANG) > 0) continue; return (state_func_t) single_user; } requested_transition = 0; do { if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) collect_child(wpid); if (wpid == -1) { if (errno == EINTR) continue; warning("wait for single-user shell failed: %m; restarting"); return (state_func_t) single_user; } if (wpid == pid && WIFSTOPPED(status)) { warning("init: shell stopped, restarting\n"); kill(pid, SIGCONT); wpid = -1; } } while (wpid != pid && !requested_transition); if (requested_transition) return (state_func_t) requested_transition; if (!WIFEXITED(status)) { if (WTERMSIG(status) == SIGKILL) { /* * reboot(8) killed shell? */ warning("single user shell terminated."); gettimeofday(&tv, NULL); tn = tv; tv.tv_sec += STALL_TIMEOUT; while (tv.tv_sec > tn.tv_sec || (tv.tv_sec == tn.tv_sec && tv.tv_usec > tn.tv_usec)) { sleep(1); gettimeofday(&tn, NULL); } _exit(0); } else { warning("single user shell terminated, restarting"); return (state_func_t) single_user; } } runcom_mode = FASTBOOT; return (state_func_t) runcom; } /* * Run the system startup script. */ static state_func_t runcom(void) { state_func_t next_transition; if ((next_transition = run_script(_PATH_RUNCOM)) != NULL) return next_transition; runcom_mode = AUTOBOOT; /* the default */ return (state_func_t) read_ttys; } static void execute_script(char *argv[]) { struct sigaction sa; const char *shell, *script; int error; bzero(&sa, sizeof(sa)); sigemptyset(&sa.sa_mask); sa.sa_handler = SIG_IGN; sigaction(SIGTSTP, &sa, NULL); sigaction(SIGHUP, &sa, NULL); open_console(); sigprocmask(SIG_SETMASK, &sa.sa_mask, NULL); #ifdef LOGIN_CAP setprocresources(RESOURCE_RC); #endif /* * Try to directly execute the script first. If it * fails, try the old method of passing the script path * to sh(1). Don't complain if it fails because of * the missing execute bit. */ script = argv[1]; error = access(script, X_OK); if (error == 0) { execv(script, argv + 1); warning("can't directly exec %s: %m", script); } else if (errno != EACCES) { warning("can't access %s: %m", script); } shell = get_shell(); execv(shell, argv); stall("can't exec %s for %s: %m", shell, script); } /* * Execute binary, replacing init(8) as PID 1. */ static void replace_init(char *path) { char *argv[3]; char sh[] = "sh"; argv[0] = sh; argv[1] = path; argv[2] = NULL; execute_script(argv); } /* * Run a shell script. * Returns 0 on success, otherwise the next transition to enter: * - single_user if fork/execv/waitpid failed, or if the script * terminated with a signal or exit code != 0. * - death_single if a SIGTERM was delivered to init(8). */ static state_func_t run_script(const char *script) { pid_t pid, wpid; int status; char *argv[4]; const char *shell; shell = get_shell(); if ((pid = fork()) == 0) { char _sh[] = "sh"; char _autoboot[] = "autoboot"; argv[0] = _sh; argv[1] = __DECONST(char *, script); argv[2] = runcom_mode == AUTOBOOT ? _autoboot : 0; argv[3] = NULL; execute_script(argv); sleep(STALL_TIMEOUT); _exit(1); /* force single user mode */ } if (pid == -1) { emergency("can't fork for %s on %s: %m", shell, script); while (waitpid(-1, (int *) 0, WNOHANG) > 0) continue; sleep(STALL_TIMEOUT); return (state_func_t) single_user; } /* * Copied from single_user(). This is a bit paranoid. */ requested_transition = 0; do { if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) collect_child(wpid); if (wpid == -1) { if (requested_transition == death_single || requested_transition == reroot) return (state_func_t) requested_transition; if (errno == EINTR) continue; warning("wait for %s on %s failed: %m; going to " "single user mode", shell, script); return (state_func_t) single_user; } if (wpid == pid && WIFSTOPPED(status)) { warning("init: %s on %s stopped, restarting\n", shell, script); kill(pid, SIGCONT); wpid = -1; } } while (wpid != pid); if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && requested_transition == catatonia) { /* /etc/rc executed /sbin/reboot; wait for the end quietly */ sigset_t s; sigfillset(&s); for (;;) sigsuspend(&s); } if (!WIFEXITED(status)) { warning("%s on %s terminated abnormally, going to single " "user mode", shell, script); return (state_func_t) single_user; } if (WEXITSTATUS(status)) return (state_func_t) single_user; return (state_func_t) 0; } /* * Open the session database. * * NB: We could pass in the size here; is it necessary? */ static int start_session_db(void) { if (session_db && (*session_db->close)(session_db)) emergency("session database close: %m"); if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == NULL) { 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; 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. */ 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); } /* * Look up a login session by pid. */ static session_t * find_session(pid_t pid) { DBT key; DBT data; session_t *ret; key.data = &pid; key.size = sizeof pid; if ((*session_db->get)(session_db, &key, &data, 0) != 0) return 0; bcopy(data.data, (char *)&ret, sizeof(ret)); return ret; } /* * Construct an argument vector from a command line. */ static char ** construct_argv(char *command) { int argc = 0; char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1) * sizeof (char *)); if ((argv[argc++] = strk(command)) == NULL) { free(argv); return (NULL); } while ((argv[argc++] = strk((char *) 0)) != NULL) continue; return argv; } /* * Deallocate a session descriptor. */ static void free_session(session_t *sp) { free(sp->se_device); if (sp->se_getty) { free(sp->se_getty); free(sp->se_getty_argv_space); free(sp->se_getty_argv); } if (sp->se_window) { free(sp->se_window); free(sp->se_window_argv_space); free(sp->se_window_argv); } if (sp->se_type) free(sp->se_type); free(sp); } /* * Allocate a new session descriptor. * Mark it SE_PRESENT. */ static session_t * new_session(session_t *sprev, 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 *) calloc(1, sizeof (session_t)); sp->se_flags |= SE_PRESENT; if ((typ->ty_status & TTY_IFEXISTS) != 0) sp->se_flags |= SE_IFEXISTS; if ((typ->ty_status & TTY_IFCONSOLE) != 0) sp->se_flags |= SE_IFCONSOLE; if (asprintf(&sp->se_device, "%s%s", _PATH_DEV, typ->ty_name) < 0) err(1, "asprintf"); if (setupargv(sp, typ) == 0) { free_session(sp); return (0); } sp->se_next = 0; if (sprev == NULL) { sessions = sp; sp->se_prev = 0; } else { sprev->se_next = sp; sp->se_prev = sprev; } return sp; } /* * Calculate getty and if useful window argv vectors. */ static int setupargv(session_t *sp, struct ttyent *typ) { if (sp->se_getty) { free(sp->se_getty); free(sp->se_getty_argv_space); free(sp->se_getty_argv); } if (asprintf(&sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name) < 0) err(1, "asprintf"); sp->se_getty_argv_space = strdup(sp->se_getty); sp->se_getty_argv = construct_argv(sp->se_getty_argv_space); if (sp->se_getty_argv == NULL) { warning("can't parse getty for port %s", sp->se_device); free(sp->se_getty); free(sp->se_getty_argv_space); sp->se_getty = sp->se_getty_argv_space = 0; return (0); } if (sp->se_window) { free(sp->se_window); free(sp->se_window_argv_space); free(sp->se_window_argv); } sp->se_window = sp->se_window_argv_space = 0; sp->se_window_argv = 0; if (typ->ty_window) { sp->se_window = strdup(typ->ty_window); sp->se_window_argv_space = strdup(sp->se_window); sp->se_window_argv = construct_argv(sp->se_window_argv_space); if (sp->se_window_argv == NULL) { warning("can't parse window for port %s", sp->se_device); free(sp->se_window_argv_space); free(sp->se_window); sp->se_window = sp->se_window_argv_space = 0; return (0); } } if (sp->se_type) free(sp->se_type); sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0; return (1); } /* * Walk the list of ttys and create sessions for each active line. */ static state_func_t read_ttys(void) { 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) { snext = sp->se_next; free_session(sp); } sessions = 0; if (start_session_db()) return (state_func_t) single_user; /* * Allocate a session entry for each active port. * Note that sp starts at 0. */ while ((typ = getttyent()) != NULL) if ((snext = new_session(sp, typ)) != NULL) sp = snext; endttyent(); return (state_func_t) multi_user; } /* * Start a window system running. */ static void start_window_system(session_t *sp) { pid_t pid; sigset_t mask; char term[64], *env[2]; int status; if ((pid = fork()) == -1) { emergency("can't fork for window system on port %s: %m", sp->se_device); /* hope that getty fails and we can try again */ return; } if (pid) { waitpid(-1, &status, 0); return; } /* reparent window process to the init to not make a zombie on exit */ if ((pid = fork()) == -1) { emergency("can't fork for window system on port %s: %m", sp->se_device); _exit(1); } if (pid) _exit(0); sigemptyset(&mask); sigprocmask(SIG_SETMASK, &mask, NULL); if (setsid() < 0) emergency("setsid failed (window) %m"); #ifdef LOGIN_CAP setprocresources(RESOURCE_WINDOW); #endif if (sp->se_type) { /* Don't use malloc after fork */ strcpy(term, "TERM="); strlcat(term, sp->se_type, sizeof(term)); env[0] = term; env[1] = NULL; } else env[0] = NULL; execve(sp->se_window_argv[0], sp->se_window_argv, env); stall("can't exec window system '%s' for port %s: %m", sp->se_window_argv[0], sp->se_device); _exit(1); } /* * Start a login session running. */ static pid_t start_getty(session_t *sp) { pid_t pid; sigset_t mask; time_t current_time = time((time_t *) 0); int too_quick = 0; char term[64], *env[2]; if (current_time >= sp->se_started && current_time - sp->se_started < GETTY_SPACING) { if (++sp->se_nspace > GETTY_NSPACE) { sp->se_nspace = 0; too_quick = 1; } } else sp->se_nspace = 0; /* * fork(), not vfork() -- we can't afford to block. */ if ((pid = fork()) == -1) { emergency("can't fork for getty on port %s: %m", sp->se_device); return -1; } if (pid) return pid; if (too_quick) { warning("getty repeating too quickly on port %s, sleeping %d secs", sp->se_device, GETTY_SLEEP); sleep((unsigned) GETTY_SLEEP); } if (sp->se_window) { start_window_system(sp); sleep(WINDOW_WAIT); } sigemptyset(&mask); sigprocmask(SIG_SETMASK, &mask, NULL); #ifdef LOGIN_CAP setprocresources(RESOURCE_GETTY); #endif if (sp->se_type) { /* Don't use malloc after fork */ strcpy(term, "TERM="); strlcat(term, sp->se_type, sizeof(term)); env[0] = term; env[1] = NULL; } else env[0] = NULL; execve(sp->se_getty_argv[0], sp->se_getty_argv, env); stall("can't exec getty '%s' for port %s: %m", sp->se_getty_argv[0], sp->se_device); _exit(1); } /* * Return 1 if the session is defined as "onifexists" * or "onifconsole" and the device node does not exist. */ static int session_has_no_tty(session_t *sp) { int fd; if ((sp->se_flags & SE_IFEXISTS) == 0 && (sp->se_flags & SE_IFCONSOLE) == 0) return (0); fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0); if (fd < 0) { if (errno == ENOENT) return (1); return (0); } close(fd); return (0); } /* * Collect exit status for a child. * If an exiting login, start a new login running. */ static void collect_child(pid_t pid) { session_t *sp, *sprev, *snext; if (! sessions) return; if (! (sp = find_session(pid))) return; del_session(sp); sp->se_process = 0; if (sp->se_flags & SE_SHUTDOWN || session_has_no_tty(sp)) { if ((sprev = sp->se_prev) != NULL) sprev->se_next = sp->se_next; else sessions = sp->se_next; if ((snext = sp->se_next) != NULL) snext->se_prev = sp->se_prev; free_session(sp); return; } if ((pid = start_getty(sp)) == -1) { /* serious trouble */ requested_transition = clean_ttys; return; } sp->se_process = pid; sp->se_started = time((time_t *) 0); add_session(sp); } /* * Catch a signal and request a state transition. */ static void transition_handler(int sig) { switch (sig) { case SIGHUP: if (current_state == read_ttys || current_state == multi_user || current_state == clean_ttys || current_state == catatonia) requested_transition = clean_ttys; break; case SIGUSR2: howto = RB_POWEROFF; case SIGUSR1: howto |= RB_HALT; case SIGWINCH: case SIGINT: if (sig == SIGWINCH) howto |= RB_POWERCYCLE; Reboot = TRUE; case SIGTERM: if (current_state == read_ttys || current_state == multi_user || current_state == clean_ttys || current_state == catatonia) requested_transition = death; else requested_transition = death_single; break; case SIGTSTP: if (current_state == runcom || current_state == read_ttys || current_state == clean_ttys || current_state == multi_user || current_state == catatonia) requested_transition = catatonia; break; case SIGEMT: requested_transition = reroot; break; default: requested_transition = 0; break; } } /* * Take the system multiuser. */ static state_func_t multi_user(void) { pid_t pid; session_t *sp; requested_transition = 0; /* * If the administrator has not set the security level to -1 * to indicate that the kernel should not run multiuser in secure * mode, and the run script has not set a higher level of security * than level 1, then put the kernel into secure mode. */ if (getsecuritylevel() == 0) setsecuritylevel(1); for (sp = sessions; sp; sp = sp->se_next) { if (sp->se_process) continue; if (session_has_no_tty(sp)) continue; if ((pid = start_getty(sp)) == -1) { /* serious trouble */ requested_transition = clean_ttys; break; } sp->se_process = pid; sp->se_started = time((time_t *) 0); add_session(sp); } while (!requested_transition) if ((pid = waitpid(-1, (int *) 0, 0)) != -1) collect_child(pid); return (state_func_t) requested_transition; } /* * This is an (n*2)+(n^2) algorithm. We hope it isn't run often... */ static state_func_t clean_ttys(void) { session_t *sp, *sprev; struct ttyent *typ; int devlen; char *old_getty, *old_window, *old_type; /* * mark all sessions for death, (!SE_PRESENT) * as we find or create new ones they'll be marked as keepers, * we'll later nuke all the ones not found in /etc/ttys */ for (sp = sessions; sp != NULL; sp = sp->se_next) sp->se_flags &= ~SE_PRESENT; devlen = sizeof(_PATH_DEV) - 1; while ((typ = getttyent()) != NULL) { for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next) if (strcmp(typ->ty_name, sp->se_device + devlen) == 0) break; if (sp) { /* we want this one to live */ sp->se_flags |= SE_PRESENT; if ((typ->ty_status & TTY_ON) == 0 || typ->ty_getty == 0) { sp->se_flags |= SE_SHUTDOWN; kill(sp->se_process, SIGHUP); continue; } sp->se_flags &= ~SE_SHUTDOWN; old_getty = sp->se_getty ? strdup(sp->se_getty) : 0; old_window = sp->se_window ? strdup(sp->se_window) : 0; old_type = sp->se_type ? strdup(sp->se_type) : 0; if (setupargv(sp, typ) == 0) { warning("can't parse getty for port %s", sp->se_device); sp->se_flags |= SE_SHUTDOWN; kill(sp->se_process, SIGHUP); } else if ( !old_getty || (!old_type && sp->se_type) || (old_type && !sp->se_type) || (!old_window && sp->se_window) || (old_window && !sp->se_window) || (strcmp(old_getty, sp->se_getty) != 0) || (old_window && strcmp(old_window, sp->se_window) != 0) || (old_type && strcmp(old_type, sp->se_type) != 0) ) { /* Don't set SE_SHUTDOWN here */ sp->se_nspace = 0; sp->se_started = 0; kill(sp->se_process, SIGHUP); } if (old_getty) free(old_getty); if (old_window) free(old_window); if (old_type) free(old_type); continue; } new_session(sprev, typ); } endttyent(); /* * sweep through and kill all deleted sessions * ones who's /etc/ttys line was deleted (SE_PRESENT unset) */ for (sp = sessions; sp != NULL; sp = sp->se_next) { if ((sp->se_flags & SE_PRESENT) == 0) { sp->se_flags |= SE_SHUTDOWN; kill(sp->se_process, SIGHUP); } } return (state_func_t) multi_user; } /* * Block further logins. */ static state_func_t catatonia(void) { session_t *sp; for (sp = sessions; sp; sp = sp->se_next) sp->se_flags |= SE_SHUTDOWN; return (state_func_t) multi_user; } /* * Note SIGALRM. */ static void alrm_handler(int sig) { (void)sig; clang = 1; } /* * Bring the system down to single user. */ static state_func_t death(void) { int block, blocked; size_t len; /* Temporarily block suspend. */ len = sizeof(blocked); block = 1; if (sysctlbyname("kern.suspend_blocked", &blocked, &len, &block, sizeof(block)) == -1) blocked = 0; /* * Also revoke the TTY here. Because runshutdown() may reopen * the TTY whose getty we're killing here, there is no guarantee * runshutdown() will perform the initial open() call, causing * the terminal attributes to be misconfigured. */ revoke_ttys(); /* Try to run the rc.shutdown script within a period of time */ runshutdown(); /* Unblock suspend if we blocked it. */ if (!blocked) sysctlbyname("kern.suspend_blocked", NULL, NULL, &blocked, sizeof(blocked)); return (state_func_t) death_single; } /* * Do what is necessary to reinitialize single user mode or reboot * from an incomplete state. */ static state_func_t death_single(void) { int i; pid_t pid; static const int death_sigs[2] = { SIGTERM, SIGKILL }; revoke(_PATH_CONSOLE); for (i = 0; i < 2; ++i) { if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH) return (state_func_t) single_user; clang = 0; alarm(DEATH_WATCH); do if ((pid = waitpid(-1, (int *)0, 0)) != -1) collect_child(pid); while (clang == 0 && errno != ECHILD); if (errno == ECHILD) return (state_func_t) single_user; } warning("some processes would not die; ps axl advised"); return (state_func_t) single_user; } static void revoke_ttys(void) { session_t *sp; for (sp = sessions; sp; sp = sp->se_next) { sp->se_flags |= SE_SHUTDOWN; kill(sp->se_process, SIGHUP); revoke(sp->se_device); } } /* * Run the system shutdown script. * * Exit codes: XXX I should document more * -2 shutdown script terminated abnormally * -1 fatal error - can't run script * 0 good. * >0 some error (exit code) */ static int runshutdown(void) { pid_t pid, wpid; int status; int shutdowntimeout; size_t len; char *argv[4]; struct stat sb; /* * rc.shutdown is optional, so to prevent any unnecessary * complaints from the shell we simply don't run it if the * file does not exist. If the stat() here fails for other * reasons, we'll let the shell complain. */ if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT) return 0; if ((pid = fork()) == 0) { char _sh[] = "sh"; char _reboot[] = "reboot"; char _single[] = "single"; char _path_rundown[] = _PATH_RUNDOWN; argv[0] = _sh; argv[1] = _path_rundown; argv[2] = Reboot ? _reboot : _single; argv[3] = NULL; execute_script(argv); _exit(1); /* force single user mode */ } if (pid == -1) { emergency("can't fork for %s: %m", _PATH_RUNDOWN); while (waitpid(-1, (int *) 0, WNOHANG) > 0) continue; sleep(STALL_TIMEOUT); return -1; } len = sizeof(shutdowntimeout); if (sysctlbyname("kern.init_shutdown_timeout", &shutdowntimeout, &len, NULL, 0) == -1 || shutdowntimeout < 2) shutdowntimeout = DEATH_SCRIPT; alarm(shutdowntimeout); clang = 0; /* * Copied from single_user(). This is a bit paranoid. * Use the same ALRM handler. */ do { if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) collect_child(wpid); if (clang == 1) { /* we were waiting for the sub-shell */ kill(wpid, SIGTERM); warning("timeout expired for %s: %m; going to " "single user mode", _PATH_RUNDOWN); return -1; } if (wpid == -1) { if (errno == EINTR) continue; warning("wait for %s failed: %m; going to " "single user mode", _PATH_RUNDOWN); return -1; } if (wpid == pid && WIFSTOPPED(status)) { warning("init: %s stopped, restarting\n", _PATH_RUNDOWN); kill(pid, SIGCONT); wpid = -1; } } while (wpid != pid && !clang); /* Turn off the alarm */ alarm(0); if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && requested_transition == catatonia) { /* * /etc/rc.shutdown executed /sbin/reboot; * wait for the end quietly */ sigset_t s; sigfillset(&s); for (;;) sigsuspend(&s); } if (!WIFEXITED(status)) { warning("%s terminated abnormally, going to " "single user mode", _PATH_RUNDOWN); return -2; } if ((status = WEXITSTATUS(status)) != 0) warning("%s returned status %d", _PATH_RUNDOWN, status); return status; } static char * strk(char *p) { static char *t; char *q; int c; if (p) t = p; if (!t) return 0; c = *t; while (c == ' ' || c == '\t' ) c = *++t; if (!c) { t = 0; return 0; } q = t; if (c == '\'') { c = *++t; q = t; while (c && c != '\'') c = *++t; if (!c) /* unterminated string */ q = t = 0; else *t++ = 0; } else { while (c && c != ' ' && c != '\t' ) c = *++t; *t++ = 0; if (!c) t = 0; } return q; } #ifdef LOGIN_CAP static void setprocresources(const char *cname) { login_cap_t *lc; if ((lc = login_getclassbyname(cname, NULL)) != NULL) { setusercontext(lc, (struct passwd*)NULL, 0, LOGIN_SETENV | LOGIN_SETPRIORITY | LOGIN_SETRESOURCES | LOGIN_SETLOGINCLASS | LOGIN_SETCPUMASK); login_close(lc); } } #endif
Upload File
Create Folder