static void edit_file(const struct passwd *pas, const char *file)
{
const char *ptr;
pid_t pid;
pid = xvfork();
if (pid) { /* parent */
wait4pid(pid);
return;
}
/* CHILD - change user and run editor */
/* initgroups, setgid, setuid */
change_identity(pas);
setup_environment(pas->pw_shell,
SETUP_ENV_CHANGEENV | SETUP_ENV_TO_TMP,
pas);
ptr = getenv("VISUAL");
if (!ptr) {
ptr = getenv("EDITOR");
if (!ptr)
ptr = "vi";
}
BB_EXECLP(ptr, ptr, file, NULL);
bb_perror_msg_and_die("can't execute '%s'", ptr);
}
void FAST_FUNC launch_helper(const char **argv)
{
// setup vanilla unidirectional pipes interchange
int i;
int pipes[4];
xpipe(pipes);
xpipe(pipes + 2);
// NB: handler must be installed before vfork
bb_signals(0
+ (1 << SIGCHLD)
+ (1 << SIGALRM)
, signal_handler);
G.helper_pid = xvfork();
i = (!G.helper_pid) * 2; // for parent:0, for child:2
close(pipes[i + 1]); // 1 or 3 - closing one write end
close(pipes[2 - i]); // 2 or 0 - closing one read end
xmove_fd(pipes[i], STDIN_FILENO); // 0 or 2 - using other read end
xmove_fd(pipes[3 - i], STDOUT_FILENO); // 3 or 1 - other write end
if (!G.helper_pid) {
// child: try to execute connection helper
// NB: SIGCHLD & SIGALRM revert to SIG_DFL on exec
BB_EXECVP_or_die((char**)argv);
}
// parent
// check whether child is alive
//redundant:signal_handler(SIGCHLD);
// child seems OK -> parent goes on
atexit(kill_helper);
}
pid_t FAST_FUNC fork_or_rexec(char **argv)
{
pid_t pid;
/* Maybe we are already re-execed and come here again? */
if (re_execed)
return 0;
pid = xvfork();
if (pid) /* parent */
return pid;
/* child - re-exec ourself */
re_exec(argv);
}
void FAST_FUNC open_transformer(int fd, const char *transform_prog)
#endif
{
struct fd_pair fd_pipe;
int pid;
xpiped_pair(fd_pipe);
pid = BB_MMU ? xfork() : xvfork();
if (pid == 0) {
/* Child */
close(fd_pipe.rd); /* we don't want to read from the parent */
// FIXME: error check?
#if BB_MMU
{
transformer_aux_data_t aux;
init_transformer_aux_data(&aux);
aux.check_signature = check_signature;
transformer(&aux, fd, fd_pipe.wr);
if (ENABLE_FEATURE_CLEAN_UP) {
close(fd_pipe.wr); /* send EOF */
close(fd);
}
/* must be _exit! bug was actually seen here */
_exit(EXIT_SUCCESS);
}
#else
{
char *argv[4];
xmove_fd(fd, 0);
xmove_fd(fd_pipe.wr, 1);
argv[0] = (char*)transform_prog;
argv[1] = (char*)"-cf";
argv[2] = (char*)"-";
argv[3] = NULL;
BB_EXECVP(transform_prog, argv);
bb_perror_msg_and_die("can't execute '%s'", transform_prog);
}
#endif
/* notreached */
}
/* parent process */
close(fd_pipe.wr); /* don't want to write to the child */
xmove_fd(fd_pipe.rd, fd);
}
static int open_as_user(const struct passwd *pas, const char *file)
{
pid_t pid;
char c;
pid = xvfork();
if (pid) { /* PARENT */
if (wait4pid(pid) == 0) {
/* exitcode 0: child says it can read */
return open(file, O_RDONLY);
}
return -1;
}
/* CHILD */
/* initgroups, setgid, setuid */
change_identity(pas);
/* We just try to read one byte. If it works, file is readable
* under this user. We signal that by exiting with 0. */
_exit(safe_read(xopen(file, O_RDONLY), &c, 1) < 0);
}
void FAST_FUNC launch_helper(const char **argv)
{
// setup vanilla unidirectional pipes interchange
int i;
int pipes[4];
xpipe(pipes);
xpipe(pipes + 2);
// NB: handler must be installed before vfork
bb_signals(0
+ (1 << SIGCHLD)
+ (1 << SIGALRM)
, signal_handler);
G.helper_pid = xvfork();
i = (!G.helper_pid) * 2; // for parent:0, for child:2
close(pipes[i + 1]); // 1 or 3 - closing one write end
close(pipes[2 - i]); // 2 or 0 - closing one read end
xmove_fd(pipes[i], STDIN_FILENO); // 0 or 2 - using other read end
xmove_fd(pipes[3 - i], STDOUT_FILENO); // 3 or 1 - using other write end
// End result:
// parent stdout [3] -> child stdin [2]
// child stdout [1] -> parent stdin [0]
if (!G.helper_pid) {
// child
// if parent dies, get SIGTERM
prctl(PR_SET_PDEATHSIG, SIGTERM, 0, 0, 0);
// try to execute connection helper
// NB: SIGCHLD & SIGALRM revert to SIG_DFL on exec
BB_EXECVP_or_die((char**)argv);
}
// parent goes on
}
/* Run command CMD and return statistics on it.
Put the statistics in *RESP. */
static void run_command(char *const *cmd, resource_t *resp)
{
pid_t pid;
void (*interrupt_signal)(int);
void (*quit_signal)(int);
resp->elapsed_ms = monotonic_ms();
pid = xvfork();
if (pid == 0) {
/* Child */
BB_EXECVP_or_die((char**)cmd);
}
/* Have signals kill the child but not self (if possible). */
//TODO: just block all sigs? and reenable them in the very end in main?
interrupt_signal = signal(SIGINT, SIG_IGN);
quit_signal = signal(SIGQUIT, SIG_IGN);
resuse_end(pid, resp);
/* Re-enable signals. */
signal(SIGINT, interrupt_signal);
signal(SIGQUIT, quit_signal);
}
int start_stop_daemon_main(int argc UNUSED_PARAM, char **argv)
{
unsigned opt;
char *signame;
char *startas;
char *chuid;
#if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
// char *retry_arg = NULL;
// int retries = -1;
char *opt_N;
#endif
INIT_G();
opt = GETOPT32(argv, "^"
"KSbqtma:n:s:u:c:x:p:"
IF_FEATURE_START_STOP_DAEMON_FANCY("ovN:R:")
/* -K or -S is required; they are mutually exclusive */
/* -p is required if -m is given */
/* -xpun (at least one) is required if -K is given */
/* -xa (at least one) is required if -S is given */
/* -q turns off -v */
"\0"
"K:S:K--S:S--K:m?p:K?xpun:S?xa"
IF_FEATURE_START_STOP_DAEMON_FANCY("q-v"),
LONGOPTS
&startas, &cmdname, &signame, &userspec, &chuid, &execname, &pidfile
IF_FEATURE_START_STOP_DAEMON_FANCY(,&opt_N)
/* We accept and ignore -R <param> / --retry <param> */
IF_FEATURE_START_STOP_DAEMON_FANCY(,NULL)
);
if (opt & OPT_s) {
signal_nr = get_signum(signame);
if (signal_nr < 0) bb_show_usage();
}
if (!(opt & OPT_a))
startas = execname;
if (!execname) /* in case -a is given and -x is not */
execname = startas;
if (execname) {
G.execname_sizeof = strlen(execname) + 1;
G.execname_cmpbuf = xmalloc(G.execname_sizeof + 1);
}
// IF_FEATURE_START_STOP_DAEMON_FANCY(
// if (retry_arg)
// retries = xatoi_positive(retry_arg);
// )
//argc -= optind;
argv += optind;
if (userspec) {
user_id = bb_strtou(userspec, NULL, 10);
if (errno)
user_id = xuname2uid(userspec);
}
/* Both start and stop need to know current processes */
do_procinit();
if (opt & CTX_STOP) {
int i = do_stop();
return (opt & OPT_OKNODO) ? 0 : (i <= 0);
}
if (G.found_procs) {
if (!QUIET)
printf("%s is already running\n%u\n", execname, (unsigned)G.found_procs->pid);
return !(opt & OPT_OKNODO);
}
#ifdef OLDER_VERSION_OF_X
if (execname)
xstat(execname, &G.execstat);
#endif
*--argv = startas;
if (opt & OPT_BACKGROUND) {
#if BB_MMU
bb_daemonize(DAEMON_DEVNULL_STDIO + DAEMON_CLOSE_EXTRA_FDS + DAEMON_DOUBLE_FORK);
/* DAEMON_DEVNULL_STDIO is superfluous -
* it's always done by bb_daemonize() */
#else
/* Daemons usually call bb_daemonize_or_rexec(), but SSD can do
* without: SSD is not itself a daemon, it _execs_ a daemon.
* The usual NOMMU problem of "child can't run indefinitely,
* it must exec" does not bite us: we exec anyway.
*/
pid_t pid = xvfork();
if (pid != 0) {
/* parent */
/* why _exit? the child may have changed the stack,
* so "return 0" may do bad things */
_exit(EXIT_SUCCESS);
}
/* Child */
setsid(); /* detach from controlling tty */
/* Redirect stdio to /dev/null, close extra FDs */
bb_daemon_helper(DAEMON_DEVNULL_STDIO + DAEMON_CLOSE_EXTRA_FDS);
#endif
}
if (opt & OPT_MAKEPID) {
/* User wants _us_ to make the pidfile */
write_pidfile(pidfile);
}
if (opt & OPT_c) {
struct bb_uidgid_t ugid;
parse_chown_usergroup_or_die(&ugid, chuid);
if (ugid.uid != (uid_t) -1L) {
struct passwd *pw = xgetpwuid(ugid.uid);
if (ugid.gid != (gid_t) -1L)
pw->pw_gid = ugid.gid;
/* initgroups, setgid, setuid: */
change_identity(pw);
} else if (ugid.gid != (gid_t) -1L) {
xsetgid(ugid.gid);
setgroups(1, &ugid.gid);
}
}
#if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
if (opt & OPT_NICELEVEL) {
/* Set process priority */
int prio = getpriority(PRIO_PROCESS, 0) + xatoi_range(opt_N, INT_MIN/2, INT_MAX/2);
if (setpriority(PRIO_PROCESS, 0, prio) < 0) {
bb_perror_msg_and_die("setpriority(%d)", prio);
}
}
#endif
execvp(startas, argv);
bb_perror_msg_and_die("can't execute '%s'", startas);
}
void FAST_FUNC data_extract_to_command(archive_handle_t *archive_handle)
{
file_header_t *file_header = archive_handle->file_header;
#if 0 /* do we need this? ENABLE_FEATURE_TAR_SELINUX */
char *sctx = archive_handle->tar__sctx[PAX_NEXT_FILE];
if (!sctx)
sctx = archive_handle->tar__sctx[PAX_GLOBAL];
if (sctx) { /* setfscreatecon is 4 syscalls, avoid if possible */
setfscreatecon(sctx);
free(archive_handle->tar__sctx[PAX_NEXT_FILE]);
archive_handle->tar__sctx[PAX_NEXT_FILE] = NULL;
}
#endif
if ((file_header->mode & S_IFMT) == S_IFREG) {
pid_t pid;
int p[2], status;
char *tar_env[TAR_MAX];
memset(tar_env, 0, sizeof(tar_env));
xpipe(p);
pid = BB_MMU ? xfork() : xvfork();
if (pid == 0) {
/* Child */
/* str2env(tar_env, TAR_FILETYPE, "f"); - parent should do it once */
oct2env(tar_env, TAR_MODE, file_header->mode);
str2env(tar_env, TAR_FILENAME, file_header->name);
str2env(tar_env, TAR_REALNAME, file_header->name);
#if ENABLE_FEATURE_TAR_UNAME_GNAME
str2env(tar_env, TAR_UNAME, file_header->tar__uname);
str2env(tar_env, TAR_GNAME, file_header->tar__gname);
#endif
dec2env(tar_env, TAR_SIZE, file_header->size);
dec2env(tar_env, TAR_UID, file_header->uid);
dec2env(tar_env, TAR_GID, file_header->gid);
close(p[1]);
xdup2(p[0], STDIN_FILENO);
signal(SIGPIPE, SIG_DFL);
execl(archive_handle->tar__to_command_shell,
archive_handle->tar__to_command_shell,
"-c",
archive_handle->tar__to_command,
NULL);
bb_perror_msg_and_die("can't execute '%s'", archive_handle->tar__to_command_shell);
}
close(p[0]);
/* Our caller is expected to do signal(SIGPIPE, SIG_IGN)
* so that we don't die if child don't read all the input: */
bb_copyfd_exact_size(archive_handle->src_fd, p[1], -file_header->size);
close(p[1]);
if (safe_waitpid(pid, &status, 0) == -1)
bb_perror_msg_and_die("waitpid");
if (WIFEXITED(status) && WEXITSTATUS(status))
bb_error_msg_and_die("'%s' returned status %d",
archive_handle->tar__to_command, WEXITSTATUS(status));
if (WIFSIGNALED(status))
bb_error_msg_and_die("'%s' terminated on signal %d",
archive_handle->tar__to_command, WTERMSIG(status));
if (!BB_MMU) {
int i;
for (i = 0; i < TAR_MAX; i++) {
if (tar_env[i])
bb_unsetenv_and_free(tar_env[i]);
}
}
}
#if 0 /* ENABLE_FEATURE_TAR_SELINUX */
if (sctx)
/* reset the context after creating an entry */
setfscreatecon(NULL);
#endif
}
#include "unarchive.h"
/* transformer(), more than meets the eye */
/*
* On MMU machine, the transform_prog is removed by macro magic
* in include/unarchive.h. On NOMMU, transformer is removed.
*/
void FAST_FUNC open_transformer(int fd,
IF_DESKTOP(long long) int FAST_FUNC (*transformer)(int src_fd, int dst_fd),
const char *transform_prog)
{
struct fd_pair fd_pipe;
int pid;
xpiped_pair(fd_pipe);
pid = BB_MMU ? xfork() : xvfork();
if (pid == 0) {
/* Child */
close(fd_pipe.rd); /* we don't want to read from the parent */
// FIXME: error check?
#if BB_MMU
transformer(fd, fd_pipe.wr);
if (ENABLE_FEATURE_CLEAN_UP) {
close(fd_pipe.wr); /* send EOF */
close(fd);
}
/* must be _exit! bug was actually seen here */
_exit(EXIT_SUCCESS);
#else
{
char *argv[4];
int script_main(int argc UNUSED_PARAM, char **argv)
{
int opt;
int mode;
int child_pid;
int attr_ok; /* NB: 0: ok */
int winsz_ok;
int pty;
char pty_line[GETPTY_BUFSIZE];
struct termios tt, rtt;
struct winsize win;
const char *fname = "typescript";
const char *shell;
char shell_opt[] = "-i";
char *shell_arg = NULL;
enum {
OPT_a = (1 << 0),
OPT_c = (1 << 1),
OPT_f = (1 << 2),
OPT_q = (1 << 3),
OPT_t = (1 << 4),
};
#if ENABLE_LONG_OPTS
static const char getopt_longopts[] ALIGN1 =
"append\0" No_argument "a"
"command\0" Required_argument "c"
"flush\0" No_argument "f"
"quiet\0" No_argument "q"
IF_SCRIPTREPLAY("timing\0" No_argument "t")
;
applet_long_options = getopt_longopts;
#endif
opt_complementary = "?1"; /* max one arg */
opt = getopt32(argv, "ac:fq" IF_SCRIPTREPLAY("t") , &shell_arg);
//argc -= optind;
argv += optind;
if (argv[0]) {
fname = argv[0];
}
mode = O_CREAT|O_TRUNC|O_WRONLY;
if (opt & OPT_a) {
mode = O_CREAT|O_APPEND|O_WRONLY;
}
if (opt & OPT_c) {
shell_opt[1] = 'c';
}
if (!(opt & OPT_q)) {
printf("Script started, file is %s\n", fname);
}
shell = get_shell_name();
/* Some people run "script ... 0>&-".
* Our code assumes that STDIN_FILENO != pty.
* Ensure STDIN_FILENO is not closed:
*/
bb_sanitize_stdio();
pty = xgetpty(pty_line);
/* get current stdin's tty params */
attr_ok = tcgetattr(0, &tt);
winsz_ok = ioctl(0, TIOCGWINSZ, (char *)&win);
rtt = tt;
cfmakeraw(&rtt);
rtt.c_lflag &= ~ECHO;
tcsetattr(0, TCSAFLUSH, &rtt);
/* "script" from util-linux exits when child exits,
* we wouldn't wait for EOF from slave pty
* (output may be produced by grandchildren of child) */
signal(SIGCHLD, record_signo);
/* TODO: SIGWINCH? pass window size changes down to slave? */
child_pid = xvfork();
if (child_pid) {
/* parent */
#define buf bb_common_bufsiz1
struct pollfd pfd[2];
int outfd, count, loop;
double oldtime = ENABLE_SCRIPTREPLAY ? time(NULL) : 0;
smallint fd_count = 2;
outfd = xopen(fname, mode);
pfd[0].fd = pty;
pfd[0].events = POLLIN;
pfd[1].fd = STDIN_FILENO;
pfd[1].events = POLLIN;
ndelay_on(pty); /* this descriptor is not shared, can do this */
/* ndelay_on(STDIN_FILENO); - NO, stdin can be shared! Pity :( */
/* copy stdin to pty master input,
* copy pty master output to stdout and file */
/* TODO: don't use full_write's, use proper write buffering */
while (fd_count && !bb_got_signal) {
/* not safe_poll! we want SIGCHLD to EINTR poll */
if (poll(pfd, fd_count, -1) < 0 && errno != EINTR) {
/* If child exits too quickly, we may get EIO:
* for example, try "script -c true" */
break;
}
if (pfd[0].revents) {
errno = 0;
count = safe_read(pty, buf, sizeof(buf));
if (count <= 0 && errno != EAGAIN) {
/* err/eof from pty: exit */
goto restore;
}
if (count > 0) {
if (ENABLE_SCRIPTREPLAY && (opt & OPT_t)) {
struct timeval tv;
double newtime;
gettimeofday(&tv, NULL);
newtime = tv.tv_sec + (double) tv.tv_usec / 1000000;
fprintf(stderr, "%f %u\n", newtime - oldtime, count);
oldtime = newtime;
}
full_write(STDOUT_FILENO, buf, count);
full_write(outfd, buf, count);
if (opt & OPT_f) {
fsync(outfd);
}
}
}
if (pfd[1].revents) {
count = safe_read(STDIN_FILENO, buf, sizeof(buf));
if (count <= 0) {
/* err/eof from stdin: don't read stdin anymore */
pfd[1].revents = 0;
fd_count--;
} else {
full_write(pty, buf, count);
}
}
}
/* If loop was exited because SIGCHLD handler set bb_got_signal,
* there still can be some buffered output. But dont loop forever:
* we won't pump orphaned grandchildren's output indefinitely.
* Testcase: running this in script:
* exec dd if=/dev/zero bs=1M count=1
* must have "1+0 records in, 1+0 records out" captured too.
* (util-linux's script doesn't do this. buggy :) */
loop = 999;
/* pty is in O_NONBLOCK mode, we exit as soon as buffer is empty */
while (--loop && (count = safe_read(pty, buf, sizeof(buf))) > 0) {
full_write(STDOUT_FILENO, buf, count);
full_write(outfd, buf, count);
}
restore:
if (attr_ok == 0)
tcsetattr(0, TCSAFLUSH, &tt);
if (!(opt & OPT_q))
printf("Script done, file is %s\n", fname);
return EXIT_SUCCESS;
}
/* child: make pty slave to be input, output, error; run shell */
close(pty); /* close pty master */
/* open pty slave to fd 0,1,2 */
close(0);
xopen(pty_line, O_RDWR); /* uses fd 0 */
xdup2(0, 1);
xdup2(0, 2);
/* copy our original stdin tty's parameters to pty */
if (attr_ok == 0)
tcsetattr(0, TCSAFLUSH, &tt);
if (winsz_ok == 0)
ioctl(0, TIOCSWINSZ, (char *)&win);
/* set pty as a controlling tty */
setsid();
ioctl(0, TIOCSCTTY, 0 /* 0: don't forcibly steal */);
/* Non-ignored signals revert to SIG_DFL on exec anyway */
/*signal(SIGCHLD, SIG_DFL);*/
execl(shell, shell, shell_opt, shell_arg, (char *) NULL);
bb_simple_perror_msg_and_die(shell);
}
int timeout_main(int argc UNUSED_PARAM, char **argv)
{
int signo;
int status;
int parent = 0;
int timeout = 10;
pid_t pid;
#if !BB_MMU
char *sv1, *sv2;
#endif
const char *opt_s = "TERM";
/* -p option is not documented, it is needed to support NOMMU. */
/* -t SECONDS; -p PARENT_PID */
opt_complementary = "t+" USE_FOR_NOMMU(":p+");
/* '+': stop at first non-option */
getopt32(argv, "+s:t:" USE_FOR_NOMMU("p:"), &opt_s, &timeout, &parent);
/*argv += optind; - no, wait for bb_daemonize_or_rexec! */
signo = get_signum(opt_s);
if (signo < 0)
bb_error_msg_and_die("unknown signal '%s'", opt_s);
/* We want to create a grandchild which will watch
* and kill the grandparent. Other methods:
* making parent watch child disrupts parent<->child link
* (example: "tcpsvd 0.0.0.0 1234 timeout service_prog" -
* it's better if service_prog is a child of tcpsvd!),
* making child watch parent results in programs having
* unexpected children. */
if (parent) /* we were re-execed, already grandchild */
goto grandchild;
if (!argv[optind]) /* no PROG? */
bb_show_usage();
#if !BB_MMU
sv1 = argv[optind];
sv2 = argv[optind + 1];
#endif
pid = xvfork();
if (pid == 0) {
/* Child: spawn grandchild and exit */
parent = getppid();
#if !BB_MMU
argv[optind] = xasprintf("-p%u", parent);
argv[optind + 1] = NULL;
#endif
/* NB: exits with nonzero on error: */
bb_daemonize_or_rexec(0, argv);
/* Here we are grandchild. Sleep, then kill grandparent */
grandchild:
/* Just sleep(HUGE_NUM); kill(parent) may kill wrong process! */
while (1) {
sleep(1);
if (--timeout <= 0)
break;
if (kill(parent, 0)) {
/* process is gone */
return EXIT_SUCCESS;
}
}
kill(parent, signo);
return EXIT_SUCCESS;
}
/* Parent */
wait(&status); /* wait for child to die */
/* Did intermediate [v]fork or exec fail? */
if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
return EXIT_FAILURE;
/* Ok, exec a program as requested */
argv += optind;
#if !BB_MMU
argv[0] = sv1;
argv[1] = sv2;
#endif
BB_EXECVP_or_die(argv);
}
