#include <assert.h>
#include <pty.h>
#include <poll.h>
+#include <sys/stat.h>
#define LENGTH(x) (sizeof (x) / sizeof (*(x)))
static const char *progname;
-static volatile int signal_child_hit = 0;
+static volatile pid_t child;
-/* We use it to race-safely emulate ppoll(2) by poll(2). */
-static int pipefd[2];
-
-static void signal_child (int signo)
+static void signal_chld (int signo)
{
- int i;
+}
- signal_child_hit = 1;
+static volatile int signal_alrm_hit = 0;
- assert (pipefd[1] != -1);
- i = close (pipefd[1]);
- assert (i == 0);
- pipefd[1] = -1;
+static void signal_alrm (int signo)
+{
+ signal_alrm_hit = 1;
}
static char childptyname[LINE_MAX];
-static pid_t child;
-static int spawn (char **argv)
+static void print_child_error (const char *reason, char **argv)
+{
+ char **sp;
+
+ fprintf (stderr, "%s: %d %s:", progname, (int) child, reason);
+ for (sp = argv; *sp != NULL; sp++)
+ {
+ fputc (' ', stderr);
+ fputs (*sp, stderr);
+ }
+ fputc ('\n', stderr);
+}
+
+static int read_out (int amaster)
+{
+ char buf[LINE_MAX];
+ ssize_t buf_got;
+
+ buf_got = read (amaster, buf, sizeof buf);
+ if (buf_got == 0)
+ return 0;
+ /* Weird but at least after POLLHUP we get EIO instead of just EOF. */
+ if (buf_got == -1 && errno == EIO)
+ return 0;
+ if (buf_got == -1 && errno == EAGAIN)
+ return 0;
+ if (buf_got < 0)
+ {
+ perror ("read (amaster)");
+ exit (EXIT_FAILURE);
+ }
+ if (write (STDOUT_FILENO, buf, buf_got) != buf_got)
+ {
+ perror ("write(2)");
+ exit (EXIT_FAILURE);
+ }
+ return 1;
+}
+
+/* kill (child, 0) ==0 sometimes even when CHILD's state is already Z. */
+
+static int child_exited (void)
+{
+ char buf[200];
+ int fd, i, retval;
+ ssize_t got;
+ char *state;
+
+ snprintf (buf, sizeof (buf), "/proc/%ld/stat", (long) child);
+ fd = open (buf, O_RDONLY);
+ if (fd == -1)
+ {
+ perror ("open (/proc/CHILD/stat)");
+ exit (EXIT_FAILURE);
+ }
+ got = read (fd, buf, sizeof(buf));
+ if (got <= 0)
+ {
+ perror ("read (/proc/CHILD/stat)");
+ exit (EXIT_FAILURE);
+ }
+ if (close (fd) != 0)
+ {
+ perror ("close (/proc/CHILD/stat)");
+ exit (EXIT_FAILURE);
+ }
+ i = sscanf (buf, "%*d%*s%ms", &state);
+ if (i != 1)
+ {
+ perror ("sscanf (/proc/CHILD/stat)");
+ exit (EXIT_FAILURE);
+ }
+ retval = strcmp (state, "Z") == 0;
+ free (state);
+ return retval;
+}
+
+static int spawn (char **argv, int timeout)
{
pid_t child_got;
- int status, amaster, i;
+ int status, amaster, i, rc;
struct sigaction act;
+ sigset_t set;
struct termios termios;
+ unsigned alarm_orig;
- i = pipe (pipefd);
- assert (i == 0);
-
- /* We do not use signal(2) to be sure we have SA_RESTART set. */
+ /* We do not use signal(2) to be sure we do not have SA_RESTART. */
memset (&act, 0, sizeof (act));
- act.sa_handler = signal_child;
+ act.sa_handler = signal_chld;
i = sigemptyset (&act.sa_mask);
assert (i == 0);
- act.sa_flags = SA_RESTART;
+ act.sa_flags = 0; /* !SA_RESTART */
i = sigaction (SIGCHLD, &act, NULL);
assert (i == 0);
+ i = sigemptyset (&set);
+ assert (i == 0);
+ i = sigaddset (&set, SIGCHLD);
+ assert (i == 0);
+ i = sigprocmask (SIG_SETMASK, &set, NULL);
+ assert (i == 0);
+
/* With TERMP passed as NULL we get "\n" -> "\r\n". */
termios.c_iflag = IGNBRK | IGNPAR;
termios.c_oflag = 0;
perror ("forkpty(3)");
exit (EXIT_FAILURE);
case 0:
- i = close (pipefd[0]);
- assert (i == 0);
- i = close (pipefd[1]);
- assert (i == 0);
-
/* Do not replace STDIN as inferiors query its termios. */
#if 0
i = close (STDIN_FILENO);
assert (i == STDIN_FILENO);
#endif
+ i = sigemptyset (&set);
+ assert (i == 0);
+ i = sigprocmask (SIG_SETMASK, &set, NULL);
+ assert (i == 0);
+
/* Do not setpgrp(2) in the parent process as the process-group
is shared for the whole sh(1) pipeline we could be a part
of. The process-group is set according to PID of the first
perror ("getpgrp(2)");
exit (EXIT_FAILURE);
}
- execvp (argv[1], argv + 1);
+ execvp (argv[0], argv);
perror ("execvp(2)");
exit (EXIT_FAILURE);
default:
perror ("fcntl (amaster, F_SETFL, O_NONBLOCK)");
exit (EXIT_FAILURE);
}
- for (;;)
+
+ /* We do not use signal(2) to be sure we do not have SA_RESTART. */
+ act.sa_handler = signal_alrm;
+ i = sigaction (SIGALRM, &act, NULL);
+ assert (i == 0);
+
+ alarm_orig = alarm (timeout);
+ assert (alarm_orig == 0);
+
+ i = sigemptyset (&set);
+ assert (i == 0);
+
+ while (!signal_alrm_hit)
{
- struct pollfd pollfd[2];
- char buf[LINE_MAX];
- ssize_t buf_got;
+ struct pollfd pollfd;
- pollfd[0].fd = amaster;
- pollfd[0].events = POLLIN;
- pollfd[1].fd = pipefd[0];
- pollfd[1].events = POLLIN;
- i = poll (pollfd, LENGTH (pollfd), -1);
+ pollfd.fd = amaster;
+ pollfd.events = POLLIN;
+ i = ppoll (&pollfd, 1, NULL, &set);
if (i == -1 && errno == EINTR)
- {
- /* Weird but SA_RESTART sometimes does not work. */
+ {
+ if (child_exited ())
+ break;
+ /* Non-CHILD child may have exited. */
continue;
}
- assert (i >= 1);
+ assert (i == 1);
/* Data available? Process it first. */
- if (pollfd[0].revents & POLLIN)
+ if (pollfd.revents & POLLIN)
{
- buf_got = read (amaster, buf, sizeof buf);
- if (buf_got <= 0)
+ if (!read_out (amaster))
{
- perror ("read (amaster)");
- exit (EXIT_FAILURE);
- }
- if (write (STDOUT_FILENO, buf, buf_got) != buf_got)
- {
- perror ("write(2)");
+ fprintf (stderr, "%s: Unexpected EOF\n", progname);
exit (EXIT_FAILURE);
}
}
- if (pollfd[0].revents & POLLHUP)
+ if (pollfd.revents & POLLHUP)
break;
- if ((pollfd[0].revents &= ~POLLIN) != 0)
+ if ((pollfd.revents &= ~POLLIN) != 0)
{
fprintf (stderr, "%s: ppoll(2): revents 0x%x\n", progname,
- (unsigned) pollfd[0].revents);
+ (unsigned) pollfd.revents);
exit (EXIT_FAILURE);
}
/* Child exited? */
- if (pollfd[1].revents & POLLHUP)
+ if (child_exited ())
break;
- assert (pollfd[1].revents == 0);
}
+
+ if (signal_alrm_hit)
+ {
+ i = kill (child, SIGKILL);
+ assert (i == 0);
+ }
+ else
+ alarm (0);
+
/* WNOHANG still could fail. */
child_got = waitpid (child, &status, 0);
if (child != child_got)
fprintf (stderr, "waitpid (%d) = %d: %m\n", (int) child, (int) child_got);
exit (EXIT_FAILURE);
}
- if (!WIFEXITED (status))
+ if (signal_alrm_hit)
+ {
+ char *buf;
+
+ if (asprintf (&buf, "Timed out after %d seconds", timeout) != -1)
+ {
+ print_child_error (buf, argv);
+ free (buf);
+ }
+ rc = 128 + SIGALRM;
+ }
+ else if (WIFEXITED (status))
+ rc = WEXITSTATUS (status);
+ else if (WIFSIGNALED (status))
+ {
+ print_child_error (strsignal (WTERMSIG (status)), argv);
+ rc = 128 + WTERMSIG (status);
+ }
+ else if (WIFSTOPPED (status))
+ {
+ fprintf (stderr, "waitpid (%d): WIFSTOPPED - WSTOPSIG is %d\n",
+ (int) child, WSTOPSIG (status));
+ exit (EXIT_FAILURE);
+ }
+ else
{
fprintf (stderr, "waitpid (%d): !WIFEXITED (%d)\n", (int) child, status);
exit (EXIT_FAILURE);
}
- assert (signal_child_hit != 0);
- assert (pipefd[1] == -1);
- i = close (pipefd[0]);
+ /* Not used in fact. */
+ i = sigprocmask (SIG_SETMASK, &set, NULL);
assert (i == 0);
+ /* Do not unset O_NONBLOCK as a stale child (the whole purpose of this
+ program) having open its output pty would block us in read_out. */
+#if 0
+ i = fcntl (amaster, F_SETFL, O_RDONLY /* !O_NONBLOCK */);
+ if (i != 0)
+ {
+ perror ("fcntl (amaster, F_SETFL, O_RDONLY /* !O_NONBLOCK */)");
+ exit (EXIT_FAILURE);
+ }
+#endif
+
+ while (read_out (amaster));
+
/* Do not close the master FD as the child would have `/dev/pts/23 (deleted)'
entries which are not expected (and expecting ` (deleted)' would be
a race. */
}
#endif
- return WEXITSTATUS (status);
+ return rc;
}
/* Detected commandline may look weird due to a race:
pathname_len = snprintf (pathname, sizeof pathname, "%s/%s",
dirname, dirent->d_name);
- if (pathname_len <= 0 || pathname_len >= sizeof pathname)
+ if (pathname_len <= 0 || pathname_len >= (int) sizeof pathname)
{
fprintf (stderr, "entry file name too long: `%s' / `%s'\n",
dirname, dirent->d_name);
if (dirent->d_type == DT_DIR)
return 0;
buf_len = readlink (pathname, buf, sizeof buf - 1);
- if (buf_len <= 0 || buf_len >= sizeof buf - 1)
+ if (buf_len <= 0 || buf_len >= (ssize_t) sizeof buf - 1)
{
if (errno != ENOENT && errno != EACCES)
fprintf (stderr, "Error reading link \"%s\": %m\n", pathname);
int main (int argc, char **argv)
{
+ int timeout = 0;
int rc;
- if (argc < 2 || strcmp (argv[1], "-h") == 0
- || strcmp (argv[1], "--help") == 0)
+ progname = *argv++;
+ argc--;
+
+ if (argc < 1 || strcmp (*argv, "-h") == 0
+ || strcmp (*argv, "--help") == 0)
{
- fputs ("Syntax: orphanripper <execvp(3) commandline>\n", stdout);
+ puts ("Syntax: orphanripper [-t <seconds>] <execvp(3) commandline>");
exit (EXIT_FAILURE);
}
- progname = argv[0];
- rc = spawn (argv);
+ if ((*argv)[0] == '-' && (*argv)[1] == 't')
+ {
+ char *timeout_s = NULL;
+
+ if ((*argv)[2] == 0)
+ timeout_s = *++argv;
+ else if (isdigit ((*argv)[2]))
+ timeout_s = (*argv) + 2;
+ if (timeout_s != NULL)
+ {
+ long l;
+ char *endptr;
+
+ argv++;
+ l = strtol (timeout_s, &endptr, 0);
+ timeout = l;
+ if ((endptr != NULL && *endptr != 0) || timeout < 0 || timeout != l)
+ {
+ fprintf (stderr, "%s: Invalid timeout value: %s\n", progname,
+ timeout_s);
+ exit (EXIT_FAILURE);
+ }
+ }
+ }
+
+ rc = spawn (argv, timeout);
rip ();
return rc;
}
git://git.jankratochvil.net / nethome.git / blobdiff