/*
* eval - Evaluate the command line that the user has just typed in
*
* If the user has requested a built-in command (quit, jobs, bg or fg)
* then execute it immediately. Otherwise, fork a child process and
* run the job in the context of the child. If the job is running in
* the foreground, wait for it to terminate and then return. Note:
* each child process must have a unique process group ID so that our
* background children don't receive SIGINT (SIGTSTP) from the kernel
* when we type ctrl-c (ctrl-z) at the keyboard.
*/
void eval(char *cmdline)
{
char *argv[MAXARGS];
/* int ground = parseline(cmdline, (char **)&argv); */
char buf[MAXLINE]; // Holds modified command line
strcpy(buf, cmdline);
int ground = parseline(buf, argv);
if (argv[0] == NULL) return;
if (!builtin_cmd((char **)&argv)) {
sigset_t mask;
sigemptyset(&mask);
sigaddset(&mask, SIGCHLD);
sigprocmask(SIG_BLOCK, &mask, NULL);
pid_t pid = __fork();
if (pid != 0) {
addjob(jobs, pid, ground ? BG : FG, cmdline);
sigprocmask(SIG_UNBLOCK, &mask, NULL);
if (!ground) waitfg(pid);
else printf("[%d] (%d) %s", pid2jid(pid), pid, cmdline);
} else {
__setpgid(0, 0);
sigprocmask(SIG_UNBLOCK, &mask, NULL);
if (execve(argv[0], argv, environ) < 0) {
printf("%s: Command not found\n", argv[0]);
exit(0);
}
}
}
return;
}
/*
* fork stub
*/
pid_t
fork(void)
{
int ret;
_libSystem_atfork_prepare();
// Reader beware: this __fork() call is yet another wrapper around the actual syscall
// and lives inside libsyscall. The fork syscall needs some cuddling by asm before it's
// allowed to see the big wide C world.
ret = __fork();
if (-1 == ret)
{
// __fork already set errno for us
_libSystem_atfork_parent();
return ret;
}
if (0 == ret)
{
// We're the child in this part.
_libSystem_atfork_child();
return 0;
}
_libSystem_atfork_parent();
return ret;
}
extern "C" NS_EXPORT pid_t
WRAP(fork)(void)
{
pid_t pid;
for (std::vector<AtForkFuncs>::reverse_iterator it = atfork.rbegin();
it < atfork.rend(); ++it)
if (it->prepare)
it->prepare();
switch ((pid = __fork())) {
case 0:
cpuacct_add(getuid());
for (std::vector<AtForkFuncs>::iterator it = atfork.begin();
it < atfork.end(); ++it)
if (it->child)
it->child();
break;
default:
for (std::vector<AtForkFuncs>::iterator it = atfork.begin();
it < atfork.end(); ++it)
if (it->parent)
it->parent();
}
return pid;
}
int fork(void)
{
int ret;
/* Posix mandates that the timers of a fork child process be
* disarmed, but not destroyed. To avoid a race condition, we're
* going to stop all timers now, and only re-start them in case
* of error, or in the parent process
*/
__timer_table_start_stop(1);
__bionic_atfork_run_prepare();
ret = __fork();
if (ret != 0) { /* not a child process */
__timer_table_start_stop(0);
__bionic_atfork_run_parent();
} else {
/*
* Newly created process must update cpu accounting.
* Call cpuacct_add passing in our uid, which will take
* the current task id and add it to the uid group passed
* as a parameter.
*/
cpuacct_add(getuid());
__bionic_atfork_run_child();
}
return ret;
}
/*
* returns pid, or -1 for failure
*/
int
_openchild (const char *command, FILE ** fto, FILE ** ffrom)
{
int i;
int pid;
int pdto[2];
int pdfrom[2];
if (__pipe (pdto) < 0)
goto error1;
if (__pipe (pdfrom) < 0)
goto error2;
switch (pid = __fork ())
{
case -1:
goto error3;
case 0:
/*
* child: read from pdto[0], write into pdfrom[1]
*/
__close (0);
__dup (pdto[0]);
__close (1);
__dup (pdfrom[1]);
fflush (stderr);
for (i = _rpc_dtablesize () - 1; i >= 3; i--)
__close (i);
fflush (stderr);
execlp (command, command, NULL);
perror ("exec");
_exit (~0);
default:
/*
* parent: write into pdto[1], read from pdfrom[0]
*/
*fto = __fdopen (pdto[1], "w");
__close (pdto[0]);
*ffrom = __fdopen (pdfrom[0], "r");
__close (pdfrom[1]);
break;
}
return pid;
/*
* error cleanup and return
*/
error3:
__close (pdfrom[0]);
__close (pdfrom[1]);
error2:
__close (pdto[0]);
__close (pdto[1]);
error1:
return -1;
}
int fork(void)
{
int pid;
struct handler_list * prepare, * child, * parent;
pthread_mutex_lock(&pthread_atfork_lock);
prepare = pthread_atfork_prepare;
child = pthread_atfork_child;
parent = pthread_atfork_parent;
pthread_mutex_unlock(&pthread_atfork_lock);
pthread_call_handlers(prepare);
pid = __fork();
if (pid == 0) {
__pthread_reset_main_thread();
__fresetlockfiles();
pthread_call_handlers(child);
} else {
pthread_call_handlers(parent);
}
return pid;
}
int
grantpt (int fd)
{
#if defined __OpenBSD__
/* On OpenBSD, master and slave of a pseudo-terminal are allocated together,
through an ioctl on /dev/ptm. There is no need for grantpt(). */
return 0;
#else
/* This function is most often called from a process without 'root'
credentials. Use the helper program. */
int retval = -1;
pid_t pid = __fork ();
if (pid == -1)
goto cleanup;
else if (pid == 0)
{
/* This is executed in the child process. */
# if HAVE_SETRLIMIT && defined RLIMIT_CORE
/* Disable core dumps. */
struct rlimit rl = { 0, 0 };
__setrlimit (RLIMIT_CORE, &rl);
# endif
/* We pass the master pseudo terminal as file descriptor PTY_FILENO. */
if (fd != PTY_FILENO)
if (__dup2 (fd, PTY_FILENO) < 0)
_exit (FAIL_EBADF);
# ifdef CLOSE_ALL_FDS
CLOSE_ALL_FDS ();
# endif
execle (_PATH_PT_CHOWN, strrchr (_PATH_PT_CHOWN, '/') + 1, NULL, NULL);
_exit (FAIL_EXEC);
}
else
{
int w;
if (__waitpid (pid, &w, 0) == -1)
goto cleanup;
if (!WIFEXITED (w))
__set_errno (ENOEXEC);
else
switch (WEXITSTATUS (w))
{
case 0:
retval = 0;
break;
case FAIL_EBADF:
__set_errno (EBADF);
break;
case FAIL_EINVAL:
__set_errno (EINVAL);
break;
case FAIL_EACCES:
__set_errno (EACCES);
break;
case FAIL_EXEC:
__set_errno (ENOEXEC);
break;
case FAIL_ENOMEM:
__set_errno (ENOMEM);
break;
default:
assert(! "getpt: internal error: invalid exit code from pt_chown");
}
}
cleanup:
return retval;
#endif
}
/* Execute LINE as a shell command, returning its status. */
static int
do_system (const char *line)
{
int status, save;
pid_t pid;
struct sigaction sa;
#ifndef _LIBC_REENTRANT
struct sigaction intr, quit;
#endif
sigset_t omask;
sa.sa_handler = SIG_IGN;
sa.sa_flags = 0;
__sigemptyset (&sa.sa_mask);
DO_LOCK ();
if (ADD_REF () == 0)
{
if (__sigaction (SIGINT, &sa, &intr) < 0)
{
(void) SUB_REF ();
goto out;
}
if (__sigaction (SIGQUIT, &sa, &quit) < 0)
{
save = errno;
(void) SUB_REF ();
goto out_restore_sigint;
}
}
DO_UNLOCK ();
/* We reuse the bitmap in the 'sa' structure. */
__sigaddset (&sa.sa_mask, SIGCHLD);
save = errno;
if (__sigprocmask (SIG_BLOCK, &sa.sa_mask, &omask) < 0)
{
#ifndef _LIBC
if (errno == ENOSYS)
__set_errno (save);
else
#endif
{
DO_LOCK ();
if (SUB_REF () == 0)
{
save = errno;
(void) __sigaction (SIGQUIT, &quit, (struct sigaction *) NULL);
out_restore_sigint:
(void) __sigaction (SIGINT, &intr, (struct sigaction *) NULL);
__set_errno (save);
}
out:
DO_UNLOCK ();
return -1;
}
}
#ifdef CLEANUP_HANDLER
CLEANUP_HANDLER;
#endif
#ifdef FORK
pid = FORK ();
#else
pid = __fork ();
#endif
if (pid == (pid_t) 0)
{
/* Child side. */
const char *new_argv[4];
new_argv[0] = SHELL_NAME;
new_argv[1] = "-c";
new_argv[2] = line;
new_argv[3] = NULL;
/* Restore the signals. */
(void) __sigaction (SIGINT, &intr, (struct sigaction *) NULL);
(void) __sigaction (SIGQUIT, &quit, (struct sigaction *) NULL);
(void) __sigprocmask (SIG_SETMASK, &omask, (sigset_t *) NULL);
INIT_LOCK ();
/* Exec the shell. */
(void) __execve (SHELL_PATH, (char *const *) new_argv, __environ);
_exit (127);
}
else if (pid < (pid_t) 0)
/* The fork failed. */
status = -1;
else
/* Parent side. */
{
/* Note the system() is a cancellation point. But since we call
waitpid() which itself is a cancellation point we do not
have to do anything here. */
if (TEMP_FAILURE_RETRY (__waitpid (pid, &status, 0)) != pid)
status = -1;
}
#ifdef CLEANUP_HANDLER
CLEANUP_RESET;
#endif
save = errno;
DO_LOCK ();
if ((SUB_REF () == 0
&& (__sigaction (SIGINT, &intr, (struct sigaction *) NULL)
| __sigaction (SIGQUIT, &quit, (struct sigaction *) NULL)) != 0)
|| __sigprocmask (SIG_SETMASK, &omask, (sigset_t *) NULL) != 0)
{
#ifndef _LIBC
/* glibc cannot be used on systems without waitpid. */
if (errno == ENOSYS)
__set_errno (save);
else
#endif
status = -1;
}
DO_UNLOCK ();
return status;
}
/* Spawn a new process executing PATH with the attributes describes in *ATTRP.
Before running the process perform the actions described in FILE-ACTIONS. */
int
__spawni (pid_t *pid, const char *file,
const posix_spawn_file_actions_t *file_actions,
const posix_spawnattr_t *attrp, char *const argv[],
char *const envp[], int xflags)
{
pid_t new_pid;
char *path, *p, *name;
size_t len;
size_t pathlen;
/* Do this once. */
short int flags = attrp == NULL ? 0 : attrp->__flags;
/* Generate the new process. */
if ((flags & POSIX_SPAWN_USEVFORK) != 0
/* If no major work is done, allow using vfork. Note that we
might perform the path searching. But this would be done by
a call to execvp(), too, and such a call must be OK according
to POSIX. */
|| ((flags & (POSIX_SPAWN_SETSIGMASK | POSIX_SPAWN_SETSIGDEF
| POSIX_SPAWN_SETSCHEDPARAM | POSIX_SPAWN_SETSCHEDULER
| POSIX_SPAWN_SETPGROUP | POSIX_SPAWN_RESETIDS)) == 0
&& file_actions == NULL))
new_pid = __vfork ();
else
new_pid = __fork ();
if (new_pid != 0)
{
if (new_pid < 0)
return errno;
/* The call was successful. Store the PID if necessary. */
if (pid != NULL)
*pid = new_pid;
return 0;
}
/* Set signal mask. */
if ((flags & POSIX_SPAWN_SETSIGMASK) != 0
&& __sigprocmask (SIG_SETMASK, &attrp->__ss, NULL) != 0)
_exit (SPAWN_ERROR);
/* Set signal default action. */
if ((flags & POSIX_SPAWN_SETSIGDEF) != 0)
{
/* We have to iterate over all signals. This could possibly be
done better but it requires system specific solutions since
the sigset_t data type can be very different on different
architectures. */
int sig;
struct sigaction sa;
memset (&sa, '\0', sizeof (sa));
sa.sa_handler = SIG_DFL;
for (sig = 1; sig <= _NSIG; ++sig)
if (__sigismember (&attrp->__sd, sig) != 0
&& __sigaction (sig, &sa, NULL) != 0)
_exit (SPAWN_ERROR);
}
#ifdef _POSIX_PRIORITY_SCHEDULING
/* Set the scheduling algorithm and parameters. */
if ((flags & (POSIX_SPAWN_SETSCHEDPARAM | POSIX_SPAWN_SETSCHEDULER))
== POSIX_SPAWN_SETSCHEDPARAM)
{
if (__sched_setparam (0, &attrp->__sp) == -1)
_exit (SPAWN_ERROR);
}
else if ((flags & POSIX_SPAWN_SETSCHEDULER) != 0)
{
if (__sched_setscheduler (0, attrp->__policy, &attrp->__sp) == -1)
_exit (SPAWN_ERROR);
}
#endif
/* Set the process group ID. */
if ((flags & POSIX_SPAWN_SETPGROUP) != 0
&& __setpgid (0, attrp->__pgrp) != 0)
_exit (SPAWN_ERROR);
/* Set the effective user and group IDs. */
if ((flags & POSIX_SPAWN_RESETIDS) != 0
&& (local_seteuid (__getuid ()) != 0
|| local_setegid (__getgid ()) != 0))
_exit (SPAWN_ERROR);
/* Execute the file actions. */
if (file_actions != NULL)
{
int cnt;
struct rlimit64 fdlimit;
bool have_fdlimit = false;
for (cnt = 0; cnt < file_actions->__used; ++cnt)
{
struct __spawn_action *action = &file_actions->__actions[cnt];
switch (action->tag)
{
case spawn_do_close:
if (close_not_cancel (action->action.close_action.fd) != 0)
{
if (! have_fdlimit)
{
getrlimit64 (RLIMIT_NOFILE, &fdlimit);
have_fdlimit = true;
}
/* Only signal errors for file descriptors out of range. */
if (action->action.close_action.fd < 0
|| action->action.close_action.fd >= fdlimit.rlim_cur)
/* Signal the error. */
_exit (SPAWN_ERROR);
}
break;
case spawn_do_open:
{
int new_fd = open_not_cancel (action->action.open_action.path,
action->action.open_action.oflag
| O_LARGEFILE,
action->action.open_action.mode);
if (new_fd == -1)
/* The `open' call failed. */
_exit (SPAWN_ERROR);
/* Make sure the desired file descriptor is used. */
if (new_fd != action->action.open_action.fd)
{
if (__dup2 (new_fd, action->action.open_action.fd)
!= action->action.open_action.fd)
/* The `dup2' call failed. */
_exit (SPAWN_ERROR);
if (close_not_cancel (new_fd) != 0)
/* The `close' call failed. */
_exit (SPAWN_ERROR);
}
}
break;
case spawn_do_dup2:
if (__dup2 (action->action.dup2_action.fd,
action->action.dup2_action.newfd)
!= action->action.dup2_action.newfd)
/* The `dup2' call failed. */
_exit (SPAWN_ERROR);
break;
}
}
}
if ((xflags & SPAWN_XFLAGS_USE_PATH) == 0 || strchr (file, '/') != NULL)
{
/* The FILE parameter is actually a path. */
__execve (file, argv, envp);
maybe_script_execute (file, argv, envp, xflags);
/* Oh, oh. `execve' returns. This is bad. */
_exit (SPAWN_ERROR);
}
/* We have to search for FILE on the path. */
path = getenv ("PATH");
if (path == NULL)
{
/* There is no `PATH' in the environment.
The default search path is the current directory
followed by the path `confstr' returns for `_CS_PATH'. */
len = confstr (_CS_PATH, (char *) NULL, 0);
path = (char *) __alloca (1 + len);
path[0] = ':';
(void) confstr (_CS_PATH, path + 1, len);
}
len = strlen (file) + 1;
pathlen = strlen (path);
name = __alloca (pathlen + len + 1);
/* Copy the file name at the top. */
name = (char *) memcpy (name + pathlen + 1, file, len);
/* And add the slash. */
*--name = '/';
p = path;
do
{
char *startp;
path = p;
p = __strchrnul (path, ':');
if (p == path)
/* Two adjacent colons, or a colon at the beginning or the end
of `PATH' means to search the current directory. */
startp = name + 1;
else
startp = (char *) memcpy (name - (p - path), path, p - path);
/* Try to execute this name. If it works, execv will not return. */
__execve (startp, argv, envp);
maybe_script_execute (startp, argv, envp, xflags);
switch (errno)
{
case EACCES:
case ENOENT:
case ESTALE:
case ENOTDIR:
/* Those errors indicate the file is missing or not executable
by us, in which case we want to just try the next path
directory. */
break;
default:
/* Some other error means we found an executable file, but
something went wrong executing it; return the error to our
caller. */
_exit (SPAWN_ERROR);
}
}
while (*p++ != '\0');
/* Return with an error. */
_exit (SPAWN_ERROR);
}
/* Change the ownership and access permission of the slave pseudo
terminal associated with the master pseudo terminal specified
by FD. */
int
grantpt (int fd)
{
int retval = -1;
#ifdef PATH_MAX
char _buf[PATH_MAX];
#else
char _buf[512];
#endif
char *buf = _buf;
struct stat64 st;
if (__glibc_unlikely (pts_name (fd, &buf, sizeof (_buf), &st)))
{
int save_errno = errno;
/* Check, if the file descriptor is valid. pts_name returns the
wrong errno number, so we cannot use that. */
if (__libc_fcntl (fd, F_GETFD) == -1 && errno == EBADF)
return -1;
/* If the filedescriptor is no TTY, grantpt has to set errno
to EINVAL. */
if (save_errno == ENOTTY)
__set_errno (EINVAL);
else
__set_errno (save_errno);
return -1;
}
/* Make sure that we own the device. */
uid_t uid = __getuid ();
if (st.st_uid != uid)
{
if (__chown (buf, uid, st.st_gid) < 0)
goto helper;
}
static int tty_gid = -1;
if (__glibc_unlikely (tty_gid == -1))
{
char *grtmpbuf;
struct group grbuf;
size_t grbuflen = __sysconf (_SC_GETGR_R_SIZE_MAX);
struct group *p;
/* Get the group ID of the special `tty' group. */
if (grbuflen == (size_t) -1L)
/* `sysconf' does not support _SC_GETGR_R_SIZE_MAX.
Try a moderate value. */
grbuflen = 1024;
grtmpbuf = (char *) __alloca (grbuflen);
__getgrnam_r (TTY_GROUP, &grbuf, grtmpbuf, grbuflen, &p);
if (p != NULL)
tty_gid = p->gr_gid;
}
gid_t gid = tty_gid == -1 ? __getgid () : tty_gid;
/* Make sure the group of the device is that special group. */
if (st.st_gid != gid)
{
if (__chown (buf, uid, gid) < 0)
goto helper;
}
/* Make sure the permission mode is set to readable and writable by
the owner, and writable by the group. */
if ((st.st_mode & ACCESSPERMS) != (S_IRUSR|S_IWUSR|S_IWGRP))
{
if (__chmod (buf, S_IRUSR|S_IWUSR|S_IWGRP) < 0)
goto helper;
}
retval = 0;
goto cleanup;
/* We have to use the helper program if it is available. */
helper:;
#ifdef HAVE_PT_CHOWN
pid_t pid = __fork ();
if (pid == -1)
goto cleanup;
else if (pid == 0)
{
/* Disable core dumps. */
struct rlimit rl = { 0, 0 };
__setrlimit (RLIMIT_CORE, &rl);
/* We pass the master pseudo terminal as file descriptor PTY_FILENO. */
if (fd != PTY_FILENO)
if (__dup2 (fd, PTY_FILENO) < 0)
_exit (FAIL_EBADF);
# ifdef CLOSE_ALL_FDS
CLOSE_ALL_FDS ();
# endif
execle (_PATH_PT_CHOWN, basename (_PATH_PT_CHOWN), NULL, NULL);
_exit (FAIL_EXEC);
}
else
{
int w;
if (__waitpid (pid, &w, 0) == -1)
goto cleanup;
if (!WIFEXITED (w))
__set_errno (ENOEXEC);
else
switch (WEXITSTATUS (w))
{
case 0:
retval = 0;
break;
case FAIL_EBADF:
__set_errno (EBADF);
break;
case FAIL_EINVAL:
__set_errno (EINVAL);
break;
case FAIL_EACCES:
__set_errno (EACCES);
break;
case FAIL_EXEC:
__set_errno (ENOEXEC);
break;
case FAIL_ENOMEM:
__set_errno (ENOMEM);
break;
default:
assert(! "getpt: internal error: invalid exit code from pt_chown");
}
}
#endif
cleanup:
if (buf != _buf)
free (buf);
return retval;
}
pid_t __vfork(void)
{
return __fork();
}
