/****** uti/pty/fork_pty() *****************************************************
* NAME
* fork_pty() -- Opens a pty, forks and redirects the std handles
*
* SYNOPSIS
* pid_t fork_pty(int *ptrfdm, int *fd_pipe_err, dstring *err_msg)
*
* FUNCTION
* Opens a pty, forks and redirects stdin, stdout and stderr of the child
* to the pty.
*
* INPUTS
* int *ptrfdm - Receives the file descriptor of the master side of
* the pty.
* int *fd_pipe_err - A int[2] array that receives the file descriptors
* of a pipe to separately redirect stderr.
* To achieve the same behaviour like rlogin/rsh, this
* is normally disabled, compile with
* -DUSE_PTY_AND_PIPE_ERR to enable this feature.
* dstring *err_msg - Receives an error string in case of error.
*
* RESULT
* pid_t - -1 in case of error,
* 0 in the child process,
* or the pid of the child process in the parent process.
*
* NOTES
* MT-NOTE: fork_pty() is not MT safe
*
* SEE ALSO
* pty/fork_no_pty
*******************************************************************************/
pid_t fork_pty(int *ptrfdm, int *fd_pipe_err, dstring *err_msg)
{
pid_t pid;
int fdm, fds;
char pts_name[20];
int old_euid;
/*
* We run this either as root with euid="sge admin user" or as an unprivileged
* user. If we are root with euid="sge admin user", we must change our
* euid back to root for this function.
*/
old_euid = geteuid();
if (getuid() == SGE_SUPERUSER_UID) {
seteuid(SGE_SUPERUSER_UID);
}
if ((fdm = ptym_open(pts_name)) < 0) {
sge_dstring_sprintf(err_msg, "can't open master pty \"%s\": %d, %s",
pts_name, errno, strerror(errno));
return -1;
}
#if defined(USE_PTY_AND_PIPE_ERR)
if (pipe(fd_pipe_err) == -1) {
sge_dstring_sprintf(err_msg, "can't create pipe for stderr: %d, %s",
errno, strerror(errno));
return -1;
}
#endif
if ((pid = fork()) < 0) {
return -1;
} else if (pid == 0) { /* child */
if ((g_newpgrp = setsid()) < 0) {
sge_dstring_sprintf(err_msg, "setsid() error: %d, %s",
errno, strerror(errno));
return -1;
}
/* Open pty slave */
if ((fds = ptys_open(fdm, pts_name)) < 0) {
seteuid(old_euid);
sge_dstring_sprintf(err_msg, "can't open slave pty: %d", fds);
return -1;
}
seteuid(old_euid);
close(fdm);
fdm = -1; /* all done with master in child */
#if defined(TIOCSCTTY) && !defined(CIBAUD)
/* 44BSD way to acquire controlling terminal */
/* !CIBAUD to avoid doing this under SunOS */
if (ioctl(fds, TIOCSCTTY, (char *) 0) < 0) {
sge_dstring_sprintf(err_msg, "TIOCSCTTY error: %d, %s",
errno, strerror(errno));
return -1;
}
#endif
/* slave becomes stdin/stdout/stderr of child */
if ((dup2(fds, STDIN_FILENO)) != STDIN_FILENO) {
sge_dstring_sprintf(err_msg, "dup2 to stdin error: %d, %s",
errno, strerror(errno));
return -1;
}
if ((dup2(fds, STDOUT_FILENO)) != STDOUT_FILENO) {
sge_dstring_sprintf(err_msg, "dup2 to stdout error: %d, %s",
errno, strerror(errno));
return -1;
}
#if defined(USE_PTY_AND_PIPE_ERR)
close(fd_pipe_err[0]);
fd_pipe_err[0] = -1;
if ((dup2(fd_pipe_err[1], STDERR_FILENO)) != STDERR_FILENO) {
sge_dstring_sprintf(err_msg, "dup2 to stderr error: %d, %s",
errno, strerror(errno));
return -1;
}
close(fd_pipe_err[1]);
fd_pipe_err[1] = -1;
#else
if ((dup2(fds, STDERR_FILENO)) != STDERR_FILENO) {
sge_dstring_sprintf(err_msg, "dup2 to stderr error: %d, %s",
errno, strerror(errno));
return -1;
}
#endif
if (fds > STDERR_FILENO) {
close(fds);
fds = -1;
}
return 0; /* child returns 0 just like fork() */
} else { /* parent */
*ptrfdm = fdm; /* return fd of master */
close(fd_pipe_err[1]);
fd_pipe_err[1] = -1;
seteuid(old_euid);
return pid; /* parent returns pid of child */
}
}
pid_t pty_fork(int *ptrfdm, char *slave_name, int slave_namesz, const struct termios *slave_termios, const struct winsize *slave_winsize)
{
int fdm, fds;
pid_t pid;
char pts_name[20];
if ((fdm = ptym_open(pts_name, sizeof(pts_name))) < 0)
err_sys("can't open master pty: %s, error %d", pts_name, fdm);
if (slave_name != NULL) {
/*
* Return name of slave. Null terminate to handle case
* where strlen(pts_name) > slave_namesz.
*/
strncpy(slave_name, pts_name, slave_namesz);
slave_name[slave_namesz - 1] = '\0';
}
if ((pid = fork()) < 0) {
return -1;
} else if (pid == 0) { /* child */
if (setsid() < 0)
err_sys("setsid error");
/*
* System V acquires controlling terminal on open().
*/
if ((fds = ptys_open(pts_name)) < 0)
err_sys("can't open slave pty");
close(fdm); /* all done with master in child */
#if defined(TIOCSCTTY)
/*
* TIOCSCTTY is the BSD way to acquire a controlling terminal.
*/
if (ioctl(fds, TIOCSCTTY, (char *)0) < 0)
err_sys("TIOCSCTTY error");
#endif
/*
* Set slave's termios and window size.
*/
if (slave_termios != NULL) {
if (tcsetattr(fds, TCSANOW, slave_termios) < 0)
err_sys("tcsetattr error on slave pty");
}
if (slave_winsize != NULL) {
if (ioctl(fds, TIOCSWINSZ, slave_winsize) < 0)
err_sys("TIOCSWINSZ error on slave pty");
}
/*
* Slave becomes stdin/stdout/stderr of child.
*/
if (dup2(fds, STDIN_FILENO) != STDIN_FILENO)
err_sys("dup2 error to stdin");
if (dup2(fds, STDOUT_FILENO) != STDOUT_FILENO)
err_sys("dup2 error to stdout");
if (dup2(fds, STDERR_FILENO) != STDERR_FILENO)
err_sys("dup2 error to stderr");
if (fds != STDIN_FILENO && fds != STDOUT_FILENO && fds != STDERR_FILENO)
close(fds);
return 0; /* child return 0 just like fork() */
} else { /* parent */
*ptrfdm = fdm; /* return fd of master */
return pid; /* parent returns pid of child */
}
}
pid_t
exec_pty(const char *path, char *const argv[], char *const envp[],
const char *dirpath, int channels[3], const char *pts_name, int fdm)
{
int pipe2[2];
pid_t childpid;
char *full_path;
/*
* We use pfind() to check that the program exists and is an executable.
* If not pass the error up. Also execve() wants a full path.
*/
full_path = pfind(path);
if (full_path == NULL) {
fprintf(stderr, "Unable to find full path for \"%s\"\n", (path) ? path : "");
return -1;
}
/*
* Make sure we can create our pipes before forking.
*/
if (channels != NULL) {
if (pipe(pipe2) < 0) {
fprintf(stderr, "%s(%d): returning due to error: %s\n", __FUNCTION__, __LINE__, strerror(errno));
free(full_path);
return -1;
}
}
childpid = fork();
if (childpid < 0) {
fprintf(stderr, "%s(%d): returning due to error: %s\n", __FUNCTION__, __LINE__, strerror(errno));
free(full_path);
return -1;
} else if (childpid == 0) { /* child */
chdir(dirpath);
if (channels != NULL) {
int fds;
fds = ptys_open(fdm, pts_name);
if (fds < 0) {
fprintf(stderr, "%s(%d): returning due to error: %s\n", __FUNCTION__, __LINE__, strerror(errno));
return -1;
}
/* Close the read end of pipe2 */
if (close(pipe2[0]) == -1)
perror("close(pipe2[0]))");
/* close the master, no need in the child */
close(fdm);
set_noecho(fds);
/* redirections */
dup2(fds, STDIN_FILENO); /* dup stdin */
dup2(fds, STDOUT_FILENO); /* dup stdout */
dup2(pipe2[1], STDERR_FILENO); /* dup stderr */
close(fds); /* done with fds. */
}
/* Close all the fd's in the child */
{
int fdlimit = sysconf(_SC_OPEN_MAX);
int fd = 3;
while (fd < fdlimit)
close(fd++);
}
if (envp[0] == NULL) {
execv(full_path, argv);
} else {
execve(full_path, argv, envp);
}
_exit(127);
} else if (childpid != 0) { /* parent */
set_noecho(fdm);
if (channels != NULL) {
/* close the write end of pipe1 */
if (close(pipe2[1]) == -1)
perror("close(pipe2[1])");
channels[0] = fdm; /* Input Stream. */
channels[1] = fdm; /* Output Stream. */
channels[2] = pipe2[0]; /* stderr Stream. */
/*channels[2] = fdm; Input Stream. */
}
free(full_path);
return childpid;
}
free(full_path);
return -1; /*NOT REACHED */
}
pid_t
pty_fork2(int *ptrfdm, char *slave_name)
{
int fdm, fds;
pid_t pid;
char pts_name[20];
if ( (fdm = ptym_open(pts_name)) < 0)
{
msg("can't open master pty");
return ERRO;
}
strcpy(slave_name, pts_name); /* return name of slave */
/*/printf("\npty_fork2: %d %s", fdm, pts_name); */
if ( (pid = fork()) < 0)
{
msg("Can not fork");
return ERRO;
}
else if (pid == 0) { /* child */
/*/ sleep(30); */
if (setsid() < 0)
{
msg("setsid error");
exit(1);
}
/* SVR4 acquires controlling terminal on open() */
if ( (fds = ptys_open(fdm, pts_name)) < 0)
{
msg("can't open slave pty");
exit(1);
}
close(fdm); /* all done with master in child */
#ifdef LINUX
/* 44BSD way to acquire controlling terminal */
if (ioctl(fds, TIOCSCTTY, (char *) 0) < 0)
{
msg("TIOCSCTTY error");
return ERRO;
}
#endif
if (tty_copy(fds) == ERRO)
exit(1);
/* slave becomes stdin/stdout/stderr of child */
if (dup2(fds, STDOUT_FILENO) != STDOUT_FILENO ||
dup2(fds, STDERR_FILENO) != STDERR_FILENO ||
dup2(fds, STDIN_FILENO) != STDIN_FILENO )
{
msg("dup2 error to slave");
exit(1);
}
if (fds > STDERR_FILENO)
close(fds);
return 0; /* child returns 0 just like fork() */
} else { /* parent */
*ptrfdm = fdm; /* return fd of master */
return(pid); /* parent returns pid of child */
}
}
