int
do_pty(void)
{
struct kevent ev[4];
struct termios tt;
int kq, massa, slave;
char buf[1024];
tcgetattr(STDIN_FILENO, &tt);
cfmakeraw(&tt);
tt.c_lflag &= ~ECHO;
if (openpty(&massa, &slave, NULL, &tt, NULL) < 0)
err(1, "openpty");
if (fcntl(massa, F_SETFL, O_NONBLOCK) < 0)
err(1, "massa: fcntl");
if (fcntl(slave, F_SETFL, O_NONBLOCK) < 0)
err(1, "massa: fcntl");
if ((kq = kqueue()) == -1)
err(1, "kqueue");
/* test the read from the slave works */
EV_SET(&ev[0], massa, EVFILT_READ, EV_ADD|EV_ENABLE, 0, 0, NULL);
EV_SET(&ev[1], massa, EVFILT_WRITE, EV_ADD|EV_ENABLE, 0, 0, NULL);
EV_SET(&ev[2], slave, EVFILT_READ, EV_ADD|EV_ENABLE, 0, 0, NULL);
EV_SET(&ev[3], slave, EVFILT_WRITE, EV_ADD|EV_ENABLE, 0, 0, NULL);
if (kevent(kq, ev, 4, NULL, 0, NULL) < 0)
err(1, "slave: kevent add");
memset(buf, 0, sizeof buf);
if (write(massa, " ", 1) != 1)
err(1, "massa: write");
if (pty_check(kq, ev, 4, -massa, slave, massa, slave))
return (1);
read(slave, buf, sizeof(buf));
if (pty_check(kq, ev, 4, -massa, -slave, massa, slave))
return (1);
while (write(massa, buf, sizeof(buf)) > 0)
continue;
if (pty_check(kq, ev, 4, -massa, slave, -massa, slave))
return (1);
read(slave, buf, 1);
if (pty_check(kq, ev, 4, -massa, slave, massa, slave))
return (1);
while (read(slave, buf, sizeof(buf)) > 0)
continue;
if (pty_check(kq, ev, 4, -massa, -slave, massa, slave))
return (1);
return (0);
}
static int
pty_alloc_master(struct lwp *l, int *fd, dev_t *dev, struct mount *mp)
{
int error;
struct file *fp;
struct vnode *vp;
int md;
if ((error = fd_allocfile(&fp, fd)) != 0) {
DPRINTF(("fd_allocfile %d\n", error));
return error;
}
retry:
/* Find and open a free master pty. */
*dev = pty_getfree();
md = minor(*dev);
if ((error = pty_check(md)) != 0) {
DPRINTF(("pty_check %d\n", error));
goto bad;
}
if (ptm == NULL) {
DPRINTF(("no ptm\n"));
error = EOPNOTSUPP;
goto bad;
}
/*
* XXX Since PTYFS has now multiple instance support, if we mounted
* more than one PTYFS we must check here the ptyfs_used_tbl, to find
* out if the ptyfsnode is under the appropriate mount and skip the
* node if not, because the pty could has been released, but
* ptyfs_reclaim didn't get a chance to release the corresponding
* node other mount point yet.
*
* It's important to have only one mount point's ptyfsnode for each
* appropriate device in ptyfs_used_tbl, else we will have a security
* problem, because every entry will have access to this device.
*
* Also we will not have not efficient vnode and memory usage.
* You can test this by changing a_recycle from true to false
* in ptyfs_inactive.
*/
if ((error = (*ptm->allocvp)(mp, l, &vp, *dev, 'p')) != 0) {
DPRINTF(("pty_allocvp %d\n", error));
goto bad;
}
if ((error = pty_vn_open(vp, l)) != 0) {
DPRINTF(("pty_vn_open %d\n", error));
/*
* Check if the master open failed because we lost
* the race to grab it.
*/
if (error != EIO)
goto bad;
error = !pty_isfree(md, 1);
DPRINTF(("pty_isfree %d\n", error));
if (error)
goto retry;
else
goto bad;
}
fp->f_flag = FREAD|FWRITE;
fp->f_type = DTYPE_VNODE;
fp->f_ops = &vnops;
fp->f_data = vp;
VOP_UNLOCK(vp);
fd_affix(curproc, fp, *fd);
return 0;
bad:
fd_abort(curproc, fp, *fd);
return error;
}