1import array
2import unittest
3from test.test_support import run_unittest, import_module, get_attribute
4import os, struct
5fcntl = import_module('fcntl')
6termios = import_module('termios')
7get_attribute(termios, 'TIOCGPGRP') #Can't run tests without this feature
8
9try:
10    tty = open("/dev/tty", "r")
11except IOError:
12    raise unittest.SkipTest("Unable to open /dev/tty")
13else:
14    # Skip if another process is in foreground
15    r = fcntl.ioctl(tty, termios.TIOCGPGRP, "    ")
16    tty.close()
17    rpgrp = struct.unpack("i", r)[0]
18    if rpgrp not in (os.getpgrp(), os.getsid(0)):
19        raise unittest.SkipTest("Neither the process group nor the session "
20                                "are attached to /dev/tty")
21    del tty, r, rpgrp
22
23try:
24    import pty
25except ImportError:
26    pty = None
27
28class IoctlTests(unittest.TestCase):
29    def test_ioctl(self):
30        # If this process has been put into the background, TIOCGPGRP returns
31        # the session ID instead of the process group id.
32        ids = (os.getpgrp(), os.getsid(0))
33        tty = open("/dev/tty", "r")
34        r = fcntl.ioctl(tty, termios.TIOCGPGRP, "    ")
35        rpgrp = struct.unpack("i", r)[0]
36        self.assertIn(rpgrp, ids)
37
38    def _check_ioctl_mutate_len(self, nbytes=None):
39        buf = array.array('i')
40        intsize = buf.itemsize
41        ids = (os.getpgrp(), os.getsid(0))
42        # A fill value unlikely to be in `ids`
43        fill = -12345
44        if nbytes is not None:
45            # Extend the buffer so that it is exactly `nbytes` bytes long
46            buf.extend([fill] * (nbytes // intsize))
47            self.assertEqual(len(buf) * intsize, nbytes)   # sanity check
48        else:
49            buf.append(fill)
50        with open("/dev/tty", "r") as tty:
51            r = fcntl.ioctl(tty, termios.TIOCGPGRP, buf, 1)
52        rpgrp = buf[0]
53        self.assertEqual(r, 0)
54        self.assertIn(rpgrp, ids)
55
56    def test_ioctl_mutate(self):
57        self._check_ioctl_mutate_len()
58
59    def test_ioctl_mutate_1024(self):
60        # Issue #9758: a mutable buffer of exactly 1024 bytes wouldn't be
61        # copied back after the system call.
62        self._check_ioctl_mutate_len(1024)
63
64    def test_ioctl_mutate_2048(self):
65        # Test with a larger buffer, just for the record.
66        self._check_ioctl_mutate_len(2048)
67
68    def test_ioctl_signed_unsigned_code_param(self):
69        if not pty:
70            raise unittest.SkipTest('pty module required')
71        mfd, sfd = pty.openpty()
72        try:
73            if termios.TIOCSWINSZ < 0:
74                set_winsz_opcode_maybe_neg = termios.TIOCSWINSZ
75                set_winsz_opcode_pos = termios.TIOCSWINSZ & 0xffffffffL
76            else:
77                set_winsz_opcode_pos = termios.TIOCSWINSZ
78                set_winsz_opcode_maybe_neg, = struct.unpack("i",
79                        struct.pack("I", termios.TIOCSWINSZ))
80
81            our_winsz = struct.pack("HHHH",80,25,0,0)
82            # test both with a positive and potentially negative ioctl code
83            new_winsz = fcntl.ioctl(mfd, set_winsz_opcode_pos, our_winsz)
84            new_winsz = fcntl.ioctl(mfd, set_winsz_opcode_maybe_neg, our_winsz)
85        finally:
86            os.close(mfd)
87            os.close(sfd)
88
89def test_main():
90    run_unittest(IoctlTests)
91
92if __name__ == "__main__":
93    test_main()
94