libuv/test/test-tty.c
Ben Noordhuis 2e2114ed89
unix: fix partial read handling after POLLHUP (#4997)
It was reported that PTYs on Linux sometimes report POLLHUP, return a
partial read, but still return more data on the next read.

Libuv contains an optimization where it assumes a partial read after
POLLHUP means the next read can be skipped because it's going to fail
with EOF anyway. That assumption was thought to be always true but,
alas, it isn't.

The fact the optimization has been present for 13 years and this is the
first bug report about it, indicates how rare this particular condition
is, but of course we can't skim on correctness.

The reworked optimization only uses POLLHUP as an input signal when
POLLIN is not also set. That means we no longer have to track partial
reads because we're going to try and read anyway as long as POLLIN is
set. It seems to cause no measurable regressions on the test suite or
the (lightly tested) benchmarks.

Fixes: https://github.com/libuv/libuv/issues/4992
2026-01-18 12:21:53 +01:00

536 lines
15 KiB
C

/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include "uv.h"
#include "task.h"
#ifdef _WIN32
# include <io.h>
# include <windows.h>
#else /* Unix */
# include <fcntl.h>
# include <unistd.h>
# if defined(__linux__) && !defined(__ANDROID__)
# include <pty.h>
# elif defined(__OpenBSD__) || defined(__NetBSD__) || defined(__APPLE__)
# include <util.h>
# elif defined(__FreeBSD__) || defined(__DragonFly__)
# include <libutil.h>
# endif
#endif
#include <string.h>
#include <errno.h>
TEST_IMPL(tty) {
int r, width, height;
int ttyin_fd, ttyout_fd;
uv_tty_t tty_in, tty_out;
uv_loop_t* loop = uv_default_loop();
/* Make sure we have an FD that refers to a tty */
#ifdef _WIN32
HANDLE handle;
handle = CreateFileA("conin$",
GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
NULL);
ASSERT_PTR_NE(handle, INVALID_HANDLE_VALUE);
ttyin_fd = _open_osfhandle((intptr_t) handle, 0);
handle = CreateFileA("conout$",
GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
NULL);
ASSERT_PTR_NE(handle, INVALID_HANDLE_VALUE);
ttyout_fd = _open_osfhandle((intptr_t) handle, 0);
#else /* unix */
ttyin_fd = open("/dev/tty", O_RDONLY, 0);
if (ttyin_fd < 0) {
fprintf(stderr, "Cannot open /dev/tty as read-only: %s\n", strerror(errno));
fflush(stderr);
return TEST_SKIP;
}
ttyout_fd = open("/dev/tty", O_WRONLY, 0);
if (ttyout_fd < 0) {
fprintf(stderr, "Cannot open /dev/tty as write-only: %s\n", strerror(errno));
fflush(stderr);
return TEST_SKIP;
}
#endif
ASSERT_GE(ttyin_fd, 0);
ASSERT_GE(ttyout_fd, 0);
ASSERT_EQ(UV_UNKNOWN_HANDLE, uv_guess_handle(-1));
ASSERT_EQ(UV_TTY, uv_guess_handle(ttyin_fd));
ASSERT_EQ(UV_TTY, uv_guess_handle(ttyout_fd));
r = uv_tty_init(loop, &tty_in, ttyin_fd, 1); /* Readable. */
ASSERT_OK(r);
ASSERT(uv_is_readable((uv_stream_t*) &tty_in));
ASSERT(!uv_is_writable((uv_stream_t*) &tty_in));
r = uv_tty_init(loop, &tty_out, ttyout_fd, 0); /* Writable. */
ASSERT_OK(r);
ASSERT(!uv_is_readable((uv_stream_t*) &tty_out));
ASSERT(uv_is_writable((uv_stream_t*) &tty_out));
r = uv_tty_get_winsize(&tty_out, &width, &height);
ASSERT_OK(r);
printf("width=%d height=%d\n", width, height);
if (width == 0 && height == 0) {
/* Some environments such as containers or Jenkins behave like this
* sometimes */
MAKE_VALGRIND_HAPPY(loop);
return TEST_SKIP;
}
ASSERT_GT(width, 0);
ASSERT_GT(height, 0);
/* Turn on raw mode. */
r = uv_tty_set_mode(&tty_in, UV_TTY_MODE_RAW);
ASSERT_OK(r);
/* Turn off raw mode. */
r = uv_tty_set_mode(&tty_in, UV_TTY_MODE_NORMAL);
ASSERT_OK(r);
/* Calling uv_tty_reset_mode() repeatedly should not clobber errno. */
errno = 0;
ASSERT_OK(uv_tty_reset_mode());
ASSERT_OK(uv_tty_reset_mode());
ASSERT_OK(uv_tty_reset_mode());
ASSERT_OK(errno);
/* TODO check the actual mode! */
uv_close((uv_handle_t*) &tty_in, NULL);
uv_close((uv_handle_t*) &tty_out, NULL);
uv_run(loop, UV_RUN_DEFAULT);
MAKE_VALGRIND_HAPPY(uv_default_loop());
return 0;
}
#ifdef _WIN32
static void tty_raw_alloc(uv_handle_t* handle, size_t size, uv_buf_t* buf) {
buf->base = malloc(size);
buf->len = size;
}
static void tty_raw_read(uv_stream_t* tty_in, ssize_t nread, const uv_buf_t* buf) {
if (nread > 0) {
ASSERT_EQ(1, nread );
ASSERT_EQ(buf->base[0], ' ');
uv_close((uv_handle_t*) tty_in, NULL);
} else {
ASSERT_OK(nread);
}
}
TEST_IMPL(tty_raw) {
int r;
int ttyin_fd;
uv_tty_t tty_in;
uv_loop_t* loop = uv_default_loop();
HANDLE handle;
INPUT_RECORD record;
DWORD written;
/* Make sure we have an FD that refers to a tty */
handle = CreateFileA("conin$",
GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
NULL);
ASSERT_PTR_NE(handle, INVALID_HANDLE_VALUE);
ttyin_fd = _open_osfhandle((intptr_t) handle, 0);
ASSERT_GE(ttyin_fd, 0);
ASSERT_EQ(UV_TTY, uv_guess_handle(ttyin_fd));
r = uv_tty_init(loop, &tty_in, ttyin_fd, 1); /* Readable. */
ASSERT_OK(r);
ASSERT(uv_is_readable((uv_stream_t*) &tty_in));
ASSERT(!uv_is_writable((uv_stream_t*) &tty_in));
r = uv_read_start((uv_stream_t*)&tty_in, tty_raw_alloc, tty_raw_read);
ASSERT_OK(r);
/* Give uv_tty_line_read_thread time to block on ReadConsoleW */
Sleep(100);
/* Turn on raw mode. */
r = uv_tty_set_mode(&tty_in, UV_TTY_MODE_RAW);
ASSERT_OK(r);
/* Write ' ' that should be read in raw mode */
record.EventType = KEY_EVENT;
record.Event.KeyEvent.bKeyDown = TRUE;
record.Event.KeyEvent.wRepeatCount = 1;
record.Event.KeyEvent.wVirtualKeyCode = VK_SPACE;
record.Event.KeyEvent.wVirtualScanCode = MapVirtualKeyW(VK_SPACE, MAPVK_VK_TO_VSC);
record.Event.KeyEvent.uChar.UnicodeChar = L' ';
record.Event.KeyEvent.dwControlKeyState = 0;
WriteConsoleInputW(handle, &record, 1, &written);
uv_run(loop, UV_RUN_DEFAULT);
MAKE_VALGRIND_HAPPY(loop);
return 0;
}
TEST_IMPL(tty_empty_write) {
int r;
int ttyout_fd;
uv_tty_t tty_out;
char dummy[1];
uv_buf_t bufs[1];
uv_loop_t* loop;
/* Make sure we have an FD that refers to a tty */
HANDLE handle;
loop = uv_default_loop();
handle = CreateFileA("conout$",
GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
NULL);
ASSERT_PTR_NE(handle, INVALID_HANDLE_VALUE);
ttyout_fd = _open_osfhandle((intptr_t) handle, 0);
ASSERT_GE(ttyout_fd, 0);
ASSERT_EQ(UV_TTY, uv_guess_handle(ttyout_fd));
r = uv_tty_init(loop, &tty_out, ttyout_fd, 0); /* Writable. */
ASSERT_OK(r);
ASSERT(!uv_is_readable((uv_stream_t*) &tty_out));
ASSERT(uv_is_writable((uv_stream_t*) &tty_out));
bufs[0].len = 0;
bufs[0].base = &dummy[0];
r = uv_try_write((uv_stream_t*) &tty_out, bufs, 1);
ASSERT_OK(r);
uv_close((uv_handle_t*) &tty_out, NULL);
uv_run(loop, UV_RUN_DEFAULT);
MAKE_VALGRIND_HAPPY(loop);
return 0;
}
TEST_IMPL(tty_large_write) {
int r;
int ttyout_fd;
uv_tty_t tty_out;
char dummy[10000];
uv_buf_t bufs[1];
uv_loop_t* loop;
/* Make sure we have an FD that refers to a tty */
HANDLE handle;
loop = uv_default_loop();
handle = CreateFileA("conout$",
GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
NULL);
ASSERT_PTR_NE(handle, INVALID_HANDLE_VALUE);
ttyout_fd = _open_osfhandle((intptr_t) handle, 0);
ASSERT_GE(ttyout_fd, 0);
ASSERT_EQ(UV_TTY, uv_guess_handle(ttyout_fd));
r = uv_tty_init(loop, &tty_out, ttyout_fd, 0); /* Writable. */
ASSERT_OK(r);
memset(dummy, '.', sizeof(dummy) - 1);
dummy[sizeof(dummy) - 1] = '\n';
bufs[0] = uv_buf_init(dummy, sizeof(dummy));
r = uv_try_write((uv_stream_t*) &tty_out, bufs, 1);
ASSERT_EQ(10000, r);
uv_close((uv_handle_t*) &tty_out, NULL);
uv_run(loop, UV_RUN_DEFAULT);
MAKE_VALGRIND_HAPPY(loop);
return 0;
}
TEST_IMPL(tty_raw_cancel) {
int r;
int ttyin_fd;
uv_tty_t tty_in;
HANDLE handle;
/* Make sure we have an FD that refers to a tty */
handle = CreateFileA("conin$",
GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
NULL);
ASSERT_PTR_NE(handle, INVALID_HANDLE_VALUE);
ttyin_fd = _open_osfhandle((intptr_t) handle, 0);
ASSERT_GE(ttyin_fd, 0);
ASSERT_EQ(UV_TTY, uv_guess_handle(ttyin_fd));
r = uv_tty_init(uv_default_loop(), &tty_in, ttyin_fd, 1); /* Readable. */
ASSERT_OK(r);
r = uv_tty_set_mode(&tty_in, UV_TTY_MODE_RAW);
ASSERT_OK(r);
r = uv_read_start((uv_stream_t*)&tty_in, tty_raw_alloc, tty_raw_read);
ASSERT_OK(r);
r = uv_read_stop((uv_stream_t*) &tty_in);
ASSERT_OK(r);
MAKE_VALGRIND_HAPPY(uv_default_loop());
return 0;
}
#endif
TEST_IMPL(tty_file) {
#ifndef _WIN32
uv_loop_t loop;
uv_tty_t tty;
uv_tty_t tty_ro;
uv_tty_t tty_wo;
int fd;
ASSERT_OK(uv_loop_init(&loop));
fd = open("test/fixtures/empty_file", O_RDONLY);
if (fd != -1) {
ASSERT_EQ(UV_EINVAL, uv_tty_init(&loop, &tty, fd, 1));
ASSERT_OK(close(fd));
/* test EBADF handling */
ASSERT_EQ(UV_EINVAL, uv_tty_init(&loop, &tty, fd, 1));
}
/* Bug on AIX where '/dev/random' returns 1 from isatty() */
#ifndef _AIX
fd = open("/dev/random", O_RDONLY);
if (fd != -1) {
ASSERT_EQ(UV_EINVAL, uv_tty_init(&loop, &tty, fd, 1));
ASSERT_OK(close(fd));
}
#endif /* _AIX */
fd = open("/dev/zero", O_RDONLY);
if (fd != -1) {
ASSERT_EQ(UV_EINVAL, uv_tty_init(&loop, &tty, fd, 1));
ASSERT_OK(close(fd));
}
fd = open("/dev/tty", O_RDWR);
if (fd != -1) {
ASSERT_OK(uv_tty_init(&loop, &tty, fd, 1));
ASSERT_OK(close(fd)); /* TODO: it's indeterminate who owns fd now */
ASSERT(uv_is_readable((uv_stream_t*) &tty));
ASSERT(uv_is_writable((uv_stream_t*) &tty));
uv_close((uv_handle_t*) &tty, NULL);
ASSERT(!uv_is_readable((uv_stream_t*) &tty));
ASSERT(!uv_is_writable((uv_stream_t*) &tty));
}
fd = open("/dev/tty", O_RDONLY);
if (fd != -1) {
ASSERT_OK(uv_tty_init(&loop, &tty_ro, fd, 1));
ASSERT_OK(close(fd)); /* TODO: it's indeterminate who owns fd now */
ASSERT(uv_is_readable((uv_stream_t*) &tty_ro));
ASSERT(!uv_is_writable((uv_stream_t*) &tty_ro));
uv_close((uv_handle_t*) &tty_ro, NULL);
ASSERT(!uv_is_readable((uv_stream_t*) &tty_ro));
ASSERT(!uv_is_writable((uv_stream_t*) &tty_ro));
}
fd = open("/dev/tty", O_WRONLY);
if (fd != -1) {
ASSERT_OK(uv_tty_init(&loop, &tty_wo, fd, 0));
ASSERT_OK(close(fd)); /* TODO: it's indeterminate who owns fd now */
ASSERT(!uv_is_readable((uv_stream_t*) &tty_wo));
ASSERT(uv_is_writable((uv_stream_t*) &tty_wo));
uv_close((uv_handle_t*) &tty_wo, NULL);
ASSERT(!uv_is_readable((uv_stream_t*) &tty_wo));
ASSERT(!uv_is_writable((uv_stream_t*) &tty_wo));
}
ASSERT_OK(uv_run(&loop, UV_RUN_DEFAULT));
MAKE_VALGRIND_HAPPY(&loop);
#endif
return 0;
}
TEST_IMPL(tty_pty) {
/* TODO(gengjiawen): Fix test on QEMU. */
#if defined(__QEMU__)
RETURN_SKIP("Test does not currently work in QEMU");
#endif
#if defined(__APPLE__) || \
defined(__DragonFly__) || \
defined(__FreeBSD__) || \
(defined(__linux__) && !defined(__ANDROID__)) || \
defined(__NetBSD__) || \
defined(__OpenBSD__)
int master_fd, slave_fd, r;
uv_loop_t loop;
uv_tty_t master_tty, slave_tty;
r = openpty(&master_fd, &slave_fd, NULL, NULL, NULL);
if (r != 0)
RETURN_SKIP("No pty available, skipping.");
ASSERT_OK(uv_loop_init(&loop));
ASSERT_OK(uv_tty_init(&loop, &slave_tty, slave_fd, 0));
ASSERT_OK(uv_tty_init(&loop, &master_tty, master_fd, 0));
ASSERT(uv_is_readable((uv_stream_t*) &slave_tty));
ASSERT(uv_is_writable((uv_stream_t*) &slave_tty));
ASSERT(uv_is_readable((uv_stream_t*) &master_tty));
ASSERT(uv_is_writable((uv_stream_t*) &master_tty));
/* Check if the file descriptor was reopened. If it is,
* UV_HANDLE_BLOCKING_WRITES (value 0x100000) isn't set on flags.
*/
ASSERT_OK((slave_tty.flags & 0x100000));
/* The master_fd of a pty should never be reopened.
*/
ASSERT(master_tty.flags & 0x100000);
ASSERT_OK(close(slave_fd));
uv_close((uv_handle_t*) &slave_tty, NULL);
ASSERT_OK(close(master_fd));
uv_close((uv_handle_t*) &master_tty, NULL);
ASSERT_OK(uv_run(&loop, UV_RUN_DEFAULT));
MAKE_VALGRIND_HAPPY(&loop);
#endif
return 0;
}
#if !defined(__ANDROID__) && !defined(_WIN32)
static int tty_pty_partial_read_count;
static void tty_pty_partial_feeder(void *arg) {
static char buf[1<<13];
ssize_t n;
ssize_t r;
int fd;
int i;
fd = *(int *)arg;
memset(buf, 'x', sizeof(buf));
for (i = 0; i < 8; i++) {
for (n = 0; n < (int) sizeof(buf); n += r) {
do
r = write(fd, &buf[n], sizeof(buf) - n);
while (r == -1 && errno == EINTR);
ASSERT_GT(r, 0);
}
}
ASSERT_OK(close(fd));
}
static void tty_pty_partial_alloc_cb(uv_handle_t* handle,
size_t suggested_size,
uv_buf_t *buf) {
static char slab[1<<16];
*buf = uv_buf_init(slab, sizeof(slab));
}
static void tty_pty_partial_read_cb(uv_stream_t* stream,
ssize_t nread,
const uv_buf_t *buf) {
if (nread > 0)
tty_pty_partial_read_count += nread;
else
uv_close((uv_handle_t*) stream, NULL);
}
#endif /* !defined(__ANDROID__) && !defined(_WIN32) */
TEST_IMPL(tty_pty_partial) {
#if !defined(__ANDROID__) && !defined(_WIN32)
int master_fd, slave_fd;
uv_tty_t master_tty;
uv_thread_t tid;
uv_loop_t loop;
int i;
/* This test is not 100% deterministic. If the bug it is testing for is
* present, then it fails about 1 in 3 times, that's why it runs in a loop.
*/
for (i = 0; i < 10; i++) {
if (openpty(&master_fd, &slave_fd, NULL, NULL, NULL))
RETURN_SKIP("No pty available, skipping.");
tty_pty_partial_read_count = 0;
ASSERT_OK(uv_loop_init(&loop));
ASSERT_OK(uv_tty_init(&loop, &master_tty, master_fd, 0));
ASSERT_OK(uv_read_start((uv_stream_t*) &master_tty,
tty_pty_partial_alloc_cb,
tty_pty_partial_read_cb));
ASSERT(uv_is_readable((uv_stream_t*) &master_tty));
ASSERT(uv_is_writable((uv_stream_t*) &master_tty));
ASSERT_OK(uv_thread_create(&tid, tty_pty_partial_feeder, &slave_fd));
ASSERT_OK(uv_run(&loop, UV_RUN_DEFAULT));
ASSERT_OK(uv_thread_join(&tid));
ASSERT_EQ(tty_pty_partial_read_count, 65536);
MAKE_VALGRIND_HAPPY(&loop);
}
#endif
return 0;
}