platform_bionic/libc/bionic/pty.cpp
Elliott Hughes 4916706cfe Fix linkage of grantpt(3).
Also clean up the implementation of all the pty functions, add tests,
and fix the stub implementations of ttyname(3) and ttyname_r(3).

Bug: https://code.google.com/p/android/issues/detail?id=58888
Change-Id: I0fb36438cd1abf8d4e87c29415f03db9ba13c3c2
2014-07-25 19:55:23 -07:00

107 lines
2.7 KiB
C++

/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <termios.h>
#include <unistd.h>
int getpt(void) {
return posix_openpt(O_RDWR|O_NOCTTY);
}
int grantpt(int) {
return 0;
}
int posix_openpt(int flags) {
return open("/dev/ptmx", flags);
}
char* ptsname(int fd) {
static char buf[64];
return ptsname_r(fd, buf, sizeof(buf)) == 0 ? buf : NULL;
}
int ptsname_r(int fd, char* buf, size_t len) {
if (buf == NULL) {
errno = EINVAL;
return errno;
}
unsigned int pty_num;
if (ioctl(fd, TIOCGPTN, &pty_num) != 0) {
errno = ENOTTY;
return errno;
}
if (snprintf(buf, len, "/dev/pts/%u", pty_num) >= static_cast<int>(len)) {
errno = ERANGE;
return errno;
}
return 0;
}
char* ttyname(int fd) {
static char buf[64];
return ttyname_r(fd, buf, sizeof(buf)) == 0 ? buf : NULL;
}
int ttyname_r(int fd, char* buf, size_t len) {
if (buf == NULL) {
errno = EINVAL;
return errno;
}
if (!isatty(fd)) {
return errno;
}
char path[64];
snprintf(path, sizeof(path), "/proc/self/fd/%d", fd);
ssize_t count = readlink(path, buf, len);
if (count == -1) {
return errno;
}
if (static_cast<size_t>(count) == len) {
errno = ERANGE;
return errno;
}
buf[count] = '\0';
return 0;
}
int unlockpt(int fd) {
int unlock = 0;
return ioctl(fd, TIOCSPTLCK, &unlock);
}