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
diff --git a/libc/bionic/pty.cpp b/libc/bionic/pty.cpp
new file mode 100644
index 0000000..995e006
--- /dev/null
+++ b/libc/bionic/pty.cpp
@@ -0,0 +1,107 @@
+/*
+ * 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);
+}