am c02d6add: am 6cbc56b8: Merge "Implement <pty.h>."

* commit 'c02d6add2d12ada65cc88db724921d23be6e3310':
  Implement <pty.h>.

libc/bionic/pty.cpp

@@ -28,13 +28,15 @@
 
 #include <errno.h>
 #include <fcntl.h>
+#include <pty.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/ioctl.h>
 #include <termios.h>
 #include <unistd.h>
+#include <utmp.h>
 
-int getpt(void) {
+int getpt() {
   return posix_openpt(O_RDWR|O_NOCTTY);
 }
 
@@ -47,7 +49,7 @@ int posix_openpt(int flags) {
 }
 
 char* ptsname(int fd) {
-  static char buf[64];
+  static char buf[32];
   return ptsname_r(fd, buf, sizeof(buf)) == 0 ? buf : NULL;
 }
 
@@ -105,3 +107,83 @@ int unlockpt(int fd) {
   int unlock = 0;
   return ioctl(fd, TIOCSPTLCK, &unlock);
 }
+
+int openpty(int* master, int* slave, char* name, const termios* t, const winsize* ws) {
+  *master = getpt();
+  if (*master == -1) {
+    return -1;
+  }
+
+  if (grantpt(*master) == -1 || unlockpt(*master) == -1) {
+    close(*master);
+    return -1;
+  }
+
+  char buf[32];
+  if (name == NULL) {
+    name = buf;
+  }
+  if (ptsname_r(*master, name, sizeof(buf)) != 0) {
+    close(*master);
+    return -1;
+  }
+
+  *slave = open(name, O_RDWR|O_NOCTTY);
+  if (*slave == -1) {
+    close(*master);
+    return -1;
+  }
+
+  if (t != NULL) {
+    tcsetattr(*slave, TCSAFLUSH, t);
+  }
+  if (ws != NULL) {
+    ioctl(*slave, TIOCSWINSZ, ws);
+  }
+
+  return 0;
+}
+
+int forkpty(int* master, char* name, const termios* t, const winsize* ws) {
+  int slave;
+  if (openpty(master, &slave, name, t, ws) == -1) {
+    return -1;
+  }
+
+  pid_t pid = fork();
+  if (pid == -1) {
+    close(*master);
+    close(slave);
+    return -1;
+  }
+
+  if (pid == 0) {
+    // Child.
+    close(*master);
+    if (login_tty(slave) == -1) {
+      _exit(1);
+    }
+    return 0;
+  }
+
+  // Parent.
+  close(slave);
+  return pid;
+}
+
+int login_tty(int fd) {
+  setsid();
+
+  if (ioctl(fd, TIOCSCTTY, NULL) == -1) {
+    return -1;
+  }
+
+  dup2(fd, STDIN_FILENO);
+  dup2(fd, STDOUT_FILENO);
+  dup2(fd, STDERR_FILENO);
+  if (fd > STDERR_FILENO) {
+    close(fd);
+  }
+
+  return 0;
+}

libc/include/pty.h

@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2014 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.
+ */
+
+#ifndef _PTY_H
+#define _PTY_H
+
+#include <sys/cdefs.h>
+
+#include <termios.h>
+#include <sys/ioctl.h>
+
+__BEGIN_DECLS
+
+int openpty(int*, int*, char*, const struct termios*, const struct winsize*);
+int forkpty(int*, char*, const struct termios*, const struct winsize*);
+
+__END_DECLS
+
+#endif /* _PTY_H */

libc/include/utmp.h

@@ -91,6 +91,8 @@ int utmpname(const char*);
 void setutent();
 struct utmp* getutent();
 
+int login_tty(int);
+
 __END_DECLS
 
 #endif /* _UTMP_H_ */