| /* |
| * Copyright (C) 2013 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #define LOG_TAG "forkpty" |
| |
| #include <utils/Log.h> |
| |
| #include <fcntl.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <sys/ioctl.h> |
| #include <termios.h> |
| #include <unistd.h> |
| |
| #include "forkpty.h" |
| |
| pid_t forkpty(int *master, int *slave, const struct termios *termp, |
| const struct winsize *winp) { |
| int ptm = open("/dev/ptmx", O_RDWR); |
| if (ptm < 0) { |
| ALOGE("cannot open /dev/ptmx - %s", strerror(errno)); |
| return -1; |
| } |
| fcntl(ptm, F_SETFD, FD_CLOEXEC); |
| |
| char *devname; |
| if (grantpt(ptm) || unlockpt(ptm) || ((devname = (char *) ptsname(ptm)) == 0)) { |
| ALOGE("error opening pty - %s", strerror(errno)); |
| return -1; |
| } |
| |
| int pts = open(devname, O_RDWR); |
| if (pts < 0) { |
| ALOGE("unable to open slave pty - %s", strerror(errno)); |
| return -1; |
| } |
| |
| if (termp) { |
| tcsetattr(pts, TCSAFLUSH, termp); |
| } |
| |
| if (winp) { |
| ioctl(pts, TIOCSWINSZ, winp); |
| } |
| |
| pid_t pid = fork(); |
| |
| if (pid < 0) { |
| ALOGE("fork failed - %s", strerror(errno)); |
| return -1; |
| } |
| |
| if (pid == 0) { |
| setsid(); |
| if (ioctl(pts, TIOCSCTTY, (char *)NULL) == -1) exit(-1); |
| dup2(pts, STDIN_FILENO); |
| dup2(pts, STDOUT_FILENO); |
| dup2(pts, STDERR_FILENO); |
| if (pts > 2) { |
| close(pts); |
| } |
| } else { |
| *master = ptm; |
| if (slave) { |
| *slave = pts; |
| } |
| } |
| return pid; |
| } |
| |