97 lines
1.9 KiB
C
97 lines
1.9 KiB
C
/*
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* Project Acrn
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* Acrn-dm-pty
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*
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* Copyright (C) 2019 Intel Corporation. All rights reserved.
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*
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* SPDX-License-Identifier: BSD-3-Clause
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*
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <sys/stat.h>
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#include <dirent.h>
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#include <termios.h>
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#include <stdbool.h>
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#include <libgen.h>
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#include "log.h"
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/*
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* Check and create the directory.
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* To avoid symlink failure if the directory does not exist.
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*/
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static int check_dir(const char *file)
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{
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char *tmp, *dir;
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tmp = strdup(file);
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if (!tmp) {
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pr_err("failed to dup file, error:%s\n", strerror(errno));
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return -1;
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}
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dir = dirname(tmp);
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if (access(dir, F_OK) && mkdir(dir, 0666)) {
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pr_err("failed to create dir:%s, erorr:%s\n", dir, strerror(errno));
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free(tmp);
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return -1;
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}
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free(tmp);
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return 0;
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}
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/*
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* Open PTY master device to used by caller and the PTY slave device for virtual
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* UART. The pair(master/slave) can work as a communication channel between
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* the caller and virtual UART.
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*/
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int pty_open_virtual_uart(const char *dev_name)
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{
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int fd;
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char *slave_name;
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struct termios attr;
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fd = open("/dev/ptmx", O_RDWR | O_NOCTTY | O_NONBLOCK);
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if (fd < 0)
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goto open_err;
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if (grantpt(fd) < 0)
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goto pty_err;
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if (unlockpt(fd) < 0)
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goto pty_err;
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slave_name = ptsname(fd);
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if (!slave_name)
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goto pty_err;
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if ((unlink(dev_name) < 0) && errno != ENOENT)
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goto pty_err;
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/*
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* The check_dir restriction is that only create one directory
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* not support multi-level directroy.
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*/
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if (check_dir(dev_name) < 0)
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goto pty_err;
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if (symlink(slave_name, dev_name) < 0)
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goto pty_err;
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if (chmod(dev_name, 0660) < 0)
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goto attr_err;
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if (tcgetattr(fd, &attr) < 0)
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goto attr_err;
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cfmakeraw(&attr);
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attr.c_cflag |= CLOCAL;
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if (tcsetattr(fd, TCSANOW, &attr) < 0)
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goto attr_err;
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return fd;
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attr_err:
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unlink(dev_name);
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pty_err:
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close(fd);
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open_err:
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return -1;
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}
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