nuttx-apps/nshlib/nsh_altconsole.c
Xiang Xiao 75455d3788 nshlib: Reuse nsh_session logic in nsh_telnetmain
to avoid the code duplication

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
2022-10-17 09:41:43 -03:00

287 lines
7.5 KiB
C

/****************************************************************************
* apps/nshlib/nsh_altconsole.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <assert.h>
#include <debug.h>
#include "nsh.h"
#include "nsh_console.h"
#if defined(CONFIG_NSH_ALTCONDEV) && !defined(HAVE_USB_CONSOLE)
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: nsh_clone_console
*
* Description:
* Clone stdout and stderr to alternatives devices
*
****************************************************************************/
static int nsh_clone_console(FAR struct console_stdio_s *pstate)
{
int fd;
/* Open the alternative standard error device */
fd = open(CONFIG_NSH_ALTSTDERR, O_WRONLY);
if (fd < 0)
{
return -ENODEV;
}
/* Flush stderr: we only flush stderr if we opened the alternative one */
fflush(stderr);
/* Associate the new opened file descriptor to stderr */
dup2(fd, 2);
/* Close the console device that we just opened */
if (fd != 0)
{
close(fd);
}
/* Open the alternative standard output device */
fd = open(CONFIG_NSH_ALTSTDOUT, O_WRONLY);
if (fd < 0)
{
return -ENODEV;
}
/* Flush stdout: we only flush stdout if we opened the alternative one */
fflush(stdout);
/* Associate the new opened file descriptor to stdout */
dup2(fd, 1);
/* Close the console device that we just opened */
if (fd != 0)
{
close(fd);
}
/* Setup the stderr */
pstate->cn_errfd = 2;
pstate->cn_errstream = fdopen(pstate->cn_errfd, "a");
if (!pstate->cn_errstream)
{
free(pstate);
return -EIO;
}
/* Setup the stdout */
pstate->cn_outfd = 1;
pstate->cn_outstream = fdopen(pstate->cn_outfd, "a");
if (!pstate->cn_outstream)
{
free(pstate);
return -EIO;
}
return OK;
}
/****************************************************************************
* Name: nsh_wait_inputdev
*
* Description:
* Wait for the input device to be ready
*
****************************************************************************/
static int nsh_wait_inputdev(FAR struct console_stdio_s *pstate,
FAR const char *msg)
{
int fd;
/* Don't start the NSH console until the input device is ready. Chances
* are, we get here with no functional stdin. For example a USB keyboard
* device will not be available until the device is connected to the host
* and enumerated.
*/
/* Open the USB keyboard device for read-only access */
do
{
/* Try to open the alternative stdin device */
fd = open(CONFIG_NSH_ALTSTDIN, O_RDWR);
if (fd < 0)
{
#ifdef CONFIG_DEBUG_FEATURES
int errcode = errno;
/* ENOENT means that the USB device is not yet connected and,
* hence, has no entry under /dev. If the USB driver still
* exists under /dev (because other threads still have the driver
* open), then we might also get ENODEV. Anything else would
* be really bad.
*/
DEBUGASSERT(errcode == ENOENT || errcode == ENODEV);
#endif
/* Let the user know that we are waiting */
if (msg)
{
/* Show the waiting message only one time after the failure
* to open the keyboard device.
*/
puts(msg);
fflush(stdout);
msg = NULL;
}
/* Sleep a bit and try again */
sleep(2);
}
}
while (fd < 0);
/* Okay.. we have successfully opened the input device. Did
* we just re-open fd 0?
*/
if (fd != 0)
{
/* No.. Dup the fd to create standard fd 0. stdin should not know. */
dup2(fd, 0);
/* Setup the input console */
pstate->cn_confd = 0;
/* Create a standard C stream on the console device */
pstate->cn_constream = fdopen(pstate->cn_confd, "r+");
if (!pstate->cn_constream)
{
free(pstate);
return -EIO;
}
/* Close the input device that we just opened */
close(fd);
}
return OK;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nsh_consolemain (USB console version)
*
* Description:
* This interfaces maybe to called or started with task_start to start a
* single an NSH instance that operates on stdin and stdout. This
* function does not return.
*
* This function handles generic /dev/console character devices for output
* but uses a special USB keyboard device for input. The USB keyboard
* requires some special operations to handle the cases where the session
* input is lost when the USB keyboard is unplugged and restarted when the
* USB keyboard is plugged in again.
*
* Input Parameters:
* Standard task start-up arguments. These are not used. argc may be
* zero and argv may be NULL.
*
* Returned Values:
* This function does not return nor does it ever exit (unless the user
* executes the NSH exit command).
*
****************************************************************************/
int nsh_consolemain(int argc, FAR char *argv[])
{
FAR struct console_stdio_s *pstate = nsh_newconsole(true);
FAR const char *msg;
int ret;
DEBUGASSERT(pstate);
/* First map stderr and stdout to alternative devices */
ret = nsh_clone_console(pstate);
if (ret < 0)
{
return ret;
}
/* Now loop, executing creating a session for each USB connection */
msg = "Waiting for a keyboard...\n";
for (; ; )
{
/* Wait for the USB to be connected to the host and switch
* standard I/O to the USB serial device.
*/
ret = nsh_wait_inputdev(pstate, msg);
DEBUGASSERT(ret == OK);
UNUSED(ret);
/* Execute the session */
nsh_session(pstate, NSH_LOGIN_LOCAL, argc, argv);
/* We lost the connection. Wait for the keyboard to
* be re-connected.
*/
msg = "Please re-connect the keyboard...\n";
}
}
#endif /* HAVE_USB_KEYBOARD && !HAVE_USB_CONSOLE */