nuttx/drivers/syslog/syslog.h
anjiahao 41c3b42468 change /dev/syslog & /dev/ramlog for unix standard
Signed-off-by: anjiahao <anjiahao@xiaomi.com>
2021-11-24 05:19:46 -06:00

288 lines
9.8 KiB
C

/****************************************************************************
* drivers/syslog/syslog.h
*
* 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.
*
****************************************************************************/
#ifndef __DRIVERS_SYSLOG_SYSLOG_H
#define __DRIVERS_SYSLOG_SYSLOG_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdbool.h>
/****************************************************************************
* Public Data
****************************************************************************/
#ifndef __ASSEMBLY__
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/* This is the current syslog channel in use. It initially points to
* g_default_channel.
*/
struct syslog_channel_s; /* Forward reference */
EXTERN FAR struct syslog_channel_s *g_syslog_channel
[CONFIG_SYSLOG_MAX_CHANNELS];
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
/****************************************************************************
* Name: syslog_dev_initialize
*
* Description:
* Initialize to use the character device (or file) at
* CONFIG_SYSLOG_DEVPATH as the SYSLOG sink.
*
* One power up, the SYSLOG facility is non-existent or limited to very
* low-level output. This function may be called later in the
* initialization sequence after full driver support has been initialized.
* (via syslog_initialize()) It installs the configured SYSLOG drivers
* and enables full SYSLOGing capability.
*
* NOTE that this implementation excludes using a network connection as
* SYSLOG device. That would be a good extension.
*
* Input Parameters:
* devpath - The full path to the character device to be used.
* oflags - File open flags.
* mode - File open mode (only if oflags include O_CREAT).
*
* Returned Value:
* Returns a newly created SYSLOG channel, or NULL in case of any failure.
*
****************************************************************************/
FAR struct syslog_channel_s *syslog_dev_initialize(FAR const char *devpath,
int oflags, int mode);
/****************************************************************************
* Name: syslog_dev_uninitialize
*
* Description:
* Called to disable the last device/file channel in preparation to use
* a different SYSLOG device. Currently only used for CONFIG_SYSLOG_FILE.
*
* Input Parameters:
* channel - Handle to syslog channel to be used.
*
* Assumptions:
* The caller has already switched the SYSLOG source to some safe channel
* (the default channel).
*
****************************************************************************/
void syslog_dev_uninitialize(FAR struct syslog_channel_s *channel);
/****************************************************************************
* Name: syslog_dev_channel
*
* Description:
* Configure to use the character device (or file) at
* CONFIG_SYSLOG_DEVPATH as the SYSLOG channel.
*
* This tiny function is simply a wrapper around syslog_dev_initialize()
* and syslog_channel(). It calls syslog_dev_initialize() to configure
* the character device at CONFIG_SYSLOG_DEVPATH then calls
* syslog_channel() to use that device as the SYSLOG output channel.
*
* NOTE interrupt level SYSLOG output will be lost in this case unless
* the interrupt buffer is used.
*
* Input Parameters:
* None
*
* Returned Value:
* A pointer to the new SYSLOG channel; NULL is returned on any failure.
*
****************************************************************************/
#ifdef CONFIG_SYSLOG_CHAR
FAR struct syslog_channel_s *syslog_dev_channel(void);
#endif
/****************************************************************************
* Name: syslog_console_channel
*
* Description:
* Configure to use the character device (or file) at /dev/console as the
* SYSLOG channel.
*
* This tiny function is simply a wrapper around syslog_dev_initialize()
* and syslog_channel(). It calls syslog_dev_initialize() to configure
* the character device at /dev/console then calls syslog_channel() to
* use that device as the SYSLOG output channel.
*
* NOTE interrupt level SYSLOG output will be lost in the general case
* unless the interrupt buffer is used. As a special case: If the serial
* console is used and the architecture provides up_putc(), the interrupt
* level output will be directed to up_putc() is the interrupt buffer is
* disabled.
*
* Input Parameters:
* None
*
* Returned Value:
* A pointer to the new SYSLOG channel; NULL is returned on any failure.
*
****************************************************************************/
#ifdef CONFIG_SYSLOG_CONSOLE
FAR struct syslog_channel_s *syslog_console_channel(void);
#endif
/****************************************************************************
* Name: syslog_register
*
* Description:
* Register a simple character driver at /dev/log whose write() method
* will transfer data to the SYSLOG device. This can be useful if, for
* example, you want to redirect the output of a program to the SYSLOG.
*
* NOTE that unlike other syslog output, this data is unformatted raw
* byte output with no time-stamping or any other SYSLOG features
* supported.
*
****************************************************************************/
#ifdef CONFIG_SYSLOG_CHARDEV
void syslog_register(void);
#endif
/****************************************************************************
* Name: syslog_add_intbuffer
*
* Description:
* Add one more character to the interrupt buffer. In the event of
* buffer overflowed, the character will be dropped. The indication
* "[truncated]\n" will be appended to the end of the interrupt buffer.
*
* Input Parameters:
* ch - The character to add to the interrupt buffer (must be positive).
*
* Returned Value:
* Zero success, the character is echoed back to the caller. A negated
* errno value is returned on any failure.
*
* Assumptions:
* Called only from interrupt handling logic; Interrupts will be disabled.
*
****************************************************************************/
#ifdef CONFIG_SYSLOG_INTBUFFER
int syslog_add_intbuffer(int ch);
#endif
/****************************************************************************
* Name: syslog_flush_intbuffer
*
* Description:
* Flush any characters that may have been added to the interrupt buffer
* to the SYSLOG device.
*
* Input Parameters:
* force - Use the force() method of the channel vs. the putc() method.
*
* Returned Value:
* On success, the character is echoed back to the caller. A negated
* errno value is returned on any failure.
*
* Assumptions:
* Interrupts may or may not be disabled.
*
****************************************************************************/
#ifdef CONFIG_SYSLOG_INTBUFFER
int syslog_flush_intbuffer(bool force);
#endif
/****************************************************************************
* Name: syslog_putc
*
* Description:
* This is the low-level, single character, system logging interface.
*
* Input Parameters:
* ch - The character to add to the SYSLOG (must be positive).
*
* Returned Value:
* On success, the character is echoed back to the caller. A negated
* errno value is returned on any failure.
*
****************************************************************************/
int syslog_putc(int ch);
/****************************************************************************
* Name: syslog_write
*
* Description:
* This is the low-level, multiple character, system logging interface.
*
* Input Parameters:
* buffer - The buffer containing the data to be output
* buflen - The number of bytes in the buffer
*
* Returned Value:
* On success, the number of characters written is returned. A negated
* errno value is returned on any failure.
*
****************************************************************************/
ssize_t syslog_write(FAR const char *buffer, size_t buflen);
/****************************************************************************
* Name: syslog_force
*
* Description:
* This is the low-level system logging interface. This version forces
* the output and is only used in emergency situations (e.g., in assertion
* handling).
*
* Input Parameters:
* ch - The character to add to the SYSLOG (must be positive).
*
* Returned Value:
* On success, the character is echoed back to the caller. A negated errno
* value is returned on any failure.
*
****************************************************************************/
int syslog_force(int ch);
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* __ASSEMBLY__ */
#endif /* __DRIVERS_SYSLOG_SYSLOG_H */