Add some basic SYSLOG channel selection logic

drivers/syslog/Make.defs

@@ -35,60 +35,42 @@
 ############################################################################
 
 ############################################################################
-# Include SYSLOG drivers (only one should be enabled)
+# Include SYSLOG Infrastructure
 
-ifeq ($(CONFIG_SYSLOG),y)
+CSRCS += syslog_channel.c
 
-# If no special loggin devices are implemented, then the default SYSLOG
+ifeq ($(CONFIG_SYSLOG_INTBUFFER),y)
-# logic at fs/fs_syslog.c will be used
+  CSRCS += syslog_intbuffer.c
-
-# (Add other SYSLOG drivers here)
-
-ifeq ($(CONFIG_RAMLOG),y)
-  CSRCS += ramlog.c
 endif
 
+# The note driver is hosted in this directory, but is not associated with
+# SYSLOGging
+
 ifeq ($(CONFIG_DRIVER_NOTE),y)
   CSRCS += note_driver.c
 endif
 
-# (Add other SYSLOG_CONSOLE drivers here)
+############################################################################
+# Include SYSLOG drivers (only one should be enabled)
+
+ifeq ($(CONFIG_RAMLOG),y)
+  CSRCS += ramlog.c
+else ifeq ($(CONFIG_SYSLOG),y)
+
+# If no special logging devices are implemented, then the default SYSLOG
+# logic at fs/fs_syslog.c will be used
+
+# (Add other SYSLOG drivers here)
 
 ifeq ($(CONFIG_SYSLOG_CONSOLE),y)
   CSRCS += syslog_console.c
 endif
 
+# (Add other SYSLOG_CONSOLE drivers here)
+
+endif
+
 # Include SYSLOG build support
 
 DEPPATH += --dep-path syslog
 VPATH += :syslog
-
-############################################################################
-# The RAMLOG can be used even if system logging is not enabled.
-
-else ifeq ($(CONFIG_RAMLOG),y)
-
-CSRCS += ramlog.c
-
-ifeq ($(CONFIG_DRIVER_NOTE),y)
-  CSRCS += note_driver.c
-endif
-
-# Include RAMLOG build support
-
-DEPPATH += --dep-path syslog
-VPATH += :syslog
-
-############################################################################
-# The scheduler note driver can be used in any event.
-
-else ifeq ($(CONFIG_DRIVER_NOTE),y)
-
-CSRCS += note_driver.c
-
-# Include note driver build support
-
-DEPPATH += --dep-path syslog
-VPATH += :syslog
-
-endif

drivers/syslog/syslog.h

@@ -0,0 +1,126 @@
+/****************************************************************************
+ * drivers/syslog/syslog.h
+ *
+ *   Copyright (C) 2016 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * 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 __DRIVERS_SYSLOG_SYSLOG_H
+#define __DRIVERS_SYSLOG_SYSLOG_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+#ifndef __ASSEMBLY__
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: syslog_add_intbuffer
+ *
+ * Description:
+ *   Add one more character to the interrupt buffer.  In the event of
+ *   buffer overlowed, 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:
+ *   channel - The syslog channel to use in performing the flush operation.
+ *   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(FAR const struct syslog_channel_s *channel,
+                           bool force);
+#endif
+
+#undef EXTERN
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __ASSEMBLY__ */
+#endif /* __DRIVERS_SYSLOG_SYSLOG_H */

drivers/syslog/syslog_channel.c

@@ -0,0 +1,207 @@
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <assert.h>
+#include <errno.h>
+
+#include <nuttx/syslog/syslog.h>
+
+#ifdef CONFIG_RAMLOG_SYSLOG
+#  include <nuttx/syslog/ramlog.h>
+#elif defined(CONFIG_ARCH_LOWPUTC)
+#  include <nuttx/arch.h>
+#endif
+
+#include "syslog.h"
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+#ifndef CONFIG_ARCH_LOWPUTC
+static int syslog_default_putc(int ch);
+#endif
+static int syslog_default_flush(void);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+#if defined(CONFIG_RAMLOG_SYSLOG)
+static const struct syslog_channel_s g_default_channel =
+{
+  ramlog_putc,
+  ramlog_putc,
+  syslog_default_flush
+};
+#elif defined(CONFIG_ARCH_LOWPUTC)
+static const struct syslog_channel_s g_default_channel =
+{
+  up_putc,
+  up_putc,
+  syslog_default_flush
+};
+#else
+static const struct syslog_channel_s g_default_channel =
+{
+  syslog_default_putc,
+  syslog_default_putc,
+  syslog_default_flush
+};
+#endif
+
+/* This is the current syslog channel in use */
+
+static FAR const struct syslog_channel_s *g_syslog_channel = &g_default_channel;
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+#ifndef CONFIG_ARCH_LOWPUTC
+static int syslog_default_putc(int ch)
+{
+  return ch;
+}
+#endif
+
+static int syslog_default_flush(void)
+{
+  return OK;
+}
+
+static int syslog_force(int ch)
+{
+  DEBUGASSERT(g_syslog_channel != NULL && g_syslog_channel->sc_force != NULL);
+
+  return g_syslog_channel->sc_force(ch);
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: syslog_channel
+ *
+ * Description:
+ *   Configure the SYSLOGging function to use the provided channel to
+ *   generate SYSLOG output.
+ *
+ * Input buffer:
+ *   channel - Provides the interface to the channel to be used.
+ *
+ * Returned Value:
+ *   Zero (OK)is returned on  success.  A negated errno value is returned
+ *   on any failure.
+ *
+ ****************************************************************************/
+
+int syslog_channel(FAR const struct syslog_channel_s *channel)
+{
+  DEBUGASSERT(channel != NULL);
+
+  if (channel != NULL)
+    {
+      DEBUGASSERT(channel->sc_putc != NULL && channel->sc_force != NULL &&
+                  channel->sc_flush != NULL);
+
+      g_syslog_channel = channel;
+      return OK;
+    }
+
+  return -EINVAL;
+}
+
+/****************************************************************************
+ * Name: syslog_putc
+ *
+ * Description:
+ *   This is the low-level 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)
+{
+  DEBUGASSERT(g_syslog_channel != NULL);
+
+  /* Is this an attempt to do SYSLOG output from an interrupt handler? */
+
+  if (up_interrupt_context())
+    {
+#ifdef CONFIG_SYSLOG_INTBUFFER
+      /* Buffer the character in the interrupt buffer.  The interrupt buffer
+       * will be flushed before the next normal, non-interrupt SYSLOG output.
+       */
+
+      return syslog_add_intbuffer(ch);
+#else
+      /* Force the character to the SYSLOG device immediately (if possible).
+       * This means that the interrupt data may not be in synchronization
+       * with output data that may have been buffered by sc_putc().
+       */
+
+      return syslog_force(ch);
+#endif
+    }
+  else
+    {
+      DEBUGASSERT(g_syslog_channel->sc_putc != NULL);
+
+#ifdef CONFIG_SYSLOG_INTBUFFER
+      /* Flush any characters that may have been added to the interrupt
+       * buffer.
+       */
+
+      (void)syslog_flush_intbuffer(&g_syslog_channel, false);
+#endif
+
+      return g_syslog_channel->sc_putc(ch);
+    }
+}
+
+/****************************************************************************
+ * Name: syslog_flush
+ *
+ * Description:
+ *   This is called by system crash-handling logic.  It must flush any
+ *   buffered data to the SYSLOG device.
+ *
+ *   Interrupts are disabled at the time of the crash and this logic must
+ *   perform the flush using low-level, non-interrupt driven logic.
+ *
+ * Input Parameters:
+ *   ch - The character to add to the SYSLOG (must be positive).
+ *
+ * Returned Value:
+ *   Zero (OK)is returned on  success.  A negated errno value is returned
+ *   on any failure.
+ *
+ ****************************************************************************/
+
+int syslog_flush(void)
+{
+  DEBUGASSERT(g_syslog_channel != NULL && g_syslog_channel->sc_flush != NULL);
+
+#ifdef CONFIG_SYSLOG_INTBUFFER
+  /* Flush any characters that may have been added to the interrupt
+   * buffer.
+   */
+
+  (void)syslog_flush_intbuffer(&g_syslog_channel, true);
+#endif
+
+  /* Then flush all of the buffered output to the SYSLOG device */
+
+  return g_syslog_channel->sc_flush();
+}

drivers/syslog/syslog_intbuffer.c

@@ -0,0 +1,115 @@
+/****************************************************************************
+ * drivers/syslog/syslog_intbuffer.c
+ *
+ *   Copyright (C) 2016 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * 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.
+ *
+ ****************************************************************************/
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <assert.h>
+
+#include <nuttx/syslog/syslog.h>
+
+#include "syslog.h"
+
+#ifdef CONFIG_SYSLOG_INTBUFFER
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: syslog_add_intbuffer
+ *
+ * Description:
+ *   Add one more character to the interrupt buffer.  In the event of
+ *   buffer overlowed, 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.
+ *
+ ****************************************************************************/
+
+int syslog_add_intbuffer(int ch)
+{
+#warning Missing logic
+  return -ENOSYS;
+}
+#endif
+
+/****************************************************************************
+ * Name: syslog_flush_intbuffer
+ *
+ * Description:
+ *   Flush any characters that may have been added to the interrupt buffer
+ *   to the SYSLOG device.
+ *
+ * Input Parameters:
+ *   channel - The syslog channel to use in performing the flush operation.
+ *   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.
+ *
+ ****************************************************************************/
+
+int syslog_flush_intbuffer(FAR const struct syslog_channel_s *channel,
+                           bool force)
+{
+#warning Missing logic
+  return -ENOSYS;
+}
+
+#endif /* CONFIG_SYSLOG_INTBUFFER */

include/nuttx/syslog/syslog.h

@@ -2,7 +2,7 @@
  * include/nuttx/syslog/syslog.h
  * The NuttX SYSLOGing interface
  *
- *   Copyright (C) 2012, 2014-2015 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2012, 2014-2016 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -42,6 +42,7 @@
  ****************************************************************************/
 
 #include <nuttx/config.h>
+#include <nuttx/compiler.h>
 
 /****************************************************************************
  * Pre-processor Definitions
@@ -79,6 +80,23 @@
 #  define CONFIG_SYSLOG_DEVPATH "/dev/ttyS1"
 #endif
 
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+/* This structure provides the interface to a SYSLOG device */
+
+struct syslog_channel_s
+{
+  /* I/O redirection methods */
+
+  CODE int (*sc_putc)(int ch);  /* Normal buffered output */
+  CODE int (*sc_force)(int ch); /* Low-level output for interrupt handlers */
+  CODE int (*sc_flush)(void);   /* Flush buffered output (on crash) */
+
+  /* Implementation specific logic may follow */
+};
+
 /****************************************************************************
  * Public Data
  ****************************************************************************/
@@ -96,6 +114,24 @@ extern "C"
 /****************************************************************************
  * Public Function Prototypes
  ****************************************************************************/
+/****************************************************************************
+ * Name: syslog_channel
+ *
+ * Description:
+ *   Configure the SYSLOGging function to use the provided channel to
+ *   generate SYSLOG output.
+ *
+ * Input buffer:
+ *   channel - Provides the interface to the channel to be used.
+ *
+ * Returned Value:
+ *   Zero (OK)is returned on  success.  A negated errno value is returned
+ *   on any failure.
+ *
+ ****************************************************************************/
+
+int syslog_channel(FAR const struct syslog_channel_s *channel);
+
 /****************************************************************************
  * Name: syslog_initialize
  *
@@ -106,6 +142,13 @@ extern "C"
  *   NOTE that this implementation excludes using a network connection as
  *   SYSLOG device.  That would be a good extension.
  *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   Zero (OK)is returned on  success.  A negated errno value is returned
+ *   on any failure.
+ *
  ****************************************************************************/
 
 #ifdef CONFIG_SYSLOG_CHAR
@@ -116,17 +159,39 @@ int syslog_initialize(void);
  * Name: syslog_putc
  *
  * Description:
- *   This is the low-level system logging interface.  The debugging/syslogging
+ *   This is the low-level system logging interface.
- *   interfaces are syslog() and lowsyslog().  The difference is that
+ *
- *   the syslog() internface writes to fd=1 (stdout) whereas lowsyslog() uses
+ * Input Parameters:
- *   a lower level interface that works from interrupt handlers.  This
+ *   ch - The character to add to the SYSLOG (must be positive).
- *   function is the low-level interface used to implement lowsyslog().
+ *
+ * Returned Value:
+ *   On success, the character is echoed back to the caller.  A negated
+ *   errno value is returned on any failure.
  *
  ****************************************************************************/
 
-#ifdef CONFIG_SYSLOG
 int syslog_putc(int ch);
-#endif
+
+/****************************************************************************
+ * Name: syslog_flush
+ *
+ * Description:
+ *   This is called by system crash-handling logic.  It must flush any
+ *   buffered data to the SYSLOG device.
+ *
+ *   Interrupts are disabled at the time of the crash and this logic must
+ *   perform the flush using low-level, non-interrupt driven logic.
+ *
+ * Input Parameters:
+ *   ch - The character to add to the SYSLOG (must be positive).
+ *
+ * Returned Value:
+ *   Zero (OK)is returned on  success.  A negated errno value is returned
+ *   on any failure.
+ *
+ ****************************************************************************/
+
+int syslog_flush(void);
 
 #undef EXTERN
 #ifdef __cplusplus