dnxPlugin.c File Reference

Utility routines to support plugin loading and execution. More...

#include "dnxPlugin.h"
#include "dnxError.h"
#include "dnxDebug.h"
#include "pfopen.h"
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#include <time.h>
#include <errno.h>
#include <unistd.h>
#include <sys/types.h>
#include <signal.h>
#include <poll.h>

Go to the source code of this file.

Data Structures

struct iDnxModule

The DNX module implementation data structure. More...

struct iDnxPlugin

The DNX plugin implementation data structure. More...

struct DnxPlugin

An abstract data type for a DNX plugin object. More...

struct DnxModule

An abstract data type for a DNX module object. More...

Defines

#define USE_POLL

#define MPLEXER   "poll"

#define elemcount(x)   (sizeof(x)/sizeof(*(x)))

#define MAX_PLUGIN_PREFIX   1024

The maximum plugin prefix.

#define MAX_PLUGIN_PATH   2048

The maximum plugin path.

#define DNX_MAX_ARGV   256

The maximum number of arguments.

#define MAX_INPUT_BUFFER   1024

The maximum input buffer.

#define DNX_MAX_PLUGIN_NAME   255

The maximum plugin name length.

Functions

static char * dnxFgets (char *data, int size, FILE *fp, int timeout)

Perform a time sensitive fgets.

static void strip (char *buf)

Strip leading and trailing whitespace from a specified string.

static int dnxPluginRegister (char *szPlugin, char *szErrMsg)

Register a dnx plugin with entry points.

static int dnxPluginLoad (DnxModule *module)

Load a dnx plugin module into memory.

static void dnxPluginUnload (DnxModule *module)

Unload a dnx plugin module from memory.

static int dnxPluginBaseName (char *command, char *baseName, int maxData)

Isolate the base name of a plugin command.

static int dnxPluginLocate (char *command, DnxPlugin **plugin)

Search for a plugin in the plugin chain.

static int dnxPluginVector (char *command, int *argc, char **argv, int maxargs)

Convert a dnx plugin string to a vector array.

static void dnxPluginInternal (DnxPlugin *plugin, char *command, int *resCode, char *resData, int maxData, int timeout, char *myaddr)

Executes an internal plugin module.

static void dnxPluginExternal (char *command, int *resCode, char *resData, int maxData, int timeout, char *myaddr)

Execute an external command line; capture stdout and stderr.

void dnxPluginExecute (char *command, int *resCode, char *resData, int maxData, int timeout, char *myaddr)

Find an appropriate dnx plugin and use it to execute a commmand.

int dnxPluginInit (char *pluginPath)

Initialize the dnx client plugin utility library.

void dnxPluginRelease (void)

Clean up the dnx plugin utility library.

Variables

static iDnxModule * gModules

The loaded module chain.

static iDnxPlugin * gPlugins

The loaded plugin chain.

static char * gPluginPath

The configured plugin path.

static int gInitialized = 0

The module initialization flag.

Detailed Description

Utility routines to support plugin loading and execution.

Author:: Robert W. Ingraham (dnx-devel@lists.sourceforge.net)
John Calcote (dnx-devel@lists.sourceforge.net)

Attention:: Please submit patches to http://dnx.sourceforge.net

Definition in file dnxPlugin.c.

Define Documentation

#define DNX_MAX_ARGV 256

The maximum number of arguments.

Definition at line 59 of file dnxPlugin.c.

Referenced by dnxPluginInternal().

#define DNX_MAX_PLUGIN_NAME 255

The maximum plugin name length.

Definition at line 61 of file dnxPlugin.c.

Referenced by dnxPluginLocate().

#define elemcount ( x ) (sizeof(x)/sizeof(*(x)))

Definition at line 55 of file dnxPlugin.c.

#define MAX_INPUT_BUFFER 1024

The maximum input buffer.

Definition at line 60 of file dnxPlugin.c.

Referenced by dnxPluginExternal(), dnxPluginInternal(), and neb_unload_module().

#define MAX_PLUGIN_PATH 2048

The maximum plugin path.

Definition at line 58 of file dnxPlugin.c.

Referenced by dnxPluginExternal().

#define MAX_PLUGIN_PREFIX 1024

The maximum plugin prefix.

Definition at line 57 of file dnxPlugin.c.

Referenced by dnxPluginInit().

#define MPLEXER "poll"

Definition at line 49 of file dnxPlugin.c.

Referenced by dnxPluginExternal().

#define USE_POLL

Definition at line 45 of file dnxPlugin.c.

Function Documentation

static char* dnxFgets	(	char *	data,
		int	size,
		FILE *	fp,
		int	timeout
	)			`[static]`

Perform a time sensitive fgets.

Parameters:

`[out]`	data	- the address of storage for returning data from `fp`.
`[in]`	size	- the maximum size of `data` in bytes.
`[in]`	fp	- the file pointer to be read.
`[in]`	timeout	- the maximum number of seconds to wait for data to be returned before failing with a timeout error.

Returns:: The address of data on success, or 0 on error.

Note:: Currently not used.

Definition at line 117 of file dnxPlugin.c.

static int dnxPluginBaseName	(	char *	command,
		char *	baseName,
		int	maxData
	)			`[static]`

Isolate the base name of a plugin command.

Parameters:

`[in]`	command	- the command for which to have the base name isolated.
`[out]`	baseName	- the address of storage for the returned base name.
`[in]`	maxData	- the maximum size of the `baseName` buffer.

Returns:: Zero on success, or a non-zero error value.

Definition at line 232 of file dnxPlugin.c.

References DNX_ERR_INVALID, DNX_ERR_MEMORY, and DNX_OK.

Referenced by dnxPluginLocate().

void dnxPluginExecute	(	char *	command,
		int *	resCode,
		char *	resData,
		int	maxData,
		int	timeout,
		char *	myaddr
	)

Find an appropriate dnx plugin and use it to execute a commmand.

Parameters:

`[in]`	command	- the command to be executed by the plugin.
`[out]`	resCode	- the address of storage for the command's result code.
`[out]`	resData	- the address of storage for the command's stdout text.
`[in]`	maxData	- the maximum size of the `resData` buffer.
`[in]`	timeout	- the maximum number of seconds to wait for `command` to complete before returning a timeout error.
`[in]`	myaddr	- the address (in human readable format) of this DNX node.

Definition at line 861 of file dnxPlugin.c.

References DNX_ERR_NOTFOUND, DNX_OK, DNX_PLUGIN_RESULT_UNKNOWN, dnxDebug(), dnxPluginExternal(), dnxPluginInternal(), dnxPluginLocate(), and gInitialized.

Referenced by dnxWorker().

static void dnxPluginExternal	(	char *	command,
		int *	resCode,
		char *	resData,
		int	maxData,
		int	timeout,
		char *	myaddr
	)			`[static]`

Execute an external command line; capture stdout and stderr.

Parameters:

`[in]`	command	- the command to be executed.
`[out]`	resCode	- the address of storage for the result code returned by `command`.
`[out]`	resData	- the resulting STDOUT text from the execution of `command`.
`[in]`	maxData	- the maximum size of the `resData` buffer.
`[in]`	timeout	- the maximum number of seconds to wait for `command` to complete before returning a timeout error.
`[in]`	myaddr	- the address (in human readable format) of this DNX node.

Definition at line 455 of file dnxPlugin.c.

References DNX_PLUGIN_RESULT_CRITICAL, DNX_PLUGIN_RESULT_UNKNOWN, elemcount, gInitialized, gPluginPath, MAX_INPUT_BUFFER, MAX_PLUGIN_PATH, MPLEXER, PF_ERR, PF_OUT, pfclose(), pfkill(), pfopen(), start_time, and strip().

Referenced by dnxPluginExecute().

int dnxPluginInit ( char * pluginPath )

Initialize the dnx client plugin utility library.

Parameters:

[in] pluginPath - the file system path where plugin libraries are to be found.

Returns:: Zero on success, or a non-zero error value.

Definition at line 887 of file dnxPlugin.c.

References DNX_ERR_INVALID, DNX_ERR_MEMORY, DNX_OK, dnxLog(), gInitialized, gPluginPath, MAX_PLUGIN_PREFIX, and xmalloc.

Referenced by ehProcessData(), and main().

static void dnxPluginInternal	(	DnxPlugin *	plugin,
		char *	command,
		int *	resCode,
		char *	resData,
		int	maxData,
		int	timeout,
		char *	myaddr
	)			`[static]`

Executes an internal plugin module.

Parameters:

`[in]`	plugin	- the plugin module to execute against `command`.
`[in]`	command	- the command to have `plugin` execute.
`[out]`	resCode	- the address of storage for the result code returned by `plugin`.
`[out]`	resData	- the resulting STDOUT text from the execution of `command` by `plugin`.
`[in]`	maxData	- the maximum size of the `resData` buffer.
`[in]`	timeout	- the maximum number of seconds to wait for `plugin` to complete execution of `command` before returning a timeout error.
`[in]`	myaddr	- the address (in human readable format) of this DNX node.

Todo:: Validate plugin parameter.

Todo:: Invoke plugin entry-point via DnxPlugin structure.

Definition at line 370 of file dnxPlugin.c.

References DNX_MAX_ARGV, DNX_OK, DNX_PLUGIN_RESULT_UNKNOWN, dnxPluginVector(), gInitialized, and MAX_INPUT_BUFFER.

Referenced by dnxPluginExecute().

static int dnxPluginLoad ( DnxModule * module ) [static]

Load a dnx plugin module into memory.

Parameters:

[in] module - the name of the module to be loaded.

Returns:: Zero on success, or a non-zero error value.

Note:: Currently not used.

Definition at line 199 of file dnxPlugin.c.

References DNX_OK, and gInitialized.

static int dnxPluginLocate	(	char *	command,
		DnxPlugin **	plugin
	)			`[static]`

Search for a plugin in the plugin chain.

Parameters:

`[in]`	command	- the command to be executed.
`[out]`	plugin	- the address of storage for the located plugin to be returned.

Returns:: Zero on success, or a non-zero error value.

Todo:: Search plugin chain.

Definition at line 275 of file dnxPlugin.c.

References DNX_ERR_NOTFOUND, DNX_MAX_PLUGIN_NAME, DNX_OK, dnxPluginBaseName(), and gInitialized.

Referenced by dnxPluginExecute().

static int dnxPluginRegister	(	char *	szPlugin,
		char *	szErrMsg
	)			`[static]`

Register a dnx plugin with entry points.

Parameters:

`[in]`	szPlugin	- the name of the plugin to be registered.
`[in]`	szErrMsg	- an error message to be displayed if the plugin could not be registered.

Returns:: Zero on success, or a non-zero error value.

Note:: Currently not used.

Definition at line 183 of file dnxPlugin.c.

References DNX_OK, and gInitialized.

void dnxPluginRelease ( void )

Clean up the dnx plugin utility library.

Todo:: Release module and plugin chains.

Definition at line 929 of file dnxPlugin.c.

References gInitialized, gPluginPath, and xfree.

Referenced by main().

static void dnxPluginUnload ( DnxModule * module ) [static]

Unload a dnx plugin module from memory.

Parameters:

[in] module - the name of the module to be unloaded.

Note:: Currently not used.

Definition at line 215 of file dnxPlugin.c.

References gInitialized.

static int dnxPluginVector	(	char *	command,
		int *	argc,
		char **	argv,
		int	maxargs
	)			`[static]`

Convert a dnx plugin string to a vector array.

The command buffer is modified such that each command argument is null-terminated on return.

Parameters:

`[in]`	command	- the string to be converted.
`[out]`	argc	- the address of storage for the number of elements actually returned in `argv`.
`[out]`	argv	- the address of storage for returning a null-terminated array of pointers to white-space-separated arguments in `command`.
`[in]`	maxargs	- the maximum number of entries in the `argv` array.

Returns:: Zero on success, or a non-zero error value.

Definition at line 313 of file dnxPlugin.c.

References DNX_ERR_MEMORY, DNX_OK, and xmalloc.

Referenced by dnxPluginInternal().

static void strip ( char * buf ) [static]

Strip leading and trailing whitespace from a specified string.

Leading white space is removed by moving all text from the first non- white space character and after to the beginning of buffer. Trailing white space is removed by simply zero-terminating the string after the last non-white space character in buffer.

Parameters:

[in,out] buf - the buffer whose leading and trailing white space should be removed.

Definition at line 159 of file dnxPlugin.c.

Referenced by dnxPluginExternal().

Variable Documentation

int gInitialized = 0 [static]

The module initialization flag.

Definition at line 94 of file dnxPlugin.c.

Referenced by dnxPluginExecute(), dnxPluginExternal(), dnxPluginInit(), dnxPluginInternal(), dnxPluginLoad(), dnxPluginLocate(), dnxPluginRegister(), dnxPluginRelease(), and dnxPluginUnload().

iDnxModule* gModules [static]

The loaded module chain.

Definition at line 91 of file dnxPlugin.c.

char* gPluginPath [static]

The configured plugin path.

Definition at line 93 of file dnxPlugin.c.

Referenced by dnxPluginExternal(), dnxPluginInit(), and dnxPluginRelease().

iDnxPlugin* gPlugins [static]

The loaded plugin chain.

Definition at line 92 of file dnxPlugin.c.


Data Structures
struct	iDnxModule
	The DNX module implementation data structure. More...
struct	iDnxPlugin
	The DNX plugin implementation data structure. More...
struct	DnxPlugin
	An abstract data type for a DNX plugin object. More...
struct	DnxModule
	An abstract data type for a DNX module object. More...
Defines
#define	USE_POLL
#define	MPLEXER "poll"
#define	elemcount(x) (sizeof(x)/sizeof(*(x)))
#define	MAX_PLUGIN_PREFIX 1024
	The maximum plugin prefix.
#define	MAX_PLUGIN_PATH 2048
	The maximum plugin path.
#define	DNX_MAX_ARGV 256
	The maximum number of arguments.
#define	MAX_INPUT_BUFFER 1024
	The maximum input buffer.
#define	DNX_MAX_PLUGIN_NAME 255
	The maximum plugin name length.
Functions
static char *	dnxFgets (char data, int size, FILE fp, int timeout)
	Perform a time sensitive fgets.
static void	strip (char *buf)
	Strip leading and trailing whitespace from a specified string.
static int	dnxPluginRegister (char szPlugin, char szErrMsg)
	Register a dnx plugin with entry points.
static int	dnxPluginLoad (DnxModule *module)
	Load a dnx plugin module into memory.
static void	dnxPluginUnload (DnxModule *module)
	Unload a dnx plugin module from memory.
static int	dnxPluginBaseName (char command, char baseName, int maxData)
	Isolate the base name of a plugin command.
static int	dnxPluginLocate (char command, DnxPlugin *plugin)
	Search for a plugin in the plugin chain.
static int	dnxPluginVector (char command, int argc, char **argv, int maxargs)
	Convert a dnx plugin string to a vector array.
static void	dnxPluginInternal (DnxPlugin plugin, char command, int resCode, char resData, int maxData, int timeout, char *myaddr)
	Executes an internal plugin module.
static void	dnxPluginExternal (char command, int resCode, char resData, int maxData, int timeout, char myaddr)
	Execute an external command line; capture stdout and stderr.
void	dnxPluginExecute (char command, int resCode, char resData, int maxData, int timeout, char myaddr)
	Find an appropriate dnx plugin and use it to execute a commmand.
int	dnxPluginInit (char *pluginPath)
	Initialize the dnx client plugin utility library.
void	dnxPluginRelease (void)
	Clean up the dnx plugin utility library.
Variables
static iDnxModule *	gModules
	The loaded module chain.
static iDnxPlugin *	gPlugins
	The loaded plugin chain.
static char *	gPluginPath
	The configured plugin path.
static int	gInitialized = 0
	The module initialization flag.