 730072e2ef
			
		
	
	730072e2ef
	
	
	
		
			
			Added format checks to functions that expect printf style arguments and fixed any broken calls to these functions.
		
			
				
	
	
		
			313 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			313 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #pragma once
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| /*
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|  * Copyright (c) 2016 MariaDB Corporation Ab
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|  *
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|  * Use of this software is governed by the Business Source License included
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|  * in the LICENSE.TXT file and at www.mariadb.com/bsl11.
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|  *
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|  * Change Date: 2020-01-01
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|  *
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|  * On the date above, in accordance with the Business Source License, use
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|  * of this software will be governed by version 2 or later of the General
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|  * Public License.
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|  */
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| 
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| /**
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|  * @file module_command.h Module driven commands
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|  *
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|  * This header describes the structures and functions used to register new
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|  * functions for modules. It allows modules to introduce custom commands that
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|  * are registered into a module specific domain. These commands can then be
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|  * accessed from multiple different client interfaces without implementing the
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|  * same functionality again.
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|  */
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| 
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| #include <maxscale/cdefs.h>
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| #include <maxscale/dcb.h>
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| #include <maxscale/filter.h>
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| #include <maxscale/monitor.h>
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| #include <maxscale/server.h>
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| #include <maxscale/service.h>
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| #include <maxscale/session.h>
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| #include <maxscale/jansson.h>
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| 
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| MXS_BEGIN_DECLS
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| 
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| /**
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|  * The argument type
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|  *
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|  * First 8 bits of @c value are reserved for argument type, bits 9 through
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|  * 32 are reserved for argument options and bits 33 through 64 are reserved
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|  * for future use.
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|  *
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|  * @c description should be a human-readable description of the argument.
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|  */
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| typedef struct
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| {
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|     uint64_t    type;        /**< The argument type and options */
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|     const char *description; /**< The argument description */
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| } modulecmd_arg_type_t;
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| 
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| /**
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|  * Argument types for the registered functions, the first 8 bits of
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|  * the modulecmd_arg_type_t type's @c value member. An argument can be of
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|  * only one type.
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|  */
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| #define MODULECMD_ARG_NONE        0 /**< Empty argument */
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| #define MODULECMD_ARG_STRING      1 /**< String */
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| #define MODULECMD_ARG_BOOLEAN     2 /**< Boolean value */
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| #define MODULECMD_ARG_SERVICE     3 /**< Service */
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| #define MODULECMD_ARG_SERVER      4 /**< Server */
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| #define MODULECMD_ARG_SESSION     6 /**< Session */
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| #define MODULECMD_ARG_DCB         8 /**< DCB */
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| #define MODULECMD_ARG_MONITOR     9 /**< Monitor */
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| #define MODULECMD_ARG_FILTER      10 /**< Filter */
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| #define MODULECMD_ARG_OUTPUT      11 /**< DCB suitable for writing results to.
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|                                           This should always be the first argument
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|                                           if the function requires an output DCB. */
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| 
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| /** What type of an action does the command perform? */
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| enum modulecmd_type
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| {
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|     MODULECMD_TYPE_PASSIVE, /**< Command only displays data */
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|     MODULECMD_TYPE_ACTIVE   /**< Command can modify data */
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| };
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| 
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| /**
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|  * Options for arguments, bits 9 through 32
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|  */
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| #define MODULECMD_ARG_OPTIONAL            (1 << 8) /**< The argument is optional */
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| #define MODULECMD_ARG_NAME_MATCHES_DOMAIN (1 << 9) /**< Argument module name must match domain name */
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| 
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| /**
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|  * Helper macros
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|  */
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| #define MODULECMD_GET_TYPE(t) ((t)->type & 0xff)
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| #define MODULECMD_ARG_IS_REQUIRED(t) (((t)->type & MODULECMD_ARG_OPTIONAL) == 0)
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| #define MODULECMD_ALLOW_NAME_MISMATCH(t) (((t)->type & MODULECMD_ARG_NAME_MATCHES_DOMAIN) == 0)
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| #define MODULECMD_ARG_PRESENT(t) (MODULECMD_GET_TYPE(t) != MODULECMD_ARG_NONE)
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| 
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| /** Argument list node */
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| struct arg_node
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| {
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|     modulecmd_arg_type_t  type;
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|     union
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|     {
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|         char           *string;
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|         bool           boolean;
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|         SERVICE        *service;
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|         SERVER         *server;
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|         MXS_SESSION    *session;
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|         DCB            *dcb;
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|         MXS_MONITOR    *monitor;
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|         MXS_FILTER_DEF *filter;
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|     } value;
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| };
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| 
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| /** Argument list */
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| typedef struct
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| {
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|     int              argc;
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|     struct arg_node *argv;
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| } MODULECMD_ARG;
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| 
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| /**
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|  * The function signature for the module commands.
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|  *
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|  * The number of arguments will always be the maximum number of arguments the
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|  * module requested. If an argument had the MODULECMD_ARG_OPTIONAL flag, and
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|  * the argument was not provided, the type of the argument will be
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|  * MODULECMD_ARG_NONE.
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|  *
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|  * If the module command produces output, it should be stored in the @c output
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|  * parameter as a json_t pointer. The output should conform as closely as possible
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|  * to the JSON API specification. The minimal requirement for a JSON API conforming
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|  * object is that it has a `meta` field. Ideally, the `meta` field should not
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|  * be used as it offloads the work to the client.
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|  *
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|  * @see http://jsonapi.org/format/
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|  *
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|  * @param argv   Argument list
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|  * @param output JSON formatted output from the command
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|  *
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|  * @return True on success, false on error
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|  */
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| typedef bool (*MODULECMDFN)(const MODULECMD_ARG *argv, json_t** output);
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| 
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| /**
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|  * A registered command
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|  */
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| typedef struct modulecmd
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| {
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|     char                 *identifier; /**< Unique identifier */
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|     char                 *domain; /**< Command domain */
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|     char                 *description; /**< Command description */
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|     enum modulecmd_type   type; /**< Command type, either active or passive */
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|     MODULECMDFN           func; /**< The registered function */
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|     int                   arg_count_min; /**< Minimum number of arguments */
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|     int                   arg_count_max; /**< Maximum number of arguments */
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|     modulecmd_arg_type_t *arg_types; /**< Argument types */
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|     struct modulecmd     *next; /**< Next command */
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| } MODULECMD;
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| 
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| /** Check if the module command can modify the data/state of the module */
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| #define MODULECMD_MODIFIES_DATA(t) (t->type == MODULECMD_TYPE_ACTIVE)
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| 
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| /**
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|  * @brief Register a new command
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|  *
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|  * This function registers a new command into the domain.
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|  *
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|  * @param domain      Command domain
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|  * @param identifier  The unique identifier for this command
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|  * @param entry_point The actual entry point function
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|  * @param argc        Maximum number of arguments
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|  * @param argv        Array of argument types of size @c argc
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|  * @param description Human-readable description of this command
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|  *
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|  * @return True if the module was successfully registered, false on error
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|  */
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| bool modulecmd_register_command(const char *domain, const char *identifier,
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|                                 enum modulecmd_type type, MODULECMDFN entry_point,
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|                                 int argc, modulecmd_arg_type_t *argv,
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|                                 const char *description);
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| 
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| /**
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|  * @brief Find a registered command
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|  *
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|  * @param domain Command domain
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|  * @param identifier Command identifier
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|  * @return Registered command or NULL if no command was found
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|  */
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| const MODULECMD* modulecmd_find_command(const char *domain, const char *identifier);
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| 
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| /**
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|  * @brief Parse arguments for a command
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|  *
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|  * The argument types expect different forms of input.
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|  *
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|  * | Argument type         | Expected input    |
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|  * |-----------------------|-------------------|
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|  * | MODULECMD_ARG_SERVICE | Service name      |
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|  * | MODULECMD_ARG_SERVER  | Server name       |
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|  * | MODULECMD_ARG_SESSION | Session unique ID |
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|  * | MODULECMD_ARG_MONITOR | Monitor name      |
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|  * | MODULECMD_ARG_FILTER  | Filter name       |
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|  * | MODULECMD_ARG_STRING  | String            |
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|  * | MODULECMD_ARG_BOOLEAN | Boolean value     |
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|  * | MODULECMD_ARG_DCB     | Raw DCB pointer   |
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|  * | MODULECMD_ARG_OUTPUT  | DCB for output    |
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|  *
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|  * @param cmd Command for which the parameters are parsed
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|  * @param argc Number of arguments
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|  * @param argv Argument list in string format of size @c argc
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|  * @return Parsed arguments or NULL on error
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|  */
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| MODULECMD_ARG* modulecmd_arg_parse(const MODULECMD *cmd, int argc, const void **argv);
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| 
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| /**
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|  * @brief Free parsed arguments returned by modulecmd_arg_parse
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|  * @param arg Arguments to free
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|  */
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| void modulecmd_arg_free(MODULECMD_ARG *arg);
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| 
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| /**
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|  * @brief Check if an optional argument was defined
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|  *
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|  * This function looks the argument list @c arg at an offset of @c idx and
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|  * checks if the argument list contains a value for an optional argument.
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|  *
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|  * @param arg Argument list
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|  * @param idx Index of the argument, starts at 0
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|  * @return True if the optional argument is present
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|  */
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| bool modulecmd_arg_is_present(const MODULECMD_ARG *arg, int idx);
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| 
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| /**
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|  * @brief Check if module command requires an output DCB
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|  *
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|  * @param cmd Command to check
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|  *
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|  * @return True if module requires a DCB for printing output
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|  */
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| bool modulecmd_requires_output_dcb(const MODULECMD* cmd);
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| 
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| /**
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|  * @brief Call a registered command
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|  *
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|  * This calls a registered command in a specific domain. There are no guarantees
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|  * on the length of the call or whether it will block. All of this depends on the
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|  * module and what the command does.
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|  *
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|  * @param cmd    Command to call
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|  * @param args   Parsed command arguments, pass NULL for no arguments
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|  * @param output JSON output of the called command, pass NULL to ignore output
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|  *
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|  * @return True on success, false on error
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|  */
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| bool modulecmd_call_command(const MODULECMD *cmd, const MODULECMD_ARG *args, json_t** output);
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| 
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| /**
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|  * @brief Set the current error message
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|  *
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|  * Modules that register commands should use this function to report errors.
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|  * This will overwrite any existing error message.
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|  *
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|  * @param format Format string
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|  * @param ... Format string arguments
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|  */
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| void modulecmd_set_error(const char *format, ...) mxs_attribute((format (printf, 1, 2)));
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| 
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| /**
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|  * @brief Get the latest error generated by the modulecmd system
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|  *
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|  * @return Human-readable error message
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|  */
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| const char* modulecmd_get_error();
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| 
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| /**
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|  * @brief Get JSON formatted error
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|  *
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|  * @return The error or NULL if no errors have occurred
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|  */
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| json_t* modulecmd_get_json_error();
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| 
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| /**
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|  * @brief Call a function for each command
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|  *
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|  * Calls a function for each matching command in the matched domains. The filters
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|  * for the domain and identifier are PCRE2 expressions that are matched against
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|  * the domain and identifier. These are optional and both @c domain and @c ident
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|  * can be NULL.
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|  *
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|  * @param domain_re Command domain filter, NULL for all domains
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|  *
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|  * @param ident_re Command identifier filter, NULL for all commands
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|  *
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|  * @param fn Function that is called for every command. The first parameter is
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|  *           the current command. The second parameter is the value of @c data.
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|  *           The function should return true to continue iteration or false to
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|  *           stop iteration early. The function must not call any of the functions
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|  *           declared in modulecmd.h.
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|  *
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|  * @param data User defined data passed as the second parameter to @c fn
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|  *
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|  * @return True on success, false on PCRE2 error. Use modulecmd_get_error()
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|  * to retrieve the error.
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|  */
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| bool modulecmd_foreach(const char *domain_re, const char *ident_re,
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|                        bool(*fn)(const MODULECMD *cmd, void *data), void *data);
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| 
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| /**
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|  * @brief Return argument type as string
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|  *
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|  * This returns the string type of @c type. The returned string must be freed
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|  * by the called.
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|  *
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|  * @param type Type to convert
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|  * @return New string or NULL on memory allocation error
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|  */
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| const char* modulecmd_argtype_to_str(modulecmd_arg_type_t *type);
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| 
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| MXS_END_DECLS
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