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Asterisk developer's documentation


res_clialiases.c

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (C) 2008, Digium, Inc.
00005  *
00006  * Joshua Colp <jcolp@digium.com>
00007  *
00008  * See http://www.asterisk.org for more information about
00009  * the Asterisk project. Please do not directly contact
00010  * any of the maintainers of this project for assistance;
00011  * the project provides a web site, mailing lists and IRC
00012  * channels for your use.
00013  *
00014  * This program is free software, distributed under the terms of
00015  * the GNU General Public License Version 2. See the LICENSE file
00016  * at the top of the source tree.
00017  */
00018 
00019 /*! \file
00020  *
00021  * \brief CLI Aliases
00022  *
00023  * \author\verbatim Joshua Colp <jcolp@digium.com> \endverbatim
00024  * 
00025  * This module provides the capability to create aliases to other
00026  * CLI commands.
00027  */
00028 
00029 
00030 #include "asterisk.h"
00031 
00032 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 252850 $")
00033 
00034 #include "asterisk/module.h"
00035 #include "asterisk/config.h"
00036 #include "asterisk/cli.h"
00037 #include "asterisk/astobj2.h"
00038 
00039 /*! Maximum number of buckets for CLI aliases */
00040 #define MAX_ALIAS_BUCKETS 53
00041 
00042 /*! Configuration file used for this application */
00043 static const char config_file[] = "cli_aliases.conf";
00044 
00045 struct cli_alias {
00046    struct ast_cli_entry cli_entry; /*!< Actual CLI structure used for this alias */
00047    char *alias;                    /*!< CLI Alias */
00048    char *real_cmd;                 /*!< Actual CLI command it is aliased to */
00049 };
00050 
00051 static struct ao2_container *cli_aliases;
00052 
00053 /*! \brief Hashing function used for aliases */
00054 static int alias_hash_cb(const void *obj, const int flags)
00055 {
00056    const struct cli_alias *alias = obj;
00057    return ast_str_hash(alias->cli_entry.command);
00058 }
00059 
00060 /*! \brief Comparison function used for aliases */
00061 static int alias_cmp_cb(void *obj, void *arg, int flags)
00062 {
00063    const struct cli_alias *alias0 = obj, *alias1 = arg;
00064 
00065    return (alias0->cli_entry.command == alias1->cli_entry.command ? CMP_MATCH | CMP_STOP : 0);
00066 }
00067 
00068 /*! \brief Destruction function used for aliases */
00069 static void alias_destroy(void *obj)
00070 {
00071    struct cli_alias *alias = obj;
00072 
00073    /* Unregister the CLI entry from the core */
00074    ast_cli_unregister(&alias->cli_entry);
00075 
00076    return;
00077 }
00078 
00079 /*! \brief Function which passes through an aliased CLI command to the real one */
00080 static char *cli_alias_passthrough(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
00081 {
00082    struct cli_alias *alias;
00083    struct cli_alias tmp = {
00084       .cli_entry.command = e->command,
00085    };
00086    char *generator;
00087    const char *line;
00088 
00089    /* Try to find the alias based on the CLI entry */
00090    if (!(alias = ao2_find(cli_aliases, &tmp, OBJ_POINTER))) {
00091       return 0;
00092    }
00093 
00094    switch (cmd) {
00095    case CLI_INIT:
00096       ao2_ref(alias, -1);
00097       return NULL;
00098    case CLI_GENERATE:
00099       line = a->line;
00100       line += (strlen(alias->alias));
00101       if (!strncasecmp(alias->alias, alias->real_cmd, strlen(alias->alias))) {
00102          generator = NULL;
00103       } else if (!ast_strlen_zero(a->word)) {
00104          struct ast_str *real_cmd = ast_str_alloca(strlen(alias->real_cmd) + strlen(line) + 1);
00105          ast_str_append(&real_cmd, 0, "%s%s", alias->real_cmd, line);
00106          generator = ast_cli_generator(ast_str_buffer(real_cmd), a->word, a->n);
00107       } else {
00108          generator = ast_cli_generator(alias->real_cmd, a->word, a->n);
00109       }
00110       ao2_ref(alias, -1);
00111       return generator;
00112    }
00113 
00114    /* If they gave us extra arguments we need to construct a string to pass in */
00115    if (a->argc != e->args) {
00116       struct ast_str *real_cmd = ast_str_alloca(2048);
00117       int i;
00118 
00119       ast_str_append(&real_cmd, 0, "%s", alias->real_cmd);
00120 
00121       /* Add the additional arguments that have been passed in */
00122       for (i = e->args + 1; i <= a->argc; i++) {
00123          ast_str_append(&real_cmd, 0, " %s", a->argv[i - 1]);
00124       }
00125 
00126       ast_cli_command(a->fd, ast_str_buffer(real_cmd));
00127    } else {
00128       ast_cli_command(a->fd, alias->real_cmd);
00129    }
00130 
00131    ao2_ref(alias, -1);
00132 
00133    return CLI_SUCCESS;
00134 }
00135 
00136 /*! \brief CLI Command to display CLI Aliases */
00137 static char *alias_show(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
00138 {
00139 #define FORMAT "%-50.50s %-50.50s\n"
00140    struct cli_alias *alias;
00141    struct ao2_iterator i;
00142 
00143    switch (cmd) {
00144    case CLI_INIT:
00145       e->command = "cli show aliases";
00146       e->usage =
00147          "Usage: cli show aliases\n"
00148          "       Displays a list of aliased CLI commands.\n";
00149       return NULL;
00150    case CLI_GENERATE:
00151       return NULL;
00152    }
00153 
00154    ast_cli(a->fd, FORMAT, "Alias Command", "Real Command");
00155 
00156    i = ao2_iterator_init(cli_aliases, 0);
00157    for (; (alias = ao2_iterator_next(&i)); ao2_ref(alias, -1)) {
00158       ast_cli(a->fd, FORMAT, alias->alias, alias->real_cmd);
00159    }
00160    ao2_iterator_destroy(&i);
00161 
00162    return CLI_SUCCESS;
00163 #undef FORMAT
00164 }
00165 
00166 /*! \brief CLI commands to interact with things */
00167 static struct ast_cli_entry cli_alias[] = {
00168    AST_CLI_DEFINE(alias_show, "Show CLI command aliases"),
00169 };
00170 
00171 /*! \brief Function called to to see if an alias is marked for destruction, they always are! */
00172 static int alias_marked(void *obj, void *arg, int flags)
00173 {
00174    return CMP_MATCH;
00175 }
00176 
00177 /*! \brief Function called to load or reload the configuration file */
00178 static void load_config(int reload)
00179 {
00180    struct ast_config *cfg = NULL;
00181    struct ast_flags config_flags = { reload ? CONFIG_FLAG_FILEUNCHANGED : 0 };
00182    struct cli_alias *alias;
00183    struct ast_variable *v, *v1;
00184 
00185    if (!(cfg = ast_config_load(config_file, config_flags)) || cfg == CONFIG_STATUS_FILEINVALID) {
00186       ast_log(LOG_ERROR, "res_clialiases configuration file '%s' not found\n", config_file);
00187       return;
00188    } else if (cfg == CONFIG_STATUS_FILEUNCHANGED) {
00189       return;
00190    }
00191 
00192    /* Destroy any existing CLI aliases */
00193    if (reload) {
00194       ao2_callback(cli_aliases, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE , alias_marked, NULL);
00195    }
00196 
00197    for (v = ast_variable_browse(cfg, "general"); v; v = v->next) {
00198       if (strcmp(v->name, "template")) {
00199          ast_log(LOG_WARNING, "%s is not a correct option in [%s]\n", v->name, "general");
00200          continue;
00201       }
00202       /* Read in those there CLI aliases */
00203       for (v1 = ast_variable_browse(cfg, v->value); v1; v1 = v1->next) {
00204          if (!(alias = ao2_alloc((sizeof(*alias) + strlen(v1->name) + strlen(v1->value) + 2), alias_destroy))) {
00205             continue;
00206          }
00207          alias->alias = ((char *) alias) + sizeof(*alias);
00208          alias->real_cmd = ((char *) alias->alias) + strlen(v1->name) + 1;
00209          strcpy(alias->alias, v1->name);
00210          strcpy(alias->real_cmd, v1->value);
00211          alias->cli_entry.handler = cli_alias_passthrough;
00212          alias->cli_entry.command = alias->alias;
00213          alias->cli_entry.usage = "Aliased CLI Command\n";
00214 
00215          ast_cli_register(&alias->cli_entry);
00216          ao2_link(cli_aliases, alias);
00217          ast_verbose(VERBOSE_PREFIX_2 "Aliased CLI command '%s' to '%s'\n", v1->name, v1->value);
00218          ao2_ref(alias, -1);
00219       }
00220    }
00221 
00222    ast_config_destroy(cfg);
00223 
00224    return;
00225 }
00226 
00227 /*! \brief Function called to reload the module */
00228 static int reload_module(void)
00229 {
00230    load_config(1);
00231    return 0;
00232 }
00233 
00234 /*! \brief Function called to unload the module */
00235 static int unload_module(void)
00236 {
00237    ao2_ref(cli_aliases, -1);
00238 
00239    ast_cli_unregister_multiple(cli_alias, ARRAY_LEN(cli_alias));
00240 
00241    return 0;
00242 }
00243 
00244 /*! \brief Function called to load the module */
00245 static int load_module(void)
00246 {
00247    if (!(cli_aliases = ao2_container_alloc(MAX_ALIAS_BUCKETS, alias_hash_cb, alias_cmp_cb))) {
00248       return AST_MODULE_LOAD_DECLINE;
00249    }
00250 
00251    load_config(0);
00252 
00253    ast_cli_register_multiple(cli_alias, ARRAY_LEN(cli_alias));
00254 
00255    return AST_MODULE_LOAD_SUCCESS;
00256 }
00257 
00258 AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT, "CLI Aliases",
00259       .load = load_module,
00260       .unload = unload_module,
00261       .reload = reload_module,
00262       );